bluuebunny/crossref_metadata_2025_split huggingface dataset:
Straightforward Iron‐Catalyzed Synthesis of Nitriles by Dehydration of Primary Amides
Authors: Enthaler Stephan 
Published: July 2011

AbstractIn the present study, the iron‐catalyzed dehydration of a range of amides to the corresponding nitriles by usingN‐methyl‐N‐(trimethylsilyl)trifluoroacetamide (MSTFA) as the dehydration reagent has been explored. After investigating different reaction parameters (e.g., iron source, solvent, catalyst loading) with FeCl2·4H2O, an excellent and easily accessible precatalyst was found. The obtained system (5.0 mol‐% [Fe], 3.0 equiv. MSTFA) was highly active and dehydrated a broad scope of amides selectively to the corresponding nitriles under mild reaction conditions (THF, 70 °C) within two hours (yields: >99 %, selectivities: >99 %).
Arsenic removal from aqueous system using natural and modified (Kula ebonite and zeolite) adsorbents
Authors: Gülbaş Gökçe , Tirtom V. Nüket , Çelik Ali , Dost Kenan 
Published: July 2011

AbstractNatural adsorbents (Kula ebonite, zeolite and zeolite treated with Al2(SO4)3; Al2(SO4)3+NaOH; FeCl3 and FeCl3+NaOH) were prepared and employed by means of batch method for selective adsorption and removal of arsenic from aqueous system. The influences of different parameters such as, contact time, pH, temperature, and concentration of adsorbate on adsorption performance of zeolite and zeolite treated with FeCl3 and FeCl3+NaOH were studied in order to optimize the adsorption conditions. Batch adsorption studies have shown that removal capacity of zeolite from aqueous solutions can be increased by FeCl3 and FeCl3+NaOH treatment. The maximum adsorption capacities were 1.99 and 3.43 mg g−1 of zeolite which was treated with FeCl3 and FeCl3+NaOH for arsenic, respectively. The adsorption data obtained follows a first‐order rate expression and fits the Langmuir isotherm that has been used to obtain thethermodynamic parameters. In addition, the thermodynamic parameters, standard free energy (ΔG°), standard enthalpy (ΔH°), standard entropy (ΔS°) of the adsorption process were calculated. It was found that the adsorption of arsenic on zeolite was exothermic. © 2011 American Institute of Chemical Engineers Environ Prog, 2011
Spurious currents in finite element based level set methods for two‐phase flow
Authors: Zahedi Sara , Kronbichler Martin , Kreiss Gunilla 
Published: July 2011

SUMMARYA study of spurious currents in continuous finite element based simulations of the incompressible Navier–Stokes equations for two‐phase flows is presented on the basis of computations on a circular drop in equilibrium. The conservative and the standard level set methods are used. It is shown that a sharp surface tension force, expressed as a line integral along the interface, can give rise to large spurious currents and oscillations in the pressure that do not decrease with mesh refinement. If instead a regularized surface tension representation is used, exact force balance at the interface is possible, both for a fully coupled discretization approach and for a fractional step projection method. However, the numerical curvature calculation introduces errors that cause spurious currents. Different ways to extend the curvature from the interface to the whole domain are discussed and investigated. The impact of using different finite element spaces and stabilization methods is also considered. Copyright © 2011 John Wiley & Sons, Ltd.
A three‐dimensional numerical internal tidal model involving adjoint method
Authors: Chen Haibo , Miao Chunbao , Lv Xianqing 
Published: July 2011

SUMMARYA three‐dimensional internal tidal model involving the adjoint method is constructed based on the nonlinear, time‐dependent, free‐surface hydrodynamic equations in spherical coordinates horizontally, and isopycnic coordinates vertically, subject to the hydrostatic approximations. This model consists of two submodels: the forward model is used for the simulation of internal tides, while the adjoint model is used for optimization of modal parameters. Mode splitting technique is employed in both forward and adjoint models. In this model, the adjoint method is employed to estimate model parameters by assimilating the interior observations. As a preliminary feasibility study, a set of ideal experiments with the model‐generated pseudo‐observations of surface currents are performed to invert the open boundary conditions (OBCs). In the ideal experiments, 14 kinds of bottom topographies and six kinds of predetermined distributions of OBCs are considered to examine their influence on experiment results. The inversion obtained satisfying results and all the predetermined distributions were successfully inverted. Analysis of results suggests the following: in the case where the spatial variation of the OBC distribution is great or the open boundary is close to a rough topography, the results will be comparatively poor, but still satisfactory; both the tidal elevations and currents can be simulated very accurately with the surface currents at several observation points; the assimilation precision could be reliable and able to reflect both of the inversion and simulation results in the whole field. The performance and results of ideal experiments give a preliminary indication that the construction of this model is successful. Copyright © 2011 John Wiley & Sons, Ltd.
Age differences in symptom expression in patients with major depression
Authors: Hybels Celia F. , Landerman Lawrence R. , Blazer Dan G. 
Published: July 2011

ObjectiveThe aim of the study was to compare symptom expression in primarily middle‐aged (<60) and older (60+) patients who were depressed and determine if symptom profiles differed by age.MethodsPatients diagnosed with major depression (N = 664) were screened using the Center for Epidemiologic Studies—Depression scale and sections of the Diagnostic Interview Schedule. Patients were separated into homogeneous clusters based on symptom endorsement using latent class analysis.ResultsOlder patients were less likely to endorse crying spells, sadness, feeling fearful, being bothered, or feeling life a failure but were more likely to endorse poor appetite and loss of interest in sex. Older patients were also less likely to report enjoying life, feeling as good as others, feeling worthless, wanting to die, and thinking about suicide. In two latent class models with depressive symptoms as indicators, three‐class models best fit the data. Profiles supported heterogeneity in symptom expression. Clusters differed by age when other demographic, clinical, health, and social variables were controlled but did not support age‐specific symptom profiles. Overall, older patients had later age of onset, had fewer lifetime spells, were more likely to have ever received electroconvulsive therapy (ECT), and were less likely to have comorbid anxiety. Older patients also had more cognitive impairment, health conditions, and mobility limitations but had higher levels of subjective social support and had experienced fewer stressful life events.ConclusionsThere are age differences in symptom endorsement between younger/middle‐aged and older patients with major depression. The data, however, did not identify a symptom profile unique to late‐life depression. Copyright © 2011 John Wiley & Sons, Ltd.
Oxygen‐dependent delayed fluorescence measured in skin after topical application of 5‐aminolevulinic acid
Authors: Harms Floor A. , de Boon Wadim M. I. , Balestra Gianmarco M. , Bodmer Sander I. A. , Johannes Tanja , Stolker Robert J. , Mik Egbert G. 
Published: July 2011

AbstractMitochondrial oxygen tension can be measured in vivo by means of oxygen‐dependent quenching of delayed fluorescence of protoporphyrin IX (PpIX). Here we demonstrate that delayed fluorescence is readily observed from skin in rat and man after topical application of the PpIX precursor 5‐aminolevulinic acid (ALA). Delayed fluorescence lifetimes respond to changes in inspired oxygen fraction and blood supply. The signals contain lifetime distributions and the fitting of rectangular distributions to the data appears more adequate than mono‐exponential fitting. The use of topically applied ALA for delayed fluorescence lifetime measurements might pave the way for clinical use of this technique. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A fluorescence lifetime spectroscopy study of matrix metalloproteinases‐2 and ‐9 in human atherosclerotic plaque
Authors: Phipps Jennifer E. , Hatami Nisa , Galis Zorina S. , Baker J. Dennis , Fishbein Michael C. , Marcu Laura 
Published: July 2011

AbstractMatrix metalloproteinase (MMP)‐2 and ‐9 play important roles in the progression of atherosclerosis. This study aims to determine whether MMP‐2 and ‐9 content in the fibrotic caps of atherosclerotic plaque is correlated with plaque autofluorescence. A time‐resolved laser‐induced fluorescence spectroscopy (TR‐LIFS) system was used to measure the autofluorescence and assess the biochemical composition of human plaques obtained from carotid endarterectomy. Results presented here demonstrate for the first time the ability to characterize the biochemical composition as it relates to MMP‐2 and ‐9 content in the atherosclerotic plaque cap using a label‐free imaging technique implemented with a fiberoptic TR‐LIFS system. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A new regulator of osteoclastogenesis: Estrogen response element–binding protein in bone
Authors: Chen Hong , Gilbert Linda C , Lu X , Liu Zhaofan , You Shaojin , Weitzmann M Neale , Nanes Mark S , Adams John 
Published: July 2011

Abstract
The heterogeneous nuclear ribonucleoprotein (hnRNP)–like estrogen response element–binding protein (ERE-BP) competes with estrogen receptor α (ERα) for occupancy of estrogen response elements (EREs). Here we report that ERE-BP potently stimulates osteoclastogenesis. ERE-BP mRNA and protein were found to be expressed ubiquitously in bone. Overexpression of ERE-BP in cultured osteoblasts stimulated expression of the receptor activator of NF-κB ligand (RANKL) and decreased osteoprotegerin (OPG). The effect of ERE-BP on RANKL was shown to be transcriptional in transient transfection assay and competed with via the ER. Constitutive expression of ERE-BP increased the sensitivity of cells toward 1,25-dihydroxyvitamin D3 stimulation of RANKL expression. In contrast, knockdown of ERE-BP in stromal ST-2 cells decreased basal RANKL promoter activity. Cocultures of ERE-BP lentivirus–transduced ST-2 cells with spleen monocytes induced formation of multinucleated osteoclasts (OCs) characterized by tartrate-resistant acid phosphatase, calcitonin receptors, and functional calcium resorption from bone slices. Although ERα competed with ERE-BP for an ERE in a dose-dependent manner, ERE-BP was an independent and potent regulator of RANKL and osteoclastogenesis. In preosteoclastic RAW cells, overexpression of ERE-BP increased RANK, upregulated NF-κB signaling, and enhanced differentiation toward a mature OC phenotype independent of RANKL. These results identify ERE-BP as a potent modulator of osteoclastogenesis. We hypothesize that ERE-BP may play a critical role in the regulation of bone homeostasis as a modulator of estrogen sensitivity as well as by direct action on the transcription of critical osteoclastogenic genes. © 2011 American Society for Bone and Mineral Research
The timing of BMD and geometric adaptation at the proximal femur from childhood to early adulthood in males and females: A longitudinal study
Authors: Jackowski Stefan A , Kontulainen Saija A , Cooper David ML , Lanovaz Joel L , Baxter-Jones Adam DG 
Published: July 2011

Abstract
During adolescence, the peak velocity in bone mass accretion preceded the peak velocity of estimated geometry at the hip. Whether this pattern continues into adulthood when maximum values are achieved remains unknown. The purpose of this study was (1) to identify the ages at which peak values of areal BMD (aBMD), cross-sectional area (CSA), and section modulus (Z) occur, (2) to determine the percent of adult peak attained during adolescence, and (3) to determine the relationship between body composition and the timing of the adult peak values.
One-hundred and sixty-five (92 females) individuals' aBMD, CSA, and Z values were assessed serially at the narrow neck (NN), intertrochanter (IT), and shaft (S) using hip structural analysis (HSA). Peak bone values and the ages of attainment were assessed using factorial MANOVA.
In males, aBMDp (NN 19.4 ± 2.7 years, IT 20 ± 3.4 years, and S 21.8 ± 2.8 years) occurred significantly earlier than CSAp at all sites (NN 21.6 ± 3.2 years, IT 21.1 ± 3.4 years, and S 22.3 ± 3.1 years) and earlier than Zp at the NN (22 ± 3.2 years) and IT (21.3 ± 2.9 years). In females, aBMDp (NN 17.9 ± 2.7 years, IT 18.7 ± 3.5 years, and S 19.7 ± 3.3 years) occurred significantly earlier than CSAp at all sites (NN 20.6 ± 3.6 years, IT 19.4 ± 3.9 years, and S 21.0 ± 3.3 years) and earlier than Zp at the NN (20.7 ± 3.4 years) and S (20.6 ± 3.5 years). The changes in bone mass precede changes in geometric CSA, and this timing may be integral for the development and maintenance of bone strength. © 2011 American Society for Bone and Mineral Research
The effect of adding PTH(1–84) to conventional treatment of hypoparathyroidism: A randomized, placebo-controlled study
Authors: Sikjaer Tanja , Rejnmark Lars , Rolighed Lars , Heickendorff Lene , Mosekilde Leif ,   the Hypoparathyroid Study Group
Published: July 2011

Abstract
In hypoparathyroidism, plasma parathyroid hormone (PTH) levels are inadequate to maintain plasma calcium concentration within the reference range. On conventional treatment with calcium supplements and active vitamin D analogues, bone turnover is abnormally low, and BMD is markedly increased. We aimed to study the effects of PTH-replacement therapy (PTH-RT) on calcium-phosphate homeostasis and BMD. In a double-blind design, we randomized 62 patients with hypoparathyroidism to daily treatment with PTH(1–84) 100 µg or similar placebo for 24 weeks as add-on therapy to conventional treatment. Compared with placebo, patients on PTH(1–84) reduced their daily dose of calcium and active vitamin D significantly by 75% and 73%, respectively, without developing hypocalcemia. However, hypercalcemia occurred frequently during the downtitration of calcium and active vitamin D. Plasma phosphate and renal calcium and phosphate excretion did not change. Compared with placebo, PTH(1–84) treatment significantly increased plasma levels of bone-specific alkaline phosphatase (+226% ± 36%), osteocalcin (+807% ± 186%), N-terminal propeptide of procollagen 1 (P1NP; +1315% ± 330%), cross-linked C-telopeptide of type 1 collagen (CTX; +1209% ± 459%), and urinary cross-linked N-telopeptide of type 1 collagen (NTX; (+830% ± 165%), whereas BMD decreased at the hip (−1.59% ± 0.57%), lumbar spine (−1.76% ± 1.03%), and whole body (−1.26% ± 0.49%) but not at the forearm. In conclusion, the need for calcium and active vitamin D is reduced significantly during PTH-RT, whereas plasma calcium and phosphate levels are maintained within the physiologic range. In contrast to the effect of PTH(1–84) treatment in patients with osteoporosis, PTH-RT in hypoparathyroidism causes a decrease in BMD. This is most likely due to the marked increased bone turnover. Accordingly, PTH-RT counteracts the state of overmineralized bone and, during long-term treatment, may cause a more physiologic bone metabolism. © 2011 American Society for Bone and Mineral Research
An integrative study ascertained SOD2 as a susceptibility gene for osteoporosis in Chinese
Authors: Deng Fei-Yan , Lei Shu-Feng , Chen Xiang-Ding , Tan Li-Jun , Zhu Xue-Zhen , Deng Hong-Wen 
Published: July 2011

Abstract
Osteoporosis is characterized by low BMD and has strong genetic determination. However, specific genetic variants influencing BMD and contributing to the pathogenesis of osteoporosis are largely uncharacterized. Current genetic studies in bone, which are aimed at identification of osteoporosis risk genes, are focused mostly on DNA, RNA, or the protein level individually, lacking integrative evidence from the three levels of genetic information flow to confidently ascertain the significance of genes for osteoporosis. Our previous proteomics study discovered that superoxide dismutase 2 (SOD2) in circulating monocytes (CMCs, ie, potential osteoclast precursors) was significantly upregulated at protein level in vivo in Chinese with low versus high hip BMD. Herein, at mRNA level, we found that SOD2 gene expression also was upregulated in CMCs (p &lt; 0.05) in Chinese with low versus high hip BMD. At the DNA level, in 1627 unrelated Chinese subjects, we identified eight single-nucleotide polymorphisms (SNPs) at the SOD2 gene locus that were suggestively associated with hip BMD (peak signal at rs11968525, p = 0.048). Among the eight SNPs, three SNPs (rs7754103, rs7754295, and rs2053949) were associated with the SOD2 mRNA expression level (p &lt; 0.05), suggesting that they are expression quantitative trait loci (eQTLs) regulating SOD2 gene expression. In conclusion, this integrative evidence from DNA, RNA, and protein levels support SOD2 as a susceptibility gene for osteoporosis. © 2011 American Society for Bone and Mineral Research
Dickkopf-1 regulates bone formation in young growing rodents and upon traumatic injury
Authors: Li Xiaodong , Grisanti Mario , Fan Wei , Asuncion Frank J , Tan Hong-Lin , Dwyer Denise , Han Chun-Ya , Yu Longchuan , Lee Jae , Lee Edward , Barrero Mauricio , Kurimoto Pam , Niu Qing-Tian , Geng Zhaopo , Winters Aaron , Horan Tom , Steavenson Shirley , Jacobsen Frederick , Chen Qing , Haldankar Raj , Lavallee Jennifer , Tipton Barbara , Daris Mark , Sheng Jackie , Lu Hsieng S , Daris Kristi , Deshpande Rohini , Valente Eliane G , Salimi-Moosavi Hossein , Kostenuik Paul J , Li Ji , Liu Min , Li Chaoyang , Lacey David L , Simonet W Scott , Ke Hua Zhu , Babij Philip , Stolina Marina , Ominsky Michael S , Richards William G 
Published: July 2011

Abstract
The physiological role of Dickkopf-1 (Dkk1) during postnatal bone growth in rodents and in adult rodents was examined utilizing an antibody to Dkk1 (Dkk1-Ab) that blocked Dkk1 binding to both low density lipoprotein receptor-related protein 6 (LRP6) and Kremen2, thereby preventing the Wnt inhibitory activity of Dkk1. Treatment of growing mice and rats with Dkk1-Ab resulted in a significant increase in bone mineral density because of increased bone formation. In contrast, treatment of adult ovariectomized rats did not appreciably impact bone, an effect that was associated with decreased Dkk1 expression in the serum and bone of older rats. Finally, we showed that Dkk1 plays a prominent role in adult bone by mediating fracture healing in adult rodents. These data suggest that, whereas Dkk1 significantly regulates bone formation in younger animals, its role in older animals is limited to pathologies that lead to the induction of Dkk1 expression in bone and/or serum, such as traumatic injury. © 2011 American Society for Bone and Mineral Research
Proton magnetic resonance spectroscopy in patients with symptomatic unilateral internal carotid artery / middle cerebral artery stenosis or occlusion
Authors: Zhang Miao , Lu Jie , Jiao Liqun , Ma Qingfeng , Li Kuncheng 
Published: July 2011

AbstractPurpose:To explore the value of proton magnetic resonance spectroscopy imaging (1H‐MRSI) in patients with stenosis or occlusion of the internal carotid artery (ICA) / middle cerebral artery (MCA).Materials and Methods:Fifty noninfarcted patients with stenosis or occlusion of unilateral ICA/MCA were included in our study. In the meantime, 25 patients with cerebral infarction and 25 healthy control subjects were enrolled. All patients and healthy control subjects underwent 1H‐MRSI. Cerebral metabolic changes were studied in the noninfarcted patients and compared with the infarcted patients as well as healthy control subjects.Results:In 50 noninfarcted patients N‐acetylaspartate (NAA) decreased and choline increased in the ischemic hemisphere compared with the contralateral side and control subjects. Lactate peaks were observed in 12 patients. The metabolic changes were relatively slight but were associated with metabolic disruption in infarcted patients. There were relationships between metabolic abnormalities and neurological status of the noninfarcted patients.Conclusion:1H‐MRSI can demonstrate abnormal metabolic changes in cerebral tissues with no infarction, while with ICA/MCA may show stenosis or occlusion at an early stage, which may help guide treatment decisions and preoperative evaluation. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.
Gas‐phase basicities of polyfunctional molecules. Part 2: Saturated basic sites
Authors: Bouchoux Guy , Salpin Jean‐Yves 
Published: July 2011

AbstractThe present article is the second part of a general overview of the gas‐phase protonation thermochemistry of polyfunctional molecules. The first part of the review (Mass Spectrom. Rev., 2007, 26:775–835) was devoted to the description of the physico‐chemical concepts and of the methods of determination, both experimental and theoretical, of gas‐phase basicity. Several clues concerning the structural and energetic aspects of the protonation of isolated species have been emphasized. In the present article, specific examples are examined. The field of investigation is limited to molecules containing a “saturated” basic site, that is, nitrogen or oxygen atoms engaged in simple σ bonds with their neighboring. Aliphatic, cyclic and aromatic poly‐amines, aminoalcohols, alcohols, ethers, and hydroxyl‐ethers, are successively presented. © 2011 Wiley Periodicals, Inc. Mass Spec Rev 31:353–390, 2012
Quantifying the impact of adding gap filling radar data on forecaster wind assessments, warnings, and confidence
Authors: Rude Don J. , Bass Ellen J. , Philips Brenda 
Published: July 2011

AbstractExperimental weather radars are being developed that could enhance the severe weather warning process by providing higher resolution data sensed closer to the ground and with faster update rates. Because wind speed is an important criterion in the issuance of severe thunderstorm warnings, this research investigates the impact of adding these new data to the forecaster decision‐making process. In a static case review setting, 30 National Weather Service (NWS) forecasters evaluated six convective weather cases under two conditions: (1) using (conventional) WSR‐88D weather radar data, and, (2) using both WSR‐88D and additional data from an experimental four‐radar network. Forecasters' predictions of ground level wind gusts, 2–5 min into the future, were compared to measurements from ground‐based wind sensors. When provided with the additional radar data participants significantly improved the accuracy of their wind speed assessments (absolute error reduced from 5.9 m s−1 to 4.0 m s−1; p < 0.001), increased their assessment confidence ratings (p < 0.001), forecasted significantly greater wind speeds (20.4 m s−1 as opposed to 17.1 m s−1; p < 0.001), and increased the number of affirmative decisions to warn from 15 to 35 (p = 0.001). While the addition of high resolution, low altitude, rapidly updating radar data is shown to have both qualitative and quantitative benefits, training and warning policy implications for the incorporation of new technology must also be carefully considered as increased accuracy, confidence and higher wind speed estimates may lead to more warnings. Copyright © 2011 Royal Meteorological Society