bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of Ni‐Coated WS2 Nanotubes for Hydrodesulfurization Catalysis
Authors: Komarneni Mallikharjuna Rao , Yu Zhongqing , Burghaus Uwe , Tsverin Yulia , Zak Alla , Feldman Yishay , Tenne Reshef 
Published: December 2012

AbstractA reactivity screening of new nano‐hydrodesulfurization (HDS) catalysts was conducted using an ambient pressure flow reactor as well as ultra‐high vacuum kinetics techniques. Thiophene was used as a probe molecule. Clean multiwall WS2 nanotubes (INT‐WS2) as well as Ni‐ and Co‐coated INT‐WS2 were considered. In addition, undoped MoS2 and Re‐doped nanoparticles with fullerene‐like structures were studied. Commercial Ni and Co HDS catalysts from Haldor Topsoe (Denmark) as well as “nano MoS2” from Impex Corp. (USA) were considered as reference materials. The lab‐synthesized and commercial systems broke down thiophene into quite similar non‐sulfur containing products, as identified by a gas chromatograph. The Ni and Co promoted catalysts showed similar thiophene conversion rates. Although the commercial catalysts had larger thiophene conversion rates than the laboratory‐synthesized systems, the Re‐doped nano‐HDS catalyst showed quite low rates of formation of H2S, an undesirable by‐product.
Tip‐Induced Charging of Free Standing Semiconductor Nanowires and Carbon Nanotubes
Authors: Schäfer Sebastian , Wang Zhe , Rammelberg Holger U. , Kipp Tobias , Mews Alf 
Published: December 2012

AbstractWe investigate the distribution of charges injected into one‐dimensional nanostructures like semiconductor nanowires and carbon nanotubes. The charges are injected by an atomic force microscope tip and monitored by means of electrostatic force microscopy. We demonstrate that the charges distribute rapidly along the axes of both types of nanostructures. The charges deposited on nanowires are shown to migrate to the substrate on a shorter time scale than those deposited on nanotubes, while the holes migrate even slower than the electrons. This behaviour is attributed to the amount and type of available trap states in the respective nanostructure.
Recent Progress in Photocatalysis Mediated by Colloidal II‐VI Nanocrystals
Authors: Wilker Molly B. , Schnitzenbaumer Kyle J. , Dukovic Gordana 
Published: December 2012

AbstractThe use of photoexcited electrons and holes in semiconductor nanocrystals as reduction and oxidation reagents is an intriguing way of harvesting photon energy to drive chemical reactions. This review focuses on recent research efforts to understand and control the photocatalytic processes mediated by colloidal II‐VI nanocrystalline materials, such as cadmium and zinc chalcogenides. First, we highlight how nanocrystal properties govern the rates and efficiencies of charge‐transfer processes relevant to photocatalysis. We then describe the use of nanocrystal catalyst heterostructures for fuel‐forming reactions, most commonly H2 generation. Finally, we review the use of nanocrystal photocatalysis as a synthetic tool for metal–semiconductor nano‐heterostructures.
The vertical distribution of fish in the open water area of a deep temperate mesotrophic lake assessed by hydroacoustics and midwater trawling
Authors: Jůza Tomáš , Frouzová Jaroslava , Brämick Uwe , Draštík Vladislav , Mrkvička Tomáš , Kubečka Jan 
Published: December 2012

AbstractThe fish stock of a deep temperate, mesotrophic lake was sampled at different depths using a fixed‐frame fry trawl, during two nights in mid‐September 2009. Additionally, horizontal and vertical hydroacoustics were used simultaneously to evaluate fish abundance and biomass estimates obtained by the trawl. Roach Rutilus rutilus and smelt Osmerus eperlanus were the dominant species of young‐of‐the‐year (YOY) fish in the trawl catches from the surface layers (0–9 m). Bleak Alburnus alburnus dominated the catch of older fish in the upper part of the surface profile (0–6 m). Around the thermocline (9–13 m) smelt dominated the catches of both the YOY and older fish. Beneath the thermocline (13–36 m) vendace Coregonus albula dominated the catch of YOY fish, and smelt was the only species of older fish in the trawl catches. Species composition, abundance and biomass of the YOY and older fish were heterogeneous throughout the depth profiles of the lake, but only abundance differed significantly between the layers. The hydroacoustics gave relatively similar estimates of abundance and biomass to those obtained by the trawl in all the depths sampled. Our results indicate that there is a clear separation of small fish of different species along the vertical profile of a deep temperate lake during the night, and an unequal vertical distribution of fish abundance and biomass. The similarity of the trawl and hydroacoustics estimates of abundances and biomass indicated that the trawl sampling did not cause important avoidance reactions of small fish during the night in this deep temperate lake (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sex and age modify biochemical and skeletal manifestations of chronic hyperparathyroidism by altering target organ responses to Ca2+ and parathyroid hormone in mice
Authors: Cheng Zhiqiang , Liang Nathan , Chen Tsui-Hua , Li Alfred , Santa Maria Christian , You Michael , Ho Hanson , Song Fuqing , Bikle Daniel , Tu Chialing , Shoback Dolores , Chang Wenhan 
Published: December 2012

Abstract
We studied mice with or without heterozygous deletion of the Casr in the parathyroid gland (PTG) [PTGCaSR(+/–)] to delineate effects of age and sex on manifestations of hyperparathyroidism (HPT). In control mice, aging induced a left-shift in the Ca2+/parathyroid hormone (PTH) set point accompanied by increased PTG CaSR expression along with lowered serum Ca2+ and mildly increased PTH levels, suggesting adaptive responses of PTGs to aging-induced changes in mineral homeostasis. The aging effects on Ca2+/PTH set point and CaSR expression were significantly blunted in PTGCaSR(+/–) mice, who showed instead progressively elevated PTH levels with age, especially in 12-month-old females. These 12-month-old knockout mice demonstrated resistance to their high PTH levels in that serum 1,25-dihydroxyvitamin D (1,25-D) levels and RNA expression of renal Cyp27b1 and expression of genes involved in Ca2+ transport in kidney and intestine were unresponsive to the rising PTH levels. Such changes may promote negative Ca2+ balance, which further exacerbate the HPT. Skeletal responses to HPT were age-, sex-, and site-dependent. In control mice of either sex, trabecular bone in the distal femur decreased whereas cortical bone in the tibiofibular junction increased with age. In male PTGCaSR(+/–) mice, anabolic actions of the elevated PTH levels seemed to protect against trabecular bone loss at ≥3 months of age at the expense of cortical bone loss. In contrast, HPT produced catabolic effects on trabecular bone and anabolic effects on cortical bone in 3-month-old females; but these effects reversed by 12 months, preserving trabecular bone in aging mice. We demonstrate that the CaSR plays a central role in the adaptive responses of parathyroid function to age-induced changes in mineral metabolism and in target organ responses to calciotropic hormones. Restraining the ability of the PTG to upregulate CaSRs by heterozygous gene deletion contributes to biochemical and skeletal manifestations of HPT, especially in aging females. © 2013 American Society for Bone and Mineral Research.
Role of JAK2–STAT3 in TLR2‐mediated tissue factor expression
Authors: Park Dae‐Weon , Lyu Ji Hyo , Kim Jin‐Sik , Chin Haemin , Bae Yoe‐Sik , Baek Suk‐Hwan 
Published: December 2012

AbstractTissue factor (TF) is a core protein with an essential function in the coagulation cascade that maintains the homeostasis of the blood vessels. TF not only participates in neointima formation, but also causes the development of atherosclerosis. This study investigated the mechanism regulating TF expression in macrophages using Pam3CSK4, a TLR2 ligand. Pam3CSK4 induced TF expression in two types of macrophages (Raw264.7 and BMDM), but not in TLR2 KO mice derived BMDM. Pam3CSK4 induced TF expression was inhibited by pretreatment with pan‐JAK inhibitor or JAK2 inhibitor AG490. JAK2 knock‐down by siRNA inhibited Pam3CSK4 induced TF expression. Pam3CSK4 stimulated STAT3 phosphorylation (S727), while STAT3 knock‐down by siRNA reduced Pam3CSK4 induced TF expression. These results suggest that Pam3CSK4 induced TF expression is regulated by the JAK2–STAT3 signaling pathway. Pam3CSK4, unlike increased TF expression, significantly decreased RGS2 expression, while RGS2 overexpression decreased Pam3CSK4 induced TF expression. Inhibition of TF by RGS2 WT did not occur in mutants with flawed RGS domains. We also investigated the correlation between RGS2 and STAT3 phosphorylation. RGS2 knock‐down elevated Pam3CSK4 induced STAT3 phosphorylation, but RGS2 overexpression had the opposite effect on STAT3 phosphorylation. These results suggest that, while Pam3CSK4 induced TF expression is regulated by JAK2–STAT3 signaling, RGS2 is a negative regulator targeted to STAT3. J. Cell. Biochem. 114: 1315–1321, 2013. © 2012 Wiley Periodicals, Inc.
Tumor suppressor gene p16/INK4A/CDKN2A‐dependent regulation into and out of the cell cycle in a spontaneous canine model of breast cancer
Authors: Agarwal Payal , Sandey Maninder , DeInnocentes Patricia , Bird R. Curtis 
Published: December 2012

Abstractp16/INK4A/CDKN2A is an important tumor suppressor gene that arrests cell cycle in G1 phase inhibiting binding of CDK4/6 with cyclin D1, leaving the Rb tumor suppressor protein unphosphorylated and E2F bound and inactive. We hypothesized that p16 has a role in exit from cell cycle that becomes defective in cancer cells. Well characterized p16‐defective canine mammary cancer cell lines (CMT28, CMT27, and CMT12), derived stably p16‐transfected CMT cell clones (CMT27A, CMT27H, CMT28A, and CMT28F), and normal canine fibroblasts (NCF), were used to investigate expression of p16 after serum starvation into quiescence followed by re‐feeding to induce cell cycle re‐entry. The parental CMT cell lines used lack p16 expression either at the mRNA or protein expression levels, while p27 and other p16‐associated proteins, including CDK4, CDK6, cyclin D1, and Rb, were expressed. We have successfully demonstrated cell cycle arrest and relatively synchronous cell cycle re‐entry in parental CMT12, CMT28 and NCF cells as well as p16 transfected CMT27A, CMT27H, CMT28A, and CMT28F cells and confirmed this by3H‐thymidine incorporation and flow cytometric analysis of cell cycle phase distribution. p16‐transfected CMT27A and CMT27H cells exited cell cycle post‐serum‐starvation in contrast to parental CMT27 cells. NCF, CMT27A, and CMT28F cells expressed upregulated levels of p27 and p16 mRNA, post‐serum starvation, as cells exited cell cycle and entered quiescence. Because quiescence and differentiation are associated with increased levels of p27, our data demonstrating that p16 was upregulated along with p27 during quiescence, suggests a potential role for p16 in maintaining these non‐proliferative states. J. Cell. Biochem. 114: 1355–1363, 2013. © 2012 Wiley Periodicals, Inc.
Reply to ‘comment on “extending Hirshfeld‐I to bulk and periodic materials”’
Authors: Vanpoucke Danny E. P. , Van Driessche Isabel , Bultinck Patrick 
Published: December 2012

AbstractThe issues raised in the comment by Manz are addressed through the presentation of calculated atomic charges for NaF, NaCl, MgO, SrTiO$$_3$$, and La$$_2$$Ce$$_2$$O$$_7$$, using our previously presented method for calculating Hirshfeld‐I charges in solids (Vanpoucke et al., J. Comput. Chem. doi: 10.1002/jcc.23088). It is shown that the use of pseudovalence charges is sufficient to retrieve the full all‐electron Hirshfeld‐I charges to good accuracy. Furthermore, we present timing results of different systems, containing up to over 200 atoms, underlining the relatively low cost for large systems. A number of theoretical issues are formulated, pointing out mainly that care must be taken when deriving new atoms in molecules methods based on “expectations” for atomic charges. © 2012 Wiley Periodicals, Inc.
New insight into the electronic structure of iron(IV)‐oxo porphyrin compound I. A quantum chemical topological analysis
Authors: Viciano Ignacio , Berski Slawomir , Martí Sergio , Andrés Juan 
Published: December 2012

AbstractThe electronic structure of iron‐oxo porphyrin π‐cation radical complex Por·+FeIVO (SH) has been studied for doublet and quartet electronic states by means of two methods of the quantum chemical topology analysis: electron localization function (ELF) η(r) and electron density ρ(r). The formation of this complex leads to essential perturbation of the topological structure of the carbon–carbon bonds in porphyrin moiety. The double CC bonds in the pyrrole anion subunits, represented by pair of bonding disynaptic basins Vi=1,2(C,C) in isolated porphyrin, are replaced by single attractor V(C,C)i=1–20after complexation with the Fe cation. The iron–nitrogen bonds are covalent dative bonds, N→Fe, described by the disynaptic bonding basins V(Fe,N)i=1–4, where electron density is almost formed by the lone pairs of the N atoms. The nature of the iron–oxygen bond predicted by the ELF topological analysis, shows a main contribution of the electrostatic interaction, Feδ+···Oδ−, as long as no attractors between the C(Fe) and C(O) core basins were found, although there are common surfaces between the iron and oxygen basines and coupling between iron and oxygen lone pairs, that could be interpreted as a charge‐shift bond. The FeS bond, characterized by the disynaptic bonding basin V(Fe,S), is partially a dative bond with the lone pair donated from sulfur atom. The change of electronic state from the doublet (M= 2) to quartet (M= 4) leads to reorganization of spin polarization, which is observed only for the porphyrin skeleton (−0.43e to 0.50e) and SH bond (−0.55e to 0.52e). © 2012 Wiley Periodicals, Inc.
Effect of co‐substrate sorbitol different feeding strategies on human growth hormone production by recombinant Pichia pastoris
Authors: Çalık Pınar , Bozkurt Bahar , Zerze Gül H. , İnankur Bahar , Bayraktar Eda , Boy Erdem , Orman Mehmet Ali , Açık Eda , Özdamar Tunçer H. 
Published: December 2012

AbstractBACKGROUNDEffects of co‐substrate sorbitol different feeding strategies on recombinant human growth hormone (rhGH) production by Pichia pastoris hGH‐Mut+ were investigated by eight designed experiments grouped as: (i) fed‐batch methanol feeding without the co‐substrate; (ii) fed‐batch methanol feeding with pulse sorbitol feeding; (iii) fed‐batch methanol feeding together with fed‐batch sorbitol feeding at t = 0–15 h, followed by fed‐batch methanol feeding; and (iv) fed‐batch methanol and sorbitol feeding at t = 0–30 h, followed with fed‐batch methanol feeding.RESULTSThe highest rhGH and cell concentrations were achieved, respectively, as 0.64 g L−1 and 105 g L−1 at t = 42 h of induction phase, with the strategy where methanol was fed to the system at a pre‐determined feeding rate of μM0=0.03 h−1, and sorbitol concentration was kept at 50 g L−1 at t = 0–15 h of the rhGH production phase where the specific growth rate on sorbitol was μS0=0.025 h−1. The overall cell and product yield on total substrate were found as 0.26 g g−1 and 2.26 mg g−1, respectively.CONCLUSIONThis work demonstrates that co‐carbon source, sorbitol, feeding strategy is as important as methanol feeding strategy in recombinant protein production by Mut+ strains of P. pastoris. © 2012 Society of Chemical Industry
The integration of flow reactors into synthetic organic chemistry
Authors: Baxendale Ian R. 
Published: December 2012

AbstractThe material presented in this review is based upon discussions and interactions with members of the Department of Chemistry and Biochemistry within the University of Windsor, Ontario, Canada. This article explores the changing face of chemical synthesis with regard to the impact of flow based chemical processing technologies. Highlighted works from the Innovative Technology Centre (ITC), Cambridge, UK, are used to illustrate the alternative synthetic practices available to modern research chemists. The dominant theme of the review is the synergistic effects encountered by combining the advantages of continuous processing regimes with the power of immobilized reagents and scavenger systems for multi‐step organic chemistry. © 2012 Society of Chemical Industry
Comparison of local sine wave modeling with harmonic phase analysis for the assessment of myocardial strain
Authors: Miller Christopher A. , Borg Alex , Clark David , Steadman Christopher D. , McCann Gerry P. , Clarysse Patrick , Croisille Pierre , Schmitt Matthias 
Published: December 2012

PurposeTo compare local sine‐wave modeling (SinMod) with harmonic phase analysis (HARP), for assessment of left ventricular (LV) circumferential strain (εcc) from tagged cardiovascular magnetic resonance images.Materials and MethodsMid‐ventricular spatial modulation of magnetization was performed in 60 participants (15 each with hypertrophic, dilated or ischemic cardiomyopathy and 15 healthy controls) at 1.5 Tesla. Global and segmental peak transmural εcc were measured using HARP and SinMod. Repeated measurements were performed on 25% of examinations to assess observer variability. Effect of contrast was assessed in 10 additional patients.ResultsSinMod showed a high level of agreement with HARP for global εcc (mean difference −0.02, 95% limits of agreement −6.46 to 6.43%). Agreement was much lower for segmental εcc. Both methods showed excellent observer agreement for global εcc (intraclass correlation coefficient >0.75). Observer agreement for segmental εcc was also excellent with SinMod, but was significantly lower with HARP. Analysis time was significantly shorter using SinMod. Pre‐ and postcontrast εcc measurements were not significantly different using either technique, although postcontrast measurements showed greater variability with HARP.ConclusionSinMod and HARP‐based measurements of global εcc have a high level of agreement, but segmental agreement is substantially lower. SinMod has generally lower observer variability, is faster and is less affected by contrast, but requires further validation. J. Magn. Reson. Imaging 2013;38:320–328. © 2012 Wiley Periodicals, Inc.
Inter‐ and intra‐rater reproducibility of quantitative dynamic contrast enhanced MRI using TWIST perfusion data in a uterine fibroid model
Authors: Davenport Matthew S. , Heye Tobias , Dale Brian M. , Horvath Jeffrey J. , Breault Steven R. , Feuerlein Sebastian , Bashir Mustafa R. , Boll Daniel T. , Merkle Elmar M. 
Published: December 2012

PurposeTo determine the reproducibility of TWIST‐derived (Time‐Resolved Angiography with Interleaved Stochastic Trajectories) quantitative dynamic contrast enhanced (DCE) MRI in a uterine fibroid model.Materials and MethodsThe institutional review board approved this retrospective study. Dynamic contrast‐enhanced TWIST datasets from 15 randomly selected 1.5 Tesla pelvic MR studies were postprocessed. Five readers recorded kinetic parameters (Ktrans [volume transfer constant], ve [extracellular extravascular space volume], kep [flux rate constant], iAUC [initial area under the gadolinium‐time curve]) of the largest uterine fibroid using three region‐of‐interest (ROI) selection methods. Measurements were randomized and repeated three times, and measures of reproducibility were calculated.ResultsThe intra‐rater coefficients of variation (CVs, brackets indicate 95% confidence intervals) varied from 4.6% to 7.6% (Ktrans 7.6% [6.1%, 9.1%], kep 7.2% [5.9%, 8.5%], ve 4.6% [3.8%, 5.4%], and iAUC 7.2% [6.1%, 8.3%]). ve was the most reproducible (P < 0.05). Inter‐rater reproducibility was significantly (P < 0.05) greater for the large ROI method (range of intraclass correlation coefficients [ICCs] = 0.80–0.98 versus 0.48–0.63 [user‐defined ROI] versus 0.41–0.69 [targeted ROI]). The uterine fibroid accounted for the greatest fraction of variance for the large ROI method (range across kinetic parameters: 83–98% versus 56–69% [user‐defined ROI] versus 47–74% [targeted ROI]). The reader accounted for the greatest fraction of variance for the user‐defined ROI method (0.4–14.1% versus 0.1–3.0% [large ROI] versus <0.1–1.5% [targeted ROI]).ConclusionChanges in TWIST‐derived DCE‐MRI kinetic parameters of up to 9–15% may be attributable to measurement error. Large DCE‐MRI regions of interest are the most reproducible across multiple readers. J. Magn. Reson. Imaging 2013;38:329–335. © 2012 Wiley Periodicals, Inc.
High friction moments in large hard‐on‐hard hip replacement bearings in conditions of poor lubrication
Authors: Bishop Nicholas E. , Hothan Arne , Morlock Michael M. 
Published: December 2012

AbstractDisappointing clinical results for large diameter metal replacement bearings for the hip are related to compromised lubrication due to poor cup placement, which increases wear as well as friction moments. The latter can cause overload of the implant–bone interfaces and the taper junction between head and stem. We investigated the influence of lubrication conditions on friction moments in modern hip bearings. Friction moments for large diameter metal and ceramic bearings were measured in a hip simulator with cup angles varying from 0° to 60°. Two diameters were tested for each bearing material, and measurements were made in serum and in dry conditions, representing severely compromised lubrication. Moments were lower for the ceramic bearings than for the metal bearings in lubricated conditions, but approached those for metal bearings at high cup inclination. In dry conditions, friction moments increased twofold to 12 Nm for metal bearings. For ceramic bearings, the increase was more than fivefold to over 25 Nm. Although large diameter ceramic bearings demonstrate an improvement in friction characteristics in the lubricated condition, they could potentially replicate problems currently experienced due to high friction moments in metal bearings once lubrication is compromised. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 807–813, 2013
Synthesis of Maleimide‐Functionalyzed HPMA‐Copolymers and in vitro Characterization of the aRAGE‐ and Human Immunoglobulin (huIgG)–Polymer Conjugates
Authors: Tappertzhofen Kristof , Metz Verena V. , Hubo Mario , Barz Matthias , Postina Rolf , Jonuleit Helmut , Zentel Rudolf 
Published: December 2012

AbstractHerein the synthesis of antibody–polymer conjugates, with a quite narrow dispersity based on the polymer HPMA, are reported. These conjugates are synthesized by coupling antibodies to maleimide‐functionalized poly(N‐(2‐hydroxypropyl)‐methacrylamide) (poly‐HPMA) copolymers derived through reversible addition‐fragmentation chain transfer (RAFT) polymerization of pentafluorophenyl methacrylate via the intermediate step of an activated ester polymer. We develop a protocol that allows the attachment of two different model antibodies, monoclonal anti‐RAGE (receptor for advanced glycation end‐products) antibody, and polyclonal human immunoglobulin (huIgG). Modification of the antibody and conjugation is monitored by SDS‐PAGE electrophoresis. Preserved affinity is demonstrated by Western Blott and cell‐uptake analysis, for example, to cells of the immune system. magnified image