751 research outputs found
Localisation of [131I]MIBG in nude mice bearing SK-N-SH human neuroblastoma xenografts: effect of specific activity.
The biodistribution of no-carrier-added (n.c.a.) meta-[131I]iodobenzylguanidine ([131I]MIBG) and that prepared by the standard isotopic exchange method were compared in athymic mice bearing SK-N-SH human neuroblastoma xenografts. No advantage in tumour uptake was observed for the n.c.a. preparation. BALB/c nu/nu mice exhibited lower uptake in highly innervated normal tissues (heart and adrenals) than normal BALB/c mice. In another experiment, the distribution of n.c.a. [131I]MIBG in the absence or presence (3-9 micrograms) of MIBG carrier was determined. At both 4 h and 24 h, the heart uptake was reduced by a factor of 1.5 even at a dose of 3 micrograms MIBG. Tumour uptake was not significantly altered by various amounts of unlabelled MIBG at either time point
Long-term outcomes after percutaneous revascularization of complex coronary bifurcation lesions using a dedicated self-expanding biolimus-eluting stent system
Background: To evaluate long-term clinical outcomes after treatment of complex bifurcation lesions with the AXXESS dedicated self-expanding biolimus A9-eluting bifurcation stent.Methods: Between 2004 and 2013, 123 patients with complex bifurcation lesions were treated in a single-center with the AXXESS stent in the proximal main vessel (MV) and additional drug-eluting stents in branches when required. Median follow-up was 5 years. Primary endpoint was the rate of major adverse cardiac events (MACE). Secondary endpoints included MACE components (cardiac death, non-periprocedural clinical myocardial infarction [MI], target lesion revascularization [TLR] and definite/probable stent thrombosis [ST]) as well as all-cause death, target vessel revascularization (TVR) and non-TVR.Results: During follow-up, 11 (8.9%) patients experienced a MACE, of whom 2 (1.6%) suffered cardiac death, 2 (1.6%) had a non-periprocedural clinical MI requiring TLR, and 7 (5.7%) underwent elective TLR. No definite/probable ST was observed. All-cause death occurred in 9 (7.3%) patients, TVR in 11 (8.9%) and non-TVR in 11 (8.9%). Patients treated for left main (LM) bifurcation lesions were more likely to experience MACE than non-LM bifurcation lesions (25% vs. 6.5%, p = 0.04).Conclusions: Percutaneous revascularization of complex bifurcation lesions with the AXXESS stent is safe and provides excellent long-term results, especially in non-LM lesions
Highlights of the ERS Lung Science Conference 2022
This article presents the highlights of the ERS Lung Science Conference 2022, including a session organised by the Early Career Member Committee (ECMC) dedicated to career development https://bit.ly/3tarCXc
Every year, the European Respiratory Society (ERS) organises the Lung Science Conference (LSC), in Estoril, to discuss basic and translational science. The topic of the 20th LSC was “Mucosal immunology of the lung: balancing protective immunity and chronic inflammation”. This was the first time that the LSC was organised as a hybrid congress with both in person and online attendance. In addition to an outstanding scientific programme, the LSC provides excellent opportunities for career development and inclusion of early career members (ECMs). All scientific and poster sessions are chaired by an ECM who is paired with a senior faculty to allow ECMs to become acquainted with session chairing, and there is a session organised by the Early Career Member Committee (ECMC) dedicated to career development. Moreover, travel bursaries are made available to abstract authors, and all bursary recipients and first-time attendees are invited to take part in a mentorship lunch. In this article, we provide the names of the ECM awardees and describe the scientific highlights of the LSC 2022 for those who could not attend.info:eu-repo/semantics/publishedVersio
A note on the fluxes of abiogenic methane and hydrogen from mid-ocean ridges
The concentrations of methane and hydrogen in hydrothermal vent fluids issuing from mid-ocean ridges tend to fall into two groups, one with high concentrations of these gases in ultramafic-hosted vent fields and a second group with relatively lower concentrations in basalt-hosted vent fluids. Ultramafic-hosted systems, however, appear to be restricted to slow-spreading ridges and constitute only a fraction of the hydrothermal systems found there. In this note, the hydrothermal fluxes of methane and hydrogen have been calculated by estimating the percentages of the total subsurface hydrothermal circulation that circulate through each type of host rock. Even though the percentage of the total subsurface flow that is affected by serpentinization appears to be rather small (8%), it still appears that this process produces about 70% of the total mid-ocean flux of these gases. The total production of methane and hydrogen is calculated to be about 20 x 10(9) mol yr(-1) and 190 x 10(9) mol yr(-1), respectively. The hydrogen flux is comparable to that most recently calculated on the basis of the rate of hydration of mantle rock in newly formed crust and the stoichiometry of the serpentinization reaction. This suggests that, except for the production of methane, a major portion of the hydrogen produced in the subsurface is not consumed before venting
Aborted propagation of the Ethiopian rift caused by linkage with the Kenyan rift
International audienceContinental rift systems form by propagation of isolated rift segments that interact, and eventually evolve into continuous zones of deformation. This process impacts many aspects of rifting including rift morphology at breakup, and eventual ocean-ridge segmentation. Yet, rift segment growth and interaction remain enigmatic. Here we present geological data from the poorly documented Ririba rift (South Ethiopia) that reveals how two major sectors of the East African rift, the Kenyan and Ethiopian rifts, interact. We show that the Ririba rift formed from the southward propagation of the Ethiopian rift during the Pliocene but this propagation was short-lived and aborted close to the Pliocene-Pleistocene boundary. Seismicity data support the abandonment of laterally offset, overlapping tips of the Ethiopian and Kenyan rifts. Integration with new numerical models indicates that rift abandonment resulted from progressive focusing of the tectonic and magmatic activity into an oblique, throughgoing rift zone of near pure extension directly connecting the rift sectors
Dissolution dominating calcification process in polar pteropods close to the point of aragonite undersaturation
Thecosome pteropods are abundant upper-ocean zooplankton that build aragonite shells. Ocean acidification results in the lowering of aragonite saturation levels in the surface layers, and several incubation studies have shown that rates of calcification in these organisms decrease as a result. This study provides a weight-specific net calcification rate function for thecosome pteropods that includes both rates of dissolution and calcification over a range of plausible future aragonite saturation states (Omega_Ar). We measured gross dissolution in the pteropod Limacina helicina antarctica in the Scotia Sea (Southern Ocean) by incubating living specimens across a range of aragonite saturation states for a maximum of 14 days. Specimens started dissolving almost immediately upon exposure to undersaturated conditions (Omega_Ar,0.8), losing 1.4% of shell mass per day. The observed rate of gross dissolution was different from that predicted by rate law kinetics of aragonite dissolution, in being higher at Var levels slightly above 1 and lower at Omega_Ar levels of between 1 and 0.8. This indicates that shell mass is affected by even transitional levels of saturation, but there is, nevertheless, some partial means of protection for shells when in undersaturated conditions. A function for gross dissolution against Var derived from the present observations was compared to a function for gross calcification derived by a different study, and showed that dissolution became the dominating process even at Omega_Ar levels close to 1, with net shell growth ceasing at an Omega_Ar of 1.03. Gross dissolution increasingly dominated net change in shell mass as saturation levels decreased below 1. As well as influencing their viability, such dissolution of pteropod shells in the surface layers will result in slower sinking velocities and decreased carbon and carbonate fluxes to the deep ocean
Marathon related death due to brainstem herniation in rehydration-related hyponatraemia: a case report
Introduction: Identifying marathon runners at risk of neurological deterioration at the end of the race (within a large cohort complaining of exhaustion, dehydration, nausea, headache, dizziness, etc.) is challenging. Here we report a case of rehydration-related hyponatraemia with ensuing brain herniation.
Case presentation: We report the death of runner in his 30's who collapsed in the recovery area following a marathon. Following rehydration he developed a respiratory arrest in the emergency room. He was found to be hyponatraemic (130 mM). A CT brain scan showed severe hydrocephalus and brain stem herniation. Despite emergency insertion of an extraventricular drain, he was tested for brainstem death the following morning. Funduscopy demonstrated an acute-on-chronic papilledema; CSF spectrophotometry did not reveal any trace of oxyhemoglobin or bilirubin, but ferritin levels were considerably raised (530 ng/mL, upper reference value 12 ng/mL), consistent with a previous bleed. Retrospectively it emerged that the patient had suffered from a thunderclap headache some months earlier. Subsequently he developed morning headaches and nausea. This suggests that he may have suffered from a subarachnoid haemorrhage complicated by secondary hydrocephalus. This would explain why in this case the relatively mild rehydration-related hyponatremia may have caused brain swelling sufficient for herniation.
Conclusion: Given the frequency of hyponatraemia in marathon runners (serum Na <135 mM in about 13%), and the non-specific symptoms, we discuss how a simple screening test such as funduscopy may help to identify those who require urgent neuroimaging
Computer simulations of domain growth and phase separation in two-dimensional binary immiscible fluids using dissipative particle dynamics
We investigate the dynamical behavior of binary fluid systems in two
dimensions using dissipative particle dynamics. We find that following a
symmetric quench the domain size R(t) grows with time t according to two
distinct algebraic laws R(t) = t^n: at early times n = 1/2, while for later
times n = 2/3. Following an asymmetric quench we observe only n = 1/2, and if
momentum conservation is violated we see n = 1/3 at early times. Bubble
simulations confirm the existence of a finite surface tension and the validity
of Laplace's law. Our results are compared with similar simulations which have
been performed previously using molecular dynamics, lattice-gas and
lattice-Boltzmann automata, and Langevin dynamics. We conclude that dissipative
particle dynamics is a promising method for simulating fluid properties in such
systems.Comment: RevTeX; 22 pages, 5 low-resolution figures. For full-resolution
figures, connect to http://www.tcm.phy.cam.ac.uk/~ken21/tension/tension.htm
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