Impaired distal renal potassium handling in streptozotocin-induced diabetic mice.

Diabetes is closely associated with K+ disturbances during disease progression and treatment. However, it remains unclear whether K+ imbalance occurs in diabetes with normal kidney function. In this study, we examined the effects of dietary K+ intake on systemic K+ balance and renal K+ handling in streptozotocin (STZ)-induced diabetic mice. The control and STZ mice were fed low or high K+ diet for 7 days to investigate the role of dietary K+ intake in renal K+ excretion and K+ homeostasis and to explore the underlying mechanism by evaluating K+ secretion-related transport proteins in distal nephrons. K+-deficient diet caused excessive urinary K+ loss, decreased daily K+ balance, and led to severe hypokalemia in STZ mice compared with control mice. In contrast, STZ mice showed an increased daily K+ balance and elevated plasma K+ level under K+-loading conditions. Dysregulation of the NaCl cotransporter (NCC), epithelial Na+ channel (ENaC), and renal outer medullary K+ channel (ROMK) was observed in diabetic mice fed either low or high K+ diet. Moreover, amiloride treatment reduced urinary K+ excretion and corrected hypokalemia in K+-restricted STZ mice. On the other hand, inhibition of SGLT2 by dapagliflozin promoted urinary K+ excretion and normalized plasma K+ levels in K+-supplemented STZ mice, at least partly by increasing ENaC activity. We conclude that STZ mice exhibited abnormal K+ balance and impaired renal K+ handling under either low or high K+ diet, which could be primarily attributed to the dysfunction of ENaC-dependent renal K+ excretion pathway, despite the possible role of NCC.NEW & NOTEWORTHY Neither low dietary K+ intake nor high dietary K+ intake effectively modulates renal K+ excretion and K+ homeostasis in STZ mice, which is closely related to the abnormality of ENaC expression and activity. SGLT2 inhibitor increases urinary K+ excretion and reduces plasma K+ level in STZ mice under high dietary K+ intake, an effect that may be partly due to the upregulation of ENaC activity.

Photocleavable DNA Nanotube-Based Dual-Amplified Resonance Rayleigh Scattering System for MicroRNA Detection Incorporating Molecular Computing-Cascaded Keypad Lock Functionality.

Cascade molecular events in complex systems are of vital importance for enhancing molecular diagnosis and information processing. However, the conversion of a cascaded biosensing system into a multilayer encrypted molecular keypad lock remains a significant challenge in the development of molecular logic devices. In this study, we present a photocleavable DNA nanotube-based dual-amplified resonance Rayleigh scattering (RRS) system for detecting microRNA-126 (miR-126). The cascading dual-amplification biosensing system provides a multilayer-encrypted prototype with the functionality of a molecular computing cascade keypad lock. RRS signals were greatly amplified by using photocleavable DNA nanotubes and enzyme-assisted strand displacement amplification (SDA). In the presence of miR-126, enzyme-assisted SDA produced numerous identical nucleotide fragments as the target, which were then specifically attached to magnetic beads through the DNA nanotube by using a Y-shaped DNA scaffold. Upon ultraviolet irradiation, the DNA nanotube was released into the solution, resulting in an increase in the intensity of the RRS signal. This strategy demonstrated a low limit of detection (0.16 fM) and a wide dynamic range (1 fM to 1 nM) for miR-126. Impressively, the enzyme-assisted SDA offers a molecular computing model for generating the target pool, which serves as the input element for unlocking the system. By cascading the molecular computing process, we successfully constructed a molecular keypad lock with a multilevel authentication technique. The proposed system holds great potential for applications in molecular diagnosis and information security, indicating significant value in integrating molecular circuits for intelligent sensing.

A Highly Sensitive and Selective Fluorescent Sensor for Folic Acid Detection Based on D-penicillamine Stabilized Ag/Cu Alloy Nanoclusters.

In this work, a highly sensitive and selective method for detecting folic acid (FA) was developed using D-penicillamine (DPA) stabilized Ag/Cu alloy nanoclusters (DPA@Ag/Cu NCs). The yellow emission of DPA@Ag/Cu NCs was found to be quenched upon the addition of FA to the system. The fluorescence intensity quenching value demonstrated a linear relationship with FA concentrations ranging from 0.01 to 1200 µM, with a limit of detection (LOD) of 5.3 nM. Furthermore, the detection mechanism was investigated through various characterization analyses, including high resolution transmission electron microscopy, fluorescence spectra, ultraviolet-visible absorption spectra, and fluorescence lifetime. The results indicated that the fluorescence quenching induced by FA was a result of electron transfer from FA to the ligands of DPA@Ag/Cu NCs. The selectivity of the FA sensor was also evaluated, showing that common amino acids and inorganic ions had minimal impact on the detection of FA. Moreover, the standard addition method was successfully applied to detect FA in human serum, chewable tablets and FA tablets with promising results. The use of DPA@Ag/Cu NCs demonstrates significant potential for detecting FA in complex biological samples.

DNA Tile and Invading Stacking Primer-Assisted CRISPR-Cas12a Multiple Amplification System for Entropy-Driven Electrochemical Detection of MicroRNA with Tunable Sensitivity.

Conventional electrochemical detection of microRNA (miRNA) encounters issues of poor sensitivity and fixed dynamic range. Here, we report a DNA tile and invading stacking primer-assisted CRISPR-Cas12a multiple amplification strategy to construct an entropy-controlled electrochemical biosensor for the detection of miRNA with tunable sensitivity and dynamic range. To amplify the signal, a cascade amplification of the CRISPR-Cas12a system along with invading stacking primer signal amplification (ISPSA) was designed to detect trace amounts of miRNA-31 (miR-31). The target miR-31 could activate ISPSA and produce numerous DNAs, triggering the cleavage of the single-stranded linker probe (LP) that connects a methylene blue-labeled DNA tile with a DNA tetrahedron to form a Y-shaped DNA scaffold on the electrode. Based on the decrease of current, miR-31 can be accurately and efficiently detected. Impressively, by changing the loop length of the LP, it is possible to finely tune the entropic contribution while keeping the enthalpic contribution constant. This strategy has shown a tunable limit of detection for miRNA from 0.31 fM to 0.56 pM, as well as a dynamic range from ∼2200-fold to ∼270,000-fold. Moreover, it demonstrated satisfactory results in identifying cancer cells with a high expression of miR-31. Our strategy broadens the application of conventional electrochemical biosensing and provides a tunable strategy for detecting miRNAs at varying concentrations.

Magnetically Controlled and Addressable Photoelectrochemical Sensor Array with Self-Calibration for the Label-Free Detection of Amyloid ß-Proteins.

A label-free addressable photoelectric immunosensor array was designed for the detection of amyloid ß-proteins based on magnetic separation and self-calibration strategies. In this paper, Na2Ti6O13 with a flower-like morphology was prepared by the hydrothermal method; after continuously combining Fe3O4 and CdS, it was endowed with magnetism and better photoelectric activity. Subsequently, a series of reactions occurred in the solution, and the magnetic separation method was used to enrich the target. On the other hand, the ITO glass was separated into eight sites (2 × 4) using magnets, and a light shield was utilized to prevent light exposure, resulting in addressable and continuous detection. After the uniform preparation of magnetic photoelectric materials and precise control of testing conditions, the relative errors among different sites have been effectively reduced. Moreover, incorporating a self-calibration strategy has allowed the sensor array to achieve greater accuracy. The proposed photoelectrochemical biosensor exhibits a good relationship with amyloid ß-protein ranging from 0.01 to 100 ng mL-1 with a limit of detection of 1.1 pg mL-1 and exhibits excellent specificity, reproducibility, and stability.

d-Penicillamine@Ag/Cu Nanocluster-Based Fluorescent Nanoneuron for Logic Screening Phosphonate-Type Organophosphate Pesticides and Steganographically Encrypting Information.

Organophosphate pesticides are used in agriculture due to their high effectiveness and low persistence in eradicating insects and pests. However, conventional detection methods encounter the limitation of undesired detection specificity. Thus, screening phosphonate-type organophosphate pesticides (OOPs) from their analogues, phosphorothioate organophosphate pesticides (SOPs), remains a challenge. Here, we reported a d-penicillamine@Ag/Cu nanocluster (DPA@Ag/Cu NCs)-based fluorescence assay to screen OOPs from 21 kinds of organophosphate pesticides, which can be used for logic sensing and information encryption. Acetylthiocholine chloride was enzymatically split by acetylcholinesterase (AChE) to produce thiocholine, which reduced the fluorescence of DPA@Ag/Cu NCs due to the transmission of electrons from DPA@Ag/Cu NCs donor to the thiol group acceptor. Impressively, OOPs acted as an AChE inhibitor and retained the high fluorescence of DPA@Ag/Cu NCs due to the stronger positive electricity of the phosphorus atom. Conversely, SOPs possessed weak toxicity to AChE, which led to low fluorescence intensity. By setting 21 kinds of organophosphate pesticides as the inputs and the fluorescence of the resulting products as the outputs, DPA@Ag/Cu NCs could serve as a fluorescent nanoneuron to construct Boolean logic tree and complex logic circuit for molecular computing. As a proof of concept, by converting the selective response patterns of DPA@Ag/Cu NCs into binary strings, molecular crypto-steganography for encoding, storing, and concealing information was successfully achieved. This study is expected to advance the progress and practical application of nanoclusters in the area of logic detection and information security while also enhancing the relationship between molecular sensors and the world of information.

Photocontrollable DNA Walker-Based Molecular Circuit for the Tunable Detection of MicroRNA-21 Using Metal-Organic Frameworks as Label-Free Fluorescence Tags.

Tunable detection of microRNA is crucial to meet the desired demand for sample species with varying concentrations in clinical settings. Herein, we present a DNA walker-based molecular circuit for the detection of miRNA-21 (miR-21) with tunable dynamic ranges and sensitivity levels ranging from fM to pM. The phosphate-activated fluorescence of UiO-66-NH2 metal-organic framework nanoparticles was used as label-free fluorescence tags due to their competitive coordination effect with the Zr atom, which significantly inhibited the ligand-to-metal charge transfer. To achieve a tunable detection performance for miR-21, the ultraviolet sensitive o-nitrobenzyl was induced as a photocleavable linker, which was inserted at various sites between the loop and the stem of the hairpin probe to regulate the DNA strand displacement reaction. The dynamic range can be precisely regulated from 700- to 67,000-fold with tunable limits of detection ranging from 2.5 fM to 36.7 pM. Impressively, a Boolean logic tree and complex molecular circuit were constructed for logic computation and cancer diagnosis in clinical blood samples. This intelligent biosensing method presents a powerful solution for converting complex biosensing systems into actionable healthcare decisions and will facilitate early disease diagnosis.

Distal p-benzylic deuteration via N-heterocyclic carbene catalyzed ring opening of p-cyclopropylbenzaldehydes.

Deuterium incorporation at selective sites of organic compounds has long attracted the interest of the pharmaceutical industry. Here, we present a distal p-benzylic deuteration via N-heterocyclic carbene catalyzed ring-opening of cyclopropylbenzaldehydes with MeOD as the deuterium source. The corresponding 4-alkylbenzoates with high deuterium incorporation at the benzylic position were obtained in good yields. The stable benzylic deuterium remained intact for further chemical transformations.

Survey of the Prosthogonimus spp. metacercariae infection in the second intermediate host dragonfly in Heilongjiang Province, China.

Prosthogonimiasis poses a threat to the reproductive system of poultry and wild birds, which are the definitive hosts of the parasite causing this disease. However, the parasite infection of the second intermediate host (dragonfly), the primary vector of this pathogen, is rarely reported. In this study, the prevalence of Prosthogonimus infection in dragonflies was investigated from June 2019 to October 2022 in Heilongjiang Province, northeast China. The species of metacercariae isolated from dragonfly were identified by morphological characteristics, molecular biology techniques, and animal infection experiments. The results showed that 11 species of dragonflies and one damselfly were identified and among six of the dragonflies infected by Prosthogonimus metacercariae, Sympetrum depressiusculum (28.53%) had the highest infection rate among all positive dragonflies, followed by Sympetrum vulgatum (27.86%) and Sympetrum frequens (20.99%), which are preferred hosts, and the total prevalence was 20.39% (2061/10,110) in Heilongjiang Province. Three species of Prosthogoniumus metacercariae were isolated, including Prosthogonimus cuneatus, Prosthogonimus pullucidus, and Prosthogonimus sp., among which P. cuneatus was the dominant species in dragonflies in Heilongjiang Province. This is the first report on the prevalence of Prosthogonimus in dragonflies in China, which provides baseline data for the control of prosthogonimiasis in Heilongjiang Province and a reference for the prevention of prosthogonimiasis in other areas of China.

Characterizing gas-liquid two-phase flow behavior using complex network and deep learning.

Gas-liquid two-phase flow is polymorphic and unstable, and characterizing its flow behavior is a major challenge in the study of multiphase flow. We first conduct dynamic experiments on gas-liquid two-phase flow in a vertical tube and obtain multi-channel signals using a self-designed four-sector distributed conductivity sensor. In order to characterize the evolution of gas-liquid two-phase flow, we transform the obtained signals using the adaptive optimal kernel time-frequency representation and build a complex network based on the time-frequency energy distribution. As quantitative indicators, global clustering coefficients of the complex network at various sparsity levels are computed to analyze the dynamic behavior of various flow structures. The results demonstrate that the proposed approach enables effective analysis of multi-channel measurement information for revealing the evolutionary mechanisms of gas-liquid two-phase flow. Furthermore, for the purpose of flow structure recognition, we propose a temporal-spatio convolutional neural network and achieve a classification accuracy of 95.83%.

Interconnected ordinal pattern complex network for characterizing the spatial coupling behavior of gas-liquid two-phase flow.

The complex phase interactions of the two-phase flow are a key factor in understanding the flow pattern evolutional mechanisms, yet these complex flow behaviors have not been well understood. In this paper, we employ a series of gas-liquid two-phase flow multivariate fluctuation signals as observations and propose a novel interconnected ordinal pattern network to investigate the spatial coupling behaviors of the gas-liquid two-phase flow patterns. In addition, we use two network indices, which are the global subnetwork mutual information (I) and the global subnetwork clustering coefficient (C), to quantitatively measure the spatial coupling strength of different gas-liquid flow patterns. The gas-liquid two-phase flow pattern evolutionary behaviors are further characterized by calculating the two proposed coupling indices under different flow conditions. The proposed interconnected ordinal pattern network provides a novel tool for a deeper understanding of the evolutional mechanisms of the multi-phase flow system, and it can also be used to investigate the coupling behaviors of other complex systems with multiple observations.

Criticality in transient behavior of coupled oscillator system toward chimera and synchronization.

Chimera states in spatiotemporal dynamical systems have been investigated in physical, chemical, and biological systems, while how the system is steering toward different final destinies upon spatially localized perturbation is still unknown. Through a systematic numerical analysis of the evolution of the spatiotemporal patterns of multi-chimera states, we uncover a critical behavior of the system in transient time toward either chimera or synchronization as the final stable state. We measure the critical values and the transient time of chimeras with different numbers of clusters. Then, based on an adequate verification, we fit and analyze the distribution of the transient time, which obeys power-law variation process with the increase in perturbation strengths. Moreover, the comparison between different clusters exhibits an interesting phenomenon, thus we find that the critical value of odd and even clusters will alternatively converge into a certain value from two sides, respectively, implying that this critical behavior can be modeled and enabling the articulation of a phenomenological model.

Fluorescent aptasensor based on the MNPs-CRISPR/Cas12a-TdT for the determination of nasopharyngeal carcinoma-derived exosomes.

A fluorescence aptasensor based on taking the advantage of the combination of magnetic nanoparticles (MNPs), terminal deoxynucleotidyl transferase (TdT), and CRISPR/Cas12a was developed for the determination of nasopharyngeal carcinoma (NPC)-derived exosomes. The MNPs can eliminate background interference due to their magnetic separation capability. TdT can form an ultra-long polynucleotide tail which can bind with multiple crRNA, generating a signal amplification effect. The trans-cleavage activity of CRISPR/Cas12a can be specifically triggered via the crRNA binding with DNA, resulting in the bi-labeled DNA reporter with fluorophore and quencher being cleaved. The excitation wavelength of the fluorescence spectra was 490 nm. Fluorescence spectra with emission wavelengths ranging from 511 to 600 nm were collected. Under the optimization condition, the fabricated fluorescence aptasensor for NPC-derived exosome determination exhibited excellent sensitivity and specificity, with the linear range between 500 to 5 × 104 particles mL-1 and the limit of detection of 100 particles mL-1. It can be used for the determination of NPC-derived exosomes in clinical samples, which has a considerable clinical potential and prospect.

Underestimated contribution of fugitive emission to VOCs in pharmaceutical industry based on pollution characteristics, odorous activity and health risk assessment.

Fugitive emission has been becoming an important source of volatile organic compounds (VOCs) in pharmaceutical industry, but the exact contribution of fugitive emission remains incompletely understood. In present study, pollution characteristics, odorous activity and health risk of stack and fugitive emissions of VOCs from four functional units (e.g., workshop, sewage treatment station, raw material storage and hazardous waste storage) of three representative pharmaceutical factories were investigated. Workshop was the dominant contributor to VOCs of fugitive emission in comparison with other functional units. Extreme high concentration of VOCs from fugitive emission in unsealed workshop (94.87 mg/m3) was observed relative to sealed one (1.18 mg/m3), accounting for 31% and 5% of total VOCs, respectively. Fugitive emission of VOCs in the unsealed workshop mainly consisted of n-hexane, 1-hexene and dichloromethane. Odorous activity indexes and non-cancer hazard ratios of these VOCs from fugitive emission in the unsealed workshop were as high as that from stack exhaust. Furthermore, cancer risk of dichloromethane from fugitive emission and stack exhaust was up to (1.6-1.8) × 10-5. Odorous activity or health risk index of the VOCs from fugitive emission was up to 13 or 11 times of the corresponding threshold value, posing remarkable health threat on pharmaceutical workers. Our findings highlighted the possibly underestimated contribution of fugitive emission on VOCs in the pharmaceutical industry.

Enantioselective N-Heterocyclic Carbene Catalyzed α-Oxidative Coupling of Enals with Carboxylic Acids Using an Iodine(III) Reagent.

The enantioselective α-oxidative coupling of enals with carboxylic acids was developed via the umpolung of an NHC-bound enolate with an iodine(III) reagent. The corresponding α-acyloxyl-ß,γ-unsaturated esters were afforded in good yields, with high regio- and enantioselectivities. The key step of the reaction involves the formation of enol iodine(III) intermediate from the enolate with iodosobenzene, which changes the polarity of α-carbon of the enal from nucleophilic to electrophilic, and thus facilitates the subsequent addition of carboxylate.

Bifunctional NHC-Catalyzed Remote Enantioselective Mannich-type Reaction of 5-(Chloromethyl)furfural via Trienolate Intermediates.

N-heterocyclic carbene (NHC)-catalyzed enantioselective Mannich-type reactions of the biomass-derived platform compound 5-(chloromethyl)furfural (CMF) with imines were developed. A series of high-value-added chiral amines were afforded in good to high yields with excellent regio- and enantioselectivities. The bifunctional NHC derived from ʟ-pyroglutamic acid efficiently steered the remote addition of the trienolate intermediate to the imine in a highly stereocontrolled manner. This represents the first enantioselective reaction proceeding via an NHC-bound trienolate intermediate.

Label-Free Resonance Rayleigh Scattering Amplification for Lipopolysaccharide Detection and Logical Circuit by CRISPR/Cas12a-Driven Guanine Nanowire Assisted Non-Cross-Linking Hybridization Chain Reaction.

Although the CRISPR/Cas system has pioneered a new generation of analytical techniques, there remain many challenges in developing a label-free, accurate, and reliable CRISPR/Cas-based assay for reporting the levels of low abundance biomolecules in complex biological samples. Here, we reported a novel CRISPR-derived resonance Rayleigh scattering (RRS) amplification strategy and logical circuit based on a guanine nanowire (G-wire) assisted non-cross-linking hybridization chain reaction (GWancHCR) for label-free detection of lipopolysaccharide (LPS). In the presence of a target, the protospacer-adjacent motif-inserted aptamer is rationally designed to specifically combine with LPS rather than Cas12a, suppressing the trans-cleavage activity of CRISPR/Cas12a and retaining the reporter probes to trigger non-cross-linking aggregation. Owing to the automatic hybridization chain reaction (HCR), in the presence of Mg2+, the released G-quadruplex sequence aggregated to assemble the G-wire superstructure through non-cross-linking. As a result, a dramatically amplified RRS intensity is observed, allowing for reporting LPS levels in a low detection limit of 0.17 pg/mL and a wide linear range among 1.0-100.0 ng/mL. Moreover, this reaction event is capable of programming to perform classical Boolean logic tree analysis, including basic logic computing and complex integrated logic circuits. This study comprehensively analyzed with respect to information flow, matter (molecular events), and energy (RRS), revealing the potential promise in designing of molecular-level "Internet of Things", intelligent computing, and sensing systems.

Photoresponsive DNA-Modified Magnetic Bead-Assisted Rolling Circle Amplification-Driven Visual Photothermal Sensing of Escherichia coli.

The development of facile, reliable, and accurate assays for pathogenic bacteria is critical to environmental pollution surveillance, traceability analysis, prevention, and control. Here, we proposed a rolling circle amplification (RCA) strategy-driven visual photothermal smartphone-based biosensor for achieving highly sensitive monitoring of Escherichia coli (E. coli) in environmental media. In this design, E. coli could specifically bind with its recognition aptamer for initiating the RCA process on a magnetic bead (MB). Owing to the cleaving of UV irradiation toward photoresponsive DNA on MB, the RCA products were released to further hybridize with near-infrared excited CuxS-modified DNA probes. As a result, the photothermal signal was enhanced by RCA, while the background was decreased by UV irradiation and magnetic separation. The correspondingly generated photothermal signals were unambiguously recorded on a smartphone, allowing for an E. coli assay with a low detection limit of 1.8 CFU/mL among the broad linear range from 5.0 to 5.0 × 105 CFU/mL. Significantly, this proposed biosensor has been successfully applied to monitor the fouling levels of E. coli in spring water samples with acceptable results. This study holds great prospects by integrating a RCA-driven photothermal amplification strategy into a smartphone to develop accurate, reliable, and efficient analytical platforms against pathogenic bacteria pollutions for safeguarding environmental health.

SlMIR164A regulates fruit ripening and quality by controlling SlNAM2 and SlNAM3 in tomato.

MiRNAs are important posttranscriptional regulators of plant development. Many miRNAs, such as the conserved miR164 species, are encoded by families of MIRNA genes, but the specific roles of individual MIRNA genes are largely undefined. Here, we characterize the functions and regulatory mechanisms of SlMIR164A, one of the primary genes of Sly-miR164, in tomato. We show that SlMIR164A is preferentially expressed at late stages of fruit development and plays a vital role in controlling fruit ripening and quality. Loss of function of SlMIR164A by CRISPR/Cas9-mediated mutagenesis results in accelerated fruit ripening and enhanced chloroplast development, which leads to altered sugar and organic acid contents and affects the nutritional quality of fruits. We also show that SlMIR164A modulates fruit ripening and quality through specific target genes, SlNAM2 and SlNAM3, which control key regulators of chloroplast function and fruit ripening processes. MIR164 genes have been shown to play conserved roles in regulating organ ageing, such as leaf senescence and fruit ripening, in a variety of plants, but whether and how their family members in tomato exert the same function remain to be elucidated. Our results reveal a previously undiscovered role of SlMIR164A in ripening control, which will further our understanding of the actions of MIR164 family, as well as the mechanisms of fruit ripening and quality control in tomato. Moreover, as loss of SlMIR164A exhibits minor impacts on organ morphology, our results can be leveraged in tomato breeding for specific manipulation of fruit ripening and quality to facilitate tomato improvement in agriculture.

ε-Benzylation via Cooperative Photoredox and N-Heterocyclic Carbene Catalysis.

The ε-benzylation of γ-alkenyl-γ-oxidized enals via dual photoredox and N-heterocyclic carbene catalysis has been developed, affording the corresponding ε-benzyl-α,ß-γ,δ-bisunsaturated esters in moderate to good yields with exclusive regioselectivities. The reaction is proposed via the generation of benzyl radical under photocatalysis, followed by its addition to an NHC-bound trienolate intermediate.