Large Extra Dimension effects through Light-by-Light Scattering at the CERN LHC

Observing light-by-light scattering at the Large Hadron Collider (LHC) has received quite some attention and it is believed to be a clean and sensitive channel to possible new physics. In this paper, we study the diphoton production at the LHC via the process $\rm pp\rightarrow p\gamma\gamma p\rightarrow p\gamma\gamma p$ through graviton exchange in the Large Extra Dimension (LED) model. Typically, when we do the background analysis, we also study the Double Pomeron Exchange (DPE) of $\gamma\gamma$ production. We compare its production in the quark-quark collision mode to the gluon-gluon collision mode and find that contributions from the gluon-gluon collision mode are comparable to the quark-quark one. Our result shows, for extra dimension $\delta=4$, with an integrated luminosity $\rm {\cal L} = 200 fb^{-1}$ at the 14 TeV LHC, that diphoton production through graviton exchange can probe the LED effects up to the scale $\rm M_S=5.06 (4.51, 5.11) TeV$ for the forward detector acceptance $\xi_1 (\xi_2, \xi_3)$, respectively, where $0.0015<\xi_1<0.5$, $0.1<\xi_2<0.5$ and $0.0015<\xi_3<0.15$.Comment: 25 pages. 7 figs. Change some grammatical error

Superconductivity in iron telluride thin films under tensile stress

By realizing in thin films a tensile stress state, superconductivity of 13 K was introduced into FeTe, an non-superconducting parent compound of the iron pnictides and chalcogenides, with transition temperature higher than that of its superconducting isostructural counterpart FeSe. For these tensile stressed films, the superconductivity is accompanied by the softening of the first-order magnetic and structural phase transition; and also, the in-plane extension and out-of-plane contraction are universal in all FeTe films independent of sign of lattice mismatch, either positive or negative. Moreover, the correlations were found exist between the transition temperatures and the tetrahedra bond angles in these thin films.Comment: 4 pages, 4 figures, accepted by Physical Review Letter

Optogenetics and deep brain stimulation neurotechnologies

Brain neural network is composed of densely packed, intricately wired neurons whose activity patterns ultimately give rise to every behavior, thought, or emotion that we experience. Over the past decade, a novel neurotechnique, optogenetics that combines light and genetic methods to control or monitor neural activity patterns, has proven to be revolutionary in understanding the functional role of specific neural circuits. We here briefly describe recent advance in optogenetics and compare optogenetics with deep brain stimulation technology that holds the promise for treating many neurological and psychiatric disorders

V_H replacement in rearranged immunoglobulin genes

Examples suggesting that all or part of the V&lt;sub&gt;H&lt;/sub&gt; segment of a rearranged V&lt;sub&gt;H&lt;/sub&gt;DJ&lt;sub&gt;H&lt;/sub&gt; may be replaced by all or part of another V&lt;sub&gt;H&lt;/sub&gt; have been appearing since the 1980s. Evidence has been presented of two rather different types of replacement. One of these has gained acceptance and has now been clearly demonstrated to occur. The other, proposed more recently, has not yet gained general acceptance because the same effect can be produced by polymerase chain reaction artefact. We review both types of replacement including a critical examination of evidence for the latter. The first type involves RAG proteins and recombination signal sequences (RSS) and occurs in immature B cells. The second was also thought to be brought about by RAG proteins and RSS. However, it has been reported in hypermutating cells which are not thought to express RAG proteins but in which activation-induced cytidine deaminase (AID) has recently been shown to initiate homologous recombination. Re-examination of the published sequences reveals AID target sites in V&lt;sub&gt;H&lt;/sub&gt;-V&lt;sub&gt;H&lt;/sub&gt; junction regions and examples that resemble gene conversion

Threshold-voltage instability of polymer thin-film transistor under gate-bias and drain-bias stresses

Polymer thin-film transistors (PTFTs) based on MEH-PPV semiconductor are fabricated by spin-coating process and characterized. Gate-bias and drain-bias stress effects at room temperature are observed in the devices. The saturation current decreases and the threshold voltage shifts toward negative direction upon the gate-bias stress. However, the saturation current increases and the threshold voltage shifts toward positive direction upon the drain-bias stress. For variable bias stress conditions, carrier mobility is almost unchanged. The results suggest that the origin of threshold-voltage shift upon negative gate-bias stress is predominantly associated with holes trapped within the SiO 2 gate dielectric or at the SiO 2/Si interface due to hotcarrier emission under high gate-bias stress, while time-dependent charge trapping into the deep trap states in the channel region is responsible for the drain-bias stress effect in the PTFTs. © 2008 IEEE.published_or_final_versio

Use of archival versus newly collected tumor samples for assessing PD-L1 expression and overall survival : an updated analysis of KEYNOTE-010 trial

Background: In KEYNOTE-010, pembrolizumab versus docetaxel improved overall survival (OS) in patients with programmed death-1 protein (PD)-L1-positive advanced non-small-cell lung cancer (NSCLC). A prespecified exploratory analysis compared outcomes in patients based on PD-L1 expression in archival versus newly collected tumor samples using recently updated survival data. Patients and methods: PD-L1 was assessed centrally by immunohistochemistry (22C3 antibody) in archival or newly collected tumor samples. Patients received pembrolizumab 2 or 10 mg/kg Q3W or docetaxel 75 mg/m2 Q3W for 24 months or until progression/intolerable toxicity/other reason. Response was assessed by RECIST v1.1 every 9 weeks, survival every 2 months. Primary end points were OS and progression-free survival (PFS) in tumor proportion score (TPS) 50% and 1%; pembrolizumab doses were pooled in this analysis. Results: At date cut-off of 24 March 2017, median follow-up was 31 months (range 23-41) representing 18 additional months of follow-up from the primary analysis. Pembrolizumab versus docetaxel continued to improve OS in patients with previously treated, PD-L1-expressing advanced NSCLC; hazard ratio (HR) was 0.66 [95% confidence interval (CI): 0.57, 0.77]. Of 1033 patients analyzed, 455(44%) were enrolled based on archival samples and 578 (56%) on newly collected tumor samples. Approximately 40% of archival samples and 45% of newly collected tumor samples were PD-L1 TPS 50%. For TPS 50%, the OS HRs were 0.64 (95% CI: 0.45, 0.91) and 0.40 (95% CI: 0.28, 0.56) for archival and newly collected samples, respectively. In patients with TPS 1%, OS HRs were 0.74 (95% CI: 0.59, 0.93) and 0.59 (95% CI: 0.48, 0.73) for archival and newly collected samples, respectively. In TPS 50%, PFS HRs were similar across archival [0.63 (95% CI: 0.45, 0.89)] and newly collected samples [0.53 (95% CI: 0.38, 0.72)]. In patients with TPS 1%, PFS HRs were similar across archival [0.82 (95% CI: 0.66, 1.02)] and newly collected samples [0.83 (95% CI: 0.68, 1.02)]. Conclusion: Pembrolizumab continued to improve OS over docetaxel in intention to treat population and in subsets of patients with newly collected and archival samples

Regulation of caspase-3 processing by cIAP2 controls the switch between pro-inflammatory activation and cell death in microglia.

Cell Death and Disease is an open-access journal published by Nature Publishing Group. This work is licensed under a Creative Commons Attribution 4.0 International Licence. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons licence, users will need to obtain permission from the licence holder to reproduce the material.The activation of microglia, resident immune cells of the central nervous system, and inflammation-mediated neurotoxicity are typical features of neurodegenerative diseases, for example, Alzheimer's and Parkinson's diseases. An unexpected role of caspase-3, commonly known to have executioner role for apoptosis, was uncovered in the microglia activation process. A central question emerging from this finding is what prevents caspase-3 during the microglia activation from killing those cells? Caspase-3 activation occurs as a two-step process, where the zymogen is first cleaved by upstream caspases, such as caspase-8, to form intermediate, yet still active, p19/p12 complex; thereafter, autocatalytic processing generates the fully mature p17/p12 form of the enzyme. Here, we show that the induction of cellular inhibitor of apoptosis protein 2 (cIAP2) expression upon microglia activation prevents the conversion of caspase-3 p19 subunit to p17 subunit and is responsible for restraining caspase-3 in terms of activity and subcellular localization. We demonstrate that counteracting the repressive effect of cIAP2 on caspase-3 activation, using small interfering RNA targeting cIAP2 or a SMAC mimetic such as the BV6 compound, reduced the pro-inflammatory activation of microglia cells and promoted their death. We propose that the different caspase-3 functions in microglia, and potentially other cell types, reside in the active caspase-3 complexes formed. These results also could indicate cIAP2 as a possible therapeutic target to modulate microglia pro-inflammatory activation and associated neurotoxicity observed in neurodegenerative disorders

Discovery of the progenitor of the type Ia supernova 2007on

Type Ia supernovae are exploding stars that are used to measure the accelerated expansion of the Universe and are responsible for most of the iron ever produced. Although there is general agreement that the exploding star is a white dwarf in a binary system, the exact configuration and trigger of the explosion is unclear, which could hamper their use for precision cosmology. Two families of progenitor models have been proposed. In the first, a white dwarf accretes material from a companion until it exceeds the Chandrasekhar mass, collapses and explodes. Alternatively, two white dwarfs merge, again causing catastrophic collapse and an explosion. It has hitherto been impossible to determine if either model is correct. Here we report the discovery of an object in pre-supernova archival X-ray images at the position of the recent type Ia supernova (2007on) in the elliptical galaxy NGC 1404. Deep optical images (also archival) show no sign of this object. From this we conclude that the X-ray source is the progenitor of the supernova, which favours the accretion model for this supernova, although the host galaxy is older (6-9 Gyr) than the age at which the explosions are predicted in the accreting models.Comment: Published in Nature See also the two follow-up papers: Roelofs, Bassa, Voss, Nelemans Nelemans, Voss, Roelofs, Bassa both on astro-ph 02/15/0

One Loop Renormalization of the Littlest Higgs Model

In Little Higgs models a collective symmetry prevents the Higgs from acquiring a quadratically divergent mass at one loop. This collective symmetry is broken by weakly gauged interactions. Terms, like Yukawa couplings, that display collective symmetry in the bare Lagrangian are generically renormalized into a sum of terms that do not respect the collective symmetry except possibly at one renormalization point where the couplings are related so that the symmetry is restored. We study here the one loop renormalization of a prototypical example, the Littlest Higgs Model. Some features of the renormalization of this model are novel, unfamiliar form similar chiral Lagrangian studies.Comment: 23 pages, 17 eps figure