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Based on the location of bromine substituents and conjugation matrix, a new substituent position index 0X not only was defined, but also molecular shape indexes Km and electronegativity distance vectors Mm of diphenylamine and 209 kinds of polybrominated diphenylamine (PBDPA) molecules were calculated. Then the quantitative structure-property relationships (QSPR) among the thermodynamic properties of 210 organic pollutants and 0X, K3, M29, M36 were founded by Leaps-and-Bounds regression. Using the four structural parameters as input neurons of the artificial neural network, three satisfactory QSPR models with network structures of 4:21:1, 4:24:1, and 4:24:1 respectively, were achieved by the back-propagation algorithm. The total correlation coefficients R were 0.9999, 0.9997, and 0.9995 respectively and the standard errors S were 1.036, 1.469, and 1.510 respectively. The relative mean deviation between the predicted value and the experimental value of S⊖, ΔfH⊖ and ΔfG⊖ were 0.11%, 0.34% and 0.24% respecti...

Ecdysone 20-monooxygenase (E20MO), a cytochrome P450 monooxygenase (CYP314A1), catalyses the conversion of ecdysone (E) to 20-hydroxyecdysone (20E). We report here the cloning and characterization of the Halloween gene Shade (Shd) encoding E20MO in the Colorado potato beetle, Leptinotarsa decemlineata. LdSHD has five conserved motifs typical of insect P450s, ie the Helix-C, Helix-I, Helix-K, PxxFxPE/DRF (PERF) and heme-binding motifs. LdShd was expressed in developing eggs, the first to fourth instars, wandering larvae, pupae and adults, with statistically significant fluctuations. Its mRNA was ubiquitously distributed in the head, thorax and abdomen. The recombinant LdSHD protein expressed in Spodoptera frugiperda 9 (Sf9) cells catalysed the conversion of E to 20E. Dietary introduction of double-stranded RNA (dsRNA) of LdShd into the second instar larvae successfully knocked down the LdShd expression level, decreased the mRNA level of the ecdysone receptor (LdEcR) gene, caused larval lethality, delayed development and affected pupation. Moreover, ingestion of LdShd-dsRNA by the fourth instars also down-regulated LdShd and LdEcR expression, reduced the 20E titre, and negatively influenced pupation. Introduction of 20E and a nonsteroidal ecdysteroid agonist halofenozide into the LdShd-dsRNA-ingested second instars, and of halofenozide into the LdShd-dsRNA-ingested fourth instars almost completely relieved the negative effects on larval performance. Thus, LdSHD functions to regulate metamorphotic processes by converting E to 20E in a coleopteran insect species Le. decemlineata.

A simple, one-step process including the self-assembly of organo-layered double hydroxides and removal of disperse dye simultaneously has been proposed. This one-step process can hopefully be applied for dye effluents removal due to its low operation cost and simplified process compared with a traditional organo-layered double hydroxides process. Here, the self-assembly of organo-layered double hydroxides was realized by adding both raw layered double hydroxides and the anionic surfactant sodium dodecylsulfate into wastewater, and then the one-step process was applied to remove disperse violet 28 from dyeing wastewater. The results showed a higher removal efficiency of disperse violet 28 in this one-step process than in a traditional organo-layered double hydroxide process because cooperative removal and synergism between the surfactant and disperse violet 28 in solution occurred to a large extent. The adsorption isotherm data could be described by the linear model, indicating a partitioning adsorption process. The adsorption kinetics was found to be well presented by the pseudo-second-order model, and the high activation energy (56.64 kJ mol−1) indicated that the adsorption was mainly a chemical process.

The Colorado potato beetle (Leptinotarsa decemlineata [Say]) in the north Xinjiang Uygur autonomous region in China has evolved resistance to pyrethroids and carbamates. Mutations resulting in target site insensitivity, namely L1014F in LdVssc1 voltage-sensitive sodium channel and S291G in acetylcholine esterase, confer, at least partially, the resistance. Insecticides with different modes of action may serve as likely replacements. Endosulfan and fipronil are GABA-gated chloride channel-blocking insecticides. In this article, we found that the contact toxicities of the two compounds were among the highest ever estimated to the 4th-instar larvae and the adults and affirmed that they were useful for L. decemlineata control in north Xinjiang. Regarding stomach toxicities of the two compounds, adult beetles were less sensitive than 2nd-, 3rd-, and 4th-instar larvae, suggesting that the appropriate timing for spraying is the early larval stage. Mixtures of endosulfan and α-cypermethrin at 1:160, 1:80, and 1:40 ratios, of endosulfan and phoxim at 1:24 ratio, and of endosulfan and isocarbophos at 1:72 and 1:288 ratios, significantly increased toxicity in a field population. The combination indices were significantly below 1 at both LD50 and LD90 levels, revealing synergistic effects. Our results demonstrated that endosulfan and fipronil could be applied alone and endosulfan may also be used in binary mixtures to restore pyrethroid susceptibility. These findings may have considerable practical implications for L. decemlineata resistance management.

A survey of resistance to five conventional insecticides was conducted in 2009 and 2010 for the first generation 4th-instar larvae of Leptinotarsa decemlineata from Urumqi, Changji, Qitai and Qapqal. Compared with the Tekes population, a reference susceptible population, the Changji and Qapqal populations exhibited very high to moderate levels of resistance to cyhalothrin and deltamethrin, moderate to high levels of resistance to carbosulfan and carbofuran, and low levels of resistance to azinphosmethyl. Moreover, the Urumqi and the Qitai populations reached a high and a moderate level of resistance to carbosulfan, respectively. Synergistic effects of triphenyl phosphate, diethylmeleate, and piperonyl butoxide on cyhalothrin and carbosulfan in Changji population revealed that cytochrome P450s were involved in the resistance to cyhalothrin but not carbosulfan. A modified bi-PASA was developed to simultaneously detect point mutations of S291G in the AChE and L1014F in the LdVssc1 genes. The former mutation resulted in the resistance to carbamates and the latter in the resistance to pyrethroids. The rates of homozygous and heterozygous resistant individuals to carbamates (S291G mutation) were 17.6% and 14.7%, 50.6% and 42.2%, 49.9% and 41.7%, 51.3% and 41.4%, and 44.8% and 47.4%; to pyrethroids (L1014F mutation) were 5.8% and 8.7%, 36.1% and 27.0%, 41.8% and 24.8%, 12.2% and 9.7%, and 7.9% and 10.6%, respectively, in samples from Tekes, Changji, Qapqal, Urumqi and Qitai. I392T point mutation in the AChE was detected by RT-PCR among 18 individuals from Changji, Qapqal, Urumqi and Qitai. These results demonstrated that point mutations of S291G in the AChE and L1014F in the LdVscc1 are responsible for, at least partially, the resistance to carbamates and pyrethroids in L. decemlineata in some field populations in northern Xinjiang Uygur autonomous region.

J. Agric. Urban Entomol. 27: 61-73 (2010/2011) ABSTRACT The Colorado potato beetle Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae) in the northern part of the Xinjiang Uygur Autonomous Region has evolved resistance to several pyrethroid and carbamate insecticides. Biological control methods should be a major component of integrated pest management for L. decemlineata. Spinosad and abamectin are two biopesticides that have unique mechanisms of action. In this study, the contact toxicities of spinosad and abamectin to L. decemlineata fourth instars and adults were determined by topical applica- tions to several field populations. The average LD50 values of spinosad and abamectin for adults were 0.1275 and 0.0101 mg (a.i.) per individual, and for fourth instars they were 0.0181 and 0.0016 mg (a.i.) per individual, respectively. These data were among the lowest LD50s ever estimated, which affirmed that the two biopesticides are useful for L. decemlineata control in north Xinjiang. Susceptibilities to the two biopesticides varied slightly but significantly among tested field populations and the variations did not result from cross-resistance to conventional insecticides. Regarding stomach toxici- ties, the LC50 values of spinosad applied to excised potato leaves for second instars, third instars, fourth instars, and adults were 0.2840, 0.4093, 1.2413, and 2.3783 mg/L (a.i.), respectively. The LC50 values of abamectin for second instars, third instars, fourth instars, and adults were 0.0036, 0.0088, 0.0177, and 0.2591 mg/L (a.i.), respectively. The two biopesticides were most toxic to second instars, followed by third, then fourth instars, and they were least toxic to adults. These data suggested that the appropriate timing for spinosad or abamectin spraying is to early larval stages.

Adipocytes express the cystathionine γ lyase (CSE)-hydrogen sulfide (H2S) system. CSE-H2S promotes adipogenesis but ameliorates adipocyte insulin resistance. We investigated the mechanism of how CSE-H2S induces these paradoxical effects. First, we confirmed that an H2S donor or CSE overexpression promoted adipocyte differentiation. Second, we found that H2S donor inhibited but CSE inhibition increased phosphodiesterase (PDE) activity. H2S replacing isobutylmethylxanthine in the differentiation program induced adipocyte differentiation in part. Inhibiting PDE activity by H2S induced peroxisome proliferator activated receptor γ (PPARγ) protein and mRNA expression. Of note, H2S directly sulfhydrated PPARγ protein. Sulfhydrated PPARγ increased its nuclear accumulation, DNA binding activity and adipogenesis gene expression, thereby increasing glucose uptake and lipid storage, which were blocked by the desulfhydration reagent DTT. H2S induced PPARγ sulfhydration, which was blocked by mutation of the C139 site of PPARγ. In mice fed a high-fat diet (HFD) for 4 weeks, the CSE inhibitor decreased but H2S donor increased adipocyte numbers. In obese mice fed an HFD for 13 weeks, H2S treatment increased PPARγ sulfhydration in adipose tissues and attenuated insulin resistance but did not increase obesity. In conclusion, CSE-H2S increased PPARγ activity by direct sulfhydration at the C139 site, thereby changing glucose into triglyceride storage in adipocytes. CSE-H2S-mediated PPARγ activation might be a new therapeutic target for diabetes associated with obesity.