9 research outputs found
Multimedia archives: New digital filters to correct equalization errors on digitized audio tapes
Multimedia archives face the problem of obsolescing and degrading analogue media (e.g., speech and music recordings and video art). In response, researchers in the field have recently begun studying ad hoc tools for the preservation and access of historical analogue documents. This paper investigates the active preservation process of audio tape recordings, specifically focusing on possible means for compensating equalization errors introduced in the digitization process. If the accuracy of corrective equalization filters is validated, an archivist or musicologist would be able to experience the audio as a historically authentic document such that their listening experience would not require the recovery of the original analogue audio document or the redigitization of the audio. Thus, we conducted a MUSHRA-inspired perception test (n = 14) containing 6 excerpts of electronic music (3 stimuli recorded NAB and 3 recorded CCIR). Participants listened to 6 different equalization filters for each stimulus and rated them in terms of similarity. Filters included a correctly digitized "Reference,"an intentionally incorrect "Foil"filter, and a subsequent digital correction of the Foil filter that was produced with a MATLAB script. When stimuli were collapsed according to their filter type (NAB or CCIR), no significant differences were observed between the Reference and MATLAB correction filters. As such, the digital correction appears to be a promising method for compensation of equalization errors although future study is recommended, specifically containing an increased sample size and additional correction filters for comparison
Daily Serum Collection after Acellular Dermal Matrix-Assisted Breast Reconstruction
Background The acellular dermal matrix (ADM)-assisted breast reconstruction technique is widely known, but discouraging results due to early postoperative complications have been reported. As the literature identifies seroma as the most common issue after breast surgery without identifying its pathogenesis, we aimed to report the trend of postoperative daily serum collection after ADM-assisted breast reconstruction and compare it with data in the literature in order to discover more about this little-known topic.
Methods A retrospective study on 28 consecutive patients who received ADM-assisted breast reconstruction between February 2013 and February 2014 was performed. In order to reduce the number of variables that could affect serum production, only one brand of ADM was used and all tissues were handled gently and precisely. The daily drainage volume was recorded per patient during the first four days of hospitalization. Likewise, postoperative complications were noted during routine follow-up.
Results In total, five (17.9%) bilateral and 23 (82.1%) unilateral ADM-assisted breast reconstructions (33 implants) were performed. The mean age, body mass index, and length of hospital stay were 53.6 years, 21.3 kg/m2, and 4.5 days, respectively. One major complication led to implant loss (3.0%), and nine minor complications were successfully treated with ambulatory surgery (27.3%). Serum collection linearly decreased after 24 hours postoperatively.
Conclusions Daily drainage decreased following the theoretical decline of acute inflammation. In concordance with the literature, daily serum production may not be related to the use of ADM
An Innovative Fluid Dynamic System to Model Inflammation in Human Skin Explants
Skin is a major administration route for drugs, and all transdermal formulations must be tested for their capability to overcome the cutaneous barrier. Therefore, developing highly reliable skin models is crucial for preclinical studies. The current in vitro models are unable to replicate the living skin in all its complexity; thus, to date, excised human skin is considered the gold standard for in vitro permeation studies. However, skin explants have a limited life span. In an attempt to overcome this problem, we used an innovative bioreactor that allowed us to achieve good structural and functional preservation in vitro of explanted human skin for up to 72 h. This device was then used to set up an in vitro inflammatory model by applying two distinct agents mimicking either exogenous or endogenous stimuli: i.e., dithranol, inducing the contact dermatitis phenotype, and the substance P, mimicking neurogenic inflammation. Our in vitro system proved to reproduce inflammatory events observed in vivo, such as vasodilation, increased number of macrophages and mast cells, and increased cytokine secretion. This bioreactor-based system may therefore be suitably and reliably used to simulate in vitro human skin inflammation and may be foreseen as a promising tool to test the efficacy of drugs and cosmetics
Ex Vivo Evaluation of Ethosomes and Transethosomes Applied on Human Skin: A Comparative Study
In this study, the transdermal fate of vesicular nanosystems was investigated. Particularly, ethosomes based on phosphatidylcholine 0.9% w/w and transethosomes based on phosphatidylcholine 0.9 or 2.7% w/w plus polysorbate 80 0.3% w/w as an edge activator were prepared and characterized. The vesicle mean size, morphology and deformability were influenced by both phosphatidylcholine and polysorbate 80. Indeed, the mean diameters of ethosome were around 200 nm, while transethosome’s mean diameters were 146 or 350 nm in the case of phosphatidylcholine 0.9 or 2.7%, w/w, respectively. The highest deformability was achieved by transethosomes based on phosphatidylcholine 0.9%, w/w. The three types of vesicular nanosystems were applied on explanted human skin maintained in a bioreactor. Transmission electron microscopy demonstrated that all vesicles were able to enter the skin, keeping their structural integrity. Notably, the vesicle penetration capability was influenced by their physical-chemical features. Indeed, ethosomes reached keratinocytes and even the dermis, phosphatidylcholine 0.9% transethosomes were found in keratinocytes and phosphatidylcholine 2.7% transethosomes were found only in corneocytes of the outer layer. These findings open interesting perspectives for a differentiated application of these vesicles for transdermal drug delivery as a function of the cutaneous pathology to be addressed
Association of CDK4 germline and BRAF somatic mutations in a patient with multiple primary melanomas and BRAF inhibitor resistance
Many genetic alterations, including predisposing or somatic mutations, may contribute toward the development of melanoma. Although CDKN2A and CDK4 are high-penetrance genes for melanoma, MC1R is a low-penetrance gene that has been associated most consistently with the disease. Moreover, BRAF is the most frequently somatically altered oncogene and is a validated therapeutic target in melanoma. This paper reports a case of multiple primary melanoma with germline CDK4 mutation, MC1R variant, and somatic BRAF mutation in nine out of 10 melanomas, indicating that a common pathogenesis, because of a predisposing genetic background, may be shared among distinct subsequent melanomas of probable clonal origin. After 3 months of targeted therapy with BRAF inhibitor, our patient developed resistance with rapid progression of the disease leading to death. This is the first case in which early resistance to BRAF inhibitor has been reported in a patient with CDK4 germline mutation