This work focuses on the effectiveness of using four-wave mixing (FWM) in restoring the corrupted signal as well as the factors that affect the quality of the data. The method was based on the two-stage FWM-based optical wavelength converter designed using a OptiSystem version 18.0. The signal regeneration for both stages has taken place in the highly nonlinear fiber (HNLF) having length of 1.0 km and 0.8 km respectively. The first stage is to convert and restore a signal carrying NRZ formatted data at 1552 nm into a new wavelength of 1548 nm. While the second stage is to transfer the data back into the original wavelength of 1552 nm. It has been found that the quality of the data (Q-factor) is affected by the power of modulated signal (1552 nm) as well as the power of unmodulated pump source (1550 nm). The maximum Q-factor of 29.6 at 6 dBm signal power and of 35.7 at 16 dBm pump power have been achieved here. The wavelength spacing between those two sources also affect the quality of regenerated signal. The optimum quality value is found to be above 25 when the spacing is 1 nm regardless of the signal and pump power values.

A BSTRACT Introduction: Approach to managing infection in the intensive care unit (ICU) often varies between institutions and not many readily adapt to available local guidelines despite it was constructed to suite local clinical scenario. Malaysia already has two published guidelines on managing infection in the ICU but data on its compliance are largely unknown. Objectives: A cross-sectional survey was carried out and sent to a total of 868 specialists working primarily in the ICU. The aim of this study was to explore knowledge, perception, and the antibiotic prescribing practice among specialists and advanced trainees in Malaysian ICU. Materials and Methods: A cross-sectional survey was used, consisted of three sections: knowledge, perception, and antibiotic prescribing practice in ICU. Three case vignettes on hospital-acquired pneumonia (HAP), infected necrotizing pancreatitis (INP), and catheter-related bloodstream infection (CRBSI) were used to explore antibiotic prescribing practice. Results: A total of 868 eligible subjects were approached with 104 responded to the survey. Three hundred eighty-nine antibiotics were chosen from seven different classes in the case vignettes. All respondents acknowledged the importance of pharmacokinetic/pharmacodynamic (PK/PD) in antibiotic optimization and majority (97.2%) perceived that current dosing is inadequate to achieve optimal PK/PD target in ICU patients. Majority (85.6%) believed that antibiotic dose should be streamlined to the organisms’ minimum inhibitory concentration (MIC). In terms of knowledge, only 64.4% provided the correct correlations between antibiotics and their respective PK/PD targets. Compliance rates in terms of antibiotic choices were at 79.8%, 77.8%, and 27.9% for HAI, INP, and CRBSI, respectively. Conclusion: Malaysian physicians are receptive to use PK/PD approach to optimize antibiotic dosing in ICU patients. Nonetheless, there are still gaps in the knowledge of antibiotic PK/PD as well as its application in the critically ill, especially for β-lactams.

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