44 research outputs found
Locking bandwidth of two laterally coupled semiconductor lasers subject to optical injection
We report here for the first time (to our knowledge), a new and universal mechanism by which a two-element laser array is locked to external optical injection and admits stably injection-locked states within a nontrivial trapezoidal region. The rate equations for the system are studied both analytically and numerically. We derive a simple mathematical expression for the locking conditions, which reveals that two parallel saddle-node bifurcation branches, not reported for conventional single lasers subject to optical injection, delimit the injection locking range and its width. Important parameters are the linewidth enhancement factor, the laser separation, and the frequency offset between the two laterally-coupled lasers; the influence of these parameters on locking conditions is explored comprehensively. Our analytic approximations are validated numerically by using a path continuation technique as well as direct numerical integration of the rate equations. More importantly, our results are not restricted by waveguiding structures and uncover a generic locking behavior in the lateral arrays in the presence of injection
CUMULATIVE CARDIO-VASCULAR RISK IN HYPERTENSIVE PATIENTS: EFFECTS OF ANGIOTENSIN CONVERTING ENZYME INHIBITORS
Aim. To assess cumulative cardio-vascular (CV) risk and elasticity of big-to-middle size arteries in hypertensive patients depending on age, sex and enalapril (Enap, Dr. Reddy’s) effects on these features.Material and methods. 143 patients with arterial hypertension of 1-2 stages were split in 3 groups: 1st – patients younger than 55 y.o. (17 men, 27 women before menopause); 2nd – patients aged 55-65 y.o. (16 men, 38 women); 3rd – elder than 65 y.o. (11 men, 34 women). Fatal CV risk according to SCORE scale and cumulative risk of acute coronary disease (CAD) events according to PRCAM program was assessed before and after 4 weeks of enalapril therapy (5-30 mg/d). Besides the speed of pulse wave spread (SPWS) was determined by method of volume sphygmography.Results. Normal SPWS in elastic arteries was observed in women under 55 y.o. SPWS disturbances were detected in elderly patients. Lower blood pressure (BP) levels and better plasma lipid profile was found in women of young and middle age in comparison with these in men of the same age. More than 80% of hypertensive patients have high CV risk, especially in elderly ones. Enam improved SPWS in elastic arteries, reduced BP and cumulative CV risk.Conclusion. There are gender and age differences between BP levels, SPWS indices, plasma lipid profiles and cumulative CV risks in hypertensive patients. Enalapril improves these characteristics.</p
Evaluation of Drug Therapy and Adherence to It in Patients after Acute Coronary Syndrome in Real Clinical Practice (Results of One Year Observation)
Aim. To study the prescribed drug therapy, as well as adherence to it in patients with acute coronary syndrome (ACS) in real clinical practice within a year after the index event. Material and methods. The study included 327 patients who were in hospital treatment with ACS: 199 patients (60.9%) with unstable angina (UA) and 128 (39.1%) – with acute myocardial infarction (AMI). The prescribed treatment and adherence to therapy were evaluated within 12 months after the coronary event. Therapy prescribed to patients was compared with current clinical guidelines for the treatment of patients with ACS. Results. 67% of patients completed the clinical study Adherence to prescribed medication within 12 months after ACS was maximal for ACE inhibitors/angiotensin receptor blockers (83.6%), dual antiplatelet therapy (79.9%) and β-blockers (78.1%), and minimal for lipid-lowering drugs (statins; 61.6%). A significant decrease in adherence was revealed in 6 and 12 months from the initiation of therapy. Significantly higher level of adherence to DAT was found in patients with AMI compared with patients with UA (p<0.05). When analyzing the frequency of occurrence of endpoints, it was found that patients who did not adhere to treatment significantly more often had hospitalizations due to UA (15.1% vs 7.4%; p<0.05), AMI (16.9% vs 8.1%; p<0.05), death from cardiovascular causes (13% vs 10.4%; p<0.05). Conclusion. Therapy prescribed at the outpatient stage in patients with ACS in the Rostov Region corresponds to the modern clinical recommendations. Six months after hospital discharge adherence to drug therapy in patients is reduced, which requires more careful outpatient monitoring during this period. In patients who are not adherent to treatment, cardiovascular complications are significantly more frequent
PHARMACEUTICAL CORRECTION OF VASCULAR DISTURBANCES IN PATIENTS WITH ARTERIAL HYPERTENSION
Aim: To study vascular stiffness and elasticity, microcirculation (MC) parameters, and mildronate effects in patients with arterial hypertension (AH). Material and methods. The study included 99 patients with Stage I-II AH (mean age 63,2+2,6 years). Pulse wave velocity was assessed by volume sphygmography (Poly-Spectre system, Neuro-Soft). MC parameters were assessed with a computerised Doppler ultrasound device (Minimax-Doppler-K). After a wash-out period, the participants were randomised into 2 groups. Group I received enalapril (Renipril, Pharmstandard; 10 mg/d) and mildronate (0,25 g twice a day). Group II was administered Renipril (10 mg/d) only. Results. After 12 weeks of the treatment, blood pressure (BP) levels were significantly reduced. In Group I, a significant increase in mean linear blood flow velocity after occlusion test, as well as in volume blood flow velocity, was observed, compared to the baseline. In 66% of the patients, blood flow velocity after occlusion test was increased by at least 20%. Conclusion. Adding mildronate to the standard antihypertensive therapy with ACE inhibitors facilitates faster normalisation of vascular function
ECOLOGICAL STRESS AND ITS EFFECTS ON ESSENTIAL HYPERTENSION AND CHRONIC OBSTRUCTIVE BRONCHITIS DEVELOPMENT IN ROSTOV-ON-DON INHABITANTS
Aim. To study prevalence of essential hypertension (HT) and chronic obstructive bronchitis (COB) among Rostov-on-Don population, to assess influence of ecological stress on HT and COB development and to find the ways to improve therapy of combined pathology.Material and methods. Single-stage epidemiologic study of Rostov-on-Don population was carried out. The study included questionnaire to reveal main risk factors of chronic noninfectious diseases, a number of laboratory and instrumental indices.Results. Prevalence of HT and COB is significantly higher in patients, living in ecologically unfavorable districts. Rigidity and stretch ability of vascular wall influence the course and development of HT as well as atrial natriuretic factor. Carbonic anhydrase inhibitor, acetazolamide, when is added to standard therapy increases in its efficacy in blood pressure control, decrease in blood pressure in pulmonary artery and correction of disturbed acidbase balance in patients with HT combined with COB.Conclusion. The connection between unfavorable ecology and HT and COB development is demonstrated. Adjuvant therapy with acetazolamide is proposed to increase in efficacy of HT and COB standard therapy
Cardiovascular disease and non-communicable disease behavioral risk factor screening in Rostov-na-Donu citizens
A cardiovascular disease (CVD) screening study of 1350 Rostov-na-Donu citizens was performed. According to calculated clinical sensitivity and specificity, perspectives of «Cardiovisor - Obs « device use, as primary indicator of heart health and regulatory mechanisms status in screening studies, were determined. Among Rostov-na-Donu citizens, leading behavioral risk factors for non-communicable disease included smoking, low physical activity, and unhealthy diet, resulting in overweight and obesity. There is a need for special preventive program focused on suboptimal ecology region inhabitants