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Cardiac biomarkers in acute coronary syndrome
Published in K Sarat Chandra, AJ Swamy, Acute Coronary Syndromes, 2020
Brennan et al. enrolled 604 patients admitted to the ED with chest pain. They investigated the correlation between risk of major cardiac events at 30 days and 6 months and increase in MPO concentration. The result was a progressive increase in odds ratios for major cardiac events with each quartile of MPO concentration. In the CAPTURE trial, MPO mass concentration was measured in 1090 patients with diagnosis of ACS and the death and MI were determined at 6 months of follow-up. The result was that MPO and the other markers studied (cTnT, soluble cd40L, CRP and vascular endothelial growth factor) were independent predictors of adverse cardiac events. Using a cut-off of 350 μg/L for MPO in patients with ACS, the adjusted hazard ratio was 2.25 (95% CI 1.32–3.82) and considering only patients with undetectable cardiac troponin the hazard ratio was 7.48 (95% CI 1.98–28.29). In summary, observations from studies that have investigated MPO activity, demonstrated MPO is more than a marker of oxidative stress and not only a marker of plaque instability [34,35].
Lung Cancer Risk of a Population Exposed to Airborne Particles: The Contribution of Different Activities and Microenvironments
Published in Ayman El-Baz, Jasjit S. Suri, Lung Imaging and CADx, 2019
The evaluation of the chemical composition of PM10 emitted by wood and pellet combustion phenomena was performed by collecting PM10 samples and performing a post hoc chemical analysis. To this end, the following equipment was used: A gravimetric sampler made up of a volumetric rotating pump (Zambelli 6000 Plus, equipped with temperature and atmospheric pressure sensors to measure normalized sampling volume) and a Zambelli PM10 impactor (working at a nominal fixed flow rate of 2.3 m3 h−1 according to EN 12341 [90]) to collect particulate matter on a quartz filter for post hoc chemical analysis and PM10 mass concentration evaluationAn Ultra Trace gas chromatograph coupled with a TSQ mass spectrometer (Thermo Fischer Scientific) to perform gas chromatography–mass spectrometry (GC/MS) analyses on PM samplesA Triga Mark II nuclear reactor (ENEA-Casaccia Laboratories) for the PM sample irradiation
Nanocarrier Technologies for Enhancing the Solubility and Dissolution Rate of Api
Published in Debarshi Kar Mahapatra, Sanjay Kumar Bharti, Medicinal Chemistry with Pharmaceutical Product Development, 2019
Ashwini Deshpande, Tulshidas S. Patil
Concentration: It is usually expressed in the form of mass concentration. It strongly weighs the distribution curve in favor of larger particles – a single 10 µm diameter particle weighs the same as 1 million 100 nm particles! Also MALDI-MS technique can be used for concentration determination.
Assessing variability of aerosols generated from e-Cigarettes
Published in Inhalation Toxicology, 2022
Darpan Das, Sarah-Marie Alam El Din, Jairus Pulczinski, Jana N. Mihalic, Rui Chen, Joseph Bressler, Ana M. Rule, Gurumurthy Ramachandran
Comparison between time-resolved and gravimetric mass concentration was done to calculate a correction factor, needed for optical PM instruments. Gravimetric PM10 (average±Stdev) mass concentration was 34.3 + 59.5 mg/m3 for PG:VG, 16.2 ± 18.4 mg/m3 for PG:VG + EM, 28.1 ± 39.3 mg/m3 for PG:VG + Nic and 7.4 ± 6.1 mg/m3 for PG:VG + EM + Nic. The filter-based mass loading of PM10 aerosol only contributes 1-5% of the calculated concentration derived from difference in pod weight measurements, indicative of several factors such as evaporation losses, and losses to the sampling setup. On top of this, the viscous nature of the aerosol (droplets may appear larger to the optical sensor) and optical properties of the aerosol that differ significantly from those of the Arizona Road Dust used to calibrate the instruments may cause additional differences. No relative humidity correction was performed since the RH measured inside the chambers was found to be ∼15%.
Quality assurance for nanomaterial inhalation toxicity testing
Published in Inhalation Toxicology, 2021
Sung Kwon Lee, Mi Seong Jo, Hoi Pin Kim, Jong Choon Kim, Il Je Yu
Available aerosol monitoring devices are summarized in Table 3 (modified from Yu et al. 2021). Here, QA should ensure the appropriateness of the particle characterization and check that the relevant SOPs (standard operation procedures) have been prepared. The essential SOPs include: 1) mass concentration measurement by filter sampling, 2) real-time particle number concentration measurement using an OPC or SMPS, 3) MMAD measurement using an impactor, where the MMAD should be less than 2 μm with a GSD 1–3, if not, an appropriate reason must be stated, 4) optical methods of particle characterization, such as TEM and SEM, and 5) purity determination of test nanomaterials, such as ICP-MS (inductively coupled plasma-mass spectrometry), TEM-EDX (energy dispersive X-ray analyzer), SEM-EDX, or GC-MS (gas chromatography-mass spectrometry). The characterization methods for nanomaterials are listed in the Annex of ISO 13014. When estimating mass concentration using DMAS, QA and study director should notice that the overall aerosol size distribution may include particles that are both larger than and smaller than what can be captured by the instrument. The fraction of the particles in the overall distribution that lie outside of the DMAS measurement range particularly the larger ones may contribute substantially to the mass concentration, thus producing measurement errors. On-site calibration of particle counters such as OPC and SMPS is not possible. All equipment calibration should follow the manufacturer’s instructions. Plus, appropriate calibration of the sampling pump should also be checked.
Process parameters of microsphere preparation based on propylene carbonate emulsion-precursors
Published in Journal of Microencapsulation, 2021
The solubility of different grades of PLGA (RG 502H, RG 503H, RG 504H and RG 505) in PC was evaluated as follows: PLGA was added gradually to 1 mL of propylene carbonate under magnetic stirring until a clear solution or a high viscosity (>1000 mPas) was obtained. The solubility was determined by differential weighing and expressed as mass concentration [mg/mL]. All viscosity measurements were performed on a rotational viscometer (Roto Visco 1, Haake, Thermo Scientific, Germany) equipped with a 60 mm diameter plate-cone setup at 20 ± 0.2 °C. A constant stepwise increase in shear rate (18 s−1 step every 30 s) was used until a shear rate of 125 s−1 was achieved. At this constant shear rate all results were obtained. The viscosity of deionised and degassed water was used before each polymer type measurement to ensure the validity of the results.