bluuebunny/crossref_metadata_2025_split huggingface dataset:
Probing the Hydrogen Bonding Structure in the Rieske Protein
Authors: El Khoury Youssef , Trivella Aurélien , Gross Julien , Hellwig Petra 
Published: August 2010

AbstractThe use of the far‐infrared spectral range presents a novel approach for analysis of the hydrogen bonding in proteins. Here it is presented for the analysis of FeS vibrations (500–200 cm−1) and of the intra‐ and intermolecular hydrogen bonding signature (300–50 cm−1) in the Rieske protein from Thermus thermophilus as a function of temperature and pH. Three pH values were adequately chosen in order to study all the possible protonation states of the coordinating histidines. The FeS vibrations showed pH‐dependent shifts in the FIR spectra in line with the change of protonation state of the histidines coordinating the [2Fe2S] cluster. Measurements of the low‐frequency signals between 300 and 30 K demonstrated the presence of a distinct overall hydrogen bonding network and a more rigid structure for a pH higher than 10. To further support the analysis, the redox‐dependent shifts of the secondary structure were investigated by means of an electrochemically induced FTIR difference spectroscopic approach in the mid infrared. The results confirmed a clear pH dependency and an influence of the immediate environment of the cluster on the secondary structure. The results support the hypothesis that structure‐mediated changes in the environment of ironsulfur centers play a critical role in regulating enzymatic catalysis. The data point towards the role of the overall internal hydrogen bonding organization for the geometry and the electronic properties of the cluster.
Aspects of the Atmospheric Chemistry of Amides
Authors: Barnes Ian , Solignac Geraldine , Mellouki Abdelwahid , Becker Karl H. 
Published: August 2010

AbstractThe gas‐phase reactions of six amides, formamide, N‐methyl formamide, N,N‐dimethyl formamide, acetamide, N‐methyl acetamide and N,N‐dimethyl acetamide with the atmospheric oxidants OH radicals and Cl atoms, but in a number of cases also with NO3 radicals and ozone, are presented and discussed. Kinetic and mechanistic information available from previous experimental work is combined with new kinetic and product information from this study, obtained in a photoreactor using in situ FTIR spectrometry, to elucidate the gas‐phase photooxidation mechanisms of the amides and assess potential environmental implications.
Efficient Platinum‐Free Counter Electrodes for Dye‐Sensitized Solar Cell Applications
Authors: Ahmad Shahzada , Yum Jun‐Ho , Butt Hans‐Jürgen , Nazeeruddin Mohammad K. , Grätzel Michael 
Published: August 2010

AbstractNanoporous layers of poly(3,4‐propylenedioxythiophene) (PProDOT) were fabricated by electrical‐field‐assisted growth using hydrophobic ionic liquids as the growing medium. A series of PProDoT layers was prepared with three different ionic liquids to control the microstructure and electrochemical properties of the resulting dye‐sensitized solar cells, which were highly efficient and showed a power conversion efficiency of >9 % under different sunlight intensities. The current–voltage characteristics of the counter electrodes varied depending on the ionic liquids used in the synthesis of PProDOT. The most hydrophobic ionic liquids exhibited high catalytic properties, thus resulting in high power conversion efficiency and allowing the fabrication of platinum‐free, stable, flexible, and cost‐effective dye‐sensitized solar cells.
Effect of rapid thermal annealing on Zn1‐xCdxO layers grown by radio‐frequency magnetron co‐sputtering
Authors: Yu J. H. , Kim J. H. , Park D. S. , Jeong T. S. , Youn C. J. , Hong K. J. 
Published: August 2010

AbstractZn1‐xCdxO layers were deposited on the sapphire substrate using the radio‐frequency magnetron co‐sputtering system. The grown Zn1‐xCdxO layers were carried out in the post‐annealing treatment for 1 min at the 800 °C oxygen‐ambient by the rapid thermal annealing (RTA) method. X‐ray diffraction (XRD) experiment shows that the Zn1‐xCdxO layers are changed from the single phase of the hexagonal structure at 0≤x ≤0.08 to the double phase of hexagonal‐and‐cubic structure at x =0.13. Thus, the maximum Cd‐composition ratio with the hexagonal structure was found out to be x =0.08. Also, the crystallinity of Zn1‐xCdxO layers at x =0.13 was remarkably improved by the RTA annealing treatment. This crystal quality improvement was thought to be associated with the relaxation of the compressive strain remaining in the Zn1‐xCdxO layers. Therefore, the results of XRD and transmittance lead that the crystal quality of the Zn1‐xCdxO layers forming the hexagonal ZnO phase is better than that forming the cubic CdO phase. Consequently, the reliable formation and the crystallinity of the Zn1‐xCdxO layers were achieved by using the RTA method of short‐time thermal‐annealing at the high temperature. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An Alternative Solvent‐Free Synthesis of Nopinone under Ball‐Milling Conditions: Investigation of Reaction Parameters
Authors: Szuppa Tony , Stolle Achim , Ondruschka Bernd , Hopfe Wieland 
Published: August 2010

AbstractA new method for the oxidative cleavage of β‐pinene (1) yielding nopinone (2) with potassium permanganate as oxidant under solvent‐free conditions was established. The reaction was performed in a conventional ball mill with use of a grinding auxiliary. The auxiliary has the ability to sorb liquid reactants such as 1 on its surface to make liquid(s) accessible for mechanical impact. Different reaction parameters and technical variables were assessed concerning their influence on yield and selectivity of 2. Different chemical parameters such as oxidants, grinding auxiliaries, and quantities were investigated. Also tuning parameters including milling time, rotation frequency, and number of milling balls were explored.
Fast‐squarer circuits using 3‐bit‐scan without overlapping bits
Authors: Perri Stefania , Corsonello Pasquale 
Published: August 2010

AbstractThis paper presents a novel technique to design fast‐squaring circuits. The proposed approach speeds up squaring operations combining the 3‐bit scan without overlapping bits and the folding technique.Several hardware implementations of squarer circuits designed as described here are characterized for several operand wordlengths. Obtained results demonstrate that, using the ST 90 nm 1V CMOS technology, a 32‐bit squarer exploiting the novel way of generating partial products reaches a 769 MHz running frequency, dissipates less than 19.3 mW on average and occupies ∼91 000µm2of silicon area. Copyright © 2010 John Wiley & Sons, Ltd.
Encapsulated apocrine papillary carcinoma of the breast: Case report with clinicopathologic and immunohistochemical study
Authors: Laforga J. B. , Gasent J. M. , Sánchez I. 
Published: August 2010

AbstractWe describe a case of encapsulated papillary carcinoma (EPC), apocrine variant in a 50‐year‐old woman. The patient presented a cystic lesion in her right breast, measuring 8 cm in diameter, containing three solid papillary nodules. A fine‐needle aspiration showed isolated apocrine cells containing round nuclei, irregular nuclear membranes, fine chromatin, and prominent macronucleoli. The lesion was excised and showed a pure papillary apocrine carcinoma, which stained diffusely with GCDFP‐15 and androgen receptors. The lesion was totally devoid of myoepithelial cells (smooth muscle actyn, p63, calponin, and collagen IV stains were negative). With MIB1 the proliferative activity was 10%. To the best of our knowledge, this is the first report of EPC apocrine variant with cytologic and immunohistochemical study. This lesion must be included in the list of apocrine lesions of the breast. Diagn. Cytopathol. 2010. © 2010 Wiley‐Liss, Inc.
Anti‐anxiety and sedative profile evaluation of imidazo[1,2‐a]pyridine derivatives
Authors: López‐Martínez Margarita , Salgado‐Zamora Héctor , San‐Juan Eduardo Ramírez , Zamudio Sergio , Picazo Ofir , Campos Maria Elena , Naranjo‐Rodriguez Elia B. 
Published: August 2010

AbstractThree imidazo[1,2‐a]pyridine‐3‐nitrosated (L‐1, L‐2, L‐3) and a 3‐formyl imidazo[1,2‐a]pyridine thiosemicarbazone (L‐4) were synthesized and evaluated for their effects in the elevated plus maze, burying behavior test, rotarod performance, the horizontal wire test, and locomotor activity. L‐2 and L‐3 increased the percent time spent in the open arms of the plus maze at doses of 1 and 2 mg/kg without modifying the number of total entries. In addition, L‐2 and L‐3 (1 mg/kg) increased the number of open arm entries indicating anxiolytic‐like activity at this dose. In the burying behavioral test, L‐1 (2–8 mg/kg), L‐2 (8 mg/kg), and L‐3 (4 and 8 mg/kg), induced a clear reduction in cumulative burying behavior, without modifying burying behavior latency, thus reducing experimental anxiety. In the rotarod test, L‐1 and L‐2 impaired rotarod performance only at the highest evaluated dose (64 mg/kg) at which reduction of motor activity was observed and thereby no conclusions about myorelaxant effects can be proposed. All compounds showed a clear sedative effect and corresponding ED50values were obtained. Results indicate that compounds L‐1, L‐2, and L‐3 show a sedative and an anxiolytic profile. Drug Dev Res 71:371–381, 2010. © 2010 Wiley‐Liss, Inc.
Cognitive dysfunction in patients with type 2 diabetes
Authors: Reijmer Yael D. , van den Berg Esther , Ruis Carla , Jaap Kappelle L. , Biessels Geert Jan 
Published: August 2010

AbstractPeople with diabetes mellitus are at increased risk of cognitive dysfunction and dementia. This review explores the nature and severity of cognitive changes in patients with type 2 diabetes. Possible risk factors such as hypo‐ and hyperglycemia, vascular risk factors, micro‐ and macrovascular complications, depression and genetic factors will be examined, as well as findings from brain imaging and autopsy studies. We will show that type 2 diabetes is associated with modest cognitive decrements in non‐demented patients that evolve only slowly over time, but also with an increased risk of more severe cognitive deficits and dementia. There is a dissociation between these two ‘types’ of cognitive dysfunction with regard to affected age groups and course of development. Therefore, we hypothesize that the mild and severe cognitive deficits observed in patients with type 2 diabetes reflect separate processes, possibly with different risk factors and aetiologies. Copyright © 2010 John Wiley & Sons, Ltd.
Endothelial cell migration during murine yolk sac vascular remodeling occurs by means of a rac1 and FAK activation pathway in vivo
Authors: Enciso Josephine M. , Konecny Christine M. , Karpen Heidi E. , Hirschi Karen K. 
Published: August 2010

AbstractThe molecular mechanism(s) controlling cell migration during vascular morphogenesis in vivo remain largely undefined. To address this within a physiological context, we used retinaldehyde dehydrogenase‐2 (Raldh2) null mouse embryos and demonstrate that retinoic acid (RA) deficiency results in abnormal yolk sac vascular remodeling due to decreased Rac1 activation, increased RhoA activation, and increased focal adhesions. Vinculin was increased in Raldh2−/− yolk sacs, and molecular events important for focal adhesion turnover, FAK phosphorylation (Tyr397) and FAK‐paxillin association, were decreased. RA‐rescue of vascular remodeling down‐regulated vinculin and restored FAK phosphorylation (Tyr397) and FAK‐paxillin association. Furthermore, vascular rescue with vascular endothelial growth factor‐A, Indian hedgehog, and basic fibroblast growth factor restored FAK phosphorylation (Tyr397) in the endothelium of Raldh2−/− yolk sacs. Our results provide new insights into the regulation of endothelial cell migration during vascular remodeling in vivo by adding the Rac1 and FAK activation pathway as a critical mediator of focal adhesion formation and turnover during vascular remodeling. Developmental Dynamics 239:2570–2583, 2010. © 2010 Wiley‐Liss, Inc.
Organogenesis and tumorigenesis: Insight from the JAK/STAT pathway in the Drosophila eye
Authors: Wang Ying‐Hsuan , Huang Min‐Lang 
Published: August 2010

AbstractThe Janus kinase (JAK) signal transducer and activator of transcription (STAT) pathway is one of the main signaling pathways in eukaryotic cells. This pathway is used during diverse growth and developmental processes in multiple tissues to control cell proliferation, differentiation, survival, and apoptosis. In addition to its role during development, the JAK/STAT pathway has also been implicated in tumorigenesis. Drosophila melanogaster is a powerful genetic tool, and its eyes have been used extensively as a platform to study signaling pathways. Many reports have demonstrated that the JAK/STAT pathway plays pleiotropic roles in Drosophila eye development. Its functions and activation are decided by its interplay with other signal pathways and the epigenetic status. In this review, we focus on the functions and regulation of the JAK/STAT pathway during eye development and provide some insights into the study of this pathway in tumorigenesis. Developmental Dynamics 239:2522–2533, 2010. © 2010 Wiley‐Liss, Inc.
Protein tyrosine kinase 2 beta (PTK2B), but not focal adhesion kinase (FAK), is expressed in a sexually dimorphic pattern in developing mouse gonads
Authors: Beverdam Annemiek , Svingen Terje , Bagheri‐Fam Stefan , McClive Peter , Sinclair Andrew H. , Harley Vincent R. , Koopman Peter 
Published: August 2010

AbstractSexual reproduction is essential for the propagation and the maintenance of fitness of our species, and is dependent on the correct development of the bipotential genital ridges into testes and ovaries. Although several transcription factors, secreted signaling molecules, and their receptors have been found to be important for testis determination and early gonad development, comparatively little research has been carried out into intracellular signal transduction pathways activated during these processes. Focal adhesion kinase (FAK) and protein tyrosine kinase 2 beta (PTK2B) form one group of cytosolic tyrosine kinases that are known to be important for processes such as cell proliferation, differentiation, and motility. Here, we describe the temporal and spatial expression patterns of Fak and Ptk2b mRNA and protein during sex determination and early gonadogenesis in mouse embryos. Ptk2b mRNA and PTK2B protein were expressed in testes from 11.5 days post coitum onward, predominantly in developing Sertoli cells, in a SOX9‐dependent manner. Fak mRNA and FAK protein were expressed in gonads of both sexes at all stages examined. Our data suggest cell type‐ and stage‐specific roles for PTK2B during early testis development. Developmental Dynamics 239:2735–2741, 2010. © 2010 Wiley‐Liss, Inc.
Conservation, expression, and knockdown of zebrafish plxnb2a and plxnb2b
Authors: Perälä Nina , Peitsaro Nina , Sundvik Maria , Koivula Henri , Sainio Kirsi , Sariola Hannu , Panula Pertti , Immonen Tiina 
Published: August 2010

AbstractIn mice lacking Plexin B2, a receptor of the axon guidance molecules Semaphorin 4C and Semaphorin 4D, the closure of the neural tube and structural organization of the cerebellum are severely impaired. We cloned two Plexin B2 orthologs, plxnb2a and plxnb2b, in zebrafish, which is a widely used model for the development of the vertebrate central nervous system (CNS). The predicted proteins, Plexin B2a and Plexin B2b, contain all the conserved and functional domains of the plexin B‐subfamily. During embryonic development, plxnb2a is expressed, e.g., in pharyngeal arches while plxnb2b expression is more confined to neuronal structures like the cerebellum. However, both plxnb2a and plxnb2b are expressed at the midbrain–hindbrain boundary, in the otic vesicles, facial ganglia, and pectoral fins. Knockdown of both plxnb2a and plxnb2b simultaneously (>95% and 45%, respectively) resulted in normal CNS structure, axon guidance and swimming performance of the morphants. Developmental Dynamics 239:2722–2734, 2010. © 2010 Wiley‐Liss, Inc.
Zebrafish cx30.3: Identification and characterization of a gap junction gene highly expressed in the skin
Authors: Tao Liang , DeRosa Adam M. , White Thomas W. , Valdimarsson Gunnar 
Published: August 2010

AbstractWe have identified and characterized a zebrafish connexin, Cx30.3. Sequence similarity analyses suggested that Cx30.3 was orthologous to both mammalian Cx26 and Cx30, known to play important roles in the skin and inner ear of mammals. Analysis of mRNA expression showed that Cx30.3 was present in early embryos, and was highly abundant in skin, but also detected in other tissues including fins, inner ear, heart, and the retina. Injection of Cx30.3 cRNA into Xenopus oocytes elicited robust intercellular coupling with voltage gating sensitivity similar to mammalian Cx26 and Cx30. The similarities in functional properties and expression patterns suggest that Cx30.3, like mammalian Cx26 and Cx30, may play a significant role in skin development, hearing, and balance in zebrafish. Thus, zebrafish could potentially serve as an excellent model to study disorders of the skin and deafness that result from human connexin mutations. Developmental Dynamics 239:2627–2636, 2010. © 2010 Wiley‐Liss, Inc.
A transgenic zebrafish for monitoring in vivo microtubule structures
Authors: Asakawa Kazuhide , Kawakami Koichi 
Published: August 2010

AbstractThe microtubule (MT) cytoskeleton plays crucial roles in brain development by regulating the proliferation of neuronal progenitor cells, neuronal migration and axon guidance. Methods for monitoring MT in the intact brain, however, have been limited in vertebrates. Here, we report a transgenic zebrafish line for monitoring MT in vivo. This reporter line carries a transgene encoding the green fluorescent protein (GFP) ‐tagged tubulin gene linked to the upstream activating sequence (UAS), the recognition sequence of the yeast Gal4 transcriptional activator. By crossing this reporter line with appropriate transgenic Gal4 driver lines, we induced the GFP‐tagged tubulin in various cell types from the embryonic stages to the adult stage. In larvae expressing the modified tubulin, individual MT filaments and other MT structures, including the mitotic spindles in proliferating neuronal progenitor cells, were clearly visualized. Therefore, the transgenic UAS reporter line should be useful for directly monitoring MTs in the intact brain. Developmental Dynamics 239:2695–2699, 2010. © 2010 Wiley‐Liss, Inc.
Developmental expression of sideroflexin family genes in Xenopus embryos
Authors: Li Xiaojing , Han Dandan , Kin Ting Kam Richard , Guo Xiaogang , Chen Miao , Yang Yong , Zhao Hui , Chen Yonglong 
Published: August 2010

AbstractEmerging evidence indicates that mitochondrial carriers are not only crucial for metabolism, but also important for embryonic development. Sideroflexin is a novel family of mitochondrial tricarboxylate carrier proteins, of which the in vivo function is largely unknown. Here, we report on the expression patterns of five sideroflexin genes in Xenopus embryos. Whole‐mount in situ hybridization analysis reveals that while sideroflexin2 is expressed in the pancreas, sideroflexin1 and 3 display a complex expression in the central nervous system, somites, pronephros, liver, and pancreas. In contrast, only a weak expression of sideroflexin4 and 5 was detected in embryonic brain. Taken together, the five sideroflexin genes show both overlapping and nonoverlapping expression during Xenopus embryogenesis. As the primary structures of the five sideroflexin proteins are also quite similar, their functional redundancy should be taken into consideration for gene targeting studies. Developmental Dynamics 239:2742–2747, 2010. © 2010 Wiley‐Liss, Inc.
Analysis of a Hand1 hypomorphic allele reveals a critical threshold for embryonic viability
Authors: Firulli Beth A. , McConville David P. , Byers III James S. , Vincentz Joshua W. , Barnes Ralston M. , Firulli Anthony B. 
Published: August 2010

AbstractLoss‐of‐function analysis of the basic helix–loop–helix (bHLH) transcription factor Hand1 indicates critical roles in development. In an effort to generate a Hand1 cDNA knock‐in reporter mouse, we generated two hypomorphic alleles, which extend embryonic survival to between embryonic day (E) 10.5 and E12.5. Heart morphogenesis appears largely normal; however, hypomorphic mice display thin left ventricular myocardium and reduction in pharyngeal mesoderm. Caudal defects, large allantois, and thickened yolk sac are observed and consistent with systemic Hand1 gene deletion. Hand1 mRNA is expressed at 30% of wild‐type littermates and known Hand1‐dependent genes show intermediate expression compared with wild‐type and Hand1 null mice. Interestingly, putative bHLH partners, Hand2 and Twist1, show altered expression in both Hand1 null and hypomorphic backgrounds and intercrossing the Hand1 hypomorphic mice onto the Hand2 systemic null background exacerbates the cardiac and lateral mesoderm phenotypes. Together, these data define a critical threshold of Hand1 expression that is necessary for embryonic survival. Developmental Dynamics 239:2748–2760, 2010. © 2010 Wiley‐Liss, Inc.
Autotaxin controls caudal diencephalon‐mesencephalon development in the chick
Authors: Ohuchi Hideyo , Fukui Hitomi , Matsuyo Akane , Tomonari Sayuri , Tanaka Masayuki , Arai Hiroyuki , Noji Sumihare , Aoki Junken 
Published: August 2010

AbstractThe diencephalon is the embryonic anlagen of the higher integration centers of the brain. Recent studies have elucidated how the cells in the rostral diencephalon acquire their regional identities. However, the understanding of the mechanisms under which the caudal diencephalon is formed is still limited. Here we focus on the role of Autotaxin (ATX), a lysophospholipid‐generating exoenzyme, whose mRNA is detected in the caudal diencephalon. RNA interference against ATX altered the expression pattern of Pax6‐regualted genes, Tcf4, Lim1, and En1, implying that ATX is required for the maintenance of the regional identity of the caudal diencephalon and the diencephalon‐mesencephalon boundary (DMB). Furthermore, ATX‐RNAi inhibited neuroepithelial cell proliferation on both sides of the DMB. We propose a dual role of ATX in chick brain development, in which ATX not only contributes to the formation of caudal diencephalon as a short‐range signal, but also regulates the growth of mesencephalon as a long‐range signal. Developmental Dynamics 239:2647–2658, 2010. © 2010 Wiley‐Liss, Inc.
The ziwi promoter drives germline‐specific gene expression in zebrafish
Authors: Leu David H. , Draper Bruce W. 
Published: August 2010

AbstractWe describe here the characterization of the promoter activity of a 4.8‐kb sequence isolated from the 5′ end of the zebrafish germ cell‐specific ziwi gene. We show that this fragment is sufficient to drive heterologous gene expression specifically in germ cell starting as early as 7 days post‐fertilization, a time point when only mitotic germ cells are present in the gonad. In adult animals, we find that this fragment is sufficient to drive gene expression in all germ cells with stage‐specific differences in expression levels. In females, EGFP expression is highest in stage IB oocytes, but appreciable expression is detected in both pre‐meiotic germ cells, as well stage II–IV oocytes and mature eggs. In males, EGFP expression is highest in spermatogonial stem cells, but low levels are detected in all stages, including spermatozoa. Developmental Dynamics 239:2714–2721, 2010. © 2010 Wiley‐Liss, Inc.