Effect of a boron implantation on the electrical properties of epitaxial HgCdTe with different material composition

In this work the experimental results of investigations of the dynamics of accumulation and spatial distribution of electrically active radiation defects when irradiating epitaxial films of Hg1-xCdxTe (MCT) with different material composition (x). The films, grown by molecular beam epitaxy (MBE) were irradiated by B ions at room temperature in the radiation dose range 1012 -1015 ions/cm2 and with ion energy 100 keV. The results give the differences in implantation profiles, damage accumulation and electrical properties as a function of the material composition of the film

ВЛИЯНИЕ ГЛУБОКОЙ АНЕСТЕЗИИ НА ВОЗНИКНОВЕНИЕ ПОСЛЕОПЕРАЦИОННОЙ КОГНИТИВНОЙ ДИСФУНКЦИИ

The profound deepening of medicamentous sleep down to the burst-suppression electroencephalography pattern is used to provide medication-based protection of brain during preventive temporary clipping of the major arteries when performing surgery due to cerebral aneurysms. There is no consensus about the effect of profound suppression of electrobiological activity on the development of post-operative cognitive dysfunction. The goal: to evaluate the impact of anesthesia with the burst-suppression electroencephalography pattern on the post-operative cognitive status of the patients with no cerebral disorders. Subjects and methods. 30 patients were enrolled into the prospective randomized study, they all had surgeries due to degenerative spinal diseases. All patients were divided into two groups. Anesthesia in the main group (Group 1) differed from the one in the control group (Group 2); it included administration of propofol till achieving suppression of the electrobiological activity of burst-suppression electroencephalography pattern during 15 minutes. Prior to the surgery and in 4 days after it, all patients had neuro-psychological tests using Montreal Cognitive Assessment (MoCA), Frontal Assessment Battery (FAB) and numbers memorization techniques (NMT). Results. When testing in 4 days after surgery, results in the patients from Group 1 did not differ from pre-operative results of MoCA (Mebefore = 28, Meafter= 28, Z = 0.714, p = 0.476), FAB (Mebefore = 18, Meafter = 18, Z = 0.592, p = 0.554), memorization of numbers in the direct order (Mebefore = 18, Meafter = 18, Z = 0.178, p = 0.859) and in the reverse order (Mebefore = 18, Meafter = 18, Z = 0.548, p = 0.583). The results of the post-operative testing in Group 2 were compatible with pre-operative results of (Mebefore = 18, Meafter = 18, Z = 0.459, p = 0.646), FAB (Mebefore = 18, Meafter = 18, Z = 1.348, p = 0.178), memorization of numbers in the direct order (Mebefore = 18, Meafter = 18, Z = 0.21, p = 0.843) and in the reverse order (Mebefore = 18, Meafter = 18, Z = 0.809, p = 0.418). None of the tests detected significant differences between the Groups (U = 88, p = 0.319, Z = 0.995 for MoCA; U = 102.5, p = 0.644, Z = 0.394 for FAB; U = 92.0, p = 0.407, Z = -0.829 for memorization of numbers in the direct order, and U = 33.5, p = 0.62, Z = 0.572 for memorization of numbers in the reverse order). Conclusion. Anesthesia with burst-suppression electroencephalography pattern as a model of medication-based cerebral protection during temporary clipping of the major arteries does not cause the deterioration of cognitive status in the patients who had no cerebral pathology initially. Для медикаментозной защиты головного мозга в период превентивного временного клипирования магистральных артерий при операциях по поводу церебральных аневризм применяют значительное углубление медикаментозного сна до появления на электроэнцефалограмме паттерна «вспышка ‒ подавление». Нет единого мнения в отношении влияния выраженного угнетения биоэлектрической активности на возникновение послеоперационной когнитивной дисфункции. Цель: оценить влияние анестезии с электроэнцефалографическим паттерном «вспышка ‒ подавление» на послеоперационный когнитивный статус пациентов без патологии головного мозга. Материалы и методы. В проспективном рандомизированном исследовании участвовали 30 пациентов, которым выполнили хирургическое лечение по поводу дегенеративных заболеваний позвоночника. Все пациенты были разделены на две группы. Анестезия в основной группе (1-я группа) отличалась от контрольной (2-я группа) введением пропофола до появления в биоэлектрической активности головного мозга паттерна «вспышка ‒ подавление» в течение 15 мин. Перед операцией и на 4-е сут после вмешательства всем пациентам проводили нейропсихологическое тестирование с использованием Монреальской шкалы оценки психических функций (MoCA), батареи тестов для оценки лобной дисфункции (FAB) и методики запоминания цифр. Результаты. При обследовании на 4-е сут после операции в 1-й группе пациентов не отличались от предоперационных показателей результаты тестов MoCA (Meдо = 28, Meпосле = 28, Z = 0,714, p = 0,476), FAB (Meдо = 18, Meпосле = 18, Z = 0,592, p = 0,554), запоминания цифр в прямом (Meдо = 18, Meпосле = 18, Z = 0,178, p = 0,859) и обратном порядке (Meдо = 18, Meпосле = 18, Z = 0,548, p = 0,583). Во 2-й группе пациентов результаты послеоперационного обследования были сопоставимы с предоперационными данными тестов MoCA (Meдо = 18, Meпосле = 18, Z = 0,459, p = 0,646), FAB (Meдо = 18, Meпосле = 18, Z = 1,348, p = 0,178), запоминания цифр в прямом (Meдо = 18, Meпосле = 18, Z = 0,21, p = 0,843) и обратном порядке (Meдо = 18, Meпосле = 18, Z = 0,809, p = 0,418). Между 1-й и 2-й группами значимых отличий не выявлено ни по одной из методик (U = 88, p = 0,319, Z = 0,995 для MoCA; U = 102,5, p = 0,644, Z = 0,394 для FAB; U = 92,0, p = 0,407, Z = -0,829 для запоминания в прямом и U = 33,5, p = 0,62, Z = 0,572 для запоминания в обратном порядке). Вывод. Проведение анестезии с электроэнцефалографическим паттерном «вспышка ‒ подавление» как модели медикаментозной защиты мозга на период временного клипирования магистральных артерий не приводит к ухудшению когнитивного статуса пациентов без исходной патологии головного мозга.

Properties of arsenic-implanted Hg1-xCdxTe MBE films

Defect structure of arsenic-implanted Hg1-xCdxTe films (x=0.23–0.30) grown with molecular-beam epitaxy on Si substrates was investigated with the use of optical methods and by studying the electrical properties of the films. The structural perfection of the films remained higher after implantation with more energetic arsenic ions (350 keV vs 190 keV). 100%-activation of implanted ions as a result of post-implantation annealing was achieved, as well as the effective removal of radiation-induced donor defects. In some samples, however, activation of acceptor-like defects not related to mercury vacancies as a result of annealing was observed, possibly related to the effect of the substrate

Accumulation and annealing of radiation donor defects in arsenic-implanted Hg0.7Cd0.3Te films

Processes of accumulation and annealing of radiation-induced donor defects in arsenic-implanted Hg0.7Cd0.3Te films were studied with the use of the Hall-effect measurements with processing the data with mobility spectrum analysis. A substantial difference in the effects of arsenic implantation and post-implantation activation annealing on the properties of implanted layers and photodiode ‘base’ layers in Hg0.7Cd0.3Te and Hg0.8Cd0.2Te films was established and tentatively explained

Localization and nature of radiation donor defects in the arsenic implanted CdHgTe films grown by MBE

By profiling the electrical parameters of the arsenic implanted CdHgTe films, grown by molecular bea

Fluence dependence of nanosize defect layers in arsenic implanted HgCdTe epitaxial films studied with TEM/HRTEM

We report on the results of comparative study of fluence dependence of defect layers in molecular-beam epitaxy-grown epitaxial film of p-Hg1-х CdхTe (х=0.22) implanted with arsenic ions with 190 keV energy and fluence 1012, 1013, and 1014 cm-2

EFFECT OF DEEP ANESTHESIA ON DEVELOPMENT OF POST-OPERATIVE COGNITIVE DYSFUNCTION

The profound deepening of medicamentous sleep down to the burst-suppression electroencephalography pattern is used to provide medication-based protection of brain during preventive temporary clipping of the major arteries when performing surgery due to cerebral aneurysms. There is no consensus about the effect of profound suppression of electrobiological activity on the development of post-operative cognitive dysfunction. The goal: to evaluate the impact of anesthesia with the burst-suppression electroencephalography pattern on the post-operative cognitive status of the patients with no cerebral disorders. Subjects and methods. 30 patients were enrolled into the prospective randomized study, they all had surgeries due to degenerative spinal diseases. All patients were divided into two groups. Anesthesia in the main group (Group 1) differed from the one in the control group (Group 2); it included administration of propofol till achieving suppression of the electrobiological activity of burst-suppression electroencephalography pattern during 15 minutes. Prior to the surgery and in 4 days after it, all patients had neuro-psychological tests using Montreal Cognitive Assessment (MoCA), Frontal Assessment Battery (FAB) and numbers memorization techniques (NMT). Results. When testing in 4 days after surgery, results in the patients from Group 1 did not differ from pre-operative results of MoCA (Mebefore = 28, Meafter= 28, Z = 0.714, p = 0.476), FAB (Mebefore = 18, Meafter = 18, Z = 0.592, p = 0.554), memorization of numbers in the direct order (Mebefore = 18, Meafter = 18, Z = 0.178, p = 0.859) and in the reverse order (Mebefore = 18, Meafter = 18, Z = 0.548, p = 0.583). The results of the post-operative testing in Group 2 were compatible with pre-operative results of (Mebefore = 18, Meafter = 18, Z = 0.459, p = 0.646), FAB (Mebefore = 18, Meafter = 18, Z = 1.348, p = 0.178), memorization of numbers in the direct order (Mebefore = 18, Meafter = 18, Z = 0.21, p = 0.843) and in the reverse order (Mebefore = 18, Meafter = 18, Z = 0.809, p = 0.418). None of the tests detected significant differences between the Groups (U = 88, p = 0.319, Z = 0.995 for MoCA; U = 102.5, p = 0.644, Z = 0.394 for FAB; U = 92.0, p = 0.407, Z = -0.829 for memorization of numbers in the direct order, and U = 33.5, p = 0.62, Z = 0.572 for memorization of numbers in the reverse order). Conclusion. Anesthesia with burst-suppression electroencephalography pattern as a model of medication-based cerebral protection during temporary clipping of the major arteries does not cause the deterioration of cognitive status in the patients who had no cerebral pathology initially

Electrical characteristics of epitaxial MCT after As+ implantation

In this work we studied the characteristics of MBE MCT films after the introduction of different energies As+ with different doses of irradiation. Some of the samples were subjected to post-implantation annealing. Electrical characteristics of the samples were determined from Hall measurements. Voltage-current characteristics of the structures were also measured. Activation As and modification of the characteristics of MCT outside the implanted layer after annealing have been detected. Also we found differences in the p-n junction depths and electrically active defects profiles