We report on the first systematic study of spin transport in bilayer graphene (BLG) as a function of mobility, minimum conductivity, charge density and temperature. The spin relaxation time τ s scales inversely with the mobility µ of BLG samples both at room temperature (RT) and at low temperature (LT). This indicates the importance of D'yakonov -Perel' spin scattering in BLG. Spin relaxation times of up to 2 ns at RT are observed in samples with the lowest mobility. These times are an order of magnitude longer than any values previously reported for single layer graphene (SLG). We discuss the role of intrinsic and extrinsic factors that could lead to the dominance of D'yakonov-Perel' spin scattering in BLG. In comparison to SLG, significant changes in the carrier density dependence of τ s are observed as a function of temperature.

We demonstrate injection, transport and detection of spins in spin valve arrays patterned in both copper based chemical vapor deposition (Cu-CVD) synthesized wafer scale single layer (SLG) and bilayer graphene (BLG). We observe spin relaxation times comparable to those reported for exfoliated graphene samples demonstrating that CVD specific structural differences such as nanoripples and grain boundaries do not limit spin transport in the present samples. Our observations make Cu-CVD graphene a promising material of choice for large scale spintronic applications. KEYWORDS Spin transport, Hanle precession, graphene, CVD growth, rippleHigh charge mobility, (1) small spin-orbit coupling, (2) negligible hyperfine interaction, (3) the electric field effect (4) and last but not least the ability to sustain large current densities (5) make graphene an exceptional material for spintronic applications. The demonstration of micrometer long spin relaxation length in exfoliated SLG and BLG even at room temperature (RT) (6)-(12) and spin relaxation times in the order of nanoseconds (11)-(12) may pave the way to realize several of the recently proposed spin based device concepts. (13)- (15) However, for realistic device applications it remains to be seen, if such impressive spin transport properties can also be achieved in wafer scale CVD graphene. Equally important, spin transport studies based on micromechanically exfoliated graphene sheets are often too slow for the quick exploration of the basic spin properties of graphene and for testing potential device architectures. The recent progress in the Cu-based CVD growth of graphene has a strong impact on charge based graphene device applications. (16) However, CVD graphene has a large number of structural differences when compared to exfoliated graphene such as grain boundaries, (17) defects like pentagons, heptagons, octagons, vacancies, 1D line charges (18) and in the case of bilayer graphene possibly interlayer stacking faults. (19)-(20) In addition, the current growth and transfer process introduces residual catalysts, wrinkles, quasi-periodic nanoripple arrays and new classes of organic residues. (19) Despite all of these defects, charge mobilities in CVD graphene field effect transistors (FETs) have been comparable to what has been reported for most exfoliated graphene FETs on Si/SiO 2 substrates. (21) 3 Whether this synthesis route will also play an important role for spin transport studies and large scale spin-based device applications depends on how the same defects affect the spin relaxation times.In this Letter, we demonstrate spin transport in Cu-CVD grown SLG and BLG transferred onto conventional Si/SiO 2 substrates and discuss the role of nano-ripples, a ubiquitous surface structure of Cu-CVD graphene (19) . The growth and transfer of large-scale Cu-CVD graphene are the same as in Ref.(17). By controlling the post-growth annealing time of CVD graphene, we can obtain films with SLG coverage up to 95% or additional BLG coverage up to 40%. The latter...

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We explored a very interesting gold nanoparticle system-pegylated gold in colloidal solution-and analyzed its uptake by mice colorectal adenocarcinoma CT26 tumor cells and the impact on the cell's response to x-ray irradiation. We found that exposure to polyethylene glycol (PEG) modified ('pegylated') 4.7 ± 2.6 nm gold nanoparticles synthesized by a novel synchrotron-based method enhances the response of CT26 cells to x-ray irradiation. Transmission electron microscopy (TEM) and confocal microscopy revealed that substantial amounts of such nanoparticles are taken up and absorbed by the cells and this conclusion is supported by quantitative induced coupled plasma (ICP) results. Standard tests indicated that the internalized particles are highly biocompatible but strongly enhance the cell damage induced by x-ray irradiation. Synchrotron radiation Fourier transform infrared (SR-FTIR) spectromicroscopy analyzed the chemical aspects of this phenomenon: the appearance of C = O stretching bond spectral features could be used as a marker for cell damage and confirmed the enhancement of the radiation-induced toxicity for cells.

). An appropriate level of approximation subsignal was systematically specified as a threshold for cluster identification, based on multiresolution analysis (MRA) of wavelet transformation. By the established threshold, the dynamic properties of clusters including the appearance time fraction of clusters F cl , average cluster duration time s cl , cluster frequency f cl , and local average solids holdup in clusters e sc , at different radial and axial positions were determined under the turbulent, transition and fast fluidization flow regimes. The results also describe the dynamic properties of clusters and flow patterns in the splash zone along with the dense bottom region of the circulating fluidized beds.

Quantum computing technology is maturing at a relentless pace, yet individual quantum bits are wired one by one. As quantum processors become more complex, they require efficient interfaces to deliver signals for control and readout while keeping the number of inputs manageable. Digital electronics offers solutions to the scaling challenge by leveraging established industrial infrastructure and applying it to integrate silicon-based quantum devices with conventional CMOS circuits. Here, we combine both technologies at milikelvin temperatures and demonstrate the building blocks of a dynamic random access architecture for efficient readout of complex quantum circuits. Our circuit is divided into cells, each containing a CMOS quantum dot (QD) and a field-effect transistor that enables selective readout of the QD, as well as charge storage on the QD gate similar to 1T-1C DRAM technology. We show dynamic readout of two cells by interfacing them with a single radiofrequency resonator. Our results demonstrate a path to reducing the number of input lines per qubit and enable addressing of large-scale device arrays. * simon.schaal.15@ucl.ac.uk

Regulatory B cells (Bregs) are a B cell subset that plays a suppressive role in immune responses. The CD19 + CD1d hi CD5 + Bregs that can execute regulatory functions via secreting IL-10 are defined as B10 cells. Bregs suppress autoimmune and inflammatory diseases, whereas they exacerbate infectious diseases caused by bacteria, viruses, or parasites. Notably, the molecular mechanisms regulating the development and functions of Bregs are still largely unknown. Furthermore, the biological impact of Bregs in fungal infection has not yet been demonstrated. Here, we compared the gene expression profiles of IL-10-producing and –non-producing mouse splenic B cells stimulated with lipopolysaccharide (LPS) or anti-CD40 antibody. Blimp-1, a transcription factor known to be critical for plasma cell differentiation, was found to be enriched in the IL-10-producing B cells. The frequency of Blimp-1 + B10 cells was increased in LPS-treated mice and in isolated B10 cells that were stimulated with LPS. Surprisingly, B cell-specific Blimp-1 knockout (Cko) mice, generated by CD19 promoter driven Cre recombinase-dependent deletion of Prdm1 (gene encoding Blimp-1), showed higher frequencies of B10 cells both in the steady state and following injection with LPS, as compared with control littermates. However, B10 cells lacking Blimp-1 failed to efficiently suppress the proliferation of naïve CD4 + T cells primed with anti-CD3 and anti-CD28 antibodies. B10 cells can be stimulated for further differentiation into plasmablasts, and a subset of plasmablasts express IL-10. We found that B10 cells from Cko mice failed to generate both IL-10-non-producing and IL-10-producing plasmablasts. Mechanistically, we found that Blimp-1 can directly suppress Il-10 , whereas, in the presence of activated STAT3, Blimp-1 works together with activated STAT3 to upregulate Il-10 . Moreover, we also found that B10 cells improve the clearance of Candida albicans infection but worsen the infection mortality. Notably, a lack of Blimp-1 in B10 cells did not change these effects of adoptively transferred B10 cells on fungal infections. Together, our data show that Blimp-1 regulates the generation, differentiation, and IL-10 production of Bregs.

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