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1.
Nano Lett ; 23(19): 9034-9041, 2023 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-37728246

RESUMEN

The highly reflective solar radiation of passive daytime radiative cooling (PDRC) increases heating energy consumption in the cold winter. Inspired by the temperature-adaptive skin color of chameleon, we efficiently combine temperature-adaptive solar absorption and PDRC technology to achieve "warm in winter and cool in summer". The temperature-adaptive radiative cooling coating (TARCC) with color variability is designed and fabricated, achieving 41% visible light regulation capability. Comprehensive seasonal outdoor tests confirm the reliability of the TARCC: in summer, the TARCC exhibits high solar reflectance (∼93%) and atmospheric transmission window emittance (∼94%), resulting in a 6.5 K subambient temperature. In the winter, the TARCC's dark color strongly absorbs solar radiation, resulting in a 4.3 K temperature rise. Compared with PDRC coatings, the TARCC can save up to 20% of annual energy in midlatitude regions and increase suitable human hours by 55%. With its low cost, easy preparation, and simple construction, the TARCC shows promise for achieving sustainable and comfortable indoor environments.

2.
Acta Pharmacol Sin ; 39(5): 875-884, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29595193

RESUMEN

Xyloketal B (Xyl-B) is a novel marine compound isolated from mangrove fungus Xylaria sp. (No 2508). We previously showed that Xyl-B promoted endothelial NO release and protected against atherosclerosis through the Akt/eNOS pathway. Vascular NO production regulates vasoconstriction in central and peripheral arteries and plays an important role in blood pressure control. In this study, we examined whether Xyl-B exerted an antihypertensive effect in a hypertensive rat model, and further explored the possible mechanisms underlying its antihypertensive action. Administration of Xyl-B (20 mg·kg-1·d-1, ip, for 12 weeks) significantly decreased the systolic and diastolic blood pressure in a two-kidney, two-clip (2K2C) renovascular hypertensive rats. In endothelium-intact and endothelium-denuded thoracic aortic rings, pretreatment with Xyl-B (20 µmol/L) significantly suppressed phenylephrine (Phe)-induced contractions, suggesting that its vasorelaxant effect was attributed to both endothelial-dependent and endothelial-independent mechanisms. We used SNP, methylene blue (MB, guanylate cyclase inhibitor) and indomethacin (IMC, cyclooxygenase inhibitor) to examine which endothelial pathway was involved, and found that MB, but not IMC, reversed the inhibitory effects of Xyl-B on Phe-induced vasocontraction. Moreover, Xyl-B increased the endothelial NO bioactivity and smooth muscle cGMP level, revealing that the NO-sGC-cGMP pathway, rather than PGI2, mediated the anti-hypertensive effect of Xyl-B. We further showed that Xyl-B significantly attenuated KCl-induced Ca2+ entry in smooth muscle cells in vitro, which was supposed to be mediated by voltage-dependent Ca2+ channels (VDCCs), and reduced ryanodine-induced aortic contractions, which may be associated with store-operated Ca2+ entry (SOCE). Taken together, these findings demonstrate that Xyl-B exerts significant antihypertensive effects not only through the endothelial NO-sGC-cGMP pathway but also through smooth muscle calcium signaling, including VDCCs and SOCE.


Asunto(s)
Antihipertensivos/uso terapéutico , Señalización del Calcio/efectos de los fármacos , Hipertensión Renovascular/tratamiento farmacológico , Piranos/uso terapéutico , Transducción de Señal/efectos de los fármacos , Animales , Calcio/metabolismo , GMP Cíclico/metabolismo , Células Endoteliales de la Vena Umbilical Humana , Humanos , Masculino , Azul de Metileno/farmacología , Músculo Liso Vascular/efectos de los fármacos , Miocitos del Músculo Liso/efectos de los fármacos , Óxido Nítrico Sintasa de Tipo III/metabolismo , Ratas Sprague-Dawley , Guanilil Ciclasa Soluble/metabolismo , Vasodilatadores/uso terapéutico
3.
Light Sci Appl ; 13(1): 202, 2024 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-39168994

RESUMEN

Thermochromic hydrogels exhibit a smart capacity for regulating solar spectrum transmission, enabling automatically change their transmissivity in response to the ambient temperature change. This has great importance for energy conservation purposes. Military and civilian emergency thermochromic applications require rapid visible-light stealth (VLS); however, concurrent smart solar transmission and rapid VLS is yet to be realized. Inspired by squid-skin, we propose a micropatterned thermochromic hydrogel (MTH) to realize the concurrent control of smart solar transmittance and rapid VLS at all-working temperatures. The MTH possesses two optical regulation mechanisms: optical property regulation and optical scattering, controlled by temperature and pressure, respectively. The introduced surface micropattern strategy can arbitrarily switch between normal and diffuse transmission, and the VLS response time is within 1 s compared with previous ~180 s. The MTH also has a high solar-transmission regulation range of 61%. Further, the MTH preparation method is scalable and cost-effective. This novel regulation mechanism opens a new pathway towards applications with multifunctional optical requirements.

4.
Biochem Pharmacol ; 78(8): 941-50, 2009 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-19481065

RESUMEN

Xyloketal B is a novel marine compound with unique chemical structure isolated from mangrove fungus Xylaria sp. (no. 2508). Pretreatment with xyloketal B (0.63-40 microM) significantly improved oxLDL (150 microg/ml)-induced injury in human umbilical vein endothelial cells (HUVECs) without either toxic or proliferative effects. Xyloketal B concentration-dependently attenuated oxLDL-induced ROS generation, peroxynitrite formation and decrease of Bcl-2 expression. In addition, xyloketal B significantly inhibited NADPH oxidase activity, as well as mRNA expression of gp91phox and p47phox. Furthermore, xyloketal B alone augmented the production of nitric oxide (NO). Collectively, these data indicate that xyloketal B protects against oxLDL-induced endothelial oxidative injury probably through inhibiting NADPH oxidase-derived ROS generation, promoting NO production and restoring Bcl-2 expression, making it a promising compound for further evaluation in the treatment of atherosclerosis.


Asunto(s)
Células Endoteliales/efectos de los fármacos , Endotelio Vascular/efectos de los fármacos , Lipoproteínas LDL/farmacología , Piranos/farmacología , Venas Umbilicales/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Relación Dosis-Respuesta a Droga , Células Endoteliales/metabolismo , Endotelio Vascular/metabolismo , Endotelio Vascular/patología , Fluoresceínas/metabolismo , Colorantes Fluorescentes/metabolismo , Formazáns/análisis , Humanos , Indoles/metabolismo , Estructura Molecular , NADPH Oxidasas/biosíntesis , Óxido Nítrico/biosíntesis , Oxidación-Reducción , Ácido Peroxinitroso/biosíntesis , Piranos/química , Piranos/aislamiento & purificación , Especies Reactivas de Oxígeno/análisis , Especies Reactivas de Oxígeno/metabolismo , Sales de Tetrazolio/análisis , Factores de Tiempo , Tirosina/análogos & derivados , Tirosina/metabolismo , Venas Umbilicales/metabolismo , Xylariales/química
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