Epidemiological, clinical and laboratory characteristics of 19 serologically confirmed rickettsial disease in Singapore.

AIM: To identify epidemiological, clinical and laboratory features of serologically-proven typhus in the local setting. METHOD & RESULTS: Retrospective study looking at rickettsial serologies done over a six-month period and collection of the epidemological, clinical, laboratory and treatment response data from the case notes of the patients with an ordered rickettsial serology. Twenty of the 35 cases had a positive serology. Of these 20 patients, 18 were already clinically diagnosed as having murine typhus. All except one were males and all were migrant workers. Majority of the patients were construction workers staying in containers where rats abound. The most consistent clinical features were high fever (100%) for a median period of seven days, headache (94%) and cough (47%). The white cell count was usually normal (74%) but thrombocytopenia was common (68%). Transaminitis was also common (90%) with the AST component higher than the ALT in half of the cases. Response to doxycycline therapy was rapid and most (88%) were afebrile by 72 hours. CONCLUSION: Typhus (notably murine type) can be confidently diagnosed from consistent clinical features supported by epidemiological and laboratory clues. Early recognition with the prompt treatment response will result in shorter hospital stay with decreased cost. Serological testing may only prove useful in difficult situations when the clinical diagnosis is less clear

Precise control of phase transformation process in lead zirconate titanate thin films by focused line-beam scanning

Phase transformation and grain growth processes of lead zirconate titanate (PZT) thin films have been precisely controlled by using focused line-beam scanning. The authors promoted the lateral crystallization of PZT grains by controlling a nucleation process and increasing the size of single grains to be as large as 40 μm in length. Focused line-beam scanning allows for the selective growth and crystallization of large PZT grains on predetermined nucleation sites. The high growth rate of the selected PZT grains was attributed to successive suppression of undesirable nucleation except at predetermined positions when pretreated PZT films were exposed to the focused line beam. © 2007 American Institute of Physics

Local structure and medium-range ordering in relaxor ferroelectric Pb(Zn <inf>1/3</inf>Nb <inf>2/3</inf>)O <inf>3</inf> studied using neutron pair distribution function analysis

We studied an evolution of local structure and medium-range ordering in relaxor ferroelectric Pb(Zn 1/3Nb 2/3)O 3 (PZN) from 550 to 15 K using neutron pair distribution function analysis. We show that the local structure of PZN is distorted at all temperatures studied. With decreasing temperature, a medium-range ordering of local polarizations develops with no global rhombohedral phase transition below T M. Instead, the crystal structure can be described as a mixture of polar nanoregions in a disordered lattice, similar to the case of Pb(Mg 1/3Nb 2/3)O 3. © 2006 American Institute of Physics

EEG findings of reduced neural synchronization during visual integration in schizophrenia

Schizophrenia patients exhibit well-documented visual processing deficits. One area of disruption is visual integration, the ability to form global objects from local elements. However, most studies of visual integration in schizophrenia have been conducted in the context of an active attention task, which may influence the findings. In this study we examined visual integration using electroencephalography (EEG) in a passive task to elucidate neural mechanisms associated with poor visual integration. Forty-six schizophrenia patients and 30 healthy controls had EEG recorded while passively viewing figures comprised of real, illusory, or no contours. We examined visual P100, N100, and P200 event-related potential (ERP) components, as well as neural synchronization in the gamma (30-60 Hz) band assessed by the EEG phase locking factor (PLF). The N100 was significantly larger to illusory vs. no contour, and illusory vs. real contour stimuli while the P200 was larger only to real vs. illusory stimuli; there were no significant interactions with group. Compared to controls, patients failed to show increased phase locking to illusory versus no contours between 40-60 Hz. Also, controls, but not patients, had larger PLF between 30-40 Hz when viewing real vs. illusory contours. Finally, the positive symptom factor of the BPRS was negatively correlated with PLF values between 40-60 Hz to illusory stimuli, and with PLF between 30-40 Hz to real contour stimuli. These results suggest that the pattern of results across visual processing conditions is similar in patients and controls. However, patients have deficits in neural synchronization in the gamma range during basic processing of illusory contours when attentional demand is limited

Principles of structural safety studies

This chapter addresses principles of advanced structural safety studies in association with various types of extreme and accidental events. The structural consequences of extreme conditions and accidents are inevitably volatile, uncertain, complex, and ambiguous (VUCA). Methods to model random parameters affecting such extreme conditions and accidents are presented. The importance of limit states- and risk-based approaches is emphasized to manage VUCA environments. Future trends toward advanced structural safety studies are addressed

Tunable surface plasmons of dielectric core-metal shell particles for dye sensitized solar cells

Our findings show that the extinction spectrum of core-shell type plasmonic particles can be effectively controlled by changing their geometric factor. This tuning capability allows the surface plasmons of the core-shell particles to be designed in such a way that the absorption of dye molecules is maximized in dye sensitized solar cells. When plasmonic particles with a metallic nanoshell and a dielectric core are incorporated into a TiO2 mesoporous photoelectrode, the optical cross section of dye sensitizers and the energy conversion efficiency of dye-sensitized solar cells (DSSCs) are increased. The enhanced photon-electron conversion is attributed to localized surface plasmons of the core-shell particles, which increase the absorption and scattering of incoming light in the photoelectrode. © 2013 The Royal Society of Chemistry