bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinetic Study of Alkaline Hydrolysis of Substituted Phenyl Tosylates. XXII. Variation of Ortho Substituent Effect with Solvent
Authors: Nummert Vilve , Piirsalu Mare , Lepp Marika , Mäemets Vahur , Koppel Ilmar 
Published: March 2005

The second-order rate constants k (dm3 mol-1 s-1) for the alkaline hydrolysis of meta-, para-, and ortho-substituted phenyl tosylates 4-CH3C6H4SO2OC6H4-X in aqueous 0.5 M Bu4NBr have been measured spectrophotometrically in a wide temperature range. The log k values for ortho-substituted derivatives at various temperatures together with meta- and para-substituted derivatives were analyzed using the modified Fujita-Nishioka equation log km,p,ortho = c0 + c1(m,p,ortho)σ° + c2(ortho)σI + c3(1/T) + c4(m,p,ortho)(1/T)σ° + c5(ortho)(1/T)σI. In order to study the dependence of substituent effects, especially ortho inductive and resonance terms on different solvent parameters, the following equation was used: ∆log km,p,ortho = c0 + c1(m,p,ortho)σ° + c2(ortho)σI + c3∆E + c4∆Y + c5∆P + c6(m,p,ortho)∆Eσ° + + c7(m,p,ortho)∆Yσ° + c8(m,p,ortho)∆Pσ° + c9(ortho)∆EσI + c10(ortho)∆YσI + c11(ortho)∆PσI. ∆log k = log kX - log kH, σ° and σI, are the Taft polar and inductive substituent constants, E, Y and P, are the solvent electrophilicity, polarity and polarizability parameters, respectively. In data treatment ∆E = ES - EH2O, ∆Y = YS - YH2O, ∆P = PS - PH2O were used. The solvent electrophilicity was found to be the main factor responsible for changes in the ortho, para, and meta polar substituent effects with medium. The variation of the ortho inductive term with the solvent electrophilicity ES was found to be twice smaller than that for para substituents, while the ortho resonance term appeared to vary with solvent nearly similarly to that for para substituents. The ortho effect caused by the supplementary inductive effect from ortho position was found to disappear in a solvent whose electrophilic solvating power is comparable to pure DMSO (E ≈ 4).
Development of Ultrathin Polymer Films and Their Characteristics in Two Dimensions
Authors: Ito Shinzaburo , Mabuchi Michiaki , Sato Nobuhiro , Aoki Hiroyuki 
Published: March 2005

Abstract
Nanostructures and properties of ultrathin polymer films prepared by repeated deposition of monolayers have been investigated with emphasis on single chain morphology in two dimensions. The particular characteristics of ultrathin films were successfully revealed by novel optical microscopy and fluorescence spectroscopy techniques. A single polymer chain, which is confined into a two-dimensional plane, takes a contracted conformation, being segregated from other chains in the monolayer. Unlike three dimensional bulk polymers, there is little entanglement of polymer chains even for large molecular weight samples. These characteristics at the molecular level result in the entropy relaxation of individual chains with a small activation energy of diffusion, when the segmental motions are allowed at elevated temperatures. These understandings of structures and properties in two dimensions are indispensable for fabrication and application of polymeric thin films because the fine structures in low dimensions play critical roles in the production of advanced functions.
Dendrimer Effects on Intermolecular Energy-Transfer of Photoexcited Triplet States of Dendritic Multiporphyrin Arrays and Electron Transfer vs Fullerene[60]
Authors: Luo Hongxia , Choi Myung-Seok , Araki Yasuyuki , Ito Osamu , Aida Takuzo 
Published: March 2005

Abstract
Photochemical and photophysical properties of the triplet excited states of dendritic multiporphyrins arrays (nPZn, n = 1, 3, and 7) have been investigated by measuring the nanosecond transient absorption spectra in the visible and near-IR regions with changing the generation number. Intermolecular triplet–triplet annihilation rates decrease with the dendrimer generation, which was interpreted on a proposed kinetic model assuming that the excited triplet energy almost localizes in one PZn unit in nPZn. In the presence of C60, intermolecular electron-transfer takes place via the excited triplet states of nPZn (3nPZn*), yielding the cation radical of nPZn (nPZn•+) and the anion radical of C60 (C60•−) in PhCN. Deceleration of the electron-transfer rate-constants from 1PZn to 3PZn and the acceleration from 3PZn to 7PZn were observed, in which the latter tendency was interpreted by considering an increase in effective encounter radius for 37PZn*. The observed small change of the rate constants for back electron transfer between the oppositely charged species with the dendrimer generation was also reasonably interpreted by taking a smaller effective radius due to electrostatic attraction into consideration. Dendrimer generation effect was also observed for the intermolecular hole-transfer process.
Synthesis, Structure, and In Vitro and In Vivo Insulinomimetic Activities of the Zinc(II)–6-Ethylpicolinate Complex
Authors: Kojima Yoshitane , Yoshikawa Yutaka , Ueda Eriko , Kishimoto Noriko , Tadokoro Makoto , Sakurai Hiromu 
Published: March 2005

Abstract
A new zinc(II) complex, bis(6-ethylpicolinato)zinc(II) ([Zn(6epa)2]), was prepared by introducing an electron-donating ethyl group on the pyridine ring. [Zn(6epa)2] was crystallized from an aqueous solution, and its structure was determined by X-ray analysis, in which both carboxylate O and pyridine N atoms of 6epa coordinated to a Zn2+ ion, forming a distorted trigonal bipyramidal geometry with two 6epa and a water. In an in vitro evaluation with regard to the inhibition of free fatty acid (FFA) release from isolated rat adipocytes in the presence of epinephrine, the insulinomimetic activity (IC50 = 0.37 mM) of [Zn(6epa)2] was found to be higher than that (0.64 mM) of the bis(picolinato)Zn(II) complex in terms of the IC50 value. When the [Zn(6epa)2] complex was injected daily at a dose of 3 mg Zn/kg of body weight of KK-Ay mice for 14 d, the blood glucose levels of the mice were lowered to approximately 200 mg/dL (11.1 mM) from 400–500 mg/dL (22.2–27.8 mM). Based on the results, the [Zn(6epa)2] complex was proposed to be a new candidate for treating type-2 diabetes in animals. However, it was proven that [Zn(6mpa)2] has an advantage in having no side effect over [Zn(6epa)2], when the effects on their serum parameters were considered.
Rhodium-Catalyzed Acylation of Vinylsilanes with Acid Anhydrides
Authors: Yamane Motoki , Uera Kazuyoshi , Narasaka Koichi 
Published: March 2005

Abstract
A catalytic acylation of vinylsilane with acid anhydride is accomplished by the use of [RhCl(CO)2]2, in which the transmetalation between vinylsilane and rhodium(I) carbonyl complex plays a key role. The application of this acylation reaction to (1-acyloxyvinyl)silanes provides synthetic methods for α-acyloxy enones, α-diketones, and their derivatives.
Synthesis, Structure, and Information about Molecular Weight of Thiophene Homopolymers, Copolymers of 2,5-Thienylene and 2,4-Thienylene, and Their Soluble Nitrates
Authors: Abe Masahiro , Abdul Karim S M , Yamaguchi Isao , Kuroda Shin-ichi , Kubota Kenji , Yamamoto Takakazu 
Published: March 2005

Abstract
Dehalogenative homopolymerization and copolymerization of 2,5-dibromothiophene and 2,4-dibromothiophene were carried out by using a Ni(II) complex catalyst. Nitration of the polymers gave soluble nitrated polymers which provided information about the degree of polymerization (DP = 58–88) of the original polymers. Chemical properties of the polymers and their nitrates are reported.
Antioxidant Nanozyme‐Engineered Mesenchymal Stem Cells for In Vivo MRI Tracking and Synergistic Therapy of Myocardial Infarction
Authors: Le Wenjun , Sun Zeyi , Li Tieyan , Cao Hao , Yang Chuanxue , Mei Tianxiao , Zhang Laihai , Wang Yibing , Jia Wenwen , Sun Wen , Hu Yihui , Liu Zhongmin 
Published: February 2024

AbstractCell therapy is a promising approach for myocardial infarction (MI) treatment. However, this strategy is often restricted by the harsh microenvironment of MI, such as excess ROS, high oxidative stress, inflammation, etc., and thus decreases the curative effect. Additionally, the distribution, migration, and homing of the transplanted stem cells is ambiguous, which also becomes a bottleneck for clinical translation. To address these challenges, herein, a versatile antioxidant nanozyme is designed by polymerically modifying dopamine (PDA) onto the surface of Mn3O4. The obtained nanozyme acts as an efficient SOD mimic, eliminating ROS, relieving oxidative stress, and reducing inflammation to improve the MI microenvironment. Simultaneously, Mn3O4@PDA serves as an excellent MRI contrast agent for tracking MSCs. Then, MSCs are engineered with Mn3O4@PDA nanozyme via endocytosis to form Mn3O4@PDA‐MSCs (Abbr. E‐MSCs), which possess superior viability, migration and homing ability compared to normal MSCs. Furthermore, E‐MSCs exhibit superior anti‐oxidant and anti‐inflammatory activity, thereby enhancing the therapeutic efficacy of MSCs. Finally, the in vivo MRI tracking and synergistic therapy potential of E‐MSCs is explored in MI model mice. Overall, this work provides a strategy to combine antioxidant activity and imaging properties of nanozymes to simultaneously facilitate imaging tracking of stem cells and improve MI treatment.
Hydrogel Enabled Dual‐Shielding Improves Efficiency and Stability of BiVO4 Based Photoanode for Solar Water Splitting
Authors: Zhang Qian , Wang Yifan , Zhang Wenran , Yao Xiangdong , Liang Qijie 
Published: February 2024

AbstractPhotoelectrochemical solar to hydrogen conversion is a promising approach to solve energy and environmental problems. One of the paramount challenges to overcome is to achieve high solar to hydrogen efficiency while retaining stable service behavior without photocorrosion of the photoanode. In this study, a hydrogel‐enabled dual‐shielding (FeCoOx/PAAM) strategy is reported to improve efficiency and suppress photocorrosion of photoanode during solar water splitting especially in a high‐intensity illumination. Anodic photocorrosion of BiVO4 photoanodes involves the chemical and physical construction changes under the conditions of light field, electric field, and electrolyte. The utilization of FeCoOx/PAAM on BiVO4 inhibits the improvement of oxygen evolution reaction kinetics, bubble dynamics, and blocking ion dissolution diffusion, which effectively suppresses anodic photocorrosion and simultaneously improves efficiency of BiVO4 photoanode. The improved BiVO4/FeCoOx/PAAM photoanode shows a superior photocurrent density of 19.88 mA cm−2 at 1.23 V versus RHE, and a high charge separation efficiency of 98% with enhanced stability over 60 h (300 mW cm−2). This study contributes to developing a universal method of photoanode protection to anti‐photocorrosion, facilitating the development of high‐efficiency, high‐stability, and pollution‐free hydrogen production.
Hydrogen‐Associated Multiple Electronic Phase Transitions for d‐Orbital Transitional Metal Oxides: Progress, Application, and Beyond
Authors: Zhou Xuanchi , Li Haifan , Jiao Yongjie , Zhou Guowei , Ji Huihui , Jiang Yong , Xu Xiaohong 
Published: February 2024

AbstractHydrogen‐associated electron doping Mottronics within d‐orbital transitional metal oxides (TMOs) opens up a new paradigm to explore exotic physical phenomena that enable promising applications such as artificial intelligence, Mottronic/iontronic devices, energy conversions, bio‐electronic sensing, and smart windows. Although remarkable progress is achieved over the past decade, systematic and in‐depth insights into hydrogen‐associated exotic physical phenomena within TMOs are still lacking. Herein, this review delivers a comprehensive and timely picture of hydrogen‐triggered electronic phase transitions within TMOs, covering the hydrogenation strategies, research progress, underneath mechanisms, multidisciplinary applications, and beyond. Furthermore, of particular interest, the hydrogenation or protonation enables the possibility of exploring the novel electronic phase and exotic physical properties within TMOs via breaking the intrinsic coupling in the charge, spin, lattice, and orbital degrees of freedom. Beyond that, a broader vision is further cast into the cutting‐edge researching fields of the multifunctionality associated with hydrogenated TMOs and the role of hydrogen in filling‐controlled Mottronic transitions by using hydrogenation. As combined with the critical overview of the existing open questions and future prospects, this review is expected to provide useful guidance on the hydrogen‐associated electronic phase transitions within TMOs and further broaden the promising applications.
Recombinant Human Keratinocyte Growth Factor Ameliorates Cancer Treatment‐Induced Oral Mucositis on a Chip
Authors: Ly Khanh L. , Rajtboriraks May , Elgerbi Ahmed , Luo Xiaolong , Raub Christopher B. 
Published: February 2024

AbstractOral mucositis (OM) is a severe complication of cancer therapies caused by off‐target cytotoxicity. Palifermin, which is recombinant human keratinocyte growth factor (KGF), is currently the only mitigating treatment available to a subset of OM patients. This study used a previously established model of oral mucositis on a chip (OM‐OC) comprised of a confluent human gingival keratinocytes (GIE) layer attached to a basement membrane‐lined subepithelial layer consisting of human gingival fibroblasts (HGF) and human dermal microvascular endothelial cells (HMEC) on a stable collagen I gel. Cisplatin, radiation, and combined treatments are followed by a recovery period in the OM‐OC to determine possible cellular and molecular mechanisms of OM under effects of KGF. Cancer treatments affected the keratinocyte layer, causing death and epithelial barrier loss. Both keratinocytes and subepithelial cells died rapidly, as evidenced by propidium iodide staining. In response to radiation exposure, cell death occurred in the apical epithelial layer, predominantly, within 24h. Cisplatin exposure predominantly promoted death of basal epithelial cells within 32‐36h. Presence of KGF in OM‐OC protected tissues from damage caused by cancer treatments in a dose‐dependent manner, being more effective at 10 ng/mL. As verified by F‐actin staining and the Alamar Blue assay, KGF contributed to epithelial survival and induced proliferation of GIE and HGF as well as HMEC within 120h. When the expression of eighty inflammatory cytokines is evaluated at OM induction (Day 12) and resolution (Day 18) stages in OM‐OC, some cytokines are identified as potential novel therapeutic targets. In comparison with chemoradiation exposure, KGF treatment showed a trend to decrease IL‐8 and TNF‐a expression at Day 12 and 18, and TGF‐β1 at Day 18 in OM‐OC. Taken together, these findings support the utility of OM‐OC as a platform to model epithelial damage and evaluate molecular mechanisms following OM treatment.
PAA‐PU Janus Hydrogels Stabilized by Janus Particles and its Interfacial Performance During Hemostatic Processing
Authors: Fang Yan , Zheng Yanyan , Chi Chongyi , Jiang Sai , Qin Wanbang , Zhang Yicheng , Liu Haiqing , Chen Qinhui 
Published: February 2024

AbstractHydrogel is a very promising dressing for hemostasis and wound healing due to its good adhesion and long‐term moist environment. However, secondary injury caused by tissue adhesion due to homogeneous hydrogel cannot be ignored. The obvious interface existing in Janus hydrogel will weaken its asymmetric function. Here, a hierarchical adhesive polyacrylic acid–polyurushiol water–oil Janus hydrogel (JPs@PAA‐PU) without adhesive layer is fabricated by one‐pot method in the stabilization of polystyrene@silica‐siliver Janus particles (JPs). The morphological structure, mechanical properties, anisotropic chemical composition, and adhesion performance, in vivo, and in vitro hemostatic properties of Janus hydrogel are investigated. Result shows that the obtained Janus hydrogel possesses obvious compartmentalization in microstructure, functional groups, and chemical elements. Janus hydrogel is provided with asymmetric interfacial toughness with top 52.45 ± 2.29 Kpa and bottom 7.04 ± 0.88 Kpa on porcine liver. The adhesion properties of PAA side to tissue, red blood cells and platelets, promoting effect of PU side on coagulation cascade reaction and its physical battier endow Janus hydrogel with shorter hemostatic time and less blood loss than control group. It also exhibits excellent antibacterial effects against Escherichia coli and Staphylococcus aureus (>90%). Janus hydrogel possesses biosafety, providing safety guarantee for clinical applications in the future.
Frontiers in Photoelectrochemical Catalysis: A Focus on Valuable Product Synthesis
Authors: Sendeku Marshet Getaye , Shifa Tofik Ahmed , Dajan Fekadu Tsegaye , Ibrahim Kassa Belay , Wu Binglan , Yang Ying , Moretti Elisa , Vomiero Alberto , Wang Fengmei 
Published: February 2024

AbstractPhotoelectrochemical (PEC) catalysis provides the most promising avenue for producing value‐added chemicals and consumables from renewable precursors. Over the last decades, PEC catalysis, including reduction of renewable feedstock, oxidation of organics, and activation and functionalization of C─C and C─H bonds, are extensively investigated, opening new opportunities for employing the technology in upgrading readily available resources. However, several challenges still remain unsolved, hindering the commercialization of the process. This review offers an overview of PEC catalysis targeted at the synthesis of high‐value chemicals from sustainable precursors. First, the fundamentals of evaluating PEC reactions in the context of value‐added product synthesis at both anode and cathode are recalled. Then, the common photoelectrode fabrication methods that have been employed to produce thin‐film photoelectrodes are highlighted. Next, the advancements are systematically reviewed and discussed in the PEC conversion of various feedstocks to produce highly valued chemicals. Finally, the challenges and prospects in the field are presented. This review aims at facilitating further development of PEC technology for upgrading several renewable precursors to value‐added products and other pharmaceuticals.
Activating CD8+ T Cells by Pt(IV) Prodrug‐Based Nanomedicine and aPD‐L1 Antibody for Enhanced Cancer Immunotherapy
Authors: Wang Bin , Zhou Jingyu , Li Ruitong , Tang Dongsheng , Cao Zheng , Xu Chun , Xiao Haihua 
Published: February 2024

AbstractRecent years have witnessed substantial progress in cancer immunotherapy, specifically T cell‐based therapies. However, the application of T cell therapies has been primarily limited to hematologic malignancies, with limited success in the treatment of solid tumors. The main challenge in treating solid tumor is immune escape, which is characterized by reduced antigenicity, diminished immunogenicity, and the development of suppressive tumor immune microenvironments. To address these obstacles and restore T cell‐mediated anti‐tumor responses, a novel nanoparticle formulation known as PRA@Oxa‐c16 is developed. This innovative approach combines retinoic acid and Pt(IV) to specifically target and overcome immune escape. Notably, the therapeutic efficacy of PRA@Oxa‐c16 primarily relies on its ability to induce anti‐tumor T cell responses, in contrast to the cytotoxicity associated with conventional chemotherapeutic agents. When combined with an immune checkpoint blockade, anti‐programmed death‐ligand 1 antibody, PRA@Oxa‐c16 effectively eliminates solid tumors and induces immune memory responses, which prevent tumor metastasis and recurrence. This promising approach holds great potential for enhancing the treatment of solid tumors with T cell‐based immunotherapy.
C−N Coupling between Aryl Azides and Cyclopropanols by Photoredox/Copper Dual Catalysis
Authors: Lin Wu‐Jie , Wang Yu‐Zhao , Yu Wei 
Published: February 2024

AbstractA photoredox/copper co‐catalyzed ring‐opening cross‐coupling of aryl azides with cyclopropanols has been developed with fac‐Ir(ppy)3 as the photocatalyst. The reaction involves intermediacy of the anilino radical generated through reduction of the azido group by fac‐Ir(ppy)3* and [CuII]‐enabled oxidative ring‐opening of the cyclopropanol. An array of β‐aminoketone compounds were synthesized under redox‐neutral conditions by using this method.
Phosphorylation of AGO2 by TBK1 Promotes the Formation of Oncogenic miRISC in NSCLC
Authors: Zhao Xian , Cao Yingting , Lu Runhui , Zhou Zihan , Huang Caihu , Li Lian , Huang Jiayi , Chen Ran , Wang Yanli , Huang Jian , Cheng Jinke , Zheng Junke , Fu Yujie , Yu Jianxiu 
Published: February 2024

AbstractNon‐small‐cell lung cancer (NSCLC) is a highly lethal tumor that often develops resistance to targeted therapy. It is shown that Tank‐binding kinase 1 (TBK1) phosphorylates AGO2 at S417 (pS417‐AGO2), which promotes NSCLC progression by increasing the formation of microRNA‐induced silencing complex (miRISC). High levels of pS417‐AGO2 in clinical NSCLC specimens are positively associated with poor prognosis. Interestingly, the treatment with EGFR inhibitor Gefitinib can significantly induce pS417‐AGO2, thereby increasing the formation and activity of oncogenic miRISC, which may contribute to NSCLC resistance to Gefitinib. Based on these, two therapeutic strategies is developed. One is jointly to antagonize multiple oncogenic miRNAs highly expressed in NSCLC and use TBK1 inhibitor Amlexanox reducing the formation of oncogenic miRISC. Another approach is to combine Gefitinib with Amlexanox to inhibit the progression of Gefitinib‐resistant NSCLC. This findings reveal a novel mechanism of oncogenic miRISC regulation by TBK1‐mediated pS417‐AGO2 and suggest potential therapeutic approaches for NSCLC.
Adaptation of oat genotypes in organic and conventionally managed fields in the northwestern Himalayas
Authors: Sanadya Sanjay Kumar , Sood Vinod Kumar , Sharma Gaurav , Enyew Muluken , Katna Gopal 
Published: February 2024

AbstractDeveloping stable and high‐yielding crop varieties is crucial for sustainable agriculture. The present study investigated genotype × environment interactions (GEIs) in 96 oat (Avena sativa L.) genotypes across five environments (year–production system combinations) using an alpha lattice design. Additive main effect and multiplicative interaction (AMMI) analysis revealed significant genotype, environment, and GEI effects on the studied traits. The oat genotypes were grouped into four distinct clusters and even genotypes from the same source were grouped into different clusters, indicating a wide range of diversity. Stability indices have highlighted genotypes coded as G33, G4, and G5 as the most stable across environments. Specifically, concerning seed yield, the AMMI analysis identified G33, G4, G5, and G82 as highly stable genotypes. Moreover, the study observed specific adaptations, such as G29 in E1 (conventional system 2019–2020), G76 in E3 (conventional system 2020–2021), and G54 and G77 in E4 (organic system 2020–2021). The genotype and genotype × environment (GGE) biplot analysis unveiled that environment E3 (conventional system 2020–2021) emerged as the ideal environment, demonstrating the highest level of representativeness and discrimination. By utilizing the polygon view of the GGE biplot, the presence of two distinct mega‐environments (MEs; ME1 and ME2) was revealed in relation to seed yield. Within these MEs, genotypes coded as G2 and G38 in ME1 and G20, G72, G85, and G89 in ME2 exhibited specific adaptations. Furthermore, genotypes coded as G89, G95, and G82 exhibited both stability and high mean seed yield. By combining stability indices, AMMI, and GGE biplots, widely adapted genotypes have the potential to promote sustainable agricultural practices.