bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conjugation of extracellular matrix proteins to basal lamina analogs enhances keratinocyte attachment
Authors: Bush Katie A. , Downing Brett R. , Walsh Sarah E. , Pins George D. 
Published: September 2006

AbstractThe dermal–epidermal junction of skin contains extracellular matrix proteins that are involved in initiating and controlling keratinocyte signaling events such as attachment, proliferation, and terminal differentiation. To characterize the relationship between extracellular matrix proteins and keratinocyte attachment, a biomimetic design approach was used to precisely tailor the surface of basal lamina analogs with biochemistries that emulate the native biochemical composition found at the dermal–epidermal junction. A high‐throughput screening device was developed by our laboratory that allows for the simultaneous investigation of the conjugation of individual extracellular matrix proteins (e.g. collagen type I, collagen type IV, laminin, or fibronectin) as well as their effect on keratinocyte attachment, on the surface of an implantable collagen membrane. Fluorescence microscopy coupled with quantitative digital image analyses indicated that the extracellular matrix proteins adsorbed to the collagen‐GAG membranes in a dose‐dependent manner. To determine the relationship between extracellular matrix protein signaling cues and keratinocyte attachment, cells were seeded on protein‐conjugated collagen‐GAG membranes and a tetrazolium‐based colorimetric assay was used to quantify viable keratinocyte attachment. Our results indicate that keratinocyte attachment was significantly enhanced on the surfaces of collagen membranes that were conjugated with fibronectin and type IV collagen. These findings define a set of design parameters that will enhance keratinocyte binding efficiency on the surface of collagen membranes and ultimately improve the rate of epithelialization for dermal equivalents. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
In vitro degradation of biodegradable blending materials based on poly(p‐dioxanone) and poly(vinyl alcohol)‐graft‐poly(p‐dioxanone) with high molecular weights
Authors: Chen Si‐Chong , Wang Xiu‐Li , Wang Yu‐Zhong , Yang Ke‐Ke , Zhou Zhi‐Xuan , Wu Gang 
Published: September 2006

AbstractAmphiphilic biodegradable graft copolymer, poly(vinyl alcohol)‐graft‐poly(p‐dioxanone) (PVA‐g‐PPDO), was used to prepare a new biodegradable material by blending with poly(p‐dioxanone) (PPDO). The in vitro degradation properties of the copolymer and blends with different contents of PVA‐g‐PPDO were studied in phosphate buffer at 37°C. The degradation processes of the PVA‐g‐PPDO and its blends with the PPDO were monitored by weight loss, viscosimetry, water uptake, differential scanning calorimetry (DSC), and scanning electron microscopy. The results of inherent viscosity and weight loss reveal that the PVA‐g‐PPDO has a different in vitro degradation behavior from that of PPDO, and the introducing of copolymer into the blending system may enhance the degradability of PPDO when the contents of copolymer is higher than 5%. The change of the degree of crystallization (Dc) of copolymer and blends derived from the DSC also shows that the copolymer and blends have faster degradation rates than the neat PPDO during the testing period. A degradation mechanism of the blends was postulated based on the results of the weight retention, inherent viscosity measurement, and DSC. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Kitagawa‐Takahashi diagrams define the limiting conditions for cyclic fatigue failure in human dentin
Authors: Kruzic J.J. , Ritchie R.O. 
Published: September 2006

AbstractAs cyclic fatigue is considered to be a major cause of clinical tooth fractures, achieving a comprehensive understanding of the fatigue behavior of dentin is of importance. In this note, the fatigue behavior of human dentin is examined in the context of the Kitagawa‐Takahashi diagram to define the limiting conditions for fatigue failure. Specifically, this approach incorporates two limiting threshold criteria for fatigue: (i) a threshold stress for fatigue failure, specifically the smooth‐bar (unnotched) fatigue endurance strength, at small crack sizes and (ii) a threshold stress‐intensity range for fatigue‐crack growth at larger crack sizes. The approach provides a “bridge” between the traditional fatigue life and fracture mechanics based damage‐tolerant approaches to fatigue‐life estimation, and as such defines a “failure envelope” of applied stresses and flaw sizes where fatigue failure is likely in dentin This approach may also be applied to fatigue failure in human cortical bone (i.e. clinical “stress fractures”), which exhibits similar fatigue behavior characteristics, and in principle may aid clinicians in making quantitative evaluations of the risk of fractures in mineralized tissues. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Time‐dependent effects of fatty acids on skeletal muscle metabolism
Authors: Hirabara Sandro M. , Silveira Leornardo R. , Abdulkader Fernando , Carvalho Carla R.O. , Procopio Joaquim , Curi Rui 
Published: September 2006

AbstractIncreased plasma levels of free fatty acids (FFA) occur in states of insulin resistance such as type 2 diabetes mellitus, obesity, and metabolic syndrome. These high levels of plasma FFA seem to play an important role for the development of insulin resistance but the mechanisms involved are not known. We demonstrated that acute exposure to FFA (1 h) in rat incubated skeletal muscle leads to an increase in the insulin‐stimulated glycogen synthesis and glucose oxidation. In conditions of prolonged exposure to FFA, however, the insulin‐stimulated glucose uptake and metabolism is impaired in skeletal muscle. In this review, we discuss the differences between the effects of acute and prolonged exposure to FFA on skeletal muscle glucose metabolism and the possible mechanisms involved in the FFA‐induced insulin resistance. J. Cell. Physiol. 210: 7–15, 2007. © 2006 Wiley‐Liss, Inc.
AF6/s‐afadin is a dual residency protein and localizes to a novel subnuclear compartment
Authors: Buchert Michael , Poon Carole , King James A.J. , Baechi Thomas , D'Abaco Giovanna , Hollande Frédéric , Hovens Christopher M. 
Published: September 2006

AbstractThe AF6/afadin protein is a component of cell membranes at specialized sites of cell–cell contact. Two main splice variants exist, known as l‐ and s‐afadin, respectively. L‐afadin is widely expressed in cells of epithelial origin, whilst s‐afadin expression is restricted to the brain. Here we demonstrate that the short form of AF6/s‐afadin is a dual residency protein able to localize to the plasma membrane or nucleus whilst the long form of AF6, l‐afadin is unable to localize to the nucleus. AF6/s‐afadin clusters in a distinctive speckled pattern in the nucleus, but is unable to do so when cell cycle progression is inhibited at the G1/S or G2/M checkpoints. The formation of AF6/s‐afadin nuclear bodies is also sensitive to the transcriptional activity of the cell with inhibition of RNA polymerase activity abolishing AF6/s‐afadin nuclear clustering. AF6/s‐afadin nuclear bodies localize to a novel subnuclear compartment, failing to colocalize with other known nuclear bodies. Formation of the AF6/s‐afadin nuclear foci can be regulated by specific growth factor receptor mediated signaling events and by cytoplasmic tyrosine kinases, but does not correlate with tyrosine phosphorylation of AF6/s‐afadin. AF6/s‐afadin is a candidate for mediating control of cellular growth processes by regulated translocation to the nucleus. J. Cell. Physiol. 210: 212–223, 2007. © 2006 Wiley‐Liss, Inc.
Characterization of linear and cyclic polylactic acids and their solvolysis products by electrospray ionization mass spectrometry
Authors: Osaka Issey , Watanabe Mikio , Takama Masashi , Murakami Masahiro , Arakawa Ryuichi 
Published: September 2006

AbstractLinear and cyclic polylactic acids (PLAs) were characterized using electrospray ionization mass spectrometry (ESI‐MS) as part of our ongoing investigation of the hydrolysis mechanism of biodegradable polymers. The condensation oligomers of linear polylactic acid (LPLA) were synthesized by thermal dehydration of L‐lactic acid. The trimer and tetramer base polymers of cyclic polylactic acid (CPLA) were obtained by cyclization reactions of lactic acid trimers and tetramers, respectively. In the ESI‐MS/MS measurement, LPLA yielded three types of product ion series, while CPLA yielded only one type, from which the repeated units of CPLA were removed. The MS/MS spectrum of the NH4+ adduct ion for both cyclic and linear PLA showed loss of one ammonia molecule. The postsource decay (PSD) spectrum of CPLA by matrix‐assisted laser desorption ionization (MALDI) mass spectrometry was similar to the ESI‐MS/MS spectrum, while that of LPLA was different. In addition, the degradation of cyclic and linear PLAs by solvolysis was investigated. Solvolysis with anhydrous MeOH was quite feasible, but did not readily occur in the presence of even a small amount of water in the MeOH solvent. Copyright © 2006 John Wiley & Sons, Ltd.
Proliferation of anterior cruciate ligament cells in vitro by photo‐immobilized epidermal growth factor
Authors: Woo Young Kyun , Kwon Soon Yong , Lee Hwa Sung , Park Yong Soon 
Published: September 2006

AbstractThe purpose of this study was to explore the early treatment potential of anterior cruciate ligament (ACL) injuries using artificial juxtacrine stimulation by photo‐immobilization of a growth factor. A photo‐reactive epidermal growth factor complex (EGF‐Az) was synthesized by conjugating EGF with N‐(4‐azidobenzoyloxy) succinimide followed by immobilization onto polystyrene culture plates using UV irradiation. ACL cells from human tissues (1 × 105cells, 100 µl/well) were cultured as follows: control, no EGF; 50 µl native EGF; 50 µl EGF‐Az immobilized; and 100 µl EGF‐Az immobilized. The ACL cells were cultured long‐term and evaluated for possible differences in their responses to EGF. An in vitro wound closure assay was developed to enable examination of cellular proliferation and migration. ACL cell proliferation was most evident in the photo‐immobilized EGF culture group and was seen to increase in proportion to the amount of added EGF. In the in vitro wound closure assay, the lesioned area at 72 h after culture initiation was indistinguishable in the photo‐immobilized cultures, but remained clearly visible in the controls. We conclude that photo‐immobilized EGF induced rapid proliferation of ACL fibroblast cells by artificial juxtacrine stimulation and speculate that similar EGF immobilization onto bioabsorbable material (e.g., polyglycolic acid or polylactic acid) might contribute to a new therapy for the treatment of ACL injuries. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:73–80, 2007
An analysis of intertaxa differences in sulfur concentration in angiosperms
Authors: Willey Neil , Wilkins Janine 
Published: September 2006

AbstractUnderstanding the behavior of sulfur (S) in the soil‐plant system is important for crop production, for predicting the movement of the radioisotope 35S in the environment, and for investigating the role of S in plant metabolism of xenobiotics. A database of relative mean S concentrations in 121 species of flowering plants was constructed using a Residual Maximum Likelihood (REML) procedure with new experimental data for 76 species and literature data for 57 species, there being 12 species in common. The relative mean S concentrations in plant species were normally distributed and their range greater than previously reported for S concentrations between plant species. There was a significant phylogenetic effect on S concentrations when they were analyzed using a nested ANOVA coded with a recent phylogeny of flowering plants. About 36% of the variance between species was associated with the rank of Order and above. At the rank of Order, S concentrations were Brassicales > Malphigiales > Lamiales > Rosales > Caryophyllales > Malvales > Poales > Fabales > Fagales > Asterales. Experiments to quantify intervarietal differences within Beta vulgaris, Triticum aestivum, and Cicer arietinum revealed that these reached a maximum in B. vulgaris at about 20% of those found at the species level and above. A comparison of relative mean S concentrations with previously reported relative mean concentrations for heavy metals suggested correlations between S and cadmium (Cd), and S and zinc (Zn). The frequency distributions and phylogenetic effects reported here are useful to understanding soil‐plant transfer of stable and radioactive S isotopes in agricultural and natural ecosystems and might aid investigations of plant response to xenobiotics.
Bodengefüge gegen Verdichtungen schützen – Lösungsansätze für den Schutz landwirtschaftlich genutzter Böden
Authors: Lebert Matthias , Brunotte Joachim , Sommer Claus , Böken Holger 
Published: September 2006

AbstractFür den nachhaltigen Schutz des Bodens und seiner Funktionen fordert das deutsche Bundes‐Bodenschutzgesetz eine wirksame Vorsorge bei der Bodennutzung und – sofern die Gefahr des Eintretens einer schädlichen Bodenveränderung besteht – Maßnahmen zur Gefahrenabwehr. Die Ergebnisse eines Forschungsprojektes des Umweltbundesamtes haben gezeigt, dass ein Bodengefügeschaden durch Verdichtung anhand bodenkundlicher Kriterien ermittelt werden kann. Die so angezeigte Beeinträchtigung von Bodenfunktionen reicht zum Nachweis einer schädlichen Bodenveränderung im Sinne des Gesetzes jedoch alleine nicht aus, da die Erheblichkeit der Beeinträchtigungen und der Bezug zu Schutzgütern nicht hinreichend geklärt sind. Hierzu wäre eine weitere Sachverhaltsermittlung vor Ort notwendig.Fachansätze aus der Landtechnik und der Bodenphysik schlagen Vorgehensweisen für den Schutz des Bodengefüges gegen Verdichtungen vor, die sich an den Grundsätzen der Vorsorge orientieren. Die einzelnen Ansätze haben unterschiedliche Zielsetzungen und Einsatzbereiche und stellen deshalb jeweils Lösungen für Teilbereiche des Verdichtungsschutzes dar. Das landtechnische Bewertungskonzept der „Befahrbarkeit anhand der Spurtiefe”︁ gibt Aufschluss über die Verdichtung des Gesamtbodens unter Praxisbedingungen, ohne eine Differenzierung zwischen den betroffenen Bodenschichten. Das bodenphysikalische Konzept „Schadverdichtungsgefährdungsklassen”︁ ist auf eine Beurteilung der Krumenverdichtung nach Ertragsgesichtspunkten ausgerichtet. Die bodenphysikalischen Konzepte „Vorbelastung”︁ und „Belastungsquotient”︁ liefern für den Risikofeuchtebereich der Feldkapazität Prognosen für die Unterbodenverdichtung und die Veränderung von Bodenfunktionen in Krume und Unterboden.Für eine abschließende Bewertung der Prognosen der einzelnen Fachansätze ist eine weitere Validierung anhand zusätzlicher regionalisierter Daten zum Bodengefüge nötig. Für eine bundesweite Beurteilung der Gefahr von Gefügeschäden durch Bodenverdichtungen liegen gegenwärtig noch nicht genügend Erfahrungen in der Anwendung vor.
Simplifying the evaporation method for quantifying soil hydraulic properties
Authors: Schindler Uwe , Müller Lothar 
Published: September 2006

AbstractSince about 25 years, we have measured the unsaturated hydraulic conductivity function and water retention curve with the evaporation method of more than 1500 mineral and organic soils samples. From this data base, 104 representative samples of varying texture and dry bulk density were selected and the temporal dynamics of the basic measured values (mass or water loss, respectively, and tension change over time) was analyzed. With the exception of sand, water loss per time interval was constant in all other mineral and organic soils during the measuring time in the tension range between 0 and about 60 kPa. In sands, the nonlinear water loss over time by evaporation can be described by a quadratic function with high accuracy (r2 > 0.99). For all other soils, a linear function is sufficient (r2 > 0.99). The use of evaporation functions enables extending weighing intervals. This reduces costs for the measuring equipment and increases the effectiveness of the method while maintaining the same quality of unsaturated hydraulic conductivity and water retention functions. It was confirmed that measuring with two tensiometers is sufficient for accurate hydraulic conductivity and water retention function. Reducing evaporation by screening the sample surface helps to decrease hydraulic gradients and keeps tension distributions approximately linear with depth. This is recommended in particular for clayey soils.
Genotypic variation in grain cadmium concentration of lowland rice
Authors: He Junyu , Zhu Cheng , Ren Yanfang , Yan Yuping , Jiang Dean 
Published: September 2006

AbstractCadmium (Cd) contamination of paddy rice soils is commonly observed in the Yangtse River Delta, China. Large Cd uptake by rice plants and its translocation into the grains can entail human‐health risks. Genotypic variations in Cd uptake and a differential Cd partitioning into grains will be the basis for developing a rice screening or breeding tool for low grain Cd. A field experiment, conducted at the experimental farm of Jiaxing, Zhejiang province from 2002 to 2004, compared 38 rice genotypes of different types (indica vs. japonica) collected from the Yangtse River Delta. The results showed large differences in Cd concentrations in straw, brown rice, and grain chaff among the rice genotypes grown on Cd‐contaminated soil. Concentrations in brown rice ranged from 0.06 to 0.99 mg Cd kg–1. The total Cd uptake in brown rice varied between 0.96 and 28.58 μg plant–1. In general, indica‐type cultivars accumulated significantly more Cd than the japonica‐type cultivars. The Cd concentration in straw was highly correlated with that in brown rice. While significant differences in the Cd‐partitioning ratio (% share of total Cd uptake found in brown rice) among rice genotypes were observed, these were not correlated with Cd concentration of brown rice. This indicates that the Cd accumulation in rice grains appears to be governed mainly by the Cd uptake by the plant and probably not by differential Cd partitioning. The large genotypic variation suggests the possibility to lower the Cd content of rice by genotype selection. The development of such breeding tools should focus on low Cd uptake rather than Cd partitioning between straw and grain.
Mist culture for mass harvesting of root border cells: aluminum effects
Authors: Yu Min , Ming Feng Ying , Goldbach Heiner E. 
Published: September 2006

AbstractRoot border cells, which form a cell layer around the root tip, seem to play multiple roles in the rhizosphere of the apical root. As these cells (species‐dependent dozens to several thousand per root tip) are rapidly sloughed off in water, studies in hydroponic culture fail to elucidate their role in most conventional physiological studies. The common method for harvesting these cells consists in germination of seeds in a humid atmosphere (usually a Petri dish), but labor and time constraints allow to yield only very limited amounts of uniform cells. We thus developed a low‐cost mist‐culture method, where intact border cells can be collected in the range of several grams. We applied this technique in a preliminary experiment where the influence of aluminum (Al) supply on calcium (Ca) release and viability of this cell type was studied. Purified detached border cells of pea were incubated with 0, 50, and 500 mmol m–3 AlCl3 solution (pH 4.5) for 90 min at a ratio of 3 × 105 cells (4 mL)–1. After incubation, cells contained 4.27 and 13.28 mg Al g–1 C at 50 mmol m–3 and 500 mmol m–3 AlCl3, respectively, while their total Ca content decreased correspondingly. Cell viability of border cells as tested by fluorescein diacetate‐propidium iodide (FDA‐PI) fluorescence yielded unexpected results: the test exhibited significantly lower vitality at 50, but not at 500 mmol m–3 AlCl3. Assessing mitochondrial activity by 3‐(4,5)‐dimethylthiazol‐2‐yl‐2,5 diphenyl‐tetrazolium‐bromide (MTT) reduction showed that viability decreased in a dose‐dependent manner with increasing Al concentrations. This apparent contradiction is attributed to the formation of dense mucilage around border cells at high Al concentrations, which likely inhibits the access of the dye PI or may chemically inactivate this compound and thus wrongly suggest higher viability. Mist culture allows harvesting selectively large amounts of homogeneous border cells quickly and to study their physiological reactions separated from the root tip.
Evaluation of arbuscular mycorrhiza with symbiotic and nonsymbiotic pea isolines at three sites in the Alentejo, Portugal
Authors: Kleikamp Bernd , Joergensen Rainer Georg 
Published: September 2006

AbstractProviding an appropriate negative control for the experimental factor arbuscular mycorrhiza (AM) is a fundamental methodological problem. Therefore, the nonmycorrhizal (myc –) and nonnodulating (nod –) pea (Pisum sativum L.) mutant P2 was studied together with the parental symbiotic isogenetic variety Frisson in three experiments: (1) growth response to water supply in a climate chamber under nonsymbiotic growth conditions, (2) field evaluation at three sites in the Alentejo, South Portugal, and (3) growth response to P supply in a soil low in available P in a greenhouse‐chamber experiment. In the climate chamber at high NPK levels, mutant P2 achieved the same biomass as Frisson at 80% and 40% water‐holding capacity, respectively. For the field evaluation, three sites were chosen with normal arable use (Évora), extensive use as Montado (Portel), and intensive horticultural use (Mitra). The colonization of pea roots with AM fungi ranged from 4% (Mitra) to more than 90% (Portel), probably caused by differences in P availability. The plant density of mutant P2 was generally 25% lower than that of Frisson. Yield indices were all lowest at Portel, despite the same NPK fertilization. Grain and shoot yield of mutant P2 did not reach the level of Frisson at any site. Differences in N and P concentrations between the two isolines were insignificant in most cases. Differences in the amount of shoot P per plant consistently mirrored the mycorrhizal status of the three sites. Roughly 50% of the yield depression per m2 could be attributed to the lower plant density of mutant P2, the remaining 50% must be caused by AM‐fungal colonization or other factors. In the final pot experiment using the soil with low P availability from Portel, the main benefit of AM for peas was enhanced P uptake. Central questions could not be answered using a nonmycorrhizal control. However, mutants remain one interesting tool, best be used in combination with other approaches to estimate the effects of mycorrhization.
Natural wetland restoration and the use of municipal wastewater
Authors: Velty Silke , Behrendt Axel , Zeitz Jutta 
Published: September 2006

AbstractThe paper deals with the rewetting of minerotrophic peat soils in lysimeters by means of purified municipal wastewater in different quantities as well as the ability of Phragmites australis to remove nutrients and to enhance wastewater “treatment”. The use of purified municipal wastewater could be an alternative solution for water supply required during rewetting of peat soils. The inputs and outputs at the lysimetric systems in the Havelländisches Luch (Brandenburg) were sampled over a period of 45 months (2001–2004) in order to determine nutrient balances. The aim was to examine potential environmental risks when using municipal wastewater for minerotrophic peat‐soil rewetting as alternative for water shortage in NE Germany since addition of both N and P contribute to eutrophication but not exclusively to evaluate the purification capacity of the peat soil. Even for highest input loadings, there was no discernible discharge water–quality impact over operation time. Summary results showed high percentages of removal by plants for inorganic N, P, and micronutrients. Highest removal in soil and belowground biomass was supposed for inorganic N, P, K, Ca, Mg, and Cu.