Comparison of hyperpolarised gas MRI and CT-based surrogates of ventilation

Background: Non-contrast CT-based surrogates of regional ventilation derived from pulmonary images acquired at multiple inflation levels have been proposed as alternatives to established modalities. However, their physiological accuracy has yet to be validated prior to clinical translation. Purpose: To address the hypothesis that these surrogates can provide information comparable to a direct measure of ventilation from hyperpolarised gas MRI ventilation via: i. development of a methodology for registering CT and gas MRI. ii. comparison of these surrogates with gas MRI at the lobar level. iii. evaluation of the impact of inflation levels when comparing gas MRI and ventilation CT. iv. development of an image acquisition and analysis framework to facilitate spatial correlations of both techniques. v. assessment of the effect of using different gases on the correlation. Methods: i. A method to indirectly register gas MRI to CT via same-breath 1H-structural MR images was developed and its accuracy was assessed. ii. A ventilation model based on expansion of lobar CT segmentations was compared with gas MRI lobar ventilation measurements. iii. The spatial overlap of ventilation CT was compared to gas MRI acquired at two different inflation levels. iv. An image acquisition protocol was designed to minimise differences in acquisition settings between scans such as posture and breathing manoeuvre and analysis methods were developed to enable direct regional and voxel level correlations. v. The effect of using two different noble gases, namely, 3He and 129Xe, on correlation with ventilation CT was assessed. Results: i. The indirect method of registration was more accurate than direct registration. ii. Despite subtle differences, lobar ventilation measurements derived from CT and hyperpolarised gas MRI were comparable. iii. Comparison of ventilation CT and gas MRI varied with inflation state. iv. The spatial correlation between ventilation CT and gas MRI increased at coarser levels. v. A marked improvement in correlation was observed for 3He and 129Xe MRI in contrast to when ventilation CT was compared with either 3He and 129Xe MRI. Conclusion: Although CT-based surrogates of ventilation show promise for replacing established ventilation modalities such as hyperpolarised gas MRI, particularly at coarser levels, they cannot be assumed to be equivalent to the techniques they purport to replace

Curricula for Teaching MRI Safety and MRI/CT Contrast Safety To Residents: How Effective Are Live Lectures and Online Modules?

Purpose The advent of the diagnostic radiology core examination and the new ACGME “milestone” evaluation system for radiology residents places new emphasis on topics in MRI and CT safety, and MRI and CT contrast agents. We evaluated whether either lecture-based teaching or online modules would improve baseline resident knowledge in these areas, and assessed which intervention was more effective. Methods Before didactic intervention, 2 cohorts were created from 57 radiology residents, with equal numbers and a matched level of training. The residents were tested on their baseline knowledge of MRI, MRI contrast safety, and CT contrast safety, using a multiple-choice examination. One group attended a live, 1-hour lecture on the preceding topics. The other engaged in 3 short online educational modules. After 6 weeks, the residents were again tested with the same questions to assess for improvement in their understanding. Results Both the module and lecture cohorts demonstrated a statistically significant increase in questions answered correctly on CT contrast safety (13.1%, P < .001, and 19.1%, P < .001, respectively), and on MRI and MRI contrast safety (12.9%, P < .001, and 14.4%, P < .001). The preintervention and postintervention scores, and degree of improvement postintervention, were similar for the module versus lecture groups, without a statistically significant difference (P = .70). Resident confidence improved in both groups, for both modalities. Conclusions Focused didactic intervention improves resident knowledge of MRI and CT safety, and MRI and CT contrast agents. Live lectures and online modules can be equally effective, allowing residency programs flexibility

Electron emission characterization of laser-induced gaseous plasma

Laser induced hydrogen plasma has been investigated as a source of electrons. The energy, temperature and flux of the electrons have been determined by using two different temporal detectors; Faraday cup and Rogowski coil. The energy, temperature and flux were measured from the electrons extracted from laser induced hydrogen plasma. The Rogowski coil has been used for measurement of flux and current whereas Faraday cup has been used to determine the current density in laser induced plasma. The energy and temperature of the electrons are measured by the time of flight method in the range of 1.23 - 5.04 keV and 2516.26 eV, respectively. The flux of the electrons has been measured ≈ 1015 by Rogowski coil and the maximum current has been measured to be 39.6 kA. The current density has been measured by the Faraday cup ranges from 20 Am-2 to 23 Am-2

A Diverse Domain Generative Adversarial Network for Style Transfer on Face Photographs

The applications of style transfer on real time photographs are very trending now. This is used in various applications especially in social networking sites such as SnapChat and beauty cameras. A number of style transfer algorithms have been proposed but they are computationally expensive and generate artifacts in output image. Besides, most of research work only focuses on some traditional painting style transfer on real photographs. However, our work is unique as it considers diverse style domains to be transferred on real photographs by using one model. In this paper, we propose a Diverse Domain Generative Adversarial Network (DD-GAN) which performs fast diverse domain style translation on human face images. Our work is highly efficient and focused on applying different attractive and unique painting styles to human photographs while keeping the content preserved after translation. Moreover, we adopt a new loss function in our model and use PReLU activation function which improves and fastens the training procedure and helps in achieving high accuracy rates. Our loss function helps the proposed model in achieving better reconstructed images. The proposed model also occupies less memory space during training. We use various evaluation parameters to inspect the accuracy of our model. The experimental results demonstrate the effectiveness of our method as compared to state-of-the-art results

PHYTOCHEMICAL SCREENING OF DIFFERENT ROOT EXTRACTS OF Ageratum conyzoides AND THEIR POTENTIAL BIOACTIVE PROPERTIES

The present study was conducted to determine different classes of secondary metabolites of Ageratum conyzoides root extracts and to evaluate their antioxidant, antibacterial, and antifungal potentialities using various pathogenic fungal and different gram-positive/gram-negative bacterial strains. The roots powder was subjected to ultrasonic-assisted extraction with n-hexane, acetone, ethanol, and EtOH:H2O(1:1). The screening of phytochemicals indicated the existence of terpenoids, alkaloids, coumarins, sterols, flavonoids, and glycosides in the root extract of A. conyzoides. However, the absence of saponins, tannins, anthocyanidins, anthraquinones, and phlobatannins was observed. The results indicated a reasonable antibacterial (against gram-negative and gram-positive bacteria), and antifungal potential. The antibacterial activity of the ethanolic extract was highest against all four strains of bacteria and was also comparable to the standard medicines used. However, antifungal activity was highest in EtOH:H2O (1:1) extract. Moderate antioxidant properties were also demonstrated, favoring the importance of the roots of this plant from a medicinal point of view

Efficient photocatalysis through conductive polymer coated FTO counter electrode in platinum free dye sensitized solar cells

This is the final version. Available on open access from Elsevier via the DOI in this recordPlatinum-free counter electrodes are crucial for developing cost effective solar energy harvesting technology. We describe here the fabrication of efficient platinum free FTO counter electrodes for dye sensitized solar cells based on pristine polyaniline, polyaniline doped with sulfuric acid, ammonuim lauryl sulfate, as well as binary doped with sulfuric acid and ammonium lauryl sulphate. The characteristics of these counter electrodes were analyzed using cyclic voltammetry, photocurrent density–voltage and electrochemical impedance spectroscopy measurements. At optimized fabrication conditions, the counter electrode shows significantly high photoelectric conversion efficiency of 4.54% compared to 4.03% for reference platinum counter electrode. Charge transfer resistance at the interface between electrolyte and counter-electrode is also decreased for the optimized polyaniline based counter electrode. Furthermore, the device presented characteristics of multiple start/stop ability and fast activity. The simple preparation procedure, low cost and improved photoelectric properties permit fabricated counter electrode to be a reliable alternative for dye sensitized solar cells.Engineering and Physical Sciences Research Council (EPSRC)Alexander von Humboldt Foundation, GermanyHigher Education Commission Pakista