Источник бесперебойного питания для телекоммуникационного оборудования

Телекоммуникационное оборудование очень важно в наши дни. Все чаще встречается необходимость его бесперебойной работы в современном мире Разработан источник бесперебойного питания, работающий в трехфазной цепи. Показана необходимость построения источников бесперебойного питания телекоммуникационного оборудования для обеспечения его нормальной работы. Выполнен анализ принципов построения источника бесперебойного питания для ответственных потребителей электрической энергии. Осуществлен выбор функциональной схемы электропитания телекоммуникационного оборудования. Выполнен расчет и выбор основных элементов сети электропитания узла связи. Представлено компьютерное моделирование работы выпрямителя в составе ИБП.Telecommutation equipment is very important these days. More and more often there is a need for its uninterrupted work in the modern world  An uninterruptible power supply has been developed that operates in a three-phase circuit. The need to build uninterruptible power supplies for telecommunications equipment is shown to ensure its normal operation. The analysis of the principles of construction of an uninterruptible power supply for responsible consumers of electrical energy is performed. The functional scheme of power supply of telecommunication equipment has been selected. The calculation and selection of the main elements of the power supply network of the communication center have been performed. A computer simulation of rectifier operation in the UPS is presented

Patients with IgA nephropathy exhibit high systemic PDGF-DD levels

BACKGROUND: Platelet-derived growth factor (PDGF) is a central mediator of mesangioproliferative glomerulonephritis (GN). In experimental mesangioproliferative GN, PDGF-DD serum levels, unlike PDGF-BB, increased up to 1000-fold. METHODS: We assessed disease activity in 72 patients with GN, established a novel PDGF-D ELISA and then determined their PDGF-DD levels. In parallel, we studied renal PDGF-DD mRNA expression by RT-PCR. RESULTS: PDGF-DD serum levels in patients with IgA nephropathy (IgAN) were significantly higher (1.67 +/- 0.45 ng/ml) and in patients with lupus nephritis significantly lower (0.66 +/- 0.86 ng/ml) compared to healthy controls (1.17 +/- 0.46 ng/ml), while patients with focal segmental glomerulosclerosis, membranous GN and ANCA-positive vasculitis did not differ from controls. The subgroup of IgAN patients with elevated PDGF-DD levels (27% of samples) did not differ in their clinical features from those with normal PDGF-DD levels. In IgAN patients with repetitive PDGF-DD determinations, most exhibited only minor fluctuations of serum levels over time. Intrarenal PDGF-DD mRNA expression did not differ between controls and patients, suggesting an extrarenal source of the elevated PDGF-DD in IgAN. CONCLUSIONS: Serum PDGF-DD levels were specifically elevated in patients with IgAN, in particular in those with early disease, i.e. preserved renal function. Our data support the rationale for anti-PDGF-DD therapy in mesangioproliferative GN