bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bone repair and regeneration: possibilities
Authors: Vallet‐Regí M. 
Published: June 2006

AbstractThe most significant demand for biomaterials has emerged as a consequence of the need to provide clinical treatment to a large number of patients. The key factors and driving forces are the increase in life expectancy and the aim to provide a minimum quality of life to an aging population. In particular, said increase in life expectancy has increased considerably the number of patients with osteoporosis. If we take also into account the continuous increase in the number of motor vehicles, with its associated social penalty in terms of traffic accidents, the incidence of bone pathologies is increasing at an alarming rate in recent years. The search for potential solutions in this field produces a large demand for materials suitable for bone repair or replacement. Calcium phosphates, bio‐glasses, bio‐glass ceramics and ordered silica mesoporous materials, among other types of materials, will be reviewed and studied from the point of view of their potential applications as replacement materials in bone repair and regeneration, as potential substrates in tissue engineering, and also as drug delivery systems. The ability of functionalising the material surfaces with various molecules of different nature and shape will allow to actuate selectively on the biological environment. An overview on the present achievements, but also on the ‘missing links’ will be presented.
Study on the influence of plasma spray processes and spray parameters on the structure and crystallinity of hydroxylapatite coatings
Authors: Zhao L. , Bobzin K. , Ernst F. , Zwick J. , Lugscheider E. 
Published: June 2006

AbstractHydroxylapatite (HA) is one of the most important materials for human hard tissue implants. Until now, HA coatings are widely deposited on implants using atmospheric plasma spraying (APS). Due to the decomposition of HA and formation of amorphous phase during spraying, the crystallinity of APS coatings is usually below 70 %, although coarser spray powders such as one with a size distribution of –150 +45 μm are used. In this study a finer HA powder –80 +50 μm was sprayed using both a conventional APS process and the new “microplasma spraying” (MPS) process. The coatings were characterized in terms of their microstructure and crystallinity. It was found that the spray parameters influenced strongly the coating structure and phase composition. Despite the smaller particles, the HA content of APS coatings could be increased from 27 % to 72 % only by changing the spray parameters. Higher HA contents up to over 85 % could be obtained by microplasma spraying. It was found that textured coatings could form under certain conditions during both spray processes.
X‐ray powder diffraction data of synthetic β‐Tricalcium Phosphate
Authors: Ermrich M. , Peters F. 
Published: June 2006

AbstractThe production of synthetic Tricalcium Phosphate (β‐TCP, Ca3(PO4)2) allows to exclude all disadvantages of biological based ceramics. Moreover the sintered pure‐phase material ensures a high reproducibility without any organic residues or foreign matters. The material was characterized by X‐ray powder diffraction. Using the well‐known structure, the trigonal cell parameters were refined using the information of the Powder Diffraction File PDF #9‐169 to ([1], space group R‐3c, #167, hexagonal setting) : a = b = 10.4183(5) Å, c = 37.346(2) Å, γ = 120°, V = 3510.5(5) Å3; Z = 21, Dx = 3.081 g/cm3. These values represent the lowest lattice parameters for this structure, because of its lowest possible Mg‐ content.
Bioceramic Granulates for use in 3D Printing: Process Engineering Aspects
Authors: Irsen St. H. , Leukers B. , Höckling Chr. , Tille C. , Seitz H. 
Published: June 2006

AbstractFor the fabrication of patient individual bone replacement scaffolds using rapid prototyping (RP) technology, materials with properties adapted to the 3D printing process are needed. First of all the granulate properties of the building material have to match certain specifications concerning particle size and morphology. To fulfil these demands in laboratory scale a commercial fluidized bed granulator was modified to match the specific needs. The changes were tested spraying a sample granulate for the fabrication of synthetic bone grafts. This granulate could successfully be processed in the 3D printer.
A porous media model describing the inhomogeneous behaviour of the human intervertebral disc
Authors: Ehlers W. , Karajan N. , Markert B. 
Published: June 2006

AbstractDue to the remarkable number of patients suffering from low back pain, a higher research interest is initiated regarding modern numerical simulation techniques. Herein, the Finite Element Method (FEM) in combination with an elaborated model has the potential to be the best choice aiding the design of new intervertebral disc (IVD) implants.As one of the most vulnerable parts of the human spine, the (IVD) belongs to the class of soft avascular cartilaginous tissues consisting of mostly ionized water (interstitial fluid) and collagen of type I and II embedded in an extracellular meshwork of charged protein compounds. More precisely, the type I collagen is organized in fiber bundles building a fiber‐reinforced ring, the anulus fibrosus (AF), which encloses a highly charged gelatinous core, the nucleus pulposus (NP).The purpose of this contribution is to utilize the established Theory of Porous Media (TPM) as a continuum‐mechanical framework for the modelling of the IVD. In this context, the TPM is perfectly suitable for the description of multi‐component continua with internal interactions and is proven to yield stable implementations within the mixed Finite Element Method (FEM). Following this, one succeeds in describing the electro‐chemomechanical couplings between the constituents as well as the viscoelastic and anisotropic properties of the extracellular matrix. Moreover, the fiber vectors, which represent the aligned collagen in a continuum‐mechanical sense, as well as the location‐dependent material parameters must be inhomogeneously distributed over the discretized IVD.
Biomaterial structure in deep‐sea bamboo coral (Anthozoa: Gorgonacea: Isididae): perspectives for the development of bone implants and templates for tissue engineering
Authors: Ehrlich H. , Etnoyer P. , Litvinov S. D. , Olennikova M.M. , Domaschke H. , Hanke T. , Born R. , Meissner H. , Worch H. 
Published: June 2006

AbstractNatural structural biomaterials of marine origin including mollusc shells, sponges and corals not only provide an abundant source of novel bone and cartilage replacements but also inspire investigations to develop nano‐sized biomimetic composites. This study presents a characterisation of the ultrastructure of the deep‐sea Bamboo coral (Anthozoa: Gorgonacea: Isididae) and the nanostructure of some interstitial surfaces with respect to biomineralization phenomena. The skeletons of the corals examined exhibit jointed axes of large bony calcareous structures alternated with smaller proteinaceous nodes of gorgonin, giving the skeletal remains of the organism a digitated appearance, like terrestrial bamboo. To test the hypothesis that bamboo coral internodes exhibit bone‐like mechanical and biochemical properties, structural and biochemical analyses of these natural biomineral composites and separation of proteinaceous components was performed. Due to its high potential for colonization with both human osteoblasts and osteoclasts, the organic matrix, composed of an acidic fibrillar protein framework, proved to be a very successful model for possible applications in tissue engineering. The material properties of the calcareous internodes correlate well with the material property charts for materials used in orthopedic surgery, though denser and stronger than bone. Results of the present study also clearly indicate the quinonproteinaceous nature of the gorgonin. On the basis of the high biomimetic potential of the results obtained, the use of Isididae corals as “living bone implants” as well as their biotechnological aquacultural cultivation seems to be promising for the near future.
Trout Ea4‐ or human Eb‐peptide of pro‐IGF‐I disrupts heart, red blood cell, and vasculature development in zebrafish embryos
Authors: Chun Chang Zoon , Tsai H.J. , Chen Thomas T. 
Published: June 2006

AbstractE‐peptide of the pro‐insulin‐like growth factor (pro‐IGF)‐I is produced by proteolytic cleavage of the pro‐hormone in post‐translational processing. Introduction of a transgene encoding a secreted form of rtEa4‐ or hEb‐peptide into newly fertilized zebrafish (Danio rerio) eggs by electroporation or microinjection resulted in embryos with abnormal cardiovascular features and reduced red blood cells and vasculature. Two different phenocopies of heart developmental defects were observed: (i) Group I embryos exhibited heart development arrested at the heart muscle stage and (ii) group II embryos exhibited heart development arrested at the heart tube stage. Both groups of embryos also exhibited reduction of red blood cells and vasculature. The mRNA levels of genes essential for heart development (GATA 5 and NKX2.5), hematopoiesis (GATA 1 and GATA 2), and vasculogenesis (VEGF) in normal and defective embryos were determined by quantitative real‐time RT‐PCR at 36 hr post‐fertilization (hpf). Significant reduction of GATA 5, NKX2.5, GATA 1, GATA 2, and VEGF mRNA levels was observed in both groups of defective embryos. These results suggest that overexpression of rtEa4 or hEb transgene in zebrafish embryos disrupts heart development, hematopoiesis, and vasculogenesis by reducing the levels of GATA 5, NKX2.5, GATA 1, GATA 2, and VEGF mRNA. Mol. Reprod. Dev. 1112–1121, 2006. © 2006 Wiley‐Liss, Inc.
Microglia and inflammation: Impact on developmental brain injuries
Authors: Chew Li‐Jin , Takanohashi Asako , Bell Michael 
Published: June 2006

AbstractInflammation during the perinatal period has become a recognized risk factor for developmental brain injuries over the past decade or more. To fully understand the relationship between inflammation and brain development, a comprehensive knowledge about the immune system within the brain is essential. Microglia are resident immune cells within the central nervous system and play a critical role in the development of an inflammatory response within the brain. Microglia are critically involved with both the innate and adaptive immune system, regulating inflammation and cell damage within the brain via activation of Toll‐like receptors, production of cytokines, and a myriad of other intracellular and intercellular processes. In this article, microglial physiology is reviewed along with the role of microglia in developmental brain injuries in humans and animal models. Last, microglial functions within the innate and adaptive immune system will be summarized. Understanding the processes of inflammation and microglial activation is critical for formulating effective preventative and therapeutic strategies for developmental brain injuries. MRDD Research Reviews 2006;12:105–112. © 2006 Wiley‐Liss, Inc.
Vanishing white matter disease: A review with focus on its genetics
Authors: Pronk Jan C. , van Kollenburg Barbara , Scheper Gert C. , van der Knaap Marjo S. 
Published: June 2006

AbstractLeukoencephalopathy with vanishing white matter (VWM) is an autosomal recessive brain disorder, most often with a childhood onset. Magnetic resonance imaging and spectroscopy indicate that, with time, increasing amounts of cerebral white matter vanish and are replaced by fluid. Autopsy confirms white matter rarefaction and cystic degeneration. The process of localization and identification of the first two genes related to VWM, EIF2B5 and EIF2B2, was facilitated by two founder effects in the Dutch population. EIF2B5 and EIF2B2 encode the ε and β subunits of translation initiation factor eIF2B. Soon it was shown that mutations in all five eIF2B subunit genes can cause VWM. EIF2B is essential for the initiation of translation of RNA into protein and is involved in regulation of the process, especially under stress conditions, which may explain the sensitivity to stress conditions observed in VWM patients. The pathophysiology of the disease is still poorly understood. MRDD Research Reviews 2006;12:123–128. © 2006 Wiley‐Liss, Inc.
Childhood multiple sclerosis: A review
Authors: Waldman Amy , O'Connor Erin , Tennekoon Gihan 
Published: June 2006

AbstractMultiple sclerosis (MS) is an autoimmune demyelinating disorder of the central nervous system (CNS) that is increasingly recognized as a disease that affects children. Similar to adult‐onset MS, children present with visual and sensory complaints, as well as weakness, spasticity, and ataxia. A lumbar puncture can be helpful in diagnosing MS when CSF immunoglobulins and oligoclonal bands are present. White matter demyelinating lesions on MRI are required for the diagnosis; however, children typically have fewer lesions than adults. Many criteria have been proposed to diagnose MS that have been applied to children, mostly above 10 years of age. The recent revisions to the McDonald criteria allow for earlier diagnosis, such as after a clinically isolated event. However, children are more likely than adults to have monosymptomatic illnesses. None of the approved disease‐modifying therapies used in adult‐onset MS have been approved for pediatrics; however, a few studies have verified their safety and tolerability in children. Although children and adults with MS have similar neurological symptoms, laboratory (cerebrospinal fluid) data, and neuroimaging findings, the clinical course, pathogenesis, and treatment of childhood onset MS require further investigation. MRDD Research Reviews 2006;12:147–156. © 2006 Wiley‐Liss, Inc.
Repetitive cycles of high‐dose cytarabine are effective for childhood acute myeloid leukemia: Long‐term outcome of the children with AML treated on two consecutive trials of Tokyo Children's Cancer Study Group
Authors: Tomizawa Daisuke , Tabuchi Ken , Kinoshita Akitoshi , Hanada Ryoji , Kigasawa Hisato , Tsukimoto Ichiro , Tsuchida Masahiro 
Published: June 2006

AbstractBackgroundVarious methods of intensive chemotherapy have contributed to an improved survival in pediatric acute myeloid leukemia (AML). We here report the long‐term results of the two consecutive trials of Tokyo Children's Cancer Study Group (TCCSG), incorporating repetitive use of high‐dose cytarabine (HD‐Ara‐C) based combination chemotherapy in post‐remission phase.ProcedureA total of 216 eligible children with newly diagnosed AML were treated in the two consecutive multi‐center trials of TCCSG, M91‐13 and M96‐14, from August 1991 to September 1998. In M91‐13 trial, patients received eight courses of intensive post‐remission chemotherapy, including six HD‐Ara‐C containing courses, after remission‐induction therapy. Autologous hematopoietic stem cell transplantation (HSCT) could be selected by physician's choice, and allogeneic HSCT was allocated if donor was available. In M96‐14 trial, the last two HD‐Ara‐C courses were omitted from the chemotherapy arm.ResultsThe remission‐induction rate was 88.8% and probability of 5‐year Overall survival (OS) and event‐free survival (EFS) were 62% (56–69% with 95% Confidence intervals (CIs)) and 56% (49–62%), respectively. Treatment‐related mortality (TRM) was 7.8%. Among patients without Down syndrome (DS) or acute promyelocytic leukemia (APL), the presence of t(8;21) or inv(16) was a significant good prognostic factor both in the univariate and multivariate analyses. Children with DS (N = 10) and APL (N = 14) also showed a good survival exceeding 70% in 5 years.ConclusionsThese results suggest that repetitive use of HD‐Ara‐C was effective and safe for childhood AML. However, further optimization of AML therapy is required. Pediatr Blood Cancer 2007;49:127–132. © 2006 Wiley‐Liss, Inc.
Frequent lancing for monitoring blood glucose may cause skin changes
Authors: Fruhstorfer H 
Published: June 2006

AbstractFingertips and alternative lancing sites were examined for skin changes in 93 people with diabetes, regularly checking blood glucose. In all, 60 individuals had a thickened skin at one or more lancing spots. Mainly fingertips and earlobes were affected whereas the thenar and hypothenar were free from these changes. There is a clear positive relationship between lancing frequency and skin changes which is possibly influenced by individual disposition. The observed relationship suggests the way in which to avoid skin changes: as many lancing spots as possible should be alternately used, avoiding lancing a given spot more often than once every other day. Copyright © 2006 John Wiley & Sons, Ltd.
A dietitian‐led lipid clinic is effective
Authors: Worth JM , Davies RR , Durrington PN 
Published: June 2006

AbstractThis study aimed to determine the effectiveness of a dietitian‐led, protocol‐driven Diabetes Centre lipid clinic in which the dietitian is empowered to give advice on both lifestyle and lipid‐lowering medication.A total of 110 consecutive patients with type 1 and type 2 diabetes attending the clinic received diet and lifestyle advice in conjunction with statin monotherapy or combined statin and fibrate therapy titrated with the aim of achieving target lipid levels. At the time, therapeutic targets were: total cholesterol <5.0mmol/L, LDL cholesterol <2.5mmol/L or a reduction in LDL cholesterol of 30% (whichever was lower) and triglycerides <2.3mmol/L.Results following three clinic visits indicated that total cholesterol fell significantly from 6.23 (6.08, 6.39) (mean [95% CI]) to 4.38 (4.30, 4.46) mmol/L (p<0.001) and triglycerides from 3.03 (2.59, 3.47) to 2.08 (1.87, 2.29) mmol/L (p<0.001). HDL rose slightly, but non‐significantly, from 1.21 (1.15, 1.27) to 1.23 (1.17, 1.29) mmol/L. These levels were maintained after 12 months of follow up. In all, 74% of patients had achieved lipid levels within the target range after three clinic visits. No patients experienced serious adverse events from the drug therapy.This study demonstrates that dietetic management of dyslipidaemia using a stepwise approach is both safe and effective in diabetic patients without major complications. Copyright © 2006 John Wiley & Sons, Ltd.
Thin film solar modules: the low cost, high throughput and versatile alternative to Si wafers
Authors: Hegedus S. 
Published: June 2006

AbstractThin film solar cells (TFSC) have passed adolescence and are ready to make a substantial contribution to the world's electricity generation. They can have advantages over c‐Si solar modules in ease of large area, lower cost manufacturing and in several types of applications. Factors which limit TFSC module performance relative to champion cell performance are discussed along with the importance of increased throughput and yield. The consensus of several studies is that all TFSC can achieve costs below 1 $/W if manufactured at sufficiently large scale >100 MW using parallel lines of cloned equipment with high material utilization and spray‐on encapsulants. There is significant new commercial interest in TFSC from small investors and large corporations, validating the thin film approach. Unique characteristics are discussed which give TFSC an advantage over c‐Si in two specific markets: small rural solar home systems and building integrated photovoltaic installations. TFSC have outperformed c‐Si in annual energy production (kWhrs/kW), have demonstrated outdoor durability comparable to c‐Si and are being used in MW scale installations worldwide. The merits of the thin film approach cannot be judged on the basis of efficiency alone but must also account for module performance and potential for low cost. TFSC advocates should promote their unique virtues compared to c‐Si: lower cost, higher kWhr/kW output, higher battery charging current, attractive visual appearance, flexible substrates, long‐term stability comparable to c‐Si, and multiple pathways for deposition with room for innovation and evolutionary improvement. There is a huge market for TFSC even at today's efficiency if costs can be reduced. A brief window of opportunity exists for TFSC over the next few years due the Si shortage. The demonstrated capabilities and advantages of TFSC must be proclaimed more persistently to funding decision‐makers and customers without minimizing the remaining challenges. Copyright © 2006 John Wiley & Sons, Ltd.
Photovoltaic concentration at the onset of its commercial deployment
Authors: Luque Antonio , Sala Gabriel , Luque‐Heredia Ignacio 
Published: June 2006

AbstractAn overview of the field of photovoltaic concentration is provided taking into account that we think we are at the onset of its real commercialization. This belief is justified in this paper. It first contains a description of the different elements in a concentrator, stressing the challenges associated with each element, and then we describe briefly the different concentrators that we think are currently in a real pre‐commercial stage. Finally, we discuss a number of issues associated to the deployment of the field including cost, experience, and market tendencies. This paper goes on to summarize the Conclusions. Copyright © 2006 John Wiley & Sons, Ltd.
Primary amine coding as a path to comparative proteomics
Authors: Regnier Fred E. , Julka Samir 
Published: June 2006

AbstractVarious isotope coding strategies are being used today in the field of comparative proteomics. This article specifically reviews the strengths and limitations of various N‐termini‐directing strategies. N‐termini‐directed coding strategy allows for use of different chromatographic enrichment techniques. Since N‐termini‐directed coding strategies are global in nature, they can be utilized in studying PTMs as well as protein expression. Using different N‐termini‐directed coding strategies, both relative and absolute quantification of proteins can be achieved either in the MS mode or in the MS/MS mode. The review ends with the conclusion that significant improvements have been made in the last decade. Among various issues, a need still exists for a better understanding of the kinetic issues in proteomics, relative protein pool sizes for different proteins and the issue of stimulus‐induced changes in protein aggregation. Another critical issue that needs to be addressed in great detail is the role of PTMs in regulation.
Tertiary amine catalyzed polymerizations of α‐amino acid N‐carboxyanhydrides: The role of cyclization
Authors: Kricheldorf Hans R. , Von Lossow Colin , Schwarz Gert 
Published: June 2006

AbstractSarcosine N‐carboxyanhydride, D,L‐alanine N‐carboxyanhydride, D,L‐phenylalanine N‐carboxyanhydride, and D,L‐leucine N‐carboxyanhydride were polymerized with pyridine or N‐ethyldiisopropylamine as the catalyst. With pyridine, cyclic oligo‐ and polypeptides were obtained in addition to water‐initiated or water‐terminated chains. The cyclopeptides were the main products in the case of sarcosine N‐carboxyanhydride and D,L‐phenylalanine N‐carboxyanhydride. The fraction of cycles was particularly high when N‐methylpyrrolidone was used as the reaction medium. These results suggested the existence of a pyridine‐catalyzed zwitterionic mechanism. However, cyclopeptides were also obtained with N‐ethyldiisopropylamine as the catalyst. In this case, N‐deprotonation of N‐carboxyanhydrides, followed by the formation of N‐acyl N‐carboxyanhydride chain ends, was the most likely initiation mechanism. Various chain‐growth mechanisms were examined. In the case of γ‐benzyl ester‐L‐glutamate N‐carboxyanhydride, side reactions such as the formation of pyroglutamoyl end groups were detected. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4680–4695, 2006