657 research outputs found
An analytic model of tidal waves in the Yellow Sea
Co-oscillating tides in the Yellow Sea south of Shantung Peninsula are investigated analytically by a superposition of Kelvin and Poincaré waves. The Yellow Sea is approximated by a rectangular bay of uniform depth with an opening at the head, and a variable portion of tidal energy is allowed to penetrate through the opening. The analytical results basically agree with the available tidal charts. For the semi-diurnal tide the Poincaré waves play an important role throughout the whole basin of the Yellow Sea, but for the diurnal tide their influence is restricted to the vicinity of the bay head. The asymmetry of amphidromic system arises primarily due to a partial penetration of tidal energy through the opening at the bay head. A large tidal elevation in the Kyunggi Bay south of Ongjin Peninsula is due to the modifications of Kelvin and Poincaré waves at the Ongjin Peninsula
Geometric registration of images by similarity transformation using two reference points
A method for registering a first image to a second image using a similarity transformation. The each image includes a plurality of pixels. The first image pixels are mapped to a set of first image coordinates and the second image pixels are mapped to a set of second image coordinates. The first image coordinates of two reference points in the first image are determined. The second image coordinates of these reference points in the second image are determined. A Cartesian translation of the set of second image coordinates is performed such that the second image coordinates of the first reference point match its first image coordinates. A similarity transformation of the translated set of second image coordinates is performed. This transformation scales and rotates the second image coordinates about the first reference point such that the second image coordinates of the second reference point match its first image coordinates
Suppression of lung cancer in murine model: treated by combination of recombinant human endostsatin adenovirus with low-dose cisplatin
<p>Abstract</p> <p>Background</p> <p>The sustained growth of tumors necessitates neovascularization. As one of the potent endogenous vascular inhibitors, endostatin has been widely used in antiangiogenesis therapy for tumor. Cisplatin is normally administered in chemotherapy for lung cancer but accompanied with serious side effects. In the current study, we investigated a novel chemo-antiangiogenesis therapeutic strategy to both improve toxic effects on lung cancer cells and reduce damages to normal cells in the anti-tumor therapy.</p> <p>Methods</p> <p>In vitro, we transduced LLC cells with Ad-hEndo and collected supernatants. Western blotting analysis of the supernatants revealed expression of endostatin. In vivo, to fully investigate the suppression effect on murine lung cancer of the combination therapy, we injected recombinant human endostatin adenovirus intratumorally plus a low dose of cisplatin intraperitoneally routinely. The tumor volume and survival time were observed. Angiogenesis was apparently inhibited within the tumor tissues and on the alginate beads. Assessment of apoptotic cells by the TUNEL assay was conducted in the tumor tissues.</p> <p>Results</p> <p>The combination treatment significantly suppressed the tumor growth and prolonged survival time of the murine LLC tumor model. This anti-tumor activity was associated with decreased microvessel density and increased apoptotic index of tumor cells.</p> <p>Conclusion</p> <p>According to the results in this study, recombinant human endostatin adenovirus in combination with a low dose of cisplatin demonstrated apparent synergistic anti-tumor activity without marked toxicity. Thus, these observations may provide a rational alternative for lung cancer treatment.</p
Effect of the H1N1 Influenza Pandemic on the Incidence of Epidemic Keratoconjunctivitis and on Hygiene Behavior: A Cross-Sectional Study
Background: EKC is transmitted chiefly by direct hand contact. It is suspected that the 2009/2010 influenza pandemic influenced hand washing. This study aims to examine the relationship between the 2009/2010 H1N1 influenza pandemic and hygiene behavior. Methods: We compared the EKC prevalence trends before, during and after the 2009/2010 influenza pandemic by using a t-test comparison of EKC sentinel surveillance. Results: During the pre-pandemic period, the incidence of EKC increased from the 21st to the 44th week each year. However, during the pandemic period in 2009, there was no epidemic peak. In the post-pandemic period, the epidemic curve was similar to that in the pre-pandemic period. Compared to the pre-pandemic period, the total number of EKC patients during the pandemic period showed a decrease of 44.9 % (t value = 27.23, p = 0.002). Comparing the pre-pandemic and pandemic periods by age group, we found there to be a significant decrease in the number of EKC patients for all age groups (24.12#t value#27.23, all P,0.05). This finding was most evident in the teenage group (62%) compared to the other age groups (decreases of 29 to 44%). Conclusions: A continuing effort should be made to educate the public on basic infection prevention behaviors in th
Efficient Performance of Electrostatic Spray-Deposited TiO2 Blocking Layers in Dye-Sensitized Solar Cells after Swift Heavy Ion Beam Irradiation
A compact TiO2 layer (~1.1 μm) prepared by electrostatic spray deposition (ESD) and swift heavy ion beam (SHI) irradiation using oxygen ions onto a fluorinated tin oxide (FTO) conducting substrate showed enhancement of photovoltaic performance in dye-sensitized solar cells (DSSCs). The short circuit current density (Jsc = 12.2 mA cm-2) of DSSCs was found to increase significantly when an ESD technique was applied for fabrication of the TiO2 blocking layer, compared to a conventional spin-coated layer (Jsc = 8.9 mA cm-2). When SHI irradiation of oxygen ions of fluence 1 × 1013 ions/cm2 was carried out on the ESD TiO2, it was found that the energy conversion efficiency improved mainly due to the increase in open circuit voltage of DSSCs. This increased energy conversion efficiency seems to be associated with improved electronic energy transfer by increasing the densification of the blocking layer and improving the adhesion between the blocking layer and the FTO substrate. The adhesion results from instantaneous local melting of the TiO2 particles. An increase in the electron transport from the blocking layer may also retard the electron recombination process due to the oxidized species present in the electrolyte. These findings from novel treatments using ESD and SHI irradiation techniques may provide a new tool to improve the photovoltaic performance of DSSCs
Oxidation resistance of graphene-coated Cu and Cu/Ni alloy
The ability to protect refined metals from reactive environments is vital to
many industrial and academic applications. Current solutions, however,
typically introduce several negative effects, including increased thickness and
changes in the metal physical properties. In this paper, we demonstrate for the
first time the ability of graphene films grown by chemical vapor deposition to
protect the surface of the metallic growth substrates of Cu and Cu/Ni alloy
from air oxidation. SEM, Raman spectroscopy, and XPS studies show that the
metal surface is well protected from oxidation even after heating at 200
\degree C in air for up to 4 hours. Our work further shows that graphene
provides effective resistance against hydrogen peroxide. This protection method
offers significant advantages and can be used on any metal that catalyzes
graphene growth
Oxidized LDL Receptor 1 (OLR1) as a Possible Link between Obesity, Dyslipidemia and Cancer
Recent studies have linked expression of lectin-like ox-LDL receptor 1
(OLR1) to tumorigenesis. We analyzed microarray data from
Olr1 knockout (KO) and wild type (WT) mice for genes
involved in cellular transformation and evaluated effects of
OLR1 over-expression in normal mammary epithelial cells
(MCF10A) and breast cancer cells (HCC1143) in terms of gene expression,
migration, adhesion and transendothelial migration. Twenty-six out of 238 genes
were inhibited in tissues of OLR1 KO mice; the vast majority of OLR1 sensitive
genes contained NF-κB binding sites in their promoters. Further studies
revealed broad inhibition of NF-kB target genes outside of the
transformation-associated gene pool, with enrichment themes of defense response,
immune response, apoptosis, proliferation, and wound healing. Transcriptome of
Olr1 KO mice also revealed inhibition of de
novo lipogenesis, rate-limiting enzymes fatty acid synthase
(Fasn), stearoyl-CoA desaturase (Scd1) and
ELOVL family member 6 (Elovl6), as well as lipolytic
phospholipase A2 group IVB (Pla2g4b). In studies comparing
MCF10A and HCC1143, the latter displayed 60% higher OLR1
expression. Forced over-expression of OLR1 resulted in
upregulation of NF-κB (p65) and its target pro-oncogenes involved in
inhibition of apoptosis (BCL2, BCL2A1,
TNFAIP3) and regulation of cell cycle
(CCND2) in both cell lines. Basal expression of
FASN, SCD1 and PLA2G4B,
as well as lipogenesis transcription factors PPARA,
SREBF2 and CREM, was higher in HCC1143
cells. Over-expression of OLR1 in HCC1143 cells also enhanced
cell migration, without affecting their adherence to TNFα-activated
endothelium or transendothelial migration. On the other hand,
OLR1 neutralizing antibody inhibited both adhesion and
transmigration of untreated HCC1143 cells. We conclude that
OLR1 may act as an oncogene by activation of NF-kB target
genes responsible for proliferation, migration and inhibition of apoptosis and
de novo lipogenesis genes
Graphene Photonics and Optoelectronics
The richness of optical and electronic properties of graphene attracts
enormous interest. Graphene has high mobility and optical transparency, in
addition to flexibility, robustness and environmental stability. So far, the
main focus has been on fundamental physics and electronic devices. However, we
believe its true potential to be in photonics and optoelectronics, where the
combination of its unique optical and electronic properties can be fully
exploited, even in the absence of a bandgap, and the linear dispersion of the
Dirac electrons enables ultra-wide-band tunability. The rise of graphene in
photonics and optoelectronics is shown by several recent results, ranging from
solar cells and light emitting devices, to touch screens, photodetectors and
ultrafast lasers. Here we review the state of the art in this emerging field.Comment: Review Nature Photonics, in pres
Relationship between cyclooxygenase 8473T>C polymorphism and the risk of lung cancer: a case-control study
BACKGROUND: Cyclooxygenase-2 (COX-2) plays an important role in the development of lung cancer. DNA sequence variations in the COX-2 gene may lead to altered COX-2 production and/or activity, and so they cause inter-individual differences in the susceptibility to lung cancer. To test this hypothesis, we investigated the association between the 8473T>C polymorphism in the 3'-untranslated region of the COX-2 gene and the risk of lung cancer in a Korean population. METHODS: The COX-2 genotypes were determined using PCR-based primer-introduced restriction analysis in 582 lung cancer patients and in 582 healthy controls that were frequency-matched for age and gender. RESULTS: The distribution of the COX-2 8473T>C genotypes was not significantly different between the overall lung cancer cases and the controls. However, when the cases were categorized by the tumor histology, the combined 8473 TC + CC genotype was associated with a significantly decreased risk of adenocarcinoma as compared with the 8473 TT genotype (adjusted OR = 0.64; 95% CI = 0.46–0.90, P = 0.01). On the stratification analysis, the protective effect of the combined 8473 TC + CC genotype against adenocarcinoma was statistically significant in the males, older individuals and ever-smokers (adjusted OR = 0.59; 95% CI = 0.39–0.91, P = 0.02; adjusted OR = 0.55; 95% CI = 0.33–0.93, P = 0.03; and adjusted OR = 0.57; 95% CI = 0.37–0.87, P = 0.01, respectively). CONCLUSION: These findings suggest that the COX-2 8473T>C polymorphism could be used as a marker for the genetic susceptibility to adenocarcinoma of the lung
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