Design optimization for bright electrically-driven quantum dot single-photon sources emitting in telecom O-band.

A combination of advanced light engineering concepts enables a substantial improvement in photon extraction efficiency of micro-cavity-based single-photon sources in the telecom O-band at ∼1.3 µm. We employ a broadband bottom distributed Bragg reflector (DBR) and a top DBR formed in a dielectric micropillar with an additional circular Bragg grating in the lateral plane. This device design includes a doped layer in pin-configuration to allow for electric carrier injection. It provides broadband (∼8-10 nm) emission enhancement with an overall photon-extraction efficiency of ∼83% into the upper hemisphere and photon-extraction efficiency of ∼79% within numerical aperture NA=0.7. The efficiency of photon coupling to a single-mode fiber reaches 11% for SMF28 fiber (with NA=0.12), exceeds 22% for 980HP fiber (with NA=0.2) and reaches ∼40% for HNA fiber (with NA=0.42) as demonstrated by 3D finite-difference time-domain modeling.

[State of microcirculation in patients with atherosclerosis and diabetes mellitus after limb revascularization]. / Sostoianie mikrotsirkuliatsii u bol'nykh aterosklerozom i sakharnym diabetom posle revaskuliarizatsii konechnosti.

AIM: The study was aimed at comparatively assessing the dynamics of the parameters of the microcirculatory bed of the skin after endovascular revascularization of the lower limb in patients suffering from intermittent claudication (IC) with and without type 2 diabetes mellitus (DM). PATIENTS AND METHODS: Microcirculation (MC) of the skin of lower extremities was examined in 88 male patients presenting with IC and without DM (Group One) and in 28 male patients with IC and DM (Group Two). 30 patients from Group One and 21 patients from Group Two were subjected to endovascular revascularization of lower limbs. MC was examined on the 2nd day after restoration of blood flow in the extremity by means of laser Doppler flowmetry with the assessment of the amplitude parameters of blood flow fluctuations, reflecting active and passive mechanisms of regulation of microcirculation, the intensity of blood flow through the arteriole-venule shunts and the nutritive blood flow. RESULTS: At baseline, the main parameters of MC had no differences in the groups and were characterized by intensification of the blood shunted bypassing the nutritive bed, venous plethora, constriction of precapillaries and restriction of capillary blood flow. After endovascular angioplasty of the affected artery and restoration of blood flow therein the patients of the examined subgroups demonstrated an equal increase in the ankle-brachial index, thus approaching the normal values; the patients of both subgroups reported disappearance of pain in the legs during usual daily activities. In patients without DM, endovascular intervention was accompanied by a decrease in the intensity of the arteriole-venule shunts, venous plethora, and enhancement of capillary blood flow. The patients with DM at the early stage after restoration of blood flow in the limb were found to have no statistically significant shifts of the functional parameters of the microvascular bed. CONCLUSION: From the point of view of microcirculatory transformations in patients with IC and DM, the effect of limb revascularization at early stages of follow-up turned out to be incomplete, which, probably, was due to irremovable events of latent diabetic microangiopathy and neuropathy.

[The nature of a microcirculatory change in hypertensive patients during increased blood pressure].

AIM: To evaluate changes in the microcirculation (MC) of hypertensive patients during increased blood pressure (BP). SUBJECTS AND METHODS: The investigation enrolled 66 patients with grades 2-3 hypertension and 57 apparently healthy individuals. After 2-day discontinuation of antihypertensive drugs, the patients were divided into 2 groups: (1) BP < or = 140/90 mm Hg; (2) BP > or = 160/100 mm Hg. MC was examined by laser Doppler flowmetry. RESULTS: In the hypertensive patients, the episodes of higher BP are accompanied by the constriction of meta-arterioles and precapillaries, resulting in diminished capillary blood flow. A compensatory increase in pulse blood filling is attended by accelerated blood flow with decreased vessel diameters and increased shear stress. This creates conditions for the endothelial release of vasodilator mediators. However, the limited reserves of an endothelial relaxing effect are not enough to normalize BP. This resultant increase in tissue hemoperfusion is nonproductive since it is due to intensified shunt blood flow and venous plethora. CONCLUSION: Severe MC disorders in hypertensive patients with increased BP are characterized by incompetent compensatory mechanisms, reduced endothelial relaxing potential, and depressed capillary tissue diffusion. It may be believed that these disorders appreciably determine target organ involvements in hypertension.

[Variability of the response of the microvascular bed to medicamental vasodilation in patients with arterial hypertension].

The aim of the work was to estimate changes of microcirculation (MC) in patients with arterial hypertension (AH) with different types of peripheral hemocirculation in response to a single intake of corinfar. The study included 45 patients (mean age 54.3 +/- 1.1 yr) with grade 2-3 AH. MC in the forearm skin was evaluated by laser Doppler flowmetry before and 2 hr after sublingual administration of corinfar (20 mg). The response was found to depend on the initial character of MC. 40% of the patients underwent positive changes characterized by reduced constriction of microvessels, increased capillary bloodflow and its reserve potential, improved venous outflow suggesting productive growth of tissue perfusion. Corinfar caused dyscoordination of MC regulation and reduction of tissue hemoperfusion in each 5th (22.2%) patient. These data suggest different functional reaction of MC to the treatment of AH and its varying organoprotective effect.

[Effect of omega-3 fatty acids on the serum lipid profile and microcirculation in patients with metabolic syndrome and hypertensive disease].

The aim of the study was to assess effect of omega-3 polyunsaturated fatty acids (PUFAs) on clinical manifestations of metabolic syndrome (MS) and microcirculation in patients with arterial hypertension (AH). 22 patients of the 32 with grade 2 AH and MC symptoms (by ATP III criteria) were given 1.5 mg of omega-3 PUFAs for 1 months. The control group comprised 10 patients. Serum lipid profile was detected and forearm skin microcirculation evaluated by laser Doppler flowmetry. Therapy with omega-3 PUFAs resulted in a significant decrease of serum triglycerides from 3.04 +/- 0.39 to 1.91 +/- 0.15 mmol/l (-37.2%). Its combination with hypotensive therapy reduced mean AP from 114.5 +/- 2.4 to 106.3 +/- 1.8 mm Hg (p < 0.01). Also, omega-3 PUFAs increased amplitude fluctuations in LDF-grams in endothelial and neurogenic ranges by 33.3 and 30.8% respectively, tissue hemoperfusion rate from 4.9 +/- 0.13 to 5.3 +/- 0.15 U (p < 0.05), capillary blood flow reserve by 13.7% (p < 0.05), maximum tissue hemoperfusion by 18.8% (p < 0.01), and coefficient of variation of tissue blood flow by 26.9%. Blood C-reactive protein level dropped by 40.7%. These changes were absent in control patients. It is concluded that correction of omega-3 PUFAs deficiency in patients with HA and MS reduces hyperlipidemia, has moderate antihypertensive effect, improves endothelial function and microcirculation. Multifunctional action of omega-3 PUFAs gives reason to recommend them for the treatment of MS.

Quantum-dot-based saturable absorber for femtosecond mode-locked operation of a solid-state laser.

A quantum-dot-based saturable absorber has been demonstrated to initiate the generation of femtosecond pulses from a passively mode-locked solid-state laser. Control and tuning of the pulse duration from 58 ps to 158 fs was achieved. The 158 fs transform-limited pulses at 1280 nm are the shortest pulses that were produced from the Cr:forsterite laser passively mode locked by an InAs/InGaAs quantum-dot semiconductor saturable absorber mirror.

[Laser correction of microcirculation disorders in patients having CHD with hypercholesterinemia].

The study demonstrates that hypercholesterinemia in patients with coronary heart disease (CHD) is associated with functional depression of microcirculation, increase in total peripheral vascular resistance, reduction in the functional efficiency of heart and decrease in activity tolerance. After receiving a course of low-intensity infrared laser radiation treatment the patients displayed positive changes in blood lipid spectrum, which was associated with improvement in microcirculation, decrease in afterload, increase in economization of heart functioning and activity tolerance. The obtained results demonstrate that the hypolipidemic effect of laser radiation is a substantial factor in the regression of CHD manifestations.

[Aerobic and hemodynamic mechanisms of the antianginal effect of drugs in patients with angina pectoris]. / Aérobno-gemodinamicheskie mekhanizmy antianginal'nogo éffekta lekarstvennykh preparatov u bol'nykh stenokardiei.

Paired bicycle ergometric tests were performed to study the basic features of the aerobic hemodynamic mechanism of antianginal effects of reference representatives of the major classes of antianginal drugs (AADs) (nitrosorbide, corinfar, propranolol) in 54 patients with Functional Classes II-IV angina pectoris (AP). Oxygen consumption and central hemodynamic parameters were studied during exercise. The efficiency of a single administration of the drugs was 53-62%. In the context of the whole organism, AADs increased exercise tolerance in patients with AP, by optimizing oxygen-supplying processes: by reducing oxygen uptake, on the one hand, and by improving oxygen delivery to working organs, on the other. In so doing, corinfar-induced activation of the oxygen-transporting system resulted from the higher hemodynamic productivity; propanolol enhanced hemodynamic effectiveness, nitrosorbide showed a combination of both effects.

[Cardiometabolic therapy of ischemic heart disease]. / Kardiometabolicheskaia terapiia IBS.

A total of 59 patients suffering from ischemic heart disease with effort angina (functional classes II-IV) entered the study. Of them, 29 patients received antianginal drugs and 10-day courses of a combination of drugs with membran-oprotective properties (MPD); 30 patients received antianginal drugs alone. Blood levels of lipid peroxidation products, lipid structure of erythrocytic membrane, exercise tolerance were studied before and after the treatment. MPD therapy was associated with lower activity of lipid peroxidation, stabilization of cell membrane structure and greater exercise tolerance due to more effective cardiac performance.

[Efficacy of laser therapy in patients with ischemic heart disease]. / Effektivnost' lazeroterapii bol'nykh ishemicheskoi bolezn'iu serdtsa.

Modification of erythrocytic membrane and the trend in clinicofunctional indices were studied in 93 patients with angina of effort (FC i-IV) in the course of treatment with laser radiation (group 1) and imitation of laser radiation (group 2). In patients of group 1 the treatment resulted in stabilization of cell membrane accompanied with positive cardiodynamic changes.

[Clinico-functional efficacy of medicinal and photon stabilization of cell membrane in patients with angina pectoris]. / Kliniko-funktsional'naia éffektivnost' medikamentoznoi i kvantovoi stabilizatsii kletochnoi membrany u bol'nykh stenokardiei.

Modification of erythrocytic membrane and the trend in clinicofunctional indices were studied in 90 patients with angina of effort (FC I-IV) in the course of treatment with a combination of membranoprotective drugs (group 1), magneto-laser radiation (group 2) and imitation of laser radiation (group 3). In patients of groups 1 and 2 the treatment resulted in stabilization of cell membrane accompanied with a hypotensive effect and increased exercise tolerance due to more effective cardiac performance.

[Effect of membrane-stabilizing magnetolaser therapy on cardiodynamics in patients with ischemic heart disease]. / Vliianie membranostabiliziruiushchei magnitolazernoi terapii na kardiodinamiku u bol'nykh ishemicheskoi bolezn'iu serdtsa.

AIM: To evaluate cardiodynamic changes in response to magnetolaser therapy (MLT) and these changes links with lipid shifts in cell membrane. MATERIAL AND METHODS: The study enrolled 50 patients with effort angina (functional class II-III). Of them, 37 patients were exposed to 10-day courses of MLT, 13 patients were exposed to sham procedures. Before the treatment and 3 months after it measurements were made of lipid peroxidation (LPO) products, structure of erythrocytic membrane and cardiodynamic parameters. RESULTS: MLT resulted in a significant reduction of LPO products, stabilization of cell membrane structure and positive shifts in cardiodynamics. Correlation was found between the above parameters. CONCLUSION: Improvement of inotropic, diastolic functions of the myocardium and abatement of cardiac remodeling in coronary heart disease patients in response to MLT is realized primarily due to structural stabilization of cell membrane lipid biolayer.

[Status of microcirculation and cardiodynamics in ischemic heart disease patients with decreased left ventricular fraction and their response to carvedilol]. / Sostoianie mikrotsirkuliatsii i kardiodinamiki u bol'nykh ishemicheskoi bolezn'iu serdtsa so snizhennoi fraktsiei vybrosa levogo zheludochka i ikh izmenenie pod vliianiem karvedilola.

AIM: Assessment of microcirculation in IHD patients at preclinical stage or in those with initial symptoms of cardiac failure, clarification of relationship between parameters of microcirculation and cardiodynamics. MATERIAL AND METHODS: A blind cross-over trial was made to compare skin microcirculation and cardiodynamic parameters in response to a short carvedilol course and beta-blocker anaprilin in 40 patients with ischemic heart disease with angina of effort (NYHA class I-IV, ejection fraction under 45%). RESULTS: IHD with initial symptoms of cardiac failure had a congestion-spastic type of microcirculation defect. Microcirculatory picture and cardiodynamics were related. CONCLUSION: Compared to anaprilin therapy, treatment with carvedilol enhanced capillary blood flow and improved cardiodynamics.

[Antioxidant and antiarrhythmic activity of carvedilol in patients with ischemic heart disease. Comparison with anaprilin]. / Antioksidantnaia i antiaritmicheskaia aktivnost' karvedilola u bol'nykh ishemicheskoi bolezn'iu serdtsa.

AIM: To examine antioxidant and antiarrhythmic activity of carvedilol vs that of standard beta-blocker anaprilin in coronary patients with low left ventricular ejection fraction (LVEF). MATERIAL AND METHODS: The cross-over trial enrolled 50 coronary male patients with LVEF under 45%. Before and after treatment with carvedilol and anaprilin, measurements were made of blood dienic conjugates and malonic dialdehyde, 24-h ECG monitoring was performed. RESULTS: The antioxidant activity of antiarrhythmic effect of carvedilol was significantly higher than that of anaprilin. A correlation was discovered between the number of extrasystoles and blood levels of dienic conjugates. CONCLUSION: Marked antioxidant activity of carvedilol as well as reduced myocardial energy consumption resultant from hemodynamic cardiac unloading due to block of alpha-adrenoreceptors contribute to carvedilol additional antiarrhythmic effect.

[A possible mechanism of the hypotensive effect of laser irradiation in patients with ischemic heart disease with arterial hypertension]. / O vozmozhnom mekhanizme gipotenzivnogo éffekta lazernogo izlucheniia u bol'nykh ishemicheskoi bolezn'iu serdtsa s arterial'noi gipertenziei.

93 patients with ischemic heart disease, 44(47.3%) of them with arterial hypertension, were exposed to laser irradiation (LI). LI was accompanied with lowering of arterial pressure, more prominent in hypertensive patients. Mechanism of the hypotensive effect of laser therapy operates largely through stabilization of the lipid bilayer of the cell membrane demonstrated on the model of erythrocyte.