bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oral tissue response to ovine grafting biomaterial: Morphological and morphometric study using scanning electron and light microscopy tissue response to ovine grafting biomaterial
Authors: Zielak Joao Cesar , Mathias Alvaro Luiz , Silva Rosiellen Da , Ton Bruno Skronski , Cidral Sobreiro Aline Graziela , Giovanini Allan Fernando , Deliberador Tatiana Miranda , Filho Flares Baratto , Ulbrich Lucienne Miranda 
Published: May 2012

AbstractOBJECTIVE: To evaluate the oral tissue response to an experimental particle ovine biomaterial by scanning electron microscopy (SEM) and light microscopy (LM). MATERIAL AND METHODS: Forty‐eight rats had surgical periodontal defects treated with either blood clotting (control), bovine biomaterial™ (B), or an experimental ovine biomaterial (O). Data from SEM analysis (defect exposure, root surface exposure, diameter of matrix fibers and bundles, and globuli areas; n = 5) were applied to Shapiro–Wilk, Kruskal–Wallis, and Dunn's test, whereas LM analysis (tissue cicatrization characteristics and diameter defect; n = 3) had data applied to two‐way analysis of variance. Animals were monitored for 1 and 3 weeks. RESULTS: By SEM, the O samples showed significant differences from B and C in the area of defect exposure (H2,15 = 8.66; P < 0.05). In both periods, O and B samples showed similar results for matrix fiber diameters, differently than C samples (H2,15 = 14.0; P < 0.05). All other SEM variables were considered equivalent among the groups (P > 0.05). Under LM, an acute and chronic granulomatous inflammation was seen in the presence of both biomaterials (B and O, 1 week); both the control and the ovine grafting samples showed mature bone in the repair site (3 weeks); the defect diameter showed similar values among groups, at both monitoring periods (F2,12 = 1.0401; P > 0.05). CONCLUSION: The ovine particles of this study showed a favorable response to oral tissue repair, demonstrating to be a potential source for the development of bone grafting biomaterials. Microsc. Res. Tech. 2012. © 2012 Wiley Periodicals, Inc.
Effect of processing methods for transmission electron microscopy on corneal collagen fibrils diameter and spacing
Authors: Akhtar Saeed 
Published: May 2012

AbstractIntroduction: The corneal tissue was processed in fixatives and embedded in resin for transmission electron microscopy to observe the ultrastructure of the collagen fibrils (CFs). The effect of these processing methods on the CF diameter and the interfibrillar spacing was studied. Methods: Four normal human corneal buttons were used for this study. A part of each cornea was fixed in 2.5% glutaraldehyde containing cuprolinic blue in sodium acetate buffer and embedded in spurr's resin (SpurrCB). A second part of each cornea was fixed in 2.5% glutaraldehyde + osmium tetroxide and embedded spurr's resin (SpurrOsm). The third part of each cornea was fixed in paraformaldehyde (4%) and embedded in LR White at 4°C (LRWhite). Ultrathin sections were stained with uranyl acetate and lead citrate. Results: In the tissue, fixed in SpurrCB, the diameter was 38.4 ± 5.9 nm and spacing between CF was 52.5 ± 5.3 nm. In the tissue fixed in SpurrOsm, the diameter was 28.37 ± 5.84 nm and spacing between CF was 45 ± 4.57 nm. In the tissue fixed in LR White, the CF diameter was 24 ± 2.3 nm and spacing between CF was 39.0 ± 4.2 nm. The diameters and interfibrillar spacing of the tissue processed by SpurrCB, SpurrOsm, and LRWhite were significantly different (P < 0.001) from one another. Conclusion: Our study shows that there is a variation in the CF diameter and spacing depending on the method of fixation and embedding resins used. This needs to be considered when comparative studies using different methods are done. Microsc. Res. Tech. 2012. © 2012 Wiley Periodicals, Inc.
A cell‐based smoothed discrete shear gap method using triangular elements for static and free vibration analyses of Reissner–Mindlin plates
Authors: Nguyen‐Thoi T. , Phung‐Van P. , Nguyen‐Xuan H. , Thai‐Hoang C. 
Published: May 2012

SUMMARYThe cell‐based strain smoothing technique is combined with discrete shear gap method using three‐node triangular elements to give a so‐called cell‐based smoothed discrete shear gap method (CS‐DSG3) for static and free vibration analyses of Reissner–Mindlin plates. In the process of formulating the system stiffness matrix of the CS‐DSG3, each triangular element will be divided into three subtriangles, and in each subtriangle, the stabilized discrete shear gap method is used to compute the strains and to avoid the transverse shear locking. Then the strain smoothing technique on whole the triangular element is used to smooth the strains on these three subtriangles. The numerical examples demonstrated that the CS‐DSG3 is free of shear locking, passes the patch test, and shows four superior properties such as: (1) being a strong competitor to many existing three‐node triangular plate elements in the static analysis; (2) can give high accurate solutions for problems with skew geometries in the static analysis; (3) can give high accurate solutions in free vibration analysis; and (4) can provide accurately the values of high frequencies of plates by using only coarse meshes. Copyright © 2012 John Wiley & Sons, Ltd.
Analyzing interaction between coplanar square cracks using an efficient boundary element‐free method
Authors: Sun Yuzhou , M Liew K. 
Published: May 2012

SUMMARYThis paper examines the interaction between coplanar square cracks by combining the moving least‐squares (MLS) approximation and the derived boundary integral equation (BIE). A new traction BIE involving only the Cauchy singular kernels is derived by applying integration by parts to the traditional boundary integral formulation. The new traction BIE can be directly applied to a crack surface and no displacement BIE is necessary because all crack boundary conditions (both upper and lower ones) are incorporated. A boundary element‐free method is then developed by combining the derived BIE and MLS approximation, in which the crack opening displacement is first expressed as the product of weight functions and the characteristic terms, and the unknown weight is approximated with the MLS approximation. The efficiency of the developed method is tested for isotropic and transversely isotropic media. The interaction between two and three coplanar square cracks in isotropic elastic body is numerically studied and the case of any number of coplanar square cracks is deduced and discussed. Copyright © 2012 John Wiley & Sons, Ltd.
Use of mutation profiles to refine the classification of endometrial carcinomas
Authors: McConechy Melissa K , Ding Jiarui , Cheang Maggie CU , Wiegand Kimberly C , Senz Janine , Tone Alicia A , Yang Winnie , Prentice Leah M , Tse Kane , Zeng Thomas , McDonald Helen , Schmidt Amy P , Mutch David G , McAlpine Jessica N , Hirst Martin , Shah Sohrab P , Lee Cheng‐Han , Goodfellow Paul J , Gilks C Blake , Huntsman David G 
Published: May 2012

AbstractThe classification of endometrial carcinomas is based on pathological assessment of tumour cell type; the different cell types (endometrioid, serous, carcinosarcoma, mixed, undifferentiated, and clear cell) are associated with distinct molecular alterations. This current classification system for high‐grade subtypes, in particular the distinction between high‐grade endometrioid (EEC‐3) and serous carcinomas (ESC), is limited in its reproducibility and prognostic abilities. Therefore, a search for specific molecular classifiers to improve endometrial carcinoma subclassification is warranted. We performed target enrichment sequencing on 393 endometrial carcinomas from two large cohorts, sequencing exons from the following nine genes: ARID1A, PPP2R1A, PTEN, PIK3CA, KRAS, CTNNB1, TP53, BRAF, and PPP2R5C. Based on this gene panel, each endometrial carcinoma subtype shows a distinct mutation profile. EEC‐3s have significantly different frequencies of PTEN and TP53 mutations when compared to low‐grade endometrioid carcinomas. ESCs and EEC‐3s are distinct subtypes with significantly different frequencies of mutations in PTEN, ARID1A, PPP2R1A, TP53, and CTNNB1. From the mutation profiles, we were able to identify subtype outliers, ie cases diagnosed morphologically as one subtype but with a mutation profile suggestive of a different subtype. Careful review of these diagnostically challenging cases suggested that the original morphological classification was incorrect in most instances. The molecular profile of carcinosarcomas suggests two distinct mutation profiles for these tumours: endometrioid‐type (PTEN, PIK3CA, ARID1A, KRAS mutations) and serous‐type (TP53 and PPP2R1A mutations). While this nine‐gene panel does not allow for a purely molecularly based classification of endometrial carcinoma, it may prove useful as an adjunct to morphological classification and serve as an aid in the classification of problematic cases. If used in practice, it may lead to improved diagnostic reproducibility and may also serve to stratify patients for targeted therapeutics. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Activation of Wnt signalling promotes development of dysplasia in Barrett's oesophagus
Authors: Moyes Lisa H , McEwan Hamish , Radulescu Sorina , Pawlikowski Jeff , Lamm Catherine G , Nixon Colin , Sansom Owen J , Going James J , Fullarton Grant M , Adams Peter D 
Published: May 2012

AbstractBarrett's oesophagus is a precursor of oesophageal adenocarcinoma, via intestinal metaplasia and dysplasia. Risk of cancer increases substantially with dysplasia, particularly high‐grade dysplasia. Thus, there is a clinical need to identify and treat patients with early‐stage disease (metaplasia and low‐grade dysplasia) that are at high risk of cancer. Activated Wnt signalling is critical for normal intestinal development and homeostasis, but less so for oesophageal development. Therefore, we asked whether abnormally increased Wnt signalling contributes to the development of Barrett's oesophagus (intestinal metaplasia) and/or dysplasia. Forty patients with Barrett's metaplasia, dysplasia or adenocarcinoma underwent endoscopy and biopsy. Mice with tamoxifen‐ and β‐naphthoflavone‐induced expression of activated β‐catenin were used to up‐regulate Wnt signalling in mouse oesophagus. Immunohistochemistry of β‐catenin, Ki67, a panel of Wnt target genes, and markers of intestinal metaplasia was performed on human and mouse tissues. In human tissues, expression of nuclear activated β‐catenin was found in dysplasia, particularly high grade. Barrett's metaplasia did not show high levels of activated β‐catenin. Up‐regulation of Ki67 and Wnt target genes was also mostly associated with high‐grade dysplasia. Aberrant activation of Wnt signalling in mouse oesophagus caused marked tissue disorganization with features of dysplasia, but only selected molecular indicators of metaplasia. Based on these results in human tissues and a mouse model, we conclude that abnormal activation of Wnt signalling likely plays only a minor role in initiation of Barrett's metaplasia but a more critical role in progression to dysplasia. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
MYC‐regulated genes involved in liver cell dysplasia identified in a transgenic model of liver cancer
Authors: Hunecke Danele , Spanel Reinhard , Länger Florian , Nam Suk Woo , Borlak Juergen 
Published: May 2012

AbstractFoci of liver cell dysplasia (LCD) are distinct morphological entities and may evolve into hepatocellular carcinomas (HCCs). While most HCCs overexpress c‐Myc, its role in LCD remains uncertain. Therefore, a c‐Myc transgenic model of HCC was investigated to understand the genetic events forcing liver cells into dysplasia and subsequent malignant transformation. Specifically, whole genome scans enabled fingerprinting of genes at different stages of disease, ie LCD and HCC, while laser microdissected LCD lesions were used to validate regulation of candidate genes by quantitative real‐time RT‐PCR, ieMybbp1a, Rps7, Rps19, Rpl10a, Skp1a, Tfdp1, Nhp2, andBola2. EMSA band shift assays confirmed c‐Myc DNA binding at regulatory sequences of candidate gene‐specific promoters. Additionally, published ChIP‐seq data helped to define the candidate genes as c‐Myc bona fide targets. Treatment of the human hepatoma cell line HepG2 with hepatic growth factor (Hgf) caused c‐Myc protein induction and transcriptional up‐regulation of candidate genes, albeit at different levels when individual genes were compared. A significant increase of HepG2 entering the G1‐phase was associated with up‐regulation of the candidate genes in an Hgf concentration‐dependent matter. Finally, we confirmed regulation of candidate genes in patients' samples with low‐ and high‐grade dysplasia and HCC staged T1 to T3, while their expression was unchanged in focal nodular hyperplasia and hepatic adenoma, therefore asserting the diagnostic value and clinical significance of these candidate genes. Overall, novel c‐Myc targeted genes were identified and may contribute to hepatocyte transformation by altering cell cycle control, thereby contributing to c‐Myc's oncogenic activity. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
New epoxy thermosets obtained from diglycidylether of bisphenol a and modified hyperbranched polyesters with long aliphatic chains cured by diisocyanates
Authors: Flores Marjorie , Fernández‐Francos Xavier , Jiménez‐Piqué Emilio , Foix David , Serra Àngels , Ramis Xavier 
Published: May 2012

AbstractHyperbranched polyesters modified with long aliphatic chains with vinyl or epoxy groups as chain ends were synthesized and added as modifiers to diglycidyl ether of bisphenol A/toluene‐2,4‐diisocyanate mixtures in the presence of benzyldimethylamine as catalyst. The influence of the addition of these modifiers on the curing was investigated by thermal analysis and infrared spectroscopy. The materials obtained were investigated by electron microscopy and some mechanical characteristics were determined by nanoindentation tests. Epoxy terminated hyperbranched led to homogeneous materials with high crosslinking densities, whereas vinyl terminated hyperbranched produced phase separated morphologies. The materials showing phase separation presented a tough fracture, whereas the homogeneous materials obtained with epoxidated hyperbranched showed increased brittleness on increasing the proportion of modifier. On increasing the proportion of vinyl terminated hyperbranched in the thermosets, Young's modulus and hardness decreased but the addition of epoxy terminated hyperbranched did not influence these parameters. The addition of vinylic hyperbranched to the formulations produced a decrease in the curing shrinkage, whereas the epoxidic hyperbranched did not. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Aliphatic–aromatic polyester–polyaniline composites: preparation, characterization, antibacterial activity and conducting properties
Authors: Wu Chin‐San 
Published: May 2012

AbstractPoly(butylene adipate‐co‐terephthalate) (PBAT) composites containing polyaniline (PANI) were prepared using a melt blending process. Acrylic‐acid‐grafted PBAT (PBAT‐g‐AA) and PANI were used to improve the compatibility and dispersibility of PANI within the PBAT matrix. The composites were characterised morphologically using scanning electron microscopy, chemically using Fourier transform IR spectrometry and 13C solid‐state nuclear magnetic resonance, and optically using UV‐visible spectroscopy. The electrical conductivity of the composites was also evaluated with a resistance tester and a cyclic voltameter. Escherichia coli (BCRC 10239) was chosen as the standard bacterium for determining the antibacterial properties of the composite materials. The anti‐static properties of the composites were also evaluated. The PBAT‐g‐AA/PANI composite showed markedly enhanced antibacterial and anti‐static properties due to the formation of amide bonds by the condensation of the carboxylic acid groups of PBAT‐g‐AA with the amino groups of PANI. The optimal level of PANI was 9 wt%, as excess PANI led to separation of the two organic phases, lowering their compatibility. Copyright © 2012 Society of Chemical Industry
Molecular dynamics simulation of thionated hen egg white lysozyme
Authors: Huang Wei , Eichenberger Andreas P. , van Gunsteren Wilfred F. 
Published: May 2012

AbstractUnderstanding of the driving forces of protein folding is a complex challenge because different types of interactions play a varying role. To investigate the role of hydrogen bonding involving the backbone, the effect of thio substitutions in a protein, hen egg white lysozyme (HEWL), was investigated through molecular dynamics simulations of native as well as partly (only residues in loops) and fully thionated HEWL using the GROMOS 54A7 force field. The results of the three simulations show that the structural properties of fully thionated HEWL clearly differ from those of the native protein, while for partly thionated HEWL they only changed slightly compared with native HEWL. The analysis of the torsional‐angle distributions and hydrogen bonds in the backbone suggests that the α‐helical segments of native HEWL tend to show a propensity to convert to 310‐helical geometry in fully thionated HEWL. A comparison of the simulated quantities with experimental NMR data such as nuclear overhauser effect (NOE) atom–atom distance bounds and 3JHNHα‐couplings measured for native HEWL illustrates that the information content of these quantities with respect to the structural changes induced by thionation of the protein backbone is rather limited.
Resistance testing and the effectiveness of difenacoum against Norway rats (Rattus norvegicus) in a tyrosine139cysteine focus of anticoagulant resistance, Westphalia, Germany
Authors: Buckle Alan , Endepols Stefan , Klemann Nicole , Jacob Jens 
Published: May 2012

AbstractBACKGROUND: Anticoagulant resistance in Norway rats at foci in Belgium, Denmark, France, Germany, the Netherlands and the United Kingdom is genetically characterised by the same single nucleotide polymorphism (SNP) and consequent amino acid exchange from tyrosine to cysteine at location 139 of the vkorc1 gene (i.e. tyrosine139cysteine or Y139C). The purpose of this study was to assess the degree of resistance among rats at two infested farm sites in the Y139C focus in Westphalia, Germany, using blood clotting response (BCR) tests, and to determine the practical efficacy of applications of a commercial 50 ppm difenacoum bait (Neokil™) against them.RESULTS: BCR tests showed that the difenacoum resistance factor (RF) among the Y139C rats was about 2.5. DNA analysis for the Y139C mutation revealed that it was present among rats at the two sites with a prevalence of 75 and 93%. Applications of difenacoum bait at the two sites achieved 86.8 and 59.9% control. The different outcomes did not appear to be due to differences either in the degree and prevalence of resistance or in the quantities of poisoned bait consumed.CONCLUSION: The study showed that, although the RF for difenacoum among rats carrying the Y139C SNP was apparently low, an acceptable level of control of resistant Norway rat infestations was not achieved using difenacoum. Continued use of anticoagulants against rats that are resistant to them will exacerbate resistance problems in terms of both increased severity and prevalence. These conclusions are likely to apply elsewhere in Europe where the Y139C SNP occurs. Copyright © 2012 Society of Chemical Industry
Quantum chemical insights into the dissociation of nitric acid on the surface of aqueous electrolytes
Authors: Mishra Himanshu , Nielsen Robert J. , Enami Shinichi , Hoffmann Michael R. , Colussi Agustín J. , Goddard William A. 
Published: May 2012

AbstractRecent experiments in our laboratory have shown that the probability of gaseous HNO3 deprotonation on the surface of water is dramatically enhanced by anions. Herein, we report a quantum chemical study of how a HNO3 molecule transfers its proton upon approaching water clusters containing or not a chloride ion. We find that HNO3 always binds to the outermost water molecules both via donating and accepting hydrogen‐bonds, but the free energy barrier for subsequent proton transfer into the clusters is greatly reduced in the presence of Cl−. As the dissociation of HNO3 embedded in water clusters is barrierless, we infer that interfacial proton transfer to water is hindered by the cost of creating a cavity for NO3−. Our findings suggest that nearby anions catalyze HNO3 dissociation by preorganizing interfacial water and drawing the proton—away from the incipient [H+‐‐‐NO3−] close ion‐pairs generated at the interface. This catalytic mechanism would operate in the 1 mM Cl− range (1 Cl− in ∼5.5 × 104 water molecules) covered by our experiments if weakly adsorbed HNO3 were able to explore extended surface domains before desorbing or diffusing (undissociated) into bulk water. © 2012 Wiley Periodicals, Inc.
Intra‐operative fluorescent cholangiography using indocyanin green during robotic single site cholecystectomy
Authors: Buchs Nicolas C. , Hagen Monika E. , Pugin François , Volonte Francesco , Bucher Pascal , Schiffer Eduardo , Morel Philippe 
Published: May 2012

AbstractBackground and study aimsVery recently, robotic single site cholecystectomy (RSSC) has been reported feasible and safe for selected cases. While an intra‐operative cholangiography can be performed, data is scarce with respect to its use. Indocyanin green (ICG) has been shown to be a viable option to visualize biliary anatomy. Since the introduction of a new near infrared camera integrated to the da Vinci Si System (Intuitive Surgical, Sunnyvale, CA), the surgeon is able to assess the biliary anatomy by a non‐invasive and non‐ionizing method. This paper presents the first report of ICG imaging during a RSSC.Patients and MethodsTwelve consecutive patients presenting symptomatic cholelithiasis were prospectively enrolled. They underwent RSSC approximately 45 minutes after intravenous administration of ICG (2.5 mg). The biliary anatomy was analyzed using a near infrared camera integrated to the robot before and after the robotic dissection.ResultsEight women and four men underwent the procedure. There was a port addition in one case and no peri‐operative complications. Mean operative time was 85 minutes (range: 57–125). The cystic, common bile and common hepatic ducts were recognized by fluorescence imaging before the dissection in 91.7%, 50%, and 33.3% of patients, respectively. At least one structure was visualized in 100% of patients. After the completion of Calot's triangle dissection, the cystic, common bile, and common hepatic ducts were recognized in 100%, 83.3%, and 66.7% of cases respectively.ConclusionsRSSC using ICG for biliary tree fluorescence imaging can be performed safely. Fluorescent cholangiography enabled real‐time identification of the extra‐hepatic biliary anatomy using a near infrared camera integrated to the robot. Its routine clinical use merits further investigations. Copyright © 2012 John Wiley & Sons, Ltd.