Diode-laser Based Photo-acoustic Spectroscopy In Atmospheric No­2 Detection

We have developed a simple, low cost, and compact NO2 detection system. It\u27s based on photoacoustic spectroscopy (PAS) method uses a diode laser as a source of radiation. The PAS system has a detection limit of 10 ppbv for NO2. With this set-up we were able to detect the NO2 concentration from urban air near our campus. We have also investigated the NO2 dissociation effect on the PAS system via NO measurements using a direct absorption spectroscopy method on quantum cascade laser (QCL) system. Keywords: photoacoustic spectroscop

The influence of biological maturity on dynamic force-time variables and vaulting performance in young female gymnasts

Jumping and rebounding are important prerequisites that underpin the high impact loading gymnastics skills (e.g. acrobatic series, tumbling etc.) (Suchomel et al. 2016). Further, three of the four artistic disciplines that female gymnasts compete in (vault, beam and floor exercise) are heavily reliant on explosive lower-limb rebounding and jumping activities, which all utilize various expressions of the stretch-shortening cycle (SSC) (Moeskops et al. 2019). Consequently, rebounding and jumping performance of artistic gymnasts are commonly assessed to identify key determinants of the sport (Dallas G et al. 2013; Marina et al. 2013; Marina M. and F.A. 2013; Suchomel et al. 2016), determine physical profiles (Pion et al. 2015; Vandorpe et al. 2012) and evaluate the efficacy of training interventions (Colclough et al. 2018; Hall et al. 2016; Marina and Jemni 2014; Moeskops et al. 2018b)

Laser spectroscopy for breath analysis : towards clinical implementation

Detection and analysis of volatile compounds in exhaled breath represents an attractive tool for monitoring the metabolic status of a patient and disease diagnosis, since it is non-invasive and fast. Numerous studies have already demonstrated the benefit of breath analysis in clinical settings/applications and encouraged multidisciplinary research to reveal new insights regarding the origins, pathways, and pathophysiological roles of breath components. Many breath analysis methods are currently available to help explore these directions, ranging from mass spectrometry to laser-based spectroscopy and sensor arrays. This review presents an update of the current status of optical methods, using near and mid-infrared sources, for clinical breath gas analysis over the last decade and describes recent technological developments and their applications. The review includes: tunable diode laser absorption spectroscopy, cavity ring-down spectroscopy, integrated cavity output spectroscopy, cavity-enhanced absorption spectroscopy, photoacoustic spectroscopy, quartz-enhanced photoacoustic spectroscopy, and optical frequency comb spectroscopy. A SWOT analysis (strengths, weaknesses, opportunities, and threats) is presented that describes the laser-based techniques within the clinical framework of breath research and their appealing features for clinical use.Peer reviewe

Sub-part-per-billion monitoring of nitric oxide by use of wavelength modulation spectroscopy in combination with a thermoelectrically cooled, continuous-wave quantum cascade laser

Contains fulltext : 35376.pdf (publisher's version ) (Open Access)We used a thermoelectrically cooled, continuous-wave, quantum cascade laser operating between 1847 and 1854 cm(-1) in combination with wavelength modulation spectroscopy for the detection of nitric oxide (NO) at the sub-part-per-billion by volume (ppbv) level. The laser emission overlaps the P-7.5 doublet of NO centered around 1850.18 cm(-1). Using an astigmatic multiple-pass absorption cell with an optical path length of 76 m, we achieved a detection limit of 0.2 ppbv at 1.0 kPa, with a total acquisition time of 30 s. The corresponding minimal detectable absorption is 8.8 X 10(-9) cm(-1) Hz(-1/2). (c) 2006 Optical Society of America

Delayed cortical gray matter development in neonates with severe congenital heart disease

\u3cp\u3eBACKGROUND: This study aimed to assess cortical gray matter growth and maturation in neonates with congenital heart disease (CHD).\u3c/p\u3e\u3cp\u3eMETHODS: 31 (near) term neonates with severe CHD (8 univentricular heart malformation (UVH), 21 d-transposition of great arteries (d-TGA) and 2 aortic coarctation) underwent cerebral MRI before (postnatal-day 7) and after (postnatal-day 24) surgery. 18 controls with similar gestational age had one MRI (postnatal-day 23). Cortical gray matter volume (CGM), inner cortical surface (iCS) and median cortical thickness were extracted as measures of volumetric growth, and gyrification index (GI) as measure of maturation.\u3c/p\u3e\u3cp\u3eRESULTS: Over a median of 18 days CGM increased by 21%, iCS by 17%, thickness and GI both by 9%. Decreased post-operative CGM and iCS were seen for CHD compared to controls (p-values < 0.01), however with similar thickness and GI. UVH showed lower post-operative iCS, thickness (p-values < 0.05) and GI (p-value < 0.01) than d-TGA and controls. Infants requiring pre-operative balloon-atrioseptostomy (BAS, 61%) had reduced post-operative CGM, iCS and GI (p-values< 0.05).\u3c/p\u3e\u3cp\u3eCONCLUSIONS: Infants with severe CHD show reduced cortical volumes compared to controls with gyrification being delayed in UVH, but not in d-TGA. Infants requiring BAS show higher risk of impaired cortical volume and gyrification.\u3c/p\u3

Longitudinal Analysis of Fetal MRI in Patients with Prenatal Spina Bifida Repair

Open spina bifida (SB) is one of the most common congenital defects and can lead to impaired brain development. Emerging fetal surgery methods have shown considerable success in the treatment of patients with this severe anomaly. Afterwards, alterations in the brain development of these fetuses have been observed. Currently no longitudinal studies exist to show the effect of fetal surgery on brain development. In this work, we present a fetal MRI neuroimaging analysis pipeline for fetuses with SB, including automated fetal ventricle segmentation and deformation-based morphometry, and demonstrate its applicability with an analysis of ventricle enlargement in fetuses with SB. Using a robust super-resolution algorithm, we reconstructed fetal brains at both pre-operative and post-operative time points and trained a U-Net CNN in order to automatically segment the ventricles. We investigated the change of ventricle shape post-operatively, and the impacts of lesion size, type, and GA at operation on the change in ventricle shape. No impact was found. Prenatal ventricle volume growth was also investigated. Our method allows for the quantification of longitudinal morphological changes to fully quantify the impact of prenatal SB repair and could be applied to predict postnatal outcomes

Spectroscopic monitoring of NO traces in plants and human breath: applications and perspectives

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