Tri-beam microscopes comprising a fs-laser beam, a Xe+ plasma focused ion beam (PFIB) and an electron beam all in one chamber open up exciting opportunities for site-specific correlative microscopy. They offer the possibility of rapid ablation and material removal by fs-laser, subsequent polishing by Xe-PFIB milling and electron imaging of the same area. While tri-beam systems are capable of probing large (mm) volumes providing high resolution microscopical characterisation of 2D and 3D images across exceptionally wide range of materials and biomaterials applications, presenting high quality/low damage surfaces to the electron beam can present a significant challenge, especially given the large parameter space for optimisation.
View Article and Find Full Text PDFThere is an increasing requirement for the acquisition of large two (2D) or three (3D) dimensional electron back scattered diffraction (EBSD) maps. It is a well-known, but largely neglected fact, that EBSD maps may contain distortions. These include long-range distortions, which can be caused by the interaction of the electron beam with the sample geometry and it can also arise from sample or beam drift.
View Article and Find Full Text PDFThe data presented in this DiB article are the outcome of a survey implemented in a Berlin neighborhood from January to March 2018. The data consist of socio-demographic, attitudinal and perception questions, and, most importantly, a discrete choice experiment. This dataset is complementary to the full research article, "Economic valuation of street-level urban greening: A case study from an evolving mixed-use area in Berlin" [1].
View Article and Find Full Text PDFImproving outcomes in colorectal cancer requires more accurate modelling of the disease in humans, allowing more reliable pre-clinical assessment of potential therapies. Novel imaging techniques are necessary to improve the longitudinal assessment of disease burden in these models, reducing the number of animals required for translational studies. This report describes the development of an immune-competent syngeneic orthotopic murine model of colorectal cancer, utilising caecal implantation of CT26 cells stably transfected with the luciferase gene into immune-competent BALB/c mice, allowing serial bioluminescent imaging of cancer progression.
View Article and Find Full Text PDFWe demonstrate the capability of a novel Electron Backscatter Diffraction (EBSD) dictionary indexing (DI) approach by means of orientation mapping of a highly deformed graded microstructure in a shot peened Aluminium 7075-T651 alloy. A low microscope accelerating voltage was used to extract, for the first time from a bulk sample, statistically significant orientation information from a region close to a shot crater, showing both recrystallized nano-grains and heavily deformed grains. We show that the robust nature of the DI method allows for faster acquisition of lower quality patterns, limited only by the camera hardware, compared to the acquisition speed and pattern quality required for the conventional Hough indexing (HI) approach.
View Article and Find Full Text PDFNrf2 is a transcription factor that regulates cellular stress response and irinotecan-metabolising pathways. Its aberrant activity has been reported in a number of cancers, although relatively few studies have explored a role for Nrf2 in colorectal cancer (CRC). This study assessed the expression of Nrf2 in patient CRC tissues and explored the effect of Nrf2 modulation alone, or in combination with irinotecan, in human (HCT116) and murine (CT26) cell lines and in an orthotopic syngeneic mouse model utilising bioluminescent imaging.
View Article and Find Full Text PDFHere we examine the potential of serial Broad Ion Beam (BIB) Ar ion polishing as an advanced serial section tomography (SST) technique for destructive 3D material characterisation for collecting data from volumes with lateral dimensions significantly greater than 100µm and potentially over millimetre sized areas. Further, the associated low level of damage introduced makes BIB milling very well suited to 3D EBSD acquisition with very high indexing rates. Block face serial sectioning data registration schemes usually assume that the data comprises a series of parallel, planar slices.
View Article and Find Full Text PDFUltramicroscopy
February 2016
Ga(+) Focused Ion Beam-Scanning Electron Microscopes (FIB-SEM) have revolutionised the level of microstructural information that can be recovered in 3D by block face serial section tomography (SST), as well as enabling the site-specific removal of smaller regions for subsequent transmission electron microscope (TEM) examination. However, Ga(+) FIB material removal rates limit the volumes and depths that can be probed to dimensions in the tens of microns range. Emerging Xe(+) Plasma Focused Ion Beam-Scanning Electron Microscope (PFIB-SEM) systems promise faster removal rates.
View Article and Find Full Text PDFColorectal cancer (CRC) is the third most common carcinoma worldwide and despite advances in treatment, survival for patients with metastatic disease remains poor. With nearly 50% of patients developing metastases, in vivo investigation is essential to improve outcomes for these patients and numerous murine models of CRC have been developed to allow the study of chemoprevention and chemotherapy, in addition to improving our understanding of the pathogenesis of CRC. Selecting the most appropriate murine model for a specific application will maximize the conversion of potential therapies from the laboratory to clinical practice and requires an understanding of the various models available.
View Article and Find Full Text PDFThe Zr-based bulk metallic glasses (BMGs) are a new family of attractive materials with good glass-forming ability and excellent mechanical properties, such as high strength and good wear resistance, which make them candidates for structural and biomedical materials. Although the mechanical behavior of BMGs has been widely investigated, their deformation mechanisms are still poorly understood. In particular, their poor ductility significantly impedes their industrial application.
View Article and Find Full Text PDFEpithelial ovarian cancer (EOC) metastasis to the omentum requires implantation and angiogenesis. We propose that prometastatic changes in the omental endothelium (for angiogenesis) and mesothelium (for implantation) are critical. We investigated the expression of angiogenic proteases [cathepsin D (CD), cathepsin L (CL), and matrix metalloproteinase 2 (MMP2) and MMP9] and vascular endothelial growth factor A (VEGFA) in the mesothelium and endothelium of omentum from patients with EOC with omental metastases and control patients with benign ovarian tumors.
View Article and Find Full Text PDFIn-situ synchrotron x-ray experiments have been used to follow the evolution of the diffraction peaks for crystalline dendrites embedded in a bulk metallic glass matrix subjected to a compressive loading-unloading cycle. We observe irreversible diffraction-peak splitting even though the load does not go beyond half of the bulk yield strength. The chemical analysis coupled with the transmission electron microscopy mapping suggests that the observed peak splitting originates from the chemical heterogeneity between the core (major peak) and the stiffer shell (minor peak) of the dendrites.
View Article and Find Full Text PDFEpithelial ovarian cancer (EOC) metastasizes transcoelomically to the peritoneum and omentum, and despite surgery and chemotherapy, recurrent disease is likely. Metastasis requires the induction of proangiogenic changes in the omental microenvironment and EOC-induced omental angiogenesis is currently a key therapeutic target. In particular, antiangiogenic therapies targeting the vascular endothelial growth factor A (VEGFA) pathway are commonly used, although, with limited effects.
View Article and Find Full Text PDFObjectives: Despite an increasing research demand for human microvascular endothelial cells, isolation of primary endothelial cells from human tissue remains difficult. The omentum, a highly vascular visceral adipose tissue, could provide an excellent source of these cells.
Methods: A reliable method to isolate HOMECs has been developed.
The highest expression level of a 70-kDa heat shock protein family member Hspa2 is detected specifically in meiotic and post-meiotic male germ cells, which is reflected by original name of this protein, i.e., testis-specific Hsp70.
View Article and Find Full Text PDFPhilos Trans A Math Phys Eng Sci
May 2008
The non-classical problem of fracture mechanics of composites compressed along the layers with interfacial cracks is analysed. The statement of the problem is based on the model of piecewise homogeneous medium, the most accurate within the framework of the mechanics of deformable bodies as applied to composites. The condition of plane strain state is examined.
View Article and Find Full Text PDFExpression of constitutively active heat shock transcription factor 1 (HSF1) in mouse spermatocytes induces apoptosis and leads to male infertility. We report here that prior to the onset of massive apoptosis caused by expression of active HSF1 in spermatocytes a marked reduction in spermatocyte-specific Hsp70.2 mRNA and protein levels occurs.
View Article and Find Full Text PDFThe Hsp70.2/Hst70 gene, which belongs to the 70 kDa heat-shock protein (HSP) family, is expressed specifically in primary spermatocytes and spermatids. The regulatory elements required for a high level of testis-specific expression of the gene are placed between the two major transcription start sites T1 and T2 (approximately 350 and 115 bp upstream of the starting ATG codon).
View Article and Find Full Text PDFAccumulation of inducible heat shock proteins (e.g. Hsp70i) during cellular stress confers thermotolerance, reduces the consequences of damage and facilitates cellular recovery, while abrogation of Hsp70i expression renders sensitivity to apoptosis.
View Article and Find Full Text PDFBackground: The objective of the present study was to test the effectiveness of ultrasound-guided high-energy extracorporeal shock-wave treatment in symptomatic chronic calcareous tendinopathy of the shoulder rotator cuff, and to assess the morphology of the hydroxyapatite deposits before and after this treatment.
Methods: The study involved 80 patients who suffered from calcification of the rotator cuff. These patients were treated with an instrument with electromagnetic induction of shock-waves (Doli-Lithotripter, Dornier, Munich, Germany) under continuous ultrasound location of the treatment focus.
The development of hypothyroidism and the forming of a goiter are well-known complications associated with lithium medications. But there are also occasional references to cases of hyperthyroidism in the wake of both continual and of discontinued lithium medication. In the case being reported on here of a lady patient aged 64 and suffering from a toxic adenoma not recognized at the time, thyrotoxicosis accompanied by above-normal FT-3 results and the characteristic clinical symptoms developed when lithium medication was discontinued.
View Article and Find Full Text PDFQuantitation of the C3 component of complement by single radial immunodiffusion is subject to error because the C3 molecule has several antigenic determinants and anti-C3 sera differ in their specificity to these determinants. C3 was measured in plasma (ethylenediaminetetraacetate anticoagulant) and serum, in five normal individuals, by use of four such commercial kits. The effects of ethylenediaminetetraacetate and of incubation at -20, 4, and 37 degrees C for 1, 2, and 7 days were investigated.
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