bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nonfouling biomaterials based on polyethylene oxide‐containing amphiphilic triblock copolymers as surface modifying additives: Adsorption of proteins from human plasma to copolymer/polyurethane blends
Authors: Tan J. , Brash J.L. 
Published: May 2008

AbstractThree polyethylene oxide‐polyurethane‐polyethylene oxide (PEO‐PU‐PEO) block copolymers of variable PEO block size (MW 550, 2000, and 5000) were used to modify the surface of a conventional segmented polyurethane (PU) with the objective of inhibiting interactions with proteins. The surface‐active copolymers were blended with the PU by solution methods. Protein adsorption from human plasma to the modified materials was investigated using radiolabeling and immunoblotting methods. From the radiolabeling experiments, it was found that fibrinogen adsorption from plasma to all of the modified surfaces was much lower than to the unmodified PU matrix. For blends of low copolymer content, resistance to adsorption was greatest on the copolymer 1 (PEO550)‐modified materials, and increased with increasing copolymer content for all three blend types. At high copolymer content inhibition of adsorption was very strong and independent of PEO block size. The immunoblotting experiments showed that on materials of high copolymer content (20 wt %), the proteins investigated (fibrinogen, albumin, complement C3, and apolipoprotein A‐I) were undetectable. At low copolymer content (≤5 wt %), the blends of copolymer 1, with the shortest PEO block, exhibited greater protein resistance than those of copolymers 2 and 3 (PEO blocks of MW 2000 and 5000, respectively), and resistance decreased with decreasing protein size. Evidence of complement activation was seen for the blends of low copolymer content. Adsorption of C3 and complement activation decreased with increasing content of the copolymers. It was concluded that surface density of PEO is more important than chain length for protein resistance in contact with plasma. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Tubular nanofiber scaffolds for tissue engineered small‐diameter vascular grafts
Authors: He Wei , Ma Zuwei , Teo Wee Eong , Dong Yi Xiang , Robless Peter Ashley , Lim Thiam Chye , Ramakrishna Seeram 
Published: May 2008

AbstractQuick establishment of a confluent and stable endothelial cells (ECs) layer in the lumen of vascular grafts is critical for long‐term patency of small‐diameter vascular grafts. The objective of the study was to fabricate tubular nanofiber scaffolds, incorporate ECs onto the lumen of the scaffolds, and establish an animal model to prove the basic concept of using the scaffolds as vascular grafts. Poly(L‐lactic acid)‐co‐poly(ε‐caprolactone) P(LLA‐CL 70:30) tubular nanofiber scaffolds were fabricated by electrospinning onto a rotating mandrel. Collagen was coated onto the scaffolds after air plasma treatment. Structure and mechanical property of the scaffolds were studied by scanning electron microscopy and tensile stress measurement, respectively. Human coronary artery endothelial cells (HCAECs) were rotationally seeded onto the lumen of the scaffolds at the speed of 6 rpm for 4 h through a customized seeding device, followed with static culture. Results showed evenly distributed and well‐spread HCAECs throughout the lumen of the scaffold from 1 day onward to 10 days after seeding. Further, HCAECs maintained phenotypic expression of PECAM‐1. To prove the basic concept of using the scaffolds as vascular grafts, acellular tubular P(LLA‐CL) nanofiber scaffolds (inner diameter 1 mm) were implanted into rabbits to replace the inferior superficial epigastric veins. Results showed the scaffolds sustained the surgical process, kept the structure integrity, and showed the patency for 7 weeks. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Reliability of one‐piece ceramic implant
Authors: Silva Nelson R. F. A. , Coelho Paulo G. , Fernandes Carlos A. O. , Navarro Jose M. , Dias Renata Alves , Thompson Van P. 
Published: May 2008

AbstractThe fundamental aspects of damage initiation and accumulation in one‐piece zirconium oxide endosseous dental implants remain to be investigated. Aims: This study tested the null hypothesis that there is no influence on mouth‐motion fatigue reliability and failure modes between as‐received and after full crown preparation on one‐piece ceramic implants. Methods: Forty‐eight one‐piece Y‐TZP ceramic implants (Nobel Biocare, Goteborg, Sweden) were utilized. All specimens were embedded in acrylic resin exposing the first two threads at 30° angulation with respect to the vertical axis (as per ISO specification 14801). Full crown preparations were performed following prosthodontic guidelines for half of the specimens. As‐received and prepared specimens were distributed among three step‐stress profiles based on the specimens ultimate fracture strength. Specimens were step‐stress fatigued until failure or survival. A master Weibull curve was generated from the data and the reliability for completion of a mission of 50,000 cycles at 600 N load calculated. Results: No differences between the groups' reliability was observed. Failure mode for both groups was similar, where cracks initiated mainly at the tensile bending side of the second thread's internal diameter. The low Weibull modulus (<1) indicates that fatigue (<150,000 cycles) did not influence failure. Failure depended upon the applied load. Conclusion: Crown preparation did not influence the reliability of the one‐piece ceramic implant. The null hypothesis was accepted. Fatigue did not influence the life time of ceramic implants at loads under 600 N. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Biaxial flexure strength and low temperature degradation of Ce‐TZP/Al2O3 nanocomposite and Y‐TZP as dental restoratives
Authors: Ban Seiji , Sato Hideo , Suehiro Yasuhiko , Nakanishi Hideo , Nawa Masahiro 
Published: May 2008

AbstractThe purpose of the present study was to evaluate the mechanical durability of a zirconia/alumina nanocomposite stabilized with cerium oxide (Ce‐TZP/Al2O3 nanocomposite) in comparison to yttria‐stabilized tetragonal zirconia polycrystals (Y‐TZP) and discuss its application on ceramic dental restorations. The disk‐shaped specimens of both materials were stored in physiological saline solution at 80°C for 30 days, in 4% acetic acid at 80°C for 30 days, and in an autoclave at 121°C for 10 days. Before and after storage, specimens were subjected to the biaxial flexure test and to the determination of the monoclinic zirconia content. After autoclaving, Y‐TZP showed remarkable increasing of the content of monoclinic zirconia: 0.3 vol % before and 49.9 vol % after, and slight decreasing of biaxial flexure strength: 1046 MPa before and 892 MPa after; whereas Ce‐TZP/Al2O3 nanocomposite showed no significant difference in the monoclinic content (4.8–5.5 vol %) and the biaxial flexure strength (1371–1422 MPa) after storage in any conditions. It is concluded that, compared to Y‐TZP, the Ce‐TZP/Al2O3 nanocomposite has a high biaxial flexure strength along with a satisfactory durability in terms of low‐temperature aging degradation in above conditions. This study indicates that the Ce‐TZP/Al2O3 nanocomposite demonstrates excellent mechanical durability for dental restorations such as all‐ceramic bridges. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Induction of hepatocyte growth factor expression by maleic acid in human fibroblasts through MAPK activation
Authors: Motoki Takahiro , Sugiura Yoshihiro , Matsumoto Yohsuke , Tsuji Tomoe , Kubota Satoshi , Takigawa Masaharu , Gohda Eiichi 
Published: May 2008

AbstractCarboxylic acids have various biological activities and play critical roles in cellular metabolic pathways such as the tricarboxylic acid (TCA) cycle. It has been shown that some carboxylic acids induce cell proliferation and production of cytokines or growth factors. However, there have been no reports on effects of carboxylic acids on hepatocyte growth factor (HGF) expression. In this study, we found that only maleic acid among various carboxylic acids examined markedly induced HGF production from human dermal fibroblasts. Maleic acid also induced HGF production from human lung fibroblasts and neuroblastoma cells. The stimulatory effect was accompanied by upregulation of HGF gene expression. Increase in phosphorylation of extracellular signal‐regulated protein kinase (ERK) and c‐Jun N‐terminal kinase (JNK) but not in phosphorylation of p38 was observed from 6 h and up to 24 h after maleic acid addition. The ERK kinase inhibitor PD98059 and the JNK inhibitor SP600125 potently inhibited maleic acid‐induced HGF production, while the p38 inhibitor SB203580 did not significantly inhibit the production. The protein synthesis inhibitor cycloheximide completely inhibited upregulation of HGF mRNA induced by maleic acid but superinduced HGF mRNA expression upregulated by 12‐O‐tetradecanoylphorbol 13‐acetate (TPA). These results suggest that maleic acid indirectly induced HGF expression from human dermal fibroblasts through activation of ERK and JNK and that de novo protein synthesis is required for maleic acid‐induced upregulation of HGF mRNA. J. Cell. Biochem. 104: 1465–1476, 2008. © 2008 Wiley‐Liss, Inc.
Two‐ and three‐dimensional prenatal sonographic diagnosis of hepatic cysts
Authors: Wax Joseph R. , Grimes Charles K. , Blackstone Jacquelyn , Pinette Michael G. , Cartin Angelina 
Published: May 2008

AbstractWe describe the 2‐dimensional and 3‐dimensional multiplanar sonographic diagnosis and characterization of isolated hepatic cysts in 2 fetuses. Two‐dimensional imaging of a fetus at 36 weeks' gestation revealed 2 right upper quadrant cystic masses anterior to the gallbladder, demonstrating no peristalsis or blood flow. Postnatal sonographic examination confirmed 2 simple hepatic cysts. Two‐ and three‐dimensional sonograms suggested 2 hepatic cysts in a 23‐week‐old fetus that resolved by 33 weeks' gestation. In reporting 2 unusual cases of prenatally diagnosed fetal hepatic cysts, we also demonstrate the diagnostic use of 3‐dimensional multiplanar imaging. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2009
Contributions to the study of oviparity–viviparity transition: Placentary structures of Liolaemus elongatus (Squamata: Liolaemidae)
Authors: Crocco Melisa , Ibarguengoytía, Nora R. , Cussac Víctor 
Published: May 2008

AbstractLiolaemus elongatus (Liolaemidae) is a viviparous, mainly lecithotrophic species with placental structures specialized for uptake of oxygen and inorganic nutrient transport. An allantoplacenta and an omphaloplacenta are present during early embryonic stages (25–28) and there is a moderate distension of the uterine wall and major glandular activity in the uterine mucosa and submucosa compared with nonpregnant females. The uterine epithelium increases in height, first as a growth in the height of some dispersed cells localized in all regions of the placenta, and later as groups of cells localized in the periembryonic and central‐abembryonic regions. At embryonic stage 39, the allantoplacenta reaches its maximum extension around the yolk sac. Omphaloplacenta is restricted to the abembryonic zone, the yolk cleft limiting the newly formed isolated vitelline mass. At more advanced embryonic stages (39–42), the blood supply to the allantoplacenta's periembryonic zone increases, matching the profuse allantoic vascularization. At embryonic stage 42, a secondary cleft opens in the main vitelline mass, above the first yolk cleft, and allantoic blood vessels enter into this secondary cleft. This secondary cleft subdivides the vitelline mass into a large embryonic region connected to a much smaller abembryonic region. In L. elongatus most nutritional resources seem to be provided by the yolk that remains attached to the newborn for 2 or 3 days as an external supply. The embryo's wet weight doubles the weight of the decrease observed in vitelline mass. But the dry wet diminishes, evidencing the importance of the exchange of water and inorganic nutrients. J. Morphol., 2008. © 2008 Wiley‐Liss, Inc.
Decoupling morphological development from growth in periodically cooled zebra finch embryos
Authors: Olson Christopher R. , Vleck Carol M. , Adams Dean C. 
Published: May 2008

AbstractTemperature affects growth and development, and morphometry can provide a quantitative description of how temperature changes affect the resulting phenotype. We performed a morphometric analysis on zebra finch (Taeniopygia guttata) embryos that were either exposed to periodic cooling to 20 or 30°C throughout incubation over a background temperature of 37.5°C, or were incubated at a constant temperature of 37.5°C. Using a principle components analysis, we found that the relationship between the multivariate size (first principle component) and dry embryo mass depended upon the thermal treatment to which the developing embryos were exposed. Periodic cooling resulted in a smaller embryo mass, but had no effect on the multivariate size of the embryo. This suggests that the growth of phenotypic traits such as the length of long bones and the skull are less affected by temperature than is growth of other soft tissues such as muscle and organs that contribute to body mass. J. Morphol., 2008. © 2008 Wiley‐Liss, Inc.
The ontogeny of the shell in side‐necked turtles, with emphasis on the homologies of costal and neural bones
Authors: Scheyer Torsten M. , Brüllmann Benjamin , Sánchez‐Villagra Marcelo R. 
Published: May 2008

AbstractAlthough we are starting to understand the molecular basis of shell development based on the study of cryptodires, basic comparative ontogenetic data for the other major clade of living turtle, the pleurodires, are largely missing. Herein, the developmental and phylogenetic relation between the bony shell and endoskeleton of Pleurodira are examined by studying histological serial sections of nine specimens of three different species, including an ontogenetic series of Emydura subglobosa. Emphasis is given to the portion of the carapace in which ribs and vertebral spinous processes become part of the carapace. Central questions are how neurals and costals are formed in pleurodiran turtles, whether costals and neurals are of endoskeletal or exoskeletal origin, and what ontogenetic factors relate to neural reduction of some Pleurodira. The neurals and costals do not develop as independent ossification centers, but they are initial outgrowths of the periosteal collar of endoskeletal ribs and neural arches. Slightly later in development, the ossification of both shell elements continues without a distinct periosteum but by metaplastically ossifying precondensed soft‐tissue integumentary structures. Through ontogeny, ribs of the turtles studied are closely associated with the hypaxial intercostalis musculature while epaxial interspinalis musculature connects the neural arches. We here propose an alternative structural hypothesis for the neural reduction and, ultimately, the complete loss of the neural series. The complete reduction of neurals in Emydura spp. may be linked to heterochrony, accompanied by a restricted influence of epaxial musculature and epidermal–dermal interaction in shell bone formation. J. Morphol., 2008. © 2008 Wiley‐Liss, Inc.
Feeding ecology and morphology of the upper canines in bears (carnivora: Ursidae)
Authors: Christiansen Per 
Published: May 2008

AbstractThe morphology and mechanical strength of the upper canines in all eight extant species of ursids is analyzed, and the findings are discussed in relation to feeding ecology. Ursids have proportionally smaller canines than other large carnivores with a specialized feeding ecology, such as large felids, and the upper canine morphology is both canid‐like and felid‐like. The giant panda is the most divergent species, and its short, blunt, and cone‐like canines appear well adapted for tearing into bamboo. The almost equally herbivorous spectacled bear has a less derived canine morphology. The large canines of the sun bear are divergent from other ursine ursids, and may be an adaptation for tearing open tree trunks in search of insects. Discriminant Analysis is successful in separating ursid species on the basis of canine morphology, but the canines of ursine ursids, and also of the spectacled bear, show greater resemblance among the species than the marked differences in feeding ecology would suggest. This could be in part due to a short evolutionary history, and in part due to canines not having been subjected to much evolutionary selection as has been the case among other large carnivores, such as large felids. Ursids are probably evolutionarily and ecologically successful due to physical size and strength rather than a derived craniodental anatomy. J. Morphol., 2008. © 2008 Wiley‐Liss, Inc.
Holocene vegetation and climate dynamics of the boreal alpine ecotone of northwestern Fennoscandia
Authors: Jensen Christin , Vorren Karl‐Dag 
Published: May 2008

AbstractClimate change with respect to summer temperature throughout the Holocene is inferred from oscillations in the local Pinus sylvestris, Alnus incana and Betula pubescens forest‐lines, as recorded by fossil pollen and plant macrofossils in lake sediments at four altitudinal levels. Mt Skrubben (848 m a.s.l.), in Dividalen, was deglaciated down to below 280 m a.s.l. during 10 800–10 300 cal. yr BP. Betula pubescens established 10100 cal. yr BP at 280 m a.s.l. and expanded up to near the summit during the next 700 years. Birch woodland prevailed on the mountain plateau until 3300 cal. yr BP. Local Pinus sylvestris stands are recorded up to 400 m a.s.l. at 8450 cal. yr BP and >548 m a.s.l. about 8160 cal. yr BP. Alnus incana expanded from 400 to nearly 790 m a.s.l. during the period 7900–7600 cal. yr BP. The maximum forest distribution lasted until ca. 6000 cal. yr BP. Marked climatic deteriorations caused lowering of the forest‐lines around 4600 and 3000 cal. yr BP. Reconstruction of the summer temperature indicated mean July temperatures at 400 m a.s.l. of 1.5–3°C above the present during the period of maximum forest expansion, whereas >3°C above the present temperature at 548 m a.s.l. This is in accordance with other regional temperature reconstructions from northern Europe. Copyright © 2008 John Wiley & Sons, Ltd.
Mitotic checkpoint gene MAD1 in hepatocellular carcinoma is associated with tumor recurrence after surgical resection
Authors: Nam Chang Woo , Park Neung Hwa , Park Bo Ryung , Shin Jung Woo , Jung Seok Won , Na Yang Won , Seo Jae Hee 
Published: May 2008

AbstractObjectiveUnderlying mechanism of mitotic checkpoint gene mitosis arrest deficiency 1 (MAD1) in human hepatocellular carcinoma (HCC) is rarely known.Materials and MethodsWe studied genetic change of the MAD1 gene as well as protein expression in 44 HCC and their associated non‐cancerous surrounding liver tissues.ResultsGenotype AG of MAD1 G‐1849 A promoter was highly significant in microscopic vascular invasion than other genotypes (P = 0.006). Moreover, the mean tumor size of HCC with genotype AG (7.71 cm) was significantly larger than those of other genotypes (AA, 4.41 cm; GG, 4.59 cm; P = 0.033). After a median follow‐up of 22 months, 18 (41%) of the 44 patients relapsed. Eleven (32.4%) of 34 with MAD1 protein expression and 7 (70%) of 10 with no expression of MAD1 protein showed tumor recurrence. The incidence of tumor recurrence in patients with the lost MAD1 expression was significantly higher than in those with the expressed MAD1 protein (P = 0.011).ConclusionThese results suggest that MAD1 promoter genotype may be involved in tumor progression. Moreover, the loss of MAD1 protein expression may be related to the tumor recurrence after surgical resection of HCC. J. Surg. Oncol. 2008;97:567–571. © 2008 Wiley‐Liss, Inc.
Prediction of retention indices of drugs based on immobilized artificial membrane chromatography using Projection Pursuit Regression and Local Lazy Regression
Authors: Du Hongying , Watzl June , Wang Jie , Zhang Xiaoyun , Yao Xiaojun , Hu Zhide 
Published: May 2008

AbstractThe relationship between the logarithm of retention indices (log kIAM) of 55 diverse drugs in immobilized artificial membrane (IAM) chromatography and molecular structure descriptors was established by linear and non‐linear modeling methods – Projection Pursuit Regression (PPR) and lazy learning method‐Local Lazy Regression (LLR). The descriptors calculated from the molecular structures by the software CODESSA and a widely accepted property parameter ClogP were used to represent the characteristics of the compounds. The best multi‐linear regression (BMLR) method in the CODESSA was used to select the most important molecular descriptors from a large set of descriptors and to develop the linear and non‐linear quantitative structure retention relationship (QSRR) models. By comparing these different methods, the LLR model gave the best predictive results for the drugs studied in the present work with the square of correlation coefficient (R2) of 0.9540, 0.9305; root mean square error (RMSE) of 0.2418, 0.3949; for the training set and test set, respectively. It was proved that the LLR method was a promising method for QSRR modeling with good predictive capability for the retention indices of drugs in immobilized artificial membrane chromatography, and could be used in other similar chromatography research fields.
Chromatographic analysis of banned antibacterial growth promoters in animal feed
Authors: Samanidou Victoria F. , Evaggelopoulou Evaggelia N. 
Published: May 2008

AbstractThe issue of antimicrobial use in animals used as food is of global concern. Antimicrobials are used in animal agriculture to improve health and welfare of animals, meat quality, the economic efficiency of growth and production and public health by decreasing shedding of zoonotic pathogens. However, large quantities are often used without professional supervision. The growth‐promotant (now reclassified as zootechnical feed additives) effect of low levels of antibiotics in animal feeds was first described in the late 1940s. Already in 1969 the Swann Committee recommended that use of antibiotics as a supplement in animal feedstuff should be restricted to those with little or no application as therapeutic agents for humans and animals, which would not impair the efficacy of therapeutic antibiotics through the development of resistant strains of organisms. Antimicrobials like avoparcin, ardacin, zinc bacitracin, virginiamycin, tylosin, spriramycin, carbadox and olaquindox were withdrawn within the period 1997–1999. Four others (monensin sodium, salinomycin sodium, avilamycin and flavophospholipol) were still permitted for use as growth promoters in animal feed to animals marketed in the European Union (EU). Since January 2006, they have been banned as well. This review focuses on the analytical methods developed to be an effective tool for monitoring compliance with the ban.
Cyclodextrins in capillary electrophoresis enantioseparations – Recent developments and applications
Authors: Scriba Gerhard K. E.V. 
Published: May 2008

AbstractCapillary EKC has been established as a versatile and robust CE method for the separation of enantiomers. Within the chiral selectors added to the BGE CDs continue as the most widely used selectors due to their structural variety and commercial availability. This is reflected in the large number of practical applications of CDs to analytical enantioseparations that have been reported between January 2006 and January 2008, the period of time covered by this review. Most of these applications cover aspects of life sciences such as drug analysis, bioanalysis, environmental analysis, or food analysis. Moreover, new CD derivatives have been developed in an attempt to achieve altered enantioselectivities and to further broaden the application range. Finally, efforts will be summarized that aim at an understanding of the molecular level of the chiral recognition between CDs and the analytes.