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The rapid development of new materials and their application in an extremely wide variety of research and technological fields has lead to the request of increasingly sophisticated characterization methods. In particular residual stress measurements by neutron diffraction, small angle scattering of X-rays and neutrons, as well as 3D imaging techniques with spatial resolution at the micron or even sub-micron scale, like micro-and nano-computerized tomography, have gained a great relevance in recent years.Residual stresses are autobalancing stresses existing in a free body not submitted to any external surface force. Several manufacturing processes, as well as thermal and mechanical treatments, leave residual stresses within the components. Bragg diffraction of X-rays and neutrons can be used to determine residual elastic strains (and then residual stresses by knowing the material elastic constants) in a non-destructive way. Small Angle Scattering of neutrons or X-rays, complementary to Transmission Electron Microscopy, allows the determination of structural features such as volume fraction, specific surface and size distribution of inhomogeneities embedded in a matrix, in a huge variety of materials of industrial interest. X-ray microtomography is similar to conventional Computed Tomography employed in Medicine, allowing 3D imaging of the investigated samples, but with a much higher spatial resolution, down to the sub-micron scale. Some examples of applications of the experimental techniques mentioned above are described and discussed.

In the last decades, very significant advances have been made for what concerns bone and joint substitution and in the repair and regeneration of bone defects. Though some strong requirements are still to be met, biomaterials for these purposes have known an impressive evolution, for what concerns their mechanical behaviour, their bioresorbability and finally their capability to generate new bone tissue in a stable way in long periods. The validation of such materials necessarily depends on a suitable characterization of their properties. In this article a brief review of some works in this field, carried out by the authors’ research group, is presented. It was shown in particular how advanced experimental methods, such as synchrotron radiation µCT and synchrotron radiation diffraction can offer very important information, can be not only complementary methods to more standard techniques (electron microscopy, X-ray diffraction), but can also offer the possibility to measure parameters that cannot be obtained otherwise.

Background: Alveolar bone defects are usually the main concern when planning implant treatments for the appropriate oral rehabilitation of patients. To improve local conditions and achieve implant treatments, there are several methods used for increasing bone volume, among which one of the most successful, versatile, and effective is considered to be guided bone regeneration. The aim of this demonstrative study was to propose an innovative analysis protocol for the evaluation of the effect of photobiomodulation on the bone regeneration process, using rat calvarial defects of 5 mm in diameter, filled with xenograft, covered with collagen membrane, and then exposed to laser radiation. Methods: The animals were sacrificed at different points in time (i.e., after 14, 21, and 30 days). Samples of identical dimensions were harvested in order to compare the results obtained after different periods of healing. The analysis was performed by cross-linking the information obtained using histology and high-resolution synchrotron-based tomography on the same samples. A comparison was made with both the negative control (NC) group (with a bone defect which was left for spontaneous healing), and the positive control (PC) group (in which the bone defects were filled with xenografts and collagen membrane without receiving laser treatment). Results: We demonstrated that using photobiomodulation provides a better healing effect than when receiving only the support of the biomaterial. This effect has been evident for short times treatments, i.e., during the first 14 days after surgery. Conclusion: The proposed analysis protocol was effective in detecting the presence of higher quantities of bone volumes under remodeling after photobiomodulation with respect to the exclusive bone regeneration guided by the xenograft.

Oral squamous cell carcinoma (OSCC) constitutes 90% of oral cancer. Early detection is a cornerstone to improve survival and to reduce diagnostic delay. We propose optical coherence tomography (OCT), as a non-invasive diagnosis method. OCT represents a new high-resolution optical technique that permits 3D, real-time imaging of near surface abnormalities in complex tissues. In the present study half of the excisional biopsy was directed to the pathologist and the other half was assigned for OCT and Micro-CT investigation. For the OCT imaging it was used an OCT prototype (1300 nm), Synchrotron Radiation Micro-CT and histopathology validated the results. Areas of OSCC of the buccal mucosa were identified in the OCT images by the disruption of the basement membrane, an epithelial layer that was highly variable in thickness, with areas of erosion, extensive epithelial down-growth and invasion into the sub-epithelial layers. In this respect, OCT seems to be a highly promising imaging modality.

Introduction.The osteoconductive materials are very important in the bone regeneration procedures. The aim of this paper is to evaluate the interface between the old bone and the new regenerated one.Materials and methods. Ten rat femurs were used for this investigation. Under strict supervision, ten holes were drilled in the rat femurs and then filled with Bio-Oss® (Geistlich, Wolhusen, Switzerland). matrix. The samples were obtained after 3 month from the procedure and were investigated by MicroCT. A common Synchrotron Radiation X-Ray micro-CT experiment was performed at the SYRMEP Beamline of the ELETTRA Synchrotron Radiation Facility (Trieste, Italy). The 900 radiographic projections were acquired with a beam energy of 29 keV over 180° (0.2 degrees step) with a resolution of 9μm. A sample – detector distance of 16 cm was considered. The tomographic reconstruction was performed by means of the common filtered back-projection method. The 3D reconstructions were obtained at the University of Ancona using specific software, VGStudio Max.Results:The synchrotron offered 900 microCT files that were used to make the 3D reconstruction of the bone. After tomographic reconstruction, 3D renderings of obtained data may be made by electronically stacking up the slices. These 3D volumes may be also sectioned in arbitrary ways, zoomed and rotated in order to locate better the individual details. While the 2D slice images and 3D renderings are very useful for making qualitative observations of an internal concrete structure, the real benefit is the quantitative information that can be extracted from the 3D datasets.The reconstructions allow observing the normal rat bone, the new regenerated bone and also the rest of nonactivated matrix of Bio-Oss® (Geistlich, Wolhusen, Switzerland). The system permits to make measurements in order to quantify the volume of the new bone formation and also the status of the bone defect, in order to define the healing process.Conclusions:The MicroCT method proves to be an important imagistic tool for nondestructive evaluation of the interface between the new regenerated bone and the old one from the rat femurs. This method allows numerical quantification of the new regenerated bone and define the healing bone process.

Lipocalin-2 (LCN2) is a protein largely expressed in many tissues, associated with different biological phenomena such as cellular differentiation, inflammation and cancer acting as a survival/apoptotic signal. We found that LCN2 was expressed during osteoblast differentiation and we generated transgenic (Tg) mice over-expressing LCN2 in bone. Tg mice were smaller and presented bone microarchitectural changes in both endochondral and intramembranous bones. In particular, Tg bones displayed a thinner layer of cortical bone and a decreased trabecular number. Osteoblast bone matrix deposition was reduced and osteoblast differentiation was slowed-down. Differences were also observed in the growth plate of young transgenic mice where chondrocyte displayed a more immature phenotype and a lower proliferation rate. In bone marrow cell cultures from transgenic mice, the number of osteoclast progenitors was increased whereas in vivo it was increased the number of mature osteoclasts expressing tartrate-resistant acid phosphatase (TRAP). Finally, while osteoprotegerin (OPG) levels remained unchanged, the expression of the conventional receptor activator of nuclear factor-κB ligand (RANKL) and of the IL-6 was enhanced in Tg mice. In conclusion, we found that LCN2 plays a role in bone development and turnover having both a negative effect on bone formation, by affecting growth plate development and interfering with osteoblast differentiation, and a positive effect on bone resorption by enhancing osteoclast compartment.

In orthodontics, the scientific interest regarding adhesion is focused on optimizing adherents: metallic or aesthetic bracket base conditioning, creating aesthetic brackets with improved mechanical properties, enamel conditioning and artificial surface conditioning (aesthetic veneers and crowns). In order to investigate the interfaces between adherents there are several invasive (destructive) methods such as tensile bond strength tests, shear bond strength tests and microleakage tests.

Background In recent years, there has been interest on the fabrication of systems using particulates or block-based approach for bone tissue engineering (TE) scaffolds, possessing porous interconnected structures. In fact, these particular morphologies greatly increase the surface area for more chemical and biological reactions to take place. Purpose This study was designed to demonstrate the unique capability of the synchrotron radiation x-ray microtomography (micro-CT) in offering an advanced characterization of coralline-derived (Biocoral) biomaterials placed in human maxillary defects as it allows, in a nondestructive way, a complete, precise, and high-resolution three-dimensional analysis of their microstructural parameters. Moreover, the comparison between Biocoral and other biomaterials was explored to understand the mechanism of their biological behavior as bone substitute. Materials and Methods Implant survival, bone regeneration, graft resorption, neovascularization, and morphometric parameters (including anisotropy and connectivity index of the structures) were evaluated by micro-CT in Biocoral and the other biomaterials after 6 to 7 months from implantation in human maxillary bone defects. Results After the in vivo tests, a huge amount of bone was detected in the retrieved Biocoral-based samples, coupled with a good rate of biomaterial resorption and the formation of a homogeneous and rich net of new vessels. The morphometric parameters were comparable to those obtained in the biphasic calcium phosphate-based control, with the exception of the connectivity index for which this control exhibited the most well-connected structure. This last result, together with those referred to the poor performances of the β-tricalcium phosphate block-based sample, suggests that the particular scaffold morphology may play a role in the hunt the optimal scaffold structure to be implanted. Conclusion In this limited study, implant success rate seems not strictly dependent on the biomaterial that is used, but on the scaffold morphology. Micro-CT technique was demonstrated to play a fundamental role in advanced characterization of bone TE constructs.

The recent introduction of stem cells in cardiology provides new tools in understanding the regenerative processes of the normal and pathological heart and has opened a search for new therapeutic strategies. Recent published reports have contributed to identifying possible cellular therapy approaches to generate new myocardium, involving transcoronary and intramyocardial injection of progenitor cells. However, one of the limiting factors in the overall interpretation of clinical results obtained by cell therapy is represented by the lack of three-dimensional (3D) high-resolution methods for the visualization of the injected cells and their fate within the myocardium. This work shows that X-ray computed microtomography may offer the unique possibility of detecting, with high definition and resolution and in ex vivo conditions, the 3D spatial distribution of rat cardiac progenitor cells, labelled with iron oxide nanoparticles, inside the infarcted rat heart early after injection. The obtained 3D images represent a very innovative progress as compared to experimental two-dimensional (2D) histological analysis, which requires time-consuming energies for image reconstruction in order to provide the overall distribution of rat clonogenic cells within the heart. Through microtomography, we were able to observe in 3D the presence of these cells within damaged cardiac tissue, with important structural details that are difficult to visualize by conventional bidimensional imaging techniques. This new 3D-imaging approach appears to be an important way to investigate the cellular events involved in cardiac regeneration and represents a promising tool for future clinical applications. Copyright © 2011 John Wiley & Sons, Ltd.

In order to improve oxidation resistance of TIMETAL834, protective coating based on γ-TiAl intermetallic alloy with Si and Ag admixtures was produced by magnetron sputtering. Analytical scanning and transmission electron microscopy were used for detailed analyses of a microstructure and chemical composition of the coating. It was found that the coating contains two sublayers with different microstructure and morphology. Energy-dispersive synchrotron radiation diffraction was applied for stress analysis. The results show that there are tensile residual stresses present within the TIMETAL834 substrate and compressive residual stresses within the γ-TiAl sublayer. It was established that the surface treatment applied in this work essentially improves the alloy oxidation resistance.

The present study utilized nanostructured hydroxyapatite (HA) granules for plasma-sprayed coating on a titanium alloy (Ti–6Al–4V). The initial nanostructured HA powder was synthesized in aqueous solutions of gelatin. The effect of gelatin solutions of variable concentration on the particles size was investigated. The nanostructured HA particles were formed into the porous granules using a liquid immiscibility effect. Consolidation of these powders at various temperatures was carried out. The phase composition, structure, residual stresses and adhesive bond strengths of the obtained coatings from the developed feedstock were investigated by X-ray diffraction, scanning electron microscopy and mechanical tests. X-ray diffraction showed that all the HA coating is a fully crystalline phase without any decomposition. The coatings exhibited a unique phase construction and a fairly low tensile residual stress. The adhesive bond strength of a HA coating was achieved up to 37 ± 2.2 MPa. Tensile failure analysis has suggested that the failure took place at the coating/substrate interface. It is expected that the developed coatings will have much longer service life as compared to the existing ones.

The microstructure and phase composition of the protective Ti48Al2Ag coating produced on Timetal 834 by magnetron sputtering have been examined by scanning and analytical transmission electron microscopy (SEM, TEM). TEM investigations revealed that Ti48Al2Ag coating consists of two sublayers: outer columnar γ-TiAl and amorphous Ti5Al3O2. Energy-dispersive synchrotron radiation diffraction was applied for stress analysis. The results show that there are tensile residual stresses present within the Timetal 834 substrate and compressive residual stresses within the γ-TiAl sublayer.

Introduction Successful bone regeneration using both granules and blocks of biphasic calcium phosphate materials has been reported in the recent literature, in some clinical applications for maxillary sinus elevation, but the long-term kinetics of bone regeneration has still not been fully investigated. Materials and methods Twenty-four bilateral sinus augmentation procedures were performed and grafted with hydroxyapatite/β-tricalcium phosphate 30/70, 12 with granules and 12 with blocks. The samples were retrieved at different time points and were evaluated for bone regeneration, graft resorption, neovascularization, and morphometric parameters by computed microtomography and histology. Results A large amount of newly formed bone was detected in the retrieved specimens, together with a good rate of biomaterial resorption and the formation of a homogeneous and rich net of new vessels. The morphometric values were comparable at 5/6 months from grafting but, 9 months after grafting, revealed that the block-based specimens mimicked slightly better than granule-based samples the healthy native bone of the maxillary site. Conclusion The scaffold morphology was confirmed to influence the long-term kinetics of bone regeneration.

Background and Objective In the present study, the early stages of in vitro bone formation in collagenated porcine scaffolds cultured with human periodontal ligament cells were investigated. The comparison between the osteogenic potential of this structure in basal and differentiating culture media was explored to predict the mechanism of its biological behavior as graft in human defect. Results were validated by synchrotron radiation X-Ray phase contrast computed microtomography (micro-CT). As the periodontal disease plays a key role in systemic and oral diseases, it is crucial to find advanced therapeutic clinical interventions to repair periodontal defects. This has been recently explored using cells and tissues developed in vitro that should ideally be immunologically, functionally, structurally and mechanically identical to the native tissue. Material and Methods In vitro cultures of human periodontal ligament cells, easily obtained by scraping of alveolar crestal and horizontal fibers of the periodontal ligament, were seeded on to collagenated porcine blocks constituted by natural cancellous and cortical bone. 3D images were obtained by synchrotron radiation micro-CT and processed with a phase-retrieval algorithm based on the transport of intensity equation. Results Starting from the second week of culture, newly formed mineralized bone was detected in all the scaffolds, both in basal and differentiating media. Bone mineralization was proved to occur preferentially in the trabecular portion and in differentiating media. Conclusion The chosen method, supported by phase contrast micro-CT analysis, successfully and quantitatively monitored the early stages of bone formation and the rate of the bioscaffold resorption in basal and differentiating culture media.

The treatment of carious lesions requires removal of affected dental tissue thus creating cavities that are to be filled with dedicated materials. There are several methods known which are used to assess the quality of direct dental restorations, but most of them are invasive. Optical tomographic techniques are of particular importance in the medical imaging field, because these techniques can provide non-invasive diagnostic images. Using an en-face version of OCT, we have recently demonstrated real time thorough evaluation of quality of dental fillings. The major aim of this study was to analyses the optical performance of adhesives modified with zirconia particles in different concentrations in order to improve the contrast of OCT imaging of the interface between the tooth structure, adhesive and composite resin. The OCT investigations were validated by micro CT using synchrotron radiation. The OCT Swept Source is a valuable investigation tool for the clinical evaluation of class II direct composite restorations. The unmodified adhesive layer shows poor contrast on regular OCT investigations. Adding zirconia particles to the adhesive layer provides a better scattering which allows a better characterization and quantification of direct restorations. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

True Baroque organ music can only come back to life in the 21st century by developing Cu-based alloys and implementing them in the organ reed pipes. Reed pipes contain a vibrating part, the brass tongue that crucially influences its sound. Energy dispersive synchrotron X-ray diffraction has been performed in order to investigate residual stresses in the tongues. The in depth analysis gives us an important indication on the processes the tongues were submitted to during their manufacturing: hammering, annealing, filing to the neat thickness, curving of the tongues. A biaxial stress state in the organ tongues was considered. The residual stress values and behaviour were correlated to the manufacturing processes.

Neutron and synchrotron radiation techniques are very powerful non-destructive methods for the characterisation of a wide variety of materials. In particular, neutron and synchrotron radiation diffraction is nowadays widely used for the evaluation of residual stresses induced by thermal and mechanical treatments in materials and components for industrial applications. By small angle neutron scattering (SANS), microstructural features induced by thermomechanical treatments, such as precipitation and cavitation, can be investigated from a quantitative point of view (determination of size distributions, volume fraction). A review is presented of the techniques mentioned above, and some applications to materials for technological applications will be presented.

Neutron Diffraction shows that plastic pre-deformation and heat treatments have opposite effects on the residual stress in Al–SiCp composites. The thermal micro residual stress is relaxed or even reversed by pre-strains above 0.2%, but restored by heat treatments. The sense of relaxation changes above 400 °C (the mixing temperature).

The residual stresses for different Ti + hydroxyapatite (HA) compositional gradient coatings on Ti6Al4V substrates were analysed by means of synchrotron radiation measurements. The samples were obtained by plasma spraying using different plasma spraying parameters for the different layers and coatings. A finite element model (FEM) was developed and a comparison between the theoretical FEM predictions and the experimental values was done. The influence of the plasma spraying parameters on the stresses was studied. The stress in a pure HA coating on Ti6Al4V substrate was measured and compared with those in the HA layers of the compositional gradient coatings.

Данный обзор посвящен результатам исследований ex vivo структур полости рта с помощью оптической когерентной томографии (ОКТ), которые демонстрируют огромный потенциал технологии для прижизненной визуализации тканей полости рта. ОКТ-технология может создавать высокоразрешающие кросс-секционные и анфасные изображения внутренней архитектуры исследуемых образцов (глубиной до 2-3 мм). Для этой цели используются анфасные системы с временным и спектральным сканированием. В обзоре рассмотрены возможности оценки с помощью ОКТ различных стоматологических процессов: стоматологической абфракции и стирания, дефектов материалов и микроутечки в зоне контакта пломбы и зуба, диска височно-нижнечелюстного сустава, качества крепления брекетов к твердой ткани зубов, ортопедической реставрации и микроутечки в месте контакта протеза, корневых каналов, наличия или отсутствия верхушечных микроутечек, а также контактного остеогенеза зубных имплантатов и материалов для костной пластики. ОКТ показывает внутренние особенности исследуемого материала с большей чувствительностью, чем другие существующие диагностические методы. Обзор отражает главным образом опыт исследований нашей группы и представляет изображения, полученные с помощью нашей ОКТ-системы. Исследования демонстрируют эффективность ОКТ как полезного метода в стоматологической практике, а также в научных исследованиях. Поскольку ОКТ является неинвазивным методом, ее можно использовать для мягких тканей. Применение как временного, так и спектрального сканирования области подтверждает уникальные возможности ОКТ. Предполагается, что для переносных приборов принцип перестраиваемого лазера (как одна из возможностей спектральной ОКТ) будет преобладать ввиду его высокой скорости, которая позволяет уменьшить искажающие эффекты, вызванные непроизвольными движениями кисти исследователя и движениями пациента. Для исследования поперечных срезов с высокой разрешающей способностью, особенно в научно-ориентированных исследованиях, предполагается, что анфасная ОКТ в пространственно-временной области продолжит сосуществовать со спиральными ОКТ-методами, дополнительно предлагая низкозатратную быструю анфасную визуализацию и совместимость с динамическим фокусом. Динамический фокус, т.е. одновременная регулировка фокуса и зоны когерентности по глубине, несовместим со спиральной ОКТ и требует повторных изображений с разным фокусом, для того чтобы улучшить поперечное разрешение, или более сложных наконечников с делением оптического пути в предметном плече между путями с разными настройками положения фокуса. В этом отношении анфасная ОКТ в пространственно-временной области представляет собой более дешевый способ получения изображений с высоким поперечным разрешением для статических образцов. Мы показали, что возможны взаимно дополняющие исследования, охватывающие ОКТ и более традиционные методы, такие как конфокальная микроскопия и микрокомпьютерная томография. Предполагается, что в дальнейшем получат развитие методы, основанные на сочетании этих принципов, так как использование по отдельности ограничивает их применение., This review emphasizes the current knowledge related to optical coherence tomography (OCT ) as a non-invasive diagnostic tool to perform ex vivo and showing great potential for in vivo structural imaging of features in the oral cavity. OCT technology can generate high-resolution cross-sectional and en-face images of the internal architecture of the investigated sample (2–3 mm in depth). To this goal, en-face time domain OCT (TD-OCT ) and spectral domain OCT (SD-OCT ) were employed. Topics included in this review refer to OCT non-destructive evaluations of: dental abfraction and attrition, material defects and micro-leakages at the tooth-filling interface, temporal-mandibular joint disc, quality of bracket bonding on dental hard tissue, prosthetic restorations and micro-leakages at prosthetic interfaces, root canals, presence or absence of apical micro-leakages, and osteo-integration of dental implants and of bone grafting materials. OCT revealed internal features of the material investigated with greater sensitivity than current diagnostic methods. We put our research in context with others’ results but the review reflects primarily our joint group experience and it presents images collected with our OCT systems only. The studies demonstrate the viability of OCT as a useful tool in dental medicine practice, as well as in research. Being completely non-invasive, OCT can be extended to soft tissue. Both TD and SD implementations prove the unique capabilities of OCT . For handheld scanning devices it is expected that the swept source principle (as one of the SD possibilities) will prevail, due to its high speed that allows for the reduction of distorting effects caused by the involuntary movements of the hand and of the patient. For high transversal resolution investigations, especially in more research oriented studies, it is expected that en-face TD-OCT will continue to coexist with SD-OCT methods, offering additionally a low cost quick provision of en-face view and compatibility with dynamic focus. Dynamic focus, that is the simultaneous adjustment of focus and coherence gate in depth is incompatible with SD-OCT methods and require repetitions of acquisitions under different focus in order to improve the transversal resolution, or more complex heads with division of the optical path in the object arm along different focus adjustments. In this respect, en-face TD-OCT provides a lower cost alternative to high transversal resolution of static samples. We have shown that complementary studies are possible embracing OCT with more traditional methods, such as confocal microscopy and microCT . Combination of principles is expected to evolve due to their limitations when considered separately.

In recent years, great attention has been devoted to the study and realization of polymeric optical waveguides embedded in printed circuit boards due to the increasing need of transferring large amounts of data at high speed within computer and telecommunication devices. Nonuniform microstructural defects that can be induced during the manufacturing process can dramatically influence the waveguide performance. The synchrotron radiation computed microtomography technique was used to obtain 3-D microstructural information, specifically to observe small defects, such as porosities, in a nondestructive way. Porosity level and pore size range were evaluated.

The experiments here described have been carried out in the framework of a more general research, aiming to develop a set of complementary models to predict the in-service performances of particular reinforced MMC automotive and aeronautical components. As MMC's are highly heterogeneous materials, residual stresses are present both in the matrix and the particles microstructure, prior to any macroscopic loading. They vary with the temperature and with the type and level of loading imposed to the material, and have a strong influence on the mechanical behaviour of MMC's. Neutron and X-ray diffraction measurements have been performed at HMI-BENSC (Berlin, Germany), and LLB (Saclay, France) for the determination of residual stresses in a prototype component an automotive brake drum (AA359+20% SIC). As expected, the results show that in each gauge point the main contribution is generally given by thermal microstresses.

As part of an integral study on operation and safety of centrifuges for food processing and agricultural applications, neutron diffraction measurement was carried out on a bowl (rotor of a centrifuge) to investigate residual stresses due to manufacturing. The bowl was made of duplex stainless steel containing 50 vol% austenite and 50 vol% ferrite. The results reveal high tensile stresses in the austenite phase and high compressive stresses in the ferrite phase. In addition, significant macroscopic stresses were observed in the hoop direction, which decreased with increasing distance from the upper surface of the bowl. The observed residual stresses were attributed to different processes employed during manufacturing.

The problematic elements of bone regenerative materials are represented by their quality control methods. The defects repaired by bone grafting material were evaluated by en face optical coherence tomography and by synchrotron radiation micro-CT. The images obtained by efOCT show defects in some of the investigated samples, at the bone interface with different osteoconductive bone substitutes and we were able to detect gaps as small as 50 μm. After the common synchrotron radiation micro-CT investigations, the slides were reconstructed and the 3D model was obtained. Along with the possibility of navigating inside the structure, one big advantage of this technique was pointed out: the remaining regenerative materials can be separated from the normal bone and the new bone can be visualized. Optical coherence tomography can be performed in vivo and can provide a qualitative and quantitative evaluation of the bone augmentation procedure.

Objective The major aim of this study was to prove the capability of the optical coherence tomography (OCT) method in visualizing the integrity of the adhesive fillings and of the interfaces between the adhesive, tooth structures and composite resin. As zirconium dioxide was added to the composition of the adhesive layer in order to strengthen the backscattered light in the OCT investigation, for a better visualization of the interfaces, the determination of a proper zirconia concentration was another aim of our study. Method Several class II cavities were prepared in human premolars and were filled with dental adhesive containing different zirconia concentrations and light-curing composite resin. Both OCT and synchrotron radiation microtomography (micro-CT) were used to analyse the morphology of the tooth-adhesive-composite interfaces and to investigate the adhesive layer. Results The pore distribution, both at the interfaces level and in the resin, and the analysis of the adhesive layer integrity were obtained. A good agreement between OCT and micro-CT analyses was observed in terms of detecting discontinuities in the adhesive layer. Furthermore, micro-CT showed that zirconia percentages in the adhesive higher than 20 vol.% lead to conglomerates formation, which can negatively influence mechanical properties. Meanwhile, OCT confirmed a factor of 3 for the contrast enhancement when 20% of zirconia was included in the adhesive composition. Significance The present study proved the capability of the OCT method in visualizing the morphology and integrity of zirconia doped tooth adhesive fillings, to be used for a further in vivo tool development. © 2014 Academy of Dental Materials.

Residual stresses have been investigated in samples made of AA6061+22% Al2O3 in order to correlate microstructural characteristics with mechanical performances. In particular, the possible occurrence of a brittle fracture induced by an excessive load transfer from the matrix to the reinforcement was investigated. To this end, macrostresses and microstresses were analysed. A neutron diffraction test on 12 specimens submitted to several loading/unloading conditions at different temperatures was performed. These measurements aimed to establish the optimal temperature for the initial extruded billet in pre-heating stage, before forging the final wheel hub.

none 11 si Abstract Mesenchymal stem cells deriving from dental pulp differentiate into osteoblasts capable of producing bone. In previous studies, we extensively demonstrated that, when seeded on collagen I scaffolds, these cells can be conveniently used for the repair of human mandible defects. Here, we assess the stability and quality of the regenerated bone and vessel network 3 years after the grafting intervention, with conventional procedures and in-line holotomography, an advanced phase-imaging method using synchrotron radiation that offers improved sensitivity toward low-absorbing structures. We found that the regenerated tissue from the graft sites was composed of a fully compact bone with a higher matrix density than control human alveolar spongy bone from the same patient. Thus, the regenerated bone, being entirely compact, is completely different from normal alveolar bone. Although the bone regenerated at the graft sites is not of the proper type found in the mandible, it does seem to have a positive clinical impact. In fact, it creates steadier mandibles, may well increase implant stability, and, additionally, may improve resistance to mechanical, physical, chemical, and pharmacological agents. Giuliani A; Manescu A; Langer M; Rustichelli F; Desiderio V; Paino F; De Rosa A; Laino L; d'Aquino R; Tirino V; Papaccio G. Giuliani A; Manescu A; Langer M; Rustichelli F; Desiderio V; Paino F; De Rosa A; Laino L; d'Aquino R; Tirino V; Papaccio G.

Lipocalin-2 (LCN2) is a protein largely expressed in many tissues, associated with different biological phenomena such as cellular differentiation, inflammation and cancer acting as a survival/apoptotic signal. We found that LCN2 was expressed during osteoblast differentiation and we generated transgenic (Tg) mice over-expressing LCN2 in bone. Tg mice were smaller and presented bone microarchitectural changes in both endochondral and intramembranous bones. In particular, Tg bones displayed a thinner layer of cortical bone and a decreased trabecular number. Osteoblast bone matrix deposition was reduced and osteoblast differentiation was slowed-down. Differences were also observed in the growth plate of young transgenic mice where chondrocyte displayed a more immature phenotype and a lower proliferation rate. In bone marrow cell cultures from transgenic mice, the number of osteoclast progenitors was increased whereas in vivo it was increased the number of mature osteoclasts expressing tartrate-resistant acid phosphatase (TRAP). Finally, while osteoprotegerin (OPG) levels remained unchanged, the expression of the conventional receptor activator of nuclear factor-κB ligand (RANKL) and of the IL-6 was enhanced in Tg mice. In conclusion, we found that LCN2 plays a role in bone development and turnover having both a negative effect on bone formation, by affecting growth plate development and interfering with osteoblast differentiation, and a positive effect on bone resorption by enhancing osteoclast compartment.

Stem cell-based tissue engineering therapies involve the administration of ex vivo manipulated stem cell populations for the purpose of repairing and regenerating damaged or diseased tissue. Currently available methods for monitoring transplanted cells are limited. Monitoring stem cell therapy outcomes requires the development of nondestructive strategies capable to identify the location, magnitude, and duration of cellular survival and fate. The recent development of imaging techniques offers great potential for addressing these critical issues by noninvasively tracking the fate of the transplanted cells. We offer a focused presentation of some examples of the use of imaging techniques connected to the nanotechnological world in research areas related to stem cells. In particular, investigations concerning human stem cell treatment of Duchenne muscular dystrophy in animal models, bioscaffolds for cell proliferation to form muscular fibers, and bone tissue engineering are discussed.

Bone is a complex dynamic tissue undergoing a continuous remodeling process. Gravity is a physical force playing a role in the remodeling and contributing to the maintenance of bone integrity. This article reports an investigation on the alterations of the bone microarchitecture that occurred in wild type (Wt) and pleiotrophin-transgenic (PTN-Tg) mice exposed to a near-zero gravity on the International Space Station (ISS) during the Mice Drawer System (MDS) mission, to date, the longest mice permanence (91 days) in space. The transgenic mouse strain over-expressing pleiotrophin (PTN) in bone was selected because of the PTN positive effects on bone turnover. Wt and PTN-Tg control animals were maintained on Earth either in a MDS payload or in a standard vivarium cage. This study revealed a bone loss during spaceflight in the weight-bearing bones of both strains. For both Tg and Wt a decrease of the trabecular number as well as an increase of the mean trabecular separation was observed after flight, whereas trabecular thickness did not show any significant change. Non weight-bearing bones were not affected. The PTN-Tg mice exposed to normal gravity presented a poorer trabecular organization than Wt mice, but interestingly, the expression of the PTN transgene during the flight resulted in some protection against microgravity's negative effects. Moreover, osteocytes of the Wt mice, but not of Tg mice, acquired a round shape, thus showing for the first time osteocyte space-related morphological alterations in vivo. The analysis of specific bone formation and resorption marker expression suggested that the microgravity-induced bone loss was due to both an increased bone resorption and a decreased bone deposition. Apparently, the PTN transgene protection was the result of a higher osteoblast activity in the flight mice.

We studied the effect of the forming process and thermal treatment on the residual stress state of an extruded metal matrix composite component for aerospace application made of AA2009+25% SiCp. We proceeded in two steps, first studying the material as received (cast billets), then studying components of ideal shape, both as extruded and after stress annealing. The micromechanical model developed in parallel can predict the stress and strain levels in the component. The experimental results obtained on the billet have been used as input for this model. The major output which it was aimed at is an optimized production process. Residual strain scanning and finite-element method simulations give essential information to this end. We observed that, after T4 thermal treatment, the macrostresses relax in the radial and hoop directions while remaining constant in the axial one. Nevertheless, both the tensile microstresses in the Al phase and the compressive microstresses in the SiC phase increase.

An experimental study of the stress field in centrifuges for food processing and for agricultural applications was undertaken. The model, the dimensions and the material of the sample are those of the most recent line of production of the Nuova M.A.I.P. company. The rotor is also one of the largest rotors produced by that firm. The residual strains and stresses were determined by using neutron-diffraction techniques before centrifugation and after centrifugation, to evaluate the evolution of stress induced by centrifuging. The upper part of the rotating bowl is investigated, where the highest stress field during centrifugation is theoretically forecast to occur. A data elaboration aiming at avoiding systematic errors leads to the conclusion that no appreciable residual stress is induced by centrifugation.

Standard production and machining of automotive components is still attractive, although it is not cost-effective if the life of the component has the highest priority. An important parameter to increase the fatigue life of these components is the beneficial introduction of residual stress, especially in the most loaded superficial layers. The aim of the present study is to investigate the residual stress in two steel gears produced from extruded bars cut and machined and then submitted to tempering and nitriding. The results have been compared with those obtained on sintered, nitro-carburised steel gears manufactured using the net-shape forming technique. They show a higher tensile stress level in the bulk of the component with higher carbon and chromium content, that is, a strong influence of nitriding elements. Consequently, in the nitrided layers, the calculated compressive stresses reach relatively high values in an aluminium- and carbon-rich sample. These stresses are sensibly larger than those found in the sintered and nitro-carburised gears, both in the surface and in the bulk.

Deep-water turbidites can hold significant amounts of hydrocarbon reserves. One principal element of reserves estimation is accurate hydrocarbon-in-place determination. In this type of reservoir this value is often difficult to obtain as turbidites are primarily composed of thinly bedded shale and sand beds. When shale and sand lamina are below a tool's vertical resolution, petrophysical properties, for example porosity, are averaged across the shale and sand lamina. Also, resistivity measured by conventional induction devices is biased toward the low-resistivity lamina-component, e.g. shale. This creates the classical low-contrast, low-resistivity predicament where quantification of hydrocarbon saturations and net-to-gross is problematic. Tensor resistivity measurements provide both horizontal and vertical resistivities. The vertical resistivity is more representative of the high-resistivity lamina component, e.g. hydrocarbon-saturated sand. The tensor resistivity measurements are also used to measure large-volume (cubic meters) formation dip and azimuth. Tensor resistivity and nuclear magnetic resonance data were acquired in this deep-water turbidite field. The data were used to provide a more accurate hydrocarbon–in-place value than was obtainable using conventional resistivity measurements in low- contrast, low-resistivity shaly sand formations and to obtain formation dips and azimuths. A methodology directed at the sand- lamina petrophysical properties was used. Work was performed in a total porosity system, using dry-shale density calculated by comparing nuclear magnetic resonance (NMR) porosity data with the neutron-density porosity in shale. By comparing the final analysis with core data, it is shown that the integration of tensor resistivity and NMR data accurately computes oil saturations, sand fraction porosity and net sand thickness. There is a large increase in the calculated cumulative hydrocarbon volume over conventional petrophysical approaches due to increased precision and accuracy in the sand-lamina porosity, hydrocarbon saturation, and net sand thickness determination.

Efficient development and production of hydrocarbon reservoirs depends on the accuracy of the geological and petrophysical models. Historically, these were all basic isotropic models where formation properties do not change with direction. With the recent advancement of measurement technology and processing technqiques, the models started incorporating and integrating variations of petrophysical properties with orientation: anisotropy. Anisotropic petrophysical properties include permeability, acoustic slowness, resistivity, etc. Complex models incorporating variations of petrophysical properties with orientation (anisotropy) are useful for well design and well placement for optimum reservoir drainage, borehole instability and sand production prediction, hydraulic fracturing, surface seismic migration or amplitude-versus-offset studies. Cairn Energy India Pty. Ltd. recorded acoustic and resistivity anisotropy measurements in several of their offshore wells. Acoustic data was processed for azimuthal anisotropy estimation and resistivity data was processed for formation dip, azimuth, horizontal and vertical resistivity. Whilst resistivity information has been used for accurate hydrocarbon saturation computation, the continuous dip and azimuth results provided a geological framework that was used for interpretation of acoustic azimuthal anisotropy results. Integrating both datasets resolved potentially ambiguous interpretation of the azimuthal acoustic anisotropy source. We were able to determine the anisotropy cause (unbalanced stresses in the formation, dipping fracture/faults, highly dipping beds, and shale transverse isotropy with a vertical axis of symmetry [TIV] anisotropy). This presentation shows how an integration of acoustic anisotropy results with resistivity anisotropy results can provide essential information for interpreting and resolving ambiguous causes of acoustic azimuthal anisotropy. This information could be used for avoiding mistakes in well placement and design, reducing sand production and avoiding borehole instability, for well completion planning and several other applications during the life of the field.

Residual stresses are self-equilibrating stresses occurring in a specimen after the original cause of the stress (external forces, heat gradient, mismatch of thermal coefficients during cooling or heating of multiphase materials), has been removed.

Oil was discovered in Jurassic shaly sand reservoirs in central Australia in the mid-1960's. Following the initial discovery numerous fields and a considerable number of wells have been drilled targeting these formations. The oil-bearing formations were deposited under fluviatile-lacustrine conditions with fluviatile, low-energy mixed load the predominant facies type. Historically shaly sand evaluations from conventional logs in the presence of fresh formation waters (salinity in the range of 3 – 4 kppm NaCl equivalents) were problematic due to the subtle and sometimes non-existent resistivity contrast between the hydrocarbon and water-bearing zones. The complex mineralogy of the oil-bearing sandstone is characterised by feldspathic litharenites with volcanic lithic components. The oil varies across the basin but is generally light (API 35 – 50°) with low GOR (under 200 scf/bbl). This paper shows how the acquisition and interpretation of Nuclear Magnetic Resonance (NMR) data provides, not only porosity and pore size distribution, but also identifies and quantifies oil shows in the invaded zone over the logged intervals. Earlier generation NMR tools acquired only one (or a maximum of two) hydrogen spin-echo decay curves. These measurements were inverted into apparent T2 spectrums, which are separated into clay-bound, capillary-bound and movable fluid volumes,. However, this technology does not provide sufficient information to type and quantify reservoir fluids. New-generation NMR tools acquire many more hydrogen spin-echo decay curves. Several spin-echo decay curves focus on the very early T2 decay times, with the goal of improving the response of clay-bound fluids. Other decay curves focus on medium T2 decay times with the target of improving capillary-bound fluid definition. The biggest advantage of the new-generation NMR tools is the acquisition of decay curves at multiple inter-echo times (TE), wait times (TW) and frequency acquisition with additional focus on longer T2 decay times. The acquisition of these long T2 echo decay curves allows for reservoir fluid typing and the quantification of fluid saturation based on 2D-NMR techniques. These techniques invert the multitude of decay curves by treating two NMR properties as independent variables. The main NMR properties are: T2 – Transverse Relaxation Time; T1– Longitudinal Relaxation time, and D – Diffusivity. The inversion process produces 2D maps of two of these NMR properties which are particularly useful at identifying hydrocarbon type and for discerning water from hydrocarbon. NMR data MR ExplorerSM (MReXSM) service was recently acquired in five wells across a number of fields. The acquisition mode was Porosity Permeability Light Oil (PPlo), in which more than twenty spin-echo decay curves are recorded with the target of characterizing light-oil reservoir fluids. The 2D-NMR maps of Diffusivity vs. T2,int were used to quantify the oil volume. This technique produced along-hole maps of diffusivity and intrinsic T2 distributions. Because D and T2 are related to viscosity an estimation of the oil viscosity was also possible.

Neutron and synchrotron radiation techniques are very powerful non-destructive methods for the characterisation of a wide variety of materials. In particular, neutron and synchrotron radiation diffraction is nowadays widely used for the evaluation of residual stresses induced by thermal and mechanical treatments in materials and components for industrial applications. A review is presented of the techniques mentioned above, and some applications to materials for technological applications will be presented.

Andrea Farini,1,* Chiara Villa,1,* Adrian Manescu,2 Fabrizio Fiori,2 Alessandra Giuliani,2 Paola Razini,1 Clementina Sitzia,1 Giulia Del Fraro,1 Marzia Belicchi,1 Mirella Meregalli,1 Franco Rustichelli,2 Yvan Torrente1 1Stem Cell Laboratory, Department of Neurological Sciences, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico di Milano, Centro Dino Ferrari, Università di Milano, Milano, Italy; 2Università Politecnica delle Marche, Di.S.C.O. - Sezione di Biologia, Biochimica e Fisica Ancona, Italy*These authors contributed equally to this paperAbstract: Recently published reports have described possible cellular therapy approaches to regenerate muscle tissues using arterial route delivery. However, the kinetic of distribution of these migratory stem cells within injected animal muscular dystrophy models is unknown. Using living X-ray computed microtomography, we established that intra-arterially injected stem cells traffic to multiple muscle tissues for several hours until their migration within dystrophic muscles. Injected stem cells express multiple traffic molecules, including VLA-4, LFA-1, CD44, and the chemokine receptor CXCR4, which are likely to direct these cells into dystrophic muscles. In fact, the majority of intra-arterially injected stem cells access the muscle tissues not immediately after the injection, but after several rounds of recirculation. We set up a new, living, 3D-imaging approach, which appears to be an important way to investigate the kinetic of distribution of systemically injected stem cells within dystrophic muscle tissues, thereby providing supportive data for future clinical applications.Keywords: iron nanoparticles, micro-CT, CD133+ stem cells, dystrophic muscles

In the hydrocarbon exploration process, after a prospect has been identified and an exploration well has been drilled, a critical piece of information is the oil type. Earlier wireline or while-drilling well-logging technologies provided rock properties and saturation information, but relied on expensive sampling and testing to determine oil properties. This weakness was overcome through the introduction of nuclear magnetic resonance (NMR) logs that can provide formation properties—lithology-independent porosity, porosity distribution, permeability, etcetera—and information about the reservoir fluid viscosity. NMR data were recently acquired in complex, high-clay content, low-salinity oil reservoirs. Traditional petrophysical interpretations throughout these reservoirs were confronted with a complex lithology—comprising feldspathic litharenites and volcanic lithic components—high clay content and low formation water salinity, of 3-4 Kppm NaCl eq. This extended abstract shows how acquisition and interpretation of NMR data not only provided porosity and porosity distribution, but also identified oil viscosity across the logged intervals. Advanced NMR log interpretation techniques (2D-NMR maps of diffusion (D) versus T2, int) were used to identify oil NMR signal. This technique produced a continuous profile of diffusion and intrinsic T2 distribution maps. Once the oil NMR signal was identified, an estimation of the oil viscosity was also possible because D and T2, int are related with viscosity. Several available correlations have been used and results were comparable with production data.

Dark-field neutron tomography was applied to obtain three-dimensional volumetric data representing the distribution of micrometer and submicrometer sized structures in bulk samples. This is a size range that complements the range of direct spatial resolution. A phase grating setup implemented in a conventional imaging instrument enables corresponding tomographic investigations on reasonable time scales. Different samples were investigated and demonstrate the applicability of the method for the investigation of structural materials. Local variations in the small-angle scattering in BiSn, AlSi, and aluminum samples were mapped and the results are discussed with respect to the contrast formation of the method.

In 2008, Central Petroleum was involved in an extended exploration campaign in the Pedirka Basin. The main targets were conventional oil and coal seam gas (CSG). A comprehensive logging program including nuclear magnetic resonance (NMR) measurements was acquired, with the scope of evaluating both targets in two wells. NMR tools measure the magnetisation of hydrogen protons present in the flushed-zone of the formation pore space. By calibrating this measurement in a water tank, NMR tools provide formation porosity independent of lithology, while classical methods for deriving porosity (density, neutron, etc.) are lithology dependent. While in conventional plays (clastics, carbonates) porosity is needed for evaluating the reservoir storage capacity, in coal beds porosity is needed for evaluating the surface areas of the pores. As methane in coal is bound to the coal surface, total pore surface affects the coal bed methane producing capacity. NMR measurements also provide information about porosity/grain size distribution, permeability and hydrocarbon saturation in conventional formations. This information can be very useful for evaluating coal seam gas, provided the conventional models can be converted and applied in coal beds. Evaluation of coal seam gas prospects using nuclear magnetic resonance is an industry first. This presentation highlights the benefits and difficulties of nuclear magnetic resonance evaluation of CSG prospects in these two wells.

In the framework of a research aiming to assess the suitability of neutron/x-ray non-destructive techniques for the characterization of archaeological objects, two bronze items were studied by neutron diffraction. The origins of two small statues are, respectively, Egyptian (XXI–XXX Dynasties, c1070–343 B.C.) and Etruscan (IV–III centuries B.C.), belonging to a private collection. By hard x-ray diffraction we previously verified that both statuettes have a coarse microstructure (big grains). From historical considerations we believe that both items were produced by solid lost wax processes of casting. This processing technique does not completely justify the presence of microstrains; as a consequence, due to unexpected neutron diffraction peak broadening, a non-uniform Sn wt% is suspected. In the present work we discuss this deduction by means of Rietveld analysis of the neutron diffraction profiles.

Residual stresses were experimentally determined in specimens of carbon-fibre composite (CFC) brazed to CuCrZr alloy, using neutron diffraction at the E3 instrument of HMI-BENSC (Berlin). The brazing was obtained by means of a Cu interlayer, one side of which was brazed to the CuCrZr alloy, after the other side was joined to CFC by a proprietary technique. Two different samples were investigated, the first one in the 'as-brazed' condition and the second one after thermal fatigue cycling [heating of samples up to 450 °C followed by a fast cooling (>1 °C s−1) to room temperature in air with water quench; the cycles were repeated 50 times for each sample]. Residual stresses were determined in the three principal directions, in the CFC and in the CuCrZr alloy, as a function of the distance from the interface with the Cu interlayer. The experimental results for the as-brazed specimen are in agreement with the results of FEM calculations available in the literature, while a relaxation of residual stresses in the thermally fatigued specimen is found to be probably ascribed to the formation of microcracks at the CFC/Cu interface.

In order to be able to reproduce historic organ reed pipes, a bulk non-destructive chemical composition analysis was performed on the tongues and shallots, focusing mainly on the ratio between copper and zinc and on the presence of lead. Prompt gamma activation analysis results allowed us to observe for the first time that the ratio between the two main components of the brass alloy changed from Cu:Zn = 3:1 for the old tongues and shallots to Cu:Zn = 2:1 around the middle of the 18th century, which is typical also for the modern alloys offered to the organ builders nowadays. We also discovered that the Pb content in the old historic brass alloy diminished until the middle of 18th century when the brass alloy became mainly Pb free.The non-uniform lead distribution inside one of the shallots obtained from a prompt gamma activation analysis (PGAA) experiment was studied by neutron tomography. It gave us a three-dimensonal (3D) distribution of the lead inclusions inside the shallots. The lead particles are concentrated towards the base of the shallot.