Hawking Radiation for Scalar and Dirac Fields in Five Dimensional Dilatonic Black Hole via Anomalies

We study massive scalar fields and Dirac fields propagating in a five dimensional dilatonic black hole background. We expose that for both fields the physics can be describe by a two dimensional theory, near the horizon. Then, in this limit, by applying the covariant anomalies method we find the Hawking flux by restoring the gauge invariance and the general coordinate covariance, which coincides with the flux obtained from integrating the Planck distribution for fermions.Comment: 10 page

Superconducting properties of nanocrystalline MgB2_2 thin films made by an in situ annealing process

We have studied the structural and superconducting properties of MgB$_2$ thin films made by pulsed laser deposition followed by in situ annealing. The cross-sectional transmission electron microscopy reveals a nanocrystalline mixture of textured MgO and MgB$_2$ with very small grain sizes. A zero-resistance transition temperature ($T_{c0}$) of 34 K and a zero-field critical current density ($J_c$) of $1.3 \times 10^6$ A/cm$^2$ were obtained. The irreversibility field was $\sim$ 8 T at low temperatures, although severe pinning instability was observed. These bulk-like superconducting properties show that the in situ deposition process can be a viable candidate for MgB$_2$ Josephson junction technologies

In-situ Magnesium Diboride Superconducting Thin Films grown by Pulsed Laser Deposition

Superconducting thin films of MgB2 were deposited by Pulsed Laser Deposition on magnesium oxide and sapphire substrates. Samples grown at 450C in an argon buffer pressure of about 10-2 mbar by using a magnesium enriched target resulted to be superconducting with a transition temperature of about 25 K. Film deposited from a MgB2 sintered pellet target in ultra high vacuum conditions showed poor metallic or weak semiconducting behavior and they became superconducting only after an ex-situ annealing in Mg vapor atmosphere. Up to now, no difference in the superconducting properties of the films obtained by these two procedures has been evidenced.Comment: 10 pages, 4 figure

Under-nutrition Affects Time to Recurrence of Gastroenteritis Among Aboriginal and Non-Aboriginal Children

This study investigated whether under-nutrition affected time to hospitalization for recurrence of gastroenteritis in Australian children. Linked hospitalization records of all infants, born in 1995 and 1996 in Western Australia, who were admitted for gastroenteritis during their first year of life (n=1,001), were retrieved. A survival frailty model was used for determining the factors influencing the recurrent times over the subsequent seven years. Aboriginality and under-nutrition were significantly associated with an increased risk of recurrence (hazard ratios of 2.59 and 1.28). Hospitalizations due to gastroenteritis were common among Aboriginal children who had a higher mean re-admission rate and much shorter intervals between re-admissions than other patients. The proportion of patients with recurrence was also significantly higher for Aboriginals (38.5%) than for other patients (14.2%). Gastroenteritis remains a serious problem in Aboriginal children. This presents a complex challenge to be addressed with public-health principles, political determination and commitment, and adequate resources

Thermodynamic properties of binary HCP solution phases from special quasirandom structures

Three different special quasirandom structures (SQS) of the substitutional hcp $A_{1-x}B_x$ binary random solutions ($x=0.25$, 0.5, and 0.75) are presented. These structures are able to mimic the most important pair and multi-site correlation functions corresponding to perfectly random hcp solutions at those compositions. Due to the relatively small size of the generated structures, they can be used to calculate the properties of random hcp alloys via first-principles methods. The structures are relaxed in order to find their lowest energy configurations at each composition. In some cases, it was found that full relaxation resulted in complete loss of their parental symmetry as hcp so geometry optimizations in which no local relaxations are allowed were also performed. In general, the first-principles results for the seven binary systems (Cd-Mg, Mg-Zr, Al-Mg, Mo-Ru, Hf-Ti, Hf-Zr, and Ti-Zr) show good agreement with both formation enthalpy and lattice parameters measurements from experiments. It is concluded that the SQS's presented in this work can be widely used to study the behavior of random hcp solutions.Comment: 15 pages, 8 figure

Activation and Monitoring of mtDNA Damage in Cancer Cells via the "proton-Triggered" Decomposition of an Ultrathin Nanosheet

Mitochondrial DNA (mtDNA) damage is a very important molecular event, which has significant effects on living organisms. Therefore, a particularly important challenge for biomaterials research is to develop functionalized nanoparticles that can activate and monitor mtDNA damage and instigate cancer cell apoptosis, and as such eliminate the negative effects on living organisms. Toward that goal, with this research, we have developed a hydroxyapatite ultrathin nanosheet (HAP-PDCns) - a high Ca2+ content biomaterial. HAP-PDCns undergoes proton-triggered decomposition after entering cancer cells via clathrin-mediated endocytosis, and then, it selectively concentrates in the charged mitochondrial membrane. This kind of proton-triggered decomposition phenomenon facilitates mtDNA damage by causing instantaneous local calcium overload in the mitochondria of cancer cells, and inhibits tumor growth. Importantly, at the same time, a real-time green-red-green fluorescence change occurs that correlates with the degree of mtDNA deterioration because of the changes in the highest occupied molecular orbital-lowest unoccupied molecular orbital energy gaps during this process. Significantly, the decomposition and the fluorescence changes cannot be triggered in normal cells. Thus, HAP-PDCns can selectively induce apoptosis and the death of a cancer cell by facilitating mtDNA damage, but does not affect normal cells. In addition, HAP-PDCns can simultaneously monitor the degree of mtDNA damage. We anticipate that this design strategy can be generalized to develop other functionalized biomaterials that can be used to instigate the positive effects of mtDNA damage on living organisms while eliminating any negative effects. </p

Activation and Monitoring of mtDNA Damage in Cancer Cells via the "proton-Triggered" Decomposition of an Ultrathin Nanosheet

Mitochondrial DNA (mtDNA) damage is a very important molecular event, which has significant effects on living organisms. Therefore, a particularly important challenge for biomaterials research is to develop functionalized nanoparticles that can activate and monitor mtDNA damage and instigate cancer cell apoptosis, and as such eliminate the negative effects on living organisms. Toward that goal, with this research, we have developed a hydroxyapatite ultrathin nanosheet (HAP-PDCns) - a high Ca2+ content biomaterial. HAP-PDCns undergoes proton-triggered decomposition after entering cancer cells via clathrin-mediated endocytosis, and then, it selectively concentrates in the charged mitochondrial membrane. This kind of proton-triggered decomposition phenomenon facilitates mtDNA damage by causing instantaneous local calcium overload in the mitochondria of cancer cells, and inhibits tumor growth. Importantly, at the same time, a real-time green-red-green fluorescence change occurs that correlates with the degree of mtDNA deterioration because of the changes in the highest occupied molecular orbital-lowest unoccupied molecular orbital energy gaps during this process. Significantly, the decomposition and the fluorescence changes cannot be triggered in normal cells. Thus, HAP-PDCns can selectively induce apoptosis and the death of a cancer cell by facilitating mtDNA damage, but does not affect normal cells. In addition, HAP-PDCns can simultaneously monitor the degree of mtDNA damage. We anticipate that this design strategy can be generalized to develop other functionalized biomaterials that can be used to instigate the positive effects of mtDNA damage on living organisms while eliminating any negative effects. </p

Constraints on alternative models to dark energy

The recent observations of type Ia supernovae strongly support that the universe is accelerating now and decelerated in the recent past. This may be the evidence of the breakdown of the standard Friemann equation. We consider a general modified Friedmann equation. Three different models are analyzed in detail. The current supernovae data and the Wilkinson microwave anisotropy probe data are used to constrain these models. A detailed analysis of the transition from the deceleration phase to the acceleration phase is also performed.Comment: 10 pages, 1 figure, revtex

In situ epitaxial MgB2 thin films for superconducting electronics

A thin film technology compatible with multilayer device fabrication is critical for exploring the potential of the 39-K superconductor magnesium diboride for superconducting electronics. Using a Hybrid Physical-Chemical Vapor Deposition (HPCVD) process, it is shown that the high Mg vapor pressure necessary to keep the MgB$_2$ phase thermodynamically stable can be achieved for the {\it in situ} growth of MgB$_2$ thin films. The films grow epitaxially on (0001) sapphire and (0001) 4H-SiC substrates and show a bulk-like $T_c$ of 39 K, a $J_c$(4.2K) of $1.2 \times 10^7$ A/cm$^2$ in zero field, and a $H_{c2}(0)$ of 29.2 T in parallel magnetic field. The surface is smooth with a root-mean-square roughness of 2.5 nm for MgB$_2$ films on SiC. This deposition method opens tremendous opportunities for superconducting electronics using MgB$_2$

A Chinese Herbal Decoction, Danggui Buxue Tang, Stimulates Proliferation, Differentiation and Gene Expression of Cultured Osteosarcoma Cells: Genomic Approach to Reveal Specific Gene Activation

Danggui Buxue Tang (DBT), a Chinese herbal decoction used to treat ailments in women, contains Radix Astragali (Huangqi; RA) and Radix Angelicae Sinensis (Danggui; RAS). When DBT was applied onto cultured MG-63 cells, an increase of cell proliferation and differentiation of MG-63 cell were revealed: both of these effects were significantly higher in DBT than RA or RAS extract. To search for the biological markers that are specifically regulated by DBT, DNA microarray was used to reveal the gene expression profiling of DBT in MG-63 cells as compared to that of RA- or RAS-treated cells. Amongst 883 DBT-regulated genes, 403 of them are specifically regulated by DBT treatment, including CCL-2, CCL-7, CCL-8, and galectin-9. The signaling cascade of this DBT-regulated gene expression was also elucidated in cultured MG-63 cells. The current results reveal the potential usage of this herbal decoction in treating osteoporosis and suggest the uniqueness of Chinese herbal decoction that requires a well-defined formulation. The DBT-regulated genes in the culture could serve as biological responsive markers for quality assurance of the herbal preparation