Comparative indoor and outdoor stability measurements of polymer based solar cells

We report comparative indoor and outdoor stability testing of organic solar cells based on a blend between a donor-acceptor polyfluorene copolymer and a fullerene derivative. The outdoor testing was conducted for a period over 12,000 hours in Sheffield, England, with a Ts80 lifetime determined in excess of 10,000 hours (420 days). Indoor lifetime testing was performed on solar cells using a solar simulator under a constant irradiance of 1000 W/m(2) for more than 650 hours. We show that under the conditions explored here, device degradation under the two sets of conditions is approximately dependent on the absorbed optical energy dose

Hedgehog Inhibition Promotes a Switch from Type II to Type I Cell Death Receptor Signaling in Cancer Cells

TRAIL is a promising therapeutic agent for human malignancies. TRAIL often requires mitochondrial dysfunction, referred to as the Type II death receptor pathway, to promote cytotoxicity. However, numerous malignant cells are TRAIL resistant due to inhibition of this mitochondrial pathway. Using cholangiocarcinoma cells as a model of TRAIL resistance, we found that Hedgehog signaling blockade sensitized these cancer cells to TRAIL cytotoxicity independent of mitochondrial dysfunction, referred to as Type I death receptor signaling. This switch in TRAIL requirement from Type II to Type I death receptor signaling was demonstrated by the lack of functional dependence on Bid/Bim and Bax/Bak, proapoptotic components of the mitochondrial pathway. Hedgehog signaling modulated expression of X-linked inhibitor of apoptosis (XIAP), which serves to repress the Type I death receptor pathway. siRNA targeted knockdown of XIAP mimics sensitization to mitochondria-independent TRAIL killing achieved by Hedgehog inhibition. Regulation of XIAP expression by Hedgehog signaling is mediated by the glioma-associated oncogene 2 (GLI2), a downstream transcription factor of Hedgehog. In conclusion, these data provide additional mechanisms modulating cell death by TRAIL and suggest Hedgehog inhibition as a therapeutic approach for TRAIL-resistant neoplasms

Inulinase production in a batch bioreactor using agroindustrial residues as the substrate: experimental data and modeling

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)The production of inulinase employing agroindustrial residues as the substrate is a good alternative to reduce production costs and to minimize the environmental impact of disposing these residues in the environment. This study focused on the use of a phenomenological model and an artificial neural network (ANN) to simulate the inulinase production during the batch cultivation of the yeast Kluyveromyces marxianus NRRL Y-7571, employing a medium containing agroindustrial residues such as molasses, corn steep liquor and yeast extract. It was concluded that due to the complexity of the medium composition it was rather difficult to use a phenomenological model with sufficient accuracy. For this reason, an alternative and more cost-effective methodology based on ANN was adopted. The predictive capacity of the ANN was superior to that of the phenomenological model, indicating that the neural network approach could be used as an alternative in the predictive modeling of complex batch cultivations.3218595Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)URI-Campus de ErechimFEA/UNICAMPCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Hybrid modeling of inulinase bio-production process

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)BACKGROUND: A potential application of inulinase in the food industry is the production of fructooligosaccharides (FOS) through transfructosilation of sucrose. Besides their ability to increase the shelf-life and flavor of many products, FOS have many interesting functional properties. The use of an industrial medium may represent a good, cost-effective alternative to produce inulinase, since the activity of the enzyme produced may be improved or at least remain the same compared with that obtained using a synthetic medium. Thus, inulinase production for use in FOS synthesis is of considerable scientific and technological appeal, as is the development of a reliable mathematical model of the process. This paper describes a hybrid neural network approach to model inulinase production in a batch bioreactor using agroindustrial residues as substrate. The hybrid modeling makes use of a series artificial neural network to estimate the kinetic parameters of the process and the mass balance as constitutive equations. RESULTS: The proposed model was shown to be capable of describing the complex behavior of inulinase production employing agroindustrial residues as substrate, so that the mathematical framework developed is a useful tool for simulation of this process. CONCLUSION: The hybrid neural network model developed was shown to be an interesting alternative to estimate model parameters since complete elucidation of the phenomena and mechanisms involved in the fermentation is not required owing to the black-box nature of the ANN used as parameter estimator. (C) 2010 Society of Chemical Industry854512519Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Phototherapy and resistance training prevent sarcopenia in ovariectomized rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The aim of this study was to histologically and biochemically analyze the effects of light-emitting diode therapy (LEDT) associated with resistance training to prevent sarcopenia in ovariectomized rats. Forty female Wistar rats (12 months old, 295-330 g) were bilaterally ovariectomized and divided into four groups (n = 10 per group): control-sedentary (C), resistance training (T), LEDT-sedentary (L), and LEDT plus resistance training (LT). Trained rats performed a 12-week water-jumping program (3 days per week) carrying a load equivalent to 50-80 % of their body mass strapped to their back. Depending on the group protocol, the LED device (850 nm, 100 mW, 120 J/cm(2), spot size 0.5 cm(2)) was used either as the only method or after the resistance training had been performed. The device was used in the single point contact mode (for 10 min). The irradiated region was the center of the greater trochanter of the right femur and the middle third of the rectus femoris muscle was subsequently analyzed histomorphometrically. Significant increases (p < 0.05) were noted for the muscle volume of the T (68.1 +/- 19.7 %), the L (74.1 +/- 5.1 %), and the LT (68.2 +/- 11.5 %) groups compared to the C group (60.4 +/- 5.5 %). There were also significant increases in the concentrations of IGF-1, IL-1, and TNF-alpha in the muscles of the treated groups (p < 0.05). Animals in the LT group showed a significant increase in IL-6 compared to T, L, and C groups (p < 0.05). These findings suggest that resistance training and LEDT can prevent sarcopenia in ovariectomized rats.28614671474Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Predicting the Spatial Impact of Planned Special Events

While it is widely acknowledged that Planned Special Events (PSEs), such as concerts, soccer games, etc., have a strong impact on road traffic, very few studies have quantitatively investigated this phenomenon. In this paper we present the preliminary results of a technique to quantify the impact of PSEs on traffic around the venue of the events. In particular, our goal was to automatically identify all those road segments around a venue that show a different traffic behavior on event days than on non-event days. To this aim, we defined a specific pipeline, including a K-Nearest Neighbor classifier, trained on traffic data of event and non-event days for each road, using the Dynamic Time Warp (DTW) as distance metric. The proposed solutions has been empirically evaluated on four PSE venues in Germany. Two of them hosted only soccer matches of the German First League, while the other two had mixed types of PSEs, including sport, concerts and other categories of events. Results are very positive for the soccer stadiums, while more research is needed for the venues hosting mixed types of PSEs

PCDTBT based solar cells: one year of operation under real-world conditions.

We present measurements of the outdoor stability of PCDTBT:PC71BM based bulk heterojunction organic solar cells for over the course of a year. We find that the devices undergo a burn-in process lasting 450 hours followed by a TS80 lifetime of up to 6200 hours. We conclude that in the most stable devices, the observed TS80 lifetime is limited by thermally-induced stress between the device layers, as well as materials degradation as a result of edge-ingress of water or moisture through the encapsulation