bluuebunny/crossref_metadata_2025 huggingface dataset:
Ground energy level transition for two-body interacting Fermionic system with spin-orbit coupling and Zeeman interaction
Authors: Chen Xing , Xue Xiao-Bo , Zhang Sheng-Kang , Ma Yu-Quan , Fei Peng , Jiang Yuan , Ge Jun ,   Science and Technology on Metrology and Calibration Laboratory, Beijing Institute of Radio Metrology and Measurement, Beijing 100854, China,   Department of Science, Beijing Information Science & Technology University, Beijing 100192, China
Published: April 2021

Experimental realization of artificial gauge field has made it possible to simulate important models with electromagnetic field or spin-orbit interaction in condensed matter physics, which opens a new avenue to engineer novel quantum states and phenomena. The spin-orbit coupled system reveals many significant phenomena in condensed matter physics, such as quantum spin Hall effect, topological insulator and topological superconductor. The combined effect of Zeeman interaction and spin-orbit coupling leads to a nontrivial topological phase. The analytic solution of few-body system provides an in-depth insight into the physical phenomena, which has been studied extensively. Through the analytic study of two-body physics, we show new quantum phenomena for various gauge field parameters. We investigate the two-body interacting fermionic gas with spin-orbit coupling and Zeeman interaction in a ring trap. Through the plane wave expansion method, two-body fermionic system is solved analytically. In the absence of Zeeman interaction, the total momentum of the ground state is zero. With the increase of Zeeman interaction, an energy level crossing occurs between the lowest energy levels for different total momentum spaces and the ground state changes from zero total momentum space to non-zero total momentum space. Considering the Zeeman interaction, the total momentum of the ground state changes from zero to finite value. The single particle analysis shows that the ground energy level transition is induced by Zeeman energy level splitting. The momentum distributions of the ground state are given to provide an intuitive physical picture. This work can be further extended to the exploration of the heteroatom system, lattice system and higher spin system.
Review on laser-driven high-energy polarized electron and positron beams and γ-rays
Authors: Sun Ting , Wang Yu , Guo Ren-Tong , Lu Zhi-Wei , Li Jian-Xing ,   MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Science, Xi’an Jiaotong University, Xi’an 710049, China
Published: April 2021

High-energy spin-polarized electron and positron beams and γ-rays have plenty of significant applications in high-energy, laboratory astro- and nuclear physics, and the efficient generation of such polarized beams attracts a broad research interest. Recently, with the rapid development of ultrashort ultraintense laser pulse technology, the modern laser pulses can achieve a peak intensity in a range of 1022—\begin{document}$10^{23}$\end{document} W/cm2 with a pulse duration of tens of femtoseconds. The interaction mechanisms between such a laser pulse and matter have been spanned from linear regime to nonlinear regime due to multiphoton absorbtion, such as nonlinear Compton scattering and Breit-Wheeler pair production. Employing spin-dependent nonlinear Compton scattering and multiphoton Breit-Wheeler scattering in laser-matter interaction paves a new way for generating the high-polarized high-density high-energy electron and positron beams and γ-rays with tens of femtoseconds in pulse duration. This article briefly reviews the research progress of polarized electron and positron beams and γ-rays generated by laser-matter interaction, and also introduces the principles and main conclusions.
Transcriptional profile in rat muscle: down-regulation networks in acute strenuous exercise
Authors: Felipe Stela Mirla da Silva , Freitas Raquel Martins de , Penha Emanuel Diego dos Santos , Pacheco Christina , Martins Danilo Lopes , Alves Juliana Osório , Soares Paula Matias , Loureiro Adriano César Carneiro , Lima Tanes , Silveira Leonardo R. , Ferraz Alex Soares Marreiros , Souza Jorge Estefano Santana de , Leal-Cardoso Jose Henrique , Carvalho Denise P. , Ceccatto Vania Marilande
Published: April 2021

Background

Physical exercise is a health promotion factor regulating gene expression and causing changes in phenotype, varying according to exercise type and intensity. Acute strenuous exercise in sedentary individuals appears to induce different transcriptional networks in response to stress caused by exercise. The objective of this research was to investigate the transcriptional profile of strenuous experimental exercise.

Methodology

RNA-Seq was performed with Rattus norvegicus soleus muscle, submitted to strenuous physical exercise on a treadmill with an initial velocity of 0.5 km/h and increments of 0.2 km/h at every 3 min until animal exhaustion. Twenty four hours post-physical exercise, RNA-seq protocols were performed with coverage of 30 million reads per sample, 100 pb read length, paired-end, with a list of counts totaling 12816 genes.

Results

Eighty differentially expressed genes (61 down-regulated and 19 up-regulated) were obtained. Reactome and KEGG database searches revealed the most significant pathways, for down-regulated gene set, were: PI3K-Akt signaling pathway, RAF-MAP kinase, P2Y receptors and Signaling by Erbb2. Results suggest PI3K-AKT pathway inactivation by Hbegf, Fgf1 and Fgr3 receptor regulation, leading to inhibition of cell proliferation and increased apoptosis. Cell signaling transcription networks were found in transcriptome. Results suggest some metabolic pathways which indicate the conditioning situation of strenuous exercise induced genes encoding apoptotic and autophagy factors, indicating cellular stress.

Conclusion

Down-regulated networks showed cell transduction and signaling pathways, with possible inhibition of cellular proliferation and cell degeneration. These findings reveal transitory and dynamic process in cell signaling transcription networks in skeletal muscle after acute strenuous exercise.
Overexpression of a Rosa rugosa Thunb. NUDX gene enhances biosynthesis of scent volatiles in petunia
Authors: Sheng Lixia , Zang Shu , Wang Jianwen , Wei Tiantian , Xu Yong , Feng Liguo
Published: April 2021

Rosa rugosa is an important natural perfume plant in China. Rose essential oil is known as ‘liquid gold’ and has high economic and health values. Monoterpenes are the main fragrant components of R. rugosa flower and essential oil. In this study, a member of the hydrolase gene family RrNUDX1 was cloned from Chinese traditional R. rugosa ‘Tang Hong’. Combined analysis of RrNUDX1 gene expression and the aroma components in different development stages and different parts of flower organ, we found that the main aroma component content was consistent with the gene expression pattern. The RrNUDX1 overexpressed Petunia hybrida was acquired via Agrobacterium-mediated genetic transformation systems. The blades of the transgenic petunias became wider and its growth vigor became strong with stronger fragrance. Gas chromatography with mass spectrometry analysis showed that the contents of the main aroma components of the transgenic petunias including methyl benzoate significantly increased. These findings indicate that the RrNUDX1 gene plays a role in enhancing the fragrance of petunia flowers, and they could lay an important foundation for the homeotic transformation of RrNUDX1 in R. rugosa for cultivating new R. rugosa varieties of high-yield and -quality essential oil.
Next-Generation Sequence: A Review on Metagenomic Approach to Discovery of Novel Enzymes from the Soil Environment
Authors: Sedjoah Rita-Cindy Aye-Ayire
Published: April 2021

Next-generation sequencing (NGS) makes a large mass of sequences. As a technology that allows the sequence of deoxyribonucleic acid (DNA) molecules larger than one million base pairs, it has been applied in the food research and medical fields. In the food sector, NGS has been used in food safety for the detection of species authenticity of food products and for mostly discovering novel industrial enzymes. The soil ecosystem houses a great number of non-culturable microbes thus novels enzymes can still be discovered to date. The conventional methods used in enzyme discovery have less chances to identify novel gene clusters and bioactivities.  Therefore, there is a dire need for high-throughput technology, together with advanced bioinformatics for the search of novel enzymes or biocatalysts from soil metagenomes. This review article thus gives a summary of the progress in the application of next-generation sequencing in the identification and characterization of novel enzymes with a special focus on enzymes from the soil environment.
Exploring the Benefit of Blogs Dependency for Assessing Students’ Intellectual Achievement
Authors: Adeleke Imran Ademola , Muraina Ismail Olaniyi
Published: April 2021

Blogs stand out among many social media that allows teacher and students to maintain a running dialogue in various aspect of the teaching and learning process. It comes in form of thoughts, ideas, tests, short-works/homework and assignment to enhance interactivity between the teacher’s knowledge base and students’ comments and reflections. This paper promotes the use of blogs in assessing students’ intellectuals while comparing the use of blogging for assessment as well as the use of traditional assessment. The study stresses scoring on paper versus scoring on blogs, students that we're able to complete their visitation of the blogs were noted to enjoy and benefit greatly compare to those that could not finish theirs and whether the performance of male bloggers may be different from that of female bloggers. 45 students involved in this study from among degree students of Achievers University. The research study was done within a semester. The achievement test was the major instrument used to collect data from the same students that were exposed to two different tests (Paper Test/Traditional Test and Blogging Test) after proper classroom teaching. The results got were analyzed using mean, SD and T-test statistics. From the findings, it was succinctly shown that the scores of students engaged in blogs far better than when they initially tested traditionally. In the same trend, those students that completed their test on blogs demonstrated high performance than their counterparts that could not. Further, the results also made it crystal clear that students were distributed equally on blogging regardless of their gender differences. The findings from the interview conducted established the fact that the use of a blog for assessment saves student time, the distance for learning and having quick result as feedback. The student has a high interest in the use of a blog for academic purposes rather than only the social affairs of the student. The paper contributes to the existing knowledge by turning blogs as social media into academic media that can foster the academic achievement of students and can also be used to assess students better than traditional assessment.
Evaluation of the Toxicological Profile of Commiphora opobalsamum in Wister Rats for Its Safety and Rational Use
Authors: Ahmad Mai A. Alim A. Sattar , Al-Salmi Akram A. , Kamel Fatemah O. , Khan Lateef M.
Published: April 2021

Aim: To study acute and chronic toxicity profile of Commiphora opobalsamum (CO) in rats.

Methods: Acute oral lethal effect and single oral dose toxicity of CO was determined in rats by comparison with standard control. In contrast repeated dose oral toxicity in rats were performed in four groups of rats, CO was orally administered to three groups of rats in graded doses (250, 500 and 1000 mg/kg/day) once daily for 14 daysVs standard control. The sub-acute toxicity of CO was observed on hematological, coagulation and biochemical parameters.

Results: Acute oral lethal dose of CO in rats was demonstrated to be safe and higher than the tested dose i.e., 2000 mg/kg, moreover, single oral dose toxicity revealed no symptoms of toxicity. Furthermore, sub-acute toxicological effect on hematological analysis of CO rats groups treated withgraded dosed after 14 days treatment revealed insignificant decrease in complete blood count (CBC)in contrast with the control group (p>0.05) additionally the biochemical parameters includedanalysis of urea, creatinine, glucose; lipid profile and thyroid function markers fairly demonstrated insignificant differences utilizing the same methodology.

Conclusion: Our current explorative study strongly substantiates that the CO extract have no significantoral toxicity in rats and even the results of 14 days oral treatment indicated that there were no obvious toxic effects at the dosage of 1000 mg/kg/day. The comprehensive sub-acute toxicological effect of CO extracts on hematological and coagulation parameters and biochemical parameters included analysis of urea, creatinine, glucose; lipid profile and thyroid function markers fairly demonstrated no significant harmful outcome even after 14 days treatment with CO.
Serum creatine kinase and creatinine in adult spinal muscular atrophy under nusinersen treatment
Authors: Freigang Maren , Wurster Claudia D. , Hagenacker Tim , Stolte Benjamin , Weiler Markus , Kamm Christoph , Schreiber‐Katz Olivia , Osmanovic Alma , Petri Susanne , Kowski Alexander , Meyer Thomas , Koch Jan C. , Cordts Isabell , Deschauer Marcus , Lingor Paul , Aust Elisa , Petzold Daniel , Ludolph Albert C. , Falkenburger Björn , Hermann Andreas , Günther René
Published: April 2021

Objective

To determine whether serum creatine kinase activity (CK) and serum creatinine concentration (Crn) are prognostic and predictive biomarkers for disease severity, disease progression, and nusinersen treatment effects in adult patients with 5q‐associated spinal muscular atrophy (SMA).

Methods

Within this retrospective, multicenter observational study in 206 adult patients with SMA, we determined clinical subtypes (SMA types, ambulatory ability) and repeatedly measured CK and Crn and examined disease severity scores (Hammersmith Functional Motor Scale Expanded, Revised Upper Limb Module, and revised Amyotrophic Lateral Sclerosis Functional Rating Scale). Patients were followed under nusinersen treatment for 18 months.

Results

CK and Crn differed between clinical subtypes and correlated strongly with disease severity scores (e.g., for Hammersmith Functional Motor Scale Expanded: (CK)ρ = 0.786/ (Crn)ρ = 0.558). During the 18 months of nusinersen treatment, CK decreased (∆CK = −17.56%,p < 0.0001), whereas Crn slightly increased (∆Crn = +4.75%,p < 0.05).

Interpretation

Serum creatine kinase activity and serum creatinine concentration reflect disease severity of spinal muscular atrophy and are promising biomarkers to assess patients with spinal muscular atrophy during disease course and to predict treatment response. The decrease of creatine kinase activity, combined with the tendency of creatinine concentration to increase during nusinersen treatment, suggests reduced muscle mass wasting with improved muscle energy metabolism.
Engineering Aggregation‐Resistant MXene Nanosheets As Highly Conductive and Stable Inks for All‐Printed Electronics
Authors: Tang Xiaowu , Murali G. , Lee Hyungjin , Park Seongmin , Lee Seongeun , Oh Sun Moo , Lee Jihoon , Ko Tae Yun , Koo Chong Min , Jeong Yong Jin , An Tae Kyu , In Insik , Kim Se Hyun
Published: April 2021

MXenes are interesting 2D materials that have been considered as attractive frontier materials for potential applications in the fields of energy and electronic devices due to their excellent optoelectronic properties including metallic conductivity and high optical transparency. However, it is still challenging to achieve compatibility for the as‐synthesized MXene nanosheets with simple solution‐deposition and patterning processes because of their limited solubility in many solvents. Here, a promising strategy is developed for obtaining alcohol‐dispersible MXene nanosheets suitable for all‐printed electronics while enhancing their electrical conductivity. This strategy includes a trifluoroacetic acid treatment—applied in order to contribute to the modification of intercalants between the MXene nanosheets—and achieves long‐term dispersion of the MXene in alcoholic media and balanced jetting conditions during the electrohydrodynamic printing process. Furthermore, the high conductivity levels of the treated MXenes allow their printed patterns to be applied as gate and source/drain electrodes in all‐printed logic circuits, displaying good and robust operation in transistors, inverters, and NAND, and NOR logic gates. This study provides a promising approach for modifying MXene nanosheets with the purpose of achieving desirable properties suitable for large‐area printing processes, suggesting the feasibility of using MXene in practical applications involving all‐printed electronics.
Nanoagent‐Promoted Mild‐Temperature Photothermal Therapy for Cancer Treatment
Authors: Gao Ge , Sun Xianbao , Liang Gaolin
Published: April 2021

Photothermal therapy (PTT), which utilizes near‐infrared light‐absorbing agents to ablate tumor, has emerged as a highly promising anticancer strategy and received intensive clinical trials in recent years. Mild‐temperature PTT, which circumvents the limitations of conventional PTT (e.g., thermoresistance and adverse effects), is emerging and shows great potential in the forthcoming clinical applications. However, mild‐temperature PTT without adjuvant therapy is not able to completely eradicate tumors because its therapeutic efficacy is dramatically impaired by its inferior heat intensity. As a result, strategies capable of enhancing the anticancer efficacy of mild‐temperature PTT are urgently necessitated, which mainly rely on on‐demand fabrication of functionalized nanoagents. In this review, the strategies of nanoagent‐promoted mild‐temperature PTT are highlighted. Furthermore, challenges and opportunities in this field are rationally proposed, and hopefully people can be encouraged by this promising anticancer therapy.
Optically and Electrocatalytically Decoupled Si Photocathodes with a Porous Carbon Nitride Catalyst for Nitrogen Reduction with Over 61.8% Faradaic Efficiency
Authors: Peramaiah Karthik , Ramalingam Vinoth , Fu Hui‐Chun , Alsabban Merfat M. , Ahmad Rafia , Cavallo Luigi , Tung Vincent , Huang Kuo‐Wei , He Jr‐Hau
Published: April 2021

The photoelectrochemical (PEC) approach is attractive as a promising route for the nitrogen reduction reaction (NRR) toward ammonia (NH3) synthesis. However, the challenges in synergistic management of optical, electrical, and catalytic properties have limited the efficiency of PEC NRR devices. Herein, to enhance light‐harvesting, carrier separation/transport, and the catalytic reactions, a concept of decoupling light‐harvesting and electrocatalysis by employing a cascade n+np+‐Si photocathode is implemented. Such a decoupling design not only abolishes the parasitic light blocking but also concurrently improves the optical and electrical properties of the n+np+‐Si photocathode without compromising the efficiency. Experimental and density functional theory studies reveal that the porous architecture and N‐vacancies promote N2 adsorption of the Au/porous carbon nitride (PCN) catalyst. Impressively, an n+np+‐Si photocathode integrating the Au/PCN catalyst exhibits an outstanding PEC NRR performance with maximum Faradaic efficiency (FE) of 61.8% and NH3 production yield of 13.8 µg h–1 cm–2 at −0.10 V versus reversible hydrogen electrode (RHE), which is the highest FE at low applied potential ever reported for the PEC NRR.
Transition‐Metal‐Free Synthesis of Unsymmetrical Disulfides via Three‐Component Reaction of Thiosulfonates, Thiourea and Alkyl halides
Authors: Wang Dungai , He Quan , Shi Keqiang , Xiong Mingteng , Zhou Yifeng , Pan Yuanjiang
Published: April 2021

A transition‐metal‐free approach to synthesize unsymmetrical disulfides is reported that relies on a K2CO3‐promoted one‐pot reaction of thiosulfonates, thiourea and alkyl halides under mild conditions. The protocol tolerates a wide range of substrates, leading to various types of unsymmetrical disulfides in moderate to excellent yields. More importantly, the late‐stage modification of natural products and drug molecules was also achieved.

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Synthesis of N‐Fused Indolines via Copper (II)‐Catalyzed Dearomatizing Cyclization of Indoles
Authors: Zhang Jingyu , Xia Wei , Huda Saskia , Ward Jas S. , Rissanen Kari , Albrecht Markus
Published: April 2021

Herein, a copper(II)‐catalyzed dearomative cyclization amination of N‐(2‐aminobenzoyl) indoles is presented. Under mild reaction conditions, the cyclization proceeds to afford tetracyclic indolines by forming a new C−N bond in good yields. The tetracyclic 5a,6‐dihydroindolo[2,1‐b]quinazolin‐12(5H)‐ones are obtained in good to excellent yields (up to 99% yield) by using trifluoromethanesulfonic acid (TfOH) mediated N−Ts bond cleavage. The obtained compounds could be easily functionalized by simple synthetic methods.

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Recent Developments in the Cyclization of Alkynes and Nitrogen Compounds for the Synthesis of Indole Derivatives
Authors: Neto Jose S. S. , Zeni Gilson
Published: April 2021

This review is intended to highlight the most useful approaches for the synthesis of indole derivatives (azaindoles, carbazoles, carbolines, indazoles, 3H‐indoles, indolines, indolizines, isoindoles, and isoindolines), which were described by using transition‐metal catalyzed cyclization reactions of alkynes and nitrogen compounds. The methodologies carried out under metal‐free conditions will also be illustrated herein. This review will cover the data published mostly in the past decade.
Conformational and Substituent Effects on The Rehybridization of Boron in β‐Substituted Ethylboranes
Authors: Martins Francisco A. , Freitas Matheus P.
Published: April 2021

The chemistry of boron‐containing molecules pervades the study of biomolecules, new materials, organic synthesis, and beyond. In addition, the stereochemistry and rehybridization capability of boron in molecules influence the reactivity and selectivity of reactions. Therefore, conformational analysis and the study of substituent effects on the modulation of the sp2–sp3 character of boron in β‐substituted ethylboranes may be valuable for the rational design of compounds in which the empty pB orbital plays a central role in the reaction intermediate. Accordingly, we have quantum‐chemically studied the orbital interactions and bonding properties that govern the conformational behavior and boron hybridization in β‐substituted ethylboranes (substituents, X=H, CH3, F, Cl, NH2, PH2, OH, and SH). Conformations with an anti arrangement along the B−C−C−X path are generally preferred over syn and/or gauche conformations, while a B−H bond tends to eclipse with the C−C bond rather than with a less sterically hindered C−H bond. However, the s character of boron relative to the C−B bond strongly decreases in the syn conformation, where X can participate as an electron donor to the empty pB orbital. Indeed, such interaction makes the syn conformation of 2‐aminoethylborane the single stable conformer in the gas phase.
Midlife vascular risk factors and risk of incident dementia: Longitudinal cohort and Mendelian randomization analyses in the UK Biobank
Authors: Malik Rainer , Georgakis Marios K. , Neitzel Julia , Rannikmäe Kristiina , Ewers Michael , Seshadri Sudha , Sudlow Cathie L.M. , Dichgans Martin
Published: April 2021

Introduction

Midlife clustering of vascular risk factors has been associated with late‐life dementia, but causal effects of individual biological and lifestyle factors remain largely unknown.

Methods

Among 229,976 individuals (mean follow‐up 9 years), we explored whether midlife cardiovascular health measured by Life's Simple 7 (LS7) is associated with incident all‐cause dementia and whether the individual components of the score are causally associated with dementia.

Results

Adherence to the biological metrics of LS7 (blood pressure, cholesterol, glycemic status) was associated with lower incident dementia risk (hazard ratio = 0.93 per 1‐point increase, 95% confidence interval [CI; 0.89–0.96]). In contrast, there was no association between the composite LS7 score and the lifestyle subscore (smoking, body mass index, diet, physical activity) and incident dementia. In Mendelian randomization analyses, genetically elevated blood pressure was associated with higher risk of dementia (odds ratio = 1.31 per one‐standard deviation increase, 95% CI [1.05–1.60]).

Discussion

These findings underscore the importance of blood pressure control in midlife to mitigate dementia risk.
Na⋅⋅⋅B Bond in NaBH3−: Solving the Conundrum
Authors: Radenković Slavko , Shaik Sason S. , Braïda Benoît
Published: April 2021

Bonding in the recently synthesized NaBH3− cluster is investigated using the high level Valence Bond BOVB method. Contrary to earlier conclusions, the Na−B bond is found to be neither a genuine dative bond, nor a standard polar‐covalent bond at equilibrium. It is rather revealed as a split and polarized weakly coupled electron‐pair, which allows this cluster to be more effectively stabilized by a combination of (major) dipole‐dipole electrostatic interaction and (secondary) resonant one‐electron bonding mechanism. Our analysis of this unprecedented bonding situation extends to similar clusters, and the VB model unifies and articulates the previously published variegated views on this exotic “bond”.
Implications of Quenching‐to‐Dequenching Switch in Quantitative Cell Uptake and Biodistribution of Dye‐Labeled Nanoparticles
Authors: Yang Guangze , Liu Yun , Hui Yue , Tengjisi  , Chen Dong , Weitz David A. , Zhao Chun‐Xia
Published: April 2021

A general strategy to carry out cell uptake and biodistribution studies is to label nanoparticles (NPs) with a fluorescent dye. However, the comparative study of different dye‐loaded NPs remains difficult owing to uncontrolled dye quenching and de‐quenching. Here we compared two types of dye‐labeled NPs and demonstrated their distinct properties. NPs with dye molecules at a solid state suffer from dye quenching, so the dye release and/or NP degradation in biological environments leads to a several‐fold increase of fluorescence intensity despite the same amount of NPs, owing to the state switch from quenching to de‐quenching. In contrast, NPs with dye molecules at a soluble state exhibit no quenching effect. To standardize the comparative study, we propose two possible solutions: using lower dye loading or using medium analysis for quantifying cell uptake of NPs. This work provides valuable insights into selecting valid quantification methods for bio‐nano studies.
Freezing‐Assisted Conjugation of Unmodified Diblock DNA to Hydrogel Nanoparticles and Monoliths for DNA and Hg2+ Sensing
Authors: Li Yuqing , Gao Hang , Qi Zengyao , Huang Zhicheng , Ma Lingzi , Liu Juewen
Published: April 2021

Acrydite‐modified DNA is the most frequently used reagent to prepare DNA‐functionalized hydrogels. Herein, we show that unmodified penta‐adenine (A5) can reach up to 75 % conjugation efficiency in 8 h under a freezing polymerization condition in polyacrylamide hydrogels. DNA incorporation efficiency was reduced by forming duplex or other folded structures and by removing the freezing condition. By designing diblock DNA containing an A5 block, various functional DNA sequences were attached. Such hydrogels were designed for ultrasensitive DNA hybridization and Hg2+ detection, with detection limits of 50 pM and 10 nM, respectively, demonstrating the feasibility of using unmodified DNA to replace acrydite‐DNA. The same method worked for both gel nanoparticles and monoliths. This work revealed interesting reaction products by exploiting freezing and has provided a cost‐effective way to attach DNA to hydrogels.
Triptycene‐based Chiral Porous Polyimides for Enantioselective Membrane Separation
Authors: Zhang Qing‐Pu , Wang Zhen , Zhang Zhe‐Wen , Zhai Tian‐Long , Chen Jing‐Jing , Ma Hui , Tan Bien , Zhang Chun
Published: April 2021

Enantiomers of 2, 6‐diaminotriptycene (R, R‐1 and S, S‐1) are split by chiral‐phase HPLC and their absolute configurations are identified by single‐crystal X‐ray diffraction technology. Using the enantiomers as monomers, a couple of chiral porous polyimides (R‐FTPI and S‐FTPI) are prepared by polycondensation reactions and display good heat stability, high BET surface area and good solubility in organic solvents. Moreover, both of R‐FTPI and S‐FTPI can be cast into robust, free‐standing films suitable for enantioselective separation with symmetrical chiral selectivity.
Efficient (>20 %) and Stable All‐Inorganic Cesium Lead Triiodide Solar Cell Enabled by Thiocyanate Molten Salts
Authors: Yu Bingcheng , Shi Jiangjian , Tan Shan , Cui Yuqi , Zhao Wenyan , Wu Huijue , Luo Yanhong , Li Dongmei , Meng Qingbo
Published: April 2021

Besides widely used surface passivation, engineering the film crystallization is an important and more fundamental route to improve the performance of all‐inorganic perovskite solar cells. Herein, we have developed a urea‐ammonium thiocyanate (UAT) molten salt modification strategy to fully release and exploit coordination activities of SCN− to deposit high‐quality CsPbI3 film for efficient and stable all‐inorganic solar cells. The UAT is derived by the hydrogen bond interactions between urea and NH4+ from NH4SCN. With the UAT, the crystal quality of the CsPbI3 film has been significantly improved and a long single‐exponential charge recombination lifetime of over 30 ns has been achieved. With these benefits, the cell efficiency has been promoted to over 20 % (steady‐state efficiency of 19.2 %) with excellent operational stability over 1000 h. These results demonstrate a promising development route of the CsPbI3 related photoelectric devices.
Bioinspired Color Switchable Photonic Crystal Silicone Elastomer Kirigami
Authors: Lai Xintao , Peng Jingsong , Cheng Qunfeng , Tomsia Antoni P. , Zhao Guanlei , Liu Lei , Zou Guisheng , Song Yanlin , Jiang Lei , Li Mingzhu
Published: April 2021

Bioinspired dynamic structural color has great potential for use in dynamic displays, sensors, cryptography, and camouflage. However, it is quite rare for artificial structural color devices to withstand thousands of cycles. Male hummingbird's crowns and gorgets are brightly colored, demonstrating frequent color switching that is induced by regulating the orientation of the feathers through movement of skin or joints. Inspired by this unique structural color modulation, we demonstrate a flexible, mechanically triggered color switchable sheet based on a photonic crystal (PhC)‐coated polydimethylsiloxane (PDMS) kirigami (PhC‐PDMS kirigami) made by laser cutting. Finite element modeling (FEM) simulation reveals that the thickness of PDMS kirigami and the chamfer at the incision induced by laser cutting both dominate the out‐of‐plane deformation through in‐plane stretching. The bioinspired PhC‐PDMS kirigami shows precisely programmable structural color and keeps the color very well after recycling over 10 000 times. This bioinspired PhC‐PDMS kirigami also shows excellent viewability even in bright sunlight, high readability, robust functionality, technical flexibility, and mechanical durability, which are readily exploitable for applications, such as chromic mechanical monitors for the sports industry or for medical applications, wearable camouflage, and security systems.
Direct Synthesis of Ketones from Methyl Esters by Nickel‐Catalyzed Suzuki–Miyaura Coupling
Authors: Zheng Yan‐Long , Xie Pei‐Pei , Daneshfar Omid , Houk Kendall N. , Hong Xin , Newman Stephen G.
Published: April 2021

The direct conversion of alkyl esters to ketones has been hindered by the sluggish reactivity of the starting materials and the susceptibility of the product towards subsequent nucleophilic attack. We have now achieved a cross‐coupling approach to this transformation using nickel, a bulky N‐heterocyclic carbene ligand, and alkyl organoboron coupling partners. 65 alkyl ketones bearing diverse functional groups and heterocyclic scaffolds have been synthesized with this method. Catalyst‐controlled chemoselectivity is observed for C(acyl)−O bond activation of multi‐functional substrates bearing other bonds prone to cleavage by Ni, including aryl ether, aryl fluoride, and N‐Ph amide functional groups. Density functional theory calculations provide mechanistic support for a Ni0/NiII catalytic cycle and demonstrate how stabilizing non‐covalent interactions between the bulky catalyst and substrate are critical for the reaction's success.
Ratiometric Fluorescent Lateral Flow Immunoassay for Point‐of‐Care Testing of Acute Myocardial Infarction
Authors: Wang Jing , Jiang Chenxing , Jin Jiening , Huang Liang , Yu Wenbo , Su Bin , Hu Jun
Published: April 2021

We report the development of a highly sensitive ratiometric fluorescent lateral flow immunoassay (RFLFIA) strip for rapid and accurate detection of acute myocardial infarction biomarker, namely heart‐type fatty acid binding protein (H‐FABP). The RFLFIA strip works in terms of ratiometric change of fluorescence signal, arising from blending of fluorescence emitted by two composite nanostructures conjugated to capture and probe antibodies and inner filter effect of gold nanoparticles. In conjunction with using custom smartphone‐based analytical device and tonality analysis, quantitative detection of H‐FABP was achieved with a low limit of detection at 0.21 ng mL−1. The RFLFIA strip can generate a visually distinguishable green‐to‐red color change around the threshold concentration of H‐FABP (6.2 ng mL−1), thus allowing the semi‐quantitative diagnosis by the naked eye.
Kinetic Microscale Thermophoresis for Simultaneous Measurement of Binding Affinity and Kinetics
Authors: Stein Julian A. C. , Ianeselli Alan , Braun Dieter
Published: April 2021

Microscale thermophoresis (MST) is a versatile technique to measure binding affinities of binder–ligand systems, based on the directional movement of molecules in a temperature gradient. We extended MST to measure binding kinetics as well as binding affinity in a single experiment by increasing the thermal dissipation of the sample. The kinetic relaxation fingerprints were derived from the fluorescence changes during thermodynamic re‐equilibration of the sample after local heating. Using this method, we measured DNA hybridization on‐rates and off‐rates in the range 104–106 m−1 s−1 and 10−4–10−1 s−1, respectively. We observed the expected exponential dependence of the DNA hybridization off‐rates on salt concentration, strand length and inverse temperature. The measured on‐rates showed a linear dependence on salt concentration and weak dependence on strand length and temperature. For biomolecular interactions with large enthalpic contributions, the kinetic MST technique offers a robust, cost‐effective and immobilization‐free determination of kinetic rates and binding affinity simultaneously, even in crowded solutions.
Nickel‐Catalyzed Asymmetric Reductive Carbo‐Carboxylation of Alkenes with CO2
Authors: Chen Xiao‐Wang , Yue Jun‐Ping , Wang Kuai , Gui Yong‐Yuan , Niu Ya‐Nan , Liu Jie , Ran Chuan‐Kun , Kong Wangqing , Zhou Wen‐Jun , Yu Da‐Gang
Published: April 2021

Reductive carboxylation of organo (pseudo)halides with CO2 is a powerful method to provide carboxylic acids quickly. Notably, the catalytic reductive carbo‐carboxylation of unsaturated hydrocarbons via CO2 fixation is a highly challenging but desirable approach for structurally diverse carboxylic acids. There are only a few reports and no examples of alkenes via transition metal catalysis. We report the first asymmetric reductive carbo‐carboxylation of alkenes with CO2 via nickel catalysis. A variety of aryl (pseudo)halides, such as aryl bromides, aryl triflates and inert aryl chlorides of particular note, undergo the reaction smoothly to give important oxindole‐3‐acetic acid derivatives bearing a C3‐quaternary stereocenter. This transformation features mild reaction conditions, wide substrate scope, facile scalability, good to excellent chemo‐, regio‐ and enantioselectivities. The method highlights the formal synthesis of (−)‐Esermethole, (−)‐Physostigmine and (−)‐Physovenine, and the total synthesis of (−)‐Debromoflustramide B, (−)‐Debromoflustramine B and (+)‐Coixspirolactam A; thereby, opening an avenue for the total synthesis of chiral natural products with CO2.
Total Synthesis of the Spliceosome Modulator Pladienolide B via Asymmetric Alcohol‐Mediated syn‐ and anti‐Diastereoselective Carbonyl Crotylation
Authors: Yoo Minjin , Krische Michael J.
Published: April 2021

The potent spliceosome modulator pladienolide B, which bears 10 stereogenic centers, is prepared in 10 steps (LLS). Asymmetric alcohol‐mediated carbonyl crotylations catalyzed by ruthenium and iridium that occur with syn‐ and anti‐diastereoselectivity, respectively, were used to form the C20‐C21 and C10‐C11 C−C bonds.
Redefining Net‐Zero Water for Resilient Aquifers
Authors: Yonkofski Catherine , Tartakovsky Guzel , Feng Youcan , Loper Susan , Yoder Tim , Solana Amy
Published: April 2021

Key Takeaways

Net‐zero water for long‐term water security and sustainability can be best quantified by comparing consumption with the net freshwater balance, including source water recharge.

This approach can support individual decisions when investing in water infrastructure and water conservation projects or for identifying critical locations for aquifer recharge.

While the sites studied did not meet US Army's Net Zero water criteria using the traditional calculation, all achieved or have feasible plans to achieve Net Zero under this more holistic approach.
End‐to‐end continuous bioprocessing: Impact on facility design, cost of goods, and cost of development for monoclonal antibodies
Authors: Mahal Hanna , Branton Harvey , Farid Suzanne S.
Published: April 2021

This article presents a systematic approach to evaluate the business case for continuous processing that captures trade‐offs between manufacturing and development costs for monoclonal antibodies (mAbs). A decisional tool was built that integrated cost of goods (COG) with the cost of development models and new equipment sizing equations tailored to batch, hybrid, and end‐to‐end continuous processes. The COG analysis predicted that single‐use continuous facilities (sized using a dedicated downstream processing train per bioreactor) offer more significant commercial COG savings over stainless steel batch facilities at annual demands of 100–500 kg (~35%), compared to tonnage demands of 1–3 tons (~±10%) that required multiple parallel continuous trains. Single‐use batch facilities were found to compete with continuous options on COG only at 100 kg/year. For the scenarios where batch and continuous facilities offered similar COG, the analysis identified the windows of operation required to reach different COG savings with thresholds for the perfusion rate, volumetric productivity, and media cost. When considering the project lifecycle cost, the analysis indicated that while end‐to‐end continuous facilities may struggle to compete on development costs, they become more cost‐effective than stainless steel batch facilities when considering the total out‐of‐pocket cost across both drug development and commercial activities.
Efficient Synthesis of Monomeric Fe Species in Zeolite ZSM‐5 for the Low‐Temperature Oxidation of Methane
Authors: Yu Tao , Su Yang , Wang Aiqin , Weckhuysen Bert M. , Luo Wenhao
Published: April 2021

Direct oxidation of methane into value‐added C1 oxygenated products, such as methanol, is essential and remains a significant challenge in the field of catalysis. In this work, we have prepared Fe/ZSM‐5 materials via three different methods and investigated the influence of various preparation methods on the composition and catalytic performance of Fe/ZSM‐5 for the low‐temperature oxidation of methane. Through a combination of scanning transmission electron microscopy, ultraviolet‐visible diffuse reflectance and 57Fe Mössbauer spectroscopy, we have found that the highest proportion of monomeric Fe species of 71 % could be achieved in the ZSM‐5 zeolite by the solid‐state ion‐exchange method, affording an excellent C1 oxygenates yield of 120 mol/molFe with a C1 oxygenates selectivity of 96 % at 50 °C for 30 min in the aqueous solution of H2O2.
Efficient Electroreduction of CO2 to CO on Porous ZnO Nanosheets with Hydroxyl Groups in Ionic Liquid‐based Electrolytes
Authors: Wang Hui , Yang Dexin , Yang Jie , Ma Xiaoxue , Li Hongping , Dong Weiwei , Zhang Renjie , Feng Chongyang
Published: April 2021

Electrochemical reduction of CO2 is a very promising route to realize carbon cycle and alleviate energy shortage. Herein, the porous zinc oxide nanosheets with hydroxyl groups on carbon paper substrates (ZnO(OH)/CP‐x,×represents the deposition time) were proved to be excellent catalysts for CO2 electroreduction to CO. As far as we know, the hydroxyl groups were first introduced into ZnO catalysts for this reaction, which can enhance the surface areas and improve the capacity of binding CO2 by the formation of hydrogen bond. Especially, the total current density could reach 44.3 mA cm−2 with 97.8 % Faradaic efficiency (FE) of CO over ZnO(OH)/CP‐600 catalysts with moderate hydroxyl groups in 1‐butyl‐3‐methylimidazolium hexafluorophosphate ([Bmim]PF6, 30 wt%)/acetonitrile/H2O (5 wt%) ternary electrolytes at −2.0 V versus Ag/Ag+, although the self‐reduction of the catalysts could be occurred simultaneously during electrolysis. Besides, the composition of the electrolytes also can significantly modulate the catalytic activity and selectivity of CO. The outstanding performance of ZnO(OH)/CP‐600 catalyst resulted mainly from the introduction of hydroxyl groups, high surface area, good contact with the substrate, and synergy effect between the catalyst and the electrolyte.
Controllable Multicomponent Co‐Assembly Approach to Ordered Mesoporous Zirconia Supported with Well‐Dispersed Tungsten Oxide Clusters as High‐Performance Catalysts
Authors: Li Jichun , Yang Xuanyu , Ma Junhao , Yuan Chenyi , Ren Yuan , Cheng Xiaowei , Deng Yonghui
Published: April 2021

Zirconia supported WOx clusters with high acid strength and good stability are important solid acid catalysts in many reactions. However, conventional synthetic methods such as incipient‐wetness impregnation and co‐precipitation usually result in the products with low catalytic activity due to low surface area, uncontrollable and non‐homogeneous distribution of tungsten species. In this study, a facile multicomponent co‐assembly approach was utilized to straightforwardly synthesize ordered mesoporous WOx/ZrO2 composites (OMWZr) with mesopore size over 17 nm, pore volume of 0.13–0.18 cm3/g and surface area of 27.3–41.7 m2/g. The materials were composed of robust crystalline ZrO2 skeleton and well‐dispersed WOx clusters (polytungstates) in framework under the optimized conditions. The tungsten species were well stablized by the crystallized skeletons of mesoporous ZrO2, which can inhibit the growth of tetragonal ZrO2 but facilitate crystallization of monoclinic ZrO2. The states of tungsten species (monotungstates, polytungstates and crystalline WO3) can be precisely adjusted by their doping amount in framework and calcination temperature as well, which can further tune the surface acidity of OMWZr composites. Owing to the existence of numerous active surface WOx clusters generated over exposed surface of mesoporous ZrO2, the OMWZr catalysts not only show great spatial homogeneity of accessible Brønsted acid sites and feasible mass diffusion during catalytic reactions, but also display outstanding acid‐catalytic performance over hydrolysis reactions of benzaldehyde dimethyl acetal. The catalyst can be reused for more than 10 cycles, without reduction of catalytic activity and selectivity to benzaldehyde.
Sequential Tether‐Directed Synthesis of New [3 : 2 : 1] Hexakis‐Adducts of C60 with a Mixed Octahedral Addition Pattern
Authors: Wachter Michael , Jurkiewicz Lisa , Hirsch Andreas
Published: April 2021

A new concept for the regioselective synthesis of [3 : 2 : 1] hexakis‐adducts of fullerene C60 was developed. Based on sequential tether‐directed remote functionalizations, chiral [3 : 2] pentakis‐adducts with an incomplete octahedral addition pattern were synthesized via stepwise cyclopropanation of C60 with suitable macrocyclic tri‐ and bifunctional cyclomalonate tethers. The four resulting stereoisomers were isolated using chiral HPLC. The corresponding pairs of enantiomers show mirror image behavior in their CD‐spectra. The pentakis‐adducts served as suitable building blocks for the spatially controlled synthesis of mixed hexakis‐adducts. Implementation of functional group‐bearing monomalonates afforded octahedral [3 : 2 : 1] hexakis‐adducts suitable for the construction of larger molecular and supramolecular fullerene architectures in excellent yield.
Click and Release Chemistry for Activity‐Based Purification of β‐Lactam Targets
Authors: Saidjalolov Saidbakhrom , Braud Emmanuelle , Edoo Zainab , Iannazzo Laura , Rusconi Filippo , Riomet Margaux , Sallustrau Antoine , Taran Frédéric , Arthur Michel , Fonvielle Matthieu , Etheve‐Quelquejeu Mélanie
Published: April 2021

β‐Lactams, the cornerstone of antibiotherapy, inhibit multiple and partially redundant targets referred to as transpeptidases or penicillin‐binding proteins. These enzymes catalyze the essential cross‐linking step of the polymerization of cell wall peptidoglycan. The understanding of the mechanisms of action of β‐lactams and of resistance to these drugs requires the development of reliable methods to characterize their targets. Here, we describe an activity‐based purification method of β‐lactam targets based on click and release chemistry. We synthesized alkyne‐carbapenems with suitable properties with respect to the kinetics of acylation of a model target, the Ldtfm L,D‐transpeptidase, the stability of the resulting acylenzyme, and the reactivity of the alkyne for the cycloaddition of an azido probe containing a biotin moiety for affinity purification and a bioorthogonal cleavable linker. The probe provided access to the fluorescent target in a single click and release step.