Spray pyrolysis-derived robust ferroelectric BiFeO3 thin films

Scalable and low-cost synthesis of high-quality ferroic films is critical for the development of advanced electronic devices and sensors. Here, we employ solution-based spray pyrolysis to fabricate bismuth ferrite thin films on glass substrates and explore the impact of annealing conditions to attain functional thin films of superior quality and switchable polarization. Optimised thin films display polycrystalline nanostructured grains with the highest X-ray diffraction intensity along the (110) orientation and a mixed Fe2+/3+ valence suggesting the presence of oxygen vacancies. The optimized films show a complex ferroelectric domain microstructure and exhibit robust nanoscale polarization switching in the range of several volts. Domains are found to scale with the sizes of nanocrystalline grains, which points to the role of surface-energy-related mechanisms affecting the domain patterns. Our results demonstrate the potential of spray pyrolysis for the fabrication of high-quality ferroelectric thin films and provide new opportunities for the development of low-cost scalable advanced electronic devices.

Lessons from Dairy Farmers for Occupational Allergy and Respiratory Disease

PURPOSE OF REVIEW

Exposure to bioaerosols at dairies has long been associated with allergy, respiratory disease, and decreases in lung function. Recent advancements in exposure assessments have aided our understanding on the size distribution and composition of these bioaerosols, but investigations focusing solely on exposures may overlook important intrinsic factors impacting worker's susceptibility to disease.

RECENT FINDINGS

In our review, we discuss the most recent studies examining the exposures and genetic factors that contribute to occupational disease in dairy work. We also review more recent concerns in livestock work associated with zoonotic pathogens, antimicrobial resistant genes, and the role of the human microbiome. The studies highlighted in this review demonstrate the need for further research to better understand bioaerosol exposure-response relationships in the context of extrinsic and intrinsic factors, antibiotic-resistant genes, viral pathogens, and the human microbiome to help inform effective interventions that improve respiratory health among dairy farmers.

Scaling, rotation, and channeling behavior of helical and skyrmion spin textures in thin films of Te-doped Cu2OSeO3

Topologically nontrivial spin textures such as vortices, skyrmions, and monopoles are promising candidates as information carriers for future quantum information science. Their controlled manipulation including creation and annihilation remains an important challenge toward practical applications and further exploration of their emergent phenomena. Here, we report controlled evolution of the helical and skyrmion phases in thin films of multiferroic Te-doped Cu₂OSeO₃ as a function of material thickness, dopant, temperature, and magnetic field using in situ Lorentz phase microscopy. We report two previously unknown phenomena in chiral spin textures in multiferroic Cu₂OSeO₃: anisotropic scaling and channeling with a fixed-Q state. The skyrmion channeling effectively suppresses the recently reported second skyrmion phase formation at low temperature. Our study provides a viable way toward controlled manipulation of skyrmion lattices, envisaging chirality-controlled skyrmion flow circuits and enabling precise measurement of emergent electromagnetic induction and topological Hall effects in skyrmion lattices.

Nanoscale electromechanical and electronic properties of free-standing ZnO nano- and microstructured platelets

The piezoelectric response, conductivity and surface potential of individual grains and grain boundaries in free-standing polycrystalline ZnO nano- and microstructured platelets is studied using scanning probe based techniques on the nanoscale. We find that applied dc electric fields can alter the piezoresponse in individual grains, as well as the local nanoscale conductivity, and invert the relative surface potential at grain boundaries. This can be attributed to defect accumulation at the grain surfaces and at grain boundaries and the associated density of carriers. Together with recently observed below-bandgap photoconductivity at grain boundaries, the presented observation opens new venues for potential nanoelectronic applications that rely on grain and grain boundary engineering and functionality in a wide-bandgap transparent material.

Mechanical stress-induced switching kinetics of ferroelectric thin films at the nanoscale

We investigate ferroelectric domain structure and piezoelectric response under variable mechanical compressive stress in Pb(Zr_0.2TiO_0.8)O₃ (PZT) thin films using high-resolution piezoresponse force microscopy (PFM) and an in situ sample bending stage. Measurements reveal a drastic change in the ferroelectric domain structure which is presented along with details of the mediating switching process involving domain wall motion, nucleation, and domain wall roughening under an applied external mechanical stimulus. Furthermore, local PFM hysteresis loops reveal significant changes in the observed coercive biases under applied stress. The PFM hysteresis loops become strongly imprinted under increasing applied compressive stress.

Health-Related Behaviour Among Children of Childhood Cancer Survivors in Germany

Purpose: Childhood cancer survivors fear that previous therapy could not only impair their own but also their children's health. We examined whether health-related behaviour in children of childhood cancer survivors differs from the general population. Methods: Our first nationwide survey wave (2013-2014) surveyed offspring health in 396 German childhood cancer survivors known to have a child of their own. Answers about health behaviour were analysed using descriptive statistics. Data were collected for 418 offspring and 394 could be integrated for matched-pair analyses with data from the German general population (KIGGS, n=17 641). Results: Teeth-cleaning routine, body-mass-index or subjective body image evaluation by parents were no different from children in the general population. Parents who included a cancer survivor smoked less in the presence of their children (p=0.01). During pregnancy, mothers in cancer survivor parent pairs abstained from drinking alcohol more often (p=0.01) and smoked less (p=0.05). While the calculated effect sizes (Phi) were generally low (0.135-0.247), children from cancer survivors played less outdoors than peers did (p=0.01). Boys participated in sports outside a club more often (p=0.05) and watched less TV on weekdays (p=0.01) and girls spent more time on the computer during weekdays than peers did (p=0.01). Conclusions: This study provides the first data for health-related behaviour in cancer survivors' offspring and sheds light on differences to parenting in the general population. Multivariate analyses in a larger study population are needed to relate these differences to fear issues in cancer survivors.

Structural and electronic transformation pathways in morphotropic BiFeO3

Phase boundaries in multiferroics, in which (anti-)ferromagnetic, ferroelectric and ferroelastic order parameters coexist, enable manipulation of magnetism and electronic properties by external electric fields through switching of the polarization in the material. It has been shown that the strain-driven morphotropic phase boundaries in a single-phase multiferroic such as BiFeO₃ (BFO) can exhibit distinct electronic conductivity. However, the control of ferroelectric and phase switching and its correlation with phase boundary conductivity in this material has been a significant challenge. Supported by a thermodynamic approach, here we report a concept to precisely control different switching pathways and the associated control of electronic conductivity in mixed phase BFO. This work demonstrates a critical step to control and use non-volatile strain-conductivity coupling at the nanoscale. Beyond this observation, it provides a framework for exploring a route to control multiple order parameters coupled to ferroelastic and ferroelectric order in multiferroic materials.

Oxygen content modulation by nanoscale chemical and electrical patterning in epitaxial SrCoO3-δ (0 < δ ≤ 0.5) thin films

Fast controllable redox reactions in solid materials at room temperature are a promising strategy for enhancing the overall performance and lifetime of many energy technology materials and devices. Easy control of oxygen content is a key concept for the realisation of fast catalysis and bulk diffusion at room temperature. Here, high quality epitaxial brownmillerite SrCoO2.5 thin films have been oxidised to perovskite (P) SrCoO3 with NaClO. X-ray diffraction, scanning probe microscopy and x-ray photoelectron spectroscopy measurements were performed to investigate the structural and electronic changes of the material. The oxidised thin films were found to exhibit distinct morphological changes from an atomically flat terrace structure to forming small nanosized islands with boundaries preferentially in [100] or [010] directions all over the surface, relaxing the in-plane strain imposed by the substrate. The conductivity, or oxygen content, of each single island is confined by these textures, which can be locally patterned even further with electric poling. The high charging level at the island boundaries indicates a magnified electric capacity of SCO thin films, which could be exploited in future device geometries. This finding represents a new way of oxygen modulation with associated self-assembled charge confinement to nanoscale boundaries, offering interesting prospects in nanotechnology applications.

Complication and local recurrence rate after endoscopic resection of large high-risk colorectal adenomas of ≥3 cm in size

PURPOSE

Endoscopic resection is a widely used technique for treatment of large colorectal adenomas, but few data are available including only lesions larger than ≥2 cm. The aim of this study is to evaluate the complication and recurrence rate after endoscopic resection of high-risk colorectal adenomas ≥3 cm in size.

METHODS

Retrospective analysis of a prospectively maintained database of patients undergoing polypectomy of large colorectal polyps of ≥3 cm.

RESULTS

In 341 patients, 360 colorectal adenomas with a mean size of 3.9 cm were resected endoscopically. In 25 patients, a complication including 22 delayed bleedings (6.5%) and three perforations (0.9%) occurred. Single-variate analysis showed an increasing risk of complications for larger adenomas (3.9 vs. 4.6 cm; p ≤ 0.05). Two hundred twelve patients with 224 adenomas had undergone at least one documented follow-up endoscopy with a medium follow-up period of 16 months. In 95 resected lesions (42.4%), a residual adenoma occurred in the first follow-up colonoscopy (n = 88, 92.6%) or a recurrent adenoma occurred after at least one negative follow-up colonoscopy (n = 7, 7.4%). In multivariate analysis, risk factors were lesion size, sessile growth pattern, and the performing endoscopist. The complication and recurrence rate correlated inversely between endoscopists.

CONCLUSIONS

The present study is the largest study showing complication and recurrence rates after colorectal polypectomy of advanced colorectal adenomas of ≥3 cm in size. Polyp size was identified as the most important risk factor for complications. For the first time, this study shows that the complication rate after colorectal polypectomy of large adenomas is correlated inversely with the residual and/or recurrence rate.

Electromechanical coupling among edge dislocations, domain walls, and nanodomains in BiFeO3 revealed by unit-cell-wise strain and polarization maps

The performance of ferroelectric devices, for example, the ferroelectric field effect transistor, is reduced by the presence of crystal defects such as edge dislocations. For example, it is well-known that edge dislocations play a crucial role in the formation of ferroelectric dead-layers at interfaces and hence finite size effects in ferroelectric thin films. The detailed lattice structure including the relevant electromechanical coupling mechanisms in close vicinity of the edge dislocations is, however, not well-understood, which hampers device optimization. Here, we investigate edge dislocations in ferroelectric BiFeO3 by means of spherical aberration-corrected scanning transmission electron microscopy, a dedicated model-based structure analysis, and phase field simulations. Unit-cell-wise resolved strain and polarization profiles around edge dislocation reveal a wealth of material states including polymorph nanodomains and multiple domain walls characteristically pinned to the dislocation. We locally determine the piezoelectric tensor and identify piezoelectric coupling as the driving force for the observed phenomena, explaining, for example, the orientation of the domain wall with respect to the edge dislocation. Furthermore, an atomic model for the dislocation core is derived.

Costs of paediatric diabetes care in Germany: current situation and comparison with the year 2000

AIMS

To estimate direct costs of paediatric Type 1 diabetes care and associated factors in Germany for the year 2007 and to compare results with the costs for the year 2000.

METHODS

Our study includes clinical data and charges for any diabetes-related health care service of 14,185 continually treated subjects with paediatric diabetes aged < 20 years [52.5% male, mean age (SD) 12.1 (4.2) years], derived from a nationwide prospective patient documentation system (DPV). Health-care utilization was valued in monetary terms by using inpatient and outpatient medical fees and retail prices (perspective of the statutory health insurance). Associations between average total diabetes-related costs or various single cost categories per patient and age, sex, migration background, diabetes duration, and metabolic control were analysed by multiple regression procedures and by a two-part model for hospitalization costs. Total direct costs in the whole paediatric diabetes population in Germany were estimated. Mean costs per patient as well as total costs in the German paediatric diabetes population in 2007 were compared to 2000 costs (inflated to the year 2007).

RESULTS

Mean direct diabetes-associated costs per subject were €3524 (inter-quartile range: 1831-4743). Main cost categories were hospitalization (32%), glucose self-monitoring (29%), insulin pump therapy (18%), and insulin (15%). Based on the present estimation, the total costs of paediatric diabetes care in Germany exceeded €110 million in 2007. Compared with estimates of the year 2000, average costs per patient had increased by 20% and total costs for German paediatric diabetes care by 47%.

CONCLUSIONS

Direct costs for paediatric Type 1 diabetes care increased between 2000 and 2007, probably partly because of new therapeutic strategies and an increase in diabetes prevalence.

Evidence of sharp and diffuse domain walls in BiFeO3 by means of unit-cell-wise strain and polarization maps obtained with high resolution scanning transmission electron microscopy

Domain walls (DWs) substantially influence a large number of applications involving ferroelectric materials due to their limited mobility when shifted during polarization switching. The discovery of greatly enhanced conduction at BiFeO(3) DWs has highlighted yet another role of DWs as a local material state with unique properties. However, the lack of precise information on the local atomic structure is still hampering microscopical understanding of DW properties. Here, we examine the atomic structure of BiFeO(3) 109° DWs with pm precision by a combination of high-angle annular dark-field scanning transmission electron microscopy and a dedicated structural analysis. By measuring simultaneously local polarization and strain, we provide direct experimental proof for the straight DW structure predicted by ab initio calculations as well as the recently proposed theory of diffuse DWs, thus resolving a long-standing discrepancy between experimentally measured and theoretically predicted DW mobilities.

Abstract LB-420: Long circulating 18F-labeled liposomes for PET imaging

Liposomes are lipid nanoparticles comprised of phospholipid bilayers with an aqueous interior. They have emerged as promising multi-modality imaging agents and engender significant interest as drug delivery vehicles, e.g. doxorubicin liposomes. Although a number of methods for radiolabeling liposomes with various radionuclides have been developed, 18F is the most useful for PET imaging. In this study, preformed maleimide-PEG functionalized liposomes with a mean diameter of 70 nm were obtained by sonication of a lipid mixture consisting of DPPC, cholesterol, and DSPE-PEG2000-Mal (61:30:9) in acetate buffer (pH 6.5) followed by extrusion. 18F labeled 2-(2-(2-(2-fluoroethoxy)ethoxy)ethoxy)ethanethiol was prepared, followed by conjugation with the maleimide-PEG functionalized liposome in 0.1M acetate buffer (0.1% EDTA), pH 6.5-8.0. Liposome sizes did not differ significantly before and after the 18F labeling. The overall radiochemical yield of the reaction was 10-25% (n= 12, uncorrected) in a 180 minute radiolabeling time. Micro PET imaging of rats was done at various times, up to 4 hrs, following IV injection of the 18F liposomes and their bio-distribution was also investigated. Our imaging studies with 18F liposomes appear comparable to images from previously described labeling methods with 18F liposomes remaining in the blood pool at 4 hrs. Our results indicate that this will allow the ready availability of 18F liposomes for vascular imaging and also potentially for cancer imaging. Research Support: This study was funded by the intramural program of the National Institutes of Health.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-420. doi:1538-7445.AM2012-LB-420

Electric-field control of nonvolatile magnetization in Co40Fe40B20/Pb(Mg(1/3)Nb(2/3))(0.7)Ti(0.3)O3 structure at room temperature

We report a large and nonvolatile bipolar-electric-field-controlled magnetization at room temperature in a Co(40)Fe(40)B(20)/Pb(Mg(1/3)Nb(2/3))(0.7)Ti(0.3)O(3) structure, which exhibits an electric-field-controlled looplike magnetization. Investigations on the ferroelectric domains and crystal structures with in situ electric fields reveal that the effect is related to the combined action of 109° ferroelastic domain switching and the absence of magnetocrystalline anisotropy in Co(40)Fe(40)B(20). This work provides a route to realize large and nonvolatile magnetoelectric coupling at room temperature and is significant for applications.

Anisotropic conductance at improper ferroelectric domain walls

Transition metal oxides hold great potential for the development of new device paradigms because of the field-tunable functionalities driven by their strong electronic correlations, combined with their earth abundance and environmental friendliness. Recently, the interfaces between transition-metal oxides have revealed striking phenomena, such as insulator-metal transitions, magnetism, magnetoresistance and superconductivity. Such oxide interfaces are usually produced by sophisticated layer-by-layer growth techniques, which can yield high-quality, epitaxial interfaces with almost monolayer control of atomic positions. The resulting interfaces, however, are fixed in space by the arrangement of the atoms. Here we demonstrate a route to overcoming this geometric limitation. We show that the electrical conductance at the interfacial ferroelectric domain walls in hexagonal ErMnO(3) is a continuous function of the domain wall orientation, with a range of an order of magnitude. We explain the observed behaviour using first-principles density functional and phenomenological theories, and relate it to the unexpected stability of head-to-head and tail-to-tail domain walls in ErMnO(3) and related hexagonal manganites. As the domain wall orientation in ferroelectrics is tunable using modest external electric fields, our finding opens a degree of freedom that is not accessible to spatially fixed interfaces.

Large field-induced strains in a lead-free piezoelectric material

Piezoelectric materials exhibit a mechanical response to electrical inputs, as well as an electrical response to mechanical inputs, which makes them useful in sensors and actuators. Lead-based piezoelectrics demonstrate a large mechanical response, but they also pose a health risk. The ferroelectric BiFeO(3) is an attractive alternative because it is lead-free, and because strain can stabilize BiFeO(3) phases with a structure that resembles a morphotropic phase boundary. Here we report a reversible electric-field-induced strain of over 5% in BiFeO(3) films, together with a characterization of the origins of this effect. In situ transmission electron microscopy coupled with nanoscale electrical and mechanical probing shows that large strains result from moving the boundaries between tetragonal- and rhombohedral-like phases, which changes the phase stability of the mixture. These results demonstrate the potential of BiFeO(3) as a substitute for lead-based materials in future piezoelectric applications.

Abstract P2-06-21: RNAi Silencing of CUB-Domaining Containing Protein 1 (CDCP1) in Breast Cancer Cell Lines Results in Decreased Migration and Invasion Capacities In Vitro

Background: The orphan surface receptor CDCP1 is over-expressed in various cancers and signals via Src family kinases (SFKs). It has been shown to be involved in anchorage independency of distinct tumors [Uekita et al. 2007; Moasser 2009]. Since CDCP1 is also speculated to be involved in tumor cell migration and invasion, the following study investigated the in vitro migration and invasion of breast cancer cell lines. In order to prove if lapatinib treatment might benefit CDCP1-positive but HER2/neu-negative breast cancer patients, we investigated the level of apoptosis after lapatinib application to different cell lines.

Material and Methods: Four breast cancer cell lines were selected according to their CDCP1/HER-2/neu receptor expression (MDA-MB-231high/high; T47Dhigh/low; SKBR3low/high; MCF7neg./high). CDCP1 knock-down was achieved via nucleofection of Stealth™ RNAi (Invitrogen) against CDCP1. In vitro migration and invasion were analyzed for 48hs using trans-well assays (Merck). Migrated cells were labeled with Calcein AM and relative fluorescence units (RFU) were measured at 485/520nm. To investigate the effect of lapatinib, cells were cultured for 48hs in the presence of lapatinib (0,75 µM) as attached cells or as suspension culture on ultra-low adhesion plates, respectively. The enrichment of free nucleosomes was measured and compared between CDCP1-RNAi transfected and parental cells.

Results: When transfected with CDCP1-RNAi, migration of SKBR-3 cells was not affected (96.2% migrating cells compared to control). However, CDCP1-RNAi-transfected MDA-MB-231 cells showed a strong reduction in migration (70.2% (± 21.5%)) compared to mock-transfected cells and the observed effect was even more impressive in T47D cells (58.3± 16.1% migration compared to control; P=0,011)). Invasion of CDCP1- silenced MDA-MB-231 was reduced to 71.4% (± 5.9%) of the mock-transfected control cells. Again, T47D cells also were severely impaired by CDCP1-knock-down (0.32 ± 0.02% of invasive cells compared to control; P&lt;0.01). Lapatinib had no effect on either MDA-MB-231 cells or T47D cells at any culture conditions. However, the level of apoptotic SKBR3 cells significantly increased when cultured in suspension (1.5x) as well as adherent cells (1.8x) in the presence of lapatinib independent of CDCP1-knock down.

Conclusions: The migratory activity of breast cancer cell lines did not strictly correlate with the degree in CDCP1 expression. However, CDCP1- knock down yielded in a clearly reduced migration and invasion of MDA-MB-231 cells and was even more impressive in T47D cell line. However, no effect was observed in SKBR3 cells. Thus, CDCP1 might represent one of a panel of surface receptors that participate in cell movement. However, Lapatinib was shown to have no effect on the viability of CDCP1pos./Her2/neuneg./low cells. Nonetheless, our study reveals that CDCP1 might have a strong impact on migration and invasive capacities of breast cancer cell lines and thus represents a potential target in more individualized breast cancer therapies.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-06-21.

Domain wall conductivity in La-doped BiFeO3

The transport physics of domain wall conductivity in La-doped bismuth ferrite (BiFeO3) has been probed using variable temperature conducting atomic force microscopy and piezoresponse force microscopy in samples with arrays of domain walls in the as-grown state. Nanoscale current measurements are investigated as a function of bias and temperature and are shown to be consistent with distinct electronic properties at the domain walls leading to changes in the observed local conductivity. Our observation is well described within a band picture of the observed electronic conduction. Finally, we demonstrate an additional degree of control of the wall conductivity through chemical doping with oxygen vacancies, thus influencing the local conductive state.

Extended mapping and exploration of the vanadium dioxide stress-temperature phase diagram

Single-crystal micro- and nanomaterials often exhibit higher yield strength than their bulk counterparts. This enhancement is widely recognized in structural materials but is rarely exploited to probe fundamental physics of electronic materials. Vanadium dioxide exhibits coupled electronic and structural phase transitions that involve different structures existing at different strain states. Full understanding of the driving mechanism of these coupled transitions necessitates concurrent structural and electrical measurements over a wide phase space. Taking advantages of the superior mechanical property of micro/nanocrystals of VO(2), we map and explore its stress-temperature phase diagram over a phase space that is more than an order of magnitude broader than previously attained. New structural and electronic aspects were observed crossing phase boundaries at high-strain states. Our work shows that the actively tuning strain in micro/nanoscale electronic materials provides an effective route to investigate their fundamental properties beyond what can be accessed in their bulk counterpart.

Above-bandgap voltages from ferroelectric photovoltaic devices

In conventional solid-state photovoltaics, electron-hole pairs are created by light absorption in a semiconductor and separated by the electric field spaning a micrometre-thick depletion region. The maximum voltage these devices can produce is equal to the semiconductor electronic bandgap. Here, we report the discovery of a fundamentally different mechanism for photovoltaic charge separation, which operates over a distance of 1-2 nm and produces voltages that are significantly higher than the bandgap. The separation happens at previously unobserved nanoscale steps of the electrostatic potential that naturally occur at ferroelectric domain walls in the complex oxide BiFeO(3). Electric-field control over domain structure allows the photovoltaic effect to be reversed in polarity or turned off. This new degree of control, and the high voltages produced, may find application in optoelectronic devices.

Evaluation of CUB-Domain-Containing Protein (CDCP1)-Expression as Predictive Marker of Adhesion-Independant Cell Survival in Breast Cancer Cell Lines

Background: A crucial step in the metastatic cascade is to overcome anoikis, a type of programmed cell death after loss of cell-cell contact. CDCP1 has recently been indentified to be an essential prerequisite for anoikis resistance in lung adenocarcinoma cell lines [Uekita et al. 2007]. CDCP1 is overexpressed in distinct tumor tissues and suspected to signal via Src family kinases (SFK). Since CDCP1 overexpression has been detected in a variety of primary breast cancers and cell lines [Bühring et al. 2004], this study aimed at investigating the correlation between CDCP1 expression and anoikis-resistance in breast cancer cell lines and the involvement of SFKs.Material and Methods: Various breast cancer cell lines were tested for their CDCP1 status by FACS analysis and immunoblotting. CDCP1-negative breast cancer cell line MCF7 and primary normal breast cells were compared to the CDCP1-high cell lines MDA-MB-231 (∼90% positive cells (p.c.)), T47D (∼65% p.c.), SKBR3 (∼52% p.c.) and HBL100 (∼60% p.c.) when cultured in ultra low-adhesion culture plates. Apoptosis rate was evaluated measuring the nucleosome enrichment factor (EF). SFK-involvement was tested via proliferation analysis after treatment with SKF-inhibitor PP2 and its inactive derivate PP3. Since various types of breast cancer were influenced by the presence or absence of steroids, MDA-MB-231 cells and HBL100 cells were stimulated with ß17-Estradiol and CDCP1 expression was measured using relative quantification in qRT-PCR.Results: When grown in solution on ultra-low adhesion plates, CDCP1-negative primary normal breast cells underwent apoptosis (EF:5,29). CDCP1-high expressing MDA-MB-231 cells (EF:1,75) were less apoptotic than T47D (EF:3,68:) and SKBR3 cells (EF:4,35). However, CDCP1-negative MCF7 breast cancer cells were relatively resistant towards loss of anchorage (EF:2,03). When grown in suspension, proliferation rate of MDA-MB-231 is 6-fold lower than in normal tissue plates, both cultured with or without SFK-inhibitor PP2. Proliferation rate of CDCP1-negative MCF7 cells grown in solution in presence and absence of PP2 is even 24-fold reduced. MDA-MB-231 cells show a significant 50% reduction in RNA-levels of CDCP1 when cultured 48h in presence of ß17-ER (10-8M). However, in HBL100 cells, no change of RNA-level of CDCP1 was detectable.Conclusions: Anoikis resistance seems to directly correlate with the expression level of CDCP1, when cells are cultured in suspension. However, CDCP1-negative cell line MCF7 also shows relative resistance towards loss of anchorage. Thus, anoikis resistance may not be a monocausal phenomenon. Nonetheless, high level of CDCP1-expression also promotes cell proliferation in absence of anchorage to an extracellular matrix. RNAi-mediated knock-down will elucidate if CDCP1 is also involved in cell migration or invasion. Our studies show, that CDCP1-expression level has strong impact on the capacity of breast cancer cell lines to grow and survive anchorage independent - an essential prerequisite for metastatic potential.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6167.

Electric modulation of conduction in multiferroic Ca-doped BiFeO3 films

Many interesting materials phenomena such as the emergence of high-Tc superconductivity in the cuprates and colossal magnetoresistance in the manganites arise out of a doping-driven competition between energetically similar ground states. Doped multiferroics present a tantalizing evolution of this generic concept of phase competition. Here, we present the observation of an electronic conductor-insulator transition by control of band-filling in the model antiferromagnetic ferroelectric BiFeO3 through Ca doping. Application of electric field enables us to control and manipulate this electronic transition to the extent that a p-n junction can be created, erased and inverted in this material. A 'dome-like' feature in the doping dependence of the ferroelectric transition is observed around a Ca concentration of approximately 1/8, where a new pseudo-tetragonal phase appears and the electric modulation of conduction is optimized. Possible mechanisms for the observed effects are discussed on the basis of the interplay of ionic and electronic conduction. This observation opens the door to merging magnetoelectrics and magnetoelectronics at room temperature by combining electronic conduction with electric and magnetic degrees of freedom already present in the multiferroic BiFeO3.

Observation of ferromagnetic resonance in SrRuO3 by the time-resolved magneto-optical Kerr effect

We report the observation of ferromagnetic resonance (FMR) in SrRuO3 using the time-resolved magneto-optical Kerr effect. The FMR oscillations in the time-domain appear in response to a sudden, optically induced change in the direction of easy-axis anisotropy. The high FMR frequency, 250 GHz, and large Gilbert damping parameter, alpha approximately 1, are consistent with strong spin-orbit coupling. We find that the parameters associated with the magnetization dynamics, including alpha, have a nonmonotonic temperature dependence, suggestive of a link to the anomalous Hall effect.

Animal model of metastatic pheochromocytoma: evaluation by MRI and PET

OBJECTIVE

The development of metastatic pheochromocytoma animal model provides a unique opportunity to study the physiology of these rare tumors and to evaluate experimental treatments. Here, we describe the use of small animal imaging techniques to detect, localize and characterize metastatic lesions in nude mice.

METHODS

Small animal positron emission tomography (PET) imaging and magnetic resonance imaging (MRI) were used to detect metastatic lesions in nude mice following intravenous injection of mouse pheochromocytoma cells. [18F]-6-fluoro-dopamine ([18F]-DA) and [18F]-L-6-fluoro-3,4-dihydroxyphenylalanine, which are commonly used for localization of pheochromocytoma lesions in clinical practice, were selected as radiotracers to monitor metastatic lesions by PET.

RESULTS

MRI was able to detect liver lesions as small as 0.5mm in diameter. Small animal PET imaging using [18F]-DA and [18F]-DOPA detected liver, adrenal gland, and ovarian lesions.

CONCLUSION

We conclude that MRI is a valuable technique for tumor growth monitoring from very early to late stages of tumor progression and that animal PET confirmed localization of metastatic pheochromocytoma in liver with both radiotracers.

Conduction at domain walls in oxide multiferroics

Domain walls may play an important role in future electronic devices, given their small size as well as the fact that their location can be controlled. Here, we report the observation of room-temperature electronic conductivity at ferroelectric domain walls in the insulating multiferroic BiFeO(3). The origin and nature of the observed conductivity are probed using a combination of conductive atomic force microscopy, high-resolution transmission electron microscopy and first-principles density functional computations. Our analyses indicate that the conductivity correlates with structurally driven changes in both the electrostatic potential and the local electronic structure, which shows a decrease in the bandgap at the domain wall. Additionally, we demonstrate the potential for device applications of such conducting nanoscale features.

Detection and monitoring of biofilm formation in water treatment systems by quartz crystal microbalance sensors

Investigations are presented for the development and testing of a sensor for the early stage detection and monitoring of biofilm formation. The sensor is based on the well known quartz crystal microbalance technology (QCM). The QCM detectors are integrated into the water flow system and provide continuous in-situ signals. The main objectives of the research are the evaluation of optimal operation conditions and the modification of the quartz resonator surface promoting a preferred cell attachment onto the quartz sensor surface. The miniaturization degree of the mass sensitive detector modules permits the integration into industrial plants, e.g., in order to control and ensure perfect hygienic conditions. First results of the lab study using Pseudomonas putida cultures are presented and discussed.

Identification of copy number variants associated with BPES-like phenotypes

Blepharophimosis-Ptosis-Epicanthus inversus syndrome (BPES) is a well-characterized rare syndrome that includes an eyelid malformation associated with (type I) or without premature ovarian failure (type II). Patients with typical BPES have four major characteristics: blepharophimosis, ptosis, epicanthus inversus and telecanthus. Mutations in the FOXL2 gene, encoding a forkhead transcription factor, are responsible for the majority of both types of BPES. However, many patients with BPES-like features, i.e., having at least two major characteristics of BPES, have an unidentified cause. Here, we report on a group of 27 patients with BPES-like features, but without an identified genetic defect in the FOXL2 gene or flanking region. These patients were analyzed with whole-genome high-density arrays in order to identify copy number variants (CNVs) that might explain the BPES-like phenotype. In nine out of 27 patients (33%) CNVs not previously described as polymorphisms were detected. Four of these patients displayed psychomotor retardation as an additional clinical characteristic. In conclusion, we demonstrate that BPES-like phenotypes are frequently caused by CNVs, and we emphasize the importance of whole-genome copy number screening to identify the underlying genetic causes of these phenotypes.

[Juvenile laryngeal papillomatosis--immunisation with the polyvalent vaccine gardasil]

Juvenile laryngeal papillomatosis is a rare condition caused by human papilloma virus (HPV). In cases with rapid recurrences permanent impairments of voice and breathing are almost inevitable due to the frequent need of debulking surgeries. Efforts to lower the recurrence rate comprise the adjuvant use of interferon alpha, local cidofovir, photodynamic therapy or mumps vaccination. In the present case we tried to positively influence the aggressive course of disease in a two year old boy by immunisation with the quadrivalent HPV vaccine Gardasil(R). Chromogenic in-situ hybridisation analysis and polymerase chain reaction (PCR) of lesion tissue showed simultaneous infection with the HPV-Types 6 and 11. After the third immunisation the disease became stable. No further surgery was necessary for the last ten months. The risk profile of this adjuvant treatment is low. We think it worth to initiate a multicentre trial to prove a benefit of this treatment even if no complete virus elimination can be achieved.

Anisotropy contrast in phonon-enhanced apertureless near-field microscopy using a free-electron laser

We demonstrate the imaging of ferroelectric domains in BaTiO3, using an infrared-emitting free-electron laser as a tunable optical source for scattering scanning near-field optical microscopy and spectroscopy. When the laser is tuned into the spectral vicinity of a phonon resonance, ferroelectric domains can be resolved due to the anisotropy of the dielectric properties of the material. Slight detuning of the wavelength gives rise to a contrast reversal clearly evidencing the resonant character of the excitation. The near-field domain contrast shows that the orientation of the dielectric tensor with respect to the sample surface has a clear influence on the near-field signal.

Small supernumerary marker chromosomes (sSMC) in patients with a 45,X/46,X,+mar karyotype - 17 new cases and a review of the literature

Small supernumerary marker chromosomes (sSMC) can appear in a numerically normal 'basic karyotype', but also in a numerically abnormal one like a Turner syndrome karyotype (= sSMC(T)). Here we present 17 new cases with such a mos 45,X/46,X,+mar karyotype. Moreover we reviewed all 512 cytogenetically similar cases available from the literature and supply for the first time data on occurrence, shapes and subgroups of this rare cytogenetic entity. sSMC(T) are very rare in the common population (1:100,000) - however, they can be observed with a 45- and even 60-times higher frequency in infertile and (develop)mentally retarded patients, respectively. Even though sSMC(T) derive from one of the gonosomes in >99% of the cases, there are also exceptional reports on sSMC(T) derived from one of the autosomes. The majority of sSMC(T)(X) form ring chromosomes, while most sSMC(T)(Y) are inverted duplicated/isodicentric chromosomes. Although >500 sSMC(T) are reported, a detailed characterization of the chromosomal breakpoints is only given for a minority. Thus, more cases with detailed (molecular) cytogenetic marker chromosome characterization are needed to provide information on formation and effects of an sSMC(T).

[Staging of esophageal cancer using ultrasound]

The early diagnosis of esophageal cancer is crucial for the prognosis of the disease. In contrast to cancer of the upper aerodigestive tract, the mucosa of the esophagus is not visible without the appropriate equipment. In addition to endoscopy, imaging of the esophagus is crucial for early detection of the esophageal cancer. Ultrasound of the esophagus can be performed easily and--in contrast to other imaging techniques--without side effects. Different modes of ultrasound can be performed. First, transcutaneous ultrasound allows one to detect tumors of the upper esophagus and its passage into the hypopharynx. Second, endosonography allows one to detect pathologies of the other esophageal regions including the passage into the stomach. The present review discusses the impact of both techniques against the background of the international literature.

Location and type of mutation in the LIS1 gene do not predict phenotypic severity

BACKGROUND

Lissencephaly is a neuronal migration disorder leading to absent or reduced gyration and a broadened but poorly organized cortex. The most common form of lissencephaly is isolated, referred as classic or type 1 lissencephaly. Type 1 lissencephaly is mostly associated with a heterozygous deletion of the entire LIS1 gene, whereas intragenic heterozygous LIS1 mutations or hemizygous DCX mutations in males are less common.

METHODS

Eighteen unrelated patients with type 1 lissencephaly were clinically and genetically assessed. In addition, patients with subcortical band heterotopia (n = 1) or lissencephaly with cerebellar hypoplasia (n = 2) were included.

RESULTS

Fourteen new and seven previously described LIS1 mutations were identified. We observed nine truncating mutations (nonsense, n = 2; frameshift, n = 7), six splice site mutations, five missense mutations, and one in-frame deletion. Somatic mosaicism was assumed in three patients with partial subcortical band heterotopia in the occipital-parietal lobes or mild pachygyria. We report three mutations in exon 11, including a frameshift which extends the LIS1 protein, leading to type 1 lissencephaly and illustrating the functional importance of the WD domains at the C terminus. Furthermore, we present two patients with novel LIS1 mutations in exon 10 associated with lissencephaly with cerebellar hypoplasia type a.

CONCLUSION

In contrast to previous reports, our data suggest that neither type nor position of intragenic mutations in the LIS1 gene allows an unambiguous prediction of the phenotypic severity. Furthermore, patients presenting with mild cerebral malformations such as subcortical band heterotopia or cerebellar hypoplasia should be considered for genetic analysis of the LIS1 gene.

Dietary long-chain polyunsaturated fatty acid supplementation in infants with phenylketonuria: a randomized controlled trial

BACKGROUND

Pre- and postnatal tissue accretion of long-chain polyunsaturated fatty acids (LCPUFA) has been related to visual and cognitive development in healthy children in several studies. Children with phenylketonuria (PKU) consume diets with very low contents of preformed LCPUFA. We studied prospectively the LCPUFA status in infants with PKU without or with LCPUFA supplementation during the first year of life.

SUBJECTS AND METHODS

Infants with PKU were enrolled at diagnosis (<4 weeks of age) and randomized double blind to phenylalanine-free amino acid supplements without LCPUFA (n = 11) or with both arachidonic (AA, 0.46 wt%) and docosahexaenoic acids (DHA, 0.27 wt%) (n = 10). At enrolment and again at 1, 2, 3, 4, 6, 9 and 12 months, plasma phospholipid fatty acids were measured and dietary intakes were calculated from dietary protocols.

RESULTS

Unsupplemented patients showed a marked LCPUFA depletion to levels clearly below those observed in healthy breast-fed infants. In contrast, supplemented infants had stable and higher LCPUFA levels than unsupplemented infants, reaching significant differences for AA values at 3, 4 and 6 months, and for DHA values at 1, 3, 4, 6, 9 and 12 months. Plasma phospholipid levels correlated closely with estimated dietary intakes of preformed LCPUFA.

CONCLUSION

Low LCPUFA intakes with PKU diets induce marked depletion of AA and particularly of DHA in the first year of life. Thus endogenous synthesis of LCPUFA from precursors supplied by diet seems unable to compensate for low LCPUFA intakes. LCPUFA supplementation of PKU diets during the first year of life effectively enhances LCPUFA status to levels comparable to those of healthy breast-fed infants.

Successful bone marrow transplantation in a patient with DNA ligase IV deficiency and bone marrow failure

BACKGROUND

DNA Ligase IV deficiency syndrome is a rare autosomal recessive disorder caused by hypomorphic mutations in the DNA ligase IV gene (LIG4). The clinical phenotype shows overlap with a number of other rare syndromes, including Seckel syndrome, Nijmegen breakage syndrome, and Fanconi anemia. Thus the clinical diagnosis is often delayed and established by exclusion.

METHODS

We describe a patient with pre- and postnatal growth retardation and dysmorphic facial features in whom the diagnoses of Seckel-, Dubowitz-, and Nijmegen breakage syndrome were variably considered. Cellular radiosensitivity in the absence of clinical manifestations of Ataxia telangiectasia lead to the diagnosis of DNA ligase IV (LIG4) deficiency syndrome, confirmed by compound heterozygous mutations in the LIG4 gene. At age 11, after a six year history of progressive bone marrow failure and increasing transfusion dependency the patient was treated with matched sibling donor hematopoietic stem cell transplantation (HSCT) using a fludarabine-based conditioning regimen without irradiation.

RESULTS

The post-transplantation course was uneventful with rapid engraftment leading to complete and stable chimerism. Now at age 16, the patient has gained weight and is in good clinical condition.

CONCLUSION

HSCT using mild conditioning without irradiation qualifies as treatment of choice in LIG4-deficient patients who have a matched sibling donor.

M. Gaucher, M. Fabry und Mukopolysaccharidose Typ I

The lysosomal storage diseases Gaucher disease, Fabry disease and MPS I are rare inheritable metabolic disorders that are now treatable with enzyme replacement therapy. In order to avoid irreversible complications, an early diagnosis and initiation of therapy is important. Due to the musculoskeletal symptoms associated with these storage diseases, patients are likely to visit a rheumatologist, who should, therefore, be able to recognise and diagnose these rare diseases. On the basis of the causal factors behind Gaucher disease, Fabry disease und MPS I (here Scheie syndrome), key symptoms that the rheumatologist (internist or paediatrician) should be familiar with for the differential diagnosis of these patients will be discussed. In addition, a short introduction to the pathophysiology and data on the prognosis and therapy for these diseases will be presented.