Cardiac Function in Brain Death, Usage of Advanced Hemodynamic Monitoring

Background: This study used advanced hemodynamic monitoring along with simultaneous echocardiography to assess donated heart function of brain death patients using advanced hemodynamic monitoring and its efficacy in organ donation. Methods: Forty-eight brain death patients who were candidates of heart donation on the basis of primary standard investigations were selected with purposive and convenient sampling methods. They were investigated with advanced hemodynamic monitoring after echocardiography and primary assessments and the gleaned data were recorded. Results: Echocardiography showed that LVS (left ventricle size) and LVF (left ventricle function) were normal in %100 and %87.5 of patients, respectively. LVEF (left ventricle ejection fraction) was <%50 in %12.5 and >%50 in %87.5 of patients. SVR was smaller than 1200 at the beginning of the study that reached %54.4 at the end of the study. CI (cardiac index) was < 2.4 in %16.7 of the patients at the onset of the study that reached %25 at the end. Reduction of CI and SVR in patients with EF <%50 was significantly higher than that in patients with EF>%50. Conclusion: Given the extensive pathological changes in the cardiovascular system exerted by brain death, advanced hemodynamic monitoring, if performed continually, can greatly aid in managing inotropic drugs in these patients, decision-making for managing intravascular volume, creating hemodynamic stability, and finally, preventing deterioration of function of the donated heart and loss of a donated organ.

Optical power scale realization using the predictable quantum efficient detector

We report realization of scales for optical power of lasers and spectral responsivity of laser power detectors based on a predictable quantum efficient detector (PQED) over the spectral range of 400 nm–800 nm. The PQED is characterized and used to measure optical power of a laser that is further used in calibration of the responsivities of a working standard trap detector at four distinct laser lines, with an expanded uncertainty of about 0.05%. We present a comparison of responsivities calibrated against the PQED at Aalto and the cryogenic radiometer at RISE, Sweden. The measurement results support the concept that the PQED can be used as a primary standard of optical power.

ANALYSIS OF THE ERROR COMPONENTS OF LEVER TYPE FORCE-GENERATING MACHINES

The national standards are the basis of the technical base of the state metrological system. The developing of a na-tional primary standard of force unit solves such tasks as ensuring the uniformity of force measurements, transmitting the size of a unit of force with the required accuracy, metrological support of a large fleet of working standards and measuring instruments used in Ukraine. One of the main stages in the creation of the national standard is the development of a mathematical model of the process of reproducing the unit size of a physical quantity, namely N - Newton. The purpose of this study is to analyze the components of the error of force-generating installations of the multi-lever type, which are part of the national standard. Force generating installations used by calibration laboratories are usually traced to national standards through verification using precision force transducers. Calibration of force measuring instruments will typically be performed on these installations according to a documented procedure, such as ISO 376, and the components of error and uncertainty of calibration results will depend on the calibration and measurement capabilities of the unit size reproduction. Similarly, the uncertainty of the calibration of industrial force measuring in-struments will depend in part on the uncertainty contributing by the force measuring instrument, and the uncertainty of any subsequent force measurement will depend in part on the uncertainty associated with the reproduction of a unit of force, including national standard. It can be seen that the uncertainty of the final strength measurement depends on all previous stages of the measurement, and this work aims to make recommendations on how these contributions can be estimated. The purpose of this study is to analyze the components of the error of power plants of the multi-lever type, which are part of the state standard. The paper analyzes the method of reproduction, storage and transmission of the unit size, lever reinforcement installations, which can be used as reference metrological institutes and calibration laboratories. The basic principles of operation of the above reference installations are considered and the mathematical model of reproduction of the size of unit of force is created.

Heavy Metals in Marine Surface Sediments of Daya Bay, Southern China: Spatial Distribution, Sources Apportionment, and Ecological Risk Assessment

Daya Bay, especially in the northwestern region, which is a nature reserve with larval economic fish and shrimp populations, is no longer an unpolluted marine environment due to the recent increases in anthropogenic activities. This study collected seasonal surface sediment samples from 20 sites in northwestern Daya Bay to evaluate pollution and ecological risks and to identify possible sources and transport pathways of heavy metals (Cd, Pb, Cr, Cu, Zn, Hg, As). The results showed that all the heavy metal concentrations were below the established primary standard criteria, except for concentrations of Cr in spring, as well as Cu and Zn in autumn at several sampling stations, which had excess rates of 35, 4.76, and 4.76%, respectively. The geoaccumulation index (Igeo) values of heavy metals indicated that all sites had unpolluted to moderate pollution levels. In comparison to the samples collected in autumn, those in spring experienced a higher degree of pollution, particularly Cr and As. The ecological risk indices of heavy metals in sediments ranged from 225.86 to 734.20 in spring and from 196.69 to 567.52 in autumn, suggesting that most sites had a moderate ecological risk or a considerable ecological risk, and very few a had high ecological risk. Moreover, ArcGIS10.2 software was used to visualize their spatial distribution, and the results were similar in both spring and autumn. The results of the Pearson correlation analysis and principal component analysis showed that Cu, Hg, and Pb might be affected by anthropogenic activities, and As might be derived from natural sources such as atmospheric inputs. A cluster analysis showed that heavy metals were mainly affected by the negative impacts of human beings on the environment.

Assessment of real-time bioaerosol particle counters using reference chamber experiments

This study presents the first reference calibrations of three commercially available bioaerosol detectors. The Droplet Measurement Technologies WIBS-NEO (new version of the wideband integrated bioaerosol spectrometer), Plair Rapid-E, and Swisens Poleno were compared with a primary standard for particle number concentrations at the Federal Institute for Metrology (METAS). Polystyrene (PSL) spheres were used to assess absolute particle counts for diameters from 0.5 to 10 µm. For the three devices, counting efficiency was found to be strongly dependent on particle size. The results confirm the expected detection range for which the instruments were designed. While the WIBS-NEO achieves its highest efficiency with smaller particles, e.g. 90 % for 0.9 µm diameter, the Plair Rapid-E performs best for larger particles, with an efficiency of 58 % for particles with a diameter of 10 µm. The Swisens Poleno is also designed for larger particles but operates well from 2 µm. However, the exact counting efficiency of the Poleno could not be evaluated as the cut-off diameter range of the integrated concentrator unit was not completely covered. In further experiments, three different types of fluorescent particles were tested to investigate the fluorescent detection capabilities of the Plair Rapid-E and the Swisens Poleno. Both instruments showed good agreement with the reference data. While the challenge to produce known concentrations of larger particles above 10 µm or even fresh pollen particles remains, the approach presented in this paper provides a potential standardised validation method that can be used to assess counting efficiency and fluorescence measurements of automatic bioaerosol monitoring devices.

The NMIJ air kerma primary standard for high energy X-ray beams in 300-450 kV

Accurate radiation dosimetry is required for radiation protection in various environments. Therefore, dosemeters and dose-rate meters must be calibrated in standard radiation fields. The National Metrology Institute of Japan (NMIJ) expands the energy range of X-ray reference field measurement up to 450 kV using a cylindrical graphite-walled cavity ionization chamber. Departure from the condition of the Spencer-Attix cavity theory was evaluated by comparing the measurement results obtained using the cavity ionization and the free-air ionization chambers, which are used as the primary standard up to a tube voltage of 250 kV. The calibration coefficients found using the spherical ionization chamber were in good agreement with those obtained by the free-air ionization chamber within relative standard uncertainties (k = 1) for N-200 and N-250 X-ray fields. Consistent calibration coefficients were obtained in the energy range 300–450 kV.