We present for the first time the synthesis of Eu(3+)-doped ?-phase sodium gadolinium fluoride (NaGdF4:Eu) nanocrystals (NCs) using a hydrothermal method and the application of down conversion (DC) NaGdF4:Eu NCs to efficient dye-sensitized solar cells (DSSCs). The as-prepared NaGdF4:Eu(3+) NCs were characterized by X-ray diffraction, photoluminescence spectrometry, and scanning and transmission electron microscopy. DC layers consisting of poly(methyl methacrylate) (PMMA) doped with luminescent NaGdF4:Eu(3+) were prepared and attached onto the back of a prefabricated TiO2 anode to form a more efficient DSSC, compared with a device based on a pure TiO2 electrode. The influences of both doped and undoped NaGdF4 NC layers on the photovoltaic devices were compared and evaluated by the measurement of the device's incident-photon-to-current efficiency (IPCE). An obvious increase in IPCE was observed when the DC layer was added in the device. As the down-converted photons can be reabsorbed within DSSCs to generate photocurrent, the DSSC with a 100 nm thick NaGdF4:Eu(3+) DC-PMMA layer improved photoelectric conversion efficiency by 4.5% relative to the uncoated solar cell. The experiments conclude that NaGdF4:Eu(3+) nanocrystals mainly act as luminescent DC centers and light scatterers in the ultraviolet and visible domains, respectively, for enhancing the spectral response of the device in the measured spectral regime.
Synthetic genetic circuits are programmed in living cells to perform predetermined cellular functions. However, designing higher-order genetic circuits for sophisticated cellular activities remains a substantial challenge. Here we program a genetic circuit that executes Pavlovian-like conditioning, an archetypical sequential-logic function, in Escherichia coli. The circuit design is first specified by the subfunctions that are necessary for the single simultaneous conditioning, and is further genetically implemented using four function modules. During this process, quantitative analysis is applied to the optimization of the modules and fine-tuning of the interconnections. Analogous to classical Pavlovian conditioning, the resultant circuit enables the cells to respond to a certain stimulus only after a conditioning process. We show that, although the conditioning is digital in single cells, a dynamically progressive conditioning process emerges at the population level. This circuit, together with its rational design strategy, is a key step towards the implementation of more sophisticated cellular computing.
Patent ductus arteriosus (PDA) is one of the most common congenital heart defects. Transcription factor AP-2 beta (TFAP2B) mutations are associated with the Char syndrome, a disorder associated with PDA, and with facial and fingers abnormalities. Recently, we identified two TFAP2B mutations in two families without Char syndrome phenotype, c.601+5G>A and c.435_438delCCGG, and these TFAP2B mutations were associated with familial isolated PDA. The aim of this study was to identify the effects of these mutations on TFAP2B function.
The present paper describes a new method for manufacturing large scale, stable, transportable, and designable nanostructured porous TiO2 tapes on various substrates for use in photoelectrochemical cells. The method involves predeposition of TiO2 strips on the fluorine doped tin oxide (FTO) glass by screen-printing method, peeling off TiO2 strips from the substrate by a novel laser-assisted lift-off technique, sintering the formed TiO2 tapes at 500 °C for 15 min, and compressing the sintered TiO2 tapes on different conductive substrates with a low pressure rolling press to form mechanically stable, electrically conducting, porous nanostructured TiO2 electrodes at room temperature. Photoelectrochemical characteristics of the resulted electrodes are presented. Dye-sensitized solar cells (DSSCs) with the as-fabricated TiO2 photoanodes on PET-ITO and FTO glass achieved a conversion efficiency of 4.2% and 6.2%, respectively. The potential use of this new manufacturing method in future DSSC applications is discussed.
Objectives: The primary purposes of the present study were (1) to assess the living arrangements among urban Chinese elders, (2) to examine the relationship between household living arrangement and elders mental health, and (3) to investigate how individuals neighborhood identity affects their mental health. Method: The random sample was collected in 2011, including 939 respondents aged 60 and above who lived in the Jingan district of Shanghai, China. The study examined well-being and depression of elders. The domestic living arrangements were assessed by a single item with five options: With whom are you living together? The neighborhood identity was measured by four items: the sense of belonging, the sense of pride, volunteer work, and monetary donation for the neighborhood. Results: Urban Chinese elders living arrangement had transited from a traditional intergenerational co-residence pattern to a more self-independent style. However, living with children was positively associated with elders mental health after controlling for demographic variables. Although the neighborhood identity had no interaction with living arrangement, it also contributed to elders mental health. Conclusion: The study highlighted the importance of living with children and spouse, the sense of belonging, volunteer work, and the feelings of pride on elders mental health. Results of the current study suggested implications for both government and non-governmental organizations to design family-based support for eldercare and improve neighborhood identity for elders.
BACKGROUND/STUDY CONTEXT: The purpose of the current study was to investigate whether age was related to emotional labor strategies (surface and deep acting), and whether emotional intelligence partially explained this relationship. Additionally, employee well-being was examined as an outcome in this model.
The microRNA miR-101 has been reported to be a tumor suppressor. Here we show that low expression of miR-101 is associated with poor survival in stage IV melanoma patients. We identified microphthalmia-associated transcription factor (MITF) as a direct target of miR-101. In melanoma cells, overexpression of miR-101 downregulated protein levels of MITF and a previously reported target protein, enhancer of zeste homolog 2 (EZH2). Functional assays showed that miR-101 suppressed invasion and proliferation - an outcome that could be phenocopied by siRNA knockdown of MITF and EZH2. Our data suggest that miR-101 might have a beneficial role in melanoma.
We developed a single vector recombinant adeno-associated viral (rAAV) expression system for spatial and reversible control of polycistronic gene expression. Our approach (i) integrates the advantages of the tetracycline (Tet)-controlled transcriptional silencer tTS(Kid) and the self-cleaving 2A peptide bridge, (ii) combines essential regulatory components as an autoregulatory loop, (iii) simplifies the gene delivery scheme, and (iv) regulates multiple genes in a synchronized manner. Controlled by an upstream Tet-responsive element (TRE), both the ubiquitous chicken ?-actin promoter (CAG) and the neuron-specific synapsin-1 promoter (Syn) could regulate expression of tTS(Kid) together with two 2A-linked reporter genes. Transduction in vitro exhibited maximally 50-fold regulation by doxycycline (Dox). Determined by gene delivery method as well as promoter, highly specific tissues were transduced in vivo. Bioluminescence imaging (BLI) visualized reversible "ON/OFF" gene switches over repeated "Doxy-Cycling" in living mice. Thus, the reversible rAAV-mediated N-cistronic gene expression system, termed RANGE, may serve as a versatile tool to achieve reversible polycistronic gene regulation for the study of gene function as well as gene therapy.Molecular Therapy - Nucleic Acids (2013) 2, e85; doi:10.1038/mtna.2013.15; published online 9 April 2013.
The concept of microbial consortia is of great attractiveness in synthetic biology. Despite of all its benefits, however, there are still problems remaining for large-scaled multicellular gene circuits, for example, how to reliably design and distribute the circuits in microbial consortia with limited number of well-behaved genetic modules and wiring quorum-sensing molecules. To manage such problem, here we propose a formalized design process: (i) determine the basic logic units (AND, OR and NOT gates) based on mathematical and biological considerations; (ii) establish rules to search and distribute simplest logic design; (iii) assemble assigned basic logic units in each logic operating cell; and (iv) fine-tune the circuiting interface between logic operators. We in silico analyzed gene circuits with inputs ranging from two to four, comparing our method with the pre-existing ones. Results showed that this formalized design process is more feasible concerning numbers of cells required. Furthermore, as a proof of principle, an Escherichia coli consortium that performs XOR function, a typical complex computing operation, was designed. The construction and characterization of logic operators is independent of "wiring" and provides predictive information for fine-tuning. This formalized design process provides guidance for the design of microbial consortia that perform distributed biological computation.
In our recent study, we first reported that mutation in vascular endothelial growth factor-A is associated with bicuspid aortic valve stenosis. However, to date no groups have explored the role of vascular endothelial growth factor-A variations in the aetiology of congenital tricuspid aortic valve stenosis.
Our primary purpose in this study was to examine age differences in using choice deferral when young and older adults made trade-off decisions. Ninety-two young and 92 older adults were asked to make a trade-off decision among four cars or to use choice deferral (i.e., not buy any of these cars and keep looking for other cars). High and low emotional trade-off difficulty were manipulated between participants through different attribute labels of available cars. Older adults were more likely than young adults to choose deferral. Older adults who used deferral reported less retrospective negative emotion than those who did not.
The present study examined age and cultural differences in cognitive and affective components of subjective well-being. A sample of 188 American and Chinese young and older adults completed surveys measuring self-life satisfaction, perceived familys life satisfaction, positive affect, and negative affect. Across cultures, older adults reported lower negative affect than did young adults. Americans reported higher self-life satisfaction, perceived familys life satisfaction, and positive affect than did Chinese. In addition, perceived familys life satisfaction was more related to self-life satisfaction for Chinese than for Americans. Findings are discussed in light of socioemotional selectivity theory and theories on culture and self-construal.
Left ventricular outflow tract obstruction (LVOTO) comprises a spectrum of stenotic lesions. Previous studies have shown that the vascular endothelial growth factor (VEGF) signaling system plays a critical role in cardiac cushion formation, vasculogenesis, and angiogenesis. We hypothesize that VEGFA may be a potential candidate gene associated with the spectrum of LVOTO lesions. However, it remains unclear whether the VEGFA gene is responsible for the development of LVOTO malformations. In this study, we identified three exon mutations in the VEGFA gene in three of 192 nonsyndromic LVOTO patients, and the overall mutation frequency was 1.6% (3/192). The c.454C>T (p.Arg152X) nonsense mutation and c.19_22dupGACA (p.Thr8ArgfsX78) internal tandem duplication mutation each introduced a premature stop codon and are predicted to produce a truncated VEGFA protein. The c.998G>A missense mutation changes a highly conserved arginine to a glutamine at residue 333 (p.Arg333Gln). These mutations were carried by some family members, and average penetrance was 33.3%. The present study suggests, for the first time to our knowledge, that VEGFA mutations may be associated with congenital LVOTO malformations. We provide evidence that LVOTO is likely oligogenic.
Low cost and large scale carbon nanotube and nanofibre (CNT-CNF) composite films have been fabricated and employed as electrodes for electrosorption of cupric ions. The regeneration of the saturated CNT-CNF film electrode has been investigated. Three methods (short-circuiting, short-circuiting and then reversing voltage, reversing voltage and then short-circuiting) are used for regeneration. The results show that low regeneration efficiency of CNT-CNF film electrode due to electrodeposition of Cu on the electrode surface can be highly improved by regeneration applying reverse voltage combined with short circuit. 93% regeneration efficiency can be achieved when 0.8 V reverse voltage is applied before short-circuiting during regeneration of CNT-CNF film electrode.
The electron field emission performance of screen-printed graphene cathode was studied. High-yield graphene was prepared by a modified Hummers method and hydrazine hydrate reduction process, and screen printing technology was used to prepare the graphene field emission cathode. This cathode structure satisfies the requirements of both good electrical conductivity and a high surface field enhancement factor, leading to excellent and stable field emission properties with a low threshold field ( approximately 1.5 V microm(-1)). Our work introduced a simple and convenient method suitable for large scale on different substrates, paving the way for more applications of graphene films.
In this study, the hydroxyapatite (HAp) nanopowders prepared by chemical precipitation method were used as the adsorbent, and the potential of HAp nanopowders for phenol adsorption from aqueous solution was studied. The effect of contact time, initial phenol concentration, pH, adsorbent dosage, solution temperature and adsorbent calcining temperature on the phenol adsorption, and the adsorption kinetic, equilibrium and thermodynamic parameters were investigated. The results showed that the HAp nanopowders possessed good adsorption ability to phenol. The adsorption process was fast, and it reached equilibrium in 2h of contact. The initial phenol concentration, pH and the adsorbent calcining temperature played obvious effects on the phenol adsorption capacity onto HAp nanopowders. Increase in the initial phenol concentration could effectively increase the phenol adsorption capacity. At the same time, increase in the pH to high-acidity or to high-alkalinity also resulted in the increase in the phenol adsorption capacity. Increase in the HAp dosage could effectively increase the phenol adsorption percent. However, the higher calcining temperature of HAp nanopowders could obviously decrease the adsorption capacity. The maximum phenol adsorption capacity was obtained as 10.33mg/g for 400mg/L initial phenol concentrations at pH 6.4 and 60 degrees C. The adsorption kinetic and the isotherm studies showed that the pseudo-second-order model and the Freundlich isotherm were the best choices to describe the adsorption behaviors. The thermodynamic parameters suggested that the adsorption of phenol onto HAp was physisorption, spontaneous and endothermic in nature.
Coma and anisocoria are the two common signs of a crucial state of neurological dysfunction. The ability to forecast the occurrence of these conditions would help clinicians make clinical risk assessments and decisions.
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