Growth and characterization of ceria thin films and Ce-doped γ-Al2O3 nanowires using sol-gel techniques

γ-Al(2)O(3) is a well known catalyst support. The addition of Ce to γ-Al(2)O(3) is known to beneficially retard the phase transformation of γ-Al(2)O(3) to α-Al(2)O(3) and stabilize the γ-pore structure. In this work, Ce-doped γ-Al(2)O(3) nanowires have been prepared by a novel method employing an anodic aluminium oxide (AAO) template in a 0.01 M cerium nitrate solution, assisted by urea hydrolysis. Calcination at 500 °C for 6 h resulted in the crystallization of the Ce-doped AlOOH gel to form Ce-doped γ-Al(2)O(3) nanowires. Ce(3+) ions within the nanowires were present at a concentration of < 1 at.%. On the template surface, a nanocrystalline CeO(2) thin film was deposited with a cubic fluorite structure and a crystallite size of 6-7 nm. Characterization of the nanowires and thin films was performed using scanning electron microscopy, transmission electron microscopy, electron energy loss spectroscopy, x-ray photoelectron spectroscopy and x-ray diffraction. The nanowire formation mechanism and urea hydrolysis kinetics are discussed in terms of the pH evolution during the reaction. The Ce-doped γ-Al(2)O(3) nanowires are likely to find useful applications in catalysis and this novel method can be exploited further for doping alumina nanowires with other rare earth elements.

Analysis of phthalate migration from plastic containers to packaged cooking oil and mineral water

The migration of phthalates (PAEs), a class of typical environmental estrogen contaminants in food, from food packaging to packaged food attracts more and more attention worldwide. Many factors will affect the migration processes. The purpose of this study was to evaluate PAE migration from plastic containers to cooking oil and mineral water packed in authentic commercial packaging and stored under various conditions (different storage temperatures, contact times, and storage states (static or dynamic state)) and to identify a potential relationship between the amount and type of PAEs migrated and the lipophilic character of the food matrix. The samples were analyzed by a novel method of liquid chromatography combined with solid-phase extraction by an electrospun nylon 6 nanofibers mat, with PAE detection limits of 0.001 μg/L in mineral water and 0.020 μg/L in cooking oil, respectively. The results demonstrated that the cooking oil was a more suitable medium for the migration of PAEs from packages into foodstuffs than mineral water. Scilicet, the migration potential of the PAEs into foodstuffs, depends on the lipophilic characteristics of the food matrix. The results also demonstrated that migrations were more significant at higher temperature, longer contact time, and higher dynamic frequency; thus, the migration tests should be evaluated with consideration of different storage temperatures and contact times. Mathematical models with good logarithmic relationships were established to demonstrate the relationship between the PAE migration and food/packaging contact time for different storage temperatures. These established mathematical models would be expected to become a set of practical tools for the prediction of PAE migration.

High-quality substrate for fluorescence enhancement using agarose-coated silica opal film

To improve the sensitivity of fluorescence detection in biochip, a new kind of substrates was developed by agarose coating on silica opal film. In this study, silica opal film was fabricated on glass substrate using the vertical deposition technique. It can provide stronger fluorescence signals and thus improve the detection sensitivity. After coating with agarose, the hybrid film could provide a 3D support for immobilizing sample. Comparing with agarose-coated glass substrate, the agarose-coated opal substrates could selectively enhance particular fluorescence signals with high sensitivity when the stop band of the silica opal film in the agarose-coated opal substrate overlapped the fluorescence emission wavelength. A DNA hybridization experiment demonstrated that fluorescence intensity of special type of agarose-coated opal substrates was about four times that of agarose-coated glass substrate. These results indicate that the optimized agarose-coated opal substrate can be used for improving the sensitivity of fluorescence detection with high quality and selectivity.

Transplantation of umbilical cord mesenchymal stem cells alleviates lupus nephritis in MRL/lpr mice

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease, which, despite the advances in immunosuppressive medical therapies, remains potentially fatal in some patients, especially in treatment-refractory patients. This study found that transplantation of umbilical cord mesenchymal stem cells (UC-MSCs) has the same therapeutic effect as transplantation of bone marrow mesenchymal stem cells (BM-MSCs), which has been reported to be efficient in treating SLE-related symptoms in MRL/lpr mice. Multi-treatment (at the 18th, 19th, and 20th weeks of age) of 1 × 10(6) UC-MSCs was able to decrease the levels of 24-h proteinuria, serum creatinine, and anti-double-stranded DNA (dsDNA) antibody, and the extent of renal injury such as crescent formation in MRL/lpr mice. A lower, but still significant, reduction in these parameters was also observed in mice receiving a single dose of UC-MSCs (at the 18th week). UC-MSCs treatment also inhibited expression of monocyte chemotactic protein-1 (MCP-1) and high-mobility group box 1 (HMGB-1) expression in a similar fashion. UC-MSCs labeled with carboxyfluorescein diacetate succinimidyl ester (CFSE) were found in the lungs and kidneys 1 week post infusion. In addition, after 11 weeks post UC-MSCs infusion, human cells were found in kidney of UC-MSCs-treated mice. These findings indicated that UC-MSCs transplantation might be a potentially promising approach in the treatment of lupus nephritis, possibly by inhibiting MCP-1 and HMGB-1 production.

Rapid and sensitive biomolecular screening with encoded macroporous hydrogel photonic beads

We present a new method to prepare inverse opaline photonic beads with good spherical shape and superior optical performance by simply introducing an interfacial tension system into a template replication method. When the scaffolds of these beads were composed of poly(ethylene glycol) diacrylate hydrogel, they could provide a homogeneous water surrounding, which remedied many shortcomings of biomolecular microcarriers introduced by the presence of the solid surface of them. The suspension array, which used these macroporous hydrogel photonic beads as coding elements, showed obvious advantages in multiplexed capability, rapid biomolecular screening (within 12 min), and highly sensitive detection (with limit of detection of approximately 10(-12) M).

Sintering photonic beads for multiplex biosensing

Monodispersed silica nanoparticles were assembled into opaline photonic crystal beads and cemented together by sintering in order to enhance the mechanical stability of the beads, which simulates the formation of nature opal. The sintering temperatures and structures of the sintered beads were investigated. The results showed that by sintering treatment at temperatures between 700 degrees C and 1000 degrees C for 2 hours the beads were more reliable for multiplex bioassay applications in mechanical robustness, fluorescent background, sensitivity and encoding ability. It is anticipated that the opal-like beads have wide applications in multiplex protein and nucleic acid analysis.

Degradation of microcystin-RR using boron-doped diamond electrode

Microcystins (MCs), produced by blue-green algae, are one of the most common naturally occurring toxins found in natural environment. The presence of MCs in drinking water sources poses a great threat to people's health. In this study, the degradation behavior of microcystin-RR on boron-doped diamond (BDD) electrode was investigated under galvanostatic conditions. Such parameters as reaction time, supporting electrolyte and applied current density were varied in order to determine their effects on this oxidation process. The experimental results revealed the suitability of electrochemical processes employing BDD electrode for removing MC-RR from the solution. However, the efficient removal of MC-RR only occurred in the presence of sodium chloride that acted as redox mediators and the reaction was mainly affected by the chloride concentration (c(NaCl)) and applied current density (I(appl)). Full and quick removal of 0.50 microg/ml MC-RR in solution was achieved when the operating conditions of c(NaCl) and I(appl) were 20mM and 46.3 mA/cm(2), or 35 mM and 18.2 mA/cm(2) respectively. The kinetics for MC-RR degradation followed a pesudo-first order reaction in most cases, indicating the process was under mass transfer control. As a result of its excellent performance, the BDD technology could be considered as a promising alternative to promote the degradation of MC-RR than chlorination in drinking water supplies.

Multiplex chemiluminescent immunoassay based on silica colloidal crystal beads

The paper presented a novel multiplex chemiluminescence (CL) immunoassay method, which was based on silica colloidal crystals beads (SCCBs) as carriers using enhanced chemiluminescence (CL) detection of a horseradish peroxidase (HRP) catalyzing the luminal reaction. The monodisperse and size-controlled SCCBs were fabricated by a microfluidic device. The experimental conditions were optimized and analytical performance was studied. Results showed that the SCCBs as supports were much sensitive (0.05 ng/ml IgG) than the glass beads (18 ng/ml IgG) and the planar carriers (125 ng/ml IgG). A multiplex immunoassay suggested the feasibility of high throughput applications. This novel immunoassay system provided a simple, sensitive and low-cost approach for multianalyte immunoassay without using of expensive array detector.

Detecting positive selection in the budding yeast genome

Available abundant genomic data allows us to study the evolution of the yeast genome at a fine scale. In this study, we examined the adaptive evolution of coding and promoter regions in three Saccharomyces cerevisiae strains. First, using a maximum-likelihood approach, we identified 76 positively selected genes (PSG) whose coding regions likely have undergone positive selection in the recent past. These genes show significant bias in terms of biological function and they show over-representation of charged amino acids at positively selected sites. Next, using recent data on yeast transcription-start sites to define core-promoter regions, we identified 31 positively selected promoters, and their corresponding genes are significantly enriched in transmembrane transporter function. We found PSG show no correlation with promoter adaption or expression variation, suggesting that positive selection on coding regions and positive selection on promoter regions are not coupled. Together, our study provides insights into the evolution of S. cerevisiae strains from different environments.

Growth of outgrowth endothelial cells on aligned PLLA nanofibrous scaffolds

Tissue engineering holds great promise in providing vascular grafts as substitutes for damaged small-diameter blood vessels. Two of the key factors in vascular tissue engineering are biocompatible scaffolds that mimic the effects of extracellular matrix and the source of seeding cells. Synthetic poly-L-lactic acid (PLLA) nanofibers has been shown to be excellent scaffolds for tissue engineering. Outgrowth endothelial cells (OECs) isolated from human peripheral blood could also be expanded in vitro and stably maintain the differentiated phenotypes and could be used as the seeding cells for engineering autologous vascular crafts. Here we tested the possibility of combining these two together. We found that PLLA nanofibers are not only biocompatible with OECs originally isolated from rabbit peripheral blood, the aligned PLLA fibers actually promoted and guided their sustained proliferation. These results suggest that aligned PLLA could be excellent both as the scaffolds and as a promoter of cell growth during vascular tissue engineering.

Impact of hypertension on health-related quality of life in a population-based study in Shanghai, China

OBJECTIVES

The purpose of this study was to examine the relationship between hypertension and health-related quality of life (HRQL) in a general representative Chinese population, and to explore the impacts of comorbidity on people with hypertension.

STUDY DESIGN

Population-based cross-sectional survey.

METHODS

A self-administered questionnaire survey including demographic questions and the Mandarin version of 36-item Short Form (SF-36) was conducted in a general population in Shanghai, China. In total, 1034 subjects participated. The SF-36 dimension scores of hypertensive subjects were compared with those of normotensive subjects. Independent association of hypertension with each quality-of-life domain was analysed using a multiple linear regression model, so were the effects of comorbidity on the HRQL of hypertensive subjects.

RESULTS

Nine hundred and nineteen respondents were included in the analysis, and 16.97% reported hypertension. Respondents with hypertension scored lower than those without hypertension in at least five SF-36 dimensions. The dimension of role limitations due to physical problems was the most affected, whereas the mental health dimension was the least affected. Hypertensive subjects with comorbidity experienced lower SF-36 scores than hypertensive subjects without comorbidity.

CONCLUSIONS

Hypertension markedly impairs quality of life in terms of both physical and mental health. Comorbidity further deteriorates HRQL among people with hypertension. The findings suggest that people with hypertension represent a vulnerable population, and it is important to prevent and treat comorbidity of hypertension.

Growth hormone stimulation of serum insulin concentration in cattle: nutritional dependency and potential mechanisms

Previous studies on the effect of growth hormone (GH) on serum insulin concentration in cattle had generated seemingly conflicting results, and little was known about the mechanism by which GH affects serum insulin concentration in cattle, if it does. In this study, we determined whether the effect of GH on serum insulin concentration in cattle could be affected by the nutritional levels of the animal and whether GH increased serum insulin concentration in cattle by directly stimulating insulin release or insulin gene expression in the pancreatic islets. Administration of recombinant bovine GH increased serum insulin concentration in nonlactating, nonpregnant beef cows fed a daily concentrate meal in addition to ad libitum hay, but it had no effect in those cows fed hay only. Both GH treatments for 1 and 24h increased insulin concentrations in cultures of pancreatic islets isolated from growing cattle. Growth hormone treatment for 24h increased insulin mRNA expression in cultured bovine pancreatic islets. Growth hormone treatment for 16h increased reporter gene expression directed by a approximately 1,500-bp bovine insulin gene promoter in a rat insulin-producing beta cell line. Taken together, these results suggest that exogenous GH can increase serum insulin concentration in cattle, but this effect depends on the nutritional levels of fed cattle, and that GH increases serum insulin concentration in cattle by stimulating both insulin release and insulin gene expression in the pancreatic islets.

Identification and characterization of the bovine G protein-coupled receptor GPR41 and GPR43 genes

Volatile fatty acids (VFA), including acetate, propionate, and butyrate, are not only a primary source of energy, but also regulate rumen development, insulin and glucagon secretion, and other physiological processes in cattle and sheep. The mechanism underlying the regulatory effects of VFA is unknown. Recent "reverse pharmacology" studies identified human G protein-coupled receptors GPR41 and GPR43 as receptors for short-chain fatty acids. It is possible that proteins similar to human GPR41 and GPR43 mediate the regulatory effects of VFA in cattle. In this study, we determined first, whether the bovine genome contains genes similar to the human GPR41 and GPR43 genes; second, whether and where these genes are expressed in cattle; and third, if the proteins encoded by these genes can be activated by acetate, propionate, and butyrate. A search of GenBank revealed bovine genomic sequences and expressed sequence tags highly similar to the human GPR41 and GPR43 DNA and cDNA sequences. The protein-coding and 5' untranslated regions of the bovine GPR41 and GPR43 mRNA were cloned and sequenced from spleen tissue. Based on these sequences, the bovine GPR41 gene contains 3 exons and its transcription is initiated at 2 leader exons, generating 2 GPR41 mRNA variants differing in the 5' untranslated region. The bovine GPR43 gene contains 2 exons and transcription of this gene is initiated from a single start site. The amino acid sequences deduced from the bovine GPR41 and GPR43 mRNA sequences are more than 75% identical to those of the human GPR41 and GPR43 and are predicted to encode 7 transmembrane domains, typical of G protein-coupled receptors. Both bovine GPR41 and GPR43 mRNA were detected in a variety of tissues including rumen and pancreas. In a cell system, interaction of the overexpressed bovine GPR41 or GPR43 protein with acetate, propionate, or butyrate inhibited luciferase reporter expression from a cyclic AMP-responsive promoter, suggesting that the bovine GPR41 and GPR43 proteins couple to Galpha(i/11). In total, these results demonstrate that the bovine genome encodes functional GPR41 and GPR43 genes and suggest that GPR41 and GPR43 may play a role in the regulatory effects of VFA in cattle.

Colloidal crystal beads composed of core-shell particles for multiplex bioassay

A convenient method was developed to fabricate colloidal crystal beads (CCBs) with tough mechanical strength, which was used as encoded carriers for multiplex bioassay. The latex particles used for the construction of the CCBs were designed with a rigid core PS and a elastomeric shell poly(MMA/EA/MAA), and were prepared via one-step soap-free emulsion polymerization. The as-above-prepared CCBs were thermo-treated to drive the elastomeric shells of adjacent latex particles joining together. It was found that the coalescence of latex particles can greatly improve the mechanical strength of the CCBs for multiplex bioassay.

Application of the blending of PNIPAM-co-PS nanofibers with functionalized Au nanoparticles for the high-sensitive diagnosis of cancer cells

The blending of poly(N-isopropylacrylamide)-co-polystyrene nanofibers with functionalized gold nanoparticles was explored to form the new nanocomposites to facilitate the accumulation of daunorubicin inside leukemia cells and potentially enhance the cure efficiency. The synergistic enhancement effect of the nanocomposites on the drug uptake of daunorubicin in drug resistant leukemia K562 cells has been observed by using electrochemical and confocal fluorescence microscopy studies. The results suggest that these nanocomposites could be utilized to facilitate the drug delivery and realization of the early diagnosis of the respective cancer cells, suggesting the potential valuable application in the relative biomedical and bioanalysis areas.