Real-space investigation of polarons in hematite FeO.

In polarizable materials, electronic charge carriers interact with the surrounding ions, leading to quasiparticle behavior. The resulting polarons play a central role in many materials properties including electrical transport, interaction with light, surface reactivity, and magnetoresistance, and polarons are typically investigated indirectly through these macroscopic characteristics. Here, noncontact atomic force microscopy (nc-AFM) is used to directly image polarons in FeO at the single quasiparticle limit.

Resolving the intrinsic short-range ordering of K ions on cleaved muscovite mica.

Muscovite mica, KAl(SiAl)O(OH), is a common layered phyllosilicate with perfect cleavage planes. The atomically flat surfaces obtained through cleaving lend themselves to scanning probe techniques with atomic resolution and are ideal to model minerals and clays. Despite the importance of the cleaved mica surfaces, several questions remain unresolved.

Growth-rate model of epitaxial layer-by-layer growth by pulsed-laser deposition.

We present a numerical model of epitaxial thin-film growth applicable for pulsed-laser deposition on a single crystalline substrate. The model is based on rate equations describing the time development of monolayer coverages and of densities of movable particles on atomically flat terraces. Numerical solution of the equations showed that the time dependence of surface roughness obeys a scaling law, the exponent of which depends on probabilities of various atomistic processes included in the simulation model.

Effect of pulse laser frequency on PLD growth of LuFeO explained by kinetic simulations of in-situ diffracted intensities.

Atomistic processes during pulsed-laser deposition (PLD) growth influence the physical properties of the resulting films. We investigated the PLD of epitaxial layers of hexagonal LuFeO[Formula: see text] by measuring the X-ray diffraction intensity in the quasiforbidden reflection 0003 in situ during deposition. From measured X-ray diffraction intensities we determined coverages of each layer and studied their time evolution which is described by scaling exponent [Formula: see text] directly connected to the surface roughness.

Effective algorithm for simulations of layer-by-layer growth during pulsed-laser deposition.

The atomistic simulation of materials growing in the layer-by-layer mode by the pulsed-laser deposition is a significant challenge mainly due to the short timescales in which the fastest processes on the surface occur together with long periods between pulses. We present a kinetic Monte Carlo algorithm which overcomes the scaling problem by approximation of fast diffusion and by neglecting complex chemical processes. The atomic diffusion is modeled as a two-dimensional gas of material units on each layer.

Explainable classifier for improving the accountability in decision-making for colorectal cancer diagnosis from histopathological images.

Pathologists are responsible for cancer type diagnoses from histopathological cancer tissues. However, it is known that microscopic examination is tedious and time-consuming. In recent years, a long list of machine learning approaches to image classification and whole-slide segmentation has been developed to support pathologists.

Self-ordering of chemisorbed PTCDA molecules on Ge(001) driven by repulsive forces.

Realization of future hybrid electronic devices combining organic and inorganic semiconductors requires a well-defined interface between both components. Such an interface can be formed generally by self-ordering of organic molecules on inorganic substrates, which is usually hindered by strong covalent bonds to the semiconductor surface. In this paper, the 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) molecules were unexpectedly found to form a locally self-ordered monolayer on a strongly interacting semiconductor surface of the Ge(001).

Self-assembly of a two-dimensional molecular layer in a nonhomogeneous electric field: Kinetic Monte Carlo simulations.

Behavior of mobile adsorbed species can be affected by the presence of a strong non-homogeneous electric field. Such a field exists in the proximity of a biased tip of the scanning tunneling microscope. Depending on the electronic properties of the adsorbate and the polarity of the electric field, self-assembly of ordered structures on the surface can be facilitated or prevented.

Local electronic structure of doping defects on Tl/Si(111)1x1.

The Tl/Si(111)1 × 1 surface is a representative of a 2D layer with Rashba-type spin-split electronic bands. To utilize the spin polarization, doping of the system should be understood on atomic level. We present a study of two types of atomic defects predicted to dope the considered electronic system - Si-induced vacancies and defects associated with the presence of extra Tl atoms.

Pair Correlation Function of a 2D Molecular Gas Directly Visualized by Scanning Tunneling Microscopy.

The state of matter in fluid phases, determined by the interactions between particles, can be characterized by a pair correlation function (PCF). At the nanoscale, the PCF has been so far obtained experimentally only by means of reciprocal-space techniques. We use scanning tunneling microscopy (STM) at room temperature in combination with lattice-gas kinetic Monte Carlo (KMC) simulations to study a two-dimensional gas of highly mobile molecules of fluorinated copper phthalocyanine on a Si(111)/Tl-(1×1) surface.

Electric-field-controlled phase transition in a 2D molecular layer.

Self-assembly of organic molecules is a mechanism crucial for design of molecular nanodevices. We demonstrate unprecedented control over the self-assembly, which could allow switching and patterning at scales accessible by lithography techniques. We use the scanning tunneling microscope (STM) to induce a reversible 2D-gas-solid phase transition of copper phthalocyanine molecules on technologically important silicon surface functionalized by a metal monolayer.

Adsorption of ethylene on Sn and In terminated Si(001) surface studied by photoelectron spectroscopy and scanning tunneling microscopy.

Interaction of ethylene (C2H4) with Si(001)-Sn-2 × 2 and Si(001)-In-2 × 2 at room temperature has been studied using core level (C 1s) X-ray photoelectron spectroscopy with synchrotron radiation and scanning tunneling microscopy. Sn and In form similar dimer chains on Si(001)2 × 1, but exhibit different interaction with ethylene. While ethylene adsorbs on top of Sn dimers of the Si(001)-Sn-2 × 2 surface, the Si(001)-In-2 × 2 surface turned out to be inert.

Desorption-induced structural changes of metal/Si(111) surfaces: kinetic Monte Carlo simulations.

We used a configuration-based kinetic Monte Carlo model to explain important features related to formation of the (√3×√3)R30° mosaic of metal and semiconductor atoms on the Si(111) surface. Using first-order desorption processes, we simulate the surprising zero-order desorption spectra, reported in some cases of metal desorption from the Si(111) surface. We show that the mechanism responsible for the zerolike order of desorption is the enhanced desorption from disordered areas.

Prolonged treatment of chronic renal insufficiency, acquired cystic kidney disease, simultaneous precancerous lesions and multiple tumors of left kidney.

Purpose Of The Investigation: Description of precancerous lesions and kidney tumors developing in a patient with chronic uremia treated by long-term hemodialysis.

Most Important Methods: Light microscopy, polarization and immunohistochemistry with CK1/CK3, CK5/6, CK7, CK8, CK20, EMA, Renal cell, CD10, Ki-67, PCNA, p53 and E-cadherin antibodies were used.

Main Findings: After 11 years of hemodialysis treatment of end-stage diabetic nephropathy and chronic tubulointerstitial nephritis an urgent left-sided nephrectomy was performed because of pain and massive intrarenal bleeding.

[Caspase 1, superoxide dismutase (D-mutase) and calretinin expression in the placenta and in the basal decidua in preeclampsia].

Objective: To determine new data related to the expression of caspase 1, superoxiddismutase and calretinin in the placenta and basal decidua in preeclampsia.

Material And Methods: Placental and basal decidua samples from 9 preeclamptic and 9 normotensive controls were analyzed using expressions of caspase 1, superoxiddismutase and calretinin assessed by immunohistochemistry.

Results: Caspase 1 was expressed in placental syncythium in preeclampsia constantly, while in the control group the expression was weak or absent.

Surgical management of bronchopulmonary carcinoid tumors: experience over 8 years and review of the literature.

Aims And Background: An increased incidence of neuroendocrine tumors in the last decade has been noticed worldwide. Our purpose was to study the characteristics, surgical approaches and outcome in patients with primary bronchopulmonary carcinoid tumors.

Methods: Between 2001 and 2007, bronchopulmonary carcinoid tumors were removed in 11 of a total of 287 patients who underwent surgery for primary lung malignancies in our tertiary referral center.

Modeling growth of one-dimensional islands: influence of reactive defects.

Influence of reactive defects on size distribution of one-dimensional islands is studied by means of kinetic Monte Carlo simulations in combination with an analytical approach. Two different models are examined: a model with anisotropically diffusing atoms irreversibly aggregating to islands, and a reversible model close to thermal equilibrium which allows atom detachment from islands during the growth. The models can be used to simulate island growth of group III metals deposited on the Si(100)2 x 1 surface at room temperature: Al, Ga (irreversible model), and In (equilibrium model).

Immunohistochemical markers of proliferation and vascularisation in preneoplastic bronchial lesions and invasive non-small cell lung cancer.

Autofluorescence bronchoscopy (AFB) has been shown to be sensitive to detect preneoplastic lesions in central lung airways system. In early stages of carcinogenesis, up-regulation of cyclooxygenase (COX)-2, Ki67 and/or increased angiogenesis may play a role by promoting the proliferation of tumoral cells and their resistance to apoptosis, as well as angiogenesis, tumor cell invasion and setting up of the metastatic process. The present study compared the expression of proliferative (COX-2, Ki67 and PCNA) and angiogenic markers (CD34 and NG2) between preneoplastic bronchial squamous dysplasia lesions and invasive squamous cell carcinoma.

Direct observation of long-range assisted formation of Ag clusters on Si(111)7 x 7.

Formation of Ag clusters on reconstructed surface Si(111)7 x 7 was for the first time observed in real time during deposition by means of scanning tunneling microscopy. The sequences of images taken at room temperature show mechanisms controlling the growth and behavior of individual Ag adatoms. Obtained data reveal new details of attractive interaction between adsorbates occupying adjacent half-unit cells of the 7 x 7 reconstruction.

Ga-rich limit of surface reconstructions on GaAs(001): atomic structure of the (4 x 6) phase.

The Ga-rich reconstruction of the GaAs(001) surface has been studied. Using scanning tunneling microscopy (STM), we have found the existence of a well-ordered (4 x 6) reconstruction under extreme Ga-rich conditions. A structure model, consisting of subsurface Ga-Ga dimers and surface Ga-As dimers, is proposed for the (4 x 6) surface.

Kinetics in surface reconstructions on GaAs(001).

We have successfully controlled the surface structures of GaAs(001) by changing incident As-molecular species. Under As4 fluxes, the c(4 x 4) reconstruction with Ga-As dimers [c(4 x 4)alpha structure] is obtained, but the formation of three As-As dimer structures [c(4 x 4)beta structure] is kinetically limited. On the other hand, the structure change from the (2 x 4), through c(4 x 4)alpha, to c(4 x 4)beta phases is observed under As2 fluxes.

Immunohistochemical study of melanocytic differentiation antigens in cutaneous malignant melanoma. A comparison of six commercial antibodies and one non-commercial antibody in nodular melanoma, superficially spreading melanoma and lentigo maligna melanoma.

In certain primary and metastatic malignant melanomas diagnostic problems may arise due to their cytologic features and/or absence of synthesis of melanin. As the "classic" combination of S-100 protein and HMB-45 may occasionally fail to stain cells of malignant melanoma, we have tested a series of commercially accessible antibodies which were so far not compared by other authors in the three most frequent subtypes of this tumor. In surgical specimens from 104 cutaneous malignant melanomas (40 nodular melanomas, 46 superficially spreading malignant melanomas and 18 lentigo maligna melanomas) the staining intensity and the proportion of neoplastic cells stained with antibodies to S-100 protein, HMB-45, NKI/C3, NKI/beteb, MART 1 (Melan A), KBA 62 and Mitf was semiquantitatively analysed.

Expression of LRP--lung resistance-related protein in the normal colorectal mucosa and in colorectal carcinoma.

Expression of LRP--lung resistance-related protein was analyzed by immunohistochemical staining with monoclonal antibody LRP-56 in 30 specimens (10 from normal colorectal tissue and 20 from colorectal carcinoma). All normal tissue samples were LRP positive. Strong LRP staining was seen in the surface epithelium and upper parts of the crypts.

Collagenous spherulosis in epithelial-myoepithelial carcinoma of the parotid gland. Histological and immunohistological study of a case.

Previously unreported histological and immunohistochemical features of collagenous spherulosis in an epithelial-myoepithelial carcinoma found in an 80-year-old woman are described. The multinodular tumor located in the right parotid gland was completely removed surgically. No local recurrence of the tumor appeared during the 22-month period of periodic checkups.

[Pulmonary thromboembolism over a 25-year period in data from the Institute of Pathology of the P.J. Safarik Medical School in Kosice].

Based on a review of archival autopsy protocols an analysis of the frequency of pulmonary thrombembolism in consecutive autopsy material is presented. The study interval for the analysis was oriented to the period between the years 1949-2000. Our analysis has shown a gradual progression of incidence of pulmonary thrombembolism, as demonstrated in relative figures.