bluuebunny/crossref_metadata_2025 huggingface dataset:
Uptake of dexamethasone incorporated into liposomes by macrophages and foam cells and its inhibitory effect on cellular cholesterol ester accumulation
Authors: Chono Sumio , Morimoto Kazuhiro
Published: August 2006

To confirm the efficacy of dexamethasone incorporated into liposomes in the treatment of atherosclerosis, the uptake of dexamethasone-liposomes by macrophages and foam cells and its inhibitory effect on cellular cholesterol ester accumulation in these cells were investigated in-vitro. Dexamethasone-liposomes were prepared with egg yolk phosphatidylcholine, cholesterol and dicetylphosphate in a lipid molar ratio of 7/2/1 by the hydration method. This was adjusted to three different particle sizes to clarify the influence of particle size on the uptake by the macrophages and foam cells, and the inhibitory effect on cellular cholesterol ester accumulation. The distribution of particle sizes of dexamethasone-liposomes were 518.7 ± 49.5nm (L500), 202.2± 23.1 nm (L200), and 68.6 ± 6.5 nm (L70), respectively. For each size, dexamethasone concentration and dexamethasone/lipid molar ratio in dexamethasone-liposome suspension were 1 mg dexamethasone mL−1 and 0.134 mol dexamethasone mol−1 total lipids, respectively. The zeta potential was approximately −70 mV for all sizes. Dexamethasone-liposomes or free dexamethasone were added to the macrophages in the presence of oxidized low density lipoprotein (oxLDL) and foam cells, and then incubated at 37°C. The uptake amount of dexamethasone by the macrophages and foam cells after a 24-h incubation was L500 > L200 > free dexamethasone > L70. The macrophages in the presence of oxLDL and foam cells were incubated with dexamethasone-liposomes or free dexamethasone for 24 h at 37°C to evaluate the inhibitory effect on the cellular cholesterol ester accumulation. The cellular cholesterol ester level in the macrophages treated with oxLDL was significantly increased compared with that in macrophages without additives. L500, L200 and free dexamethasone significantly inhibited this cholesterol ester accumulation. L500, L200 and free dexamethasone also significantly reduced cellular cholesterol ester accumulation in foam cells. In addition, the relationship between the area under the uptake amount of dexamethasone-time curve (AUC) and the inhibition rate of cholesterol ester accumulation in macrophages and foam cells was evaluated. The inhibition rate of cholesterol ester accumulation (%) was related to the AUC in both types of cell. These results suggested that dexamethasone-liposomes would be a useful approach to the development of a novel drug delivery system for atherosclerotic therapy. Furthermore, the prediction of the inhibitory effect of dexamethasone on cellular cholesterol ester accumulation may become possible by using the results of this study.
Enhanced therapeutic potential of naringenin-phospholipid complex in rats
Authors: Maiti Kuntal , Mukherjee Kakali , Gantait Arunava , Saha Bishnu Pada , Mukherjee Pulok K
Published: August 2006

Naringenin is a naturally occurring flavanone, possessing a variety of biological activity. Due to its rapid elimination, naringenin needs frequent administration to maintain an effective plasma concentration. We have evaluated the therapeutic potential of naringenin-phospholipid complex under oxidative stress conditions compared with free naringenin. Naringenin-phospholipid complex was prepared and assessed for antioxidant activity in carbon tetrachloride intoxicated rats at a dose level of 100 mg kg−1 (p.o.). Liver function tests were studied by assessing serum glutamate oxaloacetate transaminase, serum glutamate pyruvate transaminase, serum alkaline phosphatase and total bilirubin. Marker enzymes of liver, namely glutathione peroxidase, superoxide dismutase, catalase and thiobarbituric acid reactive substances, were measured to evaluate the antioxidant potential at the same dose level. The plasma concentration of naringenin was also measured. It was observed that the naringenin-phospholipid complex enhanced the antioxidant activity of the biomolecule and protected the liver significantly for a longer time as compared with free naringenin at the same dose level. Phospholipid complex of naringenin produced better antioxidant activity than the free compound with a prolonged duration of action, which may be helpful in reducing the fast elimination of the molecule from body.
Voltage-gated Na+ channel ligands and ATP: relative molecular similarity and implications for channel function
Authors: Williams W R
Published: August 2006

The voltage-gated sodium channel (VGNC) is targeted by naturally occurring ligands and drugs of diverse structure. ATP modulates VGNC current in-vitro but is given little prominence in models describing channel function. This computational study uses superimposition and molecular fitting to investigate relative molecular similarity within the structures of ATP and VGNC ligands. A motif of 3 linked atoms (C-N-C) in the adenine ring of ATP satisfies the fitting of a wide range of anticonvulsant structures. An alternative group (N-C-N) provides one fitting motif for the ester and amide groups of local anaesthetic drugs; protonated amine and aromatic groups in the same conformers fit to a second motif in the adenine ring. Analogous structures from other drug classes with VGNC blocking activity give the same molecular fits to ATP. Structures fitted to the adenine ring of ATP occlude the intra-molecular space between the nucleoside and triphosphate chain in approximation to their established blocking, activating or neutral effects on Na+ current. The findings are discussed in terms of drug preferences for VGNC states and channel requirements for ATP.
Indorenate modifies a1-adrenergic and benzodiazepine receptor binding in the rat brain: an autoradiography study
Authors: López-Meraz M L , Neri-Bazán L , Rocha L
Published: August 2006

Indorenate (5-methoxytryptamine-β-methylcarboxylate) is a 5-HT1A receptor agonist that produces antihypertensive, anxiolytic, antidepressant and anticonvulsant effects. However, there is evidence suggesting that these effects could involve the activation of benzodiazepine (BZD) receptors but not the activation of a1-adrenergic receptors. The goal of this study was to analyse the effect of indorenate on a1-adrenergic and BZD receptor binding in specific rat brain areas by using in-vitro autoradiography. Coronal brain sections from male Wistar rats were used for labelling 5-HT1A (3H-8-OH-DPAT, 2 nm), a1-adrenergic (3H-prazosin, 2 NM) and BZD (3H-flunitrazepam, 2 NM) receptor binding in the presence or absence of indorenate (1 μm). Indorenate totally displaced 3H-8-OH-DPAT binding in all the brain areas evaluated. It decreased 3H-prazosin binding just in the frontal (30%) and sensorimotor (32%) cortices and in the thalamus (21%). Additionally, indorenate diminished 3H-flunitrazepam binding only in the cingulate (10%) and piriform (18%) cortices as well as in the dorsal raphe nucleus (18%). These results confirm that indorenate is a 5-HT1A ligand and suggest the possible participation of a1-adrenergic and BZD receptors in its pharmacological properties.
Synthesis and pharmacological investigation of novel 1-substituted-4-(4-substituted phenyl)-4H-[1,2,4]triazolo[4,3-a]quinazolin-5-ones as a new class of H1-antihistamine agents
Authors: Alagarsamy V , Giridhar Rajani , Yadav M R
Published: August 2006

A series of novel 1-substituted-4-(4-substituted phenyl)-4H-[1,2,4]triazolo[4,3-a]quinazolin-5-ones was synthesized by the cyclization of 2-hydrazino-3-(4-substituted phenyl)-3H-quinazolin-4-one with various one-carbon donors. The starting material, 2-hydrazino-3-(4-substituted phenyl)-3H-quinazolin-4-one, was synthesized from 4-substituted aniline by a novel innovative route. When tested for in-vivo H1-antihistamine activity on conscious guinea-pigs, all the test compounds significantly protected the animals against histamine-induced bronchospasm. The compound 1-methyl-4-(4-chloro phenyl)-4H-[1,2,4]triazolo[4,3-a]quinazolin-5-one (VII) was more potent (72.71% protection), and 1-methyl-4-(4-methoxy phenyl)-4H-[1,2,4]triazolo[4,3-a]quinazolin-5-one (II) was equipotent (71% protection), when compared with the reference standard, chlorpheniramine maleate (71% protection). Compounds II and VII showed negligible sedation (5% and 8% respectively) when compared with chlorpheniramine maleate (25%). Compounds II and VII could serve as prototype molecules for further development as a new class of H1-antihistamines.
Role of four major components in the effect of Si-Ni-San, a traditional Chinese prescription, against contact sensitivity in mice
Authors: Zhang Li , Dong Yi , Sun Yang , Chen Ting , Xu Qiang
Published: August 2006

Previously, we demonstrated the inhibitory effects of Si-Ni-San, a traditional Chinese prescription, on picryl chloride-induced ear contact sensitivity (PCl-CS). This study aimed to evaluate the role of the four major constituents contained in the prescription (saikosaponins, paeoniflorin, naringin and glycyrrhizin) in the inhibitory effect. When administered during the induction phase, saikosaponin a and glycyrrhizin showed significant inhibitory effects, while paeoniflorin and naringin did not. These components in Si-Ni-San also inhibited the activation and proliferation of T lymphocytes as well as the production of cytokines such as tumour necrosis factor-α and interferon-γ to different extents. Saikosaponin a and paeoniflorin dose-dependently reduced the splenocyte adhesion to type I collagen, while glycyrrhizin only showed a slight tendency. Furthermore, treatment with glycyrrhizin or saikosaponin a, rather than paeoniflorin or naringin, moderately inhibited the matrix metalloproteinase (MMP)-2 activity of the splenocytes from PCl-CS mice, and the combination of all four components showed a strong inhibition against MMP-2. Moreover, the components markedly decreased the serum level of nitric oxide in PCl-sensitized mice. The results indicated that saikosaponin a and glycyrrhizin may be the major contributors in the alleviation effect of Si-Ni-San on contact sensitivity, and paeoniflorin and naringin may exhibit a co-operative effect.
Anti-inflammatory, analgesic and anti-oedematous effects of Lafoensia pacari extract and ellagic acid
Authors: Rogerio Alexandre P , Fontanari Caroline , Melo Mirian C C , Ambrosio Sérgio R , de Souza Glória E P , Pereira Paulo S , França Suzelei C , da Costa Fernando B , Albuquerque Deijanira A , Faccioli Lúcia H
Published: August 2006

Lafoensia pacari St. Hil. (Lythraceae) is used in traditional medicine to treat inflammation. Previously, we demonstrated the anti-inflammatory effect that the ethanolic extract of L. pacari has in Toxocara canis infection (a model of systemic eosinophilia). In this study, we tested the antiinflammatory activity of the same L. pacari extract in mice injected intraperitoneally with β-glucan present in fraction 1 (F1) of the Histoplasma capsulatum cell wall (a model of acute eosinophilic inflammation). We also determined the anti-oedematous, analgesic and anti-pyretic effects of L. pacari extract in carrageenan-induced paw oedema, acetic acid writhing and LPS-induced fever, respectively. L. pacari extract significantly inhibited leucocyte recruitment into the peritoneal cavity induced by β-glucan. In addition, the L. pacari extract presented significant analgesic, anti-oedematous and anti-pyretic effects. Bioassay-guided fractionation of the L. pacari extract in the F1 model led us to identify ellagic acid. As did the extract, ellagic acid presented anti-inflammatory, anti-oedematous and analgesic effects. However, ellagic acid had no anti-pyretic effect, suggesting that other compounds present in the plant stem are responsible for this effect. Nevertheless, our results demonstrate potential therapeutic effects of L. pacari extract and ellagic acid, providing new prospects for the development of drugs to treat pain, oedema and inflammation.
Compounds from rose (Rosa rugosa) flowers with human immunodeficiency virus type 1 reverse transcriptase inhibitory activity
Authors: Fu M , Ng T B , Jiang Y , Pi Z F , Liu Z K , Li L , Liu F
Published: August 2006

The aqueous extracts and ethanol precipitates of aqueous extracts of 18 medicinal herbs traditionally used in China were screened for their ability to inhibit human immunodeficiency virus type-1 reverse transcriptase (HIV-1 RT) in-vitro. Among the samples screened at a concentration of 500 μg mL−1, dried rose (Rosa rugosa) flowers showed the strongest inhibition. The ethanol precipitate of the aqueous extract of R. rugosa was processed and two components (P1 and P2) were obtained after ion exchange chromatography on DEAE-cellulose. Then, P1-a (Mr 150 kDa) and P1-b (Mr 8 kDa) were isolated from P1 by gel filtration on Sephadex G-200. They inhibited the activity of HIV-1 RT with an IC50 of 158 nm and 148.16 μg mL−1 (18.5 μm), respectively. Further structural analyses revealed that P1-a was a polysaccharide-peptide complex, and P1-b was a polymer consisting of acteoside and acteoside derivatives identified by Fourier transform infrared spectroscopy, nuclear magnetic resonance, assays of carbohydrate and protein contents and high-performance liquid chromatography electrospray ionization mass spectrometry.
Cytotoxic activity and cytostatic mechanism of novel 2-arylbenzo[b]furans
Authors: Yang Hua , Pang Ji-Yan , Cai Yu-Chen , Xu Zun-Le , Xian Li-Jian
Published: August 2006

The aims of this study were to screen cytotoxic compounds from 14 newly-synthesized 2-arylbenzo[b]furans and explore their mechanisms of action. Cytotoxicity was determined by the MTT method. Cell-cycle distribution was detected by flow cytometry. Wright-Giemsa staining was performed to demonstrate the morphological features of cells in mitotic phase. Polymerization of tubulin was detected by tubulin assembly assay, and the cellular microtubule network was observed by immunocytochemical study. Among the 14 compounds screened, 4-formyl-2-(4-hydroxy-3-methoxyphenyl)-5-(2-methoxycarbonyethyl)-7-methoxy-benzo[b]furan (ERJT-12) showed significant cytotoxicity. Our results demonstrated that ERJT-12 exhibited anti-cancer activity in a variety of tumour cell lines with an IC50 value (concentration resulting in 50% inhibition of cell growth) of 5.75∼17.29μM. Cell cycle analysis showed a concentration-dependent accumulation of tumour cells in G2/M phase after treatment with ERJT-12. Further investigation indicated that ERJT-12 blocked the cell cycle in M phase, with separation and dispersion of chromosomes. ERJT-12 inhibited tubulin polymerization in-vitro. Changes of the cellular microtubule network caused by ERJT-12 were also detected, which were similar to the changes caused by colchicine. These results suggested that the anti-cancer activity of ERJT-12 is worth further investigation.
Development and pharmacokinetics of nimodipine-loaded liposomes
Authors: Wang Zhixuan , Deng Yingjie , Zhang Xiaopeng , Wang Ting , Wu Fenglan
Published: August 2006

In order to improve the water solubility of nimodipine and prolong the time of the drug in the circulation, nimodipine-loaded liposomes with a small size and high entrapment efficiency were prepared by a method that was easy to scale up (the modified ethanol injection method). The nimodipine liposome dispersions were characterized with respect to particle size distribution, zeta potential and entrapment efficiency. Liposomal nimodipine and nimodipine solution were intravenously administered to mice as a single dose of 4 mg kg−1. The pharmacokinetic parameters of nimodipine changed significantly when encapsulated in liposomes. The clearance of nimodipine encapsulated in liposomes was reduced and the elimination half-life was prolonged. The ratios of the area under the curve values of nimodipine liposomes to nimodipine solution were 1.78 and 1.90 in plasma and cerebral tissue, respectively. The drug concentration in cerebral tissue and in plasma showed a good linear correlation, which showed that liposomes could efficiently deliver nimodipine into brain tissue. These findings suggest that intravenous administration of liposomal nimodipine produces higher and more stable plasma and cerebral drug concentrations compared with nimodipine solution. In conclusion, liposomal nimodipine is a promising alternative to the solution preparation.
Distinct roles of the Pumilio and FBF translational repressors duringC. elegansvulval development
Authors: Walser Claudia B. , Battu Gopal , Hoier Erika Fröhli , Hajnal Alex
Published: August 2006

The C. elegans PUF and FBF proteins regulate various aspects of germline development by selectively binding to the 3′ untranslated region of their target mRNAs and repressing translation. Here, we show that puf-8, fbf-1 and fbf-2 also act in the soma where they negatively regulate vulvaI development. Loss-of-function mutations in puf-8 cause ectopic vulval differentiation when combined with mutations in negative regulators of the EGFR/RAS/MAPK pathway and suppress the vulvaless phenotype caused by mutations that reduce EGFR/RAS/MAPK signalling. PUF-8 acts cell-autonomously in the vulval cells to limit their temporal competence to respond to the extrinsic patterning signals. fbf-1 and fbf-2, however, redundantly inhibit primary vulval cell fate specification in two distinct pathways acting in the soma and in the germline. The FBFs thereby ensure that the inductive signal selects only one vulval precursor cell for the primary cell fate. Thus, translational repressors regulate various aspects of vulval cell fate specification, and they may play a conserved role in modulating signal transduction during animal development.
A garden of Notch-ly delights
Authors: Weinmaster Gerry , Kopan Raphael
Published: August 2006

Over the past decade, the Notch signaling pathway has been shown to be crucially important for normal metazoan development and to be associated with several human inherited and late onset diseases. The realization that altered Notch signaling contributes at various levels to human disease lead in May to the first meeting dedicated solely to Notch signaling in vertebrate development and disease in Madrid, Spain. Hosted by the Cantoblanco Workshops on Biology and organized by Tom Gridley, José Luis de la Pompa and Juan Carlos Izpisúa Belmonte, the meeting covered diverse aspects of this important signaling pathway.
An oligodendrocyte-specific zinc-finger transcription regulator cooperates with Olig2 to promote oligodendrocyte differentiation
Authors: Wang Shu-Zong , Dulin Jennifer , Wu Heng , Hurlock Edward , Lee Sang-Eun , Jansson Kyle , Lu Q. Richard
Published: August 2006

Molecular mechanisms that control oligodendrocyte myelination during mammalian central nervous system (CNS) development are poorly understood. In this study, we identified Zfp488, an oligodendrocyte-specific zinc-finger transcription regulator, by screening for genes downregulated in the optic nerves of Olig1-null mice. The predicted primary structure of Zfp488 is evolutionarily conserved in vertebrates and invertebrates. In the developing CNS, Zfp488 is specifically expressed in oligodendrocytes but not their precursors. Its expression increases in parallel with that of major myelin genes Mbp and Plp1. Zfp488 is a nuclear protein that possesses transcriptional repression activity. In the developing chick neural tube, Zfp488 can promote oligodendrocyte precursor formation upon Notch activation. In addition, Zfp488 can interact and cooperate with the bHLH transcription factor Olig2 to promote precocious and ectopic oligodendrocyte differentiation. Furthermore, knockdown of Zfp488 via RNAi in an oligodendroglial cell line leads to the downregulation of myelin gene expression. Taken together, these data suggest that Zfp488 functions as an oligodendrocyte-specific transcription co-regulator important for oligodendrocyte maturation and that zinc-finger/bHLH cooperation can serve as a mechanism for oligodendroglial differentiation.
Fork head and Sage maintain a uniform and patent salivary gland lumen through regulation of two downstream target genes,PH4αSG1andPH4αSG2
Authors: Abrams Elliott W. , Mihoulides Whitney K. , Andrew Deborah J.
Published: August 2006

(Fkh) is required to block salivary gland apoptosis, internalize salivary gland precursors, prevent expression of duct genes in secretory cells and maintain expression of CrebA, which is required for elevated secretory function. Here, we characterize two new Fkh-dependent genes: PH4αSG1 and PH4αSG2. We show through in vitro DNA-binding studies and in vivo expression assays that Fkh cooperates with the salivary gland-specific bHLH protein Sage to directly regulate expression of PH4αSG2, as well as sage itself, and to indirectly regulate expression of PH4αSG1. PH4αSG1 and PH4αSG2 encode α-subunits of resident ER enzymes that hydroxylate prolines in collagen and other secreted proteins. We demonstrate that salivary gland secretions are altered in embryos missing function of PH4αSG1 and PH4αSG2; secretory content is reduced and shows increased electron density by TEM. Interestingly, the altered secretory content results in regions of tube dilation and constriction, with intermittent tube closure. The regulation studies and phenotypic characterization of PH4αSG1 and PH4αSG2 link Fkh, which initiates tube formation, to the maintenance of an open and uniformly sized secretory tube.
Differential regulation of gene expression in the digit forming area of the mouse limb bud by SHH and gremlin 1/FGF-mediated epithelial-mesenchymal signalling
Authors: Panman Lia , Galli Antonella , Lagarde Nadege , Michos Odysse , Soete Gwen , Zuniga Aimee , Zeller Rolf
Published: August 2006

Spatially and temporally coordinated changes in gene expression are crucial to orderly progression of embryogenesis. We combine mouse genetics with experimental manipulation of signalling to analyze the kinetics by which the SHH morphogen and the BMP antagonist gremlin 1 (GREM1) control gene expression in the digit-forming mesenchyme of mouse limb buds. Although most mesenchymal cells respond rapidly to SHH signalling, the transcriptional upregulation of specific SHH target signals in the mesenchyme occurs with differential temporal kinetics and in a spatially restricted fashion. In particular, the expression of the BMP antagonist Grem1 is always upregulated in mesenchymal cells located distal to the SHH source and acts upstream of FGF signalling by the apical ectodermal ridge. GREM1/FGF-mediated feedback signalling is, in turn, required to propagate SHH and establish the presumptive digit expression domains of the Notch ligand jagged 1(Jag1) and 5′Hoxd genes in the distal limb bud mesenchyme. Their establishment is significantly delayed in Grem1-deficient limb buds and cannot be rescued by specific restoration of SHH signalling in mutant limb buds. This shows that GREM1/FGF feedback signalling is required for regulation of the temporal kinetics of the mesenchymal response to SHH signalling. Finally, inhibition of SHH signal transduction at distinct time points reveals the differential temporal dependence of Grem1, Jag1and 5′Hoxd gene expression on SHH signalling. In particular, the expression of Hoxd13 depends on SHH signal transduction significantly longer than does Hoxd11 expression, revealing that the reverse co-linear establishment, but not maintenance of their presumptive digit expression domains, depends on SHH signalling.
Ionic Liquid-type Crown Ether as a Novel Medium for a Liquid/Liquid Extraction of Radioactive Metal Ion 85Sr2+
Authors: Park Sang Hyun , Demberelnyamba Dorjnamjin , Jang Seung Ho , Byun Myung Woo
Published: August 2006

1,13-Dichloro-4,7,10-trioxatridecane (2-[2-(1-chloro-2-ethoxy)ethoxy]ethyl chloride) (3a) was synthesized by a chlorination of 1,13-dihydroxy-4,7,10-trioxatridecane (triethylene glycol). And it was treated with imidazole and sodium ethoxide to give the 1N,1N′-tris(oxoethylene)-diimidazole (3b), which was then converted to ionic liquid-type crown ether (ILCE) 3 with a reaction with 1,9-dichloro-3,6-trioxaoctane (2a). Further, the anion of ILCE was exchanged by an anion-exchange method. Ultimately, we developed a very efficient synthetic pathway for ILCEs 1–4 which have various physical and chemical characteristics by a modification of the polyethylene glycol chain length and anions. 85Sr2+ was successfully extracted into the [(3,2)OEtIm][Cl] (3) phase, but it was not extracted into the [(2,2)OEtIm][Cl] (1), [(3,3)OEtIm][Cl] (2), and [(4,3)OEtIm][Cl] (4) phases.
Fabrication of Hollow Sb2O3 Microspheres by PEG Coil Template
Authors: Li Binjie , Zhao Yanbao , Xu Xiangmin , Zhang Chunli , Wu Zhishen , Zhang Zhijun
Published: August 2006

PEG coils have been exploited as chemical template to fabricate hollow Sb2O3 microspheres in water–ethanol solution at room temperature. The obtained hollow Sb2O3 microspheres were in the range of about 50–200 nm in diameter, and the shell were in the range of obout 10–20 nm in thickness. In the method, the formation of a certain sized hydrating PEG coil is crucial step, which is related with the process orders.
Preparation of Chiral Polydiacetylene Film from Achiral Monomers Using Circularly Polarized Light
Authors: Manaka Takaaki , Kon Hideki , Ohshima Yuki , Zou Gang , Iwamoto Mitsumasa
Published: August 2006

Formation of chiral polydiacetylene (PDA) film using circularly polarized light (CPL) was demonstrated for the first time. Commercially available achiral derivative of diacetylene was used to prepare the vacuum evaporated monomer film and it was polymerized using ultra-violet CPL. Chiral source was only CPL, and the irradiation of left- and right-CPL definitely yielded opposite chiral polymer.
Crystallized Protein-imprinted Polymer Chips
Authors: Matsunaga Takateru , Takeuchi Toshifumi
Published: August 2006

Protein-imprinted polymer thin films were prepared by using a crystallized protein as a template in aqueous solution. Motifs of surface of crystallized lysozyme can be imprinted and the resulting imprinted polymer thin films showed specific binding behaviors for the template protein.
Synthesis and Characterization of CeO2–ZrO2–Bi2O3 Solid Solutions for Environment-friendly Yellow Pigments
Authors: Masui Toshiyuki , Furukawa Shinya , Imanaka Nobuhito
Published: August 2006

CeO2–ZrO2–Bi2O3 solid solutions have been synthesized by a citrate complex route. The resulting colored materials have been characterized as potential environment-friendly pigments. The yellow hue of the pigment was significantly enhanced by the introduction of zirconium and bismuth into the CeO2 lattice, which produces intrinsic strain and a hybrid orbital of Bi6s and O2p, respectively. The yellow pigments obtained have been found to be effective alternatives to the conventional toxic colored materials.
Layer-by-Layer Molecular Organization of Polypyridine Ruthenium(II) Complexes on Glass Plates
Authors: Kanaizuka Katsuhiko , Kato Shinji , Moriyama Hiroshi , Pac Chongjin
Published: August 2006

We have developed a methodology for the two-dimensional multilayer formation of polypyridine ruthenium complexes on solid surfaces under mild conditions. The alternate multilayers of the ruthenium complex and Zr were fabricated on pretreated glass plates using interlayer phosphonate–Zr linkages. The RuLn molecules in the films are electronically independent, with neither interchromophoric interactions nor electronic perturbations of the ZrIV centers in the ground state.
Synthesis of New Bulky Isocyanide Ligands and Their Use for Rh-catalyzed Hydrosilylation
Authors: Ito Hajime , Kato Takayuki , Sawamura Masaya
Published: August 2006

Bulky isocyanide ligands having meta-terphenyl backbone were developed. Their usefulness as a supporting ligand in catalysis was illustrated by the application to the rhodium-catalyzed hydrosilylation of cyclohexanone. The combined effect of the high ligand affinity to the rhodium atom and the ligand bulkiness to facilitate the formation of a catalytically active, monoligated isocyanide–rhodium species was proposed.
Effect of EDTA and Phosphate on Particle Size during Precipitation of Nanosized BaSO4 Particles
Authors: Zhao Yan-hong , Liu Jin-rong
Published: August 2006

Barium sulfate particles with average size of 16 nm and 203 nm were successfully synthesized by precipitation method at 25 °C. The characterization of BaSO4 particles were performed by X-ray diffraction (XRD), transmission electron microscopy (TEM). It was found that the selected reaction conditions played an important role in controlling the size of particles. The difference in morphology of BaSO4 particles mainly depends on the different additives during the precipitation process.
Occurrence of the Spin-crossover Phenomenon of Assembled Complexes, Fe(NCX)2(bpa)2 (X = S, BH3; bpa = 1,2-Bis(4-pyridyl)ethane) by Enclathrating Organic Guest Molecule
Authors: Morita Takaki , Nakashima Satoru , Yamada Koji , Inoue Katsuya
Published: August 2006

Two assembled complexes, Fe(NCX)2(bpa)2 (X = S, BH3; bpa = 1,2-bis(4-pyridyl)ethane), enclathrating biphenyl or 1,4-dichlorobenzene have been synthesized, whose skeletons are 1D chain, and are revealed to show spin-crossover phenomenon. Transition temperature changes depending on anion and guest molecules.
Smart PEGylated Gold Nanoparticles for the Cytoplasmic Delivery of siRNA to Induce Enhanced Gene Silencing
Authors: Oishi Motoi , Nakaogami Junpei , Ishii Takehiko , Nagasaki Yukio
Published: August 2006

A novel cytoplasmic delivery system of siRNA was developed by complexation between poly(ethylene glycol)-block-poly(2-(N,N-dimethylamino)ethyl methacrylate) copolymer (PEG–PAMA) and gold nanoparticles (GNPs), followed by the immobilization of siRNA bearing a thiol group (SH-siRNA). The PEGylated GNPs containing SH-siRNA showed a significant RNAi activity in HuH-7 cells.
Oxidation of Thiols to Disulfides Using Silica Chloride as a Heterogeneous Catalyst
Authors: Sathe Manisha , Ghorpade Ramarao , Kaushik Mahabir Parshad
Published: August 2006

Silica chloride is used as a selective and effective heterogeneous catalyst for the rapid conversion of thiols to disulfides with quantitative yields in a very short period of time.
Thioglycolic Acid-assisted Solvothermal Synthesis of CuInS2 with Controllable Microstructures
Authors: Gou Xinglong , Peng Shengjie , Zhang Li , Shi Yunhui , Chen Jun , Shen Panwen
Published: August 2006

A facile solvothermal approach assisted by thioglycolic acid (TGA) was developed to control the morphologies and microstructures of CuInS2. Furthermore, the band gap of the CuInS2 microspheres was tunable in the range of 1.50–1.76 eV, depending on the synthetic conditions.
Water Splitting into H2 and O2 over Ba5Nb4O15 Photocatalysts with Layered Perovskite Structure Prepared by Polymerizable Complex Method
Authors: Miseki Yugo , Kato Hideki , Kudo Akihiko
Published: August 2006

Photophysical and photocatalytic properties of Ba5Nb4O15 with four-layered perovskite structure were investigated. The band gap of Ba5Nb4O15 was 3.9 eV. A broad emission band of green photoluminescence was observed at 77 K. NiO/Ba5Nb4O15 pretreated by H2 reduction followed by O2 oxidation showed a high activity for water splitting under UV light irradiation.
Porous Chiral Metal Organic Carboxylate Frameworks with a Double-interwoven SrSi2 Topology: M3(TTCA)2·6DMF·7H2O (TTCA = triphenylenetricarboxylate; M = Zn2+, Cd2+)
Authors: Choi Jae Yong , Kim Jeo , Furukawa Hiroyasu , Chae Hee K
Published: August 2006

We have succeeded in assembling a new trigonal aryne ligand, triphenylene-2,6,10-tricarboxylic acid (H3TTCA) with metal ions to give M3(TTCA)2·6DMF·7H2O (M = Zn2+ and Cd2+) (DMF = N,N-dimethylformamide), which networks show non-interpenetrated porous metal carboxylate frameworks and belong to a novel doubly-interwoven SrSi2 topology.
An ensemble Kalman filter for short‐term forecasting of tropospheric ozone concentrations
Authors: Eben K. , Juruş P. , Resler J. , Belda M. , Pelikán E. , Krüger B. C. , Keder J.
Published: August 2006

An air‐quality forecasting system based on the pair ‘NWP model MM5–chemistry transport model CAMx’ is proposed. A version of the ensemble Kalman Filter has been developed. The model‐error covariance matrix is parametrized with the help of a covariance function and represented by an ensemble formed as a random selection from leading eigenvectors. The performance of the system is tested on the case of an ozone episode in June 2001. As a source of observations, the AirBase database has been used. Starting the forecast from analysed concentration fields improves the quality of forecast of the next day's ozone concentration maxima. Copyright © 2005 Royal Meteorological Society
An overview of the variational assimilation in the ALADIN/France numerical weather‐prediction system
Authors: Fischer Claude , Montmerle Thibaut , Berre Loïk , Auger Ludovic , ŞTEFĂNESCU Simona Ecaterina
Published: August 2006

We present an overview of the 3D‐Var data assimilation in the framework of the ALADIN/France model. The purpose of this system is to provide improved precipitation forecasts at mesoscale and in the short range, up to 18 hours. The goal of the paper is threefold. Firstly, we present initial considerations for the design of the 3D‐Var system. Secondly, we discuss in more detail the specification of the background‐error covariance matrix, by comparing three different error simulation techniques, namely two variants of the NMC method and an ensemble‐based approach. The formal, diagnostic and impact studies have led to the selection of the ensemblebased covariances for the ALADIN/France assimilation. Thirdly, scores of quantitative precipitation forecasts are shown in order to illustrate the robustness and the preliminary meteorological performance of the ALADIN/France assimilation suite. The results indicate that the tested configuration improves some aspects of the precipitation forecast, while being neutral for others, when compared with the spin‐up model.

We conclude the paper by providing a more explicit insight into the future evolution of limited‐area variational analysis towards convective‐scale data assimilation. Copyright © 2005 Royal Meteorological Society
Overview of global data assimilation developments in numerical weather‐prediction centres
Authors: Rabier Florence
Published: August 2006

Recent data assimilation developments which have taken place at numerical weather‐prediction centres are briefly discussed, from the perspectives of both the importance of data and algorithmic developments. The increase in quality and quantity of satellite data is seen to play a major role in the improvement of forecast performance, particularly in the southern hemisphere. Further optimization of the use of observations is possible through the proper evaluation of data impact and the optimization of the amount of data to be assimilated. The generalized advent of four‐dimensional variational assimilation is presented, and trends in the specification of error statistics are described. Finally, a more interactive forecasting system including an adaptive component is a new challenge to bring additional improvement to the forecasting of high‐impact weather. Copyright © 2005 Royal Meteorological Society
Some challenges of middle atmosphere data assimilation
Authors: Polavarapu S. , Shepherd T. G. , ROCHON Y. , REN S.
Published: August 2006

The assimilation of measurements from the stratosphere and mesosphere is becoming increasingly common as the lids of weather prediction and climate models rise into the mesosphere and thermosphere. However, the dynamics of the middle atmosphere pose specific challenges to the assimilation of measurements from this region. Forecast‐error variances can be very large in the mesosphere and this can render assimilation schemes very sensitive to the details of the specification of forecast error correlations. An example is shown where observations in the stratosphere are able to produce increments in the mesosphere. Such sensitivity of the assimilation scheme to misspecification of covariances can also amplify any existing biases in measurements or forecasts. Since both models and measurements of the middle atmosphere are known to have biases, the separation of these sources of bias remains a issue. Finally, well‐known deficiencies of assimilation schemes, such as the production of imbalanced states or the assumption of zero bias, are proposed explanations for the inaccurate transport resulting from assimilated winds. The inability of assimilated winds to accurately transport constituents in the middle atmosphere remains a fundamental issue limiting the use of assimilated products for applications involving longer time‐scales. Copyright © 2005 Royal Meteorological Society
JRA‐25: Japanese 25‐year re‐analysis project—progress and status
Authors: Onogi Kazutoshi , Koide Hiroshi , Sakamoto Masami , Kobayashi Shinya , Tsutsui Junichi , Hatsushika Hiroaki , Matsumoto Takanori , Yamazaki Nobuo , Kamahori Hirotaka , Takahashi Kiyotoshi , Kato Koji , Oyama Ryo , Ose Tomoaki , Kadokura Shinji , Wada Koji
Published: August 2006

The progress and status of a new atmospheric re‐analysis, JRA‐25 the Japanese 25‐year Re‐analysis which covers the 26 years from 1979 to 2004, are introduced. Observational data include some newly produced for JRA‐25 and advantages and drawbacks of performance are briefly described. JRA‐25 has many advantages such as its handling of precipitation amounts, tropical cyclone analysis, and the extent of low‐level cloud along western continents that are among the best compared to other re‐analyses. The snow analysis is also good and stable. JRA‐25 outputs analysis products every 6 hours. Copyright © 2005 Royal Meteorological Society
Adaptive thinning of atmospheric observations in data assimilation with vector quantization and filtering methods
Authors: Ochotta T. , Gebhardt C. , Saupe D. , Wergen W.
Published: August 2006

In data assimilation for numerical weather prediction, measurements of various observation systems are combined with background data to define initial states for the forecasts. Current and future observation systems, in particular satellite instruments, produce large numbers of measurements with high spatial and temporal density. Such datasets significantly increase the computational costs of the assimilation and, moreover, can violate the assumption of spatially independent observation errors. To ameliorate these problems, we propose two greedy thinning algorithms, which reduce the number of assimilated observations while retaining the essential information content of the data. In the first method, the number of points in the output set is increased iteratively. We use a clustering method with a distance metric that combines spatial distance with difference in observation values. In a second scheme, we iteratively estimate the redundancy of the current observation set and remove the most redundant data points. We evaluate the proposed methods with respect to a geometric error measure and compare them with a uniform sampling scheme. We obtain good representations of the original data with thinnings retaining only a small portion of observations. We also evaluate our thinnings of ATOVS satellite data using the assimilation system of the Deutscher Wetterdienst. Impact of the thinning on the analysed fields and on the subsequent forecasts is discussed. Copyright © 2005 Royal Meteorological Society
Air Oxidation of Carbon Spheres. II. Micropore Development
Authors: Inagaki Michio , Nishikawa Tetsuo , Oshida Kyoiti , Fukuyama Katsuya , Hatakeyama Yoshikiyo , Nishikawa Keiko
Published: August 2006

The formation of micropores at the start of the oxidation of carbon spheres was studied by N2 gas adsorption, small-angle X-ray scattering and transmission electron microscopy with the aid of image processing. On the basis of a detailed analysis of the measurement results, it was suggested that the principal process in the formation of micropores was the opening of closed pores initially present in the carbon matrix of the spheres. The fact that these closed pores were formed during carbonization as the nano-texture of glass-like carbons suggests that the carbonization process may govern the size of the micropores formed at the start of the oxidation process employed for activating such activated carbon precursors.
Adsorption in Slit Pores and Pore-Size Distribution: A Molecular Layer Structure
Authors: Ustinov E.A. , Do D.D.
Published: August 2006

Anew approach is developed to analyze the thermodynamic properties of a sub-critical fluid adsorbed in a slit pore of activated carbon. The approach is based on a representation that an adsorbed fluid forms an ordered structure close to a smoothed solid surface. This ordered structure is modelled as a collection of parallel molecular layers. Such a structure allows us to express the Helmholtz free energy of a molecular layer as the sum of the intrinsic Helmholtz free energy specific to that layer and the potential energy of interaction of that layer with all other layers and the solid surface. The intrinsic Helmholtz free energy of a molecular layer is a function (at given temperature) of its two-dimensional density and it can be readily obtained from bulk-phase properties, while the interlayer potential energy interaction is determined by using the 10–4 Lennard-Jones potential. The positions of all layers close to the graphite surface or in a slit pore are considered to correspond to the minimum of the potential energy of the system.

This model has led to accurate predictions of nitrogen and argon adsorption on carbon black at their normal boiling points. In the case of adsorption in slit pores, local isotherms are determined from the minimization of the grand potential. The model provides a reasonable description of the 0–1 monolayer transition, phase transition and packing effect. The adsorption of nitrogen at 77.35 K and argon at 87.29 K on activated carbons is analyzed to illustrate the potential of this theory, and the derived pore-size distribution is compared favourably with that obtained by the Density Functional Theory (DFT). The model is less time-consuming than methods such as the DFT and Monte-Carlo simulation, and most importantly it can be readily extended to the adsorption of mixtures and capillary condensation phenomena.
Adsorption of an Amphoteric Aromatic Compound (p-Aminobenzoic Acid) onto Different Polymeric Adsorbents
Authors: Wang Hai-Ling , Chen Jin-Long , Zhang Quan-Xing
Published: August 2006

The adsorptive properties of p-aminobenzoic acid onto macroporous, hypercrosslinked and multi-functional polymeric adsorbents were investigated systematically in the present study in relation to the particular physicochemical characteristics of an aromatic amphoteric compound containing both Lewis acid and Lewis base functional groups. A comparison of the thermodynamic and kinetic behaviours of the adsorbate towards three different polymeric adsorbents was made. It was found that the equilibrium adsorption data for the three polymeric adsorbents were well fitted by the empirical Freundlich isotherm. The results showed that the adsorption capacity of the multi-functional polymeric adsorbent NJ-99 was the largest among the three adsorbents studied. This may be attributed to strong hydrogen-bonding interaction and electrostatic interaction between the amino groups on the resin and the carboxyl group of p-aminobenzoic acid. In contrast, because of its smaller micropore volume, the adsorption capacity of macroporous XAD-4 was lower than that of the hypercrosslinked adsorbents CHA-111 and NJ-99. Calculation of the sorption enthalpy changes enabled the adsorption mechanism to be interpreted. In addition, a kinetic study of the sorption of p-aminobenzoic acid onto NJ-99 was also undertaken. The results showed that the adsorption process was mainly controlled by intraparticle diffusion.
Adsorption Characteristics of Fumaric Acid onto Weakly Basic Hypercrosslinked Polystyrene Ion-Exchangers
Authors: Xu Chao , Long Chao , Li Aimin , Liu Fuqiang , Yang Weiben , Zhang Quanxing
Published: August 2006

A new weakly basic ion-exchanger (called XC-11), with a hypercrosslinked macroporous polystyrene matrix and a high specific surface area, was synthesized. When traditional weakly basic ion-exchange resins were employed in adsorption experiments, it was found that their sphericity after attrition decreased drastically when they were used ten times cyclically to adsorb and desorb fumaric acid from actual manufacturing effluent. This indicated that a traditional weakly basic exchange resin could not be applied in practice for the recovery of fumaric acid from industrial wastewater. However, the mechanical strengths of the self-synthesized new weakly basic ion-exchanger XC-11 and the hypercrosslinked polymeric adsorbent NDA-150 remained virtually unchanged under the same conditions, indicating their feasibility for practical applications.

Thus, the adsorption of fumaric acid from aqueous solutions onto XC-11 and the commercially available hypercrosslinked polymeric adsorbent (NDA-150) taken as a reference was investigated from both a dynamic and thermodynamic standpoint. Favourable adsorption behaviour towards fumaric acid was observed with both adsorbents, the equilibrium adsorption data obtained being very well fitted by the Freundlich model. The corresponding Freundlich constants, KF, and free energy changes, ΔG, indicated that the adsorption capacity of XC-11 towards fumaric acid was greater than that of NDA-150. The pseudo-first-order and pseudo-second-order kinetic models were applied to describe the kinetic data, with the pseudo-second-order model providing a perfect fit. It was also found that the adsorption of fumaric acid onto XC-11 proceeded faster than the corresponding process onto NDA-150.
Crosslinking of Chitosan with a Trifunctional Crosslinker and the Adsorption of Acid Dyes and Metal Ions onto the Resulting Polymer
Authors: Shimizu Yoshiaki , Saito Yoshihiro , Nakamura Takeo
Published: August 2006

Novel chitosan-based adsorbent materials were synthesized using a trifunctional reagent as a crosslinker and the adsorption capability of the resulting polymers towards two acid dyes and several metal ions was evaluated. The crosslinked chitosan with the lowest degree of substitution showed a very high adsorption capability towards CI Acid Orange 7. Decreasing the degree of substitution and the pH of the dye solution led to an increase in the adsorption capability. The crosslinked chitosan with the lowest degree of substitution exhibited quite remarkable adsorption powers towards the Cu2+ ion. Such adsorption towards divalent metal ions decreased in the following sequence: Cu2+ » Ni2+ > Cd2+, Pb2+, Ca2+.
Adsorption Separation of Methyl Chloride from Nitrogen Using ZSM-5 and Mesoporous SBA-15
Authors: Toreci Isil , Tezel F. Handan , Yong Yang , Sayari Abdelhamid
Published: August 2006

The adsorption capacities of zeolite ZSM-5 and periodic mesoporous molecular sieve SBA-15 towards methyl chloride (chloromethane) and nitrogen were examined for the separation of these gases. Adsorption isotherms were obtained by using a constant volume technique up to 1.6 atm over the temperature range 40–80°C. The Langmuir, Freundlich, Sips and Toth adsorption models were fitted to the isotherms and validations of these models were discussed. Adsorption isosteres were obtained by using the parameters of the Toth equation. Binary adsorption isotherm predictions were undertaken using the Extended Langmuir (EL) and Ideal Adsorbed Solution Theory (IAST) in order to obtain a better understanding of the separation of methyl chloride from air. Henry's law constants, heats of adsorption and separation factors for both adsorbents were also obtained.