bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cover Picture: Functionalization of Crystalline Colloidal Arrays through Click Chemistry (Adv. Mater. 21/2007)
Authors: Evanoff D. D. , Hayes S. E. , Ying Y. , Shim G. H. , Lawrence J. R. , Carroll J. B. , Roeder R. D. , Houchins J. M. , Huebner C. F. , Foulger S. H. 
Published: November 2007

AbstractPhotonic crystals based on electrostatically‐stabilized colloidal arrays dispersed in a liquid medium are of interest to materials scientists partly because of the optical tuning afforded to theses systems with a variation in interparticle distance. On p. 3507, Stephen Foulger and co‐workers from Clemson University, USA report on a general strategy for the preparation of well‐defined and regioselectively functionalized ordered colloidal particles through the exploitation of “click” chemistry. Click transformations have found utility in the synthesis and/or functionalization of a range of systems. In addition, the solvochromic tuning of the ordered arrays is employed to modify the emission spectra of the surface‐attached photoluminescent dyes.
Preparation and properties of melt‐processable polyimides based on fluorinated aromatic diamines and aromatic dianhydrides
Authors: Wang Kai , Fan Lin , Liu Jin‐Gang , Zhan Mao‐Sheng , Yang Shi‐Yong 
Published: November 2007

AbstractTwo series of melt‐processable polyimides were prepared from 4,4′‐bis(3‐amino‐5‐trifluoromethylphenoxy)biphenyl (m‐6FBAB) and 4,4′‐bis(4‐amino‐5‐trifluoromethylphenoxy) biphenyl (p‐6FBAB) with various aromatic dianhydrides. The effects of the chemical structures of the polyimides on their properties, especially the melt processability and organic solubility, were investigated. The experimental results demonstrate that some of the fluorinated aromatic polyimides showed good melt processability at elevated temperatures (250–360°C) with relatively low melt viscosities and could be melt‐molded to produce strong and tough polyimide sheets. Meanwhile, the polyimides showed excellent organic solubility in both polar aprotic solvents and common solvents to give stable polyimide solutions with high polymer concentrations and relatively low viscosities. Thus, we prepared high‐quality polyimide films by casting the polyimide solutions on glass plates followed by baking at relatively low temperatures. The polyimides derived from m‐6FBAB showed better melt processability and solubility than the p‐6FBAB based polymers. The melt‐processable polyimides showed a good combination of thermal stability and mechanical properties, with decomposition temperatures of 547–597°C, glass‐transition temperatures in the range 205–264°C, tensile strengths of 81.3–104.9 MPa, and elongations at break as high as 19.6%. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation of hydrogels composed of poly(vinyl alcohol) and polyethyleneimine and their electrical response
Authors: Kie Shim Jin , Ryong Oh Seng , Bong Lee Sang , Cho Kye Min 
Published: November 2007

AbstractSemi‐ and full‐interpenetrating polymer network (IPN) hydrogels composed of poly(vinyl alcohol) and polyethyleneimine (PEI) were prepared to investigate the bending behavior under the electric response. To find out the characteristics of the hydrogel in the medium, swelling ratio, and rate and water state of the hydrogels were measured. The swelling ratio of the semi‐IPN hydrogels increased with PEI content in the matrix, whereas that of full‐IPN hydrogels dramatically decrease with increase of PEI contents in the hydrogels. In the water state of hydrogel, the bound water and free water of semi‐IPN hydrogels increased with PEI weight ratio. The full‐IPN hydrogels show the lower free water content in comparison with the semi‐IPN hydrogel. The IPN hydrogels exhibited bending angle change in response to external stimulus such as voltage, the bending angle increased with PEI concentration. In addition, the repeated bending behaviors according to the magnitude of the applied electric field revealed that the bending angle is reversible without collapse of formation of hydrogel in all samples. Thus, the hydrogels will be useful as novel modulation systems in the field of artificial organ and matrix for drug delivery. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis of microphase‐separated poly(styrene‐co‐sodium styrene sulfonate) membranes using amphiphilic urethane acrylate nonionomers as an reactive compatibilizer
Authors: Kim Ju‐Young , Mulmi Suresh , Lee Chang‐Hyun , Lee Young‐Moo , Ihn Kyo‐Jin 
Published: November 2007

AbstractMicrophase‐separated poly(styrene‐co‐sodium styrene sulfonate) random copolymer (PSSU) membranes were fabricated through a new copolymerization process. Two immiscible monomers, styrene and sodium styrene sulfonate were dissolved in a single solvent and formed homogeneous solutions, which were directly converted to wall‐to‐wall membranes via radical copolymerization process with microphase separation. Since urethane acrylate nonionomer (UAN) chain has amphiphilicity as well as reactivity with vinyl monomers, UAN chain could act not only as compatibilizer for polystyrene and poly(sodium styrene sulfonate), but also as macrocrosslinker, which makes it possible for the formation of crosslinked copolymer of two immiscible polymers without macrophase separation. TEM image of the PSSU membranes showed that nanosized hydrophilic domains formed by hydrophilic/hydrophobic microphase separation were dispersed at hydrophobic matrix phase. PSSU membranes fabricated using UAN chain having longer chain length of polyethylene oxide showed bigger size of hydrophilic domains, which was also confirmed by TEM images. Fabricated PSSU membranes showed proton conductivity higher than 10−2 S/cm and methanol permeability lower than 10−7 cm2/s of Nafion® 117 membranes. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008
Consistent model predictions for isothermal cure kinetics investigation of high performance epoxy prepregs
Authors: Zhang Jin , Fox Bronwyn , Guo Qipeng 
Published: November 2007

AbstractAn accurate kinetics model is essential for understanding the curing mechanism and predicting the end properties of polymer materials. Graphite/epoxy AS4/8552 prepreg is a recent high‐performance thermosetting composite modified with thermoplastic, which is being used in the manufacture of aircraft and military structures. The isothermal cures of this system along with another thermoplastic toughened high‐performance prepreg, the T800H/3900‐2 system, were investigated by real‐time Fourier transform infrared (FTIR) spectroscopy. The cure rate was quantitatively analyzed based on the concentration profiles of both the epoxy and primary amine groups. Three autocatalytic models were used to determine kinetics parameters for both composite systems. The model which utilizes an empirical term, the final relative conversion (at different isothermal curing temperatures), describes the experimental data of both systems more satisfactorily than the model which applies a diffusion factor. The modeling results suggest that the curing of epoxy within both prepregs can be assumed to be a second order process. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008
A Zeolite‐Like Zinc Phosphonocarboxylate Framework and Its Transformation into Two‐ and Three‐Dimensional Structures
Authors: Chen Zhenxia , Zhou Yaming , Weng Linhong , Yuan Chao , Zhao Dongyuan 
Published: November 2007

AbstractThree zinc phosphonocarboxylates, Zn2(pbc)2⋅Hdma⋅H3O⋅2H2O (1), Zn(pbc)⋅Hdma (2), and Zn4.5(pbc)3(OH)(H2O)0.5⋅Hdma (3) (H3pbc=4‐phosphonobenzoic acid, dma=dimethylamine) were synthesized by the mixed solvothermal reaction of Zn(Ac)2⋅2H2O and 4‐phosphonobenzoic acid in N,N‐dimethylformamide (DMF) and water. The zigzag and ladderlike chains completely constructed by triply fused 4‐membered rings (denoted SBU‐1) are linked by the organic moieties to form the 3D zeolite‐like structure 1 and the layered structure 2, respectively. As for structure 3, a new second building unit (SBU‐2) formed by the inset of the [Zn3O12] trimer into the 4‐membered ring as well as SBU‐1 is observed. The connections between the two types of SBUs lead to a “zinc phosphate” layer, which is linked by the organic groups to generate a 3D pillar‐layered structure. Both solution‐mediated and solid‐state transformations of 1 to 2 and 3 were observed. A possible mechanism for the transformation is proposed. Gas sorption studies show that 1 has accessible pores for methanol and water and exhibits size selectivity for alcohols.
Highly Diastereoselective Friedel–Crafts Alkylation Reactions via Chiral α‐Functionalized Benzylic Carbocations
Authors: Stadler Daniel , Bach Thorsten 
Published: November 2007

AbstractA series of chiral 1‐aryl‐1‐alkanols, which carry different functional groups (FGs) at the 2‐position, were subjected to an acid (HBF4)‐catalyzed reaction with various arenes. An SN1 substitution reaction was observed, in the course of which 1,1‐diarylalkanes were formed. In most cases (40 out of 51 reactions), yields were very good to excellent (75–99 %). The diastereoselectivity of the reaction was heavily dependent on the FG at the 2‐position. If the FG was methoxycarbonyl, nitro, hydroxy, cyano, trimethylsilylethynyl, or chloro, the corresponding anti products were favored and with a decreasing preference in this order. The methoxycarbonyl‐substituted substrates gave the anti products with diastereomer ratios (d.r.) that exceeded 92:8 (16 examples). Nitro‐ and hydroxy‐substituted products were obtained in most instances with d.r.≥90:10, whereas cyano‐, trimethylsilylalkynyl‐, or chloro‐substituted substrates delivered only with certain arenes products with high selectivity (d.r.≥90:10). The sterically more demanding FGs ethylsulfonyl, ethoxysulfonyl, and diethoxyphosphonyl induced diastereofacial selectivity in favor of the corresponding syn products, with diethoxyphosphonyl being the most effective. The substrate with FG=PO(OEt)2 delivered, with eight different arenes, the corresponding syn substitution products (d.r.=80:20 – >95:5). The relative configuration of the products was elucidated by spectroscopic and synthetic methods. On selected examples, the reactions were shown to proceed stereoconvergently, under kinetic control, and without racemization. Depending on the functional group, the onset of the reactions between 2‐methylthiophene and some representative alcohols was found to occur at a temperature Θ between −78 and −40 °C. There was no correlation between the selectivity and Θ. A model is suggested to explain the facial diastereoselectivity based on a preferred conformation of the putative intermediate carbocation.
A Note on P ‐values for Two‐sided Tests
Authors: Finner Helmut , Strassburger Klaus 
Published: November 2007

AbstractBased on uniformly most powerful unbiased (UMPU) tests for two‐sided hypotheses and a short note in Lehmann (1959) on critical levels for randomized tests, Meulepas (1998, 1999) proposed (two‐tailed) P ‐values taking into account the randomization constant(s) of the UMPU‐tests. While UMPU‐tests need an extra uniform observation if randomization is required, the P ‐values proposed by Meulepas need no extra uniform observation. At first glance, his idea looks very promising in order to define a suitable and powerful P ‐value. Unfortunately, such P ‐values are generally too conservative. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Atlanta Classification of acute pancreatitis revisited
Authors: Bollen T L , van Santvoort H C , Besselink M G , van Leeuwen M S , Horvath K D , Freeny P C , Gooszen H G 
Published: November 2007

Abstract

Background
In a complex disease such as acute pancreatitis, correct terminology and clear definitions are important. The clinically based Atlanta Classification was formulated in 1992, but in recent years it has been increasingly criticized. No formal evaluation of the use of the Atlanta definitions in the literature has ever been performed.

Methods
A Medline literature search sought studies published after 1993. Guidelines, review articles and their cross-references were reviewed to assess whether the Atlanta or alternative definitions were used.

Results
A total of 447 articles was assessed, including 12 guidelines and 82 reviews. Alternative definitions of predicted severity of acute pancreatitis, actual severity and organ failure were used in more than half of the studies. There was a large variation in the interpretation of the Atlanta definitions of local complications, especially relating to the content of peripancreatic collections.

Conclusion
The Atlanta definitions for acute pancreatitis are often used inappropriately, and alternative definitions are frequently applied. Such lack of consensus illustrates the need for a revision of the Atlanta Classification.
Transcatheter closure of atrial septal defect without balloon sizing
Authors: Wang Jou‐Kou , Tsai Shen‐Kou , Lin Shu‐Man , Chiu Shuenn‐Nan , Lin Ming‐Tai , Wu Mei‐Hwan 
Published: November 2007

AbstractObjective: To evaluate the safety and feasibility of transcatheter closure of atrial septal defect (ASD) without balloon sizing. Methods: A total of 243 patients (group I), aged 2.1–76 years (median 22 years), underwent transcatheter closure of ASD without balloon sizing. The maximal diameter of the defect was measured on transesophageal echocardiographic (TEE) images. The size of device selected was generally 4–6 mm and 5–8 mm larger than the maximal diameter, if the defect was <14 mm and ≥14 mm, respectively. The results of ASD closure in group I were compared with those of 271 patients (group II, median age 11 years) who underwent ASD closure with balloon sizing prior to the study period. Results: Of the 243 patients in group I, the maximal defect diameter ranged from 5.2 to 37 mm (mean 17.5 ± 6.6 mm, median 17 mm). A total of 247 Amplatzer septal occluders were deployed in 240 patients. Two patients were found to develop distal embolization of a device the next day. Therefore, failure occurred in five patients. Comparing the results between group I and group II, there was no significant difference in success rate (238/243 vs. 263/271), incidence of embolization (2/243 vs. 2/271) and complete closure rate at 3‐month follow‐up (94.1% vs. 95.8%). There is significant difference in mean age (26.6 ± 20.2 vs. 19.1 ± 17.6), maximal defect diameter (17.5 ± 6.6 vs. 14.1 ± 5.9 mm) and Qp/Qs ratio (2.77 ± 1.11 vs. 2.48 ± 0.97) between group I and II. The mean diameter of device used was significantly larger in group I than in group II (23.1 ± 8.1 vs. 19.6 ± 7 mm, P < 0.001). Conclusions: Balloon sizing may not be necessary in transcatheter closure of ASD. © 2008 Wiley‐Liss, Inc.
Classification of coronary artery bifurcation lesions and treatments: Time for a consensus!
Authors: Louvard Yves , Thomas Martyn , Dzavik Vladimir , Hildick‐Smith David , Galassi Alfredo R. , Pan Manuel , Burzotta Francisco , Zelizko Michael , Dudek Darius , Ludman Peter , Sheiban Imad , Lassen Jens F. , Darremont Olivier , Kastrati Adnan , Ludwig Josef , Iakovou Ioannis , Brunel Philippe , Lansky Alexandra , Meerkin David , Legrand Victor , Medina Alfonso , Lefèvre Thierry 
Published: November 2007

AbstractBackground: Percutaneous coronary intervention (PCI) of coronary bifurcation lesions remains a subject of debate. Many studies have been published in this setting. They are often small scale and display methodological flaws and other shortcomings such as inaccurate designation of lesions, heterogeneity, and inadequate description of techniques implemented. Methods: The aim is to propose a consensus established by the European Bifurcation Club (EBC), on the definition and classification of bifurcation lesions and treatments implemented with the purpose of allowing comparisons between techniques in various anatomical and clinical settings. Results: A bifurcation lesion is a coronary artery narrowing occurring adjacent to, and/or involving, the origin of a significant side branch. The simple lesion classification proposed by Medina has been adopted. To analyze the outcomes of different techniques by intention to treat, it is necessary to clearly define which vessel is the distal main branch and which is (are) the side branche(s) and give each branch a distinct name. Each segment of the bifurcation has been named following the same pattern as the Medina classification. The classification of the techniques (MADS: Main, Across, Distal, Side) is based on the manner in which the first stent has been implanted. A visual presentation of PCI techniques and devices used should allow the development of a software describing quickly and accurately the procedure performed. Conclusion: The EBC proposes a new classification of bifurcation lesions and their treatments to permit accurate comparisons of well described techniques in homogeneous lesion groups. © 2008 Wiley‐Liss, Inc.
An analysis of door‐to‐balloon time in a single center to determine causes of delay and possibilities for improvement
Authors: Wu Eugene B. , Arora Nipun , Eisenhauer Andrew C. , Resnic Frederic S. 
Published: November 2007

AbstractObjectives: We analyzed door‐to‐balloon times in our institution to identify those factors which significantly prolong time to treatment in ST elevation myocardial infarction (STEMI). Background: Recent data have shown that patients with myocardial infarction transferred from one institution to another for PCI and those presenting outside of normal working hours suffer considerably prolonged door‐to‐balloon times. Methods: We analyzed the door‐to‐balloon time and its components from January 2005 to March 2006 in 167 consecutive patients presenting with STEMI to determine which variables were associated with delays. Results: The median door to balloon (DTB) time of all patients was 127 min. DTB was 62 min (P = 0.001) for patients presenting directly during working hours, 111.5 min for patients presenting directly during on‐call hours, 157.5 min for patients presenting to outside hospitals during working hours and 149 min for patients transferred from outside hospitals during on‐call hours. Factors that significantly lengthened DTB time included presentation during on‐call hours (P = 0.007), outside hospital presentation (<0.001), prolonged time from chest pain onset to presentation (P = 0.004), absence of chest pain on presentation (P = 0.01), and cardiac arrest before PCI (P = 0.05). Conclusion: In our center, transport time and on‐call hour delays account for the majority of reperfusion delay. Other factors that influenced delay were atypical presentation without chest pain, borderline ST changes, or delayed presentation. Thus, transfer from an outside facility, presentation after working hours, and having a difficult diagnosis all influence the rapidity of treatment. The implementation of an in‐house STEMI response team may reduce the process induced delays and improve door‐to‐balloon times. © 2008 Wiley‐Liss, Inc.
Different strategies of retrograde approach in coronary angioplasty for chronic total occlusion
Authors: Saito Shigeru 
Published: November 2007

AbstractBackground:Retrograde approach through the collateral channels has been recently proposed and has the potential to improve the success rate of percutaneous coronary intervention (PCI) in chronic total occlusion (CTO) lesions of the coronary arteries.Methods:The author performed retrograde approach for CTO lesions in 45 patients from January 2006 to January 2007 at different medical institutions worldwide. The details of the techniques were examined retrospectively.Results:The septal branch route was used in 93% of the cases. The author classified the strategies into six types after the successful crossing of a guidewire into the target artery distal to the CTO lesion through the collateral channels. Among them, “Just landmark,” “Controlled antegrade and retrograde subintimal tracking,” and “Proximal true lumen puncture” strategies were used most frequently (32, 27, and 30%, respectively). The retrograde guidewires could be successfully passed distal to the CTO lesion in 37 patients (82%), among them the final PCI success was achieved in 31 patients, yielding the PCI success by pure retrograde approach of 69%. The final success rate among 45 patients including 42 patients with previous failed attempts was 84% (38 patients). There were no serious complications related to the retrograde approach.Conclusions:Retrograde approach with different strategies, mainly through septal arteries, can provide a high success rate with PCI, as shown in 83% of patients with previous failed attempts at traditional PCI for CTO lesions, with there being no serious complications. More experience of this technique and its refinement are required for further improvement of PCI techniques for CTO lesions. © 2008 Wiley‐Liss, Inc.
Late target lesion revascularization after implantation of sirolimus‐eluting stent
Authors: Hong Myeong‐Ki , Mintz Gary S. , Lee Cheol Whan , Park Duk‐Woo , Lee Seung‐Whan , Kim Young‐Hak , Jung In‐Hyun , Kim Sang‐Hyun , Cheong Sang‐Sig , Kim Jae‐Joong , Park Seong‐Wook , Park Seung‐Jung 
Published: November 2007

AbstractObjectives: We evaluated the incidence, clinical presentation, and angiographic in‐stent restenosis (ISR) pattern of late target lesion revascularization (TLR) after sirolimus‐eluting stent (SES) implantation. Background: Late TLR is an unusual finding beyond 6–9 months after bare‐metal stent implantation. However, late TLR after SES implantation has not been sufficiently evaluated. Methods: The study population consisted of 804 patients with 1,020 native lesions that were patent at 6‐month follow‐up angiogram after SES implantation. Results: Late TLR was performed in 18 patients with 18 lesions (1.8%) at 24.1 ± 2.6 months (range; 18–30 months) after SES implantation. Clinical presentation of late TLR patients was silent ischemia in eight patients and recurrent angina in 10 patients, but none had an acute coronary syndrome. Angiographic ISR pattern of late TLR lesions were focal ISR in 12 lesions (67%) and diffuse ISR in six lesions (33%). Serial quantitative coronary angiographic analysis of these lesions showed a minimal lumen diameter of 2.6 ± 0.5 mm immediately after SES implantation, 2.4 ± 0.4 mm at 6‐month follow‐up and 0.7 ± 0.6 mm at 24‐month follow‐up (ANOVA P < 0.001). By stepwise multiple logistic regression analysis, the only independent predictor of late TLR was stent length (P < 0.001, OR = 1.040, 95% CI = 1.019–1.061). Conclusions: Late TLR was performed in 1.8% of 1,020 native lesions that were patent at 6‐month follow‐up angiogram. Clinical presentations of late TLR was either silent ischemia or recurrent angina, but not acute coronary syndrome. Two‐thirds of late TLR lesions had a focal angiographic ISR pattern. © 2007 Wiley‐Liss, Inc.