Liposome-embedded PtCu nanozymes for improved immunoassay of accurate myocardial infarction.

Herein, we developed a platinum-copper nano-enzyme-linked immunosorbent assay (NLISA) based split diagnostic platform for the ultrasensitive detection of cardiac troponin I (cTnI). The PtCu nanozyme synthesized by one-pot synthesis exhibited ultra-high peroxidase-like activity (35.17 U mg-1), which was about 4.5 times higher than that of the unmodified Pt nanozyme (8.83 U mg-1). Due to the efficient peroxidase-like activity of the copper-platinum complexed nanozyme, transduction and sequential amplification of cTnI biological signals were achieved in combination with a liposome-embedded amplification strategy. The encapsulation efficiency was calculated by introducing a liposomal bilayer model, which showed that the introduction of a single liposomal molecule could amplify the signal up to 870-fold, thus promising a high sensitivity test. Notably, the dynamic response of cTnI was in the range of 0.1-5000 pg mL-1 with an ultra-low detection limit (0.048 pg mL-1). The developed NLISA analysis system provides a new way to discover efficient and sensitive alternatives to ELISA kits, which can meet the practical needs of community healthcare testing conditions and rapid testing in hospitals.

Highly selective fluorescence detection of L-selenium-methylselenocysteine in selenium-enriched Cardamine violifolia.

A feasible and practicable "off-on" type of fluorescence strategy for highly selective screening of L-selenium-methylselenocysteine (L-SeMC) in selenium-enriched Cardamine violifolia was developed using g-C3N4-MnO2 nanocomposites as fluorescent probes. The g-C3N4 nanosheets can emit blue fluorescence at 320 nm excitation wavelength with a fluorescence quantum yield of 28%. When MnO2 was deposited onto g-C3N4 nanosheets, the fluorescence of the g-C3N4 nanosheets was quenched due to fluorescence resonance energy transfer (FRET). After the addition of L-SeMC, MnO2 was reduced to Mn2+, which eliminated FRET and fluorescence was restored. Based on this, a quantitative method for the determination of L-SeMC was established. The fluorescence intensity of g-C3N4-MnO2 nanocomposites showed a good linear relationship with the concentration of L-SeMC in the range of 0-45 µg mL-1, the limit of detection (LOD, 3σ/K) was 8.25 ng mL-1 and the correlation coefficient was 0.9904. Common selenium compounds such as SeO2, Na2SeO3, SeMet and SeCys caused weak fluorescence intensity, which means that the developed method is highly selective to detect L-SeMC in a series of selenium compounds. Meanwhile, the technique was evaluated by spiking L-SeMC standards in C. violifolia extraction solutions and with 9 C. violifolia extraction specimens, receiving excellent accordance with results from the commercially available atomic fluorescence spectroscopy method.

Development of a novel fluorescent protein-based probe for efficient detection of Pb2+ in serum inspired by the metalloregulatory protein PbrR691.

BACKGROUND: The accurate and rapid detection of blood lead concentration is of paramount importance for assessing human lead exposure levels. Fluorescent protein-based probes, known for their high detection capabilities and low toxicity, are extensively used in analytical sciences. However, there is currently a shortage of such probes designed for ultrasensitive detection of Pb2+, and no reported probes exist for the quantitative detection of Pb2+ in blood samples. This study aims to fill this critical void by developing and evaluating a novel fluorescent protein-based probe that promises accurate and rapid lead quantification in blood. RESULTS: A simple and small-molecule fluorescent protein-based probe was successfully constructed herein using a peptide PbrBD designed for Pb2+ recognition coupled to a single fluorescent protein, sfGFP. The probe retains a three-coordinate configuration to identify Pb2+ and has a high affinity for it with a Kd' of 1.48 ± 0.05 × 10-17 M. It effectively transfers the conformational changes of the peptide to the chromophore upon Pb2+ binding, leading to fast fluorescence quenching and a sensitive response to Pb2+. The probe offers a broad dynamic response range of approximately 37-fold and a linear detection range from 0.25 nM to 3500 nM. More importantly, the probe can resist interference of metal ions in living organisms, enabling quantitative analysis of Pb2+ in the picomolar to millimolar range in serum samples with a recovery percentage of 96.64%-108.74 %. SIGNIFICANCE: This innovative probe, the first to employ a single fluorescent protein-based probe for ultrasensitive and precise analysis of Pb2+ in animal and human serum, heralds a significant advancement in environmental monitoring and public health surveillance. Furthermore, as a genetically encoded fluorescent probe, this probe also holds potential for the in vivo localization and concentration monitoring of Pb2+.

Response of Phyllosphere and Rhizosphere Microbial Communities to Salt Stress of Tamarix chinensis.

As carriers of direct contact between plants and the atmospheric environment, the microbiomes of phyllosphere microorganisms are increasingly recognized as an important area of study. Salt secretion triggered by salt-secreting halophytes elicits changes in the community structure and functions of phyllosphere microorganisms, and often provides positive feedback to the individual plant/community environment. In this study, the contents of Na+ and K+ in the rhizosphere, plant and phyllosphere of Tamarix chinensis were increased under 200 mmol/L NaCl stress. The increase in electrical conductivity, Na+ and K+ in the phyllosphere not only decreased the diversity of bacterial and fungal communities, but also decreased the relative abundance of Actinobacteriota and Basidiomycota. Influenced by electrical conductivity and Na+, the bacteria-fungus co-occurrence network under salt stress has higher complexity. Changes in the structure of the phyllosphere microbial community further resulted in a significant increase in the relative abundance of the bacterial energy source and fungal pathotrophic groups. The relative abundance of Actinobacteriota and Acidobacteriota in rhizosphere showed a decreasing trend under salt stress, while the complexity of the rhizosphere co-occurrence network was higher than that of the control. In addition, the relative abundances of functional groups of rhizosphere bacteria in the carbon cycle and phosphorus cycle increased significantly under stress, and were significantly correlated with electrical conductivity and Na+. This study investigated the effects of salinity on the structure and physicochemical properties of phyllosphere and rhizosphere microbial communities of halophytes, and highlights the role of phyllosphere microbes as ecological indicators in plant responses to stressful environments.

Portable photoelectrochemical immunoassay with micro-electro-mechanical-system for alpha-fetoprotein in hepatocellular carcinoma.

Early detection of cancer has a profound impact on patient survival and treatment outcomes considering high treatment success rates and reduced treatment complexity. Here, we developed a portable photoelectrochemical (PEC) immune platform for sensitive testing of alpha-fetoprotein (AFP) based on Pt nanocluster (Pt NCs) loaded defective-state g-C3N4 photon-electron transducers. The broad forbidden band structure of g-C3N4 was optimized by the nitrogen doping strategy and additional homogeneous porous structure was introduced to further enhance the photon utilization. In addition, the in-situ growth of Pt NCs provided efficient electron transfer catalytic sites for sacrificial agents, which were used to further improve the sensitivity of the sensor. Efficient photoelectric conversion under a hand-held flashlight was determined by the geometry of the transducer and the energy band design, and the portable design of the PEC sensor was realized. The developed sensing platform exhibited a wide linear response range (0.1-50 ng mL-1) and low limit of detection (0.043 ng mL-1) for AFP under optimum conditions. This work provides a new idea for designing portable PEC biosensing platforms to meet the current mainstream POC testing needs.

Study on the association between adverse drug reactions to opioids and gene polymorphisms: a case-case-control study.

OBJECTIVE: Adverse drug reactions (ADRs) caused by opioid drugs show individual differences. Our objective was to explore the association between gene polymorphism and ADRs induced by opioid drugs. METHODS: Evidence-based medical data analysis was conducted for genes related to ADRs induced by opioid drugs to select target genes. Sixty patients with cancer pain who had ADRs after taking opioid drugs (morphine, codeine, oxycodone) and 60 patients without ADRs after taking opioid drugs were used as the experimental group and control group, respectively. Then, we used polymerase chain reaction (PCR) or in situ hybridization to detect target genes. By combining with clinical data such as age, sex, dosage and duration of medication, the effect of gene polymorphism on the ADR of patients after taking opioid drugs was statistically analysed. RESULTS: Based on a database search and evidence-based medical data, we identified CYP2D6*10, CYP3A5*3, ABCB1, and OPRM1 as target genes for detection. The results of statistical analysis showed no significant difference in genotype distribution between the experimental group and the control group (p > 0.05). However, if 32 patients with ADRs after taking oxycodone and 32 controls were selected for comparison, the SPSS22.0 and SNPStats genetic models showed that the ABCB1 (062rs1045642) CT and TT genotypes correlated with the occurrence of ADRs (p < 0.05): the total number of CT + TT genotypes in the experimental group was 29 (90.62%), with 11 (34.37%) CT + TT genotypes types in the control group. CONCLUSION: Polymorphism of ABCB1 (062rs1045642) is related to ADRs caused by oxycodone, and the incidence of ADRs is higher with the allele T. Polymorphism of ABCB1 is expected to become a clinical predictor of ADRs to oxycodone, and attention should be given to the occurrence of serious ADRs in patients with ABCB1 (062rs1045642) CT and TT genotypes.

Physicochemical Properties of Plasma-Activated Water and Its Control Effects on the Quality of Strawberries.

In this study, the effects of plasma-activated water (PAW), generated by dielectric barrier discharge cold plasma at the gas-liquid interface, on the quality of fresh strawberries during storage were investigated. The results showed that, with the prolongation of plasma treatment time, the pH of PAW declined dramatically and the electrical conductivity increased significantly. The active components, including NO2-, NO3-, H2O2, and O2-, accumulated gradually in PAW, whereas the concentration of O2- decreased gradually with the treatment time after 2 min. No significant changes were found in pH, firmness, color, total soluble solids, malondialdehyde, vitamin C, or antioxidant activity in the PAW-treated strawberries (p > 0.05). Furthermore, the PAW treatment delayed the quality deterioration of strawberries and extended their shelf life. Principal component analysis and hierarchical cluster analysis showed that the PAW 2 treatment group demonstrated the best prolonged freshness effect, with the highest firmness, total soluble solids, vitamin C, and DPPH radical scavenging activity, and the lowest malondialdehyde and ∆E* values, after 4 days of storage. It was concluded that PAW showed great potential for maintaining the quality of fresh fruits and extending their shelf life.

Single-Atom Ruthenium Biomimetic Enzyme for Simultaneous Electrochemical Detection of Dopamine and Uric Acid.

Single-atom catalysts have attracted numerous attention due to the high utilization of metallic atoms, abundant active sites, and highly catalytic activities. Herein, a single-atom ruthenium biomimetic enzyme (Ru-Ala-C3N4) is prepared by dispersing Ru atoms on a carbon nitride support for the simultaneous electrochemical detection of dopamine (DA) and uric acid (UA), which are coexisting important biological molecules involving in many physiological and pathological aspects. The morphology and elemental states of the single-atom Ru catalyst are studied by transmission electron microscopy, energy dispersive X-ray elemental mapping, high-angle annular dark field-scanning transmission electron microscopy, and high-resolution X-ray photoelectron spectroscopy. Results show that Ru atoms atomically disperse throughout the C3N4 support by Ru-N chemical bonds. The electrochemical characterizations indicate that the Ru-Ala-C3N4 biosensor can simultaneously detect the oxidation of DA and UA with a separation of peak potential of 180 mV with high sensitivity and excellent selectivity. The calibration curves for DA and UA range from 0.06 to 490 and 0.5 to 2135 µM with detection limits of 20 and 170 nM, respectively. Moreover, the biosensor was applied to detect DA and UA in real biological serum samples using the standard addition method with satisfactory results.

A Rare Case of the Newly Recognized Kaposi Sarcoma Herpesvirus-Associated Disease.

Kaposi sarcoma herpesvirus (KSHV) is associated with Kaposi sarcoma (KS), primary effusion lymphoma, and multicentric Castleman disease (KSHV-MCD) in patients infected with human immunodeficiency virus (HIV). We present a case consistent with a newly recognized KSHV inflammatory cytokine syndrome (KICS), distinct from KSHV-MCD. Although both disorders exhibit signs of substantial inflammation, KICS has minimal lymphadenopathy/splenomegaly and negative pathologic nodal changes in the setting of low CD4 count. KICS is easily misdiagnosed as severe sepsis or other KS-related diseases in HIV/AIDS patients and carries a high mortality. ​Standard therapy is still under investigation due to its rarity, whereas the treatment regimen for KSHV-MCD may lead to clinical remission. Early recognition and prompt management are crucial to improve the survival of the under-recognized KICS.

Inequalities for the fractional convolution operator on differential forms.

The purpose of this paper is to derive some Coifman type inequalities for the fractional convolution operator applied to differential forms. The Lipschitz norm and BMO norm estimates for this integral type operator acting on differential forms are also obtained.

Asn563Ser polymorphism of CD31/PECAM-1 is associated with atherosclerotic cerebral infarction in a southern Han population.

BACKGROUND: CD31, also called platelet endothelial cell adhesion molecule-1 (PECAM-1), is thought to play a role in the pathological mechanisms of atherosclerosis. Leu125Val polymorphism and elevated plasma levels of soluble PECAM-1 (sPECAM-1) were found to be associated with cerebral infarction. Our aim was to investigate the association between the Asn563Ser polymorphism of CD31/PECAM-1, plasma level of sPECAM-1, and the risk of atherosclerotic cerebral infarction (ACI) in the southern Han population of the People's Republic of China. SUBJECTS AND METHODS: A total of 147 subjects with ACI and 114 controls were enrolled in the study. The Asn563Ser CD31/PECAM-1 polymorphism was detected using the polymerase chain reaction-restriction fragment length polymorphism method. The plasma spECAM-1 level was measured using the enzyme-linked immunosorbent assay method. RESULTS: In this study, statistically significant differences in Asn563Ser genotype and allele distribution were found between the cases and controls (P<0.05). Furthermore, logistic regression analysis showed that the GG genotype is associated with increase in ACI risk (odds ratio =4.862, P<0.001). The plasma level of sPECAM-1 was associated with ACI (odds ratio =1.431, P=0.038). In both the ACI and the control groups, the plasma sPECAM-1 level in subjects with the GG genotype was higher than that in subjects carrying the AA or GA genotype (P<0.05). CONCLUSION: Our study showed that the Asn563Ser polymorphism of CD31/PECAM-1 gene and elevated plasma sPECAM-1 level are related to ACI risk in the southern Han population of People's Republic of China.

Cerium oxide-triggered 'one-to-many' catalytic cycling strategy for in situ amplified electronic signal of low-abundance protein.

Multifunctionalized thionine-modified cerium oxide (Thi-CeO2) nanostructures with redox ability and catalytic activity were designed as the bionanolabels for in situ amplified electronic signal of low-abundance protein (carcinoembryonic antigen, CEA, used as a model) based on a cerium oxide-triggered 'one-to-many' catalytic cycling strategy. Initially, the carried CeO2 nanoparticles autocatalytically hydrolyzed the phosphate ester bond of l-ascorbic acid 2-phosphate (AAP) to produce a new reactant (l-ascorbic acid, AA), then the generated AA was electrochemically oxidized by the assembled thionine on the Thi-CeO2, and the resultant product was then reduced back to AA by the added tris(2-carboxyethy)phosphine (TCEP). The catalytic cycling could be re-triggered by the thionine and TCEP, resulting in amplification of the electrochemical signal. Under the optimized conditions, the electrochemical immunosensor exhibited a wide linear range of 0.1 pg mL(-1) to 80 ng mL(-1) with a low detection limit of 0.08 pg mL(-1) CEA at the 3σblank level. In addition, the methodology was evaluated for the analysis of clinical serum samples, and was in good accordance with values obtained using the commercialized enzyme-linked immunosorbent assay (ELISA) method.

In situ amplified electronic signal for determination of low-abundance proteins coupling with nanocatalyst-based redox cycling.

Platinum-cerium oxide hybrid nanocatalysts (CeO(2)-Pt) were for the first time designed as bionanolabels for highly efficient electrochemical immunosensing of low-abundance proteins coupling nanocatalyst-based redox cycling with in situ signal amplification strategy.

Dual-nanogold-linked bio-barcodes with superstructures for in situ amplified electronic detection of low-abundance proteins.

A novel and nonenzyme immunosensing protocol is proposed for ultrahighly sensitive detection of low-abundance-proteins (carcinoembryonic antigen as a model) using dual nanogold-linked complementary bio-barcodes with superstructures for in situ amplified electronic signals.

Epigenetic silencing of IRF7 and/or IRF5 in lung cancer cells leads to increased sensitivity to oncolytic viruses.

Defective IFN signaling results in loss of innate immunity and sensitizes cells to enhanced cytolytic killing after Vesticular Stomatitis Virus (VSV) infection. Examination of the innate immunity status of normal human bronchial epithelial cells Beas2B and 7 lung cancer cells revealed that the abrogation of IFN signaling in cancer cells is associated with greater sensitivity to VSV infection. The disruption of the IFN pathway in lung cancer cell lines and primary tumor tissues is caused by epigenetic silencing of critical interferon responsive transcription factors IRF7 and/or IRF5. Although 5-aza-2'-deoxycytidine treatment fails to reactivate IRF7 and IRF5 expression or protect cells from VSV infection, manipulating IFN signaling by altering IRF expression changes the viral susceptibility of these cells. Lung cancer cells can be partially protected from viral killing using IRF5+IRF7 overexpression, whereas IFN pathway disruption by transfection of siRNAs to IRF5+IRF7 increases cells' vulnerability to viral infection. Therefore, IRF5 and IRF7 are key transcription factors in IFN pathway that determine viral sensitivity of lung cancer cells; the epigenetically impaired IFN pathway in lung cancer tissues provides potential biomarkers for successful selective killing of cancer cells by oncolytic viral therapy.

YKL-40 expression in human hepatocellular carcinoma: a potential biomarker?

BACKGROUND: YKL-40 is a new biomarker with diagnostic value in many different cancers. Whether it may serve as a biomarker for hepatocellular carcinoma (HCC) is still unclear. This study aimed to examine the expression of YKL-40 in the serum and liver tissues of HCC patients and in HCC cell lines, in comparison with that in non-HCC liver disease patients and non-tumor hepatic cell lines, respectively. METHODS: Immunohistochemical staining was used to detect YKL-40 protein expression in liver biopsy specimens from 8 HCC patients. ELISA was used to assess the serum YKL-40 level in 90 HCC patients, 90 inactive HBsAg carrier (IHC) patients with normal liver functions, and 90 liver cirrhosis patients. Real-time PCR was used to determine the YKL-40 mRNA expression in three HCC cell lines and two non-tumor hepatic cell lines. RESULTS: Immunohistochemical staining of liver biopsy specimens from HCC patients showed that the YKL-40 protein expression in tumor tissue was higher than that in adjacent normal tissues. ELISA revealed that the YKL-40 serum level in the HCC group was significantly higher than that in the IHC group, but not significantly different from that in the cirrhosis group. Real-time PCR showed that YKL-40 mRNA levels in HCC cell lines were significantly higher than those in non-tumor hepatic cells. CONCLUSIONS: YKL-40 is highly expressed in HCC at the molecular, cellular and tissue levels. However, it may not serve as a serum biomarker for HCC because measurement of the serum YKL-40 level cannot distinguish HCC from cirrhosis.

Ultrasensitive aptamer-based multiplexed electrochemical detection by coupling distinguishable signal tags with catalytic recycling of DNase I.

This work reports an aptamer-based, disposable, and multiplexed sensing platform for simultaneous electrochemical determination of small molecules, employing adenosine triphosphate (ATP) and cocaine as the model target analytes. The multiplexed sensing strategy is based on target-induced release of distinguishable redox tag-conjugated aptamers from a magnetic graphene platform. The electronic signal of the aptasensors could be further amplified by coupling DNase I with catalytic recycling of self-produced reactants. The assay was based on the change in the current at the various peak potentials in the presence of the corresponding signal tags. Experimental results revealed that the multiplexed electrochemical aptasensor enabled the simultaneous monitoring of ATP and cocaine in a single run with wide working ranges and low detection limits (LODs: 0.1 pM for ATP and 1.5 pM for cocaine). This concept offers promise for rapid, simple, and cost-effective analysis of biological samples.

Specific immunoreaction-induced controlled release strategy for sensitive impedance immunoassay of a cancer marker.

A simple and facile impedance immunoassay strategy for sensitive detection of alpha-fetoprotein (AFP), as a model cancer marker, was developed by using target-induced release of nanogold particle-labelled anti-AFP antibodies from polyvinylpyrrolidone-coated magnetic carbon nanotubes.

Magneto-controlled electrochemical immunosensor for direct detection of squamous cell carcinoma antigen by using serum as supporting electrolyte.

A new magneto-controlled microfluidic device for direct electrochemical determination of squamous cell carcinoma antigen (SCC-Ag) in serum was designed by using anti-SCC antibody (SCC-Ab)-functionalized magnetic mesoporous nanogold/thionine/NiCo(2)O(4) hybrid nanostructures as immunosensing probes (P(1)-Ab) and horseradish peroxidase-SCC-Ab conjugates-labeled nanogold/graphene nanosheets as signal tags (P(2)-Ab). In the presence of the analyte SCC-Ag, the sandwich immunocomplex was formed between the immunosensing probes and the signal tags. With the aid of an external magnet, the formed immunocomplex was attached to the microfluidic device. The assay was implemented in newborn calf serum (NBCS) containing 2.5 mM H(2)O(2) based on the labeled peroxidase on the P(2)-Ab toward the catalytic reduction of H(2)O(2). Under optimal conditions, the increase in the current was proportional to the concentration of SCC-Ag from 2.5 pg/mL to 15 ng/mL. The detection limit (LOD) was 1.0 pg/mL SCC-Ag at 3s(B). The electrochemical immunoassay displayed an acceptable precision, selectivity and stability. Clinical serum specimens were assayed with the method, and the results were in acceptable agreement with those obtained from the referenced electrochemiluminescent method. Importantly, the method can be suitable for on-line use in the mass production of miniaturized lab-on-a-chip devices and open a new opportunity for protein diagnostics and biosecurity.