117 research outputs found

    Visualization of Nd3+-doped Laf3 Nanoparticles For Near Infrared Bioimaging via Upconversion Luminescence at Multiphoton Excitation Microscopyvisualization of Nd3+-doped Laf3 Nanoparticles For Near Infrared Bioimaging via Upconversion Luminescence at Multiphoton Excitation Microscopy

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    Recent developments in the field of biophotonics facilitate the raise of interest to inorganic nanoparticles (NPs) doped with Nd 3+ ions, because of their near-infrared (NIR) absorption. These NPs are interesting bioimaging probes for deep tissue visualization, while they can also act as local thermometers in biological tissues. Despite the good possibilities for visualization of NPs with Nd 3+ ions in NIR spectral range, difficulties arise when studying the cellular uptake of these NPs using commercially available fluorescence microscopy systems, since the selection of suitable luminescence detectors is limited. However, Nd 3+ ions are able to convert NIR radiation into visible light, showing upconversion properties. In this paper we found optimal parameters to excite upconversion luminescence of Nd 3+ :LaF 3 NPs in living cells and to compare the distribution of the NPs inside the cell culture of human macrophages THP-1 obtained by two methods. Firstly, by detecting the upconversion luminescence of the NPs in VIS under NIR multiphoton excitation using laser scanning confocal microscopy and secondly, using transmission electron microscopy

    ВИЗУАЛИЗАЦИЯ НАНОЧАСТИЦ LaF3, ДОПИРОВАННЫХ Nd3+, ДЛЯ БИОИМИДЖИНГА В БЛИЖНЕМ ИНФРАКРАСНОМ ДИАПАЗОНЕ ПО АП-КОНВЕРСИОННОЙ ЛЮМИНЕСЦЕНЦИИ ПРИ МИКРОСКОПИИ С МУЛЬТИФОТОННЫМ ВОЗБУЖДЕНИЕМ

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    Recent developments in the field of biophotonics facilitate the raise of interest to inorganic nanoparticles (NPs) doped with Nd3+ ions, because of their near-infrared (NIR) absorption. These NPs are interesting bioimaging probes for deep tissue visualization, while they can also act as local thermometers in biological tissues. Despite the good possibilities for visualization of NPs with Nd3+ ions in NIR spectral range, difficulties arise when studying the cellular uptake of these NPs using commercially available fluorescence microscopy systems, since the selection of suitable luminescence detectors is limited. However, Nd3+ ions are able to convert NIR radiation into visible light, showing upconversion properties. In this paper we found optimal parameters to excite upconversion luminescence of Nd3++:LaF NPs in living cells and to compare the distribution of the NPs inside the cell culture of human macrophages THP-1 obtained by two methods. Firstly, by detecting the upconversion luminescence of the NPs inVIS under NIR multiphoton excitation using laser scanning confocal microscopy and secondly, using transmission electron microscopy.Последние разработки в области биофотоники способствуют повышению интереса к неорганическим наночастицам (НЧ), допированным ионами Nd3+, из-за их поглощения в ближнем инфракрасном (БИК) спектральном диапазоне. Эти НЧ являются перспективными зондами для глубокой визуализации тканей, в то же время они могут служить локальными термометрами в биологических тканях. Несмотря на хорошие возможности визуализации НЧ с ионами Nd3+ в БИК спектральном диапазоне, при изучении внутриклеточного распределения этих НЧ с использованием коммерчески доступных флуоресцентных микроскопических систем возникают трудности из-за ограниченности выбора подходящих детекторов люминесценции. Однако, ионы Nd3+ способны преобразовывать БИК излучение в видимый свет, демонстрируя ап-конверсионные свойства. В этой работе мы определили оптимальные параметры для возбуждения ап-конверсионной люминесценции НЧ Nd3+: LaF в живых клетках и сравнили распределение НЧ внутри клеток культуры человеческих макрофагов THP-1, полученное двумя методами. Во-первых, путем регистрации ап-конверсионной люминесценции НЧ в видимом диапазоне при многофотонном возбуждении в БИК диапазоне спектра с использованием лазерной сканирующей конфокальной микроскопии и, во-вторых, с использованием просвечивающей электронной микроскопии

    НЕИНВАЗИВНАЯ ОЦЕНКА ЛОКАЛЬНОЙ ТЕМПЕРАТУРЫ НАГРЕВА БИОТКАНЕЙ ПОД ДЕЙСТВИЕМ ЛАЗЕРНОГО ИЗЛУЧЕНИЯ ПО СПЕКТРАМ ЛЮМИНЕСЦЕНЦИИ ИОНОВ Nd3+

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    Laser hyperthermia is one of the promising methods for treatment of oncological diseases. For routine clinical use of hyperthermia, it is necessary to control the uniformity and localization of heat within the tumor. Local heating can be achieved by using special thermal agents, such as nanoparticles doped with rare-earth ions. Measurement of the temperature of the thermal agents will allow timely regulation of the applied laser radiation excitation power and optimization of the hyperthermia process.The paper presents the results of a study on the non-invasive determination of the YPO4 nanoparticles doped with Nd3+ temperature with sensitivity of 0.2% °С-1 in 30-60°С temperature range. The temperature of the nanoparticles was calculated from the Nd3+ luminescence spectra in the 800-1000 nm range under excitation into 4F5/2 energy state by 805 nm laser. A calibration procedure for recalculating the ratio of the luminescence intensities from the Stark sublevels of the 4F3/2 Nd3+ state into the values of the real NP temperature in accordance with the Boltzmann distribution is given. An algorithm for calculating luminescence intensities for individual Stark components is proposed. After calculating the intensities corresponding to each individual Stark component, all the intensities related to the transition from the upper and lower Stark sublevels of the 4F3/2 state are summed, and then their ratio is calculated. The resulting ratio is normalized to the value of the ratio at room temperature and, in accordance with the calibration dependence, is recalculated into the NP heating temperature. It was demonstrated that the investigated 1%Nd3+:YPO4 nanoparticles can be used as "primary” thermometers that do not require additional recalibration to evaluate the temperature in the range used for hyperthermia.Одним из перспективных методов лечения онкологических заболеваний является метод лазерной гипертермии. Для рутинного клинического использования гипертермии необходимо контролировать однородность и локальность нагрева внутри опухоли. Добиться локального нагрева можно при использовании специальных термоагентов, в качестве которых могут выступать наночастицы (НЧ), допированные редкоземельными ионами. Измерение температуры термоагентов в режиме реального времени позволит своевременно регулировать подаваемую возбуждающую мощность лазерного излучения и оптимизировать режимы гипертермии.В работе представлены результаты исследования по неинвазивному определению температуры НЧ YPO4, допированных ионами Nd3+, c чувствительностью 0,2% °С-1 в диапазоне температур 30-60°С. Температура НЧ рассчитывалась по спектрам люминесценции Nd3+ в диапазоне 800-1000 нм при возбуждении на уровень 4F5/2 лазерным излучением 805 нм. Приведена процедура калибровки для пересчета отношения интенсивностей люминесценции со штарковских подуровней состояния 4F3/2 Nd3+ в значения реальной температуры НЧ в соответствии с распределением Больцмана. Предложен алгоритм расчета интенсивностей люминесценции для отдельных штарковских компонент. После вычисления интенсивностей, соответствующих каждой отдельной штарковской компоненте, происходит суммирование всех интенсивностей, относящихся к переходу с верхнего и с нижнего штарковских подуровней состояния 4F3/2, а затем вычисляется их отношение. Полученное отношение нормируется на значение отношения при комнатной температуре и в соответствии с калибровочной зависимостью пересчитывается в температуру нагрева НЧ. Продемонстрировано, что исследуемые НЧ Nd3+:YPO4 могут быть использованы в качестве так называемых «первичных» термометров, не требующих дополнительной перекалибровки для оценки температуры в диапазоне температур, используемом при гипертермии

    The optimization of treatment of patients with community-acquired pneumonia with high cardiovascular risk (case from practice).

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    Pneumonia occupies a significant part in the structure of morbidity and mortality of the population of Ukraine and the whole world. The incidence of this disease is several times higher among elderly patients. At the same time the prognosis for patients of this category can be fairly unfavorable, being connected with a number of age features. This fact, in its turn, points out the necessity of more precise criteria and new methods of assessing changes in the condition of a patient with pneumonia, and it also became a valid criterion to use in determining the severity and prognosis of the disease course. In this article the specific example of the application of the algorithm, named “Integral geriatric evaluation adapted for emergency care”, in the treatment of an elderly patient with pneumonia was considered. The role of statins in the complex treatment of patients with inflammatory diseases and their link with the level of C-reactive protein as a risk indicator of the unfavourable course of the disease in the form of the thrombotic complications was specifieced. So, medical care for elderly patients with pneumonia should be comprehensive in terms of diagnosis (improving the fairness through the application of the new and more precise methodology of assessing the functional state of a human organism) and treatment. The high degree of comorbidity among patients of the category “frail elderly” with pneumonia requires the application of approaches, which enable to reduce the cardiovascular risks and otherones. Such approaches include the administering of statins at high doses, in light of its impact on the level of C-reactive protein as a predictor of the thrombotic complications

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    The Optimization of Treatment of Patients with Community-acquired Pneumonia with High Cardiovascular Risk (Case From Practice).

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    Pneumonia occupies a significant part in the structure of morbidity and mortality of the population of Ukraine and the whole world. The incidence of this disease is several times higher among elderly patients. At the same time the prognosis for patients of this category can be fairly unfavorable, being connected with a number of age features. This fact, in its turn, points out the necessity of more precise criteria and new methods of assessing changes in the condition of a patient with pneumonia, and it also became a valid criterion to use in determining the severity and prognosis of the disease course. In this article the specific example of the application of the algorithm, named “Integral geriatric evaluation adapted for emergency care”, in the treatment of an elderly patient with pneumonia was considered. The role of statins in the complex treatment of patients with inflammatory diseases and their link with the level of C-reactive protein as a risk indicator of the unfavourable course of the disease in the form of the thrombotic complications was specifieced. So, medical care for elderly patients with pneumonia should be comprehensive in terms of diagnosis (improving the fairness through the application of the new and more precise methodology of assessing the functional state of a human organism) and treatment. The high degree of comorbidity among patients of the category “frail elderly” with pneumonia requires the application of approaches, which enable to reduce the cardiovascular risks and otherones. Such approaches include the administering of statins at high doses, in light of its impact on the level of C-reactive protein as a predictor of the thrombotic complications
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