1,801 research outputs found
Left main bronchus compression due to main pulmonary artery dilatation in pulmonary hypertension: two case reports
Abstract. Pulmonary arterial dilatation associated with pulmonary hypertension may result in significant compression of local structures. Left main coronary artery and left recurrent laryngeal nerve compression have been described. Tracheobronchial compression from pulmonary arterial dilatation is rare in adults, and there are no reports in the literature of its occurrence in idiopathic pulmonary arterial hypertension. Compression in infants with congenital heart disease has been well described. We report 2 cases of tracheobronchial compression: first, an adult patient with idiopathic pulmonary arterial hypertension who presents with symptomatic left main bronchus compression, and second, an adult patient with Eisenmenger ventricular septal defect and right-sided aortic arch, with progressive intermedius and right middle lobe bronchi compression in association with enlarged pulmonary arteries
The Cultural and Commercial Value of Tulsi (Ocimum tenuiflorum L.): Multidisciplinary Approaches Focusing on Species Authentication
Tulsi (Holy basil, Ocimum tenuiflorum L., Lamiaceae), native to Asia, has become globalised as the cultural, cosmetic, and medicinal uses of the herb have been popularised. DNA barcoding, a molecular technique used to identify species based on short regions of DNA, can discriminate between different species and identify contaminants and adulterants. This study aimed to explore the values associated with Tulsi in the United Kingdom (UK) and authenticate samples using DNA barcoding. A mixed methods approach was used, incorporating social research (i.e., structured interviews) and DNA barcoding of Ocimum samples using the ITS and trnH-psbA barcode regions. Interviews revealed the cultural significance of Tulsi: including origins, knowledge exchange, religious connotations, and medicinal uses. With migration, sharing of plants and seeds has been seen as Tulsi plants are widely grown in South Asian (SA) households across the UK. Vouchered Ocimum specimens (n = 33) were obtained to create reference DNA barcodes which were not available in databases. A potential species substitution of O. gratissimum instead of O. tenuiflorum amongst SA participants was uncovered. Commercial samples (n = 47) were difficult to authenticate, potentially due to DNA degradation during manufacturing processes. This study highlights the cultural significance of Tulsi, despite a potential species substitution, the plant holds a prestigious place amongst SA families in the UK. DNA barcoding was a reliable way to authenticate Ocimum species
Exercise cardiac MRI unmasks right ventricular dysfunction in acute hypoxia and chronic pulmonary arterial hypertension
Background - Coupling of right ventricular (RV) contractility to afterload is maintained at rest in the early stages of pulmonary arterial hypertension (PAH), but exercise may unmask depleted contractile reserves. We assessed whether elevated afterload reduces RV contractile reserve despite compensated resting function using non-invasive exercise imaging. Methods and Results - Fourteen patients with PAH (mean age 39.1 years, 10 females) and 34 healthy control subjects (mean age 35.6 years, 17 females) completed real-time cardiac magnetic resonance imaging during sub-maximal exercise breathing room-air. Controls were then also exercised during acute normobaric hypoxia (FiO2 12%). RV contractile reserve was assessed by the effect of exercise on ejection fraction (RVEF). In control subjects the increase in RVEF on exercise was less during hypoxia (P=0.017), but the response of left ventricular ejection fraction to exercise did not change. Patients with PAH had impaired RV reserve with half demonstrating a fall in RVEF on exercise despite comparable resting function to controls (PAH: rest 53.6{plus minus}4.3% vs exercise 51.4{plus minus}10.7%; controls: rest 57.1{plus minus}5.2% vs exercise 69.6{plus minus}6.1%, P<0.0001). In control subjects the increase in stroke volume index (SVi) on exercise was driven by reduced RV end-systolic volume, whereas PAH patients did not augment SVi, with increases in both end-diastolic and end-systolic volumes. From baseline hemodynamic and exercise capacity variables only VE/VCO2 was an independent predictor of RV functional reserve (P=0.021). Conclusions - Non-invasive cardiac imaging during exercise unmasks depleted RV contractile reserves in healthy adults under hypoxic conditions and PAH patients under normoxic conditions despite preserved ejection fraction
Propagation of an Earth-directed coronal mass ejection in three dimensions
Solar coronal mass ejections (CMEs) are the most significant drivers of
adverse space weather at Earth, but the physics governing their propagation
through the heliosphere is not well understood. While stereoscopic imaging of
CMEs with the Solar Terrestrial Relations Observatory (STEREO) has provided
some insight into their three-dimensional (3D) propagation, the mechanisms
governing their evolution remain unclear due to difficulties in reconstructing
their true 3D structure. Here we use a new elliptical tie-pointing technique to
reconstruct a full CME front in 3D, enabling us to quantify its deflected
trajectory from high latitudes along the ecliptic, and measure its increasing
angular width and propagation from 2-46 solar radii (approximately 0.2 AU).
Beyond 7 solar radii, we show that its motion is determined by an aerodynamic
drag in the solar wind and, using our reconstruction as input for a 3D
magnetohydrodynamic simulation, we determine an accurate arrival time at the
Lagrangian L1 point near Earth.Comment: 5 figures, 2 supplementary movie
Arsenic mitigation: water quality of dug wells and tubewells
Arsenic concentration in very shallow and deep aquifers is comparatively lower than shallow aquifers in arsenic contaminated
areas. As a result, dug wells and deep tubewells have emerged as two major water supply options for populations
exposed to high levels of arsenic through drinking contaminated shallow tubewell water in Bangladesh and West Bengal
(India). The concentrations of other impurities of health concern also vary with depth and other characteristics of the aquifer.
Hence, shifting from one source to another may be the cause of exposure to health risk of a different nature. This paper
presents an assessment of water quality of dug wells (DW) and deep tubewells (DTW) as compared to shallow tubewells
(STW) for water supply. The results show that a shift from STW to DW reduces median arsenic ingestion from 151 μg/L
(Mean 172μg/L) to 0.74 μg/L(mean 7.92μg/L), while DTW further reduces median arsenic ingestion to 0.41μg/L (mean
1.05μg/L). On the other hand, microbial contamination indicated by median value of Thermotolerant Coliform (TTC) count
was found to be 48 cfu/100ml for DW water as compared to 0 cfu/100ml for both STW and DTW waters
Do Interventions Designed to Support Shared Decision-Making Reduce Health Inequalities? : A Systematic Review and Meta-Analysis
Copyright: © 2014 Durand et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Background: Increasing patient engagement in healthcare has become a health policy priority. However, there has been concern that promoting supported shared decision-making could increase health inequalities. Objective: To evaluate the impact of SDM interventions on disadvantaged groups and health inequalities. Design: Systematic review and meta-analysis of randomised controlled trials and observational studies.Peer reviewe
Measuring the Hidden Aspects of Solar Magnetism
2008 marks the 100th anniversary of the discovery of astrophysical magnetic
fields, when George Ellery Hale recorded the Zeeman splitting of spectral lines
in sunspots. With the introduction of Babcock's photoelectric magnetograph it
soon became clear that the Sun's magnetic field outside sunspots is extremely
structured. The field strengths that were measured were found to get larger
when the spatial resolution was improved. It was therefore necessary to come up
with methods to go beyond the spatial resolution limit and diagnose the
intrinsic magnetic-field properties without dependence on the quality of the
telescope used. The line-ratio technique that was developed in the early 1970s
revealed a picture where most flux that we see in magnetograms originates in
highly bundled, kG fields with a tiny volume filling factor. This led to
interpretations in terms of discrete, strong-field magnetic flux tubes embedded
in a rather field-free medium, and a whole industry of flux tube models at
increasing levels of sophistication. This magnetic-field paradigm has now been
shattered with the advent of high-precision imaging polarimeters that allow us
to apply the so-called "Second Solar Spectrum" to diagnose aspects of solar
magnetism that have been hidden to Zeeman diagnostics. It is found that the
bulk of the photospheric volume is seething with intermediately strong, tangled
fields. In the new paradigm the field behaves like a fractal with a high degree
of self-similarity, spanning about 8 orders of magnitude in scale size, down to
scales of order 10 m.Comment: To appear in "Magnetic Coupling between the Interior and the
Atmosphere of the Sun", eds. S.S. Hasan and R.J. Rutten, Astrophysics and
Space Science Proceedings, Springer-Verlag, Heidelberg, Berlin, 200
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Powering the ABC multidrug exporter LmrA: How nucleotides embrace the ion-motive force.
LmrA is a bacterial ATP-binding cassette (ABC) multidrug exporter that uses metabolic energy to transport ions, cytotoxic drugs, and lipids. Voltage clamping in a Port-a-Patch was used to monitor electrical currents associated with the transport of monovalent cationic HEPES+ by single-LmrA transporters and ensembles of transporters. In these experiments, one proton and one chloride ion are effluxed together with each HEPES+ ion out of the inner compartment, whereas two sodium ions are transported into this compartment. Consequently, the sodium-motive force (interior negative and low) can drive this electrogenic ion exchange mechanism in cells under physiological conditions. The same mechanism is also relevant for the efflux of monovalent cationic ethidium, a typical multidrug transporter substrate. Studies in the presence of Mg-ATP (adenosine 5'-triphosphate) show that ion-coupled HEPES+ transport is associated with ATP-bound LmrA, whereas ion-coupled ethidium transport requires ATP binding and hydrolysis. HEPES+ is highly soluble in a water-based environment, whereas ethidium has a strong preference for residence in the water-repelling plasma membrane. We conclude that the mechanism of the ABC transporter LmrA is fundamentally related to that of an ion antiporter that uses extra steps (ATP binding and hydrolysis) to retrieve and transport membrane-soluble substrates from the phospholipid bilayer.This research was supported by the Biotechnology and Biological Sciences Research Council grants BB/R00224X/1, BB/I002383/1 and BB/K017713/1, and Medical Research Council grant G0401165 (to H.W.V.V.). We are also grateful for funding by the Human Frontier Science Program (grant RGP0034/2013), Strategic International Cooperative Program (Japan Science and Technology Agency, Japan) and Royal Society (UK) for collaborative research between H.W.V.V. and S.M. C.H.F.L. received a research studentship of Peterhouse, Cambridge. Y.S.K.K. received a Federal Training Award from the Ministry of Health in Malaysia. H.S. and S.R. were supported by the Cambridge Commonwealth, European and International Trust
Pathological and ecological host consequences of infection by an introduced fish parasite
The infection consequences of the introduced cestode fish parasite Bothriocephalus acheilognathi were studied in a cohort of wild, young-of-the-year common carp Cyprinus carpio that lacked co-evolution with the parasite. Within the cohort, parasite prevalence was 42% and parasite burdens were up to 12% body weight. Pathological changes within the intestinal tract of parasitized carp included distension of the gut wall, epithelial compression and degeneration, pressure necrosis and varied inflammatory changes. These were most pronounced in regions containing the largest proportion of mature proglottids. Although the body lengths of parasitized and non-parasitized fish were not significantly different, parasitized fish were of lower body condition and reduced weight compared to non-parasitized conspecifics. Stable isotope analysis (δ15N and δ13C) revealed trophic impacts associated with infection, particularly for δ15N where values for parasitized fish were significantly reduced as their parasite burden increased. In a controlled aquarium environment where the fish were fed ad libitum on an identical food source, there was no significant difference in values of δ15N and δ13C between parasitized and non-parasitized fish. The growth consequences remained, however, with parasitized fish growing significantly slower than non-parasitized fish, with their feeding rate (items s−1) also significantly lower. Thus, infection by an introduced parasite had multiple pathological, ecological and trophic impacts on a host with no experience of the parasite
Apple Sauce Improves Detection of Esophageal Motor Dysfunction During High-Resolution Manometry Evaluation of Dysphagia
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