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Cardiovascular diseases are closely related to structural blood capillaries lesions. Herein, microscopic investigations of mouse blood capillaries were performed at multiple spatial resolution by using synchrotron X-ray in-line phase contrast tomography and scanning transmission X-ray microscopy (STXM). The chemically fixed blood capillaries without any contrast agents were selected. For the first time, a periodic bamboo-shaped structure was observed at nanoscale resolution by STXM, and the three-dimensional tomographic slices at sub-micrometer resolution further confirmed the periodic wave profile of the blood capillaries. Then, a periodic microstructural model was suggested based on the microscopic images. By using high-performance imaging techniques, this work provides a better understanding of the relationship between the structure and function of blood capillaries, will be helpful in elucidating the causes of cardiovascular system diseases.
Three-dimensional X-ray imaging of living specimens is challenging due to the limited resolution of conventional absorption contrast X-ray imaging and potential irradiation damage of biological specimens. In this letter, we present microtomography of a living specimen combining phase-contrast imaging and a Fourier-based iterative algorithm termed equally sloped tomography. Non-destructive 3D imaging of an anesthetized living yellow mealworm Tenebrio molitor was demonstrated with a relatively low dose using synchrotron generated X-rays. Based on the high-quality 3D images, branching tracheoles and different tissues of the insect in a natural state were identified and analyzed, demonstrating a significant advantage of the technique over conventional X-ray radiography or histotomy. Additionally, the insect survived without problem after a 1.92-s X-ray exposure and subsequent absorbed radiation dose of ∼1.2 Gy. No notable physiological effects were observed after reviving the insect from anesthesia. The improved static tomographic method demonstrated in this letter shows advantage in the non-destructive structural investigation of living insects in three dimensions due to the low radiation dose and high resolution capability, and offers many potential applications in biological science.
When and under what circumstances domestication related traits evolved in soybean (Glycine max) is not well understood. Seed size has been a focus of archaeological attention because increased soybean seed weight/size is a trait that distinguishes most modern soybeans from their ancestors; however, archaeological seed size analysis has had limited success. Modern domesticated soybean has a significantly higher oil content than its wild counterpart so oil content is potentially a source of new insight into soybean domestication. We investigated soybean oil content using X-ray computed tomography (CT; specifically, synchrotron radiation X-ray CT or SRX-CT) of charred, archaeological soybean seeds. CT identified holes in the specimens that are associated with oil content. A high oil content facilitates the development of small holes, whereas a high protein content results in larger holes. The volume of small holes increased slowly from 7,500 to 4,000 cal B.P. We infer that human selection for higher oil content began as early as 7,500 cal B.P. and that high oil content cultivars were well established by 4,000 cal B.P.
X‐ray imaging techniques significantly advanced our understanding of materials and biology, among which phase contrast X‐ray microscopy has obvious advantages in imaging biological specimens which have low contrast by conventional absorption contrast microscopy. In this paper, three‐dimensional microstructure of arthropod with high contrast has been demonstrated by synchrotron X‐ray in‐line phase contrast tomography. The external morphology and internal structures of an earthworm were analyzed based upon tomographic reconstructions with and without phase retrieval. We also identified and characterized various fine structural details such as the musculature system, the digestive system, the nervous system, and the circulatory system. This work exhibited the high efficiency, high precision, and wide potential applications of synchrotron X‐ray phase contrast tomography in nondestructive investigation of low‐density materials and biology.
The development of three-dimensional (3D) single-cell imaging and protein quantitative methods can provide more comprehensive information for diagnoses. We report the design and synthesis of a multisignal nanoprobe (AuGdNC@BSA-CV) for single-cell 3D imaging and quantifying the integrin αIIbβ3 using correlated synchrotron radiation soft X-ray tomography microscopy and an iterative tomographic algorithm termed equally sloped tomography for the first time. Moreover, on the basis of the Au or Gd content of our nanoprobe, the number of integrin αIIbβ3 on a single cell also can be accurately quantified (1.5 × 107 per cell) via inductively coupled plasma mass spectrometry.
Casting had symbolic significance and was strictly controlled in the Shang dynasty of ancient China. Vessel casting was mainly distributed around the Shang capital, Yin Ruins, which indicates a rigorous centralization of authority. Thus, for a casting mold to be excavated far from the capital region is rare. In addition to some bronze vessel molds excavated at the Buyao Village site, another key discovery of a bronze vessel mold occurred at Daxinzhuang. The Daxinzhuang site was a core area in the east of Shang state and is an important site to study the eastward expansion of the Shang. Here, combining synchrotron X-rays and other physicochemical analysis methods, nondestructive three-dimensional structure imaging and different elemental analyses were conducted on this mold sherd. Through high penetration X-ray tomography, we obtained insights on the internal structure and discovered some pores. We infer that the generation of pores inside the casting mold sherd was used to enhance air permeability during casting. Furthermore, we suppose that the decorative patterns on the surface were carved and not pasted onto it. Considering the previous compositional studies of bronze vessels, the copper and iron elements were analyzed by different methods. Unexpectedly, a larger amount of iron than of copper was detected on the surface. According to the data analysis and archaeological context, the source of iron on the casting mold sherd could be attributed to local soil contamination. A refined compositional analysis confirms that this casting mold was fabricated locally and used for bronze casting.
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