Time-saving effects using helicopter transportation: comparison to a ground transportation time predicted using a social navigation software.

ABSTRACT: Previous comparison studies regarding 2 types of transportation, helicopter (HEMS) versus ground emergency medical services (GEMS), have shown underlying heterogeneity as these options have completely different routes and consequent times with reference to one patient. To compare the 2 types of transportation on a case-by-case basis, we analyzed the retrospectively reviewed HEMS and predicted GEMS data using an open-source navigation software.Patients transferred by military HEMS from 2016 to 2019 were retrospectively enrolled. The HEMS records on the time of notification, injury point and destination address, and time required were reviewed. The GEMS data on distance and the predicted time required were acquired using open-source social navigation systems. Comparison analyses between the two types of transportation were conducted. Furthermore, linear logistic regression analyses were performed on the distance and time of the two options.A total of 183 patients were enrolled. There was no statistical difference (P = .3021) in the distance between the 2 types of transportation, and the HEMS time was significantly shorter than that of GEMS (61.31 vs 116.92 minutes, P < .001). The simple linear curves for HEMS and GEMS were separately secured, and two graphs presented the statistical significance (P) as well as reasonable goodness-of-fit (R2). In general, the HEMS graph demonstrates a more gradual slope and narrow distribution compared to that of GEMS.Ideally, HEMS is identified as a better transportation modality because it has a shorter transportation time (56 minutes saved) and a low possibility of potential time delays (larger R2). With a strict patient selection, HEMS can rescue injured or emergent patients who are "out of the golden hour."

Effect of complexing agent and annealing atmosphere on properties of nanocrystalline ZnS thin films.

The nanocrystalline Zinc Sulfide (ZnS) thin films were prepared on glass substrates by chemical bath deposition (CBD) method using aqueous solutions of zinc acetate, thiourea and tri-sodium citrate in alkaline medium at 80 degrees C. The tri-sodium citrate acts as a complexing agent. The effects of complexing agent and annealing atmosphere (95%N2 + 5%H2S) on structural, morphological and optical properties of ZnS thin films were studied using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and optical absorption. XRD study revealed that single phase ZnS powder was formed in the solution with tri-sodium citrate, however, ZnS and ZnO mixed phase powder was formed in the solution without tri-sodium citrate. The films deposited with trisodium citrate showed ZnS with hexagonal wurtzite phase. However, annealed film in (N2 + H2S) atmosphere showed cubic (zincblende) phase. FE-SEM images show that grain size of as-deposited and annealed ZnS films are about 20 nm and 50 nm, respectively. Optical absorption study showed that the films have moderate optical transmission from 65% to 75% in the visible region and the optical band gap energy of as-deposited ZnS film is 3.91 eV and it decreases to 3.73 eV after annealing.

Controlling the surface morphology of ZnO films grown on glass substrates by hydrothermal method at 90 degrees C: effects of Na-citrate on the shape of ZnO nano-crystallites.

The effects of Na-citrate on the morphology change of ZnO films, grown on ZnO buffered glass substrates by hydrothermal synthesis at 90 degrees C and at pH 10.9, have been investigated. Dense and smooth ZnO film consists of ZnO nano-rods that have flat ends was grown with Na citrate. However, very rough ZnO film consists of ZnO nano-rods that have sharp ends were grown without Na citrate. X-ray diffraction analysis shows that all the ZnO films were grown with strong c-axis out-of-plane orientation. Optical transmission spectroscopy of the ZnO films grown with and without Na-citrate shows band gap energy values of 3.36 eV and 3.28 eV, respectively. Photoluminescence results showed strong defect related emission peak centered near 545 nm in the ZnO film grown without Na citrate and strong band-edge emission peak centered near 378 nm in the ZnO film grown with Na citrate.

Electronic structure of P-doped ZnO films with p-type conductivity.

The electronic structure of laser-deposited P-doped ZnO films was investigated by X-ray absorption near-edge structure spectroscopy (XANES) at the O K-, Zn K-, and Zn L3-edges. While the O K-edge XANES spectrum of the n-type P-doped ZnO demonstrates that the density of unoccupied states, primarily O 2p-P 3sp hybridized states, is significantly high, the O K-edge XANES spectrum of the p-type P-doped ZnO shows a sharp decrease in intensity of the corresponding feature indicating that P replaces O sites in the ZnO lattice, and thereby generating P(O). This produces holes to maintain charge neutrality that are responsible for the p-type behavior of P-doped ZnO. Both the Zn K-, and Zn L3-edge XANES spectra of the P-doped ZnO reveal that Zn plays no significant role in the p-type behavior of ZnO:P.