bluuebunny/crossref_metadata_2025 huggingface dataset:
Gibt es eine Lernkurve der Forschung?
Authors: Röß D.
Published: August 2006

Laser is an example of how new markets are created by breakthroughs in basic research. The time development of important research contributions and of product ideas is described, as well as the personal background of A. L. Schawlow, one of the pioneers in both areas. A

Fritz Schäfer ist einer der Pioniere des Lasergebiets. Er hat mit seinen frühen Entdeckungen zu Laserfunktion in organischen Farbstoffen neue Türen geöffnet, und über viele Jahrzehnte hinweg originelle Beiträge zur Anwendung des Lasers als Instrument der Forschung geleistet. Darüber hinaus wurde er durch sein ausgeprägtes Interesse für die praktische Umsetzung wissenschaftlicher Erkenntnisse in industrielle Tätigkeit zum Geburtshelfer bei der Gründung der Firma
A 100 mJ Table-Top Short Pulse Amplifier for 248 nm Using Interferometric Multiplexing
Authors: Bekesi J. , Marowsky G. , Szatmari S. , Simon P.
Published: August 2006

A polarization multiplexing method (based on Sagnac interferometer’s principle) was used in combination with a table-top wide aperture discharge pumped excimer amplifier to amplify femtosecond UV pulses. It is possible to optimize the operational conditions of the device within a wide range of input energies by changing the optical setup, while keeping the signal-to-noise ratio (short pulse – amplified spontaneous emission (ASE) ratio) of the pulses on a reasonably low value. The amplifier was tested for two different front ends. With ∼40 μJ input energy ∼50 mJ output energy was obtained in a 3-pass arrangement, and applying a seed pulse carrying an energy of around 2–3 mJ a maximum output energy of 100 mJ was reached in a single subpicosecond beam at 248 nm.
Investigation of the Thermal Decomposition of Ketene and of the Reaction CH2 + H2 ⇔ CH3 + H
Authors: Friedrichs G. , Wagner H.Gg.
Published: August 2006

Using frequency modulation (FM) spectroscopy singlet methylene radicals have been detected for the first time behind shock waves. The thermal decomposition of ketene served as source for metylene radicals at temperatures from 1905 to 2780 K and pressures around 450 mbar. For the unimolecular decomposition reaction, (1) CH

As a first study of a methylene reaction at high temperatures by diretly tracing methylene the reaction of methylene with hydrogen, (8 + 9)

log(

A comparison with low temperature literature data and the systematics of activation energies of triplet methylene reactions allowed a consistent description of singlet and triplet contributions and of the forward and reverse reaction.
Quantum Yields for the Photodissociation of Iodine in Compressed Liquids and Supercritical Fluids
Authors: Schwarzer D. , Schroeder J. , Schröder C.
Published: August 2006

Quantum yields of photodissociation were determined for iodine in compressed liquid
Analysis of Vibrationally Highly Excited Bound and Resonance States of DCO (X ˜2A′) Using an Effective Polyad Hamiltonian
Authors: Troellsch A. , Temps F.
Published: August 2006

The vibrational bound and resonance state structure of highly excited DCO (X
Spectrally Resolved Phosphorescence and Slow Fluorescence from Selected Vibronic Levels of Jet-Cooled Glyoxal
Authors: Ottinger Ch. , Winkler T.
Published: August 2006

Trans-glyoxal molecules in a seeded pulsed jet were laser-excited into selected vibrational levels of the T
Delayed Excimer Fluorescence of Fluoranthene Due to Triplet-Triplet Annihilation: Systematic Study of the Fluorescence from a Weakly Bound Excimer
Authors: Gehring M. , Nickel B.
Published: August 2006

Solutions of fluoranthene exhibit a delayed fluorescence (DF) due to triplet-triplet annihilation,
Ab Initio Studies of Complexes of HO2 Radicals with NH3, H2O, and HF
Authors: Lendvay G.
Published: August 2006

A comparative ab initio study was performed to determine the properties of the complexes of HO
Reaction Paths in Concurrence: The Electrochemical Hydrogen Reaction on GaAs(111)A- and GaAs(110)-Surfaces A Quantumchemical Approach
Authors: Engler C. , Hofmann A.
Published: August 2006

We have performed quantumchemical investigations towards a further explanation of the reaction mechanism of the hydrogen evolution reaction on semiconductor electrodes (continuation of Z. Phys. Chem. 210 (1999) 95). Details of the two-step-mechanism via H
Adsorption of Hydrogen Azide on the NaCl(100) Single Crystal Surface. Orientational and Translational Ordering of the HN3 Monolayer as Revealed by PIRS, LEED and Spectra Simulation
Authors: Heidberg J. , Hustedt M. , Oppermann H. , Paszkiewicz P.
Published: August 2006

The adsorption of hydrogen azide HN

Ordered molecular adsorption of HN

Isotopic mixture experiments with H
Effect of Overscreening on the Localization of Hydrated Electrons
Authors: Kornyshev A.A. , Nitzan A.
Published: August 2006

The problem of the ground state of hydrated electron is revisited with a focus on the effects due to nonlocal dielectric response of water. The standard variational analysis is performed. It takes into account – in addition to nonlocal polarization of nuclear modes – the electron repulsion from the closed shells of water molecules, a possibility to form a cavity around the electron and the interaction of the hydrated electron with the high frequency electronic degrees of freedom of water. The classical dielectric continuum limit, shown for a reference, gives the ground state hydration energy that is 2.5 times smaller than the experimental value. The situation alters dramatically if one accounts for the nonlocal dielectric response of water. If one takes literally the existing MD simulation data for the static wave-vector dependent dielectric response function (with an "over-screening" resonance at
Shock Tube Study on the Reaction of Si Atoms with CH3 with Respect to SiC Formation
Authors: Kunz A. , Bhaskaran K.A. , Roth R.
Published: August 2006

The reaction kinetics of ground state Si atoms was studied behind reflected shock waves in the presence of excess CH

Si+CH

↔ SiCH

with
Studies on Charge-Transfer and Hydrogen Bond Formation with Cyproheptadine
Authors: Gangopadhyay J. , Lahiri Sujit Chandra
Published: August 2006

Cyproheptadine, an antihistaminic and antipruritic drug, forms fairly stable charge-transfer complexes with quinone (Q), chloranil (Chl-Q) and anthraquinone (AQ) in chloroform. It also forms stable hydrogen bonds with alcohols (methanol and propanol) and phenols (α-naphthol,

The results suggest that cyproheptadine can form loose association with receptors through charge-transfer and hydrogen bond complex formation.
Thermodynamics of Transfer and Solvatochromism of 1,5-Diaryl-3-Nitroformazans in 1,4-Dioxane–Water Mixtures
Authors: Shehatta I. , Kiwan A.M.
Published: August 2006

The ionization constants of 1,5-diaryl-3-nitroformazans in 20–80%(
Empirical Interatomic Potential from Depolarized Interaction – Induced Light Scattering Spectra for Mercury
Authors: Kader M.S.A.
Published: August 2006

Depolarized interaction-induced light scattering spectra of mercury between 793 K and 1073 K have been used for deriving the empirical multiparameter M3SV interatomic potential. Absolute zeroth and second moments have been measured and compared with theoretical calculations using various models for the interatomic potential. The results show that it is the most accurate potential yet reported for this system.
Initial Observations of Ketene in Flow Reactor Kinetic Studies
Authors: Scire J.J. , Klotz St. D. , Dryer F.L.
Published: August 2006

Variable Pressure Flow Reactor (VPFR) experiments were conducted for ethene/methane mixtures utilizing both FTIR analyses of extracted gas samples and
The CH + N2 Association Reaction at Low Temperatures: Ab Initio MO/VRRKM-Theory Analysis of Temperature and Pressure Effects
Authors: Moskaleva L.V , Lin M.C.
Published: August 2006

The microcanonical variational RRKM formalism combined with high level
Rate Constants Deduced by Ab-Initio Calculations for Decomposition Reactions of CH3OCH2, C4H9OCH2 and C4H8OCH3 Radicals
Authors: Loos A. van der , Vandooren J. , Tiggelen P.J. van , Peeters D.
Published: August 2006

The importance of thermal decompositions during the oxidation of methyl tertbutyl ether (MTBE) has motivated a theoretical investigation of reactions: C
Density of Loosely Bound States in a Triatomic Molecule: The Role of Long Range Interactions
Authors: Heilliette S. , Delon A. , Jost D.T. , Grebenshchikov S.Yu. , Schinke R. , Abel B. , Rayez J.C.
Published: August 2006

The influence of the long range forces between an atom and a diatomic fragment on the density of vibrational bound states is studied theoretically in the vicinity of the dissociation threshold of a model triatomic molecule. In the two-dimensional case (2D), where the non dissociating bond is frozen at the equilibrium geometry, the number of quantum states and their density is shown to increase quickly in a small energy interval close to the dissociation threshold
Ensemble-based Control of Search Dynamics with Application to String Optimization
Authors: Ebeling Werner , Reimann Axel
Published: August 2006

In this paper we demonstrate how ideas from thermodynamics as well as evolutionary biology can be combined to form powerful optimization strategies. These strategies however introduce new parameters to an already parameter dependent optimization task. By testing the introduced strategies with numerous optimization parameter settings for three model problems we develop a semi-automatic parameter adaption which allows an easy control of the free search parameters for potential users.
Biochemical Synthesis in Microstructured Silicon Wafer
Authors: Gebinoga Michael , Schlingloff Gregor , Beck Christine , Thamm Antje , Schober Andreas
Published: August 2006

In biotechnics microsystems have been introduced primarily for analytical purpose in the past few years. Recently miniaturised microtiterplates, so called nanotiterplates, as efficient tools in screening have been discussed.

In a case study we demonstrate the application of cell-free translation or transcription/translation and nucleic acid amplification in such nanotiterplates.

The results show the potential range of applications of nanotiterplates for biotechnology even for biochemical systems, which have not been discussed as miniaturisable in screening.
Algebraic Approach to the Morse Potential and its Coherent States
Authors: Dong Shi-H.
Published: August 2006

A realization of the ladder operators for the 1D Morse potential is presented. These operators satisfy the SU(2) group. The case of anisotropic 3D Morse potential is also discussed if it can be regarded as three 1D Morse potential. The average values of some observables in the coherent states are also calculated.
Electrodeposition of Copper on Pt(111) Pretreated with Organic Adsorbates
Authors: Alonso C. , Salomón A.B. , Abruna H.D.
Published: August 2006

The deposition of copper on Pt(111) has been studied in the underpotential (
Anomalous X-Ray Scattering Studies on Glassy GexSe1−x across the Stiffness Threshold Composition x = 0.20
Authors: Hosokawa S. , Wang Y. , Bérar J.-F. , Greif J. , Pilgrim W.-C. , Murase K.
Published: August 2006

Anomalous x-ray scattering experiments on glassy Ge
Thermodynamics of Dissolution of some Dicarboxylic Acids in Water/Ethane-1,2-Diol Mixtures
Authors: El-Naggar G. A. , Selim S. M. , Zaghloul A. A. , Amira M. F.
Published: August 2006

The p
The Viscosity of n-Decane to High Temperatures of 573 K and High Pressures of 300 Mpa
Authors: Naake Lutz-Dieter , Wiegand Gabriele , Franck Ernst Ulrich
Published: August 2006

The dynamic viscosity of liquid

The viscosity increases at 373 K from 375 to 1602 μPa s in the pressure range from 0.1 to 200 MPa, at 473 K from 200 to 1114 μPa s in the pressure range from 10 to 300 MPa, and at 573 K from 223 to 675 μPa s in the pressure range from 60 to 300 MPa. The mean accuracy of the viscosity measurements is about 1.3 %. A polynomial function describing the viscosity variation with pressure and temperature is given. The maximum average deviation is 0.46 %, the mean average deviation between measured and calculated data is 0.11 %. The viscosity as a function of density is also shown. With Arrhenius plots, the energies of activation are obtained.
Physicochemical Characterization of Inorganic Pigments in the Presence of Gaseous Pollutants. The Role of Ozone
Authors: Siokos V. , Kapolos J. , Roubani-Kalantzopoulou F.
Published: August 2006

The Reversed–Flow Gas Chromatography technique was used to study the interaction of volatile hydrocarbons on three inorganic pigments, namely, CdS, ZnS and Cr
An Interesting Feature of the Vapour Pressure Curve
Authors: Srinivasan K.
Published: August 2006

There exists a maximum in the products of the saturation properties such as
Solid-Solid Phase Transition in Trimethylolpropane (TRMP)
Authors: Chandra D. , Mandalia H. , Chien W.-M. , Lindle D. W. , Rudman R.
Published: August 2006

An orientationally disordered crystalline (ODIC) plastic phase (γ) was observed in Trimethylolpropane (TRMP) during heating by high resolution thermal and X-ray diffraction analyses. TRMP is a potential thermal energy storage material. The enthalpies of solid-solid (α → γ at 327.8 K) and fusion (γ → liquid at 332.7 K) transitions are 16.36 kJ/mol and 0.9 kJ/mol, respectively. Supercooling was observed during solidification of melts, and this supercooled γ phase began to transform to a metastable crystalline phase, designated as α′, after 20 minutes at room temperature. The lattice parameters of the monoclinic α phase, obtained from this study, are:
RNA Pathfinder – Global Properties of Neutral Networks
Authors: Göbel Ulrike , Forst Christian V.
Published: August 2006

Global properties of the genotype-phenotype map induced by RNA secondary structures can be described by random graph theory. The success of this approach depends on details of the respective secondary structure. A small selection of these dependencies, such as stem length, free energy and well-definedness, are analyzed in this paper. In addition, we present an algorithm, which, given a network that complies to a random graph model, provides estimates whether the network is connected or not. The algorithm is linear in time and in the sequence length, local connectivity provided, which is a graph property of the random graph model.
Applications of the Karhunen-Loève Decomposition to Quantum Dynamical Problems
Authors: Dietz H. , Marek M. , Münster A.F. , Engel V.
Published: August 2006

The Karhunen-Loève (KL)-decomposition is a standard method to analyze spatiotemporal patterns which are characteristic for non-linear chemical dynamics on surfaces. We apply the KL-decomposition to quantum dynamical problems. Using a variational principle it is shown how to arrive at the KL-expansion of an arbitrary complex valued function. In the case of an one-dimensional bound state motion, the KL-decomposition yields the eigenstates of the system in a straightforward manner. The time-resolved spectroscopy of an atom-molecule collision serves as another application. We demonstrate that the orthonormal decomposition into KL-modes provides an efficient tool to calculate long-time pump-probe signals.
Intramolecular Photoinduced Electron Transfer in Zwitterionic Quinolinium Dyes – Experimental and Theoretical Studies
Authors: Engel T. , Käb G. , Lanig H.
Published: August 2006

Quinolinium cations and quinolinium betaines were investigated in the representative solvents water and acetonitrile at room temperature using stationary and time-resolved fluorescence spectroscopy (

Experimental results reveal that sulfoalkyl- and carboxyalkyl-quinolinium compounds display a strikingly different behavior in the two solvents. Furthermore, the fluorescence lifetime depends on the length of the spacer for the sulfoalkyl compounds in acetonitrile and the carboxyalkyl compounds in water, respectively. This suggests an intramolecular interaction of the anionic headgroups with the quinolinium system in the excited state. To support this idea, different positions at the chromophore are substituted by a methylgroup in order to perturb the proposed interaction.

With the intention to understand the dynamics of the postulated photoinduced electron transfer from the anionic group onto the excited quinolinium chromophore, semiempirical quantum chemical calculations were performed on the species using the PM3 hamiltonian including solvent effects by a self consistent reaction field (SCRF).

We show that the Marcus theory of electron transfer may serve as a theoretical basis for a natural interpretation of the dynamic fluorescence quenching behavior.
Probing Ethanol-Induced Phospholipid Phase Transitions by the Polarity Sensitive Fluorescence Probes Prodan and Patman
Authors: Hutterer R. , Hof M.
Published: August 2006

The emission behaviour of the two polarity sensitive probes Prodan and Patman in phospholipid vesicles was studied as a function of the concentration of ethanol. Comparing the spectral shifts in both the symmetric lipid 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) showing a phase transition from a normal to a fully interdigitated gel phase and the strongly asymmetric lipid 1-stearoyl-2-lauroyl-sn-glycero-3-phosphatidylcholine (C(18):C(12)-PC) favouring a mixed interdigitated gel phase we show that the huge red shifts of Prodan in presence of higher ethanol concentrations cannot be easily attributed to a specific lipid phase transition. Rather, probe relocation and a pronounced increase in solvent relaxation (SR) as monitored by time-resolved emission spectra (TRES) in presence of ethanol contribute to the large shifts observable in both lipid systems in case of Prodan. While Patman exhibits a red shift caused by increased SR due to the ethanol induced formation of a fully interdigitated phase in DPPC, hardly any shift occurs in C(18):C(12)-PC, which is supposed not to undergo an ethanol-induced phase transition.
Effects of Statistical Fluctuations in a Model of Tropospheric Chemistry
Authors: Münster A.F.
Published: August 2006

We present numerical simulations of the ozone concentration in the troposphere based on a six-variable model of tropospheric chemistry. Although the model is not meant to describe the detailed mechanism of tropospheric chemistry it contains nonlinear steps leading to oscillatory behaviour. Statistical noise imposed upon the emission intensity of nitric oxide may lead to the interesting phenomenon of "internal signal stochastic resonance". Here the imposed noise amplifies oscillatory dynamics of the system under conditions which lead to a stable stationary state in the absence of noise. A combination of statistical perturbations with a slow modulation of the rates of photosensitive steps allows to qualitatively reproduce observed time series of the ozone concentration.
Yield Effects in Single and Coupled Nonlinear Thermokinetic Reaction Systems
Authors: Zeyer K.-P. , Mangold M. , Shah S. , Kienle A. , Gilles Ernst-Dieter
Published: August 2006

The influence of nonlinear dynamic effects on yield is considered for consecutive-parallel reaction schemes in a single phase CSTR. In the first part, the behavior of a single uncoupled reactor is investigated. Emphasis is on the reaction dynamics and the yield of the intermediate ethanal using continuation and optimization techniques. We characterize regions of periodic, complex periodic, and chaotic oscillations. The chaotic region is reached by type III intermittency. In all cases, the global optimum yield of the intermediate is a steady state, which is unstable or stable due to the location of the stability boundary. It is found that autonomous periodic operation is only locally better than steady state operation. In the second part, different types of mass and energy coupling between two reactors are studied. The results obtained for a simple consecutive parallel reaction scheme are validated by a more detailed model of the ethanol oxidation by hydrogen peroxide under iron(III) catalysis, which can be described by an extended consecutive-parallel reaction scheme. Analogies are found with respect to the dynamics and the yield of the intermediate.
Fold–Hopf Bursting in a Model for Calcium Signal Transduction
Authors: Brusch Lutz , Lorenz Wolfram , Or-Guil Michal , Bär Markus , Kummer Ursula
Published: August 2006

We study a recent model for calcium signal transduction. This model displays spiking, bursting and chaotic oscillations in accordance with experimental results. We calculate bifurcation diagrams and study the bursting behaviour in detail. This behaviour is classified according to the dynamics of separated slow and fast subsystems. It is shown to be of the Fold–Hopf type, a type which was previously only described in the context of neuronal systems, but not in the context of signal transduction in the cell.
On the possibility of the Observation of Intramolecular Reaction Dynamics in Liquids by Time-resolved X-ray Scattering
Authors: Techert S. , Schmatz S.
Published: August 2006

The feasibility of time-resolved structural studies using pulsed X-ray radiation from a 3rd generation synchrotron is discussed and compared with scattering experiments which might be possible with a future free electron laser (X-FEL). As an example, it is shown that the structural changes during the isomerisation process of trans-stilbene into cis-stilbene can be observed using time-resolved X-ray diffraction in the gas-phase as well as in solution.
On the sudden Limit in the Capture of Particles for Long-Range Anisotropic Interactions
Authors: Dashevskaya E.I. , Maergoiz A. I. , Ushakov V.G.
Published: August 2006

The capture cross sections and rigidity factors for atom-linear rotor anisotropic interaction proportional to
Particle Entropies and Entropy Quanta. III. The van der Waals Gas
Authors: Zimmermann Herbert W.
Published: August 2006

The statistical thermodynamics of the van der Waals gas is treated by means of the particle entropies σ
Kinematical Description of Meandering Spiral Waves in Active Media
Authors: Braune M. , Engel H.
Published: August 2006

Under certain conditions the dynamics of spiral waves in active media can be described within a kinematical approach. We discuss the importance of curvature effects for the transition from rigidly rotating to outward meandering spirals. To include these effects into the kinematical description we propose a modified boundary condition for the curvature at the tip. This allows to recover a variety of rotation regimes with hypocycloid-like trajectories of the spiral tip corresponding to outward meandering spiral waves which are frequently observed experimentally in active media of quite different nature beyond the instability of rigid rotation.
The Role of Nucleophiles in the Kinetics of Decomposition of Benzyltriphenyl-Phoshponium Chloride in Different Media
Authors: Khalil F.Y. , Hanna M. , El-Batouti M. , Mikhail A.A.
Published: August 2006

The alkaline decomposition of benzyltriphenylphosphonium chloride was studied kinetically in a series of DMSO-H
The Surface Roughness of a Silver Electrode during Electrocrystallization in Cyanide Electroplating Bath
Authors: Baltrunas G. , Pakalniene E. , Popkirov G.S. , Schindler R.N.
Published: August 2006

The effect of CN
Generation of New Acidic Sites by Dispersing Zinc Oxide Fine Particles on Silica
Authors: Miyao T. , Kitai M. , Ogita T. , Naito S.
Published: August 2006

New acidic sites were generated on finely dispersed ZnO particles supported on silica prepared by impregnation method. Ammonia-TPD, XPS, XRD, TEM and catalytic measurements revealed that the acidic properties on the nano-sized amorphous particles of ZnO were quite different from homogeneous ZnO-SiO
The Photolysis of Fluorine at 366 nm in the Presence of Bis(Fluoroformyl)Peroxide
Authors: Croce A.E. , Tori C. A. , Castellano E.
Published: August 2006

The photolysis of molecular fluorine at 366 nm in the presence of bis(fluoroformyl)peroxide, (FCO)

F

F + FC(O)OO(O)CF → FC(O)OF + FC(O)OF (2)

F + FC(O)OO(O)CF → F

F + FC(O)O → FC(O)OF (4)

2F

F → ½F

On the other hand, Φ decreases with increasing O

F + O

FO

F + FO

The formation of CF

F + CF

followed by a secondary mechanism, being
Circadian rhythms and reproduction
Authors: Boden Michael J , Kennaway David J
Published: August 2006

There is a growing recognition that the circadian timing system, in particular recently discovered clock genes, plays a major role in a wide range of physiological systems. Microarray studies, for example, have shown that the expression of hundreds of genes changes many fold in the suprachiasmatic nucleus, liver heart and kidney. In this review, we discuss the role of circadian rhythmicity in the control of reproductive function in animals and humans. Circadian rhythms and clock genes appear to be involved in optimal reproductive performance, but there are sufficient redundancies in their function that many of the knockout mice produced do not show overt reproductive failure. Furthermore, important strain differences have emerged from the studies especially between the various Clock (Circadian Locomotor Output Cycle Kaput) mutant strains. Nevertheless, there is emerging evidence that the primary clock genes, Clock and Bmal1 (Brain and Muscle ARNT-like protein 1, also known as Mop3), strongly influence reproductive competency. The extent to which the circadian timing system affects human reproductive performance is not known, in part, because many of the appropriate studies have not been done. With the role of Clock and Bmal1 in fertility becoming clearer, it may be time to pursue the effect of polymorphisms in these genes in relation to the various types of infertility in humans.
Phenotypic abnormalities observed in aged cloned mice from embryonic stem cells after long-term maintenance
Authors: Shimozawa Nobuhiro , Sotomaru Yusuke , Eguchi Natsuko , Suzuki Shuzo , Hioki Kyoji , Usui Toshimi , Kono Tomohiro , Ito Mamoru
Published: August 2006

Somatic/embryonic stem cell cloning has made it possible to produce an individual genomically identical to another individual. However, the cloned animals have a variety of abnormalities caused by the aberrant gene modification, with insufficient reprogramming in cloning. We previously reported abnormalities in cloned mice at birth. In this study, we examined what abnormalities could be seen in cloned mice after long-term maintenance. The aged cloned mice showed multiple abnormalities: increase of body weight, some phenotypic abnormalities in the kidneys, testes and thymus, and lower urea nitrogen in their serum biochemical values. The kidneys of all cloned mice were hypertrophied, with a metamorphic or whitish appearance. The multiple lesions, including the enlarged renal pelvis and distension of the renal veins in histology, might be the result of urine accumulation by urinary tract obstruction. The testes of the cloned mice were atrophied, and showed no sperm formation in histology. In contrast, the thymus was rather hypertrophied, and a comparably increased number of lymphocytes were observed in the medulla, consisting mainly of T cells. By conducting a progeny test between the cloned mice, it was confirmed that these abnormalities in the aged cloned mice were not transmitted to their offspring, indicating that the incomplete reprogramming in clones might be in part responsible for the abnormalities detected in aged clones. These results indicate that the postnatal abnormalities observed in aged cloned mice are varied and can be restored through the germ line.
Expression of caspase-2, -3, -8 and -9 proteins and enzyme activity in the corpus luteum of the rat at different stages during the natural estrous cycle
Authors: Peluffo Marina C , Bussmann Leonardo , Stouffer Richard L , Tesone Marta
Published: August 2006

Apoptosis is associated with the regression of the corpus luteum (CL) in many species. Since caspases play a central role in apoptosis, we studied several initiators (-2, -8, and -9) and the main effector (-3) caspase in the CL during the estrous cycle of the rat. Two different populations of CL (old and new) were identified on ovaries at estrus and diestrus II (DII). Diminished (P < 0.05) luteal progesterone content and P450scc levels suggested that functional luteolysis occurred between the new CL at DII and old CL at estrus, whereas the decline (P < 0.05) in luteal weight indicated that structural regression was occurring between old CL at estrus to DII. Immunostaining for caspase-2 in luteal and endothelial cells appeared to increase as the luteal phase progressed, peaking at DII in the old CL. However, caspase-8 and -9 immunostaining showed little change with a slight increase at estrus in the old population. Notably, caspase-3 staining appeared to peak at DII in the new CL. Enzyme activity of caspase-9 increased (P < 0.05) in the new CL at DII, followed by that of caspase-2 and -3 in old CL at estrus. Caspase-8 activity did not change at any stage. The number of apoptotic cells increased at DII in the old CL. These results suggest an important role for this protease family during early events of luteolysis in the rat estrous cycle.
Molecular cloning, testicular postnatal expression, and oocyte-activating potential of porcine phospholipase Cζ
Authors: Yoneda Akihiro , Kashima Masashi , Yoshida Shigeki , Terada Kei , Nakagawa Shoma , Sakamoto Akiko , Hayakawa Koji , Suzuki Keita , Ueda Junji , Watanabe Tomomasa
Published: August 2006

The molecular mechanism by which sperm triggers Ca2+ oscillation, oocyte activation, and early embryonic development has not been clarified. Recently, oocyte activation has been shown to be induced by sperm-specific phospholipase Cζ (PLCζ). The ability of PLCζ to induce oocyte activation is highly conserved across vertebrates. In the present study, porcine PLCζ cDNA was identified and the nucleotide sequence was determined. The expression pattern of porcine PLCζ mRNA during the period of postnatal testicular development was shown to be similar to that of mouse PLCζ. PLCζ mRNA expression in the pig and mouse was detected only in the testes when the elongated spermatids had differentiated, and was detected from day 96 after birth in the pig. Histological examination of porcine testis during the period of postnatal development revealed the presence of spermatozoa from day 110 after birth. These findings suggest that the synthesis of PLCζ mRNA starts when spermiogenesis is initiated. Microinjection of porcine PLCζ complementary RNA into porcine oocytes demonstrated that porcine PLCζ has the ability to trigger repetitive Ca2+ transients in porcine oocytes similar to that observed during fertilization. It was also found that porcine PLCζ cRNA has the potential to induce oocyte activation and initiate embryonic development up to the blastocyst stage.
17β-Estradiol induces Akt-1 through estrogen receptor-β in the frog (Rana esculenta) male germ cells
Authors: Stabile Veronica , Russo Maria , Chieffi Paolo
Published: August 2006

Several lines of evidence support the key role of estrogens in male fertility. Here, we investigate the regulation of the serine/threonine kinase Akt-1 in the frog (Rana esculenta) testis during the annual sexual cycle and, whether 17β-estradiol (E2) exerts a role in the Akt-1 activity. Akt-1 has been shown to be the mediator of growth factor-dependent cell proliferation, survival, and metabolism in a variety of cell types.

First, we demonstrate by immunohistochemistry, the presence of estrogen receptor-β (ERβ), and Akt-1 in the spermatogonia (SPG), spermatocytes (SPC), and spermatids (SPT). Western-blot analysis revealed that ERβ isoform (molecular weight 55 kDa) was highly expressed in May (reproductive period) with respect to January and November (winter stasis); in parallel, Akt-1 (molecular weight 60 kDa) is highly phosphorylated (Ser-473) during the period of active spermatogenesis (May) compared with the winter stasis (January and November). In addition, in vitro experiments demonstrate that E2 treatment induces the activation of Akt-1, and this effect is counteracted by the anti-estrogen ICI 182–780. In conclusion, our data show that E2 induces Akt-1 phosphorylation (Ser-473) possibly via ERβ in frog (R. esculenta) male germ cells.
SSLP-1, a secreted Ly-6 protein purified from mouse seminal vesicle fluid
Authors: Li Sheng-Hsiang , Lee Robert Kuo-Kuang , Lin Ming-Huei , Hwu Yuh-Ming , Lu Chung-Hao , Chen Ying-Jie , Chen Hsuan-Chiang , Chang Wen-Hwei , Chang Wei-Chao
Published: August 2006

The Ly-6 protein family refers to a group of glycophosphatidyl inositol-anchored membrane proteins with ten conserved cysteines. They are thought to be involved in cellular adhesion and signaling. Recently, a subfamily of secreted Ly-6 proteins has been identified. In the present study, we report a secreted Ly-6 protein, secreted seminal vesicle Ly-6 protein 1 (SSLP-1) purified from mouse seminal vesicles using a series of steps including ion-exchange chromatography on a diethylaminoethyl (DEAE)-Sephacel column, gel filtration on a Sephadex G-75 column, and ion-exchange HPLC on a sulfopropyl column. Further analysis demonstrated it to be a novel, previously unnamed, 17 kDa glycoprotein. N-glycosidase F treatment revealed a core protein with a molecular mass of 8720 Da. By Basic Local Alignment Search Tool Protein analysis, we found that SSLP-1 had ten conserved cysteine residues identical with other secreted Ly-6 proteins. The gene Gm191, which is located on chromosome 9, encodes SSLP-1. By Northern blotting with 21 different mouse tissues, we found that Sslp-1 mRNA was predominantly expressed in the seminal vesicle. Immunohistochemistry revealed SSLP-1 protein in the luminal fluid and mucosal epithelium of the seminal vesicles. The amount of Sslp-1 mRNA and SSLP-1 protein in the seminal vesicle was regulated by testosterone and correlated with the stage of animal maturation. The tissue-specific expression pattern suggests that SSLP-1 may play a physiological role in male mouse reproduction.
Evaluation on the phagocytosis of apoptotic spermatogenic cells by Sertoli cells in vitro through detecting lipid droplet formation by Oil Red O staining
Authors: Wang Huizhen , Wang Haikun , Xiong Weipeng , Chen Yongmei , Ma Quanhong , Ma Jing , Ge Yehua , Han Daishu
Published: August 2006

During spermatogenesis, more than half of the differentiating spermatogenic cells undergo apoptosis before they mature into spermatozoa. Ultrastructure studies showed that the formation of lipid droplets in Sertoli cells was associated with phagocytosis of residual bodies and apoptotic germ cells by Sertoli cells. Here, a relationship between the phagocytosis of apoptotic spermatogenic cells and lipid droplet formation in Sertoli cells was studied in vitro by Oil Red O (ORO) staining. The results confirmed that the formation of lipid droplets was a result of phagocytosis of apoptotic spermatogenic cells in Sertoli cells. By comparing phagocytosis of apoptotic spermatogenic cells and thymocytes by Sertoli cells to that by macrophages, we demonstrated that the lipid droplets accumulation in phagocytes depended on phagocytosed apoptotic cell type, but not phagocyte type. However, the size of lipid droplets was related to the type of phagocytes. By this approach, we found that Sertoli cells at different postnatal stages of development had a similar phagocytic ability. These results suggested that the detection of lipid droplets by ORO staining was a practical method to evaluate the phagocytic functions of Sertoli cells in vitro. This approach could also be considered as an in vitro model to study the lipid formation, metabolism, and function in Sertoli cells.
A Prospective Controlled Study of Neurodevelopment in HIV-Uninfected Children Exposed to Combination Antiretroviral Drugs in Pregnancy
Authors: Alimenti Ariane , Forbes John C. , Oberlander Tim F. , Money Deborah M. , Grunau Ruth E. , Papsdorf Michael P. , Maan Evelyn , Cole Lesley J. , Burdge David R.
Published: August 2006

OBJECTIVE. Our intent was to investigate the neurodevelopment of HIV-uninfected children exposed to combination highly active antiretroviral therapy in pregnancy compared with children not exposed to highly active antiretroviral therapy but with similar socioeconomic backgrounds.

PATIENTS AND METHODS. A prospective controlled cross-sectional study of the neurodevelopment of children exposed to highly active antiretroviral therapy versus those not exposed was performed by using the Bayley Scales of Infant Development and Vineland Adaptive Behavior Scales at 18 to 36 months of age. The highly active antiretroviral therapy–exposed children were born to HIV-infected women but were uninfected themselves. The control children were born to HIV-uninfected women with similar anticipated socioeconomic background (hepatitis C infected and high proportion of substance use). Sociodemographic, clinical, highly active antiretroviral therapy (antenatal, intrapartum, neonatal), and substance-use histories were collected. Results were compared by using analyses of covariance and χ2 analysis.

RESULTS. Thirty-nine highly active antiretroviral therapy–exposed and 24 control children were assessed. All mean scores were lower for those in the highly active antiretroviral therapy–exposed group than those in the control group (Bayley Mental Development Index: 85.4 vs 94.3; Bayley Psychomotor Development Index: 93.4 vs 96.6; Vineland mean communication score: 90.1 vs 94.4; Vineland mean daily-living score: 91.2 vs 93.6; Vineland mean socialization score: 97.1 vs 98.4). However, when maternal substance use during pregnancy was controlled for, there were no significant differences between the groups in any domains assessed. Children in both groups exposed to maternal substance use scored significantly lower than children not exposed in all domains except communication skills. It is important to note that there were no differences between the highly active antiretroviral therapy–exposed children with no substance exposure and the control children with no substance exposure in any of the scores.

CONCLUSIONS. HIV- and highly active antiretroviral therapy–exposed HIV-uninfected children had lower development and adaptive behavior scores when compared with children who had not been exposed. However, these differences were not significant after correcting for maternal substance use, which had a greater impact on neurodevelopment than highly active antiretroviral therapy exposure. These results suggest that perinatal highly active antiretroviral therapy exposure is not associated with altered development and behavior at 18 to 36 months of age.
Sugars, hormones, and environment affect the dormancy status in underground adventitious buds of leafy spurge (Euphorbia esula)
Authors: Chao Wun S. , Serpe Marcelo D. , Anderson James V. , Gesch Russ W. , Horvath David P.
Published: August 2006

Signals from both leaves and apical or axillary meristems of leafy spurge are known to inhibit root bud growth. To test the hypothesis that carbohydrates and growth regulators affect root bud growth, decapitated leafy spurge plants were hydroponically treated with glucose, sucrose, gibberellic acid (GA), abscisic acid (ABA), 1-naphthaleneacetic acid (NAA), 6-benzylaminopurine (BA), and a GA biosynthesis inhibitor, paclobutrazol. Both glucose and sucrose caused suppression of root bud growth at concentrations of 30 mM. The inhibitory effect of sucrose was counteracted by GA at 15 μM. In contrast, BA, ABA, NAA, and paclobutrazol inhibited root bud growth at concentrations as low as 1, 2, 1, and 16 μM, respectively. Sugar and starch levels were also determined in root buds at various times after decapitation. Buds of intact plants contained the highest level of sucrose compared with buds harvested 1, 3, and 5 d after decapitation. To determine how seasonal changes affect root bud dormancy, growth from root buds of field-grown plants was monitored for several years. Root buds of field-grown leafy spurge had the highest level of innate dormancy from October to November, which persisted until a prolonged period of freezing occurred in November or early December. Our data support the hypothesis that carbohydrates may be involved in regulating dormancy status in root buds of leafy spurge.
The Electroshock Quotationary
Authors: Frank Leonard Roy
Published: August 2006

Since its introduction in 1938, electroshock has been the subject of intense controversy; there appears to be little if any middle ground between the positions taken by its proponents and opponents. The author/editor, himself an insulin coma-electroshock survivor, has for more than 30 years actively opposed any use of electroshock on the grounds that the procedure is inherently destructive and dehumanizing. The Introduction briefly describes the nature of the controversy, provides background information, lists the diagnoses for which ECT is (or has been) used and its effects, describes the method of administration, offers some answers to the question of why it seems to “work” in certain instances, lists some of the well-known individuals who have undergone the procedure, and closes with a short overview of the current situation. The text presents a historical perspective on ECT in the form of 78 chronologically arranged excerpts from professional and lay writings. Included are descriptions by survivors of their experience with ECT and how it affected their lives, as well as reports and claims regarding clinical and nonclinical uses of ECT, its effectiveness and ineffectiveness, and its safety and danger (especially brain damage, memory loss, learning disability, and death).
Assessment of the Knowledge and Beliefs of Finnish Medical Students regarding HIV Infection and Participation in AIDS Vaccine Trials
Authors: Onigbogi Olanrewaju O. , Kauhanen Jussi , Miettola Erkki J.
Published: August 2006

This study sought to determine the level of general knowledge about HIV infection among Finnish medical students and their willingness to participate in AIDS vaccine trials. One hundred and sixty-two volunteer medical students at the University of Kuopio in the 2nd and 5th years of training filled self-administered questionnaires. The overall response rate among the 2nd year students was 77%, and among the 5th year students 70%. Knowledge was scored on a percentage scale. The mean score on general knowledge about HIV among 2nd year students was 75.6 ( SD = 0.23) while in the 5th year it was 87.8 ( SD 0.18). Fifty-four students (77%) from the 5th year and 66 (72%) from the 2nd year indicated their willingness to participate (WTP) in AIDS vaccine trials ( p = 0.09). Medical curricula should be constantly revised to keep medical students up-to-date about recent advances in HIV/AIDS research.
Bridging the Gap between Community Health and K-12 Schools
Authors: Ahmed Christine
Published: August 2006

The topic of this article is program planning for K–12 school health programs collaborating with community agencies, businesses, colleges, and organizations. Community involvement was listed as one of the weakest areas of school health efforts in a national coordinated school health study [1]. This article presents the 5-year results demonstrating the outcomes of K–12 schools program planning aimed at community involvement in the coordinated school health model. Directors of the Departments of Education and Health in South Dakota initiated training for school personnel in the coordinated school health model through development of councils in the schools starting in 2000. The expectations of the councils were to design a program plan to support the health of students and staff in their school. The short-term results of a 5-year evaluation indicated the greatest area of gain was in community health involvement to improve student and staff health.
Proximate Determinants of Fertility in Bangladesh
Authors: Kabir Ahmad , Islam Mohammad Shahidul , Patwari Mohammad Ismail
Published: August 2006

Using data derived from the 1989 Bangladesh Fertility Survey and the 1999–2000 Bangladesh Demographic and Health Survey, this article investigates the impact of four intermediate fertility variables—namely marriage, contraception, lactational infecundability, and induced abortion—on fertility in Bangladesh. The contribution of each proximate variable was observed through the decomposition of the total fertility rate (TFR) into proximate components. Contraception is seen to be the most prominent determinant in lowering the total fertility rate (from 5.1 to 3.3 or about 38.5%) between 1989 and 2000.
Advanced Ceramic Materials for High Temperature Applications
Authors: Belmonte M.
Published: August 2006

The increasing interest in ecological aspects related to the reduction of harmful emissions to the atmosphere and, at the same time, the need to achieve higher efficiencies of energy production are the driving forces that justify the current development of advanced ceramic materials for high temperature applications, namely those associated to energy and transportation industries. Ceramic matrix composites (CMCs), thermal barrier coatings (TBCs), environmental barrier coatings (EBCs) and solid oxide fuel cells (SOFCs) are increasingly used to work under the new demanding conditions. In this review, the recent progress and trends in the research and development of CMCs, TBCs, EBCs and SOFCs based on ceramic materials for high temperature applications are highlighted.
Feasibility Study of Brazing Aluminium Alloys Through Pre‐Deposition of a Braze Alloy by Cold Spray Process
Authors: Zhao L. , Bobzin K. , Ernst F. , Zwick J. , Roesing J. , Lugscheider E.
Published: August 2006

Cold spray process is a relatively new coating process with several special properties which are interesting for brazing technology. In the study, a braze alloy Al12Si was deposited onto aluminium alloy 6063 by cold spray process. The deposited samples were heat‐treated at 500 and 615 °C. Due to the rupture of oxide scale on braze alloy particles and substrates, a diffusion process occurred between the particles and between the particles and substrates during heat‐treatments. The deposited samples could be well brazed with uncoated counter parts both under argon atmosphere as well as in air with fluxes. The results show that pre‐deposition of braze alloys by cold spray process can be a very useful tool for brazing aluminium alloys.
The Influence of Magnetic Fields on the Mechanical Behaviour of Granular Materials Used for Foundry Moulding: Numerical and Experimental Analysis
Authors: Geffroy P.‐M. , Goni J. , Pena X. , Bernard D. , Silvain J.‐F.
Published: August 2006

Understanding the mechanical behaviour of granular materials is of financial importance in many industries, including the geotechnical [1], pharmaceutical and foundry sectors. In the latter, granular materials are used as mould elements for lost foam (sand) and magnetic moulding (steel shot) processes. This study focuses on optimising mould geometry and magnetic field characteristics (intensity and orientation) to obtain the desired dimensions of the final product.