Nanopore Blockade Sensors for Quantitative Analysis Using an Optical Nanopore Assay.

Nanopore sensing is a popular biosensing strategy that is being explored for the quantitative analysis of biomarkers. With low concentrations of analytes, nanopore sensors face challenges related to slow response times and selectivity. Here, we demonstrate an approach to rapidly detect species at ultralow concentrations using an optical nanopore blockade sensor for quantitative detection of the protein vascular endothelial growth factor (VEGF). This sensor relies on monitoring fluorescent polystyrene nanoparticles blocking nanopores in a nanopore array of 676 nanopores. The fluorescent signal is read out using a wide-field fluorescence microscope. Nonspecific blockade events are then distinguished from specific blockade events based on the ability to pull the particles out of the pore using an applied electric field. This allows the detection of VEGF at sub-picomolar concentration in less than 15 min.

PEI-Mediated Assembly of Fe3O4 onto SiO2-Encapsulated CsPbBr3 for Highly Sensitive Fluorescent Lateral Flow Immunoassay.

The conventional lateral flow immunoassay (LFIA) method using colloidal gold nanoparticles (Au NPs) as labeling agents faces two inherent limitations, including restricted sensitivity and poor quantitative capability, which impede early viral infection detection. Herein, we designed and synthesized CsPbBr3 perovskite quantum dot-based composite nanoparticles, CsPbBr3@SiO2@Fe3O4 (CSF), which integrated fluorescence detection and magnetic enrichment properties into LFIA technology and achieved rapid, sensitive, and convenient quantitative detection of the SARS-CoV-2 virus N protein. In this study, CsPbBr3 served as a high-quantum-yield fluorescent signaling probe, while SiO2 significantly enhanced the stability and biomodifiability of CsPbBr3. Importantly, the SiO2 shell shows relatively low absorption or scattering toward fluorescence, maintaining a quantum yield of up to 74.4% in CsPbBr3@SiO2. Assembly of Fe3O4 nanoparticles mediated by PEI further enhanced the method's sensitivity and reduced matrix interference through magnetic enrichment. Consequently, the method achieved a fluorescent detection range of 1 × 102 to 5 × 106 pg·mL-1 after magnetic enrichment, with a limit of detection (LOD) of 58.8 pg·mL-1, representing a 13.3-fold improvement compared to nonenriched samples (7.58 × 102 pg·mL-1) and a 2-orders-of-magnitude improvement over commercial colloidal gold kits. Furthermore, the method exhibited 80% positive and 100% negative detection rates in clinical samples. This approach holds promise for on-site diagnosis, home-based quantitative tests, and disease procession evaluation.

SERS Platform for Integrated Enrichment, Isolation, and Identification of Multiple Respiratory Viruses in a Single Assay Using 3D Stereoscopic SERS Tags and Flocked Swabs.

Influenza (flu) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exhibit similar clinical symptoms, complicating the diagnosis and clinical management of these critical respiratory infections. Thus, there is an urgent need for rapid on-site detection technologies that can simultaneously detect SARS-CoV-2 and influenza A viruses. Here, we have developed the first platform that combines in situ sampling with immune swabs and multichannel surface-enhanced Raman spectroscopy (SERS) for simultaneous screening of these two respiratory viruses in a single assay. A seed-mediated growth method was used to assemble a number of silver spheres on the surface of Fe3O4@SiO2 spheres, which not only creates extensive Raman hotspots but also provides numerous sites for Raman signaling molecules, enhancing the sensing sensitivity. Integrating two specific Raman signaling molecules into the nanospheres allows for the parallel detection of both viruses, improving the efficiency of SERS signal read-out. Rapid quantitative screening of both SARS-CoV-2 and H1N1 is achievable within 15 min, with detection limits of 7.76, and 8.13 pg·mL-1 for their respective target proteins. The platform demonstrated excellent performance in testing and analyzing 98 clinical samples (SARS-CoV-2:50; influenza A:48), achieving sensitivities of 88.00, and 95.83% for SARS-CoV-2 and influenza A, respectively. Pearson's correlation analysis revealed a significant correlation with the clinical CT values (P < 0.0001), underscoring the great potential of this platform for the early, rapid, and simultaneous diagnostic discrimination of multiple pathogens.

Plasma-Engraved Lattice-Matched NiO/NiFe2O4 Heterostructure with Ample Oxygen Vacancies for Efficient Water Electrolysis and Zn-Air Batteries.

Heterogeneous interface and defect engineering offer effective pathways to accelerate oxygen evolution reaction (OER) charge transfer kinetics and motivate optimal intrinsic catalytic activity. Herein, we report the lattice-matched NiO/NiFe2O4 heterostructure with ample oxygen vacancies (Vo-NiO/NiFe2O4) induced by a feasible hydrothermal followed by calcination and plasma-engraving assistant technique, which shows the unique porous microflower arrangement of intertwined nanosheets. Benefitting from the synergetic effects between lattice-matched heterointerface and oxygen vacancies induce the strong electronic coupling, optimized OH-/O2 diffusion pathway and ample active sites, thus-prepared Vo-NiO/NiFe2O4 presents a favorable OER performance with a low overpotential (261 mV @ 10 mA cm-2) and small Tafel slope (39.4 mV dec-1), even surpassing commercial RuO2 catalyst. Additionally, the two-electrode configuration water electrolyzer and rechargeable zinc-air battery assembled by Vo-NiO/NiFe2O4 catalyst show the potential practical application directions. This work provides an innovative avenue for strengthening OER performance toward water electrolysis and Zn-air batteries via the interface and vacancy engineering strategy.

Exploring the XIST axis as oxidative stress-related signatures in systemic lupus erythematosus.

OBJECTIVES: In the pathogenesis of systemic lupus erythematosus (SLE), oxidative stress (OS) plays an complex role; nevertheless, few investigations have indicated a ceRNA-based mechanism involved. The aim of this study was to explore the ceRNA regulation mechanism of oxidative stress in SLE and provide new therapeutic targets for SLE. METHODS: Three datasets from the Gene Expression Omnibus (GEO) database were used to obtain differentially expressed lncRNAs, miRNAs, and mRNAs (DElncRNAs, DEmiRNAs, and DEmRNAs). Functional analysis was explored and a triple ceRNA network was built. Least absolute shrinkage and selection operator regression was used to find optimal signatures. The sensitivity and specificity of the signatures were examined and validated using receiver operating characteristic (ROC) analysis. The CIBERSORT algorithm was used to investigate immune infiltration features. Moreover, the hub mRNAs were validated by quantitative real-time PCR. RESULTS: 42 DEmRNAs were identified. Enrichment analysis showed that the DEmRNAs were primarily concentrated in neutrophil-associated biological processes. The ROC curve found FOS and MME provided potential biomarkers for identifying SLE patients. And the XIST/FOS and XIST/MME axes were identified the possible OS-related regulatory pathway in SLE. Immune infiltration showed that resting memory CD4 T cells presented a lower level. CONCLUSIONS: This study constructed the ceRNA-based XIST/FOS and XIST/MME axes as prospective OS-related signatures for SLE. Our findings provide new insights into the pathogenesis of SLE and shed a novel light on therapeutic strategies.

bcIRF5 activates bcTBK1 phosphorylation to enhance PANoptosis during GCRV infection.

TBK1 is an important IFN antiviral signalling factor, and in previous work black carp TBK1 (bcTBK1) and black carp IRF5 (bcIRF5) together promoted cell death in GCRV-infected cells. In this research, bcTBK1 and bcIRF5 were investigated both in vivo and in vitro to delineate their individual and combined functions. This study demonstrated that both bcTBK1 and bcIRF5 expressions were modulated in response to GCRV infection across the intestine, gill, kidney and spleen. In bcgill cells, overexpression of bcTBK1 and bcIRF5 initially suppressed the expression of cell death-related genes, including RIPK1, caspase1, caspase3 and bax, but this suppression was negated upon GCRV infection. In vivo, mRNA expression levels of RIPK1 and related genes varied by tissue following bcTBK1 or bcIRF5 overexpression and GCRV infection. Notably, intracellular co-overexpression of bcTBK1 and bcIRF5 led to significant upregulation of caspase3, caspase1, bax, and IL1ß, along with enhanced caspase3 activity post-GCRV infection. This co-expression correlated with higher survival rates in black carp during GCRV infection and increased caspase3 mRNA in the spleen and gills. Hematoxylin-eosin (HE) staining indicated disorganized spleen tissue and edematous, hyperplastic gill changes in co-transfected groups after infection. TUNEL staining of tissue sections showed that DNA breakage was significantly stronger in the co-transfected group than in the other groups during GCRV infection. Further phosphorylation experiments showed that bcIRF5 promoted phosphorylation modification of bcTBK1. Thus, these data suggest that bcIRF5 activates bcTBK1 by enhancing its phosphorylation and promotes PANoptosis in GCRV-infected cells.

Identification, characterization and optimization of culture medium conditions for organic acid-producing lactic acid bacteria strains from Chinese fermented vegetables.

Lactic acid bacteria (LAB) are widely exploited in fermented foods and are gaining attention for novel uses due to their safety as biopreservatives. In this study, several organic acid-producing LAB strains were isolated from fermented vegetables for their potential application in fermentation. We identified nine novel strains belonging to four genera and five species, Lactobacillus plantarum PC1-1, YCI-2 (8), YC1-1-4B, YC1-4 (4), and YC2-9, Lactobacillus buchneri PC-C1, Pediococcus pentosaceus PC2-1 (F2), Weissella hellenica PC1A, and Enterococcus sp. YC2-6. Based on the results of organic acids, acidification, growth rate, antibiotic activity and antimicrobial inhibition, PC1-1, YC1-1-4B, PC2-1(F2), and PC-C1 showed exceptional biopreservative potential. Additionally, PC-C1, YC1-1-4B, and PC2-1(F2) recorded higher (p < 0.05) growth by utilizing lower concentrations of glucose (20 g/L) and soy peptone (10 g/L) as carbon and nitrogen sources in optimized culture conditions (pH 6, temperature 32 °C, and agitation speed 180 rpm) at 24hr and acidification until 72hr in batch fermentation, which suggests their application as starter cultures in industrial fermentation.

Evolution of fermented grain yeast communities in strong-flavored baijiu and functional validation of yeasts that produce superior-flavored substances.

BACKGROUND: Baijiu is a well-known alcoholic beverage in China and the quality is determined by various microorganisms during the fermentation process. Yeast is one of the most important microorganisms in the fermentation of baijiu. It has a strong esterification capacity and also affects the aroma. RESULTS: High-throughput sequencing results showed that the fermented grains (jiupei) during baijiu production were mainly composed of eight highly abundant yeast species. The species and abundance of yeasts changed significantly with the fermentation process. The flavor of 30 yeast strains in the jiupei was determined by a sniffing test and gas chromatography-mass spectrometry (GC-MS). The strain with the highest flavor substance content (2.34 mg L-1), named YX3205, was identified as Clavispora lusitaniae. Tolerance results showed that C. lusitaniae YX3205 can tolerate up to 15% (v v-1) ethanol. In a solid-state simulated fermentation experiment, the content of 24 flavor substances was significantly increased in the fortified group, and the total ester content reached 4240.73 µg kg-1, which was 2.8 times higher than that of the control group. CONCLUSION: The present study demonstrated the potential of C. lusitaniae YX3205 to enhance the flavor of baijiu, thereby serving as a valuable strain for the improvement of the flavor quality of baijiu. © 2024 Society of Chemical Industry.

Integrated Monomer Synthesis and Framework Assembly: Achieving Isoreticular Modulation of Hydrogen-Bonded Organic Frameworks.

Systematic construction of isoreticular hydrogen-bonded organic frameworks (HOFs) promises tailored material properties crucial for diverse applications, yet is challenging due to the weak, flexible, and non-directional nature of hydrogen bonds. Herein, we develop an "integrated monomer synthesis-framework assembly" (ISA) methodology for constructing a series of isoreticular HOFs. Unlike traditional methods where monomers are first synthesized and then assembled into HOFs, the ISA system employs dicyandiamide rigid hydrogen-bonded hexameric clusters as connecting nodes to covalently react with planarized C3-symmetric cyano-precursors (C3-CPs) to generate diaminotriazine (DAT) monomers, while simultaneously inducing the directional assembly into isoreticular (6,3)-net hcb topological DAT-C6-HOFs. The pore sizes and microenvironments of the resulting DAT-C6-HOFs can be precisely tuned by varying the structural modulation (length and steric hindrance) of the π-bridge on C3-CPs, enabling highly selective sensing towards perfluorooctanoic acid over other homologous molecules, that are difficult to be separated and detected by chromatography. Overall, the ISA methodology facilitates the scalable creation of families of isostructural HOFs and provides a customized structural platform for investigating factors beyond topology that impact the capturing, releasing, and responding to guest molecules.

Bacterial biosynthesis of flavonoids: Overview, current biotechnology applications, challenges, and prospects.

Flavonoids are secondary metabolites present in plant organs and tissues. These natural metabolites are the most prevalent and display a wide range of beneficial physiological effects, making them usually intriguing in several scientific fields. Due to their safety for use and protective attributes, including antioxidant, anti-inflammatory, anticancer, and antimicrobial functions, flavonoids are broadly utilized in foods, pharmaceuticals, and nutraceuticals. However, conventional methods for producing flavonoids, such as plant extraction and chemical synthesis, entailed dangerous substances, and laborious procedures, with low product yield. Recent studies have documented the ability of microorganisms, such as fungi and bacteria, to synthesize adequate amounts of flavonoids. Bacterial biosynthesis of flavonoids from plant biomass is a viable and environmentally friendly technique for producing flavonoids on a larger scale and has recently received much attention. Still, only a few bacteria species, particularly Escherichia coli, have been extensively studied. The most recent developments in bacterial biosynthesis of flavonoids are reviewed and discussed in this article, including their various applications as natural food biocontrol agents. In addition, the challenges currently faced in bacterial flavonoid biosynthesis and possible solutions, including the application of modern biotechnology approaches for developing bacterial strains that could successfully produce flavonoids on an industrial scale, were elucidated.

Three-dimensional High-Resolution Dark-Blood Late Gadolinium Enhancement Imaging for Improved Atrial Scar Evaluation.

Background Radiofrequency ablation (RFA) is a widely used treatment for atrial fibrillation, reducing the risk of cardiac arrhythmia. Detailed visualization and quantification of atrial scarring has the potential to improve preprocedural decision-making and postprocedural prognosis. Conventional bright-blood late gadolinium enhancement (LGE) MRI can help detect atrial scars; however, its suboptimal myocardium to blood contrast inhibits accurate scar estimation. Purpose To develop and test a free-breathing LGE cardiac MRI approach that simultaneously provides high-spatial-resolution dark-blood and bright-blood images for improved atrial scar detection and quantification. Materials and Methods A free-breathing, independent navigator-gated, dark-blood phase-sensitive inversion recovery (PSIR) sequence with whole-heart coverage was developed. Two coregistered high-spatial-resolution (1.25 × 1.25 × 3 mm3) three-dimensional (3D) volumes were acquired in an interleaved manner. The first volume combined inversion recovery and T2 preparation to achieve dark-blood imaging. The second volume functioned as the reference for phase-sensitive reconstruction with built-in T2 preparation for improved bright-blood contrast. The proposed sequence was tested in prospectively enrolled participants who had undergone RFA for atrial fibrillation (mean time since RFA, 89 days ± 26 [SD]) from October 2019 to October 2021. Image contrast was compared with conventional 3D bright-blood PSIR images using the relative signal intensity difference. Furthermore, native scar area quantification obtained from both imaging approaches was compared with measurements obtained with electroanatomic mapping (EAM) as the reference standard. Results A total of 20 participants (mean age, 62 years ± 9; 16 male) who underwent RFA for atrial fibrillation were included. The proposed PSIR sequence successfully acquired 3D high-spatial-resolution volumes in all participants, with a mean scan time of 8.3 minutes ± 2.4. The developed PSIR sequence improved scar to blood contrast compared with conventional PSIR sequence (mean contrast, 0.60 arbitrary units [au] ± 0.18 vs 0.20 au ± 0.19, respectively; P < .01) and correlated with EAM regarding scar area quantification (r = 0.66 [P < .01] vs r = 0.13 [P = .63]). Conclusion In participants who had undergone RFA for atrial fibrillation, an independent navigator-gated dark-blood PSIR sequence produced high-spatial-resolution dark-blood and bright-blood images with improved image contrast and native scar quantification compared with conventional bright-blood images. © RSNA, 2023 Supplemental material is available for this article.

bta-miR-183 targets EZRIN to regulate microvilli formation and improve early development of bovine embryos.

In brief: Almost total lack of sperm-borne RNAs is regarded as one of the key factors that leads to the abnormal development of somatic cell nuclear transfer embryo. This paper reveals a need for us to further explore the roles of the paternal regulatory factors on embryonic development in early embryos. Abstract: Mature sperm contain both coding and non-coding RNAs, which can be delivered into an oocyte with the sperm at fertilization. Accumulating evidences show that these sperm-borne RNAs play crucial roles in epigenetic reprogramming, cytoskeleton remodeling, embryonic development, and offspring phenotype. Almost total lack of sperm-borne RNAs is regarded as one of the key factors that leads to the abnormal development of somatic cell nuclear transfer (SCNT) embryo. bta-miR-183 was found to be highly expressed in bovine sperm and can be delivered into oocytes during fertilization in our previous study, and in this study, EZR was confirmed as a target gene of bta-miR-183 in early embryos by bioinformatics, luciferase, and gain-of-function and loss-of-function experiments. Scanning electron microscopy showed that the density of microvilli on the surface of SCNT embryos was significantly higher than that onin vitro fertilized embryos and was significantly reduced by injection of bta-miR-183 mimic. EZR-siRNA injected into SCNT embryos had a similar effect. This indicated that the lack of bta-miR-183 might lead to abnormal changes in microvilli by downregulating ezrin protein. In addition, gain-of-function studies showed that bta-miR-183 significantly improved developmental competence of SCNT embryo in terms of cleavage (76.63% vs 64.32%, P < 0.05), blastocyst formation (43.75% vs 28.26%, P < 0.05), apoptotic index (5.21% vs 12.64%, P < 0.05), and the trophoblast ratio (32.65% vs 25.58%, P < 0.05) in day 7 blastocysts. Thus, the present study indicated that bta-miR-183 might play crucial roles in the formation of microvilli and embryo development by regulating expression of EZR mRNA.

Comprehensive analysis identifies CLEC1B as a potential prognostic biomarker in hepatocellular carcinoma.

BACKGROUND: C-type lectin domain family 1 member B (CLEC1B, encoding the CLEC-2 protein), a member of the C-type lectin superfamily, is a type II transmembrane receptor involved in platelet activation, angiogenesis, and immune and inflammatory responses. However, data regarding its function and clinical prognostic value in hepatocellular carcinoma (HCC) remain scarce. METHODS: The expression of CLEC1B was explored using The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. RT-qPCR, western blot, and immunohistochemistry assays were employed to validate the downregulation of CLEC1B. Univariate Cox regression and survival analyses were used to evaluate the prognostic value of CLEC1B. Gene Set Enrichment Analysis (GSEA) was conducted to investigate the potential association between cancer hallmarks and CLEC1B expression. The TISIDB database was applied to search for the correlation between immune cell infiltration levels and CLEC1B expression. The association between CLEC1B and immunomodulators was conducted by Spearman correlation analysis based on the Sangerbox platform. Annexin V-FITC/PI apoptosis kit was used for the detection of cell apoptosis. RESULTS: The expression of CLEC1B was low in various tumors and exhibited a promising clinical prognostic value for HCC patients. The expression level of CLEC1B was tightly associated with the infiltration of various immune cells in the HCC tumor microenvironment (TME) and positively correlated with a bulk of immunomodulators. In addition, CLEC1B and its related genes or interacting proteins are implicated in multiple immune-related processes and signaling pathways. Moreover, overexpression of CLEC1B significantly influenced the treatment effects of sorafenib on HCC cells. CONCLUSIONS: Our results reveal that CLEC1B could serve as a potential prognostic biomarker and may be a novel immunoregulator for HCC. However, its function in immune regulation should be further explored.

Chromosome-level genome assembly of a high-altitude-adapted frog (Rana kukunoris) from the Tibetan plateau provides insight into amphibian genome evolution and adaptation.

BACKGROUND: The high-altitude-adapted frog Rana kukunoris, occurring on the Tibetan plateau, is an excellent model to study life history evolution and adaptation to harsh high-altitude environments. However, genomic resources for this species are still underdeveloped constraining attempts to investigate the underpinnings of adaptation. RESULTS: The R. kukunoris genome was assembled to a size of 4.83 Gb and the contig N50 was 1.80 Mb. The 6555 contigs were clustered and ordered into 12 pseudo-chromosomes covering ~ 93.07% of the assembled genome. In total, 32,304 genes were functionally annotated. Synteny analysis between the genomes of R. kukunoris and a low latitude species Rana temporaria showed a high degree of chromosome level synteny with one fusion event between chr11 and chr13 forming pseudo-chromosome 11 in R. kukunoris. Characterization of features of the R. kukunoris genome identified that 61.5% consisted of transposable elements and expansions of gene families related to cell nucleus structure and taste sense were identified. Ninety-five single-copy orthologous genes were identified as being under positive selection and had functions associated with the positive regulation of proteins in the catabolic process and negative regulation of developmental growth. These gene family expansions and positively selected genes indicate regions for further interrogation to understand adaptation to high altitude. CONCLUSIONS: Here, we reported a high-quality chromosome-level genome assembly of a high-altitude amphibian species using a combination of Illumina, PacBio and Hi-C sequencing technologies. This genome assembly provides a valuable resource for subsequent research on R. kukunoris genomics and amphibian genome evolution in general.

Molecular dissection on inhibition of Ras-induced cellular senescence by small t antigen of SV40.

Simian virus 40 (SV40) is a potentially oncogenic virus of monkey origin. Transmission, prevalence, and pathogenicity rates of SV40 are unclear, but infection can occur in humans, for example individuals with high contact with rhesus macaques and individuals that received contaminated early batches of polio vaccines in 1950-1963. In addition, several human polyomaviruses, proven carcinogenic, are also highly common in global populations. Cellular senescence is a major mechanism of cancer prevention in vivo. Hyperactivation of Ras usually induces cellular senescence rather than cell transformation. Previous studies suggest small t antigen (ST) of SV40 may interfere with cellular senescence induced by Ras. In the current study, ST was demonstrated to inhibit Ras-induced cellular senescence (RIS) and accumulation of DNA damage in Ras-activated cells. In addition, ST suppressed the signal transmission from BRaf to MEK and thus blocked the downstream transmission of the activated Ras signal. B56γ knockdown mimicked the inhibitory effects of ST overexpression on RIS. Furthermore, KSR1 knockdown inhibited Ras activation and the subsequent cellular senescence. Further mechanism studies indicated that the phosphorylation level of KSR1 rather than the levels of the total protein regulates the activation of Ras signaling pathway. In sum, ST inhibits the continuous hyperactivation of Ras signals by interfering with the normal functions of PP2A-B56γ of dephosphorylating KSR1, thus inhibiting the occurrence of cellular senescence. Although the roles of SV40 in human carcinogenesis are controversial so far, our study has shown that ST of polyomaviruses has tumorigenic potential by inhibiting oncogene-induced senescence (OIS) as a proof of concept.

The application of single molecule nanopore sensing for quantitative analysis.

Nanopore-based sensors typically work by monitoring transient pulses in conductance via current-time traces as molecules translocate through the nanopore. The unique property of being able to monitor single molecules gives nanopore sensors the potential as quantitative sensors based on the counting of single molecules. This review provides an overview of the concepts and fabrication of nanopore sensors as well as nanopore sensing with a view toward using nanopore sensors for quantitative analysis. We first introduce the classification of nanopores and highlight their applications in molecular identification with some pioneering studies. The review then shifts focus to recent strategies to extend nanopore sensors to devices that can rapidly and accurately quantify the amount of an analyte of interest. Finally, future prospects are provided and briefly discussed. The aim of this review is to aid in understanding recent advances, challenges, and prospects for nanopore sensors for quantitative analysis.

Optical Nanopore Sensors for Quantitative Analysis.

Nanopore sensors have received significant interest for the detection of clinically important biomarkers with single-molecule resolution. These sensors typically operate by detecting changes in the ionic current through a nanopore due to the translocation of an analyte. Recently, there has been interest in developing optical readout strategies for nanopore sensors for quantitative analysis. This is because they can utilize wide-field microscopy to independently monitor many nanopores within a high-density array. This significantly increases the amount of statistics that can be obtained, thus enabling the analysis of analytes present at ultralow concentrations. Here, we review the use of optical nanopore sensing strategies for quantitative analysis. We discuss optical nanopore sensing assays that have been developed to detect clinically relevant biomarkers, the potential for multiplexing such measurements, and techniques to fabricate high density arrays of nanopores with a view toward the use of these devices for clinical applications.

Influence of Five Drying Methods on Active Compound Contents and Bioactivities of Fresh Flowers from Syringa pubescens Turcz.

The flower of Syringa pubescens Turcz. is used in Chinese folk medicine and also as a flower tea for healthcare. The effects of five drying methods on the active compound contents, the antioxidant abilities, anti-inflammatory properties and enzyme inhibitory activities were evaluated. The plant materials were treated using shade-drying, microwave-drying, sun-drying, infrared-drying and oven-drying. The seven active compounds were simultaneously determined using an HPLC method. Furthermore, the chemical profile was assessed using scanning electron microscopy, ultraviolet spectroscopy and infrared spectroscopy. The antioxidant capacities and protective effects on L02 cells induced with hydrogen peroxide were measured. The anti-inflammatory effects on lipopolysaccharide-induced RAW264.7 cells were investigated. The enzyme inhibitory activities were determined against α-amylase, α-glucosidase cholinesterases and tyrosinase. The results indicated that drying methods had significant influences on the active compound contents and biological properties. Compared with other samples, the OD samples possessed low IC50 values with 0.118 ± 0.004 mg/mL for DPPH radical, 1.538 ± 0.0972 for hydroxyl radical and 0.886 ± 0.199 mg/mL for superoxide radical, while the SHD samples had stronger reducing power compared with other samples. The SHD samples could be effective against H2O2-induced injury on L02 cells by the promoting of T-AOC, GSH-PX, SOD and CAT activities and the reducing of MDA content compared with other samples. Furthermore, SPF samples, especially the SHD sample, could evidently ameliorate inflammation through the inhibition of IL-6, IL-1ß and TNF-α expression. All the studied SPF samples exhibited evidently inhibitory effects on the four enzymes. The IC50 values of inhibitory activity on α-glucosidase and α-amylase from SHD sample were 2.516 ± 0.024 and 0.734 ± 0.034 mg/mL, respectively. SD samples had potential inhibitory effects on cholinesterases and tyrosinase with IC50 values of 3.443 ± 0.060 and 1.732 ± 0.058 mg/mL. In consideration of active compound contents and biological activities, it was recommended that SHD and SD be applied for drying SPF at an industrial scale.

Spiers Memorial Lecture. Next generation nanoelectrochemistry: the fundamental advances needed for applications.

Nanoelectrochemistry, where electrochemical processes are controlled and investigated with nanoscale resolution, is gaining more and more attention because of the many potential applications in energy and sensing and the fact that there is much to learn about fundamental electrochemical processes when we explore them at the nanoscale. The development of instrumental methods that can explore the heterogeneity of electrochemistry occurring across an electrode surface, monitoring single molecules or many single nanoparticles on a surface simultaneously, have been pivotal in giving us new insights into nanoscale electrochemistry. Equally important has been the ability to synthesise or fabricate nanoscale entities with a high degree of control that allows us to develop nanoscale devices. Central to the latter has been the incredible advances in nanomaterial synthesis where electrode materials with atomic control over electrochemically active sites can be achieved. After introducing nanoelectrochemistry, this paper focuses on recent developments in two major application areas of nanoelectrochemistry; electrocatalysis and using single entities in sensing. Discussion of the developments in these two application fields highlights some of the advances in the fundamental understanding of nanoelectrochemical systems really driving these applications forward. Looking into our nanocrystal ball, this paper then highlights: the need to understand the impact of nanoconfinement on electrochemical processes, the need to measure many single entities, the need to develop more sophisticated ways of treating the potentially large data sets from measuring such many single entities, the need for more new methods for characterising nanoelectrochemical systems as they operate and the need for material synthesis to become more reproducible as well as possess more nanoscale control.

Mitral valve regurgitation is associated with left atrial fibrosis in patients with atrial fibrillation.

BACKGROUND: Low voltage zones (LVZ) are associated with poor outcomes in patients with atrial fibrillation (AF). The APPLE and DR-FLASH scores predict LVZ in patients undergoing catheter ablation. This study aimed to assess the relationship of mitral valve regurgitation (MR) and LVZ after adjusting for APPLE or DR-FLASH scores. METHODS: This was a retrospective study on patients with AF who underwent their first catheter ablation. All patients underwent a transthoracic echocardiographic examination before ablation. The APPLE and DR-FLASH scores were calculated at baseline. LVZ determined by high-density mapping was defined as bipolar voltage amplitude <0.5 mV. LVZ presence was defined as LVZ covering >5% of the left atrial surface area. RESULTS: Altogether, 152 patients (mean age 62.0 ± 10.8 years, 65.8% men, and 36.2% with persistent AF) were included. Of the 152 patients, 47 (30.9%) had LVZ. The patients with LVZ had more moderate-to-severe MR (17.0% vs. 3.8%, P = 0.014) and higher APPLE scores (1.7 ± 1.1 vs. 1.2 ± 1.1, P = 0.009) and DR-FLASH scores (3.0 ± 1.5 vs. 2.4 ± 1.4, P = 0.010). Using multivariate logistic regression analysis, we found moderate-to-severe MR was related to LVZ presence after adjusting for the APPLE (OR 4.040, P = 0.034) or DR-FLASH (OR 4.487, P = 0.020) scores. Furthermore, moderate-to-severe MR had an incremental predictive value for LVZ presence in addition to the APPLE (P = 0.03) or DR-FLASH (P = 0.02) scores. CONCLUSION: In patients with AF, MR severity was related to LVZ after adjusting the APPLE score or DR-FLASH score.