127 research outputs found
Improvement of P3HT-ICBA solar cell photovoltaic characteristics due to the incorporation of the maleic anhydride additive: P3HT morphology study of P3HT-ICBA and P3HT-ICBA-MA films by means of X-band LESR
© 2014 Published by Elsevier B.V. A light-induced electron spin resonance (LESR) X-band study of poly(3-hexylthiophene)/indene-C60 bisadduct P3HT/ICBA flexible solid films containing the additive maleic anhydride (MA) is presented. An increase of P3HT crystalline domain orientation in P3HT:ICBA:MA in comparison with P3HT:ICBA films was confirmed by the angular LESR spectra dependence of P3HT positive polarons. It was assumed that the average increase of power conversion efficiency in P3HT:ICBA:MA solar cells films, relative to P3HT:ICBA, is connected with the more effective crystalline P3HT phase orientation due to the MA sublimation from the composites blends during annealing. The relative average increase of power conversion efficiency of SC films containing MA in comparison to pure P3HT:ICBA blends is estimated to be a factor of (1.15) higher, while the concentrations of functional composites (polymer/fullerene) in blends made with MA decrease by up to 25-30%
Multifrequency X,W-band ESR study on photo-induced ion radical formation in solid films of mono- and di-fullerenes embedded in conjugated polymers
Anion-cation radical formation in solid films of M3EH-PPV blended with C60-PCBM, C120-O-PCBM and C60-MDHE, C 120-O-MDHE under diode laser (532 nm) and Xe-lamp light excitation studied by means of X,W-band at temperatures 30-80 K is reported. Subsequent high frequency W-band ESR data demonstrate the reproducible, but variable effect of appreciable dispersion (D) contribution in the ESR spectral line for the di-fullerene anion radicals. It is suggested that the increase of the D part relative to the absorption (A) in the summarized ESR absorption line in blends with difullerenes is caused by the higher value of difullerene medium conductivity. The obtained data are quantitatively discussed by the D/A ∼ F(d/δ) functional dependence in approach of plane film geometry, where d is the film thickness and δ is the skin-depth. The influence of ν-dependent δ at D/A value has been checked using X-band LESR. © 2014 Elsevier Ltd. All rights reserved
Statistical Properties of Turbulence: An Overview
We present an introductory overview of several challenging problems in the
statistical characterisation of turbulence. We provide examples from fluid
turbulence in three and two dimensions, from the turbulent advection of passive
scalars, turbulence in the one-dimensional Burgers equation, and fluid
turbulence in the presence of polymer additives.Comment: 34 pages, 31 figure
Perioperative immunomodulation with interleukin-2 in patients with renal cell carcinoma: results of a controlled phase II trial
We conducted a non-randomised controlled phase II trial to investigate the role of preoperative administration of interleukin-2 (IL-2) in patients with renal cell carcinoma undergoing tumour nephrectomy. A total of 120 consecutive patients were allocated alternately to the two study groups: perioperative immunomodulation with IL-2 (IL-2 group; n=60) and perioperative immunomonitoring without immunomodulation (control group; n=60). Patients from the IL-2 group received four doses of 10 × 106 IU m−2 twice daily subcutaneously a week before operation followed by a daily maintenance dose of 3 × 106 IU m−2 subcutaneously until a day before the operation. Parameters of cellular and humoral immunity (leucocytes, T-cell markers CD3, CD4, and CD8, B-cell marker CD19, monocyte marker CD14, natural killer (NK) cell markers CD16, CD56, and CD57, activation markers CD6, CD25, CD28, and CD69, progenitor cell marker CD34, as well as IL-2, IL-6, IL-10, soluble IL-2 receptor, IL-1 receptor antagonist, transforming growth factor-β1, and vascular endothelial growth factor) were measured in peripheral venous blood at various intervals. Interleukin-2-related toxicity was WHO grade 1 (24%), 2 (67%), and 3 (9%). In the postoperative period, T-cell markers, activation markers, and NK cell markers decreased, and IL-6 and IL-10 increased. However, all these alterations were significantly less accentuated in patients who had been pretreated with IL-2. Median follow-up was 40 months. Tumour-specific survival in the IL-2 group and the control group was 98 vs 81% after 1 year and 86 vs 73% after 5 years (P=0.04). A similar effect was found for progression-free survival. We conclude that IL-2 can be safely administered in the perioperative period and modulates immunological parameters. However, to validate the survival data, a larger randomised phase III trial is needed
Determination of nutrient salts by automatic methods both in seawater and brackish water: the phosphate blank
9 páginas, 2 tablas, 2 figurasThe main inconvenience in determining nutrients in seawater by automatic methods is simply solved:
the preparation of a suitable blank which corrects the effect of the refractive index change on the recorded
signal. Two procedures are proposed, one physical (a simple equation to estimate the effect) and the other
chemical (removal of the dissolved phosphorus with ferric hydroxide).Support for this work came from CICYT (MAR88-0245 project) and
Conselleria de Pesca de la Xunta de GaliciaPeer reviewe
Intravesical Treatments of Bladder Cancer: Review
For bladder cancer, intravesical chemo/immunotherapy is widely used as adjuvant therapies after surgical transurethal resection, while systemic therapy is typically reserved for higher stage, muscle-invading, or metastatic diseases. The goal of intravesical therapy is to eradicate existing or residual tumors through direct cytoablation or immunostimulation. The unique properties of the urinary bladder render it a fertile ground for evaluating additional novel experimental approaches to regional therapy, including iontophoresis/electrophoresis, local hyperthermia, co-administration of permeation enhancers, bioadhesive carriers, magnetic-targeted particles and gene therapy. Furthermore, due to its unique anatomical properties, the drug concentration-time profiles in various layers of bladder tissues during and after intravesical therapy can be described by mathematical models comprised of drug disposition and transport kinetic parameters. The drug delivery data, in turn, can be combined with the effective drug exposure to infer treatment efficacy and thereby assists the selection of optimal regimens. To our knowledge, intravesical therapy of bladder cancer represents the first example where computational pharmacological approach was used to design, and successfully predicted the outcome of, a randomized phase III trial (using mitomycin C). This review summarizes the pharmacological principles and the current status of intravesical therapy, and the application of computation to optimize the drug delivery to target sites and the treatment efficacy
Cancer Biomarker Discovery: The Entropic Hallmark
Background: It is a commonly accepted belief that cancer cells modify their transcriptional state during the progression of the disease. We propose that the progression of cancer cells towards malignant phenotypes can be efficiently tracked using high-throughput technologies that follow the gradual changes observed in the gene expression profiles by employing Shannon's mathematical theory of communication. Methods based on Information Theory can then quantify the divergence of cancer cells' transcriptional profiles from those of normally appearing cells of the originating tissues. The relevance of the proposed methods can be evaluated using microarray datasets available in the public domain but the method is in principle applicable to other high-throughput methods. Methodology/Principal Findings: Using melanoma and prostate cancer datasets we illustrate how it is possible to employ Shannon Entropy and the Jensen-Shannon divergence to trace the transcriptional changes progression of the disease. We establish how the variations of these two measures correlate with established biomarkers of cancer progression. The Information Theory measures allow us to identify novel biomarkers for both progressive and relatively more sudden transcriptional changes leading to malignant phenotypes. At the same time, the methodology was able to validate a large number of genes and processes that seem to be implicated in the progression of melanoma and prostate cancer. Conclusions/Significance: We thus present a quantitative guiding rule, a new unifying hallmark of cancer: the cancer cell's transcriptome changes lead to measurable observed transitions of Normalized Shannon Entropy values (as measured by high-throughput technologies). At the same time, tumor cells increment their divergence from the normal tissue profile increasing their disorder via creation of states that we might not directly measure. This unifying hallmark allows, via the the Jensen-Shannon divergence, to identify the arrow of time of the processes from the gene expression profiles, and helps to map the phenotypical and molecular hallmarks of specific cancer subtypes. The deep mathematical basis of the approach allows us to suggest that this principle is, hopefully, of general applicability for other diseases
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