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1. Markers for thymic epithelium: PAX-8, CD117, CD5, cytokeratin profile (high molecular weight cytokeratins), p63 2. Markers for lymphoid stroma: CD1a, CD3, TdT [1, 2]

S100, CD56, PGP 9.5, myelin basic protein, glial fibrillary acidic protein (GFAP), and neurofilaments

Normal breast tissue comprises mesenchymal and epithelial components, which in their turn includes ductal and acinar (lobular) and myoepithelial components with each cell type having its characteristic immunoprofile. The immunoprofile of breast tumors depends on the origin of neoplastic cells.

RCC, PAX-8, PAX-2, GATA-3, CD10, CD117, AMACR, human kidney injury molecule-1 (KIM-1), carbonic anhydrase IX (CAIX), TFE-3, DOG-1, cytokeratin profile, and vimentin [1, 2].

Ki-67 is a nonhistone nuclear protein expressed in active cell cycles. The expression of Ki-67 begins in the G1 phase and persists during the active phases of cell cycle throughout the S, G2, and M phases. Ki-67 is undetectable in the G0 phase or in the initial stage of the G1 phase and during DNA repair. The expression of Ki-67 strongly correlates with the intensity of cell proliferation and tumor grade. In routine histopathology, Ki-67 is an important marker for the assessment of cell proliferation. The Ki-67 index is an important criterion for tumor diagnosis (benign, borderline, malignant, low- or high-grade tumor). Furthermore, it is a helpful marker to differentiate between atrophy, thermal alterations, and dysplasia. The irregular accumulation of Ki-67-positive cells in different tissue types would suggest a tendency of the cells to escape the regulation mechanisms. In stratified squamous epithelium, the expression of Ki-67 in more than 30% of the full thickness of the epithelium above the suprabasal layers signifies an abnormal or dysplastic behavior of the epithelium. The Ki-67 index is also an important parameter to distinguish between high-grade and low-grade lymphoma.

Immunohistochemistry is a powerful and sensitive diagnostic tool for tumor diagnosis that requires high level of practical and theoretical knowledge. The precise tumor diagnosis begins with the adequate processing of tissue samples and includes the standardized stain technique, the optimal choice of diagnostic antibody panels, and ends with critical interpretation of stain results. In order to utilize all the benefits of immunohistochemistry and to minimize the possibilities of errors in tumor diagnosis, we recommend to consider the following points: 1. Initially it is important to remember that the careful histopathologic examination and clinical correlation remain the cornerstone of morphologic diagnosis. The immunoprofiling is to support or rule out one or more of possible differential diagnoses. 2. The laboratory of immunohistochemistry must be under the supervision of well-trained pathologist, highly skilled in methods and techniques of immunohistochemistry and has the necessary morphologic knowledge to do good and critical interpretation of immunohistochemical staining results. 3. The single marker immunohistochemistry is one of the most frequent sources of errors in tumor diagnosis. No single marker can be relied on exclusively. The use of adequate panel of antibodies helps to avoid misinterpretation; it is always advisable to confirm or exclude the diagnosis by two or more additional immunohistochemical markers. 4. Knowledge of the nature of targeted antigens is an important factor in the interpretation of the results. The following details are always to consider: The expression pattern of the antigens (nuclear, cytoplasmic, membranous, or extracellular). Stability of antigens during tissue processing. Optimal and standardized tissue fixation and processing and as a rule, bad H&E sections mean bad immunohistochemistry results. Histopathologists deal with neoplasia with heterogeneous cell populations with high potential of genotypic and phenotypic variations. The reason for the atypical antigen expression can be in the biology of the tumor or the nature of the antibodies used. 5. Features of any new antibody must be carefully studied, and the following parameters are to consider: Type of the antibody: polyclonal or monoclonal in addition to the clone type of the monoclonal antibody. Sensitivity and specificity of the antibody in addition to the recommended dilution of concentrated antibodies. Care must be exercised when using newly developed antibodies. New antibodies are often introduced as being highly specific, but after prolonged use or testing on tissue microarrays, many of them prove to be less specific. The specificity and sensitivity of used detection system. 6. The standardization of the immunohistochemical staining method is one of the essential factors for correct interpretation of stain results. Positive and negative controls are valuable for good interpretation. 7. The interpretation and documentation of immunohistochemical results must be standardized. It is not enough to interpret the staining result as positive or negative. Quality and intensity of stain and staining pattern must be also considered and documented, and any conflicting results must be analyzed. Standardized reporting is very helpful in organizing the information to reach an accurate diagnosis. 8. Despite the high sensitivity of immunohistochemistry and the large number of available antibodies, immunohistochemistry—as any method—has its own limits. We should never force the diagnosis based on unclear or unspecific results. Some cases must be clarified or confirmed by additional methods. The detection of specific translocations or other genetic abnormalities associated with various types of neoplasia by molecular methods is an example where we need other methods to obtain a precise tumor diagnosis.

Experiments and numerical simulations of various angles of wedge indenters into face-centered cubic single crystal were performed under plane strain conditions. In the experiments, the included ang ...

Introduction: Tumors with histological features of pilocytic astrocytoma but with increased mitotic activity and additional high grade features (i.e. microvascular proliferation, necrosis) have been designated anaplastic pilocytic astrocytomas (APA). Patients with such tumors are thought to have an [for full text, please go to the a.m. URL], Joint-Meeting of the German Society for Neuropathology and Neuroanatomy (DGNN) and the Scandinavian Neuropathological Society (SNS)

A two-dimensional deformation field on an indented single crystal, where the only nonzero lattice rotation occurs in the plane of deformation and only three effective in-plane slip systems are activated, is investigated both experimentally and numerically. ElectronBackscatter Diffraction (EBSD) is utilized to probe the lattice rotation field on the sample. The lattice rotation field is utilized to calculate the two non-zero components of Nye'sdislocation density tensor, which serves as a link between plastic and elastic deformation states. The enhanced accuracy of EBSD enabled measurements of the net Burgers vector density, and a new quantity β, which monitors the activity of slip systems in the deformed zone. The β-field is compared to the slip system activity obtained by analytical solution and also by crystal plasticity simulations. A qualitative comparison of the three methods confirms that the β-field obtained experimentally agrees with the slip system activity obtained analytically and by numerical methods. QC 20190429

The asymptotic stress and deformation fields associated with the contact point singularity of a nearly-flat wedge indenter impinging on a specially-oriented single face-centered cubic crystal are derived analytically in a companion paper. In order to investigate the extent of the asymptotic fields, the indentation process is simulated numerically using single crystal plasticity. The quasistatically translating asymptotic fields consist of four angular elastic sectors separated by plastically deforming sector boundaries, as predicted in the companion paper. The asymptotic stress distributions are in accord with the analytical predictions. In addition, simulations are performed for a wedge indenter with a 90° included angle in order to investigate the consequences of finite deformation and finite lattice rotation. Several salient features of the deformation field for the nearly-flat indenter persist in the deformation field for the 90° wedge indenter. The existence of the salient features is validated by comparison to experimental measurements of the lower bound on geometrically necessary dislocation (GND) densities.

Electron Backscatter Diffraction (EBSD) based Orientation Imaging Microscopy (OIM) is used routinely at ~500 materials laboratories worldwide for the characterization and development of diverse crystalline materials. Statistically significant data sets (~107 individual EBSD measurements) can be collected and analyzed within time periods of acceptable beam stability (~105s). However, limitations in angular and spatial resolution have motivated a continued search for more robust EBSD-based methods. Herein is a gathered presentation of advanced techniques in use, intended as a guide to researchers in selecting the most appropriate method for their work. Wilkinson’s method has been shown to increase angular resolution nearly two orders of magnitude to ±0.006°, facilitating measurement of elastic strain, lattice curvature, and dislocation density. A simulated pattern adaptation of Wilkinson’s method extends these measurement capabilities to polycrystalline materials, by avoiding the need for an experimental strain free reference pattern. The angular resolution limit obtained is ~0.04°. Accurate pattern center calibration, essential to the high resolution methods, is accomplished by parallelization of band edges projected onto a sphere centered at the interaction volume. FFT powered cross-correlation functions improve the spatial resolution near grain boundaries and correct for measurement inaccuracies induced by overlapping patterns. To corroborate these claims, exemplary results taken from a wedge-indented nickel single crystal, cold-worked copper polycrystal, and rolled nickel polycrystal are shown.

A single nickel crystal is indented with a wedge indenter such that a two-dimensional deformation state with three effective plane strain slip systems is induced. The in-plane lattice rotation of the crystal lattice is measured with a three micrometer spatial resolution using Orientation Imaging Microscopy (OIM). All non-zero components of the Nye dislocation density tensor are calculated from the lattice rotation field. A rigorous analytical expression is derived for the lower bound of the total Geometrically Necessary Dislocation (GND) density. Existence and uniqueness of the lower bound are demonstrated, and the apportionment of the total GND density onto the effective individual slip systems is determined. The lower bound solution reduces to the exact solution under circumstances in which only one or two of the effective slip systems are known to have been activated. The results give insight into the active slip systems as well as the dislocation structures formed in the nickel crystal as a result of the wedge indentation.

Introduction: Tumors with histological features of pilocytic astrocytoma but with increased mitotic activity and additional high grade features (i.e. microvascular proliferation, necrosis) have been designated anaplastic pilocytic astrocytomas (APA). Patients with such tumors are thought to have an [for full text, please go to the a.m. URL]

Plastic deformation in metals is a complex phenomenon and is result of competition between different complicated mechanisms, and among all, dislocation nucleation and motion are the most dominant ones. Dislocation evolution is known to be a multiscale phenomenon, and has been incorporated to crystal plasticity theories to analyze the size effect in metals for almost a decade ago. Although the theories suffice to predict the size effect in metals, they are largely phenomenological. Here a novel experimental method is developed to resolve the complexity in plastic deformation due to dislocations and to extract new material length scales that can be incorporated to numerical models. A continuum-based quantity: the geometrically necessary dislocation density (GND) that describes the signed part of the overall dislocations is measured on a nickel single crystal sample using recently developed high resolution electron backscatter diffraction (HR-EBSD) over different field of view, 90 μm^2 − 1mm^2 with various step sizes, 50 nm to 2, 500 nm . The net Burgers vector density, which includes the information of the direction of the overall dislocation motion and also quantifies the flux of atoms changing positions due to dislocations, is measured for the first time using continuum methods. A new parameter, β, that is extracted from the net Burger vector density to monitor dislocation activity on crystallographic slip planes is measured. Measurements reveals patterning in GND densities and a distribution of length scales rather than a single length scale as assumed. The length scales, such as dislocation spacing, and dislocation cell sizes are quantified. The linear relationship between dislocation spacing and dislocation cell size is obtained, where the slope of the linear fit varies with different crystallographic slip systems and the number of the active slip systems. The slope ranges between 23-29 for dominantly single slip regions, whereas it ranges between 13-16 for multislip regions, which agrees with the findings from TEM analysis in the literature showing how a continuum based method can be used to obtain same material parameters. The experimental measurements and the assumptions are elaborated in a detailed analysis. The effect of step size in EBSD results is presented, and the information loss with increasing the step size is shown. The uncertainty in GND density from the HR-EBSD measurements is found to be 10^13, which is two order of magnitude less than results from traditional diffraction methods. The effect of dislocation mobility on microstructure evolution has been also investigated, specifically tantalum single crystal specimens tested at 77 K and 293 K. The results unraveled occurrences of different deformation mechanisms: kink shear, and twinning at low temperatures. Interactions between dislocations and twin formations are observed and striking microstructure differences are examined. The dislocations density measurement results on tantalum are unique in the experimental sense and data can be used to extract length scale information. The experimental observations have been exploited to build the foundations of a numerical model. The effect of microstructure evolution on mechanical response has been investigated numerically based upon experimental observations. One of the main outcome of the experimental analysis -the variation of GND densities in cell walls- has been incorporated into a strain gradient plasticity framework. The proposed model is demonstrated with constrained shear and pure bending problems. The results presented show patterning in the GND density profile depending on the prescribed initial variation of the saturation value of GND densities and also change in overall mechanical response depending on the complexity of the prescribed profile.

The preparation and characterization of a series of spin-crossover ferric complexes with the composition [Fe(X-SalEen)2]Y, where X-SalEen results from the Schiff-base condensation of X-substituted salicylaldehyde and N-ethylethylenediamine, are reported. Several of the complexes exhibit a gradual, but complete, spin-crossover transition from high spin to low spin in the solid state, whereas certain complexes exhibit an incomplete transition and there is a “plateau” in the Ffl/Fe vs. temperature curve. One compound, [Fe(3-OCH~-SalEen)2]PF6, experiences a sudden spin-crossover phase transition. The conversion from high spin to low spin occurs within a 2’ range around the temperature 159 K. A sensitivity of physical properties to exact compound preparation is demonstrated. In spite of the variation in the series, it is shown by variable-temperature s7Fe MBssbauer and EPR techniques that only two electronic states, the high-spin 6A, excited state and one low-spin Kramers doublet ground state, are thermally populated for any of the compounds. There is no evidence of an intermediate-spin state. The ground-state Kramers doublet in these complexes has one unpaired electron in an orbital which is largely d,.. in composition.