bluuebunny/crossref_metadata_2025 huggingface dataset:
Targeting of Sebocytes by Aminolevulinic Acid‐dependent Photosensitization
Authors: Kosaka Sachiko , Kawana Seiji , Zouboulis Christos C. , Hasan Tayyaba , Ortel Bernhard
Published: October 2005

Photodynamic therapy using 5‐aminolevulinic acid‐induced protoporphyrin IX has been developed as a very useful therapeutic modality. Recently, several authors have reported on the efficacy of this procedure for acne. This approach is based on the fact that 5‐aminolevulinic acid‐induced protoporphyrin IX has strong selectivity for sebaceous glands. We used the immortalized human sebaceous gland cell line SZ95 to investigate cellular mechanisms of photodynamic therapy using 5‐aminolevulinic acid‐induced protoporphyrin IX. Quantification of induced protoporphyrin IX production showed dependence on the applied 5‐aminolevulinic acid dose. When SZ95 sebocytes were differentiated by arachidonic acid treatment, there was no difference between them and the control cells with respect to both the amount of 5‐aminolevulinic acid‐induced protoporphyrin IX and the phototoxic effects. We altered protoporphyrin IX formation rates by growing cells scattered as single cells in the culture dishes. Single cells produced significantly lower protoporphyrin IX levels than those grown with intercellular contacts. Intracellular localization of protoporphyrin IX was imaged using confocal laser scanning microscopy. The differentiation‐specific lipid droplets were virtually excluded from protoporphyrin IX fluorescence. In addition to weak mitochondrial and strong membrane fluorescence, distinctive spots with strong fluorescence were observed. These did not colocalize with fluorescent probes for mitochondria, lysosomes or the Golgi apparati.
Pyrene Excimer Fluorescence of Yeast Alcohol Dehydrogenase: A Sensitive Probe to Investigate Ligand Binding and Unfolding Pathway of the Enzyme
Authors: Santra Manas Kumar , Dasgupta Debjani , Panda Dulal
Published: October 2005

The cysteine residues of yeast alcohol dehydrogenase (YADH) were covalently modified by N‐(1‐pyrenyl) maleimide (PM). A maximum of 3.4 cysteines per YADH monomer could be modified by PM. The secondary structure of PM‐YADH was found to be similar to that of the native YADH using far‐UV circular dichroism. The covalent modification of YADH by PM inhibited the enzymatic activity indicating that the active site of the enzyme was altered. PM‐YADH displayed maximum excimer fluorescence at an incorporation ratio of 2.6 mol of PM per monomeric subunit of YADH. Nucleotide adenine dinucleotide (NAD) divalent zinc and ethanol reduced the excimer fluorescence of PM‐YADH indicating that these agents induce conformational changes in the enzyme. Guani‐dinium hydrochloride (GdnHCl)‐induced unfolding of YADH was analyzed using tryptophan fluorescence, pyrene excimer fluorescence and enzymatic activity. The unfolding of YADH was found to occur in a stepwise manner. The loss of enzymatic activity preceded the global unfolding of the protein. Further, changes in tryptophan fluorescence with increasing GdnHCl suggested that YADH was completely unfolded by 2.5 M GdnHCl. Interestingly, residual structures of YADH were detected even in the presence of 5 M GdnHCl using the excimer fluorescence of PM‐YADH.
Microencapsulation
Authors: Thies Curt
Published: October 2005

This article discusses the concept of microencapsulation, many processes by which microcapsules are produced, and a number of microcapsule applications. Nomenclature and selected materials used to form microcapsules are summarized briefly. Encapsulation processes discussed include complex coacervation, polymer–polymer incompatibility, interfacial andin situpolymerization, solvent evaporation, extractive drying, submerged stationary nozzle, centrifugal nozzle, spray drying, fluidized bed, and rotational suspension separation. Microcapsule applications discussed include graphic arts, including carbonless copy paper; prolonged herbicides and insecticides; oral and injectable pharmaceuticals; live cell immobilization for biomedical and biotechnological applications; enhanced performance of food ingredients, such as flavors and vitamins; and several general consumer uses, such as cosmetics and adhesives.
Nitrobenzene and Nitrotoluenes
Authors: Dugal Markus
Published: October 2005

Nitrobenzene is a pale yellow to yellowish brown liquid with a boiling point of 207–212°C, depending on its purity. It is a very toxic substance with a maximum allowable concentration (PEL) of 1 ppm. The commercial production of nitrobenzene involves the direct nitration of benzene using a mixture of nitric and sulfuric acids, with typical yields of 96–99%. The main derivatives of nitrobenzene are
ortho
‐,
meta
‐, and
para
‐nitrochlorobenzene. These are toxic, with a PEL of 0.1 ppm for
p
‐nitrochlorobenzene.

Nitrotoluene exists as three isomers:
o
‐,
m
‐, and
p
‐nitrotoluene. The
o
‐ and
m
‐nitrotoluenes are clear yellow liquids at 25°C, whereas
p
‐nitrotoluene is a crystalline solid (mp 53.5°C). The nitrotoluenes are fairly toxic, with a PEL of 2 ppm.
Nitrides
Authors: Roberts Kenneth L. , Covington Leroy
Published: October 2005

Nitrides may be classified as being ionic or salt‐like, metallic, nonmetallic (diamond‐like) or volatile. The properties of transition‐metal metallic nitrides and the diamond‐like nonmetallic nitrides are described. Additionally, sulfur and phosphorus form polymeric nitride species. Transition‐metal binary nitrides, made on a small scale, are used for high strength and hardness primarily as refractory coatings. Boron, aluminum, and silicon nitrides find use as refractories, ablative materials, abrasives, and coatings. The combination of high thermal conductivity, high electrical resistivity and linear thermal expansion coefficient makes aluminum nitride a sufficient ceramic material for electronic applications. Several powder‐specific synthesis methods for aluminum nitride are described and the effects of oxygen and impurity contamination are mentioned. Lithium nitride finds application in batteries and catalysts. Gallium and indium nitrides are used in such optoelectronic devices as light‐emitting diodes. The material and electrical properties of gallium nitride (GaN) position it as a prime candidate for high power microwave applications. GaN has shown extensive potential in the microelectronics environment for high electron mobility transistors. The manufacture and processing of nitride coatings by case hardening is presented as well as the processing of the structurally important silicon nitride. A brief summary of the optical and electronic properties, including optical adsorption and field emission, of carbon nitride are also presented. Plasma enhanced and hot filament chemical vapor deposition techniques are highlighted as two of the most current preparation methods used to obtain carbon nitride films.
Nuclear Fuel Reserves
Authors: Bullen Daniel B.
Published: October 2005

The primary fuel for light‐water nuclear reactors is natural or slightly enriched (3–5%) uranium dioxide. Estimates of the world reserves of uranium resources are based on the cost of recovery for various ore types and classified as reasonably assured, estimated, or additional, speculative resources. World reactor‐related requirements are expected to increase from usage through the year 2010. Additional sources of uranium are expected to come from the use of reprocessed plutonium in mixed‐oxide fuels, the deenrichment of weapon‐grade, high enriched uranium with natural uranium, and the fabrication of mixed‐oxide fuels using surplus weapons‐grade plutonium.
Superconductivity and Superconductors
Authors: Glowacki Bartek. A.
Published: October 2005

This article aims to address the issue of superconductivity and superconductors from the point of view of technology and applications, despite the fact that the majority of recent developments relate more to the fundamental aspects of superconductivity. The technology sections focus on the discovery of superconductivity and the phenomena and characteristics that define it. Low temperature superconductors (LTS) are discussed. Niobium and tantalum devices fall into this category. These materials are probably the most important electrode material for tunnel junction fabrication and are used in superconducting devices, eg, the superconducting quantum interference device (SQUID), X‐ray detectors, optical detectors, and mixers. Magnesium dibromide has made us aware of the possibility of the existence of new superconducting materials and this compound is detailed. High temperature ceramic superconductors are discussed and they focus mainly on the evolution of superconductivity by chemical doping of copper and its compounds. An extensive section on application includes details on the following uses: in transmission cables, research electromagnets, electromagnets for nmr and mri systems, current leads, fault current limiters, magnetically guided surgical instruments, and levitating train, to name a few.
A new method for critical points calculation from cubic EOS
Authors: Nichita Dan Vladimir
Published: October 2005

Development of accurate and efficient methods for direct calculation of critical points is valuable for phase equilibrium calculations in chemical and petroleum engineering. A new method for critical points calculation is developed. For critical point calculation methods, the spinodal equation is given by setting to zero a determinant of nc (number of components) or nc‐1 order, containing second‐order derivatives of thermodynamic potentials. In this approach, this determinant has a lower order, which does not depend on the number of components in the mixture, but on the number of reduction parameters, with no restrictions on the binary interaction parameters (BIPs). The new method has been tested for several mixtures having various phase diagram shapes, and proved its reliability. The computation effort for each step for correcting temperature and molar volume can be significantly reduced. The proposed method is particularly efficient for mixtures with many components and few nonzero BIPs. Cubic two‐parameter EOS are used; however, the proposed method can be applied for any EOS that observes the restrictions of the Reduction Theorem. © 2005 American Institute of Chemical Engineers AIChE J, 2006
Cover Picture: The Design and Evaluation of Heparin‐Binding Foldamers (Angew. Chem. Int. Ed. 41/2005)
Authors: Choi Sungwook , Clements Dylan J. , Pophristic Vojislava , Ivanov Ivaylo , Vemparala Satyavani , Bennett Joel S. , Klein Michael L. , Winkler Jeffrey D. , DeGrado William F.
Published: October 2005

Small inhibitors for low‐molecular‐weight heparin, namely short aryl amide foldamers, were designed with the aid of molecular‐dynamics calculations. The cover picture shows that the binding is primarily dominated by electrostatic interactions between a pentasaccharide sequence of heparin and the antagonist. In their Communication on page 6685 ff., W. F. DeGrado and co‐workers show that heparin binds and modulates the biological properties of a number of proteins, including antithrombin II and factor Xa.
How can a β‐sheet peptide be both a potent antimicrobial and harmfully toxic? Molecular dynamics simulations of protegrin‐1 in micelles
Authors: Langham Allison A. , Khandelia Himanshu , Kaznessis Yiannis N.
Published: October 2005

In this work, the naturally occurring β‐hairpin antimicrobial peptide protegrin‐1 (PG‐1) is studied by molecular dynamics simulation in all‐atom sodium dodecylsulfate and dodecylphosphocholine micelles. These simulations provide a high‐resolution picture of the interactions between the peptide and simple models of bacterial and mammalian membranes. Both micelles show significant disruption, as is expected for a peptide that is both active against bacteria and toxic to host cells. There is, however, clear differentiation between the behavior in SDS versus DPC, which suggests different mechanisms of interaction for PG‐1 with mammalian and bacterial membranes. Specifically, the equilibrium orientation of the peptide relative to SDS is a mirror image of its position relative to DPC. In both systems, the arginine residues of PG‐1 strongly interact with the head groups of the micelles. In DPC, the peptide prefers a location closer to the core of the micelle with Phe12, Val14, and Val16 imbedded in the core and the other side of the hairpin, which includes Leu5 and Tyr7, located closer to the surface of the micelle. In SDS, the peptide prefers a location at the micelle–water interface. The peptide position is reversed, with Leu5 and Cys6 imbedded furthest in the micelle core and Phe12, Val14, and Val16 on the surface of the micelle. We discuss the implications of these results with respect to activity and toxicity. © 2005 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 84: 219–231, 2006

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
[Ru(TAP)3]2+‐Photosensitized DNA Cleavage Studied by Atomic Force Microscopy and Gel Electrophoresis: A Comparative Study
Authors: Uji‐i Hiroshi , Foubert Philippe , De Schryver Frans C. , De Feyter Steven , Gicquel Etienne , Etoc Ariane , Moucheron Cécile , Kirsch‐De Mesmaeker Andrée
Published: October 2005

Topological modifications of plasmid DNA adsorbed on a variety of surfaces were investigated by using atomic force microscopy (AFM). On mica modified with 3‐aminopropyltriethoxysilane (APS) or poly‐L‐lysine, the interaction between the plasmid DNA and the surface “freezes” the plasmid DNA conformation deposited from solution, and the AFM images resemble the projection of the three‐dimensional conformation of the plasmid DNA in solution. Modified mica with low concentrations of Mg2+ leads to a decrease in the interaction strength between plasmid DNA and the substrate, and the AFM images reflect the relaxed or equilibrium conformation of the adsorbed plasmid DNA. Under these optimized deposition conditions, topological modifications of plasmid DNA were produced under irradiation in the presence of [Ru(TAP)3]2+ (TAP=1,4,5,8‐tetraazaphenanthrene), which is a non‐intercalating complex, and were followed as a function of illumination time. The observed structural changes correlate well with the conversion of the supercoiled covalently closed circular form (ccc form) into the open circular form (oc form), induced by a single‐strand photocleavage. The AFM results obtained after fine‐tuning of the plasmid DNA–substrate interaction compare well with those observed from gel electrophoresis, indicating that under the appropriate deposition conditions, AFM is a reliable technique to investigate irradiation‐induced topological changes in plasmid DNA.
New Hybrid Bidentate Ligands as Precursors for Smart Catalysts
Authors: Goettmann Frédéric , Boissière Cédric , Grosso David , Mercier François , Le Floch Pascal , Sanchez Clément
Published: October 2005

1‐Phosphanorbornadiene derivatives were grafted onto various periodically organized mesoporous powders, including a new zirconia/silica mixed oxide synthesized by aerosol techniques. After complexation with the [Rh(CO)2]+ fragment, these materials were revealed to be more active in olefin hydrogenation than their homogeneous counterparts. The reasons for this higher activity are discussed in the light of theoretical modeling. Various surface treatments, such as esterification, drying, and functionalization with PhSi(OEt)3, provided insights into the nature and mechanism of formation of the active species. Zirconia‐based materials were found to be active in internal olefin hydroformylation. Investigation of the mechanism of this reaction shows that the isomerization step is catalyzed by the Lewis acidic support, whereas the hydroformylation step is driven by the rhodium catalyst. Dissociation of these two steps leads to enhancement of activity.
Host–Guest Interactions in the Supramolecular Incorporation of Fullerenes into Tailored Holes on Porphyrin‐Modified Gold Nanoparticles in Molecular Photovoltaics
Authors: Imahori Hiroshi , Fujimoto Atsushi , Kang Soonchul , Hotta Hiroki , Yoshida Kaname , Umeyama Tomokazu , Matano Yoshihiro , Isoda Seiji , Isosomppi Marja , Tkachenko Nikolai V. , Lemmetyinen Helge
Published: October 2005

Novel gold nanoparticles modified with a mixed self‐assembled monolayer of porphyrin alkanethiol and short‐chain alkanethiol were prepared (first step) to examine the size and shape effects of surface holes (host) on porphyrin‐modified gold nanoparticles. The porphyrin‐modified gold nanoparticles with a size of about 10 nm incorporated C60 molecules (guest) into the large, bucket‐shaped holes, leading to the formation of a supramolecular complex of porphyrin–C60 composites (second step). Large composite clusters with a size of 200–400 nm were grown from the supramolecular complex of porphyrin–C60 composites in mixed solvents (third step) and deposited electrophoretically onto nanostructured SnO2 electrodes (fourth step). Differences in the porphyrin:C60 ratio were found to affect the structures and photoelectrochemical properties of the composite clusters in mixed solvents as well as on the SnO2 electrodes. The photoelectrochemical performance of a photoelectrochemical device consisting of SnO2 electrodes modified with the porphyrin–C60 composites was enhanced relative to a reference system with small, wedged‐shaped surface holes on the gold nanoparticle. Time‐resolved transient absorption spectroscopy with fluorescence lifetime measurements suggest the occurrence of ultrafast electron transfer from the porphyrin excited singlet states to C60 or the formation of a partial charge‐transfer state in the composite clusters of supramolecular complexes formed between porphyrin and C60 leading to efficient photocurrent generation in the system. Elucidation of the relationship between host–guest interactions and photoelectrochemical function in the present system will provide valuable information on the design of molecular devices and machines including molecular photovoltaics.
Molecular Beam Rotational Spectrum of Cyclobutanone–Trifluoromethane: Nature of Weak CH⋅⋅⋅OC and CH⋅⋅⋅F Hydrogen Bonds
Authors: Ottaviani Paolo , Caminati Walther , Favero L. B. , Blanco Susana , López Juan C. , Alonso José L.
Published: October 2005

The molecular beam Fourier transform microwave spectrum of cyclobutanone–trifluoromethane has been assigned and measured. The carbon atom of trifluoromethane lies in the plane of the heavy atoms of cyclobutanone. The complex is stabilized by one C‐H⋅⋅⋅OC and two C‐H⋅⋅⋅F‐C weak hydrogen bonds. The C‐H⋅⋅⋅OC interaction, involving one carbonylic oxygen, is studied for the first time in detail with rotationally resolved spectroscopy. The two C‐H⋅⋅⋅F‐C weak hydrogen bonds involve two fluorine atoms of trifluoromethane and two hydrogens of the same methylenic group in the α position.
Multiple Component Approaches to C‐Glycosyl β‐Amino Acids by Complementary One‐Pot Mannich‐Type and Reformatsky‐Type Reactions
Authors: Dondoni Alessandro , Massi Alessandro , Sabbatini Simona
Published: October 2005

The development of new methods for the preparation of C‐glycosyl β‐amino acid libraries with chemical and stereochemical diversity levels was investigated and the results are described herein. Two complementary one‐pot three‐component Mannich‐type and Reformatsky‐type synthetic strategies have been developed for the construction of chiral 3‐amino propanoate fragments (eventually bis‐substituted at C‐2) directly linked to the anomeric carbon of pyranose and furanose residues. Both methods involved as the initial step the coupling of a sugar aldehyde to p‐methoxybenzylamine but differed in the nucleophile (a d2 synthon equivalent) which was successively added: a ketene silyl acetal (Mannich route) or a bromozinc enolate (Reformatsky route). Individual C‐glycosyl β‐amino esters were isolated as single 3R diastereoisomers in fair to excellent yield (60–90 %) and their structure assigned by NMR spectroscopy (Riguera protocol) supported by X‐ray crystallography. A tentative explanation of the observed stereochemical outcome based on transition‐state models is provided. A preliminary study on the synthesis of α,α‐difluoro C‐glycosyl β‐amino acids via a more traditional Reformatsky route is also reported.
Ring‐Opening Polymerization of Lactide with Group 3 Metal Complexes Supported by Dianionic Alkoxy‐Amino‐Bisphenolate Ligands: Combining High Activity, Productivity, and Selectivity
Authors: Amgoune Abderramane , Thomas Christophe M. , Roisnel Thierry , Carpentier Jean‐François
Published: October 2005

A series of new alkoxy‐amino‐bis(phenols) (H2L 1–6) has been synthesized by Mannich condensations of substituted phenols, formaldehyde, and amino ethers or diamines. The coordination properties of these dianionic ligands towards yttrium, lanthanum, and neodymium have been studied. The resulting Group 3 metal complexes have been used as initiators for the ring‐opening polymerization of rac‐lactide to provide poly(lactic acid)s (PLAs). The polymerizations are living, as evidenced by the narrow polydispersities of the isolated polymers, together with the linear natures of number average molecular weight versus conversion plots and monomer‐to‐catalyst ratios. Complex [Y(L6){N(SiHMe2)2}(THF)] (17) polymerized rac‐lactide to heterotactic PLA (Pr = 0.90 at 20 °C) and meso‐lactide to syndiotactic PLA (Pr = 0.75 at 20 °C). The in situ formation of [Y(L6)(OiPr)(THF)] (18) from 17 and 2‐propanol resulted in narrower molecular weight distributions (PDI = 1.06). With complex 18, highly heterotactic PLAs with narrow molecular weight distributions were obtained with high activities and productivities at room temperature. The natures of the ligand substituents were shown to have a significant influence on the degree of control of the polymerizations, and in particular on the tacticity of the polymer.
Input–output organization of jaw movement‐related areas in monkey frontal cortex
Authors: Hatanaka Nobuhiko , Tokuno Hironobu , Nambu Atsushi , Inoue Tomio , Takada Masahiko
Published: October 2005

The brain mechanisms underlying mastication are not fully understood. To address this issue, we analyzed the distribution patterns of cortico–striatal and cortico–brainstem axon terminals and the origin of thalamocortical and intracortical fibers by injecting anterograde/retrograde tracers into physiologically and morphologically defined jaw movement‐related cortical areas. Four areas were identified in the macaque monkey: the primary and supplementary orofacial motor areas (MIoro and SMAoro) and the principal and deep parts of the cortical masticatory area (CMaAp and CMaAd), where intracortical microstimulation produced single twitch‐like or rhythmic jaw movements, respectively. Tracer injections into these areas labeled terminals in the ipsilateral putamen in a topographic fashion (MIoro vs. SMAoro and CMaAp vs. CMaAd), in the lateral reticular formation and trigeminal sensory nuclei contralaterally (MIoro and CMaAp) or bilaterally (SMAoro) in a complex manner of segregation vs. overlap, and in the medial parabranchial and Kölliker‐Fuse nuclei contralaterally (CMaAd). The MIoro and CMaAp received thalamic projections from the ventrolateral and ventroposterolateral nuclei, the SMAoro from the ventroanterior and ventrolateral nuclei, and the CMaAd from the ventroposteromedial nucleus. The MIoro, SMAoro, CMaAp, and CMaAd received intracortical projections from the ventral premotor cortex and primary somatosensory cortex, the ventral premotor cortex and rostral cingulate motor area, the ventral premotor cortex and area 7b, and various sensory areas. In addition, the MIoro and CMaAp received projections from the three other jaw movement‐related areas. Our results suggest that the four jaw movement‐related cortical areas may play important roles in the formation of distinctive masticatory patterns. J. Comp. Neurol. 492:401–425, 2005. © 2005 Wiley‐Liss, Inc.
Overlapping intracellular and differential synaptic distributions of dopamine D1 and glutamate N‐methyl‐D‐aspartate receptors in rat nucleus accumbens
Authors: Hara Yuko , Pickel Virginia M.
Published: October 2005

The dopamine D1 receptor (D1R) in the nucleus accumbens (Acb) shell is highly implicated in psychostimulant‐evoked locomotor activity and reward, whereas the D1R in the Acb core is more crucial for appetitive instrumental learning. These behavioral effects depend in part on interactions involving glutamatergic N‐methyl‐D‐aspartate (NMDA) receptors, whose essential NR1 subunit has physical associations with the D1R. To determine the relevant sites for D1R activation and interactions involving NMDA receptors, we examined the electron microscopic immunolabeling of D1R and NR1 C‐terminal peptides in rat Acb shell and core. In each Acb subdivision, the D1Rs were located principally on extrasynaptic plasma membranes of dendritic shafts and spines and more rarely were associated with cytoplasmic endomembranes. Many D1R‐labeled somata and dendrites also contained NR1 immunoreactivity. In comparison with D1R, NR1 immunoreactivity was more often seen in the cytoplasm and near asymmetric synapses on somatodendritic profiles. In these profiles, notable overlapping distributions of D1R and NR1 occurred near endomembranes. The exclusively D1R‐ or D1R‐ and NR1‐containing dendrites were most prevalent in the Acb shell, but were also present in the Acb core. In each region, NR1 was also detected in axon terminals without D1R, which formed excitatory‐type synapses with D1R‐labeled dendrites. These results provide ultrastructural evidence that D1Rs in the Acb have subcellular distributions supporting, 1) intracellular cotrafficking with NR1 and 2) modulation of the postsynaptic excitability in spiny neurons affected by presynaptic NMDA receptor activation. The region‐specific differences in receptor distributions suggest a major, but not exclusive, involvement of Acb D1R in reward‐related processing. J. Comp. Neurol. 492:442–455, 2005. © 2005 Wiley‐Liss, Inc.
Light microscopic identification and immunocytochemical characterization of glutamatergic synapses in brain sections
Authors: Melone Marcello , Burette Alain , Weinberg Richard J.
Published: October 2005

Presynaptic proteins are readily identified by light microscopic immunocytochemistry, but immunodetection of postsynaptic proteins in brain sections proves difficult. We performed immunofluorescent double labeling for the NR1 subunit of theN‐methyl‐D‐aspartate receptor (NMDAR) and the vesicular glutamate transporter 1 (VGLUT1). In material fixed with 4% paraformaldehyde, NMDAR staining in somatosensory cortex was restricted to the section surface, whereas presynaptic staining extended deeper into the tissue. Staining for postsynaptic proteins was enhanced in weakly fixed material and in tissue treated with pepsin, as previously reported, but tissue quality was impaired. Staining was also markedly enhanced, and without impairment of tissue quality, by treatment during perfusion with a mixture of inhibitors of proteases and the ubiquitin/proteosome system. We performed quantitative analysis of confocal images to study how immunostaining varies with depth into the tissue. Virtually all puncta immunopositive for VGLUT1 colocalized with synaptophysin puncta; these presynaptic puncta were most numerous 1–2 μm beneath the section surface. In contrast, puncta immunopositive for the NR1 subunit were most numerous at the surface, as were puncta immunopositive for the NR2 subunit, SynGAP, and CaMKII. Punctate staining for all postsynaptic proteins, but not presynaptic markers, was substantially enhanced in material pretreated with antiproteolytic agents. The large majority of NR1‐positive puncta at the surface associated with VGLUT1 in this material are likely to represent synaptic contacts. Approximately eighty‐five percent of VGLUT1‐positive puncta in layers II–III of SI are associated with NR1‐positive puncta, and ∼80% are associated with NR2, SynGAP, and CaMKII. This approach may permit systematic analysis of the chemistry of glutamatergic synapses with light microscopic immunocytochemistry. J. Comp. Neurol. 492:495–509, 2005. © 2005 Wiley‐Liss, Inc.
The PDAPP mouse model of Alzheimer's disease: Locus coeruleus neuronal shrinkage
Authors: German Dwight C. , Nelson Omar , Liang Fen , Liang Chang‐Lin , Games Dora
Published: October 2005

Alzheimer's disease is characterized by neuronal degeneration in the cerebral cortex and hippocampus and subcortical neuronal degeneration in such nuclei as the locus coeruleus (LC). Transgenic mice overexpressing mutant human amyloid precursor protein V717F, PDAPP mice, develop several Alzheimer's disease‐like lesions. The present study sought to determine whether there is also loss of LC noradrenergic neurons or evidence of degenerative changes in these animals. PDAPP hemizygous and wild‐type littermate control mice were examined at 23 months of age, at a time when there are numerous amyloid‐β (Aβ) plaques in the neocortex and hippocampus. Tissue sections were stained immunohistochemically with an antibody against tyrosine hydroxylase (TH) to identify LC neurons. Computer imaging procedures were used to count the TH‐immunoreactive somata in sections through the rostral‐caudal extent of the nucleus. There was no loss of LC neurons in the hemizygous mice. In a second experiment, homozygous PDAPP and wild‐type mice were examined, at 2 months and 24 months of age. Again there was no age‐related loss of neurons in the homozygous animals. In the portion of the LC where neurons reside that project to the cortex and hippocampus, however, the neurons were decreased in size selectively in the 24‐month‐old transgenic animals. These data indicate that overt LC cell loss does not occur following abundant overexpression of Aβ peptide. However, the selective size reduction of the LC neuronal population projecting to cortical and hippocampal regions containing Aβ‐related neuropathology implies that these cells may be subjected to a retrograde‐mediated stress. J. Comp. Neurol. 492:469–476, 2005. © 2005 Wiley‐Liss, Inc.
Cellular phenotype of androgen receptor‐immunoreactive nuclei in the developing and adult rat brain
Authors: Lorenz Betty , Garcia‐Segura Luis Miguel , DonCarlos Lydia L.
Published: October 2005

Androgen exposure during development and adulthood promotes cell‐to‐cell communication, modulates the size of specific brain nuclei, and influences hormone‐dependent behavioral and neuroendocrine functions. Androgen action involves the activation of androgen receptors (AR). To elucidate the mechanisms involved in AR‐mediated effects on forebrain development, double‐label fluorescent immunohistochemistry and confocal microscopy were employed to identify the cellular phenotype of AR‐immunoreactive (AR+) cells in the developing (embryonic day 20, postnatal days 0, 4, 10) and adult male rat forebrain. Sections were doubly labeled with antibodies directed against AR and one of the following: neurons (immature, nestin; mature, NeuN) or astrocytes [immature, vimentin; mature, glial fibrillary acidic protein (GFAP)] or mature oligodendrocytes (mGalC). In all brain regions examined, by far the majority of AR+ cells were neurons. In addition, small subsets of AR+ cells were identified as mature astrocytes (GFAP+) but only in specific brain regions at specific ages. AR+/GFAP+ cells were observed in the cerebral cortex but only in postnatal day 10 rats and in the arcuate nucleus of the hypothalamus but only in adult rats. Immature neurons, immature astrocytes, and oligodendrocytes were not AR+ at any age, in any region. Thus, both neurons and astrocytes in the male rat forebrain contain ARs, suggesting that androgens, via ARs, may exert effects on both cell types in an age‐ and region‐dependent manner. J. Comp. Neurol. 492:456–468, 2005. © 2005 Wiley‐Liss, Inc.
Application of the second derivative of the Kubelka–Munk function to the semiquantitative analysis of Roman paintings
Authors: Rodríguez José María Fernández , Fernández José Antonio Fernández
Published: October 2005

In the present survey, we have analyzed Roman paintings in two rooms in a villa at El Ruedo (Almedinilla, Córdoba, Spain). We used different techniques and procedures, such as X‐ray diffraction and diffuse reflectance. We established parameters that define colours in every international system. The diffuse reflectance techniques allowed us to identify the pigments, emphasizing that their mixtures are usually based upon a single chromatic pigment. © 2005 Wiley Periodicals, Inc. Col Res Appl, 30, 448–456, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.
Channel adjustments of the lower Trinity River, Texas, downstream of Livingston Dam
Authors: Phillips Jonathan D. , Slattery Michael C. , Musselman Zachary A.
Published: October 2005

Channel cross‐sectional changes since construction of Livingston Dam and Lake Livingston in 1968 were studied in the lower Trinity River, Texas, to test theoretical models of channel adjustment, and to determine controls on the spatial extent of channel response. High and average flows were not significantly modified by the dam, but sediment transport is greatly reduced. The study is treated as an opportunistic experiment to examine the effects of a reduction in sediment supply when discharge regime is unchanged. Channel scour is evident for about 60 km downstream, and the general phenomena of incision, widening, coarsening of channel sediment and a decrease in channel slope are successfully predicted, in a qualitative sense, by standard models of channel response. However, there is no consistent channel response within this reach, as various qualitatively different combinations of increases, decreases or no change in width, depth, slope and roughness occur. These multiple modes of adjustment are predicted by the unstable hydraulic geometry model. Between about 60 km and the Trinity delta 175 km downstream of the dam, no morphological response to the dam is observed. Rather than a diminution of the dam's effects on fluvial processes, this is due to a fundamental change in controls of the fluvial system. The downstream end of the scour zone corresponds to the upstream extent of channel response to Holocene sea level rise. Beyond 60 km downstream, the Trinity River is characterized by extensive sediment storage and reduced conveyance capacity, so that even after dam construction sediment supply still exceeds transport capacity. The channel bed of much of this reach is near or below sea level, so that sea level rise and backwater effects from the estuary are more important controls on the fluvial system than upstream inputs. Copyright © 2005 John Wiley & Sons, Ltd.
Discharge and suspended sediment dynamics during two jökulhlaups in the Skaftá river, Iceland
Authors: Old Gareth H. , Lawler Damian M. , Snorrason Árni
Published: October 2005

This paper investigates the dynamics and significance of discharge and suspended sediment transport (SST) during two jökulhlaups (glacier outburst floods) in the Skaftá River, south Iceland. Jökulhlaups occur frequently in many glacial environments and are highly significant in the geomorphological evolution of river basins and coastal environments. However, direct high‐resolution monitoring of jökulhlaups has rarely been accomplished and hardly ever at more than one station in a downstream sequence. Here we present detailed data on jökulhlaup discharge and water quality from an intensive monitoring and sampling programme at two sites in summer 1997 when two jökulhlaups occurred. Evidence is discussed that supports the origin of both jökulhlaups being subglacial reservoirs, produced over several months by subglacial geothermal activity. At the downstream site, Ása‐Eldvatn, the larger jökulhlaup (1) had a peak discharge of 572 m3 s−1 and a peak suspended sediment flux of 4650 kg s−1 (channel‐edge value) or 4530 kg s−1 (cross‐sectional). These values compare to the non‐jökulhlaup flow of 120 m3 s−1 and suspended sediment flux of 190 kg s−1 (channel‐edge) or 301 kg s−1 (cross‐sectional). Significantly, the jökulhlaups transported 18·8 per cent of the annual runoff and 53 per cent of the annual suspended sediment transport in 6·6 per cent of the year. Furthermore, water chemistry, suspended sediment and seismic data suggest that volcanic activity and geothermal boiling (possibly including steam explosions) may have occurred during Jökulhlaup 1. The research illustrates the value of integrating high‐resolution, multi‐point field monitoring of meteorological, hydrological, hydrochemical, geomorphological and seismological data for understanding the dynamics, significance and downstream translation of jökulhlaups. Copyright © 2005 John Wiley & Sons, Ltd.
A key for Aspidistra (Ruscaceae), including fifteen new species from Vietnam
Authors: Tillich H.‐J.
Published: October 2005

Fifteen species and two subspecies of Aspidistra (Ruscaceae, Monocotyledons) from Vietnam new to science are described. This raises the number of known species to 76 and extends the genus area to South Vietnam at ca. 12° N. Additionally, a detailed new key is given to determine all recently known species in Aspidistra.

New species: Aspidistra atroviolaca, A. bicolor, A. bogneri, A. carnosa, A. connata, A. foliosa, A. geastrum, A. lateralis, A. lutea, A. marasmioides, A. opaca, A. petiolata, A. stricta, A. subrotata, A. superba .

New subspecies: Aspidistra arnautovii sp. nova, subsp. arnautovii, A. arnautovii subsp. nova catbaensis, A. subrotata subsp. nova crassinervis .

New combinations: Aspidistra dodecandra, A. glandulosa . (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Plant regeneration mechanisms during early post‐fire succession in south‐eastern Spain
Authors: Buhk C. , Sánchez Gómez P. , Hensen I.
Published: October 2005

Regeneration mechanisms during vegetation succession were quantified on different post‐fire sites (2–3 y after fire) in south‐eastern Spain (Province of Murcia). We distinguished between (a) species regenerating exclusively sexually (obligate seeders), (b) species regenerating to 30–70% sexually (facultative sprouters) and (c) species regenerating mainly vegetatively after fire (sprouters). The importance of the mechanisms at the different fire sites were compared between the different locations (mountains vs. coast) and exposure (north vs. south‐facing) on the one hand and with undisturbed reference sites on the other hand. While patterns of regeneration mechanisms between the recently burnt plots were very similar to the undisturbed reference sites, the quantity of mechanisms between the coastal and the mountainous areas and between northern and southern aspects differed considerably. Facultative sprouters were more abundant close to the coast than in the mountains, while mainly sprouting species covered the largest areas in north‐facing mountainous sites. According to microclimatic data, an altered water balance may be responsible for major differences in regeneration mechanisms between mountainous and coastal sites and contrasting aspects. In conformity with the data available to us, the vegetation of the Murcia region is highly resilient to fire as vegetation returns quickly to a state similar as before the fire. The high differences in the success of regeneration mechanisms between the different exposures, however, indicate a strong sensibility of vegetation toward local climatic differences. We therefore expect that climate change could have a remarkable effect on the vegetation composition. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The numerical solution of the laminar flow in a constricted channel at moderately high Reynolds number using Newton iteration
Authors: Hunt Roland
Published: October 2005

The numerical solution of the flow in a stepped channel constricted to half its width has been obtained for Reynolds numbers up to 2000 using Newton's iteration to solve the ensuing algebraic system. In order to avoid high‐frequency errors, a locally fine grid is effected near the corner by transformation of the independent variables. The results predict a downstream recirculation region, observed in experiments but not found in earlier numerical calculations. The inclusion of the Dennis–Hudson upwinding, added for stability in SOR methods, whilst giving the same characteristics of the flow, is less accurate by at least an order of magnitude.
Computing axisymmetric, laminar internal flows
Authors: Derksen R. W.
Published: October 2005

A simple computational scheme is developed to compute laminar flows inside axisymmetric ducts. It is based on the Keller box method where the equations are approximated at the centre of the downstream face of each computational box. The coupling between the pressure gradient and the velocities for internal flow has been observed to introduce stability problems for the Keller box method that are not present for external, boundary layer flow problems. The difference scheme for the velocities is coupled to an iterative scheme to solve for the pressure gradient at each axial step. Example results for developing flow in a pipe and in a 2° conical diffuser are presented.
Numerical solution of the steady incompressible Navier—Stokes equations for the flow past a sphere by a multigrid defect correction technique
Authors: Juncu Gh. , Mihail R.
Published: October 2005

A nested non‐linear multigrid algorithm is developed to solve the Navier–Stokes equations which describe the steady incompressible flow past a sphere. The vorticity–streamfunction formulation of the Navier–Stokes equations is chosen. The continuous operators are discretized by an upwind finite difference scheme. Several algorithms are tested as smoothing steps. The multigrid method itself provides only a first‐order‐accurate solution. To obtain at least second‐order accuracy, a defect correction iteration is used as outer iteration. Results are reported for Re = 50, 100, 400 and 1000.
Computational experiments on interactions between numerical and physical instabilities
Authors: Choquin J. P. , Huberson S.
Published: October 2005

Three numerical examples of singular flows in two and three dimensions computed with the vortex method are presented. The effect of the cut‐off parameter is investigated and special techniques are added to the classical vortex method to diminish the numerical instabilities present in the examples.
Infinite elements for water wave radiation and scattering
Authors: Chen H. S.
Published: October 2005

The infinite element method is employed to approximate the solutions of Webster's horn equation and Berkhoff's equation for water wave radiation and scattering in an unbounded domain. Functionals based on the first variational principle are presented. Two new infinite elements, which exactly satisfy the one‐ and two‐dimensional Sommerfeld radiation condition, are presented; the simple shape functions are constructed on the basis of the asymptotic behaviour of the scattered wave at infinity. All the integrals in the functionals involving each infinite element are integrated analytically and, as a result, no numerical integration is required. The programming requirements and computational efficiency are essentially no different than those of the conventional finite element method. For the test cases presented, the numerical results are acceptably accurate when compared with the existing solutions and laboratory data.
Finite element formulation for transport equations in a mixed co‐ordinate system: An application to determine temperature effects on the single‐well chemical tracer test
Authors: Park Y. J. , Deans H. A. , Tezduyar T. E.
Published: October 2005

Heterogeneous equation systems in a pair of coupled co‐ordinate systems are solved by a finite element method. The specific physical application studied is the effect of temperature on single‐well chemical tracer (SWCT) tests to measure residual oil saturation (volume fraction of immobile oil phase) remaining after waterflooding of an oil reservoir. Since temperature effects are caused by injecting cooler surface fluid down a well into a warm reservoir, the vertical temperature profile in the wellbore as well as the temperature distribution in the porous oil‐bearing layer must be considered.

The entire system is modelled to account for the different transport mechanisms. However, it is expedient to divide the connected geometrical region into two model domains. The equations for each submodel are expressed in an appropriate set of co‐ordinates. The variational formulation of each model is then discussed.

A significant temperature effect on the estimation of residual oil saturation occurs when the radial temperature and concentration wave propagation speeds in the porous formation are about the same. In this case the temperature gradient is located across the chemical tracer bank, causing the chemical reaction rate to vary radially. The temperature effects are demonstrated for two actual field tests in complex reservoirs.
Finite element analysis of axisymmetric free jet impingement
Authors: Mejak George
Published: October 2005

A numerical algorithm to determine the impingement of an axisymmetric free jet upon a curved deflector is presented. The problem is considered within the potential flow theory with the allowance of gravity and surface tension effects. The primary dependent variable is the Stokes streamfunction, which is approximated through finite elements using the isoparametric Hermite Zienkiewicz element. To find the correct position of the free boundaries, a trial‐and‐error method is employed which amounts to solving a boundary value problem (BVP) for the Stokes streamfunction at each iteration step. An efficient method is proposed to solve this BVP. The algorithm to find the correct position of the free boundaries is tested by computing the impingement upon an infinite disc and a hemispherical deflector. To confirm the correctness of the solution, each problem has been solved using several different mesh gradings. A comparison between the Zienkiewicz and the other standard C0 finite elements is also given.
Multigrid flow solutions in complex two‐dimensional geometries
Authors: Rayner D.
Published: October 2005

A finite difference solution algorithm is described for use on two‐dimensional curvilinear meshes generated by the solution of the transformed Laplace equation. The efficiency of the algorithm is improved through the use of a full approximation scheme (FAS) multigrid algorithm using an extended pressure correction scheme as smoother. The multigrid algorithm is implemented as a fixed V‐cycle through the grid levels with a constant number of sweeps being performed at each grid level.

The accuracy and efficiency of the numerical code are validated using comparisons of the flow over two backward step configurations. Results show close agreement with previous numerical predictions and experimental data. Using a standard Cartesian co‐ordinate flow solver, the multigrid efficiency obtainable in a rectangular system is shown to be reproducible in two‐dimensional body‐fitted curvilinear co‐ordinates. Comparisons with a standard one‐grid method show the multigrid method, on curvilinear meshes, to give reductions in CPU time of up to 93%.