bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation of 2‐Alkylidene‐Substituted 1,3,4,5‐Tetramethylimidazolines and Their Reactivity Towards RhI Complexes and B(C6F5)3
Authors: Kronig Sabrina , Jones Peter G. , Tamm Matthias 
Published: February 2013

AbstractIn addition to the known 1,3,4,5‐tetramethyl‐2‐methyleneimidazoline (1a), which exhibits a highly polarized exocyclic C–C bond, a series of novel 2‐alkylidene‐substituted 1,3,4,5‐tetramethylimidazolines 1b–e were synthesized and characterized. The molecular structures of 1b, 1d, and 1e were determined by X‐ray diffraction analysis and revealed an increase in the polarization of the exocyclic C–C bond with increasing steric demand of the 2‐substituent. On the basis of their ylidic nature, 1a–e show enhanced basicity and reactivity towards Lewis acidic centers. Treatment of 1a and 1b with [{RhCl(cod)}2] or B(C6F5)3 afforded complexes of the type [(L)RhCl(cod)] (4a,b), [(L)RhCl(CO)2] (7a,b) (L = 1a,b) or classical Lewis acid/base adducts [(1a)B(C6F5)3] (8a) and [(1b)B(C6F5)3] (8b). In contrast, complexes [(L)RhCl(cod)] with 1c and 1d as ligands are not stable, and imidazolium dichlororhodate salts 6a and 6b were isolated instead. Rhodium–alkyl complexes 5a and 5b are assumed to be intermediates in this decomposition process, and 5a was characterized by X‐ray diffraction analysis. Furthermore, treatment of 1c and 1d with B(C6F5)3 did not afford classical Lewis adducts, and instead imidazolium hydridoborate salts 9a and 9b are formed by hydride abstraction. Surprisingly, we found that 1e does not react with [{RhCl(cod)}2] and forms an abnormal Lewis adduct 10 when treated with B(C6F5)3.
Brønsted Acid Catalyzed Highly Diastereoselective Michael‐Type Addition of Azlactones to Enones
Authors: Ávila Eloah P. , de Mello Amanda C. , Diniz Renata , Amarante Giovanni W. 
Published: February 2013

AbstractA highly regio‐ and diastereoselective 1,4‐addition of azlactones to enones catalyzed by a Brønsted acid is described. The Michael adducts were prepared in moderate to good yields and with complete control of the relative stereochemistry. In addition, two consecutive stereogenic centers were created, one of which was a quaternary stereocenter. The method was successfully extended to the first highly diastereoselective desymmetrization of dibenzylidene acetone.
Further observations of a decreasing atmospheric CO2 uptake capacity in the Canada Basin (Arctic Ocean) due to sea ice loss
Authors: Else Brent G.T. , Galley R.J. , Lansard B. , Barber D.G. , Brown K. , Miller L.A. , Mucci A. , Papakyriakou T.N. , Tremblay J.‐É. , Rysgaard S. 
Published: February 2013

AbstractUsing data collected in 2009, we evaluated the potential for the southeastern Canada Basin (Arctic Ocean) to act as an atmospheric CO2 sink under the summertime ice‐free conditions expected in the near future. Beneath a heavily decayed ice cover, we found surprisingly high pCO2sw (~290–320 µatm), considering that surface water temperatures were low and the influence of ice melt was strong. A simple model simulating melt of the remaining ice and exposure of the surface water for 100 days revealed a weak capacity for atmospheric CO2 uptake (mean flux: −2.4 mmol m−2 d−1), due largely to warming of the shallow mixed layer. Our results confirm a previous finding that the Canada Basin is not a significant sink of atmospheric CO2 under summertime ice‐free conditions and that increased ventilation of the surface mixed layer due to sea ice loss is weakening the sink even further.
The birth and death of lakes on young landscapes
Authors: Englund Göran , Eriksson Håkan , Nilsson Mats B. 
Published: February 2013

AbstractOngoing land uplift caused by postglacial isostatic rebound creates strong landscape‐age gradients alongside the Gulf of Bothnia, northern Scandinavia. Lakes are continuously generated on this dynamic landscape as the uplift isolates bays from sea inundation. However, concomitant with this process older lakes are lost as the basins are filled with sediments, creating a continuum of lake ages on the landscape. We studied the lake size and depth distributions and lake densities, along an age gradient covering 0–4500 years. Map data on the density, area, and elevation of lakes were combined with field‐based measurements of maximum basin depth. We find that young lake populations are densely distributed and dominated by small and shallow lakes. Over time, small and shallow lakes are lost by complete sediment filling, resulting in lower lake density and a shift in size and depth distributions towards larger, deeper lakes. Since lake filling is a universal process, we propose that these findings can be generalized to other gradients in landscape age.
Detecting human influence on extreme temperatures in China
Authors: Wen Qiuzi Han , Zhang Xuebin , Xu Ying , Wang Bin 
Published: February 2013

AbstractThis study compares observed and model‐simulated spatiotemporal patterns of changes in Chinese extreme temperatures during 1961–2007 using an optimal detection method. Four extreme indices, namely annual maximum daily maximum (TXx) and daily minimum (TNx) temperatures and annual minimum daily maximum (TXn) and daily minimum (TNn) temperatures, are studied. Model simulations are conducted with the CanESM2, which include six 5‐member ensembles under different historical forcings, i.e., four individual external forcings (greenhouse gases, anthropogenic aerosol, land use change, and solar irradiance), combined effect of natural forcings (solar irradiance and volcanic activity), and combined effect of all external forcings (both natural and anthropogenic forcings). We find that anthropogenic influence is clearly detectable in extreme temperatures over China. Additionally, anthropogenic forcing can also be separated from natural forcing in two‐signal analyses. The influence of natural forcings cannot be detected in any analysis. Moreover, there are indications that the effects of greenhouse gases and/or land use change may be separated from other anthropogenic forcings in warm extremes TXx and TNx in joint two‐signal analyses. These results suggest that further investigations of roles of individual anthropogenic forcing are justified, particularly in studies of extremely warm temperatures over China.
AXIOMATIC FOUNDATIONS FOR COST‐EFFECTIVENESS ANALYSIS
Authors: Canning David 
Published: February 2013

ABSTRACTWe show that individual utilities can be measured in units of healthy life years. Social preferences over these life metric utilities are assumed to satisfy the Pareto principle, anonymity, and invariance to a change in origin. These axioms generate a utilitarian social welfare function implying the use of cost‐effectiveness analysis in ordering health projects, based on maximizing the healthy years equivalents gained from a fixed health budget. For projects outside the health sector, our cost‐effectiveness axioms imply a form of cost–benefit analysis where both costs and benefits are measured in equivalent healthy life years. Copyright © 2013 John Wiley & Sons, Ltd.
Alantolactone inhibits growth of K562/adriamycin cells by downregulating Bcr/Abl and P‐glycoprotein expression
Authors: Yang Chunhui , Yang Jingbo , Sun Meiyan , Yan Jiangzhou , Meng Xiuxiang , Ma Tonghui 
Published: February 2013

AbstractAlantolactone, a sesquiterpene lactone containing an α‐methylene‐γ‐lactone group, is the active component of Inula helenium (Compositae), a traditional Chinese medicinal herb. It has been reported that alantolactone has the capacity to inhibit tumor cell growth through induction of apoptosis. The purpose of this study was to assess the effects of alantolactone in the adriamycin (ADR)‐resistant human erythroleukemia cell line K562/ADR, and provide evidence that it might function as a potent therapeutic agent in chronic myelogenous leukemia (CML) patients with Bcr/Abl and the multidrug‐resistance phenotype. Our results showed that alantolactone significantly inhibited K562/ADR cell growth by downregulating Bcr/Abl and P‐glycoprotein expression. Alantolactone also induced apoptosis via modulation of protein levels of Bcl‐2 family members, caspase activation, poly ADP ribose polymerase cleavage, and cytochrome C release. We also observed that alantolactone induced cell‐cycle arrest in the G2/M phase, downregulated cyclin B1 and cyclin‐dependent protein kinase 1, and upregulated the cyclin‐dependent kinase inhibitor p21. Together, these results demonstrate that alantolactone may be a potent therapeutic agent against CML, and a potential Bcr/Abl inhibitor. © 2013 IUBMB Life., 65(5):435–444, 2013.
Alkylglycerol monooxygenase
Authors: Watschinger Katrin , Werner Ernst R. 
Published: February 2013

AbstractAlkylglycerol monooxygenase (E.C. 1.14.16.5), also called glyceryl ether monooxygenase, is a tetrahydrobiopterin‐dependent enzyme. It is the only enzyme known to cleave the ether bond of alkylglycerols and lyso‐alkylglycerol phospholipids, including lyso‐platelet activating factor. Although it has been first described already in 1964, it was not possible so far to purify the protein. It took until 2010 to assign a sequence to this labile integral membrane enzyme by bioinformatic selection of candidate genes, recombinant expression of these, and sensitive monitoring of the enzymatic activity by a fluorescence‐based assay. The sequence shows no significant similarity with the other known tetrahydrobiopterin‐dependent enzymes but contains the fatty acid hydroxylase protein motif signature. Proteins containing this signature are all labile and catalyze reactions similar to the alkylglycerol monooxygenase reaction. They are thought to use a di‐iron centre for catalysis. Site directed mutagenesis of alkylglycerol monooxygenase defined a region of the active site and a conserved glutamate residue important for tetrahydrobiopterin interaction. Current research now focuses on defining a physiological role of this enzyme which occurs not only in mammals but also in commonly used model organisms such as zebrafish and the nematode Caenorhabditis elegans. © 2013 IUBMB Life 65(4):366–372, 2013.
Mechanisms of tryptophan and tyrosine hydroxylase
Authors: Roberts Kenneth M. , Fitzpatrick Paul F. 
Published: February 2013

AbstractThe aromatic amino acid hydroxylases tryptophan hydroxylase and tyrosine hydroxylase are responsible for the initial steps in the formation of serotonin and the catecholamine neurotransmitters, respectively. Both enzymes are nonheme iron‐dependent monooxygenases that catalyze the insertion of one atom of molecular oxygen onto the aromatic ring of their amino acid substrates, using a tetrahydropterin as a two electron donor to reduce the second oxygen atom to water. This review discusses the current understanding of the catalytic mechanism of these two enzymes. The reaction occurs as two sequential half reactions: a reaction between the active site iron, oxygen, and the tetrahydropterin to form a reactive FeIVO intermediate and hydroxylation of the amino acid by the FeIVO. The mechanism of formation of the FeIVO is unclear; however, considerable evidence suggests the formation of an FeII‐peroxypterin intermediate. The amino acid is hydroxylated by the FeIVO intermediate in an electrophilic aromatic substitution mechanism. © 2013 IUBMB Life 65(4):350–357, 2013.
Src kinases mediate VEGFR2 transactivation by the osteostatin domain of PTHrP to modulate osteoblastic function
Authors: García‐Martín Adela , Acitores Alicia , Maycas Marta , Villanueva‐Peñacarrillo María L. , Esbrit Pedro 
Published: February 2013

AbstractParathyroid hormone‐related protein (PTHrP) stimulates osteoblastic function through its N‐ and C‐terminal domains. Since the osteogenic action of the latter domain appears to depend at least in part on its interaction with the vascular endothelial growth factor (VEGF) system, we aimed to explore the putative mechanism underlying this interaction in osteoblasts. Using native conditions for protein extraction and immunoblotting, we found that both PTHrP (107–139) and the shorter PTHrP (107–111) peptide (known as osteostatin), at 100 nM, promoted the appearance of a VEGF receptor (VEGFR) 2 protein band of apparent Mr. wt. 230 kDa, which likely represents its activation by dimer formation, in mouse osteoblastic MC3T3‐E1 cells. Moreover, osteostatin (100 nM) maximally increased VEGFR2 phosphorylation at Tyr‐1059 within 5–10 min in both MC3T3‐E1 and rat osteoblastic osteosarcoma UMR‐106 cells. This phosphorylation elicited by osteostatin appears to be VEGF‐independent, but prevented by the VEGFR2 activation inhibitor SU1498 and also by the Src kinase inhibitors SU6656 and PP1. Furthermore, osteostatin induced phosphorylation of Src, extracellular signal‐regulated kinase (ERK) and Akt with a similar time course to that observed for VEGFR2 activation in these osteoblastic cells. This osteostatin‐dependent induction of ERK and Akt activation was abrogated by SU6656. Up‐regulation of VEGF and osteoprotegerin gene expression as well as the pro‐survival effect induced by osteostatin treatment were all prevented by both SU1498 and SU6656 in these osteoblastic cells. Collectively, these findings demonstrate that the osteostatin domain of C‐terminal PTHrP phosphorylates VEGFR2 through Src activation, which represents a mechanism for modulating osteoblastic function. J. Cell. Biochem. 114: 1404–1413, 2013. © 2012 Wiley Periodicals, Inc.
Structure and function of mycobacterium glycopeptidolipids from comparative genomics perspective
Authors: Pang Lei , Tian Xuelian , Pan Weihua , Xie Jianping 
Published: February 2013

AbstractGlycopeptidolipids (GPLs) attached to the outer surface of the greasy cell envelope, are a class of important glycolipids synthesized by several non‐tuberculosis mycobacteria. The deletion or structure change of GPLs confers several phenotypical changes including colony morphology, hydrophobicity, aggregation, sliding motility, and biofilm formation. In addition, GPLs, particular serovar specific GPLs, are important immunomodulators. This review aims to summarize the advance on the structure, function and biosynthesis of mycobacterium GPLs. J. Cell. Biochem. 114: 1705–1713, 2013. © 2013 Wiley Periodicals, Inc.
Specific route mapping visualized with GFP of single‐file streaming contralateral and systemic metastasis of Lewis lung carcinoma cells beginning within hours of orthotopic implantion
Authors: Rashidi Babak , Moossa Abdool R. , Hoffman Robert M. 
Published: February 2013

AbstractIn this study, we visualized the origin of Lewis lung carcinoma metastasis after transducing tumor cells with green fluorescent protein (GFP) and transplanting them orthotopically in the middle lobe of the right lung of nude mice. Metastasis was visualized in live tissue at single cell resolution by GFP‐expression as early as 18 h post‐tumor transplant. At this time, single‐file streaming lung carcinoma cells already had invaded inferiorly via a tubular lymphatic structure crossing the lower lobes of the lung to the ipsilateral diaphragmatic surface. By post‐implantation day 2, the ipsilateral lower lobes of the lung were involved with metastatic cells. By post‐implantation day 3, the ipsilateral lower lobes of the lung and the ipsilateral diaphragmatic surface were highly involved with streaming metastatic cells trafficking in single file. By day 4 post‐implantation, cancer cells invaded across the diaphragm to the contralateral diaphragmatic surface. Metastatic cells then invaded superiorly through a lymphatic vessel to involve the contralateral mediastinal lymph nodes. In this model of lung cancer, the origin of metastasis was an inferior invasion from the implanted tumor via a lymphatic duct to the ipsilateral diaphragmatic surface. The cancer cells from this site invaded on the surface of the diaphragm to the contralateral diaphragmatic surface and proceeded superiorly through a lymphatic duct to contralateral lymph nodes. Other organs such as the kidneys and the adrenal glands later became involved with metastasis with the contralateral mediastinal lymph nodes as the source. The use of GFP and the highly metastatic orthotopic lung cancer model allowed the visualization of the origin of metastasis at the single‐cell level and demonstrated the critical role of lymphatic ducts and the diaphragmatic surface as the path to the contralateral side. J. Cell. Biochem. 114: 1738–1743, 2013. © 2013 Wiley Periodicals, Inc.
Rapamycin inhibits BMP‐7‐induced osteogenic and lipogenic marker expressions in fetal rat calvarial cells
Authors: Yeh Lee‐Chuan C. , Ma Xiuye , Ford Jeffery J. , Adamo Martin L. , Lee John C. 
Published: February 2013

AbstractBone morphogenetic proteins (BMPs) promote osteoblast differentiation and bone formation in vitro and in vivo. BMPs canonically signal through Smad transcription factors, but BMPs may activate signaling pathways traditionally stimulated by growth factor tyrosine kinase receptors. Of these, the mTOR pathway has received considerable attention because BMPs activate P70S6K, a downstream effector of mTOR, suggesting that BMP‐induced osteogenesis is mediated by mTOR activation. However, contradictory effects of the mTOR inhibitor rapamycin (RAPA) on bone formation have been reported. Since bone formation is thought to be inversely related to lipid accumulation and mTOR is also important for lipid synthesis, we postulated that BMP‐7 may stimulate lipogenic enzyme expression in a RAPA‐sensitive mechanism. To test this hypothesis, we determined the effects of RAPA on BMP‐7‐stimulated expression of osteogenic and lipogenic markers in cultured fetal rat calvarial cells. Our study showed that BMP‐7 promoted the expression of osteogenic and lipogenic markers. The effect of BMP‐7 on osteogenic markers was greater in magnitude than on lipogenic markers and was temporally more sustained. RAPA inhibited basal and BMP‐7‐stimulated osteogenic and lipogenic marker expression and bone nodule mineralization. The acetyl CoA carboxylase inhibitor TOFA stimulated the expression of osteoblast differentiation markers, whereas palmitate suppressed their expression. We speculate that the BMP‐7‐stimulated adipogenesis is part of the normal anabolic response to BMPs, but that inappropriate activation of the lipid biosynthetic pathway by mTOR could have deleterious effects on bone formation and could explain paradoxical effects of RAPA to promote bone formation. J. Cell. Biochem. 114: 1760–1771, 2013. © 2013 Wiley Periodicals, Inc.
Functional studies of MP62 during male chromatin decondensation in sea urchins
Authors: Iribarren Claudio , Hermosilla Viviana , Morin Violeta , Puchi Marcia 
Published: February 2013

AbstractIn amphibians, sperm histone transition post‐fertilization during male pronucleus formation is commanded by histone chaperone Nucleoplasmin (NPM). Here, we report the first studies to analyze the participation of a Nucleoplasmin‐like protein on male chromatin remodeling in sea urchins. In this report, we present the molecular characterization of a nucleoplasmin‐like protein that is present in non fertilized eggs and early zygotes in sea urchin specie Tetrapygus niger. This protein, named MP62 can interact with sperm histones in vitro. By male chromatin decondensation assays and immunodepletion experiments in vitro, we have demonstrated that this protein is responsible for sperm nucleosome disorganization. Furthermore, as amphibian nucleoplasmin MP62 is phosphorylated in vivo immediately post‐fertilization and this phosphorylation is dependent on CDK‐cyclin activities found after fertilization. As we shown, olomoucine and roscovitine inhibits male nucleosome decondensation, sperm histone replacement in vitro and MP62 phosphorylation in vivo. This is the first report of a nucleoplasmin‐like activity in sea urchins participating during male pronucleus formation post‐fecundation. J. Cell. Biochem. 114: 1779–1788, 2013. © 2013 Wiley Periodicals, Inc.
IS IT BOTH WHAT YOU KNOW AND WHO YOU KNOW? HUMAN CAPITAL, SOCIAL CAPITAL AND ENTREPRENEURIAL SUCCESS
Authors: Kolstad Ivar , Wiig Arne 
Published: February 2013

AbstractThis paper analyses the importance of human and social capital for entrepreneurial success, using survey data of 459 urban entrepreneurs in Luanda, Angola. The paper offers four main findings: (i) an added year of schooling significantly increases entrepreneurial profits; (ii) different family background variables are associated with the educational attainment of men and women, indicating that educational attainment is gendered; (iii) profits are substantially lower for entrepreneurs suffering from chronic illness; and (iv) entrepreneurs who know a local police officer have higher profits, suggesting that specific forms of networks are related to entrepreneurial success. Copyright © 2013 John Wiley & Sons, Ltd.
Physical Properties, Crystallization, and Thermal/Hydrolytic Degradation of Poly(L‐lactide)/Nano/Micro‐Diamond Composites
Authors: Tsuji Hideto , Aratani Toshiyuki , Takikawa Hirofumi 
Published: February 2013

AbstractThe effects of incorporated nano/micro‐diamond (NMD) on the physical properties, crystallization, thermal/hydrolytic degradation of poly(L‐lactic acid) (PLLA) were investigated for a wide NMD concentration range of 0–10 wt.‐%. Incorporated NMD increased the tensile modulus and strength of PLLA films but decreased the elongation at break of PLLA films. Incorporated NMD accelerated the crystallization of PLLA during heating and cooling and increased the absolute crystallization enthalpy of PLLA films (except for an NMD concentration of 10 wt.‐% during cooling) but did not alter the crystallization mechanism. Incorporated NMD increased and decreased the thermal stability of PLLA films for NMD concentrations of 1–5 and 10 wt.‐%, respectively, and increased the hydrolytic degradation resistance of PLLA films. magnified image
Association of isolated short fetal femur with intrauterine growth restriction
Authors: Vermeer N. , Bekker M. N. 
Published: February 2013

ABSTRACTObjectivesTo analyze the outcomes of fetuses referred because of short femur length.MethodsThis was a retrospective study of all singleton pregnancies referred to a tertiary care referral hospital with a femur length below the 5th percentile. All ultrasound scan reports, including Doppler, fetal karyotyping, pregnancy outcome and neonatal data were analyzed.ResultsIn 112 patients, 87 (78%) had an isolated short femur and 25 (22%) had a non‐isolated short femur. The non‐isolated cases consisted of chromosomal disorders (n = 6), skeletal abnormalities (n = 6), multiple abnormalities (n = 12) and 1 genetic disorder. In the isolated group 37 cases (43%) were intrauterine growth restricted (positive likelihood ratio 1.20, negative likelihood ratio 0.45). In 33 cases the short femur was unexplained and 17 referrals were considered false‐positive. The growth restricted group had significant more abnormal Doppler measurements (p = 0.01), caesarean deliveries (p = 0.043) and admissions to the neonatal intensive care unit (p = 0.001).ConclusionAn isolated short femur is associated with intrauterine growth restriction and adverse pregnancy outcome. © 2013 John Wiley & Sons, Ltd.