PEDOT-Carbon Nanotube Counter Electrodes and Bipyridine Cobalt (II/III) Mediators as Universally Compatible Components in Bio-Sensitized Solar Cells Using Photosystem I and Bacteriorhodopsin

In nature, solar energy is captured by different types of light harvesting protein–pigment complexes. Two of these photoactivatable proteins are bacteriorhodopsin (bR), which utilizes a retinal moiety to function as a proton pump, and photosystem I (PSI), which uses a chlorophyll antenna to catalyze unidirectional electron transfer. Both PSI and bR are well characterized biochemically and have been integrated into solar photovoltaic (PV) devices built from sustainable materials. Both PSI and bR are some of the best performing photosensitizers in the bio-sensitized PV field, yet relatively little attention has been devoted to the development of more sustainable, biocompatible alternative counter electrodes and electrolytes for bio-sensitized solar cells. Careful selection of the electrolyte and counter electrode components is critical to designing bio-sensitized solar cells with more sustainable materials and improved device performance. This work explores the use of poly (3,4-ethylenedioxythiophene) (PEDOT) modified with multi-walled carbon nanotubes (PEDOT/CNT) as counter electrodes and aqueous-soluble bipyridine cobalt^II/III complexes as direct redox mediators for both PSI and bR devices. We report a unique counter electrode and redox mediator system that can perform remarkably well for both bio-photosensitizers that have independently evolved over millions of years. The compatibility of disparate proteins with common mediators and counter electrodes may further the improvement of bio-sensitized PV design in a way that is more universally biocompatible for device outputs and longevity.     

Characterization and Functionality of Frozen Muscle Protein in Volador (Illexcoindetii), Pota (Todaropsis eblanae), and Octopus (Eledone cirrhosa)

ABSTRACT: Three species of cephalopods: volador (Illex coindetii) , pota (Todaropsis eblanae) , and octopus (Eledone cirrhosa) were classified according to sex, stage of sexual development, and anatomical zone for characterization and functionality of their muscle proteins. The 3 species exhibited very similar levels of total protein. Octopus mantles and arms contained the least proline and the most hydroxyproline. The highest solubility values in immature pota coincided with the lowest apparent viscosity and emulsifying capacity values. The highest insolubility values observed in octopus coincided with the highest viscosity and emulsifying capacity values. However, in volador which exhibited an intermediate solubility, viscosity was very high and emulsifying capacity was very low.     

Muscle protein solubility of some cephalopods (pota and octopus) during frozen storage

This study relates to myofibrillar and sarcoplasmic protein solubility in 5% NaCl and collagen solubility in 0.05 M acetic acid, from muscle and mantle of pota (Todaropsis eblanae) and octopus (Eledone cirrhosa) kept in frozen storage for 12 months. In both species, protein solubility in 5% NaCl remained high, over 60%, throughout the storage period. Solubility was lower in the octopus than in the pota lots. The species also behaved differently in terms of the increase in solubility, which occurred earlier in octopus (after 2 months) than in pota (after 5–6 months). Thereafter, solubility gradually declined. The values for solubility of proteins from mantle of both pota and octopus in 5% NaCl were greater in young specimens than in mature samples. There was no clear gender‐dependent tendency. The acid solubility of collagen also increased in most lots up to the sixth month, after which it characteristically began to decline. Pota collagen was significantly more soluble in mantles than in arms. In octopus mantle, collagen solubility gradually declined. In the sexually developed phases (immature and mature), no gender‐dependent differences were detected in the solubility of collagen from octopus mantle and arms. However, values did tend to be slightly higher in females. The mantles of immature specimens of pota and octopus were more suitable for freezing. © 2002 Society of Chemical Industry     

Controlled atmosphere as coadjuvant to chilled storage for prevention of melanosis in shrimps (<Emphasis Type="Italic">Parapenaeus longirostris</Emphasis>)

The effect of a controlled atmosphere with high CO₂ and low O₂ levels on melanosis in deepwater pink shrimps (Parapenaeus longirostris) treated with sulphites was studied in samples in chilled storage. The application of atmosphere in shrimps without antimelanotics did not inhibit melanosis. Shrimps treated with 4% sulphites in combination with a concentration of 53% CO₂ and 7% O₂ totally inhibited darkening during storage. Covering with crushed ice produced an undesirable shrinking of muscle shrimp after cooking. The application of lower concentrations of CO₂ (45%) reduced the effectiveness in preventing darkening, compared with 53% CO₂, except where the melanosis inhibitor was 4-hexylresorcinol (0.1%). The residual effect of the gas when the shrimps were kept in a controlled atmosphere for 24 h was insufficient to prevent melanosis during further cold storage.     

Sternal cleft. Surgical treatment in the newborn

The lack of total sternal fusion without other anomalies of the chest wall is extremely rare. We present the case of one 24 h. old female, clinically asymptomatic with complete sternal cleft without other symptoms. She was operated on within the first week of life, a sternal primary suture with costal condrotomy and alternate costal suture were performed. Good thoracic stability was obtained. We agree with other authors about the need for surgical correction during the neonatal period.     

Double outlet right ventricle with L-position of the aorta, D-loop, subaortic VSD, and pulmonary stenosis

We describe a case of double outlet right ventricle with subaortic ventricular septal defect and pulmonary stenosis treated successfully with cardiopulmonary bypass. We consider the clinical history and angiocardiographic and surgical findings of this rare anomaly. We stress the difficulties of reconstruction of the outflow tract of the right ventricle, because of the anomalous pathway of the right coronary artery, the posterior situation of the pulmonary artery, and the abnormal anatomy present in the outflow tract of the right ventricle.     

An algebraic method for smoothing surface triangulations on a local parametric space

This paper presents a new procedure to improve the quality of triangular meshes defined on surfaces. The improvement is obtained by an iterative process in which each node of the mesh is moved to a new position that minimizes a certain objective function. This objective function is derived from algebraic quality measures of the local mesh (the set of triangles connected to the adjustable or free node). If we allow the free node to move on the surface without imposing any restriction, only guided by the improvement of the quality, the optimization procedure can construct a high‐quality local mesh, but with this node in an unacceptable position. To avoid this problem the optimization is done in the parametric mesh, where the presence of barriers in the objective function maintains the free node inside the feasible region. In this way, the original problem on the surface is transformed into a two‐dimensional one on the parametric space. In our case, the parametric space is a plane, chosen in terms of the local mesh, in such a way that this mesh can be optimally projected performing a valid mesh, that is, without inverted elements. Several examples and applications presented in this work show how this technique is capable of improving the quality of triangular surface meshes. Copyright © 2005 John Wiley & Sons, Ltd.