Comparison of direct and indirect alcohol markers with PEth in blood and Urine in alcohol dependent inpatients during detoxication

The importance of direct and indirect alcohol markers to evaluate alcohol consumption in clinical and forensic settings is increasingly recognized. While some markers are used to prove abstinence from ethanol, other markers are suitable for detection of alcohol misuse. Phosphatidyl ethanol (PEth) is ranked among the latter. There is only little information about the correlation between PEth and other currently used markers (ethyl glucuronide, ethyl sulfate, carbohydrate deficient transferrin, gamma-glutamyl transpeptidase, and methanol) and about their decline during detoxification. To get more information, 18 alcohol-dependent patients in withdrawal therapy were monitored for These parameters in blood and urine for up to 19 days. There was no correlation between the different markers. PEth showed a rapid decrease at the beginning of the intervention, a slow decline after the first few days, and could still be detected after 19 days of abstinence from ethanol.

Mechanical constraints imposed by 3D cellular geometry and arrangement modulate growth patterns in the Arabidopsis embryo

Morphogenesis occurs in 3D space over time and is guided by coordinated gene expression programs. Here we use postembryonic development in Arabidopsis plants to investigate the genetic control of growth. We demonstrate that gene expression driving the production of the growth-stimulating hormone gibberellic acid and downstream growth factors is first induced within the radicle tip of the embryo. The center of cell expansion is, however, spatially displaced from the center of gene expression. Because the rapidly growing cells have very different geometry from that of those at the tip, we hypothesized that mechanical factors may contribute to this growth displacement. To this end we developed 3D finite-element method models of growing custom-designed digital embryos at cellular resolution. We used this framework to conceptualize how cell size, shape, and topology influence tissue growth and to explore the interplay of geometrical and genetic inputs into growth distribution. Our simulations showed that mechanical constraints are sufficient to explain the disconnect between the experimentally observed spatiotemporal patterns of gene expression and early postembryonic growth. The center of cell expansion is the position where genetic and mechanical facilitators of growth converge. We have thus uncovered a mechanism whereby 3D cellular geometry helps direct where genetically specified growth takes place.

Comparison of 3D kinetic and hydrodynamic models to ROSINA-COPS measurements of the neutral coma of 67P/Churyumov-Gerasimenko

67P/Churyumov-Gerasimenko (67P) is a Jupiter-family comet and the object of investigation of the European Space Agency mission Rosetta. This report presents the first full 3D simulation results of 67P’s neutral gas coma. In this study we include results from a direct simulation Monte Carlo method, a hydrodynamic code, and a purely geometric calculation which computes the total illuminated surface area on the nucleus. All models include the triangulated 3D shape model of 67P as well as realistic illumination and shadowing conditions. The basic concept is the assumption that these illumination conditions on the nucleus are the main driver for the gas activity of the comet. As a consequence, the total production rate of 67P varies as a function of solar insolation. The best agreement between the model and the data is achieved when gas fluxes on the night side are in the range of 7% to 10% of the maximum flux, accounting for contributions from the most volatile components. To validate the output of our numerical simulations we compare the results of all three models to in situ gas number density measurements from the ROSINA COPS instrument. We are able to reproduce the overall features of these local neutral number density measurements of ROSINA COPS for the time period between early August 2014 and January 1 2015 with all three models. Some details in the measurements are not reproduced and warrant further investigation and refinement of the models. However, the overall assumption that illumination conditions on the nucleus are at least an important driver of the gas activity is validated by the models. According to our simulation results we find the total production rate of 67P to be constant between August and November 2014 with a value of about 1 × 10²⁶ molecules s⁻¹.

Accuracy of linear measurements using three imaging modalities: two lateral cephalograms and one 3D model from CBCT data

BACKGROUND The aim of this study was to evaluate the accuracy of linear measurements on three imaging modalities: lateral cephalograms from a cephalometric machine with a 3 m source-to-mid-sagittal-plane distance (SMD), from a machine with 1.5 m SMD and 3D models from cone-beam computed tomography (CBCT) data. METHODS Twenty-one dry human skulls were used. Lateral cephalograms were taken, using two cephalometric devices: one with a 3 m SMD and one with a 1.5 m SMD. CBCT scans were taken by 3D Accuitomo® 170, and 3D surface models were created in Maxilim® software. Thirteen linear measurements were completed twice by two observers with a 4 week interval. Direct physical measurements by a digital calliper were defined as the gold standard. Statistical analysis was performed. RESULTS Nasion-Point A was significantly different from the gold standard in all methods. More statistically significant differences were found on the measurements of the 3 m SMD cephalograms in comparison to the other methods. Intra- and inter-observer agreement based on 3D measurements was slightly better than others. LIMITATIONS Dry human skulls without soft tissues were used. Therefore, the results have to be interpreted with caution, as they do not fully represent clinical conditions. CONCLUSIONS 3D measurements resulted in a better observer agreement. The accuracy of the measurements based on CBCT and 1.5 m SMD cephalogram was better than a 3 m SMD cephalogram. These findings demonstrated the linear measurements accuracy and reliability of 3D measurements based on CBCT data when compared to 2D techniques. Future studies should focus on the implementation of 3D cephalometry in clinical practice.

A multimodal tablet-based interface for designing and reviewing 3D engineering models

The ability to view and interact with 3D models has been happening for a long time. However, vision-based 3D modeling has only seen limited success in applications, as it faces many technical challenges. Hand-held mobile devices have changed the way we interact with virtual reality environments. Their high mobility and technical features, such as inertial sensors, cameras and fast processors, are especially attractive for advancing the state of the art in virtual reality systems. Also, their ubiquity and fast Internet connection open a path to distributed and collaborative development. However, such path has not been fully explored in many domains. VR systems for real world engineering contexts are still difficult to use, especially when geographically dispersed engineering teams need to collaboratively visualize and review 3D CAD models. Another challenge is the ability to rendering these environments at the required interactive rates and with high fidelity. In this document it is presented a virtual reality system mobile for visualization, navigation and reviewing large scale 3D CAD models, held under the CEDAR (Collaborative Engineering Design and Review) project. It’s focused on interaction using different navigation modes. The system uses the mobile device's inertial sensors and camera to allow users to navigate through large scale models. IT professionals, architects, civil engineers and oil industry experts were involved in a qualitative assessment of the CEDAR system, in the form of direct user interaction with the prototypes and audio-recorded interviews about the prototypes. The lessons learned are valuable and are presented on this document. Subsequently it was prepared a quantitative study on the different navigation modes to analyze the best mode to use it in a given situation.

Microfabrication processes for microfluidic devices on a single laser Workstation: direct writing lithography on SU-8, laser ablation on polymers and mask manufacturing

We demonstrate the capability of a laser micromachining workstation for cost-effective manufacturing of a variety of microfluidic devices, including SU-8 microchannels on silicon wafers and 3D complex structures made on polyimide Kapton® or poly carbonate (PC). The workstation combines a KrF excimer laser at 248 nm and a Nd3+:YVO4 DPSS with a frequency tripled at 355 nm with a lens magnification 10X, both lasers working at a pulsed regime with nanoseconds (ns) pulse duration. Workstation also includes a high-resolution motorized XYZ-tilt axis (~ 1 um / axis) and a Through The Lens (TTL) imaging system for a high accurate positioning over a 120 x 120 mm working area. We have surveyed different fabrication techniques: direct writing lithography,mask manufacturing for contact lithography and polymer laser ablation for complex 3D devices, achieving width channels down to 13μ m on 50μ m SU-8 thickness using direct writing lithography, and width channels of 40 μm for polyimide on SiO2 plate. Finally, we have tested the use of some devices for capillary chips measuring the flow speed for liquids with different viscosities. As a result, we have characterized the presence of liquid in the channel by interferometric microscopy.

Identification of pore spaces in 3D CT soil images using a PFCM partitional clustering

Recent advances in non-destructive imaging techniques, such as X-ray computed tomography (CT), make it possible to analyse pore space features from the direct visualisation from soil structures. A quantitative characterisation of the three-dimensional solid-pore architecture is important to understand soil mechanics, as they relate to the control of biological, chemical, and physical processes across scales. This analysis technique therefore offers an opportunity to better interpret soil strata, as new and relevant information can be obtained. In this work, we propose an approach to automatically identify the pore structure of a set of 200-2D images that represent slices of an original 3D CT image of a soil sample, which can be accomplished through non-linear enhancement of the pixel grey levels and an image segmentation based on a PFCM (Possibilistic Fuzzy C-Means) algorithm. Once the solids and pore spaces have been identified, the set of 200-2D images is then used to reconstruct an approximation of the soil sample by projecting only the pore spaces. This reconstruction shows the structure of the soil and its pores, which become more bounded, less bounded, or unbounded with changes in depth. If the soil sample image quality is sufficiently favourable in terms of contrast, noise and sharpness, the pore identification is less complicated, and the PFCM clustering algorithm can be used without additional processing; otherwise, images require pre-processing before using this algorithm. Promising results were obtained with four soil samples, the first of which was used to show the algorithm validity and the additional three were used to demonstrate the robustness of our proposal. The methodology we present here can better detect the solid soil and pore spaces on CT images, enabling the generation of better 2D?3D representations of pore structures from segmented 2D images.

User experience with immersive and interactive media = Experiencia de usuario en entornos 3D inmersivos e interactivos

Estudios recientes promueven la integración de estímulos multisensoriales en activos multimedia con el fin de mejorar la experiencia de usuario mediante la estimulación de nuevos sentidos, más allá de la tradicional experiencia audiovisual. Del mismo modo, varios trabajos proponen la introducción de componentes de interacción capaces de complementar con nuevas características, funcionalidades y/o información la experiencia multimedia. Efectos sensoriales basados en el uso de nuevas técnicas de audio, olores, viento, vibraciones y control de la iluminación, han demostrado tener un impacto favorable en la sensación de Presencia, en el disfrute de la experiencia multimedia y en la calidad, relevancia y realismo de la misma percibidos por el usuario. Asimismo, los servicios basados en dos pantallas y la manipulación directa de (elementos en) la escena de video tienen el potencial de mejorar la comprensión, la concentración y la implicación proactiva del usuario en la experiencia multimedia. El deporte se encuentra entre los géneros con mayor potencial para integrar y explotar éstas soluciones tecnológicas. Trabajos previos han demostrado asimismo la viabilidad técnica de integrar éstas tecnologías con los estándares actualmente adoptados a lo largo de toda la cadena de transmisión de televisión. De este modo, los sistemas multimedia enriquecidos con efectos sensoriales, los servicios interactivos multiplataforma y un mayor control del usuario sobre la escena de vídeo emergen como nuevas formas de llevar la multimedia immersiva e interactiva al mercado de consumo de forma no disruptiva. Sin embargo, existen numerosas interrogantes relativas a los efectos sensoriales y/o soluciones interactivas más adecuadas para complementar un contenido audiovisual determinado o a la mejor manera de de integrar y combinar dichos componentes para mejorar la experiencia de usuario de un segmento de audiencia objetivo. Además, la evidencia científica sobre el impacto de factores humanos en la experiencia de usuario con estas nuevas formas de immersión e interacción en el contexto multimedia es aún insuficiente y en ocasiones, contradictoria. Así, el papel de éstos factores en el potencial de adopción de éstas tecnologías ha sido amplia-mente ignorado. La presente tesis analiza el impacto del audio binaural, efectos sensoriales (de iluminación y olfativos), interacción con objetos 3D integrados en la escena de vídeo e interacción con contenido adicional utilizando una segunda pantalla en la experiencia de usuario con contenidos de deporte. La posible influencia de dichos componentes en las variables dependientes se explora tanto a nivel global (efecto promedio) como en función de las características de los usuarios (efectos heterogéneos). Para ello, se ha llevado a cabo un experimento con usuarios orientado a explorar la influencia de éstos componentes immersivos e interactivos en dos grandes dimensiones de la experiencia multimedia: calidad y Presencia. La calidad de la experiencia multimedia se analiza en términos de las posibles variaciones asociadas a la calidad global y a la calidad del contenido, la imagen, el audio, los efectos sensoriales, la interacción con objetos 3D y la interacción con la segunda pantalla. El posible impacto en la Presencia considera dos de las dimensiones definidas por el cuestionario ITC-SOPI: Presencia Espacial (Spatial Presence) e Implicación (Engagement). Por último, los individuos son caracterizados teniendo en cuenta los siguientes atributos afectivos, cognitivos y conductuales: preferencias y hábitos en relación con el contenido, grado de conocimiento de las tecnologías integradas en el sistema, tendencia a involucrarse emocionalmente, tendencia a concentrarse en una actividad bloqueando estímulos externos y los cinco grandes rasgos de la personalidad: extroversión, amabilidad, responsabilidad, inestabilidad emocional y apertura a nuevas experiencias. A nivel global, nuestro estudio revela que los participantes prefieren el audio binaural frente al sistema estéreo y que los efectos sensoriales generan un aumento significativo del nivel de Presencia Espacial percibido por los usuarios. Además, las manipulaciones experimentales realizadas permitieron identificar una gran variedad de efectos heterogéneos. Un resultado interesante es que dichos efectos no se encuentran distribuidos de forma equitativa entre las medidas de calidad y Presencia. Nuestros datos revelan un impacto generalizado del audio binaural en la mayoría de las medidas de calidad y Presencia analizadas. En cambio, la influencia de los efectos sensoriales y de la interacción con la segunda pantalla se concentran en las medidas de Presencia y calidad, respectivamente. La magnitud de los efectos heterogéneos identificados está modulada por las siguientes características personales: preferencias en relación con el contenido, frecuencia con la que el usuario suele ver contenido similar, conocimiento de las tecnologías integradas en el demostrador, sexo, tendencia a involucrarse emocionalmente, tendencia a a concentrarse en una actividad bloqueando estímulos externos y niveles de amabilidad, responsabilidad y apertura a nuevas experiencias. Las características personales consideradas en nuestro experimento explicaron la mayor parte de la variación en las variables dependientes, confirmando así el importante (y frecuentemente ignorado) papel de las diferencias individuales en la experiencia multimedia. Entre las características de los usuarios con un impacto más generalizado se encuentran las preferencias en relación con el contenido, el grado de conocimiento de las tecnologías integradas en el sistema y la tendencia a involucrarse emocionalmente. En particular, los primeros dos factores parecen generar un conflicto de atención hacia el contenido versus las características/elementos técnicos del sistema, respectivamente. Asimismo, la experiencia multimedia de los fans del fútbol parece estar modulada por procesos emociona-les, mientras que para los no-fans predominan los procesos cognitivos, en particular aquellos directamente relacionados con la percepción de calidad. Abstract Recent studies encourage the integration of multi-sensorial stimuli into multimedia assets to enhance the user experience by stimulating other senses beyond sight and hearing. Similarly, the introduction of multi-modal interaction components complementing with new features, functionalities and/or information the multimedia experience is promoted. Sensory effects as odor, wind, vibration and light effects, as well as an enhanced audio quality, have been found to favour media enjoyment and to have a positive influence on the sense of Presence and on the perceived quality, relevance and reality of a multimedia experience. Two-screen services and a direct manipulation of (elements in) the video scene have the potential to enhance user comprehension, engagement and proactive involvement of/in the media experience. Sports is among the genres that could benefit the most from these solutions. Previous works have demonstrated the technical feasibility of implementing and deploying end-to-end solutions integrating these technologies into legacy systems. Thus, sensorially-enhanced media, two-screen services and an increased user control over the displayed scene emerge as means to deliver a new form of immersive and interactive media experiences to the mass market in a non-disruptive manner. However, many questions remain concerning issues as the specific interactive solutions or sensory effects that can better complement a given audiovisual content or the best way in which to integrate and combine them to enhance the user experience of a target audience segment. Furthermore, scientific evidence on the impact of human factors on the user experience with these new forms of immersive and interactive media is still insufficient and sometimes, contradictory. Thus, the role of these factors on the potential adoption of these technologies has been widely ignored. This thesis analyzes the impact of binaural audio, sensory (light and olfactory) effects, interaction with 3D objects integrated into the video scene and interaction with additional content using a second screen on the sports media experience. The potential influence of these components on the dependent variables is explored both at the overall level (average effect) and as a function of users’ characteristics (heterogeneous effects). To these aims, we conducted an experimental study exploring the influence of these immersive and interactive elements on the quality and Presence dimensions of the media experience. Along the quality dimension, we look for possible variations on the quality scores as-signed to the overall media experience and to the media components content, image, audio, sensory effects, interaction with 3D objects and interaction using the tablet device. The potential impact on Presence is analyzed by looking at two of the four dimensions defined by the ITC-SOPI questionnaire, namely Spatial Presence and Engagement. The users’ characteristics considered encompass the following personal affective, cognitive and behavioral attributes: preferences and habits in relation to the content, knowledge of the involved technologies, tendency to get emotionally involved and tendency to get absorbed in an activity and block out external distractors and the big five personality traits extraversion, agreeableness, conscientiousness, neuroticism and openness to experience. At the overall level, we found that participants preferred binaural audio than standard stereo audio and that sensory effects increase significantly the level of Spatial Presence. Several heterogeneous effects were also revealed as a result of our experimental manipulations. Interestingly, these effects were not equally distributed across the quality and Presence measures analyzed. Whereas binaural audio was foud to have an influence on the majority of the quality and Presence measures considered, the effects of sensory effects and of interaction with additional content through the tablet device concentrate mainly on the dimensions of Presence and on quality measures, respectively. The magnitude of these effects was modulated by individual’s characteristics, such as: preferences in relation to the content, frequency of viewing similar content, knowledge of involved technologies, gender, tendency to get emotionally involved, tendency to absorption and levels of agreeableness, conscientiousness and openness to experience. The personal characteristics collected in our experiment explained most of the variation in the dependent variables, confirming the frequently neglected role of individual differences on the media experience. Preferences in relation to the content, knowledge of involved technologies and tendency to get emotionally involved were among the user variables with the most generalized influence. In particular, the former two features seem to present a conflict in the allocation of attentional resources towards the media content versus the technical features of the system, respectively. Additionally, football fans’ experience seems to be modulated by emotional processes whereas for not fans, cognitive processes (and in particular those related to quality judgment) prevail.

A multimodal tablet-based interface for designing and reviewing 3D engineering models

The ability to view and interact with 3D models has been happening for a long time. However, vision-based 3D modeling has only seen limited success in applications, as it faces many technical challenges. Hand-held mobile devices have changed the way we interact with virtual reality environments. Their high mobility and technical features, such as inertial sensors, cameras and fast processors, are especially attractive for advancing the state of the art in virtual reality systems. Also, their ubiquity and fast Internet connection open a path to distributed and collaborative development. However, such path has not been fully explored in many domains. VR systems for real world engineering contexts are still difficult to use, especially when geographically dispersed engineering teams need to collaboratively visualize and review 3D CAD models. Another challenge is the ability to rendering these environments at the required interactive rates and with high fidelity. In this document it is presented a virtual reality system mobile for visualization, navigation and reviewing large scale 3D CAD models, held under the CEDAR (Collaborative Engineering Design and Review) project. It’s focused on interaction using different navigation modes. The system uses the mobile device's inertial sensors and camera to allow users to navigate through large scale models. IT professionals, architects, civil engineers and oil industry experts were involved in a qualitative assessment of the CEDAR system, in the form of direct user interaction with the prototypes and audio-recorded interviews about the prototypes. The lessons learned are valuable and are presented on this document. Subsequently it was prepared a quantitative study on the different navigation modes to analyze the best mode to use it in a given situation.

The impact of computer display height and desk design on 3D posture during information technology work by young adults

Computer display height and desk design to allow forearm support are two critical design features of workstations for information technology tasks. However there is currently no 3D description of head and neck posture with different computer display heights and no direct comparison to paper based information technology tasks. There is also inconsistent evidence on the effect of forearm support on posture and no evidence on whether these features interact. This study compared the 3D head, neck and upper limb postures of 18 male and 18 female young adults whilst working with different display and desk design conditions. There was no substantial interaction between display height and desk design. Lower display heights increased head and neck flexion with more spinal asymmetry when working with paper. The curved desk, designed to provide forearm support, increased scapula elevation/protraction and shoulder flexion/abduction.

Direct mesh: A multiresolution approach to terrain visualization

Terrain can be approximated by a triangular mesh consisting millions of 3D points. Multiresolution triangular mesh (MTM) structures are designed to support applications that use terrain data at variable levels of detail (LOD). Typically, an MTM adopts a tree structure where a parent node represents a lower-resolution approximation of its descendants. Given a region of interest (ROI) and a LOD, the process of retrieving the required terrain data from the database is to traverse the MTM tree from the root to reach all the nodes satisfying the ROI and LOD conditions. This process, while being commonly used for multiresolution terrain visualization, is inefficient as either a large number of sequential I/O operations or fetching a large amount of extraneous data is incurred. Various spatial indexes have been proposed in the past to address this problem, however level-by-level tree traversal remains a common practice in order to obtain topological information among the retrieved terrain data. A new MTM data structure called direct mesh is proposed. We demonstrate that with direct mesh the amount of data retrieval can be substantially reduced. Comparing with existing MTM indexing methods, a significant performance improvement has been observed for real-life terrain data.

Direct femtosecond laser inscription in transparent dielectrics

Since 1996 direct femtosecond inscription in transparent dielectrics has become the subject of intensive research. This enabling technology significantly expands the technological boundaries for direct fabrication of 3D structures in a wide variety of materials. It allows modification of non-photosensitive materials, which opens the door to numerous practical applications. In this work we explored the direct femtosecond inscription of waveguides and demonstrated at least one order of magnitude enhancement in the most critical parameter - the induced contrast of the refractive index in a standard borosilicate optical glass. A record high induced refractive contrast of 2.5×10-2 is demonstrated. The waveguides fabricated possess one of the lowest losses, approaching level of Fresnel reflection losses at the glassair interface. High refractive index contrast allows the fabrication of curvilinear waveguides with low bend losses. We also demonstrated the optimisation of the inscription regimes in BK7 glass over a broad range of experimental parameters and observed a counter-intuitive increase of the induced refractive index contrast with increasing translation speed of a sample. Examples of inscription in a number of transparent dielectrics hosts using high repetition rate fs laser system (both glasses and crystals) are also presented. Sub-wavelength scale periodic inscription inside any material often demands supercritical propagation regimes, when pulse peak power is more than the critical power for selffocusing, sometimes several times higher than the critical power. For a sub-critical regime, when the pulse peak power is less than the critical power for self-focusing, we derive analytic expressions for Gaussian beam focusing in the presence of Kerr non-linearity as well as for a number of other beam shapes commonly used in experiments, including astigmatic and ring-shaped ones. In the part devoted to the fabrication of periodic structures, we report on recent development of our point-by-point method, demonstrating the shortest periodic perturbation created in the bulk of a pure fused silica sample, by using third harmonics (? =267 nm) of fundamental laser frequency (? =800 nm) and 1 kHz femtosecond laser system. To overcome the fundamental limitations of the point-by-point method we suggested and experimentally demonstrated the micro-holographic inscription method, which is based on using the combination of a diffractive optical element and standard micro-objectives. Sub-500 nm periodic structures with a much higher aspect ratio were demonstrated. From the applications point of view, we demonstrate examples of photonics devices by direct femtosecond fabrication method, including various vectorial bend-sensors fabricated in standard optical fibres, as well as a highly birefringent long-period gratings by direct modulation method. To address the intrinsic limitations of femtosecond inscription at very shallow depths we suggested the hybrid mask-less lithography method. The method is based on precision ablation of a thin metal layer deposited on the surface of the sample to create a mask. After that an ion-exchange process in the melt of Ag-containing salts allows quick and low-cost fabrication of shallow waveguides and other components of integrated optics. This approach covers the gap in direct fs inscription of shallow waveguide. Perspectives and future developments of direct femtosecond micro-fabrication are also discussed.

3D reconstruction of complex dielectric function of the glass during the femtosecond micro-fabrication

We measure complex amplitude of scattered wave in the far field, and justify theoretically and numerically solution of the inverse scattering problem. This allows single-shot reconstructing of dielectric function distribution during direct femtosecond laser micro-fabrication.

3D Reconstruction of the complex dielectric function of glass during femtosecond laser micro-fabrication

We report on a new technique to reconstruct the 3D dielectric function change in transparent dielectric materials and the application of the technique for on-line monitoring of refractive index modification in BK7 glass during direct femtosecond laser microfabrication. The complex optical field scattered from the modified region is measured using two-beam, single-shot interferogram and the distribution of the modified refractive index is reconstructed by numerically solving the inverse scattering problem in Born approximation. The optical configuration suggested is further development of digital holographic microscopy (DHM). It takes advantage of high spatial resolution and almost the same optical paths for both interfering beams, and allows ultrafast time resolution.

3D reconstruction of complex dielectric function of the glass during the femtosecond micro-fabrication

We measure complex amplitude of scattered wave in the far field, and justify theoretically and numerically solution of the inverse scattering problem. This allows single-shot reconstructing of dielectric function distribution during direct femtosecond laser micro-fabrication.