bluuebunny/crossref_metadata_2025 huggingface dataset:
The New Approach of Intercalation Material for The Application of Rechargeable Lithium Batteries
Authors: Wen Shi-Jie , Yin Xiao-Tian , Nazar L.
Published: April 2008

A new approach of lithium electrochemical (de)intercalation material has been put forward. This
approach requires a two‐compound (physically or chemically) composite in which one is a chemically
and electrochemically stable and porous (tunnel, cage, layer, etc.) compound such as clay or zeolite,
and the other is a chemically and electrochemically stable and metallic compound such as graphite,
metal powder or black carbon. Neither does the redox couple in this composite absolutely exist nor
does the redox reaction, which is associated with electrochemical charge and discharge processes when
this composite is used as an cathodic electrode in a lithium battery cell. In this paper, we show the
results of the lithium electrochemical intercalation process in both black carbon‐mixed zeolite and clay
electrodes. In these solid electrodes, black carbon serves to delocalize (transport) electrons for balancing
the charges while zeolite and clay offer the neutrally reversible sites for lithium ions. This approach
can hopefully become a guide for the designing of new intercalation material and so will be very important
in the application of the lithium rechargeable battery.
New Universal Current‐Mode Filter Using Non‐Inverting Second‐Generation Current‐Conveyors
Authors: Abuelma′atti Muhammad Taher , Farooqui Aamir Alam
Published: April 2008

A new universal active current‐mode filter with single input and five outputs is presented. The proposed
filter avoids the use of feedback in any part of the circuit and uses only one type of second‐generation
current‐conveyors, grounded resistors, and grounded capacitors. The proposed circuit can simultaneously
realize lowpass, highpass, bandpass, allpass, and notch biquadratic filter functions.
Programmable Second‐Generation Current‐Conveyor With Variable Current Gain
Authors: Abuelma′atti Muhammad Taher , Al-Ali Abdulrahman Khalaf , Abdulshakoor Abdulrafeeq
Published: April 2008

A new programmable second‐generation current‐conveyor is proposed. The proposed circuit uses a commercially
available second‐generation current‐conveyor and one operational transconductance amplifier.
Simulation results confirming the presented theory are included.
TiO2–Polymer Nano–Composites bySol–Gel
Authors: Pierre A. C. , Campet G. , Han S. D. , Huang S. Y. , Duguet E. , Portier J.
Published: April 2008

Sol‐gel processes make it possible to develop new hybrid electrolyte materials of the type ceramic‐polymer,
known as Nano‐Crystallite‐Insertion‐Material (NCIM). They can be used in reversible alkali
electrochemical cells after insertion with cations such as Li+. In the present study, TiO2‐polyethylene oxide hybrid materials were synthesized from TiCl4 and from Ti ethoxide. Their structure is analyzed in
relation with the processing parameters. A primary evaluation of the nanoscale composite materials for
reversible Li insertion was performed.
A Novel Method for Measurement of Capacitances and Their Loss Factors
Authors: Abuelma′atti Muhammad Taher , Alzaher Hussain Abdullah , Buhalim Sami Saud
Published: April 2008

A novel and simple technique for measurement of capacitances and their losses is presented. The
method is based on a partially active‐R sinusoidal oscillator. Experimental results are in good agreement
with the theoretical analysis.
Magnetic Susceptibility of Tetrahedrally Bonded Amorphous Semiconductors
Authors: Grado Caffaro M. A. , Grado Caffaro M.
Published: April 2008

A special theoretical formulation on the magnetic susceptibility of tetrahedral amorphous semiconductors
is proposed. This formulation is based upon a Wannier representation involving two terms: a diamagnetic
term and a paramagnetic contribution. In addition, electron‐spin resonance referred to amorphous silicon
is considered.
A Detailed Analytical Study OfNon‐Linear Semiconductor Device Modelling
Authors: Kumar Umesh
Published: April 2008

This paper presents a detailed analytical study of Gunn, SCR, and p‐n junction and of the physical
processes that occur inside. Based on the properties of these devices, models for Gunn, SCR, and p‐n
junction diode have been developed. The results of computer simulated examples have been presented
in each case. The non‐linear lumped model for Gunn is a unified model as it describes the diffusion
effects as the‐domain traves from cathode to anode. An additional feature of this model is that it
describes the domain extinction and nucleation phenomena in Gunn dioder with the help of a simple
timing circuit. The non‐linear lumped model for SCR is general and is valid under any mode of operation
in any circuit environment. The memristive circuit model for p‐n junction diodes is capable of simulating
realistically the diode’s dynamic behavior under reverse, forward and sinusiodal operating modes. The
model uses memristor, the charge‐controlled resistor to mimic various second‐order effects due to
conductivity modulation. It is found that both storage time and fall time of the diode can be accurately
predicted.
Digitally Programmable Integrator and Differentiator
Authors: Al-Ali Abdulrahman Khalaf , Abuelma′atti Muhammad Taher , Yunus Syed
Published: April 2008

Digitally programmable integrator and differentiator circuits are presented. Each circuit uses at most one
operational amplifier, two operational transconductance amplifiers, and one capacitor. The time constants
of the circuits are decided by the biasing currents of the operational transconductance amplifiers. The
circuits can be easily interfaced with microprocessor‐based systems. Experimental results are included.
Optically Controlled Microwave Attenuators
Authors: Mital P. Bhushan
Published: April 2008

The concept of photoconductivity is utilized in a number of microwave applications such as switches
and attenuators. Optically controlled microwave attenuators prove an alternative to the conventional
attenuators due to their simplicity, easy of operation, and very narrow ranges of continuously varying
attenuation levels available. This paper describes the design of such configurations of optically controlled
attenuators on a microstrip line fabricated on a semiconductor substrate.
Nanocrystalline TiO2 Electrodes Exhibiting High Storage Capacity and Stability in Rechargeable Lithium Batteries
Authors: Huang Sui-Yang , Kavan Ladislav , Kay Andreas , Grätzel Michael , Exnar Ivan
Published: April 2008

Nanocrystalline TiO2 films were explored for the first time as electrode material for a rechargeable
lithium intercalation cell, i.e., Li/LiCF3SO3 + PC/TiO2. Two kinds of nanocrystalline films, TiO2
F387 (Degussa) and TiO2 colloid‐240, were investigated. These films exhibited excellent performance
renderings them a promising choice for secondary battery applications. At a current density of 0.01
mA/cm2, two voltage plateaus at 1.78 and 1.89 V were observed for TiO2 F387 films during charge and
discharge, respectively. The TiO2 electrode charge capacity per unit weight rose with decreasing
current density. The highest capacity, obtained at a current density of 0.005 mA/cm2 and a final
discharge voltage of 1.4 V, was 265 mAh/g corresponding to a lithium insertion ratio of x = 0.8.
Nanocrystalline TiO2 colloid‐240 films showed a similar performance. The cycle life of a TiO2
colloid‐240 cell at a high current density was found to be excellent; a capacity loss lower than 14% has
been observed over 100 charge/discharge cycles.
A New Method for the Preparation of Fine‐Grained SnO2 and WO3 Powders: Influence of the Crystallite Size on the Electrochemical Insertion of Li+ in SnO2 and WO3 Electrodes
Authors: Han S. D. , Campet G. , Huang S. Y. , Shastry M. C.R. , Portier J. , Lassègues J. C. , Dweik H. S.
Published: April 2008

We propose an unconventional method to obtain fine‐grained SnO2 and WO3 powders. It uses as
precursors, polymer complexes between polyethylene oxide (POE) and SnCl4 or WCl6 respectively. By
pyrolysis of these complexes in the 350‐550? temperature range, metal‐oxide powders possessing small
crystallite sizes are obtained. They are free from water and hydroxyl group contaminations, which is an
added advantage where the application of these materials to Li‐batteries is concerned. We have,
indeed, demonstrated that these powders show good ability to insert reversibly lithium ions in the
Li/ Li+/SnO2 (WO3) cells.
Reversible Electrochemical Insertion of Lithium in Fine Grained Polycrystalline Powders of SnO2
Authors: Han S. D. , Huang S. Y. , Campet G. , Pulcinnelli S. H. , Santilli C. V.
Published: April 2008

Fine grained SnO2 powders have been obtained using an unconventional method. It deals with the well
known polymerization method starting from the metallic halide SnCl4 with polyethylene oxide (PEO).
With this method, SnO2 powders, which are free from water and hydroxyl group contaminations and
possess small crystallite size (), are obtained by appropriate pyrolysis of the polymer. Consequently,
these powders show good ability to insert reversibly lithium ions in the Li/Li+/LixSnO2 cell.
Indeed, by minimizing the size of the crystallites, the formation of defect‐bonds is favored, particularly
at the crystallite surface, acting as reversible (de)grafting sites of Li+. Finally, an easy‐to‐carry out
method to determine the chemical diffusion coefficient of lithium has been proposed.
Mechanisms of the Reversible Electrochemical Insertion of Lithium Occurring with NCIMs(Nano–CrystalliteInsertion–Materials)
Authors: Han S. D. , Treuil N. , Campet G. , Portier J. , Delmas C. , Lassègues J. C. , Pierre A.
Published: April 2008

A new family of insertion‐compound electrodes, so called NCIMs (Nano‐Crystallite‐Insertion‐Materials) has been proposed: the major requirement is that the electrode materials have to be polycrystalline with a crystallite and particle size as small as possible (the accepted definition being that many
crystallites make a particle). Indeed, by minimizing the size of the crystallites, the formation of defects
is favored, particularly at the crystallite surface, acting as reversible (de)grafting sites of Li+. Also, the
cation‐anion bonding is weakened not only in the grain boundary region but also within the crystallite
close to its surface: then the electrochemical insertion of Li+ takes place through easy bonding
rearrangements.
Novel Current‐Conveyor‐Based Single‐Element‐Controlled Oscillator Employing Grounded Resistors and Capacitors
Authors: Abuelma′atti Muhammad Taher , Al-Ghumaiz Abdallah Al-Ali
Published: April 2008

A novel single‐element‐controlled oscillator using two negative first‐generation current‐conveyors, two
grounded capacitors and three grounded resistors is presented. The proposed circuit enjoys independent
oscillation control through a single grounded resistor and independent frequency control through a
single grounded resistor or a single grounded capacitor.
New Current‐Mode Oscillators Usinga Single Unity‐Gain Current‐Follower
Authors: Abuelma′atti Muhammad Taher
Published: April 2008

A general circuit for realizing current‐mode oscillators using a single negative unity‐gain current‐follower
is presented. Using this circuit new oscillators of this class can be discovered systematically.
Simulation results obtained from three new circuits are presented. The feasibility of obtaining a
quadrature oscillator is investigated.
Chaos in a Non‐AutonomousInductorless Active‐RC Circuit
Authors: Abuelma′atti Muhammad Taher , Johar Mazen M.
Published: April 2008

Chaotic performance of a simple inductorless active‐RC non‐autonomous electronic circuit is reported.
The circuit uses two operational amplifiers, an operational transconductance amplifier, a diode, two
resistors, and one capacitor only. No discrete inductors are involved.
Vlsi Interconnection Modelling Usinga Finite Element Approach
Authors: Kumar Umesh
Published: April 2008

In the last decade, an important shift has taken place in the design of hardware with the advent of
smaller and denser integrated circuit packages. Analysis techniques are required to ensure the proper
electrical functioning of this hardware. An efficient method is presented to model the parasitic
capacitance of VLSI (very large scale integration) interconnections. It is valid for conductors in a
stratified medium, which is considered to be a good approximation for the Si − SiO2 system of which
present day ICs are made. The model approximates the charge density on the conductors as a
continuous function on a web of edges. Each base function in the approximation has the form of a
“spider” of edges. Here the method used [1] has very low complexity, as compared to other models used
previously [2], and achieves a high degree of precision within the range of validity of the stratified
medium.
Particle Size Dependence of TiO2 Electrodes in Rechargeable Lithium Battery
Authors: Huang S. Y. , Campet G. , Treuil N. , Porter J. , Chhor K.
Published: April 2008

Particle size effects in five anatase TiO2 pellet electrodes with different particle sizes (4 ∼ 300nm) and surface areas (8 ∼ 380m2/g) were studied by XRD analysis, chronopotentiometry and chronoamperometry in Li/LiN(CF3SO2)2 + EC:DME/TiO2 cells. Nanosized TiO2 electrodes showed by 22% larger storage capacity, 50% lower overvoltage loss at the same current density, and 75% higher charge density for a given time than microsized ones; electric storage capacity enhances more rapidly with decreasing particle size and increasing surface area in a nanoscale region than in a microscale region. The particle size dependence may be explained by surface morphology of electrodes and existence of structural defects or distortion in the surface layer of TiO2 nanosized particles.
Effect of Learning Rate on the Recognition of Images
Authors: Hamed M. , El Desouky A.
Published: April 2008

This paper presents a study for the effect of learning rate on an approach for texture classification and detection based on the neural network principle. This neural network consists of three layers, which are input, output, and hidden layers. The back propagation technique is considered. A computer algorithm is deduced and applied. In this work, the synthetic textures are generated. The results are taken for the modern computer of AT 486 type. The mathematical analysis is summarized in order to illustrate the effect of learning rate parameter on the exact discrimination during processing. This effect is studied through applications. The minimum consumed time for the computational time of classification in industry is correlated to correspond only the use of only 2 units in the hidden layer of a neural network for real images instead of 11 units.
Measurements and Analytical Computer‐Based Study of CMOS Inverters and Schmitt Triggers
Authors: Kumar Umesh
Published: April 2008

Modified CMOS inverters with three and four transistors have been made. Two varieties of CMOS Schmitt Triggers have been considered. CMOS Schmitt Trigger with wide hysteresis has been obtained. Complete detailed theoretical, experimental and computer based results are derived and exhibited.
Behaviour of Parallel Coupled Microstrip Band Pass Filter and Simple Microstripline due to Thin‐Film Al2O3 Overlay
Authors: Rane S. B. , Puri Vijaya
Published: April 2008

The X‐band behaviour of a seven‐section parallel‐coupled microstrip band pass filter and microstripline due to thin‐film Al2O3 overlay of different thickness is reported in this paper. This Al2O3 film can give a homogeneous overlay structure. There is a substantial increase in the bandwidth due to the overlay, the pass band extending towards higher frequency side. In most of the cases, an increase in the pass band transmittance of a microstripline also increases due to a thin‐film Al2O3 overlay, especially for frequencies less than 9.0 GHz. At higher frequencies, random variations are observed. It is felt that thin‐film overlays can be used to modify the microstripline circuit properties, thereby avoiding costly and time consuming elaborate design procedures.
New Minimum‐Component OTA‐Based Sinusoidal Oscillators
Authors: Abuelma′atti Muhammad Taher , Khan Muhammad Haroon
Published: April 2008

Using a general oscillator structure, new oscillator circuits are systematically derived. These oscillator circuits use two operational transconductance amplifiers (OTAs) and one externally connected passive element, exploiting the inherent zeros of the OTAs to advantage. The feasibility of obtaining oscillation using only two OTAs without externally connected passive elements is investigated. Experimental results are included.
New Temperature‐Insensitive Electronically‐Tunable Grounded Capacitor Simulator
Authors: Abuelma′atti Muhammad Taher , Khan Muhammad Haroon
Published: April 2008

A new circuit for simulating a grounded capacitor is presented. The circuit uses one operationalamplifier (OA), three operational‐transconductance amplifiers (OTAs), and one capacitor. The realized capacitor is temperature‐insensitive and electronically tunable. Experimental results are included.
Skylight Light Intensity Data Logging System
Authors: Udina A. , Jain Lc
Published: April 2008

The design of a skylight intensity data logging system is presented. The proposed system is
able to accept 32 inputs in two 16 input blocks with capabilities for further expansion. A
typical application would be to simultaneously monitor real time change in light intensity in
two skylight units, over a chosen periods of minutes, hours or days.
DNA Cladding with Inorganic Sulphide Nanoparticles
Authors: Vekris A. , Royère A. , Campet G. , Sellier E. , Portier J. , Tuffet S. , Bonnet J.
Published: April 2008

The formation of CdS and CoS2 nanoparticles along the DNA strands have been
studied. The systems DNA‐Cdl2 and DNA‐CoCl2 have been investigated in the solid
state in order to form DNA‐MX2 complex salts used as precursors. They react with
S2-ions giving birth to CdS and CoS2 nanoparticles. A model describing the DNA‐nanosulphide
association is proposed.
Novel Current‐Conveyor‐Based Universal Current‐Mode Biquad Filter with Three Inputs and One Output
Authors: Abuelma′atti Muhammad Taher , Al-Zaher Hussain Abdullah
Published: April 2008

A novel universal current‐mode filter with three inputs and one
high imedance output is presented. The proposed circuit uses four
plus‐type second‐generation current‐conveyors, grounded resistors
and grounded capacitors. The proposed circuit enjoys low active
and passive sensitivities and independent control of the
parameters ω0/Q0 using grounded resistors.
New Grounded‐Capacitor Sinusoidal Oscillators Using the Current‐Feedback‐Amplifier Pole
Authors: Abuelma’atti Muhammad Taher , Al-Zaher Husain Abdullah
Published: April 2008

New current‐feedback‐operational amplifier (CFOA)‐pole‐based sinusoidal oscillator
circuits are presented. Each circuit uses two CFOAs, two (or three) grounded capacitors
and/or resistors. Experimental results are included.
Harmonic and Intermodulation Performance of Envelope Detectors
Authors: Abuelma′atti Muhammad Taher
Published: April 2008

Analytical expressions are obtained for predicting the amplitudes of the harmonics and
intermodulation products at the output of an envelope detector excited by a signal
formed of a carrier plus a number of sidebands. These expressions are in terms of the
ordinary Bessel functions with arguments dependent on the modulations indecies.
Comparison between results obtained using the proposed technique and previously
published results is performed to establish the accuracy of the proposed technique.
Some Considerations on TunnelingLosses in Field‐Effect Devices for Low‐Voltage Microcontrollers
Authors: Grado-Caffaro M. A. , Grado-Caffaro M.
Published: April 2008

The loss power density associated with the tunneling current in a typical MOS cell with a
floating gate is evaluated for high electric‐field strengths in the oxide layer. Furthermore,
problems related to oxide thickness are discussed.
Harmonic and Intermodulation Performance of Nonlinear Electronic Circuits
Authors: Abuelma′atti Muhammad Taher
Published: April 2008

A unified technique for mathematical modelling of the input output characteristics of nonlinear
electronic circuits is presented. This technique can be easily implemented using simple
hand computations without recourse to standard curve‐fitting techniques, which invariably
requires extensive computing facilities and well‐developed software. The mathematical
model, basically a sine‐series function, can easily yield closed‐form series expressions for the
amplitudes of the output components resulting from a multisinusoidal input signal to nonlinear
electronic circuits. The technique is very helpful in analysing nonlinear electronic circuits
under different scenarios of input signals.
New Electronically‐Tunable Oscillator Circuit Using Only Two OTAs
Authors: Abuelma′atti Muhammad Taher , Khan Muhammad Haroon
Published: April 2008

New oscillator circuit using two operational transconductance amplifiers and grounded
capacitors is presented. The oscillator circuit enjoys independent control of the
frequency and the condition of oscillation. Experimental results confirming the presented
theory are included.
Analysis of Hot‐Carrier Degradation in Small and Large W/L n‐Channel Transistors
Authors: Bendada E. , Raïs K.
Published: April 2008

Device degradation due to hot‐carrier in n‐channel HEXFETs is shown to be related to
the device geometrical structure. The form of I-V characteristics of the body‐drain
junction is found dependent of the hot‐carrier stressing and of the layer dimensions. A
large increases of the ideality factor, of the reverse recombination current, and of the
series resistance are shown to be more significant for small values of L and W. It is
demonstrated that the degradation of parameters is mainly caused by the generation of
interface traps.
The a‐SiC/c‐Si(n) Isotype Heterojunction as a High Sensitivity Temperature Sensor
Authors: Magafas L. , Georgoulas N. , Thanailakis A.
Published: April 2008

The a‐SiC/c‐Si(n) isotype heterojunction has been studied
as a temperature sensor by measuring its reverse current‐voltage
(IR − V)
and reverse voltage‐temperature (V-T)
characteristics, as well as its reverse current temperature
dependence. The IR − V
characteristics exhibit an almost constant
current, whereas the reverse current IR depends strongly on T
(from 230 K up to 320K). The V-T characteristics, at
different reverse currents, reveal a highly temperature sensitive
behavior for the a‐SiC/c‐Si(n) junction. The measured
values of temperature sensitivity (Δ V/ΔT)max was found to be
(≅−−2.5 V/K) in the moderate temperature range, which are
much higher than those obtained with bulk semiconductor
temperature sensors. The high sensitivity‐temperature‐ range of
the a‐SiC/c‐Si(n) heterojunctions can be controlled
electrically within the regim of values from 230 K up to 320 K.
Finally, the high sensitivity of these devices, in conjunction
with the fact that a‐SiC films can be used as an add‐on to the
existing Si technology, emerge new possibilities to the
fabrication of high sensitivity temperature microsensors.
Programmable Current‐Mode Universal Active Filters Employing Current Conveyors
Authors: Abuelma′atti Muhammad Taher
Published: April 2008

Novel current‐mode active filter circuits using current‐conveyors are presented. The
proposed circuits can realize all standard second‐order filter functions. The circuits enjoy
high output impedances and can, therefore, be easily cascaded to produce higher order
filters. Moreover, the realized filter function can be easily programmed using at most a
13‐bit digital number without changing the circuit topology.
A Discussion on the PhononDensity of States of Amorphous Germanium for the Infrared Range
Authors: Grado-Caffaro M. A. , Grado-Caffaro M.
Published: April 2008

A theoretical formulation for the phonon density of states of amorphous germanium in
the infrared range is proposed. This formulation is based upon the quasi‐harmonic
approximation and is compared with previous results.
Surface Recombination ViaInterface Defects in Field Effect Transistors
Authors: Bendada E. , Raïs K. , Mialhe P. , Charles J. P.
Published: April 2008

Recombination current at the oxide‐semiconductor interface of metal‐oxide‐semiconductor
devices has been analyzed and compared with the experimental result. The
activity of interface traps is dependent on the energy level and on the operating
conditions. A model is shown to be powerful to describe the effect of energy level of bulk
recombination centers on the values of reverse recombination current.
High Speed Non‐Linear Circuit Simulation of Bipolar Junction Transistors
Authors: Doja M. N. , Moinuddin  , Kumar Umesh
Published: April 2008

This paper presents HIBTRA (High Speed Bipolar Transistor Analysis), a high speed non‐linear bipolar transistor circuit simulation package. The paper discusses about the modelling of Bipolar Junction Transistor operated at high speed in the sinusoidal small signal and the transient region of operations. The package uses a high frequency model non‐linear circuit elements for accurate analysis. The package also uses transistor′s lumped circuit model to calculate devices electrical parameters, and it also does dynamic simulation. It also includes the conventional model as a special case. Model verification has also been done by simulation.
Degradation of VDMOSFET by Heavy Ion Irradiations
Authors: Salame C. , Pelanchon F. , Mialhe P.
Published: April 2008

This article focuses on the effect of the heavy ions irradiations on the electrical
characteristics of VDMOSFET (Vertical Diffusion Metal Oxide Semiconductor Field
Effect Transistor) devices. A summary of the total dose effects and the single event effects
is covered to evaluate the experimental observations. Device degradations due to the hot
carriers junction avalanche are studied by a physical parameters extraction method,
leading to an understanding of the degradation processes. Results show that a protective
resistor load can reduce the degradation effect in the device.
Improved grading and survival prediction of human astrocytic brain tumors by artificial neural network analysis of gene expression microarray data
Authors: Petalidis Lawrence P. , Oulas Anastasis , Backlund Magnus , Wayland Matthew T. , Liu Lu , Plant Karen , Happerfield Lisa , Freeman Tom C. , Poirazi Panayiota , Collins V. Peter
Published: April 2008

Histopathologic grading of astrocytic tumors based on current WHO criteria offers a valuable but simplified representation of oncologic reality and is often insufficient to predict clinical outcome. In this study, we report a new astrocytic tumor microarray gene expression data set (n = 65). We have used a simple artificial neural network algorithm to address grading of human astrocytic tumors, derive specific transcriptional signatures from histopathologic subtypes of astrocytic tumors, and asses whether these molecular signatures define survival prognostic subclasses. Fifty-nine classifier genes were identified and found to fall within three distinct functional classes, that is, angiogenesis, cell differentiation, and lower-grade astrocytic tumor discrimination. These gene classes were found to characterize three molecular tumor subtypes denoted ANGIO, INTER, and LOWER. Grading of samples using these subtypes agreed with prior histopathologic grading for both our data set (96.15%) and an independent data set. Six tumors were particularly challenging to diagnose histopathologically. We present an artificial neural network grading for these samples and offer an evidence-based interpretation of grading results using clinical metadata to substantiate findings. The prognostic value of the three identified tumor subtypes was found to outperform histopathologic grading as well as tumor subtypes reported in other studies, indicating a high survival prognostic potential for the 59 gene classifiers. Finally, 11 gene classifiers that differentiate between primary and secondary glioblastomas were also identified. [Mol Cancer Ther 2008;7(5):1013–24]
Chromosome variation in the embryos of domestic animals
Authors: King W.A.
Published: April 2008

Chromosome abnormalities in the embryos of domestic animals are mostly eliminated during development. De novo chromosome abnormalities in the embryos of domestic animals have been detected in a larger proportion of embryos produced by in vitro fertilization and somatic cell nuclear transfer than in those produced by natural mating or artificial insemination. The increased incidence of abnormalities in embryos produced in vitro provides evidence for an influence of the embryo production procedures on chromosome stability. Research strategies involving cytogenetics, molecular biology and reproductive biotechnologies hold the promise of yielding insight into the mechanisms underlying chromosome instability in embryos and the impact of the in vitro environment on the chromosome make-up of embryos.
Meiotic segregation analysis in cows carrying the t(1;29) Robertsonian translocation
Authors: Bonnet-Garnier A. , Lacaze S. , Beckers J.F. , Berland H.M. , Pinton A. , Yerle M. , Ducos A.
Published: April 2008

Heterozygous carriers of Robertsonian translocations generally have a normal phenotype but present reproductive failure. In cattle, the t(1;29) Robertsonian translocation is very common and carriers show a 3–5% decrease in fertility. Some data suggest that female carriers have a higher decrease than male carriers but no direct studies of the chromosome content of oocytes from a t(1;29) carrier cow have been performed so far. Four heterozygous carrier cows underwent hormonal stimulations and follicles punctions and about 800 oocytes were matured in vitro. Six hundred metaphase II preparations were obtained and analysed by fluorescent in situ hybridization with bovine chromosome 1 and 29 painting probes. Proportions of different kinds of oocytes were assessed: 74.11% (292/394) were normal and balanced, 4.06% (16/394) unbalanced and 21.83% (86/394) diploid. For all cows, the number of normal oocytes was not significantly different from the number of translocated oocytes but the diploidy and unbalanced rate were significantly different between them. As found in bulls, the meiotic segregation pattern in cows has shown a preponderance of alternate products. However, the frequency of unbalanced gametes determined in females (4.06%) was significantly higher than the frequency observed in males (2.76%). The divergence in the rate of diploid gametes (0.04% vs. 21.83%) is mainly explained by the difference between males and females.
A new case of rob(14;17) in cattle
Authors: De Lorenzi L. , Molteni L. , De Giovanni A. , Parma P.
Published: April 2008

Robertsonian translocations, also called centric fusions, represent the most frequent chromosome anomalies in cattle, and rob(1;29) is the most widespread. However, centric fusions involving other chromosomes have been discovered in different cattle breeds. Here we report the appearance of a new case of rob(14;17) in an Italian cattle breed more than ten years after the first and only case had been observed, and we demonstrate the independent origin of this anomaly from the previous case.
Complete mitochondrial genomes of Bos taurus and Bos indicus provide new insights into intra-species variation, taxonomy and domestication
Authors: Hiendleder S. , Lewalski H. , Janke A.
Published: April 2008

The taurine and zebuine cattle breeds comprise the majority of the world cattle population but their taxonomic status is still controversial. The two forms of cattle are currently classified as Bos taurus and Bos indicus species and are differentiated primarily by the presence or absence of a hump. However, these two species hybridize readily, producing fully fertile offspring. We have determined and analyzed complete B. taurus and B. indicus mitochondrial genome sequences to investigate the extent of sequence divergences and to study their taxonomic status by molecular dating. The sequences encompassed 16,338 and 16,339 nucleotides, respectively, and differed at 237 positions. Estimated divergence times indicated that the two cattle lineages separated 1.7–2.0 million years ago. Combined phylogenetic analyses of 18 new and 130 previously reported extant B. taurus and B. indicus control region sequences with data from 32 archaeological specimens of the extinct wild aurochs (Bos primigenius) identified four major maternal lineages. B. primigenius haplotypes were present in all but the B. indicus lineage, and one B. taurus sequence clustered with B. primigenius P haplotypes that were not previously linked with domestic cattle. The B. indicus cluster and a recently reported new B. primigenius haplotype that represents a new lineage were approximately equidistant from the B. taurus cluster. These data suggest domestications from several differentiated populations of B. primigenius and a subspecies status for taurine (B. primigenius taurus) and zebuine (B. primigenius indicus) cattle.
Molecular analysis of the fragile histidine triad (FHIT) tumor suppressor gene in vesical tumors of cattle with chronic enzootic hematuria (CEH)
Authors: Guidi E. , Uboldi C. , Ferretti L.
Published: April 2008

The FHIT (fragile histidine triad) gene is a tumor suppressor gene known to be inactivated in many tumors including bladder tumors and is spanning FRA3B, a very active common fragile site in the human genome. We have recently isolated the bovine gene, and the aim of this study was to test whether FHIT presents altered expression patterns in vesical tumors of cattle with CEH (chronic enzootic hematuria). CEH is a common syndrome affecting Mediterranean cattle: clastogenic, mutagenic and cancerogenic substances released by the bracken fern (Pteridium spp) grazed by animals induce the formation of neoplastic lesions, among which bladder tumors have a high incidence. We analysed FHIT in 23 bladder tumors of CEH cattle looking at: 1) the methylation status of the CpG island comprising the promoter and part of exon 1; 2) the presence of altered FHIT transcripts; 3) the mRNA expression levels measured with a quantitative real time PCR (QRT-PCR) approach. Our results suggest that unlike in human tumors, FHIT in vesical tumors of CEH cattle is largely unmethylated. Furthermore, the same mRNA isoforms of FHIT were detected in tumors and in healthy tissues, including a novel isoform that was found in this study. Finally, QRT-PCR data did not reveal significantly altered expression profiles of FHIT transcripts. Further studies and larger sets of cases will be useful to confirm this finding, but the data seem to suggest that epigenetic modifications of FHIT and altered expression profiles are not a hallmark of bovine vesical tumors like they are in human tumors.
Retinoblastoma: From Disease to Discovery
Authors: Madhavan Jagadeesan , Ganesh Anuradha , Kumaramanickavel Govindasamy
Published: April 2008

Retinoblastoma has contributed much to the understanding of cancer. It provided the classic ‘two-hit model’ for oncogenesis and helped to identify the first tumor suppressor gene RB1. Thirty years since then, the search for additional events underlying disease progression continues. Phenotypic variations in retinoblastoma offer numerous clues to disease pathogenesis. Understanding their molecular biological basis will provide insight into mechanisms underlying tumor progression. These not fully understood genetic and stochastic events play a major role in uncontrolled retinal precursor cell proliferation. Comparative genomic hybridization and gene expression studies have facilitated probing of genes controlling basic events in cellular development, i.e. proliferation, differentiation and apoptosis. Research to determine the cell of origin that underlies the evolution of retinoblastoma can lead to understanding of the stochastic events underlying the genesis of this cancer, which currently remains unclear. In this review, we discuss the recent developments in retinoblastoma and describe how they are beginning to shape a new and revised picture of retinoblastoma pathogenesis and progression.
Immunomodulatory Effects of CpG Oligodeoxynucleotides on House Dust Mite-Induced Airway Inflammation in Mice
Authors: Hirose Izumi , Tanaka Hiroyuki , Takahashi Go , Wakahara Keiko , Tamari Mayumi , Sakamoto Tatsuo , Kojima Seiji , Inagaki Naoki , Nagai Hiroichi
Published: April 2008

Background: CpG oligodeoxynucleotides (CpG ODNs) are reported to protect against airway eosinophilia and hyperresponsiveness in animal models of asthma. However, little is known about the effects of CpG ODNs on house dust mites, one of the most common environmental allergens, causing allergic asthma. In the present study, we evaluated the immunomodulatory effects of CpG ODNs on the development of house dust mite-induced airway inflammation and remodeling in mice. Methods: Mice were instilled with Dermatophagoides farinae (Der f) into the trachea 8 times without any additional adjuvants. 48 h after the final allergen instillation, the airway responsiveness to acetylcholine (Ach) was measured, and bronchoalveolar lavage (BAL) and histopathological examination were carried out. CpG ODNs were instilled into the trachea mixed with Der f at the first allergen instillation. Results: Repeated instillation of Der f induced increases in airway responsiveness to Ach, the numbers of inflammatory cells, the levels of T-helper type 2 cytokines and transforming growth factor-β1 in the BAL fluid. Furthermore, goblet cell hyperplasia, the thickness of the epithelium and subepithelial fibrosis were observed. The simultaneous instillation of CpG ODNs with Der f at the first allergen instillation showed significant inhibition of these parameters dose dependently. Conclusions: Our results demonstrate that CpG ODNs have inhibitory effects on Der f-induced airway hyperresponsiveness and eosinophilia, as well as airway remodeling, and that CpG ODNs can be a therapeutic approach for the treatment of house dust mite-induced asthma.
High Serum Tryptophan Concentration in Pollinosis Patients Is Associated with Unresponsiveness to Pollen Extract Therapy
Authors: Kositz C. , Schroecksnadel K. , Grander G. , Schennach H. , Kofler H. , Fuchs D.
Published: April 2008

Background/Aims: The immunologic background of allergic asthma and rhinitis includes a preponderance of Th2-type immunity. In parallel, Th1-type immune response is suppressed by Th2-type cytokines. As a consequence, biochemical pathways triggered by Th1-type cytokine interferon-γ, such as tryptophan degradation by indoleamine 2,3-dioxygenase and neopterin production, might be altered. We examined whether they are related to the outcome of hyposensitization therapy in atopic patients. Methods: In serum specimens of 44 atopic patients (18 women, 26 men) before any specific immunotherapy, tryptophan and kynurenine concentrations were measured by HPLC, and the kynurenine to tryptophan ratio (kyn/trp) was calculated. Neopterin concentrations were measured by ELISA. Results were compared with concentrations in 38 serum specimens from healthy blood donors and with the outcome of specific subcutaneous immunotherapy in atopics: on clinical grounds, 27 patients were classified as responders, and 17 patients as non-responders. Results: Serum tryptophan concentrations were higher in atopics (84.3 ± 24.4 µM) than in blood donors (57.9 ± 7.46 µM; p < 0.001), kynurenine and kyn/trp were not different between the 2 groups. All of the neopterin concentrations measured in patients were <8.7 nM, the upper limit of the normal. Non-responders to subcutaneous immunotherapy had significantly higher tryptophan concentrations (95.7 ± 27.0 µM) than responders (77.1 ± 19.9 µM; p = 0.01). No other marker concentrations differed between the groups. Conclusions: The measurement of serum tryptophan may present an option to predict the outcome of pollen extract therapy. Higher tryptophan levels may result from lower indoleamine 2,3-dioxygenase activity in atopics. However, this possible relationship needs to be confirmed in further studies.
Complete Dermatological Examination in the Elderly: An Exploratory Study from an Outpatient Clinic in Turkey
Authors: Polat Muhterem , Yalçın Başak , Çalışkan Dilek , Allı Nuran
Published: April 2008

Background: The geriatric population isgrowing continuously, therefore more aged patients are being admitted to dermatology clinics. Successful management of these patients requires a thorough understanding of the features of geriatric patients and prevalence of skin diseases in this group. Materials and Methods: Patients aged 65 years and older admitted to the dermatology outpatient clinic over a 3-month period were included. Patients aged between 65 and 74 years were included in group I, and patients older than 74 years were included in group II. Demographic features of the patients were noted. Total dermatological examination was performed in each patient. Fifteen days after the first visit, the patients were phoned up to obtain information about their level of satisfaction regarding the treatments and were invited to the clinic for reexamination where their improvement levels were scored. Results: A total of 209 patients were included in this study. The most common complaints were in the chronic eczema-dermatitis group. However, the most commonly detected disorders were in the chronic sun exposure group. Some severe cutaneous and noncutaneous diseases were detected incidentally at total dermatological examination. Treatment satisfaction scores of patients and improvement scores of doctor had a significantly good correlation. Discussion: The study results indicated that in the management of elderly patients, social and physical evaluation should be carried out and treatment must be recommended accordingly. In all elderly patients, total dermatological examination must be performed because it may reveal some severe cutaneous or underlying noncutaneous diseases.
The At-Risk Foot Concerns Not Only Patients with Diabetes Mellitus
Authors: Pataky Zoltan , Herrmann François R. , Regat Delphine , Vuagnat Hubert
Published: April 2008

Background: The prevalence of the at-risk foot in patients with diabetes is high and is increasing with age. The screening of the at-risk foot should be performed in all geriatric patients and on a regular basis. Objective: To estimate the prevalence of at-risk foot in a geriatric population of patients and to identify associated principal risk factors in patients with diabetes, nondiabetic patients with neurological disorders and subjects without any known cause of sensory loss at the lower limb. Methods: A longitudinal prospective study has been conducted in a university long-term care facility with mostly geriatric patients.Four hundred and twenty-six consecutive hospital admissions were recruited between October 2005 and September 2006.Lower limb neuropathy (LLN) was evaluated by the vibration perception threshold using a 128-Hz Rydel-Seiffer® tuning fork. Peripheral vascular disease (PVD) was evaluated by the Doppler technique. Patients with LLN and/or PVD were considered to have at-risk foot. Results: Of the 426 participants (median age 80 years, range 26–97), 110 (25.8%) had LLN, 82 (19.2%) had PVD and 92 (21.6%) had both LLN and PVD. Diagnosed diabetes mellitus was present in 96 (22.5%) patients and different neurological disorders having impact on foot sensitivity in 100 (23.5%) patients. The prevalence of the at-risk foot was similar in patients with diabetes (68.7%), in nondiabetic patients with chronic neurological medical conditions (66.0%), or in those without any evidence of diabetes or neurological disease (66.1%). Age was shown to be a predictive factor for the presence of LLN (OR 1.02, 95% CI 1.01–1.04, p = 0.002). Conclusion: The prevalence of the at-risk foot in geriatric patients is high, independently of the presence of diabetes. The results suggest that both nondiabetic patients and patients with chronic neurological disorders should be screened for the presence of LLN and PVD as diabetic patients. This screening should be mandatory both in institutions and at home by the general practitioner(s).
Langdon Down Anomaly (Mongolism) with 21/21 Translocation and Klinefelter’s Syndrome in the same Sibship
Authors: Benirschke K. , Brownhill Lydia , Hoefnagel D. , Allen Jr. F.H.
Published: April 2008

Clinical and cytogenetic findings have been described in a family in which the mother had given birth in three successive pregnancies at the ages of 24, 28 and 30 years respectively to a child with the Klinefelter syndrome (44/XXY), a normal male (44/XY) and a daughter with the Langdon Down anomaly, with a translocation within the 21–22 group of chromosomes. No translocated chromosome was found in any other member of the family. All three children had different fathers.
A Case of Chronic Myeloid Leukaemia with a 45-chromosome Cell-line in the Blood
Authors: Atkin N.B. , Taylor Monica C.
Published: April 2008

1. A case of chronic myeloid leukaemia is described in which the majority of dividing cells in a short-term leucocyte culture had 45 chromosomes: a small acrocentric was missing. The Ph1 chromosome appeared to be present in these cells. 2. Other cells had 46 chromosomes and were apparently normal. The chromosomes of these cells were distinguishable from those of the presumed leukaemic cells by virtue of their narrower and more intensely-staining chromatids. 3. The nature of the chromosomal changes in this case are briefly discussed in relation to those described in other cases of chronic myeloid leukaemia.
A Human Intersex (“True Hermaphrodite”) with XX/XXY/XXYYY Sex Chromosomes
Authors: Fraccaro M. , Taylor Angela I. , Bodian M. , Newns G.H.
Published: April 2008

The chromosomes were studied in a human intersex (“true hermaphrodite”) characterized by ambiguous external genitalia and abdominal gonads consisting of a left ovotestis and a right primitive testis. The tissues sampled for chromosome studies (two skin biopsies, right gonad and blood) contained cells having 46, 47 and 49 chromosomes and XX, XXY and XXYYY sex chromosomes respectively. This finding strongly supports the concept that testicular tissue develops only in the presence of the Y chromosome. It is considered plausible that all human íntersexes are chromosomal mosaics. The cytological investigations of the apparent exceptions so far reported in the literature (intersexes with XX sex chromosomes) have been confined to a single tissue specimen.
Enhancement of Secondary Constrictions and the Heterochromatic X in Human Cells
Authors: Saksela E. , Moorhead P.S.
Published: April 2008

Methods are presented which permit identification of the human X, Y, and specific autosomal sites through a differential action upon presumably heterochromatic portions of metaphase chromosomes. Two modifications of the commonly used air-drying technique for spreading chromosomes were studied using human diploid “fibroblastic” strains. Comparative studies were made with mixtures of male and female cells to control sources of variation. A strong enhancement of secondary constrictions in autosomes No. 1, 9, 16, 4–5, and in the Y was obtained with both procedural variants. In female cells a modified fixative was shown to cause one X chromosome to appear negatively heteropycnotic, permitting its identification in a high proportion of metaphases. The appearance of this X and the affected part of the Y was similar to induced secondary constrictions (No. 1, 9, and 16), being diffuse, pale and puff-like. Evidence that the affected metacentric in female cells was indeed an X was provided by a parallel demonstration in the easily recognizable X chromosomes of cultured Syrian hamster cells. The heterochromatic nature of the allocyclic X and the morphologically similar nature of all these described features imply a common response of heterochromatin in general. Techniques presented provide a convenient means for identification of the X chromosome.