568 research outputs found
Zinc oxide nanoparticle-coated films: fabrication, characterization, and antibacterial properties
In this article, novel antibacterial PVC-based films coated with ZnO nanoparticles (NPs) were fabricated, characterized, and studied for their antibacterial properties. It was shown that the ZnO NPs were coated on the surface of the PVC films uniformly and that the coating process did not affect the size and shape of the NPs on the surface of PVC films. Films coated with concentrations of either 0.2 or 0.075Β g/L of ZnO NPs exhibited antibacterial activity against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria, but exhibited no antifungal activity against Aspergillus flavus and Penicillium citrinum. Smaller particles (100Β nm) exhibited more potent antibacterial activity than larger particles (1000Β nm). All ZnO-coated films maintained antibacterial activity after 30Β days in water
Structure of hadron resonances with a nearby zero of the amplitude
We discuss the relation between the analytic structure of the scattering
amplitude and the origin of an eigenstate represented by a pole of the
amplitude.If the eigenstate is not dynamically generated by the interaction in
the channel of interest, the residue of the pole vanishes in the zero coupling
limit. Based on the topological nature of the phase of the scattering
amplitude, we show that the pole must encounter with the
Castillejo-Dalitz-Dyson (CDD) zero in this limit. It is concluded that the
dynamical component of the eigenstate is small if a CDD zero exists near the
eigenstate pole. We show that the line shape of the resonance is distorted from
the Breit-Wigner form as an observable consequence of the nearby CDD zero.
Finally, studying the positions of poles and CDD zeros of the KbarN-piSigma
amplitude, we discuss the origin of the eigenstates in the Lambda(1405) region.Comment: 7 pages, 3 figures, v2: published versio
Advances in small lasers
M.T.H was supported by an Australian Research council Future Fellowship research grant for this work. M.C.G. is grateful to the Scottish Funding Council (via SUPA) for financial support.Small lasers have dimensions or modes sizes close to or smaller than the wavelength of emitted light. In recent years there has been significant progress towards reducing the size and improving the characteristics of these devices. This work has been led primarily by the innovative use of new materials and cavity designs. This Review summarizes some of the latest developments, particularly in metallic and plasmonic lasers, improvements in small dielectric lasers, and the emerging area of small bio-compatible or bio-derived lasers. We examine the different approaches employed to reduce size and how they result in significant differences in the final device, particularly between metal- and dielectric-cavity lasers. We also present potential applications for the various forms of small lasers, and indicate where further developments are required.PostprintPeer reviewe
Observation of a ppb mass threshoud enhancement in \psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) decay
The decay channel
is studied using a sample of events collected
by the BESIII experiment at BEPCII. A strong enhancement at threshold is
observed in the invariant mass spectrum. The enhancement can be fit
with an -wave Breit-Wigner resonance function with a resulting peak mass of
and a
narrow width that is at the 90% confidence level.
These results are consistent with published BESII results. These mass and width
values do not match with those of any known meson resonance.Comment: 5 pages, 3 figures, submitted to Chinese Physics
Low Level of Low-Density Lipoprotein Receptor-Related Protein 1 Predicts an Unfavorable Prognosis of Hepatocellular Carcinoma after Curative Resection
BACKGROUND: Low-density lipoprotein receptor-related protein 1 (LRP1) is a multifunctional receptor involved in receptor-mediated endocytosis and cell signaling. The aim of this study was to elucidate the expression and mechanism of LRP1 in hepatocellular carcinoma (HCC). METHODS: LRP1 expression in 4 HCC cell lines and 40 HCC samples was detected. After interruption of LRP1 expression in a HCC cell line either with specific lentiviral-mediated shRNA LRP1 or in the presence of the LRP1-specific chaperone, receptor-associated protein (RAP), the role of LRP1 in the migration and invasion of HCC cells was assessed in vivo and in vitro, and the expression of matrix metalloproteinase (MMP) 9 in cells and the bioactivity of MMP9 in the supernatant were assayed. The expression and prognostic value of LRP1 were investigated in 327 HCC specimens. RESULTS: Low LRP1 expression was associated with poor HCC prognosis, with low expression independently related to shortened overall survival and increased tumor recurrence rate. Expression of LRP1 in non-recurrent HCC samples was significantly higher than that in early recurrent samples. LRP1 expression in HCC cell lines was inversely correlated with their metastatic potential. After inhibition of LRP1, low-metastatic SMCC-7721 cells showed enhanced migration and invasion and increased expression and bioactivity of MMP9. Correlation analysis showed a negative correlation between LRP1 and MMP9 expression in HCC patients. The prognostic value of LRP1 expression was validated in the independent data set. CONCLUSIONS: LRP1 modulated the level of MMP9 and low level of LRP1 expression was associated with aggressiveness and invasiveness in HCCs. LRP1 offered a possible strategy for tumor molecular therapy
The Genome of Ganderma lucidum Provide Insights into Triterpense Biosynthesis and Wood Degradation
BACKGROUND: Ganoderma lucidum (Reishi or Ling Zhi) is one of the most famous Traditional Chinese Medicines and has been widely used in the treatment of various human diseases in Asia countries. It is also a fungus with strong wood degradation ability with potential in bioenergy production. However, genes, pathways and mechanisms of these functions are still unknown. METHODOLOGY/PRINCIPAL FINDINGS: The genome of G. lucidum was sequenced and assembled into a 39.9 megabases (Mb) draft genome, which encoded 12,080 protein-coding genes and βΌ83% of them were similar to public sequences. We performed comprehensive annotation for G. lucidum genes and made comparisons with genes in other fungi genomes. Genes in the biosynthesis of the main G. lucidum active ingredients, ganoderic acids (GAs), were characterized. Among the GAs synthases, we identified a fusion gene, the N and C terminal of which are homologous to two different enzymes. Moreover, the fusion gene was only found in basidiomycetes. As a white rot fungus with wood degradation ability, abundant carbohydrate-active enzymes and ligninolytic enzymes were identified in the G. lucidum genome and were compared with other fungi. CONCLUSIONS/SIGNIFICANCE: The genome sequence and well annotation of G. lucidum will provide new insights in function analyses including its medicinal mechanism. The characterization of genes in the triterpene biosynthesis and wood degradation will facilitate bio-engineering research in the production of its active ingredients and bioenergy
Metallothionein (MT) -I and MT-II Expression Are Induced and Cause Zinc Sequestration in the Liver after Brain Injury
Experiments with transgenic over-expressing, and null mutant mice have determined that metallothionein-I and -II (MT-I/II) are protective after brain injury. MT-I/II is primarily a zinc-binding protein and it is not known how it provides neuroprotection to the injured brain or where MT-I/II acts to have its effects. MT-I/II is often expressed in the liver under stressful conditions but to date, measurement of MT-I/II expression after brain injury has focused primarily on the injured brain itself. In the present study we measured MT-I/II expression in the liver of mice after cryolesion brain injury by quantitative reverse-transcriptase PCR (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) with the UC1MT antibody. Displacement curves constructed using MT-I/II knockout (MT-I/IIβ/β) mouse tissues were used to validate the ELISA. Hepatic MT-I and MT-II mRNA levels were significantly increased within 24 hours of brain injury but hepatic MT-I/II protein levels were not significantly increased until 3 days post injury (DPI) and were maximal at the end of the experimental period, 7 DPI. Hepatic zinc content was measured by atomic absorption spectroscopy and was found to decrease at 1 and 3 DPI but returned to normal by 7DPI. Zinc in the livers of MT-I/IIβ/β mice did not show a return to normal at 7 DPI which suggests that after brain injury, MT-I/II is responsible for sequestering elevated levels of zinc to the liver. Conclusion: MT-I/II is up-regulated in the liver after brain injury and modulates the amount of zinc that is sequestered to the liver
Identification of Novel Human Damage Response Proteins Targeted through Yeast Orthology
Studies in Saccharomyces cerevisiae show that many proteins influence cellular survival upon exposure to DNA damaging agents. We hypothesized that human orthologs of these S. cerevisiae proteins would also be required for cellular survival after treatment with DNA damaging agents. For this purpose, human homologs of S. cerevisiae proteins were identified and mapped onto the human protein-protein interaction network. The resulting human network was highly modular and a series of selection rules were implemented to identify 45 candidates for human toxicity-modulating proteins. The corresponding transcripts were targeted by RNA interference in human cells. The cell lines with depleted target expression were challenged with three DNA damaging agents: the alkylating agents MMS and 4-NQO, and the oxidizing agent t-BuOOH. A comparison of the survival revealed that the majority (74%) of proteins conferred either sensitivity or resistance. The identified human toxicity-modulating proteins represent a variety of biological functions: autophagy, chromatin modifications, RNA and protein metabolism, and telomere maintenance. Further studies revealed that MMS-induced autophagy increase the survival of cells treated with DNA damaging agents. In summary, we show that damage recovery proteins in humans can be identified through homology to S. cerevisiae and that many of the same pathways are represented among the toxicity modulators
Identification of QTLs for Arsenic Accumulation in Maize (Zea mays L.) Using a RIL Population
The Arsenic (As) concentration in different tissues of maize was analyzed using a set of RIL populations derived from an elite hybrid, Nongda108. The results showed that the trend of As concentration in the four measured tissues was leaves>stems>bracts>kernels. Eleven QTLs for As concentration were detected in the four tissues. Three QTLs for As concentration in leaves were mapped on chromosomes 1, 5, and 8, respectively. For As concentration in the bracts, two QTLs were identified, with 9.61% and 10.03% phenotypic variance. For As concentration in the stems, three QTLs were detected with 8.24%, 14.86%, and 15.23% phenotypic variance. Three QTLs were identified for kernels on chromosomes 3, 5, and 7, respectively, with 10.73%, 8.52%, and 9.10% phenotypic variance. Only one common chromosomal region between SSR marker bnlg1811 and umc1243 was detected for QTLs qLAV1 and qSAC1. The results implied that the As accumulation in different tissues in maize was controlled by different molecular mechanism. The study demonstrated that maize could be a useful plant for phytoremediation of As-contaminated paddy soil, and the QTLs will be useful for selecting inbred lines and hybrids with low As concentration in their kernels
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