ABSTRACT
In most cases, a molecular ion is observed in femtosecond laser ionization mass spectrometry, which provides information concerning the molecular weight of the analyte. However, the Ti:sapphire laser currently used as the ionization source is costly and involves special skills for operation and maintenance, which prevents its practical use in many applications. In this study, we report on the development of a miniature time-of-flight mass analyzer with a flight tube length of 65 mm for use in combination with a compact highly-repetitive (120-560 kHz) femtosecond Yb laser and a time-correlated single ion counting system. The fundamental beam (1030 nm) was converted into ultraviolet beams emitting at 343, 257, and 206 nm, which was utilized as an efficient two-photon ionization source. A mass resolution of 670 was achieved for the molecular ion of chlorobenzene, the minimum time for measuring a mass spectrum being 0.1 s. This mass spectrometer was used in the on-site real-time monitoring of products appeared by the combustion of plastic, some nerve agent analogs, and an explosive in the air. The interference arising from nitrogen and oxygen in the air was suppressed, since they require nonresonant four- and three-photon ionizations, respectively. The mass spectrometer was combined with a gas chromatograph and used for the comprehensive analysis of polycyclic aromatic hydrocarbons, suggesting its potential advantage for use in the practical trace analysis of organic compounds in the environmental and forensic sciences.
Subject(s)
Lasers , Polycyclic Aromatic Hydrocarbons , Gas Chromatography-Mass Spectrometry/methods , Mass Spectrometry/methods , Photons , Polycyclic Aromatic Hydrocarbons/analysisABSTRACT
BACKGROUND: In many countries, in-hospital survival from tetanus is increasing, but long-term outcome is unknown. In high-income settings, critical illness is associated with muscle wasting and poor functional outcome, but there are few data from resource-limited settings. In this study we aimed to assess muscle wasting and long-term functional outcome in adults with tetanus. METHODS: In a prospective observational study involving 80 adults with tetanus, sequential rectus femoris ultrasound measurements were made at admission, 7 days, 14 days and hospital discharge. Functional outcome was assessed at hospital discharge using the Timed Up and Go test, Clinical Frailty Score, Barthel Index and RAND 36-item Short Form Health Survey (SF-36) and 3 and 6 months after discharge using the SF-36 and Barthel Index. RESULTS: Significant muscle wasting occurred between hospital admission and discharge (p<0.01), particularly in severe disease, where a median 23.49% (interquartile range 10.01-26.07) reduction in rectus femoris cross-sectional area occurred in those with severe (Ablett grades 3 and 4) disease. Muscle mass at discharge was related to objective and subjective measures of physical and emotional function at discharge and 3 and 6 months after discharge. In patients >70 y of age, functional recovery at 6 months was reduced compared with younger patients. Hospital-acquired infection and age were risk factors for muscle wasting. CONCLUSIONS: Significant muscle wasting during hospitalization occurred in patients with tetanus, the extent of which correlates with functional outcome.
Subject(s)
Muscle Weakness/etiology , Muscle Weakness/physiopathology , Tetanus/complications , Tetanus/physiopathology , Adult , Critical Illness , Follow-Up Studies , Hospitalization/statistics & numerical data , Humans , Male , Middle Aged , Prospective Studies , Time FactorsABSTRACT
BACKGROUND: The cost of treatment for infectious shock in intensive care in Vietnam is unknown. METHODS: We prospectively investigated hospital bills for adults treated for septic and dengue shock in Vietnam and calculated the proportion who faced catastrophic health care expenditures. RESULTS: The median hospital bills were US$617 for septic shock (n=100) and US$57 for dengue shock (n=88). Catastrophic payments were incurred by 47% (47/100) and 13% (11/88) of patients with septic shock and dengue shock, respectively, and 56% (25/45) and 84% (5/6) fatal cases of septic shock and dengue shock respectively. CONCLUSIONS: Further advocacy is required to moderate insurance co-payments for costly critical care interventions.
