Design of customized coronavirus receptors.

Although coronaviruses use diverse receptors, the characterization of coronaviruses with unknown receptors has been impeded by a lack of infection models1,2. Here we introduce a strategy to engineer functional customized viral receptors (CVRs). The modular design relies on building artificial receptor scaffolds comprising various modules and generating specific virus-binding domains. We identify key factors for CVRs to functionally mimic native receptors by facilitating spike proteolytic cleavage, membrane fusion, pseudovirus entry and propagation for various coronaviruses. We delineate functional SARS-CoV-2 spike receptor-binding sites for CVR design and reveal the mechanism of cell entry promoted by the N-terminal domain-targeting S2L20-CVR. We generated CVR-expressing cells for 12 representative coronaviruses from 6 subgenera, most of which lack known receptors, and show that a pan-sarbecovirus CVR supports propagation of a propagation-competent HKU3 pseudovirus and of authentic RsHuB2019A3. Using an HKU5-specific CVR, we successfully rescued wild-type and ZsGreen-HiBiT-incorporated HKU5-1 (LMH03f) and isolated a HKU5 strain from bat samples. Our study demonstrates the potential of the CVR strategy for establishing native receptor-independent infection models, providing a tool for studying viruses that lack known susceptible target cells.

ILC2-derived LIF licences progress from tissue to systemic immunity.

Migration and homing of immune cells are critical for immune surveillance. Trafficking is mediated by combinations of adhesion and chemokine receptors that guide immune cells, in response to chemokine signals, to specific locations within tissues and the lymphatic system to support tissue-localized immune reactions and systemic immunity1,2. Here we show that disruption of leukaemia inhibitory factor (LIF) production from group 2 innate lymphoid cells (ILC2s) prevents immune cells leaving the lungs to migrate to the lymph nodes (LNs). In the absence of LIF, viral infection leads to plasmacytoid dendritic cells (pDCs) becoming retained in the lungs where they improve tissue-localized, antiviral immunity, whereas chronic pulmonary allergen challenge leads to marked immune cell accumulation and the formation of tertiary lymphoid structures in the lung. In both cases immune cells fail to migrate to the lymphatics, leading to highly compromised LN reactions. Mechanistically, ILC2-derived LIF induces the production of the chemokine CCL21 from lymphatic endothelial cells lining the pulmonary lymphatic vessels, thus licensing the homing of CCR7+ immune cells (including dendritic cells) to LNs. Consequently, ILC2-derived LIF dictates the egress of immune cells from the lungs to regulate tissue-localized versus systemic immunity and the balance between allergen and viral responsiveness in the lungs.

Multifunctional Manganese-Nucleotide Laccase-Mimicking Nanozyme for Degradation of Organic Pollutants and Visual Assay of Epinephrine via Smartphone.

As a natural green catalyst, laccase has extensive application in the fields of environmental monitoring and pollutant degradation. However, susceptibility to environmental influences and poor reusability seriously hinder its application. To address these concerns, for the first time, manganese ion replaced copper ion as the active center to coordinate with guanosine monophosphate (GMP) for synthesizing mimic laccase with high catalytic activity. Compared with natural laccase, the laccase-like nanozyme (Mn-GMPNS) demonstrated superior thermal stability, acid-base resistance, salt tolerance, reusability, and substrate universality. Benefiting from the high catalytic activity of Mn-GMPNS, epinephrine, a significant neurotransmitter and hormone associated with numerous diseases, was visually detected within 10 min and a portable assay by smartphone. More encouragingly, Mn-GMPNS can efficiently degrade dye pollutants, achieving a decolorization rate over 70% within 30 min. Thus, the coordination between manganese ion and nucleotide demonstrated the potential in rational design of nanozymes with high catalytic activity, low cost, good stability, and good biocompatibility.

One-Step Cooperative Growth of High Reaction Kinetics Composite Homogeneous Core-Shell Heterostructure.

Reaction kinetics can be improved by the enhanced electrical contact between different components growing symbiotically. But so far, due to the necessity for material synthesis conditions match, the component structures of cooperative growth are similar, and the materials are of the same type. The collaborative growth of high-reaction kinetics composite homogeneous core-shell heterostructure between various materials is innovatively proposed with different structures in one step. The NiCo-LDH and PPy successfully symbiotically grow on activated carbon fiber fabric in one step. The open channel structure of the NiCo-LDH nanosheets is preserved while PPy effectively wrapped around the NiCo-LDH. The well-defined nanostructure with abundant active sites and convenient ion diffusion paths is favorable for electrolyte entry into the entire nanoarrays. In addition, owing to the enhanced electronic interaction between different components through XPS analysis, the NiCo-LDH@PPy electrode shows outstanding reaction kinetics and structural stability. The as-synthesized NiCo-LDH@PPy exhibited excellent super-capacitive storage capabilities, robust capacitive activity, and good rate survival. Furthermore, an asymmetric supercapacitor (ASC) device made of NiCo-LDH@PPy and activated carbon (AC) is able to maintain a long cycle life while achieving high power and energy densities.

Mechanistic Insights into the N-Hydroxylations Catalyzed by the Binuclear Iron Domain of SznF Enzyme: Key Piece in the Synthesis of Streptozotocin.

SznF, a member of the emerging family of heme-oxygenase-like (HO-like) di-iron oxidases and oxygenases, employs two distinct domains to catalyze the conversion of Nω-methyl-L-arginine (L-NMA) into N-nitroso-containing product, which can subsequently be transformed into streptozotocin. Using unrestricted density functional theory (UDFT) with the hybrid functional B3LYP, we have mechanistically investigated the two sequential hydroxylations of L-NMA catalyzed by SznF's binuclear iron central domain. Mechanism B primarily involves the O-O bond dissociation, forming Fe(IV)=O, induced by the H+/e- introduction to the FeA side of µ-1,2-peroxo-Fe2(III/III), the substrate hydrogen abstraction by Fe(IV)=O, and the hydroxyl rebound to the substrate N radical. The stochastic addition of H+/e- to the FeB side (mechanism C) can transition to mechanism B, thereby preventing enzyme deactivation. Two other competing mechanisms, involving the direct O-O bond dissociation (mechanism A) and the addition of H2O as a co-substrate (mechanism D), have been ruled out.

Intramolecular aptamer switches.

Aptamer switches as effective biosensing tools have become a focal point of research in engineered aptasensors. Intramolecular aptamer switches are more versatile, affordable, and simpler than classical "open-close" and strand displacement-based aptamer switches. Recently, many new aptamers with an overall hairpin structure have been reported. In this study, intramolecular aptamer switches were developed by adding new base pairs to the end of aptamers. The additional nucleotides can pair with the internal domains of the aptamer, causing a change in its conformation from the original secondary structure without a target. When a target binds to an aptamer, a marked change in the structure of the aptamer is expected. As models for testing this intramolecular aptamer switch idea, aptamers of oxytetracycline (OTC), 17ß-estradiol (E2), and adenosine were employed. When the additional base pairs are too long, binding the target to the aptamer becomes more challenging. This research offers valuable insights into the development of intramolecular aptamer switches and their potential applications in biosensor design.

Dehydrative alkynylation of 3-hydroxyisoindolinones with terminal alkynes for the synthesis of 3-alkynylated 3,3-disubstituted isoindolinones.

A brand-new procedure for the synthesis of 3-alkynylated 3,3-disubstituted isoindolinones has been disclosed via a HOTf or Fe(OTf)3-catalyzed dehydrative alkynylation of 3-hydroxyisoindolinones with terminal alkynes. Aryl, alkenyl and alkyl terminal alkynes are suitable to couple with a broad range of 3-hydroxyisoindolinones to afford the desired products in moderate to good yields. This protocol features the use of an inexpensive catalyst, mild reaction conditions, broad substrate scope and easy elaboration of the products.

The smallest Schwarzite carbon with only heptagonal carbon rings.

Carbon materials with full sp2-hybridized buckling is a major challenge pervading fundamental nanoscience and nanotechnology research. Carbon atoms that are sp2 hybridized prefer to form hexagonal rings, such as in carbon nanotubes and graphene, which are low-dimensional materials. The incorporation of heptagonal, octagonal, and/or larger rings into a hexagonal sp2 carbon meshwork has been identified as a strategy for assembling three-dimensional (3D) sp2 carbon crystals, and one of the typical representatives are Schwarzite carbons, which possess a negative surface Gaussian curvature as well as unique physical properties. Herein, a 3D Schwarzite carbon consisting of only sp2-buckled heptagonal carbon rings, which is referred to as Hepta-carbon, is proposed based on first-principles calculations. Hepta-carbon is mechanically and thermodynamically stable, and energetically more favourable than experimental graphdiyne, fullerene C20 and most Schwarzite carbons under ambient conditions. Molecular dynamics simulations indicate that Hepta-carbon exhibits high-temperature thermostability up to 1500 K. Band structure and mechanical property simulations indicate that Hepta-carbon is a semi-metallic material with electron conduction and exhibits impressive mechanical properties such as high strength with quasi-isotropy, high incompressibility similar to diamonds, elastic deformation behaviour under uniaxial stress, and high ductility. Hepta-carbon presents a porous network with a low mass density of 1.84 g cm-3 and connected channels with diameters of 3.3-6.1 Å. Theoretical simulations of gas adsorption energy demonstrate that Hepta-carbon can effectively adsorb and stabilize greenhouse gases, including N2O, CO2, CH4, and SF6.

DsbA-L ameliorates renal aging and renal fibrosis by maintaining mitochondrial homeostasis.

Renal fibrosis is the final pathological change in renal disease, and aging is closely related to renal fibrosis. Mitochondrial dysfunction has been reported to play an important role in aging, but the exact mechanism remains unclear. Disulfide-bond A oxidoreductase-like protein (DsbA-L) is mainly located in mitochondria and plays an important role in regulating mitochondrial function and endoplasmic reticulum (ER) stress. However, the role of DsbA-L in renal aging has not been reported. In this study, we showed a reduction in DsbA-L expression, the disruption of mitochondrial function and an increase in fibrosis in the kidneys of 12- and 24-month-old mice compared to young mice. Furthermore, the deterioration of mitochondrial dysfunction and fibrosis were observed in DsbA-L-/- mice with D-gal-induced accelerated aging. Transcriptome analysis revealed a decrease in Flt4 expression and inhibition of the PI3K-AKT signaling pathway in DsbA-L-/- mice compared to control mice. Accelerated renal aging could be alleviated by an AKT agonist (SC79) or a mitochondrial protector (MitoQ) in mice with D-gal-induced aging. In vitro, overexpression of DsbA-L in HK-2 cells restored the expression of Flt4, AKT pathway factors, SP1 and PGC-1α and alleviated mitochondrial damage and cell senescence. These beneficial effects were partially blocked by inhibiting Flt4. Finally, activating the AKT pathway or improving mitochondrial function with chemical reagents could alleviate cell senescence. Our results indicate that the DsbA-L/AKT/PGC-1α signaling pathway could be a therapeutic target for age-related renal fibrosis and is associated with mitochondrial dysfunction.

Trends and disparities in prevalence of cardiometabolic diseases by food security status in the United States.

BACKGROUND: Previous studies have demonstrated the association between food security and cardiometabolic diseases (CMDs), yet none have investigated trends in prevalence of CMDs by food security status in the United States (US). METHODS: Serial cross-sectional analysis of the US nationally representative data from National Health and Nutrition Examination Survey (1999-2018) was conducted among adults aged 20 years or older. Food security status was defined by the US Household Food Security Survey Module (full, marginal, low, and very low food security). We estimated the age-adjusted prevalence of CMDs including obesity, hypertension, diabetes, and coronary heart disease by food security status. Racial and ethnic disparities in age-adjusted prevalence of CMDs by food security status were also assessed. RESULTS: A total of 49,738 participants were included in this analysis (weighted mean age 47.3 years; 51.3% women). From 1999 to 2018, the age-adjusted prevalence of CMDs was lower in full food secure group as compared with other groups. For example, trends in hypertension decreased from 49.7% (47.5-51.8%) to 45.9% (43.8-48.0%) (P-trend = 0.002) among the full and from 54.2% (49.9-58.5%) to 49.7% (46.8-52.6%) (P-trend = 0.02) among the marginal but remained stable among the low at 49.7% (47.9-51.6%) and among the very low at 51.1% (48.9-53.3%) (P-interaction = 0.02). Prevalence of diabetes increased from 8.85% (8.15-9.60%) to 12.2% (11.1-13.5%) among the full (P-trend < 0.001), from 16.5% (13.2-20.4%) to 20.9% (18.6-23.5%) (P-trend = 0.045) among the marginal and from 14.6% (11.1-19.0%) to 20.9% (18.8-23.3%) (P-trend = 0.001) among the low but remained stable at 18.8% (17.0-20.9) among the very low (P-trend = 0.35) (P-interaction = 0.03). Racial and ethnic differences in prevalence of CMD by food security status were observed. For example, among individuals with full food secure status, the prevalence of diabetes was 9.08% (95% CI, 8.60-9.59%) for non-Hispanic whites, 17.3% (95% CI, 16.4-18.2%) for non-Hispanic blacks, 16.1% (95% CI, 15.0-17.4%) for Hispanics and 14.9% (95% CI, 13.3-16.7%) for others. CONCLUSIONS AND RELEVANCE: Prevalence of CMDs was greatest among those experiencing food insecurity, and food insecurity disproportionately affected racial/ethnic minorities. Disparities in CMD prevalence by food security status persisted or worsened, especially among racial/ethnic minorities.

Mobile-Delivered Mindfulness Intervention on Anxiety Level Among College Athletes: Randomized Controlled Trial.

BACKGROUND: College athletes are a group often affected by anxiety. Few interventional studies have been conducted to address the anxiety issues in this population. OBJECTIVE: We conducted a mobile-delivered mindfulness intervention among college athletes to study its feasibility and efficacy in lowering their anxiety level and improving their mindfulness (measured by the Five Facet Mindfulness Questionnaire [FFMQ]). METHODS: In April 2019, we recruited 290 college athletes from a public university in Shanghai, China, and 288 of them were randomized into an intervention group and a control group (closed trial), with the former (n=150) receiving a therapist-guided, smartphone-delivered mindfulness-based intervention and the latter receiving mental health promotion messages (n=138). We offered in-person instructions during the orientation session for the intervention group in a classroom, with the therapist interacting with the participants on the smartphone platform later during the intervention. We used generalized linear modeling and the intent-to-treat approach to compare the 2 groups' outcomes in dispositional anxiety, precompetition anxiety, and anxiety during competition, plus the 5 dimensions of mindfulness (measured by the FFMQ). RESULTS: Our intent-to-treat analysis and generalized linear modeling found no significant difference in dispositional anxiety, precompetition anxiety, or anxiety during competition. Only the "observation" facet of mindfulness measures had a notable difference between the changes experienced by the 2 groups, whereby the intervention group had a net gain of .214 yet fell short of reaching statistical significance (P=.09). Participants who specialized in group sports had a higher level of anxiety (ß=.19; SE=.08), a lower level of "nonjudgemental inner experience" in FFMQ (ß=-.07; SE=.03), and a lower level of "nonreactivity" (ß=-.138; SE=.052) than those specializing in individual sports. CONCLUSIONS: No significant reduction in anxiety was detected in this study. Based on the participant feedback, the time availability for mindfulness practice and session attendance for these student athletes in an elite college could have compromised the intervention's effectiveness. Future interventions among this population could explore a more student-friendly time schedule (eg, avoid final exam time) or attempt to improve cognitive and scholastic outcomes. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR1900024449; https://www.chictr.org.cn/showproj.html?proj=40865.

Geniposide modulates GSK3ß to inhibit Th17 differentiation and mitigate endothelial damage in intracranial aneurysm.

Intracranial aneurysm (IA) is a common cerebrovascular disease. Immune system disorders and endothelial dysfunction are essential mechanisms of its pathogenesis. This study aims to explore the therapeutic effect and mechanism of Geniposide (Gen) on IA, which has a protective impact on endothelial cells and cardiovascular and cerebrovascular diseases. IA mouse models were administered intraperitoneal injections of geniposide for 2 weeks following elastase injection into the right basal ganglia of the brain for intervention. The efficacy of Gen in treating IA was evaluated through pathological testing and transcriptome sequencing analysis of Willis ring vascular tissue. The primary mechanism of action was linked to the expression of GSK3ß in Th17 cells. The percentage of splenic Th17 cell differentiation in IA mice was significantly inhibited by Gen. GSK3ß/STAT3, and other pathway protein expression levels were also significantly inhibited by Gen. Additionally, TNF-α and IL-23 cytokine contents were significantly downregulated after Gen treatment. These results indicated that Gen significantly inhibited the percentage of Th17 cell differentiation, an effect that was reversed upon overexpression of the GSK3B gene. Furthermore, Gen-treated, Th17 differentiation-inducing cell-conditioned medium significantly up-regulated the expression of tight junction proteins ZO-1, Occludin, and Claudin-5 in murine aortic endothelial cells. Administering the GSK3ß inhibitor Tideglusib to IA mice alleviated the severity of IA disease pathology and up-regulated aortic tight junction protein expression. In conclusion, Gen inhibits Th17 cell differentiation through GSK3ß, which reduces endothelial cell injury and up-regulates tight junction protein expression.

Design and Testing of a Seedling Pick-Up Device for a Facility Tomato Automatic Transplanting Machine.

At present, tomato transplanting in facility agriculture is mainly manual operation. In an attempt to resolve the problems of high labor intensity and low efficiency of manual operation, this paper designs a clip stem automatic transplanting and seedling picking device based on the yolov5 algorithm. First of all, through the study of the characteristics of tomato seedlings of different seedling ages, the age of tomato seedlings suitable for transplanting was obtained. Secondly, the improved yolov5 algorithm was used to determine the position and shape of tomato seedlings. By adding a lightweight upsampling operator (CARAFE) and an improved loss function, the feature extraction ability and detection speed of tomato seedling stems were improved. The accuracy of the improved yolov5 algorithm reached 92.6%, and mAP_0.5 reached 95.4%. Finally, the seedling verification test was carried out with tomato seedlings of about 40 days old. The test results show that the damage rate of the device is 7.2%, and the success rate is not less than 90.3%. This study can provide a reference for research into automatic transplanting machines.

m6A-activated BACH1 exacerbates ferroptosis by epigenetic suppression HSPB1 in severe acute pancreatitis.

Severe acute pancreatitis (SAP) is characterized by acute inflammation of the pancreas. The transcription factor BTB and CNC homology 1 (BACH1) has been implicated in various biological processes, including oxidative stress, apoptosis, and cell cycle regulation. However, its involvement in the pathogenesis of SAP remains relatively understudied. In the present work, our data demonstrated that BACH1 level was significantly increased in SAP patients, cellular, and animal models, while heat shock protein B1 (HSPB1) expression was weakened. Mechanistic assays validated that BACH1 acted as a transcriptional inhibitor of HSPB1. Moreover, HPDE6-C7 cells were stimulated with cerulein (Cer) and LPS to mimic the pathological stages of SAP in vitro. Depletion of BACH1 remarkably improved cell survival and alleviated the oxidative stress, ferroptosis, and inflammatory responses in SAP cell models. However, these changes were dramatically reversed upon co-inhibition of HSPB1. Animal findings confirmed that loss of BACH1 decreased pancreatic injury, inflammatory responses, and ferroptosis, but these effects were weakened by HSPB1 silence. Overall, these findings elucidate that the overexpression of BACH1 favors the ferroptosis and inflammation by transcriptionally inhibiting HSBP1, thereby exacerbating SAP progression.

[2-DG improves lung ischemia/reperfusion injury by inhibiting NLRP3-mediated pyroptosis in rats].

The aim of this study was to investigate whether the protective effect of 2-deoxyglucose (2-DG) on lung ischemia/reperfusion (I/R) injury is mediated by inhibiting nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3)-mediated pyroptosis in rats. Male Sprague-Dawley rats were randomly divided into control group, 2-DG group, lung I/R injury group (I/R group) and 2-DG+I/R group. 2-DG (0.7 g/kg) was intraperitoneally injected 1 h prior to lung ischemia. The tissue structure was measured under light microscope. Lung injury parameters were detected. The contents of malondialdehyde (MDA), myeloperoxidase (MPO) and lactate were determined by commercially available kits. ELISA was used to detect the levels of IL-1ß and IL-18. Western blot, qRT-PCR and immunofluorescence staining were used to measure the expression changes of glycolysis and pyroptosis related indicators. The results showed that there was no significant difference in the parameters between the control group and the 2-DG group. However, the lung injury parameters, oxidative stress response, lactic acid content, IL-1ß, and IL-18 levels were significantly increased in the I/R group. The protein expression levels of glycolysis and pyroptosis related indicators including hexokinase 2 (HK2), pyruvate kinase 2 (PKM2), NLRP3, Gasdermin superfamily member GSDMD-N, cleaved-Caspase1, cleaved-IL-1ß and cleaved-IL-18, and the gene expression levels of HK2, PKM2 and NLRP3 were markedly up-regulated in the I/R group compared with those in the control group. The expression of HK2 and NLRP3 was also increased detected by immunofluorescence staining. Compared with the I/R group, the 2-DG+I/R group exhibited significantly improved alveolar structure and inflammatory infiltration, reduced lung injury parameters, and decreased expression of glycolysis and pyroptosis related indicators. These results suggest that 2-DG protects against lung I/R injury possibly by inhibiting NLRP3-mediated pyroptosis in rats.

[Guidelines for economic evaluation of post-marketing Chinese patent medicine].

With the premise of drug safety and effectiveness, pharmacoeconomic evaluation can provide optimal solutions for diversified decision-making application scenarios from different research perspectives while maximizing the rational utilization of existing healthcare resources. Chinese patent medicine is an essential component of pharmaceutical utilization in China and a significant part of healthcare expenditure in China. However, the economic evaluation of post-marketing Chinese patent medicine is lacking. These evaluations often lack standardization, exhibit varying quality, and are unable to effectively support healthcare decisions, indicating a need for improvement in overall quality. Given this situation, this project has gathered leading experts from China and has strictly adhered to the requirements of the group standards set by the China Association of Traditional Chinese Medicine in developing Guidelines for economic evaluation of post-marketing Chinese patent medicine, aiming to provide methodological guidance for the post-market pharmacoeconomic evaluation of Chinese patent medicine, enhancing the standardization of pharmacoeconomic evaluations of Chinese patent medicine and the scientific validity of research results, and thereby elevating the overall quality of pharmacoeconomic evaluations for post-marketing Chinese patent medicine. The guidelines adhere to the framework provided by relevant laws and regulations in China and technical guidance documents. It is based on guidance from traditional Chinese medicine(TCM) theories, focusing on the unique characteristics of TCM. It covers various aspects of pharmacoeconomic evaluation, including fundamental principles, research topic selection, research question definition, study design type selection, cost identification and measurement, health outcomes, and evaluation methods. The guidelines offer methodological recommendations and decision guidance to address common issues and challenges in the pharmacoeconomic evaluation of post-marketing Chinese patent medicine.

One-Component Cationic Lipids for Systemic mRNA Delivery to Splenic T Cells.

Unlocking the full potential of mRNA immunotherapy necessitates targeted delivery to specific cell subsets in the spleen. Four-component lipid nanoparticles (LNPs) utilized in numerous clinical trials are primarily limited in hepatocyte and muscular targeting, highlighting the imperative demand for targeted and simplified non-liver mRNA delivery systems. Herein, we report the rational design of one-component ionizable cationic lipids to selectively deliver mRNA to the spleen and T cells with high efficacy. Unlike the tertiary amine-based ionizable lipids involved in LNPs, the proposed cationic lipids rich in secondary amines can efficiently deliver mRNA both in vitro and in vivo as the standalone carriers. Furthermore, these vectors facilitate efficacious mRNA delivery to the T cell subsets following intravenous administration, demonstrating substantial potential for advancing immunotherapy applications. This straightforward strategy extends the utility of lipid family for extrahepatic mRNA delivery, offering new insights into vector development beyond LNPs to further the field of precise mRNA therapy.

Peroxidase-Mimicking DNAzymes as Receptors for Label-Free Discriminating Heavy Metal Ions by Chemiluminescence Sensor Arrays.

Receptors are crucial to the analytical performance of sensor arrays. Different from the previous receptors in sensor arrays, herein, peroxidase-mimicking DNAzymes were innovatively used as receptors to develop a label-free chemiluminescence sensor array for discriminating various heavy metal ions in complex samples. The peroxidase-mimicking DNAzymes are composed of functional oligonucleotides and hemin, including G-triplex-hemin DNAzyme (G3-DNAzyme), G-quadruplex-hemin DNAzyme (G4-DNAzyme), and the dimer of G-quadruplex-hemin DNAzyme (dG4-DNAzyme). Circular dichroism (CD) spectroscopy demonstrated that different metal ions diversely affect the conformation of G-quadruplex and G-triplex, resulting in a change in the activity of peroxidase-mimicking DNAzyme. Thus, the unique fingerprints formed to easily discriminate seven kinds of heavy metal ions by principal component analysis (PCA) within 20 min. The discrimination of unknown metal ions in tap water further confirmed its ability for discriminating multiple heavy metal ions. Moreover, it will not bring water pollution due to the good biocompatibility of DNA. Therefore, it not only merely offers a label-free, rapid, environment-friendly, and cheap (1.49 $) sensor assay for discriminating metal ions but also comes up with an innovative way for developing sensor arrays.

Dual-Mode Logic Gate for Intelligent and Portable Detection of MicroRNA Based on Gas Pressure and Lateral Flow Assay.

Molecular logic gate provides an intelligent option for simultaneous detection of biomarkers. Herein, a dual-mode DNA logic gate was proposed to portably and intelligently detect multiple microRNAs (miRNAs) by gas pressure biosensing and lateral flow assay (LFA). A platinum-coated gold nanoparticle (Au@PtNP) with catalase-like activity was used as a signal reporter to achieve a dual-signal readout. MiRNAs as the input initiated the cyclic strand displacement reaction (SDR) to enrich a large amount of Au@PtNPs. Thus, miRNA can be visually detected by a lateral flow strip (LFS) using the grayish-brown color of Au@PtNPs as output 1. Furthermore, Au@PtNP-catalyzed decomposition of H2O2 resulted in gas pressure as output 2, which was measured by a digital and handheld gas pressure meter. As a consequence, microRNA 21 (miR-21) was sensitively and reliably detected with the limit of detection (LOD) of 7.2 pM. The selectivity and real sample analysis were both satisfactory. Significantly, two-input and three-input AND logic gates were successfully developed to realize multiple detection of two miRNAs and three miRNAs, which provide a promising way for intelligent multi-input analysis. Predictably, with the advantages of portability, simplicity, and affordability, the dual-mode logic gate based on gas pressure biosensing and LFA offers a new perspective on the field of intelligent and portable biosensing and bioanalysis.

Logic-Gates of Gas Pressure for Portable, Intelligent and Multiple Analysis of Metal Ions.

DNA logic gates have shown outstanding magic in intelligent biology applications, but it remains challenging to construct a portable, affordable and convenient DNA logic gate. Herein, logic gates of gas pressure were innovatively developed for multiplex analysis of metal ions. Hg2+ and Ag+ were input to interact specifically with the respective mismatched base pairs, which activated DNA extension reaction by polymerase and led to the enrichment of platinum nanoparticles for catalyzing the decomposition of peroxide hydrogen. Thus, the gas pressure obtained from a sealed well was used as output for detecting or identifying metal ions. Hg2+ and Ag+ were sensitively and selectively detected, and the assay of the real samples was also satisfactory. Based on this, DNA logic gates, including YES, NOT, AND, OR, NAND, NOR, INHIBIT, and XOR were successfully established using a portable and hand-held gas pressure meter as detector. So, the interactions between DNA and metal ions were intelligently transferred into the output of gas pressure, which made metal ions to be detected portably and identified intelligently. Given the remarkable merits of simplicity, logic operation, and portable output, the metal ion-driven DNA logic gate of gas pressure provides a promising way for intelligent and portable biosensing.