bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of probe-to-probe approach method for an independently controlled dual-probe scanning tunneling microscope
Authors: Matsui Atsuteru , Shigeta Yukichi
Published: October 2007

We developed a method of fast probe-to-probe approach for an independently controlled dual-probe scanning tunneling microscope (STM), which is essential to measure the transport property of nanostructures, without scanning electron microscopy (SEM). In the approach method, inchworm motors are used as the coarse positioning devices, which are controlled with a personal computer. The method enables an automatic approach of the probe to the other probe within a short time (typically 30min). After the approach, a real distance between contact points of each probe tip to a sample can be measured from the overlapped part of the STM images obtained with individual probe. The approach method without SEM is also useful to measure the charge transport in the atmosphere, which will be essential for measurement of the bio molecules.
Electrical resistivity of ultrafine-grained copper with nanoscale growth twins
Authors: Chen X. H. , Lu L. , Lu K.
Published: October 2007

We have investigated electrical resistivities of high-purity ultrafine-grained Cu containing different concentrations of nanoscale growth twins, but having identical grain size. The samples were synthesized by pulsed electrodeposition, wherein the density of twins was varied systematically by adjusting the processing parameters. The electrical resistivity of the Cu specimen with a twin spacing of 15nm at room temperature (RT) is 1.75μΩcm (the conductivity is about 97% IACS), which is comparable to that of coarse-grained (CG) pure Cu specimen. A reduction in twin density for the same grain size (with twin lamellar spacings of 35 and 90nm, respectively) results in an increment in electrical resistivity from 1.75to2.12μΩcm. However, the temperature coefficient of resistivity at RT for these Cu specimens is insensitive to the twin spacing and shows a consistent value of ∼3.78×10−3∕K, which is slightly smaller than that of CG Cu (3.98×10−3∕K). The increased electrical resistivities of the Cu samples were ascribed dominantly to the intrinsic grain boundary (GB) scattering, while the GB defects and GB energy would decrease with increasing twin density. Transmission electron microscope observations revealed the GB configuration difference from the Cu samples with various twin densities. Plastic deformation would induce an apparent increase in the resistivity. The higher of the twin density, the higher increment of RT resistivity was detected in the Cu specimens subjected to 40% rolling strain. Both the deviated twin boundaries and strained GBs may give rise to an increase in the resistivity.
From gas-liquid to liquid crystalline phase behavior via anisotropic attraction: A computer simulation study
Authors: Ouyang Wen-Ze , Hentschke Reinhard
Published: October 2007

The partial phase behavior of a continuum molecular model for self-assembling semiflexible equilibrium polymers is studied via Monte Carlo and molecular dynamics simulation. We investigate the transfer from ordinary gas-liquid coexistence to the appearance of liquid crystallinity driven by excluded volume interaction between rodlike aggregates. The transfer between the two types of phase behavior is governed by a tunable anisotropic attractive interaction between monomer particles. The relation to dipolar fluid models, which are also known to form reversible chains, is discussed.
Effects of aging on the 1∕f noise of metal-oxide-semiconductor field effect transistors
Authors: Zhou X. J. , Fleetwood D. M. , Danciu I. , Dasgupta A. , Francis S. A. , Touboul A. D.
Published: October 2007

The 1∕f noise magnitude of n-channel metal-oxide-semiconductor field effect transistors is found to decrease by up a factor of ∼3 after 18years of room-temperature aging. This decrease is largest in devices with high-temperature post-gate-oxidation N2 annealing, which increases the densities of O vacancies and strained Si–Si bonds near the Si∕SiO2 interface. Approximately 100mV positive threshold voltage shifts are observed for all device types during aging. These results suggest that the aging related changes in 1∕f noise may well be caused by the relaxation of strained Si–Si bonds associated with O vacancies in the near-interfacial SiO2.
Specific and efficient adsorption of phosphorothioated DNA on Au-based surfaces and electrodes
Authors: Ghabboun Jamal , Sowwan Mukhles , Cohen Hezy , Molotsky Tatiana , Borovok Natalia , Dwir Benjamin , Kapon Eli , Kotlyar Alexander , Porath Danny
Published: October 2007

Efficient attachment of DNA to metal surfaces or electrodes is essential for charge-transport measurements, scanning tunneling microscopy, and for devices and sensors. To optimize DNA deposition on Au-based surfaces and electrodes, we synthesized DNA with phosphorothioate (PT) groups attached to the G strand of poly(deoxyguanine)-poly(deoxycytosine) [poly(dG)-poly(dC)]. This procedure strongly improves the DNA anchoring to Au-based surfaces by sulfur-gold interaction. Much higher molecular surface density on Au substrates was observed for PT poly(dG)-poly(dC) compared to “bare” molecules. Deposition of PT poly(dG)-poly(dC) on Au-based electrodes, followed by thorough washing, showed that they specifically attach to the electrodes and are not spread on the surrounding SiO2 surface.
Controlling enhanced transmission through metallic gratings with subwavelength slits by anisotropic waveguide resonance
Authors: Fong King-Yan , Hui P. M.
Published: October 2007

We propose an analytically tractable structure for controlling enhanced transmission through a metallic grating with subwavelength slits by filling the slits with an anisotropic material such as a liquid crystal. As the director rotates, the Fabry-Pérot condition is modified and the transmission peaks shift. Analytical results of a single-mode theory for the propagation constant, transmission efficiency, and the tunable range of peak wavelengths are given, taking the finite conductivity of metal into account. Analytical results are in good agreement with those calculated by the rigorous coupled-wave analysis, indicating that waveguide resonance plays a dominant role and the results are scalable.
High responsivity of GaN p-i-n photodiode by using low-temperature interlayer
Authors: Lin J. C. , Su Y. K. , Chang S. J. , Lan W. H. , Huang K. C. , Chen W. R. , Huang C. Y. , Lai W. C. , Lin W. J. , Cheng Y. C.
Published: October 2007

Gallium nitride p-i-n ultraviolet photodiodes with low-temperature (LT)-GaN interlayer have been fabricated. It was found that the dark current of photodiode with LT-GaN interlayer is as small as 143pA at 5V reverse bias. It was also found that the responsivity of the photodiode with LT-GaN interlayer can be enhanced at a small electric field (∼0.4MV∕cm) due to the carrier multiplication effect. The UV photocurrent gain of 13 and large ionization coefficient (α=3.1×105cm−1) were also observed in the detector with LT-GaN interlayer. Furthermore, we can achieve a large peak responsivity of 2.27A∕W from the photodiode with LT-GaN interlayer.
Ferroelectricity of multiferroic hexagonal TmMnO3 ceramics synthesized under high pressure
Authors: Wang L. J. , Feng S. M. , Zhu J. L. , Yu R. C. , Jin C. Q. , Yu W. , Wang X. H. , Li L. T.
Published: October 2007

Dense hexagonal TmMnO3 ceramics were synthesized by solid-state reaction technique combined with high-pressure treatment which significantly increased the density of ceramic samples. The crystal structure of the hexagonal TmMnO3 oxide was refined by using Rietveld analysis based on powder x-ray diffraction experiment. We observed obvious dielectric peaks through dielectric measurement on the specimen subjected to postannealing in oxygen atmosphere. A ferroelectric-paraelectric transition around 348°C is identified. Polarization-electric field hysteresis (P-E) loop measurement proved the ferroelectricity of the sample at room temperature.
Structure-intact TiO2 nanoparticles for efficient electron transport in dye-sensitized solar cells
Authors: Wang Kai-Ping , Teng Hsisheng
Published: October 2007

Ti O 2 anatase nanoparticles were synthesized from a titanate for application in dye-sensitized solar cells. Structural analysis with x-ray absorption fine structure spectroscopy showed that this titanate-derived TiO2 had a low density of oxygen-vacancy defects that would serve as the trap sites to impede electron transport. The transit time of the photogenerated electrons, measured by intensity modulated photocurrent spectroscopy, was significantly shorter in the titanate-derived TiO2 than in the conventional sol-gel-derived TiO2. This structure-intact feature of the titanate-derived TiO2 has led to a high photocurrent for dye-sensitized solar cells.
Electrical properties of air-stable, iodine-doped carbon-nanotube–polymer composites
Authors: Sankapal Babasaheb R. , Setyowati Kristina , Chen Jian , Liu Haiying
Published: October 2007

We report the preparation and electrical characterization of air-stable, iodine-doped single-walled carbon nanotube (SWNT)–polymer composites, which show significant enhancement in electrical conductivity by a factor of 2–5 as compared to undoped SWNT-polymer composites. The analysis of temperature dependent conductivity data reveals that the conduction of iodine-doped SWNT composites can be well described by the thermal-fluctuation-induced tunneling model. The observed substantial conductivity enhancement in iodine-doped SWNT composites can be attributed to two factors: the higher conductivity of doped SWNTs and the smaller insulating polymer barriers between adjacent conductive SWNTs.
Study of micropipe structure in SiC by x-ray phase contrast imaging
Authors: Kohn V. G. , Argunova T. S. , Je Jung Ho
Published: October 2007

Phase contrast images of dislocation micropipe in SiC crystal are experimentally studied at various distances from the sample using synchrotron white beam. Computer simulation of these images enabled us to understand the peculiarities of image formation and measure the diameter of the micropipe. The phase contrast imaging of micropipes without monochromator is explained by the absorption of x rays in a thick (490μm) SiC crystal, effectively forming a high brilliance radiation spectrum with a pronounced maximum at 16keV.
On the ion and neutral atom bombardment of the growth surface in magnetron plasma sputter deposition
Authors: van Hattum E. D. , Palmero A. , Arnoldbik W. M. , Rudolph H. , Habraken F. H. P. M.
Published: October 2007

The energy distribution of positive argon ions bombarding the substrate during radiofrequency magnetron sputter deposition has been measured as a function of the argon pressure. The results are related to measurements of the plasma potential distribution and understood invoking the occurrence of resonant charge transfer reactions. This effectively lowers the ion bombardment energy and causes the bombardment of the growth surface with neutrals of a few eV kinetic energy in the pressure range of 0.1–1Pa.
Reversible electric field induced nonferroelectric to ferroelectric phase transition in single crystal nanorods of potassium nitrate
Authors: Yadlovker Doron , Berger Shlomo
Published: October 2007

Single-crystal rods of the α-phase of potassium nitrate were grown with [010] uniform crystallographic orientation inside a matrix of aluminum oxide nanopores. The pores were prepared by anodization of polished aluminum substrates. The potassium nitrate single crystals were grown inside the pores from a supersaturated aqueous solution at various temperatures. Dielectric polarization measurements of the porous film filled with the potassium nitrate crystals show an electric field induced reversible transition from the nonferroelectric α-phase to the ferroelectric γ-phase at about 200kV∕cm. The ferroelectric γ-phase has a coercive field of about 169kV∕cm and remnant polarization of about 0.216μC∕cm2.
Toward organic thick film solar cells: Three dimensional bulk heterojunction organic thick film solar cell using fullerene single crystal nanorods
Authors: Somani Prakash R. , Somani Savita P. , Umeno Masayoshi
Published: October 2007

Fullerene single crystal nanorods (C60-nanorods) are synthesized by simple liquid/liquid interface precipitation method. Three dimensional bulk heterojunction donor-acceptor-type organic thick film solar cell is demonstrated having an active layer made from C60-nanorods and regioregular poly(3-octylthiophene). C60-nanorods seem to be promising material for organic solar cell applications. Our preliminary results opens an area of “organic thick film solar cells” which was almost thought to be impossible due to lower mobility of charge carriers and small exciton diffusion lengths in most of the organic materials, including small molecules and conjugated polymers.
A mean-field scaling method for first- and second-order phase transition ferromagnets and its application in magnetocaloric studies
Authors: Amaral J. S. , Silva N. J. O. , Amaral V. S.
Published: October 2007

We present a method based on mean-field theory, where from scaling of experimental magnetization data, the mean-field exchange parameter λ and the f function of the equation of state M=f[(H+Hexch)∕T] are directly determined. The scaling approach allows finding the dependence of Hexch on T or higher powers of M, which determine the order of the phase transition. Within the thermodynamics of the mean-field theory, the magnetocaloric effect is obtained, in a straightforward way, from the magnetic equation of state. Results are presented for first- and second-order magnetic phase transitions in manganites and metastable nanocrystalline metal alloy.
The spin polarization of CrO2 revisited
Authors: Yates K. A. , Branford W. R. , Magnus F. , Miyoshi Y. , Morris B. , Cohen L. F. , Sousa P. M. , Conde O. , Silvestre A. J.
Published: October 2007

Here, we use Andreev reflection spectroscopy to study the spin polarization of high quality CrO2 films. We study the spin polarization as a function of growth temperature, resulting in grain size and electrical resistivity. In these films low temperature growth appears to be a necessary but not sufficient condition to guarantee the observation of high spin polarization, and this is only observed in conjunction with suppressed superconducting gap values and anomalously low interface properties. We suggest that this combination of observations is a manifestation of the long range spin triplet proximity effect.
Modulation of negative index metamaterials in the near-IR range
Authors: Kim Evgenia , Shen Y. Ron , Wu Wei , Ponizovskaya Ekaterina , Yu Zhaoning , Bratkovsky Alexander M. , Wang Shih-Yuang , Williams R. Stanley
Published: October 2007

Optical modulation of the effective refractive properties of a “fishnet” metamaterial with a Ag∕Si∕Ag heterostructure is demonstrated in the near-IR range and the associated fast dynamics of negative refractive index is studied by pump-probe method. Photoexcitation of the amorphous Si layer at visible wavelength and corresponding modification of its optical parameters is found to be responsible for the observed modulation of negative refractive index in near-IR.
Anomalous photocurrent observed in an Fe–ZnS:Fe Schottky diode
Authors: Li B. K. , Wang C. , Sou I. K. , Ge W. K. , Wang J. N.
Published: October 2007

Anomalous photocurrent was observed in an epitaxial Fe∕Zn0. 96Fe0. 04S Schottky diode grown by molecular beam epitaxy. The temperature dependent decay behavior of the anomalous photocurrent has been studied. A model based on the photoionization of the acceptorlike interface states is proposed to explain this anomalous phenomenon. By fitting the decay curves of the anomalous photocurrent at different temperatures, ionization energy of the interface states is obtained from an Arrhenius plot of the decay time constants. We believe that these interface states are associated with some complex (Fe, S) defects formed at the Fe∕ZnFeS interface.
Crystal structure of human intrinsic factor: Cobalamin complex at 2.6-Å resolution
Authors: Mathews F. S. , Gordon M. M. , Chen Z. , Rajashankar K. R. , Ealick S. E. , Alpers D. H. , Sukumar N.
Published: October 2007

The structure of intrinsic factor (IF) in complex with cobalamin (Cbl) was determined at 2.6-Å resolution. The overall fold of the molecule is that of an α6/α6barrel. It is a two-domain protein, and the Cbl is bound at the interface of the domains in a base-on conformation. Surprisingly, two full-length molecules, each comprising an α- and a β-domain and one Cbl, and two truncated molecules with only an α- domain are present in the same asymmetric unit. The environment around Cbl is dominated by uncharged residues, and the sixth coordinate position of Co2+is empty. A detailed comparison between the IF-B12 complex and another Cbl transport protein complex, trans-Cbl-B12, has been made. The pH effect on the binding of Cbl analogues in transport proteins is analyzed. A possible basis for the lack of interchangeability of human and rat IF receptors is presented.
High-resolution imaging of the dynamic tumor cell–vascular interface in transparent zebrafish
Authors: Stoletov Konstantin , Montel Valerie , Lester Robin D. , Gonias Steven L. , Klemke Richard
Published: October 2007

Cell metastasis is a highly dynamic process that occurs in multiple steps. Understanding this process has been limited by the inability to visualize tumor cell behavior in real time by using animal models. Here, we employ translucent zebrafish and high-resolution confocal microscopy to study how human cancer cells invade in tissues, induce angiogenesis, and interact with newly formed vessels. We use this system to study how the human metastatic geneRhoCpromotes the initial steps of metastasis. We find thatRhoCexpression induces a primitive amoeboid-like cell invasion characterized by the formation of dynamic membrane protrusions and blebs. Surprisingly, these structures penetrate the blood vessel wall exclusively at sites of vascular remodeling and not at regions of existing intact vessels. This process requires tumor cells to secrete VEGF, which induces vascular openings, which in turn, serve as portholes allowing access ofRhoC-expressing cells to the blood system. Our results support a model in which the early steps in intravasation and metastasis require two independent events: (i) dynamic regulation of the actin/myosin cytoskeleton within the tumor cell to form protrusive structures and (ii) vascular permeablization and vessel remodeling. The integration of zebrafish transgenic technology with human cancer biology may aid in the development of cancer models that target specific organs, tissues, or cell types within the tumors. Zebrafish could also provide a cost-effective means for the rapid development of therapeutic agents directed at blocking human cancer progression and tumor-induced angiogenesis.
Real-time imaging of β-catenin dynamics in cells and living mice
Authors: Naik Snehal , Piwnica-Worms David
Published: October 2007

β-Catenin (β-cat) is a key signaling component of the canonical Wnt pathway as well as an increasingly studied contributor to various pathways that regulate cell adhesion, proliferation, and differentiation. For its best known function, posttranslational stabilization of β-cat is required for T cell factor-dependent transcription of numerous downstream targets of Wnt, and this process is aberrantly active in a wide array of cancers. To enable direct monitoring of posttranslational stabilization of β-cat in cells and living animals, we constructed and characterized the bioluminescent fusion reporters β-cat firefly luciferase (β-cat-FLuc) and β-cat click beetle green luciferase (β-cat-CBG). These reporters provided real-time, noninvasive readout of modulators of β-cat stability
in cellulo
and, furthermore, enabled monitoring of changes in total β-cat levels
in vivo
in intact animals. In addition, using spectral unmixing, green β-cat-CBG was deconvoluted from a red TCF-dependent FLuc reporter (TOPFLASH), enabling analysis of β-cat processing and downstream transcriptional activation simultaneously. By using this system, the natural product epigallocatechin 3-gallate was found to block Wnt signaling, independent of β-cat processing. These β-cat reporters represent a powerful new strategy for identifying
in cellulo
and
in vivo
dynamic regulators and mechanism-based therapeutics of signaling pathways mediated by β-cat stabilization.
The SCF
Cdc4
ubiquitin ligase regulates calcineurin signaling through degradation of phosphorylated Rcn1, an inhibitor of calcineurin
Authors: Kishi Tsutomu , Ikeda Akemi , Nagao Rina , Koyama Noriko
Published: October 2007

The highly conserved RCN family of proteins regulates the serine/threonine protein phosphatase calcineurin, which is required for the expression of genes involved in Ca
2+
-dependent processes, such as the control of memory, apoptosis, T cell activation, cell cycle, Ca
2+
-homeostasis, and skeletal and cardiac muscle growth and differentiation. However, RCNs regulate calcineurin through two paradoxical actions: they act as feedback inhibitors of calcineurin, whereas their phosphorylation stimulates calcineurin. Here we show that phosphorylation of yeast RCN, Rcn1, triggers degradation through the SCF
Cdc4
ubiquitin ligase complex. Degradation of phosphorylated Rcn1 is required to mitigate inhibition of calcineurin by Rcn1 and results in activation of calcineurin activity in response to Ca
2+
as well as in reactivation of calcineurin in response to changes in Ca
2+
concentration. The SCF
Cdc4
-dependent degradation required phosphorylation of Rcn1 by Mck1, a member of the GSK3 family of protein kinases, and was promoted by Ca
2+
. However, such degradation was counteracted by dephosphorylation of Rcn1, which was promoted by Ca
2+
-stimulated calcineurin. Thus, calcineurin activity is fine-tuned to Ca
2+
signals by mechanisms that have opposite functions. Our results identify the molecular mechanism of Rcn1 phosphorylation-induced stimulation of the phosphatase activity of calcineurin. The results provide insight into the mechanism involved in maintaining proper responses to Ca
2+
signals.
Reevaluation of telomerase inhibition by quadruplex ligands and their mechanisms of action
Authors: De Cian Anne , Cristofari Gael , Reichenbach Patrick , De Lemos Elsa , Monchaud David , Teulade-Fichou Marie-Paule , Shin-ya Kazuo , Lacroix Laurent , Lingner Joachim , Mergny Jean-Louis
Published: October 2007

Quadruplex ligands are often considered as telomerase inhibitors. Given the fact that some of these molecules are present in the clinical setting, it is important to establish the validity of this assertion. To analyze the effects of these compounds, we used a direct assay with telomerase-enriched extracts. The comparison of potent ligands from various chemical families revealed important differences in terms of effects on telomerase initiation and processivity. Although most quadruplex ligands may lock a quadruplex-prone sequence into a quadruplex structure that inhibits the initiation of elongation by telomerase, the analysis of telomerase-elongation steps revealed that only a few molecules interfered with the processivity of telomerase (i.e., inhibit elongation once one or more repeats have been incorporated). The demonstration that these molecules are actually more effective inhibitors of telomeric DNA amplification than extension by telomerase contributes to the already growing suspicion that quadruplex ligands are not simple telomerase inhibitors but, rather, constitute a different class of biologically active molecules. We also demonstrate that the popular telomeric repeat amplification protocol is completely inappropriate for the determination of telomerase inhibition by quadruplex ligands, even when PCR controls are included. As a consequence, the inhibitory effect of many quadruplex ligands has been overestimated.
Murine models of acute neuronopathic Gaucher disease
Authors: Enquist Ida Berglin , Bianco Christophe Lo , Ooka Andreas , Nilsson Eva , Månsson Jan-Eric , Ehinger Mats , Richter Johan , Brady Roscoe O. , Kirik Deniz , Karlsson Stefan
Published: October 2007

Gaucher disease (GD) is an autosomal recessive lysosomal storage disorder caused by mutations in the glucosidase, beta, acid (GBA) gene that encodes the lysosomal enzyme glucosylceramidase (GCase). GCase deficiency leads to characteristic visceral pathology and, in some patients, lethal neurological manifestations. Here, we report the generation of mouse models with the severe neuronopathic form of GD. To circumvent the lethal skin phenotype observed in several of the previous GCase-deficient animals, we genetically engineered a mouse model with strong reduction in GCase activity in all tissues except the skin. These mice exhibit rapid motor dysfunction associated with severe neurodegeneration and apoptotic cell death within the brain, reminiscent of neuronopathic GD. In addition, we have created a second mouse model, in which GCase deficiency is restricted to neural and glial cell progenitors and progeny. These mice develop similar pathology as the first mouse model, but with a delayed onset and slower disease progression, which indicates that GCase deficiency within microglial cells that are of hematopoietic origin is not the primary determinant of the CNS pathology. These findings also demonstrate that normal microglial cells cannot rescue this neurodegenerative disease. These mouse models have significant implications for the development of therapy for patients with neuronopathic GD.
Impaired hippocampal rhythmogenesis in a mouse model of mesial temporal lobe epilepsy
Authors: Dugladze Tamar , Vida Imre , Tort Adriano B. , Gross Anna , Otahal Jacub , Heinemann Uwe , Kopell Nancy J. , Gloveli Tengis
Published: October 2007

Mesial temporal lobe epilepsy (mTLE) is one of the most common forms of epilepsy, characterized by hippocampal sclerosis and memory deficits. Injection of kainic acid (KA) into the dorsal hippocampus of mice reproduces major electrophysiological and histopathological characteristics of mTLE. In extracellular recordings from the morphologically intact ventral hippocampus of KA-injected epileptic mice, we found that theta-frequency oscillations were abolished, whereas gamma oscillations persisted both
in vivo
and
in vitro
. Whole-cell recordings further showed that oriens-lacunosum-moleculare (O-LM) interneurons, key players in the generation of theta rhythm, displayed marked changes in their intrinsic and synaptic properties. Hyperpolarization-activated mixed cation currents (Ih) were significantly reduced, resulting in an increase in the input resistance and a hyperpolarizing shift in the resting membrane potential. Additionally, the frequency of spontaneous excitatory postsynaptic currents (sEPSCs) was increased, indicating a stronger excitatory input to these neurons. As a consequence, O-LM interneurons increased their firing rate from theta to gamma frequencies during induced network activity in acute slices from KA-injected mice. Thus, our physiological data together with network simulations suggest that changes in excitatory input and synaptic integration in O-LM interneurons lead to impaired rhythmogenesis in the hippocampus that in turn may underlie memory deficit.
Positron emission tomography (PET) imaging of neuroblastoma and melanoma with
64
Cu-SarAr immunoconjugates
Authors: Voss Stephan D. , Smith Suzanne V. , DiBartolo Nadine , McIntosh Lacey J. , Cyr Erika M. , Bonab Ali A. , Dearling Jason L. J. , Carter Edward A. , Fischman Alan J. , Treves S. Ted , Gillies Stephen D. , Sargeson Alan M. , Huston James S. , Packard Alan B.
Published: October 2007

The advancement of positron emission tomography (PET) depends on the development of new radiotracers that will complement
18
F-FDG. Copper-64 (
64
Cu) is a promising PET radionuclide, particularly for antibody-targeted imaging, but the high
in vivo
lability of conventional chelates has limited its clinical application. The objective of this work was to evaluate the novel chelating agent SarAr (1-
N
-(4-aminobenzyl)-3, 6,10,13,16,19-hexaazabicyclo[6.6.6] eicosane-1,8-diamine) for use in developing a new class of tumor-specific
64
Cu radiopharmaceuticals for imaging neuroblastoma and melanoma. The anti-GD2 monoclonal antibody (mAb) 14.G2a, and its chimeric derivative, ch14.18, target disialogangliosides that are overexpressed on neuroblastoma and melanoma. Both mAbs were conjugated to SarAr using carbodiimide coupling. Radiolabeling with
64
Cu resulted in >95% of the
64
Cu being chelated by the immunoconjugate. Specific activities of at least 10 μCi/μg (1 Ci = 37 GBq) were routinely achieved, and no additional purification was required after
64
Cu labeling. Solid-phase radioimmunoassays and intact cell-binding assays confirmed retention of bioactivity. Biodistribution studies in athymic nude mice bearing s.c. neuroblastoma (IMR-6, NMB-7) and melanoma (M21) xenografts showed that 15–20% of the injected dose per gram accumulated in the tumor at 24 hours after injection, and only 5–10% of the injected dose accumulated in the liver, a lower value than typically seen with other chelators. Uptake by a GD2-negative tumor xenograft was significantly lower (<5% injected dose per gram). MicroPET imaging confirmed significant uptake of the tracer in GD-2-positive tumors, with minimal uptake in GD-2-negative tumors and nontarget tissues such as liver. The
64
Cu-SarAr-mAb system described here is potentially applicable to
64
Cu-PET imaging with a broad range of antibody or peptide-based imaging agents.
Identification of differentially expressed proteins in ovarian cancer using high-density protein microarrays
Authors: Hudson Michael E. , Pozdnyakova Irina , Haines Kenneth , Mor Gil , Snyder Michael
Published: October 2007

Ovarian cancer is a leading cause of deaths, yet many aspects of the biology of the disease and a routine means of its detection are lacking. We have used protein microarrays and autoantibodies from cancer patients to identify proteins that are aberrantly expressed in ovarian tissue. Sera from 30 cancer patients and 30 healthy individuals were used to probe microarrays containing 5,005 human proteins. Ninety-four antigens were identified that exhibited enhanced reactivity from sera in cancer patients relative to control sera. The differential reactivity of four antigens was tested by using immunoblot analysis and tissue microarrays. Lamin A/C, SSRP1, and RALBP1 were found to exhibit increased expression in the cancer tissue relative to controls. The combined signals from multiple antigens proved to be a robust test to identify cancerous ovarian tissue. These antigens were also reactive with tissue from other types of cancer and thus are not specific to ovarian cancer. Overall our studies identified candidate tissue marker proteins for ovarian cancer and demonstrate that protein microarrays provide a powerful approach to identify proteins aberrantly expressed in disease states.
From “Post-” to “Post-Post-” and Back. Quid Tum?
Authors: H. R. H.
Published: October 2007

“What next?” may not be an untimely question to ask as the map-makers scramble to keep up with the rush of events cascading a myriad of changes upon these custodians of the here and now. No sooner have they marked a new revision of a border, noted the latest alteration of a name or shift of a capital, than yet another tremor forces them to print anew a further updated edition to reflect the consequences of the most recent shock wave to effect an ever shorter status quo. Long gone are the days of Soviet “stability,” so long, in fact, that it is time to take stock and answer the gnawing question “Where are we?” more accurately than with the increasingly vague “In the ‘post-Soviet’ period.” “Quid tum? What next?” deserves a more precise reply.
In Memoriam: Donald W. Treadgold (1922–1994): Teacher, Scholar, Humanist
Authors: Huttenbach Henry R.
Published: October 2007

Don—by which name I knew him since I became his graduate student in 1956—belonged to a rare breed of academicians: he was a devout man for whom the personal adventure of life and human history in its totality had a moral dimension; in his quest for understanding himself and others, there was always an underlying moral drama; there was not just the realm of the true and the false but also a fundamental layer of the right and the wrong. For Don, there was always the issue of good and evil. In the end, men and women, the lofty, such as Stolypin (about whom he wrote insightfully), and the humble, such as the Russian peasants in Siberia (to whom he also gave considerable scholarly attention), all were accountable for their individual and collective actions. We are all free moral agents, he observed, including Lenin (about whose early political struggles he wrote brilliantly). It is a perspective Don never abandoned as the Soviet Union dissolved into the amorphous and morally complex post-Soviet era, a characteristic which qualified Don as a persistent humanist. The individual human person endowed with the capacity to sustain immutable moral values was Don's ultimate interest as an historian and teacher.
Ethnic Mobilization and Reactive Nationalism: The Case of Moldova
Authors: Chinn Jeff , Roper Steven D.
Published: October 2007

1. Introduction

Until the October 1991 Soviet coup, Moldova, previously known as Bessarabia and the Moldavian Soviet Socialist Republic, had known independence only briefly, having been part of the Russian Empire, Romania, or the Soviet Union for almost its entire history. As a result of shifting foreign influences and borders, Moldova, like most modern political entities, has a multiethnic population. The conflicting perspectives and demands of Moldova's different ethnic groups underlie many of today's controversies.
Two Strategies in Serbian Politics in Croatia and Hungary before the First World War
Authors: Miller Nicholas
Published: October 2007

With the recent attention given to the breakup of Yugoslavia, it is important to emphasize that the Serbs of Croatia and Hungary have always feared, rightly or wrongly, for their cultural, economic, and physical existence. The most prominent Serbian political parties in the nineteenth and early twentieth centuries in the Habsburg monarchy staked their reputations on their ability to defend the Serbian nation from cultural assimilation. The parties examined in this article were no exception. They believed that their primary task was to assure the continued existence of a Serbian nationality in Croatia and Hungary. In this article, the politics surrounding the Serbian Orthodox church in the Habsburg monarchy will provide the framework for an analysis and comparison of the political strategies of the two largest Serbian parties in Croatia and Hungary, the Independent and Radical parties.
Territorial and Demographic Foundations of Komi-Permiak Nationality
Authors: Lallukka Seppo
Published: October 2007

The Komi-Permiaks and Their Homeland

According to the Soviet 1989 census, there was a total of 496,600 Komis in the USSR. The nationality is composed of two main groups, closely related to each other ethnically, culturally and linguistically: the Komi-Zyrians and the Komi-Permiaks. The former are numerically larger, amounting to 344,500 in 1989, while the latter numbered 152,100. The status of the two as distinct ethnic groups is still debated, but in terms of territorial administration the two groups have been treated separately. The Komi-Zyrians have the Komi Republic as their titular unit, whereas the autonomy of the Komi-Permiaks is of lower rank, an autonomousokrug(area) within the Perm’ province. In line with the administrative separation, Soviet language planners classified the two groups’ languages as distinct ones.
The Basmachi Movement From Within: An Account of Zeki Velidi Togan
Authors: Paksoy H. B.
Published: October 2007

J. V. Stalin, in his 1923 denunciation of Sultan Galiev, formerly Stalin's own assistant in Narkomnats, stated:

I accused him (Sultan Galiev) of creating an organization of the Validov type … despite that, a week later, he sent … a secret letter … to establish contact with the Basmachi and with their leader Validov.
Ethnic Minorities (Russians) in Lithuania
Authors: Statteika E.
Published: October 2007

The social status of ethnic minorities residing in a state is one indicator of the level of democracy in each newly formed or restored democratic society.
The Zhirinovsky Electoral Victory: Antecedence and Aftermath
Authors: Clark Terry D.
Published: October 2007

The December 1993 elections to the new lower house of the Russian legislature, the State Duma, resulted in a large number of seats going to parties and movements opposed to the Yeltsin reforms. Most dismaying for the democrats, however, was the attainment of seventy seats by the Liberal-Democratic Party (LDP) headed by ultranationalist Vladimir Zhirinovsky. As a consequence, the progress of economic and political reform was undermined, Yeltsin having been denied the mandate which he sought with the dissolution of the Supreme Soviet in October.
Economic Nationalism Among German Bohemians
Authors: Albrecht Catherine
Published: October 2007

Economic nationalism was an important element of political conflict between Czechs and Germans in Bohemia. As the Czechs developed their own (avowedly national) industrial and financial base, they not only competed with the Germans in an economic sense, but they also challenged German Bohemians' prominence in business associations and in local and provincial government. While the Czechs embraced an “optimism of work,” German Bohemians felt a need to defend their economic superiority.
Choosing Czech Identity in Nineteenth-Century Prague: the Case of Jindřich Fügner
Authors: Nolte Claire E.
Published: October 2007

Jindřich (Heinrich) Fügner played a significant role in the evolution of Czech national culture in the nineteenth century. As the first President, orstarosta, of the Sokol (Falcon), the Czech gymnastic club that was modeled on the older GermanTurnvereinmovement, he worked together with the club's Gymnastic Director, Miroslav Tyrš, to build the foundations of the most successful Czech nationalist organization of the nineteenth century. A prominent and respected figure in the society of mid-century Prague, he was also somewhat of an anomaly, a German businessman who abandoned the status that his wealth and national origin conferred to cross-over to a Czech identity. Although such conversions evoke images of “national promiscuity” or “national transvestitism” in the modern world, where national identity is viewed as inevitable, they were not uncommon in nineteenth-century Prague, and Fügner's choice was unusual only because it was not motivated by a desire for social advancement or economic opportunity. Rather, in a world where political expression was limited, it appears as a statement of personal values and ideological conviction whose motives must be sought not in material concerns, rather in the more abstract regions of the soul.
The Expulsion of the Sudeten Germans: 1945-1952
Authors: Smelser Ronald M.
Published: October 2007

For over 700 years Czechs and Germans lived together in those lands which in this century would be consolidated as Czechoslovakia. It was not always a harmonious existence, but a kind of symbiosis did develop which sustained the relationship to the point where one group was unthinkable without the other. All of that changed in the twentieth century in an age characterized by awakening, intolerant ethnic nationalism and total war. Indeed, by the end of the Thirty Years' War of this century, the long Czech-German relationship in Bohemia came to a bitter, and seemingly permanent, end through the expulsion of the Germans of Czechoslovakia.
Czech-Sudeten German Relations in Light of the “Velvet Revolution”: Post-Communist Interpretations∗
Authors: Wingfield Nancy Meriwether
Published: October 2007

On 27 February 1992, almost 47 years after the end of the Second World War, Chancellor Helmut Kohl of a re-united Germany and President Václav Havel of the Czech and Slovak Federal Republic [the ČSFR] signed a Friendship Treaty between their two countries in the Spanish Room of Prague Castle, the residence of the Czechoslovak president. While this treaty could have signalled a new era of Sudeten German-Czech relations, in fact it did not, as some 2,000 protesters who greeted Kohl and Havel with denunciatory placards following the signing made clear. Why not?
The Ethnic Democracy Thesis and the Citizenship Question in Estonia and Latvia
Authors: Smith Graham
Published: October 2007

Although a number of commentaries exist on the citizenship question in Estonia and Latvia, there is as yet no study that develops a conceptual framework which considers the particularity of these citizen-state formations and the implications that follow for ethnic relations. Based on a series of decrees culminating in their respective citizenship laws of 1992 and 1994, both Estonia and Latvia opted to exclude a third of their permanent residents, made up mostly of the Russian-speaking population, from being granted an automatic right to membership of the citizenpolity. This differed from the other post-Soviet states who granted citizenship to all those permanently residing within their bounded territory at the moment the declaration of statehood. This article, therefore, aims to redress this blank spot in conceptual theorizing by considering Estonia and Latvia as polities that come close to resembling ethnic democracies.
The Western Finnic Minorities and the Origins of the Stalinist Nationalities Deportations
Authors: Gelb Michael
Published: October 2007

Wept the boat without her oars,

Pined she for her rowlocks,

For her oarsmen did she grieve,

To take her o'er the waves….

From a Karelian folk song

TheGulag Handbookstates that in 1936 “the entire native populations of Finns, Estonians, Letts, Lithuanians, Poles, and Romanians…were transported” from the border zone of the USSR. Many such peoples began to appear unreliable through Stalinist eyes because they “had relatives across the border,” and “might undermine [propaganda that people] abroad were suffering and that no better life existed than that in the USSR.” Several former officers of the security police confirm that the 1930s saw purges of “unreliable elements” from border regions, including not only “class aliens” and political malcontents, but also minorities whose kinship with populations of neighboring states facilitated the movement of people and of information across borders. More importantly, numerous personal accounts gave rise to the perception in the contemporary Finnish government and popular circles that their brethren were being systematically eliminated from the Soviet borders with Finland and Estonia.
Politics and Society in Upper Silesia Today: The German Minority Since 1945
Authors: Cordell Karl
Published: October 2007

In 1919, Polish nationalist forces led by Josef Pilsudski succeeded in re-establishing an independent Polish state. Poland had disappeared from the map of Europe in 1794 following the third partition. It had been devoured by its traditional enemies; Prussia, Austria and Russia. Historically, Poland had been a state without fixed borders, and via a combination of changing dynastic alliances and a pattern of eastward migration, from the twelfth century formerly Slav areas east of the rivers Oder and Neisse became progressively germanicized. By 1921, following the end of World War I, several peace conferences, and after a series of referenda in disputed (former) German areas and a series of wars with all of its neighbors, including an especially successfully prosecuted war against the embryonic Soviet Union, the new state had managed to become a state which incorporated virtually all ethnic Poles. However, in addition to incorporating the overwhelming majority of ethnic Poles, the borders of the new Polish state also included huge numbers of other ethnic, religious and national groups.
Preface: The Historical Geography of the Hungarian Nation
Authors: Ludanyi Andrew
Published: October 2007

The fate of Hungarian minorities in East Central Europe has been one of the most neglected subjects in the Western scholarly world. For the past fifty years the subject—at least prior to the late 1980s—was taboo in the successor states (except Yugoslavia), while in Hungary itself relatively few scholars dared to publish anything about this issue till the early 1980s. In the West, it was just not faddish, since most East European and Russian Area studies centers at American, French and English universities tended to think of the territorial status quo as “politically correct.” The Hungarian minorities, on the other hand, were a frustrating reminder that indeed the Entente after World War I, and the Allies after World War II, made major mistakes and significantly contributed to the pain and anguish of the peoples living in this region of the “shatter zone.”
Inter-Ethnic Relations in the Hungarian Half of the Austro-Hungarian Empire
Authors: Szász Zoltán
Published: October 2007

The collapse of the three great multi-national and multi-ethnic empires—the Czarist Russian, the Ottoman Turkish and the Austro-Hungarian—was an immediate consequence of World War I and the ensuing revolutions. Of these three, only the empire of the Habsburgs was really considered to be an integral part of nineteenth-century European developments. Although historians and contemporaries may have questioned its modernity and viability, few would have challenged its credentials as part of Europe. Yet its demise was rooted—as for the other empires—in the unresolved nationality questions which still bedevil the region in our own time.
From Austria-Hungary to the United States: National Minorities and Emigration 1880-1914
Authors: Frank Tibor
Published: October 2007

At the beginning of his political career, Count Kuno Klebelsberg, the remarkable future Hungarian Minister of Culture and Education of the 1920s, prepared a statement on emigration from Hungary for Prime Minister Kálmán Széll in 1902. “[W]e must correct a great and general mistake, that might unfortunately lead to disappointment,” Klebelsberg warned the PM. “Unwilling to make a distinction among people from the point of view of nationality, we call everybody residing in Hungary a Hungarian. This is how it became fashionable to speak of 'the emigration of Hungarians' when emigration was discussed, giving the general public, unaccustomed to making distinctions, the mistaken belief that we are talking about the emigration of Hungarians who speak the native tongue. This is why the return of the emigrants and corresponding official arrangements are demanded. The case is different, however. The two largest contingents contributing to the [“Hungarian”] emigration are Slovaks and Ruthenes.”
Hungarians in the Successor States: From World War I to World War II
Authors: Tóth Pál Péter
Published: October 2007

A direct consequence of World War I was the collapse of the Austro-Hungarian Monarchy and the establishment of new states in its place. This has had far-reaching consequences for both regional and world politics. The existing balance of power as well as social, economic and political problems within the Austro-Hungarian Monarchy, including the nationality conflicts, led to this result. In spite of the unavoidable collapse, the successors, the new states, were not the result of a natural evolution, but were the creations of the major powers—France, Great Britain, the United States and Italy—who through the creation of their new post-war order ignored the long-term interests of the region and the actual ethnic composition of the land.