bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhanced Electrocaloric Response of Vinylidene Fluoride–Based Polymers via One‐Step Molecular Engineering
Authors: Le Goupil Florian , Kallitsis Konstantinos , Tencé‐Girault Sylvie , Pouriamanesh Naser , Brochon Cyril , Cloutet Eric , Soulestin Thibaut , Domingue Dos Santos Fabrice , Stingelin Natalie , Hadziioannou Georges
Published: September 2020

Electrocaloric refrigeration is one of the most promising environmentally‐friendly technologies to replace current cooling platforms—if a notable electrocaloric effect (ECE) is realized around room temperature where the highest need is. Here, a straight‐forward, one‐pot chemical modification of P(VDF‐ter‐TrFE‐ter‐CTFE) is reported through the controlled introduction of small fractions of double bonds within the backbone that, very uniquely, decreases the lamellar crystalline thickness while, simultaneously, enlarging the crystalline coherence along the a‐b plane. This increases the polarizability and polarization without affecting the degree of crystallinity or amending the crystal unit cell—undesirable effects observed with other approaches. Specifically, the permittivity increases by >35%, from 52 to 71 at 1 kHz, and ECE improves by >60% at moderate electric fields. At 40 °C, an adiabatic temperature change >2 K is realized at 60 MV m−1 (>5.5 K at 192 MV m−1), compared to ≈1.3 K for pristine P(VDF‐ter‐TrFE‐ter‐CTFE), highlighting the promise of a simple, versatile approach that allows direct film deposition without requiring any post‐treatment such as mechanical stretching or high‐temperature annealing for achieving the desired performance.
Emergent Interfacial Ferromagnetism and Exchange Bias Effect in Paramagnetic/Ferromagnetic Oxide Heterostructures
Authors: Bhatt Harsh , Kumar Yogesh , Prajapat Champa Lal , Kinane Christy J. , Caruana Andrew , Langridge Sean , Basu Saibal , Singh Surendra
Published: September 2020

The experimental evidence of the exchange bias (EB) effect in epitaxial heterostructures of ferromagnetic La0.67Sr0.33MnO3 (LSMO) and paramagnetic LaNiO3 (LNO) grown on MgO(001) substrates is reported. The macroscopic magnetization measurements show a clear indication of EB in LNO/LSMO and LSMO/LNO/LSMO heterostructures. The strength of the exchange coupling rapidly reduces as the temperature is increased and almost vanishes above 50 K. Using spin dependent polarized neutron reflectometry (PNR) detailed depth dependent magnetization profiles of the heterostructures are investigated to understand the role of interface magnetism in the observed EB. PNR results establish the emergence of the interfacial ferromagnetic LNO layer of thickness ≈22–35 Å (≈6–9 unit cell) and magnetization ≈80 emu cc−1 at the LNO/LSMO interface for T < 100 K. The PNR results also show both ferromagnetic and anti‐ferromagnetic coupling between the LSMO and interfacial LNO layers, which may be dependent on the stacking order. The emergence of ferromagnetism in the interfacial paramagnetic LNO layer with unexpected EB in these heterostructures suggests a promising platform toward the effective realization of magnetic devices.
Palladium‐Catalyzed Regioselective Domino Spirocyclization of Carbamoyl Chlorides with Alkynes and Benzynes
Authors: Wang Chenchen , Zhao Wenyu , Wu Xianqing , Qu Jingping , Chen Yifeng
Published: September 2020

A palladium‐catalyzed domino spiro‐cyclization of carbamoyl chlorides with alkynes and benzynes, involving intramolecular C−H activation to afford valuable oxindole scaffolds bearing spiro quaternary stereocenters, has been developed. This one‐step synthesis of spirooxindole is both step‐ and atom‐economic, proceeding with high regioselectivity in moderate to excellent yields.

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Equilibrium analysis of CH4, CO, CO2, H2O, H2, C mixtures in C–H–O atom space using Gibbs free energy global minimization
Authors: Chaconas Demetrios , Pichardo Patricia , Manousiouthakis Ioannis V. , Manousiouthakis Vasilios I.
Published: September 2020

Gibbs free energy minimization is employed to carry out thermodynamic equilibrium analysis studies of mixtures containing methane, carbon monoxide, carbon dioxide, water, and hydrogen ideal gases, and possibly solid carbon. The employed global minimization approach represents a general, unifying, conceptual framework that allows reaction and phase equilibrium analysis to be simultaneously carried out in the atom‐mol fraction space (aH, aO), thus capturing in a comprehensive manner the equilibrium behavior of a number of industrially important processes, such as methane reforming (steam, dry, energetically enhanced), and methanation. Two theorems are presented, establishing necessary and sufficient (necessary) feasibility and regularity (optimality) conditions for the aforementioned minimization problem. The equilibrium results obtained through application of these theorems are guaranteed to be globally optimal. They quantify in (aH, aO) space, the feasible region, the carbon formation region, and all species mole over total atom‐mol normalized ratios, for a range of temperatures and pressures.
Inducible DNA Polymerase Chain Reaction Triggered by Oxidative Species
Authors: Wang Sheng , Zhao Jizhong , Wang Li , Zhang Jingwen , Hu Hongmei , Yu Ping , Wang Rui
Published: September 2020

We report here a chemically synthetic method to introduce a PinB‐modified thymidine into well‐defined DNA first. The modification was designed to disturb the T−A base‐pairing, thus regulate the DNA activity for PCR amplification. By treatment with small molecules, i. e., reactive oxygen species, the DNA polymerase activity was successfully restored. Due to tight temporal regulation and cell‐membrane permeability, our approach could lead to application potential in live cell.
An image analysis protocol for the quantification of interglobular dentine in anthropological tooth sections
Authors: Snoddy Anne Marie E. , Miszkiewicz Justyna J. , Loch Carolina , Tromp Monica , Buckley Hallie R.
Published: September 2020

The histological identification of interglobular dentine (IGD) in archeological human remains with macroscopic evidence of rickets has opened a promising new avenue for the investigation of metabolic disease in the past. Recent paleopathological studies have shown that histological analysis of archeological human teeth may allow the identification of periods of vitamin D deficiency occurring within very narrow developmental  windows, yielding new information on the seasonality or even maternal‐fetal transmission of this disease. However, currently available techniques for recording IGD rely on subjective scoring systems or visual estimations, potentially leaving them open to inter and intra‐observer error and rendering comparisons of datasets difficult. Here we describe a new imaging protocol that utilizes open access software and may yield more objective and quantitative data on the amount of IGD present within a dentinal region of interest. We demonstrate that grayscale histograms in FIJI®/ImageJ® might be used to provide less subjective estimates of the percentage of a region of interest affected by IGD. Application of this technique may enable more accurate comparison of datasets between researchers.
Azithromycin in high‐risk, refractory chronic rhinosinusitus after endoscopic sinus surgery and corticosteroid irrigations: a double‐blind, randomized, placebo‐controlled trial
Authors: Maniakas Anastasios , Asmar Marc‐Henri , Renteria Axel Eluid , Nayan Smriti , Alromaih Saud , Endam Leandra Mfuna , Sampalis John Sam , Desrosiers Martin
Published: September 2020

Background

Refractory chronic rhinosinusitis (CRS) remains a significant burden for patients, often leaving them with few therapeutic options that provide low‐morbidity, long‐term, and meaningful symptomatologic and endoscopic disease improvement. Macrolides have long been thought to offer both an immunomodulatory and antimicrobial effect. Our objective was to evaluate the efficacy of low‐dose, long‐term azithromycin in a carefully selected high‐risk population failing appropriate medical therapy of budesonide nasal irrigations (BNIs) and endoscopic sinus surgery (ESS).

Methods

A double‐blind, randomized, placebo‐controlled trial was completed in a single tertiary‐care center assessing the addition of 250 mg azithromycin, 3 times per week for 16 weeks, in adults failing ESS and high‐volume BNIs. Associated comorbidities, as well as symptomatologic, microbiologic, and serologic values, were systematically collected.

Results

A total of 128 patients were enrolled and underwent ESS followed by BNI. At the 4‐month post‐ESS visit, 48 patients showed disease persistence and were randomized to azithromycin or placebo. Overall, azithromycin, when compared with placebo, did not show a statistically significant difference in disease clearance (54% vs 33%, respectively; p = 0.146), although patients with disease clearance who were on azithromycin showed significantly better 22‐item Sino‐Nasal Outcome Test score improvements than patients on placebo (18 vs −0.9, respectively; p = 0.046). In a subgroup analysis excluding aspirin‐exacerbated respiratory disease (AERD) patients, azithromycin significantly improved disease clearance when compared with placebo (71% vs 35%, respectively; p = 0.031), with a number needed to treat of 3 (2.8).

Conclusion

Low‐dose azithromycin is a therapeutic option with few side effects. Its use can show favorable clinical outcomes in this difficult‐to‐treat population, especially if patients are AERD‐negative.
Quantitative Protein Corona Composition and Dynamics on Carbon Nanotubes in Biological Environments
Authors: Pinals Rebecca L. , Yang Darwin , Rosenberg Daniel J. , Chaudhary Tanya , Crothers Andrew R. , Iavarone Anthony T. , Hammel Michal , Landry Markita P.
Published: September 2020

When nanoparticles enter biological environments, proteins adsorb to form the “protein corona” which alters nanoparticle biodistribution and toxicity. Herein, we measure protein corona formation on DNA‐functionalized single‐walled carbon nanotubes (ssDNA‐SWCNTs), a nanoparticle used widely for sensing and delivery, in blood plasma and cerebrospinal fluid. We characterize corona composition by mass spectrometry, revealing high‐abundance corona proteins involved in lipid binding, complement activation, and coagulation. We investigate roles of electrostatic and entropic interactions driving selective corona formation. Lastly, we study real‐time protein binding on ssDNA‐SWCNTs, obtaining agreement between enriched proteins binding strongly and depleted proteins binding marginally, while highlighting cooperative adsorption mechanisms. Knowledge of protein corona composition, formation mechanisms, and dynamics informs nanoparticle translation from in vitro design to in vivo application.
A Versatile Method for Kinetic Resolution of Protecting‐Group‐Free BINAMs and NOBINs through Chiral Phosphoric Acid Catalyzed Triazane Formation
Authors: Liu Wei , Jiang Qianwen , Yang Xiaoyu
Published: September 2020

A versatile kinetic resolution of protecting‐group‐free BINAMs and NOBINs has been realized through chiral phosphoric acid catalyzed triazane formation with azodicarboxylates. A series of mono‐N‐protected and unprotected BINAMs, diphenyl diamines and NOBIN derivatives could be kinetically resolved with excellent performances (with s factor up to 420). The gram‐scale reactions and facile derivatizations of the chiral products demonstrate the potential of these methods in the asymmetric synthesis of chiral catalysts and ligands.
Co‐Assembly between Fmoc Diphenylalanine and Diphenylalanine within a 3D Fibrous Viscous Network Confers Atypical Curvature and Branching
Authors: Chakraborty Priyadarshi , Tang Yiming , Guterman Tom , Arnon Zohar A. , Yao Yifei , Wei Guanghong , Gazit Ehud
Published: September 2020

Supramolecular polymer co‐assembly is a useful approach to modulate peptide nanostructures. However, the co‐assembly scenario where one of the peptide building blocks simultaneously forms a hydrogel is yet to be studied. Herein, we investigate the co‐assembly formation of diphenylalanine (FF), and Fmoc‐diphenylalanine (FmocFF) within the 3D network of FmocFF hydrogel. The overlapping peptide sequence between the two building blocks leads to their co‐assembly within the gel state modulating the nature of the FF crystals. We observe the formation of branched microcrystalline aggregates with an atypical curvature, in contrast to the FF assemblies obtained from aqueous solution. Optical microscopy reveal the sigmoidal kinetic growth profile of these aggregates. Microfluidics and ToF‐SIMS experiments exhibit the presence of co‐assembled structures of FF and FmocFF in the crystalline aggregates. Molecular dynamics simulation was used to decipher the mechanism of co‐assembly formation.
Fluorescent Self‐Threaded Peptide Probes for Biological Imaging
Authors: Zhai Canjia , Schreiber Cynthia L. , Padilla‐Coley Sasha , Oliver Allen G. , Smith Bradley D.
Published: September 2020

A general synthetic method creates a new class of covalently connected, self‐threaded, fluorescent molecular probes with figure‐eight topology, an encapsulated deep‐red fluorophore, and two peripheral peptide loops. The globular molecular shape and rigidified peptide loops enhance imaging performance by promoting water solubility, eliminating probe self‐aggregation, and increasing probe stability. Moreover, the peptide loops determine the affinity and selectivity for targets within complex biological samples such as cell culture, tissue histology slices, or living subjects. For example, a probe with cell‐penetrating peptide loops targets the surface of cell plasma membranes, whereas, a probe with bone‐targeting peptide loops selectively stains the skeleton within a living mouse. The unique combination of bright deep‐red fluorescence, high stability, and predictable peptide‐based targeting is ideal for photon intense fluorescence microscopy and biological imaging.
Concise Total Synthesis of Tronocarpine
Authors: Nakayama Atsushi , Nakamura Tenta , Zaima Toshihiro , Fujimoto Saho , Karanjit Sangita , Namba Kosuke
Published: September 2020

A concise total synthesis of tronocarpine, a chippiine‐type indole alkaloid, was accomplished. The key feature of this total synthesis is a one‐pot construction of the pentacyclic skeleton containing an azabicyclo[3.3.1]nonane core by tandem cyclization from an indole derivative with all carbon side chains and functional groups. This tandem cyclization consists of α,β‐unsaturated aldehyde formation, intramolecular aldol reaction, six‐membered lactamization, azide reduction, and seven‐membered lactamization. The stereochemical outcome in this tandem cyclization is controlled by the stereocenter at the C14 position. This strategy can be utilized to synthesize other chippiine‐type alkaloids with azabicyclo[3.3.1]nonane skeletons.
Frustrated Radical Pairs: Insights from EPR Spectroscopy
Authors: Dasgupta Ayan , Richards Emma , Melen Rebecca L.
Published: September 2020

Progress in frustrated Lewis pair (FLP) chemistry has revealed the importance of the main group elements in catalysis, opening new avenues in synthetic chemistry. Recently, new reactivities of frustrated Lewis pairs have been uncovered that disclose that certain combinations of Lewis acids and bases undergo single‐electron transfer (SET) processes. Here an electron can be transferred from the Lewis basic donor to a Lewis acidic acceptor to generate a reactive frustrated radical pair (FRP). This minireview aims to showcase the recent advancements in this emerging field covering the synthesis and reactivities of frustrated radical pairs, with extensive highlights of the results from Electron Paramagnetic Resonance (EPR) spectroscopy to explain the nature and stability of the different radical species observed.
Face‐Directed Assembly of Molecular Cubes: In Situ Substitution of a Predetermined Concave Cluster
Authors: Gong Yaru , Qin Chao , Zhang Yuteng , Sun Chunyi , Pan Qinhe , Wang Xinlong , Su Zhongmin
Published: September 2020

Systematic design and self‐assembly of metal–organic polyhedra with predictable configurations has been a long‐standing challenge in crystal engineering. Herein a concave polyoxovanadate cluster, [V6O6(OCH3)9(SO4)4]5−, which can be generated in situ under specific reaction conditions, is reported. Based on this cluster, a potential trivalent molecular building block, [V6O6(OCH3)9(SO4)(CO2)3]2−, can be obtained by the bridging‐ligand‐substitution strategy and it possesses appropriate angle information for the design of molecular cubes. Utilizing the face‐directed assembly of the trivalent molecular building block and a diverse set of tetratopic carboxylate linkers, a series of metal–organic cubes (VMOC‐1–VMOC‐5) with the same topology but different functionalities and dimensions were designed and constructed. An inclusion study using VMOC‐3 shows that they are potential molecular receptors for selective capture of size‐matching polycyclic aromatic hydrocarbon guest molecules.
A Hydrogen‐Bonded yet Hydrophobic Porous Molecular Crystal for Molecular‐Sieving‐like Separation of Butane and Isobutane
Authors: Ye Zi‐Ming , Zhang Xue‐Wen , Liao Pei‐Qin , Xie Yi , Xu Yan‐Tong , Zhang Xue‐Feng , Wang Chao , Liu De‐Xuan , Huang Ning‐Yu , Qiu Ze‐Hao , Zhou Dong‐Dong , He Chun‐Ting , Zhang Jie‐Peng
Published: September 2020

Porous molecular crystals sustained by hydrogen bonds and/or weaker connections are an intriguing type of adsorbents, but they rarely demonstrate efficient adsorptive separation because of poor structural robustness and tailorability. Herein, we report a porous molecular crystal based on hydrogen‐bonded cyclic dinuclear AgI complex, which exhibits exceptional hydrophobicity with a water contact angle of 134°, and high chemical stability in water at pH 2–13. The seemingly rigid adsorbent shows a pore‐opening or nonporous‐to‐porous type butane adsorption isotherm and complete exclusion of isobutane, indicating potential molecular sieving. Quantitative column breakthrough experiments show slight co‐adsorption of isobutane with an experimental butane/isobutane selectivity of 23, and isobutane can be purified more efficiently than for butane. In situ powder/single‐crystal X‐ray diffraction and computational simulations reveal that a trivial guest‐induced structural transformation plays a critical role.
Toward Flexible Zinc‐Ion Hybrid Capacitors with Superhigh Energy Density and Ultralong Cycling Life: The Pivotal Role of ZnCl2 Salt‐Based Electrolytes
Authors: Wang Cheng , Pei Zengxia , Meng Qiangqiang , Zhang Chunmei , Sui Xiao , Yuan Ziwen , Wang Sijie , Chen Yuan
Published: September 2020

Zinc ion hybrid capacitors (ZIHCs) are promising energy storage devices for emerging flexible electronics, but they still suffer from trade‐off in energy density and cycling life. Herein, we show that such a dilemma can be well‐addressed by deploying ZnCl2 based electrolytes. Combining experimental studies and density functional theory (DFT) calculations, for the first time, we demonstrate an intriguing chloride ion (Cl−) facilitated desolvation mechanism in hydrated [ZnCl]+(H2O)n−1 (with n=1–6) clusters. Based on this mechanism, a water‐in‐salt type hydrogel electrolyte filled with ZnCl2 was developed to concurrently improve the energy storage capacity of porous carbon materials and the reversibility of Zn metal electrode. The resulting ZIHCs deliver a battery‐level energy density up to 217 Wh kg−1 at a power density of 450 W kg−1, an unprecedented cycling life of 100 000 cycles, together with excellent low‐temperature adaptability and mechanical flexibility.
Cobalt‐Catalyzed Markovnikov‐Type Selective Hydroboration of Terminal Alkynes
Authors: Chen Jieping , Shen Xuzhong , Lu Zhan
Published: September 2020

A cobalt‐catalyzed Markovnikov‐type hydroboration of terminal alkynes with HBpin to access α‐alkenyl boronates with good regioselectivity and atom economy is reported. A new ligand has been developed for the cobalt hydride catalyst that has been used for a unique Markovnikov selective insertion of terminal alkynes into metal hydride bond. This operationally simple protocol exhibits excellent functional group tolerance to deliver valuable alkene derivatives.
Broadband Dynamics of Ubiquitin by Anionic and Cationic Nanoparticle Assisted NMR Spin Relaxation
Authors: Wardenfelt Stacey , Xiang Xinyao , Xie Mouzhe , Yu Lei , Bruschweiler‐Li Lei , Brüschweiler Rafael
Published: September 2020

The quantitative and comprehensive description of the internal dynamics of proteins is critical for understanding their function. Nanoparticle‐assisted 15N NMR spin relaxation spectroscopy is a new method for the observation of picosecond to microsecond dynamics of proteins when transiently interacting with the surface of the nanoparticles (NPs). The method is applied here to the protein ubiquitin in the presence of anionic and cationic silica NPs (SNPs) of different sizes. The backbone dynamics profiles are reproducible and strikingly similar to each other, indicating that specific protein–SNP interactions are unimportant. The dynamics profiles closely match the sub‐nanosecond dynamics S2 values observed by model‐free analysis of standard 15N relaxation of ubiquitin in free solution, indicating that the bulk of the ubiquitin backbone dynamics in solution is confined to sub‐nanosecond timescales and, hence, it is dynamically more restrained than previous NMR studies have suggested.
LEAD‐m6A‐seq for Locus‐Specific Detection of N6‐Methyladenosine and Quantification of Differential Methylation
Authors: Wang Yuru , Zhang Zijie , Sepich‐Poore Caraline , Zhang Lisheng , Xiao Yu , He Chuan
Published: September 2020

N6‐methyladenosine (m6A) is a crucial RNA chemical mark which plays important roles in various biological processes. The development of highly multiplexed, cost‐effective, and easy‐to‐operate methodologies for locus‐specific analysis of m6A is critical for advancing our understanding of the roles of this modification. Herein, we report a method which builds upon the principle of the previously reported SELECT approach by significantly improving its efficiency and coupling it to next generation sequencing technology for high‐throughput validation and detection of m6A modification at selected sites (LEAD‐m6A‐seq). Through probing cDNA extension mediated by Bst DNA polymerase at and near target cellular sites by sequencing, we evaluated m6A modification at these sites, and estimated differential methylation levels (0–84 %) upon in vitro demethylation by the m6A demethylase FTO with high reproducibility. We envision that this strategy can be readily used for testing a greater number of sites with a broad dynamic range and modified to study other RNA modifications.
From Sergeants and Soldiers to Chiral Conflict Effects in Helical Polymers by Acting on the Conformational Composition of the Comonomers
Authors: Cobos Katherine , Rodríguez Rafael , Quiñoá Emilio , Riguera Ricardo , Freire Félix
Published: September 2020

Different communication mechanisms can be switched within a copolymer by acting on the conformational composition of the components and their chirality. Thus, a sergeant and soldiers effect is produced in two diastereomeric copolymer series, poly[(S)‐1r‐co‐(S)‐2(1−r)] and poly[(R)‐1r‐co‐(S)‐2(1−r)], owing to the presence in chloroform of a preferred conformation in (S)‐2, and a conformational equilibrium in 1, where a P helix is induced independently of the absolute configuration of the soldier. In THF, the presence of a conformational equilibrium at the pendants of the two components produces a reciprocal chiral enhancement effect by copolymerization of the two monomers, while in DMF, a third chiral to chiral communication switch is produced due to the presence of a single conformer at the pendant group of the two components. In such a case, a chiral conflict or chiral accord effect is produced depending if the two components induce the same or the opposite helical sense.
Reductive Hexamerization of CO Involving Cooperativity Between Magnesium(I) Reductants and [Mo(CO)6]: Synthesis of Well‐Defined Magnesium Benzenehexolate Complexes**
Authors: Paparo Albert , Yuvaraj K. , Matthews Aidan J. R. , Douair Iskander , Maron Laurent , Jones Cameron
Published: September 2020

Reactions of two magnesium(I) compounds, [{(ArNacnac)Mg}2] (ArNacnac=[HC(MeCNAr)2]−; Ar=mesityl (Mes) or o‐xylyl (Xyl)), with CO in the presence of [Mo(CO)6] lead to the reductive hexamerization of CO, and formation of magnesium benzenehexolate complexes, [{(ArNacnac)Mg}6(C6O6)]. [Mo(CO)6] is not consumed in these reactions, but is apparently required to initiate (or catalyze) the CO hexamerizations. A range of studies were used to probe the mechanism of formation of the benzenehexolate complexes. The magnesium(I) reductive hexamerizations of CO are closely related to Liebig's reduction of CO with molten potassium (to give K6C6O6, amongst other products), originally reported in 1834. As the mechanism of that reaction is still unknown, it seems reasonable that magnesium(I) reductions of CO could prove useful homogeneous models for its elucidation, and for the study of other C−C bond forming reactions that use CO as a C1 feedstock (e.g. the Fischer–Tropsch process).
Amino‐Supported Palladium Catalyst for Chemo‐ and Stereoselective Domino Reactions
Authors: Li Man‐Bo , Yang Jie , Yang Ying , Xu Guo‐Yong , Luo Gen , Yang Jianping , Bäckvall Jan‐E.
Published: September 2020

A solid amino‐supported palladium catalyst is used in an oxidative domino reaction for the diastereoselective construction of alkyne‐substituted cyclopentenol compounds. This heterogeneous catalyst exhibits high efficiency and excellent chemoselectivity, as well as good recyclability. The chemoselectivity of the domino reactions was readily controlled by switching the solvent and catalyst. Asymmetric syntheses and an oxidative carbocyclization‐borylation reaction have also been developed based on the heterogeneous palladium catalyst.
Bright and Stable NIR‐II J‐Aggregated AIE Dibodipy‐Based Fluorescent Probe for Dynamic In Vivo Bioimaging
Authors: Zhang Qisong , Yu Peng , Fan Yong , Sun Caixia , He Haisheng , Liu Xuan , Lu Lingfei , Zhao Mengyao , Zhang Hongxin , Zhang Fan
Published: September 2020

Organic dyes emitting in the second near‐infrared (NIR‐II, 900–1700 nm) window, with high molar extinction coefficients (MEC) and quantum yields (QY) in aqueous, are essential for in vivo bioimaging and biosensing. In this work, we developed a dibodipy‐based aggregation‐induced emission (AIE) fluorescent probe, THPP, to meet this aim. THPP exhibits a high MEC and has intensified absorption and emission in J‐aggregated state, which significantly enhance the fluorescence intensity (≈55 folds) and extend the maximal absorption/emission wavelengths to 970/1010 nm in NIR‐II region. Based on the bright THPP, imaging with a high frame rate (34 frames per second) at a deep “valid penetration depth” up to 6 mm can be achieved. This enabled simultaneous and dynamic imaging of vasculatures and deep tissues. Besides, we succeeded in monitoring the respiratory rate of acute‐lung‐injury mice and tracing the collateral circulation process with a high frame rate.
High Ammonia Uptake of a Metal–Organic Framework Adsorbent in a Wide Pressure Range
Authors: Kim Dae Won , Kang Dong Won , Kang Minjung , Lee Jung‐Hoon , Choe Jong Hyeak , Chae Yun Seok , Choi Doo San , Yun Hongryeol , Hong Chang Seop
Published: September 2020

Although numerous porous adsorbents have been investigated for NH3capture applications, these materials often exhibit insufficient NH3uptake, low NH3affinity at the ppm level, and poor chemical stability against wet NH3conditions. The NH3capture properties of M2(dobpdc) complexes (M=Mg2+, Mn2+, Co2+, Ni2+, and Zn2+; dobpdc4−=4,4‐dioxidobiphenyl‐3,3‐dicarboxylate) that contain open metal sites is presented. The NH3uptake of Mg2(dobpdc) at 298 K was 23.9 mmol g−1at 1 bar and 8.25 mmol g−1at 570 ppm, which are record high capacities at both pressures among existing porous adsorbents. The structural stability of Mg2(dobpdc) upon exposure to wet NH3was superior to that of the other M2(dobpdc) and the frameworks tested. Overall, these results demonstrate that Mg2(dobpdc) is a recyclable compound that exhibits significant NH3affinity and capacity, making it a promising candidate for real‐world NH3‐capture applications.
Telmisartan detection by UV spectrophotometry in mice drinking water
Authors: Gonçalves Leidyanne Ferreira , Fernandes‐Santos Caroline
Published: September 2020

Animal models are often used to test the safety and efficacy of drugs in cell culture and body systems. Several researchers deliver drugs to rodents in drinking water, although it has some limitations. For instance, drug stability, water consumption, and body mass fluctuation may change drug dose. Thus, we investigated telmisartan (TEL) stability in mice drinking water by UV spectrophotometry, and if water intake and body mass were fluctuated then it changes the predicted drug dose. The results showed that UV spectrophotometry could detect TEL at the wavelength of 300 nm, and the concentration curve was set between 1.25 and 60 µg/mL. Also, it remained stable in mice drinking water for 7 days at the predicted concentration. Mice gained weight after 8 weeks on a high‐fat high‐sucrose diet, and it was reduced by TEL 5 mg/kg/day after 3 weeks. Although water intake remained stable, not adjusting the TEL concentration weekly by body mass would lead to higher consumption of TEL by mice. In conclusion, we demonstrated that body mass and water intake fluctuations significantly change the amount of drug that the animal receives, which would add bias to the experiment. TEL remains stable for at least 7 days in wrapped mice water bottles in the animal care facility, and UV spectrophotometry proved to be a simple and low‐cost method to detect TEL in mice drinking water.
Pd on magnetic hybrid of halloysite and POSS‐containing copolymer: An efficient catalyst for dye reduction
Authors: Sadjadi Samahe , Koohestani Fatemeh , Atai Mohammad
Published: September 2020

A novel catalytic nanocomposite, MNPs/Hal‐POSS‐HEMA‐Pd, composed of halloysite nanoclay and polyhedral oligomeric silsesquioxane is reported. To synthesize the catalyst, magnetic halloysite was vinyl functionalized and then polymerized with 2‐hydroxyethyl methacrylate and methacrylate polyhedral oligomeric silsesquioxane. Afterwards, the latter was palladated to furnish a heterogeneous catalyst with use for catalyzing the reductive degradation of organic dyes, Rhodamine B, and methyl orange with NaBH4. The kinetic and thermodynamic parameters of both reactions were estimated. The results asserted that low content of the catalyst could catalyze the dye reduction reactions to furnish hydrogenated product in quantitative conversion in a very short reaction times (1 min). It is assumed that both halloysite and polyhedral oligomeric silsesquioxane can contribute to the anchoring of Pd nanoparticles. On the other hand, the polymeric network around halloysite can furnish a microenvironment for bringing dyes in the vicinity of active sites. Moreover, unique tubular morphology of halloysite can effectively improve dye adsorption and consequently enhance dye reduction. Additionally, the study of the recyclability of the catalyst approved that it could be magnetically recovered and reused for ten successive reaction runs with trivial leach of Pd (2 wt.%) and decrement of the catalytic activity.
SiC whiskers‐reinforced polyimide aerogel composites with robust compressive properties and efficient thermal insulation performance
Authors: Hou Xianbo , Li Yan , Luo Xiaoguang , Zhang Rubing
Published: September 2020

Polyimide (PI) aerogels enable promising application in many fields but are always inhibited by their weak resistance to high temperature and low mechanical properties. Herein, novel PI aerogel composites with efficient heat insulation and high compressive performance are prepared by introducing Silicon carbide whiskers (SiCw) as reinforcement. The SiCw in aerogel function as shrinkage inhibitor and high temperature stabilizer. The addition of SiCw exhibits obvious enhancement and toughening effect, the compressive strength of the PI aerogel composites increases from 1.09 to 1.96 MPa. These PI aerogel composites also show enhanced high temperature stability. The as‐prepared PI aerogel composites possess integrated properties of high‐temperature resistance, low thermal conductivity, and high compressive strength, which can be the candidate for the application in aerospace.
Robust mosaicking of maize fields from aerial imagery
Authors: Aktar Rumana , Kharismawati Dewi Endah , Palaniappan Kannappan , Aliakbarpour Hadi , Bunyak Filiz , Stapleton Ann E. , Kazic Toni
Published: September 2020

Premise

Aerial imagery from small unmanned aerial vehicle systems is a promising approach for high‐throughput phenotyping and precision agriculture. A key requirement for both applications is to create a field‐scale mosaic of the aerial imagery sequence so that the same features are in registration, a very challenging problem for crop imagery.

Methods

We have developed an improved mosaicking pipeline, Video Mosaicking and summariZation (VMZ), which uses a novel two‐dimensional mosaicking algorithm that minimizes errors in estimating the transformations between successive frames during registration. The VMZ pipeline uses only the imagery, rather than relying on vehicle telemetry, ground control points, or global positioning system data, to estimate the frame‐to‐frame homographies. It exploits the spatiotemporal ordering of the image frames to reduce the computational complexity of finding corresponding features between frames using feature descriptors. We compared the performance of VMZ to a standard two‐dimensional mosaicking algorithm (AutoStitch) by mosaicking imagery of two maize (Zea mays) research nurseries freely flown with a variety of trajectories.

Results

The VMZ pipeline produces superior mosaics faster. Using the speeded up robust features (SURF) descriptor, VMZ produces the highest‐quality mosaics.

Discussion

Our results demonstrate the value of VMZ for the future automated extraction of plant phenotypes and dynamic scouting for crop management.
Validation of a survey for measuring scientists' attitudes toward data reuse
Authors: Winkler Christa E. , Berenbon Rebecca Fay
Published: September 2020

This study investigated the validity of a survey measuring scientists' attitudes toward data reuse. Rasch analysis was used to examine the psychometric properties of the survey. Structural equation modeling was subsequently used to examine the validity of hypothesized relationships among the constructs measured by the survey. Overall, findings supported validity of the existing measure for use among researchers across academic disciplines. Recommendations for further refinement of the survey include the addition of new items to improve reliability of measurement. Additionally, implications for organizational practice are discussed, including the importance of fostering individual researchers' perceived usefulness of secondary data, as well as providing access to data repositories and organizational resources for data reuse.
Synthesis of 4‐Acylchromene via Highly Chemoselective Iodine‐Catalyzed Cyclization of Alkynylarylether Dimethylacetals
Authors: Rodphon Warabhorn , Thongsornkleeb Charnsak , Tummatorn Jumreang , Ruchirawat Somsak
Published: September 2020

4‐Acylchromene is an important core structure found in bioactive natural products and bioactive synthetic compounds. Moreover, this core structure is frequently used as a key precursor for the synthesis of more complex molecules. In this work, we discovered that a combination of acetone and catalytic I2 could lead to selective activation of acetal in alkynylarylether dimethylacetal substrates while alkyne moiety remained intact. This activation of acetal led to the generation of oxonium ion intermediate which triggered intramolecular cyclization and elimination of methanol to provide the desired 4‐acylchromene as the sole product in up to 95% yield. Moreover, this method could be applied in a broad range of substrates under a mild and metal‐free catalytic conditions for the synthesis of 4‐acylchromene derivatives.
Enhancement of Structural, Electrochemical, and Thermal Properties of Ni‐Rich LiNi0.85Co0.1Mn0.05O2 Cathode Materials for Li‐Ion Batteries by Al and Ti Doping
Authors: Levartovsky Yehonatan , Wu Xiaohan , Erk Christoph , Maiti Sandipan , Grinblat Judith , Talianker Michael , Aurbach Doron
Published: September 2020

Ni‐rich layered oxides LiNi1‐x‐yCoxMnyO2 (1−x−y>0.5) are promising cathode materials for the new generation of Li‐ion batteries suitable for electro‐mobility due to their high energy density, good rate capability, and relatively low cost. However, their main drawback is poor cycling performance, particularly at elevated temperatures. In this research, it is demonstrated how doping with Al and Ti, using straightforward solid‐state mixing synthesis, can dramatically enhance the structural, electrochemical, and thermal properties of LiNi0.85Co0.1Mn0.05O2 (NCM85). The capacity retention of Al‐doped and Ti‐doped cathodes after 100 cycles at 100 % DOD at 1 C and 45 °C using standard electrolyte solutions could reach nearly 99 % and 78 %, respectively, while the capacity retention of the undoped material was less than 74 % in similar experiments. Doping with Al and Ti facilitates the Li intercalation processes and reduces voltage hysteresis. Structural study of the cycled cathodes shows that doping with Al, and to a smaller extent with Ti, reduces the formation of cracks in the particles of the cathode materials upon cycling, consequently reducing degradation. Thermal studies show that doping with Al or Ti improves the thermal stability of these cathode materials. Highly interesting is the correlation between the morphology and thermal stability, impedance properties and the electrochemical characteristics as a function of doping.
Genetic manipulation of non‐solvent‐producing microbial species for effective butanol production
Authors: Lv Yang , Jiang Yujia , Peng Wenfang , Fang Yan , Dong Weiliang , Zhou Jie , Zhang Wenming , Xin Fengxue , Jiang Min
Published: September 2020

Butanol is widely used as an important bulk chemical and is a potential biofuel. The depletion of fossil fuels and advances in synthetic biotechnology have led to renewed interest in the biological production of butanol. Solventogenic Clostridium was commonly used to produce butanol through traditional acetone‐butanol‐ethanol (ABE) fermentation. However, its relatively slow growth rate, low butanol tolerance, and poor production efficiency have hindered the further application of this procedure. Recently, other promising industrial hosts, including Escherichia coli, Saccharomyces cerevisiae, and Clostridium tyrobutyricum, have been studied for potential use in the production of butanol. This review comprehensively summarizes the advantages and challenges of different non‐solvent strains for butanol production to identify better the ideal non‐solvent hosts for butanol production. Strategies to further increase butanol production are also proposed. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd.
Perirenal fat thickness as a predictor of postoperative complications after laparoscopic distal gastrectomy for gastric cancer
Authors: Eto K , Ida S , Ohashi T , Kumagai K , Nunobe S , Ohashi M , Sano T , Hiki N
Published: September 2020

Background

Laparoscopic distal gastrectomy is used widely in surgery for gastric cancer. Excess visceral fat can limit the ability to dissect the suprapancreatic region, potentially increasing the risk of local complications, particularly pancreatic fistula. This study evaluated perirenal fat thickness as a surrogate for visceral fat to see whether this was related to complications after laparoscopic distal gastrectomy.

Methods

Perirenal fat thickness was measured dorsal to the left kidney as an indicator of visceral fat in patients with gastric cancer who underwent laparoscopic distal gastrectomy. Patients were divided into two groups: those with and those without complications. The relationship between perirenal fat thickness and postoperative complications was evaluated.

Results

The optimal cut-off value for predicting morbidity using adipose tissue thickness was 10·7 mm; a distance equal to or greater than this was considered a positive perirenal fat thickness sign (PTS). A positive PTS showed a significant correlation with visceral fat area. Multivariable analysis found that a positive PTS was an independent risk factor for complications (hazard ratio 4·42, 95 per cent c.i. 2·31 to 8·86; P < 0·001).

Conclusion

Perirenal fat thickness as an indicator of visceral fat was an independent predictor of postoperative complications after laparoscopic distal gastrectomy for gastric cancer.
CUREing cancer: Development and implementation of a molecular biology‐focused course‐based undergraduate research experience using a cancer cell culture model
Authors: Guttilla Reed Irene K.
Published: September 2020

Many students in the sciences are interested in exploring research opportunities; however, the one‐on‐one faculty mentorship model often lacks the ability to supervise large numbers of students. An alternative mechanism for exposing undergraduate students to the research process is participation in a Course‐based Undergraduate Research Experience (CURE). CUREs promote inclusivity in research, and provide structure for both students and faculty while engaging students in scientific discovery. This study describes a model for a CURE in cancer biology, and reports student outcomes. Students utilized bioinformatics to predict targets genes of miR‐100, a microRNA that is differentially expressed in a cell culture model of breast cancer metastasis. Students were required to engage with primary literature to write a grant proposal for their target gene, and then were trained to perform basic molecular biology techniques to test their individual hypotheses. Additionally, the course integrated opportunities to troubleshoot experiments and present data to the group, and culminated in a publication style scientific report discussing the results of their individual research project. Students reported significantly increased confidence in executing various molecular biology techniques and research‐related skills based on pre‐ and post‐assessment surveys. Student feedback also indicated that they gained an understanding of primary literature, experimental design, and scientific writing as a result of the course. This study supports that CUREs can be an effective pedagogy for not only engaging larger groups of students in research, but also improving their confidence and skill set in the laboratory.
Effects of lixisenatide treatment on mild cachexia and related metabolic abnormalities in Walker‐256 tumour‐bearing rats
Authors: Quintilhano Débora L. , Miksza Daniele R. , Biazi Giuliana R. , Frasson‐Uemura Isabele G. , Graciano Maria Fernanda R. , Mazzuco Tânia L. , Carpinelli Ângelo R. , de Souza Helenir M. , Bertolini Gisele L.
Published: September 2020

Lixisenatide, a glucagon‐like peptide‐1 (GLP‐1) receptor agonist, is used in the treatment of type 2 diabetes mellitus (T2DM). It increases insulin (INS) secretion and can decrease INS resistance, improving metabolic disorders in this disease. However, its effects on metabolic disturbances in cancer‐bearing, which also exhibit decreased INS secretion and INS resistance, changes that may contribute to weight loss (cachexia), have not yet been evaluated. The purpose of this study was to investigate the lixisenatide treatment effects on mild cachexia and related metabolic abnormalities in Walker‐256 tumour‐bearing rats. Lixisenatide (50 μg kg−1, SC) was administered once daily, for 6 days, after inoculation of Walker‐256 tumour cells. Acute lixisenatide treatment did not improve hypoinsulinemia, INS secretion and INS resistance of tumour‐bearing rats. It also did not prevent the reduced glucose and increased triacylglycerol and lactate in the blood and nor the loss of retroperitoneal and epididymal fat of these animals. However, acute lixisenatide treatment accentuated the body mass loss of tumour‐bearing rats. Therefore, lixisenatide, unlike T2DM, does not improve hypoinsulinemia and INS resistance associated with cancer, evidencing that it does not have the same beneficial effects in these two diseases. In addition, lixisenatide aggravated weight loss of tumour‐bearing rats, suggesting that its use for treatment of T2DM patients with cancer should be avoided.

Significance of the study

Lixisenatide increases insulin secretion and appears to reduce insulin resistance in T2DM. However, lixisenatide treatment does not improve hypoinsulinemia and insulin resistance associated with cancer, as it does in T2DM, and aggravated weight loss, suggesting that its use for treatment of T2DM patients with cancer should be avoided.
Simultaneous Visualization of Wet Cells and Nanostructured Biomaterials in SEM using Ionic Liquids
Authors: Lee Bryan E. J. , DiCecco Liza‐Anastasia , Exir Hourieh , Weck Arnaud , Sask Kyla N. , Grandfield Kathryn
Published: September 2020

This work presents a successful methodology to image mammalian cells adhered to nanostructured titanium by using scanning electron microscopy (SEM) operating in low‐vacuum mode following ionic liquid treatment. Human osteoblast‐like Saos‐2 cells were treated with a room‐temperature ionic liquid, 1‐ethyl‐3‐methylimidazolium tetrafluoroborate, and subsequently imaged on titanium by SEM. Titanium substrates were modified to create laser‐induced periodic surface structures (LIPSS) for visualization at the submicron scale. By using a combination of fluorescence‐based cell metabolism along with light microscopy and SEM image analysis, the shape and location of irradiated cells were confirmed to be unchanged after multiple irradiation sessions; the viability of minimally irradiated cells was also unaltered. The wet imaging conditions combined with a rapid facile protocol using ionic liquid allows this technique to fulfill a niche in examining cellular behavior on biomaterials with submicron surface features. The demonstrated method to track observed cell adhesion to submicron surface features by SEM has great implications for understanding cell migration on nanostructured surfaces as well as the exploration of simpler SEM preparation methods for cellular imaging.
Activation of Protease and Luciferase Using Engineered Nostoc punctiforme PCC73102 DnaE Intein with Altered Split Position
Authors: Kawase Misaki , Fujioka Meiko , Takahashi Tsuyoshi
Published: September 2020

Inteins, self‐catalytic enzymes, have been widely used in the field of protein engineering and chemical biology. Here, Nostoc punctiforme PCC73102 (Npu) DnaE intein was engineered to have an altered split position. An 11‐residue N‐intein of DnaE in which Gly and Asp were substituted for Tyr4 and Glu5, respectively, was designed, and the active C‐intein variants were acquired by a GFP fluorescence‐based screening. The designed N‐intein and the obtained active C‐intein variants were used to construct a turn‐on system for enzyme activities such as human immunodeficiency 1 protease and NanoLuc luciferase. Based on the NanoLuc‐intein fusion, we developed two intein pairs, each of which is capable of reacting preferentially, by interchanging the charged amino acids on N‐ and C‐inteins. The specific splicing reactions were easily monitored and discriminated by bioluminescence resonance energy transfer (BRET).