51 research outputs found
Advanced Research on cis-Neonicotinoids
cis-Neonicotinoids are a type of neonicotinoid, in which the nitro or the cyano group are in cis-configuration relative to heteroaromatic moiety, which show excellent activities against a range of insect species. This review covers cis-neonicotinoids with commercialization
perspectives, structural optimization (phenylazoneonicotinoids and chlorothiazolyl analogues of Paichongding), modes of action studies, radiao-synthesis of Paichongding and Cycloxaprid, and photostability of neonicotinoids
Effect of 5/6 Nephrectomized Rat Serum on Epithelial-to-Mesenchymal Transition In Vitro
Objective: To investigate whether the 5/6 nephrectomized (5/6Nx) ratsā 12-week serum could lead to tubular epithelial-to-mesenchymal transition (EMT) and its molecular mechanism, so as to probe the potential stimulation from circulation in chronic progressive kidney disease. Methods: A total of 24 Sprague Dawley (SD) rats were randomly divided into two groups: sham operation group (sham group) and 5/6Nx group. Rats were killed 12 weeks after surgery to obtain 5/6Nx ratsā 12-week serum. Then we detected the expression of E-cadherin in renal tubular epithelial cells of the remaining kidney and we investigated whether the 12th week serum of 5/6Nx rats could cause HK-2 (human kidney proximal tubular cell line) cells to transdifferentiate into fibroblasts. Results: Our data confirmed that E-cadherin expression decreased significantly in the remaining kidney at 12 weeks, and the 5/6Nx ratsā 12-week serum could suppress E-cadherin protein and mRNA expression (p < 0.05). We also found that the 5/6Nx ratsā 12-week serum could upreg-ulate ZEB1, Ī²-catenin, and wnt3 protein expression (p < 0.05). Conclusions: Our results demonstrated that the 5/6Nx ratsā 12-week serum could suppress the expression of E-cadherin in HK-2 cells. It was partially through modulating the increase of ZEB1. The loss of E-cadherin could lead Ī²-catenin to localize to the cytoplasm and nucleus, and feed into the Wnt signaling pathway. It means that the pathogenic serum in chronic kidney disease (CKD) plays an important role in the loss of renal function and turns to be a new avenue of research with potential clinical implications
Cluster-Based Improved Isolation Forest
Outlier detection is an important research direction in the field of data mining. Aiming at the problem of unstable detection results and low efficiency caused by randomly dividing features of the data set in the Isolation Forest algorithm in outlier detection, an algorithm CIIF (Cluster-based Improved Isolation Forest) that combines clustering and Isolation Forest is proposed. CIIF first uses the k-means method to cluster the data set, selects a specific cluster to construct a selection matrix based on the results of the clustering, and implements the selection mechanism of the algorithm through the selection matrix; then builds multiple isolation trees. Finally, the outliers are calculated according to the average search length of each sample in different isolation trees, and the Top-n objects with the highest outlier scores are regarded as outliers. Through comparative experiments with six algorithms in eleven real data sets, the results show that the CIIF algorithm has better performance. Compared to the Isolation Forest algorithm, the average AUC (Area under the Curve of ROC) value of our proposed CIIF algorithm is improved by 7%
Study on the Land Reclamation of Oilfield of Gurbantunggut Desert in Junggar Basin
The exploration and development of oilfield results in damages to land resources. Along with the further development of petroleum in the Gurbantunggut Desert, the fragile ecological environment and land resource was suffering much more damage. Vegetation degradation and desertification become more prominent. In response to the damage to the fragile ecological environment and oilfield in the Gurbantunggut Desert, limit condition method was used to evaluate the suitability of land reclamation suitability. Results suggested that the main restraining factors for land reclamation were soil condition and water resources. Based on the effect and shortage of oilfield in the Gurbantunggut Desert Oilfield, the reclamation of oilfield in the Gurbantunggut desert was discussed
Analysis of magnetostriction of oriented silicon steel under motor magnetic field
The performance requirements of motors are gradually increasing, and anisotropic soft magnetic materials have been applied in motors to improve performance, The magnetostriction of anisotropic soft magnetic materials is one of the main contributors in extensive research on anisotropic soft magnetic material transformers. Compared to transformers, the magnetic field in motors has more complex harmonic and multi-directional characteristics. In this paper, the magnetic field of motors stator teeth under both no-load and load conditions is calculated and analyzed to research magnetostriction of anisotropic soft magnetic materials in motor magnetic field and predict the NVH performance of anisotropic soft magnetic material motors accurately. Furthermore, the magnetostriction in different magnetization angles is investigated for the multi-directional characteristics, and the result is explained from microscopic principles. This paper focuses on a splicing oriented silicon steel (OSS) motor, the magnetization angle of OSS in motor varying from 0Ā° to 90Ā°. Firstly, the equivalent formulas of magnetic field are obtained under the analytical and finite element calculations. After that, the frequency and direction of experiment magnetic field are confirmed and the magnetostriction of OSS in different magnetization angle and frequency is measured. In the end, the variation character of magnetostriction of OSS is summarized
Synthesis, Insecticidal Activity, and QSAR of Novel Nitromethylene Neonicotinoids with Tetrahydropyridine Fixed cis
Molecular Mechanism of Action of Cycloxaprid, An Oxabridged <i>cis</i>-Nitromethylene Neonicotinoid
Cycloxaprid, an oxabridged cis-nitromethylene neonicotinoid, showed high insecticidal activity in Hemipteran insect pests. In this study, the action of cycloxaprid was characterized by recombinant receptor NlĪ±1/rĪ²2 and cockroach neurons. On NlĪ±1/Ī²2 in Xenopus oocytes, cycloxaprid acted as a full agonist. The imidacloprid resistance-associated mutation Y151S reduced the Imax of cycloxaprid by 37.0% and increased EC50 values by 1.9-fold, while the Imax of imidacloprid was reduced by 72.0%, and EC50 values increased by 2.3-fold. On cockroach neurons, the maximum currents elicited by cycloxaprid were only 55% of that of acetylcholine, a full agonist, but with close EC50 values of that of trans-neonicotinoids. In addition, cycloxaprid inhibited acetylcholine-evoked currents on insect neurons in a concentration-dependent manner when co-applied with acetylcholine. Cycloxaprid at low concentrations significantly inhibited the activation of nAChRs by acetylcholine, and its inhibition potency at 1 ĀµM was higher than its activation potency on insect neurons. Two action potencies, activation, and inhibition, by cycloxaprid on insect neurons provided an explanation for its high toxicity to insect pests. In summary, as a cis-nitromethylene neonicotinoid, cycloxaprid showed high potency on both recombinant nAChR NlĪ±1/Ī²2 and cockroach neurons, which guaranteed its high control effects on a variety of insect pests
Synthesis and Biological Activity Evaluation of Novel <em>Ī²</em>-Substituted Nitromethylene Neonicotinoid Analogues
The structure-based design and synthesis of a series of novel neonicotinoid analogues are described. The novel neonicotinoid analogues were designed based upon the reaction of enamine derivatives with electron-withdrawing <em>Ī²</em>-substituents with electrophilic thiocyanogen reagents. These compounds were characterized by spectroscopic methods. Bioassays indicated that some of the synthesized compounds exhibited excellent bioactivity against cowpea aphids (<em>Aphis craccivora</em>). The LC<sub>50</sub> values of compounds <strong>7</strong>, <strong>9</strong>, <strong>12</strong>, <strong>13</strong>, <strong>15</strong>, <strong>17</strong>, <strong>19</strong>, <strong>20</strong> and commercial imidacloprid were 0.01567, 0.00974, 0.02494, 0.01893, 0.02677, 0.01778, 0.0220, 0.02447 and 0.03502 mmol L<sup>ā1</sup>, respectively, which suggested that they could be used as leads for future development of new insecticides
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