Objectives We sought to determine the prevalence, pattern of causative organisms, and mortality of newborns with culture-proven late-onset sepsis (LOS) and to determine and compare the risk factors linked to late-onset gram-positive and late-onset gram-negative sepsis in Sultan Qaboos University Hospital (SQUH). Methods We conducted a cross-sectional retrospective study of data obtained between 1 January 2007 and 31 December 2014 (eight years) from infants in the neonatal intensive care unit (NICU) at SQUH. Infants born in SQUH (inborn) and other institutions (outborn) with positive blood cultures were included in the study. Results The total number of live births and admissions during the study period were 26 289 and 3559, respectively. The total number of infants identified with LOS were 125 of whom 69 (55.2%) were gram-positive, 52 (41.6%) were gram-negative, and four (3.2%) were due to Candida species (spp.). The majority of infants (n = 113, 90.4%) were inborn; 69 (55.2%) were males and 56 (44.8%) were females. The prevalence of LOS among inborn admissions was 4.3 per 1000 live births. Most infections occurred in very low birth weight infants (n = 81, 64.8%). Eleven (8.8%) infants died due to gram-negative sepsis. Klebsiella pneumoniae followed by Pseudomonas aeruginosa were the leading cause of death. Maternal intrapartum antibiotics were the only independent risk factor correlating with gram-negative organisms in multivariate analysis ( p = 0.003). Conclusions LOS poses a burden in the NICU, which could be due to the increasing survival of premature babies. The main contributing organisms to LOS are gram-positive bacteria. Klebsiella spp. is a major cause of mortality in LOS. The use of intrapartum antibiotic prophylaxis in mothers might explain the positive correlation of maternal antibiotics as a risk factor with gram-negative infections.

Renewable energy resources become the best way to solve the issues created by traditional power resources in terms of environmental effects, energy cost reduction, and high-power demand. The hybrid-based system gives a realistic economic solution where grid extension is non-feasible especially for remote areas. The main objective of this study is to determine the optimum size of a hybrid-based system to fulfill the requirements of remote sites located in the Hasik area in the southern part of Oman. The work is carried out using HOMER Pro and MATLAB software. The proposed hybrid system in Hasik network is a combination of PV systems with existing diesel generation. Real load data as well as solar radiations were utilized in proposed model. HOMER selected an optimum solution for the hybrid system resulting in a combination of 2,500 kW PV system and 3,100 kW diesel generation as well as providing a reduction in the cost of energy and CO2 emission by 13% and 22% respectively. The optimum PV sizing for the hybrid system was determined using genetic algorithm tool in MATLAB. The optimization was based on reducing the system power losses, improving the voltage profile and minimizing cost. Optimization verification was done using load flow analysis by MATLAB to determine the PV sizing effects on the system power losses and voltage profile. Based on the model results, the hybrid system is feasible in the Hasik area.

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