bluuebunny/crossref_metadata_2025_split huggingface dataset:
Two New Cerebrosides and Anthraquinone Derivatives from the Marine Fungus Aspergillus niger
Authors: WU Zu‐Jian , OUYANG Ming‐An , SU Ren‐Kuan , GUO Yue‐Xiong 
Published: April 2008

AbstractTwo new cerebrosides, asperiamide B (1) and C (2), and two known aflatoxins, averufin and nidurufin, have been isolated from a Quanzhou marine fungus Aspergillus niger (MF‐16), and the structures were elucidated by spectroscopic data and chemical means. Among the compounds 5 and 6 showed moderate activities in inhibiting multiplication of the Tobacco Mosaic Virus (TMV).
Synthesis of TiO2/Poly(styrene‐co‐divinybenzene) Nanocomposite Microspheres by Grafting Copolymerization
Authors: LI Sen , WANG Kuan , CHENG Jiang , WEN Xiu‐Fang , PI Pi‐Hui , YANG Zhuo‐Ru , LI Zhi‐Ying 
Published: April 2008

AbstractPorous and nonporous nanocomposite microspheres were successfully prepared by grafting titania (TiO2) particles to poly(styrene‐co‐divinylbenzene) microsphere involving silane coupling agent 3‐glycidoxypropyltri‐methoxysilane (KH560), styrene and maleic anhydride as coupling agents. The effects of KH560 and styrene on the dispersion and amount of grafted‐titania on the surface of the microsphere (nonporous) as well as the effect of porous property of the supporting microsphere on the amount of grafted‐TiO2 within the microsphere (porous) were investigated. The results indicated that both KH560 and styrene could enhance the stability and dispersion of TiO2 particles attached to the surface of the microsphere producing grain size with diameter in the range of 30–80 nm. With nonporous microsphere styrene also increased the amount of grafted‐TiO2 particles on the microsphere from 10.4% to 20.4% as revealed by TGA. Porous nanocomposite microspheres with mean pore size of 136 nm could accommodate more TiO2 particles larger than either nonporous nanocomposite or porous nancomposite with mean pore size of 31 nm, yielding maximum of 26% by weight of grafted‐TiO2.
Strength of C–H Bonds at Nitrogen α ‐Position:Implication for Metabolic Stability of Nitrogen‐containing Drug Molecules
Authors: MENG Xiang‐Ming , ZOU Lu‐Feng , XIE Miao , FU Yao 
Published: April 2008

AbstractThe available experimental αC‐H BDEs of a variety of amine‐containing molecules were examined by using the G3B3 and CBS‐Q methods. The verified values were employed to benchmark and calibrate the density functional theory methods. It was found that the (U)BHandH/6‐311++G(2df, 2p)//(U)B3LYP/6‐31G(d) method was a fast and accurate method for calculating C–H BDEs at nitrogen α‐positions. By using the newly benchmarked BHandH method, the αC–H BDEs in a number of nitrogen‐containing drug molecules were calculated, where a dramatic variation of the αC–H BDEs was discovered. To understand this variation, the effects of mono‐ and double‐substitution at both carbon and nitrogen atoms on the αC‐H BDEs were systematically studied. The origin of the substitution effects was thoroughly discussed in terms of four categories of substituents.
Competitive Enzymatic Fluorescence Immunoassay for Human IgG by Using a Temperature‐Sensitive Phase Separating Polymer with Regulated Phase Transition Temperature
Authors: LIN Peng , WANG Yi‐Lei , FENG Jian‐Jun , ZOU Zhi‐Hua , YANG Qian 
Published: April 2008

AbstractA new enzymatic fluorescence immunoassay for human IgG was developed using a temperature‐sensitive polymer, poly(N‐isopropylacrylamide‐co‐acrylamide) [P(NIP‐AA)], as a carrier. The lower critical solution temperature of the P(NIP‐AA) containing molar fraction of 8% for AA was 37 °C. In a competitive immunoassay, immobilized IgG and the standard IgG (or sample) competed for binding to a horseradish peroxidase labeled antibody at 33 °C in homogeneous format. After changing the temperature to separate the polymer‐immune complex, the complex precipitate was re‐dissolved and determined by coupling with the fluorescence reaction of hydrogen peroxide and p‐hydroxyphenylacetic acid. The calibration graph for human IgG was linear over the range of 100–1000 ng/mL with a detection limit of 2.0 ng/mL. The method is rapid, sensitive and simple. The immune reaction efficiency was improved. In addition, the sensitivity of this method was close to that using traditional microtitration plates as carriers. However, the assay was much faster (the assay time decreased from 100–120 to 30 min). The method has been applied to the determination of the human IgG levels in human sera with satisfactory results.
Tuning Colloidal Interactions Through Coordination Chemistry
Authors: Joubert Mathieu , In Martin 
Published: April 2008

AbstractThe present work addresses the question of the range and amplitude of bridging attraction that is induced between surfactant micelles functionalized with complexing groups in the presence of coordination centers. An alkylethoxylated ester phosphate (AEP) is synthesized from a non‐ionic surfactant and anchored into DTAB micelles. In the absence of any coordination center, functionalized micelles repel each other. Phase behavior, dynamic light scattering and small angle neutrons scattering (SANS) experiments show that this repulsive interaction is switched to attractive by the addition of coordination centers such as aluminum cations. The extent of the composition range of coexisting phase depends on the concentration of coordination center and on the pH. Analysis of the structure factor obtained from SANS shows that the range of attraction is determined by the molecular dimension of the chelating surfactant, while the depth can be tuned with the concentration of coordination center and the pH. The strong influence of the pH is interpreted as arising from the condensation of aluminium cations that lead to high functional polynuclear complexes.
Pressure‐Induced Emission Enhancement of a Series of Dicyanovinyl‐Substituted Aromatics: Pressure Tuning of the Molecular Population with Different Conformations
Authors: Wang Qian , Li Shayu , He Liming , Qian Yan , Li Xiuping , Sun Wenhao , Liu Min , Li Juan , Li Yi , Yang Guoqiang 
Published: April 2008

AbstractA series of dicyanovinyl‐substituted aromatic compounds (Ar‐DCV; Ar=9‐anthracenyl, 1‐naphthyl, 1‐pyrenyl) with dual fluorescence are prepared, and their emission properties—when molecularly dispersed in a polymer medium—are investigated under pressure perturbation. The total emission intensity is enhanced drastically from ambient pressure up to 70 kbar. Emission 30–107 times more intense than that at ambient pressure is observed at higher pressure. In dual emission, the enhancement of the local excited state (LE state) is significantly different from that of the intramolecular charge‐transfer state (ICT state). The intensity of the ICT emission increases faster (30–370 times) than that of the LE emission (less than 20 times). In accordance with spectroscopic data, emission dynamics at different pressures, and computational studies on the molecular conformations of these compounds, a kinetic model is proposed to explain the effect of pressure on the emissive properties of the Ar‐DCV compounds from the point of view of pressure‐dependent populations of the species in the ground state.
(Thermo)dynamic Role of Receptor Flexibility, Entropy, and Motional Correlation in Protein–Ligand Binding
Authors: Baron Riccardo , McCammon J. Andrew 
Published: April 2008

AbstractThe binding of 2‐amino‐5‐methylthiazole to the W191G cavity mutant of cytochrome c peroxidase is an ideal test case to investigate the entropic contribution to the binding free energy due to changes in receptor flexibility. The dynamic and thermodynamic role of receptor flexibility are studied by 50 ns‐long explicit‐solvent molecular dynamics simulations of three separate receptor ensembles: W191G binding a K+ ion, W191G–2a5mt complex with a closed 190–195 gating loop, and apo with an open loop. We employ a method recently proposed to estimate accurate absolute single‐molecule configurational entropies and their differences for systems undergoing conformational transitions. We find that receptor flexibility plays a generally underestimated role in protein–ligand binding (thermo)dynamics and that changes of receptor motional correlation determine such large entropy contributions.
Selective Hydrogen Oxidation in the Presence of C3 Hydrocarbons Using Perovskite Oxygen Reservoirs
Authors: Beckers Jurriaan , Drost Ruben , van Zandvoort Ilona , Collignon Paul F. , Rothenberg Gadi 
Published: April 2008

AbstractPerovskite‐type oxides, ABO3, can be successfully applied as solid “oxygen reservoirs” in redox reactions such as selective hydrogen combustion. This reaction is part of a novel process for propane oxidative dehydrogenation, wherein the lattice oxygen of the perovskite is used to combust hydrogen selectively from the dehydrogenation mixture at 550 °C. This gives three key advantages: it shifts the dehydrogenation equilibrium to the side of the desired products, heat is generated, thus aiding the endothermic dehydrogenation, and it simplifies product separation (H2O vs H2). Furthermore, the process is safer since it uses the catalysts’ lattice oxygen instead of gaseous O2. We screened fourteen perovskites for activity, selectivity and stability in selective hydrogen combustion. The catalytic properties depend strongly on the composition. Changing the B atom in a series of LaBO3 perovskites shows that Mn and Co give a higher selectivity than Fe and Cr. Replacing some of the La atoms with Sr or Ca also affects the catalytic properties. Doping with Sr increases the selectivity of the LaFeO3 perovskite, but yields a catalyst with low selectivity in the case of LaCrO3. Conversely, doping LaCrO3 with Ca increases the selectivity. The best results are achieved with Sr‐doped LaMnO3, with selectivities of up to 93 % and activities of around 150 μmol O m−2. This catalyst, La0.9Sr0.1MnO3, shows excellent stability, even after 125 redox cycles at 550 °C (70 h on stream). Notably, the activity per unit surface area of the perovskite catalysts is higher than that of doped cerias, the current benchmark of solid oxygen reservoirs.
Immunocytochemical staining of p16ink4a protein as an adjunct test in equivocal liquid‐based cytology
Authors: Shin Eun Kyoung , Lee Sa Ra , Kim Mi Kyoung , Kang Eun Ji , Ju Woong , Lee Shi Nae , Han Woon Sup , Kim Seung Cheol 
Published: April 2008

AbstractFor cervical cancer screening, HPV‐DNA test is expensive and is not easily available in all clinical situations. Thus, we investigated the role of p16ink4a immunostaining as another adjunct test to diagnose cervical neoplasia in equivocal liquid based cytology. Eighty‐seven patients were randomly selected for this study (3 patients with normal, 84 patients with abnormal including 24 ASCUS, 30 LSIL, and 30 HSIL). We performed p16ink4a immunostaining on ThinPrep® slide and on each case from the corresponding cervical biopsy tissues. High‐risk HPV‐DNA testing was also performed on all the subjects. We found that the immunoreactivity of p16ink4a is strongly correlated with the grade of cytologic and histologic diagnoses as well as with Hybrid Capture 2. In comparing the p16ink4a immunostaining with the Hybrid Capture 2 for accuracy of the diagnosis of CIN II/III or a higher‐grade disease in the case of ASCUS/LSIL on ThinPrep®, no significant differences were observed. Our data implies that p16ink4a immunocytochemical staining in liquid‐based cytology specimens might be used as a good adjunct test to predict cervical histology in equivocal ThinPrep® tests. Diagn. Cytopathol. 2008;36:311–316. © 2008 Wiley‐Liss, Inc.
Gardnerella vaginalis and Lactobacillus sp in liquid‐based cervical samples in healthy and disturbed vaginal flora using cultivation‐independent methods
Authors: Klomp Johanna M. , Verbruggen Banut‐Sabine M. , Korporaal Hans , Boon Mathilde E. , de Jong Pauline , Kramer Gerco C. , van Haaften Maarten , Heintz A. Peter M. 
Published: April 2008

AbstractOur objective was to determine the morphotype of the adherent bacteria in liquid‐based cytology (LBC) in smears with healthy and disturbed vaginal flora. And to use PCR technology on the same fixed cell sample to establish DNA patterns of the 16S RNA genes of the bacteria in the sample. Thirty samples were randomly selected from a large group of cervical cell samples suspended in a commercial coagulant fixative “(BoonFix).” PCR was used to amplify DNA of five bacterial species: Lactobacillus acidophilus, Lactobacillus crispatus, Lactobacillus jensenii, Gardnerella vaginalis, and Mycoplasma hominis. The LBC slides were then analyzed by light microscopy to estimate bacterial adhesion. DNA of lactobacilli was detected in all cell samples. Seventeen smears showed colonization with Gardnerella vaginalis (range 2.6 × 102–3.0 × 105 bacteria/μl BoonFix sample). Two cases were identified as dysbacteriotic with high DNA values for Gardnerella vaginalis and low values for Lactobacillus crispatus. The sample with the highest concentration for Gardnerella vaginalis showed an unequivocal Gardnerella infection. This study indicates that the adherence pattern of a disturbed flora in liquid‐based cervical samples can be identified unequivocally, and that these samples are suitable for quantitative PCR analysis. This cultivation independent method reveals a strong inverse relationship between Gardnerella vaginalis and Lactobacillus crispatus in dysbacteriosis and unequivocal Gardnerella infection. Diagn. Cytopathol. 2008;36:277–284. © 2008 Wiley‐Liss, Inc.
Evaluation of performance of EUS‐FNA in preoperative lymph node staging of cancers of esophagus, lung, and pancreas
Authors: Peng H. Q. , Greenwald B. D. , Tavora F. R. , Kling E. , Darwin P. , Rodgers W. H. , Berry A. 
Published: April 2008

AbstractWe reviewed the cytologic and histologic diagnoses and EUS report of 77 consecutive patients who had undergone EUS‐FNA preoperative staging for esophageal, lung, and pancreatic cancers at our institution. A total of 122 EUS‐FNA lymph nodes were identified. Thirty of 77 cases had histologic follow‐up. Using surgical node staging and/or surgical resection as the reference standard, the sensitivity, specificity, accuracy, and positive and negative predictive values were 75%, 95%, 89%, 86%, and 90%, respectively, for EUS‐FNA node staging. We compared cytologically malignant and benign lymph node groups with eight EUS parameters including the total number of lymph nodes found by EUS, the shape, margin, long axis, short axis, echogenicity, location of the lymph node, and EUS tumor staging. We found that the short axis is the best EUS feature to predict malignancy. Lymph nodes found in an abdominal location in esophageal and lung cancer are likely malignant. Diagn. Cytopathol. 2008;36:290–296. © 2008 Wiley‐Liss, Inc.
Diagnostic accuracy of fine‐needle aspiration cytology of palpable breast masses: An SROC curve with fixed and random effects linear meta‐regression models
Authors: Akçil Mehtap , Karaağaoğlu Ergun , Demirhan Beyhan 
Published: April 2008

AbstractWe used various meta‐analytic methods to compare 25 studies describing fine‐needle aspiration (FNA) cytologic analyses performed from 1984 to 2007 on palpable breast masses. We found that in the 25 studies examined, the sensitivity ranged from 78% to 100%, the specificity ranged from 76% to 100%, and the diagnostic odds ratio (DOR) ranged from 15.83 to 33 198. The overall diagnostic accuracy was found to be as follows: 0.93 (95% CI: 0.92–0.94) for sensitivity, 0.98 (95% CI: 0.97–0.98) for specificity, and 505.209 (95% CI: 273.08–934.95) for the DOR. The overall diagnostic accuracy according to the results of summary receiving operating characteristic (SROC) curve analysis was 0.95 ± 0.0032, and the overall weighted area under the (receiving operating characteristic [ROC]) curve (AUC) was 0.99 ± 0.0014. The DOR values did not show a large variation in the various positivity threshold values. However, the results of those studies had some heterogeneity. The four covariates that were added to the standard SROC model to evaluate variations in the results of the studies were the year of publication, the number of aspirations, the percentage of insufficient material, and the study design. The relative diagnostic accuracy of studies performed after 1990 was 3.98 times higher than that of studies performed before 1990. The relative DOR (RDOR) value was also found to be statistically significant (95% CI: 1.22–13.02). That result may be attributed to the technologic improvements in diagnostic tools over the years. Although it was not statistically significant, an increase in the number of aspirations caused an increase in the RDOR of the FNA cytology (95% CI: 0.52–8.11). In contrast, increasing the percent of insufficient material caused a statistically insignificant but clinically significant decrease in the RDOR of FNA (RDOR = 0.79, 95% CI: 0.21–2.98). In conclusion, our meta‐analysis has shown that FNA cytologic analysis of palpable breast masses is highly accurate in the diagnostic differentiation of benign from malignant tumors. Diagn. Cytopathol. 2008;36:303–310. © 2008 Wiley‐Liss, Inc.
Cyst fluid cytology of cerebellar hemangioblastoma: A case report
Authors: Lallu Sharda , Naran Sarla , Palmer David , Bethwaite Peter 
Published: April 2008

AbstractHemangioblastoma, an uncommon central nervous system neoplasm, commonly located in the cerebellum and more rarely in the spinal cord. In this report, we described the cytologic features of a cerebellar hemangioblastoma in a 53‐year‐old man, present in cystic fluid obtained at cranioctomy. Cytologic preparations were characterized by well preserved, scattered dissociate, and occasional groups of stromal cells with round to oval nuclei, fine chromatin, and lacelike or granular, vacuolated eosinophilic cytoplasm with a foamy appearances. In addition, calcific material, endothelial‐like cells, blood, and macrophages were seen. The radiologic impression, cytologic features, and location led us to suggest the possibility of hemangioblastoma. Subsequent histopathological material revealed the characteristic features of hemangioblastoma. Diagn. Cytopathol. 2008;36:341–343. © 2008 Wiley‐Liss, Inc.
Cytologic findings of acquired cystic disease‐associated renal cell carcinoma: A report of two cases
Authors: Rivera Michael , Tickoo Satish K. , Saqi Anjali , Lin Oscar 
Published: April 2008

AbstractRenal tumors may arise in the setting of end‐stage renal cell disease. The risk is 100 times that of the normal population with an incidence ranging from 3–7%. The most common malignant tumor to arise in the setting of acquired cystic disease of the kidney is the acquired cystic disease‐associated renal cell carcinoma (ACD‐associated RCC). The cytomorphologic features of ACD‐associated RCC, which has not been described previously, show moderately cellular specimens composed of clusters of cells with papillary configuration. The cells ranged from polygonal to columnar and contained abundant eosinophilic granular cytoplasm. The nuclei were round and centrally located, and the chromatin was finely granular with prominent central nucleoli that corresponded to Fuhrman's grade 3 nucleolar size. The main differential diagnosis is type 2 papillary renal cell carcinoma, from which it can be distinguished based on clinical findings only at this moment. Diagn. Cytopathol. 2008;36:344–347. © 2008 Wiley‐Liss, Inc.
Chromatin remodeling during mouse and human embryonic stem cell differentiation
Authors: Golob Jonathan L. , Paige Sharon L. , Muskheli Veronica , Pabon Lil , Murry Charles E. 
Published: April 2008

AbstractEmbryonic stem cell (ESC) differentiation is an excellent model to study chromatin changes at developmentally regulated loci. Differentiating mouse and human ESCs increase genome‐wide acetylation (euchromatic) and tri‐methylation (heterochromatic) of lysine 9 on histone H3. The Oct4 locus is euchromatic when expressed in undifferentiated ESCs and heterochromatic after differentiation. Brachyury T, a mesoderm‐specific transcription factor, is not yet expressed in undifferentiated cells, where its locus has “bivalent” tri‐methyl lysine 4 and lysine 27 modifications. During directed differentiation to pre‐cardiac mesoderm, the activated brachyury locus has high levels of tri‐methyl lysine 4 (euchromatin), switching to heterochromatin after gene silencing. Thus, ESC differentiation is accompanied by genome‐wide commitment to euchromatin or heterochromatin. Undifferentiated hESCs bivalently modify the brachyury locus, activate it to euchromatin during mesoderm induction, and subsequently repress it to heterochromatin, demonstrating, to our knowledge, the first analysis of chromatin dynamics at a locus essential for mesoderm and endoderm differentiation. Developmental Dynamics 237:1389‐1398, 2008. © 2008 Wiley‐Liss, Inc.
Straightforward Synthesis of α‐Substituted Prolines by Cross‐Metathesis
Authors: Lumini Marco , Cordero Franca M. , Pisaneschi Federica , Brandi Alberto 
Published: April 2008

AbstractThe synthesis of several α‐substituted N‐Boc‐protected prolines has been achieved by cross metathesis (CM) of N‐Boc‐allylproline 5 with terminal long chain alkenes and alkenes bearing hydroxy, silyloxy, ester, and O‐acetylglucosamido groups. The CM occurred with good selectivity and short reaction time under microwave heating conditions, affording yields in the range of 40–92 %. Addition of Ti(OiPr)4 as a Lewis acid allowed a slight increase of the yield in the case of alkenes with Lewis basic substituents. The CM was also successfully applied to allylproline protected with trichloroacetaldehyde 4, but the intermediate products were less practical for further deprotection and elaboration. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Efficient Route to Highly Water‐Soluble Aromatic Cyclic Hydroxamic Acid Ligands
Authors: Seitz Michael , Raymond Kenneth N. 
Published: April 2008

Abstract2‐Hydroxyisoquinolin‐1‐one (1,2‐HOIQO) is a new member of the important class of aromatic cyclic hydroxamic acid ligands which are widely used in metal sequestering applications and metal chelating therapy. The first general approach for the introduction of substituents at the aromatic ring of the chelating moiety is presented. As a useful derivative, the highly water‐soluble sulfonic acid has been synthesized by an efficient route that allows general access to 1,2‐HOIQO 3‐carboxylic acid amides, which are the most relevant for applications. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Human germline and somatic cells have similar TP53 and Kirsten‐RAS gene single base mutation frequencies
Authors: Cole Derek N. , Carlson J. Andrew , Wilson Vincent L. 
Published: April 2008

AbstractUnderstanding the risk of offspring inheriting rare mutations, and the frequencies at which these mutations are present in germ cells can be explored with direct analysis of human semen samples. The present work utilized the ultrasensitive PCR/RE/LCR mutation assay to detect, identify and determine the prevalence single base substitution mutations in the TP53 and KRAS genes in human sperm. Four disease‐associated base sites in the TP53 and KRAS genes, three of which are known to be heritable to live, term offspring, were studied in sperm from eleven human semen specimens. Eight of the specimens (73%) displayed single base substitution mutations, and 30% of all base sites tested were found to harbor mutations ranging in prevalence from 1 × 10−6 to 1 × 10−5 wild type sperm. These germ cell single base substitution mutation frequencies are very similar to somatic tissue TP53 and KRAS mutation frequencies. Equivalent single base mutation frequencies in both germ and somatic cells suggest that there is no unusual selection or mutation protective process operating premeiotically in the germline, and that a selection bias at the level of sperm viability, conception, early cleavage, implantation, and/or embryogenesis operates to exclude the majority of these TP53 mutations and all of the activating KRAS mutations. Environ. Mol. Mutagen., 2008. © 2008 Wiley‐Liss, Inc.