bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fast enzymatic saccharification of switchgrass after pretreatment with ionic liquids
Authors: Zhao Hua , Baker Gary A. , Cowins Janet V. 
Published: November 2009

AbstractThe pretreatment of cellulose using ionic liquids (ILs) has been shown to be an effective method for improving the enzymatic hydrolysis of cellulose; this technique affords a fast and complete saccharification of cellulose into reducing sugars (Dadi et al., Biotechnol Bioeng. 2006; 95:904–910; Liu and Chen, Chinese Sci Bull. 2006; 51:2432–2436; Zhao et al., J Biotechnol. 2009; 139:47–54). Motivated by these advances, this study examines the effect of IL‐pretreatment on the enzymatic hydrolysis of purified xylan (as a model system of hemicellulose) and switchgrass (as a real lignocellulose). The IL‐pretreatment resulted in no improvement in the hydrolysis of xylan. The likely reason is that pure xylan has a low degree of polymerization (DP), and is readily biodegraded even without any pretreatment. However, in real cellulosic materials (such as switchgrass), xylan is entrapped within the cellulosic matrix, and cannot be conveniently accessed by enzymes. Our data demonstrate that the IL‐pretreatment of switchgrass significantly improved the enzymatic saccharification of both cellulose (96% D‐glucose yield in 24 h) and xylan (63% D‐xylose yield in 24 h). The compositional analysis of switchgrass suggests a lower lignin content after IL‐pretreatment. In addition, the infrared spectrum of regenerated switchgrass indicates a lower substrate crystallinity, whereas the enzyme adsorption isotherm further implies that the regenerated substrate is more accessible to enzymes. This study has further confirmed that IL‐pretreatment is an effective tool in enhancing the enzymatic hydrolysis of cellulosic biomass, and allowing a more complete saccharification. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Antibody‐immobilized column for quick cell separation based on cell rolling
Authors: Mahara Atsushi , Yamaoka Tetsuji 
Published: November 2009

AbstractCell separation using methodological standards that ensure high purity is a very important step in cell transplantation for regenerative medicine and for stem cell research. A separation protocol using magnetic beads has been widely used for cell separation to isolate negative and positive cells. However, not only the surface marker pattern, e.g., negative or positive, but also the density of a cell depends on its developmental stage and differentiation ability. Rapid and label‐free separation procedures based on surface marker density are the focus of our interest. In this study, we have successfully developed an antiCD34 antibody‐immobilized cell‐rolling column, that can separate cells depending on the CD34 density of the cell surfaces. Various conditions for the cell‐rolling column were optimized including graft copolymerization, and adjustment of the column tilt angle, and medium flow rate. Using CD34‐positive and ‐negative cell lines, the cell separation potential of the column was established. We observed a difference in the rolling velocities between CD34‐positive and CD34‐negative cells on antibody‐immobilized microfluidic device. Cell separation was achieved by tilting the surface 20 degrees and the increasing medium flow. Surface marker characteristics of the isolated cells in each fraction were analyzed using a cell‐sorting system, and it was found that populations containing high density of CD34 were eluted in the delayed fractions. These results demonstrate that cells with a given surface marker density can be continuously separated using the cell rolling column. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010
An anatomic study on the junctura tendinum in the 4th intermetacarpal space and its clinical implication
Authors: Jeon In‐Ho , Seok Joon‐Ho , Park Il‐Hyung , Choi Jin‐Won , Min Woo‐Kie , Kwon Dong‐Soo , Kim Hyo‐Jin , Kim Poong‐Taek 
Published: November 2009

AbstractWe report results of anatomic study in the fourth intermetacarpal space, focusing on the pattern of junctura tendinum and variations of extensor tendons of the little finger with its clinical implication on snapping of the little finger. Fifty unpaired cadaveric hands were dissected from the wrist to the middle phalanx of the ring and little fingers. The type of junctura tendinum was judged based on Von Schroder's classification and the relationship with EDC were recorded. EDC to the little finger and EDM were dissected and the numbers were recorded. Forty six hands (92%) exhibited a junctura tendinum in the fourth intermetacarpal space and it was Type III in 42 hands (84%). The EDC‐little finger was absent in 76% (38 of 50 hands). When present, EDC‐little finger originated most commonly as single thin tendon. The absence of an EDC‐little finger was associated with increased incidence of Type III junctura tendinum (37 of 38 hands). An EDM was present in all 50 hands running from the fifth dorsal compartment. Based on these clinical and anatomic studies, we considered that the snapping of the little finger is more likely subluxation of junctura tendinum rather than subluxation/dislocation of EDC of the little finger. Clin. Anat. 23:56–60, 2010. © 2009 Wiley‐Liss, Inc.
Descriptive anatomy of the dominant septal perforators using Dual Source coronary CT angiography
Authors: Brinjikji Waleed , Harris Scott R. , Froemming Adam T. , Christensen Kevin N. , Lachman Nirusha , Araoz Philip A. 
Published: November 2009

AbstractAlthough clinical outcomes for septal ablation in treating left ventricular outflow tract obstructions are generally favorable, a variety of complications have been reported including a high incidence of right bundle branch block. These complications may be attributed to anatomic variability of the dominant septal perforator. We used Dual Source CT Coronary Angiography (DS‐CTA) to determine the location of the termination point of the dominant septal perforator as well as the distance of the termination point from the mitral annulus in patients undergoing DS‐CTA. One‐hundred‐fourteen DS‐CTA scans were retrospectively reviewed by two observers by consensus. The left ventricle was divided into anterior wall, anterioseptum, and inferioseptum. For each segment, the myocardium was divided into three layers (1) right ventricular side, (2) mid portion, and (3) left ventricular side. The zone of termination of the dominant septal perforator was identified as well as the distance of the termination point from the mitral annulus. The dominant septal perforator terminated in the right ventricular side of the anterioseptum in 86 of the 118 visualized terminations (73%) and in the left ventricular anterior wall in 6 visualized terminations (5%). On average, the dominant septal perforator terminated 26.3 ± 8.6 mm from the mitral annulus. In the majority of cases, the dominant septal perforator terminates in the right ventricular side of anterioseptum. In addition, there is great variability in the distribution of the termination point of the dominant septal perforator from the mitral annulus. Clin. Anat. 23:70–78, 2010. © 2009 Wiley‐Liss, Inc.
Anatomical variation in the position of the brachiocephalic trunk (innominate artery) with respect to the trachea: A computed tomography‐based study and literature review of innominate artery compression syndrome
Authors: Fawcett S.L. , Gomez A.C. , Hughes J.A. , Set P. 
Published: November 2009

AbstractRespiratory compromise due to tracheal compression by the brachiocephalic trunk (BT), a condition first labeled as Innominate Artery Compression Syndrome (IACS), has been controversially attributed to an anomalous origin of this vessel to the left of, and hence crossing, the trachea. The aim of this study was to establish the normal relationship between the BT and trachea in infants, children, and young adults without obstructive respiratory symptoms. One hundred and eighty‐one computed tomography (CT) examinations of the thorax, in three age groups, were reviewed. In axial cross section, the origin of the BT from the aortic arch was identified. The BT origin, with respect to the trachea, was recorded as for a clock face, approximated to the nearest half hour. There were 62 CTs in Group 1 (1 day to 3 years of age), 48 CTs in Group 2 (10–15 years), and 71 examinations in Group 3 (20–40 years). In 96.8% of Group 1, 91.7% of Group 2, and 74.6% of Group 3 the BT origin was to the left of the trachea, between the half past twelve and 3 o'clock positions. The BT origin occurred more the left in Group 1 when compared with the other two groups (P< 0.001). An origin of the BT to the left of the trachea is a normal finding in children and young adults without obstructive respiratory symptoms. There is a tendency for the origin to become progressively more rightward with age. Clin. Anat. 23:61–69, 2010. © 2009 Wiley‐Liss, Inc.
The iliolumbar artery—Anatomic considerations and details on the common iliac artery trifurcation
Authors: Rusu M.C. , Cergan R. , Dermengiu D. , Curcă G.C. , Folescu R. , Motoc A.G.M. , Jianu A.M. 
Published: November 2009

AbstractThe iliolumbar artery (ILA) of Haller is the largest nutrient pedicle of the ilium and its detailed knowledge is important for various surgical procedures that approach the lumbosacral junction, the L4/L5 disk space, the sacroiliac joint, the iliac and psoas muscles, or the lumbar spine. Also the ILA is relevant for various techniques of embolization. We aimed to evaluate the anatomic and topographic features of the ILA, by dissection on 30 human adult pelvic halves and on 50 angiograms. ILA was a constant presence and it emerged at Level A (from the common iliac artery (CIA), 8.75%), Level B (from the CIA bifurcation, 2.5%), Level C (from the internal iliac artery (IIA), 52.5%), Level D (from the IIA bifurcation, 3.75%), and Level E (from the posterior trunk of the IIA, 32.5%). Level B of origin of the ILA corresponds to a trifurcated CIA (morphology previously unreported), while Level D corresponds to a trifurcated IIA. A higher origin of the ILA corresponds to a more transversal course of it. A descending lumbar branch that leaves the iliac arterial system independently to enter the psoas major muscle, as seen in 48% of cases, may be misdiagnosed as ILA. Surgical interventions in the lumbar, sacral, and pelvic regions must take into account the variable origins of the ILA from the iliac system that can modify the expected topographical relations and may lead to undesired hemorrhagic accidents. Clin. Anat. 23:93–100, 2010. © 2009 Wiley‐Liss, Inc.
One‐Step Preparation of Multifunctional Chitosan Microspheres by a Simple Sonochemical Method
Authors: Skirtenko Natalia , Tzanov Tzanko , Gedanken Aharon , Rahimipour Shai 
Published: November 2009

AbstractChitosan is a biodegradable natural polymer with great potential for pharmaceutical applications due to its biocompatibility, high charge density, nontoxicity, and mucoadhesion properties. Processing techniques for the preparation of chitosan microspheres have been extensively developed since the 1980s. The present paper describes for the first time a fast and one‐step process for the preparation of stable chitosan microspheres by a simple sonochemical method. The microspheres were characterized by their particle size, surface morphology, stability, and drug‐entrapment efficiency. The average size of the microspheres was found to be around 1 μm with a narrow size distribution, which enabled them to be used for in vivo applications. The encapsulation of different dyes into these microspheres was readily achieved with more than 75 % efficacy by dissolving them into the organic phase before sonication. The chitosan microspheres demonstrated excellent stability toward acidic and basic conditions ranging from pH 4 to 9, thereby indicating their implementation as possible therapeutic and diagnostic agents. The stability of these microspheres appears to be contributed from intermolecular imine cross‐linking in addition to other noncovalent interactions. The ability of the surface‐exposed amino groups of chitosan microspheres to undergo chemical conjugation with potential drugs and/or targeting vectors was determined by their reaction with fluorescein isothiocyanate (FITC) and fluorescamine followed by confocal microscopy.
Syntheses, Optical Properties, and Theoretical Investigation of Silafluorenes and Spirobisilafluorenes Bearing Electron‐Donating Aminostyryl Arms around a Silafluorene Core
Authors: Agou Tomohiro , Hossain Md. Delwar , Kawashima Takayuki 
Published: November 2009

Abstractπ‐Extended silafluorenes and spirobisilafluorenes bearing electron‐donating aminostyryl substituents at the 2,7‐ or 3,6‐positions were synthesized by a Horner–Wadsworth–Emmons reaction. The electronic influence of spirocyclic structure and substitution mode of the aminostyryl substituents was investigated by UV/Vis spectroscopy, which indicated the existence of a spiroconjugation effect in the 3,6‐substituted spirobisilafluorene. They exhibited moderate to strong fluorescence emission, and the fluorescence properties were compatible with the UV/Vis absorption characteristics, except for the 3,6‐substituted spirobisilafluorene, which showed relatively large enhancement of fluorescence quantum yield and Stokes shift. The influence of the spirocyclic structure and substitution mode on the photophysical properties of the silicon compounds was investigated by DFT calculations.
Correlation of the Catalytic Activity for Oxidation Taking Place on Various TiO2 Surfaces with Surface OH Groups and Surface Oxygen Vacancies
Authors: Zheng Zhanfeng , Teo Jaclyn , Chen Xi , Liu Hongwei , Yuan Yong , Waclawik Eric R. , Zhong Ziyi , Zhu Huaiyong 
Published: November 2009

AbstractThree catalytic oxidation reactions have been studied: The ultraviolet (UV) light induced photocatalytic decomposition of the synthetic dye sulforhodamine B (SRB) in the presence of TiO2 nanostructures in water, together with two reactions employing Au/TiO2 nanostructure catalysts, namely, CO oxidation in air and the decomposition of formaldehyde under visible light irradiation. Four kinds of TiO2 nanotubes and nanorods with different phases and compositions were prepared for this study, and gold nanoparticle (Au‐NP) catalysts were supported on some of these TiO2 nanostructures (to form Au/TiO2 catalysts). FTIR emission spectroscopy (IES) measurements provided evidence that the order of the surface OH regeneration ability of the four types of TiO2 nanostructures studied gave the same trend as the catalytic activities of the TiO2 nanostructures or their respective Au/TiO2 catalysts for the three oxidation reactions. Both IES and X‐ray photoelectron spectroscopy (XPS) proved that anatase TiO2 had the strongest OH regeneration ability among the four types of TiO2 phases or compositions. Based on these results, a model for the surface OH group generation, absorption, and activation of molecular oxygen has been proposed: The oxygen vacancies at the bridging O2− sites on TiO2 surfaces dissociatively absorb water molecules to form OH groups that facilitate adsorption and activation of O2 molecules in nearby oxygen vacancies by lowering the absorption energy of molecular O2. A new mechanism for the photocatalytic formaldehyde decomposition with the Au/TiO2 catalysts is also proposed, based on the photocatalytic activity of the Au‐NPs under visible light. The Au‐NPs absorb the light owing to the surface plasmon resonance effect and mediate the electron transfers that the reaction needs.
Reactivity of ortho‐Substituted Aryl–Palladium Complexes towards Carbodiimides, Isothiocyanates, Nitriles, and Cyanamides
Authors: Vicente José , Abad José‐Antonio , López‐Sáez María‐José , Jones Peter G. , Bautista Delia 
Published: November 2009

AbstractComplexes [Pd(C6H3XH‐2‐R′‐5)Y(N^N)] (X=O, NH; Y=Br, I; R′=H, NO2; N^N=N,N,N′,N′‐tetramethylethylenediamine (tmeda), 2,2′‐bipyridine (bpy), 4,4′‐di‐tert‐butyl‐2,2′‐bipyridine (dtbbpy)) react with RNCE (E=NR, S) or RC≡N (R=alkyl, aryl, NR′′2) and TlOTf (OTf=CF3SO3) to give, respectively, 1) products of the insertion of the CE group into the CPd bond, protonation of the N atom, and coordination of X to Pd, [Pd{κ2‐X,E‐(XC6H3{EC(NHR)}‐2‐R′‐4)}(N^N)]OTf or [Pd(κ2‐X,N‐{ZC6H3(NHCR)‐2‐R′‐4})(N^N)]OTf, or products of the coordination of carbodiimides and OH addition, [Pd{κ2‐C,N‐(C6H4{OC(NR)}NHR‐2)}(bpy)]OTf; or 2) products of the insertion of the C≡N group to Pd and N‐protonation, [Pd(κ2‐X,N‐{XC6H3(NHCR)‐2‐R′‐4})(N^N)]OTf.
Synthesis of Highly Efficient Ag@AgCl Plasmonic Photocatalysts with Various Structures
Authors: Wang Peng , Huang Baibiao , Lou Zaizhu , Zhang Xiaoyang , Qin Xiaoyan , Dai Ying , Zheng Zhaoke , Wang Xiaoning 
Published: November 2009

AbstractBy means of a simple ion‐exchange process (using different precursors) and a light‐induced chemical reduction reaction, highly efficient Ag@AgCl plasmonic photocatalysts with various self‐assembled structures—including microrods, irregular balls, and hollow spheres—have been fabricated. All the obtained Ag@AgCl catalysts were characterized by means of X‐ray diffraction, X‐ray photoelectron spectroscopy, scanning electron microscopy, and UV‐visible diffuse reflectance spectroscopy. The effect of the different morphologies on the properties of the photocatalysts was studied. The average content of elemental Ag in Ag@AgCl was found to be about 3.2 mol %. All the catalysts show strong absorption in the visible‐light region. The obtained Ag@AgCl samples exhibit enhanced photocatalytic activity for the degradation of organic contaminants under visible‐light irradiation. The stability of the plasmonic photocatalysts was also investigated in detail.
Evaporation‐Induced Ordered Honeycomb Structures of Gold Nanoparticles at the Air/Water Interface
Authors: Ma Hongmin , Hao Jingcheng 
Published: November 2009

AbstractThe breath figure method was used to prepare dodecanethiol‐capped gold nanoparticle macroporous structures with pore diameters from 1.7 to 3.5 μm on an air/water interface. A two‐step procedure is proposed for the fabrication of these macroporous structures, by forming a surfactant monolayer on water, and drop‐casting a gold nanoparticle dispersion in chloroform onto the surfactant monolayer. The self‐assembled films are easily transferred from the water surface onto different substrates and were characterized by TEM, SEM, and AFM. Ordered honeycomb structures with different pore arrays (perforated monolayer films, hexagonal networks and alveoli‐like porous films) were obtained. The change in morphology is concentration dependent, and deformed structures with elliptic honeycomb networks are also observed. In addition, honeycomb films using gold nanoparticles stabilized by a weakly bound ligand (dioctadecyldimethylammonium chloride) were formed by the same technique. These films have potential as substrates for surface‐enhanced Raman spectroscopy.
Tungsten(VI) and Tungsten(V) Fluoride Complexes
Authors: El‐Kurdi Said , Al‐Terkawi Abdal‐Azim , Schmidt Bernd M. , Dimitrov Anton , Seppelt Konrad 
Published: November 2009

AbstractWF6 reacts with phosphines R3P forming 1:1 compounds. With R=P(CH3)3 the coordination around the tungsten atom is capped trigonal prismatic, with R=P(CH3)2C6H5 the coordination is capped octahedral, as established by single‐crystal structure determinations: [(CH3)3PWF6]: a=752.5(21), b=945.7(24), c=629.8(18) pm. β=110.36(13)°, space group Cm, Z=2; [(CH3)2(C6H5)PWF6]: a=762.2(2), b=1123.5(2), c=2647.5(6) pm, space group Pbca, Z=8. [(CF3CH2)2NWF5] reacts smoothly with P(C6H5)3 forming known P(C6H5)3(F)2 and [(CF3CH2)2NWF4P(C6H5)3], a stable, green, molecular species, identified among other methods with an crystal structure determination: a=914.9(1), b=956.0(1), c=1449.8(2) pm, α=7.642(4), β=81.648(3), γ=81.519°, space group P$\bar 1$, Z=2.
Dispersion‐Oriented Soft Interaction in a Frustrated Lewis Pair and the Entropic Encouragement Effect in its Formation
Authors: Kim Hyun Woo , Rhee Young Min 
Published: November 2009

AbstractThe origin of the stability of a frustrated Lewis pair (FLP) tBu3P:B(C6F5)3 is investigated computationally to demonstrate the importance of the dispersion interaction. To this end, the interaction between alkyl‐substituted phosphines (Me3P and tBu3P) and hexafluorobenzene (C6F6) is first investigated. Driven by the lone‐pair to π‐orbital interaction, the binding energy is found to be even larger than usual π–π interaction energies between small aromatic compounds. This character, which is inherited to fluorophenyl‐substituted B(C6F5)3 in the FLP, induces large flexibility in the FLP over the molecular surface of B(C6F5)3. This soft interaction, in turn, causes an entropic stabilization of the FLP formation in comparison with classical Lewis pairs based on close and tight PB dative bonds. It also suggests a diverse nature of the FLP when it is involved in chemical reactions. Even with the cooperative participation of the perfluorophenyl groups, a detailed inspection of the FLP interaction potential energy surface indicates that the boron atom is still the major interaction site for the pair formation. This non‐negligible direct PB interaction, which is related also to the soft nature of the borane frontier orbital, is further supported by substantial spatial overlap between the frontier orbitals on the phosphine/borane fragments and their interaction energy estimations.
Modeling excess lung cancer risk among screened arm participants in the Mayo Lung Project
Authors: Goldwasser Deborah L. , Kimmel Marek 
Published: November 2009

AbstractBACKGROUND:The Mayo Lung Project (MLP) was a randomized clinical trial designed to test whether periodic screening by chest x‐ray reduced lung cancer (LC) mortality in men who were high‐risk smokers. Among MLP participants, there were more deaths from LC in the screening arm both at the trial's end and after long‐term follow‐up. Overdiagnosis was cited widely as an explanation for the MLP results, whereas a role for excess LC risk attributable to undergoing numerous chest x‐ray screenings largely was unexamined. The authors of this report examined the consistency of the MLP data with a modified 2‐stage clonal expansion (TSCE) model of excess LC risk.METHODS:By using a simulation model calibrated to the initial MLP data, the authors examined the expected statistical variance of LC incidence and mortality between the screening and control arms. A Bayesian estimation framework using a modified version of the TSCE model to evaluate the role of excess LC risk attributable to chest x‐ray screening was derived and applied to the MLP data.RESULTS:Simulation experiments indicated that the overall difference in LC deaths and incidence between the study arm and the control arm was unlikely (P = .0424 and P = .0104, respectively) assuming no excess risk of LC. The authors estimated that the 10‐year excess LC risk for a man aged 60 years who smoked and who received 10 chest x‐ray screenings was 0.574% (P = .0021).CONCLUSIONS:The excess LC risk observed among screening arm participants was found to be statistically significant with respect to the TSCE model framework in part because of the incorporation of key risk correlates of age and screen frequency into the estimation framework. Cancer 2010. Published 2010 American Cancer Society