bluuebunny/crossref_metadata_2025 huggingface dataset:
Teacher Burnout
Authors: Mahmoodi‐Shahrebabaki Masoud
Published: June 2019

Professional burnout is a multidimensional syndrome characterized by feelings of interpersonal disengagement, reduced accomplishment, and emotional fatigue. As suggested by numerous studies, burnout is engendered by persistent exposure to job‐related stressors. Burnout has internationally been recognized as a severe occupational predicament, which can cause adverse effects on teacher effectiveness and student achievement. Teachers have an emotionally demanding job and are always susceptible to burnout. Converging evidence suggests that teacher burnout is one of the primary predictors of teacher turnover. Not only does burnout undermine instructional quality, but it also leads to irreversible mental, psychological, and physical harm to the well‐being of teachers. This paper aims to provide an overview of the theoretical concept of burnout followed by a discussion of the related pedagogical and research implications. Furthermore, preventive and coping strategies are discussed in light of the latest research findings.
Evaluation of setup and intrafraction motion for surface guided whole‐breast cancer radiotherapy
Authors: Hattel Sandra Helene , Andersen Peter Andreas , Wahlstedt Isak Hannes , Damkjær Sidsel , Saini Arpit , Thomsen Jakob Borup
Published: June 2019

Surface Guided Radiotherapy (SGRT) is a relatively new technique for positioning patients and for monitoring patient movement during treatment. SGRT is completely non‐invasive since it uses visible light for determining the position of the patient surface. A reduction in daily imaging for patient setup is possible if the accuracy of SGRT is comparable to imaging. It allows for monitoring of intrafraction motion and the radiation beam can be held beyond a certain threshold resulting in a more accurate irradiation. The purpose of this study was to investigate setup uncertainty and the intrafraction motion in non‐gated whole breast cancer radiotherapy treatment using an integrated implementation of AlignRT (OSMS) system as SGRT. In initial setup, SGRT was compared to three‐point setup using tattoos on the patient and orthogonal kV imaging. For the investigation of intrafraction motion, OSMS monitored the patient with six degrees of freedom during treatment. Using three‐point setup resulted in a setup root‐mean‐square error from the isocenter of 5.4 mm. This was improved to 4.2 mm using OSMS. For the translational directions, OSMS showed improvements in the lateral direction (P = 0.0009, Wilcoxon rank‐sum), but for the longitudinal direction and rotation it was not possible to show improvements (P = 0.96 and P = 0.46, respectively). The vertical direction proved more accurate for three‐point setup than OSMS (P = 0.000004). Intrafraction motion was very limited with a translational median of 1.1 mm from the isocenter. While OSMS showed marked improvements over laser and tattoo setup, the system did not prove accurate enough to replace the daily orthogonal kV images aligned to bony anatomy.
Electroclinical features of insulo‐opercular epilepsy: an SEEG and PET study
Authors: Wang Xiu , Hu Wenhan , McGonigal Aileen , Zhang Chao , Sang Lin , Zhao Baotian , Sun Tao , Wang Feng , Zhang Jian‐guo , Shao Xiaoqiu , Zhang Kai
Published: June 2019

Objective

To report clinical experience with presurgical evaluation in patients with insulo‐opercular epilepsy. Quantitative analysis on PET imaging and stereoelectroencephalography (SEEG) signals was used to summarize their electroclinical features.

Methods

Twenty‐two patients with focal epilepsy arising from the insular and/or opercular cortex according to SEEG were retrospectively analyzed. Presurgical noninvasive data were analyzed in detail. Interictal PET data of patients were then statistically compared with those of healthy controls to identify the interictal hypometabolic network. The epileptogenicity index (EI) of ictal SEEG signal was computed to identify areas of spread at the beginning of seizure onset.

Results

Focal tonic seizures of the face and/or neck (16/22, 73%) were the most prevalent early objective signs. Epileptic discharges in the interictal and ictal scalp‐EEG mostly showed an ipsilateral perisylvian distribution. Statistical analysis of interictal PET showed significant hypometabolism in the insular lobe, central operculum, supplementary motor area, middle cingulate cortex, bilateral caudate nuclei, and putamen. According to the EI analysis, insulo‐opercular epilepsy could be classified as insulo‐opercular epilepsy (50%), opercular epilepsy (41%), and insular cortex epilepsy (9%).

Significance

Clinical diagnosis of insulo‐opercular epilepsy is challenging because of its complex seizure semiology and nonlocalizing discharges on scalp‐EEG. A common hypometabolic network involving the insulo‐opercular cortex, mesial frontal cortex and subcortical nuclei may be involved in the organization of the insulo‐opercular epilepsy network. Furthermore, quantified SEEG analysis suggested that pure insular epilepsy is rare, and the close connection between insular and opercular cortex necessitates SEEG implantation to define the epileptogenic zone.
Biomechanical Energy‐Harvesting Wearable Textile‐Based Personal Thermal Management Device Containing Epitaxially Grown Aligned Ag‐Tipped‐NixCo1−xSe Nanowires/Reduced Graphene Oxide
Authors: Hazarika Ankita , Deka Biplab K. , Jeong Changyoon , Park Young‐Bin , Park Hyung Wook
Published: June 2019

Energy consumption is increasing with the rapid growth of externally powered electronics. A vast amount of energy is needed for indoor heating, and body heat is dissipated to the surroundings. Recently, wearable heaters have attracted interest for their efficiency in providing articular thermotherapy. Herein, the fabrication of a personal thermal management device with a self‐powering ability to generate heat through triboelectricity is reported. Composites are prepared with vertically aligned silver tipped nickel cobalt selenide (Ag@NixCo1−xSe) nanowire arrays synthesized on the surface of woven Kevlar fiber (WKF) sheets and reduced graphene oxide (rGO) dispersed in polydimethylsiloxane (PDMS). The Ag@NixCo1−xSe with rGO induces effective Joule heating in the composites (79 °C at 2.1 V). The WKF/Ag@NixCo1−xSe/PDMS composite shows higher infrared reflectivity (98.1%) and thermal insulation (54.8%) than WKF/PDMS. The WKF/Ag@NixCo1−xSe/PDMS/rGO composite has an impact resistance and tensile strength that are 152.2% and 92.1% higher, respectively, than those of WKF/PDMS. A maximum output power density of 1.1 mW cm−2 at a low frequency of 5 Hz confirms efficient mechanical energy harvesting of the composites, which enables self‐heating. The high flexibility, breathability, washability, and effective heat generation achieved during body movement satisfy the wearability requirement and can address global energy concerns.
Osteochondral Regeneration with 3D‐Printed Biodegradable High‐Strength Supramolecular Polymer Reinforced‐Gelatin Hydrogel Scaffolds
Authors: Gao Fei , Xu Ziyang , Liang Qingfei , Li Haofei , Peng Liuqi , Wu Mingming , Zhao Xiaoli , Cui Xu , Ruan Changshun , Liu Wenguang
Published: June 2019

Biomacromolecules with poor mechanical properties cannot satisfy the stringent requirement for load‐bearing as bioscaffolds. Herein, a biodegradable high‐strength supramolecular polymer strengthened hydrogel composed of cleavable poly(N‐acryloyl 2‐glycine) (PACG) and methacrylated gelatin (GelMA) (PACG‐GelMA) is successfully constructed by photo‐initiated polymerization. Introducing hydrogen bond‐strengthened PACG contributes to a significant increase in the mechanical strengths of gelatin hydrogel with a high tensile strength (up to 1.1 MPa), outstanding compressive strength (up to 12.4 MPa), large Young's modulus (up to 320 kPa), and high compression modulus (up to 837 kPa). In turn, the GelMA chemical crosslinking could stabilize the temporary PACG network, showing tunable biodegradability by adjusting ACG/GelMA ratios. Further, a biohybrid gradient scaffold consisting of top layer of PACG‐GelMA hydrogel‐Mn2+ and bottom layer of PACG‐GelMA hydrogel‐bioactive glass is fabricated for repair of osteochondral defects by a 3D printing technique. In vitro biological experiments demonstrate that the biohybrid gradient hydrogel scaffold not only supports cell attachment and spreading but also enhances gene expression of chondrogenic‐related and osteogenic‐related differentiation of human bone marrow stem cells. Around 12 weeks after in vivo implantation, the biohybrid gradient hydrogel scaffold significantly facilitates concurrent regeneration of cartilage and subchondral bone in a rat model.
A Portable and Efficient Solar‐Rechargeable Battery with Ultrafast Photo‐Charge/Discharge Rate
Authors: Hu Yuxiang , Bai Yang , Luo Bin , Wang Songcan , Hu Han , Chen Peng , Lyu Miaoqiang , Shapter Joe , Rowan Alan , Wang Lianzhou
Published: June 2019

The solar‐rechargeable electric energy storage systems (SEESSs), which can simultaneously harvest and store solar energy, are considered a promising next‐generation renewable energy supply system. However, the difficulty in meeting the demands of higher overall photoelectric conversion and storage efficiency (PCSE) with both high power density and large energy density in the current SEESSs severely limit their practical application. Herein, a new class is demonstrated of portable and highly efficient SEESS that uniquely integrates a perovskite solar module (PSM) and an aluminum‐ion battery (AIB) directly on a bifunctional aluminum electrode without any external circuit. Such nanostructural design in the SEESS not only exhibits fast photo‐charge/discharge rate (less than one minute) with high power density (above 5000 W kg−1), but also delivers a high energy density (above 43 Wh kg−1). By rationally matching the maximum power point voltage of PSM with AIB charging voltage, an excellent solar‐charging efficiency of 15.2% and a high PCSE of 12.04% are achieved, which is among the best in all reported portable SEESSs. Moreover, enhanced PCSE is observed as the light intensity decreases, which makes such SEESS immune from the geographical location and climate limitations for diverse practical applications.
Suppression of Recombination Losses in Polymer:Nonfullerene Acceptor Organic Solar Cells due to Aggregation Dependence of Acceptor Electron Affinity
Authors: Cha Hyojung , Fish George , Luke Joel , Alraddadi Ahmad , Lee Hyun Hwi , Zhang Weimin , Dong Yifan , Limbu Saurav , Wadsworth Andrew , Maria Iuliana P. , Francàs Laia , Sou Hou Lon , Du Tian , Kim Ji‐Seon , McLachlan Martyn A. , McCulloch Iain , Durrant James R.
Published: June 2019

Here, it is investigated whether an energetic cascade between mixed and pure regions assists in suppressing recombination losses in non‐fullerene acceptor (NFA)‐based organic solar cells. The impact of polymer‐NFA blend composition upon morphology, energetics, charge carrier recombination kinetics, and photocurrent properties are studied. By changing film composition, morphological structures are varied from consisting of highly intermixed polymer‐NFA phases to consisting of both intermixed and pure phase. Cyclic voltammetry is employed to investigate the impact of blend morphology upon NFA lowest unoccupied molecular orbital (LUMO) level energetics. Transient absorption spectroscopy reveals the importance of an energetic cascade between mixed and pure phases in the electron–hole dynamics in order to well separate spatially localized electron–hole pairs. Raman spectroscopy is used to investigate the origin of energetic shift of NFA LUMO levels. It appears that the increase in NFA electron affinity in pure phases relative to mixed phases is correlated with a transition from a relatively planar backbone structure of NFA in pure, aggregated phases, to a more twisted structure in molecularly mixed phases. The studies focus on addressing whether aggregation‐dependent acceptor LUMO level energetics are a general design requirement for both fullerene and NFAs, and quantifying the magnitude, origin, and impact of such energetic shifts upon device performance.
Fitness of an allopolyploid rupicolous fern compared with its diploid progenitors: from sporogenesis to sporophyte formation
Authors: Pangua Emilia , Pajarón Santiago , Quintanilla Luis G.
Published: June 2019

Premise

When two populations of related cytotypes grow in sympatry, the rarer cytotype tends to be excluded due to a frequency‐dependent mating disadvantage. Evolutionary models predict that polyploids, which are typically the rarer cytotype upon first formation, should have higher relative fitness and/or higher selfing rates to establish and then coexist with diploid parents.

Methods

Performance during early recruitment was compared among three co‐occurring rupicolous fern species: the allotetraploid Cheilanthes tinaei and its diploid ancestors, C. hispanica and C. maderensis. In culture experiments, fresh spores and samples of soil spore banks were tested for variation among cytotypes in germination, survival, fecundity, and mating system of gametophytes.

Results

Compared with its diploid parents, C. tinaei fresh spores had higher abortion percentages, lower dispersal ability as a result of its larger spores, and similar vigor at germination. For gametophytes from soil spore banks, C. tinaei had high survival similar to C. maderensis, but its sex expression resembled that of C. hispanica, with a high proportion of males. Patterns of sporophyte formation by females and bisexuals indicate that the polyploid does not have an increased gametophytic selfing rate. Gametophytes were larger in C. tinaei, but its reproductive success (sporophyte formation) was intermediate relative to diploids.

Conclusions

Our results show no evidence of higher selfing or fitness advantage of the allopolyploid over both diploid parents at any stage of early recruitment. These two unexpected findings suggest that further factors, such as niche differentiation, play a more important role in cytotype coexistence.
Skin picking disorder in 97 Italian and Spanish Cri du chat patients
Authors: Spunton Marianna , Guala Andrea , Liverani Maria E. , Medolago Luisa , Tognon Fabio , Casado Félix , del Valle Marta , Porras Josefina , Larrea Isabel , Porta Giovanni , Albani Giovanni , Nevado Julian , Danesino Cesare
Published: June 2019

Skin picking (SP) disorder is characterized by recurrent SP resulting in skin lesions. Several studies estimated its prevalence as approximately 2–4 % of the general population. It is also present in a high percentage of patients with intellectual and developmental disabilities, such as Cri du chat (CdC) syndrome, a rare genetic disorder caused by variable size deletions of the short arm of chromosome 5. The aim of this study was to evaluate, in 97 patients with CdC syndrome, the following data: frequency of SP, patient's age at onset, type, and topographic–anatomic distribution of the lesions presented. The results show that 85% of patients confirm a SP disorder, usually concentrated on the hands, fingers, and the face, with onset between 6 and 10 years of age, regardless of patient's sex. Evidence for early appearance of SP behavior, high prevalence in stressful circumstances, and efficacy of distracting actions immediately suggest the possibility that proper parental information about SP behavior and parental education concerning the methods to deal with this problem may result in its efficient reduction already in childhood.
A competitive drive? Same‐sex attentional preferences in capuchins
Authors: Lonsdorf Elizabeth V. , Engelbert Lindsey M. , Howard Lauren H.
Published: June 2019

In primates, faces provide information about several characteristics of social significance, including age, physical health, and biological sex. However, despite a growing literature on face processing and visual attention in a number of primate species, preferences for same‐ or opposite‐sex faces have not yet been examined. In the current study, we explore the role of conspecific sex on visual attention in two groups of capuchin monkeys. Subjects were shown a series of image pairs on a Tobii Pro TX300 eye tracker, each depicting an unfamiliar male and an unfamiliar female face. Given the behavioral evidence of mate choice in both sexes, we hypothesized that capuchins would preferentially attend to images of unfamiliar conspecifics of the opposite sex. Our alternative hypothesis was that capuchins would preferentially attend to same‐sex individuals to assess potential competitors. Our results provide support for our alternative hypothesis. When comparing attention to each stimuli type across sexes, females spent significantly larger percentages of time than males looking at female photos, whereas males spent significantly larger percentages of time than females looking at male photos. Within each sex, females looked for significantly larger percentages of time to female versus male images. Males also looked for larger percentages of time to same‐sex images, though not significantly. To our knowledge, these data are the first to demonstrate significant sex‐biased attentional preferences in adult primates of any species, and suggest that, for capuchins, potential competitors garner more attention than potential mates. In addition, our findings have implications for studies of visual attention and face processing across the primate order, and suggest that researchers need to control for these demographic factors in their experimental designs.
PDXK mutations cause polyneuropathy responsive to pyridoxal 5′‐phosphate supplementation
Authors: Chelban Viorica , Wilson Matthew P. , Warman Chardon Jodi , Vandrovcova Jana , Zanetti M. Natalia , Zamba‐Papanicolaou Eleni , Efthymiou Stephanie , Pope Simon , Conte Maria R. , Abis Giancarlo , Liu Yo‐Tsen , Tribollet Eloise , Haridy Nourelhoda A. , Botía Juan A. , Ryten Mina , Nicolaou Paschalis , Minaidou Anna , Christodoulou Kyproula , Kernohan Kristin D. , Eaton Alison , Osmond Matthew , Ito Yoko , Bourque Pierre , Jepson James E. C. , Bello Oscar , Bremner Fion , Cordivari Carla , Reilly Mary M. , Foiani Martha , Heslegrave Amanda , Zetterberg Henrik , Heales Simon J. R. , Wood Nicholas W. , Rothman James E. , Boycott Kym M. , Mills Philippa B. , Clayton Peter T. , Houlden Henry ,   for the Care4Rare Canada Consortium and the SYNaPS Study Group
Published: June 2019

Objective

To identify disease‐causing variants in autosomal recessive axonal polyneuropathy with optic atrophy and provide targeted replacement therapy.

Methods

We performed genome‐wide sequencing, homozygosity mapping, and segregation analysis for novel disease‐causing gene discovery. We used circular dichroism to show secondary structure changes and isothermal titration calorimetry to investigate the impact of variants on adenosine triphosphate (ATP) binding. Pathogenicity was further supported by enzymatic assays and mass spectroscopy on recombinant protein, patient‐derived fibroblasts, plasma, and erythrocytes. Response to supplementation was measured with clinical validated rating scales, electrophysiology, and biochemical quantification.

Results

We identified biallelic mutations in PDXK in 5 individuals from 2 unrelated families with primary axonal polyneuropathy and optic atrophy. The natural history of this disorder suggests that untreated, affected individuals become wheelchair‐bound and blind. We identified conformational rearrangement in the mutant enzyme around the ATP‐binding pocket. Low PDXK ATP binding resulted in decreased erythrocyte PDXK activity and low pyridoxal 5′‐phosphate (PLP) concentrations. We rescued the clinical and biochemical profile with PLP supplementation in 1 family, improvement in power, pain, and fatigue contributing to patients regaining their ability to walk independently during the first year of PLP normalization.

Interpretation

We show that mutations in PDXK cause autosomal recessive axonal peripheral polyneuropathy leading to disease via reduced PDXK enzymatic activity and low PLP. We show that the biochemical profile can be rescued with PLP supplementation associated with clinical improvement. As B6 is a cofactor in diverse essential biological pathways, our findings may have direct implications for neuropathies of unknown etiology characterized by reduced PLP levels. ANN NEUROL 2019;86:225–240
Promoting Subordinate, Efficient Ruthenium Sites with Interstitial Silicon for Pt‐Like Electrocatalytic Activity
Authors: Chen Hui , Ai Xuan , Liu Wang , Xie Zhoubing , Feng Weiqiang , Chen Wei , Zou Xiaoxin
Published: June 2019

The fundamental understanding and rational manipulation of catalytic site preference at extended solid surfaces is crucial in the search for advanced catalysts. Herein we find that the Ru top sites at metallic ruthenium surface have efficient Pt‐like activity for the hydrogen evolution reaction (HER), but they are subordinate to their adjacent, less active Ru3‐hollow sites due to the stronger hydrogen‐binding ability of the latter. We also present an interstitial incorporation strategy for the promotion of the Ru top sites from subordinate to dominant character, while maintaining Pt‐like catalytic activity. Our combined theoretical and experimental studies further identify intermetallic RuSi as a highly active, non‐Pt material for catalyzing the HER, because of its suitable electronic structure governed by a good balance of ligand and strain effects.
High‐Throughput Isolation of Cell Protrusions with Single‐Cell Precision for Profiling Subcellular Gene Expression
Authors: Zhang Pengchao , Han Xin , Yao Jun , Shao Ning , Zhang Kai , Zhou Yufu , Zu Youli , Wang Bin , Qin Lidong
Published: June 2019

Invading cancer cells extend cell protrusions, which guide cancer‐cell migration and invasion, eventually leading to metastasis. The formation and activity of cell protrusions involve the localization of molecules and organelles at the cell front; however, it is challenging to precisely isolate these subcellular structures at the single‐cell level for molecular analysis. Here, we describe a newly developed microfluidic platform capable of high‐throughput isolation of cell protrusions at single‐cell precision for profiling subcellular gene expression. Using this microfluidic platform, we demonstrate the efficient generation of uniform cell‐protrusion arrays (more than 5000 cells with protrusions) for a series of cell types. We show precise isolation of cell protrusions with high purity at single‐cell precision for subsequent RNA‐Seq analysis, which was further validated by RT‐qPCR and RNA FISH. Our highly controlled protrusion isolation method opens a new avenue for the study of subcellular functional mechanisms and signaling pathways in metastasis.
Regenerative robotics
Authors: Damian Dana D.
Published: June 2019

Congenital diseases requiring reconstruction of parts of the gastrointestinal tract, skin, or bone are a challenge to alleviate especially in rapidly growing children. Novel technologies may be the answer. This article presents the state‐of‐art in regenerative robotic technologies, which are technologies that assist tissues and organs to regenerate using sensing and mechanotherapeutical capabilities. It addresses the challenges in the development of such technologies, among which are autonomy and fault‐tolerance for long‐term therapy as well as morphological conformations and compliance of such devices to adapt to gradual changes of the tissues in vivo. The potential as medical devices for delivering therapies for tissue growth and as tools for scientific exploration of regenerative mechanisms is also discussed.
Nachrichten des Verbandes Biologie, Biowissenschaften & Biomedizin in Deutschland
Authors: Radermacher Margarete
Published: June 2019

Wissenschaft & Gesellschaft

Science bridges cultures – Wissenschaft verbindet

Ausbildung

Ars legendi‐Fakultätenpreis Biologie 2019 verliehen

Landesverbände & Fachgesellschaften

Arbeitskreise

AK Gesundheit und Biologie im VBIO

AK Schulbiologie
Pfeffer: Die Vielfalt der Aromata
Authors: Rösemann Ulrich
Published: June 2019

Noch vor 500 Jahren waren unsere Gerichte geschmacklos, denn Gewürze konnten nur über den Landweg von Asien nach Europa transportiert werden und waren somit den Reichen vorenthalten. Dies änderte sich erst nach Entdeckung der Seeroute. Vor allem mit Pfeffer wurde reger Handel getrieben und machte die Kaufleute reich. Bei echtem Pfeffer handelt es sich um verschiedene Zubereitungen der Früchte von Piper nigrum. Hinter dem Begriff verbirgt sich aber auch eine Vielzahl anderer Pflanzen, die als falscher Pfeffer zusammengefasst werden.
Three modes of psychotherapy and their requisite core skills
Authors: Lundh Lars‐Gunnar
Published: June 2019

The field of psychotherapy suffers from the lack of an integrative meta‐perspective on the large variety of existing psychotherapies and on the therapeutic skills involved. In the present paper, it is suggested that the development of a more comprehensive view of this field may be facilitated if we differentiate between three modes of psychotherapy, which require different therapeutic core skills: (a) an educational mode, which requires teaching skills; (b) a reparative mode, which requires analytic‐conceptualising skills to identify some kind of disordered functioning, in combination with specific relational‐technical skills to repair this dysfunction; and (c) a developmental mode, which involves engaging in a therapeutic relationship with patients to facilitate their personal growth, and which requires non‐directivity skills. In addition, some therapeutic skills (e.g., awareness and communication skills) may be more or less important in all modes of treatment. Concrete manifestations of the three different modes of psychotherapy are discussed in terms of five different theoretical perspectives on psychotherapy: the common factors, the humanistic‐experiential mindfulness cognitive‐behavioural (CBT) and psychodynamic perspective. The common factors model is criticised as being insufficient in several respects. Finally, it is argued that if personal therapeutic skills are essential to the effects of psychotherapy, then empirical research on psychotherapy needs to be re‐oriented towards a person‐oriented study of therapist skills in action, in the context of a study of the interaction between therapist and patient.
TiO2‐Based Photocatalysis at the Interface with Biology and Biomedicine
Authors: Tomás‐Gamasa María , Mascareñas José Luis
Published: June 2019

The conversion of sunlight into chemical energy by using photosynthetic machinery is at the heart of nature and life. Scientists have also learned to use light energy to promote a great variety of chemical reactions, most of which are based on redox processes involving electron‐transfer steps. Indeed, the area of photoredox catalysis has recently emerged as one of the hottest fields in synthetic chemistry. Many of the photoredox reactions discovered so far take place in homogeneous phases, and rely on the use of soluble photoresponsive catalysts. However, in recent years, there have been many advances in the area of heterogeneous photocatalysis, most of which are based on the use of semiconductor materials, such as TiO2, as a key photocatalytic system. These technologies have found different applications, especially in the field of sustainable chemistry and therapy. Herein, some of these applications, and the potential of TiO2‐based photocatalysts in biology and biomedicine, are reviewed.
In Situ Reaction Monitoring of Unstable Lithiated Intermediates through Inline FTIR Spectroscopy
Authors: Fath Verena , Kockmann Norbert , Röder Thorsten
Published: June 2019

Because a multitude of reactions with n‐butyllithium are of high industrial significance, an in‐depth process understanding is required to render potential scale‐up from the laboratory to production more efficient. The objective of this work is to illuminate the mechanism underlying the deprotonation reaction of a CH‐acidic hydrocarbon compound with n‐butyllithium. Combining microreactor technology with inline FTIR spectroscopy, it was possible to quickly determine reliable kinetic data. It is shown that a complex reaction mechanism is involved in the synthesis of a highly reactive, nonisolable, lithiated component. Several kinetic approaches are studied in detail, and a possible mechanism based on the formation of butyllithium aggregates in tetrahydrofuran is postulated.
Xenon Trioxide Adducts of O‐Donor Ligands; [(CH3)2CO]3XeO3, [(CH3)2SO]3(XeO3)2, (C5H5NO)3(XeO3)2, and [(C6H5)3PO]2XeO3
Authors: Marczenko Katherine M. , Goettel James T. , Mercier Hélène P. A. , Schrobilgen Gary J.
Published: June 2019

Xenon trioxide (XeO3) forms adducts with triphenylphosphine oxide, dimethylsulfoxide, pyridine‐N‐oxide, and acetone by coordination of the ligand oxygen atoms to the XeVI atom of XeO3. The crystalline adducts were characterized by low‐temperature, single‐crystal X‐ray diffraction, and Raman spectroscopy. Unlike solid XeO3, which detonates when mechanically or thermally shocked, solid (C5H5NO)3(XeO3)2, [(C6H5)3PO]2XeO3, and [(CH3)2SO]3(XeO3)2 are insensitive to mechanical shock. The [(CH3)2SO]3(XeO3)2 adduct slowly decomposes over several days to (CH3)2SO2, Xe, and O2. All three complexes undergo rapid deflagration when ignited by a flame. Both [(C6H5)3PO]2XeO3 and (C5H5NO)3(XeO3)2 are room‐temperature stable and the [(CH3)2CO]3XeO3 complex dissociates at room temperature to form a stable solution of XeO3 in acetone. The xenon coordination sphere of [(C6H5)3PO]2XeO3, a distorted square‐pyramid, provides the first example of a five‐coordinate XeO3 complex with only two Xe‐ ‐ ‐O adduct bonds. The xenon coordination spheres of the remaining adducts are distorted octahedra, comprised of three Xe‐ ‐ ‐O secondary bonds that are approximately trans to the primary Xe−O bonds of XeO3. Quantum‐chemical calculations were used to assess the nature of the Xe‐ ‐ ‐O adduct bonds, which are described as predominantly electrostatic bonds between the nucleophilic oxygen atoms of the bases and the σ‐holes of the electrophilic xenon atoms.
Structure and Mechanism of Ergothionase from Treponema denticola
Authors: Maurer Alice , Leisinger Florian , Lim David , Seebeck Florian P.
Published: June 2019

Ergothioneine is a sulfur‐containing histidine derivative that emerges from microbial biosynthesis and enters the human body through intestinal uptake and regulated distribution into specific tissues. Although the proteins involved in biosynthesis and uptake are well characterized, less is known about the degradative pathways of ergothioneine. This report describes the crystal structure of the active form of ergothionase from the oral pathogen Treponema denticola complexed with the substrate analogue desmethyl‐ergothioneine sulfonic acid. This enzyme catalyzes the 1,2‐elimination of trimethylamine from ergothioneine and ergothioneine sulfonic acid by using a unique mode of substrate activation combined with acid/base catalysis. This structural and mechanistic investigation revealed four essential catalytic residues, which are strictly conserved in homologous proteins from common gastrointestinal bacteria and numerous pathogenic bacteria, suggesting that bacterial activity may play an important role in determining the availability of ergothioneine in healthy and diseased human tissue.
Symmetry Reduction of Porphycenes with Finely Tuned Optical and Electronic Properties through Oxidative Cyclization of E/Z‐Mixed Dipyrroethenes
Authors: Xu Ning , Ono Toshikazu , Hisaeda Yoshio
Published: June 2019

The main obstacle to the widespread application of porphycenes lies in the lack of efficient and economical methods for their production. Discovery of new synthetic methodologies for porphycene derivatives are important for fine‐tuning of their optical and electrochemical properties. Herein, the preparation of a set of AABB‐, ABAB‐, and ABBA‐type meso‐tetrasubstituted unsymmetric porphycenes is reported. Their synthesis involved the acid‐catalyzed oxidative coupling of AA‐ and BB‐dipyrroethenes, or AB‐type dipyrroethenes, as precursors in yields of up to 19 %. The structures were unambiguously confirmed by X‐ray crystallography. The type and position of substituents in the unsymmetric porphycenes enabled fine‐tuning of the optical and electronic properties, which are discussed in terms of their UV/Vis absorption, fluorescence spectroscopies, cyclic voltammetry, and density functional theory calculations.
Near‐Infrared Circularly Polarized Luminescence through Intramolecular Excimer Formation of Oligo(p‐phenyleneethynylene)‐Based Double Helicates
Authors: Miki Koji , Noda Takeru , Gon Masayuki , Tanaka Kazuo , Chujo Yoshiki , Mizuhata Yoshiyuki , Tokitoh Norihiro , Ohe Kouichi
Published: June 2019

Invited for the cover of this issue is the group of Koji Miki, Kouichi Ohe, and colleagues at Kyoto University. The image depicts mythical dragons as carbon‐based double helicates. Read the full text of the article at 10.1002/chem.201901467.
Reaction between methanol and acetic acid catalyzed by SiO2‐supported V‐P‐O catalyst in oxygen atmosphere
Authors: Shen Lingqin , Yu Zhongyong , Wang Aili , Yin Hengbo
Published: June 2019

SiO2‐supported V‐P‐O catalysts prepared by the incipient‐wetness impregnation method beginning with ammonium metavanadate and phosphoric acid were used in the catalytic reaction between methanol and acetic acid in an oxygen atmosphere. The SiO2‐supported V‐P‐O catalysts were composed of VOPO4 and (VO)2P2O7 phases. Both the acidic and alkaline sites were co‐present in the catalysts. The vanadium species catalyzed the oxidation of methanol to formaldehyde. The V‐P‐O(20–30 wt%)/SiO2 catalysts with a P/V mole ratio of 2:1 exhibited higher catalytic activity for the formation of acrylic acid and methyl acrylate with a total selectivity of ∼28  % at 380 °C. The acid sites of the catalysts also catalyzed the formation of methyl acetate with a selectivity of ∼65 %. Methanol can be an alternative to formaldehyde for the synthesis of both acrylic acid and methyl acrylate through the aldol condensation reaction.
Effect of Cation Size on Solvation and Association with Superoxide Anion in Aprotic Solvents
Authors: Smirnov Vladimir S. , Kislenko Sergey A.
Published: June 2019

Influence of cation size on solvation strength, diffusion, and kinetics of the association reaction with anions O2− in aprotic solvents, such as acetonitrile and dimethyl sulfoxide, has been investigated by means of molecular dynamics simulations. The work is motivated by the need to understand the molecular nature of the solvent‐induced changes in capacity of Li‐air batteries. We have shown that the dependence of the solvation shell stability on the cation size has a maximum at a particular ion radius that corresponds to a solvent coordination number of 4. The shell stability maximum coincides with the diffusion coefficient minimum. The variation of the cation shell stability has a crucial impact on the kinetics of the cation‐O2− association. We have demonstrated that profound inhibition of the association reaction for Li+ in dimethyl sulfoxide is a result of the lock‐and‐key effect that cannot be described in the framework of Hard Soft Acid Base theory.
Doxorubicin‐Induced Cardiomyopathy in Children
Authors: Mancilla Trevi R. , Iskra Brian , Aune Gregory J.
Published: June 2019

Doxorubicin‐induced cardiotoxicity in childhood cancer survivors is a growing problem. The population of patients at risk for cardiovascular disease is steadily increasing, as five‐year survival rates for all types of childhood cancers continue to improve. Doxorubicin affects the developing heart differently from the adult heart and in a subset of exposed patients, childhood exposure leads to late, irreversible cardiomyopathy. Notably, the prevalence of late‐onset toxicity is increasing in parallel with improved survival. By the year 2020, it is estimated that there will be 500,000 childhood cancer survivors and over 50,000 of them will suffer from doxorubicin‐induced cardiotoxicity.

The majority of the research to‐date, concentrated on childhood cancer survivors, has focused mostly on clinical outcomes through well‐designed epidemiological and retrospective cohort studies. Preclinical studies have elucidated many of the cellular mechanisms that elicit acute toxicity in cardiomyocytes. However, more research is needed in the areas of early‐ and late‐onset cardiotoxicity and more importantly improving the scientific understanding of how other cells present in the cardiac milieu are impacted by doxorubicin exposure.

The overall goal of this review is to succinctly summarize the major clinical and preclinical studies focused on doxorubicin‐induced cardiotoxicity. As the prevalence of patients affected by doxorubicin exposure continues to increase, it is imperative that the major gaps in existing research are identified and subsequently utilized to develop appropriate research priorities for the coming years. Well‐designed preclinical research models will enhance our understanding of the pathophysiology of doxorubicin‐induced cardiotoxicity and directly lead to better diagnosis, treatment, and prevention. © 2019 American Physiological Society.Compr Physiol9:905‐931, 2019.
Regulation of the Cerebral Circulation by Arterial Carbon Dioxide
Authors: Hoiland Ryan L. , Fisher Joseph A. , Ainslie Philip N.
Published: June 2019

Intact, coordinated, and precisely regulated cerebrovascular responses are required for the maintenance of cerebral metabolic homeostasis, adequate perfusion, oxygen delivery, and acid‐base balance during deviations from homeostasis. Increases and decreases in the partial pressure of arterial carbon dioxide (PaCO2) lead to robust and rapid increases and decreases in cerebral blood flow (CBF). In awake and healthy humans, PaCO2is the most potent regulator of CBF, and even small fluctuations can result in large changes in CBF. Alterations in the responsiveness of the cerebral vasculature can be detected with carefully controlled stimulus‐response paradigms and hold relevance for cerebrovascular risk in steno‐occlusive disease. As changes in PaCO2do not typically occur in isolation, the integrative influence of physiological factors such as intracranial pressure, arterial oxygen content, cerebral perfusion pressure, and sympathetic nervous activity must be considered. Further, age and sex, as well as vascular pathologies are also important to consider. Following a brief summary of key historical events in the development of our understanding of cerebrovascular physiology and an overview of the measurement techniques to index CBF this review provides an in‐depth description of CBF regulation in response to alterations in PaCO2. Cerebrovascular reactivity and regional flow distribution are described, with further consideration of how differences in reactivity of parallel networks can lead to the “steal” phenomenon. Factors that influence cerebrovascular reactivity are discussed and the mechanisms and regulatory pathways mediating the exquisite sensitivity of the cerebral vasculature to changes in PaCO2are outlined. Finally, topical avenues for future research are proposed. © 2019 American Physiological Society.Compr Physiol9:1101‐1154, 2019.
Long Noncoding RNA: Genomics and Relevance to Physiology
Authors: Kong Yiwei , Lu Zeyuan , Liu Pengyuan , Liu Yong , Wang Feng , Liang Eugene Y. , Hou Fan Fan , Liang Mingyu
Published: June 2019

The mammalian cell expresses thousands of long noncoding RNAs (lncRNAs) that are longer than 200 nucleotides but do not encode any protein. lncRNAs can change the expression of protein‐coding genes through bothcisandtransmechanisms, including imprinting and other types of transcriptional regulation, and posttranscriptional regulation including serving as molecular sponges. Deep sequencing, coupled with analysis of sequence characteristics, is the primary method used to identify lncRNAs. Physiological roles of specific lncRNAs can be examined using genetic targeting or knockdown with modified oligonucleotides. Identification of nucleic acids or proteins with which an lncRNA interacts is essential for understanding the molecular mechanism underlying its physiological role. lncRNAs have been reported to contribute to the regulation of physiological functions and disease development in several organ systems, including the cardiovascular, renal, muscular, endocrine, digestive, nervous, respiratory, and reproductive systems. The physiological role of the majority of lncRNAs, many of which are species and tissue specific, remains to be determined. © 2019 American Physiological Society.Compr Physiol9:933‐946, 2019.
Geschosswohnungsbau mit monolithischem Mauerwerk aus Leichtbeton
Authors: Kranzler Thomas
Published: June 2019

Affordable living space has become one of the main talking points in Germany next to the threat of climate change. The SMEs of the German lightweight concrete industry offer regional masonry solutions for detached, semi‐detached, and terraced houses as well as multi‐storey apartment buildings.

Particularly in densely populated urban centres, the need for multi‐storey apartment buildings arises constantly. In the following the performance of monolithic lightweight concrete masonry will be described and compared with the relevant requirements for multi‐storey apartment buildings. It will be demonstrated that masonry with supposedly low compressive strength can still fulfil all requirements. Of particular significance here are the external wall‐slab junctions.
Neonatal EEG linked to individual differences in socioemotional outcomes and autism risk in toddlers
Authors: Brito Natalie H. , Elliott Amy J. , Isler Joseph R. , Rodriguez Cynthia , Friedrich Christa , Shuffrey Lauren C. , Fifer William P.
Published: June 2019

Research using electroencephalography (EEG) as a measure of brain function and maturation has demonstrated links between cortical activity and cognitive processes during infancy and early childhood. The current study examines whether neonatal EEG is correlated with later atypical socioemotional behaviors or neurocognitive delays. Parental report developmental assessments were administered to families with children ages 24 to 36 months who had previously participated in a neonatal EEG study (N = 129). Significant associations were found between neonatal EEG (higher frequencies in the frontal polar, temporal, and parietal brain regions) and BITSEA ASD risk scores. Infants with lower EEG power in these brain areas were more likely to have higher risk of socioemotional problems. When examining sex differences, significant links were found for males but not for females. These results demonstrate some promising associations between early neural biomarkers and later risk for atypical behaviors, which may shape early neurobehavioral development and could lead to earlier identification and intervention.
Current and future potential distributions of three Dracaena Vand. ex L. species under two contrasting climate change scenarios in Africa
Authors: Bogawski Paweł , Damen Theo , Nowak Maciej M. , Pędziwiatr Katarzyna , Wilkin Paul , Mwachala Geoffrey , Pierzchalska Joanna , Wiland‐Szymańska Justyna
Published: June 2019

Forest undergrowth plants are tightly connected with the shady and humid conditions that occur under the canopy of tropical forests. However, projected climatic changes, such as decreasing precipitation and increasing temperature, negatively affect understory environments by promoting light‐demanding and drought‐tolerant species. Therefore, we aimed to quantify the influence of climate change on the spatial distribution of three selected forest undergrowth plants, Dracaena Vand. ex L. species, D. afromontana Mildbr., D. camerooniana Baker, and D. surculosa Lindl., simultaneously creating the most comprehensive location database for these species to date.

A total of 1,223 herbarium records originating from tropical Africa and derived from 93 herbarium collections worldwide have been gathered, validated, and entered into a database. Species‐specific Maxent species distribution models (SDMs) based on 11 bioclimatic variables from the WorldClim database were developed for the species. HadGEM2‐ES projections of bioclimatic variables in two contrasting representative concentration pathways (RCPs), RCP2.6 and RCP8.5, were used to quantify the changes in future potential species distribution.

D. afromontana is mostly sensitive to temperature in the wettest month, and its potential geographical range is predicted to decrease (up to −63.7% at RCP8.5). Optimum conditions for D. camerooniana are low diurnal temperature range (6–8°C) and precipitation in the wettest season exceeding 750 mm. The extent of this species will also decrease, but not as drastically as that of D. afromontana. D. surculosa prefers high precipitation in the coldest months. Its potential habitat area is predicted to increase in the future and to expand toward the east.

This study developed SDMs and estimated current and future (year 2050) potential distributions of the forest undergrowth Dracaena species. D. afromontana, naturally associated with mountainous plant communities, was the most sensitive to predicted climate warming. In contrast, D. surculosa was predicted to extend its geographical range, regardless of the climate change scenario.
From microsatellites to single nucleotide polymorphisms for the genetic monitoring of a critically endangered sturgeon
Authors: Roques Séverine , Chancerel Emilie , Boury Christophe , Pierre Maud , Acolas Marie‐Laure
Published: June 2019

The use of genetic information is crucial in conservation programs for the establishment of breeding plans and for the evaluation of restocking success. Short tandem repeats (STRs) have been the most widely used molecular markers in such programs, but next‐generation sequencing approaches have prompted the transition to genome‐wide markers such as single nucleotide polymorphisms (SNPs). Until now, most sturgeon species have been monitored using STRs. The low diversity found in the critically endangered European sturgeon (Acipenser sturio), however, makes its future genetic monitoring challenging, and the current resolution needs to be increased. Here, we describe the discovery of a highly informative set of 79 SNPs using double‐digest restriction‐associated DNA (ddRAD) sequencing and its validation by genotyping using the MassARRAY system. Comparing with STRs, the SNP panel proved to be highly efficient and reproducible, allowing for more accurate parentage and kinship assignments' on 192 juveniles of known pedigree and 40 wild‐born adults. We explore the effectiveness of both markers to estimated relatedness and inbreeding, using simulated and empirical datasets. Interestingly, we found significant correlations between STRs and SNPs at individual heterozygosity and inbreeding that give support to a reasonable representation of whole genome diversity for both markers. These results are useful for the conservation program of A. sturio in building a comprehensive studbook, which will optimize conservation strategies. This approach also proves suitable for other case studies in which highly discriminatory genetic markers are needed to assess parentage and kinship.
To improve ecological understanding, collect infection data
Authors: Gehman Alyssa‐Lois M. , Satterfield Dara A. , Keogh Carolyn L. , McKay Alexa Fritzsche , Budischak Sarah A.
Published: June 2019

Ecologists seek to understand and predict how organisms respond to multiple interacting biotic and abiotic influences, an increasingly difficult task under anthropogenic change. Parasites are one of these biotic influences that are pervasive in natural systems and frequently interact with other stressors. Because they often have cryptic effects on their host organisms, their role in the distribution, abundance, composition, and dynamics of populations, communities, and ecosystems is easy to overlook. However, studies that neglect the role of parasitism may miss or misinterpret organismal responses to environmental change, hampering ecological predictions. We discuss case studies wherein the inclusion of parasite infection status altered the interpretation of ecological outcomes, and offer paths forward to make parasite data acquisition, analysis, and interpretation more accessible to ecologists. Given that parasites are responsive to environmental changes, timely attention to their influence on host responses is critical for accurately predicting future ecological states.