bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identifying star clusters in a field: A comparison of different algorithms
Authors: Schmeja S. 
Published: February 2011

AbstractStar clusters are often hard to find, as they may lie in a dense field of background objects or, because in the case of embedded clusters, they are surrounded by a more dispersed population of young stars. This paper discusses four algorithms that have been developed to identify clusters as stellar density enhancements in a field, namely stellar density maps from star counts, the nearest neighbour method and the Voronoi tessellation, and the separation of minimum spanning trees. These methods are tested and compared to each other by applying them to artificial clusters of different sizes and morphologies. While distinct centrally concentrated clusters are detected by all methods, clusters with low overdensity or highly hierarchical structure are only reliably detected by methods with inherent smoothing (star counts and nearest neighbour method). Furthermore, the algorithms differ strongly in computation time and additional parameters they provide. Therefore, the method to choose primarily depends on the size and character of the investigated area and the purpose of the study (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparisons of u ‐, g ‐, r ‐, i ‐, and z ‐band luminosity distributions between galaxy members of compact groups and isolated galaxies
Authors: Deng X.‐F. , Zou S.‐Y. 
Published: February 2011

AbstractTo investigate the environmental dependence of u ‐, g ‐, r ‐, i ‐, and z ‐band luminosities, we perform comparative studies of luminosity distributions between galaxy members of compact groups (CGs) and isolated galaxies. It is found that for the r, i, and z bands isolated galaxies have a higher proportion of faint galaxies and a lower proportion of luminous galaxies than galaxy members of CGs, but for the u band an opposite trend is observed. The correlation between the g ‐band luminosity and the environment has different trends in different luminosity regions (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical multiband surface photometry of a sample of Seyfert galaxies: III. Global, isophotal, and bar parameters
Authors: Slavcheva‐Mihova L. , Mihov B. 
Published: February 2011

AbstractThis paper is third in a series, studying the optical properties of a sample of Seyfert galaxies. Here we present a homoge neous set of global (ellipticity, position angle, inclination, and total magnitude) and isophotal (semi‐major axis and colour indices at 24V mag arcsec–2) parameters of the galaxy sample. We find the following median corrected isophotal colour indices: (B – IC)(0)24 = 1.9 mag arcsec–2 and (V – IC)(0)24 = 1.1 mag arcsec–2. A set of bar parameters (ellipticity, position angle, semi‐major axis corresponding to the ellipticity maximum in the bar region, and length) are also reported; deprojection has been applied to the bar ellipticity, length, and relative length in terms of galaxy isophotal semi‐major axis. Regarding bar length estimation, we use a method, based on the relation between the behaviour of the profiles and orbit analysis. The so estimated bar length tightly correlates with the semi‐major axis, corresponding to the ellipticity maximum with a median ratio of the former to the latter of 1.22. The median of the deprojected bar ellipticity, length, and relative length are 0.39, 5.44 kpc, and 0.44, respectively. There is a correlation between the deprojected bar length and the corrected isophotal semi‐major axis at 24V mag arcsec–2. Three of the 17 large‐scale bars appear strong, based on the deprojected bar ellipticity as a first‐order approximation of bar strength. The deprojected relative bar length does not appear to correlate with the bar ellipticity (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Strömgren Hβ ‐photometry of stars in dark clouds
Authors: Piehl D. , Briley M. , Kaltcheva N. 
Published: February 2011

AbstractWe present uvbyβ photometry of 64 stars in 6 small dark clouds. From the photometry we infer approximate spectral types of the observed stars and derive distances and color excesses for each of them. We further derive new distance estimates to some of the globules based on the distances of individual stars possibly included in their peripheries. For clouds where sufficient target stars are available (CB3, CB52, and CB54), a clear trend of increasing linear polarization (as measured by Sen et al. 2000) with extinction is observed. We also find excellent correlation between polarization and extinction for the entire sample. The location of the stars on the polarization‐extinction diagram is consistent with that for field stars found by Serkowski et al. (1975). The relation between polarization and extinction evident for the stars of our sample suggests perfect grain alignment and constant grain properties along each line of sight (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Meckel's diverticulum: A review
Authors: Uppal Kiranjit , Shane Tubbs R. , Matusz Petru , Shaffer Kitt , Loukas Marios 
Published: February 2011

AbstractMeckel's diverticulum is the most prevalent congenital abnormality of the gastrointestinal tract. This anomaly is due to the incomplete obliteration ofthe omphalomesenteric duct during the 7th week of gestation and is classically located 2 feet proximal to the ileocecal valve. Variations of this congenital malformation have been recorded based on location, size, and form. While most of the population may be asymptomatic, clinical manifestation, including gastrointestinal bleed and intestinal obstruction, can emerge. Despite the frequency of Meckel's diverticulum, it is commonly misdiagnosed due to its mimicry of appendicitis. This article aimed to review this derailment of embryological development. Clin. Anat. 24:416–422, 2011. © 2011 Wiley‐Liss, Inc
Obturator hernia: Anatomy, embryology, diagnosis, and treatment
Authors: Petrie Alison , Shane Tubbs R. , Matusz Petru , Shaffer Kitt , Loukas Marios 
Published: February 2011

AbstractAn obturator hernia is an infrequent but significant cause of intestinal obstruction. The incidence of obturator hernias is between 0.05 and 1.4% of all hernias. The mortality rate can be as high as 70% when acutely incarcerated due to the difficulty in diagnosis and delay in surgical treatment Three progressive stages of obturator herniation have been classified and can be one of three different varieties depending on the pathway the herniated sac follows. Knowledge of the anatomy and pathogenesis of obturator herniation is essential in diagnosis and treatment. The most common clinical presentation is intestinal obstruction (90%) and this is often seen in elderly, emaciated, multiparous women with predisposing conditions. Other classic signs, though not always present include obturator neuralgia, the Howship‐Romberg sign and the Hannington‐Kiff sign. Computed tomography scan is the most favored diagnostic imaging method. The abdominal surgical approach is most preferred when a diagnosis is uncertain and laparoscopy should be employed in elective early surgeries. This aim of this article is to review the diagnosis and treatment of obturator hernia by describing the anatomy, embryology, clinical presentation, diagnosis, and management currently in use. Increased awareness and proper management of this condition will result in decreased morbidity and mortality. Clin. Anat. 24:562–569, 2011. © 2011 Wiley‐Liss, Inc.
The role of the anatomy of the sigmoid colon in developing sigmoid volvulus: A case–control study
Authors: Akinkuotu Adesola , Samuel Jonathan C. , Msiska Nelson , Mvula Chimwemwe , Charles Anthony G. 
Published: February 2011

AbstractSigmoid volvulus is a common condition throughout much of the world. To this date, there are no adequately controlled clinical trials examining the role of anatomy in sigmoid volvulus. Therefore, the objective of this study was to determine if the anatomic dimensions of the sigmoid colon differ in sigmoid volvulus compared to controls. This prospective case–control study was conducted at Kamuzu Central Hospital, Lilongwe, Malawi. Cases included individuals 18 years or older with surgically confirmed sigmoid volvulus, while controls included individuals undergoing surgery for reasons unrelated to the descending or sigmoid colon, or rectum. Intraoperative measurements of the sigmoid colon were taken, including mesosigmoid root width and mesosigmoid length. A total of 26 cases and 12 controls were enrolled. When compared to controls, the mesosigmoid of cases had a greater length and maximal width; however, mesosigmoid root width was similar between groups. These findings support the assertion that sigmoid volvulus is due to a long and wide mesosigmoid that rotates on a constant mesosigmoid root width. This is the first adequately controlled trial examining anatomy in sigmoid volvulus and provides strong evidence that refines prior hypotheses regarding the anatomic basis of sigmoid volvulus. Clin. Anat. 24:634–637, 2011. © 2011 Wiley‐Liss, Inc.
Structure–Function Relationships of Phenoxazine Nucleosides for Identification of Mismatches in Duplex DNA by Fluorescence Spectroscopy
Authors: Gardarsson Haraldur , Kale Ajaykumar S. , Sigurdsson Snorri Th. 
Published: February 2011

AbstractThe effects of the flanking sequence on the mismatch‐detection capabilities of the fluorescent nucleoside phenoxazine (tCO) were examined in a systematic fashion, and compared to the previously reported fluorescent, phenoxazine‐based nucleoside Çf. We see some similarities for the two fluorescent nucleosides, for example, the emission intensity of the C‐mismatched duplex is always the highest, and a three‐peak pattern in the spectrum emerges when the fluorosides are base‐paired with A. However, phenoxazine was only able to distinguish a mismatch from the fully base‐paired duplex in 11 out of 16 flanking sequences, and was able to identify each of the mismatches in six of those sequences. Therefore, tCO shows poorer discrimination of mismatches than was previously reported for Çf, which could be used to identify all base‐pairing partners in all immediately flanking sequences, albeit in some cases by using mercuric ions to selectively quench the emission of the T‐mismatched duplex. The mercuric titration might resolve the overlap of fluorescence curves of tCO in some flanking sequences, but not for 5′‐d(CtCOG) and 5′‐d(TtCOA) due to overlap of A‐mismatch and G‐match fluorescence curves. A pH titration was performed on Çf, tCO and a N5‐methylated derivative of tCO, which showed that the emergence of the three‐peak pattern is associated with the de‐protonation of N5 in the fluorosides. We also show that neither the α‐ nor β‐anomer of the phenothiazine nucleoside (tC) was able to detect a mismatch in any of the flanking sequences examined.
High Transfection Efficiency of Cationic Lipids with Asymmetric Acyl–Cholesteryl Hydrophobic Tails
Authors: Radchatawedchakoon Widchaya , Krajarng Aungkana , Niyomtham Nattisa , Watanapokasin Ramida , Yingyongnarongkul Boon‐ek 
Published: February 2011

AbstractThe ability of a nonviral gene delivery system to overcome extra‐ and intracellular barriers is a critical issue for the future clinical applications of gene therapy. In recent years much effort has been focused on the development of a variety of DNA carriers, and cationic liposomes have become the most common nonviral gene delivery system. One hundred and eighty novel cationic lipids with asymmetric acyl–cholesteryl hydrophobic tails were synthesized by parallel solid‐phase chemistry. The liposomes were prepared and gel retardation assays were used to study the binding efficiency between the prepared liposome and the DNA. Transfection efficiencies of the lipids were evaluated against various mammalian cells, such as human embryonic kidney (HEK293), human cervical adenocarcinoma (HeLa), canine osteosarcoma (D17), colorectal adenocarcinoma (COLO 205), and human prostate adenocarcinoma (PC3) cells. The lipids with an acyl portion at the terminal part of the polyamine backbone exhibited higher transfection efficiency than those with the acyl portion as an internal part of the backbone. These compounds also showed higher transfection efficiency and lower cytotoxicity than the commercially available agents, Effectene, DOTAP, and DC‐Chol.
Phthalocyanine Analogues: Unexpectedly Facile Access to Non‐Peripherally Substituted Octaalkyl Tetrabenzotriazaporphyrins, Tetrabenzodiazaporphyrins, Tetrabenzomonoazaporphyrins and Tetrabenzoporphyrins
Authors: Cammidge Andrew N. , Chambrier Isabelle , Cook Michael J. , Hughes David L. , Rahman Muhibur , Sosa‐Vargas Lydia 
Published: February 2011

AbstractControlled syntheses of phthalocyanine/benzoporphyrin hybrid structures have been achieved. We report a simple means for obtaining non‐peripherally octaalkyl‐substituted derivatives of tetrabenzotriazaporphyrin (TBTAP), tetrabenzodiazaporphyrin (TBDAP), tetrabenzomonoazaporphyrin (TBMAP) and tetrabenzoporphyrin (TBP) macrocycles by treating 3,6‐dialkyl phthalonitriles with differing amounts of the Grignard reagent MeMgBr. This range of macrocyclic products is not obtained from corresponding reactions of a Grignard reagent with 4‐substituted phthalonitriles, reported previously, or reaction of MeMgBr with a 4,5‐dialkyl phthalonitrile. Attempts to form a meso‐substituted TBTAP from 3,6‐dialkyl phthalonitriles by reaction with benzyl and long‐chain alkyl Grignard reagents unexpectedly gave only the parent macrocycle unsubstituted at the meso position. The synthetic protocols are by far the most straightforward and convenient means to access these interesting, but scarcely studied, classes of material. The new series of substituted macrocyclic compounds, obtained as the metal‐free and magnesium‐ and copper(II)‐metallated derivatives, show trends in the UV/Vis spectra consistent with those predicted elsewhere by Kobayashi. Characterisation of the new families allows further trends to be identified as meso‐nitrogen atoms are sequentially replaced by methine bridges, for example, the compounds provide novel examples of macrocyclic structures that show columnar mesophase behaviour. Single‐crystal X‐ray structure determinations have been obtained for three magnesium‐metallated derivatives bearing eight hexyl substituents and constitute the first set of structural data obtained for such a series.
The Scope of Ambiphilic Acetate‐Assisted Cyclometallation with Half‐Sandwich Complexes of Iridium, Rhodium and Ruthenium
Authors: Boutadla Youcef , Davies David L. , Jones Rachel C. , Singh Kuldip 
Published: February 2011

AbstractCH activation by acetate‐assisted cyclometallation of a phenyl group with half‐sandwich complexes [{MCl2Cp*}2] (M=Ir, Rh) and [{RuCl2(p‐cymene)}2] can be directed by a wide range of nitrogen donor ligands including pyrazole, oxazoline, oxime, imidazole and triazole, and X‐ray structures of a number of complexes are reported. All the ligands tested cyclometallated at iridium, however ruthenium and rhodium fail to cause cyclometallation in some cases. As a result, the nitrogen donors have been categorised based on their reactivity with the three metals used. The relevance of these cyclometallation reactions to catalytic synthesis of carbocycles and heterocycles is discussed.
Synthesis, Characterisation and Cytotoxicity of Polyoxometalate/Carboxymethyl Chitosan Nanocomposites
Authors: Geisberger Georg , Paulus Susann , Carraro Mauro , Bonchio Marcella , Patzke Greta R. 
Published: February 2011

AbstractChitosan and its derivates continue to attract considerable research interest as effective drug carriers with good biocompatibility and high cellular uptake rates. We used these versatile features to tap the considerable biomedical potential of polyoxometalates (POMs) through their encapsulation into a carboxymethyl chitosan (CMC) matrix. The nanocapsules were prepared by ionic gelification with Ca2+; their size distribution ranges from 60 to 150 nm. Because [Co4(H2O)2(PW9O34)2]10− is well known for its manifold properties, such as antiviral activity, it was selected as a model POM. The resulting composites were characterised with a wide range of analytical methods, which pointed to quantitative encapsulation of intact POMs within the CMC matrix. We studied the biocompatibility of the POM/CMC nanocomposites on HeLa cells through MTT and proliferation assays. Even after prolonged incubation times at high concentrations, the composites did not display cytotoxicity, thereby drastically reducing the side effects of the pristine POMs. This opens up new avenues for designing novel inorganic drug prototypes from bioactive POMs.
Synthesis and Biological Evaluation of 6‐Substituted 5‐Alkyl‐2‐(phenylaminocarbonylmethylthio)pyrimidin‐4(3H)‐ones as Potent HIV‐1 NNRTIs
Authors: Yu Mingyan , Li Zhenyu , Liu Shuai , Fan Erkang , Pannecouque Christophe , De Clercq Erik , Liu Xinyong 
Published: February 2011

AbstractA series of new 5‐alkyl‐2‐phenylaminocarbonylmethylthiopyrimidin‐4(3H)‐ones bearing variously substituted arylmethyl moieties at the C6 position of the pyrimidine ring were synthesized and evaluated for anti‐HIV activity in MT‐4 cells. Most of these new congeners exhibited moderate to good activities against the wild‐type virus, with EC50 values in the range of 1.40–0.19 μM. Among them, 2‐[(4‐cyanophenylamino)carbonylmethylthio]‐6‐(2‐chloro‐6‐fluorobenzyl)‐5‐ethylpyrimidin‐4(3H)‐one 4 b6 is one of the compounds endowed with the highest broad‐spectrum HIV‐1 inhibitory activity, with EC50 values of 0.19±0.005 μM against the wild‐type virus, 1.05±0.24 μM (twofold resistance) against the E138K strain, and 2.38±0.13 μM (4.5‐fold resistance) against the Y181C strain. Furthermore, reverse transcriptase (RT) inhibition assays against wild‐type HIV‐1 RT were performed with selected derivatives, confirming that the main target of these compounds is HIV‐1 RT and that these new S‐DABO analogues act as non‐nucleoside RT inhibitors (NNRTIs). Structure–activity relationship and molecular modeling analyses of these new congeners are also discussed.
Stretched Polyethylene Films Probed by Single Molecules
Authors: Wirtz Alexander C. , Hofmann Clemens , Groenen Edgar J. J. 
Published: February 2011

AbstractStretched films of low‐density polyethylene (LDPE) doped with 2.3,8.9‐dibenzanthanthrene (DBATT) were studied using polarization‐selective single‐molecule spectroscopy at 1.8 K. By measuring the in‐plane component of the electronic transition‐dipole moments of individual chromophores, the alignment of dopant molecules is determined without averaging. The distributions of chromophore orientations reveal the presence of two fractions of dopant molecules: those oriented along the stretching direction and randomly oriented molecules. With increasing drawing ratio of the polyethylene films, the ratio of oriented to randomly oriented guest molecules increases, whereas the extent of chromophore orientation, that is, the width of the orientation distribution, remains the same. The results are consistent with the interpretation that oriented chromophores reside on the surfaces of polyethylene crystals, instead of in the amorphous polyethylene regions. Guest molecules in stretched polyethylene are oriented due to the alignment of the crystallites on which they are adsorbed. As such, the shape and width of the distributions of chromophore orientations are determined by the interaction of guest molecules with the crystal surfaces.
Cytological features of myxomatous fibroadenoma of the breast
Authors: Yamaguchi Rin , Tanaka Maki , Yokoyama Toshiro , Nonaka Yasuhide , Mizushima Yasuko , Kawahara Akihiko , Yoshida Tomoko , Ito Tsutomu , Yamaguchi Miki , Kage Masayoshi , Yano Hirohisa 
Published: February 2011

AbstractFibroadenoma (FA) is a benign tumor that must be differentiated from carcinomas. FAs often exhibit myxedematous changes (myxomatous FA, M‐FA). We previously reported on the clinical significance of M‐FA. M‐FA and (mucinous) carcinoma share clinical findings, rapid growth and a relatively large size, a high‐depth/width (D/W) ratio, a relatively round shape, and posterior echo enhancement with internal hyperechogenicity on ultrasonography (US). Next, a biopsy is required for differential diagnosis. In this study, we evaluated the diagnostic significance of the cytological findings of M‐FA with US findings. Among 13 FAs that were diagnosed by cytology, we compared (i) a group of six mucinous carcinomas with acellular mucin and a D/W ratio ≥ 0.7 (a suspicious factor for malignancy) with a group with a D/W ratio of <0.7, and (ii) the frequency of metachromasia on Giemsa stain between M‐FAs and non‐M‐FAs among eight FA cases confirmed by histology. (i) FA lesions (7 of 13) showed metachromasia with Giemsa staining significantly more frequently than did mucinous carcinoma (0/6) (Fisher's exact test, P < 0.044). FA lesions with a D/W ratio ≥ 0.7 (6/7) showed metachromasia significantly more frequently than did FA with a D/W ratio <0.7 (1/6) (Fisher's exact test, P < 0.029). Among eight FA cases confirmed by histology, M‐FA cases (6/6) demonstrated metachromasia significantly more frequently than non‐M‐FA cases (0/2) (P < 0.036). M‐FA cytologically exhibits marked metachromasia on Giemsa staining. Combining cytological examination and understanding the clinical features of M‐FA may allow us to choose cytological examination as a first‐line diagnostic method for tumor‐forming lesions. Diagn. Cytopathol. 2011. © 2011 Wiley‐Liss, Inc.
Cholangiocarcinoma in a 17‐year‐old boy with primary sclerosing cholangitis and UroVysion™ fluorescent in situ hybridization
Authors: Huddleston Brent J. , Lamb Randy D. , Gopez Evelyn V. , Adler Douglas G. , Collins Brian T. 
Published: February 2011

AbstractPrimary sclerosing cholangitis (PSC) is uncommon in the younger age range and bile duct brushing cytology can present unique challenges. We describe the case of a 17‐year‐old boy with a new diagnosis of PSC who presented with cholangiocarcinoma. The clinical history, endoscopic features, cytomorphologic findings, and results of UroVysion™ fluorescent in situ hybridization (FISH) on the bile duct brush are described. UroVysion FISH on bile duct brushings is an ancillary study that can improve the diagnostic sensitivity for malignancy, specially in challenging cases where the cytomorphologic or clinical characteristics of the case are not typical. The occurrence of cholangiocarcinoma in young age group with PSC is uncommon, and the utilization of UroVysion FISH has been rarely described. Diagn. Cytopathol.2011; © 2011 Wiley‐Liss, Inc.
Fine‐needle aspiration of ganglioneuroma, maturing type (a.k.a., “borderline ganglioneuroblastoma”) in the mediastinum of a young man: Case report and discussion of classification
Authors: Ponsford Tipps Ann M. , Weidner Noel 
Published: February 2011

AbstractWe report a very unusual case of a posterior mediastinal tumor in a young man, which we diagnosed by fine‐needle aspiration cytology as most consistent with ganglioneuroma, maturing subtype. The cytopathologic features were interpreted using the classification of neuroblastic tumors as defined by the International Neuroblastoma Pathology Committee. Neuroblastic tumors are peculiar tumors that have capacity for maturation, and hence they present as a spectrum of tumors, ranging from the undifferentiated neuroblastoma, to ganglioneuroblastoma, to the mature version ganglioneuroma. The practicing surgical pathologist or cytopathologist who does not regularly encounter pediatric specimens may experience difficulty interpreting a specimen from one of these tumors. The following case report discusses application of these criteria to cytopathologic diagnosis of these tumors. Diagn. Cytopathol. 2012. © 2011 Wiley Periodicals, Inc.