Hybrid power control for multi-carrier systems

Uplink conventional power control techniques in systems with frequency reuse one have some limitations, typically regarding the tradeoff between the average throughput of users at cell center and cell edge. Moreover, one of the main drawbacks is the excess use of power. From our point of view, one of the reasons for this waste of power is the practice of giving all the users in the cell the same target SINR in the power control process. Since there exists a rate limit for users in the cell, depending on their positions, a Hybrid Power Control (HPC) technique is introduced here in order to overcome these limitations and provide a more flexible solution. The HPC uses power control with at least two different types of setup and the rate limit of the cell users is respected. Moreover, this HPC method shows a significant reduction in the average cell transmission power, satisfactory cell edge users performance and an improvement in the overall cell rate, around 25%. Moreover, the average transmitted power is reduced by more than 20 dB

Pancreatic surgery outcomes: multicentre prospective snapshot study in 67 countries

Background: Pancreatic surgery remains associated with high morbidity rates. Although postoperative mortality appears to have improved with specialization, the outcomes reported in the literature reflect the activity of highly specialized centres. The aim of this study was to evaluate the outcomes following pancreatic surgery worldwide.Methods: This was an international, prospective, multicentre, cross-sectional snapshot study of consecutive patients undergoing pancreatic operations worldwide in a 3-month interval in 2021. The primary outcome was postoperative mortality within 90 days of surgery. Multivariable logistic regression was used to explore relationships with Human Development Index (HDI) and other parameters.Results: A total of 4223 patients from 67 countries were analysed. A complication of any severity was detected in 68.7 percent of patients (2901 of 4223). Major complication rates (Clavien-Dindo grade at least IIIa) were 24, 18, and 27 percent, and mortality rates were 10, 5, and 5 per cent in low-to-middle-, high-, and very high-HDI countries respectively. The 90-day postoperative mortality rate was 5.4 per cent (229 of 4223) overall, but was significantly higher in the low-to-middle-HDI group (adjusted OR 2.88, 95 per cent c.i. 1.80 to 4.48). The overall failure-to-rescue rate was 21 percent; however, it was 41 per cent in low-to-middle-compared with 19 per cent in very high-HDI countries.Conclusion: Excess mortality in low-to-middle-HDI countries could be attributable to failure to rescue of patients from severe complications. The authors call for a collaborative response from international and regional associations of pancreatic surgeons to address management related to death from postoperative complications to tackle the global disparities in the outcomes of pancreatic surgery (NCT04652271; ISRCTN95140761)