Fully integrated InGaAs/InP single-photon detector module with gigahertz sine wave gating

InGaAs/InP single-photon avalanche diodes (SPADs) working in the regime of GHz clock rates are crucial components for the high-speed quantum key distribution (QKD). We have developed for the first time a compact, stable and user-friendly tabletop InGaAs/InP single-photon detector system operating at a 1.25 GHz gate rate that fully integrates functions for controlling and optimizing SPAD performance. We characterize the key parameters of the detector system and test the long-term stability of the system for continuous operation of 75 hours. The detector system can substantially enhance QKD performance and our present work paves the way for practical high-speed QKD applications.Comment: 11 pages, 6 figures. Accepted for publication in Review of Scientific Instrument

Domain Wall Conduction in Calcium-Modified Lead Titanate for Polarization Tunable Photovoltaic Devices

Ferroelectric domain wall (DW) conduction, confirmed in recent experiments, has attracted intense attention due to its promising applications in optoelec- tronic devices. Herein, we provide theoretical evidence of electric conduction in Pb0.8Ca0.2TiO3 (PCT) DWs. The separation of charge accumulation in DWs, corresponding to the electronic conduction-band minimum (CBM) and valence-band maximum (VBM), weakens the tendency for the electron-hole recombination, thereby providing more efficient channels for charge transfer. We fabricate PCT-based functional photovoltaic devices with polarization tunable charge transfer to exploit the combined conduction and ferroelectric properties of the DW. The photovoltaic performance of the devices can be regu- lated by the alternation of ferroelectric domains in PCT, caused by variation of the external poling. Our work broadens the applicability of DW conduction and may inspire the future design of high-performance materials in photovoltaic devices

Increased nucleotide polymorphic changes in the 5'-untranslated region of δ-catenin (CTNND2) gene in prostate cancer

Cancer pathogenesis involves multiple genetic and epigenetic alterations, which result in oncogenic changes in gene expression. δ-Catenin (CTNND2) is overexpressed in cancer although the mechanisms of its upregulation are highly variable. Here we report that in prostate cancer the methylation of CpG islands in δ-catenin promoter was not a primary regulatory event. There was also no δ-catenin gene amplification. However, using Single-Strand onformation Polymorphism analysis, we observed the increased nucleotide changes in the 5'-untranslated region of δ-catenin gene in human prostate cancer. At least one such change (-9 G>A) is a true somatic point mutation associated with a high Gleason score, poorly differentiated prostatic adenocarcinoma. Laser capture microdissection coupled with PCR analyses detected the mutation only in cancerous but not in the adjacent benign prostatic tissues. Using chimeric genes encoding the luciferase reporter, we found that this mutation, but not a random mutation or a mutation that disrupts an upstream open reading frame, resulted in a remarkably higher expression and enzyme activity. This mutation did not affect transcriptional efficiency, suggesting that it promotes δ-catenin translation. This is the first report of δ-catenin gene mutation in cancer and supports the notion that multiple mechanisms contribute to its increased expression in carcinogenesis. Originally published ncogene, Vol. 28, No. 4, Jan 200

Peripheral Direct Adjacent Lobe Invasion Non-small Cell Lung Cancer Has a Similar Survival to That of Parietal Pleural Invasion T3 Disease

IntroductionThe postoperative prognosis of peripheral adjacent lobe invasion non-small cell lung cancer (NSCLC) is unclear. The purpose of this study was to determine the postoperative prognosis of NSCLC with direct adjacent lobe invasion by comparing it with that of visceral pleural invasion (primary lobe) T2 disease, and parietal pleural invasion T3 disease, and hence determine its most appropriate T category.MethodsA retrospective analysis was conducted to assess the survival of patients with peripheral direct adjacent lobe invasion NSCLC (group A), and it was compared with that of patients with visceral pleural invasion of the primary lobe (group B) and parietal pleural invasion (group C). All patients were node-negative on pathologic examination. Kaplan-Meier method was used to compare the postoperative survival between groups.ResultsA total of 263 patients were analyzed. The overall survival rates in groups A (n = 28), B (n = 167), and C (n = 68) at 5 years were 40.7, 54.6, and 41.9%, respectively; corresponding median survival in three groups were 53, 71, and 40 months, respectively. The survival difference among three groups was statistically significant (p = 0.031). A similar survival was observed between groups A and C, whereas group B had a much better survival than other groups.ConclusionsPeripheral adjacent lobe invasion NSCLC has a similar survival prognosis with that of parietal pleural invasion T3 disease and hence should be classified as T3 rather than T2. However, further studies are warranted