bluuebunny/crossref_metadata_2025_split huggingface dataset:
Global microRNA profiles in cervical squamous cell carcinoma depend on Drosha expression levels
Authors: Muralidhar B , Goldstein LD , Ng G , Winder DM , Palmer RD , Gooding EL , Barbosa‐Morais NL , Mukherjee G , Thorne NP , Roberts I , Pett MR , Coleman N 
Published: April 2007

AbstractGain of chromosome 5p is seen in over 50% of advanced cervical squamous cell carcinomas (SCCs), although the genes responsible for the selective advantage provided by this abnormality are poorly understood. In the W12 cervical carcinogenesis model, we observed that 5p gain was rapidly selected over ∼15 population doublings and was associated with the acquisition of a growth advantage and invasiveness. The most significantly upregulated transcript following 5p gain was the microRNA (miRNA) processor Drosha. In clinically progressed cervical SCC, Drosha copy‐number gain was seen in 21/36 clinical samples and 8/10 cell lines and there was a significant association between Drosha transcript levels and copy‐number gain. Other genes in the miRNA processing pathway, DGCR8, XPO5 and Dicer, showed infrequent copy‐number gain and over‐expression. Drosha copy‐number and expression were not elevated in pre‐malignant cervical squamous intraepithelial lesions. Importantly, global miRNA profiling showed that Drosha over‐expression in cervical SCC appears to be of functional significance. Unsupervised principal component analysis of a mixed panel of cervical SCC cell lines and clinical specimens showed clear separation according to Drosha over‐expression. miRNAs most significantly associated with Drosha over‐expression are implicated in carcinogenesis in other tissues, suggesting that they regulate fundamental processes in neoplastic progression. Our evidence suggests that copy‐number driven over‐expression of Drosha and consequent changes in miRNAs are likely to be important contributors to the selective advantage provided by 5p gain in cervical neoplastic progression. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Single nucleotide polymorphism array analysis of chromosomal instability patterns discriminates rectal adenomas from carcinomas
Authors: Lips EH , de Graaf EJ , Tollenaar RAEM , van Eijk R , Oosting J , Szuhai K , Karsten T , Nanya Y , Ogawa S , van de Velde CJ , Eilers PHC , van Wezel Tom , Morreau H 
Published: April 2007

AbstractTotal mesorectal excision (TME) is the standard treatment for rectal cancer, while transanal endoscopic microsurgery (TEM) is a recently introduced surgical approach for the treatment of rectal adenomas. Incorrect preoperative staging before TEM is a problem. To identify genetic changes that might correlate with tumour stage and could lead to optimized treatment selection we performed a genome‐wide chromosomal instability search in a homogeneous, clinical cohort of rectal tumours. 78 rectal tumours during different clinical stages were analysed with 10K single nucleotide polymorphism (SNP) arrays. Logistic regression was performed to build a quantitative model of specific chromosomal aberrations. Overall, most cases (95%) had one or more chromosomal aberrations. We observed a clear correlation between the total number of aberrations and the different tumour stages. Specifically, the chromosomal events: gain of 8q22–24, 13q and 20q, and loss of 17p and 18q12–22, were far more abundant in carcinoma than in adenoma. In adenoma fractions from cases with a carcinoma (infiltrating at least in the submucosa), twice the amount of such ‘malignant aberrations’ was observed, compared to pure adenomas. Furthermore, combined aberrations such as gain of 13q and loss of 18q were only found in adenomatous fractions of carcinomas and not in benign lesions. Based on these five genomic events associated with carcinoma, a clear distinction between adenoma and carcinoma tissue could be made. These data should be validated further in order that they may be used in preoperative staging of rectal tumours. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Signet ring cell differentiation in mucinous colorectal carcinoma
Authors: Börger ME , Gosens MJEM , Jeuken JWM , van Kempen LCLT , van de Velde CJH , van Krieken JHJM , Nagtegaal ID 
Published: April 2007

AbstractApproximately 10% of all colorectal carcinomas are mucinous carcinomas, characterized by extracellular mucin. Occasionally, mucin accumulates intracellularly in these tumours, causing signet ring cell differentiation. We hypothesized that signet ring cells arise from a separate genetic pathway. In this study the molecular background of signet ring cell differentiation was investigated by analysing genetic changes, changes in the expression of adhesion molecules, and mucin content. Furthermore, its clinical relevance was addressed.Cell lines of colorectal tumours with non‐mucinous (AC), mucinous (MC), and signet ring cell phenotype (MCSRC) were used for Multiplex Ligation‐dependent Probe Amplification to detect deletions and amplifications in specific oncogenes and tumour suppressor genes. Furthermore, the expression of E‐cadherin, β‐catenin, ITF (intestinal trefoil factor), and MUC2 in signet ring cells was studied by immunohistochemistry, immunofluorescence, and mRNA in situ hybridization. Results were validated using a large cohort of rectal carcinomas from which clinicopathological data were available. Specific amplifications and deletions in cell lines of AC, MC, and MCSRC were detected. Bcl‐2 was amplified in MCSRC and MC cell lines, but not in AC cell lines. Bcl‐2 FISH analysis confirmed this in patient material.Signet ring cells had decreased expression of adhesion molecules (E‐cadherin, β‐catenin) and were strongly positive for ITF and MUC2, two peptides which are normally only produced by goblet cells. RNA in situ hybridization confirmed the production of ITF. Mucinous carcinomas with signet ring cell differentiation presented at a higher T stage than adenocarcinomas and mucinous carcinomas (16% pT4 versus 3‐5%, p < 0.001) and were more frequently node positive (77% vs 39–44%; p < 0.001). Prognosis was significantly worse. In conclusion, the presence of signet ring cells in carcinomas with mucinous differentiation correlates with increased T‐stage and poor prognosis. These cells, characterized by ITF and MUC2 production, show disruption of the E‐cadherin/β‐catenin complex, as well as amplification of Bcl‐2. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
ADAM 12 as a second‐trimester maternal serum marker in screening for Down syndrome
Authors: Christiansen Michael , Spencer Kevin , Laigaard Jennie , Cowans Nicholas J. , Larsen Severin Olesen , Wewer Ulla M. 
Published: April 2007

AbstractBackgroundADAM 12 is a placenta‐derived glycoprotein that is involved in growth and differentiation. The maternal serum concentration of ADAM 12 is a potential first‐trimester maternal serum marker of Down syndrome (DS). Here we examine the potential of ADAM 12 as a second‐trimester maternal serum marker of DS.Materials and MethodsThe concentration of ADAM 12 was determined in gestational week 14–19 in 88 DS pregnancies and 341 matched control pregnancies. Medians of normal pregnancies were established by polynomial regression and the distribution of log10 MoM ADAM 12 values in DS pregnancies and controls determined. Correlations with alpha‐fetoprotein (AFP) and free β‐human chorionic gonadotrophin (free β‐hCG) were established and used to model the performance of maternal serum screening with ADAM 12 in combination with other second‐trimester serum markers.ResultsThe ADAM 12 maternal serum concentration was significantly increased with a median MoM of 1.85 and a mean log10 MoM (SD) of 0.268 (0.2678) compared to a mean log10 MoM (SD) of 0.013 (0.4318) in controls. ADAM 12 correlated with maternal weight and ethnicity (with the serum concentration increased in Afro‐Caribbeans), but neither with maternal age nor gestational age, and only marginally with AFP (r(DS) = 0.078, r(controls) = 0.093) and free β‐hCG (r(DS) = 0.073, r(controls) = 0.144. The increase in detection rate—for a false positive rate of 5%—by adding ADAM 12 to the double test (AFP + free β‐hCG) was 4%, similar to that of adding uE3 to the double test.ConclusionADAM 12 is an efficient second‐trimester marker for DS. Further studies should be conducted to determine whether it may be a useful additonal or alternative marker to those currently used in the second‐trimester. Copyright © 2007 John Wiley & Sons, Ltd.
Noticeable viscosity reduction of polycarbonate melts caused jointly by nano‐silica filling and TLCP fibrillation
Authors: Wu Li‐Chuan , Chen Peng , Chen Jun , Zhang Jun , He Jia‐Song 
Published: April 2007

AbstractNano‐SiO2 was introduced into in‐situ composites of polycarbonate (PC) and a thermotropic liquid crystalline polymer (TLCP) using a twin‐screw extruder. The rheology of these composites was characterized with capillary rheometry, and the morphology of the dispersed TLCP observed with scanning electron microscopy. The rheological data revealed that the viscosity decrease of PC melts by only the addition up to 20 wt% TLCP remained smaller than 30%, while it became ∼48% upon further addition of only about 1 wt% nano‐SiO2 and larger than 60% upon ∼9 wt% nano‐SiO2 filling, in contrast to a 50% viscosity increase of PC melts with increase in nanosilica loading up to ∼9 wt%. These silica‐filled composites exhibited markedly low viscosity, especially at relatively high shear rates. The morphology of TLCP extracted from unfilled and silica‐filled composites indicated that the largest viscosity reduction was correlated well with the fibrillation of TLCP droplets enhanced by nano‐SiO2. The TLCP/SiO2/PC composites exhibited rheological hybrid effect with fillers at nanometer scale. POLYM. ENG. SCI., 47:757–764, 2007. © 2007 Society of Plastics Engineers
Spatial orientation of nanoclay and crystallite in microcellular injection molded polyamide‐6 nanocomposites
Authors: Yuan Mingjun , Song Qing , Turng Lih‐Sheng 
Published: April 2007

AbstractThree different types of characteristic structures‐microcells, nanoclay, and crystallite lamella‐exist in injection molded polyamide‐6 microcellular nanocomposites. These structures are in completely different scales. The spatial orientation of these microscale structures crucially determines the material's bulk properties. Based on scanning electron microscopy, transmission electron microscopy, and two‐dimensional X‐ray diffractometry measurements, it was found that the nanoclay and the crystallite formed special geometric structures around the microcells and near the part skins. The nanoclay platelets lay almost parallel to the surfaces of the molded parts. Preferred orientation of the crystallites was induced by the presence of the nanoclay. A molecular‐based model is proposed to describe the structural hierarchy and correlations among the microcells, nanoclay, and crystallite lamella. From the small‐angle X‐ray scattering experiments, it was found that microcellular injection molding produces relatively smaller crystallite lamella than that of conventional injection molding, and that for both solid and microcellular neat resin parts the crystallite lamella thickness at the part skin is smaller than that at the core. Polarized optical microscopy results also indicated that the size of crystallites in the microcellular neat resin and nanocomposite parts is smaller than that in the corresponding solid parts. POLYM. ENG. SCI., 47:765–779, 2007. © 2007 Society of Plastics Engineers
Optimization and scale‐up of starch cationization in a twin screw extruder
Authors: Berzin F. , Tara A. , Vergnes B. 
Published: April 2007

AbstractIn a previous work, a theoretical model for the cationization of wheat starch in a modular self‐wiping corotating twin screw extruder has been developed and experimentally validated. Our objective in the present article was to use this model in a first step to optimize the cationization reaction on a laboratory scale extruder, and, in a second step, to extrapolate the results to an industrial scale extruder. We will show that the use of a theoretical model of reactive extrusion allowed us to define screw profiles and processing conditions according to the end‐use properties of the desired product and the limits of the process. Based on the performances obtained at laboratory scale, it permitted also to predict the performances of an industrial production line. POLYM. ENG. SCI., 47:814–823, 2007. © 2007 Society of Plastics Engineers
Injection molding quality control by integrating weight feedback into a cascade closed‐loop control system
Authors: Chen Zhongbao , Turng Lih‐Sheng 
Published: April 2007

AbstractQuality control plays a crucial role in injection molding control to meet stringent tolerance requirements and to facilitate automation. Previous work has tackled this challenging subject mainly through consistent machine operations or process variable control. In this paper, a direct quality feedback control system has been proposed and developed. The system has a cascade structure and combines both feedback and feedforward controls. An important quality index, namely, part weight, is measured in each molding cycle. The difference between this measurement and a quality target is used to adjust the mold separation at the process level. The mold separation is controlled via both a cycle‐to‐cycle mass‐based switchover point and a within‐cycle holding pressure control. Molding experiments have been conducted using different mold geometries and resins. Compared with the cavity pressure based control system currently used in industry, the control system in this study results in a significant improvement of both long‐term and short‐term consistencies in part quality. In addition, this direct quality feedback control has other benefits, such as 100% quality inspection and automatic process tuning. POLYM. ENG. SCI., 47:852–862, 2007. © 2007 Society of Plastics Engineers
Influence of the amount of salts of rosin acid on the nonisothermal crystallization, morphology, and properties of isotactic polypropylene
Authors: Wang Jingbo , Dou Qiang , Wu Shishan , Chen Xianyi 
Published: April 2007

AbstractThe nonisothermal crystallization of Isotactic polypropylene (iPP) containing different concentration of nucleating agent potassium dehydroabietate (DHAA‐K) or sodium dehydroabietate (DHAA‐Na) at the cooling rate of 10°C/min was investigated using differential scanning calorimetry (DSC) together with Jeziorny's method. It was found that the temperature at which the maximum rate of crystallization occurred shifted to a higher region by about 13.7–16.9°C, and the rate of crystallization became faster for iPP with DHAA‐K (PPK) or DHAA‐Na (PPNa) in comparison to the virgin iPP. Avrami exponent for virgin PP, PPK, and PPNa was about 3.1, 2.2, and 2.2, respectively, suggesting the change of the crystal growth mechanism of iPP with the addition of the nucleating agents. The morphology of iPP with and without nucleating agent examined by a cross polarized light microscope indicated that the size of spherulites marginally decreased, which then remained stable with the increase of the concentration of DHAA‐K or DHAA‐Na. The measurements of the optical and mechanical properties of iPP showed that the transparency, gloss, and flexural modulus increased with increasing nucleating agent before its optimal concentration. POLYM. ENG. SCI., 47:889–897, 2007. © 2007 Society of Plastics Engineers
Effect of melt annealing on the phase structure and rheological behavior of propylene–ethylene copolymers
Authors: De La Torre Vanesa , Fris Jorge A. Rodríguez , Failla Marcelo D. , Quinzani Lidia M. 
Published: April 2007

AbstractThe morphological and rheological properties of a commercial propylene‐ethylene copolymer (PEC) and a series of blends with different concentrations of poly (ethylene‐co‐propylene) are investigated. The blends are prepared mixing PEC with fractions obtained from it by solvent extraction. The phase structure of samples exposed to different thermal and mechanical histories was analyzed using scanning electron microscopy. The linear viscoelastic properties of the molten polymers were measured using different test sequences that include dynamic frequency and time sweeps. The phase structure of most blends changes dramatically with time when the polymers are kept in the molten state due to the coalescence of the domains. For example, the initial morphology of PEC which presents domains of ∼1 μm diameter changes to regions of more than 10 μm of average diameter after 90 min at 178°C at rest. Coincidentally, the dynamic moduli of the blends change during annealing reaching values that depend on the mechanical history. For example, the elastic modulus of PEC increases ∼32% during a dynamic time sweep of 45 min using a frequency of 0.1 s−1, while it decreases ∼18% when a frequency of 1 s−1 is applied. Moreover, the modulus measured at 0.1 s−1 of samples annealed at rest during 45 min is ∼58% larger than that of the fresh material. POLYM. ENG. SCI., 47:912–921, 2007. © 2007 Society of Plastics Engineers
Structure and properties of in situ compatibilized polystyrene/polyolefin elastomer blends
Authors: Guo Zhenghong , Tong Lifang , Xu Zhongbin , Fang Zhengping 
Published: April 2007

AbstractTo increase the compatibility of polystyrene (PS) and polyolefin elastomer (POE) blends, a Lewis acid catalyst, aluminum chloride (AlCl3), was adopted to initiate the Friedel–Crafts alkylation reaction for the formation of PS‐graft‐POE copolymer. Dynamic mechanical analysis indicated that PS/POE and PS/POE/AlCl3 blends are partially miscible, and the formation of PS‐graft‐POE copolymer increased the compatibility between PS and POE. Scanning electron microscope and transmission electron microscope results showed that the domain size of the blends decreased dramatically and the size distribution became more uniform with the addition of AlCl3. Such in situ compatibilization also induced hindrance to the macromolecular chain movement, as reflected by the results of the dynamic rheological analysis. The dynamic rheological behaviors of PS/POE and PS/POE/AlCl3 blends under different temperature showed that in situ compatibilization weakened the effects of thermooxidation on PS/POE blends. Moreover, in situ compatibilization decreased the activation energy of viscous flow and reduced the influence of temperature on PS/POE blends. POLYM. ENG. SCI., 47:951–959, 2007. © 2007 Society of Plastics Engineers
Effects of dam removal on brook trout in a Wisconsin stream
Authors: Stanley Emily H. , Catalano Matt J. , Mercado‐Silva Norman , Orr Cailin H. 
Published: April 2007

AbstractDams create barriers to fish migration and dispersal in drainage basins, and the removal of dams is often viewed as a means of increasing habitat availability and restoring migratory routes of several fish species. However, these barriers can also isolate and protect native taxa from aggressive downstream invaders. We examined fish community composition two years prior to and two years after the removal of a pair of low‐head dams from Boulder Creek, Wisconsin, U.S.A. in 2003 to determine if removal of these potential barriers affected the resident population of native brook trout (Salvelinus fontinalis). Despite the presence of other taxa in the downstream reaches, and in other similar streams adjacent to the Boulder Creek (including the brown trout, Salmo trutta), no new species had colonized the Boulder Creek in the two years following dam removal. The adults catch per unit effort (CPUE) was lower and the young‐of‐the‐year catch per unit effort (YOY CPUE) was higher in 2005 than in 2001 in all reaches, but the magnitude of these changes was substantially larger in the two dam‐affected sample reaches relative to an upstream reference reach, indicating a localized effect of the removal. Total length of the adults and the YOY and the adult body condition did not vary between years or among reaches. Thus, despite changes in numbers of adults and the YOYs in some sections of the stream, the lack of new fish species invading Boulder Creek and the limited extent of population change in brook trout indicate that dam removal had a minor effect on these native salmonids in the first two years of the post‐removal. Copyright © 2007 John Wiley & Sons, Ltd.
Comparative characterisation by atomic force microscopy and ellipsometry of soft and solid thin films
Authors: Mykhaylyk T. A. , Dmitruk N. L. , Evans S. D. , Hamley I. W. , Henderson J. R. 
Published: April 2007

AbstractEllipsometry and atomic force microscopy (AFM) were used to study the film thickness and the surface roughness of both ‘soft’ and solid thin films. ‘Soft’ polymer thin films of polystyrene and poly(styrene–ethylene/butylene–styrene) block copolymer were prepared by spin‐coating onto planar silicon wafers. Ellipsometric parameters were fitted by the Cauchy approach using a two‐layer model with planar boundaries between the layers. The smooth surfaces of the prepared polymer films were confirmed by AFM. There is good agreement between AFM and ellipsometry in the 80–130 nm thickness range. Semiconductor surfaces (Si) obtained by anisotropic chemical etching were investigated as an example of a randomly rough surface. To define roughness parameters by ellipsometry, the top rough layers were treated as thin films according to the Bruggeman effective medium approximation (BEMA). Surface roughness values measured by AFM and ellipsometry show the same tendency of increasing roughness with increased etching time, although AFM results depend on the used window size. The combined use of both methods appears to offer the most comprehensive route to quantitative surface roughness characterisation of solid films. Copyright © 2007 John Wiley & Sons, Ltd.
Analysis of cluster ion sputtering yields: correlation with the thermal spike model and implications for static secondary ion mass spectrometry
Authors: Seah M. P. 
Published: April 2007

AbstractAn assessment is made of the behaviours in ion sputtering and static secondary ion mass spectrometry to provide a framework to understand the enhanced secondary ion yield of molecular fragments, from molecules on defined substrates, achieved by using primary ion clusters. First, an analysis is made of the published ion sputtering yield data for mono‐elemental solids sputtered by mono‐elemental primary ion clusters, mainly of the type Aun+. These are evaluated using Sigmund and Claussen's thermal spike model. That theory is shown to be consistent with, and an excellent description of, the published ion sputtering yields for elemental targets over a wide energy range for primary ion cluster sizes from 1 to 13 for gold primary ion clusters and for a number of different primary ion species. This theory is then used to evaluate the molecular ion yield behaviour of interest in static secondary ion mass spectrometry (SIMS). This is done for measurements on Irganox 1010. The thermal spike sputtering yield is first related to the total secondary ion yield. The secondary ion yield of the molecular ion, whether protonated or de‐protonated, is then shown to be proportional to the square of the total secondary ion yield and hence to the square of the sputtering yield. This rule is valid for all primary ions, both single atom and cluster, over 5 decades of emission intensity, largely independent of the chemical identity of the primary ions for those data. This enables recommendations for future sources of higher efficiency for the analysis of organic materials. © Crown copyright 2007. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.