bluuebunny/crossref_metadata_2025_split huggingface dataset:
Single‐walled carbon nanotubes alter Schwann cell behavior differentially within 2D and 3D environments
Authors: Behan Brenda L. , DeWitt Daniel G. , Bogdanowicz Danielle R. , Koppes Abigail N. , Bale Shyam S. , Thompson Deanna M. 
Published: October 2010

AbstractBoth spinal cord injury (SCI) and large‐gap peripheral nerve defects can be debilitating affecting a patient's long‐term quality of life and presently, there is no suitable treatment for functional regeneration of these injured tissues. A number of works have suggested the benefits of electrical stimulation to promote both glial migration and neuronal extension. In this work, an electrically conductive hydrogel containing single‐walled carbon nanotubes (SWCNT) for neural engineering applications is presented and the Schwann cell (SC) response to SWCNT is examined in both 2D and 3D microenvironments. Results from clonogenic and alamarBlue® assays in 2D indicate that SWCNT (10–50 μg mL−1) inhibit SC proliferation but do not affect cell viability. Following SWCNT exposure in 2D, changes in SC morphology can be observed with the nanomaterial attached to the cell membrane at concentrations as low as 10 μg mL−1. In contrast to the results gathered in 2D, SC embedded within the 3D hydrogel loaded with 10–50 μg mL−1 of SWCNT exhibited little or no measurable change in cell proliferation, viability, or morphology as assessed using a digestion assay, alamarBlue, and confocal microscopy. Collectively, this highlights that an electrically‐conductive SWCNT collagen I‐Matrigel™ biomaterial may be suitable for neural tissue engineering and is able to sustain populations of SC. Findings suggest that 2D nanoparticle toxicity assays may not be accurate predictors of the 3D response, further motivating the examination of these materials in a more physiologically relevant environment. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2010.
Early tissue response to citric acid–based micro‐ and nanocomposites
Authors: Chung Eun Ji , Qiu Hongjin , Kodali Pradeep , Yang Scott , Sprague Stuart M. , Hwong James , Koh Jason , Ameer Guillermo A. 
Published: October 2010

AbstractComposites based on calcium phosphates and biodegradable polymers are desirable for orthopedic applications because of their potential to mimic bone. Herein, we describe the fabrication, characterization, and in vivo response of novel citric acid–based microcomposites and nanocomposites. Poly(1,8‐octanediol‐co‐citrate) (POC) was mixed with increasing amounts of hydroxyapatite (HA) nanoparticles or microparticles (up to 60 wt %), and the morphology and mechanical properties of the resulting composites were assessed. To investigate tissue response, nanocomposites, microcomposites, POC, and poly(L‐lactide) were implanted in osteochondral defects in rabbits and harvested at 6 weeks for histological evaluation. Scanning electron microscopy confirmed increased surface roughness of microcomposites relative to nanocomposites. The mechanical properties of both types of composites increased with increasing amounts of HA (8–328 MPa), although nanocomposites with 60 wt % HA displayed the highest strength and stiffness. Based on tissue–implant interfacial assessments, all implants integrated well with the surrounding bone and cartilage with no evidence of inflammation. Both nanocomposites and microcomposites supported bone remodeling; however, nanocomposites induced more trabecular bone formation at the tissue–implant interface. The mechanical properties of citric acid–based composites are within the range of human trabecular bone (1–1524 MPa, 211 ± 78 MPa mean modulus), and tissue response was dependent on the size and content of HA, providing new perspectives of design and fabrication criteria for orthopedic devices such as interference screws and fixation pins. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.
A theoretical survey on the structures, energetics, and isomerization pathways of the B5O radical
Authors: Shao Chang‐Bin , Jin Lin , Ding Yi‐Hong 
Published: October 2010

AbstractBoron‐centered radicals have received growing interest. Recently, two groups reported density functional theory investigations (GGA‐PW91 and B3LYP) on a hexa‐atomic boron‐oxide radical, B5O, which has led to great discrepancies on the type of low‐lying structures. In this article, we not only explore the energetics of doublet and quartet B5O isomers at high electron‐correlated levels (CCSD(T)/6‐311+G(2df), CCSD(T)/aug‐cc‐pVTZ, and G3B3) but also investigate the isomerization and fragmentation stability of the low‐lying B5O isomers. All the high‐level studies consistently show that the B5O radical possesses a belt‐like ground structure 201 in doublet electronic state followed by isomer 202 with an exocyclic BO moiety at around 3.0 kcal/mol. Kinetically, 201 and 202 are separated by a considerable barrier of about 20 kcal/mol. Thus, the two isomeric forms of B5O radical should be very promising for isolation in laboratory. However, the other four isomers reported recently are all kinetically unstable toward conversion to 201 and 202. The high thermodynamic and kinetic stability of 201 and 202 might make them as important building cores in the growth of boron‐oxide clusters. This results would also help deeply understand the oxidation and doping mechanism of pure boron clusters. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2011
A novel predictive model for formation enthalpies of Si and Ge hydrides with propane‐ and butane‐like structures
Authors: Weng C. , Kouvetakis J. , Chizmeshya A. V. G. 
Published: October 2010

AbstractButane‐ and propane‐like silicon–germanium hydrides and chlorinated derivatives represent a new class of precursors for the fabrication of novel metastable materials at low‐temperature regimes compatible with selective growth and commensurate with the emerging demand for the reduced thermal budgets of complementary metal oxide semiconductor integration. However, predictive simulation studies of the growth process and reaction mechanisms of these new compounds, needed to accelerate their deployment and fine‐tune the unprecedented low‐temperature and low‐pressure synthesis protocols, require experimental thermodynamic data, which are currently unavailable. Furthermore, traditional quantum chemistry approaches lack the accuracy needed to treat large molecules containing third‐row elements such as Ge. Accordingly, here we develop a method to accurately predict the formation enthalpy of these compounds using atom‐wise corrections for Si, Ge, Cl, and H. For a test set of 15 well‐known hydrides of Si and Ge and their chlorides, such as Si3H8, Ge2H6, SiGeH6, SiHCl3, and GeCl4, our approach reduces the deviations between the experimental and predicted formation enthalpies obtained from complete basis set (CBS‐QB3), G2, and B3LPY thermochemistry to levels of 1–3 kcal/mol, or a factor of ∼5 over the corresponding uncorrected values. We show that our approach yields results comparable or better than those obtained using homodesmic reactions while circumventing the need for thermochemical data of the associated reaction species. Optimized atom‐wise corrections are then used to generate accurate enthalpies of formation for 39 pure Si‐Ge hydrides and a selected group of 20 chlorinated analogs, of which some have recently been synthesized for the first time. Our corrected enthalpies perfectly reproduce the experimental stability trends of heavy butane‐like compounds containing Ge. This is in contrast to the direct application of the CBS‐QB3 method, which yields erratic predictions. Our approach also provides quantitative bond‐additivity rules for the chlorination of these heavier species. Finally, we discuss structure and bonding trends across the entire sequence of butane‐, propane‐, and ethane‐like molecules with a special focus on the isomeric variations. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2011
Assessing the performance of the molecular mechanics/Poisson Boltzmann surface area and molecular mechanics/generalized Born surface area methods. II. The accuracy of ranking poses generated from docking
Authors: Hou Tingjun , Wang Junmei , Li Youyong , Wang Wei 
Published: October 2010

AbstractIn molecular docking, it is challenging to develop a scoring function that is accurate to conduct high‐throughput screenings. Most scoring functions implemented in popular docking software packages were developed with many approximations for computational efficiency, which sacrifices the accuracy of prediction. With advanced technology and powerful computational hardware nowadays, it is feasible to use rigorous scoring functions, such as molecular mechanics/Poisson Boltzmann surface area (MM/PBSA) and molecular mechanics/generalized Born surface area (MM/GBSA) in molecular docking studies. Here, we systematically investigated the performance of MM/PBSA and MM/GBSA to identify the correct binding conformations and predict the binding free energies for 98 protein–ligand complexes. Comparison studies showed that MM/GBSA (69.4%) outperformed MM/PBSA (45.5%) and many popular scoring functions to identify the correct binding conformations. Moreover, we found that molecular dynamics simulations are necessary for some systems to identify the correct binding conformations. Based on our results, we proposed the guideline for MM/GBSA to predict the binding conformations. We then tested the performance of MM/GBSA and MM/PBSA to reproduce the binding free energies of the 98 protein–ligand complexes. The best prediction of MM/GBSA model with internal dielectric constant 2.0, produced a Spearman's correlation coefficient of 0.66, which is better than MM/PBSA (0.49) and almost all scoring functions used in molecular docking. In summary, MM/GBSA performs well for both binding pose predictions and binding free‐energy estimations and is efficient to re‐score the top‐hit poses produced by other less‐accurate scoring functions. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2011
Structure and dynamics of methanol in water: A quantum mechanical charge field molecular dynamics study
Authors: Moin Syed Tarique , Hofer Thomas S. , Randolf Bernhard R. , Rode Bernd M. 
Published: October 2010

AbstractAn ab initio quantum mechanical charge field molecular dynamics simulation was carried out for one methanol molecule in water to analyze the structure and dynamics of hydrophobic and hydrophilic groups. It is found that water molecules around the methyl group form a cage‐like structure whereas the hydroxyl group acts as both hydrogen bond donor and acceptor, thus forming several hydrogen bonds with water molecules. The dynamic analyses correlate well with the structural data, evaluated by means of radial distribution functions, angular distribution functions, and coordination number distributions. The overall ligand mean residence time, τ identifies the methanol molecule as structure maker. The relative dynamics data of hydrogen bonds between hydroxyl of methanol and water molecules prove the existence of both strong and weak hydrogen bonds. The results obtained from the simulation are in excellent agreement with the experimental results for dilute solution of CH3OH in water. The overall hydration shell of methanol consists in average of 18 water molecules out of which three are hydrogen bonded. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2011
Rapid evaluation of the binding energies in hydrogen‐bonded amide–thymine and amide–uracil dimers in gas phase
Authors: Li Yang , Jiang Xiao‐Nan , Wang Chang‐Sheng 
Published: October 2010

AbstractThe binding energies and the equilibrium hydrogen bond distances as well as the potential energy curves of 48 hydrogen‐bonded amide–thymine and amide–uracil dimers are evaluated from the analytic potential energy function established in our lab recently. The calculation results show that the potential energy curves obtained from the analytic potential energy function are in good agreement with those obtained from MP2/6‐311+G** calculations by including the BSSE correction. For all the 48 dimers, the analytic potential energy function yields the binding energies of the MP2/6‐311+G** with BSSE correction within the error limits of 0.50 kcal/mol for 46 dimers, only two differences are larger than 0.50 kcal/mol and the largest one is only 0.60 kcal/mol. The analytic potential energy function produces the equilibrium hydrogen bond distances of the MP2/6‐311+G** with BSSE correction within the error limits of 0.050 Å for all the 48 dimers. The analytic potential energy function is further applied to four more complicated hydrogen‐bonded amide–base systems involving amino acid side chain and β‐sheet. The values of the binding energies and equilibrium hydrogen bond distances obtained from the analytic potential energy function are also in good agreement with those obtained from MP2 calculations with the BSSE correction. These results demonstrate that the analytic potential energy function can be used to evaluate the binding energies in hydrogen‐bonded amide–base dimers quickly and accurately. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2011
Role of intraoperative microvascular Doppler in the microsurgical management of intracranial aneurysms
Authors: Cui Hua , Wang Yong , Yin Yuhua , Wan Jieqing , Fei Zhimin , Gao Weizhen , Jiang Jiyao 
Published: October 2010

AbstractBackgroundThe outcome of surgical treatment of intracranial aneurysms may be influenced by incomplete exclusion of the aneurysm or stenosis of the parent vessels. The goal of this study was to evaluate the usefulness and reliability of intraoperative microvascular Doppler (IMD) in guiding optimal clip placement in aneurysm surgery.MethodsWe conducted a retrospective analysis of 79 patients, with a total of 85 intracranial aneurysms, operated between January 2004 and April 2009, who were evaluated with IMD using a 20‐MHz probe before and after clip application. IMD was used to examine the aneurysmal sac and adjacent vessels.ResultsThe findings of IMD helped in adjusting the clip placement. In 9 (10.6%) of the 85 aneurysms, IMD revealed a persistent blood flow through the aneurysmal sac after clip application and the clip was repositioned. IMD showed relevant stenosis of adjacent vessels induced by the clip positioning in 10 of 79 (12.7%) cases. In six cases (7.6%), a blood flow reduction in the artery feeding the aneurysm was evident after clipping; in the other four cases (5.1%), the clip produced a severe blood flow reduction in other adjacent vessels. In addition, in two of these cases, an initial stenosis induced by clip positioning that had escaped detection by visual inspection through the operating microscope was identified by IMD. There were no complications related to the use of IMD.ConclusionsIMD is a safe, feasible, and very reliable technique and should be used routinely in intracranial aneurysm surgery. © 2010 Wiley Periodicals, Inc. J Clin Ultrasound, 2011
Histochemical analysis of the root tuber of Polygonum multiflorum Thunb. (Fam. Polygonaceae)
Authors: Liang Zhi‐Tao , Shi Yi‐Xiao , Chen Hu‐Biao , Zhao Zhong‐Zhen 
Published: October 2010

AbstractAuthentication is the first priority in quality evaluation of Chinese herbal medicines (CHMs). The most commonly used authentication methods are morphological identification and microscopic identification. Unfortunately, these two methods cannot provide the chemical information needed to assess the quality of CHMs. In this study, a combination of fluorescence microscopy and high performance liquid chromatography–mass spectrometry (HPLC–MS) was used to analyze the chemical profiles of the tissues of the raw root tubers of Polygonum multiflorum Thunb. The results showed that the cork cells, cortex, and vessels in transverse sections of the raw root tuber of P. multiflorum fluoresced differently. Further analysis by HPLC–MS revealed that anthraquinones are mainly distributed in the cortex, and 2,3,5,4′‐tetrahydroxystilbene‐2‐O‐β‐D‐glucopyranoside could be found in all tissues of the raw root tubers of P. multiflorum with its relative content as cork > cortex > xylem of allotype vascular bundles > xylem of central vascular bundles. Moreover, the fluorescence characteristics of the tissues from the steamed root tuber of P. multiflorum were compared and showed different fluorescence from those of raw material. From these results, it can be deduced that the root tuber of P. multiflorum with a broader cortex and fewer vascular bundles visible in a transverse section should be of better quality. The different fluorescence characteristics can be used to differentiate raw root tubers of P. multiflorum from those that have been steamed. Microsc. Res. Tech., 2010. © 2010 Wiley‐Liss, Inc.
An overview of the legislation and light microscopy for detection of processed animal proteins in feeds
Authors: Liu Xian , Han Lujia , Veys Pascal , Baeten Vincent , Jiang Xunpeng , Dardenne Pierre 
Published: October 2010

AbstractFrom the first cases of bovine spongiform encephalopathy (BSE) among cattle in the United Kingdom in 1986, the route of infection of BSE is generally believed by means of feeds containing low level of processed animal proteins (PAPs). Therefore, many feed bans and alternative and complementary techniques were resulted for the BSE safeguards in the world. Now the feed bans are expected to develop into a “species to species” ban, which requires the corresponding species‐specific identification methods. Currently, banned PAPs can be detected by various methods as light microscopy, polymerase chain reaction, enzyme‐linked immunosorbent assay, near infrared spectroscopy, and near infrared microscopy. Light microscopy as described in the recent Commission Regulation EC/152/2009 is the only official method for the detection and characterization of PAPs in feed in the European Union. It is able to detect the presence of constituents of animal origin in feed at the level of 1 g/kg with hardly any false negative. Nevertheless, light microscopy has the limitation of lack of species specificity. This article presents a review of legislations on the use of PAPs in feedstuff, the detection details of animal proteins by light microscopy, and also presents and discusses the analysis procedure and expected development of the technique. Microsc. Res. Tech., 2011. © 2010 Wiley‐Liss, Inc.
Sweep MRI with algebraic reconstruction
Authors: Weiger Markus , Hennel Franciszek , Pruessmann Klaas P. 
Published: October 2010

AbstractIn the recently proposed technique Sweep Imaging with Fourier Transform (SWIFT), frequency‐modulated radiofrequency pulses are used in concert with simultaneous acquisition to facilitate MRI of samples with very short transverse relaxation time. In the present work, sweep MRI is reviewed from a reconstruction perspective and several extensions and modifications of the current methodology are proposed. An algorithm for algebraic image reconstruction is derived from a comprehensive description of signal formation, including interleaved radiofrequency transmission and acquisition of arbitrary timing as well as the relevant filtering and decimation steps along the receiver chain. The new reconstruction approach readily permits several measures of optimising the signal sampling strategy as demonstrated in simulations and imaging experiments. Employing a variety of radiofrequency pulse envelopes, water and rubber phantoms as well as bone samples with transverse relaxation time in the order of 500 μsec were imaged at signal bandwidths of up to 96 kHz. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Finite RF pulse correction on DESPOT2
Authors: Crooijmans H. J. A. , Scheffler K. , Bieri O. 
Published: October 2010

AbstractMagnetization transfer and finite radiofrequency (RF) pulses affect the steady state of balanced steady state free precession. As quantification of transverse relaxation (T2) with driven equilibrium single pulse observation of T2 is based on two balanced steady state free precession acquisitions, both effects can influence the outcome of this method: a short RF pulse per repetition time (TRF/TR ≪ 1) leads to considerable magnetization transfer effects, whereas prolonged RF pulses (TRF/TR > 0.2) minimize magnetization transfer effects, but lead to increased finite pulse effects. A correction for finite pulse effects is thus implemented in the driven equilibrium single pulse observation of T2 theory to compensate for reduced transverse relaxation effects during excitation. It is shown that the correction successfully removes the driven equilibrium single pulse observation of T2 dependency on the RF pulse duration. A reduction of the variation in obtained T2 from over 50% to less than 10% is achieved. We hereby provide a means of acquiring magnetization transfer‐free balanced steady state free precession images to yield accurate T2 values using elongated RF pulses. Magn Reson Med, 2011. © 2010 Wiley‐Liss, Inc.
Psychological Treatments for Obesity in Youth and Adults
Authors: Lo Presti Rebecca , Lai Justine , Hildebrandt Tom , Loeb Katharine L. 
Published: October 2010

AbstractObesity has become a leading global health concern affecting both physical and mental quality of life. This article reviews the psychological interventions currently utilized in confronting the obesity epidemic. It examines obesity in both the pediatric and adult populations, specifically considering empirical evidence of weight loss interventions through randomized control trials. Behavioral weight loss intervention and family‐based interventions emerged as 2 of the more frequently utilized and data‐supported approaches. Empirically supported psychological treatments for subgroups of the obese population, such as individuals with binge eating disorder, are considered here as well. Limitations of the current interventions are discussed, including issues with generalizability across demographic variables such as age and severity of overweight status. Despite these limitations, overall, psychological interventions play an important role in achieving and maintaining weight loss. Mt Sinai J Med 77:472–487, 2010. © 2010 Mount Sinai School of Medicine