91 research outputs found
Dynamics of Scalar field in a Brane World
We study the dynamics of a scalar field in the brane cosmology. We assume
that a scalar field is confined in our 4-dimensional world. As for the
potential of the scalar field, we discuss three typical models: (1) a power-law
potential, (2) an inverse-power-law potential, and (3) an exponential
potential. We show that the behavior of the scalar field is very different from
a conventional cosmology when the energy density square term is dominated.Comment: 15pages, 8figures, submitted to Physical Review
Feasibility study of chemoradiotherapy followed by amrubicin and cisplatin for limited-disease small cell lung cancer
To evaluate the feasibility of amrubicin plus cisplatin (AP) following chemoradiotherapy for limited-disease small-cell lung cancer, chemo-naïve patients aged 20–70 years with a performance status of 0 or 1 and normal organ functions were treated with etoposide 100 mg/m2 on days 1–3, cisplatin 80 mg/m2 on day 1 and concurrent thoracic radiotherapy at 45 Gy/30 fractions (EP-TRT), followed by three cycles of amrubicin 40 mg/m2 on days 1–3 and cisplatin 60 mg/m2 on day 1 every 3 weeks. The EP-TRT could be completed in 21 patients (15 male and 6 female patients with a median age of 62 years). Of these, 2, 1 and 18 (86%) patients received one, two and three cycles of AP, respectively. Sixteen (76%) patients required granulocyte-colony stimulating factor (G-CSF) support. Grade 3/4 neutropenia occurred in all patients. Grade 3 febrile neutropenia was observed in 9 patients, lasting for 1 day in 5 patients. The incidences of grade 3/4 thrombocytopenia and anemia were 43 and 24%, respectively. Grade 3 infection and anorexia occurred in 2 and 3 patients, respectively. The response rate was 95%. The median (95% confidence interval [CI]) progression-free survival (PFS) was 41.9 (0–102) months, and the 5-year PFS rate (CI) was 41.9% (20.4–63.4%). The median overall survival (OS) has not been reached yet, and the 5-year OS rate (CI) was 57.8% (35.2–80.4%). In conclusion, EP-TRT followed by AP therapy was well-tolerated, although a large number of patients required G-CSF support
Brane Big-Bang Brought by Bulk Bubble
We propose an alternative inflationary universe scenario in the context of
Randall-Sundrum braneworld cosmology. In this new scenario the existence of
extra-dimension(s) plays an essential role. First, the brane universe is
initially in the inflationary phase driven by the effective cosmological
constant induced by small mismatch between the vacuum energy in the
5-dimensional bulk and the brane tension. This mismatch arises since the bulk
is initially in a false vacuum. Then, the false vacuum decay occurs, nucleating
a true vacuum bubble with negative energy inside the bulk. The nucleated bubble
expands in the bulk and consequently hits the brane, bringing a hot big-bang
brane universe of the Randall-Sundrum type. Here, the termination of the
inflationary phase is due to the change of the bulk vacuum energy. The bubble
kinetic energy heats up the universe. As a simple realization, we propose a
model, in which we assume an interaction between the brane and the bubble. We
derive the constraints on the model parameters taking into account the
following requirements: solving the flatness problem, no force which prohibits
the bubble from colliding with the brane, sufficiently high reheating
temperature for the standard nucleosynthesis to work, and the recovery of
Newton's law up to 1mm. We find that a fine tuning is needed in order to
satisfy the first and the second requirements simultaneously, although, the
other constraints are satisfied in a wide range of the model parameters.Comment: 20pages, 5figures, some references added, the previous manuscript has
been largely improve
Measurement and comparison of individual external doses of high-school students living in Japan, France, Poland and Belarus -- the "D-shuttle" project --
Twelve high schools in Japan (of which six are in Fukushima Prefecture), four
in France, eight in Poland and two in Belarus cooperated in the measurement and
comparison of individual external doses in 2014. In total 216 high-school
students and teachers participated in the study. Each participant wore an
electronic personal dosimeter "D-shuttle" for two weeks, and kept a journal of
his/her whereabouts and activities. The distributions of annual external doses
estimated for each region overlap with each other, demonstrating that the
personal external individual doses in locations where residence is currently
allowed in Fukushima Prefecture and in Belarus are well within the range of
estimated annual doses due to the background radiation level of other
regions/countries
The Role of Climate Variability in the Spread of Malaria in Bangladeshi Highlands
Malaria is a major public health problem in Bangladesh, frequently occurring as epidemics since the 1990s. Many factors affect increases in malaria cases, including changes in land use, drug resistance, malaria control programs, socioeconomic issues, and climatic factors. No study has examined the relationship between malaria epidemics and climatic factors in Bangladesh. Here, we investigate the relationship between climatic parameters [rainfall, temperature, humidity, sea surface temperature (SST), El Niño-Southern Oscillation (ENSO), the normalized difference vegetation index (NDVI)], and malaria cases over the last 20 years in the malaria endemic district of Chittagong Hill Tracts (CHT)
Carbon Nanotube Fabrication at Industrial Scale: Opportunities and Challenges
Careful research on different materials reveals that the material properties
are mostly affected by the size of it. Material size down to nanometer scale
exhibits some remarkable properties, resulting in unique physical and chemical
characteristics. In todays world of nanotechnology, carbon nanotubes (CNTs)
have become a high priority material because of their exclusive structure,
novel characteristics with enormous potential in many technological
applications. Till date chemical vapor deposition (CVD) is the preferred and
widely used technique among different CNT growth methods, because of its
potential advantage to produce CNTs of high purity, large yield with ease of
scale up and low setup cost. This article provides an overview of different CVD
methods for industrial scale fabrication of CNTs. The influence of material
aspect, viz. catalyst type, catalyst support, and growth control aspect, viz.
process temperature, pressure, catalyst concentration, are discussed.
Additionally, possible growth mechanisms concerning CNT formation are
described. Finally, the key challenges of the process are addressed with future
perspective.Comment: carbon nanotubes, chemical vapor depositio
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