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Tracking and quantifying hypochlorite (ClO - ) in biological systems and environments remain challenging tasks, and many efforts have been made to improve ClO - recognition performance by modifying the sensor structure. In this study, a pre-designed coumarin/furanohydrazide-based sensor (CMFH) with the coumarin moiety as the building block (fluorogen) was rationally prepared as a ratiometric and colorimetric chemosensor for ClO - recognition. As expected, CMFH demonstrated excellent sensitivity and selectivity for ClO - detection. The fluorescence signal ratio (F 466 /F 556 ) showed strong ClO - dependency, and the sensor exhibited ultrafast detection (within 60 s) and a low detection limit of 563 nM. Due to its low cytotoxicity and good tissue permeability, CMFH was demonstrated as a dual-channel sensor for ClO - bioimaging and visualization in cells, zebrafish, and even bacteria. Furthermore, CMFH-loaded paper strips were successfully applied to the colorimetric and fluorescent visualization of ClO - . The results demonstrate that CMFH has potential application value for tracking ClO - in various biosystems and environments., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Acid-alkaline balance plays a crucial role in all biological processes. Accordingly, monitoring pH changes will help us to understand the functional status of these physiological and pathological processes. Though fluorescent probes may be a useful tool for detecting pH changes, and there are many limitations to currently available probes, such as background interference, potential cytotoxicity, and poor cell permeability, which call for a solution urgently. In this work, a rhodamine-derived colorimetric and ratiometric sensor (Rh-HN) was fabricated for monitoring pH change via the mechanism of fluorescence resonance energy transfer (FRET). Rh-HN has been shown to possess several advantages over other probes, such as high sensitivity, outstanding permeability, and low toxicity. Besides, the fluorescence intensity ratio (F 526 /F 592 ) of Rh-HN displays a pH-sensitive response from 2.0 to 7.5 (pKa = 5.05) and linear response from pH 3.8 to 6.4, which was desirable for mapping pH change in the biological systems. Besides, the results indicated that Rh-HN generated a pH-dependent response regulated by switchable forms between closed and opened spirolactam ring. Overall, Rh-HN has accomplished sensing and mapping of pH in living cells, bacteria, and zebrafish. Those results demonstrated that the great potential of Rh-HN in sensing and visualizing pH in the living biosystem., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Hypochlorous acid (HOCl)/hypochlorite (ClO - ) was a biologically important component of reactive oxygen species (ROS) and plays a key role in human immune function systems. HOCl/ClO - can destroy invasive bacteria and pathogens, and mediate the physiological balance of the organism with low concentrations, and cause oxidation of the biomolecules such as proteins, cholesterol and nucleic acid in biological cells, leading to a series of diseases with over capacity. Therefore, quantifying the content of HOCl/ClO - in organisms are extremely urgent. In this work, coumarin-salicylic hydrazide Schiff base (CMSH), a ratiometric and colorimetric fluorescent probe for ClO- detection based on coumarin as the fluorophore unit was rationally designed and synthesized. The results indicated that CMSH exhibits high selectivity and sensitivity for ClO- identification. Additionally, the ratios (I 470 /I 532 ) displayed brilliant ClO - -dependent quick and sensitive performance within 40 s and limitation of 128 nM, respectively. As well as the color of the solution changes from green to colorless accompanied by the fluorescence form green turns into blue with addition of ClO - . Totally, CMSH has been successfully employed as ratiometric sensor to image in living cells, bacteria and zebrafish with low cytotoxicity and good permeability., (Copyright © 2020 Elsevier B.V. All rights reserved.)

To understand the differences in metabolic changes between cows with ovarian inactivity and estrus cows, we selected cows at 60-90 days postpartum from an intensive dairy farm. According to clinical manifestations, B-ultrasound scan, rectal examination, 10 cows were assigned to the estrus group (A) and 10 to the ovarian inactivity group (B). All plasma samples were analyzed by (1)H-nuclear magnetic resonance spectroscopy to compare plasma metabolomic profiles between the groups. We used multivariate pattern recognition to screen for different metabolites in plasma of anestrus cows. Compared with normal estrous cows, there were abnormalities in 12 kinds of metabolites in postpartum cows with ovarian inactivity (|r|> 0.602), including an increase in acetic acid (r = -0.817), citric acid (r = -0.767), and tyrosine (r = -0.714), and a decrease in low-density lipoprotein (r = 0.820), very low-density lipoprotein (r = 0.828), lipids (r = 0.769), alanine (r = 0.816), pyruvate (r = 0.721), creatine (r = 0.801), choline (r = 0.639), phosphorylcholine (r = 0.741), and glycerophosphorylcholine (r = 0.881). These metabolites were closely related to abnormality of glucose, amino acid, lipoprotein and choline metabolism, which may disturb the normal estrus. The decrease in plasma creatine and the increase in tyrosine were new changes for ovarian inactivity of postpartum cows. The decrease in plasma creatine and choline and the increase in tyrosine and p-hydroxyphenylalanine in cows with ovarian inactivity provide new directions for research on the mechanism of ovarian inactivity in cows., (Copyright © 2016 Elsevier Inc. All rights reserved.)