bluuebunny/crossref_metadata_2025 huggingface dataset:
Dopamine Semiquinone Radical Doped PEDOT:PSS: Enhanced Conductivity, Work Function and Performance in Organic Solar Cells
Authors: Zeng Miao , Wang Xiaojing , Ma Ruijie , Zhu Weiya , Li Yuan , Chen Zhongxin , Zhou Jiawen , Li Wenqiang , Liu Tao , He Zhicai , Yan He , Huang Fei , Cao Yong
Published: May 2020

Poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has been is applied as hole transport material in organic electronic devices for more than 20 years. However, the redundant sulfonic acid group of PEDOT:PSS has often been overlooked. Herein, PEDOT:PSS‐DA is prepared via a facile doping of PEDOT:PSS with dopamine hydrochloride (DA·HCl) which reacts with the redundant sulfonic acid of PSS. The PEDOT:PSS‐DA film exhibits enhanced work function and conductivity compared to those of PEDOT:PSS. PEDOT:PSS‐DA‐based devices show a power conversion efficiency of 16.55% which is the highest in organic solar cells (OSCs) with (poly[(2,6‐(4,8‐bis(5‐(2‐ethylhexyl)‐4‐fluorothiophen‐2‐yl)benzo[1,2‐b:4,5‐b′]dithio‐phene))‐co‐(1,3‐di(5‐thiophene‐2‐yl)‐5,7‐bis(2‐ethylhexyl)‐benzo[1,2‐c:4,5‐c′]dithiophene‐4,8‐dione))] (PM6):(2,2′‐((2Z,2′Z)‐((12,13‐bis(2‐ethylhexyl)‐3,9‐diundecyl‐12,13‐dihydro‐[1,2,5]thiadiazolo[3,4‐e]thieno[2′′,3′:4′,5′]thieno[2′,3′:4,5]pyrrolo[3,2‐g]thieno[2′,3′:4,5]thieno[3,2‐b]indole‐2,10‐diyl)bis(methanylylidene))bis(5,6‐difluoro‐3‐oxo‐2,3‐dihydro‐1H‐indene‐2,1‐diylidene))dimalononitrile) (Y6) as the active layer. Furthermore, PEDOT:PSS‐DA also exhibits enhanced performance in three other donor/acceptor systems, exhibiting high compatibility in OSCs. This work demonstrates that doping PEDOT:PSS with various amino derivatives is a potentially efficient strategy to enhance the performance of PEDOT:PSS in organic electronic devices.
Spontaneous Atomic Ruthenium Doping in Mo2CTX MXene Defects Enhances Electrocatalytic Activity for the Nitrogen Reduction Reaction
Authors: Peng Wei , Luo Min , Xu Xiandong , Jiang Kang , Peng Ming , Chen Dechao , Chan Ting‐Shan , Tan Yongwen
Published: May 2020

The electrochemical nitrogen reduction reaction (NRR) process usually suffers extremely low Faradaic efficiency and ammonia yields due to sluggish NN dissociation. Herein, single‐atomic ruthenium modified Mo2CTX MXene nanosheets as an efficient electrocatalyst for nitrogen fixation at ambient conditions are reported. The catalyst achieves a Faradaic efficiency of 25.77% and ammonia yield rate of 40.57 µg h−1 mg−1 at ‐0.3 V versus the reversible hydrogen electrode in 0.5 m K2SO4 solution. Operando X‐ray absorption spectroscopy studies and density functional theory calculations reveal that single‐atomic Ru anchored on MXene nanosheets act as important electron back‐donation centers for N2 activation, which can not only promote nitrogen adsorption and activation behavior of the catalyst, but also lower the thermodynamic energy barrier of the first hydrogenation step. This work opens up a promising avenue to manipulate catalytic performance of electrocatalysts utilizing an atomic‐level engineering strategy.
Ultrasound‐assisted enhanced and rapid uptake of anionic dyes from the binary system onto MnFe2O4/polyaniline nanocomposite at neutral pH
Authors: Das Payel , Debnath Animesh , Saha Biswajit
Published: May 2020

Remediation of toxic dyes from an aqua matrix using novel nanocomposites as adsorbent is an attractive yet challenging task, especially when the adsorption process needs to be operated at near‐neutral solution pH. Recently, conducting polymer‐based novel nanocomposites have been studied widely for environmental remediation because of their high distinctive surface area, mesoporous nature, easy synthesis process, availability of the low‐cost monomer, and comprehensive range of functionality. This research deals with the fabrication and application of manganese ferrite and polyaniline nanocomposite (MnF‐PANI‐NC) for the ultrasound‐assisted adsorption of methyl red (MR) and congo red (CR) dye from binary dye solution at neutral pH. The X‐ray diffraction pattern of MnF‐PANI‐NC confirmed the successful impregnation of manganese ferrite onto polyaniline, and the field emission gun scanning electron microscopy and transmission electron microscopy images revealed the nanoscale formation of this composite. The saturation magnetization of ~20 emu/g endorses the easy magnetic separation of MnF‐PANI‐NC from dye solution. MnF‐PANI‐NC has revealed higher adsorptive affinity towards MR and CR dye concerning pure PANI and pure MnF nanoparticles at near‐neutral solution pH. Assimilation of ultrasound wavse in this adsorption procedure improved the mass transfer rate significantly, and within 6 min of reaction more than 95% of MR and CR dye removal was achieved. Ultrasound waves also enhanced the equilibrium dye uptake efficiency (more than 95%) of MnF‐PANI‐NC compared to the adsorption reaction by overhead stirring (40–50%) and shaking (40–60%) for both MR and CR dyes. Kinetic modeling of the experimental data revealed accurate fitting of the pseudo‐second‐order model in association with intraparticle diffusion. Binary dye adsorption onto MnF‐PANI‐NC obeyed the Langmuir isotherm model accurately, and maximum adsorption capacities of 294.12 and 317.46 mg/g were observed for MR and CR dyes, respectively.
Synthesis of Pd@graphene oxide framework nanocatalyst with enhanced activity in Heck‐Mizoroki cross‐coupling reaction
Authors: Shekarizadeh Arezoo , Azadi Roya
Published: May 2020

A new method was developed for producing a catalyst involving a Pd nanoparticle (NP) embedded in a graphene oxide framework (Pd@GOF) with ordered macro‐ and mesoporous structures. First, 5,5′‐diamino‐2,2′‐bipyridine was selected as cross‐linking for covalent modification of GO nanosheets to prepare a three‐dimensional (3D) framework with interlayer spaces in which well‐dispersed and ultra‐small Pd NPs in situ grew and embedded the framework. The synthesized nanopores 3D Pd@GOF can act as nanoreactors to help the reaction substrates thoroughly come into contact with the surface of Pd NPs, thereby exhibiting high activity toward the Heck reaction, rarely reported concerning Pd NPs supported on one‐side functionalized graphene. The Pd@GOF catalyst can be used 10 times without any significant loss in the catalytic activity, confirming the long‐term stability of this catalyst. Therefore, the covalently assembled GOF was proposed as a universal platform for hosting noble metal NPs to construct the desired metal@GOF nanocatalyst with improved activity and stability that can be used in a broad range of practical applications.
Synthesis of3,13‐diglycidyloxypropyloctaphenyldouble‐decker polyhedral oligomeric silsesquioxane and the thermal reaction properties with thermosetting phenol‐formaldehyde resin
Authors: Niu Zhaoqi , Tian Dan , Yan Long , Ma Xiaoyan , Zhang Chengshuang , Hou Xiao
Published: May 2020

3,13‐Diglycidyloxypropyloctaphenyl double‐decker silsesquioxane (EP‐DDSQ) was synthesized by process of alkaline hydrolysis condensation of phenyltrimethoxysilane and corner capping reaction of methyldichlorosilane, followed by hydrosilylation with allyl glycidyl ether, and the resultant structure was confirmed by fourier transform infrared spectrometer (FTIR) and nuclear magnetic resonance (NMR), respectively. The thermosetting phenol‐formaldehyde (PF) resin was then modified by EP‐DDSQ, and the reactivity of PF resin with EP‐DDSQ and thermal pyrolysis of modified cured resin were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The surface morphologies of modified resins at high temperature were characterized with field emission scanning electron microscope (FESEM), and chemical structure of modified resins was analyzed through X‐ray photoelectron spectrometer (XPS). The results showed that the appropriate addition of EP‐DDSQ did not affect the curing temperature of the PF resin itself, but could improve the heat resistance of the system. When the amount of EP‐DDSQ added was 10%, the initial degradation temperature of PF resin was increased by 49.31°C, and when the amount of EP‐DDSQ added was 16%, the char yield of which was reached up to 61.39%, compared with that of pure PF resin (TGA1,000°Cof 57.62%) at Ar atmosphere. More importantly, the modified resin formed a regular and dense layer of SiC and SiOxceramic on the surface after ablation in the muffle furnace at 800°C air atmosphere, which is very important for ablative resistant materials.
Blue Light‐promoted Carbene Transfer Reactions of Tosylhydrazones
Authors: Xu Yingying , Lv Guanghui , Yan Kaichuan , He Hua , Li Jianglian , Luo Yi , Lai Ruizhi , Hai Li , Wu Yong
Published: May 2020

Metal‐free photochemical carbene‐transfer reactions of tosylhydrazones were developed under blue light irradiation at room temperature. This reaction constructs C−X (X=C, N, O, S) bonds and cyclopropanes from readily available and stable starting materials.
Pedagogical devices as children’s social care levers: A study of social care workers’ attitudes towards boarding schools to care for and educate children in need
Authors: Murphy David , Oliver Mary , Pourhabib Sanam , Adkins Michael , Hodgen Jeremy
Published: May 2020

It has been proposed that boarding schools in England can be used to provide a stable education and care environment for vulnerable children in need, and the government is expanding their use. However, for vulnerable children to be placed in boarding schools, social workers will need to be willing to contemplate boarding as a viable care option. In this study we interviewed N = 21 social care practitioners including directors, senior and middle managers, frontline social workers, social worker‐academics and family support workers who work with vulnerable children. Using thematic analysis of the transcribed interviews, seven major themes identified a range of issues and concerns held by social care workers about placing vulnerable children in boarding schools. We present these themes and consider the issues that will have to be addressed prior to changes in policy and practice. The study concludes that many of those within the social work profession are unlikely to consider boarding as an intervention for children in need. Further research in this area is a matter of urgency.
A rapid HPLC–MS/MS method for determining busulfan in hemolytic samples from children with hematopoietic stem cell transplantation
Authors: Jinjie Yuan , Sun Ning , Zhang Shuyu , Feng Xinying , Chen Xijing , Zhao Di , Zhao Libo
Published: May 2020

A rapid and sensitive method for the quantitative detection of busulfan (BU) in children's hemolytic samples by HPLC–tandem mass spectrometry (MS/MS) was established. In this study, the sample preparation procedure involved a one‐step protein precipitation with acetonitrile (ACN) solution, and the HPLC–MS/MS method used Hypersil GOLD C18. The mobile phase consisted of 10 mM ammonium acetate solution (containing 0.1% formic acid) and ACN with a flow rate of 0.4 mL/min. Multiple reaction monitoring modes were used for quantitative analysis and the ion pairs of BU and BU‐d8 were m/z 263.9 → 150.9 and 272.0 → 159.0, respectively. BU had a good linearity in the range of 0.01–10 μg mL−1. The intra‐ and inter‐day relative error was between –7.21% and 8.26%, and the coefficient of variation was less than 12.64%. The average extraction recovery rate in plasma samples was 99.76% ± 6.53%, and the matrix in normal plasma and hemolyzed plasma had no significant effect on the detection results. Normal and hemolytic samples could maintain good stability at 4, 25 and –40°C. As a result, this method is particularly suitable for determining BU in hemolytic samples from children with hematopoietic stem cell transplantation (HSCT), and this study provides the methodological basis for further research on the pharmacokinetics of BU in children with HSCT.
Rapid and cost‐effective LC–MS/MS method for determination of hydroxycitric acid in plasma: Application in the determination of pharmacokinetics in commercial Garcinia preparations
Authors: Bhutani Priyadeep , U. Rekha , H. N. Shivakumar , Ranjanna Prabhakar K. , Paul Atish T.
Published: May 2020

Garcinia cambogia is one of the most commonly used anti‐obesity dietary supplements, and hydroxycitric acid (HCA) is a major constituent in the commercial preparations of Garcinia. High doses of HCA are often consumed without much awareness of its pharmacokinetic and toxicokinetic parameters, and therefore, a complete understanding of its effects is lacking. The first step in understanding these parameters is the availability of a reliable bioanalytical method. Here, we present the first report on a UPLC–MS/MS method for analysis of HCA in rat plasma after a simplified and cost‐effective protein precipitation. Chromatographic separation of the analytes in the supernatant was achieved using hydrophilic interaction liquid chromatography, where mass parameters were optimized and a rapid 5‐min quantitative assay was developed. The method was highly sensitive, accurate, precise and linear in the concentration range of 10.5–5000 ng/mL (validated according to the United States Food and Drug Administration guidelines). Further, the method was successfully used to describe the pharmacokinetic profile of HCA in rat plasma after the administration of pure HCA and commercial Garcinia preparations.
The μ‐opioid receptor gene A118G polymorphism is associated with insecure attachment in children with disruptive mood regulation disorder and their mothers
Authors: Cimino Silvia , Carola Valeria , Cerniglia Luca , Bussone Silvia , Bevilacqua Arturo , Tambelli Renata
Published: May 2020

Background

The A118G single nucleotide polymorphism (SNP) of the μ‐opioid receptor gene, with high expression of the A allele and low expression of the G allele, has been associated with emotional/behavioral dysregulation and depressive disorders and is recognized as a mediator of affiliative behavior. No study has thus far investigated this SNP in school‐age children with disruptive mood regulation disorder (DMDD). This study compared a sample of healthy children and their mothers with a sample of children with DMDD and their mothers, evaluating whether insecure attachment and psychopathological symptoms are associated with A allele‐ or G allele‐carrying mothers and children and whether caregiving capacities are associated with A allele‐ or G allele‐carrying mothers.

Methods

For evaluation of their psychopathological symptoms and attachment styles, mothers filled out the CBCL/6‐18, the SCL‐90‐R, and the ECR. To evaluate the types of relationship children were experiencing with their mothers, children filled out the ECR‐revised child version and the PBI. Genotypic analyses were conducted on DNA samples obtained by buccal swabbing from children and mothers.

Results

An insecure attachment style was more frequent in mothers and children carrying the G allele (G/G + A/G genotypes). In the clinical sample, G allele‐carrying children scored higher than homozygous A/A ones on the subscales of Withdrawal and Conduct Problems. G‐carrying mothers showed higher interpersonal sensitivity, depression, hostility, and paranoid ideation and provided less care than A/A mothers.

Conclusions

This study offers new insights into the associations between the A118G SNP of the μ‐opioid receptor gene and emotional/behavioral functioning, attachment style in children, and psychopathology and caregiving ability in mothers.
Body donation in Italy: Lights and shadows of law No. 10/2020
Authors: Boscolo‐Berto Rafael , Porzionato Andrea , Stecco Carla , Macchi Veronica , De Caro Raffaele
Published: May 2020

Introduction

Recently, law No. 10 of February 10, 2020, entitled “Rules regarding the disposition of one's body and post‐mortem tissues for study, training, and scientific research purposes” was introduced in Italy. Although its provisions respond to a constructive subject, some practical issues are evident in the approved text.

Materials and Methods

A systematic review of the literature was performed by searching online medical and juridical databases to identify publications and Italian law provisions related to body donation programs.

Results

The updated regulatory framework was outlined and compared to that in force previously, and the following features are discussed: (a) matter of law; (b) donors' information and consent; (c) reference centers and funding, and (d) procedural regulatory details. Several critical issues were detected in the approved wording with respect to teaching/training recipients, the role of university anatomy institutes, family members' exclusion from participating in the donation process in any capacity, the duration of donation, the management of corpses, partial donations, and the compatibility with organ donation. Suggestions are provided to overcome certain operational limitations in implementing the regulation, which is still being drafted to date.

Conclusions

This article shares with the international scientific community the principles and controversies underlying a regulatory innovation introduced in Italy to allow legislative amendments to inadequate provisions of body donation, as well as draw the attention of the entire anatomic community to critical issues if other countries undertake the same legislative reform.
Isolation and Identification of Three New Sterigmatocystin Derivatives from the Fungus Aspergillus versicolor Guided by Molecular Networking Approach
Authors: Han Xiao , Tang Xuli , Luo Xiangchao , Sun Caixia , Liu Kechun , Zhang Yun , Li Pinglin , Li Guoqiang
Published: May 2020

Molecular networking approach was applied for the targeted isolation of new sterigmatocystin derivatives, sterigmatocystins A–C, from the marine sponge‐derived fungus Aspergillus versicolor. Sterigmatocystin A features a rare 6/6/6/6/5 polycyclic system. The structures of sterigmatocystins A–C, including absolute configurations, were determined on the basis of spectroscopic data and ECD calculations. Sterigmatocystin A showed more stronger promoting angiogenesis activity than the positive control at 1.25 μM level in transgenic fluorescent zebrafish. Sterigmatocystins A–C also exhibited moderate antiviral activity by the inhibition of HSV‐2.
DMBT1 suppresses cell proliferation, migration and invasion in ovarian cancer and enhances sensitivity to cisplatin through galectin‐3/PI3k/Akt pathway
Authors: Ma Nan , Zhao Yuqing
Published: May 2020

Ovarian cancer (OC) is one of the most common gynaecologic malignancies. Deleted in malignant brain tumors 1 (DMBT1) was considered as a tumour suppressor in multiple cancers, but there have been no systemic profiling studies of DMBT1 in OC until now. The aim of this study is to explore the role and the potential mechanism of DMBT1 in OC. mRNA levels and protein expressions of corresponding genes were detected by quantitative real‐time polymerase chain reaction and western blot. Cell proliferation was detected by CCK‐8 assay and cell colony formation. Cell migration and invasion were detected by wound healing and transwell assay. The combination between DMBT1 and galectin‐3 was demonstrated by immunoprecipitation. We demonstrated that DMBT1 was downregulated in OC cell lines, especially SKOV3 cells. Overexpression of DMBT1 significantly inhibited cell proliferation, colony formation, migration and invasion, as well as decreased Matrix Metalloproteinase‐2 (MMP‐2) and MMP‐7. DMBT1 caused a reduction of cell viability by treatment with cisplatin. Immunoprecipitation assay revealed a combination between DMBT1 and galectin‐3. DMBT1 could decrease the expression of galectin‐3 and inhibit the phosphorylation of PI3K and AKT, while overexpression of galectin‐3 reversed this effect. In summary, DMBT1 might inhibit the progression of OC and improve the sensitivity of SKOV3 cells to cisplatin through galectin‐3/PI3K/AKT pathway, giving a new insight into the role of DMBT1 in OC and enriching the potential strategies for OC treatment.

Significance of the Study

The present study focus on the role and the potential mechanism of DMBT1 in ovarian cancer (OC). We demonstrated that DMBT1 might inhibit the progression of ovarian by inhibiting cell proliferation, migration and invasion and increased the sensitivity to cisplatin through galectin‐3/PI3K/AKT pathway. The findings ensure the interaction relation between DMBT1 and galectin‐3 in OC, providing a novel biological marker for OC and enriching the potential strategies for OC treatment.
End‐stage renal disease as an independent risk factor for in‐hospital mortality after coronary drug‐eluting stenting: Understanding and modeling the risk
Authors: Dunn Aaron N. , Huded Chetan , Simpfendorfer Conrad , Raymond Russell , Kapadia Samir , Tuzcu E. Murat , Ellis Stephen G.
Published: May 2020

Objectives

We sought to compare in‐hospital outcomes between patients with and without end‐stage renal disease (ESRD) undergoing coronary drug‐eluting stent (DES) placement and to model risk of in‐hospital adverse postpercutaneous coronary intervention (PCI) events in ESRD patients.

Background

The effect of ESRD on the risk of in‐hospital complications after DES PCI is relatively unclear, as is the ability to prospectively stratify risk in this population.

Methods

Consecutive patients undergoing first‐time DES between April 1, 2003 and June 30, 2018 at a single tertiary care hospital were included in a prospective registry. Outcomes in those with ESRD were compared to those without ESRD. The primary endpoint was in‐hospital all‐cause mortality; secondary endpoints included in‐hospital major adverse cardiac events (MACE)—defined as cardiac death, myocardial infarction, or unplanned revascularization—and major bleeding. Multivariate logistic regression modeling was used to identify factors associated with each outcome and to generate risk scores.

Results

Among 18,134 patients in the study population, 382 (2.1%) had ESRD. ESRD was associated with increased risk of in‐hospital mortality (7.1 vs. 2.9%, p < .001), in‐hospital MACE (6.3 vs. 2.1%, p < .001), and major bleeding (12.0 vs. 2.6%, p < .001). After multivariable risk adjustment, ESRD was independently associated with in‐hospital mortality (odds ratio: 1.83, 95% confidence interval: 1.04–3.23, p = .04) but not MACE or major bleeding. Among patients with ESRD, risks of MACE and major bleeding were successfully modeled (c‐statistics = .72 and .85, respectively).

Conclusions

ESRD is independently associated with increased risk of in‐hospital mortality after coronary DES. Future studies are necessary to validate risk models derived to identify high‐risk ESRD patients.
Flexible and Epitaxial Metal Oxide Thin Film Growth by Photoreaction Processing for Electrical and Optical Applications
Authors: Tsuchiya Tetsuo , Nakajima Tomohiko , Uzawa Yuko
Published: May 2020

This review summarizes the use of photoreactions that replace conventional heating processes for growing oxide thin films from chemical solutions. In particular, this review outlines key variables in photoreactions that affect epitaxial and polycrystalline thin film growth, including precursor materials, laser wavelength, laser fluence, and carbon. In addition, the features of the photoreaction process that can be controlled at a low temperature by oxygen non‐stoichiometry are examined. Likewise, functions that are neither achieved by developing a gradient structure nor controlled by a thermal equilibrium reaction are detailed. Two new concepts are presented, known as photoreaction of nanoparticles (PRNP) and photoreaction of a hybrid solutions (PRHS), in which crystal nuclei are pre‐dispersed in a metal–organic compound film. This method has successfully produced flexible phosphor films used as resistor or thermistor electronic components. Finally, thin film growth using different light sources such as flash lamps and femtosecond lasers (fs) is explored.
Synthesis of Heterocycles through Denitrogenative Cyclization of Triazoles and Benzotriazoles
Authors: Li Wenbo , Zhang Junliang
Published: May 2020

During the past few decades, there has been considerable growth in the development of denitrogenative reactions of triazole skeletons to construct valuable cyclic compounds, particularly heterocycles. Despite the inherent difficulty of the ring‐opening of triazole derivatives, many novel and efficient approaches have arisen in this area mainly with the use of transition metal (such as rhodium, palladium, silver, copper) catalysis, photolysis, or free radical mediated reactions. Generally, these procedures begin with the ring‐opening of 1,2,3‐triazoles or benzotriazoles followed by N2extrusion and subsequent diverse transformations, which enable the rapid synthesis of various heterocycles in a single step. To avoid overlap with other related reviews, this minireview covers the recent advances in the denitrogenative cyclization of 1,2,3‐triazoles since 2016 and the denitrogenative cyclization of benzotriazoles since 2012.
A Lamellar MWW Zeolite With Silicon and Niobium Oxide Pillars: A Catalyst for the Oxidation of Volatile Organic Compounds
Authors: Schwanke Anderson Joel , Balzer Rosana , Wittee Lopes Christian , Motta Meira Débora , Díaz Urbano , Corma Avelino , Pergher Sibele
Published: May 2020

In this work, an MWW‐type zeolite with pillars containing silicon and niobium oxide was synthesized to obtain a hierarchical zeolite. The effect of niobium insertion in the pillaring process was determined by combining a controllable acidity and accessibility in the final material. All pillared materials had niobium occupying framework positions in pillars and extra‐framework positions. The pillared material, Pil‐Nb‐4.5 with 4.5 wt % niobium, did not compromise the mesoporosity formed by pillaring, while the increase of niobium in the structure gradually decreased the mesoporosity and ordering of lamellar stacking. The morphology of the pillared zeolites and the niobium content were found to directly affect the catalytic activity. Specifically, we report on the activity of the MWW‐type zeolites with niobium catalyzing the gas‐phase oxidation of volatile organic compounds (VOCs), which is an important reaction for clean environmental. All produced MWW‐type zeolites with niobium were catalytically active, even at low temperatures and low niobium loading, and provided excellent conversion efficiencies.
A Dimeric Chromium(II) Pincer as an Electron Shuttle for N=N Bond Scission
Authors: Labrum Nicholas S. , Cabelof Alyssa C. , Caulton Kenneth G.
Published: May 2020

Reduction of the bis‐pyrazolyl pyridine complex [CrL]2 with 4 KC8, followed by addition of one azobenzene (overall mole ratio 1:4:1), PhNNPh, transfers reducing equivalents to three azobenzenes, to form [K3Cr(PhNNPh)3]. This has three κ2 PhNNPh2− ligands and K+ bound to nitrogen atoms of azobenzene. When the stoichiometry is modified to 1:4:3, the product is changed to [K2CrL(PhNNPh)2], which has C2 symmetry except for the intimate ion pairing of two K+ ions to reduced azobenzene nitrogen atoms, and to pyrazolate and phenyl rings. The origin of the observed delivery of reducing equivalents to several, not to a single N=N bond, is traced to the resistance of the one‐electron‐reduced substrate to receiving a second electron, and is thus a general phenomenon. [CrL]2 alone is shown to be a two‐electron reductant towards benzo[c]cinnoline (BCC) resulting in a product of formula [Cr2L2(BCC)], in which the reducing equivalents originate purely from CrII. An analogous study of the reaction of [CrL]2 with azobenzene yields [Cr2L2(PhNNPh)(THF)], an adduct in which one THF has displaced one of four hydrazide nitrogen/Cr bonds. Together these illustrate different modes for the Cr2L2 unit to bind and reduce the N=N bond. Collectively, these results show that two divalent Cr, without added K0, have the ability to reduce the N=N bond. Further KC8 reduction of preformed Cr2L2(RNNR) inevitably gives products in which K+ stabilizes the charge in the increasingly electron‐rich nitrogen atoms, in a phenomenon which mimics proton coupled electron transfer: K+ performs the role of H+. A least‐squares fit of the two singly reduced DFT structures shows that the only major change is a re‐orientation of one of the two phenyl rings in order to avoid repulsion with potassium but to still allow interaction of that phenyl π system with K+. This shows both the impact of K+, being modest to nitrogen/chromium interactions, but nevertheless accommodating some π donation of phenyl to potassium. Finally, delivering increasing equivalents of KC8 leads to complete cleavage of the N=N bond, and both N bind to three CrII. The varied impacts of the K+ electrophile on NN multiple bond reduction is discussed.
Biohybrid Conjugated Polymer Materials for Augmenting Energy Conversion of Bioelectrochemical Systems
Authors: Zhou Xin , Lv Fengting , Huang Yiming , Liu Libing , Wang Shu
Published: May 2020

Bioelectrochemical systems (BESs) provide favorable opportunities for the sustainable conversion of energy from biological metabolism. Biological photovoltaics (BPVs) and microbial fuel cells (MFCs) respectively realize the conversion of renewable solar energy and bioenergy into electrical energy by utilizing electroactive biological extracellular electron transfer, however, along with this energy conversion progress, relatively poor durability and low output performance are challenges as well as opportunities. Advances in improving bio‐electrode interface compatibility will help to solve the problem of insufficient performance and further have a far‐reaching impact on the development of bioelectronics. Conjugated polymers (CPs) with specific optical and electrical properties (absorption and emission spectra, energy band structure and electrical conductivity) afforded by π‐conjugated backbones are conducive to enhancing the electron generation and output capacity of electroactive organisms. Furthermore, the water solubility, functionality, biocompatibility and mechanical properties optimized through appropriate modification of side chain provide a more adaptive contact interface between biomaterials and electrodes. In this minireview, we summarize the prominent contributions of CPs in the aspect of augmenting the photovoltaic response of BPVs and power supply of MFCs, and specifically discussed the role of CPs with expectation to provide inspirations for the design of bioelectronic devices in the future.
N‐Heterocyclic Carbenes Reduce and Functionalize Copper Oxide Surfaces in One Pot
Authors: Veinot Alex J. , Al‐Rashed Abrar , Padmos J. Daniel , Singh Ishwar , Lee Dianne S. , Narouz Mina R. , Lummis Paul A. , Baddeley Christopher J. , Crudden Cathleen M. , Horton J. Hugh
Published: May 2020

Benzimidazolium hydrogen carbonate salts have been shown to act as N‐heterocyclic carbene precursors, which can remove oxide from copper oxide surfaces and functionalize the resulting metallic surfaces in a single pot. Both the surfaces and the etching products were fully characterized by spectroscopic methods. Analysis of surfaces before and after NHC treatment by X‐ray photoelectron spectroscopy demonstrates the complete removal of copper(II) oxide. By using 13C‐labelling, we determined that the products of this transformation include a cyclic urea, a ring‐opened formamide and a bis‐carbene copper(I) complex. These results illustrate the potential of NHCs to functionalize a much broader class of metals, including those prone to oxidation, greatly facilitating the preparation of NHC‐based films on metals other than gold.
Dibenzothiophenesulfilimines: A Convenient Approach to Intermolecular Rhodium‐Catalysed C−H Amidation
Authors: Antoni Patrick W. , Mackenroth Alexandra V. , Mulks Florian F. , Rudolph Matthias , Helmchen Günter , Hashmi A. Stephen K.
Published: May 2020

A sulfilimine‐based Group 9 transition‐metal‐catalysed C−H amidation procedure is reported. Dibenzothiophene‐based sulfilimines were shown to constitute a class of novel amidation reagents which enable the transfer of a wide range of N‐sulfonyl and N‐acyl moieties. It was demonstrated that sulfilimines, which are easily accessible from cheap reagents, are safe‐to‐handle and represent broadly applicable amidation reagents. The dibenzothiophene can be recycled after use. The C−H amidation was shown to proceed with high selectivity and gave the mono‐amidated products, mostly in good to excellent yields.
QTc interval evaluation in patients with right bundle branch block or bifascicular blocks
Authors: Erkapic Damir , Frommeyer Gerrit , Brettner Niklas , Sözener Korkut , Crijns Harry J. G. M. , Seyfarth Melchior , Hamm Christian W. , Bogossian Harilaos
Published: May 2020

Background

The right bundle branch block (RBBB) and the bifascicular blocks affect QRS duration in the right precordial leads, which are usually used for QT interval determination. Up to now, there is no clear recommendation how to determine QT interval in patients with RBBB or bifascicular block.

Hypothesis

The hypothesis of the present study was to evaluate the feasibility of a simple formula for RBBB and bifascicular block correction, thereby making it easier to determine the QTc interval.

Methods

In patients with intrinsic QRS duration <120 ms, artificial RBBB with either left posterior (LPFB) or left anterior fascicular block (LAFB), created by left ventricular pacing maneuvers, were corrected using the Bogossian formula (QTm) and afterward were heart rate corrected (QTmc). Heart rate correction was performed using different heart rate formulas in comparison to each other. The QTmc intervals were compared in each patient with the QTc interval during intrinsic rhythm.

Results

A total of scheduled 71 patients were included in this prospective multicenter observational comparative study. Compared to intrinsic QTc interval, the mean ΔQTmc interval by combination of the Bogossian and the Hodge formulas was −3 ± 24 ms in RBBB + LPFB (P = .44) and −6 ± 25 ms in RBBB + LAFB (P = .15). The Bogossian formula showed a significant deviation from the actual QTc interval with both the Bazett and the Fridericia formulas.

Conclusion

In combination with the Hodge formula, the Boggosian formula delivered the best results in comparing the true QTc interval in narrow QRS with the QTmc interval in the presence of a bifascicular block.
Divergent Synthesis of Novel Cylindrocyclophanes that Inhibit Methicillin‐Resistant Staphylococcus aureus (MRSA)
Authors: Freudenreich Julien J. , Bartlett Sean , Robertson Naomi S. , Kidd Sarah L. , Forrest Suzie , Sore Hannah F. , Galloway Warren R. J. D. , Welch Martin , Spring David R.
Published: May 2020

The cylindrocyclophanes are a family of macrocyclic natural products reported to exhibit antibacterial activity. Little is known about the structural basis of this activity due to the challenges associated with their synthesis or isolation. We hypothesised that structural modification of the cylindrocyclophane scaffold could streamline their synthesis without significant loss of activity. Herein, we report a divergent synthesis of the cylindrocyclophane core enabling access to symmetrical macrocycles by means of a catalytic, domino cross‐metathesis‐ring‐closing metathesis cascade, followed by late‐stage diversification. Phenotypic screening identified several novel inhibitors of methicillin‐resistant Staphylococcus aureus. The most potent inhibitor has a unique tetrabrominated [7,7]paracyclophane core with no known counterpart in nature. Together these illustrate the potential of divergent synthesis using catalysis and unbiased screening methods in modern antibacterial discovery.
Design and Synthesis of New Pyrazole‐Based Heterotricycles and their Derivatization by Automated Library Synthesis
Authors: Fricero Prisca , Bialy Laurent , Czechtizky Werngard , Méndez María , Harrity Joseph P. A.
Published: May 2020

Small‐molecule heterocycles bearing orthogonal functionality have the potential to deliver diverse structural motifs that aid the drug‐discovery effort. This work highlights how a readily assembled N‐hydroxyethyl pyrazole trifluoroborate offers rapid access to architecturally distinct 5‐6‐6‐ and 5‐7‐6‐fused tricyclic compounds. This chemistry is not only amenable to single compound synthesis, but also to high‐throughput experimentation. It gives easy access to diverse compound arrays with various physicochemical and ADME profiles by fully automated library synthesis. The combination of the high‐throughput experimentation with rapid testing of the compounds in an integrated physicochemical and ADME profiling workflow allows accelerated design of novel lead compounds in drug‐discovery projects.
Therapy after cyclin‐dependent kinase inhibition in metastatic hormone receptor‐positive breast cancer: Resistance mechanisms and novel treatment strategies
Authors: Sharifi Marina N. , Anandan Apoorva , Grogan Patrick , O’Regan Ruth M.
Published: May 2020

Endocrine therapy has been the standard of care for patients with metastatic hormone receptor (HR)‐positive, HER2‐negative breast cancer since the 1970s, improving survival while avoiding the toxicities associated with cytotoxic chemotherapy. However, all HR‐positive tumors ultimately develop resistance to endocrine therapy. Cyclin‐dependent kinase 4 and 6 (CDK4/6) inhibitors have more recently become an important component of the management of this breast cancer subtype, significantly delaying time to the disease progression and improving survival when combined with endocrine therapy. However, as with endocrine therapy alone, treatment resistance remains a universal phenomenon. As more women receive CDK4/6 inhibitors as part of their treatment, the management of de novo and acquired resistance to combined CDK4/CDK6 inhibitor plus endocrine therapy regimens has emerged as an important clinical challenge. Several resistance mechanisms have been described, including alterations in the CDK4/6/cyclin D complex or its major effector retinoblastoma protein (pRb), bypass signaling through other cyclin/CDK complexes and activation of upstream signaling pathways, in particular the PI3K/mTOR pathway, but robust biomarkers to predict resistance remain elusive, and the role for continuing CDK4/6 inhibitors after progression remains under investigation. Novel strategies being evaluated in clinical trials include the continuation of CDK4/6 inhibitors through progression, as well as triplet therapy combinations with PI3K inhibitors or immune checkpoint inhibitors.
Assessing second cancer risk after primary cancer treatment with photon or proton radiotherapy
Authors: DeLaney Thomas F. , Yock Torunn I. , Paganetti Harald
Published: May 2020

In this issue, Xiang and colleagues present data from the National Cancer Database comparing the number of second malignancies observed in adult and pediatric patients with 9 major cancer subtypes who received different radiation modalities. These are important findings because understanding the risk of late, radiation‐associated malignancies with different radiation modalities may help physicians reduce the risk of this devastating late treatment effect.
Incorporating patient preferences into cancer care decisions: Challenges and opportunities
Authors: Veenstra Christine M. , Hawley Sarah T.
Published: May 2020

Without innovations, ensuring that patients' preferences are fully incorporated into cancer care planning will remain a challenge. It is time to move beyond documenting discrepancies in the patient‐clinician preference setting to ensuring patients' preferences and values are routinely included in treatment planning.
Functionalization of Tile‐based DNA Nanocages with Gold Nanoparticles (AuNPs) to Form AuNP Cluster‐DNA Cage Hybrids
Authors: Yu Yang , Lei Yunxiang , Dong Qiang , Li Yulin
Published: May 2020

Attaching functional nanomaterials onto tile‐based DNA nanocages to form hybrids consisting of DNA nanocages and nanomaterial clusters with well‐defined compositions might not only integrate the functions of each component, but also potentially lead to new emergent properties and applications. Herein, we report a general and facile hybridization‐driven approach for functionalizing tile‐based nanocages with gold nanoparticles (AuNPs) to form AuNP cluster‐DNA cage hybrids. AuNP tetramer‐DNA tetrahedron hybrids and AuNP octamer‐DNA octahedron complexes have been successfully fabricated. Our hybridization‐based strategy could in principle be extended to fabricate various hybrids with designable compositions and structures due to the diversity of tile‐based nanocages and the great variety of functional nanomaterials that could be modified with DNA, which should hold the promise of greatly promoting the research of bio/nanoassembly.
Pharmacokinetics of Gepotidacin in Renal Impairment
Authors: Hossain Mohammad , Tiffany Courtney , Raychaudhuri Aparna , Nguyen Dung , Tai Guoying , Alcorn Harry , Preston Richard A. , Marbury Thomas , Dumont Etienne
Published: May 2020

Gepotidacin is a novel triazaacenaphthylene bacterial topoisomerase inhibitor. In this phase 1, nonrandomized, open‐label, parallel‐group, multicenter, multipart study, the pharmacokinetics, safety, and tolerability of a single intravenous (IV) dose of gepotidacin 750 mg over 2 hours were evaluated in subjects with normal renal function, in those with moderate and severe renal impairment, and in end‐stage renal disease (ESRD) on and not on dialysis. Administration of IV gepotidacin 750 mg was safe and generally tolerated in the study subjects. Dosing in severe renal impairment with and without hemodialysis resulted in significant increases in plasma drug levels and decreases in clearance. The geometric mean elimination half‐life (t½) was minimally impacted (range 9.45 to 11.5 hours) in all the renal‐impairment groups relative to normal renal function. Regardless of renal function, urine gepotidacin concentrations remained considerably high over a 12‐hour period. Saliva concentrations displayed a linear relationship with plasma concentrations. The t½ in saliva was not impacted in the moderate‐impairment and ESRD subjects and was comparable to t½ in plasma. Over a 4‐hour dialysis, approximately 6% of the gepotidacin dose was removed. Overall, subjects with severe renal impairment and ESRD with and without hemodialysis may require adjustment in dose or dosing frequency.
Using image object recognition to increase biomass in red clover (Trifolium pratense L.) breeding
Authors: Sindic Caleb M.T. , Riday Heathcliffe
Published: May 2020

Phenotyping in forage legume breeding can be time consuming and resource intensive. With computation advances and computational power cost reductions, utilizing artificial intelligence in automated phenotyping is becoming feasible for even resource limited forage legume breeding programs. Here we report on the use of machine learning to train a neural network to identify and isolate red clover plants from digital images of space planted red clover nurseries. Challenges to red clover plant identification included: 1) plants were grown with a grass companion; and 2) plants were close enough to each other so that plants often overlapped each other in the digital images. To estimate biomass yield a second neural network was trained using machine learning to count leaves per plant among identified red clover plants from the plant classification neural network. The two neural networks were validated on six red clover digital image sets taken on red clover space plant nurseries. Average neural network plant classification success rates were measured at 94.6% across the six digital image sets. Neural network red clover leaf counts were correlated with human visual biomass scores at r2 = 0.528. We conclude that automated phenotyping based on digital image analysis of red clover breeding nurseries is currently feasible. We further conclude that additional phenotypic traits could be obtained on identified red clover plants from such images sets.
Aqueous Calcium‐Ion Battery Based on a Mesoporous Organic Anode and a Manganite Cathode with Long Cycling Performance
Authors: Cang Ruibai , Zhao Chunlin , Ye Ke , Yin Jinling , Zhu Kai , Yan Jun , Wang Guiling , Cao Dianxue
Published: May 2020

Aqueous batteries have attracted increasing and extensive attention, owing to their high safety, low cost, and low toxicity. These factors have become increasingly important, given the current focus on the rapid development of green energy technologies. In particular, multivalent‐ion batteries are emerging as alternatives to lithium‐ion batteries. Unfortunately, magnesium and aluminum ions have high polarization strengths that are unfavorable for electrode materials. In contrast, calcium‐ion batteries successfully avoid the problem of high polarization. Herein, an aqueous calcium‐ion battery (CIBs) based on mesoporous silica SBA‐15 with a two‐dimensional hexagonal through‐hole structure is reported. The poly(3,4,9,10‐perylentetracarboxylic diimide) (PPTCDI) organic material supported on SBA‐15 is used as the anode and displays a capacity of 201 mAh g−1, with a stable cycling performance of 95 % capacity retention after 1500 cycles. SBA‐15@PPTCDI‖Ca2MnO4 aqueous CIBs demonstrate a high energy density of 130.6 Wh kg−1 in the cell voltage range from 0.0 to 1.8 V, with a high capacity and excellent cycling stability. As the anode material, SBA‐15@PPTCDI shows special bonding of redox electrons that leads to its highly stable performance, which paves the way for addressing the shortcomings of traditional organic electrode materials. The localization and delocalization of the redox electron offers additional voltage stability, which is another important advantage for practical applications. This study highlights the potential of organic electrode materials for applications in aqueous multivalent‐metal‐ion batteries.
Mini review: The FDA‐approved prescription drugs that induce ovulation in women with ovulatory problems
Authors: Sun Chunlei , Rong Xi , Cai Yongqin , Qiu Song , Farzaneh Maryam
Published: May 2020

Infertility is defined as not being able to become pregnant after 12 months or more of unprotected sexual intercourse. Female infertility as a serious health issue can result from ovulation disorders, menstrual cycle problems, structural problems, and environmental factors. Ovulation occurs once a month between the time of menarche and menopause. The release of a mature egg from the ovary is controlled with the hypothalamic‐pituitary‐ovarian axis. Several hormones such as gonadotropin‐releasing hormone (GnRH), FSH (follicle‐stimulating hormone), LH (luteinizing hormone), estrogen, and progesterone play fundamental roles in the ovulation process. Both FSH and LH are the main treatment for women with ovulation disorders. Depending on the reasons for infertility, several different types of treatment are available for infertile women. Fertility drugs as an important part of treatment work like the natural hormones to treat infertility. Several fertility drugs can regulate ovulation and the release of an egg from the ovary in women with polycystic ovary syndrome (PCOS) or undergoing in vitro fertilization (IVF) treatment. This mini‐review is about the FDA‐approved prescription drugs that induce ovulation in women with ovulatory problems.