267 research outputs found

    Electro-optic coupling of wide wavelength range in linear chirped-periodically poled lithium niobate and its applications

    Get PDF
    We theoretically investigate the electro-optic coupling in an optical superlattice of linear chirped-periodically poled lithium niobate. It is found that the electro-optic coupling in such optical superlattice can work in a wide wavelength range. Some of examples, with bandwidths of 20, 40, 80, 120nm, are demonstrated. The way to determine the electric field for perfect conversion between o- and e-ray and the method using apodized crystals of tanh profile to reduce the ripples are shown. As one of its applications, one kind of broadband Solc-type bandpass filter in optical communication range is proposed. (C) 2010 Optical Society of Americ

    Fluorescent and magnetic dual-responsive coreshell imprinting microspheres strategy for recognition and detection of phycocyanin

    Get PDF
    Molecular imprinting as a versatile technology is emerging for diverse species in various fields; however protein imprinting faces several problems related to the size, structural complexity, conformational flexibility, and compatibility with solvents. Herein, by using phycocyanin as a model, with physiological significance and fluorescence characteristics, we developed a facile and highly efficient approach to obtain fluorescent and magnetic dual-responsive coreshell imprinting microspheres. Twostage miniemulsion polymerization was employed, based on surface immobilization of phycocyanin with aminolysis and aldehyde modification on superparamagnetic support particles. The dual-responsive imprinting microspheres exhibited high adsorption capacity of 10.53 mg g(-1), excellent binding selectivity toward phycocyanin with a high imprinting factor of 2.41, and good reproducibility with standard error within 10%. Furthermore, fast simple magnetic separation and sensitive fluorescent detection in a wide pH range was offered for phycocyanin, showing a good linearity within 0.01-1.0 mg L-1 (R-2 = 0.9970) and a favorable detectability up to 1.5 ng mL(-1). Consequently, the imprinting microspheres were successfully applied as sorbents for selective isolation of phycocyanin from protein mixtures and special imaging recognition. Taking advantages of dual-responsive polymers and surface imprinting, the developed strategy provides great application potentials for convenient, rapid targeting identification/enrichment and separation of proteins and thereby contributing to targeting drug delivery and protein research.Molecular imprinting as a versatile technology is emerging for diverse species in various fields; however protein imprinting faces several problems related to the size, structural complexity, conformational flexibility, and compatibility with solvents. Herein, by using phycocyanin as a model, with physiological significance and fluorescence characteristics, we developed a facile and highly efficient approach to obtain fluorescent and magnetic dual-responsive coreshell imprinting microspheres. Twostage miniemulsion polymerization was employed, based on surface immobilization of phycocyanin with aminolysis and aldehyde modification on superparamagnetic support particles. The dual-responsive imprinting microspheres exhibited high adsorption capacity of 10.53 mg g(-1), excellent binding selectivity toward phycocyanin with a high imprinting factor of 2.41, and good reproducibility with standard error within 10%. Furthermore, fast simple magnetic separation and sensitive fluorescent detection in a wide pH range was offered for phycocyanin, showing a good linearity within 0.01-1.0 mg L-1 (R-2 = 0.9970) and a favorable detectability up to 1.5 ng mL(-1). Consequently, the imprinting microspheres were successfully applied as sorbents for selective isolation of phycocyanin from protein mixtures and special imaging recognition. Taking advantages of dual-responsive polymers and surface imprinting, the developed strategy provides great application potentials for convenient, rapid targeting identification/enrichment and separation of proteins and thereby contributing to targeting drug delivery and protein research

    Quinoline Group Modified Carbon Nanotubes for the Detection of Zinc Ions

    Get PDF
    Carbon nanotubes (CNTs) were covalently modified by fluorescence ligand (glycine-N-8-quinolylamide) and formed a hybrid material which could be used as a selective probe for metal ions detection. The anchoring to the surface of the CNTs was carried out by the reaction between the precursor and the carboxyl groups available on the surface of the support. Fourier transform infrared spectroscopy (FTIR) and Thermogravimetric analysis (TGA) unambiguously proved the existence of covalent bonds between CNTs and functional ligands. Fluorescence characterization shows that the obtained organic–inorganic hybrid composite is highly selective and sensitive (0.2 μM) to Zn(II) detection

    Financial risk tolerance of Chinese American families

    Get PDF
    This chapter investigates the factors that affect financial risk tolerance of Chinese American households. Research on the economic well-being of Chinese American households is extremely limited. Few national datasets differentiate Chinese Americans from other race/ethnicity groups. For this study, a survey of Chinese American households residing in Midwestern states was conducted. The results showed that about 80.5 % of the sample households expressed a willingness to take at least some financial risks. Factors that have an impact on financial risk tolerance of Chinese American households included gender, non-financial assets, income, and investment time horizon. Chinese Americans represents a small but fast-growing population in the USA. More research should be done to better serve the financial needs of this group.Includes bibliographical references

    An Experimental Exploration of the QCD Phase Diagram: The Search for the Critical Point and the Onset of De-confinement

    Full text link
    The QCD phase diagram lies at the heart of what the RHIC Physics Program is all about. While RHIC has been operating very successfully at or close to its maximum energy for almost a decade, it has become clear that this collider can also be operated at lower energies down to 5 GeV without extensive upgrades. An exploration of the full region of beam energies available at the RHIC facility is imperative. The STAR detector, due to its large uniform acceptance and excellent particle identification capabilities, is uniquely positioned to carry out this program in depth and detail. The first exploratory beam energy scan (BES) run at RHIC took place in 2010 (Run 10), since several STAR upgrades, most importantly a full barrel Time of Flight detector, are now completed which add new capabilities important for the interesting physics at BES energies. In this document we discuss current proposed measurements, with estimations of the accuracy of the measurements given an assumed event count at each beam energy.Comment: 59 pages, 78 figure

    ACE2-Mediated Reduction of Oxidative Stress in the Central Nervous System Is Associated with Improvement of Autonomic Function

    Get PDF
    Oxidative stress in the central nervous system mediates the increase in sympathetic tone that precedes the development of hypertension. We hypothesized that by transforming Angiotensin-II (AngII) into Ang-(1–7), ACE2 might reduce AngII-mediated oxidative stress in the brain and prevent autonomic dysfunction. To test this hypothesis, a relationship between ACE2 and oxidative stress was first confirmed in a mouse neuroblastoma cell line (Neuro2A cells) treated with AngII and infected with Ad-hACE2. ACE2 overexpression resulted in a reduction of reactive oxygen species (ROS) formation. In vivo, ACE2 knockout (ACE2−/y) mice and non-transgenic (NT) littermates were infused with AngII (10 days) and infected with Ad-hACE2 in the paraventricular nucleus (PVN). Baseline blood pressure (BP), AngII and brain ROS levels were not different between young mice (12 weeks). However, cardiac sympathetic tone, brain NADPH oxidase and SOD activities were significantly increased in ACE2−/y. Post infusion, plasma and brain AngII levels were also significantly higher in ACE2−/y, although BP was similarly increased in both genotypes. ROS formation in the PVN and RVLM was significantly higher in ACE2−/y mice following AngII infusion. Similar phenotypes, i.e. increased oxidative stress, exacerbated dysautonomia and hypertension, were also observed on baseline in mature ACE2−/y mice (48 weeks). ACE2 gene therapy to the PVN reduced AngII-mediated increase in NADPH oxidase activity and normalized cardiac dysautonomia in ACE2−/y mice. Altogether, these data indicate that ACE2 gene deletion promotes age-dependent oxidative stress, autonomic dysfunction and hypertension, while PVN-targeted ACE2 gene therapy decreases ROS formation via NADPH oxidase inhibition and improves autonomic function. Accordingly, ACE2 could represent a new target for the treatment of hypertension-associated dysautonomia and oxidative stress

    Functional Analysis of General Odorant Binding Protein 2 from the Meadow Moth, Loxostege sticticalis L. (Lepidoptera: Pyralidae)

    Get PDF
    Odorant binding proteins play a crucial role in transporting semiochemicals across the sensillum lymph to olfactory receptors within the insect antennal sensilla. In this study, the general odorant binding protein 2 gene was cloned from the antennae of Loxostege sticticalis, using reverse transcription PCR and rapid amplification of cDNA ends. Recombinant LstiGOBP2 was expressed in Escherichia coli and purified by Ni ion affinity chromatography. Real-time PCR assays indicated that LstiGOBP2 mRNA is expressed mainly in adult antennae, with expression levels differing with developmental age. Ligand-binding experiments using N-phenyl-naphthylamine (1-NPN) as a fluorescent probe demonstrated that the LstiGOBP2 protein has binding affinity to a broad range of odorants. Most importantly, trans-11-tetradecen-1-yl acetate, the pheromone component of Loxostege sticticalis, and trans-2-hexenal and cis-3-hexen-1-ol, the most abundant plant volatiles in essential oils extracted from host plants, had high binding affinities to LstiGOBP2 and elicited strong electrophysiological responses from the antennae of adults

    What is the potential for bisexual men in China to act as a bridge of HIV transmission to the female population? Behavioural evidence from a systematic review and meta-analysis

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>HIV prevalence among men who have sex with men (MSM) in China has rapidly increased in recent years. It is suggested that MSM could be a potential bridge of HIV transmission to the general female population. We investigated the bisexual behaviour of MSM in China through systematic review and meta-analysis.</p> <p>Methods</p> <p>We conducted a systematic review and meta-analyses on published peer-reviewed Chinese and English literature during 2001-2010 according to the PRISMA guidelines. Marital status and sexual behavioural indicators of MSM were presented graphically using forest plots. The pooled effect rates with 95% confidence intervals were also calculated. Meta-regression analyses were performed to examine the factors associated with high heterogeneities across the studies.</p> <p>Results</p> <p>Forty-three eligible articles (11 in English and 32 in Chinese) were identified. Our results showed that 17.0% (95% CI: 15.1-19.1%) of MSM in China are currently married to a woman and 26.3% (95% CI: 23.6-29.1%) of MSM had female sexual partners in the last six months. The pooled estimates for condom use rate between MSM and female sex partners was 41.4% (95% CI: 35.5-47.5%) at the last sex act; and 25.6% (95% CI: 23.0-28.4%) in the last six months. The consistent condom use rates with regular, non-commercial, casual and commercial female sex partners in the last six months were 23.3% (95% CI: 11.25-42.1%), 39.0% (95% CI: 28.8-50.3%) and 55.8% (95% CI: 41.4-69.4%), respectively.</p> <p>Conclusions</p> <p>A substantial proportion of Chinese MSM is currently married or had sexual relations with a female in the past six months. In addition, low condom usage was common between married MSM and their wives, hence posing a higher risk of transmitting HIV. Harm-reduction programs targeting married MSM and their female partners are necessary to curb the further spread of HIV infection to the general female population.</p
    corecore