1,383 research outputs found
Identifications of polyphenols and quantification of anthocyanidins in grapes and grape-derived products
No full textPolyphenols in grapes and grape-derived products have attracted public and scientific attention due to their numerous protective roles to human health. A rapid and comprehensive qualitative method was developed to characterize the different classes of polyphenols, such as anthocyanins, flavonols, phenolic acids and flavanols/proanthocyanidins, in grapes and grape-derived products. The detection was achieved by two runs with same HPLC gradient in different MS ionization modes and mobile phase modifiers (positive mode and 0.4% trifluoroacetic acid for anthocyanins and flavonols, negative mode and 0.1% formic acid for phenolic acids and flavanols). Under the optimized LC/MS conditions and based on the analysis of the MS and UV data and in comparison with the authenticated standards, a total of 53 polyphenolic compounds were successfully separated and individually identified including 33 anthocyanins, 12 flavonols, 4 phenolic acids and 4 flavanols/proanthocyanidins. With the method developed, a survey was conducted to qualitatively assess and compare the composition of polyphenols among 29 grapes and grape-derived products. To facilitate the quantitation of the major class of polyphenolic anthocyanidins, a simple and precise acid assisted hydrolysis method was established for the quantitation of anthocyanidins in grape juice samples, grape berries and grape skins using LC/MS. Five most common anthocyanidins of delphenidin, petunidin, cyanidin, malvidin, and peonidin in the hydrolyzed grape extracts were included in the quantification study. The validation of this method showed that the recovery percentages of five anthocyanidins ranged from 98.59 % to 103.20% with the relative standard deviation (RSD) less than 5.03%. The qualitative method provided complete insight into the composition of polyphenols in grapes, and other grape-derived products. This quantitative method provides a rapid and accurate tool to quantitatively study individual anthocyanidin in grapes or grape juice samples for quality control and to facilitate the evaluation and comparison of new commercial grapes or grape juice products in market.M.S.Includes bibliographical referencesby Yanping X
Comparative studies on OLED performances of chloro and fluor substituted Zn(II) 8-hydroxyquinolinates
No full textTwo novel 8-hydroxyquinoline metallic derivatives, (E)-2-[(2,3,4,5-tetrafluorophenyl)ethenyl]-8-hydroxyquinolate zinc (5) and (E)-2-[2-(2,6-dichlorophenyl]ethenyl]-8-hydroxyquinolate zinc (6) were synthesized and characterized by H-1 NMR, ESI-MS, FT-IR and elemental analysis. Photoluminescence spectra revealed that the complexes showed strong fluorescence with maximum emissions at 575 and 607 nm. Compared with that of complex 5, the fluorescence quantum yield and average fluorescence lifetime of complex 6 were efficiently reduced. The heavy atom effect of Cl and distinct molecular interactions were found to play an important role in modulating or improving the properties of the complexes. Multilayer organic light-emitting diodes (OLEDs) were fabricated using these complexes. The results show they are good candidates for yellow OLEDs with maximum luminance of 7123 cd m(-2) for compound 5 and 9143 cd m(-2) for compound 6, as well as luminance efficiencies of 2.26 cd A(-1) and 2.60 cd A(-1), respectively. As the substituents are changed from fluorine to chlorine, the organic electroluminescent device based on the complex 6 shows overall better performance than that of complex 5. The calculated HOMO-LUMO energy gaps for complexes 5 and 6 were in good agreement with the experimental results
Il mappamondo cinese di Giulio Aleni [Ai Rulüe] (Brescia, 1582 – Yanping 1649)
No full textI due fogli del mappamondo di Padre Giulio Aleni S.J., conservati a Roma nella Biblioteca Apostolica Vaticana, editi ed aggiornati a partire dal 1623, furono ispirati ed influenzati dal più famoso mappamondo di Padre Matteo Ricci, dato alle stampe, in diverse edizioni, successivamente alla fine del XVI secolo. Pur essendo successiva, l’edizione di Aleni costituisce un unicum al mondo essendo la prima mappa delle terre allora conosciute scritta in cinese e di dimensioni tali da permettere un’agevole consultazione. È una mappa che, fondendo assieme le conoscenze geografiche occidentali e cinesi, è relativamente fedele, pur con qualche eccezione, ai limiti reali dei continenti, rappresentati, come nel mappamondo di Matteo Ricci, da un punto di vista non eurocentrico
Multiscale asymptotic method for Steklov eigenvalue equations in composite media
No full textAuthor name used in this publication: Yanping Lin2012-2013 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishedVoR allowe
Developing finite element methods for maxwell's equations in a cole-cole dispersive medium
No full textAuthor name used in this publication: Yanping Lin2011-2012 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishedVoR allowe
Multiscale asymptotic method for Maxwell's equations in composite materials
No full textAuthor name used in this publication: Yanping Lin2009-2010 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishedVoR allowe
From Antibiotic Resistance to Bacterial Vaccines: A New Approach to Controlling Resistant Bacterial Infections
No full textFeiyang Xiong,1,2,* Xiayi Fang,1,* Yanping Lu,3 Wenliang Lv2 1Hunan University of Chinese Medicine, Changsha, Hunan, People’s Republic of China; 2Department of Infection, Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, People’s Republic of China; 3Department of Hepatology, Shenzhen Bao’an District Traditional Chinese Medicine Hospital, Shenzhen, People’s Republic of China*These authors contributed equally to this workCorrespondence: Yanping Lu, Department of Hepatology, Shenzhen Bao’an District Traditional Chinese Medicine Hospital, Shenzhen, People’s Republic of China, Tel +8613973195144, Email [email protected] Wenliang Lv, Department of Infection, Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, People’s Republic of China, Tel +8619267490697, Email [email protected]: Antimicrobial resistance (AMR) is one of the major threats to global health, with a complex and diverse underlying mechanism. Vaccines reduce the dependence on antimicrobial agents by preventing and treating bacterial and viral infections, as well as secondary infections caused by both, thereby lowering the risk of AMR. Unlike traditional antibiotics, bacterial vaccines trigger a long-lasting immune response that not only prevents bacterial infections but also inhibits the spread of resistant strains. They show significant advantages in reducing antibiotic use and lowering resistance risks. However, the development of bacterial vaccines faces several challenges, including the diversity of bacterial antigens, rapid evolution, and the difficulty of achieving broad-spectrum immune protection. Despite these challenges, advancements in vaccine technology and the optimization of delivery systems are making the application prospects of bacterial vaccines in combating resistant strains increasingly promising. We sequentially discuss resistance mechanisms, existing and emerging vaccine platforms, enabling technologies, and future perspectives.Keywords: antimicrobial resistance, bacterial vaccines, bacterial infections, challenges, technolog
Visite du prince héritier Hirohito sur Yanping lu en 1923
No full textEn 1923, le prince héritier Hirohito du Japon partit en tournée à Taïwan, qui était la première visite impériale, en tant que représentant de l'empereur japonais, pour inspecter les colonies japonaises ((En 1895, lors de la Guerre sino-japonaise (1894-1895), les Qing cèdent Taïwan à l'Empire du Japon, le 17 avril 1895. Lors de la défaite de 1945, le Japon remet Taïwan à l'ONU, qui en confie l'île à la République de Chine)). Cette visite a été un événement majeur à Taïwan. L'île connaît alors ..
Visite du prince héritier Hirohito sur Yanping lu en 1923
No full textEn 1923, le prince héritier Hirohito du Japon partit en tournée à Taïwan, qui était la première visite impériale, en tant que représentant de l'empereur japonais, pour inspecter les colonies japonaises ((En 1895, lors de la Guerre sino-japonaise (1894-1895), les Qing cèdent Taïwan à l'Empire du Japon, le 17 avril 1895. Lors de la défaite de 1945, le Japon remet Taïwan à l'ONU, qui en confie l'île à la République de Chine)). Cette visite a été un événement majeur à Taïwan. L'île connaît alors ..
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