bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bioactivation of porous polyurethane scaffolds using fluorinated RGD surface modifiers
Authors: Blit Patrick H. , Shen Yi Hao , Ernsting Mark J. , Woodhouse Kimberly A. , Santerre J. Paul 
Published: April 2010

AbstractBiomaterial scaffolds for tissue engineering require appropriate cell adhesion, proliferation, and infiltration into their three‐dimensional (3D) porous structures. Surface modification techniques have the potential to enhance cell infiltration into synthetic scaffolds while retaining bulk material properties intact. The objective of this work was to assess the potential of achieving a uniform surface modification in 3D porous constructs through the blending of surface‐modifying additives known as bioactive fluorinated surface modifiers (BFSMs) with a base polyurethane material. By coupling RGD peptides to the fluorinated surface modifiers to form RGD‐BFSMs, the BFSMs can act as a vehicle for the delivery of RGD moieties to the surface without direct covalent attachment to the polymer substrate. Fluorescent RGD‐BFSMs were shown to migrate to the polymer–air interfaces within the porous scaffolds by two‐photon confocal microscopy. A‐10 rat aortic smooth muscle cells were cultured for 4 weeks on nonmodified and RGD‐BFSM‐modified porous scaffolds, and cell adhesion, proliferation, and viability were quantified at different depths. RGD‐BFSM‐modified scaffolds showed significantly greater cell numbers within deeper regions of the scaffolds, and this difference became more pronounced over time. This study demonstrates an effective approach to promote cell adhesion and infiltration within thick (∼0.5 cm) porous synthetic scaffolds by providing a uniform distribution of adhesive peptide throughout the scaffolds without the use of covalent surface reaction chemistry. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.
Tailoring the degradation kinetics of mesoporous silicon structures through PEGylation
Authors: Godin Biana , Gu Jianhua , Serda Rita E. , Bhavane Rohan , Tasciotti Ennio , Chiappini Ciro , Liu Xuewu , Tanaka Takemi , Decuzzi Paolo , Ferrari Mauro 
Published: April 2010

AbstractInjectable and implantable porosified silicon (pSi) carriers and devices for prolonged and controlled delivery of biotherapeutics offer great promise for treatment of various chronic ailments and acute conditions. Polyethylene glycols (PEGs) are important surface modifiers currently used in clinic mostly to avoid uptake of particulates by reticulo‐endothelial system (RES). In this work we show for the first time that covalent attachment of PEGs to the pSi surface can be used as a means to tune degradation kinetics of silicon structures. Seven PEGs with varying molecular weights (245, 333, 509, 686, 1214, 3400, and 5000 Da) were employed and the degradation of PEGylated pSi hemispherical microparticles in simulated physiological conditions was monitored by means of ICP‐AES, SEM, and fluorimetry. Biocompatibility of the systems with human macrophages in vitro was also evaluated. The results clearly indicate that controlled PEGylation of silicon microparticles can offer a sensitive tool to finely tune their degradation kinetics and that the systems do not induce release of proinflammatory cytokines IL‐6 and IL‐8 in THP1 human macrophages. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010
The relationship of polyethylene wear to particle size, distribution, and number: A possible factor explaining the risk of osteolysis after hip arthroplasty
Authors: Gallo Jiri , Slouf Miroslav , Goodman Stuart B. 
Published: April 2010

AbstractThe most critical factor in the development of periprosthetic osteolysis (OL) in total hip arthroplasty (THA) is the biological reaction to wear debris. This reaction is dependent, in part, on the size and concentration of particles, which are determined predominantly by the polyethylene (PE) wear rate. This implies that the risk for developing OL and prosthesis failure can be estimated from wear measurements. We developed a computational algorithm for calculating the total number of PE particles for volumetric wear when particle size and distribution are known. We found that: (i) total number of PE wear particles decreases up to 5 orders of magnitude if the average size of particles increases and the total volumetric wear remains constant; (ii) total amount of PE wear particles decreases up to 4 orders of magnitude if the width of the distribution increases and total volumetric wear remains constant; (iii) for the same volumetric wear, the number of particles significantly decreases/increases with the increase/decrease in their average size and range. These findings suggest that the risk for the development of OL in THA cannot be simply estimated from the volumetric wear alone. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010.
Fracture healing in mice under controlled rigid and flexible conditions using an adjustable external fixator
Authors: Röntgen Viktoria , Blakytny Robert , Matthys Romano , Landauer Mario , Wehner Tim , Göckelmann Melanie , Jermendy Philipp , Amling Michael , Schinke Thorsten , Claes Lutz , Ignatius Anita 
Published: April 2010

AbstractMice are increasingly used to investigate mechanobiology in fracture healing. The need exists for standardized models allowing for adjustment of the mechanical conditions in the fracture gap. We introduced such a model using rigid and flexible external fixators with considerably different stiffness (axial stiffnesses of 18.1 and 0.82 N/mm, respectively). Both fixators were used to stabilize a 0.5 mm osteotomy gap in the femur of C57BL/6 mice (each n = 8). Three‐point bending tests, µCT, and histomorphometry demonstrated a different healing pattern after 21 days. Both fixations induced callus formation with a mixture of intramembranous and enchondral ossification. Under flexible conditions, the bending stiffness of the callus was significantly reduced, and a larger but qualitatively inferior callus with a significantly lower fraction of bone but a higher fraction of cartilage and soft tissue was formed. Monitoring of the animal movement and the ground reaction forces demonstrated physiological loading with no significant differences between the groups, suggesting that the differences in healing were not based on a different loading behavior. In summary, flexible external fracture fixation of the mouse femur led to delayed fracture healing in comparison to a more rigid situation. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1456–1462, 2010
Platelet‐rich plasma on calcium phosphate granules promotes metaphyseal bone healing in mini‐pigs
Authors: Jungbluth Pascal , Wild Michael , Grassmann Jan‐Peter , Ar Ebru , Sager Martin , Herten Monika , Jäger Marcus , Becker Juergen , Windolf Joachim , Hakimi Mohssen 
Published: April 2010

AbstractThe role of platelet‐rich plasma (PRP) as a promoter of bone healing remains controversial. The aim of this study was to investigate the effect of PRP in combination with calcium phosphate granules (CPG) on bone defect healing in a metaphyseal long bone defect. A metaphyseal bone defect at the proximal tibia of 16 mini‐pigs was filled with CPG combined with autologous PRP or CPG solely (control group). The PRP showed 4.4‐fold more platelets compared to peripheral blood. Six weeks after surgery the radiological and histomorphometrical evaluations showed significantly more bone formation in the PRP group in the central area of the defect zone (p < 0.01) as well as the cortical defect zone (p < 0.04). Furthermore, the resorption rate of CPG was increased in animals who received PRP. Nevertheless there were only isolated instances of complete osseous bridging of the bone defects even in the PRP group. This study demonstrates that a PRP‐CPG composit promotes bone regeneration but does not lead to a solid fusion of a tibial defect in mini‐pigs. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1448–1455, 2010
Prostaglandin E2 and prostaglandin F2α differentially modulate matrix metabolism of human nucleus pulposus cells
Authors: Vo Nam V. , Sowa Gwendolyn A. , Kang James D. , Seidel Christopher , Studer Rebecca K. 
Published: April 2010

AbstractProstaglandin (PG) actions on disc metabolism are unclear even though certain PGs are highly expressed by disc cells under inflammatory conditions and nonsteroidal anti‐inflammatory drugs (NSAIDs) are frequently used to block PG production to treat back pain. Hence this study aimed to (1) quantify gene expression of arachidonic acid cascade components responsible for PG synthesis and (2) examine the effects of key PGs on disc matrix homeostasis. Microarray analysis revealed that inflammatory stress increases expression of synthases and receptors for prostaglandin E2 (PGE2) and prostaglandin F2α (PGF2α), resulting in elevated PGE2 and PGF2α production in conditioned media of disc cells. PGE2 diminished disc cell proteoglycan synthesis, in a dose‐dependent manner. Semiquantitative RT‐PCR revealed differential effects of PGE2 and PGF2α on disc cell expression of key matrix structural genes, aggrecan, versican, collagens type I and II. PGE2 and PGF2α also decreased message for the anabolic factor, IGF‐1. PGE2 decreased mRNA expression for the anti‐catabolic factor TIMP‐1 while PGF2α increased mRNAs for catabolic factors MMP‐1 and MMP‐3. Thus, PGE2 and PGF2α may have an overall negative impact on disc matrix homeostasis, and the use of NSAIDs may impact disc metabolism as well as treat back pain. Published by Wiley Periodicals, Inc. J Orthop Res 28:1259–1266, 2010
Efficacy of moxifloxacin compared to teicoplanin in the treatment of implant‐related chronic osteomyelitis in rats
Authors: Ozturan Kutay Engin , Yucel Istemi , Kocoglu Esra , Cakici Husamettin , Guven Melih 
Published: April 2010

AbstractTreatment of implant‐related chronic osteomyelitis is often difficult and usually consists of implant removal, extensive surgical debridement, and prolonged antibiotic use. This study was performed to assess the efficacy of moxifloxacin compared to a glycopeptide, teicoplanin in chronic implant‐related methicillin‐sensitive Staphylococcus aureus (MSSA) osteomyelitis. The left femoral medullar cavities of 60 Wistar male rats were contaminated with 100 µl of 108 cfu/ml methicillin‐sensitive S. aureus (ATCC 29213) and Kirschner wires were placed into the medulla of the femur. After 6 weeks, rats were randomly divided into five groups. In two groups, the Kirschner wires were removed. Experimental groups were as follows: group 1: contaminated, Kirschner wire inside, received teicoplanin; group 2: contaminated, Kirschner wire removed, received teicoplanin; group 3: contaminated, Kirschner wire inside, received moxifloxacin; group 4: contaminated, Kirschner wire removed, received moxifloxacin; group 5: contaminated, Kirschner wire inside, no antibiotics (control group). Groups 1 and 2 received teicoplanin (20 mg/kg once daily), whereas groups 3 and 4 received moxifloxacin (10 mg/kg twice daily) intraperitoneally for 28 days. At the end of the treatment, animals were sacrificed by inhalation anesthesia with ether and femora were retrieved and bacterial counts (cfu/g) were determined. Bacterial counts in all study groups were significantly reduced relative to the control. The decrease of bacterial counts was more prominent in group 4 compared to group 1 (p = 0.001) and group 2 (p = 0.003). Moxifloxacin therapy is an effective alternative to teicoplanin for chronic implant‐related MSSA osteomyelitis. Published by Wiley Periodicals, Inc. J Orthop Res 28:1368–1372, 2010
Raman and IR spectra of K4Nb6O17and K4Nb6O17·3H2O single crystals
Authors: Ma̧czka M. , Ptak M. , Majchrowski A. , Hanuza J. 
Published: April 2010

AbstractPolarised Raman and IR spectra of K4Nb6O17 and K4Nb6O17· 3H2O single crystals were measured. The obtained spectra are discussed using the factor group approach for the orthorhombic P21nb space group and assignment of bands to the respective motions of atoms is proposed. In particular, we have shown that the bands above 770 cm−1 can be attributed to the stretching modes of short niobium–oxygen bonds, which are present in this material due to the pronounced layered structure, whereas the potassium atoms contribute to the bands observed below 180 cm−1. Our studies have revealed that intercalation of water molecules leads to shifts, broadening and changes in intensity of some bands. These changes have been attributed to slight changes in the bond lengths and angles, interactions of the water molecules with K atoms and structural disorder introduced by the intercalated water molecules. However, the main structural framework was preserved. Copyright © 2010 John Wiley & Sons, Ltd.
Perceived benefits and barriers to joint protection among people with rheumatoid arthritis and occupational therapists. A mixed methods study
Authors: Niedermann K. , Hammond A. , Forster A. , de Bie R. 
Published: April 2010

AbstractBackground: Deciding whether or not to perform a health behaviour is an active decision‐making process which has an impact on current and future behaviour and can be influenced by the beliefs both of patients and their healthcare professionals. The aim of this study was to explore rheumatoid arthritis (RA) patients' and occupational therapists' (OTs) perceptions of the benefits of and barriers to performing joint protection (JP).Methods: A mixed methods design was used. Questionnaires applied a theoretical framework of key themes to assess the relevance of JP benefits and barriers both to people with RA and OTs. Focused interviews with people with RA then enabled data triangulation. Investigator triangulation was used to check the validity of data interpretation.Findings: Ten people with RA and nine OTs participated. From the questionnaires, both groups agreed that highly relevant key themes for JP benefits were physical well‐being, potential benefit and personal control. By contrast, the three key themes for JP barriers – negative attitude of others, negative impact on others and taking time from other things – were relevant for the majority of the OTs but not patients. The interviews enabled an understanding of the meaning behind RA patients' ratings, particularly their differences from OTs. People with RA explained JP benefits, and disease acceptance had altered some initial barriers into perceived benefits over time.Conclusions: Emphasizing benefits and identifying individually relevant barriers could be an important communication strategy for OTs in understanding patients' rationale for whether or not to adopt JP methods. Copyright © 2010 John Wiley & Sons, Ltd.
Der Lotus‐Effekt: Selbstreinigung mikrostrukturierter Oberflächen
Authors: Fürstner Reiner , Neinhuis Christoph , Barthlott Wilhelm 
Published: April 2010

AbstractDie Lotusblume gilt in den asiatischen Religionen als Symbol der Reinheit: Makellos sauber entfalten sich ihre Blätter aus schlammigen Gewässern. Untersuchungen dieses Phänomens zeigten, wie sich Pflanzen gegen Schmutz und Keime schützen. Anhand dieser Kenntnisse können nun künstliche, biomimetische Oberflächen mit ähnlichen Eigenschaften entwickelt werden.
Der Natur auf der Spur
Authors: Michael Katja 
Published: April 2010

AbstractEs ist das enorme Potential für den Fortschritt in nahezu allen naturwissenschaftlichen Disziplinen, das Bioorganiker dazu inspiriert, Biopolymere, ihre monomeren Bausteine und Naturstoffe auf molekularer Ebene zu erforschen und sich zunutze zu machen Wie vielfältig die Forschung ist, zeigt alljährlich das Nachwuchswissenschaftlersymposium „Bioorganische Chemie”︁.
Gibt es ehrliche Preise für die Umweltbelastung?
Authors: Schoenberg Dieter 
Published: April 2010

AbstractEs kann, so sagt Andreas Troge, der Präsident des Umweltbundesamtes, durch die politisch‐ökonomischen Entscheidungssysteme nicht gelingen, Umweltschäden real in Mark und Pfennig zu bewerten. Es fehlen die wissenschaftlichen Grundlagen, um ökologisch richtige Preise zu ermitteln.
E‐Commerce in der Chemie ‐Fußnote oder Strukturbruch?
Authors: Jung Udo , Willers Yves P. 
Published: April 2010

AbstractAlle Unternehmen ‐ auch in der chemischen Industrie ‐stehen vor der Aufgabe, die durch das Internet hervorgerufene Informationsrevolution aktiv zu nutzen und für die eigene Geschäftsstrategie und die damit verbundenen Geschäftsprozesse zu konkretisieren. Auch in der Chemie ist ein radikaler Strukturbruch absehbar.
Raising awareness about fecal incontinence
Authors: Bliss Donna Z. , Norton Christine , Vodusek David B. 
Published: April 2010

AbstractThere is a lack of awareness about fecal incontinence despite its prevalence and adverse impact on quality of life. Inadequate knowledge about fecal incontinence deters help‐seeking, therapeutic consultation, and clinical research about effective prevention and management strategies. A systematic, evidenced‐based approach to raise awareness of fecal incontinence is essential to forward progress and overcome multiple barriers. In this manuscript, strategies of this approach are prioritized and focus on increasing continence literacy and communication, emphasizing prevention and screening, disseminating evidenced‐based management interventions, and promoting larger scale impact through effective partnerships. Neurourol. Urodynam. 29:612–615, 2010. Copyright © 2010 Wiley‐Liss, Inc.
Genetics and the lower urinary tract
Authors: Norton Peggy , Milsom Ian 
Published: April 2010

AbstractMany complex disorders have been found to have a heritable component, including lower urinary tract dysfunction. Twin studies have indicated that genetic contributions to urinary incontinence (UI) may be as important as environmental influences. Linkage to chromosome 9 has been demonstrated in families with pelvic organ prolapse and stress UI. An increasing number of incontinence specialists are studying subjects with lower urinary tract dysfunction using single nucleotide polymorphisms, linkage analyses of siblings, and large association studies. These findings have exciting implications for future prevention and treatment of UI. Neurourol. Urodynam. 29:609–611, 2010. © 2010 Wiley‐Liss, Inc.
Crystallization and morphology of polymerized cyclic butylene terephthalate
Authors: Wu Chang‐Mou , Jiang Chi‐Wea 
Published: April 2010

AbstractThe crystallization behavior and morphology of polymerized cyclic butylene terephthalate (pCBT) were investigated by thermal differential scanning calorimetry (DSC) and polarized light microscopy (PLM). The spherulite growth rate was analyzed based on the Hoffman and Lauritzen theory to better understand the crystallization behavior. We found four typical morphologic features of pCBT corresponding to the crystallization temperature spectrum: usual negative spherulite, unusual spherulite, mixed birefringence spherulite coexisting with boundary crystals, and highly disordered spherulitic crystallites. The Avrami crystallization kinetics confirmed the occurrence of combined heterogeneous nucleation accompanied by a change in the spherulitic shape of pCBT, which also agreed with the PLM results. The equilibrium melting temperature and glass transition temperature of pCBT were 257.8 °C and 41.1 °C, respectively. A regime II–III transition occurred at 200.9 °C, which was 10 °C lower than that reported for poly(butylene terephthalate) (PBT). Coinciding with and attributed to the regime transition, the boundary crystal disappeared at temperatures above 200 °C and the morphology changed from the mixed type to highly disordered spherulitic crystallites. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1127–1134, 2010
Nanostructured polybenzoxazine thermosets via reaction‐induced microphase separation
Authors: Li Yan , Zheng Sixun 
Published: April 2010

AbstractA multiblock copolymer consisting of main‐chain polybenzoxazine and poly(propylene oxide) blocks was synthesized via Mannich polycondensation among 4,4′‐dihydroxyldiphenylisopropane, 4,4′‐diaminodiphenylmethane, amino‐terminated poly(propylene oxide), and paraformaldehyde, which was evidenced by Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and gel permeation chromatography. The multiblock copolymer was incorporated into polybenzoxazine to access the nanostructured polybenzoxazine thermosets. The morphology of the thermosets was investigated by means of atomic force microscopy and small angle X‐ray scattering. It was judged that the formation of the nanostructures in the thermosetting composites follows the mechanism of reaction‐induced microphase separation. Owing to the big difference in thermal stability between polybenzoxazine thermosets and poly(propylene oxide), the nanostructured thermosets were subjected to the pyrolysis at moderate elevated temperatures to remove poly(propylene oxide) microdomains, to access the nanoporous polybenzoxazine thermosets. The nanoporosity of the resulting polybenzoxazine thermosets was investigated by means of Fourier transform infrared spectroscopy and field‐emission scanning electronic microscopy. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1148–1159, 2010
Morphological evolution and orientation development of stretched iPP films: Influence of draw ratio
Authors: Zhou Ying‐Guo , Turng Lih‐Sheng , Shen Chang‐Yu 
Published: April 2010

AbstractVarying the processing conditions of semicrystalline polymers can produce different morphologies of crystallization, which leads to different properties. There have been extensive studies of flow‐induced crystallization on isotactic polypropylene (iPP) using predominantly shear flow. A stretching method, deduced from extrusion, was introduced to study the morphological evolution of elongation‐induced shish‐kebab crystallization. Different morphologies of the resultant samples with different draw ratios (DRs) were carefully investigated and characterized via differential scanning calorimetry, polarizing light microscopy, scanning electron microscopy, atomic force microscopy, and 2D small‐angle X‐ray scattering. In addition, the degree of orientation of the samples with different DRs was also investigated using the 2D wide‐angle X‐ray scattering technique. The results indicate that the elongation‐induced morphology is strongly dependent on the effective stretching flow expressed in terms of the DR, which is defined as the ratio of rates between take‐up and the extrusion. The spherulite is dominant at low DRs, but it starts to deform along the stretching direction with increasing DR. The shish‐kebab structure in the stretched film, composed of stretched chains (shish) and layered crystalline lamellae (kebabs), increases gradually with an increase in the DR, whereas the spherulites gradually decreased. Furthermore, the overall orientation of α‐phase crystals, expressed by the Hermans orientation parameter, is also found to increase dramatically with the DR, and the rate of increase strongly depends on the DR. The different crystal morphologies are attributed to crystallization induced by different elongations of the stretched iPP films. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1223–1234, 2010