Validation of a Methodology for Cure Process Optimization of Thick Composite Laminates

The cure degree must be as uniform as possible during the manufacture cycle of polymer–matrix composite laminate to obtain parts without defects. Thermal cycle recommended by technical sheet is usually suitable for thin components, so its redesign is necessary to solve unconformities for thick laminate parts, which usually show these problems. In this study, a methodology to optimize the cure cycle of a thick composite laminate, presented in previous studies, has been validated by a more reliable direct method based on dielectrical analysis through the use of an interdigital sensor capable to measure the local cure degree trend.     

Usefulness of Photodynamic Therapy as a Possible Therapeutic Alternative in the Treatment of Basal Cell Carcinoma

Basal cell carcinoma (BCC) is the most common cancer in individuals with fair skin type (I–II) and steadily increasing in incidence (70% of skin malignancy). It is locally invasive but metastasis is usually very rare, with an estimated incidence of 0.0028%–0.55%. Conventional therapy is surgery, especially for the H region of the face and infiltrative lesions; in case of inoperable tumors, radiotherapy is a valid option. Recently, topical photodynamic therapy (PDT) has become an effective treatment in the management of superficial and small nodular BCC. PDT is a minimally invasive procedure that involves the administration of a photo-sensibilizing agent followed by irradiation at a pre-defined wavelength; this determines the creation of reactive oxygen species that specifically destroy target cells. The only major side effect is pain, reported by some patients during the irradiation. The high cure rate and excellent cosmetic outcome requires considering this possibility for the management of patients with both sporadic and hereditary BCC. In this article, an extensive review of the recent literature was made, in order to clarify the role of PDT as a possible alternative therapeutic option in the treatment of BCC.     

Absolute Determination of the Gelling Point of Gelatin under Quasi‐thermodynamic Equilibrium

Thermodynamic studies on phase transformation of biopolymers in solution are useful to understand their nature and to evaluate their technological potentials. Thermodynamic studies should be conducted avoiding time‐related phenomena. This condition is not easily achieved in hydrophilic biopolymers. In this contribution, the simultaneous effects of pH, salt concentration, and cooling rate (Cr) on the folding from random coil to triple helical collagen‐like structures of gelatin were systematically studied. The phase transformation temperature at the absolute invariant condition of Cr = 0 °C/min (T_T^Cr=0) is introduced as a conceptual parameter to study phase transformations in biopolymers under quasi‐thermodynamic equilibrium and avoiding interferences coming from time‐related phenomena. Experimental phase diagrams obtained at different Cr are presented. The T_T^Cr=0 compared with pH and T_T^Cr=0 compared with [NaCl] diagram allowed to explore the transformation process at Cr = 0 °C/min. The results were explained by electrostatic interactions between the biopolymers and its solvation milieu.     

Prospects for fast Rydberg gates on an atom chip

Atom chips are a promising candidate for a scalable architecture for quantum information processing provided a universal set of gates can be implemented with high fidelity. The difficult part in achieving universality is the entangling two-qubit gate. We consider a Rydberg phase gate for two atoms trapped on a chip and employ optimal control theory to find the shortest gate that still yields a reasonable gate error. Our parameters correspond to a situation where the Rydberg blockade regime is not yet reached. We discuss the role of spontaneous emission and the effect of noise from the chip surface on the atoms in the Rydberg state.     

AN ENERGY ANALYSIS OF BELT POLISHING PROCESS AND ITS APPLICATIONS TO TIME CYCLE AND TRACKING EFFECTS

Belt polishing is a fine machining process widely used to improve surface texture and to increase wear resistance and fatigue life. Despite the basics of this manufacturing process are not yet well understood, the cycle-time and the belt oscillations frequency are considered as fundamental process variables. In this article, their effects on the surface characterization and on the form aspects are investigated in connection with the principal physical mechanisms activated during the superfinishing operations (cutting, ploughing and sliding). With this aim, an energy approach of the belt polishing process, coupled with SEM observations of the abrasive belt, is introduced. Two belt polishing energetic regimes are identified and then discussed.     

Buccal tablets containing cysteine and chlorhexidine for the reduction of acetaldehyde levels in the oral cavity

There is growing evidence that a large proportion of upper digestive tract tumors are ascribable to heavy alcohol drinking and tobacco consumption. The cancer-promoting action of ethanol is mediated by acetaldehyde, its first metabolite, also derived from the bacterial oxidation of alcohol by the oral microflora, classified by the International Agency for the Research on Cancer as a carcinogen. Acetaldehyde is also one of the major components of tobacco smoke. These findings suggest two different strategies to decrease the risk of alcohol-related oral cancers: the reduction of the levels of alcohol-derived acetaldehyde in saliva and the reduction of oral bacterial flora. Therefore, the aim of our study was to develop and characterize some buccal tablet formulations containing both 20 mg L-cysteine hydrochloride (able to chemically neutralize acetaldehyde) and 10 mg chlorhexidine diacetate (well-known antiseptic compound active against a large spectrum of oral microbes). One of these formulations, chosen on the basis of its favourable delivery kinetics of the active principles, was demonstrated to be able to reduce acetaldehyde concentration in an in vitro system and to lower its salivary levels in volunteers after ethanol contact. Our findings support the hypothesis that the application of buccal devices containing cysteine and chlorhexidine could reduce salivary acetaldehyde levels and thus the incidence of upper gastrointestinal cancer in drinkers and smokers.