Experimental realization of a universal set of quantum logic gates is the central requirement for the implementation of a quantum computer. In an 'all-geometric' approach to quantum computation, the ...quantum gates are implemented using Berry phases and their non-Abelian extensions, holonomies, from geometric transformation of quantum states in the Hilbert space. Apart from its fundamental interest and rich mathematical structure, the geometric approach has some built-in noise-resilience features. On the experimental side, geometric phases and holonomies have been observed in thermal ensembles of liquid molecules using nuclear magnetic resonance; however, such systems are known to be non-scalable for the purposes of quantum computing. There are proposals to implement geometric quantum computation in scalable experimental platforms such as trapped ions, superconducting quantum bits and quantum dots, and a recent experiment has realized geometric single-bit gates in a superconducting system. Here we report the experimental realization of a universal set of geometric quantum gates using the solid-state spins of diamond nitrogen-vacancy centres. These diamond defects provide a scalable experimental platform with the potential for room-temperature quantum computing, which has attracted strong interest in recent years. Our experiment shows that all-geometric and potentially robust quantum computation can be realized with solid-state spin quantum bits, making use of recent advances in the coherent control of this system.
As a part of a research program aiming to mobilize marine gas hydrate deposits as an energy resource, the worlds' first gas production attempt was performed in early 2013 in the Daini Atsumi Knoll, ...Eastern Nankai Trough, off Honshu Island, Japan. The test concluded with 119 000 m
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(under ambient conditions) of methane gas production during six consecutive days of depressurization operation through a borehole drilled at 1000 m water depth. As thermal and mass transportation in a heterogeneous geological formation are the governing factors of efficiency and effectiveness of the resource, the test was associated with intensive underground temperature monitoring. Temperature sensors installed in one production and two observation boreholes could detect temperature variations during gas production due to the endothermic gas hydrate dissociation process and mass/heat transport around the boreholes. The measurements in the observation holes started one year before the test and continued until plug-and-abandonment, and thus enabled monitoring of both the initial temperature and temperature change arizing from recovery processes. The depth profiles of measured temperatures in all holes can be related to the geological features of the corresponding formation, and those thermal responses revealed the intervals where gas hydrate dissociation predominantly occurred. By analyzing the energy conservation in the production borehole, the gas and water production profiles could be estimated and major gas and water production zones were identified. Preliminary numerical analysis results show the range of formation permeability and that the observed temperature drop is equivalent to the heat consumption by hydrate dissociation for the volume of produced methane gas. Moreover, the thermal responses could provide some clues about the location and mechanism of the sand production event. This sand production event ultimately terminated the production operations on the seventh day of flow.
As a part of a research program aiming to mobilize marine gas hydrate deposits as an energy resource, the worlds' first gas production attempt was performed in early 2013 in the Daini Atsumi Knoll, Eastern Nankai Trough, off Honshu Island, Japan.
Cancer associated fibroblasts (CAFs) are key stroma cells that play dominant roles in tumor progression. However, the CAFs-derived molecular determinants that regulate colorectal cancer (CRC) ...metastasis and chemoresistance have not been fully characterized.
CAFs and NFs were obtained from fresh CRC and adjacent normal tissues. Exosomes were isolated from conditioned medium and serum of CRC patients using ultracentrifugation method and ExoQuick Exosome Precipitation Solution kit, and characterized by transmission electronic microscopy, nanosight and western blot. MicroRNA microarray was employed to identify differentially expressed miRNAs in exosomes secreted by CAFs or NFs. The internalization of exosomes, transfer of miR-92a-3p was observed by immunofluorescence. Boyden chamber migration and invasion, cell counting kit-8, flow cytometry, plate colony formation, sphere formation assays, tail vein injection and primary colon cancer liver metastasis assays were employed to explore the effect of NFs, CAFs and exosomes secreted by them on epithelial-mesenchymal transition, stemness, metastasis and chemotherapy resistance of CRC. Luciferase report assay, real-time qPCR, western blot, immunofluorescence, and immunohistochemistry staining were employed to explore the regulation of CRC metastasis and chemotherapy resistance by miR-92a-3p, FBXW7 and MOAP1.
CAFs promote the stemness, epithelial-mesenchymal transition (EMT), metastasis and chemotherapy resistance of CRC cells. Importantly, CAFs exert their roles by directly transferring exosomes to CRC cells, leading to a significant increase of miR-92a-3p level in CRC cells. Mechanically, increased expression of miR-92a-3p activates Wnt/β-catenin pathway and inhibits mitochondrial apoptosis by directly inhibiting FBXW7 and MOAP1, contributing to cell stemness, EMT, metastasis and 5-FU/L-OHP resistance in CRC. Clinically, miR-92a-3p expression is significantly increased in CRC tissues and negatively correlated with the levels of FBXW7 and MOAP1 in CRC specimens, and high expression of exosomal miR-92a-3p in serum was highly linked with metastasis and chemotherapy resistance in CRC patients.
CAFs secreted exosomes promote metastasis and chemotherapy resistance of CRC. Inhibiting exosomal miR-92a-3p provides an alternative modality for the prediction and treatment of metastasis and chemotherapy resistance in CRC.
We present a table of redshifts for 2907 galaxies and stars in the 145 arcmin super(2) HST ACS GOODS-North, making this the most spectroscopically complete redshift sample obtained to date in a field ...of this size. We also include the redshifts, where available, in a table containing just under 7000 galaxies from the ACS area with image measured from a deep image image obtained with WIRCam on the CFHT, as well as in a table containing 1016 sources with NUVimage and 478 sources with FUVimage (there is considerable overlap) measured from the deep GALEX images in the ACS area. Finally, we include the redshifts, where available, in a table containing the 1199 24 mum sources to 80 muJy measured from the wider area Spitzer GOODS-North. The redshift identifications are greater than 90% complete to magnitudes of image, and image, and to 24 mum fluxes of 250 muJy. An extensive analysis of these data appear in a companion paper, but here we test the efficiency of color-selection techniques to identify populations of high-redshift galaxies and active galactic nuclei. We also examine the feasibility of doing tomography of the intergalactic medium with a 30 m telescope.
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