Structure and creep of Russian reactor steels with a BCC structure

NASA Astrophysics Data System (ADS)

Sagaradze, V. V.; Kochetkova, T. N.; Kataeva, N. V.; Kozlov, K. A.; Zavalishin, V. A.; Vil'danova, N. F.; Ageev, V. S.; Leont'eva-Smirnova, M. V.; Nikitina, A. A.

2017-05-01

The structural phase transformations have been revealed and the characteristics of the creep and long-term strength at 650, 670, and 700°C and 60-140 MPa have been determined in six Russian reactor steels with a bcc structure after quenching and high-temperature tempering. Creep tests were carried out using specially designed longitudinal and transverse microsamples, which were fabricated from the shells of the fuel elements used in the BN-600 fast neutron reactor. It has been found that the creep rate of the reactor bcc steels is determined by the stability of the lath martensitic and ferritic structures in relation to the diffusion processes of recovery and recrystallization. The highest-temperature oxide-free steel contains the maximum amount of the refractory elements and carbides. The steel strengthened by the thermally stable Y-Ti nanooxides has a record high-temperature strength. The creep rate at 700°C and 100 MPa in the samples of this steel is lower by an order of magnitude and the time to fracture is 100 times greater than that in the oxide-free reactor steels.

Early detection of skin cancer via terahertz spectral profiling and 3D imaging.

PubMed

Rahman, Anis; Rahman, Aunik K; Rao, Babar

2016-08-15

Terahertz scanning reflectometry, terahertz 3D imaging and terahertz time-domain spectroscopy have been used to identify features in human skin biopsy samples diagnosed for basal cell carcinoma (BCC) and compared with healthy skin samples. It was found from the 3D images that the healthy skin samples exhibit regular cellular pattern while the BCC skin samples indicate lack of regular cell pattern. The skin is a highly layered structure organ; this is evident from the thickness profile via a scan through the thickness of the healthy skin samples, where, the reflected intensity of the terahertz beam exhibits fluctuations originating from different skin layers. Compared to the healthy skin samples, the BCC samples' profiles exhibit significantly diminished layer definition; thus indicating a lack of cellular order. In addition, terahertz time-domain spectroscopy reveals significant and quantifiable differences between the healthy and BCC skin samples. Thus, a combination of three different terahertz techniques constitutes a conclusive route for detecting the BCC condition on a cellular level compared to the healthy skin. Copyright © 2016 Elsevier B.V. All rights reserved.

Surface structure and electrochemical characteristics of Ti-V-Cr bcc-type solid solution alloys sintered with Ni

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsuji, Yoichiro; Yamamoto, Osamu; Matsuda, Hiromu

2000-07-01

Ti-V-Cr bcc-type solid solution alloys can absorb a large amount of hydrogen and be applied to active materials of the negative electrode in Ni-MH batteries. However, because of the insolubility of Ni into these alloys, the electrochemical characteristics like discharge capacity and cycle life were poor. In order to increase the discharge capacity of hydrogen absorbing alloy electrodes, Ti-V-Cr bcc-type alloy powders were sintered with Ni in order to form Ni contained surface layer on the alloy surface. As sintering temperature rose up, the surface composition changed from TiNi to Ti{sub 2}Ni. TiNi surface layer showed better electrochemical characteristics. Formore » the Ni adding method, Ni electroless plating was preferred because of good adhesion. As a result of optimized conditions, a discharge capacity of 570 mAh/g and an improvement of cycle life were achieved.« less

First-principles study of high-pressure structural phase transitions of magnesium

NASA Astrophysics Data System (ADS)

Liu, Qiuxiang; Fan, Changzeng; Zhang, Ruijun

2009-06-01

The structural phase transitions for the hcp, bcc, dhcp, and fcc of magnesium at hydrostatic pressures larger than about 200 GPa at zero temperature are studied by first-principles total energy calculations. The plane-wave basis pseudopotential method has been adopted, in which the generalized gradient approximation implanted in the CASTEP code is employed. By comparing the enthalpy differences of the hcp structure with other three structures under different pressures, it can be seen that when the pressure becomes higher than about 65, 130, and 190 GPa, the bcc, dhcp, and fcc structures become more stable relative to the hcp structure, respectively. Due to the lowest enthalpy value of the bcc structure above 65 GPa, it can be deduced that magnesium may transform to the bcc structure from the ground state hcp structure around 65 GPa, but no further phase transitions occur without additionally applying high temperature. In addition, the equation of state of magnesium is calculated, indicating that bcc structure is the softest phase.

Solid-liquid interface free energies of pure bcc metals and B2 phases

DOE PAGES

Wilson, S. R.; Gunawardana, K. G. S. H.; Mendelev, M. I.

2015-04-07

The solid-liquid interface (SLI) free energy was determined from molecular dynamics (MD) simulation for several body centered cubic (bcc) metals and B2 metallic compounds (space group: Pm3¯m ; prototype: CsCl). In order to include a bcc metal with a low melting temperature in our study, a semi-empirical potential was developed for Na. Two additional synthetic “Na” potentials were also developed to explore the effect of liquid structure and latent heat on the SLI free energy. The obtained MD data were compared with the empirical Turnbull, Laird, and Ewing relations. All three relations are found to predict the general trend observedmore » in the MD data for bcc metals obtained within the present study. However, only the Laird and Ewing relations are able to predict the trend obtained within the sequence of “Na” potentials. The Laird relation provides the best prediction for our MD data and other MD data for bcc metals taken from the literature. Overall, the Laird relation also agrees well with our B2 data but requires a proportionality constant that is substantially different from the bcc case. It also fails to explain a considerable difference between the SLI free energies of some B2 phases which have nearly the same melting temperature. In contrast, this difference is satisfactorily described by the Ewing relation. Thus, the Ewing relation obtained from the bcc dataset also provides a reasonable description of the B2 data.« less

Solid-liquid interface free energies of pure bcc metals and B2 phases

NASA Astrophysics Data System (ADS)

Wilson, S. R.; Gunawardana, K. G. S. H.; Mendelev, M. I.

2015-04-01

The solid-liquid interface (SLI) free energy was determined from molecular dynamics (MD) simulation for several body centered cubic (bcc) metals and B2 metallic compounds (space group: P m 3 ¯ m ; prototype: CsCl). In order to include a bcc metal with a low melting temperature in our study, a semi-empirical potential was developed for Na. Two additional synthetic "Na" potentials were also developed to explore the effect of liquid structure and latent heat on the SLI free energy. The obtained MD data were compared with the empirical Turnbull, Laird, and Ewing relations. All three relations are found to predict the general trend observed in the MD data for bcc metals obtained within the present study. However, only the Laird and Ewing relations are able to predict the trend obtained within the sequence of "Na" potentials. The Laird relation provides the best prediction for our MD data and other MD data for bcc metals taken from the literature. Overall, the Laird relation also agrees well with our B2 data but requires a proportionality constant that is substantially different from the bcc case. It also fails to explain a considerable difference between the SLI free energies of some B2 phases which have nearly the same melting temperature. In contrast, this difference is satisfactorily described by the Ewing relation. Moreover, the Ewing relation obtained from the bcc dataset also provides a reasonable description of the B2 data.

Solid-liquid interface free energies of pure bcc metals and B2 phases.

PubMed

Wilson, S R; Gunawardana, K G S H; Mendelev, M I

2015-04-07

The solid-liquid interface (SLI) free energy was determined from molecular dynamics (MD) simulation for several body centered cubic (bcc) metals and B2 metallic compounds (space group: Pm3̄m; prototype: CsCl). In order to include a bcc metal with a low melting temperature in our study, a semi-empirical potential was developed for Na. Two additional synthetic "Na" potentials were also developed to explore the effect of liquid structure and latent heat on the SLI free energy. The obtained MD data were compared with the empirical Turnbull, Laird, and Ewing relations. All three relations are found to predict the general trend observed in the MD data for bcc metals obtained within the present study. However, only the Laird and Ewing relations are able to predict the trend obtained within the sequence of "Na" potentials. The Laird relation provides the best prediction for our MD data and other MD data for bcc metals taken from the literature. Overall, the Laird relation also agrees well with our B2 data but requires a proportionality constant that is substantially different from the bcc case. It also fails to explain a considerable difference between the SLI free energies of some B2 phases which have nearly the same melting temperature. In contrast, this difference is satisfactorily described by the Ewing relation. Moreover, the Ewing relation obtained from the bcc dataset also provides a reasonable description of the B2 data.

Angle Resolved Photoelectron and Auger Electron Diffraction as a Structural Probe for Surfaces, Interfaces, and Epitaxial Films.

NASA Astrophysics Data System (ADS)

Li, Hong

The recently developed techniques of angle-resolved photoelectron and Auger electron diffraction (ARXPD/AED) have shown promise in identifying the structures of epitaxial films. This is due to the realization that electrons scattered by other atoms are enhanced along the forward direction. In this dissertation research, we have further investigated the capabilities of the ARXPD/AED technique. First, the complete polar angle distribution of the Auger electron intensity from Cu(001) was measured from the (100) to the (110) azimuth. The presentation of the ARAED in the form of a contour map clearly shows the relationship of the constructive and destructive interference of electron scattering to the crystallographic index of the crystal. Secondly, the angular distributions of electron emissions with initial states of 3p, 3d, 4d, and the Auger emission with electron kinetic energies ranging from 348 eV to 1477 eV were measured for single crystal Ag(001). The results show that all of these electron emissions have similar electron forward scattering enhancements along the directions of nearest and next nearest neighbour atoms in the crystal. The forward scattering enhancements do not shift as the electron kinectic energy changes. The ARXPD/AED combined with low energy electron diffraction (LEED) has been demonstrated to be a very powerful technique in probing both the long range order and the short range order of the epitaxial films. The epitaxial films studied include Co on Cu(001), Fe on Ag(001), Co on Ag(001), and Co on an ultra-thin film of Fe(001), which was epitaxially grown on Ag(001). We find that up to 20 ML thickness of high quality metastable fcc Co can be stabilized on Cu(001) at room temperature. We have directly verified that the Fe on Ag(001) is bcc. The Co on Ag(001) is neither bcc nor fcc for coverages of less than 3 ML. Thick films of Co on Ag(001) are disordered, of which a very small portion has a local structure of bcc. The bcc Co phases has been successfully stabilized on an ultra-thin film of bcc Fe(001). This is the first example of bcc Co epitaxially grown on a metal substrate at room temperature.

BCc1, the novel antineoplastic nanocomplex, showed potent anticancer effects in vitro and in vivo.

PubMed

Kalanaky, Somayeh; Hafizi, Maryam; Fakharzadeh, Saideh; Vasei, Mohammad; Langroudi, Ladan; Janzamin, Ehsan; Hashemi, Seyed Mahmoud; Khayamzadeh, Maryam; Soleimani, Masoud; Akbari, Mohammad Esmaeil; Nazaran, Mohammad Hassan

2016-01-01

In spite of all the efforts and researches on anticancer therapeutics, an absolute treatment is still a myth. Therefore, it is necessary to utilize novel technologies in order to synthesize smart multifunctional structures. In this study, for the first time, we have evaluated the anticancer effects of BCc1 nanocomplex by vitro and in vivo studies, which is designed based on the novel nanochelating technology. Human breast adenocarcinoma cell line (MCF-7) and mouse embryonic fibroblasts were used for the in vitro study. Antioxidant potential, cell toxicity, apoptosis induction, and CD44 and CD24 protein expression were evaluated after treatment of cells with different concentrations of BCc1 nanocomplex. For the in vivo study, mammary tumor-bearing female Balb/c mice were treated with different doses of BCc1 and their effects on tumor growth rate and survival were evaluated. BCc1 decreased CD44 protein expression and increased CD24 protein expression. It induced MCF-7 cell apoptosis but at the same concentrations did not have negative effects on mouse embryonic fibroblasts viability and protected them against oxidative stress. Treatment with nanocomplex increased survival and reduced the tumor size growth in breast cancer-bearing balb/c mice. These results demonstrate that BCc1 has the capacity to be assessed as a new anticancer agent in complementary studies.

Comparative study of crystallization process in metallic melts using ab initio molecular dynamics simulations

NASA Astrophysics Data System (ADS)

Debela, Tekalign T.; Wang, X. D.; Cao, Q. P.; Zhang, D. X.; Jiang, J. Z.

2017-05-01

The crystallization process of liquid metals is studied using ab initio molecular dynamics simulations. The evolution of short-range order during quenching in Pb and Zn liquids is compared with body-centered cubic (bcc) Nb and V, and hexagonal closed-packed (hcp) Mg. We found that the fraction and type of the short-range order depends on the system under consideration, in which the icosahedral symmetry seems to dominate in the body-centered cubic metals. Although the local atomic structures in stable liquids are similar, liquid hcp-like Zn, bcc-like Nb and V can be deeply supercooled far below its melting point before crystallization while the supercooled temperature range in liquid Pb is limited. Further investigations into the nucleation process reveal the process of polymorph selection. In the body-centered cubic systems, the polymorph selection occurs in the supercooled state before the nucleation is initiated, while in the closed-packed systems it starts at the time of onset of crystallization. Atoms with bcc-like lattices in all studied supercooled liquids are always detected before the polymorph selection. It is also found that the bond orientational ordering is strongly correlated with the crystallization process in supercooled Zn and Pb liquids.

``Loose spins'' in Fe/Cu/Fe(001) structures

NASA Astrophysics Data System (ADS)

Heinrich, B.; Celinski, Z.; Liao, L. X.; From, M.; Cochran, J. F.

1994-05-01

Slonczewski recently proposed a model for the exchange coupling between ferromagnetic layers separated by a nonferromagnetic spacer based on the concept of ``loose spins.'' ``Loose spins'' contribute to the total exchange energy. We have studied the role of ``loose spins'' in bcc Fe/Cu/Fe(001) structures. bcc Fe/Cu/Fe(001) trilayers deposited at room temperature were investigated extensively in our previous studies. In our ``loose spin'' studies, the Fe was added inside the Cu interlayer. Several structures were atomically engineered in order to test the behavior of ``loose spins:'' One additional atomic layer of an (Fe+Cu) alloy were located in appropriate positions in a Cu spacer. The bilinear and biquadratic exchange coupling in the above structures was quantitatively studied with FMR in the temperature range 77-370 K and with MOKE at RT.

Self assembly and shear induced morphologies of asymmetric block copolymers with spherical domains

NASA Astrophysics Data System (ADS)

Mandare, Prashant N.

2007-12-01

Microphase separated block copolymers have been subject of investigation for past two decades. While most of the work is focused on classical phases of lamellae or cylinders, spherical phases have received less attention. The present study deals with the self-assembly in spherical phases of block copolymers that results into formation of a three-dimensional cubic lattice. A model triblock copolymer with several transition temperatures is chosen. Solidification in this model system results from either the arrangement of nanospheres of minor block on a BCC lattice or by formation of physical network where the nanospheres act as crosslinks. The solid-like behavior is characterized by extremely slow relaxation modes. Long time stress relaxation of the model material was examined to distinguish between the solid and liquid behavior. Stress relaxation data from a conventional rheometer was extended to very long times by using a newly built instrument, Relaxometer. The BCC lattice structure of the material behaves as liquid over long time except at low temperatures where an equilibrium modulus is observed. This long time behavior was extended to low shear rate behavior using steady shear rheology. The zero shear viscosity observed at extremely low shear rates has a very high value that is close to the viscosity calculated from stress relaxation experiments. The steady shear viscosity decreases by several orders of magnitude over a small range of shear rates. SAXS experiments on samples sheared even at very low rates indicated loss of the BCC order that was present in the annealed samples before shearing. In the second part, response of the BCC microstructure to large stress was explored. Shearing at constant rate and with LAOS at low frequencies lead to destruction of BCC lattice. The structure recovers upon cessation of the shear with kinetics similar to the one following thermal quench. Under certain conditions, LAOS leads to formation of monodomain textures. At low frequencies, there exists an upper and lower bound on strain amplitude where mono-domain textures can be obtained. Upon alignment, the modulus drops by about 30%. Measurement of rheological properties offers an indirect method to distinguish between polycrystalline structure and monodomain texture.

Ginzburg-Landau theory for the solid-liquid interface of bcc elements

NASA Technical Reports Server (NTRS)

Shih, W. H.; Wang, Z. Q.; Zeng, X. C.; Stroud, D.

1987-01-01

Consideration is given to a simple order-parameter theory for the interfacial tension of body-centered-cubic solids in which the principal order parameter is the amplitude of the density wave at the smallest nonzero reciprocal-lattice vector of the solid. The parameters included in the theory are fitted to the measured heat of fusion, melting temperature, and solid-liquid density difference, and to the liquid structure factor and its temperature derivative at freezing. Good agreement is found with experiment for Na and Fe and the calculated anisotropy of the surface tension among different crystal faces is of the order of 2 percent. On the basis of various assumptions about the universal behavior of bcc crystals at melting, the formalism predicts that the surface tension is proportional to the heat of fusion per surface atom.

First-principles calculations, experimental study, and thermodynamic modeling of the Al-Co-Cr system.

PubMed

Liu, Xuan L; Gheno, Thomas; Lindahl, Bonnie B; Lindwall, Greta; Gleeson, Brian; Liu, Zi-Kui

2015-01-01

The phase relations and thermodynamic properties of the condensed Al-Co-Cr ternary alloy system are investigated using first-principles calculations based on density functional theory (DFT) and phase-equilibria experiments that led to X-ray diffraction (XRD) and electron probe micro-analysis (EPMA) measurements. A thermodynamic description is developed by means of the calculations of phase diagrams (CALPHAD) method using experimental and computational data from the present work and the literature. Emphasis is placed on modeling the bcc-A2, B2, fcc-γ, and tetragonal-σ phases in the temperature range of 1173 to 1623 K. Liquid, bcc-A2 and fcc-γ phases are modeled using substitutional solution descriptions. First-principles special quasirandom structures (SQS) calculations predict a large bcc-A2 (disordered)/B2 (ordered) miscibility gap, in agreement with experiments. A partitioning model is then used for the A2/B2 phase to effectively describe the order-disorder transitions. The critically assessed thermodynamic description describes all phase equilibria data well. A2/B2 transitions are also shown to agree well with previous experimental findings.

Bcc and Fcc transition metals and alloys: a central role for the Jahn-Teller effect in explaining their ideal and distorted structures.

PubMed

Lee, Stephen; Hoffmann, Roald

2002-05-01

Transition metal elements, alloys, and intermetallic compounds often adopt the body centered cubic (bcc) and face centered cubic (fcc) structures. By comparing quantitative density functional with qualitative tight-binding calculations, we analyze the electronic factors which make the bcc and fcc structures energetically favorable. To do so, we develop a tight-binding function, DeltaE(star), a function that measures the energetic effects of transferring electrons within wave vector stars. This function allows one to connect distortions in solids to the Jahn-Teller effect in molecules and to provide an orbital perspective on structure determining deformations in alloys. We illustrate its use by considering first a two-dimensional square net. We then turn to three-dimensional fcc and bcc structures, and distortions of these. Using DeltaE(star), we rationalize the differences in energy of these structures. We are able to deduce which orbitals are responsible for instabilities in seven to nine valence electron per atom (e(-)/a) bcc systems and five and six e(-)/a fcc structures. Finally we demonstrate that these results account for the bcc and fcc type structures found in both the elements and binary intermetallic compounds of group 4 through 9 transition metal atoms. The outline of a theory of metal structure deformations based on loss of point group operation rather than translational symmetry is presented.

First principles studies of the dependence of magnetism on the crystal phase in 4d and 5d late transition metals

NASA Astrophysics Data System (ADS)

Hüger, E.; Osuch, K.

2005-03-01

We investigate the possibility of inducing ferromagnetic order in 4d and 5d late transition metals through crystal symmetry change. First principles, self-consistent density functional theory calculations, with spin-orbit coupling included, performed at 0 K show that ferromagnetism occurs in the bulk of Rh and Pd at the optimum lattice constant if Rh is in the bcc and Pd in the hcp/dhcp phase. The ferromagnetic order originates in the d-band occupancy of Rh or Pd which locates the Fermi energy at the top of the highest peak of the respective (paramagnetic) density of states induced by the bcc or hcp/dhcp structure. This peak in the density of states is caused by flat bands which lie at the surface of the respective Brillouin zone. For a bcc crystal these flat bands have the eg character and are positioned at the surface of the bcc Brillouin zone along the N-P line. The origin of the flatness of the bands was found to be the translation symmetry of the cubic lattice which causes the bands with the eg character to be narrow along the k-lines whose k-vector directions are furthest off the directions to which the orbitals of the eg symmetry point. Due to the d-band occupancy of Rh these flat bands lie in the paramagnetic state at the Fermi energy, whereas in the ferromagnetic state they exhibit the largest energetic split. This indicates that a smaller degree of orbital overlap narrows electronic bands enhancing the tendency of the system for ferromagnetic band split. For the hcp/dhcp structure the states contributing to the high density of para-magnetic states at the Fermi level of Pd lie in the vicinity of the M-L line of the hcp Brillouin zone boundary, which possesses a high number of symmetry (M and L) points. Moreover, the M-L line is aligned with the stacking sequence direction ([0001]) which is furthest off the densest-packed atomic chain direction of an hcp-crystal and, consequently, the weakest-bond direction in the crystal. This makes the narrow bands along the M-L line flat. The instability of the bcc and the meta-stability of the hcp crystal phase modifications for metals with native close-packed crystal structures is subsequently analysed in order to find whether they can be grown as films on suitable substrates.

Accelerated Exploration of Multi-principal Element Alloys for Structural Applications (Postprint)

DTIC Science & Technology

2015-04-27

SS phases (BCC, HCP and FCC), three silicide phases (M5Si3, M5Si4 and M3Si3), an ordered B2 phase, and two Laves phases (C14 and C15). In total, 453...alloys containing silicide phases (M5Si3, M5Si4, and M3Si2) is probably due to very negative, often below 50 kJ/mol [51 53] enthalpies of formation of...The majority of equiatomic alloys containing two or more phases are (SSþ IM) alloys.5. BCC, HCP and FCC SS phases, three silicide phases (M5Si3, M5Si4

Formation of Ultrafine Metal Particles by Gas-Evaporation VI. Bcc Metals, Fe, V, Nb, Ta, Cr, Mo and W

NASA Astrophysics Data System (ADS)

Saito, Yahachi; Mihama, Kazuhiro; Uyeda, Ryozi

1980-09-01

The crystal structures and habits of bcc metal particles have been investigated systematically by electron microscopy. The habits for the bcc structure are rhombic dodecahedra truncated by six {100} faces with various degrees of truncation from 0 to 100%. The truncation degree for Fe and V particles grown in the intermediate zone of a metal smoke is in good agreement with that for the Wulff polyhedron expected from the surface energies calculated for {110} and {100} faces. Particles of Cr, Mo and W have the A-15 type structure besides the ordinary bcc structure. The present results support the hypothesis that the A-15 type structure is stable when the particle size is small. The habits for the A-15 type structure are rhombic dodecahedra (Cr), {211} icositetrahedra (Cr and Mo) and rounded cubes (Mo and W).

Observation of a New High-Pressure Solid Phase in Dynamically Compressed Aluminum

NASA Astrophysics Data System (ADS)

Polsin, D. N.

2017-10-01

Aluminum is ideal for testing theoretical first-principles calculations because of the relative simplicity of its atomic structure. Density functional theory (DFT) calculations predict that Al transforms from an ambient-pressure, face-centered-cubic (fcc) crystal to the hexagonal close-packed (hcp) and body-centered-cubic (bcc) structures as it is compressed. Laser-driven experiments performed at the University of Rochester's Laboratory for Laser Energetics and the National Ignition Facility (NIF) ramp compressed Al samples to pressures up to 540 GPa without melting. Nanosecond in-situ x-ray diffraction was used to directly measure the crystal structure at pressures where the solid-solid phase transformations of Al are predicted to occur. Laser velocimetry provided the pressure in the Al. Our results show clear evidence of the fcc-hcp and hpc-bcc transformations at 216 +/- 9 GPa and 321 +/- 12 GPa, respectively. This is the first experimental in-situ observation of the bcc phase in compressed Al and a confirmation of the fcc-hcp transition previously observed under static compression at 217 GPa. The observations indicate these solid-solid phase transitions occur on the order of tens of nanoseconds time scales. In the fcc-hcp transition we find the original texture of the sample is preserved; however, the hcp-bcc transition diminishes that texture producing a structure that is more polycrystalline. The importance of this dynamic is discussed. The NIF results are the first demonstration of x-ray diffraction measurements at two different pressures in a single laser shot. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

Economic constraints - the growing challenge for Western breast cancer centers.

PubMed

Seidel, Rene P; Lux, Michael P; Hoellthaler, Josef; Beckmann, Matthias W; Voigt, Wieland

2013-03-01

Breast cancer care in Western countries has reached a considerable level of quality and standardization, which has contributed to the decline in breast cancer mortality. Certified Breast Cancer Centers (BCC) represent an important element of this development. Related to changes in reimbursement and growing costs, BCC face economic constraints which ultimately could endanger the achievements of the past. Thus, BCC have to optimize their care strategies from an economic perspective, particularly by increasing efficiency but also by adapting their service portfolio. This could result in competitive advantages and additional revenue by increasing case numbers and extra charges to patients. Furthermore, an intensification of collaboration with the outpatient sector resulting in an integrated and managed 'trans-sectoral' care approach which could allow to shift unprofitable procedures to the outpatient sector - in the sense of a win-win situation for both sectors and without loss of care quality - seems reasonable. Structured and specialized consulting approaches can further be a lever to fulfill economic requirements in order to avoid cuts in medical care quality for the sake of a balanced budget. In this review, economic constraints of BCC with a focus on the German healthcare system and potential approaches to ameliorate these financial burdens are being discussed.

The annealing temperature dependences of microstructures and magnetic properties in electro-chemical deposited CoNiFe thin films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suharyadi, Edi, E-mail: esuharyadi@ugm.ac.id; Riyanto, Agus; Abraha, Kamsul

2016-04-19

CoNiFe thin films with various compositions had been successfully fabricated using electro-chemical deposition method. The crystal structure of Co{sub 65}Ni{sub 15}Fe{sub 20}, Co{sub 62}Ni{sub 15}Fe{sub 23}, and Co{sub 55}Ni{sub 15}Fe{sub 30} thin films was fcc, bcc-fcc mix, and bcc, respectively. The difference crystal structure results the difference in magnetic properties. The saturation magnetic flux density (Bs) of Co{sub 65}Ni{sub 15}Fe{sub 20}, Co{sub 62}Ni{sub 15}Fe{sub 23}, and Co{sub 55}Ni{sub 15}Fe{sub 30} thin films was 1.89 T, 1.93 T, and 2.05 T, respectively. An optimal annealing temperature was determined for controlling the microstructure and magnetic properties of CoNiFe thin films. Depending onmore » annealing temperature, the ratio of bcc and fcc structure varied without changing the film composition. By annealing at temperature of T ≥ 350°C, the intensity ratio of X-ray diffraction peaks for bcc(110) to fcc(111) increased. The increase of phase ratio of bcc(110) to fcc(111) caused the increase of Bs, from 1.89 T to 1.95 T. Coercivity (Hc) also increased after annealing, from 2.6 Oe to 18.6 Oe for fcc phase thin films, from 2.0 Oe to 12.0 Oe for fcc-bcc mix phase thin films, and 7.8 Oe to 8 Oe for bcc phase thin films. The changing crystal structures during annealing process indicated that the thermal treatment at high temperature cause the changing crystallinity and atomic displacement. The TEM bright-field images with corresponding selected-area electron diffraction (SAED) patterns showed that there are strongly effects of thermal annealing on the size of fcc and bcc phase crystalline grain as described by size of individual spot and discontinuous rings. The size of crystalline grains increased by thermal annealing. The evolution of bcc and fcc structures of CoNiFe during annealing is though to be responsible for the change of magnetic properties.« less

BDA: A novel method for identifying defects in body-centered cubic crystals.

PubMed

Möller, Johannes J; Bitzek, Erik

2016-01-01

The accurate and fast identification of crystallographic defects plays a key role for the analysis of atomistic simulation output data. For face-centered cubic (fcc) metals, most existing structure analysis tools allow for the direct distinction of common defects, such as stacking faults or certain low-index surfaces. For body-centered cubic (bcc) metals, on the other hand, a robust way to identify such defects is currently not easily available. We therefore introduce a new method for analyzing atomistic configurations of bcc metals, the BCC Defect Analysis (BDA). It uses existing structure analysis algorithms and combines their results to uniquely distinguish between typical defects in bcc metals. In essence, the BDA method offers the following features:•Identification of typical defect structures in bcc metals.•Reduction of erroneously identified defects by iterative comparison to the defects in the atom's neighborhood.•Availability as ready-to-use Python script for the widespread visualization tool OVITO [http://ovito.org].

Dependence of the third-order coefficients in Landau free energies for bcc --> fcc structural transition on hydrogen concentration in zirconium hydrides

NASA Astrophysics Data System (ADS)

Ashida, Yuh; Yamamoto, Masahiro; Naito, Shizuo; Mabuchi, Mahito; Hashino, Tomoyasu

1997-08-01

Young's modulus E and the modulus of rigidity G of zirconium hydrides ZrHx(0.9⩽x⩽1.65) at 941 and 1001 K have been obtained as a function of hydrogen concentration c by measuring resonance frequencies for bending and torsion vibrations of a polycrystalline wire. As c increases, observed E and G increase in the bcc β phase, slightly increase linearly in the β+δ phase, and then decrease in the fcc δ phase. On the basis of a phenomenological free energy in terms of strain components taking account of space group symmetry, two types of Landau expansion of the free energies for the β phase in terms of the strain components which play an important role in the structural phase transition between the β and the δ phases are examined. The observed E and G are assumed to be the same as the second-order coefficients of the free energy for the Bain distortions, which occur at the structural phase transition. The dependence of the third-order coefficients on c permits the expanded free energies to describe the fact that the β phase is more stable than the δ phase at low c.

Long-range empirical potential model: extension to hexagonal close-packed metals.

PubMed

Dai, Y; Li, J H; Liu, B X

2009-09-23

An n-body potential is developed and satisfactorily applied to hcp metals, Co, Hf, Mg, Re, Ti, and Zr, in the form of long-range empirical potential. The potential can well reproduce the lattice constants, c/a ratios, cohesive energies, and the bulk modulus for their stable structures (hcp) and metastable structures (bcc or fcc). Meanwhile, the potential can correctly predict the order of structural stability and distinguish the energy differences between their stable hcp structure and other structures. The energies and forces derived by the potential can smoothly go to zero at cutoff radius, thus completely avoiding the unphysical behaviors in the simulations. The developed potential is applied to study the vacancy, surface fault, stacking fault and self-interstitial atom in the hcp metals. The calculated formation energies of vacancy and divacancy and activation energies of self-diffusion by vacancies are in good agreement with the values in experiments and in other works. The calculated surface energies and stacking fault energies are also consistent with the experimental data and those obtained in other theoretical works. The calculated formation energies generally agree with the results in other works, although the stable configurations of self-interstitial atoms predicted in this work somewhat contrast with those predicted by other methods. The proposed potential is shown to be relevant for describing the interaction of bcc, fcc and hcp metal systems, bringing great convenience for researchers in constructing potentials for metal systems constituted by any combination of bcc, fcc and hcp metals.

Ordering Transformations in High-Entropy Alloys

NASA Astrophysics Data System (ADS)

Singh, Prashant; Johnson, Duane D.

The high-temperature disordered phase of multi-component alloys, including high-entropy alloys (HEA), generally must experience segregation or else passes through partially-ordered phases to reach the low-temperature, fully-ordered phase. Our first-principles KKR-CPA-based atomic short-range ordering (SRO) calculations (analyzed as concentration-waves) reveal the competing partially and fully ordered phases in HEA, and these phases can be then directly assessed from KKR-CPA results in larger unit cells [Phys. Rev. B 91, 224204 (2015)]. For AlxCrFeNiTi0.25, Liu et al. [J Alloys Compd 619, 610 (2015)] experimentally find FCC+BCC coexistence that changes to BCC with increasing Al (x from 0-to-1), which then exhibits a partially-ordered B2 at low temperatures. CALPHAD (Calculation of Phase Diagrams) predicts a region with L21+B2 coexistence. From KKR-CPA calculations, we find crossover versus Al from FCC+BCC coexistence to BCC, as observed, and regions for partially-order B2+L21 coexistence, as suggest by CALPHAD. Our combined first-principles KKR-CPA method provides a powerful approach in predicting SRO and completing long-range order in HEA and other complex alloys. Supported by the U.S. DOE, Office of Science, Basic Energy Sciences, Materials Science and Engineering Division. Work was performed at Ames Laboratory, which is operated by Iowa State University for the U.S. DOE under Contract #DE-AC02-07CH11358.

Crystal nucleation and metastable bcc phase in charged colloids: A molecular dynamics study

NASA Astrophysics Data System (ADS)

Ji, Xinqiang; Sun, Zhiwei; Ouyang, Wenze; Xu, Shenghua

2018-05-01

The dynamic process of homogenous nucleation in charged colloids is investigated by brute-force molecular dynamics simulation. To check if the liquid-solid transition will pass through metastable bcc, simulations are performed at the state points that definitely lie in the phase region of thermodynamically stable fcc. The simulation results confirm that, in all of these cases, the preordered precursors, acting as the seeds of nucleation, always have predominant bcc symmetry consistent with Ostwald's step rule and the Alexander-McTague mechanism. However, the polymorph selection is not straightforward because the crystal structures formed are not often determined by the symmetry of intermediate precursors but have different characters under different state points. The region of the state point where bcc crystal structures of large enough size are formed during crystallization is narrow, which gives a reasonable explanation as to why the metastable bcc phase in charged colloidal suspensions is rarely detected in macroscopic experiments.

Large moments in bcc FexCoyMnz ternary alloy thin films

NASA Astrophysics Data System (ADS)

Snow, R. J.; Bhatkar, H.; N'Diaye, A. T.; Arenholz, E.; Idzerda, Y. U.

2018-02-01

The elemental magnetic moments and the average atomic moment of 10-20 nm thick single crystal bcc (bct) FexCoyMnz films deposited on MgO(001) have been determined as a function of a broad range of compositions. Thin film epitaxy stabilized the bcc structure for 80% of the available ternary compositional space compared to only a 23% stability region for the bulk. The films that display ferromagnetism represent 60% of the available compositional possibilities compared to 25% for the bulk. A maximum average atomic moment of 3.25 ± 0.3 μB/atom was observed for a bcc Fe9Co62Mn29 film (well above the limit of the Slater-Pauling binary alloy curve of 2.45 μB/atom). The FexCoyMnz ternary alloys that exhibit high moments can only be synthesized as ultrathin films since the bcc structure is not stable in the bulk for those compositions.

Pressure-induced structural phase transformation and superconducting properties of titanium mononitride

NASA Astrophysics Data System (ADS)

Li, Qian; Guo, Yanan; Zhang, Miao; Ge, Xinlei

2018-03-01

In this work, we have systematically performed the first-principles structure search on titanium mononitride (TiN) within Crystal Structure AnaLYsis by Particle Swarm Optimization (CALYPSO) methodology at high pressures. Here, we have confirmed a phase transition from cubic rock-salt (fcc) phase to CsCl (bcc) phase of TiN at ∼348 GPa. Further simulations reveal that the bcc phase is dynamically stable, and could be synthesized experimentally in principle. The calculated elastic anisotropy decreases with the phase transformation from fcc to bcc structure under high pressures, and the material changes from ductile to brittle simultaneously. Moreover, we found that both structures are superconductive with the superconducting critical temperature of 2-12 K.

Robust demarcation of basal cell carcinoma by dependent component analysis-based segmentation of multi-spectral fluorescence images.

PubMed

Kopriva, Ivica; Persin, Antun; Puizina-Ivić, Neira; Mirić, Lina

2010-07-02

This study was designed to demonstrate robust performance of the novel dependent component analysis (DCA)-based approach to demarcation of the basal cell carcinoma (BCC) through unsupervised decomposition of the red-green-blue (RGB) fluorescent image of the BCC. Robustness to intensity fluctuation is due to the scale invariance property of DCA algorithms, which exploit spectral and spatial diversities between the BCC and the surrounding tissue. Used filtering-based DCA approach represents an extension of the independent component analysis (ICA) and is necessary in order to account for statistical dependence that is induced by spectral similarity between the BCC and surrounding tissue. This generates weak edges what represents a challenge for other segmentation methods as well. By comparative performance analysis with state-of-the-art image segmentation methods such as active contours (level set), K-means clustering, non-negative matrix factorization, ICA and ratio imaging we experimentally demonstrate good performance of DCA-based BCC demarcation in two demanding scenarios where intensity of the fluorescent image has been varied almost two orders of magnitude. Copyright 2010 Elsevier B.V. All rights reserved.

Economic Constraints – the Growing Challenge for Western Breast Cancer Centers

PubMed Central

Seidel, Rene P.; Lux, Michael P.; Hoellthaler, Josef; Beckmann, Matthias W.; Voigt, Wieland

2013-01-01

Summary Breast cancer care in Western countries has reached a considerable level of quality and standardization, which has contributed to the decline in breast cancer mortality. Certified Breast Cancer Centers (BCC) represent an important element of this development. Related to changes in reimbursement and growing costs, BCC face economic constraints which ultimately could endanger the achievements of the past. Thus, BCC have to optimize their care strategies from an economic perspective, particularly by increasing efficiency but also by adapting their service portfolio. This could result in competitive advantages and additional revenue by increasing case numbers and extra charges to patients. Furthermore, an intensification of collaboration with the outpatient sector resulting in an integrated and managed ‘trans-sectoral’ care approach which could allow to shift unprofitable procedures to the outpatient sector – in the sense of a win-win situation for both sectors and without loss of care quality – seems reasonable. Structured and specialized consulting approaches can further be a lever to fulfill economic requirements in order to avoid cuts in medical care quality for the sake of a balanced budget. In this review, economic constraints of BCC with a focus on the German healthcare system and potential approaches to ameliorate these financial burdens are being discussed. PMID:24715842

Possible metastable rhombohedral states of the bcc transition metals

NASA Astrophysics Data System (ADS)

Mehl, Michael; Finkenstadt, Daniel

2007-03-01

The energy E(c/a) for a bcc element stretched along its [001] axis (the Bain path) has a minimum at c/a = 1, a maximum at c/a = √2, and an elastically unstable local minimum at c/a > √2. A rhombohedral strain is an alternative method of connecting the bcc and fcc structures. The primitive lattice keeps R3m symmetry, with the angle α changing from 109.4^o (bcc), to 90^o (simple cubic), to 60^o (fcc). We studied this path for the non-magnetic bcc transition metals (V, Nb, Mo, Ta, and W) using both a full-potential LAPW and PAW VASP. Except for Ta, the energy E(α) has a local maximum at α=60^o, with local minima near 55^o and 70^o, the later having lower energy. We studied the elastic stability of the 70^o minimum structure. Only W is elastically stable in this structure, with the smallest eigenvalue of the elastic tensor at 4 GPa, while the other three elements are unstable. We discuss the possibility that Tungsten is actually metastable in this structure. We also consider the possible epitaxial growth of this structure. M. J. Mehl, A. Aguayo, L. L. Boyer, and R. De Coss, Phys. Rev. B 70, 014105 (2004).

Structural short-range order of the β-Ti phase in bulk Ti-Fe-(Sn) nanoeutectic composites

NASA Astrophysics Data System (ADS)

Das, J.; Eckert, J.; Theissmann, R.

2006-12-01

The authors report lattice distortion and "ω-like" structural short-range order (SRO) of the β-Ti phase in a Ti-Fe-(Sn) bulk nanoeutectic composite prepared by slow cooling from the melt. The nanoeuetctic phases are chemically homogeneous, but the addition of Sn releases the local lattice strain, modifies the structural SRO, and prevents the formation of stacking faults in the body centered cubic (bcc) β-Ti phase resulting in improved plastic deformability. The elastic properties and the structural SRO of the β-Ti phase are proposed to be important parameters for developing advanced high strength, ductile Ti-base nanocomposite alloys.

Discrimination between basal cell carcinoma and hair follicles in skin tissue sections by Raman micro-spectroscopy

NASA Astrophysics Data System (ADS)

Larraona-Puy, M.; Ghita, A.; Zoladek, A.; Perkins, W.; Varma, S.; Leach, I. H.; Koloydenko, A. A.; Williams, H.; Notingher, I.

2011-05-01

Skin cancer is the most common human malignancy and basal cell carcinoma (BCC) represents approximately 80% of the non-melanoma cases. Current methods of treatment require histopathological evaluation of the tissues by qualified personnel. However, this method is subjective and in some cases BCC can be confused with other structures in healthy skin, including hair follicles. In this preliminary study, we investigated the potential of Raman micro-spectroscopy (RMS) to discriminate between hair follicles and BCC in skin tissue sections excised during Mohs micrographic surgery (MMS). Imaging and diagnosis of skin sections was automatically generated using ' a priori'-built spectral model based on LDA. This model had 90 ± 9% sensitivity and 85 ± 9% specificity for discrimination of BCC from dermis and epidermis. The model used selected Raman bands corresponding to the largest spectral differences between the Raman spectra of BCC and the normal skin regions, associated mainly with nucleic acids and collagen type I. Raman spectra corresponding to the epidermis regions of the hair follicles were found to be closer to those of healthy epidermis rather than BCC. Comparison between Raman spectral images and the gold standard haematoxylin and eosin (H&E) histopathology diagnosis showed good agreement. Some hair follicle regions were misclassified as BCC; regions corresponded mainly to the outermost layer of hair follicle (basal cells) which are expected to have higher nucleic acid concentration. This preliminary study shows the ability of RMS to distinguish between BCC and other tissue structures associated to healthy skin which can be confused with BCC due to their similar morphology.

Structural Transitions in Elemental Tin at Ultra High Pressures up to 230 GPa

NASA Astrophysics Data System (ADS)

Gavriliuk, A. G.; Troyan, I. A.; Ivanova, A. G.; Aksenov, S. N.; Starchikov, S. S.; Lyubutin, I. S.; Morgenroth, W.; Glazyrin, K. V.; Mezouar, M.

2017-12-01

The crystal structure of elemental Sn was investigated by synchrotron X-ray diffraction at ultra high pressures up to ˜230 GPa creating in diamond anvil cells. Above 70 GPa, a pure bcc structure of Sn was observed, which is stable up to 160GPa, until an occurrence of the hcp phase was revealed. At the onset of the bcc- hcp transition at pressure of about 160GPa, the drop of the unit cell volume is about 1%. A mixture of the bcc- hcp states was observed at least up to 230GPa, and it seems that this state could exist even up to higher pressures. The fractions of the bcc and hcp phases were evaluated in the pressure range of the phase coexistence 160-230 GPa. The difference between static and dynamic compression and its effect on the V- P phase diagram of Sn are discussed.

Grain boundary phases in bcc metals

DOE PAGES

Frolov, T.; Setyawan, W.; Kurtz, R. J.; ...

2018-01-01

Evolutionary grand-canonical search predicts novel grain boundary structures and multiple grain boundary phases in elemental body-centered cubic (bcc) metals represented by tungsten, tantalum and molybdenum.

Elemental moment variation of bcc FexMn1-x on MgO(001)

NASA Astrophysics Data System (ADS)

Bhatkar, H.; Snow, R. J.; Arenholz, E.; Idzerda, Y. U.

2017-02-01

We report the growth, structural characterization, and electronic structure evolution of epitaxially grown bcc FexMn1-x on MgO(001). It is observed that the 20 nm thick FexMn1-x alloy films remained bcc from 0.65≤x≤1, much beyond the bulk stability range of 0.88≤x≤1. X-ray absorption spectroscopy and X-ray magnetic circular dichroism show that both the Fe and Mn L3 binding energies slightly increase with Mn incorporation and that the elemental moment of Fe in the 20 nm crystalline bcc alloy film remain nearly constant, then shows a dramatic collapse near x 0.84. The Mn MCD intensity is found to be small at all compositions that exhibit ferromagnetism

Metastable bcc phase formation in 3d ferromagnetic transition metal thin films sputter-deposited on GaAs(100) substrates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Minakawa, Shigeyuki, E-mail: s-minakawa@futamoto.elect.chuo-u.ac.jp; Ohtake, Mitsuru; Futamoto, Masaaki

2015-05-07

Co{sub 100−x}Fe{sub x} and Ni{sub 100−y}Fe{sub y} (at. %, x = 0–30, y = 0–60) films of 10 nm thickness are prepared on GaAs(100) substrates at room temperature by using a radio-frequency magnetron sputtering system. The detailed growth behavior is investigated by in-situ reflection high-energy electron diffraction. (100)-oriented Co and Ni single-crystals with metastable bcc structure are formed in the early stage of film growth, where the metastable structure is stabilized through hetero-epitaxial growth. With increasing the thickness up to 2 nm, the Co and the Ni films start to transform into more stable hcp and fcc structures through atomic displacements parallel to bcc(110) slide planes,more » respectively. The stability of bcc phase is improved by adding a small volume of Fe atoms into a Co film. The critical thickness of bcc phase formation is thicker than 10 nm for Co{sub 100−x}Fe{sub x} films with x ≥ 10. On the contrary, the stability of bcc phase for Ni-Fe system is less than that for Co-Fe system. The critical thicknesses for Ni{sub 100−y}Fe{sub y} films with y = 20, 40, and 60 are 1, 3, and 5 nm, respectively. The Co{sub 100−x}Fe{sub x} single-crystal films with metastable bcc structure formed on GaAs(100) substrates show in-plane uniaxial magnetic anisotropies with the easy direction along GaAs[011], similar to the case of Fe film epitaxially grown on GaAs(100) substrate. A Co{sub 100−x}Fe{sub x} film with higher Fe content shows a higher saturation magnetization and a lower coercivity.« less

Ab-initio study of high temperature lattice dynamics of BCC zirconium (β-Zr) and uranium (γ-U)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghosh, Partha S., E-mail: parthasarathi13@gmail.com; Arya, A., E-mail: parthasarathi13@gmail.com; Dey, G. K., E-mail: parthasarathi13@gmail.com

2014-04-24

Using self consistent ab-initio lattice dynamics calculations, we show that bcc structures of Zr and U phases become stable at high temperature by phonon-phonon interactions. The calculated temperature dependent phonon dispersion curve (PDC) of β-Zr match excellently with experimental PDC. But the calculated PDC for γ-U shows negative phonon frequencies even at solid to liquid transition temperature. We show that this discrepancy is due to an overestimation of instability depth of bcc U phase which is removed by incorporation of spin-orbit coupling in the electronic structure calculations.

The BCC/B2 morphologies in Al xNiCoFeCr high-entropy alloys

DOE PAGES

Ma, Yue; Jiang, Beibei; Li, Chunling; ...

2017-02-15

Here, the present work primarily investigates the morphological evolution of the body-centered-cubic (BCC)/B2 phases in Al xNiCoFeCr high-entropy alloys (HEAs) with increasing Al content. It is found that the BCC/B2 coherent morphology is closely related to the lattice misfit between these two phases, which is sensitive to Al. There are two types of microscopic BCC/B2 morphologies in this HEA series: one is the weave-like morphology induced by the spinodal decomposition, and the other is the microstructure of a spherical disordered BCC precipitation on the ordered B2 matrix that appears in HEAs with a much higher Al content. The mechanical properties,more » including the compressive yielding strength and microhardness of the Al xNiCoFeCr HEAs, are also discussed in light of the concept of the valence electron concentration (VEC).« less

Molecular dynamics study of melting and fcc-bcc transitions in Xe.

PubMed

Belonoshko, A B; Ahuja, R; Johansson, B

2001-10-15

We have investigated the phase diagram of Xe over a wide pressure-temperature range by molecular dynamics. The calculated melting curve is in good agreement with earlier experimental data. At a pressure of around 25 GPa and a temperature of about 2700 K we find a triple fcc-bcc liquid point. The calculated fcc-bcc boundary is in nice agreement with the experimental points, which, however, were interpreted as melting. This finding suggests that the transition from close-packed to bcc structure might be more common at high pressure and high temperature than was previously anticipated.

Ordering-separation phase transitions in a Co3V alloy

NASA Astrophysics Data System (ADS)

Ustinovshchikov, Yu. I.

2017-01-01

The microstructure of the Co3V alloy formed by heat treatment at various temperatures is studied by transmission electron microscopy. Two ordering-separation phase transitions are revealed at temperatures of 400-450 and 800°C. At the high-temperature phase separation, the microstructure consists of bcc vanadium particles and an fcc solid solution; at the low-temperature phase separation, the microstructure is cellular. In the ordering range, the microstructure consists of chemical compound Co3V particles chaotically arranged in the solid solution. The structure of the Co3V alloy is shown not to correspond to the structures indicated in the Co-V phase diagram at any temperatures.

The obligate respiratory supercomplex from Actinobacteria.

PubMed

Kao, Wei-Chun; Kleinschroth, Thomas; Nitschke, Wolfgang; Baymann, Frauke; Neehaul, Yashvin; Hellwig, Petra; Richers, Sebastian; Vonck, Janet; Bott, Michael; Hunte, Carola

2016-10-01

Actinobacteria are closely linked to human life as industrial producers of bioactive molecules and as human pathogens. Respiratory cytochrome bcc complex and cytochrome aa3 oxidase are key components of their aerobic energy metabolism. They form a supercomplex in the actinobacterial species Corynebacterium glutamicum. With comprehensive bioinformatics and phylogenetic analysis we show that genes for cyt bcc-aa3 supercomplex are characteristic for Actinobacteria (Actinobacteria and Acidimicrobiia, except the anaerobic orders Actinomycetales and Bifidobacteriales). An obligatory supercomplex is likely, due to the lack of genes encoding alternative electron transfer partners such as mono-heme cyt c. Instead, subunit QcrC of bcc complex, here classified as short di-heme cyt c, will provide the exclusive electron transfer link between the complexes as in C. glutamicum. Purified to high homogeneity, the C. glutamicum bcc-aa3 supercomplex contained all subunits and cofactors as analyzed by SDS-PAGE, BN-PAGE, absorption and EPR spectroscopy. Highly uniform supercomplex particles in electron microscopy analysis support a distinct structural composition. The supercomplex possesses a dimeric stoichiometry with a ratio of a-type, b-type and c-type hemes close to 1:1:1. Redox titrations revealed a low potential bcc complex (Em(ISP)=+160mV, Em(bL)=-291mV, Em(bH)=-163mV, Em(cc)=+100mV) fined-tuned for oxidation of menaquinol and a mixed potential aa3 oxidase (Em(CuA)=+150mV, Em(a/a3)=+143/+317mV) mediating between low and high redox potential to accomplish dioxygen reduction. The generated molecular model supports a stable assembled supercomplex with defined architecture which permits energetically efficient coupling of menaquinol oxidation and dioxygen reduction in one supramolecular entity. Copyright © 2016 Elsevier B.V. All rights reserved.

Morphologic features of basal cell carcinoma using the en-face mode in frequency domain optical coherence tomography.

PubMed

von Braunmühl, T; Hartmann, D; Tietze, J K; Cekovic, D; Kunte, C; Ruzicka, T; Berking, C; Sattler, E C

2016-11-01

Optical coherence tomography (OCT) has become a valuable non-invasive tool in the in vivo diagnosis of non-melanoma skin cancer, especially of basal cell carcinoma (BCC). Due to an updated software-supported algorithm, a new en-face mode - similar to the horizontal en-face mode in high-definition OCT and reflectance confocal microscopy - surface-parallel imaging is possible which, in combination with the established slice mode of frequency domain (FD-)OCT, may offer additional information in the diagnosis of BCC. To define characteristic morphologic features of BCC using the new en-face mode in addition to the conventional cross-sectional imaging mode for three-dimensional imaging of BCC in FD-OCT. A total of 33 BCC were examined preoperatively by imaging in en-face mode as well as cross-sectional mode in FD-OCT. Characteristic features were evaluated and correlated with histopathology findings. Features established in the cross-sectional imaging mode as well as additional features were present in the en-face mode of FD-OCT: lobulated structures (100%), dark peritumoral rim (75%), bright peritumoral stroma (96%), branching vessels (90%), compressed fibrous bundles between lobulated nests ('star shaped') (78%), and intranodular small bright dots (51%). These features were also evaluated according to the histopathological subtype. In the en-face mode, the lobulated structures with compressed fibrous bundles of the BCC were more distinct than in the slice mode. FD-OCT with a new depiction for horizontal and vertical imaging modes offers additional information in the diagnosis of BCC, especially in nodular BCC, and enhances the possibility of the evaluation of morphologic tumour features. © 2016 European Academy of Dermatology and Venereology.

Computational modeling of high-entropy alloys: Structures, thermodynamics and elasticity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Michael C.; Gao, Pan; Hawk, Jeffrey A.

This study provides a short review on computational modeling on the formation, thermodynamics, and elasticity of single-phase high-entropy alloys (HEAs). Hundreds of predicted single-phase HEAs were re-examined using various empirical thermo-physical parameters. Potential BCC HEAs (CrMoNbTaTiVW, CrMoNbReTaTiVW, and CrFeMoNbReRuTaVW) were suggested based on CALPHAD modeling. The calculated vibrational entropies of mixing are positive for FCC CoCrFeNi, negative for BCC MoNbTaW, and near-zero for HCP CoOsReRu. The total entropies of mixing were observed to trend in descending order: CoCrFeNi > CoOsReRu > MoNbTaW. Calculated lattice parameters agree extremely well with averaged values estimated from the rule of mixtures (ROM) if themore » same crystal structure is used for the elements and the alloy. The deviation in the calculated elastic properties from ROM for select alloys is small but is susceptible to the choice used for the structures of pure components.« less

Computational modeling of high-entropy alloys: Structures, thermodynamics and elasticity

DOE PAGES

Gao, Michael C.; Gao, Pan; Hawk, Jeffrey A.; ...

2017-10-12

This study provides a short review on computational modeling on the formation, thermodynamics, and elasticity of single-phase high-entropy alloys (HEAs). Hundreds of predicted single-phase HEAs were re-examined using various empirical thermo-physical parameters. Potential BCC HEAs (CrMoNbTaTiVW, CrMoNbReTaTiVW, and CrFeMoNbReRuTaVW) were suggested based on CALPHAD modeling. The calculated vibrational entropies of mixing are positive for FCC CoCrFeNi, negative for BCC MoNbTaW, and near-zero for HCP CoOsReRu. The total entropies of mixing were observed to trend in descending order: CoCrFeNi > CoOsReRu > MoNbTaW. Calculated lattice parameters agree extremely well with averaged values estimated from the rule of mixtures (ROM) if themore » same crystal structure is used for the elements and the alloy. The deviation in the calculated elastic properties from ROM for select alloys is small but is susceptible to the choice used for the structures of pure components.« less

Strong, Ductile, and Thermally Stable bcc-Mg Nanolaminates.

PubMed

Pathak, Siddhartha; Velisavljevic, Nenad; Baldwin, J Kevin; Jain, Manish; Zheng, Shijian; Mara, Nathan A; Beyerlein, Irene J

2017-08-15

Magnesium has attracted attention worldwide because it is the lightest structural metal. However, a high strength-to-weight ratio remains its only attribute, since an intrinsic lack of strength, ductility and low melting temperature severely restricts practical applications of Mg. Through interface strains, the crystal structure of Mg can be transformed and stabilized from a simple hexagonal (hexagonal close packed hcp) to body center cubic (bcc) crystal structure at ambient pressures. We demonstrate that when introduced into a nanocomposite bcc Mg is far more ductile, 50% stronger, and retains its strength after extended exposure to 200 C, which is 0.5 times its homologous temperature. These findings reveal an alternative solution to obtaining lightweight metals critically needed for future energy efficiency and fuel savings.

Transformation of BCC and B2 High Temperature Phases to HCP and Orthorhombic Structures in the Ti-Al-Nb System. Part II: Experimental TEM Study of Microstructures

PubMed Central

Bendersky, L. A.; Boettinger, W. J.

1993-01-01

Possible transformation paths that involve no long range diffusion and their corresponding microstructural details were predicted by Bendersky, Roytburd, and Boettinger [J. Res. Natl. Inst. Stand. Technol. 98, 561 (1993)] for Ti-Al-Nb alloys cooled from the high temperature BCC/B2 phase field into close-packed orthorhombic or hexagonal phase fields. These predictions were based on structural and symmetry relations between the known phases. In the present paper experimental TEM results show that two of the predicted transformation paths are indeed followed for different alloy compositions. For Ti-25Al-12.5Nb (at%), the path includes the formation of intermediate hexagonal phases, A3 and DO19, and subsequent formation of a metastable domain structure of the low-temperature O phase. For alloys close to Ti-25Al-25Nb (at%), the path involves an intermediate B19 structure and subsequent formation of a translational domain structure of the O phase. The path selection depends on whether B2 order forms in the high temperature cubic phase prior to transformation to the close-packed structure. The paper also analyzes the formation of a two-phase modulated microstructure during long term annealing at 700 °C. The structure forms by congruent ordering of the DO19 phase to the O phase, and then reprecipitation of the DO19 phase, possibly by a spinodal mechanism. The thermodynamics underlying the path selection and the two-phase formation are also discussed. PMID:28053488

Evaluating ex vivo fluorescence confocal microscopy images of basal cell carcinomas in Mohs excised tissue.

PubMed

Longo, C; Rajadhyaksha, M; Ragazzi, M; Nehal, K; Gardini, S; Moscarella, E; Lallas, A; Zalaudek, I; Piana, S; Argenziano, G; Pellacani, G

2014-09-01

Fluorescence confocal microscopy (FCM) is an emerging technology for rapid imaging of excised tissue, without the need for frozen- or fixed-section processing. Basal cell carcinomas (BCCs) can be detected in Mohs excisions although few studies have described the major BCC findings as seen on FCM. To describe the major BCC findings of excised tissue during Mohs surgery and to correlate them with histopathology. Freshly excised tumours and frozen-thawed discarded tissue of BCC during Mohs surgery were analysed by means of FCM. A side-by-side correlation between FCM images and histological sections was performed. The FCM features of overlying skin and adnexal structures were also described. Sixty-four BCC cases were analysed. Distinct BCC types appeared unique in terms of shape and size of tumour islands [bigger in nodular (18/25), smaller and rounded in micronodular (7/7) and tiny cords for infiltrative ones (24/30)] and for the presence of clefting, palisading and increased nucleus/cytoplasm ratio. An excellent correlation was found between FCM and histological findings (Cohen's κ statistics = 0·9). In six cases, the presence of sebaceous glands and intense stroma reaction represented possible confounders. Fluorescence confocal microscopy is a fast and new imaging technique that allows an excellent visualization of skin structures and BCC findings during Mohs surgery. © 2014 British Association of Dermatologists.

Strong, Ductile, and Thermally Stable bcc-Mg Nanolaminates

DOE PAGES

Pathak, Siddhartha; Velisavljevic, Nenad; Baldwin, Jon Kevin Scott; ...

2017-08-15

Magnesium has attracted attention worldwide because it is the lightest structural metal. However, a high strength-to-weight ratio remains its only attribute, since an intrinsic lack of strength, ductility and low melting temperature severely restricts practical applications of Mg. Through interface strains, the crystal structure of Mg can be transformed and stabilized from a simple hexagonal (hexagonal close packed hcp) to body center cubic (bcc) crystal structure at ambient pressures. Here, we demonstrate that when introduced into a nanocomposite bcc Mg is far more ductile, 50% stronger, and retains its strength after extended exposure to 200°C, which is 0.5 times itsmore » homologous temperature. These findings reveal an alternative solution to obtaining lightweight metals critically needed for future energy efficiency and fuel savings.« less

Gene Expression and Proteome Analysis as Sources of Biomarkers in Basal Cell Carcinoma

PubMed Central

Ghita, Mihaela Adriana; Voiculescu, Suzana; Rosca, Adrian E.; Moraru, Liliana; Greabu, Maria

2016-01-01

Basal cell carcinoma (BCC) is the world's leading skin cancer in terms of frequency at the moment and its incidence continues to rise each year, leading to profound negative psychosocial and economic consequences. UV exposure is the most important environmental factor in the development of BCC in genetically predisposed individuals, this being reflected by the anatomical distribution of lesions mainly on sun-exposed skin areas. Early diagnosis and prompt management are of crucial importance in order to prevent local tissue destruction and subsequent disfigurement. Although various noninvasive or minimal invasive techniques have demonstrated their utility in increasing diagnostic accuracy of BCC and progress has been made in its treatment options, recurrent, aggressive, and metastatic variants of BCC still pose significant challenge for the healthcare system. Analysis of gene expression and proteomic profiling of tumor cells and of tumoral microenvironment in various tissues strongly suggests that certain molecules involved in skin cancer pathogenic pathways might represent novel predictive and prognostic biomarkers in BCC. PMID:27578920

Ion-beam-induced magnetic transformation of CO-stabilized fcc Fe films on Cu(100)

NASA Astrophysics Data System (ADS)

Shah Zaman, Sameena; Oßmer, Hinnerk; Jonner, Jakub; Novotný, Zbyněk; Buchsbaum, Andreas; Schmid, Michael; Varga, Peter

2010-12-01

We have grown 22-ML-thick Fe films on a Cu(100) single crystal. The films were stabilized in the face-centered-cubic (fcc) γ phase by adsorption of carbon monoxide during growth, preventing the transformation to the body-centered-cubic (bcc) α phase. A structural transformation of these films from fcc to bcc can be induced by Ar+ ion irradiation. Scanning-tunneling microscopy images show the nucleation of bcc crystallites, which grow with increasing Ar+ ion dose and eventually result in complete transformation of the film to bcc. Surface magneto-optic Kerr effect measurements confirm the transformation of the Fe film from paramagnetic (fcc) to ferromagnetic (bcc) with an in-plane easy axis. The transformation can also be observed by low-energy electron diffraction. We find only very few nucleation sites of the bcc phase and argue that nucleation of the bcc phase happens under special circumstances during resolidification of the molten iron in the thermal spike after ion impact. Intermixing with the Cu substrate impedes the transformation. We also demonstrate the transformation of films coated with Au to protect them from oxidation at ambient conditions.

In vivo detection of basal cell carcinoma: comparison of a reflectance confocal microscope and a multiphoton tomograph

NASA Astrophysics Data System (ADS)

Ulrich, Martina; Klemp, Marisa; Darvin, Maxim E.; König, Karsten; Lademann, Jürgen; Meinke, Martina C.

2013-06-01

The standard diagnostic procedure for basal cell carcinoma (BCC) is invasive tissue biopsy with time-consuming histological examination. To reduce the number of biopsies, noninvasive optical methods have been developed providing high-resolution skin examination. We present direct comparison of a reflectance confocal microscope (RLSM) and a multiphoton tomograph (MPT) for BCC diagnosis. Both systems are applied to nine patients prior to surgery, and the results are analyzed, including histological results. Both systems prove suitable for detecting typical characteristics of BCC in various stages. The RLSM allows large horizontal overview images to be obtained, enabling the investigator to find the regions of interest quickly, e.g., BCC nests. Elongated cells and palisading structures are easily recognized using both methods. Due to the higher resolution, changes in nucleus diameter or cytoplasm could be visualized with the MPT. Therefore, the nucleus diameter, nucleus/cytoplasm ratio, and cell density are estimated for normal and BCC cells using the MPT. The nucleus of elongated BCC cells is significantly longer than other measured normal skin cells, whereas the cell density and nucleus/cytoplasm ratio of BCC cannot be significantly distinguished from granular cells.

Risk Factors for Basal Cell Carcinoma in Men Younger Than 40 Years: A Case-Control Study.

PubMed

Nemer, Kathleen M; Bauman, Tyler M; Boyd, Alan S

2018-05-09

Basal cell carcinoma (BCC) is the most common malignancy in the United States and is more prevalent in older populations. The aim of this study was to investigate BCC risk factors in male patients younger than 40 years. A consecutive series of male patients with pathology-proven BCC and younger than 40 years at time of diagnosis were retrospectively identified along with matched controls. Phone interviews were conducted using a structured questionnaire, and differences between patients with and without BCC were investigated. A total of 50 patients with BCC and 27 controls were included in this study. Compared with controls, patients with BCC worked outdoor jobs for longer lengths of time (43.2 vs 15.6 months; p = .04), were more likely to have a family history of skin cancer (66% vs 44%; p = .02), and were more likely to use sunscreen heavily after biopsy (p = .02). Patients with multiple BCCs (n = 20) were more likely to have a history of substantial recreational sun exposure (p = .01) than patients with solitary lesions (n = 30). The authors conclude that outdoor sun exposure in patients with underlying genetic susceptibility is the most likely mechanism of BCC formation in young male patients.

Measurement of Body-Centered-Cubic Aluminum at 475 GPa [Observation of Body-Centered-Cubic Aluminum at 475 GPa

DOE PAGES

Polsin, D. N.; Fratanduono, D. E.; Rygg, J. R.; ...

2017-10-27

Nanosecond in situ x-ray diffraction and simultaneous velocimetry measurements were used to determine the crystal structure and pressure, respectively, of ramp compressed aluminum at stress states between 111 and 475 GPa. The solid-solid Al phase transformations, fcc-hcp and hcp-bcc, are observed at 216 ± 9 GPa and 321 ± 12 GPa, respectively, with the bcc phase persisting to 475 GPa. Here, this is the first in situ observation of the high-pressure bcc phase of Al. High-pressure texture of the hcp and bcc phases suggests close-packed or nearly close-packed lattice planes remain parallel through both transformations.

Measurement of Body-Centered-Cubic Aluminum at 475 GPa [Observation of Body-Centered-Cubic Aluminum at 475 GPa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Polsin, D. N.; Fratanduono, D. E.; Rygg, J. R.

Nanosecond in situ x-ray diffraction and simultaneous velocimetry measurements were used to determine the crystal structure and pressure, respectively, of ramp compressed aluminum at stress states between 111 and 475 GPa. The solid-solid Al phase transformations, fcc-hcp and hcp-bcc, are observed at 216 ± 9 GPa and 321 ± 12 GPa, respectively, with the bcc phase persisting to 475 GPa. Here, this is the first in situ observation of the high-pressure bcc phase of Al. High-pressure texture of the hcp and bcc phases suggests close-packed or nearly close-packed lattice planes remain parallel through both transformations.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Rong; Wu, Yongquan, E-mail: yqwu@shu.edu.cn; Xiao, Junjiang

We observed homogeneous nucleation process of supercooled liquid Fe by molecular dynamics simulations. Using bond-orientational order parameters together with Voronoi polyhedron method, we characterized local structure, calculated the volume of Voronoi polyhedra of atoms and identified the structure and density fluctuations. We monitored the formation of nucleus and analyzed its inner structure. The birth and growth of the pre-nucleus and nucleus are accompanied with aggregating and disaggregating processes in the time scale of femtosecond. Only the initial solid-like clusters (ISLC), ranging from 1 to 7 atoms, pop up directly from liquid. The relation between the logarithm of number of clustersmore » and the cluster size was found to be linear for ISLCs and was observed to be parabolic for all solid-like clusters (SLC) due to aggregating and disaggregating effects. The nucleus and pre-nuclei mainly consist of body centered cubic (BCC) and hexagonal close packed atoms, while the BCC atoms tend to be located at the surface. Medium-range structure fluctuations induce the birth of ISLCs, benefit the aggregation of embryos and remarkably promote the nucleation. But density fluctuations contribute little to nucleation. The lifetime of most icosahedral-like atoms (ICO) is shorter than 0.7 ps. No obvious relationship was found between structure/density fluctuations and the appearance of ICO atoms.« less

AUTOMATIC DIRT TRAIL ANALYSIS IN DERMOSCOPY IMAGES

PubMed Central

Cheng, Beibei; Stanley, R. Joe; Stoecker, William V.; Osterwise, Christopher T.P.; Stricklin, Sherea M.; Hinton, Kristen A.; Moss, Randy H.; Oliviero, Margaret; Rabinovitz, Harold S.

2011-01-01

Basal cell carcinoma (BCC) is the most common cancer in the U.S. Dermatoscopes are devices used by physicians to facilitate the early detection of these cancers based on the identification of skin lesion structures often specific to BCCs. One new lesion structure, referred to as dirt trails, has the appearance of dark gray, brown or black dots and clods of varying sizes distributed in elongated clusters with indistinct borders, often appearing as curvilinear trails. In this research, we explore a dirt trail detection and analysis algorithm for extracting, measuring, and characterizing dirt trails based on size, distribution, and color in dermoscopic skin lesion images. These dirt trails are then used to automatically discriminate BCC from benign skin lesions. For an experimental data set of 35 BCC images with dirt trails and 79 benign lesion images, a neural network-based classifier achieved a 0.902 area under a receiver operating characteristic curve using a leave-one-out approach, demonstrating the potential of dirt trails for BCC lesion discrimination. PMID:22233099

X-ray diffraction of solid tin to 1.2 TPa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lazicki, A.; Rygg, J. R.; Coppari, F.

2015-08-12

In this study, we report direct in situ measurements of the crystal structure of tin between 0.12 and 1.2 TPa, the highest stress at which a crystal structure has ever been observed. Using angle-dispersive powder x-ray diffraction, we find that dynamically compressed Sn transforms to the body-centered-cubic (bcc) structure previously identified by ambient-temperature quasistatic-compression studies and by zero-kelvin density-functional theory predictions between 0.06 and 0.16 TPa. However, we observe no evidence for the hexagonal close-packed (hcp) phase found by those studies to be stable above 0.16 TPa. Instead, our results are consistent with bcc up to 1.2 TPa. We conjecturemore » that at high temperature bcc is stabilized relative to hcp due to differences in vibrational free energy.« less

Low-Temperature Criticality of Martensitic Transformations of Cu Nanoprecipitates in α-Fe

NASA Astrophysics Data System (ADS)

Erhart, Paul; Sadigh, Babak

2013-07-01

Nanoprecipitates form during nucleation of multiphase equilibria in phase segregating multicomponent systems. In spite of their ubiquity, their size-dependent physical chemistry, in particular, at the boundary between phases with incompatible topologies, is still rather arcane. Here, we use extensive atomistic simulations to map out the size-temperature phase diagram of Cu nanoprecipitates in α-Fe. The growing precipitates undergo martensitic transformations from the body-centered cubic (bcc) phase to multiply twinned 9R structures. At high temperatures, the transitions exhibit strong first-order character and prominent hysteresis. Upon cooling, the discontinuities become less pronounced and the transitions occur at ever smaller cluster sizes. Below 300 K, the hysteresis vanishes while the transition remains discontinuous with a finite but diminishing latent heat. This unusual size-temperature phase diagram results from the entropy generated by the soft modes of the bcc-Cu phase, which are stabilized through confinement by the α-Fe lattice.

Survey of the Status of Women. Institutional Research Report No. 7.

ERIC Educational Resources Information Center

Vlahos, Mantha

In order to determine some of the prevalent attitudes toward women at Broward Community College (BCC) in Florida, questionnaires were sent to all staff, faculty, and administrators, and to 200 students. Respondents consisted of 52.4 percent females and 47.6 percent males. The average female respondent was 30 years old, had been employed at BCC for…

75 FR 28188 - Schedule of Fees for Consular Services, Department of State and Overseas Embassies and Consulates

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-20

... compete with foreign-based enterprises in domestic and export markets. Executive Order 12866 OMB considers...). Finally, the rule increases the $13 BCC fee charged to Mexican citizen minors who apply in Mexico, and... above, for Mexican citizens under 15 years of age who apply for a BCC in Mexico, and have at least one...

Metastable phase formation in undercooled Fe-Co melts under terrestrial and parabolic flight conditions

NASA Astrophysics Data System (ADS)

Hermann, R.; Löser, W.; Lindenkreuz, H. G.; Yang-Bitterlich, W.; Mickel, Ch.; Diefenbach, A.; Schneider, S.; Dreier, W.

2007-12-01

Soft magnetic Fe-Co alloys display primary fcc phase solidification for>19,5 at% Co in conventional near-equilibrium solidification processes. Undercooled Fe-Co melt drops within the composition range of 30 to 50 at% Co have been investigated with the electromagnetic levitation technique. The solidification kinetics was measured in situ using a high-resolution Siphotodiode. Melt drops were undercooled up to 263 K below the liquidus temperature and subsequently quenched onto a chill substrate in order to characterize the solidification sequence and microstructure. The transition from stable fcc phase to metastable bcc primary phase solidification has been observed after reaching a critical undercooling level. The critical undercooling increases with rising Co content. The growth velocity drops obviously after transition to metastable bcc phase formation. Parabolic flight experiments were performed in order to study the phase selection under reduced gravity conditions. Under microgravity conditions, a much smaller critical undercooling and an increased life time of the metastable bcc phase were obtained. This result was validated with TEM investigations. The appearance of Fe-O particles gives an indirect hint for an intermediate fcc phase formation from the metastable bcc phase at elevated temperature.

Temperature dependent magnon-phonon coupling in bcc Fe from theory and experiment.

PubMed

Körmann, F; Grabowski, B; Dutta, B; Hickel, T; Mauger, L; Fultz, B; Neugebauer, J

2014-10-17

An ab initio based framework for quantitatively assessing the phonon contribution due to magnon-phonon interactions and lattice expansion is developed. The theoretical results for bcc Fe are in very good agreement with high-quality phonon frequency measurements. For some phonon branches, the magnon-phonon interaction is an order of magnitude larger than the phonon shift due to lattice expansion, demonstrating the strong impact of magnetic short-range order even significantly above the Curie temperature. The framework closes the previous simulation gap between the ferro- and paramagnetic limits.

Σ 3 (111 ) grain boundary of body-centered cubic Ti-Mo and Ti-V alloys: First-principles and model calculations

NASA Astrophysics Data System (ADS)

Yan, Jia-Yi; Ehteshami, Hossein; Korzhavyi, Pavel A.; Borgenstam, Annika

2017-07-01

The energetics and atomic structures of Σ 3 [1 1 ¯0 ] (111 ) grain boundary (GB) of body-centered cubic (bcc) Ti-Mo and Ti-V alloys are investigated using density-functional-theory calculations and virtual crystal approximation. The electron density in bcc structure and the atomic displacements and excess energy of the GB are correlated to bcc-ω phase stability. Model calculations based on pairwise interplanar interactions successfully reproduce the chemical part of GB energy. The chemical GB energy can be expressed as a sum of excess pairwise interactions between bcc (111) layers, which are obtained from Gaussian elimination of the total energies of a number of periodic structures. The energy associated with the relaxation near the GB is solved by numerical minimization using the derivatives of the excess interactions. Anharmonic interlayer interactions are necessary for obtaining accurate relaxation energy and excess GB volume from model calculations. The effect of GB on vibrational spectrum is also investigated. Segregation energies of B and Y to a substitutional site on the GB plane are calculated. Preliminary results suggest that Y tends to segregate, while B tends to antisegregate.

Freezing of soft spheres: A critical test for weighted-density-functional theories

NASA Astrophysics Data System (ADS)

Laird, Brian B.; Kroll, D. M.

1990-10-01

We study the freezing properties of systems with inverse-power and Yukawa interactions (soft spheres), using recently developed weighted-density-functional theories. We find that the modified weighted-density-functional approximation (MWDA) of Denton and Ashcroft yields results for the liquid to face-centered-cubic (fcc) structure transition that represent a significant improvement over those of earlier ``second-order'' density-functional freezing theories; however, this theory, like the earlier ones, fails to predict any liquid to body-centered-cubic (bcc) transition, even under conditions where the computer simulations indicate that this should be the equilibrium solid structure. In addition, we show that both the modified effective-liquid approximation (MELA) of Baus [J. Phys. Condens. Matter 2, 2111 (1990)] and the generalized effective-liquid approximation of Lutsko and Baus [Phys. Rev. Lett. 64, 761 (1990)], while giving excellent results for the freezing of hard spheres, fail completely to predict freezing into either fcc or bcc solid phases for soft inverse-power potentials. We also give an alternate derivation of the MWDA that makes clearer its connection to earlier theories.

A unified relation for the solid-liquid interface free energy of pure FCC, BCC, and HCP metals.

PubMed

Wilson, S R; Mendelev, M I

2016-04-14

We study correlations between the solid-liquid interface (SLI) free energy and bulk material properties (melting temperature, latent heat, and liquid structure) through the determination of SLI free energies for bcc and hcp metals from molecular dynamics (MD) simulation. Values obtained for the bcc metals in this study were compared to values predicted by the Turnbull, Laird, and Ewing relations on the basis of previously published MD simulation data. We found that of these three empirical relations, the Ewing relation better describes the MD simulation data. Moreover, whereas the original Ewing relation contains two constants for a particular crystal structure, we found that the first coefficient in the Ewing relation does not depend on crystal structure, taking a common value for all three phases, at least for the class of the systems described by embedded-atom method potentials (which are considered to provide a reasonable approximation for metals).

A unified relation for the solid-liquid interface free energy of pure FCC, BCC, and HCP metals

NASA Astrophysics Data System (ADS)

Wilson, S. R.; Mendelev, M. I.

2016-04-01

We study correlations between the solid-liquid interface (SLI) free energy and bulk material properties (melting temperature, latent heat, and liquid structure) through the determination of SLI free energies for bcc and hcp metals from molecular dynamics (MD) simulation. Values obtained for the bcc metals in this study were compared to values predicted by the Turnbull, Laird, and Ewing relations on the basis of previously published MD simulation data. We found that of these three empirical relations, the Ewing relation better describes the MD simulation data. Moreover, whereas the original Ewing relation contains two constants for a particular crystal structure, we found that the first coefficient in the Ewing relation does not depend on crystal structure, taking a common value for all three phases, at least for the class of the systems described by embedded-atom method potentials (which are considered to provide a reasonable approximation for metals).

Cubic martensite in high carbon steel

NASA Astrophysics Data System (ADS)

Chen, Yulin; Xiao, Wenlong; Jiao, Kun; Ping, Dehai; Xu, Huibin; Zhao, Xinqing; Wang, Yunzhi

2018-05-01

A distinguished structural characteristic of martensite in Fe-C steels is its tetragonality originating from carbon atoms occupying only one set of the three available octahedral interstitial sites in the body-centered-cubic (bcc) Fe lattice. Such a body-centered-tetragonal (bct) structure is believed to be thermodynamically stable because of elastic interactions between the interstitial carbon atoms. For such phase stability, however, there has been a lack of direct experimental evidence despite extensive studies of phase transformations in steels over one century. In this Rapid Communication, we report that the martensite formed in a high carbon Fe-8Ni-1.26C (wt%) steel at room temperature induced by applied stress/strain has actually a bcc rather than a bct crystal structure. This finding not only challenges the existing theories on the stability of bcc vs bct martensite in high carbon steels, but also provides insights into the mechanism for martensitic transformation in ferrous alloys.

Downregulation of the Sonic Hedgehog/Gli pathway transcriptional target Neogenin-1 is associated with basal cell carcinoma aggressiveness.

PubMed

Casas, Bárbara S; Adolphe, Christelle; Lois, Pablo; Navarrete, Nelson; Solís, Natalia; Bustamante, Eva; Gac, Patricio; Cabané, Patricio; Gallegos, Ivan; Wainwright, Brandon J; Palma, Verónica

2017-10-13

Basal Cell Carcinoma (BCC) is one of the most diagnosed cancers worldwide. It develops due to an unrestrained Sonic Hedgehog (SHH) signaling activity in basal cells of the skin. Certain subtypes of BCC are more aggressive than others, although the molecular basis of this phenomenon remains unknown. We have previously reported that Neogenin-1 (NEO1) is a downstream target gene of the SHH/GLI pathway in neural tissue. Given that SHH participates in epidermal homeostasis, here we analyzed the epidermal expression of NEO1 in order to identify whether it plays a role in adult epidermis or BCC. We describe the mRNA and protein expression profile of NEO1 and its ligands (Netrin-1 and RGMA) in human and mouse control epidermis and in a broad range of human BCCs. We identify in human BCC a significant positive correlation in the levels of NEO1 receptor, NTN-1 and RGMA ligands with respect to GLI1 , the main target gene of the canonical SHH pathway. Moreover, we show via cyclopamine inhibition of the SHH/GLI pathway of ex vivo cultures that NEO1 likely functions as a downstream target of SHH/GLI signaling in the skin. We also show how Neo1 expression decreases throughout BCC progression in the K14-Cre:Ptch1 lox/lox mouse model and that aggressive subtypes of human BCC exhibit lower levels of NEO1 than non-aggressive BCC samples. Taken together, these data suggest that NEO1 is a SHH/GLI target in epidermis. We propose that NEO1 may be important in tumor onset and is then down-regulated in advanced BCC or aggressive subtypes.

Downregulation of the Sonic Hedgehog/Gli pathway transcriptional target Neogenin-1 is associated with basal cell carcinoma aggressiveness

PubMed Central

Casas, Bárbara S.; Adolphe, Christelle; Lois, Pablo; Navarrete, Nelson; Solís, Natalia; Bustamante, Eva; Gac, Patricio; Cabané, Patricio; Gallegos, Ivan; Wainwright, Brandon J.; Palma, Verónica

2017-01-01

Basal Cell Carcinoma (BCC) is one of the most diagnosed cancers worldwide. It develops due to an unrestrained Sonic Hedgehog (SHH) signaling activity in basal cells of the skin. Certain subtypes of BCC are more aggressive than others, although the molecular basis of this phenomenon remains unknown. We have previously reported that Neogenin-1 (NEO1) is a downstream target gene of the SHH/GLI pathway in neural tissue. Given that SHH participates in epidermal homeostasis, here we analyzed the epidermal expression of NEO1 in order to identify whether it plays a role in adult epidermis or BCC. We describe the mRNA and protein expression profile of NEO1 and its ligands (Netrin-1 and RGMA) in human and mouse control epidermis and in a broad range of human BCCs. We identify in human BCC a significant positive correlation in the levels of NEO1 receptor, NTN-1 and RGMA ligands with respect to GLI1, the main target gene of the canonical SHH pathway. Moreover, we show via cyclopamine inhibition of the SHH/GLI pathway of ex vivo cultures that NEO1 likely functions as a downstream target of SHH/GLI signaling in the skin. We also show how Neo1 expression decreases throughout BCC progression in the K14-Cre:Ptch1lox/lox mouse model and that aggressive subtypes of human BCC exhibit lower levels of NEO1 than non-aggressive BCC samples. Taken together, these data suggest that NEO1 is a SHH/GLI target in epidermis. We propose that NEO1 may be important in tumor onset and is then down-regulated in advanced BCC or aggressive subtypes. PMID:29137400

Coexistence pressure for a martensitic transformation from theory and experiment: Revisiting the bcc-hcp transition of iron under pressure

DOE PAGES

Zarkevich, N. A.; Johnson, D. D.

2015-05-12

We revisit results from decades of pressure experiments on the bcc ↔ hcp transformations in iron, which are sensitive to non-hydrostatic conditions and sample size. We emphasize the role of martensitic stress in the observed pressure hysteresis and address the large spread in values for onset pressures of the nucleating phase. From electronic-structure calculations, we find a bcc ↔ hcp equilibrium coexistence pressure of 8.4 GPa. Accounting for non-hydrostatic martensitic stress and a stress-dependent transition barrier, we suggest a pressure inequality for better comparison to experiment and observed hysteresis. We construct the equation of state for bcc and hcp phasesmore » under hydrostatic pressure, and compare to experiments and previous calculations.« less

Localization of Burkholderia cepacia Complex Bacteria in Cystic Fibrosis Lungs and Interactions with Pseudomonas aeruginosa in Hypoxic Mucus

PubMed Central

Abdullah, Lubna H.; Perlmutt, Olivia S.; Albert, Daniel; Davis, C. William; Arnold, Roland R.; Yankaskas, James R.; Gilligan, Peter; Neubauer, Heiner; Randell, Scott H.; Boucher, Richard C.

2014-01-01

The localization of Burkholderia cepacia complex (Bcc) bacteria in cystic fibrosis (CF) lungs, alone or during coinfection with Pseudomonas aeruginosa, is poorly understood. We performed immunohistochemistry for Bcc and P. aeruginosa bacteria on 21 coinfected or singly infected CF lungs obtained at transplantation or autopsy. Parallel in vitro experiments examined the growth of two Bcc species, Burkholderia cenocepacia and Burkholderia multivorans, in environments similar to those occupied by P. aeruginosa in the CF lung. Bcc bacteria were predominantly identified in the CF lung as single cells or small clusters within phagocytes and mucus but not as “biofilm-like structures.” In contrast, P. aeruginosa was identified in biofilm-like masses, but densities appeared to be reduced during coinfection with Bcc bacteria. Based on chemical analyses of CF and non-CF respiratory secretions, a test medium was defined to study Bcc growth and interactions with P. aeruginosa in an environment mimicking the CF lung. When test medium was supplemented with alternative electron acceptors under anaerobic conditions, B. cenocepacia and B. multivorans used fermentation rather than anaerobic respiration to gain energy, consistent with the identification of fermentation products by high-performance liquid chromatography (HPLC). Both Bcc species also expressed mucinases that produced carbon sources from mucins for growth. In the presence of P. aeruginosa in vitro, both Bcc species grew anaerobically but not aerobically. We propose that Bcc bacteria (i) invade a P. aeruginosa-infected CF lung when the airway lumen is anaerobic, (ii) inhibit P. aeruginosa biofilm-like growth, and (iii) expand the host bacterial niche from mucus to also include macrophages. PMID:25156735

Perspectives and reflections on the practice of behaviour change communication for infant and young child feeding.

PubMed

Pelto, Gretel H; Martin, Stephanie L; van Liere, Marti J; Fabrizio, Cecilia S

2016-04-01

Behaviour change communication (BCC) is a critical component of infant and young child feeding (IYCF) interventions. In this study we asked BCC practitioners working in low- and middle-income countries to participate in an examination of BCC practice. We focus here on results of their personal reflections related to larger issues of practice. We used a combination of iterative triangulation and snowball sampling procedures to obtain a sample of 29 BCC professionals. Major themes include (1) participants using tools and guidelines to structure their work, and many consider their organisation's tools to be their most important contribution to the field; (2) they value research to facilitate programme design and implementation; (3) half felt research needed to increase; (4) they have a strong commitment to respecting cultural beliefs and culturally appropriate programming; (5) they are concerned about lack of a strong theoretical foundation for their work. Based on participants' perspectives and the authors' reflections, we identified the following needs: (1) conducting a systematic examination of the alternative theoretical structures that are available for nutrition BCC, followed by a review of the evidence base and suggestions for future programmatic research to fill the gaps in knowledge; (2) developing a checklist of common patterns to facilitate efficiency in formative research; (3) developing an analytic compendium of current IYCF BCC guidelines and tools; (4) developing tools and guidelines that cover the full programme process, including use of innovative channels to support 'scaling up nutrition'; and (5) continued support for programmes of proven effectiveness. © 2015 John Wiley & Sons Ltd.

Morphology of basal cell carcinoma in high definition optical coherence tomography: en-face and slice imaging mode, and comparison with histology.

PubMed

Maier, T; Braun-Falco, M; Hinz, T; Schmid-Wendtner, M H; Ruzicka, T; Berking, C

2013-01-01

Optical coherence tomography (OCT) allows real-time, in vivo examination of basal cell carcinoma (BCC). A new high definition OCT with high lateral and axial resolution in a horizontal (en-face) and vertical (slice) imaging mode offers additional information in the diagnosis of BCC and may potentially replace invasive diagnostic biopsies. To define the characteristic morphologic features of BCC by using high definition optical coherence tomography (HD-OCT) compared to conventional histology. A total of 22 BCCs were examined preoperatively by HD-OCT in the en-face and slice imaging mode and characteristic features were evaluated in comparison to the histopathological findings. The following features were found in the en-face mode of HD-OCT: lobulated nodules (20/22), peripheral rimming (17/22), epidermal disarray (21/22), dilated vessels (11/22) and variably refractile stroma (19/22). In the slice imaging mode the following characteristics were found: grey/dark oval structures (18/22), peripheral rimming (13/22), destruction of layering (22/22), dilated vessels (7/22) and peritumoural bright stroma (11/22). In the en-face mode the lobulated structure of the BCC was more distinct than in the slice mode compared to histology. HD-OCT with a horizontal and vertical imaging mode offers additional information in the diagnosis of BCC compared to conventional OCT imaging and enhances the feasibility of non-invasive diagnostics of BCC. © 2012 The Authors. Journal of the European Academy of Dermatology and Venereology © 2012 European Academy of Dermatology and Venereology.

The Embedded Atom Model and large-scale MD simulation of tin under shock loading

NASA Astrophysics Data System (ADS)

Sapozhnikov, F. A.; Ionov, G. V.; Dremov, V. V.; Soulard, L.; Durand, O.

2014-05-01

The goal of the work was to develop an interatomic potential, that can be used in large-scale classical MD simulations to predict tin properties near the melting curve, the melting curve itself, and the kinetics of melting and solidification when shock and ramp loading. According to phase diagram, shocked tin melts from bcc phase, and since the main objective was to investigate melting, the EAM was parameterized for bcc phase. The EAM was optimized using isothermal compression data (experimental at T=300 K and ab-initio at T=0 K for bcc, fcc, bct structures), experimental and QMD data on the Hugoniot and on the melting at elevated pressures. The Hugoniostat calculations centred at β-tin at ambient conditions showed that the calculated Hugoniot is in good agreement with experimental and QMD data above p-bct transition pressure. Calculations of overcooled liquid in pressure range corresponding to bcc phase showed crystallization into bcc phase. Since the principal Hugoniot of tin originates from the β-tin that is not described by this EAM the special initial state of bcc samples was constructed to perform large-scale MD simulations of shock loading.

Shellwise Mackay transformation in iron nanoclusters.

PubMed

Rollmann, Georg; Gruner, Markus E; Hucht, Alfred; Meyer, Ralf; Entel, Peter; Tiago, Murilo L; Chelikowsky, James R

2007-08-24

Structure and magnetism of iron clusters with up to 641 atoms have been investigated by means of density functional theory calculations including full geometric optimizations. Body-centered cubic (bcc) isomers are found to be lowest in energy when the clusters contain more than about 100 atoms. In addition, another stable conformation has been identified for magic-number clusters, which lies well within the range of thermal energies as compared to the bcc isomers. Its structure is characterized by a close-packed particle core and an icosahedral surface, while intermediate shells are partially transformed along the Mackay path between icosahedral and cuboctahedral geometry. The gradual transformation results in a favorable bcc environment for the subsurface atoms. For Fe55, the shellwise Mackay-transformed morphology is a promising candidate for the ground state.

Metastable bcc mischmetal-magnesium alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sabariz, A.L.R.

1989-02-01

The bcc phase in the MM-Mg system can be metastably retained at room temperature for magnesium composition within the range 16 at.% - 20 at.%. The retention of a lower composition was restricted by quenching rate and at higher concentrations by intermetallic compound precipitation. The lattice parameter for the pure bcc mischmetal phase was determined by extrapolation. The value obtained (a/sub E/ = 4.131 /angstrom/) was in good agreement with the theoretical value (a/sub t/ = 4.156 /angstrom/). Magnetic susceptibility data suggested that bcc mischmetal-magnesium alloys underwent a change from paramagnetic to antiferromagnetic behavior on cooling at /approximately/20 K, independentmore » of magnesium composition. The value found for the magnetic effective moment per gram-atom-magnetic-rare earth of each bcc MM-Mg alloy examined (MM - 16 Mg, MM - 18 Mg and MM - 20 Mg) was found to be constant (p/sub eff/ approx. 1.62 ..mu../sub B/), independent of the magnesium composition. The observed Curie-Weiss temperature values decreasing with the magnesium content increasing were due to magnetic dilution. The equilibrium reaction bcc ..-->.. dhcp + MMMg presented an undercooling effect of /approximately/40/degree/C around the eutectoid composition (/approximately/17 at.% Mg). The sluggish character of this reaction was considered the strongest effect for the bcc structure retention in the mischmetal-magnesium system. 16 refs., 27 figs.« less

Wulff polyhedra derived from morse potentials and crystal habits of bcc and fcc metal particles

NASA Astrophysics Data System (ADS)

Saito, Yahachi

1981-05-01

Using the broken-bond method and the pairwise potentials of Morse type, relative surface energies were calculated to derive the Wulff polyhedra for bcc and fcc metals. When only the first and the second nearest neighbour interactions are taken into account, the resulting Wulff polyhedron is a rhombic dodecahedron truncated by {100} faces and an octahedron truncated by {100} and {100} faces for bcc and fcc metals, respectively. The truncation degrees calculated are in good agreement with those measured from smoke particles grown in an atmosphere of rarefied inactive gas. The effect of the higher order terms of interactions is simply to make the edges and corners round.

Cascade morphology transition in bcc metals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Setyawan, Wahyu; Selby, A.; Juslin, Niklas

2015-06-10

Energetic atom collisions in solids induce shockwaves with complex morphologies. In this paper, we establish the existence of a morphological transition in such cascades. The order parameter of the morphology is defined as the exponent,more » $b$, in the defect production curve as a function of cascade energy ($$N_F$$$ \\sim$$$E_{MD}^b$$). Response of different bcc metals can be compared in a consistent energy domain when the energy is normalized by the transition energy, $$\\mu$$, between the high- and the low-energy regime. Using Cr, Fe, Mo and W data, an empirical formula of $$\\mu$$ as a function of displacement threshold energy, $$E_d$$, is presented for bcc metals.« less

Cascade morphology transition in bcc metals

DOE PAGES

Setyawan, Wahyu; Selby, Aaron P.; Juslin, Niklas; ...

2015-05-18

Energetic atom collisions in solids induce shockwaves with complex morphologies. In this paper, we establish the existence of a morphological transition in such cascades. The order parameter of the morphology is defined as the exponent, b, in the defect production curve as a function of cascade energy (N-F similar to E-MD(b)). Response of different bcc metals can be compared in a consistent energy domain when the energy is normalized by the transition energy, mu, between the high-and the low-energy regime. Using Cr, Fe, Mo and W data, an empirical formula of mu as a function of displacement threshold energy, E-d,more » is presented for bcc metals.« less

MD modeling of screw dislocation influence upon initiation and mechanism of BCC-HCP polymorphous transition in iron

NASA Astrophysics Data System (ADS)

Dremov, V. V.; Ionov, G. V.; Sapozhnikov, F. A.; Smirnov, N. A.; Karavaev, A. V.; Vorobyova, M. A.; Ryzhkov, M. V.

2015-09-01

The present work is devoted to classical molecular dynamics investigation into microscopic mechanisms of the bcc-hcp transition in iron. The interatomic potential of EAM type used in the calculations was tested for the capability to reproduce ab initio data on energy evolution along the bcc-hcp transformation path (Burgers deformation + shuffe) and then used in the large-scale MD simulations. The large-scale simulations included constant volume deformation along the Burgers path to study the origin and nature of the plasticity, hydrostatic volume compression of defect free samples above the bcc to hcp transition threshold to observe the formation of new phase embryos, and the volume compression of samples containing screw dislocations to study the effect of the dislocations on the probability of the new phase critical embryo formation. The volume compression demonstrated high level of metastability. The transition starts at pressure much higher than the equilibrium one. Dislocations strongly affect the probability of the critical embryo formation and significantly reduce the onset pressure of transition. The dislocations affect also the resulting structure of the samples upon the transition. The formation of layered structure is typical for the samples containing the dislocations. The results of the simulations were compared with the in-situ experimental data on the mechanism of the bcc-hcp transition in iron.

Microstructure and Room-Temperature Mechanical Properties of FeCrMoVTi x High-Entropy Alloys

NASA Astrophysics Data System (ADS)

Guo, Jun; Huang, Xuefei; Huang, Weigang

2017-07-01

FeCrMoVTi x ( x values represent the molar ratio, where x = 0, 0.5, 1.0, 1.5, and 2.0) high-entropy alloys were prepared by a vacuum arc melting method. The effects of Ti element on the microstructure and room-temperature mechanical properties of the as-cast FeCrMoVTi x alloys were investigated. The results show that the prepared alloys exhibited typical dendritic microstructure and the size of the microstructure became fine with increasing Ti content. The FeCrMoV alloy exhibited a single body-centered cubic structure (BCC1) and the alloys prepared with Ti element exhibited BCC1 + BCC2 mixed structure. The new BCC2 phase is considered as (Fe, Ti)-rich phase and was distributed in the dendrite region. With the increase of Ti content, the volume fraction of the BCC2 phase increased and its shape changed from a long strip to a network. For the FeCrMoV alloy, the fracture strength, plastic strain, and hardness reached as high as 2231 MPa, 28.2%, and 720 HV, respectively. The maximum hardness of 887 HV was obtained in the FeCrMoVTi alloy. However, the fracture strength, yield stress, and plastic strain of the alloys decreased continuously as Ti content increased. In the room-temperature compressive test, the alloys showed typical brittle fracture characteristics.

Classification of different kinds of pesticide residues on lettuce based on fluorescence spectra and WT-BCC-SVM algorithm

NASA Astrophysics Data System (ADS)

Zhou, Xin; Jun, Sun; Zhang, Bing; Jun, Wu

2017-07-01

In order to improve the reliability of the spectrum feature extracted by wavelet transform, a method combining wavelet transform (WT) with bacterial colony chemotaxis algorithm and support vector machine (BCC-SVM) algorithm (WT-BCC-SVM) was proposed in this paper. Besides, we aimed to identify different kinds of pesticide residues on lettuce leaves in a novel and rapid non-destructive way by using fluorescence spectra technology. The fluorescence spectral data of 150 lettuce leaf samples of five different kinds of pesticide residues on the surface of lettuce were obtained using Cary Eclipse fluorescence spectrometer. Standard normalized variable detrending (SNV detrending), Savitzky-Golay coupled with Standard normalized variable detrending (SG-SNV detrending) were used to preprocess the raw spectra, respectively. Bacterial colony chemotaxis combined with support vector machine (BCC-SVM) and support vector machine (SVM) classification models were established based on full spectra (FS) and wavelet transform characteristics (WTC), respectively. Moreover, WTC were selected by WT. The results showed that the accuracy of training set, calibration set and the prediction set of the best optimal classification model (SG-SNV detrending-WT-BCC-SVM) were 100%, 98% and 93.33%, respectively. In addition, the results indicated that it was feasible to use WT-BCC-SVM to establish diagnostic model of different kinds of pesticide residues on lettuce leaves.

Bulk and monolayer ordering of block copolymer blends

NASA Astrophysics Data System (ADS)

Onikoyi, Adetunji J.

The control of the nanoscale structure or morphology of a block copolymer is a desired goal for nanolithography applications. In this work, we are particularly interested in providing guides for controlling domain size, domain shape and defect densities in block copolymers and their blends for thin film applications. To reach this goal, a sphere forming PS-b-P2VP (having a PS majority block) and its blends with PS homopolymer or cylinder forming PS-b-P2VP are studied in both the bulk and thin films. Structure characterization is performed using a variety of experimental techniques including small angle X-ray scattering, scanning force microscopy and transmission electron microscopy. In the bulk, the spherical domains of the pure, sphere forming PS-b-P2VP arrange on a BCC lattice. On adding PS homopolymer (hPS), the lattice parameter of the BCC spheres increases, while the order-to-disorder temperature (ODT) of the BCC lattice simultaneously decreases. At a given hPS composition, the use of larger sized hPS leads to larger increases in the lattice parameter and larger decreases in the ODT. In bulk blends of cylinder forming PS-b-P2VP with sphere forming PS-b-P2VP, the ordered morphology changes (e.g., cylindrical morphology → coexisting spherical and cylindrical morphologies → spherical morphology) as the sphere forming PS-b-P2VP volume fraction phis increases, while the ODT of the cylindrical morphology decreases. The phase boundaries of these morphologies in monolayers shift to lower phis compared to those of the bulk, apparently caused by a selective adsorption of the cylindrical PS-b-P2VP to form a brush on the substrate. This selective adsorption leads to a preference for spherical domains in diamond-shaped lateral confinements when cylindrical domains are stabilized outside the confinements on the same substrate. Finally, we explore the use of graphoepitaxy to order monolayers of sphere forming PS-b-P2VP and its blends with hPS. The probability of forming isolated dislocations, or of adding (or removing) a full row of spherical domains, in diamond-shaped lateral confinements is shown to be higher when the well size is incommensurate with the lattice parameter. Square-shaped lateral confinement leads to a preference for square sphere packing if the PS-b-P2VP is blended with appropriate amounts of hPS.

Calculated temperature dependence of elastic constants and phonon dispersion of hcp and bcc beryllium

NASA Astrophysics Data System (ADS)

Hahn, Steven; Arapan, Sergiu; Harmon, Bruce; Eriksson, Olle

2011-03-01

Conventional first principle methods for calculating lattice dynamics are unable to calculate high temperature thermophysical properties of materials containing modes that are entropically stabilized. In this presentation we use a relatively new approach called self-consistent ab initio lattice dynamics (SCAILD) to study the hcp to bcc transition (1530 K) in beryllium. The SCAILD method goes beyond the harmonic approximation to include phonon-phonon interactions and produces a temperature-dependent phonon dispersion. In the high temperature bcc structure, phonon-phonon interactions dynamically stabilize the N-point phonon. Fits to the calculated phonon dispersion were used to determine the temperature dependence of the elastic constants in the hcp and bcc phases. Work at the Ames Laboratory was supported by the Department of Energy-Basic Energy Sciences under Contract No. DE-AC02-07CH11358.

Classifying distinct basal cell carcinoma subtype by means of dermatoscopy and reflectance confocal microscopy.

PubMed

Longo, Caterina; Lallas, Aimilios; Kyrgidis, Athanassios; Rabinovitz, Harold; Moscarella, Elvira; Ciardo, Silvana; Zalaudek, Iris; Oliviero, Margaret; Losi, Amanda; Gonzalez, Salvador; Guitera, Pascale; Piana, Simonetta; Argenziano, Giuseppe; Pellacani, Giovanni

2014-10-01

The current guidelines for the management of basal cell carcinoma (BCC) suggest a different therapeutic approach according to histopathologic subtype. Although dermatoscopic and confocal criteria of BCC have been investigated, no specific studies were performed to evaluate the distinct reflectance confocal microscopy (RCM) aspects of BCC subtypes. To define the specific dermatoscopic and confocal criteria for delineating different BCC subtypes. Dermatoscopic and confocal images of histopathologically confirmed BCCs were retrospectively evaluated for the presence of predefined criteria. Frequencies of dermatoscopic and confocal parameters are provided. Univariate and adjusted odds ratios were calculated. Discriminant analyses were performed to define the independent confocal criteria for distinct BCC subtypes. Eighty-eight BCCs were included. Dermatoscopically, superficial BCCs (n=44) were primarily typified by the presence of fine telangiectasia, multiple erosions, leaf-like structures, and revealed cords connected to the epidermis and epidermal streaming upon RCM. Nodular BCCs (n=22) featured the classic dermatoscopic features and well outlined large basaloid islands upon RCM. Infiltrative BCCs (n=22) featured structureless, shiny red areas, fine telangiectasia, and arborizing vessels on dermatoscopy and dark silhouettes upon RCM. The retrospective design. Dermatoscopy and confocal microscopy can reliably classify different BCC subtypes. Copyright © 2014 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

Formation of bcc non-equilibrium La, Gd and Dy alloys and the magnetic structure of Mg-stabilized. beta. Gd and. beta. Dy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Herchenroeder, J.W.

1989-02-01

The high temperature bcc allotrope of a rare earth metal has the potential for substantially different magnetic properties than the room temperature hexagonal (hcp or dhcp) counterpart because of its more symmetrical crystal field. The stabilization by alloying and quenching of this bcc phase was studied for La-M alloys where M is an non-rare earth metal from Group II or III. The factors influencing the stabilization, such as size of M and quench rate, are discussed. ..gamma..La (bcc) could be retained over a composition range around the eutectoid composition by Mg or Cd alloying. A comparison of T/sub o/ curvesmore » of the various alloy systems suggest that the eutectoid temperature of the La-M system must be approximately equal to or less than a critical T/sub o/ temperature of 515/degree/C if the bcc phase is to be retained by quenching. The thermal stability of ..beta..Gd (bcc) was investigated by DTA and isothermal annealing. It was found to transform to an intermediate phase before reverting to the equilibrium phases in contrast to ..gamma..La alloys which decompose directly on heating to the equilibrium phases. 71 refs., 52 figs., 7 tabs.« less

A unified relation for the solid-liquid interface free energy of pure FCC, BCC, and HCP metals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, S. R.; Mendelev, M. I., E-mail: mendelev@ameslab.gov

2016-04-14

We study correlations between the solid-liquid interface (SLI) free energy and bulk material properties (melting temperature, latent heat, and liquid structure) through the determination of SLI free energies for bcc and hcp metals from molecular dynamics (MD) simulation. Values obtained for the bcc metals in this study were compared to values predicted by the Turnbull, Laird, and Ewing relations on the basis of previously published MD simulation data. We found that of these three empirical relations, the Ewing relation better describes the MD simulation data. Moreover, whereas the original Ewing relation contains two constants for a particular crystal structure, wemore » found that the first coefficient in the Ewing relation does not depend on crystal structure, taking a common value for all three phases, at least for the class of the systems described by embedded-atom method potentials (which are considered to provide a reasonable approximation for metals).« less

Genome Characterization of Oleaginous Aspergillus oryzae BCC7051: A Potential Fungal-Based Platform for Lipid Production

DOE PAGES

Thammarongtham, Chinae; Nookaew, Intawat; Vorapreeda, Tayvich; ...

2017-09-01

The selected robust fungus, Aspergillus oryzae strain BCC7051 is of interest for biotechnological production of lipid-derived products due to its capability to accumulate high amount of intracellular lipids using various sugars and agro-industrial substrates. Here in this paper, we report the genome sequence of the oleaginous A. oryzae BCC7051. The obtained reads were de novo assembled into 25 scaffolds spanning of 38,550,958 bps with predicted 11,456 protein-coding genes. By synteny mapping, a large rearrangement was found in two scaffolds of A. oryzae BCC7051 as compared to the reference RIB40 strain. The genetic relationship between BCC7051 and other strains of A.more » oryzae in terms of aflatoxin production was investigated, indicating that the A. oryzae BCC7051 was categorized into group 2 nonaflatoxin-producing strain. Moreover, a comparative analysis of the structural genes focusing on the involvement in lipid metabolism among oleaginous yeast and fungi revealed the presence of multiple isoforms of metabolic enzymes responsible for fatty acid synthesis in BCC7051. The alternative routes of acetyl-CoA generation as oleaginous features and malate/citrate/pyruvate shuttle were also identified in this A. oryzae strain. The genome sequence generated in this work is a dedicated resource for expanding genome-wide study of microbial lipids at systems level, and developing the fungal-based platform for production of diversified lipids with commercial relevance.« less

Genome Characterization of Oleaginous Aspergillus oryzae BCC7051: A Potential Fungal-Based Platform for Lipid Production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thammarongtham, Chinae; Nookaew, Intawat; Vorapreeda, Tayvich

The selected robust fungus, Aspergillus oryzae strain BCC7051 is of interest for biotechnological production of lipid-derived products due to its capability to accumulate high amount of intracellular lipids using various sugars and agro-industrial substrates. Here in this paper, we report the genome sequence of the oleaginous A. oryzae BCC7051. The obtained reads were de novo assembled into 25 scaffolds spanning of 38,550,958 bps with predicted 11,456 protein-coding genes. By synteny mapping, a large rearrangement was found in two scaffolds of A. oryzae BCC7051 as compared to the reference RIB40 strain. The genetic relationship between BCC7051 and other strains of A.more » oryzae in terms of aflatoxin production was investigated, indicating that the A. oryzae BCC7051 was categorized into group 2 nonaflatoxin-producing strain. Moreover, a comparative analysis of the structural genes focusing on the involvement in lipid metabolism among oleaginous yeast and fungi revealed the presence of multiple isoforms of metabolic enzymes responsible for fatty acid synthesis in BCC7051. The alternative routes of acetyl-CoA generation as oleaginous features and malate/citrate/pyruvate shuttle were also identified in this A. oryzae strain. The genome sequence generated in this work is a dedicated resource for expanding genome-wide study of microbial lipids at systems level, and developing the fungal-based platform for production of diversified lipids with commercial relevance.« less

Diagnosis of basal cell carcinoma by two photon excited fluorescence combined with lifetime imaging

NASA Astrophysics Data System (ADS)

Fan, Shunping; Peng, Xiao; Liu, Lixin; Liu, Shaoxiong; Lu, Yuan; Qu, Junle

2014-02-01

Basal cell carcinoma (BCC) is the most common type of human skin cancer. The traditional diagnostic procedure of BCC is histological examination with haematoxylin and eosin staining of the tissue biopsy. In order to reduce complexity of the diagnosis procedure, a number of noninvasive optical methods have been applied in skin examination, for example, multiphoton tomography (MPT) and fluorescence lifetime imaging microscopy (FLIM). In this study, we explored two-photon optical tomography of human skin specimens using two-photon excited autofluorescence imaging and FLIM. There are a number of naturally endogenous fluorophores in skin sample, such as keratin, melanin, collagen, elastin, flavin and porphyrin. Confocal microscopy was used to obtain structures of the sample. Properties of epidermic and cancer cells were characterized by fluorescence emission spectra, as well as fluorescence lifetime imaging. Our results show that two-photon autofluorescence lifetime imaging can provide accurate optical biopsies with subcellular resolution and is potentially a quantitative optical diagnostic method in skin cancer diagnosis.

Microstructural Design for Improving Ductility of An Initially Brittle Refractory High Entropy Alloy.

PubMed

Soni, V; Senkov, O N; Gwalani, B; Miracle, D B; Banerjee, R

2018-06-11

Typically, refractory high-entropy alloys (RHEAs), comprising a two-phase ordered B2 + BCC microstructure, exhibit extraordinarily high yield strengths, but poor ductility at room temperature, limiting their engineering application. The poor ductility is attributed to the continuous matrix being the ordered B2 phase in these alloys. This paper presents a novel approach to microstructural engineering of RHEAs to form an "inverted" BCC + B2 microstructure with discrete B2 precipitates dispersed within a continuous BCC matrix, resulting in improved room temperature compressive ductility, while maintaining high yield strength at both room and elevated temperature.

Thermodynamics of concentrated solid solution alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Michael C.; Zhang, C.; Gao, P.

This study reviews the three main approaches for predicting the formation of concentrated solid solution alloys (CSSA) and for modeling their thermodynamic properties, in particular, utilizing the methodologies of empirical thermo-physical parameters, CALPHAD method, and first-principles calculations combined with hybrid Monte Carlo/Molecular Dynamics (MC/MD) simulations. In order to speed up CSSA development, a variety of empirical parameters based on Hume-Rothery rules have been developed. Herein, these parameters have been systematically and critically evaluated for their efficiency in predicting solid solution formation. The phase stability of representative CSSA systems is then illustrated from the perspectives of phase diagrams and nucleation drivingmore » force plots of the σ phase using CALPHAD method. The temperature-dependent total entropies of the FCC, BCC, HCP, and σ phases in equimolar compositions of various systems are presented next, followed by the thermodynamic properties of mixing of the BCC phase in Al-containing and Ti-containing refractory metal systems. First-principles calculations on model FCC, BCC and HCP CSSA reveal the presence of both positive and negative vibrational entropies of mixing, while the calculated electronic entropies of mixing are negligible. Temperature dependent configurational entropy is determined from the atomic structures obtained from MC/MD simulations. Current status and challenges in using these methodologies as they pertain to thermodynamic property analysis and CSSA design are discussed.« less

Thermodynamics of concentrated solid solution alloys

DOE PAGES

Gao, Michael C.; Zhang, C.; Gao, P.; ...

2017-10-12

This study reviews the three main approaches for predicting the formation of concentrated solid solution alloys (CSSA) and for modeling their thermodynamic properties, in particular, utilizing the methodologies of empirical thermo-physical parameters, CALPHAD method, and first-principles calculations combined with hybrid Monte Carlo/Molecular Dynamics (MC/MD) simulations. In order to speed up CSSA development, a variety of empirical parameters based on Hume-Rothery rules have been developed. Herein, these parameters have been systematically and critically evaluated for their efficiency in predicting solid solution formation. The phase stability of representative CSSA systems is then illustrated from the perspectives of phase diagrams and nucleation drivingmore » force plots of the σ phase using CALPHAD method. The temperature-dependent total entropies of the FCC, BCC, HCP, and σ phases in equimolar compositions of various systems are presented next, followed by the thermodynamic properties of mixing of the BCC phase in Al-containing and Ti-containing refractory metal systems. First-principles calculations on model FCC, BCC and HCP CSSA reveal the presence of both positive and negative vibrational entropies of mixing, while the calculated electronic entropies of mixing are negligible. Temperature dependent configurational entropy is determined from the atomic structures obtained from MC/MD simulations. Current status and challenges in using these methodologies as they pertain to thermodynamic property analysis and CSSA design are discussed.« less

Automatic dirt trail analysis in dermoscopy images.

PubMed

Cheng, Beibei; Joe Stanley, R; Stoecker, William V; Osterwise, Christopher T P; Stricklin, Sherea M; Hinton, Kristen A; Moss, Randy H; Oliviero, Margaret; Rabinovitz, Harold S

2013-02-01

Basal cell carcinoma (BCC) is the most common cancer in the US. Dermatoscopes are devices used by physicians to facilitate the early detection of these cancers based on the identification of skin lesion structures often specific to BCCs. One new lesion structure, referred to as dirt trails, has the appearance of dark gray, brown or black dots and clods of varying sizes distributed in elongated clusters with indistinct borders, often appearing as curvilinear trails. In this research, we explore a dirt trail detection and analysis algorithm for extracting, measuring, and characterizing dirt trails based on size, distribution, and color in dermoscopic skin lesion images. These dirt trails are then used to automatically discriminate BCC from benign skin lesions. For an experimental data set of 35 BCC images with dirt trails and 79 benign lesion images, a neural network-based classifier achieved a 0.902 are under a receiver operating characteristic curve using a leave-one-out approach. Results obtained from this study show that automatic detection of dirt trails in dermoscopic images of BCC is feasible. This is important because of the large number of these skin cancers seen every year and the challenge of discovering these earlier with instrumentation. © 2011 John Wiley & Sons A/S.

Ab initio theory of noble gas atoms in bcc transition metals.

PubMed

Jiang, Chao; Zhang, Yongfeng; Gao, Yipeng; Gan, Jian

2018-06-18

Systematic ab initio calculations based on density functional theory have been performed to gain fundamental understanding of the interactions between noble gas atoms (He, Ne, Ar and Kr) and bcc transition metals in groups 5B (V, Nb and Ta), 6B (Cr, Mo and W) and 8B (Fe). Our charge density analysis indicates that the strong polarization of nearest-neighbor metal atoms by noble gas interstitials is the electronic origin of their high formation energies. Such polarization becomes more significant with an increasing gas atom size and interstitial charge density in the host bcc metal, which explains the similar trend followed by the unrelaxed formation energies of noble gas interstitials. Upon allowing for local relaxation, nearby metal atoms move farther away from gas interstitials in order to decrease polarization, albeit at the expense of increasing the elastic strain energy. Such atomic relaxation is found to play an important role in governing both the energetics and site preference of noble gas atoms in bcc metals. Our most notable finding is that the fully relaxed formation energies of noble gas interstitials are strongly correlated with the elastic shear modulus of the bcc metal, and the physical origin of this unexpected correlation has been elucidated by our theoretical analysis based on the effective-medium theory. The kinetic behavior of noble gas atoms and their interaction with pre-existing vacancies in bcc transition metals have also been discussed in this work.

Basal Cell Carcinoma Arising within Seborrheic Keratosis

PubMed Central

Yurdakul, Cüneyt; Güçer, Hasan; Sehitoglu, Ibrahim

2014-01-01

Malignant tumour development within a seborrheic keratosis (SK) is extremely rare. Though the most commonly developed malignant tumour is the basal cell carcinoma (BCC), other tumour types have also been reported in literature. Herein, we will report a superficial type BCC case developed within SK localized in hairy skin of a 78-year-old female patient. In immunohistochemical evaluation, diffuse positive staining with CK19 and over-expression in p53 compared with non-neoplastic areas were determined in neoplastic basaloid islands. It is always not easy to differentiate especially superficial type BCC cases from non-neoplastic epithelium of SK with histopathological evaluation. As far as this reason we believe that in difficult differentiation of these 2 lesions, in order to show the differentiation in basal epithelium, immunohistochemical evaluation may be helpful. PMID:25177624

Antitubercular Activity of Mycelium-Associated Ganoderma Lanostanoids.

PubMed

Isaka, Masahiko; Chinthanom, Panida; Sappan, Malipan; Supothina, Sumalee; Vichai, Vanicha; Danwisetkanjana, Kannawat; Boonpratuang, Thitiya; Hyde, Kevin D; Choeyklin, Rattaket

2017-05-26

In a continuation of our research into antitubercular lanostane triterpenoids from submerged cultures of Ganoderma species, three strains, Ganoderma orbiforme BCC 22325, Ganoderma sp. BCC 60695, and Ganoderma australe BCC 22314, have been investigated. Fourteen new lanostane triterpenoids, together with 35 known compounds, were isolated. Antitubercular activities of these mycelium-associated Ganoderma lanostanoids against Mycobacterium tuberculosis H37Ra were evaluated. Taken together with the assay data of previously isolated compounds, structure-activity relationships of the antitubercular activity are proposed. Most importantly, 3β- and 15α-acetoxy groups were shown to be critical for antimycobacterial activity. The most potent compound was (24E)-3β,15α-diacetoxylanosta-7,9(11),24-trien-26-oic acid (35).

DNA-guided nanoparticle assemblies

DOEpatents

Gang, Oleg; Nykypanchuk, Dmytro; Maye, Mathew; van der Lelie, Daniel

2013-07-16

In some embodiments, DNA-capped nanoparticles are used to define a degree of crystalline order in assemblies thereof. In some embodiments, thermodynamically reversible and stable body-centered cubic (bcc) structures, with particles occupying <.about.10% of the unit cell, are formed. Designs and pathways amenable to the crystallization of particle assemblies are identified. In some embodiments, a plasmonic crystal is provided. In some aspects, a method for controlling the properties of particle assemblages is provided. In some embodiments a catalyst is formed from nanoparticles linked by nucleic acid sequences and forming an open crystal structure with catalytically active agents attached to the crystal on its surface or in interstices.

Direct Observation of the BCC (100) Plane in Thin Films of Sphere-forming Diblock Copolymers

NASA Astrophysics Data System (ADS)

Ji, Shengxiang; Nagpal, Umang; Liao, Wen; de Pablo, Juan; Nealey, Paul

2010-03-01

In sphere-forming diblock copolymers, periodic arrays of spheres are arranged in a body-centred cubic (BCC) lattice structure in bulk. However, in thin films different surface morphologies were observed as a function of the film thickness, and the transition from the hexagonal array to the BCC (110) arrangement of spheres on film surfaces was located with respect to the increase of the film thickness. Here we report the first direct observation of the BCC (100) plane in thin films of poly (styrene-b-methyl methacrylate) diblock copolymers on homogeneous substrates. By balancing the surface energies of both blocks, the lower energy BCC (100) plane corresponding to a square arrangement of half spheres, formed on film surfaces when the film thickness was commensurate with the spacing, L100, between (100) planes or greater than 2 L100. A hexagonal arrangement of spheres was only observed when the thickness was less than 2 L100 and incommensurate with 1 L100. Monte Carlo (MC) simulation confirmed our experimental observation and was used to investigate the transition of the arrangement of spheres as a function of the film thickness.

Dodecagonal quasicrystalline order in a diblock copolymer melt.

PubMed

Gillard, Timothy M; Lee, Sangwoo; Bates, Frank S

2016-05-10

We report the discovery of a dodecagonal quasicrystalline state (DDQC) in a sphere (micelle) forming poly(isoprene-b-lactide) (IL) diblock copolymer melt, investigated as a function of time following rapid cooling from above the order-disorder transition temperature (TODT = 66 °C) using small-angle X-ray scattering (SAXS) measurements. Between TODT and the order-order transition temperature TOOT = 42 °C, an equilibrium body-centered cubic (BCC) structure forms, whereas below TOOT the Frank-Kasper σ phase is the stable morphology. At T < 40 °C the supercooled disordered state evolves into a metastable DDQC that transforms with time to the σ phase. The times required to form the DDQC and σ phases are strongly temperature dependent, requiring several hours and about 2 d at 35 °C and more than 10 and 200 d at 25 °C, respectively. Remarkably, the DDQC forms only from the supercooled disordered state, whereas the σ phase grows directly when the BCC phase is cooled below TOOT and vice versa upon heating. A transition in the rapidly supercooled disordered material, from an ergodic liquid-like arrangement of particles to a nonergodic soft glassy-like solid, occurs below ∼40 °C, coincident with the temperature associated with the formation of the DDQC. We speculate that this stiffening reflects the development of particle clusters with local tetrahedral or icosahedral symmetry that seed growth of the temporally transient DDQC state. This work highlights extraordinary opportunities to uncover the origins and stability of aperiodic order in condensed matter using model block polymers.

Raman spectroscopy reveals biophysical markers in skin cancer surgical margins

NASA Astrophysics Data System (ADS)

Feng, Xu; Moy, Austin J.; Nguyen, Hieu T. M.; Zhang, Yao; Fox, Matthew C.; Sebastian, Katherine R.; Reichenberg, Jason S.; Markey, Mia K.; Tunnell, James W.

2018-02-01

The recurrence rate of nonmelanoma skin cancer is highly related to the residual tumor after surgery. Although tissueconserving surgery, such as Mohs surgery, is a standard method for the treatment of nonmelanoma skin cancer, they are limited by lengthy and costly frozen-section histopathology. Raman spectroscopy (RS) is proving to be an objective, sensitive, and non-destructive tool for detecting skin cancer. Previous studies demonstrated the high sensitivity of RS in detecting tumor margins of basal cell carcinoma (BCC). However, those studies rely on statistical classification models and do not elucidate the skin biophysical composition. As a result, we aim to discover the biophysical differences between BCC and primary normal skin structures (including epidermis, dermis, hair follicle, sebaceous gland and fat). We obtained freshly resected ex vivo skin samples from fresh resection specimens from 14 patients undergoing Mohs surgery. Raman images were acquired from regions containing one or more structures using a custom built 830nm confocal Raman microscope. The spectra were grouped using K-means clustering analysis and annotated as either BCC or each of the five normal structures by comparing with the histopathology image of the serial section. The spectral data were then fit by a previously established biophysical model with eight primary skin constituents. Our results show that BCC has significant differences in the fit coefficients of nucleus, collagen, triolein, keratin and elastin compared with normal structures. Our study reveals RS has the potential to detect biophysical changes in resection margins, and supports the development of diagnostic algorithms for future intraoperative implementation of RS during Mohs surgery.

First-principles theory of iron up to earth-core pressures: Structural, vibrational, and elastic properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soederlind, P.; Moriarty, J.A.; Wills, J.M.

1996-06-01

{ital Ab} {ital initio} electronic-structure calculations, based on density-functional theory and a full-potential linear-muffin-tin-orbital method, have been used to predict crystal-structure phase stabilities, elastic constants, and Brillouin-zone-boundary phonons for iron under compression. Total energies for five crystal structures, bcc, fcc, bct, hcp, and dhcp, have been calculated over a wide volume range. In agreement with experiment and previous theoretical calculations, a magnetic bcc ground state is obtained at ambient pressure and a nonmagnetic hcp ground state is found at high pressure, with a predicted bcc {r_arrow} hcp phase transition at about 10 GPa. Also in agreement with very recent diamond-anvil-cellmore » experiments, a metastable dhcp phase is found at high pressure, which remains magnetic and consequently accessible at high temperature up to about 50 GPa. In addition, the bcc structure becomes mechanically unstable at pressures above 2 Mbar (200 GPa) and a metastable, but still magnetic, bct phase ({ital c}/{ital a} {approx_equal} 0.875) develops. For high-pressure nonmagnetic iron, fcc and hcp elastic constants and fcc phonon frequencies have been calculated to above 4 Mbar. These quantities rise smoothly with pressure, but an increasing tendency towards elastic anisotropy as a function of compression is observed, and this has important implications for the solid inner-core of the earth. The fcc elastic-constant and phonon data have also been used in combination with generalized pseudopotential theory to develop many-body interatomic potentials, from which high-temperature thermodynamic properties and melting can be obtained. In this paper, these potentials have been used to calculate full fcc and hcp phonon spectra and corresponding Debye temperatures as a function of compression. {copyright} {ital 1996 The American Physical Society.}« less

Cytological diagnosis of basal cell carcinoma and actinic keratosis, using Papanicolaou and May-Grünwald-Giemsa stained cutaneous tissue smear.

PubMed

Christensen, E; Bofin, A; Gudmundsdóttir, I; Skogvoll, E

2008-10-01

Cytology may become the diagnostic method of choice with the advent of new non-invasive treatments for non-melanoma skin cancer, as the sampling technique for cytology entails little tissue disfiguration. The aim of this study was to compare and evaluate the diagnostic performance of scrape cytology using two different cytological staining techniques, and to evaluate additional touch imprint cytology, with that of histopathology of basal cell carcinoma (BCC) and actinic keratosis (AK). We investigated 50 BCC and 28 AK histologically verified lesions, from 41 and 25 patients, respectively. Two separate skin scrape samples and one touch imprint sample were taken from each lesion. The smears were stained with Papanicolaou (Pap) or May-Grünwald-Giemsa (MGG) stains. All cytological specimens were examined in random order by pathologists without knowledge of the histology. Cytodiagnostic results were compared with the histopathological report. Scrape cytodiagnosis agreed with histopathology in 48 (Pap) and 47 (MGG) of the 50 BCC cases, and in 26 of 28 (Pap) and 21 of 26 (MGG) AK cases, yielding sensitivities of 96%, 94%, 93% and 81%, respectively. No significant difference in sensitivity between the two staining methods was found but a trend towards higher Pap sensitivity for AK was noted (P = 0.10). Touch imprint cytology confirmed histopathology in 38 of the 77 cases of BCC and AK. Cytological diagnosis with either Pap or MGG stain for BCC and AK is reliable, and differentiates well between BCC and AK. Imprint cytology proved to be non-diagnostic in half of the examined cases.

Ab initio calculations of the elastic and thermodynamic properties of gold under pressure

NASA Astrophysics Data System (ADS)

Smirnov, N. A.

2017-03-01

The paper presents first-principles FP-LMTO calculations on the relative stability of fcc, bcc, hcp and dhcp gold under pressure. They were done in local density approximation (LDA), as well as in generalized gradient approximation (GGA) with and without spin-orbit interaction. Phonon spectra for the considered gold structures were obtained from LDA calculations within linear response theory and the contribution of lattice vibrations to the free energy of the system was determined in quasiharmonic approximation. Our thorough adjustment of FP-LMTO internal parameters (linearization and tail energies, the MT-sphere radius) helped us to obtain results that agree well with the available experimental phase relation Dubrovinsky et al (2007 Phys. Rev. Lett. 98 045503) between fcc and hcp structures of gold under pressure. The calculations suggest that gold compressed at room temperature successively undergoes the following structural changes: fcc\\to hcp\\to bcc . The paper also presents the calculated elastic constants of fcc, bcc and hcp Au, the principal Hugoniot and the melting curve. Calculated results were used to construct the PT-diagram which describes the relative stability of the gold structures under study up to 500 GPa.

Structural and magnetic properties of FexNi100-x alloys synthesized using Al as a reducing metal

NASA Astrophysics Data System (ADS)

Srakaew, N.; Jantaratana, P.; Nipakul, P.; Sirisathitkul, C.

2017-08-01

Iron-nickel (Fe-Ni) alloys comprising nine different compositions were rapidly synthesized from the redox reaction using aluminum foils as the reducing metal. Compared with conventional chemical syntheses, this simple approach is relatively safe and allows control over the alloy morphology and magnetic behavior as a function of the alloy composition with minimal oxidation. For alloys having low (10%-30%) Fe content the single face-centered cubic (FCC) FeNi3 phase was formed with nanorods aligned in the (1 1 1) crystalline direction on the cluster surface. This highly anisotropic morphology gradually disappeared as the Fe content was raised to 40%-70% with the alloy structure possessing a mixture of FCC FeNi3 and body-centered cubic (BCC) Fe7Ni3. The FCC phase was entirely replaced by the BCC structure upon further increase the Fe content to 80%-90%. The substitution of Ni by Fe in the crystals and the dominance of the BCC phase over the FCC structure gave rise to enhanced magnetization. By contrast, the coercive field decreased as a function of increasing Fe because of the reduction in shape anisotropy and the rise of saturation magnetization.

A discrete mechanics approach to dislocation dynamics in BCC crystals

NASA Astrophysics Data System (ADS)

Ramasubramaniam, A.; Ariza, M. P.; Ortiz, M.

2007-03-01

A discrete mechanics approach to modeling the dynamics of dislocations in BCC single crystals is presented. Ideas are borrowed from discrete differential calculus and algebraic topology and suitably adapted to crystal lattices. In particular, the extension of a crystal lattice to a CW complex allows for convenient manipulation of forms and fields defined over the crystal. Dislocations are treated within the theory as energy-minimizing structures that lead to locally lattice-invariant but globally incompatible eigendeformations. The discrete nature of the theory eliminates the need for regularization of the core singularity and inherently allows for dislocation reactions and complicated topological transitions. The quantization of slip to integer multiples of the Burgers' vector leads to a large integer optimization problem. A novel approach to solving this NP-hard problem based on considerations of metastability is proposed. A numerical example that applies the method to study the emanation of dislocation loops from a point source of dilatation in a large BCC crystal is presented. The structure and energetics of BCC screw dislocation cores, as obtained via the present formulation, are also considered and shown to be in good agreement with available atomistic studies. The method thus provides a realistic avenue for mesoscale simulations of dislocation based crystal plasticity with fully atomistic resolution.

Family history of skin cancer is associated with early-onset basal cell carcinoma independent of MC1R genotype.

PubMed

Berlin, Nicholas L; Cartmel, Brenda; Leffell, David J; Bale, Allen E; Mayne, Susan T; Ferrucci, Leah M

2015-12-01

As a marker of genetic susceptibility and shared lifestyle characteristics, family history of cancer is often used to evaluate an individual's risk for developing a particular malignancy. With comprehensive data on pigment characteristics, lifestyle factors, and melanocortin 1 receptor (MC1R) gene sequence, we sought to clarify the role of family history of skin cancer in early-onset basal cell carcinoma (BCC). Early onset BCC cases (n=376) and controls with benign skin conditions (n=383) under age 40 were identified through Yale dermatopathology. Self-report data on family history of skin cancer (melanoma and non-melanoma skin cancer), including age of onset in relatives, was available from a structured interview. Participants also provided saliva samples for sequencing of MC1R. A family history of skin cancer was associated with an increased risk of early-onset BCC (OR 2.49, 95% CI 1.80-3.45). In multivariate models, family history remained a strong risk factor for early-onset BCC after adjustment for pigment characteristics, UV exposure, and MC1R genotype (OR 2.41, 95% CI 1.74-3.35). Risk for BCC varied based upon the type and age of onset of skin cancer among affected relatives; individuals with a first-degree relative diagnosed with skin cancer prior to age 50 were at highest risk for BCC (OR 4.79, 95% CI 2.90-7.90). Even after taking into account potential confounding effects of MC1R genotype and various lifestyle factors that close relatives may share, family history of skin cancer remained strongly associated with early-onset BCC. Copyright © 2015. Published by Elsevier Ltd.

Investigation of radiation damage tolerance in interface-containing metallic nano structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Greer, Julia R.

The proposed work seeks to conduct a basic study by applying experimental and computational methods to obtain quantitative influence of helium sink strength and proximity on He bubble nucleation and growth in He-irradiated nano-scale metallic structures, and the ensuing deformation mechanisms and mechanical properties. We utilized a combination of nano-scale in-situ tension and compression experiments on low-energy He-irradiated samples combined with site-specific microstructural characterization and modeling efforts. We also investigated the mechanical deformation of nano-architected materials, i.e. nanolattices which are comprised of 3-dimensional interwoven networks of hollow tubes, with the wall thickness in the nanometer range. This systematic approach willmore » provide us with critical information for identifying key factors that govern He bubble nucleation and growth upon irradiation as a function of both sink strength and sink proximity through an experimentally-confirmed physical understanding. As an outgrowth of these efforts, we performed irradiations with self-ions (Ni 2+) on Ni-Al-Zr metallic glass nanolattices to assess their resilience against radiation damage rather than He-ion implantation. We focused our attention on studying individual bcc/fcc interfaces within a single nano structure (nano-pillar or a hollow tube): a single Fe (bcc)-Cu (fcc) boundary per pillar oriented perpendicular to the pillar axes, as well as pure bcc and fcc nano structures. Additional interfaces of interest include bcc/bcc and metal/metallic glass all within a single nano-structure volume. The model material systems are: (1) pure single crystalline Fe and Cu, (2) a single Fe (bcc)-Cu (fcc) boundary per nano structure (3) a single metal–metallic glass, all oriented non-parallel to the loading direction so that their fracture strength can be tested. A nano-fabrication approach, which involves e-beam lithography and templated electroplating, as well as two-photon lithography, was utilized, which enabled precise control of the initial microstructure control. Experimentally determined stress-strain relationships were enhanced by in-situ SEM observations coupled with TEM microstructural characterization of the same samples before and after deformation (irradiated and as-fabricated) and atomistic (MD) modeling. A comprehensive suite of experiments was conducted to quantitatively assess the key parameters for He bubble nucleation and growth by independently varying the sink strength, sink proximity, and He implantation temperature and dose. The implantations were conducted at Sandia and Los Alamos National Labs (CINT). Nano structuress containing He-enriched interfaces and irradiation-damaged microstructure were tested under uniaxial tension to assess embrittlement, resulting boundary strength, and deformation mechanisms. Results of this work helped identify which types of interfaces are particularly resilient against radiation damage.« less

The fcc - bcc structural transition: I. A band theoretical study for Li, K, Rb, Ca, Sr, and the transition metals Ti and V

NASA Astrophysics Data System (ADS)

Sliwko, V. L.; Mohn, P.; Schwarz, K.; Blaha, P.

1996-02-01

Employing a high-precision band structure method (FP LAPW - full potential linearized augmented plane wave) we calculate the total energy variation along the tetragonal distortion path connecting the body centred cubic (bcc) and the face centred cubic (fcc) structures. The total energy along this Bain transformation is calculated, varying c/a and volume, providing a first-principles energy surface which has two minima as a function of c/a. These are shallow and occur for the sp metals at the two cubic structures, while Ti (V) has a minimum at fcc (bcc) but a saddle point (i.e. a minimum in volume and a maximum with respect to c/a) at the other cubic structure. These features can be analysed in terms of an interplay between the Madelung contribution and the band energies. Our total energy results allow us to calculate the elastic constants 0953-8984/8/7/006/img1 and 0953-8984/8/7/006/img2 and to study the influence of pressure on the phase stability. These energy surfaces will be used in part II of this paper to investigate finite-temperature effects by mapping them to a Landau - Ginzburg expansion.

The effect of relativity on stability of Copernicium phases, their electronic structure and mechanical properties

NASA Astrophysics Data System (ADS)

Čenčariková, Hana; Legut, Dominik

2018-05-01

The phase stability of the various crystalline structures of the super-heavy element Copernicium was determined based on the first-principles calculations with different levels of the relativistic effects. We utilized the Darwin term, mass-velocity, and spin-orbit interaction with the single electron framework of the density functional theory while treating the exchange and correlation effects using local density approximations. It is found that the spin-orbit coupling is the key component to stabilize the body-centered cubic (bcc) structure over the hexagonal closed packed (hcp) structure, which is in accord with Sol. Stat. Comm. 152 (2012) 530, but in contrast to Atta-Fynn and Ray (2015) [11], Gaston et al. (2007) [10], Papaconstantopoulos (2015) [9]. It seems that the main role here is the correct description of the semi-core relativistic 6p1/2 orbitals. The all other investigated structures, i.e. face-centered cubic (fcc) , simple cubic (sc) as well as rhombohedral (rh) structures are higher in energy. The criteria of mechanical stability were investigated based on the calculated elastic constants, identifying the phase instability of fcc and rh structures, but surprisingly confirm the stability of the energetically higher sc structure. In addition, the pressure-induced structural transition between two stable sc and bcc phases has been detected. The ground-state bcc structure exhibits the highest elastic anisotropy from single elements of the Periodic table. At last, we support the experimental findings that Copernicium is a metal.

Formation of soft magnetic high entropy amorphous alloys composites containing in situ solid solution phase

NASA Astrophysics Data System (ADS)

Wei, Ran; Sun, Huan; Chen, Chen; Tao, Juan; Li, Fushan

2018-03-01

Fe-Co-Ni-Si-B high entropy amorphous alloys composites (HEAACs), which containing high entropy solid solution phase in amorphous matrix, show good soft magnetic properties and bending ductility even in optimal annealed state, were successfully developed by melt spinning method. The crystallization phase of the HEAACs is solid solution phase with body centered cubic (BCC) structure instead of brittle intermetallic phase. In addition, the BCC phase can transformed into face centered cubic (FCC) phase with temperature rise. Accordingly, Fe-Co-Ni-Si-B high entropy alloys (HEAs) with FCC structure and a small amount of BCC phase was prepared by copper mold casting method. The HEAs exhibit high yield strength (about 1200 MPa) and good plastic strain (about 18%). Meanwhile, soft magnetic characteristics of the HEAs are largely reserved from HEAACs. This work provides a new strategy to overcome the annealing induced brittleness of amorphous alloys and design new advanced materials with excellent comprehensive properties.

Structural transformations in austenitic stainless steel induced by deuterium implantation: irradiation at 100 K

NASA Astrophysics Data System (ADS)

Morozov, Oleksandr; Zhurba, Volodymyr; Neklyudov, Ivan; Mats, Oleksandr; Rud, Aleksandr; Chernyak, Nikolay; Progolaieva, Viktoria

2015-03-01

Deuterium thermal desorption spectra were investigated on the samples of austenitic stainless steel 18Cr10NiTi preimplanted at 100 K with deuterium ions in the dose range from 3 × 1015 to 5 × 1018 D/cm2. The kinetics of structural transformation development in the implantation steel layer was traced from deuterium thermodesorption spectra as a function of implanted deuterium concentration. At saturation of austenitic stainless steel 18Cr10NiTi with deuterium by means of ion implantation, structural-phase changes take place, depending on the dose of implanted deuterium. The maximum attainable concentration of deuterium in steel is C = 1 (at.D/at.met. = 1/1). The increase in the implanted dose of deuterium is accompanied by the increase in the retained deuterium content, and as soon as the deuterium concentration attains C ≈ 0.5 the process of shear martensitic structural transformation in steel takes place. It includes the formation of bands, body-centered cubic (bcc) crystal structure, and the ferromagnetic phase. Upon reaching the deuterium concentration C > 0.5, the presence of these molecules causes shear martensitic structural transformations in the steel, which include the formation of characteristic bands, bcc crystal structure, and the ferromagnetic phase. At C ≥ 0.5, two hydride phases are formed in the steel, the decay temperatures of which are 240 and 275 K. The hydride phases are formed in the bcc structure resulting from the martensitic structural transformation in steel.

22 CFR 41.33 - Nonresident alien Canadian border crossing identification card (BCC).

Code of Federal Regulations, 2010 CFR

2010-04-01

... identification card (BCC). 41.33 Section 41.33 Foreign Relations DEPARTMENT OF STATE VISAS VISAS: DOCUMENTATION... BCC or the BCC portion of a Canadian B-1/B-2 Visa/BCC issued to a permanent resident of Canada... officer may revoke a BCC or a B-1/B-2 Visa/BCC issued in Canada at any time under the provisions of § 41...

Superficial basal cell carcinoma: A comparison of superficial only subtype with superficial combined with other subtypes by age, sex and anatomic site in 3150 cases.

PubMed

Pyne, John H; Myint, Esther; Barr, Elizabeth M; Clark, Simon P; David, Michael; Na, Renua; Hou, Ruihang

2017-08-01

Basal cell carcinoma (BCC) may present as superficial subtype alone (sBCC) or superficial combined with other subtypes. The objective of this study was to compare sBCC without or with other BCC subtypes by age, sex and anatomic site. We retrospectively collected superficial BCC with the above characteristics from an Australian center during 2009 to 2014. We recorded 1528 sBCC and 1622 superficial BCC combined with other BCC subtype cases. Males numbered 2007 and females 1140. On males, head sites (forehead, cheek, nose and ear combined) compared to limb plus trunk sites displayed a higher incidence of superficial BCC combined with either nodular and or aggressive BCC subtypes (OR 13.15 CI 95% 8.9-19.5 P < .0001). On females a similar comparison also found a higher incidence of superficial BCC combined with solid subtype BCC on head sites compared to trunk and limb sites (OR 9.66 CI 95% 5.8-16.1 P < .0001). Superficial BCC alone is more likely on younger females on trunk and limb sites. Small partial biopsies reported as sBCC may miss other BCC subtypes present with higher risk on facial sites for males and females. Males had smaller proportions of superficial only subtype BCC on facial and ear sites compared to females. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Magneto-structural transformations via a solid-state nudged elastic band method: Application to iron under pressure

DOE PAGES

Zarkevich, N. A.; Johnson, D. D.

2015-08-14

We extend the solid-state nudged elastic band method to handle a non-conserved order parameter, in particular, magnetization, that couples to volume and leads to many observed effects in magnetic systems. We apply this formalism to the well-studied magneto-volume collapse during the pressure-induced transformation in iron—from ferromagnetic body-centered cubic (bcc) austenite to hexagonal close-packed (hcp) martensite. We also find a bcc-hcp equilibrium coexistence pressure of 8.4 GPa, with the transition-state enthalpy of 156 meV/Fe at this pressure. A discontinuity in magnetization and coherent stress occurs at the transition state, which has a form of a cusp on the potential-energy surface (yetmore » all the atomic and cell degrees of freedom are continuous); the calculated pressure jump of 25 GPa is related to the observed 25 GPa spread in measured coexistence pressures arising from martensitic and coherency stresses in samples. Furthermore, our results agree with experiments, but necessarily differ from those arising from drag and restricted parametrization methods having improperly constrained or uncontrolled degrees of freedom.« less

First-principles study of metallic iron interfaces

NASA Astrophysics Data System (ADS)

Hung, A.; Yarovsky, I.; Muscat, J.; Russo, S.; Snook, I.; Watts, R. O.

2002-04-01

Adhesion between clean, bulk-terminated bcc Fe(1 0 0) and Fe(1 1 0) matched and mismatched surfaces was simulated within the theoretical framework of the density functional theory. The generalized-gradient spin approximation exchange-correlation functional was used in conjunction with a plane wave-ultrasoft pseudopotential representation. The structure and properties of bulk bcc Fe were calculated in order to establish the reliability of the methodology employed, as well as to determine suitably converged values of computational parameters to be used in subsequent surface calculations. Interfaces were modelled using a single supercell approach, with the interfacial separation distance manipulated by the size of vacuum separation between vertically adjacent surface cells. The adhesive energies at discrete interfacial separations were calculated for each interface and the resulting data fitted to the universal binding energy relation (UBER) of Rose et al. [Phys. Rev. Lett. 47 (1981) 675]. An interpretation of the values of the fitted UBER parameters for the four Fe interfaces studied is given. In addition, a discussion on the validity of the employed computational methodology is presented.

Long-term safety and efficacy of vismodegib in patients with advanced basal cell carcinoma: final update of the pivotal ERIVANCE BCC study.

PubMed

Sekulic, Aleksandar; Migden, Michael R; Basset-Seguin, Nicole; Garbe, Claus; Gesierich, Anja; Lao, Christopher D; Miller, Chris; Mortier, Laurent; Murrell, Dedee F; Hamid, Omid; Quevedo, Jorge F; Hou, Jeannie; McKenna, Edward; Dimier, Natalie; Williams, Sarah; Schadendorf, Dirk; Hauschild, Axel

2017-05-16

In the primary analysis of the ERIVANCE BCC trial, vismodegib, the first US Food and Drug Administration-approved Hedgehog pathway inhibitor, showed objective response rates (ORRs) by independent review facility (IRF) of 30% and 43% in metastatic basal cell carcinoma (mBCC) and locally advanced BCC (laBCC), respectively. ORRs by investigator review were 45% (mBCC) and 60% (laBCC). Herein, we present long-term safety and final investigator-assessed efficacy results in patients with mBCC or laBCC. One hundred four patients with measurable advanced BCC received oral vismodegib 150 mg once daily until disease progression or intolerable toxicity. The primary end point was IRF-assessed ORR. Secondary end points included ORR, duration of response (DOR), progression-free survival, overall survival (OS), and safety. At data cutoff (39 months after completion of accrual), 8 patients were receiving the study drug (69 patients in survival follow-up). Investigator-assessed ORR was 48.5% in the mBCC group (all partial responses) and 60.3% in the laBCC group (20 patients had complete response and 18 patients had partial response). ORRs were comparable across patient subgroups, including aggressive histologic subtypes (eg, infiltrative BCC). Median DOR was 14.8 months (mBCC) and 26.2 months (laBCC). Median OS was 33.4 months in the mBCC cohort and not estimable in the laBCC cohort. Adverse events remained consistent with clinical experience. Thirty-three deaths (31.7%) were reported; none were related to vismodegib. This long-term update of the ERIVANCE BCC trial demonstrated durability of response, efficacy across patient subgroups, and manageable long-term safety of vismodegib in patients with advanced BCC. This study was registered prospectively with Clinicaltrials.gov , number NCT00833417 on January 30, 2009.

Engineering and characterizing nanoscale multilayered structures for magnetic tunnel junctions

NASA Astrophysics Data System (ADS)

Yang, J. Joshua

Magnetic tunnel junction (MTJ) has generated considerable attention due to its potential applications in improved magnetic sensors, read heads in HDDs and nonvolatile RAM. The materials issues play a crucial role in the performance of MTJs. In the work described in this thesis, we have engineered some interesting nanoscale multilayered structures mainly via thermodynamics considerations for MTJs. The insulator is usually an ultra-thin (<2nm) oxide, formed by oxidizing a pre-deposited metal, such as Al etc. We have developed novel fabrication approaches for obtaining clean and smooth interfaces between the insulator and the ferromagnets. These approaches include selectively oxidizing the pre-deposited tunnel barrier precursor metal, amorphizing the tunnel barrier precursor metal by alloying it with other elements, and in-situ annealing the bottom ferromagnetic layer. About 72% tunneling magnetoresistance (TMR) has been achieved at room temperature with AlOx and CoFe based MTJs. We have made a systemic study of the TMR vs. the Co1-xFe x electrode composition for AlOx based MTJs. A significant variation of TMR with Fe concentration has been observed. It is well known that the crystal structure of Co1-xFex changes from fcc to bcc with increasing Fe concentration. The concomitant composition change cast doubts on the role played by the crystal structure of the Co1-x Fex electrode on the TMR. By introducing different strains to an epitaxial Co1-xFex layer, we were able to fix its composition but alter its crystalline structure from fcc to bcc and found that the bcc structure resulted in much higher TMR values than found for the fcc structure. This is one of the few direct experimental confirmatory results showing the role of the FM electronic structure on the MTJ properties. Using Ag as a template, different 3d ferromagnets have been epitaxially grown on the Si substrate with hcp, fcc and bcc crystalline structures, respectively. By combining the selective oxidation method with the epitaxial growth technique, we have successfully created a single-crystal-like layer on top of an amorphous layer, which may have broad applications in thin film devices including MTJs.

Burden and treatment patterns of advanced basal cell carcinoma among commercially insured patients in a United States database from 2010 to 2014.

PubMed

Migden, Michael; Xie, Jipan; Wei, Jin; Tang, Wenxi; Herrera, Vivian; Palmer, Jacqueline B

2017-07-01

The burden of advanced basal cell carcinoma (aBCC) is not fully understood. To compare BCC disease burden and treatment patterns for aBCC with those for non-aBCC. A retrospective, insurance claims-based study design was used. Adults with ≥2 claims associated with a BCC diagnosis (ICD-9-CM 173.x1) separated by ≥30 days on or after October 1, 2011, were classified as aBCC or non-aBCC by using an algorithm based on metastasis diagnosis, radiation therapy use, and medical oncologist/other specialist use. Non-aBCC and aBCC patients were matched 1:1 on the basis of age, sex, and region, and assigned the same index date (date of first qualifying diagnosis or event). Comparisons were made using Wilcoxon signed-rank (continuous variables) and McNemar's (categorical variables) tests. In total, 847 matched aBCC/non-aBCC patient pairs were selected (mean age 75 years; 57% men; locally advanced BCC, n = 826; metastatic BCC, n = 21). During the 12-month study period following the index date, aBCC patients had a significantly higher mean Charlson Comorbidity Index (P = .0023), significantly higher mean numbers of outpatient/dermatologist/medical oncologist visits (all P < .0001), and significantly higher mean total/medical/inpatient/outpatient/BCC treatment costs (all P < .05). This study only included information from a database on commercial insurance and Medicare claims. The algorithm criteria might have restricted patient numbers; data were not fully reflective of targeted therapy era. aBCC patients had a higher disease burden than non-aBCC patients. Cost differences were largely driven by higher BCC treatment costs, specifically radiation therapy. Copyright © 2017 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

Short-range order clustering in BCC Fe-Mn alloys induced by severe plastic deformation

NASA Astrophysics Data System (ADS)

Shabashov, V. A.; Kozlov, K. A.; Sagaradze, V. V.; Nikolaev, A. L.; Lyashkov, K. A.; Semyonkin, V. A.; Voronin, V. I.

2018-03-01

The effect of severe plastic deformation, namely, high-pressure torsion (HPT) at different temperatures and ball milling (BM) at different time intervals, has been investigated by means of Mössbauer spectroscopy in Fe100-xMnx (x = 4.1, 6.8, 9) alloys. Deformation affects the short-range clustering (SRC) in BCC lattice. Two processes occur: destruction of SRC by moving dislocations and enhancement of the SRC by migration of non-equilibrium defects. Destruction of SRC prevails during HPT at 80-293 K; whereas enhancement of SRC dominates at 473-573 K. BM starts enhancing the SRC formation at as low as 293 K due to local heating at impacts. The efficiency of HPT in terms of enhancing SRC increases with increasing temperature. The authors suppose that at low temperatures, a significant fraction of vacancies are excluded from enhancing SRC because of formation of mobile bi- and tri-vacancies having low efficiency of enhancing SRC as compared to that of mono vacancies. Milling of BCC Fe100-xMnx alloys stabilises the BCC phase with respect to α → γ transition at subsequent isothermal annealing because of a high degree of work hardening and formation of composition inhomogeneity.

Usefulness of Photodynamic Therapy as a Possible Therapeutic Alternative in the Treatment of Basal Cell Carcinoma

PubMed Central

Savoia, Paola; Deboli, Tommaso; Previgliano, Alberto; Broganelli, Paolo

2015-01-01

Basal cell carcinoma (BCC) is the most common cancer in individuals with fair skin type (I–II) and steadily increasing in incidence (70% of skin malignancy). It is locally invasive but metastasis is usually very rare, with an estimated incidence of 0.0028%–0.55%. Conventional therapy is surgery, especially for the H region of the face and infiltrative lesions; in case of inoperable tumors, radiotherapy is a valid option. Recently, topical photodynamic therapy (PDT) has become an effective treatment in the management of superficial and small nodular BCC. PDT is a minimally invasive procedure that involves the administration of a photo-sensibilizing agent followed by irradiation at a pre-defined wavelength; this determines the creation of reactive oxygen species that specifically destroy target cells. The only major side effect is pain, reported by some patients during the irradiation. The high cure rate and excellent cosmetic outcome requires considering this possibility for the management of patients with both sporadic and hereditary BCC. In this article, an extensive review of the recent literature was made, in order to clarify the role of PDT as a possible alternative therapeutic option in the treatment of BCC. PMID:26426005

Applications of conformal field theory to problems in 2D percolation

NASA Astrophysics Data System (ADS)

Simmons, Jacob Joseph Harris

This thesis explores critical two-dimensional percolation in bounded regions in the continuum limit. The main method which we employ is conformal field theory (CFT). Our specific results follow from the null-vector structure of the c = 0 CFT that applies to critical two-dimensional percolation. We also make use of the duality symmetry obeyed at the percolation point, and the fact that percolation may be understood as the q-state Potts model in the limit q → 1. Our first results describe the correlations between points in the bulk and boundary intervals or points, i.e. the probability that the various points or intervals are in the same percolation cluster. These quantities correspond to order-parameter profiles under the given conditions, or cluster connection probabilities. We consider two specific cases: an anchoring interval, and two anchoring points. We derive results for these and related geometries using the CFT null-vectors for the corresponding boundary condition changing (bcc) operators. In addition, we exhibit several exact relationships between these probabilities. These relations between the various bulk-boundary connection probabilities involve parameters of the CFT called operator product expansion (OPE) coefficients. We then compute several of these OPE coefficients, including those arising in our new probability relations. Beginning with the familiar CFT operator φ1,2, which corresponds to a free-fixed spin boundary change in the q-state Potts model, we then develop physical interpretations of the bcc operators. We argue that, when properly normalized, higher-order bcc operators correspond to successive fusions of multiple φ1,2, operators. Finally, by identifying the derivative of φ1,2 with the operator φ1,4, we derive several new quantities called first crossing densities. These new results are then combined and integrated to obtain the three previously known crossing quantities in a rectangle: the probability of a horizontal crossing cluster, the probability of a cluster crossing both horizontally and vertically, and the expected number of horizontal crossing clusters. These three results were known to be solutions to a certain fifth-order differential equation, but until now no physically meaningful explanation had appeared. This differential equation arises naturally in our derivation.

Coexistence of a metastable double hcp phase in bcc-fcc structure transition of Te under high pressure

NASA Astrophysics Data System (ADS)

Akahama, Yuichi; Okawa, Naoki; Sugimoto, Toshiyuki; Fujihisa, Hiroshi; Hirao, Naoshisa; Ohishi, Yasuo

2018-02-01

The structural phase transitions of tellurium (Te) are investigated at pressures of up to 330 GPa at 298 K using an X-ray powder diffraction technique. In the experiments, it was found that the high-pressure bcc phase (Te-V) transitioned to the fcc phase (Te-VI) at 99 GPa, although a double hcp phase (dhcp) coexisted with the fcc phase. As the pressure was increased and decreased, the dhcp phase vanished at 255 and 100 GPa, respectively. These results suggest that the dhcp phase is metastable at 298 K and the structure of the highest-pressure phase of Te is fcc. The present results provide important information regarding the high-pressure behavior of group-16 elements.

CD200-expressing human basal cell carcinoma cells initiate tumor growth.

PubMed

Colmont, Chantal S; Benketah, Antisar; Reed, Simon H; Hawk, Nga V; Telford, William G; Ohyama, Manabu; Udey, Mark C; Yee, Carole L; Vogel, Jonathan C; Patel, Girish K

2013-01-22

Smoothened antagonists directly target the genetic basis of human basal cell carcinoma (BCC), the most common of all cancers. These drugs inhibit BCC growth, but they are not curative. Although BCC cells are monomorphic, immunofluorescence microscopy reveals a complex hierarchical pattern of growth with inward differentiation along hair follicle lineages. Most BCC cells express the transcription factor KLF4 and are committed to terminal differentiation. A small CD200(+) CD45(-) BCC subpopulation that represents 1.63 ± 1.11% of all BCC cells resides in small clusters at the tumor periphery. By using reproducible in vivo xenograft growth assays, we determined that tumor initiating cell frequencies approximate one per 1.5 million unsorted BCC cells. The CD200(+) CD45(-) BCC subpopulation recreated BCC tumor growth in vivo with typical histological architecture and expression of sonic hedgehog-regulated genes. Reproducible in vivo BCC growth was achieved with as few as 10,000 CD200(+) CD45(-) cells, representing ~1,500-fold enrichment. CD200(-) CD45(-) BCC cells were unable to form tumors. These findings establish a platform to study the effects of Smoothened antagonists on BCC tumor initiating cell and also suggest that currently available anti-CD200 therapy be considered, either as monotherapy or an adjunct to Smoothened antagonists, in the treatment of inoperable BCC.

Super heavy element Copernicium: Cohesive and electronic properties revisited

NASA Astrophysics Data System (ADS)

Gyanchandani, Jyoti; Mishra, Vinayak; Dey, G. K.; Sikka, S. K.

2018-01-01

First principles scalar relativistic (SR) calculations with and without including the spin orbit (SO) interactions have been performed for solid Copernicium (Cn) to determine its ground state equilibrium structure, volume, bulk modulus, pressure derivative of the bulk modulus, density of states and band structure. Both SR and SR+SO calculations have been performed with 6p levels treated as part of core electrons and also as part of valence electrons. These calculations have been performed for the rhombohedral, BCT, FCC, HCP, BCC and SC structures. Results have been compared with the results for Hg which is lighter homologue of Cn in the periodic table. We find hcp to be the stable crystal structure at SR level of theory and also at SR+SO level of theory when the 6p electrons are treated as part of core electrons. With 6p as part of valence electrons, SR+SO level of computations, however, yield bcc structure to be the most stable structure. Equilibrium volume (V0) of the most stable crystal structure at SR level of theory viz. hcp structure is 188.66 a.u.3whereas its value for the bcc structure, the equilibrium ground state structure at SR+SO level of theory is 165.71 a.u.3 i.e a large change due to relativistic effects is seen. The density of states at Fermi level is much smaller in Cn than in Hg, making it a poorer metal than mercury. In addition the cohesive energy of Cn is computed to be almost two times that of Hg for SR+SO case.

Effects of temperature and void on the dynamics and microstructure of structural transition in single crystal iron

NASA Astrophysics Data System (ADS)

Shao, Jian-Li; Wang, Pei; Zhang, Feng-Guo; He, An-Min

2018-06-01

With classic molecular dynamics simulations, we investigate the effects of temperature and void on the bcc to hcp/fcc structural transition in single crystal iron driven by 1D ([0 0 1]) and 3D (uniform) compressions. The results show that the pressure threshold does not reduce monotonously with temperature. The pressure threshold firstly increases and then decreases in the range of 60–360 K under 1D compression, while the variation trend is just opposite under 3D compression. As expected, the initial defect may lower the pressure threshold via heterogenous nucleation. This effect is found to be more distinct at lower temperature, and the heterogenous nucleation mainly results in hcp structure. Under the condition of strain constraint, the products of structural transition will respectively form flaky hcp twin structure ((1 0 0) or (0 1 0)) and lamellar structure ({1 1 0}) of mixed phases under 1D and 3D compressions. During the structural transition, we find the shear stress (1D compression) of hcp phase is always lower than that of bcc phase. The cold energy calculations indicate that the hcp phase is the most stable under high pressure. However, we observe the evident metastable state of bcc phase, whose energy will be much higher than both hcp and fcc phases, and then provides the possibility for the occurrence of fcc nucleation.

Tuning the Magnetic and Electronic Properties of Iron(x )Silicon(1-x) Thin Films for Spintronics

NASA Astrophysics Data System (ADS)

Karel, Julie Elizabeth

This dissertation investigated the magnetic and electronic properties of a potentially better alternative: off-stoichimetry, bcc-like FexSi 1-x thin films (0.43800 K) and theoretically predicted high spin polarization (100%). However, little work has been done on off-stoichiometry FexSi1-x thin films (0.43

Chaotic Fluid Mixing in Crystalline Sphere Arrays

NASA Astrophysics Data System (ADS)

Turuban, R.; Lester, D. R.; Le Borgne, T.; Méheust, Y.

2017-12-01

We study the Lagrangian dynamics of steady 3D Stokes flow over simple cubic (SC) and body-centered cubic (BCC) lattices of close-packed spheres, and uncover the mechanisms governing chaotic mixing. Due to the cusp-shaped sphere contacts, the topology of the skin friction field is fundamentally different to that of continuous (non-granular) media (e.g. open pore networks), with significant implications for fluid mixing. Weak symmetry breaking of the flow orientation with respect to the lattice symmetries imparts a transition from regular to strong chaotic mixing in the BCC lattice, whereas the SC lattice only exhibits weak mixing. Whilst the SC and BCC lattices share the same symmetry point group, these differences are explained in terms of their space groups, and we find that a glide symmetry of the BCC lattice generates chaotic mixing. These insight are used to develop accurate predictions of the Lyapunov exponent distribution over the parameter space of mean flow orientation, and point to a general theory of mixing and dispersion based upon the inherent symmetries of arbitrary crystalline structures.

Design of refractory high-entropy alloys

DOE PAGES

Gao, M. C.; Carney, C. S.; Dogan, O. N.; ...

2015-09-15

Here, this report presents a design methodology for refractory high-entropy alloys with a body-centered cubic (bcc) structure using select empirical parameters (i.e., enthalpy of mixing, atomic size difference, Ω-parameter, and electronegativity difference) and CALPHAD approach. Sixteen alloys in equimolar compositions ranging from quinary to ennead systems were designed with experimental verification studies performed on two alloys using x-ray diffraction, energy-dispersive spectroscopy, and scanning electron microscopy. Two bcc phases were identified in the as-cast HfMoNbTaTiVZr, whereas multiple phases formed in the as-cast HfMoNbTaTiVWZr. Observed elemental segregation in the alloys qualitatively agrees with CALPHAD prediction. Comparisons of the thermodynamic mixing properties formore » liquid and bcc phases using the Miedema model and CALPHAD are presented. This study demonstrates that CALPHAD is more effective in predicting HEA formation than empirical parameters, and new single bcc HEAs are suggested: HfMoNbTiZr, HfMoTaTiZr, NbTaTiVZr, HfMoNbTaTiZr, HfMoTaTiVZr, and MoNbTaTiVZr.« less

Boron cage compound materials and composites for shielding and absorbing neutrons

DOEpatents

Bowen, III, Daniel E; Eastwood, Eric A

2014-03-04

Boron cage compound-containing materials for shielding and absorbing neutrons. The materials include BCC-containing composites and compounds. BCC-containing compounds comprise a host polymer and a BCC attached thereto. BCC-containing composites comprise a mixture of a polymer matrix and a BCC filler. The BCC-containing materials can be used to form numerous articles of manufacture for shielding and absorbing neutrons.

Structural transformations in austenitic stainless steel induced by deuterium implantation: irradiation at 100 K.

PubMed

Morozov, Oleksandr; Zhurba, Volodymyr; Neklyudov, Ivan; Mats, Oleksandr; Rud, Aleksandr; Chernyak, Nikolay; Progolaieva, Viktoria

2015-01-01

Deuterium thermal desorption spectra were investigated on the samples of austenitic stainless steel 18Cr10NiTi preimplanted at 100 K with deuterium ions in the dose range from 3 × 10(15) to 5 × 10(18) D/cm(2). The kinetics of structural transformation development in the implantation steel layer was traced from deuterium thermodesorption spectra as a function of implanted deuterium concentration. At saturation of austenitic stainless steel 18Cr10NiTi with deuterium by means of ion implantation, structural-phase changes take place, depending on the dose of implanted deuterium. The maximum attainable concentration of deuterium in steel is C = 1 (at.D/at.met. = 1/1). The increase in the implanted dose of deuterium is accompanied by the increase in the retained deuterium content, and as soon as the deuterium concentration attains C ≈ 0.5 the process of shear martensitic structural transformation in steel takes place. It includes the formation of bands, body-centered cubic (bcc) crystal structure, and the ferromagnetic phase. Upon reaching the deuterium concentration C > 0.5, the presence of these molecules causes shear martensitic structural transformations in the steel, which include the formation of characteristic bands, bcc crystal structure, and the ferromagnetic phase. At C ≥ 0.5, two hydride phases are formed in the steel, the decay temperatures of which are 240 and 275 K. The hydride phases are formed in the bcc structure resulting from the martensitic structural transformation in steel.

Effect of Al content on structure and mechanical properties of the Al{sub x}CrNbTiVZr (x = 0; 0.25; 0.5; 1) high-entropy alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yurchenko, N.Yu.

2016-11-15

In present study, structure and mechanical properties of the Al{sub x}CrNbTiVZr (x = 0; 0.25; 0.5; 1) high-entropy alloys after arc melting and annealing at 1200 °C for 24 h are investigated. The CrNbTiVZr alloy is composed of body centered cubic (bcc) and C15 (face centered cubic) Laves phases while the Al{sub x}CrNbTiVZr (x = 0.25; 0.5; 1) alloys consist of bcc and two C14 (hexagonal close packed) Laves phases with different chemical compositions. Thermodynamic modeling predicts existence of two phases – bcc and C15 Laves phase and broadening of single bcc phase field due to Al addition. The densitymore » of the alloys decreases with the increase of Al content. The alloys are found to be extremely brittle at room temperature and 600 °C. The alloys have high strength at temperatures of 800–1000 °C. For example, yield strength at 800 °C increases from 440 MPa for the CrNbTiVZr alloy to 1250 MPa for the AlCrNbTiVZr alloy. The experimental phase composition of the Al{sub x}CrNbTiVZr alloys is compared with predicted equilibrium phases and the factors governing the transformation of C15 to C14 Laves phases due to Al addition to the CrNbTiVZr alloy analyzed. Specific properties of the alloys are compared with other high-entropy alloys and commercial Ni-based superalloys. - Highlights: •Al{sub x}CrNbTiVZr (x = 0; 0.25; 0.5; 1) alloys are arc melted and annealed at 1200 °C. •The CrNbTiVZr alloy has bcc and C15 Laves phases. •The Al-containing alloys are composed of bcc and two C14 Laves phases. •The alloys demonstrate high specific strength at temperatures of 800 °C and 1000 °C. •The strength of the alloys increases in proportion with increase of Al content.« less

Enhancing Entropy and Enthalpy Fluctuations to Drive Crystallization in Atomistic Simulations.

PubMed

Piaggi, Pablo M; Valsson, Omar; Parrinello, Michele

2017-07-07

Crystallization is a process of great practical relevance in which rare but crucial fluctuations lead to the formation of a solid phase starting from the liquid. As in all first order first transitions, there is an interplay between enthalpy and entropy. Based on this idea, in order to drive crystallization in molecular simulations, we introduce two collective variables, one enthalpic and the other entropic. Defined in this way, these collective variables do not prejudge the structure into which the system is going to crystallize. We show the usefulness of this approach by studying the cases of sodium and aluminum that crystallize in the bcc and fcc crystalline structures, respectively. Using these two generic collective variables, we perform variationally enhanced sampling and well tempered metadynamics simulations and find that the systems transform spontaneously and reversibly between the liquid and the solid phases.

Structural hierarchy as a key to complex phase selection in Al-Sm

NASA Astrophysics Data System (ADS)

Ye, Z.; Zhang, F.; Sun, Y.; Nguyen, M. C.; Zhou, S. H.; Zhou, L.; Meng, F.; Ott, R. T.; Park, E.; Besser, M. F.; Kramer, M. J.; Ding, Z. J.; Mendelev, M. I.; Wang, C. Z.; Napolitano, R. E.; Ho, K. M.

2017-10-01

Investigating the unknown structure of the complex cubic phase, previously observed to crystallize from melt-spun amorphous Al-10 at.% Sm alloy, we determine the structure in full site-occupancy detail, highlighting several critical structural features that govern the far-from-equilibrium phase selection pathway. Using an efficient genetic algorithm combining molecular dynamics, density functional theory, and x-ray diffraction, the structure is clearly identified as body-centered cubic I m 3 ¯m (No. 229) with ˜140 atoms per cubic unit cell and a lattice parameter of 1.4 nm. The complex structure is further refined to elucidate the detailed site occupancy, revealing full Sm occupancy on 6b sites and split Sm/Al occupancy on 16f sites. Based on the refined site occupancy associated with the experimentally observed phase, we term this phase ɛ -A l60S m11 (bcc), corresponding to the limiting situation when all 16f sites are occupied by Sm. However, it should be recognized that the range of solubility enabled by split occupancy at Sm sites is an important feature in phase selection under experimental conditions, permitting an avenue for transition with little or no chemical partitioning. Our analysis shows that the ɛ -A l60S m11 (bcc) exhibits a "3-6-6-1" first-shell packing around Sm centers on 16f sites, the same dominant motif exhibited by the undercooled liquid. The coincident motif supports the notion that liquid/glass ordering at high undercooling may give rise to topological invariants between the noncrystalline and crystalline states that provide kinetic pathways to metastable phases that are not accessible during near-equilibrium processing.

Structural hierarchy as a key to complex phase selection in Al-Sm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ye, Z.; Zhang, F.; Sun, Y.

Investigating the unknown structure of the complex cubic phase, previously observed to crystallize from melt-spun amorphous Al–10 at.% Sm alloy, we determine the structure in full site-occupancy detail, highlighting several critical structural features that govern the far-from-equilibrium phase selection pathway. Using an efficient genetic algorithm combining molecular dynamics, density functional theory, and x-ray diffraction, the structure is clearly identified as body-centered cubic Im¯3m (No. 229) with ~140 atoms per cubic unit cell and a lattice parameter of 1.4 nm. The complex structure is further refined to elucidate the detailed site occupancy, revealing full Sm occupancy on 6b sites and splitmore » Sm/Al occupancy on 16f sites. Based on the refined site occupancy associated with the experimentally observed phase, we term this phase ε–Al 60Sm 11(bcc), corresponding to the limiting situation when all 16f sites are occupied by Sm. However, it should be recognized that the range of solubility enabled by split occupancy at Sm sites is an important feature in phase selection under experimental conditions, permitting an avenue for transition with little or no chemical partitioning. Our analysis shows that the ε–Al 60Sm 11(bcc) exhibits a “3-6-6-1” first-shell packing around Sm centers on 16f sites, the same dominant motif exhibited by the undercooled liquid. Here, the coincident motif supports the notion that liquid/glass ordering at high undercooling may give rise to topological invariants between the noncrystalline and crystalline states that provide kinetic pathways to metastable phases that are not accessible during near-equilibrium processing.« less

Structural hierarchy as a key to complex phase selection in Al-Sm

DOE PAGES

Ye, Z.; Zhang, F.; Sun, Y.; ...

2017-10-12

Investigating the unknown structure of the complex cubic phase, previously observed to crystallize from melt-spun amorphous Al–10 at.% Sm alloy, we determine the structure in full site-occupancy detail, highlighting several critical structural features that govern the far-from-equilibrium phase selection pathway. Using an efficient genetic algorithm combining molecular dynamics, density functional theory, and x-ray diffraction, the structure is clearly identified as body-centered cubic Im¯3m (No. 229) with ~140 atoms per cubic unit cell and a lattice parameter of 1.4 nm. The complex structure is further refined to elucidate the detailed site occupancy, revealing full Sm occupancy on 6b sites and splitmore » Sm/Al occupancy on 16f sites. Based on the refined site occupancy associated with the experimentally observed phase, we term this phase ε–Al 60Sm 11(bcc), corresponding to the limiting situation when all 16f sites are occupied by Sm. However, it should be recognized that the range of solubility enabled by split occupancy at Sm sites is an important feature in phase selection under experimental conditions, permitting an avenue for transition with little or no chemical partitioning. Our analysis shows that the ε–Al 60Sm 11(bcc) exhibits a “3-6-6-1” first-shell packing around Sm centers on 16f sites, the same dominant motif exhibited by the undercooled liquid. Here, the coincident motif supports the notion that liquid/glass ordering at high undercooling may give rise to topological invariants between the noncrystalline and crystalline states that provide kinetic pathways to metastable phases that are not accessible during near-equilibrium processing.« less

Anomalous enhancement of the lower critical field deep in the superconducting state of LaRu4As12

NASA Astrophysics Data System (ADS)

Juraszek, J.; Bochenek, Ł.; Wawryk, R.; Henkie, Z.; Konczykowski, M.; Cichorek, T.

2018-05-01

LaRu4As12 with the critical temperature Tc = 10.4 K displays several features which point at a non-singlet superconducting order parameter, although the bcc crystal structure of the filled skutterudites does not favour the emergence of multiple energy gaps. LaRu4As12 displays an unexpected enhancement of the lower critical field deep in superconducting state which can be attributed to the existence of two superconducting gaps. At T = 0.4 K, the local magnetization measurements were performed utilizing miniaturized Hall sensors.

Iron nanoparticles with tunable tetragonal structure and magnetic properties

NASA Astrophysics Data System (ADS)

Liu, Jinming; Schliep, Karl; He, Shi-Hai; Ma, Bin; Jing, Ying; Flannigan, David J.; Wang, Jian-Ping

2018-05-01

Body-centered cubic (bcc) Fe is known as a typical soft magnetic material with high-saturation magnetization (Ms) and low magnetocrystalline anisotropy. However, first-principles calculations demonstrate that body-centered tetragonal (bct) Fe has higher magnetocrystalline anisotropy than bcc Fe and comparable Ms. In this work, bct Fe nanoparticles (NPs) were successfully fabricated by a gas-phase condensation method for the first time. The bct Fe phase is confirmed by the x-ray diffraction pattern and diffraction images of transmission electron microscopy. An increased magnetocrystalline anisotropy of bct Fe, (2.65 ±0.67 ) ×1 05J /m3 [ (21.2 ±5.3 ) μ eV /atom ], is observed, which is around seven times higher than that of bcc Fe 4.8 ×1 04J /m3 (3.5 μ eV /atom ). The bct Fe NPs sample has coercivity of 3.22 ×1 05 A/m at 5 K and 1.0 4 ×1 05 A/m at 300 K, which are much higher than that of bcc Fe NPs. In addition, the saturation magnetization at 5 K is estimated to be (1.6 ±0.4 ) ×1 06 A/m (2.2 ±0.5 μB/atom ), comparable to that of bcc Fe 1.7 ×1 06 A/m (2.2 μB/atom ).

Boron diffusion in bcc-Fe studied by first-principles calculations

NASA Astrophysics Data System (ADS)

Xianglong, Li; Ping, Wu; Ruijie, Yang; Dan, Yan; Sen, Chen; Shiping, Zhang; Ning, Chen

2016-03-01

The diffusion mechanism of boron in bcc-Fe has been studied by first-principles calculations. The diffusion coefficients of the interstitial mechanism, the B-monovacancy complex mechanism, and the B-divacancy complex mechanism have been calculated. The calculated diffusion coefficient of the interstitial mechanism is D0 = 1.05 × 10-7 exp (-0.75 eV/kT) m2 · s-1, while the diffusion coefficients of the B-monovacancy and the B-divacancy complex mechanisms are D1 = 1.22 × 10-6 f1 exp (-2.27 eV/kT) m2 · s-1 and D2 ≈ 8.36 × 10-6 exp (-4.81 eV/kT) m2 · s-1, respectively. The results indicate that the dominant diffusion mechanism in bcc-Fe is the interstitial mechanism through an octahedral interstitial site instead of the complex mechanism. The calculated diffusion coefficient is in accordance with the reported experiment results measured in Fe-3%Si-B alloy (bcc structure). Since the non-equilibrium segregation of boron is based on the diffusion of the complexes as suggested by the theory, our calculation reasonably explains why the non-equilibrium segregation of boron is not observed in bcc-Fe in experiments. Project supported by the National Natural Science Foundation of China (Grant No. 51276016) and the National Basic Research Program of China (Grant No. 2012CB720406).

Influence of hydrogen on the stability of iron phases under pressure

NASA Astrophysics Data System (ADS)

Skorodumova, N. V.; Ahuja, R.; Johansson, B.

2004-04-01

The influence of hydrogen presence on the stability of iron phases (bcc, hcp, dhcp, fcc, simple cubic) in a wide pressure interval at 0 K has been studied by the first-principles projector augmented-wave (PAW) method. Hydrogen is shown to occupy different interstitial lattice positions depending on the type of structure and pressure. An introduction of hydrogen impurities (˜6 at. %) leads to a stabilization of the close-packed iron structures, shifting the calculated pressure of the bcc-hcp transition from ˜9 GPa for pure iron to 7 GPa for Fe (6 at. % H). This tendency is further enhanced in the iron hydride structures. The iron hydrides in the close-packed structures (hcp, dhcp, fcc) are essentially degenerate in energy and found to be most stable in the whole pressure range.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frolov, T.; Setyawan, W.; Kurtz, R. J.

Evolutionary grand-canonical search predicts novel grain boundary structures and multiple grain boundary phases in elemental body-centered cubic (bcc) metals represented by tungsten, tantalum and molybdenum.

Stoichiometry and tribological behavior of thick Ta(N) coatings produced by direct current magnetron sputtering (DCMS)

NASA Astrophysics Data System (ADS)

Guo, Xiaotong; Niu, Yunsong; Chen, Minghui; Sun, Wenyao; Zhu, Shenglong; Wang, Fuhui

2018-01-01

Thick Ta(N) coating of 51 μm has been successfully obtained by DCMS technology. Ta(N) is a kind of distorted Ta matrix, which is inter-soluble with N-defect lattice structure, forming the disabled bcc structure. From the XRD and XPS investigations, the composition of Ta(N) coating is consisted of bcc-Ta and bcc-TaN0.06, while that of Ta coating mainly contains β-Ta phase. It can be concluded from wear test, nanoindentation test and SEM observations, wear resistance of Ta(N) coating is much better than that of Ta coating, due to its high hardness, H/E, H3/E2 value and low COF value. The wear mechanism of Ta coating is the compound fatigue and abrasive wear, while that of Ta(N) coating is transformed into adhesive wear mechanism. The secondary adhesion of the plastic deformation for the Ta(N) coating can reinforce the coated surface, to improve the load-bearing and anti-wear capacities, and thus improve the wear resistance.

Grain boundaries in bcc-Fe: a density-functional theory and tight-binding study

NASA Astrophysics Data System (ADS)

Wang, Jingliang; Madsen, Georg K. H.; Drautz, Ralf

2018-02-01

Grain boundaries (GBs) have a significant influence on material properties. In the present paper, we calculate the energies of eleven low-Σ ({{Σ }}≤slant 13) symmetrical tilt GBs and two twist GBs in ferromagnetic bcc iron using first-principles density functional theory (DFT) calculations. The results demonstrate the importance of a sufficient sampling of initial rigid body translations in all three directions. We show that the relative GB energies can be explained by the miscoordination of atoms at the GB region. While the main features of the studied GB structures were captured by previous empirical interatomic potential calculations, it is shown that the absolute values of GB energies calculated were substantially underestimated. Based on DFT-calculated GB structures and energies, we construct a new d-band orthogonal tight-binding (TB) model for bcc iron. The TB model is validated by its predictive power on all the studied GBs. We apply the TB model to block boundaries in lath martensite and demonstrate that the experimentally observed GB character distribution can be explained from the viewpoint of interface energy.

Equation of state and high-pressure/high-temperature phase diagram of magnesium

NASA Astrophysics Data System (ADS)

Stinton, G. W.; MacLeod, S. G.; Cynn, H.; Errandonea, D.; Evans, W. J.; Proctor, J. E.; Meng, Y.; McMahon, M. I.

2014-10-01

The phase diagram of magnesium has been investigated to 211 GPa at 300 K, and to 105 GPa at 4500 K, by using a combination of x-ray diffraction and resistive and laser heating. The ambient pressure hcp structure is found to start transforming to the bcc structure at ˜45 GPa, with a large region of phase-coexistence that becomes smaller at higher temperatures. The bcc phase is stable to the highest pressures reached. The hcp-bcc phase boundary has been studied on both compression and decompression, and its slope is found to be negative and steeper than calculations have previously predicted. The laser-heating studies extend the melting curve of magnesium to 105 GPa and suggest that, at the highest pressures, the melting temperature increases more rapidly with pressure than previously reported. Finally, we observe some evidence of a new phase in the region of 10 GPa and 1200 K, where previous studies have reported a double-hexagonal-close-packed (dhcp) phase. However, the additional diffraction peaks we observe cannot be accounted for by the dhcp phase alone.

Interactions between coherent twin boundaries and phase transition of iron under dynamic loading and unloading

NASA Astrophysics Data System (ADS)

Wang, Kun; Chen, Jun; Zhang, Xueyang; Zhu, Wenjun

2017-09-01

Phase transitions and deformation twins are constantly reported in many BCC metals under high pressure, whose interactions are of fundamental importance to understand the strengthening mechanism of these metals under extreme conditions. However, the interactions between twins and phase transition in BCC metals remain largely unexplored. In this work, interactions between coherent twin boundaries and α ↔ ɛ phase transition of iron are investigated using both non-equilibrium molecular dynamics simulations and the nudged elastic band method. Mechanisms of both twin-assisted phase transition and reverse phase transition are studied, and orientation relationships between BCC and HCP phases are found to be ⟨"separators="|11 1 ¯ ⟩ B C C||⟨"separators="|1 ¯2 1 ¯ 0 ⟩ H C P and ⟨"separators="|1 1 ¯ 0 ⟩ B C C||⟨"separators="|0001 ⟩ H C P for both cases. The twin boundary corresponds to {"separators="|10 1 ¯ 0 } H C P after the phase transition. It is amazing that the reverse transition seems to be able to "memorize" and recover the initial BCC twins. The memory would be partly lost when plastic slips take place in the HCP phase before the reverse transition. In the recovered initial BCC twins, three major twin spacings are observed, which are well explained in terms of energy barriers of transition from the HCP phase to the BCC twin. Besides, the variant selection rule of the twin assisted phase transition is also discussed. The results of present work could be expected to give some clues for producing ultra-fine grain structures in materials exhibiting martensitic phase transition.

Microscopic theory of exchange and dipole-exchange spin waves in magnetic thin films

NASA Astrophysics Data System (ADS)

Pereira, Joao Milton, Jr.

The aim of this work is to develop a microscopic theory of bulk and surface spin wave modes (or magnons) in thin films of some specific ordered magnetic materials, particularly antiferromagnets. Both exchange and magnetic dipole-dipole interactions are taken into account, depending on the material and the wavevector regime. First we study the dispersion relations of spin waves for situations in which the dominant interaction is the short-range exchange coupling between the magnetic sites. We begin by investigating ferromagnetic films with a cubic body centered (b.c.c.) crystal structure a surfaces corresponding to (111) crystal planes. The spin wave frequencies are calculated by a method that generalizes previous techniques used for simpler systems, which allows us to find analytical solutions. The results are then compared with recent experimental data for Ni films grown epitaxially on a W substrate. Then we investigate spin waves in antiferromagnetic systems. Calculations are made for the dispersion relations of exchange-dominated spin waves in antiferromagnetic thin films with simple cubic (s.c.) crystal structures, for three different surface orientations, namely (001), (101) and (111). The results are obtained by using a method similar to the one developed for the ferromagnetic film in the previous chapter. We calculate the effect of finite film thickness in coupling the spin wave modes localized near the two surfaces, leading to a splitting of several of the mode branches that occur in the semi-infinite limit. Another aspect that we consider is the influence, for the (101) orientation, of the direction of propagation on the spin wave frequencies, as well as the effect of non-equivalent sublattices in the (111) case. Next, we investigate the spin waves in antiferromagnetic films made of materials in which the long-range dipole-dipole interaction between the magnetic sites is included, along with the exchange coupling. In this case, we employ a Hamiltonian formalism that uses a transformation of the spin operators to creation and annihilation operators. Initially, we calculate the linear dipole-exchange spin wave spectrum, by considering only the bilinear terms in the transformed Hamiltonian. The theory is applied to antiferromagnetic films with s.c. and b.c.c. structures. The higher-order terms are later included by means of a diagrammatic perturbation technique, which allows us to obtain expressions for the damping and energy shift of the spin wave modes in b.c.c. antiferromagnetic films. Numerical results are then shown for ultrathin films of the antiferromagnet MnF2.

Community Impact Report. Executive Summary, Fall 2000.

ERIC Educational Resources Information Center

Hodge, Valerie

This summary details Bellevue Community College's (BCC's) (Washington) short-term and long-term community impacts. Short-term community impacts include: (1) 34,994 students were educated and trained at BCC; (2) BCC employed over 2,272 people, 53% of whom lived in the BCC service area; (3) BCC total revenue was $62,966,226; (4) 28.6% of the total…

Hypermutation in Burkholderia cepacia complex is mediated by DNA mismatch repair inactivation and is highly prevalent in cystic fibrosis chronic respiratory infection.

PubMed

Martina, Pablo; Feliziani, Sofía; Juan, Carlos; Bettiol, Marisa; Gatti, Blanca; Yantorno, Osvaldo; Smania, Andrea M; Oliver, Antonio; Bosch, Alejandra

2014-11-01

The Burkholderia cepacia complex (Bcc) represents an important group of pathogens involved in long-term lung infection in cystic fibrosis (CF) patients. A positive selection of hypermutators, linked to antimicrobial resistance development, has been previously reported for Pseudomonas aeruginosa in this chronic infection setting. Hypermutability, however, has not yet been systematically evaluated in Bcc species. A total of 125 well characterized Bcc isolates recovered from 48 CF patients, 10 non-CF patients and 15 environmental samples were analyzed. In order to determine the prevalence of mutators their spontaneous mutation rates to rifampicin resistance were determined. In addition, the genetic basis of the mutator phenotypes was investigated by sequencing the mutS and mutL genes, the main components of the mismatch repair system (MRS). The overall prevalence of hypermutators in the collection analyzed was 13.6%, with highest occurrence (40.7%) among the chronically infected CF patients, belonging mainly to B. cenocepacia, B. multivorans, B. cepacia, and B. contaminans -the most frequently recovered Bcc species from CF patients worldwide. Thirteen (76.5%) of the hypermutators were defective in mutS and/or mutL. Finally, searching for a possible association between antimicrobial resistance and hypermutability, the resistance-profiles to 17 antimicrobial agents was evaluated. High antimicrobial resistance rates were documented for all the Bcc species recovered from CF patients, but, except for ciprofloxacin, a significant association with hypermutation was not detected. In conclusion, in the present study we demonstrate for the first time that, MRS-deficient Bcc species mutators are highly prevalent and positively selected in CF chronic lung infections. Hypermutation therefore, might be playing a key role in increasing bacterial adaptability to the CF-airway environment, facilitating the persistence of chronic lung infections. Copyright © 2014 Elsevier GmbH. All rights reserved.

Ab initio calculations of mechanical properties of bcc W-Re-Os random alloys: effects of transmutation of W

NASA Astrophysics Data System (ADS)

Li, Xiaojie; Schönecker, Stephan; Li, Ruihuan; Li, Xiaoqing; Wang, Yuanyuan; Zhao, Jijun; Johansson, Börje; Vitos, Levente

2016-07-01

To examine the effect of neutron transmutation on tungsten as the first wall material of fusion reactors, the elastic properties of W1-x-y  Re x  Os y (0  ⩽  x, y  ⩽  6%) random alloys in body centered cubic (bcc) structure are investigated systematically using the all-electron exact muffin-tin orbitals (EMTO) method in combination with the coherent-potential approximation (CPA). The calculated lattice constant and elastic properties of pure W are consistent with available experiments. Both Os and Re additions reduce the lattice constant and increase the bulk modulus of W, with Os having the stronger effect. The polycrystalline shear modulus, Young’s modulus and the Debye temperature increase (decrease) with the addition of Re (Os). Except for C 11, the other elastic parameters including C 12, C 44, Cauchy pressure, Poisson ratio, B/G, increase as a function of Re and Os concentration. The variations of the latter three parameters and the trend in the ratio of cleavage energy to shear modulus for the most dominant slip system indicate that the ductility of the alloy enhances with increasing Re and Os content. The calculated elastic anisotropy of bcc W slightly increases with the concentration of both alloying elements. The estimated melting temperatures of the W-Re-Os alloy suggest that Re or Os addition will reduce the melting temperature of pure W solid. The classical Labusch-Nabarro model for solid-solution hardening predicts larger strengthening effects in W1-y  Os y than in W1-x  Re x . A strong correlation between C‧ and the fcc-bcc structural energy difference for W1-x-y  Re x  Os y is revealed demonstrating that canonical band structure dictates the alloying effect on C‧. The structural energy difference is exploited to estimate the alloying effect on the ideal tensile strength in the [0 0 1] direction.

Ab initio calculations of mechanical properties of bcc W-Re-Os random alloys: effects of transmutation of W.

PubMed

Li, Xiaojie; Schönecker, Stephan; Li, Ruihuan; Li, Xiaoqing; Wang, Yuanyuan; Zhao, Jijun; Johansson, Börje; Vitos, Levente

2016-06-03

To examine the effect of neutron transmutation on tungsten as the first wall material of fusion reactors, the elastic properties of W 1-x-y  Re x  Os y (0  ⩽  x, y  ⩽  6%) random alloys in body centered cubic (bcc) structure are investigated systematically using the all-electron exact muffin-tin orbitals (EMTO) method in combination with the coherent-potential approximation (CPA). The calculated lattice constant and elastic properties of pure W are consistent with available experiments. Both Os and Re additions reduce the lattice constant and increase the bulk modulus of W, with Os having the stronger effect. The polycrystalline shear modulus, Young's modulus and the Debye temperature increase (decrease) with the addition of Re (Os). Except for C 11 , the other elastic parameters including C 12 , C 44 , Cauchy pressure, Poisson ratio, B/G, increase as a function of Re and Os concentration. The variations of the latter three parameters and the trend in the ratio of cleavage energy to shear modulus for the most dominant slip system indicate that the ductility of the alloy enhances with increasing Re and Os content. The calculated elastic anisotropy of bcc W slightly increases with the concentration of both alloying elements. The estimated melting temperatures of the W-Re-Os alloy suggest that Re or Os addition will reduce the melting temperature of pure W solid. The classical Labusch-Nabarro model for solid-solution hardening predicts larger strengthening effects in W 1-y  Os y than in W 1-x  Re x . A strong correlation between C' and the fcc-bcc structural energy difference for W 1-x-y  Re x  Os y is revealed demonstrating that canonical band structure dictates the alloying effect on C'. The structural energy difference is exploited to estimate the alloying effect on the ideal tensile strength in the [0 0 1] direction.

Interface Mediated Nucleation and Growth of Dislocations in fcc-bcc nanocomposite

NASA Astrophysics Data System (ADS)

Zhang, Ruifeng; Wang, Jian; Beyerlein, Irene J.; Germann, Timothy C.

2011-03-01

Heterophase interfaces play a crucial role in determining material strength for nanostructured materials because they can block, store, nucleate, and remove dislocations, the essential defects that enable plastic deformation. Much recent theoretical and experimental effort has been conducted on nanostructured Cu-Nb multilayer composites that exhibited extraordinarily high strength, ductility, and resistance to radiation and mechanical loading. In decreasing layer thicknesses to the order of a few tens of nanometers or less, the deformation behavior of such composites is mainly controlled by the Cu/Nb interface. In this work, we focus on the cooperative mechanisms of dislocation nucleation and growth from Cu/Nb interfaces, and their interaction with interface. Two types of experimentally observed Cu/Nb incoherent interfaces are comparatively studied. We found that the preferred dislocation nucleation sites are closely related to atomic interface structure, which in turn, depend on the orientation relationship. The activation stress and energies for an isolated Shockley dislocation loop of different sizes from specific interface sites depend strongly on dislocation size, atomic interface pattern, and loading conditions. Such findings provide important insight into the mechanical response of a wide range of fcc/bcc metallic nanocomposites via atomic interface design.

Molecular typing of Burkholderia cepacia complex isolated from patients attending an Italian Cystic Fibrosis Centre.

PubMed

Teri, Antonio; Sottotetti, Samantha; Biffi, Arianna; Girelli, Daniela; D'Accico, Monica; Arghittu, Milena; Colombo, Carla; Corti, Fabiola; Pizzamiglio, Giovanna; Cariani, Lisa

2018-04-01

Bacteria from the Burkholderia cepacia complex (Bcc) are capable of causing severe infections in patients with cystic fibrosis (CF). Bcc infection is often extremely difficult to treat due to its intrinsic resistance to multiple antibiotics. In addition, it seems to speed up the decline of lung function and is considered a contraindication for lung transplantation in CF. This study investigates the species of the Bcc strains recovered from chronically infected CF subjects by means of: isolation, identification methods and complete recA nucleotide sequences of 151 samples. Molecular typing showed that B. cenocepacia III is the dominant strain found in the group of subjects being treated at the Milan CF Centre (Italy) and that the infection is chronically maintained by the same species. Defining species by means of molecular analysis yields important information for the clinician in order to establish the most appropriate therapy and implement correct measures for prevention of transmission among CF subjects.

Phases and Dynamics of Self-Assembled DNA Programmed Nanocubes

NASA Astrophysics Data System (ADS)

Knorowski, Christopher; Travesset, Alex

2013-03-01

Systems of Nanoparticles grafted with complementary DNA strands have been shown to self-assemble into an array of superlattices. In this talk, we extend our previous model, which successfully predicted equilibrium phases and dynamics of assembly for spherical Nanoparticles without fitting parameters, to the case of nanocubes. We show that the phase diagram consists of bcc and sc lattices, depending on DNA length. The bcc lattices are either rotator and orientational glass or cubatic. For temperatures above the DNA melting temperature, the system is equivalent to f-star polymer systems, and consist of bcc, also with rotator, orientational glass or cubatic orientational order as well as sc. We also provide a characterization of the dynamics, including the role of topological defects in crystal nucleation and growth. This work is funded by DOE through the Ames Lab under Contract DE-AC02-07CH11358. Most simulations are performed on the Exalted GPU cluster, which is funded by a grant from Iowa State University and Nvidia Corp.

Role of distortion in the hcp vs fcc competition in rare-gas solids

NASA Astrophysics Data System (ADS)

Krainyukova, N. V.

2011-05-01

As a prototype of an initial or intermediate structure between hcp and fcc lattices we consider a distorted bcc crystal. We calculate the temperature and pressure dependences of the lattice parameters for the heavier rare gas solids Ar, Kr, Xe in a quasiharmonic approximation with Aziz potentials, and confirm earlier predictions that the hcp structure predominates over fcc in the bulk within wide ranges of P and T. The situation is different for confined clusters with up to 105 atoms, where, owing to the specific surface energetics and terminations, structures with five-fold symmetry made up of fcc fragments are dominant. As a next step we consider the free relaxation of differently distorted bcc clusters, and show that two types (monoclinic and orthorhombic) of initial distortion are a driving force for the final hcp vs fcc configurations. Possible energy relationships between the initial and final structures are obtained and analyzed.

Density-functional theory for fluid-solid and solid-solid phase transitions.

PubMed

Bharadwaj, Atul S; Singh, Yashwant

2017-03-01

We develop a theory to describe solid-solid phase transitions. The density functional formalism of classical statistical mechanics is used to find an exact expression for the difference in the grand thermodynamic potentials of the two coexisting phases. The expression involves both the symmetry conserving and the symmetry broken parts of the direct pair correlation function. The theory is used to calculate phase diagram of systems of soft spheres interacting via inverse power potentials u(r)=ε(σ/r)^{n}, where parameter n measures softness of the potential. We find that for 1/n<0.154 systems freeze into the face centered cubic (fcc) structure while for 1/n≥0.154 the body-centred-cubic (bcc) structure is preferred. The bcc structure transforms into the fcc structure upon increasing the density. The calculated phase diagram is in good agreement with the one found from molecular simulations.

Behavior of magnesium at high pressures and high temperatures

NASA Astrophysics Data System (ADS)

Cynn, H.; Evans, W.; Yoo, C. S.; Ohishi, Y.; Sata, N.; Shimomura, O.

2004-03-01

Structural stability relationship manifested by 3-, 4-, 5d-electron transition metals also appears in so-called nearly free electron metal, magnesium as exampled by HCP to BCC structure change at high pressures. This transition has been examined by theory and confirmed by experiment. Recently, HCP to DHCP crystal structure change has been reported at high temperatures below 20 GPa. However, this type of structure change is rather common in 4f-electron lanthanides. In this study, we used synchrotron x-ray diffraction to find out the relationship between BCC and DHCP employing a diamond anvil cell technique coupled with external and laser heating methods. We also examined pressure gradient effects in relation with the existence of DHCP. This work has been supported by PDRP program at the Lawrence Livermore National Laboratory, University of California under the auspices of the U.S. Department of Energy under Contract No. W-7405-ENG-48

Getting off the Bain path: Are there any metastable states of cubic elements?

NASA Astrophysics Data System (ADS)

Mehl, Michael J.; Boyer, Larry L.

2003-03-01

Body-centered and face-centered cubic crystals can be considered as special cases of a body-centered tetragonal crystal with c/a = 1 and 2, respectively. First-principles calculations along this Bain path show that elements with an fcc (bcc) ground state are elastically unstable with respect to a tetragonal distortion in the bcc (fcc) phase. Starting with a normally fcc element and calculating E(c/a) for c/a < 1 we find a local minimum near c/a = 2/3, while for a bcc element we find a local minimum at some c/a > 2. It is tempting to conclude that these bct minima, which are required by continuity, are metastable, but calculations by several authors show that, at least for Al, Cu, and Pd, the bct structures are unstable with respect to an orthorhombic distortion. We use a simple "magic strain" construction(L. L. Boyer, Acta Cryst. A) 45, FC29 (1989).(M. J. Mehl and L. L. Boyer, Phys. Rev. B) 43, 9498 (1991). to study the stability of these bct states, and present examples which suggest that no fcc or bcc element has a metastable bct state.

A new nanoscale metastable iron phase in carbon steels

PubMed Central

Liu, Tianwei; Zhang, Danxia; Liu, Qing; Zheng, Yanjun; Su, Yanjing; Zhao, Xinqing; Yin, Jiang; Song, Minghui; Ping, Dehai

2015-01-01

Metastable ω phase is common in body-centred cubic (bcc) metals and alloys, including high-alloying steels. Recent theoretical calculations also suggest that the ω structure may act as an intermediate phase for face-centred cubic (fcc)-to-bcc transformation. Thus far, the role of the ω phase played in fcc-bcc martensitic transformation in carbon steels has not been reported. In previous investigations on martensitic carbon steels, extra electron diffraction spots were frequently observed by transmission electron microscopy (TEM), and these spots were historically ascribed to the diffraction arising from either internal twins or carbides. In this paper, an intensive TEM investigation revealed that the extra spots are in fact attributed to the metastable ω phase in particle-like morphology with an overall size of several or dozens of nanometres. The strict orientation relationships between the ω phase and the ferrite matrix are in good agreement with those of the hexagonal (P6/mmm) ω phase in other bcc metals and alloys. The identification of the ω phase as well as the extra diffraction spots might provide a clue to help understand the physical mechanism of martensitic transformation in steels. PMID:26503890

Cadinane sesquiterpenoids from the basidiomycete Stereum cf. sanguinolentum BCC 22926.

PubMed

Bunyapaiboonsri, Taridaporn; Yoiprommarat, Seangaroon; Nopgason, Rujirek; Komwijit, Somjit; Veeranondha, Sukitaya; Puyngain, Pucharapa; Boonpratuang, Thitiya

2014-09-01

Stereumins Q-U, together with known stereumins A, B, K, L, and N, as well as ent-strobilols E and G were isolated from the culture of Stereum cf. sanguinolentum BCC 22926. Their structures were elucidated by extensive spectroscopic analyses. The absolute configurations of stereumins A and Q, as well as ent-strobilol E were established by application of the modified Mosher's method. Stereumin T displayed antibacterial activity against Bacilluscereus with a MIC value of 3.97μM. Copyright © 2014 Elsevier Ltd. All rights reserved.

Preoperative prediction of histopathological outcome in basal cell carcinoma: flat surface and multiple small erosions predict superficial basal cell carcinoma in lighter skin types.

PubMed

Ahnlide, I; Zalaudek, I; Nilsson, F; Bjellerup, M; Nielsen, K

2016-10-01

Prediction of the histopathological subtype of basal cell carcinoma (BCC) is important for tailoring optimal treatment, especially in patients with suspected superficial BCC (sBCC). To assess the accuracy of the preoperative prediction of subtypes of BCC in clinical practice, to evaluate whether dermoscopic examination enhances accuracy and to find dermoscopic criteria for discriminating sBCC from other subtypes. The main presurgical diagnosis was compared with the histopathological, postoperative diagnosis of routinely excised skin tumours in a predominantly fair-skinned patient cohort of northern Europe during a study period of 3 years (2011-13). The study period was split in two: during period 1, dermoscopy was optional (850 cases with a pre- or postoperative diagnosis of BCC), while during period 2 (after an educational dermoscopic update) dermoscopy was mandatory (651 cases). A classification tree based on clinical and dermoscopic features for prediction of sBCC was applied. For a total of 3544 excised skin tumours, the sensitivity for the diagnosis of BCC (any subtype) was 93·3%, specificity 91·8%, and the positive predictive value (PPV) 89·0%. The diagnostic accuracy as well as the PPV and the positive likelihood ratio for sBCC were significantly higher when dermoscopy was mandatory. A flat surface and multiple small erosions predicted sBCC. The study shows a high accuracy for an overall diagnosis of BCC and increased accuracy in prediction of sBCC for the period when dermoscopy was applied in all cases. The most discriminating findings for sBCC, based on clinical and dermoscopic features in this fair-skinned population, were a flat surface and multiple small erosions. © 2016 British Association of Dermatologists.

The effect of topical diclofenac 3% and calcitriol 3 μg/g on superficial basal cell carcinoma (sBCC) and nodular basal cell carcinoma (nBCC): A phase II, randomized controlled trial.

PubMed

Brinkhuizen, Tjinta; Frencken, Kiki J A; Nelemans, Patty J; Hoff, Marlou L S; Kelleners-Smeets, Nicole W J; Zur Hausen, Axel; van der Horst, Michiel P J; Rennspiess, Dorit; Winnepenninckx, Véronique J L; van Steensel, Maurice A M; Mosterd, Klara

2016-07-01

Nonsteroidal anti-inflammatory drugs and vitamin-D derivatives can target signaling pathways activated in basal cell carcinoma (BCC). We investigated the efficacy of topically applied diclofenac sodium 3% gel, calcitriol 3 μg/g ointment, and a combination of both in superficial BCC (sBCC) and nodular BCC. Patients with a primary, histologically proven sBCC (n = 64) or nodular BCC (n = 64) were randomized to topical diclofenac, calcitriol, combination of both, or no topical treatment (control group). After self-application twice daily under occlusion (8 weeks), tumors were excised. Primary outcome was posttreatment expression levels of proliferation (Ki-67) and antiapoptosis (B-cell lymphoma [Bcl-2]) immunohistochemical markers. Secondary outcomes were histologic clearance, adverse events, application-site reactions, and patient compliance. sBCC treated with diclofenac showed a significant decrease in Ki-67 (P < .001) and Bcl-2 (P = .001), and after combination therapy for Ki-67 (P = .012). Complete histologic tumor regression was seen in 64.3% (P = .0003) of sBCC (diclofenac) and 43.8% (P = .007) of sBCC (combination therapy) compared with 0.0% of controls. No significant changes were found in nodular BCC. Application-site reactions were mostly mild to moderate. The sample size was small. Our results suggest that topical diclofenac is a promising new treatment for sBCC. Its mode of action differs from available noninvasive therapies, and thus has an additive value. Copyright © 2016 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

Impact of environmental factors on couplings between bacterial community composition and ectoenzymatic activities in a lacustrine ecosystem.

PubMed

Boucher, Delphine; Debroas, Didier

2009-10-01

This study examined the effects of temporal changes in bacterial community composition (BCC) and environmental factors on potential ectoenzymatic activities (alpha-glucosidase, beta-glucosidase, alkaline phosphatase and leucine aminopeptidase) in a lacustrine ecosystem (Sep reservoir, France). BCC was assessed by terminal restriction fragment length polymorphism. Physical parameters, and inorganic and organic nutrient concentrations (dissolved carbohydrates and proteins) were measured in lakes and tributaries. According to the multivariate statistics (redundancy analysis), physical and chemical factors explained the largest part of leucine aminopeptidase activity, whereas the temporal changes of other ectoenzymatic activities were partly dependent on the variations in the BCC. In particular, the occurrence of occasional bacterial populations seemed to explain a lot of the variation in rates and patterns of polymer hydrolysis. The relation observed in this study between the bacterial structure and activity is discussed within the framework of biodiversity-ecosystem functioning.

Absence of metastable states in strained monoatomic cubic crystals.

NASA Astrophysics Data System (ADS)

Aguayo, Aarón; Mehl, Michael L.; de Coss, Romeo

2005-03-01

The Bain path distortion of a metal with an fcc (bcc) ground state toward the bcc (fcc) structure initially requires an increase in energy, but at some point along the Bain path the energy will again decrease until a local minimum is reached. We have studied the tetragonal distortion (Bain path) of monoatomic cubic crystals, using a combination of parametrized tight-binding and first-principles linearized augmented plane wave calculations. We show that this local minimum is unstable with respect to an elastic distortion, except in the rare case that the minimum is at the bcc (fcc) point on the Bain path. This shows that body-centered-tetragonal phases of these materials, which have been seen in epitaxially grown thin films, must be stabilized by the substrate and cannot be freestanding films. This work was partially supported by Consejo Nacional de Ciencia y Tecnolog'ia (CONACYT, M'exico) under Grant No. 43830-F.

Study of reversible magnetization in FeCoNi alloy nanowires with different diameters by first order reversal curve (FORC) diagrams

NASA Astrophysics Data System (ADS)

Samanifar, S.; Kashi, M. Almasi; Ramazani, A.

2018-05-01

Magnetic nanowires electrodeposited into solid templates are of high interest due to their tunable properties which are required for magnetic recording media and spintronic devices. Here, highly ordered arrays of FeCoNi NWs with varied diameters (between 60 and 150 nm) were fabricated into nanopores of hard-anodized aluminum oxide templates using pulsed ac electrodeposition technique. X-ray diffraction patterns indicated the formation of FeCoNi NWs with fcc FeNi and bcc FeCo alloy phases, being highly textured along the bcc [110] direction. Magnetic properties were studied by hysteresis loop measurements at room temperature and they showed reductions in coercivity and squareness values by increasing diameter. First-order reversal curve measurements revealed that, with increasing diameter from 60 to 150 nm, besides a transition from a single domain (SD) state to a pseudo SD state, an increase in the reversible magnetization component of the NWs from 11% to 24% occurred.

Crystal structure and phase stability in Fe{sub 1{minus}x}Co{sub x} from AB initio theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soederlind, P.; Abrikosov, I.A.; James, P.

1996-06-01

For alloys between Fe and Co, their magnetic properties determine their structure. From the occupation of d states, a phase diagram is expected which depend largely on the spin polarization. A method more elaborate than canonical band models is used to calculate the spin moment and crystal structure energies. This method was the multisublattice generalization of the coherent potential approximation in conjunction with the Linear-Muffin-Tin-Orbital method in the atomic sphere approximation. To treat itinerant magnetism, the Vosko-Wilk-Nusair parameterization was used for the local spin density approximation. The fcc, bcc, and hcp phases were studied as completely random alloys, while themore » {alpha}{prime} phase for off-stoichiometries were considered as partially ordered. Results are compared with experiment and canonical band model.« less

Magnetic and structural characterization of ultra-thin Fe (222) films

NASA Astrophysics Data System (ADS)

Loving, Melissa G.; Brown, Emily E.; Rizzo, Nicholas D.; Ambrose, Thomas F.

2018-05-01

Varied thickness body centered cubic (BCC) ultrathin Fe films (10-50Å) have been sputter deposited onto Si (111) substrates. BCC Fe with the novel (222) texture was obtained by H- terminating the Si (111) starting substrate then immediately depositing the magnetic films. Structural results derived from grazing incidence x-ray diffraction and x-ray reflectivity confirm the crystallographic texture, film thickness, and interface roughness. Magnetic results indicate that Fe (222) exhibits soft magnetic switching (easy axis), high anisotropy (hard axis), which is maintained across the thickness range, and a positive magnetostriction (for the thicker film layers). The observed soft magnetic switching in this system makes it an ideal candidate for future magnetic memory development as well as other microelectronics applications that utilize magnetic materials.

Safety and efficacy of vismodegib in patients aged ≥65 years with advanced basal cell carcinoma.

PubMed

Chang, Anne Lynn S; Lewis, Karl D; Arron, Sarah T; Migden, Michael R; Solomon, James A; Yoo, Simon; Day, Bann-Mo; McKenna, Edward F; Sekulic, Aleksandar

2016-11-15

Because many patients with unresectable basal cell carcinoma (BCC) are aged ≥65 years, this study explores the efficacy and safety of vismodegib in these patients with locally advanced (la) or metastatic (m) basal cell carcinoma (BCC) in the ERIVANCE BCC trial and the expanded access study (EAS).We compared patients aged ≥65 years to patients aged <65 years taking vismodegib 150 mg/day, using descriptive statistics for response and safety. Patients aged ≥65 years (laBCC/mBCC) were enrolled in ERIVANCE BCC (33/14) and EAS (27/26). Investigator-assessed best overall response rate in patients ≥65 and <65 years was 46.7%/35.7% and 72.7%/52.6% (laBCC/mBCC), respectively, in ERIVANCE BCC and 45.8%/33.3% and 46.9%/28.6%, respectively, in EAS. These differences were not clinically meaningful. Safety was similar in both groups, although those aged ≥65 years had a higher percentage of grade 3-5 adverse events than those aged <65 years. Vismodegib demonstrated similar clinical activity and adverse events regardless of age.

A theoretical study of the omega-phase transformation in metals

NASA Astrophysics Data System (ADS)

Sanati, Mahdi

I have studied the formation of o-phase from electronic and mesoscopic (domain wall) points of view. To study the formation of domain walls, I have extended the Landau model of Cook for the o-phase transition by including a spatial gradient (Ginzburg) term of the scalar order parameter. In general, the Landau free energy is an asymmetric double-well potential. From the variational derivative of the total free energy I obtained a static equilibrium condition. By solving this equation for different physical parameters and boundary conditions, I obtained different quasi-one-dimensional soliton-like solutions. These solutions correspond to three different types of domain walls between the o-phase and the beta-matrix. These results are used to model the formation of the o-phase in bcc Ti. Canonical band model and first principles calculations confirmed the instability of the bcc-phase of group III and IV transition metals with respect to the o-phase transformation. I showed that the d-electron density is the controlling parameter for this type of the transformation. Also the possibility of formation of the o-phase for rare earth metals is discussed. First-principles full-potential linear muffin-tin orbital method (FPLMTO) calculations are performed for o-type displacement of the atoms to study the formation of the o-phase in TiAl and Ti 3Al2Nb alloys. The results of my calculations showed an instability in ordered B2 TiAl structure with respect to the o-phase when one third of the Al atoms are replaced by Nb atoms. These phenomena are explained, first by symmetry arguments; then a pair potential model is used to illustrate this instability based on interactions between different pair of atoms derived from the electronic structure. In addition, importance of the atomic arrangements on the structural stability of the Ti3Al2 Nb system is discussed.

Comparative analysis of cytokeratin 15, TDAG51, cytokeratin 20 and androgen receptor in sclerosing adnexal neoplasms and variants of basal cell carcinoma.

PubMed

Evangelista, Mara Therese P; North, Jeffrey P

2015-11-01

Desmoplastic trichoepithelioma (DTE), morpheaform basal cell carcinoma (BCC) and microcystic adnexal carcinoma (MAC) are sclerosing adnexal neoplasms with overlapping histopathologic features. We compared cytokeratin 15, (CK15), T-cell death-associated gene 51 (TDAG51), cytokeratin 20 (CK20) and androgen receptor (AR) in differentiating these tumors and assessed their expression in BCC subtypes. Fifteen DTE, 15 infundibulocystic BCC, 18 micronodular BCC, 18 morpheaform BCC and 6 MAC were assessed for CK15, TDAG51, CK20 and AR expression. Quantitative CK15 staining was higher in DTE compared with BCC (p < 0.0001) and MAC (p = 0.02). Quantitative TDAG51 staining was higher in DTE than BCC (p < 0.0001). The CK20+AR- immunophenotype was 100% sensitive and specific in diagnosing DTE. The CK20-AR+ immunophenotype was 95.24% specific and 83.33% sensitive for BCC. The CK20-AR- immunophenotype was 83.33% sensitive and 90.91% specific for MAC. CK15, CK20 and AR were positive in 87, 53 and 67% of infundibulocystic BCC cases, respectively. Combination of CK20 and AR best differentiated these sclerosing adnexal neoplasms. Greater positivity for CK15 and TDAG51 generally favors benign lesions. Infundibulocystic BCC has higher CK20 and lower AR immunopositivity than other BCC variants and a high degree of CK15 and TDAG51 positivity. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Differential senescence capacities in meibomian gland carcinoma and basal cell carcinoma.

PubMed

Zhang, Leilei; Huang, Xiaolin; Zhu, Xiaowei; Ge, Shengfang; Gilson, Eric; Jia, Renbing; Ye, Jing; Fan, Xianqun

2016-03-15

Meibomian gland carcinoma (MGC) and basal cell carcinoma (BCC) are common eyelid carcinomas that exhibit highly dissimilar degrees of proliferation and prognoses. We address here the question of the differential mechanisms between these two eyelid cancers that explain their different outcome. A total of 102 confirmed MGC and 175 diagnosed BCC cases were analyzed. Twenty confirmed MGC and twenty diagnosed BCC cases were collected to determine the telomere length, the presence of senescent cells, and the expression levels of the telomere capping shelterin complex, P53, and the E3 ubiquitin ligase Siah1. Decreased protein levels of the shelterin subunits, shortened telomere length, over-expressed Ki-67, and Bcl2 as well as mutations in P53 were detected both in MGC and BCC. It suggests that the decreased protein levels of the shelterin complex and the shortened telomere length contribute to the tumorigenesis of MGC and BCC. However, several parameters distinguish MGC from BCC samples: (i) the mRNA level of the shelterin subunits decreased in MGC but it increased in BCC; (ii) P53 was more highly mutated in MGC; (iii) Siah1 mRNA was over-expressed in BCC; (iv) BCC samples contain a higher level of senescent cells; (v) Ki-67 and Bcl2 expression were lower in BCC. These results support a model where a preserved P53 checkpoint in BCC leads to cellular senescence and reduced tumor proliferation as compared to MGC. © 2015 UICC.

Defects at grain boundaries: A coarse-grained, three-dimensional description by the amplitude expansion of the phase-field crystal model

NASA Astrophysics Data System (ADS)

Salvalaglio, Marco; Backofen, Rainer; Elder, K. R.; Voigt, Axel

2018-05-01

We address a three-dimensional, coarse-grained description of dislocation networks at grain boundaries between rotated crystals. The so-called amplitude expansion of the phase-field crystal model is exploited with the aid of finite element method calculations. This approach allows for the description of microscopic features, such as dislocations, while simultaneously being able to describe length scales that are orders of magnitude larger than the lattice spacing. Moreover, it allows for the direct description of extended defects by means of a scalar order parameter. The versatility of this framework is shown by considering both fcc and bcc lattice symmetries and different rotation axes. First, the specific case of planar, twist grain boundaries is illustrated. The details of the method are reported and the consistency of the results with literature is discussed. Then, the dislocation networks forming at the interface between a spherical, rotated crystal embedded in an unrotated crystalline structure, are shown. Although explicitly accounting for dislocations which lead to an anisotropic shrinkage of the rotated grain, the extension of the spherical grain boundary is found to decrease linearly over time in agreement with the classical theory of grain growth and recent atomistic investigations. It is shown that the results obtained for a system with bcc symmetry agree very well with existing results, validating the methodology. Furthermore, fully original results are shown for fcc lattice symmetry, revealing the generality of the reported observations.

Importance of doping and frustration in itinerant Fe-doped Cr 2Al

DOE PAGES

Susner, M. A.; Parker, D. S.; Sefat, A. S.

2015-05-12

We performed an experimental and theoretical study comparing the effects of Fe-doping of Cr 2Al, an antiferromagnet with a N el temperature of 670 K, with known results on Fe-doping of antiferromagnetic bcc Cr. (Cr 1-xFe x) 2Al materials are found to exhibit a rapid suppression of antiferromagnetic order with the presence of Fe, decreasing T N to 170 K for x=0.10. Antiferromagnetic behavior disappears entirely at x≈0.125 after which point increasing paramagnetic behavior is exhibited. Moreover, this is unlike the effects of Fe doping of bcc antiferromagnetic Cr, in which T N gradually decreases followed by the appearance ofmore » a ferromagnetic state. Theoretical calculations explain that the Cr 2Al-Fe suppression of magnetic order originates from two effects: the first is band narrowing caused by doping of additional electrons from Fe substitution that weakens itinerant magnetism; the second is magnetic frustration of the Cr itinerant moments in Fe-substituted Cr 2Al. In pure-phase Cr 2Al, the Cr moments have an antiparallel alignment; however, these are destroyed through Fe substitution and the preference of Fe for parallel alignment with Cr. This is unlike bulk Fe-doped Cr alloys in which the Fe anti-aligns with the Cr atoms, and speaks to the importance of the Al atoms in the magnetic structure of Cr 2Al and Fe-doped Cr 2Al.« less

Evolution of anisotropy in bcc Fe distorted by interstitial boron

NASA Astrophysics Data System (ADS)

Gölden, Dominik; Zhang, Hongbin; Radulov, Iliya; Dirba, Imants; Komissinskiy, Philipp; Hildebrandt, Erwin; Alff, Lambert

2018-01-01

The evolution of magnetic anisotropy in bcc Fe as a function of interstitial boron atoms was investigated in thin films grown by molecular beam epitaxy. The thermodynamic nonequilibrium conditions during film growth allowed one to stabilize an interstitial boron content of about 14 at .% accompanied by lattice tetragonalization. The c /a ratio scaled linearly with the boron content up to a maximum value of 1.05 at 300 °C substrate growth temperature, with a room-temperature magnetization of. In contrast to nitrogen interstitials, the magnetic easy axis remained in-plane with an anisotropy of approximately -5.1 ×106erg /cm3 . Density functional theory calculations using the measured lattice parameters confirm this value and show that boron local ordering indeed favors in-plane magnetization. Given the increased temperature stability of boron interstitials as compared to nitrogen interstitials, this study will help to find possible ways to manipulate boron interstitials into a more favorable local order.

Baseline correction combined partial least squares algorithm and its application in on-line Fourier transform infrared quantitative analysis.

PubMed

Peng, Jiangtao; Peng, Silong; Xie, Qiong; Wei, Jiping

2011-04-01

In order to eliminate the lower order polynomial interferences, a new quantitative calibration algorithm "Baseline Correction Combined Partial Least Squares (BCC-PLS)", which combines baseline correction and conventional PLS, is proposed. By embedding baseline correction constraints into PLS weights selection, the proposed calibration algorithm overcomes the uncertainty in baseline correction and can meet the requirement of on-line attenuated total reflectance Fourier transform infrared (ATR-FTIR) quantitative analysis. The effectiveness of the algorithm is evaluated by the analysis of glucose and marzipan ATR-FTIR spectra. BCC-PLS algorithm shows improved prediction performance over PLS. The root mean square error of cross-validation (RMSECV) on marzipan spectra for the prediction of the moisture is found to be 0.53%, w/w (range 7-19%). The sugar content is predicted with a RMSECV of 2.04%, w/w (range 33-68%). Copyright © 2011 Elsevier B.V. All rights reserved.

Structural transition with thickness in films of poly-(styrene-b-2vinylpyridine) (PS-b-P2VP) diblock copolymer/homopolymer blends

NASA Astrophysics Data System (ADS)

Mishra, Vindhya; Kramer, Edward; Hur, Su-Mi; Fredrickson, Glenn; Sprung, Michael

2009-03-01

In multilayer thin films of spherical morphology block copolymers, the surface layers prefer hexagonal symmetry while the inner layers prefer BCC. Thin films with spherical morphology of PS-b-P2VP blends with short homopolymer polystyrene (hPS) chains have an HCP structure up to a thickness n* at which there is a transition to a face centered orthorhombic structure. Using grazing incidence small angle X-ray scattering and transmission electron microscopy we show that that n* increases from 5 to 9 with increase in hPS from 0 to 12 vol%. For thicknesses just below n* the HCP and FCO structures coexist, but on long annealing HCP prevails. We hypothesize that the PS segregates to the interstices in the HCP structure reducing the stretching of the PS blocks and the free energy penalty of HCP versus BCC inner layers. Self consistent field theoretic simulations are being carried out to see if this idea is correct.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frolov, T.; Setyawan, W.; Kurtz, R. J.

We report a computational discovery of novel grain boundary structures and multiple grain boundary phases in elemental bcc tungsten. While grain boundary structures created by the - surface method as a union of two perfect half crystals have been studied extensively, it is known that the method has limitations and does not always predict the correct ground states. Here, we use a newly developed computational tool, based on evolutionary algorithms, to perform a grand-canonical search of high-angle symmetric tilt boundary in tungsten, and we find new ground states and multiple phases that cannot be described using the conventional structural unitmore » model. We use MD simulations to demonstrate that the new structures can coexist at finite temperature in a closed system, confirming these are examples of different GB phases. The new ground state is confirmed by first-principles calculations.Evolutionary grand-canonical search predicts novel grain boundary structures and multiple grain boundary phases in elemental body-centered cubic (bcc) metals represented by tungsten, tantalum and molybdenum.« less

Induction of chemokine receptor CXCR4 expression by transforming growth factor-β1 in human basal cell carcinoma cells.

PubMed

Chu, Chia-Yu; Sheen, Yi-Shuan; Cha, Shih-Ting; Hu, Yeh-Fang; Tan, Ching-Ting; Chiu, Hsien-Ching; Chang, Cheng-Chi; Chen, Min-Wei; Kuo, Min-Liang; Jee, Shiou-Hwa

2013-11-01

Higher CXCR4 expression enhances basal cell carcinoma (BCC) invasion and angiogenesis. The underlying mechanism of increased CXCR4 expression in invasive BCC is still not well understood. To investigate the mechanisms involved in the regulation of CXCR4 expression in invasive BCC. We used qRT-PCR, RT-PCR, Western blot, and flow cytometric analyses to examine different CXCR4 levels among the clinical samples, co-cultured BCC cells and BCC cells treated with recombinant transforming growth factor-β1 (TGF-β1) and connective tissue growth factor (CTGF). Immunohistochemical studies were used to demonstrate the correlation between TGF-β1 and CXCR4 expressions. The signal transduction pathway and transcriptional regulation were confirmed by treatments with chemical inhibitors, neutralizing antibodies, or short interfering RNAs, as well as luciferase reporter activity. Invasive BCC has higher TGF-β1 and CTGF levels compared to non-invasive BCC. Non-contact dermal fibroblasts co-culture with human BCC cells also increases the expression of CXCR4 in BCC cells. Treatment with recombinant human TGF-β1, but not CTGF, enhanced the CXCR4 levels in time- and dose-dependent manners. The protein level and surface expression of CXCR4 in human BCC cells was increased by TGF-β1 treatment. TGF-β1 was intensely expressed in the surrounding fibroblasts of invasive BCC and was positively correlated with the CXCR4 expression of BCC cells. The transcriptional regulation of CXCR4 by TGF-β1 is mediated by its binding to the TGF-β receptor II and phosphorylation of the extracellular signal-related kinase 1/2 (ERK1/2)-ETS-1 pathway. TGF-β1 induces upregulation of CXCR4 in human BCC cells by phosphorylation of ERK1/2-ETS-1 pathway. Copyright © 2013 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

TA-GC cloning: A new simple and versatile technique for the directional cloning of PCR products for recombinant protein expression.

PubMed

Niarchos, Athanasios; Siora, Anastasia; Konstantinou, Evangelia; Kalampoki, Vasiliki; Lagoumintzis, George; Poulas, Konstantinos

2017-01-01

During the last few decades, the recombinant protein expression finds more and more applications. The cloning of protein-coding genes into expression vectors is required to be directional for proper expression, and versatile in order to facilitate gene insertion in multiple different vectors for expression tests. In this study, the TA-GC cloning method is proposed, as a new, simple and efficient method for the directional cloning of protein-coding genes in expression vectors. The presented method features several advantages over existing methods, which tend to be relatively more labour intensive, inflexible or expensive. The proposed method relies on the complementarity between single A- and G-overhangs of the protein-coding gene, obtained after a short incubation with T4 DNA polymerase, and T and C overhangs of the novel vector pET-BccI, created after digestion with the restriction endonuclease BccI. The novel protein-expression vector pET-BccI also facilitates the screening of transformed colonies for recombinant transformants. Evaluation experiments of the proposed TA-GC cloning method showed that 81% of the transformed colonies contained recombinant pET-BccI plasmids, and 98% of the recombinant colonies expressed the desired protein. This demonstrates that TA-GC cloning could be a valuable method for cloning protein-coding genes in expression vectors.

TA-GC cloning: A new simple and versatile technique for the directional cloning of PCR products for recombinant protein expression

PubMed Central

Niarchos, Athanasios; Siora, Anastasia; Konstantinou, Evangelia; Kalampoki, Vasiliki; Poulas, Konstantinos

2017-01-01

During the last few decades, the recombinant protein expression finds more and more applications. The cloning of protein-coding genes into expression vectors is required to be directional for proper expression, and versatile in order to facilitate gene insertion in multiple different vectors for expression tests. In this study, the TA-GC cloning method is proposed, as a new, simple and efficient method for the directional cloning of protein-coding genes in expression vectors. The presented method features several advantages over existing methods, which tend to be relatively more labour intensive, inflexible or expensive. The proposed method relies on the complementarity between single A- and G-overhangs of the protein-coding gene, obtained after a short incubation with T4 DNA polymerase, and T and C overhangs of the novel vector pET-BccI, created after digestion with the restriction endonuclease BccI. The novel protein-expression vector pET-BccI also facilitates the screening of transformed colonies for recombinant transformants. Evaluation experiments of the proposed TA-GC cloning method showed that 81% of the transformed colonies contained recombinant pET-BccI plasmids, and 98% of the recombinant colonies expressed the desired protein. This demonstrates that TA-GC cloning could be a valuable method for cloning protein-coding genes in expression vectors. PMID:29091919

Polymorphism control of superconductivity and magnetism in Cs(3)C(60) close to the Mott transition.

PubMed

Ganin, Alexey Y; Takabayashi, Yasuhiro; Jeglic, Peter; Arcon, Denis; Potocnik, Anton; Baker, Peter J; Ohishi, Yasuo; McDonald, Martin T; Tzirakis, Manolis D; McLennan, Alec; Darling, George R; Takata, Masaki; Rosseinsky, Matthew J; Prassides, Kosmas

2010-07-08

The crystal structure of a solid controls the interactions between the electronically active units and thus its electronic properties. In the high-temperature superconducting copper oxides, only one spatial arrangement of the electronically active Cu(2+) units-a two-dimensional square lattice-is available to study the competition between the cooperative electronic states of magnetic order and superconductivity. Crystals of the spherical molecular C(60)(3-) anion support both superconductivity and magnetism but can consist of fundamentally distinct three-dimensional arrangements of the anions. Superconductivity in the A(3)C(60) (A = alkali metal) fullerides has been exclusively associated with face-centred cubic (f.c.c.) packing of C(60)(3-) (refs 2, 3), but recently the most expanded (and thus having the highest superconducting transition temperature, T(c); ref. 4) composition Cs(3)C(60) has been isolated as a body-centred cubic (b.c.c.) packing, which supports both superconductivity and magnetic order. Here we isolate the f.c.c. polymorph of Cs(3)C(60) to show how the spatial arrangement of the electronically active units controls the competing superconducting and magnetic electronic ground states. Unlike all the other f.c.c. A(3)C(60) fullerides, f.c.c. Cs(3)C(60) is not a superconductor but a magnetic insulator at ambient pressure, and becomes superconducting under pressure. The magnetic ordering occurs at an order of magnitude lower temperature in the geometrically frustrated f.c.c. polymorph (Néel temperature T(N) = 2.2 K) than in the b.c.c.-based packing (T(N) = 46 K). The different lattice packings of C(60)(3-) change T(c) from 38 K in b.c.c. Cs(3)C(60) to 35 K in f.c.c. Cs(3)C(60) (the highest found in the f.c.c. A(3)C(60) family). The existence of two superconducting packings of the same electronically active unit reveals that T(c) scales universally in a structure-independent dome-like relationship with proximity to the Mott metal-insulator transition, which is governed by the role of electron correlations characteristic of high-temperature superconducting materials other than fullerides.

The clinical and histopathological characteristics of early-onset basal cell carcinoma in Asians.

PubMed

Yang, M Y; Kim, J M; Kim, G W; Mun, J H; Song, M; Ko, H C; Kim, B S; Kim, H S; Kim, M B

2017-01-01

Basal cell carcinoma (BCC) is by far the most common cancer in white populations. In addition, recent reports have demonstrated an increasing incidence of BCC in Korea. We have observed a significant number of early-onset BCC cases in which the disease occurred in patients younger than 50 years. To investigate the clinicopathological characteristics of early-onset BCC in an Asian population, specifically in Koreans. One hundred and five patients with early-onset BCC were enrolled from a total of 1047 BCC patients who underwent surgery between January 1997 and December 2014 (942 patients over the age of 50 years were designated as the control group). Early-onset BCC accounted for 10.03% of all 1047 cases and the incidence over time displayed an incremental trend. The early-onset group displayed similar results as the control group, with a predominance of female BCC patients and the majority of tumours displaying the following characteristics: small in size, occurring in sun-exposed areas and belonging to the noduloulcerative clinical subtype and nodular histopathological subtype. In comparison with a previous study in a Western population, the incidence of the disease in non-exposed areas of the body, as well as the proportion of tumours of the superficial histological subtype, were lower in Asian patients. Although the clinicopathological characteristics of BCC are well-known, these characteristics have not been determined for early-onset BCC in an Asian population. Therefore, this study is the first report on early-onset BCC in Asians, specifically in a Korean patient group. © 2016 European Academy of Dermatology and Venereology.

Clinical characteristics of basal cell carcinoma in a tertiary hospital in Sarawak, Malaysia.

PubMed

Yap, Felix Boon Bin

2010-02-01

Basal cell carcinoma (BCC) is the most common skin cancer among Orientals. Data on this malignancy is lacking in Malaysia, prompting a retrospective study to determine the clinical characteristics in the skin clinic, Sarawak General Hospital between 2000 and 2008. Demographic data and clinical features of 64 histopathologically proven BCC from 43 patients were retrieved. Statistical analysis was performed comparing the clinical characteristics based on the region of involvement and gender. The mean age of presentation was 60.9 years. Male to female ratio was 1.05. Majority of the patients were Chinese (44.2%) followed by Malays (32.6%), Bidayuhs (14.0%) and Ibans (6.9%). Nodular BCC accounted for 95.3% of cases while 4.7% were superficial BCC. All the nodular BCC were pigmented. Ulceration was noted in 18%. There were 82.8% of BCC on the head and neck region and 17.2% on the trunk and limb region. BCC on the latter region were larger (mean 35.0 cf. 14.4 mm, p < 0.001) and ulcerated (45.5% cf. 11.3%, p = 0.01). Superficial BCC were also more frequently encountered in this region (18.2% cf. 1.9%, p = 0.02). Compared to women, men had larger BCC (mean 21.1 cf. 13.3 mm, p = 0.03) and kept them for a longer duration (mean 21.6 cf. 13.3 months, p = 0.04). Clinical characteristics of BCC in Sarawak were similar to other Asian studies. Additionally, BCC on the trunk and limbs and in men were larger, ulcerative and long standing warranting better efforts for earlier detection.

From Microhabitat of Floral Nectar Up to Biogeographic Scale: Novel Insights on Neutral and Niche Bacterial Assemblies.

PubMed

Aizenberg-Gershtein, Yana; Izhaki, Ido; Halpern, Malka

2017-07-01

Microbial model systems are very useful in addressing macro-ecological questions. Two major theories exist to date, to explain the community structure of organisms: (1) the dispersal (neutral) assembly theory which predicts that community similarity decreases with increasing geographic distance, independent of any environmental variables, and (2) the niche assembly theory which predicts that the communities' compositions are more homogeneous among sites characterized by similar environmental conditions. Our study system offered a unique opportunity to investigate the relative role of environmental conditions and spatial factors in shaping community composition. We explored the bacterial community composition (BCC) of Nicotiana glauca floral nectar using the Illumina MiSeq technique at three spatial scales (plants, site, and region) and two taxonomic levels. Floral nectar samples were collected from 69 N. glauca plants at 11 different sites along a 200-km transect in Israel, along three biogeographic regions. A distance decay of BCC was found among all plants throughout Israel, but such pattern was not found among either sites or biogeographical regions. The BCC was also governed by environmental conditions in all examined scales (from the plant up to the biogeographical region). We also found that taxonomic resolution (89 and 97% sequence identity for clustering operational taxonomic units) affected the results of these BCC analyses. Hence, our study revealed that the BCC in N. glauca floral nectar is shaped by both the environmental conditions and the distance between plants, depending on the sampling scale under examination as well as by taxonomic resolution.

Transformation of BCC and B2 High Temperature Phases to HCP and Orthorhombic Structures in the Ti-Al-Nb System. Part I: Microstructural Predictions Based on a Subgroup Relation Between Phases

PubMed Central

Bendersky, L. A.; Roytburd, A.; Boettinger, W. J.

1993-01-01

Possible paths for the constant composition coherent transformation of BCC or B2 high temperature phases to low temperature HCP or Orthorhombic phases in the Ti-Al-Nb system are analyzed using a sequence of ciystallographic structural relationships developed from subgroup symmetry relations. Symmetry elements lost in each step of the sequence determine the possibilities for variants of the low symmetry phase and domains that can be present in the microstructure. The orientation of interdomain interfaces is determined by requiring the existence of a strain-free interface between the domains. Polydomain structures are also determined that minimize elastic energy. Microstructural predictions are made for comparison to experimental results given by Benderslcy and Boettinger [J. Res. Natl. Inst. Stand. Technol. 98, 585 (1993)]. PMID:28053487

Experimental evidence of body centered cubic iron in Earth's core

NASA Astrophysics Data System (ADS)

Hrubiak, R.; Meng, Y.; Shen, G.

2017-12-01

The Earth's core is mainly composed of iron. While seismic evidence has shown a liquid outer core and a solid inner core, the crystalline nature of the solid iron at the core condition remains debated, largely due to the difficulties in experimental determination of exact polymorphs at corresponding pressure-temperature conditions. We have examined crystal structures of iron up to 220 GPa and 6000 K with x-ray diffraction using a double-sided laser heating system at HPCAT, Advanced Photon Source. The iron sample is confined in a small chamber surrounded by single crystal MgO. The laser power can be modulated together with temperature measurements. The modulated heating of iron in an MgO single crystal matrix allows for microstructure analysis during heating and after the sample is quenched. We present experimental evidence of a body-centered-cubic (BCC) iron from about 100 GPa and 3000 K to at least 220 GPa and 4000 K. The observed BCC phase may be consistent with a theoretically predicted BCC phase that is dynamically stable in similar pressure-temperature conditions [1]. We will discuss the stability region of the BCC phase and the melting curve of iron and their implications in the nature of the Earth's inner core. References: A. B. Belonoshko et al., Nat. Geosci., 1-6 (2017).

X-ray Emission Spectroscopy in Magnetic 3d-Transition Metals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iota, V; Park, J; Baer, B

2003-11-18

The application of high pressure affects the band structure and magnetic interactions in solids by modifying nearest-neighbor distances and interatomic potentials. While all materials experience electronic changes with increasing pressure, spin polarized, strongly electron correlated materials are expected to undergo the most dramatic transformations. In such materials, (d and f-electron metals and compounds), applied pressure reduces the strength of on-site correlations, leading to increased electron delocalization and, eventually, to loss of its magnetism. In this ongoing project, we study the electronic and magnetic properties of Group VIII, 3d (Fe, Co and Ni) magnetic transition metals and their compounds at highmore » pressures. The high-pressure properties of magnetic 3d-transition metals and compounds have been studied extensively over the years, because of iron being a major constituent of the Earth's core and its relevance to the planetary modeling to understand the chemical composition, internal structure, and geomagnetism. However, the fundamental scientific interest in the high-pressure properties of magnetic 3d-electron systems extends well beyond the geophysical applications to include the electron correlation-driven physics. The role of magnetic interactions in the stabilization of the ''non-standard'' ambient pressure structures of Fe, Co and Ni is still incompletely understood. Theoretical studies have predicted (and high pressure experiments are beginning to show) strong correlations between the electronic structure and phase stability in these materials. The phase diagrams of magnetic 3d systems reflect a delicate balance between spin interactions and structural configuration. At ambient conditions, the crystal structures of {alpha}-Fe(bcc) and {var_epsilon}-Co(hcp) phases depart from the standard sequence (hcp {yields} bcc{yields} hcp {yields} fcc), as observed in all other non-magnetic transition metals with increasing the d-band occupancy, and are different from those of their 4d- and 5d-counter parts. This anomalous behavior has been interpreted in terms of the spin-polarized d-band altering the d-band occupancy [1]. At high pressures, however, the d-valence band is expected to broaden resulting in a suppression or even a complete loss of magnetism. Experimentally, ferromagnetic {alpha}(bcc)-Fe has been confirmed to transform to non-magnetic {var_epsilon}-Fe (hcp) at 10 GPa [2,3]. Recently, we have also observed a similar transition in Co from ferromagnetic {alpha}(hcp)-Co to likely nonmagnetic {beta}(fcc)-Co at 105 GPa[4]. A similar structural phase transition is expected in Ni, probably in the second-order fcc-fcc transition. However, there has been no directly measured change in magnetism associated with the structural phase transition in Co, nor has yet been confirmed such an iso-structural phase transition in Ni. Similar electronic transitions have been proposed in these 3d-transition metal oxides (FeO, CoO and NiO) from high spin (magnetic) to low spin (nonmagnetic) states [5]. In each of these systems, the magnetic transition is accompanied by a first-order structural transition involving large volume collapse (10% in FeO, for example). So far, there have been no electronic measurements under pressure confirming these significant theoretical predictions, although the predicted pressures for the volume collapse transitions are within the experimental pressure range (80-200GPa).« less

First-Principles Study of Thermodynamic and Magnetic Properties of Alloys

NASA Astrophysics Data System (ADS)

Zhuravlev, Ivan

The standard theoretical framework for predicting phase diagrams and other thermodynamic properties of alloys requires an adequate representation of the formation enthalpy. An important part of the formation enthalpy in size-mismatched alloys comes from atomic relaxations. The harmonic Kanzaki-Krivoglaz-Khachaturyan model of strain-induced interaction is generalized to concentrated size-mismatched alloys and adapted to first-principles calculations. The configuration dependence of both Kanzaki forces and force constants is represented by real-space cluster expansions that can be constructed based on the calculated forces. Developed configuration-dependent lattice deformation model is implemented for the fcc lattice and applied to Cu1-x Aux and Fe1-x Ptx alloys for concentrations x = 0.25, 0.5, and 0.75. The model is further adapted to concentration wave analysis and Monte Carlo. Good agreement with experiment is found for all systems except CuAu3 and FePt3. The structural and ordering energetics are studied in Au-Fe alloys by combining DFT calculations with effective Hamiltonian techniques: a cluster expansion with structural filters, and CLDM. The phase separation tendency in Au-Fe persists even if the fcc-bcc decomposition is suppressed. The relative stability of disordered bcc and fcc phases observed in nanoparticles is reproduced, but the fully ordered L10 AuFe, L12 Au3Fe, and L1 2 AuFe3 structures are unstable in DFT. Effects of magnetism on the chemical ordering are also discussed. Magnetocrystalline anisotropy is one of the key properties of a magnetic material. Understanding of its temperature and concentration dependence is a challenging theoretical problem with implications for the design of better materials for permanent magnets and other applications. The origins of the anomalous temperature dependence of magnetocrystalline anisotropy in (Fe 1-xCox)2B alloys are elucidated using first-principles calculations within the disordered local moment model. Excellent agreement with experimental data is obtained. Electronic structure calculations are used to examine the magnetic properties of Fe2P-based alloys and the mechanisms through which the Curie temperature and magnetocrystalline anisotropy can be optimized for specific applications. It is found that at elevated temperatures the magnetic interaction in pure Fe2P develops a pronounced two-dimensional character. Co-alloying of Fe2P with Co (or Ni) and Si is suggested as a strategy for maximizing the magnetocrystalline anisotropy above room temperature.

Magnetic cluster expansion model for random and ordered magnetic face-centered cubic Fe-Ni-Cr alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lavrentiev, M. Yu., E-mail: Mikhail.Lavrentiev@ukaea.uk; Nguyen-Manh, D.; Dudarev, S. L.

A Magnetic Cluster Expansion model for ternary face-centered cubic Fe-Ni-Cr alloys has been developed, using DFT data spanning binary and ternary alloy configurations. Using this Magnetic Cluster Expansion model Hamiltonian, we perform Monte Carlo simulations and explore magnetic structures of alloys over the entire range of compositions, considering both random and ordered alloy structures. In random alloys, the removal of magnetic collinearity constraint reduces the total magnetic moment but does not affect the predicted range of compositions where the alloys adopt low-temperature ferromagnetic configurations. During alloying of ordered fcc Fe-Ni compounds with Cr, chromium atoms tend to replace nickel rathermore » than iron atoms. Replacement of Ni by Cr in ordered alloys with high iron content increases the Curie temperature of the alloys. This can be explained by strong antiferromagnetic Fe-Cr coupling, similar to that found in bcc Fe-Cr solutions, where the Curie temperature increase, predicted by simulations as a function of Cr concentration, is confirmed by experimental observations. In random alloys, both magnetization and the Curie temperature decrease abruptly with increasing chromium content, in agreement with experiment.« less

Identification of Human Cutaneous Basal Cell Carcinoma Cancer Stem Cells.

PubMed

Morgan, Huw; Olivero, Carlotta; Patel, Girish K

2018-04-20

The cancer stem cell model states that a subset of tumor cells, called "cancer stem cells," can initiate and propagate tumor growth through self-renewal, high proliferative capacity, and their ability to recreate tumor heterogeneity. In basal cell carcinoma (BCC), we have shown that tumor cells that express the cell surface protein CD200 fulfill the cancer stem cell hypothesis. CD200+ CD45- BCC cells represent 0.05-3.96% of all BCC cells and reside in small clusters at the tumor periphery. Using a novel, reproducible in vivo xenograft growth assay, we determined that tumor-initiating cell (TIC) frequencies are approximately 1 per 1.5 million unsorted BCC cells. The CD200+ CD45- BCC subpopulation recreated BCC tumor growth in vivo with typical histological architecture and expression of sonic hedgehog-regulated genes. Reproducible in vivo BCC growth was achieved with as few as 10,000 CD200+ CD45- cells, representing ~1500-fold enrichment. The methods used to identify and purify CD200+ CD45- BCC cells, as well as characterize gene expression, are described herein.

Basal cell carcinoma of the eyelid in Finland during 1953-97.

PubMed

Paavilainen, Ville; Tuominen, Juhani; Pukkala, Eero; Saari, K Matti

2005-04-01

To study the incidence of basal cell carcinoma (BCC) of the eyelid in Finland. We studied 6241 cases of BCC of the eyelid reported to the nationwide Finnish Cancer Registry during 1953-97. We determined the age- and sex- specific incidence rates and overall rates adjusted for age to the world standard population, and social class- and occupation-specific standardized incidence ratios, with the total Finnish population as reference. The incidence rates of BCC of the eyelid varied between 0.7 and 3.0 per 100 000 person-years in men and between 0.5 and 2.8 per 100 000 person-years in women during the study period. The age-adjusted incidence rates of BCC of the eyelid increased during 1953-87 (p < 0.0001). The incidence of BCC of the eyelid rose significantly with age. There were no significant differences in standardized incidence ratios (SIRs) for BCC of the eyelid between different social class and occupation categories. Age-adjusted incidence rates showed that BCC of the eyelid was more than twice as frequent during 1978-97 than before 1968. Ageing may partly explain the increased incidence of BCC of the eyelid, whereas there were no differences in the SIRs for BCC of the eyelid between different social class and occupation categories in Finland.

Cancer associated fibroblasts (CAFs) are activated in cutaneous basal cell carcinoma and in the peritumoural skin.

PubMed

Omland, Silje Haukali; Wettergren, Erika Elgstrand; Mollerup, Sarah; Asplund, Maria; Mourier, Tobias; Hansen, Anders Johannes; Gniadecki, Robert

2017-10-07

Cutaneous basal cell carcinoma (BCC) is the commonest cancer worldwide. BCC is locally invasive and the surrounding stromal microenvironment is pivotal for tumourigenesis. Cancer associated fibroblasts (CAFs) in the microenvironment are essential for tumour growth in a variety of neoplasms but their role in BCC is poorly understood. Material included facial BCC and control skin from the peritumoural area and from the buttocks. With next-generation sequencing (NGS) we compared mRNA expression between BCC and peritumoural skin. qRT-PCR, immunohistochemical and immunofluorescent staining were performed to validate the NGS results and to investigate CAF-related cyto-and chemokines. NGS revealed upregulation of 65 genes in BCC coding for extracellular matrix components pointing at CAF-related matrix remodeling. qRT-PCR showed increased mRNA expression of CAF markers FAP-α, PDGFR-β and prolyl-4-hydroxylase in BCC. Peritumoural skin (but not buttock skin) also exhibited high expression of PDGFR-β and prolyl-4-hydroxylase but not FAP-α. We found a similar pattern for the CAF-associated chemokines CCL17, CCL18, CCL22, CCL25, CXCL12 and IL6 with high expression in BCC and peritumoural skin but absence in buttock skin. Immunofluorescence revealed correlation between FAP-α and PDGFR-β and CXCL12 and CCL17. Matrix remodeling is the most prominent molecular feature of BCC. CAFs are present within BCC stroma and associated with increased expression of chemokines involved in tumour progression and immunosuppression (CXCL12, CCL17). Fibroblasts from chronically sun-exposed skin near tumours show gene expression patterns resembling that of CAFs, indicating that stromal fibroblasts in cancer-free surgical BCC margins exhibit a tumour promoting phenotype.

The stability of the epitaxially introduced metastable metallic structures of thin layers and multilayers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cadeville, M.C.

Among the very large number of metallic thin films, sandwiches and multilayers which have been elaborated by epitaxy on various single crystalline substrates during the last decade, few new structures are reported. Limiting to the case of 3d metals, one finds with a great confidence bcc Cobalt, possibly bee Nickel and a non-compact hexagonal (hp) iron. Moreover structures existing at high temperature under ambient pressure are epitaxially stabilized at room temperature (RT) like fcc Cobalt, fcc Iron, fcc and bcc Manganese. The hcp iron which is stable under high pressure at RT would not be epitaxially stabilized at ambient pressuremore » conversely to first findings. The critical thickness of the metastable phase is generally limited to some monolayers in thin films, being slightly increased in sandwiches or multilayers, even if the phenomenological wetting criterion to build superlattices is not satisfied. No increased magnetic moment has been found up to now in the expanded lattices, contrary to band structure calculation predictions. 56 refs.« less

Ab initio simulations of iron-nickel alloys at Earth's core conditions

NASA Astrophysics Data System (ADS)

Côté, Alexander S.; Vočadlo, Lidunka; Brodholt, John P.

2012-09-01

We report ab initio density functional theory calculations on iron-nickel (FeNi) alloys at conditions representative of the Earth's inner core. We test different concentrations of Ni, up to ∼39 wt% using ab initio lattice dynamics, and investigate the thermodynamic and vibrational stability of the three candidate crystal structures (bcc, hcp and fcc). First of all, at inner core pressures, we find that pure Fe transforms from the hcp to the fcc phase at around 6000 K. Secondly, in agreement with low pressure experiments on Fe-Ni alloys, we find the fcc structure is stabilised by the incorporation of Ni under core pressures and temperatures. Our results show that the fcc structure may, therefore, be stable under core conditions depending on the temperature in the inner core and the Ni content. Lastly, we find that within the quasi-harmonic approximation, there is no stability field for FeNi alloys in the bcc structure under core conditions.

Simulations of wave propagation and disorder in 3D non-close-packed colloidal photonic crystals with low refractive index contrast.

PubMed

Glushko, O; Meisels, R; Kuchar, F

2010-03-29

The plane-wave expansion method (PWEM), the multiple-scattering method (MSM) and the 3D finite-difference time-domain method (FDTD) are applied for simulations of propagation of electromagnetic waves through 3D colloidal photonic crystals. The system investigated is not a "usual" artificial opal with close-packed fcc lattice but a dilute bcc structure which occurs due to long-range repulsive interaction between electrically charged colloidal particles during the growth process. The basic optical properties of non-close-packed colloidal PhCs are explored by examining the band structure and reflection spectra for a bcc lattice of silica spheres in an aqueous medium. Finite size effects and correspondence between the Bragg model, band structure and reflection spectra are discussed. The effects of size, positional and missing-spheres disorder are investigated. In addition, by analyzing the results of experimental work we show that the fabricated structures have reduced plane-to-plane distance probably due to the effect of gravity during growth.

Atomistic study on the FCC/BCC interface structure with {112}KS orientation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kang, Keonwook; Beyerlein, Irene; Han, Weizhong

2011-09-23

In this study, atomistic simulation is used to explore the atomic interface structure, the intrinsic defect network, and mechanism of twin formation from the {112}KS Cu-Nb interface. The interface structure of different material systems AI-Fe and AI-Nb are also compared with Cu-Nb interface.

bcc-to-hcp transformation pathways for iron versus hydrostatic pressure: Coupled shuffle and shear modes

NASA Astrophysics Data System (ADS)

Liu, J. B.; Johnson, D. D.

2009-04-01

Using density-functional theory, we calculate the potential-energy surface (PES), minimum-energy pathway (MEP), and transition state (TS) versus hydrostatic pressure σhyd for the reconstructive transformation in Fe from body-centered cubic (bcc) to hexagonal closed-packed (hcp). At fixed σhyd , the PES is described by coupled shear (γ) and shuffle (η) modes and is determined from structurally minimized hcp-bcc energy differences at a set of (η,γ) . We fit the PES using symmetry-adapted polynomials, permitting the MEP to be found analytically. The MEP is continuous and fully explains the transformation and its associated magnetization and volume discontinuity at TS. We show that σhyd (while not able to induce shear) dramatically alters the MEP to drive reconstruction by a shuffle-only mode at ≤30GPa , as observed. Finally, we relate our polynomial-based results to Landau and nudge-elastic-band approaches and show they yield incorrect MEP in general.

Usefulness of confocal microscopy in distinguishing between basal cell carcinoma and intradermal melanocytic nevus on the face.

PubMed

Gamo, R; Floristan, U; Pampín, A; Caro, D; Pinedo, F; López-Estebaranz, J L

2015-10-01

The clinical distinction between basal cell carcinoma (BCC) and intradermal melanocytic nevus lesions on the face can be difficult, particularly in young patients or patients with multiple nevi. Dermoscopy is a useful tool for analyzing characteristic dermoscopic features of BCC, such as cartwheel structures, maple leaf-like areas, blue-gray nests and dots, and ulceration. It also reveals arborizing telangiectatic vessels and prominent curved vessels, which are typical of BCC, and comma vessels, which are typical of intradermal melanocytic nevi. It is, however, not always easy to distinguish between these 2 conditions, even when dermoscopy is used. We describe 2 facial lesions that posed a clinical and dermoscopic challenge in two 38-year-old patients; confocal microscopy showed separation between tumor nests and stroma and polarized nuclei, which are confocal microscopy features of basal cell carcinoma. Copyright © 2014 Elsevier España, S.L.U. y AEDV. All rights reserved.

Composition and extracellular enzymatic function of pelagic, particle-associated, and benthic bacterial communities in the central Arctic Ocean

NASA Astrophysics Data System (ADS)

Balmonte, J. P.; Teske, A.; Arnosti, C.

2016-02-01

The structure and function of Arctic bacterial communities have rarely been studied in concert, but are crucial to our understanding of biogeochemical cycles. As the Arctic transitions to become seasonally-ice free, a critical priority is to elucidate the present ecological role and environmental dependence of Arctic bacterial communities. We investigated the depth and regional variations in Central Arctic bacterial community composition (BCC) and extracellular enzymatic activities (EEA)—the initial step in organic matter breakdown—to explore links between community structure and function. Samples were collected across a gradient of sea-ice cover (open ocean, first year ice, multi-year ice) from 79°N to 88°N and from surface to bottom waters ( 3.5 to 4.5 km). Pelagic BCC most strongly varies with hydrography and with particle-association, which likely selects for a specialized community of heterotrophic opportunists; benthic BCC show little regional variation. In contrast, EEA reveal significant depth and regional differences in hydrolysis rates as well as in the spectrum of substrates hydrolyzed. Particle-associated EEA reveal an equal or greater range of enzymatic capabilities than in bulk-seawater measurements, supporting previous findings that particles are hotspots of microbial heterotrophic activity. These patterns suggest a complex relationship between BCC, EEA, and the environment: while water mass characteristics consistently differentiate bacterial communities, additional local factors shape their capabilities to hydrolyze organic matter. Multivariate analyses will be used to further explore the relationships between composition and function as well as their correlations with environmental data. Our findings provide a baseline for future comparisons and initial insight into the functionality and biogeography of Arctic bacterial communities.

Structure and magnetic properties of Fe-Co-B alloy thin films prepared on cubic (001) single-crystal substrates

NASA Astrophysics Data System (ADS)

Ohtake, Mitsuru; Serizawa, Kana; Futamoto, Masaaki; Kirino, Fumiyoshi; Inaba, Nobuyuki

2018-04-01

Fe70Co30 and (Fe70Co30)0.95B5 (at. %) alloy films of 5 nm thickness are prepared by sputtering on cubic (001) oxide substrates at 200 °C. The lattice mismatch between film and substrate is varied from -4.2%, 0%, to +3.5% by employing MgO, MgAl2O4, and SrTiO3 substrates, respectively. Fe70Co30 and (Fe70Co30)0.95B5 single-crystal films with bcc structure grow epitaxially on all the substrates in the orientation relationship of (001)[110]film || (001)[100]substrate. The in-plane and out-of-plane lattice constants, a and c, are in agreement within small differences ranging between +1.1% and -0.9% with the value of bulk bcc-Fe70Co30 crystal, even though there exist the lattice mismatches of -4.2% and +3.5%. The result indicates that misfit dislocations are introduced around the film/substrate interface when films are deposited on MgO and SrTiO3 substrates. The single-crystal films show in-plane magnetic anisotropies with the easy magnetization direction of bcc[100], which are reflecting the magnetocrystalline anisotropy of bulk Fe70Co30 crystal.

Exopolysaccharides produced by clinical strains belonging to the Burkholderia cepacia complex.

PubMed

Herasimenka, Yury; Cescutti, Paola; Impallomeni, Giuseppe; Campana, Silvia; Taccetti, Giovanni; Ravenni, Novella; Zanetti, Flavio; Rizzo, Roberto

2007-04-01

In the frame of a research line dedicated to better clarify the role of exopolysaccharides (EPS) in bacterial virulence, EPS produced by species of the Burkholderia cepacia complex (Bcc), namely Burkholderia multivorans, Burkholderia cenocepacia, and a Bcc member of undetermined genomovar, all isolated at the Cystic Fibrosis Regional Centre of Florence (Italy), were investigated for they structural properties. Three strains of B. multivorans, three of B. cenocepacia and one of a Bcc member of undetermined genomovar were isolated from CF patients. The reference strains C1576 and J2315, for genomovar II and III, respectively, were included in the study. The bacteria were grown on solid media, the exopolysaccharides produced were purified, and their structures were determined. In addition, sugar analysis of sputum samples was accomplished to search for EPS produced in vivo. Six strains out of seven produced the exopolysaccharide cepacian, while one strain of B. multivorans produced a completely different polymer, previously known in the literature as PS1. Two strains synthesised very small amounts of EPS. No definitive evidence for the presence of cepacian in sputum samples was found. Most strains examined produced abundant amounts of polysaccharides. Cepacian was the most common EPS isolated and its production was not associated to a particular genomovar.

Influence of Annealing on Microstructure and Mechanical Properties of Refractory CoCrMoNbTi0.4 High-Entropy Alloy

NASA Astrophysics Data System (ADS)

Zhang, Mina; Zhou, Xianglin; Zhu, Wuzhi; Li, Jinghao

2018-04-01

A novel refractory CoCrMoNbTi0.4 high-entropy alloy (HEA) was prepared via vacuum arc melting. After annealing treatment at different temperatures, the microstructure evolution, phase stability, and mechanical properties of the alloy were investigated. The alloy was composed of two primary body-centered cubic structures (BCC1 and BCC2) and a small amount of (Co, Cr)2Nb-type Laves phase under different annealing conditions. The microhardness and compressive strength of the heat-treated alloy was significantly enhanced by the solid-solution strengthening of the BCC phase matrix and newborn Laves phase. Especially, the alloy annealed at 1473 K (1200 °C) achieved the maximum hardness and compressive strength values of 959 ± 2 HV0.5 and 1790 MPa, respectively, owing to the enhanced volume fraction of the dispersed Laves phase. In particular, the HEAs exhibited promising high-temperature mechanical performance, when heated to an elevated temperature of 1473 K (1200 °C), with a compressive fracture strength higher than 580 MPa without fracture at a strain of more than 20 pct. This study suggests that the present refractory HEAs have immense potential for engineering applications as a new class of high-temperature structural materials.

Basal cell carcinoma: CD56 and cytokeratin 5/6 staining patterns in the differential diagnosis with Merkel cell carcinoma.

PubMed

Panse, Gauri; McNiff, Jennifer M; Ko, Christine J

2017-06-01

Basal cell carcinoma (BCC) can resemble Merkel cell carcinoma (MCC) on histopathological examination and while CK20 is a useful marker in this differential, it is occasionally negative in MCC. CD56, a sensitive marker of neuroendocrine differentiation, is sometimes used to identify MCC, but has been reportedly variably positive in BCC as well. In contrast, CK5/6 consistently labels BCC but is not expressed in neuroendocrine tumors. We evaluated 20 cases of BCC for the pattern of CD56 and cytokeratin 5/6 (CK5/6) staining, hypothesizing that these 2 stains could differentiate BCC from MCC in difficult cases. Seventeen cases of MCC previously stained with CD56 were also examined. All BCCs showed patchy expression of CD56 except for 2 cases, which showed staining of greater than 70% of tumor. CK5/6 was diffusely positive in all cases of BCC. Fifteen of 17 MCCs were diffusely positive for CD56. The difference in the pattern of CD56 expression between MCC and BCC (diffuse vs patchy, respectively) was statistically significant (P < .05). BCC typically shows patchy CD56 expression and diffuse CK5/6 positivity. These 2 markers can be used to distinguish between BCC and MCC in challenging cases. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Involvement of matrix metalloproteinase-13 in stromal-cell-derived factor 1 alpha-directed invasion of human basal cell carcinoma cells.

PubMed

Chu, C-Y; Cha, S-T; Chang, C-C; Hsiao, C-H; Tan, C-T; Lu, Y-C; Jee, S-H; Kuo, M-L

2007-04-12

Basal cell carcinoma (BCC) is one of the most common skin neoplasms in humans and is usually characterized by local aggressiveness with little metastatic potential, although deep invasion, recurrence, and regional and distant metastases may occur. Here, we studied the mechanism of BCC invasion. We found that human BCC tissues and a BCC cell line had significant expression of CXCR4, which was higher in invasive than non-invasive BCC types. Further, of 19 recurrent tumors among 390 BCCs diagnosed during the past 12 years, 17/19 (89.5%) had high CXCR4 expression. We found that the CXCR4 ligand, stromal-cell-derived factor 1alpha (SDF-1alpha), directed BCC invasion and that this was mediated by time-dependent upregulation of mRNA expression and gelatinase activity of matrix metalloproteinase-13 (MMP-13). The transcriptional regulation of MMP-13 by SDF-1alpha was mediated by phosphorylation of extracellular signal-related kinase 1/2 and activation of the AP-1 component c-Jun. Finally, CXCR4-transfected BCC cells injected into nude mice induced aggressive BCCs that co-expressed CXCR4 and MMP-13. The identification of SDF-1alpha/CXCR4 as an important factor in BCC invasiveness may contribute insight into mechanisms involved in the aggressive potential of human BCC and may improve therapy for invasive BCCs.

Evaluate and Analysis Efficiency of Safaga Port Using DEA-CCR, BCC and SBM Models-Comparison with DP World Sokhna

NASA Astrophysics Data System (ADS)

Elsayed, Ayman; Shabaan Khalil, Nabil

2017-10-01

The competition among maritime ports is increasing continuously; the main purpose of Safaga port is to become the best option for companies to carry out their trading activities, particularly importing and exporting The main objective of this research is to evaluate and analyze factors that may significantly affect the levels of Safaga port efficiency in Egypt (particularly the infrastructural capacity). The assessment of such efficiency is a task that must play an important role in the management of Safaga port in order to improve the possibility of development and success in commercial activities. Drawing on Data Envelopment Analysis(DEA)models, this paper develops a manner of assessing the comparative efficiency of Safaga port in Egypt during the study period 2004-2013. Previous research for port efficiencies measurement usually using radial DEA models (DEA-CCR), (DEA-BCC), but not using non radial DEA model. The research applying radial - output oriented (DEA-CCR), (DEA-BCC) and non-radial (DEA-SBM) model with ten inputs and four outputs. The results were obtained from the analysis input and output variables based on DEA-CCR, DEA-BCC and SBM models, by software Max DEA Pro 6.3. DP World Sokhna port higher efficiency for all outputs were compared to Safaga port. DP World Sokhna position is below the southern entrance to the Suez Canal, on the Red Sea, Egypt, makes it strategically located to handle cargo transiting through one of the world's busiest commercial waterways.

Metastable Structural Phases of Metals in Columns IVB to Vib, and Rows 4 TO 6 OF the Periodic Table

NASA Astrophysics Data System (ADS)

Nnolim, Neme; Tyson, Trevor

2002-03-01

Total energy calculations as a function of strain along the <001> direction have been carried out for the bcc metals V, Nb, Ta, Cr, Mo and W, and the hcp metals Ti, Zr and Hf, all in the block of the periodic table defined by columns IVB to VIB, and rows 4 to 6. Since strain along the <001> direction corresponds to variation of the c lattice constant with respect to the a lattice constant, the total energy per unit cell has being calculated as a function of the c/a ratio. The highly accurate FP-LAPW (Full Potential Linearized Augmented Plane Wave) band structure method in the DFT (Density Functional Theory) formalism has been used for the calculations. In all cases except for the hcp column IVB elements, Zr, Hf and Ti, a metastable state was predicted from the calculations. Electronic properties are computed for all structures and are correlated with electrical and mechanical properties of metastable phases that have been observed experimentally. Properties of metastable phases, which were predicted in this work but which as of yet have not been observed experimentally, have also been predicted. Special attention is paid to the phases of tantalum and calculated transport properties are used to show that the observed high resistivity of the beta phase of tantalum relative to the alpha bcc phase cannot be explained solely by simple tetragonal distortions of the bcc phase.

Skin Cancer Chemoprevention by Silibinin: Mechanisms and Efficacy | Division of Cancer Prevention

Cancer.gov

Basal cell carcinoma (BCC), a non-melanoma skin cancer (NMSC) type, is a major health problem in the United States (US); annual BCC incidences alone are higher than all other cancer incidences combined (1.67 million/year). Most BCC cases are curable by surgery/radiation, but these can be painful and highly disfiguring and are not viable treatment options for BCC patients with

Diagnostic value of CD10 and Bcl2 expression in distinguishing cutaneous basal cell carcinoma from squamous cell carcinoma and seborrheic keratosis.

PubMed

Gaballah, Mohammad A; Ahmed, Rehab-Allah

2015-12-01

The distinction between cutaneous basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and seborrheic keratosis (SK), which are common entities in clinical practice, can be difficult clinically and histologically. CD10 and Bcl2 antigens are important factors in tumor growth, survival and spread. The aim of the present study is to define the frequency of CD10 and Bcl2 expression in such cutaneous tumors and its relation to the clinicopathological characteristics as well as their possible diagnostic utility. CD10 and Bcl2 immunohistochemistry was performed on 30 BCC, 20 SCC and 15 SK. 93.3% of SK cases and 53.3% of BCC cases showed significant expression of CD10 in tumor cells when compared either with each other or with SCC cases (100% negative). Stromal CD10 expression was positive in 50% of BCC cases and 75% of SCC cases. Stromal CD10 expression was significantly higher in high risk BCC and BCC with infiltrating deep margins; furthermore, it showed a significant positive correlation with grade of SCC. A significant inverse correlation between CD10 expression in stromal and tumor cells of BCC was present. Bcl2 was significantly expressed in 93.3% of SK cases and 80% of BCC cases when compared with SCC cases (100% negative). It was found that for distinguishing BCC from SK, only CD10 expression in tumor cells provided a high diagnostic value with positive likelihood ratio (PLR) was 7.00. In addition, CD10 and Bcl2 expression in tumor cells could give convincing diagnostic value to distinguish SCC from SK (PLR=15.00 for each marker). Moreover, for differentiating BCC from SCC, only Bcl2 in the tumor cells could provide a high diagnostic value (PLR=5.5). In conclusion, CD10 and Bcl2 can help in differentiating cutaneous BCC from SK and SCC. The overexpression of CD10 in the stromal cells of SCC and some variants of BCC suggests the invasive properties of such tumors. Copyright © 2015 Elsevier GmbH. All rights reserved.

Lattice softening in body-centered-cubic lithium-magnesium alloys

NASA Astrophysics Data System (ADS)

Winter, I. S.; Tsuru, T.; Chrzan, D. C.

2017-08-01

A first-principles investigation of the influence of lattice softening on lithium-magnesium alloys near the body-centered-cubic (bcc)/hexagonal close-packed (hcp) transition composition is presented. Results show that lithium-magnesium alloys display a softening of the shear modulus C11-C12 , and an acoustic phonon branch between the Γ and N high symmetry points, as the composition approaches the stability limit for the bcc phase. This softening is accompanied by an increase in the size of the dislocation core region. Ideal tensile strength calculations predict that ordered phases of lithium-magnesium alloys are intrinsically brittle. Methods to make the alloys more ductile are discussed, and the propensity for these alloys to display gum-metal-like behavior is assessed.

Targeting the Bacterial Cytoskeleton of the Burkholderia cepacia Complex for Antimicrobial Development: A Cautionary Tale.

PubMed

Carnell, Sonya C; Perry, John D; Borthwick, Lee; Vollmer, Daniela; Biboy, Jacob; Facchini, Marcella; Bragonzi, Alessandra; Silipo, Alba; Vergunst, Annette C; Vollmer, Waldemar; Khan, Anjam C M; De Soyza, Anthony

2018-05-30

Burkholderia cepacia complex (BCC) bacteria are a group of opportunistic pathogens that cause severe lung infections in cystic fibrosis (CF). Treatment of BCC infections is difficult, due to the inherent and acquired multidrug resistance of BCC. There is a pressing need to find new bacterial targets for antimicrobials. Here, we demonstrate that the novel compound Q22, which is related to the bacterial cytoskeleton destabilising compound A22, can reduce the growth rate and inhibit growth of BCC bacteria. We further analysed the phenotypic effects of Q22 treatment on BCC virulence traits, to assess its feasibility as an antimicrobial. BCC bacteria were grown in the presence of Q22 with a broad phenotypic analysis, including resistance to H₂O₂-induced oxidative stress, changes in the inflammatory potential of cell surface components, and in-vivo drug toxicity studies. The influence of the Q22 treatment on inflammatory potential was measured by monitoring the cytokine responses of BCC whole cell lysates, purified lipopolysaccharide, and purified peptidoglycan extracted from bacterial cultures grown in the presence or absence of Q22 in differentiated THP-1 cells. BCC bacteria grown in the presence of Q22 displayed varying levels of resistance to H₂O₂-induced oxidative stress, with some strains showing increased resistance after treatment. There was strain-to-strain variation in the pro-inflammatory ability of bacterial lysates to elicit TNFα and IL-1β from human myeloid cells. Despite minimal toxicity previously shown in vitro with primary CF cell lines, in-vivo studies demonstrated Q22 toxicity in both zebrafish and mouse infection models. In summary, destabilisation of the bacterial cytoskeleton in BCC, using compounds such as Q22, led to increased virulence-related traits in vitro. These changes appear to vary depending on strain and BCC species. Future development of antimicrobials targeting the BCC bacterial cytoskeleton may be hampered if such effects translate into the in-vivo environment of the CF infection.

PTCH1 gene haplotype association with basal cell carcinoma after transplantation.

PubMed

Begnini, A; Tessari, G; Turco, A; Malerba, G; Naldi, L; Gotti, E; Boschiero, L; Forni, A; Rugiu, C; Piaserico, S; Fortina, A B; Brunello, A; Cascone, C; Girolomoni, G; Gomez Lira, M

2010-08-01

Basal cell carcinoma (BCC) is 10 times more frequent in organ transplant recipients (OTRs) than in the general population. Factors in OTRs conferring increased susceptibility to BCC include ultraviolet radiation exposure, immunosuppression, viral infections such as human papillomavirus, phototype and genetic predisposition. The PTCH1 gene is a negative regulator of the hedgehog pathway, that provides mitogenic signals to basal cells in skin. PTCH1 gene mutations cause naevoid BCC syndrome, and contribute to the development of sporadic BCC and other types of cancers. Associations have been reported between PTCH1 polymorphisms and BCC susceptibility in nontransplanted individuals. To search for novel common polymorphisms in the proximal 5' regulatory region upstream of PTCH1 gene exon 1B, and to investigate the possible association of PTCH1 polymorphisms and haplotypes with BCC risk after organ transplantation. Three PTCH1 single nucleotide polymorphisms (rs2297086, rs2066836 and rs357564) were analysed by restriction fragment length polymorphism analysis in 161 northern Italian OTRs (56 BCC cases and 105 controls). Two regions of the PTCH1 gene promoter were screened by heteroduplex analysis in 30 cases and 30 controls. Single locus analysis showed no significant association. Haplotype T(1686)-T(3944) appeared to confer a significantly higher risk for BCC development (odds ratio 2.98, 95% confidence interval 2.55-3.48; P = 0.001). Two novel rare polymorphisms were identified at positions 176 and 179 of the 5'UTR. Two novel alleles of the -4 (CGG)(n) microsatellite were identified. No association of this microsatellite with BCC was observed. Haplotypes containing T(1686)-T(3944) alleles were shown to be associated with an increased BCC risk in our study population. These data appear to be of great interest for further investigations in a larger group of transplant individuals. Our results do not support the hypothesis that common polymorphisms in the proximal 5' regulatory region of the PTCH1 gene could represent an important risk factor for BCC after organ transplantation.

Phase Transformation and Aging Behavior of Al0.5CoCrFeNiSi0.2 High-Entropy Alloy

NASA Astrophysics Data System (ADS)

Zhang, C.; Wu, G. F.; Dai, P. Q.

2015-05-01

An Al0.5CoCrFeNiSi0.2 high-entropy alloy was prepared by vacuum arc melting. The alloy was aged from 700 to 1100 °C. The effects of aging on the phase transformation and mechanical performances were explored. The as-cast alloy showed a dendritic (DR) microstructure. The DR region was an Fe,Cr-rich FCC phase, while the interdendritic (ID) region was a spinodal structure composed of Fe,Cr-rich BCC (A2) and Ni,Al-rich BCC (B2) phases. At aging temperatures between 700 and 900 °C, the Fe,Cr-rich BCC (A2) phase in the ID region transformed into σ and Fe,Cr-rich FCC phases. Meanwhile, some Ni,Al-rich FCC phase particles precipitated from the DR region. During aging at 1100 °C, the DR microstructure disappeared, and a microstructure composed of Fe,Cr-rich FCC and Ni,Al-rich BCC (B2) phases both possessing a lamellar shape was developed. The alloy exhibited evident hardening and lower tensile strain when the aging temperature was lower than 1000 °C, which was mainly attributed to the generation of the σ phase in the ID region. However, a contrasting behavior was observed when the aging temperature was higher than 1000 °C, which was attributed to the redissolution of the σ phase and the microstructure coarsening.

Physical metallurgy of metastable Bcc lanthanide-magnesium alloys for R = La, Gd, and Dy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Herchenroeder, J.W.; Manfrinetti, P.; Gschneidner, K.A. Jr.

1989-09-01

Bcc La-Mg, Gd-Mg, and Dy-Mg alloys have been prepared by an ice water/acetone quench from liquid melts. Single-phase alloys could be retained in a window around the eutectoid composition: 13 to 22 at. pct Mg, 23.6 to 29 at. pct Mg, and 27 to 29 at. pct Mg for La, Gd, and Dy alloys, respectively. At the center of the windows, x-ray diffraction peaks are extremely sharp as in equilibrium bcc structures; however, as alloy composition is moved away from the eutectoid, line broadening is observed. Reversion of the bcc phase to the equilibrium microstructure for R-Mg alloys (R =more » La, Gd, or Dy) has been characterized by differential thermal analysis (DTA) or differential scanning calorimetry (DSC) and isothermal annealing. La-Mg alloys revert directly to {alpha}La (dhcp) + LaMg at about 350{degrees}C when heated at 10{degrees}C/min. In contrast, the Gd and Dy alloys revert by a two-step process: first, a transition to an intermediate distorted hcp phase between 300{degrees}C and 400{degrees}C, and, second, the relaxation of this phase to {alpha}R (hcp) + RMg at about 490{degrees}C when heated at 10{degrees}C/min. Isothermal annealing and high temperature x-ray diffraction confirm the nature of these reactions.« less

Combined Molecular and Spin Dynamics Simulation of Lattice Vacancies in BCC Iron

NASA Astrophysics Data System (ADS)

Mudrick, Mark; Perera, Dilina; Eisenbach, Markus; Landau, David P.

Using an atomistic model that treats translational and spin degrees of freedom equally, combined molecular and spin dynamics simulations have been performed to study dynamic properties of BCC iron at varying levels of defect impurity. Atomic interactions are described by an empirical many-body potential, and spin interactions with a Heisenberg-like Hamiltonian with a coordinate dependent exchange interaction. Equations of motion are solved numerically using the second-order Suzuki-Trotter decomposition for the time evolution operator. We analyze the spatial and temporal correlation functions for atomic displacements and magnetic order to obtain the effect of vacancy defects on the phonon and magnon excitations. We show that vacancy clusters in the material cause splitting of the characteristic transverse spin-wave excitations, indicating the production of additional excitation modes. Additionally, we investigate the coupling of the atomic and magnetic modes. These modes become more distinct with increasing vacancy cluster size. This material is based upon work supported by the U.S. Department of Energy Office of Science Graduate Student Research (SCGSR) program.

Histologic Mimics of Basal Cell Carcinoma.

PubMed

Stanoszek, Lauren M; Wang, Grace Y; Harms, Paul W

2017-11-01

- Basal cell carcinoma (BCC) is the most common human malignant neoplasm and is a frequently encountered diagnosis in dermatopathology. Although BCC may be locally destructive, it rarely metastasizes. Many diagnostic entities display morphologic and immunophenotypic overlap with BCC, including nonneoplastic processes, such as follicular induction over dermatofibroma; benign follicular tumors, such as trichoblastoma, trichoepithelioma, or basaloid follicular hamartoma; and malignant tumors, such as sebaceous carcinoma or Merkel cell carcinoma. Thus, misdiagnosis has significant potential to result in overtreatment or undertreatment. - To review key features distinguishing BCC from histologic mimics, including current evidence regarding immunohistochemical markers useful for that distinction. - Review of pertinent literature on BCC immunohistochemistry and differential diagnosis. - In most cases, BCC can be reliably diagnosed by histopathologic features. Immunohistochemistry may provide useful ancillary data in certain cases. Awareness of potential mimics is critical to avoid misdiagnosis and resulting inappropriate management.

Occupation and keratinocyte cancer risk: a population-based case-control study.

PubMed

Marehbian, Josh; Colt, Joanne S; Baris, Dalsu; Stewart, Patricia; Stukel, Therese A; Spencer, Steven K; Karagas, Margaret R

2007-10-01

The aim of our study was to identify occupations associated with increased risk of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). We conducted a population-based case-control study of BCC and SCC in New Hampshire. Cases (n = 599 BCC, n = 290 SCC) and controls (n = 524) completed a self-administered residence and work history questionnaire and personal interview regarding major risk factors for skin cancer. Reported jobs were coded using the Standardized Occupational Classification system (SOC). Odds ratios (ORs) and confidence intervals (CIs) for BCC and SCC were calculated for men and women separately using unconditional logistic regression models taking into account age, education, skin reaction to sun, history of painful sunburns, time spent outdoors, and for SCC, smoking. Among men, we observed elevated risks of both BCC and SCC among groundskeepers and gardeners, except farm (SOC 5622). We also found that garage and service station-related occupations (SOCs 873) and to some extent food/beverage preparation/service occupations (SOC 521) were associated with BCC risk among men. Women in health services occupations (SOC 523) had elevated risks for both tumors, especially for BCC. Additionally, administrative support (SOC 46/47) occupations were related to BCC risk among women. Other occupations were associated with excess risks, but without consistent trends by duration of employment. We observed several occupations associated with elevated BCC and SCC risk. These results resemble reported findings for cutaneous melanoma and are generally consistent with the few available studies on keratinocyte cancers.

Spatiotemporal variation of bacterial community composition and possible controlling factors in tropical shallow lagoons.

PubMed

Laque, Thaís; Farjalla, Vinicius F; Rosado, Alexandre S; Esteves, Francisco A

2010-05-01

Bacterial community composition (BCC) has been extensively related to specific environmental conditions. Tropical coastal lagoons present great temporal and spatial variation in their limnological conditions, which, in turn, should influence the BCC. Here, we sought for the limnological factors that influence, in space and time, the BCC in tropical coastal lagoons (Rio de Janeiro State, Brazil). The Visgueiro lagoon was sampled monthly for 1 year and eight lagoons were sampled once for temporal and spatial analysis, respectively. BCC was evaluated by bacteria-specific PCR-DGGE methods. Great variations were observed in limnological conditions and BCC on both temporal and spatial scales. Changes in the BCC of Visgueiro lagoon throughout the year were best related to salinity and concentrations of NO (3) (-) , dissolved phosphorus and chlorophyll-a, while changes in BCC between lagoons were best related to salinity and dissolved phosphorus concentration. Salinity has a direct impact on the integrity of the bacterial cell, and it was previously observed that phosphorus is the main limiting nutrient to bacterial growth in these lagoons. Therefore, we conclude that great variations in limnological conditions of coastal lagoons throughout time and space resulted in different BCCs and salinity and nutrient concentration, particularly dissolved phosphorus, are the main limnological factors influencing BCC in these tropical coastal lagoons.

Medicare claims data reliably identify treatments for basal cell carcinoma and squamous cell carcinoma: a prospective cohort study.

PubMed

Thompson, Bridie S; Olsen, Catherine M; Subramaniam, Padmini; Neale, Rachel E; Whiteman, David C

2016-04-01

To investigate the accuracy of Medical Benefit Schedule (MBS) item numbers to identify treatments for basal cell carcinomas (BCC) and squamous cell carcinomas (SCC). We linked records from QSkin Study participants (n=37,103) to Medicare. We measured the proportion of Medicare claims for primary excision of BCC/SCC that had corresponding claims for histopathology services. In subsets of participants, we estimated the sensitivity and external concordance of MBS item numbers for identifying BCC/SCC diagnoses by comparing against 'gold-standard' histopathology reports. A total of 2,821 (7.6%) participants had 4,830 separate Medicare claims for BCC/SCC excision; almost all (97%) had contemporaneous Medicare claims for histopathology services. Among participants with BCC/SCC confirmed by histology reports, 76% had a corresponding Medicare claim for primary surgical excision of BCC/SCC. External concordance for Medicare claims for primary BCC/SCC excision was 68%, increasing to 97% when diagnoses for intra-epidermal carcinomas and keratoacanthomas were included. MBS item numbers for primary excision of BCC/SCC are reasonably reliable for determining incident cases of keratinocyte skin cancers, but may underestimate incidence by up to 24%. Medicare claims data may have utility in monitoring trends in conditions for which there is no mandatory reporting. © 2015 Public Health Association of Australia.

Basal cell carcinoma of the vulva: a case series.

PubMed

Mulvany, Nicholas J; Rayoo, Mukta; Allen, David G

2012-10-01

To review the diagnostic features and characteristics of an uncommon tumour, basal cell carcinoma (BCC) of the vulva. The clinical and pathological details of six vulvar BCCs were reviewed. Four of the BCCs arose in isolation, one was combined with vulvar Paget's disease and another was intimately associated with a poorly differentiated squamous cell carcinoma. The average age of the six patients was 76 years (75 years for 'isolated' BCC; 78 years for BCC 'mixed' with other lesions). The duration of symptoms averaged 13 months in 'isolated' BCC but 24 months in 'mixed' BCC. Vulvar pruritus was the most common presenting complaint in the four cases of 'isolated' BCC. The initial biopsies included shave (× 2) or punch biopsies (× 4). Definitive surgery included excisional biopsy (× 2) or a wide local excision (× 3). In the five assessable tumours, the maximum tumour diameter averaged 19.8 mm (range 11-36 mm). In the sixth patient the BCC was contiguous with a 70 mm, unresectable, poorly differentiated squamous cell carcinoma which was treated by radiotherapy alone. : Although the histological diagnosis of vulvar BCC was straightforward in some of our cases, others presented difficulties due to non-representative initial biopsies, insufficient clinical information or contiguity with lesions of greater clinical significance such as Paget's disease or squamous cell carcinoma.

Profile of vismodegib and its potential in the treatment of advanced basal cell carcinoma.

PubMed

Macha, Muzafar A; Batra, Surinder K; Ganti, Apar Kishor

2013-01-01

Basal cell carcinoma (BCC) is the most common human malignancy. Recent advances in our understanding of the critical biologic pathways implicated in the development and progression of BCC have led to the development of the first molecular targeted therapy for this disease. The hedgehog pathway is mutated in virtually all patients with BCC and recent trials with vismodegib, an inhibitor of this pathway, have shown significant responses. This review will discuss the importance of the hedgehog pathway in the pathogenesis of BCC and describe in detail the pharmacology of vismodegib in relation to its activity in advanced BCC.

Profile of vismodegib and its potential in the treatment of advanced basal cell carcinoma

PubMed Central

Macha, Muzafar A; Batra, Surinder K; Ganti, Apar Kishor

2013-01-01

Basal cell carcinoma (BCC) is the most common human malignancy. Recent advances in our understanding of the critical biologic pathways implicated in the development and progression of BCC have led to the development of the first molecular targeted therapy for this disease. The hedgehog pathway is mutated in virtually all patients with BCC and recent trials with vismodegib, an inhibitor of this pathway, have shown significant responses. This review will discuss the importance of the hedgehog pathway in the pathogenesis of BCC and describe in detail the pharmacology of vismodegib in relation to its activity in advanced BCC. PMID:23940421

Immunosuppressive Environment in Basal Cell Carcinoma: The Role of Regulatory T Cells.

PubMed

Omland, Silje H; Nielsen, Patricia S; Gjerdrum, Lise M R; Gniadecki, Robert

2016-11-02

Interaction between tumour survival tactics and anti-tumour immune response is a major determinant for cancer growth. Regulatory T cells (T-regs) contribute to tumour immune escape, but their role in basal cell carcinoma (BCC) is not understood. The fraction of T-regs among T cells was analysed by immunohistochemistry followed by automated image analysis in facial BCC, peritumoural skin and normal, buttock skin. Quantitative real-time PCR (qRT-PCR) was performed for FOXP3 and cytokines involved in T-reg attraction and T-cell activation. T-regs comprised 45% of CD4-cells surrounding BCC. FOXP3 was highly expressed in BCC, but absent in buttock skin. Unexpectedly, expression of FOXP3 was increased in peritumoural skin, with the FOXP3/CD3 fractions exceeding those of BCC (p?=?0.0065). Transforming growth factor (TGF)-? and T-reg chemokine expression was increased in BCC and peritumoural skin, but not in buttock skin, with expression levels correlating with FOXP3. T-regs are abundantly present both in BCC and in peritumoural skin, mediating an immunosuppressed microenvironment permissive for skin cancer.

Martensitic Transformation in a β-Type Mg-Sc Alloy

NASA Astrophysics Data System (ADS)

Ogawa, Yukiko; Ando, Daisuke; Sutou, Yuji; Somekawa, Hidetoshi; Koike, Junichi

2018-03-01

Recently, we found that a Mg-Sc alloy with a bcc (β) phase exhibits superelasticity and a shape memory effect at low temperature. In this work, we examined the stress-induced and thermally induced martensitic transformation of the β-type Mg-Sc alloy and investigated the crystal structure of the thermally induced martensite phase based on in situ X-ray diffraction (XRD) measurements. The lattice constants of the martensite phase were calculated to be a = 0.3285 nm, b = 0.5544 nm, and c = 0.5223 nm when we assumed that the martensite phase has an orthorhombic structure (Cmcm). Based on the lattice correspondence between a bcc and an orthorhombic structures such as that in the case of β-Ti shape memory alloys, we estimated the transformation strain of the β Mg-Sc alloy. As a result, the transformation strains along the 001, 011, and 111 directions in the β phase were calculated to be + 5.7, + 8.8, and + 3.3%, respectively.

Chemical vapor deposition of high T sub c superconductors

NASA Technical Reports Server (NTRS)

Webb, G. W.; Engelhardt, J. J.

1978-01-01

The results are reported of an investigation into the synthesis and properties of high temperature superconducting materials. A chemical vapor deposition apparatus was designed and built which is suitable for the preparation of multicomponent metal films This apparatus was used to prepare a series of high T sub c A-15 structure superconducting films in the binary system Nb-Ge. The effect on T sub c of a variety of substrate materials was investigated. An extensive series of ternary alloys were also prepared. Conditions allowing the brittle high T sub c (approximately 18 K) A-15 structure superconductor Nb3A1 to be prepared in a low T sub c but ductile form were found. Some of the ways that the ductile (bcc) form can be cold worked or machined are described. Measurements of rate of transformation of cold worked bcc material to the high T sub c A-15 structure with low temperature annealing are given. Preliminary measurements indicate that this material has attractive high field critical current densities.

Direct Observation on Spin-Coating Process of PS- b -P2VP Thin Films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ogawa, Hiroki; Takenaka, Mikihito; Miyazaki, Tsukasa

We studied the structural development of symmetric poly(styrene-b-2-vinylpyridine) (PS-b-P2VP) block copolymers during spin-coating using in situ grazing incidence small angle X-ray scattering (GISAXS) measurements. During the spin-coating process, after the formation of the micelles in dilute solution, the selective solvent induced two kinds of the morphological transition. Firstly, the disordered spherical micelles were transformed into a BCC lattice of spheres of which the (110) plane was oriented perpendicularly to the substrate surface. Secondly, further evaporation induced a transition from spheres on the BCC lattice into cylindrical structures. The orientation of the cylinders perpendicular to the substrate surface was induced bymore » solvent convection perpendicular to the substrate, which occurs during rapid solvent evaporation. After this transition, vitrification of PS and P2VP prevented any further transition from cylinders to the more thermodynamically stable lamellar structures, as are generally observed as the bulk equilibrium state.« less

Study on dependence of dose enhancement on cluster morphology of gold nanoparticles in radiation therapy using a body-centred cubic model.

PubMed

Ahn, Sang Hee; Chung, Kwangzoo; Shin, Jung Wook; Cheon, Wonjoong; Han, Youngyih; Park, Hee Chul; Choi, Doo Ho

2017-09-15

Gold nanoparticles (GNPs) injected in a body for dose enhancement in radiation therapy are known to form clusters. We investigated the dependence of dose enhancement on the GNP morphology using Monte-Carlo simulations and compared the model predictions with experimental data. The cluster morphology was approximated as a body-centred cubic (BCC) structure by placing GNPs at the 8 corners and the centre of a cube with an edge length of 0.22-1.03 µm in a 4  ×  4  ×  4 µm 3 water-filled phantom. We computed the dose enhancement ratio (DER) for 50 and 260 kVp photons as a function of the distance from the cube centre for 12 different cube sizes. A 10 nm-wide concentric shell shaped detector was placed up to 100 nm away from a GNP at the cube centre. For model validation, simulations based on BCC and nanoparticle random distribution (NRD) models were performed using parameters that corresponded to the experimental conditions, which measured increases in the relative biological effect due to GNPs. We employed the linear quadratic model to compute cell surviving fraction (SF) and sensitizer enhancement ratio (SER). The DER is inversely proportional to the distance to the GNPs. The largest DERs were 1.97 and 1.80 for 50 kVp and 260 kVp photons, respectively. The SF predicted by the BCC model agreed with the experimental value within 10%, up to a 5 Gy dose, while the NRD model showed a deviation larger than 10%. The SERs were 1.21  ±  0.13, 1.16  ±  0.11, and 1.08  ±  0.11 according to the experiment, BCC, and NRD models, respectively. We most accurately predicted the GNP radiosensitization effect using the BCC approximation and suggest that the BCC model is effective for use in nanoparticle dosimetry.

Study on dependence of dose enhancement on cluster morphology of gold nanoparticles in radiation therapy using a body-centred cubic model

NASA Astrophysics Data System (ADS)

Ahn, Sang Hee; Chung, Kwangzoo; Shin, Jung Wook; Cheon, Wonjoong; Han, Youngyih; Park, Hee Chul; Choi, Doo Ho

2017-10-01

Gold nanoparticles (GNPs) injected in a body for dose enhancement in radiation therapy are known to form clusters. We investigated the dependence of dose enhancement on the GNP morphology using Monte-Carlo simulations and compared the model predictions with experimental data. The cluster morphology was approximated as a body-centred cubic (BCC) structure by placing GNPs at the 8 corners and the centre of a cube with an edge length of 0.22-1.03 µm in a 4  ×  4  ×  4 µm3 water-filled phantom. We computed the dose enhancement ratio (DER) for 50 and 260 kVp photons as a function of the distance from the cube centre for 12 different cube sizes. A 10 nm-wide concentric shell shaped detector was placed up to 100 nm away from a GNP at the cube centre. For model validation, simulations based on BCC and nanoparticle random distribution (NRD) models were performed using parameters that corresponded to the experimental conditions, which measured increases in the relative biological effect due to GNPs. We employed the linear quadratic model to compute cell surviving fraction (SF) and sensitizer enhancement ratio (SER). The DER is inversely proportional to the distance to the GNPs. The largest DERs were 1.97 and 1.80 for 50 kVp and 260 kVp photons, respectively. The SF predicted by the BCC model agreed with the experimental value within 10%, up to a 5 Gy dose, while the NRD model showed a deviation larger than 10%. The SERs were 1.21  ±  0.13, 1.16  ±  0.11, and 1.08  ±  0.11 according to the experiment, BCC, and NRD models, respectively. We most accurately predicted the GNP radiosensitization effect using the BCC approximation and suggest that the BCC model is effective for use in nanoparticle dosimetry.

Depletion of cutaneous macrophages and dendritic cells promotes growth of basal cell carcinoma in mice.

PubMed

König, Simone; Nitzki, Frauke; Uhmann, Anja; Dittmann, Kai; Theiss-Suennemann, Jennifer; Herrmann, Markus; Reichardt, Holger M; Schwendener, Reto; Pukrop, Tobias; Schulz-Schaeffer, Walter; Hahn, Heidi

2014-01-01

Basal cell carcinoma (BCC) belongs to the group of non-melanoma skin tumors and is the most common tumor in the western world. BCC arises due to mutations in the tumor suppressor gene Patched1 (Ptch). Analysis of the conditional Ptch knockout mouse model for BCC reveals that macrophages and dendritic cells (DC) of the skin play an important role in BCC growth restraining processes. This is based on the observation that a clodronate-liposome mediated depletion of these cells in the tumor-bearing skin results in significant BCC enlargement. The depletion of these cells does not modulate Ki67 or K10 expression, but is accompanied by a decrease in collagen-producing cells in the tumor stroma. Together, the data suggest that cutaneous macrophages and DC in the tumor microenvironment exert an antitumor effect on BCC.

Impediments to media communication of social change in family planning and reproductive health: experiences from East Africa.

PubMed

Kagurusi, Patrick T

2013-09-01

The media has been employed to increase uptake of Family Planning through behaviour change communication (BCC). Understanding the barriers encountered in effectively undertaking this function would increase the strategy's effectiveness. Sixty journalists from East Africa participated in trainings to enhance their BCC skills for Family Planning in which a qualitative study was nested to identify barriers to effective Family Planning BCC in the region's media. The barriers were observed to be insufficient BCC skills, journalists' conflict of interest, interests of media houses, inaccessible sources of family planning information, editorial ideologies and absence of commercially beneficial demand. Coupled with the historical ideologies of the media in the region, the observed barriers have precipitated ineffective family planning BCC in the regions media. Effective BCC for family planning in the regions media requires capacity building among practitioners and alignment of the concept to the media's and consumers' aspirations.

Durable pd-based alloy and hydrogen generation membrane thereof

DOEpatents

Benn, Raymond C.; Opalka, Susanne M.; Vanderspurt, Thomas Henry

2010-02-02

A durable Pd-based alloy is used for a H.sub.2-selective membrane in a hydrogen generator, as in the fuel processor of a fuel cell plant. The Pd-based alloy includes Cu as a binary element, and further includes "X", where "X" comprises at least one metal from group "M" that is BCC and acts to stabilize the .beta. BCC phase for stability during operating temperatures. The metal from group "M" is selected from the group consisting of Fe, Cr, Nb, Ta, V, Mo, and W, with Nb and Ta being most preferred. "X" may further comprise at least one metal from a group "N" that is non-BCC, preferably FCC, that enhances other properties of the membrane, such as ductility. The metal from group "N" is selected from the group consisting of Ag, Au, Re, Ru, Rh, Y, Ce, Ni, Ir, Pt, Co, La and In. The at. % of Pd in the binary Pd--Cu alloy ranges from about 35 at. % to about 55 at. %, and the at. % of "X" in the higher order alloy, based on said binary alloy, is in the range of about 1 at. % to about 15 at. %. The metals are selected according to a novel process.

The 12-month analysis from Basal Cell Carcinoma Outcomes with LDE225 Treatment (BOLT): A phase II, randomized, double-blind study of sonidegib in patients with advanced basal cell carcinoma.

PubMed

Dummer, Reinhard; Guminski, Alexander; Gutzmer, Ralf; Dirix, Luc; Lewis, Karl D; Combemale, Patrick; Herd, Robert M; Kaatz, Martin; Loquai, Carmen; Stratigos, Alexander J; Schulze, Hans-Joachim; Plummer, Ruth; Gogov, Sven; Pallaud, Celine; Yi, Tingting; Mone, Manisha; Chang, Anne Lynn S; Cornélis, Frank; Kudchadkar, Ragini; Trefzer, Uwe; Lear, John T; Sellami, Dalila; Migden, Michael R

2016-07-01

The hedgehog pathway inhibitor sonidegib demonstrated meaningful tumor shrinkage in more than 90% of patients with locally advanced basal cell carcinoma (BCC) or metastatic BCC in the BCC Outcomes with LDE225 Treatment study. This report provides long-term follow-up data collected up to 12 months after the last patient was randomized. In this multicenter, randomized, double-blind phase II study, patients were randomized 1:2 to sonidegib 200 or 800 mg. The primary end point was objective response rate assessed by central review. Objective response rates in the 200- and 800-mg arms were 57.6% and 43.8% in locally advanced BCC and 7.7% and 17.4% in metastatic BCC, respectively. Among the 94 patients with locally advanced BCC who responded, only 18 progressed or died and more than 50% had responses lasting longer than 6 months. In addition, 4 of 5 responders with metastatic BCC maintained an objective response. Grade 3/4 adverse events and those leading to discontinuation were less frequent with sonidegib 200 versus 800 mg (38.0% vs 59.3%; 27.8% vs 37.3%, respectively). No placebo or comparator arms were used because sonidegib demonstrated efficacy in advanced BCC in a phase I study, and the hedgehog pathway inhibitor vismodegib was not yet approved. With longer follow-up, sonidegib demonstrated sustained tumor responses in patients with advanced BCC. Copyright © 2016 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

Photonic band gap templating using optical interference lithography

NASA Astrophysics Data System (ADS)

Chan, Timothy Y. M.; Toader, Ovidiu; John, Sajeev

2005-04-01

We describe the properties of three families of inversion-symmetric, large photonic band-gap (PBG) template architectures defined by iso-intensity surfaces in four beam laser interference patterns. These templates can be fabricated by optical interference (holographic) lithography in a suitable polymer photo-resist. PBG materials can be synthesized from these templates using two stages of infiltration and inversion, first with silica and second with silicon. By considering point and space group symmetries to produce laser interference patterns with the smallest possible irreducible Brillouin zones, we obtain laser beam intensities, directions, and polarizations which generate a diamond-like (fcc) crystal, a novel body-centered cubic (bcc) architecture, and a simple-cubic (sc) structure. We obtain laser beam parameters that maximize the intensity contrasts of the interference patterns. This optimizes the robustness of the holographic lithography to inhomogeneity in the polymer photo-resist. When the optimized iso-intensity surface defines a silicon to air boundary (dielectric contrast of 11.9 to 1), the fcc, bcc, and sc crystals have PBG to center frequency ratios of 25%, 21%, and 11%, respectively. A full PBG forms for the diamond-like crystal when the refractive index contrast exceeds 1.97 to 1. We illustrate a noninversion symmetric PBG architecture that interpolates between a simple fcc structure and a diamond network structure. This crystal exhibits two distinct and complete photonic band gaps. We also describe a generalized class of tetragonal photonic crystals that interpolate between and extrapolate beyond the diamond-like crystal and the optimized bcc crystal. We demonstrate the extent to which the resulting PBG materials are robust against perturbations to the laser beam amplitudes and polarizations, and template inhomogeneity. The body centered cubic structure exhibits the maximum robustness overall.

Effect of spin-orbit interactions on the structural stability, thermodynamic properties, and transport properties of lead under pressure

NASA Astrophysics Data System (ADS)

Smirnov, N. A.

2018-03-01

The paper investigates the role of spin-orbit interaction in the prediction of structural stability, lattice dynamics, elasticity, thermodynamic and transport properties (electrical resistivity and thermal conductivity) of lead under pressure with the FP-LMTO (full-potential linear-muffin-tin orbital) method for the first-principles band structure calculations. Our calculations were carried out for three polymorphous lead modifications (fcc, hcp, and bcc) in generalized gradient approximation with the exchange-correlation functional PBEsol. They suggest that compared to the scalar-relativistic calculation, the account for the SO effects insignificantly influences the compressibility of Pb. At the same time, in the calculation of phonon spectra and transport properties, the role of SO interaction is important, at least, for P ≲150 GPa. At higher pressures, the contribution from SO interaction reduces but not vanishes. As for the relative structural stability, our studies show that SO effects influence weakly the pressure of the fcc →hcp transition and much higher the pressure of the hcp →bcc transition.

Predictive variables for the biological behaviour of basal cell carcinoma of the face: relevance of morphometry of the nuclei.

PubMed

Appel, T; Bierhoff, E; Appel, K; von Lindern, J-J; Bergé, S; Niederhagen, B

2003-06-01

We did a morphometric analysis of 130 histological sections of basal cell carcinoma (BCC) of the face to find out whether morphometric variables in the structure of the nuclei of BCC cells could serve as predictors of the biological behaviour. We considered the following variables: maximum and minimum diameters, perimeter, nuclear area and five form factors that characterise and quantify the shape of a structure (axis ratio, shape factor, nuclear contour index, nuclear roundness and circumference ratio). We did a statistical analysis of primary and recurring tumours and four histology-based groups (multifocal superficial BCCs, nodular BCCs, sclerosing BCCs and miscellaneous forms) using a two-sided t test for independent samples. Multifocal superficial BCCs showed significantly smaller values for the directly measured variables (maximum and minimum diameters, perimeter and nuclear area). Morphometry could not distinguish between primary and recurring tumours.

An outbreak of Burkholderia cepacia complex in the paediatric unit of a tertiary care hospital.

PubMed

Mali, Swapna; Dash, Lona; Gautam, Vikas; Shastri, Jayanthi; Kumar, Sunil

2017-01-01

Burkholderia cepacia complex (Bcc) has emerged as a serious nosocomial pathogen worldwide especially in patients with indwelling catheters and cystic fibrosis. Bcc is a common contaminant of pharmaceutical products. We describe an outbreak of Bcc bacteraemia amongst children admitted in Paediatric Intensive Care Unit (PICU) and paediatric ward at a tertiary care hospital, Mumbai, in Western India. Blood culture samples from paediatric patients yielded growth of non-fermenting, oxidase positive, motile, Gram negative bacilli (NFGNB) (76/909) over a period of 8 months. Based on conventional biochemical tests and antimicrobial susceptibility testing, these isolates were provisionally identified as Bcc. The increased, repeated and continued isolation of Bcc alerted the possibility of an outbreak confined to PICU and paediatric ward. Active surveillance was undertaken to trace the source and contain the outbreak. Isolates were subjected to recA polymerase chain reaction (PCR) and Expanded multilocus sequence typing (EMLST). Surveillance revealed the presence of Bcc on the upper surface of rubber stopper of sealed multidose amikacin vials. Isolates from blood culture and rubber stoppers were confirmed as Bcc by recA PCR. EMLST revealed that these isolates shared an identical novel sequence type 824 proving clonality. Timely interventions instituted led to control of the outbreak. This study highlights the importance of identification and molecular characterization of Bcc to establish its role in infection and outbreak.

Pivotal ERIVANCE basal cell carcinoma (BCC) study: 12-month update of efficacy and safety of vismodegib in advanced BCC.

PubMed

Sekulic, Aleksandar; Migden, Michael R; Lewis, Karl; Hainsworth, John D; Solomon, James A; Yoo, Simon; Arron, Sarah T; Friedlander, Philip A; Marmur, Ellen; Rudin, Charles M; Chang, Anne Lynn S; Dirix, Luc; Hou, Jeannie; Yue, Huibin; Hauschild, Axel

2015-06-01

Primary analysis from the pivotal ERIVANCE BCC study resulted in approval of vismodegib, a Hedgehog pathway inhibitor indicated for treatment of adults with metastatic or locally advanced basal cell carcinoma (BCC) that has recurred after surgery or for patients who are not candidates for surgery or radiation. An efficacy and safety analysis was conducted 12 months after primary analysis. This was a multinational, multicenter, nonrandomized, 2-cohort study in patients with measurable and histologically confirmed locally advanced or metastatic BCC taking oral vismodegib (150 mg/d). Primary outcome measure was objective response rate (complete and partial responses) assessed by independent review facility. After 12 months of additional follow-up, median duration of exposure to vismodegib was 12.9 months. Objective response rate increased from 30.3% to 33.3% in patients with metastatic disease, and from 42.9% to 47.6% in patients with the locally advanced form. Median duration of response in patients with locally advanced BCC increased from 7.6 to 9.5 months. No new safety signals emerged with extended treatment duration. Limitations include low prevalence of advanced BCC and challenges of designing a study with heterogenous manifestations. The 12-month update of the study confirms the efficacy and safety of vismodegib in management of advanced BCC. Copyright © 2015 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

Body centered cubic magnesium niobium hydride with facile room temperature absorption and four weight percent reversible capacity.

PubMed

Tan, XueHai; Wang, Liya; Holt, Chris M B; Zahiri, Beniamin; Eikerling, Michael H; Mitlin, David

2012-08-21

We have synthesized a new metastable metal hydride with promising hydrogen storage properties. Body centered cubic (bcc) magnesium niobium hydride (Mg(0.75)Nb(0.25))H(2) possesses 4.5 wt% hydrogen gravimetric density, with 4 wt% being reversible. Volumetric hydrogen absorption measurements yield an enthalpy of hydride formation of -53 kJ mol(-1) H(2), which indicates a significant thermodynamic destabilization relative to the baseline -77 kJ mol(-1) H(2) for rutile MgH(2). The hydrogenation cycling kinetics are remarkable. At room temperature and 1 bar hydrogen it takes 30 minutes to absorb a 1.5 μm thick film at sorption cycle 1, and 1 minute at cycle 5. Reversible desorption is achieved in about 60 minutes at 175 °C. Using ab initio calculations we have examined the thermodynamic stability of metallic alloys with hexagonal close packed (hcp) versus bcc crystal structure. Moreover we have analyzed the formation energies of the alloy hydrides that are bcc, rutile or fluorite.

Premelting hcp to bcc Transition in Beryllium

NASA Astrophysics Data System (ADS)

Lu, Y.; Sun, T.; Zhang, Ping; Zhang, P.; Zhang, D.-B.; Wentzcovitch, R. M.

2017-04-01

Beryllium (Be) is an important material with wide applications ranging from aerospace components to x-ray equipment. Yet a precise understanding of its phase diagram remains elusive. We have investigated the phase stability of Be using a recently developed hybrid free energy computation method that accounts for anharmonic effects by invoking phonon quasiparticles. We find that the hcp → bcc transition occurs near the melting curve at 0

Antiswarming: Structure and dynamics of repulsive chemically active particles

NASA Astrophysics Data System (ADS)

Yan, Wen; Brady, John F.

2017-12-01

Chemically active Brownian particles with surface catalytic reactions may repel each other due to diffusiophoretic interactions in the reaction and product concentration fields. The system behavior can be described by a "chemical" coupling parameter Γc that compares the strength of diffusiophoretic repulsion to Brownian motion, and by a mapping to the classical electrostatic one component plasma (OCP) system. When confined to a constant-volume domain, body-centered cubic (bcc) crystals spontaneously form from random initial configurations when the repulsion is strong enough to overcome Brownian motion. Face-centered cubic (fcc) crystals may also be stable. The "melting point" of the "liquid-to-crystal transition" occurs at Γc≈140 for both bcc and fcc lattices.

Elastic strain relaxation in interfacial dislocation patterns: II. From long- and short-range interactions to local reactions

NASA Astrophysics Data System (ADS)

Vattré, A.

2017-08-01

The long- and short-range interactions as well as planar reactions between two infinitely periodic sets of crossing dislocations are investigated using anisotropic elasticity theory in face- (fcc) and body- (bcc) centered cubic materials. Two preliminary cases are proposed to examine the substantial changes in the elastic stress states and the corresponding strain energies due to a slight rearrangement in the internal dislocation geometries and characters. In general, significant differences and discrepancies resulting from the considered cubic crystal structure and the approximation of isotropic elasticity are exhibited. In a third scenario, special attention is paid to connecting specific internal dislocation structures from the previous cases with non-equilibrium configurations predicted by the quantized Frank-Bilby equation for the (111) fcc and (110) bcc twist grain boundaries. The present solutions lead to the formation of energetically favorable dislocation junctions with non-randomly strain-relaxed configurations of lower energy. In particular, the local dislocation interactions and reactions form equilibrium hexagonal-shaped patterns with planar three-fold dislocation nodes without producing spurious far-field stresses.Numerical application results are presented from a selection of cubic metals including aluminum, copper, tantalum, and niobium. In contrast to the fcc materials, asymmetric dislocation nodes occur in the anisotropic bcc cases, within which the minimum-energy paths for predicting the fully strain-relaxed dislocation patterns depend on the Zener anisotropic factor with respect to unity. The associated changes in the dislocation structures as well as the removal of the elastic strain energy upon relaxations are quantified and also discussed.

Case-crossover study of Burkholderia cepacia complex bloodstream infection associated with contaminated intravenous bromopride.

PubMed

Martins, Ianick Souto; Pellegrino, Flávia Lúcia Piffano Costa; Freitas, Andrea d'Avila; Santos, Marisa da Silva; Ferraiuoli, Giovanna Ianini d'Alemeida; Vasques, Márcia Regina Guimarães; Amorim, Efigenia Lourdes Teixeira; Oliveira, Sandra; Nouér, Simone Aranha; Cardoso, Fernando Luiz Lopes; Mascarenhas, Luiz Affonso; Magalhães, Ana Cristina Gouveia; Cleinman, Isabella Barbosa; Figueiredo, Agnes Marie Sá; Moreira, Beatriz Meurer

2010-05-01

To investigate an outbreak of healthcare-associated Burkholderia cepacia complex (BCC) primary bloodstream infections (BCC-BSI). Case-crossover study in a public hospital, a university hospital and a private hospital in Rio de Janeiro, Brazil, from March 2006 to May 2006. Twenty-five patients with BCC-BSI. After determining the date BCC-BSI symptoms started for each patient, 3 time intervals of data collection were defined, each one with a duration of 3 days: the case period, starting just before BCC-BSI symptoms onset; the control period, starting 6 days before BCC-BSI symptoms onset; and the washout period, comprising the 3 days between the case period and the control period. Exposures evaluated were intravascular solutions and invasive devices and procedures. Potential risk factors were identified by using the McNemar chi(2) adjusted test. Cultures of samples of potentially contaminated solutions were performed. BCC strain typing was performed by pulsed-field gel electrophoresis using SpeI. The statistical analysis revealed that the use of bromopride and dipyrone was associated with BCC-BSI. A total of 21 clinical isolates from 17 (68%) of the 25 patients and an isolate obtained from the bromopride vial were available for strain typing. Six pulsotypes were detected. A predominant pulsotype (A) accounted for 11 isolates obtained from 11 patients (65%) in the 3 study hospitals. Our investigation, using a case-crossover design, of an outbreak of BCC-BSI infections concluded it was polyclonal but likely caused by infusion of contaminated bromopride. The epidemiological finding was validated by microbiological analysis. After recall of contaminated bromopride vials by the manufacturer, the outbreak was controlled.

C-C4-01: Statin Use and Risk of Basal Cell Carcinoma

PubMed Central

Asgari, Maryam M; Tang, Jean; Epstein, Ervin; Chren, Mary-Margaret; Warton, Margaret; Quesenberry, Charles P; Go, Alan S; Friedman, Gary D

2010-01-01

Background: Limited data exist about the association between statin use and skin cancer risk. We examined the independent relation between statin use and basal cell carcinoma (BCC) risk. Methods: We identified all members of a large integrated healthcare delivery system diagnosed with a histologically proven BCC in 1997. Subsequent BCCs were identified through 2006 from health plan electronic pathology records. Longitudinal exposure to statins and other lipid lowering agents was determined from automated pharmacy records. We used extended Cox regression to examine the independent association between receipt of statin therapy (ever vs. never, cumulative duration) and risk of subsequent BCC. To minimize confounding by indication, we conducted sensitivity analyses in the subset of individuals considered eligible for lipid lowering therapy based on national guidelines. Results: Among 12,123 members diagnosed with BCC who had no prior statin exposure, 6,381 developed a subsequent BCC during follow-up. Neither ever use of statins (adjusted hazard ratio [aHR] 1.02, 95% CI: 0.92–1.12) or cumulative duration of statin (aHR 1.02 per year, 95% CI: 0.99–1.11) was associated with subsequent BCC after adjustment for age, sex, and healthcare utilization. Risk estimates did not change appreciably when the analysis was limited to the subset of individuals who met eligibility criteria for initiating statin therapy. There was also no significant association between use of non-statin anti-lipemics and subsequent BCC (aHR 1.10, 95% CI: 0.76–1.58). Conclusions: Among a large cohort of individuals with BCC, statin therapy was not significantly associated with risk of subsequent BCC.

Clinical outcome following lung transplantation in patients with cystic fibrosis colonised with Burkholderia cepacia complex: results from two French centres.

PubMed

Boussaud, V; Guillemain, R; Grenet, D; Coley, N; Souilamas, R; Bonnette, P; Stern, M

2008-08-01

Infection with Burkholderia cepacia complex (BCC) is a life threatening complication of cystic fibrosis (CF), often seen as a contraindication for lung transplantation. A long term retrospective study was conducted of all patients with CF undergoing lung transplants from January 1990 to October 2006 in two French centres allowing transplantation in patients colonised with BCC. 22 of the 247 lung transplant patients with CF were infected with BCC (B. cenocepacia genomovar III (n = 8), B. multivorans genomovar II (n = 11), B. vietnamiensis genomovar V (n = 2) and B. stabilis genomovar IV (n = 1)). BCC colonisation was not associated with any significant excess mortality (HR 1.5, 95% CI 0.7 to 3.2; p = 0.58). However, early mortality rates tended to be higher in the BCC group than in the non-BCC group (3 month survival: 85% vs 95%, respectively; log rank p = 0.05). Univariate analysis showed that the risk of death was significantly higher for the eight patients infected with B. cenocepacia than for the other 14 colonised patients (HR 3.2, 95% CI 1.1 to 5.9; p = 0.04). None of the other risk factors tested-primary graft failure, late extubation, septicaemia-had a significant effect. The 5 year cumulative incidence rate of bronchiolitis obliterans syndrome was not significantly higher in the BCC group than in the non-BCC group (38% vs 24%, respectively; p = 0.35). Our results suggest that BCC infection with a non-genomovar III organism may not be associated with excess mortality after lung transplantation in patients with CF and should not be seen as sufficient reason to exclude lung transplantation. However, colonisation with B. cenocepacia remains potentially detrimental.

Epidemiologic risk factors of basal cell carcinoma development and age at onset in a Southern European population from Greece.

PubMed

Dessinioti, Clio; Tzannis, Kimon; Sypsa, Vana; Nikolaou, Vasiliki; Kypreou, Katerina; Antoniou, Christina; Katsambas, Andreas; Stratigos, Alexander J

2011-08-01

Basal cell carcinoma (BCC) is the most common form of skin cancer with increasing incidence rates worldwide. To assess the association of BCC with epidemiologic risk factors in a Southern European population from Greece, we conducted a hospital-based case-control study of 199 patients with BCC and 200 controls. In the multivariate analysis, fair skin colour was associated with increased risk of BCC (OR: 4.9, 95% CI: 2.4-10.0). However, darker skin phototypes III/IV (patient's reported sun sensitivity/tanning ability) showed a higher BCC risk (OR: 3.9, 95% CI: 1.8-8.5). Persons with occupational UV exposure of 5 years or more had a 2.7-fold increased risk (95% CI:1.4-5.3). There was an increased risk of BCC related to the number of sunburns after the age of 20 years (OR: 3.2, 95% CI: 1.4-7.3) and solar lentigines (OR: 6.8, 95% CI: 3.6-12.8). Subgroup analysis showed that different risk factors are associated with early onset BCC including the presence of dysplastic nevi (OR: 6.4, 95% CI: 1.5-27.2), the number of weeks per year spent at the beach during childhood (OR: 8.9, 95% CI: 3.3-24.1) and the history of sunburns during childhood (OR:5.0, 95% CI: 1.3-19.1). Fair skin colour was significantly associated with BCC risk. The relation of sunburns during adulthood with BCC underlies the importance of sunburn prevention throughout life time. Early onset BCCs seem to have a different pathogenetic background and were associated with dysplastic nevi as well as intermittent sun exposure and sunburns during the early years of life. © 2011 John Wiley & Sons A/S.

Deposition and characterization of magnetron sputtered bcc tantalum

NASA Astrophysics Data System (ADS)

Patel, Anamika

The goal of this thesis was to provide scientific and technical research results for developing and characterizing tantalum (Ta) coatings on steel substrates deposited by DC magnetron sputtering. Deposition of tantalum on steel is of special interest for the protection it offers to surfaces, e.g. the surfaces of gun barrels against the erosive wear of hot propellant gases and the mechanical damage caused by the motion of launching projectiles. Electro-plated chromium is presently most commonly used for this purpose; however, it is considered to be carcinogenic in its hexavalent form. Tantalum is being investigated as non-toxic alternative to chromium and also because of its superior protective properties in these extreme environments. DC magnetron sputtering was chosen for this investigation of tantalum coatings on steel substrates because it is a versatile industrial proven process for deposition of metals. Sputter deposited Ta films can have two crystallographic structures: (1) body center cubic (bcc) phase, characterized by high toughness and high ductility and (2) a tetragonal beta phase characterized by brittleness and a tendency to fail under stress. It was found in this work that the bcc Ta coatings on steel can be obtained reliably by either of two methods: (1) depositing Ta on a submicron, stoichiometric TaN seed layer reactively sputtered on unheated steel and (2) depositing Ta directly on steel heated above a critical temperature. For argon sputtering gas this critical temperature was found to be 400°C at a pressure of 5 mtorr. With the heavier krypton gas, this critical temperature is reduced to 350°C. X-ray diffraction (XRD) was used to investigate the structure of tantalum and nitride films, and the composition of the nitride films was measured by nuclear reaction analyses (NRA), which were used to study in detail the enhancement of the bcc phase of Ta on steel. The scratch adhesion tests performed with a diamond hemispherical tip of radius 200 mum under increasing loads revealed high critical load values for failure (>15 N) for the bcc coatings versus the low load values (<9 N) for the beta coatings. The coating deposited on TaN interlayers on sputter-etched steel had better adhesion than those on steel surface without sputter etching. The results for this work have demonstrated that by controlling the various process parameters of do magnetron sputtering, high quality bcc Ta coatings of multi-micron thickness with excellent adhesion to steel can be made. An important contribution of this dissertation is in the enhancing an understanding of this process. The impact of this research will be in a number of fields where superior protective castings are needed. These include military applications, electronic components, chemical processing, and others.

Thermodynamics and Equations of State of Iron to 350 GPa and 6000 K

NASA Astrophysics Data System (ADS)

Dorogokupets, P. I.; Dymshits, A. M.; Litasov, K. D.; Sokolova, T. S.

2017-03-01

The equations of state for solid (with bcc, fcc, and hcp structures) and liquid phases of Fe were defined via simultaneous optimization of the heat capacity, bulk moduli, thermal expansion, and volume at room and higher temperatures. The calculated triple points at the phase diagram have the following parameters: bcc-fcc-hcp is located at 7.3 GPa and 820 K, bcc-fcc-liquid at 5.2 GPa and 1998 K, and fcc-hcp-liquid at 106.5 GPa and 3787 K. At conditions near the fcc-hcp-liquid triple point, the Clapeyron slope of the fcc-liquid curve is dT/dP = 12.8 K/GPa while the slope of the hcp-liquid curve is higher (dT/dP = 13.7 K/GPa). Therefore, the hcp-liquid curve overlaps the metastable fcc-liquid curve at pressures of about 160 GPa. At high-pressure conditions, the metastable bcc-hcp curve is located inside the fcc-Fe or liquid stability field. The density, adiabatic bulk modulus and P-wave velocity of liquid Fe calculated up to 328.9 GPa at adiabatic temperature conditions started from 5882 K (outer/inner core boundary) were compared to the PREM seismological model. We determined the density deficit of hcp-Fe at the inner core boundary (T = 5882 K and P = 328.9 GPa) to be 4.4%.

Thermodynamics and Equations of State of Iron to 350 GPa and 6000 K.

PubMed

Dorogokupets, P I; Dymshits, A M; Litasov, K D; Sokolova, T S

2017-03-06

The equations of state for solid (with bcc, fcc, and hcp structures) and liquid phases of Fe were defined via simultaneous optimization of the heat capacity, bulk moduli, thermal expansion, and volume at room and higher temperatures. The calculated triple points at the phase diagram have the following parameters: bcc-fcc-hcp is located at 7.3 GPa and 820 K, bcc-fcc-liquid at 5.2 GPa and 1998 K, and fcc-hcp-liquid at 106.5 GPa and 3787 K. At conditions near the fcc-hcp-liquid triple point, the Clapeyron slope of the fcc-liquid curve is dT/dP = 12.8 K/GPa while the slope of the hcp-liquid curve is higher (dT/dP = 13.7 K/GPa). Therefore, the hcp-liquid curve overlaps the metastable fcc-liquid curve at pressures of about 160 GPa. At high-pressure conditions, the metastable bcc-hcp curve is located inside the fcc-Fe or liquid stability field. The density, adiabatic bulk modulus and P-wave velocity of liquid Fe calculated up to 328.9 GPa at adiabatic temperature conditions started from 5882 K (outer/inner core boundary) were compared to the PREM seismological model. We determined the density deficit of hcp-Fe at the inner core boundary (T = 5882 K and P = 328.9 GPa) to be 4.4%.

On the shock response of cubic metals

NASA Astrophysics Data System (ADS)

Bourne, N. K.; Gray, G. T.; Millett, J. C. F.

2009-11-01

The response of four cubic metals to shock loading is reviewed in order to understand the effects of microstructure on continuum response. Experiments are described that link defect generation and storage mechanisms at the mesoscale to observations in the bulk. Four materials were reviewed; these were fcc nickel, the ordered fcc intermetallic Ni3Al, the bcc metal tantalum, and two alloys based on the intermetallic phase TiAl; Ti-46.5Al-2Cr-2Nb and Ti-48Al-2Cr-2Nb-1B. The experiments described are in two groups: first, equation of state and shear strength measurements using Manganin stress gauges and, second, postshock microstructural examinations and measurement of changes in mechanical properties. The behaviors described are linked through the description of time dependent plasticity mechanisms to the final states achieved. Recovered targets displayed dislocation microstructures illustrating processes active during the shock-loading process. Reloading of previously shock-prestrained samples illustrated shock strengthening for the fcc metals Ni and Ni3Al while showing no such effect for bcc Ta and for the intermetallic TiAl. This difference in effective shock hardening has been related, on the one hand, to the fact that bcc metals have fewer available slip systems that can operate than fcc crystals and to the observation that the lower symmetry materials (Ta and TiAl) both possess high Peierls stress and thus have higher resistances to defect motion in the lattice under shock-loading conditions. These behaviors, compared between these four materials, illustrate the role of defect generation, transport, storage, and interaction in determining the response of materials to shock prestraining.

Expression of drebrin, an actin binding protein, in basal cell carcinoma, trichoblastoma and trichoepithelioma.

PubMed

Mizutani, Yoko; Iwamoto, Ikuko; Kanoh, Hiroyuki; Seishima, Mariko; Nagata, Koh-ichi

2014-06-01

Drebrin, an F-actin binding protein, is known to play important roles in cell migration, synaptogenesis and neural plasticity. Although drebrin was long thought to be specific for neuronal cells, its expression has recently been reported in non-neuronal cells. As for skin-derived cells, drebrin was shown to be enriched at adhering junctions (AJs) in cultured primary keratinocytes and also be highly expressed in basal cell carcinoma (BCC) cells. Since BCC and two types of benign neoplasm, trichoblastoma and trichoepithelioma, are considered to derive from the same origin, follicular germinative cells, it is sometimes difficult to morphologically distinguish BCC from trichoblastoma and trichoepithelioma. In this study, we performed immunohistochemical staining of drebrin in BCC, trichoblastoma and trichoepithelioma, to examine whether drebrin could serve as a biomarker for BCC diagnosis. In western blotting, drebrin was detected highly and moderately in the lysates from a squamous cell carcinoma cell line, DJM-1, and normal human epidermis, respectively. In immunofluorescence analyses, drebrin was colocalized with markers of AJs and tight junctions in DJM-1 cells and detected at cell-cell junction areas of human normal epidermis tissue. We then examined the distribution patterns of drebrin in BCC, trichoblastoma and trichoepithelioma. In BCC tissues, intense and homogeneous drebrin expression was observed mainly at tumor cell-cell boundaries. In contrast, drebrin was stained only weakly and non-homogeneously in trichoblastoma and trichoepthelioma tissue samples. For differential diagnosis of BCC, drebrin may be a novel and useful marker.

Basal-Cell Carcinoma Incidence and Associated Risk Factors in US Women and Men

PubMed Central

Wu, Shaowei; Han, Jiali; Li, Wen-Qing; Li, Tricia; Qureshi, Abrar A.

2013-01-01

There is a paucity of data on basal-cell carcinoma (BCC) in the United States, since most national registries do not collect information on BCC. We evaluated BCC incidence trends and associated risk factors for BCC in 140,171 participants from a US female cohort, the Nurses' Health Study (1986–2006), and a US male cohort, the Health Professionals' Follow-up Study (1988–2006). Age-adjusted BCC incidence rates increased from 519 cases per 100,000 person-years to 1,019 cases per 100,000 person years for women and increased from 606 cases per 100,000 person-years to 1,488 cases per 100,000 person-years for men during the follow-up period. Cox proportional hazards analysis identified the following phenotypic risk factors for BCC in both cohorts: family history of melanoma, blond or red hair colors, higher number of extremity moles, higher susceptibility to sunburn as a child/adolescent, and higher lifetime number of severe/blistering sunburns. The multivariate-adjusted risk ratio for the highest quintile of cumulative midrange ultraviolet B flux exposure versus the lowest quintile was 3.18 (95% confidence interval: 2.70, 3.76) in women and 1.90 (95% confidence interval: 1.57, 2.29) in men. BCC incidence was generally higher in men than in women, and BCC risk was strongly associated with several phenotypic and exposure factors, including midrange ultraviolet B radiation, in our study populations. PMID:23828250

Circular RNA expression in basal cell carcinoma.

PubMed

Sand, Michael; Bechara, Falk G; Sand, Daniel; Gambichler, Thilo; Hahn, Stephan A; Bromba, Michael; Stockfleth, Eggert; Hessam, Schapoor

2016-05-01

Circular RNAs (circRNAs), are nonprotein coding RNAs consisting of a circular loop with multiple miRNA, binding sites called miRNA response elements (MREs), functioning as miRNA sponges. This study was performed to identify differentially expressed circRNAs and their MREs in basal cell carcinoma (BCC). Microarray circRNA expression profiles were acquired from BCC and control followed by qRT-PCR validation. Bioinformatical target prediction revealed multiple MREs. Sequence analysis was performed concerning MRE interaction potential with the BCC miRNome. We identified 23 upregulated and 48 downregulated circRNAs with 354 miRNA response elements capable of sequestering miRNA target sequences of the BCC miRNome. The present study describes a variety of circRNAs that are potentially involved in the molecular pathogenesis of BCC.

Limitations of BCC_CSM's ability to predict summer precipitation over East Asia and the Northwestern Pacific

NASA Astrophysics Data System (ADS)

Gong, Zhiqiang; Dogar, Muhammad Mubashar Ahmad; Qiao, Shaobo; Hu, Po; Feng, Guolin

2017-09-01

This study examines the ability of the Beijing Climate Center Climate System Model (BCC_CSM) to predict the meridional pattern of summer precipitation over East Asia-Northwest Pacific (EA-NWP) and its East Asia-Pacific (EAP) teleconnection. The differences of summer precipitation modes of the empirical orthogonal function and the bias of atmospheric circulations over EA-NWP are analyzed to determine the reason for the precipitation prediction errors. Results indicate that the BCC_CSM could not reproduce the positive-negative-positive meridional tripole pattern from south to north that differs markedly from that observed over the last 20 years. This failure can be attributed to the bias of the BCC_CSM hindcasts of the summer EAP teleconnection and the low predictability of 500 hPa at the mid-high latitude lobe of the EAP. Meanwhile, the BCC_CSM hindcasts' deficiencies of atmospheric responses to SST anomalies over the Indonesia maritime continent (IMC) resulted in opposite and geographically shifted geopotential anomalies at 500 hPa as well as wind and vorticity anomalies at 850 hPa, rendering the BCC_CSM unable to correctly reproduce the EAP teleconnection pattern. Understanding these two problems will help further improve BCC_CSM's summer precipitation forecasting ability over EA-NWP.

Atomic Scale Medium Range Order and Relaxation Dynamics in Metallic Glass

NASA Astrophysics Data System (ADS)

Zhang, Pei

We studied the atomic scale structure of bulk metallic glass (BMG) with the combination of fluctuation electron microscopy (FEM) and hybrid reverse Monte Carlo (HRMC) simulation. Medium range order (MRO), which occupies the length scale between short range order (SRO) and long-range order, plays an important role on the properties of metallic glass, but the characterization of MRO in experiment is difficult because conventional techniques are not sensitive to the structure at MRO scale. Compared with the X-ray and neutron which can measure SRO by two-body correlation functions, FEM is an effective way to detect MRO structure through three and four-body correlation functions, providing information about the size, distribution, and internal structure of MRO combing HRMC modeling. Thickness estimation is necessary in FEM experiment and HRMC calculation, so in Chapter 3, we measured the elastic and inelastic mean free paths of metallic glass alloys based on focused ion beam prepared thin samples with measured thickness gradients. We developed a model based on the Wentzel atomic model to predict the elastic mean free path for other amorphous materials. In Chapter 4, we studied the correlation of MRO and glass forming ability ZrCuAl alloy. Results from Variable resolution fluctuation microscopy show that in Zr50Cu35Al15 the crystal-like clusters shrink but become more ordered, while icosahedral-like clusters grow. Compared with Zr50Cu45Al5, Zr50Cu35Al15 with poorer glass forming ability exhibits more stable crystal-like structure under annealing, indicating that destabilizing crystal-like structures is important to achieve better glass forming ability in this alloy. In Chapter 5, we studied the crystallization and MRO structural in deformed and quenched Ni60Nb40 metallic glass. The deformed Ni60Nb40 contains fewer icosahedral-like Voronoi clusters and more crystal-like and bcc-like Voronoi clusters. The crystal-like and bcc-like medium range order clusters may be the structural origin for its lower crystallization temperature compared with quenched alloy. Dynamics heterogeneity is proposed to be the microscopic origin of the dynamic nature of glass transition. Some experimental evidence and simulation have indicated that different regions of materials indeed relax at fast or slow rate. However, the spatial distribution of relaxation time visualized from the experiment as the direct evidence of heterogeneous dynamics is still challenging. We proposed to measure the structural dynamics of supercooled metallic glasses with electron correlation microscopy (ECM) technique at the nanometer scale. ECM was developed as a way to measure structural relaxation times of liquids with nanometer-scale spatial resolution using the coherent electron scattering equivalent of photon correlation spectroscopy. In chapter 6, we studied the experimental requirements of ECM to obtain reliable results. For example, the trajectory length must be at least 40 times the relaxation time to obtain a well-converged g2( t), and the time per frame must be less than 0.1 time the relaxation time to obtain sufficient sampling. ECM experiment was firstly realized in scanning transmission electron microscopy (STEM) mode and applied to measure the structural relaxation time of Pd based metallic glass. In order to overcome the drift problem and capture the spatial information, we developed ECM experiment in dark field (DF) mode. In Chapter 7, through DF-ECM, we visualized the spatially heterogeneous dynamics by in-situ heating Pt57.5Cu14.7Ni 5.3P22.5 nanowire into supercooled liquid state, and quantify the size of the heterogeneity by four-point correlation function. The thickness effect and temporal evolution of the heterogeneous domain were also discussed. Additionally, a fast near-surface dynamics was discovered, providing an effective mechanism for surface crystallization of liquids by homogeneous nucleation.

Burkholderia cepacia complex in cystic fibrosis in a Brazilian reference center.

PubMed

Dentini, Priscila; Marson, Fernando Augusto Lima; Bonadia, Luciana Cardoso; Bertuzzo, Carmen Sílvia; Ribeiro, Antônio Fernando; Levy, Carlos Emílio; Ribeiro, José Dirceu

2017-12-01

The Burkholderia cepacia complex (BCC) can cause a severe decline in lung function in cystic fibrosis (CF). Our objective was to determine the BCC prevalence and to evaluate its clinical impact on CF. Clinical and laboratory variables were determined for CF patients with BCC (Group-A = 50 patients) and without BCC (Group-B = 134 patients). The microorganisms were identified by biochemical tests, the Vitek2 ® Compact test, recA-PCR and recA-nested-PCR with species-specific primers and DNA sequencing. The patients were evaluated by the Shwachman-Kulczycki score (SKCS), Bhalla score (BS), spirometry and body mass index (BMI). The BCC prevalence was 22.5%. The most common species were Burkholderia multivorans (30%), Burkholderia cepacia (24%), Burkholderia cenocepacia IIIA (10%), B. cenocepacia IIIB (2%) and Burkholderia vietnamiensis (2%). There was difference between the groups in nutritional status (p = 0.02) and general activity (p = 0.026). There was difference in total BS points (p = 0.04) and the following parameters: bronchiectasis severity (p = 0.007), peribronchial thickening (p = 0.013), bronchiectasis extent (p = 0.01) and general aspects of the affected bronchial zone (p = 0.02). The respiratory disorder classifications were as follows: obstructive-4.8% (Group-A) and 23.8% (Group-B); restrictive-9.5% (Group-A and Group-B); obstructive + restrictive-19% (Group-A) and 1.6% (Group-B); and obstructive + restrictive with a decreased forced expiratory flow-47.6% (Group-A) and 30.2% (Group-B) (p = 0.02). Nutritional status was a minor contributing factor to weight, height and BMI in the Group-A (p = 0.02). The BCC prevalence, particularly the prevalence of B. multivorans, was higher in this study. The SKCS, BS, spirometry and nutritional status results showed that BCC has a negative impact on clinical status. Phenotypic methods are useful for the identification of presumptive BCC. The Vitek2 ® Compact test showed accuracy in BCC identification. PCR, nested-PCR, and recA sequencing showed specificity in BCC species identification.

Premelting hcp to bcc Transition in Beryllium.

PubMed

Lu, Y; Sun, T; Zhang, Ping; Zhang, P; Zhang, D-B; Wentzcovitch, R M

2017-04-07

Beryllium (Be) is an important material with wide applications ranging from aerospace components to x-ray equipment. Yet a precise understanding of its phase diagram remains elusive. We have investigated the phase stability of Be using a recently developed hybrid free energy computation method that accounts for anharmonic effects by invoking phonon quasiparticles. We find that the hcp → bcc transition occurs near the melting curve at 0

Burkholderia cepacia complex infection in an Adult Cystic Fibrosis unit in Madrid.

PubMed

Correa-Ruiz, Ana; Girón, Rosa; Buendía, Buenaventura; Medina-Pascual, M José; Valenzuela, Claudia; López-Brea, Manuel; Sáez-Nieto, Juan Antonio

2013-12-01

Burkholderia cepacia complex have emerged as significant pathogens in cystic fibrosis (CF) patients due to the risk of cepacia syndrome and the innate multi-resistance of the microorganisms to antibiotics. The aim of this study was to describe the antimicrobial susceptibility profiles, the genotypes and subtypes of BCC, and the clinical evolution of CF patients with BCC. The lung function and Brasfield and Shwachman score were assessed in 12 patients. BCC were identified and susceptibility was studied by MicroScan (Siemens). Species and genospecies of BCC were confirmed by molecular methods in a Reference Centre (Majadahonda). BCC were identified in 12 of 70 patients (17.1%) over a ten year period. The mean age to colonization by BCC was 24.4 years (SD: 7.71). B. cenocepacia was isolated in 4 patients (33.3%), B. contaminans was isolated in 3 patients (25%), both B. vietnamiensis and B. stabilis were isolated in 2 patients (16.7%), and B. cepacia, B. multivorans and B. late were isolated in one patient (8.3%). Among the B. cenocepacia, subtype IIIa was identified in two strains, and subtype IIIb was identified in the other two strains. There was susceptibility to meropenem in 90% of BCC, 80% to cotrimoxazole, 60% to minocycline, 50% to ceftazidime, and 40% to levofloxacin. B. cenocepacia was the most prevalent species among the BCC isolated in CF adult patients, and subtypes IIIa and IIIb were identified in the 50% of the strains. Meropenem and cotrimoxazole showed the best activity. Copyright © 2012 Elsevier España, S.L. All rights reserved.

Single-Nucleotide Polymorphisms of the MSH2 and MLH1 Genes, Potential Molecular Markers for Susceptibility to the Development of Basal Cell Carcinoma in the Brazilian Population.

PubMed

da Silva Calixto, Poliane; Lopes, Otávio Sérgio; Dos Santos Maia, Mayara; Herrero, Sylvia Satomi Takeno; Longui, Carlos Alberto; Melo, Cynthia Germoglio Farias; de Carvalho Filho, Ivan Rodrigues; Soares, Leonardo Ferreira; de Medeiros, Arnaldo Correia; Delatorre, Plínio; Khayat, André Salim; Burbano, Rommel Rodriguez; Lima, Eleonidas Moura

2018-07-01

Basal cell carcinoma - BCC is considered a multifactorial neoplasm involving genetic, epigenetic and environmental factors. Where UVB radiation is considered the main physical agent involved in BCC carcinogenesis. The Brazil and state of Paraíba are exposed to high levels of UVB rays. The mismatch repair - MMR is important DNA repair mechanisms to maintain replication fidelity. Therefore, single nucleotide polymorphisms (SNPs) in genes encoding proteins involved in MMR may be potential molecular markers of susceptibility to BCC. The objective of this study was to evaluate and describe for the first time the SNPs rs560246973, rs2303425 and rs565410865 and risk of developing BCC. The present study analyzed 100 samples of paraffin-embedded tissue from patients with histopathological diagnosis of BCC and 100 control samples. The results were obtained by genotyping method, Dideoxy Unique Allele Specific - PCR (DSASP). The SNPs rs2303425 were not associated with Basal Cell Carcinoma. However, the SNPs rs560246973 and rs565410865 was shown to be associated with the development of BCC when compared to control samples (P < 0.0001). The SNPs rs565410865 was also statistical significance between the genotypes of and the age group (p = 0.0027) and tumor location (p = 0,0191). The result suggests that SNPs rs2303425 and rs565410865 are associated with susceptibility to the development of BCC in the Brazilian population and may be considered as potential molecular markers for BCC.

Burkholderia cepacia complex in cystic fibrosis in the post-epidemic period: multilocus sequence typing-based approach.

PubMed

Fila, Libor; Dřevínek, Pavel

2017-11-01

Cystic fibrosis (CF) patients in the Czech Republic suffered in the late 1990s from an epidemic with ST32 strain of Burkholderia cepacia complex (Bcc). Cohort segregation of Bcc and of ST32 positive patients was introduced in 1999 and 2002, respectively. We performed a study to evaluate the molecular epidemiology of Bcc infection after implementation of these infection control measures. Patients attending the Prague CF adult Centre from 2000 to 2015 were included in the present study. Demographic data and microbial statuses were collected from patient records. All Bcc isolates were analyzed using multilocus sequence typing (MLST). The prevalences of epidemic strain ST32 and of other Bcc strains were calculated. Ninety out of 227 CF patients were infected with Bcc during the study period. The prevalence of ST32 cases significantly decreased from 46.5% in 2000-2001 to 10.4% in 2014-2015 (P < 0.001) due to occurrence of only one new case in 2003, as well as to the death of 72% of ST32-infected patients. Conversely, there was a significant increase in prevalence of other Bcc strains, which rose from 0 to 14.9% (P = 0.015) and of transient infections. A micro-epidemic of infection with ST630 strain was observed in 2014 in lung transplant patients hospitalized in intensive care unit. The prevalence of epidemic strain ST32 decreased, whereas that of non-clonal strains of Bcc increased. Routine use of MLST allowed early detection of new and potentially epidemic strains.

Bellevue Community College Community Impact Report, Fall 2002.

ERIC Educational Resources Information Center

Bellevue Community Coll., WA.

This document presents data pertaining to the impact of Bellevue Community College (BCC), Washington, on the surrounding community. The study examines both short- and long-term impacts of BCC on the larger community. Short-term impacts include the revenue and expenditures for which BCC is responsible, which for 2001-02 totaled $86,431,309. During…

22 CFR 41.33 - Nonresident alien Canadian border crossing identification card (BCC).

Code of Federal Regulations, 2012 CFR

2012-04-01

... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Nonresident alien Canadian border crossing... Nonresident alien Canadian border crossing identification card (BCC). (a) Validity of Canadian BCC. A Canadian....122, or if the consular or immigration officer determines that the alien to whom any such document was...

22 CFR 41.33 - Nonresident alien Canadian border crossing identification card (BCC).

Code of Federal Regulations, 2011 CFR

2011-04-01

... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Nonresident alien Canadian border crossing... Nonresident alien Canadian border crossing identification card (BCC). (a) Validity of Canadian BCC. A Canadian....122, or if the consular or immigration officer determines that the alien to whom any such document was...

22 CFR 41.33 - Nonresident alien Canadian border crossing identification card (BCC).

Code of Federal Regulations, 2013 CFR

2013-04-01

... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Nonresident alien Canadian border crossing... Nonresident alien Canadian border crossing identification card (BCC). (a) Validity of Canadian BCC. A Canadian....122, or if the consular or immigration officer determines that the alien to whom any such document was...

22 CFR 41.33 - Nonresident alien Canadian border crossing identification card (BCC).

Code of Federal Regulations, 2014 CFR

2014-04-01

... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Nonresident alien Canadian border crossing... Nonresident alien Canadian border crossing identification card (BCC). (a) Validity of Canadian BCC. A Canadian....122, or if the consular or immigration officer determines that the alien to whom any such document was...

The Importance of Dispersal for Bacterial Community Composition and Functioning

PubMed Central

Lindström, Eva S.; Östman, Örjan

2011-01-01

We conducted a metacommunity experiment to investigate the role of dispersal for bacterial community composition (BCC) and function of freshwater bacteria. Bacteria were dispersed from a common source pool into three different lake communities in their natural lake water. The experiment was conducted in dialysis bags to enable a decoupling between a change in the local environment and dispersal. BCC was determined by terminal restriction fragment length polymorphism (tRFLP) of the 16S rRNA gene. We show that the greatest changes in BCC occurred between 10% and 43% of dispersal of standing stock per day. Functioning, measured as growth rate, was also affected by dispersal in all three communities but the qualitative pattern differed between communities, sometimes showing a hump-shaped relationship to dispersal and sometimes decreasing with increasing dispersal. In all waters, functioning was related to BCC. Our results show that dispersal does affect BCC and functioning but that high dispersal rates are needed. Further, the effect of dispersal on BCC and function seem to depend on the quality of the habitat to which bacteria disperse into. PMID:21998714

Protein expression of MMP-2 and MT1-MMP in actinic keratosis, squamous cell carcinoma of the skin, and basal cell carcinoma.

PubMed

de Oliveira Poswar, Fabiano; de Carvalho Fraga, Carlos Alberto; Gomes, Emisael Stênio Batista; Farias, Lucyana Conceição; Souza, Linton Wallis Figueiredo; Santos, Sérgio Henrique Souza; Gomez, Ricardo Santiago; de-Paula, Alfredo Maurício Batista; Guimarães, André Luiz Sena

2015-02-01

Squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) are 2 skin neoplasms with distinct potentials to invasion and metastasis. Actinic keratosis (AK) is a precursor lesion of SCC. Immunohistochemistry was performed to evaluate the expression of MMP-2 and MT1-MMP in samples of BCC (n = 29), SCC (n = 12), and AK (n = 13). The ratio of positive cells to total cells was used to quantify the staining. Statistical significance was considered under the level P < .05. We found a higher expression of MMP-2 in tumor stroma and parenchyma of SCC as compared to BCC. The expression of this protein was also similar between SCC and its precursor actinic keratosis, and it was higher in the stroma of high-risk BCC when compared to low-risk BCC. MT1-MMP, which is an activator of MMP-2, was similarly expressed in all groups. Our results suggest that MMP-2 expression may contribute to the distinct invasive patterns seen in SCC and BCC. © The Author(s) 2014.

No Evidence of Human Papilloma Virus Infection in Basal Cell Carcinoma

PubMed Central

Nahidi, Yalda; Meibodi, Naser Tayyebi; Meshkat, Zahra; Esmaili, Habibollah; Jahanfakhr, Samaneh

2015-01-01

Background: Basal cell carcinoma (BCC) is the most common skin cancer among whites, and several risk factors have been discussed in itsdevelopment and progress. Detection of human papilloma virus (HPV) deoxyribonucleic acid (DNA) BCCs in some studies suggests that the virus may play a role in the pathogenesis of this disease. Several molecular studies showed conflicting reports. Aims: The purpose of this study was to investigate the association between HPV and BCC using polymerase chain reaction (PCR). Materials and Methods: HPV DNA detection was done for 42 paraffin-embedded tissue specimens of BCC and 42 normal skin samples around the lesions by PCR using GP5+/GP6+ primers. Results: HPV DNA was not found in any of the 42 samples of BCC, and only one normal skin sample around the lesions was positive for HPV DNA by PCR. Conclusion: In this study, no statistically significant difference was seen between the presence of HPV DNA in BCC and normal skin around the lesion, and HPV is not likely to have an important role in pathogenesis of BCC. PMID:26288402

Contribution of Lattice Distortion to Solid Solution Strengthening in a Series of Refractory High Entropy Alloys

NASA Astrophysics Data System (ADS)

Chen, H.; Kauffmann, A.; Laube, S.; Choi, I.-C.; Schwaiger, R.; Huang, Y.; Lichtenberg, K.; Müller, F.; Gorr, B.; Christ, H.-J.; Heilmaier, M.

2018-03-01

We present an experimental approach for revealing the impact of lattice distortion on solid solution strengthening in a series of body-centered-cubic (bcc) Al-containing, refractory high entropy alloys (HEAs) from the Nb-Mo-Cr-Ti-Al system. By systematically varying the Nb and Cr content, a wide range of atomic size difference as a common measure for the lattice distortion was obtained. Single-phase, bcc solid solutions were achieved by arc melting and homogenization as well as verified by means of scanning electron microscopy and X-ray diffraction. The atomic radii of the alloying elements for determination of atomic size difference were recalculated on the basis of the mean atomic radii in and the chemical compositions of the solid solutions. Microhardness (μH) at room temperature correlates well with the deduced atomic size difference. Nevertheless, the mechanisms of microscopic slip lead to pronounced temperature dependence of mechanical strength. In order to account for this particular feature, we present a combined approach, using μH, nanoindentation, and compression tests. The athermal proportion to the yield stress of the investigated equimolar alloys is revealed. These parameters support the universality of this aforementioned correlation. Hence, the pertinence of lattice distortion for solid solution strengthening in bcc HEAs is proven.

Structure and optical properties of evaporated films of the Cr- and V-group metals

NASA Technical Reports Server (NTRS)

Nestell, J. E., Jr.; Christy, R. W.; Cohen, M. H.; Ruben, G. C.

1980-01-01

Thin films of Cr, Mo, and W rapidly evaporated in high vacuum (5 x 10 to the -7th torr) onto room-temperature substrates show anomalously low reflectance (compared to bulk samples). From electron and X-ray diffraction and electron microscopy, the normal bcc crystal structure is found, but with very fine grains. Columnar grains about 100 A in diameter were separated by a less dense grain-boundary network about 10-A wide. The measured optical conductivity agrees with an inhomogeneous-medium model that assumes the normal crystalline conductivity for the grain interiors, with model parameters that correlate to the observed columnar grain size. In contrast, V and Nb films rapidly evaporated onto room-temperature substrates have the reflectance of bulk crystalline material. On liquid-nitrogen temperature substrates, however, V and Nb have normal bcc crystal structure but with small flat-plate grains, and the same model, with appropriate parameters, accounts for the optical conductivity. The difference between these two groups apparently depends on residual gases segregated at the grain boundaries in the Cr-group films.

Pressure-induced magneto-structural transition in iron via a modified solid-state nudged elastic band method

NASA Astrophysics Data System (ADS)

Zarkevich, Nikolai A.; Johnson, Duane D.

2015-03-01

Materials under pressure may exhibit critical electronic and structural transitions that affect equation of states, as known for superconductors and the magneto-structural transformations of iron with both geophysical and planetary implications. While experiments often use constant-pressure (diamond-anvil cell, DAC) measurements, many theoretical results address a constant-volume transitions, which avoid issues with magnetic collapse but cannot be directly compared to experiment. We establish a modified solid-state nudge elastic band (MSS-NEB) method to handle magnetic systems that may exhibit moment (and volume) collapse during transformation. We apply it to the pressure-induced transformation in iron between the low-pressure body-centered cubic (bcc) and the high-pressure hexagonal close-packed (hcp) phases, find the bcc-hcp equilibrium coexistence pressure and a transitional pathway, and compare to shock and DAC experiments. We use methods developed with support by the U.S. Department of Energy (DE-FG02-03ER46026 and DE-AC02-07CH11358). Ames Laboratory is operated for the DOE by Iowa State University under contract DE-AC02-07CH11358.

Dislocation loop formation by swift heavy ion irradiation of metals.

PubMed

Khara, Galvin S; Murphy, Samuel T; Duffy, Dorothy M

2017-07-19

A coupled two-temperature, molecular dynamics methodology is used to simulate the structural evolution of bcc metals (Fe and W) and fcc metals (Cu and Ni) following irradiation by swift heavy ions. Electronic temperature dependent electronic specific heat capacities and electron-phonon coupling strengths are used to capture the full effects of the variation in the electronic density of states. Tungsten is found to be significantly more resistant to damage than iron, due both to the higher melting temperature and the higher thermal conductivity. Very interesting defect structures, quite different from defects formed in cascades, are found to be created by swift heavy ion irradiation in the bcc metals. Isolated vacancies form a halo around elongated interstitial dislocation loops that are oriented along the ion path. Such configurations are formed by rapid recrystallization of the molten cylindrical region that is created by the energetic ion. Vacancies are created at the recrystallization front, resulting in excess atoms at the core which form interstitial dislocation loops on completion of crystallization. These unique defect structures could, potentially, be used to create metal films with superior mechanical properties and interesting nanostructures.

Dislocation loop formation by swift heavy ion irradiation of metals

NASA Astrophysics Data System (ADS)

Khara, Galvin S.; Murphy, Samuel T.; Duffy, Dorothy M.

2017-07-01

A coupled two-temperature, molecular dynamics methodology is used to simulate the structural evolution of bcc metals (Fe and W) and fcc metals (Cu and Ni) following irradiation by swift heavy ions. Electronic temperature dependent electronic specific heat capacities and electron-phonon coupling strengths are used to capture the full effects of the variation in the electronic density of states. Tungsten is found to be significantly more resistant to damage than iron, due both to the higher melting temperature and the higher thermal conductivity. Very interesting defect structures, quite different from defects formed in cascades, are found to be created by swift heavy ion irradiation in the bcc metals. Isolated vacancies form a halo around elongated interstitial dislocation loops that are oriented along the ion path. Such configurations are formed by rapid recrystallization of the molten cylindrical region that is created by the energetic ion. Vacancies are created at the recrystallization front, resulting in excess atoms at the core which form interstitial dislocation loops on completion of crystallization. These unique defect structures could, potentially, be used to create metal films with superior mechanical properties and interesting nanostructures.

Seismic anisotropy in the Earth's innermost inner core: Testing structural models against mineral physics predictions

DOE PAGES

Romanowicz, Barbara; Cao, Aimin; Godwal, Budhiram; ...

2016-01-06

Using an updated data set of ballistic PKIKP travel time data at antipodal distances, we test different models of anisotropy in the Earth's innermost inner core (IMIC) and obtain significantly better fits for a fast axis aligned with Earth's rotation axis, rather than a quasi-equatorial direction, as proposed recently. Reviewing recent results on the single crystal structure and elasticity of iron at core conditions, we find that an hcp structure with the fast c axis parallel to Earth's rotation is more likely but a body-centered cubic structure with the [111] axis aligned in that direction results in very similar predictionsmore » for seismic anisotropy. These models are therefore not distinguishable based on current seismological data. In addition, to match the seismological observations, the inferred strength of anisotropy in the IMIC (6–7%) implies almost perfect alignment of iron crystals, an intriguing, albeit unlikely situation, especially in the presence of heterogeneity, which calls for further studies. Fast axis of anisotropy in the central part of the inner core aligned with Earth's axis of rotation Lastly, the structure of iron in the inner core is most likely hcp, not bcc Not currently possible to distinguish between hcp and bcc structures from seismic observations« less

Geographic Clusters of Basal Cell Carcinoma in a Northern California Health Plan Population.

PubMed

Ray, G Thomas; Kulldorff, Martin; Asgari, Maryam M

2016-11-01

Rates of skin cancer, including basal cell carcinoma (BCC), the most common cancer, have been increasing over the past 3 decades. A better understanding of geographic clustering of BCCs can help target screening and prevention efforts. Present a methodology to identify spatial clusters of BCC and identify such clusters in a northern California population. This retrospective study used a BCC registry to determine rates of BCC by census block group, and used spatial scan statistics to identify statistically significant geographic clusters of BCCs, adjusting for age, sex, and socioeconomic status. The study population consisted of white, non-Hispanic members of Kaiser Permanente Northern California during years 2011 and 2012. Statistically significant geographic clusters of BCC as determined by spatial scan statistics. Spatial analysis of 28 408 individuals who received a diagnosis of at least 1 BCC in 2011 or 2012 revealed distinct geographic areas with elevated BCC rates. Among the 14 counties studied, BCC incidence ranged from 661 to 1598 per 100 000 person-years. After adjustment for age, sex, and neighborhood socioeconomic status, a pattern of 5 discrete geographic clusters emerged, with a relative risk ranging from 1.12 (95% CI, 1.03-1.21; P = .006) for a cluster in eastern Sonoma and northern Napa Counties to 1.40 (95% CI, 1.15-1.71; P < .001) for a cluster in east Contra Costa and west San Joaquin Counties, compared with persons residing outside that cluster. In this study of a northern California population, we identified several geographic clusters with modestly elevated incidence of BCC. Knowledge of geographic clusters can help inform future research on the underlying etiology of the clustering including factors related to the environment, health care access, or other characteristics of the resident population, and can help target screening efforts to areas of highest yield.

Resonance Raman of BCC and normal skin

NASA Astrophysics Data System (ADS)

Liu, Cheng-hui; Sriramoju, Vidyasagar; Boydston-White, Susie; Wu, Binlin; Zhang, Chunyuan; Pei, Zhe; Sordillo, Laura; Beckman, Hugh; Alfano, Robert R.

2017-02-01

The Resonance Raman (RR) spectra of basal cell carcinoma (BCC) and normal human skin tissues were analyzed using 532nm laser excitation. RR spectral differences in vibrational fingerprints revealed skin normal and cancerous states tissues. The standard diagnosis criterion for BCC tissues are created by native RR biomarkers and its changes at peak intensity. The diagnostic algorithms for the classification of BCC and normal were generated based on SVM classifier and PCA statistical method. These statistical methods were used to analyze the RR spectral data collected from skin tissues, yielding a diagnostic sensitivity of 98.7% and specificity of 79% compared with pathological reports.

Basal cell carcinoma of the skin (part 1): epidemiology, pathology and genetic syndromes.

PubMed

Correia de Sá, Tiago Ribeiro; Silva, Roberto; Lopes, José Manuel

2015-11-01

Basal cell carcinoma (BCC) is the most common skin cancer worldwide with increasing incidence, but difficult to assess due to the current under registration practice. Despite the low mortality rate, BCC is a cause of great morbidity and an economic burden to health services. There are several risk factors that increase the risk of BCC and partly explain its incidence. Low-penetrance susceptibility alleles, as well as genetic alterations in signaling pathways, namely SHH pathway, also contribute to the carcinogenesis. BCC associate with several genetic syndromes, of which basal cell nevus syndrome is the most common.

Fe-Al alloy single-crystal thin film preparation for basic magnetic measurements

NASA Astrophysics Data System (ADS)

Abe, Tatsuya; Kawai, Tetsuroh; Futamoto, Masaaki; Ohtake, Mitsuru; Inaba, Nobuyuki

2018-04-01

Fe100-xAlx (x = 0, 4, 10, 20, 30 at. %) alloy films of 40 nm thickness are prepared on MgO(001) single-crystal substrates by varying substrate temperature from room temperature to 600 °C. Single-crystal films of (001) orientation with bcc-based disordered A2 structure are obtained for the Al content range of x = 0 - 20 at. %. An ordered phase of DO3 structure is observed in Fe70Al30 films prepared at temperatures higher than 200 °C, whereas (001) oriented single-crystal films of A2 structure are obtained when prepared at room temperature. The film surface profile does not depend much on the film composition, while the surface roughness increases with increasing substrate temperature. Island-like crystals are observed for films prepared at 600°C for all compositions. Difference in lattice spacing measured parallel and perpendicular to the substrate is noted for the single-crystal thin films and it increases with increasing Al content. The lattice strain in single-crystal film is caused possibly to accommodate the lattice mismatch with the MgO substrate. The (001)-oriented single-crystal films with A2 structure show four-fold symmetries in in-plane magnetic anisotropy with the easy magnetization axis A2[100] and the hard magnetization axis A2[110], whereas the films with DO3 ordered structure show almost isotropic magnetic properties.

Ab initio calculations of the elastic and thermodynamic properties of gold under pressure.

PubMed

Smirnov, N A

2017-03-15

The paper presents first-principles FP-LMTO calculations on the relative stability of fcc, bcc, hcp and dhcp gold under pressure. They were done in local density approximation (LDA), as well as in generalized gradient approximation (GGA) with and without spin-orbit interaction. Phonon spectra for the considered gold structures were obtained from LDA calculations within linear response theory and the contribution of lattice vibrations to the free energy of the system was determined in quasiharmonic approximation. Our thorough adjustment of FP-LMTO internal parameters (linearization and tail energies, the MT-sphere radius) helped us to obtain results that agree well with the available experimental phase relation Dubrovinsky et al (2007 Phys. Rev. Lett. 98 045503) between fcc and hcp structures of gold under pressure. The calculations suggest that gold compressed at room temperature successively undergoes the following structural changes: [Formula: see text]. The paper also presents the calculated elastic constants of fcc, bcc and hcp Au, the principal Hugoniot and the melting curve. Calculated results were used to construct the PT-diagram which describes the relative stability of the gold structures under study up to 500 GPa.

Fast evaluation of 69 basal cell carcinomas with ex vivo fluorescence confocal microscopy: criteria description, histopathological correlation, and interobserver agreement.

PubMed

Bennàssar, Antoni; Carrera, Cristina; Puig, Susana; Vilalta, Antoni; Malvehy, Josep

2013-07-01

Fluorescence confocal microscopy (FCM) represents a first step toward a rapid "bedside pathology" in the Mohs surgery setting and in other fields of general pathology. To describe and validate FCM criteria for the main basal cell carcinoma (BCC) subtypes and to demonstrate the overall agreement with classic pathologic analysis of hematoxylin-eosin-stained samples. DESIGN A total of 69 BCCs from 66 patients were prospectively imaged using ex vivo FCM. Confocal mosaics were evaluated in real time and compared with classic pathologic analysis. Department of Dermatology, Hospital Clínic of Barcelona, Barcelona, Spain, between November 2010 and July 2011. Patients with BCC attending the Mohs Surgery Unit. Presence or absence of BCC and histological subtype (superficial, nodular, and infiltrating) in the confocal mosaics. Eight criteria for BCC were described, evaluated, and validated. Although there were minor differences among BCC subtypes, the most BCC-defining criteria were peripheral palisading, clefting, nuclear pleomorphism, and presence of stroma. These criteria were validated with independent observers (κ values >0.7 [corrected] for most criteria). We herein propose, describe, and validate FCM criteria for BCC diagnosis. Fluorescence confocal microscopy is an attractive alternative to histopathologic analysis of frozen sections during Mohs surgery because large areas of freshly excised tissue can be assessed in real time without the need for tissue processing while minimizing labor and costs.

Cytokeratin 20 expression in basaloid follicular hamartoma and infundibulocystic basal cell carcinoma.

PubMed

Honarpisheh, Hedieh; Glusac, Earl J; Ko, Christine J

2014-12-01

Tumors with similar or identical histopathologic features have been termed basaloid follicular hamartoma (BFH) or infundibulocystic basal cell carcinoma (BCC). BCC typically lacks immunoreactivity with cytokeratin 20 (CK20) and pleckstrin homology-like domain, family A, member 1 protein (PHLDA1). A series of BFH and infundibulocystic BCC were investigated to determine the pattern of CK20 and PHLDA1 labeling in these lesions. Thirty-six samples of BFH (n = 14) and infundibulocystic BCC (n = 22) were collected. CK20 and PHLDA1 staining was performed and evaluated. All the lesions were small (average of 3 mm), well circumscribed, and composed of basaloid to squamoid cells arranged in islands resembling ramifying rootlets with interspersed horn cysts. CK20-positive cells were present in all 36 cases (average, 22/mm(2)), throughout the tumor, including deeper portions, irrespective of original diagnosis. Six of thirty cases (20%; 5 infundibulocystic BCC, 1 BFH) were focally PHLDA1 positive. Findings on hematoxylin and eosin staining and those of CK20 staining in BFH and infundibulocystic BCC were similar, and in most cases were indistinguishable. The CK20 labeling was similar to that of trichoepithelioma. The findings add a degree of support to the argument that BFH and infundibulocystic BCC represent the same lesion and, further, a benign one. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

[Human papilloma virus infection in basal cell carcinoma of the skin: a systematic review and meta-analysis study].

PubMed

Ramezani, Mazaher; Sadeghi, Masoud

Human papillomaviruses (HPVs) are a large and ubiquitous group of viruses that some of them have been suggested as a co-factor in the development of non-melanoma skin cancers. The aim of this meta-analysis study was to evaluate HPVs' prevalence in basal cell carcinoma (BCC) of the skin and the risk of them in the BCC patients compared with the healthy controls. Five databases were searched from January 1980 to February 2017. A random-effects meta-analysis was done with the event rate (ER) for the prevalence of HPVs and odds ratio (OR) for estimation of the incidence of HPVs. Out of 1087 studies, 45 studies were included in the review. The pooled analysis demonstrated that the incidence of γ-HPV was effective in the BCC patients compared with the healthy controls [OR = 1.97; 95% CI: 1.52-2.55; p < 0.00001], but not for α-HPV, β-HPV and epidermodysplasia verruciformis (EV)-HPV (p > 0.05). The pooled ER of incidence of β1-HPV in the BCC patients was z3.3% and for β2-HPV in BCC patients was 44.2%. In conclusion, this meta-analysis showed that probably the risk of γ-HPV was more on BCC patients and also the rate of γ-HPV was higher than α-, β- and EV-HPVs in the BCC patients.

DEVELOPMENT OF INTERATOMIC POTENTIALS IN TUNGSTEN-RHENIUM SYSTEMS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Setyawan, Wahyu; Nandipati, Giridhar; Kurtz, Richard J.

2016-09-01

Reference data are generated using the ab initio method to fit interatomic potentials for the W-Re system. The reference data include single phases of W and Re, strained structures, slabs, systems containing several concentrations of vacancies, systems containing various types of interstitial defects, melt structures, structures in the σ and χ phases, and structures containing several concentrations of solid solutions of Re in bcc W and W in hcp Re. Future work will start the fitting iterations.

Development of a Knowledge Base of Ti-Alloys From First-Principles and Thermodynamic Modeling

NASA Astrophysics Data System (ADS)

Marker, Cassie

An aging population with an active lifestyle requires the development of better load-bearing implants, which have high levels of biocompatibility and a low elastic modulus. Titanium alloys, in the body centered cubic phase, are great implant candidates, due to their mechanical properties and biocompatibility. The present work aims at investigating the thermodynamic and elastic properties of bcc Tialloys, using the integrated first-principles based on Density Functional Theory (DFT) and the CALculation of PHAse Diagrams (CALPHAD) method. The use of integrated first-principles calculations based on DFT and CALPHAD modeling has greatly reduced the need for trial and error metallurgy, which is ineffective and costly. The phase stability of Ti-alloys has been shown to greatly affect their elastic properties. Traditionally, CALPHAD modeling has been used to predict the equilibrium phase formation, but in the case of Ti-alloys, predicting the formation of two metastable phases o and alpha" is of great importance as these phases also drastically effect the elastic properties. To build a knowledge base of Ti-alloys, for biomedical load-bearing implants, the Ti-Mo-Nb-Sn-Ta-Zr system was studied because of the biocompatibility and the bcc stabilizing effects of some of the elements. With the focus on bcc Ti-rich alloys, a database of thermodynamic descriptions of each phase for the pure elements, binary and Ti-rich ternary alloys was developed in the present work. Previous thermodynamic descriptions for the pure elements were adopted from the widely used SGTE database for global compatibility. The previous binary and ternary models from the literature were evaluated for accuracy and new thermodynamic descriptions were developed when necessary. The models were evaluated using available experimental data, as well as the enthalpy of formation of the bcc phase obtained from first-principles calculations based on DFT. The thermodynamic descriptions were combined into a database ensuring that the sublattice models are compatible with each other. For subsystems, such as the Sn-Ta system, where no thermodynamic description had been evaluated and minimal experimental data was available, first-principles calculations based on DFT were used. The Sn-Ta system has two intermetallic phases, TaSn2 and Ta3Sn, with three solution phases: bcc, body centered tetragonal (bct) and diamond. First-principles calculations were completed on the intermetallic and solution phases. Special quasirandom structures (SQS) were used to obtain information about the solution phases across the entire composition range. The Debye-Gruneisen approach, as well as the quasiharmonic phonon method, were used to obtain the finite-temperature data. Results from the first-principles calculations and experiments were used to complete the thermodynamic description. The resulting phase diagram reproduced the first-principles calculations and experimental data accurately. In order to determine the effect of alloying on the elastic properties, first-principles calculations based on DFT were systematically done on the pure elements, five Ti-X binary systems and Ti-X-Y ternary systems (X ≠ Y = Mo, Nb, Sn, Ta Zr) in the bcc phase. The first-principles calculations predicted the single crystal elastic stiffness constants cij 's. Correspondingly, the polycrystalline aggregate properties were also estimated from the cij's, including bulk modulus B, shear modulus G and Young's modulus E. The calculated results showed good agreement with experimental results. The CALPHAD method was then adapted to assist in the database development of the elastic properties as a function of composition. On average, the database predicted the elastic properties of higher order Ti-alloys within 5 GPa of the experimental results. Finally, the formation of the metastable phases, o and alpha" was studied in the Ti-Ta and Ti-Nb systems. The formation energy of these phases, calculated from first-principles at 0 K, showed that the phases have similar formation energies to the bcc and hcp phases. Inelastic neutron scattering was completed on four different Ti-Nb compositions to study the entropy of the phases as well as the transformations occurring when the phases form and the phase fractions. Ongoing work is being done to use the experimental information to introduce thermodynamic descriptions for these two phases in the Ti-Nb system in order to be able to predict the formation and phase fractions. DFT based first-principles were used to predict the effect these phases have on the elastic properties and a rule of mixtures was used to determine the elastic properties of multi-phase alloys. The results were compared with experiments and showed that if the ongoing modeling can predict the phase fraction, the elastic database can accurately predict the elastic properties of the o and alpha" phases. This thesis provides a knowledge base of the thermodynamic and elastic properties of Ti-alloys from computational thermodynamics. The databases created will impact research activities on Ti-alloys and specifically efforts focused on Ti-alloys for biomedical applications.

Histopathological study of perilesional skin in patients diagnosed with nonmelanoma skin cancer.

PubMed

Apalla, Z; Calzavara-Pinton, P; Lallas, A; Argenziano, G; Kyrgidis, A; Crotti, S; Facchetti, F; Monari, P; Gualdi, G

2016-01-01

Epidemiological and clinical data suggest that actinic damage to the skin is an important predictor of skin carcinogenesis. To investigate the association of squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) with sun-damage alterations seen by histopathology. In the current prospective study, perilesional skin of SCC or BCC lesions was evaluated for presence of alterations associated with chronic photodamage. Presence of scarring, perineural/perivascular invasion, haemorrhage/haemorrhagic crust, ulceration/erosion and margin involvement were also assessed. Of 6038 included lesions, 4523 (74.9%) were BCCs and 1515 (25.1%) were SCCs. Presence of actinic damage was five times more frequent in SCC than in BCC (OR = 5.29, 95% CI 4.44-6.00, P < 0.001), and diagnosis of SCC was twice as common in photo-exposed than nonphoto-exposed body sites (OR = 2.34, 95% CI 2.03-2.70, P < 0.001). There were twofold higher odds for actinic damage in SCC compared with Bowen disease (OR = 2.015, 95% CI 1.55-2.61, P < 0.001). Assessing the different BCC histological subtypes, we found that nodular BCC had at least twofold higher odds (OR = 2.63, 95% CI 2.09-3.32), infiltrative BCC had 48% higher odds (OR = 1.487, 95% CI 1.18-1.87) and basosquamous BCC had fourfold higher odds (OR = 4.10, 95% CI 3.01-5.57) of having actinic damage compared with superficial BCC. Histological verification of ultraviolet-associated alterations in the perilesional skin in patients with NMSC in our study confirms the aetiopathogenic link between sun exposure and epithelial carcinogenesis on a histopathological basis. This correlation was stronger for SCCs than for BCCs. © 2015 British Association of Dermatologists.

Evaluation of the tropical variability from the Beijing Climate Center's real-time operational global Ocean Data Assimilation System

NASA Astrophysics Data System (ADS)

Zhou, Wei; Chen, Mengyan; Zhuang, Wei; Xu, Fanghua; Zheng, Fei; Wu, Tongwen; Wang, Xin

2016-02-01

The second-generation Global Ocean Data Assimilation System of the Beijing Climate Center (BCC GODAS2.0) has been run daily in a pre-operational mode. It spans the period 1990 to the present day. The goal of this paper is to introduce the main components and to evaluate BCC GODAS2.0 for the user community. BCC GODAS2.0 consists of an observational data preprocess, ocean data quality control system, a three-dimensional variational (3DVAR) data assimilation, and global ocean circulation model [Modular Ocean Model 4 (MOM4)]. MOM4 is driven by six-hourly fluxes from the National Centers for Environmental Prediction. Satellite altimetry data, SST, and in-situ temperature and salinity data are assimilated in real time. The monthly results from the BCC GODAS2.0 reanalysis are compared and assessed with observations for 1990-2011. The climatology of the mixed layer depth of BCC GODAS2.0 is generally in agreement with that ofWorld Ocean Atlas 2001. The modeled sea level variations in the tropical Pacific are consistent with observations from satellite altimetry on interannual to decadal time scales. Performances in predicting variations in the SST using BCC GODAS2.0 are evaluated. The standard deviation of the SST in BCC GODAS2.0 agrees well with observations in the tropical Pacific. BCC GODAS2.0 is able to capture the main features of El Ni˜no Modoki I and Modoki II, which have different impacts on rainfall in southern China. In addition, the relationships between the Indian Ocean and the two types of El Ni˜no Modoki are also reproduced.

History of Allergy and Atopic Dermatitis in Relation to Squamous Cell and Basal Cell Carcinoma of the Skin

PubMed Central

Cheng, Judy; Zens, M. Scot; Duell, Eric; Perry, Ann E.; Chapman, M. Shane; Karagas, Margaret R.

2015-01-01

Background Little is known about whether history of allergies and atopy are related to the occurrence of keratinocyte cancers. Thus, we evaluated the association between history of allergies and atopy and the incidence of squamous cell carcinoma (SCC) and early onset basal cell carcinoma (BCC). Methods As part of a population-based case-control study, interviews were conducted with 1,050 residents of New Hampshire (375 early onset BCC cases and 251 controls, 254 SCC cases and 432 controls). Odds ratios (ORs) of SCC and early onset BCC and history of allergy and atopic dermatitis were computed using logistic regression, while controlling for potential confounding factors. Results An overall inverse association was observed between a history of allergy and early onset BCC (OR 0.61, 95% CI 0.38-0.97) but not SCC (OR 1.18, 95% CI 0.78-1.79). Among women, we found reduced ORs of both early onset BCC and for SCC in relation to allergy history (early onset BCC OR 0.53, 95% CI 0.31-0.92 and SCC OR 0.59, 95% CI 0.29-1.19). Among men, we observed no clear association with early onset BCC (OR 0.87, 95% CI 0.39-1.99) and an increased risk of SCC (OR 1.58, 95% CI 0.93-2.69). Conclusion Our findings suggest that allergies and atopy may influence risk of early onset BCC and SCC, and that effects may be gender specific. Impact A deeper understanding of the immune mechanisms underlying allergies and atopy may provide new routes of preventing keratinocyte cancer. PMID:25670807

Patterns and timing of sunlight exposure and risk of basal cell and squamous cell carcinomas of the skin--a case-control study.

PubMed

Iannacone, Michelle R; Wang, Wei; Stockwell, Heather G; O'Rourke, Kathleen; Giuliano, Anna R; Sondak, Vernon K; Messina, Jane L; Roetzheim, Richard G; Cherpelis, Basil S; Fenske, Neil A; Rollison, Dana E

2012-09-20

Non-melanoma skin cancer (NMSC), comprised of basal (BCC) and squamous (SCC) cell carcinomas, is the most common cancer in Caucasians. Ultraviolet radiation (UVR) exposure is the most important environmental risk factor for NMSC. However, the precise relationship between UVR and the risk of NMSC is complex, and the relationship may differ by skin cancer type. A case-control study was conducted among Florida residents to investigate measures of patterns (intermittent vs. continuous) and timing (childhood vs. adulthood) of sunlight exposure in BCC and SCC. Participants included 218 BCC and 169 SCC cases recruited from a university dermatology clinic and 316 controls with no history of skin or other cancers. A history of blistering sunburn (a measure of intermittent sunlight exposure) was associated with both BCC (OR = 1.96, 95% CI = 1.27-3.03) and SCC (OR = 2.02, 95% CI = 1.22-3.33). Additionally, having a job in the sun for ≥ 3 months for 10 years or longer (a measure of continuous sunlight exposure) was also associated with both BCC and SCC in our study population. With the exception of younger age at first blistering sunburn, measures of younger age at sunlight exposure tended to be associated with SCC, but not BCC risk. Results from the current study suggest that sunlight exposure is associated with both BCC and SCC risk regardless of the pattern in which the exposure was received (i.e. intermittent vs. continuous). The data also suggest that sunlight exposure at a younger age may be more important for SCC but not BCC, however additional studies are needed to further characterize sunlight exposure-response relationships in different types of NMSC.

Patterns and timing of sunlight exposure and risk of basal cell and squamous cell carcinomas of the skin – a case–control study

PubMed Central

2012-01-01

Background Non-melanoma skin cancer (NMSC), comprised of basal (BCC) and squamous (SCC) cell carcinomas, is the most common cancer in Caucasians. Ultraviolet radiation (UVR) exposure is the most important environmental risk factor for NMSC. However, the precise relationship between UVR and the risk of NMSC is complex, and the relationship may differ by skin cancer type. Methods A case–control study was conducted among Florida residents to investigate measures of patterns (intermittent vs. continuous) and timing (childhood vs. adulthood) of sunlight exposure in BCC and SCC. Participants included 218 BCC and 169 SCC cases recruited from a university dermatology clinic and 316 controls with no history of skin or other cancers. Results A history of blistering sunburn (a measure of intermittent sunlight exposure) was associated with both BCC (OR = 1.96, 95% CI = 1.27-3.03) and SCC (OR = 2.02, 95% CI = 1.22-3.33). Additionally, having a job in the sun for ≥3 months for 10 years or longer (a measure of continuous sunlight exposure) was also associated with both BCC and SCC in our study population. With the exception of younger age at first blistering sunburn, measures of younger age at sunlight exposure tended to be associated with SCC, but not BCC risk. Conclusions Results from the current study suggest that sunlight exposure is associated with both BCC and SCC risk regardless of the pattern in which the exposure was received (i.e. intermittent vs. continuous). The data also suggest that sunlight exposure at a younger age may be more important for SCC but not BCC, however additional studies are needed to further characterize sunlight exposure-response relationships in different types of NMSC. PMID:22994655

Patterns of Ultraviolet Radiation Exposure and Skin Cancer Risk: the E3N-SunExp Study.

PubMed

Savoye, Isabelle; Olsen, Catherine M; Whiteman, David C; Bijon, Anne; Wald, Lucien; Dartois, Laureen; Clavel-Chapelon, Françoise; Boutron-Ruault, Marie-Christine; Kvaskoff, Marina

2018-01-05

While ultraviolet (UV) radiation exposure is a recognized risk factor for skin cancer, associations are complex and few studies have allowed a direct comparison of exposure profiles associated with cutaneous melanoma, basal-cell carcinoma (BCC), and squamous-cell carcinoma (SCC) within a single population. We examined associations between UV exposures and skin cancer risk in a nested case-control study within E3N, a prospective cohort of 98,995 French women born in 1925-1950. In 2008, a lifetime UV exposure questionnaire was sent to all reported skin cancer cases and three controls per case, which were matched on age, county of birth, and education. Analyses were performed using conditional logistic regression and included 366 melanoma cases, 1,027 BCC cases, 165 SCC cases, and 3,647 controls. A history of severe sunburns <25 years was associated with increased risks of all skin cancers (melanoma: OR 2.7; BCC: OR 1.7; SCC: OR 2.0 for ≥6 sunburns vs. none), while sunburns ≥25 years were associated with BCC and SCC only. While high-sun protection factor sunscreen use before age 25 was associated with lower BCC risk (P trend = 0.02), use since age 25 and reapplication of sunscreen were associated with higher risks of all three types of skin cancer. There were positive linear associations between total UV score and risks of BCC (P trend = 0.01) and SCC (P trend = 0.09), but not melanoma. While recreational UV score was strongly associated with BCC, total and residential UV scores were more strongly associated with SCC. Melanoma, BCC, and SCC are associated with different sun exposure profiles in women.

Use of non-steroidal anti-inflammatory drugs and risk of basal cell carcinoma in the United States Radiologic Technologists study

PubMed Central

EK, Cahoon; P, Rajaraman; BH, Alexander; MM, Doody; MS, Linet; DM, Freedman

2011-01-01

Non-steroidal anti-inflammatory drugs (NSAIDs) have been associated with reduced risk of colorectal and other cancers, but the association with basal cell carcinoma (BCC) is unclear. Previous epidemiological studies have been small in size, conducted in especially vulnerable populations, or have not accounted for solar UV exposure, a major risk factor for BCC. In the United States Radiologic Technologists cohort, we followed subjects to assess NSAID use on risk of first incident BCC. We included Caucasian participants who responded to both second and third questionnaires (administered from 1994–1998 and 2003–2005, respectively) and who reported no cancer at the time of the second questionnaire, N=58,213. BCC, constituent risk factors (e.g., eye color, complexion, hair color) and sun exposure history were assessed through self-administered survey. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazards models. Of the 58,213 people in the study population, 2,291 went on to develop BCC. Any NSAID use was not associated with subsequent incidence of BCC (HR = 1.04, 95% CI: 0.92–1.16) after adjusting for age, sex, and estimated lifetime summer sun exposure. No association was observed when stratified by NSAID type (aspirin and other NSAIDs), nor did dose-response patterns emerge by frequency of use (average days per month). Further analyses did not reveal interaction with sex, birth cohort, smoking, alcohol consumption, sun exposure, occupational radiation exposure, or personal risk factors for BCC. In this large nationwide study, we observed no association between NSAID use and subsequent BCC risk. PMID:21780102

Basal cell carcinoma-treatments for the commonest skin cancer.

PubMed

Berking, Carola; Hauschild, Axel; Kölbl, Oliver; Mast, Gerson; Gutzmer, Ralf

2014-05-30

With an incidence of 70 to over 800 new cases per 100 000 persons per year, basal cell carcinoma (BCC) is a very common disease, accounting for about 80% of all cases of non-melanoma skin cancer. It very rarely metastasizes. A variety of treatments are available for the different subtypes and stages of BCC. This review is based on pertinent literature retrieved by a selective search in the Medline database, as well as the American Cancer Society guidelines on BCC and the German guidelines on BCC and skin cancer prevention. The gold standard of treatment is surgical excision with histological control of excision margins, which has a 5-year recurrence rate of less than 3% on the face. For superficial BCC, approved medications such as imiquimod (total remission rate, 82-90%) and topical 5-fluorouracil (80%) are available, as is photodynamic therapy (71-87%). Other ablative methods (laser, cryosurgery) are applicable in some cases. Radiotherapy is an alternative treatment for invasive, inoperable BCC, with 5-year tumor control rates of 89-96%. Recently, drugs that inhibit an intracellular signaling pathway have become available for the treatment of locally advanced or metastatic BCC. Phase I and II clinical trials revealed that vismodegib was associated with objective response rates of 30-55% and tumor control rates of 80-90%. This drug was approved on the basis of a non-randomized trial with no control arm. It has side effects ranging from muscle cramps (71%) and hair loss (65%) to taste disturbances (55%) and birth defects. The established, standard treatments are generally highly effective. Vismodegib is a newly approved treatment option for locally advanced BCC that is not amenable to either surgery or radiotherapy.

Detailed Investigation of Core-Shell Precipitates in a Cu-Containing High Entropy Alloy

NASA Astrophysics Data System (ADS)

Alam, T.; Gwalani, B.; Viswanathan, G.; Fraser, H.; Banerjee, R.

2018-05-01

Due to the competing influences of configurational entropy and enthalpy of mixing, in recent years, secondary (including intermetallic) phases have been reported in many high entropy alloy (HEA) systems. These secondary phases offer great potential in terms of strengthening the HEA beyond the solid solution strengthening effects, and as such are of great interest in regards to alloy design for engineering applications. The present research investigates novel nano-scale core-shell precipitates forming within the disordered bcc matrix phase of an Al2CrCuFeNi2 HEA, utilizing complementary high-resolution microscopy techniques of atom probe tomography (APT) and transmission electron microscopy (TEM). The size, morphology, and local chemistry of these core-shell precipitates was measured by APT, and the composition was further corroborated by high-resolution scanning transmission electron microscopy-energy dispersive spectroscopy in an aberration-corrected TEM. Furthermore, high-resolution TEM imaging of the core-shell structure indicates that the Cu-rich core exhibits a bcc crystal structure.

Tunneling-Magnetoresistance Ratio Comparison of MgO-Based Perpendicular-Magnetic-Tunneling-Junction Spin Valve Between Top and Bottom Co2Fe6B2 Free Layer Structure.

PubMed

Lee, Du-Yeong; Lee, Seung-Eun; Shim, Tae-Hun; Park, Jea-Gun

2016-12-01

For the perpendicular-magnetic-tunneling-junction (p-MTJ) spin valve with a nanoscale-thick bottom Co2Fe6B2 free layer ex situ annealed at 400 °C, which has been used as a common p-MTJ structure, the Pt atoms of the Pt buffer layer diffused into the MgO tunneling barrier. This transformed the MgO tunneling barrier from a body-centered cubic (b.c.c) crystallized layer into a mixture of b.c.c, face-centered cubic, and amorphous layers and rapidly decreased the tunneling-magnetoresistance (TMR) ratio. The p-MTJ spin valve with a nanoscale-thick top Co2Fe6B2 free layer could prevent the Pt atoms diffusing into the MgO tunneling barrier during ex situ annealing at 400 °C because of non-necessity of a Pt buffer layer, demonstrating the TMR ratio of ~143 %.

Pigmented Paraaxillary Located "Complex" Basal Cell Carcinoma Imitating clinically irritated Melanocytic Lesion - Succesfull Surgical Approach in Bulgarian Patient.

PubMed

Voicu, Cristiana; Mihai, Mara; Lupu, Mihai; Patterson, James W; Koleva, Nely; Wollina, Uwe; Lotti, Torello; Lotti, Jacopo; França, Katlein; Batashki, Atanas; Gianfaldoni, Serena; Bakardzhiev, Ilko; Mangarov, Hristo; Tchernev, Georgi

2017-07-25

Basal cell carcinoma (BCC) is the most frequently encountered neoplasm worldwide. While nodular BCC is the most frequent clinical subtype, other forms of BCC, such as superficial, cystic, morpheiform, infiltrative, and pigmented may also be encountered. We present the case of a 67-year-old male with a relatively well-defined infiltrative, pigmented plaque with multiple colours and peripheral growth situated in the right axillary region. The histopathologic examination performed after complete surgical excision of the tumour revealed a complex pigmented BCC with macronodular, fibroepithelioma-like, cystic, focally infiltrative and basosquamous features. Uncommon locations of BCCs in sun-protected areas such as the axillary region require a higher degree of suspicion for diagnosis. The complex histology of the presented case, including subtypes with differing biologic attributes, emphasises the importance of histopathological examination in the diagnosis and therapeutic management of BCC.

Adenoid basal cell carcinoma: a rare facet of basal cell carcinoma

PubMed Central

Saxena, Kartikay; Manohar, Vidya; Bhakhar, Vikas; Bahl, Sumit

2016-01-01

Basal cell carcinoma (BCC) is a common, locally invasive epithelial malignancy of skin and its appendages. Every year, close to 10 million people get diagnosed with BCC worldwide. While the histology of this lesion is mostly predictable, some of the rare histological variants such as cystic, adenoid, morpheaform, infundibulocystic, pigmented and miscellaneous variants (clear-cell, signet ring cell, granular, giant cell, adamantanoid, schwannoid) are even rarer, accounting for <10% of all BCC's. Adenoid BCC (ADBCC) is a very rare histopathological variant with reported incidence of only approximately 1.3%. The clinical appearance of this lesion can be a pigmented or non-pigmented nodule or ulcer without predilection for any particular site. We share a case report of ADBCC, a rare histological variant of BCC that showed interesting features not only histologically but also by clinically mimicking a benign lesion. PMID:27095806

An Assessment of Future Educational and Occupational Plans for Brevard Community College Technical Program Students.

ERIC Educational Resources Information Center

Whitehead, Everett

This practicum studies the future educational and/or occupational plans of 223 technical program students enrolled in Brevard Community College (BCC) during the Fall 1973 term in order to suggest adjustments in college procedures to facilitate student transition to continued college or to their chosen professions. The characteristics of technical…

Crystal structure of Earth's inner core: A first-principles study

NASA Astrophysics Data System (ADS)

Moustafa, S. G.; Schultz, A. J.; Zurek, E.; Kofke, D. A.

2017-12-01

Since the detection of the Earth's solid inner core (IC) by Lehmann in 1936, its composition and crystal structure (which are essential to understand Earth's evolution) have been controversial. While seismological measurements (e.g. PREM) can give a robust estimation of the density, pressure, and elasticity of the IC, they cannot be directly used to determine its composition and/or crystal structure. Experimentally, reaching the extreme IC conditions ( 330 GPa and 6000 K) and getting reliable measurements is very challenging. First-principles calculations provide a viable alternative that can work as a powerful investigative tool. Although several attempts have been made to assess phase stability at IC conditions computationally, they often use a low level of theory for electronic structure (e.g., classical force-field), adopt approximate methods (e.g., quasiharmonic approximation, fixed hcp-c/a), or do not consider finite-size effects. The study of phase stability using accurate first-principles methods is hampered in part by the difficulty of computing the free energy (FE), the central thermodynamic quantity that determines stability, while including anharmonic and finite-size effects. Additional difficulty related to the IC in particular is introduced by the dynamical instability of one of the IC candidate structures (bcc) at low temperature. Recently [1-3], we introduced a novel method (denoted as "harmonically mapped averaging", or HMA) to efficiently measure anharmonic properties (e.g. FE, pressure, elastic modulus) by molecular simulation, yielding orders of magnitude CPU speedup compared to conventional methods. We have applied this method to the hcp candidate phase of iron at the IC conditions, obtaining first-principles anharmonic FE values with unprecedented accuracy and precision [4]. We have now completed and report HMA calculations to assess the phase stability of all IC candidate phases (fcc/hcp/bcc). This knowledge is the prerequisite for interpreting the geophysical and geochemical constraints of the IC (e.g. anisotropy and low rigidity); which should be a key ingredient in the longstanding debate about the nature of the Earth's IC. References[1] 10.1103/PhysRevE.92.043303[2] 10.1021/acs.jctc.6b00018[3] 10.1021/acs.jctc.6b01082[4] 10.1103/PhysRevB.96.014117

BCC skin cancer diagnosis based on texture analysis techniques

NASA Astrophysics Data System (ADS)

Chuang, Shao-Hui; Sun, Xiaoyan; Chang, Wen-Yu; Chen, Gwo-Shing; Huang, Adam; Li, Jiang; McKenzie, Frederic D.

2011-03-01

In this paper, we present a texture analysis based method for diagnosing the Basal Cell Carcinoma (BCC) skin cancer using optical images taken from the suspicious skin regions. We first extracted the Run Length Matrix and Haralick texture features from the images and used a feature selection algorithm to identify the most effective feature set for the diagnosis. We then utilized a Multi-Layer Perceptron (MLP) classifier to classify the images to BCC or normal cases. Experiments showed that detecting BCC cancer based on optical images is feasible. The best sensitivity and specificity we achieved on our data set were 94% and 95%, respectively.

Energy barrier of bcc-fcc phase transition via the Bain path in Yukawa system

NASA Astrophysics Data System (ADS)

Kiyokawa, Shuji

2018-05-01

In the Yukawa system with the dimensionless screening parameter κ>1.5 , when bcc-fcc transition occurs via Bain path, we show that spontaneous transitions do not occur even if the system temperature reaches the transition point of bcc-fcc because it is necessary to increase once the free energy in the process of transition from bcc to fcc through Bain deformation. Here, we refer the temporary increment of the free energy during Bain deformation as Bain barrier. Since there are the Bain barriers at the transitions between bcc and fcc phases, these phases may coexist as metastable state in the wide region (not a coexistence line) of κ and the coupling constant Γ. We study the excess energy of the system and the free energy difference between bcc and fcc phases by the Monte Carlo method, where the simulation box is divided into a large number of elements with small volume and a particle in the box is restricted be placed in one of these elements. By this method, we can tabulate the values of the interparticle potential and can calculate the internal energy fast and precisely.

The detection of basal cell determinants in human basal cell carcinomas using two different monoclonal antibodies.

PubMed

Habets, J M; Tank, B; Vuzevski, V D; van Reede, E C; Stolz, E; van Joost, T

1987-01-01

This report deals with the reaction pattern(s) of two monoclonal antibodies (MoAbs) with normal skin and basal cell carcinomas (BCC). Using indirect immunoperoxidase (IIP) and indirect immunofluorescence (IIF) techniques, MoAb 12 G7 was observed to react with a determinant related to the cell membrane of the epidermal basal cells. In the IIP technique MoAb 12 G7 showed a positive reaction with 32 out of 34 BCC (94%), while in IIF all the 14 BCC that were studied were positive. In most cases only the cells at the periphery of the tumour nests were stained. MoAb 253 B7 reacted with cytoplasmic determinant(s) of the epidermal basal cells both in the IIF as well as in the IIP techniques. Using the IIP technique only 5 out of 34 BCC (15%) showed a positive reaction with this MoAb. Four of the 5 positively staining tumours showed aggressive histological features. Using IIF technique only 2 out of 14 BCC were positive. The results presented in this communication are discussed with regard to the possible expression of selective differentiation and tumor-associated determinant(s) in BCC.

Phase-Transformation Ductilization of Brittle High-Entropy Alloys via Metastability Engineering

DOE PAGES

Huang, Hailong; Wu, Yuan; He, Junyang; ...

2017-06-07

High-entropy alloys (HEAs) in which interesting physical, chemical, and structural properties are being continuously revealed have recently attracted extensive attention. Body-centered cubic (bcc) HEAs, particularly those based on refractory elements are promising for high-temperature application but generally fail by early cracking with limited plasticity at room temperature, which limits their malleability and widespread uses. In this paper, the “metastability-engineering” strategy is exploited in brittle bcc HEAs via tailoring the stability of the constituent phases, and transformation-induced ductility and work-hardening capability are successfully achieved. Finally, this not only sheds new insights on the development of HEAs with excellent combination of strengthmore » and ductility, but also has great implications on overcoming the long-standing strength–ductility tradeoff of metallic materials in general.« less

Phase-Transformation Ductilization of Brittle High-Entropy Alloys via Metastability Engineering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Hailong; Wu, Yuan; He, Junyang

High-entropy alloys (HEAs) in which interesting physical, chemical, and structural properties are being continuously revealed have recently attracted extensive attention. Body-centered cubic (bcc) HEAs, particularly those based on refractory elements are promising for high-temperature application but generally fail by early cracking with limited plasticity at room temperature, which limits their malleability and widespread uses. In this paper, the “metastability-engineering” strategy is exploited in brittle bcc HEAs via tailoring the stability of the constituent phases, and transformation-induced ductility and work-hardening capability are successfully achieved. Finally, this not only sheds new insights on the development of HEAs with excellent combination of strengthmore » and ductility, but also has great implications on overcoming the long-standing strength–ductility tradeoff of metallic materials in general.« less

Gradient Plasticity Model and its Implementation into MARMOT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barker, Erin I.; Li, Dongsheng; Zbib, Hussein M.

2013-08-01

The influence of strain gradient on deformation behavior of nuclear structural materials, such as boby centered cubic (bcc) iron alloys has been investigated. We have developed and implemented a dislocation based strain gradient crystal plasticity material model. A mesoscale crystal plasticity model for inelastic deformation of metallic material, bcc steel, has been developed and implemented numerically. Continuum Dislocation Dynamics (CDD) with a novel constitutive law based on dislocation density evolution mechanisms was developed to investigate the deformation behaviors of single crystals, as well as polycrystalline materials by coupling CDD and crystal plasticity (CP). The dislocation density evolution law in thismore » model is mechanism-based, with parameters measured from experiments or simulated with lower-length scale models, not an empirical law with parameters back-fitted from the flow curves.« less

In situ TEM observation of heterogeneous phase transition of a constrained single-crystalline Ag2Te nanowire.

PubMed

In, Juneho; Yoo, Youngdong; Kim, Jin-Gyu; Seo, Kwanyong; Kim, Hyunju; Ihee, Hyotchel; Oh, Sang Ho; Kim, Bongsoo

2010-11-10

Laterally epitaxial single crystalline Ag2Te nanowires (NWs) are synthesized on sapphire substrates by the vapor transport method. We observed the phase transitions of these Ag2Te NWs via in situ transmission electron microscopy (TEM) after covering them with Pt layers. The constrained NW shows phase transition from monoclinic to a body-centered cubic (bcc) structure near the interfaces, which is ascribed to the thermal stress caused by differences in the thermal expansion coefficients. Furthermore, we observed the nucleation and growth of bcc phase penetrating into the face-centered cubic matrix at 200 °C by high-resolution TEM in real time. Our results would provide valuable insight into how compressive stresses imposed by overlayers affect behaviors of nanodevices.

Mineralogical modeling of the anisotropic inner core based on the phase relations and elasticity of iron and iron alloys under the Earth's core condition

NASA Astrophysics Data System (ADS)

Kuwayama, Y.; Tsuchiya, T.; Ohishi, Y.

2011-12-01

The inner-core and the outer-core, which make up the center of the Earth, are thought to be composed predominantly of a solid and liquid iron alloying with 5 to 15 % nickel, respectively. Determination of the physical properties of iron alloy at extremely high pressures found in the deep Earth's core (>300 GPa) is a fundamental issue for understanding the thermal and dynamical state of the Earth's core. According to seismological observations, it is widely accepted that the Earth's inner-core is elastically anisotropic; the compressional wave in the inner-core propagates 3~4 % faster along its rotational axis than in the equatorial direction. A number of models on core dynamics have been proposed to explain the origin of the inner-core anisotropy, but all of them are based on the idea of the crystal preferred orientation of iron. The phase relation of iron at high pressures has been extensively studied using LH-DACs. At relatively low temperatures, around room temperature, the phase relations are already well established; a low pressure phase with a bcc structure transforms into an hcp structure above ~10 GPa and it persists above 300 GPa. In contrast, the phase relations of iron at high temperatures are highly controversial. Some experiments assigned different crystal structures including orthorhombic, dhcp, fcc, and bcc as candidate stable crystal structures, whereas others suggested that the hcp structure remains stable at high temperatures. Despite considerable attention on these new phases, there is, however, no experimental reproducibility. The lack of plausible data is mainly because of the substantial difficulties associated with high-temperature experiments at multimegabar pressures. In order to overcome these difficulties, we have developed experimental techniques using a laser-heated diamond-anvil cell for the past decade and succeeded in obtaining excellent quality data under extremely high-pressure and high-temperature conditions. In order to investigate the nature of the Earth's inner core, we conducted a series of high P-T experiments on various iron-rich iron-alloys using laser-heated diamond anvil cells on the basis of in-situ x-ray diffraction measurements at SPring-8, Japan, along with ab-initio density functional simulations, under the Earth's core condition. Here we will present a mineralogical model of the observed anisotropy in the inner core based on the experimental and theoretical studies on the phase relations and physical properties of iron-alloys.

Atomistic simulation of cubic and tetragonal phases of U-Mo alloy: Structure and thermodynamic properties

NASA Astrophysics Data System (ADS)

Starikov, S. V.; Kolotova, L. N.; Kuksin, A. Yu.; Smirnova, D. E.; Tseplyaev, V. I.

2018-02-01

We studied structure and thermodynamic properties of cubic and tetragonal phases of pure uranium and U-Mo alloys using atomistic simulations: molecular dynamics and density functional theory. The main attention was paid to the metastable γ0 -phase that is formed in U-Mo alloys at low temperature. Structure of γ0 -phase is similar to body-centered tetragonal (bct) lattice with displacement of a central atom in the basic cell along [ 001 ] direction. Such displacements have opposite orientations for part of the neighbouring basic cells. In this case, such ordering of the displacements can be designated as antiferro-displacement. Formation of such complex structure may be interpreted through forming of short U-U bonds. At heating, the tetragonal structure transforms into cubic γs -phase, still showing ordering of central atom displacements. With rise in temperature, γs -phase transforms to γ-phase with a quasi body-centered cubic (q-bcc) lattice. The local positions of uranium atoms in γ-phase correspond to γs -phase, however, orientations of the central atom displacements become disordered. Transition from γ0 to γ can be considered as antiferro-to paraelastic transition of order-disorder type. This approach to the structure description of uranium alloy allows to explain a number of unusual features found in the experiments: anisotropy of lattice at low temperature; remarkably high self-diffusion mobility in γ-phase; decreasing of electrical resistivity at heating for some alloys. In addition, important part of this work is the development of new interatomic potential for U-Mo system made with taking into account details of studied structures.

Nutrition behaviour change communication causes sustained effects on IYCN knowledge in two cluster-randomised trials in Bangladesh.

PubMed

Hoddinott, John; Ahmed, Akhter; Karachiwalla, Naureen I; Roy, Shalini

2018-01-01

Behaviour change communication (BCC) can improve infant and young child nutrition (IYCN) knowledge, practices, and health outcomes. However, few studies have examined whether the improved knowledge persists after BCC activities end. This paper assesses the effect of nutrition sensitive social protection interventions on IYCN knowledge in rural Bangladesh, both during and after intervention activities. We use data from two, 2-year, cluster randomised control trials that included nutrition BCC in some treatment arms. These data were collected at intervention baseline, midline, and endline, and 6-10 months after the intervention ended. We analyse data on IYCN knowledge from the same 2,341 women over these 4 survey rounds. We construct a number correct score on 18 IYCN knowledge questions and assess whether the impact of the BCC changes over time for the different treatment groups. Effects are estimated using ordinary least squares accounting for the clustered design of the study. There are 3 main findings: First, the BCC improves IYCN knowledge substantially in the 1st year of the intervention; participants correctly answer 3.0-3.2 more questions (36% more) compared to the non-BCC groups. Second, the increase in knowledge between the 1st and 2nd year was smaller, an additional 0.7-0.9 correct answers. Third, knowledge persists; there are no significant decreases in IYCN knowledge 6-10 months after nutrition BCC activities ended. © 2017 The Authors. Maternal and Child Nutrition Published by John Wiley & Sons, Ltd.

Case-control study of smoking and non-melanoma skin cancer.

PubMed

Rollison, Dana E; Iannacone, Michelle R; Messina, Jane L; Glass, L Frank; Giuliano, Anna R; Roetzheim, Richard G; Cherpelis, Basil S; Fenske, Neil A; Jonathan, Kristen A; Sondak, Vernon K

2012-02-01

To investigate the association between cigarette smoking and basal and squamous cell carcinomas (BCC and SCC) of the skin, a clinic-based case-control study was conducted in Tampa, FL. Patients with histologically confirmed BCC/SCC were recruited from a university dermatology clinic (n = 215 BCC, 165 SCC). Controls were comprised of individuals with no history of skin cancer who screened negative for skin cancer upon physical examination at the affiliated cancer screening or primary care clinics (n = 315). Information on smoking and other risk factors was obtained from self-administered questionnaires. After adjustment for age, sex, and other skin cancer-risk factors, ever smoking was not associated with BCC (odds ratio (OR) = 1.26, 95% confidence interval (CI) = 0.83-1.92), but was statistically significantly associated with SCC (OR = 1.97, 95% CI = 1.19-3.26), with significant trends observed for SCC associated with increasing cigarettes per day (p = 0.01) and pack-years smoked (p = 0.01). Among men, smoking ≥20 pack-years was associated with non-significant increased risks of BCC (OR = 1.90, 95% CI = 0.88-4.12) and SCC (OR = 1.97, 95% CI = 0.84-4.66), whereas among women, no association was observed with BCC (OR = 0.98, 95% CI = 0.39-2.46) while a statistically significant three-fold risk was observed with SCC (OR = 3.00, 95% CI = 1.02-8.80). Cigarette smoking is more strongly associated with SCC than BCC, particularly among women.

Intrinsic Resistance of Burkholderia cepacia Complex to Benzalkonium Chloride

PubMed Central

Ahn, Youngbeom; Kim, Jeong Myeong; Kweon, Ohgew; Kim, Seong-Jae; Jones, Richard C.; Woodling, Kellie; Gamboa da Costa, Gonçalo; LiPuma, John J.; Hussong, David; Marasa, Bernard S.

2016-01-01

ABSTRACT Pharmaceutical products that are contaminated with Burkholderia cepacia complex (BCC) bacteria may pose serious consequences to vulnerable patients. Benzyldimethylalkylammonium chloride (BZK) cationic surfactants are extensively used in medical applications and have been implicated in the coselection of antimicrobial resistance. The ability of BCC to degrade BZK, tetradecyldimethylbenzylammonium chloride (C14BDMA-Cl), dodecyldimethylbenzylammonium chloride (C12BDMA-Cl), decyldimethylbenzylammonium chloride (C10BDMA-Cl), hexyldimethylbenzylammonium chloride, and benzyltrimethylammonium chloride was determined by incubation in 1/10-diluted tryptic soy broth (TSB) to determine if BCC bacteria have the ability to survive and inactivate these disinfectants. With BZK, C14BDMA-Cl, and C12BDMA-Cl, inhibition of the growth of 20 BCC strains was observed in disinfectant solutions that ranged from 64 to 256 µg/ml. The efflux pump inhibitor carbonyl cyanide m-chlorophenylhydrazone increased the sensitivity of bacteria to 64 µg/ml BZK. The 20 BCC strains grew well in 1/10-diluted TSB medium with BZK, C12BDMA-Cl, and C10BDMA-Cl; they absorbed and degraded the compounds in 7 days. Formation of benzyldimethylamine and benzylmethylamine as the initial metabolites suggested that the cleavage of the C alkyl-N bond occurred as the first step of BZK degradation by BCC bacteria. Proteomic data confirmed the observed efflux activity and metabolic inactivation via biodegradation in terms of BZK resistance of BCC bacteria, which suggests that the two main resistance mechanisms are intrinsic and widespread. PMID:27879334

Tailoring magnetic behavior of CoFeMnNiX (X = Al, Cr, Ga, and Sn) high entropy alloys by metal doping

DOE PAGES

Zuo, Tingting; Gao, Michael C.; Ouyang, Lizhi; ...

2017-03-07

Magnetic materials with excellent performances are desired for functional applications. Based on the high-entropy effect, a system of CoFeMnNiX (X = Al, Cr, Ga, and Sn) magnetic alloys are designed and investigated. The dramatic change in phase structures from face-centered-cubic (FCC) to ordered body-centered-cubic (BCC) phases, caused by adding Al, Ga, and Sn in CoFeMnNiX alloys, originates from the potent short-range chemical order in the liquid state predicted by ab initio molecular dynamics (AIMD) simulations. This phase transition leads to the significant enhancement of the saturation magnetization (M s), e.g., the CoFeMnNiAl alloy has M s of 147.86 Am 2/kg.more » In conclusion, first-principles density functional theory (DFT) calculations on the electronic and magnetic structures reveal that the anti-ferromagnetism of Mn atoms in CoFeMnNi is suppressed especially in the CoFeMnNiAl HEA because Al changes the Fermi level and itinerant electron-spin coupling that lead to ferromagnetism.« less

Arecoline decreases interleukin-6 production and induces apoptosis and cell cycle arrest in human basal cell carcinoma cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Li-Wen; Hsieh, Bau-Shan; Cheng, Hsiao-Ling

2012-01-15

Arecoline, the most abundant areca alkaloid, has been reported to decrease interleukin-6 (IL-6) levels in epithelial cancer cells. Since IL-6 overexpression contributes to the tumorigenic potency of basal cell carcinoma (BCC), this study was designed to investigate whether arecoline altered IL-6 expression and its downstream regulation of apoptosis and the cell cycle in cultured BCC-1/KMC cells. BCC-1/KMC cells and a human keratinocyte cell line, HaCaT, were treated with arecoline at concentrations ranging from 10 to 100 μg/ml, then IL-6 production and expression of apoptosis- and cell cycle progress-related factors were examined. After 24 h exposure, arecoline inhibited BCC-1/KMC cell growthmore » and decreased IL-6 production in terms of mRNA expression and protein secretion, but had no effect on HaCaT cells. Analysis of DNA fragmentation and chromatin condensation showed that arecoline induced apoptosis of BCC-1/KMC cells in a dose-dependent manner, activated caspase-3, and decreased expression of the anti-apoptotic protein Bcl-2. In addition, arecoline induced progressive and sustained accumulation of BCC-1/KMC cells in G2/M phase as a result of reducing checkpoint Cdc2 activity by decreasing Cdc25C phosphatase levels and increasing p53 levels. Furthermore, subcutaneous injection of arecoline led to decreased BCC-1/KMC tumor growth in BALB/c mice by inducing apoptosis. This study demonstrates that arecoline has potential for preventing BCC tumorigenesis by reducing levels of the tumor cell survival factor IL-6, increasing levels of the tumor suppressor factor p53, and eliciting cell cycle arrest, followed by apoptosis. Highlights: ► Arecoline has potential to prevent against basal cell carcinoma tumorigenesis. ► It has more effectiveness on BCC as compared with a human keratinocyte cell line. ► Mechanisms involved including reducing tumor cells’ survival factor IL-6, ► Decreasing Cdc25C phosphatase, enhancing tumor suppressor factor p53, ► Eliciting G2/M phase arrest, followed by apoptosis.« less

Basal Cell Carcinoma With Matrical Differentiation: Clinicopathologic, Immunohistochemical, and Molecular Biological Study of 22 Cases.

PubMed

Kyrpychova, Liubov; Carr, Richard A; Martinek, Petr; Vanecek, Tomas; Perret, Raul; Chottová-Dvořáková, Magdalena; Zamecnik, Michal; Hadravsky, Ladislav; Michal, Michal; Kazakov, Dmitry V

2017-06-01

Basal cell carcinoma (BCC) with matrical differentiation is a fairly rare neoplasm, with about 30 cases documented mainly as isolated case reports. We studied a series of this neoplasm, including cases with an atypical matrical component, a hitherto unreported feature. Lesions coded as BCC with matrical differentiation were reviewed; 22 cases were included. Immunohistochemical studies were performed using antibodies against BerEp4, β-catenin, and epithelial membrane antigen (EMA). Molecular genetic studies using Ion AmpliSeq Cancer Hotspot Panel v2 by massively parallel sequencing on Ion Torrent PGM were performed in 2 cases with an atypical matrical component (1 was previously subjected to microdissection to sample the matrical and BCC areas separately). There were 13 male and 9 female patients, ranging in age from 41 to 89 years. Microscopically, all lesions manifested at least 2 components, a BCC area (follicular germinative differentiation) and areas with matrical differentiation. A BCC component dominated in 14 cases, whereas a matrical component dominated in 4 cases. Matrical differentiation was recognized as matrical/supramatrical cells (n=21), shadow cells (n=21), bright red trichohyaline granules (n=18), and blue-gray corneocytes (n=18). In 2 cases, matrical areas manifested cytologic atypia, and a third case exhibited an infiltrative growth pattern, with the tumor metastasizing to a lymph node. BerEP4 labeled the follicular germinative cells, whereas it was markedly reduced or negative in matrical areas. The reverse pattern was seen with β-catenin. EMA was negative in BCC areas but stained a proportion of matrical/supramatrical cells. Genetic studies revealed mutations of the following genes: CTNNB1, KIT, CDKN2A, TP53, SMAD4, ERBB4, and PTCH1, with some differences between the matrical and BCC components. It is concluded that matrical differentiation in BCC in most cases occurs as multiple foci. Rare neoplasms manifest atypia in the matrical areas. Immunohistochemical analysis for BerEP4, EMA, and β-catenin can be helpful in limited biopsy specimens. From a molecular biological prospective, BCC and matrical components appear to share some of the gene mutations but have differences in others, but this observation must be validated in a large series.

An expanded study of long-pulsed 1064 nm Nd:YAG laser treatment of basal cell carcinoma.

PubMed

Ortiz, Arisa E; Anderson, R Rox; DiGiorgio, Catherine; Jiang, Shang I Brian; Shafiq, Faiza; Avram, Mathew M

2018-02-13

Basal cell carcinoma (BCC) is an indolent form of skin cancer that is rarely life threatening, but can cause significant cosmetic and functional morbidity. Surgical treatments often result in disfiguring scars, while topical therapies frequently result in recurrence. The need for a more effective nonsurgical alternative has led to the investigation of laser treatment of BCC. We have previously conducted a pilot study which showed 100% histologic clearance at high fluences. Treatments were well tolerated with no significant adverse events. The objective of this larger study was to confirm preliminary results that the 1064 nm Nd:YAG laser is a safe and effective method for treating non-facial BCC. This is an IRB-approved, prospective, multi-center study evaluating the safety and efficacy of the 1064 nm Nd:YAG laser for the treatment of BCC on the trunk and extremities. Thirty-three subjects seeking treatment for biopsy-proven BCC that did not meet the criteria for Mohs surgery were recruited. Subjects on current anticoagulation therapy, or with a history of immunosuppression were excluded. Subjects received one treatment with the 1064 nm Nd:YAG laser as follows: 5-6 mm spot, fluence of 125-140 J/cm 2 and a pulse duration of 7-10 ms. Standard excision with 5 mm clinical margins was performed at 30 days after laser treatment to evaluate clinical and histologic clearance of BCC. Standardized photographs and adverse assessments were taken at the baseline visit, immediately after laser treatment and on the day of excision. Thirty-one subjects completed the study. BCC tumors had a 90% (28 of 31 BCC tumors) histologic clearance rate after one treatment with the long-pulsed 1064 nm Nd:YAG laser. Treatments were generally well tolerated without any anesthesia. Immediate side effects included edema and erythema. At 1-month follow-up, some patients had residual crusting. No significant adverse events occurred. The 1064 nm long-pulsed Nd:YAG laser is an alternative for treating non-facial BCC for those that are poor surgical candidates. Lasers Surg. Med. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

Three-Dimensional Random Voronoi Tessellations: From Cubic Crystal Lattices to Poisson Point Processes

NASA Astrophysics Data System (ADS)

Lucarini, Valerio

2009-01-01

We perturb the simple cubic (SC), body-centered cubic (BCC), and face-centered cubic (FCC) structures with a spatial Gaussian noise whose adimensional strength is controlled by the parameter α and analyze the statistical properties of the cells of the resulting Voronoi tessellations using an ensemble approach. We concentrate on topological properties of the cells, such as the number of faces, and on metric properties of the cells, such as the area, volume and the isoperimetric quotient. The topological properties of the Voronoi tessellations of the SC and FCC crystals are unstable with respect to the introduction of noise, because the corresponding polyhedra are geometrically degenerate, whereas the tessellation of the BCC crystal is topologically stable even against noise of small but finite intensity. Whereas the average volume of the cells is the intensity parameter of the system and does not depend on the noise, the average area of the cells has a rather interesting behavior with respect to noise intensity. For weak noise, the mean area of the Voronoi tessellations corresponding to perturbed BCC and FCC perturbed increases quadratically with the noise intensity. In the case of perturbed SCC crystals, there is an optimal amount of noise that minimizes the mean area of the cells. Already for a moderate amount of noise ( α>0.5), the statistical properties of the three perturbed tessellations are indistinguishable, and for intense noise ( α>2), results converge to those of the Poisson-Voronoi tessellation. Notably, 2-parameter gamma distributions constitute an excellent model for the empirical pdf of all considered topological and metric properties. By analyzing jointly the statistical properties of the area and of the volume of the cells, we discover that also the cells shape, measured by the isoperimetric quotient, fluctuates. The Voronoi tessellations of the BCC and of the FCC structures result to be local maxima for the isoperimetric quotient among space-filling tessellations, which suggests a weaker form of the recently disproved Kelvin conjecture. Moreover, whereas the size of the isoperimetric quotient fluctuations go to zero linearly with noise in the SC and BCC case, the decrease is quadratic in the FCC case. Correspondingly, anomalous scaling relations with exponents larger than 3/2 are observed between the area and the volumes of the cells for all cases considered, and, except for the FCC structure, also for infinitesimal noise. In the Poisson-Voronoi limit, the exponent is ˜1.67. The anomaly in the scaling indicates that large cells preferentially feature large isoperimetric quotients. The FCC structure, in spite of being topologically unstable, results to be the most stable against noise when the shape—as measured by the isoperimetric quotient—of the cells is considered. These scaling relations apply only for a finite range and should be taken as descriptive of the bulk statistical properties of the cells. As the number of faces is strongly correlated with the sphericity (cells with more faces are bulkier), the anomalous scaling is heavily reduced when we perform power law fits separately on cells with a specific number of faces.

Management of periorbital basal cell carcinoma with orbital invasion.

PubMed

Sun, Michelle T; Wu, Albert; Figueira, Edwin; Huilgol, Shyamala; Selva, Dinesh

2015-11-01

Basal cell carcinoma (BCC) is the most common eyelid malignancy; however, orbital invasion by periocular BCC is rare, and management remains challenging. Established risk factors for orbital invasion by BCC include male gender, advanced age, medial canthal location, previous recurrences, large tumor size, aggressive histologic subtype and perineural invasion. Management requires a multidisciplinary approach with orbital exenteration remaining the treatment of choice. Globe-sparing treatment may be appropriate in selected patients and radiotherapy and chemotherapy are often used as adjuvant therapies for advanced or inoperable cases, although the evidence remains limited. We aim to summarize the presentation and treatment of BCC with orbital invasion to better guide the management of this complex condition.

Building and testing a patient-centric electronic bedside communication center.

PubMed

Dykes, Patricia C; Carroll, Diane L; Hurley, Ann C; Benoit, Angela; Chang, Frank; Pozzar, Rachel; Caligtan, Christine A

2013-01-01

In this article, the authors describe the development and pilot testing of an electronic bedside communication center (eBCC) prototype to improve access to health information for hospitalized adults and their family caregivers. Focus groups were used to identify improvements for the initial eBCC prototype developed by the research team. Face-to-face bedside interviews and questions were presented while patients used the eBCC for usability testing to drive further development. Qualitative methods within an iterative, participatory approach supported the development of an eBCC prototype that was considered both easy to use and helpful for accessing tailored patient information during an inpatient hospitalization to receive acute care. Copyright 2013, SLACK Incorporated.

RsaM: a transcriptional regulator of Burkholderia spp. with novel fold

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michalska, Karolina; Chhor, Gekleng; Clancy, Shonda

2014-07-04

Burkholderia cepacia complex (Bcc) is a set of closely related bacterial species that are notorious pathogens of cystic fibrosis patients, responsible for life-threatening lung infections. Expression of several virulence factors of Bcc is controlled by a mechanism known as quorum sensing (QS). QS is a means of bacterial communication used to coordinate gene expression in a cell-density-dependent manner. The system involves the production of diffusible signaling molecules (N-acyl-L-homoserine lactones, AHLs), that bind to cognate transcriptional regulators and influence their ability to regulate gene expression. One such system that is highly conserved in Bcc consists of CepI and CepR. CepI ismore » AHL synthase, while CepR is an AHL-dependent transcription factor. In most members of the Bcc group, the cepI and cepR genes are divergently transcribed and separated by additional genes. One of them, bcam1869, encodes the BcRsaM protein, which was recently postulated to modulate the abundance or activity of CepI or CepR. Here we show the crystal structure of BcRsaM from B. cenocepacia J2315. It is a single-domain protein with unique topology and presents a novel fold. The protein is a dimer in the crystal and in solution. This regulator has no known DNA binding motifs and direct binding of BcRsaM to the cepI promoter could not be detected in in vitro assays. Therefore, we propose that the modulatory action of RsaM might result from interactions with other components of the QS machinery rather than from direct association with the DNA promoter.« less

980nm laser for difficult-to-treat basal cell carcinoma

NASA Astrophysics Data System (ADS)

Derjabo, A. D.; Cema, I.; Lihacova, I.; Derjabo, L.

2013-06-01

Begin basal cell carcinoma (BCC) is most common skin cancer over the world. There are around 20 modalities for BCC treatment. Laser surgery is uncommon option. We demonstrate our long term follow up results. Aim: To evaluate long term efficacy of a 980nm diode laser for the difficult-to-treat basal cell carcinoma. Materials and Methods: 167 patients with 173 basal cell carcinoma on the nose were treated with a 980 nm diode laser from May 1999 till May 2005 at Latvian Oncology center. All tumors were morphologically confirmed. 156 patients were followed for more than 5 years. Results: The lowest recurrence rate was observed in cases of superficial BCC, diameter<6mm bet the highest recurrence rate was in cases of infiltrative BCC and nodular recurrent BCC. Conclusions: 980 nm diode laser is useful tool in dermatology with high long term efficacy, good acceptance by the patients and good cosmetics results.

Vismodegib Therapy for Basal Cell Carcinoma in an 8-Year-Old Chinese Boy with Xeroderma Pigmentosum.

PubMed

Fife, Douglas; Laitinen, Marko A; Myers, David J; Landsteiner, Pamela B

2017-03-01

Vismodegib is an oral inhibitor of the Hedgehog signaling pathway and has been used to treat basal cell carcinoma (BCC) in adults. This article reports clearance of a nodular BCC of the nasal tip in an 8-year-old boy with xeroderma pigmentosum (XP). BCC can pose therapeutic challenges when located in areas that are not amenable to traditional therapies such as Mohs micrographic surgery or topical agents. Vismodegib was used at a dose of 150 mg/day to treat the boy's BCC. After 4 months of therapy, we achieved complete clinical clearance. During 21 months of follow-up, the patient's nose remained clinically clear of tumor. Vismodegib was successfully used to treat a child with XP and nodular BCC. Our goal in using vismodegib was tumor regression while avoiding cosmetic and functional disfigurement. Vismodegib was effective in clinically clearing the tumor, and the patient has shown no signs of recurrence. Further studies are warranted. © 2017 Wiley Periodicals, Inc.

Reentrant behavior in the nearest-neighbor Ising antiferromagnet in a magnetic field

NASA Astrophysics Data System (ADS)

Neto, Minos A.; de Sousa, J. Ricardo

2004-12-01

Motived by the H-T phase diagram in the bcc Ising antiferromagnetic with nearest-neighbor interactions obtained by Monte Carlo simulation [Landau, Phys. Rev. B 16, 4164 (1977)] that shows a reentrant behavior at low temperature, with two critical temperatures in magnetic field about 2% greater than the critical value Hc=8J , we apply the effective field renormalization group (EFRG) approach in this model on three-dimensional lattices (simple cubic-sc and body centered cubic-bcc). We find that the critical curve TN(H) exhibits a maximum point around of H≃Hc only in the bcc lattice case. We also discuss the critical behavior by the effective field theory in clusters with one (EFT-1) and two (EFT-2) spins, and a reentrant behavior is observed for the sc and bcc lattices. We have compared our results of EFRG in the bcc lattice with Monte Carlo and series expansion, and we observe a good accordance between the methods.

Eliminating Plasmodium falciparum in Hainan, China: a study on the use of behavioural change communication intervention to promote malaria prevention in mountain worker populations.

PubMed

He, Chang-hua; Hu, Xi-min; Wang, Guang-ze; Zhao, Wei; Sun, Ding-wei; Li, Yu-chun; Chen, Chun-xiang; Du, Jian-wei; Wang, Shan-qing

2014-07-13

In the island of Hainan, the great majority of malaria cases occur in mountain worker populations. Using the behavioral change communication (BCC) strategy, an interventional study was conducted to promote mountain worker malaria prevention at a test site. This study found the methods and measures that are suitable for malaria prevention among mountain worker populations. During the Plasmodium falciparum elimination stage in Hainan, a representative sampling method was used to establish testing and control sites in areas of Hainan that were both affected by malaria and had a relatively high density of mountain workers. Two different methods were used: a BCC strategy and a conventional strategy as a control. Before and after the intervention, house visits, core group discussions, and structural surveys were utilized to collect qualitative and quantitative data regarding mountain worker populations (including knowledge, attitudes, and practices [KAPs]; infection status; and serological data), and these data from the testing and control areas were compared to evaluate the effectiveness of BCC strategies in the prevention of malaria. In the BCC malaria prevention strategy testing areas, the accuracy rates of malaria-related KAP were significantly improved among mountain worker populations. The accuracy rates in the 3 aspects of malaria-related KAP increased from 37.73%, 37.00%, and 43.04% to 89.01%, 91.53%, and 92.25%, respectively. The changes in all 3 aspects of KAP were statistically significant (p < 0.01). In the control sites, the changes in the indices were not as marked as in the testing areas, and the change was not statistically significant (p > 0.05). Furthermore, in the testing areas, both the percentage testing positive in the serum malaria indirect fluorescent antibody test (IFAT) and the number of people inflicted decreased more significantly than in the control sites (p < 0.01). The use of the BCC strategy significantly improved the ability of mountain workers in Hainan to avoid malarial infection. Educational and promotional materials and measures were developed and selected in the process, and hands-on experience was gained that will help achieve the goal of total malaria elimination in Hainan.

Evaluation of Hypoxia Inducible Factor-1α and Glucose Transporter-1 Expression in Non Melanoma Skin Cancer: An Immunohistochemical Study

PubMed Central

Seleit, Iman; Bakry, Ola Ahmed; Ragab, Rania Abdel Aziz; Al-Shiemy, shimaa Ahmed

2017-01-01

Introduction Hypoxia Inducible Factor-1 (HIF-1) is a mediator enabling cell adaptation to hypoxia. It plays its role mainly through transcription of many target genes including Glucose Transporter-1 (GLUT-1) gene. Aim The present work aimed at evaluating the pattern and distribution of HIF-1α and GLUT-1 in each case and control. Materials and Methods A case-control and retrospective study was conducted on archival blocks diagnosed from pathology department as, Basal Cell Carcinoma (BCC, 20 cases), cutaneous Squamous Cell Carcinoma (SCC, 20 cases) and 20 normal site-matched skin biopsies from age and gender-matched healthy subjects as a control. Evaluation of both HIF-1α and GLUT1 expression using standard immunohistochemical techniques was performed on cut sections from selected paraffin embedded blocks. Results HIF-1α was expressed in 90%, 35% and 100% of normal skin, BCC and SCC tumour islands respectively. It was up regulated in both BCC and SCC compared with normal skin (p= 0.001, p<0.001 respectively). GLUT-1 was expressed in 100%, 70% and 100% of normal skin, BCC and SCC tumour islands respectively. It was down regulated in Non Melanoma Skin Cancer (NMSC) cases compared with normal skin (p=0.004). HIF-1α and GLUT-1 localization in tumour nests was central, peripheral or central and peripheral. Both HIF-1α and GLUT-1 showed variable expression in stroma, adnexa and inflammatory cells. No significant correlation was found between Histo (H) score or expression percentage values of HIF-1α and those of GLUT-1 in tumour islands or in overlying epidermis either in BCC or SCC. Conclusion HIF-1α may have a role in NMSC pathogenesis through adaptation to hypoxia which results from excessive proliferation. GLUT-1 down regulation in NMSC may be explained by its consumption by proliferating tumour cells. The expression of HIF-1α and GLUT-1 in normal epidermis, stromal and adnexal structures needs further research. PMID:28764171

Height, height-related SNPs, and risk of non-melanoma skin cancer.

PubMed

Li, Xin; Liang, Liming; Feng, Yen-Chen Anne; De Vivo, Immaculata; Giovannucci, Edward; Tang, Jean Y; Han, Jiali

2017-01-03

Adult height has been associated with risk of several site-specific cancers, including melanoma. However, less attention has been given to non-melanoma skin cancer (NMSC). We prospectively examined the risk of squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) in relation to adult height in the Nurses' Health Study (NHS, n=117 863) and the Health Professionals Follow-up Study (HPFS, n=51 111). We also investigated the relationships between height-related genetic markers and risk of BCC and SCC in the genetic data sets of the NHS and HPFS (3898 BCC cases, and 8530 BCC controls; 527 SCC cases, and 8962 SCC controls). After controlling for potential confounding factors, the hazard ratios were 1.09 (95% CI: 1.02, 1.15) and 1.10 (95% CI: 1.07, 1.13) for the associations between every 10 cm increase in height and risk of SCC and BCC respectively. None of the 687 height-related single-nucleotide polymorphisms (SNPs) was significantly associated with the risk of SCC or BCC, nor were the genetic scores combining independent height-related loci. Our data from two large cohorts provide further evidence that height is associated with an increased risk of NMSC. More studies on height-related genetic loci and early-life exposures may help clarify the underlying mechanisms.

Evaluation of Dogs with Border Collie Collapse, Including Response to Two Standardized Strenuous Exercise Protocols.

PubMed

Taylor, Susan; Shmon, Cindy; Su, Lillian; Epp, Tasha; Minor, Katie; Mickelson, James; Patterson, Edward; Shelton, G Diane

2016-01-01

Clinical and metabolic variables were evaluated in 13 dogs with border collie collapse (BCC) before, during, and following completion of standardized strenuous exercise protocols. Six dogs participated in a ball-retrieving protocol, and seven dogs participated in a sheep-herding protocol. Findings were compared with 16 normal border collies participating in the same exercise protocols (11 retrieving, five herding). Twelve dogs with BCC developed abnormal mentation and/or an abnormal gait during evaluation. All dogs had post-exercise elevations in rectal temperature, pulse rate, arterial blood pH, PaO2, and lactate, and decreased PaCO2 and bicarbonate, as expected with strenuous exercise, but there were no significant differences between BCC dogs and normal dogs. Electrocardiography demonstrated sinus tachycardia in all dogs following exercise. Needle electromyography was normal, and evaluation of muscle biopsy cryosections using a standard panel of histochemical stains and reactions did not reveal a reason for collapse in 10 dogs with BCC in which these tests were performed. Genetic testing excluded the dynamin-1 related exercise-induced collapse mutation and the V547A malignant hyperthermia mutation as the cause of BCC. Common reasons for exercise intolerance were eliminated. Although a genetic basis is suspected, the cause of collapse in BCC was not determined.

Uhlenbeck-Ford model: Phase diagram and corresponding-states analysis

NASA Astrophysics Data System (ADS)

Paula Leite, Rodolfo; Santos-Flórez, Pedro Antonio; de Koning, Maurice

2017-09-01

Using molecular dynamics simulations and nonequilibrium thermodynamic-integration techniques we compute the Helmholtz free energies of the body-centered-cubic (bcc), face-centered-cubic (fcc), hexagonal close-packed, and fluid phases of the Uhlenbeck-Ford model (UFM) and use the results to construct its phase diagram. The pair interaction associated with the UFM is characterized by an ultrasoft, purely repulsive pair potential that diverges logarithmically at the origin. We find that the bcc and fcc are the only thermodynamically stable crystalline phases in the phase diagram. Furthermore, we report the existence of two reentrant transition sequences as a function of the number density, one featuring a fluid-bcc-fluid succession and another displaying a bcc-fcc-bcc sequence near the triple point. We find strong resemblances to the phase behavior of other soft, purely repulsive systems such as the Gaussian-core model (GCM), inverse-power-law, and Yukawa potentials. In particular, we find that the fcc-bcc-fluid triple point and the phase boundaries in its vicinity are in good agreement with the prediction supplied by a recently proposed corresponding-states principle [J. Chem. Phys. 134, 241101 (2011), 10.1063/1.3605659; Europhys. Lett. 100, 66004 (2012), 10.1209/0295-5075/100/66004]. The particularly strong resemblance between the behavior of the UFM and GCM models are also discussed.

Basal cell skin cancer and the risk of second primary cancers: a cancer registry-based study in Lithuania.

PubMed

Krilaviciute, Agne; Vincerzevskiene, Ieva; Smailyte, Giedre

2016-07-01

The aim of this population-based cohort study was to determine the risk of second primary cancer in basal cell carcinoma (BCC) patients in Lithuania. This analysis was based on patients diagnosed with BCC in Lithuania between 1998 and 2007 and followed until 2011. Standardized incidence ratios for subsequent cancers as a ratio of observed number of cancer cases in people with previous BCC diagnosis to the expected number of cancer cases in the underlying general population were calculated. After diagnosis of BCC, 1442 new cases of selected cancers were diagnosed. Compared with the general population, the incidence of all new primaries combined after BCC was very close to expected. Statistically meaningful increase in developing subsequent cancer was obtained for Hodgkin's lymphoma, prostate cancer, and leukemia in men, and for cancers of the lip, lung, and breast in women. Risk of melanoma and thyroid cancer was significantly elevated in both sexes. Relative risk of cancer of the eye was increased although not significant. In our study, we found increased cancer risk for cancers related to sun exposure. In addition, increased risks were identified for Hodgkin's lymphoma, thyroid cancer, leukemia, prostate, and breast cancer in BCC patients. Copyright © 2016 Elsevier Inc. All rights reserved.

Red Dot Basal Cell Carcinoma: An Unusual Variant of a Common Malignancy.

PubMed

Loh, Tiffany Y; Cohen, Philip R

2016-05-01

Red dot basal cell carcinoma is a distinct but rare subtype of basal cell carcinoma (BCC). It presents as a red macule or papule; therefore, in most cases, it may easily be mistaken for a benign vascular lesion, such as a telangiectasia or angioma.
A red dot BCC in an older woman is described. Clinical and histological differences between red dot BCCs and telangiectasias are described.
A 72-year-old woman initially presented with a painless red macule on her nose. Biopsy of the lesion established the diagnosis of a red dot BCC. Pubmed was searched for the following terms: angioma, basal cell carcinoma, dermoscope, diascopy, red dot, non-melanoma skin cancer, telangiectasia, and vascular. The papers were reviewed for cases of red dot basal cell carcinoma. Clinical and histological characteristics of red dot basal cell carcinoma and telangiectasias were compared.
Red dot BCC is an extremely rare variant of BCC that may be confused with benign vascular lesions. Although BCCs rarely metastasize and are associated with low mortality, they have the potential to become locally invasive and destructive if left untreated. Thus, a high index of suspicion for red dot BCC is necessary.

J Drugs Dermatol. 2016;15(5):645-647.

The burden of non-melanoma skin cancers in Auckland, New Zealand.

PubMed

Pondicherry, Ashwini; Martin, Richard; Meredith, Ineke; Rolfe, Jack; Emanuel, Patrick; Elwood, Mark

2018-01-19

As the New Zealand Cancer Registry does not require mandatory reporting of non-melanoma skin cancers (NMSC), basal cell carcinomas (BCC) and squamous cell carcinomas (SCC), the clinical burden of these diseases is unknown. A retrospective review of all patients with histopathology performed allowed us to estimate invasive BCC and SCC in the Auckland region in 2008 (population 1.44 million). During this period, a total of 21 236 NMSC were diagnosed among 13 996 patients, consisting of 5611 SCC lesions (26%) and 15 525 (74%) BCC. The Auckland incidence rates per 100 000 were 425 for SCC and 1177 for BCC. The overall rate of NMSC per 100 000 was 1906.5 (standardised to the census data of Australia 2001); 1385 for BCC and 522 for SCC. Using published data on incidence trends and population growth, we estimate that 29 000-33 000 NMSC would have been excised in Auckland in 2016, and 78 000-87 000 in New Zealand. Auckland has the highest reported incidence of invasive NMSC in the world. We believe that high-risk cutaneous SCC and complex BCC should be recorded. Our study provides information for clinicians and health economists on the scale of the problem. © 2018 The Australasian College of Dermatologists.

Cohort study of Gorlin syndrome with emphasis on standardised phenotyping and quality of life assessment.

PubMed

Huq, Aamira J; Bogwitz, Michael; Gorelik, Alexandra; Winship, Ingrid M; White, Susan M; Trainer, Alison H

2017-06-01

Gorlin syndrome (nevoid basal cell carcinoma syndrome) is a rare genetic predisposition to basal cell carcinomas (BCC), keratocysts of the jaw and calcification of the falx cerebri among other clinical features. With the advent of sonic hedgehog inhibitors for the treatment of BCC, it is timely to establish a cohort of individuals with Gorlin syndrome and collect standardised phenotypic information on these individuals. Moreover, the health-related quality of life (QoL) in individuals with Gorlin syndrome is not well studied. To establish a Victorian cohort of Gorlin syndrome and study the QoL in these individuals. Phenotypic data were obtained by reviewing medical records of individuals attending two major tertiary/quaternary genetic referral centres in Victoria, followed by telephone or face-to-face interviews where possible. QoL information was obtained utilising the AQoL-6D quality of life survey form. The median number of BCC in the 19 individuals studied was 17.5 (interquartile range 3-70). The number of patients with ≥100 BCC in this group was similar to a previously described national cohort (22.2 vs 27% respectively). A total of 58% of referrals to the genetics clinics originated from maxillofacial surgeons and 42% from dermatologists. Individuals with ≥100 BCC had worse median QoL scores compared to those with <100 BCC (36 vs 29, P-value of 0.031). The clinical features in our cohort were congruent with those previously described in Australia. The QoL is adversely correlated with increased BCC burden. © 2017 Royal Australasian College of Physicians.

Burkholderia cepacia complex in Serbian patients with cystic fibrosis: prevalence and molecular epidemiology.

PubMed

Vasiljevic, Z V; Novovic, K; Kojic, M; Minic, P; Sovtic, A; Djukic, S; Jovcic, B

2016-08-01

The Burkholderia cepacia complex (Bcc) organisms remain significant pathogens in patients with cystic fibrosis (CF). This study was performed to evaluate the prevalence, epidemiological characteristics, and presence of molecular markers associated with virulence and transmissibility of the Bcc strains in the National CF Centre in Belgrade, Serbia. The Bcc isolates collected during the four-year study period (2010-2013) were further examined by 16 s rRNA gene, pulsed-field gel electrophoresis of genomic DNA, multilocus sequence typing analysis, and phylogenetic analysis based on concatenated sequence of seven alleles. Fifty out of 184 patients (27.2 %) were colonized with two Bcc species, B. cenocepacia (n = 49) and B. stabilis (n = 1). Thirty-four patients (18.5 %) had chronic colonization. Typing methods revealed a high level of similarity among Bcc isolates, indicating a person-to-person transmission or acquisition from a common source. New sequence types (STs) were identified, and none of the STs with an international distribution were found. One centre-specific ST, B. cenocepacia ST856, was highly dominant and shared by 48/50 (96 %) patients colonized by Bcc. This clone was characterized by PCR positivity for both the B. cepacia epidemic strain marker and cable pilin, and showed close genetic relatedness to the epidemic strain CZ1 (ST32). These results indicate that the impact of Bcc on airway colonization in the Serbian CF population is high and virtually exclusively limited to a single clone of B. cenocepacia. The presence of a highly transmissible clone and probable patient-to-patient spread was observed.

Citrus consumption and risk of basal cell carcinoma and squamous cell carcinoma of the skin.

PubMed

Wu, Shaowei; Cho, Eunyoung; Feskanich, Diane; Li, Wen-Qing; Sun, Qi; Han, Jiali; Qureshi, Abrar A

2015-10-01

Animal experiments have demonstrated the photocarcinogenic properties of furocoumarins, a group of naturally occurring chemicals that are rich in citrus products. We conducted a prospective study for citrus consumption and risk of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) of the skin based on data from 41530 men in the Health Professionals Follow-up Study (1986-2010) and 63759 women in the Nurses' Health Study (1984-2010) who were free of cancers at baseline. Over 24-26 years of follow-up, we documented 20840 incident BCCs and 3544 incident SCCs. Compared to those who consumed citrus products less than twice per week, the pooled multivariable-adjusted hazard ratios were 1.03 [95% confidence interval (95% CI): 0.99-1.08] for BCC and 1.14 (95% CI: 1.00-1.30) for SCC for those who consumed two to four times per week, 1.06 (95% CI: 1.01-1.11) for BCC and 1.15 (95% CI: 1.02-1.28) for SCC for five to six times per week, 1.11 (95% CI: 1.06-1.16) for BCC and 1.22 (95% CI: 1.08-1.37) for SCC for once to 1.4 times per day and 1.16 (95% CI: 1.09-1.23) for BCC and 1.21 (95% Cl: 1.06-1.38) for SCC for 1.5 times per day or more (P trend = 0.001 for BCC and 0.04 for SCC). In contrast, consumption of non-citrus fruit and juice appeared to be inversely associated with risk of BCC and SCC. Our findings support positive associations between citrus consumption and risk of cutaneous BCC and SCC in two cohorts of men and women, and call for further investigations to better understand the potential photocarcinogenesis associated with dietary intakes. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Citrus consumption and risk of basal cell carcinoma and squamous cell carcinoma of the skin

PubMed Central

Wu, Shaowei; Cho, Eunyoung; Feskanich, Diane; Li, Wen-Qing; Sun, Qi; Han, Jiali; Qureshi, Abrar A.

2015-01-01

Animal experiments have demonstrated the photocarcinogenic properties of furocoumarins, a group of naturally occurring chemicals that are rich in citrus products. We conducted a prospective study for citrus consumption and risk of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) of the skin based on data from 41530 men in the Health Professionals Follow-up Study (1986–2010) and 63759 women in the Nurses’ Health Study (1984–2010) who were free of cancers at baseline. Over 24–26 years of follow-up, we documented 20840 incident BCCs and 3544 incident SCCs. Compared to those who consumed citrus products less than twice per week, the pooled multivariable-adjusted hazard ratios were 1.03 [95% confidence interval (95% CI): 0.99–1.08] for BCC and 1.14 (95% CI: 1.00–1.30) for SCC for those who consumed two to four times per week, 1.06 (95% CI: 1.01–1.11) for BCC and 1.15 (95% CI: 1.02–1.28) for SCC for five to six times per week, 1.11 (95% CI: 1.06–1.16) for BCC and 1.22 (95% CI: 1.08–1.37) for SCC for once to 1.4 times per day and 1.16 (95% CI: 1.09–1.23) for BCC and 1.21 (95% Cl: 1.06–1.38) for SCC for 1.5 times per day or more (P trend = 0.001 for BCC and 0.04 for SCC). In contrast, consumption of non-citrus fruit and juice appeared to be inversely associated with risk of BCC and SCC. Our findings support positive associations between citrus consumption and risk of cutaneous BCC and SCC in two cohorts of men and women, and call for further investigations to better understand the potential photocarcinogenesis associated with dietary intakes. PMID:26224304

Composition design for Laves phase-related body-centered cubic-V solid solution alloys with large hydrogen storage capacities.

PubMed

Wang, H B; Wang, Q; Dong, C; Yuan, L; Xu, F; Sun, L X

2008-03-19

This paper analyzes the characteristics of alloy compositions with large hydrogen storage capacities in Laves phase-related body-centered cubic (bcc) solid solution alloy systems using the cluster line approach. Since a dense-packed icosahedral cluster A(6)B(7) characterizes the local structure of AB(2) Laves phases, in an A-B-C ternary system, such as Ti-Cr (Mn, Fe)-V, where A-B forms AB(2) Laves phases while A-C and B-C tend to form solid solutions, a cluster line A(6)B(7)-C is constructed by linking A(6)B(7) to C. The alloy compositions with large hydrogen storage capacities are generally located near this line and are approximately expressed with the cluster-plus-glue-atom model. The cluster line alloys (Ti(6)Cr(7))(100-x)V(x) (x = 2.5-70 at.%) exhibit different structures and hence different hydrogen storage capacities with increasing V content. The alloys (Ti(6)Cr(7))(95)V(5) and Ti(30)Cr(40)V(30) with bcc solid solution structure satisfy the cluster-plus-glue-atom model.

Automatic telangiectasia analysis in dermoscopy images using adaptive critic design.

PubMed

Cheng, B; Stanley, R J; Stoecker, W V; Hinton, K

2012-11-01

Telangiectasia, tiny skin vessels, are important dermoscopy structures used to discriminate basal cell carcinoma (BCC) from benign skin lesions. This research builds off of previously developed image analysis techniques to identify vessels automatically to discriminate benign lesions from BCCs. A biologically inspired reinforcement learning approach is investigated in an adaptive critic design framework to apply action-dependent heuristic dynamic programming (ADHDP) for discrimination based on computed features using different skin lesion contrast variations to promote the discrimination process. Lesion discrimination results for ADHDP are compared with multilayer perception backpropagation artificial neural networks. This study uses a data set of 498 dermoscopy skin lesion images of 263 BCCs and 226 competitive benign images as the input sets. This data set is extended from previous research [Cheng et al., Skin Research and Technology, 2011, 17: 278]. Experimental results yielded a diagnostic accuracy as high as 84.6% using the ADHDP approach, providing an 8.03% improvement over a standard multilayer perception method. We have chosen BCC detection rather than vessel detection as the endpoint. Although vessel detection is inherently easier, BCC detection has potential direct clinical applications. Small BCCs are detectable early by dermoscopy and potentially detectable by the automated methods described in this research. © 2011 John Wiley & Sons A/S.

First-principles study of the structural and elastic properties of AuxV1-x and AuxNb1-x alloys

NASA Astrophysics Data System (ADS)

Al-Zoubi, N.

2018-04-01

Ab initio total energy calculations, based on the Exact Muffin-Tin Orbitals (EMTO) method in combination with the coherent potential approximation (CPA), are used to calculate the total energy of AuxV1-x and AuxNb1-x random alloys along the Bain path that connects the body-centred cubic (bcc) and face-centred cubic (fcc) structures as a function of composition x (0 ≤ x ≤ 1). The equilibrium Wigner-Seitz radius and the elastic properties of both systems are determined as a function of composition. Our theoretical prediction in case of pure elements (x = 0 or x = 1) are in good agreement with the available experimental data. For the Au-V system, the equilibrium Wigner-Seitz radius increase as x increases, while for the Au-Nb system, the equilibrium Wigner-Seitz radius is almost constant. The bulk modulus B and C44 for both alloys exhibit nearly parabolic trend. On the other hand, the tetragonal shear elastic constant C‧ decreases as x increases and correlates reasonably well with the structural energy difference between fcc and bcc structures. Our results offer a consistent starting point for further theoretical and experimental studies of the elastic and micromechanical properties of Au-V and Au-Nb systems.

Basal Cell Carcinoma: Pathogenesis, Epidemiology, Clinical Features, Diagnosis, Histopathology, and Management

PubMed Central

Marzuka, Alexander G.; Book, Samuel E.

2015-01-01

Basal cell carcinoma (BCC) is the most common malignancy. Exposure to sunlight is the most important risk factor. Most, if not all, cases of BCC demonstrate overactive Hedgehog signaling. A variety of treatment modalities exist and are selected based on recurrence risk, importance of tissue preservation, patient preference, and extent of disease. The pathogenesis, epidemiology, clinical features, diagnosis, histopathology, and management of BCC will be discussed in this review. PMID:26029015

Efficient Ab initio Modeling of Random Multicomponent Alloys

DOE PAGES

Jiang, Chao; Uberuaga, Blas P.

2016-03-08

Here, we present in this Letter a novel small set of ordered structures (SSOS) method that allows extremely efficient ab initio modeling of random multi-component alloys. Using inverse II-III spinel oxides and equiatomic quinary bcc (so-called high entropy) alloys as examples, we also demonstrate that a SSOS can achieve the same accuracy as a large supercell or a well-converged cluster expansion, but with significantly reduced computational cost. In particular, because of this efficiency, a large number of quinary alloy compositions can be quickly screened, leading to the identification of several new possible high entropy alloy chemistries. Furthermore, the SSOS methodmore » developed here can be broadly useful for the rapid computational design of multi-component materials, especially those with a large number of alloying elements, a challenging problem for other approaches.« less

SOME RARE-EARTH ALLOY SYSTEMS. I. La-Gd, La-Y, Gd-Y

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spedding, F.H.; Valletta, R.M.; Daane, A.H.

The La-Y, La--Gd, and Gd--Y alloy systems were examined by conventional metallurgical research techniques. As would be expected from the similarity of the parent metals, the Gd--Y system exhibits complete solid solubility across the system in both the alpha and beta regions, with nearly perfect behavior indicated by the essentially linear plots of lattice constants and other related data, The La--Y and La--Gd systems show complete solid solubility in the high temperature bcc region, with limited solubility in the room temperature forms. In the central region of these two systems at room temperature, an ordered phase with the samarium structuremore » is observed, Some correlation of structure and lattice constants of this phase with the properties of the related pure metals is observed. (auth)« less

Exceptional bone metastasis of basal cell carcinoma in Gorlin-Goltz syndrome.

PubMed

Lamon, Tatiana; Gerard, Stephane; Meyer, Nicolas; Losfeld, Benjamin; Abellan van Kan, Gabor; Balardy, Laurent; Vellas, Bruno

2010-01-01

Basal cell carcinoma (BCC), the most prevalent form of cancer worldwide, is a malignant skin neoplasm. It is locally invasive, with an exceptional incidence of reported metastasis. It can also be part of the Gorlin-Goltz syndrome, an autosomal dominant genetic disorder with high penetrance and variable expressivity, which is principally characterized by cutaneous BCC, odontogenic keratocysts, palmar and/or plantar pits, and falx cerebri calcification. We report the exceptional clinical observation of a 54-year-old man presenting bone metastasis from BCC in Gorlin-Goltz syndrome. Less than 300 cases of metastatic BCC have been reported in the literature. The present case is the second associated with Gorlin-Goltz syndrome. Copyright 2009 S. Karger AG, Basel.

Phase transition and strength of vanadium under shock compression up to 88 GPa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Yuying, E-mail: yuyinyu@caep.cn; Tan, Ye; Dai, Chengda

A series of reverse-impact experiments were performed on vanadium at shock pressure ranging from 32 GPa to 88 GPa. Particle velocity profiles measured at sample/LiF window interface were used to estimate the sound velocities, shear modulus, and yield stress in shocked vanadium. A phase transition at ∼60.5 GPa that may be the body-centered cubic (BCC) to rhombohedral structure was identified by the discontinuity of the sound velocity against shock pressure. This transition pressure is consistent with the results from diamond anvil cell (DAC) experiments and first-principle calculations. However, present results show that the rhombohedral phase has higher strength and shear modulus than themore » BCC phase, which is contrast to the findings from DAC experiments and theoretical work.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Travesset, Alex

An extensive characterization of the low temperature phase diagram of particles interacting with power law or Lennard-Jones potentials is provided from Lattice Dynamical Theory. For power law systems, only two lattice structures are stable for certain values of the exponent (or softness) (A15, body centered cube (bcc)) and two more (face centered cubic (fcc), hexagonal close packed (hcp)) are always stable. Among them, only the fcc and bcc are equilibrium states. For Lennard-Jones systems, the equilibrium states are either hcp or fcc, with a coexistence curve in pressure and temperature that shows reentrant behavior. The hcp solid never coexists withmore » the liquid. In all cases analyzed, for both power law and Lennard-Jones potentials, the fcc crystal has higher entropy than the hcp. The role of anharmonic terms is thoroughly analyzed and a general thermodynamic integration to account for them is proposed.« less

Epitaxy of Fe/Cu/Si(1 1 1) ultrathin films: an Auger electron diffraction study

NASA Astrophysics Data System (ADS)

Castrucci, P.; Gunnella, R.; Bernardini, R.; Montecchiari, A.; Carboni, R.; De Crescenzi, M.

2001-06-01

Epitaxial Fe films, with thickness in the range between 1 and 50 ML (monolayer, ML), were grown in ultrahigh vacuum conditions on the 7×7 reconstructed (1 1 1)-Si surface. The films were evaporated on a Cu thick buffer layer to avoid iron silicides formation. Auger electron diffraction (AED) technique has been used to investigate the growth of the pseudomorphic film of fcc γ-Fe(1 1 1) and the successive growth of bcc Fe(1 1 0) domains in the Kurdjumov-Sachs orientation. The early stages of growth have been carefully investigated through AED to assess the pseudomorphism of iron γ-phase. AED patterns clearly show the presence of diffraction features that are fingerprints of the existence of a few bcc arranged atomic structures even for 1 ML iron coverage.

Ground-state ordering of the J1-J2 model on the simple cubic and body-centered cubic lattices

NASA Astrophysics Data System (ADS)

Farnell, D. J. J.; Götze, O.; Richter, J.

2016-06-01

The J1-J2 Heisenberg model is a "canonical" model in the field of quantum magnetism in order to study the interplay between frustration and quantum fluctuations as well as quantum phase transitions driven by frustration. Here we apply the coupled cluster method (CCM) to study the spin-half J1-J2 model with antiferromagnetic nearest-neighbor bonds J1>0 and next-nearest-neighbor bonds J2>0 for the simple cubic (sc) and body-centered cubic (bcc) lattices. In particular, we wish to study the ground-state ordering of these systems as a function of the frustration parameter p =z2J2/z1J1 , where z1 (z2) is the number of nearest (next-nearest) neighbors. We wish to determine the positions of the phase transitions using the CCM and we aim to resolve the nature of the phase transition points. We consider the ground-state energy, order parameters, spin-spin correlation functions, as well as the spin stiffness in order to determine the ground-state phase diagrams of these models. We find a direct first-order phase transition at a value of p =0.528 from a state of nearest-neighbor Néel order to next-nearest-neighbor Néel order for the bcc lattice. For the sc lattice the situation is more subtle. CCM results for the energy, the order parameter, the spin-spin correlation functions, and the spin stiffness indicate that there is no direct first-order transition between ground-state phases with magnetic long-range order, rather it is more likely that two phases with antiferromagnetic long range are separated by a narrow region of a spin-liquid-like quantum phase around p =0.55 . Thus the strong frustration present in the J1-J2 Heisenberg model on the sc lattice may open a window for an unconventional quantum ground state in this three-dimensional spin model.

First-principles analysis of C2H2 molecule diffusion and its dissociation process on the ferromagnetic bcc-Fe110 surface.

PubMed

Ikeda, Minoru; Yamasaki, Takahiro; Kaneta, Chioko

2010-09-29

Using the projector-augmented plane wave method, we study diffusion and dissociation processes of C(2)H(2) molecules on the ferromagnetic bcc-Fe(110) surface and investigate the formation process of graphene created by C(2)H(2) molecules. The most stable site for C(2)H(2) on the Fe surface is a hollow site and its adsorption energy is - 3.5 eV. In order to study the diffusion process of the C(2)H(2) molecule, the barrier height energies for the C atom, C(2)-dimer and CH as well as the C(2)H(2) molecule are estimated using the nudged elastic band method. The barrier height energy for C(2)H(2) is 0.71 eV and this indicates that the C(2)H(2) diffuses easily on this FM bcc-Fe(110) surface. We further investigate the two step dissociation process of C(2)H(2) on Fe. The first step is the dissociation of C(2)H(2) into C(2)H and H, and the second step is that of C(2)H into C(2) and H. Their dissociation energies are 0.9 and 1.2 eV, respectively. These energies are relatively small compared to the dissociation energy 7.5 eV of C(2)H(2) into C(2)H and H in the vacuum. Thus, the Fe surface shows catalytic effects. We further investigate the initial formation process of graphene by increasing the coverage of C(2)H(2). The formation process of the benzene molecule on the FM bcc(110) surface is also discussed. We find that there exists a critical coverage of C(2)H(2) which characterizes the beginning of the formation of the graphene.

Common variants modify the age of onset for basal cell carcinomas in Gorlin syndrome.

PubMed

Yasar, Binnaz; Byers, Helen J; Smith, Miriam J; Lear, John; Oudit, Deemesh; Bholah, Zaynab; Roberts, Stephen A; Newman, William G; Evans, D Gareth

2015-05-01

Gorlin syndrome is an autosomal dominant disorder, characterized by multiple early-onset basal cell carcinomas (BCCs) and jaw keratocysts. Through association studies in cohorts of sporadic BCC, nine genetic variants have previously been identified to increase the risk of BCC. The nine SNPs were genotyped by Taqman allelic discrimination in 125 individuals with Gorlin syndrome. Kaplan-Meier survival curves and Cox proportional-Hazard regression analysis were applied to determine the association between genotypes and age of first BCC in individuals with Gorlin syndrome. The p.(Arg151Cys) variant in MC1R (rs1805007) was associated with an earlier median age of onset of BCC of 27 years (95% CI: 20-34) compared with 34 years (95% CI: 30-40) for wild-type individuals (hazard ratio (HR)=1.64, 95% CI: 1.04-2.58, P=0.034). The risk allele of the variant at the chromosome 5p15 locus encompassing TERT-CLPTM1L (rs401681) was also associated with an earlier median onset of BCC, 31 years (95% CI: 28-37) compared with 41 years (95% CI: 32-48, HR=1.44, 95% CI: 1.08-1.93, P=0.014). In individuals with a risk allele at either rs1805007 or rs401681 the median time to BCC was 31 years of age (95% CI: 28-34) compared with 44 years of age (95% CI: 38-53) in wild-type individuals (HR=2.48, 95% CI: 1.47-4.17, P=0.0002). Our findings may have implications for future personalized risk estimates and BCC screening strategies in individuals with Gorlin syndrome.

Basal cell carcinomas in a tertiary referral centre: a systematic analysis.

PubMed

Dreier, J; Cheng, P F; Bogdan Alleman, I; Gugger, A; Hafner, J; Tschopp, A; Goldinger, S M; Levesque, M P; Dummer, R

2014-11-01

Basal cell carcinoma (BCC) is the most frequent skin cancer with increasing incidence and generally high cure rates. BCC can be quite aggressive and is difficult to treat. To investigate BCCs with a focus on histological subtypes, treatment procedures and correlation to clinical progress to collect further information on complex BCC cases. In this retrospective single-centre analysis the dermatopathology database, a network of cooperating dermatological surgeons, was queried for BCC cases between January 2007 and December 2011. Of 14,423 samples from a total of 9652 patients initially identified, 2938 patients were treated at the University Hospital Zurich and had corresponding local electronic patient records. Patients (n = 2938) (with 4769 diagnoses, 2006 re-excisions with 1180 microscopically controlled surgeries) were classified based on severity estimations into 2240 simple, 640 moderate, and 58 severe cases, including one BCC-treatment-associated death and 11 patients with subsequent participation in a clinical trial. In moderate and severe cases (n = 698), there were significantly higher rates of unique histological diagnoses (n = 2·5; P < 0·0001), higher association with basosquamous carcinoma [odds ratio (OR) 3·6; P < 0·0001] and sclerosing BCC (OR 2·48; P < 0·0001). Of the patients with basosquamous carcinoma 82·6% had a previous history of BCC. This is the first study that analyses the frequency of complicated BCCs in a tertiary referral centre. There were 6·6% moderate (640 of 9652) and 0·6% (58 of 9652) severe cases. We found significantly more varying histological diagnoses and significant association with aggressive subtypes in moderate and severe cases. These patients might especially benefit from new therapeutic options. © 2014 British Association of Dermatologists.

Regional variations of basal cell carcinoma incidence in the U.K. using The Health Improvement Network database (2004-10).

PubMed

Musah, A; Gibson, J E; Leonardi-Bee, J; Cave, M R; Ander, E L; Bath-Hextall, F

2013-11-01

Basal cell carcinoma (BCC) is one of the most common types of nonmelanoma skin cancer affecting the white population; however, little is known about how the incidence varies across the U.K. To determine the variation in BCC throughout the U.K. Data from 2004 to 2010 were obtained from The Health Improvement Network database. European and world age-standardized incidence rates (EASRs and WASRs, respectively) were obtained for country-level estimates and levels of socioeconomic deprivation, while strategic health-authority-level estimates were directly age and sex standardized to the U.K. standard population. Incidence-rate ratios were estimated using multivariable Poisson regression models. The overall EASR and WASR of BCC in the U.K. were 98.6 per 100,000 person-years and 66.9 per 100,000 person-years, respectively. Regional-level incidence rates indicated a significant geographical variation in the distribution of BCC, which was more pronounced in the southern parts of the country. The South East Coast had the highest BCC rate followed by South Central, Wales and the South West. Incidence rates were substantially higher in the least deprived groups and we observed a trend of decreasing incidence with increasing levels of deprivation (P < 0.001). Finally, in terms of age groups, the largest annual increase was observed among those aged 30-49 years. Basal cell carcinoma is an increasing health problem in the U.K.; the southern regions of the U.K. and those in the least deprived groups had a higher incidence of BCC. Our findings indicate an increased incidence of BCC for younger age groups below 49 years. © 2013 British Association of Dermatologists.

Silibinin and its 2,3-Dehydro-derivative Inhibit Basal Cell Carcinoma Growth via Suppression of Mitogenic Signaling and Transcription Factors Activation

PubMed Central

Tilley, Cynthia; Deep, Gagan; Agarwal, Chapla; Wempe, Michael F; Biedermann, David; Valentová, Kateřina; Kren, Vladimir; Agarwal, Rajesh

2014-01-01

Basal cell carcinoma (BCC) is the most common cancer worldwide, and its current treatment options are insufficient and toxic. Surprisingly, unlike several other malignancies, chemopreventive efforts against BCC are almost lacking. Silibinin, a natural agent from milk thistle seeds, has shown strong efficacy against several cancers including ultraviolet radiation-induced skin (squamous) cancer; however, its potential activity against BCC is not yet examined. Herein, for the first time, we report the efficacy of silibinin and its oxidation product 2,3-dehydrosilibinin (DHS) against BCC both in vitro and in vivo using ASZ (p53 mutated) and BSZ (p53 deleted) cell lines derived from murine BCC tumors. Both silibinin and DHS significantly inhibited cell growth and clonogenicity while inducing apoptosis in a dose- and time-dependent manner, with DHS showing higher activity at lower concentrations. Both agents also inhibited the mitogenic signaling by reducing EGFR, ERK1/2, Akt, and STAT3 phosphorylation and suppressed the activation of transcription factors NF-κB and AP-1. More importantly, in an ectopic allograft model, oral administration of silibinin and DHS (200 mg/kg body weight) strongly inhibited the ASZ tumor growth by 44 and 71% (p<0.05), respectively, and decreased the expression of proliferation biomarkers (PCNA and cyclin D1) as well as NF-κB p50 and c-Fos in the tumor tissues. Taken together, these results provide the first evidence for the efficacy and usefulness of silibinin and its derivative DHS against BCC, and suggest the need for additional studies with these agents in pre-clinical and clinical BCC chemoprevention and therapy models. PMID:25492239

Silibinin and its 2,3-dehydro-derivative inhibit basal cell carcinoma growth via suppression of mitogenic signaling and transcription factors activation.

PubMed

Tilley, Cynthia; Deep, Gagan; Agarwal, Chapla; Wempe, Michael F; Biedermann, David; Valentová, Kateřina; Kren, Vladimir; Agarwal, Rajesh

2016-01-01

Basal cell carcinoma (BCC) is the most common cancer worldwide, and its current treatment options are insufficient and toxic. Surprisingly, unlike several other malignancies, chemopreventive efforts against BCC are almost lacking. Silibinin, a natural agent from milk thistle seeds, has shown strong efficacy against several cancers including ultraviolet radiation-induced skin (squamous) cancer; however, its potential activity against BCC is not yet examined. Herein, for the first time, we report the efficacy of silibinin and its oxidation product 2,3-dehydrosilibinin (DHS) against BCC both in vitro and in vivo using ASZ (p53 mutated) and BSZ (p53 deleted) cell lines derived from murine BCC tumors. Both silibinin and DHS significantly inhibited cell growth and clonogenicity while inducing apoptosis in a dose- and time-dependent manner, with DHS showing higher activity at lower concentrations. Both agents also inhibited the mitogenic signaling by reducing EGFR, ERK1/2, Akt, and STAT3 phosphorylation and suppressed the activation of transcription factors NF-κB and AP-1. More importantly, in an ectopic allograft model, oral administration of silibinin and DHS (200 mg/kg body weight) strongly inhibited the ASZ tumor growth by 44% and 71% (P < 0.05), respectively, and decreased the expression of proliferation biomarkers (PCNA and cyclin D1) as well as NF-κB p50 and c-Fos in the tumor tissues. Taken together, these results provide the first evidence for the efficacy and usefulness of silibinin and its derivative DHS against BCC, and suggest the need for additional studies with these agents in pre-clinical and clinical BCC chemoprevention and therapy models. © 2014 Wiley Periodicals, Inc.

Height, height-related SNPs, and risk of non-melanoma skin cancer

PubMed Central

Li, Xin; Liang, Liming; Feng, Yen-Chen Anne; De Vivo, Immaculata; Giovannucci, Edward; Tang, Jean Y; Han, Jiali

2017-01-01

Background: Adult height has been associated with risk of several site-specific cancers, including melanoma. However, less attention has been given to non-melanoma skin cancer (NMSC). Methods: We prospectively examined the risk of squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) in relation to adult height in the Nurses' Health Study (NHS, n=117 863) and the Health Professionals Follow-up Study (HPFS, n=51 111). We also investigated the relationships between height-related genetic markers and risk of BCC and SCC in the genetic data sets of the NHS and HPFS (3898 BCC cases, and 8530 BCC controls; 527 SCC cases, and 8962 SCC controls). Results: After controlling for potential confounding factors, the hazard ratios were 1.09 (95% CI: 1.02, 1.15) and 1.10 (95% CI: 1.07, 1.13) for the associations between every 10 cm increase in height and risk of SCC and BCC respectively. None of the 687 height-related single-nucleotide polymorphisms (SNPs) was significantly associated with the risk of SCC or BCC, nor were the genetic scores combining independent height-related loci. Conclusions: Our data from two large cohorts provide further evidence that height is associated with an increased risk of NMSC. More studies on height-related genetic loci and early-life exposures may help clarify the underlying mechanisms. PMID:27846199

The incidence and body site of skin cancers in the population groups of South Africa.

PubMed

Norval, Mary; Kellett, Patricia; Wright, Caradee Yael

2014-10-01

Data regarding basal cell carcinoma (BCC), squamous cell carcinoma of the skin (SSCC) and cutaneous melanoma (CM) in multiracial populations are sparse. Here the incidence and body site of these tumours in the South African population in 2000-2004 were analysed. Annual age-standardized incidences and body sites of BCC, SSCC and CM in black, coloured, Asian and white groups were obtained from histological confirmed cases, reported to the National Cancer Registry. Highest annual incidences of BCC, SSCC and CM occurred in the white group, followed by coloured, then Asian and then black. BCCs and SSCCs were about twice as common in males than females. CM was the least frequent skin tumour, and BCC the most frequent, except in black people. The head was the commonest body site for SSCC and BCC in all groups and both sexes, whereas the lower limb was the predominant site for CM in black people. Mean age at diagnosis was generally mid-50s for CM, and mid-60s for BCC and SSCC. In South Africa, differences in reported incidence rates and body sites of skin tumours by population group and sex occur. Host characteristics, particularly skin phototype, and personal behaviour are likely to affect the risk of these cancers. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Preliminary data on antibacterial activity of Echinacea purpurea-associated bacterial communities against Burkholderia cepacia complex strains, opportunistic pathogens of Cystic Fibrosis patients.

PubMed

Chiellini, Carolina; Maida, Isabel; Maggini, Valentina; Bosi, Emanuele; Mocali, Stefano; Emiliani, Giovanni; Perrin, Elena; Firenzuoli, Fabio; Mengoni, Alessio; Fani, Renato

2017-03-01

Burkholderia cepacia complex bacteria (Bcc) represent a serious threat for immune-compromised patient affected by Cystic Fibrosis (CF) since they are resistant to many substances and to most antibiotics. For this reason, the research of new natural compounds able to inhibit the growth of Bcc strains has raised new interest during the last years. A source of such natural compounds is represented by medicinal plants and, in particular, by bacterial communities associated with these plants able to produce molecules with antimicrobial activity. In this work, a panel of 151 (endophytic) bacteria isolated from three different compartments (rhizospheric soil, roots, and stem/leaves) of the medicinal plant Echinacea purpurea were tested (using the cross-streak method) for their ability to inhibit the growth of 10 Bcc strains. Data obtained revealed that bacteria isolated from the roots of E. purpurea are the most active in the inhibition of Bcc strains, followed by bacteria isolated from the rhizospheric soil, and endophytes from stem/leaf compartment. At the same time, Bcc strains of environmental origin showed a higher resistance toward inhibition than the Bcc strains with clinical (i.e. CF patients) origin. Differences in the inhibition activity of E. purpurea-associated bacteria are mainly linked to the environment -the plant compartment- rather than to their taxonomical position. Copyright © 2016 Elsevier GmbH. All rights reserved.

Snowmelt-driven changes in dissolved organic matter and bacterioplankton communities in the Heilongjiang watershed of China.

PubMed

Qiu, Linlin; Cui, Hongyang; Wu, Junqiu; Wang, Baijie; Zhao, Yue; Li, Jiming; Jia, Liming; Wei, Zimin

2016-06-15

Bacterioplankton plays a significant role in the circulation of materials and ecosystem function in the biosphere. Dissolved organic matter (DOM) from dead plant material and surface soil leaches into water bodies when snow melts. In our study, water samples from nine sampling sites along the Heilongjiang watershed were collected in February and June 2014 during which period snowmelt occurred. The goal of this study was to characterize changes in DOM and bacterioplankton community composition (BCC) associated with snowmelt, the effects of DOM, environmental and geographical factors on the distribution of BCC and interactions of aquatic bacterioplankton populations with different sources of DOM in the Heilongjiang watershed. BCC was measured by denaturing gradient gel electrophoresis (DGGE). DOM was measured by excitation-emission matrix (EEM) fluorescence spectroscopy. Bacterioplankton exhibited a distinct seasonal change in community composition due to snowmelt at all sampling points except for EG. Redundancy analysis (RDA) indicated that BCC was more closely related to DOM (Components 1 and 4, dissolved organic carbon, biochemical oxygen demand and chlorophyll a) and environmental factors (water temperature and nitrate nitrogen) than geographical factors. Furthermore, DOM had a greater impact on BCC than environmental factors (29.80 vs. 15.90% of the variation). Overall, spring snowmelt played an important role in altering the quality and quantity of DOM and BCC in the Heilongjiang watershed. Copyright © 2016 Elsevier B.V. All rights reserved.

Nonlinear spectral imaging of human normal skin, basal cell carcinoma and squamous cell carcinoma based on two-photon excited fluorescence and second-harmonic generation

NASA Astrophysics Data System (ADS)

Xiong, S. Y.; Yang, J. G.; Zhuang, J.

2011-10-01

In this work, we use nonlinear spectral imaging based on two-photon excited fluorescence (TPEF) and second harmonic generation (SHG) for analyzing the morphology of collagen and elastin and their biochemical variations in basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and normal skin tissue. It was found in this work that there existed apparent differences among BCC, SCC and normal skin in terms of their thickness of the keratin and epithelial layers, their size of elastic fibers, as well as their distribution and spectral characteristics of collagen. These differences can potentially be used to distinguish BCC and SCC from normal skin, and to discriminate between BCC and SCC, as well as to evaluate treatment responses.

Effect of Cold Deformation and Annealing on the Microstructure and Tensile Properties of a HfNbTaTiZr Refractory High Entropy Alloy

NASA Astrophysics Data System (ADS)

Senkov, O. N.; Pilchak, A. L.; Semiatin, S. L.

2018-07-01

The microstructure and tensile properties of HfNbTaTiZr after cold working and annealing were investigated. Cold work was introduced by axial compression followed by rolling resulting in a total thickness reduction of 89 pct without any evidence of cracking. The cold-worked material retained a single-phase microstructure and had a room temperature tensile yield stress σ 0.2 = 1438 MPa, peak true stress σ p = 1495 MPa, and true fracture strain ɛ f = 5 pct. Annealing at 800 °C for up to 256 hours resulted in the precipitation of Nb and Ta rich particles with a BCC crystal structure inside a Hf-and-Zr-enriched BCC matrix. The second phase particles nucleated heterogeneously inside deformation bands and slip lines and coarsened during annealing. Analysis of the coarsening behavior suggested that kinetics were controlled by the diffusion of Nb and Ta. In the two-phase material, σ 0.2 and σ p decreased from 1159 to 1071 MPa and from 1174 to 1074 MPa, respectively, with an increase in particle diameter from 0.18 to 0.72 μm, while ɛ f remained between 5 and 8 pct. Full recrystallization and normal grain growth, with the activation energy of 238 kJ/mol and activation volume of 5.3 to 9.6 m3/mol, occurred during annealing above 1000 °C. After heat treatment at this temperature, the alloy was characterized by a single-phase BCC structure with σ 0.2 = 1110 to 1115 MPa, σ p = 1160 to 1195 MPa, and ɛ f = 12 to 19 pct with the maximum values attained after annealing for 1 hour.

Effect of Cold Deformation and Annealing on the Microstructure and Tensile Properties of a HfNbTaTiZr Refractory High Entropy Alloy

NASA Astrophysics Data System (ADS)

Senkov, O. N.; Pilchak, A. L.; Semiatin, S. L.

2018-05-01

The microstructure and tensile properties of HfNbTaTiZr after cold working and annealing were investigated. Cold work was introduced by axial compression followed by rolling resulting in a total thickness reduction of 89 pct without any evidence of cracking. The cold-worked material retained a single-phase microstructure and had a room temperature tensile yield stress σ 0.2 = 1438 MPa, peak true stress σ p = 1495 MPa, and true fracture strain ɛ f = 5 pct. Annealing at 800 °C for up to 256 hours resulted in the precipitation of Nb and Ta rich particles with a BCC crystal structure inside a Hf-and-Zr-enriched BCC matrix. The second phase particles nucleated heterogeneously inside deformation bands and slip lines and coarsened during annealing. Analysis of the coarsening behavior suggested that kinetics were controlled by the diffusion of Nb and Ta. In the two-phase material, σ 0.2 and σ p decreased from 1159 to 1071 MPa and from 1174 to 1074 MPa, respectively, with an increase in particle diameter from 0.18 to 0.72 μm, while ɛ f remained between 5 and 8 pct. Full recrystallization and normal grain growth, with the activation energy of 238 kJ/mol and activation volume of 5.3 to 9.6 m3/mol, occurred during annealing above 1000 °C. After heat treatment at this temperature, the alloy was characterized by a single-phase BCC structure with σ 0.2 = 1110 to 1115 MPa, σ p = 1160 to 1195 MPa, and ɛ f = 12 to 19 pct with the maximum values attained after annealing for 1 hour.

Treatment of Basal Cell Carcinoma Using a One-Stop-Shop With Reflectance Confocal Microscopy: Study Design and Protocol of a Randomized Controlled Multicenter Trial.

PubMed

Kadouch, Daniel J; Wolkerstorfer, Albert; Elshot, Yannick; Zupan-Kajcovski, Biljana; Crijns, Marianne B; Starink, Markus V; Bekkenk, Marcel W; van der Wal, Allard C; Spuls, Phyllis I; de Rie, Menno A

2015-09-10

Basal cell carcinoma (BCC) is the most common cancer diagnosed in white populations worldwide. The rising incidence of BCC is becoming a major worldwide public health problem. Therefore, there is a need for more efficient management. The aim of this research is to assess the efficacy and safety of a one-stop-shop (OSS) concept, using real-time in vivo reflectance confocal microscopy (RCM) (Vivascope 1500; Lucid Technologies, Henrietta, NY, USA) as a diagnostic tool, prior to surgical management of new primary BCCs. This is a prospective non-inferiority multi-center RCT designed to compare the "OSS concept using RCM" to current standards of care in diagnosing and treating clinically suspected BCC. Patients ≥ 18 years attending our outpatient clinic at the Department of Dermatology, Academic Medical Center, University of Amsterdam, and the Department of Dermatology, the Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital (Amsterdam, The Netherlands) with a clinically suspected new primary BCC lesion will be considered for enrollment using predefined inclusion and exclusion criteria, and will be randomly allocated to the experimental or control group. The main outcome parameter is the assessment of incomplete surgical excision margins on the final pathology report of confirmed BCC lesions (either by punch biopsy or RCM imaging). Other outcome measures include diagnostic accuracy (sensitivity and specificity) of RCM for diagnosing BCC and dividing between subtypes, and throughput time. Patient satisfaction data will be collected postoperatively after 3 months during routine follow-up. This research is investigator-initiated and received ethics approval. Patient recruitment started in February 2015, and we expect all study-related activities to be completed by fall 2015. This RCT is the first to examine an OSS concept using RCM for diagnosing and treating clinically suspected BCC lesions. Results of this research are expected to have applications in evidence-based practice for the increasing number of patients suffering from BCC and possibly lead to a more efficient disease management strategy. ClinicalTrials.gov: NCT02285790; https://clinicaltrial.gov/ct2/show/NCT02285790 (Archived by WebCite at http://www.webcitation.org/6b2LfDKWu).

Behavior change communication activities improve infant and young child nutrition knowledge and practice of neighboring non-participants in a cluster-randomized trial in rural Bangladesh.

PubMed

Hoddinott, John; Ahmed, Ishita; Ahmed, Akhter; Roy, Shalini

2017-01-01

To examine the impact on infant and young child nutrition knowledge and practice of mothers who were neighbors of mothers participating in a nutrition Behavior Change Communication (BCC) intervention in rural Bangladesh. We analyzed data from 300 mothers whose neighbor participated in a nutrition BCC intervention and 600 mothers whose neighbor participated in an intervention that did not include BCC. We constructed measures capturing mothers' knowledge of infant and young child nutrition (IYCN) and measures of food consumption by children 6-24m. The effect on these outcomes of exposure to a neighbor receiving a nutrition BCC intervention was estimated using ordinary least squares and probit regressions. The study was registered with ClinicalTrials.gov (Study ID: NCT02237144). Having a neighboring mother participate in a nutrition BCC intervention increased non-participant mothers' IYCN knowledge by 0.17 SD (translating to 0.3 more correct answers). They were 14.1 percentage points more likely to feed their 6-24m children legumes and nuts; 11.6 percentage points more likely to feed these children vitamin A rich fruits and vegetables; and 10.0 percentage points more likely to feed these children eggs. Children of non-participant mothers who had a neighboring mother participate in a nutrition BCC intervention were 13.8 percentage points more likely to meet World Health Organization (WHO) guidelines for minimum diet diversity, 11.9 percentage points more likely to meet WHO guidelines for minimum acceptable diet, and 10.3 percentage points more likely to meet WHO guidelines for minimum meal frequency for children who continue to be breastfed after age 6m. Children aged 0-6m of non-participant mothers who are neighbors of mothers receiving BCC were 7.1 percentage points less likely to have ever consumed water-based liquids. Studies of nutrition BCC that do not account for information spillovers to non-participants may underestimate its benefits in terms of IYCN knowledge and practice.

Behavior change communication activities improve infant and young child nutrition knowledge and practice of neighboring non-participants in a cluster-randomized trial in rural Bangladesh

PubMed Central

Ahmed, Ishita; Ahmed, Akhter; Roy, Shalini

2017-01-01

Objective To examine the impact on infant and young child nutrition knowledge and practice of mothers who were neighbors of mothers participating in a nutrition Behavior Change Communication (BCC) intervention in rural Bangladesh. Methods We analyzed data from 300 mothers whose neighbor participated in a nutrition BCC intervention and 600 mothers whose neighbor participated in an intervention that did not include BCC. We constructed measures capturing mothers’ knowledge of infant and young child nutrition (IYCN) and measures of food consumption by children 6-24m. The effect on these outcomes of exposure to a neighbor receiving a nutrition BCC intervention was estimated using ordinary least squares and probit regressions. The study was registered with ClinicalTrials.gov (Study ID: NCT02237144). Results Having a neighboring mother participate in a nutrition BCC intervention increased non-participant mothers’ IYCN knowledge by 0.17 SD (translating to 0.3 more correct answers). They were 14.1 percentage points more likely to feed their 6-24m children legumes and nuts; 11.6 percentage points more likely to feed these children vitamin A rich fruits and vegetables; and 10.0 percentage points more likely to feed these children eggs. Children of non-participant mothers who had a neighboring mother participate in a nutrition BCC intervention were 13.8 percentage points more likely to meet World Health Organization (WHO) guidelines for minimum diet diversity, 11.9 percentage points more likely to meet WHO guidelines for minimum acceptable diet, and 10.3 percentage points more likely to meet WHO guidelines for minimum meal frequency for children who continue to be breastfed after age 6m. Children aged 0-6m of non-participant mothers who are neighbors of mothers receiving BCC were 7.1 percentage points less likely to have ever consumed water-based liquids. Conclusions Studies of nutrition BCC that do not account for information spillovers to non-participants may underestimate its benefits in terms of IYCN knowledge and practice. PMID:28636674

Prediction of Austenite Formation Temperatures Using Artificial Neural Networks

NASA Astrophysics Data System (ADS)

Schulze, P.; Schmidl, E.; Grund, T.; Lampke, T.

2016-03-01

For the modeling and design of heat treatments, in consideration of the development/ transformation of the microstructure, different material data depending on the chemical composition, the respective microstructure/phases and the temperature are necessary. Material data are, e.g. the thermal conductivity, heat capacity, thermal expansion and transformation data etc. The quality of thermal simulations strongly depends on the accuracy of the material data. For many materials, the required data - in particular for different microstructures and temperatures - are rare in the literature. In addition, a different chemical composition within the permitted limits of the considered steel alloy cannot be predicted. A solution for this problem is provided by the calculation of material data using Artificial Neural Networks (ANN). In the present study, the start and finish temperatures of the transformation from the bcc lattice to the fcc lattice structure of hypoeutectoid steels are calculated using an Artificial Neural Network. An appropriate database containing different transformation temperatures (austenite formation temperatures) to train the ANN is selected from the literature. In order to find a suitable feedforward network, the network topologies as well as the activation functions of the hidden layers are varied and subsequently evaluated in terms of the prediction accuracy. The transformation temperatures calculated by the ANN exhibit a very good compliance compared to the experimental data. The results show that the prediction performance is even higher compared to classical empirical equations such as Andrews or Brandis. Therefore, it can be assumed that the presented ANN is a convenient tool to distinguish between bcc and fcc phases in hypoeutectoid steels.

Review of high pressure phases of calcium by first-principles calculations

NASA Astrophysics Data System (ADS)

Ishikawa, T.; Nagara, H.; Suzuki, N.; Tsuchiya, J.; Tsuchiya, T.

2010-03-01

We review high pressure phases of calcium which have obtained by recent experimental and first-principles studies. In this study, we investigated the face-centered cubic (fcc) structure, the body-centered cubic (bcc) structure, the simple cubic (sc) structure, a tetragonal P43212 [Ishikawa T et al. 2008 Phys. Rev. B 77 020101(R)], an orthorhombic Cmca [Ishikawa T et al. 2008 Phys. Rev. B 77 020101(R)], an orthorhombic Cmcm [Teweldeberhan A M and Bonev S A 2008 Phys. Rev. B 78 140101(R)], an orthorhombic Pnma [Yao Y et al. 2008 Phys. Rev. B 78 054506] and a tetragonal I4/mcm(00) [Arapan S et al. 2008 Proc. Natl. Acad. Sci. USA 105 20627]. We compared the enthalpies among the structures up to 200 GPa and theoretically determined the phase diagram of calcium. The sequence of the structural transitions is fcc (0- 3.5 GPa) → bcc (3.5 - 35.7 GPa) → Cmcm (35.7- 52GPa) → P43212 (52-109 GPa) → Cmca (109-117.4GPa) → Pnma (117.4-134.6GPa) → I4/mcm(00) (134.6 GPa -). The sc phase is experimentally observed in the pressure range from 32 to 113 GPa but, in our calculation, there is no pressure region where the sc phase is the most stable. In addition, we found that the enthalpy of the hexagonal close-packed (hcp) structure is lower than that of I4/mcm(00) above 495 GPa.

Lattice dynamics and elasticity for ε-plutonium [First-principles lattice dynamics for ε-plutonium

DOE PAGES

Söderlind, Per

2017-04-25

Here, lattice dynamics and elasticity for the high-temperature ε phase (body-centered cubic; bcc) of plutonium is predicted utilizing first-principles electronic structure coupled with a self-consistent phonon method that takes phonon-phonon interaction and strong anharmonicity into account. These predictions establish the first sensible lattice-dynamics and elasticity data on ε-Pu. The atomic forces required for the phonon scheme are highly accurate and derived from the total energies obtained from relativistic and parameter-free density-functional theory. The results appear reasonable but no data exist to compare with except those from dynamical mean-field theory that suggest ε-plutonium is mechanically unstable. Fundamental knowledge and understanding ofmore » the high-temperature bcc phase, that is generally present in all actinide metals before melting, is critically important for a proper interpretation of the phase diagram as well as practical modeling of high-temperature properties.« less

Peierls potential of screw dislocations in bcc transition metals: Predictions from density functional theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weinberger, Christopher R.; Tucker, Garritt J.; Foiles, Stephen M.

2013-02-01

It is well known that screw dislocation motion dominates the plastic deformation in body-centered-cubic metals at low temperatures. The nature of the nonplanar structure of screw dislocations gives rise to high lattice friction, which results in strong temperature and strain rate dependence of plastic flow. Thus the nature of the Peierls potential, which is responsible for the high lattice resistance, is an important physical property of the material. However, current empirical potentials give a complicated picture of the Peierls potential. Here, we investigate the nature of the Peierls potential using density functional theory in the bcc transition metals. The resultsmore » show that the shape of the Peierls potential is sinusoidal for every material investigated. Furthermore, we show that the magnitude of the potential scales strongly with the energy per unit length of the screw dislocation in the material.« less

Novel Hedgehog pathway targets against basal cell carcinoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, Jean Y.; Department of Epidemiology and Biostatistics, University of California, San Francisco, CA; So, P.-L.

2007-11-01

The Hedgehog signaling pathway plays a key role in directing growth and patterning during embryonic development and is required in vertebrates for the normal development of many structures, including the neural tube, axial skeleton, skin, and hair. Aberrant activation of the Hedgehog (Hh) pathway in adult tissue is associated with the development of basal cell carcinoma (BCC), medulloblastoma, and a subset of pancreatic, gastrointestinal, and other cancers. This review will provide an overview of what is known about the mechanisms by which activation of Hedgehog signaling leads to the development of BCCs and will review two recent papers suggesting thatmore » agents that modulate sterol levels might influence the Hh pathway. Thus, sterols may be a new therapeutic target for the treatment of BCCs, and readily available agents such as statins (HMG-CoA reductase inhibitors) or vitamin D might be helpful in reducing BCC incidence.« less

A review of the irradiation evolution of dispersed oxide nanoparticles in the b.c.c. Fe-Cr system: Current understanding and future directions

NASA Astrophysics Data System (ADS)

Wharry, Janelle P.; Swenson, Matthew J.; Yano, Kayla H.

2017-04-01

Thus far, a number of studies have investigated the irradiation evolution of oxide nanoparticles in b.c.c. Fe-Cr based oxide dispersion strengthened (ODS) alloys. But given the inconsistent experimental conditions, results have been widely variable and inconclusive. Crystal structure and chemistry changes differ from experiment to experiment, and the total nanoparticle volume fraction has been observed to both increase and decrease. Furthermore, there has not yet been a comprehensive review of the archival literature. In this paper, we summarize the existing studies on nanoparticle irradiation evolution. We note significant observations with respect to oxide nanoparticle crystallinity, composition, size, and number density. We discuss four possible contributing mechanisms for nanoparticle evolution: ballistic dissolution, Ostwald ripening, irradiation-enhanced diffusion, and homogeneous nucleation. Finally, we propose future directions to achieve a more comprehensive understanding of irradiation effects on oxide nanoparticles in ODS alloys.

Carbon in iron phases under high pressure

NASA Astrophysics Data System (ADS)

Huang, L.; Skorodumova, N. V.; Belonoshko, A. B.; Johansson, B.; Ahuja, R.

2005-11-01

The influence of carbon impurities on the properties of iron phases (bcc, hcp, dhcp, fcc) has been studied using the first-principles projector augmented-wave (PAW) method for a wide pressure range. It is shown that the presence of ~6 at. % of interstitial carbon has a little effect on the calculated structural sequence of the iron phases under high pressure. The bcc -> hcp transition both for pure iron and iron containing carbon takes place around 9 GPa. According to the enthalpies comparison, the solubility of carbon into the iron solid is decreased by high pressure. The coexistence of iron carbide (Fe3C) + pure hcp Fe is most stable phase at high pressure compared with other phases. Based on the analysis of the pressure-density dependences for Fe3C and hcp Fe, we suggest that there might be some fraction of iron carbide present in the core.

Neuroendocrine differentiation in basal cell carcinoma.

PubMed

Houcine, Yoldez; Chelly, Ines; Zehani, Alia; Belhaj Kacem, Linda; Azzouz, Haifa; Rekik, Wafa; C, Hend; Haouet, Slim; Kchir, Nidhameddine

2017-01-01

Basal cell carcinoma (BCC) is the prototypical basaloid tumor of the skin. It may show various patterns simulating other cutaneous tumors due to its pleomorphism. It may have an unusal pattern of differentiation such as squamous, sebaceous, apocrine, eccrine, pilar, and endocrine differentiation. In order to establish the relative frequency of neuroendocrine differentiation in BCC, we performed a retrospective study of 33 consecutive BCCs using conventional immunohistochemistry with two neuroendocrine antibodies: Chromogranine A and synaptophysine. The age of the patients ranged from 17-83 years with mean of 65 years. The male to female ratio was 16:17. In immunohistochimestry, Chromogranine A was seen in 72.2% (24/33) while Synaptophysine was positive in 9.09% (3/33). Their expression was cytoplasmic and membranous and was seen in the periphery of these tumors in the overlying cells. Positive staining of chromogranine A was high (75-100% of tumors cells) in 9%, intermediate (25-75% of tumors cells) in 33% of cases and relatively low (<25%) in 30.3% of cases.

Strategic roles for behaviour change communication in a changing malaria landscape.

PubMed

Koenker, Hannah; Keating, Joseph; Alilio, Martin; Acosta, Angela; Lynch, Matthew; Nafo-Traore, Fatoumata

2014-01-02

Strong evidence suggests that quality strategic behaviour change communication (BCC) can improve malaria prevention and treatment behaviours. As progress is made towards malaria elimination, BCC becomes an even more important tool. BCC can be used 1) to reach populations who remain at risk as transmission dynamics change (e.g. mobile populations), 2) to facilitate identification of people with asymptomatic infections and their compliance with treatment, 3) to inform communities of the optimal timing of malaria control interventions, and 4) to explain changing diagnostic concerns (e.g. increasing false negatives as parasite density and multiplicity of infections fall) and treatment guidelines. The purpose of this commentary is to highlight the benefits and value for money that BCC brings to all aspects of malaria control, and to discuss areas of operations research needed as transmission dynamics change.

Strategic roles for behaviour change communication in a changing malaria landscape

PubMed Central

2014-01-01

Strong evidence suggests that quality strategic behaviour change communication (BCC) can improve malaria prevention and treatment behaviours. As progress is made towards malaria elimination, BCC becomes an even more important tool. BCC can be used 1) to reach populations who remain at risk as transmission dynamics change (e.g. mobile populations), 2) to facilitate identification of people with asymptomatic infections and their compliance with treatment, 3) to inform communities of the optimal timing of malaria control interventions, and 4) to explain changing diagnostic concerns (e.g. increasing false negatives as parasite density and multiplicity of infections fall) and treatment guidelines. The purpose of this commentary is to highlight the benefits and value for money that BCC brings to all aspects of malaria control, and to discuss areas of operations research needed as transmission dynamics change. PMID:24383426

Application of STEM characterization for investigating radiation effects in BCC Fe-based alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parish, Chad M.; Field, Kevin G.; Certain, Alicia G.

2015-04-20

This paper provides a general overview of advanced scanning transmission electron microscopy (STEM) techniques used for characterization of irradiated BCC Fe-based alloys. Advanced STEM methods provide the high-resolution imaging and chemical analysis necessary to understand the irradiation response of BCC Fe-based alloys. The use of STEM with energy dispersive x-ray spectroscopy (EDX) for measurement of radiation-induced segregation (RIS) is described, with an illustrated example of RIS in proton- and self-ion irradiated T91. Aberration-corrected STEM-EDX for nanocluster/nanoparticle imaging and chemical analysis is also discussed, and examples are provided from ion-irradiated oxide dispersion strengthened (ODS) alloys. In conclusion, STEM techniques for void,more » cavity, and dislocation loop imaging are described, with examples from various BCC Fe-based alloys.« less

Pseudoalteromonas haloplanktis produces methylamine, a volatile compound active against Burkholderia cepacia complex strains.

PubMed

Sannino, Filomena; Parrilli, Ermenegilda; Apuzzo, Gennaro Antonio; de Pascale, Donatella; Tedesco, Pietro; Maida, Isabel; Perrin, Elena; Fondi, Marco; Fani, Renato; Marino, Gennaro; Tutino, Maria Luisa

2017-03-25

The Antarctic marine bacterium Pseudoalteromonas haloplanktis TAC125 has been reported to produce several Volatile Organic Compounds (VOCs), which are able to inhibit the growth of Burkholderia cepacia complex (Bcc) strains, opportunistic pathogens responsible for the infection of immune-compromised patients. However, no specific antibacterial VOCs have been identified to date. The purpose of the present study was to identify specific VOCs that contribute to Bcc inhibition by the Antarctic strain. When grown on defined medium containing D-gluconate and L-glutamate as carbon, nitrogen and energy sources, P. haloplanktis TAC125 is unable to inhibit the growth of Bcc strains. However, single addition of several amino acids to the defined medium restores the P. haloplanktis TAC125 inhibition ability. With the aim of identifying specific volatile compound/s responsible for Bcc inhibition, we set up an apparatus for VOC capture, accumulation, and storage. P. haloplanktis TAC125 was grown in an automatic fermenter which was connected to a cooling system to condense VOCs present in the exhaust air outlet. Upon addition of methionine to the growth medium, the VOC methylamine was produced by P. haloplanktis TAC125. Methylamine was found to inhibit the growth of several Bcc strains in a dose-dependent way. Although it was reported that P. haloplanktis TAC125 produces VOCs endowed with antimicrobial activity, this is the first demonstration that methylamine probably contributes to the anti-Bcc activity of P. haloplanktis TAC125 VOCs. Copyright © 2016 Elsevier B.V. All rights reserved.

High-Pressure Phase Transition of Iron: A Combined Magnetic Remanence and Mössbauer Study

NASA Astrophysics Data System (ADS)

Wei, Qingguo; McCammon, Catherine; Gilder, Stuart Alan

2017-12-01

We measured Mössbauer spectra and the acquisition of saturation isothermal remanent magnetization in alternating steps on the same sample of polycrystalline, multidiron metal powder in a diamond anvil cell across the body centered cubic (bcc) to hexagonal closed packed (hcp) phase transition at room temperature up to 19.2 GPa. Within the bcc stability field indicated by the presence of magnetic hyperfine splitting, saturation remanent magnetization and sextet area were well correlated during compression and decompression. The areas and dips of the outer (first and sixth) and middle (second and fifth) components of the sextet changed in relative proportion as a function of pressure, which was attributed to rotation of the magnetization direction perpendicular to the gamma-ray source. Sextet peaks disappeared above ˜15 GPa, yet magnetic remanence persisted. Magnetic remanence intensity divided by the fractional area of the sextet, taken to represent bcc Fe, attained maxima at pressures near the boundaries of the hysteretic transition, which we attribute to strain-related magnetostriction effects associated with a distorted bcc-hcp phase. Magnetic remanence observed within the hcp stability field, as defined by the absence of sextet peaks, could be due to a previously described, distorted bcc-hcp phase whose hyperfine field was below detection limits of Mössbauer spectroscopy. Our study suggests that distorted bcc-hcp Fe holds magnetic remanence and leaves open the possibility that this phase carries magnetic remanence into the pressure range where only pure hcp Fe is considered stable.

Efficacy of Photodynamic Therapy in the Short and Medium Term in the Treatment of Actinic Keratosis, Basal Cell Carcinoma, Acne Vulgaris and Photoaging: Results from Four Clinical Trials

PubMed Central

Martínez-Carpio, PA; Alcolea-López, JM; Vélez, M

2012-01-01

Objective: To determine the clinical efficacy of methyl-aminolevulinate (MAL)-Photodynamic Therapy (PDT) in the treatment of actinic keratosis (AK), basal cell carcinoma (BCC), acne vulgaris (AV) and photoaging (PA), in the short and medium term. Subjects and methods: Four separate prospective studies were designed on patients with AK (n=25), BCC (n=20), AV (n=20) and PA (n=25). Two PDT protocols were applied, and different clinical efficacy criteria were established, including lesion count and size. Two semi-quantitative and four analogue visual scales were completed for the evaluation of results according to the therapist, the patient and two independent experts. Results: In the AK and BCC studies, full clinical remission was observed in 84.7% and 75.7% of lesions, respectively. In the AV study, the number of inflammatory and non-inflammatory lesions fell significantly (p<0.001, p<0.05). In the PA study a reduction in Dover scale scores (3.19 vs. 2.14, p<0.001) was proven. The percentages of satisfied or very satisfied patients were: AK=88%, BCC=90%, AV=89% and PA=80%. A year later, none of the AK or BCC lesions had reappeared, and the cases of AV and PA remained stable, with a tendency towards improvement. Conclusion: the MAL-PDT procedures used produced efficacious, safe and satisfactory results in KA, BCC, AV and PA in the short and medium term. PMID:24511190

Clinical and pathologic parameters predicting recurrence of facial basal cell carcinoma: a retrospective audit in an advanced care center.

PubMed

Troeltzsch, Matthias; Probst, Florian A; Knösel, Thomas; Mast, Gerson; Ehrenfeld, Michael; Otto, Sven

2016-11-01

This study was designed to investigate the associations between clinical, pathologic, and therapeutic parameters of facial basal cell carcinoma (BCC) and recurrence rates in patients treated at an advanced care center. A retrospective cohort study was performed. Patients who presented to an advanced care center within a 6-year period with facial BCC and who received surgical treatment were included for further review according to predefined inclusion criteria. The predictor variable was defined as "negative-margin (R0) resection after the first surgery". The primary outcome variable was defined as "BCC recurrence". Descriptive and inferential statistics were computed. The significance level was set at P ≤ 0.05. A total of 71 patients (29 female, 42 male; average age: 71.76 years) were found to meet all of the study inclusion criteria. All BCCs had been referred, and 50.7% had been submitted to previous surgery. The mean ± standard deviation tumor diameter was 2.3 ± 1.8 cm. Recurrence of BCC was observed in 11 patients (15.5%). Large tumor diameters, increased patient age, and failure to achieve R0 resection at the first surgical appointment significantly increased recurrence rates. Complete facial BCC excision at the first surgical appointment is pivotal in reducing the likelihood of recurrence. The influence of the anatomic location of facial BCC on recurrence rates may be limited. © 2016 The International Society of Dermatology.

Elastic fields, dipole tensors, and interaction between self-interstitial atom defects in bcc transition metals

NASA Astrophysics Data System (ADS)

Dudarev, S. L.; Ma, Pui-Wai

2018-03-01

Density functional theory (DFT) calculations show that self-interstitial atom (SIA) defects in nonmagnetic body-centered-cubic (bcc) metals adopt strongly anisotropic configurations, elongated in the <111 > direction [S. Han et al., Phys. Rev. B 66, 220101 (2002), 10.1103/PhysRevB.66.220101; D. Nguyen-Manh et al., Phys. Rev. B 73, 020101 (2006), 10.1103/PhysRevB.73.020101; P. M. Derlet et al., Phys. Rev. B 76, 054107 (2007), 10.1103/PhysRevB.76.054107; S. L. Dudarev, Annu. Rev. Mater. Res. 43, 35 (2013), 10.1146/annurev-matsci-071312-121626]. Elastic distortions, associated with such anisotropic atomic structures, appear similar to distortions around small prismatic dislocation loops, although the extent of this similarity has never been quantified. We derive analytical formulas for the dipole tensors of SIA defects, which show that, in addition to the prismatic dislocation looplike character, the elastic field of a SIA defect also has a significant isotropic dilatation component. Using empirical potentials and DFT calculations, we parametrize dipole tensors of <111 > defects for all the nonmagnetic bcc transition metals. This enables a quantitative evaluation of the energy of elastic interaction between the defects, which also shows that in a periodic three-dimensional simple cubic arrangement of crowdions, long-range elastic interactions between a defect and all its images favor a <111 > orientation of the defect.

Diagnostic potential of optical coherence tomography in non-melanoma skin cancer: a clinical study

NASA Astrophysics Data System (ADS)

Mogensen, Mette; Thrane, Lars; Jørgensen, Thomas Martini; Jemec, Gregor B. E.

2007-07-01

Introduction: Non-melanoma skin cancer (NMSC) is the most prevalent cancer in the Western World. OCT has proved potential in assisting clinical diagnosis and perhaps reducing the need for biopsies in NMSC. As non-invasive treatment is increasingly used for NMSC patients with superficial lesions, the development of non-invasive diagnostic technologies is highly relevant. Methods: The aim of this cross-sectional clinical study, enrolling 100 NMSC patients and 20 healthy volunteers, is to investigate the diagnostic accuracy and applicability of OCT in NMSC diagnosis. Our OCT-system has been developed at Risoe National Laboratory, Denmark and offers ppolarization sensitive-OCT (PS-OCT) that may have additional advantaged as NMSC differ in content of birefringent collagens from normal skin. Results: Basal cell carcinomas (BCC) can in some cases be distinguished from normal skin in OCT-images, as normal skin exhibits a layered structure this layering is not present in BCC and sometimes not in actinic keratosis (AK). BCC lesions seem to be clearly less reflective than normal tissue. The predictive value of OCT in NMSC will be presented from a clinical point of view. Discussion: The earlier a skin cancer is diagnosed, the better the prognosis. Estimation of diagnostic accuracy and abilities of OCT in clinical studies of skin cancer patients is essential to establish the role and future set-ups for diagnostic OCT-systems.

Evaluation of intensified behaviour change communication strategies in an artemisinin resistance setting.

PubMed

Canavati, Sara E; de Beyl, Celine Zegers; Ly, Po; Shafique, Muhammad; Boukheng, Thavrin; Rang, Chandary; Whittaker, Maxine Anne; Roca-Feltrer, Arantxa; Sintasath, David

2016-04-30

In Cambodia, behaviour change communication (BCC) represents an integral component of malaria efforts aimed at fighting artemisinin resistant parasites and achieving elimination. The multi-pronged BCC interventions include interpersonal communication through village health volunteers (VHVs) and village malaria workers (VMWs), broadcasting malaria prevention, diagnosis and treatment messages via TV, radio and mobile broadcasting units (MBUs), distributing information education and communication (IEC) materials and introducing mobile malaria workers (MMWs) in endemic villages. This was a cross sectional household survey using a stratified multi-stage cluster sampling approach, conducted in December 2012. A stratified multi-stage cluster sampling approach was used; 30 villages were selected (15 in each stratum) and a total of 774 households were interviewed. This survey aimed to assess the potential added effect of 'intense' BCC interventions in three Western provinces. Conducted 2 years after start of these efforts, 'non-intense' BCC (niBBC) interventions (e.g., radio or TV) were compared to "intense" BCC (iBBC) implemented through a set of interpersonal communication strategies such as VMWs, VHVs, mobile broadcasting units and listener viewer clubs. In both groups, the knowledge of the mode of malaria transmission was high (96.9 vs 97.2 %; p = 0.83), as well as of fever as a symptom (91.5 vs 93.5 %; p = 0.38). Knowledge of local risk factors, such as staying in the forest (39.7 vs 30.7 %; p = 0.17) or the farm (7.1 vs 5.1 %; p = 0.40) was low in both groups. Few respondents in either group knew that they must get tested if they suspected malaria (0.3 vs 0.1; p = 0.69). However, iBBC increased the discussions about malaria in the family (51.7 vs 35.8 %; p = 0.002) and reported prompt access to treatment in case of fever (77.1 vs 59.4 %; p < 0.01). The use of iBCC supported positive improvements in both attitudes and behaviours among the population with regard to malaria compared to mass media (niBCC) only. The significantly increase in people seeking treatment for fever in iBCC villages supports Objective Five of the Strategic Plan in the Cambodia Malaria Elimination Action Framework (2016-2020). Therefore, this study provides evidence for the planning and implementation of future BCC interventions to achieve the elimination of artemisinin resistant Plasmodium falciparum malaria.

Seasonal Variations and Resilience of Bacterial Communities in a Sewage Polluted Urban River

PubMed Central

Ouattara, Nouho Koffi; Anzil, Adriana; Verbanck, Michel A.; Brion, Natacha; Servais, Pierre

2014-01-01

The Zenne River in Brussels (Belgium) and effluents of the two wastewater treatment plants (WWTPs) of Brussels were chosen to assess the impact of disturbance on bacterial community composition (BCC) of an urban river. Organic matters, nutrients load and oxygen concentration fluctuated highly along the river and over time because of WWTPs discharge. Tag pyrosequencing of bacterial 16S rRNA genes revealed the significant effect of seasonality on the richness, the bacterial diversity (Shannon index) and BCC. The major grouping: -winter/fall samples versus spring/summer samples- could be associated with fluctuations of in situ bacterial activities (dissolved and particulate organic carbon biodegradation associated with oxygen consumption and N transformation). BCC of the samples collected upstream from the WWTPs discharge were significantly different from BCC of downstream samples and WWTPs effluents, while no significant difference was found between BCC of WWTPs effluents and the downstream samples as revealed by ANOSIM. Analysis per season showed that allochthonous bacteria brought by WWTPs effluents triggered the changes in community composition, eventually followed by rapid post-disturbance return to the original composition as observed in April (resilience), whereas community composition remained altered after the perturbation by WWTPs effluents in the other seasons. PMID:24667680

An efficient system for the generation of marked genetic mutants in members of the genus Burkholderia.

PubMed

Shastri, Sravanthi; Spiewak, Helena L; Sofoluwe, Aderonke; Eidsvaag, Vigdis A; Asghar, Atif H; Pereira, Tyrone; Bull, Edward H; Butt, Aaron T; Thomas, Mark S

2017-01-01

To elucidate the function of a gene in bacteria it is vital that targeted gene inactivation (allelic replacement) can be achieved. Allelic replacement is often carried out by disruption of the gene of interest by insertion of an antibiotic-resistance marker followed by subsequent transfer of the mutant allele to the genome of the host organism in place of the wild-type gene. However, due to their intrinsic resistance to many antibiotics only selected antibiotic-resistance markers can be used in members of the genus Burkholderia, including the Burkholderia cepacia complex (Bcc). Here we describe the construction of improved antibiotic-resistance cassettes that specify resistance to kanamycin, chloramphenicol or trimethoprim effectively in the Bcc and related species. These were then used in combination with and/or to construct a series enhanced suicide vectors, pSHAFT2, pSHAFT3 and pSHAFT-GFP to facilitate effective allelic replacement in the Bcc. Validation of these improved suicide vectors was demonstrated by the genetic inactivation of selected genes in the Bcc species Burkholderia cenocepacia and B. lata, and in the non-Bcc species, B. thailandensis. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Detection of misidentifications of species from the Burkholderia cepacia complex and description of a new member, the soil bacterium Burkholderia catarinensis sp. nov.

PubMed

Bach, Evelise; Sant'Anna, Fernando Hayashi; Magrich Dos Passos, João Frederico; Balsanelli, Eduardo; de Baura, Valter Antonio; Pedrosa, Fábio de Oliveira; de Souza, Emanuel Maltempi; Passaglia, Luciane Maria Pereira

2017-08-31

The correct identification of bacteria from the Burkholderia cepacia complex (Bcc) is crucial for epidemiological studies and treatment of cystic fibrosis infections. However, genome-based identification tools are revealing many controversial Bcc species assignments. The aim of this work is to re-examine the taxonomic position of the soil bacterium B. cepacia 89 through polyphasic and genomic approaches. recA and 16S rRNA gene sequence analysis positioned strain 89 inside the Bcc group. However, based on the divergence score of seven concatenated allele sequences, and values of average nucleotide identity, and digital DNA:DNA hybridization, our results suggest that strain 89 is different from other Bcc species formerly described. Thus, we propose to classify Burkholderia sp. 89 as the novel species Burkholderia catarinensis sp. nov. with strain 89T (=DSM 103188T = BR 10601T) as the type strain. Moreover, our results call the attention to some probable misidentifications of Bcc genomes at the National Center for Biotechnology Information database. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Structural phase transitions in Bi2Se3 under high pressure

PubMed Central

Yu, Zhenhai; Wang, Lin; Hu, Qingyang; Zhao, Jinggeng; Yan, Shuai; Yang, Ke; Sinogeikin, Stanislav; Gu, Genda; Mao, Ho-kwang

2015-01-01

Raman spectroscopy and angle dispersive X-ray diffraction (XRD) experiments of bismuth selenide (Bi2Se3) have been carried out to pressures of 35.6 and 81.2 GPa, respectively, to explore its pressure-induced phase transformation. The experiments indicate that a progressive structural evolution occurs from an ambient rhombohedra phase (Space group (SG): R-3m) to monoclinic phase (SG: C2/m) and eventually to a high pressure body-centered tetragonal phase (SG: I4/mmm). Evidenced by our XRD data up to 81.2 GPa, the Bi2Se3 crystallizes into body-centered tetragonal structures rather than the recently reported disordered body-centered cubic (BCC) phase. Furthermore, first principles theoretical calculations favor the viewpoint that the I4/mmm phase Bi2Se3 can be stabilized under high pressure (>30 GPa). Remarkably, the Raman spectra of Bi2Se3 from this work (two independent runs) are still Raman active up to ~35 GPa. It is worthy to note that the disordered BCC phase at 27.8 GPa is not observed here. The remarkable difference in atomic radii of Bi and Se in Bi2Se3 may explain why Bi2Se3 shows different structural behavior than isocompounds Bi2Te3 and Sb2Te3. PMID:26522818

Structural phase transitions in Bi 2Se 3 under high pressure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Zhenhai; Gu, Genda; Wang, Lin

2015-11-02

Raman spectroscopy and angle dispersive X-ray diffraction (XRD) experiments of bismuth selenide (Bi 2Se 3) have been carried out to pressures of 35.6 and 81.2 GPa, respectively, to explore its pressure-induced phase transformation. The experiments indicate that a progressive structural evolution occurs from an ambient rhombohedra phase (Space group (SG): R-3m) to monoclinic phase (SG: C2/m) and eventually to a high pressure body-centered tetragonal phase (SG: I4/mmm). Evidenced by our XRD data up to 81.2 GPa, the Bi 2Se 3 crystallizes into body-centered tetragonal structures rather than the recently reported disordered body-centered cubic (BCC) phase. Furthermore, first principles theoretical calculationsmore » favor the viewpoint that the I4/mmm phase Bi 2Se 3 can be stabilized under high pressure (>30 GPa). Remarkably, the Raman spectra of Bi 2Se 3 from this work (two independent runs) are still Raman active up to ~35 GPa. Furthermore, it is worthy to note that the disordered BCC phase at 27.8 GPa is not observed here. The remarkable difference in atomic radii of Bi and Se in Bi 2Se 3 may explain why Bi 2Se 3 shows different structural behavior than isocompounds Bi 2Te 3 and Sb 2Te 3.« less

Crystal-to-glass-transition induced elastic anomaly of cerium-iron multilayer films and texture-related mechanical properties after hydrogenation

NASA Astrophysics Data System (ADS)

Hassdorf, R.; Arend, M.; Felsch, W.

1995-04-01

The flexural modulus EF of pure and hydrided cerium-iron multilayer films has been measured at 300 K as a function of the modulation wavelength Λ using a vibrating-reed technique. EF is strongly correlated to the structure of the layered systems. In the pure Ce/Fe multilayers, the Fe sublayers show a structural transition from an amorphous to the bcc crystalline phase for a thickness near 20 Å. At this transition, the modulus EF is reduced by ~70%. The elastic softening occurs already, as a precursor to the structural change, for the crystalline Fe sublayers somewhat above the thickness for amorphous growth. This behavior reveals close similarities to the crystal-to-glass transition in bulk metallic alloys and compounds which seems to be driven by a shear instability of the crystal lattice. Hydrogenation leads to multilayers built of CeH~2/Fe. The Fe sublayers grow in the bcc structure above 10 Å, with a pronounced (110) or (111) texture for low- or room-temperature deposition. The flexural moduli are larger as compared to the nonhydrided multilayers and distinctly different for the two Fe textures. A simple calculation shows that the texture-related differences mainly result from the bulk properties of the Fe layers, but a contribution of interfacial effects cannot be excluded.

Microstructural Evolution of AlCoCrFeNiSi High-Entropy Alloy Powder during Mechanical Alloying and Its Coating Performance

PubMed Central

Fu, Ming; Xiong, Wei

2018-01-01

High-entropy alloys (HEAs) are promising structural materials due to their excellent comprehensive performances. The use of mechanically alloyed powders to deposit HEA coatings through atmospheric plasma spraying (APS) is an effective approach that can broaden the application areas of the HEAs. In this paper, a ductility–brittleness AlCoCrFeNiSi system was chosen as an object of study, and the detailed evolution of the surface morphology, particle size distribution, and microstructure of the powder during mechanical alloying was investigated. An AlCoCrFeNiSi HEA coating was deposited using powder milled for 10 h, which can be used as an ideal feedstock for APS. The surface morphology, microstructure, microhardness, and wear behavior of the coating at room temperature were investigated. The results showed that as the milling time increased, the particle size first increased, and then decreased. At the milling time of 10 h, simple body-centered cubic (BCC) and face-centered cubic (FCC) solid solution phases were formed. After spraying, the lamellar structure inside a single particle disappeared. An ordered BCC phase was detected, and the diffraction peaks of the Si element also disappeared, which indicates that phase transformation occurred during plasma spraying. A transmission electron microscopy analysis showed that nanometer crystalline grains with a grain size of about 30 nm existed in the APS coating. For the coating, an average microhardness of 612 ± 41 HV was obtained. Adhesive wear, tribo-oxidation wear, and slight abrasion wear took place during the wear test. The coating showed good wear resistance, with a volume wear rate of 0.38 ± 0.08 × 10−4 mm3·N−1·m−1, which makes it a promising coating for use in abrasive environments. PMID:29473872

Phase stability and microstructures of high entropy alloys ion irradiated to high doses

NASA Astrophysics Data System (ADS)

Xia, Songqin; Gao, Michael C.; Yang, Tengfei; Liaw, Peter K.; Zhang, Yong

2016-11-01

The microstructures of AlxCoCrFeNi (x = 0.1, 0.75 and 1.5 in molar ratio) high entropy alloys (HEAs) irradiated at room temperature with 3 MeV Au ions at the highest fluence of 105, 91, and 81 displacement per atom, respectively, were studied. Transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) analyses show that the initial microstructures and phase composition of all three alloys are retained after ion irradiation and no phase decomposition is observed. Furthermore, it is demonstrated that the disordered face-centered cubic (FCC) and disordered body-centered cubic (BCC) phases show much less defect cluster formation and structural damage than the NiAl-type ordered B2 phase. This effect is explained by higher entropy of mixing, higher defect formation/migration energies, substantially lower thermal conductivity, and higher atomic level stress in the disordered phases.

Community perceptions of behaviour change communication interventions of the maternal neonatal and child health programme in rural Bangladesh: an exploratory study.

PubMed

Rahman, Atiya; Leppard, Margaret; Rashid, Sarawat; Jahan, Nauruj; Nasreen, Hashima E

2016-08-16

This qualitative study explored community perceptions of the components of the behaviour change communication (BCC) intervention of the BRAC Improving Maternal, Neonatal and Child Survival (IMNCS) programme in rural Bangladesh. Semi-structured interviews, key informant interviews, focus group discussions and informal group discussions were conducted to elicit community views on interpersonal communication (IPC), printed materials, entertainment education (EE) and mass media, specifically (a) acceptance of and challenges presented by different forms of media, (b) comprehensibility of terms; printed materials and entertainment education and (c) reported influence of BCC messages. IMNCS BCC interventions are well accepted by the community people. IPC is considered an essential aspect of everyday life and community members appreciate personal interaction with the BRAC community health workers. Printed materials assisted in comprehension and memorization of messages particularly when explained by community health workers (CHW) during IPC. Enactment of maternal, neonatal and child health (MNCH) narratives and traditional musical performances in EE helped to give deep insight into life's challenges and the decision making that is inherent in pregnancy, childbirth and childcare. EE also improved memorization of the messages. Some limitations were identified in design of illustrations which hampered message comprehension. Some respondents were unable to differentiate between pregnancy, delivery and postpartum danger signs. Furthermore some women were afraid to view the illustrations of danger signs as they believed seeing that might be associated with the development of these complications in their own lives. Despite these barriers, participants stated that the IMNCS BCC interventions had influenced them to take health promoting decisions and seek MNCH services. Community based maternal and newborn programmes should revise BCC interventions to strengthen IPC, using rigorously tested print materials as aids and stand-alone media. Messages about birth preparedness (especially savings), recognition of danger signs and immediate self-referral to biomedical health services should be carefully aligned and effectively delivered to women, men and older members of the community. Messaging should utilize gendered storyline and address the seasonal cycles of conception, birth, antenatal, post-natal care and childhood illnesses. Future research should identify how best to combine IPC, printed materials, traditional cultural forms, and incorporate use of social media and mass media in different field situations.

Chronicle of a pigmented superficial Basal cell carcinoma.

PubMed

Caucanas, Marie; Piérard-Franchimont, Claudine; Piérard, Gérald E

2012-01-01

Dermoscopic patterns of basal cell carcinoma (BCC) are well defined, but the dynamics of dermoscopic changes in time were apparently never described so far. In this paper, prominent changes were observed over a 8-week period, allowing to establish a close connection between spoke wheel areas and maple leaf-like aspects, through progressive thickening of the former ones. A chronobiological phenomenon ruling synchronous apoptosis in some of the most superficial BCC nests is suggested, leading to a wax and wane process of millimetric crusts, taking part in the spontaneous BCC regression/progression process.

Mechanical Properties of Nb25Mo25Ta25W25 and V20Nb20Mo20Ta20W20 Refractory High Entropy Alloys (Postprint)

DTIC Science & Technology

2011-05-01

Mn, Fe, Co, Ni and Cu. Since metallic alloys for high temperature load bearing structures and thermal protection systems remain in high demand for aer...condition. These results indicate that the BCC crystal structure formed in both alloys during solidification is stable upon heating at least up to 1400 C... solidification (Fig. 5b). Higher magnification images reveal a dendritic structure in both alloys (Fig. 5c and d). Uneven Z contrast inside the grains indicates

One-stop-shop with confocal microscopy imaging vs. standard care for surgical treatment of basal cell carcinoma: an open-label, noninferiority, randomized controlled multicentre trial.

PubMed

Kadouch, D J; Elshot, Y S; Zupan-Kajcovski, B; van Haersma de With, A S E; van der Wal, A C; Leeflang, M; Jóźwiak, K; Wolkerstorfer, A; Bekkenk, M W; Spuls, P I; de Rie, M A

2017-09-01

Routine punch biopsies are considered to be standard care for diagnosing and subtyping basal cell carcinoma (BCC) when clinically suspected. We assessed the efficacy of a one-stop-shop concept using in vivo reflectance confocal microscopy (RCM) imaging as a diagnostic tool vs. standard care for surgical treatment in patients with clinically suspected BCC. In this open-label, parallel-group, noninferiority, randomized controlled multicentre trial we enrolled patients with clinically suspected BCC at two tertiary referral centres in Amsterdam, the Netherlands. Patients were randomly assigned to the RCM one-stop-shop (diagnosing and subtyping using RCM followed by direct surgical excision) or standard care (planned excision based on the histological diagnosis and subtype of a punch biopsy). The primary outcome was the proportion of patients with tumour-free margins after surgical excision of BCC. Of the 95 patients included, 73 (77%) had a BCC histologically confirmed using a surgical excision specimen. All patients (40 of 40, 100%) in the one-stop-shop group had tumour-free margins. In the standard-care group tumour-free margins were found in all but two patients (31 of 33, 94%). The difference in the proportion of patients with tumour-free margins after BCC excision between the one-stop-shop group and the standard-care group was -0·06 (90% confidence interval -0·17-0·01), establishing noninferiority. The proposed new treatment strategy seems suitable in facilitating early diagnosis and direct treatment for patients with BCC, depending on factors such as availability of RCM, size and site of the lesion, patient preference and whether direct surgical excision is feasible. © 2017 The Authors. British Journal of Dermatology published by John Wiley & Sons Ltd on behalf of British Association of Dermatologists.

SOCS3 inhibits the pathological effects of IL-22 in non-melanoma skin tumor-derived keratinocytes.

PubMed

Madonna, Stefania; Scarponi, Claudia; Morelli, Martina; Sestito, Rosanna; Scognamiglio, Pasqualina Liana; Marasco, Daniela; Albanesi, Cristina

2017-04-11

Basal cell carcinomas (BCC) and squamous-cell carcinomas (SCC) are common malignancies in humans, caused by neoplastic transformation of keratinocytes of the basal or suprabasal layers of epidermis, respectively. Tumor-infiltrating lymphocytes (TILs) are frequently found in BCC and SCC, and functionally promote epithelial carcinogenesis. TILs secreting IL-22, in particular, participate to BCC and SCC growth by inducing keratinocyte proliferation and migration, as well as the expression of inflammatory, anti-apoptotic and pro-angiogenic genes.In this study, we identified SOCS3 as a valid candidate to be manipulated for suppressing tumorigenic functions in BCC and SCC. We found that SOCS3 and SOCS1 expression was reduced in vivo, in tumor lesions of BCC and SCC, as compared to other skin inflammatory conditions such as psoriasis, despite the high number of IL-22-secreting TILs. Moreover, IL-22 was not able to induce in vitro the transcriptional expression of SOCS3 in BCC-or SCC-derived keratinocytes, contrarily to healthy cells. Aimed at rescuing SOCS3 activity in these tumor contexts, a SOCS3-derived peptide, named KIR-ESS, was synthesized, and its ability in suppressing IL-22-induced responses was evaluated in healthy and transformed keratinocytes. We found that KIR-ESS peptide efficiently suppressed the IL-22 molecular signaling in keratinocytes, by acting on STAT3 and Erk1/2 cascade, as well as on the expression of STAT3-dependent downstream genes. Interestingly, after treatment with peptide, both healthy and transformed keratinocytes could no longer aberrantly proliferate and migrate in response to IL-22. Finally, treatment of athymic nude mice bearing SCC xenografts with KIR-ESS peptide concomitantly reduced tumor growth and activated STAT3 levels. As a whole, these data provides the rationale for the use in BCC and SCC skin tumors of SOCS3 mimetics, being able to inhibit the deleterious effects of IL-22 in these contexts.

Basal cell carcinoma: 10-year experience with electrochemotherapy.

PubMed

Campana, Luca G; Marconato, Roberto; Valpione, Sara; Galuppo, Sara; Alaibac, Mauro; Rossi, Carlo R; Mocellin, Simone

2017-05-31

Electrochemotherapy (ECT), by combining manageable cytotoxic agents with short electric pulses, represents an effective palliative skin-directed therapy. The accumulated evidence indicates that ECT stands out as a safe and well-tolerated alternative treatment for patients with multiple or large basal cell carcinoma (BCC), who are not suitable for conventional treatments. However, long-term data and shared indications are lacking. In this observational study, we retrospectively analyzed 84 prospectively collected patients with multiple, recurrent or locally advanced BCC who were not candidate for standard therapies and received bleomycin-based ECT according to the European Standard Operative Procedures of ECT, from 2006 to 2016. Disease extent was local, locally advanced and metastatic in 40 (48%), 41 (49%) and 3 (3%), respectively. Forty-four (52%) individuals had multiple BCCs. Grade 3 skin toxicity after ECT was observed in 6% of cases. Clearance rate was 50% (95% CI 39-61%). Primary presentation (p = 0.004), tumor size <3 cm (p < 0.001), well-defined borders (p = 0.021), absence of tumor ulceration (p = 0.001), non-aggressive BCC histology (p = 0.046) and age ≤69 years were associated with higher complete response rate. In patients with local BCC, the clearance rate was 72.5 and 85% after one or two ECT cycles, respectively. In the laBCC group, 32 patients (78%) achieved an objective response. Five-year recurrence rate for local and laBCC was 20 and 38%, respectively (p ≤ 0.001). One or two ECT cycles with bleomycin may be a valuable palliative treatment in well-selected patients with multiple BCCs and favorable tumor features. Validation of predictive factors will be imperative to match patients with optimal ECT treatment modalities. Management of laBCC with ECT warrants further investigation. Trial registration ISRCTN14633165 Registered 24 March 2017 (retrospectively registered).

SOCS3 inhibits the pathological effects of IL-22 in non-melanoma skin tumor-derived keratinocytes

PubMed Central

Madonna, Stefania; Scarponi, Claudia; Morelli, Martina; Sestito, Rosanna; Scognamiglio, Pasqualina Liana; Marasco, Daniela; Albanesi, Cristina

2017-01-01

Basal cell carcinomas (BCC) and squamous-cell carcinomas (SCC) are common malignancies in humans, caused by neoplastic transformation of keratinocytes of the basal or suprabasal layers of epidermis, respectively. Tumor-infiltrating lymphocytes (TILs) are frequently found in BCC and SCC, and functionally promote epithelial carcinogenesis. TILs secreting IL-22, in particular, participate to BCC and SCC growth by inducing keratinocyte proliferation and migration, as well as the expression of inflammatory, anti-apoptotic and pro-angiogenic genes. In this study, we identified SOCS3 as a valid candidate to be manipulated for suppressing tumorigenic functions in BCC and SCC. We found that SOCS3 and SOCS1 expression was reduced in vivo, in tumor lesions of BCC and SCC, as compared to other skin inflammatory conditions such as psoriasis, despite the high number of IL-22-secreting TILs. Moreover, IL-22 was not able to induce in vitro the transcriptional expression of SOCS3 in BCC-or SCC-derived keratinocytes, contrarily to healthy cells. Aimed at rescuing SOCS3 activity in these tumor contexts, a SOCS3-derived peptide, named KIR-ESS, was synthesized, and its ability in suppressing IL-22-induced responses was evaluated in healthy and transformed keratinocytes. We found that KIR-ESS peptide efficiently suppressed the IL-22 molecular signaling in keratinocytes, by acting on STAT3 and Erk1/2 cascade, as well as on the expression of STAT3-dependent downstream genes. Interestingly, after treatment with peptide, both healthy and transformed keratinocytes could no longer aberrantly proliferate and migrate in response to IL-22. Finally, treatment of athymic nude mice bearing SCC xenografts with KIR-ESS peptide concomitantly reduced tumor growth and activated STAT3 levels. As a whole, these data provides the rationale for the use in BCC and SCC skin tumors of SOCS3 mimetics, being able to inhibit the deleterious effects of IL-22 in these contexts. PMID:28445952

Applying behavioral science to behavior change communication: the pathways to change tools.

PubMed

Petraglia, Joseph; Galavotti, Christine; Harford, Nicola; Pappas-DeLuca, Katina A; Mooki, Maungo

2007-10-01

Entertainment-education (EE) is a popular vehicle for behavior change communication (BCC) in many areas of public health, especially in the developing world where soap operas and other serial drama formats play a central role in encouraging people to avoid risky behavior. Yet BCC/EE developers have been largely unable to integrate behavioral theory and research systematically into storylines and scripts, depending instead on external, technical oversight of what should be an essentially local, creative process. This article describes how the Modeling and Reinforcement to Combat HIV/AIDS project at the Centers for Disease Control and Prevention has developed a set of tools through which creative writers can exercise greater control over the behavioral content of their stories. The Pathways to Change tools both guide scriptwriters as they write BCC/EE storylines and help project managers monitor BCC/EE products for theoretical fidelity and sensitivity to research.

The diagram of phase-field crystal structures: an influence of model parameters in a two-mode approximation

NASA Astrophysics Data System (ADS)

Ankudinov, V.; Galenko, P. K.

2017-04-01

Effect of phase-field crystal model (PFC-model) parameters on the structure diagram is analyzed. The PFC-model is taken in a two-mode approximation and the construction of structure diagram follows from the free energy minimization and Maxwell thermodynamic rule. The diagram of structure’s coexistence for three dimensional crystal structures [Body-Centered-Cubic (BCC), Face-Centered-Cubic (FCC) and homogeneous structures] are constructed. An influence of the model parameters, including the stability parameters, are discussed. A question about the structure diagram construction using the two-mode PFC-model with the application to real materials is established.

Tight-Binding study of Boron structures

NASA Astrophysics Data System (ADS)

McGrady, Joseph W.; Papaconstantopoulos, Dimitrios A.; Mehl, Michael J.

2014-10-01

We have performed Linearized Augmented Plane Wave (LAPW) calculations for five crystal structures (alpha, dhcp, sc, fcc, bcc) of Boron which we then fitted to a non-orthogonal tight-binding model following the Naval Research Laboratory Tight-Binding (NRL-TB) method. The predictions of the NRL-TB approach for complicated Boron structures such as R105 (or β-rhombohedral) and T190 are in agreement with recent first-principles calculations. Fully utilizing the computational speed of the NRL-TB method we calculated the energy differences of various structures, including those containing vacancies using supercells with up to 5000 atoms.

Alcohol intake and early-onset basal cell carcinoma in a case-control study

PubMed Central

Zhang, Y; Ferrucci, L.M.; Cartmel, B.; Molinaro, A.M.; Leffell, D.J.; Bale, A.E.; Mayne, S.T.

2014-01-01

Background Previous epidemiologic studies of overall alcohol intake and basal cell carcinoma (BCC) are inconsistent, with some evidence for differences by type of alcoholic beverage. While alcohol may enhance the carcinogenicity of ultraviolet (UV) light, this has not been evaluated in existing epidemiologic studies. Objective To evaluate alcohol intake in relation to early-onset BCC, and explore potential interactions with UV exposure. Methods BCC cases (n=380) and controls with benign skin conditions (n=390) under age 40 were identified through Yale Dermatopathology. Participants provided information on lifetime alcohol intake, including type of beverage during an in-person interview. Self-report data on indoor tanning and outdoor sunbathing were used to categorize UV exposure. We calculated odds ratios (OR) and 95% confidence intervals (CI) using unconditional multivariate logistic regression in the full sample and in women only. Results There was no statistically significant association between lifetime alcohol intake and early-onset BCC overall (above median intake vs. no regular alcohol intake OR 1.10, 95% CI 0.69-1.73) or in women only (OR 1.21, 95% CI 0.73-2.01). Similarly, intake of red wine, white wine, beer or hard liquor and mixed drinks was not associated with early-onset BCC. In exploratory analyses, we saw limited evidence for an interaction (pinteraction=0.003), with highest risk for high alcohol and high UV exposures, especially in women, but subgroup risk estimates had wide and overlapping confidence intervals. Conclusions Overall, we did not observe any clear association between lifetime alcohol intake and early-onset BCC. PMID:25059635

Characterization of the volatile profile of Antarctic bacteria by using solid-phase microextraction-gas chromatography-mass spectrometry.

PubMed

Romoli, Riccardo; Papaleo, Maria Cristiana; de Pascale, Donatella; Tutino, Maria Luisa; Michaud, Luigi; LoGiudice, Angelina; Fani, Renato; Bartolucci, Gianluca

2011-10-01

Bacteria belonging to the Burkholderia cepacia complex (Bcc) are significant pathogens in Cystic Fibrosis (CF) patients and are resistant to a plethora of antibiotics. In this context, microorganisms from Antarctica are interesting because they produce antimicrobial compounds inhibiting the growth of other bacteria. This is particularly true for bacteria isolated from Antarctic sponges. The aim of this work was to characterize a set of Antarctic bacteria for their ability to produce new natural drugs that could be exploited in the control of infections in CF patients by Bcc bacteria. Hence, 11 bacterial strains allocated to different genera (e.g., Pseudoalteromonas, Arthrobacter and Psychrobacter) were tested for their ability to inhibit the growth of 21 Bcc strains and some other human pathogens. All these bacteria completely inhibited the growth of most, if not all, Bcc strains, suggesting a highly specific activity toward Bcc strains. Experimental evidences showed that the antimicrobial compounds are small volatile organic compounds, and are constitutively produced via an unknown pathway. The microbial volatile profile was obtained by SPME-GC-MS within the m/z interval of 40-450. Solid phase micro extraction technique affords the possibility to extract the volatile compounds in head space with a minimal sample perturbation. Principal component analysis and successive cluster discriminant analysis was applied to evaluate the relationships among the volatile organic compounds with the aim of classifying the microorganisms by their volatile profile. These data highlight the potentiality of Antarctic bacteria as novel sources of antibacterial substances to face Bcc infections in CF patients. Copyright © 2011 John Wiley & Sons, Ltd.

Burkholderia puraquae sp. nov., a novel species of the Burkholderia cepacia complex isolated from hospital settings and agricultural soils.

PubMed

Martina, Pablo; Leguizamon, Mariana; Prieto, Claudia I; Sousa, Silvia A; Montanaro, Patricia; Draghi, Walter O; Stämmler, Maren; Bettiol, Marisa; de Carvalho, Carla C C R; Palau, Juliana; Figoli, Cecilia; Alvarez, Florencia; Benetti, Silvina; Lejona, Sergio; Vescina, Cecilia; Ferreras, Julián; Lasch, Peter; Lagares, Antonio; Zorreguieta, Angeles; Leitão, Jorge H; Yantorno, Osvaldo M; Bosch, Alejandra

2018-01-01

Bacteria from the Burkholderia cepacia complex (Bcc) are capable of causing severe infections in patients with cystic fibrosis (CF). These opportunistic pathogens are also widely distributed in natural and man-made environments. After a 12-year epidemiological surveillance involving Bcc bacteria from respiratory secretions of Argentinean patients with CF and from hospital settings, we found six isolates of the Bcc with a concatenated species-specific allele sequence that differed by more than 3 % from those of the Bcc with validly published names. According to the multilocus sequence analysis (MLSA), these isolates clustered with the agricultural soil strain, Burkholderia sp. PBP 78, which was already deposited in the PubMLST database. The isolates were examined using a polyphasic approach, which included 16S rRNA, recA, Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), DNA base composition, average nucleotide identities (ANIs), fatty acid profiles, and biochemical characterizations. The results of the present study demonstrate that the seven isolates represent a single novel species within the Bcc, for which the name Burkholderia puraquae sp. nov. is proposed. Burkholderia puraquae sp. nov. CAMPA 1040 T (=LMG 29660 T =DSM 103137 T ) was designated the type strain of the novel species, which can be differentiated from other species of the Bcc mainly from recA gene sequence analysis, MLSA, ANIb, MALDI-TOF MS analysis, and some biochemical tests, including the ability to grow at 42 °C, aesculin hydrolysis, and lysine decarboxylase and β-galactosidase activities.

Heterogeneous relationships of squamous and basal cell carcinomas of the skin with smoking: the UK Million Women Study and meta-analysis of prospective studies.

PubMed

Pirie, Kirstin; Beral, Valerie; Heath, Alicia K; Green, Jane; Reeves, Gillian K; Peto, Richard; McBride, Penelope; Olsen, Catherine M; Green, Adèle C

2018-06-14

Published findings on the associations between smoking and the incidence of cutaneous squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) are inconsistent. We aimed to generate prospective evidence on these relationships overall and by anatomical site. We followed 1,223,626 women without prior cancer by electronic linkage to national cancer registration data. Questionnaire information about smoking and other factors was recorded at recruitment (1996-2001) and every 3-5 years subsequently. Cox regression yielded adjusted relative risks (RRs) comparing smokers versus never-smokers. After 14 (SD4) years follow-up per woman, 6699 had a first registered cutaneous SCC and 48,666 a first BCC. In current versus never-smokers, SCC incidence was increased (RR = 1.22, 95% CI 1.15-1.31) but BCC incidence was decreased (RR = 0.80, 0.78-0.82). RRs varied substantially by anatomical site; for the limbs, current smoking was associated with an increased incidence of SCC (1.55, 1.41-1.71) and a decreased incidence of BCC (0.72, 0.66-0.79), but for facial lesions there was little association of current smoking with either SCC (0.93, 0.82-1.06) or BCC (0.92, 0.88-0.96). Findings in meta-analyses of results from this and seven other prospective studies were largely dominated by the findings in this study. Smoking-associated risks for cutaneous SCC and BCC are in the opposite direction to each other and appear to vary by anatomical site.

Association between genetic variation within vitamin D receptor-DNA binding sites and risk of basal cell carcinoma.

PubMed

Lin, Yuan; Chahal, Harvind S; Wu, Wenting; Cho, Hyunje G; Ransohoff, Katherine J; Dai, Hongji; Tang, Jean Y; Sarin, Kavita Y; Han, Jiali

2017-05-01

An increasing number of studies have reported a protective association between vitamin D and cancer risk. The vitamin D endocrine system regulates transcriptional programs involved in inflammation, cell growth and differentiation through the binding of vitamin D receptor (VDR) to specific VDR elements. However, limited attention has been given to the role of variation within VDR binding sites in the development of basal cell carcinoma (BCC). Across 2,776 previously identified VDR binding sites, we identified 2,540 independent single-nucleotide polymorphisms (SNPs) and examined their associations with BCC risk in a genome-wide association meta-analysis totaling 17,187 BCC cases and 287,054 controls from two data sets. After multiple testing corrections, we identified two SNPs at new loci (rs16917546 at 10q21.1: odds ratio (OR) = 1.06, p = 3.16 × 10 -7 and rs79824801 at 12q13.3: OR = 1.10, p = 1.88 × 10 -5 ) for the first time as independently related to BCC risk in meta-analysis; and both SNPs were nominally significant in two data sets. In addition, the SNP rs3769823 within VDR binding site at a previously reported BCC susceptibility locus (2q33.1, rs13014235) also exhibited a significant association (OR = 1.12, p = 3.99 × 10 -18 ). A mutually adjusted model suggested that rs3769823 explained the signal in this region. Our findings support the hypothesis that inherited common variation in VDR binding sites affects the development of BCC. © 2017 UICC.

Follow-up of basal cell carcinomas: an audit of current practice.

PubMed

Mc Loone, N M; Tolland, J; Walsh, M; Dolan, O M

2006-07-01

Follow-up of patients after treatment of basal cell carcinoma (BCC) allows for monitoring of recurrence and detection of new tumours, but adds a significant burden to outpatient clinics. At the skin tumour clinic in the dermatology department, the Royal Hospitals, Belfast, all patients are reviewed for 2 years after surgical excision of a low-risk primary BCC. An audit was undertaken to determine the quality of data set recorded relating to prognostic factors for BCCs to determine the rate of recurrence and number of new primary tumours detected and to determine the completeness of follow-up by patients. Patients who had primary BCCs treated by excision were identified from a database held at the clinic. Medical charts were reviewed to determine data recorded about lesions, the number of recurrent BCCs and new tumours detected, and the number of patients completing follow-up. Between January 1999 and December 2000, 114 patients had 121 primary BCCs excised. BCC location and size were recorded in 100% and 35% of cases, respectively. Histological type was stated for morphoeic or multifocal lesions. Two years of follow-up was completed by 53% of patients and 1 year by 78% of patients. The rate of recurrence was low, with 2 BCC recurring within 2 years of excision. The risk of developing a new BCC was 11.6% in the first year and 6.3% in the second year. Follow-up of patients after excision of a low-risk BCC at the clinic has been reduced to 1 year. A proforma has been developed to encourage documentation of prognostic factors.

Fish-mediated changes in bacterioplankton community composition: an in situ mesocosm experiment

NASA Astrophysics Data System (ADS)

Luo, Congqiang; Yi, Chunlong; Ni, Leyi; Guo, Longgen

2017-06-01

We characterized variations in bacterioplankton community composition (BCC) in mesocosms subject to three different treatments. Two groups contained fish (group one: Cyprinus carpio; group two: Hypophthalmichthys molitrix); and group three, the untreated mesocosm, was the control. Samples were taken seven times over a 49-day period, and BCC was analyzed by PCR-denaturing gradient gel electrophoresis (DGGE) and real-time quantitative PCR (qPCR). Results revealed that introduction of C. carpio and H. molitrix had a remarkable impact on the composition of bacterioplankton communities, and the BCC was significantly different between each treatment. Sequencing of DGGE bands revealed that the bacterioplankton community in the different treatment groups was consistent at a taxonomic level, but differed in its abundance. H. molitrix promoted the richness of Alphaproteobacteria and Actinobacteria, while more bands affiliated to Cyanobacteria were detected inC. carpio mesocosms. The redundancy analysis (RDA) result demonstrated that the BCC was closely related to the bottom-up (total phosphorus, chlorophyll a, phytoplankton biomass) and top-down forces (biomass of copepods and cladocera) in C. carpio and control mesocosms, respectively. We found no evidence for top-down regulation of BCC by zooplankton in H. molitrix mesocosms, while grazing by protozoa (heterotrophic nanoflagellates, ciliates) became the major way to regulate BCC. Total bacterioplankton abundances were significantly higher in C. carpio mesocosms because of high nutrient concentration and suspended solids. Our study provided insights into the relationship between fish and bacterioplankton at species level, leading to a deep understanding of the function of the microbial loop and the aquatic ecosystem.

Tea, coffee, and caffeine and early-onset basal cell carcinoma in a case-control study

PubMed Central

Ferrucci, Leah M.; Cartmel, Brenda; Molinaro, Annette M.; Leffell, David J.; Bale, Allen E.; Mayne, Susan T.

2014-01-01

Objectives Tea and coffee are hypothesized to play a protective role in skin carcinogenesis via bioactive components, such as caffeine, yet the epidemiologic evidence is mixed. Existing data supports an inverse association with basal cell carcinoma (BCC) more so than for melanoma or squamous cell carcinoma. To understand if tea, coffee, and caffeine are related to early-onset BCC, we evaluated data from 767 non-Hispanic Whites under age 40 in a case-control study in Connecticut. Methods BCC cases (n=377) were identified through Yale's Dermatopathology database. Controls (n=390) were randomly sampled from individuals in the same database with benign skin diagnoses and frequency matched to cases on age, gender, and biopsy site. Subjects completed an in-person interview including assessment of caffeinated coffee and hot tea. We calculated multivariate odds ratios (OR) and 95% confidence intervals (CIs) with unconditional logistic regression for regular consumption and frequency and duration measures. Results Combined regular consumption of caffeinated coffee plus hot tea was inversely associated with early-onset BCC (OR=0.60, 95% CI=0.38–0.96). Those in the highest category of caffeine from these sources had a 43% reduced risk of BCC compared to non-consumers (OR=0.57, 95% CI=0.34–0.95, p-trend=0.037). Conclusions Our findings suggest a modest protective effect for caffeinated coffee plus tea in relation to early-onset BCC that may, in part, be due to caffeine. This study adds to the growing body of literature suggesting potential health benefits from these beverages. PMID:24841641

Tea, coffee, and caffeine and early-onset basal cell carcinoma in a case-control study.

PubMed

Ferrucci, Leah M; Cartmel, Brenda; Molinaro, Annette M; Leffell, David J; Bale, Allen E; Mayne, Susan T

2014-07-01

Tea and coffee are hypothesized to play a protective role in skin carcinogenesis through bioactive components, such as caffeine, yet the epidemiologic evidence is mixed. Existing data support an inverse association with basal cell carcinoma (BCC), more so than for melanoma or squamous cell carcinoma. To understand whether tea, coffee, and caffeine are related to early-onset BCC, we evaluated data from 767 non-Hispanic Whites under age 40 in a case-control study in Connecticut. BCC cases (n=377) were identified through Yale's Dermatopathology database. Controls (n=390) were randomly sampled from individuals in the same database with benign skin diagnoses and frequency matched to cases on age, sex, and biopsy site. Participants completed an in-person interview including assessment of caffeinated coffee and hot tea. We calculated multivariate odds ratios (ORs) and 95% confidence intervals (CIs) with unconditional logistic regression for regular consumption and frequency and duration measures. Combined regular consumption of caffeinated coffee plus hot tea was inversely associated with early-onset BCC (OR=0.60, 95% CI=0.38-0.96). Those in the highest category of caffeine from these sources had a 43% reduced risk of BCC compared with nonconsumers (OR=0.57, 95% CI=0.34-0.95, P-trend=0.037). Our findings suggest a modest protective effect for caffeinated coffee plus tea in relation to early-onset BCC that may, in part, be due to caffeine. This study adds to the growing body of literature suggesting potential health benefits from these beverages.

Fish-mediated changes in bacterioplankton community composition: an in situ mesocosm experiment

NASA Astrophysics Data System (ADS)

Luo, Congqiang; Yi, Chunlong; Ni, Leyi; Guo, Longgen

2018-03-01

We characterized variations in bacterioplankton community composition (BCC) in mesocosms subject to three different treatments. Two groups contained fish (group one: Cyprinus carpio; group two: Hypophthalmichthys molitrix); and group three, the untreated mesocosm, was the control. Samples were taken seven times over a 49-d period, and BCC was analyzed by PCR-denaturing gradient gel electrophoresis (DGGE) and real-time quantitative PCR (qPCR). Results revealed that introduction of C. carpio and H. molitrix had a remarkable impact on the composition of bacterioplankton communities, and the BCC was significantly different between each treatment. Sequencing of DGGE bands revealed that the bacterioplankton community in the different treatment groups was consistent at a taxonomic level, but differed in its abundance. H. molitrix promoted the richness of Alphaproteobacteria and Actinobacteria, while more bands affiliated to Cyanobacteria were detected in C. carpio mesocosms. The redundancy analysis (RDA) result demonstrated that the BCC was closely related to the bottom-up (total phosphorus, chlorophyll a, phytoplankton biomass) and top-down forces (biomass of copepods and cladocera) in C. carpio and control mesocosms, respectively. We found no evidence for top-down regulation of BCC by zooplankton in H. molitrix mesocosms, while grazing by protozoa (heterotrophic nanoflagellates, ciliates) became the major way to regulate BCC. Total bacterioplankton abundances were significantly higher in C. carpio mesocosms because of high nutrient concentration and suspended solids. Our study provided insights into the relationship between fish and bacterioplankton at species level, leading to a deep understanding of the function of the microbial loop and the aquatic ecosystem.

PHASEGO: A toolkit for automatic calculation and plot of phase diagram

NASA Astrophysics Data System (ADS)

Liu, Zhong-Li

2015-06-01

The PHASEGO package extracts the Helmholtz free energy from the phonon density of states obtained by the first-principles calculations. With the help of equation of states fitting, it reduces the Gibbs free energy as a function of pressure/temperature at fixed temperature/pressure. Based on the quasi-harmonic approximation (QHA), it calculates the possible phase boundaries among all the structures of interest and finally plots the phase diagram automatically. For the single phase analysis, PHASEGO can numerically derive many properties, such as the thermal expansion coefficients, the bulk moduli, the heat capacities, the thermal pressures, the Hugoniot pressure-volume-temperature relations, the Grüneisen parameters, and the Debye temperatures. In order to check its ability of phase transition analysis, I present here two examples: semiconductor GaN and metallic Fe. In the case of GaN, PHASEGO automatically determined and plotted the phase boundaries among the provided zinc blende (ZB), wurtzite (WZ) and rocksalt (RS) structures. In the case of Fe, the results indicate that at high temperature the electronic thermal excitation free energy corrections considerably alter the phase boundaries among the body-centered cubic (bcc), face-centered cubic (fcc) and hexagonal close-packed (hcp) structures.

Modelling of Surfaces. Part 1: Monatomic Metallic Surfaces Using Equivalent Crystal Theory

NASA Technical Reports Server (NTRS)

Bozzolo, Guillermo; Ferrante, John; Rodriguez, Agustin M.

1994-01-01

We present a detailed description of equivalent crystal theory focusing on its application to the study of surface structure. While the emphasis is in the structure of the algorithm and its computational aspects, we also present a comprehensive discussion on the calculation of surface energies of metallic systems with equivalent crystal theory and other approaches. Our results are compared to experiment and other semiempirical as well as first-principles calculations for a variety of fcc and bcc metals.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wan, Li; Thompson, Gregory, E-mail: gthompson@eng.ua.edu

A series of 40–2 nm bilayer spacing Ti/Fe multilayers were sputter-deposited. As the length scale of individual Ti layers equaled to 2 nm, Ti phase transforms from a hexagonal close packed (hcp)-to-body centered cubic (bcc) crystal structures for equal layer thicknesses in Ti/Fe multilayers. Further equal reductions in bilayer spacing to less than 1 nm resulted in an additional transformation from a crystalline to amorphous structure. Atom probe tomography reveals significant intermixing between layers which contributes to the observed phase transformations. Real-time, intrinsic growth stress measurements were also performed to relate the adatom mobility to these phase transformations. For the hcp Ti/bcc Femore » multilayers of equivalent volume fractions, the multilayers undergo an overall tensile stress state to a compressive stress state with decreasing bilayer thickness for the multilayers. When the above phase transformations occurred, a modest reduction in the overall compressive stress of the multilayer was noted. Depending on the Fe thickness, the Ti growth was observed to be a tensile to compressive growth change to a purely compressive growth for thinner bilayer spacing. Fe retained a tensile growth stress regardless of the bilayer spacing studied.« less

Effect of local structures on crystallization in deeply undercooled metallic glass-forming liquids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, S. Q.; Li, M. Z., E-mail: maozhili@ruc.edu.cn; Wu, Z. W.

2016-04-21

The crystallization mechanism in deeply undercooled ZrCu metallic glass-forming liquids was investigated via molecular dynamics simulations. It was found that the crystallization process is mainly controlled by the growth of crystal nuclei formed by the BCC-like atomic clusters, consistent with experimental speculations. The crystallization rate is found to relate to the number of growing crystal nuclei in the crystallization process. The crystallization rate in systems with more crystal nuclei is significantly hindered by the larger surface fractions of crystal nuclei and their different crystalline orientations. It is further revealed that in the crystallization in deeply undercooled regions, the BCC-like crystalmore » nuclei are formed from the inside of the precursors formed by the FCC-like atomic clusters, and growing at the expense of the precursors. Meanwhile, the precursors are expanding at the expense of the outside atomic clusters. This process is consistent with the so-called Ostwald step rule. The atomic structures of metallic glasses are found to have significant impact on the subsequent crystallization process. In the Zr{sub 85}Cu{sub 15} system, the stronger spatial correlation of Cu atoms could hinder the crystallization processes in deeply undercooled regions.« less

Development of an interatomic potential for the simulation of defects, plasticity, and phase transformations in titanium

DOE PAGES

Mendelev, M. I.; Underwood, T. L.; Ackland, G. J.

2016-10-17

New interatomic potentials describing defects, plasticity, and high temperature phase transitions for Ti are presented. Fitting the martensitic hcp-bcc phase transformation temperature requires an efficient and accurate method to determine it. We apply a molecular dynamics method based on determination of the melting temperature of competing solid phases, and Gibbs-Helmholtz integration, and a lattice-switch Monte Carlo method: these agree on the hcp-bcc transformation temperatures to within 2 K. We were able to develop embedded atom potentials which give a good fit to either low or high temperature data, but not both. The first developed potential (Ti1) reproduces the hcp-bcc transformationmore » and melting temperatures and is suitable for the simulation of phase transitions and bcc Ti. Two other potentials (Ti2 and Ti3) correctly describe defect properties and can be used to simulate plasticity or radiation damage in hcp Ti. The fact that a single embedded atom method potential cannot describe both low and high temperature phases may be attributed to neglect of electronic degrees of freedom, notably bcc has a much higher electronic entropy. As a result, a temperature-dependent potential obtained from the combination of potentials Ti1 and Ti2 may be used to simulate Ti properties at any temperature.« less

Direct connection of the nucleus reticularis gigantocellularis neurons with neck motoneurons in cats.

PubMed

Sasaki, S

1999-10-01

Functional connections of single reticulospinal neurons (RSNs) in the nucleus reticularis gigantocellularis (NRG) with ipsilateral dorsal neck motoneurons were examined with the spike-triggered averaging technique. Extracellular spikes of single NRG-RSNs activated antidromically from the C6, but not from the L1 segment (C-RSNs) were used as the trigger. These neurons were monosynaptically activated from the superior colliculus and the cerebral peduncle. Single-RSN PSPs were recorded in 43 dorsal neck motoneurons [biventer cervicis and complexus (BCC) and splenius (SPL)] for 21 NRG-RSNs and 135 motoneurons tested. All synaptic potentials were EPSPs, and most of their latencies, measured from the triggering spikes, were 0.8-1.5 ms, which is in a monosynaptic range. The amplitudes of single-RSN EPSPs were 10-360 microV. Spike-triggered averaging revealed single-RSN EPSPs in multiple motoneurons of the same species (SPL or BCC), their locations extending up to nearly 1 mm rostrocaudally. Synaptic connections of single RSNs with both SPL and BCC motoneurons were also found with some predominance for one of them. The results provide direct evidence that NRG-RSNs make monosynaptic excitatory connections with SPL and BCC motoneurons. It appears that some NRG-RSNs connect predominantly with SPL motoneurons and others with BCC motoneurons.

Impact of various color LED flashlights and different lighting source to skin distances on the manual and the computer-aided detection of basal cell carcinoma borders.

PubMed

Bakht, Mohamadreza K; Pouladian, Majid; Mofrad, Farshid B; Honarpisheh, Hamid

2014-02-01

Quantitative analysis based on digital skin image has been proven to be helpful in dermatology. Moreover, the borders of the basal cell carcinoma (BCC) lesions have been challenging borders for the automatic detection methods. In this work, a computer-aided dermatoscopy system was proposed to enhance the clinical detection of BCC lesion borders. Fifty cases of BCC were selected and 2000 pictures were taken. The lesion images data were obtained with eight colors of flashlights and in five different lighting source to skin distances (SSDs). Then, the image-processing techniques were used for automatic detection of lesion borders. Further, the dermatologists marked the lesions on the obtained photos. Considerable differences between the obtained values referring to the photographs that were taken at super blue and aqua green color lighting were observed for most of the BCC borders. It was observed that by changing the SSD, an optimum distance could be found where that the accuracy of the detection reaches to a maximum value. This study clearly indicates that by changing SSD and lighting color, manual and automatic detection of BCC lesions borders can be enhanced. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Statistical theory of diffusion in concentrated bcc and fcc alloys and concentration dependencies of diffusion coefficients in bcc alloys FeCu, FeMn, FeNi, and FeCr

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vaks, V. G.; Khromov, K. Yu., E-mail: khromov-ky@nrcki.ru; Pankratov, I. R.

2016-07-15

The statistical theory of diffusion in concentrated bcc and fcc alloys with arbitrary pairwise interatomic interactions based on the master equation approach is developed. Vacancy–atom correlations are described using both the second-shell-jump and the nearest-neighbor-jump approximations which are shown to be usually sufficiently accurate. General expressions for Onsager coefficients in terms of microscopic interatomic interactions and some statistical averages are given. Both the analytical kinetic mean-field and the Monte Carlo methods for finding these averages are described. The theory developed is used to describe sharp concentration dependencies of diffusion coefficients in several iron-based alloy systems. For the bcc alloys FeCu,more » FeMn, and FeNi, we predict the notable increase of the iron self-diffusion coefficient with solute concentration c, up to several times, even though values of c possible for these alloys do not exceed some percent. For the bcc alloys FeCr at high temperatures T ≳ 1400 K, we show that the very strong and peculiar concentration dependencies of both tracer and chemical diffusion coefficients observed in these alloys can be naturally explained by the theory, without invoking exotic models discussed earlier.« less

Expression of matrix metalloproteinase-13 and Ki-67 in nonmelanoma skin cancer in xeroderma pigmentosum and non-xeroderma pigmentosum.

PubMed

El-Hawary, Amira K; Yassin, Eman; Khater, Ashraf; Abdelgaber, Soheir

2013-02-01

Xeroderma pigmentosum (XP) is a heterogenous group of genetic diseases in which basal cell carcinoma (BCC) is the most common nonmelanoma skin cancer (NMSC) followed by squamous cell carcinoma (SCC). The aim of this study was to investigate the expression of matrix metalloproteinase (MMP)-13 and Ki-67 in SCC and BCC from patients with and without XP to elucidate their roles in the pathogenesis of these highly aggressive tumors in patients with XP. Immunolabeling using MMP-13 and Ki-67 antibodies was performed on tissue sections derived from skin biopsies of SCC and BCC of 15 patients with XP and 40 non-XP patients. There was no significant difference between XP and non-XP patients as regards MMP-13 expression by epithelial and stromal cells of SCC or BCC. Ki-67 expression in SCC and BCC of patients with XP was significantly higher than in non-XP patients. We concluded that the higher expression of Ki-67 in NMSC of patients with XP than of non-XP patients may reflect the growth and invasive capacity of these tumors in patients with XP. MMP-13 is expressed by tumor epithelial cells, stromal and inflammatory cells of NMSC of both XP and non-XP patients.

Boron isotope-based seasonal paleo-pH reconstruction for the Southeast Atlantic - A multispecies approach using habitat preference of planktonic foraminifera

NASA Astrophysics Data System (ADS)

Raitzsch, Markus; Bijma, Jelle; Benthien, Albert; Richter, Klaus-Uwe; Steinhoefel, Grit; Kučera, Michal

2018-04-01

The boron isotopic composition of planktonic foraminiferal shell calcite (δ11BCc) provides valuable information on the pH of ambient water at the time of calcification. Hence, δ11BCc of fossil surface-dwelling planktonic foraminifera can be used to reconstruct ancient aqueous pCO2 if information on a second carbonate system parameter, temperature and salinity is available. However, pH and pCO2 of surface waters may vary seasonally, largely due to changes in temperature, DIC, and alkalinity. As also the shell fluxes of planktonic foraminifera show species-specific seasonal patterns that are linked to intra-annual changes in temperature, it is obvious that δ11BCc of a certain species reflects the pH and thus pCO2 biased towards a specific time period within a year. This is important to consider for the interpretation of fossil δ11BCc records that may mirror seasonal pH signals. Here we present new Multi-Collector Inductively Coupled Mass Spectrometry (MC-ICPMS) δ11BCc coretop data for the planktonic foraminifera species Globigerina bulloides, Globigerinoides ruber, Trilobatus sacculifer and Orbulina universa and compare them with δ11Bborate derived from seasonally resolved carbonate system parameters. We show that the inferred season-adjusted δ11BCc /δ11Bborate relationships are similar to existing calibrations and can be combined with published δ11BCc field and culture data to augment paleo-pH calibrations. To test the applicability of these calibrations, we used a core drilled on the Walvis Ridge in the Southeast Atlantic spanning the last 330,000 years to reconstruct changes in surface-water pCO2. The reconstruction based on G. bulloides, which reflects the austral spring season, was shown to yield values that closely resemble the Vostok ice-core data indicating that surface-water pCO2 was close to equilibrium with the atmosphere during the cooler spring season. In contrast, pCO2 estimated from δ11BCc of O. universa, T. sacculifer and G. ruber that predominantly lived during the warmer seasons, exhibits up to ∼50 ppmv higher values than the Vostok ice-core data. This is probably due to the higher austral summer and fall temperatures, as shown by Mg/Ca to be on average ∼4 °C higher than during the cooler spring season, accounting for an increase in pCO2 of ∼4% per 1 °C. Our results demonstrate that paleo-pH estimates based on δ11BCc contain a significant seasonal signal reflecting the habitat preference of the recording foraminifera species.

Diverse assembly behavior in colloidal Platonic polyhedral sphere clusters

NASA Astrophysics Data System (ADS)

Marson, Ryan; Teich, Erin; Dshemuchadse, Julia; Glotzer, Sharon; Larson, Ronald

We simulate the self-assembly of colloidal ``polyhedral sphere clusters (PSCs)'', which consist of equal-sized spheres placed at the vertices of a polyhedron such that they just touch along each edge. These colloidal building blocks have recently been experimentally fabricated; here we predict crystal structures that would appear in the phase diagram of resulting particle assemblies. We use Brownian dynamics (BD) simulations of rigid body clusters performed in the open-source GPU-based HOOMD-Blue particle simulation package to show the assembly behavior of the 5 Platonic PSCs. The simulations contain as many as 4096 individual polyhedra, across over 30 different densities per cluster geometry, with some ordered phases possessing unit cells with 20 or more particles. We observe the formation of not only traditional cubic structures such as BCC and FCC, but also more complex phases having structure symmetries with Pearson symbols - hP7, cP20, cI2, mP6, and hR3. The observations reported here will serve as a guide for future colloidal assembly experiments using an expanded library of PSCs, consisting of other regular and irregular polyhedra, allowing researchers to target specific arrangements of ``halo'' and ``core'' particles for technologically relevant applications including photonics and structural color.

Consensus recommendations for the treatment of basal cell carcinomas in Gorlin syndrome with topical methylaminolaevulinate-photodynamic therapy.

PubMed

Basset-Seguin, N; Bissonnette, R; Girard, C; Haedersdal, M; Lear, J T; Paul, C; Piaserico, S

2014-05-01

Patients with Gorlin syndrome develop multiple basal cell carcinomas (BCC), for which treatment is often difficult. Methylaminolevulinate-photodynamic therapy (MAL-PDT) is approved for the treatment of superficial and nodular BCCs in Canada and several European countries. To establish consensus recommendations for the use of MAL-PDT in patients with Gorlin syndrome. The Gorlin consensus panel was comprised of 7 dermatologists who had treated a total of 83 patients with Gorlin syndrome using MAL-PDT. Consensus was developed based on the personal experience of the expert and results of literature review (on PUBMED using the keywords 'MAL' and 'PDT' and 'Gorlin' or 'naevoid basal cell carcinoma syndrome'). Consensus was reached among the experts and the literature review identified 9 relevant reports. The experts considered MAL-PDT a generally effective and safe therapy for treatment of BCC in Gorlin syndrome. For superficial BCC (sBCC), all sizes can be treated, and in nodular BCC (nBCC), better efficacy can be achieved in thinner lesions (<2 mm in thickness). MAL-PDT treatment schedule should be performed according to labelling although in individual cases, it may be adapted and performed on a monthly basis based on clinical assessment. Follow-up should be related to frequency of recurrence, and severity, number and location of lesions. Multiple lesions and large areas may be treated during the same session; however, adequate pain management should be considered. MAL-PDT is safe and effective in patients with Gorlin syndrome. Utilization of these recommendations may improve efficacy and clearance rates in this population. © 2013 The Authors Journal of the European Academy of Dermatology and Venereology © 2013 European Academy of Dermatology and Venereology.

Immunolocalization of glioma-associated oncogene homolog 1 in non melanoma skin cancer.

PubMed

Bakry, Ola Ahmed; Samaka, Rehab Monir; Shoeib, Mohamed Abdel Moneim; Megahed, Doaa Mohamed

2015-04-01

Glioma-associated oncogene homolog (GLI)1 is involved in controlling cell proliferation and angiogenesis. The aim of this work was to explore its possible role in non-melanoma skin cancer pathogenesis through its immunohistochemical (IHC) expression in skin biopsies of these diseases and correlating this expression with the clinico-pathological parameters of the studied cases. Seventy-six cutaneous specimens were studied; 30 cases with basal cell carcinoma (BCC), 30 cases with squamous cell carcinoma (SCC) and 16 normal skin samples, from age- and gender-matched subjects, as a control group. GLI1 was expressed in all BCC cases and in 60% of SCC cases. All SCC cases showed cytoplasmic, while 70% of BCC cases showed nucleocytoplasmic immunoreactivity. It was over expressed in BCC and SCC compared to normal skin (p = 0.01 and 0.0006, respectively). Higher Histo (H) score in BCC cases was significantly associated with female gender (p = 0.04), multiple lesions, desmoplastic stromal reaction and stromal angiogenesis (p < 0.001 for all). Higher H score in SCC cases was significantly associated with scalp location, nodular type, recurrent lesions, high tumor grade, lymphovascular invasion (p = 0.004 for all), inflammatory stromal reaction (p = 0.01), lymph node involvement and absence of calcification (p = 0.001 for both). In conclusion, GLI1 may play a role in BCC pathogenesis through its role in cell proliferation, migration, and angiogenesis. Its upregulation and cytoplasmic localization in SCC may suggest that its role in tumor pathogenesis is through mechanisms other than Hedgehog pathway activation. Further studies are needed to clarify the exact molecular basis of its oncogenic action.

Key role for efflux in the preservative susceptibility and adaptive resistance of Burkholderia cepacia complex bacteria.

PubMed

Rushton, Laura; Sass, Andrea; Baldwin, Adam; Dowson, Christopher G; Donoghue, Denise; Mahenthiralingam, Eshwar

2013-07-01

Bacteria from the Burkholderia cepacia complex (Bcc) are encountered as industrial contaminants, and little is known about the species involved or their mechanisms of preservative resistance. Multilocus sequence typing (MLST) revealed that multiple Bcc species may cause contamination, with B. lata (n = 17) and B. cenocepacia (n = 11) dominant within the collection examined. At the strain level, 11 of the 31 industrial sequence types identified had also been recovered from either natural environments or clinical infections. Minimal inhibitory (MIC) and minimum bactericidal (MBC) preservative concentrations varied across 83 selected Bcc strains, with industrial strains demonstrating increased tolerance for dimethylol dimethyl hydantoin (DMDMH). Benzisothiazolinone (BIT), DMDMH, methylisothiazolinone (MIT), a blend of 3:1 methylisothiazolinone-chloromethylisothiazolinone (M-CMIT), methyl paraben (MP), and phenoxyethanol (PH), were all effective anti-Bcc preservatives; benzethonium chloride (BC) and sodium benzoate (SB) were least effective. Since B. lata was the dominant industrial Bcc species, the type strain, 383(T) (LMG 22485(T)), was used to study preservative tolerance. Strain 383 developed stable preservative tolerance for M-CMIT, MIT, BIT, and BC, which resulted in preservative cross-resistance and altered antibiotic susceptibility, motility, and biofilm formation. Transcriptomic analysis of the B. lata 383 M-CMIT-adapted strain demonstrated that efflux played a key role in its M-CMIT tolerance and elevated fluoroquinolone resistance. The role of efflux was corroborated using the inhibitor l-Phe-Arg-β-napthylamide, which reduced the MICs of M-CMIT and ciprofloxacin. In summary, intrinsic preservative tolerance and stable adaptive changes, such as enhanced efflux, play a role in the ability of Bcc bacteria to cause industrial contamination.

Key Role for Efflux in the Preservative Susceptibility and Adaptive Resistance of Burkholderia cepacia Complex Bacteria

PubMed Central

Rushton, Laura; Sass, Andrea; Baldwin, Adam; Dowson, Christopher G.; Donoghue, Denise

2013-01-01

Bacteria from the Burkholderia cepacia complex (Bcc) are encountered as industrial contaminants, and little is known about the species involved or their mechanisms of preservative resistance. Multilocus sequence typing (MLST) revealed that multiple Bcc species may cause contamination, with B. lata (n = 17) and B. cenocepacia (n = 11) dominant within the collection examined. At the strain level, 11 of the 31 industrial sequence types identified had also been recovered from either natural environments or clinical infections. Minimal inhibitory (MIC) and minimum bactericidal (MBC) preservative concentrations varied across 83 selected Bcc strains, with industrial strains demonstrating increased tolerance for dimethylol dimethyl hydantoin (DMDMH). Benzisothiazolinone (BIT), DMDMH, methylisothiazolinone (MIT), a blend of 3:1 methylisothiazolinone-chloromethylisothiazolinone (M-CMIT), methyl paraben (MP), and phenoxyethanol (PH), were all effective anti-Bcc preservatives; benzethonium chloride (BC) and sodium benzoate (SB) were least effective. Since B. lata was the dominant industrial Bcc species, the type strain, 383T (LMG 22485T), was used to study preservative tolerance. Strain 383 developed stable preservative tolerance for M-CMIT, MIT, BIT, and BC, which resulted in preservative cross-resistance and altered antibiotic susceptibility, motility, and biofilm formation. Transcriptomic analysis of the B. lata 383 M-CMIT-adapted strain demonstrated that efflux played a key role in its M-CMIT tolerance and elevated fluoroquinolone resistance. The role of efflux was corroborated using the inhibitor l-Phe-Arg-β-napthylamide, which reduced the MICs of M-CMIT and ciprofloxacin. In summary, intrinsic preservative tolerance and stable adaptive changes, such as enhanced efflux, play a role in the ability of Bcc bacteria to cause industrial contamination. PMID:23587949

Favourable results of Mohs micrographic surgery for basal cell carcinoma.

PubMed

Gniadecki, Robert; Glud, Martin; Mortensen, Kia; Bang, Bo; Biskup, Edyta; Omland, Silje Haukali

2015-12-01

Basal cell carcinoma (BCC) is the most common malignant neoplasm with an annual incidence approaching 200/100,000 person-years. Mohs micrographic surgery (MMS) is widely used in North America and in Europe for treatment of BCC. This technique ensures radical tumour removal, sparing of the surrounding healthy skin, and it also offers higher cure rates than standard tumour excision with a predefined margin of healthy skin. The superiority of MMS relies on the fact that the entire (100%) margin of the excised tissue is examined microscopically for residual tumour in contrast to the traditional histopathological examination, in which 2% of the margin is examined. In Denmark, MMS was first introduced by us in 2012. In the present study, we retrospectively included all patients who underwent MMS from May 2012 to June 2015. A total of 231 patients with 263 BCC were included. The mean age was 66.1 years. The most common localisations were the forehead (31.3%), the nose (31.0%) and the cheek (14.7%). Primary BCC comprised 54.0%; the remaining cases were relapses, most frequently after curettage (36.9%), radiotherapy (18.9%) and photodynamic therapy (11.7%). MMS leads to 40% smaller skin defects than standard excisions with 4 or 6 mm margins. Closure of skin defects was achieved by side-to-side closure in 49% and by local flaps in 40%. There were no relapses during the observation time. The safety, cosmetic and functional outcome were excellent. We recommend that MMS be included in the Danish BCC treatment guidelines, especially for high-risk BCC in the face, in line with standard practice in Europe and the United States. none. not relevant.

Temporal and vertical distributions of bacterioplankton at the Gray's Reef National Marine Sanctuary.

PubMed

Lu, Xinxin; Sun, Shulei; Zhang, Yu-Qin; Hollibaugh, James T; Mou, Xiaozhen

2015-02-01

Large spatial scales and long-term shifts of bacterial community composition (BCC) in the open ocean can often be reliably predicted based on the dynamics of physical-chemical variables. The power of abiotic factors in shaping BCC on shorter time scales in shallow estuarine mixing zones is less clear. We examined the diurnal variation in BCC at different water depths in the spring and fall of 2011 at a station in the Gray's Reef National Marine Sanctuary (GRNMS). This site is located in the transition zone between the estuarine plume and continental shelf waters of the South Atlantic Bight. A total of 234,516 pyrotag sequences of bacterial 16S rRNA genes were recovered; they were taxonomically affiliated with >200 families of 23 bacterial phyla. Nonmetric multidimensional scaling analysis revealed significant differences in BCC between spring and fall samples, likely due to seasonality in the concentrations of dissolved organic carbon and nitrate plus nitrite. Within each diurnal sampling, BCC differed significantly by depth only in the spring and differed significantly between day and night only in the fall. The former variation largely tracked changes in light availability, while the latter was most correlated with concentrations of polyamines and chlorophyll a. Our results suggest that at the GRNMS, a coastal mixing zone, diurnal variation in BCC is attributable to the mixing of local and imported bacterioplankton rather than to bacterial growth in response to environmental changes. Our results also indicate that, like members of the Roseobacter clade, SAR11 bacteria may play an important role in processing dissolved organic material in coastal oceans. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Increased caffeine intake is associated with reduced risk of basal cell carcinoma of the skin.

PubMed

Song, Fengju; Qureshi, Abrar A; Han, Jiali

2012-07-01

Studies in animals suggest that caffeine administration helps prevent squamous cell skin cancer development, but there have been limited epidemiologic studies on the association between caffeine consumption and skin cancer risk. Using data from the Nurses' Health Study and the Health Professionals Follow-up Study, we prospectively examined risks of basal cell carcinoma (BCC, 22,786 cases), squamous cell carcinoma (SCC, 1,953 cases), and melanoma (741 cases) in relation to caffeine intake. Cox proportional hazard models were used to calculate relative risks (RR) and 95% confidence intervals (CI). The amount of caffeine intake from all dietary sources was inversely associated with BCC risk. Compared with the lowest quintile, the highest quintile had the lowest risk (RR, 0.82 in women; 95% CI:,0.77-0.86 and RR, 0.87 in men; 95% CI, 0.81-0.94; Ptrend<0.0001 in both). A significant inverse association was also found between caffeinated coffee consumption and BCC risk. Compared with individuals who consumed caffeinated coffee less than 1 cup per month, women who consumed more than 3 cups/d had the lowest risk (RR, 0.79; 95% CI, 0.74-0.85; Ptrend<0.0001) and the RR for men was 0.90 (95% CI, 0.80-1.01; Ptrend=0.003). Caffeine from other dietary sources (tea, cola, and chocolate) was also inversely associated with BCC risk. Decaffeinated coffee consumption was not associated with a similar decrease in BCC risk. In contrast, caffeine intake was not found to be inversely associated with risks of SCC or melanoma. Our findings argue that caffeine intake in men and women is inversely associated with risk of BCC. ©2012 AACR.

Indoor tanning and risk of early-onset basal cell carcinoma

PubMed Central

Ferrucci, Leah M.; Cartmel, Brenda; Molinaro, Annette M.; Leffell, David J.; Bale, Allen E.; Mayne, Susan T.

2011-01-01

Background Despite a rise in incidence of basal cell carcinoma (BCC) among young people and the ubiquity of indoor tanning in this population, few epidemiologic studies have investigated this exposure-disease relationship. Objective Evaluate the association between indoor tanning and early-onset BCC. Methods BCC cases (n=376) and controls with minor benign skin conditions (n=390) under age 40 were identified through Yale Dermatopathology. Participants provided information on ever indoor tanning, age of initiation, frequency, duration, burns while tanning, and type of tanning device during an in-person interview. We calculated odds ratios (OR) and 95% confidence intervals (CI) using multivariate logistic regression with never indoor tanners as the referent group. Results Ever indoor tanning was associated with a 69% increased risk of early-onset BCC (95% CI=1.15-2.48). This association was stronger among women (OR=2.14, 95% CI=1.31-3.47), for multiple BCCs (OR=2.16, 95% CI=1.26-3.70), and for BCCs on the trunk and extremities (OR=2.81, 95% CI=1.57-5.02). Risk increased dose-dependently with years used regular indoor tanning devices (p-trend=0.003), number of overall burns (p-trend=<0.001) and burns to biopsy site (p-trend=<0.001) from indoor tanning. Approximately one-quarter (27%) of early-onset BCCs (or 43% among women) could be prevented if individuals never tanned indoors. Limitations Potential recall bias of indoor tanning by cases and generalizability of the control population suggest replication in other studies is warranted. Conclusions Indoor tanning was a strong risk factor for early-onset BCC, particularly among women. Indoor tanning should continue to be targeted by both policy-based and behavioral interventions, as the impact on BCC-associated morbidity may be substantial. PMID:22153793

Solid state amorphization of metastable Al 0.5TiZrPdCuNi high entropy alloy investigated by high voltage electron microscopy

DOE PAGES

Nagase, Takeshi; Takeuchi, Akira; Amiya, Kenji; ...

2017-07-18

Here, the phase stability of high entropy alloy (HEA), Al 0.5TiZrPdCuNi, under fast electron irradiation was studied by in-situ high voltage electron microscopy (HVEM). The initial phase of this alloy quenched from the melt was dependent on cooling rate. At high cooling rates an amorphous phase was obtained, whereas a body-centered cubic ( b.c.c.) phase were obtained at low cooling rates. By thermal crystallization of the amorphous phase b.c.c. phase nano-crystals were formed. Upon fast electron irradiation solid state amorphization (SSA) was observed in b.c.c. phase regardless of the initial microstructure (i.e., “coarse crystalline structure” or “nano-crystalline structure with grainmore » boundaries as a sink for point defects”). SSA behavior in the Al 0.5TiZrPdCuNi HEAs was investigated by in-situ transmission electron microscopy observations. Because the amorphization is very rarely achieved in a solid solution phase under fast electron irradiation in common metallic materials, this result suggests that the Al 0.5TiZrPdCuNi HEA from other common alloys and the other HEAs. The differences in phase stability against the irradiation between the Al 0.5TiZrPdCuNi HEA and the other HEAs were discussed. This is the first experimental evidence of SSA in HEAs stimulated by fast electron irradiation.« less

Ready or Not: Preparation through Simulation

ERIC Educational Resources Information Center

Spellman, Joy

2008-01-01

Immediately after 9/11, Burlington County College (BCC) realized that the focus of emergency preparedness must change. BCC responded by identifying community needs, developing customized simulation training using high-fidelity human patient simulators and laptop/desktop technology; developing partnerships, and securing outside funding. Over 8,500…

On Weak-BCC-Algebras

PubMed Central

Thomys, Janus; Zhang, Xiaohong

2013-01-01

We describe weak-BCC-algebras (also called BZ-algebras) in which the condition (x∗y)∗z = (x∗z)∗y is satisfied only in the case when elements x, y belong to the same branch. We also characterize ideals, nilradicals, and nilpotent elements of such algebras. PMID:24311983

bcc-iron as a promising new monochromator material for thermal neutrons

NASA Astrophysics Data System (ADS)

Kirscht, Patrick; Sobolev, Oleg; Eckold, Götz

2018-04-01

The development of high-performance neutron monochromators is a long-standing and still actual topic in neutron instrumentation. Due to its high scattering cross section, iron is a particularly interesting material since it offers the possibility to obtain high reflectivities at small wavelength and good resolution. Phase transitions between bcc- and fcc-phases hindered the growth of large and high-quality single crystals in the past and only recently bcc-crystals became commercially available. We have characterized the reflecting properties of as-grown and deformed crystals using γ-rays and thermal neutrons. Absolute reflectivities well above 30% for neutron wavelengths near 1 Å could be obtained that are superior to that of all other existing monochromator materials. Hence, the progress in crystal growth along with the knowledge of directed plastic deformation makes the development of bcc-Fe neutron monochromators feasible. Their application in crystal-monochromator instruments is suitable to increase the useful neutron flux at large energies considerably.

Basal cell carcinoma of the nipple-areola complex.

PubMed

Ferguson, Mark S; Nouraei, S A Reza; Davies, Ben J H; McLean, N R

2009-11-01

Basal cell carcinoma (BCC) of the nipple-areola complex is uncommon. It has been suggested that BCCs in this region behave more aggressively, with a higher potential for distant spread, than in other anatomical sites. To address questions about etiology, behavior, optimal treatment, and prognosis of this entity. A literature search identifying all cases of BCC of the nipple and nipple-areola complex in the English literature from 1893 to 2008. Thirty-four cases of BCC of the nipple, areola, or both were identified, mostly affecting middle-aged men. The majority of patients were treated with tissue-sparing surgery. There was a metastatic rate of 9.1%, and one patient died from the disease (3.0%). The optimal treatment of this condition should be local excision, but patients with this condition should be followed up for primary site recurrence and axillary metastasis, because there is greater incidence than with BCC at other anatomical sites. Furthermore, proven axillary metastasis should be surgically treated.

Alcohol consumption and risk of cutaneous basal cell carcinoma in women and men: 3 prospective cohort studies12

PubMed Central

Wu, Shaowei; Li, Wen-Qing; Qureshi, Abrar A; Cho, Eunyoung

2015-01-01

Background: Alcohol consumption has been associated with an increased prevalence of sunburn, which is an established skin cancer risk factor. Objective: We investigated whether alcohol consumption is associated with risk of cutaneous basal cell carcinoma (BCC). Design: We conducted a prospective analysis on alcohol consumption and risk of BCC on the basis of data from 167,765 women in the NHS (Nurses’ Health Study) (1984–2010) and NHS II (1991–2011) and 43,697 men in the Health Professionals Follow-Up Study (1986–2010). Alcohol intake was repeatedly assessed every 2–4 y over the follow-up period. HRs and 95% CIs for BCC in association with alcohol intake were computed with the use of Cox proportional hazards models with adjustment for sun exposure and other skin cancer risk factors. Results: A total of 28,951 incident BCC cases were documented over 3.74 million person-years of follow-up. Increased alcohol intake was associated with increased BCC risk in both women and men (both P-trend < 0.0001). Pooled multivariable-adjusted HRs over increasing cumulative averaged alcohol intake categories were 1.00 (reference) for nondrinkers, 1.13 (95% CI: 1.06, 1.20) for 0.1–9.9 g/d, 1.24 (95% CI: 1.14, 1.35) for 10.0–19.9 g/d, 1.27 (95% CI: 1.20, 1.35) for 20.0–29.9 g/d, and 1.22 (95% CI: 1.15, 1.30) for ≥30.0 g/d (P-trend < 0.0001, P-heterogeneity by study = 0.10 ). The association remained consistent when we used alcohol intakes over different latency periods (0–4, 4–8, 8–12, and 12–16 y) as exposures and over categories of sun exposure–related factors. In the individual alcoholic beverages, white wine and liquor were positively associated with BCC risk. Conclusion: Alcohol consumption is associated with increased risk of cutaneous BCC in both women and men. PMID:26423390

Improved fertility in gilts and sows after artificial insemination of frozen-thawed boar semen by supplementation of semen extender with caffeine and CaCl2.

PubMed

Yamaguchi, Shoichiro; Funahashi, Hiroaki; Murakami, Tetsuya

2009-12-01

Supplementation of semen extender with caffeine and CaCl(2) for artificial insemination (AI) of fresh spermatozoa has been demonstrated to reduce recruitment of uterine polymorphonuclear leukocytes (PMNs) and the activity of phagocytosis. Here, we determined if addition of caffeine and CaCl(2) to semen extender improves the fertility of frozen-thawed boar semen. In experiment 1, gilts were cervically inseminated twice with frozen-thawed boar spermatozoa (25 x 10(8) cells per dose) suspended in Modena solution (n=7) or modified Beltsville Thawing Solution supplemented with caffeine and CaCl(2) (BCC, n=7). The gilts were slaughtered 4 h later, and their oviducts and uterine horns plus the body of the uterus were flushed to recover PMNs and non-phagocytosed spermatozoa. There was no difference in the total number of uterine PMNs between gilts inseminated with Modena solution and those inseminated with BCC (3.8 x 10(8) vs. 1.5 x 10(8) cells, respectively); however, the total number of uterine spermatozoa was higher when gilts were inseminated with BCC (40.6 x 10(6) cells) compared with those inseminated with Modena solution (1.4 x 10(6) cells, P<0.05). In experiment 2, gilts and sows were subjected to intrauterine insemination twice with frozen-thawed spermatozoa suspended (25 x 10(8) sperm per dose) in Modena (n=21) or BCC (n=21). The overall pregnancy and farrowing rates were higher in females inseminated with BCC (71.4 and 61.9%, respectively) compared with those inseminated with Modena solution (38.1 and 28.6%, respectively, P<0.05). However, no significant difference in litter size of piglets was observed between treatments (7.2 +/- 1.6 piglets for Modena solution vs. 8.2 +/- 0.9 piglets for BCC solution). In conclusion, we demonstrated that use of BCC solution for frozen-thawed boar semen produced better pregnancy and farrowing rates following AI than Modena solution, probably by reducing the phagocytosis of spermatozoa.

The Concerted Action of Type 2 and Type 3 Deiodinases Regulates the Cell Cycle and Survival of Basal Cell Carcinoma Cells.

PubMed

Miro, Caterina; Ambrosio, Raffaele; De Stefano, Maria Angela; Di Girolamo, Daniela; Di Cicco, Emery; Cicatiello, Annunziata Gaetana; Mancino, Giuseppina; Porcelli, Tommaso; Raia, Maddalena; Del Vecchio, Luigi; Salvatore, Domenico; Dentice, Monica

2017-04-01

Thyroid hormones (THs) mediate pleiotropic cellular processes involved in metabolism, cellular proliferation, and differentiation. The intracellular hormonal environment can be tailored by the type 1 and 2 deiodinase enzymes D2 and D3, which catalyze TH activation and inactivation respectively. In many cellular systems, THs exert well-documented stimulatory or inhibitory effects on cell proliferation; however, the molecular mechanisms by which they control rates of cell cycle progression have not yet been entirely clarified. We previously showed that D3 depletion or TH treatment influences the proliferation and survival of basal cell carcinoma (BCC) cells. Surprisingly, we also found that BCC cells express not only sustained levels of D3 but also robust levels of D2. The aim of the present study was to dissect the contribution of D2 to TH metabolism in the BCC context, and to identify the molecular changes associated with cell proliferation and survival induced by TH and mediated by D2 and D3. We used the CRISPR/Cas9 technology to genetically deplete D2 and D3 in BCC cells and studied the consequences of depletion on cell cycle progression and on cell death. Cell cycle progression was analyzed by fluorescence activated cell sorting analysis of synchronized cells, and the apoptosis rate by annexin V incorporation. Mechanistic investigations revealed that D2 inactivation accelerates cell cycle progression thereby enhancing the proportion of S-phase cells and cyclin D1 expression. Conversely, D3 mutagenesis drastically suppressed cell proliferation and enhanced apoptosis of BCC cells. Furthermore, the basal apoptotic rate was oppositely regulated in D2- and D3-depleted cells. Our results indicate that BCC cells constitute an example in which the TH signal is finely tuned by the concerted expression of opposite-acting deiodinases. The dual regulation of D2 and D3 expression plays a critical role in cell cycle progression and cell death by influencing cyclin D1-mediated entry into the G1-S phase. These findings reinforce the concept that TH is a potential therapeutic target in human BCC.

Basal cell carcinoma in farmers: an occupation group at high risk.

PubMed

Szewczyk, Mateusz; Pazdrowski, Jakub; Golusiński, Paweł; Dańczak-Pazdrowska, Aleksandra; Łuczewski, Łukasz; Marszałek, Sławomir; Majchrzak, Ewa; Golusiński, Wojciech

2016-04-01

Skin cancer is the most commonly diagnosed cancer type worldwide, and 80 % of skin cancers are basal cell carcinoma (BCC). The main risk factor for developing BCC is exposure to ultraviolet radiation (UVR), particularly high-dose exposure at a young age. Outdoor workers, particularly farmers, are at high risk of developing BCC. However, studies of BCC in this population are scant. To comprehensively evaluate all cases of BCC of the head and neck region treated during the years 2007-2013 at our hospital in Poland, and to compare the tumour characteristics in farmers to non-farmers. Retrospective analysis of 312 patients treated for head and neck BCC during the study period (2007-2013). Most patients (198 cases; 63 %) were males, with 114 females (37 %). Median age was 73 years (range 32-96 years). The most common tumour location was the nose and cheek (114 pts; 37 %) followed by the auricle (82 pts; 26 %), lips (54 pts; 18 %), scalp (26 pts; 8 %), and eye (36 pts; 12 %). The most common disease stage on presentation was stage T2 (104 pts, 33 %), followed by stage T1 (79 pts; 25 %), stage T3 (89 pts; 28 %), and stage T4 (40 pts; 14 %). By occupation, farmers accounted for 33 % of all patients (102 of 312 pts). The most common tumour localisations in the farmer subgroup were the nose and cheek (50 pts; 49 %; p < 0.001; odds ratio [OR] 2.19; 95 % confidence interval [CI] 1.35-3.57), followed by the auricle (32 pts; 31 %), scalp (16 pts; 16 %), ocular region (3 pts; 3 %), and lips (1 pt; 1 %). Patients in the farmer group were significantly younger than non-farmers (62 vs. 73 years; p < 0.001; OR 0.90, 95 % CI 0.88-0.93). Farmers were significantly more likely to present disease recurrence (27 vs. 12 % of cases; p < 0.001; OR 5.94; 95 % CI 2.86-12.33). The results highlight the increased incidence and risk of recurrence of BCC in farmers. It is therefore necessary to consider enhancing educational programmes and other preventative measures in this occupational group and to evaluate the effectiveness of such programmes.

Thermodynamic stability and structural properties of cluster crystals formed by amphiphilic dendrimers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lenz, Dominic A.; Likos, Christos N.; Blaak, Ronald

We pursue the goal of finding real-world examples of macromolecular aggregates that form cluster crystals, which have been predicted on the basis of coarse-grained, ultrasoft pair potentials belonging to a particular mathematical class [B. M. Mladek et al., Phys. Rev. Lett. 46, 045701 (2006)]. For this purpose, we examine in detail the phase behavior and structural properties of model amphiphilic dendrimers of the second generation by means of monomer-resolved computer simulations. On augmenting the density of these systems, a fluid comprised of clusters that contain several overlapping and penetrating macromolecules is spontaneously formed. Upon further compression of the system, amore » transition to multi-occupancy crystals takes place, the thermodynamic stability of which is demonstrated by means of free-energy calculations, and where the FCC is preferred over the BCC-phase. Contrary to predictions for coarse-grained theoretical models in which the particles interact exclusively by effective pair potentials, the internal degrees of freedom of these molecules cause the lattice constant to be density-dependent. Furthermore, the mechanical stability of monodisperse BCC and FCC cluster crystals is restricted to a bounded region in the plane of cluster occupation number versus density. The structural properties of the dendrimers in the dense crystals, including their overall sizes and the distribution of monomers are also thoroughly analyzed.« less

Analytical modeling of fire growth on fire-resistive wood-based materials with changing conditions

Treesearch

Mark A. Dietenberger

2006-01-01

Our analytical model of fire growth for the ASTM E 84 tunnel, which simultaneously predicts heat release rate, flame-over area, and pyrolysis area as functions of time for constant conditions, was documented in the 2001 BCC Symposium for different treated wood materials. The model was extended to predict ignition and fire growth on exterior fire-resistive structures...

X-ray diffraction of molybdenum under shock compression to 450 GPa

DOE PAGES

Wang, Jue; Coppari, Federica; Smith, Raymond F.; ...

2015-11-20

Molybdenum (Mo) is a body-centered-cubic (bcc) transition metal that has widespread technological applications. Although the bcc transition elements are used as test cases for understanding the behavior of metals under extreme conditions, the melting curves and phase transitions of these elements have been the subject of stark disagreements in recent years. Here we use x-ray diffraction to examine the phase stability and melting behavior of Mo under shock loading to 450 GPa. The bcc phase of Mo remains stable along the Hugoniot until 380 GPa. Here, our results do not support previous claims of a shallow melting curve for molybdenum.

In-situ laser ultrasonic measurement of the hcp to bcc transformation in commercially pure titanium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shinbine, A., E-mail: alyssa.shinbine@gmail.com; Garcin, T.; Sinclair, C.

2016-07-15

Using a novel in-situ laser ultrasonic technique, the evolution of longitudinal velocity was used to measure the α − β transformation during cyclic heating and cooling in commercially pure titanium. In order to quantify the transformation kinetics, it is shown that changes in texture can not be ignored. This is particularly important in the case of titanium where significant grain growth occurs in the β-phase leading to the ultrasonic wave sampling a decreasing number of grains on each thermal treatment cycle. Electron backscatter diffraction measurements made postmortem in the region where the ultrasonic pulse traveled were used to obtain anmore » estimate of such local texture and grain size changes. An analysis technique for including the anisotropy of wave velocity depending on local texture is presented and shown to give self consistent results for the transformation kinetics. - Highlights: • Laser ultrasound and EBSD interpret the hcp/bcc phase transformation in cp-Ti. • Grain growth and texture produced variation in velocity during similar treatments. • Texture was deconvoluted from phase addition to obtain transformation kinetics.« less

Crystal-melt interface mobility in bcc Fe: Linking molecular dynamics to phase-field and phase-field crystal modeling

NASA Astrophysics Data System (ADS)

Guerdane, M.; Berghoff, M.

2018-04-01

By combining molecular dynamics (MD) simulations with phase-field (PF) and phase-field crystal (PFC) modeling we study collision-controlled growth kinetics from the melt for pure Fe. The MD/PF comparison shows, on the one hand, that the PF model can be properly designed to reproduce quantitatively different aspects of the growth kinetics and anisotropy of planar and curved solid-liquid interfaces. On the other hand, this comparison demonstrates the ability of classical MD simulations to predict morphology and dynamics of moving curved interfaces up to a length scale of about 0.15 μ m . After mapping the MD model to the PF one, the latter permits to analyze the separate contribution of different anisotropies to the interface morphology. The MD/PFC agreement regarding the growth anisotropy and morphology extends the trend already observed for the here used PFC model in describing structural and elastic properties of bcc Fe.

Dermoscopy-pathology relationship in seborrheic keratosis.

PubMed

Minagawa, Akane

2017-05-01

Making a definitive diagnosis of seborrheic keratosis (SK) can be challenging for the naked eye due to its wide variation in clinical features. Fortunately, however, most cases of SK exhibit the typical dermoscopic findings of fissures and ridges, hairpin vessels with white halo, comedo-like openings, and milia-like cysts, all of which are helpful to distinguish SK from melanoma, melanocytic nevus, squamous cell carcinoma, basal cell carcinoma (BCC) and other skin tumors. Histopathologically, these dermoscopic characteristics correspond to papillomatous surface of the epidermis, enlarged capillaries of the dermal papillae, pseudohorn cysts in the epidermis opened to the surface of the lesion and intraepidermal cysts, respectively. Clinicians should bear in mind that the clonal type of SK dermoscopically mimics melanoma and BCC by the presence of globule-like structures, while regressing SK exhibits a granular pattern that is similar to the peppering found in melanoma. Furthermore, milia-like cysts alone are insufficient for a conclusive diagnosis of SK because melanoma in rare cases displays cysts along with other SK-like dermoscopic findings. © 2017 Japanese Dermatological Association.

Molecular dynamics study of the interaction between nanoscale interstitial dislocation loops and grain boundaries in BCC iron

NASA Astrophysics Data System (ADS)

Gao, N.; Perez, D.; Lu, G. H.; Wang, Z. G.

2018-01-01

Atomic simulations are used to investigate the interaction between nanoscale interstitial dislocation loops and grain boundaries (GBs), the subsequent evolution of the GBs' structures, and the resulting impact on mechanical properties, in BCC iron. The interaction between loops and GBs - Σ 3 { 111 } and Σ 3 { 112 } - is affected by the angle (θ) between the Burgers vector and the normal to the GB plane, as well as by the distribution of free volume (FV) and stress. Loops can be totally absorbed by Σ 3 { 111 } boundaries, while the interaction with Σ 3 { 112 } boundaries is found to change the Burgers vector and habit plane after absorption, but to otherwise leave the loop intact, resulting in selective absorption. When θ =90o , no absorption occurs in Σ 3 { 112 } . The stress accumulation induced by the absorption affects the local mechanical properties of GBs. In nanocrystalline iron sample, a similar phenomenon is also observed, resulting in rearrangement of GBs and grain growth.

Basal cell carcinoma in young women: an evaluation of the association of tanning bed use and smoking.

PubMed

Boyd, Alan S; Shyr, Yu; King, Lloyd E

2002-05-01

Basal cell carcinomas (BCCs) typically occur in middle-aged to elderly patients but less commonly in younger ones. In our experience, most BCCs seen in patients younger than 40 years are found in women. We evaluated 30 women with biopsy-proven BCC and 30 control patients matched for sex, age, and skin type to determine potential risk factors for this population. Tanning bed visits, pack-years of cigarette smoking, recreational sun exposure, number of blistering sunburns, and use of sunscreens were determined for both groups. Among patients with a BCC, the histologic type of tumor, site of involvement, method of treatment, follow-up period, incidence of recurrence, and presence of actinic keratoses were also evaluated. Patients with a BCC had a statistically greater number of pack years of smoking (P =.045), and a greater percentage of these women had experienced blistering sunburns (P =.028). Although women with a BCC had, on average, almost twice as many tanning salon visits (152.2 vs 83.1), this was not statistically significant. Sunscreen use and amount of recreational ultraviolet light exposure were essentially equal between the two groups. Young women with a BCC are more likely to have a past or current history of cigarette smoking and blistering sunburns. Repeated exposure to tanning beds may also be a contributory factor.

Discriminating model for skin cancer diagnosis in vivo through Raman spectroscopy

NASA Astrophysics Data System (ADS)

Silveira, Fabrício Luiz; Pacheco, Marcos Tadeu T.; Bodanese, Benito; Zângaro, Renato Amaro; Silveira, Landulfo

2013-03-01

This work aimed the development of a discriminating model, using Raman spectroscopy, based on the estimated concentration of biochemical components presented in skin, for in vivo diagnosis. Raman spectra were collected in patients who underwent excision surgery of suspicious lesions at the lesion site and at a normal circumjacent site. It has been estimated the relative amount of selected biochemical compounds presented in skin. The Raman spectra of normal and malignant (basal cell carcinoma - BCC and squamous cell carcinoma - SCC) skin are quite similar, with some spectral differences in the regions of lipids, nucleic acids, and hemoglobin. Some biochemicals showed statistically significant differences among N, BCC and SCC, such as elastin, ceramide, melanin, nucleid acid, actin and phenylalanine. Elastin and ceramide presented significant differences between N and BCC, melanin, DNA and actin presented significant differences between N and BCC and between N and SCC, being melanin and DNA decreased in neoplasias, in contrast with actin, that increased in neoplasias. Concentration of phenylalanine was significantly increased for SCC compared to N and BCC. The relative concentration of melanin, DNA and phenylalanine showed sensitivity, specificity and accuracy of about 81%, 65% and 60%, respectively, using Mahalanobis distance as a discriminator. This model is being incorporated to a Raman system with automated data collection and processing that could be used for a future in vivo, real time discrimination algorithm.

Dermal changes in superficial basal cell carcinoma, melanoma in situ and actinic keratosis and their implications

PubMed Central

Kazlouskaya, Viktoryia; Malhotra, Saurabh; Navarro, Raquel; Wu, Karen Nguyen; Shvartsbeyn, Marianna; Shengli, Chen; Gui, Jiang; Elston, Dirk M.

2018-01-01

Background Basal cell carcinoma (BCC) has a characteristic stroma, but less is known about the dermal characteristics associated with melanoma in situ (MIS) and actinic keratosis (AK). Materials and methods Dermal changes were studied in 301 specimens of AK, BCC and MIS. Subsequently, blinded images of dermal changes from 90 randomly selected cases of those entities were used to assess the predictive value of the dermal changes. Agreement with the final diagnosis was calculated using kappa coefficient (κ). Results Fibromyxoid stroma was present in 82% of BCC cases; fibrous stroma was seen in 25% of BCC, 58% of MIS and 35.6% of AK specimens (p <0.05). A lichenoid inflammatory infiltrate was frequently associated with AK and a perifollicular infiltrate with periadnexal fibrosis with MIS. Blinded evaluation of images of the dermal changes associated with the tumors yielded the correct diagnosis in (54.4, 41.1 and 27.8%; average 41.2%) by the three appraisers. Coefficient of agreement in blinded imaged evaluation with the actual diagnosis was higher in the BCC and MIS compared with AK (κ = 0.37, p = 0.0001; κ = 0.2, p = 0.0005 and κ = −0.06, p = 0.84, respectively). Conclusion Dermal features may be helpful in predicting the correct diagnosis when tumor is not visible. PMID:24117926

The effect of Mn and B on the magnetic and structural properties of nanostructured Fe60Al40 alloys produced by mechanical alloying.

PubMed

Rico, M M; Alcázar, G A Pérez; Zamora, L E; González, C; Greneche, J M

2008-06-01

The effect of Mn and B on the magnetic and structural properties of nanostructured samples of the Fe60Al40 system, prepared by mechanical alloying, was studied by 57Fe Mössbauer spectrometry, X-ray diffraction and magnetic measurements. In the case of the Fe(60-x)Mn(x)Al40 system, 24 h milling time is required to achieve the BCC ternary phase. Different magnetic structures are observed according to the temperature and the Mn content for alloys milled during 48 h: ferromagnetic, antiferromagnetic, spin-glass, reentrant spin-glass and superparamagnetic behavior. They result from the bond randomness behaviour induced by the atomic disorder introduced by the MA process and from the competitive interactions of the Fe-Fe ferromagnetic interactions and the Mn-Mn and Fe-Mn antiferromagnetic interactions and finally the presence of Al atoms acting as dilutors. When B is added in the Fe60Al40 alloy and milled for 12 and 24 hours, two crystalline phases were found: a prevailing FeAl BCC phase and a Fe2B phase type. In addition, one observes an additional contribution attributed to grain boundaries which increases when both milling time and boron composition increase. Finally Mn and B were added to samples of the Fe60Al40 system prepared by mechanical alloying during 12 and 24 hours. Mn content was fixed to 10 at.% and B content varied between 0 and 20 at.%, substituting Al. X-ray patterns show two crystalline phases, the ternary FeMnAl BCC phase, and a (Fe,Mn)2B phase type. The relative proportion of the last phase increases when the B content increases, in addition to changes of the grain size and the lattice parameter. Such behavior was observed for both milling periods. On the other hand, the magnetic hyperfine field distributions show that both phases exhibit chemical disorder, and that the contribution attributed to the grain boundaries is less important when the B content increases. Coercive field values of about 10(2) Oe slightly increase with boron content. Comparison with previous results on FeAIB alloys shows that Mn promotes the structural stability of the nanostructured powders.

On the Structure of Some Pentaerythritol-Related Molecular Crystals with Pseudotetrahedral Molecular Structure. Ordered Structure of 2,2-Bis(bromomethyl)-1,3-propanediol and Orientationally Disordered Structure of 2-Chloromethyl-2-methyl-1,3-dichloropropane; 35Cl NQR

NASA Astrophysics Data System (ADS)

Dou, Shi-qi; Fuess, Hartmut; Strauß, Roman; Weiss, Alarich

1996-06-01

C(CH2Cl)3(CH3), melting point Tm = 291.3 K, shows in the DTA/DSC experiment a phase tran-sition from an orientationally disordered plastic phase I into an ordered phase II at TI ⃗ II = 235.9 K. From 77 K up to TII ⃗ I the 35Cl NQR spectrum is a triplet with (ν in MHz, T=77 K) ν1 = 34.213, ν2 = 34.183, ν3 = 33.786. The 35Cl NQR fade-out temperature Tf = 247 K coincides with TII ⃗ I found from the DSC experiment. The plastic phase of 2-chloromethyl-2-methyl-l,3-propanediol is cubic bcc, Im3m, Z = 2 and the lattice constant increases linearly 755 pm at 235 K to 768 pm at 283 K. In the heating cycle we found (ΔH in kJ/mol): ΔHII ⃗ I = 12.0, ΔSm/R = 1.0. The compound belongs to the group of plastic molecules formed by ellipsoid like distorted tetrahedra and is derived by substitution from methane. The crystal structure of 2,2-bis(bromomethyl)-1,3-propanediol was determined. DTA-DSC show that an orientationally disordered plastic phase does not exist. At room temperature C(CH2Br)2(CH2OH)2 crystallizes monoclinic, space group Cc, Z = 4, a = 628.2 pm, 6 = 2015.5 pm, c = 659.6 pm, β = 94.27°. The molecules interact by intermolecular hydrogen bonds between the OH-groups and by van der Waals forces Br…Br.

Determination of bulk domain structure and magnetization processes in bcc ferromagnetic alloys: Analysis of magnetostriction in F e83G a17

NASA Astrophysics Data System (ADS)

He, Yangkun; Coey, J. M. D.; Schaefer, Rudolf; Jiang, Chengbao

2018-01-01

The ground state of macroscopic samples of magnetically ordered materials is a domain state because of magnetostatic energy or entropy, yet we have limited experimental means for imaging the bulk domain structure and the magnetization process directly. The common methods available reveal the domains at the surface or in electron- or x-ray transparent lamellae, not those in the bulk. The magnetization curve just reflects the vector sum of the moments of all the domains in the sample, but magnetostriction curves are more informative. They are strongly influenced by the domain structure in the unmagnetized state and its evolution during the magnetization process in an applied field. Here we report a method of determining the bulk domain structure in a cubic magnetostrictive material by combining magneto-optic Kerr microscopy with magnetostriction and magnetization measurements on single crystals as a function of applied field. We analyze the magnetostriction of F e83G a17 crystals in terms of a domain structure that is greatly influenced by sample shape and heat treatment. Saturation magnetostriction measurements are used to determine the fraction of domains orientated along the three 〈100 〉 axes in the initial state. Domain wall motion and rotation process have characteristic signatures in the magnetostriction curves, including those associated with the Δ E effect and domain rotation through a 〈110 〉 auxetic direction.

Is nuclear matter a quantum crystal?

NASA Technical Reports Server (NTRS)

Canuto, V.; Chitre, S. M.

1973-01-01

A possible alternative to the ordinary gas-like computation for nuclear matter is investigated under the assumption that the nucleons are arranged in a lattice. BCC, FCC and HCP structures are investigated. Only HCP shows a minimum in the energy vs. density curve with a modest binding energy of -1.5 MeV. The very low density limit is investigated and sensible results are obtained only if the tensor force decreases with the density. A study of the elastic properties indicates that the previous structures are mechanically unstable against shearing stresses.

Stabilizing the body centered cubic crystal in titanium alloys by a nano-scale concentration modulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, H. L.; Shah, S. A. A.; Hao, Y. L.

It is well-known that the body centered cubic (bcc) crystal in titanium alloys reaches its stability limit as the electron-to-atom (e/a) ratio of the alloy drops down to ~4.24. This critical value, however, is much higher than that of a multifunctional bcc type alloy (e/a = 4.15). Here we demonstrate that a nano-scale concentration modulation created by spinodal decomposition is what stabilizes the bcc crystal of the alloy. Aided by such a nano-scale concentration heterogeneity, unexpected properties from its chemically homogeneous counterpart are obtained. This provides a new strategy to design functional titanium alloys by tuning the spinodal decomposition.

Dislocation dynamics: simulation of plastic flow of bcc metals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lassila, D H

This is the final report for the LDRD strategic initiative entitled ''Dislocation Dynamic: Simulation of Plastic Flow of bcc Metals'' (tracking code: 00-SI-011). This report is comprised of 6 individual sections. The first is an executive summary of the project and describes the overall project goal, which is to establish an experimentally validated 3D dislocation dynamics simulation. This first section also gives some information of LLNL's multi-scale modeling efforts associated with the plasticity of bcc metals, and the role of this LDRD project in the multiscale modeling program. The last five sections of this report are journal articles that weremore » produced during the course of the FY-2000 efforts.« less

Exact ab initio transport coefficients in bcc Fe-X (X=Cr, Cu, Mn, Ni, P, Si) dilute alloys

NASA Astrophysics Data System (ADS)

Messina, Luca; Nastar, Maylise; Garnier, Thomas; Domain, Christophe; Olsson, Pär

2014-09-01

Defect-driven diffusion of impurities is the major phenomenon leading to formation of embrittling nanoscopic precipitates in irradiated reactor pressure vessel (RPV) steels. Diffusion depends strongly on the kinetic correlations that may lead to flux coupling between solute atoms and point defects. In this work, flux coupling phenomena such as solute drag by vacancies and radiation-induced segregation at defect sinks are systematically investigated for six bcc iron-based dilute binary alloys, containing Cr, Cu, Mn, Ni, P, and Si impurities, respectively. First, solute-vacancy interactions and migration energies are obtained by means of ab initio calculations; subsequently, self-consistent mean field theory is employed in order to determine the exact Onsager matrix of the alloys. This innovative multiscale approach provides a more complete treatment of the solute-defect interaction than previous multifrequency models. Solute drag is found to be a widespread phenomenon that occurs systematically in ferritic alloys and is enhanced at low temperatures (as for instance RPV operational temperature), as long as an attractive solute-vacancy interaction is present, and that the kinetic modeling of bcc alloys requires the extension of the interaction shell to the second-nearest neighbors. Drag occurs in all alloys except Fe(Cr); the transition from dragging to nondragging regime takes place for the other alloys around (Cu, Mn, Ni) or above (P, Si) the Curie temperature. As far as only the vacancy-mediated solute migration is concerned, Cr depletion at sinks is foreseen by the model, as opposed to the other impurities which are expected to enrich up to no less than 1000 K. The results of this study confirm the current interpretation of the hardening processes in ferritic-martensitic steels under irradiation.

Packing of Russian doll clusters to form a nanometer-scale CsCl-type compound in a Cr–Zn–Sn complex metallic alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, Weiwei; Cava, Robert J.; Miller, Gordon J.

A new cubic complex metallic alloy phase, Cr 22Zn 72Sn 24, with a lattice parameter near 2.5 nm was discovered in crystals grown using a Zn/Sn flux. The structure consists of Russian doll clusters or a 3-d network of Cr-centered icosahedra (shown) with bcc-metal fragments in void spaces.

Packing of Russian doll clusters to form a nanometer-scale CsCl-type compound in a Cr–Zn–Sn complex metallic alloy

DOE PAGES

Xie, Weiwei; Cava, Robert J.; Miller, Gordon J.

2017-07-03

A new cubic complex metallic alloy phase, Cr 22Zn 72Sn 24, with a lattice parameter near 2.5 nm was discovered in crystals grown using a Zn/Sn flux. The structure consists of Russian doll clusters or a 3-d network of Cr-centered icosahedra (shown) with bcc-metal fragments in void spaces.

The Direct Economic Impact of New Jersey's Community Colleges.

ERIC Educational Resources Information Center

Ryan, Gordon Jeremiah

The study described in this report examined the direct economic impact of Brookdale Community College (BCC) on Monmouth County and the economic impact of the state community college system on New Jersey. Chapter 1 reviews the background and significance of economic impact studies; discusses the issue from general, New Jersey, and BCC perspectives;…

Ab initio theory of noble gas atoms in bcc transition metals

DOE PAGES

Jiang, Chao; Zhang, Yongfeng; Gao, Yipeng; ...

2018-01-01

Systematic ab initio calculations based on density functional theory have been performed to gain fundamental understanding of the interactions between noble gas atoms (He, Ne, Ar and Kr) and bcc transition metals in groups 5B (V, Nb and Ta), 6B (Cr, Mo and W) and 8B (Fe).

Numerical study of slip system activity and crystal lattice rotation under wedge nanoindents in tungsten single crystals

NASA Astrophysics Data System (ADS)

Volz, T.; Schwaiger, R.; Wang, J.; Weygand, S. M.

2018-05-01

Tungsten is a promising material for plasma facing components in future nuclear fusion reactors. In the present work, we numerically investigate the deformation behavior of unirradiated tungsten (a body-centered cubic (bcc) single crystal) underneath nanoindents. A finite element (FE) model is presented to simulate wedge indentation. Crystal plasticity finite element (CPFE) simulations were performed for face-centered and body-centered single crystals accounting for the slip system family {110} <111> in the bcc crystal system and the {111} <110> slip family in the fcc system. The 90° wedge indenter was aligned parallel to the [1 ¯01 ]-direction and indented the crystal in the [0 1 ¯0 ]-direction up to a maximum indentation depth of 2 µm. In both, the fcc and bcc single crystals, the activity of slip systems was investigated and compared. Good agreement with the results from former investigations on fcc single crystals was observed. Furthermore, the in-plane lattice rotation in the material underneath an indent was determined and compared for the fcc and bcc single crystals.

Occupational UV-Exposure is a Major Risk Factor for Basal Cell Carcinoma: Results of the Population-Based Case-Control Study FB-181.

PubMed

Schmitt, Jochen; Haufe, Eva; Trautmann, Freya; Schulze, Hans-Joachim; Elsner, Peter; Drexler, Hans; Bauer, Andrea; Letzel, Stephan; John, Swen Malte; Fartasch, Manigé; Brüning, Thomas; Seidler, Andreas; Dugas-Breit, Susanne; Gina, Michal; Weistenhöfer, Wobbeke; Bachmann, Klaus; Bruhn, Ilka; Lang, Berenice Mareen; Bonness, Sonja; Allam, Jean Pierre; Grobe, William; Stange, Thoralf; Westerhausen, Stephan; Knuschke, Peter; Wittlich, Marc; Diepgen, Thomas Ludwig

2018-01-01

The aim of this study was to investigate the role of occupational and nonoccupational ultraviolet (UV)-exposure concerning the development of basal cell carcinoma (BCC). We undertook a population-based multicenter case-control study. Patients with first incident BCC (n = 836) were propensity score matched by age and sex to controls without skin cancer (n = 836). Sociodemographic characteristics, clinical characteristics, and lifetime UV-exposure were assessed by trained investigators. The differential estimation of occupational and nonoccupational UV-exposure dosages was based on validated instruments and established reference values. Associations were assessed using multivariable-adjusted conditional logistic regression models. Individuals with high levels of occupational UV-exposure were at significantly increased BCC-risk compared with individuals with low [odds ratio (OR) 1.84; 95% confidence interval (95% CI) 1.19 to 2.83 and moderate (OR 1.97; 95% CI 1.20 to 3.22) occupational UV-exposure. Nonoccupational UV-exposure was not independently associated with BCC. Skin cancer prevention strategies should be expanded to the occupational setting.

Spotlighting the role of photodynamic therapy in cutaneous malignancy: an update and expansion.

PubMed

Ross, Kate; Cherpelis, Basil; Lien, Mary; Fenske, Neil

2013-12-01

Topical photodynamic therapy (PDT) is an option for the treatment of cutaneous malignancy. To present an update and expansion on a previous review of the use of PDT in the current literature in the treatment of actinic keratoses (AK), superficial and nodular basal cell carcinoma (sBCC, nBCC), squamous cell carcinoma (SCC), Bowen's disease, cutaneous T cell lymphoma (CTCL), malignant melanoma, and its use in chemoprevention. Extensive PubMed search January 2013. We find sufficient evidence to recommend the use of PDT in certain patients in the treatment of AK, Bowen's disease, sBCC, and nBCC. It is especially useful in those with contraindications to surgery, widespread areas of involvement, and large lesions. Not only can it be considered superior to other therapies as far as recovery time, tolerance, and cosmetic outcomes, but it also should be considered, when indicated, as first-line treatment in the above conditions. Investigations continue for the use of PDT in the treatment of melanoma, SCC, chemoprevention, and CTCL. © 2013 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.

The molecular electronic device and the biochip computer: present status.

PubMed

Haddon, R C; Lamola, A A

1985-04-01

The idea that a single molecule might function as a self-contained electronic device has been of interest for some time. However, a fully integrated version--the biochip or the biocomputer, in which both production and assembly of molecular electronic components is achieved through biotechnology-is a relatively new concept that is currently attracting attention both within the scientific community and among the general public. In the present article we draw together some of the approaches being considered for the construction of such devices and delineate the revolutionary nature of the current proposals for molecular electronic devices (MEDs) and biochip computers (BCCs). With the silicon semiconductor conductor industry already in place and in view of the continuing successes of the lithographic process it seems appropriate to ask why the highly speculative MED or BCC has engendered such interest. In some respects the answer is paradigmatic as much as it is real. It is perhaps best stated as the promise of the realm of the molecular. Thus it is envisioned that devices will be constructed by assembly of individual molecular electronic components into arrays, thereby engineering from small upward rather than large downward as do current lithographic techniques. An important corollary of the construction technique is that the functional elements of such an array would be individual molecules rather than macroscopic ensembles. These two aspects of the MED/BCC--assembly of molecular arrays and individually accessible functional molecular units--are truly revolutionary. Both require scientific breakthroughs and the necessary principles, quite apart from the technology, remain essentially unknown. It is concluded that the advent of the MED/BCC still lies well before us. The twin criteria of utilization of individual molecules as functional elements and the assembly of such elements remains as elusive as ever. Biology engineers structures on the molecular scale but biomolecules do not seem to be imbued with useful electronic properties. Molecular beam epitaxy and thin-film techniques produce electronic devices but they "engineer down" and are currently unable to generate individual molecular units. The potential of the MED/BCC field is matched only by the obstacles that must be surmounted for its realization.

The molecular electronic device and the biochip computer: present status.

PubMed Central

Haddon, R C; Lamola, A A

1985-01-01

The idea that a single molecule might function as a self-contained electronic device has been of interest for some time. However, a fully integrated version--the biochip or the biocomputer, in which both production and assembly of molecular electronic components is achieved through biotechnology-is a relatively new concept that is currently attracting attention both within the scientific community and among the general public. In the present article we draw together some of the approaches being considered for the construction of such devices and delineate the revolutionary nature of the current proposals for molecular electronic devices (MEDs) and biochip computers (BCCs). With the silicon semiconductor conductor industry already in place and in view of the continuing successes of the lithographic process it seems appropriate to ask why the highly speculative MED or BCC has engendered such interest. In some respects the answer is paradigmatic as much as it is real. It is perhaps best stated as the promise of the realm of the molecular. Thus it is envisioned that devices will be constructed by assembly of individual molecular electronic components into arrays, thereby engineering from small upward rather than large downward as do current lithographic techniques. An important corollary of the construction technique is that the functional elements of such an array would be individual molecules rather than macroscopic ensembles. These two aspects of the MED/BCC--assembly of molecular arrays and individually accessible functional molecular units--are truly revolutionary. Both require scientific breakthroughs and the necessary principles, quite apart from the technology, remain essentially unknown. It is concluded that the advent of the MED/BCC still lies well before us. The twin criteria of utilization of individual molecules as functional elements and the assembly of such elements remains as elusive as ever. Biology engineers structures on the molecular scale but biomolecules do not seem to be imbued with useful electronic properties. Molecular beam epitaxy and thin-film techniques produce electronic devices but they "engineer down" and are currently unable to generate individual molecular units. The potential of the MED/BCC field is matched only by the obstacles that must be surmounted for its realization. PMID:3856865

Early-Onset Basal Cell Carcinoma and Indoor Tanning: A Population-Based Study

PubMed Central

Zens, M. Scot; Li, Zhigang; Stukel, Therese A.; Perry, Ann E.; Gilbert-Diamond, Diane; Sayarath, Vicki; Stephenson, Rita S.; Barton, Dorothea; Nelson, Heather H.; Spencer, Steven K.

2014-01-01

OBJECTIVE: Indoor tanning with UV radiation–emitting lamps is common among adolescents and young adults. Rising incidence rates of basal cell carcinoma (BCC) have been reported for the United States and elsewhere, particularly among those diagnosed at younger ages. Recent epidemiologic studies have raised concerns that indoor tanning may be contributing to early occurrence of BCC, and younger people may be especially vulnerable to cancer risk associated with this exposure. Therefore, we sought to address these issues in a population-based case–control study from New Hampshire. METHODS: Data on indoor tanning were obtained on 657 cases of BCC and 452 controls ≤50 years of age. RESULTS: Early-onset BCC was related to indoor tanning, with an adjusted odds ratio (OR) of 1.6 (95% confidence interval, 1.3–2.1). The strongest association was observed for first exposure as an adolescent or young adult, with a 10% increase in the OR with each age younger at first exposure (OR per year of age ≤23 = 1.1; 95% confidence interval, 1.0–1.2). Associations were present for each type of device examined (ie, sunlamps, tanning beds, and tanning booths). CONCLUSIONS: Our findings suggest early exposure to indoor tanning increases the risk of early development of BCC. They also underscore the importance of counseling adolescents and young adults about the risks of indoor tanning and for discouraging parents from consenting minors to this practice. PMID:24958589

Early-onset basal cell carcinoma and indoor tanning: a population-based study.

PubMed

Karagas, Margaret R; Zens, M Scot; Li, Zhigang; Stukel, Therese A; Perry, Ann E; Gilbert-Diamond, Diane; Sayarath, Vicki; Stephenson, Rita S; Barton, Dorothea; Nelson, Heather H; Spencer, Steven K

2014-07-01

Indoor tanning with UV radiation-emitting lamps is common among adolescents and young adults. Rising incidence rates of basal cell carcinoma (BCC) have been reported for the United States and elsewhere, particularly among those diagnosed at younger ages. Recent epidemiologic studies have raised concerns that indoor tanning may be contributing to early occurrence of BCC, and younger people may be especially vulnerable to cancer risk associated with this exposure. Therefore, we sought to address these issues in a population-based case-control study from New Hampshire. Data on indoor tanning were obtained on 657 cases of BCC and 452 controls ≤50 years of age. Early-onset BCC was related to indoor tanning, with an adjusted odds ratio (OR) of 1.6 (95% confidence interval, 1.3-2.1). The strongest association was observed for first exposure as an adolescent or young adult, with a 10% increase in the OR with each age younger at first exposure (OR per year of age ≤23 = 1.1; 95% confidence interval, 1.0-1.2). Associations were present for each type of device examined (ie, sunlamps, tanning beds, and tanning booths). Our findings suggest early exposure to indoor tanning increases the risk of early development of BCC. They also underscore the importance of counseling adolescents and young adults about the risks of indoor tanning and for discouraging parents from consenting minors to this practice. Copyright © 2014 by the American Academy of Pediatrics.

Comparison of risk patterns in carcinoma and melanoma of the skin in men: a multi-centre case–case–control study

PubMed Central

Zanetti, R; Rosso, S; Martinez, C; Nieto, A; Miranda, A; Mercier, M; Loria, D I; Østerlind, A; Greinert, R; Navarro, C; Fabbrocini, G; Barbera, C; Sancho-Garnier, H; Gafà, L; Chiarugi, A; Mossotti, R

2006-01-01

We directly compared risk factors between 214 histologically confirmed melanomas (CMM), 215 basal-cell carcinomas (BCC) and 139 squamous-cell carcinomas (SCC) in a multiple case–case–control study with 349 controls from patients without dermatological disease admitted to the same hospitals. Subjects with fair hair had a significant risk increase for all types of tumours at a comparable level (ORadj for blonde hair: CMM 2.3; SCC 2.4; BCC 2.3). The effect of pale eyes was significant and similar for CMM and BCC (ORadj 2.6). Intermittent sun exposure measured in hours spent at beach during holidays was significant for both CMM (ORadj 2.6 for more than 7000 lifelong hours) and BCC (ORadj 2.1 for more than 7000 lifelong hours), while SCC exhibited a significant risk increase for chronic exposure to sunlight measured in hours of outdoor work (ORadj 2.2 for more than 6000 lifelong hours). In the case–case comparison using a multinomial logistic regression model, we found a statistically significant risk difference for pale eyes, and number of naevi in the CMM group, compared to other skin cancers. For intermittent sun exposure, there was a significant risk difference of BCC when compared to the risk of SCC. Factors influencing risk of SCC are different, with chronic exposure to sun playing a major role in causing this type of carcinoma. PMID:16495934

Basaloid tumors in nevus sebaceus revisited: the follicular stem cell marker PHLDA1 (TDAG51) indicates that most are basal cell carcinomas and not trichoblastomas.

PubMed

Sellheyer, Klaus; Cribier, Bernard; Nelson, Paula; Kutzner, Heinz; Rütten, Arno

2013-05-01

Until the 1990s, basal cell carcinoma (BCC) was viewed as the most common epithelial neoplasm developing in association with nevus sebaceus (NS). Currently, trichoblastoma is thought of as the most prevalent basaloid neoplasm in NS. The follicular stem cell marker pleckstrin homology-like domain, family A, member 1 (PHLDA1) also known as T-cell death-associated gene 51 (TDAG51) labels trichoepithelioma (TE) but not BCC. Therefore, we explored its usefulness in basaloid neoplasms developing in NS. We studied immunohistochemically PHLDA1 in 10 nodular BCCs, 11 TEs, 11 trichoblastomas and 25 NS with basaloid tumors. Additionally, we examined the expression of BCC marker BerEP4 and the distribution of Merkel cells that function as surrogate markers for benign follicular neoplasms. Nineteen of the 25 basaloid tumors in NS were PHLDA1-negative comparable to BCC arising de novo and six tumors were PHLDA1-positive comparable to solitary trichoblastomas and TEs. Fewer Merkel cells were seen in BCCs associated with NS when compared with trichoblastoma. BerEP4 did not discriminate between the neoplasms. We raise concern that the unquestioned assessment that basaloid tumors developing in association with NS represent mostly trichoblastomas and not BCC may not be true. This influences clinical care, as it is paramount in the decision of whether to excise these lesions or not. Copyright © 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

A multistate investigation of health care-associated Burkholderia cepacia complex infections related to liquid docusate sodium contamination, January-October 2016.

PubMed

Glowicz, Janet; Crist, Matthew; Gould, Carolyn; Moulton-Meissner, Heather; Noble-Wang, Judith; de Man, Tom J B; Perry, K Allison; Miller, Zachary; Yang, William C; Langille, Stephen; Ross, Jessica; Garcia, Bobbiejean; Kim, Janice; Epson, Erin; Black, Stephanie; Pacilli, Massimo; LiPuma, John J; Fagan, Ryan

2018-06-01

Outbreaks of health care-associated infections (HAIs) caused by Burkholderia cepacia complex (Bcc) have been associated with medical devices and water-based products. Water is the most common raw ingredient in nonsterile liquid drugs, and the significance of organisms recovered from microbiologic testing during manufacturing is assessed using a risk-based approach. This incident demonstrates that lapses in manufacturing practices and quality control of nonsterile liquid drugs can have serious unintended consequences. An epidemiologic and laboratory investigation of clusters of Bcc HAIs that occurred among critically ill, hospitalized, adult and pediatric patients was performed between January 1, 2016, and October 31, 2016. One hundred and eight case patients with Bcc infections at a variety of body sites were identified in 12 states. Two distinct strains of Bcc were obtained from patient clinical cultures. These strains were found to be indistinguishable or closely related to 2 strains of Bcc obtained from cultures of water used in the production of liquid docusate, and product that had been released to the market by manufacturer X. This investigation highlights the ability of bacteria present in nonsterile, liquid drugs to cause infections or colonization among susceptible patients. Prompt reporting and thorough investigation of potentially related infections may assist public health officials in identifying and removing contaminated products from the market when lapses in manufacturing occur. Copyright © 2018 Association for Professionals in Infection Control and Epidemiology, Inc. All rights reserved.

High-resolution imaging of basal cell carcinoma: a comparison between multiphoton microscopy with fluorescence lifetime imaging and reflectance confocal microscopy.

PubMed

Manfredini, Marco; Arginelli, Federica; Dunsby, Christopher; French, Paul; Talbot, Clifford; König, Karsten; Pellacani, Giovanni; Ponti, Giovanni; Seidenari, Stefania

2013-02-01

The aim of this study was to compare morphological aspects of basal cell carcinoma (BCC) as assessed by two different imaging methods: in vivo reflectance confocal microscopy (RCM) and multiphoton tomography with fluorescence lifetime imaging implementation (MPT-FLIM). The study comprised 16 BCCs for which a complete set of RCM and MPT-FLIM images were available. The presence of seven MPT-FLIM descriptors was evaluated. The presence of seven RCM equivalent parameters was scored in accordance to their extension. Chi-squared test with Fisher's exact test and Spearman's rank correlation coefficient were determined between MPT-FLIM scores and adjusted-RCM scores. MPT-FLIM and RCM descriptors of BCC were coupled to match the descriptors that define the same pathological structures. The comparison included: Streaming and Aligned elongated cells, Streaming with multiple directions and Double alignment, Palisading (RCM) and Palisading (MPT-FLIM), Typical tumor islands, and Cell islands surrounded by fibers, Dark silhouettes and Phantom islands, Plump bright cells and Melanophages, Vessels (RCM), and Vessels (MPT-FLIM). The parameters that were significantly correlated were Melanophages/Plump Bright Cells, Aligned elongated cells/Streaming, Double alignment/Streaming with multiple directions, and Palisading (MPT-FLIM)/Palisading (RCM). According to our data, both methods are suitable to image BCC's features. The concordance between MPT-FLIM and RCM is high, with some limitations due to the technical differences between the two devices. The hardest difficulty when comparing the images generated by the two imaging modalities is represented by their different field of view. © 2012 John Wiley & Sons A/S.

First-principles study of the surface properties of U-Mo system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mei, Zhi-Gang; Liang, Linyun; Yacout, Abdellatif M.

U-Mo alloys are promising fuels for future high-performance research reactors with low enriched uranium. Surface properties, such as surface energy, are important inputs for mesoscale simulations (e.g., phase field method) of fission gas bubble behaviors in irradiated nuclear fuels. The lack of surface energies of U-Mo alloys prevents an accurate modeling of the morphology of gas bubbles and gas bubble-induced fuel swelling. To this end, we study the surface properties of U-Mo system, including bcc Mo, alpha-U, gamma-U, and gamma U-Mo alloys. All surfaces up to a maximum Miller index of three and two are calculated for cubic Mo andmore » gamma-U and non-cubic alpha-U, respectively. The equilibrium crystal shapes of bcc Mo, alpha-U and gamma-U are constructed using the calculated surface energies. The dominant surface orientations and the area fraction of each facet are determined from the constructed equilibrium crystal shape. The disordered gamma U-Mo alloys are simulated using the Special Quasirandom Structure method. The (1 1 0) and (1 0 0) surface energies of gamma U-7Mo and U-10Mo alloys are predicted to lie between those of gamma-U and bcc Mo, following a linear combination of the two constituents' surface energies. To better compare with future measurements of surface energies, the area fraction weighted surface energies of alpha-U, gamma-U and gamma U-7Mo and U-10Mo alloys are also predicted. (C) 2017 Published by Elsevier B.V.« less

Subseasonal prediction of the heat wave of December 2013 in Southern South America by the POAMA and BCC-CPS models

NASA Astrophysics Data System (ADS)

Osman, Marisol; Alvarez, Mariano S.

2018-01-01

The prediction skill of subseasonal forecast models is evaluated for a strong and long-lasting heat wave occurred in December 2013 over Southern South America. Reforecasts from two models participating in the WCRP/WWRP Subseasonal to Seasonal project, the Bureau of Meteorology POAMA and Beijing Climate Center model BCC-CPS were considered to evaluate their skill in forecasting temperature and circulation anomalies during that event. The POAMA reforecast of 32-member ensemble size, initialized every five days, and BCC-CPS reforecast of 4-member ensemble size for the same date of POAMA plus the previous 4 days were considered. Weekly ensemble-mean forecasts were computed with leadtimes from 2 days up to 24 days every 5 days. Weekly anomalies were calculated for observations from 13th of December to 31st of December 2013. Anomalies for both observations and reforecast were calculated with respect to their own climatology. Results show that the ensemble mean warm anomalies forecasted for week 1 and 2 of the heat wave resulted more similar to the observations for the POAMA model, especially for longer leads. The BCC-CPS performed better for leads shorter than 7 (14) for week 1 (2). For week 3 the BCC-CPS outperformed the POAMA model, particularly at shorter leads, locating more accurately the maxima of the anomalies. In a probabilistic approach, POAMA predicted with a higher chance than BCC-CPS the excess of the upper tercile of temperature anomalies for almost every week and lead time. The forecast of the circulation anomalies over South America could be used to explain the location of the highest temperature anomalies. In summary, for this case, models skill in forecasting surface temperature in a context of a heat wave resulted moderate at lead times longer than the fortnight. However, this study is limited to model-to-model analysis and a multi-model ensemble strategy might increase the skill.

Operating and Managing a Backup Control Center

NASA Technical Reports Server (NTRS)

Marsh, Angela L.; Pirani, Joseph L.; Bornas, Nicholas

2010-01-01

Due to the criticality of continuous mission operations, some control centers must plan for alternate locations in the event an emergency shuts down the primary control center. Johnson Space Center (JSC) in Houston, Texas is the Mission Control Center (MCC) for the International Space Station (ISS). Due to Houston s proximity to the Gulf of Mexico, JSC is prone to threats from hurricanes which could cause flooding, wind damage, and electrical outages to the buildings supporting the MCC. Marshall Space Flight Center (MSFC) has the capability to be the Backup Control Center for the ISS if the situation is needed. While the MSFC Huntsville Operations Support Center (HOSC) does house the BCC, the prime customer and operator of the ISS is still the JSC flight operations team. To satisfy the customer and maintain continuous mission operations, the BCC has critical infrastructure that hosts ISS ground systems and flight operations equipment that mirrors the prime mission control facility. However, a complete duplicate of Mission Control Center in another remote location is very expensive to recreate. The HOSC has infrastructure and services that MCC utilized for its backup control center to reduce the costs of a somewhat redundant service. While labor talents are equivalent, experiences are not. Certain operations are maintained in a redundant mode, while others are simply maintained as single string with adequate sparing levels of equipment. Personnel at the BCC facility must be trained and certified to an adequate level on primary MCC systems. Negotiations with the customer were done to match requirements with existing capabilities, and to prioritize resources for appropriate level of service. Because some of these systems are shared, an activation of the backup control center will cause a suspension of scheduled HOSC activities that may share resources needed by the BCC. For example, the MCC is monitoring a hurricane in the Gulf of Mexico. As the threat to MCC increases, HOSC must begin a phased activation of the BCC, while working resource conflicts with normal HOSC activities. In a long duration outage to the MCC, this could cause serious impacts to the BCC host facility s primary mission support activities. This management of a BCC is worked based on customer expectations and negotiations done before emergencies occur. I.

Synthesis of core-shell iron nanoparticles via a new (novel) approach

NASA Astrophysics Data System (ADS)

Chaudhary, Rakesh P.; Koymen, Ali R.

2014-03-01

Carbon-encapsulated iron (Fe) nanoparticles were synthesized by a newly developed method in toluene. Transmission Electron Microscopy (TEM) and High Resolution Transmission Electron Microscopy (HRTEM) of the as prepared sample reveal that core-shell nanostructures have been formed with Fe as core and graphitic carbon as shell. Fe nanoparticles with diameter 11nm to 102 nm are encapsulated by 6-8 nm thick graphitic carbon layers. There was no iron carbide formation observed between the Fe core and the graphitic shell. The Fe nanoparticles have body centered cubic (bcc) crystal structure. The magnetic hysteresis loop of the as synthesized powder at room temperature showed a saturation magnetization of 9 Am2 kg-1. After thermal treatment crystalline order of the samples improved and hence saturation magnetization increased to 24 Am2kg-1. We foresee that the carbon-encapsulated Fe nanoparticles are biologically friendly and could have potential applications in Magnetic Resonance Imaging (MRI) and Photothermal cancer therapy.

Hydrogen migration modeling in a symmetric tilt boundary of the Iron-Chromium system

NASA Astrophysics Data System (ADS)

Ramunni, V. P.

2018-03-01

Previous experimental studies of H permeation in 9%Cr-Fe alloys have found a permeation coefficient 10 times lower and a diffusion coefficient 200 times lower than in pure annealed Fe. In an effort to shed some light on the microscopic origin of these findings, we perform an extensive study of Fe, Cr, and H migration in a high-angle symmetric tilt grain boundary in bcc Fe, both via vacancy and interstitial mechanism. This is undertaken in the framework of transition state theory with the relevant energies obtained from classical interatomic potentials, and partially from Density Functional Theory calculations, in order to check the consistency of structures. Trapping sites for H and possible migration paths are explored. We find that the presence of Cr and its migration via vacancy and interstitials creates the conditions in produce stable preferential trapping sites for H in the grain boundary, that delay the H migration, thereby explaining the experimental results.

EBSD as a tool to identify and quantify bainite and ferrite in low-alloyed Al-TRIP steels.

PubMed

Zaefferer, S; Romano, P; Friedel, F

2008-06-01

Bainite is thought to play an important role for the chemical and mechanical stabilization of metastable austenite in low-alloyed TRIP steels. Therefore, in order to understand and improve the material properties, it is important to locate and quantify the bainitic phase. To this aim, electron backscatter diffraction-based orientation microscopy has been employed. The main difficulty herewith is to distinguish bainitic ferrite from ferrite because both have bcc crystal structure. The most important difference between them is the occurrence of transformation induced geometrically necessary dislocations in the bainitic phase. To determine the areas with larger geometrically necessary dislocation density, the following orientation microscopy maps were explored: pattern quality maps, grain reference orientation deviation maps and kernel average misorientation maps. We show that only the latter allow a reliable separation of the bainitic and ferritic phase. The kernel average misorientation threshold value that separates both constituents is determined by an algorithm that searches for the smoothness of the boundaries between them.

Auger electron diffraction study of V/Fe(100) interface formation

NASA Astrophysics Data System (ADS)

Huttel, Y.; Avila, J.; Asensio, M. C.; Bencok, P.; Richter, C.; Ilakovac, V.; Heckmann, O.; Hricovini, K.

1998-05-01

Vanadium atoms present a magnetic moment different to zero when they are part of a thin film deposited on Fe or as a bimetallic Fe-V alloy. The understanding of this phenomenon can only be achieved with a correct structural description of these types of systems. We report an Auger electron diffraction investigation of V films grown on body cubic centred (b.c.c.) Fe(100) substrates. Angular-scanned Auger electron diffraction (AED) patterns of V L 23M 23M 4 (473 eV) and Fe L 3VV (703 eV) show the formation of a well-ordered V/Fe interface even at room temperature. The AED patterns of V films in the range of vanadium submonolayer provide evidence of an isotropic Auger emission, indicating the absence of interdiffusion of V atoms into the Fe substrate and absence of cluster growth of the V film. The annealing of these films up to 400°C does not activate the substitution of the topmost Fe surface layers by V atoms.

Effect of metallurgical structure and properties on adhesion and friction behavior of cobalt alloys

NASA Technical Reports Server (NTRS)

Keller, D. V., Jr.; Shatynski, S.; Vedamanikam, P. M.

1972-01-01

The metallurgical structure and some of the mechanical properties of two cobalt alloys, cobalt-50% iron and cobalt-25% molybdenum-10% chromium, were determined under various heat treated conditions. The mechanical properties of the bcc disordered Co-50Fe alloy, which was found to be very brittle, indicated an exceedingly low fracture strength, low hardness, and very weak grain boundary strength. Ordering by suitable heat treatment only produced a more brittle material with a lower fracture strength and a slightly higher hardness value. Work hardening was found to produce a finer grain structure and a greater grain boundary strength. Tensile properties were examined. It was found that the Co-25Mo-10Cr alloy was difficult to place in the alpha Co solid solution condition, which limited the ability to use precipitation as a hardening reaction. Over two hundred adhesion cycles from zero contact load, to maximum load, to fracture were conducted between couples for each of the above alloys in an ultrahigh vacuum system which would permit the sample surfaces to be cleaned of all contaminant layers. In the Co-50Fe case, the calculated fracture stress from the adhesion tests showed values in the range of 80 to 150 k.s.i., which is about ten times greater than the values from tension tests.

Machine-learning approach for local classification of crystalline structures in multiphase systems

NASA Astrophysics Data System (ADS)

Dietz, C.; Kretz, T.; Thoma, M. H.

2017-07-01

Machine learning is one of the most popular fields in computer science and has a vast number of applications. In this work we will propose a method that will use a neural network to locally identify crystal structures in a mixed phase Yukawa system consisting of fcc, hcp, and bcc clusters and disordered particles similar to plasma crystals. We compare our approach to already used methods and show that the quality of identification increases significantly. The technique works very well for highly disturbed lattices and shows a flexible and robust way to classify crystalline structures that can be used by only providing particle positions. This leads to insights into highly disturbed crystalline structures.

Writing with a Byte. Computers: An Effective Teaching Methodology To Improve Freshman Writing Skills.

ERIC Educational Resources Information Center

Williamson, Barbara L.

A study was conducted at Florida's Brevard Community College (BCC) to determine the effectiveness of using artificial intelligence software to teach Freshman Composition. At BCC, Freshman Composition is taught in the computer lab, with student using WordPerfect to type their essays and Writer's Helper to flag various writing deficiencies. The…

Close Reading: Engaging and Empowering History Students through Document Analysis on ePortfolio

ERIC Educational Resources Information Center

Getman-Eraso, Jordi; Culkin, Kate

2017-01-01

This article examines the intersection of the scholarship on ePortfolio and history pedagogy through an analysis of the success of the integration of Digication's Conversations feature into history courses at Bronx Community College (BCC). History professors at BCC have used the feature, which allows people to highlight and comment on text and…

Blending in the Bronx: The Dimensions of Hybrid Course Development at Bronx Community College

ERIC Educational Resources Information Center

Wach, Howard; Broughton, Laura; Powers, Stephen

2011-01-01

To support the growth of its blended courses, Bronx Community College (BCC), a unit of the City University of New York (CUNY), participated in a CUNY-sponsored initiative to increase blended learning options for students. The initiative allowed BCC to expand its existing faculty development program. This paper describes major aspects of the…

Basal cell carcinoma of the nipple-areola complex: a case report.

PubMed

Huang, Ching-Wen; Pan, Ching-Kuen; Shih, Teng-Fu; Tsai, Cheng-Chien; Juan, Chung-Chou; Ker, Chen-Guo

2005-10-01

Basal cell carcinoma (BCC) of the nipple-areola complex is very rare. Only 24 cases were reported in the literature and 17 (70.8%) of these cases arose in men. Most of the cases were treated with simple excision. We report on a case of BCC of the nipple-areola complex in a 46-year-old woman, treated with partial mastectomy. Metastasis to the axillary lymph nodes had been noted in 3 (12.5%) of the 24 reported cases of BCC of the nipple-areola complex. Thus, we applied the concept of the sentinel lymph node to detect possible metastases of axillary lymph nodes, letting us avoid the unnecessary axillary lymph node dissection and possible future morbidity.

Highly (002) textured large grain bcc Cr{sub 80}Mn{sub 20} seed layer on Cr{sub 50}Ti{sub 50} amorphous layer for FePt-C granular film

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeon, Seong-Jae, E-mail: jsjigst@ecei.tohoku.ac.jp; Saito, Shin; Hinata, Shintaro

Effect of bcc Cr{sub 80}Mn{sub 20} seed layer and Cr{sub 50}Ti{sub 50} amorphous texture inducing layer on the heteroepitaxy system in FePt-C granular film was studied by introducing a new concept of the layered structure. The concept suggested that the large grain seed layer in which the crystallographic texture was initially formed on an amorphous layer in the layered structure can reduce the angular distribution of (002) c-axis crystal orientation in the FePt-C granular film owing to heteroepitaxial growth. Structure analysis by X-ray diffraction revealed that (1) when the substrate heating temperature was elevated from 300 °C to 500 °C, grain sizemore » in the seed layer increased from 9.8 nm to 11.6 nm, and then decreased with further increasing the substrate temperature. The reduction of the grain size over 500 °C corresponds to the crystallization of the amorphous texture inducing layer, (2) when the grain size increased from 9.8 nm to 11.6 nm, the angular distribution of the (002) orientation in the seed layer dramatically decreased from 13.7° to 4.1°. It was shown that the large grain seed layer increased the perpendicular hysteresis in FePt-C granular film.« less

Effects of high pressure on microstructure evolution and crystallization mechanisms during solidification of nickel

NASA Astrophysics Data System (ADS)

Zhang, Hai-Tao; Mo, Yun-Fei; Liu, Rang-Su; Tian, Ze-An; Liu, Hai-Rong; Hou, Zhao-Yang; Zhou, Li-Li; Liang, Yong-Chao; Peng, Ping

2018-03-01

To deeply understand the effects of high pressure on microstructural evolutions and crystallization mechanisms of liquid metal Ni during solidification process, MD simulation studies have been performed under 7 pressures of 0 ˜ 30 GPa, at cooling rate of 1.0 × 1011 K s-1. Adopting several microstructural analyzing methods, especially the cluster-type index method (CTIM-2) to analyze the local microstructures in the system. It is found that the pressure has important influence on the formation and evolution of microstructures, especially of the main basic clusters in the system. All the simulation systems are directly solidified into crystal structures, and the 1421, 1422, 1441 and 1661 bond-types, as well the FCC (12 0 0 0 12 0), HCP (12 0 0 0 6 6) and BCC (14 6 0 8 0 0) clusters play a key role in the microstructure transitions from liquid to crystal structures. The crystallization temperature T c is enhanced almost linearly with the increase of pressure. Highly interesting, it is found for the first time that there is an important phase transformation point from FCC to BCC structures between 20 ˜ 22.5 GPa during the solidification processes from the same initial liquid system at the same cooling rate. And the effect of increasing pressure is similar to that of decreasing cooling rate for the phase transformation of microstructures during solidification process of liquid metal Ni system, though they have different concrete effecting mechanisms.

Evolution of structural and magnetic properties of amorphous CoFeB film with thermal annealing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gupta, Ranjeeta; Gupta, Ajay; Gupta, Mukul

2013-08-14

Evolution of structural and magnetic properties of amorphous Co{sub 68}Fe{sub 14}B{sub 18} thin film with thermal annealing has been studied. Initially, the film exhibits a structural relaxation as evidenced by annihilation of excess free volume and an increase in topological short range order. Annealing at 473 K results in precipitation of primary phase followed by formation of boride phase at a still higher temperature of 598 K. Iron preferentially precipitates out in the primary phase, resulting in the formation of bcc Co{sub 58}Fe{sub 41}. This suggests an affinity of Co towards B. Such affinity between Co and B is evidencedmore » even in the as-deposited film, using hard x-ray photoelectron spectroscopy (HAXPES) measurements. As-deposited film exhibits an in-plane uniaxial magnetic anisotropy which disappears at a temperature well beyond crystallization temperature, suggesting that the origin of anisotropy is mainly a chemical short range order in the system. Variation in the coercivity with thermal annealing can be understood in terms of random anisotropy model. Precise measurement of Fe self-diffusion using neutron reflectivity shows that diffusion length associated with annihilation of excess free volume in the film is about 0.5 nm. This agrees with the length scale of structural fluctuations in amorphous alloys. Secondary ion mass spectrometry measurements show that thermal annealing results in depletion of B in the region of the interface with the substrate, with associated faster Fe diffusion in this region. This faster diffusion of Fe may be a possible cause of preferential crystallization of the film in the interfacial region as seen in some earlier studies.« less