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Pests represent an important impediment to efficient agricultural production and pose a threat to global food security. On the basis of our prior research focused on identifying insecticidal leads targeting insect ryanodine receptors (RyRs), we aimed to identify evodiamine scaffold-based novel insecticides. Thus, a variety of evodiamine-based derivatives were designed, synthesized, and assessed for their insecticidal activity against the larvae of Mythimna separata(M. separata) and Plutella xylostella(P. xylostella). The preliminary bioassay results revealed that more than half of the target compounds exhibited superior activity compared to evodiamine, matrine, and rotenone against M. separata. Among these, compound 21mdisplayed the most potent larvicidal efficiency, with a remarkable mortality rate of 93.3% at 2.5 mg/L, a substantial improvement over evodiamine (10.0% at 10 mg/L), matrine (10.0% at 200 mg/L), and rotenone (30.0% at 200 mg/L). In the case of P. xylostella, compounds 21mand 21odisplayed heightened larvicidal activity, boasting LC50values of 9.37 × 10–2and 0.13 mg/L, respectively, surpassing that of evodiamine (13.41 mg/L), matrine (291.78 mg/L), and rotenone (18.39 mg/L). A structure–activity relationship analysis unveiled that evodiamine-based derivatives featuring a cyclopropyl sulfonyl group at the nitrogen atom of the B ring and a fluorine atom in the E ring exhibited more potent larvicidal effects. This finding was substantiated by calcium imaging experiments and molecular docking, which suggested that 21mcould target insect RyRs, including resistant mutant RyRs of P. xylostella(G4946E and I4790M), with higher affinity than chlorantraniliprole (CHL). Additionally, cytotoxicity assays highlighted that the potent compounds 21i, 21m, and 21odisplayed favorable selectivity and low toxicity toward nontarget organisms. Consequently, compound 21memerges as a promising candidate for further development as an insecticide targeting insect RyRs.

C/SiC volume ratios in carbon fiber-reinforced carbon-silicon carbide (Cf/C–SiC) composites may influence greatly mechanical and oxidation properties of the composites, but have not been well investigated yet. Herein, Cf/C–SiC composites with different C/SiC volume ratios were fabricated by chemical vapor infiltration (CVI) technique through alternating the thickness of a pyrocarbon (PyC) interlayer. The composites with C/SiC volume ratios of 0.37 and 0.84 exhibited the better comprehensive mechanical properties. The CS0.37 showed the highest flexural strength of 340.6 MPa, and CS0.84 had the maximum tensile strength of 139.1 MPa. The excellent mechanical properties were closely related to the relatively low C/SiC volume ratios and porosities, optimum interfacial bonding and reduced matrix micro-cracks. The composite with a low C/SiC volume ratio of 0.10 showed the best anti-oxidation performance due to its high SiC content. The oxidation mechanisms at 1100 °C and 1400 °C were discussed by considering the effect of the C/SiC volume ratios, pores and matrix micro-cracks, oxidation of carbon phase and SiC.

Pests threaten worldwide food security by decreasing crop yields and damaging their quality. Natural product-based molecular design and structural optimization have been one of the most effective ways to innovate pesticides for integrated insect management. To continue our previous studies on the discovery of insecticidal lead, a series of evodiamine derivatives were designed, synthesized, and evaluated for their insecticidal activities. The bioassay results demonstrated that compounds Ianand Iaoexhibited 90 and 80% insecticidal activities against Mythimna separataat 2.5 mg/L, respectively, which were superior to evodiamine (10% at 10 mg/L), matrine (45% at 600 mg/L), and rotenone (30% at 200 mg/L). Compounds Ian–Iapshowed 90% insecticidal activities against Plutella xylostellaat 1.0 mg/L, far more potent than those of evodiamine, matrine, and rotenone. Compound Iandisplayed 60% insecticidal activity against Helicoverpa armigeraat 5.0 mg/L, while evodiamine, matrine, and rotenone showed very poor activities. The study on the insecticidal mechanism of action by a calcium imaging experiment indicated that the insect ryanodine receptors (RyRs) could be the potential target of Ian. Furthermore, the molecular docking indicated that Iananchored in the binding site of the RyR of P. xylostella. The above results manifested the potential of evodiamine derivatives as potent insecticide candidates.

• The PyC deposition kinetics and mechanism for E-CVI process were investigated by experimental and computational methods. • The E-CVI process exhibits very high PyC formation rates and very small apparent activation energy. • The electric current on the fibers can provide a concentric magnetic driving force to accelerate the motion of radicals and also help to reduce the energy barrier of dehydrogenation. • The small radicals with a high ratio of linear to aromatic may easily grow on the active sites to produce less ordered carbon. Although the electromagnetic-coupling chemical vapor infiltration (E-CVI) has been proven of a high-efficiency technique for producing carbon fiber reinforced pyrocarbon (PyC) matrix (C/C) composites, a deep understanding of the deposition kinetics and mechanism of PyC matrix is still lack. In this work, a deposition model with uniform electric field but gradient magnetic field was set up by using unidirectional carbon fiber bundles as the substrates to investigate the deposition kinetics and mechanism. Meanwhile, the polarizability, and the chemical adsorption and dehydrogenation barriers of hydrocarbon were simulated based on the density functional theory (DFT) and the Climb-image nudged elastic band method, respectively. The E-CVI process exhibited extremely high PyC deposition rates of 8.7, 11.5, 16.5 and 22.7 nm/s at 700, 750, 800 and 850 °C, respectively, together with a significantly low apparent activation energy of 57.9 kJ/mol within the first 5 min. The PyC deposited at different temperatures with different time shows a smooth laminar structure with low coherent length and graphitization degree. The theoretical calculation and simulation results indicated that the electrons existing on the carbon fibers and the accelerated motion of radicals with preferred orientation forced by the derived magnetic field have reduced the energy barrier for the deposition process, thereby resulting in low apparent activation energy and high PyC deposition rate. The results of this work may shed a light on how to better direct the preparation of C/C composites by E-CVI process with high quality and efficiency. [Display omitted] [ABSTRACT FROM AUTHOR]

A simple and sensitive method for the simultaneous determination of chito-oligosaccharides (COSs) with degrees of polymerization (DPs) from 2 to 7 was developed and used for COS quantification in rat plasma. Samples were separated on a Waters XBridge Amide column (3.5 μm, 2.1 × 150 mm) by isometric elution with 10 mM aqueous ammonium acetate (pH = 9) in acetonitrile and 10 mM aqueous ammonium acetate (pH = 9) (v/v, 50 : 50) employing multiple reaction monitoring (MRM) detection. Analytes and internal standards (IS) were extracted from rat plasma by protein precipitation with acetonitrile. The assay was linear over a concentration range of 20–10 000 ng mL−1for COS2–7. The intra-day and inter-day precision of the investigated components exhibited an RSD within 15%, and the accuracy (RE%) ranged from −7.3% to 7.6%. The extraction recoveries of the six constituents were determined to be between 82.5% and 94.3%. No significant matrix effects for COS2–7 were observed in rat plasma. COS in plasma remained stable for 24 h at room temperature (short-term), after freeze–thaw cycles, and 30 days in a −40 °C freezer. In comparison to reported COS quantitation methods, this method is simple, sensitive and cost-effective and could be used for the simultaneous quantitation of COS2–7. This method meets the Food and Drug Administration guidelines and had been successfully applied to the analysis of pharmacokinetic samples collected from rats.

As a complementary analysis tool to conventional high-field nuclear magnetic resonance (NMR), zero- to ultralow-field (ZULF) NMR detects nuclear magnetization signals in the sub-microtesla regime. Spin-exchange relaxation-free (SERF) atomic magnetometers provide a new generation of sensitive detectors for ZULF NMR. Owing to features such as low cost, high resolution, and portability, ZULF NMR has recently attracted considerable attention in chemistry, biology, medicine, and tests of fundamental physics. This review describes the basic principles, methodology, and recent experimental and theoretical development of ZULF NMR as well as its applications in spectroscopy, quantum control, imaging, NMR-based quantum devices, and tests of fundamental physics. The future prospects of ZULF NMR are also discussed.

A series of (R)-2-phenyl-4,5-dihydrothiazole-4-carboxamide derivatives containing a sulfur ether moiety were designed, synthesized, and tested for their antifungal activities against several phytopathogenic fungi. The established CoMSIA model could predict the antifungal activity.

Zero- and ultralow-field nuclear magnetic resonance (ZULF NMR) has experienced rapid development and provides an excellent tool for diverse research fields ranging from materials science and quantum information processing to fundamental physics. The detection of ZULF NMR signals in samples with natural abundance remains a challenging endeavor, due to the limited sensitivity of NMR detectors and thermal polarization. In this work, we demonstrate a femtotesla (fT) Potassium spin-exchange relaxation-free (SERF) magnetometer designed for ZULF NMR detection. A Potassium vapor cell with high buffer gas pressure and high atomic number density is used in the magnetometer. With absorption spectroscopy and SERF effect, the key parameters of the vapor cell are characterized and applied to optimize the magnetometer sensitivity. To combine our SERF magnetometer and ZULF NMR detection, a custom-made vacuum chamber is employed to keep NMR sample close to the magnetometer cell and protect the sample from undesired heating effects. Gradiometric measurement is performed to greatly reduce the magnetic noise. With the phase calibration applied, the gradiometric measurement achieves 7-fold enhancement in magnetic-field sensitivity compared to the single channel and has a magnetic noise floor of 1.2 fT/Hz1/2. Our SERF magnetometer exhibits high sensitivity and is promising to realize ZULF NMR detection of samples with natural abundance.

β-Conglycinin (7S) and glycinin (11S) are known to induce a variety of hypersensitivity reactions involving the skin, intestinal tract, and respiratory tract. The present study aimed to identify the mechanism underlying the development of allergy to soybean antigen proteins, using piglets as an animal model. Weaned “Duroc × Landrace × Yorkshire” piglets were fed a diet supplemented with 7S or 11S to investigate the signaling pathway involved in intestinal damage in piglets. Results showed that serum nitric oxide (NO), tumor necrosis factor-α (TNF-α), and caspase-3 levels were significantly higher in 7S- and 11S-fed piglets compared to those in suckling or weaned ones. mRNA, protein, and phosphorylation levels of nuclear factor-kappa B (NF-κB), p38, and Jun N-terminal kinase (JNK) were higher in 7S- and 11S-fed piglets than in suckling and weaned ones. Overall, our results indicate that 7S and 11S damaged the intestinal function in piglets through their impact on NF-κB, JNK, and p38 expression.

This study has developed a novel sensing platform for the investigation of cell oxygen metabolism. With chitosan@TiO2nanocomposites as supporting matrix which was decorated on the surface of indium tin oxide glass, it can effectively absorb A549 cells and sensitize the electrochemiluminescence (ECL) of luminol. On this platform, the ECL output is dependent on the level of reactive oxygen species (ROSs), which was evidenced by the intervening of resveratrol, a typical ROSs’ scavenger. The results indicated that the ECL signal was quenched by the resveratrol within its concentration range from 0.10 nM to 2.97 µM. Thus, it is believable that the ECL of luminol sensitively responded upon oxygenic matters on this living cell platform would be powerful for cell oxygen metabolism monitoring.

A fast segmentation algorithm of single medical image and sequence images based on active contour model are proposed in this paper. We give out the initial contour forecast segmentation model of 3D medical image first, and then, numerical solution of the image segmentation model algorithm is presented, send data blocks to different processors to do numerical calculations, finally combine the segmentation results. At the same time, parallel designing methods of node allocation, task allocation and load balancing methods are researched. The experiment results show that the parallel method can significantly improve the segmentation speed of 3D medical image.

Calcium-activated chloride conductance has been identified in normal pancreatic duct cells. Recent in vitro evidence suggests that angiotensin II (AngII) stimulates pancreatic secretion in both cystic fibrosis (CFPAC) and transformed pancreatic cells.

Exogenous insulin inhibits secretin-stimulated pancreatic bicarbonate output via a dose-dependent mechanism; this effect is prevented by pancreatic denervation.