Effect of Individualized PEEP Guided by Driving Pressure on Diaphragm Function in Patients Undergoing Laparoscopic Radical Resection of Colorectal Cancer: A Randomized Controlled Trial.

BACKGROUND The concept of driving pressure (ΔP) has been established to optimize mechanical ventilation-induced lung injury. However, little is known about the specific effects of setting individualized positive end-expiratory pressure (PEEP) with driving pressure guidance on patient diaphragm function. MATERIAL AND METHODS Ninety patients were randomized into 3 groups, with PEEP set to 0 in group C; 5 cmH2O in group F; and individualized PEEP in group I, based on esophageal manometry. Diaphragm ultrasound was performed in the supine position at 6 consecutive time points from T0-T5: diaphragm excursion, end-expiratory diaphragm thickness (Tdi-ee), and diaphragm thickening fraction (DTF) were measured. Primary indicators included diaphragm excursion, Tdi-ee, and DTF at T0-T5, and the correlation between postoperative DTF and ΔP. Secondary indicators included respiratory mechanics, hemodynamic changes at intraoperative d0-d4 time points, and postoperative clinical pulmonary infection scores. RESULTS (1) Diaphragm function parameters reached the lowest point at T1 in all groups (P<0.001). (2) Compared with group C, diaphragm excursion decreased, Tdi-ee increased, and DTF was lower in groups I and F at T1-T5, with significant differences (P<0.05), but the differences between groups I and F were not significant (P>0.05). (3) DTF was significantly and positively correlated with mean intraoperative ΔP in each group at T3, and the correlation was stronger at higher levels of ΔP. CONCLUSIONS Individualized PEEP, achieved by esophageal manometry, minimizes diaphragmatic injury caused by mechanical ventilation based on lung protection, but its protection of the diaphragm during laparoscopic surgery is not superior to that of conventional ventilation strategies.

Study on Anti-Constipation Effects of Hemerocallis citrina Baroni through a Novel Strategy of Network Pharmacology Screening.

Daylily (Hemerocallis citrina Baroni) is an edible plant widely distributed worldwide, especially in Asia. It has traditionally been considered a potential anti-constipation vegetable. This study aimed to investigate the anti-constipation effects of daylily from the perspective of gastro-intestinal transit, defecation parameters, short-chain organic acids, gut microbiome, transcriptomes and network pharmacology. The results show that dried daylily (DHC) intake accelerated the defecation frequency of mice, while it did not significantly alter the levels of short-chain organic acids in the cecum. The 16S rRNA sequencing showed that DHC elevated the abundance of Akkermansia, Bifidobacterium and Flavonifractor, while it reduced the level of pathogens (such as Helicobacter and Vibrio). Furthermore, a transcriptomics analysis revealed 736 differentially expressed genes (DEGs) after DHC treatment, which are mainly enriched in the olfactory transduction pathway. The integration of transcriptomes and network pharmacology revealed seven overlapping targets (Alb, Drd2, Igf2, Pon1, Tshr, Mc2r and Nalcn). A qPCR analysis further showed that DHC reduced the expression of Alb, Pon1 and Cnr1 in the colon of constipated mice. Our findings provide a novel insight into the anti-constipation effects of DHC.

Nanobodies for Accurate Recognition of Iso-tenuazonic Acid and Development of Sensitive Immunoassay for Contaminant Detection in Foods.

The accurate analysis of chemical isomers plays an important role in the study of their different toxic effects and targeted detection of pollutant isomers in foods. The Alternaria mycotoxins tenuazonic acid (TeA) and iso-tenuazonic acid (ITeA) are two isomer mycotoxins with the lack of single analysis methods due to the similar structures. Antibody-based immunoassays exhibit high sensitivity and superior application in isomer-specific determination. Previously, various kinds of antibodies for TeA have been prepared in our group. Herein, highly specific nanobodies (Nbs) against ITeA mycotoxin were selected from immune nanobody phage display library, and one of Nbs, namely Nb(B3G3) exhibited excellent affinity, thermal stability as well as organic solvent tolerance. By molecular simulation and docking technology, it was found that stronger interaction between Nb(B3G3) and ITeA lead to higher affinity than that for its isomer TeA. Furthermore, a sensitive indirect competitive enzyme-linked immunosorbent assay (icELISA) was established with a limit of detection (LOD) of 0.09 ng/mL for ITeA mycotoxin. The recovery rate of ITeA in spiked samples was analyzed with 84.8%-89.5% for rice, 78.3%-96.3% for flour, and 79.5%-90.7% for bread. A conventional LC-MS/MS method was used to evaluate the accuracy of this proposed icELISA, which showed a satisfactory consistent correlation. Since the convenient strategy for nanobody generation by phage display technology, this study provide new biorecognition elements and sensitive immunoassay for analysis of ITeA in foods.

The Anti-Constipation Effects of Raffino-Oligosaccharide on Gut Function in Mice Using Neurotransmitter Analyses, 16S rRNA Sequencing and Targeted Screening.

Raffino-oligosaccharide (ROS), the smallest oligosaccharide of the raffinose family, is a novel food ingredient. However, the anti-constipation effects of ROS remain obscure. This study investigates the anti-constipation effects of ROS based on the loperamide-induced mice model and reveals the underlying mechanism using constipation parameters, neurotransmitter level, 16S rRNA sequencing, and the targeted screening strategy. The prevention effects were firstly investigated by the gastro-intestinal transit rate experiment (50 mice) and defecation status experiment (50 mice), which were divided into five groups (n = 10/group): blank, model, and low-, medium- and high-dose ROS. Furthermore, the slow-transit constipation experiment (blank, model, and high-dose ROS, n = 10/group) was conducted to illustrate the underlying mechanism. The results showed that ROS aided in preventing the occurrence of constipation by improving the gastro-intestinal transit rate and the defecation frequency in mice, and ROS significantly reduced the serum levels of vasoactive intestinal peptide (VIP). In addition, ROS regulated the diversity and structure of intestinal flora. Among them, one specific family and six specific genera were significantly regulated in constipated mice. The targeted screening revealed that 29 targets related to the anti-constipation effects of ROS, indicating ROS may play a role by regulating multiple targets. Furthermore, the network pharmacology analysis showed that Akt1, Stat3, Mapk8, Hsp90aa1, Cat, Alb, Icam1, Sod2, and Gsk3b can be regarded as the core anti-constipation targets. In conclusion, ROS could effectively relieve constipation, possibly by inhibiting the level of neurotransmitters and regulating the gut flora in mice. This study also provides a novel network pharmacology-based targeted screening strategy to reveal the anti-constipation effects of ROS.

Multiplex optical bioassays for food safety analysis: Toward on-site detection.

Food safety analysis plays a significant role in controlling food contamination and supervision. In recent years, multiplex optical bioassays (MOBAs) have been widely applied to analyze multiple hazards due to their efficiency and low cost. However, due to the challenges such as multiplexing capacity, poor sensitivity, and bulky instrumentation, the further application of traditional MOBAs in food screening has been limited. In this review, effective strategies regarding food safety MOBAs are summarized, such as spatial-resolution modes performed in multi-T lines/dots strips or arrays of strip/microplate/microfluidic chip/SPR chip and signal-resolution modes employing distinguishable colorimetric/luminescence/fluorescence/surface plasma resonance/surface-enhanced Raman spectrum as signal tags. Following this, new trends on how to design engineered sensor architecture and exploit distinguishable signal reporters, how to improve both multiplexing capacity and sensitivity, and how to integrate these formats into smartphones so as to be mobile are summarized systematically. Typically, in the case of enhancing multiplexing capacity and detection throughput, microfluidic array chips with multichannel architecture would be a favorable approach to overcome the spatial and physical limitations of immunochromatographic assay (ICA) test strips. Moreover, noble metal nanoparticles and single-excitation, multiple-emission luminescence nanomaterials hold great potential in developing ultrasensitive MOBAs. Finally, the exploitation of innovative multiplexing strategy hybridized with powerful and widely available smartphones opens new perspectives to MOBAs. In future, the MOBAs should be more sensitive, have higher multiplexing capacity, and easier instrumentation.

The Most Active Oxidase-Mimicking Mn2 O3 Nanozyme for Biosensor Signal Generation.

Oxidase-mimicking nanozymes are more desirable than peroxidase-mimicking ones since H2 O2 can be omitted. However, only a few nanomaterials are known for oxidase-like activities. In this work, we compared the activity of Mn2 O3 , Mn3 O4 and MnO2 and found that Mn2 O3 had the highest oxidase activity. Interestingly, the activity of Mn2 O3 was even inhibited by H2 O2 . The oxidase-like activity of Mn2 O3 was not much affected by the presence of proteins such as bovine serum albumin (BSA), but the physisorption of antibodies to Mn2 O3 was not strong enough to withstand the displacement by BSA. We then treated Mn2 O3 with 3-aminopropyltriethoxysilane to graft an amine group, which was used to conjugate antibodies using glutaraldehyde as a crosslinker. A one-step indirect competitive ELISA (icELISA) was developed for the detection of isocarbophos, and an IC50 of 261.7 ng/mL was obtained, comparable with the results of the standard two-step assay using horseradish peroxidase (HRP)-labeled antibodies. This assay has the advantage of significant timesaving for rapid detection of large amounts of samples. This work has discovered a highly efficient oxidase-mimicking nanozyme useful for various nano- and analytical applications.

Effect of proteins on the oxidase-like activity of CeO2 nanozymes for immunoassays.

Having the benefits of low cost, excellent stability and tolerance to extreme conditions, nanozymes are a potential alternative of horseradish peroxidase (HRP) or other enzymes for bioanalytical chemistry, especially immunoassays. CeO2 nanoparticles have oxidase-mimicking activity and can avoid the use of unstable H2O2. For robust assays, the effect of proteins on the activity of CeO2 needs to be carefully studied. Herein, we studied the adsorption and desorption of bovine serum albumin (BSA) from CeO2. The CeO2 nanoparticles exhibited a higher protein adsorption capacity compared to the other tested metal oxide nanoparticles. Although the oxidase-like activity of CeO2 was inhibited by BSA, low concentrations of phosphate and fluoride ions boosted the activity of protein-capped CeO2. CeO2 was still active under strong acidic conditions and at high temperature, while HRP lost its activity. For immunoassay development, we covered CeO2 with an amine-modified silane for covalent conjugation to antibodies. A one-step indirect competitive ELISA for fenitrothion was developed, and an IC50 value of 35.6 ng mL-1 and a limit of detection of 2.1 ng mL-1 were obtained.

Open Surface Droplet Microfluidic Magnetosensor for Microcystin-LR Monitoring in Reservoir.

Establishing rapid, simple, and in situ detection of microcystin-LR (MC-LR) in drinking water sources is of significant importance for human health. To ease the situation that current methods cannot address, an open surface droplet microfluidic magnetosensor was designed and validated to quantify MC-LR in reservoir water, which is capable of (1) MC-LR isolation via MC-LR antibody-conjugated magnetic beads, (2) parallel and multistep analytical procedures in 15-array power-free and reusable active droplet microfluidic chips, (3) immunoassay incubation and fluorescence excitation within a miniaturized multifunctional 3D-printing optosensing accessory, and (4) signal read-out and data analysis by a user-friendly Android app. The proposed smartphone-based fluorimetric magnetosensor exhibited a low limit of detection of 1.2 × 10-5 µg/L in the range of 10-4 µg/L to 100 µg/L. This integrated and high throughput platform was utilized to draw an MC-LR contamination map for six reservoirs distributed in the Pearl River delta, Guangdong Province. It promises to be a simple and successful quantification method for MC-LR field detection, bringing many benefits to rapid on-site screening.

Visual upconversion nanoparticle-based immunochromatographic assay for the semi-quantitative detection of sibutramine.

Immunochromatographic assay (ICA) has been used widely for the onsite monitoring of illegal additives due to its simplicity, speed, and low cost. However, a scanner is commonly required for ICA to achieve quantitative results. In this work, we developed a visual semi-quantitative ICA for sibutramine, a banned additive in diet foods, without the need for a scanner for measurement. Monoclonal antibodies specific for sibutramine were raised and conjugated with upconversion nanoparticles (UCNPs) as the luminescent tracer. ICA was developed by employing multiple test lines to achieve the semi-quantitative detection of sibutramine. Based on the optimal conditions, the cutoff levels (limit of quantitation, LOQ) of T1 line, T2 line, T3 line, and T4 line were 0.02 µg/mL, 0.15 µg/mL, 1.0 µg/mL, and 7.5 µg/mL, respectively, in buffer system. The ICA demonstrated a LOQ at 0.2 mg/kg for sibutramine in diet food samples. The assay (including pretreatment) can be finished within 30 min without the aid of other instruments, except a laser pen. No false positive or false negative results were observed. The results indicated that the proposed method was reliable, simple, and rapid for the screening of sibutramine abuse in diet food samples.

Protective effect of hawthorn extract against genotoxicity induced by benzo()pyrene in C57BL/6 mice.

Benzo()pyrene [B()P], widely originated from environmental pollution or food process such as roasting and frying, is a strong mutagen and potent carcinogen. Utilization of hawthorn has been reported against physical mutagens. Our study found that hawthorn extract (HE) contained abundant phenolic compounds, wherein chlorogenic acid was 2.78 mg/g, procyanidine B2 was 3.58 mg/g, epicatechin was 2.99 mg/g DW, which may contribute to anti-genotoxicity activity. So, the role of HE against B()P-induced genotoxicity in C57BL/6 mice was further assessed. Fifty mice were distributed into five groups: control group, B()P group (30 mg/kg, i.p.), B()P + HE-L group (100 mg/kg, i.g.), B()P + HE-M group (200 mg/kg, i.g.), B()P + HE-H group (400 mg/kg, i.g.). Mice were orally administered with solutions of HE for 10 days and injected intraperitoneally with B()P for 3 days from the 8th day. Results showed that B()P can induce significantly pathological damage in liver, lung and spleen, as well as decrease white blood cells (WBCs). Remarkably elevated levels of reactive oxygen species (ROS), DNA strand breaks (DSBs) and G1 cell cycle arrest were also found in B()P group, with upregulated expressions of p-H2AX, p-p53 and p21 in bone marrow cells. With administration of HE, liver, lung and spleen injury significantly mitigated, while WBCs were evidently increased in B()P-treated mice. Consistently, HE markedly reduced level of ROS, DSBs and G1 cell cycle arrest accompanied by reducing expressions of p-H2AX, p-p53 and p21 in bone marrow cells. Combined, these results indicated a protective role of HE on B()P-induced genotoxicity.

A rapid and simple fluorescence enzyme-linked immunosorbent assay for tetrabromobisphenol A in soil samples based on a bifunctional fusion protein.

Tetrabromobisphenol A (TBBPA) is the largest brominated flame retardant which can be released to environment and cause long-term hazard. In this work, we developed a rapid and highly sensitive fluorescence enzyme-linked immunosorbent assay (FELISA) for monitoring of TBBPA in soil samples. TBBPA specific nanobody derived from camelid was fused with alkaline phosphatase to obtain the bi-functional fusion protein, which enable the specific binding of TBBPA and the generation of detection signal simultaneously. The assay showed an IC50 of 0.23 ng g-1, limit detection of 0.05 ng g-1 and linear range from 0.1 to 0.55 ng g-1 for TBBPA in soil samples. Due to the high resistance to organic solvents of the fusion protein, a simple pre-treatment by using 40% dimethyl sulfoxide (DMSO) as extract solvent can eliminate matrix effect and obtain good recoveries (ranging from 93.4% to 112.4%) for spiked soil samples. Good relationship between the results of the proposed FELISA and that of liquid chromatography tandem mass spectrometry (LC-MS/MS) was obtained, which indicated it could be a powerful analytical tool for determination of TBBPA to monitor human and environmental exposure.

Semiquantitative immunochromatographic colorimetric biosensor for the detection of dexamethasone based on up-conversion fluorescent nanoparticles.

A low-cost bifunctional immunochromatographic colorimetric biosensor was developed that can be read visually or by using an optical density scanner. Five test lines (T lines) coated with different antigens were set on a nitrocellulose (NC) membrane to indicate the concentration of analyte. This method was applied for the detection of dexamethasone. The corresponding detection range was 0.1-9 ng mL-1, and the detection limit for dexamethasone in food supplements and cosmetic samples was 2.0 µg kg-1. For visual inspection of the colour the quantitative relative error range between the proposed method and liquid chromatography was -62 to -25%, with a detection time of only 10 min. More accurate assay results were obtained by using an optical density scanner with the relative error range of -31 to 20%. The results indicated that the proposed method has the potential of application for rapid and efficient screening of dexamethasone in cosmetics and food supplements. Graphical abstract.

Carbogenic Nanozyme with Ultrahigh Reactive Nitrogen Species Selectivity for Traumatic Brain Injury.

Reactive oxygen and nitrogen species (RONS), especially reactive nitrogen species (RNS) are intermediate products during incidence of nervous system diseases, showing continuous damage for traumatic brain injury (TBI). Here, we developed a carbogenic nanozyme, which shows an antioxidant activity 12 times higher than ascorbic acid (AA) and behaves as multienzyme mimetics. Importantly, the nanozyme exhibits an ultrahigh scavenging efficiency (∼16 times higher than AA) toward highly active RNS, such as •NO and ONOO- as well as traditional reactive oxygen species (ROS) including O2•-, H2O2, and •OH. In vitro experiments show that neuron cells injured by H2O2 or lipopolysaccharide can be significantly recovered after carbogenic nanozyme treatment via scavenging all kinds of RONS. Moreover, the carbogenic nanozyme can serve as various enzyme mimetics and eliminate the harmful peroxide and glutathione disulfide from injured mice, demonstrating its potential as a therapeutic for acute TBI.

Yunnan Baiyao reduces hospital-acquired pressure ulcers via suppressing virulence gene expression and biofilm formation of Staphylococcus aureus.

Yunnan Baiyao (YB) as a kind of famous Chinese herbal medicine, possessed hemostatic, invigorating the circulation of blood, and anti-inflammatory effects. Identifying strategies to protect patients at risk for hospital-acquired pressure ulcers (HAPU) is essential. Herein, our results showed that YB treatment can effectively reduce the acne wound area and improve efficacy in a comparative study of 60 cases HAPU patients with S. aureus positive of acne wound pathogens. Furthermore, YB inhibited HIa expression and suppressed accessory gene regulator (agr) system controlled by regulatory RNA II and RNA III molecule using pALC1740, pALC1742 and pALC1743 S. aureus strain linked to gfpuvr reporter gene. Moreover, YB downregulated cao mRNA expression and inhibited coagulase activity by RT-PCR, slide and tube coagulase test. Additionally, YB downregulated seb, sec, sed, and tsst-1 mRNA expression to suppress enterotoxin and tsst-1 secretion and adhesion function related genes sarA, icaA, and cidA mRNA expression. Taken together, the data suggest that YB may reduce HAPU via suppressing virulence gene expression and biofilm formation of S. aureus.

The Constipation-Relieving Property of d-Tagatose by Modulating the Composition of Gut Microbiota.

d-tagatose, a monosaccharide as well as a dietary supplement, has been reported as having a wide range of applicability in the food industry, however, the prebiotic activity, anticonstipation effects, and related mechanisms are still unclear. In this study, using the loperamide-induced constipation Kunming mice as the animal model, the effects of d-tagatose for the prevention of constipation were evaluated by gastrointestinal transit experiment and defecation experiment. Furthermore, the underlying mechanism was clarified by evaluating the change of the biochemical indicators and analyzing 16S rRNA amplicon of gut microbiota among the different mice groups. The results showed that the gastrointestinal transit rate, fecal number, and weight in six hours were significantly enhanced after the administration of d-tagatose. In addition, d-tagatose significantly increased the serum levels of acetylcholine (Ach) and substance P (SP), whereas the serum levels of nitric oxide (NO) were significantly decreased. Moreover, the 16S rRNA sequencing analysis revealed that the changes in the gut microbiota caused by constipation were restored by d-tagatose treatment. In conclusion, this study indicated that the administration of d-tagatose as a dietary supplement can effectively prevent and relieve constipation in Kunming mice, and it is a promising prebiotic candidate with constipation-relieving properties.

Formation of Ethyl Carbamate during the Production Process of Cantonese Soy Sauce.

The aim of this work was to clarify the formation of ethyl carbamate (EC) and its influence factors throughout the production process of Cantonese soy sauce. The results showed that EC was not detected in the koji-making and early moromi fermentation stages, but started to be generated when pH of the moromi decreased to about 4.9-at the same time, the levels of ethanol, urea and citrulline increased significantly. Most EC was formed during raw soy sauce hot extraction (40.6%) and sterilization (42.9%) stages. The EC content exhibited the highest correlation with ethanol throughout the whole production process (R = 0.97). The simulation soy sauce produced in laboratory led the same conclusion-moreover, the contents of EC, ethanol and citrulline were higher in soy sauce fermented at 30 °C than in soy sauce fermented at 15 °C. Extraction of raw soy sauce by squeezing contributed little to EC formation. Further research showed that citrulline and ethanol led to significant increases in EC levels in raw soy sauce upon heating. These results indicate that ethanol and citrulline are two critical precursors of EC and that EC is mainly formed during the heat treatment stage of soy sauce.

Fluorescence Polarization Immunoassay for Determination of Enrofloxacin in Pork Liver and Chicken.

Enrofloxacin (ENR) is a widely used fluoroquinolone (FQ) antibiotic for antibacterial treatment of edible animal. In this study, a rapid and highly specific fluorescence polarization immunoassay (FPIA) was developed for monitoring ENR residues in animal foods. First, ENR was covalently coupled to bovine serum albumin (BSA) to produce specific polyclonal antibodies (pAbs). Three fluorescein-labeled ENR tracers (A, B, and C) with different spacers were synthesized and compared to obtain higher sensitivity. Tracer C with the longest arm showed the best sensitivity among the three tracers. The developed FPIA method showed an IC50 (50% inhibitory concentration) of 21.49 ng·mL-1 with a dynamic working range (IC20-IC80) of 4.30-107.46 ng·mL-1 and a limit of detection (LOD, IC10) of 1.68 ng·mL-1. The cross-reactivity (CR) of several structurally related compounds was less than 2%. The recoveries of spiked pork liver and chicken samples varied from 91.3% to 112.9%, and the average coefficients of variation were less than 3.83% and 5.13%, respectively. The immunoassay took only 8 min excluding sample pretreatment. This indicated that the established method had high sensitivity, specificity, and the advantages of simplicity. Therefore, the proposed FPIA provided a useful screening method for the rapid detection of ENR residues in pork liver and chicken.

Four Hapten Spacer Sites Modulating Class Specificity: Nondirectional Multianalyte Immunoassay for 31 ß-Agonists and Analogues.

Immunoassay methods are important for monitoring ß-agonists illegally used for reducing animal fat deposition in livestock. However, there is no simultaneous screening surveillance immunoassay for detecting various ß-agonist chemicals that are possibly present in food. In this study, through the use of an R-(-)-salbutamol derivative as the immunizing hapten, an antibody recognizing 31 ß-agonists and analogues was generated for the first time. Three-dimensional quantitative structure-activity relationship (3D QSAR) revealed that strong steric and hydrophobic fields around the hapten spacer near C-2, as well as a chirality at C-1', dominantly modulated the class specificity of the raised antibody. However, a hapten spacer linked at C-2' or C-1 would lead to a narrow specificity, and the spacer charge at C-6 could affect the raised antibody specificity spectrum. A class specificity competitive indirect enzyme-linked immunosorbent assay (ciELISA) was established with an ideal recovery ranging from 81.8 to 118.3% based on the obtained antibody. With a good agreement to the HPLC/MS method, the proposed ciELISA was confirmed to be reliable for the rapid surveillance screening assay of ß-agonists in urine. This investigation will contribute to the rational design and control of the immunoassay specificity.

Isolation of Bactrian Camel Single Domain Antibody for Parathion and Development of One-Step dc-FEIA Method Using VHH-Alkaline Phosphatase Fusion Protein.

A heavy chain variable fragment of heavy chain only antibodies derived from camelids termed VHH shows beneficial characteristics for immunoassay in terms of high sensitivity, outstanding stability and ease in expression. In the present study, we isolated six VHHs from phage display library against parathion, which is a widely used organophosphorus pesticide with high toxicity and persistence. One of six selected VHHs named VHH9, showed highest specificity and superior thermo-stability. A VHH9-alkaline phosphatase (AP) fusion was constructed and used to establish a one-step direct competitive fluorescence enzyme immunoassay (dc-FEIA) with a half maximal inhibitory concentration (IC50) of 1.6 ng/mL and a limit of detection of 0.2 ng/mL which was 4-fold or 3-fold higher sensitivity than direct competitive enzyme-linked immunoassay (dc-ELISA) and indirect competitive enzyme-linked immunoassay (ic-ELISA) for parathion. Furthermore, our assay indicated a 50% reduction on operation time compared with the ic-ELISA method. The presented immunoassay was validated with spiked Chinese cabbage, cucumber, and lettuce samples, and confirmed by UPLC-MS/MS. The results indicated that the VHH-AP-based dc-FEIA is a reproducible detection assay for parathion residues in vegetable samples.

Hollow PtPdRh Nanocubes with Enhanced Catalytic Activities for In Vivo Clearance of Radiation-Induced ROS via Surface-Mediated Bond Breaking.

Catalytic nanomaterials can be used extrinsically to combat diseases associated with a surplus of reactive oxygen species (ROS). Rational design of surface morphologies and appropriate doping can substantially improve the catalytic performances. In this work, a class of hollow polyvinyl pyrrolidone-protected PtPdRh nanocubes with enhanced catalytic activities for in vivo free radical scavenging is proposed. Compared with Pt and PtPd counterparts, ternary PtPdRh nanocubes show remarkable catalytic properties of decomposing H2 O2 via enhanced oxygen reduction reactions. Density functional theory calculation indicates that the bond of superoxide anions breaks for the energetically favorable status of oxygen atoms on the surface of PtPdRh. Viability of cells and survival rate of animal models under exposure of high-energy γ radiation are considerably enhanced by 94% and 50% respectively after treatment of PtPdRh nanocubes. The mechanistic investigations on superoxide dismutase (SOD) activity, malondialdehyde amount, and DNA damage repair demonstrate that hollow PtPdRh nanocubes act as catalase, peroxidase, and SOD analogs to efficiently scavenge ROS.