bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Characterization of Poly(ε‐caprolactone‐co‐δ‐ valerolactone) with Pendant Carboxylic Functional Groups
Authors: Zeng Yue , Zhang Yan , Lang Meidong 
Published: March 2011

AbstractIn this paper, aliphatic polyesters functionalized with pendant carboxylic groups were synthesized via several steps. Firstly, substituted cyclic ketone, 2‐(benzyloxycarbonyl methyl)cyclopentanone (BCP) was prepared through the reaction of enamine with benzyl‐2‐bromoacetate, and subsequently converted into the relevant functionalized δ‐valerolactone derivative, 5‐(benzyloxy carbonylmethyl)‐δ‐valerolactone (BVL) by the Baeyer‐Villiger oxidation. Secondly, the ring‐opening polymerization of BVL with ε‐caprolactone was carried out in bulk using stannous octoate as the catalyst to produce poly(ε‐caprolactone‐co‐δ‐valerolactone) bearing the benzyl‐protected carboxyl functional groups [P(CL‐co‐BVL)]. Finally, the benzyl‐protecting groups of P(CL‐co‐BVL) were effectively removed by H2 using Pd/C as the catalyst to obtain poly(ε‐caprolactone‐co‐δ‐valerolactone) bearing pendant carboxylic acids [P(CL‐co‐CVL)]. The structure and the properties of the polymer have been studied by Nuclear Magnetic Resonance (NMR), Fourier Infrared Spectroscopy (FT‐IR) and Differential Scan Calorimetry (DSC) etc. The NMR and FT‐IR results confirmed the polymer structure, and the 13C NMR spectra have clearly interpreted the sequence of ε‐caprolactone and 5‐(benzyloxycarbonylmethyl)‐δ‐valerolactone in the copolymer. When the benzyl‐protecting groups were removed, the aliphatic polyesters bearing carboxylic groups were obtained. Moreover, the hydrophilicity of the polymer was improved. Thus, poly(ε‐caprolactone‐co‐δ‐valerolactone) might have great potential in biomedical fields.
Combination of Silica Sol and Potassium Silicate via Isothermal Heat Conduction Microcalorimetry
Authors: Tian Hebao , Zhang Chaocan , Liu Peng , Li Xi , Wu Lili , Chen Yanjun 
Published: March 2011

AbstractIsothermal heat conduction microcalorimetry was utilized as a novel characterization method to investigate the polymerization processes of silica with both thermodynamic and kinetic parameters when the combination of silica sol and potassium silicate was stirred at temperatures of 25.0, 35.0, and 45.0°C. The silica polymerization was characterized by the greater enthalpy change at each higher temperature and by the reaction orders of the silica sol and potassium silicate, which varied rapidly, instantaneously, and constantly from low to high all the time, up and down in an alternate manner. When the reaction order of the silica sol and potassium silicate was 3.0, the maximum rate constant occurred at 25.0°C (k=1.22×10−4mol−2·dm6·s−1). The two temperature regions (25.0–35.0°C region with a faster rate and 35.0–45.0°C region with a lower rate) reflected a two‐stage oligomerization of silica monomers with different oligomers formed in a two‐step anionic mechanism. The measurements of particle size and pH value showed that the colloidal particles in the mixed silica sol and potassium silicate first dissolved, then "active" silica in the potassium silicate redeposited to make a distinct particle size distribution (Z‐average size, 33.0–14.9 nm at 25.0°C) influenced both by pH value (9.82–11.97 at 25.0°C) and the mass fraction (53, 65, 75, and 85 mass/%) of the silica sol in the mixture. The processes of combination of the silica sol and potassium silicate did not result from acid‐base neutralization reactions but from a complex polymerization of the "active" silica components which relate to silica monomers oligomerization with heat evolved (the total enthalpy changes, 1.6234–3.3882 J).
Design, Synthesis, and in vitro Antifungal Activity of 1‐[(4‐Substituted‐benzyl)methylamino]‐2‐(2,4‐difluorophenyl)‐3‐(1H‐1,2,4‐triazol‐1‐yl)propan‐2‐ols
Authors: Guillon Rémi , Pagniez Fabrice , Giraud Francis , Crépin Damien , Picot Carine , Le Borgne Marc , Morio Florent , Duflos Muriel , Logé Cédric , Le Pape Patrice 
Published: March 2011

AbstractAs part of our studies focused on the design of 1‐[((hetero)aryl‐ and piperidinylmethyl)amino]‐2‐phenyl‐3‐(1H‐1,2,4‐triazol‐1‐yl)propan‐2‐ols as antifungal agents, we report the development of new extended benzylamine derivatives substituted at the para position by sulfonamide or retrosulfonamide groups linked to alkyl or aryl chains. These molecules have broad‐spectrum antifungal activities not only against Candida spp., including fluconazole‐resistant strains, but also against a filamentous species (A. fumigatus). Concerning fluconazole resistance, selected compounds exhibit the capacity to overcome CDR and ERG11 gene upregulation and to maintain antifungal activity despite a recognized critical CYP51 substitution in C. albicans isolates. Synthesis, investigation of the mechanism of action by sterol analysis in a C. albicans strain, and structure–activity relationships (SARs) are reported.
Prognostic significance of immunophenotypic and karyotypic features of Philadelphia positive B‐lymphoblastic leukemia in the era of tyrosine kinase inhibitors
Authors: Jaso Jesse , Thomas Deborah A. , Cunningham Krista , Jorgensen Jeffrey L. , Kantarjian Hagop M. , Medeiros L. Jeffrey , Wang Sa A. 
Published: March 2011

AbstractBACKGROUND:Philadelphia chromosome (Ph)‐positive B‐lymphoblastic leukemia exhibits immunophenotypic, karyotypic, and molecular genetic heterogeneity. The prognostic significance of these parameters was assessed in the context of intensive tyrosine kinase inhibitor (TKI)‐based chemotherapy.METHODS:The authors studied 65 adult patients with Ph‐positive acute lymphoblastic leukemia (ALL) who received treatment with TKI‐based therapy, correlated their clinicopathologic heterogeneity with patient outcome, and compared the findings with those from 60 adult patients with diploid B‐cell ALL who received similar chemotherapy without a TKI.RESULTS:Ph‐positive ALL was associated with older age (P = .01), the common‐B immunophenotype characterized by a greater frequency of CD13 (alanine aminopeptidase) coexpression (P = .004), CD66c (carcinoembryonic antigen‐related cell adhesion molecule 3) expression (P = .007), and CD25 (interleukin‐2 receptor alpha chain) expression (P < .001) and with a lower frequency of CD15 (3‐fucosyl‐N‐acetyl‐lactosamine) expression (P < .001). Conventional karyotypic analyses indicated that the Ph chromosome was the sole abnormality in 19 patients (30%), was present with other aberrancies in 43 patients (65%), and was absent (detectable only by fluorescence in situ hybridization [FISH] or quantitative reverse transcriptase‐polymerase chain reaction [RT‐PCR] analysis) in 3 patients (5%). The presence of the breakpoint cluster region–v‐Abelson murine leukemia viral oncogene homolog fusion gene (BCR‐ABL) was confirmed in all patients by FISH or RT‐PCR (the 190‐kDa protein [p190] construct was present in 49 patients [77%], and the p210 fusion transcript construct was present in 15 patients [23%]). The presence of a supernumerary Ph chromosome was correlated with a higher incidence of CD20 (B‐lymphocyte antigen, nonglycosylated phosphoprotein) expression (P < .001), whereas the p210 construct was correlated with aberrant CD25 expression (P = .05). Outcomes were not influenced by the degree of karyotypic complexity (including the presence or absence of a supernumerary Ph chromosome), CD20 expression, or myeloid antigen expression (CD13, CD33 [myeloid lineage transmembrane receptor], CD66c). CD25 expression was associated with inferior survival in univariate analysis (P = .051) but not in multivariate analysis (P = .092).CONCLUSIONS:In the context of intensive, TKI‐based chemotherapy, the immunophenotypic, karyotypic, and molecular heterogeneity of Ph‐positive ALL no longer influences outcome. Cancer 2011. © 2011 American Cancer Society.
Prevention of intrahepatic distant recurrence by transcatheter arterial infusion chemotherapy with platinum agents for stage I/II hepatocellular carcinoma
Authors: Ishikawa Toru , Higuchi Kazuo , Kubota Tomoyuki , Seki Keiichi , Honma Terasu , Yoshida Toshiaki , Kamimura Tomoteru 
Published: March 2011

AbstractBACKGROUND:The effectiveness of additional chemotherapy in preventing intrahepatic distant tumor recurrence of hepatocellular carcinoma (HCC) has not been fully established. The authors compared the efficacy of 2 platinum‐based chemotherapeutic agents in combination with radical local treatment for preventing intrahepatic distant recurrence (IDR).METHODS:Seventy‐eight patients with stage I/II HCC aged 45 to 85 years underwent transcatheter arterial chemoembolization and/or radiofrequency ablation after they received hepatic arterial infusion (HAI) of platinum compounds. The HAI consisted of cis‐diammine(1,1‐cyclobutanedicarboxylato)platinum(II) (carboplatin) in 25 patients and cis‐diamminedichloroplatinum (II) (cisplatin) in 53 patients. Multivariate analysis was used to identify independent factors that were associated with IDR.RESULTS:Cumulative IDR rates at 1 year, 2 years, and 3 years were 21.7%, 52.2% and 75.7%, respectively, in the carboplatin group and 8.1%, 22.7%, and 36.9%, respectively, in the cisplatin group. The cisplatin group had a significantly lower IDR rate compared with the carboplatin group. The selection of a platinum agent was 1 of the independent factors for IDR in a multivariate Cox proportional hazards model.CONCLUSIONS:HAI chemotherapy with cisplatin before radical local treatment was effective in patients with HCC. The authors concluded that radical local treatment with concurrent HAI using cisplatin may contribute to a longer progression‐free period, which could be predicted with intrahepatic imaging in patients with stage I/II HCC. Cancer 2011;. © 2011 American Cancer Society.
Formation of solid tumors by a single multinucleated cancer cell
Authors: Weihua Zhang , Lin Qingtang , Ramoth Asa J. , Fan Dominic , Fidler Isaiah J. 
Published: March 2011

AbstractBACKGROUND:Large multinucleated cells (MNCs) commonly exist in tumorigenic cancer cell lines that are used widely in research. However, the contributions of MNCs to tumorigenesis are unknown.METHODS:In this study, MNCs were characterized in the murine fibrosarcoma cell line UV‐2237 in vitro and in vivo at the single‐cell level.RESULTS:The authors observed that MNCs originated from a rare subpopulation of mononuclear cells and were positive for a senescent marker, β‐galactosidase. In addition, MNCs were responsible for the majority of clonogenic activity when cultured in hard agar; they were more resistant to chemotherapeutic agents than mononuclear cells; they could undergo asymmetric division (producing mononuclear cells) and self‐renewal in vitro and in vivo; and, most important; a single MNC produced orthotopic, subcutaneous tumors (composed mainly of mononuclear cells) that gave rise to spontaneous lung metastases in nude mice.CONCLUSIONS:The current results indicated that the growth of MNCs may be arrested under stress and that MNCs are highly resistant to chemotherapy and can generate clonal, orthotopic, metastatic tumors. Cancer 2011. © 2011 American Cancer Society.
Ion‐Induced Fragmentation of Amino Acids: Effect of the Environment
Authors: Maclot Sylvain , Capron Michael , Maisonny Rémi , Ławicki Arkadiusz , Méry Alain , Rangama Jimmy , Chesnel Jean‐Yves , Bari Sadia , Hoekstra Ronnie , Schlathölter Thomas , Manil Bruno , Adoui Lamri , Rousseau Patrick , Huber Bernd A. 
Published: March 2011

AbstractIn general, radiation‐induced fragmentation of small amino acids is governed by the cleavage of the CCα bond. We present results obtained with 300 keV Xe20+ ions that allow molecules (glycine and valine) to be ionised at large distances without appreciable energy transfer. Also in the present case, the CCα bond turns out to be the weakest link and hence its scission is the dominant fragmentation channel. Intact ionised molecules are observed with very low intensities. When the molecules are embedded in a cluster of amino acids, a protective effect of the environment is observed. The fragmentation pattern changes: the CCα bond becomes more protected and stable amino acid cations are observed as fragments of the molecular clusters. Evidently, the molecular cluster acts as a “buffer” for the excess energy, capable of rapidly redistributing excess energy and charge.
Energetics of Diatomic Transition Metal Sulfides ScS to FeS with Diffusion Quantum Monte Carlo
Authors: Petz René , Lüchow Arne 
Published: March 2011

AbstractThe diatomic transition metal sulfides ScS to FeS are investigated by means of diffusion quantum Monte Carlo (DMC). New soft pseudopotentials are compared to the standard Stuttgart pseudopotentials in terms of efficiency. The DMC results obtained for the dissociation energies with both kinds of pseudopotentials are compared with previous results from other groups. DMC shows a higher overall accuracy than both B3LYP and CCSD(T). Furthermore, ionization energies are calculated with bond lengths optimized at the BP86 and DMC level of theory and compared to previous B3LYP results.
Energy rate density. II. Probing further a new complexity metric
Authors: Chaisson E.J. 
Published: March 2011

AbstractAppraisal of the concept of energy rate density continues, as both a potential quantitative metric for complexity studies and a key feature of a unifying hypothesis for the origin and evolution of material systems throughout Nature writ large. This article extends a recent study reported in this journal, hereby analyzing normalized energy flows for an array of complex systems experiencing physical, biological, and cultural evolution. The results strengthen the comprehensive scenario of cosmic evolution in broad and general ways yet with much deep, empirical evidence. © 2011 Wiley Periodicals, Inc. Complexity 2011
Molybdenum and Tungsten Oxidoreductase Models (Eur. J. Inorg. Chem. 8/2011)
Authors: Schulzke Carola 
Published: March 2011

AbstractThe cover picture shows the different aspects that contribute to the optimisation of processes catalysed by molybdenum‐ and tungsten‐dependent oxidoreductases, such as active‐site geometry, proteinic and non‐proteinic ligands, temperature and the metal itself. At the centre, the inorganic site of tungsten‐substituted DMSO reductase from Rhodobacter capsulatus is shown (generated with Jmol; PDB‐ID 1E18). Details are presented in the Microreview by C. Schulzke on p. 1189 ff.
Highly Efficient Total Synthesis of the Clostridium‐Derived anti‐MRSA Antibiotic Closthioamide (Eur. J. Org. Chem. 8/2011)
Authors: Kloss Florian , Lincke Thorger , Hertweck Christian 
Published: March 2011

AbstractThe cover picture shows the structure of closthioamide, the first example of secondary metabolites produced by anaerobic bacteria (see bottom, scanning‐electron micrograph of the natural producer Clostridium cellulolyticum). The natural product exhibits high antimicrobial activity, in particular against resistant pathogens (MRSA and VRE, see background). Because closthioamide represents a novel drug scaffold and its availability is limited by low production rates in C. cellulolyticum cultures, we developed a highly efficient total synthesis involving convergent peptide coupling and polythionation. Details are discussed in the Short Communication by C. Hertweck et al. on p. 1429 ff. We thank Dr. S. Nietzsche (Electron Microscopy Centre of the University Hospital, Jena) for providing scanning‐electron micrographs and Nico Ueberschaar for graphical processing.
Application of CFD Techniques in the Modelling and Simulation of PBI PEMFC
Authors: Doubek G. , Robalinho E. , Cunha E. F. , Cekinski E. , Linardi M. 
Published: March 2011

AbstractIn the present work two 3‐D models, for the catalytic layer, were employed in order to simulate the responses of a PBI high temperature polymeric membrane fuel cell. The simulations made use of an agglomerate model and a pseudo‐homogenous model, both implemented taking into account the temperature influence over their parameters. The overall simulation was performed also as two models, linked by the variable pressure, one for the whole graphite plate simulating the distribution channels, and the other dealing with the MEA and thereof the catalytic layer. A discussion over the two models was done and the experimental results demonstrated that the pseudo‐homogeneous obtained the better fits.
Intraday price discovery and volatility transmission in stock index and stock index futures markets: Evidence from China
Authors: Yang Jian , Yang Zihui , Zhou Yinggang 
Published: March 2011

AbstractUsing high‐frequency data, this study investigates intraday price discovery and volatility transmission between the Chinese stock index and the newly established stock index futures markets in China. Although the Chinese stock index started a sharp decline immediately after the stock index futures were introduced, the cash market is found to play a more dominant role in the price discovery process. The new stock index futures market does not function well in its price discovery performance at its infancy stage, apparently due to high barriers to entry into this emerging futures market. Based on a newly proposed theoretically consistent asymmetric GARCH model, the results uncover strong bidirectional dependence in the intraday volatility of both markets. © 2011 Wiley Periodicals, Inc. Jrl Fut Mark
Comparison of methods and sampling designs to test for association between rare variants and quantitative traits
Authors: Bacanu Silviu‐Alin , Nelson Matthew R. , Whittaker John C. 
Published: March 2011

AbstractGenome‐wide association studies succeeded in finding genetic variants associated with various phenotypes, but a large portion of the predicted genetic contribution to many traits remains unknown. One plausible explanation is that some missing variation is due to rare variants. Latest sequencing technology facilitates the investigation of such rare variants, but their statistical analysis remains challenging. For quantitative traits, a commonly used approach is to contrast the frequency of putatively functional rare variants between subjects in the two tails of the trait distribution. The contrast is usually performed by Fisher's exact or similar test. These tests are conservative as they discard trait rank information and are most useful under the unrealistic homogeneity assumption (i.e., variants have similar effects). We propose, and investigate via simulations, various designs for resequencing studies and statistical methods that incorporate information about rank, predicted function and allow for heterogeneity of effects. We propose designs which accommodate heterogeneity by sequencing both tails and the middle of the trait and novel statistical tests for trend, for heterogeneity and for a combination of the two. The conclusions of the simulations are four fold: (1) sequencing both tails and the middle of the trait distributions is desirable when heterogeneity is suspected, (2) trend and heterogeneity statistics should be used alongside other methods, (3) using rank information improves power over Fisher's exact test when the number of rare variants is not very large and (4) due to high misclassification rates, incorporating current predictions of a variant's function does not improve power. Genet. Epidemiol. 35: 226‐235, 2011.  © 2011 Wiley‐Liss, Inc.
Efficient study design for next generation sequencing
Authors: Sampson Joshua , Jacobs Kevin , Yeager Meredith , Chanock Stephen , Chatterjee Nilanjan 
Published: March 2011

AbstractNext Generation Sequencing represents a powerful tool for detecting genetic variation associated with human disease. Because of the high cost of this technology, it is critical that we develop efficient study designs that consider the trade‐off between the number of subjects (n) and the coverage depth (µ). How we divide our resources between the two can greatly impact study success, particularly in pilot studies. We propose a strategy for selecting the optimal combination of n and µ for studies aimed at detecting rare variants and for studies aimed at detecting associations between rare or uncommon variants and disease. For detecting rare variants, we find the optimal coverage depth to be between 2 and 8 reads when using the likelihood ratio test. For association studies, we find the strategy of sequencing all available subjects to be preferable. In deriving these combinations, we provide a detailed analysis describing the distribution of depth across a genome and the depth needed to identify a minor allele in an individual. The optimal coverage depth depends on the aims of the study, and the chosen depth can have a large impact on study success. Genet. Epidemiol. 35: 269‐277, 2011.  © 2011 Wiley‐Liss, Inc.
Training‐induced neuroanatomical plasticity in ADHD: A tensor‐based morphometric study
Authors: Hoekzema Elseline , Carmona Susanna , Ramos‐Quiroga J. Antoni , Barba Erika , Bielsa Anna , Tremols Virginia , Rovira Mariana , Soliva Juan Carlos , Casas Miguel , Bulbena Antoni , Tobeña Adolf , Vilarroya Oscar 
Published: March 2011

AbstractExperience‐based neuroplasticity has typically been associated with functional changes, but growing evidence indicates that training can also render dynamic structural alterations in the brain. Although research on training‐induced morphological plasticity has consistently demonstrated rapid increases of gray matter volume in task‐related regions, no studies have examined if local volumetric reductions in gray matter associated with certain psychiatric disorders may be reversible by adequate training. We aimed to assess whether a training program applied to ADHD patients can contravene some of the associated neuroanatomical alterations. High‐resolution anatomical scans were acquired before and after the training period, and a whole‐brain tensor‐based morphometric approach was applied to extract a voxel‐wise estimation of longitudinal changes in regional gray matter volume. Our results show focal volumetric gray matter increases in bilateral middle frontal cortex and right inferior–posterior cerebellum after cognitive training compared with the ADHD control group. The extent of gray matter volume increase in the inferior–posterior cerebellum was associated with attentional performance. These findings illustrate the capacity of the nervous system for rapid morphological adjustments in response to environmental triggers. Moreover, the dorsolateral prefrontal cortex and cerebellum are commonly considered sites of volumetric reduction in ADHD, and the inferior–posterior lobule of the cerebellum is associated with progressive symptom‐related volume loss. Hence, the clusters of volumetric change observed in our study were confined to structures typically characterized by volume reduction in ADHD patients, providing preliminary indications that cognitive training may contravene some of the neuroanatomical deficits associated with the disorder. Hum Brain Mapp, 2010. © 2010 Wiley‐Liss, Inc.