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The micro-CT imaging of vasculature is a powerful tool for evaluation of angiogenesis, a prominent characteristic of hepatic fibrosis. The segment or bifurcation density, which is usually adopted to evaluate the degree of hepatic fibrosis, does not always work and may lead to incorrect assessment, especially when the three-dimensional vasculature obtained is imperfect in sample preparation or image collection. In this paper, we propose a new parameter to solve this problem. The experimental results demonstrate that the method is robust and reliable, and is practical for angiogenesis evaluation, despite of image data imperfections. This quantitative analysis method can be extended to investigate other kinds of diseases in which vasculature change is a key indicator.

A new method of terahertz (THz) imaging based on the mean absorption is proposed. Terahertz radiation is an electromagnetic radiation in the range between millimeter waves and far infrared. THz pulse imaging emerges as a novel tool in many fields because of its low energy and non-ionizing character, such as material, chemical, biological medicine and food safety. A character of THz imaging technique is it can get large amount of information. How to extract the useful parameter from the large amount of information and reconstruct sample's image is a key technology in THz imaging. Some efforts have been done for advanced visualization methods to extract the information of interest from the raw data. Both time domain and frequency domain visualization methods can be applied to extract information on the physical properties of samples from THz imaging raw data. The process of extracting useful parameter from raw data of the new method based on the mean absorption was given in this article. This method relates to the sample absorption and thickness, it delivers good signal to noise ratio in the images, and the dispersion effects are cancelled. A paper with a "THz" shape hole was taken as the sample to do the experiment. Traditional THz amplitude imaging methods in time domain and frequency domain are used to achieve the sample's image, such as relative reduction of pulse maximum imaging method, relative power loss imaging method, and relative power loss at specific frequency imaging method. The sample's information that reflected by these methods and the characteristics of these methods are discussed. The method base on the mean absorption within a certain frequency is also used to reconstruct sample's image. The experimental results show that this new method can well reflect the true information of the sample. And it can achieve a clearer image than the other traditional THz amplitude imaging methods. All the experimental results and theoretical analyses indicate that the method base on the mean absorption within a certain frequency can reflects sample absorb and thickness information, it can achieve good signal to noise ratio in the images. Because the absorption is mean absorption within in a certain frequency, so the method proposed in this article is especially suitable for samples with simple structure. And this new method can be a useful added tool for the other traditional THz amplitude imaging methods.

External fields (e.g. electromagnetic field, electric field, etc.) are often applied to modify the solidification structure of metallic alloys. The dynamic process of structure modification is invisible because of the opacity of metallic alloys. To understand the modification mechanism, it is necessary to discover the microstructure evolution during solidification. In present paper, we focus on studying the influence of pulsed electric current (PEC) on dendrite growth of Sn-Bi alloy by insitu and real time observation using the third synchrotron X-ray source at Shanghai Synchrotron Radiation Facility (SSRF) in China. The modification mechanism of PEC on solidification structure is analyzed based on a series of real time observations.

X-ray three-dimensional (3D) imaging technology is a research hotspot in the field of X-ray imaging. However, for some special imaging targets, the imaging mode of the traditional computer tomography (CT) circular trajectory is prone to lack of projection information, and thus affects the quality of CT reconstruction images, which limites the application of CT imaging. Light field imaging technology, in which a microlens array is inserted between the sensor and main lens in a traditional camera, achieves four-dimensional (4D) light field data with sensor during imaging including both the two-dimensional (2D) directional information of the radiance propagation and 2D spatial distribution information of object radiation. Through computer calculation imaging, 3D imaging such as digital refocusing, slice in the depth direction, stereo imaging, and depth estimation is realized. This article focuses on the 3D X-ray imaging based on the theory of light field imaging in visible light. Based on the model of parallel X-ray of synchrotron radiation source, the data of the X-ray light field with many projection views are acquired by rotating the image sample. Then, the light passing through any voxel in the imaging target is acquired by a geometric projection method, and based on integral imaging theory of light field imaging, the gray value of the slice in depth dimension is reconstructed and the depth information of reconstructed target is acquired. The reconstruction results show that this method can be used to reconstruct the internal slices at any depth in any viewing direction of the imaging target. In the optical imaging, the scene beyond the depth of field is blurred, making the scene more prominent and the imaging effect better. However, for the X-ray imaging, the imaging mode that is completely transmissive, and the light passing through the foreground carry the information about the background. In the refocusing process, the object at the refocusing depth is focused, and other background information is defocused. Excessive background information overwhelms the real useful information, and makes the slice, especially the edge of the image, blurred. Consequently more severe background noise is introduced due to the defocusing phenomenon in the optical refocusing process. Referring to the reconstruction method of the X-ray 3D imaging and light field imaging, the S-L filter is applied to the original data in the article. After filtering the original data, the X-ray "light field refocusing" is processed. The reconstruction results shown that the method can effectively eliminate reconstruction artifacts and improve image reconstruction quality in the reconstruction depth slice. And in this paper, the light field data are collected by rotating the sample with low time resolution. For the fast imaging, according to the digital refocusing theory of the light field imaging, the array X-ray source and detector can be used. After being calibrated, the system can realize the 3D reconstruction of the light field of the target field with high time resolution. This research has not only the theoretical significance in algorithm, but also great application value in the rapid detection of more complicated targets such as industry and medical treatment.

Kinetic surface roughening of electrodeposited PdP and NiP amorphous films were investigated by atomic force microscopy and X-rays phase-contrast radiography. Anomalous scaling of the interface width was observed for PdP system, with H = 0.75 ± 0.06, βloc = 0.49 ± 0.07 and β = 0.38 ± 0.08. In contrast, NiP system shows normal scaling behavior, with H = 0.70 ± 0.02 and β = 0.16 ± 0.03. The results suggest that surface roughening during film growth is strongly influenced by local behaviors like hydrogen evolution reaction, which shifts surface roughening from normal scaling in NiP to anomalous scaling in PdP. Keywords: Electrodeposition, Amorphous alloys, Kinetic roughening, Synchrotron, Phase-contrast radiography, HER

Terahertz radiation is an electromagnetic radiation in the range between millimeter waves and far infrared. Due to its low energy and non-ionizing characters, THz pulse imaging emerges as a novel tool in many fields, such as material, chemical, biological medicine, and food safety. Limited spatial resolution is a significant restricting factor of terahertz imaging technology. Near field imaging method was proposed to improve the spatial resolution of terahertz system. Submillimeter scale's spauial resolution can be achieved if the income source size is smaller than the wawelength of the incoming source and the source is very close to the sample. But many changes were needed to the traditional terahertz time domain spectroscopy system, and it's very complex to analyze sample's physical parameters through the terahertz signal. A method of inserting a pinhole upstream to the sample was first proposed in this article to improve the spatial resolution of traditional terahertz time domain spectroscopy system. The measured spatial resolution of terahertz time domain spectroscopy system by knife edge method can achieve spatial resolution curves. The moving stage distance between 10 % and 90 Yo of the maximum signals respectively was defined as the, spatial resolution of the system. Imaging spatial resolution of traditional terahertz time domain spectroscopy system was improved dramatically after inserted a pinhole with diameter 0. 5 mm, 2 mm upstream to the sample. Experimental results show that the spatial resolution has been improved from 1. 276 mm to 0. 774 mm, with the increment about 39 %. Though this simple method, the spatial resolution of traditional terahertz time domain spectroscopy system was increased from millimeter scale to submillimeter scale. A pinhole with diameter 1 mm on a polyethylene plate was taken as sample, to terahertz imaging study. The traditional terahertz time domain spectroscopy system and pinhole inserted terahertz time domain spectroscopy system were applied in the imaging experiment respectively. The relative THz-power loss imaging of samples were use in this article. This method generally delivers the best signal to noise ratio in loss images, dispersion effects are cancelled. Terahertz imaging results show that the sample's boundary was more distinct after inserting the pinhole in front of, sample. The results also conform that inserting pinhole in front of sample can improve the imaging spatial resolution effectively. The theoretical analyses of the method which improve the spatial resolution by inserting a pinhole in front of sample were given in this article. The analyses also indicate that the smaller the pinhole size, the longer spatial coherence length of the system, the better spatial resolution of the system. At the same time the terahertz signal will be reduced accordingly. All the experimental results and theoretical analyses indicate that the method of inserting a pinhole in front of sample can improve the spatial resolution of traditional terahertz time domain spectroscopy system effectively, and it will further expand the application of terahertz imaging technology.

This paper is aimed to microscopic identification of traditional Chinese medicines (TCMs) using an in situ imaging method. In this study, two kinds of Zingiberaceae seeds, Amomi Rotundus Fructus and Alpiniae Katsumadai Semen, were investigated by synchrotron radiation in-line X-ray phase-contrast computed tomography (IXPCT) imaging method. The results showed that the microstructures of these Zingiberaceae seeds could be clearly obtained from the virtual slices information in different observing angles. It proves that IXPCT is an effective imaging method, which can provide the imaging information for the microscopic identification of the intact TCMs in situ and non-destructively.

Third-generation synchrotron radiation X-ray phase-contrast microscopy(XPCM)can be used for obtaining image with edge enhancement, and achieve the high contrast imaging of low-Z materials with the spatial coherence peculiarity of X-rays. In the present paper, the characteristic microstructures of adhesive at the interface and their penetration in wood/bamboo composite material were investigated systematically by XPCM at Shanghai Synchrotron Radiation Facility (SSRF). And the effect of several processing techniques was analyzed for the adhesive penetration in wood/bamboo materials. The results show that the synchrotron radiation XPCM is expected to be one of the important precision detection methods for wood-based panels.

CT is widespread non-destructive detection technique for wood materials, and the density measurement is a key role during this application. In the present report, the use of CT for air-dry density measurement of wood and bamboo is described. The authors found that there were marked linear correlations between air-dry density (0.303-1.061 g x cm(-3)) of 24 kinds of woods and their respective CT value, as well as 25 kinds of lignin materials (including 24 kinds of woods and 1 kind of bamboo) and the CT value, both with correlation coefficient of 0.99, which belonged to the CT technological breakthrough for wood quantitative detection These research results show that CT is an appropriate way to measure density for wood and bamboo, and would provide technical support for CT used in the field of wood science research and wood processing.

To detect deep-level microvascular structure in rat hind limb by synchrotron radiation and microangiographic technique.Microangiography in vivo and ex vivo was performed by synchrotron radiation based absorption imaging and phase contrast imaging, with omnipaque and barium sulfate solution as contrast media, respectively, and synchrotron radiation-based micro-computed tomography (SRmCT) was also performed to reveal three-dimensional morphology of the blood vessel in rat hind limb.Using microangiographic technique in vivo and in vitro (with barium sulfate), blood vessels in the rat limb muscle could be visualized with high resolution, and the fourth branches of iliac artery in rat hind limb could be detected with the minimum visualized blood vessels about 40 µm and 9 µm in diameter, respectively. In addition, the vascular network could be defined and analyzed at the micrometer scale from the 3D renderings of limb vessel as shown by SRmCT.Synchrotron radiation-based microangiography and SRmCT thus provided a practical and effective means to observe the microvasculature of rat hindlimb, which might be useful in assessment of angiogenesis in lower limbs.

To compare the morphological difference between dermal tissue of normal skin and that of scar in rat, and to explore its structural pattern.The full-thickness skin and the scar tissue formed 3 weeks after wound healing from SD rats were harvested as samples, which were prepared appropriately afterwards. Samples were scanned and imaged with synchrotron radiation technology, micro-CT, and phase-contrast imaging technology. The images were rebuilt with three-dimensional software.The micro-CT was materialized by using X-ray generated by synchrotron radiation light source. The structure of dermal tissues was clearly shown with the assistance of phase-contrast imaging technology in the process. It was demonstrated that the dermal tissues of normal skin of rat were mainly composed of collagenous fibers, which twined together to form an olive-like structure. These olive-like structures as basic units were arranged randomly in a certain way. The collagenous fibers in dermal tissue of the scar were arranged in a parallel manner, while some fibers were crooked and arranged in a disorderly manner.Dermal tissue of normal skin in rat has stable three-dimensional structure, and its basic structure and manner of composition are obviously different from those of scar dermal tissue.

Background: Since the three-dimensional (3-D) structure of dermal tissue has an important role in regulating cell behavior and directing the wound healing process, the characteristic of the 3-D structure of dermal tissue needs to be clarified. Objective: To explore the different 3-D structures between normal and scar dermal tissues. Material and Methods: Phase-contrast microtomography with synchrotron radiation technology was applied to detect the 3-D structure of dermal tissues. Results: The normal dermal tissue consists of elliptical structures formed by fiber bundles interwoven in a helical manner. A regular louver-like structure was observed on the fibers. In scar tissue, the fiber bundles were arrayed in parallel, the louver-like structures were disordered. Conclusion: The study demonstrates the mesoscopic difference between normal dermal tissue and scar tissue, suggests that the high level of interweaving capability of collagen is compromised/lost when dermal tissue is injured, and provides a basis for future studies.

X-ray fluorescence computed tomography is a stimulated emission tomography that allows nondestructive reconstruction of the elements distribution in the sample, which is important for biomedical investigations. Owing to the high flux density and easy energy tunability of highly collimated synchrotron X-rays, it is possible to apply X-ray fluorescence CT to biomedical samples. Reported in the present paper, an X-ray fluorescence CT system was established at Shanghai Synchrotron Radiation Facility for the investigations of trace elements distribution inside biomedical samples. By optimizing the experiment setup, the spatial resolution was improved and the data acquisition process was obviously speeded up. The maximum-likelihood expectation-maximization algorithm was introduced for the image reconstruction, which remarkably improved the imaging accuracy of element distributions. The developed system was verified by the test sample and medical sample respectively. The results showed that the distribution of interested elements could be imaged correctly, and the spatial resolution of 150 m was achieved. In conclusion, the developed system could be applied to the research on large-size biomedical samples, concerning imaging accuracy, spatial resolution and data collection time.

Adenosine, thymidine, guanosine, cytidine and uridine form the building blocks of ribose nucleic acid (RNA) and deoxyribose nucleic acid (DNA). Nucleosides and their derivants are all have biological activities. Some of them can be used as medicine directly or as materials to synthesize other medicines. It is meaningful to detect the component and content in nucleosides mixtures. In the present paper, components and contents of the mixtures of adenosine, thymidine, guanosine, cytidine and uridine were analyzed. THz absorption spectra of pure nucleosides were set as standard spectra. The mixture's absorption spectra were analyzed by linear regression with non-negative constraint to identify the components and their relative content in the mixtures. The experimental and analyzing results show that it is simple and effective to get the components and their relative percentage in the mixtures by terahertz time domain spectroscopy with a relative error less than 10%. Component which is absent could be excluded exactly by this method, and the error sources were also analyzed. All the experiments and analysis confirms that this method is of no damage or contamination to the sample. This means that it will be a simple, effective and new method in biochemical materials analysis, which extends the application field of THz-TDS.

Synchrotron-radiation computed tomography has been applied in many research fields. Here, PITRE (Phase-sensitive X-ray Image processing and Tomography REconstruction) and PITRE_BM (PITRE Batch Manager) are presented. PITRE supports phase retrieval for propagation-based phase-contrast imaging/tomography (PPCI/PPCT), extracts apparent absorption, refractive and scattering information of diffraction enhanced imaging (DEI), and allows parallel-beam tomography reconstruction for conventional absorption CT data and for PPCT phase retrieved and DEI-CT extracted information. PITRE_BM is a batch processing manager for PITRE: it executes a series of tasks, created via PITRE, without manual intervention. Both PITRE and PITRE_BM are coded in Interactive Data Language (IDL), and have a user-friendly graphical user interface. They are freeware and can run on Microsoft Windows systems via IDL Virtual Machine, which can be downloaded for free and does not require a license. The data-processing principle and some examples of application will be presented.