bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sn(OTf)2 as an Effective Lewis Acid in Reactions of Cyclopropyl Ketones with Acetic Anhydride: Application in the Synthesis of a 19‐Nor‐B‐homo Steroid
Authors: Kranz Darius Paul , Meier zu Greffen Aike , El Sheikh Sherif , Neudörfl Jörg Martin , Schmalz Hans‐Günther 
Published: April 2011

AbstractAttempts to convert 3β‐acetoxy‐5,19‐cyclo‐pregna‐6,20‐dione (8) into a cyclocitrinol‐related steroid with a bicyclo[4.4.1]‐undecane AB‐ring substructure through a Lewis acid‐assisted fragmentation failed. Instead, treating 8 with an excess of Ac2O and BF3·Et2O afforded B‐homo steroid 9 in 90 % yield. This unexpected rearrangement is assumed to proceed via an intermediate bicyclobutonium cation. Remarkably, tricyclo[4.4.1.0]undecane‐1‐one (rac‐13), prepared as a model substrate, did not react under the same conditions. However, by screening various Lewis acids, stannous triflate was identified as a particularly efficient reagent for this and related Lewis acid‐assisted ring‐opening reactions of cyclopropyl ketones in the presence of Ac2O, and even catalytic amounts of Sn(OTf)2 (5 mol‐%) proved to be effective.
Electrophilic Cyclizations of 2‐Fluoroalk‐3‐yn‐1‐ones: Room‐Temperature Synthesis of Diversely 2,5‐Disubstituted 3,4‐Fluorohalofurans
Authors: Li Yan , Wheeler Kraig A. , Dembinski Roman 
Published: April 2011

AbstractA 5‐endo‐dig halocyclization of 2‐fluoroalk‐3‐yn‐1‐ones with the use of N‐iodo‐ and N‐bromosuccinimide, in the presence of gold chloride/zinc bromide (5:20 mol‐%, dichloromethane), under ambient conditions, provides a facile method for the synthesis of 2,5‐disubstituted 3‐bromo‐4‐fluoro‐ and3‐fluoro‐4‐iodofurans. The sequential procedure starts atmonofluorination of the alk‐1‐en‐3‐yn‐1‐yl silyl ethers with Selectfluor and proceeds with good overall yields (62–78 %).
A simplified adaptive Cartesian grid system for solving the 2D shallow water equations
Authors: Liang Qiuhua 
Published: April 2011

SUMMARYThis paper presents a new simplified grid system that provides local refinement and dynamic adaptation for solving the 2D shallow water equations (SWEs). Local refinement is realized by simply specifying different subdivision levels to the cells on a background uniform coarse grid that covers the computational domain. On such a non‐uniform grid, the structured property of a regular Cartesian mesh is maintained and neighbor information is determined by simple algebraic relationships, i.e. data structure becomes unnecessary. Dynamic grid adaptation is achieved by changing the subdivision level of a background cell. Therefore, grid generation and adaptation is greatly simplified and straightforward to implement. The new adaptive grid‐based SWE solver is tested by applying it to simulate three idealized test cases and promising results are obtained. The new grid system offers a simplified alternative to the existing approaches for providing adaptive mesh refinement in computational fluid dynamics. Copyright © 2011 John Wiley & Sons, Ltd.
Critical conversations: A call for a nonprocedural “time out”
Authors: Sehgal Niraj L. , Fox Michael , Sharpe Bradley A. , Vidyarthi Arpana R. , Blegen Mary , Wachter Robert M. 
Published: April 2011

AbstractBACKGROUND:Communication failures are an ongoing threat to patient safety. Procedural “time outs” were developed as a method to enhance communication and mitigate patient harm. Nonprocedural settings generate equal risks for communication failure, yet lack a similar communication tool or practice that can be applied, particularly with a patient‐driven focus.INNOVATION:Rapidly changing clinical states and care plans are common in the hospital setting, placing patients at risk for adverse events. Certain junctures allow for the highest potential of patient harm—at the time of admission, at a change in clinical condition, and at the time of discharge. Direct communication among healthcare providers at these junctures, which we have dubbed Critical Conversations, can provide an opportunity to clarify plans of care, address or anticipate concerns, and foster greater teamwork. Information exchanged during Critical Conversations includes a combination of checklist‐type items and more open‐ended questions but they ultimately create a structure and expectation for communication.LESSONS LEARNED:Integration of Critical Conversations into practice requires provider education and buy‐in, as well as expectations for them to occur. Monitoring adherence, capturing stories of success, and demonstrating effectiveness may enhance implementation and continuous improvement in the process.CONCLUSIONS:Communication tools designed to reduce the likelihood of patient harm remain a focus of patient safety efforts. Critical Conversations are an innovative communication tool, intervention, and policy that potentially limits communication failures at critical junctures to ensure high quality and safe patient care. Journal of Hospital Medicine 2011. © 2011 Society of Hospital Medicine.
Reliability of a point‐based VTE risk assessment tool in the hands of medical residents
Authors: Beck Michael J. , Haidet Paul , Todoric Krista , Lehman Erik , Sciamanna Chris 
Published: April 2011

AbstractBACKGROUND:Venous thromboembolic events (VTE) are a significant cause of mortality in hospitalized medical and surgical patients. Despite recommendations and guidelines, current evidence demonstrates that VTE prophylaxis remains underutilized in at‐risk patients. The process of providing VTE prophylaxis begins with assessing each patient's VTE risk. Using an individualized, point‐based protocol in the assessment process is a complex task, and might contribute to variability in VTE prescribing behavior. There are no published data on how reliably residents can perform risk assessment and prophylaxis using a point‐based VTE risk assessment tool.OBJECTIVE:Our aim was to determine inter‐rater reliability of a point‐based risk assessment tool by residents early in the academic year.DESIGN:The design was a cross‐sectional‐cohort observational study.SETTING:The site was an academic medical center.PATIENTS:Case‐based clinical vignettes were used.INTERVENTIONS:Verbal instructions were given to medical residents about how to apply our hospital's point‐based VTE risk assessment tool.MEASUREMENTS:Interobserver agreement was measured of: 1) risk score, 2) risk‐stratification, 3) identification of contraindications, 4) VTE prophylaxis plan, and 5) resident adherence to the protocol.RESULTS:The intra‐class correlation (ICC) for the total risk score was 0.66 and the kappa coefficient for risk stratification was 0.51. The kappa scores for absolute and relative contraindications were 0.29 and 0.23, respectively. The kappa score for the VTE plan was 0.28.CONCLUSIONS:We determined that, following brief instructions early in the academic year, a point‐based VTE risk assessment tool has only fair to moderate inter‐rater reliability, with suboptimal adherence to the protocol. Both might lead to underutilization of VTE prevention strategies. Journal of Hospital Medicine 2011. © 2011 Society of Hospital Medicine.
Serum sickness‐like reaction with clarithromycin
Authors: Sohail Muhammad Adnan , Nasir Junaid , Ikram Umaira , Genese Thomas 
Published: April 2011

AbstractSerum sickness‐like reaction is a rare immunological condition which may develop following exposure to certain drugs such as penicillins, cephalosporins, and trimethoprim‐sulfamethoxazole, among many others. It is described classically as a type III hypersensitivity response to heterologous proteins. Its true mechanism is still unclear. We present a case of serum sickness‐like reaction to clarithromycin, a commonly prescribed drug for the treatment of respiratory tract infections. The patient had been taking this drug for 3 days when she experienced generalized body aches, rash, arthralgia, and shortness of breath, prompting presentation to the emergency department. Laboratory studies showed decreased C4 and total complement with a slightly elevated sedimentation rate. After exclusion of other possible causes, the diagnosis of serum sickness‐like reaction was made. The patient responded well to nonsteroidal antiinflammatory medication, antihistamines, and a short, tapering dose of steroids. To our knowledge, serum sickness‐like reaction to clarithromycin has never been reported previously. This case emphasizes the need for increased clinical awareness of such an adverse outcome to clarithromycin use. Journal of Hospital Medicine 2011. © 2011 Society of Hospital Medicine.
Local and global climate signals from tree rings of Parkinsonia praecox in La Guajira, Colombia
Authors: Ramírez Jorge Andrés , del Valle Jorge Ignacio 
Published: April 2011

AbstractLand use change and climate change have been increasingly contributing to loss or reduction of biological and economic productivity of arid lands. The dry climate and physiographic characteristics of the Peninsula of La Guajira on the Colombian Caribbean coast are considered to be crucial drivers of the loss of vegetative cover and soil erosion; however, little knowledge exists on long‐term changes in climate in the area. This study presents a tree‐ring chronology from Parkinsonia praecox (18 trees, 45 radii) that allows the reconstruction of local and global climate drivers spanning the last 63 years. Tree‐ring width was strongly correlated with rainfall and wind data, indicating that annual tree growth was closely related to local climatic variability. The chronology also strongly correlated with an index of ENSO severity (El Niño Southern Oscillation), suggesting that large‐scale climatic phenomenon also have important influence on Parkinsonia growth. To further investigate rainfall‐growth relationships, climate data series of annual rainfall and rainfall from September to November (SON), the rainiest months, were reconstructed using transfer functions. These data series did not exhibit a clear trend of change in rainfall over the last 63 years. The transfer functions reconstructed the total annual rainfall (R2 = 0.8), and SON (R2 = 0.7). This study constitutes the first attempt to reconstruct climatic patterns in Colombia with techniques of dendrochronology, and demonstrates the potential of Parkinsonia praecox for studying climatic patterns along the American subtropics, ranging from Mexico to Argentina. Copyright © 2011 Royal Meteorological Society
Prognostic impact and therapeutic implications of sentinel lymph node micro‐metastases in early‐stage breast cancer patients
Authors: Viehl Carsten T. , Langer Igor , Guller Ulrich , Zanetti‐Dällenbach Rosanna , Moch Holger , Wight Edward , Oertli Daniel , Zuber Markus 
Published: April 2011

AbstractThe prognostic value of sentinel lymph node (SLN) micro‐metastases and the question whether patients with SLN micro‐metastases should undergo axillary lymph node dissection remain a matter of great debate. Based on the current literature and on our own data, we provide suggestive evidence that SLN micro‐metastases in early stage breast cancer patients appear to have prognostic value and should impact the decision‐making regarding adjuvant therapy, however, do not necessarily require further surgical treatment. J. Surg. Oncol. 2011;103:531–533. © 2011 Wiley‐Liss, Inc.
Translational/personalized medicine, pharmaco/surgico/radiogenomics, lymphatic spread of cancer, and medical ignoromes
Authors: Witte Marlys H. 
Published: April 2011

AbstractIn the elusive quest for “personalized” cancer treatments based on pharmacogenomics, diverse challenges must be overcome: questionable validity of “molecular models of life,” obstacles to bidirectional translation of scientific advances from bench to bedside to community, and limitations of bioinformatics to recognize and deal with “ignoramics/ignoromes” (expanding unknowns in cancer biology, theranostics, and therapeutic choices). These considerations apply to lymphatic system functioning—lymphatic vessels, lymph, lymph nodes, and lymphocytes—in diseases like cancer. J. Surg. Oncol. 2011;103:501–507. © 2011 Wiley‐Liss, Inc.
Cutaneous melanoma: A model to study cancer metastasis
Authors: Leong Stanley P.L. , Gershenwald Jeffrey E. , Soong Seng‐jaw , Schadendorf Dirk , Tarhini Ahmad A. , Agarwala Sanjiv , Hauschild Axel , Soon Christopher W.M. , Daud Adil , Kashani‐Sabet Mohammed 
Published: April 2011

AbstractNodal status in melanoma is a critically important prognostic factor for patient outcome. The survival rate drops to <10% when melanoma has spread beyond the regional lymph nodes and includes visceral involvement. In general, the process of melanoma metastasis is progressive in that dissemination of melanoma from the primary site to the regional lymph nodes occurs prior to systemic disease. The goal of this review article is to describe melanoma as a clinical model to study cancer metastasis. A future challenge is to develop a molecular taxonomy to subgroup melanoma patients at various stages of tumor progression for more accurate targeted treatment. J. Surg. Oncol. 2011;103:538–549. © 2011 Wiley‐Liss, Inc.
Systemic treatment of early breast cancer—a biological perspective
Authors: Greenberg Sally , Stopeck Alison , Rugo Hope S. 
Published: April 2011

AbstractBreast cancer is the most common non‐skin cancer affecting women worldwide. In the United States, over 90% of tumors are diagnosed as either in situ or localized to the breast or regional lymph nodes. Surgical treatment and adjuvant radiotherapy play an important role in loco‐regional treatment of early stage breast cancer. Systemic adjuvant therapy is targeted towards isolated circulating and/or disseminated tumor cells to prevent systemic recurrence. This review will describe the diverse tumor biology of human breast cancer and how it influences decisions with regard to the use of adjuvant therapies. J. Surg. Oncol. 2011;103:619–626. © 2011 Wiley‐Liss, Inc.
A novel approach to automation of dynamic hollow fiber liquid‐phase microextraction
Authors: Esrafili Ali , Yamini Yadollah , Ghambarian Mahnaz , Moradi Morteza , Seidi Shahram 
Published: April 2011

AbstractAn automated dynamic two‐phase hollow fiber microextraction apparatus combined with high‐performance liquid chromatography was developed for extraction and determination of chlorophenoxy acid (CPA) herbicides from environmental samples. The extraction device, called TT‐extractor, consists of a polypropylene hollow fiber mounted inside a stainless steel tube by means of two tee‐connectors in flow system. An organic solvent, which fills the lumen and the pores of the hydrophobic fiber, is pumped through the fiber repeatedly and the sample is pumped along the outer side of the fiber. The factors affecting the dynamic hollow fiber liquid‐phase microextraction (DHF‐LPME) of target analytes were investigated and the optimal extraction conditions were established. To test the applicability of the designed instrument, CPAs were extracted from environmental aqueous samples. The limits of detection (LODs) as low as 0.5 μg/L, linear dynamic range in the range of 1–100 μg/L and the relative standard deviations of <7% were obtained. The developed method can provide perconcentration factors as large as 230. A hollow fiber membrane can be used at least 20 times with neither loss in the efficiency nor carryover of the analytes between runs. The system is cheap and convenient and requires minimal manual handling.
Tertiary Amine Methacrylate‐Based ABC Triblock Copolymers: Synthesis, Characterization, and Self‐Assembly in both Aqueous and Nonaqueous Media
Authors: Bütün Vural , Taktak Fadime Fulya , Tuncer Cansel 
Published: April 2011

AbstractWater soluble poly[2‐(diisopropylamino)ethyl methacrylate]‐block‐poly[2‐(dimethylamino) ethyl methacrylate]‐block‐poly[2‐(N‐morpholino)ethyl methacrylate] triblock copolymers are synthesized via group transfer polymerization. They are molecularly soluble in acidic solution but give PDPA‐core three‐layer “onion‐like” micelles in alkaline solution. They also give two types of micelles in hexane depending on whether a cosolvent is used: i) PMEMA‐core “onion‐like” reverse micelles are formed with a cosolvent, or, ii) [PDMA‐b‐PMEMA]‐core core–shell micelles without. In addition, novel shell cross‐linked micelles and reverse SCL micelles are also synthesized by cross‐linking the inner PDMA shell of both PDPA‐core micelles in water and PMEMA‐core reverse micelles in hexane. magnified image
Wavelet BEM for large‐scale Stokes flows based on the direct integral formulation
Authors: Xiao Jinyou , Ye Wenjing 
Published: April 2011

AbstractThis paper describes a new wavelet boundary element method (WBEM) for large‐scale simulations of three‐dimensional Stokes problems. It is based on a Galerkin formulation and uses only one set of wavelet basis. A method for the efficient discretization and compression of the double‐layer integral operator of Stokes equation is proposed. In addition, a compression strategy for further reducing the setting‐up time for the sparse system matrix is also developed. With these new developments, the method has demonstrated a high matrix compression rate for problems with complicated geometries. Applications of the method are illustrated through several examples concerning the modeling of damping forces acting on MEMS resonators including a cantilever resonator oscillating in an unbounded air and a perforated plate resonator oscillating next to a fixed substrate. The numerical results clearly illustrate the efficiency and accuracy of the developed WBEM in these large‐scale Stokes flow simulations. Copyright © 2011 John Wiley & Sons, Ltd.
The role of statistical power analysis in quantitative proteomics
Authors: Levin Yishai 
Published: April 2011

AbstractDesigning an experiment for quantitative proteomic analysis is not a trivial task. One of the key factors influencing the success of such studies is the number of biological replicates included in the analysis. This, along with the measured variation will determine the statistical power of the analysis. Presented is a simple yet powerful analysis to determine the appropriate sample size required for reliable and reproducible results, based on the total variation (technical and biological). This approach can also be applied retrospectively for the interpretation of results as it takes into account both significance (p value) and quantitative difference (fold change) of the results.
Novel sulfonated block copolymer containing pendant alkylsulfonic acids: Syntheses, unique morphologies, and applications in proton exchange membrane
Authors: Lee Hsing‐Chieh , Lim Herman , Su Wei‐Fang , Chao Chi‐Yang 
Published: April 2011

AbstractIn this article, we report the syntheses and characterizations of a series of novel block polyelectrolytes, poly(styrene‐block‐sulfonated hydroxystyrene) (PS‐b‐sPHS), containing pendant sulfonic acid groups attached to the backbone via propyl spacers in the sPHS domain. PS‐b‐sPHS with various compositions were synthesized via anionic polymerization and the following analogous chemistry to achieve accurate control of molecular weight (Mw), narrow polydispersity and high degree of sulfonation. Proton exchange membranes (PEMs) were prepared from PS‐b‐sPHS with sulfonic acids in either potassium salts or tetra‐alkylammonium salts via solvent casting and following treatments. Some unique morphologies, such as hallow channels and lamellar arrangement of strings of beads, were observed as a consequence of equilibrium between microphase separation and columbic interactions between polyelectrolytes. The transportation properties were found to closely relate to the morphologies of the PEMs. The combination of microphase separation of block polyelectrolytes and freedom of movement of pendent alkylsulfonic acids was demonstrated to effectively enhance the proton transport and suppress the methanol crossover for the PEMs, leading to the selectivity higher than Nafion 117 by five times at most. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
A green approach toward oleic‐ and undecylenic acid‐derived polyurethanes
Authors: González‐Paz R. J. , Lluch C. , Lligadas G. , Ronda J. C. , Galià M. , Cádiz V. 
Published: April 2011

AbstractNaturally occurring oleic and undecylenic acids were used as raw materials for the synthesis of novel polyurethanes (PUs). The application of environmentally friendly thiol‐ene additions to 10‐undecenoate and oleate derivatives was studied with the goal of obtaining renewable diols. The resulting monomers were then polymerized with 4,4′‐methylenebis (phenylisocyanate), in N,N‐dimethylformamide solution using tin (II) 2‐ethylhexanoate as catalyst, to produce the corresponding thermoplastic PUs (TPUs). Also, ultrasound irradiation has been tested to improve the synthesis of PU. Under these conditions, TPUs were obtained in high yields (80–99%) with weight‐average molecular weights in the 36–83 kDa range. The chemical structures of PUs were assessed by FTIR and NMR spectroscopy. The thermal and mechanical properties of the synthesized TPUs have been studied and they showed a clear dependence on the structure of the parent diol. MTT test was carried out to asses the potential cytotoxicity of the prepared PUs, indicating no cytotoxic response. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
A fully biobased epoxy resin from vegetable oils: From the synthesis of the precursors by thiol‐ene reaction to the study of the final material
Authors: Stemmelen M. , Pessel F. , Lapinte V. , Caillol S. , Habas J.‐P. , Robin J.‐J. 
Published: April 2011

AbstractA novel vegetable oil‐based polyamine issued from grapeseed oil (GSO) was prepared using cysteamine chloride (CAHC) by thiol‐ene coupling (TEC). The structure of the polyamine oil (AGSO) was carefully examined using a large range of chemical analyses (FTIR, 1H NMR and 13C NMR, LC‐MS…). The effects of the amination of GSO on the vegetable oil properties were also studied using viscosimetry. Then, AGSO was employed as a novel curing agent for bio‐based epoxy resin. The thermal crosslinking reaction between AGSO and epoxidized linseed oil (ELO) was studied by DSC and rheology. This study also dealt with the definition of the thermomechanical properties of the final material obtained by the mixing and curing of AGSO with ELO in stoichiometric proportions. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Infrared dielectric mirrors based on thin film multilayers of polystyrene and polyvinylpyrrolidone
Authors: Bailey James , Sharp James S. 
Published: April 2011

AbstractThin film polymer multilayers were prepared by spin coating alternating layers of polystyrene and polyvinylpyrrolidone. Samples with 10, 20, 30, 40, and 50 layers were prepared with individual layer thickness values in the range 223–508 nm. These samples were measured using a Fourier transform infrared spectrometer and were found to display narrow photonic band gaps (∼ 0.04 to 0.06 μm wide) in their spectral response over the wavelength range 1.6 − 2.6 μm. The position of the photonic band gaps was controlled by varying the thickness of the individual layers within the multilayer structures. This was achieved by varying the spin speed used during the deposition of the polymer layers. The peak reflectance of the multilayers was controlled by varying the number of layers within the multilayer samples giving values in the range 20–80% (corresponding to transmittances of 80–20%). Calculated transmittance spectra were also obtained using an optical transfer matrix method. These calculated spectra were shown to be in good agreement with the experimental data obtained. These experiments demonstrate a facile approach to the production of low cost dielectric mirrors that have tailored photonic properties over a range of wavelengths that are currently important for applications in fibre optic based telecommunications. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011