Variation of structural vibration characteristics versus non-uniform temperature distribution

Author name used in this manuscript: You-Lin Xu2010-2011 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

The Quantized Hall Insulator: A New Insulator in Two-Dimensions

Quite generally, an insulator is theoretically defined by a vanishing conductivity tensor at the absolute zero of temperature. In classical insulators, such as band insulators, vanishing conductivities lead to diverging resistivities. In other insulators, in particular when a high magnetic field (B) is added, it is possible that while the magneto-resistance diverges, the Hall resistance remains finite, which is known as a Hall insulator. In this letter we demonstrate experimentally the existence of another, more exotic, insulator. This insulator, which terminates the quantum Hall effect series in a two-dimensional electron system, is characterized by a Hall resistance which is approximately quantized in the quantum unit of resistance h/e^2. This insulator is termed a quantized Hall insulator. In addition we show that for the same sample, the insulating state preceding the QHE series, at low-B, is of the HI kind.Comment: 4 page

Spectral weight transfer in a disorder-broadened Landau level

In the absence of disorder, the degeneracy of a Landau level (LL) is $N=BA/\phi_0$, where $B$ is the magnetic field, $A$ is the area of the sample and $\phi_0=h/e$ is the magnetic flux quantum. With disorder, localized states appear at the top and bottom of the broadened LL, while states in the center of the LL (the critical region) remain delocalized. This well-known phenomenology is sufficient to explain most aspects of the Integer Quantum Hall Effect (IQHE) [1]. One unnoticed issue is where the new states appear as the magnetic field is increased. Here we demonstrate that they appear predominantly inside the critical region. This leads to a certain ``spectral ordering'' of the localized states that explains the stripes observed in measurements of the local inverse compressibility [2-3], of two-terminal conductance [4], and of Hall and longitudinal resistances [5] without invoking interactions as done in previous work [6-8].Comment: 5 pages 3 figure

Efficient and long-lived quantum memory with cold atoms inside a ring cavity

Quantum memories are regarded as one of the fundamental building blocks of linear-optical quantum computation and long-distance quantum communication. A long standing goal to realize scalable quantum information processing is to build a long-lived and efficient quantum memory. There have been significant efforts distributed towards this goal. However, either efficient but short-lived or long-lived but inefficient quantum memories have been demonstrated so far. Here we report a high-performance quantum memory in which long lifetime and high retrieval efficiency meet for the first time. By placing a ring cavity around an atomic ensemble, employing a pair of clock states, creating a long-wavelength spin wave, and arranging the setup in the gravitational direction, we realize a quantum memory with an intrinsic spin wave to photon conversion efficiency of 73(2)% together with a storage lifetime of 3.2(1) ms. This realization provides an essential tool towards scalable linear-optical quantum information processing.Comment: 6 pages, 4 figure

Tumor Necrosis Impacts Prognosis of Patients Undergoing Curative-Intent Hepatocellular Carcinoma

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Anti-epileptic effect of Ganoderma lucidum polysaccharides by inhibition of intracellular calcium accumulation and stimulation of expression of CaMKII a in epileptic hippocampal neurons

Purpose: To investigate the mechanism of the anti-epileptic effect of Ganoderma lucidum polysaccharides (GLP), the changes of intracellular calcium and CaMK II a expression in a model of epileptic neurons were investigated. Method: Primary hippocampal neurons were divided into: 1) Control group, neurons were cultured with Neurobasal medium, for 3 hours; 2) Model group I: neurons were incubated with Mg2+ free medium for 3 hours; 3) Model group II: neurons were incubated with Mg2+ free medium for 3 hours then cultured with the normal medium for a further 3 hours; 4) GLP group I: neurons were incubated with Mg2+ free medium containing GLP (0.375 mg/ml) for 3 hours; 5) GLP group II: neurons were incubated with Mg2+ free medium for 3 hours then cultured with a normal culture medium containing GLP for a further 3 hours. The CaMK II a protein expression was assessed by Western-blot. Ca2+ turnover in neurons was assessed using Fluo-3/AM which was added into the replacement medium and Ca2+ turnover was observed under a laser scanning confocal microscope. Results: The CaMK II a expression in the model groups was less than in the control groups, however, in the GLP groups, it was higher than that observed in the model group. Ca2+ fluorescence intensity in GLP group I was significantly lower than that in model group I after 30 seconds, while in GLP group II, it was reduced significantly compared to model group II after 5 minutes. Conclusion: GLP may inhibit calcium overload and promote CaMK II a expression to protect epileptic neuron

Postoperative Infectious Complications Worsen Long-Term Survival After Curative-Intent Resection for Hepatocellular Carcinoma

Background: Postoperative infectious complications may be associated with a worse long-term prognosis for patients undergoing surgery for a malignant indication. The current study aimed to characterize the impact of postoperative infectious complications on long-term oncologic outcomes among patients undergoing resection for hepatocellular carcinoma (HCC). Methods: Patients who underwent curative-intent resection for HCC between 2000 and 2017 were identified from an international multi-institutional database. The relationship between postoperative infectious complications, overall survival (OS), and recurrence-free survival (RFS) was analyzed. Results: Among 734 patients who underwent HCC resection, 269 (36.6%) experienced a postoperative complication (Clavien-Dindo grade 1 or 2 [n = 197, 73.2%] vs grade 3 and 4 [n = 69, 25.7%]). An infectious complication was noted in 81 patients (11.0%) and 188 patients (25.6%) had non-infectious complications. The patients with infectious complications had worse OS (median: infectious complications [46.5 months] vs no complications [106.4 months] [p < 0.001] and non-infectious complications [85.7 months] [p < 0.05]) and RFS (median: infectious complications [22.1 months] vs no complications [45.5 months] [p < 0.05] and non-infectious complications [38.3 months] [p = 0.139]) than the patients who had no complication or non-infectious complications. In the multivariable analysis, infectious complications remained an independent risk factor for OS (hazard ratio [HR], 1.7; p = 0.016) and RFS (HR, 1.6; p = 0.013). Among the patients with infectious complications, patients with non-surgical-site infection (SSI) had even worse OS and RFS than patients with SSI (median OS: 19.5 vs 70.9 months [p = 0.010]; median RFS: 12.8 vs 33.9 months [p = 0.033]). Conclusion: Infectious complications were independently associated with an increased long-term risk of tumor recurrence and death. Patients with non-SSI versus SSI had a particularly worse oncologic outcome.info:eu-repo/semantics/publishedVersio

Multi-Institutional Development and External Validation of a Nomogram for Prediction of Extrahepatic Recurrence After Curative-Intent Resection for Hepatocellular Carcinoma

Backgrounds: Extrahepatic recurrence of hepatocellular carcinoma (HCC) after surgical resection is associated with unfavorable prognosis. The objectives of the current study were to identify the risk factors and develop a nomogram for the prediction of extrahepatic recurrence after initial curative surgery. Methods: A total of 635 patients who underwent curative-intent resection for HCC between 2000 and 2017 were identified from an international multi-institutional database. The clinicopathological characteristics, risk factors, and long-term survival of patients with extrahepatic recurrence were analyzed. A nomogram for the prediction of extrahepatic recurrence was established and validated in 144 patients from an external cohort. Results: Among the 635 patients in the derivative cohort, 283 (44.6%) experienced recurrence. Among patients who recurred, 80 (28.3%) patients had extrahepatic ± intrahepatic recurrence, whereas 203 (71.7%) had intrahepatic recurrence only. Extrahepatic recurrence was associated with more advanced initial tumor characteristics, early recurrence, and worse prognosis versus non-extrahepatic recurrence. A nomogram for the prediction of extrahepatic recurrence was developed using the β-coefficients from the identified risk factors, including neutrophil-to-lymphocyte ratio, multiple lesions, tumor size, and microvascular invasion. The nomogram demonstrated good ability to predict extrahepatic recurrence (c-index: training cohort 0.786; validation cohort: 0.845). The calibration plots demonstrated good agreement between estimated and observed extrahepatic recurrence (p = 0.658). Conclusions: An externally validated nomogram was developed with good accuracy to predict extrahepatic recurrence following curative-intent resection of HCC. This nomogram may help identify patients at high risk of extrahepatic recurrence and guide surveillance protocols as well as adjuvant treatments.info:eu-repo/semantics/publishedVersio