bluuebunny/crossref_metadata_2025_split huggingface dataset:
Are Knee Biomechanics Different in Those With and Without Patellofemoral Osteoarthritis After Anterior Cruciate Ligament Reconstruction?
Authors: Culvenor Adam G. , Schache Anthony G. , Vicenzino Bill , Pandy Marcus G. , Collins Natalie J. , Cook Jill L. , Crossley Kay M. 
Published: February 2014

ObjectivePatellofemoral (PF) osteoarthritis (OA) is prevalent following anterior cruciate ligament reconstruction (ACLR). This study aimed to investigate differences in transverse plane rotation between knees with varus and valgus alignment during gait in people with and without PFOA after ACLR.MethodsThirty‐six individuals who were mean ± SD 9 ± 2 years post‐ACLR (18 radiographic PFOA and 18 no knee OA) participated in this cross‐sectional study. Knee internal‐external rotation angles were measured using a 3‐dimensional motion analysis system during walking and running. Weight‐bearing frontal plane knee alignment, measured with an inclinometer, was used to classify participants as having varus or valgus alignment. Two‐way analysis of covariance was used to assess the effect of both PFOA and frontal plane knee alignment on dynamic knee internal‐external rotation.ResultsSignificant interactions were found between PFOA status and frontal plane alignment on knee internal‐external rotation angles during walking (P = 0.019) and running (P = 0.002). Tests of simple effects revealed that during walking, individuals with valgus alignment and PFOA demonstrated a mean 3.9° (95% confidence interval [95% CI] 0.7, 7.1) less knee internal rotation than those with valgus alignment and no OA. During running this difference increased to 6.1° (95% CI 1.8, 10.4). For individuals with varus alignment, no significant effects were observed.ConclusionLess knee internal rotation during gait was found in individuals with PFOA and valgus alignment. A rotational shift of this magnitude may be sufficient to initiate or accelerate patellofemoral cartilage degeneration. Prospective studies are required to determine if these altered kinematic patterns result from, or contribute to, PFOA development after reconstruction.
Controlling Biological Activity with Light: Diarylethene‐Containing Cyclic Peptidomimetics
Authors: Babii Oleg , Afonin Sergii , Berditsch Marina , Reiβer Sabine , Mykhailiuk Pavel K. , Kubyshkin Vladimir S. , Steinbrecher Thomas , Ulrich Anne S. , Komarov Igor V. 
Published: February 2014

AbstractPhotobiological processes in nature are usually triggered by nonpeptidic chromophores or by modified side chains. A system is presented in which the polypeptide backbone itself can be conformationally switched by light. An amino acid analogue was designed and synthesized based on a reversibly photoisomerizable diarylethene scaffold. This analogue was incorporated into the cyclic backbone of the antimicrobial peptide gramicidin S at several sites. The biological activity of the resulting peptidomimetics could then be effectively controlled by ultraviolet/visible light within strictly defined spatial and temporal limits.
Metal Alkoxide Promoted Regio‐ and Stereoselective CO and CC Metathesis of Allenoates with Aldehydes
Authors: Wang Minyan , Fang Zhao , Fu Chunling , Ma Shengming 
Published: February 2014

AbstractThe reaction of 2,3‐allenoates and aldehydes in the presence of an alkoxide affords alkyl 4,5‐diaryl‐3‐oxo‐2‐propylpent‐4(E)‐enoates and cis‐3,4‐diaryloxetanes through a formal CO and CC metathesis. A mechanism for this reaction has been proposed.
Organocatalytic Asymmetric Formation of Steroids
Authors: Halskov Kim Søholm , Donslund Bjarke S. , Barfüsser Sebastian , Jørgensen Karl Anker 
Published: February 2014

AbstractA novel and simple one‐step approach for the construction of optically active steroids in a highly stereoselective manner by using organocatalysis is presented. The reaction of (di)enals with cyclic dienophiles in the presence of a TMS‐protected prolinol catalyst leads to the construction of important 14 β‐steroids. This new reaction allows an easy access to optically active steroids with a variety of substituents in the A ring in high yields and up to greater than 99 % ee. The reaction has been extended to include the construction of B‐ and D‐homosteroids as well as steroids containing heteroatoms in the B ring. The angular substituent at C13 can be varied and alkyl, ester, and sulfone functionalities are introduced with excellent stereoselectivities. Simple synthetic procedures provide access to a range of naturally occurring steroids such as estrone and related analogues.
Functionalization and hemocompatibility of a styrenic thermoplastic elastomer based on its epoxidized precursor
Authors: Yuan Shuaishuai , Luan Shifang , Yang Huawei , Shi Hengchong , Jin Jing , Song Lingjie , Ma Jiao , Yin Jinghua 
Published: February 2014

ABSTRACTPoly(ethylene glycol) monomethyl ether (mPEG) was introduced into a glycidyl methacrylate‐modified styrenic thermoplastic elastomer graft copolymer via a ring‐opening reaction with the epoxy group. The chemical compositions of the samples were confirmed by Fourier transform infrared spectroscopy, 1H‐NMR spectroscopy, and gel permeation chromatography. X‐ray photoelectron spectroscopy, atomic force microscopy, and water contact angle measurement were used to investigate the surface properties. The results show that the molecular weight of the mPEG monomer had a great effect on the surface properties of the modified samples. The platelet adhesion and protein adsorption of the samples modified with low‐molecular‐weight mPEG were reduced dramatically relative to those of the virgin styrenic thermoplastic elastomer. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40518.
Hypoxia Modulates the Phenotype of Osteoblasts Isolated From Knee Osteoarthritis Patients, Leading to Undermineralized Bone Nodule Formation
Authors: Chang Joan , Jackson Sonya G. , Wardale John , Jones Simon W. 
Published: February 2014

ObjectiveTo investigate the role of hypoxia in the pathology of osteoarthritic (OA) bone by exploring its effect on the phenotype of isolated primary osteoblasts from patients with knee OA.MethodsOA bone samples were collected at the time of elective joint replacement surgery for knee or hip OA. Normal bone samples were collected postmortem from cadaver donors. Primary osteoblasts were isolated from knee OA bone chips and cultured under normoxic or hypoxic (2% O2) conditions. Alkaline phosphatase activity was quantified using an enzymatic assay, and osteopontin and prostaglandin E2 (PGE2) production was assayed by enzyme‐linked immunosorbent assay. Total RNA was extracted from bone and osteoblasts, and gene expression was profiled by quantitative reverse transcription–polymerase chain reaction.ResultsHuman OA bone tissue sections stained positively for carbonic anhydrase IX, a biomarker of hypoxia, and exhibited differential expression of genes that mediate the vasculature and blood coagulation as compared to those found in normal bone. Culture of primary osteoblasts isolated from knee OA bone under hypoxic conditions profoundly affected the osteoblast phenotype, including the expression of genes that mediate bone matrix, bone remodeling, and bone vasculature. Hypoxia also increased the expression of cyclooxygenase 2 and the production of PGE2 by OA osteoblasts. Osteoblast expression of type II collagen α1 chain, angiopoietin‐like 4, and insulin‐like growth factor binding protein 1 was shown to be mediated by hypoxia‐inducible factor 1α. Chronic hypoxia reduced osteoblast‐ mineralized bone nodule formation.ConclusionThese findings demonstrate that hypoxia can induce pathologic changes in osteoblast functionality consistent with an OA phenotype, providing evidence that hypoxia is a key driver of OA pathology.
In situ product recovery of single‐chain antibodies in a membrane bioreactor
Authors: Meier Kristina , Carstensen Frederike , Scheeren Christoph , Regestein Lars , Wessling Matthias , Büchs Jochen 
Published: February 2014

ABSTRACTThe demand for biopharmaceuticals, such as monoclonal antibodies, has risen significantly over the last years. To be competitive, continuous production processes that yield consistent product quality and an economic advantage are desirable. In this study, an in situ product recovery process is described, involving use of submerged membranes to recover single‐chain antibodies from a continuous fermentation of Hansenula polymorpha yeast cells. Reverse‐flow diafiltration (RFD) was applied to prevent cake‐layer formation. Optimal flux ranges for this process could be identified by a systematic flux step method. The RFD process was optimized, preventing mixing of permeate and unreacted substrate: the space–time yield of antibodies using RFD could be tripled. Increase of the fouling related transmembrane pressure was below 45 Pa min−1 for all applied dilution rates, indicating that the filtration process was stable. The membrane as well as the feeding mode of RFD did not influence cell viability nor product concentration. A wide range of dilution rates was successfully tested, demonstrating that this process is suitable for industrial applications. Biotechnol. Bioeng. 2014;111: 1566–1576. © 2014 Wiley Periodicals, Inc.
Power allocation in OFDM cognitive radio relay networks with outdated channel state information
Authors: Biyanwilage Shashika , Gunawardana Upul , Liyanapathirana Ranjith 
Published: February 2014

SummaryIn this paper, we study power allocation in OFDM cognitive radio (CR) relay networks. The objective of power allocation is to maximize the instantaneous capacity of the CR network. It is assumed that the available channel state information between the secondary and primary users is an outdated but correlated version of the actual instantaneous channel state information. Optimal power allocation schemes are developed for both decode‐and‐forward and amplify‐and‐forward relay assisted CR transmission, assuming that the primary users are subject to average interference constraints and the CR transmitters are subject to maximum transmit power constraint. In addition, suboptimal power allocation schemes with reduced complexity are also proposed. Performance of the proposed schemes is compared with uniform power allocation and numerical results confirm that the proposed power allocation schemes achieve significant capacity improvement in comparison to uniform power loading. Furthermore, the proposed suboptimal power allocation schemes can be used as less complex alternatives for optimal power allocation with some capacity degradation. Copyright © 2014 John Wiley & Sons, Ltd.
N‐Methyl‐21‐thiaporphyrins
Authors: Kaur Tejinder , Lee Way‐Zen , Ravikanth Mangalampalli 
Published: February 2014

AbstractWe synthesized five N‐methyl‐meso‐tetraaryl‐21‐thiaporphyrins in 55–60 % yield by treating the appropriate meso‐tetraaryl‐21‐thiaporphyrin with CH3I. The N‐methyl‐21‐thiaporphyrins were characterized by HRMS, 1D and 2D NMR spectroscopy, absorption spectroscopy, fluorescence spectroscopy, and electrochemical techniques, and the structure of one of the compounds was obtained by X‐ray crystallography. 1D and 2D NMR spectroscopy were used to identify all of the resonances observed in the 1H NMR spectra of the N‐methyl‐21‐thiaporphyrins. NMR studies indicated that the methylation occurred at the pyrrole ring that is opposite to the thiophene ring. In the 1H NMR spectra, the methylation resulted in significant upfield shifts of the pyrrole and thiophene protons; the maximum shifts were noted for the protons of the N‐methylated pyrrole ring of the N‐methyl‐21‐thiaporphyrins. The X‐ray structure of one of the N‐methyl‐21‐thiaporphyrins revealed significant deviation of the N‐methylated pyrrole ring from the reference plane defined by the four meso carbon atoms, and the porphyrin ring is strongly distorted compared to the 21‐thiaporphyrin ring. The absorption studies revealed that the N‐methyl‐21‐thiaporphyrins showed four Q bands and one strong Soret band, which were bathochromically shifted compared to those of the 21‐thiaporphyrins. The electrochemical studies on the N‐methyl‐21‐thiaporphyrins indicated that the oxidation potentials became less positive and there were negligible shifts in the reduction potentials; the HOMO–LUMO energy gap decreased compared with that of the 21‐thiaporphyrins. The N‐methyl‐21‐thiaporphyrins are weakly fluorescent with low quantum yields and singlet‐state lifetimes. The spectral and electrochemical studies indicated that N‐methylation of the pyrrole ring of 21‐thiaporphyrins significantly alters the electronic properties of the 21‐thiaporphyrin macrocycle.
Kinetic modeling of laboratory CO2‐exposure experiments performed on whole rock reservoir samples
Authors: Fischer Sebastian , De Lucia Marco , Liebscher Axel 
Published: February 2014

AbstractMineralogical and geochemical observations from laboratory CO2‐exposure experiments on reservoir rocks are compared with predictions from geochemical modeling that was performed using PHREEQC software. The Pitzer‐based Eq 3/6 thermodynamic database, provided by Quintessa Ltd., was applied. For kinetic modeling, a Lasaga‐type rate equation was implemented and different models were parameterized taking kinetic rate law parameters from literature. Based on previous modeling studies a modified inverse modeling approach is presented here. This comprises several different Fe‐proxies and improved statistical ranking preferences that were implemented in particular to better match modeled and measured concentrations of dissolved K+, Fe2+ and Al3+. Compared to the previous approach, the presented modeling results are in good (better) agreement with experimental data. Systematic discrepancies between modeling and observation still occur regarding K‐bearing mineral phases and corresponding K+ brine concentrations. Despite missing correlation between K+ and Cl− concentrations, potential reasons for these discrepancies may be increased K+ brine concentrations during the experiments due to dissolution of K‐rich salt(s), such as sylvite. Much better matches were generated for dissolved Fe2+ concentrations. Goethite mainly controls the chemical behavior of dissolved Fe2+ in kinetic simulations. Based on both the available equilibrium and kinetic modeling results, the ultimate fate of dissolved Al3+ and the analysis of Al‐bearing mineral phases potentially controlling dissolved Al3+ brine concentrations cannot be conclusively determined. The overall best ranked kinetic model comprises anhydrite, dolomite, goethite, K‐feldspar and kaolinite. Despite minor inconsistencies dissolved Fe2+, Al3+ and Si4+ were in particular much better reproduced by the best ranked kinetic models.
Clinical outcome of patients with carcinoma ex pleomorphic adenoma of the parotid gland: A comparative study from a single tertiary center
Authors: Lim Chwee Ming , Hobson Candace , Kim Seungwon , Johnson Jonas T. 
Published: February 2014

AbstractBackgroundCarcinoma ex pleomorphic adenoma (CXPA) of the parotid gland is a high‐grade cancer and the prognosis of this cancer has not been compared with non‐CXPA high‐grade primary parotid cancer.MethodsRetrospective medical chart review of patients with surgically treated high‐grade primary parotid cancer (21 CXPA and 52 non‐CXPA) was performed with correlation with disease‐specific survival, locoregional recurrence, and distant recurrence.ResultsDespite having similar stage of cancer and extent of surgical resection, patients with CXPA had a lower disease‐specific survival compared to non‐CXPA high‐grade primary parotid cancer (p = .02). Salivary duct cancer (SDC) was the commonest histologic variant in both cohorts and around 40% of patients with SDC died of distant recurrence that occurred within 3 years from diagnosis.ConclusionCXPA of the parotid gland is a more aggressive cancer compared to non‐CXPA high‐grade primary parotid cancer. SDC was associated with a high chance of delayed distant recurrence, which contributed directly to the mortality of this cancer. © 2014 Wiley Periodicals, Inc. Head Neck 37: 543–547, 2015
Evaluation of oriented electrospun fibers for periosteal flap regeneration in biomimetic triphasic osteochondral implant
Authors: Liu Xudong , Liu Shen , Liu Shenghe , Cui Wenguo 
Published: February 2014

AbstractOsteochondral defects represent a serious clinical problem. Although the cell‐scaffold complexes have been reported to be effective for repairing osteochondral defects, a periosteal flap is frequently needed to arrest leakage of the implanted cells into the defect and to contribute to the secretion of cytokines to stimulate cartilage repair. The electrospun mesh mimicking the function of the flap assists tissue regeneration by preventing cell leakage and merits favorable outcomes in the cartilaginous region. In this study, an oriented poly(ε‐caprolactone) (PCL) fibrous membrane (OEM) was fabricated by electrospinning as a periosteal scaffold and then freeze‐dried with a collagen type I and hyaluronic acid cartilage scaffold (CH) and finally, freeze‐dried with a tricalcium phosphate (TCP) bone substratum. Scanning electron microscopic images show obvious microstructure formation of the trilayered scaffolds, and electrospun fibrous membranes have an oriented fibrous network structure for the periosteal phase. Also shown are opened and interconnected pores with well designed three‐dimensional structure, able to be bound in the CH (chondral phase) and TCP (osseous phase) scaffolds. In vitro results showed that the OEM can promote the orientation of bone marrow mesenchymal stem cell (BMSCs) and BMSCs can penetrate into the CH and TCP. After successfully combining the BMSCs, the tissue‐engineered cartilage which contained the OEM and TCP complex was successfully used to regenerate the osteochondral defects in the rabbit model with greatly improved repair effects. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 1407–1414, 2014.
Decreased blood loss reduces postoperative complications in resection for hepatocellular carcinoma
Authors: Aramaki Osamu , Takayama Tadatoshi , Higaki Tokio , Nakayama Hisashi , Ohkubo Takao , Midorikawa Yutaka , Moriguchi Masamichi , Matsuyama Yutaka 
Published: February 2014

AbstractBackgroundThe correlation between blood loss and the risk of postoperative complications was unclear in patients undergoing resection of hepatocellular carcinoma (HCC).MethodsWe studied 539 patients who had resection of HCC. Postoperative complications were recorded according to the modified Clavien‐Dindo classification. Variables were compared between patients with grade III to V complications and those with no or grade I to II. A spline regression analysis was used to estimate the probability of grade III to V complications.ResultsAmong variables, blood loss (P = 0.0001), operating time (P = 0.0001), blood transfusion (P = 0.0001), and tumor size (P = 0.02) differed significantly between patients with grade III to V and those with no or I to II. Multivariate analysis revealed that the factor most strongly related to complications was blood loss (odds ratio 1.68; 95% confidence interval [CI] 1.45–1.96, P = 0.0001). Spline regression analysis showed that an increase in blood loss was accompanied by increase in the risk of complication; when the estimated probability of grade III to V complications exceeded 50% (95% CI 30.0–70.0), the corresponding blood loss was 820 ml.ConclusionDecrease in blood loss in resection of HCC is accompanied by reduced risk of complications. Surgeons need to minimize blood loss as less as 820 ml.
Achieving Competitiveness in Greek Accommodation Establishments during Recession
Authors: Pappas Nikolaos 
Published: February 2014

AbstractThe article examines the strategies that Greek hotels have implemented to strengthen their competitiveness during recession. The research is based on a nationwide e‐mail survey to hospitality managers/owners. The results reveal that the most important perceived competitiveness factor is cost reduction and implementation of actions against crisis, followed by innovation, human resource management and marketing. The study also proposes actions that can improve the competitiveness of accommodation establishments. The article helps fill the gaps in our understanding of how hospitality firms tackle competition during crises, and suggests managerial policies that can help hospitality firms to strengthen their positioning and competitiveness during crises. Copyright © 2014 John Wiley & Sons, Ltd.
Dual Functionalization of Nanostructures of Block Copolymers with Quantum Dots and Organic Fluorophores
Authors: Chae Seungyong , Kim Jeong‐Hee , Theato Patrick , Zentel Rudolf , Sohn Byeong‐Hyeok 
Published: February 2014

Dual functionalization of nanostructures of block copolymers by simultaneous incorporation of two functionalities into the nanostructures is demonstrated. For this purpose, a blending strategy of two block copolymers is employed, which have the same basic chemical structure for each block but differ in small amounts of functional moieties in one of the blocks. Block copolymers containing thiol and fluorophore functionalities are synthesized, utilizing a block copolymer that features a reactive block of activated esters. With thiol‐functionalized block copolymers, selective incorporation of quantum dots (QDs) to lamellar nanostructures is first validated by transmission electron microscopy. Fluorophore functionalization of lamellar nanostructures is also confirmed with fluorophore‐anchored block copolymers by photoluminescence spectroscopy. Then, with a blending strategy of two functionalized block copolymers, dual functionalization of lamellar nanostructures of block copolymers is induced by simultaneous incorporation of QDs and organic fluorophores, which exhibit fluorescence resonance energy transfer due to nanoscale confinement.
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Necessary conditions for discontinuities of multidimensional persistent Betti numbers
Authors: Cerri Andrea , Frosini Patrizio 
Published: February 2014

AbstractTopological persistence has proven to be a promising framework for dealing with problems concerning the analysis of data. In this context, it was originally introduced by taking into account 1‐dimensional properties of data, modeled by real‐valued functions. More recently, topological persistence has been generalized to consider multidimensional properties of data, coded by vector‐valued functions. This extension enables the study of multidimensional persistent Betti numbers, which provide a representation of data based on the properties under examination. In this contribution, we establish a new link between multidimensional topological persistence and Pareto optimality, proving that discontinuities of multidimensional persistent Betti numbers are necessarily pseudocritical or special values of the considered functions. Copyright © 2014 John Wiley & Sons, Ltd.
Robust spectral method for numerical valuation of european options under Merton's jump‐diffusion model
Authors: Pindza E. , Patidar K.C. , Ngounda E. 
Published: February 2014

AbstractWe propose a novel numerical method based on rational spectral collocation and Clenshaw–Curtis quadrature methods together with the “” transformation for pricing European vanilla and butterfly spread options under Merton's jump‐diffusion model. Under certain assumptions, such model leads to a partial integro‐differential equation (PIDE). The differential and integral parts of the PIDE are approximated by the rational spectral collocation and the Clenshaw–Curtis quadrature methods, respectively. The application of spectral collocation method to the PIDE leads to a system of ordinary differential equations, which is solved using the implicit–explicit predictor–corrector (IMEX‐PC) schemes in which the diffusion term is integrated implicitly, whereas the convolution integral, reaction, advection terms are integrated explicitly. Numerical experiments illustrate that our approach is highly accurate and efficient for pricing financial options.Copyright © 2014 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 30: 1169–1188, 2014