bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solvothermal Synthesis, Characterization, and Formation Mechanism of a Single‐Layer Anatase TiO2 Nanosheet with a Porous Structure
Authors: Chen Yajie , Tian Guohui , Ren Zhiyu , Tian Chungui , Pan Kai , Zhou Wei , Fu Honggang 
Published: December 2010

AbstractA novel single‐layer polycrystalline anatase TiO2 (SLP TiO2) nanosheet with porous structure was synthesized through a simple solvothermal method by employing rod‐like titanyl sulfate as the starting material in the presence of glycerol, followed by calcination. SEM, TEM, X‐ray diffraction, FTIR spectroscopy, thermogravimetry coupled to FTIR spectroscopy, solid‐state 13C NMR spectroscopy, and N2 adsorption/desorption processes were employed to investigate the structure of the products. The structure and morphology were found to be dependent on the experimental conditions, such as solvothermal reaction time, morphology of titanyl sulfate, and solvent type. The obtained SLP TiO2 nanosheet was employed as a support for loading well‐dispersed Ag nanoparticles and proved to be a good surface‐enhanced Raman scattering (SERS) substrate for the detection of 4‐aminothiophenol and Rhodamine 6G, showing great potential as a convenient and powerful substrate for SERS studies in the field of detecting different target molecules due to good uniformity and reliability.
New Access to and Reactions of P‐Functional Acylphosphane Complexes
Authors: Nesterov Vitaly , Duan Lili , Schnakenburg Gregor , Streubel Rainer 
Published: December 2010

AbstractP‐Functional (acylphosphane)tungsten complexes 4a–f have been prepared in good yields by the reaction of phosphinidenoid complexes 2a–d with acyl chlorides 3a,b. The reactions of acyl(chloro)phosphane complex 4a at –80 °C with organolithium reagents selectively led to the formation of lithiated phospha‐enolate complex 5b. The ambident reactivity of this compound was demonstrated in reactions with electrophiles such as PhC(O)Cl, MeI, and Me3SiCl, which yielded O‐substituted complexes 6a,b and 8a,b and P‐substituted complex 7.
Synthesis and Characterization of Highly Soluble Two‐Photon‐Absorbing Chromophores with Multi‐Branched and Dendritic Architectures
Authors: Lin Tzu‐Chau , Lin Wei‐Lun , Wang Chih‐Ming , Fu Chih‐Wei 
Published: December 2010

AbstractA set of novel multi‐polar compounds composed of four fluorene‐based derivatives with systematic alteration of the molecular structure was synthesized and their nonlinear optical properties in the femtosecond and nanosecond time domain were examined. Preliminary experimental results show that the two‐photon activities of the model compounds are connected to structural parameters, such as the number of peripheral electron‐donating groups and/or the size of the π‐domain in a dye molecule. It is also found that these model chromophores possess large nonlinear attenuation under the irradiation of laser pulses working at nanosecond regimes, indicating that these compounds may have strong two‐photon‐assisted excited‐state absorption within the studied spectral region. Effective optical‐power‐limiting behaviors of the dendritic fluorophores were also demonstrated to show that such dye molecules can be potential materials for use as broadband and rapid‐responsive optical limiters, especially against laser lights with longer pulses.
Synthesis and Biological Evaluation of 1‐Deoxy‐5‐hydroxysphingosine Derivatives
Authors: Esteve Judit , Lorente Adriana , Romea Pedro , Urpí Fèlix , Ríos‐Luci Carla , Padrón José M. 
Published: December 2010

AbstractA sequential transformation based on the titanium‐mediated aldol addition of (S)‐1‐bromo‐3‐(tert‐butyldimethylsilyloxy)‐2‐butanone, a chiral lactate‐derived ketone, to tetradecanal followed by reduction of the ensuing aldolate afforded the corresponding syn‐1,3‐diol as a single diastereomer. Debromination and further manipulation of this intermediate allowed the efficient synthesis of two enantiopure 1‐deoxy‐5‐hydroxysphingosines, which exhibit promising biological activity against a representative panel of human cancer lines.
Scope and Selectivity of Heterogeneous Rh0‐Catalyzed Tandem Dehydrocoupling/Hydrogenation Using Me2NH·BH3 as a Stoichiometric H2 Source
Authors: Sloan Matthew E. , Staubitz Anne , Lee Kajin , Manners Ian 
Published: December 2010

AbstractThe catalytic dehydrocoupling of Me2NH·BH3 (1) by Rh/Al2O3 (2) has been shown to act as an efficient hydrogenation and reduction system for a variety of organic substrates. A range of functional groups have been reduced, but chloro, bromo and iodo substituents, epoxide and nitrile groups were found to be stable under the reaction conditions, allowing chemoselective hydrogenation reactions to be performed. This reduction has also been shown to proceed cleanly under atmospheric air for a few representative examples of alkene and nitro functional groups.
Synthesis and Utility of 2‐Halo‐O6‐(benzotriazol‐1‐yl)‐Functionalized Purine Nucleosides
Authors: Devine Shane M. , Scammells Peter J. 
Published: December 2010

AbstractAn efficient synthesis of 2‐halo‐O6‐(benzotriazol‐1‐yl)‐substituted purine nucleosides has been accomplished via (benzotriazol‐1‐yloxy)tris(dimethylamino)phosphonium hexafluorophosphate (BOP)‐mediated coupling and subsequent halogenation via diazotization of the 2‐amino group of various protected guanosines and directly from guanosine itself. These products are amenable to substitution and coupling reactions in the 2‐ and 6‐positions and, accordingly, provide efficient access to highly functionalized purine nucleosides.
Electron‐Deficient Aryl β‐Diketones: Synthesis and Novel Tautomeric Preferences
Authors: Sloop Joseph C. , Boyle Paul D. , Fountain Augustus W. , Pearman William F. , Swann Jacob A. 
Published: December 2010

AbstractFluorinated aryl β‐diketones were prepared using Claisen and electrophilic fluorination methods. The keto–enol and enol–enol tautomerism of these compounds were examined in the solid state, as neat liquids and in polar, aprotic solution by crystallography and spectroscopy. Neat‐liquid spectroscopic measurements as well as single crystal X‐ray crystallographic results for selected electron‐deficient aryl β‐diketones suggest a single, chelated cis‐enol isomer that is conjugated with the aryl ring. In polar aprotic solvents, nonfluorinated aryl β‐diketones equilibrate rapidly from the chelated cis‐enol form to a tautomeric mixture of cis‐chelated enol and a substantial proportion of the diketone form, trifluoromethylated aryl β‐diketones show only limited equilibration from the chelated cis‐enol to the diketone form, with 2‐fluoro‐1‐aryl β‐diketones again displaying only the diketonic form.
Cyclization of 2‐Alkynylallyl Alcohols to Highly Substituted Furans by Gold(I)–Carbene Complexes
Authors: Hashmi A. Stephen K. , Häffner Tobias , Rudolph Matthias , Rominger Frank 
Published: December 2010

AbstractVarious 2‐alkynylallyl alcohols were synthesized by a generally applicable Sonogashira coupling protocol. Subsequent gold‐catalyzed transformation was investigated. The use of AuI catalysts bearing carbene ligands, of either the N‐heterocyclic carbene or nitrogen acyclic carbene type, delivered the desired products with low catalyst loadings and under very mild reaction conditions. A broad array of substrates was tested, including alkyl‐, alkenyl‐, and aryl‐substituted alkynes, as well as substrates with two alkynyl moieties. The methodology turned out to have a broad scope. Secondary allyl alcohols were also tolerated, and the resulting trisubstituted furans could be isolated in high yields.
Ruthenium‐Catalyzed Synthesis of 1,5‐Dichlorides by Sequential Intermolecular Kharasch Reactions (Eur. J. Org. Chem. 2/2011)
Authors: Thommes Katrin , Fernández‐Zúmel Mariano A. , Buron Charlotte , Godinat Aurélien , Scopelliti Rosario , Severin Kay 
Published: December 2010

AbstractThe cover picture shows Mariano Fernández‐Zúmel taking two steps at the same time. In the laboratory, two‐step reactions have been realized in one pot by coupling 1,1‐dichlorides with two olefins in sequential atom transfer radical addition (ATRA) reactions. Details are discussed in the article by K. Severin et al. on p. 249 ff.
Glutamate and the biology of gliomas
Authors: de Groot John , Sontheimer Harald 
Published: December 2010

AbstractSeveral important and previously unrecognized roles for the neurotransmitter glutamate in the biology of primary brain tumors have recently been elucidated. Glutamate is produced and released from glioma cells via the system xc− cystine glutamate transporter as a byproduct of glutathione synthesis. Glutamate appears to play a central role in the malignant phenotype of glioma via multiple mechanisms. By binding to peritumoral neuronal glutamate receptors, glutamate is responsible for seizure induction and similarly causes excitotoxicity, which aids the expansion of tumor cells into the space vacated by destroyed tissue. Glutamate also activates ionotropic and metabotropic glutamate receptors on glioma cells in a paracrine and autocrine manner. α‐Amino‐3‐hydroxy‐5‐methyl‐4‐isoaxazolepropionate acid (AMPA) glutamate receptors lack the GluR2 subunit rendering them Ca2+ permeable and capable of activating the AKT and MAPK pathways. Furthermore, these receptors are critical in aiding the invasion of glioma cells into normal brain. AMPA‐Rs accumulate at focal adhesion sites where they may indirectly mediate interactions between the extracellular matrix and integrins. Glutamate receptor stimulation results in activation of focal adhesion kinase, which is critical to the regulation of growth factor and integrin‐stimulated cell motility and invasion. The multitude of effects of glutamate on glioma biology supports the rationale for pharmacological targeting of glutamate receptors and transporters. Several ongoing and recently completed clinical trials are exploring the therapeutic potential of interrupting glutamate‐mediated brain tumor growth. © 2010 Wiley‐Liss, Inc.
Development and composition of irrigation in India: Temporal trends and regional patterns
Authors: Narayanamoorthy A. 
Published: December 2010

ABSTRACTIndia's irrigation sector is one of the largest in the world. The government alone has invested about Rs. 1556 billion (in current prices) in the irrigation sector as of 2001–2002. The irrigated area has increased from 20.9 million ha in 1950–1951 to 78.4 million ha in 2002–2003, an increase of almost four times. A large number of studies have analysed the impact of irrigation on various parameters. However, not many studies have analysed the direction of changes in the irrigated area across major sources and states. Therefore, an in‐depth analysis on the trends and development of irrigation is essential to frame appropriate irrigation policies for the future. In this study, an attempt is made to analyse the past development of the irrigated area across states using time series data from 1950–1951 to 2002–2003. This study shows that the growth in irrigated area across the states and sources has decelerated substantially during the post‐green revolution period (1980–1981 to 2002–2003) as compared to the green revolution period (1965–1966 to 1980–1981). The low‐cost source of irrigation, namely tanks, has declined sharply since the mid‐1960s, which may create livelihood problems for farmers relying on this source. Copyright © 2010 John Wiley & Sons, Ltd.
Parathyroid hormone regulates the distribution and osteoclastogenic potential of hematopoietic progenitors in the bone marrow
Authors: Jacome-Galarza Christian E , Lee Sun-Kyeong , Lorenzo Joseph A , Aguila Hector Leonardo 
Published: December 2010

Abstract
Parathyroid hormone (PTH) increases both the number of osteoclast in bone and the number of early hematopoietic stem cells (HSCs) in bone marrow. We previously characterized the phenotype of multiple populations of bone marrow cells with in vitro osteoclastogenic potential in mice. Here we examined whether intermittent administration of PTH influences these osteoclast progenitor (OCP) populations. C57BL/6 mice were treated with daily injections of bPTH(1–34) (80 µg/kg/day) for 7 or 14 days. We found that PTH caused a significant increase in the percentage of TN/CD115+CD117high and TN/CD115+CD117int cells (p &lt; .05) in bone marrow on day 7. In contrast, PTH decreased the absolute number of TN/CD115+CD117low cells by 39% on day 7 (p &lt; .05). On day 14, there was no effect of PTH on osteoclast progenitor distribution in vivo. However, PTH treatment for 7 and 14 days did increase receptor activator of NF-κB ligand (RANKL)– and macrophage colony-stimulating factor (M-CSF)–stimulated in vitro osteoclastogenesis and bone resorption in TN/CD115+ cells. In the periphery, 14 days of treatment increased the percentage and absolute numbers of HSCs (Lin−CD117+Sca-1+) in the spleen (p &lt; .05). These data correlated with an increase in the percent and absolute numbers of HSCs in bone marrow on day 14 (p &lt; .05). Interestingly, the effects on hematopoietic progenitors do not depend on osteoclast resorption activity. These results suggest that in vivo PTH treatment increased in vitro osteoclastogenesis and resorption without altering the number of osteoclast precursors. This implies that in vivo PTH induces sustained changes, possibly through an epigenetic mechanism, in the in vitro responsiveness of the cells to M-CSF and RANKL. © 2011 American Society for Bone and Mineral Research.
ACSL3 and GSK‐3β are essential for lipid upregulation induced by endoplasmic reticulum stress in liver cells
Authors: Chang Yung‐Sheng , Tsai Chien‐Ting , Huangfu Chien‐An , Huang Wen‐Ya , Lei Huan‐Yao , Lin Chiou‐Feng , Su Ih‐Jen , Chang Wen‐Tsan , Wu Pei‐Huan , Chen Ya‐Ting , Hung Jui‐Hsiang , Young Kung‐Chia , Lai Ming‐Derg 
Published: December 2010

AbstractThe endoplasmic reticulum (ER) is essential for lipid biosynthesis, and stress signals in this organelle are thought to alter lipid metabolism. Elucidating the mechanisms that underlie the dysregulation of lipid metabolism in hepatocytes may lead to novel therapeutic approaches for the treatment of lipid accumulation. We first tested the effects of several inhibitors on lipid dysregulation induced by tunicamycin, an ER stress inducer. Triacsin C, an inhibitor of long‐chain acyl‐CoA synthetase (ACSL) 1, 3, and 4, was the most potent among these inhibitors. We then analyzed the expression of the ACSL family during ER stress. The expression of ACSL3 was induced by ER stress in HuH‐7 cells and in mice livers. ACSL3 shRNA, but not ACSL1 shRNA, inhibited the induction of lipid accumulation. GSK‐3β inhibitors attenuated ACSL3 expression and the lipid accumulation induced by ER stress in HuH‐7 cells. shRNA that target GSK‐3β also inhibited the upregulation of ACSL3 and lipid accumulation in HuH‐7 and HepG2 cells. The hepatitis B virus mutant large surface protein, which is known to induce ER stress, increased the lipid content of cells. Similarly, Triacsin C, and GSK‐3β inhibitors abrogated the lipid dysregulation caused by the hepatitis B virus mutant large surface protein. Altogether, ACSL3 and GSK‐3β represent novel therapeutic targets for lipid dysregulation by ER stress. J. Cell. Biochem. 112: 881–893, 2011. © 2010 Wiley‐Liss, Inc.
Usp7 and Uhrf1 control ubiquitination and stability of the maintenance DNA methyltransferase Dnmt1
Authors: Qin Weihua , Leonhardt Heinrich , Spada Fabio 
Published: December 2010

AbstractIn mammals Dnmt1 is the DNA methyltransferase chiefly responsible for maintaining genomic methylation patterns through DNA replication cycles, but how its maintenance activity is controlled is still not well understood. Interestingly, Uhrf1, a crucial cofactor for maintenance of DNA methylation by Dnmt1, is endowed with E3 ubiquitin ligase activity. Here, we show that both Dnmt1 and Uhrf1 coprecipitate with ubiquitin specific peptidase 7 (Usp7), a de‐ubiquitinating enzyme. Overexpression of Uhrf1 and Usp7 resulted in opposite changes in the ubiquitination status and stability of Dnmt1. Our findings suggest that, by balancing Dnmt1 ubiquitination, Usp7 and Uhrf1 fine tune Dnmt1 stability. J. Cell. Biochem. 112: 439–444, 2011. © 2010 Wiley‐Liss, Inc.
Positive regulation of inositol 1,4,5‐trisphosphate‐induced ca2+ release by mammalian target of rapamycin (mTOR) in RINm5F cells
Authors: Frégeau Marc‐Olivier , Régimbald‐Dumas Yannik , Guillemette Gaétan 
Published: December 2010

AbstractThe inositol 1,4,5‐trisphosphate receptor (IP3R), a ligand‐gated Ca2+ channel, is the main regulator of intracellular Ca2+ mobilization in non‐excitable cells. An emerging body of evidence suggests that specific regulatory control of the Ca2+ signaling pathway is modulated by the activation of additional signaling pathways. In the present study, we investigated the influence of the PI3‐kinase/mammalian target of rapamycin (mTOR) pathway on the activity of the IP3R/Ca2+ signaling pathway in RINm5F cells. We used a co‐immunoprecipitation approach to show that mTOR physically interacts with IP3R‐3 in an mTOR activity‐dependent manner. We also showed that IP3R is phosphorylated by mTOR in cellulo. All the conditions known to modulate mTOR activity (IGF‐1, wortmannin, rapamycin, PP242, and nutrient starvation) were shown to modify carbachol‐induced Ca2+ signaling in RINm5F cells. Lastly, we used an assay that directly measures the activity of IP3R, to show that mTOR increases the apparent affinity of IP3R. Given that mTOR controls cell proliferation and cell homeostasis, and that Ca2+ plays a key role in these two phenomena, it follows that mTOR facilitates IP3R‐mediated Ca2+ release when the nutritional status of cells requires it. J. Cell. Biochem. 112: 723–733, 2011. © 2011 Wiley‐Liss, Inc.
Cdk1 is required for the self‐renewal of mouse embryonic stem cells
Authors: Zhang Wei Wei , Zhang Xiao Jie , Liu Hui Xian , Chen Jie , Ren Yong Hong , Huang Deng Gao , Zou Xiang Hong , Xiao Wei 
Published: December 2010

AbstractCyclin‐dependent kinase 1 (Cdk1) is indispensible for the early development of the embryo. However, its role in maintaining the undifferentiated state of the embryonic stem (ES) cells remains unknown. In this study, we dissected the function of Cdk1 in mouse ES cells by RNA‐interference and gene expression analyses. Cdk1 expression is tightly correlated with the undifferentiated state of the ES cells. Upon differentiation, Cdk1 expression reduced drastically. Cdk1 knock‐down by RNA interference resulted in the loss of proliferation and colony formation potential of the ES cells. Consequentially, expression of self‐renewal genes was reduced while differentiation markers such as Cdx2 were induced. Our results suggest a role for Cdk1 in maintaining the unique undifferentiated and self‐renewing state of the mouse ES cells. J. Cell. Biochem. 112: 942–948, 2011. © 2010 Wiley‐Liss, Inc.
Imaging the recruitment of cancer‐associated fibroblasts by liver‐metastatic colon cancer
Authors: Suetsugu Atsushi , Osawa Yosuke , Nagaki Masahito , Saji Shigetoyo , Moriwaki Hisataka , Bouvet Michael , Hoffman Robert M. 
Published: December 2010

AbstractThe tumor microenvironment (TME) is critical for tumor growth and progression. However, the formation of the TME is largely unknown. This report demonstrates a color‐coded imaging model in which the development of the TME can be visualized. In order to image the TME, a green fluorescent protein (GFP)‐expressing mouse was used as the host which expresses GFP in all organs but not the parenchymal cells of the liver. Non‐colored HCT‐116 human colon cancer cells were injected in the spleen of GFP nude mice which led to the formation of experimental liver metastasis. TME formation resulting from the liver metastasis was observed using the Olympus OV100 small animal fluorescence imaging system. HCT‐116 cells formed tumor colonies in the liver 28 days after cell transplantation to the spleen. GFP‐expressing host cells were recruited by the metastatic tumors as visualized by fluorescence imaging. A desmin positive area increased around and within the liver metastasis over time, suggesting cancer‐associated fibroblasts (CAFs) were recruited by the liver metastasis which have a role in tumor progression. The color‐coded model of the TME enables its formation to be visualized at the cellular level in vivo, in real‐time. This imaging model of the TME should lead to new visual targets in the TME. J. Cell. Biochem. 112: 949–953, 2011. © 2010 Wiley‐Liss, Inc.
Cellular prion proteins in human platelets show a phenotype different to those in brain tissues
Authors: Kuczius Thorsten , Kleinert Julia , Karch Helge , Sibrowski Walter , Kelsch Reinhard 
Published: December 2010

AbstractPrion diseases are characterized by high accumulation of infectious prion proteins (PrPSc) in brains. PrPSc are propagated by the conversion of host‐encoded cellular prion proteins (PrPC) which are essential for developing the disease but are heterogeneously expressed in brains. The disease can be transmitted to humans and animals through blood and blood products, however, little attention has been given to molecular characterization of PrPC in blood cells. In this presented study, we characterized phenotypically PrPC of platelets (plt) and characterized the proteins regarding their glycobanding profiles by quantitative immunoblotting using a panel of monoclonal antibodies. The glycosylation patterns of plt and brain PrPC were compared using the ratios of di‐, mono‐, and non‐glycosylated prions. The detergent solubility of plt and brain PrPC was also analyzed. The distinct banding patterns and detergent solubility of plt PrPC differed clearly from the glycosylation profiles and solubility characteristics of brain PrPC. Plt PrPC exhibited single or only few prion protein types, whereas brain PrPC showed more extensive banding patterns and lower detergent solubility. Plt PrPC are post‐translational modified differently from PrPC in brain. These findings suggest other or less physiological functions of plt PrPC than in brain. J. Cell. Biochem. 112: 954–962, 2011. © 2010 Wiley‐Liss, Inc.
How dynein and microtubules rotate the nucleus
Authors: Wu Jun , Lee Kristen C. , Dickinson Richard B. , Lele Tanmay P. 
Published: December 2010

AbstractIn living cells, a fluctuating torque is exerted on the nuclear surface but the origin of the torque is unclear. In this study, we found that the nuclear rotation angle is directionally persistent on a time scale of tens of minutes, but rotationally diffusive on longer time scales. Rotation required the activity of the microtubule motor dynein. We formulated a model based on microtubules undergoing dynamic instability, with tensional forces between a stationary centrosome and the nuclear surface mediated by dynein. Model simulations suggest that the persistence in rotation angle is due to the transient asymmetric configuration of microtubules exerting a net torque in one direction until the configuration is again randomized by dynamic instability. The model predicts that the rotational magnitude must depend on the distance between the nucleus and the centrosome. To test this prediction, rotation was quantified in patterned cells in which the cell's centrosome was close to the projected nuclear centroid. Consistent with the prediction, the angular displacement was found to decrease in these cells relative to unpatterned cells. This work provides the first mechanistic explanation for how nuclear dynein interactions with discrete microtubules emanating from a stationary centrosome cause rotational torque on the nucleus. J. Cell. Physiol. 226: 2666–2674, 2011. © 2010 Wiley‐Liss, Inc.