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Mapping the large neural networks of animal and human brains is a fundamental but so far elusive task, because of the massive amount of data and the consequent prohibitively long image taking and processing times. We developed an effective strategy called “AXON” (Accelerated X-ray Observation of Neurons) to solve this problem. AXON can achieve comprehensive whole-brain mapping within a reasonable time by combining fast image taking and processing, plus two other critical performances: three-dimensional (3D) imaging with high and isotropic spatial resolution, and multi-scale resolution. We successfully tested this strategy with coordinated experiments at four synchrotron facilities in Japan, Taiwan, Singapore and Korea on two animal models, Drosophila and mouse. Its performances notably allowed full 3D mapping of the Drosophila brain in a few days. With reasonable improvements, AXON can deliver full mapping of large animal and human brains on a realistic time scale of a few years.

IR microscopy was first conceptualized in 1949 and the first commercial system was launched 1983. With the appearance of FPA detectors in the 90's, FTIR microscopy became a technique of choice for histology. Two decades later, the release of QCLs working in the mid-IR range refuels this promise by accelerating tremendously the acquisition of IR images for large tissue areas with high-quality spectra for chemical mapping of parameters of interest. The new QCL-IR imaging system allows a 150× faster spectral data acquisition at equivalent S/N level. The quality of spectral data is comparable while applying spectral curve-fitting treatments, thus showing that laser sources offer reliable signal over a large spectral range. If QCL-IR imaging system seem to offer the opportunity to develop routines for anatomo-pathology, several technological challenges stand in front of us to reach this goal to define the specs of an IR microscope dedicated to hospital.

Extremely brilliant infrared (IR) beams provided by synchrotron radiation sources are now routinely used in many facilities with available commercial spectrometers coupled to IR microscopes. Using these intense non-thermal sources, a brilliance two or three order of magnitude higher than a conventional source is achievable through small pinholes (

FTIR microscopy with a focal plane array (FPA) of detectors enables routine chemical imaging on individual cells in only a few minutes. The brilliance of synchrotron radiation (SR) IR sources may enhance the signal obtained from such small biosamples containing small amounts of organic matter. We investigated individual cells obtained from a cell culture specifically developed for transmission FTIR imaging using either a Globar or an SR source coupled to the same instrumentation. SR-IR source focussing was optimized to control the energy distribution on the FPA of detectors. Here we show that accessing the IR absorption distribution from all the organic contents of cells at 1 x 1 microm pixel resolution was possible only with high circulating current (or = 1.2 A) illuminating a limited number of the FPA's detectors to increase the signal-to-noise ratio of IR images. Finally, a high-current SR ring is mandatory for collecting FTIR images of biosamples with a high contrast in minutes.

In search of specific label-free biomarkers for differentiation of two oral lesions, namely oral leukoplakia (OLK) and oral squamous-cell carcinoma (OSCC), Fourier-transform infrared (FTIR) spectroscopy was performed on paraffin-embedded tissue sections from 47 human subjects (eight normal (NOM), 16 OLK, and 23 OSCC). Difference between mean spectra (DBMS), Mann-Whitney's U test, and forward feature selection (FFS) techniques were used for optimising spectral-marker selection. Classification of diseases was performed with linear and quadratic support vector machine (SVM) at 10-fold cross-validation, using different combinations of spectral features. It was observed that six features obtained through FFS enabled differentiation of NOM and OSCC tissue (1782, 1713, 1665, 1545, 1409, and 1161 cm(-1)) and were most significant, able to classify OLK and OSCC with 81.3 % sensitivity, 95.7 % specificity, and 89.7 % overall accuracy. The 43 spectral markers extracted through Mann-Whitney's U Test were the least significant when quadratic SVM was used. Considering the high sensitivity and specificity of the FFS technique, extracting only six spectral biomarkers was thus most useful for diagnosis of OLK and OSCC, and to overcome inter and intra-observer variability experienced in diagnostic best-practice histopathological procedure. By considering the biochemical assignment of these six spectral signatures, this work also revealed altered glycogen and keratin content in histological sections which could able to discriminate OLK and OSCC. The method was validated through spectral selection by the DBMS technique. Thus this method has potential for diagnostic cost minimisation for oral lesions by label-free biomarker identification.

We studied the effects of a twelve months endurance-training program on exercise-induced change in blood contents in thirteen rowers. A standardized testing-session (18 km rowing at 80 % of VO2max) was performed 19 times during the training program. Capillary blood samples were taken at rest and immediately post-exercise to analyse a wide range of serum concentrations. During exercise, glucose and lactate concentrations stabilized after only five training weeks and did not evolve from that point. Transport and hepatic protein concentrations increased with exercise up to the 15th week (p = 0.03), and remained stable from that point (p = 0.02). Evolution of exercise-induced change in alpha 1 -acid glycoprotein concentration revealed protein metabolism adaptations to training. Change in alpha 1 -acid glycoprotein concentrations were exactly opposite to that of urea and alpha 1 -antitrypsin (p = 0.01 and 0.002, respectively). Immunoglobulin concentrations exhibited important increases up to the 6th training week (p < 0.05), and a global stabilization was observed from that point. However, analysis of IgG subclasses highlighted significant changes that could not be found with the study of total IgG concentrations. Evolution of the exercise-induced change in Apo-A 1 /Apo-B concentrations ratio was also more informative about lipid metabolism than the Apo-A 1 and Apo-B concentrations taken individually. Indeed, evolution of metabolic changes during exercise should be carefully monitored during training to avoid interpretative errors on the training status of athlete.

Background Nanoparticles can be used for targeted drug delivery, in particular for brain cancer therapy. However, this requires a detailed analysis of nanoparticles from the associated microvasculature to the tumor, not easy because of the required high spatial resolution. The objective of this study is to demonstrate an experimental solution of this problem, based in vivo and post-mortem whole organ imaging plus nanoscale 3-dimensional (3D) X-ray microscopy. Results The use of gold nanoparticles (AuNPs) as contrast agents paved the way to a detailed high-resolution three dimensional (3D) X-ray and fluorescence imaging analysis of the relation between xenografted glioma cells and the tumor-induced angiogenic microvasculature. The images of the angiogenic microvessels revealed nanoparticle leakage. Complementary tests showed that after endocytotic internalization fluorescent AuNPs allow the visible-light detection of cells. Conclusions AuNP-loading of cells could be extended from the case presented here to other imaging techniques. In our study, they enabled us to (1) identify primary glioma cells at inoculation sites in mice brains; (2) follow the subsequent development of gliomas. (3) Detect the full details of the tumor-related microvasculature; (4) Finding leakage of AuNPs from the tumor-related vasculature, in contrast to no leakage from normal vasculature. Electronic supplementary material The online version of this article (doi:10.1186/s12951-015-0140-2) contains supplementary material, which is available to authorized users.

Top-level performances in endurance sports require several years of hard training loads. A major objective of this endurance training is to reach the most elevated metabolic adaptations the athlete will be able to support. As a consequence, overtraining is a recurrent problem that highly-trained athletes may experience during their career. Many studies have revealed that overtraining could be highlighted by various biochemical markers but a principal discrepancy in the diagnosis of overtraining stems from the fact that none of these markers may be considered as universal. In endurance sports, the metabolic aspects of training fatigue appear to be the most relevant parameters that may characterise overtraining when recovery is not sufficient, or when dietary habits do not allow an optimal replenishment of substrate stores. From the skeletal muscle functions to the overall energetic substrate availability during exercise, six metabolic schemes have been studied in relation to overtraining, each one related to a central parameter, i.e. carbohydrates, branched-chain amino acids, glutamine, polyunsaturated fatty acids, leptin, and proteins. We summarise the current knowledge on these metabolic hypotheses regarding the occurrence of overtraining in endurance sports.

A longitudinal biological study of 20 elite rowers was performed using capillary blood (serum) FT-IR spectra to evaluate their training load adaptations and fatigue.Difference spectra (rest serum spectra subtracted to exercise serum spectra) were used to evaluate subjects' metabolic response to exercise. Spectra classifications were used for serum contents differentiation on the basis of biomolecular absorption.For two subjects, several metabolic differentiations were observed. These started with sugars metabolism on the fifth training week, followed successively by lipid metabolism and protein metabolism, when overtraining was clinically diagnosed. Several weeks further into the training program, the same onset of metabolic differentiations was observed for eight other subjects. When differentiations reached lipid metabolism, they were asked to reduce their training loads. Unlike the overtrained subjects, a rapid recovery was observed (3 vs 22 wk) and metabolism alterations disappeared.The fatigability limit in sportsmen seemed to be situated at a certain level of metabolic stress, beyond which a rapid overtraining process recover was no longer possible.

Resume Objectifs Le suivi biologique hebdomadaire de 15 rameurs a ete realise sur une annee d'entrainement. Methodes La spectrometrie IR-TF a ete utilisee pour l'analyse des serums de repos et de fin d'entrainement. Des classifications des spectres du serum ont permis de differencier deux athletes. Resultats et conclusions En 5 e semaine, une premiere differenciation apparaissait au niveau des saccharides, puis au niveau lipidique (8–10 e ) et finalement au niveau des proteines (15 e ). C'est alors que le surentrainement fut cliniquement revele. En revanche, trois autres athletes eviterent le surentrainement en reduisant leur entrainement des qu'apparurent les differenciations sur le metabolisme lipidique. Ce type de suivi biologique apparait comme un nouvel outil de prevention du surentrainement.

Doping prevention is mainly directed to providing information on the dangers of doping to young athletes and to every profession concerned with athletic performance. Unfortunately, repression is also necessary in the fight against doping. Measurement of performance-enhancing drugs is complex, partly because of the large number of prohibited substances. A number of sophisticated analytical techniques are increasingly being used to provide the maximum detection time window. However, the effectiveness of methods to separate exogenous from endogenous biological molecules and the cost of antidoping analyses makes controls invalid or impossible. Moreover, most athletes, because of the metabolic and psychological stresses caused, legitimately refuse blood testing. It is becoming crucial to introduce new methods in the form of longitudinal health monitoring, since this is probably the most effective tool to prevent the use of doping agents when athletes become overtrained and/or overstressed. This paper describes new methods using Fourier-transform infrared spectroscopy to analyse serum from 50 microl samples of capillary blood. This technique has been shown to allow determination of the concentration of a wide range of biological molecules in a single microsample with clinically useful accuracy, and to provide a 'discriminatory biomolecular profile' to differentiate individuals on the basis of their physiological status. A specific application of this methodology is to perform longitudinal health monitoring in athletes, allowing prevention of overtraining. It is proposed to apply such methods in longitudinal studies for health monitoring and prevention of doping.

In this contribution we present the design of an original Attenuated Total Reflection (ATR)-based device designed for an IR microscope coupled to a FPA detector and optimized for in-vivo cell imaging. The optical element has been designed to perform real time experiments of cell biochemical processes. The device includes a manually removable Ge-crystal that guarantees an ease manipulation during the cell culture and a large flat surface to support the cell growth and the required change of the culture wells. This layout will allow performing sequential ATR IR imaging with the crystal immersed in the culture wells, minimizing contributions due to water vapors in the optical system. Using existing brilliant synchrotron radiation sources this ATR device may collect images at the surface of the Ge crystal at a sub-cellular spatial resolution with a penetration depth of the evanescent wave inside the sample of ~ 500 nm within few seconds. A brief summary of the cellular components that should be detected with such optical device is also presented.

Fourier-transform infrared (FTIR) synchrotron radiation (SR) microspectroscopy is a powerful molecular probe of biological samples at cellular resolution (

Combining elemental, chemical, molecular, and morphological imaging information from individual cells with a lateral resolution well below 1 x 1 microm(2) is the current technological challenge for investigating the smallest dimensions of living systems. In the race for such analytical performance, several techniques have been successfully developed; some use probes to determine given cellular contents whereas others use possible interactions between cellular matter with light or elements for characterization of contents. Morphological techniques providing information about cell dimensions have, when combined with other techniques, also opened the way to quantitative studies. New analytical opportunities are now being considered in cell biology, combining top-performance imaging techniques, applied to the same biosystem, with microscopy (nm-mum range) techniques providing elemental (micro-X-ray fluorescence, particle-induced X-ray emission, secondary-ion mass spectrometry), chemical (Raman, coherent anti-stokes Raman, Fourier-transform infrared, and near-field), molecular (UV-visible confocal and multiphoton), and morphological (AFM, ellipsometry, X-ray phase contrast, digital holography) information. Dedicated cell-culture methods have been proposed for multimodal imaging in vitro and/or ex vivo. This review shows that in addition to UV-fluorescent techniques, the imaging modalities able to provide interesting information about a cell, with high spatial and time resolution, have grown sufficiently to envisage quantitative analysis of chemical species inside subcellular compartments.

Fourier-transform infrared (FTIR) synchrotron radiation (SR) microspectroscopy is a powerful molecular probe of biological samples at cellular resolution (10 microm). As the brilliance of SR is 100-1000 times higher than that of a conventional Globar source, FTIR microscopes are now available in almost all advanced SR facilities around the world. However, in spite of this superior performance, the expected advances in IR SR microscopy have not yet been realised, particularly with regard to bio-analytical studies of single cells and soft tissues. In recent decades solid-state array detectors have revolutionized the fields of molecular spectroscopy and chemical imaging, and now new IR focal plane array detectors implemented at ultra-bright SR facilities will extend the performance and overcome the existing limitations, possibly allowing IR SR instrumentation to achieve the highest sensitivity and resolution of molecular imaging. The impact of IR imaging on large tissue area and the complexity of the analysis are discussed. In view of the high brilliance of SR sources, a comparison of published microscope images is given. Finally, it is briefly outlined how an optimized combination of IR instrumentation and SR optical systems could reach the expected advantages of a SR-based FTIR imaging system.

A variety of techniques exist that provide chemical information in the form of a spatially resolved image: electron microprobe analysis, nuclear microprobe analysis, synchrotron radiation microprobe analysis, secondary ion mass spectrometry, and confocal fluorescence microscopy. Linear (LINAC) and circular (synchrotrons) particle accelerators have been constructed worldwide to provide to the scientific community unprecedented analytical performances. Now, these facilities match at least one of the three analytical features required for the biological field: (1) a sufficient spatial resolution for single cell (< 1 μm) or tissue (

The first International Workshop on Imaging Techniques with Synchrotron Radiation (ITSR) was held in Hefei, China, from December 3–5, 2008, hosting about 20 scientists from Asia, Europe, and North America. It was funded by the National Synchrotron Radiation Laboratory (NSRL) of Hefei and the Ministry of Foreign Affairs of Italy to address the latest advances in imaging techniques using synchrotron radiation. NSRL is one of China's main investments in large-scale scientific research infrastructures whose construction was completed in December 1991 and underwent a Phase II upgrade completed in December 2004. This national facility provides high brilliance synchrotron radiation beams, covering the electromagnetic spectrum from the IR to the X-ray domain, using the emission of bending magnets and a superconducting wiggler with critical energy of 2.4 nm and 0.5 nm, respectively.

The new Brain Imaging Beamline (BIB) of the Taiwan Photon Source (TPS) has been commissioned and opened to users. The BIB and in particular its endstation are designed to take advantage of bright unmonochromatized synchrotron X-rays and target fast 3D imaging, ∼1 ms exposure time plus very high ∼0.3 µm spatial resolution. A critical step in achieving the planned performances was the solution to the X-ray induced damaging problems of the detection system. High-energy photons were identified as their principal cause and were solved by combining tailored filters/attenuators and a high-energy cut-off mirror. This enabled the tomography acquisition throughput to reach >1 mm3 min−1, a critical performance for large-animal brain mapping and a vital mission of the beamline.