Magnetically controlled colorimetric aptasensor for chlorpyrifos based on copper-based metal-organic framework nanoparticles with peroxidase mimetic property.

The fabrication of a magnetically controlled colorimetric aptasensor for chlorpyrifos is reported. The aptasensor was fabricated by the attachment of the colorimetric labels onto the magnetic carrier due to the hybridization reaction between the complementary DNA and aptamer. Chlorpyrifos detection was realized by monitoring the color changes of the TMB/H2O2 solution before and after incubation of the aptasensor with chlorpyrifos via exposure to external magnetic force. The color change was monitored at 650 nm by UV-Vis spectrophotometer. Under the optimal conditions, this magnetically controlled Cu-MOF-based aptasensor showed a detection limit of 4.4 ng/mL with a linear range of 0-1250 ng/mL. The colorimetric aptasensor displayed high selectivity for chlorpyrifos toward other interfering pesticides. The aptasensor was successfully applied for the spiked test of chlorpyrifos in fruits and vegetable samples with good recovery, which were in agreement with data obtained by GC-MS analysis. This magnetically controlled Cu-MOF-based sensing strategy not only leads to development of efficient and facile phase separation, but also expands the MOF's target scope from H2O2 or glucose to pesticides. Graphical abstract.

Effects of ultraviolet-c treatment on growth and mycotoxin production by Alternaria strains isolated from tomato fruits.

Large amounts of tomato fruits and derived products are produced in China and may be contaminated by Alternaria mycotoxins, which may have the potential risks for human health. There is thus an increasing interest in reducing the mycotoxins. In the present study, 26 Alternaria strains isolated from tomato black rots were identified according to morphological and molecular grounds, and their mycotoxigenic abilities for alternariol (AOH), alternariol monomethyl-ether (AME) and tenuazonic acid (TeA) were also investigated. The results showed that A. alternate was the predominant species with incidence values of 65.4% (17/26), followed by A. brassicae (7/26) and A. tenuissima (2/26). A. alternate isolates showed the highest capacity for AOH, AME and TeA production among the studied isolates either in vitro or in vivo, suggested that A. alternata may be the most important mycotoxin-producing species in tomato fruits. Thus, UV-C irradiation was used to reduce the mycotoxin produced by A. alternata in our study. The results showed that low dose of UV-C irradiation (0.25 kJ/m2) could effectively inhibit mycotoxins production and penetration in tomatoes. Upon treatment with UV-C, there was 79.6, 76.4 and 51.4% of reduction in AOH, AME and TeA penetration when compared to untreated fruits. This may be associated with the enhanced phenolics by UV-C irradiation. In fact, the induced phenolics were including p-coumaric, ferulic and pyrocatechuic acids, of which p-coumaric acid (1.0 mM) displayed the highest reduction of TeA with 60.2%, whereas ferulic acid (1.0 mM) showed strong inhibitory effects on the AOH and AME production by 59.4 and 79.1%, respectively. Therefore, the application of UV-C irradiation seems to be a promising method for reducing the potential risk of Alternaria mycotoxins in fruits and also for enhancing phenolics of processing products.

Use of ultra-performance liquid chromatography-tandem mass spectrometry on sweet cherries to determine phenolic compounds in peel and flesh.

BACKGOUND: Sweet cherries (Prunus avium L.) are rich in polyphenols and have high antioxidant potential. This study deals with the use of ultra-performance liquid chromatography-tandem mass spectrometry on five cherry cultivars, namely Caihong, Sunburst, Summit, 23-51 and Valeri, to determine the free, conjugated and bound phenolics in peel and flesh. RESULTS: Phenolics varied widely based on cherry cultivars and edible parts. Valeri showed the highest phenolics in peel, while the flesh of 23-51 contained a higher amount of phenolic substances compared with the other cherries, mainly due to high levels of cyanidin-3-O-rutinoside, which was the most abundant phenolic in sweet cherry. Most of the phenolics, except for ferulic acid and vanillic acid, were present at a higher level in peel than in flesh. Principal component analysis indicated that compared with different edible parts, the phenolic compounds were more influenced by cultivar. CONCLUSIONS: Cultivar had a much greater impact on the accumulation of phenolics than edible parts. The peel of Valeri contained the highest phenolics; for the flesh, 23-51 had the highest levels. The high variability in phenolic compounds in peel and flesh among cultivars may be useful for breeding and underlines the importance of germplasm conservation activities. © 2019 Society of Chemical Industry.

Characterization of Phenolic Compounds from Early and Late Ripening Sweet Cherries and Their Antioxidant and Antifungal Activities.

Early and late ripening sweet cherries were characterized for phenolic acids, and also their antioxidant capacity and potential antifungal effects were investigated. Free, conjugated, and bound phenolics were identified and quantified using ultra performance liquid chromatography-tandem mass spectrometry. Our results indicated that the early ripening cultivars contained higher free phenolic acids, which was positively related to remarkable antioxidant properties and the inhibition effects on Alternaria alternata and tenuazonic acid (TeA) accumulation. However, conjugated phenolics of the late ripening cultivars, mainly including caffeic, 2,3,4-trihydroxybenzoic, p-coumaric, and pyrocatechuic acids, achieved the highest antifungal effects and almost completely inhibited the A. alternata and TeA production. 2,2-Diphenyl-1-picrylhydrazyl testing and ferric ion reducing antioxidant power assay showed strong positive correlation with total phenolics and specific phenolics such as free epicatechin and conjugated 2,3,4-trihydroxybenzoic acids and also with antifungal activity. Results from this study provide further insights into the health-promoting phenolic compounds in sweet cherries.

Visual cortex and auditory cortex activation in early binocularly blind macaques: A BOLD-fMRI study using auditory stimuli.

Cross-modal plasticity within the visual and auditory cortices of early binocularly blind macaques is not well studied. In this study, four healthy neonatal macaques were assigned to group A (control group) or group B (binocularly blind group). Sixteen months later, blood oxygenation level-dependent functional imaging (BOLD-fMRI) was conducted to examine the activation in the visual and auditory cortices of each macaque while being tested using pure tones as auditory stimuli. The changes in the BOLD response in the visual and auditory cortices of all macaques were compared with immunofluorescence staining findings. Compared with group A, greater BOLD activity was observed in the bilateral visual cortices of group B, and this effect was particularly obvious in the right visual cortex. In addition, more activated volumes were found in the bilateral auditory cortices of group B than of group A, especially in the right auditory cortex. These findings were consistent with the fact that there were more c-Fos-positive cells in the bilateral visual and auditory cortices of group B compared with group A (p < 0.05). In conclusion, the bilateral visual cortices of binocularly blind macaques can be reorganized to process auditory stimuli after visual deprivation, and this effect is more obvious in the right than the left visual cortex. These results indicate the establishment of cross-modal plasticity within the visual and auditory cortices.

Systematic review and meta-analysis of randomized controlled trials on Wenxin keli.

OBJECTIVE: The aim of the study was to evaluate the effectiveness, safety, and cost associated with Wenxin keli in the treatment of cardiovascular diseases based on meta-analysis. METHODS: The terms "Wenxin keli" and "Wenxin" were used as the search terms in the PubMed, ProQuest, Springer, the Cochrane Library, CNKI (China National Knowledge Infrastructure), VIP (Chinese Scientific Journals Database), and Wan fang electronic databases (from January 2000 to October 2015). Relevant print journals and conference papers were also searched. Studies on randomized controlled trials (RCTs) of Wenxin keli used in the treatment of cardiovascular diseases were screened, and its indications were classified. Meta-analysis of these studies was conducted using the RevMan 5.2 software. RESULTS: A total of 49 RCTs (n=4,610) were included, 29 of which focused on arrhythmia, seven on angina, seven on heart failure, two on viral myocarditis, and four on menopausal syndrome. Analysis of the therapeutic indications of Wenxin keli showed that it was comparatively more curative and effective than other available treatments for cardiovascular diseases. CONCLUSION: Wenxin keli showed better clinical efficacy in the treatment of arrhythmia, angina, and heart failure; however, more high-quality evidence is needed to support its use in the clinical setting.

Comparison of USPIO-enhanced MRI and Gd-DTPA enhancement during the subacute stage of focal cerebral ischemia in rats.

BACKGROUND: Being one class of magnetic resonance imaging (MRI) contrast agents, ultrasmall superparamagnetic particles of iron oxides (USPIO) bear the potential to study neuroinflammation following stroke, but there is still debate over whether the iron oxides particles may enter the brain tissue passively over a damaged blood-brain barrier (BBB). PURPOSE: To compare the enhancement patterns of USPIO and gadopentate dimeglumine (Gd-DTPA) during the subacute stage of focal cerebral ischemia, to examine the relationship between USPIO enhancement and BBB disturbance, as well as with neuroinflammatory cell response. MATERIAL AND METHODS: Multiple MR sequences were obtained on days 3 and 6 after transient middle cerebral artery occlusion induced in rats with and without the application of USPIO and Gd-DTPA. The enhancement patterns of the two contrast agents were compared and correlated to histology, including IgG for BBB permeability, Prussian Blue staining for iron particle detection, and CD68 immunohistochemistry staining to identify macrophage/microglia. RESULTS: Gd-DTPA enhancement depicted BBB breakdown being in line with IgG leakage. The USPIO enhanced images demonstrated both diffuse and focal signal alteration in ischemic lesions. The diffuse enhanced pattern had a similar spatial and temporal profile as with Gd-DTPA enhancement. In addition, focal enhanced signal loss was visible on T1-, T2-, and T2*-weighted images, with a peak tendency of MR signal loss, macrophage/microglia concentration and iron particle accumulation at a later phase of the study. CONCLUSION: After focal cerebral ischemia, Gd-DTPA-enhanced MRI showed a higher sensitivity in detecting BBB alterations than did USPIO enhancement. USPIO provided complementary information regarding inflammatory cell activity in neuroinflammatory to cerebral ischemia that had not been visualized using conventional Gd-DTPA. The assessment using multiple MR parameters may identify intracellular and extracellular USPIO in vivo.

Can electroacupuncture affect the sympathetic activity, estimated by skin temperature measurement? A functional MRI study on the effect of needling at GB 34 and GB 39 on patients with pain in the lower extremity.

The Purpose of this study was to investigate the possible needling effect on sympathetic activity by using functional MRI (fMRI). Twelve patients with left lower extremity pain were enrolled in our study. Each was given deep needling at left GB34 (yanglingquan) and GB39 (xuanzhong) points simultaneously. All patients got the strong DeQi sensation by manipulating the needles, and then electroacupucture (EA) was given and lasted for thirty minutes before fMRI scan. Then the fMRI scan was performed by scanning the whole brain with five blocks lasting 2 minutes each. The patients' palm skin temperatures were tested every five minutes as indication of the sympathetic activity from the beginning of EA to the end of our fMRI scan. Functional images were processed by using FEAT software at different levels including the simple single subject analysis, multi-subjects group mean analysis, and multi-subjects unpaired two difference analysis. Finally, 9 of 12 patients' palm temperatures increased gradually but the other three decreased. In comparison of two different palm skin temperature change groups, more significant activation over bilateral caudate head, right lentiform and periaqueductal gray (PAG) were found in the temperature-increased group, but palm temperature-decreased patients revealed more significant activation over bilateral anterior cingulated cortex (ACC), insula, primary somatosensory gyrus (SI), orbitofrontal cortex, occipital cortex, hippocampus and amygdala formation. Our study suggested that needling at analgesic points may modulate the sympathetic activity and such evident difference on brain responses may correlate with the clinical analgesia effects.