1,702 research outputs found

    High capacity cathode materials for Li-S batteries

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    To enhance the stability of sulfur cathode for a high energy lithium-sulfur battery, sulfur-activated carbon (S-AC) composite was prepared by encapsulating sulfur into micropores of activated carbon using a solution-based processing technique. In the analysis using the prepared specimen of S-AC composite by the focused ion beam (FIB) technique, the elemental sulfur exists in a highly dispersed state inside the micropores of activated carbon, which has a large surface area and a narrow pore distribution. The S-AC composite was characterized through X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) method, selected area electron diffraction (SAED), energy dispersive X-ray spectrometry (EDX), Fourier transform infrared spectroscopy (FT-IR), thermogravimetry analysis (TGA), and field emission scanning electron microscopy (FESEM). A lithium-sulfur cell using the S-AC composite has a high first discharge capacity over 800 mA h g -1 S even at a high current density such as 2C (3200 mA g -1 S) and has good cycleability around 500 mA h g-1 S discharge capacity at the 50th cycle at the same current density. © 2013 The Royal Society of Chemistry

    Asian Society of Gynecologic Oncology International Workshop 2014

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    MicroRNA-375 plays a dual role in prostate carcinogenesis

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    Background: Prostate cancer (PCa), a highly incident and heterogeneous malignancy, mostly affects men from developed countries. Increased knowledge of the biological mechanisms underlying PCa onset and progression are critical for improved clinical management. MicroRNAs (miRNAs) deregulation is common in human cancers, and understanding how it impacts in PCa is of major importance. MiRNAs are mostly downregulated in cancer, although some are overexpressed, playing a critical role in tumor initiation and progression. We aimed to identify miRNAs overexpressed in PCa and subsequently determine its impact in tumorigenesis. Results: MicroRNA expression profiling in primary PCa and morphological normal prostate (MNPT) tissues identified 17 miRNAs significantly overexpressed in PCa. Expression of three miRNAs, not previously associated with PCa, was subsequently assessed in large independent sets of primary tumors, in which miR-182 and miR-375 were validated, but not miR-32. Significantly higher expression levels of miR-375 were depicted in patients with higher Gleason score and more advanced pathological stage, aswellaswithregionallymph nodesmetastases. Forced expression of miR-375 in PC-3 cells, which display the lowest miR-375 levels among PCa cell lines, increased apoptosis and reduced invasion ability and cell viability. Intriguingly, in 22Rv1 cells, which displayed the highest miR-375 expression, knockdown experiments also attenuated the malignant phenotype. Gene ontology analysis implicated miR-375 in several key pathways deregulated in PCa, including cell cycle and cell differentiation. Moreover, CCND2 was identified as putative miR-375 target in PCa, confirmed by luciferase assay. Conclusions: A dual role for miR-375 in prostate cancer progression is suggested, highlighting the importance of cellular context on microRNA targeting.Research Center of Portuguese Oncology Institute - Porto (CI-IPOP 4–2012) and by the Federal funds through Programa Operacional Temático Factores de Competitividade (COMPETE) with co-participation from the European Community Fund (FEDER) and by the National funds through Fundação para a Ciência e Tecnología (FCT) under the projects EXPL/BIM-ONC/0556/2012. FQV and JRC were or are supported by FCT-Fundação para a Ciência e a Tecnologia grants (SFRH/BD/70564/2010 and SFRH/BD/71293/2010, respectively)

    A 10 year follow-up study after Roux-Elmslie-Trillat treatment for cases of patellar instability

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    <p>Abstract</p> <p>Background</p> <p>A retrospective study concerning patients presenting with patella instability, treated using a Roux-Elmslie-Trillat reconstruction operation and followed up for 10 years following surgery, is presented.</p> <p>Methods</p> <p>Pre-operative and follow-up radiographic evaluation included the weight-bearing anteroposterior and merchant views. Evaluation was carried out using the Insall-Salvati index, sulcus and congruence angle. The Roux-Elmslie-Trillat reconstruction operation was performed on 18 patients. The clinical evaluation at follow-up was performed using the Knee-Society-Score (KSS) and Tegner-Score.</p> <p>Results</p> <p>Subjective results of the operation were classed as excellent or good in 16 of the 18 patients ten years after surgery; persistent instability of the patella was recorded in only one of the 18 patients. The majority of patients returned to the same level of sporting activity after surgery as they had participated in before injury.</p> <p>Conclusions</p> <p>The Roux-Elmslie-Trillat procedure could be recommended in cases presenting with an increased q-angle, trochlea dysplasia or failed soft tissue surgery. In the present study the majority of patients report a return to previous sporting activity ten years after surgery.</p

    Modulating Temporal and Spatial Oxygenation over Adherent Cellular Cultures

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    Oxygen is a key modulator of many cellular pathways, but current devices permitting in vitro oxygen modulation fail to meet the needs of biomedical research. A microfabricated insert for multiwell plates has been developed to more effectively control the temporal and spatial oxygen concentration to better model physiological phenomena found in vivo. The platform consists of a polydimethylsiloxane insert that nests into a standard multiwell plate and serves as a passive microfluidic gas network with a gas-permeable membrane aimed to modulate oxygen delivery to adherent cells. Equilibration time is on the order of minutes and a wide variety of oxygen profiles can be attained based on the device design, such as the cyclic profile achieved in this study, and even oxygen gradients to mimic those found in vivo. The proper biological consequences of the device's oxygen delivery were confirmed in cellular models via a proliferation assay and western analysis of the upregulation of hypoxia inducible transcription factor-1α. These experiments serve as a demonstration for the platform as a viable tool to increase experimental throughput and permit novel experimental possibilities in any biomedical research lab

    Enhancing Nanoparticle-Based Visible Detection by Controlling the Extent of Aggregation

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    Visible indication based on the aggregation of colloidal nanoparticles (NPs) is highly advantageous for rapid on-site detection of biological entities, which even untrained persons can perform without specialized instrumentation. However, since the extent of aggregation should exceed a certain minimum threshold to produce visible change, further applications of this conventional method have been hampered by insufficient sensitivity or certain limiting characteristics of the target. Here we report a signal amplification strategy to enhance visible detection by introducing switchable linkers (SLs), which are designed to lose their function to bridge NPs in the presence of target and control the extent of aggregation. By precisely designing the system, considering the quantitative relationship between the functionalized NPs and SLs, highly sensitive and quantitative visible detection is possible. We confirmed the ultrahigh sensitivity of this method by detecting the presence of 20 fM of streptavidin and fewer than 100 CFU/mL of Escherichia coli

    Measurement of Exclusive B Decays to Final States Containing a Charmed Baryon

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    Using data collected by the CLEO detector in the Upsilon(4S) region, we report new measurements of the exclusive decays of B mesons into final states of the type Lambda_c^+ p-bar n(pi), where n=0,1,2,3. We find signals in modes with one, two and three pions and an upper limit for the two body decay Lambda_c^+ pbar. We also make the first measurements of exclusive decays of B mesons to Sigma_c p-bar n(pi), where n=0,1,2. We find signals in modes with one and two pions and an upper limit for the two body decay Sigma_c p-bar. Measurements of these modes shed light on the mechanisms involved in B decays to baryons.Comment: 11 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, submitted to PR

    Measurement of the Masses and Widths of the Sigma_c^++ and Sigma_c^0 Charmed Baryons

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    Using data recorded by the CLEO II and CLEO II.V detector configurations at CESR, we report new measurements of the masses of the Sigma_c^{++} and Sigma_c^0 charmed baryons, and the first measurements of their intrinsic widths. We find M(Sigma_c^{++}) - M(Lambda_c^+) = 167.4 +- 0.1 +- 0.2 MeV, Gamma(Sigma_c^{++}) = 2.3 +- 0.2 +- 0.3 MeV, and M(Sigma_c^0) - M(Lambda_c^+) = 167.2 +- 0.1 +- 0.2 MeV, Gamma(Sigma_c^0) = 2.5 +- 0.2 +- 0.3 MeV, where the uncertainties are statistical and systematic, respectively.Comment: 9 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, submitted to PRD, Rapid Communications. Reference [13] correcte
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