RESUMO
BACKGROUND: The mortality rate of afebrile bacteremia has been reported to be as high as 45%. This investigation focused on the risk factors and predictive performance of scoring systems for the clinical outcomes of afebrile patients with monomicrobial gram-negative bacteria (GNB) in the emergency department (ED). METHODS: We conducted a retrospective analysis of afebrile adult ED patients with monomicrobial GNB bacteremia from January 2012 to December 2021. We dissected the demographics, clinical pictures, and laboratory investigations. We applied five scoring systems and three revised systems to predict the clinical outcomes. RESULTS: There were 600 patients included (358 males and 242 females), with a mean age of 69.6 ± 15.4 years. The overall mortality rate was 50.17%, reaching 68.52% (74/108) in cirrhotic patients. Escherichia coli was the leading pathogen (42.83%). The non-survivors had higher scores of the original MEDS (p < 0.001), NEWS (p < 0.001), MEWS (p < 0.001), qSOFA (p < 0.001), and REMS (p = 0.030). In univariate logistic regression analyses, several risk factors had a higher odds ratio (OR) for mortality, including liver cirrhosis (OR 2.541, p < 0.001), malignancy (OR 2.259, p < 0.001), septic shock (OR 2.077, p = 0.002), and male gender (OR 0.535, p < 0.001). The MEDS demonstrated that the best predictive power with the maximum area under the curve (AUC) was measured at 0.773 at the cut-off point of 11. The AUCs of the original NEWS, MEWS, qSOFA, and REMS were 0.663, 0.584, 0.572, and 0.553, respectively. We revised the original MEDS, NEWS, and qSOFA by adding red cell distribution width, albumin, and lactate scores and found a better predictive power of the AUC of 0.797, 0.719, and 0.694 on the revised MEDS ≥11, revised qSOFA ≥ 3, and revised NEWS ≥ 6, respectively. CONCLUSIONS: The original MEDS, revised MEDS, revised qSOFA, and revised NEWS were valuable tools for predicting the mortality risk in afebrile patients with monomicrobial GNB bacteremia. We suggested that clinicians should explore patients with the risk factors mentioned above for possible severe infection, even in the absence of fever and initiate hemodynamic support and early adequate antibiotic therapy in patients with higher scores of the original MEDS (≥11), revised MEDS (≥11), revised NEWS (≥6), and revised qSOFA (≥3).
RESUMO
In this work, surface plasmons (SPs) on a germanium (Ge) thin film in terahertz (THz) region that are excited by electron cyclotron motion (ECM) and the subsequent SP emission (SPE) by adding Ge gratings on the film are explored by finite-difference time-domain (FDTD) and particle-in-cell FDTD (PIC-FDTD) simulations. The optical properties of ECM-excited SPs are the same as those of SPs that are excited by electron straight motion (ESM). For operating at the flat band of SPs' dispersion curve on the Ge film, changing the electron energy will only change the wavevector of SPs and hence the number of periods of SPs on the circular orbital. When the periodic gratings are deposited on the Ge film along the circular orbital of electrons, the emitted SPE contains the orbital angular momentum (OAM). The number of arms and chirality of the spiral patterns in phase map (i.e. the quantum number of OAM) of SPE are determined by the difference between the number of SPs' periods and the number of gratings. Manipulations of the quantum number of OAM by changing the number of gratings for a fixed electron energy and by changing the electron energy for a fixed number of gratings are also demonstrated. This work provides an active OAM source and it is not required to launch circularly polarized beams or pumping beams into the structure.