316 research outputs found

    Improved characteristics of near-band-edge and deep-level emissions from ZnO nanorod arrays by atomic-layer-deposited Al2O3 and ZnO shell layers

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    We report on the characteristics of near-band-edge (NBE) emission and deep-level band from ZnO/Al2O3 and ZnO/ZnO core-shell nanorod arrays (NRAs). Vertically aligned ZnO NRAs were synthesized by an aqueous chemical method, and the Al2O3 and ZnO shell layers were prepared by the highly conformal atomic layer deposition technique. Photoluminescence measurements revealed that the deep-level band was suppressed and the NBE emission was significantly enhanced after the deposition of Al2O3 and ZnO shells, which are attributed to the decrease in oxygen interstitials at the surface and the reduction in surface band bending of ZnO core, respectively. The shift of deep-level emissions from the ZnO/ZnO core-shell NRAs was observed for the first time. Owing to the presence of the ZnO shell layer, the yellow band associated with the oxygen interstitials inside the ZnO core would be prevailed over by the green luminescence, which originates from the recombination of the electrons in the conduction band with the holes trapped by the oxygen vacancies in the ZnO shell

    Metabolic labelling of cholesteryl glucosides in Helicobacter pylori reveals how the uptake of human lipids enhances bacterial virulence.

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    Helicobacter pylori infects approximately half of the human population and is the main cause of various gastric diseases. This pathogen is auxotrophic for cholesterol, which it converts upon uptake to various cholesteryl Îą-glucoside derivatives, including cholesteryl 6'-acyl and 6'-phosphatidyl Îą-glucosides (CAGs and CPGs). Owing to a lack of sensitive analytical methods, it is not known if CAGs and CPGs play distinct physiological roles or how the acyl chain component affects function. Herein we established a metabolite-labelling method for characterising these derivatives qualitatively and quantitatively with a femtomolar detection limit. The development generated an MS/MS database of CGds, allowing for profiling of all the cholesterol-derived metabolites. The subsequent analysis led to the unprecedented information that these bacteria acquire phospholipids from the membrane of epithelial cells for CAG biosynthesis. The resulting increase in longer or/and unsaturated CAG acyl chains helps to promote lipid raft formation and thus delivery of the virulence factor CagA into the host cell, supporting the idea that the host/pathogen interplay enhances bacterial virulence. These findings demonstrate an important connection between the chain length of CAGs and the bacterial pathogenicity

    Reversine suppresses oral squamous cell carcinoma via cell cycle arrest and concomitantly apoptosis and autophagy

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    <p>Abstract</p> <p>Background</p> <p>The effective therapies for oral cancer patients of stage III and IV are generally surgical excision and radiation combined with adjuvant chemotherapy using 5-Fu and Cisplatin. However, the five-year survival rate is still less than 30% in Taiwan. Therefore, evaluation of effective drugs for oral cancer treatment is an important issue. Many studies indicated that aurora kinases (A, B and C) were potential targets for cancer therapies. Reversine was proved to be a novel aurora kinases inhibitor with lower toxicity recently. In this study, the potentiality for reversine as an anticancer agent in oral squamous cell carcinoma (OSCC) was evaluated.</p> <p>Methods</p> <p>Effects of reversine on cell growth, cell cycle progress, apoptosis, and autophagy were evaluated mainly by cell counting, flow cytometry, immunoblot, and immunofluorescence.</p> <p>Results</p> <p>The results demonstrated that reversine significantly suppressed the proliferation of two OSCC cell lines (OC2 and OCSL) and markedly rendered cell cycle arrest at G2/M stage. Reversine also induced cell death via both caspase-dependent and -independent apoptosis. In addition, reversine could inhibit Akt/mTORC1 signaling pathway, accounting for its ability to induce autophagy.</p> <p>Conclusions</p> <p>Taken together, reversine suppresses growth of OSCC via multiple mechanisms, which may be a unique advantage for developing novel therapeutic regimens for treatment of oral cancer in the future.</p

    Finding a Fair Land Dispute Settlement Mechanism Between Adat Law Community Vs. Investor

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    Land utilization for investment in local areas raises various land related problems that ends with conflicts within the community. A conflict that occurs, usually begins with the management of communal land “tanah ulayat” within the adat law community environment, and in this case, land utilization that is managed by the third party (investors). The basic problem is the difference of perception and expectations toward the company that exists in the land which is claimed by the community. Both parties have their own claim on the land based on each legal systems, in this situation adat law or local law faced with state law which is used by investors. So far, the Indonesian government has yet to have legal grounds in giving a directions for land dispute/conflict settlement mechanism. This paper attempts to give an input regarding a land dispute settlement mechanism that can be accepted for all disputing parties. The paper features critical analysis using legal pluralism approach towards related government policies and technical regulations in the ministerial level. These regulations, among others are, Minister of Agrarian Regulation No. 5 of 1999 on the Guidance for Dispute Settlement of Communal Land Rights, and Ministry of Agrarian and Spatial Affairs Regulation No. 9 of 2015 on Procedures of Appointment of Communal Land Rights for Adat Law Community and Communities Located in certain regions, also the draft of Law regarding Recognition and Protection of Adat Law Community

    Sequence variants of the aging gene CISD2 and the risk for Alzheimer's disease

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    Background/PurposeThe CISD2 gene has been related to life span control and mitochondrial dysfunction in animals. In addition, inhibition of mitochondrial enzymes due to an accumulation of beta-amyloid peptide has been related to Alzheimer's disease (AD). This study aimed to explore the association between sequence variants of the CISD2 gene and risk for AD, which has not been explored previously.MethodsThis was a case–control study involving a total of 276 patients with AD who were recruited from three teaching hospitals in Taiwan from 2007 to 2010; 460 controls were recruited from elderly individuals attending for health check-ups and volunteers in the hospital during the same period of time. All participants were aged 60 years or older. Two haplotype-tagging single nucleotide polymorphisms (htSNPs), rs223330 and rs223331, were selected from the CISD2 gene to test the association between their polymorphisms and the risk for dementia, and how ApoE ɛ4 status, sex, hypertension, and type 2 diabetes mellitus might modify this association.Resultsrs223330 variant carriage was not associated with risk for AD [TT versus CC: adjusted odds ratio (AOR) = 0.98, 95% confidence interval (CI) = 0.59–1.62; TC versus CC: AOR = 0.72, 95% CI = 0.47–1.11]. Similar findings were observed for rs223331 (AA versus TT: AOR = 1.12; AT versus TT: AOR = 0.99). In addition, hypertension significantly modified the association between rs223331 and risk for AD (p = 0.005).Three common haplotypes (with a frequency of 99.8%) were observed for CISD2. Common CISD2 haplotypes were not associated with the risk for AD.ConclusionOur findings suggested that CISD2 htSNPs are not associated with AD risk

    Local Magnetic Field Role in Star Formation

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    We highlight distinct and systematic observational features of magnetic field morphologies in polarized submm dust continuum. We illustrate this with specific examples and show statistical trends from a sample of 50 star-forming regions.Comment: 4 pages, 3 figures; to appear in the EAS Proceedings of the 6th Zermatt ISM Symposium "Conditions and Impact of Star Formation from Lab to Space", September 201

    Estimation of cell concentration using high-frequency ultrasonic backscattering

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    Abstract Cell concentration is a crucial quantity for both clinical diagnostic examinations and cell culture studies. However, typical modalities for cell concentration measurements are either time-consuming or not cost-effective. In the present study, cell concentration is estimated using high-frequency ultrasonic backscattering. Validation tests indicate that the proposed method can differentiate red blood cells (RBCs) of various hematocrits. A 50-MHz ultrasound system with appropriate sensitivity is utilized to estimate cell concentrations from a small volume of RBCs suspended in saline, with hematocrits ranging from 1.66 × 10 -4 to 10%, and fibroblasts, with concentrations ranging from 2 × 10 4 to 128 × 10 4 cells/mL. The backscatter strength and statistical distribution, characterized by the Nakagami parameter, are calculated from gated signals for quantitatively assessing the samples. Results show that the backscatter strength of RBCs linearly increases with increasing hematocrit level in the hematocrit range of 3 to 10%, which agrees well with results of previous studies. The backscatter strength of RBCS has an exponential relationship with the hematocrit level in the hematocrit range of 1.66 × 10 -4 to 3%. The corresponding Nakagami parameter is sensitive to electronic noise as long as the signal-to-noise ratio decreasing follows with the decrease of RBC hematocrits at the concentration lower than 0.85%. The backscatter strength of fibroblasts exponentially increases with increasing fibroblasts concentration, which is consistent with results obtained from typical optical density measurements. A linear relationship, with correlation coefficient of 0.99, between the results of ultrasonic backscattering and those of the optical density measurements is established. High-frequency ultrasonic backscattering can be applied to sensitively estimate the concentrations of small volumes of cells
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