bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Phytochemical Contents and Antioxidant Activity of Mentha spicata (Spearmint) Grown in Kano, Nigeria
Authors: Murtala M. , Abdulmumin T. M. , Abdulmumin Y. , Ismail S. Y. , Maimuna M. D. , Amina L. A. , Shahida S. I. , Sadiya A. B. , Abdullahi N. A. , Sadeeq M. S. , Shehu A. M.
Published: April 2022

Aim: Mentha spicata (spearmint) is a plant that spreads mainly in the temperate and sub-temperate zones of the world including Africa and is used in pharmaceutical and food industries. It has numerous medicinal importance uch as antibiotic, anti-inflammatory, anti-diabetic, anti-hyperlipidaemic and many more. This research examines the phytochemical and antioxidant property of Mentha spicata.

Methodology: Sample of Mentha spicata leaves were collected fresh from the cultivated farm and was extracted using distilled water prior to analysis. The phytochemicals determination was carried out in accordance with methods described by Velavan while the antioxidant property was evaluated using Diphenylpicrylhydrazyl (DPPH) radical scavenging assay.

Results: The result showed that the aqueous extract contain alkaloids, phenols, flavonoids, tannins, saponins glycosides, Terpenoids and anthraquinones at varying concentrations. The antioxidant activity was measured in percentage at different concentration of the extract as follows; 25 mg/dl (20.94±0.05%), 50 mg/dl (10.78±0.02%), 75 mg/dl (50.74±0.04%) and 100mg/dl (17.83±0.06%) respectively. The highest antioxidant activity was observed in 75mg/dl concentration.

Conclusion: The antioxidant activity observed could be attributed to the presence of flavonoids and phenols. Therefore, Mentha spicata can be used as a source of antioxidant and could improve the health status of individuals.
Formulation and Evaluation of Topical Gel Loaded with Fluconazole Niosomes
Authors: Sravan Gajjala , Latha K. , Padmavathi R. , Fatima Maimuna , Sravani C. V. Sai , Saritha M.
Published: April 2022

Aim: The study aims to formulate and evaluate topical gel-loaded fluconazole niosomes. Fluconazole is a macrolide antibacterial used against various susceptible bacteria. Niosomes have a substantial role in the delivery of drugs as they can reduce toxicity and modify pharmacokinetics and bioavailability. Niosomes which are applied topically improve the deposition of drugs within stratum corneum and epidermis at the same time reducing systemic availability.

Methodology: In current investigation, fluconazole was entrapped into niosomes by thin-film hydration technique with the optimization of various process parameters like entrapment efficiency, vesicle size, shape and in-vitro drug release studies.

Results: Optimized formulations FNS5 and FNT4 prepared with Span-60 and Tween-60 exhibited vesicle sizes of 845.6 nm and 164.2 nm, zeta potential -10.2 mV and -46.4 mV indicating the formulation has good stability. The optimized niosomes were integrated into carbopol 934 and guar gum gels and then extensively characterized for zeta potential and vesicle size.

Conclusion: The study demonstrated that entrapment of drugs into niosomes led to prolonged drug release time, enhanced permeation and drug retention.
Impact of low injected activity on data driven respiratory gating for PET/CT imaging with continuous bed motion
Authors: Meier Joseph G. , Diab Radwan H. , Connor Trevor M. , Mawlawi Osama R.
Published: April 2022

Data driven respiratory gating (DDG) in positron emission tomography (PET) imaging extracts respiratory waveforms from the acquired PET data obviating the need for dedicated external devices. DDG performance, however, degrades with decreasing detected number of coincidence counts. In this paper, we assess the clinical impact of reducing injected activity on a new DDG algorithm designed for PET data acquired with continuous bed motion (CBM_DDG) by evaluating CBM_DDG waveforms, tumor quantification, and physician's perception of motion blur in resultant images. Forty patients were imaged on a Siemens mCT scanner in CBM mode. Reduced injected activity was simulated by generating list mode datasets with 50% and 25% of the original data (100%). CBM_DDG waveforms were compared to that of the original data over the range between the aortic arch and the center of the right kidney using the Pearson correlation coefficient (PCC). Tumor quantification was assessed by comparing the maximum standardized uptake value (SUVmax) and peak SUV (SUVpeak) of reconstructed images from the various list mode datasets using elastic motion deblurring (EMDB) reconstruction. Perceived motion blur was assessed by three radiologists of one lesion per patient on a continuous scale from no motion blur (0) to significant motion blur (3). The mean PCC of the 50% and 25% dataset waveforms was 0.74 ± 0.18 and 0.59 ± 0.25, respectively. In comparison to the 100% datasets, the mean SUVmax increased by 2.25% (p = 0.11) for the 50% datasets and by 3.91% (p = 0.16) for the 25% datasets, while SUVpeak changes were within ±0.25%. Radiologist evaluations of motion blur showed negligible changes with average values of 0.21, 0.3, and 0.28 for the 100%, 50%, and 25% datasets. Decreased injected activities degrades the resultant CBM_DDG respiratory waveforms; however this decrease has minimal impact on quantification and perceived image motion blur.
Early‐onset leukoencephalomyelopathy due to a biallelic NDUFV1 variant in a mid‐forties patient
Authors: Gschwind Markus , Garcia Segarra Nuria , Schaller André , Bolognini Ramona , Nuoffer Jean‐Marc , Hourez Raphael , Deprez Manuel , Lhermitte Benoit , Maeder Philippe , Tran Christel , Kuntzer Thierry
Published: April 2022

We present a patient who developed, after an early‐onset, a stable course of spastic paraplegia and ataxia for 4 decades and eventually succumbed to two episodes of postinfectious lactic acidosis. Diagnostic workup including muscle biopsy and postmortem analysis, oxymetric analysis, spectrophotometric enzyme analysis, and MitoExome sequencing revealed a necrotizing leukoencephalomyelopathy due to the so far unreported biallelic variant of the NDUFV1 gene (p.(Pro122Leu)). This case extends our understanding of NDUFV1 variants with a 14‐fold longer lifetime than so far reported cases, and will foster sensitivity toward respiratory chain disease also in adult patients with sudden deteriorating neurological deficits.
Bacterial Toxin‐Triggered Release of Antibiotics from Capsosomes Protects a Fly Model from Lethal Methicillin‐Resistant Staphylococcus aureus (MRSA) Infection
Authors: Tonkin Renée L. , Klöckner Anna , Najer Adrian , Simoes da Silva Carolina J. , Echalier Cécile , Dionne Marc S. , Edwards Andrew M. , Stevens Molly M.
Published: April 2022

Antibiotic resistance is a severe global health threat and hence demands rapid action to develop novel therapies, including microscale drug delivery systems. Herein, a hierarchical microparticle system is developed to achieve bacteria‐activated single‐ and dual‐antibiotic drug delivery for preventing methicillin‐resistant Staphylococcus aureus (MRSA) bacterial infections. The designed system is based on a capsosome structure, which consists of a mesoporous silica microparticle coated in alternating layers of oppositely charged polymers and antibiotic‐loaded liposomes. The capsosomes are engineered and shown to release their drug payloads in the presence of MRSA toxins controlled by the Agr quorum sensing system. MRSA‐activated single drug delivery of vancomycin and synergistic dual delivery of vancomycin together with an antibacterial peptide successfully kills MRSA in vitro. The capability of capsosomes to selectively deliver their cargo in the presence of bacteria, producing a bactericidal effect to protect the host organism, is confirmed in vivo using a Drosophila melanogaster MRSA infection model. Thus, the capsosomes serve as a versatile multidrug, subcompartmentalized microparticle system for preventing antibiotic‐resistant bacterial infections, with potential applications to protect wounds or medical device implants from infections.
Au@MnSe2 Core–Shell Nanoagent Enabling Immediate Generation of Hydroxyl Radicals and Simultaneous Glutathione Deletion Free of Pre‐Reaction for Chemodynamic‐Photothermo‐Photocatalytic Therapy with Significant Immune Response
Authors: Wang Yuanlin , Sun Xiang , Han Yaqian , Wang Kai , Cheng Lixin , Sun Ye , Besenbacher Flemming , Yu Miao
Published: April 2022

As a typical tumor microenvironment‐responsive therapy, chemodynamic therapy (CDT), producing hydroxyl radicals (•OH) to eliminate tumor cells, has demonstrated great promise. Nevertheless, there are still major challenges: •OH generated from endogenous H2O2 is usually insufficient; the CDT effect is strongly dependent on the pre‐reaction with glutathione. Addressing the challenges, Au@MnSe2 core–shell nanoagent for synergetic chemodynamic‐photothermo‐photocatalytic therapy combined with tetramodal imaging, including magnetic resonance imaging, computed tomography, photoacoustic, and infrared thermal imaging is reported. Distinct from the reported glutathione‐depleting agents, Mn2+ in MnSe2 allows immediate generation of •OH, independent of pre‐reaction. Meanwhile, Mn3+ consumes glutathione by its conversion to Mn2+. The Au‐MnSe2 combination promotes photothermal conversion and photocatalytic reaction, resulting in largely enhanced •OH generation from endogenous H2O2 and significant hyperthermia. Meanwhile, immune response is effectively activated: the intratumoral expression of programmed cell death‐1 and proinflammatory cytokines increase to 4–7 folds; the cytotoxic and helper T lymphocytes cells in the tumor area increase to more than 2.5‐folds; an evident, temporary systemic immunostimulatory effect is demonstrated. High tumor inhibition rate (≈97.3%) and greatly prolonged survival are obtained. This highly‐integrated design coordinating three different therapies with four different imaging modals provide new possibilities for high‐performance theranostic nanoagents.
Mobile Nanobots for Prevention of Root Canal Treatment Failure
Authors: Dasgupta Debayan , Peddi Shanmukh , Saini Deepak Kumar , Ghosh Ambarish
Published: April 2022

Millions of root canal treatments fail worldwide due to remnant bacteria deep in the dentinal tubules located within the dentine tissue of human teeth. The complex and narrow geometry of the tubules renders current techniques relying on passive diffusion of antibacterial agents ineffective. Here, the potential of actively maneuvered nanobots is investigated to disinfect dentinal tubules, which can be incorporated during a standard root canal procedure. It is demonstrated that magnetically driven nanobots can reach the depths of the tubules not possible with current clinical practices. Subtle alterations of the magnetic drive allow both deep implantations of the nanobots isotopically distributed throughout the dentine and spatially controlled recovery from selected regions, further supported by numerical simulations. Finally, the integration of bactericidal therapeutic modality with the nanobots is demonstrated, thereby validating the tremendous potential of nanobots in dentistry and nanomedicine in general.
Surface Modification of Poly(ether ether ketone) by Simple Chemical Grafting of Strontium Chondroitin Sulfate to Improve its Anti‐Inflammation, Angiogenesis, Osteogenic Properties
Authors: Zheng Zhe , Hu Liqiu , Ge Yongmei , Qi Jianchao , Sun Qili , Li Zhenjian , Lin Lijun , Tang Bin
Published: April 2022

Besides inducing osteogenic differentiation, the surface modification of poly(ether ether ketone) (PEEK) is highly expected to improve its angiogenic activity and reduce the inflammatory response in the surrounding tissue. Herein, strontium chondroitin sulfate is first attempted to be introduced into the surface of sulfonated PEEK (SPEEK‐CS@Sr) based on the Schiff base reaction between PEEK and ethylenediamine (EDA) and the amidation reaction between EDA and chondroitin sulfate (CS). The surface characteristics of SPEEK‐CS@Sr implant are systematically investigated, and its biological properties in vitro and in vivo are also evaluated. The results show that the surface of SPEEK‐CS@Sr implant exhibits a 3D microporous structure and good hydrophilicity, and can steadily release Sr ions. Importantly, the SPEEK‐CS@Sr not only displays excellent biocompatibility, but also can remarkably promote cell adhesion and spread, improve osteogenic activity and angiogenic activity, and reduce the inflammatory response compared to the original PEEK. Therefore, this study presents the surface modification of PEEK material by simple chemical grafting of strontium chondroitin sulfate to improve its angiogenesis, anti‐inflammation, and osteogenic properties, and the as‐fabricated SPEEK‐CS@Sr has the potential to serve as a promising orthopedic implant in bone tissue engineering.
iP & OEIP – Cytokinin Micro Application Modulates Root Development with High Spatial Resolution
Authors: Pařízková Barbora , Antoniadi Ioanna , Poxson David J. , Karady Michal , Simon Daniel T. , Zatloukal Marek , Strnad Miroslav , Doležal Karel , Novák Ondřej , Ljung Karin
Published: April 2022

State‐of‐the‐art technology based on organic electronics can be used as a flow‐free delivery method for organic substances with high spatial resolution. Such highly targeted drug micro applications can be used in plant research for the regulation of physiological processes on tissue and cellular levels. Here, for the first time, an organic electronic ion pump (OEIP) is reported that can transport an isoprenoid‐type cytokinin, N6‐isopentenyladenine (iP), to intact plants. Cytokinins (CKs) are plant hormones involved in many essential physiological processes, including primary root (PR) and lateral root (LR) development. Using the Arabidopsis thaliana root as a model system, efficient iP delivery is demonstrated with a biological output – cytokinin‐related PR and LR growth inhibition. The spatial resolution of iP delivery, defined for the first time for an organic compound, is shown to be less than 1 mm, exclusively affecting the OEIP‐targeted LR. Results from the application of the high‐resolution OIEP treatment method confirm previously published findings showing that the influence of CKs may vary at different stages of LR development. Thus, OEIP‐based technologies offer a novel, electronically controlled method for phytohormone delivery that could contribute to unraveling cytokinin functions during different developmental processes with high specificity.
A Review on Printing of Responsive Smart and 4D Structures Using 2D Materials
Authors: Cataldi Pietro , Liu Mufeng , Bissett Mark , Kinloch Ian A.
Published: April 2022

3D printing is revolutionizing the manufacturing sector due to the myriad of materials and techniques available. Furthermore, it allows decentralized production sites for both industry and the public. However, it is restricted to static structures that cannot react to external stimuli or adapt to the environment and are, therefore, not suitable for functional and motile parts. Recently, two approaches are proposed to give dynamism to 3D printed structures: the printing of “stimulus‐responsive” (a.k.a. smart) materials and “4D printing,” the first implying features change due to a stimulus while the second indicating the time evolution of properties after a stimulus activation. Nanomaterials, particularly 2D nanomaterials, exhibit a broad and distinctive combination of features. Thus, they are highly effective at enabling this dynamism due to their morphological, optoelectrical, and mechanical properties. This review summarizes recent advances in 3D/4D printing of smart deformable and stimuli‐responsive materials which utilize 2D nanomaterials. The benefits of 2D materials in this framework are summarized, and how to translate their potential into 3D/4D printing is also discussed. The most promising achievements to date are deformable piezoresistive materials for strain sensing, Joule heaters, and actuators. Future advancements and possible upcoming application areas are finally proposed.
Hybrid Chiral MoS2 Layers for Spin‐Polarized Charge Transport and Spin‐Dependent Electrocatalytic Applications
Authors: Bian Zhiyun , Kato Kenichi , Ogoshi Tomoki , Cui Zhou , Sa Baisheng , Tsutsui Yusuke , Seki Shu , Suda Masayuki
Published: April 2022

The chiral‐induced spin selectivity effect enables the application of chiral organic materials for spintronics and spin‐dependent electrochemical applications. It is demonstrated on various chiral monolayers, in which their conversion efficiency is limited. On the other hand, relatively high spin polarization (SP) is observed on bulk chiral materials; however, their poor electronic conductivities limit their application. Here, the design of chiral MoS2 with a high SP and high conductivity is reported. Chirality is introduced to the MoS2 layers through the intercalation of methylbenzylamine molecules. This design approach activates multiple tunneling channels in the chiral layers, which results in an SP as high as 75%. Furthermore, the spin selectivity suppresses the production of H2O2 by‐product and promotes the formation of ground state O2 molecules during the oxygen evolution reaction. These potentially improve the catalytic activity of chiral MoS2. The synergistic effect is demonstrated as an interplay of the high SP and the high catalytic activity of the MoS2 layer on the performance of the chiral MoS2 for spin‐dependent electrocatalysis. This novel approach employed here paves way for the development of other novel chiral systems for spintronics and spin‐dependent electrochemical applications.
Hard‐Carbon Anodes for Sodium‐Ion Batteries: Recent Status and Challenging Perspectives
Authors: Shao Wenlong , Shi Haodong , Jian Xigao , Wu Zhong-Shuai , Hu Fangyuan
Published: April 2022

Sodium‐ion batteries (SIBs) hold great potential in the application of large‐scale energy storage. With the coming commercialization of SIBs, developing advanced anode of particularly hard carbon is becoming increasingly urgent yet challenging. Hard carbon still suffers from unclear sodium storage mechanism, unsatisfactory performance, and low initial Coulombic efficiency (ICE). Herein, the current state‐of‐the‐art advances in designing hard carbon anodes for high‐performance SIBs is summarized. First, the formation process of hard carbon and typical sodium storage models of “insertion–adsorption,” “adsorption–insertion,” “adsorption–pore filling,” and “adsorption–insertion–pore filling” are introduced systematically. Then, the key strategies including morphological engineering, heteroatom doping, and graphitic structure regulation are presented to enhance the capacity of hard carbon based on the in‐depth understanding of sodium storage behaviors. Subsequently, to promote the practical application of hard carbon, more attention is paid to the methods of ICE improvement, including electrolyte optimization, defect and surface engineering, and presodiation. Whereafter, hard‐carbon‐based SIBs and their intriguing applications are briefly sketched. Finally, future directions and challenging perspectives of hard‐carbon anodes for SIBs are proposed from the viewpoints of storage mechanisms, electrode structures, and presodiation techniques.
Designing Thermomechanical Stable Gel‐Polymer Electrolytes Mediated by Block‐Copolymer Nanofibers for Quasi‐Solid‐State Lithium Batteries
Authors: Guan Mengxin , Liu Shujie , Jiao Kejin , Huang Yue , Zhao Jing , Yan Jianhua
Published: April 2022

Gel‐polymer electrolytes (GPEs) are expected to play an important role in the next‐generation quasi‐solid‐state lithium batteries (SSLBs), but they suffer from severe thermal and mechanical instability. Herein, a viscoelastic nanofibrous GPE film with high thermomechanical stability for constructing stable quasi‐SSLBs is reported. The GPE is fabricated by in situ polymerization of methyl acrylate in a blockcopolymer (PVDF‐b‐PTFE) nanofiber film followed by being immersed into the commercial liquid electrolytes and then dried. The tough blockcopolymer film shows high polarity that not only enhances the thermomechanical stability, but also promotes the dissociation of Li salts to release more free ions, thereby improving the ionic conductivity of GPE. As a result, the GPE shows high heat resistant to 150 °C, a wide electrochemical window of 5.1 V, and a high Li+‐ion transference number of 0.56. When matching high loading cathodes of LiFePO4 (13.36 mg cm−2) or NCM523 (12.25 mg cm−2), both kinds of batteries present high cycling stability and rate capability at 25 °C. More practically, the GPE can be used to construct soft pack batteries with high capacities, showing appealing application prospects.
Computational Identification and Experimental Demonstration of High‐Performance Methane Sorbents
Authors: Nath Karabi , Ahmed Alauddin , Siegel Donald J. , Matzger Adam J.
Published: April 2022

Remarkable methane uptake is demonstrated experimentally in three metal‐organic frameworks (MOFs) identified by computational screening: UTSA‐76, UMCM‐152 and DUT‐23‐Cu. These MOFs outperform the benchmark sorbent, HKUST‐1, both volumetrically and gravimetrically, under a pressure swing of 80 to 5 bar at 298 K. Although high uptake at elevated pressure is critical for achieving this performance, a low density of high‐affinity sites (coordinatively unsaturated metal centers) also contributes to a more complete release of stored gas at low pressure. The identification of these MOFs facilitates the efficient storage of natural gas via adsorption and provides further evidence of the utility of computational screening in identifying overlooked sorbents.
Binaphthyl‐Bridged Pyrenophanes: Intense Circularly Polarized Luminescence Based on aD2Symmetry Strategy
Authors: Takaishi Kazuto , Murakami Sho , Yoshinami Fumiya , Ema Tadashi
Published: April 2022

A series ofD2‐symmetric macrocycles composed of alternately linked pyrene and binaphthyl moieties (binaphthyl‐bridged pyrenophanes) have been synthesized. Among them, a pyrenophane possessing ether linkers at the 2,7‐positions of the pyrenes exhibited intense circularly polarized luminescence (CPL) with a |glum| value of 0.053. This value is by far the highest for excimers and was not sensitive to temperature, solvent, or concentration. The CPL originated from a twisting pyrene excimer, with the (R)‐binaphthyl moieties producing a left‐handed twist excimer, which exhibited (−)‐CPL. The electric and magnetic transition dipole moments are perfectly parallel, which is the best relationship for strong CPL.
Dynamic metal–ligand cross‐link promoted mechanically robust and pH responsive hydrogels for shape memory, programmable actuation and resistive sensing application
Authors: Ghosh Ashis , Panda Prachishree , Ganguly Debabrata , Chattopadhyay Santanu , Das Rajat K.
Published: April 2022

Employing Fe3+‐dicarboxylate dynamic metal–ligand cross‐links in combination with low density chemical cross‐links, herein we have developed a mechanically robust and stretchable poly(acrylamide‐co‐maleic acid) hydrogel. The mechanical properties of these hydrogels can be controlled by altering the concentrations of maleic acid and Fe3+ ions. The hydrogels showed high tensile strength (~1–2 MPa), toughness (~3.3 MJ m−3) and stretchability (up to ~5 times of their original length) along with high compressive strength (~13.5 MPa). Because of the dynamic nature of the metal–ligand cross‐links, the hydrogels exhibited good self‐recovery, anti‐fatigue properties and fast self‐healing capacity. Since the Fe3+‐dicarboxylate cross‐links can be dissociated at low pH, the mechanical properties could further be tuned in response to the pH of the medium. This property is exploited to demonstrate shape memory behavior of these hydrogel materials. A temperature responsive bilayer actuator is reported, with poly(N‐isopropylacrylamide) as the thermoresponsive layer and the Fe3+ cross‐linked poly(acrylamide‐co‐maleic acid) hydrogel as the memorizing layer, demonstrating programmable and reversible shape transition. The application of these ionically conducting hydrogels as highly sensitive and flexible resistive strain sensor is also demonstrated.
Quadruply Fused Aromatic Heterocycles toward 4 V‐Class Robust Organic Cathode‐Active Materials
Authors: Hatakeyama‐Sato Kan , Go Choitsu , Akahane Tomoki , Kaseyama Takahiro , Yoshimoto Takuji , Oyaizu Kenichi
Published: April 2022

Quadruply fused aromatic heterocycles are examined as 4 V‐class organic cathode‐active materials. A newly synthesized dimethylfluoflavin‐substituted polymer displays reversible charge/discharge at high potentials of 3.5 and 4.1 V (vs. Li/Li+) as a cathode‐active material for organic secondary batteries. The robust redox‐active heterocycles enable the long cycle‐life (>1000) while maintaining the high potential over 4 V. The linear polymer backbone and radical spin configuration in the heterocycles are the keys to enhancing the voltages and the cycle life.
Coupling CRISPR interference with FACS enrichment: New approach in glycoengineering of CHO cell lines for therapeutic glycoprotein production
Authors: Glinšek Katja , Kramer Lovro , Krajnc Aleksander , Kranjc Eva , Pirher Nina , Marušič Jaka , Hellmann Leon , Podobnik Barbara , Štrukelj Borut , Ausländer David , Gaber Rok
Published: April 2022

Difficulties in obtaining and maintaining the desired level of the critical quality attributes (CQAs) of therapeutic proteins as well as the pace of the development are major challenges of current biopharmaceutical development. Therapeutic proteins, both innovative and biosimilars, are mostly glycosylated. Glycans directly influence the stability, potency, plasma half‐life, immunogenicity, and effector functions of the therapeutic. Hence, glycosylation is widely recognized as a process‐dependent CQA of therapeutic glycoproteins. Due to the typically high heterogeneity of glycoforms attached to the proteins, control of glycosylation represents one of the most challenging aspects of biopharmaceutical development. Here, we explored a new glycoengineering approach in therapeutic glycoproteins development, which enabled us to achieve the targeted glycoprofile of the Fc‐fusion protein in a fast manner. Coupling CRISPRi technology with lectin‐FACS sorting enabled downregulation of the endogenous gene involved in fucosylation and further enrichment of CHO cells producing Fc‐fusion proteins with reduced fucosylation levels. Enrichment of cells with targeted glycoprofile can lead to time‐optimized clone screening and speed up cell line development. Moreover, the presented approach allows isolation of clones with varying levels of fucosylation, which makes it applicable to a broad range of glycoproteins differing in target fucosylation level.
Synthesis of 6,6‐ and 7,7‐Difluoro‐1‐acetamidopyrrolizidines and Their Oxidation Catalyzed by the Nonheme Fe Oxygenase LolO
Authors: Panth Nabin , Wenger Eliott S. , Krebs Carsten , Bollinger J. Martin , Grossman Robert B.
Published: April 2022

LolO, a 2‐oxoglutarate‐dependent nonheme Fe oxygenase, catalyzes both the hydroxylation of 1‐exo‐acetamidopyrrolizidine (AcAP), a pathway intermediate in the biosynthesis of the loline alkaloids, and the cycloetherification of the resulting alcohol. We have prepared fluorinated AcAP analogues to aid in continued mechanistic investigation of the remarkable LolO‐catalyzed cycloetherification step. LolO was able to hydroxylate 6,6‐difluoro‐AcAP (prepared from N,O‐protected 4‐oxoproline) and then cycloetherify the resulting alcohol, forming a difluorinated analogue of N‐acetylnorloline and providing evidence for a cycloetherification mechanism involving a C(7) radical as opposed to a C(7) carbocation. By contrast, LolO was able to hydroxylate 7,7‐difluoro‐AcAP (prepared from 3‐oxoproline) but failed to cycloetherify it, forming (1R,2R,8S)‐7,7‐difluoro‐2‐hydroxy‐AcAP as the sole product. The divergent LolO‐catalyzed reactions of the difluorinated AcAP analogues provide insight into the LolO cycloetherification mechanism and indicate that the 7,7‐difluorinated compound, in particular, may be a useful tool to accumulate and characterize the iron intermediate that initiates the cycloetherification reaction.
Influence of the Linker Chemistry on the Photoinduced Charge‐Transfer Dynamics of Hetero‐dinuclear Photocatalysts
Authors: Zedler Linda , Müller Carolin , Wintergerst Pascal , Mengele Alexander K. , Rau Sven , Dietzek‐Ivanšić Benjamin
Published: April 2022

To optimize light‐driven catalytic processes, light‐mediated multi‐electron transfer dynamics in molecular dyads need to be studied and correlated with structural changes focusing on the catalytically active metastable intermediates. Here, spectro‐electrochemistry has been employed to investigate the structure‐dependent photoelectron transfer kinetics in catalytically active intermediates of two Ru−Rh catalysts for light‐driven NAD+ reduction. The excited‐state reactivity of short‐lived intermediates was studied along different photoreaction pathways by resonance Raman and time‐resolved transient absorption spectro‐electrochemistry with sub‐picosecond time resolution under operando conditions. The results demonstrate, for the first time, how the bridging ligand serves as a (multi‐)electron storage structure, mediates the strength of the electronic coupling of catalytic and photocenter and impacts the targeted electron transfer as well as parasitic electron‐transfer kinetics.
Sequential Nucleophilic Substitution of Phosphorus Trichloride with Alcohols in a Continuous‐Flow Reactor and Consideration of a Mechanism for Reduced Over‐reaction through the Addition of Imidazole
Authors: Kitamura Hiroshi , Otake Yuma , Sugisawa Naoto , Sugisawa Hiroki , Ida Tomonori , Nakamura Hiroyuki , Fuse Shinichiro
Published: April 2022

We demonstrate a sequential nucleophilic substitution of highly electrophilic and inexpensive phosphorus trichloride with three different alcohols in a continuous‐flow reactor. A variety of alcohols including ones that contained acid‐ and/or basic‐labile functionalities were rapidly reacted. A over nucleophilic substitution that occurred during reaction of the second alcohol was suppressed by the addition of imidazole. Density functional theory calculations of the sequential nucleophilic substitutions of alcohols were performed both with and without imidazole, and Berry pseudorotation was suggested as a rate‐limiting step in both cases. Herein, we discuss the reasons for the decreased selectivity in the absence of imidazole as well as those for improved selectivity in the presence of imidazole during the second nucleophilic substitution.
A Photoresponsive Receptor with a 105 Magnitude of Reversible Anion‐Binding Switching
Authors: Einkauf Jeffrey D. , Bryantsev Vyacheslav S. , Moyer Bruce A. , Custelcean Radu
Published: April 2022

Invited for the cover of this issue are Jeffrey Einkauf, Vyacheslav Bryantsev, Bruce Moyer, and Radu Custelcean from Oak Ridge National Laboratory. The image depicts an anion receptor functionalized with a new photoswitchable chromophore, the diiminoguanidinium group, with exceptionally strong sulfate‐binding affinity that can be turned off by photoirradiation with UV light. Read the full text of the article at 10.1002/chem.202200719.
Process Combination of VPP‐LED and Vacuum Die Casting for Producing Complex Ceramic 3D‐MID
Authors: Schubert Johannes , Weisser Philipp , Rosen Marcus , Zanger Frederik , Schulze Volker
Published: April 2022

Future developments lead to increasing demands on mechatronic integrated devices (MID). Therefore, ceramics have to be used as substrate material and conductor tracks have to be located in the interior of components to be sufficiently protected. A process combination of vat photopolymerization (VPP‐LED) and vacuum die casting is investigated for realizing such structures. First, optimized process parameters are derived by studying the filling behavior of straight capillaries. Subsequently, the results are transferred to complex additively manufactured substrates to derive design guidelines.
Impact of post‐pyrolysis wash on biochar properties
Authors: Fazzalari Anthony , Abou‐Zaid Mamdouh , Briens Cedric , Briens Lauren
Published: April 2022

Washing biochar modifies its properties for use as a soil amendment. The important biochar properties for use as a soil amendment are hydrophilicity, adsorption, and stability. Biochar was obtained with intermediate pyrolysis at 400°C of three different feedstocks: woodchips, Bayview Flowers Digestate, and Storm Fisher Digestate biomass. A simple wash with an aqueous surfactant solution improved the properties of the biochar for soil amendment, with a non‐ionic surfactant combined with oxidizing hydrogen peroxide being the most effective. The improved properties included the removal of tars and possible modification of surface properties that increased hydrophilicity and adsorption and decreased leaching of any hydrocarbons that could negatively impact the surroundings. As a result, the washed biochar will exhibit better water retention and a more hospitable environment for the growth of beneficial microorganisms. In addition, by making the biochar more hydrophilic, a wash will make its granulation easier, reducing dust emissions during its application and allowing its formulation with enhancement additives. Although many post‐pyrolysis treatments of biochars have been investigated, the proposed wash is simple and effective, with beneficial advantages for downstream processing and application as a soil amendment.
Comparison of Nitrogen Activation on Trinuclear Niobium and Tungsten Sulfide Clusters Nb3Sn and W3Sn (n=0–3): A DFT Study
Authors: Gurti Joseph Israel , Ding Xun‐Lei , Wang Ya‐Ya , Chen Yan , Li Wei , Wang Xin
Published: April 2022

The reaction of N2 with trinuclear niobium and tungsten sulfide clusters Nb3Sn and W3Sn (n=0–3) was systematically studied by density functional theory calculations with TPSS functional and Def2‐TZVP basis sets. Dissociations of N−N bonds on these clusters are all thermodynamically allowed but with different reactivity in kinetics. The reactivity of Nb3Sn is generally higher than that of W3Sn. In the favorite reaction pathways, the adsorbed N2 changes the adsorption sites from one metal atom to the bridge site of two metal atoms, then on the hollow site of three metal atoms, and at that place, the N−N bond dissociates. As the number of ligand S atoms increases, the reactivity of Nb3Sn decreases because of the hindering effect of S atoms, while W3S and W3S2 have the highest reactivity among four W3Sn clusters. The Mayer bond order, bond length, vibrational frequency, and electronic charges of the adsorbed N2 are analyzed along the reaction pathways to show the activation process of the N−N bond in reactions. The charge transfer from the clusters to the N2 antibonding orbitals plays an essential role in N−N bond activation, which is more significant in Nb3Sn than in W3Sn, leading to the higher reactivity of Nb3Sn. The reaction mechanisms found in this work may provide important theoretical guidance for the further rational design of related catalytic systems for nitrogen reduction reactions (NRR).
Photochromic Performance of Donor‐Acceptor Stenhouse Adducts in Polymer Binders and Solution
Authors: McDonough Rowan , Rudgley Nick , Majewski Oskar , Perkins Michael V. , Evans Richard A. , Lewis David A.
Published: April 2022

Donor‐acceptor Stenhouse adducts (DASAs) are an exciting new class of negative photochromic compounds, offering high colouration and rapid photo‐switching speeds, however the relationship between binder properties and photo‐switching behaviour of DASAs in films is poorly understood. The determination and analysis of rate constants of seven DASAs in five polymer binders showed a complex relationship between the glass transition temperature (Tg) of the binder, the solubility parameters of the matrix and the push‐pull nature of the donor and acceptor moieties. The rate constants of photo‐switching steps that require large degrees of molecular motion such as the actinic and thermal carbon‐carbon double bond rotations (kbleach and k−1) were found to be highly dependent on the Tg of the polymer binder, with higher Tg binders restricting these processes, resulting in slower switching rates and impacting changes in colour intensity. Correlation of rate constants with the Hansen solubility parameter for solvents and binders revealed strong relationships between the sum of the polarity and hydrogen bonding parameters (δP+δH) and the actinic and thermal carbon‐carbon double bond rotations (kbleach and k−1). This is attributed to changes in the zwitterionic resonance contributions of the triene with increases in these two solubility parameters.
A high step‐up dc‐dc converter based on P‐impedance source with reduced voltage stress
Authors: Lahooti Eshkevari Alireza , Mosallanjed Ali , Sepasian Mohammadsadegh
Published: April 2022

This paper proposes a new step‐up dc‐dc converter designed based on the P‐impedance source. High boost factor, single‐stage design, continuous input current, and low‐voltage stresses on switching devices, common‐ground, operating with low duty cycles, and high efficiency are the main advantages of the proposed unidirectional topology. Although the topology comprises two power switches, these are encountered with low‐voltage stresses. Thus, they can be readily picked up from low‐cost and low‐voltage rating semiconductors with low resistive losses. Moreover, operating with low duty cycles undoubtedly decreases the conduction losses of these switches and the converter. The input and output sections have the same ground line called the common‐ground feature. This circuit also operates with a continuous input current. In this article, the operating principle of the proposed topology has been investigated in detail. In order to examine the claims, simulation and experimental results are represented and evaluated. For this purpose, a 72 V/400 V/320 W prototype has been designed. Results show that the converter efficiency is almost equal to 95%. Higher boost factors, above six times, are obtained, and the voltage stresses on semiconductors are reduced by up to 80%, subject to the output voltage.
The two sides of a coin: Pathogenicity and potential therapeutic of LDLRQ722*
Authors: Zhou Yingchao , Tu Xin
Published: April 2022

Familial hypercholesterolemia (FH) is a severe inherited lipid metabolism dysfunction, characterized by high low‐density lipoprotein (LDL) cholesterol levels, mostly due to mutations in the LDL receptor (LDLR) gene. Whole exome sequencing was performed on a consanguineous Chinese FH family and identified a novel homozygous pathogenic mutation LDLR c.C2164T (p. Q722*), forming a novel truncated soluble LDLRQ722*. LDLRQ722* was secreted via the small extracellular vesicles (sEV) and located on the surface of sEV. LDLRQ722*exhibit ∼6% of the wild‐type LDLR activity. sEV containing LDLRQ722* protein reconstructed the lipid metabolism via heparan sulfate proteoglycans (HSPG) and clathrin‐mediated endocytosis. Currently, statins and PCSK9 inhibitors therapy are the mainstay treatment for FH. However, statins and PCSK9 inhibitors substantially vary depending on the residual LDLR activity, while LDLRQ722* reduced circulating LDL‐C levels independently of LDLR residual activity. The study provided new insight into the treatments of FH.
Progress in Gel Polymer Electrolytes for Sodium‐Ion Batteries
Authors: Zheng Jinyun , Li Wenjie , Liu Xinxin , Zhang Jiawei , Feng Xiangming , Chen Weihua
Published: April 2022

Sodium‐ion battery is a potential application system for large‐scale energy storage due to the advantage of higher nature abundance and lower production cost of sodium‐based materials. However, there exist inevitably the safety problems such as flammability due to the use of the same type of organic liquid electrolyte with lithium‐ion battery. Gel polymer electrolytes are being considered as an effective solution to replace conventional organic liquid electrolytes for building safer sodium‐ion batteries. In this review paper, the authors present a comprehensive overview of the research progress in electrochemical and physical properties of the gel polymer electrolyte‐based sodium batteries. The gel polymer electrolytes based on different polymer hosts namely poly(ethylene oxide), poly(acrylonitrile), poly(methyl methacrylate), poly(vinylidene fluoride), poly(vinylidene fluoride‐hexafluoro propylene), and other new polymer networks are summarized. The ionic conductivity, ion transference number, electrochemical window, thermal stability, mechanical property, and interfacial issue with electrodes of gel polymer electrolytes, and the corresponding influence factors are described in detail. Furthermore, the ion transport pathway and ion conduction mechanism are analyzed and discussed. In addition, the advanced gel polymer electrolyte systems including flame‐retardant polymer electrolytes, composite gel polymer electrolytes, copolymerization, single‐ion conducting polymer electrolytes, etc. with more superior and functional performance are classified and summarized. Finally, the application prospects, development opportunities, remaining challenges, and possible solutions are discussed.
Insights into Streptomyces coelicolor A3(2) growth and pigment formation with high‐throughput online monitoring
Authors: Finger Maurice , Sentek Fabio , Hartmann Lukas , Palacio‐Barrera Ana M. , Schlembach Ivan , Rosenbaum Miriam A. , Büchs Jochen
Published: April 2022

Streptomyces species are intensively studied for their ability to produce a variety of natural products. However, conditions influencing and leading to product formation are often not completely recognized. Therefore, in this study, high‐throughput online monitoring is presented as a powerful tool to gain in‐depth understanding of the cultivation of the model organism Streptomyces coelicolor A3(2). Through online measurements of oxygen transfer rate and autofluorescence, valuable information about availability of nutrients and product formation patterns of the pigments actinorhodin and undecylprodigiosin can be obtained and explained. Therefore, it is possible to determine the onset of pigmentation and to study in detail the influencing factors thereof. One factor identified in this study is the filling volume of the cultivation vessel. Slight variations led to varying pigmentation levels. By combining optical and metabolic online monitoring techniques, the correlation of the filling volume with pigmentation could be explained as a result of different growth trajectories caused by varying specific power inputs and their influence on the pellet formation of the filamentous system. Finally, experiments with the addition of supernatant from unpigmented and pigmented cultures could highlight the applicability of the presented approach to study quorum sensing and cell‐cell interaction.
Facile and Surfactant‐Free Routed Spherical Au@Pt Core–Shell–Satellite Nanoparticles as High‐Efficient and Stable Electrocatalyst for Methanol Oxidation
Authors: Yang Lei , Feng Hetian , Liang Wenkai , He Xiaodie , Wang Yawen , Li Dong , Zhang Junchang , Sun Yinghui , Tan Changhui , Jiang Lin
Published: April 2022

The spherical Au@Pt core–shell–satellite nanoparticles (NPs) are fabricated via a facile, efficient, and surfactant‐free method of seed‐mediated growth, and the electrocatalytic performance toward the methanol oxidation reaction (MOR) is systematically researched by cyclic voltammetry. Compared with commercial Pt/C, all the obtained Au@Pt NPs with such a core–shell–satellite structure exhibit greatly enhanced electrocatalytic activity and long‐term stability toward MOR. Among them, Au90@Pt10 NPs with less loading of Pt exhibit the most significantly enhanced electrocatalytic performance with a mass activity of 1.470 A mgPt−1, approximately 13 times that of commercial Pt/C (0.111 A mgPt−1) and specific activity (1.469 mA cm−2) approximately 9 times that of commercial Pt/C (0.157 mA cm−2). Au95@Pt5 NPs have the highest value of the oxidation current density (0.2615 mA cm−2), corresponding to 62.8% of its initial maximum value (0.4165 mA cm−2), showing higher stability at approximately 4000 s. Such a surfactant‐free synthesis technique of Au@Pt bimetallic NPs may be a simple method to prepare self‐supported bimetallic nanostructures, which is important to develop highly effective electrocatalysts for MORs.
Gene‐environment interaction in type 2 diabetes in Korean cohorts: Interaction of a type 2 diabetes polygenic risk score with triglyceride and cholesterol on fasting glucose levels
Authors: Lim Ji Eun , Kang Ji‐one , Ha Tae‐Woong , Jung Hae‐Un , Kim Dong Jun , Baek Eun Ju , Kim Han Kyul , Chung Ju Yeon , Rhee Sang Youl , Kim Mi Kyung , Kim Yeon‐Jung , Park Taesung , Oh Bermseok
Published: April 2022

Type 2 diabetes (T2D) is caused by genetic and environmental factors as well as gene‐environment interactions. However, these interactions have not been systematically investigated. We analyzed these interactions for T2D and fasting glucose levels in three Korean cohorts, HEXA, KARE, and CAVAS, using the baseline data with a multiple regression model. Two polygenic risk scores for T2D (PRST2D) and fasting glucose (PRSFG) were calculated using 488 and 82 single nucleotide polymorphisms (SNP) for T2D and fasting glucose, respectively, which were extracted from large‐scaled genome‐wide association studies with multiethnic data. Both lifestyle risk factors and T2D‐related biochemical measurements were assessed. The effect of interactions between PRST2D‐triglyceride (TG) and PRST2D‐total cholesterol (TC) on fasting glucose levels was observed as follows: β ± SE = 0.0005 ± 0.0001, p = 1.06 × 10−19 in HEXA, β ± SE = 0.0008 ± 0.0001, p = 2.08 × 10−8 in KARE for TG; β ± SE = 0.0006 ± 0.0001, p = 2.00 × 10−6 in HEXA, β ± SE = 0.0020 ± 0.0004, p = 2.11 × 10−6 in KARE, β ± SE = 0.0007 ± 0.0004, p = 0.045 in CAVAS for TC. PRST2D‐based classification of the participants into four groups showed that the fasting glucose levels in groups with higher PRST2D were more adversely affected by both the TG and TC. In conclusion, blood TG and TC levels may affect the fasting glucose level through interaction with T2D genetic factors, suggesting the importance of consideration of gene‐environment interaction in the preventive medicine of T2D.
Provenance of bauxite and clay deposits in the Carboniferous Benxi Formation, Western Henan, China: Constraints from U–Pb geochronology and regional geology
Authors: Sun Fengyu , Cao Gaoshe
Published: April 2022

The bauxite and clay deposits of Western Henan, located in the southern part of the North China Craton (NCC), are rich reserves of bauxite ore, and the provenance of this bauxite has received much attention. In this study, X‐ray diffraction and detrital zircon U–Pb dating (using laser ablation–inductively coupled plasma–mass spectrometry) were applied to determine the source(s) of the bauxite in the Carboniferous Benxi Formation. Our data, combined with regional geological and geochemical observations, suggest that detrital zircons from the deposits with ages of ca. 457 Ma were derived mainly from Caledonian intermediate–acidic granitic rocks of the North Qinling Orogenic Belt (NQOB). Zircon grains with Precambrian ages of 2,713 to 549 Ma may have been derived from metamorphic rocks within the NQOB. The Benxi Formation bauxite in this area lacks late Palaeozoic zircons, which may be related to its location, as it is proximal to the NQOB but far from sources of late Palaeozoic zircons in the Inner Mongolia Uplift.