bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct Comparison of Lysine versus Site‐Specific Protein Surface Immobilization in Single‐Molecule Mechanical Assays**
Authors: Liu Haipei , Liu Zhaowei , Sá Santos Mariana , Nash Michael A. 
Published: June 2023

AbstractSingle‐molecule force spectroscopy (SMFS) is powerful for studying folding states and mechanical properties of proteins, however, it requires protein immobilization onto force‐transducing probes such as cantilevers or microbeads. A common immobilization method relies on coupling lysine residues to carboxylated surfaces using 1‐ethyl‐3‐(3‐dimethyl‐aminopropyl) carbodiimide and N‐hydroxysuccinimide (EDC/NHS). Because proteins typically contain many lysine groups, this strategy results in a heterogeneous distribution of tether positions. Genetically encoded peptide tags (e.g., ybbR) provide alternative chemistries for achieving site‐specific immobilization, but thus far a direct comparison of site‐specific vs. lysine‐based immobilization strategies to assess effects on the observed mechanical properties was lacking. Here, we compared lysine‐ vs. ybbR‐based protein immobilization in SMFS assays using several model polyprotein systems. Our results show that lysine‐based immobilization results in significant signal deterioration for monomeric streptavidin‐biotin interactions, and loss of the ability to correctly classify unfolding pathways in a multipathway Cohesin‐Dockerin system. We developed a mixed immobilization approach where a site‐specifically tethered ligand was used to probe surface‐bound proteins immobilized through lysine groups, and found partial recovery of specific signals. The mixed immobilization approach represents a viable alternative for mechanical assays on in vivo‐derived samples or other proteins of interest where genetically encoded tags are not feasible.
Pd‐Enriched‐Core/Pt‐Enriched‐Shell High‐Entropy Alloy with Face‐Centred Cubic Structure for C1 and C2 Alcohol Oxidation
Authors: Lao Xianzhuo , Liao Xuejiang , Chen Chen , Wang Jiasheng , Yang Likang , Li Ze , Ma Jun‐Wei , Fu Aiping , Gao Hongtao , Guo Peizhi 
Published: June 2023

AbstractHigh‐entropy alloy nanoparticles (HEA NPs) have aroused great interest globally with their unique electrochemical, catalytic, and mechanical properties, as well as diverse activity and multielement tunability for multi‐step reactions. Herein, a facile low‐temperature synthesis method at atmospheric pressure is employed to synthesize Pd‐enriched‐HEA‐core and Pt‐enriched‐HEA‐shell NPs with a single phase of face‐centred cubic structure. Interestingly, the lattice of both Pd‐enriched‐HEA‐core and Pt‐enriched‐HEA‐shell enlarge during the formation process of HEA, with tensile strains included in the core and shell of HEA. The as‐obtained PdAgSn/PtBi HEA NPs show excellent electrocatalytic activity and durability for methanol oxidation reaction (MOR) and ethanol oxidation reaction (EOR). The specific (mass) activity of PdAgSn/PtBi HEA NPs for MOR is 4.7 mA cm−2 (2874 mA mg(Pd+Pt)−1), about 1.7 (5.9) and 1.5 (4.8) times higher than that of commercial Pd/C and Pt/C catalysts, respectively. Additional to high‐entropy effect, Pt sites and Pd sites on the interface of the HEA act synergistically to facilitate the multi‐step process towards EOR. This study offers a promising way to find a feasible route for scalable HEA manufacturing with promising applications.
Stepwise O2‐Induced Rearrangement and Disassembly of the [NiFe4(OH)(μ3‐S)4] Active Site Cluster of CO Dehydrogenase
Authors: Basak Yudhajeet , Jeoung Jae‐Hun , Domnik Lilith , Dobbek Holger 
Published: June 2023

AbstractNi,Fe‐containing carbon monoxide dehydrogenases (CODHs) catalyze the reversible reduction of carbon dioxide to carbon monoxide. CODHs are found in anaerobic microorganisms and can rapidly lose their activity when exposed to air. What causes the loss of activity is unclear. In this study, we analyzed the time‐dependent structural changes induced by the presence of air on the metal centers of CODH‐II. We show that inactivation is a multistep process. In a reversible step, the open coordination site on the Ni ion is blocked by a Ni,Fe‐bridging μ‐sulfido or chlorido ligand. Blocking this open coordination site with a cyanide ligand stabilizes the cluster against O2‐induced decomposition, indicating that O2 attacks at the Ni ion. In the subsequent irreversible phase, nickel is lost, the Fe ions rearrange and the sulfido ligands disappear. Our data are consistent with a reversible reductive reactivation mechanism to protect CODHs from transient over‐oxidation.
Platinum/Copper Dual‐Catalyzed Asymmetric Vinylogous Addition Reactions for the Synthesis of Functionalized Indoles
Authors: Hu Qingdong , Guo Chang 
Published: June 2023

AbstractThe development of multicomponent ligands to improve catalytic reactivity and selectivity remains a significant challenge for the synthesis of chiral building blocks. Here, a modular synthesis of structurally diverse multiligated platinum complexes, characterized by X‐ray crystallography, was revealed to open up a previously inaccessible reaction space. A library of more than 16 binary component‐ligated platinum complexes was identified as a practical toolkit to enable faster screening. The isolated bench‐stable PtII(oxazoline)(phosphine) complex paired with a chiral copper complex exhibits fundamentally new cooperative reactivity. The newly designed Pt/Cu dual catalytic system contributed to the development of highly enantioselective vinylogous addition reactions between a Pt‐activated electrophilic α,β‐unsaturated carbene and a Cu‐activated nucleophile, resulting in a reliable process for the asymmetric synthesis of valuable functionalized indoles in good yields and excellent enantioselectivities.
Platinum Metallacycle‐Based Molecular Recognition: Establishment and Application in Spontaneous Formation of a [2]Rotaxane with Light‐Harvesting Property
Authors: Shi Bingbing , Li Xupeng , Chai Yongping , Qin Peng , Zhou Yi , Qu Wen‐Juan , Lin Qi , Wei Tai‐Bao , Sun Yan , Stang Peter J. 
Published: June 2023

AbstractMacrocyclic molecule‐based host–guest systems, which provide contributions for the design and construction of functional supramolecular structures, have gained increasing attention in recent years. In particular, platinum(II) metallacycle‐based host–guest systems provide opportunities for chemical scientists to prepare novel materials with various functions and structures due to the well‐defined shapes and cavity sizes of platinum(II) metallacycles. However, the research on platinum(II) metallacycle‐based host–guest systems has been given little attention. In this article, we demonstrate the host–guest complexation between a platinum(II) metallacycle and a polycyclic aromatic hydrocarbon molecule, naphthalene. Taking advantage of metallacycle‐based host–guest interactions and the dynamic property of reversible Pt coordination bonds, a [2]rotaxane is efficiently prepared by employing a template‐directed clipping procedure. The [2]rotaxane is further applied to the fabrication of an efficient light‐harvesting system with multi‐step energy transfer process. This work comprises an important supplement to macrocycle‐based host–guest systems and demonstrates a strategy for efficient production of well‐defined mechanically interlocked molecules with practical values.
Bismuth‐Catalyzed Amide Reduction
Authors: Yang Xiuxiu , Kuziola Jennifer , Béland Vanessa A. , Busch Julia , Leutzsch Markus , Burés Jordi , Cornella Josep 
Published: June 2023

AbstractIn this article we report that a cationic version of Akiba's BiIII complex catalyzes the reduction of amides to amines using silane as hydride donor. The catalytic system features low catalyst loadings and mild conditions, en route to secondary and tertiary aryl‐ and alkylamines. The system tolerates functional groups such as alkene, ester, nitrile, furan and thiophene. Kinetic studies on the reaction mechanism result in the identification of a reaction network with an important product inhibition that is in agreement with the experimental reaction profiles.
Tailoring Ion Ordering in Perovskite Oxide for High‐Temperature Oxygen Evolution Reaction
Authors: Liu Qingxue , Shen Feiran , Song Guohui , Liu Tianfu , Feng Weicheng , Li Rongtan , Zhang Xiaomin , Li Mingrun , He Lunhua , Zheng Xu , Yin Shuaishuai , Yin Guangzhi , Song Yuefeng , Wang Guoxiong , Bao Xinhe 
Published: June 2023

AbstractPerovskites exhibit excellent high‐temperature oxygen evolution reaction (OER) activities as the anodes of solid oxide electrolysis cells (SOECs). However, the relationship between ion ordering and OER performances is rarely investigated. Herein, a series of PrBaCo2−xFexO5+δ perovskites with tailored ion orderings are constructed. Physicochemical characterizations and density functional theory calculations confirm that the oxygen bulk migration and surface transport capacities as well as the OER activities are promoted by the A‐site cation ordering, but weakened by the oxygen vacancy ordering. Hence, SOEC with the A‐site‐ordered and oxygen‐vacancy‐disordered PrBaCo2O5+δ anode exhibits the highest performance of 3.40 A cm−2 at 800 °C and 2.0 V. This work sheds light on the critical role of ion orderings in the high‐temperature OER performance and paves a new way for screening novel anode materials of SOECs.
Engineered Histidine‐Rich Peptides Enhance Endosomal Escape for Antibody‐Targeted Intracellular Delivery of Functional Proteins
Authors: Zhao Yan , Jiang Haolin , Yu Jiazhen , Wang Luyao , Du Juanjuan 
Published: June 2023

AbstractCurrently, the clinical application of protein/peptide therapeutics is mainly limited to the modulation of diseases in extracellular spaces. Intracellular targets are hardly accessed, owing largely to the endosomal entrapment of internalized proteins/peptides. Here, we report a strategy to design and construct peptides that enable endosome‐to‐cytosol delivery based on an extension of the “histidine switch” principle. By substituting the Arg/Lys residues in cationic cell‐penetrating peptides (CPPs) with histidine, we obtained peptides with pH‐dependent membrane‐perturbation activity. These peptides do not randomly penetrate cells like CPPs, but imitate the endosomal escape of CPPs following cellular uptake. Working with one such 16‐residue peptide (hsLMWP) with high endosomal escape capacity, we engineered modular fusion proteins and achieved antibody‐targeted delivery of diverse protein cargoes—including the pro‐apoptotic protein BID (BH3‐interacting domain death agonist) and Cre recombinase—into the cytosol of multiple cancer cell types. After extensive in vitro testing, an in vivo analysis with xenograft mice ultimately demonstrated that a trastuzumab‐hsLMWP‐BID fusion conferred strong anti‐tumor efficacy without apparent side effects. Notably, our fusion protein features a modular design, allowing flexible applications for any antibody/cargo combination of choice. Therefore, the potential applications extend throughout life science and biomedicine, including gene editing, cancer treatment, and immunotherapy.
Preparative Scale Applications of C−H Activation in Medicinal Chemistry
Authors: de Jesus Rita , Hiesinger Kerstin , van Gemmeren Manuel 
Published: June 2023

AbstractC−H activation is an attractive methodology to increase molecular complexity without requiring substrate prefunctionalization. In contrast to well‐established cross‐coupling methods, C−H activation is less explored on large scales and its use in the production of pharmaceuticals faces substantial hurdles. However, the inherent advantages, such as shorter synthetic routes and simpler starting materials, motivate medicinal chemists and process chemists to overcome these challenges, and exploit C−H activation steps for the synthesis of pharmaceutically relevant compounds. In this review, we will cover examples of drugs/drug candidates where C−H activation has been implemented on a preparative synthetic scale (range between 355 mg and 130 kg). The optimization processes will be described, and each example will be examined in terms of its advantages and disadvantages, providing the reader with an in‐depth understanding of the challenges and potential of C−H activation methodologies in the production of pharmaceuticals.
Toughening of alicyclic epoxy resin by in situ polymerization of modifier vinyl monomers using alkylborane as a radical initiator
Authors: Kajihara Yuri , Oyama Toshiyuki 
Published: June 2023

AbstractIn this study, we attempted to improve the toughness of alicyclic epoxy cured resin using a vinyl polymer as a modifier which was generated with alkylborane as a radical initiator in parallel with the curing of the resin. Alkylborane has the ability to initiate radical polymerization around room temperature in the presence of oxygen, and the use of diethylmethoxyborane (DEMB) instead of a conventional peroxide radical initiator (DBPC) was found to allow copolymerization of styrene (St) and N‐phenylmaleimide (NPMI) in an alicyclic epoxy resin in the early stage of the multistep curing. As a result, only when DEMB was used as an initiator, a cured product with a phase‐separated structure at which ca. 50–100 nm St/NPMI copolymer phases were dispersed was obtained. The fracture toughness (KIC) of the modified cured resin with DEMB was 0.77 MN/m3/2, which was 30% higher than that of the modified resin with DBPC. Furthermore, the glass transition temperature of the modified cured resin with DEMB reached 247°C, which was 87 and 63°C higher than the unmodified rein and the modified resin with DBPC, respectively, since DEMB acted as a Lewis acid to promote cationic polymerization of the alicyclic epoxy resin.
Characterization of glutathione‐specific gamma glutamyl cyclotransferase (ChaC) in Bombyx mori
Authors: Afrin Wazifa , Yamada Naotaka , Furuya Shigeki , Yamamoto Kohji 
Published: June 2023

AbstractGlutathione (GSH) contributes to redox maintenance and detoxification of various xenobiotic and endogenous substances. γ‐glutamyl cyclotransferase (ChaC) is involved in GSH degradation. However, the molecular mechanism underlying GSH degradation in silkworms (Bombyx mori) remains unknown. Silkworms are lepidopteran insects that are considered to be an agricultural pest model. We aimed to examine the metabolic mechanism underlying GSH degradation mediated by B. mori ChaC and successfully identified a novel ChaC gene in silkworms (herein, bmChaC). The amino acid sequence and phylogenetic tree revealed that bmChaC was closely related to mammalian ChaC2. We overexpressed recombinant bmChaC in Escherichia coli, and the purified bmChaC showed specific activity toward GSH. Additionally, we examined the degradation of GSH to 5‐oxoproline and cysteinyl glycine via liquid chromatography–tandem mass spectrometry. Quantitative real‐time polymerase chain reaction revealed that bmChaC mRNA expression was observed in various tissues. Our results suggest that bmChaC participates in tissue protection via GSH homeostasis. This study provides new insights into the activities of ChaC and the underlying molecular mechanisms that can aid the development of insecticides to control agricultural pests.
Inorganic polyphosphate's role in energy production and mitochondrial permeability transition pore opening in tick mitochondria
Authors: Domingues George , Moraes Jorge , Fonseca Rodrigo Nunes da , Campos Eldo 
Published: June 2023

AbstractInorganic polyphosphate (polyP) is a biopolymer composed of phosphoanhydride‐linked orthophosphate molecules. PolyP is engaged in a variety of cellular functions, including mitochondrial metabolism. Here, we examined the effects of polyP on electron transport chain enzymes and F1Fo ATP synthase in tick embryos during embryonic development. The study found that polyPs containing medium and long chains (polyP15 and polyP65) enhanced the activity of complex I, complex II, complex III, and F1Fo ATP synthase, while short polyP chains (polyP3) had no effect. The study also examined the activity of exopolyphosphatases (PPX) in various energy‐demand situations. PPX activity was stimulated when ADP concentrations are high, characterizing a low‐energy context. When complexes I–III and F1Fo ATP synthase inhibitors were added in energized mitochondria, PPX activity decreased, whereas the mitochondrial uncoupler FCCP had no impact on PPX activity. Additionally, the study investigated the effect of polyP on mitochondrial swelling, finding that polyP causes mitochondrial swelling by increasing calcium effects on the mitochondrial permeability transition pore. The findings presented here to increase our understanding of the function of polyP in mitochondrial metabolism and its relationship to mitochondrial permeability transition pore opening in an arthropod model.
Identification and characterization of Prx5 and Prx6 in Chilo suppressalis in response to environmental stress
Authors: Mo Wujia , Li Qiang , He Xiaochan , Lu Zhongxian , Xu Hongxing , Zheng Xusong , Guo Jiawen , Lu Yanhui , Wang Shuping 
Published: June 2023

AbstractThe antioxidant proteins, peroxiredoxins (Prxs), function to protect insects from reactive oxygen species‐induced toxicity. In this study, two Prx genes, CsPrx5, and CsPrx6, were cloned and characterized from the paddy field pest, Chilo suppressalis, containing open reading frames of 570 and 672 bp encoding 189 and 223 amino acid polypeptides, respectively. Then, we investigated the influence of various stresses on their expression levels using quantitative real‐time PCR (qRT‐PCR). The results showed expression of CsPrx5 and CsPrx6 in all developmental stages, with eggs having the highest level. CsPrx5 and CsPrx6 showed higher expression in the epidermis and fat body, and CsPrx6 also showed higher expression in midgut, fat body, and epidermis. Increasing concentrations of insecticides (chlorantraniliprole and spinetoram) and hydrogen peroxide (H2O2) increased the expression levels of CsPrx5 and CsPrx6. In addition, the expression levels of CsPrx5 and CsPrx6 were almost markedly upregulated in larvae under temperature stress or fed by vetiver. Thus, CsPrx5 and CsPrx6 upregulation might increase the C. suppressalis defense response by reducing the impact of environmental stress, providing a better understanding of the relationship between environmental stresses and insect defense systems.
Benzotriazole scaffold: An overview of antiproliferative potential, mechanisms of action, and structure–activity relationships
Authors: Kassab Asmaa E. 
Published: June 2023

AbstractBeing an isostere of the purine nucleus, which is found in naturally occurring nucleotides like ATP and other naturally available substances, benzotriazole is not surprising for its broad‐spectrum biological activity. Benzotriazole is widely used by medicinal chemists as a privileged scaffold for the identification and development of novel bioactive compounds and drug candidates. Additionally, benzotriazole is a structural motif of seven pharmaceuticals; some of these compounds are approved, commercially available medications, while others are experimental drugs still under investigation. This review highlights the defining role of benzotriazole derivatives in the search for potential anticancer agents published in the literature from 2008 to 2022; it also discusses their mechanisms of action and structure–activity relationship investigations.
Layered Titanium Sulfide Cathode for All‐Solid‐State Magnesium Batteries
Authors: Skov Lasse N. , Grinderslev Jakob B. , Jensen Torben R. 
Published: June 2023

AbstractMagnesium solid‐state batteries attract significant attention as a future mean of energy storage. Here we present the first cathode study of an inorganic all‐solid‐state magnesium battery using a magnesium metal anode, a nanocomposite electrolyte Mg(BH4)2 ⋅ 1.6NH3‐MgO (75 wt %), and a layered titanium disulfide (TiS2) as cathode active material. The structural transformations of TiS2 particles with different sizes are investigated at different stages of battery life. Reversible Mg2+ intercalation occurs via three structurally distinct phases of MgxTiS2, identified by powder X‐ray diffraction. Magnesium intercalates initially on octahedral sites and at higher depth of discharge on tetrahedral sites in the interlayers of TiS2, which leads to an expansion initially mainly along the c‐axis and later along both the a‐ and c‐axes. A maximum discharge capacity of 172 mAh g−1 (Δx=0.36 in MgxTiS2) is observed for smaller TiS2 particles. Parasitic reactions could be reduced by decreasing the cut‐off voltage by a constant current constant voltage cycling procedure. The chemical diffusion coefficient of the entire cell is found from galvanostatic intermittent titration technique experiments to be in the order of 10−15 to 10−19 cm2 s−1.
Hydranencephaly following carbon monoxide poisoning during pregnancy: An uncommon and potentially fatal complication in infant
Authors: Hager Barakizou 
Published: June 2023

AbstractBackgroundHydranencephaly is a rare malformation of the brain system with an incidence of 0.5 per 1000 births. Its principal etiologies are bilateral occlusion of the internal carotid arteries and congenital infections.CaseWe reported an uncommon case of hydranencephaly diagnosed in 50‐day old infant and attributable to carbon monoxide (CO) poisoning during the first trimester of pregnancy.ConclusionsWe recommend a prompt diagnosis and management of CO poisoning in pregnant women since it can dramatically affect both the fetus and mother.
The real reason why ATP hydrolysis is spontaneous at pH > 7: It's (mostly) the proton concentration!
Authors: Silverstein Todd P. 
Published: June 2023

AbstractCommon wisdom holds that ATP hydrolysis is spontaneous because of the weakness of its phosphoanhydride bonds, electrostatic repulsion within the polyanionic ATP4− molecule, and resonance stabilization of the inorganic phosphate and ADP products. By examining the pH‐dependence of the hydrolysis Gibbs free energy, we show that in fact, above pH 7, ATP hydrolysis is spontaneous due mainly to the low concentration of the H+ that is released as product. Hence, ATP is essentially just an electrophilic target whose attack by H2O causes the acidity of the water nucleophile to increase dramatically; the spontaneity of the resulting acid ionization supplies much of the released Gibbs free energy. We also find that fermentation lowers pH not due to its organic acid products (e.g., lactic, acetic, formic, or succinic acids), but again, due to the H+ product of ATP hydrolysis.
Blended/flipped biology classes during COVID‐19
Authors: Mostafa Iman , Kakarougkas Andreas 
Published: June 2023

AbstractHigher education has been significantly affected by the COVID‐19 pandemic, disrupting universities worldwide. Unexpectedly, the global academic community was forced to transition to remote and online learning. In many cases, fragilities in the systems of the higher education institutions were exposed, pointing to the need for investment in developing more digital solutions, infrastructure, and teaching modalities. In the post‐COVID‐19 era, the development and adoption of robust pedagogical modalities is crucial to provide the education systems with effective strategies for designing high‐quality courses. Since 2008, MOOCs have been widely used to support billions of students worldwide with flexible, accessible, and high‐quality learning experiences. This study attempts to investigate the effectiveness of adopting the MOOC‐based flipped approach. We present findings and lessons learned from adopting this approach in two different biology classes using the MITx online materials. Findings on students' preparedness, students' performance, MOOCs integration evaluation, and during‐pandemic approach assessment are also explained. In general, the results indicated that students favored the overall experience and the implemented approach. Since the online learning is currently at an evolving stage in Egypt, we believe this study's results might be beneficial for policymakers and Egyptian education institutions in designing strategies to improve the education process.