Real-Time Monitoring of Translocation, Dissipation, and Cumulative Risk of Maleic Hydrazide in Potato Plants and Tubers by Ion Exclusion Chromatography.

In this paper, a high-performance ion exclusion chromatographic (ICE) method was developed and applied for monitoring maleic hydrazide (MH) translocation in complex potato plant tissue and tuber matrices. After middle leaf uptake, most MH was trapped and dissipated in the middle leaf, and the rest was transported to other parts mainly through the phloem. Soil absorption significantly reduced the uptake efficiency of the root system, in which MH was partitioned to dissipate in root protoplasts or transfer through the xylem and persisted in the plant. Tuber uptake enabled MH to remain in the flesh and maintain stable levels under storage conditions, but during germination, MH was translocated from the flesh to the growing buds, where it dissipated through the short-day photoperiodic regime. The results demonstrated successful application of the ICE method and provided necessary insights for real-time monitoring of MH translocation behavior to effectively improve potato edible safety.

Fungicidal activity of novel quinazolin-6-ylcarboxylates and mode of action on Botrytis cinerea.

BACKGROUND: Fungal diseases remain important causes of crop failure and economic losses. As the resistance toward current selective fungicides becomes increasingly problematic, it is necessary to develop efficient fungicides with novel chemotypes. RESULTS: A series of novel quinazolin-6-ylcarboxylates which combined the structures of pyridine or heterocyclic motif and the N-(3-chloro-4-fluorophenyl)quinazolin-4-amine moiety, a binding group of ATP-binding site of gefitinib, were evaluated for their fungicidal activity on different phytopathogenic fungi. Most of these compounds showed excellent fungicidal activities against Botrytis cinerea and Exserohilum rostratum, especially compound F17 displayed the highest activity with EC50 values as 3.79 µg mL-1 against B. cinerea and 2.90 µg mL-1 against E. rostratum, which was similar to or even better than those of the commercial fungicides, such as pyraclostrobin (EC50 , 3.68, 17.38 µg mL-1 ) and hymexazol (EC50 , 4.56, 2.13 µg mL-1 ). Moreover, compound F17 significantly arrested the lesion expansion of B. cinerea infection on tomato detached leaves and strongly suppressed grey mold disease on tomato seedlings in greenhouse. The abilities of compound F17 to induce cell apoptosis of the non-germinated spores, to limit oxalic acid production, to reduce malate dehydrogenase (MDH) expression, and to block the active pocket of MDH protein were demonstrated in B. cinerea. CONCLUSION: The novel quinazolin-6-ylcarboxylates containing ATP-binding site-directed moiety, especially compound F17, could be developed as a potential fungicidal candidate for further study. © 2023 Society of Chemical Industry.

Study on Rapid Detection of Pesticide Residues in Shanghaiqing Based on Analyzing Near-Infrared Microscopic Images.

Aiming at guiding agricultural producers to harvest crops at an appropriate time and ensuring the pesticide residue does not exceed the maximum limit, the present work proposed a method of detecting pesticide residue rapidly by analyzing near-infrared microscopic images of the leaves of Shanghaiqing (Brassica rapa), a type of Chinese cabbage with computer vision technology. After image pre-processing and feature extraction, the pattern recognition methods of K nearest neighbors (KNN), naïve Bayes, support vector machine (SVM), and back propagation artificial neural network (BP-ANN) were applied to assess whether Shanghaiqing is sprayed with pesticides. The SVM method with linear or RBF kernel provides the highest recognition accuracy of 96.96% for the samples sprayed with trichlorfon at a concentration of 1 g/L. The SVM method with RBF kernel has the highest recognition accuracy of 79.16~84.37% for the samples sprayed with cypermethrin at a concentration of 0.1 g/L. The investigation on the SVM classification models built on the samples sprayed with cypermethrin at different concentrations shows that the accuracy of the models increases with the pesticide concentrations. In addition, the relationship between the concentration of the cypermethrin sprayed and the image features was established by multiple regression to estimate the initial pesticide concentration on the Shanghaiqing leaves. A pesticide degradation equation was established on the basis of the first-order kinetic equation. The time for pesticides concentration to decrease to an acceptable level can be calculated on the basis of the degradation equation and the initial pesticide concentration. The present work provides a feasible way to rapidly detect pesticide residue on Shanghaiqing by means of NIR microscopic image technique. The methodology laid out in this research can be used as a reference for the pesticide detection of other types of vegetables.

The importance of selecting crystal form for triazole fungicide tebuconazole to enhance its botryticidal activity.

The growing evidences of resistant fungi stimulate fully understanding tebuconazole regarding its crystal structure on fungicidal activity. In this study, the crystal structures of six technical tebuconazoles (BX, HH, JP, QZ, SJ, and YT) were characterized by using high-resolution X-ray powder diffraction and three-dimensional crystal structure modeling. A structure-activity relationship of the tebuconazoles on the susceptible (HLS and YJS) or resistant (XHR) Botrytis cinerea isolates was analyzed, the differential tricarboxylic acid (TCA) cycle metabolism was determined, and molecular docking with sterol 14α-demethylase (CYP51) was performed. The results showed that tebuconazole existed in three types of crystal forms: an overlapping-pair conformation, a side-by-side-pair conformation, and a parallel-pair conformation. QZ with the parallel-pair conformation and the minimum crystal cell volume exhibited a higher activity and a lower resistant level. XHR possessed a higher content of TCA cycle metabolites and phosphate than YJS, but the exposure to QZ significantly reduced the contents of citrate, isocitrate, α-ketoglutarate and oxaloacetate in XHR, as did the exposure to other technical tebuconazoles. Moreover, the point mutations F487L, G464S, and G443S altered the binding properties of chiral stereoscopic R-QZ with CYP51 protein. Especially the G443S mutation promoted a weak linking of R-QZ with LEU380 and TYR126, and greatly slashed the binding action at lower docking score. In conclusion, our results evidenced an efficient crystal conformation of tebuconazole to improve botryticidal activity and a potential adaptability of B. cinerea to tebuconazole inhibition in TCA cycle metabolism and CYP51 protein mutation.

Exposure to emamectin benzoate confers cytotoxic effects on human molt-4 T-cells and possible ameliorative role of vitamin E and dithiothreitol.

Emamectin benzoate (EMB) is an avermectin insecticide that is extensively used for pest control, but there are few reports concerning its cytotoxic effects on human lymphocytes. In the current study, the hematotoxicity of EMB was evaluated in Molt-4 T-cells, a human T-lymphoblastic cell line with high motility, and the role of vitamin E (VitE) and dithiothreitol (DTT) in attenuating EMB cytotoxicity was characterized. Exposure of Molt-4 cells to EMB decreased cell viability and proliferation, induced a loss of cell clusters, and significantly increased membrane collapse and chromatin condensation. Moreover, EMB significantly increased cell death and suppressed transglutaminase activity. EMB treatment modulated the NF-κB signaling pathway, decreased the expression of p105, p50, and p65/RelA in cytosolic and nuclear fractions, and increased nuclear IκBα expression. EMB increased oxidative stress, as demonstrated by a significant increase in the levels of reactive oxygen species (ROS). Treatment with non-cytotoxic concentrations of VitE or DTT ameliorated the hematotoxicity induced by pretreatment with EMB, increased Molt-4 cell viability, raised the IC50 values of EMB, limited intracellular ROS generation, and mitigated EMB-mediated effects on NF-κB signaling. The results indicate the potential cytotoxicity of EMB on human lymphocytes, and demonstrate that VitE and DTT treatment can reduce the cytotoxic effects of EMB.

Synergy of cystamine and pyraclostrobin against Fusarium graminearum involves membrane permeability mitigation and autophagy enhancement.

The application of fungicide mixture is one of the most important measures to extend the service life of highly selective fungicides. Pyraclostrobin (PYR), which has been extensively used to control plant diseases by inhibiting mitochondrial respiration of pathogenic fungi, is at a high risk of resistance development. In this study, the potential of PYR alone or in combination with cystamine, an inhibitor of microbial transglutaminase, to suppress Fusarium graminearum was tested in vitro and in vivo. A synergistic effect of PYR/CYS mixture was observed both in vitro and when applied to etiolated wheat coleoptile. The control effect of PYR/CYS mixture on F. graminearum was better than that of PYR alone, which was reflected by the increased protection effect. The discrepancies of membrane permeability and the redox-physiological state were observed between PYR and PYR/CYS treatments, suggesting that an increased PYR availability in F. graminearum mycelia could be related with the observed synergistic action. Moreover, a synergistic profile was observed between PYR and CYS in regard of massive autophagosomes in mycelia, indicating that enhanced autophagy could be involved in the mode of action of PYR/CYS mixture. The differential content of mitochondrial metabolites between PYR and PYR/CYS treatments also provided evidence for CYS contribution to the fungicidal action of PYR/CYS mixture. The results provide insight into the synergistic mechanism of action of PYR/CYS mixture and an effective way to enhance the efficiency of PYR to combat F. graminearum.

Novel Galactosyl Moiety-Conjugated Furylchalcones Synthesized Facilely Display Significant Regulatory Effect on Plant Growth.

The expansion of weed infestation has increased the demand on new herbicides. A series of novel galactosyl moiety-conjugated furylchalcones was facilely synthesized in which the furyl group (A ring) was combined with the substituted benzene group (B ring), and a galactosyl moiety was introduced. All these galactosyl furylchalcones were predicted to be phloem-mobile. Most of the galactosyl furylchalcones significantly promoted early seedling growth of sorghum and barnyardgrass under dark conditions, but all of them revealed considerable anti-growth ability on illuminated pot plants; especially, 1-(3'-(4″-O-ß-d-galactopyranosyl)furyl)-3-(4″-nitrophenyl)-2-en-1-one (B11) had a better herbicidal activity against rapeseed and Chinese amaranth than haloxyfop-R-methyl. The median efficient concentrations (EC50) of compound B11 against cucumber and wheat were 9.55 and 26.97 mg/L, respectively, also showing a stronger suppressing capacity than 2,4-D. Molecular docking with phosphoenolpyruvate carboxylase protein showed a stable binding conformation in which the galactosyl group interacted with LYS363 and GLU369, the furan ring and carbonyl bound with ARG184, and the crosslink of the nitro group with GLU240 formed a salt bridge. The results demonstrate that galactosyl furylchalcones possess the great potential as new herbicides for weed management, and further evaluations on more weeds are required for practical application.

Near infrared spectral calibration model transfer without standards by screening spectral points with scale invariant feature transform from master samples spectra.

In order to realize calibration model transfer of near infrared (NIR) spectra without standards, scale invariant feature transform (SIFT) algorithm was applied to extract characteristic spectral points of NIR spectra in this study. Three sets of spectral points were selected by SIFT from the spectra of precision detection (SPD) of a radix scutellariae sample by continuously testing the sample three times. Aiming at obtaining high consistency of the three sets, the orthogonal table L9 (34) was used to optimize the parameters of SIFT. Basing on the NIR spectra of several representative radix scutellariae samples, a series of spectral point sets were screened by SIFT with the optimized parameters. Three methods of further treating the spectral points sets to optimize the combination of the spectral points and provided three spectral point sets, which were recorded as Ui, Uu and Uur, respectively. The partial least square (PLS) calibration models for predicting baicalin content of radix scutellariae were built on whole wavelengths, Ui, Uu and Uur at different number of latent variables (nLVs), respectively. Compared with other PLS models, the models of SIFTur-PLS built on Uur, which was obtained by taking union of the firstly selected spectral point sets, then eliminating the points with high deviance of SPD and those with high correlativity from the union, are most robust and always give lower or lowest prediction errors for both master and slave samples at many nLVs. It is a good way to filter stable, highly independent and characteristic spectral points to build robust PLS calibration models by combining SIFT algorithm with standard deviance analysis of SPD and correlative analysis. The models can be directly shared by the slave instrument, without needing transfer sets, and without requiring to correct the spectra of slave instruments or spectral calibration models.

Accurate Analysis of Tricarboxylic Acid Cycle Metabolites and Anion Components in Hemocytes by IC-CD/ESI-MS for Quantifying Insecticide Impairment on Cellular Immunity in Mythimna separata.

Insecticides are more broadly known to affect insect cellular immunity, but the components in hemocytes and their response to insecticide stress are still unknown. In this paper, a method based on trifluoroacetic acid extraction, followed by IC-CD/ESI-MS analysis, was developed to simultaneously determine tricarboxylic acid (TCA) cycle metabolites and anion components in hemocytes from Mythimna separata larvae. Validation gave excellent selectivity, recovery (88.7-107.6%), linear correlation (r2 > 0.9961), precision (<3.89%), LOD (0.002-0.006 mg/L), LOQ (0.006-0.020 mg/L), and a short chromatographic run. The method was verified by administration of 4-((3-chloro-4-fluorophenyl)amino)-7-methoxyquinazolin-6-yl 3-(1,3-dioxoiso-indolin-2-yl) propanoate (QDP) or emamectin benzoate (EMB) to hemocytes in vitro and larvae in vivo. TCA metabolites including citrate, α-ketoglutarate, fumarate, malate, and oxaloacetate, and anions including acetate, oxalate, chloride, carbonate, and sulfate were identified and clearly separated. QDP and EMB showed a biphasic dose effect on TCA metabolites, and the contrary hormesis paralleled the different actions of QDP and EMB. The inhibition or improvement of cellular immunity depended on the QDP concentration. In conclusion, a highly sensitive, reliable, and robust method was developed, enabling the monitoring of hemocyte immunity by the quantification of TCA metabolites and anion components in minute hemocyte samples.

Fungicidal Effect of Pyraclostrobin against Botrytis cinerea in Relation to Its Crystal Structure.

Pyraclostrobin (PYR) is a commonly used strobilurin fungicide, which inhibits mitochondrial respiration at the ubiquinol oxidation center site of the cytochrome bc1 complex. Little information is available regarding the crystal structure of PYR on its fungicidal effect. In this study, the crystal structures of eight PYRs (PYR-A to H) from different sources are determined by using high-resolution X-ray powder diffraction (XRPD) and model construction with the Pawley refinement module. The effects of PYRs on mycelium growth, the kinetics of mycelial growth, conidial germination, and tube elongation of conidia of Botrytis cinerea from tomato are compared. The level of organic acids in the mitochondrial tricarboxylic acid cycle of PYR-treated B. cinerea is analyzed. The results show that PYR-A to PYR-H have their own unique character of XRPD patterns, but the crystal morphology of eight PYRs presents in the triclinic crystal system and space group P1̅. PYR-D with the eclipsed conformation and rational edge angles α (72.599°) and ß (98.612°) in the crystal cell shows the highest inhibitory effect against mycelium growth with EC50 as 3.383 µg mL-1, the best time-dependent effects on the mycelium growth kinetics, and the strongest inhibition on tube elongation of conidia, whereas PYR-E with anticonformation is the worst. Moreover, a significant accumulation of fumarate, malate, and oxalate in the PYR-D-treated mycelium is observed. These findings reinforce the need for a definite crystal structure of PYR to limit usage and mitigate future selection pressure for gray mold management.

Cytotoxic selectivity and apoptosis induction of piericidin A contributes potentially to its insecticidal effect against Mythimna separata (Lepidoptera: Noctuidae) larvae.

Piericidin A (PIA), an active inhibitor of Complex I, is widely used in studies of the anti-bacterial and anti-disease competence, but its physiological and mechanistic effects have rarely been clearly defined in insect individual or insect cells. The present study reveals the considerable insecticidal activity of PIA on Mythimna separata larvae by using a comparison with Aphis craccivora adult, and the cytotoxic selectivity induced by PIA on lepidopteran Tn5B1-4 cells. We demonstrate that the viability of Tn5B1-4 cells is inhibited by PIA in a time- and concentration-dependent manner with IC50 value of 0.061 µM, whilst PIA shows slight inhibitory effect on the viability of HepG2 and Hek293 cells with IC50 value of 233.97 and 228.96 µM, respectively. The inhibitory effect of PIA on the proliferation of Tn5B1-4 cells is significant and persistent, causing a series of morphological changes including cell shrinkage, condensed and fragmented nuclei. Intracellular biochemical assays show that PIA induces apoptosis of Tn5B1-4 cells coincides with a decrease in the mitochondrial membrane potential. PIA in Tn5B1-4 cells can be chelated by EDTA, thereby losing cytotoxicity, whereas exogenous Ca2+ restores the cytotoxicity of PIA by chelating with EDTA in a competitive manner. Our findings highlight the importance of the long-lasting cytotoxicity and the cytoxic selectivity on Tn5B1-4 cells caused by PIA, which ensure the identification of insecticidal effect of PIA against insect pests.

[Analysis of lipophilic components of Salvia miltiorrhiza roots and S. yunnanensis roots by UPLC and LC-MS/MS].

Fingerprints of lipophilic components in the roots of Salvia miltiorrhiza and S.yunnanensis were analyzed by UPLC-DADand UPLC coupled with mass spectroscopy to evaluate the differences and similarities of the lipophilic components in the two kinds of herbs.The UPLC analysis of 18 batches of S.miltiorrhiza and 16 batches of S.yunnanensis was performed on a 25℃Thermo Accucore C_(18)column(2.1 mm×100 mm,2.6µm)by Shimadzu LC-20AD;mobile phase was 0.026%phosphoric acid(A)-acetonitrile(B)with gradient elution;flow rate was 0.4 m L·min~(-1);detection wavelength was set at 270 nm;injection volume was 2µL.The molecular structures of the lipophilic components were analyzed on a 25℃Thermo Accucore C_(18)column(2.1 mm×100 mm,2.6µm)by Thermo U3000 UPLC Q Exactive Orbitrap LC-MS/MS with a mobile phaseconsisting of 0.1%formic acid water(A)and 0.1%formic acidacetonitrile(B).The mass spectrometry was acquired in positive modes using ESI.There are 10 common peaks in the lipophilic components of S.miltiorrhiza.The similarity between the 16 batches of S.miltiorrhiza and their own reference spectra was greater than 0.942,and the average similarity was 0.973.There are 12 common peaks in the lipophilic components of S.yunnanensis.The similarity between the 18 batches of S.yunnanensis and their own reference spectra was greater than 0.937,and the average similarity was 0.976.The similarity between the reference chromatograms of S.miltiorrhiza and S.yunnanensis was only 0.900.There are three lipophilic components in S.yunnanensis,which are not found in S.miltiorrhiza,and one of which isα-lapachone.There is a lipophilic component in S.miltiorrhiza not found in S.yunnanensis,which may be miltirone.The two herbs contain 8 common lipophilic components including dihydrotanshinoneⅠ,cryptotanshinone,tanshinoneⅠ,tanshinoneⅡ_A,nortanshinone in which the content of tanshinoneⅡ_A,dihydrotanshinoneⅠand cryptotanshinone of S.yunnanensisis significantly lower than that of S.miltiorrhiza(P<0.01),and the contents of tanshinoneⅠand nortanshinone are significantly lower than that of S.miltiorrhiza too(P<0.05).There are significant differences in the types and contents of lipophilic components between the roots of S.miltiorrhiza and S.yunnanensis,and the similarity between the fingerprints of interspecies is much lower than that between the same species.Therefore,the roots of S.miltiorrhiza and S.yunnanensis are two kinds of herbs which are quite different in chemical compounds and compositions.

Qualitative analysis of the roots of Salvia miltiorrhiza and Salvia yunnanensis based on NIR, UHPLC and LC-MS-MS.

Near infrared spectroscopy (NIR) was applied to discriminate the roots of salvia miltiorhiza Bunge (Danshen for short) and Salvia yunnanensis C. H. Wright (Zidanshen for short) by means of principal component analysis (PCA), improved and simplified K nearest neighbors (IS-KNN). Furthermore, an ultra-high performance liquid chromatographic (UHPLC) coupled with photodiode-array detector was developed for building fingerprints of lipophilic components of Danshen and Zidanshen, respectively. Basing on NIR information, both PCA and IS-KNN method classified the two kinds of Chinese medical herbs with 100% accuracy. The chromatographic fingerprints of the lipophilic components of Danshen and Zidanshen have 10 and 12 common peaks, respectively. Liquid chromatography coupled with mass spectroscopy (LC-MS-MS) was applied to identify these peaks. Among these, three small peaks in the fingerprints of Zidanshen are not found in Danshen, one of which was identified as α-lapachone, and the other two compounds were not yet identified; a small peak after tanshinone IIA in the fingerprints of Danshen was not found in Zidanshen, which was identified as miltirone. The two herbs have 10 common lipophilic components. The similarity between the two reference chromatograms of Zidanshen and Danshen is 0.902, but the mean similaritie between Zidanshen (or Danshen) fingerprints and its own reference chromatogram is 0.973 (or 0.976). The contents of main lipophilic components are significantly lower in Zidanshen than in Danshen (P < 0.01 or P < 0.05). The results indicate that the two Chinese medical materials are not only different in NIR spectra, but also different in species and quantities of lipophilic components. NIR spectra analysis can identify Danshen and Zidanshen rapidly and accurately. UHPLC coupled with MS analysis demonstrates the detail differences between the two herbs both in species and contents of their lipophilic components.

Screening wavelengths with consistent and stable signals to realize calibration model transfer of near infrared spectra.

Measurement environmental changes and spectral signal differences among multi-spectrometers may lead to big error in the process of transferring the model of near infrared (NIR) spectra to secondary instruments. Basing on the common sense, NIR calibration models could be shared directily among multi-instruments, if they were built on the wavelengths at which the spectral signals of secondary instruments are stable and well consistent with the primary's. Present work advanced a method named as screening wavelengths with consistent and stable signals (SWCSS) to transfer NIR calibration models. It eliminates the wavelengths at which the standard deviation of difference spectra between the primary and secondary instruments (SDDSI) is much higher than the standard deviation of precision detection spectra (SDPDS) of a sample tested on the primary and the wavelengths with higher SDPDS values. So that the spectral signals of different instruments at these selected wavelengths are consistent well and stable. The NIR calibration model is built by partial least square regression (PLS) based on the screened wavelengths. Two datasets of corn and radix scutellariae samples measured with different NIR instruments are used to test the performance of the method. The results show that the overall prediction performance of the SWCSS-PLS models for samples measured on secondaries is much better than that of the full-wavelength PLS models. The root mean square of error prediction (RMSEP) of the SWCSS-PLS models for samples tested on secondaries is equivalent or superior to that of the piecewise direct standardization (PDS) correction. The SWCSS-PLS model is of fewer parameters, robust and can give good prediction results for samples of secondary instruments. Because standard samples are no longer needed during transferring the calibration models to secondary instruments, SWCSS-PLS models could be directly shared by multi-spectroscopy instruments.

The effect of α-tocopherol and dithiothreitol in ameliorating emamectin benzoate cytotoxicity in human K562 cells involving the modulation of ROS accumulation and NF-κB signaling.

Emamectin benzoate (EMB) toxicity contributes a potential risk to environment and human health. To investigate the effect of α-tocopherol (VitE) and dithiothreitol (DTT) in ameliorating EMB-induced cytotoxicity in human K562 cells, in vitro cultured human K562 cells were incubated with different concentrations of EMB in supplement with VitE and DTT when the cells were in the logarithmic phase. Next, the cell growth inhibition was evaluated using the MTT assay and cellular morphology observation. Reactive oxygen species (ROS) production was monitored using DCFH-DA probe and NF-κB signaling was determined using Western blotting. The results demonstrated that treatment with EMB (time- and concentration-dependent) showed significantly greater inhibition on K562 cell viability, heavier chromatin condensation and DNA fragmentation, and stronger suppression of NF-κB/p105 and p65/RelA expression of K562 cells than the control group (p < 0.01). The supplementation of VitE or DTT could help protect K562 cells against EMB-induced cytotoxicity by improving cell viability, preventing ROS accumulation and up-regulating NF-κB signaling through their ameliorating effects against oxidative stress induced by EMB. VitE had a stronger synergistic effect in limiting EMB cytotoxicity than DTT. Our findings indicate that VitE and DTT are potent antioxidants for human K562 cells, offering a promising means of ameliorating EMB cytotoxicity.

[Research progress of pyrolysis combined with ion chromatography].

Ion chromatography (IC) is widely used in the anions and cations analysis for its rapid detection and high sensitivity. With the increasing requirement of detecting organic of samples, developing a suitable pretreatment method is important. Pyrolysis apparatus can be operated automatically and easily with high sensitivity and good repeatability. In the paper, the basic principles and types of burners are introduced. The pyrolysis combined with ion chromatography (pyrolysis-IC) are applied in biology, petroleum, coal, materials, environment and other organic samples. The further development of pyrolysis-IC are also introduced.

Photosensitization of Chinese hamster V79 cells to photoactivated alpha-terthienyl involving membrane damage and oxidative stress.

Photosensitization of V79 Chinese hamster lung fibroblasts was tested to investigate if the cells can fit the photoactive effect of alpha-terthienyl for safety application. Using 15-min photoirradiation of a black light (320-400 nm, 40 W), alpha-terthienyl was significantly photoactivated and caused V79 cells to be shrinkage, detachment and necrosis. The photoactivated alpha-terthienyl played a concentration-dependent stress to decrease cell survival and to induce cell death with median inhibitory concentration (IC50) as 4.78 µg/ml. Cell viability in MTT assays also fell down to 10.58% of the control in the treatment of 10.0 µg/ml photoactivated alpha-terthienyl. As the irradiation time prolonged and the concentration of photoactivated alpha-terthienyl increased, cell death increased significantly, the intracellular level of reactive oxygen species (ROS) and the content of extracellular malondialdehyde were gradually increased. The changes of peroxidase, superoxide dismutase and catalase activities in V79 cells were positively responsive to the oxidative stress caused by photoactivated alpha-terthienyl. Moreover, using non-photosensitizing condition, the increased cell death and oxidative stress in the treatment of alpha-terthienyl at >7.0 µg/ml were also observed. The results showed the maladjustment response of V79 cells with membrane damage and cell death, clearly demonstrating the photosensitization of animal cells to the photoactivated cytotoxic effect of alpha-terthienyl.

Emamectin benzoate induces ROS-mediated DNA damage and apoptosis in Trichoplusia Tn5B1-4 cells.

Emamectin benzoate (EMB), a novel macrocyclic lactone insecticide, possesses high efficacy and beneficial selective toxicity in agriculture, but so far the EMB-induced cytotoxic action in arthropod insect remains unclear. The present studies were carried out to characterize the property of EMB on the induction of reactive oxygen species (ROS)-mediated DNA damage and apoptosis in Trichoplusia Tn5B1-4 cell model. Following the exposure to EMB at 2.5, 5, 10 or 15 µM, the cells changed to be round, suspended and aggregated, and the decline of cell proliferating ability and cell viability was positively related with the exposure time. Median inhibitory concentration (IC50) of EMB on cell viability was 3.72 µM during 72 h exposure. Apoptosis was induced in 29.8% (24 h) and 39.5% (48 h) of the cells by EMB at 15 µM, showing chromatin condensation in nuclei. The content of ROS in the cells increased rapidly as the concentration of EMB increased, and the pre-incubation of the cells with vitamin E significantly reduced the ROS accumulation. In the treatment of 15 µM EMB, the migrated cell nucleus with DNA strand breaks appeared a teardrop, pear-shaped, or large fan-like tail, and 63.1% of γH2AX-positive cells contained more than four foci, accompanying with high expression level of caspase-3 in time-dependent manner, which consequently led to cell apoptotic death. These evidences in ROS-mediated DNA damage and cell apoptosis induced by EMB may be helpful for deep understanding the cytotoxic action of EMB based on cell model.

[Exploration of rapidly determining quality of traditional Chinese medicines by (NIR) spectroscopy based on internet sharing mode].

Because of the numerous varieties of herbal species and active ingredients in the traditional Chinese medicine(TCM),the traditional methods employed could hardly satisfy the current determination requirements of TCM.The present work proposed an idea to realize rapid determination of the quality of TCM based on near infrared(NIR)spectroscopy and internet sharing mode. Low cost and portable multi-source composite spectrometer was invented by our group for in-site fast measurement of spectra of TCM samples. The database could be set up by sharing spectra and quality detection data of TCM samples among TCM enterprises based on the internet platform.A novel method called as keeping same relationship between X and Y space based on K nearest neighbors(KNN-KSR for short)was applied to predict the contents of effective compounds of the samples. In addition,a comparative study between KNN-KSR and partial least squares(PLS)was conducted. Two datasets were applied to validate above idea:one was about 58 Ginkgo Folium samples samples measured with four near-infrared spectroscopy instruments and two multi-source composite spectrometers,another one was about 80 corn samples available online measured with three NIR instruments. The results show that the KNN-KSR method could obtain more reliable outcomes without correcting spectrum.However transforming the PLS models to other instruments could hardly acquire better predictive results until spectral calibration is performed. Meanwhile,the similar analysis results of total flavonoids and total lactones of Ginkgo Folium samples are achieved on the multi-source composite spectrometers and near-infrared spectroscopy instruments,and the prediction results of KNN-KSR are better than PLS. The idea proposed in present study is in urgent need of more samples spectra, and then to be verified by more case studies.

Electric papers of graphene-coated Co3O4 fibers for high-performance lithium-ion batteries.

A facile strategy to synthesize the novel composite paper of graphene nanosheets (GNS) coated Co(3)O(4) fibers is reported as an advanced anode material for high-performance lithium-ion batteries (LIBs). The GNS were able to deposit onto Co(3)O(4) fibers and form the coating via electrostatic interactions. The unique hybrid paper is evaluated as an anode electrode for LIBs, and it exhibits a very large reversible capacity (∼840 mA h g(-1) after 40 cycles), excellent cyclic stability and good rate capacity. The substantially excellent electrochemical performance of the graphene/Co(3)O(4) composite paper is the result from its unique features. Notably, the flexible structure of graphenic scaffold and the strong interaction between graphene and Co(3)O(4) fibers are beneficial for providing excellent electronic conductivity, short transportation length for lithium ions, and elastomeric space to accommodate volume varies upon Li(+) insertion/extraction.