159 research outputs found
The hGFAP-driven conditional TSPO knockout is protective in a mouse model of multiple sclerosis.
The mitochondrial translocator protein (TSPO) has been implicated in CNS diseases. Here, we sought to determine the specific role of TSPO in experimental autoimmune encephalomyelitis (EAE), the most studied animal model of multiple sclerosis (MS). To fundamentally elucidate the functions of TSPO, we first developed a viable TSPO knockout mouse. A conditional TSPO knockout mouse was generated by utilizing the Cre-Lox system. We generated a TSPO floxed mouse, and then crossed this mouse with a Cre recombinase expressing mouse driven by the human glial fibrillary acidic protein (hGFAP) promoter. The resultant mouse was a neural linage line specific TSPO knockout. The loss of TSPO in the CNS did not result in overt developmental defects or phenotypes. The TSPO-/- mouse showed a decrease in GFAP expression, correlating with a decrease in astrogliosis in response to neural injury during EAE. This decrease in astrogliosis was also witnessed in the lessening of severity of EAE clinical scoring, indicating an in vivo functional role for TSPO in suppressing EAE. The TSPO-/- mouse could be a useful tool in better understanding the role of TSPO in CNS disease, and our results implicate TSPO as a potential therapeutic target in MS
Influence of Yttrium on the Thermal Stability of Ti-Al-N Thin Films
Ti(1-x)Al(x)N coated tools are commonly used in high-speed machining, where the cutting edge of an end-mill or insert is exposed to temperatures up to 1100 degrees C. Here, we investigate the effect of Yttrium addition on the thermal stability of Ti(1-x)Al(x)N coatings. Reactive DC magnetron sputtering of powder metallurgically prepared Ti(0.50)Al(0.50), Ti(0.49)Al(0.49)Y(0.02), and Ti(0.46)Al(0.46)Y(0.08) targets result in the formation of single-phase cubic (c) Ti(0.45)Al(0.55)N, binary cubic/wurtzite c/w-Ti(0.41)Al(0.57)Y(0.02)N and singe-phase w-Ti(0.38)Al(0.54)Y(0.08)N coatings. Using pulsed DC reactive magnetron sputtering for the Ti(0.49)Al(0.49)Y(0.02) target allows preparing single-phase c-Ti(0.46)Al(0.52)Y(0.02)N coatings. By employing thermal analyses in combination with X-ray diffraction and transmission electron microscopy investigations of as deposited and annealed (in He atmosphere) samples, we revealed that Y effectively retards the decomposition of the Ti(1-x-y)Al(x)Y(y)N solid-solution to higher temperatures and promotes the precipitation of c-TiN, c-YN, and w-AlN. Due to their different microstructure and morphology already in the as deposited state, the hardness of the coatings decreases from similar to 35 to 22 GPa with increasing Y-content and increasing wurtzite phase fraction. Highest peak hardness of similar to 38 GPa is obtained for the Y-free c-Ti(0.45)Al(0.55)N coating after annealing at T(a) = 950 degrees C, due to spinodal decomposition. After annealing above 1000 degrees C the highest hardness is obtained for the 2 mol % YN containing c-Ti(0.46)Al(0.52)Y(0.02)N coating with similar to 29 and 28 GPa for T(a) = 1150 and 1200 degrees C, respectively
Towards predictive modelling of near-edge structures in electron energy loss spectra of AlN based ternary alloys
Although electron energy loss near edge structure analysis provides a tool
for experimentally probing unoccupied density of states, a detailed comparison
with simulations is necessary in order to understand the origin of individual
peaks. This paper presents a density functional theory based technique for
predicting the N K-edge for ternary (quasi-binary) nitrogen alloys by adopting
a core hole approach, a methodology that has been successful for binary nitride
compounds. It is demonstrated that using the spectra of binary compounds for
optimising the core hole charge ( for cubic TiAlN
and for wurtzite AlGaN), the predicted spectra
evolutions of the ternary alloys agree well with the experiments. The spectral
features are subsequently discussed in terms of the electronic structure and
bonding of the alloys.Comment: 11 pages, 9 figures, 1 tabl
High lichen species richness in Polylepis australis forest: New records from South America and Argentina
The Polylepis australis forests in Central Argentina support a great biodiversity in a relative small area. As a result of this study focusing on the diversity and ecology of the lichen communities of these forests, we present five new species for South America: Rinodina ficta, R. malcolmii, R. obscura, Usnea glabrata, Tetramelas triphragmioides and eight taxa new for Argentina: Calicium abietinum, Erioderma leylandii subsp. leylandii, Leptogium microstictum, Phaeophyscia endococcinodes, Rinodina dolichospora, R. intermedia, Usnea cirrosa and U. flavocardia. Unidentified Usnea species, similar to U. silesiaca, were also characterized and discussed.Fil: Rodriguez, Juan Manuel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto de Investigaciones BiolĂłgicas y TecnolĂłgicas. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas, FĂsicas y Naturales. Instituto de Investigaciones BiolĂłgicas y TecnolĂłgicas; ArgentinaFil: DĂaz Dominguez, RaĂșl Enrique. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto de Investigaciones BiolĂłgicas y TecnolĂłgicas. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas, FĂsicas y Naturales. Instituto de Investigaciones BiolĂłgicas y TecnolĂłgicas; ArgentinaFil: Mayrhofer, Helmut. University of Graz; AustriaFil: Passo, Alfredo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Renison, Daniel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto de Investigaciones BiolĂłgicas y TecnolĂłgicas. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas, FĂsicas y Naturales. Instituto de Investigaciones BiolĂłgicas y TecnolĂłgicas; Argentin
Consulting Project 2018/19: Manufacturing process of superconducting magnets: Analysis of manufacturing chain technologies for market-oriented industries. Report
An international consortium of more than 150 organisations worldwide is studying the feasibility of
future particle collider scenarios to expand our understanding of the inner workings of the Universe.
The core of this Future Circular Collider (FCC) study, hosted by CERN, an international organisation
near Geneva (Switzerland), is a 100 km long circular particle collider infrastructure that extends CERN's
current accelerator complex. As a first step, an intensity frontier electron-positron collider is assumed.
The ultimate goal is to build a proton collider with an energy seven times larger than the Large Hadron
Collider (LHC). Such a machine has to be built with novel superconductive magnet technology. Since
it takes decades for such technology to reach industrial maturity levels, R&D has already started. The
superconducting magnet system is considered the major cost driver for construction of such a proton
collider. A good cost-benefit balance for industrial suppliers is considered an important factor for the
funding of such a project.
Aim
The aim of this investigation was to identify the industrial impact potentials of the key processes
needed for the manufacturing of novel high-field superconducting magnets and to find innovative
additional applications for these technologies outside the particle-accelerator domain. Suppliers
and manufacturing partners of CERN would benefit if the know-how could be used for other markets
and to improve their internal efficiency and competitivity on the world-market. Eventually, being more
cost-effective in the manufacturing and being able to leverage further markets on a long-time scale will
also reduce the cost for each step in the manufacturing chain and ultimately lead to lower costs for the
superconducting magnet system of a future high-energy particle collider.
Method
The project is carried out by means of the Technology Competence Leveraging method, which has
been pioneered by the Vienna University of economics and business in Austria. It aims to find new
application fields for the three most promising technologies required to manufacture novel high-field
superconducting magnets. This is achieved by gathering information from user-communities,
conducting interviews with experts in different industries and brainstorming for new out-of-the-box
ideas. The most valuable application fields were evaluated according to their Benefit Relevance and
Strategic Fit. During the process, 71 interviews with experts have been carried out, through which 38
new application fields were found with credible impacts beyond particle accelerator projects. They
relate to manufacturing "superconducting Rutherford cables" (15), "thermal treatment" (10) and
"vacuum impregnation with novel epoxy" (13).
Superconducting magnet manufacturing technologies for market-oriented industries Report.
Results: A short description of all application fields that were classified as "high potential" can be found here:
Superconducting Rutherford cable
* Aircraft charging: Commercial airplanes only spend around 45 minutes on the ground at a
time to load and unload passengers. For future electric aircraft this time window would be to
small to charge using conventional cables. The superconducting Rutherford cable could charge
an electric plane fast and efficiently.
* Electricity distribution in hybrid-electric aircraft: On a shorter time scale, hybrid-electric
aircraft is an appealing ecological technology with economic advantages. In this case, electricity
for the electric engines is produced by a generator. Cables with high current densities are needed
inside the aircraft to distribute the energy. The superconducting Rutherford cable could be a
candidate for this task.
* Compact and efficient electricity generators: Using the superconducting Rutherford cable,
small and light engines and generators can be constructed. One end-use example is for instance
the generation of electricity using highly-efficient wind turbines.
Thermal treatment: Heat treatment is needed during the production of superconducting magnet coils. In this processing step,
the raw materials are reacted to form the superconductor. This processing step is used for certain lowtemperature
superconductors as well as for certain high-temperature superconductors.
* Scrap metal recycling: Using a large-scale oven with very accurate temperature stabilisation
over long time periods, melting points of different metals can be selected. This leads to more
efficient recycling of scrap metal. It also permits a higher degrees of process automation and
quality management.
* Thermal treatment of aluminium: Thermal treatment of aluminium comprises technologies
like tempering and hardening. The goal of this technique is to change the characteristics of
aluminium and alloys containing aluminium. End-use applications include for instance the
automotive and aerospace industry, where such exact treatment is necessary.
Vacuum impregnation
* Waste treatmnent companies currently face challenges because new legislation require more
leak-tight containers. Novel epoxy resin developed for superconducting magnets in particle
colliders also needs to withstand high radiation levels. Therefore, this technology can be useful
in the process of managing highly-activated radioactive waste
Practical Delegatable Anonymous Credentials From Equivalence Class Signatures
Anonymous credentials systems (ACs) are a powerful cryptographic tool for privacy-preserving applications and provide strong user privacy guarantees for authentication and access control. ACs allow users to prove possession of attributes encoded in a credential without revealing any information beyond them. A delegatable AC (DAC) system is an enhanced AC system that allows the owners of credentials to delegate the obtained credential to other users. This allows to model hierarchies as usually encountered within public-key infrastructures (PKIs). DACs also provide stronger privacy guarantees than traditional AC systems since the identities of issuers and delegators are also hidden. A credential issuer\u27s identity may convey information about a user\u27s identity even when all other information about the user is protected.
We present a novel delegatable anonymous credential scheme that supports attributes, provides anonymity for delegations, allows the delegators to restrict further delegations, and also comes with an efficient construction. In particular, our DAC credentials do not grow with delegations, i.e., are of constant size. Our approach builds on a new primitive that we call structure-preserving signatures on equivalence classes on updatable commitments (SPSEQ-UC). The high-level idea is to use a special signature scheme that can sign vectors of set commitments which can be extended by additional set commitments. Signatures additionally include a user\u27s public key, which can be switched. This allows us to efficiently realize delegation in the DAC. Similar to conventional SPSEQ signatures, the signatures and messages can be publicly randomized and thus allow unlinkable showings in the DAC system. We present further optimizations such as cross-set commitment aggregation that, in combination, enable selective, efficient showings in the DAC without using costly zero-knowledge proofs. We present an efficient instantiation that is proven to be secure in the generic group model and finally demonstrate the practical efficiency of our DAC by presenting performance benchmarks based on an implementation
A highly selective and self-powered gas sensor via organic surface functionalization of p-Si/n-ZnO diodes
Selectivity and low power consumption are major challenges in the development of sophisticated gas sensor devices. A sensor system is presented that unifies selective sensor-gas interactions and energy-harvesting properties, using defined organic-inorganic hybrid materials. Simulations of chemical-binding interactions and the consequent electronic surface modulation give more insight into the complex sensing mechanism of selective gas detection
Integrated Strategy toward Self-Powering and Selectivity Tuning of Semiconductor Gas Sensors
Inorganic conductometric gas sensors struggle to overcome limitations in high power consumption and poor selectivi-ty. Herein, recent advances in developing self-powered gas sensors with tunable selectivity are introduced. Alternative general approaches for powering gas sensors were realized via proper integration of complementary functionalities (namely; powering and sensing) in a singular heterostructure. These solar light driven gas sensors operating at room temperature without applying any additional external powering sources are comparatively discussed. The TYPE-1 gas sensor based on integration of pure inorganic interfaces (e.g. CdS/n-ZnO/p-Si) is capable of delivering a self-sustained sensing response, while it shows a non-selective interaction towards oxidizing and reducing gases. The structural and the optical merits of TYPE-1 sensor are investigated giving more insights into the role of light activation on the modu-lation of the self-powered sensing response. In the TYPE-2 sensor, the selectivity of inorganic materials is tailored through surface functionalization with self-assembled organic monolayers (SAMs). Such hybrid interfaces (e.g. SAMs/ZnO/p-Si) have specific surface interactions with target gases compared to the non-specific oxidation-reduction interactions governing the sensing mechanism of simple inorganic sensors. The theoretical modeling using density functional theory (DFT) has been used to simulate the sensing behavior of inorganic/organic/gas interfaces, revealing that the alignment of organic/gas frontier molecular orbitals with respect to the inorganic Fermi level is the key factor for tuning selectivity. These platforms open new avenues for developing advanced energy-neutral gas sensing devices and concepts
Iron status in women with infertility and controls: a case-control study
BackgroundIron deficiency is a common problem in subfertile women. The influence of iron status on unexplained infertility is unknown.MethodsIn a case-control study, 36 women with unexplained infertility and 36 healthy non-infertile controls were included. Parameters of iron status including serum ferritin and a serum ferritin <30 ”g/dL served as main outcome parameters.ResultsWomen with unexplained infertility demonstrated a lower transferrin saturation (median 17.3%, IQR 12.7-25.2 versus 23.9%, IQR 15.4-31.6; p= 0.034) and a lower mean corpuscular hemoglobin concentration (median 33.6 g/dL, IQR 33.0-34.1 versus 34.1 g/dL, IQR 33.2-34.7; p= 0.012). Despite the fact that there was no statistically significant difference in median ferritin levels (p= 0.570), women with unexplained infertility had ferritin levels <30”g/L more often (33.3%) than controls (11.1%; p= 0.023). In a multivariate model, unexplained infertility and abnormal thyroid antibodies were associated with ferritin <30”g/L (OR 4.906, 95%CI: 1.181-20.388; p= 0.029 and OR 13.099; 2.382-72.044; p= 0.029, respectively).ConclusionFerritin levels <30”g/L were associated with unexplained infertility and might be screened in the future. Further studies with a focus on iron deficiency and iron treatment on women with unexplained infertility are warranted
Stable and Active Oxygen Reduction Catalysts with Reduced Noble Metal Loadings through Potential Triggered Support Passivation
The development of stable, costâefficient and active materials is one of the main challenges in catalysis. The utilization of platinum in the electroreduction of oxygen is a salient example where the development of new material combinations has led to a drastic increase in specific activity compared to bare platinum. These material classes comprise nanostructured thin films, platinum alloys, shapeâcontrolled nanostructures and coreâshell architectures. Excessive platinum substitution, however, leads to structural and catalytic instabilities. Herein, we introduce a catalyst concept that comprises the use of an atomically thin platinum film deposited on a potentialâtriggered passivating support. The model catalyst exhibits an equal specific activity with higher atom utilization compared to bulk platinum. By using potentialâtriggered passivation of titanium carbide, irregularities in the Pt film heal out via the formation of insoluble oxide species at the solid/liquid interface. The adaptation of the described catalyst design to the nanoscale and to highâsurfaceâarea structures highlight the potential for stable, passivating catalyst systems for various electrocatalytic reactions such as the oxygen reduction reaction
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