bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of an isomer of the renieramycin skeleton from L‐tyrosine
Authors: Liu Wei , Dong Wen Fang , Liao Xiang Wei , Guan Bao He , Liu Zhan Zhu 
Published: January 2011

AbstractA new approach that tried to obviate the use of bromine protection groups was studied to synthesize (−)‐renieramycin G from L‐tyrosine. It was found that the first intermolecular Pictet–Spengler reaction proceeded successfully to give the correct tetrahydroisoquinoline precursor 6. However, the second intramolecular Pictet–Spengler cyclization step failed to give the desired product, and an isomer of the skeleton of the renieramycins was obtained via 12 steps starting from L‐tyrosine. J. Heterocyclic Chem., (2011).
An alternative total synthesis of pentosidine
Authors: Liu Yahua , Zhang Weihan , Sayre Lawrence M. 
Published: January 2011

AbstractPentosidine, a fluorescent advanced glycation endproduct that serves as a biomarker of diabetic complications, kidney dysfunction, oxidative stress, and aging and age‐related diseases, was synthesized from 2,3‐diaminopyridine and benzyloxycarbonyl (Cbz) protected chiral amino acidsNα‐Cbz‐lysine andNδ‐Cbz‐ornithine. Regioselective alkylation of 2‐(methylthio)imidazo[4,5‐b]pyridine, chlorination of methylthio group, and amination of 2‐chloro‐imidazo[4,5‐b]pyridine are the key steps. Hydantoin protection of amino acids was used and the deprotection under acidic condition was achieved in the presence of glycine. J. Heterocyclic Chem., (2011).
Morphology of hamstring torque‐time curves following acl injury and reconstruction: mechanisms and implications
Authors: Bryant Adam L. , Clark Ross A. , Pua Yong‐Hao 
Published: January 2011

AbstractThe purposes of this study were (i) to examine the effects of anterior cruciate ligament (ACL) status on hamstring force steadiness, peak hamstring strength, quadriceps (antagonist) activation, and physical performance, and (ii) to evaluate the associations of physical performance with hamstring steadiness and hamstring strength. Thirteen subjects with unilateral deficiency of the ACL (ACLD), 39 matched subjects with unilateral reconstructed ACL (ACLR; n = 25 with bone‐patella tendon‐bone (ACLR‐PT) graft and n = 14 with combined semitendinosus and gracilis tendon (ACLR‐STGT) graft) and 33 control subjects participated. Each subject performed maximal‐effort isokinetic knee flexion repetitions at 180° s−1 with electromyography (EMG) electrodes attached to their medial and lateral quadriceps muscles. Physical performance was assessed using the single‐limb long hop for distance. Wavelet‐derived mean instantaneous frequency (Mif) of flexor torque‐time curves was significantly (p < 0.05) higher (i.e., less smooth) in ACLR‐STGT subjects compared to the ACLD, ACLR‐PT and control subjects. No significant differences existed for peak hamstrings strength (i.e., peak torque produced) or quadriceps antagonist EMG activity. Positive correlations were identified between hamstrings force steadiness and quadriceps antagonist activity for ACLD (r = 0.797), ACLR‐PT (r = 0.467), and ACLR‐STGT (r = 0.628) subjects. For ACLR‐STGT subjects, reduced hamstrings force steadiness associated with poorer long‐hop performance (r = −0.695). Reduced steadiness amongst ACLR‐STGT subjects may reflect motor output variability of the antagonist (i.e., quadriceps dyskinesia) and/or agonist musculature—a maladaptive feature which potentially contributes to poorer single‐limb hop performance. Measures of hamstring force steadiness in combination with traditional measures of peak hamstring strength provide valuable clinical information regarding knee joint function following ACL injury/ACLR. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29:907–914
Exercise enhances angiogenesis during bone defect healing in mice
Authors: Holstein Joerg H. , Becker Steven C. , Fiedler Martin , Scheuer Claudia , Garcia Patric , Histing Tina , Klein Moritz , Pohlemann Tim , Menger Michael D. 
Published: January 2011

AbstractThe aim of the present study was to investigate the effect of exercise on angiogenesis during bone defect healing in mice. We evaluated angiogenesis during cranial bone defect healing by intravital fluorescence microscopy (IVM) at days 0–21. To characterize the type of bone repair, we performed additional histomorphometric analyses at days 3–15. IVM was conducted in mice, which were housed in cages supplied with running wheels (exercise group; n = 7) and compared to IVM results of mice, which were housed in cages without running wheels (controls; n = 7). In the exercise group, we additionally performed correlation analyses between results of the IVM and the running distance. IVM showed an accelerated decrease of bone defect area in the exercise group compared to the control group. This was associated with a significantly higher blood vessel diameter in animals undergoing exercise at days 9 and 12 and a significant correlation between running distance and blood vessel density at day 9 (r = 0.74). Histomorphometry showed osseous bridging of the defect at day 9. The newly woven bone was covered by a neo‐periosteum containing those blood vessels, which were visible by IVM. We conclude that exercise accelerates bone defect healing and stimulates angiogenesis during bore repair. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29: 1086–1092, 2011
Separation and purification of ergosterol and stigmasterol in Anoectochilus roxburghii (wall) Lindl by high‐speed counter‐current chromatography
Authors: Huang Liying , Cao Yangyuan , Xu Hui , Chen Guonan 
Published: January 2011

AbstractErgosterol and stigmasterol are the most common phytosterols in the traditional Chinese medicine. They are two major sterol compounds in Anoectochilus roxburghii (wall) Lindl (A. roxburghii) and have been proved to have many important biological activities. A method by using high‐speed counter‐current chromatography (HSCCC) has been successfully developed for separation and purification of ergosterol and stigmasterol in A. roxburghii simultaneously in this paper. The optimum conditions used in this method were as follows: The two‐phase solvent system consisted of n‐hexane–ethylacetate–butanol–methanol–water (3.5:0.3:0.5:2.5:0.3, v/v); the rotation speed was 900 rpm; the flow rate of the lower phase was 1.5 mL/min. About 36.5 mg of ergosterol and 43.6 mg of stigmasterol were obtained from 100 g of A. roxburghii. The purity of ergosterol and stigmasterol was examined to be 92.0 and 95.5%, respectively, by using HPLC. The chemical structures of these components were identified by UV spectra, FT‐IR, MS, 1H‐NMR and 13C‐NMR. The results demonstrated that high‐speed counter‐current chromatography was a feasible method to separate and purify ergosterol and stigmasterol from the herb. This separation and purification method was more effective than many other conventional techniques.
Low Thrombogenicity Coating of Nonwoven PET Fiber Structures for Vascular Grafts
Authors: Dimitrievska Sashka , Maire Marion , Diaz‐Quijada Gerardo A. , Robitaille Lucie , Ajji Abdellah , Yahia L'Hocine , Moreno Maria , Merhi Yahye , Bureau Martin N. 
Published: January 2011

AbstractVascular PET grafts (Dacron) have shown good performance in large vessels (≥6 mm) applications. To address the urgent unmet need for small‐diameter (2–6 mm) vascular grafts, proprietary high‐compliance nonwoven PET fiber structures were modified with various PEG concentrations using PVA as a cross‐linking agent, to fabricate non‐thrombogenic mechanically compliant vascular grafts. The blood compatibility assays measured through platelet adhesion (SEM and mepacrine dye) and platelet activation (morphological changes, P‐selectin secretion, and TXB2 production) demonstrate that functionalization using a 10% PEG solution was sufficient to significantly reduce platelet adhesion/activation close to optimal literature‐reported levels observed on carbon‐coated ePTFE. magnified image
Isoconversional Glass Transition Kinetics and Fragility Determination of Poly[(ethylene 2,6‐naphthalate)‐co‐(butylene 2,6‐naphthalate)] Random Copolymers
Authors: Papageorgiou George Z. , Achilias Dimitris S. , Karayannidis George P. 
Published: January 2011

AbstractIsoconversional methods were applied to DSC data to determine the effective activation energy, ΔE, for the glass transition in a series of PEBN random copolymers. It was revealed that ΔE varies rather significantly throughout the process, decreasing with temperature as well as with the amount of BN units in the copolymer chain. Moreover, the dynamic fragility, m, of PEBN copolymers was evaluated. Employing the scanning rate dependency of Tg it was found that as the amount of BN units in the copolymer increases, m gets lower values denoting more strong materials, while the inverse was concluded by applying the extrapolation of configurational entropy to zero method. Results of the later method were verified by tensile mechanical property measurements of the copolymers. magnified image
Macromolecular Recognition: Discrimination between Human and Bovine Serum Albumins by Cyclodextrins
Authors: Oi Wataru , Isobe Mio , Hashidzume Akihito , Harada Akira 
Published: January 2011

AbstractThe interactions of cyclodextrins (CDs) with human serum albumin (HSA) and bovine serum albumin (BSA) were investigated by two‐dimensional nuclear Overhauser effect spectroscopy (2D NOESY), steady state fluorescence, isothermal titration calorimetry, and circular dichroism spectroscopy. 2D NOESY indicates that α‐CD and β‐CD, but not γ‐CD, interact with the aromatic amino acid residues on HSA. On the other hand, the 2D NOESY signals between CDs and BSA are not significantly correlated. Hence, CDs can discriminate the subtle protein structural differences of HSA and BSA. magnified image
A Lipase‐Responsive Vehicle Using Amphipathic Polymer Synthesized with the Lipase as Catalyst
Authors: Ge Jun , Lu Diannan , Yang Cheng , Liu Zheng 
Published: January 2011

AbstractWe describe an enzyme‐responsive polymeric vehicle, which is of great interest in controlled drug delivery, biosensing, and other related areas. The polymer synthesized using lipase as catalyst in DMSO has a favorable molecular structure that is quickly hydrolyzed by lipase in aqueous phase, and allows a fast release of encapsulated molecules. magnified image
Direct visualization of Parkinson's disease by in vivo human brain imaging using 7.0T magnetic resonance imaging
Authors: Cho Zang‐Hee , Oh Se‐Hong , Kim Jong‐Min , Park Sung‐Yeon , Kwon Dae‐Hyuk , Jeong Hye‐Jin , Kim Young‐Bo , Chi Je‐Geun , Park Chan‐Woong , Huston John , Lee Kendall H. , Jeon Beom S. 
Published: January 2011

AbstractParkinson's disease (PD) is a neurodegenerative disorder resulting from progressive loss of dopaminergic neurons in the substantia nigra (SN) pars compacta. Therefore, imaging of the SN has been regarded to hold greatest potential for use in the diagnosis of PD. At the 7.0T magnetic resonance imaging (MRI), it is now possible to delineate clearly the shapes and boundaries of the SN. We scanned eight early and two advanced PD patients, along with nine age‐matched control subjects, using a 7.0T MRI in an attempt to directly visualize the SN and quantify the differences in shape and boundaries of SN between PD subjects in comparison with the normal control subjects. In the normal controls, the boundaries between the SN and crus cerebri appear smooth, and clean “arch” shapes that stretch ventrally from posterior to anterior. In contrast, these smooth and clean arch‐like boundaries were lost in PD subjects. The measured correlation analyses show that, in PD patients, there is age‐dependent correlation and substantially stronger UPDRS motor score‐dependent correlation. These results suggest that, by using 7.0T MRI, it appears possible to use these visible and distinctive changes in morphology as a diagnostic marker of PD. © 2011 Movement Disorder Society
A significant wind shear event leading to aircraft diversion at the Hong Kong international airport
Authors: Chan P. W. 
Published: January 2011

AbstractA significant wind shear event occurred in the early morning of 27 December 2009 at the Hong Kong International Airport (HKIA), leading to the diversion of three aircraft to the airport of Shenzhen (about 39 km to the north‐northwest of HKIA). This paper documents the meteorological observations and predictions for the event. The significant wind shear arose from disruption of the prevailing easterly to southeasterly flow by the complex terrain to the south of the airport. It was well captured by the Doppler Light Detection and Ranging (LIDAR) systems at HKIA and, as such, the aircraft were given sufficient warning about the occurrence of significant wind shear. The headwind changes along the glide paths as measured by the LIDAR were consistent with the aircraft measurements. The observations of the remote‐sensing instruments during the event, including the LIDAR, are described in the paper. Moreover, this paper discusses the possibility of including wind shear forecast information for flight planning purpose for this particular case. The forecast wind field near HKIA based on a high‐resolution numerical weather prediction (NWP) model is described. For the present wind shear event, it appears that the occurrence of terrain‐disrupted airflow near HKIA may be forecast about 6 h ahead. The timing of significant wind shear is, however, not reproduced well in the NWP forecast. Copyright © 2011 Royal Meteorological Society
Clinical Services in Environmental Pediatrics
Authors: Paulson Jerome A. , Gordon Lauren 
Published: January 2011

AbstractPediatric healthcare providers are confronted with environmental health problems frequently: the child with asthma exacerbated by the odor of paint in school or mouse antigen at home, the family who wants to know the risks and benefits of using different types of sunblock, or the community that asks the provider for advice on the potential health impacts of building the new elementary school next to the on‐ramp to the interstate highway. Pediatric providers have not been well trained to deal with these questions in medical or nursing schools, residency training, or continuing‐education settings. This article provides guidance on history taking, the physical examination, laboratory evaluations of patients and the environment, and making an assessment about and managing environmental health problems. Pediatric Environmental Health Specialty Units are discussed as a source of consultation and referral. The identification and utilization of evidence‐based resources are stressed and clinicians are cautioned about non–evidence‐based assessments such as clinical ecology and hair analysis and non–evidence‐based management strategies such as chelation for autism. Mt Sinai J Med 78:11–21, 2011. © 2011 Mount Sinai School of Medicine
A dual algorithm for shakedown analysis of plate bending
Authors: Tran Thanh Ngoc 
Published: January 2011

AbstractIn this paper, the duality between the lower and the upper bound shakedown analyses of plate bending is presented. Based on the duality theory, the shakedown load multiplier formulated by static theorem is proved actually to be the dual form of the shakedown load multiplier formulated by kinematic theorem. A dual algorithm based upon the von Mises yield criterion and a non‐linear optimization procedure is then developed to compute simultaneously both the upper and lower bounds of the plastic collapse limit and the shakedown limit. The DKQ plate bending element is used to discrete the problem field. Numerical examples are presented to show the excellent convergence and accuracy of solutions obtained by the present method. Copyright © 2011 John Wiley & Sons, Ltd.
A stabilized co‐rotational curved quadrilateral composite shell element
Authors: Li Z. X. , Liu Y. F. , Izzuddin B. A. , Vu‐Quoc L. 
Published: January 2011

AbstractA new curved quadrilateral composite shell element using vectorial rotational variables is presented. An advanced co‐rotational framework defined by the two vectors generated by the four corner nodes is employed to extract pure element deformation from large displacement/rotation problems, and thus an element‐independent formulation is obtained. The present line of formulation differs from other co‐rotational formulations in that (i) all nodal variables are additive in an incremental solution procedure, (ii) the resulting element tangent stiffness is symmetric, and (iii) is updated using the total values of the nodal variables, making solving dynamic problems highly efficient. To overcome locking problems, uniformly reduced integration is used to compute the internal force vector and the element tangent stiffness matrix. A stabilized assumed strain procedure is employed to avoid spurious zero‐energy modes. Several examples involving composite plates and shells with large displacements and large rotations are presented to testify to the reliability, computational efficiency, and accuracy of the present formulation. Copyright © 2011 John Wiley & Sons, Ltd.
Validation of the needs assessment for advanced lung cancer patients (NA‐ALCP)
Authors: Schofield Penelope , Gough Karla , Ugalde Anna , Dolling Lara , Aranda Sanchia , Sanson‐Fisher Rob 
Published: January 2011

AbstractObjective: The Needs Assessment for Advanced Cancer Patients (NA‐ACP) is a 132‐item self‐report questionnaire designed to assess the seven needs domains of patients with advanced, incurable cancer. This study aimed to evaluate the short derivative form of that questionnaire with advanced lung cancer patients.Methods: Item factor loadings, item test–retest data and response distributions were used to retain or reject items from the original NA‐ACP scale. This resulted in 38 items being maintained, preserving the original subscales. The response scale was simplified following feedback from patients. 108 people with advanced lung cancer completed the shortened NA‐ALCP along with measures of psychological distress (HADS, DT) and quality of life (EORTC QLQ‐C30).A‐prioripredictions were made for divergent and convergent validity.Results: Internal consistency coefficients were satisfactory for six of seven subscales, range 0.71–0.95. Correlations between NA‐ALCP and HADS, DT and EORTC‐QLQ‐C30 provided support for 11 of the 22 divergent (r= 0.13–0.27) and convergent predictions (r= 0.45–0.71).Conclusions: Subscales of the NA‐ALCP demonstrated internal reliability consistent with the original scale. Results provided supporting evidence for divergent and convergent validity. This study indicates that the NA‐ALCP is psychometrically robust, easily understood and one‐quarter the length of the original version. Copyright © 2011 John Wiley & Sons, Ltd.
Cognitive dysfunction and cancer: which consequences in terms of disease management?
Authors: Joly Florence , Rigal Olivier , Noal Sabine , Giffard Bénédicte 
Published: January 2011

AbstractObjectives: The aim of this review is to stress the importance of cognitive dysfunction in cancer survivors, and to discuss the way of assessing and managing these troubles in clinical practice.Method: Original studies and reviews reporting the effect of cancer and chemotherapy on cognition and published since January 2000 were selected from the Medline® database using ‘cognition’ or ‘cognitive function’ and ‘cancer’ as subject headings.Results: Main reports concerned women with advanced breast cancer or children with hematological or brain cancers. Overall, chemotherapy was found to be associated with subtle and transient cognitive dysfunctions, which were detectable only with neuropsychological testing and affected most particularly memory, concentration and speed of information processing. Some factors associated with the patient, like depression, may favor cognitive impairment, while the role of others, like age or educational level, remains to be defined. Screening of patients at risk remains limited due to the lack of standardized neuropsychological tests in clinical oncology practice. Few studies have addressed the benefits of interventional strategies but methylphenidate, modafinil and erythropoietin, as well as rehabilitation in children, have shown encouraging results. Formal studies assessing the value of a multidisciplinary approach to detect and manage cognitive impairment must be recommended.Conclusion: Cognitive dysfunction induced by cancer or the treatment represents a real challenge in clinical practice. Based on limited published data, few clinical recommendations can be made regarding prevention, evaluation and management of this trouble. Longitudinal studies must be conducted to evaluate its real impact on quality of life. Copyright © 2011 John Wiley & Sons, Ltd.
Identification of functional motions in the adenylate kinase (ADK) protein family by computational hybrid approaches
Authors: Armenta‐Medina Dagoberto , Pérez‐Rueda Ernesto , Segovia Lorenzo 
Published: January 2011

AbstractBased on integrative computational hybrid approaches that combined statistical coupling analysis (SCA), molecular dynamics (MD), and normal mode analysis (NMA), evolutionarily coupled residues involved in functionally relevant motion in the adenylate kinase protein family were identified. The hybrids identified four top‐ranking site pairs that belong to a conserved hydrogen bond network that is involved in the enzyme's flexibility. A second group of top‐ranking site pairs was identified in critical regions for functional dynamics, such as those related to enzymatic turnover. The high consistency of the results obtained by SCA with NMA (SCA.NMA) and by SCA.MD hybrid analyses suggests that suitable replacement of the matrix of cross‐correlation analysis of atomic fluctuations (derived by using NMA) with those based on MD contributes to the identification of such sites by means of a fast computational calculation. The analysis presented here strongly supports the hypothesis that evolutionary forces, such as coevolution at the sequence level, have promoted functional dynamic properties of the adenylate kinase protein family. Finally, these hybrid approaches can be used to identify, at the residue level, protein motion coordination patterns not previously observed, such as in hinge regions. Proteins 2011. © 2011 Wiley‐Liss, Inc.
Electron ionization mass spectral studies of bridgehead‐substituted norbornan‐2‐ones: camphor derivatives
Authors: Teso Vilar Enrique , Fraile Amelia García , Cerero Santiago de la Moya , Martínez‐Ruiz Paloma , Jiménez Florencio Moreno 
Published: January 2011

AbstractThe electron ionization (EI) mass spectra of a series of bridgehead‐substituted 3,3‐dimethylnorbornan‐2‐ones, derived from natural (1R)‐(+)‐camphor, have been studied and their cleavage mechanisms rationalized on the basis of the substituent shifts as well as on the identification of relevant peaks through accurate mass measurements and collision‐induced dissociation (CID) tandem mass spectrometric experiments. The fragmentation patterns are very dependent on both the structural nature and the electronic properties of the bridgehead substituent. The driving force for the main fragmentation pathways are competitive cleavages of the C(1)–C(2) and C(2)–C(3) bonds directed by the bridgehead substituent and either the gem‐dimethyl or carbonyl groups. These cleavages lead to distonic ions in which the charge is preferentially located either at the C(1), C(2) or C(3) positions depending on the electronic character and structural nature of the bridgehead substituent. This charge distribution determines the subsequent rearrangements and fragmentations. Copyright © 2011 John Wiley & Sons, Ltd.