Correlation of cutaneous blood microcirculation parameters with biological age in diabetic patients

Известно, что с возрастом и при ряде хронических заболеваний происходит снижение реактивности микроциркуляторного звена кровообращения. Целью данного исследования стала оценка взаимосвязи параметров кожной микроциркуляции с биологическим и хронологическим возрастом у пациентов с сахарным диабетом. В исследование были включены 11 человек с сахарным диабетом [медиана возраста 57 (51; 64) лет]; биологический возраст определяли с помощью калькулятора Aging.AI. Показатели кожной микроциркуляции оценивали с помощью метода лазерной допплеровской флоуметрии в ходе окклюзионно-теплового теста. Для анализа взаимосвязи количественных параметров рассчитывали коэффициенты ранговой корреляции Спирмена. Были выявлены значимые множественные отрицательные корреляции биологического возраста с показателями реактивности микрососудов как при тепловом, так и при окклюзионном воздействии (сила корреляций от -0,618 до -0,97, p<0,05). У лиц с сахарным диабетом снижение реактивности микрососудов в большей мере ассоциировано с биологическим возрастом, чем с хронологическим. It has been established that the age together with the number of chronic diseases cause the decrease of the reactivity of the microcirculatory bed. This study aims to evaluate the relationship between cutaneous microcirculation parameters and biological and chronological age of patients with diabetes mellitus. 11 diabetic patients (median age 57 (51; 64) years) were examined in course of this study; biological age was figured by Aging.AI calculator. Cutaneous microcirculation parameters were measured by laser Doppler flowmetry with an occlusion-heating test. Spearman’s rank correlation coefficients were calculated to analyze the relationships between quantitative parameters. Significant multiple negative correlations of biological age and microvascular reactivity indices on exposure to both heat and occlusion (correlation strength from -0,618, to -0,97, p<0,05) were found. Diabetic patients have decreased microvascular reactivity that is more associated with biological age than with chronological age.

Energy Performance Analysis of B1-3.5mm Burner Model of Fasobio-15 Biodigester Biogas Cookstoves

In Burkina Faso, finding wood for cooking is still a headache for rural households due to the advancing desert. Here, we try to bring a new way for farmers who already have a biodigester and convince those who are reluctant to adopt this work to reduce their dependence on wood. For this purpose, a characterization of the energy performance of biogas stoves is carried out based on the three-phase water heating test protocol called Water Boiling Test (WBT). The fuel used in the study is the biogas produced by a batch biodigester fed with pig manure. The analysis of the produced biogas shows a methane content of 60% and maximum hydrogen sulfide of 400ppm. The heat balance shows a loss of 11% in the walls of the cookstove and about 36% in the flue gas. Thus the energy performance of the furnace is estimated at 53%, a combustion rate of 6.4 L /min and the average boiling time is 50 minutes. Given these results, we suggest that households use biogas fuel and the B1-3.5mm burner in the cookstove as a replacement for the other burners. We intend to carry out a controlled cooking test on this stove, a modeling of the biogas production and its consumption in this type of burner.

Assessment of the heat loss coefficient of a renovated historical dwelling using a co-heating test

Twelve quasi-identical almshouses with an architectural-historic value were reno-vated, because of their high energy use, poor indoor comfort and numerous moisture problems. Aerogel plaster was applied for the hygrothermal upgrade of the uninsulated brick walls, while limiting the reduction of living space in these very small houses and keeping the monumental character of the facades in their original state. Several quality assurance tests were executed to evaluate the quality of the renovation of the building envelope and to compare the results with the initial theoretical design calculations. It appeared that the existing materials performed considerably better than the assumed conservative default values. On the other hand, the newly installed insulation materials performed somewhat less than declared, for example due to on-site processing. This resulted in a strong overestimation of the improvement in thermal performance by the renovation works. Field measurements of the existing situation can help to close this gap.

Upaya Pemurnian Landfill Biogas Menggunakan Metode Adsroben Steel Wool

Nilai kalor yang dimiliki oleh biogas sangat mempengaruhi lamanya waktu proses pembakaran. Beberapa penelitian telah dilakukan untuk meningkatkan nilai kalor yaitu dengan menurunkan kadar zat pengotor yang terkandung bersama biogas. Dalam penelitian ini dilakukan upaya peningkatan nilai kalor biogas dengan menggunakan steel wool sebagai adsorben dengan variasi massa steel wool (500 gram dan 600 gram) dan variasi laju aliran biogas (1 lpm, 2 lpm, dan 3 lpm). Peningkatan nilai kalor biogas sebelum dan sesudah pemurnian ditentukan dengan water heating test. Hasil penelitian menunjukan peningkatan nilai kalor diperoleh pada filter dengan massa adsorben 600 gr dan laju aliran biogas 1 lpm, dimana nilai kalor meningkat sebesar 36.19%. Sedangkan filter dengan 500 gr steel wool adsroben dan laju aliran biogas 3 lpm, menghasilkan peningkatan nilai kalor terendah yaitu sebesar 4.46%. Hasil eksperimen menunjukan peningkatan nilai kalor semakin tinggi jika laju aliran biogas makin rendah melalui kolom adsorben dengan massa steel wool yang semakin tinggi.

Reduced microvascular reactivity in patients with diabetic neuropathy

BACKGROUND: Neurogenic regulation is involved in the development of microcirculation response to local heating. We suggest that microvascular reactivity can be used to estimate the severity of diabetic polyneuropathy (DPN). OBJECTIVE: To evaluate the prospects for using the parameters of skin microvascular reactivity to determine the severity of DPN. METHODS: 26 patients with diabetes mellitus were included in the study (patients with retinopathy (n = 15), and without retinopathy (n = 11)). The severity of DPN was assessed using Michigan Neuropathy Screening Instrument (MNSI) and Norfolk QOL-DN (NQOLDN). Skin microcirculation was measured by laser Doppler flowmetry with local heating test. RESULTS: There were revealed moderate negative correlations between microvascular reactivity and the severity of DPN (for MNSI (Rs = –0.430), for NQOLDN (Rs = –0.396)). In patients with retinopathy, correlations were stronger than in the general group (for MNSI (Rs = –0.770) and NQOLDN (Rs = –0.636)). No such correlations were found in patients without retinopathy. CONCLUSION: Correlation of the microvascular reactivity and DPN was revealed in patients with registered structural disorders in microvessels (retinopathy). The lack of such correlation in patients without retinopathy may be explained by the intact compensatory mechanisms of microvessels without severe disorders.