bluuebunny/crossref_metadata_2025 huggingface dataset:
Goldfish Calmodulin: Molecular Cloning, Tissue Distribution, and Regulation of Transcript Expression in Goldfish Pituitary Cells
Authors: Huo Longfei , Lee Eric K. Y. , Leung P. C. , Wong Anderson O. L.
Published: August 2004

Calmodulin (CaM) is a Ca2+-binding protein essential for biological functions mediated through Ca2+-dependent mechanisms. In the goldfish, CaM is involved in the signaling events mediating pituitary hormone secretion induced by hypothalamic factors. However, the structural identity of goldfish CaM has not been established, and the neuroendocrine mechanisms regulating CaM gene expression at the pituitary level are still unknown. Here we cloned the goldfish CaM and tested the hypothesis that pituitary expression of CaM transcripts can be the target of modulation by hypothalamic factors. Three goldfish CaM cDNAs, namely CaM-a, CaM-bS, and CaM-bL, were isolated by library screening. These cDNAs carry a 450-bp open reading frame encoding the same 149-amino acid CaM protein, the amino acid sequence of which is identical with that of mammals, birds, and amphibians and is highly homologous (≥90%) to that in invertebrates. In goldfish pituitary cells, activation of cAMP- or PKC-dependent pathways increased CaM mRNA levels, whereas the opposite was true for induction of Ca2+ entry. Basal levels of CaM mRNA was accentuated by GnRH and pituitary adenylate cyclase-activating polypeptide but suppressed by dopaminergic stimulation. Pharmacological studies using D1 and D2 analogs revealed that dopaminergic inhibition of CaM mRNA expression was mediated through pituitary D2 receptors. At the pituitary level, D2 activation was also effective in blocking GnRH- and pituitary adenylate cyclase-activating polypeptide-stimulated CaM mRNA expression. As a whole, the present study has confirmed that the molecular structure of CaM is highly conserved, and its mRNA expression at the pituitary level can be regulated by interactions among hypothalamic factors.
Graves’ Hyperthyroidism and the Hygiene Hypothesis in a Mouse Model
Authors: Nagayama Yuji , McLachlan Sandra M. , Rapoport Basil , Oishi Kazunori
Published: August 2004

Graves’ hyperthyroidism is an organ-specific autoimmune disease mediated by stimulatory autoantibodies against the TSH receptor (TSHR; thyroid-stimulating antibodies), causing thyroid hyperplasia and hyperthyroidism. Development of this ailment is well known to be under polygenic and environmental control. For example, we recently demonstrated that parasite helminth Schistosoma mansoni infection suppressed a T helper cell type 1 (Th1)-type anti-TSHR immune response and prevented disease development in our mouse model of Graves’ disease using adenovirus coding for the TSHR. In the present study we examined the outcome of infection with Mycobacterium bovis bacillus Calmette-Guérin (BCG), a Th1-promoting infectious pathogen, on Graves’ disease. Our results show that prior infection with M. bovis BCG differentiates the TSHR-specific immune response toward a Th1 phenotype, as demonstrated by enhanced secretion of a Th1 cytokine interferon-γ and impaired production of a Th2 cytokine IL-10 from splenocytes stimulated in vitro with TSHR antigen. M. bovis BCG also significantly suppressed disease induction. These data together with our recent report that coinjection of adenovirus expressing the Th1 cytokine IL-12 induced a Th1-polarized, TSHR-specific immune response without affecting disease development support the hygiene hypothesis, rather than Th1-mediated disease suppression. Thus, some infectious pathogens may influence the development of Graves’ disease regardless of their ability to modify the Th1/Th2 balance.
Adrenergic Regulation and Diurnal Rhythm of p38 Mitogen-Activated Protein Kinase Phosphorylation in the Rat Pineal Gland
Authors: Chik C. L. , Mackova M. , Price D. , Ho A. K.
Published: August 2004

In this study, we investigated adrenergic and photoneural regulation of p38MAPK phosphorylation in the rat pineal gland. Norepinephrine (NE), the endogenous neurotransmitter, dose-dependently increased the levels of phosphorylated MAPK kinase 3/6 (MKK3/6) and p38MAPK in rat pinealocytes. Time-course studies showed a gradual increase in MKK3/6 and p38MAPK phosphorylation that peaked between 1 and 2 h and persisted for 4 h post NE stimulation. In cells treated with NE for 2 and 4 h, the inclusion of prazosin or propranolol reduced NE-induced MKK3/6 and p38MAPK phosphorylation, indicating involvement of both α- and β-adrenergic receptors for the sustained response. Whereas treatment with dibutyryl cAMP or ionomycin mimicked the NE-induced MKK3/6 and p38MAPK phosphorylation, neither dibutyryl cGMP nor 4β-phorbol 12-myristate 13-acetate had an effect. The NE-induced increase in MKK3/6 and p38MAPK phosphorylation was blocked by KT5720 (a protein kinase A inhibitor) and KN93 (a Ca2+/calmodulin-dependent kinase inhibitor), but not by KT5823 (a protein kinase G inhibitor) or calphostin C (a protein kinase C inhibitor). In animals housed under a lighting regimen with 12 h of light, MKK3/6 and p38MAPK phosphorylation increased in the rat pineal gland at zeitgeber time 18. The nocturnal increase in p38MAPK phosphorylation was blocked by exposing the animal to constant light and reduced by treatment with propranolol, a β-adrenergic blocker. Together, our results indicate that activation of p38MAPK is under photoneural control in the rat pineal gland and that protein kinase A and intracellular Ca2+ signaling pathways are involved in NE regulation of p38MAPK.
Thyroid Hormone Treatment of Hypothyroid Rats Restores the Regenerative Capacity and the Mitochondrial Membrane Permeability Properties of the Liver after Partial Hepatectomy
Authors: Moro Loredana , Marra Ersilia , Capuano Ferdinando , Greco Margherita
Published: August 2004

We have investigated the effect of thyroid hormone on recovery of liver mass and on the mitochondrial membrane permeability properties during rat liver regeneration after 70% partial hepatectomy (PH). In the euthyroid state, liver weight starts to recover 24 h after PH and is completely restored 96 h after PH. Cyclosporin A (CsA)-sensitive mitochondrial permeability transition (MPT) occurs 24 h after PH, and it has been suggested to act in the signaling mechanism for hepatocyte proliferation. In this study we show that hypothyroidism delays recovery of the liver mass, being only 50% of the initial weight 96 h after PH, and alters the duration and mode of MPT occurrence, first inducing a CsA-insensitive swelling 24 h after PH, followed by a CsA-sensitive swelling 96 h after PH. The occurrence of both CsA-sensitive and -insensitive swelling is shown to be associated with an increase in mitochondrial calcium content. Concurrent with mitochondrial swelling, external release of matrix proteins from mitochondria, such as aspartate aminotransferase and malate dehydrogenase, is shown to be CsA insensitive 24 h after PH and CsA sensitive 96 h after PH. After thyroid hormone administration to hypothyroid rats, the liver regenerative capacity is restored, and the duration and mode of MPT occurrence as well as changes in mitochondrial calcium content become similar to those observed in the euthyroid condition. The results of the present study suggest the involvement of a mitochondria-mediated pathway in regulation of the liver regenerative process by thyroid hormone.
Glia Mediates the Neuroprotective Action of Estradiol on β-Amyloid-Induced Neuronal Death
Authors: Sortino M. A. , Chisari M. , Merlo S. , Vancheri C. , Caruso M. , Nicoletti F. , Canonico P. L. , Copani A.
Published: August 2004

17β-Estradiol (17β-E2) is known to exert neuroprotective activity against β-amyloid, but its exact target and mechanism of action in this effect have not been elucidated. The involvement of astroglia in neuroprotection of 17β-E2 against the β-amyloid fragment [βAP(25–35)] has been evaluated using an experimental paradigm in which medium conditioned from rat astroglia pretreated with 17β-E2 was transferred to pure rat cortical neurons challenged with 25 μm βAP(25–35) for 24 h. The toxicity of βAP(25–35) was assessed by flow cytometry, evaluating the ability of the peptide to induce an aberrant mitotic cell cycle in neurons. The results obtained indicate that conditioned medium from astrocytes preexposed to 17β-E2 for 4 h increased the viability of cortical neurons treated with βAP(25–35). This effect was not modified by treatment with the estrogen receptor antagonist ICI 182,780, added directly to neurons, nor was it mimicked by direct addition of 17β-E2 to neuronal cultures during exposure to βAP(25–35). A soluble factor stimulated by 17β-E2 seemed to be involved, and accordingly, the intracellular and released levels of TGF-β1 were increased by 17β-E2 treatment, as established by Western blot analysis. In addition, the intracellular content of TGF-β1 in immunopositive cells, as detected by flow cytometry, was reduced, suggesting that 17β-E2 stimulated mainly the release of the cytokine. In support of a role for TGF-β1 in astrocyte-mediated 17β-E2 neuroprotective activity, incubation with a neutralizing anti-TGF-β1 antibody significantly modified the reduction of neuronal death induced by 17β-E2-treated astrocyte-conditioned medium.
Mitogenic Activity of Estrogens in Human Breast Cancer Cells Does Not Rely on Direct Induction of Mitogen-Activated Protein Kinase/Extracellularly Regulated Kinase or Phosphatidylinositol 3-Kinase
Authors: Gaben Anne-Marie , Saucier Cécile , Bedin Monique , Redeuilh Gérard , Mester Jan
Published: August 2004

We have addressed the question of rapid, nongenomic mechanisms that may be involved in the mitogenic action of estrogens in hormone-dependent breast cancer cells. In quiescent, estrogen-deprived MCF-7 cells, estradiol did not induce a rapid activation of either the MAPK/ERK or phosphatidylinositol-3 kinase (PI-3K)/Akt pathway, whereas the entry into the cell cycle was documented by the successive inductions of cyclin D1 expression, hyperphosphorylation of the retinoblastoma protein (Rb), activity of the promoter of the cyclin A gene, and DNA synthesis. However, pharmacological inhibitors of the src family kinases, 4-amino-5-(4-methylphenyl)-7-(t-butyl) pyrazolo[3,4-d] pyrimidine (PP1) or of the PI-3K (LY294002) did prevent the entry of the cells into the cell cycle and inhibited the late G1 phase progression, whereas the inhibitor of MAPK/ERK activation (U0126) had only a partial inhibitory effect in the early G1 phase. In agreement with these results, small interfering RNA targeting Akt strongly inhibited the estradiolinduced cell cycle progression monitored by the activation of the promoter of the cyclin A gene. The expression of small interfering RNA targeting MAPK 1 and 2 also had a clear inhibitory effect on the estradiol-induced activation of the cyclin A promoter and also antagonized the estradiol-induced transcription directed by the estrogen response element. Finally, transfection of the estrogen receptor into NIH3T3 fibroblasts did not confer to the cells sensitivity to a mitogenic action of estradiol. We conclude that the induction of the cell cycle by estradiol does not require a direct activation of MAPK/ERK or PI-3K signaling protein kinase cascades, but that these kinases appear to have a permissive role in the cell cycle progression.
A Novel Estrogen Receptor α-Associated Protein Alters Receptor-Deoxyribonucleic Acid Interactions and Represses Receptor-Mediated Transcription
Authors: Loven Margaret A. , Davis Roger E. , Curtis Carol D. , Muster Nemone , Yates John R. , Nardulli Ann M.
Published: August 2004

Estrogen receptor α (ERα) serves as a ligand-activated transcription factor, turning on transcription of estrogen-responsive genes in target cells. Numerous regulatory proteins interact with the receptor to influence ERα-mediated transactivation. In this study, we have identified pp32, which interacts with the DNA binding domain of ERα when the receptor is free, but not when it is bound to an estrogen response element. Coimmunoprecipitation experiments demonstrate that endogenously expressed pp32 and ERα from MCF-7 breast cancer cells interact. Although pp32 substantially enhances the association of the receptor with estrogen response element-containing DNA, overexpression of pp32 in MCF-7 cells decreases transcription of an estrogen-responsive reporter plasmid. pp32 Represses p300-mediated acetylation of ERα and histones in vitro and inhibits acetylation of ERα in vivo. pp32 Also binds to other nuclear receptors and inhibits thyroid hormone receptor β-mediated transcription. Taken together, our studies provide evidence that pp32 plays a role in regulating transcription of estrogen-responsive genes by modulating acetylation of histones and ERα and also influences transcription of other hormone-responsive genes as well.
Structural and functional adaptation to hypoxia in the rat brain
Authors: LaManna Joseph C. , Chavez Juan Carlos , Pichiule Paola
Published: August 2004

Chronic exposure to a hypoxic environment leads to structural and functional adaptations in the rat brain. One significant adaptation is a decrease in intercapillary distances through a near doubling of the capillary density, which begins after about 1 week of hypoxic exposure and is completed by 3 weeks. Hypoxic angiogenesis is controlled by activation of downstream genes by Hypoxia Inducible Factor-1 and Angiopoietin-2. The processes that increase capillary density are reversible upon restoration of the ambient oxygen concentration. Capillary regression, which also occurs over a 3-week period, is accomplished through activation of apoptosis. The implication from these observations is that the brain naturally functions in a low, but controlled, oxygen environment. Acute imbalances in oxygen delivery and metabolic demand are addressed through changes in blood flow; persistent imbalances activate mechanisms that adjust capillary density. The mechanisms that control these processes decline with age.
Clinical perspectives: neuroprotection lessons from hypoxia-tolerant organisms
Authors: Bickler Philip E.
Published: August 2004

An effective treatment for brain ischemia is a pressing medical need. Research on brain ischemia has largely focused on understanding the mechanisms of neuron death as a way of identifying targets for therapy. An attractive alternative approach is to identify the survival strategies of hypoxia-tolerant neurons. The adaptation of vertebrate neurons to hypoxia occurs in at least three major ways: (1) as a constitutive property of neurons in anoxia-tolerant turtles and fish, (2) as a property of intra-uterine and early post-natal mammalian development, and (3) as part of a slower, chronic process, as in acclimitization to high altitude. Research on hypoxia-tolerant neurons has already revised several earlier concepts, including the role of calcium in cell death and survival, and the value of N-methyl-d-aspartate (NMDA) receptor antagonism. A broad and fundamental understanding of how neurons adapt to hypoxia is likely to help guide efforts to find new treatments for brain hypoxia and ischemia.
Erythropoietin and the hypoxic brain
Authors: Marti Hugo H.
Published: August 2004

Normal tissue function in mammals depends on adequate supply of oxygen through blood vessels. A discrepancy between oxygen supply and consumption(hypoxia) induces a variety of specific adaptation mechanisms at the cellular,local and systemic level. These mechanisms are in part governed by the activation of hypoxia-inducible transcription factors (HIF-1, HIF-2), which in turn modulate expression of hypoxically regulated genes such as those encoding vascular endothelial growth factor (VEGF) and erythropoietin(EPO).

EPO is a glycoprotein that is produced mainly by interstitial fibroblasts in the kidneys of the adult and in hepatocytes in the foetus. Released into the circulation, EPO makes its way to the bone marrow, where it regulates red cell production by preventing apoptosis of erythroid progenitor cells. Recently, EPO has emerged as a multifunctional growth factor that plays a significant role in the nervous system. Both EPO and its receptor are expressed throughout the brain in glial cells, neurones and endothelial cells. Hypoxia and ischaemia have been recognised as important driving forces of EPO expression in the brain. EPO has potent neuroprotective properties in vivo and in vitro and appears to act in a dual way by directly protecting neurones from ischaemic damage and by stimulating endothelial cells and thus supporting the angiogenic effect of VEGF in the nervous system. Thus,hypoxia-induced gene products such as VEGF and EPO might be part of a self-regulated physiological protection mechanism to prevent neuronal injury,especially under conditions of chronically reduced blood flow (chronic ischaemia).

In this review, I will briefly summarize the recent findings on the molecular mechanisms of hypoxia-regulated EPO expression in general and give an overview of its expression in the central nervous system, its action as a growth factor with non-haematopoietic functions and its potential clinical relevance in various brain pathologies.
Cellular oxygen sensing need in CNS function: physiological and pathological implications
Authors: Acker Till , Acker Helmut
Published: August 2004

Structural and functional integrity of brain function profoundly depends on a regular oxygen and glucose supply. Any disturbance of this supply becomes life threatening and may result in severe loss of brain function. In particular, reductions in oxygen availability (hypoxia) caused by systemic or local blood circulation irregularities cannot be tolerated for longer periods due to an insufficient energy supply to the brain by anaerobic glycolysis. Hypoxia has been implicated in central nervous system pathology in a number of disorders including stroke, head trauma, neoplasia and neurodegenerative disease. Complex cellular oxygen sensing systems have evolved for tight regulation of oxygen homeostasis in the brain. In response to variations in oxygen partial pressure (PO2) these induce adaptive mechanisms to avoid or at least minimize brain damage.

A significant advance in our understanding of the hypoxia response stems from the discovery of the hypoxia inducible factors (HIF), which act as key regulators of hypoxia-induced gene expression. Depending on the duration and severity of the oxygen deprivation, cellular oxygen-sensor responses activate a variety of short- and long-term energy saving and cellular protection mechanisms. Hypoxic adaptation encompasses an immediate depolarization block by changing potassium, sodium and chloride ion fluxes across the cellular membrane, a general inhibition of protein synthesis, and HIF-mediated upregulation of gene expression of enzymes or growth factors inducing angiogenesis, anaerobic glycolysis, cell survival or neural stem cell growth. However, sustained and prolonged activation of the HIF pathway may lead to a transition from neuroprotective to cell death responses. This is reflected by the dual features of the HIF system that include both anti- and proapoptotic components.

These various responses might be based on a range of oxygen-sensing signal cascades, including an isoform of the neutrophil NADPH oxidase, different electron carrier units of the mitochondrial chain such as a specialized mitochondrial, low PO2 affinity cytochrome c oxidase (aa3) and a subfamily of 2-oxoglutarate dependent dioxygenases termed HIF prolyl-hydroxylase (PHD) and HIF asparaginyl hydroxylase, known as factor-inhibiting HIF (FIH-1). Thus specific oxygen-sensing cascades, by means of their different oxygen sensitivities,cell-specific and subcellular localization, may help to tailor various adaptive responses according to differences in tissue oxygen availability.
Hypoxia tolerance in mammalian heterotherms
Authors: Drew K. L. , Harris M. B. , LaManna J. C. , Smith M. A. , Zhu X. W. , Ma Y. L.
Published: August 2004

Heterothermic mammals tolerate severe hypoxia, as well as a variety of central nervous system insults, better than homeothermic mammals. Tolerance to hypoxia may stem from adaptations associated with the ability to survive hibernation and periodic arousal thermogenesis. Here, we review evidence and mechanisms of hypoxia tolerance during hibernation, euthermy and arousal in heterothermic mammals and consider potential mechanisms for regenerative-like processes, such as synaptogenesis, observed within hours of hypoxic stress associated with arousal thermogenesis.
Preparation, Characterization, and Reactivities of Highly Functional Titanium Oxide-Based Photocatalysts Able to Operate under UV–Visible Light Irradiation: Approaches in Realizing High Efficiency in the Use of Visible Light
Authors: Anpo Masakazu
Published: August 2004

A review of the research advances made in the design and development of highly reactive and functional titanium oxide photocatalysts, which can utilize not only UV but also visible or solar light, and a clarification of the active sites as well as the detection of the reaction intermediates at the molecular level have been presented here. The potential for the effective utilization and conversion of solar energy into useful and safe chemical energy by the modification of the electronic properties of such TiO2 photocatalysts is great when one considers their myriad applications as well as their non-polluting qualities. Such a modification process by methods such as ion-implantation can be applied not only for semiconducting bulk TiO2 photocatalysts but also for TiO2 thin film photocatalysts and titanium oxide photocatalysts highly dispersed within zeolite frameworks. Moreover, the photocatalytic reactivity of semiconducting TiO2 nano-powders was found to be dramatically enhanced by the loading of small amounts of Pt. This worked to enhance the reduction reaction, resulting in the charge separation of the electrons and holes generated by light irradiation. In addition, highly dispersed titanium oxide species prepared within zeolite frameworks as well as SiO2 or Al2O3 matrices showed much higher and unique photocatalytic performances as compared to semiconducting bulk TiO2 photocatalysts. Significantly, a new alternative method to directly prepare such visible light-responsive TiO2 thin film photocatalysts on various substrates has been successfully developed by applying a RF magnetron sputtering deposition method.
Thermodynamics and Kinetics of Formation of Intramolecular Naphthalene Dimer Radical Cation Studied by Near-IR Transient Absorption Spectroscopy
Authors: Fushimi Toshiki , Fujita Yusuke , Ohkita Hideo , Ito Shinzaburo
Published: August 2004

Thermodynamics and kinetics for formation of an intramolecular dimer radical cation of a series of α,ω-di(2-naphthyl)alkanes in solutions were quantitatively investigated by near-IR transient absorption spectroscopy, which allows one to observe dimer radical cations directly. The standard enthalpy (−ΔH°) for the formation of the intramolecular dimer radical cation increased as the chain length between the two naphthyl moieties increased, and was smaller than that of the intermolecular dimer radical cation of 2-ethylnaphthalene. This shows that −ΔH° depends on the strain required for the chain to form the ring-closure configuration. Destabilization due to repulsion between the two naphthyl moieties in the intramolecular dimer radical cation was evaluated to be ca. 20 kJ mol−1. This value is smaller than that of the naphthalene excimer, indicating that the separation distance and/or the overlap between the two naphthyl moieties are not as restricted as those of the excimer. The activation energy for the formation of the intramolecular dimer radical cation was comparable to the energy for local motions of a few methylene units linking the two naphthalene moieties.
An Investigation of Weak Ion Association Equilibria between Inorganic Anions and Tetraalkylammonium Ions in Ethanol–Aqueous Media Using Capillary Zone Electrophoresis
Authors: Mbuna Julius , Takayanagi Toshio , Oshima Mitsuko , Motomizu Shoji
Published: August 2004

Weak ion association equilibria between inorganic anions, ranging in charge from −1 to −4, and symmetrical tetraalkylammonium ions, R4N+ (R = Me, Et, Pr, Bu, n-Am), were investigated in formate buffer solutions containing a variable composition of ethanol (0–62.9% (m/m)). The individual effective mobilities of the inorganic anions in a series of tetraalkylammonium chloride solutions were measured using an ordinary silica capillary maintained at 25.0 ± 0.1 °C under a negative potential (−10 kV) and direct UV detection (λ = 220 nm). Under the stated experimental conditions, the association constants, Kass, showed a modest increase as the amount of ethanol in the buffer was increased. The concepts of medium effect and Gibbs free energy of transfer were applied to weak ion equilibria in order to investigate changes in association constant as the ethanol content in the buffer solutions was increased. The above treatment on selected associations revealed that the increased instability of the inorganic anion in mixed ethanolic solutions is responsible for the observed increase in Kass.
The Magnetic Susceptibilities and Electron Paramagnetic Resonance Spectra of 6H-Perovskites Ba3PrM2O9 (M = Ir, Ru)
Authors: Hinatsu Yukio , Oyama Shigeaki , Doi Yoshihiro
Published: August 2004

The magnetic properties of quaternary oxides Ba3PrM2O9 and Ba3CeM2O9 (M = Ir, Ru) have been investigated. They crystallize in the 6H-perovskite structure with the space group P63/mmc, in which the cation sites with the face-sharing octahedra are occupied by Ir (or Ru) ions, and those within the corner-sharing octahedra are occupied by Pr (or Ce) ions. Magnetic susceptibility measurements for Ba3PrIr2O9 show that an antiferromagnetic interaction between two Ir ions in the Ir2O9 dimer results in a large temperature-independent paramagnetic susceptibility over a wide temperature range. Another interesting result is in the small effective magnetic moments for Ba3PrIr2O9 (0.31(1) μB) and for Ba3PrRu2O9 (0.75(1) μB). The electron paramagnetic resonance (EPR) spectrum of Pr4+ in these compounds was measured by diluting them in the corresponding isomorphous compounds Ba3CeIr2O9 and Ba3CeRu2O9 and lowering the temperature to 4.2 K. A very large hyperfine interaction with the 141Pr nucleus was observed. The results were analyzed based on the weak field approximation. The measured g values are much smaller than |−10/7|, showing that the crystal field effect on the behavior of a 4f electron is large. The low g values correspond to the small effective magnetic moments of the Pr compounds.
Di(9-anthryl)carbene Revisited. Product Analysis and Spectroscopic Studies
Authors: Yoshida Ken-ichi , Iiba Eiji , Nozaki Yoshinori , Hirai Katsuyuki , Takahashi Yasutake , Tomioka Hideo , Lin Cheng-Tung , Gaspar Peter P
Published: August 2004

Irradiation (λ > 300 nm) of di(9-anthryl)diazomethane (1) in degassed benzene gave the trimer (3) of dianthrylcarbene (2) as the main product along with a small amount of a tetramer (4). The structures of those oligomers were characterized as caged compounds produced as a result of three- and four-fold coupling at the 10 and 10′ positions of 2. Photolysis of 1 in the presence of oxygen with short wavelength UV light resulted in the formation of di(9-anthryl) ketone (5) and anthraquinone (6), while similar irradiation with a longer wavelength light gave 5 and 9-anthryl 9-anthracenecarboxylate (9), which was found to give 6 upon irradiation with a short wavelength light in the presence of oxygen. On the other hand, the photolysis of 4 gave 3 as the main product, while 3 was almost completely photostable under similar conditions. However, irradiation of both 3 and 4 in the presence of oxygen gave 6. In order to elucidate the reactions observed, we carried out spectroscopic studies (matrix EPR and UV/vis spectroscopies as well as laser flash photolysis) with 1, 3, and 4. These studies revealed that 3 generated a trimer diradical (10) formed as a result of C–C bond cleavage upon irradiation and that 10 reformed 3 almost exclusively, while similar photolysis of 1 and 4 generated the same two transient species, 10 and a dimer diradical. It is proposed that triplet carbene 2 equilibrates with the dimer diradical 2-2 and that the main decay pathway of this mixture is to generate the trimer diradical 10 while dimer diradical 2-2 undergoes coupling to produce the tetramer 4. The structure of the triplet carbene in equilibrium with diradicals is also discussed.
Precise Structure Control of Enzymatically Synthesized Polyphenols
Authors: Mita Naruyoshi , Tawaki Shin-ichiro , Uyama Hiroshi , Kobayashi Shiro
Published: August 2004

The structural control and biodegradability of enzymatically synthesized polyphenols have been investigated. The peroxidase-catalyzed oxidative polymerization of various 4-substituted phenols was performed in aqueous organic solvents, in which the ratio of phenylene and oxyphenylene units of the polymer product could be precisely controlled by the nature of the solvents and the monomers. The unit ratio strongly depended on their hydrophobic parameters. The control of the structure was also examined by changing the feed ratio of the enzymatic copolymerization of the phenol derivatives. The biodegradability was evaluated by the BOD method. Poly(4-t-butylphenol) showed relatively good biodegradability, whereas little degradation of the polyphenol from unsubstituted phenol was observed.
Photochromism of Phenylazopyridines and Its Application to the Fluorescence Modulation of Zinc–Porphyrins
Authors: Otsuki Joe , Narutaki Koichi
Published: August 2004

Several 2- and 3-(phenylazo)pyridine derivatives were prepared. Most of their trans isomers have a large absorption band (∼2 × 104 M−1 cm−1 (1 M = 1 mol dm−3)) around 320 nm and a small absorption band (∼400 M−1 cm−1) around 450 nm. All of these compounds photoisomerize upon irradiation of the shorter (trans-to-cis) and longer (cis-to-trans) wavelength absorption bands. trans Isomers of 3-(phenylazo)pyridines axially coordinate more strongly to Zn–porphyrins than cis isomers, while the opposite is the case for 2-(phenylazo)pyridines, due to steric reasons. These phenylazopyridines quench the fluorescence of Zn–porphyrin upon coordination. These properties were exploited for the light-triggered fluorescence modulation of Zn–porphyrins. Light was irradiated to a mixed solution of phenylazopyridine and Zn–porphyrin to induce photoisomerization of the phenylazopyridine, which underwent association with, or dissociation from, the Zn–porphyrin, resulting in a decrease or increase of Zn–porphyrin fluorescence. For example, the fluorescence intensity of Zn–tetraphenylporphyrin reversibly changed by up to 50%, when 4-methoxy-2-(phenylazo)pyridine was employed.
Generation of Carbon Free Radicals by Reduction of the Cation Pool
Authors: Suga Seiji , Suzuki Shinkiti , Maruyama Tomokazu , Yoshida Jun-ichi
Published: August 2004

The electrochemical reduction of N-acyliminium ions, which were generated by the “cation pool” method, led to the formation of carbon free radicals. Carbon radicals thus generated underwent homo-coupling reactions and the reactions with activated olefins, such as methyl acrylate. In the latter case, a mechanism involving the addition of a carbon radical to the carbon–carbon double bond, followed by one-electron reduction to give carbanions, has been proposed. The present study opens a new possibility for radical-mediated carbon–carbon bond formation based on the reduction of carbocations.
Production Planning Under Yield and Demand Uncertainty with Yield-Dependent Cost and Price
Authors: Kazaz Burak
Published: August 2004

This paper studies production planning with random yield and demand. It is a departure from previous studies of random yield in that it defines the sale price and the purchasing cost as exogenous and increasing with decreasing yield. While this behavior can be observed in various industries (e.g., citrus), the paper focuses on the olive oil industry as its application. Production of olive oil is a challenging business as olives grow every other year; thus, a risky investment is involved. A new practice among olive oil producers involves leasing farm space from farmers to grow olives. When the yield of olives is low (because of weather, disease, etc.), the oil producer gets a second chance to buy olives from other farmers at a unit cost varying with the yield. In this case, the sale price of olive oil increases in the market place because of the reduced supply. When the yield is high, the company uses some of its olives for olive oil production and some are salvaged. After olives are pressed and olive oil is produced, the company experiences an uncertain demand. The paper makes four contributions: First, it is shown that the objective function is concave in the amount of farm space leased, so that the first-order conditions provide the globally optimal solution. Second, it illustrates how the total production of olive oil changes with the yield. Third, it proves that the optimal amount of farm space leased decreases under the presence of a second (and reliable) source of supply. Finally, unlike traditional yield papers, the fourth result shows that increased yield variance does not necessarily increase the optimal amount of farm space to be leased when there is a second chance to obtain supplies.
Controlling the Risk for an Agricultural Harvest
Authors: Allen Stuart J. , Schuster Edmund W.
Published: August 2004

Gathering the harvest represents a complex managerial problem for agricultural cooperatives involved in harvesting and processing operations: balancing the risk of overinvestment with the risk of underproduction. The rate to harvest crops and the corresponding capital investment are critical strategic decisions in situations where poor weather conditions present a risk of crop loss. In this article, we discuss a case study of the Concord grape harvest and develop a mathematical model to control harvest risk. The model involves differentiation of a joint probability distribution that represents risks associated with the length of the harvest season and the size of the crop. This approach is becoming popular as a means of dealing with complex problems involving operational and supply chain risk. Significant cost avoidance, in the millions of dollars, results from practical implementation of the Harvest Model. Using real data, we found that the Harvest Model provides lower-cost solutions in situations involving moderate variability in both the length of season and the crop size as compared to solutions based on imposed risk policies determined by management.
Efficiency Analysis of Agricultural Market Advisory Services: A Nonlinear Mixed-Integer Programming Approach
Authors: Cabrini Silvina M. , Stark Brian G. , Önal Hayri , Irwin Scott H. , Good Darrel L. , Martines-Filho João
Published: August 2004

Professional market advisory services provide specific advice (advisory programs) to grain producers on how to market their commodities, and assist them in their efforts to manage price risk. Previous studies analyzed the effectiveness of individual services and could find only weak evidence that these services help farmers improve their returns beyond market prices. The present study applies portfolio theory to determine an efficient combination of advisory programs using a nonlinear integer programming framework. The optimization results provide some evidence that an efficient portfolio provides significantly greater risk and return benefits compared to individual programs and external benchmarks. In a holdout period analysis, efficient portfolios have superior average return performance, but they fail to dominate the relevant benchmarks in terms of mean and variance. However, these out-of-sample results should be considered cautiously, given the small number of observations available.
Development of Attenuated Total Reflection Based Compression Modulation Step-Scan Fourier Transform Infrared Spectroscopy and its Applications to Rheo-Spectral Characterizations of Polymer Films
Authors: Nishikawa Yuji , Nakano Tatsuhiko , Miyauchi Hiroshi , Nishikida Koichi , Jiang Eric Y.
Published: August 2004

Dynamic compression modulation attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopic methods have been developed in this paper for characterizing polymer films. To obtain dynamic compression polarized ATR spectra, internal reflection element (IRE) secure assemblies made of tungsten carbide with very high hardness (Knoop hardness of >1000 kgf/mm2) have been designed. These assemblies are mounted on the Harrick Seagull® ATR attachment and measured by step-scan FT-IR spectroscopy. The effect of static compression, air gaps, and refractive index changes were examined. Experimental and simulated results showed that the effect of air gaps between the sample and IRE and refractive index changes of the sample and IRE are negligible at values larger than a static torque of 40 cN m and good signal-to-noise ratios (SNR) and reproducible data can be obtained. Uniaxially and biaxially drawn poly(ethylene terephthalate) films were measured by the presented method. Both bipolar and unipolar bands were observed in the dynamic in-phase ATR spectra, which can be associated with their micro-structural environmental changes. This technique shows promise in evaluating various polymer film materials, including biaxially oriented films, multilayer coated film surfaces, and molecular interactions between polymer–polymer and polymer–additives at the film surface.
Potential of Far-Ultraviolet Absorption Spectroscopy as a Highly Sensitive Quantitative and Qualitative Analysis Method for Aqueous Solutions, Part I: Determination of Hydrogen Chloride in Aqueous Solutions
Authors: Higashi Noboru , Ozaki Yukihiro
Published: August 2004

This paper reports the usefulness of far-ultraviolet (FUV) absorption spectroscopy in highly sensitive quantitative and qualitative analysis of aqueous solutions. We propose a totally new idea for the utilization of FUV spectroscopy in pure water and aqueous solution analyses. We use an absorption band near 170 nm due to an n → σ* transition of water. The intensity of the foot of this band, which can be observed in the 190–210 nm region by use of an ordinary ultraviolet–visible (UV-Vis) spectrometer, is very sensitive to changes in hydration and hydrogen bonds of water. To demonstrate the potential of FUV spectroscopy in analytical chemistry, we undertook three kinds of experiments. The first one is concerned with the discrimination of eight kinds of commercial natural mineral water. The eight kinds of mineral water can be discriminated straightforwardly from the spectral patterns in the 190–250 nm region without any spectral pretreatment or spectral analysis such as multivariate analysis. The second experiment is the determination of hydrogen chloride (HCl) in aqueous solutions. FUV spectra of aqueous solutions of HCl over a concentration of 0–20 ppm were measured. A calibration model for predicting the concentration of HCl in the aqueous solutions was developed based on the absorbance at 193 nm. This method does not require any spectral pretreatment or multivariate analysis. The correlation coefficient and standard error of prediction of the calibration model developed are 0.9987 and 0.18 ppm, respectively. The detection limit of the proposal method for the determination of HCl in aqueous solutions was estimated to be 0.5 ppm (13.7 μM). The determination of HCl was also tried for natural mineral water to which HCl solutions with the concentrations of 2, 4, 6, 8, 12, 16, and 20 ppm were artificially added. The third study was the determination of ammonia (NH3) and hydrogen peroxide (H2O2) in aqueous solutions containing both NH3 and H2O2. It has been found that the present method is also useful for the determination of the two-component system.
Characterization of Infrared and Near-Infrared Absorptions of Free Alcoholic OH Groups in Hydrocarbon
Authors: Iwamoto Reikichi , Matsuda Toshihiko
Published: August 2004

We have demonstrated that the near-infrared and infrared absorptions in the 8000–3200 cm−1 region of an OH group of 2-nonanol, 1-nonanol, etc., in n-heptane are excellently separated by subtraction without any serious interference down to very low concentrations at which OH groups are completely free. The separated sharp absorptions are assigned to the fundamental, combination, and overtone bands that are concerned with the OH stretching of free OH. Two components of a sharp overtone band around 7100 cm−1, which are observed for primary and secondary alcohols, are assigned to coexisting internal rotational isomers of an OH group around the O–C bond. The frequencies of the OH stretching fundamental and overtone bands that are assigned to internal rotational positions are consistent for all the investigated alcohols, including methanol and tertiary butanol. Comparison of the separated spectrum of 2-nonanol in n-heptane with that in 1-chlorooctane or in carbon tetrachloride makes it clear that hydrocarbon is an inert solvent that does not disturb the intrinsic nature of an alcohol OH group. There actually exists a constant anharmonicity shift of 169–175 cm−1 between the double frequency (2 v(OH)o) of the observed fundamental and the observed overtone frequency ([2 v(OH)]o) for free OH of various alcohols in n-heptane.
Analysis of Water Ice and Water Ice/Soil Mixtures Using Laser-Induced Breakdown Spectroscopy: Application to Mars Polar Exploration
Authors: Arp Zane A. , Cremers David A. , Wiens Roger C. , Wayne David M. , Sallé Béatrice , Maurice Sylvestre
Published: August 2004

Recently, laser-induced breakdown spectroscopy (LIBS) has been developed for the elemental analysis of geological samples for application to space exploration. There is also interest in using the technique for the analysis of water ice and ice/dust mixtures located at the Mars polar regions. The application is a compact instrument for a lander or rover to the Martian poles to interrogate stratified layers of ice and dusts that contain a record of past geologic history, believed to date back several million years. Here we present results of a study of the use of LIBS for the analysis of water ice and ice/dust mixtures in situ and at short stand-off distances (<6.5 m) using experimental parameters appropriate for a compact instrument. Characteristics of LIBS spectra of water ice, ice/soil mixtures, element detection limits, and the ability to ablate through ice samples to monitor subsurface dust deposits are discussed.
Carbon Analysis for Inspecting Carbonation of Concrete Using a TEA CO2 Laser-Induced Plasma
Authors: Kagawa Kiichiro , Idris Nasrullah , Wada Munehide , Kurniawan Hendrik , Tsuyuki Kenichiro , Miura Satoru
Published: August 2004

It has been demonstrated that a spectrochemical analysis of carbon using the laser plasma method can be successfully applied to inspect the carbonation of concrete by detecting carbon produced in aged concrete by a chemical reaction of Ca(OH)2 with CO2 gas in environmental air, turning into CaCO3, which induces degradation of the quality of building concrete. A comparative study has been made using a TEA CO2 laser (500–1000 mJ) and a Q-switched Nd– YAG laser (50–200 mJ) to search for the optimum conditions for carbon analysis, proving the advantage of the TEA CO2 laser for this purpose. Also, it was clarified that laser irradiation with suitable defocusing conditions is a crucial point for obtaining high sensitivity in the detection of carbon. Practical experiments on the inspection of carbonation were carried out using both a concrete sample that had been intentionally carbonated by exposure to high concentrations of CO2 gas and a naturally carbonated concrete sample. As a result, good coincidence was observed between the laser method and the ordinary method, which uses the chemical indicator phenolphthalein, implying that this laser technique is applicable as an in situ quantitative method of inspection for carbonation of concrete.
Potential-Dependent Surface-Enhanced Raman Scattering from Adsorbed Thiocyanate for Characterizing Silver Surfaces with Improved Reproducibility
Authors: Oklejas Vanessa , Harris Joel M.
Published: August 2004

Surface-enhanced Raman scattering (SERS) spectroelectrochemistry is used to characterize electrochemically roughened and highly polished polycrystalline silver SERS-active substrates. Changes in the nitrile stretching vibrational mode of adsorbed thiocyanate are used as an in situ spectroscopic probe: the potential dependence of band position (Stark tuning), shape, and scattering intensity of this mode are measured in order to investigate differences between SERS-active sites found on smooth and roughened electrode surfaces. Results obtained from thiocyanate adsorbed onto two different types of highly polished Ag surfaces (alumina and diamond polishing) show discrete populations of SERS-active adsorption sites that remain stable over a wide potential range. This behavior stands in contrast to that observed on electrochemically roughened surfaces, where very strong Stark tuning, large vibrational bandwidths, and irreversible loss of SERS enhancement upon negative potential excursions can be attributed to a diverse population of labile SERS-active sites that exhibit strong charge-transfer interactions with the adsorbate and large chemical SERS enhancement.
Characterization of Novel Ag on TiO2 Films for Surface-Enhanced Raman Scattering
Authors: Mills A. , Hill G. , Stewart M. , Graham D. , Smith W. E. , Hodgen S. , Halfpenny P. J. , Faulds K. , Robertson P.
Published: August 2004

Novel Ag on TiO2 films are generated by semiconductor photocatalysis and characterized by ultraviolet–visible (UV/Vis) spectroscopy, scanning electron microscopy (SEM), and atomic force microscopy (AFM), as well as assessed for surface-enhanced Raman scattering (SERS) activity. The nature and thickness of the photo-deposited Ag, and thus the degree of SERS activity, is controlled by the time of exposure of the TiO2 film to UV light. All such films exhibit the optical characteristics (λmax ≅ 390 nm) of small (<20 nm) Ag particles, although this feature becomes less prominent as the film becomes thicker. The films comprise quite large (>40 nm) Ag islands that grow and merge with increasing levels of Ag photodeposition. Tested with a benzotriazole dye probe, the films are SERS active, exhibiting activity similar to that of 6-nm-thick vapor-deposited films. The Ag/TiO2 films exhibit a lower residual standard deviation (∼25%) compared with Ag vapor-deposited films (∼45%), which is, however, still unacceptable for quantitative work. The sample-to-sample variance could be reduced significantly (<7%) by spinning the film during the SERS measurement. The Ag/TiO2 films are mechanically robust and resistant to removal and damage by scratching, unlike the Ag vapor-deposited films. The Ag/TiO2 films also exhibit no obvious loss of SERS activity when stored in the dark under otherwise ambient conditions. The possible extension of this simple, effective method of producing Ag films for SERS, to metals other than Ag and to semiconductors other than TiO2, is briefly discussed.