bluuebunny/crossref_metadata_2025_split huggingface dataset:
4,5‐Bis(dialkylamino)‐Substituted Imidazolium Systems: Facile Access to N‐Heterocyclic Carbenes with Self‐Umpolung Option
Authors: Huber Stefan M. , Heinemann Frank W. , Audebert Pierre , Weiss Robert 
Published: October 2011

AbstractThe first synthesis of 4,5‐bis‐ (dimethylamino)‐substituted imidazolium compounds was developed, which is based on the reaction of a 1,2‐diamino‐1,2‐bis(phosphonio)ethene with lithiated formamidines. This represents the first application of this class of ethene derivatives for the preparation of heterocycles. These N‐heterocyclic carbene (NHC) precursors show a remarkably reduced basicity and nucleophilicity of their NMe2 groups, which is due to the strong anomeric interactions of the latter with the imidazolium core. According to DFT calculations, these NHCs are capable of self‐umpolung if sufficiently strong acceptor substituents are introduced at the carbene center. To test the self‐umpolung capabilities of the NHCs, various substituents were attached to the carbene center and the obtained compounds were characterized by single‐crystal X‐ray analysis as well as quantum chemical computations. Strong acceptor substituents are required to induce self‐umpolung, such as in the phosphonio‐substituted derivative, for which partial self‐umpolung was found. The N,N′‐bis(4‐dimethylaminophenyl)‐substituted imidazolium compound represents a special case, as it incorporates as much as three two‐step redox systems within the NHC framework. This will probably result in a high electronic flexibility of the corresponding nucleophilic carbenes, especially when they serve as ligands in transition metal complexes.
RNA‐Gerüst bringt Ordnung in die Zelle
Authors: Groß Michael 
Published: October 2011

AbstractDie noch in den Kinderschuhen steckende synthetische Biologie will die lebende Zelle neu erschaffen und dabei irgendwie anders gestalten. Wie das synthetische Leben jedoch aussehen soll, weiß man noch nicht genau. Zu den wenigen Beispielen gehören ein künstlicher Stoffwechselweg und Craig Venters synthetisches Bakterien‐Genom. Jetzt kommt ein Gerüst hinzu, das in einer Bakterienzelle für Ordnung sorgt.
Soil Budget, Net Export, and Potential Sinks of Nitrogen in the Lower Oglio River Watershed (Northern Italy)
Authors: Soana Elisa , Racchetti Erica , Laini Alex , Bartoli Marco , Viaroli Pierluigi 
Published: October 2011

AbstractA nitrogen mass balance, realized for the lower Oglio River basin (Po River Plain, northern Italy), suggested an elevated impact of agricultural activities in this watershed. Livestock manure, synthetic fertilizers, biological fixation, atmospheric deposition, and wastewater sludge contributed 51, 34, 12, 2, and 1% of total N (TN) input, respectively (basin average 450 kg N ha−1 arable land (AL) year−1, overall input 100 115 t N year−1). Crop uptake, ammonia volatilization and denitrification in soils contributed 65, 21, and 14%, respectively, of TN output (basin average 270 kg N ha−1 AL year−1, overall output 60 060 t N year−1). N inputs exceeded outputs by 40 056 t N year−1, resulting in a basin average surplus of about 180 kg N ha−1 AL year−1. About 34% of the N surplus was exported annually from the basin while the remaining amount (about 26 800 t N year−1) underwent other unaccounted for processes within the watershed.The relevance of nitrogen removal via denitrification in aquatic compartments within the watershed was evaluated. Denitrification in the secondary drainage network can represent a relevant nitrogen sink due to great linear extension (over 12 500 km), with estimated nitrogen loss up to 8500 t N year−1. Denitrification in the riverbed and in perifluvial wetlands have the potential to remove only a small fraction of the nitrogen surplus (<3%). Evidence suggests the relevance of groundwater as a site of nitrogen accumulation.
Development of Polymeric and Polymer‐Based Hybrid Adsorbents for Chromium Removal from Aqueous Solution
Authors: Kaya Ismet Gul Buyruklardan , Duranoglu Dilek , Beker Ulker , Senkal Bahire Filiz 
Published: October 2011

AbstractFerric oxide‐loaded hybrid sorbents are environmentally benign and exhibit sorption behaviors for chromium removal from waters. In the current study, glycidyl methacrylate‐based polymer (GMD) and nanosized ferric oxide loaded glycidyl methacrylate‐based polymer (GMDFe) were prepared and assayed to examine the effect of ferric oxide loading on chromium sorption from aqueous solution for the first time from the equilibrium and kinetic points of view. The experimental equilibrium data, suitably fitted by the Langmuir and Freundlich isotherms, have shown that ferric oxide loaded hybrid sorbent exhibits higher adsorption capacity than glycidyl methacrylate‐based polymer (GMD). The Langmuir isotherm model was found to be the most suitable one for the Cr(VI) adsorption. The maximum adsorption capacities of GMD and GMDFe sorbents were determined at pH 4 as 109.54 and 157.52 mg/g, respectively. A series of column experiments was carried out to determine the breakthrough curves. The column was regenerated by eluting Cr(VI) using NaOH (10% w/v) solution after adsorption studies.
Prevalence of BRCA mutations in an unselected population of triple‐negative breast cancer
Authors: Hartman Anne‐Renee , Kaldate Rajesh R. , Sailer Lisa M. , Painter Lisa , Grier Charles E. , Endsley Robbin R. , Griffin Marlena , Hamilton Stephanie A. , Frye Cynthia A. , Silberman Mark A. , Wenstrup Richard J. , Sandbach John F. 
Published: October 2011

AbstractBACKGROUND:This study assessed BRCA1 and BRCA2 mutation prevalence in an unselected cohort of patients with triple‐negative breast cancer (BC).METHODS:One hundred ninety‐nine patients were enrolled. Triple negativity was defined as <1% estrogen and progesterone staining by immunohistochemistry and HER‐2/neu not overexpressed by fluorescence in situ hybridization. Having given consent, patients had BRCA1 and BRCA2 full sequencing and large rearrangement analysis. Mutation prevalence was assessed among the triple‐negative BC patients and the subset of patients without a family history of breast/ovarian cancer. Independent pathological review was completed on 50 patients.RESULTS:Twenty‐one deleterious BRCA mutations were identified—13 in BRCA1 and 8 in BRCA2 (prevalence, 10.6%). In 153 patients (76.9%) without significant family history (first‐degree or second‐degree relatives with BC aged <50 years or ovarian cancer at any age), 8 (5.2%) mutations were found. By using prior National Comprehensive Cancer Network (NCCN) guidelines recommending testing for triple‐negative BC patients aged <45 years, 4 of 21 mutations (19%) would have been missed. Two of 21 mutations (10%) would have been missed using updated NCCN guidelines recommending testing for triple‐negative BC patients aged <60 years.CONCLUSIONS:The observed mutation rate was significantly higher (P = .0005) than expected based on previously established prevalence tables among patients unselected for pathology. BRCA1 mutation prevalence was lower, and BRCA2 mutation prevalence was higher, than previously described. Additional mutation carriers would have met new NCCN testing guidelines, underscoring the value of the updated criteria. Study data suggest that by increasing the age limit to 65 years, all carriers would have been identified. Cancer 2011;. © 2011 American Cancer Society.
Comparison of the use and results of sentinel lymph node biopsy in children and young adults with melanoma
Authors: Mu Euphemia , Lange Julie R. , Strouse John J. 
Published: October 2011

AbstractBACKGROUND:Data on sentinel lymph node (SLN) biopsy in children with melanoma are limited. In this study, the authors compared the factors associated with SLN biopsy use and metastases in pediatric and young adult patients with melanoma.METHODS:The 2008 Surveillance, Epidemiology, and End Results (SEER) databases were used to examine melanoma cases from 2003 to 2008. Data extracted include age, sex, race, stage, tumor thickness, ulceration, lymph node status, surgical treatment, and survival. Logistic regression models were used for adjusted analyses.RESULTS:In total, 717 children (age <20 years) and 1368 young adults (age 20‐24 years) were identified who were diagnosed with melanoma. Factors that were associated with SLN biopsy use included tumor ulceration (odds ratio [OR], 2.4; 95% confidence interval [CI], 1.4‐4.3) and greater thickness (OR, 17; 95% CI, 12‐24 for >1 mm vs ≤1 mm), but not younger age (OR, 1.3; 95% CI, 0.94‐1.8) in adjusted analyses. SLN metastasis was correlated with ulceration (OR, 3.0; 95% CI, 1.6‐5.8), increased thickness (OR, 6.8; 95% CI, 3.1‐15 for 2.01‐4.0 mm vs ≤1 mm), and for the interaction between age <20 years and thickness 1.01 to 2.00 mm (OR, 6.5; 95% CI, 1.7‐25) in adjusted analyses. Children with nonulcerated melanomas that measured 1.01 to 2.00 mm in thickness were significantly more likely to have SLN metastases than young adults (24% vs 4%; P < .001).CONCLUSIONS:Thickness and ulceration were strong predictors of both the use of SLN biopsy and positive SLN biopsy results in children and young adults with melanoma. Compared with young adults, children were more likely to have SLN metastases despite having similar rates of SLN biopsy use. Cancer 2011;. © 2011 American Cancer Society.
The use of bevacizumab among women with metastatic breast cancer: A survey on clinical practice and the ongoing controversy
Authors: Dawood Shaheenah , Shaikh Asim Jamal , Buchholz Thomas A. , Cortes Javier , Cristofanilli Massimo , Gupta Sudeep , Gonzalez‐Angulo Ana M. 
Published: October 2011

AbstractBACKGROUND:The US Food and Drug Administration's (FDA's) recent decision to remove the indication of bevacizumab for metastatic breast cancer (MBC) has fueled a debate in the breast cancer community. We conducted a survey to assess the perception of health care workers involved in the management of women with MBC on the FDA's decision to ascertain how it will affect practice and to determine how bevacizumab is commonly used in the community for MBC.METHODS:E‐mails were sent out between September and November 2010 using a database of 3000 addresses maintained by the United Arab Emirates Cancer Congress. Individuals working for Roche or Genentech were excluded. The survey consisted of 22 questions that were divided into 3 parts addressing each participant's demographic profile, their opinion of the FDA's decision, and the typical use of bevacizumab in the community in the setting of MBC.RESULTS:A total of 564 participants were included in the final analysis, contributing to an 18.8% response rate. Of these participants, 14.6% were from the United States, 7.8% were from Canada, 31.1% were from Europe, 2.0% were from the United Arab Emirates, 11.1% were from Asia, and 33.3% were from other countries. The majority of participants believed progression‐free survival to be a surrogate for overall survival, that cost played a role in the FDA's decision, and that the decision would adversely affect the future of newer drugs currently being investigated for MBC. The majority of participants indicated that they would use bevacizumab for triple receptor–negative MBC (46.5%), would use it in a first‐line setting (44.7%), and would use it in combination with paclitaxel (51.9%).CONCLUSION:Our survey results highlight the discord between the opinion of community oncologists and the FDA's recent decision to withdraw the indication of bevacizumab for MBC. Cancer 2011;. © 2011 American Cancer Society.
Dried blood spots (DBS) for doping control analysis
Authors: Thomas Andreas , Geyer Hans , Guddat Sven , Schänzer Wilhelm , Thevis Mario 
Published: October 2011

Whole blood sample collection on cellulose paper has a more than 30‐year‐long tradition, especially in neonatal screening. The sampling is minimally invasive, fast, discreet, and robust against manipulation.The present approach highlights the potential to determine doping agents in dried blood spots (DBS) after extraction and subsequent analysis by liquid chromatography‐mass spectrometry (LC‐MS). The assay is focused on selected model compounds of which the circulating target concentration is of particular interest. Here, pre‐ or post‐competition testing with DBS allows probing for the conditions (i.e. presence or absence of relevant drugs) in the athlete's circulation during competition, which complements earlier approaches towards the identification of urinary indicators for the temporal application of substances prohibited in‐competition only.Precise (< 20%), linear, and robust conditions with limits of detection in low ng/ml range were accomplished by means of LC coupled to high resolution/high accuracy mass spectrometry for the selected model compounds benzoylecgonine, cocaine, pseudoephedrine, amphetamine, salbutamol, and JWH‐018. Deuterium‐labelled internal standards were used to yield reliable quantitative results. In addition, the non‐targeted screening approach (positive/negative switching combined with tandem mass spectrometry (MS/MS) experiments) enables the retrospective qualitative data evaluation for a comprehensive selection of known and unknown substances as exemplarily shown by the extraction of 20 target compounds (corticosteroids, aromatase inhibitors, anabolic steroids, beta‐blockers, etc.) at 20 ng/ml.The simple and fast nature of the assay allows for an easy implementation into existing procedures and will potentially enhance the effectiveness of testing by reducing costs and effort of pre‐analysis workload. Copyright © 2011 John Wiley & Sons, Ltd.
The Muenke syndrome mutation (FgfR3P244R) causes cranial base shortening associated with growth plate dysfunction and premature perichondrial ossification in murine basicranial synchondroses
Authors: Laurita Jason , Koyama Eiki , Chin Bianca , Taylor Jesse A. , Lakin Gregory E. , Hankenson Kurt D. , Bartlett Scott P. , Nah Hyun‐Duck 
Published: October 2011

AbstractMuenke syndrome caused by the FGFR3P250R mutation is an autosomal dominant disorder mostly identified with coronal suture synostosis, but it also presents with other craniofacial phenotypes that include mild to moderate midface hypoplasia. The Muenke syndrome mutation is thought to dysregulate intramembranous ossification at the cranial suture without disturbing endochondral bone formation in the skull. We show in this study that knock‐in mice harboring the mutation responsible for the Muenke syndrome (FgfR3P244R) display postnatal shortening of the cranial base along with synchondrosis growth plate dysfunction characterized by loss of resting, proliferating and hypertrophic chondrocyte zones and decreased Ihh expression. Furthermore, premature conversion of resting chondrocytes along the perichondrium into prehypertrophic chondrocytes leads to perichondrial bony bridge formation, effectively terminating the postnatal growth of the cranial base. Thus, we conclude that the Muenke syndrome mutation disturbs endochondral and perichondrial ossification in the cranial base, explaining the midface hypoplasia in patients. Developmental Dynamics 240:2584–2596, 2011. © 2011 Wiley Periodicals, Inc.
Intratumor OX40 stimulation inhibits IRF1 expression and IL‐10 production by Treg cells while enhancing CD40L expression by effector memory T cells
Authors: Burocchi Alessia , Pittoni Paola , Gorzanelli Andrea , Colombo Mario P. , Piconese Silvia 
Published: October 2011

AbstractTreg cells maintain the tumor microenvironment in an immunosuppressive state preventing an effective anti‐tumor immune response. A possible strategy to overcome Treg‐cell suppression focuses on OX40, a costimulatory molecule expressed constitutively by Treg cells while being induced in activated effector T cells. OX40 stimulation, by the agonist mAb OX86, inhibits Treg‐cell suppression and boosts effector T‐cell activation. Here we uncover the mechanisms underlying the therapeutic activity of OX86 treatment dissecting its distinct effects on Treg and on effector memory T (Tem) cells, the most abundant CD4+ populations strongly expressing OX40 at the tumor site. In response to OX86, tumor‐infiltrating Treg cells produced significantly less interleukin 10 (IL‐10), possibly in relation to a decrease in the transcription factor interferon regulatory factor 1 (IRF1). Tem cells responded to OX86 by upregulating surface CD40L expression, providing a licensing signal to DCs. The CD40L/CD40 axis was required for Tem‐cell‐mediated in vitro DC maturation and in vivo DC migration. Accordingly, OX86 treatment was no longer therapeutic in CD40 KO mice. In conclusion, following OX40 stimulation, blockade of Treg‐cell suppression and enhancement of the Tem‐cell adjuvant effect both concurred to free DCs from immunosuppression and activate the immune response against the tumor.
HIV‐1 infection alters CD4+ memory T‐cell phenotype at the site of disease in extrapulmonary tuberculosis
Authors: Matthews Kerryn , Ntsekhe Mpiko , Syed Faisal , Scriba Thomas , Russell James , Tibazarwa Kemi , Deffur Armin , Hanekom Willem , Mayosi Bongani M. , Wilkinson Robert J. , Wilkinson Katalin A. 
Published: October 2011

AbstractHIV‐1‐infected people have an increased risk of developing extrapulmonary tuberculosis (TB), the immunopathogenesis of which is poorly understood. Here, we conducted a detailed immunological analysis of human pericardial TB, to determine the effect of HIV‐1 co‐infection on the phenotype of Mycobacterium tuberculosis (MTB)‐specific memory T cells and the role of polyfunctional T cells at the disease site, using cells from pericardial fluid and blood of 74 patients with (n=50) and without (n=24) HIV‐1 co‐infection. The MTB antigen‐induced IFN‐γ response was elevated at the disease site, irrespective of HIV‐1 status or antigenic stimulant. However, the IFN‐γ ELISpot showed no clear evidence of increased numbers of antigen‐specific cells at the disease site except for ESAT‐6 in HIV‐1 uninfected individuals (p=0.009). Flow cytometric analysis showed that CD4+ memory T cells in the pericardial fluid of HIV‐1‐infected patients were of a less differentiated phenotype, with the presence of polyfunctional CD4+ T cells expressing TNF, IL‐2 and IFN‐γ. These results indicate that HIV‐1 infection results in altered phenotype and function of MTB‐specific CD4+ T cells at the disease site, which may contribute to the increased risk of developing TB at all stages of HIV‐1 infection.
Synthesis and Electronic Structure of Reduced Bis(imino)pyridine Manganese Compounds
Authors: Russell Sarah K. , Bowman Amanda C. , Lobkovsky Emil , Wieghardt Karl , Chirik Paul J. 
Published: October 2011

AbstractThe synthesis and electronic structure of reduced aryl‐substituted bis(imino)pyridine manganese compounds have been explored. Stirring a THF slurry of [(iPrPDI)MnCl2] {iPrPDI = 2,6‐(2,6‐iPr2–C6H3N=CMe)2C5H3N} with excess Na and catalytic (0.5 mol‐%) naphthalene furnished the bis(THF) compound [(iPrPDI)Mn(THF)2]. Performing the reduction with excess Na(Hg) in toluene furnished the bis(chelate) manganese compound [(iPrPDI)2Mn]. For both compounds, a combination of EPR spectroscopy, magnetic measurements and metrical parameters determined from X‐ray diffraction established high‐spin MnII compounds with reduced, redox‐active bis(imino)pyridine ligands. Substitution of the THF ligands with carbon monoxide yielded [(iPrPDI)Mn(CO)2], a low‐spin MnI, d6 compound with an experimentally observed bis(imino)pyridine‐centred radical. Oxidation and reduction of this compound furnished [(iPrPDI)Mn(CO)3]+ and [(iPrPDI)Mn(CO)2]–, respectively, and provided a series of three manganese carbonyl compounds over three oxidation states. Elucidation of the electronic structure of these compounds established that oxidation events within the series are ligand‐ rather than manganese‐based, most likely a result of the stable low‐spin MnI, d6 electron configuration imparted by the strong‐field carbonyl ligands.
In vitro toxicity and genotoxicity assessment of disinfection by‐products, organic N‐chloramines
Authors: Laingam S. , Froscio S.M. , Bull R.J. , Humpage A.R. 
Published: October 2011

AbstractDisinfection by‐products (DBPs) are of concern to both water industries and health authorities. Although several classes of DBPs have been studied, and there are regulated safe levels in disinfected water for some, a large portion of DBPs are not characterized, and need further investigation. Organic N‐chloramines are a group of DBPs, which can be formed during common disinfection processes such as chlorination and chloramination, but little is known in terms of their toxicological significance if consumed in drinking water. Only a few in vitro studies using bacterial assays have reported some genotoxic potential of organic N‐chloramines, largely in the context of inflammatory processes in the body rather than exposure through drinking water. In this study, we investigated 16 organic N‐chloramines produced by chlorination of model amino acids and amines. It was found that within the drinking water‐relevant micromolar concentration range, four compounds were both cytotoxic and genotoxic to mammalian cells. A small reduction of cellular GSH was also observed in the treatment with these four compounds, but not of a magnitude to account for the cytotoxicity and genotoxicity. The results presented in this study demonstrate that some organic N‐chloramines, at low concentrations that might be present in disinfected water, can be harmful to mammalian cells. © Environ. Mol. Mutagen. 2012. Published 2011 Wiley‐Liss, Inc.
HT‐PEM Fuel Cell System with Integrated Complex Metal Hydride Storage Tank
Authors: Urbanczyk R. , Peil S. , Bathen D. , Heßke C. , Burfeind J. , Hauschild K. , Felderhoff M. , Schüth F. 
Published: October 2011

AbstractA hydrogen storage tank based on the metal hydride sodium alanate is coupled with a high temperature PEM fuel cell (HT‐PEM). The waste heat of the fuel cell is used for desorbing hydrogen from the storage tank that in return feeds the fuel cell. ZBT has developed the HT‐PEM fuel cell, Max‐Planck‐Institut für Kohlenforschung the sodium alanate, and IUTA the hydrogen storage tank. During the experiments of the system the fuel cell was operated by load cycling from 165 up to 240 W. Approximately 60 g of hydrogen were delivered from the tank, which was charged with 2676.8 g of sodium alanate doped with 4 mol.% of TiCl3. This amount of hydrogen was desorbed in 3 h and generated a cumulated electrical energy of 660 Wh. In the first cycle 81.5 g of hydrogen were supplied during 3.69 h to the HT‐PEM fuel cell, which was operated nearly constant at 260 W. In the latter case the cumulated electrical energy was 941 Wh.