Usefulness of serum albumin and serum total cholesterol in the prediction of hospital death in older patients with severe, acute heart failure

SummaryBackgroundAcute heart failure (HF) carries high hospital mortality rates in older patients; a multimarker strategy may help identify patients at high risk.AimsTo investigate prospectively the prognostic relevance of serum albumin and serum total cholesterol (TC) in older patients with severe, acute HF.MethodsUsual prognostic variables were collected on admission in 207 consecutive patients aged>70 years with severe, acute HF. Serum albumin and serum TC were obtained soon after clinical improvement.ResultsHospital mortality rate was 19%. Patients who died were similar to patients who survived in terms of age, sex, heart rate, serum haemoglobin and left ventricular ejection fraction. Patients who died had higher concentrations of B-type natriuretic peptide (BNP), blood urea nitrogen, serum creatinine, C-reactive protein and serum troponin I, lower systolic blood pressure, and lower concentrations of serum albumin and serum TC than patients who survived (P<0.01 for all). Serum albumin was the best independent predictor of hospital death (odds ratio 0.82 [0.74–0.90], P<0.001), with blood urea nitrogen (P=0.02) and log (BNP) (P=0.02). A simple risk score based on serum albumin (<3g/dL; 2 points), BNP (>840pg/mL; 1 point) and blood urea nitrogen (>15.3mmol/L; 1 point) discriminated patients without (score 0 to 1, hospital death 4%) from patients with (score 2 to 4, hospital death 35%, P<0.001) a high risk of death.ConclusionHypoalbuminaemia offers powerful additional prognostic information to usual prognostic variables in older patients with severe, acute HF, and deserves further attention in multimarker strategies

Mathematical framework for Traction Force Microscopy

International audienceThis paper deals with the Traction Force Microscopy (TFM) problem. It consists in obtaining stresses by solving an inverse problem in an elastic medium, from known experimentally measured displacements. In this article, the application is the determination of the stresses exerted by a living cell at the surface of an elastic gel. We propose an abstract framework which formulates this inverse problem as a constrained minimization problem. The mathematical constraints express the biomechanical conditions that the cell must satisfy. From this framework, two methods currently used can be derived, the adjoint method (AM) and the Fourier Transform Traction Cytometry (FTTC) method. An improvement of the FTTC method is also derived using this framework. The numerical results are compared and show the advantage of the AM, in particular it can capture details more accurately

Preliminary Analysis: Am-241 RHU/TEG Electric Power Source for Nanosatellites

The Februay 2013 Space Works Commercial report indicates a strong increase in nano/microsatellite (1-50 kg) launch demand globally in future years. Nanosatellites (NanoSats) are small spacecraft in the 1-10 kg range, which present a simple, low-cost option for developing quickly-deployable satellites. CubeSats, a special category of NanoSats, are even being considered for interplanetary missions. However, the small dimensions of CubeSats and the limited mass of the NanoSat class in general place limits of capability on their electrical power systems (especially where typical power sources such as solar panels are considered) and stored energy reserves; restricting the power budget and overall functionality. For example, leveraging NanoSat clusters for computationally intensive problems that are solved collectively becomes more challenging with power related restrictions on communication and data-processing. Further, interplanetary missions that would take NanoSats far from the sun, make the use of solar panels less effective as a power source as their required area would become quite large. To overcome these limitations, americium 241 (Am-241) has been suggested as a low power source option. The Idaho National Laboratory, Center for Space Nuclear Research reports that: (Production) requires small quantities of isotope - 62.5 g of Pu-238; 250 g Am- 241 (for 5 We); Am-241 is available at around 1 kg/yr commercially; Am-241 produces 59 kev gammas which are stopped readily by tungsten so the radiation field is very low. Whereby, an Am-241 source could be placed in among the instruments and the waste heat used to heat the platform; and amounts of isotope are so low that launch approval may be easier, especially with tungsten encapsulation. As further reported, Am-241 has a half-life that is approximately five times greater than that of Pu- 238 and it has been determined that the neutron yield of a 241-AmO(sub 2) source is approximately an order of magnitude lower than that of a 238-PuO(sub 2) source of equal mass and degree of (sup 16)O enrichment. Also it has been demonstrated that shielded heat sources fuelled by oxygen-enriched 238-PuO(sub 2) have masses that are up to 10 times greater than those fuelled by oxygenenriched 241-AmO(sub 2) with equivalent thermal power outputs and neutron dose rates at 1 m radii. For these reasons, Am-241 is well suited to missions that demand long duration electrical power output, such as deep spaceflight missions and similar missions that use radiation-hard electronics and instrumentation that are less susceptible to neutron radiation damage

Impedance spectroscopy characterization of neutron irradiated thermoelectric modules for space nuclear power

The European Space Agency is currently supporting the research and development of advanced radioisotope power systems utilising thermoelectric modules. The performance of thermoelectric modules following exposure to neutron radiation is of significant interest due to the likely application of radioisotope thermoelectric generators in deep space exploration or planetary landers requiring prolonged periods of operation. This study utilises impedance spectroscopy to characterise the effects of neutron irradiation on the performance of complete thermoelectric modules, as opposed to standalone material. For a 50 We americium-241 radioisotope thermoelectric generator design, it is estimated that the TE modules could be exposed to a total integrated flux of approximately 5 × 1013 neutrons cm-2 (>1 MeV). In this study, an equivalent neutron dose was simulated experimentally via an acute 2-hour exposure in a research pool reactor. Bi2Te3-based thermoelectric modules with different leg aspect ratios and microstructures were investigated. Gamma-ray spectroscopy was initially used to identify activated radionuclides and hence quantify irradiation induced transmutation doping. To evaluate the thermoelectric properties pre- and post-irradiation, impedance spectroscopy characterization was employed. Isochronal thermal annealing of defects imparted by the irradiation process, revealed that polycrystalline based modules required significantly higher temperature than those with a monolithic microstructure. Whilst this may indicate a greater susceptibility to neutron irradiation, all tested modules demonstrated sufficient radiation hardness for use within an americium-241 radioisotope thermoelectric generator. Furthermore, the work reported demonstrates that impedance spectroscopy is a highly capably diagnostic tool for characterising the in-service degradation of complete thermoelectric devices

Preliminary Analysis: Am-241 RHU/TEG Electric Power Source for Nanosatellites

No abstract availabl

Responsive glyco-poly(2-oxazoline)s: synthesis, cloud point tuning, and lectin binding

A new sugar-substituted 2-oxazoline monomer was prepared using the copper-catalyzed alkyne-azide cycloaddition (CuAAC) reaction. Its copolymerization with 2-ethyl-2-oxazoline as well as 2-(dec-9-enyl)-2-oxazoline, yielding well-defined copolymers with the possibility to tune the properties by thiol-ene "click" reactions, is described. Extensive solubility studies on the corresponding glycocopolymers demonstrated that the lower critical solution temperature behavior and pH-responsiveness of these copolymers can be adjusted in water and phosphate-buffered saline (PBS) depending on the choice of the thiol. By conjugation of 2,3,4,6-tetra-O-acetyl-1-thio-beta-D-glucopyranose and subsequent deprotection of the sugar moieties, the hydrophilicity of the copolymer could be increased significantly, allowing a cloud-point tuning in the physiological range. Furthermore, the binding capability of the glycosylated copoly(2-oxazoline) to concanavalin A was investigated

The international post-graduate Master programme for space exploration, SEEDS: education and training from a System Engineering perspective

The SEEDS (SpacE Exploration Development Systems) initiative was initially conceived and promoted by Politecnico di Torino and Thales Alenia Space-Italy in 2005. It aimed at establishing a post-graduate International Master Program in space exploration to offer an opportunity to young engineers to get prepared for the future of Europe in space and specifically in human space exploration. ISAE-Supaero in France and University of Leicester in UK participate to SEEDS together with Politecnico di Torino (Italy). Turin, Toulouse and Leicester have a long common tradition of space activities at both the industrial and academic level and within the SEEDS initiative they represent three poles of European cooperation in space programs. The Master course comprises two different steps in sequence: an initial learning phase and a Project Work phase. Both phases pursue a multidisciplinary approach, where all specialized disciplines are integrated to make the students able to acquire the system view and then to accomplish the conceptual design of a selected case-study. The distinguishing feature of SEEDS is the Project Work activity, performed by all students together under the supervision of academic and industrial tutors. Main objective of the Project Work is to train the students on the basic principles of the system engineering design, through their application to a well-defined project related to a specific human space exploration mission. The Project Work includes the Preparatory Work, during which the students identify the complete architecture and overall scenario of the mission, and the conceptual design activities, performed in the three European sites to develop a limited number of building blocks. Seven academic years of activities have passed and seven project works have been successfully completed, dealing with various space exploration themes. The eighth edition is currently under way with the aim of designing a “Transit and return habitable Mars orbital port”. The paper focuses on the description of the Master Program, both from the point of view of its contents, structure and multidisciplinary design methodologies, and on the main results achieved in terms of Project Work activities. The positive experience of seven years of SEEDS is brought to evidence and the lessons learned are discussed

Electrochemical sulfidation of WS2 nanoarrays:strong dependence of hydrogen evolution activity on transition metal sulfide surface composition

The activity of transition metal sulfides for the hydrogen evolution reaction (HER) can be increased by sulfur-enrichment of active metal-sulfide sites. In this report, we investigate the electrochemical sulfidation of atmospherically aged WS2 nanoarrays with respect to enhancing HER activity. In contrast to MoS2, it is found that sulfidation diminishes HER activity. Electrochemical and XPS experiments suggest the involvement of insoluble tungsten oxides in the altered HER and electron transfer properties. This demonstrates the strong dependence of the transition metal dichalcogenide (TMD) composition with the successful sulfur incorporation and subsequent HER activity

A high-throughput splinkerette-PCR method for the isolation and sequencing of retroviral insertion sites

Insertional mutagens such as viruses and transposons are a useful tool for performing forward genetic screens in mice to discover cancer genes. These screens are most effective when performed using hundreds of mice, however until recently a major limitation to performing screens on this scale has been the cost effective isolation and sequencing of insertion sites. Here we present a method for the high-throughput isolation of insertion sites using a highly efficient splinkerette-PCR method coupled with capillary or 454 sequencing. This protocol includes a description of the procedure for DNA isolation, DNA digestion, linker or splinkerette ligation, primary and secondary PCR amplification, and sequencing. This method, which takes about 1 week to perform, has allowed us to isolate hundreds of thousands of insertion sites from mouse tumours and, unlike other methods, has been specifically optimised for the isolation of insertion sites generated with the murine leukaemia virus (MuLV), and can easily be performed in 96 well plate format for the efficient multiplex isolation of insertion sites

The large area detector onboard the eXTP mission

The Large Area Detector (LAD) is the high-throughput, spectral-timing instrument onboard the eXTP mission, a flagship mission of the Chinese Academy of Sciences and the China National Space Administration, with a large European participation coordinated by Italy and Spain. The eXTP mission is currently performing its phase B study, with a target launch at the end-2027. The eXTP scientific payload includes four instruments (SFA, PFA, LAD and WFM) offering unprecedented simultaneous wide-band X-ray timing and polarimetry sensitivity. The LAD instrument is based on the design originally proposed for the LOFT mission. It envisages a deployed 3.2 m2 effective area in the 2-30 keV energy range, achieved through the technology of the large-area Silicon Drift Detectors - offering a spectral resolution of up to 200 eV FWHM at 6 keV - and of capillary plate collimators - limiting the field of view to about 1 degree. In this paper we will provide an overview of the LAD instrument design, its current status of development and anticipated performance