Применение торакоскопического трансдиафрагмального доступа для резекции VIII сегмента печени на одном из этапов комбинированного лечения у больной с метастазом колоректального рака в печени. Клиническое наблюдение

The article presents a rare case report about the use of thoracoscopic transdiaphragmatic approach to resection of a solitary segment VIII metastasis in the liver (1.5 × 1.2 cm). Taking into account the difficulty of laparoscopic resection of postero ‑superior segments of the liver, a decision was made to refrain from laparotomy and to perform a safe minimally invasive surgery using an approach, which is rare at the current stage. The article also presents the analysis of published literature and discussion of a non‑ standard approach in this clinical case.В данной статье представлено редкое клиническое наблюдение, где был применен торакоскопический трансдиафрагмальный доступ для удаления солитарного метастаза колоректального рака в VIII сегменте печени размерами 1,5 × 1,2 см. С учетом сложности выполнения лапароскопических резекций задне-верхних сегментов печени, решено воздержаться от лапаротомии, и больной предложено выполнить безопасное малоинвазивное вмешательство редким на современном этапе доступом. В статье также приводится анализ литературных данных и обсуждение ввиду нестандартного подхода в этом клиническом случае

Research and Analysis of Investment and Construction Activities in the Republic of Uzbekistan

The purpose of this article is to identify scientific and practical recommendations for enhancing and improving the efficiency of investment and construction activities carried out in the Republic of Uzbekistan. The paper also provides an assessment of positive and negative factors affecting the efficiency of investment and construction activities and a number of recommendations for improving the use of the production potential of construction organizations in the investment field

MATHEMATICAL MIXER MODEL WITH FORMATION OF HETERODYNE ANTIPHASE SIGNAL

Objectives To carry out calculations involved in the design of a microwave mixer with a diplexer with the formation of the antiphase heterodyne signal using a slot resonator.Method In order to calculate and optimise the characteristics, design and topological parameters of microwave mixers, the results of the design bandpass filter  PF and low-pass filter (LPF) mixers of through-feed type were used. The characteristics of mixers and their structural elements were calculated using the Serenade software package intended for the automated calculation of microwave devices. A distinct feature of designing mixers (with a diplexer) involves the need to optimise the topology of the diplexer before optimising the mixer characteristics.Results The characteristics of nonlinear distortions show that the maximum power level at the mixer inlet should not exceed -15 – -20 dBm. In order to attenuate the intermodulation distortions of the 3rd order, this level should be higher that 50 dBs. The relatively low level of compression and suppression of harmonic and intermodulation distortions associated with the minimisation of the heterodyne power level at the calculation of characteristics of mixers of the required heterodyne power level (Rh ~ 5-7 dBm) is due to the minimum expenses at the realisation of sources of heterodyne signals. A noticeable improvement in the characteristics of mixers by nonlinear distortions can be achieved by shifting the operating point at the points on the current-voltage characteristic (VAC) diodes by an external voltage source with a simultaneous increase in Ph by several dB (up to Ph = 10 dBm).Conclusion A mode of increased nonlinear distortion suppression can be practically realised by switching on diodes through resistive-capacitive circuits (auto-shift) or using diodes with an increased potential barrier. The calculation shows that it is possible to realise sufficiently small conversion losses of 6.6-8.0 dB at low levels of Rh ~ 5-7 dBm

Research and Analysis of Investment and Construction Activities in the Republic of Uzbekistan

The purpose of this article is to identify scientific and practical recommendations for enhancing and improving the efficiency of investment and construction activities carried out in the Republic of Uzbekistan. The paper also provides an assessment of positive and negative factors affecting the efficiency of investment and construction activities and a number of recommendations for improving the use of the production potential of construction organizations in the investment field