411,909 research outputs found

    Electromigration in thin tunnel junctions with ferromagnetic/nonmagnetic: nanoconstrictions, local heating, and direct and wind forces

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    Current Induced Resistance Switching (CIS) was recently observed in thin tunnel junctions with ferromagnetic (FM) electrodes \emph{i.e} FM/I/FM. This effect was attributed to electromigration of metallic atoms in nanoconstrictions in the insulating barrier (I). Here we study how the CIS effect is influenced by a thin non-magnetic (NM) Ta layer, deposited just below the AlOx_x insulating barrier in tunnel junctions of the type FM/NM/I/FM (FM=CoFe). Enhanced resistance switching occurs with increasing maximum applied current (\Imax), until a plateau of constant CIS is reached for \Imax\sim65 mA (CIS∌\sim60%) and above. However, such high electrical currents also lead to a large (∌\sim9%) irreversible resistance decrease, indicating barrier degradation. Anomalous voltage-current characteristics with negative derivative were also observed near \pm\Imax and this effect is here attributed to heating in the tunnel junction. One observes that the current direction for which resistance switches in FM/NM/I/FM (clockwise) is opposite to that of FM/I/FM tunnel junctions (anti-clockwise). This effect will be discussed in terms of a competition between the electromigration contributions due to the so called direct and wind forces. It will be shown that the direct force is likely to dominate electromigration in the Ta (NM) layers, while the wind contribution likely dominates in the CoFe (FM) layers

    Interactions of Cisplatin and Daunorubicin at the chromatin level

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    Unexpectedly, the widely used anticancer agents Cisplatin (Cis-Pt) and Daunorubicin (Dauno) exhibited cell type- and concentration-dependent synergy or antagonism in vitro. We attempted to interpret these effects in terms of the changes elicited by the drugs in the chromatin, the target held primarily responsible for the cytotoxicity of both agents. We measured the effect of Cis-Pt on the levels of Dauno in different cell compartments, the effect of Cis-Pt on Dauno-induced nucleosome eviction, and assessed the influence of Dauno on DNA platination in flow- and laser scanning cytometry as well as in laser ablation-inductively coupled plasma-mass spectrometry assays. We show that the two drugs antagonize each other through a decrease of interstrand crosslinks upon co-treatment with Dauno, and also via the diminished Dauno uptake in the presence of Cis-Pt, and both effects are observed already at low Dauno concentrations. At high Dauno concentrations synergy becomes dominant because histone eviction by Dauno intercalation into the DNA is enhanced in the presence of co-treatment with Cis-Pt. These interactions may have an impact on the efficacy of combination treatment protocols, considering the long retention time of DNA adducts formed by both agents

    Rotational spectroscopy and dipole moment of cis-cis HOONO and DOONO

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    The rotational spectrum of cis-cis HOONO has been studied over a broad range of frequencies, 13–840 GHz, using pulsed beam Fourier-transform microwave spectroscopy and room-temperature flow cell submillimeter spectroscopy. The rotational spectrum of the deuterated isotopomer, cis-cis DOONO, has been studied over a subset of this range, 84–640 GHz. Improved spectroscopic constants have been determined for HOONO, and the DOONO spectrum is analyzed for the first time. Weak-field Stark effect measurements in the region of 84–110 GHz have been employed to determine the molecular dipole moments of cis-cis HOONO [”a=0.542(8) D,”b=0.918(15) D,”=1.07(2) D] and DOONO [”a=0.517(9) D,”b=0.930(15) D,”=1.06(2) D]. The quadrupole coupling tensor in the principal inertial axis system for the 14N nucleus has been determined to be chiaa=1.4907(25) MHz,chibb=–4.5990(59) MHz,chiab=3.17(147) MHz, and chicc=3.1082(59) MHz. Coordinates of the H atom in the center-of-mass frame have been determined with use of the Kraitchman equations, |aH|=0.516 Å and |bH|=1.171 Å. The inertial defects of HOONO and DOONO are consistent with a planar equilibrium structure with significant out-of-plane H atom torsional motion. Comparisons of the present results are made to ab initio calculations

    Economic Impact of a Potential Free Trade Agreement (FTA) Between the European Union and the Commonwealth of the Independent States

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    We evaluate the effects of potential measures to liberalize trade between the EU and the CIS using a computable general equilibrium (CGE) model. We look At the CIS as an aggregate and we also present results for individual CIS countries Our CGE model takes different underlying industry specific market structures and elasticities into account. Furthermore, the model incorporates estimated non-tariff trade barriers to trade in services. The results are compared to a baseline chich incorporates recent developments in the trade policy environment, i.e. the phase out of ATC, enlargement of the EU and CIS accessions to the WTO. The analysis takes agricultural liberalization, liberalization in industrial tariffs, and liberalization in services trade as well as trade facilitation measures into account. Chile there is important heterogeneity in the impact of FTAs on individual countries, the results indicate that the CIS as a whole would experience a negative income effect if the FTA would be limited only to trade in goods. This implies that the CIS would most likely to benefit from an FTA with the EU if it would incorporate deeper form of integration not being limited to liberalization of tariffs in goods.CGE, EU-CIS Free Trade Area, Russia, Ukraine, CIS

    Economic Impact of a Potential Free Trade Agreement (FTA) Between the European Union and the Commonwealth of Independent States

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    We evaluate the effects of potential measures to liberalize trade between the EU and the CIS using a computable general equilibrium (CGE) model. We look at the CIS as an aggregate and we also present results for individual CIS countries. Our CGE model takes different underlying industry specific market structures and elasticities into account. Furthermore, the model incorporates estimated non-tariff trade barriers to trade in services. The results are compared to a baseline that incorporates recent developments in the trade policy environment, i.e. the phase out of ATC, enlargement of the EU and CIS accessions to the WTO. The analysis takes agricultural liberalization, liberalization in industrial tariffs, and liberalization in services trade as well as trade facilitation measures into account. While there is important heterogeneity in the impact of FTAs on individual countries, the results indicate that the CIS as a whole would experience a negative income effect if the FTA would be limited only to trade in goods. This is due to strong trade diversion effects. The CIS states have high tariffs, and these would remain against third countries under an FTA. This implies that the CIS would most likely to benefit from an FTA with the EU if it would incorporate deeper forms of integration not being limited to liberalization of tariffs in goods, or if it is accompanied by a general reduction in CIS tariffs against third countries.CGE, EU-CIS Free Trade Area, Russia, Ukraine, CIS

    A note on exchange rate pass-through in CIS countries

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    We assess the extent and speed of exchange rate pass-through in the countries of the Commonwealth of Independent States (CIS). We do this in the framework of vector autoregressive regressions, utilising impulse functions and variance decompositions with monthly data that starts in 1999 in order to avoid periods of very high inflation and the Russian crisis. We find that exchange rate movements have a clear impact on price developments in the CIS countries. The speed of the pass-through is also fairly high: in most cases the full effect is transmitted into domestic prices in less than 12 months. Unlike in many other emerging market economies, an additional effect from US prices on to domestic prices is not significant. The extent of the exchange rate pass-through is usually much higher than in our benchmark group of emerging market countries. Variance decomposition shows that the relative share of exchange rates in explaining changes in domestic prices is higher in the CIS countries than in the benchmark group. Our results indicate that policy-makers in the CIS countries need to pay more attention to exchange rate movements than in many other emerging market countries.exchange rate pass-through; inflation; exchange rate regime; transition countries

    No evidence that FLT3 status should be considered as an indicator for transplantation in acute myeloid leukemia (AML): an analysis of 1135 patients, excluding acute promyelocytic leukemia, from the UK MRC AML 10 and 12 trials

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    Fetal liver tyrosine kinase 3 (FLT3) internal tandem duplications (ITDs) are powerful adverse prognostic indicators for relapse in acute myelold leukemia (AML) but the most efficacious therapy for FLT3/ ITD+ patients is currently unknown. We evaluated outcome according to FLT3/ITD status in 1135 adult patients treated according to United Kingdom Medical Research Council (UK MRC) AML protocols: 141 received an autograft, and 170 received a matched sibling allograft in first complete remission (CR). An FLT3/ITD was detected in 25% of patients and was an independent predictor for relapse (P < .001). It remained prognostic for increased relapse in patients who received a transplant (odds ratio [OR] = 1.91; 95% confidence intervals [CIs] 1.13-3.21; P = .02), with no evidence of a difference in effect between patients who received an autograft (OR = 2.39; CIs = 1.24-4.62) and patients who received an allograft (OR = 1.31; CIs = 0.56-3.06) (test for interaction, P = .3) or between patients who did or did not receive a transplant (P = .4). These results were confirmed in an analysis of 186 patients randomized to receive or not receive an autograft in first CR and in a donor-versus-no donor analysis of 683 patients to assess the role of allograft (for latter, FLT3/ITD- OR = 0.70, CIs = 0.53-0.92; FLT3/ITD+ OR = 0.59, CIs = 0.40-0.87; test for interaction, P = .5). These results suggest that at present there is no strong evidence that FLT3 status should influence the decision to proceed to transplantation

    Whole-genome sequencing to understand the genetic architecture of common gene expression and biomarker phenotypes.

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    Initial results from sequencing studies suggest that there are relatively few low-frequency (&lt;5%) variants associated with large effects on common phenotypes. We performed low-pass whole-genome sequencing in 680 individuals from the InCHIANTI study to test two primary hypotheses: (i) that sequencing would detect single low-frequency-large effect variants that explained similar amounts of phenotypic variance as single common variants, and (ii) that some common variant associations could be explained by low-frequency variants. We tested two sets of disease-related common phenotypes for which we had statistical power to detect large numbers of common variant-common phenotype associations-11 132 cis-gene expression traits in 450 individuals and 93 circulating biomarkers in all 680 individuals. From a total of 11 657 229 high-quality variants of which 6 129 221 and 5 528 008 were common and low frequency (&lt;5%), respectively, low frequency-large effect associations comprised 7% of detectable cis-gene expression traits [89 of 1314 cis-eQTLs at P &lt; 1 × 10(-06) (false discovery rate ∌5%)] and one of eight biomarker associations at P &lt; 8 × 10(-10). Very few (30 of 1232; 2%) common variant associations were fully explained by low-frequency variants. Our data show that whole-genome sequencing can identify low-frequency variants undetected by genotyping based approaches when sample sizes are sufficiently large to detect substantial numbers of common variant associations, and that common variant associations are rarely explained by single low-frequency variants of large effect
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