bluuebunny/crossref_metadata_2025 huggingface dataset:
Circuits that encode and guide alcohol-associated preference
Authors: Scaplen Kristin M , Talay Mustafa , Nunez Kavin M , Salamon Sarah , Waterman Amanda G , Gang Sydney , Song Sophia L , Barnea Gilad , Kaun Karla R
Published: June 2020

A powerful feature of adaptive memory is its inherent flexibility. Alcohol and other addictive substances can remold neural circuits important for memory to reduce this flexibility. However, the mechanism through which pertinent circuits are selected and shaped remains unclear. We show that circuits required for alcohol-associated preference shift from population level dopaminergic activation to select dopamine neurons that predict behavioral choice inDrosophila melanogaster. During memory expression, subsets of dopamine neurons directly and indirectly modulate the activity of interconnected glutamatergic and cholinergic mushroom body output neurons (MBON). Transsynaptic tracing of neurons important for memory expression revealed a convergent center of memory consolidation within the mushroom body (MB) implicated in arousal, and a structure outside the MB implicated in integration of naïve and learned responses. These findings provide a circuit framework through which dopamine neuronal activation shifts from reward delivery to cue onset, and provide insight into the maladaptive nature of memory.
Feedback contribution to surface motion perception in the human early visual cortex
Authors: Marquardt Ingo , De Weerd Peter , Schneider Marian , Gulban Omer Faruk , Ivanov Dimo , Wang Yawen , Uludağ Kâmil
Published: June 2020

Human visual surface perception has neural correlates in early visual cortex, but the role of feedback during surface segmentation in human early visual cortex remains unknown. Feedback projections preferentially enter superficial and deep anatomical layers, which provides a hypothesis for the cortical depth distribution of fMRI activity related to feedback. Using ultra-high field fMRI, we report a depth distribution of activation in line with feedback during the (illusory) perception of surface motion. Our results fit with a signal re-entering in superficial depths of V1, followed by a feedforward sweep of the re-entered information through V2 and V3. The magnitude and sign of the BOLD response strongly depended on the presence of texture in the background, and was additionally modulated by the presence of illusory motion perception compatible with feedback. In summary, the present study demonstrates the potential of depth-resolved fMRI in tackling biomechanical questions on perception.
Bee diversity in secondary forests and coffee plantations in a transition between foothills and highlands in the Guatemalan Pacific Coast
Authors: Armas-Quiñonez Gabriela , Ayala-Barajas Ricardo , Avendaño-Mendoza Carlos , Lindig-Cisneros Roberto , del-Val Ek
Published: June 2020

Background

Although conservation of pristine habitats is recognized in many countries as crucial for maintaining pollinator diversity, the contribution of secondary forest conservation is poorly recognized in the Latin American context, such as in Guatemala. San Lucas Tolimán (SLT) is a high-quality coffee production region from the Atitlan Province, which has the second highest deciduous forest cover in Guatemala and pristine forest is prioritized for conservation. In contrast, secondary forest protection is undetermined, since these forests are normally removed or strongly affected by coffee farming practices. This situation may affect the diversity of native pollinators, mainly bees, which usually rely on the secondary forest for food resources.

Methods

We conducted a study to investigate the importance of secondary forests around the SLT coffee plantations (Coffea arabicaL.) for pollinators. We compared bee diversity (richness, abundance and composition) in secondary forests of different age and coffee plantations with diverse farming techniques. Being the first study of pollinators in Guatemalan coffee plantations, we also recorded data for an entire year (2013–2014) in order to describe bee seasonality.

Results

We found significant differences in bee diversity between the coffee plantations and secondary forests, particularly early secondary forests showed higher bee abundances but diversity indices were similar between different vegetation type plots. In the early dry season, secondary forests showed the greatest native bee diversity. During the late dry season, when the coffee was flowering, honey bees were dominant in the same plots. This study provides important management insights to support the conservation of pollinators, since our results offer guidelines to improve coffee production by increasing native pollinator diversity.
Exogenous hormones influence Brassica napus leaf cuticular wax deposition and cuticle function
Authors: Yuan Zheng , Jiang Youwei , Liu Yuhua , Xu Yi , Li Shuai , Guo Yanjun , Jetter Reinhard , Ni Yu
Published: June 2020

Background

Cuticular waxes cover plant surface and play important roles in protecting plants from abiotic and biotic stresses. The variations of wax deposition and chemical compositions under changing environments have been shown to be related to plant adaptations. However, it is still not clear whether the wax depositions could be adjusted to increase plant adaptations to stressed conditions.

Methods

In this study, exogenous methyl jasmonate (MeJA), the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) and salicylic acid (SA) were applied to test their effects on cuticular wax deposition in two Brassica napus cultivars, Zhongshuang 9 (ZS9, low wax coverage ) and Yuyou 19 (YY19, high wax coverage). Next, we measured the water loss rate and the transcriptional expression of genes involved in wax biosynthesis as well as genes related to disease defense.

Results

Seven wax compound classes, including fatty acids, aldehydes, alkanes, secondary alcohols, ketones, and unbranched as well as branched primary alcohols, were identified in B. napus leaf wax mixtures. MeJA, SA and ACC treatments had no significant effect on total wax amounts in YY19, whereas ACC reduced total wax amounts in ZS9. Overall, hormone treatments led to an increase in the amounts of aldehydes and ketones, and a decrease of secondary alcohol in ZS9, whereas they led to a decrease of alkane amounts and an increase of secondary alcohol amounts in YY19. Concomitantly, both cultivars also exhibited different changes in cuticle permeability, with leaf water loss rate per 15 min increased from 1.57% (averaged across treatments) at 1.57% (averaged across treatments) at 15 min to 3.12% at 30 min for ZS9 (except for ACC treated plant) and decreased for YY19. MeJA-treated plants of both cultivars relatively had higher water loss rate per 15 min when compared to other treatments. Conclusion. Our findings that B. napus leaf wax composition and cuticle permeability are altered by exogenous SA, MeJA and ACC suggest that the hormone treatments affect wax composition, and that the changes in wax profiles would cause changes in cuticle permeability.
Evaluation of Fungicides against Ustilaginoidea virens Pathogen Causing False Smut Disease of Rice
Authors: Kumar Uday , Azad C. S. , Shekhar Sumit , Kumari Jyoti , Kumar Sanjeev , Kumar Amarendra
Published: June 2020

False smut of rice caused by Ustilaginoidea virens is most destructive disease of rice causing 5-85 per cent yield losses in India. In the present investigations, six novel fungicides viz., Flusilazole 25% + Carbendazim 12.5% SE, Trifloxystrobin 25% + Tebuconazole 50% WG, Carbendazim 12% + Mancozeb 63% WP, Azoxystrobin 18.2% + Difenoconazole 11.4% SC, Azoxystrobin 11% + Tebuconazole 18.3% W/W and Copper hydroxide 50% WP were tested in vitro against the false smut of rice pathogen Ustilaginoidea virens. The maximum mycelial growth was observed in case of Copper hydroxide 50% WP (21.20 mm) as compare to control (60.70 mm) after 21 days incubation. All the fungicides significantly inhibited the fungal mycelial growth in all concentrations (10, 25, 50, 75 and 100 ppm). Among six fungicides evaluated under in vitro condition Trifloxystrobin 25% + Tebuconazole 50% WG showed highest mycelial growth inhibition (86.66%) at 100 ppm followed by Flusilazole 25% + Carbendazim 12.5% SE (78.91%) whereas least mycelial inhibition was recorded in case of Copper hydroxide 50% WP (65.07%) after 21 days of incubation.
Matrix Isolation Spectroscopy in Atmospheric Chemistry – Structure and Reactions of Atmospherically Important Species
Authors: Karir Ginny , Viswanathan K.S.
Published: June 2020

Atmospheric chemistry has today grown from being a curiosity‐driven science to one that is necessity driven. A plethora of experimental and computational tools are used today to study the chemistry of our atmosphere, in an effort to preserving its health. In this article, we review the use of matrix isolation spectroscopy in the study of atmospheric processes. Most of the chemical reactions in the atmosphere are driven by light and hence photochemical studies of species present in the atmosphere are of great interest. Furthermore, atmospheric chemistry is also dominated by photochemically induced free radical chemistry, and hence techniques to study these reactive species must be resorted to. Matrix isolation spectroscopy is ideally suited for photochemical studies and for the study of reactive short‐lived species and has, therefore, been extensively used. In this article, we particularly discuss the chemistry and the role played by species such as OH
⋅
radicals, NO
3
radicals, and O
3
together with a variety of reactive species involving Br, F, and S. The use and chemistry of alternatives for
chlorofluorocarbon
s (
CFC
s) are also discussed. As a result of the various studies, it has now become possible to understand the role of various species in the atmosphere and therefore to evolve administrative regulations that seek to preserve the health of the atmosphere.
DNA
‐Enabled Heavy Metal Detection in Water
Authors: Moon Woohyun J. , Huang Po‐Jung J. , Liu Juewen
Published: June 2020

Detection of heavy metal contamination in the environment is an on‐going analytical challenge. In effort of developing portable biosensors, deoxyribonucleic acid (DNA)‐based designs have gained much attention for their high affinity and specificity to metals, stability, cost‐efficiency, ease of modification, and batch‐to‐batch reproducibility. Specific sequences of DNA aptamers and DNAzymes provide grounds for rational designs of fluorescent, colorimetric, and electrochemical detection methods. Aptamers exert only a binding function, while DNAzymes can use heavy metals to catalyze specific chemical and biological transformations. This article starts with a brief introduction of heavy metals and their interactions with DNA. Then DNA aptamers and DNAzymes are respectively reviewed from their in vitro selection, representative DNA sequences, and design of biosensors. For signal transduction, various fluorescent, colorimetric, and electrochemical examples are described. Finally, future perspectives are discussed.
Sexual objectification increases retaliatory aggression
Authors: Poon Kai‐Tak , Jiang Yufei
Published: June 2020

Two experiments were conducted to investigate whether sexual objectification increases retaliatory aggression serially through increased vulnerability and hostile intent attributions. Female participants were first exposed to the sexual objectification manipulation by receiving compliments from an online male partner (Experiment 1) or imagining a workplace objectification experience (Experiment 2). Afterward, their vulnerability and hostile intent attributions were assessed. Finally, they were given an opportunity to behave aggressively toward the source of objectification. The results of both experiments indicated that, compared with their counterparts in the control conditions, participants in the sexual objectification condition reported higher levels of vulnerability, hostile intent attributions, and aggression. Moreover, vulnerability and hostile intent attributions serially mediated the effect of sexual objectification on aggression. These findings highlight the critical influence of vulnerability and hostile intent attributions in understanding how sexual objectification increases aggression.
Clinical implication of serum biomarkers and patient age in inflammatory demyelinating diseases
Authors: Lee Eun‐Jae , Lim Young‐Min , Kim Seungmi , Choi Lynkyung , Kim Hyunjin , Kim Keonwoo , Kim Hye Weon , Lee Ji Sung , Kim Kwang‐Kuk
Published: June 2020

Objectives

Serum synaptic proteins levels may change with age‐related neurodegeneration, affecting their clinical implications as a disease biomarker. We aimed to investigate neuronal and astroglial markers in patients with multiple sclerosis (MS) and aquaporin‐4 antibody‐seropositive neuromyelitis optica spectrum disorders (NMOSD) to compare the clinical implications of these markers according to age.

Methods

Using single‐molecule array assays, we measured neurofilament light (NfL) and glial fibrillary acidic protein (GFAP) in sera from consecutive patients with MS (n = 117) and NMOSD (n = 63). For each disease, we assessed correlations between these markers and disease severity (Expanded Disability Status Scale [EDSS]) scores according to three age groups (≤44, 45–54, and ≥55 years).

Results

Although serum GFAP levels were significantly higher in patients with NMOSD than those with MS, levels of both serum markers revealed significant positive correlations with EDSS scores in both diseases. In MS patients, the degrees of correlation between serum NfL (or GFAP) levels and EDSS scores were similar across all age groups. However, in NMOSD patients, positive GFAP‐EDSS correlations were distinctively stronger in the youngest than in the oldest group. Conversely, there were no positive NfL‐EDSS correlations in NMOSD in the youngest group, but there were significant in the oldest group.

Interpretation

The degrees to which serum NfL and GFAP levels reflect disease severity vary significantly with patient age in NMOSD, but not in MS. These findings suggest that the pathological processes and progression differ between the diseases; hence, serum biomarker levels may need to be interpreted differently according to patient age and disease type.
Utility of metabolic screening in neurological presentations of infancy
Authors: Djordjevic Djurdja , Tsuchiya Etsuko , Fitzpatrick Megan , Sondheimer Neal , Dowling James J.
Published: June 2020

Background

The first‐line use of specialized metabolic screening laboratories in the investigation of hypotonia and/or developmental delay remains a standard practice despite lack of supporting evidence. Our study aimed to address the utility of such testing by determining the proportion of patients whose diagnosis was directly supported by metabolic screening.

Methods

We performed a retrospective chart review study of 164 patients under age one who had screening metabolic laboratory testing done within the time period of one calendar year.

Results

Of patients screened, 9/164 (5.5%) had diagnoses supported by metabolic testing (two with nonketotic hyperglycinemia, three with ornithine transcarbamylase deficiency, one with propionic acidemia, one with a congenital disorder of glycosylation, one with D‐bifunctional protein deficiency, and one with GM1 Gangliosidosis). Of patients specifically evaluated for hypotonia and/or developmental delay, 5/79 (6.3%) were diagnosed with the aid of metabolic testing. All patients with positive screens presented with acute decompensation. Outside of this subgroup of high‐risk patients, no patients were diagnosed using metabolic testing. Screening laboratories were also ineffective in an outpatient setting, identifying only one of the seven outpatients who was ultimately diagnosed with an inborn error of metabolism.

Conclusions

These findings demonstrate that the yield of specialized metabolic screening testing is extremely low in infants with hypotonia and/or developmental delay, approaching zero outside of the specific setting of clinical decompensation or multi‐system involvement. Furthermore, many outpatient cases of IEM are not identified by screening studies. This information will help guide the diagnostic evaluation of hypotonia and/or global developmental delay.
Early prediction of adverse outcomes in infants with acute bilirubin encephalopathy
Authors: Kang Wenqing , Yuan Xiao , Zhang Yaodong , Song Juan , Xu Falin , Liu Dapeng , Li Rui , Xu Bangli , Li Wen , Cheng Yanchao , Zhu Changlian
Published: June 2020

Objective

Acute bilirubin encephalopathy (ABE) remains one of the important causes of neonatal mortality and child disability, early identification, and intervention which could improve outcomes. The purpose of this study was to evaluate early predictors of adverse outcomes in infants with ABE.

Methods

Newborns of gestational age ≥ 35 weeks and diagnosed with ABE were included in the study. Bilirubin‐induced neurological dysfunction (BIND) score, total serum bilirubin (TSB) peak value, and serum albumin levels were determined. Adverse outcomes were defined as death or survival with auditory dysfunction and/or cerebral palsy.

Results

Eighty‐two infants were eligible for recruitment in the study. The outcome data from 76 ABE infants (92%) were used for analysis, of which 25 infants got adverse outcomes and 51 live a normal life. Univariate analysis for BIND score, TSB peak value, bilirubin–albumin ratio (B/A), albumin level, abnormal AABR, and neonatal sepsis was performed to elucidate the association with adverse outcomes. Bivariate logistic regression analysis showed B/A (OR 10.48, 95%CI: 1.55–70.81, P = 0.02) and BIND score (OR 3.68, 95%CI: 1.39–9.72, P = 0.01) were correlated with adverse outcomes. ROC curve analysis showed that B/A (≥8.9 mg/g), BIND score (≥6) could predict adverse outcomes of ABE separately; B/A in conjunction with BIND score could increase prediction sensitivity to 100%.

Interpretation

Both B/A and BIND score can be used to predict adverse outcomes of ABE, and the combination of the two parameters can increase prediction sensitivity significantly.
Trilayer Nanomesh Films with Tunable Wettability as Highly Transparent, Flexible, and Recyclable Electrodes
Authors: Qiu Tengfei , Luo Bin , Akinoglu Eser Metin , Yun Jung‐Ho , Gentle Ian R. , Wang Lianzhou
Published: June 2020

Metallic mesh materials are promising candidates to replace traditional transparent conductive oxides such as indium tin oxide (ITO) that is restricted by the limited indium resource and its brittle nature. The challenge of metal based transparent conductive networks is to achieve high transmittance, low sheet resistance, and small perforation size simultaneously, all of which significantly relate to device performances in optoelectronics. In this work, trilayer dielectric/metal/dielectric (D/M/D) nanomesh electrodes are reported with precisely controlled perforation size, wire width, and uniform hole distribution employing the nanosphere lithography technique. TiO2/Au/TiO2 nanomesh films with small hole diameter (≤700 nm) and low thickness (≤50 nm) are shown to yield high transmittance (>90%), low sheet resistance (≤70 Ω sq−1), as well as outstanding flexural endurance and feasibility for large area patterning. Further, by tuning the surface wettability, these films are applied as easily recyclable flexible electrodes for electrochromic devices. The simple and cost‐effective fabrication of diverse D/M/D nanomesh transparent conductive films with tunable optoelectronic properties paves a way for the design and realization of specialized transparent electrodes in optoelectronics.
Moiré‐Pattern‐Tuned Electronic Structures of van der Waals Heterostructures
Authors: Tang Kewei , Qi Weihong
Published: June 2020

Moiré patterns are quasi‐periodic geometric patterns generated by the incommensurate stacking between two monolayers; they have rapidly attracted enormous attention due to their profound ability to modulate the electronic properties of 2D materials. For instance, the Bloch band of the Moiré superlattice, which is known as the Moiré band, can become flat at a specific series of discrete angles, and these flat bands are capable of exhibiting strong correlation behaviors such as the high‐temperature superconductivity reported recently. Moiré patterns can alter electronic properties, while surface reconstruction can modify Moiré patterns. In this review, the fundamental geometry is discussed and the basic electronic structure modification is summarized. Surface reconstruction is a method of tuning the electronic properties of a Moiré superlattice. Strong correlation phenomena, such as superconductivity, superfluidity, and magnetism induced by the flat bands, have been confirmed experimentally in recent years, which will be discussed in detail. Some possible application opportunities based on the fascinating characteristics of the Moiré pattern will also be presented. Because of the growing interest in Moiré patterns and related physical phenomena, it is anticipated that a deeper understanding of the fundamental physics of Moiré systems and further progress in the investigation of strong correlation phenomena are forthcoming.
Iron Oxide Nanoparticles as T1 Contrast Agents for Magnetic Resonance Imaging: Fundamentals, Challenges, Applications, and Prospectives
Authors: Jeon Mike , Halbert Mackenzie V. , Stephen Zachary R. , Zhang Miqin
Published: June 2020

Gadolinium‐based chelates are a mainstay of contrast agents for magnetic resonance imaging (MRI) in the clinic. However, their toxicity elicits severe side effects and the Food and Drug Administration has issued many warnings about their potential retention in patients’ bodies, which causes safety concerns. Iron oxide nanoparticles (IONPs) are a potentially attractive alternative, because of their nontoxic and biodegradable nature. Studies in developing IONPs as T1 contrast agents have generated promising results, but the complex, interrelated parameters influencing contrast enhancement make the development difficult, and IONPs suitable for T1 contrast enhancement have yet to make their way to clinical use. Here, the fundamental principles of MRI contrast agents are discussed, and the current status of MRI contrast agents is reviewed with a focus on the advantages and limitations of current T1 contrast agents and the potential of IONPs to serve as safe and improved alternative to gadolinium‐based chelates. The past advances and current challenges in developing IONPs as a T1 contrast agent from a materials science perspective are presented, and how each of the key material properties and environment variables affects the performance of IONPs is assessed. Finally, some potential approaches to develop high‐performance and clinically relevant T1 contrast agents are discussed.
Highly Efficient Broadband Solar‐Blind UV Photodetector Based on Gd2O3:Eu3+–PMMA Composite Film
Authors: Jia Hong , Li Xue , Fan Yidan , Ding Chaoliang , Pan Liuzhan , Feng Xun , Liu Xiaofeng , Hu Junhua , Chen Jianguo , Gao Linhui , Chen Zhi , Qiu Jianrong
Published: June 2020

Due to their broad applications in civil and military fields, solar‐blind ultraviolet (UV) photodetectors have been paid with growing interest in recent years. Among lots of emerging materials exploited as spectral convertors for such photodetectors, rare‐earth (RE) ion‐activated downconversion (DC) materials show high quantum efficiency under UV excitation. However, up to date, RE ion‐based DC materials for solar‐blind UV converting photodetector can only enable UV detection in a narrow spectral region based on different device configurations. Herein, a highly efficient broadband solar‐blind UV photodetector constructed by coating a silicon‐based photosensitive resistor (Si‐BPR) with a transparent polymer composite film containing Gd2O3:Eu3+particles is presented. In the design, Gd2O3:Eu3+phosphor particles with efficient UV‐excited DC luminescence are mixed with poly(methyl methacrylate) to form a transparent composite film, which serves as an effective spectral converter for the conversion of broadband solar‐blind UV light to visible light, and this downconverted visible light can ultimately be absorbed by Si‐BPR to produce photoresponse. The result provides a facile approach for highly efficient broadband solar‐blind UV detection and may enable novel applications of RE‐activated hybrid luminescent films.
Eine einfache Strategie zur Korrektur des Fehlers aufgrund von Hexosylierung bei relativer Quantifizierung der N‐Glykosylierungsvarianten von Biopharmazeutika
Authors: Esser‐Skala Wolfgang , Wohlschlager Therese , Regl Christof , Huber Christian G.
Published: June 2020

N‐Glykane können sich auf die Sicherheit und Wirksamkeit von Biopharmazeutika auswirken, weswegen sie bei deren Herstellung kontrolliert werden. Zur Charakterisierung von Glykosylierungsvarianten wird vermehrt Massenspektrometrie auf intakter Proteinebene herangezogen. Allerdings kann die Quantifizierung von N‐Glykoformen bei dieser Methode durch Anwesenheit einzelner Hexosereste als Folge von Glykierung oder O‐Glykosylierung verfälscht werden. Hier beschreiben wir eine einfache Strategie zur Bestimmung der tatsächlichen Häufigkeiten von N‐Glykoformen therapeutischer Antikörper, wobei zunächst das Ausmaß der Glykierung experimentell bestimmt und anschließend die “Hexosylierungsabweichung” rechnerisch korrigiert wird. Wir zeigen, dass die tatsächlichen Häufigkeiten von N‐Glykoformen deutlich von den ursprünglich gemessenen Werten abweichen können. Tatsächlich kann Glykierung beträchtliche Unterschiede im N‐Glykosylierungsmuster von Arzneimittelchargen maskieren. Folglich könnten sich unsere Beobachtungen auf die biopharmazeutische Qualitätssicherung auswirken. Darüber hinaus lösen wir einen generellen Fall des für die Massenspektrometrie fundamentalen Problems der Isobarizität.
Halogen Bonding Between Anions: Association of Anion Radicals of Tetraiodo‐p‐benzoquinone with Iodide Anions
Authors: Maxson Tristan , Jalilov Almaz S. , Zeller Matthias , Rosokha Sergiy V.
Published: June 2020

Halogen bonding between two negatively charged species, tetraiodo‐p‐benzoquinone anion radicals (I4Q−.) and iodide anions, was observed and characterized for the first time. X‐ray structural and EPR/UV–Vis spectral studies revealed that the anion–anion bonding led to the formation of crystals comprising 2D layers of I4Q−. anion radicals linked by iodides and separated by Et4N+ counter‐ions. Computational analysis suggested that the seemingly antielectrostatic halogen bonds in these systems were formed via a combination of several factors. First, an attenuation of the interionic repulsion by the solvent facilitated close approach of the anions leading to their mutual polarization. This resulted in the appearance of positively charged areas (σ‐holes) on the surface of the iodine substituents in I4Q−. responsible for the attractive interaction. Finally, the solid‐state associations were also stabilized by multicenter (4:4) halogen bonding between I4Q−. and iodide.
Stringing the Perylene Diimide Bow
Authors: Liu Taifeng , Yang Jingjing , Geyer Florian , Conrad‐Burton Felisa S. , Hernández Sánchez Raúl , Li Hexing , Zhu Xiaoyang , Nuckolls Colin P. , Steigerwald Michael L. , Xiao Shengxiong
Published: June 2020

This study explores a new mode of contortion in perylene diimides where the molecule is bent, like a bow, along its long axis. These bowed PDIs were synthesized through a facile fourfold Suzuki macrocyclization with aromatic linkers and a tetraborylated perylene diimide that introduces strain and results in a bowed structure. By altering the strings of the bow, the degree of bending can be controlled from flat to highly bent. Through spectroscopy and quantum chemical calculations, it is demonstrated that the energy of the lowest unoccupied orbital can be controlled by the degree of bending in the structures and that the energy of the highest occupied orbital can be controlled to a large extent by the constitution of the aromatic linkers. The important finding is that the bowing results not only in red‐shifted absorptions but also more facile reductions.
Polyesters by a Radical Pathway: Rationalization of the Cyclic Ketene Acetal Efficiency
Authors: Tardy Antoine , Gil Noémie , Plummer Christopher M. , Siri Didier , Gigmes Didier , Lefay Catherine , Guillaneuf Yohann
Published: June 2020

Radical ring‐opening polymerization (rROP) of cyclic ketene acetals (CKAs) combines the advantages of both ring‐opening polymerization and radical polymerization thereby allowing the robust production of polyesters coupled with the mild polymerization conditions of a radical process. rROP was recently rejuvenated by the possibility to copolymerize CKAs with classic vinyl monomers leading to the insertion of cleavable functionality into a vinyl‐based copolymer backbone and thus imparting (bio)degradability. Such materials are suitable for a large scope of applications, particularly within the biomedical field. The competition between the ring‐opening and ring‐retaining propagation routes is a major complication in the development of efficient CKA monomers, ultimately leading to the use of only four monomers that are known to completely ring‐open under all experimental conditions. In this article we investigate the radical ring‐opening polymerization of model CKA monomers and demonstrate by the combination of DFT calculations and kinetic modeling using PREDICI software that we are now able to predict in silico the ring‐opening ability of CKA monomers.
Zinc–Organic Battery with a Wide Operation‐Temperature Window from −70 to 150 °C
Authors: Wang Nan , Dong Xiaoli , Wang Bingliang , Guo Zhaowei , Wang Zhuo , Wang Renhe , Qiu Xuan , Wang Yonggang
Published: June 2020

Aqueous zinc (Zn) batteries have been considered as promising candidates for grid‐scale energy storage. However, their cycle stability is generally limited by the structure collapse of cathode materials and dendrite formation coupled with undesired hydrogen evolution on the Zn anode. Herein we propose a zinc–organic battery with a phenanthrenequinone macrocyclic trimer (PQ‐MCT) cathode, a zinc‐foil anode, and a non‐aqueous electrolyte of a N,N‐dimethylformamide (DMF) solution containing Zn2+. The non‐aqueous nature of the system and the formation of a Zn2+–DMF complex can efficiently eliminate undesired hydrogen evolution and dendrite growth on the Zn anode, respectively. Furthermore, the organic cathode can store Zn2+ ions through a reversible coordination reaction with fast kinetics. Therefore, this battery can be cycled 20 000 times with negligible capacity fading. Surprisingly, this battery can even be operated in a wide temperature range from −70 to 150 °C.
Copper‐Catalyzed Deaminative Difluoromethylation
Authors: Zeng Xiaojun , Yan Wenhao , Zacate Samson B. , Cai Aijie , Wang Yufei , Yang Dongqi , Yang Kundi , Liu Wei
Published: June 2020

The difluoromethyl group (CF2H) is considered to be a lipophilic and metabolically stable bioisostere of an amino (NH2) group. Therefore, methods that can rapidly convert an NH2 group into a CF2H group would be of great value to medicinal chemistry. We report herein an efficient Cu‐catalyzed approach for the conversion of alkyl pyridinium salts, which can be readily synthesized from the corresponding alkyl amines, to their alkyl difluoromethane analogues. This method tolerates a broad range of functional groups and can be applied to the late‐stage modification of complex amino‐containing pharmaceuticals.
Phenalenannulations: Three‐Point Double Annulation Reactions that Convert Benzenes into Pyrenes
Authors: Kawade Rahul Kisan , Hu Chaowei , Dos Santos Nikolas R. , Watson Noelle , Lin Xinsong , Hanson Kenneth , Alabugin Igor V.
Published: June 2020

3‐Point annulations, or phenalenannulations, transform a benzene ring directly into a substituted pyrene by “wrapping” two new cycles around the perimeter of the central ring at three consecutive carbon atoms. This efficient, modular, and general method for π‐extension opens access to non‐symmetric pyrenes and their expanded analogues. Potentially, this approach can convert any aromatic ring bearing a ‐CH2Br or a ‐CHO group into a pyrene moiety. Depending upon the workup choices, the process can be directed towards either tin‐ or iodo‐substituted product formation, giving complementary choices for further various cross‐coupling reactions. The two‐directional bis‐double annulation adds two new polyaromatic extensions with a total of six new aromatic rings at a central core.
Irreversible Amide‐Linked Covalent Organic Framework for Selective and Ultrafast Gold Recovery
Authors: Qian Hai‐Long , Meng Fan‐Lin , Yang Cheng‐Xiong , Yan Xiu‐Ping
Published: June 2020

Design of stable adsorbents for selective gold recovery with large capacity and fast adsorption kinetics is of great challenge, but significant for the economy and the environment. Herein, we show the design and preparation of an irreversible amide‐linked covalent organic framework (COF) JNU‐1 via a building block exchange strategy for efficient recovery of gold. JNU‐1 was synthesized through the exchange of 4,4′‐biphenyldicarboxaldehyde (BA) in mother COF TzBA consisting of 4,4′,4′′‐(1,3,5‐triazine‐2,4,6‐triyl)trianiline (Tz) and BA with terephthaloyl chloride. The irreversible amide linked JNU‐1 gave good stability, unprecedented fast kinetics, excellent selectivity and outstanding adsorption capacity for gold recovery. X‐ray photoelectron spectroscopy along with thermodynamic study and quantum mechanics calculation reveals that the excellent performance of JNU‐1 for gold recovery results from the formation of hydrogen bonds C(N)−H⋅⋅⋅Cl and coordinate interaction of O and Au. The rational design of irreversible bonds as both inherent linkage and functional groups in COFs is a promising way to prepare stable COFs for diverse applications.
Sulfur‐Modified Oxygen Vacancies in Iron–Cobalt Oxide Nanosheets: Enabling Extremely High Activity of the Oxygen Evolution Reaction to Achieve the Industrial Water Splitting Benchmark
Authors: Zhuang Linzhou , Jia Yi , Liu Hongli , Li Zhiheng , Li Mengran , Zhang Longzhou , Wang Xin , Yang Dongjiang , Zhu Zhonghua , Yao Xiangdong
Published: June 2020

The oxygen vacancies of defective iron–cobalt oxide (FeCoOx‐Vo) nanosheets are modified by the homogeneously distributed sulfur (S) atoms. S atoms can not only effectively stabilize oxygen vacancies (Vo), but also form the Co−S coordination with Co active site in the Vo, which can modulate the electronic structure of the active site, enabling FeCoOx‐Vo‐S to exhibit much superior OER activity. FeCoOx‐Vo‐S exhibits a mass activity of 2440.0 A g−1 at 1.5 V vs. RHE in 1.0 m KOH, 25.4 times higher than that of RuO2. The Tafel slope is as low as 21.0 mV dec−1, indicative of its excellent charge transfer rate. When FeCoOx‐Vo‐S (anode catalyst) is paired with the defective CoP3/Ni2P (cathode catalyst) for overall water splitting, current densities of as high as 249.0 mA cm−2 and 406.0 mA cm−2 at a cell voltage of 2.0 V and 2.3 V, respectively, can be achieved.
A Simple Strategy to Eliminate Hexosylation Bias in the Relative Quantification of N‐Glycosylation in Biopharmaceuticals
Authors: Esser‐Skala Wolfgang , Wohlschlager Therese , Regl Christof , Huber Christian G.
Published: June 2020

N‐glycosylation may affect the safety and efficacy of biopharmaceuticals and is thus monitored during manufacturing. Mass spectrometry of the intact protein is increasingly used to reveal co‐existing glycosylation variants. However, quantification of N‐glycoforms via this approach may be biased by single hexose residues as introduced by glycation or O‐glycosylation. Herein, we describe a simple strategy to reveal actual N‐glycoform abundances of therapeutic antibodies, involving experimental determination of glycation levels followed by computational elimination of the “hexosylation bias”. We show that actual N‐glycoform abundances may significantly deviate from initially determined values. Indeed, glycation may even obscure considerable differences in N‐glycosylation patterns of drug product batches. Our observations may thus have implications for biopharmaceutical quality control. Moreover, we solve an instance of the problem of isobaricity, which is fundamental to mass spectrometry.
In Situ Scanning Tunneling Microscopy of Cobalt‐Phthalocyanine‐Catalyzed CO2 Reduction Reaction
Authors: Wang Xiang , Cai Zhen‐Feng , Wang Yu‐Qi , Feng Ya‐Chen , Yan Hui‐Juan , Wang Dong , Wan Li‐Jun
Published: June 2020

We report a molecular investigation of a cobalt phthalocyanine (CoPc)‐catalyzed CO2 reduction reaction by electrochemical scanning tunneling microscopy (ECSTM). An ordered adlayer of CoPc was prepared on Au(111). Approximately 14 % of the adsorbed species appeared with high contrast in a CO2‐purged electrolyte environment. The ECSTM experiments indicate the proportion of high‐contrast species correlated with the reduction of CoIIPc (−0.2 V vs. saturated calomel electrode (SCE)). The high‐contrast species is ascribed to the CoPc‐CO2 complex, which is further confirmed by theoretical simulation. The sharp contrast change from CoPc‐CO2 to CoPc is revealed by in situ ECSTM characterization of the reaction. Potential step experiments provide dynamic information for the initial stage of the reaction, which include the reduction of CoPc and the binding of CO2, and the latter is the rate‐limiting step. The rate constant of the formation and dissociation of CoPc‐CO2 is estimated on the basis of the in situ ECSTM experiment.
Heterostructured Inter‐Doped Ruthenium–Cobalt Oxide Hollow Nanosheet Arrays for Highly Efficient Overall Water Splitting
Authors: Wang Cheng , Qi Limin
Published: June 2020

The development of transition‐metal‐oxides (TMOs)‐based bifunctional catalysts toward efficient overall water splitting through delicate control of composition and structure is a challenging task. Herein, the rational design and controllable fabrication of unique heterostructured inter‐doped ruthenium–cobalt oxide [(Ru–Co)Ox] hollow nanosheet arrays on carbon cloth is reported. Benefiting from the desirable compositional and structural advantages of more exposed active sites, optimized electronic structure, and interfacial synergy effect, the (Ru–Co)Ox nanoarrays exhibited outstanding performance as a bifunctional catalyst. Particularly, the catalyst showed a remarkable hydrogen evolution reaction (HER) activity with an overpotential of 44.1 mV at 10 mA cm−2 and a small Tafel slope of 23.5 mV dec−1, as well as an excellent oxygen evolution reaction (OER) activity with an overpotential of 171.2 mV at 10 mA cm−2. As a result, a very low cell voltage of 1.488 V was needed at 10 mA cm−2 for alkaline overall water splitting.
Unexpected Acetylation of Endogenous Aliphatic Amines by Arylamine N‐Acetyltransferase NAT2
Authors: Conway Louis P. , Rendo Veronica , Correia Mário S. P. , Bergdahl Ingvar A. , Sjöblom Tobias , Globisch Daniel
Published: June 2020

N‐Acetyltransferases play critical roles in the deactivation and clearance of xenobiotics, including clinical drugs. NAT2 has been classified as an arylamine N‐acetyltransferase that mainly converts aromatic amines, hydroxylamines, and hydrazines. Herein, we demonstrate that the human arylamine N‐acetyltransferase NAT2 also acetylates aliphatic endogenous amines. Metabolomic analysis and chemical synthesis revealed increased intracellular concentrations of mono‐ and diacetylated spermidine in human cell lines expressing the rapid compared to the slow acetylator NAT2 phenotype. The regioselective N8‐acetylation of monoacetylated spermidine by NAT2 answers the long‐standing question of the source of diacetylspermidine. We also identified selective acetylation of structurally diverse alkylamine‐containing drugs by NAT2, which may contribute to variations in patient responses. The results demonstrate a previously unknown functionality and potential regulatory role for NAT2, and we suggest that this enzyme should be considered for re‐classification.
Quantitative Supramolecular Heterodimerization for Efficient Energy Transfer
Authors: Wu Guanglu , Huang Zehuan , Scherman Oren A.
Published: June 2020

The challenge of quantitatively forming self‐assembled heterodimers without other equilibrium by‐products is overcome through self‐sorting favored by the introduction of designed shape‐complementary moieties. Such a supramolecular strategy based on cucurbit[8]uril‐directed dimerization is further applied to generate hetero‐chromophore dimers quantitatively, leading to efficient energy transfer (>85 %) upon photoexcitation.
Ørsted and Bunsen: Voltaic Batteries, Electric Arcs, Electromagnetism, and Electrolysis
Authors: Wentrup Curt
Published: June 2020

200 years ago Ørsted laid the foundation of electromagnetism in his famous experiment in which a magnetic needle is deflected in the electrical field of a platinum wire. For this he used his own Cu‐Zn trough battery, which was among the best then available, but 21 years later it was surpassed by the coal‐zinc battery invented by Bunsen, which became highly successful and acclaimed. That year, 1841, Bunsen made his first direct contact with Scandinavia when he visited Berzelius in Stockholm, Palmstedt in Gothenburg, and Ørsted, Scharling, and Zeise in Copenhagen. Like almost everybody in continental Europe, they adopted Bunsen's battery, and Ørsted used it for his experiments with a very large electromagnet. The paths of Ørsted's and Bunsen's research crossed again much later through the synthesis of elemental aluminum, which was first achieved by Ørsted in 1825 (although it was probably not obtained as the pure metal) and performed quite differently by Bunsen, by electrolysis using his coal‐zinc battery, in 1854.
o‐Trityl phenoxy‐imino vanadium (III) complexes: synthesis, characterization, and catalysis on ethylene (co)polymerization
Authors: Hao Zhiqiang , Li Feng , Gao Wei
Published: June 2020

Several phenoxy‐imine ligands bearing o‐trityl group in phenoxy moiety RN=CHArOH (Ar = C6H2(CPh3)tBu, R = 2,6‐Me2C6H3 (L1H); 2,6‐iPr2C6H3 (L2H); 3,5‐(CF3)2C6H3 (L3H); 3,5‐(OMe)2C6H3 (L4H); CHPh2 (L5H); CPh3 (L6H)) were synthesized and characterized by1H NMR and 13C NMR spectroscopy. The vanadium complexes based on these ligands LVCl2(THF)2 (1–6) were synthesized via conventional transmetalation reaction in moderate to high yields. Complexes 1–6 were fully characterized by FT‐IR, elemental analyses and the molecular structures of 1, 2·H2O, (2·H2O)2(μ‐Cl)2, 4, and 5 were confirmed by X‐ray crystallographic analysis in which the six‐coordinated vanadium centers are in a typical octahedral geometry. Upon activation with Et2AlCl in toluene, complexes 1–6 showed high activities in ethylene polymerization affording polymers with moderate molecular weight (5.9–11.8 × 104 Da). Moreover, in hexane or CH2Cl2, 1–6/Et2AlCl exhibited enhanced activities. When activated with MAO or MMAO in toluene, these complexes showed relatively low activities but afforded polymers with ultra‐high molecular weight (up to 3.30 × 106 Da). 1–6/Et2AlCl also showed high activities in ethylene/1‐hexene copolymerization at room temperature giving moderate molecular‐weight polymers (6.5–11.4 × 104 Da) with co‐monomer incorporation being of 6.0 ~ 7.8%.
Cavitand‐Based Pd‐Pyridyl Coordination Capsules: Guest‐Induced Homo‐ or Heterocapsule Selection and Applications of Homocapsules to the Protection of a Photosensitive Guest and Chiral Capsule Formation
Authors: Nakamura Munechika , Tsukamoto Yoshimi , Ueta Takuro , Sei Yoshihisa , Fukushima Takanori , Yoza Kenji , Kobayashi Kenji
Published: June 2020

A 2 : 4 mixture of tetrakis[4‐(4‐pyridyl)phenyl]cavitand (1) or tetrakis[4‐(4‐pyridyl)phenylethynyl]cavitand (2) and Pd(dppp)(OTf)2 self‐assembles into a homocapsule {12 ⋅ [Pd(dppp)]4}8+ ⋅ (TfO−)8 (C1) or {22 ⋅ [Pd(dppp)]4}8+ ⋅ (TfO−)8 (C2), respectively, through Pd−Npy coordination bonds. A 1 : 1 : 4 mixture of 1, 2, and Pd(dppp)(OTf)2 produced a mixture of homocapsules C1, C2, and a heterocapsule {1 ⋅ 2 ⋅ [Pd(dppp)]4}8+ ⋅ (TfO−)8 (C3) in a 1 : 1 : 0.98 mole ratio. Selective formation (self‐sorting) of homocapsules C1 and C2 or heterocapsule C3 was controlled by guest‐induced encapsulation under thermodynamic control. Applications of Pd−Npy coordination capsules with the use of 1 were demonstrated. Capsule C1 serves as a guard nanocontainer for trans‐4,4′‐diacetoxyazobenzene to protect against the trans‐to‐cis photoisomerization by encapsulation. A chiral capsule {12 ⋅ [Pd((R)‐BINAP)]4}8+ ⋅ (TfO−)8 (C5) was also constructed. Capsule C5 induces supramolecular chirality with respect to prochiral 2,2′‐bis(alkoxycarbonyl)‐4,4′‐bis(1‐propynyl)biphenyls by diastereomeric encapsulation through the asymmetric suppression of rotation around the axis of the prochiral biphenyl moiety.
Biological properties and structural characterization of a novel rhamnolipid like‐biosurfactants produced by Lactobacillus casei subsp. casei TM1B
Authors: Mouafo Hippolyte T. , Mbawala Augustin , Somashekar Devappa , Tchougang Hervé M. , Harohally Nanishankar V. , Ndjouenkeu Robert
Published: June 2020

Biosurfactants are microbial surface‐active compounds with antimicrobial and antioxidant activities that display a range of physiological functions. In this study, a strain isolated from a Cameroonian fermented milk “pendidam” and identified as Lactobacillus casei subsp. casei TM1B was used for biosurfactants production. The biosurfactants produced by L. casei TM1B with molasses as the substrate had a good surface (40.77 mN/m) and emulsifying (84.50%) activities. The scavenging of the ABTS+• radical (IC50 value of 0.60 ± 0.03 mg/mL) by the biosurfactants was found to be higher than that of DPPH• radical (IC50 value of 0.97 ± 0.13 mg/mL). The maximum chelating activity of biosurfactants (82.29%) was observed at 3.5 mg/mL. The biologically active compound of the biosurfactants produced by L. casei TM1B was identified as 2,5‐O‐methylrhamnofuranosyl‐palmitate, a novel rhamnolipid‐like biosurfactant by using chemical, Fourier transform infrared spectroscopy, gas chromatography‐mass spectrometry, and NMR analysis. The biosurfactants were bactericidal against several Gram‐negative and Gram‐positive pathogens (minimum inhibitory concentration values ranged from 3.22 to 12.83 mg/mL), and scanning electron microscope analysis revealed bacterial cell walls and membranes as main targets.
Effectiveness of Pulsed Electromagnetic Fields on Bone Healing: A Systematic Review and Meta‐Analysis of Randomized Controlled Trials
Authors: Peng Lihong , Fu Chenying , Xiong Feng , Zhang Qing , Liang Zejun , Chen Li , He Chengqi , Wei Quan
Published: June 2020

The effect of pulsed electromagnetic field (PEMF) on bone healing is still uncertain and it has not been established as a standardized treatment. The aim of this systematic review and meta‐analysis is to evaluate the effect of PEMF on bone healing in patients with fracture. We searched CNKI, Wan Fang, VIP, EMbase, PubMed, CENTRAL, Web of Science, Physiotherapy Evidence Database, and Open Grey websites for randomized controlled trials (published before July 2019 in English or Chinese) comparing any form of PEMF to sham. Reference lists were also searched. Related data were extracted by two investigators independently. The bias risk of the articles and the evidence strength of the outcomes were evaluated. Twenty‐two studies were eligible and included in our analysis (n = 1,468 participants). The pooled results of 14 studies (n = 1,131 participants) demonstrated that healing rate in PEMF group was 79.7% (443/556), and that in the control group was 64.3% (370/575). PEMF increased healing rate (RR = 1.22; 95% confidence interval [CI] = 1.10–1.35; I2 = 48%) by the Mantel–Haenszel analysis, relieved pain (standardized mean difference (SMD) = −0.49; 95% CI = −0.88 to −0.10; I2 = 60%) by the inverse variance analysis, and accelerated healing time (SMD = −1.01; 95% CI = −2.01 to −0.00; I2 = 90%) by the inverse variance analysis. Moderate quality evidence suggested that PEMF increased healing rate and relieved pain of fracture, and very low‐quality evidence showed that PEMF accelerated healing time. Larger and higher quality randomized controlled trials and pre‐clinical studies of optimal frequency, amplitude, and duration parameters are needed. © 2020 Bioelectromagnetics Society.