bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chitosan‐Hydroxybenzotriazole Aqueous Solution: A Novel Water‐Based System for Chitosan Functionalization
Authors: Fangkangwanwong Juthathip , Akashi Mitsuru , Kida Toshiyuki , Chirachanchai Suwabun 
Published: June 2006

AbstractSummary: A chitosan‐hydroxybenzotriazole (HOBt) aqueous solution prepared by simply mixing chitosan and HOBt in water provides an effective system to functionalize chitosan in an aqueous environment. This aqueous solution in combination with water‐soluble carbodiimide (WSC) allows the conjugation of functional groups onto chitosan under mild conditions without requiring any organic solvents or acid and heat. In this contribution, a series of model reactions that use a novel water‐based system of chitosan to functionalize the polymer with boc‐L‐phenylalanine, poly(ethylene glycol) methyl ether, and dicarboxylated poly(ethylene glycol) is demonstrated.Chitosan‐HOBt is effectively conjugated with R‐COOH via a water‐soluble carbodiimide (WSC) conjugating agent.magnified imageChitosan‐HOBt is effectively conjugated with R‐COOH via a water‐soluble carbodiimide (WSC) conjugating agent.
Block‐Copolymer‐Assisted Solubilization of Carbon Nanotubes and Exfoliation Monitoring Through Viscosity
Authors: Cotiuga Irina , Picchioni Francesco , Agarwal Uday S. , Wouters Daan , Loos Joachim , Lemstra Piet J. 
Published: June 2006

AbstractSummary: The use of the block copolymers polystyrene‐block‐poly(ethylene oxide) and poly(methyl methacrylate)‐block‐poly(ethylene oxide) is described to assist the direct solubilization of single‐walled carbon nanotubes (SWNTs) into water under ultrasonic irradiation. As compared to surfactants and homopolymers, the block copolymer systems may offer the potential of additional unique morphologies through self‐assembly. TEM and AFM analyses of solution‐cast samples indicate exfoliation and wetting of the SWNTs by the block copolymer. With increasing duration of ultrasonic irradiation, an increase in solution viscosity is initially found, which suggests that it is a convenient indicator of the progress of exfoliation of the SWNTs. With continued intense ultrasonic irradiation, the solution viscosity may decrease apparently because of damage/breakage of the SWNTs.Schematic of the interaction of the PMMA‐b‐PEO block copolymer with the single‐walled carbon nanotubes and the specific viscosity of the system in aqueous solution as a function of sonication time: results from using an ultrasound bath (‐‐‐‐▪‐‐‐‐) or an ultrasound horn (—▴—).magnified imageSchematic of the interaction of the PMMA‐b‐PEO block copolymer with the single‐walled carbon nanotubes and the specific viscosity of the system in aqueous solution as a function of sonication time: results from using an ultrasound bath (‐‐‐‐▪‐‐‐‐) or an ultrasound horn (—▴—).
Comparative Study of patient individual implants from β‐tricalcium phosphate made by different techniques based on CT data
Authors: Peters F. , Groisman D. , Davids R. , Hänel Th. , Dürr H. , Klein M. 
Published: June 2006

AbstractBone substitution or bone augmentation with synthetic materials (e. g. β‐tricalcium phosphate materials, β‐TCP) is usually done by standardized material shapes: block materials can be individually shaped by the surgeon for the specific defect situation. Granular materials are used for more complicated and hardly accessible defect situations. The granulate is mixed with blood. Also injectable putty materials are available.The disadvantage is that none of these material modifications can guarantee a complete and strong press fit contact to the surrounding bone in complicated defect situations, which is essential for a complete and successful bone regeneration. The treatment of complicated defects where mechanical stability is necessary but not viable with a granular material (e. g. large mandibular defects) is therefore difficult.Especially defects where surgeries have a longer planning horizon (e. g. bone tumours, cysts) can be treated with custom made patient individual implants. CT data can be converted to three dimensional CAD/CAM data for shaping or prototyping the implant.For a manufacturer of bone augmentation materials also economical questions are necessary to solve for the decision, whether this technology can be an interesting possibility for the treatment of defect situations as described above.Two different techniques for making patient individual implants from β‐tricalcium phosphate with three‐dimensional fabrication methods were experimentally realised and estimated.Custom made porous scaffolds were produced by using conventional shaping techniques as well as rapid prototyping methods.
Growth of Bone Marrow Stromal Cells on RGD‐Grafted Thermoreversible (NiPAM) Polymers
Authors: Jiang X. , Bai J. , Gittens S. A. , Uludağ H. 
Published: June 2006

AbstractThermoreversible polymers based on N‐isopropylacrylamide (NiPAM) are being explored for tissue engineering applications. The polymers exhibit a solubility change as a function of temperature, which could be utilized for convenient delivery of proteins and cells. Being synthetic, however, the polymer does not allow direct cell attachment. To overcome this limitation, Arginine‐Glycine‐Aspartic Acid (RGD)‐containing peptides were grafted to the polymers in this study. Attachment of rat bone marrow stromal cells (BMSC) on NiPAM‐based polymers was increased by RGD‐grafting, but long‐term cell growth was not as robust as the BMSC grown on tissue culture polystyrene. However, the expression of specific alkaline phosphate activity (ALP/cell; an osteogenic marker) was elevated for cells grown on polymer films and RGD‐grafting was not beneficial in this regard. Whereas basic Fibroblast Growth Factor suppressed the ALP/cell activity, Bone Morphogenetic Protein‐2 stimulated ALP/cells activity for cells grown on polymer films. These results were in line with our previous studies on the osteogenic response of a cell line (C2C12) and stressed the need to improve cell proliferation on NiPAM surfaces, while preserving the beneficial effect of the polymer on osteogenic markers.
Cartilage repair on magnesium scaffolds used as a subchondral bone replacement
Authors: Witte F. , Reifenrath J. , Müller P.P. , Crostack H.‐A. , Nellesen J. , Bach F.W. , Bormann D. , Rudert M. 
Published: June 2006

AbstractDespite the availability of surgical and non‐surgical techniques, the repair of articular cartilage lesions remains a current clinical problem. Especially for the treatment of large osteochondral cartilage defects, the replacement of the subchondral bone plate is a crucial step for optimal cartilage repair. However, no artificial implant material can yet fully restore the properties of the subchondral bone plate. For optimal cartilage tissue repair, mechanical stability for the first two months is essential. Subsequently, a rapid degradation process of the implant material would allow optimal supply of nutrition to the regenerating tissue. To this end, we investigated whether the implantation of an open porous degradable scaffold made of a magnesium alloy (AZ91) could serve as a sufficient temporary replacement of the subchondral bone plate. The results show that this alloy degrades too rapid in vivo to allow sufficient cartilage repair above the scaffold. However, the surrounding cartilage tissue was not negatively affected by the rapid degradation process and new bone formation was observed at the rim of the degrading implant. In conclusion, magnesium scaffolds degrade in vivo but the initial high corrosion rate must be reduced to allow the formation of an appropriate cartilage tissue. Future research will therefore be directed to optimized alloys and additional coating with magnesium fluorides or calcium phosphates like hydroxyapatite.
Postnatal respiratory distress in a dichorial twin with congenital thoracic neuroblastoma after assisted reproduction by intracytoplasmatic sperm injection
Authors: Langer Thorsten , Deeg Karl‐Heinz , Hümmer Peter , Paulides Marios , Beck Jörn‐Dirk , Klinge Jens 
Published: June 2006

AbstractWe report on the case of a female twin with congenital thoracic neuroblastoma after conception via intracytoplasmatic sperm injection (ICSI). Birth occurred at 37 + 1‐week gestation per primary sectio caesarea. Acute respiratory distress necessitated intubation and mechanical ventilation. Ultrasound and magnetic resonance imaging (MRI) showed a mass in the right upper thorax compressing the trachea. The tumor was subtotally excised and histological analysis revealed neuroblastoma. No further treatment was given. The residual primary tumor regressed spontaneously. Four years after diagnosis, both twins are healthy and normally developed. Pediatr Blood Cancer 2007;48:358–360. © 2006 Wiley‐Liss, Inc.
General practice management of people with diabetes requiring insulin
Authors: Sandeman D , Holt R , Chester P 
Published: June 2006

AbstractThe care of patients with diabetes using insulin in the UK is moving inexorably to primary care. To ensure that the service provided is of the highest quality, and meets the needs of patients and the requirements of the National Service Framework, it is important that primary carers are provided with the support they need. While some general practitioners and practice nurses have developed specialist skills, little is known about the needs of general practice to manage the delivery of this service. There is an abundance of available support including training, national and local guidelines and information. How much of this is known to general practice and is designed to accommodate the increasingly busy lives of health care providers in general practice is not clear.This paper presents the results from a survey of general practices in the New Forest Primary Care Trust and identifies needs that GPs and nurses have stated as important for the management of people with diabetes using insulin. Although awareness of the requirements for high quality care is high among GPs and practice nurses, there is a lack of confidence in managing insulin. Both GPs and nurses identified training, simplified guidelines and improved information on insulin products as their priority needs for supporting the service for patients on insulin. Copyright © 2006 John Wiley & Sons, Ltd.
Sweets, fluids and foods in the treatment of mild hypoglycaemia
Authors: Baldwin EJ , Feher MD 
Published: June 2006

AbstractMild hypoglycaemia is a common complication in the treatment of both type 1 and type 2 diabetes. Studies suggest that the standard oral dose to correct mild hypoglycaemia is 20g of carbohydrate in the form of glucose or sucrose. We quantified the portion size and glycaemic index ranking of foods and fluids frequently used to treat hypoglycaemia. These data are presented as a handy measure (‘ user guide’) of foods and fluids suitable for the treatment of mild hypoglycaemia. Many of these foods are readily available. Copyright © 2006 John Wiley & Sons, Ltd.
Assembly of transmembrane helices of simple polytopic membrane proteins from sequence conservation patterns
Authors: Park Yungki , Helms Volkhard 
Published: June 2006

AbstractThe transmembrane (TM) domains of most membrane proteins consist of helix bundles. The seemingly simple task of TM helix bundle assembly has turned out to be extremely difficult. This is true even for simple TM helix bundle proteins, i.e., those that have the simple form of compact TM helix bundles. Herein, we present a computational method that is capable of generating native‐like structural models for simple TM helix bundle proteins having modest numbers of TM helices based on sequence conservation patterns. Thus, the only requirement for our method is the presence of more than 30 homologous sequences for an accurate extraction of sequence conservation patterns. The prediction method first computes a number of representative well‐packed conformations for each pair of contacting TM helices, and then a library of tertiary folds is generated by overlaying overlapping TM helices of the representative conformations. This library is scored using sequence conservation patterns, and a subsequent clustering analysis yields five final models. Assuming that neighboring TM helices in the sequence contact each other (but not that TM helices A and G contact each other), the method produced structural models of Cα atom root‐mean‐square deviation (CA RMSD) of 3–5 Å from corresponding crystal structures for bacteriorhodopsin, halorhodopsin, sensory rhodopsin II, and rhodopsin. In blind predictions, this type of contact knowledge is not available. Mimicking this, predictions were made for the rotor of the V‐type Na+‐adenosine triphosphatase without such knowledge. The CA RMSD between the best model and its crystal structure is only 3.4 Å, and its contact accuracy reaches 55%. Furthermore, the model correctly identifies the binding pocket for sodium ion. These results demonstrate that the method can be readily applied to ab initio structure prediction of simple TM helix bundle proteins having modest numbers of TM helices. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Structural models of the snake venom factor V activators from Daboia russelli and Daboia lebetina
Authors: Segers Kenneth , Rosing Jan , Nicolaes Gerry A.F. 
Published: June 2006

AbstractBlood coagulation factor V (FV) is a multifunctional protein that circulates in human plasma as a precursor molecule which can be activated by thrombin or activated factor X (FXa) in order to express its cofactor activity in prothrombin activation. FV activation is achieved by limited proteolysis after Arg709, Arg1018, and Arg1545 in the FV molecule. The venoms of Daboia russelli and Daboia lebetina contain a serine protease that specifically activates FV by a single cleavage at Arg1545. We have predicted the three‐dimensional structure of these enzymes using comparative protein modeling techniques. The plasminogen activator from Agkistrodon acutus, which shows a high degree of homology with the venom FV activators and for which a high‐quality crystallographic structure is available, was used as the molecular template. The RVV‐V and LVV‐V models provide for the first time a detailed and accurate structure of a snake venom FV activator and explain the observed sensitivity or resistance toward a number of serine protease inhibitors. Finally, electrostatic potential calculations show that two positively charged surface patches are present on opposite sides of the active site. We propose that both FV activators achieve their exquisite substrate specificity for the Arg1545 site via interactions between these exosites and FV. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Electrical and optical properties of ZnO films deposited by ECR‐PECVD
Authors: Choi S. Y. , Kang M. J. , Park T. J. , Tap R. , Schoemaker S. , Willert‐Porada M. 
Published: June 2006

AbstractThe effect of bias voltage on characteristics of ZnO thin films deposited by the electron cyclotron resonance plasma‐enhanced chemical vapor deposition (ECR‐PECVD) method was investigated. The structural, optical and electrical properties of ZnO thin films were studied as a function of O2/dielthylzinc ratio and applied bias voltage. Applying –600 V bias voltage on the substrate during deposition can reduce the sheet resistance by a magnitude of 104 without deteriorating the optical transmittance. The optical band gap was increased from 3.36 to 3.54 eV with bias voltage increase. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Solvent effects on the relative stability of radicals derived from artemisinin: DFT study using the PCM/COSMO approach
Authors: De Araujo M. T. , De M. Carneiro J. W. , Taranto A. G. 
Published: June 2006

AbstractThe PCM/COSMO approach was employed to calculate the relative stability of radicals derived from the antimalarial artemisinin. The calculations were performed in polar (water) and apolar (THF) solvent at the density functional level [B3LYP/6‐31g(d)]. Relative stabilities were calculated by means of isodesmic equations using artemisinin as reference. Replacement of oxygen atoms by CH2 unities was found to decrease the relative stability of the anionic radical intermediates. The degree of destabilization is reduced in the presence of solvent, being less in water than in THF. The dipole moment and the corresponding solvation free energies of these species modulate this effect. Derivatives with inverted stereochemistry are more stable than those with the artemisinin‐like stereochemistry, although the solvent attenuates this stabilization effect. As was found in the in vacuo calculations, the radicals centered on carbon are always more stable than the corresponding radicals centered on oxygen. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Theoretical conformational study of poly(trans‐1, 2‐di(2‐thienyl) ethylene): Effects on the electronic structure and optical properties
Authors: Marçal Nei , Laks Bernardo , Santos Ricardo Paupitz Barbosa Dos 
Published: June 2006

AbstractIn the present study, we investigate the monomer ethylene‐bridged‐bithiophene (TET) and the dimer ethylene‐bridged‐bithiophene (TET)2 to find the more probable conformations of the oligomer and their electronic properties. Geometrical optimizations were carried out at semiempirical level using the Austin method one (AM1) and parametric method 3 (PM3). The electronic transition energies and their associated oscillator strength values are calculated for neutral oligomers. The calculations are conducted using the intermediate neglect of differential overlap Hamiltonian (INDO) in combination with a single configuration–interaction technique in order to include correlation effects. We also employ the negative factor counting (NFC) technique to obtain the electronic density of states (DOS). © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
The association of depression and painful physical symptoms–a review of the European literature
Authors: Garcia-Cebrian A. , Gandhi P. , Demyttenaere K. , Peveler R. 
Published: June 2006

AbstractObjective:The presence of painful physical symptoms may confound the diagnosis of major depressive disorder and may worsen patient prognosis. Epidemiological literature was reviewed to investigate the association between depression and painful physical symptoms.Method:MEDLINE and EMBASE database searches were conducted. Studies where a definable organic basis for pain was given were excluded. The search was unrestricted by language but limited to European studies and countries. After filters were applied, 70 eligible studies were reviewed.Results:The majority of studies reviewed showed an association between depression and painful physical symptoms. Over 40% of all studies examining the association between pain and depression were carried out in pain clinics in secondary care. Very few studies were conducted in psychiatric settings.Conclusion:The findings of this review suggest that painful physical symptoms may be an important part of the depressive syndrome. Although the relationship between depression and painful physical symptoms is not yet fully understood, findings suggest that diagnosis and treatment of depression should involve investigating and treating the full spectrum of symptoms (emotional and physical). Further research in psychiatric and generalist settings is needed to elucidate the relationship between depression and painful physical symptoms as experienced by patients and at the clinical level.
Acetylcholinesterase inhibitor donepezil in the treatment of cognitive deficit in schizophrenia. Subanalysis of the active branch from Czech extended double blind study
Authors: Pérez M. , Tůma I. , Pytela O. , Kadlecová E. , Zemanová M. , Lenderová Z. 
Published: June 2006

AbstractThe article mentions the conclusions of most evidential works investigating donepezil in the treatment of cognitive deficit in schizophrenia. It focuses on an analysis of a sub-group of 20 patients receiving treatment of the donepezil in an extended Czech double-blind placebo controlled study.
Growth and population parameters of ringed seals (Pusa hispida) from Svalbard, Norway, 2002–2004
Authors: Krafft Bjørn A. , Kovacs Kit M. , Frie Anne Kirstine , Haug Tore , Lydersen Christian 
Published: June 2006

AbstractSamples were collected in Svalbard, Norway, during April and May 2002–2004 from 272 ringed seals (Pusa hispida; 62.5% males, 37.5% females) to study growth and population parameters. The age of the animals ranged from 1 to 32 years. Asymptotic values for standard length and body mass were 127.7 ± 1.6 (s.e.) cm and 69.0 ± 2.7 kg for males (maxima: 144 cm and 92 kg) and 127.6 ± 2.3 cm and 68.9 ± 2.5 kg for females (maxima: 141 cm and 91 kg). All animals were sexually mature at an age ≥6 years and the ovulation rate was 0.86. Mean Age at Maturity (MAM) was 4.2 ± 0.2 years for males and 3.5 ± 0.3 years for females, values significantly lower than calculated for ringed seals from the same area 20 years ago. This change in MAM suggests that either the prey base for ringed seals in the area has increased or alternatively that the density of ringed seals has declined, such that more resources are available per capita. If the climate of the Arctic changes in the manner predicted by a host of climate-change scenarios, it is likely to have a strong impact on ringed seal populations in future, although there are no data to suggest that dramatic changes have taken place yet in fish and invertebrate populations in the Svalbard area. Although cause-and-effect cannot be firmly established, there is a possibility that the substantial increase in the number of polar bears (Ursus maritimus) over the past 20 years, since hunting the species in Svalbard ceased in 1973, may have played a role in the observed change in the ringed seal population.
Seabird numbers and prey consumption in the North Atlantic
Authors: Barrett Robert T. , Chapdelaine Gilles , Anker-Nilssen Tycho , Mosbech Anders , Montevecchi William A. , Reid James B. , Veit Richard R. 
Published: June 2006

Abstract
We compared seasonal composition, abundance, and biomass of seabirds between the Northeast (ICES region) and Northwest (NAFO region) Atlantic fisheries regions to identify differences in community assemblage and prey consumption. Seabirds were more abundant in the Northwest Atlantic, but biomass was greater in the Northeast. This disparity resulted from enormous numbers of little auks Alle alle breeding in West Greenland and of Leach's storm-petrels Oceanodroma leucorhoa breeding in Newfoundland, plus large numbers of non-breeding shearwaters Puffinus spp. entering southern NAFO areas in summer. The Northeast Atlantic communities were dominated numerically by northern fulmars Fulmarus glacialis, large auks Uria spp., and the Atlantic puffin Fratercula arctica. Seabirds occupying the North Atlantic consume approximately 11 × 106 t of food annually. Overall consumption rates peak during summer as a result of increased breeding activity and seasonal movements of birds into the North Atlantic. Because of the greater biomass of birds in the northeast, consumption (mainly by piscivores) in ICES areas was approximately 20% higher than that in NAFO areas, where planktivores dominate. NAFO areas had, however, a much greater consumption rate per unit area than ICES areas. Comparative studies such as these could prove informative in assessing large predator responses to the influence of fishing and ocean-scale climate change.