"AquaF" Building Blocks for Water-Compatible SN2 18F-Fluorination of Small-Molecule Radiotracers.

Despite the widespread use of hydrophilic building blocks to incorporate 18F and improve tracer pharmacokinetics, achieving effective leaving group-mediated nucleophilic 18F-fluorination in water (excluding 18F/19F-exchange) remains a formidable challenge. Here, we present a water-compatible SN2 leaving group-mediated 18F-fluorination method employing preconjugated "AquaF" (phosphonamidic fluorides) building blocks. Among 19 compact tetracoordinated pentavalent P(V)-F candidates, the "AquaF" building blocks exhibit superior water solubility, sufficient capacity for 18F-fluorination in water, and excellent in vivo metabolic properties. Two nitropyridinol leaving groups, identified from a pool of leaving group candidates that further enhance the precursor water solubility, enable 18F-fluorination in water with a 10-2 M-1 s-1 level reaction rate constant (surpassing the 18F/19F-exchange) at room temperature. With the exergonic concerted SN2 18F-fluorination mechanism confirmed, this 18F-fluorination method achieves ∼90% radiochemical conversions and reaches a molar activity of 175 ± 40 GBq/µmol (using 12.2 GBq initial activity) in saline for 12 "AquaF"-modified proof-of-concept functional substrates and small-molecule 18F-tracers. [18F]AquaF-Flurpiridaz demonstrates significantly improved radiochemical yield and molar activity compared to 18F-Flurpiridaz, alongside enhanced cardiac uptake and heart/liver ratio in targeted myocardial perfusion imaging, providing a comprehensive illustration of "AquaF" building blocks-assisted water-compatible SN2 18F-fluorination of small-molecule radiotracers.

Positron Emission Tomography of Nitric Oxide by a Specific Radical-Generating Dihydropyridine Tracer.

Nitric oxide (NO) plays a pivotal role as a biological signaling molecule, presenting challenges in its specific detection and differentiation from other reactive nitrogen and oxygen species within living organisms. Herein, a 18F-labeled (fluorine-18, t1/2 = 109.7 min) small-molecule tracer dimethyl 4-(4-(4-[18F]fluorobutoxy)benzyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate ([18F]BDHP) is developed based on the dihydropyridine scaffold for positron emission tomography (PET) imaging of NO in vivo. [18F]BDHP exhibits a highly sensitive and efficient C-C cleavage reaction specifically triggered by NO under physiological conditions, leading to the production of a 18F-labeled radical that is readily retained within the cells. High uptakes of [18F]BDHP are found within and around NO-generating cells, such as macrophages treated with lipopolysaccharide or benzo(a)pyrene. MicroPET/CT imaging of arthritic animal model mice reveals distinct tracer accumulation in the arthritic legs, showcasing a higher distribution of NO compared with the control legs. In summary, a specific radical-generating dihydropyridine tracer with a unique radical retention strategy has been established for the marking of NO in real-time in vivo.

Prospective association between social isolation, loneliness and lung function among Chinese middle-aged and older adults.

OBJECTIVE: Previous research has highlighted a heightened occurrence of social isolation and loneliness in older adults diagnosed with chronic lung diseases. Nevertheless, there exists a dearth of studies that have explored the influence of impoverished social relationships on lung function. This study aimed to examine the longitudinal association between social isolation, loneliness and lung function over 4 years among middle-aged and older Chinese adults. METHODS: This study employed two waves (2011 and 2015) of data from the China Health and Retirement Longitudinal Study (CHARLS). The analysis was limited to participants aged 45 years and above and stratified based on gender (3325 men and 3794 women). The measurement of peak expiratory flow (PEF) served as an indicator for assessing lung function. Lagged dependent variable regression models, accounting for covariates, were employed to explore the relationship between baseline social isolation and loneliness and the subsequent PEF. RESULTS: For women, social isolation was significantly associated with the decline in PEF at follow-up (ß = -.06, p < .001) even after adjusting for all covariates; no significant correlation was observed between loneliness and PEF. Among men, there was no significant association found between either social isolation or loneliness and PEF. CONCLUSIONS: Social isolation is prospectively associated with worse lung function in middle-aged and older Chinese women but not men. The results highlight the importance of promoting social relationships in public health initiatives, especially in groups that are more vulnerable.

Mismatched Supramolecular Interactions Facilitate the Reprocessing of Super-Strong and Ultratough Thermoset Elastomers.

Thermoset elastomers have been extensively applied in many fields because of their excellent mechanical strengths and durable characteristics, such as an excellent chemical resistance. However, in the context of environmental issues, the nonrecyclability of thermosets has become a major barrier to the further development of these materials. Here, a well-tailored strategy is reported to solve this problem by introducing mismatched supramolecular interactions (MMSIs) into a covalently cross-linked poly(urethane-urea) network with dynamic acylsemicarbazide moieties. The MMSIs significantly strengthen and toughen the thermoset elastomer by effectively dissipating energy and resisting external stress. In addition, the elastomer recycling efficiency is improved 2.7-fold due to the superior reversibility of the MMSIs. The optimized thermoset elastomer features outstanding characteristics, including an ultrahigh tensile strength (110.8 MPa), an unprecedented tensile toughness (1245.2 MJ m-3), as well as remarkable resistance to chemical media, creep, and damage. Most importantly, it exhibits an extraordinary multirecyclability, and the 4th recycling efficiency remains close to 100%. This scalable method promotes the development of thermosets with both high performance and excellent recyclability, thereby providing valuable guidance for addressing the issue of nonrecyclability from a molecular design standpoint.

Extended Battery Compatibility Consideration from an Electrolyte Perspective.

The performance of electrochemical batteries is intricately tied to the physicochemical environments established by their employed electrolytes. Traditional battery designs utilizing a single electrolyte often impose identical anodic and cathodic redox conditions, limiting the ability to optimize redox environments for both anode and cathode materials. Consequently, advancements in electrolyte technologies are pivotal for addressing these challenges and fostering the development of next-generation high-performance electrochemical batteries. This review categorizes perspectives on electrolyte technology into three key areas: additives engineering, comprehensive component analysis encompassing solvents and solutes, and the effects of concentration. By summarizing significant studies, the efficacy of electrolyte engineering is highlighted, and the review advocates for further exploration of optimized component combinations. This review primarily focuses on liquid electrolyte technologies, briefly touching upon solid-state electrolytes due to the former greater vulnerability to electrode and electrolyte interfacial effects. The ultimate goal is to generate increased awareness within the battery community regarding the holistic improvement of battery components through optimized combinations.

A Healable Quasi-Solid Polymer Electrolyte with Balanced Toughness and Ionic Conductivity.

Solid polymer electrolytes (SPEs) have garnered extensive attention as potential alternatives to traditional liquid electrolytes, primarily due to their prowess in curbing lithium dendrite formation and preventing electrolyte leaks. The quest for SPEs that are both mechanically robust and exhibit superior ionic conductivity has been vigorous. However, achieving a harmonious balance between these two attributes remains a significant challenge. In this study, we introduce a novel quasi-solid electrolyte, ingeniously crafted from a poly(urethane-urea) network, enriched with lithium salts and plasticizers. This innovative composition not only boasts remarkable toughness but also ensures commendable ionic conductivity. Our post-gelation method yields gel polymer electrolytes that undergo rigorous evaluation, leading to an optimized version that stands out with its exceptional room-temperature ionic conductivity (2.94×10-4 S cm-1) and outstanding toughness (11.9 MJ m-3). Moreover, it demonstrates a broad electrochemical window (4.73 V), remarkable stability across a 600-hour cycle test, a high capacity retention exceeding 80 % after 100 cycles at 0.2 C, and a noteworthy self-healing capability. This quasi-solid polymer electrolyte emerges as a promising contender to replace current liquid electrolyte solutions.

A Comprehensive Evaluation of Battery Technologies for High-Energy Aqueous Batteries.

Aqueous batteries have garnered significant attention in recent years as a viable alternative to lithium-ion batteries for energy storage, owing to their inherent safety, cost-effectiveness, and environmental sustainability. This study offers a comprehensive review of recent advancements, persistent challenges, and the prospects of aqueous batteries, with a primary focus on energy density compensation of various battery engineering technologies. Additionally, cutting-edge high-energy aqueous battery designs are emphasized as a reference for future endeavors in the pursuit of high-energy storage solutions. Finally, a dual-compatibility battery configuration perspective aimed at concurrently optimizing cycle stability, redox potential, capacity utilization for both anode and cathode materials, as well as the selection of potential electrode candidates, is proposed with the ultimate goal of achieving cell-level energy densities exceeding 400 Wh kg-1.

Precipitated Iodine Cathode Enabled by Trifluoromethanesulfonate Oxidation for Cathode/Electrolyte Mutualistic Aqueous Zn-I Batteries.

Aqueous Zn-I batteries hold great potential for high-safety and sustainable energy storage. However, the iodide shuttling effect and the hydrogen evolution reaction that occur in the aqueous electrolyte remain the main obstacles for their further development. Herein, the design of a cathode/electrolyte mutualistic aqueous (CEMA) Zn-I battery based on the inherent oxidation ability of aqueous trifluoromethanesulfonate ((OTf)- ) electrolyte toward triiodide species is presented. This results in the formation of iodine sediment particles assembled by fine iodine nanocrystals (≈10 nm). An iodine host cathode with high areal iodine loading is realized via a spontaneous absorption process that enriched redox-active iodine and iodide species from aqueous electrolyte onto nanoporous carbon based current collector. By tuning iodide redox process and suppressing competitive hydrogen evolution reaction, the assembled CEMA Zn-I batteries demonstrate a remarkable capacity retention of 76.9% over 1000 cycles at 0.5 mA cm-2 . Moreover, they exhibit a notable rate capability, with a capacity retention of 74.6% when the current density is increased from 0.5 to 5.0 mA cm-2 . This study demonstrates the feasibility of using the oxidation effect to repel redox-active species from the electrolyte to the cathode, paving a new avenue for high-performance aqueous Zn-I batteries.

FGFs function in regulating myoblasts differentiation in spotted sea bass (Lateolabrax maculatus).

Fibroblast growth factors (FGFs) are a family of structurally related peptides that regulate processes such as cell proliferation, differentiation, and damage repair. In our previous study, fibroblast growth factor receptor 4 (fgfr4) was detected in the most significant quantitative trait loci (QTL), when identified of QTLs and genetic markers for growth-related traits in spotted sea bass. However, knowledge of the function of fgfr4 is lacking, even the legends to activate the receptor is unknown in fish. To remedy this problem, in the present study, a total of 33 fgfs were identified from the genomic and transcriptomic databases of spotted sea bass, of which 10 were expressed in the myoblasts. According to the expression pattern during myoblasts proliferation and differentiation, fgf6a, fgf6b and fgf18 were selected for further prokaryotic expression and purification. The recombinant proteins FGF6a, FGF6b and FGF18 were found to inhibit myoblast differentiation. Overall, our results provide a theoretical basis for the molecular mechanisms of growth regulation in economic fish such as spotted sea bass.

Supramolecular Ionogels for Use in Locating Damage to Underwater Infrastructure.

The capacity to self-detect and locate damage to underwater infrastructure in emergencies is vital, as materials and technologies that securely facilitate energy and information transmission are crucial in several fields. Herein, the development of a multifunctional supramolecular ionogel (SIG) and SIG-based devices for use in detecting and locating damage to underwater infrastructure is reported. The SIG is fabricated via the single-step photoinitiated copolymerization of hydroxy and fluorinated monomers in a fluorinated ionic liquid. Hydrogen-bond/ion-dipole-interaction synergy ensures that the SIG is highly ionically conductive and extremely mechanically strong, with underwater self-healing and adhesion properties. It can be used as an underwater ionic cable to provide reporting signals via changes in strain; furthermore, SIG-based devices can be fixed to underwater infrastructure to locate damage via resistance monitoring. The SIG can also be attached to the human body for use in underwater communication, thereby safeguarding maintenance personnel while repairing underwater infrastructure. This study provides a novel pathway for developing supramolecular materials and devices.

The combined effect of pit and fissure sealant application and oral health education on oral health status of children aged 6-9 years: a 12-month follow-up study in Northeast China.

BACKGROUND: Children aged 6-9 years are vulnerable to dental caries due to age-related limitations and a lack of adequate knowledge regarding oral health and hygiene practices. This study aimed to establish a cohort of children aged between 6 and 9 years and conducted a 12-month follow-up to examine the combined effect of pit and fissure sealant (PFS) application and oral health education on their oral health status. METHODS: A cohort study with 12-month follow-up was conducted in Liaoning province, China. A multi-stage stratified cluster sampling approach was employed in the study. The enrolled 6- to 9-year-old children were all from the selected primary schools, who had resided in the designated area for at least 6 months. Children who were unable to cooperate with the examiner or without informed consent from their guardians were excluded. Experienced dental professionals examined the oral health status of primary school children aged 6-9 years. All children and their guardians were mandated to complete a questionnaire (qualitative data) at the beginning of the study. In the experiment group, children underwent PFS application and chairside oral health education. Clinical examinations and questionnaire surveys were repeated at the 12-month follow-up. The chi-square test and binary logistic regression were conducted to investigate the potential risk factors associated with dental caries prevalence (dependent variable). Independent variables were items from the questionnaire (such as living place, parents' education level and children' birth weight). The significant variables identified in the chi-square tests were subsequently included in the binary logistic regression analysis. RESULTS: A total of 4,085 children aged 6-9 years were included in the study, with 1805 participants assigned to the experiment group and 2280 to the control group. At baseline, the caries rates of the experimental and control group were 77.95% and 80.35%, respectively without any statistically significant differences. However, at the 12-month follow-up, the caries rate in the experimental group (83.65%) was significantly lower than that in the control group (86.62%) (P < 0.05). The results from the binary logistic regression analysis indicated that parents with a college degree and children in the experimental group exhibited lower caries rates. Conversely, higher caries rates were associated with the consumption of sweet beverages and foods more than once a day and a lack of knowledge regarding the causes of caries (P < 0.05). CONCLUSIONS: In Liaoning, China, children aged 6 to 9 years exhibited a high prevalence of dental caries. Several factors, including the parent's education level, the frequency of consuming sweet beverages and foods, and the children's understanding of the cause of caries, significantly affected the caries prevalence rates. The implementation of PFS application and oral health education effectively reduce the caries rate among the surveyed children.

Fluorinated Interface Engineering toward Controllable Zinc Deposition and Rapid Cation Migration of Aqueous Zn-Ion Batteries.

Metallic zinc (Zn) is a highly promising anode material for aqueous energy storage systems due to its low redox potential, high theoretical capacity, and low cost. However, rampant dendrites/by-products and torpid Zn2+ transfer kinetics at electrode/electrolyte interface severely threaten the cycling stability, which deteriorate the electrochemical performance of Zn-ion batteries. Herein, an interfacial engineering strategy to construct alkaline earth fluoride modified metal Zn electrodes with long lifespan and high capacity retention is reported. The compact fluoride layer is revealed to guide uniform Zn stripping/plating and accelerate the transfer/diffusion of Zn2+ via Maxwell-Wagner polarization. A series of in situ and ex situ spectroscopic studies verified that the fluoride layer can guide uniform Zn stripping/plating. Electrochemical kinetics analyses reveal that positive effect on the removal of Zn2+ solvation sheath provided by fluoride layer. Meanwhile, this fluoride coating layer can act as a barrier between the Zn electrode and electrolyte, providing a high electrode overpotential toward hydrogen evolution reaction to hold back H2 evolution. Consequently, the fluoride-modified Zn anode exhibited a capacity retention of 88.2% after 4000 cycles under10 A g-1 . This work opens up a new path to interface engineering for propelling the exploration of advanced rechargeable aqueous Zn-ion batteries.

Highly Stereodivergent Synthesis of Chiral C4-Ester-Quaternary Pyrrolidines: A Strategy for the Total Synthesis of Spirotryprostatin A.

In this work, we disclose two sets of highly diastereo- and enantioselective [3 + 2] cycloadditions of iminoesters with various α-substituted acrylates, especially for sterically hindered and weakly activated α-aryl or alkyl-substituted acrylates and alkenal, alkynal, or unstable aliphatic aldehyde-derived iminoesters, catalyzed by the AgHMDS/DTBM-Segphos or Ag2O/CA-AA-Amidphos catalytic system, achieving the stereodivergent synthesis of chiral C4-ester-quaternary exo- or endo-pyrrolidines with high yields and excellent diastereo- and enantioselectivities (up to >99:1 dr and >99% ee). More importantly, the gram-scale synthetic exo-adduct displays significant applications in the aspect of realizing the total synthesis of the spirotryprostatin A alkaloid via nine steps in a 36% overall yield.

Development of Tough Thermoplastic Elastomers by Leveraging Rigid-Flexible Supramolecular Segment Interplays.

Supramolecular interactions facilitate the development of tough multifunctional thermoplastic elastomers. However, the fundamental principles that govern supramolecular toughening are barely understood, and the rational design to achieve the desired high toughness remains daunting. Herein, we report a simple and robust method for toughening thermoplastic elastomers by rationally tailoring hard-soft phase separation structures containing rigid and flexible supramolecular segments. The introduced functional segments with distinct structural rigidities provide mismatched supramolecular interactions to efficiently tune the energy dissipation and bear an external load. The optimal supramolecular elastomer containing aromatic amide and acylsemicarbazide moieties demonstrates a record toughness (1.2 GJ m-3 ), extraordinary crack tolerance (fracture energy 282.5 kJ m-2 ), an ultrahigh true stress at break (2.3 GPa), good elasticity, healing ability, recyclability, and impact resistance. The toughening mechanism is validated by testing various elastomers, confirming the potential for designing and developing super-tough supramolecular materials with promising applications in aerospace and electronics.

Advances in epidemiological status and pathogenesis of dental fluorosis.

Fluoride is commonly consider as a "double-edged sword" because low consumption of fluoride can effectively prevent dental caries, but excessive consumption of fluoride can cause fluorosis. Dental fluorosis (DF) is a characteristic feature of fluorosis in the oral cavity that is manifested as tooth color changes and evident enamel defect. Presently, the pathogenesis of DF remains unclear. Herein, we have summarized the research progress in the pathogenesis and mechanism of DF in the past 5 years.

Oral health status of students with visual or hearing impairments in Northeast China.

BACKGROUND: Visual or hearing impairments in students seriously affect their quality of life. The aim of this study was to identify oral hygiene status and its influencing factors on visual or hearing impairments in students in Northeast China. METHODS: This study was conducted in May 2022. A total of 118 visually impaired students and 56 hearing impaired students from Northeast China were included in this study via census. Oral examinations and questionnaire-based surveys of students and their teachers were conducted. The oral examinations included caries experience, prevalence of gingival bleeding and dental calculus. The questionnaires included three parts: Social demographics (residence, sex and race) and parents' educational level; Oral hygiene habits and medical treatment behaviors; Knowledge and attitudes towards oral health care. This questionnaire was selected from the Fourth China National Oral Health Survey and the reliability and validity of the questionnaire were previously tested. T tests, one-way ANOVA, χ2 tests and multivariate logistic analyses were conducted to evaluate the differences and dependent variables of dental caries. RESULTS: The prevalence of dental caries in visually impaired and hearing impaired students were 66.10% and 66.07%. The mean number of DMFT, prevalence of gingival bleeding and dental calculus in visually impaired students were 2.71 ± 3.06, 52.08% and 59.38%, respectively. The mean number of DMFT, prevalence of gingival bleeding and dental calculus in hearing impaired students were 2.57 ± 2.83, 17.86% and 42.86%, respectively. The results of the multivariate logistic analysis showed that fluoride use and parents' educational background had an impact on the caries experience of visually impaired students. The daily toothbrushing frequency and parents' educational background had an impact on the caries experience of hearing impaired students. CONCLUSIONS: The oral health situation of students with visual or hearing impairments remains severe. It is still necessary to promote oral and general health in this population.

18 F-Labeling Chemistry in Aqueous Media.

18 F-Labeled molecular tracers and subsequent positron emission tomography are indispensable molecular imaging tools in medical diagnosis and research. The preparation of 18 F-labeled molecular tracers involves critical steps such as the 18 F-labeling reaction, work-up, and 18 F-product purification, which are governed by 18 F-labeling chemistry. Since direct incorporation of 18 F in aqueous media exhibits many advantages in practice, this Review summarizes the existing 18 F-labeling methods in aqueous media, which are sorted by atoms forming chemical covalent bonds with F. The Review is focused on the respective reaction mechanism, the water effect and the applications of these methods for the development of 18 F-radiopharmaceuticals. The research progress on aqueous nucleophilic labeling methods using [18 F]F- as the 18 F source has been mainly discussed.

Cytochrome P450 superfamily in spotted sea bass: Genome-wide identification and expression profiles under trichlorfon and environmental stresses.

Cytochrome P450s (CYPs), as one of the most diverse enzyme superfamilies in nature, play critical functions in antioxidant reactions against endogenous and exogenous compounds. In this study, we performed genome-wide characterization of CYP superfamily members and analyzed their expression patterns under several abiotic stresses in spotted sea bass, which is known as an economically important fish species in the Chinese aquaculture industry. A total of 55 CYP genes were identified and divided into 17 families within 10 clans. The analysis of phylogeny, gene structure, and syntenic relationships provided evidence for the evolution of CYP genes and confirmed their annotation and orthology. The expression of CYP genes was examined in the liver during trichlorfon stress using quantitative real-time PCR. The results showed that 20 tested CYP genes displayed significant mRNA expression changes, indicating that they may play crucial roles in the metabolism of trichlorfon and can be potential biomarkers for trichlorfon pollution. Moreover, by screening transcriptomic databases, 10, 3 and 19 CYP genes exhibited differential expression patterns in response to hypoxia, alkalinity and heat stress, respectively. Taken together, this study provided insights into the regulation of CYP genes by toxicological and environmental stresses, laid basis for extensive functional studies of the CYP superfamily in spotted sea bass and other teleost species.

Protocol for preparation and characterization of CO2-responsive foaming.

Despite the unique switching characteristics of CO2-responsive foaming, its stability remains questionable. In this protocol, we describe steps to synthesize a stable CO2-responsive foam by adding the preferably selected hydrophilic nanoparticle N20 into the surfactant C12A. We detail the selection of the most suitable nanoparticles for the surfactant by measuring the foaming volume and half-life of the dispersion. The protocol can be extended to manufacture with other types of responsive foams (e.g., light responsive foams, magnetic responsive foams). For complete details on the use and execution of this protocol, please refer to Li et al. (2022).1.

Temporary Actuation of Bilayer Polymer Hydrogels Mediated by the Enzymatic Reaction.

Most soft actuators have the ability of monotonic responsiveness. That is, there is only one response action after being stimulated once. In this work, a temporarily responsive bilayer hydrogel actuator is designed and fabricated by combining a tertiary amine-containing pH-responsive layer and a urease-containing non-responsive layer. The hydrogel actuator can achieve programed deformation and recovery driven by chemical fuels (i.e., acidic urea solutions), which is essentially regulated by rapid acidification and slow enzymatic production of ammonia for recovering the pH of the system. The actuation extent and duration can be simply controlled by the fuel levels, and the repeated actuations are also possible via refueling. Furthermore, we fabricate several hydrogel devices that can display specific patterns or lift an item. This enzymatic method shows new possibilities to control the temporary actuation of polymer hydrogels potentially useful in many fields such as soft robotics, biomimetic devices, and environmental sensing.