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An in-depth characterization of nanoparticle-doped optical fibers is crucial to understand the potential new functionalities of the engineered glass and thus their applicability fields. The high temperatures of the manufacturing process strongly affect the nanoparticle features, and therefore, their analysis is necessary after fiber drawing. However, the difficulties associated with the use of atomic resolution microscopies to analyze the nanoparticle features in the fiber core, mainly related to sample preparation and expensive costs, usually prevent their study. In this work, we overcome some of those limitations and demonstrate, for the first time, the suitability of structurally and microstructurally studying in detail nanocrystals contained in a fiber core of â¼10 µm by combining confocal Raman microscopy, Rayleigh light-scattering microscopy, and scanning electron microscopy (SEM). A thorough study of cubic-shaped and rod-shaped YPO4 nanocrystals contained in optical fibers reveals their crystallization in tetragonal (t) and monoclinic (m) structures, respectively. The symmetric (ν1) and asymmetric stretching (ν3) Raman modes display a different and remarkable red shift as particle size decreases in both types of nanocrystals, which in the case of the cubic-shaped nanocrystals is fitted to an exponential function along with a Raman peak broadening. Moreover, their Raman dependence vs temperature is evaluated up to 600 °C, observing a phonon softening that follows a linear behavior, which is discussed in detail. These findings add new insights to pure m-YPO4, which was unknown to date, and the REPO4 family and open up new avenues that can be extrapolated to other nanostructures incorporated into optical fiber cores, which will advance progress in the field of nanoparticle-doped optical fibers.
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Rayleigh scattering enhanced nanoparticles-doped optical fibers are highly promising for distributed sensing applications, however, the high optical losses induced by that scattering enhancement restrict considerably their sensing distance to few meters. Fabrication of long-range distributed optical fiber sensors based on this technology remains a major challenge in optical fiber community. In this work, it is reported the fabrication of low-loss Ca-based nanoparticles doped silica fibers with tunable Rayleigh scattering for long-range distributed sensing. This is enabled by tailoring nanoparticle features such as particle distribution size, morphology and density in the core of optical fibers through preform and fiber fabrication process. Consequently, fibers with tunable enhanced backscattering in the range 25.9-44.9 dB, with respect to a SMF-28 fiber, are attained along with the lowest two-way optical losses, 0.1-8.7 dB/m, reported so far for Rayleigh scattering enhanced nanoparticles-doped optical fibers. Therefore, the suitability of Ca-based nanoparticles-doped optical fibers for distributed sensing over longer distances, from 5 m to more than 200 m, becomes possible. This study opens a new path for future works in the field of distributed sensing, since these findings may be applied to other nanoparticles-doped optical fibers, allowing the tailoring of nanoparticle properties, which broadens future potential applications of this technology.
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BACKGROUND: Fat grafting is a procedure commonly used in breast reconstruction nowadays. Nevertheless, its oncological safety remains controversial. The potential risk that progenitor cells included in fat graft tissue may contribute to disease progression in patients with breast cancer is still debatable. We have designed a matching-cohort study with 250 patients with history of breast cancer trying to elucidate an answer for this question. METHODS: We selected 250 patients with a history of breast cancer in our hospital, between 2011 and 2019. A total of 125 patients (cases) had a history of breast cancer reconstructed with fat grafting. The additional 125 patients are matched controls. We analyzed the distribution of eight different variables within the cases and their matched controls: date of first oncological surgery, age, type of oncological surgery, histological subtype, Her-2 status, pN, smoking habit and diabetes mellitus. The objective of this study was to analyze the influence of fat grafting over breast cancer recurrence. RESULTS: There are not statistically significant differences in breast cancer locoregional recurrences (P=0.183), distant metastases (P=0.200) or total recurrences (P=0.065) amongst the two groups (cancer cases and matched controls). CONCLUSIONS: Our study adds more information over the oncological safety of fat grafting. These findings should encourage long-term prospective trials to provide surgeons with accurate information regarding the role of lipofilling on breast neoplasms.
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SUMMARY: Virtual reality and other technological advancements both inside and outside the operating room have shown an exponential increase in the past two decades. Surgical technique and finesse in delicate procedures have become ever more important, and the onus is on plastic surgeons and plastic surgery residents to meet these needs to provide the best outcomes possible to patients. The ability to learn, simulate, and practice operating in a fashion that poses no harm to any patient is truly a gift from technology to surgery that any surgeon could benefit from, whether trainee or attending. This application of technology and simulation has been demonstrated in other fields such as in the airline industry with flight simulation. The ability to learn, synthesize, and incorporate learned materials and ideas through virtual, augmented, and mixed reality tools offers a great opportunity to put our field at the forefront of a paradigm shift in surgical education. The critical utility of digital education could not be further emphasized any more than in the unfortunate and infrequent situation of a worldwide pandemic. This article reviews some of the important recent technologies that have developed and their applications in plastic surgery education and offers a look into what we can expect in the future.
Assuntos
Realidade Aumentada , Procedimentos de Cirurgia Plástica/métodos , Treinamento por Simulação/métodos , Cirurgia Assistida por Computador/métodos , Cirurgia Plástica/educação , Realidade Virtual , Competência Clínica , Simulação por Computador , Humanos , Aprendizagem , Procedimentos de Cirurgia Plástica/educação , Procedimentos de Cirurgia Plástica/instrumentação , Procedimentos de Cirurgia Plástica/tendências , Treinamento por Simulação/tendências , Cirurgiões/psicologia , Cirurgiões/estatística & dados numéricos , Cirurgia Assistida por Computador/educação , Cirurgia Assistida por Computador/instrumentação , Cirurgia Assistida por Computador/tendências , Cirurgia Plástica/instrumentação , Cirurgia Plástica/métodos , Cirurgia Plástica/tendênciasRESUMO
BACKGROUND: After its initial description in China, Covid-19 is hitting nations across the world, with Spain as the third country in number of deaths, after the USA and Italy. Similarly to what is happening in other countries, an important reduction in available operating rooms is affecting our departments. In this study, we aim to know how Covid-19 pandemic is affecting the delivery of plastic surgery services in Spain. METHODS: A questionnaire addressing some of our concerns about how the Coronavirus crisis might severelyimpact our specialty has been sent to the heads of the divisions of plastic surgery of several hospitals across Spain. RESULTS: A total of 12 plastic surgery departments from different hospitals across the country agreed to participate in the survey. Most plastic surgery teams will need to maintain 50-80% of their staff in order to be able to offer emergency and undelayable oncological procedures. The total amount of procedures currently being performed ranged from 0 to 44% of the figures before the coronavirus outbreak, except for one department, with elective surgery mainly affected. Microsurgical cases have been massively discontinued during this crisis. CONCLUSIONS: Plastic surgery delivery in the Spanish Health System is being severely impacted as a collateral damage from this pandemic. Most of the elective surgery is currently stopped. Our departments seem to be vulnerable regarding their capacity to keep offering emergency care.Level of evidence: not ratable (multi-center survey).
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BACKGROUND: Implant-based immediate approach remains to be a first line option for reconstruction of mastectomy defects. When combined with post-mastectomy radiation therapy (PMRT) two different schemas are possible: radiating the temporary tissue expander (TTE) or the permanent implant (PI). The present article intends to be the biggest cohort meta-analysis to the date comparing reconstructive failure (RF) rate in these two scenarios: PMRT to TE compared with PMRT to PI. METHODS: A systematic search of the literature was performed on PUBMED/MEDLINE. The following key words were chosen: Breast Reconstruction AND Implant based AND Immediate. The time limit applied was from January 2008 to January 2019. We selected ten articles (n=1,130) to perform a meta-analysis due to the similarity of their approaches. Secondly, we did a simple literature review in order to identify some variables possibly working as predicting factors for RF. RESULTS: Previous meta-analysis are analysed. Some variables possibly working as risk factors for RF are summarized. We performed a meta-analysis in two scenarios: a fixed-effect model and a random effect model. For the random effect model an OR of 1.85 was obtained (0.96, 3.57; P=0.067). A funnel plot is performed showing no publication bias exists. CONCLUSIONS: There is a tendency towards a higher RF rate when the TTE is irradiated compared with the irradiation of the PI. Further studies trying to elucidate the influence of the suggested risk factors for RF have to be performed to stablish a consensus about the indications and contraindications of this reconstructive modality.
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Mephedrone is a new synthetic cathinone-derived drug. It is a sympathomimetic drug, and its structure is similar to amphetamines, although its specific pharmacokinetics and metabolism remain unknown. We performed a literature search in PUBMED with the following key words: Mephedrone AND Necrosis AND Hand. No results were found. We performed a second literature search with the following key words: Mephedrone AND Physiopathology AND Side effects, obtaining a total of 7 articles that we read before writing this case report. We will present a case report of a 28-year-old man with distal ischemia in his left hand associated to intra-arterial drug use of mephedrone. The patient ended up having superficial necrosis involving skin and subcutaneous tissue in his thumb, which was treated with wound care. Good quality healing, full range of motion, and normal sensitivity were achieved. There are no previous publications related to any side effects secondary to its intravascular use. The ultimate mechanism producing this distal fingertip necrosis remains undefined.