bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of Meso-/Macroporous Zeolite (Fe,Al)-ZSM-5 Microspheres from Diatomite
Authors: Shan Wei , Zhang Yahong , Wang Yajun , Xia Jianchao , Tang Yi 
Published: February 2004

Abstract
Microspheres of (Fe,Al)-ZSM-5 crystallite aggregates with abundant meso-/macropores have been synthesized by hydrothermal treatment of natural diatomite in a NaCl-containing solution. It was found that the addition of NaCl would lead to the formation of spherical product as well as promoting the incorporation of the Fe originally existed in diatomite into zeolitic framework.
An Efficient and Green Synthesis of 2-Arylbenzothiazoles in an Ionic Liquid, [pmIm]Br under Microwave Irradiation
Authors: Ranu Brindaban C , Jana Ranjan , Dey Suvendu S 
Published: February 2004

Abstract
An efficient and green procedure for the synthesis of 2-arylbenzothiazoles has been developed by a simple condensation of 2-aminothiophenol and aromatic aldehyde in an inexpensive ionic liquid, 1-pentyl-3-methylimidazolium bromide ([pmIm]Br) by microwave irradiation under solvent and catalyst-free condition. The ionic liquid is recycled for subsequent reactions.
Do otolaryngology out-patients use the internet prior to attending their appointment?
Authors: Tassone Peter , Georgalas Christos , Patel Nimesh N. , Appleby Esther , Kotecha Bhik 
Published: January 2004

The Internet has become a very important source of health information. We wanted to determine otolaryngology patients’ access to, and use of, the Internet as a medical information resource, to identify factors that make patients more likely to use it, and to determine how useful they find this information.A questionnaire survey was completed by patients while waiting for their consultation in the out-patient department of the Royal National Throat Nose and Ear Hospital in London. Five hundred and thirty-five questionnaires were completed. Sixty-four per cent (344/535) reported having access to the Web. Of the 344 with access, 62 (18 per cent) had searched the Web for medical information prior to their consultation. Higher education (p <0.001) and age between 18 and 40 years (p = 0.001) correlated significantly with higher Internet use. Ninety-five per cent planned to use the Internet again.Approximately one out of five otolaryngology out-patients with Internet access reported having obtained medical information from the Web before their consultation. The majority found it helpful to some degree and were planning to use it again. As clinicians we should be aware ofthis use and the onus should be on ourselves to review these sites in order to guide our patients to sources of reliable and helpful medical information on the Internet.
Molecular Basis of Gap Junctional Communication in the CNS of the LeechHirudo medicinalis
Authors: Dykes Iain M. , Freeman Fiona M. , Bacon Jonathan P. , Davies Jane A. 
Published: January 2004

Gap junctions are intercellular channels that allow the passage of ions and small molecules between cells. In the nervous system, gap junctions mediate electrical coupling between neurons. Despite sharing a common topology and similar physiology, two unrelated gap junction protein families exist in the animal kingdom. Vertebrate gap junctions are formed by members of the connexin family, whereas invertebrate gap junctions are composed of innexin proteins. Here we report the cloning of two innexins from the leechHirudo medicinalis. These innexins show a differential expression in the leech CNS:Hm-inx1is expressed by every neuron in the CNS but not in glia, whereasHm-inx2is expressed in glia but not neurons. Heterologous expression in the pairedXenopusoocyte system demonstrated that both innexins are able to form functional homotypic gap junctions.Hm-inx1forms channels that are not strongly gated. In contrast,Hm-inx2forms channels that are highly voltage-dependent; these channels demonstrate properties resembling those of a double rectifier. In addition,Hm-inx1andHm-inx2are able to cooperate to form heterotypic gap junctions inXenopusoocytes. The behavior of these channels is primarily that predicted from the properties of the constituent hemichannels but also demonstrates evidence of an interaction between the two.This work represents the first demonstration of a functional gap junction protein from a Lophotrochozoan animal and supports the hypothesis that connexin-based communication is restricted to the deuterostome clade.
Cyclin-Dependent Kinase 5 Phosphorylates the N-Terminal Domain of the Postsynaptic Density Protein PSD-95 in Neurons
Authors: Morabito Maria A. , Sheng Morgan , Tsai Li-Huei 
Published: January 2004

PSD-95 (postsynaptic density 95) is a postsynaptic scaffolding protein that links NMDA receptors to the cytoskeleton and signaling molecules. The N-terminal domain of PSD-95 is involved in the synaptic targeting and clustering of PSD-95 and in the clustering of NMDA receptors at synapses. The N-terminal domain of PSD-95 contains three consensus phosphorylation sites for cyclin-dependent kinase 5 (cdk5), a proline-directed serine-threonine kinase essential for brain development and implicated in synaptic plasticity, dopamine signaling, cocaine addiction, and neurodegenerative disorders.We report that PSD-95 is phosphorylated in the N-terminal domain by cdk5in vitroandin vivo, and that this phosphorylation is not detectable in brain lysates of cdk5–/– mice. N-terminal phosphorylated PSD-95 is found in PSD fractions together with cdk5 and its activator, p35, suggesting a role for phosphorylated PSD-95 at synapses. In heterologous cells, coexpression of active cdk5 reduces the ability of PSD-95 to multimerize and to cluster neuronal ion channels, two functions attributed to the N-terminal domain of PSD-95. Consistent with these observations, the lack of cdk5 activity in cultured neurons results in larger clusters of PSD-95. In cdk5–/– cortical neurons, more prominent PSD-95 immunostained clusters are observed than in wild-type neurons. In hippocampal neurons, the expression of DNcdk5 (inactive form of cdk5) or of the triple alanine mutant (T19A, S25A, S35A) full-length PSD-95 results in increased PSD-95 cluster size.These results identify cdk5-dependent phosphorylation of the N-terminal domain of PSD-95 as a novel mechanism for regulating the clustering of PSD-95. Moreover, these observations support the possibility that cdk5-dependent phosphorylation of PSD-95 dynamically regulates the clustering of PSD-95/NMDA receptors at synapses, thus providing a possible mechanism for rapid changes in density and/or number of receptor at synapses.
Effect of Temperature and Illumination on the Electrical Characteristics of Polymer–Fullerene Bulk‐Heterojunction Solar Cells
Authors: Riedel I. , Parisi J. , Dyakonov V. , Lutsen L. , Vanderzande D. , Hummelen J. C. 
Published: January 2004

AbstractThe current–voltage characteristics of ITO/PEDOT:PSS/OC1C10‐PPV:PCBM/Al solar cells were measured in the temperature range 125–320 K under variable illumination, between 0.03 and 100 mW cm–2 (white light), with the aim of determining the efficiency‐limiting mechanism(s) in these devices, and the temperature and/or illumination range(s) in which these devices demonstrate optimal performance. (ITO: indium tin oxide; PEDOT:PSS: poly(styrene sulfonate)‐doped poly(ethylene dioxythiophene); OC1C10‐PPV: poly[2‐methoxy‐5‐(3,7‐dimethyl octyloxy)‐1,4‐phenylene vinylene]; PCBM: phenyl‐C61 butyric acid methyl ester.) The short‐circuit current density and the fill factor grow monotonically with temperature until 320 K. This is indicative of a thermally activated transport of photogenerated charge carriers, influenced by recombination with shallow traps. A gradual increase of the open‐circuit voltage to 0.91 V was observed upon cooling the devices down to 125 K. This fits the picture in which the open‐circuit voltage is not limited by the work‐function difference of electrode materials used. The overall effect of temperature on solar‐cell parameters results in a positive temperature coefficient of the power conversion efficiency, which is 1.9 % at T = 320 K and 100 mW cm–2 (2.5 % at 0.7 mW cm–2). The almost‐linear variation of the short‐circuit current density with light intensity confirms that the internal recombination losses are predominantly of monomolecular type under short‐circuit conditions. We present evidence that the efficiency of this type of solar cell is limited by a light‐dependent shunt resistance. Furthermore, the electronic transport properties of the absorber materials, e.g., low effective charge‐carrier mobility with a strong temperature dependence, limit the photogenerated current due to a high series resistance, therefore the active layer thickness must be kept low, which results in low absorption for this particular composite absorber.
Synthesis and Properties of a Water‐Soluble Single‐Walled Carbon Nanotube–Poly(m‐aminobenzene sulfonic acid) Graft Copolymer
Authors: Zhao B. , Hu H. , Haddon R. C. 
Published: January 2004

AbstractPoly(m‐aminobenzene sulfonic acid) (PABS), was covalently bonded to single‐walled carbon nanotubes (SWNTs) to form a water‐soluble nanotube–polymer compound (SWNT–PABS). The conductivity of the SWNT–PABS graft copolymer was about 5.6 × 10–3 S cm–1, which is much higher than that of neat PABS (5.4 × 10–7 S cm–1). The mid‐IR spectrum confirmed the formation of an amide bond between the SWNTs and PABS. The 1H NMR spectrum of SWNT–PABS showed the absence of free PABS, while the UV/VIS/NIR spectrum of SWNT–PABS showed the presence of the interband transitions of the semiconducting SWNTs and an absorption at 17 750 cm–1 due to the PABS addend.
Octupolar Dendrimers with Large First Hyperpolarizability
Authors: Jeong H. C. , Piao M. J. , Lee S. H. , Jeong M.‐Y. , Kang K. M. , Park G. , Jeon S.‐J. , Cho B. R. 
Published: January 2004

AbstractA series of 1,3,5‐tricyano‐2,4,6‐tris(styryl)benzene derivatives (1,2) and dendrimers (3) have been synthesized and their first hyperpolarizabilities (β) were determined. Whereas the λmax values of 1–3 are similar, the oscillator strength increases with the molecular size. For all compounds, the Stokes shifts are significantly larger when NAr2 is used as the donor. The β(0) values of 1–3 range from 252 to 507 × 10–30 esu and increases with the number of octupolar units in the molecule. When the octupolar molecules are linked to the 1,3,5‐position of the benzene ring by flexible ether linkages, the β(0) value increases by 1.7 fold. On the other hand, octupolar monodendron based on the nitrogen atom core and 1,3,5‐tricyano‐2,4,6‐tris(p‐diarylaminostyryl)benzene moieties at the periphery exhibits β(0) = 507 × 10–30 esu, which is one of the largest β(0) values reported for the octupolar molecules.
Color Tuning in Benzo[1,2,5]thiadiazole‐Based Small Molecules by Amino Conjugation/Deconjugation: Bright Red‐Light‐Emitting Diodes
Authors: Justin Thomas K. R. , Lin J. T. , Velusamy M. , Tao Y.‐T. , Chuen C.‐H. 
Published: January 2004

AbstractBipolar compounds (referred to in general as btza) containing a benzo[1,2,5]thiadiazole core and peripheral diarylamines and/or 4‐tert‐butylphenyl moieties have been synthesized via palladium‐catalyzed cross‐coupling reactions of 4,7‐dibromobenzo[1,2,5]thiadiazole with appropriate stannyl compounds. These compounds are fluorescent and the emission color ranges from green to red. The fluorescence of the compounds originates from a charge‐transfer process and exhibits solvatochromism. These red‐light‐emitting materials are amorphous and devices of different configurations were fabricated: I) ITO/btza/TPBI/Mg:Ag; II) ITO/btza/Alq3/Mg:Ag; III) ITO/btza/Mg:Ag (where ITO = indium tin oxide, TPBI = 1,3,5‐tris(N‐phenylbezimidazol‐2‐yl)benzene, and Alq3 = tris(8‐hydroxyquinoline)aluminum). The performance of some of the red‐light‐emitting devices appears to be very promising.
Crystallographic report: (2,2′‐Bipyridyl)bis(ethanoldithiocarbamato)zinc(II)
Authors: Saravanan M. , Ramalingam K. , Bocelli G. , Cantoni A. 
Published: January 2004

AbstractZn(meadtc)2(2,2′‐bipy) is a ZnS3N2 chromophore with a distorted square pyramidal geometry. The IR band at 1002 cm−1 and the bond valence sum value of 1.98 confirmed the monodentate dithiocarbamate in coordination. The non‐bonding Zn–S distance is 5.004(3) Å. Copyright © 2004 John Wiley & Sons, Ltd.
Organosilicon(IV) and organotin(IV) complexes as biocides and nematicides: synthetic, spectroscopic and biological studies of N∩N donor sulfonamide imine and its chelates
Authors: Jain Mukta , Gaur Shweta , Singh V. P. , Singh R. V. 
Published: January 2004

AbstractA brief account is given of the synthesis and stereochemistry and the antibacterial, antifungal, nematicidal and insecticidal behaviour of organosilicon(IV) and organotin(IV) complexes of a biologically potent ligand, 2‐acetylfuransulfaguanidine. The unimolar and bimolar substitution products have been characterized by elemental analyses, conductance measurements, molecular weight determinations, and spectral studies, viz. IR, 1H NMR, 13C NMR, UV, 29Si NMR and 119Sn NMR spectra. The data support the binding of the nitrogen atom to the metal atom in R3M(N∩N), [R2M(N∩N)2 and R2M(N∩N)Cl [(R = Me/Ph and M = Si(IV) and Sn(IV)] types of complex. Based on these studies, with coordination number five and six a trigonal bipyramidal and an octahedral geometry have been proposed for the resulting derivatives. The free ligand (N∩NH) and its respective metal complexes were tested in vitro against a number of microorganisms to assess their antimicrobial properties. The results are indeed positive. In addition to these studies, the complexes also show good nematicidal and insecticidal properties. The results of these findings have been discussed in detail. Copyright © 2004 John Wiley & Sons, Ltd.
Crystallographic report: catena‐Aqua(2,2′‐bipyrimidine)lithium(I) perchlorate
Authors: Tong Ming‐Liang , Hu Sheng , Yu Xiao‐Lan , Chen Xiao‐Ming 
Published: January 2004

AbstractA lithium(I) coordination polymer has been formed from LiClO4 and the 2,2′‐bipyrimidine (bpym) ligand in which each square pyramidal lithium(I) atom is coordinated in the basal plane by four nitrogen donor atoms derived from two bpym ligands and one water molecule at the apical position. These are connected into a layer structure via hydrogen‐bonding interactions involving the perchlorate anions. Copyright © 2004 John Wiley & Sons, Ltd.
Crystallographic report: A two‐dimensional layer structure containing calcium: [Ca3(1,3,5‐benzenetricarboxylate)2(H2O)12]n
Authors: Yang Yang‐Yi , Huang Zhong‐Qi , Szeto Lap , Wong Wing‐Tak 
Published: January 2004

AbstractIn the crystal structure, an eight‐coordinated calcium center is connected to adjacent seven‐coordinated calcium ions by a pair of µ‐aqua bridging ligands, leading to the formation of a chain, which is linked via benzenetricarboxylate ligands to neighboring chains to furnish a two‐dimensional layer structure. Layers are connected into a three‐dimensional structure facilitated by hydrogen bonding interactions. Copyright © 2004 John Wiley & Sons, Ltd.
Short communication: An alternative and effective catalyst for the silastannation of arylacetylenes with Me3SiSnBu3 at room temperature
Authors: Nakano Taichi , Miyamoto Takashi , Endoh Takanori , Shimotani Makoto , Ashida Naoki , Morioka Toshishige , Takahashi Yutaka 
Published: January 2004

AbstractThe palladium‐catalyzed silastannation of acetylenes with tributyl(trimethylsilyl)stannane in the presence of triethylphosphite is reported for the first time. The reaction occurs at room temperature to give (Z)‐silyl(stannyl)ethenes in high yields. The protodemetallation of the resulting adducts with HCl–tetraethylammonium chloride is described first, which demonstrates that the reaction is governed only by the stability of a carbonium ion arising from the protonation to (Z)‐silyl(stannyl)ethenes rather than the hard and soft acid and base principle, i.e. the β‐cation stabilization effect (σ–π stabilization one) of a stannyl group in the carbonium ion is rather significant. Copyright © 2004 John Wiley & Sons, Ltd.
Crystallographic report: Bis(N,N‐dibenzyldithiocarbamato)mercury(II)
Authors: Lai Chian Sing , Tiekink Edward R. T. 
Published: January 2004

AbstractThe monomeric structure of Hg[S2CN(CH2Ph)2]2, in which the mercury atom lies on a two fold axis that relates the unsymmetrically chelating dithiocarbamate ligands, features a severely distorted tetrahedral geometry. Copyright © 2004 John Wiley & Sons, Ltd.
Crystallographic report: Ethyltriphenyltin(IV), Et(Ph)3Sn
Authors: Casas José S. , Castellano Eduardo E. , Ellena Javier , García‐Tasende María S. , Goméz‐Torres Juán P. , Sánchez Agustín , Sordo José 
Published: January 2004

AbstractThe crystal lattice of the title compound comprises isolated molecules. The coordination polyhedron is a slightly distorted tetrahedron with C–Sn–C bond angles ranging from 106.62(17)° to 113.9(3)°. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis of Curcumin Analogues as Potential Antioxidant, Cancer Chemopreventive Agents
Authors: Youssef Khairia M. , El‐Sherbeny Magda A. , El‐Shafie Faiza S. , Farag Hassan A. , Al‐Deeb Omar A. , Awadalla Sit Albanat A. 
Published: January 2004

AbstractNew series of 3, 5‐bis(substituted benzylidene)‐4‐piperidones, 2, 7‐bis(substituted benzylidene)cycloheptanones, 1, 5‐bis(substituted phenyl)‐1, 4‐pentadien‐3‐ones, 1, 7‐bis(substituted phenyl)‐1, 6‐heptadien‐3, 5‐diones, 1, 1‐bis(substituted cinnamoyl)‐cyclopentanes, and 1, 1‐bis(substituted cinnamoyl)cyclohexanes have been synthesized and tested for their antioxidant activity. Among the tested compounds, compounds II4, II9 II10, II11, V1, and V4 exhibited higher free radical scavenger activity with % inhibition values of 90.71, 91.24, 96.91, 94.26, 99.23, and 99.85%, respectively. Moreover, compound V1 is the safest member toward peripheral multinuclear neutrophils (PMNs) with a % viability value of 91%. Detailed synthesis, spectroscopic, and biological data are reported.
Synthesis of New Pyrrolo[2, 3‐b]pyridines as a Potent Inhibitor of Tumour Necrosis Factor Alpha
Authors: Hilmy Khalid Mohammed Hassan 
Published: January 2004

AbstractThe MAP kinase p38 plays a key role in the biosynthesis of the inflammatory cytokines tumor necrosis factor α (TNF‐α) and 1L‐1β. Accordingly, new pyrrolo[2, 3‐]pyridine derivatives 5a—d were prepared from 2‐amino‐3‐cyanopyrroles 3a—d via the intermediate propenylaminopyrroles 4a—d. Then the compounds 5a—d were tested for their ability to inhibit the production of TNF‐α in vivo in rats. The most potent compounds 5a and 5b possess enhanced ability to inhibit the production of TNF‐α stimulated with bacterial lipopolysaccharide.
Styrylquinazolines: A New Class of Inhibitors on Prostaglandin E2 Production in Lipopolysaccharide‐activated Macrophage Cells
Authors: Park Jang Hyun , Min Hye‐Young , Kim Sun Suk , Lee Jae Yeol , Lee Sang Kook , Lee Yong Sup 
Published: January 2004

AbstractA series of styrylquinazoline derivatives (2a—k) were prepared and evaluated for their inhibiton of prostaglandin E2 (PGE2) production by cyclooxygenase‐2 (COX‐2). The latter was induced by lipopolysaccharide‐stimulated macrophage cells RAW264.7.3′, 4′‐Dihydroxylated styrylquinazolines (2a—c), 3′‐hydroxylated styrylquinazolines (2h, 2i), and 3′‐acetoxy‐styrylquinazolines (2j, 2k) exhibited good inhibitory effects of PGE2 production by COX‐2 with a range of IC50 values of 1.19 ∼ 3.56 μM. The potencies were comparable or better than that of the representative stilbene resveratrol (IC50 = 3.07 μM). These results indicate that styrylquinazolines can be considered as potential resveratrol analogues in the modulation of prostaglandin production by COX‐2.
Synthesis and Antihypertensive Activity of 1‐(2‐Thiazolyl)‐3, 5‐disubstituted ‐2‐Pyrazolines
Authors: Bagheri Maryam , Shekarchi Maryam , Jorjani Masoumeh , Ghahremani Mohammad Hossein , Vosooghi Mohssen , Shafiee Abbas 
Published: January 2004

AbstractSeveral substituted 3‐aryl‐1‐(4‐aryl‐2‐thiazolyl)‐5‐(3‐pyridyl)‐2‐pyrazolines were synthesized by reacting substituted 3‐aryl‐5‐(3‐pyridyl)‐1‐thiocarbamoyl‐2‐pyrazolines with phenacyl bromide in ethanol. The structures of all compounds were confirmed by IR, 1H‐NMR, mass spectral data and elemental analyses. The antihypertensive activity of compounds was examined by the tail‐cuff method and compared with clonidine. Compounds 24—28 showed significant antihypertensive activity.
High‐humidity performance of paperboard after treatment with xylanase, endoglucanse, and their combination
Authors: Wong Ken K. Y. , Hamilton Nathan T. , Signal Frances A. , Campion Sylke H. 
Published: January 2004

AbstractFor paperboard used to produce packaging, treatment of its fiber constituents with commercial enzymes can improve its compressive strength under cycling and high‐humidity conditions. Xylanase that selectively removes pulp xylan (ca. 2% of the pulp by mass) yielded most of the observed beneficial effects, which did not appear related to the packing of the fiber network in the sheet or to the uptake of moisture at high humidity. There was also a marginal increase in the drainability of the pulp slurry, which may increase the rate of papermaking. Although endoglucanase activity also enhances certain pulp properties, there was little benefit in adding it to the xylanase treatment. © 2004 Wiley Periodicals, Inc.
Restructuring upstream bioprocessing: technological and economical aspects for production of a generic microbial feedstock from wheat
Authors: Koutinas A. A. , Wang R. , Webb C. 
Published: January 2004

AbstractRestructuring and optimization of the conventional fermentation industry for fuel and chemical production is necessary to replace petrochemical production routes. Guided by this concept, a novel biorefinery process has been developed as an alternative to conventional upstream processing routes, leading to the production of a generic fermentation feedstock from wheat. The robustness of Aspergillus awamori as enzyme producer is exploited in a continuous fungal fermentation on whole wheat flour. Vital gluten is extracted as an added‐value byproduct by the conventional Martin process from a fraction of the overall wheat used. Enzymatic hydrolysis of gluten‐free flour by the enzyme complex produced by A. awamori during fermentation produces a liquid stream rich in glucose (320 g/L). Autolysis of fungal cells produces a micronutrient‐rich solution similar to yeast extract (1.6 g/L nitrogen, 0.5 g/L phosphorus). The case‐specific combination of these two liquid streams can provide a nutrient‐complete fermentation medium for a spectrum of microbial bioconversions for the production of such chemicals as organic acids, amino acids, bioethanol, glycerol, solvents, and microbial biodegradable plastics. Preliminary economic analysis has shown that the operating cost required to produce the feedstock is dependent on the plant capacity, cereal market price, presence and market value of added‐value byproducts, labor costs, and mode of processing (batch or continuous). Integration of this process in an existing fermentation plant could lead to the production of a generic feedstock at an operating cost lower than the market price of glucose syrup (90% to 99% glucose) in the EU, provided that the plant capacity exceeds 410 m3/day. Further process improvements are also suggested. © 2004 Wiley Periodicals, Inc.