1,506 research outputs found
High-temperature superconducting fault current microlimiters
High-temperature superconducting microbridges implemented with
YBa(2)Cu(3)O(7-delta) thin-films are shown to be possible fault current
limiters for microelectronic devices with some elements working at temperatures
below the superconducting critical temperature and, simultaneously, under very
low power conditions (below 1W). This is the case in the important applications
of superconductors as SQUID based electronics, and technologies for
communication or infrared detectors. In this paper it is shown that the good
thermal behavior of these microlimiters allows working in a regime where even
relatively small faults induce their transition to highly dissipative states,
dramatically increasing their limitation efficiency. The conditions for optimal
refrigeration and operation of these microlimiters are also proposed.Comment: 10 pages, 3 figures. LaTeX and EPS file
Stand type affects fluxes of volatile organic compounds from the forest floor in hemiboreal and boreal climates
The forest floor is a significant contributor to the stand-scale fluxes of biogenic volatile organic compounds. In this study, the effect of tree species (Scots pine vs. Norway spruce) on forest floor fluxes of volatile organic compounds (VOC) was compared in boreal and hemiboreal climates.Peer reviewe
Renormalized Energies of Superfluorescent Bursts from an Electron-Hole Magneto-plasma with High Gain in InGaAs Quantum Wells
We study light emission properties of a population-inverted 2D electron-hole
plasma in a quantizing magnetic field. We observe a series of superfluorescent
bursts, discrete both in time and energy, corresponding to the cooperative
recombination of electron-hole pairs from different Landau levels. The emission
energies are strongly renormalized due to many-body interactions among the
photogenerated carriers, exhibiting red-shifts as large as 20 meV at 15 T.
However, the magnetic field dependence of the lowest Landau level emission line
remains excitonic at all magnetic fields. Interestingly, our time-resolved
measurements show that this lowest-energy burst occurs only after all upper
states become empty, suggesting that this excitonic stability is related to the
`hidden symmetry' of 2D magneto-excitons expected in the magnetic quantum
limit.Comment: 5 pages, 4 figure
Pre-Erythrocytic Vaccine Candidates in Malaria
A vaccine providing sterile immunity against malaria has been shown to be possible with antigens from the pre-erythrocytic stages of malaria. Therefore, it is reasonable to focus vaccine development efforts on the pre-erythrocytic stages, consisting of both sporozoites and liver stage parasites, where it is expected that sterile immunity against the parasite can be elicited to block the development of blood stage infection, clinical disease, and resulting parasite transmission. Accordingly, we will review the preclinical and clinical studies of malaria pre-erythrocytic efforts as well as highlight the advances, trends, and roadblocks encountered in these efforts
Ein einfaches Verfahren zur Herstellung anellierter Thiophene
A simple method for the synthesis of fused thiophenes by reaction of agr-carboxymethyl substituted cyclic ketones withLawesson-reagent is described. Considerations concerning the reaction mechanism are given
Structural basis for redox regulation of cytoplasmic and chloroplastic triosephosphate isomerases from Arabidopsis thaliana
"In plants triosephosphate isomerase (TPI) interconyerts glyceraldehyde 3-phosphate (G3P) and dihydroxyacetone phosphate (DHAP) during glycolysis, gluconeogenesis, and the Calvin-Benson cycle. The nuclear genome of land plants encodes two tpi genes, one gene product is located in the cytoplasm and the other is imported into the chloroplast. Herein we report the crystal structures of the TPIs from the vascular plant Arabidopsis thaliana (AtTPIs) and address their enzymatic modulation by redox agents. Cytoplasmic TPI (cTPI) and chloroplast TPI (pdTPI) share more than 60% amino acid identity and assemble as (beta-alpha)(8) dimers with high structural homology. cTPI and pdTPI harbor two and one accessible thiol groups per monomer respectively. cTPI and pdTPI present a cysteine at an equivalent structural position (C13 and C15 respectively) and cTPI also contains a specific solvent accessible cysteine at residue 218 (cTPI-C218). Site directed mutagenesis of residues pdTPI-C15, cTPI-C13, and cTPI-C218 to serine substantially decreases enzymatic activity, indicating that the structural integrity of these cysteines is necessary for catalysis. AtTPIs exhibit differential responses to oxidative agents, cTPI is susceptible to oxidative agents such as diamide and H2O2, whereas pdTPI is resistant to inhibition. Incubation of AtTPIs with the sulfhydryl conjugating reagents methylmethane thiosulfonate (MMTS) and glutathione inhibits enzymatic activity. However, the concentration necessary to inhibit pdTPI is at least two orders of magnitude higher than the concentration needed to inhibit cTPI. Western-blot analysis indicates that residues cTPI-C13, cTPI-C218, and pdTPI-C15 conjugate with glutathione. In summary, our data indicate that AtTPIs could be redox regulated by the derivatization of specific AtTPI cysteines (cTPI-C13 and pdTPI-C15 and cTPI-C218). Since AtTPIs have evolved by gene duplication, the higher resistance of pdTPI to redox agents may be an adaptive consequence to the redox environment in the chloroplast.
Relationship between RET fusion partner and treatment outcomes in patients (pts) with non-small cell lung cancer (NSCLC) from the phase I/II ARROW study and real-world data (RWD)
Background: The ARROW study is assessing the anti-tumour activity of pralsetinib, a highly-selective RET inhibitor in advanced solid tumours, including RET fusion+ NSCLC. Prolonged overall survival (OS) was reported with RET inhibitor therapy in NSCLC pts with CCDC6 vs KIF5B RET fusions (Tan AC, et al. JTO 2020). We examined the relationship between RET fusion partner and treatment outcomes in pts with RET fusion+ NSCLC from ARROW and RWD.
Methods: In phase 2 of ARROW, 233 pts with RET fusion+ NSCLC (KIF5B n=164, CCDC6 n=41, Other n=28) received 400mg/day pralsetinib until progression, intolerance or withdrawal. Primary endpoints: overall response rate (ORR) and safety. In Q4 2021, 67 pts with RET fusion+ NSCLC (KIF5B n=46, CCDC6 n=8, Other n=13) met eligibility criteria from the nationwide (US-based) de-identified Flatiron Health-FMI NSCLC clinico-genomic database. Cox regression analyses are reported.
Results: Baseline characteristics by RET fusion partner were balanced across subgroups within ARROW. ORR was similar with KIF5B and CCDC6, but lower with Other RET fusions (Table); the same trend was seen in treatment-naïve and prior treatment subgroups. Disease control rate (DCR) was high in all pts, but lowest in the Other RET fusions subgroup. Median duration of response (DOR) and progression-free survival (PFS) were higher with CCDC6 vs KIF5B RET fusions irrespective of prior treatment. OS data are immature. In the RWD cohort, median OS was numerically longer in CCDC6 and Other RET fusions vs KIF5B RET-driven disease (52.8 and 38.5 vs 19.1 months); when adjusted for covariates including RET inhibitor usage (KIF5B n=12, CCDC6 n=5, Other n=5), OS HRs for CCDC6 and Other RET fusions vs KIF5B were 0.49 (95% CI: 0.08–3.11) and 0.41 (95% CI: 0.13–1.30), respectively.
Conclusions: Pralsetinib is active in RET fusion+ NSCLC, regardless of fusion partner or prior treatment. CCDC6 RET-driven disease may have a better prognosis vs KIF5B
Commissioning of the vacuum system of the KATRIN Main Spectrometer
The KATRIN experiment will probe the neutrino mass by measuring the
beta-electron energy spectrum near the endpoint of tritium beta-decay. An
integral energy analysis will be performed by an electro-static spectrometer
(Main Spectrometer), an ultra-high vacuum vessel with a length of 23.2 m, a
volume of 1240 m^3, and a complex inner electrode system with about 120000
individual parts. The strong magnetic field that guides the beta-electrons is
provided by super-conducting solenoids at both ends of the spectrometer. Its
influence on turbo-molecular pumps and vacuum gauges had to be considered. A
system consisting of 6 turbo-molecular pumps and 3 km of non-evaporable getter
strips has been deployed and was tested during the commissioning of the
spectrometer. In this paper the configuration, the commissioning with bake-out
at 300{\deg}C, and the performance of this system are presented in detail. The
vacuum system has to maintain a pressure in the 10^{-11} mbar range. It is
demonstrated that the performance of the system is already close to these
stringent functional requirements for the KATRIN experiment, which will start
at the end of 2016.Comment: submitted for publication in JINST, 39 pages, 15 figure
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