Obstructive sleep apnoea-related respiratory events and desaturation severity are associated with the cardiac response

Obstructive sleep apnoea (OSA) causes, among other things, intermittent blood oxygen desaturations, increasing the sympathetic tone. Yet the effect of desaturations on heart rate variability (HRV), a simple and noninvasive method for assessing sympathovagal balance, has not been comprehensively studied. We aimed to study whether desaturation severity affects the immediate HRV.MethodsWe retrospectively analysed the electrocardiography signals in 5-min segments (n=39 132) recorded during clinical polysomnographies of 642 patients with suspected OSA. HRV parameters were calculated for each segment. The segments were pooled into severity groups based on the desaturation severity (i.e.the integrated area under the blood oxygen saturation curve) and the respiratory event rate within the segment. Covariate-adjusted regression analyses were performed to investigate possible confounding effects.ResultsWith increasing respiratory event rate, the normalised high-frequency band power (HFNU) decreased from 0.517 to 0.364 (p<0.01), the normalised low-frequency band power (LFNU) increased from 0.483 to 0.636 (p<0.01) and the mean RR interval decreased from 915 to 869 ms (p<0.01). Similarly, with increasing desaturation severity, the HFNUdecreased from 0.499 to 0.364 (p<0.01), the LFNUincreased from 0.501 to 0.636 (p<0.01) and the mean RR interval decreased from 952 to 854 ms (p<0.01). Desaturation severity-related findings were confirmed by considering the confounding factors in the regression analyses.ConclusionThe short-term HRV response differs based on the desaturation severity and the respiratory event rate in patients with suspected OSA. Therefore, a more detailed analysis of HRV and desaturation characteristics could enhance OSA severity estimation

Efficacy of salbutamol via Easyhaler®unaffected by low inspiratory flow

AbstractThe fine particle dose delivered via dry powder inhalers (DPIs) is often affected by the inspiratory flow rate generated during inhalation. This has clinical implications, since the fine particle dose determines the amount of drug reaching the lungs. With Easyhaler®DPI the fine particle dose remains relatively constant over the range of inspiratory flow rates from 30–60 l min−1. The aim of this study was to confirm that clinical efficacy is maintained even at low flow rates by comparing the bronchodilating effect of salbutamol (100 μ g) delivered via Easyhaler®at a target inspiratory flow of 30 l min−1with the same dose of salbutamol via pressurised metered-dose inhaler (pMDI) plus spacer.This was a double-blind, randomized, cross-over study with double-dummy technique. Twenty-one paediatric and adult asthmatic patients completed the study, which was conducted over 2 study days. The main outcome parameter was forced expiratory volume in 1 sec (FEV1). The patients were trained to generate a low peak inspiratory flow rate (PIFR) of 30 l min−1, and the actual PIFR through Easyhaler®was recorded.The average PIFR through Easyhaler®was 28·7 l min−1. The difference in the maximum value of FEV1(FEV1max) between the treatments after drug inhalation was 0·01 l. The mean of FEV1maxwas 2·67 l after pMDI plus spacer compared to 2·69 l after Easyhaler®. Improvements in FEV1were clinically significant. No significant differences between treatments were found.A reasonably low inspiratory flow rate through Easyhaler®produces an equivalent improvement in lung function to a correctly used pMDI plus spacer. Hence, Easyhaler®can be used with confidence in patients who may have difficulty in generating a high inspiratory flow rate, such as children and the elderly

Cantilever-Enhanced Photoacoustic Spectroscopy of Radioactive Methane

We report the first high-resolution spectroscopy study of radiocarbon methane, 14CH4. Several absorption lines of the fundamental vibrational band v3 were measured using a continuous-wave mid-infrared optical parametric oscillator with cantilever-enhanced photoacoustic spectroscopy. © 2020 OSA.Peer reviewe

MTT's berry varieties - rich in phytochemicals

The realized importance of the phytochemical quality of berries in human nutrition has given new focus and importance to berry breeding programs. The breeding work at MTT achieves to keep the inner quality of berries at high level, and even increase it, in addition to reach the agronomic breeding targets in the changing climatic conditions in the North

Performance of the FMI cosine error correction method for the Brewer spectral UV measurements

Non-ideal angular response of a spectroradiometer is a well-known error source of spectral UV measurements and for that reason instrument specific cosine error correction is applied. In this paper, the performance of the cosine error correction method of Brewer spectral UV measurements in use at the Finnish Meteorological Institute (FMI) is studied. Ideally, the correction depends on the actual sky radiation distribution, which can change even during one spectral scan due to rapid changes in cloudiness. The FMI method has been developed to take into account the changes in the ratio of direct to diffuse sky radiation and it derives a correction coefficient for each measured wavelength. Measurements of five Brewers were corrected for the cosine error and the results were compared to the reference travelling spectroradiometer (QASUME). Measurements were performed during the RBCC-E (Regional Brewer Calibration Center – Europe) X Campaign held at El Arenosillo, Huelva (37°&thinsp;N, 7°&thinsp;W), Spain, in 2015. In addition, results of site audits of FMI's Brewers in Sodankylä (67°&thinsp;N, 27°&thinsp;E) and Jokioinen (61°&thinsp;N, 24°&thinsp;E) during 2002–2014 were studied. The results show that the spectral cosine error correction varied between 4 and 14&thinsp;%. After that the correction was applied to Brewer UV spectra the relative differences between the QASUME and the Brewer diminished even by 10&thinsp;%. The study confirms that the method, originally developed for measurements at high latitudes, can be used at mid-latitudes as well. The method is applicable to other Brewers as far as the required input parameters, i.e. total ozone, aerosol information, albedo, instrument specific angular response and slit function are available.</p

High genetic diversity at the extreme range edge: nucleotide variation at nuclear loci in Scots pine (Pinus sylvestris L.) in Scotland

Nucleotide polymorphism at 12 nuclear loci was studied in Scots pine populations across an environmental gradient in Scotland, to evaluate the impacts of demographic history and selection on genetic diversity. At eight loci, diversity patterns were compared between Scottish and continental European populations. At these loci, a similar level of diversity (θsil=~0.01) was found in Scottish vs mainland European populations, contrary to expectations for recent colonization, however, less rapid decay of linkage disequilibrium was observed in the former (ρ=0.0086±0.0009, ρ=0.0245±0.0022, respectively). Scottish populations also showed a deficit of rare nucleotide variants (multi-locus Tajima's D=0.316 vs D=−0.379) and differed significantly from mainland populations in allelic frequency and/or haplotype structure at several loci. Within Scotland, western populations showed slightly reduced nucleotide diversity (πtot=0.0068) compared with those from the south and east (0.0079 and 0.0083, respectively) and about three times higher recombination to diversity ratio (ρ/θ=0.71 vs 0.15 and 0.18, respectively). By comparison with results from coalescent simulations, the observed allelic frequency spectrum in the western populations was compatible with a relatively recent bottleneck (0.00175 × 4Ne generations) that reduced the population to about 2% of the present size. However, heterogeneity in the allelic frequency distribution among geographical regions in Scotland suggests that subsequent admixture of populations with different demographic histories may also have played a role

Identification of genetic alterations in pancreatic cancer by the combined use of tissue microdissection and array-based comparative genomic hybridisation

Pancreatic ductal adenocarcinoma (PDAC) is characterised pathologically by a marked desmoplastic stromal reaction that significantly reduces the sensitivity and specificity of cytogenetic analysis. To identify genetic alterations that reflect the characteristics of the tumour in vivo, we screened a total of 23 microdissected PDAC tissue samples using array-based comparative genomic hybridisation (array CGH) with 1 Mb resolution. Highly stringent statistical analysis enabled us to define the regions of nonrandom genomic changes. We detected a total of 41 contiguous regions (>3.0 Mb) of copy number changes, such as a genetic gain at 7p22.2–p15.1 (26.0 Mb) and losses at 17p13.3–p11.2 (13.6 Mb), 18q21.2–q22.1 (12.0 Mb), 18q22.3–q23 (7.1 Mb) and 18q12.3–q21.2 (6.9 Mb). To validate our array CGH results, fluorescence in situ hybridisation was performed using four probes from those regions, showing that these genetic alterations were observed in 37–68% of a separate sample set of 19 PDAC cases. In particular, deletion of the SEC11L3 gene (18q21.32) was detected at a very high frequency (13 out of 19 cases; 68%) and in situ RNA hybridisation for this gene demonstrated a significant correlation between deletion and expression levels. It was further confirmed by reverse transcription–PCR that SEC11L3 mRNA was downregulated in 16 out of 16 PDAC tissues (100%). In conclusion, the combination of tissue microdissection and array CGH provided a valid data set that represents in vivo genetic changes in PDAC. Our results raise the possibility that the SEC11L3 gene may play a role as a tumour suppressor in this disease