50 research outputs found
Entanglement of Imaging and Imagining of Nanotechnology
Images, ranging from visualizations of the nanoscale to future visions, abound within and beyond the world of nanotechnology. Rather than the contrast between imaging, i.e. creating images that are understood as offering a view on what is out there, and imagining, i.e. creating images offering impressions of how the nanoscale could look like and images presenting visions of worlds that might be realized, it is the entanglement between imaging and imagining which is the key to understanding what images do. Three main arenas of entanglement of imag(in)ing and the tensions involved are discussed: production practices and use of visualizations of the nanoscale; imag(in)ing the future and the present; and entanglements of nanoscience and art. In these three arenas one sees struggles about which images might stand for nanotechnology, but also some stabilization of the entanglement of imag(in)ing, for example in established rules in the practices of visualizing the nanoscale. Three images have become iconic, through the combination of their wide reception and further circulation. All three, the IBM logo, the Foresight Instituteâs Nanogear image, and the so-called Nanolouse, depict actual or imagined technoscientific objects and are thus seen as representing technoscientific achievements â while marking out territory
Dispersion and release of embelin from electrospun biodegradable, polymeric, membranes
In this work, microfiber meshes containing embelin, a poorly water-soluble bioactive agent, were prepared by solubilizing embelin in a biodegradable and biocompatible polymer matrix of poly(Δ-caprolactone) (PCL). Plain or drug-loaded, highly porous, fibrous membranes with a high area-to-volume ratio were obtained by electrospinning. Non-woven microfibrous meshes were formed by uniform bead-free fibers with a mean diameter of 1.2âÎŒm. Non-porous films were obtained by solution casting, and were used for comparison. The drug-loading content of the prepared systems was appropriate for topical applications. The thermal properties revealed that the crystallinity of embelin significantly decreased, the drug having almost completely dissolved in the PCL fibers. The in situ bioavailability of embelin, an antimycotic agent, is an important aspect to consider in topical drug applications. The drug-loaded systems presented different contact areas with the biological environment. When comparing the ability to expose embelin with the biological environment of the prepared systems, drug-loaded fibrous scaffolds showed a higher bioavailability of the bioactive agent because of an increase by 86% in the area-to-volume ratio, providing an effective area per unit mass that was 5.8-fold higher than that of the film. For the meshes, 90% embelin release was observed after 12h of exposure to phosphate-buffered saline, whereas for the films a comparable level of release occurred only after 72h.Fil: Cortez Tornello, Pablo Roberto. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Mar del Plata. Instituto de InvestigaciĂłn En Ciencia y TecnologĂa de Materiales (i); Argentina. Universidad Nacional de San Juan. Facultad de IngenierĂa. Instituto de BiotecnologĂa; ArgentinaFil: Feresin, Gabriela Egly. Universidad Nacional de San Juan. Facultad de IngenierĂa. Instituto de BiotecnologĂa; ArgentinaFil: Tapia, Alejandro. Universidad Nacional de San Juan. Facultad de IngenierĂa. Instituto de BiotecnologĂa; ArgentinaFil: Veiga, Itiara G.. Universidade Estadual de Campinas; BrasilFil: Moraes, Ăngela M.. Universidade Estadual de Campinas; BrasilFil: Abraham, Gustavo Abel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Mar del Plata. Instituto de InvestigaciĂłn En Ciencia y TecnologĂa de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de IngenierĂa; ArgentinaFil: Cuadrado, Teresita Raquel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Mar del Plata. Instituto de InvestigaciĂłn En Ciencia y TecnologĂa de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de IngenierĂa; Argentin
Sigmund Exner's (1887) einige beobachtungen ĂŒber bewegungsnachbilder (some observations on movement aftereffects):an illustrated translation with commentary
In his original contribution, Exnerâs principal concern was a comparison between the properties of different aftereffects, and particularly to determine whether aftereffects of motion were similar to those of color and whether they could be encompassed within a unified physiological framework. Despite the fact that he was unable to answer his main question, there are some excellentâso far unknownâcontributions in Exnerâs paper. For example, he describes observations that can be related to binocular interaction, not only in motion aftereffects but also in rivalry. To the best of our knowledge, Exner provides the first description of binocular rivalry induced by differently moving patterns in each eye, for motion as well as for their aftereffects. Moreover, apart from several known, but beautifully addressed, phenomena he makes a clear distinction between motion in depth based on stimulus properties and motion in depth based on the interpretation of motion. That is, the experience of movement, as distinct from the perception of movement. The experience, unlike the perception, did not result in a motion aftereffect in depth
Silver colloidal nanoparticle stability: influence on Candida biofilms formed on denture acrylic
Our aim in this study was to evaluate how the chemical stability of silver nanoparticles (SNs) influences their efficacy against Candida albicans and C. glabrata biofilms. Several parameters of SN stability were tested, namely, temperature (50ÂșC, 70ÂșC, and 100ÂșC), pH (5.0 and 9.0), and time of contact (5 h and 24 h) with biofilms. The control was defined as SNs without temperature treatment, pH 7, and 24 h of contact. These colloidal suspensions at 54 mg/L were used to treat mature Candida biofilms (48 h) formed on acrylic. Their efficacy was determined by total biomass and colony-forming unit quantification. Data were analyzed using analysis of variance and the Bonferroni post hoc test (=0.05). The temperature and pH variations of SNs did not affect their efficacy against the viable cells of Candida biofilms (P > 0.05). Moreover, the treatment periods were not decisive in terms of the susceptibility of Candida biofilms to SNs. These findings provide an important advantage of SNs that may be useful in the treatment of Candida-associated denture stomatitis.We thank Dr David Williams, Cardiff University, Cardiff, UK, for providing the strain 324LA/94. The authors also thank Sao Paulo Research Foundation (FAPESP, process 2009/15146-5), Brazil, for supporting the work of D. R. M. The authors are indebted to Laboratorio Interdisciplinar de Eletroquimica e Ceramica, Federal University of Sao Carlos, Brazil, in the name of Andressa Kubo, for preparing and characterizing the colloidal suspensions of silver nanoparticles
TTC5 syndrome: Clinical and molecular spectrum of a severe and recognizable condition.
Biallelic mutations in the TTC5 gene have been associated with autosomal recessive intellectual disability (ARID) and subsequently with an ID syndrome including severe speech impairment, cerebral atrophy, and hypotonia as clinical cornerstones. A TTC5 role in IDs has been proposed based on the physical interaction of TTC5 with p300, and possibly reducing p300 co-activator complex activity, similarly to what was observed in Menke-Hennekam 1 and 2 patients (MKHK1 and 2) carrying, respectively, mutations in exon 30 and 31 of CREBBP and EP300, which code for the TTC5-binding region. Recently, TTC5-related brain malformation has been linked to tubulinopathies due to the function of TTC5 in tubulins' dynamics. We reported seven new patients with novel or recurrent TTC5 variants. The deep characterization of the molecular and phenotypic spectrum confirmed TTC5-related disorder as a recognizable, very severe neurodevelopmental syndrome. In addition, other relevant clinical aspects, including a severe pre- and postnatal growth retardation, cryptorchidism, and epilepsy, have emerged from the reversal phenotype approach and the review of already published TTC5 cases. Microcephaly and facial dysmorphism resulted in being less variable than that documented before. The TTC5 clinical features have been compared with MKHK1 published cases in the hypothesis that clinical overlap in some characteristics of the two conditions was related to the common p300 molecular pathway