bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and microwave‐assisted catalytic activity of novel bis‐benzimidazole salts bearing furfuryl and thenyl moieties in Heck and Suzuki cross‐coupling reactions
Authors: Yılmaz Ülkü , Şireci Nihat , Deniz Selma , Küçükbay Hasan 
Published: February 2010

AbstractA mixture of bis‐benzimidazole salts (1–7), Pd(OAc)2 and K2CO3 in DMF H2O catalyzes, in high yield, the Suzuki and Heck cross‐coupling reactions assisted by microwave irradiation in a short time. In particular, the yields of the Heck and Suzuki reactions with aryl bromides were found to be nearly quantative. The synthesized bis‐benzimidazole salts (1–7) were identified by 1H13C NMR, IR spectroscopic methods and micro analysis. Copyright © 2010 John Wiley & Sons, Ltd.
Synthesis and Self‐Aggregation of Enantiopure and Racemic Molecular Tweezers Based on the Bicyclo[3.3.1]nonane Framework
Authors: Wallentin Carl‐Johan , Wixe Torbjörn , Wendt Ola F. , Bergquist Karl‐Erik , Wärnmark Kenneth 
Published: February 2010

AbstractA pair of molecular tweezers (syn‐4) that consists of quinoline and pyrazine units fused to a bicyclic framework is presented. The tweezers were synthesised both as a racemic mixture (rac‐4) and an enantiomerically pure form ((R,R,R,R)‐4) starting from either racemic or enantiomerically pure bicyclo[3.3.1]nonane‐2,6‐dione (3). Homochiral dimers were observed in the solid state for rac‐4. The self‐association of both rac‐4 and (R,R,R,R)‐4 was studied in solution. A weak self‐association constant in CDCl3 was estimated by 1H NMR spectroscopic dilution titration experiments in both cases, following several proton resonances. For this purpose, a general normalisation model for the accurate determination of association constants from multiple datasets was developed. In contrast to the solid state, no diastereomeric discrimination was observed for rac‐4 in solution.
Dichloro‐Bis(aminophosphine) Complexes of Palladium: Highly Convenient, Reliable and Extremely Active Suzuki–Miyaura Catalysts with Excellent Functional Group Tolerance
Authors: Bolliger Jeanne L. , Frech Christian M. 
Published: February 2010

AbstractDichloro‐bis(aminophosphine) complexes are stable depot forms of palladium nanoparticles and have proved to be excellent Suzuki–Miyaura catalysts. Simple modifications of the ligand (and/or the addition of water to the reaction mixture) have allowed their formation to be controlled. Dichlorobis[1‐(dicyclohexylphosphanyl)piperidine]palladium (3), the most active catalyst of the investigated systems, is a highly convenient, reliable, and extremely active Suzuki catalyst with excellent functional group tolerance that enables the quantitative coupling of a wide variety of activated, nonactivated, and deactivated and/or sterically hindered functionalized and heterocyclic aryl and benzyl bromides with only a slight excess (1.1–1.2 equiv) of arylboronic acid at 80 °C in the presence of 0.2 mol % of the catalyst in technical grade toluene in flasks open to the air. Conversions of >95 % were generally achieved within only a few minutes. The reaction protocol presented herein is universally applicable. Side‐products have only rarely been detected. The catalytic activities of the aminophosphine‐based systems were found to be dramatically improved compared with their phosphine analogue as a result of significantly faster palladium nanoparticle formation. The decomposition products of the catalysts are dicyclohexylphosphinate, cyclohexylphosphonate, and phosphate, which can easily be separated from the coupling products, a great advantage when compared with non‐water‐soluble phosphine‐based systems.
Conditional survival estimates improve over time for patients with advanced melanoma
Authors: Xing Yan , Chang George J. , Hu Chung‐Yuan , Askew Robert L. , Ross Merrick I. , Gershenwald Jeffrey E. , Lee Jeffrey E. , Mansfield Paul F. , Lucci Anthony , Cormier Janice N. 
Published: February 2010

AbstractBACKGROUND:Conditional survival (CS) has emerged as a clinically relevant measure of prognosis for cancer survivors. The objective of this analysis was to provide melanoma‐specific CS estimates to help clinicians promote more informed patient decision making.METHODS:Patients with melanoma and at least 5 years of follow‐up were identified from the Surveillance Epidemiology and End Results registry (1988‐2000). By using the methods of Kaplan and Meier, stage‐specific, 5‐year CS estimates were independently calculated for survivors for each year after diagnosis. Stage‐specific multivariate Cox regression models including baseline survivor functions were used to calculate adjusted melanoma‐specific CS for different subgroups of patients further stratified by age, gender, race, marital status, anatomic tumor location, and tumor histology.RESULTS:Five‐year CS estimates for patients with stage I disease remained constant at 97% annually, while for patients with stages II, III, and IV disease, 5‐year CS estimates from time 0 (diagnosis) to 5 years improved from 72% to 86%, 51% to 87%, and 19% to 84%, respectively. Multivariate CS analysis revealed that differences in stages II through IV CS based on age, gender, and race decreased over time.CONCLUSIONS:Five‐year melanoma‐specific CS estimates improve dramatically over time for survivors with advanced stages of disease. These prognostic data are critical to patients for both treatment and nontreatment related life decisions. Cancer 2010. © 2010 American Cancer Society.
Clinical outcomes of systemic therapy for patients with deep fibromatosis (desmoid tumor)
Authors: de Camargo Veridiana Pires , Keohan Mary L. , D'Adamo David R. , Antonescu Cristina R. , Brennan Murray F. , Singer Samuel , Ahn Linda S. , Maki Robert G. 
Published: February 2010

AbstractBACKGROUND:In the current study, the authors examined the outcomes of patients with desmoid tumors who received systemic therapy at a single institution to provide a basis for the examination of newer agents.METHODS:Records of patients with desmoid tumors who were treated with chemotherapy at the study institution were reviewed. The activity of nonsteroidal anti–inflammatory drugs was not addressed. Patients without measurable disease and those receiving therapy could not be documented, and those receiving prophylactic therapy were excluded.RESULTS:A total of 68 patients received 157 lines of therapy. At the time of last follow–up, 9 patients had died, 7 of progressive disease. The cohort was 62% female, with a median age of 32.5 years. Approximately 32% of the patients had Gardner syndrome. The median follow‐up was 63 months, and patients received a median of 2 lines of therapy. An intra‐abdominal primary tumor location was the most common (44%). The greatest Response Evaluation Criteria in Solid Tumors (RECIST) response rate was observed with anthracyclines and hormonal therapy and the lowest response was noted with single‐agent dacarbazine/temozolomide or tyrosine kinase inhibitors, principally imatinib. On multivariate analysis, macroscopic nodular morphology and the presence of Gardner syndrome were the only tumor factors found to be associated with a greater time to disease progression.CONCLUSIONS:Compared with other agents, antiestrogens and anthracycline‐containing regimens appear to be associated with a higher radiological response rate against desmoid tumors. Systemic therapy can be successful in patients with desmoid tumors, and is a viable option in lieu of morbid or disabling surgery. Cancer 2010. © 2010 American Cancer Society.
Comparing large colour‐difference data sets
Authors: Zhu S. Y. , Luo M. R. , Cui G. H. , Li C. J. , Rigg B. 
Published: February 2010

AbstractThis study investigated the differences between different large colour‐difference (LCD) data sets (with a mean ΔE value about 10). Six data sets were studied. For each data set, various CIELAB based colour difference models were derived to fit the data. These models were compared to shed light on the difference between the different data sets. It was found that all data sets have very similar characteristics except for the Munsell data. Detailed investigation showed that the discrepancy is mainly due to the balance between the lightness and chromatic differences used previously for the Munsell data set. It was found that one unit of Munsell Value appears to be three times as large colour difference as one unit of Munsell Chroma at least under the experimental conditions for the data sets studied here. © 2010 Wiley Periodicals, Inc. Col Res Appl, 2011
Construction of Energy Transfer Systems within Nanosized Polymer Micelles and their Fluorescence Modulation Properties
Authors: Chen Jian , Zeng Fang , Wu Shuizhu 
Published: February 2010

AbstractThe nanoparticle‐based fluorescence resonance energy transfer (FRET) systems have recently attracted considerable attention due to some of their advantages; however, these systems are structurally more complicated than that of small molecule systems, and the energy transfer behavior for particle systems has been seldom investigated. In this study, we synthesized a series of ABC triblock copolymers that contain hydrophilic poly(ethylene oxide) (PEO), hydrophobic poly(styrene) (PS) and photochromic poly(2‐(3‐(3′,3′‐dimethyl‐6‐nitrospiro(indoline‐2′,2‐[2H‐1]benzopyran)‐1′‐yl)propanoylo‐xy)ethyl methacrylate) (PSPMA) blocks by using the sequential two‐step atom transfer radical polymerization (ATRP). The amphiphilic micelles made from these copolymers can incorporate a hydrophobic fluorescent dye, the nitrobenzoxadiazolyl derivative (NBD), thus forming a water dispersible energy transfer system with the fluorescent dye NBD as the donor and spiropyran moieties as the potential acceptor. The spectral properties of NBD/triblock copolymers with varied PS block lengths and PSPMA block lengths have been investigated; the results indicate that the length of PS block in triblock copolymers can affect the energy transfer efficiency of the micelle‐based fluorescence modulation system, the micelles with moderate PS block length are preferable for forming FRET system with higher energy transfer efficiency, and short PSPMA blocks (less than 5 repetition units) are enough for efficient energy transfer.
A new approach for fast segment‐based protection in WDM mesh networks
Authors: Lin Yu , Hamza Haitham S. 
Published: February 2010

AbstractWe propose a new approach for developing segment‐based schemes for protection against single link/node failure in wavelength division multiplexing (WDM) mesh networks. In the proposed approach, every request is allocated a pair of link disjoint butmost coupledprimary and backup paths. Two paths are said to be most coupled if they share the maximum number ofend nodesof some existing requests. Coupled paths reduce the total number of hops need to be traversed by a failure signal and, hence, potentially reduces the overall recovery time. We show that the problem of finding a pair of disjoint and most coupled paths is NP‐complete. Accordingly, we propose an efficient and fast protection algorithm called SPXP—Segment Pre‐Cross‐Connected Protection, to allocate disjoint and most coupled paths. The proposed SPXP algorithm reduces the recovery time by ensuring that backup resources are pre‐configured along each backup segment and, hence, is readily available upon a failure. Simulation results for different incremental traffic models and network topologies show that, for most cases, the proposed SPXP exhibits better performance in terms of blocking probability, resource usage, and recovery time compared with existing protection schemes. Copyright © 2010 John Wiley & Sons, Ltd.
Unsupported Copper Nanoparticles in the 1,3‐Dipolar Cycloaddition of Terminal Alkynes and Azides
Authors: Alonso Francisco , Moglie Yanina , Radivoy Gabriel , Yus Miguel 
Published: February 2010

AbstractReadily prepared copper nanoparticles were found to catalyse the 1,3‐dipolar cycloaddition of azides and alkynes up to rates comparable to those of microwave chemistry. Both the preparation of the nanoparticles and the click reaction are carried out under mild conditions, in short reaction times and in the absence of any stabilising additive or ligand. A variety of 1,2,3‐triazoles were prepared in excellent yields. A reaction mechanism was postulated on the basis of different reactivity studies and deuteration experiments. Copper(I) acetylides were demonstrated to be the real intermediate species.
MAP sequence equalization for imperfect frequency selective channel knowledge
Authors: Sellami Noura , Siala Mohamed , Roumy Aline , Kammoun Ines 
Published: February 2010

AbstractThis paper considers the problem of maximuma posteriori(MAP) sequence equalization over a frequency selective channel when the channel is not perfectly known at the receiver. The imperfect channel estimate is provided by a least squares estimator using a training sequence (TS). The derivation of the MAP criterion taking into account the channel estimation error exists in the literature but no direct practical implementation has been proposed. In this paper, we propose an approximate solution to the problem by using an iterative burst‐by‐burst equalizer based on the Expectation Maximisation (EM) algorithm. Simulation results show that the performance of our iterative equalizer is significantly better than the performance of the non‐iterative equalizer which does not take into account the channel estimation error. Copyright © 2010 John Wiley & Sons, Ltd.
Exact and numerical simulation of peristaltic flow of a non‐Newtonian fluid with inclined magnetic field in an endoscope
Authors: Nadeem S. , Akbar Noreen Sher 
Published: February 2010

AbstractIn the present article, we have studied the effects of inclined magnetic field on the peristaltic flow of Jeffrey fluid through the gap between two coaxial inclined tubes. The inner tube is rigid, whereas the outer tube has sinusoidal wave traveling down its wall. The governing equations are simplified using long wave length and low Reynolds number approximations. Exact and numerical solutions have been derived for velocity profile. The expressions for pressure rise and friction force are calculated using numerical integration. Graphical results and trapping phenomenon is presented at the end of the article to see the physical behavior of different parameters. Copyright © 2010 John Wiley & Sons, Ltd.
Combining forecast densities from VARs with uncertain instabilities
Authors: Jore Anne Sofie , Mitchell James , Vahey Shaun P. 
Published: February 2010

AbstractRecursive‐weight forecast combination is often found to an ineffective method of improving point forecast accuracy in the presence of uncertain instabilities. We examine the effectiveness of this strategy for forecast densities using (many) vector autoregressive (VAR) and autoregressive (AR) models of output growth, inflation and interest rates. Our proposed recursive‐weight density combination strategy, based on the recursive logarithmic score of the forecast densities, produces well‐calibrated predictive densities for US real‐time data by giving substantial weight to models that allow for structural breaks. In contrast, equal‐weight combinations produce poorly calibrated forecast densities for Great Moderation data. Copyright © 2010 John Wiley & Sons, Ltd.
Characterization of the latent transforming growth factor ß complex in Bone
Authors: Pfeilschifter Johannes , Bonewald Lynda , Mundy Gregory R. 
Published: February 2010

Abstract
Transforming growth factor ß (TGF-ß) is a 25 kD multifunctional polypeptide with pronounced effects on the proliferation and differentiation of a variety of cells in vitro. TGF-ß is a potent regulator of the activity of cells with the osteoblast phenotype and of isolated osteoclasts. It is released in increased amounts by bone cultures stimulated to resorb. Organ cultures of neonatal mouse calvaria produce TGF-ß as an inert large-molecular-weight complex that must be dissociated to release biologically active TGF-ß (5-8 ng/ml). We have shown recently that stimulated isolated avian osteoclasts release active TGF-ß from this bone-derived biologically latent form. In this report we have characterized this bone latent form of TGF-ß. Only small amounts of active TGF-ß (&lt;0.5 ng/ml) and no free binding protein are detectable in conditioned medium from bone cultures. Active TGF-ß can be detected in acid-treated calvarial conditioned media in which none or only minute amounts could previously be detected. Following incubation at 37°C, this activated TGF-ß gradually loses activity. Cross-linking studies using 125I-labeled TGF-ß show that this loss of activity is due to TGF-ß binding to a protein of approximately 300 kD. The TGF-ß latent complex accumulates in a linear manner and is stable in the presence of serum and the protease trypsin. Increases in temperature and pH extremes dissociate the complex to release active TGF-ß. Decreases in pH result in an exponential increase in TGF-ß activity. Significant activation of the latent TGF-ß was detectable at pH values as high as 4 and 5. Since the osteoclastic microenvironment is acidic during bone resorption, these data suggest that this acidic microenvironment may regulate TGF-ß activity by releasing active TGF-ß from its latent complex
Parathyroid hormone, but not prostaglandin E2, changes the shape of osteoblasts maintained on bone in vitro
Authors: Boyde A. , Jones Sheila J. , Ali Nadire N. , Melhuish Pauline B. , Bennett A. 
Published: February 2010

Abstract
Parietal bones from 2-week-old rats were dissected free from the sutural regions, dura mater, and periosteum, leaving the surface covered with osteoblasts and some osteoclasts. Prostaglandin (PG) production by these “stripped” bones under basal conditions and after exposure to parathyroid hormone (PTH) was measured by radioimmunoassay of the culture medium (minimum essential medium with or without added 10% heat-inactivated fetal calf serum). Cultured specimens were examined by scanning electron microscopy for changes in osteoblast length, orientation, ruffling, and overlap. As demonstrated previously, PTH caused the osteoblasts to elongate, align, and show fewer ruffles compared to controls. PTH increased PG synthesis by the stripped bones. Indomethacin inhibited PG formation but did not affect the osteoblast shape change. PGE2, indomethacin, or both drugs together had no discernible effect on any morphologic features. These findings indicate that PGE2 does not change osteoblast shape and that the cell shape change with PTH is not mediated by endogenous prostanoids.
Iliac bone biopsies at the time of periarticular stress fractures during fluoride therapy: Comparison with pretreatment biopsies
Authors: Schnitzler Christine M. , Mesquita Julia M. , Gear K. Ann , Robson Heather J. , Moodley Gopal P. , Smyth Amelia E. 
Published: February 2010

Abstract
We attempted to establish whether systemic changes in trabecular bone explain the development of stress fractures in the lower limbs during fluoride therapy for osteoporosis. To this end we compared transiliac bone biopsies obtained before treatment with those taken around the time of stress fractures after 14.3 ± 10.9 (SD) months of therapy in six patients (group A). Biopsies from a comparable group of six patients without stress fractures at the time of the second biopsy (after 11.9 ± 2.7 months of treatment) served for comparison (group B). The biopsies were processed undecalcified and examined by routine histomorphometry. The second biopsies did not show any significant improvement in mean bone volume or trabecular architecture. Although the second biopsies in group A had increased erosion surfaces (p &lt; 0.05) and greater osteoid volume (p &lt; 0.05), group B biopsies showed no difference in erosion surfaces but an increase in all osteoid parameters: osteoid volume (p &lt; 0.05), osteoid surface (p &lt; 0.05), and osteoid seam thickness (p &lt; 0.01). We reached the following conclusions: (1) the combination of increased erosion and replacement of removed bone by as yet unmineralized osteoid in the stress fracture group must have weakened bone and allowed the development of stress fractures. (2) Stress fracture patients may have mounted a less vigorous osteoblast response to fluoride than non-stress fracture patients. Under these conditions microfractures are likely to heal poorly and propagate to develop into full stress fractures. (3) Renal failure is a contraindication to fluoride therapy
Effect of theophylline on calcium metabolism and circulating vitamin D metabolites
Authors: CPT Fortenbery Edwin J. , Mcdermott Michael T. , Duncan William E. 
Published: February 2010

Abstract
Theophylline has been shown to induce the hepatic microsomal enzyme system. These same enzymes increase the metabolism of vitamin D and 25-hydroxyvitamin D when induced by chronic barbiturate or phenytoin administration. To assess the long-term effects of theophylline on vitamin D and calcium metabolism, young rats were treated for 4 weeks with constant subcutaneous theophylline infusions. Theophylline-treated animals had a significantly increased urinary calcium excretion (p &lt;0.0001), a significantly decreased total body calcium per gram body weight (p &lt;0.05), and significantly decreased serum 25-hydroxyvitamin D concentrations (p &lt;0.002) when compared to control animals. These alterations in the concentration of 25-hydroxyvitamin D may impair the ability to increase 1,25-dihydroxyvitamin D-dependent intestinal calcium absorption to compensate for excessive urinary calcium losses. These data suggest that theophylline promotes skeletal calcium loss, and its use may be a risk factor for the development of osteopenia in humans.
Effect of parathyroidectomy on aluminum toxicity and azotemic bone disease in the rat
Authors: Rodriguez Mariano , Lorenzo Victor , Felsenfeld Arnold J. , Llach Francisco 
Published: February 2010

AbstractIn maintenance dialysis patients, low-turnover osteomalacia and aplastic bone disease are generally attributed to aluminum toxicity. Both groups of patients have a relative deficiency of PTH. The reason for the development of osteomalacia versus aplastic bone disease is unclear. The present study was performed to evaluate whether parathyroidectomy (PTX) modifies the effect of aluminum administration on bone histology in renal failure. Seven groups of pair-fed rats were studied: normals (N); renal failure (RF); RF + PTX; PTX; RF + aluminum (AL); RF + PTX + AL; and PTX + AL. Aluminum was administered intraperitoneally 5 days/week for 6 weeks. All groups were sacrificed at 6 weeks. Renal failure increased the serum calcium in both the parathyroid intact (RF versus N, 11 + 0.1 versus 10 + 0.3 mg/dl, X + SEM, P &lt; 0.05) and calcium-supplemented PTX groups (PTX + RF versus PTX, 9.7 + 0.2 versus 9.2 + 0.2 mg/dl, P &lt;0.05). After PTX, aluminum administration increased the serum calcium (PTX + AL versus PTX, 9.8 + 0.3 versus 9.2 + 0.2, P &lt; 0.05, and PTX + RF + AL versus PTX + RF, 10.8 + 0.1 versus 9.7 + 0.2 mg/dl, P &lt; 0.05). In rats with renal failure receiving aluminum, PTX decreased osteoid volume and surface but not osteoid thickness. Rats receiving aluminum did not mineralize bone. Additionally, in PTX rats receiving aluminum, renal failure per se increased osteoblast surface, osteoid surface, osteoid volume, and osteoclast number. In conclusion, (1) aluminum administration in the absence of PTH produced a bone disease that resembled aplastic bone disease, (2) both renal failure and aluminum administration independently increased the serum calcium concentration, and (3) in aluminum-loaded rats, the presence of renal failure independent of PTH resulted in an increase in cellular activity and osteoid deposition.