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12 p.-5 fig., Optical probes operating in the second near-infrared window (NIR-II, 1,000-1,700 nm), where tissues are highly transparent, have expanded the applicability of fluorescence in the biomedical field. NIR-II fluorescence enables deep-tissue imaging with micrometric resolution in animal models, but is limited by the low brightness of NIR-II probes, which prevents imaging at low excitation intensities and fluorophore concentrations. Here, we present a new generation of probes (Ag2S superdots) derived from chemically synthesized Ag2S dots, on which a protective shell is grown by femtosecond laser irradiation. This shell reduces the structural defects, causing an 80-fold enhancement of the quantum yield. PEGylated Ag2S superdots enable deep-tissue in vivo imaging at low excitation intensities (, Authors thank Dr A. Benayas (CICECO, U. Aveiro, Portugal), Prof G. Lifante and Prof J. García Sole (UAM) for helpful discussions. This work has been founded by Ministerio de Economı́a y Competitividad-MINECO (MAT2017-83111R and MAT2016-75362-C3-1-R) and the Comunidad de Madrid (B2017/BMD-3867 RENIM-CM) co-financed by European Structural and Investment Fund. D.M.-G. thanks UCM-Santander for a predoctoral contract (CT17/17-CT18/17). We thank the staff at the ICTS-National Centre for Electron Microscopy at the UCM for the help in the electron microscopy studies and C.M. at the beamline BL22-CLAESS of the Spanish synchrotron ALBA for his help in the XANES experiments. We also thank J.G.I at the Ultrafast Laser Laboratory at UCM for his help and fruitful discussion. Y.S. acknowledges the support from the China Scholarship Council (CSC File No. 201806870023). Additional funding was provided by the European Commission Horizon 2020 project NanoTBTech, the Fundación para la Investigación Biomédica del Hospital Universitario Ramón y Cajal project IMP18_38 (2018/0265). Ajoy K. Kar and Mark D. Mackenzie acknowledge support from the UK Engineering and Physical Sciences Research Council (Project CHAMP, EP/M015130/1). C. Jacinto thanks the financial support of the Brazilian agencies: CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico) through the grants: Projeto Universal Nr. 431736/2018-9 and Scholarship in Research Productivity 1C under the Nr. 304967/20181; FINEP (Financiadora de Estudos e Projetos) through the grants INFRAPESQ-11 and INFRAPESQ-12; FAPEAL (Fundação de Amparo à Pesquisa do Estado de Alagoas) grant Nr. 1209/2016. H. D. A. Santos was supported by a graduate studentship from CNPq and by a sandwich doctoral program (PDSE-CAPES) developed at Universidad Autonoma de Madrid, Spain, Project Nr. 88881/2016-01.

Aim: To evaluate the use of CMAP tools® software as a teaching strategy of skeletal muscle components and contraction in undergraduates students of physical education. Methods: Nineteen students from the discipline of fundamentals of human physiology of the undergraduate course of physical education of the Centro Universitário Padre Anchieta were engaged in this study. Students were asked to divide into groups of three people and to bring a notebook with CMAP tools® software installed. During class, students were responsible for creating conceptual maps in CMAP tools® software describing each step of skeletal muscle components and contraction. To assess the effectiveness of this strategy in assisting learning related to skeletal muscle components and contraction, we created a visual learning scale (ranging from 0 (did not help) to 10 (helped a lot)) and applied to students at the end of the class. Results: From the students assessed, 47% scored 10 on the visual learning scale. Overall, 74% scored higher than 8 on the scale. Conclusion: The use of CMAP tools® software was effective in helping students understand concepts related to skeletal muscle components and contraction.

Efficiency of solar devices is affected by several factors such as, devices surface reflection and the energy emitted in the ultraviolet and infrared regions, which are not harnessed by the cell, are among the main causes. To reduce these losses, we propose the use of rare-earth doped anti-reflection coatings. Erbium doped forsterite (Mg2SiO4:Er3+) thin films were synthesized in order to bind the anti-reflective property of forsterite films with the upconversion property of erbium ion. For the first time in literature, Mg2SiO4:Er3+ optical activity in the visible range with excitation at 1470 nm is presented. Single and double layers anti-reflective coating models, with forsterite as coating material, were simulated. The single layer model was compared to experimental data presenting elevated accordance. The coating application on silicon wafer leaded to a light absorption enhancement over 80% in the visible spectrum. The dopant influence on the films optical behavior was also studied indicating that despite the presence of erbium, the fosterite films preserved their anti-reflectivity. Moreover, the coatings were analyzed through chemical and mechanical resistance tests, indicating elevated scratch resistance (over 500 mN) and chemical stability at high humidity and corrosive environments. Mg2SiO4:Er3+ films revealed to be a promising anti-reflection coating for increasing commercial silicon-based solar cells efficiency.

Novel approaches for high contrast, deep tissue, in vivo fluorescence biomedical imaging are based on infrared-emitting nanoparticles working in the so-called second biological window (1,000–1,400 nm). This allows for the acquisition of high resolution, deep tissue images due to the partial transparency of tissues in this particular spectral range. In addition, the optical excitation with low energy (infrared) photons also leads to a drastic reduction in the contribution of autofluorescence to the in vivo image. Nevertheless, as is demonstrated here, working solely in this biological window does not ensure a complete removal of autofluorescence as the specimen’s diet shows a remarkable infrared fluorescence that extends up to 1,100 nm. In this work, we show how the 1,340 nm emission band of Nd3+ ions embedded in SrF2 nanoparticles can be used to produce autofluorescence free, high contrast in vivo fluorescence images. It is also demonstrated that the complete removal of the food-related infrared autofluorescence is imperative for the development of reliable biodistribution studies.

The following article appeared in Applied Physics Letters 104.5 (2014): 053703 and may be found at http://scitation.aip.org/content/aip/journal/apl/104/5/10.1063/1.4862968, In this work, we demonstrate how LaF3 nanoparticles activated with large concentrations (up to 25%) of Nd3+ ions can simultaneously operate as biologically compatible efficient nanoheaters and fluorescent nanothermometers under single beam (808nm) infrared laser excitation. Nd 3+:LaF3 nanoparticles emerge as unique multifunctional agents that could constitute the first step towards the future development of advanced platforms capable of simultaneous deep tissue fluorescence bio-imaging and controlled photo-thermal therapies., This work was supported by the Spanish Ministerio de Educación y Ciencia (MAT2010-16161 and MAT2010-21270-C04-02), by Brazilian Agencies PRONEX/FAPEAL (Project No. 2009-09-006), by FINEP (Financiadora de Estudos e Projetos), by CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico, Grant INCT NANO(BIO)SIMES). Uéslen Rocha is supported by a graduate studentship from CAPES and actually by a PDSECAPES program developed in the Universidad Autónoma de Madrid through the Project No. 5990-11-4, Spain. Dr.K.U.K. is supported by a Post Doctoral Fellowship grant of the Programa Nacional de Pos-Doutramento (PNPD/CAPES) at the Universidade Federal de Alagoas (UFAL) through the Project No. 02727/09-9.

Bile duct injuries occur with a frequency of 1 to 5 per 1000 cases as a result of an increase in the number of procedures performed. Elderly patients have more severe lithiasis- related diseases than the younger population. This fact increases the likelihood of conversion from laparoscopic to open surgery, and the probability of injury. We report the results of bile duct reconstruction after injury in these patients. Setting: A tertiary care academic university hospital. Methods: The files of patients over 65 years of age who had biliary tract reconstruction after iatrogenic injury were retrospectively reviewed. Post operative results, quality of life and failures from the repair were analyzed. Results: 20 patients over the age of 65 were referred for biliary tract reconstructive surgery over a ten year period. Mean age was 71 (65 – 83). Nineteen cases were referred from other hospitals. Fourteen cases (60%) had comorbidities (type 2 diabetes mellitus, systemic hypertension). All patients were treated by means of Roux en Y hepatojejunostomy. No operative morbility was recorded and only one major complication (abdominal collection) was found. Two long term mortalities unrelated to surgery were found. Treatment success (as defined by the Johns Hopkins criteria) was obtained in 17 cases (85%) and only one patient (5%) required reoperation two years after the initial attempt. Conclusions: Elderly patients that survive biliary injury and are reconstructed have long-term results comparable to the younger population; Roux en Y hepatojejunostomy offers the best surgical choice.

The following article appeared in Journal of Applied Physics 111.2 (2012): 023513 and may be found at http://scitation.aip.org/content/aip/journal/jap/111/2/10.1063/1.3676251, Semiconductor quantum dots of few nanometers have demonstrated a great potential for bioimaging. The size determines the emitted color, but it is also expected to play an important role in the image brightness. In this work, the size dependence of the fluorescence quantum yield of the highly thermal sensitive CdTe quantum dots has been systematically investigated by thermal lens spectroscopy. It has been found that an optimum quantum yield is reached for 3.8-nm quantum dots. The presence of this optimum size has been corroborated in both one-photon excited fluorescence experiments and two-photon fluorescence microscopy of dot-incubated cancer cells. Combination of quantum yield and fluorescence decay time measurements supports that the existence of this optimum size emerges from the interplay between the frequency-dependent radiative emission rate and the size-dependent coupling strength between bulk excitons and surface trapping states., This work was supported by the Universidad Autónoma de Madrid and Comunidad Autónoma de Madrid (Projects CCG087-UAM/MAT-4434 and 2009/MAT-1756), by the Spanish Ministerio de Educacion y Ciencia (MAT 2010-16161), by a Banco Santander CEAL-UAM project, and by the Brazilian agencies CAPES, CNPq, and FAPEAL (through the PRONEX 2009-09-006).

A lightweight concrete using granulated corn cob (without corn) as an aggregate is proposed in this research work. Taking into account that corn cob, after extracting the corn, is generally considered an agricultural waste, an interesting economic and sustainable benefit may result by using it as a building material. Therefore, it can be an alternative sustainable lightweight aggregate solution in comparison to the most currently applied ones such as expanded clay, particles of cork, particles of expanded polystyrene (EPS), among others. The density, the compressive strength and the thermal insulation properties of a corn cob concrete were experimentally quantified. An expanded clay concrete was also studied as reference. The main results obtained are presented and discussed showing that the proposed corn cob concrete may have the adequate material properties required for a lightweight concrete for non-structural application purposes.

In this work we present a comprehensive study of the spectroscopic and thermo-optical properties of a set of samples with composition xNd(2)O(3)-(5-x)Y(2)O(3-)40CaO-55B(2)O(3) (0 ≤ x ≤ 1.0 mol%). Their fluorescence quantum efficiency (η) values were determined using the thermal lens technique and the dependence on the ionic concentration was analyzed in terms of energy transfer processes, based on the Förster-Dexter model of multipolar ion-ion interactions. A maximum η = 0.54 was found to be substantially higher than for yttrium aluminoborate crystals and glasses with comparable Nd(3+) content. As for the thermo-optical properties of yttrium calcium borate, they are comparable to other well-known laser glasses. The obtained energy transfer microparameters and the weak dependence of η on the Nd(3+) concentration with a high optimum Nd(3+) concentration put this system as a strong candidate for photonics applications.

Tesis doctoral inédita cotutelada por la Universidade Federal de Alagoas de Brasil y la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Física de Materiales. Fecha de lectura: 13-03-2020

Tesis Doctoral inédita cotutelada por la Universidade Federal de Alagoas de Brasil y la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Física de Materiales. Fecha de lectura: 17-12-2018, In this thesis, the use of core/shell engineering for the synthesis of fluorescent nanoparticles (NPs) capable of operating as nanothermometers, nanoheaters and/or contrast agents for fluorescence imaging in small animal models is explored. The materials here studied – rare-earth (Nd3+, Yb3+, Tm3+ and/or Er3+) doped NPs and PbS/CdS/ZnS quantum dots (QDs) – presented emission and/or excitation bands in the so-called biological windows, where light penetration into tissues is maximal, allowing for ex vivo and in vivo applications. It was demonstrated that the spatial separation between the rare-earth ions, achieved by the core/shell nano-engineering, resulted not only in a considerable improvement on the values of thermo-optical parameters such as the light-heat conversion efficiency and the relative thermal sensitivity, but also on a multi-functionality of the nanosystems. As a consequence, innovative applications in nanothermometry were successfully accomplished when developing this thesis. Among those applications, one can mention: the study in real time of the thermal dynamics of an in vivo tissue, the detection and monitoring of cardiovascular diseases and the recording of in vivo thermal images and videos at a subcutaneous level by means of a ratiometric approach. The results here presented open up avenues for new diagnosis and control techniques that can revolutionize the current methods found in biomedicine

Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-12-14T19:59:05Z No. of bitstreams: 1 NavadeepShrivastava.pdf: 11699915 bytes, checksum: 24fa347cc7189c2c4ebc46fe265c57f4 (MD5) Made available in DSpace on 2017-12-14T19:59:05Z (GMT). No. of bitstreams: 1 NavadeepShrivastava.pdf: 11699915 bytes, checksum: 24fa347cc7189c2c4ebc46fe265c57f4 (MD5) Previous issue date: 2017-01-12 CAPES FAPEMA CNPq LNNano-CNPEM Bifunctional nanomaterials have exhibited potentially promising physico-chemical properties which can revolutionize and transform the landscape from bioclinical industry to next generation advance devices. In particular, colloidal nanoparticles have been extensively investigated as probes in biomedical and devices industries due to their unique size dependent electronic, optical, and magnetic properties amongst all possible building blocks of bifunctional materials. Superparamagentic ironoxide nanoparticles open up a new avenue to the development and application of photonic technologies such as novel optical devices and bioclinical research by coupling with fluorescent materials especialy rare eath ions. Rare earth nanomaterials, which feature long lived intermediate energy levels and intraconfigurational 4f-4f transitions, are promising supporters for photon conversion in a wide range of fluoride hosts covering UV to IR region and are preferred over other fluorescent materials due to their large stokes shift, sharp emission spectra, long lifetime, multiphoton and up/downconversion excitation-emission preocesses. Owing to the unusual magnetic and optical properties associated with f-electrons, rare-earth elements are very suitable for creating bifunctional materials themselves at platform of nanoscale by employing the unique magnetic and up/downconversion luminescence properties integrated within single particles upon proper choices of particle matrix and dopants. In the present thesis, we have discussed (i) bifunctionality of triply doped multicolor tuned photonic nanomaterials based on LaF3:Ce3+ ,Gd3+,Eu2/3+ prepared by polyol synthesis; (ii) green emitting triply doped bifunctional iron-oxide/ZnS@LaF3:Ce3+,Gd3+,Tb3+ nanocomposites with efficient optical and magnetic functionality, obtained using co-precipitation method; (iii) red/green emitting binary doped optical-magnetic up/downconverting β-NaGdF4:RE3+ and iron-oxide/SiO2/NaGdF4:RE3+ (RE= Ce, Eu; Yb, Er) nanoparticles using microwave assisted thermolysis; and (iv) scintillating response due to neutrons for colloidal nanoparticles of LaF3:Ce3+ ,Gd3+,Eu2/3+. The prepared materials have been well characterized structurally using powder x-ray diffraction, transmission elecron microscopy techniques and Fourier transform infrared spectroscopy. The excitation/emission (photoluminescence) investigations, time decay analysis of emitting level, and proposed energy transfer mechanism for different nanomaterials have been carried out and result in exciting optical characteristics due to f-f transition (Eu3+, Tb3+, Er3+) and f-d transitions (Ce3+, Eu2+) of rare earth ions. Furthermore, the magnetic characteristics of the materials were evaluated and materials containing iron-oxide as part of nanoentity displayed superparamgnetic nature whereas LaF3:RE3+ and NaGdF4:RE3+ showed their typical paramagnetic characteritcs at room temperature. Additionally, colloidal LaF3:Ce3+,Gd3+,Eu2/3+ nanoparticles proved to be efficient nanoscintillators for neutron detection, under irraditon of 241AmBe source. The result encouraged to test other nanomaterials under high energy irradiation and to further design of commercial nanoscintillators. The intense optical and sufficient magnetic peculiarities of the mentioned materials are probably quite appealing for magnetic-optical imaging (X-ray/γ-ray or NIR-Laser excitation), magnetic light-converting molecular devices and smart magnetic and radiationfield detection. Nanomateriais bifuncionais exibem propriedades fisico-químicas potencialmente promissoras que podem revolucionar e transformar o panorama da indústria bioclínica e da próxima geração de dispositivos avançados. Em particular, as nanopartículas coloidais têm sido amplamente investigadas como sondas em indústrias biomédicas e também como dispositivos devido às suas propriedades eletrônicas, ópticas e magnéticas dependentes do tamanho único entre todos as possíveis unidades básicas dos materiais bifuncionais. As nanopartículas de óxido de ferro superparamágneticas abrem uma nova via para o desenvolvimento e aplicação de tecnologias fotônicas, como novos dispositivos opticos e pesquisas bioclínicas, acoplando materiais fluorescentes, especialmente íons de terras raras. Os nanomateriais de terras raras, que apresentam níveis de energia intermediários de longa duração e transições intraconfiguracionais 4f-4f, são materiais promissores para a conversão de fótons em uma ampla gama de matrizes de fluoreto que cobrem a região entre o ultra violeta e o infra-vermelho e são preferidos em relação a outros materiais fluorescentes devido ao grande deslocamento Stokes, acentuado espectro de emissão, longo tempo de vida, emissão multi-fotônica e processos de excitação/emissão de conversão para os modos ascendentes/descendentes. Devido as propriedades magnéticas e opticas incomuns associadas aos elétrons 4f, os elementos terras raras são muito adequados para a criação de materiais bifuncionais em nanoescala, empregando as propriedades únicas magnéticas e de luminescência por modos ascendentes/descendentes integradas em uma única partícula, dependendo da escolha apropriada da partícula matriz e dos dopantes.Neste trabalho, discutimos (i) a bifuncionalidade do nanomaterials fotônicos ajustados e dopados com multicores com base em LaF3:Ce3+,Gd3+,Eu2/3+ preparados pela síntese de polióis; (ii) materiais nanocompósitos triplamente dopados de óxido-de-ferro/ZnS@LaF3:Ce3+,Gd3+,Tb3+ bifuncionais que emitem na cor verde com eficiente funcionalidade optica e magnética, obtidos usando o método de co-precipitação; (iii) materiais magneto-opticos dopados binários na forma de nanopartículas de β-NaGdF4:RE3+ e óxido-de- ferro/SiO2/NaGdF4:RE3+ (RE = Ce, Eu, e Yb, Er) que emtem no verde e vermelho nos modos ascendente e descendente utilizando micro-ondas assistida por termólise (iv) detecção cintilante por radiação de nêutrons para nanopartículas coloidais de LaF3:Ce3+,Gd3+,Eu2/3+. Os materiais preparados foram caracterizados estruturalmente usando difração de Raios-X, técnicas de microscopia de eletrônica de transmissão e espectroscopia de transformada de Fourier no infravermelho (FTIR). As investigações de excitação/ e emissão (fotoluminescência), a análise de degradação do tempo de vida do nível de emissão e o mecanismo de transferência de energia proposto para diferentes nanomateriais foram realizados e resultaram em características opticas interessantes devido a transições f-f (Eu3+, Tb3+ , Er3+) e f-d (Ce3+, Eu2+) de íons de terras raras. Além disso, as características magnéticas foram avaliadas e os materiais que contêm óxido de ferro como parte da nano-unicidade apresentaram natureza superparamégnetica, enquanto que LaF3: RE3+ e NaGdF4: RE 3+ mostraram características típicas paramagnéticas à temperatura ambiente. Adicionalmente, as nanopartículas coloidais LaF3:Ce3+,Gd3+,Eu2/3+ provaram ser nanoscintiladores eficientes para detecção de nêutrons, sob irradiação de fonte de 241AmBe. O resultado motiva a testar outros nanomateriais sob irradiação de alta energia e a posterior elaboração de nanoscintiladores comerciais. As fortes características opticas e magnéticas (excitação de Raios-X, Raios-γ e Laser), dispositivos moleculares magnéticos de conversão de luz e detecção inteligente de campo magnético e de campo de radiação.