bluuebunny/crossref_metadata_2025 huggingface dataset:
Functional Micro‐/Nanomaterials for Multiplexed Biodetection
Authors: Liu Xinyi , Wu Weijie , Cui Daxiang , Chen Xiaoyuan , Li Wanwan
Published: June 2021

When analyzing biological phenomena and processes, multiplexed biodetection has many advantages over single‐factor biodetection and is highly relevant to both human health issues and advancements in the life sciences. However, many key problems with current multiplexed biodetection strategies remain unresolved. Herein, the main issues are analyzed and summarized: 1) generating sufficient signal to label targets, 2) improving the signal‐to‐noise ratio to ensure total detection sensitivity, and 3) simplifying the detection process to reduce the time and labor costs of multiple target detection. Then, available solutions made possible by designing and controlling the properties of micro‐ and nanomaterials are introduced. The aim is to emphasize the role that micro‐/nanomaterials can play in the improvement of multiplexed biodetection strategies. Through analyzing existing problems, introducing state‐of‐the‐art developments regarding relevant materials, and discussing future directions of the field, it is hopeful to help promote necessary developments in multiplexed biodetection and associated scientific research.
Stimuli‐Responsive AIEgens
Authors: Zhang Jing , He Benzhao , Hu Yubing , Alam Parvej , Zhang Haoke , Lam Jacky W. Y. , Tang Ben Zhong
Published: June 2021

The unique advantages and the exciting application prospects of AIEgens have triggered booming developments in this area in recent years. Among them, stimuli‐responsive AIEgens have received particular attention and impressive progress, and they have been demonstrated to show tremendous potential in many fields from physical chemistry to materials science and to biology and medicine. Here, the recent achievements of stimuli‐responsive AIEgens in terms of seven most representative types of stimuli including force, light, polarity, temperature, electricity, ion, and pH, are summarized. Based on typical examples, it is illustrated how each type of systems realize the desired stimuli‐responsive performance for various applications. The key work principles behind them are ultimately deciphered and figured out to offer new insights and guidelines for the design and engineering of the next‐generation stimuli‐responsive luminescent materials for more broad applications.
Design and Mechanism of a Self‐Powered and Disintegration–Reorganization–Regeneration Power Supply with Cold Resistance
Authors: Dai Hanqing , Chen Yuanyuan , Dai Wenqing , Hu Zhe , Li Min , Zhang Wanlu , Xie Fengxian , Wei Wei , Guo Ruiqian , Zhang Guoqi
Published: June 2021

Up to now, power supplies designed based on the electrochemical reaction principle have had unavoidable defects, in that a complete redox reaction must be formed inside the power supply to operate normally, which makes it unable to be reconstructed and regenerated. Hence, the design and interpretation of this self‐powered and disintegration–reorganization–regeneration power supply are generally considered to be almost insurmountable obstacles to haunt both experimenters and theorists. Herein, a self‐powered and disintegration–reorganization–regeneration power supply with relatively stable discharge for 8.3 h is realized by the principle of ion‐selective diffusion, which regenerates by radical polymerization. Additionally, the mechanism is investigated systematically by molecular dynamics simulation, and this power supply with a variety of self‐powered and disintegration–reorganization–regeneration units can discharge continuously at freezing temperatures and variable temperature (0–25 °C). As a hypothetical model, a self‐powered and deformable arch bridge with disintegration and reorganization is fabricated. In the future, this power supply is expected to be applied in prosthetic limbs, bionic skins, implantable power supplies, mobile phones, portable computers, wearable devices, etc. Moreover, with the improvement of the stability and discharge life, it could promote major revolutionary breakthroughs in the fields of intelligent industrial automation, smart buildings, intelligent transportation systems, intelligent power systems, etc.
Tunable Fiber‐Cavity Enhanced Photon Emission from Defect Centers in hBN
Authors: Häußler Stefan , Bayer Gregor , Waltrich Richard , Mendelson Noah , Li Chi , Hunger David , Aharonovich Igor , Kubanek Alexander
Published: June 2021

Realization of quantum photonic devices requires coupling single quantum emitters to the mode of optical resonators. In this work, a hybrid system consisting of defect centers in few‐layer hexagonal boron nitride (hBN) grown by chemical vapor deposition and a fiber‐based Fabry–Pérot cavity is presented. The sub 10‐nm thickness of hBN and its smooth surface enable efficient integration into the cavity mode. This hybrid platform is operated over a broad spectral range larger than 30 nm and its tuneability is used to explore different coupling regimes. Consequently, very large cavity‐assisted signal enhancement up to 50‐fold and strongly narrowed linewidths are achieved, which is owing to cavity funneling, a record for hBN‐cavity systems. Additionally, an excitation and readout scheme is implemented for resonant excitation that allows to establish cavity‐assisted photoluminescence excitation (PLE) spectroscopy. This work marks an important milestone for the deployment of 2D materials coupled to fiber‐based cavities in practical quantum technologies.
Synthesis of 2‐Phosphoryl‐3‐Monofluorovinylindoles under Catalyst‐ and Additive‐Free Conditions
Authors: An Di , Sang Jingjing , Hu Rui , Chen Jichao , Feng Li , Rao Weidong
Published: June 2021

A synthetic approach for the synthesis 2‐phosphoryl‐3‐monofluorovinylindoles via cascade regioselective dehydrative phosphorylation/stereoselective defluorination of difluoromethylated 3‐indolylmethanols and H‐phosphine oxides under catalyst‐ and additive‐free conditions is described. The reaction could be scaled‐up without the need for column chromatography purification.

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Environmentally Friendly Thermoelectric Materials: High Performance from Inorganic Components with Low Toxicity and Abundance in the Earth
Authors: Caballero‐Calero Olga , Ares José R. , Martín‐González Marisol
Published: June 2021

This review article gives an overview of the recent research directions in eco‐friendly, non‐toxic, and earth‐abundant thermoelectric materials. It covers materials such as sulfides, tetrahedrites, earth‐abundant oxides, silicides, copper iodine, Half‐Heusler intermetallic compounds, nitrides, and other environmentally friendly thermoelectrics. In all cases, their history, structure, general characteristics, thermoelectric properties, synthesis methods, and related thermoelectric applications are compiled. It is also shown that they are starting to be an excellent alternative for producing cost‐effective, sustainable, and non‐toxic thermoelectric generators. This review does not try to include all possible materials, but to show that there are high zT thermoelectric materials that are starting to be an excellent alternative for producing cost‐effective, sustainable, and non‐toxic thermoelectric generators.
Low‐Dimensional Metal Halide Perovskite Crystal Materials: Structure Strategies and Luminescence Applications
Authors: Han Ying , Yue Sijia , Cui Bin‐Bin
Published: June 2021

Replacing methylammonium (MA+), formamidine (FA+), and/or cesium (Cs+) in 3D metal halide perovskites by larger organic cations have built a series of low‐dimensional metal halide perovskites (LDMHPs) in which the inorganic metal halide octahedra arranging in the forms of 2D layers, 1D chains, and 0D points. These LDMHPs exhibit significantly different optoelectronic properties from 3D metal halide perovskites (MHPs) due to their unique quantum confinement effects and large exciton binding energies. In particular, LDMHPs often have excellent broadband luminescence from self‐trapped excitons. Chemical composition, hydrogen bonding, and external factors (temperature and pressure etc.) determine structures and influence photoelectric properties of LDMHPs greatly, and especially it seems that there is no definite regulation to predict the structure and photoelectric properties when a random cation, metal, and halide is chosen to design a LDMHP. Therefore, this review discusses the construction strategies of the recent reported LDMHPs and their application progress in the luminescence field for a better understanding of these factors and a prospect for LDMHPs’ development in the future.
Improved Efficiency and Lifetime of Deep‐Blue Hyperfluorescent Organic Light‐Emitting Diode using Pt(II) Complex as Phosphorescent Sensitizer
Authors: Nam Sungho , Kim Ji Whan , Bae Hye Jin , Maruyama Yusuke Makida , Jeong Daun , Kim Joonghyuk , Kim Jong Soo , Son Won‐Joon , Jeong Hyein , Lee Jaesang , Ihn Soo‐Ghang , Choi Hyeonho
Published: June 2021

Although the organic light‐emitting diode (OLED) has been successfully commercialized, the development of deep‐blue OLEDs with high efficiency and long lifetime remains a challenge. Here, a novel hyperfluorescent OLED that incorporates the Pt(II) complex (PtON7‐dtb) as a phosphorescent sensitizer and a hydrocarbon‐based and multiple resonance‐based fluorophore as an emitter (TBPDP and ν‐DABNA) in the device emissive layer (EML), is proposed. Such an EML system can promote efficient energy transfer from the triplet excited states of the sensitizer to the singlet excited states of the fluorophore, thus significantly improving the efficiency and lifetime of the device. As a result, a deep‐blue hyperfluorescent OLED using a multiple resonance‐based fluorophore (ν‐DABNA) with Commission Internationale de L'Eclairage chromaticity coordinate y below 0.1 is demonstrated, which attains a narrow full width at half maximum of ≈17 nm, fourfold increased maximum current efficiency of 48.9 cd A−1, and 19‐fold improved half‐lifetime of 253.8 h at 1000 cd m−2 compared to a conventional phosphorescent OLED. The findings can lead to better understanding of the hyperfluorescent OLEDs with high performance.
Platelet‐Like Fusogenic Liposome‐Mediated Targeting Delivery of miR‐21 Improves Myocardial Remodeling by Reprogramming Macrophages Post Myocardial Ischemia‐Reperfusion Injury
Authors: Tan Haipeng , Song Ya'nan , Chen Jing , Zhang Ning , Wang Qiaozi , Li Qiyu , Gao Jinfeng , Yang Hongbo , Dong Zheng , Weng Xueyi , Wang Zhengmin , Sun Dili , Yakufu Wusiman , Pang Zhiqing , Huang Zheyong , Ge Junbo
Published: June 2021

Inflammatory modulations focusing on macrophage phenotype are promising candidates to promote better cardiac healing post myocardial ischemia‐reperfusion (MI/R) injury. However, the peak of monocyte/macrophage recruitment is later than the time when enhanced permeability and retention effect disappears, which greatly increases the difficulty of reprogramming macrophages through systemic administration. Meanwhile, the inability of nanomaterials to release their contents to specific intracellular locations through reasonable cellular internalization pathways is another obstacle to achieving macrophage reprogramming. Here, inspired by the increase in circulating platelet‐monocyte aggregates in patients′ post‐MI/R and the high efficiency of fusogenic liposomes to deliver contents to the cytoplasm of target cells, a platelet‐like fusogenic liposome (PLPs) is constructed. Under the coating of PLPs, mesoporous silica nanospheres with a payload of miR‐21, an anti‐inflammatory agent, can be specifically delivered to inflammatory monocytes in the blood circulation of MI/R induced mice. Then it directly enters the cytoplasm of monocytes through membrane fusion, thereby realizing the reparative reprogramming of the inflamed macrophages derived from it. In vivo administration of the resulting formula can effectively preserve the cardiac function of mice undergone MI/R. Minimal invasiveness and biological safety make this nano‐platform a promising approach of immunotherapy.
Inhibition of Lithium Dendrite Formation in Lithium Metal Batteries via Regulated Cation Transport through Ultrathin Sub‐Nanometer Porous Carbon Nanomembranes
Authors: Rajendran Sathish , Tang Zian , George Antony , Cannon Andrew , Neumann Christof , Sawas Abdulrazzag , Ryan Emily , Turchanin Andrey , Arava Leela Mohana Reddy
Published: June 2021

Suppressing Li dendrite growth has gained research interest due to the high theoretical capacity of Li metal anodes. Traditional Celgard membranes which are currently used in Li metal batteries fall short in achieving uniform Li flux at the electrode/electrolyte interface due to their inherent irregular pore sizes. Here, the use of an ultrathin (≈1.2 nm) carbon nanomembrane (CNM) which contains sub‐nanometer sized pores as an interlayer to regulate the mass transport of Li‐ions is demonstrated. Symmetrical cell analysis reveals that the cell with CNM interlayer cycles over 2x longer than the control experiment without the formation of Li dendrites. Further investigation on the Li plating morphology on Cu foil reveals highly dense deposits of Li metal using a standard carbonate electrolyte. A smoothed‐particle hydrodynamics simulation of the mass transport at the anode–electrolyte interface elucidates the effect of the CNM in promoting the formation of highly dense Li deposits and inhibiting the formation of dendrites. A lithium metal battery fabricated using the LiFePO4 cathode exhibits a stable, flat voltage profile with low polarization for over 300 cycles indicating the effect of regulated mass transport.
Progress and Perspectives in Photo‐ and Electrochemical‐Oxidation of Biomass for Sustainable Chemicals and Hydrogen Production
Authors: Luo Hui , Barrio Jesús , Sunny Nixon , Li Alain , Steier Ludmilla , Shah Nilay , Stephens Ifan E. L. , Titirici Maria‐Magdalena
Published: June 2021

Biomass is recognized as an ideal CO2 neutral, abundant, and renewable resource substitute to fossil fuels. The rich proton content in most biomass derived materials, such as ethanol, 5‐hydroxymethylfurfural (HMF) and glycerol allows it to be an effective hydrogen carrier. The oxidation derivatives, such as 2,5‐difurandicarboxylic acid from HMF, glyceric acid from glycerol are valuable products to be used in biodegradable polymers and pharmaceuticals. Therefore, combining biomass‐derived compound oxidation at the anode and hydrogen evolution reaction at the cathode in a biomass electrolysis or photo‐reforming reactor would present a promising strategy for coproducing high value chemicals and hydrogen with low energy consumption and CO2 emissions. This review aims to combine fundamental knowledge on photo and electro‐assisted catalysis to provide a comprehensive understanding of the general reaction mechanisms of different biomass‐derived molecule oxidation. At the same time, catalyst requirements and recent advances for various feedstock compounds are also reviewed in detail. Technoeconomic assessment and life cycle analysis are performed on various feedstocks to assess the relative benefits of various processes, and finally critical prospects are given on the challenges and opportunities for technology development to meet the sustainability requirement of the future global energy economy.
Supramolecular Zinc Porphyrin Photocatalyst with Strong Reduction Ability and Robust Built‐In Electric Field for Highly Efficient Hydrogen Production
Authors: Jing Jianfang , Yang Jun , Zhang Zijian , Zhu Yongfa
Published: June 2021

The ultrathin 2D self‐assembled tetrakis (4‐carboxyphenyl) zinc porphyrin (SA‐ZnTCPP) is successfully fabricated for photocatalytic hydrogen production. The H2 evolution rate is 3487.3 µmol g–1 h–1 under wide‐spectrum (300–698 nm), which is increased by ≈85 times compared with metal‐free self‐assembled tetrakis (4‐carboxyphenyl) porphyrin (SA‐TCPP). The significant promotion in photocatalytic activity of SA‐ZnTCPP comes from the deep conduction band (−1.01 V) contributed by the elevation of orbital energy level of porphyrin after Zn2+ coordination. In addition, the strong built‐in electric field boosts the rapid separation and mobility of photogenerated carriers. Consequently, the strong reduction driving force and faster electron transfer kinetics result in highly efficient photocatalytic hydrogen production of SA‐ZnTCPP. This work improves the understanding of the structure‐property relationship of metalloporphyrin‐based supramolecular photocatalysts and provides a general strategy at the molecular level for performance optimization of photocatalysts.
Short‐term effects of nitrogen source on soil properties and plant growth
Authors: Wacha Kenneth M. , Hatfield Jerry L. , O'Brien Peter L. , Dold Christian
Published: June 2021

A randomized complete block design experiment was performed in a growth chamber study to evaluate the short‐term impact of N amendment source on CO2 fluxes, aggregate stability, and aboveground plant biomass. Large intact soil cores (n = 6) were each segmented into three subplot treatment sources: (a) organic N (ORG‐N); (b) inorganic N (UAN‐32); and (c) no N added (no‐N), with both N sources applied at rates of 27.5 kg N ha–1. The experiment was run for 130 d, representing one growing season of winter wheat (Triticum aestivum L.). Soil CO2 fluxes accumulated during the growing season were 47.1, 36.6, and 24.6 mol m–2 for ORG‐N, UAN‐32, and no‐N treatments, respectively. Significantly higher aboveground plant biomass was harvested in the N source treatments compared with no‐N. Aggregate stability in ORG‐N was significantly higher than inorganic sources, UAN‐32 (p < .05). This study highlights that even over a short‐term study, organic N sources can increase soil biological activity and aggregation processes, indicating an increased capacity for several soil functions.
Molecular fingerprint and machine learning to accelerate design of high‐performance homochiral metal–organic frameworks
Authors: Qiao Zhiwei , Li Lifeng , Li Shuhua , Liang Hong , Zhou Jian , Snurr Randall Q.
Published: June 2021

Computational screening was employed to calculate the enantioseparation capabilities of 45 functionalized homochiral metal–organic frameworks (FHMOFs), and machine learning (ML) and molecular fingerprint (MF) techniques were used to find new FHMOFs with high performance. With increasing temperature, the enantioselectivities for (R,S)‐1,3‐dimethyl‐1,2‐propadiene are improved. The “glove effect” in the chiral pockets was proposed to explain the correlations between the steric effect of functional groups and performance of FHMOFs. Moreover, the neighborhood component analysis and RDKit/MACCS MFs show the highest predictive effect on enantioselectivities among the four ML classification algorithms with nine MFs that were tested. Based on the importance of MF, 85 new FHMOFs were designed, and a newly designed FHMOF, NO2‐NHOH‐FHMOF, with high similarity to the optimal MFs achieved improved chiral separation performance, with enantioselectivities of 85%. The design principles and new chiral pockets obtained by ML and MFs could facilitate the development of new materials for chiral separation.
Universal Singlet‐Triplet Qubits Implemented Near the Transverse Sweet Spot
Authors: Xie Wen‐Xin , Zhang Chengxian , Xue Zheng‐Yuan
Published: June 2021

The key to realizing fault‐tolerant quantum computation for singlet‐triplet (ST) qubits in semiconductor double quantum dot (DQD) is to operate both the single‐ and two‐qubit gates with high fidelity. The feasible way includes operating the qubit near the transverse sweet spot (TSS) to reduce the leading order of the noise, as well as adopting the proper pulse sequences which are immune to noise. The single‐qubit gates can be achieved by introducing an AC drive on the detuning near the TSS. The large dipole moment of the DQDs at the TSS has enabled strong coupling between the qubits and the cavity resonator, which leads to two‐qubit entangling gates. When operating in the proper region and applying modest pulse sequences, both single‐ and two‐qubit gates have fidelity higher than 99%. The results in this paper suggest that taking advantage of the appropriate pulse sequences near the TSS can be effective to obtain high‐fidelity ST qubits.
Synthesis of N‐Heterocycles via Oxidant‐Free Dehydrocyclization of Alcohols Using Heterogeneous Catalysts
Authors: Sun Kangkang , Shan Hongbin , Lu Guo‐Ping , Cai Chun , Beller Matthias
Published: June 2021

N‐Heterocycles, such as pyrroles, pyrimidines, quinazolines, and quinoxalines, are important building blocks for organic chemistry and the fine‐chemical industry. For their synthesis, catalytic borrowing hydrogen and acceptorless dehydrogenative coupling reactions of alcohols as sustainable reagents have received significant attention in recent years. To overcome the problems of product separation and catalyst reusability, several metal‐based heterogeneous catalysts have been reported to achieve these transformations with good yields and selectivity. In this Minireview, we summarize recent developments using both noble and non‐noble metal‐based heterogeneous catalysts to synthesize N‐heterocycles from alcohols and N‐nucleophiles via acceptorless dehydrogenation or borrowing hydrogen methodologies. Furthermore, this Minireview introduces strategies for the preparation and functionalization of the corresponding heterogeneous catalysts, discusses the reaction mechanisms and the roles of metal electronic states, and the influence of support Lewis acid–base properties on these reactions.
Photoelectron Circular Dichroism in the Photodetachment of Amino Acid Anions
Authors: Krüger Peter , Weitzel Karl‐Michael
Published: June 2021

The chirality of chemical compounds is of undisputed importance in science and technology. In particular with respect to pharmacological application most molecules of interest cannot be accessed by the powerful techniques developed in recent years for gas phase analytes. Here, we demonstrate that the combination of electrospray ionization (ESI) with the detection of photoelectron circular dichroism (PECD) provides access to chirality information applicable to molecular materials with negligible vapor pressure, for example, amino acids. To this end, glutamic acid and 3,4‐dihydroxyphenylalanine (DOPA) have been electrosprayed into the source of a chirality spectrometer, where photodetachment is enforced and the PECD is detected. The technique can be expected to be conceptually applicable to all chemical systems with chirality based on molecular properties.
Effects of shell powder size and content on the properties of polycaprolactone composites
Authors: Weng Fangqing , Zhang Peirui , Koranteng Ernest , Zhang Yu , Wu Qiangxian , Zeng Guoping
Published: June 2021

In this work, the effects of particle size and content of clam shell powder (CSP) on the mechanical properties and microstructure of clam shell powder‐polycaprolactone (CSP‐PCL) composites were studied. Accordingly, shell powder with particle size of 50, 100, 200, and 400 meshes, and CSP content of 30, 40, 50, and 60 wt%, respectively, were utilized to prepare CSP‐PCL composites. The interface structure and properties of CSP‐PCL composites were investigated by infrared spectroscopy (IR), X‐Ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry, thermogravimetric analysis (TGA), and tensile tests. The results showed that the tensile properties of the composite materials correlated with the particle size and content of the filler. For instance, the smaller the particle size of CSP (400 meshes), the better the tensile properties of the composite. What is more, the tensile properties of the composites were negatively affected by the amount of CSP content. In terms of microstructure, shell powder particles could disperse uniformly in the PCL matrix, and the CSP‐PCL composites with polyurethane prepolymer as compatibilizer gave a better compatibility.
Photosensitive acrylates containing bio‐based epoxy‐acrylate soybean oil for 3D printing application
Authors: Rosace Giuseppe , Palucci Rosa Raphael , Arrigo Rossella , Malucelli Giulio
Published: June 2021

Stereolithography is a 3D‐printing process that is rapidly shifting from being an expensive and limited technology to an affordable, precise, and fast method of mass production. However, most of the current resins are petroleum‐based, which makes them toxic, non‐degradable and with poor biocompatibility. In this study, a standard petroleum‐based resin containing urethane acrylate and acrylic monomers was combined with epoxy‐acrylate soybean oil (EASO), aiming to reduce its impact on the environment. Ratios varying from 10 to 50 wt% of EASO were incorporated into the commercial resin while maintaining the viscosity low, between 0.27 and 1.06 Pa s. The printed samples showed good quality and complete integration between the layers. The addition of 50 wt% of EASO increased the samples elongation at break by 108% (from 2.3% to 4.8%) and decreased the contact angle by 26.4% (from 72 to 53°). Moreover, the mixture showed good thermal and swelling stability and tensile strength in the range of other commercial cured systems. The addition of EASO may significantly contribute to the exploitation of greener materials, which well matches today's circular economy concept.
Contextualizing the relative importance of habitat connectivity for metapopulation persistence: A case study of a critically endangered fish
Authors: Coats Simon C. , Wilson Matthew , McIntosh Angus R.
Published: June 2021

Local population characteristics and habitat connectivity both have important influences on metapopulation persistence; however, the relative importance of each can vary depending on the ecological context, making it difficult to apply general ‘rules‐of‐thumb’ for conservation actions. This is particularly true in dendritic networks, where habitat connections are constrained.

By constructing a metapopulation model that specifically accounts for the unique characteristics and ecological system of a target species, the relative influence of local population characteristics and habitat connectivity on metapopulation persistence can be assessed more accurately.

This modelling approach was used to improve conservation outcomes for the Canterbury mudfish (kо̄waroNeochanna burrowsius), a critically endangered and poorly understood species that is endemic to the Canterbury Plains of Aotearoa/New Zealand. A spatially structured metapopulation model ofN. burrowsiuswas used to investigate the relationship between habitat patch connectivity, rate of population growth as limited by habitat quality (rconditional), and metapopulation persistence.

N. burrowsiusmetapopulation persistence increased most strongly under increases inrconditional, but increases in habitat connectivity also had positive effects (94% metapopulation persistence for highly connected networks vs. 39% metapopulation persistence for poorly connected networks whererconditional = 1.3).

Although rates of population growth were more influential than increases in habitat connectivity in this case study, both will be important to consider for effectively allocating conservation resources for metapopulations in dendritic networks, depending on what managers could effectively manipulate to enhance metapopulation persistence.
Anticancer activities, structure–activity relationship, and mechanism of action of 12‐, 14‐, and 16‐membered macrolactones
Authors: Wang Ruo
Published: June 2021

Cancer remains one of the major causes of death worldwide despite the encouraging breakthroughs in the discovery of novel chemotherapeutic agents in recent years. The development of new effective anticancer candidates still represents a challenging endeavor due to the severe anticancer demands and the emergence of drug‐resistant, especially multidrug‐resistant, cancers. Macrolactones could regulate multiple signaling pathways in cancer cells and demonstrated potential anticancer effects, including inhibition of proliferation, metastasis, and angiogenic activity. Accordingly, macrolactones possess excellent efficacy against both drug‐sensitive and drug‐resistant cancer cells, and the rational design of macrolactones may provide valuable therapeutic interventions for cancers. The purpose of this review is as follows: (1) outline the recent advances made in the development of 12‐, 14‐, and 16‐membered macrolactones with anticancer potential; (2) summarize the structure–activity relationship; and (3) discuss their anticancer mechanisms.
Lexical data augmentation for sentiment analysis
Authors: Xiang Rong , Chersoni Emmanuele , Lu Qin , Huang Chu‐Ren , Li Wenjie , Long Yunfei
Published: June 2021

Machine learning methods, especially deep learning models, have achieved impressive performance in various natural language processing tasks including sentiment analysis. However, deep learning models are more demanding for training data. Data augmentation techniques are widely used to generate new instances based on modifications to existing data or relying on external knowledge bases to address annotated data scarcity, which hinders the full potential of machine learning techniques. This paper presents our work using part‐of‐speech (POS) focused lexical substitution for data augmentation (PLSDA) to enhance the performance of machine learning algorithms in sentiment analysis. We exploit POS information to identify words to be replaced and investigate different augmentation strategies to find semantically related substitutions when generating new instances. The choice of POS tags as well as a variety of strategies such as semantic‐based substitution methods and sampling methods are discussed in detail. Performance evaluation focuses on the comparison between PLSDA and two previous lexical substitution‐based data augmentation methods, one of which is thesaurus‐based, and the other is lexicon manipulation based. Our approach is tested on five English sentiment analysis benchmarks: SST‐2, MR, IMDB, Twitter, and AirRecord. Hyperparameters such as the candidate similarity threshold and number of newly generated instances are optimized. Results show that six classifiers (SVM, LSTM, BiLSTM‐AT, bidirectional encoder representations from transformers [BERT], XLNet, and RoBERTa) trained with PLSDA achieve accuracy improvement of more than 0.6% comparing to two previous lexical substitution methods averaged on five benchmarks. Introducing POS constraint and well‐designed augmentation strategies can improve the reliability of lexical data augmentation methods. Consequently, PLSDA significantly improves the performance of sentiment analysis algorithms.
Gravitational radiation‐reaction driven instabilities in rotating neutron stars
Authors: Lin Zikun , Bratton Eric , Weber Fridolin , Orsaria Milva G. , Ranea‐Sandoval Ignacio F.
Published: June 2021

We investigate in this work two different types of instabilities that set limits on the rotation rates of neutron (compact) stars. The first one is that caused by rotation at the Kepler frequency, at which mass shedding at the star's equator sets in. The second limit is set by instabilities driven by the growth of gravitational radiation‐reaction (GRR) driven ‐modes of order , which are moderated by shear and bulk viscosity. The calculations are performed for two relativistic models for the nuclear equation of state, DD2 and ACB4. The latter accounts for a phase transition that gives rise to the existence of so‐called mass‐twin compact stars. Our results confirm that the stable rotation periods of cold neutron stars are determined by the modes and that these modes are excited at rotation periods between 1 and 1.4 ms (20–30% above the Kepler periods of these stars). The situation is reversed in hot neutron stars where bulk viscosity damps the GRR modes, pushing the excitation period of the ‐mode instability to values below the Kepler period. For cold mass‐twin compact stars, we find that the instability sets in at rotation periods between 0.8 and 1 ms (25–30% below the Kepler period). This feature may allow one to distinguish conventional neutron stars from their possibly existing mass‐twin counterparts observationally, provided the ‐mode instability, which is expected to compete with the ‐mode instability, sets the limit on stable rotation of compact stars.
An ion‐paired moxifloxacin nanosuspension eye drop provides improved prevention and treatment of ocular infection
Authors: Josyula Aditya , Omiadze Revaz , Parikh Kunal , Kanvinde Pranjali , Appell Matthew B. , Patel Pratikkumar , Saeed Hiwa , Sutar Yogesh , Anders Nicole , He Ping , McDonnell Peter J. , Hanes Justin , Date Abhijit A. , Ensign Laura M.
Published: June 2021

There are numerous barriers to achieving effective intraocular drug administration, including the mucus layer protecting the ocular surface. For this reason, antibiotic eye drops must be used multiple times per day to prevent and treat ocular infections. Frequent eye drop use is inconvenient for patients, and lack of adherence to prescribed dosing regimens limits treatment efficacy and contributes to antibiotic resistance. Here, we describe an ion‐pairing approach used to create an insoluble moxifloxacin–pamoate (MOX–PAM) complex for formulation into mucus‐penetrating nanosuspension eye drops (MOX–PAM NS). The MOX–PAM NS provided a significant increase in ocular drug absorption, as measured by the area under the curve in cornea tissue and aqueous humor, compared to Vigamox in healthy rats. Prophylactic and treatment efficacy were evaluated in a rat model of ocular Staphylococcus aureus infection. A single drop of MOX–PAM NS was more effective than Vigamox, and completely prevented infection. Once a day dosing with MOX–PAM NS was similar, if not more effective, than three times a day dosing with Vigamox for treating S. aureus infection. The MOX–PAM NS provided increased intraocular antibiotic absorption and improved prevention and treatment of ocular keratitis, and the formulation approach is highly translational and clinically relevant.
Improving antitumor immunity using antiangiogenic agents: Mechanistic insights, current progress, and clinical challenges
Authors: Li Shu‐Jin , Chen Jia‐Xian , Sun Zhi‐Jun
Published: June 2021

Cancer immunotherapy, especially immune checkpoint blockade (ICB), has revolutionized oncology. However, only a limited number of patients benefit from immunotherapy, and some cancers that initially respond to immunotherapy can ultimately relapse and progress. Thus, some studies have investigated combining immunotherapy with other therapies to overcome resistance to monotherapy. Recently, multiple preclinical and clinical studies have shown that tumor vasculature is a determinant of whether immunotherapy will elicit an antitumor response; thus, vascular targeting may be a promising strategy to improve cancer immunotherapy outcomes. A successful antitumor immune response requires an intact “Cancer‐Immunity Cycle,” including T cell priming and activation, immune cell recruitment, and recognition and killing of cancer cells. Angiogenic inducers, especially vascular endothelial growth factor (VEGF), can interfere with activation, infiltration, and function of T cells, thus breaking the “Cancer‐Immunity Cycle.” Together with immunostimulation‐regulated tumor vessel remodeling, VEGF‐mediated immunosuppression provides a solid therapeutic rationale for combining immunotherapy with antiangiogenic agents to treat solid tumors. Following the successes of recent landmark phase III clinical trials, therapies combining immune checkpoint inhibitors (ICIs) with antiangiogenic agents have become first‐line treatments for multiple solid tumors, whereas the efficacy of such combinations in other solid tumors remains to be validated in ongoing studies. In this review, we discussed synergies between antiangiogenic agents and cancer immunotherapy based on results from preclinical and translational studies. Then, we discussed recent progress in randomized clinical trials. ICI‐containing combinations were the focus of this review because of their recent successes, but combinations containing other immunotherapies were also discussed. Finally, we attempted to define critical challenges in combining ICIs with antiangiogenic agents to promote coordination and stimulate collaboration within the research community.
Studies on the Polyphenolic Composition and the Antioxidant Properties of the Leaves of Poplar (Populus spp.) Various Species and Hybrids
Authors: Pobłocka‐Olech Loretta , Głód Daniel , Jesionek Anna , Łuczkiewicz Maria , Krauze‐Baranowska Mirosława
Published: June 2021

The chemical composition in terms of flavonoid and salicylic compounds of leaves from 6 species and 3 hybrids of poplars (Populus) was identified with the use of TLC and HPLC‐DAD/ESI‐MS methods. Chromatographic analyses were carried out with 21 standard compounds including salicylic compounds (2), phenolic acids (3) and flavonoids (16). Moreover, on the basis of the obtained chromatographic data from the HPLC‐DAD/ESI‐MS and TLC separations, the presence of salicortin, tremulacin and chlorogenic acid was confirmed, depending on the analyzed poplar species or hybrid. The content of salicylic compounds was determined by HPLC‐UV method and expressed on salicin as free and total fraction. Total flavonoid content was determined by spectroscopic method as quercetin equivalent. Significant qualitative and quantitative differences in the chemical composition of the analyzed leaves were demonstrated. The highest concentration of flavonoids (8.02 mg/g) was found in the leaves of Populus nigra, while the highest content of salicylic compounds (47.14 mg/g) was found in the leaves of P.×berolinensis. The antioxidant and xanthine oxidase inhibition properties of extracts from poplar leaves were investigated by TLC bioautography. It has been shown that the richest set of compounds with antioxidant properties are present in the leaves of P. alba, P.×candicans and P. nigra.
Antinociceptive Activity of Compounds from the Aqueous Extract of Melampodium divaricatum
Authors: Pérez‐Vásquez Araceli , Padilla‐Mayne Sofía , Martínez Ana Laura , Calderón José S. , Macías‐Rubalcava Martha L. , Torres‐Colín Rafael , Rangel‐Grimaldo Manuel , Mata Rachel
Published: June 2021

A decoction prepared from the aerial parts of Melampodium divaricatum showed antinociceptive and antihyperalgesic responses when tested in the formalin model in mice. From the CH2Cl2 fraction of the decoction, two non‐previously reported secondary metabolites, 3‐O‐β‐D‐glucopyranosyl‐16α‐hydroxy‐ent‐kaurane (1) and melampodiamide (2) [(2′R*,4′Z)‐2′‐hydroxy‐N‐[(2S*,3S*,4R*)‐1,3,4‐trihydroxyoctadec‐2‐yl]tetracos‐4‐enamide] were separated and characterized by spectroscopic, spectrometric, and computational techniques. The flavonoids isoquercitrin and hyperoside, which possessed noted antinociceptive properties, were obtained from the active AcOEt fraction of the decoction. The chemical composition of the essential oil of the plant was also analyzed by gas chromatography‐mass spectrometry. The major constituents were (E)‐caryophyllene, germacrene D, β‐elemene, δ‐elemene, γ‐patchoulene, and 7‐epi‐α‐selinene. Headspace solid‐phase microextraction analysis detected (E)‐caryophyllene as the main volatile compound of the plant.
An Overview of Numerical Simulations on Gas‐Solid Cyclone Separators with Tangential Inlet
Authors: Dehdarinejad Ehsan , Bayareh Morteza
Published: June 2021

Cyclone separators play a dominating role in fluid catalytic cracking, biomass pyrolysis, dedusting, demisting, heavy oil regrading, etc. Separation mechanism, pressure drop, particle size, collection efficiency, gas underflow, gas inlet velocity, particle loading, cut‐off size of particles, and gas residence time are the main cyclone performance criteria. In the present work, the particle separation theory is explained and recent developments of numerical simulations of different cyclone separators with tangential inlet are summarized. Besides, the effect of different parameters on cyclone performance is discussed and several suggestions are provided based on previous numerical simulations.
Ionization and Photofragmentation of Isolated Metalloporphyrin Cations Investigated by VUV Action Spectroscopy**
Authors: Schubert Kaja , Schwob Lucas , Dörner Simon , Girod Marion , MacAleese Luke , Pieterse Cornelius L. , Schlathölter Thomas , Techert Simone , Bari Sadia
Published: June 2021

We investigated the photoionization and fragmentation of isolated metal protoporphyrin IX cations (MPPIX+ with M=Fe, Co, Zn) by means of vacuum‐ultraviolet (VUV) action spectroscopy in the energy range of 8.5–35 eV. Experiments were carried out in the gas phase by interfacing an electrospray ionization tandem mass spectrometer with a synchrotron beamline. The mass spectra and partial ion yields show that photoexcitation of the precursor ions predominantly leads to .CH2COOH radical side‐chain losses of the macrocycle with additional methyl radical (.CH3) side‐chain losses. Ionization, in contrast, leads to the formation of the intact ionized precursor and various doubly charged fragments which are mostly due to side‐chain cleavages. Although statistical fragmentation dominates, we found evidence for non‐statistical processes such as new fragments involving for example single and double H2O losses, indicating that different relaxation mechanisms are at play upon photoionization compared to photoexcitation. The measured ionization energies were 9.6±0.2 eV, 9.4±0.2 eV and 9.6±0.2 eV for FePPIX+, CoPPIX+ and ZnPPIX+, respectively.
One Key and Multiple Locks: Substrate Binding in Structures of Tryptophan Dioxygenases and Hydroxylases
Authors: Mammoli Andrea , Riccio Alessandra , Bianconi Elisa , Coletti Alice , Camaioni Emidio , Macchiarulo Antonio
Published: June 2021

Since its discovery at the beginning of the past century, the essential nutrient l‐Tryptophan (l‐Trp) and its catabolic pathways have acquired an increasing interest in an ever wider scientific community for their pivotal roles in underlying many important physiological functions and associated pathological conditions. As a consequence, enzymes catalyzing rate limiting steps along l‐Trp catabolic pathways ‐ including IDO1, TDO, TPH1 and TPH2 ‐ have turned to be interesting drug targets for the design and development of novel therapeutic agents for different disorders such as carcinoid syndrome, cancer and autoimmune diseases. This article provides a fresh comparative overview on the most recent advancements that crystallographic studies, biophysical and computational works have brought on structural aspects and molecular recognition patterns of these enzymes toward l‐Trp. Finally, a conformational analysis of l‐Trp is also discussed as part of the molecular recognition process governing the binding of a substrate to its cognate enzymes.
Hyper‐CVAD plus ofatumumab versus hyper‐CVAD plus rituximab as frontline therapy in adults with Philadelphia chromosome–negative acute lymphoblastic leukemia: A propensity score analysis
Authors: Sasaki Koji , Kantarjian Hagop M. , Morita Kiyomi , Short Nicholas J. , Konopleva Marina , Jain Nitin , Ravandi Farhad , Garcia‐Manero Guillermo , Wang Sa , Khoury Joseph D. , Jorgensen Jeffrey L. , Champlin Richard E. , Khouri Issa F. , Kebriaei Partow , Schroeder Heather M. , Khouri Maria , Garris Rebecca , Takahashi Koichi , O’Brien Susan M. , Jabbour Elias J.
Published: June 2021

Background

The outcome of hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone plus ofatumumab hyper‐CVAD + ofatumumab (hyper‐CVAD + ofatumumab) has not been compared with the outcome of hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone plus ofatumumab hyper‐CVAD plus rituximab (hyper‐CVAD + Rituximab) in Philadelphia chromosome–negative acute lymphoblastic leukemia (ALL) in a randomized clinical trial.

Methods

The authors compared the outcomes of 69 patients treated with hyper‐CVAD + ofatumumab and 95 historical‐control patients treated with hyper‐CVAD + Rituximab. Historical‐control patients were treated with hyper‐CVAD + Rituximab if they had CD20 expression ≥ 20%. Ofatumumab (day 1 of course 1, 300 mg intravenously; subsequent doses, 2000 mg intravenously) was administered on days 1 and 11 of courses 1 and 3 and on days 1 and 8 of courses 2 and 4 for a total of 8 doses. A propensity score analysis with inverse probability of treatment weighting (IPTW) was performed to adjust for baseline covariates between groups.

Results

The median event‐free survival with stem cell transplantation (SCT) censoring was 33 and 65 months with hyper‐CVAD + Rituximab and hyper‐CVAD + ofatumumab, respectively (crude P = .064; IPTW P = .054). The median overall survival with SCT censoring was 52 months and not reached, respectively (crude P = .087; IPTW P = .097).

Conclusions

Hyper‐CVAD + ofatumumab was associated with better outcomes than hyper‐CVAD + Rituximab among patients with newly diagnosed Philadelphia chromosome–negative ALL.
First line immunotherapy extends brain metastasis free survival, improves overall survival, and reduces the incidence of brain metastasis in patients with advanced melanoma
Authors: Wang Xuechen , Haaland Benjamin , Hu‐Lieskovan Siwen , Colman Howard , Holmen Sheri L.
Published: June 2021

Background

Recent advances in targeted therapy and immunotherapy have improved the prognosis of melanoma patients but brain metastasis remains a major challenge. Currently, it is unclear how existing therapies can be best used to prevent or treat brain metastasis in melanoma patients.

Aims

We aimed to assess brain metastasis free survival (BMFS), overall survival (OS), incidence of brain metastases, and sequencing strategies of immunotherapy and targeted therapy in patients with BRAF‐mutated advanced melanoma.

Methods and results

We retrospectively analyzed 683 patients with BRAF‐mutated advanced melanoma treated with first line (1L) immunotherapy (N = 266) or targeted therapy (N = 417). The primary outcome was BMFS. Secondary outcomes included OS of all patients and incidence of brain metastases in patients without documented brain metastases prior to 1L therapy. The median BMFS was 13.7 months [95% confidence interval (CI): 12.4–16.0] among all patients. The median BMFS for patients receiving 1L immunotherapy was 41.9 months [95% CI: 22.8–not reached (NR)] and targeted therapy was 11.0 months (95% CI: 8.8–12.5). Median OS results were qualitatively similar to BMFS results. The cumulative incidence of brain metastases for patients receiving 1L targeted therapy was higher than for patients receiving 1L immunotherapy (P < .001). Patients receiving 1L anti‐CTLA4 plus anti‐PD1 combination immunotherapy only or followed by second line (2L) targeted therapy had better BMFS (HR 0.40, 95% CI: 0.24–0.67,P = .001), improved OS (HR 0.49, 95% CI: 0.30–0.81,P = .005), and reduced incidence of brain metastases (HR 0.47, 95% CI: 0.24–0.67,P = .047) than patients receiving 1L combination BRAF and MEK targeted therapy followed by 2L immunotherapy.

Conclusion

Patients with advanced BRAF mutant melanoma treated with 1L immunotherapy have significantly longer BMFS and OS, and reduced incidence of brain metastases, compared with those treated with 1L targeted therapy. Further studies evaluating the ability of immunotherapy and targeted therapy to improve OS and prevent brain metastases are warranted