bluuebunny/crossref_metadata_2025 huggingface dataset:
The relevance of sexual biographies in individuals convicted of child sexual abuse offenses for the development of pedosexual interests and sexual recidivism
Authors: Breiling Lisanne , Rettenberger Martin , Turner Daniel
Published: July 2020

In the literature concerning the etiology of pedosexual interests, the potential role of early sexual experiences in childhood and adolescence has been discussed. Several studies demonstrated a link between own sexually abusive experiences in childhood and sexual offending later in life which tends to be even stronger for pedosexual offenders. Furthermore, some findings indicate associations between other developmental factors and deviant sexual interests in adulthood. For the present study, sexual biographical data of N = 223 imprisoned men convicted of sexual offenses against children from Austria was analyzed to retrospectively examine whether own sexually abusive experiences and non-abusive forms of early sexual experiences and behaviors are linked to subsequent pedosexual interests and to sexual recidivism. Previous findings concerning the link between own sexually abusive experiences during childhood and subsequent pedosexual interests could partly be replicated. Furthermore, early masturbation behavior characteristics as well as non-abusive prepubescent sexual experiences were linked to indicators of pedosexual interests and also to sexual recidivism. Exclusively pedophilic men showed the strongest accumulation of early sexual experiences and behaviors. Implications of the findings for theory and risk assessment are discussed.
Les suites non numériques et le potentiel de la pensée algébrique chez les élèves du préscolaire
Authors: Boily Manon , Polotskaia Elena , Lessard Geneviève , Anwandter Cuellar Nathalie Silvia
Published: July 2020

Nous présentons dans cet article les analyses d’entretiens menés dans le cadre d’un projet pilote sur les suites non numériques (répétitives et croissantes) auprès de 18 élèves de 4 à 6 ans fréquentant le jardin ou la maternelle dans deux écoles de l’Ontario. Nous avons étudié les composantes d’une pensée algébrique en déterminant les niveaux de performance associée à la tâche à résoudre chez les élèves ainsi que les erreurs et les connaissances numériques interférant dans le processus d’analyse de telles suites. Cette étude nous a permis de caractériser le potentiel d’élèves du préscolaire dans la réalisation d’une tâche portant sur les suites non numériques et, conséquemment, d’identifier des éléments pouvant contribuer ou entraver le développement d’une pensée algébrique.
Cadre d’analyse des raisonnements dans la résolution de problèmes algébriques de type partage inéquitable
Authors: Squalli Hassane , Larguier Mirène , Bronner Alain , Adihou Adolphe
Published: July 2020

L’objet de ce texte est de proposer un cadre d’analyse des raisonnements d’élèves dans la résolution de problèmes de partage inéquitable pouvant être utilisés au primaire et au début du secondaire. Ce cadre repose sur la considération des deux dimensions suivantes : 1) le degré d’analycité du raisonnement et 2) la nature du registre de représentation sémiotique (Duval, 1995) des inconnues et des équations. Les fondements épistémologiques de ce cadre d’analyse s’appuient sur une brève analyse de certaines étapes du développement historique de l’algèbre. Ensuite, les différentes catégories de raisonnement sont illustrées au moyen d’exemples prototypiques issus de productions d’élèves.
Kaléidoscope sur l’accroissement des problèmes de mise en égalité dans les manuels scolaires québécois
Authors: Tremblay Mélanie , Saboya Mireille
Published: July 2020

Dans les manuels de mathématique québécois du premier cycle du secondaire, favoriser l’expression d’un raisonnement analytique conjugué au désir de convaincre l’élève de recourir au langage littéral semblent être les motifs justifiant l’augmentation de problèmes dont la modélisation peut se traduire par une équation où l’on retrouve l’inconnue dans les deux membres de l’égalité. Cet article expose les résultats d’une étude comparative de ces problèmes que nous avons nommés « mise en égalité » qui ont été recensés dans des manuels issus des réformes de 1992 et 2003. À partir du travail de Marchand et Bednarz (1999), les classes de problèmes, les cadres en jeu ainsi que la représentation et le degré d’explicitation de la mise en égalité seront discutés.
Un modèle épistémologique de référence pour la recherche sur l’algèbre élémentaire
Authors: Ruiz-Munzón Noemí , Bosch Marianna , Gascón Josep
Published: July 2020

La théorie anthropologique du didactique attribue un rôle déterminant au questionnement du savoir mathématique et propose comme outil d’analyse l’élaboration de modèles épistémologiques de référence (MER). Nous présentons un MER du développement de l’algèbre scolaire qui s’inscrit dans un modèle plus large permettant d’articuler l’arithmétique, l’algèbre, les nombres relatifs, la modélisation fonctionnelle et le calcul différentiel. Ce modèle prend comme point de départ les « programmes de calcul » et considère l’algèbre comme un processus de modélisation structuré en trois étapes. Nous illustrons sa potentialité pour la création et l’analyse de séquences didactiques dans la première étape du processus d’algébrisation.
Quelles sont les perceptions des élèves présentant des difficultés comportementales quant aux conditions qui influencent leur scolarisation en classe ordinaire?
Authors: Beaudoin Manon , Nadeau Marie-France
Published: July 2020

L’éducation inclusive, qui préconise la scolarisation dans un cadre le plus normal possible, s’impose comme la voie privilégiée pour favoriser la réussite éducative de tous les élèves. Malgré les conditions suggérées pour soutenir celle-ci, l’expérience scolaire des élèves présentant des difficultés comportementales reste difficile. Est-il possible que ces conditions ne tiennent pas compte du point de vue des élèves? La méthode de recension des écrits (n = 42 études: 31 qualitatives, 2 quantitatives, 7 mixtes, 2 recensions) a permis de répondre à l’objectif d’identifier les conditions qui soutiennent ou freinent la scolarisation en classe ordinaire selon les élèves présentant des difficultés comportementales. Dans les deux cas, la relation avec l’enseignant s’avère la condition la plus souvent mentionnée. Les résultats sont discutés à la lumière des caractéristiques méthodologiques des ouvrages pour orienter les futures études.
Russia’s Assistance to Nigerian Economic and Educational Development(1999 – 2019)
Authors: Adebayo Kafilat Motunrayo
Published: July 2020

Abolishing poverty and ensuring improvement of educational development indicators have been described as some of the objectives for international assistance. This study seeks to comprehend the role of Russia in the development of the African continent’s most populous country, Nigeria, the factors that limited their success and the opportunities for increasing effectiveness of such efforts. Russia intervention in Nigeria economic and educational development took a new turn after Nigeria returned to democratic rule in 1999. The existence of the largest Russian investor (RUSAL) in the Nigeria, the investments of LUKOIL in Nigeria which currently exceeds $450 million, and other well-known Russian companies, including the largest Russian producer of agricultural machinery "Rostselmash", have all made impact in Nigeria economic development. However, the major problem of this duo cooperation lies in the legal ratification of their framework. In Educational sphere, this study ascertains that yearly, more than 100 Nigerian students are given the opportunity to study at Russian universities through Russia-Nigerian intergovernmental agreements. To date, more than 10,000 Nigerian specialists have been trained in Russia. The study drew upon both modernization and dependency theories in advancing understanding on the subject matter. The study employed qualitative method of data collection. Data was analyzed using content analysis.
Controlling protein function by fine-tuning conformational flexibility
Authors: Schmid Sonja , Hugel Thorsten
Published: July 2020

In a living cell, protein function is regulated in several ways, including post-translational modifications (PTMs), protein-protein interaction, or by the global environment (e.g. crowding or phase separation). While site-specific PTMs act very locally on the protein, specific protein interactions typically affect larger (sub-)domains, and global changes affect the whole protein non-specifically. Herein, we directly observe protein regulation under three different degrees of localization, and present the effects on the Hsp90 chaperone system at the levels of conformational steady states, kinetics and protein function. Interestingly using single-molecule FRET, we find that similar functional and conformational steady states are caused by completely different underlying kinetics. We disentangle specific and non-specific effects that control Hsp90’s ATPase function, which has remained a puzzle up to now. Lastly, we introduce a new mechanistic concept: functional stimulation through conformational confinement. Our results demonstrate how cellular protein regulation works by fine-tuning the conformational state space of proteins.
Inhibition of post-termination ribosome recycling at premature termination codons in UPF1 ATPase mutants
Authors: Serdar Lucas D , Whiteside DaJuan L , Nock Sarah L , McGrath David , Baker Kristian E
Published: July 2020

Recognition and rapid degradation of mRNA harboring premature translation termination codons (PTCs) serves to protect cells from accumulating non-functional and potentially toxic truncated polypeptides. Targeting of PTC-containing transcripts is mediated by the nonsense-mediated mRNA decay (NMD) pathway and requires a conserved set of proteins including UPF1, an RNA helicase whose ATPase activity is essential for NMD. Previously, we identified a functional interaction between the NMD machinery and terminating ribosomes based on 3’ RNA decay fragments that accrue in UPF1 ATPase mutants. Herein, we show that those decay intermediates originate downstream of the PTC and harbor 80S ribosomes that migrate into the mRNA 3’ UTR independent of canonical translation. Accumulation of 3’ RNA decay fragments is determined by both RNA sequence downstream of the PTC and the inactivating mutation within the active site of UPF1. Our data reveal a failure in post-termination ribosome recycling in UPF1 ATPase mutants.
Genetic and environmental determinants of variation in the plasma lipidome of older Australian twins
Authors: Wong Matthew WK , Thalamuthu Anbupalam , Braidy Nady , Mather Karen A , Liu Yue , Ciobanu Liliana , Baune Bernhardt T , Armstrong Nicola J , Kwok John , Schofield Peter , Wright Margaret J , Ames David , Pickford Russell , Lee Teresa , Poljak Anne , Sachdev Perminder S
Published: July 2020

The critical role of blood lipids in a broad range of health and disease states is well recognised but less explored is the interplay of genetics and environment within the broader blood lipidome. We examined heritability of the plasma lipidome among healthy older-aged twins (75 monozygotic/55 dizygotic pairs) enrolled in the Older Australian Twins Study (OATS) and explored corresponding gene expression and DNA methylation associations. 27/209 lipids (13.3%) detected by liquid chromatography-coupled mass spectrometry (LC-MS) were significantly heritable under the classical ACE twin model (h2 = 0.28–0.59), which included ceramides (Cer) and triglycerides (TG). Relative to non-significantly heritable TGs, heritable TGs had a greater number of associations with gene transcripts, not directly associated with lipid metabolism, but with immune function, signalling and transcriptional regulation. Genome-wide average DNA methylation (GWAM) levels accounted for variability in some non-heritable lipids. We reveal a complex interplay of genetic and environmental influences on the ageing plasma lipidome.
WHONDRS-GUI: a web application for global survey of surface water metabolites
Authors: Lin Xinming , Ren Huiying , Goldman Amy E. , Stegen James C. , Scheibe Timothy D.
Published: July 2020

Background

The Worldwide Hydrobiogeochemistry Observation Network for Dynamic River Systems (WHONDRS) is a consortium that aims to understand complex hydrologic, biogeochemical, and microbial connections within river corridors experiencing perturbations such as dam operations, floods, and droughts. For one ongoing WHONDRS sampling campaign, surface water metabolite and microbiome samples are collected through a global survey to generate knowledge across diverse river corridors. Metabolomics analysis and a suite of geochemical analyses have been performed for collected samples through the Environmental Molecular Sciences Laboratory (EMSL). The obtained knowledge and data package inform mechanistic and data-driven models to enhance predictions of outcomes of hydrologic perturbations and watershed function, one of the most critical components in model-data integration. To support efforts of the multi-domain integration and make the ever-growing data package more accessible for researchers across the world, a Shiny/R Graphical User Interface (GUI) called WHONDRS-GUI was created.

Results

The web application can be run on any modern web browser without any programming or operational system requirements, thus providing an open, well-structured, discoverable dataset for WHONDRS. Together with a context-aware dynamic user interface, the WHONDRS-GUI has functionality for searching, compiling, integrating, visualizing and exporting different data types that can easily be used by the community. The web application and data package are available at https://data.ess-dive.lbl.gov/view/doi:10.15485/1484811, which enables users to simultaneously obtain access to the data and code and to subsequently run the web app locally. The WHONDRS-GUI is also available for online use at Shiny Server (https://xmlin.shinyapps.io/whondrs/).
Salivary proteome of a Neotropical primate: potential roles in host defense and oral food perception
Authors: Espinosa-Gómez Fabiola Carolina , Ruíz-May Eliel , Serio-Silva Juan Carlos , Chapman Colin A.
Published: July 2020

Background

Saliva contains a very complex mixture of proteins for defense against microbiological pathogens and for oral food perception. Howler monkeys are Neotropical primates that can consume a mostly leaf diet. They are well known to thrive in highly disturbed habitats where they may cope with a diversity of dietary challenges and infection risks. We aimed to describe the salivary proteome of howlers to contribute to better understanding of their physiology.

Methods

We analyzed the salivary proteins of wild black howler monkeys (Alouatta pigra), by SDS-PAGE-1-D and Nano LC-MS/MS and categorized them by their function involved in host defense and oral food perception.

Results

Our proteomic analysis identified 156 proteins in howler saliva including a number of host defense peptides that are the first line of defense in mammals, such as defensin, cathelicidin, dermcidin, and lactotransferrin, and proteins with anti-bacterial, anti-fungal, and anti-viral capacity, such as IgA, IgG, IgM, BPI, salivary heat shock 70 kDa protein, beta-2-microbulin, and protein S-100. We also identified key proteins necessary for taste perception, including salivary carbonic anhydrase VI, cystatin D, IgA, and fatty acid-binding protein. Proteins to detect astringent foods were identifying, including four members of cystatins (A, B, C and D), lactoperoxidase, and histidine-rich proteins. No chitinase and amylase were identified as would be expected because howlers do not eat insects and little starch. These findings provide basic information to future studies in oral biology, ingestive physiology, and physiological ecology of mammals and non-human primates.
Description of two new species of the genus Heterochelamon Türkay & Dai, 1997 (Crustacea: Decapoda: Brachyura: Potamidae), from southern China
Authors: Wang Song-Bo , Xu Yi-Yang , Zou Jie-Xin
Published: July 2020

This study describes two new species of freshwater crab of the genus Heterochelamon Türkay & Dai, 1997 from southern China, H. huidongense from Guangdong Province and H. jinxiuense from Guangxi Zhuang Autonomous Region. The two new species can be differentiated from congeners by characters derived from the shape of the epibranchial tooth, external orbital angle, cheliped proportions and structure of the male first gonopod. The present study brings the number of Heterochelamon species to seven. We used the mitochondrial 16S rRNA gene for a molecular analysis and the results are consistent with the morphological features that support the recognition of two new taxa.
An overview of biomass conversion: exploring new opportunities
Authors: Fülöp László , Ecker János
Published: July 2020

Recycling biomass is indispensable these days not only because fossil energy sources are gradually depleted, but also because pollution of the environment, caused by the increasing use of energy, must be reduced. This article intends to overview the results of plant biomass processing methods that are currently in use. Our aim was also to review published methods that are not currently in use. It is intended to explore the possibilities of new methods and enzymes to be used in biomass recycling. The results of this overview are perplexing in almost every area. Advances have been made in the pre-treatment of biomass and in the diversity and applications of the enzymes utilized. Based on molecular modeling, very little progress has been made in the modification of existing enzymes for altered function and adaptation for the environmental conditions during the processing of biomass. There are hardly any publications in which molecular modeling techniques are used to improve enzyme function and to adapt enzymes to various environmental conditions. Our view is that using modern computational, biochemical, and biotechnological methods would enable the purposeful design of enzymes that are more efficient and suitable for biomass processing.
Role of methyltransferase-like enzyme 3 and methyltransferase-like enzyme 14 in urological cancers
Authors: Tao Zijia , Zhao Yiqiao , Chen Xiaonan
Published: July 2020

N6-methyladenosine (m6A) modifications can be found in eukaryotic messenger RNA (mRNA), long non-coding RNA (lncRNA), and microRNA (miRNA). Several studies have demonstrated a close relationship between m6A modifications and cancer cells. Methyltransferase-like enzyme 3 (METTL3) and methyltransferase-like enzyme 14 (METTL14) are two major enzymes involved in m6A modifications that play vital roles in various cancers. However, the roles and regulatory mechanisms of METTL3 and METTL14 in urological cancers are largely unknown. In this review, we summarize the current research results for METTL3 and METTL14 and identify potential pathways involving these enzymes in kidney, bladder, prostate, and testicular cancer. We found that METTL3 and METTL14 have different expression patterns in four types of urological cancers. METTL3 is highly expressed in bladder and prostate cancer and plays an oncogenic role on cancer cells; however, its expression and role are opposite in kidney cancer. METTL14 is expressed at low levels in kidney and bladder cancer, where it has a tumor suppressive role. Low METTL3 or METTL14 expression in cancer cells negatively regulates cell growth-related pathways (e.g., mTOR, EMT, and P2XR6) but positively regulates cell death-related pathways (e.g., P53, PTEN, and Notch1). When METTL3 is highly expressed, it positively regulates the NF-kB and SHH-GL1pathways but negatively regulates PTEN. These results suggest that although METTL3 and METTL14 have different expression levels and regulatory mechanisms in urological cancers, they control cancer cell fate via cell growth- and cell death-related pathways. These findings suggest that m6A modification may be a potential new therapeutic target in urological cancer.
Developing communication and thinking skills in English as a Foreign Language Education undergraduate students: a proposal for a syllabus model
Authors:   Universidad de Zaragoza (España), Delgado-Crespo Violeta , Gil Vicky ,   Universidad de Zaragoza (España), Mur-Dueñas Pilar ,   Universidad de Zaragoza (España), Pellicer-Ortín Silvia ,   Universidad de Zaragoza (España)
Published: July 2020

It is our aim to share a proposal for a new syllabus model and learner-centered methodology for English as a Foreign Language students in the Degree in Teaching in Primary Education at the Universidad de Zaragoza (Spain), presenting the theoretical tenets and analyzing samples of resources and materials that have been designed. In a context of great diversity of levels and learning profiles in the abovementioned educational setting, it is no longer valid to conceive this part of teacher training only in terms of language proficiency, but rather it is necessary to equip students with learning to learn tools and metacognitive strategies as well as materials and resources purposefully designed bearing in mind their context, professional interests and linguistic needs. As a result, throughout the three 6 ECTS courses in the Degree (English in Primary Education I, II and III, for 1st, 2nd and 4th year students respectively) we seek to implement active methodologies and make use of a variety of resources following Communicative Language Teaching and Task-based Instruction principles, such as the following: (i) Deep Learning (Clark, 2009a, 2009b) and Scaffolded, Visible Thinking (Ritchhart, Church, and Morrison, 2011); (ii) Cooperative Learning (Kagan and Kagan, 1994); (iii) ICTs and EdTech; (iv) reflective learning, promoting self-assessment and peer-assessment, and (v) Project Based Learning (BIE, 2003). Overall, the teaching proposal designed has enabled us to partially respond to heterogeneity in our large classes and make our students’ learning of a language relevant and meaningful.
Allocative Efficiency of Maize Production in Chikun Local Government Area of Kaduna State, Nigeria
Authors: Ayodele J. T. , Ijah A. A. , Olukotun O. , Ishola B. F. , Oladele O. N. , Yahaya U. F. , Omodona S.
Published: July 2020

This study analyzed the allocative (cost) efficiency of maize production in Chikun Local Government Area of Kaduna State, Nigeria. Purposive and simple random sampling techniques were used to select 100 respondents. The data collected were analyzed using descriptive statistics and stochastic frontier cost function model. Results revealed that 87% of the respondents were males with 99% of the farmers in their working age group of between 21-60 years. Most (81%) of them were married with 52% of the maize farmers having household size of more than 5 people. Also, 52.0% had post primary school education. The results of the maximum likelihood estimate parameters of the stochastic frontier cost function revealed that cost of maize output, cost of labour, cost of fertilizers, cost of seeds and cost of transportation were significant at 1% level of probability. The allocative efficiency indices revealed that allocative efficiency of the sampled farmers ranged from 1.05 to 3.25 with a mean of 1.31, implying that an average farmer in the study area has costs that are about 31% above the minimum defined by the frontier. This shows that 31% of their costs are wasted compared to the best farmers producing the same maize output using the same technology. The study therefore recommends that adequate farm inputs should be provided at low cost to the farmers and adequate training should be given to the maize farmers in the area of minimizing their expenses on farm inputs in order to avoid cost wastage and become more efficient in allocation of their resources.
Comparative Analysis of the Phytochemicals, Proximate and Mineral Compositions of Scent Leaf (Ocimum gratissimum) and Bitter Leaf (Vernonia amygdalina) Leaves
Authors: Mgbemena Nkoli M. , Amako Ngozi F.
Published: July 2020

Ocimum gratissimum (fam.Lamiaceae) ‘Scent leaf’ and Vernonia amygdalina (fam.Asteraceae) ‘Bitter leaf’ are commonly consumed vegetables in Southern Nigeria. O. gratissimum is used by the ‘Igbos’ of South East Nigeria to flavor soups and stews while it is popular with the ‘Yorubas’ of South West Nigeria for treatment of stomach disorders. V. amygdalina is a well known vegetable in West Africa used as both food and for its pharmaceutical properties. The enormous use of these vegetables in the diet motivated the present study whereby the food compositions, mineral constituents and the phytochemicals of the two vegetables were determined. Qualitative analysis, of the aqueous extracts, revealed the presence of saponins, terpenoids, tannins, flavonoids, steroids, alkaloids, phenolics and anthraquinones in both vegetables. Generally V. amygdalina contained higher quantities of secondary metabolites, saponin which was reported as the highest amount was 5.71±0.12 mg/g and 3.52±0.01 mg/g followed by terpenoids 5.64±0.11 mg/g and 3.40±0.11 mg/g in V. amygdalina and O. gratissimum respectively. There is however a minute amount of anthraquinone in the two vegetables. Proximate analysis and macro elements were determined using their various standard methods. The results of proximate analysis revealed the presence of moisture (12.28 ± 0.02% and 10.01± 0.01%) protein (35.37±0.11% and 22.20±0.02%) and total ash (6.00±0.20% and 5.75±0.10%) each in V. amygdalina and O. gratisimum respectively. The following minerals were present calcium, magnesium, potassium, sodium, iron, copper and zinc, with zinc being in the highest concentration (46.80± 0.03 mg/kg and 58.00±0.12 mg/kg) followed by copper (9.45±0.11 mg/kg and 16.60 ± 0.03 mg/kg) each in V. amygdalina and O. gratissimum respectively. There are higher values of phytochemicals and food components in V. amygdalina while O. gratissimum had higher mineral contents. These two vegetables are potential source of components for complementary medicine.
KDM3A/Ets1 epigenetic axis contributes to PAX3/FOXO1‐driven and independent disease‐promoting gene expression in fusion‐positive Rhabdomyosarcoma
Authors: Sobral Lays M. , Hicks Hannah M. , Parrish Janet K. , McCann Tyler S. , Hsieh Joseph , Goodspeed Andrew , Costello James C. , Black Joshua C. , Jedlicka Paul
Published: July 2020

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children and young adults. RMS exists as two major disease subtypes, oncofusion‐negative RMS (FN‐RMS) and oncofusion‐positive RMS (FP‐RMS). FP‐RMS is characterized by recurrent PAX3/7‐FOXO1 driver oncofusions and is a biologically and clinically aggressive disease. Recent studies have revealed FP‐RMS to have a strong epigenetic basis. Epigenetic mechanisms represent potential new therapeutic vulnerabilities in FP‐RMS, but their complex details remain to be defined. We previously identified a new disease‐promoting epigenetic axis in RMS, involving the chromatin factor KDM3A and the Ets1 transcription factor. In the present study, we define the KDM3A and Ets1 FP‐RMS transcriptomes and show that these interface with the recently characterized PAX3/FOXO1‐driven gene expression program. KDM3A and Ets1 positively control numerous known and candidate novel PAX3/FOXO1‐induced RMS‐promoting genes, including subsets under control of PAX3/FOXO1‐associated superenhancers (SE), such as MEST. Interestingly, KDM3A and Ets1 also positively control a number of known and candidate novel FP‐RMS‐promoting, but not PAX3/FOXO1‐dependent, genes. Epistatically, Ets1 is downstream of, and exerts disease‐promoting effects similar to, both KDM3A and PAX3/FOXO1. MEST also manifests disease‐promoting properties in FP‐RMS, and KDM3A and Ets1 each impacts activation of the PAX3/FOXO1‐associated MEST SE. Taken together, our studies show that the KDM3A/Ets1 epigenetic axis plays an important role in disease promotion in FP‐RMS, and provide insight into potential new ways to target aggressive phenotypes in this disease.
Recent Developments in Cellulose Nanomaterial Composites
Authors: Clarkson Caitlyn M. , El Awad Azrak Sami M. , Forti Endrina S. , Schueneman Gregory T. , Moon Robert J. , Youngblood Jeffrey P.
Published: July 2020

Cellulose nanomaterials (CNMs) are a class of materials that have recently garnered attention in fields as varied as structural materials, biomaterials, rheology modifiers, construction, paper enhancement, and others. As the principal structural reinforcement of biomass giving wood its mechanical properties, CNM is strong and stiff, but also nontoxic, biodegradable, and sustainable with a very large (Gton yr−1) source. Unfortunately, due to the relatively young nature of the field and inherent incompatibility of CNM with most man‐made materials in use today, research has tended to be more basic‐science oriented rather than commercially applicable, so there are few CNM‐enabled products on the market today. Herein, efforts are presented for preparing and forming cellulose nanomaterial nanocomposites. The focus is on recent efforts attempting to mitigate common impediments to practical commercialization but is also placed in context with traditional efforts. The work is presented in terms of the progress made, and still to be made, on solving the most pressing challenges—getting properties that are competitive with currently used materials, removing organic solvent, solving the inherent incompatibility between CNM and polymers of interest, and incorporation into commonly used industrial processing techniques.
Acoustic Vibration‐Induced Actuation of Multiple Microrotors in Microfluidics
Authors: Zhou Yinning , Wang Hao , Ma Zhichao , Yang Joel K. W. , Ai Ye
Published: July 2020

Simultaneous and uniform actuation of multiple microrotors with easy fabrication method has been gathering significant attention in the field of precise microfluidic manipulation. In this work, the use of a piezoelectric vibration stage is presented to achieve the tunable acoustic vibration‐induced actuation of multiple microrotors fabricated by two‐photon polymerization. A series of curved sharp tips are predefined on the microrotors, which can generate paired asymmetric acoustic microstreaming to propel the rotor rotating around the stator with <1 kHz acoustic vibration. Microrotor's rotational speed can be readily controlled by tuning the signal input frequency and the number of rotor arms. A rotational speed of ≈1600 RPM can be achieved by a series of microrotors in aqueous solutions. This method enables easy and versatile microrotor fabrication and remote actuation of multiple rotors with simplicity and uniformity, providing promising solutions in various microfluidic manipulation applications.
Rippled Metallic‐Nanowire/Graphene/Semiconductor Nanostack for a Gate‐Tunable Ultrahigh‐Performance Stretchable Phototransistor
Authors: Haider Golam , Wang Yen‐Hsiang , Sonia Farjana J. , Chiang Chia‐Wei , Frank Otakar , Vejpravova Jana , Kalbáč Martin , Chen Yang‐Fang
Published: July 2020

Despite being one of the most robust materials with intriguing optoelectronic properties, the practical use of single‐layer graphene (SLG) in soft‐electronic technologies is limited due to its poor native stretchability, low absorption coefficient, poor on/off ratio, etc. To circumvent these difficulties, here, a rippled gate‐tunable ultrahigh responsivity nanostack phototransistor composed of SLG, semiconductor‐nanoparticles (NPs), and metallic‐nanowires (NWs) embedded in an elastic film is proposed. The unique electronic conductivity of SLG and high absorption strength of semiconductor‐NPs produce an ultrahigh photocurrent gain. The metallic NWs serve as an excellent stretchable gate electrode. The ripple structured nanomaterials surmount their native stretchability, providing strength and electromechanical stability to the composite. Combining all these unique features, highly stretchable and ultrasensitive phototransistors are created, which can be stretched up to 30% with high repeatability maintaining a photoresponsivity, photocurrent gain, and detectivity of ≈106 A W−1, 107, and 1013 Jones, respectively, which are comparable with the same class of rigid devices. In addition, the device can be turned‐off by applying a suitable gate voltage, which is very convenient for photonic circuits. Moreover, the study can be extended to many other 2D systems, and therefore paves a crucial step for designing high‐performance soft optoelectronic devices for practical applications.
Generalized Chemoselective Transfer Hydrogenation/Hydrodeuteration
Authors: Wang Yong , Cao Xinyi , Zhao Leyao , Pi Chao , Ji Jingfei , Cui Xiuling , Wu Yangjie
Published: July 2020

A generalized, simple and efficient transfer hydrogenation of unsaturated bonds has been developed using HBPin and various proton reagents as hydrogen sources. The substrates, including alkenes, alkynes, aromatic heterocycles, aldehydes, ketones, imines, azo, nitro, epoxy and nitrile compounds, are all applied to this catalytic system. Various groups, which cannot survive under the Pd/C/H2 combination, are tolerated. The activity of the reactants was studied and the trends are as follows: styrene>diphenylmethanimine>benzaldehyde>azobenzene>nitrobenzene>quinoline>acetophenone>benzonitrile. Substrates bearing two or more different unsaturated bonds were also investigated and transfer hydrogenation occurred with excellent chemoselectivity. Nano‐palladium catalyst in situ generated from Pd(OAc)2 and HBPin extremely improved the TH efficiency. Furthermore, chemoselective anti‐Markovnikov hydrodeuteration of terminal aromatic olefins was achieved using D2O and HBPin via in situ HD generation and discrimination.

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Shading decreases rice yield by impeding grain‐filling progress after heading
Authors: Li Qiu‐Ping , Deng Fei , Chen Hong , Zeng Yu‐Ling , Li Bo , Zhong Xiao‐Yuan , Wang Li , Zhou Wei , Chen Yong , Ren Wan‐Jun
Published: July 2020

Shading stress decreases both the yield and quality of rice (Oryza sativa L.), which has become a serious problem in rice production worldwide. However, the effect of shading stress on the grain‐filling progress of rice is not well understood. In this study, field experiments were conducted to investigate the effect of shading on the grain‐filling progress and grain yield of rice at Hanyuan and Wenjiang in Sichuan, China, between 2018 and 2019. The results showed that shading after heading significantly decreased the spikelet‐filling rate and grain weight, as well as the dry weight of grains panicle–1, 30 d after shading; these traits were closely related to the grain yield of rice. Hence, the grain yield decreased by 13.72–22.54% and 6.86–14.35% at Hanyuan and Wenjiang, respectively. However, the influence of shading stress on the spikelet‐filling rate, grain weight, and dry weight of grains panicle–1 30 d after shading differed according to spikelet positions. In general, these influences were greater on spikelets at the bottom and middle positions than on those at the top position. Furthermore, the effects of shading stress on rice differed across study sites; shading stress had a greater effect on grain weight at Hanyuan, but a greater effect on spikelet‐filling rate at Wenjiang. Therefore, it is critical to improve both spikelet‐filling rate and grain weight of spikelets at the bottom and middle positions to maintain the grain yield of rice under shading stress.
Analysis of soybean yield formation differences across different production regions in China
Authors: Xu Cailong , He Yanqin , Sun Shi , Song Wenwen , Wu Tingting , Han Tianfu , Wu Cunxiang
Published: July 2020

Understanding the yield gaps and its limiting factors under different soybean [Glycine max (L.) Merr.] production environments is essential in order to increase yield to meet plant‐based protein and vegetable oil requirements. Soybean yield data from the National Crop Varieties Test (NCVT) were analyzed to identify yield‐limiting factors and yield improvement measures in the four soybean agro‐ecological regions in China. The average yield was 2.70 Mg ha−1, with a unimodal distribution from North to South. The highest yield was in Huang‐Huai‐Hai Plain (HHH), followed by Yangtze River Valley (YRV), Northeast (NE), and Tropical and Subtropical region (TS). Seed weight was a major limiting factor of yield improvement for low‐yield farmfields, while pods per plant and seeds per plant were both limiting factors of yield improvement for middle‐ and high‐yield farmfields. Choosing improved soybean varieties in the right areas is the most critical factor in increasing yields. Selecting high‐yield soybean varieties with high seed weights should be the primary task to further improve the yield for NE region. Increasing seed number and seed weight by preventing pod shedding and abortion with chemical control techniques from flowering to pod formation should be the key yield‐increasing measures for soybean production in YRV and TS regions. Furthermore, attention should be paid to maintaining soil moisture and ensuring water supply in HHH region. Furthermore, advanced agronomic techniques, such as high‐precision sowing, proper plant protection controls, and proper fertilizer formulas based on soil testing, are also vital measures to improve soybean yields.
Engineering Intelligent Nanosystems for Enhanced Medical Imaging
Authors: van Moolenbroek Guido T. , Patiño Tania , Llop Jordi , Sánchez Samuel
Published: July 2020

Medical imaging serves to obtain anatomical and physiological data, supporting medical diagnostics as well as providing therapeutic evaluation and guidance. A variety of contrast agents have been developed to enhance the recorded signals and to provide molecular imaging. However, fast clearance from the body or nonspecific biodistribution often limit their efficiency, constituting challenges that need to be overcome. Nanoparticle‐based systems are currently emerging as versatile and highly integrated platforms providing improved circulating times, tissue specificity, high loading capacity for signaling moieties, and multimodal imaging features. Furthermore, nanoengineered devices can be tuned for specific applications and the development of responsive behaviors. Responses include in situ modulation of nanoparticle size, increased intratissue mobility through active propulsion of motorized particles, and active modulation of the particle surroundings such as the extracellular matrix for an improved penetration and retention at the desired locations. Once accumulated in the targeted tissue, smart nanoparticle‐based contrast agents can provide molecular sensing of biomarkers or characteristics of the tissue microenvironment. In this case, the signal or contrast provided by the nanosystem is responsive to the presence or concentration of an analyte. Herein, recent developments of intelligent nanosystems to improve medical imaging are presented.
Mandibular shape variation in mainland and insular hylobatids
Authors: Pitirri M. Kathleen , Vermeulen Erin , Komza Klara , Begun David R.
Published: July 2020

Although hylobatids are the most speciose of the living apes, their morphological interspecies and intraspecies variation remains poorly understood. Here, we assess mandibular shape variation in two species ofHylobates, white‐handed (Hylobates lar) and black‐handed (Hylobates agilis) gibbons. Using 71 three‐dimensional landmarks to quantify mandibular shape, interspecies and intraspecies variation and geographic patterns of mandibular shape are examined in a mixed sex sample of adultH. larandH. agilisthrough generalized Procrustes analysis, Procrustes analysis of variance, and principal components analysis. We find that relative toH. agilis, H. larexhibits a higher amount of variation in mandibular shape. Both species demonstrate similar allometric patterns in mandibular shape. We also highlight a geographic pattern in mandibular shape variation. Compared to mainland hylobatids, insular hylobatids have relatively lower, more posteriorly oriented, and anteroposteriorly wider mandibular condyles, with an increased distance between the condyles and the coronoid processes. This geographic pattern could reflect differences in functional demands on the mandible during mastication and/or could be driven by factors often associated with evolutionary pressures of island populations relative to mainland populations. The findings of this study highlight how little is known aboutHylobatesmorphological variation and how important this is for usingHylobatesto help interpret the primate fossil record. Understanding interspecific and intraspecific variation in extant primates is vital to interpreting variation in the primate fossil record.
Transition‐Metal‐Containing Porphyrin Metal–Organic Frameworks as π‐Backbonding Adsorbents for NO2 Removal
Authors: Shang Shanshan , Yang Chao , Wang Chenguang , Qin Junsheng , Li Yi , Gu Qinfen , Shang Jin
Published: July 2020

Mitigating ambient nitrogen dioxide (NO2) pollution via selective adsorption on porous materials is a promising approach to tackle such an increasingly pressing environmental health issue. However, very few porous adsorbents have sufficiently high NO2 adsorption capacity and good regenerability simultaneously. Here we attempt to address this challenge by developing π‐backbonding adsorbents in the transition metal (TM) incorporated porphyrin metal–organic frameworks (PMOFs). Breakthrough experiments show that PMOFs with inserted TMs achieve appreciable NO2 capacity and good regenerability. Combined in situ DRIFTS, synchrotron powder XRD, and DFT calculations reveal the adsorption mechanism: NO2 partially transforms to N2O4 and interacts with transition metal via π‐backbonding and Al‐node via hydrogen bonding. This work affords new insights for designing next‐generation adsorbents for ambient NO2 removal and presents PMOFs as a platform to tailor π‐backbonding adsorbents.
Covalent Triazine Framework Nanoparticles via Size‐Controllable Confinement Synthesis for Enhanced Visible‐Light Photoredox Catalysis
Authors: Huang Wei , Huber Niklas , Jiang Shuai , Landfester Katharina , Zhang Kai A. I.
Published: July 2020

For metal‐free, organic conjugated polymer‐based photocatalysts, synthesis of defined nanostructures is still highly challenging. Here, we report the formation of covalent triazine framework (CTF) nanoparticles via a size‐controllable confined polymerization strategy. The uniform CTF nanoparticles exhibited significantly enhanced activity in the photocatalytic formation of dibenzofurans compared to the irregular bulk material. The optoelectronic properties of the nanometer‐sized CTFs could be easily tuned by copolymerizing small amounts of benzothiadiazole into the conjugated molecular network. This optimization of electronic properties led to a further increase in observed photocatalytic efficiency, resulting in total an 18‐fold enhancement compared to the bulk material. Full recyclability of the heterogeneous photocatalysts as well as catalytic activity in dehalogenation, hydroxylation and benzoimidazole formation reactions demonstrated the utility of the designed materials.
Divergent and Stereoselective Synthesis of Tetraarylethylenes from Vinylboronates
Authors: Zhang Minghao , Yao Yisen , Stang Peter J. , Zhao Wanxiang
Published: July 2020

The synthesis of a new tetraborylethylene (TBE) is reported, and its application in the preparation of [4+0]‐tetraarylethenes (TAEs) is elucidated. TAEs have widespread applications in material science and supramolecular chemistry due to their aggregation‐induced emission (AIE) properties. The divergent and stereoselective synthesis of [3+1]‐, [2+2]‐, and [2+1+1]‐TAEs via multiple couplings of vinylboronates with aryl bromides is demonstrated. These couplings feature a broad substrate scope and excellent functional group compatibility due to mild reaction conditions. Facile access to various tetraarylethenes is provided. This strategy represents an important complement to the conventional methods employed for the synthesis of TAEs, and would be a valuable tool for synthesizing TAE‐based molecules useful in functional materials, biological imaging and chemical sensing.
An Enolate‐Structure‐Enabled Anionic Cascade Cyclization Reaction: Easy Access to Complex Scaffolds with Contiguous Six‐, Five‐, and Four‐Membered Rings
Authors: Javorskis Tomas , Karpavičienė Ieva , Jurys Arminas , Snarskis Gustautas , Bukšnaitienė Rita , Orentas Edvinas
Published: July 2020

Catalyst‐free addition of ketone enolate to non‐activated multiple C−C bonds involves non‐complementary reaction partners and typically requires super‐basic conditions. On the other hand, highly aggregated or solvated enolates are not reactive enough to undergo direct addition to alkenes or alkynes. Herein, we report a new anionic cascade reaction for one‐step assembly of intriguing molecular scaffolds possessing contiguous six‐, five‐, and four‐membered rings, representing a formal [2+2] enol–allene cycloaddition. Reaction proceeds under very mild conditions and with excellent diastereoselectivity. Deeper mechanistic and computational studies revealed unusually slow proton transfer phenomenon in cyclic ketone intermediate and explained peculiar stereochemical outcome.
Highly Efficient Deep‐Red Non‐Doped Diodes Based on a T‐Shape Thermally Activated Delayed Fluorescence Emitter
Authors: Zhao Bingjie , Wang Huiqin , Han Chunmiao , Ma Peng , Li Zhe , Chang Peng , Xu Hui
Published: July 2020

Device simplification is of practical significance for organic light emitting diodes (OLEDs), and remains the great challenge for deep‐red emitters. Herein, a deep‐red thermally activated delayed fluorescence molecule (pTPA‐DPPZ) is reported which features a T shaped structure containing two triphenylamine (TPA) donors, one either side of a planar dipyridophenazine (DPPZ) acceptor. The rational spatial arrangement of the functional groups leads to limited but sufficient molecular packing for effective carrier transport. The neat pTPA‐DPPZ film achieves an around 90‐fold improved radiation rate constant of 107 s−1 and the nearly unitary reverse intersystem crossing (RISC) efficiency, as well as accelerated emission decays for quenching suppression. The high radiation and RISC result in a photoluminescence quantum yield of 87 %. The bilayer OLED based on the pTPA‐DPPZ emissive layer achieved the record external quantum efficiencies of 12.3 % for maximum and 10.4 % at 1000 nits, accompanied by the deep‐red electroluminescence with the excellent color purity.
Enantiodivergent [4+2] Cycloaddition of Dienolates by Polyfunctional Lewis Acid/Zwitterion Catalysis
Authors: Miskov‐Pajic Vukoslava , Willig Felix , Wanner Daniel M. , Frey Wolfgang , Peters René
Published: July 2020

Diels–Alder reactions have become established as one of the most effective ways to prepare stereochemically complex six‐membered rings. Different catalysis concepts have been reported, including dienophile activation by Lewis acids or H‐bond donors and diene activation by bases. Herein we report a new concept, in which an acidic prodiene is acidified by a Lewis acid to facilitate deprotonation by an imidazolium–aryloxide entity within a polyfunctional catalyst. A metal dienolate is thus formed, while an imidazolium–ArOH moiety probably forms hydrogen bonds with the dienophile. The catalyst type, readily prepared in few steps in high overall yield, was applied to 3‐hydroxy‐2‐pyrone and 3‐hydroxy‐2‐pyridone as well as cyclopentenone prodienes. Maleimide, maleic anhydride, and nitroolefin dienophiles were employed. Kinetic, spectroscopic, and control experiments support a cooperative mode of action. High enantioselectivity was observed even with unprecedented TONs of up to 3680.