Nickel doped Nano Cobalt (II) Oxide used as Photocatalyst for Degradation of Evans Blue Dye

The photocatalytic degradation of Evans blue (EB) has been studied under visible light in the presence of nanocrystalline nickel doped cobalt (II) oxide as a photocatalyst. Nickel-cobalt (II) oxide was synthesized by using Sol-gel technique. The photocatalyst was characterized by Field Emission Scanning Electron Microscopy (FESEM), Energy-dispersive X-ray spectroscopy (EDX), X-ray Diffraction (XRD), Fourier-transform infrared (FTIR) and High-resolution transmission electron microscopy (HRTEM). Effect of various working parameters like pH, concentration, amount of nickel doped and undoped cobalt (II) oxide, dose of dopants, light intensity etc. on the rate of degradation of Evans blue was also investigated. On the basis of observations, a suitable mechanism for the photocatalytic degradation of Evans blue dye has been proposed.

Hypercapnia and its combination with hypoxia decrease the permeability of the blood-brain barrier in rats

Цель исследования - оценка проницаемости ГЭБ после сочетанного воздействия гиперкапнии и гипоксии. Методика. Исследования проведены на 40 крысах-самцах Wistar рандомизированых на 4 равные группы (n=10): нормобарическая гипоксия (PO2 - 90 мм рт. ст./13%; PCO2 - 1 мм рт. ст./0,1%); пермиссивная гиперкапния (PO2 - 150 мм рт. ст./21%; PСO2 - 50 мм рт. ст./7%); гиперкапническая гипоксия (PO2 - 90 мм рт. ст./13%; PCO2 - 50 мм рт. ст./7%); контрольная группа (PO2 - 150 мм рт. ст./21%; PCO2 - 1 мм рт. ст./0,1%). Респираторные воздействия проводили в специальной камере в течение 15 сут по 30 мин ежедневно. Газовую смесь подавали в камеру компрессором со скоростью 15 л/мин. Контроль газового состава в камере проводили газоанализатором Microlux (Микролюкс, Россия). Через 24 ч после завершения курсов респираторных воздействий животным внутрибрюшинно вводили 2%-й раствор красителя Evans blue в объеме 4 мл/кг массы животного. Оценку проницаемости ГЭБ осуществляли через 24 ч после введения красителя путем фотометрического измерения его содержания в плазме крови и флуоресцентной микроскопии ткани головного мозга. Анализ интенсивности флуоресценции Evans blue в ткани головного мозга проводился на конфокальном микроскопе FV10i-W (Olympus, Япония). Определяли флуоресцентную интегративную оптическую плотность Evans blue с последующим расчетом индекса проницаемости по концентрации красителя в крови. Определение содержания красителя в крови осуществляли фотометрически (при 610 нм) с использованием планшетного фотометра Multiscan FS (Thermo scientific, США) по калибровочным кривым. Результаты. Индекс проницаемости ГЭБ (содержание в мозге/концентрация в крови) был существенно ниже в группах, которые подвергались респираторным воздействиям с наличием гиперкапнического компонента. Заключение. Интермиттирующая гиперкапническая гипоксия формирует наименьший уровень проницаемости ГЭБ по сравнению с изолированным воздействием гипоксии или гиперкапнии. The aim of study was to evaluate the blood-brain barrier (BBB) permeability after a combined treatment with hypercapnia and hypoxia. Methods. Experiments were performed on 40 Wistar male rats randomized to 4 equal groups (n=10): normobaric hypoxia (PO2 = 90 mm Hg/13%/PCO2 = 1 mm Hg/0.1% CO2,), permissive hypercapnia (PO2 = 150 mm Hg/21%; PCO2 = 50 mm Hg/7%); hypercapnic hypoxia (PO2 = 90 mm Hg/13%, PCO2 = 50 mm Hg/7%); and a control group (PO2 - 150 mm Hg/21%; PCO2 - 1 mm Hg/0.1%) in a special chamber for 15 days, 30 min daily. The gas mixture was delivered to the chamber with a compressor at 15 l/min. Gas composition was monitored with a gas analyzer (Microlux, Russia). At 24 hrs after completion of respiratory exposures, Evans blue dye was administered i.p. (4 ml/kg body weight). BBB permeability was assessed from the content of Evans blue dye in blood plasma photometrically and in brain tissue by fluorescent microscopy. Evans blue fluorescence intensity in brain tissue was analyzed with a confocal microscope FV10i-W (Olympus, Japan). Fluorescent integrative optical density of Evans blue was determined and used for calculation of the permeability index from blood concentration of the dye. Blood concentration of the dye was measured photometrically (at 610 nm) with a plate photometer Multiscan FS (Thermo Scientific, USA) using calibration curves. Results. The BBB permeability index (content of Evans blue dye in the brain / concentration of Evans blue dye in blood) was significantly lower in the groups that underwent respiratory exposures with the presence of a hypercapnic component. Conclusion. Intermittent hypercapnic hypoxia yields the lowest BBB permeability compared to the isolated effect of either hypoxia or hypercapnia.

Injection of Evans blue dye to fluorescently label and image intact vasculature

Blood vessels perform critical functions in both health and disease. Understanding how vessels form, pattern and respond to damage is essential. However, labeling and imaging the vasculature to ascertain these properties can be difficult and time-consuming. Here, the authors present a novel methodology for rapidly and efficiently labeling whole vascular networks in vivo by exploiting the fluorescent properties of Evans blue. By combining the labeling with fluorescence microscopy, this method enables visualization of whole tissue vasculature for a fraction of the time and cost compared with traditional methods.

Sustained laryngeal transient receptor potential vanilloid 1 activation inhibits mechanically induced swallowing in anesthetized rats

Although a transient receptor potential vanilloid 1 (TRPV1) inhibitor or TRPV1-expressed neuronal inhibitor significantly inhibited HCl/capsaicin-evoked swallowing, air flow-induced swallowing was not affected. The number of air flow-induced swallows was significantly reduced within 60 min of TRPV1 activation. Evans blue dye concentration in the larynx increased 60 min after capsaicin application. TPRV1 activation not only desensitizes TRPV1 but also inactivates mechanoreceptors caused by increases in vascular permeability and edema.