833 research outputs found
Enhancing quantum entanglement for continuous variables by a coherent superposition of photon subtraction and addition
We investigate how the entanglement properties of a two-mode state can be
improved by performing a coherent superposition operation of photon subtraction
and addition, proposed by Lee and Nha [Phys. Rev. A 82, 053812 (2010)], on each
mode. We show that the degree of entanglement, the EPR-type correlation, and
the performance of quantum teleportation can be all enhanced for the output
state when the coherent operation is applied to a two-mode squeezed state. The
effects of the coherent operation are more prominent than those of the mere
photon subtraction and the addition particularly in the small squeezing regime,
whereas the optimal operation becomes the photon subtraction in the
large-squeezing regime.Comment: 6 pages, 6 figures, published versio
Quantum linear amplifier enhanced by photon subtraction and addition
A deterministic quantum amplifier inevitably adds noise to an amplified
signal due to the uncertainty principle in quantum physics. We here investigate
how a quantum-noise-limited amplifier can be improved by additionally employing
the photon subtraction, the photon addition, and a coherent superposition of
the two, thereby making a probabilistic, heralded, quantum amplifier. We show
that these operations can enhance the performance in amplifying a coherent
state in terms of intensity gain, fidelity, and phase uncertainty. In
particular, the photon subtraction turns out to be optimal for the fidelity and
the phase concentration among these elementary operations, while the photon
addition also provides a significant reduction in the phase uncertainty with
the largest gain effect.Comment: published version, 7 pages, 9 figure
Pleural Effusion in a Peritoneal Dialysis Patient
A 34-year-old female presented with end-stage renal disease (ESRD) treated by peritoneal dialysis (CAPD) complained of a dry cough. Chest X-ray and chest computed tomography (CT) scan revealed massive right hydrothorax. Because the glucose concentration of pleural fluid was markedly high compared with that of serum, we performed isotope and contrast peritoneography. We used CT for localizing it. MRI was also trying to show transdiaphragmatic leakage in peritoneoflural fistula. Temporary discontinuation of CAPD, tetracycline instillation into the pleural space and surgical patch grafting of the diaphragmatic leak have all been described. A novel method may be video-assisted talc pleurodesis
Inhibition of poly(ADP-ribose)polymerase binding to DNA by thymidine dimer
AbstractThe ability of poly(ADP-ribose)polymerase to bind damaged DNA was assessed by electrophoretic mobility shift assay. DNA binding domain of poly(ADP-ribose)polymerase (PARPDBD) binds to synthetic deoxyribonucleotide duplex 10-mer. However, the synthetic deoxyribonucleotide duplex containing cys-syn thymidine dimer which produces the unwinding of DNA helix structure lost its affinity to PARPDBD. It was shown that the binding of PARPDBD to the synthetic deoxyribonucleotide duplex was not affected by O6-Me-dG which causes only minor distortion of DNA helix structure. This study suggests that the stabilized DNA helix structure is important for poly(ADP-ribose)polymerase binding to DNA breaks, which are known to stimulate catalytic activity of poly(ADP-ribose)polymerase
Real-time bladder volume monitoring by the application of a new implantable bladder volume sensor for a small animal model
AbstractAlthough real-time monitoring of bladder volume together with intravesical pressure can provide more information for understanding the functional changes of the urinary bladder, it still entails difficulties in the accurate prediction of real-time bladder volume in urodynamic studies with small animal models. We studied a new implantable bladder volume monitoring device with eight rats. During cystometry, microelectrodes prepared by the microelectromechanical systems process were placed symmetrically on both lateral walls of the bladder, and the expanded bladder volume was calculated. Immunohistological study was done after 1 week and after 4 weeks to evaluate the biocompatibility of the microelectrode. From the point that infused saline volume into the bladder was higher than 0.6mL, estimated bladder volume was statistically correlated with the volume of saline injected (p<0.01). Additionally, the microelectromechanical system microelectrodes used in this study showed reliable biocompatibility. Therefore, the device can be used to evaluate changes in bladder volume in studies with small animals, and it may help to provide more information about functional changes in the bladder in laboratory studies. Furthermore, owing to its biocompatibility, the device could be chronically implanted in conscious ambulating animals, thus allowing a novel longitudinal study to be performed for a specific purpose
Titanium Plate Fixation for a Dehisced Sternum Following Coronary Artery Bypass Grafting: A Case Report
Sternal dehiscence is one of the most troublesome complications following cardiac surgery. Treatment failure and consequent lethal results are very common, even with all the efforts to resolve sternal dehiscence such as removal of infectious tissue, muscle flap interposition, and sternal rewiring. We report on a case of sternal osteomyelitis following coronary artery bypass grafting that was successfully treated with wide sternal resection, titanium plate fixation, and pectoralis muscle flap interposition
Matrix rigidity regulates spatiotemporal dynamics of Cdc42 activity and vacuole formation kinetics of endothelial colony forming cells
Recent evidence has shown that endothelial colony forming cells (ECFCs) may serve as a cell therapy for improving blood vessel formation in subjects with vascular injury, largely due to their robust vasculogenic potential. The Rho family GTPase Cdc42 is known to play a primary role in this vasculogenesis process, but little is known about how extracellular matrix (ECM) rigidity affects Cdc42 activity during the process. In this study, we addressed two questions: Does matrix rigidity affect Cdc42 activity in ECFC undergoing early vacuole formation? How is the spatiotemporal activation of Cdc42 related to ECFC vacuole formation? A fluorescence resonance energy transfer (FRET)-based Cdc42 biosensor was used to examine the effects of the rigidity of three-dimensional (3D) collagen matrices on spatiotemporal activity of Cdc42 in ECFCs. Collagen matrix stiffness was modulated by varying the collagen concentration and therefore fibril density. The results showed that soft (150 Pa) matrices induced an increased level of Cdc42 activity compared to stiff (1 kPa) matrices. Time-course imaging and colocalization analysis of Cdc42 activity and vacuole formation revealed that Cdc42 activity was colocalized to the periphery of cytoplasmic vacuoles. Moreover, soft matrices generated faster and larger vacuoles than stiff matrices. The matrix-driven vacuole formation was enhanced by a constitutively active Cdc42 mutant, but significantly inhibited by a dominant-negative Cdc42 mutant. Collectively, the results suggest that matrix rigidity is a strong regulator of Cdc42 activity and vacuole formation kinetics, and that enhanced activity of Cdc42 is an important step in early vacuole formation in ECFCs
Perirenal Fluid Collection after Kidney Transplantation
A 30-year-old male presented with pitting edema. He had received a kidney transplantation 3 months previously. His serum creatinine level was increased, and a renal ultrasound showed hypoechoic fluid collection in the perirenal space and pelvic cavity. We conducted sono-guided percutaneous drainage of the fluid collected in the pelvic cavity. The chemistry of the peritoneal fluid was more equivalent to serum chemistry values than to urinary values. Simple aspiration and treatment with antibiotics were performed. We have presented a case of lymphocele after kidney transplantation. This case suggests that physicians should remember how to differentiate the pelvic cavity fluid collection in patients who have received a kidney transplant
Curcumin induces stabilization of Nrf2 protein through Keap1 cysteine modification
The present study was aimed to investigate the effects of curcumin, a representative chemopreventive phytochemical with pronounced antioxidant and anti-inflammatory properties, on activation of Nrf2 and expression of its target protein heme oxygenase-1 (HO-1) in mouse skin in vivo and in cultured murine epidermal cells. Treatment of mouse epidermal JB6 cells with curcumin resulted in the induction of HO-1 expression, and this was abrogated in cells transiently transfected with Nrf2 siRNA. While curcumin treatment increased protein expression of Nrf2, it did not alter the steady-state level of the Nrf2 mRNA transcript. Treatment of cells with curcumin stabilized Nrf2 by inhibiting ubiquitination and subsequent 26S proteasomal degradation of this transcription factor. Tetrahydrocurcumin, a non-electrophilic analogue of curcumin that lacks the alpha,beta-unsaturated carbonyl group, failed to induce HO-1 expression as well as nuclear translocation of Nrf2 and its binding to the antioxidant/electrophile response elements. Cells transfected with a mutant Keap1 protein in which cysteine 151 (Cys151) is replaced by serine exhibited marked reduction in curcumin-induced Nrf2 transactivation. Mass spectrometric analysis revealed that curcumin binds to Keap1 Cys151, supporting that this amino acid is a critical target for curcumin modification of Keap1, which facilitates the liberation of Nrf2. Thus, it is likely that the alpha,beta-unsaturated carbonyl moiety of curcumin is essential for its binding to Keap1 and stabilization of Nrf2 by hampering ubiquitination and proteasomal degradation.
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