Vortex shedding behind an obstacle in a channel under transition to turbulence in steady and pulsating flows

© Published under licence by IOP Publishing Ltd. Experimental research and DNS of separated flow over a spanwise semicylindrical rib mounted in a rectangular channel have been performed for the cases of steady and pulsating flow with transition to turbulence. Spiral motion of fluid behind the rib directed from the channel walls towards the channel symmetry plane has been shown to govern the formation of large vortices in the mixing layer starting from some critical Reynolds number. The mechanism of origination of such motion has been hypothesized. The effect of frequency and amplitude of forced freestream pulsations on the vortex pattern behind the rib has been described

Новый спиральный экспандер шлеммова канала в хирургии открытоугольной глаукомы

PURPOSE: To evaluate the safety and effectiveness of Schlemm's canal (SC) dilation with stainless steel spiral Schlemm's canal expander (SCE) in decreasing intraocular pressure (IOP) in patients with open angle glaucoma (OAG). MATERIAL AND METHODS: Eighteen consecutive patients (18 eyes) with OAG, who's IOP was insufficiently controlled by their current ocular hypotensive medications were operated upon. A 4-5 mm long SCE made from 0.05 mm thick medical grade stainless steel wire was implanted into the SC lumen ab externo. In 6 cases with coexisting pathology a combined two site procedure - phacoemulsification with implantation of an intraocular lens (IOL) and SCE implantation was performed. Primary outcome measure was IOP change, secondary - number of glaucoma medications pre-and postoperatively and complications. A paired t-test was used for IOP and medication analysis. Decrease in IOP >25% or IOP 18 mm Hg or less without medication was considered a complete success, with medication - partial success. Failure was considered if the patient needed subsequent filtering surgery. Results were significant with pЦЕЛЬ. Оценить эффективность и безопасность применения нового спирального экспандера шлеммова канала (ЭШК) для дилятации шлеммова канала (ШК) для снижения внутриглазного давления (ВГД) у пациентов с ОУГ. МАТЕРИАЛЫ И МЕТОДЫ. Прооперированы 18 человек (18 глаз) с открытоугольной глаукомой (ОУГ), у которых ВГД не компенсировалось на максимальной гипотензивной терапии. Всем пациентам имплантировали ЭШК наружным доступом. ЭШК изготовлен из проволоки нержавеющей стали медицинского качества толщиной 0,05 мм, длиной 4-5 мм, кривизна соответствует кривизне ШК. В 6 случаях была произведена одномоментная комбинированная хирургия по поводу катаракты и глаукомы - факоэмульсификация с имплантацией интра-окулярной линзы и имплантацией ЭШК в ШК. Критериями оценки являлись динамика ВГД, необходимость применения гипотензивных капель до и после операции и частота осложнений. Для статистического анализа использовали двухвыборочный t-тест. Результаты считались достоверными при

Оценка эффективности стального спирального экспандера шлеммова канала Кумара 2-го поколения в снижении внутриглазного давления у пациентов с рефрактерной глаукомой

PURPOSE: To evaluate effectiveness of Kumar's 2nd generation stainless steel spiral Schlemm's canal expander (SCE) in decreasing intraocular pressure (IOP) in patients with primary open-angle glaucoma (OAG) refractory to previous penetrating and non-penetrating glaucoma surgeries. METHODS: Nine consecutive patients (9 eyes) having failed filters (failed trabeculectomy - 6 cases, failed deep sclerectomy - 2 cases and failed selective laser trabeculoplasty - 1 case), who's IOP was insufficiently controlled, were operated upon. A 2.5-3.0 mm long stainless steel spiral 2nd generation SCE made from 0.04mm thick medical grade stainless steel wire, having outer diameter of 0.2 mm and inner lumen diameter of 0.12 mm was implanted into Schlemm's canal (SC) ab externo. Two patients (2 eyes) with coexisting cataract and glaucoma underwent a combined procedure. Patients were evaluated daily during hospital stay, after 1 week, and at 1, 3, 6 and 12 months after surgery. IOP was considered a primary outcome measure. Secondary outcome measures were as follows: the number of glaucoma medications pre- and postoperatively and complications. A paired t-test was used for IOP and medication analysis. Decrease in IOP >20% or IOP from 6 to 18 mmHg without medication was considered a complete success, with medication - partial success. Failure was declared if the patient had IOP 18 or reduction in IOP wasЦЕЛЬ. Оценить эффективность применения стального спирального экспандера шлеммова канала (ЭШК) 2-го поколения в снижении внутриглазного давления (ВГД) у пациентов с рефрактерной глаукомой. МЕТОДЫ. Прооперировано 9 человек (9 глаз) с рефрактерной глаукомой, у которых ВГД не контролировалось на максимальной гипотензивной терапии. Из них у 6 больных ранее была проведена трабекулэктомия, у 2 - глубокая склерэктомия и у 1 - селективная лазеропластика. Всем пациентам имплантировали ЭШК 2-го поколения наружным доступом. ЭШК изготовлен из проволоки нержавеющей стали медицинского качества толщиной 0,04 мм, длиной 2,5-3,0 мм, наружный диаметр - 0,2 мм, внутренний - 0,12 мм, кривизна соответствует кривизне ШК. В 2 случаях была произведена одномоментная комбинированная хирургия по поводу катаракты и глаукомы. Осмотр пациентов проводили ежедневно в стационаре, далее через 1 неделю, 1, 3, 6 и 12 месяцев. Критериями оценки являлись динамика ВГД, необходимость применения гипотензивных капель до и после операции и частота осложнений. Снижение ВГД >20% и

Оценка эффективности и безопасности применения экспандера шлеммова канала Кумара в лечении открытоугольной глаукомы у больных с сопутствующей катарактой

PURPOSE: To evaluate safety and effectiveness of Schlemm's canal expander (SCE) in management of open-angle glaucoma (OAG) in cataract patients. METHODS: A total of 9 cases (9 eyes) having visually significant cataract and insufficiently controlled by their current ocular hypotensive medication(s) glaucoma were operated upon. There were 5 cases of pseudoexfoliation syndrome, rigid pupils and weakening of Zinn's ligaments resulting in instability of native lens and requiring implantation of a capsule tension ring (CTR) into the capsular bag to stabilize it. A one-stage combined surgery - phacoemulsification with in-the-bag implantation of a foldable acrylic hydrophilic intraocular lens (IOL) and implantation of SCE in Schlemm's canal (SC) was performed in all cases. A 4-5 mm long SCE made from 0.05mm thick medical grade vanadium stainless steel wire was implanted into the SC lumen by ab externo approach. Primary outcome measure was intraocular pressure (IOP) change, secondary - number of glaucoma medications pre- and postoperatively and complications. A paired t-test was used for IOP and medication analysis. 25% decrease in IOP or IOP of 18 mm Hg or less without medication was considered a complete success, with medication - partial success. The need for subsequent filtering surgery was qualified as failure. Success was evaluated on the basis of Kaplan-Meier cumulative probability at each follow-up visit. Results were considered statistically significant with pЦЕЛЬ. Оценить эффективность и безопасность применения экспандера шлеммова канала (ЭШК) Кумара в лечении открытоугольной глаукомы (ОУГ) у больных с катарактой. МЕТОДЫ. Прооперировано 9 человек (9 глаз) с катарактой и ОУГ, у которых внутриглазное давление (ВГД) не компенсировалось на максимальной гипотензивной терапии. У 5 больных был диагностирован псевдоэксфолиативный синдром, у этих пациентов имели место узкие зрачки и выраженный факодонез, нуждающийся в имплантации капсульного кольца для стабилизации капсульного мешка. Всем пациентам проведена одномоментная комбинированная хирургия - факоэмульсификация с имплантацией складывающейся гидрофильной интраокулярной линзы (ИОЛ) в капсульный мешок и имплантация ЭШК в просвет шлеммова канала (ШК). ЭШК длиной 4-5 мм изготовлен из проволоки нержавеющей ванадиевой стали медицинского качества толщиной 0,05 мм, имплантирован в просвет ШК ab externo. Критериями оценки являлись динамика ВГД, необходимость применения гипотензивных капель до и после операции и частота осложнений. Для статистического анализа использовали двухвыборочный t-тест. Снижение ВГД более чем на 25% или ВГД равное 18 и меньше без применения гипотензивной терапии считалось полным успехом, с применением гипотензивной терапии - частичным. Необходимость в проведении последующей операции считалась неудачей. Успех оценивали при каждом посещений пациента с использованием кривой выживаемости Каплана - Мэйэра. Результаты считались достоверными при

Analysis of effectiveness of activities on early detection and treatment of tuberculosis combined with HIV infection at regional level

Presented the results of the analysis of the effectiveness of antituberculous activities and the effectiveness of treatment of patients with tuberculosis, combined with HIV- infection for the period 2010 - 2017 in the Irkutsk region. In order to assess the effectiveness of TB interventions among people with HIV infection in the Irkutsk region, statistical data for 8 years from annual reports and statistical forms were analyzed. During the analyzed period, high effectiveness of antituberculous activities among patients with HIV infection in the Irkutsk region was noted. The key problem is the low adherence of patients with HIV infection to dispensary observation and treatment, and as a consequence, the implementation of preventive measures among them and treatment of tuberculosis. This indicates an unfavorable prognosis of the further spread of tuberculosis among HIV-infected people.Представлены результаты анализа эффективности противотуберкулезных мероприятий и эффективности лечения больных туберкулезом, сочетанным с ВИЧ-инфекцией за период 2010 – 2017гг. в Иркутской области. С целью оценки эффективности мероприятий по туберкулезу среди лиц с ВИЧ-инфекцией в Иркутской области осуществлен анализ статистических данных за 8 лет, полученных из годовых отчетов и статистических форм. За анализируемый период отмечена высокая эффективность противотуберкулезных мероприятий среди больных ВИЧ-инфекцией в Иркутской области. ключевой проблемой является низкая приверженность больных ВИЧ-инфекцией к диспансерному наблюдению и лечению и как следствие, осуществлению среди них профилактических мероприятий и лечения туберкулеза. Это свидетельствует о неблагоприятном прогнозе дальнейшего распространения туберкулеза среди ВИЧ-инфицированных

SUDDEN DEATH PREDICTORS IN PATIENTS AFTER MYOCARDIAL INFARCTION BY HOLTER ECG MONITORING

The recent data is considered on the prevalence, electrophysiology, mechanisms and risk factors of sudden cardiac death in patients after acute myocardial infarction. The data is shown about Holter monitoring of ECG as a method (these methods are in use in systems like Astrocard® Holtersystem, GE Healthcare MARS, medilog® DARWIN), that stratifies the risk of sudden cardiac death development. The prognostic role and importance of specific parameters of 24-hour ECG monitoring is studied, correlating with the higher risk of life-threatening rhythm disorders that are the main mechanisms of sudden cardiac death. The estimation of the main predictors of electrical instability of myocardium is done

SPECTRAL HEART RATE VARIABILITY PARAMETERS, DELAYED VENTRICULAR POTENTIALS AND RATE TURBULENCE AS MARKERS OF CORONARY PERFUSION IN STEMI

Aim. To assess the dynamics of parameters representing rhythmical activity of the heart related to the efficacy of pharmaco-invasive revascularization in STEMI patients.Material and methods. Totally 56 STEMI patients included that had undergone effective thrombolysis by ECG criteria of reperfusion, after that in 3-24 hours the coronary arteriography and stenting was done. Before and after PCI the telemetric ECG registration was done via “Astrocard® — Telemetry” (Meditek Ltd.,Russia). The automatic analysis of spectral parameters was done for HRV, LVP, RT.Results. In coronary artery re-thrombosis development there is a decrease of spectrum power (TotP) (p=0,001) and increase of vagosympathic balance (L/H) (p=0,005) that points on the increase of autonomic regulation and decentralization of heart activity management. Backward dynamics is registered after successful PCI that might be related with the balance restoration between sympathetic and parasympathetic systems in effective revascularization. The tendency revealed to the increase of QRSf in re-thrombosis group and it is shown that in delayed PCI there is a growth of RMS (p=0,04), that points on the higher risk of electrical instability development.Conclusion. The markers of developing re-thrombosis of infarction-related artery in STEMI are increase of lower frequency parameters of HRV (VLfp and LfP), decrease of total spectrum power of HRV, increase of L/H index and increase of the duration of QRSf. In delayed PCI there are higher values of RMS that represents electrical instability of myocardium for this type of patients. Telemetric ECG monitoring in STEMI patients significantly increases opportunities of the dynamic evaluation of coronary flow and electrical instability of myocardium

HEART RATE VARIABILITY, VENTRICULAR LATE POTENTIALS AND HEART RATE TURBULENCE AS INDICATORS OF CORONARY REPERFUSION IN ST SEGMENT ELEVATION MYOCARDIAL INFARCTION

Aim. To evaluate the dynamics of the parameters of autonomic balance and electrical instability of the myocardium depending on the effectiveness of the restoration of coronary blood flow in pharmacoinvasive revascularization in patients with acute ST segment elevation myocardial infarction.Material and methods. The study included 91 patients who underwent effective thrombolytic therapy (TLT) according to the ECG criteria, followed by (3-24 hour later) coronary angiography with percutaneous coronary intervention (PCI). Before and after PCI the telemetric ECG recording was conducted. The dynamics of the temporal and spectral characteristics of heart rate variability (HRV), presence of ventricular late potentials (VLP) and abnormal heart rate turbulence (HRT) were evaluated.Results. The episodes of ST-segment re-elevation by1 mm or more, lasting at least 1 min, and the dynamics of some HRV indices indicated the development of rethrombosis after TLT. The increase in the mean square deviation of normal intervals to 82.5 (64.5; 94) ms, the average value of the standard deviations of normal intervals calculated over 5-minute intervals throughout the entire recording to 37.5 (31.5; 47.5) ms, the total power of the spectrum and the power of high frequency waves, as well as the decrease in the power of ultra-low frequency waves were found after PCI in the group with a rethrombosis of the infarct-related coronary artery. The analysis of VLP in this group showed an increase in duration of the filtered QRS complex after TLT (to 128.7±34.5 ms), and the root mean square value of the last 40 ms of the QRS complex after PCI (to 49±50.3 μV).Pathological deviations of the HRT parameters (especially the onset of turbulence) independently on the absolute values were registered more often in patients with rethrombosis, and abnormal values of both HRT parameters were found only in patients with episodes of unstable coronary blood flow.Conclusion. The results are the indirect evidences of disruption of autonomic regulation of cardiac activity and increased arrhythmic readiness of myocardium in developing rethrombosis of coronary artery. The pronounced reperfusion injury of the myocardium evidently plays an important role in this process and is associated with embolization of the vessels of the microcirculatory bed, release of free radicals and alteration of cardiomyocytes, especially due to prolonged ischemia

HEART RATE VARIABILITY, VENTRICULAR LATE POTENTIALS AND HEART RATE TURBULENCE AS INDICATORS OF CORONARY REPERFUSION IN ST SEGMENT ELEVATION MYOCARDIAL INFARCTION

Aim. To evaluate the dynamics of the parameters of autonomic balance and electrical instability of the myocardium depending on the effectiveness of the restoration of coronary blood flow in pharmacoinvasive revascularization in patients with acute ST segment elevation myocardial infarction.Material and methods. The study included 91 patients who underwent effective thrombolytic therapy (TLT) according to the ECG criteria, followed by (3-24 hour later) coronary angiography with percutaneous coronary intervention (PCI). Before and after PCI the telemetric ECG recording was conducted. The dynamics of the temporal and spectral characteristics of heart rate variability (HRV), presence of ventricular late potentials (VLP) and abnormal heart rate turbulence (HRT) were evaluated.Results. The episodes of ST-segment re-elevation by1 mm or more, lasting at least 1 min, and the dynamics of some HRV indices indicated the development of rethrombosis after TLT. The increase in the mean square deviation of normal intervals to 82.5 (64.5; 94) ms, the average value of the standard deviations of normal intervals calculated over 5-minute intervals throughout the entire recording to 37.5 (31.5; 47.5) ms, the total power of the spectrum and the power of high frequency waves, as well as the decrease in the power of ultra-low frequency waves were found after PCI in the group with a rethrombosis of the infarct-related coronary artery. The analysis of VLP in this group showed an increase in duration of the filtered QRS complex after TLT (to 128.7±34.5 ms), and the root mean square value of the last 40 ms of the QRS complex after PCI (to 49±50.3 μV).Pathological deviations of the HRT parameters (especially the onset of turbulence) independently on the absolute values were registered more often in patients with rethrombosis, and abnormal values of both HRT parameters were found only in patients with episodes of unstable coronary blood flow.Conclusion. The results are the indirect evidences of disruption of autonomic regulation of cardiac activity and increased arrhythmic readiness of myocardium in developing rethrombosis of coronary artery. The pronounced reperfusion injury of the myocardium evidently plays an important role in this process and is associated with embolization of the vessels of the microcirculatory bed, release of free radicals and alteration of cardiomyocytes, especially due to prolonged ischemia

Spectral Analysis of a Vortex Wake Behind a Circular Cylinder in a Channel at Moderate Reynolds Numbers

Abstract: Direct numerical simulation is employed to study the complex vortical flow in the wake of a circular cylinder in a rectangular channel at 102. Formation and development of vortices behind bodies are governed by two phenomena: Karman street in the central part of the channel and a pair of spiral peripheral vortices near the channel sidewalls. Both of these phenomena introduce their own disturbances to the flow and can be essential depending on the Reynolds number and geometry of the cross section. Fourier transform yielded spectral density of kinetic energy of velocity fluctuations at fixed sample points in the flow and also revealed the patterns in formation of vortical properties of the wake, including the transition to turbulence and self- oscillations of aerodynamics coefficients of the streamlined body