Search

Abstract 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) derivatives are typical catholytes in aqueous organic redox flow batteries (AORFBs), but reported lifetime of them is limited. We find that the increase of Hirshfeld charge decreases the Gibbs free energy change (ΔG) values of side reactions of TEMPO, a near-linear relationship, and then exacerbates their degradation. Here we predict and synthesize a TEMPO derivative, namely TPP-TEMPO, by analyzing the Hirshfeld charge. TPP-TEMPO, with the smallest Hirshfeld charge and highest ΔG, is an order of magnitude more stable than TMA-TEMPO (N,N,N-2,2,6,6-heptamethylpiperidinyl oxy-4-ammonium chloride, a control with the largest Hirshfeld charge and lowest ΔG). We further elaborate on their decomposition pathways, identify byproducts, and mitigate degradation by supporting electrolyte engineering. Finally, a TPP-TEMPO/BTMAP-Vi (1,1′-bis[3-(trimethylammonio)propyl]-4,4′-bipyridinium tetrachloride) cell achieves a capacity density of ~12 Ah L− 1 and a low capacity fade rate of 0.0018% per cycle (or 0.0067% per hour).

Abstract Rosa roxburghii Tratt, a valuable plant in China with long history, is famous for its fruit. It possesses various secondary metabolites, such as L-ascorbic acid (vitamin C), alkaloids and poly saccharides, which make it a high nutritional and medicinal value. Here we characterized the chromosome-level genome sequence of R. roxburghii, comprising seven pseudo-chromosomes with a total size of 531 Mb and a heterozygosity of 0.25%. We also annotated 45,226 coding gene loci after masking repeat elements. Orthologs for 90.1% of the Complete Single-Copy BUSCOs were found in the R. roxburghii annotation. By aligning with protein sequences from public platform, we annotated 85.89% genes from R. roxburghii. Comparative genomic analysis revealed that R. roxburghii diverged from Rosa chinensis approximately 5.58 to 13.17 million years ago, and no whole-genome duplication event occurred after the divergence from eudicots. To fully utilize this genomic resource, we constructed a genomic database RroFGD with various analysis tools. Otherwise, 69 enzyme genes involved in L-ascorbate biosynthesis were identified and a key enzyme in the biosynthesis of vitamin C, GDH (L-Gal-1-dehydrogenase), is used as an example to introduce the functions of the database. This genome and database will facilitate the future investigations into gene function and molecular breeding in R. roxburghii.

Salt cavern flow batteries (SCFBs) are an energy storage technology that utilize salt caverns to store electrolytes of flow batteries with a saturated NaCl solution as the supporting electrolyte. However, the geological characteristics of salt caverns differ significantly from above-ground storage tanks, leading to complex issues in storing electrolytes within salt caverns. Therefore, investigating and summarizing these issues is crucial for the advancement of SCFB technology. This paper’s innovation lies in its comprehensive review of the current state and development trends in SCFBs both domestically and internationally. First, the current development status of SCFB energy storage technology both domestically and internationally is summarized. Then, eight main issues are proposed from the perspectives of salt cavern geological characteristics (tightness, conductivity, ions, and temperature) and electrolyte properties (selection, permeability, corrosion, and concentration). Finally, a novel SCFB system is proposed to address the most critical issue, which is the low concentration and uneven distribution of active materials in the current SCFB system. The review in this paper not only comprehensively summarizes the development status of SCFBs both domestically and internationally, but also points out the direction for the future research focussing on SCFBs.

Abstract Contactless bubble manipulation with a high spatiotemporal resolution brings a qualitative leap forward in a variety of applications. Despite considerable advances, light-induced bubble maneuvering remains challenging in terms of robust transportation, splitting and detachment. Here, a photopyroelectric slippery surface (PESS) with a sandwich structure is constructed to achieve the versatile bubble manipulation. Due to the generated dielectric wetting and nonuniform electric field under the irradiation of near infrared (NIR) light, a bubble is subject to both the Laplace force and dielectrophoresis force, enabling a high-efficiency bubble steering. We demonstrate that the splitting, merging and detachment of underwater bubbles can be achieved with high flexibility and precision, high velocity and agile direction maneuverability. We further extend the capability of bubble control to microrobots for cargo transportation, micropart assembly and transmission of gear structures. We envision this robust bubble manipulation strategy on the PESS would provide a valuable platform for various bubble-involved processes, ranging from microfluidic devices to soft robotics.

Abstract Liquid unidirectional transport exhibits critical applications from water harvesting to microfluidics. Despite extensive progress, implementation of liquid unidirectional transport that is not subjected to the liquid surface tension and injecting velocity also remains a great challenge. Here, a tilted‐sector arrayed tube for excellent liquid unidirectional transport is proposed that applies to a vast width domain of liquid surface tension and injecting velocity. In addition, the transport direction is abnormally against the tilted direction of structure, in stark contrast to the traditional understanding that is along tilted direction. This excellent and unique liquid unidirectional transport is caused by synergistic effects of tilted sectors and tube structures, which induce a unique 3D liquid propagation mode as well as a large Laplace pressure asymmetry between the front and rear sides of the liquid. Moreover, the antigravity climbing, circuit isolating, and chemical reaction controlling can be achieved based on the excellent liquid unidirectional transport. It is envisioned that the design can be extensively applied in microfluidics, lab‐on‐a‐chip devices, and biochemistry microreactors.

Preventing the condensation of water is key for anti-icing applications. Here, a macro-ridged surface is found to prevent frost formation either side of each ridge, attributed to a change in water vapor distribution preventing ice bridge formation.

Abstract Superhydrophobic surfaces (SHSs) exist in many biological organisms endowed by spectacular surface topographies, which provide important insights to drive a paradigm shift in design of engineering surfaces. Based on this, extensive progresses have been developed on bionic superhydrophobic strategies. Among them, SHSs based on topography of copper oxides exhibit considerable application prospects because of the steerability and diversity of topography, as well as additional performances, such as antibiosis, anticorrosion and catalysis. We first present a brief overview of the discovery of natural SHSs as well as fundamental understanding of surface wetting performance. Then, the structural effects in superhydrophobic systems based on the topographies of biological organisms and copper oxides are described. Finally, we highlight the perspectives on the novel design strategies of copper oxide‐based SHSs that adapt to various practical applications.

Guided drop transport at high temperature is of great importance in various water and thermal management technologies. Here, authors report a steerable drop transport dictated by the drop boiling states on heated concentric microgroove arrays.

Abstract Background Jianpi Qinghua Fomula (JPQHF), a clinically proven prescription,has been applied to cure insulin resistance(IR) and type 2 diabetes (T2DM) for more than 20 years. Here, we will unravel the underlying molecular mechanisms relevant to the therapeutic actions of JPQHF. Methods High-fat(HF)diet-induced obesity(DIO)mouse were established in our research, along with insulin resistance. After the administration of JPQHF 5 or 6 weeks, the parameters of the glucose and lipid metabolism were measured. Flow cytometry and Luminex were utilized to assess the inflammation in small intestine,whilst Western blot was used to determine the relative expression levels of the MAPK pathway-related proteins. The glucose and lipid transporter of small intestine was assessed by immunofluorescence and ELISA, and the expression of insulin signaling pathway was detected by Western blot. Results The metabolic phenotypes of DIO mouse were ameliorated after 6-week oral administration of JPQHF; Meanwhile,JPQHF downregulated levels of IL-1β,IL-6, TNF-α and IFN-γ but upregulated the ratio of M2/M1 macrophages in the small intestine. The elevated expressions of p-P38 MAPK/P38 MAPK、p-JNK/JNK and p-ERK1/2/ERK1/2 were reversed by JPQHF. Moreover, JPQHF enhanced expression of PI3K,p-AKT/AKT, p-IRS1/ IRS1, p-IRS2/ IRS2 and apoB48 in small intestine, and facilitated the translocation of GLUT2 to the basal side of small intestine epithelial cells. Conclusion JPQHF alleviates insulin resistance in DIO mice, and this effect may be associated with its restraining of inflammation of small intestine via attenuating MAPK pathway, and then diminishes small intestinal glucose and lipid absorption.

Engineering marvels found throughout the exclusive structural features of biological surfaces have given rise to the progressive development of skin friction drag reduction. However, despite many previous works reporting forward drag reduction where the bio-inspired surface features are aligned with the flow direction, it is still challenging to achieve bidirectional drag reduction for non-morphable surface structures. Inspired by the flounder ctenoid scales characterized by tilted, millimeter-sized oval fins embedded with sub-millimeter spikes, we fabricate a bionic flounder two-tier structural surface (BFTSS) that can remarkably reduce the forward skin friction drag by ηdr = 19%. Even in the backwards direction, where the flow is completely against the tilting direction of surface structures, BFTSS still exhibits a considerable drag reduction of ηdr = 4.2%. Experiments and numerical simulations reveal that this unique bidirectional drag reduction is attributed to synergistic effects of the two-tier structures of BFTSS. The array of oval fins can distort the boundary layer flow and mitigate the viscous shear, whilst the microscale spikes act to promote the flow separation to relieve the pressure gradient in the viscous sublayer. Notably, the pressure gradient relief effect of microscale spikes remains invariant to the flow direction and is responsible for the backward drag reduction as well. The bidirectional drag reduction of BFTSS can be extensively applied in minimizing the energy consumption of ships and underwater vessels, as well as in pipeline transport.

AimsThis study aimed to compare the diagnostic accuracy of the metabolic syndrome with the Finnish Diabetes Risk Score (FINDRISC) to screen for type 2 diabetes mellitus (T2DM) in a Shanghai population.MethodsParticipants aged 25-64 years were recruited from a Shanghai population from July 2019 to March 2020. Each participant underwent a standard metabolic work-up, including clinical examination with anthropometry. Glucose status was tested using hemoglobin A1c (HbAlc), 2h-post-load glucose (2hPG), and fasting blood glucose (FBG). The FINDRISC questionnaire and the metabolic syndrome were examined. The performance of the FINDRISC was assessed using the area under the receiver operating characteristic curve (AUC-ROC).ResultsOf the 713 subjects, 9.1% were diagnosed with prediabetes, whereas 5.2% were diagnosed with T2DM. A total of 172 subjects had the metabolic syndrome. A higher FINDRISC score was positively associated with the prevalence of T2DM and the metabolic syndrome. Multivariable linear regression analysis demonstrated that the FINDRISC had a linear regression relationship with 2hPG levels (b’= 036, p < 0.0001). The AUC-ROC of the FINDRISC to identify subjects with T2DM among the total population was 0.708 (95% CI 0.639–0.776), the sensitivity was 44.6%, and the specificity was 90.1%, with 11 as the cut-off point. After adding FBG or 2hPG to the FINDRISC, the AUC-ROC among the total population significantly increased to 0.785 (95% CI 0.671–0.899) and 0.731 (95% CI 0.619–0.843), respectively, while the AUC-ROC among the female group increased to 0.858 (95% CI 0.753–0.964) and 0.823 (95% CI 0.730–0.916), respectively (p < 0.001). The AUC-ROC of the metabolic syndrome to identify subjects with T2DM among the total and female population was 0.805 (95% CI 0.767–0.844) and 0.830 (95% CI 0.788–0.872), respectively, with seven as the cut-off point.ConclusionsThe metabolic syndrome performed better than the FINDRISC model. The metabolic syndrome and the FINDRISC with FBG or 2hPG in a two-step screening model are both efficacious clinical practices for predicting T2DM in a Shanghai population.

In order to discover more promising antifungal and antibacterial agents, a series of new derivatives were designed and synthesized by structure modification based on the naturally occurring antimicrobial compound lophanic acid. The structures of all the target compounds were well characterized by spectroscopic data. The stereochemistry of these compounds was further determined through the X-ray diffraction analysis of 6a. The synthetic compounds were evaluated for their antimicrobial activities against filamentous fungi (T. rubrum, T. mentagrophytes), yeasts (C. neoformans, C. albicans) and Gram-positive and Gram-negative bacteria (MRSA, S. mutans, S. sobrinus, and E. coli). Among them, 3d and 3i are found as the most promising leads that showed potent inhibitory effects against all the tested fungal and bacterial strains except for E. coli. The presence of the C-20 carboxylic ester groups and the free hydroxy group at C-13 was found to be essential for the antifungal and antibacterial activities of the lophanic acid derivatives.

Hot-water repellency is of great challenge on traditional superhydrophobic surfaces due to the condensation of tiny droplets within the cavities of surface textures, which builds liquid bridges to connect the substrate and hot water and thus destroys the surface water-repellence performance. For the unique structural features and scales, current approaches to fabricate surfaces with hot-water repellency are always complicated and modified by fluorocarbon. Here, we propose a facile and fluorine-free one-step vapor-deposition method for fabricating excellent hot-water-repellent surfaces, which at room temperature even repel water droplets of temperature up to 90 °C as well as other normal-temperature droplets with surface tension higher than 48.4 mN/m. We show that whether the unique hot-water repellency is achieved depends on a trade-off between the solid–liquid contact time and hot-vapor condensation time, which determines the probability of formation of liquid bridges between the substrate and hot-water. Moreover, the designed surfaces exhibit excellent self-cleaning performance in some specific situations, such as oil medium, hot water and condensation environments. We envision that this facile and fluorine-free strategy for fabricating excellent hot-water-repellent surfaces could be valuable in popularizing their practical applications.

Hyperlipidemia is a risk factor for cardiovascular disease and has become a significant public health problem. In this study, PacBio single-molecule real-time sequencing technology combined with a metabolomics study of koumiss revealed a series of changes in serum lipids, gut microbiota and viscera indices in hyperlipidemia patients 0, 30 and 60 days following daily koumiss treatment. High density lipoprotein cholesterol concentrations significantly increased, while levels of immunoglobulin G and albumin significantly decreased after koumiss treatment. Moreover, the abundance of some Bacteroides, Dorea and Catenibacterium species increased, whereas the abundance of Clostridium and Citrobacter species decreased. Our results indicate that koumiss consumption alleviates the symptoms of hyperlipidemia. This is associated with both the bacterial composition of the koumiss, particularly Lactobacillus and Streptococcus species, and the metabolites present in koumiss, such as s-adenosyl-l-methionine, carnosine, lysophosphatidylinositol and dipeptides. This study provides insight into the mechanisms underpinning the effects of koumiss on hypolipidemic symptoms.

The dynamic interaction of droplets with slippery surfaces is essential to various industrial applications, such as anti-icing, water-repellency or water-harvesting, anti-bacterial, and phase change heat transfer. With recent progress in materials, manufacturing as well as learning from nature, the physics of droplet dynamics has been greatly enriched owing to the emergence of peculiar wetting states manifested on bio-inspired textured surfaces. This review is devoted to the discussion of the recent progress made in the authors’ understanding of the dynamic interaction of small droplets with bio-inspired surfaces. Particular attention is given to droplet impact on slippery surfaces, such as superhydrophobic surfaces characterised with air–solid–liquid triple-phase interface and slippery lubricant infused porous surfaces characterised with the liquid/liquid two-phase interface. Droplet spreading, retraction, contact time, elastodynamics as well as oblique impact are systematically reviewed. Finally, the authors offer their perspectives on this important and highly multidisciplinary research area.

The first synthesis of the hinckdentine A framework 6 using a 19-step reaction sequence from readily available starting materials is presented. 8-desbromohinckdentine A is synthesized from a 2-aryl indole by first preparing the quaternary center of the natural product, the key structural feature.

The article discusses a new methodology, where in the N,N-di-tert-butoxycarbonylpyridin-4-amines are rearranged to lead to the formation of polyfunctional pyridines. These functionalized pyridines are shown to be extremely useful for the synthesis of different nitrogen-containing heterocyclic compounds.

The antifouling property of exogenous materials is vital for their in vivo applications. In this work, dissipative particle dynamics simulations are performed to study the self-assembled morphologies of two copolymer systems containing poly(ethylene glycol) (PEG) and poly(carboxybetaine) (PCB) in aqueous solutions. Effects of polymer composition and polymer concentration on the self-assembled structures of the two copolymers (PLA-PEG and PLA-PCB) are investigated, respectively [PLA represents poly(lactic acid)]. Results show that whatever the copolymer composition is, PLA-PEG systems will self-assemble into core-shell structures, whereas onion-like and vesicle structures are also found for the PLA-PCB systems. Different morphologies are obtained at different polymer concentrations in both copolymer systems. Simulation results demonstrate that PCB is more stable than PEG in maintaining self-assembled spherical structures of copolymer systems because PLA-PEG forms dumbbell-like structures whereas PLA-PCB is spherical under the same polymer concentration. Although both copolymer systems can self-assemble into core-shell nanoparticles when the block ratio of PLA:PEG or PLA:PCB is 80:20, the core-shell structures of the nanoparticles are quite different. The shell layers formed by PEG in PLA-PEG nanoparticles are inhomogeneous in size because of the amphiphilicity of PEG, whereas the shell layers in PLA-PCB nanoparticles are homogenous because of the strong hydrophilicity of the zwitterionic PCB polymer block. [ABSTRACT FROM AUTHOR]

Biodegradable stents made of poly-L-lactic acid (PLLA) have a promising prospect thanks to high biocompatibility and a favorable biodegradation period. However, due to the low stiffness of PLLA, polymeric stents have a lower radial stiffness and larger foreshortening. Furthermore, a stent is a tiny meshed tube, hence, it is difficult to make a polymeric stent. In the present study, a finite element analysis-based optimization method combined with Kriging surrogate modeling is firstly proposed to optimize the stent structure and stent microinjection molding process, so as to improve the stent mechanical properties and microinjection molding quality, respectively. The Kriging surrogate models are constructed to formulate the approximate mathematical relationships between the design variables and design objectives. Expected improvement is employed to balance local and global search to find the global optimal design. As an example, the polymeric ART18Z stent was investigated. The mechanical properties of stent expansion in a stenotic artery and the molding quality were improved after optimization. Numerical results demonstrate the proposed optimization method can be used for the computationally measurable optimality of stent structure design and stent microinjection molding process. [ABSTRACT FROM AUTHOR]

Drop hitting on superhydrophobic surfaces usually undergoes spreading and retraction stages before its complete rebound and there exists a minimum amount of time for the spreading and retraction processes. Impressively, it was recently shown that the so-called contact time can be significantly reduced by engineering surfaces with millimeter-scale tapered post arrays that allow the impinging drop to leave the surfaces in a pancake shape at the end of lateral spreading (pancake bouncing). Despite exciting progress, it remains elusive to rationally control the contact time and quantitatively predict the critical Weber number for the occurrence of pancake bouncing. Here, we experimentally demonstrated that the drop bouncing is intricately modulated by the surface morphology. Under the same centre-to-centre post spacing, surfaces with a larger apex angle could give rise to more robust pancake bouncing, which is characterized by significant contact time reduction, smaller critical Weber number, and wider Weber number range. We also developed simple harmonic spring models and theoretically revealed the dependence of timescales associated with the impinging drop and the critical Weber number for pancake bouncing on the surface morphology. The insights learned from this work will allow us to rationally design various surfaces for many practical applications. [ABSTRACT FROM AUTHOR]

Electrowetting on dielectric (EWOD) has emerged as a powerful tool to electrically manipulate tiny individual droplets in a controlled manner. Despite tremendous progress over the past two decades, current EWOD operating in ambient conditions has limited functionalities posing challenges for its applications, including electronic display, energy generation, and micro fluidic systems. Here, we demonstrate a new paradigm of electrowetting on liquid-infused film (EWOLF) that allows for complete reversibility and tunable transient response simultaneously. We determine that these functionalities in EWOLF are attributed to its novel configuration, which allows for the formation of viscous liquid-liquid interfaces as well as additional wetting ridges, thereby suppressing the contact line pinning and severe droplet oscillation encountered in the conventional EWOD. Finally, by harnessing these functionalities demonstrated in EWOLF, we also explore its application as liquid lens for fast optical focusing. [ABSTRACT FROM AUTHOR]

Pentosidine, a fluorescent advanced glycation endproduct that serves as a biomarker of diabetic complications, kidney dysfunction, oxidative stress, and aging and age-related diseases, was synthesized from 2,3-diaminopyridine and benzyloxycarbonyl (Cbz) protected chiral amino acids N-Cbz-lysine and N-Cbz-ornithine. Regioselective alkylation of 2-(methylthio)imidazo[4,5- b]pyridine, chlorination of methylthio group, and amination of 2-chloro-imidazo[4,5- b]pyridine are the key steps. Hydantoin protection of amino acids was used and the deprotection under acidic condition was achieved in the presence of glycine. J. Heterocyclic Chem., (2011). [ABSTRACT FROM AUTHOR]

Pentosidine framework 4-butyl-2-propyl-4H-aminoimidazo[4,5-b]pyridine (2) was synthesized through a five steps reaction sequence. The regiochemistry of 2 was confirmed by an unambiguous synthesis, and the UV absorption and fluorescent properties of 2 were examined. J. Heterocyclic Chem., (2010). [ABSTRACT FROM AUTHOR]

Discusses the independent synthesis, solution behavior, and the mechanism of formation of a primary amine-derived fluorophore representing cross-linking of proteins by (E)-4-hydroxy-2-nonenal. Fluorophore formation in reactions of primary amines with (E)-4-hydroxy-2-nonenal (HNE) or (E)-4-hydroxy-2-hexenal.

The article presents a surface chemistry research study on the development of a droplet ultrasonic tweezer (DUT) for versatile droplet manipulation without the need for surface or droplet pretreatment. Topics include DUT utilizing a trap ultrasonic field generated by a phased array, allowing precise and programmable control of droplets; and demonstrating the ability of the DUT to manipulate droplets through confined slits offering potential applications in droplet ejection and surface cleaning.

While the drop impact dynamics on stationary surfaces has been widely studied, the way a drop impacts a moving solid is by far less known. Here, we report the physical mechanisms of water drops impacting on superhydrophobic surfaces with horizontal motions. We find that a viscous force is created due to the entrainment of a thin air layer between the liquid and solid interfaces, which competes with the capillary and inertia forces, leading to an asymmetric elongation of the drop and an unexpected contact time reduction. Our experimental and theoretical results uncover consolidated scaling relations: the maximum spreading diameter is controlled by both the Weber and capillary numbers Dmax/D0∼We1/4Ca1/6, while the dimensionless contact time depends on the capillary number τ/τ0∼Ca-1/6. These findings strengthen our fundamental understandings of interactions between drops and moving solids and open up new opportunities for controlling the preferred water repellency through largely unexplored active approaches. [ABSTRACT FROM AUTHOR]

Objective: To investigate the potential mechanisms underlying the dark red tongue color formation induced by hyperglycemia., Methods: A high-fat diet and intraperitoneal injection of streptozotocin were used to establish a diabetes model. The color and blood flow of tongues were analyzed by the Tongue Diagnosis Analysis System and laser Doppler flowmetry, respectively. Inflammatory factors and adhesion factors were measured in the circulation and tongue tissue by an enzyme-linked immunosorbent assay. Western blotting was employed to evaluate nuclear factor-kappa B (NF-κB) p50 and inhibitor of kappa B kinase protein expression levels in the tongue. Then, the NF-κB inhibitor, pyrrolidine dithiocarbamic acid ammonium salt was utilized to repress NF-κB pathway activation to validate that the NF-κB pathway plays a key role in blood flow and dark red tongue color formation., Results: The diabetic rats displayed a dark red tongue color that was accompanied by NF-κB pathway activation and decreased blood flow in the tongue. These effects could be reversed by the NF-κB inhibitor., Conclusions: Our investigation demonstrated that hyperglycemia led to dark red tongue color formation by decreasing blood flow in the tongue, which was partly due to NF-κB pathway activation.