bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of functions linking quorum sensing with biofilm formation in Burkholderia cenocepacia H111
Authors: Inhülsen Silja , Aguilar Claudio , Schmid Nadine , Suppiger Angela , Riedel Kathrin , Eberl Leo 
Published: May 2012

AbstractBurkholderia cenocepacia has emerged as an important pathogen for patients suffering from cystic fibrosis (CF). Previous work has shown that this organism employs the CepIR quorum‐sensing (QS) system to control the expression of virulence factors as well as the formation of biofilms. To date, however, very little is known about the QS‐regulated virulence factors and virtually nothing about the factors that link QS and biofilm formation. Here, we have employed a combined transcriptomic and proteomic approach to precisely define the QS regulon in our model strain B. cenocepacia H111, a CF isolate. Among the identified CepR‐activated loci, three were analyzed in better detail for their roles in biofilm development: (i) a gene cluster coding for the BclACB lectins, (ii) the large surface protein BapA, and (iii) a type I pilus. The analysis of defined mutants revealed that BapA plays a major role in biofilm formation on abiotic surfaces while inactivation of the type I pilus showed little effect both in a static microtitre dish‐based biofilm assay and in flow‐through cells. Inactivation of the bclACB lectin genes resulted in biofilms containing hollow microcolonies, suggesting that the lectins are important for biofilm structural development.
Prokaryotic community structure and respiration during long‐term incubations
Authors: Baltar Federico , Lindh Markus V. , Parparov Arkadi , Berman Tom , Pinhassi Jarone 
Published: May 2012

AbstractDespite the importance of incubation assays for studies in microbial ecology that frequently require long confinement times, few reports are available in which changes in the assemblage structure of aquatic prokaryotes were monitored during long‐term incubations. We measured rates of dissolved organic carbon degradation and microbial respiration by consumption of dissolved oxygen (DO) in four experiments with Lake Kinneret near‐surface water and, concomitantly, we analyzed the variability in prokaryotic community structure during long‐term dark bottle incubations. During the first 24 h, there were only minor changes in bacterial community composition. Thereafter there were marked changes in the prokaryotic community structure during the incubations. In contrast, oxygen consumption rates (a proxy for both respiration and dissolved organic carbon degradation rates) remained stable for up to 10–23 days. This study is one of the first to examine closely the phylo‐genetic changes that occur in the microbial community of untreated freshwater during long‐term (days) incubations in dark, sealed containers. Novel information on the diversity of the main bacterial phylotypes that may be involved in dissolved organic matter degradation in lake Kinneret is also provided. Our results suggest that, under certain ecological settings, constant community metabolic rates can be maintained as a result of shifts in community composition.
Outpatient treatment in German adolescents with depression: an analysis of nationwide health insurance data
Authors: Hoffmann Falk , Glaeske Gerd , Petermann Franz , Bachmann Christian J. 
Published: May 2012

ABSTRACTPurposeData on medical treatment of adolescents with depression are scarce. This study aimed to examine outpatient health services utilisation of depressive disorders in adolescents.MethodsData of a statutory health insurance company were analysed and outpatients from 12 to 18 years old with diagnosed depression during a 1‐year period (2009) were identified. For this cohort, the prescription of antidepressants and psychotherapy was evaluated with respect to age and sex.ResultsA total of 4295 patients (41.2% males; mean age, 15.5 years) matched the inclusion criteria. Of the patients, 29.7% consulted a child and adolescent psychiatrist. A total of 59.6% were treated with psychotherapy only, 9.6% were treated with a combination of psychotherapy and antidepressants, and 1.9% received only antidepressants. For 28.8% of patients, no specific depression‐related treatment was prescribed. A total of 1357 packages of antidepressants were analysed, of which fluoxetine (24.4% of prescriptions), citalopram (14.0%), and mirtazapine (9.7%) were the most frequently prescribed substances. Regarding substance classes, selective serotonin reuptake inhibitors (SSRIs; 55.6%), tricyclic antidepressants (TCAs; 17.9%), and hypericum (St. John's wort; 8.5%) were most common.ConclusionsAlthough the underlying data were coded for insurance purposes, which might result in some data impreciseness, this naturalistic study furnishes evidence that outpatient treatment of adolescents with depressive disorders in Germany only partly complies with guideline recommendations for first‐line treatment: Although the prescriptions of SSRI for adolescent depression have risen over recent years, still, a quarter of antidepressant prescriptions for adolescents with depression were TCA or hypericum. Therefore, dissemination of knowledge on state‐of‐the‐art treatment for adolescent depression remains a major educational goal. Copyright © 2012 John Wiley & Sons, Ltd.
In situ synthesis of polybutene‐1/polypropylene spherical alloys within a reactor with an MgCl2‐supported Ziegler–Natta catalyst
Authors: He Aihua , Zheng Weiping , Shi Yangwei , Liu Guoqing , Yao Wei , Huang Baochen 
Published: May 2012

AbstractA series of isotactic polybutene‐1/polypropylene (PB/PP) alloys with spherical morphology were prepared by MgCl2‐supported Ziegler‐Natta catalyst with sequential two‐stage polymerization technology. The first formed PP particles were used as micro‐reactors to initiate the bulk precipitation polymerization of butene‐1 further. The porous PP particles as a hard framework may prevent the adhesion of PB particles during the bulk precipitation polymerization process. At the same time, the bulk precipitation polymerization process allows for maximization of the butene‐1 polymerization rate and simplifies the butene‐1 polymerization process considerably. Finally, spherical PB alloys with a super‐high molecular weight PB component and adjustable PP component were synthesized in situ within the reactor. The structures and properties of the PB/PP alloys were characterized by gel permeation chromatography, 13C nuclear magnetic resonance, Fourier transform IR, scanning electron microscopy, differential scanning calorimetry and X‐ray diffraction. The results showed that the MgCl2‐supported Ziegler‐Natta catalyst showed relatively high stereospecificity and efficiency for both propylene and butene‐1 polymerization. The incorporation of propylene on the PB matrix affects the properties of the final products markedly. The PB/PP alloys are expected to have a broader range of applications as a new family of high performance materials. Copyright © 2012 Society of Chemical Industry
Influence of media polarity on the rate of activation of “dormant” chains in nitroxide‐mediated radical polymerization
Authors: Zaremski Mikhail , Borisova Olga , Xin Chen , Golubev Vladimir B. , Billon Laurent 
Published: May 2012

AbstractRate constants of decomposition of “living” polymeric adducts polystyrene (PS)‐TEMPO, poly‐4‐vinylpyridine‐TEMPO, PS‐SG1, and polyacrylic acid‐SG1 in different solvents were determined by the method of a competitive inhibition by means of electron spin resonance. It was found that with the increase in polarity of solvent, the values of constants become higher for all systems studied. This effect opens a new way of activating chains in nitroxide‐mediated radical polymerization. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Controlled polymerization of methyl acrylate for high‐molecular‐weight polymers by pentafluorophenylbis(triflyl)methane‐promoted group transfer polymerization using triisopropylsilyl ketene acetal
Authors: Takada Kenji , Fuchise Keita , Chen Yougen , Satoh Toshifumi , Kakuchi Toyoji 
Published: May 2012

AbstractThe group transfer polymerization (GTP) of methyl acrylate (MA) was studied using pentafluorophenylbis(triflyl)methane (C6F5CHTf2) as the organocatalyst and 1‐trimethylsiloxy‐, 1‐triethylsiloxy‐, and 1‐triisopropylsiloxy‐1‐methoxy‐2‐methyl‐1‐propene (MTSMe, MTSEt, and MTSiPr, respectively) as the initiators. The C6F5CHTf2‐promoted GTP of MA using MTSiPr proceeded in a living nature to produce poly(methyl acrylate)s (PMAs) with controlled molecular weights and narrow molecular weight distributions, which allowed the synthesis of high‐molecular‐weight PMA with the number‐average molecular weight (Mn(SEC)) of up to 108,000 and the polydispersity (Mw/Mn) of 1.07. The matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry measurement revealed that the obtained PMA possessed the chain end structure that originated from MTSiPr, showing that the C6F5CHTf2‐promoted GTP of MA proceeded without any side reactions. In addition, the kinetic study and the postpolymerization experiment supported the living manner of the polymerization. Moreover, the block copolymerization of MA and n‐butyl acrylate (nBA) smoothly proceeded to afford the well‐defined PMA‐block‐poly(n‐butyl acrylate) (PnBA). © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Preparation of chiral amino acid materials and the study of their interactions with 1,1‐Bi‐2‐naphthol
Authors: Moore Beth L. , O'Reilly Rachel K. 
Published: May 2012

AbstractThe amino acid tryptophan has been converted into acrylamide monomers using L/D‐tryptophan methyl ester forming the enantiopure chiral monomers. Attempts were made to polymerize these monomers via reversible addition fragmentation chain transfer (RAFT) polymerization to form poly(tryptophan). Unfortunately, this proved difficult, and instead, a postpolymerization modification route was used by first synthesizing poly(pentafluorophenyl acrylate) via RAFT, which was then substituted with L‐tryptophan methyl ester to give poly(L‐tryptophan). The interactions of the newly synthesized tryptophan monomers, as well as previously reported phenylalanine monomers, were studied in the presence of rac‐BINOL. It has been shown that the enantiomers of tryptophan have a stronger interaction with BINOL than phenylalanine and this has been attributed to the larger π system on the side chain. By monitoring the shifts and splitting of the phenolic protons of BINOL, it has been observed that S‐BINOL interacts more favorably with L‐monomer enantiomers and R‐BINOL with D‐monomer enantiomers. Similar interactions have also been seen with poly(phenylalanine) and the newly synthesized poly(tryptophan) materials. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
pH‐responsive polyphosphonates using butler's cyclopolymerization
Authors: Al‐Hamouz Othman Charles S. , Ali Shaikh A. 
Published: May 2012

AbstractThe cationic monomer, N,N‐diallyl‐(diethylphosphonato)methylammonium chloride, and zwitterionic monomer, ethyl 3‐(N,N‐diallylammonio)methanephosphonate, were cyclopolymerized in aqueous solutions using ammonium persulfate or t‐butylhydroperoxide as initiators to afford a cationic polyelectrolyte (CPE) and a polyzwitterion ester (PZE), respectively. The CPE and PZE on acidic hydrolysis of the ester functionalities afforded the same polyzwitterionic acid (PZA): poly[3‐(N,N‐diallylammonio)methanephosphonic acid]. The solution properties of the CPE, pH‐responsive PZE, and PZA were studied in detail by potentiometric and viscometric techniques. Basicity constants of the phosphonate (PO(OEt)O−) and amine groups in the PZE and in the conjugate base of the PZE, respectively, were found to be “apparent” and as such follow the modified Henderson–Hasselbalch equation. In contrast to many polycarbobetaines and sulfobetaines, PZE was found to be soluble in salt‐free water as well as salt (including Ca2+, Li+)‐added solutions, and demonstrated “antipolyelectrolyte” solution behavior. The PZA, on the other hand, was found to be insoluble in salt‐free water, and on treatment with NaOH gave dianionic polyelectrolyte (DAPE) containing trivalent nitrogen and [PO(O)22−] groups. For the first time, several new phase diagrams of polyethylene glycol‐DAPE aqueous two‐phase systems (ATPSs) have been constructed in the presence of varying proportions of HCl. The ATPSs may find application in affinity partitioning of metal ions because DAPE is expected to be an effective chelator. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Star‐shaped polymers having side chain poss groups for solid polymer electrolytes; synthesis, thermal behavior, dimensional stability, and ionic conductivity
Authors: Kim Dong‐Gyun , Sohn Hae‐Sung , Kim Sung‐Kon , Lee Aeri , Lee Jong‐Chan 
Published: May 2012

AbstractA series of organic/inorganic hybrid star‐shaped polymers were synthesized by atom transfer radical polymerization using 3‐(3,5,7,9,11,13,15‐heptacyclohexyl‐pentacyclo[9.5.1.13,9.15,15.17,13]‐octasiloxane‐1‐yl)propyl methacrylate (MA‐POSS) and poly(ethylene glycol) methyl ether methacrylate (PEGMA) as monomers and octakis(2‐bromo‐2‐methylpropionoxypropyldimethylsiloxy)octasilsesquioxane as an initiator. Star‐shaped polymers with methyl methacrylate (MMA) and PEGMA moieties were also prepared for comparison purposes. Dimensionally stable freestanding film could be obtained from the hybrid star‐shaped polymer containing 26 wt % of MA‐POSS moieties although its glass transition temperature is very low, −60.9 °C. As a result, the hybrid star‐shaped polymer electrolyte containing lithium bis(trifluoromethanesulfonyl)imide showed ionic conductivities (1.75 × 10−5 S/cm at 30 °C), which were two orders of magnitude higher than those of the star‐shaped polymer electrolyte with MMA moieties. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Synthesis and Fe(III)‐complexation ability of polyurethane bearing kojic acid skeleton in the main chain prepared by polyaddition of aliphatic hydroxyl groups without protection of phenolic hydroxyl groups
Authors: Ochiai Bungo , Kamiya Miyuki , Endo Takeshi 
Published: May 2012

AbstractPolyaddition of a kojic acid dimer and diisocyanates yielded polyurethane with metal‐coordination ability owing to the phenolic hydroxyl groups of kojic acid. Although the kojic acid dimer contains two phenolic and two aliphatic hydroxyl groups, 1,5‐diazabicyclo[4.3.0]non‐5‐ene catalyzed polymerization proceeded through highly selective reactions of the aliphatic hydroxyl groups without any protection of the phenolic hydroxyl groups. The resulting polymers complexed with FeCl3, and specific colorizations were observed. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Meanings of happiness among two ethnic groups living with advanced cancer in south London: a qualitative study
Authors: Koffman Jonathan , Morgan Myfanwy , Edmonds Polly , Speck Peter , Siegert Richard , Higginson Irene J. 
Published: May 2012

AbstractObjectiveHappiness is a central component in quality of life but little is known about its meanings among people living with an advanced disease and those from diverse communities. This study explores and compares, for the first time, the centrality and interpretations of happiness across two cultural groups living with advanced cancer.MethodsSemi‐structured interviews among 26 Black Caribbean and 19 White British cancer patients were conducted in hospital and home settings.ResultsThirty eight participants volunteered views on happiness, which were related to four main themes: empty lives, a theme associated with lives devoid of contentment; happiness and the physical form principally, associated with the absence of distressing symptoms; ‘love and affection’ associated with family and friends; and ‘realising personal meaning in life’, most common among the Black Caribbean participants and related to God, prayer and the sacred world. The presence of cancer pain even when refractory did not preclude manifestations of happiness in this domain.ConclusionsWe identified that happiness was central to many patients' quality of life during advanced cancer. Moreover, happiness was multidimensional and at times culturally patterned. We recommend that health and social care professionals increase their awareness and skills‐set in relation to exploring happiness. Further, we recommend greater efforts are invested in cultural relativism to service the physical, psychological, social and spiritual issues that contribute towards moments of happiness among diverse communities. Copyright © 2012 John Wiley & Sons, Ltd.
Breaking bad news in China – the dilemma of patients' autonomy and traditional norms. A first communication skills training for Chinese oncologists and caretakers
Authors: Wuensch Alexander , Tang Lilli , Goelz Tanja , Zhang Yening , Stubenrauch Sara , Song Lili , Hong Ye , Zhang Haiwei , Wirsching Michael , Fritzsche Kurt 
Published: May 2012

AbstractObjectiveCurrent practice of breaking bad news in China involves disclosure of information first to family members who then decide whether the patient should receive this information. Recently, however, patients' right to be informed has been regulated by law. This represents a dilemma for oncologists who now have to balance traditional practice with new legal requirements. A communication skills training (CST) was developed for Chinese practice. It addresses this issue and may help participants find individual solutions within these conflicting requirements.MethodsA first CST about breaking bad news took place at the Beijing Cancer Hospital, China, with 31 participants. We (i) assessed current practice, (ii) evaluated the workshop and (iii) self‐assessed performance ratings about breaking bad news before and after the workshop with the help of questionnaires.Results(i) Participants stated that in most cases (78%), they inform family members first. Contrary to this practice, participants think that about 75% of patients would like to be informed first, independent of family. (ii) Overall, the workshop received a very good rating (M = 1.2; scale between 1 and 6). (iii) After the workshop, the participants rated their performance significantly higher in all areas, for example, talking about diagnosis, prognosis and death with the patient and the family.ConclusionsThe CST showed high acceptance and led to significantly improved performance ratings of participating physicians in many areas. It helped participants deal with conflicting demands. For future trainings, further socio‐cultural adaptations are needed. Obvious conflicts still exist and need to be resolved. Copyright © 2012 John Wiley & Sons, Ltd.
Development and validation of a rapid multi‐biomarker liquid chromatography/tandem mass spectrometry method to assess human exposure to mycotoxins
Authors: Warth Benedikt , Sulyok Michael , Fruhmann Philipp , Mikula Hannes , Berthiller Franz , Schuhmacher Rainer , Hametner Christian , Abia Wilfred Angie , Adam Gerhard , Fröhlich Johannes , Krska Rudolf 
Published: May 2012

RATIONALEMycotoxins regularly occur in food worldwide and pose serious health risks to consumers. Since individuals can be exposed to a variety of these toxic secondary metabolites of fungi at the same time, there is a demand for proper analytical methods to assess human exposure by suitable biomarkers.METHODSThis study reports on the development of a liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI‐MS/MS) method for the quantitative measurement of 15 mycotoxins and key metabolites in human urine using polarity switching. Deoxynivalenol (DON), DON‐3‐O‐glucuronide, DON‐15‐O‐glucuronide (D15GlcA), de‐epoxy DON, nivalenol (NIV), T‐2 toxin, HT‐2 toxin, zearalenone, zearalenone‐14‐O‐glucuronide, α‐ and β‐zearalenol, fumonisins B1 and B2 (FB1, FB2), ochratoxin A (OTA) and aflatoxin M1 (AFM1) were determined without the need for any cleanup using a rapid and simple dilute and shoot approach.RESULTSValidation was performed in the range of 0.005–40 µg L–1 depending on the analyte and expected urinary concentration levels. Apparent recoveries between 78 and 119% and interday precisions of 2–17% relative standard deviation (RSD) were achieved. The applicability of the method was demonstrated by the analysis of urine samples obtained from Cameroon. In naturally contaminated urine samples up to six biomarkers of exposure (AFM1, DON, D15GlcA, NIV, FB1, and OTA) were detected simultaneously.CONCLUSIONSWe conclude that the developed LC/MS/MS method is well suited to quantify multiple mycotoxin biomarkers in human urine down to the sub‐ppb range within 18 min and without any prior cleanup. The co‐occurrence of several mycotoxins in the investigated samples clearly emphasizes the great potential and importance of this method to assess exposure of humans and animals to naturally occurring mycotoxins. Copyright © 2012 John Wiley & Sons, Ltd.
Quantitative analysis of pharmaceutical drug distribution in multiple organs by imaging mass spectrometry
Authors: Takai Nozomi , Tanaka Yukari , Inazawa Kazuhiro , Saji Hideo 
Published: May 2012

RATIONALERecently, the requirement for a quantitative research method using imaging mass spectrometry (IMS) to be developed has been discussed. Specifically, the simultaneous quantification of a drug in multiple organs by using whole‐body sections could be insightful for the pharmaceutical industry in the study of drug distribution.METHODSFrozen whole‐body sections were obtained from mice injected with raclopride, a dopamine D2 receptor selective antagonist, and coated with a matrix‐assisted laser desorption/ionization (MALDI) matrix compound. The whole‐body sections were then analyzed using a linear ion trap mass spectrometer equipped with a MALDI source. The concentration of raclopride in each tissue was determined using liquid chromatography/tandem mass spectrometry (LC/MS/MS).RESULTSThe IMS‐based signal intensity of raclopride strongly correlated with the concentration of the drug in the tissue samples (R = 0.94; p <0.001) of six different organs. Furthermore, the spatial information obtained by IMS was very similar to that obtained by autoradiography, which is a traditional technique used for the study of drug distribution.CONCLUSIONSThis study suggests that IMS enables the quantitative analysis of drug distribution in multiple organs simultaneously. In addition, it enhances ideal drug candidate selection in terms of efficient evaluations. Copyright © 2012 John Wiley & Sons, Ltd.