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Among the several available X-ray optics for synchrotron radiation producing micrometre and submicrometre beams with high intensity, the X-ray waveguide (WG) can provide the smallest hard X-ray beam in one direction. A drawback of this optics is that, owing to the divergence at the exit, a nanometre-sized spot on the sample can only be obtained if this is within a few micrometres of the WG exit. Another limitation is that in planar WGs the beam is compressed in only one direction. Here, using a dynamically bent elliptical Si/Pt mirror, the guided X-ray beam has been refocused at ∼1 m from the waveguide exit. The large working distance between the device and the submicrometre focus leaves some space for sample environment (vacuum chamber, furnace, cryostat, magnets, high-pressure device etc.) and allows cross-coupled geometries with two WGs for efficient compression in two directions. [ABSTRACT FROM AUTHOR]

The results of a study of the structural and reflective characteristics of short-period multilayer X-ray mirrors based on Mo/B4C at wavelengths 1.54 Å, 9.89 Å and 17.59 Å are presented. The period of the samples varied in the range 8-35 Å. The average widths of the interfaces were ~3.5 and 2.2 Å at one and the other boundaries, with a tendency for weak growth with any decrease in the period. The interlayer roughness was ~1 Å. The research results indicate promising prospects for the use of multilayer Mo/B4C mirrors for synchrotron applications. [ABSTRACT FROM AUTHOR]

Here, high-throughput tomography (HiTT), a fast and versatile phase-contrast imaging platform for life-science samples on the EMBL beamline P14 at DESY in Hamburg, Germany, is presented. A high-photon-flux undulator beamline is used to perform tomographic phase-contrast acquisition in about two minutes which is linked to an automated data processing pipeline that delivers a 3D reconstructed data set less than a minute and a half after the completion of the X-ray scan. Combining this workflow with a sophisticated robotic sample changer enables the streamlined collection and reconstruction of X-ray imaging data from potentially hundreds of samples during a beam-time shift. HiTT permits optimal data collection for many different samples and makes possible the imaging of large sample cohorts thus allowing population studies to be attempted. The successful application of HiTT on various soft tissue samples in both liquid (hydrated and also dehydrated) and paraffin-embedded preparations is demonstrated. Furthermore, the feasibility of HiTT to be used as a targeting tool for volume electron microscopy, as well as using HiTT to study plant morphology, is demonstrated. It is also shown how the high-throughput nature of the work has allowed large numbers of 'identical' samples to be imaged to enable statistically relevant sample volumes to be studied. [ABSTRACT FROM AUTHOR]

X-ray tomography has been widely used in various research fields thanks to its capability of observing 3D structures with high resolution non-destructively. However, due to the nonlinearity and inconsistency of detector pixels, ring artifacts usually appear in tomographic reconstruction, which may compromise image quality and cause nonuniform bias. This study proposes a new ring artifact correction method based on the residual neural network (ResNet) for X-ray tomography. The artifact correction network uses complementary information of each wavelet coefficient and a residual mechanism of the residual block to obtain high-precision artifacts through low operation costs. In addition, a regularization term is used to accurately extract stripe artifacts in sinograms, so that the network can better preserve image details while accurately separating artifacts. When applied to simulation and experimental data, the proposed method shows a good suppression of ring artifacts. To solve the problem of insufficient training data, ResNet is trained through the transfer learning strategy, which brings advantages of robustness, versatility and low computing cost. [ABSTRACT FROM AUTHOR]

Background: The formation of concrements in human pineal gland (PG) is a physiological process and, according to many researchers, is associated with the involution of PG structures. The majority of scientific publications concern progressive calcification of PG, leaving out studies on the destruction of already formed calcified concrements. Our study fills the gap in knowledge about calcified zones destruction in PG in normal aging and neuropathological conditions, which has not been addressed until now. Purpose: Our objective is to gain insight into human PG tissue impairment in both normal aging and neurodegenerative conditions. X-ray phase-contrast tomography (XPCT) allowed us to study PG tissue degeneration at high spatial resolution and, for the first time, to examine the damaged PG concrements in detail. Our research finding could potentially enhance the understanding of the PG involvement in the process of aging as well as in Alzheimer’s disease (AD) and vascular dementia (VD). Methods: The research was carried out on human PG autopsy material in normal aging, VD, and AD conditions. Laboratory-based micro-computed tomography (micro-CT) was used to collect and evaluate samples of native, uncut, and unstained PG with different degrees of pineal calcification. The detailed high-resolution 3D images of the selected PGs were produced using synchrotron-based XPCT. Histology and immunohistochemistry of soft PG tissue confirmed XPCT results. Results: We performed via micro-CT the evaluation of the morphometric parameters of PG such as total sample volume, calcified concrements volume, and percentage of concrements in the total volume of the sample.XPCT imaging revealed high-resolution details of age-related PGalteration.In particular,we noted signs of moderate degradation of concrements in some PGs from elderly donors. In addition, our analysis revealed noticeable degenerative change in both concrements and soft tissue of PGs with neuropathology. In particular, we observed a hollow core and separated layers as well as deep ragged cracks in PG concrements of AD and VD samples. In parenchyma of some samples,we detected wide pinealocyte-free fluid-filled areas adjacent to the calcified zones. Conclusion: The present work provides the basis for future scientific research focused on the dynamic nature of PG calcium deposits and PG soft tissue in normal aging and neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

Antifouling agent 4, 5‐dichloro‐2‐n‐octyl‐4‐isothiazolin‐3‐one (DCOIT) in a one‐stage process based on the self‐catalytic reaction between methyl trimethoxysilane (MTMS) and 3‐aminopropyl trimethoxysilane (APS) in an aqueous system without any surfactants and catalysts have been developed. The optimal preparation process parameters of organosilica nanocapsules encapsulating DCOIT (DCOIT@SiNC) were determined using response surface methodology (RSM) based on the single‐factor experimental results. The results of RSM optimization showed that 49.51% encapsulation efficiency (EE [%]) would be achieved with a shell–core mass ratio of 5.59:1, a MTMS‐APS mole ratio of 1.52:1, and a reaction temperature of 31°C. DCOIT@SiNC prepared according to the RSM optimal process exhibited a decent uniform sphericity with an average particle diameter of 660.50 nm. The encapsulation was characterized by Fourier‐transform infrared and X‐ray diffraction. The loading efficiency and thermal stability were verified via thermogravimetric analysis. Compared to DCOIT, DCOIT@SiNC had better controlled release performance, and the release kinetics investigated by Riger‐peppas model indicated that the release of DCOIT was diffusion‐controlled. [ABSTRACT FROM AUTHOR]

Alzheimer's disease is histopathologically well defined by the presence of amyloid deposits and tau‐related neurofibrillary tangles in crucial regions of the brain. Interest is growing in revealing and determining possible pathological markers also in the cerebellum as its involvement in cognitive functions is now well supported. Despite the central position of the Purkinje cell in the cerebellum, its electrophysiological behaviour in mouse models of Alzheimer's disease is scarce in the literature. Our first aim was here to focus on the electrophysiological behaviour of the cerebellum in awake mouse model of Alzheimer's disease (APPswe/PSEN1dE9) and the related performance on the water‐maze test classically used in behavioural studies. We found prevalent signs of electrophysiological alterations in both Purkinje cells and deep cerebellar nuclei neurons which might explain the behavioural deficits reported during the water‐maze test. The alterations of neurons firing were accompanied by a dual (~16 and ~228 Hz) local field potential's oscillation in the Purkinje cell layer of Alzheimer's disease mice which was concomitant to an important increase of both the simple and the complex spikes. In addition, β‐amyloid deposits were present in the molecular layer of the cerebellum. These results highlight the importance of the output firing modification of the AD cerebellum that may indirectly impact the activity of its subcortical and cortical targets. [ABSTRACT FROM AUTHOR]

In recent decades, computed tomography (CT) combined with suitable image processing software has become a valuable tool to enable the reading of texts written on scrolls, which are fragile, damaged, or fused together, without physically unwrapping them. X‐ray based computer tomography has successfully been used on scrolls made of soft materials such as papyrus and parchment. Although in few cases inscriptions on thin metal plates that have been rolled up and worn as amulets have been deciphered by using a high energy X‐ray source, the readability of writings on of metal scrolls is limited by the high attenuation factor of this type of material. In this paper, we present for the first time the use of neutron tomography as an alternative to X‐ray tomography for studying hidden inscriptions on folded metal objects. It is shown that the method overcomes the limitations of X‐ray tomography caused by high attenuation of X‐rays in lead objects. The inscription on the medieval Bispegata amulet, unearthed during excavations in Oslo's Old Town, has been read by using neutron tomography combined with VG Studio software. The amulet was made up of a thin lead sheet with an inscribed text, folded together into a rectangle. The inscription was runic, containing words of religious and magic meaning. [ABSTRACT FROM AUTHOR]

The structure of spinal motion segments and spinal vasculature is complicated. Visualizing the three‐dimensional (3D) structure of the spine may provide guidance for spine surgery. However, conventional imaging techniques fail to simultaneously obtain 3D images of soft and hard tissues, and achieving such coimaging states of the spine and its vascular networks remains a challenge. Synchrotron radiation micro‐CT (SRμCT) provides a relatively effective and novel method of acquiring detailed 3D information. In this study, specimens of the thoracic spine were obtained from six mice. SRμCT was employed to acquire 3D images of the structure, and histologic staining was performed for comparisons with the SRμCT images. The whole spinal motion segments and the spinal vascular network were simultaneously explored at high resolution. The mean thickness of the cartilaginous end plates (CEPs) and the volume of the intervertebral discs (IVDs) were calculated. The surface of the CEPs and the facet joint cartilage (FJC) were presented as heat maps, which allowed for direct visualization of the thickness distribution. Regional division revealed heterogeneity among the ventral, central, and dorsal parts of the CEPs and between the superior and inferior parts of the facet processes. Moreover, the connections and spatial morphology of the spinal vascular network were visualized. Our study indicates that SRμCT imaging is an ideal method for high‐resolution visualization and 3D morphometric analysis of the whole spinal motion segments and spinal vascular network. [ABSTRACT FROM AUTHOR]

Preclinical experiments to analyze the trabecular space of spongy bones using small animals are required for the evaluation and treatment of patients with osteoporosis (OP). We performed ovariectomy to create OP models. A total of four mice were used. Ovariectomized group (OVX, n = 2) in which both ovaries were resected at random, and the sham operated group (SHAM, n = 2) performed surgery without resecting the ovaries. We propose a study that enables OP analysis by analyzing tibia microstructures of OVX and SHAM using synchrotron radiation (SR). SR imaging is a technology capable of irradiating an extremely small object in the order of several tens of nanometers using a nondestructive method at the microscopic level. Unlike previous imaging diagnoses (staining, micro‐CT [Computed Tomography]) it was possible to preserve the real shape and analyze bone microstructures in real‐time and analyze and evaluate spongy bones to secure data and increase the reliability of OP analysis. We were able to confirm the possibility of OP diagnosis through experimental animals for spongy bone damage related to bone mineral density. Therefore, we aimed to provide a rehabilitation and medicine therapy intervention method through basic research on the evaluation of OP diagnosis through human‐based segmentation of challenging spongy bones while supplementing the limitations of existing imaging methods. Research Highlights: We present an analysis of osteoporosis through spongy bone using phase‐contrast X‐ray source. Unlike existing methods, it is possible to analyze the internal microstructure of the tibia with this method. This is an objective mechanism for OP and a basis for rehabilitation. [ABSTRACT FROM AUTHOR]

High‐throughput synchrotron‐based tomographic microscopy at third generation light sources allows to probe cm‐sized samples at micrometer‐resolution. In this work, we present an approach to image a full mouse brain. With Indian‐ink as a contrast agent, it was possible to obtain 3D distribution of microvessels while a computational framework automatically extracted the morphological and geometrical embedding of the putative vascular systems. Results demonstrate the potentiality of the proposed methodology to visualize and quantify in 3D details of the brain tissue with an image quality and resolution previously unachievable. [ABSTRACT FROM AUTHOR]

The reverse projection protocol results in fast phase‐contrast imaging thanks to its compatibility with conventional computed‐tomography scanning. Many researchers have proposed variants. However, all these reverse projection methods in grating‐based phase‐contrast imaging are built on the hypothesis of the synchronous phase of reference shifting curves in the whole field of view. The hypothesis imposes uniformity and alignment requirements on the gratings, thus the field of view is generally limited. In this paper, a generalized reverse projection method is presented analytically for the case of non‐uniform reference in grating‐based phase tomography. The method is demonstrated by theoretical derivation, numerical simulations and synchrotron radiation experiments. The influence of imaging position to sensitivity, and the phase‐wrapping phenomenon are also discussed. The proposed method combines the advantages of the high efficiency of the reverse projection method and the universal applicability of the phase‐stepping method. The authors believe that the method would be used widely in fast and dose‐constrained imaging. [ABSTRACT FROM AUTHOR]

Purpose: In this work the performance of a compact multiresolution and multicontrast x‐ray phase system based on edge illumination is investigated. It has been designed for small animal imaging and with a limited footprint for ease of deployment in laboratories. Methods: The presented edge illumination system is based on a compact microfocus tungsten x‐ray source combined with a flat panel detector. The source has a maximum output of 10 W when the minimum spot size of about 15 μm is used. The system has an overall length of 70 cm. A new double sample mask design, obtained by arranging both skipped and nonskipped configurations on the same structure, provides dual resolution capability. To test the system, we carried out computed tomography (CT) scans of a plastic phantom with different source settings using both single‐image and multi‐image acquisition schemes at different spatial resolutions. In addition, CT scans of an ex‐vivo mouse specimen were acquired at the best identified working conditions to demonstrate the application of the presented system to small animal imaging. Results: We found this system delivers good image quality, allowing for an efficient material separation and improving detail visibility in small animals thanks to the higher signal‐to‐noise ratio (SNR) of phase contrast with respect to conventional attenuation contrast. The system offers high versatility in terms of spatial resolution thanks to the double sample mask design integrated into a single scanner. The availability of both multi‐ and single‐image acquisition schemes coupled with their dedicated retrieval algorithms, allows different working modes which can be selected based on user preference. Multi‐image acquisition provides quantitative separation of the real and imaginary part of the refractive index, however, it requires a long scanning time. On the other hand, the single image approach delivers the best material separation and image quality at all the investigated source settings with a shorter scanning time but at the cost of quantitativeness. Finally, we also observed that the single image approach combined with a high‐power x‐ray source may result in a fast acquisition protocol compatible with in‐vivo imaging. [ABSTRACT FROM AUTHOR]

Multiple sclerosis is a neurological disorder in which the myelin sheaths of axons are damaged by the immune response. We report here a three‐dimensional structural analysis of brain and spinal cord tissues of a mouse model of multiple sclerosis, known as experimental autoimmune encephalomyelitis (EAE). EAE‐induced mice were raised with or without administration of fingolimod, which is used in the treatment of multiple sclerosis. Brains and spinal cords dissected from the EAE mice were lyophilized so as to reconstitute the intrinsic contrast of tissue elements, such as axons, in X‐ray images. Three‐dimensional structures of the brain hemispheres and spinal cords of the EAE mice were visualized with synchrotron radiation microtomography. Microtomographic cross sections reconstructed from the X‐ray images revealed dilation of capillary vessels and vacuolation in the spinal cord of the EAE mice. Vacuolation was also observed in the cerebellum, suggesting that the neuroinflammatory response progressed in the brain. The vessel networks and vacuolation lesions in the spinal cords were modelled by automatically tracing the three‐dimensional image in order to analyze the tissue structures quantitatively. The results of the analysis indicated that the distribution of vacuolations was not uniform but three‐dimensionally localized. The mean vessel diameter showed a linear correlation with the clinical score, indicating that vasodilation is relevant to paralysis severity in the disease model. We suggest that vasodilation and vacuolation are related with neurological symptoms of multiple sclerosis. [ABSTRACT FROM AUTHOR]

A thorough understanding of inner ear anatomy is important for investigators. However, investigation of the mouse inner ear is difficult due to the limitations of imaging techniques. X‐ray phase contrast tomography increases contrast 100–1,000 times compared with conventional X‐ray imaging. This study aimed to investigate inner ear anatomy in a fresh post‐mortem mouse using X‐ray phase contrast tomography and to provide a comprehensive atlas of microstructures with less tissue deformation. All experiments were performed in accordance with our institution's guidelines on the care and use of laboratory animals. A fresh mouse cadaver was scanned immediately after sacrifice using an inline phase contrast tomography system. Slice images were reconstructed using a filtered back‐projection (FBP) algorithm. Standardized axial and coronal planes were adjusted with a multi‐planar reconstruction method. Some three‐dimensional (3D) objects were reconstructed by surface rendering. The characteristic features of microstructures, including otoconia masses of the saccular and utricular maculae, superior and inferior macula cribrosae, single canal, modiolus, and osseous spiral lamina, were described in detail. Spatial positions and relationships of the vestibular structures were exhibited in 3D views. This study investigated mouse inner ear anatomy and provided a standardized presentation of microstructures. In particular, otoconia masses were visualized in their natural status without contrast for the first time. The comprehensive anatomy atlas presented in this study provides an excellent reference for morphology studies of the inner ear. [ABSTRACT FROM AUTHOR]

This study was to construct a quantitative analysis for the diagnosis and evaluation of osteoporosis by using synchrotron radiation based X‐ray, which can analyze the three‐dimensional microstructure of white mouse tibia. The anatomical structure and microstructure of the white mouse tibia was obtained through synchrotron radiation, and to achieve this, three‐dimensional structural analysis was performed. Then, we visualized the quantified analysis and microstructure information with high‐resolution imagery through the image data obtained by synchrotron radiation. In addition, it was confirmed that synchrotron radiation can obtain more reliable results through accurate observation than analysis by the mechanical method. The present invention can provide the diagnosis and evaluation associated with osteoporosis. It is expected that this will provide a basis for the evaluation and prevention of evidence‐based skeletal diseases. Visualization of the mouse tibia based on synchrotron radiation X‐ray could be used to analyze the internal microstructures of the bone. In this study, we suggest that visualization through 3D reconstruction of the mouse tibia suggests a useful quantitative analysis method for the diagnosis and evaluation of degenerative skeletal diseases. [ABSTRACT FROM AUTHOR]

Purpose: X‐ray grating interferometry (XGI) provides substantially increased contrast over conventional absorption‐based imaging methods and therefore shows great potential for future biomedical applications. In this work, we propose a single‐shot phase retrieval method for synchrotron‐based high‐energy x‐ray grating interferometry. Contrary to existing retrieval methods, the presented novel approach enables direct retrieval of the object's phase map quantitatively from a single projection image, thus significantly simplifying the experimental procedure and reducing data acquisition times. Methods: The phase retrieval method is analytically derived, based on the phase‐attenuation duality of soft tissues when being imaged with high‐energy x rays. The sensitivity of the retrieved phase map, quantified by the standard deviation, is evaluated as a function of the photon number. Numerical experiments are performed to validate the proposed method and provide some quantitative insight. Results: The numerical results show that the method can provide high‐quality phase images, where the well‐known streak artifacts are significantly suppressed. Moreover, the retrieved phase maps confirm that the method is highly stable with respect to statistical noise. Conclusions: Thanks to simplified experimental procedure and reduced acquisition time and dose deposition to the sample, we believe that this new method can find its potential in biomedical imaging and in vivo studies. Future work will focus on the adaptation of the method to polychromatic x ray from tube source and to computed tomography. [ABSTRACT FROM AUTHOR]

We assessed the utility of synchrotron-radiation micro-computed tomography (micro- CT) for quantification of the radial geometry of the renal cortical vasculature. The kidneys of nine rats and six rabbits were perfusion fixed and the renal circulation filled with Microfil. In order to assess shrinkage of Microfil, rat kidneys were imaged at the Australian Synchrotron immediately upon tissue preparation and then post fixed in paraformaldehyde and reimaged 24 hours later. The Microfil shrank only 2-5% over the 24 hour period. All subsequent micro- CT imaging was completed within 24 hours of sample preparation. After micro- CT imaging, the kidneys were processed for histological analysis. In both rat and rabbit kidneys, vascular structures identified in histological sections could be identified in two-dimensional (2D) micro- CT images from the original kidney. Vascular morphology was similar in the two sets of images. Radial geometry quantified by manual analysis of 2D images from micro- CT was consistent with corresponding data generated by light microscopy. However, due to limited spatial resolution when imaging a whole organ using contrast-enhanced micro- CT, only arteries ≥100 and ≥60 μm in diameter, for the rat and rabbit respectively, could be assessed. We conclude that it is feasible and valid to use micro- CT to quantify vascular geometry of the renal cortical circulation in both the rat and rabbit. However, a combination of light microscopic and micro- CT approaches are required to evaluate the spatial relationships between intrarenal arteries and veins over an extensive range of vessel size. [ABSTRACT FROM AUTHOR]

Muscle spindles are skeletal muscle sensory organs involved in the sensation of position and movement of the body. We have explored the capability of phase contrast computed tomography to visualise muscle spindles in murine skeletal muscle. In particular, we have validated the visualisation of nerve fibres through phase contrast computed tomography using light microscopy on stained histological sections. We further present the first three-dimensional visualisation of muscle spindles in mouse soleus skeletal muscle in conjunction with the neurovascular bundle associated with it. [ABSTRACT FROM AUTHOR]

ABSTRACT The ability to treat large tissue defects with customized, patient-specific scaffolds is one of the most exciting applications in the tissue engineering field. While an increasing number of modestly sized tissue engineering solutions are making the transition to clinical use, successfully scaling up to large scaffolds with customized geometry is proving to be a considerable challenge. Managing often conflicting requirements of cell placement, structural integrity, and a hydrodynamic environment supportive of cell culture throughout the entire thickness of the scaffold has driven the continued development of many techniques used in the production, culturing, and characterization of these scaffolds. This review explores a range of technologies and methods relevant to the design and manufacture of large, anatomically accurate tissue-engineered scaffolds with a focus on the interaction of manufactured scaffolds with the dynamic tissue culture fluid environment. Biotechnol. Bioeng. 2017;114: 1129-1139. © 2016 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

The spinal cord is the primary neurological link between the brain and other parts of the body, but unlike those of the brain, advances in spinal cord imaging have been challenged by the more complicated and inhomogeneous anatomy of the spine. Fortunately with the advancement of high technology, phase-contrast synchrotron radiation microtomography has become widespread in scientific research because of its ability to generate high-quality and high-resolution images. In this study, this method has been employed for nondestructive imaging of the internal microstructure of rat spinal cord. Furthermore, digital virtual slices based on phase-contrast synchrotron radiation were compared with conventional histological sections. The three-dimensional internal microstructure of the intramedullary arteries and nerve fibers was vividly detected within the same spinal cord specimen without the application of a stain or contrast agent or sectioning. With the aid of image post-processing, an optimization of vessel and nerve fiber images was obtained. The findings indicated that phase-contrast synchrotron radiation microtomography is unique in the field of three-dimensional imaging and sets novel standards for pathophysiological investigations in various neurovascular diseases. [ABSTRACT FROM AUTHOR]

Polyelectrolyte (PE) and nanocomposite (NC) microcapsules fabricated by layer-by-layer technique have been of great interest in the past decade as novel entities for cargo encapsulation and delivery as well as for diagnostic purposes. The unique physicochemical properties of polymers and inorganic nanoparticles used in layer-by-layer synthesis of PE and NC microcapsules make them promising in various fields, such as storage, catalysis, cells imaging, controlled drug release, and targeted drug delivery. However, the requirement of the cargo encapsulation is that the cargo should have a relatively large molecular weight in order to avoid the leakage from the capsules. In this review, recent progress in the design and functionalization of PE and NC microcapsules using sol-gel method for storage of small cargos have been presented. Moreover, various remote exposures on the permeability of organic/inorganic composite microcapsule shells such as ultrasound, magnetic field gradient, laser, and microwave radiation have been observed. Finally, the description and discussion of the new trends and perspectives for improved functionality of PE microcapsules are the major topic of this progress report. [ABSTRACT FROM AUTHOR]

ABSTRACT Porcine acellular dermal matrix (PADM) has been investigated widely as a natural biomaterial. However, the success of PADM has been limited by insufficient stability and poor physicochemical properties. In our work, alginate dialdehyde (ADA) with various oxidation degrees (OD = 25%, 45%, and 65%) were explored to modify PADM, while glutaraldehyde (GA), dehydrathermal treatment (DHT), and carbodiimide (EDC) were used as the control. The efficacy of ADA on modifying PADM increased along with the rising of oxidation degree. The ADA (OD = 65% and 45%) groups showed better mechanical and thermal stability, crosslink density, and resistance to enzymatic degradation than ADA (OD = 25%) and DHT + EDC group. Meanwhile, the structure of PADM crosslinked by ADA (OD = 45% and 65%) were maintained largely. Further, ADA (OD = 45%) group revealed better cytocompatibility than DHT + EDC, ADA (OD = 65%) and GA group. Considering the balance of cytocompatibility and physicochemical behavior, ADA (OD = 45%) was more suitable as a natural derived crosslinker to modify PADM in tissue engineering. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43550. [ABSTRACT FROM AUTHOR]

Many spinal cord circulatory disorders present the substantial involvement of small vessel lesions. The central sulcus arteries supply nutrition to a large part of the spinal cord, and, if not detected early, lesions in the spinal cord will cause irreversible damage to the function of this organ. Thus, early detection of these small vessel lesions could potentially facilitate the effective diagnosis and treatment of these diseases. However, the detection of such small vessels is beyond the capability of current imaging techniques. In this study, an imaging method is proposed and the potential of phase-contrast imaging (PCI)- and attenuation-contrast imaging (ACI)-based synchrotron radiation for high-resolution tomography of intramedullary arteries in mouse spinal cord is validated. The three-dimensional vessel morphology, particularly that of the central sulcus arteries (CSA), detected with these two imaging models was quantitatively analyzed and compared. It was determined that both PCI- and ACI-based synchrotron radiation can be used to visualize the physiological arrangement of the entire intramedullary artery network in the mouse spinal cord in both two dimensions and three dimensions at a high-resolution scale. Additionally, the two-dimensional and three-dimensional vessel morphometric parameter measurements obtained with PCI are similar to the ACI data. Furthermore, PCI allows efficient and direct discrimination of the same branch level of the CSA without contrast agent injection and is expected to provide reliable biological information regarding the intramedullary artery. Compared with ACI, PCI might be a novel imaging method that offers a powerful imaging platform for evaluating pathological changes in small vessels and may also allow better clarification of their role in neurovascular disorders. [ABSTRACT FROM AUTHOR]

The lack of models describing the propagation of X-rays in waveguides and the interference mechanism between incident and reflected radiation waves hamper the understanding and the control of wave propagation phenomena occurring in many real systems. Here, experimental spectra collected at the exit of microchannel plates (MCPs) under the total X-ray reflection condition are presented. The results are discussed in the framework of a theoretical model in which the wave propagation is enhanced by the presence of a transition layer at the surface. The angular distributions of the propagating radiation at the exit of these MCPs with microchannels of ∼3 µm diameter will also be presented and discussed. These spectra show contributions associated with the reflection of the primary monochromatic beam and with the fluorescence radiation originating from the excitation of atoms composing the surface of the microchannel. The soft X-ray fluorescence spectra collected at the exit of microcapillaries were analyzed in the framework of a wave approximation while diffraction contributions observed at the exit of these hollow X-ray waveguides have been calculated using the Fraunhofer diffraction model for waves in the far-field domain. Data collected at the Si L-edge show that in glassy MCPs the fluorescence radiation can be detected only when the energy of the primary monochromatic radiation is above the absorption edge for grazing angles higher than half of the critical angle of the total reflection phenomenon. Experimental data and simulations of the propagating radiation represent a clear experimental confirmation of the channeling phenomenon of the excited fluorescence radiation inside a medium and point out that a high transmission can be obtained in waveguide optics for parameters relevant to X-ray imaging. [ABSTRACT FROM AUTHOR]

A compound optical system for coherent focusing and imaging at the nanoscale is reported, realised by high-gain fixed-curvature elliptical mirrors in combination with X-ray waveguide optics or different cleaning apertures. The key optical concepts are illustrated, as implemented at the Göttingen Instrument for Nano-Imaging with X-rays (GINIX), installed at the P10 coherence beamline of the PETRA III storage ring at DESY, Hamburg, and examples for typical applications in biological imaging are given. Characteristic beam configurations with the recently achieved values are also described, meeting the different requirements of the applications, such as spot size, coherence or bandwidth. The emphasis of this work is on the different beam shaping, filtering and characterization methods. [ABSTRACT FROM AUTHOR]

Horns of Saiga antelope ( Saiga tatarica) have always been an ingredient of 'Lingyangjiao', a traditional Chinese medicine ( TCM). Persistent hunting for Saiga antelope has already threatened the survival of critical endangered populations in wild. To control the growing pressure, CITES and Chinese government have legislated for monitoring the trade of Saiga horns. However, similar ungulate horns are difficult to identify by their morphological characteristics, which has impeded the law enforcement. Besides Saiga antelope, other seven ungulate species which have similar horns are also sold and marked as 'Lingyangjiao' in TCM markets to offset shortage of Saiga antelope horns. Such species are Gazella subgutturosa, Pantholops hodgsonii, Procapra picticaudata, Procapra gutturosa, Procapra przewalskii, Capra hircus, and Ovis aries. Our study aimed at implementing DNA barcoding technology to diagnose Saiga horns and the substitutes. We successfully extracted genomic DNA from horn samples. We recovered COI sequences of 644 bp with specific primers and 349 bp with nested PCR primers designed for degraded horn samples. The mean interspecific genetic distance of data set of the 644-bp full barcodes and the 349-bp mini-barcodes was 14.96% and 15.38%, respectively, and the mean intraspecific distance was 0.24% and 0.20%, respectively. Each species formed independent clades in neighbor-joining ( NJ) phylogenetic tree of the two data sets with >99% supporting values, except P. gutturosa and P. przewalskii. The deep genetic distances gap and clear species clades in NJ tree of either full barcodes or mini-barcodes suggest that barcoding technology is an effective tool to diagnose Saiga horns and their substitutes. Barcoding diagnosis protocol developed here will simplify diagnosis of 'Lingyangjiao' species and will facilitate conservation of endangered ungulates involved in TCM 'Lingyangjiao' markets, especially the Saiga antelope. [ABSTRACT FROM AUTHOR]

A description of the rocking curve in diffraction enhanced imaging (DEI) is presented in terms of the angular signal response function and a simple multi-information retrieval algorithm based on the cosine function fitting. A comprehensive analysis of noise properties of DEI is also given considering the noise transfer characteristic of the X-ray source. The validation has been performed with synchrotron radiation experimental data and Monte Carlo simulations based on the Geant4 toolkit combined with the refractive process of X-rays, which show good agreement with each other. Moreover, results indicate that the signal-to-noise ratios of the refraction and scattering images are about one order of magnitude better than that of the absorption image at the edges of low- Z samples. The noise penalty is drastically reduced with the increasing photon flux and visibility. Finally, this work demonstrates that the analytical method can build an interesting connection between DEI and GDPCI (grating-based differential phase contrast imaging) and is widely suitable for a variety of measurement noise in the angular signal response imaging prototype. The analysis significantly contributes to the understanding of noise characteristics of DEI images and may allow improvements to the signal-to-noise ratio in biomedical and material science imaging. [ABSTRACT FROM AUTHOR]

X-ray nanoprobes require coherent illumination to achieve optic-limited resolution, and so will benefit directly from diffraction-limited storage rings. Here, the example of high-resolution X-ray fluorescence tomography is focused on as one of the most voracious demanders of coherent photons, since the detected signal is only a small fraction of the incident flux. Alternative schemes are considered for beam delivery, sample scanning and detectors. One must consider as well the steps before and after the X-ray experiment: sample preparation and examination conditions, and analysis complexity due to minimum dose requirements and self-absorption. By understanding the requirements and opportunities for nanoscale fluorescence tomography, one gains insight into the R&D challenges in optics and instrumentation needed to fully exploit the source advances that diffraction-limited storage rings offer. [ABSTRACT FROM AUTHOR]

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ABSTRACT Mongolian gazelles are Central Asia's most abundant plains ungulate and an iconic symbol of large unfragmented grasslands. Despite a long history of commercial harvesting and subsistence hunting by herding households, adult gazelle demographic data is almost non-existent. We calculated cause-specific mortality rates for 49 adult gazelles collared with a global positioning system. Exponential models provided better fits to survival distributions from collared gazelles than did either Weibull or Gompertz models, and yielded an overall estimated annual mortality risk of 36%. The estimated daily hazard rate from human-caused mortality was 30% greater than the hazard rate due to natural mortality alone. Estimated median lifespan of adult gazelles was just 4 years, which concurred with age data taken from incisor cementum annuli obtained from harvested animals and from a natural mass mortality. For gazelles that have already reached adulthood, in the absence of hunting mortality, the estimated median lifespan of collared gazelles increased from 4 years to 8 years. Survivorship estimates from the complete telemetry dataset (including both natural and human-caused mortality sources) yielded lifespan estimates in line with greatly shortened lifespans evident during periods of heightened mortality, whether from a mass-mortality event or commercial hunting. When compared to earlier population models for the species, our results suggest current survival rates based on measures of natural and human-caused mortality will not support a stable population. © 2013 The Wildlife Society. [ABSTRACT FROM AUTHOR]

The Ag nanoparticles with different morphology are directly prepared on Si surface by a facile silver mirror reaction without capping agents and shape-controlling seeds. Ag nanoplates and Ag polyhedrons are produced on the Si surface by controlling the reaction temperature. Ag nanoplates are easily obtained at the low temperature, which are the products controlled by kinetics pathway. Ag polyhedrons are produced at the high temperature under the combined action of the surface energy and strain energy. Through the catalysis of Ag nanoplates and Ag polyhedrons, different nanoporous structures on the Si surface are obtained using the same etching process, which are useful for the antireflection layers in solar-cell devices. [ABSTRACT FROM AUTHOR]

The properties of X-ray vacuum-gap waveguides (WGs) with additional periodic structure on one of the reflecting walls are studied. Theoretical considerations, numerical simulations and experimental results confirm that the periodic structure imposes additional conditions on efficient propagation of the electromagnetic field along the WGs. The transmission is maximum for guided modes that possess sufficient phase synchronism with the periodic structure (here called `super-resonances'). The field inside the WGs is essentially given at low incidence angle by the fundamental mode strongly coupled with the corresponding phased-matched mode. Both the simulated and the experimental diffraction patterns show in the far field that propagation takes place essentially only for low incidence angles, confirming the mode filtering properties of the structured X-ray waveguides. [ABSTRACT FROM AUTHOR]

The performance of a recently developed full-field X-ray micro-imaging system based on an in-line Bragg magnifier is reported. The system is composed of quasi-channel-cut crystals in combination with a Medipix single-photon-counting detector. A theoretical and experimental study of the imaging performance of the crystals-detector combination and a comparison with a standard indirect detector typically used in high-resolution X-ray imaging schemes are reported. The spatial resolution attained by our system is about 0.75 µm, limited only by the current magnification. Compared with an indirect detector system, this system features a better efficiency, signal-to-noise ratio and spatial resolution. The optimal working resolution range of this system is between ∼0.4 µm and 1 µm, filling the gap between transmission X-ray microscopes and indirect detectors. Applications for coherent full-field imaging of weakly absorbing samples are shown and discussed. [ABSTRACT FROM AUTHOR]

The propagation of hard X-ray synchrotron beams in waveguides with guiding layer diameters in the 9-35 nm thickness range has been studied. The planar waveguide structures consist of an optimized two-component cladding. The presented fabrication method is suitable for short and leak-proof waveguide slices with lengths (along the optical axis) in the sub-500 µm range, adapted for optimized transmission at photon energies of 11.5-18 keV. A detailed comparison between finite-difference simulations of waveguide optics and the experimental results is presented, concerning transmission, divergence of the waveguide exit beam, as well as the angular acceptance. In a second step, two crossed waveguides have been used to create a quasi-point source for propagation-based X-ray imaging at the new nano-focus endstation of the P10 coherence beamline at Petra III. By inverting the measured Fraunhofer diffraction pattern by an iterative error-reduction algorithm, a two-dimensional focus of 10 nm × 10 nm is obtained. Finally, holographic imaging of a lithographic test structure based on this optical system is demonstrated. [ABSTRACT FROM AUTHOR]

A periodic multilayer waveguide for X-rays with an air gap serving as a guiding layer is considered. The propagation of hard X-ray guided modes through such a waveguide has been investigated with the help of numerical modeling. The propagation lengths of the guided modes are analyzed thoroughly with respect to their dependence on the reflectivity of the periodic multilayers forming the waveguide. It is shown that the guided modes can be generated even in a waveguide composed of low-reflectivity multilayers. The influence of a standing wave inside the reflecting multilayers on the transmission of the guided waves by the waveguide is demonstrated. Conditions which are favorable for the excitation of the guided modes are discussed. [ABSTRACT FROM AUTHOR]

Copyright of Conservation Biology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Here, soft X-ray synchrotron radiation transmitted through microchannel plates is studied experimentally. Fine structures of reflection and XANES Si L-edge spectra detected on the exit of silicon glass microcapillary structures under conditions of total X-ray reflection are presented and analyzed. The phenomenon of the interaction of channeling radiation with unoccupied electronic states and propagation of X-ray fluorescence excited in the microchannels is revealed. Investigations of the interaction of monochromatic radiation with the inner-shell capillary surface and propagation of fluorescence radiation through hollow glass capillary waveguides contribute to the development of novel X-ray focusing devices in the future. [ABSTRACT FROM AUTHOR]

Since the introduction of functional magnetic resonance imaging (fMRI), several computational approaches have been developed to examine the effect of the morphology and arrangement of blood vessels on the blood oxygenation‐level dependent (BOLD) signal in the brain. In the present work, we implemented the original Ogawa's model using a numerical simulation based on the finite element method (FEM) instead of the analytical models. In literature, there are different works using analytical methods to analyse the transverse relaxation rate (R2∗), which BOLD signal is related to, modelling the vascular system with simple and canonical geometries such as an infinite cylinder model (ICM) or a set of cylinders. We applied the numerical simulation to the extravascular BOLD signal as a function of angular vessel distribution (perpendicular vs parallel to the static magnetic field) relevant for anatomical districts characterized by geometrical symmetries, such as spinal cord. Numerical simulations confirmed analytical results for the canonical ICM. Moreover, the perturbation to the magnetic field induced by blood deoxyhaemoglobin, as quantified assuming Brownian diffusion of water molecules around the vessel, revealed that vessels contribute the most to the variation of the R2∗ when they are preferentially perpendicular to the external magnetic field, regardless of their size. Our results indicate that the numerical simulation method is sensitive to the effects of different vascular geometry. This work highlights the opportunity to extend R2∗ simulations to realistic models of vasculature based on high‐resolution anatomical images. [ABSTRACT FROM AUTHOR]

Mass mortality events in wildlife are a growing concern. Under conditions of rapid global change, opportunistic responses in bacterial commensals, triggered by environmental stressors, may be increasingly implicated in die‐offs. In 2015, over 200,000 saiga antelope died of hemorrhagic septicemia caused by the pathogen Pasteurella multocida serotype B. We use this case to explore die‐offs from commensal bacteria more broadly, looking at factors which might favor such extreme events. We review other recorded disease outbreaks caused by Pasteurellaceae organisms, firstly in saiga and secondly in other wild ungulates, and ask whether the 2015 die‐off was unprecedented in terms of mortality rates, numbers dead, spatial scale, and in the nature of the predisposing or environmental factors involved. We also compare these outbreaks with mass mortality events associated with commensal bacteria in wildlife more generally. We identify three additional major die‐offs in saiga in which Pasteurellaceae organisms may be implicated, of which one in 1988 closely resembles the 2015 hemorrhagic septicemia event. No other recorded cases in wild ungulates approach the magnitude of these cases for any of the metrics considered, possible exceptions being die‐offs in Mongolian gazelles, in which the role of these pathogens is poorly substantiated. Environmental triggers were the most commonly suggested factor leading to pathogenesis, with warm humid conditions most commonly associated with hemorrhagic septicemia. Life history may also be significant—saigas are migratory and the largest pasteurellosis outbreaks outside this species also occur in migratory species of bird or other temperate ungulates aggregating in large numbers. Cases provoked by other commensals tend to be small in magnitude. Exceptions involve interactions between multiple pathogens and climatic conditions or sets of climatic conditions acting on different stages of the host–pathogen life cycle, leading to time lags between infection and subsequent disease. Overall, the scale and rapidity of the saiga die‐offs appear unprecedented among mortality events caused by bacterial commensals in wild mammals. Experimental research into the genetics and microbiology of host–pathogen interactions upon changes in the external environment, and monitoring of animals and conditions at calving sites, may eventually reveal the underlying causes of these die‐offs. [ABSTRACT FROM AUTHOR]