Timescale Spectra in High Energy Astrophysics

A technique of timescale analysis performed directly in the time domain has been developed recently. We have applied the technique to studying rapid variabilities of hard X-rays from neutron star and black hole binaries, gamma-ray bursts and terrestrial gamma-ray flashes. The results indicate that the time domain method of spectral analysis is a powerful tool in revealing the underlying physics in high-energy processes in objects.Comment: 7 pages, 4 figures. Invited talk at the 6th Pacific Rim Conference on Steller Astrophysic

Characteristic Variability Time Scales of Long Gamma-Ray Bursts

We determined the characteristic variability time scales (\Delta t_p) of 410 bright and long GRBs, by locating the peaks of their Power Density Spectra, defined and calculated in the time domain. We found that the averaged variability time scale decreases with the peak flux. This is consistent with the time-dilation effect expected for the cosmological origin of GRBs. We also found that the occurrence distribution of the characteristic variability time scale shows bimodality, which might be interpreted as that the long GRB sample is composed of two sub-classes with different variability time scales. However, we found no difference for some other characteristics of these two sub-classes.Comment: 10 pages, 5 figures, corrected some typos and syntaxes, enlarged the label fonts in fig.3 and fig.

Interface trap generation by FN injection under dynamic oxide field stress

Interface trap generation under dynamic (bipolar and unipolar) and dc oxide field stress has been investigated with the charge pumping technique. It is observed that regardless of stress type, whether dc or dynamic (bipolar or unipolar), and the polarity of stress voltage, interface trap generation starts to occur at the voltage at which Fowler-Nordheim (FN) tunneling through the oxide starts to build up. For positive voltage, interface trap generation is attributed to the recombination of trapped holes with electrons and to the bond breaking by the hydrogen (H and H+) released during stressing. For negative voltage, in addition to these two mechanisms, the bond breaking by energetic electrons may also contribute to interface trap generation. The frequency dependence of interface trap generation is also investigated. Interface trap generation is independent of stressing frequency for unipolar stress but it shows a frequency dependence for bipolar stress. ©1998 IEEE.published_or_final_versio

家庭醫生與非家庭醫生對於香港家庭醫學專科培訓所持意見的異同

目的: 探討本地醫生對家庭醫學專科培訓的意見，以作將來規劃醫療體制的參考。 設計: 橫斷面研究。 參與者及安排: 香港所有註冊醫生。 主要結果測量: 醫生對以下幾方面的評價：職業培訓的重要性、專業評核、工作性質和成為家庭醫生所需經驗，以及他們對於職業培訓所需年期的意見。 結果: 共2310位醫生完成問卷，佔本地醫生23%。最多醫生同意專業評核應為資格認可的因素，其他依次為職業培訓、臨床經驗及工作性質。七成以上受訪醫生認為培訓期應為四年或以下。非家庭醫生大多選擇專業評核作為資格認可的因素，他們亦傾向較長的培訓期。 結論: 職業培訓被認為是獲得家庭醫學專科資格的重要因素。大多數醫生認為培訓期應為四年或以下，而非香港醫學專科學院現時所訂立的六年期。因此，現時家庭醫學的職業培訓計劃或有檢討的需要。Objective: To study the local medical profession's opinions on the training requirements for the specialty of family medicine. This was to serve as a reference for future planning of the health care system. Design: Cross-sectional study. Participants and Setting: All registered doctors in Hong Kong. Main outcome measures: Doctors' ratings on the importance of vocational training, professional assessment, job nature, and experience to become suitably qualified as a family doctor, and their opinions on the length of necessary vocational training. Results: A total of 2310 doctors (23% of doctors in the local register) responded. Professional assessment was mostly agreed as a qualification, followed by vocational training, clinical experience, and job nature. Over 70% agreed on a training period of 4 years or less. Non-family doctors were more likely to opt for professional assessment as the qualification and also opt for a longer training period. Conclusion: Vocational training was considered important as a qualification for the specialty of family medicine. The length of training was mostly agreed to be 4 years or less, not the 6 years currently required by the Hong Kong Academy of Medicine. The vocational training programme for family medicine might require reexamination.published_or_final_versio

Post-stress interface trap generation induced by oxide-field stress with FN injection

Interface trap generation in nMOS transistors during both stressing and post-stress periods under the conditions of oxide field (dynamic and dc) stress with FN injection is investigated with charge pumping technique. In contrast to the post-stress interface trap generation induced by hot carrier stress which is a logarithmical function of post-stress time, the poststress interface trap generation induced by oxide-field stress with FN injection first increases with post-stress time but then becomes saturated. The mechanisms for the interface trap generation in both stressing and post-stress periods are described. © 1998 IEEE.published_or_final_versio

Wrist-Ankle Acupuncture for the Treatment of Pain Symptoms: A systematic Review and Meta-analysis

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Genes encoding Pir51, Beclin 1, RbAp48 and aldolase b are up or down-regulated in human primary hepatocellular carcinoma

Aim: To reveal new tumor markers and target genes from differentially expressed genes of primary tumor samples using cDNA microarray. Methods: The 33P labeled cDNAs were synthesized by reverse transcription of message RNA from the liver cancerous tissue and adjacent non-cancerous liver tissue from the same patient and used to hybridize to LifeGrid 1.0 cDNA microarray blot containing 8400 known and unique human cDNA gene targets, and an expression profile of genes was produced in one paired human liver tumor tissue. After a global analysis of gene expression of 8400 genes, we selected some genes to confirm the differential expression using Northern blot and RT-PCR. Results: Parallel analysis of the hybridized signals enabled us to get an expression profile of genes in which about 500 genes were differentially expressed in the paired liver tumor tissues. We identified 4 genes, the expression of three (Beclin 1, RbAp48 and Pir51) were increased and one (aldolase b) was decreased in liver tumor tissues. In addition, the expression of these genes in 6 hepatoma cell lines was also showed by RT-PCR analysis. Conclusion: cDNA microarray permits a high throughput identification of changes in gene expression. The genes encoding Beclin 1, RbAp48, Pir51 and aldolase b are first reported that may be related with hepatocarcinoma. Copyright © 2004 by The WJG Press ISSN 1007-9327.published_or_final_versio

In Situ Structure Characterization in Slot-Die-Printed All-Polymer Solar Cells with Efficiency Over 9%

Herein, high-performance printed all-polymer solar cells (all-PSCs) based on a bulk-heterojunction (BHJ) blend film are demonstrated using PTzBI as the donor and N2200 as the acceptor. A slot-die process is used to prepare the BHJ blend, which is a cost-effective, high-throughput approach to achieve large-area photovoltaic devices. The real-time crystallization of polymers in the film drying process is investigated by in situ grazing incidence wide-angle X-ray scattering characterization. Printing is found to significantly improve the crystallinity of the polymer blend in comparison with spin coating. Moreover, printing with 1,8-diiodooctane as the solvent additive enhances the polymer aggregation and crystallization during solvent evaporation, eventually leading to multi-length-scale phase separation, with PTzBI-rich domains in-between the N2200 crystalline fibers. This unique morphology achieved by printing fabrication results in an impressively high power conversion efficiency of 9.10%, which is the highest efficiency reported for printed all-PSCs. These findings provide important guidelines for controlling film drying dynamics for processing all-PSCs

Pathological behaviour of the scalar graviton in Ho\v{r}ava-Lifshitz gravity

We confirm the recent claims that, in the infrared limit of Ho\v{r}ava-Lifshitz gravity, the scalar graviton becomes a ghost if the sound speed squared is positive on the flat de Sitter and Minkowski background. In order to avoid the ghost and tame the instability, the sound speed squared should be negative and very small, which means that the flow parameter $\lambda$ should be very close to its General Relativity (GR) value. We calculate the cubic interactions for the scalar graviton which are shown to have a similar structure with those of the curvature perturbation in k-inflation models. The higher order interactions become increasing important for a smaller sound speed squared, that is, when the theory approaches GR. This invalidates any linearized analysis and any predictability is lost in this limit as quantum corrections are not controllable. This pathological behaviour of the scalar graviton casts doubt on the validity of the projectable version of the theory.Comment: 7 pages, references added; v3: Typos corrected, minor changes to text and precise determination of the strong coupling scale. Replaced to match published version

Interferon-gamma inducible protein 10 (IP10) induced cisplatin resistance of HCC after liver transplantation through ER stress signaling pathway.

Tumor recurrence remains an obstacle after liver surgery, especially in living donor liver transplantation (LDLT) for patients with hepatocellular carcinoma (HCC). The acute-phase liver graft injury might potentially induce poor response to chemotherapy in recurrent HCC after liver transplantation. We here intended to explore the mechanism and to identify a therapeutic target to overcome such chemoresistance. The associations among graft injury, overexpression of IP10 and multidrug resistant genes were investigated in a rat liver transplantation model, and further validated in clinical cohort. The role of IP10 on HCC cell proliferation and tumor growth under chemotherapy was studied both in vitro and in vivo. The underlying mechanism was revealed by detecting the activation of endoplasmic reticulum (ER) stress signaling pathways. Moreover, the effect of IP10 neutralizing antibody sensitizing cisplatin treatment was further explored. In rat liver transplantation model, significant up-regulation of IP10 associated with multidrug resistant genes was found in small-for-size liver graft. Clinically, high expression of circulating IP10 was significant correlated with tumor recurrence in HCC patients underwent LDLT. Overexpression of IP10 promoted HCC cell proliferation and tumor growth under cisplatin treatment by activation of ATF6/Grp78 signaling. IP10 neutralizing antibody sensitized cisplatin treatment in nude mice. The overexpression of IP10, which induced by liver graft injury, may lead to cisplatin resistance via ATF6/Grp78 ER stress signaling pathway. IP10 neutralizing antibody could be a potential adjuvant therapy to sensitize cisplatin treatment