bluuebunny/crossref_metadata_2025_split huggingface dataset:
Device closure of muscular ventricular septal defects in infants less than one year of age using the Amplatzer devices: Feasibility and outcome
Authors: Diab Karim A. , Cao Qi‐ Ling , Mora Bassem N. , Hijazi Ziyad M. 
Published: June 2007

AbstractObjectives:In this study, we evaluated the feasibility, safety, and outcome of device closure of muscular ventricular septal defects (mVSD) in infants less than 1 year of age using the Amplatzer devices.Background:Closure of mVSDs continues to represent a surgical challenge with significant morbidity. Hence, device closure is becoming an attractive and reliable alternative. However, little is known about the feasibility of this procedure in small infants.Methods:Between July 1999 and September 2006, device closure of mVSD was attempted in 20 infants ranging in age from 3 days to 12 months (median ± SD; 4.6 ± 3.8) and in weight from 3.2 to 8.9 kg (4.6 ± 1.9) under TEE guidance by percutaneous or hybrid (perventricular) techniques. The size of the VSD as assessed by TEE ranged from 3 to 11 mm (6.0 ± 2.2) and the Qp:Qs ratio ranged from 0.7 to 8.8 (2.8 ± 2.3).Results:The device was successfully placed in 19/20 infants and it ranged in size from 4 to 14 mm (8.0 ± 2.6). It was percutaneously deployed in 11/19 and by the hybrid approach in 8/19. There were 30 devices placed in 19 infants with multiple devices placed in 5/19 infants. Fluoroscopy times ranged from 11 to 136 min (41 ± 28) and procedure times ranged from 57 to 291 min (178 ± 68). The success rate as defined by complete closure or a trivial shunt was 84% immediately and 100% at 1‐year follow‐up. Major complications occurred in 4/20 patients: wire perforation and hemopericardium (n = 1), device migration (n = 1), transient electromechanical dissociation (n = 1), and mediastinitis (n = 1). At a median follow‐up of 3.8 years, all patients improved and had no hemodynamically significant VSDs. No major complications were encountered in patients with multiple devices.Conclusion:In infants less than 1 year of age, percutaneous and perventricular device closure of mVSDs is technically feasible and highly effective with low morbidity. Long term safety and efficacy needs to be assessed. © 2007 Wiley‐Liss, Inc.
Percutaneous selective pulmonary artery bands (Joeys) in a pulmonary overcirculation model
Authors: Boucek Mark M. , Chan Kak‐Chen , Bright Janice M. 
Published: June 2007

AbstractBackground:Control of distal pulmonary artery (PA) pressure and flow is a critical step in palliating infants with complex congential heart disease. Surgical procedures to protect or isolate the pulmonary circulation carry significant risk and can be unpredictable. Interventional control of pulmonary pressure/flow with an intravascular device (band) could reduce risk and improve regulation of pulmonary flow.Methods:Internal pulmonary bands were created from woven nitinol to create an internal orifice estimated to reduce distal pulmonary arterial pressure by 50%. Two designs were tested, a single eccentric lumen and two symmetrical lumens. The devices were approximately 7‐mm long and the external diameter varied to suit the pulmonary arterial lumen size. A total of 15 devices were implanted in seven lambs with a stented ductus arteriosus to create high pulmonary pressure/flow. Four lambs were followed with devices and stent in place for a mean of 37 ± 13 days.Results:Fourteen of 15 devices were successfully implanted. One was acutely removed since the size was too large. Both device designs created greater than a 50% reduction in distal pulmonary pressure. Main PA pressure was 70/38, mean 50 ± 13 mm Hg, and distal PA pressure 25/16, mean 20 ± 7 mm Hg (P < 0.05). Angiography demonstrated protection of the internal banded pulmonary segments from overcirculation. Late follow‐up showed that the device lumen(s) remained patent. Histology showed the vessel media to be intact but there was intimal proliferation where the device approximated the wall. There were no thrombotic emboli detected.Conclusion:Percutaneous internal banding of the pulmonary arteries was feasible and successful in lambs with high pulmonary flow/pressure analogous to infants with complex congenital heart disease. © 2007 Wiley‐Liss, Inc.
Contemporary management of acute lower extremity ischemia following percutaneous coronary and cardiac interventional procedures using femoral access—A case series and discussion
Authors: Klein Andrew J. , Messenger John C. , Casserly Ivan P. 
Published: June 2007

AbstractNew onset of acute lower extremity ischemia following percutaneous coronary and cardiac interventional procedures using femoral access is an important clinical entity that requires emergent assessment to determine the precise etiology and institute appropriate therapy. We report four cases of this clinical event from our catheterization laboratories that serve to highlight the most frequent etiologies, the importance of immediate diagnostic angiography, and the potential for endovascular techniques to effectively manage this complication. © 2007 Wiley‐Liss, Inc.
Endovascular treatment of intra‐aortic balloon pump‐induced acute limb ischemia
Authors: Klein Andrew J. , Messenger John C. , Casserly Ivan P. 
Published: June 2007

AbstractThe development of acute limb ischemia in patients following intra‐aortic balloon pump (IABP) placement remains a frequent event that presents a significant management challenge. We report two recent cases of this clinical event from our institution, which demonstrate that endovascular therapies may be used to treat acute limb ischemia in this setting without requiring removal of the IABP. © 2007 Wiley‐Liss, Inc.
Possible Existence of Alkali Metal Orthocarbonates at High Pressure
Authors: Čančarević Željko P. , Schön J. Christian , Jansen Martin 
Published: June 2007

AbstractWe investigate the possible existence of crystalline alkali metal orthocarbonates, A4CO4, where A=Li, Na, K, Rb, and Cs. We study the equilibrium between the possible modifications of the orthocarbonate A4CO4 and the binary mixture of the possible modifications of the alkali oxide A2O and those of the alkali metal carbonate A2CO3 as function of pressure. In all cases, the orthocarbonate should be stable at sufficiently high pressure ranging from 22–32 GPa (Rb4CO4) to 200–220 GPa (Cs4CO4).
Systematic Synthesis of Lanthanide Phosphate Nanocrystals
Authors: Huo Ziyang , Chen Chen , Chu Deren , Li Haohang , Li Yadong 
Published: June 2007

AbstractUniform LnPO4⋅x H2O (Ln=Y, La–Nd, Sm–Lu) nanocrystals that have controllable 0D (spherelike), 1D (rodlike), and 2D (polygonlike) structures have been systematically synthesized by means of a hydrothermal method by using a mixed solvent of water and ethanol. Transmission electron microscopy images and SEAD (selected area electron diffraction) patterns revealed that the products are highly crystalline and have structurally uniform shapes. IR, Raman, and electron energy loss spectroscopies gave spectra that indicated that an amount of oleic acid molecules were presented at the surface of individual nanocrystals. These nanocrystals have hydrophobic surfaces and could be easily dispersed in nonpolar solvents. Moreover, a creditable synthetic mechanism for nucleation, growth, and shape evolution has been proposed. Eu3+ doped products were also prepared by using the same synthetic process. The Eu3+ doped products exhibited an orange‐red luminescence that is ascribed to an electron transition within the 4f shell. Analysis of the photoluminescent spectra revealed that the optical properties are strongly dependent on their morphologies.
High‐Efficiency Electrophosphorescent Copolymers Containing Charged Iridium Complexes in the Side Chains
Authors: Du Bin , Wang Lei , Wu HongBin , Yang Wei , Zhang Yong , Liu RanSheng , Sun MingLiang , Peng Junbiao , Cao Yong 
Published: June 2007

AbstractA convenient approach to novel charged Ir polymers for optoelectronic devices to achieve red emission was developed. 2‐(Pyridin‐2‐yl)benzimidazole units grafted into the side chains of macroligands (PFCz and PFP) served as ligands for the formation of charged Ir complex pendants with 1‐phenylisoquinoline (1‐piq). The charged Ir polymers (PFPIrPiq and PFCzIrPiq) showed exclusive Ir(1‐piq)2{N‐[2‐(pyridin‐2‐yl)benzimidazole]hexyl}+BF4− (IrPiq) emission, with the peak at 595 nm. The best device performances were obtained from PFCzIrPiq4 with the device configuration of ITO/PEDOT:PSS/PFCzIrPiq4+PBD (30 wt %)/TPBI/Ba/Al (PBD: 5‐(4‐tert‐butylphenyl)‐2‐(biphenyl‐4‐yl)‐1,3,4‐oxadiazole; TPBI: 1,3,5‐tris‐(2‐N‐phenylbenzimidazolyl)benzene). A maximum external quantum efficiency (EQE) of 7.3 % and a luminous efficiency (LE) of 6.9 cd A−1 with a luminance of 138 cd m−2 were achieved at a current density of 1.9 mA cm−2. The efficiencies remained as high as EQE=3.4 % and LE=3.3 cd A−1 with a luminance of 3770 cd m−2 at a current density of 115 mA cm−2. The single‐layer devices based on charged Ir polymers also showed high efficiency with the high work‐function metal Ag as cathode. The maximum external quantum efficiencies of the devices were 0.64 % and 0.66 % for PFPIrPiq2 and PFPIrPiq10, respectively. A possible mechanism of an electrochemical cell associated with its electrochemical redox pathway for single‐layer devices has been proposed. The results showed that the charged Ir polymers are promising candidate materials for polymer optoelectronic devices.
New Metal‐Organic Frameworks with Large Cavities: Selective Sorption and Desorption of Solvent Molecules
Authors: Wang Yan , Huang Yong‐Qing , Liu Guang‐Xiang , Okamura Taka‐aki , Doi Mototsugu , Sheng Yue‐Wei , Sun Wei‐Yin , Ueyama Norikazu 
Published: June 2007

AbstractFive novel transition metal complexes [CdII3(tpba‐2)2(SCN)6]⋅6 THF⋅3 H2O (1), [CuII3(tpba‐2)2(SCN)6]⋅6 THF⋅3 H2O (2), [NiII3(tpba‐2)2(SCN)6]⋅6 THF⋅3 H2O (3), [CdII2(tpba‐2)(SCN)3]ClO4 (4), [CuI3(SCN)6(H3tpba‐2)] (5) [TPBA‐2 = N′,N′′,N′′′‐tris(pyrid‐2‐ylmethyl)‐1,3,5‐benzenetricarboxamide, THF=tetrahydrofuran] were obtained by reactions of the corresponding transition metal salts with TPBA‐2 ligand in the presence of NH4SCN using layering or solvothermal method, respectively. The results of X‐ray crystallographic analysis showed that complexes 1, 2 and 3 are isostructural and have the same 2D honeycomb network structure with Kagomé lattice, in which all the MII (M = Cd, Cu, Ni) atoms are six‐coordinated, and the TPBA‐2 ligands adopt cis,cis,cis conformation while the thiocyanate anions act as terminal ligands. Capsule‐like motifs are found in 1, 2 and 3, in which six THF molecules are hosted, and the results of XPRD and solid‐state 13C NMR spectral measurements showed that the compound 1 can selectively desorb and adsorb THF molecules occurring along with the re‐establishment of its crystallinity. In contrast to 1, 2 and 3, complex 4 has different 2D network structure, resulting from TPBA‐2 ligands with cis,trans,trans conformation, thiocyanate anions serving as end‐to‐end bridging ligands, and the incomplete replacement of perchlorate anions, which further link the 2D layers into 3D framework by the hydrogen bonds. In complex 5, the CuII atoms are reduced to CuI during the process of solvothermal reaction, and the CuI atoms are connected by thiocyanate anions to form a 3D porous framework, in which the protonated TPBA‐2 ligands are hosted in the cavities as templates.
Asymmetric Hydrogenation Routes to Deoxypolyketide Chirons
Authors: Zhou Jianguang , Ogle James W. , Fan Yubo , Banphavichit(Bee) Vorawit , Zhu Ye , Burgess Kevin 
Published: June 2007

AbstractAsymmetric hydrogenations of monoenes and dienes were performed to obtain terminal deoxypolyketide fragments A and the corresponding internal chirons B and C. The chiral N‐heterocyclic carbene catalyst 1 was used throughout. Modest selectivities for hydrogenations of simple monoenes relayed into high selectivities for preparations of the terminal deoxypolyketide fragments in which either two hydrogenations or one and an optically pure starting material were used. Curiously, the face selectivities for hydrogenation of α,β‐unsaturated esters were consistently opposite to those that had been observed for styrene and stilbene derivatives in previous work, and to closely related allylic alcohol and ether derivatives in this work. Plausible mechanisms for this differing behavior were deduced by using DFT calculations. It appears that the origin of the unusual stereoselectivity for the ester derivatives is transient metal‐coordination of the ester carbonyl whereas there is no evidence that the allylic alcohol or ethers coordinate. The routes developed to α,ω‐functionalized internal deoxypolyketide fragments are extremely practical. These begin with the Roche ester being converted into alkene and, in one case, diene derivatives. Catalyst control prevails in the hydrogenations of these substrates, but there is a significant “substrate vector” (a term we used to describe the influence of the substrate on a catalyst‐controlled reaction). This is determined by minimization of 1,3‐allylic strain and, in some cases, syn pentane interactions. This substrate vector can be constructively paired with the (dominant) catalyst vector by use of the appropriate enantiomer of 1. In the hydrogenation of a diene derivative, two chiral centers could be formed simultaneously with overall 11:1.0 selectivity; this is the first time this has been achieved in any asymmetric synthesis of a deoxypolyketide fragment. Throughout, diastereoselectivities of the crude material in the syntheses of α,ω‐functionalized internal deoxypolyketide fragments were in excess of 11:1.0 and chromatographically purified samples could be isolated in high yields with dr (dr=diastereomeric ratio) values consistently in excess of 40:1.0.
Control of Electron Transfer in a Conjugated Porphyrin Dimer by Selective Excitation of Planar and Perpendicular Conformers
Authors: Winters Mikael U. , Kärnbratt Joakim , Blades Holly E. , Wilson Craig J. , Frampton Michael J. , Anderson Harry L. , Albinsson Bo 
Published: June 2007

AbstractA donor–acceptor system is presented in which the electron‐transfer rates can be sensitively controlled by means of excitation wavelength and temperature. The electron donor is a butadiyne‐linked zinc porphyrin dimer that is connected to a C60 electron acceptor. The broad distribution of conformations allowed by the butadiyne linker makes it possible to selectively excite perpendicular or planar donor conformers and thereby prepare separate initial states with driving forces for electron transfer that differ by almost 0.2 eV. This, as well as significant differences in electronic coupling, leads to distinctly different rate constants for electron transfer, which in consequence can be controlled by changing excitation wavelength. By extending the system with a secondary donor (ferrocene), a second, long‐range charge‐separated state can be formed. This system has been used to test the influence of conformational heterogeneity on electron transfer mediated by the porphyrin dimer in the ground state. It was found that if the dimer is forced to a planar conformation by means of a bidentate ligand, the charge recombination rate increased by an order of magnitude relative to the unconstrained system. This illustrates how control of conformation of a molecular wire can affect its behaviour.
Micelle‐Induced Versatile Performance of Amphiphilic Intramolecular Charge‐Transfer Fluorescent Molecular Sensors
Authors: Wang Jiaobing , Qian Xuhong , Qian Junhong , Xu Yufang 
Published: June 2007

AbstractA series of amphiphilic intramolecular charge‐transfer fluorescent molecular sensors AS1–3, equipped with a rod‐shaped hydrophobic 2‐phenylbenzoxazole fluorophore and a hydrophilic tetraamide Hg2+‐ion receptor, have been prepared. These sensor molecules could be incorporated into the hydrophobic sodium dodecyl sulfate (SDS) micelle, which is confirmed by the clear spectral blue shift and emission enhancement observed at the critical micelle concentration of SDS. Systematic examination of the sensor–Hg2+ complexation, by using both UV/visible and fluorescence spectroscopy, indicates that SDS significantly modulates both the binding event and signal transformation of these sensor molecules. The potential advantages are fourfold: 1) SDS substantially increases the Hg2+‐ion association constant and results in an amplified sensitivity. 2) SDS initiates spectral features which facilitate Hg2+‐ion analysis, for example, in addition to the strengthened fluorescence of the free sensors AS1–3, the original “on–off” response of AS2 toward the Hg2+ ion is transformed into a self‐calibrated two‐wavelength ratiometric signal, while for AS3, Hg2+‐ion complexation in the presence of SDS results in a 180 nm blue shift, which is preferred to the 51 nm spectral shift obtained without SDS. 3) Thermoreversible tuning of the dynamic detection range is realized. 4) Highly specific Hg2+‐ion identification could be achieved by using the SDS‐induced fingerprint emission (358 nm) of the AS2–Hg2+ complex. Altogether, this work demonstrates a convenient and powerful strategy that remarkably elevates the performance of a given fluorescent molecular sensor. It also implies that for a specific utilization, much attention should be paid to the microenvironment in which the sensor resides, as the behavior of the sensor might be different from that in the bulk solution.
Highly Selective Recognition of Diols by a Self‐Regulating Fine‐Tunable Methylazacalix[4]pyridine Cavity: Guest‐Dependent Formation of Molecular‐Sandwich and Molecular‐Capsule Complexes in Solution and the Solid State
Authors: Gong Han‐Yuan , Wang De‐Xian , Xiang Jun‐Feng , Zheng Qi‐Yu , Wang Mei‐Xiang 
Published: June 2007

AbstractThe molecular recognition of methylazacalix[4]pyridine (MACP‐4; 1) towards various diols was investigated by using 1H NMR spectroscopic and X‐ray diffraction analysis. As a unique macrocyclic host molecule that undergoes conformational inversions very rapidly in solution, MACP‐4 has been shown to self‐regulate its conformation, through the formation of different conjugations of the four bridging nitrogen atoms with their adjacent pyridine rings, to form a cavity that best fits the guest species through intermolecular hydrogen‐bond, CH⋅⋅⋅π, and π–π interactions between the host and guest. As a consequence, depending upon the diol structure and geometry, MACP‐4 forms a 1:1 molecular sandwich, 2:1 molecular capsule, and 1:2 butterfly‐layered complex with the guests. As a result of favorable enthalpy and entropy effects, MACP‐4 exhibits excellent selectivity in the recognition of resorcinol, thus resulting in a very stable 1:1 sandwich complex with resorcinol with a binding constant of 6000 M−1. The dynamic 1H NMR spectroscopic study demonstrated that the 1,3‐alternate conformation of the macrocyclic ring of the MACP‐4⋅resorcinol complex (1⋅3) is stable at low temperature (T<243 K), and its conformational inversion requires a larger activation energy (ΔG≠=(45.5±2.2) kJ mol−1). In the presence of an excess amount of resorcinol, however, the conformational inversion of the MACP‐4⋅resorcinol complex proceeds more readily with a decreased activation energy (ΔG≠=(33.5±1.5) kJ mol−1) owing most probably to the favorable enthalpy effect of the [3⋅⋅⋅1⋅⋅⋅3]≠ transition state.
Phase 2 study of cetuximab in patients with advanced hepatocellular carcinoma
Authors: Zhu Andrew X. , Stuart Keith , Blaszkowsky Lawrence S. , Muzikansky Alona , Reitberg Donald P. , Clark Jeffrey W. , Enzinger Peter C. , Bhargava Pankaj , Meyerhardt Jeffrey A. , Horgan Kerry , Fuchs Charles S. , Ryan David P. 
Published: June 2007

AbstractBACKGROUND.Epidermal growth factor receptor (EGFR) and ligand expression is frequently seen in hepatocellular carcinoma (HCC). A phase 2 study was performed with cetuximab, a chimeric monoclonal antibody that binds specifically to EGFR, in patients with advanced HCC.METHODS.Eligibility criteria included unresectable or metastatic measurable HCC, an Eastern Cooperative Oncology Group performance status ≤2, Cancer of the Liver Italian Program (CLIP) score ≤3, and adequate organ functions. The initial dose of cetuximab was 400 mg/m2 given intravenously followed by weekly intravenous infusions at 250 mg/m2. Each cycle was defined as 6 consecutive weekly treatments. EGFR expression was assayed by immunohistochemistry and trough serum concentrations of cetuximab were determined during the first cycle.RESULTS.Thirty patients were enrolled and assessable for efficacy and toxicity. No responses were seen. Five patients had stable disease (median time, 4.2 months; range, 2.8–4.2 months). The median overall survival was 9.6 months (95% confidence interval [CI], 4.3–12.1 months) and the median progression‐free survival (PFS) was 1.4 months (95% CI, 1.2–2.6 months). The treatment was generally well tolerated. No treatment‐related grade 4–5 toxicities occurred. Grade 3 (according to the National Cancer Institute's Common Terminology Criteria for Adverse Events [version 3.0]) aspartate aminotransferase, hypomagnesemia, and fever without neutropenia were noted in 1 patient (3.3%) each. On Week 6 of Cycle 1, arithmetic mean serum cetuximab concentrations for patients with Child‐Turcotte‐Pugh (CTP) A and CTP B disease were 47.6 mcg/mL and 66.9 mcg/mL, respectively.CONCLUSIONS.Although cetuximab could be safely administered with tolerable toxicity profiles, it demonstrated no antitumor activity in HCC in this phase 2 study. Cetuximab trough concentrations were not notably altered in patients with mild to moderate hepatic dysfunction. © 2007 American Cancer Society. Cancer 2007. ©2007 American Cancer Society.
A discussion on volume change in the plastic phase
Authors: Botta A. S. , Paccola R. R. , Venturini W. S. , Coda H. B. 
Published: June 2007

AbstractThis technical note discusses the possibility of using a more simplified scheme to estimate the plastic multiplier when some material shows volume changes, e.g. soil, balsa wood foam and other similar materials. Two procedures regarding volume changes during the plastic phase are discussed here. The first one is the classic procedure applied to non‐associative plasticity, for which a Drucker–Prager‐like surface is adopted to represent the plastic potential. For the second procedure, the plastic potential is not explicitly known, however, its orthogonal direction is chosen respecting a plastic volume change parameter similar to Poisson's ratio. Copyright © 2007 John Wiley & Sons, Ltd.
Sky blue, but what blue? A new evaluation of the colors of the sky for artists and designers
Authors: Smith Ken 
Published: June 2007

AbstractThis study describes a process of relating the perceptual analysis of the colors of the terrestrial atmosphere to currently available pigments used in artists' painting systems. This process sought to discover how the colors of the sky could be defined and simulated by these pigments. The author also describes how confusion over the bewildering choice of suitable pigments on offer in the market place can be clarified. © 2006 Wiley Periodicals, Inc. Col Res Appl, 32, 249–255, 2007