bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression analyses of zebrafish transferrin, ifabp, and elastaseB mRNAs as differentiation markers for the three major endodermal organs: Liver, intestine, and exocrine pancreas
Authors: Mudumana Sudha Puttur , Wan Haiyan , Singh Malkeet , Korzh Vladimir , Gong Zhiyuan 
Published: April 2004

AbstractIn the present work, three zebrafish cDNA clones encoding transferrin, intestinal fatty acid binding protein (IFABP), and elastaseB were cloned and their expression patterns in early zebrafish development were characterized as differentiation markers for the three major endoderm organs: liver, intestine, and exocrine pancreas. transferrin and ifabp mRNAs exhibit a biphasic expression pattern during early development. transferrin mRNAs were first expressed at ∼7 hours postfertilization (hpf) in the yolk syncytial layer (YSL) and later in the liver rudiment (from ∼48 hpf) and in the esophagus transiently (72–96 hpf). Ifabp mRNAs were initially expressed in the YSL at the ventral side during late epiboly (8–9 hpf), spread throughout the YSL of later stage embryos, and appeared in the intestine rudiment at ∼36 hpf. In contrast to the transferrin and ifabp mRNAs, elastaseB mRNAs were not expressed in the yolk sac or YSL, and these transcripts were detected exclusively in the exocrine pancreas after ∼56 hpf. Developmental Dynamics 230:165–173, 2004. © 2004 Wiley‐Liss, Inc.
Expression patterns of nectins and afadin during epithelial remodeling in the mouse embryo
Authors: Okabe Noriko , Ozaki‐Kuroda Kumi , Nakanishi Hiroyuki , Shimizu Kazuya , Takai Yoshimi 
Published: April 2004

AbstractCell–cell adhesion plays key roles in tissue morphogenesis and organogenesis. Nectins are Ca2+‐independent immunoglobulin‐like cell adhesion molecules connected to the actin cytoskeleton through afadin. Nectins play roles in a variety of cell–cell junctions in cooperation with or independently of cadherins. Here, we examined the cellular localization of nectins and afadin throughout primitive streak, neural plate, and early organogenesis stages of mouse development. Nectin and afadin localization coincided with a honeycomb‐shaped meshwork of actin filaments at adherens junctions of polarized epithelia, including neuroepithelium, epithelial somites, and facial primordia. As organogenesis progressed, nectin‐2 expression was maintained in general columnar epithelia, whereas nectin‐1 and ‐3 became highly concentrated at sites of neural morphogenesis. Moreover, nectin‐1 was highly expressed in keratinocytes of the skin, developing hair follicles, and epithelium of developing teeth. These results suggest that nectins and afadin are involved in dynamic epithelial remodeling during mouse development. Developmental Dynamics 230:174–186, 2004. © 2004 Wiley‐Liss, Inc.
Identification, cloning and expression analysis of the pluripotency promoting Nanog genes in mouse and human
Authors: Hart Adam H. , Hartley Lynne , Ibrahim Marilyn , Robb Lorraine 
Published: April 2004

AbstractThe murine Nanog gene, a member of the homeobox family of DNA binding transcription factors, has been shown recently to maintain pluripotency of embryonic stem cells. We have used a sequence homology and expression screen to identify and clone the mouse and human Nanog genes and characterized their phylogenetic context and expression patterns. We report here the gene structure and expression patterns of the mouse Nanog gene, the human Nanog and Nanog2 genes, and six processed human Nanog pseudogenes. Mouse Nanog expression is high in undifferentiated embryonic stem cells and is down‐regulated during embryonic stem cell differentiation, concomitant with loss of pluripotency. Murine embryonic Nanog expression is detected in the inner cell mass of the blastocyst. After implantation, Nanog is detectable at embryonic day (E) 6 in proximal epiblast in the region of the presumptive primitive streak. Expression extends distally as the streak elongates during gastrulation and remains restricted to epiblast. Nanog RNA is down‐regulated in cells ingressing through the streak to form mesoderm and definitive endoderm. Nanog expression also marks the pluripotent germ cells of the nascent gonad at E11.5–E12.5 and is highly expressed in germ cell tumour and teratoma‐derived cell lines. Reverse transcriptase‐polymerase chain reaction analysis detected mouse Nanog expression at low levels in several adult tissues. The human Nanog genes are expressed in embryonic stem cells and down‐regulated in all adult tissues and differentiated cell lines examined. High levels of human Nanog expression were detected by Northern analysis in the undifferentiated N‐Tera embryonal carcinoma cell line. The conservation in gene sequence, structure, and expression of mouse and human Nanog and Nanog2 genes may reflect a common role in the maintenance of pluripotency in both species. Developmental Dynamics 230:187–198, 2004. © 2004 Wiley‐Liss, Inc.
Structure, Bonding, and Tyrosinase‐Like Reactivity of Copper Complexes Coordinated by Mononucleating Tridentate N−O−N Type Ligands
Authors: Cheng Yen‐Ting , Chen Hsiao‐Lan , Tsai Shiou‐Yuan , Su Chan‐Cheng , Tsang Huan‐Sheng , Kuo Ting‐Shen , Tsai Yi‐Chou , Liao Fen‐Ling , Wang Sue‐Lein 
Published: April 2004

AbstractCopper complexes with mononucleating tridentate ligands of the N−O−N type, including 1,3‐bis(benzimidazol‐2‐yl)‐2‐oxapropane (bbmo), 1,3‐bis(N‐methylbenzimidazol‐2‐yl)‐2‐oxapropane (bbMemo), 1,3‐bis(N‐n‐propylbenzimidazol‐2‐yl)‐2‐oxapropane (bbPrmo), and 1,3‐bis(pyrid‐2‐yl)‐2‐oxapropane (bpmo), were tested for the oxygenation of phenols. Mixed ligand copper complexes of [Cu(N−O−N)(N−N)](ClO4)2, where N−N denotes 2,2′‐bipyridine (bipy), 1,10‐phenanthroline (phen), ethylenediamine (en), and/or N,N,N′,N′‐tetramethylethylenediammine (tmen), were prepared and characterized by elemental analyses, and electronic, vibrational, and epr spectroscopic measurements. The molecular structures of fac‐[Cu(bbMemo)(bipy)(H2O)](ClO4)2(H2O) (1a), fac‐[Cu(bbMemo)(phen)](ClO4)2(CH3CN) (4a), fac‐[Cu(bbPrmo)(phen)](ClO4)2 (5a), and fac‐[Cu(bpmo)(bipy)(ClO4)](ClO4) (7a) were determined by X‐ray diffraction methods. The structures of these complexes are square pyramids or elongated octahedra with the heterocycle nuclei forming the basal or equatorial planes. The terminal heterocycles of the facially coordinated tridentate ligands are nearly perpendicular to the basal or equatorial planes. Similar structures are proposed for the remaining complexes, based on spectroscopic data. Both stoichiometric and catalytic oxidation reactions of 2,4‐di‐tert‐butylphenol and 2,4‐di‐tert‐butylphenolate with dioxygen adducts of [Cu(bbPrmo)]+ at room temperature afforded 3,3′,5,5′‐tetra‐tert‐butyl‐2,2′‐biphenol and 3,5‐di‐tert‐butyl‐o‐quinone. Similar reactions with the dioxygen adduct of [Cu(bpmo)]+ yielded only 3,3′,5,5′‐tetra‐tert‐butyl‐2,2′‐biphenol. In light of the tyrosinase‐like reactivity, the possible intermediates, [(bbPrmo)2Cu2(μ‐η2:η2‐peroxo)]2+, [(bbPrmo)2Cu2(μ‐oxo)2]2+, and [(bpmo)2Cu2(μ‐oxo)2]2+ are proposed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Properties of Organometallic Sulfur‐Rich Dithiolate Complexes [M(L)(C8H4S8)] (M = RhIII and IrIII; L = η5‐C5H5 and η5‐C5Me5) and Their Oxidation
Authors: Kawabata Kazuhiro , Nakano Motohiro , Tamura Hatsue , Matsubayashi Gen‐etsu 
Published: April 2004

Abstract[Rh(η5‐C5H5)(C8H4S8)] and [M(η5‐C5Me5)(C8H4S8)] [M = RhIII and IrIII. C8H4S82− = 2‐{(4,5‐ethylenedithio)‐1,3‐dithiole‐2‐ylidene}‐1,3‐dithiole‐4,5‐dithiolate(2−)] were prepared by reactions of [NMe4]2[C8H4S8] with [Rh(η5‐C5H5)Cl2]2 or [M(η5‐C5Me5)Cl2]2 (M = Rh and Ir). They exhibit oxidation potentials of between +0.16 and +0.24 V (versus Ag/Ag+) with oxidation of the dithiolate ligand. The geometries and electronic states of their one‐electron‐oxidized species [M(L)(C8H4S8)]+ and [RhX(L)(C8H4S8)] (M = Rh and Ir; X = Br and I; L = η5‐C5H5 and η5‐C5Me5), obtained by reactions of the above complexes with bromine, iodine, or the ferrocenium cation are discussed based on their ESR spectra. The oxidized η5‐C5Me5‐metal complexes exhibit electrical conductivities of between 10−6 and 10−4 S cm−1, while some oxidized η5‐C5H5‐Rh complexes show conductivities of between 10−3 and 10−2 S cm−1 measured for compacted pellets at room temperature. The X‐ray crystal structures of the two‐electron‐oxidized species [MI(η5‐C5Me5)(C8H4S8)](I3) (M = Rh and Ir) were also clarified. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Anchoring of Copper(II) Acetylacetonate onto an Activated Carbon Functionalised with a Triamine
Authors: Silva Ana Rosa , Martins Magda , Freitas M. Madalena A. , Figueiredo José Luís , Freire Cristina , de Castro Baltazar 
Published: April 2004

AbstractCopper(II) acetylacetonate was anchored onto a triamine functionalised activated carbon by Schiff condensation using a four‐step procedure: (i) oxidation of activated carbon with nitric acid; (ii) treatment with thionyl chloride to convert carbon surface carboxylic acids into acyl chlorides; (iii) condensation of acyl chloride functionalities with amine groups of bis(3‐aminopropyl)amine (trien); and (iv) Schiff condensation between free amine groups of bound trien with the oxygen atoms of acetylacetonate coordinated to the copper(II) ion. The same complex was also anchored to the unmodified activated carbon and to the acyl chloride functionalised carbon prepared in (ii). The resulting carbon‐based materials were characterised by elemental analysis, surface techniques (SEM and XPS), temperature programmed desorption, and nitrogen adsorption at 77 K and EPR spectroscopy for the materials with copper(II) complexes. Data from all techniques provided evidence for (i) the covalent binding of trien to acyl chloride functionalities; and (ii) the irreversible attachment of [Cu(acac)2] to all carbon‐based materials. Data for the materials with copper(II) proved conclusively that only the immobilisation procedure based on Schiff condensation with trien led to copper(II) complexes in which the metal centre remains four‐coordinate. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Self‐Assembly of Novel Silver Polymers Based on Flexible Sulfonate Ligands
Authors: Sun Daofeng , Cao Rong , Bi Wenhua , Li Xiaoju , Wang Yanqin , Hong Maochun 
Published: April 2004

AbstractSelf‐assembly reactions of sulfonates with AgNO3 in the presence of secondary N‐ or P‐containing ligands result in the formation of four new silver‐sulfonate polymers, [Ag(PIP)]n·[Ag(pesp)]n·2nH2O (1), [Ag2(pesp)(dabco)]n·5nH2O (2), [{Ag(pesp)1/2(hmt)1/4}·0.5H2O]n (3) and [Ag(PPh3)(pesp)1/2]n·nMeOH (4), whose structures change from one‐dimensional chains to three‐dimensional open frameworks based on the secondary ligands. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Crystal Engineering of the Coordination Architecture of Metal Polycarboxylate Complexes by Hydrothermal Synthesis: Assembly and Characterization of Four Novel Cadmium Polycarboxylate Coordination Polymers Based on Mixed Ligands
Authors: Dai Jing‐Cao , Wu Xin‐Tao , Hu Sheng‐Min , Fu Zhi‐Yong , Zhang Jian‐Jun , Du Wen‐Xin , Zhang Han‐Hui , Sun Rui‐Qing 
Published: April 2004

AbstractFour novel compounds, [Cd(tp)(bpp)]n (1), [Cd(tp)(bpy)]n (2), [{Cd4(bpa)4(bpy)6}·(bpy)0.5·7H2O]n (3) and [Cd2{(Htp)(tp)1.5}(bpe)]n (4) [tp = terephthalate, bpp = 1,3‐bis(4‐pyridyl)propane, bpy = 4,4′‐ bipyridine, bpa = 4,4′‐biphenyldicarboxylate, bpe = 1,2‐bis(4‐pyridyl)ethane], of cadmium(II) polycarboxylate coordination polymers based on mixed ligands were obtained by a hydrothermal method. Complex 1 (C21H18CdN2O4) crystallizes in the orthorhombic Pbca space group [a = 11.9401(0) Å, b = 16.8148(3) Å, c = 20.2743(3) Å, and Z = 8]. Complex 2 (C18H12CdN2O4) belongs to the monoclinic C2/m space group [a = 20.299(3) Å, b = 10.720(1) Å, c = 11.764(2) Å, β = 110.944(2)°, and Z = 6]. Complex 3 (C121H98Cd4N13O23) belongs to the monoclinic P21/c space group [a = 23.2208(0) Å, b = 11.8103(1) Å, c = 45.4670(6) Å, β = 104.516(1)°, and Z = 4]. Complex 4 (C32H23Cd2N2O10) belongs to the monoclinic P21/n space group [a = 6.9896(1) Å, b = 22.6294(1) Å, c = 19.7738(3)Å, β = 99.380(1)°, and Z = 4].The CdII centers in the four compounds are bridged by mixed polycarboxylate ligands with bpy and related species to form the twofold parallel interpenetration topology of an undulating 2D 44 net for 1, a twofold interpenetration topology of a 3D α‐Po net for 2, a fourfold interpenetration topology of a 3D 5‐connected borazone 4664 net for 3 and an interesting 3D spiral pipe‐like structure with a bolt for 4. These four compounds exhibit strong fluorescent emissions at 549 and 582 nm (λex = 532 nm) for 1, 493 nm (λex = 360 nm) for 2, 413 and 424 nm (λex = 315 nm) for 3 and 350 nm (λex = 220 nm) for 4 in the solid state at room temperature. These are novel structural topologies and could be significant in the field of photoactive materials. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Bis(phosphane oxide) Adducts of Rh2(MTPA)4 — Kinetics and Chirality Discrimination
Authors: Gáti Tamás , Simon András , Tóth Gábor , Szmigielska Anna , Maj Anna M. , Pietrusiewicz K. Michał , Moeller Stefan , Magiera Damian , Duddeck Helmut 
Published: April 2004

AbstractThe symmetrical bis(phosphane oxide) 1 and its chiral derivatives 2 and 3 form a variety of adduct species with the dirhodium complex [Rh−Rh] which can be identified by low‐temperature 1H and 31P NMR spectroscopy by using varying [Rh−Rh]:ligand ratios. The asymmetric bis(phosphane oxide) 3 shows a distinct preference for binding through the Ph2P=O (Pa) as compared to the tBu(Ph)P=O (Pb) functionality due to the bulky tert‐butyl group. The chiral bis(phosphane oxides) 2 and 3 form complex mixtures of various adduct species. Nevertheless, it is possible to monitor enantiomeric compositions from various NMR signal duplications at 213 K and even at room temperature or slightly elevated temperatures. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis and Characterization of Homoleptic Lanthanide Guanidinate Complexes and Their Catalytic Activity for the Ring‐Opening Polymerization of Trimethylene Carbonate
Authors: Zhou Liying , Yao Yingming , Zhang Yong , Xue Mingqiang , Chen Jinglei , Shen Qi 
Published: April 2004

AbstractTwo methods to synthesize homoleptic guanidinate lanthanide complex are described. The samarium guanidinate complex [Sm{Ph2NC(NCy)2}3]·2C7H8 (1) can be synthesized by the metathesis reaction of lithium guanidinate with anhydrous samarium trichloride in a 3:1 molar ratio. The analogous complexes [Ln{Ph2NC(NCy)2}3]·2C7H8 [Ln = Yb (2), Nd (3)] can also be synthesized by the insertion reaction of N,N′‐dicyclohexylcarbodiimide into the Ln−N bond of [(THF)4Li][Ln(NPh2)4] in a 3:1 molar ratio in good yield. Complexes 1−3 were characterized by elemental analysis, IR and 1H NMR spectroscopy. The molecular structures of complexes 1 and 3 were further determined by X‐ray diffraction techniques. These complexes showed high activity for the ring‐opening polymerization of trimethylene carbonate (TMC), giving polymers with Mw/Mn ranging from 1.41−1.73. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Oxidative Addition of RX to Soluble and Polymer‐Bound Molybdenum Carbonyl Complexes
Authors: Heinze Katja , Jacob Volker , Feige Christian 
Published: April 2004

AbstractOxidative addition of PhSnCl3 or allyl halides to molybdenum tetracarbonyl complexes proceeds both in solution and on polymer matrices. The structures of the soluble MoII complexes have been determined by single‐crystal X‐ray diffraction in the solid state and by NMR and IR spectroscopy in solution. The identity and stability of the polymer‐bound complexes have been elucidated by spectroscopic techniques directly on the solid support and by releasing the complexes from the support. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
At‐line Determination of Glucose, Ammonia, and Acetate in High Cell Density Cultivations of Escherichia coli
Authors: Peuker T. , Riedel M. , Kaiser C. , Ellert A. , Lenz K. , Elsholz O. , Luttmann R. 
Published: April 2004

AbstractA sophisticated measurement system for at‐line determination of the main C‐source glucose, the by‐product acetate, and the N‐source ammonium for high cell density cultivations (HCDC) of Escherichia coli K12 TG1 is presented. One flow diffusion technique (FDA) system is used for glucose measurement in the range of 0.5 up to 40 gL–1 in the cultivation broth. Another FDA system detects the amount of the undesired by‐product acetate. The ammonium concentration in the range of 0.2 to 2.5 gL–1 is determined on‐line by a flow injection analysis (FIA) system. For verification purposes, an HPLC system which is also connected to the bioreactor for at‐line measurements is utilized. Several HCDC with cell densities of more than 100 gL–1 have been carried out. The courses of growth‐determining substrates have been detected at‐line. All used systems have shown an excellent compliance with off‐line measurements.
Applications of the Liquid Cyclone in Biological Separations
Authors: Ortega‐Rivas E. 
Published: April 2004

AbstractHydrocyclone technology has been suggested as a practical alternative in solid/liquid separations involving biological materials. This paper reviews applications of hydrocyclones in food processing, considering the non‐Newtonian nature of most suspensions treated in the food industry. The hydrocyclone is easy to install and operate, and requires very limited space. It represents an unsophisticated piece of equipment, which runs in a continuous manner and it can be operated at lower costs than most solid/liquid separation techniques. Hydrocyclones have been used in the food industry for the refining of starch, to separate gossypol from cottonseed protein in cottonseed oil processing, and for some other applications, such as multi‐stage mixer/separator extraction systems for soluble coffee. More recently, some other applications in biological systems, which will be discussed in this article, have also been tested.
Transgenic Tobacco Expressing Zephyranthes candida Agglutinin Showing Enhanced Resistance to Aphids
Authors: Pang Y. , Shen G. , Qi H. , Tan F. , Sun X. , Tang K. 
Published: April 2004

AbstractAphid is one of the most serious, sap‐sucking insect pests which cause significant losses of crop yields. The aim of this study is to investigate whether transgenic plants expressing Zephyranthes candida agglutinin (ZCA) could confer enhanced resistance to aphids. Tobacco was transformed with a plasmid, pCAMBIAZCA, containing the marker genes nptII and gusA and the Zephyranthes candida agglutinin gene (zca) via Agrobacterium tumefaciens‐mediated transformation. Twenty‐six independent transgenic plants were regenerated. Western blot analysis revealed ZCA expression at various levels in transgenic plants. Insect bioassay tests showed that transgenic plants expressing a high level of ZCA significantly inhibited the growth of the population of peach potato aphids (Myzus persicae Sulzer). This is the first report in which transgenic plants expressing ZCA conferred enhanced resistance to aphids. Our study suggests the zca gene could be a useful candidate for genetic engineering strategies in plants to provide aphid resistance.
Biofilm Growth and Bed Fluidization in a Fluidized Bed Reactor Packed with Support Materials of Low Density
Authors: Saucedo‐Terán R.A. , Ramírez‐Baca N. , Manzanares‐Papayanopoulos L. , Bautista‐Margulis R. , Nevárez‐Moorillón G.V. 
Published: April 2004

AbstractSupport materials of low‐density for fluidized bed reactors provide several operational advantages, including lower energy requirements and proper biofilm growth balance. The aim of this investigation was to study the extent of biofilm growth and bed fluidization in an experimental reactor, using polyester resin (ρpr = 1220 kg/m3) and vitrified expanded perlite (ρvep = 1710 kg/m3) as alternative support materials to conventional silica sand. A noteworthy amount of biofilm was observed to be attached to both support materials from the very beginning of the bioreactor operation. Nevertheless, there were significant variations in biofilm growth and activity over the course of the experimental trials. For both perlite and polyester beds, the highest biofilm mass and the highest total number of mesophilic bacteria were observed between the 7th and the 10th day, showing a steady state trend at the end of the experimental runs. The chemical oxygen demand (COD) removal levels were concomitant with biofilm mass and total mesophilic bacteria changes, although the polyester bed efficiency was slightly higher than that for the perlite bed. As expected, the polyester bed was fluidized at a lower re‐circulation flow compared to the perlite bed. Reactor back‐washing was not required for these support materials since biomass excess was adequately separated by means of a special internal device. The efficiencies of removal of organic matter achieved were acceptable (up to 78 %) despite the low volume of the support material (25 %) and the low hydraulic retention time (30 min).
Enzyme Production of Pleurotus ostreatus Evaluated by the Three‐Way Principal Component Analysis
Authors: Morais H. , Ramos C. , Forgacs E. , Jakab A. , Cserhati T. 
Published: April 2004

AbstractThe effect of the composition of culture media and fermentation time on the production of β‐glucosidase, xylanase, laccase, manganese‐dependent and independent peroxidases by the edible fungus Pleurotus ostreatus was determined. Culture medium separately containing potato, pepper, and tomato extracts and the enzyme activities were assessed to 31.5 days of fermentation. Three‐dimensional principal component analysis (3D‐PCA) followed by the plots of the first two elements of component matrices was employed for the elucidation of the similarities and dissimilarities between the parameters. It was established that the dimensionality of the original 3D matrix (9, 5, 4) could be reduced to 2, 1, 2 with 4.54 % loss of information. The plots demonstrated that the culture media displayed large differences in their capacity to promote enzyme production and that the presence of pepper and tomato extracts exerted the greatest influence on the enzyme activities. The effect of the fermentation time was manifested only after 14 d of fermentation and the highest differences were observed after 28 and 31.5 d of fermentation. Except laccase and manganese‐dependent peroxidase, the enzyme activities also differed considerably dependent on the composition of the fermentation broth. 3D‐PCA followed by the plots of component matrices is a valuable tool for the simultaneous assessment of three dimensional data matrices in biotechnological processes.