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971.
A new chemosensor, namely N-(2-morpholinoethyl)acetamide-4-morpholine-1,8-naphthimide (MMN), was designed and synthesized through an amidation reaction. MMN was fabricated as a multifunctional fluorescent probe for monitoring pH and isoxaflutole. MMN exhibited excellent stability in MeCN/H2O (v/v, 9/1), with an obvious “off–on” fluorescence response toward pH changes due to intramolecular charge transfer (ICT), where the linear response ranges of MMN in the weakly acidic system were from 4.2 to 5.0 and from 5.0 to 6.0 with apparent pKa = 4.62 ± 0.02 and 5.43 ± 0.02. Based on morpholine as the lysosome targetable unit, MMN could selectively locate lysosomes in live cells. MMN also successfully detected the presence of H+ in test papers. Finally, MMN could specifically recognize isoxaflutole at a detection limit of 0.88 μM. A possible sensing mechanism was identified based on density function theory calculations. These results indicate that MMN could be a superior potential chemosensor for detecting pH and isoxaflutole selectively and sensitively and could be used in real sample detection.  相似文献   
972.
973.
974.
为探究不同酯化度(DE)果胶形成的果胶钙的结构特征与消化稳定性,采用5种DE值的果胶与氯化钙反应获得5种DE的果胶钙,比较其产率、钙含量,红外、X衍射(XRD)、电镜(SEM)等结构特征与体外模拟消化稳定性。结果表明:果胶钙产率为50%~87%;DE=10%的果胶与Ca2+反应形成的果胶钙(DE10-CaP)的钙含量最高(88 mg/g),DE59-CaP钙含量最低(43.6 mg/g);果胶钙中Ca2+与羧酸根的结合形式为单齿配位结合型,并可分为3种结合区域,进一步完善了果胶钙的结合模式;XRD表明低酯果胶钙比高酯果胶钙多一处2θ=21.5°的衍射峰;SEM表明低酯果胶钙的表观结构更紧密,呈块状,高酯果胶钙则呈薄片状。体外模拟胃肠消化试验表明,高酯果胶钙的钙释放率及释放量更高。本研究有助于了解果胶钙的微观结构及应用性能。  相似文献   
975.
为了解决可拉伸应变传感器的灵敏度与检测范围(最大和最小可拉伸性)之间相互制约的问题.受蛋类膜-壳结构的启发,本文提出了一种构筑具有高灵敏度、宽可拉伸应变传感器的新策略,即基于柔性可拉伸的表面接枝聚吡咯膜(s-PPy)(类似于蛋膜)和脆性金膜(类似于蛋壳)制备器件.Au和s-PPy膜在电学和机械性能上产生相互协同作用.A...  相似文献   
976.
Red blood cell-derived extracellular vesicles (RBCEVs) are vesicles naturally produced by red blood cells and play multiple roles such as acting as cell-to-cell communication messengers in both normal physiological and diseased states. RBCEVs are highly promising delivery vehicles for therapeutic agents such as biomolecules and nucleic acids as they are easy to source, safe, and versatile. RBCEVs autonomously target the liver and pass the blood–brain barrier into the brain, which is highly valuable for the treatment of liver and brain diseases. RBCEVs can be modified by various functional units, including various functional molecules and nanoparticles, to improve their active targeting capabilities for tumors or other sites. Moreover, the RBCEV level is significantly shifted in many diseased states; hence, they can also serve as important biomarkers for disease diagnoses. It is clear that RBCEVs have considerable potential in multiple medical applications. In this review, we briefly introduce the biological roles of RBCEVs, presented interesting advances in RBCEV applications, and discuss several challenges that need to be addressed for their clinical translation.  相似文献   
977.
Plants have evolved a sophisticated defense system that employs various hormone pathways to defend against attacks by insect pests. Cytokinin (CK) plays an important role in plant growth and stress tolerance, but the role of CKs in plant–insect interaction remains largely unclear. Here, we report that CKs act as a positive regulator in rice resistance against brown planthopper (BPH), a devastating insect pest of rice. We found that BPH feeding promotes CK biosynthesis and signaling in rice. Exogenous application of CKs significantly increased the rice resistance to BPH. Increasing endogenous CKs by knocking out cytokinin oxidase/dehydrogenase (OsCKXs) led to enhanced resistance to BPH. Moreover, the levels of the plant hormone jasmonic acid (JA) and the expression of JA-responsive genes were elevated by CK treatment and in OsCKXs knockout plants. Furthermore, JA-deficient mutant og1 was more susceptible to BPH, and CK-induced BPH resistance was suppressed in og1. These results indicate that CK-mediated BPH resistance is JA-dependent. Our findings provide the direct evidence for the novel role of CK in promoting insect resistance, and demonstrate that CK-induced insect resistance is JA-dependent. These results provide important guidance for effective pest management strategies in the future.  相似文献   
978.
采用MATLAB图像处理技术在鱼病诊断中的应用   总被引:1,自引:0,他引:1  
本文介绍了一种可以对水产养殖中鱼的病变情况进行监控的系统。通过MATLAB软件中强大的图像处理功能,对读入的图像进行中值滤波、灰度处理和二值处理,然后根据收缩与扩张的原理,编写程序,对二值图像进行数次收缩与扩张,以去除杂质点,最后采用区域矩特征的概念,统计出白色像素的数目,与统计数据相比较,即可判断出是否出现鱼类病变死亡等异常情况。  相似文献   
979.
Tomographic perfusion imaging is a significant imaging modality for stroke diagnosis.However,the low rotational speed of the C-arm(6-8 s per circle)is a chal-le...  相似文献   
980.
Ti3C2Tx,which is a novel two-dimensional (2D)material,has received enormous interest in the field of sensor technology due to its large surface area,excellent e...  相似文献   
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