bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessing fibre‐rich feedstuffs in pig nutrition: comparison of methods and their potential implications
Authors: Sappok Maria , Pellikaan Wilbert F , Verstegen Martin WA , Sundrum Albert 
Published: September 2009

AbstractBACKGROUND: In organic farming, roughage has to be added to pigs' daily rations for animal welfare reasons. Since little is known about how roughage affects pigs, seven carbohydrate‐rich feedstuffs (corn silage, ryegrass, turnip leaf, turnip tuber, Jerusalem artichoke and two types of clover–ryegrass silage) were tested using two different in vitro methods—total tract digestibility and the gas production technique—to determine apparent digestibility by observing organic matter loss. The aim was to determine whether the results of different methods and treatments lead to similar results or rankings.RESULTS: The in vitro enzymatic incubation method showed 3–20% lower fermentabilities than the in vitro fermentation process. The pretreatment of substrates with enzymes before fermentation led to similar fermentabilities but different gas production kinetics compared to the fermentation of untreated substrates. Using two different inocula generated no significant differences. When the feedstuffs were ranked by their fermentability, the rank order was relatively similar for both methods.CONCLUSIONS: Different methods and pretreatments lead to different fermentabilities while a ranking of the results gives a similar order. Both methods seem to be appropriate tools for assessing feedstuffs. In order to determine which feedstuff is best utilised by the animal, further investigations of both digestibility and gas production kinetics are required. Copyright © 2009 Society of Chemical Industry
Staging laparoscopy enhances the detection of occult metastases in patients with pancreatic adenocarcinoma
Authors: Contreras Carlo M. , Stanelle Eric J. , Mansour John , Hinshaw J. Louis , Rikkers Layton F. , Rettammel Robert , Mahvi David M. , Cho Clifford S. , Weber Sharon M. 
Published: September 2009

AbstractBackgroundThe use of staging laparoscopy has been highly institutional dependent. We sought to assess the incidence of occult intra‐abdominal metastases identified at the time of staging laparoscopy for patients with either potentially resectable or locally advanced pancreatic adenocarcinoma (LAPC). We also compared the rate of occult metastases in patients who underwent staging laparoscopy versus laparotomy.MethodsPatients were confirmed to have potentially resectable or LAPC at a multidisciplinary hepatopancreaticobiliary conference. Patients with potentially resectable lesions were initially explored via staging laparoscopy or laparotomy, based on surgeon preference.ResultsOver a 4‐year period, 25 patients with potentially resectable tumors and 33 patients with LAPC were staged with laparoscopy, with an equivalent prevalence of occult metastases found at laparoscopy (28% potentially resectable vs. 33% LAPC, P = 0.8). Fifty‐two patients with potentially resectable lesions were explored initially via laparotomy. Occult peritoneal metastases were more likely to be detected in patients with potentially resectable tumors that were explored via laparoscopy than via laparotomy (32% vs. 10%, P = 0.018).ConclusionsStaging laparoscopy is more likely than open exploration to detect occult metastases. Current preoperative imaging inadequately identifies unresectable pancreatic adenocarcinoma; therefore, all patients with potentially resectable disease should undergo staging laparoscopy. J. Surg. Oncol. 2009;100:663–669. © 2009 Wiley‐Liss, Inc.
Magnetic resonance imaging of facial nerve schwannoma
Authors: Thompson Andrew L. , Aviv Richard I. , Chen Joseph M. , Nedzelski Julian M. , Yuen Heng‐Wai , Fox Allan J. , Bharatha Aditya , Bartlett Eric S. , Symons Sean P. 
Published: September 2009

AbstractObjectives/Hypothesis:This study characterizes the magnetic resonance (MR) appearances of facial nerve schwannoma (FNS). We hypothesize that the extent of FNS demonstrated on MR will be greater compared to prior computed tomography studies, that geniculate involvement will be most common, and that cerebellar pontine angle (CPA) and internal auditory canal (IAC) involvement will more frequently result in sensorineural hearing loss (SNHL).Study Design:Retrospective study.Methods:Clinical, pathologic, and enhanced MR imaging records of 30 patients with FNS were analyzed. Morphologic characteristics and extent of segmental facial nerve involvement were documented.Results:Median age at initial imaging was 51 years (range, 28–76 years). Pathologic confirmation was obtained in 14 patients (47%), and the diagnosis reached in the remainder by identification of a mass, thickening, and enhancement along the course of the facial nerve. All 30 lesions involved two or more contiguous segments of the facial nerve, with 28 (93%) involving three or more segments. The median segments involved per lesion was 4, mean of 3.83. Geniculate involvement was most common, in 29 patients (97%). CPA (P = .001) and IAC (P = .02) involvement was significantly related to SNHL. Seventeen patients (57%) presented with facial nerve dysfunction, manifesting in 12 patients as facial nerve weakness or paralysis, and/or in eight with involuntary movements of the facial musculature.Conclusions:This study highlights the morphologic heterogeneity and typical multisegment involvement of FNS. Enhanced MR is the imaging modality of choice for FNS. The neuroradiologist must accurately diagnose and characterize this lesion, and thus facilitate optimal preoperative planning and counseling. Laryngoscope, 2009
Energy output reduction and surface alteration of quartz and sapphire tips following Er:YAG laser contact irradiation for tooth enamel ablation
Authors: Eguro Toru , Aoki Akira , Maeda Toru , Takasaki Aristeo Atsushi , Hasegawa Mitsuru , Ogawa Masaaki , Suzuki Takanori , Yonemoto Kazuaki , Ishikawa Isao , Izumi Yuichi , Katsuumi Ichiroh 
Published: September 2009

AbstractBackgroundDespite the recent increase in application of Er:YAG laser for various dental treatments, limited information is available regarding the contact tips. This study examined the changes in energy output and surface condition of quartz and sapphire contact tips after Er:YAG laser contact irradiation for tooth enamel ablation.Materials and MethodsTen sets of unused quartz or sapphire contact tips were employed for contact irradiation to sound enamel of extracted teeth. The teeth were irradiated with Er:YAG laser at approximately 75 J/cm2/pulse and 20 Hz under water spray for 60 minutes. The energy output was measured before and every 5 minutes after irradiation, and the changes in morphology and chemical composition of the contact surface were analyzed.ResultsThe energy output significantly decreased with time in both tips. The energy output from the sapphire tips was generally higher on average than that of the quartz. The contact surfaces of all the used quartz tips were concave and irregular. Most of the sapphire tips also appeared rough with crater formation and fractures, except for a few tips in which a high energy output and the original smooth surface were maintained. Spots of melted tooth substances were seen attached to the surface of both tips.ConclusionIn contact enamel ablation, the sapphire tip appeared to be more resistant than the quartz tip. The quartz tips showed similar patterns of energy reduction and surface alteration, whereas the sapphire tips revealed a wider and more characteristic variation among tips. Lasers Surg. Med. 41:595–604, 2009. © 2009 Wiley‐Liss, Inc.
Manipulation of Electrostatic and Saccharide Linker Interactions in the Design of Efficient Glycopolypeptide‐Based Cholera Toxin Inhibitors
Authors: Maheshwari Ronak , Levenson Eric A. , Kiick Kristi L. 
Published: September 2009

AbstractMultivalent, glycopolymer inhibitors designed for the treatment of disease and pathogen infection have shown improvements in binding correlated with general changes in glycopolymer architecture and composition. We have previously demonstrated that control of glycopolypeptide backbone extension and ligand spacing significantly impacts the inhibition of the cholera toxin B subunit pentamer (CT B5) by these polymers. In the studies reported here, we elucidate the role of backbone charge and linker length in modulating the inhibition event. Peptides of the sequence AXPXG (where X is a positive, neutral or negative amino acid), equipped with the alkyne functionality of propargyl glycine, were designed and synthesized via solid‐phase peptide synthetic methods and glycosylated via Cu(I)‐catalyzed alkyne‐azide cycloaddition reactions. The capacity of the glycopeptides to inhibit the binding of the B5 subunit of cholera toxin was evaluated. These studies indicated that glycopeptides with a negatively charged backbone show improved inhibition of the binding event relative to the other glycopeptides. In addition, variations in the length of the linker between the peptide and the saccharide ligand also affected the inhibition of CT by the glycopeptides. Our findings suggest that, apart from appropriate saccharide spacing and polypeptide chain extension, saccharide linker conformation and the systematic placement of charges on the polypeptide backbone are also significant variables that can be tuned to improve the inhibitory potencies of glycopolypeptide‐based multivalent inhibitors.magnified image
Synthesis of Di‐block Copolymers Containing Regioregular Poly(3‐hexylthiophene) and Poly(tetrahydrofuran) by a Combination of Grignard Metathesis and Cationic Polymerizations
Authors: Alemseghed Mussie G. , Gowrisanker Srinivas , Servello John , Stefan Mihaela C. 
Published: September 2009

AbstractPoly(3‐hexylthiophene)‐block‐poly(tetrahydrofuran) was synthesized by cationic ring‐opening polymerization of tetrahydrofuran (THF) using a poly(3‐hexylthiophene) macroinitiator. Poly(3‐hexylthiophene) macroinitiator used for the ring‐opening polymerization of THF was synthesized by reacting the hydroxypropyl end‐group with trifluoromethanesulfonic anhydride in the presence of 2,6‐di‐tert‐butylpyridine. 1H NMR spectroscopy and SEC data confirmed the formation of the di‐block copolymers. Field‐effect mobility of poly(3‐hexylthiophene)‐block‐poly(tetrahydrofuran) was measured in a thin‐film transistor configuration and was found to be 0.009 cm2 · V−1 · s−1.magnified image
The Effects of Binding Ligand Variation on the Nickel Catalyzed Externally Initiated Polymerization of 2‐Bromo‐3‐hexyl‐5‐iodothiophene
Authors: Doubina Natalia , Stoddard Michelina , Bronstein Hugo A. , Jen Alex K.‐Y. , Luscombe Christine K. 
Published: September 2009

AbstractThe effects of binding ligand variation on the externally initiated Ni catalyzed polymerization of P3HT were investigated using a novel methodology allowing facile screening of ligands. P3HT was synthesized with >80% initiator incorporation for both mono‐ and bidentate phosphine ligands. Variation of the initiating aryl group demonstrated vastly superior results for o‐tolyl over p‐tolyl substituents.magnified image
Chain Transfer to Polymer and Branching in Controlled Radical Polymerizations of n‐Butyl Acrylate
Authors: Ahmad Nasir M. , Charleux Bernadette , Farcet Céline , Ferguson Christopher J. , Gaynor Scott G. , Hawkett Brian S. , Heatley Frank , Klumperman Bert , Konkolewicz Dominik , Lovell Peter A. , Matyjaszewski Krzysztof , Venkatesh Rajan 
Published: September 2009

AbstractChain transfer to polymer (CTP) in conventional free‐radical polymerizations (FRPs) and controlled radical polymerizations (ATRP, RAFT and NMP) of n‐butyl acrylate (BA) has been investigated using 13C NMR measurements of branching in the poly(n‐butyl acrylate) produced. The mol‐% branches are reduced significantly in the controlled radical polymerizations as compared to conventional FRPs. Several possible explanations for this observation are discussed critically and all except one refuted. The observations are explained in terms of differences in the concentration of highly reactive short‐chain radicals which can be expected to undergo both intra‐ and inter‐molecular CTP at much higher rates than long‐chain radicals. In conventional FRP, the distribution of radical concentrations is broad and there always is present a significant proportion of short‐chain radicals, whereas in controlled radical polymerizations, the distribution is narrow with only a small proportion of short‐chain radicals which diminishes as the living chains grow. Hence, irrespective of the type of control, controlled radical polymerizations give rise to lower levels of branching, when performed under otherwise similar conditions to conventional FRP. Similar observations are expected for other acrylates and monomers that undergo chain transfer to polymer during radical polymerization.magnified image
Self‐Assembled Micelles Based on PEG‐Polypeptide Hybrid Copolymers for Drug Delivery
Authors: Hua Shou‐Hu , Li Yong‐Yong , Liu Yun , Xiao Wang , Li Cao , Huang Fu‐Wei , Zhang Xian‐Zheng , Zhuo Ren‐Xi 
Published: September 2009

AbstractA series of amphiphilic poly(L‐leucine)‐block‐poly(ethylene glycol)‐block‐poly(L‐leucine) (PLL‐PEG‐PLL) hybrid triblock copolymers have been synthesized. All the blocks in this system have good biocompatibility and low toxicity. The PLL‐PEG‐PLL copolymers could self‐assemble into micelles with PLL blocks as the hydrophobic core and PEG blocks as the hydrophilic shell, which were characterized by FT‐IR, 1H NMR, and transmission electron microscopy analysis. The critical micellar concentration of the copolymer was 95.0 mg · L−1. The circular dichroism spectrum shows that the PLL segments adopt a unique α‐helical conformation, which is found to play an important role in controlling the drug release rate. The drug release could be effectively sustained by encapsulation in the micelles. The copolymers may have potential applications in drug delivery.magnified image
On the Phase Nature of Polymer Brush Collapse upon Solvent Deterioration
Authors: Amoskov Victor M. , Birshtein Tatiana M. 
Published: September 2009

AbstractThe phase nature of polymer brush collapse upon deterioration of the solvent was investigated. The analysis is based on the self‐consistent field theory and the Flory‐Huggins model. It was shown that the transition from good to poor solvent via the θ‐point is actually a phase transition of high order. This result contradicts the conventional view on this process as a non‐phase one. According to the Ehrenfest classification, this process appears to be a fifth‐order phase transition.magnified image
Hard versus Soft Materials as Supports for Metallocene and Post‐Metallocene Catalysts
Authors: Naundorf Corinna , Ferrari Daniela , Rojas Giovanni , Fink Gerhard , Klapper Markus , Müllen Klaus 
Published: September 2009

AbstractThe influence of organic supports on the polymerization behavior of post‐metallocene catalysts is studied and compared with similarly supported titanium and zirconium metallocenes. The effects of the immobilization, activation, and polymerization process were studied by video microscopy, laser confocal fluorescence microscopy, SEM, and TEM. A model for the polymerization process for a catalyst supported on latex particles was developed from the results obtained. Organic supports based on latex particles are easily adjustable for different catalysts due to the versatile functionalization of the surfaces and can be applied to different types of olefin polymerization catalysts. They can be considered as an alternative to SiO2 or MgCl2 supports.magnified image
Quantitative 19F imaging of nmol‐level F‐nucleotides/‐sides from 5‐FU with T2 mapping in mice at 9.4T
Authors: Doi Yoshihiro , Shimmura Toshiyuki , Kuribayashi Hideto , Tanaka Yoshitsugu , Kanazawa Yoko 
Published: September 2009

AbstractA unique acquisition method is proposed for quantitative, high‐sensitivity 19F MR spectroscopic imaging for the study of drug distribution aiming at nmol‐level metabolite information in mice. The use of fast spin echo (FSE) at 9.4T allowed us to obtain whole‐body images with minimal effect of magnetic susceptibility and to acquire several metabolite signals simultaneously by the method of interleaved multifrequency selection. Modified 2‐shot FSE was designed for simultaneous, high‐sensitivity 19F imaging and T2 mapping. A time course study including all the main metabolites at 10‐minute resolution was attained with an oral dose of 1–2 mmol 5‐fluorouracil (5‐FU) (130–260 mg)/kg in mice. With acquisition parameters optimized for in vivo T2 of 40 ms, images of F‐nucleotides/‐sides, effective anabolites of the anticancer drug 5‐FU, were obtained at the level of 200 nmol in the tumor for all the mice studied with a linear correlation (R = 0.96) between image intensity and the quantity determined in the excised tissue. The method exhibits potential capability of molecular imaging with a variety of 19F‐labeled compounds and drug evaluation. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
SENSE shimming (SSH): A fast approach for determining B0 field inhomogeneities using sensitivity coding
Authors: Splitthoff D.N. , Zaitsev M. 
Published: September 2009

AbstractThe pursuit of ever higher field strengths and faster data acquisitions has led to the construction of coil arrays with high numbers of elements. With the sensitivity encoding (SENSE) technique, it has been shown that the sensitivity of those elements can be used for spatial image encoding. Here, a proof‐of‐principle is presented of a method that can be considered an extreme case of the SENSE approach, completely abstaining from using encoding gradients. The resulting sensitivity encoded free‐induction decay (FID) data are then not used for imaging, but for determining B0 field inhomogeneity distribution. The method has therefore been termed “SENSE shimming” (SSH). In phantom experiments the method's ability to detect inhomogeneities of up to the second order is demonstrated. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Whole‐heart imaging using undersampled radial phase encoding (RPE) and iterative sensitivity encoding (SENSE) reconstruction
Authors: Boubertakh R. , Prieto C. , Batchelor P.G. , Uribe S. , Atkinson D. , Eggers H. , Sørensen T.S. , Hansen M.S. , Razavi R.S. , Schaeffter T. 
Published: September 2009

AbstractWhole‐heart isotropic nonangulated cardiac magnetic resonance (CMR) is becoming an important protocol in simplifying MRI, since it reduces the need of cumbersome planning of angulations. However the acquisition times of whole‐heart MRI are prohibitive due to the large fields of view (FOVs) and the high spatial resolution required for depicting small structures and vessels. To address this problem, we propose a three‐dimensional (3D) acquisition scheme that combines Cartesian sampling in the readout direction with an undersampled radial scheme in the phase‐encoding plane. Different undersampling patterns were investigated in combination with an iterative sensitivity encoding (SENSE) reconstruction and a 32‐channel cardiac coil. Noise amplification maps were calculated to compare the performance of the different patterns using iterative SENSE reconstruction. The radial phase‐encoding (RPE) scheme was implemented on a clinical MR scanner and tested on phantoms and healthy volunteers. The proposed method exhibits better image quality even for high acceleration factors (up to 12) in comparison to Cartesian acquisitions. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Improved SNR efficiency in gradient echo coronary MRA with high temporal resolution using parallel imaging
Authors: Yu Jing , Schär Michael , Vonken Evert‐Jan , Kelle Sebastian , Stuber Matthias 
Published: September 2009

AbstractContemporary coronary magnetic resonance angiography techniques suffer from signal‐to‐noise ratio (SNR) constraints. We propose a method to enhance SNR in gradient echo coronary magnetic resonance angiography by using sensitivity encoding (SENSE). While the use of sensitivity encoding to improve SNR seems counterintuitive, it can be exploited by reducing the number of radiofrequency excitations during the acquisition window while lowering the signal readout bandwidth, therefore improving the radiofrequency receive to radiofrequency transmit duty cycle. Under certain conditions, this leads to improved SNR. The use of sensitivity encoding for improved SNR in three‐dimensional coronary magnetic resonance angiography is investigated using numerical simulations and an in vitro and an in vivo study. A maximum 55% SNR enhancement for coronary magnetic resonance angiography was found both in vitro and in vivo, which is well consistent with the numerical simulations. This method is most suitable for spoiled gradient echo coronary magnetic resonance angiography in which a high temporal and spatial resolution is required. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Metabolite proton T2 mapping in the healthy rhesus macaque brain at 3 T
Authors: Liu Songtao , Gonen Oded , Fleysher Roman , Fleysher Lazar , Babb James S. , Soher Brian J. , Joo Chan‐Gyu , Ratai Eva‐Maria , González R. Gilberto 
Published: September 2009

AbstractThe structure and metabolism of the rhesus macaque brain, an advanced model for neurologic diseases and their treatment response, is often studied noninvasively with MRI and 1H‐MR spectroscopy. Due to the shorter transverse relaxation time (T2) at the higher magnetic fields these studies favor, the echo times used in 1H‐MR spectroscopy subject the metabolites to unknown T2 weighting, decreasing the accuracy of quantification which is key for inter‐ and intra‐animal comparisons. To establish the “baseline” (healthy animal) T2 values, we mapped them for the three main metabolites' T2s at 3 T in four healthy rhesus macaques and tested the hypotheses that their mean values are similar (i) among animals; and (ii) to analogs regions in the human brain. This was done with three‐dimensional multivoxel 1H‐MR spectroscopy at (0.6 × 0.6 × 0.5 cm)3 = 180 μL spatial resolution over a 4.2 × 3.0 × 2.0 = 25 cm3 (∼30%) of the macaque brain in a two‐point protocol that optimizes T2 precision per unit time. The estimated T2s in several gray and white matter regions are all within 10% of those reported in the human brain (mean ± standard error of the mean): N‐acetylaspartate = 316 ± 7, creatine = 177 ± 3, and choline = 264 ± 9 ms, with no statistically significant gray versus white matter differences. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Maximum linear‐phase spectral‐spatial radiofrequency pulses for fat‐suppressed proton resonance frequency–shift MR Thermometry
Authors: Grissom William A. , Kerr Adam B. , Holbrook Andrew B. , Pauly John M. , Butts‐Pauly Kim 
Published: September 2009

AbstractConventional spectral‐spatial pulses used for water‐selective excitation in proton resonance frequency–shift MR thermometry require increased sequence length compared to shorter wideband pulses. This is because spectral‐spatial pulses are longer than wideband pulses, and the echo time period starts midway through them. Therefore, for a fixed echo time, one must increase sequence length to accommodate conventional spectral‐spatial pulses in proton resonance frequency–shift thermometry. We introduce improved water‐selective spectral‐spatial pulses for which the echo time period starts near the beginning of excitation. Instead of requiring increased sequence length, these pulses extend into the long echo time periods common to PRF sequences. The new pulses therefore alleviate the traditional tradeoff between sequence length and fat suppression. We experimentally demonstrate an 11% improvement in frame rate in a proton resonance frequency imaging sequence compared to conventional spectral‐spatial excitation. We also introduce a novel spectral‐spatial pulse design technique that is a hybrid of previous model‐ and filter‐based techniques and that inherits advantages from both. We experimentally validate the pulses' performance in suppressing lipid signal and in reducing sequence length compared to conventional spectral‐spatial pulses. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.