All-optical flip flop based on a symmetric Mach-Zehnder switch with a feed-back loop and multiple forward set/reset signals

The paper proposed an improved performance for optical flip-flop using symmetric Mach-Zehnder interformeter with a feedback and multiple forward configurations. At the optimum operating condition for the optical flip-flop, high contrast ratio of 22 dB can be achieved. The findings in the paper will have an impact on the design of future optical flip-flop and other optical logic gates such as exclusive OR and NAND gates. A PhD research (Le-Minh) funded by the University Studentship, completed in 200

BER performance analysis of 100 and 200 Gbit/s all-optical OTDM node using symmetric Mach-Zehnder switches

New insight to the feasibility of all-optical ultra speed switching up to 200 Gb/s. The technique will reduce the dependency and bottleneck on the electronic-to-optical-to-electronic conversion. Current conversion speed is up to 40 Gb/s in laboratories. The novel clock extraction technique proposed shows the potential of an all-optical switch. The research results are directly relevant to the access technology where optical fibre and RF is competing to be the solution. The growing demands of bandwidth will exceed RF capability while the optical fibre will be the optimum solution. A PhD project (Le-Minh) funded by the University Studentship, completed in 2007

Simulation of an all-optical 1 x 2 SMZ switch with a high contrast ratio

Abstract — An all-optical 1×2 high contrast ratio (CR) switch based on the symmetric Mach-Zehnder (SMZ) interferometers is presented. Simulation results show a remarkable improvement of the inter-output CR (~25 dB) between the two outputs compared with an existing SMZ switch. It is shown that the proposed switch offers high values of inter-output CR (> 32dB) over a wide range of input powers using appropriate power of the control pulses. I

1 x M packet-switched router based on the PPM header address for all-optical WDM networks

This paper presents an all-optical 1xM router architecture for simultaneous multiple-wavelength packet routing, without the need for wavelength conversion. The packet header address is based on the pulse position modulation (PPM) format, which allows the use of only a single-bitwise optical AND gate for fast packet header address correlation. The proposed scheme offers both multicast and broadcast capabilities. We’ve demonstrated a high speed packet routing at 160 Gb/s in simulation, with a low channel crosstalk (CXT) of ~ -27 dB with a channel spacing of > 0.4 THz and a demultiplexer bandwidth of 500 GHz. The output transfer function of the PPM header processing (PPM-HP) module is also investigated in this paper

Investigations of Ni-SDC carbonate (Ni-SDCC) as composite anode for low temperature solid oxide fuel cells

Systematic research regarding NiO-SDC carbonate (NiO-SDCC) as composite anode is limited despite great chemical compatibility and cell performance achieved with other low temperature solid oxide fuel cell (LTSOFC) components. This study focuses to investigate the correlation of powder composition and calcination temperature on the chemical compatibility, morphologies, thermal and electrochemical performance of NiO-SDCC composite anode. NiO-SDCC composite powders with the weight ratios of 50:50 (NC55), 60:40 (NC64), and 70:30 (NC73) were achieved using high-energy ball-milling. All powders were calcined at 600–800 °C, pelletized and sintered at 600 °C. Characterisation include the crystalline phases, thermogravimetry, thermal expansion coefficient (TEC), hardness and morphologies were conducted. Electrochemical impedance spectroscopy (EIS) was conducted under in-situ reduction process. The powder and pellet morphologies, thermal expansion, and hardness were mostly affected by the calcination temperature as compared to powder composition. NC55 was selected for anode reduction process in hydrogen due for the least TEC values as compared to NC64 and NC73. The Ni-SDCC exhibited porosity of 36-40% after reduction process. The lowest area specific resistance of 5.3 Ωcm2 was achieved with sample calcined at 800 ℃. In this study, unexpected mechanical failure has been observed after EIS measurements. Therefore, chemical reactions and anode failure mechanisms were successfully proposed in this study. This mechanism is a new finding that has not been reported in previous studies and must be given appropriate attention. In conclusion, this study significantly contributes to the development of Ni-SDCC as LTSOFC composite anode. Further enhancement on this material is required on improved durability for LTSOFC application

PTPα regulates integrin-stimulated FAK autophosphorylation and cytoskeletal rearrangement in cell spreading and migration

We investigated the molecular and cellular actions of receptor protein tyrosine phosphatase (PTP) α in integrin signaling using immortalized fibroblasts derived from wild-type and PTPα-deficient mouse embryos. Defects in PTPα−/− migration in a wound healing assay were associated with altered cell shape and focal adhesion kinase (FAK) phosphorylation. The reduced haptotaxis to fibronectin (FN) of PTPα−/− cells was increased by expression of active (but not inactive) PTPα. Integrin-mediated formation of src–FAK and fyn–FAK complexes was reduced or abolished in PTPα−/− cells on FN, concomitant with markedly reduced phosphorylation of FAK at Tyr397. Reintroduction of active (but not inactive) PTPα restored FAK Tyr-397 phosphorylation. FN-induced cytoskeletal rearrangement was retarded in PTPα−/− cells, with delayed filamentous actin stress fiber assembly and focal adhesion formation. This mimicked the effects of treating wild-type fibroblasts with the src family protein tyrosine kinase (Src-PTK) inhibitor PP2. These results, together with the reduced src/fyn tyrosine kinase activity in PTPα−/− fibroblasts (Ponniah et al., 1999; Su et al., 1999), suggest that PTPα functions in integrin signaling and cell migration as an Src-PTK activator. Our paper establishes that PTPα is required for early integrin-proximal events, acting upstream of FAK to affect the timely and efficient phosphorylation of FAK Tyr-397

Data analysis of the U–Pb geochronology and Lu–Hf system in zircon and whole-rock Sr, Sm–Nd and Pb isotopic systems for the granitoids of Thailand

© 2018 This data article provides zircon U–Pb and Lu–Hf isotopic information along with whole-rock Sm–Nd, Sr and Pb isotopic geochemistry from granitoids in Thailand. The U–Pb ages are described and the classification of crystallisation and inherited ages are explained. The petrography of the granitoid samples is detailed. The data presented in this article are interpreted and discussed in the research article entitled “Probing into Thailand's basement: New insights from U–Pb geochronology, Sr, Sm–Nd, Pb and Lu–Hf isotopic systems from granitoids” (Dew et al., 2018)

Quality of life among people living with hypertension in a rural Vietnam community

Background - To respond to growing prevalence of hypertension in Vietnam, it is critical to have an in-depth understanding about quality of life (QOL) among people living with hypertension and related factors. This study aimed to measure QOL among hypertensive people in a rural community in Vietnam, and its association with socio-demographic characteristics and factors related to treatment. Methods - This study was conducted in a rural community located 60 km from Ho Chi Minh City. Face-to-face interviews were conducted among 275 hypertensive people aged 50 years and above using WHOQOL-BREF questionnaire. Descriptive statistics were used to examine mean scores of quality of life. Cronbach’s alpha coefficient and Pearson’s correlation coefficient were applied to estimate the internal consistency, and the level of agreement between different domains of WHOQOL-BREF, respectively. Independent T-test and ANOVA test followed by multiple linear regression analyses were used to measure the association between QOL domains and independent variables. Results - Both overall WHOQOL-BREF and each domain had a good internal consistency, ranging from 0.65 to 0.88. The QOL among hypertensive patients was found moderate in all domains, except for psychological domain that was fairly low (mean = 49.4). Backward multiple linear regressions revealed that being men, married, attainment of higher education, having physical activities at moderate level, and adherence to treatment were positively associated with QOL. However, older age and presence of co-morbidity were negatively associated with QOL. Conclusion - WHOQOL-BREF is a reliable instrument to measure QOL among hypertensive patients. The results revealed low QOL in psychological domain and inequality in QOL across socio-demographic characteristics. Given the results, encouraging physical activities and strengthening treatment adherence should be considered to improve QOL of hypertensive people, especially for psychological aspect. Actions to improve QOL among hypertensive patients targeted towards women, lower educated and unmarried patients are needed in the setting

Systems microscopy approaches to understand cancer cell migration and metastasis

Cell migration is essential in a number of processes, including wound healing, angiogenesis and cancer metastasis. Especially, invasion of cancer cells in the surrounding tissue is a crucial step that requires increased cell motility. Cell migration is a well-orchestrated process that involves the continuous formation and disassembly of matrix adhesions. Those structural anchor points interact with the extra-cellular matrix and also participate in adhesion-dependent signalling. Although these processes are essential for cancer metastasis, little is known about the molecular mechanisms that regulate adhesion dynamics during tumour cell migration. In this review, we provide an overview of recent advanced imaging strategies together with quantitative image analysis that can be implemented to understand the dynamics of matrix adhesions and its molecular components in relation to tumour cell migration. This dynamic cell imaging together with multiparametric image analysis will help in understanding the molecular mechanisms that define cancer cell migration