Four new cyclohexapeptides,pyridapeptides F–I(1–4),were isolated from the fermentation broth of marine sponge-derived Streptomyces sp.OUCMDZ-4539.The pyridapeptides F–H(1–3)are composed ofβ-hydroxyleucine,alanine...Four new cyclohexapeptides,pyridapeptides F–I(1–4),were isolated from the fermentation broth of marine sponge-derived Streptomyces sp.OUCMDZ-4539.The pyridapeptides F–H(1–3)are composed ofβ-hydroxyleucine,alanine,O-methylthreonine,hexahydropyridazine-3-carboxylic acid,5-hydroxytetrahydropyridazine-3-carboxylic acid,and(2S,3R,4E,6E)-2-amino-3–hydroxy-4,6-dienoic acid residues.Pyridapeptide I(4)contains(2S,3R,4E,6E)-2-amino-3–hydroxy-8-methylnona-4,6-dienoic acid residue and a very rare glycose residue,aculose.Their structures were determined based on spectroscopic analysis and chemical methods.Pyridapeptides G–I(2–4)have the 2,3,6-trideoxyhexose units glycosylated at theγ-OH-TPDA residue,displayed significant antiproliferative activity against four(PC9,MKN45,Hep G2,K562)or two(PC9,MKN45)human cancer cell lines.展开更多
Imaging through non-static and optically thick scattering media such as dense fog,heavy smoke,and turbid water is crucial in various applications.However,most existing methods rely on either active and coherent light ...Imaging through non-static and optically thick scattering media such as dense fog,heavy smoke,and turbid water is crucial in various applications.However,most existing methods rely on either active and coherent light illumination,or image priors,preventing their application in situations where only passive illumination is possible.In this study we present a universal passive method for imaging through dense scattering media that does not depend on any prior information.Combining the selection of small-angle components out of the incoming information-carrying scattering light and image enhancement algorithm that incorporates timedomain minimum filtering and denoising,we show that the proposed method can dramatically improve the signal-to-interference ratio and contrast of the raw camera image in outfield experiments.展开更多
基金financially supported by the National Natural Science Foundation of China(No.U1906213)the National Key Research and Development Program of China(No.2022YFC2804100)。
文摘Four new cyclohexapeptides,pyridapeptides F–I(1–4),were isolated from the fermentation broth of marine sponge-derived Streptomyces sp.OUCMDZ-4539.The pyridapeptides F–H(1–3)are composed ofβ-hydroxyleucine,alanine,O-methylthreonine,hexahydropyridazine-3-carboxylic acid,5-hydroxytetrahydropyridazine-3-carboxylic acid,and(2S,3R,4E,6E)-2-amino-3–hydroxy-4,6-dienoic acid residues.Pyridapeptide I(4)contains(2S,3R,4E,6E)-2-amino-3–hydroxy-8-methylnona-4,6-dienoic acid residue and a very rare glycose residue,aculose.Their structures were determined based on spectroscopic analysis and chemical methods.Pyridapeptides G–I(2–4)have the 2,3,6-trideoxyhexose units glycosylated at theγ-OH-TPDA residue,displayed significant antiproliferative activity against four(PC9,MKN45,Hep G2,K562)or two(PC9,MKN45)human cancer cell lines.
基金National Natural Science Foundation of China(62325508,62061136005,61991452,U22A2080)Program of Shanghai Academic Research Leader(22XD1403900)+1 种基金Shanghai Municipal Science and Technology Major ProjectShanghai Yangfan Program(23YF1454200)。
文摘Imaging through non-static and optically thick scattering media such as dense fog,heavy smoke,and turbid water is crucial in various applications.However,most existing methods rely on either active and coherent light illumination,or image priors,preventing their application in situations where only passive illumination is possible.In this study we present a universal passive method for imaging through dense scattering media that does not depend on any prior information.Combining the selection of small-angle components out of the incoming information-carrying scattering light and image enhancement algorithm that incorporates timedomain minimum filtering and denoising,we show that the proposed method can dramatically improve the signal-to-interference ratio and contrast of the raw camera image in outfield experiments.
