bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of the solvent representation on vibrational entropy calculations: Generalized born versus distance‐dependent dielectric model
Authors: Kopitz Hannes , Cashman Daniel A. , Pfeiffer‐Marek Stefania , Gohlke Holger 
Published: February 2012

AbstractThe harmonic model is the most popular approximation for estimating the “configurational” entropy of a solute in molecular mechanics/Poisson‐Boltzmann solvent accessible surface area (MM/PBSA)‐type binding free energy calculations. Here, we investigate the influence of the solvent representation in the harmonic model by comparing estimates of changes in the vibrational entropies for 30 trypsin/ligand complexes on ligand binding. Second derivatives of Amber generalized Born (GB) solvation models are available in the nucleic acid builder code. They allow one to use these models for the calculation of vibrational entropies instead of using a simpler solvation model based on a distance‐dependent dielectric (DDD) constant. Estimates of changes in the vibrational entropies obtained with a DDD model are systematically and significantly larger, by on average, 6 kcal mol−1 (at T = 300 K), than estimates obtained with a GB model and so are more favorable for complex formation. The difference becomes larger the more the vibrational entropy contribution disfavors complex formation, that is, the larger the ligand is (for the complexes considered here). A structural decomposition of the estimates into per‐residue contributions reveals polar interactions between the ligand and the surrounding protein, in particular involving charged nitrogens, as a main source of the differences. Snapshots minimized with the DDD model showed a structural deviation from snapshots minimized in explicit water that is larger by, on average, 0.5 Å RMSD compared to snapshots that were minimized with GBHCT. As experimental vibrational entropies of biomacromolecules are elusive, there is no direct way to establish a solvent model's superiority. Thus, we can only recommend using the GB harmonic model for vibrational entropy calculations based on the reasoning that smaller structural deviations should point to the implicit solvent model that closer approximates the energy landscape of the solute in explicit solvent. © 2012 Wiley Periodicals, Inc.
Optimization of oxygen transfer through venturi‐based systems applied to the biological sweetening of biogas
Authors: Rodriguez Ginesta , Dorado Antonio David , Bonsfills Anna , Sanahuja Ricard , Gabriel David , Gamisans Xavier 
Published: February 2012

AbstractBACKGROUND: Dissolved oxygen is a key parameter in the biological removal of gaseous H2S since sulfide‐oxidizing bacteria convert H2S into elemental sulfur instead of sulfate under limiting dissolved oxygen concentrations. Elemental sulfur is insoluble in water and accumulates in the packing material in biotrickling filters, increasing the pressure drop and operating costs. A set of mass transfer tests was performed in a versatile pilot plant to supply the necessary oxygen for the biological oxidation of H2S. The plant can be operated with three different commercial gas–liquid contactor devices: a venturi ejector, a jet‐venturi and a diffuser. The effects of different geometric and operating parameters have been tested for each device (including pressure rise and sulfate content to mimic real wastewater treatment plant conditions).RESULTS: Results showed that the bioreactor pressure has a strong influence on the mass transfer characteristics of the three oxygenation devices. In addition, the ionic strength of the solution has a low influence on the mass transfer process.The SOTE values obtained for the diffuser, jet‐venturi and venturi ejector were 8.7%, 7.2% and 6.0%, respectively (pure water experiments), while SAE values were in the range 6.3–5.5 × 10−2, 4.1–4.8 × 10−1 and 3.1–3.7 × 10−1 kg O2 kW−1 h−1, respectively.CONCLUSIONS: The jet‐venturi offers the best oxygen transfer with lower power consumption compared with the diffuser and venturi ejector. The practical implementation of the most efficient aeration technology is possible from both technical and economical perspectives. Copyright © 2012 Society of Chemical Industry
Influences of the insertion method in glass ionomer cement porosity
Authors: Da Mata Margareth , Santos‐Pinto Lourdes , Cilense Zuanon Angela Cristina 
Published: February 2012

AbstractThe aim of this study was to evaluate the presence of porosities inside the glass ionomer cement (GIC) after different techniques of material insertion. MATERIAL AND METHOD: Specimens were prepared with high‐viscosity GIC Ketac Molar Easymix and divided into three groups according to the insertion method: spatula (PI), Centrix injector (CI), and low‐cost syringe (LCS). The specimens were fractured and observed with scanning electronic microscopy to quantitatively evaluate porosity inside the material using Image J Software. RESULTS: Statistical analysis, ANOVA application, and Tukey test to significance level of 5%, revealed that there was no statistical difference between the groups. CONCLUSION: Although the use of LCS has not decreased the porosity of the material, this insertion method is easy, accessible, and low cost, which makes it a viable alternative of use in the ART technique and in others bucal health programs. Microsc. Res. Tech., 2012. © 2012 Wiley Periodicals, Inc.
Effect of disinfectant solutions on gutta‐percha and resilon cones
Authors: Prado Maíra , Gusman Heloisa , Gomes Brenda P.F.A. , Simão Renata A. 
Published: February 2012

AbstractThe aim of this study was to evaluate the effects of the 5.25% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), and MTAD solutions on the surface of gutta‐percha and Resilon cones by using atomic force microscopy (AFM). Accessory cones were washed and dried. The cones were randomly divided into six groups: gutta‐percha immersed in NaOCl, CHX, and MTAD, and Resilon immersed in NaOCl, CHX, and MTAD. AFM images of the same area were made in different periods of time. JPK™ Image Processing Software was used to evaluate the images. The parameters used to evaluate the changes were RMS and line profiles. No statistically significant change was observed in the RMS values. The line profiles detected changes only for gutta‐percha surfaces after immersion in NaOCl and MTAD solutions. In conclusion, 5.25% NaOCl and MTAD are associated with local changes in surface roughness of gutta‐percha cones. No change was observed when 2% CHX was used. The use of all tested solutions did not produce any changes on Resilon surface. Microsc. Res. Tech. 75:791–795, 2012. © 2012 Wiley Periodicals, Inc.
Control‐matched computational evaluation of tendo‐femoral contact in patients with posterior‐stabilized total knee arthroplasty
Authors: Hoops Heather E. , Johnson Derek R. , Kim Raymond H. , Dennis Douglas A. , Baldwin Mark A. , Fitzpatrick Clare K. , Laz Peter J. , Rullkoetter Paul J. 
Published: February 2012

AbstractPainful patellar crepitus is a potential complication in up to 14% of patients following posterior‐stabilized (PS) total knee arthroplasty (TKA). A recent clinical study identified influential patient and surgical variables by comparing a group of crepitus patients with controls matched for age, sex, and body mass index. The purpose of our study was to evaluate effects of variables identified as significant in the clinical study, including patellar ligament length, femoral component flexion, patellar button size, and position of the joint line, on contact between the quadriceps tendon and the PS femoral component. A previously verified finite element model was utilized to estimate tendo‐femoral contact during deep flexion activity. Using discrete perturbations, the computational model confirmed the clinical findings in that an increased patellar ligament length, flexed femoral component, lowered joint line, and larger patellar component all reduced potentially deleterious contact near the intercondylar notch. With the selected level of anatomic and component alignment perturbations, the most influential factor affecting tendo‐femoral contact was patellar ligament length. Three crepitus patients with matched controls were subsequently modeled, and contact with the anterior border of the notch was present in each crepitus patient, but none of the controls. Alternative surgical alignments for these patients were evaluated to improve the potential long‐term outcomes. By characterizing conditions that may lead to painful crepitus, the modeling approach supports clinicians by identifying pre‐surgical indicators and important alignment parameters to control intraoperatively. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1355–1361, 2012
Comparison of a colorimetric and a high‐performance liquid chromatography method for the determination of fructan in pasture grasses for horses
Authors: Longland Annette C , Dhanoa Mewa S , Harris Patricia A 
Published: February 2012

AbstractBACKGROUND: Pasture (fresh or conserved as hay/haylage) forms the basis of most equid diets and contains varying amounts (0 to ≥ 200 g kg−1 dry matter (DM) or more) of fructans. Over‐consumption of fructan is associated with the onset of laminitis in equids, an agonizing condition that may necessitate euthanasia. To enable appropriate dietary management of animals susceptible to laminitis, it is essential that fructans can be properly quantified in fresh and conserved pasture. For research purposes, fructans are frequently quantified by high‐performance liquid chromatography (HPLC), but these methods are costly for routine screening. However, an inexpensive colorimetric method for measuring fructans in human foods is commercially available. The aim here was to determine the suitability of the commercially available colorimetric method for determining the fructan content of pasture grasses for horses.RESULTS: Pasture grasses (Phleum pretense, Festuca rubra, Dactylis glomerata, Lolium perenne) managed for grazing (sampled from April to November) and a further set managed for conservation (sampled in July) were analysed for fructan content by HPLC and the colorimetric technique. HPLC values ranged from 83 to 299 g fructan kg−1 DM (mean 154); corresponding colorimetric values were 5‐238 g fructan kg−1 DM (mean 82). Discrepancies in values between the two methods varied with time of sampling and plant species. Comparison of selected samples before and after incubation with the fructan hydrolases used in the colorimetric method revealed incomplete fructan hydrolysis from the pasture grasses, resulting in underestimates of their fructan content.CONCLUSION: The colorimetric technique was not a reliable substitute for HPLC to quantify the fructan content of pasture grasses. Copyright © 2012 Society of Chemical Industry
Direct cauterization of the nasal septal artery for epistaxis
Authors: Cooper Sarah E. , Ramakrishnan Vijay R. 
Published: February 2012

AbstractEmergency management of epistaxis may include the use of local pressure and vasoconstrictors, chemical or electric cautery, hemostatic agents, nasal packing, embolization, and surgical arterial ligation. There is no definitive protocol for the management of epistaxis, although various protocols have been proposed in the literature. As approaches to surgical ligation of the arterial supply of the nasal cavity have evolved from external carotid ligation to minimally invasive approaches, surgical management of epistaxis has become more effective than embolization and may be less risky. In the surgical management of epistaxis, arterial ligation immediately proximal to the bleeding site is preferred. We propose a simple variation of the endoscopic sphenopalatine artery ligation that may be used to manage epistaxis arising from the nasal septum and floor. Laryngoscope, 2012
Computational fluid dynamics for investigation of saliva pressure in parotid obstruction
Authors: Xu Yue , Zhou Wenyan , Zhu Ping , Han Yi , Zheng Youhua , Li Jibin , Zhang Zhiguang 
Published: February 2012

AbstractObjectives/Hyothesis:Parotid obstruction is one of the most common problems affecting the parotid gland. We aimed to investigate the blockage ratio (BR) and the intraductal pressure change of Stensen's duct using computational fluid dynamics.Study Design:Retrospective review of 16 patients who had undergone interventional sialendoscopy for parotid obstruction from 2009 to 2011.Methods:The three‐dimensional configurations of Stensen's duct were reconstructed from computed tomography (CT) sialographic images. Finite volume modeling in fluid dynamics of parotid obstruction was used to analyze the pressure distribution under conditions of rest and stimulation.Results:Intraductal pressure increased with increasing distance from the orifice. The upstream pressure was higher than that of downstream pressure in the same BR (P < .05). The upstream pressure increased as the BR increased. Statistically, the pressure turning point was indicated when BR = 60%. Only when the BR was much greater than 90% did the pressure reach 811.64 Pa, at which point patients could feel the painful swelling under the rest condition. Under the stimulated condition, the upstream pressure increased from 1.3‐ to 2.9‐fold of that of the no blocking state when the BR increased from 80% to 90%, which may aggravate the obstructive symptoms. There was no significant difference observed for downstream pressure under the same condition (P > .05).Conclusions:CT sialography was effectively used for analysis of the intraductal pressure distribution in patients with parotid obstruction. Analysis of salivary fluid dynamics in Stensen's duct may provide a further pathophysiological mechanism for obstructive diseases.
Cochlear implant performance in geriatric patients
Authors: Lenarz Minoo , Sönmez Hasibe , Joseph Gert , Büchner Andreas , Lenarz Thomas 
Published: February 2012

AbstractObjectives/Hypothesis:To evaluate the hearing performance with cochlear implants (CIs) in patients who were 70 years or older at the time of implantation (geriatric patients) and compare it with the performance in younger adults.Study Design:Individual, retrospective, cohort study.Methods:A cohort of 1,005 postlingually deafened adults was selected for this study. According to their age at the time of cochlear implantation, patients were divided into four age groups: group 1, 18 to 39 years; group 2, 40 to 59 years; group 3, 60 to 69 years; and group 4, 70 years and older). The test battery was composed of four standard German speech tests: Freiburger Monosyllabic Test, Speech Tracking Test, and Hochmair‐Schulz‐Moser (HSM) Sentence Test in quiet and in 10 dB noise.Results:Geriatric patients showed a similar learning curve as the younger adults in the first 2 years after implantation. The direct comparison of speech perception in the Freiburger Monosyllabic Test, Speech Tracking Test, and HSM Test in quiet revealed no differences between the average performance of the geriatric patients and younger adults. However, in the HSM Test in noise, the performance of the geriatric group was significantly lower than the younger adults.Conclusions:Geriatric CI patients have a similar learning curve to younger adults, and in speech tests in quiet they show a comparable performance. However, their performance is significantly lower in noisy surroundings. This may be due to the central presbycusis in patients older than 70 years and should be taken into account in postoperative fitting of these patients. Further prospective studies are required to evaluate the role of special rehabilitation methods and cognitive training to improve the speech perception in noise in geriatric CI patients.
Watch peripheral arterial tonometry in the diagnosis of obstructive sleep apnea: Influence of aging
Authors: Onder Nilgun Surmen , Akpinar Meltem Esen , Yigit Ozgur , Gor Ayse Pelin 
Published: February 2012

AbstractObjectives/Hypothesis:To investigate the consequences of aging and associated peripheral vascular tone impairment on peripheral arterial tonometry (Watch PAT)‐based sleep and respiratory disturbance analysis in obstructive sleep apnea (OSA) diagnosis.Study Design:Prospective, nonrandomized, clinical trial.Methods:A total of 56 subjects with age ranges of 20 to 35 years (group I, n = 27) and 50 to 65 years (group II, n = 29) referred to the sleep laboratory for overnight polysomnography (PSG) with suspected OSA were enrolled. All patients underwent simultaneous overnight PSG and Watch PAT monitoring. The data derived from PSG and Watch PAT records, including apnea‐hypopnea index (AHI), rapid eye movement (REM) AHI, non‐rapid eye movement (NREM) AHI, oxygen desaturation index (ODI), mean O2 saturation (mean O2 sat), minimum O2 saturation (min O2 sat), sleep duration, and the percentages of NREM sleep stages 1‐2 and 3 and of REM sleep were used for comparisons. The calculated ΔPSG‐Watch PAT of the two groups were compared statistically. The correlations between the PSG‐Watch PAT measurements in each group were assessed.Results:The comparison of AHI, REM AHI, NREM AHI, ODI, mean O2 sat, min O2 sat, NREM sleep stage 1‐2, and REM sleep ΔPSG‐Watch PAT between the two groups did not reveal statistical significance. The difference between the two groups in terms of ΔPSG‐Watch PAT of sleep duration and sleep stage 3 was statistically significant.Conclusions:In addition to the good agreement confirmed between PSG and Watch PAT data in each group, aging did not negatively impact Watch PAT recorded data in terms of included parameters, except the difference in ΔPSG‐Watch PAT of sleep stage 3, which may be attributable to aging and impaired vascular tone.
Synthesis of atrial natriuretic peptide in the rabbit inner ear
Authors: Yoon Yong Joo , Lee Eun Jung , Kim Suhn Hee 
Published: February 2012

AbstractObjectives/Hypothesis:Atrial natriuretic peptide (ANP) exhibits natriuretic, diuretic, and vasorelaxant activity, maintaining fluid and electrolyte homeostasis. Although ANP is mainly synthesized and secreted in/from atrium, ANP has been found in various tissues including the rat inner ear. The aim of this study was to identify the synthesis of ANP in lateral cochlear wall tissues and the presence of ANP in perilymph using rabbits.Study Design:In vivo study using a rabbit model.Methods:Expression of ANP in the rabbit inner ear tissue and the presence of perilymph were examined by radioimmunoassay and polymerase chain reaction using an ANP polyclonal antibody and rat ANP primers, respectively. Characteristics of ANP and pro‐ANP present in the inner ear were also evaluated by high‐performance liquid chromatography (HPLC), comparing to rat cardiac ANP and pro‐ANP.Results:Immunoreactive ANP (ir‐ANP) was found in the perilymph and lateral cochlear wall tissue of rabbits. The levels of ir‐ANP in the perilymph were 5 to 16 ng/mL. Elusion profiles of HPLC showed two main peaks that were exactly matched with rat cardiac ANP and pro‐ANP. Expression of ANP mRNA was also detected.Conclusions:Our findings suggest that ANP and its precursor protein are synthesized in the ear tissues and secreted to perilymph. This hormone may play a role in control of water and/or ion homeostasis of the fluids in the ear that are responsible for normal hearing.
Traces of vector‐valued Sobolev spaces
Authors: Scharf Benjamin , Schmeißer Hans‐Jürgen , Sickel Winfried 
Published: February 2012

AbstractDedicated to Professor V. I. Burenkov on the occasion of his 70th birthday We characterize the traces of vector‐valued Besov and Lizorkin‐Triebel spaces. Therefrom we derive the corresponding assertions for the vector‐valued Sobolev spaces\documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$W^m_{p}({\mathbf R}^n,E)\,$\end{document}. Here we do not assume the UMD property for the Banach spaceE.
Importance of the latex‐clearing protein (Lcp) for poly(cis‐1,4‐isoprene) rubber cleavage in Streptomyces sp. K30
Authors: Yikmis Meral , Steinbüchel Alexander 
Published: February 2012

AbstractStreptomyces sp. strain K30 induces the formation of an extracellular Lcp (latex‐clearing protein) during poly(cis‐1,4‐isoprene) degradation. To investigate the function of this enzyme in Streptomyces sp. strain K30, the lcp gene was disrupted. This was the first time that the screening for a knock out lcp mutant of Streptomyces sp. strain K30 was successful. The resulting mutant Streptomyces sp. K30_lcpΩKm exhibited reduced growth in liquid mineral salts media containing poly(cis‐1,4‐isoprene) as the sole carbon and energy source. Additionally, there was no detectable Lcp activity on latex overlay agar plates. When Lcp from Streptomyces sp. strain K30 was heterologously expressed in strains TK23 and TK24 of Streptomyces lividans and a strain of S. erythraea with plasmid pIJ6021::lcp, the recombinant strains acquired the ability to cleave synthetic poly(cis‐1,4‐isoprene), confirming the involvement of Lcp in initial polymer cleavage. Specific anti‐LcpK30 IgGs were employed in Western blot analysis to detect the secretion of Lcp in the supernatant. We have conducted an important experiment to demonstrate Lcp activity using the supernatant of these Lcp‐expressing strains in vitro. All three strains obviously secreted a functional Lcp, as indicated by the formation of halo. Functional testing of Lcp with different plasmids in Escherichia coli strains and Pseudomonas strains was, however, not successful.
Identification of a five‐oxidoreductase‐gene cluster from Acetobacter pasteurianus conferring ethanol‐dependent acidification in Escherichia coli
Authors: Garcia‐Armisen Tamara , Vercammen Ken , Rimaux Tom , Vrancken Gino , Vuyst Luc De , Cornelis Pierre 
Published: February 2012

AbstractAcetobacter pasteurianus, a Gram‐negative bacterium belonging to the α‐divison of Proteobacteria, produces acetic acid through ethanol oxidation. A genomic bank of A. pasteurianus 386B DNA was cloned in the low‐copy cosmid pRG930Cm vector and the resulting clones were screened for the production of protease using the skimmed‐milk agar assay whereby a clearing zone around the inoculated spots indicates casein degradation. Several positive clones were selected and restriction analysis revealed that many contained the same inserts. One clone was further analyzed and the cosmid DNA subjected to in vitro transposon insertion. After electroporation, several clones having lost the capacity to cause casein degradation were isolated and the sequence of the transposon‐flanking regions analyzed. The majority of insertions mapped to one gene encoding an NAD(P)+‐dependent aldehyde dehydrogenase (ALDH) of the PNTB superfamily, whereas one insert was found upstream in a gene encoding an ethanol dehydrogenase. Addition of phenol red to the medium confirmed the ethanol‐dependent acidification around the inoculated spots of the clones without transposon insertion, suggesting that casein degradation is due to the production of acetic acid as a result of the combined activities of the alcohol dehydrogenase and ALDH. Quantitative data and pH measurements confirmed a significant acidification, and the presence of acetic acid.