Photovoltaic Devices: High‐Performance Organic Solar Cells with Spray Coated Hole‐Transport and Active Layers (Adv. Funct. Mater. 1/2011)

In this study, we report high performance organic solar cells with spray coated hole‐transport and active layers. With optimized ink formulations we are able to deposit films with controlled thickness and very low surface roughness (<10 nm). Specifically we deposit smooth and uniform 40 nm thick films of poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as well as films composed of a mixture of poly(3‐hexyl thiophene) (P3HT) and the C₆₀‐derivative (6,6)‐phenyl C61‐butyric acid methyl ester (PCBM) with thicknesses in the range 200–250 nm. To control film morphology, formation and thickness, the optimized inks incorporate two solvent systems in order to take advantage of surface tension gradients to create Marangoni flows that enhance the coverage of the substrate and reduce the roughness of the film. Notably, we achieve fill factors above 70% and attribute the improvement to an enhanced P3HT crystallization, which upon optimized post‐drying thermal annealing results in a favorable morphology. As a result, we could extend the thickness of the layer to several hundreds of nanometers without noticing a substantial decrease of the transport properties of the layer. By proper understanding of the spreading and drying dynamics of the inks we achieve spray coated devices with power conversion efficiency of 3.75%, with fill factor, short circuit current and open circuit voltage of 70%, 9.8 mA cm^?2 and 550 mV, respectively.     

Tunable transform-limited pulse generation using self-injectionlocking of an FP laser

Wavelength-tunable, near transform-limited pulses have been generated using a Fabry-Perot laser diode coupled to a fiber loop containing a fiber Fabry-Perot resonator (FFPR) and a polarization controller. The ratio of transmitted to reflected light from the loop can be adjusted using the polarization controller. Single-mode operation of the gain-switched laser is achieved by self-injection locking, which is induced by light reflected from the fiber loop. The resulting output pulse has a time-bandwidth product of 0.4 and is tunable over about 15 nm by varying the tuning voltage of the FFPR     

Degradation of cell wall material of apple and wheat bran by human faecal bacteria in vitro

The effect of the structures of plant cell walls and their component polymers on the degradability of dietary fibre by bacteria of the human colon was investigated by inoculating culture media containing cell wall materials of apple and wheat bran with slurries of human faeces which were then incubated for periods of up to 72 h. In the apple substrates the amounts of pectic polysaccharides were extensively depleted after 12 h, and after 24 h over 90% of the initial carbohydrate had been degraded. Material which remained after incubation was probably comprised of highly branched fragments of rhamnogalacturonans, cross-linked by phenolics and proteins, highly branched fragments of cross-linked xyloglucans, and degraded cellulose. In wheat bran the aleurone layer was preferentially degraded, but the glucuronoarabinoxylans, which were cross-linked by phenolic groups, and the lignified outer layers of the bran were very resistant to attack. Bacteria adhered mainly to the broken or damaged surfaces of the plant cell walls, and in the more resistant tissues only penetrated the intercellular regions.     

Answer Justification in Diagnostic Expert Systems?Part II: Supporting Plausible Justifications

This paper describes how a new method for answer justification in abductive diagnostic expert systems, presented in a preceding companion paper (Part I), can be supported in a domain-independent fashion. Both the issues of explaining why a disorder is included in a differential diagnosis and why it is ranked the way it is relative to its "competitors" are addressed. This approach to answer justification is then compared to previous work on answer justification in medical expert systems.     

Parameters for the measurement of long-term effects of an orally administered drug in organic and functional circulatory disorders. Preliminary communication

In many cases of drug-induced allergic hepatitis, peripheral lymphocytes were transformed by the stimulation with a given drug in the presence of autologous serum. However, when rat liver microsome fraction of soluble liver specific antigen fraction was added to the culture instead of autologous serum, the drug-induced lymphocyte transformation was more efficiently seen than autologus serum, while rat liver mitochondria fraction was less effective. On the other hand, in the cases of allergic drug eruption which did not show any liver injury, the addition of liver subcellular fractions were much less effective to induce the lymphocyte transformation than autologous serum. These results may suggest that liver subcellular component is involved in pathogenesis of drug-induced allergic hepatitis.     

Higher-plant mitochondrial ribosomes contain a 5S ribosomal ribonucleic acid component

Ribosomes from higher-plant mitochondria contain 5S rRNA, in contrast with the mitochondrial ribosomes of animals and fungi, in which such a component has not been detected. In common with the ribosomes of prokaryotes and chloroplasts, higher-plant mitochondrial ribosomes do not appear to contain an RNA equivalent to the 5.8 S rRNA that is found in eukaryoytes hydrogen-bonded to the largest of the cytoplasmic rRNA species.     

Cytolytic antibodies to murine lymphomas elicited by immunization with allogenic and syngenic tumors

Five quaternary ammonium germicides (QAGs) were tested for their adsorption by agar. This was found to be in the following ascending order: alkylbenzylmethyl-ammonium chloride, alkyltrimethylammonium bromide, cetyltrimethylammonium bromide, cetylpyrimidinium chloride and cetylbenzyldimethylammonium chloride. An inverse relationship was established between the extent of agar binding of the QAGs and their inhibition zones. In an attempt to develop a sensitive cup-plate assaying technique suitable for QAGs, important factors affecting the agar-diffusion of QAGs were investigated. These included the influence of various polysorbates, buffer ions, agars and test organisms. Furthermore, the effect of the pH and/or the concentration of the selected polysorbate and the buffer were studied. The best medium developed for the sensitive agar-diffusion assay of QAGs was nutrient agar-Tris (0.05 M, pH 8) provided that distilled water and polysorbate 20 (0.5%) were used as diluents for the mixed alkyl and the pure cetyl QAGs, respectively.     

Experimental colitis

Ulcerative colitis and Crohn's disease are complex, problematic diseases of unknown etiology in man, and appropriate experimental models would be useful in elucidating their pathogenesis and treatment. Although there have been numerous attempts to produce inflammatory ulcerative colonic disease in laboratory animals resembling those human disease forms, none has been entirely successful. Investigators have conducted experiments involving almost every etiological factor suggested for initiation of these diseases. The methods reviewed in this paper include production of experimental colitis by vascular impairment, and immunological methods such as bacterial infection, allergic reactions, direct and indirect hypersensitivity reactions, as well as autoimmune mechanisms. The results of carrageenan-induced colitis, irradiation, dietary, and drug-induced techniques are also discussed and the frequency and nature of spontaneous colonic lesions in animals is summarized.     

Plasma urea in hypertensive patients

The annual increase in plasma urea was measured in 253 hypertensive patients. On average there was a significant increase in plasma urea with time which did not depend on the sex of the patient or the type of hypertension. It did, however, depend on the initial level of plasma urea. A table giving the upper limits for expected annual increment may prove useful in clinical assessment. The relation between plasma urea and presenting blood pressure and age was examined in 1217 patients seen at the Hammersmith Hospital hypertension clinic from 1952 to 1967. The plasma urea was significantly related to both age and diastolic and systolic blood pressure. It was higher in men than in women up to 60 years of age, but not above that age, and it increased with presenting mean blood pressure in both sexes, but the increase was greater in men. There was a quadratic relation between age and plasma urea in both men and women. In both sexes the plasma urea increased between the ages of 60 and 80.