ResultsMore than 60% of the patients stated that their current device is the easiest to use. The means of the measured PIFdev values were 91.4 L/min, 77.1 L/min and 77.5 L/min for Breezhaler ® , Genuair ® , and Turbuhaler ® , respectively. PIFdev were significantly higher for males than for females, but differences upon age, BMI and disease severity group were not significant (at p=0.05). Peak inspiratory flows through the inhalers (PIFdev) correlated best with their native spirometric counterparts (PIF) and linear PIFdev-PIF relationships could be determined (Breezhaler ® : r=0.60, p=0.002, Genuair ® : r=0.55, p=0.001, Turbuhaler ® : r=0.57, p=0.002). Physical background of the deduced equations was also provided.
ConclusionsPresent correlations may be used to assess the success of inhalation of COPD patients through the studied devices and to choose the appropriate device for each patient. As a consequence, the amount of the drug emitted by the device can be optimized, the deposition efficiency within the lungs increased and the related therapeutic effect improved.
Lack of coordination between the beginning of the inhalation and device triggering is one of the most frequent errors reported in connection with the use of pMDI devices. Earlier results suggested a significant loss in lung deposition as a consequence of late actuation. However, most of our knowledge on the effect of poor synchronization is based on earlier works on CFC devices emitting large particles with high initial velocities. The aim of this study was to apply numerical techniques to analyse the effect of late device actuation on the lung dose of a HFA pMDI drug emitting high fraction of extrafine particles used in current asthma and COPD therapy. A computational fluid and particle dynamics model was combined with stochastic whole lung model to quantify the amount of drug depositing in the extrathoracic airways and in the lungs. High speed camera measurements were also performed to characterize the emitted spray plume. Our results have shown that for the studied pMDI drug late actuation leads to reasonable loss in terms of lung dose, unless it happens in the second half of the inhalation period. Device actuation at the middle of the inhalation caused less than 25% lung dose reduction relative to the value characterizing perfect coordination, if the inhalation time was between 2 and 5 s and inhalation flow rate between 30 and 150 L/min. This dose loss is lower than the previously known values of CFC devices and further support the practice of triggering the device shortly after the beginning of the inhalation instead of forcing a perfect synchronization and risking mishandling and poor drug deposition.
Plasma immersion ion implantation and focused ion beam treatment techniques were used to create nitrogen-related complex defect centers in detonation nanodiamond crystals. Helium implantation was used to produce vacancies in the crystal structure, which was followed by the introduction of nitrogen ions (with the same method). Heat treatment at 1,023 K was applied to initiate vacancy diffusion and formation of complex defect centers. The sp 2 carbon content of the samples formed during the implantation and the high-temperature annealing was decreased by oxidation at 723 K in air. Changes in the bonding structure were monitored by Raman and infrared spectroscopic measurements after each step of the defect creation process. It was found that the photoluminescence of nanosized diamond changes remarkably as a consequence of different treatments and a new, narrow, intense emission band develops in the deep blue wavelength region. The N3 nitrogen-related complex defect center was considered as source of this fine structured emission band in the luminescence spectrum.
Background
In many of the risk estimation algorithms for patients with ST-elevation myocardial infarction (STEMI), heart rate and systolic blood pressure are key predictors. Yet, these parameters may also be altered by the applied medical treatment / circulatory support without concomitant improvement in microcirculation. Therefore, we aimed to investigate whether venous lactate level, a well-known marker of microcirculatory failure, may have an added prognostic value on top of the conventional variables of the “Global Registry of Acute Coronary Events” (GRACE) 2.0 model for predicting 30-day all-cause mortality of STEMI patients treated with primary percutaneous coronary intervention (PCI).
Methods
In a prospective single-center registry study conducted from May 2020 through April 2021, we analyzed data of 323 cases. Venous blood gas analysis was performed in all patients at admission. Nested logistic regression models were built using the GRACE 2.0 score alone (base model) and with the addition of venous lactate level (expanded model) with 30-day all-cause mortality as primary outcome measure. Difference in model performance was analyzed by the likelihood ratio (LR) test and the integrated discrimination improvement (IDI). Independence of the predictors was evaluated by the variance inflation factor (VIF). Discrimination and calibration was characterized by the c-statistic and calibration intercept / slope, respectively.
Results
Addition of lactate level to the GRACE 2.0 score improved the predictions of 30-day mortality significantly as assessed by both LR test (LR Chi-square = 8.7967, p = 0.0030) and IDI (IDI = 0.0685, p = 0.0402), suggesting that the expanded model may have better predictive ability than the GRACE 2.0 score. Furthermore, the VIF was 1.1203, indicating that the measured lactate values were independent of the calculated GRACE 2.0 scores.
Conclusions
Our results suggest that admission venous lactate level and the GRACE 2.0 score may be independent and additive predictors of 30-day all-cause mortality of STEMI patients treated with primary PCI.
Aerosol particles proved to play a key role in airborne transmission of SARS-CoV-2 viruses. Therefore, their size-fractionated collection and analysis is invaluable. However, aerosol sampling in COVID departments is not straightforward, especially in the sub-500-nm size range. In this study, particle number concentrations were measured with high temporal resolution using an optical particle counter, and several 8 h daytime sample sets were collected simultaneously on gelatin filters with cascade impactors in two different hospital wards during both alpha and delta variants of concern periods. Due to the large number (152) of size-fractionated samples, SARS-CoV-2 RNA copies could be statistically analyzed over a wide range of aerosol particle diameters (70–10 µm). Our results revealed that SARS-CoV-2 RNA is most likely to exist in particles with 0.5–4 µm aerodynamic diameter, but also in ultrafine particles. Correlation analysis of particulate matter (PM) and RNA copies highlighted the importance of indoor medical activity. It was found that the daily maximum increment of PM mass concentration correlated the most with the number concentration of SARS-CoV-2 RNA in the corresponding size fractions. Our results suggest that particle resuspension from surrounding surfaces is an important source of SARS-CoV-2 RNA present in the air of hospital rooms.
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