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OBJECTIVES: This study aimed to conduct a comprehensive and updated systematic review with network meta-analysis (NMA) to assess the outcome benefits of various blood purification modalities for adult patients with severe infection or sepsis. DATA SOURCES: We conducted a search of PubMed, MEDLINE, clinical trial registries, Cochrane Library, and Embase databases with no language restrictions. STUDY SELECTION: Only randomized controlled trials (RCTs) were selected. DATA EXTRACTION: The primary outcome was overall mortality. The secondary outcomes were the length of mechanical ventilation (MV) days and ICU stay, incidence of acute kidney injury (AKI), and kidney replacement therapy requirement. DATA SYNTHESIS: We included a total of 60 RCTs with 4,595 participants, comparing 16 blood purification modalities with 17 interventions. Polymyxin-B hemoperfusion (relative risk [RR]: 0.70; 95% CI, 0.57–0.86) and plasma exchange (RR: 0.61; 95% CI, 0.42–0.91) were associated with low mortality (very low and low certainty of evidence, respectively). Because of the presence of high clinical heterogeneity and intransitivity, the potential benefit of polymyxin-B hemoperfusion remained inconclusive. The analysis of secondary outcomes was limited by the scarcity of available studies. HA330 with high-volume continuous venovenous hemofiltration (CVVH), HA330, and standard-volume CVVH were associated with shorter ICU stay. HA330 with high-volume CVVH, HA330, and standard-volume CVVH were beneficial in reducing MV days. None of the interventions showed a significant reduction in the incidence of AKI or the need for kidney replacement therapy. CONCLUSIONS: Our NMA suggests that plasma exchange and polymyxin-B hemoperfusion may provide potential benefits for adult patients with severe infection or sepsis/septic shock when compared with standard care alone, but most comparisons were based on low or very low certainty evidence. The therapeutic effect of polymyxin-B hemoperfusion remains uncertain. Further RCTs are required to identify the specific patient population that may benefit from extracorporeal blood purification. [ABSTRACT FROM AUTHOR]

N2O is a significant atmospheric greenhouse gas that contributes to global warming and climate change. In this work, the high sensitivity detection of atmospheric N2O is achieved using wavelength modulation spectroscopy (WMS) with an inter-band cascade laser operating around 3.939 µm. A LabVIEW-based software signal generator and software lock-in amplifiers are designed to simplify the system. In order to eliminate the interference from water vapor, the detection was performed at a pressure of 0.1 atm (1 atm = 1.01325×105 Pa) and a drying tube was added to the system. To improve the system performance for long term detection, a novel frequency locking method and 2 f/1 f calibration-free method were employed to lock the laser frequency and calibrate the power fluctuations, respectively. The Allan deviation analysis of the results indicates a detection limit of ∼ 20 ppb (1 ppb = 1.81205 µg/m3) for a 1 s integration time, and the optimal detection limit is ∼ 5 ppb for a 40-s integration time. [ABSTRACT FROM AUTHOR]

Sub-ppmv level detection of hydrogen sulphide (H2S) using a 1.578- distributed feedback tunable diode laser combining with wavelength modulation spectroscopy and second harmonic detection scheme is reported. A home-developed novel compact dense-pattern multipass gas cell with an effective optical path length of 29.37 m is used to improve sensitivity and reduce sample volume. Detection parameters are optimized, including modulation frequency and amplitude. The analysis of Allan variance shows that a minimum detectable concentration 60 ppbv is obtained with a lock-in time constant of 10 ms, and a detection limit of 13 ppbv can be achieved by average in 300 s. The demonstrated H2S sensor has a strong penitential application in natural gas process for regulating and controlling H2S concentration. [ABSTRACT FROM AUTHOR]