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Polyphagous insects could affect agricultural production, which leads to serious economic losses. Due to the negative effects of synthesized insecticides, finding eco-friendly and new biopesticides is emergent. To develop natural origin insecticides, an integrative approach combining antifeedant activity screening, genome mining, and molecular networking has been applied to discover antifeedant secondary metabolites from Streptomyces sp. NA13, which leads to the isolation of a novel antimycin Q ( 1 ) and six known antimycin analogs (antimycins A1a, A2a, A3a, A4a, A7a, and N-formylantimycic acid methyl ester, 2 – 7 ). Their structures were identified by high-resolution mass spectrometry (HR-MS) and nuclear magnetic resonance (NMR) spectroscopic. The absolute configuration of 1 was elucidated by the comparison of coupling constant, electronic circular dichroism (ECD) analysis, and NMR calculations. 1 – 6 exhibited different levels of antifeedant activities against Helicoverpa armigera, especially 1– 4 . At the same time, the antifeedant activity of antimycin was reported firstly.  相似文献   
403.
Yu  Can  Lei  Zhao  Li  Xia  Huang  Li-Hua  Li  Zhi-Qiang  Zhu  Hong-Wei  Han  Duo  Huang  Hui  Yu  Xiao 《Biochemical genetics》2022,60(2):598-610
Biochemical Genetics - The present study established a necroptosis model in vitro and investigated the role of HMGB1 in cell necroptosis. A combination of tumor necrosis factor-α and z-VAD-fmk...  相似文献   
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This study aimed at visualizing relative relaxation time constant (RTC) in soft tissue by using optical coherence elastography (OCE). We proposed a forced vibration model as a theoretical base to express RTC using axial gradient of periodic vibration phase captured by phase sensitive optical coherence tomography (PhS‐OCT). Validation of the model had been accomplished by experiments with isotropic and double‐layered phantoms. A fresh chicken breast sample treated with focused ultrasound was prepared to test performance of the RTC‐OCE in real tissue. All results were cross‐validated with indentation test and traditional strain‐based elastography. This study first utilized RTC mapping in 2D and 3D that covers the information of both elasticity and viscosity. The generated RTC mapping revealed the same mechanical difference internal sample which is correlated with conventional strain mapping. RTC mapping is potentially to be served as new biomarker for disease diagnosis in the future.  相似文献   
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正High carbohydrate(CHO)intake was associated with higher risk of total mortality,whereas high intake of total fat and individual types of fat were related to lower total mortality.Total fat and types of fat were not associated with cardiovascular disease,myocardial infarction,or cardiovascu-  相似文献   
407.
The oxygen evolution reaction (OER) is a bottleneck process for water splitting and finding highly efficient, durable, low‐cost, and earth‐abundant electrocatalysts is still a major challenge. Here a sulfur‐treated Fe‐based metal–organic‐framework is reported as a promising electrocatalyst for the OER, which shows a low overpotential of 218 mV at the current density of 10 mA cm?2 and exhibits a very low Tafel slope of 36.2 mV dec?1 at room temperature. It can work on high current densities of 500 and 1000 mA cm?2 at low overpotentials of 298 and 330 mV, respectively, by keeping 97% of its initial activity after 100 h. Notably, it can achieve 1000 mA cm?2 at 296 mV with a good stability at 50 °C, fully fitting the requirements for large‐scale industrial water electrolysis. The high catalytic performance can be attributed to the thermocatalytic processes of H+ capture by –SO3 groups from *OH or *OOH species, which cascades to the electrocatalytic pathway and then significantly reduces the OER overpotentials.  相似文献   
408.
The objective of this study is to examine the change in macrophage numbers, inducible form of NO synthase (iNOS), and vascular endothelial growth factor (VEGF) expression both before and after embryo implantation in the uterine tissue of mice. In order to explore the mechanism of macrophages in endometrial angiogenesis, 8-week-old female mice were divided into three groups: pregnant group, pseudopregnant group (mated to male mice that had been vasectomized), and estrous group (unmated). Individuals from these three groups were sacrificed at time intervals D1.5 to D6.5. Formalin-fixed paraffin-embedded tissue was used for immunocytochemical localization of Mφ, iNOS, and VEGF utilizing standard methodology. The proportion of macrophages in the peripheral blood was determined by flow cytometry, and the relationship between macrophage, iNOS, and VEGF expression was analyzed. The proportion of peripheral blood macrophages in the pregnancy group was significantly higher than that in the other groups. The results of immunohistochemistry determined that the macrophages exhibited changes in both numbers and distribution. The number of macrophages in the endometrium of the pregnancy and pseudopregnancy groups was significantly higher than that in the control (estrous) group. In the pregnancy group, macrophage numbers dramatically decreased and gradually transferred to the perimetrium on D4.5. Immunostaining revealed strong staining in the pregnancy group and weaker staining in the pseudopregnant and control groups for both iNOS and VEGF. There was strong, dense immunostaining at the implantation site for both iNOS and VEGF, whereas light immunostaining was seen in interimplantation tissues on D5.5 to D6.5. In the pregnant group, peripheral blood and uterine macrophage proportions were negatively correlated, whereas the amount of macrophages, iNOS, and VEGF expression in the endometrium were positively correlated. The expression of iNOS and VEGF in the endometrium also displayed a strong positive correlation. In conclusion, during embryo implantation, macrophages levels decreased in the uterus, whereas the number of peripheral macrophages increased, suggesting that macrophages may migrate into the peripheral blood and uterus to adapt for pregnancy. Additionally, an increase in the expression of iNOS and VEGF was observed during the implantation window, implying that iNOS and VEGF may play an important role in promoting embryo implantation. The positive correlation between macrophages, iNOS, and VEGF in the implanting uterus implied that macrophages might regulate iNOS and VEGF during the implantation process.  相似文献   
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