bluuebunny/crossref_metadata_2025 huggingface dataset:
Anti-CD3 scFv-B7.1 fusion protein expressed on the surface of HeLa cells provokes potent T-lymphocyte activation and cytotoxicityThis paper is one of a selection of papers in this Special Issue, entitled International Symposium on Recent Advances in Molecular, Clinical, and Social Medicine, and has undergone the Journal's usual peer-review process.
Authors: Yang Zhang-Min , Li En-Min , Lai Bao-Chang , Wang Yi-Li , Si Lu-Sheng
Published: May 2007

The targeting of tumor cells by cytotoxic T lymphocytes is a promising strategy for biotherapy, but T cells require 2 signals via the T-cell receptor – CD3 complex and CD28 molecules for activation. To bridge the gap between cytotoxic T lymphocytes and tumor cells, our objective in this study was to describe the construction and the cell surface-anchored expression of a fusion protein, anti-CD3 scFv-B7.1, derived from inserting a fusion gene encoding anti-CD3 scFv and the extra-cellular domain of B7.1 fused by the splicing by overlap extension method into a mammalian expression vector, pDisplay. Transfection of the recombinant vector by electroporation into HeLa cells resulted in the production of protein migrating at approximately 57 kDa under reducing conditions. The expressed fusion protein could bind to T lymphocytes and induce strong T-cell activation. Meanwhile, a potent cytotoxicity was induced in the mixed culture of T-cell-modified tumor cells in a 96 h methyl-thiazolyl-diphenyl tetrazolium bromide assay. Our results indicate that this bifunctional protein, through activating T lymphocytes to lyse homologous human carcinomas, may be of potential value for T-cell-based immunotherapeutical treatment protocols in vivo.
Reactive oxygen species and mitochondrial membrane potential are modulated during CDDP-induced apoptosis in EC-109 cellsThis paper is one of a selection of papers in this Special Issue, entitled International Symposium on Recent Advances in Molecular, Clinical, and Social Medicine, and has undergone the Journal's usual peer-review process.
Authors: Jing Xu-Bin , Cai Xian-Bin , Hu Hui , Chen Su-Zuan , Chen Bin-Ming , Cai Ju-Yu
Published: May 2007

cis-Diamminedichloroplatinum (CDDP), commonly know as cisplatin, is a well known DNA-damaging agent, which is highly active in suppressing the proliferation of tumor cells. However, it is not clear that CDDP can induce growth inhibition of esophagus cancer cells. Using the cell line EC-109 from the esophagus, we found that CDDP would induce apoptotic responses. The addition of CDDP to cells led to the inhibition of growth in a time- and dose-dependent manner. CDDP generated reactive oxygen species (ROSs) in cells, which brought about a reduction in the intracellular mitochondrial transmembrane potential (Δψm), leading to apoptosis. Our findings demonstrate that ROSs, and the resulting oxidative stress, play a pivotal role in apoptosis. Preincubation of EC-109 cells with the hydrogen-peroxide-scavenging enzyme catalase partially inhibited the following: (i) the production of ROS; (ii) the disruption of the Δψm; and (iii) apoptosis. These results indicate that the enhancement of the generation of ROS and the disruption of Δψm are events involved in the apoptotic pathway of EC-109 induced by CDDP.
MICRO-PIXE CHARACTERIZATION OF AMORPHOUS SILICA GLOBULES FROM A HYDROTHERMAL FIELD ON THE SEA FLOOR OF OKINAWA, SOUTHERN JAPAN
Authors: Murao Satoshi , Sie Soey H.
Published: May 2007

During the examination of the representative specimens, a barite ore and a polymetallic chimney, from the JADE hydrothermal field of Okinawa Trough, many amorphous silica globules of approximately 10 to 50 micrometers in diameter were found as isolated sphere or bunchy aggregation. We performed micro-PIXE analyses of the globules to check the effectiveness of the method to such soft and vulnerable material, and to understand the geochemical characteristics. The result shows that amorphous silica can include various kinds of elements in lithophile, chalcophile and siderophile categories. The trace element distribution of the globules indicates that amorphous silica could be a good monitor of geochemical environment; and implies that the chemical variation of ore often found in a mineral field is mainly derived by change in local physicochemical conditions of single mineralizing fluid rather than multiple injection of the solution.
PIXE ANALYSIS SHOWED THAT THE PREIRRADIATION ENHANCED RECOVERY OF BONE MARROW ELEMENTS AFTER CHALLENGING IRRADIATION IN C57BL/6N MICE
Authors: MATSUDA Y. , YONEZAWA M. , NISHIYAMA F.
Published: May 2007

Priming X-irradiation with 0.3-0.5 Gy induces radio-resistance in C57BL/6 strain of mice 2 weeks afterward. Elements in the bone marrow, sampled 11 days after challenging exposure to 5.0 Gy, were determined by PIXE. The challenging irradiation decreased Mg , P , S , K , Ca and Zn as well as dried bone marrow weight. The pre-irradiation enhanced recovery of these levels, indicating stimulated recovery of the metabolism in the tissue. Fe in both control (without pre-irradiation) and experimental groups increased to about twice the original value, showing elevated hemoglobin synthesis after challenging exposure. In previous studies we have reported that recovery of peripheral blood cell counts after sub-lethal irradiation was enhanced by the pre-irradiation. Further, study on accumulation of p53 and Bax proteins, which lead to apoptotic cell death, revealed that the pre-irradiation significantly suppressed accumulation of these proteins in the spleen after challenging irradiation with 3 Gy. These results and our present study suggest that the pre-irradiation decreased the spleen cell death, and favored re-growth of the spleen cells, resulting in stimulated recovery of metabolism for hematopoiesis in the bone marrow as well as in the spleen after challenging high dose irradiation. Stimulated recovery of Mg , P , S , K , Ca and Zn levels might indicate the importance of these elements in hematopoiesis.
PIXE APPLICATION FOR MEASUREMENT OF BIOACCUMULATION OF LEAD BY MARINE MICRO-ALGAE
Authors: IWATA Y. , SUZUKI M.
Published: May 2007

Marine micro-algae (Nannochloropsis sp., and Phaeodactylum sp.,) were obtained from the Pacific Ocean of Iwate Pref., Japan and purely cultured in nutritive seawater as a culture solution. The culture size for algae was 10 - 250 ml and every apparatus was small and of low cost. Marine micro-algae were given in different culture solutions including Pb 2+ from 0.01 to 1.0 mg /l. The algae in 5 ml of the culture solution were collected on a polycarbonate filter (pore size : 1.0 μm) by suction filtration. The algae on the filter were subjected to PIXE analysis. Concentrations of Na , Mg , Si , P , S , Cl , K , Ca , Cr , Mn , Fe , Cu , Zn , Sr and Pb were simultaneously determined. PIXE can do multi-element analysis for a sample of below 1 mg. The quantity of lead in marine micro-algae increases in proportion to the Pb 2+ concentration in the culture solution. The concentration factor (wet weight base) for lead is given as 200 ± 20 ml / g for Nannochloropsis sp. and 1900 ± 400 ml / g for Phaeodactylum sp.. It is shown that PIXE is a powerful tool for the measurement of the bioaccumulation of trace elements.
FRICTION WEAR AND DISSOLUTION OF ORTHOPEDIC IMPLANT SYSTEMS
Authors: Ektessabi A. M. , Shikine S. , Hamdi M. , Kitamura N. , Rokkum M. , Johansson C.
Published: May 2007

Bio-medical implants release metallic elements during the long periods of time while inserted in the human body. The chemical interactions between the tissues and surface of the implants, and the mechanical friction of implants cause the release of metals into the human tissues. In this study we investigated the distribution and the chemical-state of the metallic elements in the tissues around a failed implant system using PIXE (proton induced x-ray emission) and SR-XRF (synchrotron radiation x-ray fluorescence) spectroscopies. The specimens were from the cases of patients with diagnosed arthritis. The implant consisted of a stem and a metal backing made of Ti -6 Al -4 V , an implant head made of stainless steel, and a polyethylene (PE) cup. Both the stem and the metal backing had a plasma-sprayed HAp surface coating. Distribution and concentration of dissolved elements in tissues surrounding implants were examined and quantified using PIXE analysis. Similar specimen from the same case was further investigated using SR-XRF analysis. Chemical-states of the dissolved elements ware also studied by XAFS (x-ray absorption fine structure) analysis. From results of these measurements, it is confirmed that the tissues surrounding implants contained metallic elements such as Fe , Cr , Ni , and Ti . These elements are originated from the implant. Furthermore, it was made clear that the chemical-state of Fe had changed as a consequence of dissolution of Fe in the organic tissues.
DIRECT SPECIATION OF SULFUR IN MARINE SEDIMENT BY HIGH-RESOLUTION PIXE
Authors: MAEDA KUNIKO , HASEGAWA TOMOTAKE , HAMANAKA HIROMI , HASEGAWA KENICHI , MAEDA MASARU
Published: May 2007

Chemical shifts of Kα1,2 line of sulfur in marine sediments were measured with in-air high-resolution PIXE in order to examine the possibility of direct speciation of sulfur in such environmental substances. Change of chemical states of sulfur along the depth in the sediments was observed. Oxidation of the sediment samples by air was also examined. Problems to be improved for exact speciation are discussed.
POLARIZATION OF Lℓ X-RAYS FROM NIOBIUM TARGET BOMBARDED WITH 0.84 MeV, 1.38 MeV AND 2.92 MeV PROTONS
Authors: FUTATSUGAWA S. , ISHII K. , YAMAMOTO K. , MATSUYAMA S. , YAMAZAKI H. , SERA K. , ORIHARA H.
Published: May 2007

The alignment effect on the L-shell ionization of Nb atom ( Z =41) by 0.84MeV, 1.38MeV and 2.92MeV proton impact was investigated. The polarization of L ℓ X-rays emitted from the aligned niobium target was measured with the crystal spectrometer combined with a position sensitive proportional counter. The experimental values of the degree of alignment A 2 were compared with the prediction of PWBA theory. It results that the experimental value of A 2 in 1.38MeV proton impact was much larger than the theoretical one, and A 2 of 0.84MeV almost coincides with that of 2.92MeV.
MICRO-BEAM SCANNING PIXE IN NIRS AND THE APPLICATION TESTS TO BIOLOGICAL SAMPLES
Authors: Yukawa M. , Imaseki H. , Yukawa O.
Published: May 2007

Micro-beam scanning system for PIXE analysis newly installed in National Institute of Radiological Sciences (NIRS) was introduced in this paper. Fine ring structure of a fish scale was observed using elemental mapping with proton micro-beam scanning. Pollen was analyzed as one example of single cell to demonstrate the elemental distribution. The minimum size of the proton beam is estimated as 0.4×0.65 μ m .
NON-ABELIAN GAUGED CHIRAL BOSON WITH A GENERALIZED FADDEEVIAN REGULARIZATION
Authors: RAHAMAN ANISUR
Published: May 2007

We consider non-Abelian gauged version of chiral boson with a generalized Faddeevian regularization. It is a second-class constrained theory. We quantize the theory and analyze the phase space. It is shown that in spite of the lack of manifest Lorentz invariance in the action, it has a consistent and Poincaré invariant phase space structure.
PARAMETRIZATION OF TACHYON FIELD
Authors: SHAO YING , GUI YUAN-XING , WANG WEI
Published: May 2007

We assume that universe is dominated by non-relativistic matter and tachyon field and reconstruct the potential of tachyon field directly from the effective equation of state (EOS) of dark energy. We apply the method to four known parametrizations of equation of state and discuss the general features of the resulting potentials.
SEARCH FOR GLOBAL METRIC ANISOTROPY IN TYPE 1a SUPERNOVA DATA
Authors: JAIN PANKAJ , MODGIL MONINDER S. , RALSTON JOHN P.
Published: May 2007

We examine the Type 1a supernova data in order to determine if it shows any signal of large scale anisotropy. The anisotropy is modelled by an extended Gödel metric, which incorporates expansion along with rotation. The model is smoothly connected to the usual FRW type, while expressing anisotropic metric effects depending on certain parameters. We find no significant signal of anisotropy in the data. We obtain bounds on an anisotropic redshift versus magnitude relationship, and accompanying parameters of the Gödel–Obukhov metric.
THE SL(2,R) WZWN STRING MODEL AS A DEFORMED OSCILLATOR AND ITS CLASSICAL-QUANTUM STRING REGIMES
Authors: RAMÓN MEDRANO M. , SÁNCHEZ N. G.
Published: May 2007

We study the SL (2,R) WZWN string model describing bosonic string theory in AdS3 spacetime as a deformed oscillator together with its mass spectrum and the string modified SL (2,R) uncertainty relation. The SL (2,R) string oscillator is far more quantum (with higher quantum uncertainty) and more excited than the non-deformed one. This is accompassed by the highly excited string mass spectrum which is drastically changed with respect to the low excited one. The highly excited quantum string regime and the low excited semiclassical regime of the SL (2,R) string model are described and shown to be the quantum-classical dual of each other in the precise sense of the usual classical-quantum duality. This classical-quantum realization is not assumed nor conjectured. The quantum regime (high curvature) displays a modified Heisenberg's uncertainty relation, while the classical (low curvature) regime has the usual quantum mechanics uncertainty principle.
TUNING THE STOCHASTIC BACKGROUND OF GRAVITATIONAL WAVES USING THE WMAP DATA
Authors: CORDA CHRISTIAN
Published: May 2007

The cosmological bound of the stochastic background of gravitational waves is analyzed with the auxilium of the WMAP data, differently from lots of works in literature, where the old COBE data were used. From our analysis, it will result that the WMAP bounds on the energy spectrum and on the characteristic amplitude of the stochastic background of gravitational waves are greater than the COBE ones, but they are also far below frequencies of the earth-based antennas band. At the end of this paper a lower bound for the integration time of a potential detection with advanced LIGO is released and compared with the previous one arising from the old COBE data. Even if the new lower bound is minor than the previous one, it results very long, thus for a possible detection we hope in the LISA interferometer and in a further growth in the sensitivity of advanced projects.
A TOPOLOGICAL INTERPRETATION OF THE COLOR CHARGE
Authors: MINGUZZI E. , TEJERO PRIETO C.
Published: May 2007

We develop a theory on a topologically nontrivial manifold which leads to different vacuum backgrounds at the field level. The different colors of the same quark flavor live in different backgrounds generated by the action of the torsion subgroup of H2(M, 2πℤ) on H2(M, 2πℤ) itself. This topological separation leads to a quark confinement mechanism which does not apply to the baryons as they turn out to live on the same vacuum state. The theory makes some topological assumptions on the spacetime manifold which are compared with the available data on the topology of the Universe.
ON THE CORRESPONDENCE BETWEEN NONCOMMUTATIVE FIELD THEORY AND GRAVITY
Authors: YANG HYUN SEOK
Published: May 2007

In this brief review, we summarize the new development on the correspondence between noncommutative (NC) field theory and gravity, shortly referred to as the NCFT/Gravity correspondence. We elucidate why a gauge theory in NC spacetime should be a theory of gravity. A basic reason for the NCFT/Gravity correspondence is that the Λ-symmetry (or B-field transformations) in NC spacetime can be considered as a par with diffeomorphisms, which results from the Darboux theorem. This fact leads to a striking picture about gravity: Gravity can emerge from a gauge theory in NC spacetime. Gravity is then a collective phenomenon emerging from gauge fields living in fuzzy spacetime.
PHYSICAL SINGULARITY IN THE REGULAR SPACE–TIME AND FUNDAMENTAL LENGTH
Authors: DZHUNUSHALIEV VLADIMIR , MYRZAKULOV RATBAY
Published: May 2007

It is shown that formally regular solutions in 5D Kaluza–Klein gravity have singularities. This phenomenon is connected with the existence of a minimal length in nature. The calculation of the derivative of the G55 metric component leads to the appearance of the Dirac δ-function. In this case, the Ricci scalar becomes singular since there is a square of this derivative.
THE VACUUM STATE IN THE HETEROTIC SUPERSTRING THEORY
Authors: POLLOCK M. D.
Published: May 2007

The gravitational vacuum state of the heterotic superstring theory is derived by substituting the maximally symmetric D-space [Formula: see text], where [Formula: see text] is the cosmological constant, into the classical field equations obtained from the effective ten-Lagrangian including quartic higher-derivative terms, [Formula: see text]. If the theory is reduced to the physical dimensionality D = 4, as required by supersymmetry and phenomenology, the ground state, due to [Formula: see text] and [Formula: see text], is anti-de Sitter space with [Formula: see text], where [Formula: see text] is the inverse gauge coupling and κ2 ≡ 8πG N is the gravitational coupling, G N being the Newton constant. The term [Formula: see text], derived from the Euler-number density [Formula: see text], is a total divergence and the quadratic term [Formula: see text], derived from [Formula: see text], vanishes identically, while the quadratic anomaly [Formula: see text], which alone would give rise to a positive Λ(anom), is ignorable for the reduced [Formula: see text] heterotic string, containing n v = 488 vector fields, because Λ( anom ) ≳ -Λ unless n v ≳ 7,000. For hypothetical reduction to the higher dimensonalities D = 5, 9, 10, [Formula: see text] has the effect of augmenting the Boulware–Deser, anti-de Sitter space vacuum due to [Formula: see text], which becomes exact when D = 8, for which [Formula: see text] vanishes identically, but leads to a de Sitter space for D = 6, 7 thus justifying the Ricci-flat vacuum state for the six-dimensional internal space. For simplicity, we assume compactification onto a toroidal internal space when D ≥ 5, so that all contributions of the form [Formula: see text] vanish. The remaining terms [Formula: see text] and [Formula: see text] are then almost comparable in effect, bringing into question the convergence of the Lagrangian power series [Formula: see text] in the Einstein space, and consequently the validity of the results obtained. Without knowledge of the yet higher-order terms [Formula: see text], n ≥ 6, however, no further analysis is possible. As they stand the results constitute a realization of the limiting-curvature hypothesis of Frolov et al., and are also discussed from the viewpoint of causality. Finally, the dimensional parameter a, introduced by Volkov and Akulov to define the non-linear global supersymmetry transformations, gives rise to a negative cosmological constant -κ2/a, which can therefore be identified with Λ (which has the functional dependence [Formula: see text] found by Freedman and Das for extended supergravity). This leads to the estimate B r ~ 2 for the dimensionless radius-squared of the internal space, implying a small radius of compactification, in agreement with previous estimates obtained via supersymmetry, and provides a realization of the super-Higgs effect.
POSSIBLE EVOLUTION OF DIM RADIO-QUIET NEUTRON STAR 1E 1207.4-5209 BASED ON A B-DECAY MODEL
Authors: ANKAY AŞKIN , ANKAY ARZU MERT , ERCAN ENISE NIHAL
Published: May 2007

Dim radio-quiet neutron star (DRQNS) 1E 1207.4-5209 is one of the most heavily examined isolated neutron stars. Wide absorption lines were observed in its spectrum obtained by both XMM-Newton and Chandra X-ray satellites. These absorption lines can be interpreted as a principal frequency centered at 0.7 keV and its harmonics at 1.4, 2.1 and possibly 2.8 keV. The principal line can be formed by resonant proton cyclotron scattering leading to a magnetic field which is two orders of magnitude larger than the perpendicular component of the surface dipole magnetic field (B) found from the rotation period (P) and the time rate of change in the rotation period [Formula: see text] of 1E 1207.4-5209. Besides, age of the supernova remnant (SNR) G296.5 + 10.0 which is physically connected to 1E 1207.4-5209 is two orders of magnitude smaller than the characteristic age [Formula: see text] of the neutron star. These huge differences between the magnetic field values and the ages can be explained based on a B-decay model. If the decay is assumed to be exponential, the characteristic decay time turns out to be several thousand years which is three orders of magnitude smaller than the characteristic decay time of radio pulsars represented in an earlier work. The lack of detection of radio emission from DRQNSs and the lack of point sources and pulsar wind nebulae in most of the observed SNRs can also be partly explained by such a very rapid exponential decay. The large difference between the characteristic decay times of DRQNSs and radio pulsars must be related to the differences in the magnetic fields, equation of states and masses of these isolated neutron stars.
THICK PLANAR DOMAIN WALL: ITS THIN WALL LIMIT AND DYNAMICS
Authors: GHASSEMI S. , KHAKSHOURNIA S. , MANSOURI R.
Published: May 2007

We consider a planar gravitating thick domain wall of the λϕ4 theory as a space–time with finite thickness glued to two vacuum space–times on each side of it. Darmois junction conditions written on the boundaries of the thick wall with the embedding space–times reproduce the Israel junction condition across the wall in the limit of infinitesimal thickness. The thick planar domain wall located at a fixed position is then transformed to a new coordinate system in which its dynamics can be formulated. It is shown that the wall's core expands as if it were a thin wall. The thickness in the new coordinates is not constant anymore and its time dependence is given.
SCALAR POTENTIALS OUT OF CANONICAL QUANTUM COSMOLOGY
Authors: GUZMÁN WALBERTO , SABIDO MIGUEL , SOCORRO JOSÉ , UREÑA-LÓPEZ L. ARTURO
Published: May 2007

Using canonical quantization of a flat FRW cosmological model containing a real scalar field ϕ endowed with a scalar potential V(ϕ), we are able to obtain exact and semi-classical solutions of the so-called Wheeler–DeWitt equation for a particular family of scalar potentials. Some features of the solutions and their classical limits are discussed.
SECOND ORDER FORMALISM IN POINCARÉ GAUGE THEORY
Authors: LECLERC M.
Published: May 2007

Changing the set of independent variables of Poincaré gauge theory and considering, in a manner similar to the second-order formalism of general relativity, the Riemannian part of the Lorentz connection as a function of the tetrad field, we construct theories that do not contain second or higher order derivatives in the field variables, possess a full general relativity limit in the absence of spinning matter fields, and allow for propagating torsion fields in the general case, the spin density playing the role of the source current in a Yang–Mills type equation for the torsion. The equivalence of the second-order and conventional first-order formalism is established and the corresponding Noether identities are discussed. Finally, a concrete Lagrangian is constructed and by means of a Yasskin-type ansatz, the field equations are reduced to a conventional Einstein–Proca system. Neglecting higher order terms in the spin-tensor, approximate solutions describing the exterior of a spin-polarized neutron star are presented and the possibility of the experimental detection of the torsion fields is briefly discussed.
THE GEOMETRY OF THE TORUS UNIVERSE
Authors: MURDZEK R.
Published: May 2007

In this contribution, we show that the cyclic universe models naturally emerge from torus geometry in a braneworld scenario. The Riemannian metric on torus and the fundamental tensors of the General Relativity are derived. A discussion on particular aspects of this model is also given.
ACCELERATED EXPANSION IN MODIFIED GRAVITY WITH A YUKAWA-LIKE TERM
Authors: ATAZADEH K. , SEPANGI H. R.
Published: May 2007

We discuss the Palatini formulation of modified gravity including a Yukawa-like term. It is shown that in this formulation, the Yukawa term offers an explanation for the current exponential accelerated expansion of the universe and reduces to the standard Friedmann cosmology in the appropriate limit. We then discuss the scalar-tensor formulation of the model as a metric theory and show that the Yukawa term predicts a power-law acceleration at late-times. The Newtonian limit of the theory is also discussed in context of the Palatini formalism.
ON THE SPECTRAL SHIFT AND THE TIME DELAY OF LIGHT IN A RINDLER ACCELERATED FRAME
Authors: FORMIGA J. B. , ROMERO C.
Published: May 2007

We discuss two effects predicted by the general theory of relativity in the context of Rindler accelerated observers: the gravitational spectral shift and the time delay of light. We show that these effects also appear in a Rindler frame in the absence of gravitational field, in accordance with the Einstein's equivalence principle.
A VACUUM-LIKE CONFIGURATION IN GENERAL RELATIVITY AS A MANIFESTATION OF A LORENTZ-INVARIANT MODE OF FIVE-DIMENSIONAL GRAVITY
Authors: GLADUSH VALENTIN D.
Published: May 2007

A Lorentz-invariant cosmological model is constructed within the framework of five-dimensional gravity. The five-dimensional theorem which is analogical to the generalized Birkhoff theorem is proved, that corresponds to the Kaluza's "cylinder condition." The five-dimensional vacuum Einstein equations have an integral of motion corresponding to this symmetry, the integral of motion is similar to the mass function in general relativity (GR). Space closure with respect to the extra dimensionality follows from the requirement of the absence of a conical singularity. Thus, the Kaluza–Klein (KK) model is realized dynamically as a Lorentz-invariant mode of five-dimensional general relativity. After the dimensional reduction and conformal mapping the model is reduced to the GR configuration. It contains a scalar field with a vanishing conformally invariant energy–momentum tensor on the flat space–time background. This zero mode can be interpreted as a vacuum configuration in GR. As a result the vacuum-like configuration in GR can be considered as a manifestation of the Lorentz-invariant empty five-dimensional space.
AN LRS BIANCHI TYPE-I COSMOLOGICAL MODEL WITH TIME-DEPENDENT Λ TERM
Authors: SINGH J. P. , TIWARI R. K.
Published: May 2007

In this paper, we investigate locally rotationally symmetric (LRS) Bianchi type-I cosmological model containing stiff matter with a cosmological term proportional to the Hubble parameter. This variation law for vacuum density has recently been proposed by Schützhold on the basis of quantum field estimations in the curved and expanding background. The model obtained approaches isotropy. The cosmological term tends asymptotically to a genuine cosmological constant and the model tends to a de Sitter universe. We obtain that the present universe is accelerating with a large fraction of cosmological density in the form of cosmological term. Taking matter density equal to half of the vacuum density, as suggested by observation, we obtain a universe age given by Ht = 0.55 and a decelerating parameter equal to 2σ2/3H2.
GENERAL DESCRIPTION OF DIRAC SPIN–ROTATION EFFECT WITH RELATIVISTIC FACTOR
Authors: ZHANG C. M.
Published: May 2007

The Mashhoon rotation–spin coupling is studied by means of the parallelism description of general relativity. The relativistic rotational tetrad is exploited which results in the Minkowski metric, and the torsion axial-vector and Dirac spin coupling will give the Mashhoon rotation–spin term. For the high speed rotating cases, the tangent velocity constructed by the angular velocity Ω multiplying the distance r may exceed over the speed of light c, i.e. Ωr ≥ c, which will make the relativistic factor γ infinity or imaginary. In order to avoid this "meaningless" difficulty occurring in γ factor, we choose to make the rotation non-uniform and position-dependent in a particular way, and then we find that the new rotation–spin coupling energy expression is consistent with the previous results in the low speed limit.
A Rapid, High-yielding, and Efficient Friedlander Synthesis of Quinolines Catalyzed by 2,4,6-Trichloro-1,3,5-triazine
Authors: Das Biswanath , Damodar Kongara , Chowdhury Nikhil , Suneel Kanaparthy
Published: May 2007

A general procedure for the synthesis of quinolines via the Friedlander annulation using 2,4,6-trichloro-1,3,5-triazine (TCT) (4 mol %) as a novel catalyst is described. The method is simple, efficient, and rapid to afford quinolines in high yields.
Detection of Antibacterial Activity of Berberine Hydrochloride by Multiwalled Carbon Nanotubes
Authors: Xiao Sai Jin , Li Yuan Fang , Huang Cheng Zhi
Published: May 2007

In order to investigate the effect of multiwalled carbon nanotubes (MWCNTs) as a carrier of drug on its cargoes, this paper choose berberine hydrochloride (BH) as a model and find that MWCNTs have the ability to enhance the antibacterial activity of BH.
An Efficient and Facile Hydroiodination of Alkenes and Alkynes Using Polymethylhydrosiloxane–Iodine System
Authors: Das Biswanath , Srinivas Yallamalla , Holla Harish , Narender Ravirala
Published: May 2007

A mild and efficient method has been developed for the synthesis of alkyl and alkenyl iodides from alkenes and alkynes using polymethylhydrosiloxane (PMHS) and iodine in chloroform at room temperature. The reagent system generates hydrogen iodide which regioselectively adds to the alkenes and alkynes.
Highly Efficient Electron-transporting Phenanthroline Derivatives for Electroluminescent Devices
Authors: Xiao Lixin , Lan Hsinglin , Kido Junji
Published: May 2007

A series of phenanthroline derivatives containing quinoxaline moieties were synthesized, and their electron-transporting properties were investigated by using N,N′-di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (α-NPD) and tris(8-hydroxyquinolato)aluminum (Alq3) as the hole-transporting material and the emitting layer, respectively. Higher external quantum efficiency for the phenanthroline derivative than Alq3 in the electroluminescent devices at a luminance of 100 cd/m2 was obtained.
Conductive Polymer-based Mesoscopic Counterelectrodes for Plastic Dye-sensitized Solar Cells
Authors: Muto Takuma , Ikegami Masashi , Kobayashi Koichi , Miyasaka Tsutomu
Published: May 2007

Semitransparent mesoporous counterelectrode was prepared on a plastic substrate by low-temperature coating of a viscous composite comprising nanocrystalline TiO2 particles and PEDOT–PSS. The electrode shows high cathodic activity in a full-plastic dye-sensitized solar cell, yielding energy conversion efficiency of 4.38%.
A Spin-coated Si/TiOx/Pt/TaOx Electrode for Electrochemical Ozone Generation
Authors: Kitsuka Kenta , Kaneda Kazuhiro , Ikematsu Mineo , Iseki Masahiro , Mushiake Katsuhiko , Mohammad Ahmad M , Ohsaka Takeo
Published: May 2007

A novel electrode, with the composition Si/TiOx/Pt/TaOx (TiOx: titanium oxide, TaOx: tantalum oxide), was fabricated by spin-coating, and its effectiveness at electrochemical ozone generation was compared with that of a traditional Pt plate electrode. The electrode achieved a high current efficiency (1.3%) at a low current density (30 mA·cm−2). The results confirm that TaOx is effective for the ozone generation in electrochemical ozone generation.
Graft Polymerization Initiated by Photosensitizer Segregated at Surface of Polymer Film upon Ultraviolet Irradiation
Authors: Atarashi Hironori , Akabori Kei-ichi , Tanaka Akihiro , Ozawa Masaaki , Tanaka Keiji , Nagamura Toshihiko
Published: May 2007

A novel approach to surface modification of polymer films is proposed on the basis of graft polymerization initiated from photosensitizers attached to hyperbranched polymers which are localized at the film surface.
Control of Rocking Mobility of Rotaxanes by Size Change of Stimulus-responsive Ring Components
Authors: Hirose Keiji , Ishibashi Kazuaki , Shiba Yoshinobu , Doi Yasuko , Tobe Yoshito
Published: May 2007

A rotaxane having a ring molecule composed of a metaphenylene unit which swings as a pendulum and a dianthrylethane unit which undergoes isomerization in response to external stimuli was synthesized. The rates of the rocking motion were switched reversibly and changed substantially in response to photo and thermal stimuli by changing the size of the ring component.
Formation of a Chiral 2D-layered Host System Composed of (1R,2R)-1,2-Diphenylethylenediamine and Benzenediacetic Acid Derivatives
Authors: Imai Yoshitane , Kawaguchi Kakuhiro , Murata Katuzo , Sato Tomohiro , Kuroda Reiko , Matsubara Yoshio
Published: May 2007

A chiral supramolecular host system was developed by combining (1R,2R)-1,2-diphenylethylenediamine and benzenediacetic acid derivatives. These supramolecular complexes are constructed by the self-assembly of a chiral 2D-layered network structure with multiple chiral points derived from chiral transfers.
Mouse strain difference in bile duct lesions induced by swine serum injections
Authors: Imaoka K. , Doi K. , Doi C. , Torlumi W. , Honjo K. , Mitsuoka T.
Published: May 2007

The mouse strain difference in bile duct lesions was studied on male A/J, BALB/c, C57BL/6, C3H/He, DBA/2 and DDY mice 4 weeks old given intraperitoneal injections of swine serum (0·05 or 0·2 ml per mouse) twice a week for 4 weeks. The hepatic lesions were restricted to the portal tract. Biliary epithelial cells showed hypertrophy and hyperplasia, and eosinophilic and homogeneous or needle-shaped material appeared in the cytoplasm of such hypertrophied epithelial cells and in the ductular lumen. Around these damaged biliary epithelia, eosinophil leukocyte and plasma cell infiltration with proliferation of collagen fibres was commonly detected. These changes became more apparent with increasing size of bile duct. Such histopathological characteristics of hepatic lesions were essentially the same in all strains, but the severity showed a clear strain difference: the lesion was marked in the DDY, A/J and BALB/c strains, moderate in C3H/He and slight in C57BL/6 and DBA/2. A high production of anti-swine-serum antibodies associated with a marked increase in the number of mouse IgG-producing lymphocytes in the spleen was detected in the strains showing the marked hepatic lesions.
Histopathology of streptozotocin-induced diabetic DBA/2N and CD-1 mice
Authors: Honjo K. , Doi K. , Doi C. , Mitsuoka T.
Published: May 2007

Histopathological examinations were carried out on female DBA/2N and CD-1 mice which were autopsied 4 and 12 weeks after six daily intraperitoneal injections of streptozotocin (SZ). Histopathological changes related to SZ treatment were found in the pancreas, liver and kidneys. Little difference was observed between the two strains in the histological changes of the pancreas (a decrease in size of the islets, and degranulation and a decrease in the number of B cells) and liver (hypertrophy of hepatocytes and cytoplasmic invagination into hepatocyte nuclei). With regard to the changes in the kidneys, DBA/2N mice showed characteristic inclusions positive to periodic acid-Schiff reagent in the distal tubule epithelial cells, while CD-1 mice showed remarkable luminal dilatation and epithelial cell deformation of distal tubules. SZ-induced diabetes had no innuence on the development of spontaneous cardiovascular lesions in DBA/2N mice under the present experimental conditions.
The rabbit as an experimental model for regional chemotherapy 1. Intra-arterial hindlimb infusion
Authors: Davidson T. , Wallace J. , Carnochan P.
Published: May 2007

Regional delivery of chemotherapy to a tumour or tumour-bearing region has pharmacokinetic advantages over the systemic route. The applications of an animal model for regional drug delivery are outlined. The technique for intra-arterial infusion in the rabbit hindlimb is described. The use of the implantable VX2 rabbit carcinoma as a model for solid human tumours may be studied by this method. Pharmacokinetic data obtained with the model allow comparison between systemic and regional routes of delivery. The distribution of the cancerostatic plant toxin ricin following regional delivery has been investigated using this experimental model.
'Normalization' of germfree mice after direct and indirect contact with mice having a 'normal' intestinal microflora
Authors: Koopman J. P. , Kennis H. M. , Lankhorst A. , Welling G. W. , Hectors M. P. C. , Nagengast F.
Published: May 2007

Germfree mice were associated via direct and indirect contact with a 'normal' microflora by placing 'normal' mice in an isolator with germfree mice. Relative caecal weights, the ratio of secondary to primary bile acids, the presence of filamentous segmented bacteria in the small intestine and faecal β-aspartylglycine were normal 5 days after direct contact and 15 days after indirect contact. Enterobacteriaceae were demonstrated by the third day after direct contact and the fourth day after indirect contact. Volatile and non-volatile fatty acids in the caecal contents were variable and appeared to be unrelated to the 'normalization' process of germfree mice after association with a microflora.
Improving the productivity of breeding colonies of Mongolian gerbils (Meriones unguiculatus)
Authors: Clark M. M. , Spencer C. A. , Galef B. G.
Published: May 2007

The productivity of breeding colonies of Mongolian gerbils can be substantially enhanced by using as breeding stock only the 40% of females that exhibit vaginal opening before reaching 25 days of age. Early-maturing females are more likely to breed successfully on first pairing. The lifetime fecundity of early-maturing females is more than twice that of their late-maturing sisters. In those cases in which early-maturing females fail to breed with the first male with which they are paired, they (but not late-maturing females) can be mated with a second male with a high probability of success. Two-thirds of the early-maturing females that failed to reproduce following a first pairing became pregnant following a second. Only 11% of late-maturing females did so.
Naturally occurring melioidosis in a colonized rhesus monkey (Macaca mulatta)
Authors: Fritz P. E. , Miller J. G. , Slayter M. , Smith T. J.
Published: May 2007

An aged wild-caught male rhesus monkey ( Macaca mulatta), maintained in a research facility for 10 years, developed bilateral pelvic limb paralysis without other signs of disease. Unresponsive to therapy, the monkey was killed and necropsied. Chronic inflammation with osteolysis of thoracic vertebrae 10-13 was observed. Pseudomonas pseudomallei was cultured and identified from cerebrospinal fluid obtained at the site of the thoracic lesion. This Gram-negative bacterium can cause infection in animals and man and may remain latent for years before the appearance of clinical signs.
Spontaneous endometrial tumours of 'Sabra' rats
Authors: Mor N. , Lutsky I.
Published: May 2007

In a 2 year study of 171 female (101 virgin; 70 multiparous) 'Sabra' rats, spontaneous endometrial tumours were found in 69% of 2 year old animals. Tumour development appeared to be age related, and only virgin females showed tumours before 18 months of age. Polyps were the most prevalent tumour type, followed by adenocarcinomas. The Sabra rat can be included among those rat strains having a high incidence of spontaneous endometrial neoplasia.
A possible inhibitory effect on the Shwartzman reaction in the rabbit caused by fentanyl-fluanisone tranquillization
Authors: Næss V. , Fosse R. T. , Hofstad T.
Published: May 2007

Shwartzman's reaction was elicited in four Chinchilla rabbits. Two of the animals were tranquillized with fentanyl-fluanisone (Hypnorm®: Janssen Pharmaceuticals). There was a reduced response in the tranquillized rabbits while the untranquillized animals developed the typical dose-responsive skin reaction. Fentanyl-fluanisone tranquillization may interfere with the development of the Shwartzman reaction in Chinchilla rabbits.
Genetic monitoring of inbred strains of mice using monoclonal antibodies to major histocompatibility haplotypes and lymphocyte alloantigens
Authors: Fernandez J. L. , Weeks M.
Published: May 2007

An enzyme immunoassay procedure is described for the identification of major histocompatibility haplotypes and lymphocyte alloantigens in 19 inbred mouse strains. The assay was found to be useful for the genetic monitoring of such mice.
Periapical abscesses of cut canine teeth in cynomolgus macaques
Authors: Curtis J. W. , Brodish D. L. , Weaver D. S. , Brady A. G.
Published: May 2007

Periapical abscesses of canine teeth in a group of 47 male cynomolgus macaques are found to be associated with a procedure, involving cutting the canine teeth, used to make non-human primates less hazardous. Examination of 150 canine teeth in dry specimens revealed 30 cut teeth with no exposure of the pulpal chamber and 107 cut teeth where the dental pulp had been exposed. Of those teeth which had the pulpal chamber exposed by the cutting procedure, 85 (79·4%) showed clear evidence of osseous changes consistent with abscess formation in the apical regions.
Variation in barbiturate sleeping time in mice 3. Strain × environment interactions
Authors: Lovell D. P.
Published: May 2007

Environmental factors such as diet, bedding material and temperature at the time of testing affected a 'model' pharmacological response - pentobarbitone sleeping time - differentially in a range of inbred strains. These results are probably explained by variations in the responses of the strains to constituents of the diets and bedding materials used in the experiments. Differences in the results between experiments suggest that there are also fluctuations in the composition of the diets and bedding materials over time. Strain × environment interactions such as those found here may explain differences in strain rankings between experiments. They would also account for some of the variability in results found between laboratories and within a laboratory over time.
A backpack system for long-term osmotic minipump infusions into unrestrained marmoset monkeys
Authors: de Elvira M.-C. Ruiz , Abbott D. H.
Published: May 2007

A backpack system is described whereby osmotic minipumps are used to infuse gonadotrophin-releasing hormone (GnRH) subcutaneously in a pulsatile manner into infertile socially subordinate female marmoset monkeys ( Callithrix jacchus jacchus). This procedure enables long-term infusion of GnRH without the necessity of repeated subcutaneous implantation of pumps and GnRH reservoirs. The backpack and cannulae system is inexpensive and can be constructed from commonly available materials. The GnRH treatment successfully overcame the suppression of pituitary luteinizing hormone secretion imposed by the low social status of female marmoset monkeys.
Contribution of pathology to laboratory animal welfare
Authors: Walvoort H. C.
Published: May 2007

To promote experimental animal welfare, several countries are engaged in establishing local animal research review committees and appointing supervising veterinarians or other experts. However, a number of adverse conditions leading to intercurrent illness or death remains unnoticed or unidentified. Pathological investigation of unexpectedly ill or dead animals proved to be very useful in indicating conditions compromising animal welfare. In addition, such post-mortem findings may be instructive, with respect to welfare, for those involved in experiments with animals.
The rabbit as an experimental model for regional chemotherapy 2. Isolated perfusion of hindlimbs
Authors: Davidson T. , Wallace J.
Published: May 2007

Regional chemotherapy to a tumour is most commonly delivered by intra-arterial infusion. An alternative method of regional drug delivery, isolated perfusion, may be used where anatomical considerations permit. The technique of isolated perfusion in the rabbit hindlimb is described. The use of this model with the implantable rabbit VX2 carcinoma allows estimation of drug uptake by normal tissues, primary tumour and popliteal lymph node metastases. Correlation of such data with blood now measurements enables targeting of new cytotoxic agents to be evaluated. The effect of perfusate composition on tissue uptake of such an agent, the plant toxin ricin, has been determined.
A non-invasive technique for sequential collection of earthworm (Lumbricus terrestris) leukocytes during subchronic immunotoxicity studies
Authors: Eyambe George S. , Goven Arthur J. , Fitzpatrick L. C. , Venables Barney J. , Cooper Edwin L.
Published: May 2007

We have compared two methods for collecting earthworm leukocytes (coelomocytes) with respect to cell yield, viability and behaviour in immunoassays. Non-invasive extrusion was more efficient than puncturing the coelomic cavity. Extrusion does not produce trauma to earthworms maintained under long term laboratory conditions. Neither technique modified immune assays, as determined by erythrocyte and secretory rosette formation, and phagocytosis, since all 3 were functionally equivalent. After an initial extrusion, sequential leukocyte collections by extrusion are possible at intervals of 6 weeks without affecting total and differential cell counts and rosette formation.
Sympathetic auricular chondritis in rats: a model of autoimmune disease?
Authors: Meingassner J. G.
Published: May 2007

Following the unilateral implantation of metal ear tags in female Crl:CD(SD)BR-rats, chronic inflammatory lesions were observed in both auricles in 7% and 24% of the animals after 30 and 60 weeks, respectively. Involvement of the collateral auricles was identified only after diffuse inflammation of the ear tag-marked pinnae had developed. Histological examination revealed a multifocal granulomatous chondritis, characterized by progressive destruction of the cartilaginous plate and excessive regeneration of cartilaginous tissue. IgG and complement deposits were present in the matrix of the marginal area of regenerating cartilage and at the destruction sites of autochthonous cartilage. It is likely that the pinally-restricted chondritis was due to an autoimmune response initiated by a chronic inflammatory process at the insertion site of the ear tag. Since the respone was not due to immunity to type II collagen, this pathologic phenomenon in rats may provide a useful animal model to study autoimmunity involving other cartilaginous matrix molecules.
Systemic histopathology of rats with CCl4-induced hepatic cirrhosis
Authors: Doi K. , Kurabe S. , Shimazu N. , Inagaki M.
Published: May 2007

Systemic histopathological examinations were carried out on rats with CCl4-induced hepatic cirrhosis. Moderate congestion in the spleen, prominent oedema and focal acinar cell degeneration in the pancreas, marked haemorrhage and phagocytosis of haemosiderin by macrophages in the pancreaticoduodenal lymph node, appearance of monocytes bearing haemosiderinlike granules in the pulmonary arteries and cardiac right atrium, and focal segmental glomerulosclerosis were consistently observed in rats with hepatic cirrhosis. In addition, a marked increase in number of target cells and the appearance of a small number of monocytes bearing haemosiderinlike granules were also commonly found in the peripheral blood smears of these animals. These findings are considered to be important in the use of the CCl4-induced model of hepatic cirrhosis in the rat.
A simple non-surgical method of intrabronchial instillation for the establishment of respiratory infections in the rat
Authors: Smith Gill
Published: May 2007

A technique involving intubation of weanling rats for intrabronchial instillation of infectious material has been developed to produce a respiratory infection model suitable for experimental infection studies. The technique is performed simply with the use of a metal cannula and an intravenous plastic cannula, and dispenses with the need for illumination, laryngoscopy and extensive manipulation of the animal.