On converse bounds for classical communication over quantum channels

We explore several new converse bounds for classical communication over quantum channels in both the one-shot and asymptotic regimes. First, we show that the Matthews-Wehner meta-converse bound for entanglement-assisted classical communication can be achieved by activated, no-signalling assisted codes, suitably generalizing a result for classical channels. Second, we derive a new efficiently computable meta-converse on the amount of classical information unassisted codes can transmit over a single use of a quantum channel. As applications, we provide a finite resource analysis of classical communication over quantum erasure channels, including the second-order and moderate deviation asymptotics. Third, we explore the asymptotic analogue of our new meta-converse, the $\Upsilon$-information of the channel. We show that its regularization is an upper bound on the classical capacity, which is generally tighter than the entanglement-assisted capacity and other known efficiently computable strong converse bounds. For covariant channels we show that the $\Upsilon$-information is a strong converse bound.Comment: v3: published version; v2: 18 pages, presentation and results improve

Light Sheet Microscopy for Tracking Single Molecules on the Apical Surface of Living Cells

Single particle tracking is a powerful tool to study single molecule dynamics in living biological samples. However, current tracking techniques, which are based mainly on epifluorescence, confocal, or TIRF microscopy, have difficulties in tracking single molecules on the apical surface of a cell. We present here a three-dimensional (3D) single particle tracking technique that is based on prism coupled light-sheet microscopy (PCLSM). This novel design provides a signal-to-noise ratio comparable to confocal microscopy while it has the capability of illuminating at arbitrary depth. We demonstrate tracking of single EGF molcules on the apical surface of live cell membranes from their binding to EGF receptors until they are internalized or photobleached. We found that EGF exhibits multiple diffusion behaviors on live A549 cell membranes. At room temperature, the average diffusion coefficient of EGF on A549 cells was measured to be 0.13 μm²/s. Depletion of cellular cholesterol with methyl-β-cyclodextrin leads to a broader distribution of diffusion coefficients and an increase of the average diffusion coefficient at room temperature. This light-sheet based 3D single particle tracking technique solves the technique difficulty of tracking single particles on apical membranes and is able to document the whole “lifetime” of a particle from binding till photobleaching or internalization

Light Sheet Microscopy for Tracking Single Molecules on the Apical Surface of Living Cells

Single particle tracking is a powerful tool to study single molecule dynamics in living biological samples. However, current tracking techniques, which are based mainly on epifluorescence, confocal, or TIRF microscopy, have difficulties in tracking single molecules on the apical surface of a cell. We present here a three-dimensional (3D) single particle tracking technique that is based on prism coupled light-sheet microscopy (PCLSM). This novel design provides a signal-to-noise ratio comparable to confocal microscopy while it has the capability of illuminating at arbitrary depth. We demonstrate tracking of single EGF molcules on the apical surface of live cell membranes from their binding to EGF receptors until they are internalized or photobleached. We found that EGF exhibits multiple diffusion behaviors on live A549 cell membranes. At room temperature, the average diffusion coefficient of EGF on A549 cells was measured to be 0.13 μm²/s. Depletion of cellular cholesterol with methyl-β-cyclodextrin leads to a broader distribution of diffusion coefficients and an increase of the average diffusion coefficient at room temperature. This light-sheet based 3D single particle tracking technique solves the technique difficulty of tracking single particles on apical membranes and is able to document the whole “lifetime” of a particle from binding till photobleaching or internalization

Forest plots of OS associated with bFGF expression in lung cancer.

<p>Forest plots of OS associated with bFGF expression in lung cancer.</p

“Fastening” Porphyrin in Highly Cross-Linked Polyphosphazene Hybrid Nanoparticles: Powerful Red Fluorescent Probe for Detecting Mercury Ion

It is a significant issue to overcome the concentration-quenching effect of the small fluorescent probes and maintain the high fluorescent efficiency at high concentration for sensitive and selective fluorescent mark or detection. We developed a new strategy to “isolate” and “fasten” porphyrin moieties in a highly cross-linked poly­(tetraphenylporphyrin-<i>co</i>-cyclotriphosphazene) (TPP–PZS) by the polycondensation of hexachlorocyclotriphosphazene (HCCP) and 5,10,15,20-tetrakis­(4-hydroxyphenyl)­porphyrin (TPP-(OH)₄) in a suitable solvent. The resulting TPP–PZS particles were characterized with transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared (FTIR), ³¹P nuclear magnetic resonance (NMR), and ultraviolet and visible (UV–vis) absorption spectra. Remarkably, TPP–PZS particles obtained in acetone emitted a bright red fluorescence both in powder state and in solution because the aggregation of porphyrin moieties in “H-type” (face-to-face) and “J-type” (edge-to-edge) was effectively blocked. The fluorescent TPP–PZS particles also showed superior resistance to photobleaching, and had a high sensitivity and selectivity for the detection of Hg²⁺ ions. The TPP–PZS particles were therefore used as an ideal material for preparing test strips to quickly detect/monitor the Hg²⁺ ions in a facile way

Results of quality assessments according to ELCWP criteria.

<p>Score distributions are expressed by the mean values. IHC, immunohistochemistry; ELISA, enzyme linked immunosorbent assay; NSCLC, non-small cell lung cancer; SCLC, small cell lung cancer; Significant, significant prognostic factor for survival (P<0.05); Non-significant, not significant prognostic factor for survival (P>0.05).</p

Forest plots of OS assessing bFGF expression in retrospective studies and prospective studies.

<p>Forest plots of OS assessing bFGF expression in retrospective studies and prospective studies.</p

Forest plots of OS assessing bFGF expression in non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC).

<p>Forest plots of OS assessing bFGF expression in non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC).</p

Sensitivity analysis for combined HRs evaluating bFGF expression on OS.

<p>Sensitivity analysis for combined HRs evaluating bFGF expression on OS.</p

His26 Protonation in Cytochrome c Triggers Microsecond β‑Sheet Formation and Heme Exposure: Implications for Apoptosis

Cytochrome c unfolds locally and reversibly upon heating at pH 3. UV resonance Raman (UVRR) spectra reveal that instead of producing unordered structure, unfolding converts turns and some helical elements to β-sheet. It also disrupts the Met80–heme bond, and has been previously shown to induce peroxidase activity. Aromatic residues that are H-bonded to a heme propionate (Trp59 and Tyr48) alter their orientation, indicating heme displacement. T-jump/UVRR measurements give time constants of 0.2, 3.9, and 67 μs for successive phases of β-sheet formation and concomitant reorientation of Trp59. UVRR spectra reveal protonation of histidines, and specifically of His26, whose H-bond to Pro44 anchors the 40s Ω loop; this loop is known to be the least stable ‘foldon’ in the protein. His26 protonation is proposed to disrupt its H-bond with Pro44, triggering the extension of a short β-sheet segment at the ‘neck’ of the 40s Ω loop into the loop itself and back into the 60s and 70s helices. The secondary structure change displaces the heme via H-bonds from residues in the growing β-sheet, thereby exposing it to exogenous ligands, and inducing peroxidase activity. This unfolding mechanism may play a role in cardiolipin peroxidation by cyt c during apoptosis