bluuebunny/crossref_metadata_2025_split huggingface dataset:
Critical conditions for ferric chloride‐induced flocculation of freshwater algae
Authors: Wyatt Nicholas B. , Gloe Lindsey M. , Brady Patrick V. , Hewson John C. , Grillet Anne M. , Hankins Matthew G. , Pohl Phillip I. 
Published: September 2011

AbstractThe effects of algae concentration, ferric chloride dose, and pH on the flocculation efficiency of the freshwater algae Chlorella zofingiensis can be understood by considering the nature of the electrostatic charges on the algae and precipitate surfaces. Two critical conditions are identified which, when met, result in flocculation efficiencies in excess of 90% for freshwater algae. First, a minimum concentration of ferric chloride is required to overcome the electrostatic stabilization of the algae and promote bridging of algae cells by hydroxide precipitates. At low algae concentrations, the minimum amount of ferric chloride required increases linearly with algae concentration, characteristic of flocculation primarily through electrostatic bridging by hydroxide precipitates. At higher algae concentrations, the minimum required concentration of ferric chloride for flocculation is independent of algae concentration, suggesting a change in the primary flocculation mechanism from bridging to sweep flocculation. Second, the algae must have a negative surface charge. Experiments and surface complexation modeling show that the surface charge of C. zofingiensis is negative above a pH of 4.0 ± 0.3 which agrees well with the minimum pH required for effective flocculation. These critical flocculation criteria can be extended to other freshwater algae to design effective flocculation systems. Biotechnol. Bioeng. 2012; 109:493–501. © 2011 Wiley Periodicals, Inc.
Systematic review of perianal implants in the treatment of faecal incontinence
Authors: Hussain Z I , Lim M , Stojkovic S G 
Published: September 2011

AbstractBackgroundInjectable bulking agents have been used with varying success for the treatment of faecal incontinence. This systematic review aimed to investigate the various injectable agents and techniques used for the treatment of faecal incontinence, and to assess their safety and efficacy.MethodsThirty-nine publications were identified and studied. The following variables were pooled for univariable analysis: type, location, route of bulking agents, and the use of ultrasound guidance, antibiotics, laxatives and anaesthetics. Predictors of the development of complications and successful outcomes were identified by multivariable logistic regression analysis.ResultsA total of 1070 patients were included in the analysis. On multivariable analysis, the only significant predictor of the development of complications was the route of injection of bulking agents (odds ratio 3·40, 95 per cent confidence interval 1·62 to 7·12; P = 0·001). Two variables were significant predictors of a successful short-term outcome: the use of either PTQ® (OR 5·93, 2·21 to 16·12; P = 0·001) or Coaptite® (OR 10·74, 1·73 to 65·31; P = 0·001) was associated with a greater likelihood of success. Conversely, the use of local anaesthetic was associated with a lower likelihood of success (OR 0·18, 0·05 to 0·59; P = 0·005). Failure to use laxatives in the postoperative period resulted in a poorer medium- to longer-term outcome (OR 0·13, 0·06 to 0·25; P = 0·001).ConclusionThis systematic review has identified variations in the practice of injection of bulking agents that appear to influence the likelihood of complications and affect the outcomes after treatment.
Development of a sensitive liquid chromatography/tandem mass spectrometry method for the determination of fenofibric acid in rat plasma
Authors: Wang Guanxiong , Guo Jifen , Meng Fanhua , Song Xiaomei , Zhong Bohua , Zhao Yimin 
Published: September 2011

ABSTRACTA rapid and sensitive LC‐MS/MS method for the quantification of fenofibric acid in rat plasma was developed and validated. Plasma samples were prepared by liquid–liquid extraction with a mixture of N‐hexane–dichloromethane–isopropanol (100:50:5, v/v/v). Isocratic chromatographic separation was performed on a reversed‐phase Discovery C18 column (2.1 × 50 mm, 5 µm). The mobile phase was methanol–water–formic (75:25:0.25, v/v/v). Detection of fenofibric acid and the internal standard (IS) diclofenac acid was achieved by ESI MS/MS in the negative ion mode using m/z 317 → m/z 213 and m/z 294 → m/z 250 transitions, respectively. The method was linear from 0.005 to 1.250 µg/mL when 100 μL plasma was analyzed. The lower limit of quantification was 0.005 µg/mL. The intra‐ and inter‐day precision values were below 8.2%, and accuracy ranged from −0.9 to 2.1% in all quality control samples. The recovery was 90.3–94.7% and 83.3% for fenofibric acid and IS, respectively. Total run time for each sample analysis was 2.5 min. The validated method was successfully applied to a pharmacokinetic study in six rats after oral administration of fenofibrate, the ester prodrug of fenofibric acid (equivalent to fenofibric acid 5 mg/kg). The method permits laboratory scientists with access to the appropriate instrumentation to perform rapid fenofibric acid determination. Copyright © 2011 John Wiley & Sons, Ltd.
Quantification of leonurine, a novel potential cardiovascular agent, in rat plasma by liquid chromatography–tandem mass spectrometry and its application to pharmacokinetic study in rats
Authors: Zhu Qing , Cai Weimin , Sha Xianyi , Ma Guo , Zheng Yuanting , Shi Xueru , Zhu Yizhun 
Published: September 2011

ABSTRACTLeonurine (SCM‐198), an alkaloid from Herba Leonuri, has been suggested as a novel cardiovascular agent by pharmacology studies in preclinical stage. In present study, we report a simple, rapid and sensitive high‐performance liquid chromatography–tandem mass spectrometry method (HPLC‐MS/MS) for determination of leonurine in rat plasma. Leonurine and its internal standard (IS) n‐benzoyl‐l‐arginine ethyl ester (BAEE) were extracted from plasma samples by one‐step protein precipitation with perchloric acid. Chromatographic separation was performed on an Agilent Zorbax SB‐C18 column (150 × 2.1 mm, 5 µm) using an isocratic elution with acetonitrile–ammonium acetate buffer (10 mm, pH 4.0; 25:75, v/v) as mobile phase at a flow rate of 0.2 mL/min. Analytes were detected by tandem mass spectrometry in positive electrospray ionization (ESI) mode using multiple reaction monitoring (MRM) with the transitions of m/z 312.3 → 181.1 for leonurine and m/z 307.2 → 104.6 for IS. The calibration curves were linear over the range of 4–256 ng/mL with a lower limit of quantitation (LLOQ) of 4 ng/mL. The intra‐ and inter‐day assay precision (as relative standard deviation) were <15%, except which at LLOQ were <20%, with accuracy in the range 98.73‐105.42%. The validated HPLC‐MS/MS method was successfully applied to the pharmacokinetic study in rats following oral administration of leonurine. Copyright © 2011 John Wiley & Sons, Ltd.
Perfusion 123IMP‐SPECT shows reversible abnormalities in GABAB receptor antibody associated encephalitis with normal MRI
Authors: Ohta Kouichi , Seki Morinobu , Dalmau Josep , Shinohara Yukito 
Published: September 2011

AbstractA new subtype of autoimmune encephalitis associated with antibodies against GABAB receptor was recently identified. Although immune‐mediated functional abnormalities are suggested for the pathogenesis, functional brain imaging such as perfusion SPECT has not been documented. A 62‐year‐old woman with anti‐GABAB receptor associated encephalitis underwent 123I‐IMP SPECT in the beginning and after methylprednisolone pulse therapy. Three‐dimensional stereotactic surface projection analysis was used to evaluate the cortical distribution of perfusion abnormality. The patient presented with clinical features of subacute limbic encephalitis. Antibodies to GABAB receptor were identified in her serum and cerebrospinal fluid (CSF), but no tumor was detected. Despite normal magnetic resonance imaging (MRI) findings, the first SPECT revealed hypoperfusion of the frontal, parietal and medial temporal lobes, as well as thalamus, and cerebellum. These areas are known to contain high levels of GABAB receptors. In contrast, the SPECT revealed hyperperfusion in the motor strip and left temporal lobe, which are areas related to some of the patient's symptoms, including seizures, orolingual dyskinesia, and Wernicke aphasia. After treatment with pulses of methylprednisolone, the neuropsychiatric symptoms resolved and the SPECT findings showed substantial improvement in most of these regions. In conclusion, the findings suggest that immunotherapy improved the cortical dysfunction mediated by GABAB receptor antibodies.
Characterization and feasibility of a miniaturized stirred tank bioreactor to perform E. coli high cell density fed‐batch fermentations
Authors: Ali Shaukat , Perez‐Pardo Miguel Angel , Aucamp Jean P. , Craig Alan , Bracewell Daniel G. , Baganz Frank 
Published: September 2011

AbstractThe use of small scale bioreactors that are mechanically and functionally similar to large scale reactors is highly desirable to accelerate bioprocess development because they enable well‐defined scale translations. In this study, a 25‐mL miniaturized stirred tank bioreactor (MSBR) has been characterized in terms of its power input, hydrodynamics, and volumetric oxygen transfer coefficient (kLa) to assess its potential to grow high cell density (HCD) cultures using adequate scale‐down criteria. Engineering characterization results show scale down, based on matched specific power input (PG/V), is feasible from a 20‐L pilot scale stirred tank bioreactor. Results from fed‐batch fermentations performed using Fab′ producing E. coli W3110 at matched (PG/V) in the MSBR and 20‐L STR demonstrated that the MSBR can accurately scale down the 20‐L fermentation performance in terms of growth and Fab′ production. Successful implementation of a fed‐batch strategy in the MSBR resulted in maximum optical density of ca. 114 and total Fab′ concentration of 940 μg/mL compared with ca. 118 and 990 μg/mL in 20‐L STR. Furthermore, the use of the MSBR in conjunction with primary recovery scale‐down tools to assess the harvest material of both reactors showed comparable shear sensitivity and centrifugation performance. The conjoint use of the MSBR with ultra scale‐down (USD) centrifugation mimics can provide a cost‐efficient manner in which to design and develop bioprocesses that account for good upstream performance as well as their manufacturability downstream. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2012
Controlled Synthesis and Characterization of Highly Dispersed Molybdenum Oxide Supported on Silica SBA‐15
Authors: Thielemann Jörg P. , Weinberg Gisela , Hess Christian 
Published: September 2011

AbstractSilica‐supported molybdenum oxide catalysts with high densities of disperse molybdenum oxide species of up to 3.5 atoms nm−2 were prepared by using a novel synthesis approach on the basis of functionalized mesoporous SBA‐15. As revealed by using Raman spectroscopy and thermal analysis, the synthesis mechanism consists of an ion exchange of heptamolybdate ions (Mo7O246−) into the porous functionalized framework and decomposition of the intact precursor into smaller fragments during final calcination. The amount of dispersed molybdenum oxide as well as the ratio of dispersed to crystalline molybdenum oxide was determined in detail for Mo densities of 0–13.0 atoms nm−2 by using a combination of X‐ray fluorescence (XRF), energy‐dispersive X‐ray analysis (EDX), and Raman spectroscopy. Up to 3.5 atoms nm−2 dehydrated molybdenum oxide is present exclusively as dispersed species. At higher densities, additional Mo is introduced as crystalline MoO3, and the amount of dispersed species remains unchanged. The structure of the supported molybdenum oxide under ambient conditions largely resembles that of heptamolybdate ions. Dehydration leads to the formation of grafted monomeric and connected molybdenum oxide surface species. Detailed X‐ray photoelectron spectroscopy (XPS) analysis revealed an increase in the Mo/Si ratio as well as a positive binding energy shift upon dehydration, indicative of an increase in the dispersion of the supported molybdenum oxide. The combination of Raman and XPS analyses establishes a correlation of the changes in structure and dispersion of the supported molybdenum oxide species.
Synthesis, Structure, and Physical Properties of a Partial π‐Stacked Phenalenyl‐Based Neutral Radical Molecular Conductor
Authors: Sarkar Arindam , Itkis Mikhail E. , Tham Fook S. , Haddon Robert C. 
Published: September 2011

AbstractWe report the synthesis, crystallization, and solid‐state characterization of the 3,7‐ethoxy‐substituted spirobiphenalenyl‐boron neutral radical 22. The radical is distinguished by its low disproportionation energy and one‐dimensional structure. We show that our strategy of substitution of OEt group at the active positions of the phenalenyl units changes the crystal packing from its previously known OMe analogue and the solid‐state properties are dictated by the partial π‐stack structure and the oxygen atoms at the 3,7‐positions and can be best rationalized in terms of the resonating valence bond model. Magnetic susceptibility measurements show that in the solid state the radical remains paramagnetic but there is significant spin–spin interaction between the molecules. Band structure calculations reflect efficient overlap between the molecules along the π stack and show evidence of interactions between the spin‐bearing oxygen atoms. The room temperature electrical conductivity (σRT=2.0×10−2 S cm−1) of 22 is higher than that observed in previously known one‐dimensional phenalenyl radicals.
Efficient Complexation of Pyrrole‐Bridged Dizinc(II) Bisporphyrin with Fluorescent Probe Pyrene: Synthesis, Structure, and Photoinduced Singlet–Singlet Energy Transfer
Authors: Chaudhary Arvind , Rath Sankar Prasad 
Published: September 2011

AbstractA diethylpyrrole‐bridged dizinc(II) bisporphyrin (Zn2DEP) is reported that encapsulates fluorescent probe pyrene molecules through strong π–π interactions, which can relay information about the chemical environment in the interior of the host–guest supramolecular assembly. X‐ray structures of both Zn2DEP and the encapsulated pyrene complex are reported, which provides a rare opportunity to investigate the structural changes upon guest binding. A comparative structural analysis demonstrated the exceptional ability of this bisporphyrin platform to open its binding pocket for pyrene encapsulation by a vertical displacement of more than 2.45 Å, although both Zn2DEP and the pyrene complex have nearly parallel porphyrin ring orientations. The 1H NMR spectrum of the encapsulated pyrene complex in solution shows the upfield shifts of the pyrene protons due to a strong ring current effect, which demonstrates the retention of the solid‐state structure in solution. To further assess the extent to which pyrene guests remain encapsulated in solution, a known fluorescence quencher, dimethylaniline, was added to the host–guest assembly, which shows no exciplex formation for days in nonpolar solvents. Thus, the assembly also retained the structural integrity in solution for a long time. The association constant (Kasso) for such a complexation process in solution was observed to be 1.78×105 M−2 for 1:2 binding. Steady‐state fluorescence and lifetime studies indicate significant photoinduced singlet–singlet energy transformation from the excited state of pyrene to zinc bisporphyrin.
Zinc(II) Complexes of Ubiquitin: Speciation, Affinity and Binding Features
Authors: Arena Giuseppe , Fattorusso Roberto , Grasso Giuseppe , Grasso Giuseppa Ida , Isernia Carla , Malgieri Gaetano , Milardi Danilo , Rizzarelli Enrico 
Published: September 2011

AbstractIntraneuronal inclusions consisting of hypermetallated, (poly‐)ubiquitinated proteins are a hallmark of neurodegeneration. To highlight the possible role played by metal ions in the dysfunction of the ubiquitin–proteasome system, here we report on zinc(II)/ubiquitin binding in terms of affinity constants, speciation, preferential binding sites and effects on protein stability and self‐assembly. Potentiometric titrations allowed us to establish that at neutral pH only two species, ZnUb and Zn2Ub, are present in solution, in line with ESI‐MS data. A change in the diffusion coefficient of ubiquitin was observed by NMR DOSY experiments after addition of ZnII ions, and thus indicates metal‐promoted formation of protein assemblies. Analysis of 1H, 15N, 13Cα and 13CO chemical‐shift perturbation after equimolar addition of ZnII ions to ubiquitin outlined two different metal‐binding modes. The first involves a dynamic equilibrium in which zinc(II) is shared between a region including Met1, Gln2, Ile3, Phe4, Thr12, Leu15, Glu16, Val17, Glu18, Ile61 and Gln62 residues, which represent a site already described for copper binding, and a domain comprising Ile23, Glu24, Lys27, Ala28, Gln49, Glu51, Asp52, Arg54 and Thr55 residues. A second looser binding mode is centred on His68. Differential scanning calorimetry evidenced that addition of increasing amounts of ZnII ions does not affect protein thermal stability; rather it influences the shape of thermograms because of the increased propensity of ubiquitin to self‐associate. The results presented here indicate that ZnII ions may interact with specific regions of ubiquitin and promote protein–protein contacts.
Conjugated 4‐Methoxybipyrrole Thiophene Azomethines: Synthesis, Opto‐Electronic Properties, and Crystallographic Characterization
Authors: Tshibaka Tshitundu , Bishop Sophie , Roche Ivan Ulliel , Dufresne Stéphane , Lubell William D. , Skene William G. 
Published: September 2011

AbstractIn the search of functional materials with improved electrochromic properties, thiophenes and asymmetric bipyrroles have been conjugated with azomethine units. 4‐Methoxy‐2,2′‐bipyrroles 3–6 were first synthesized by a general route from 4‐hydroxyproline and converted subsequently to dialdehydes 8–15, which underwent condensations with different aminothiophenes to provide azomethine conjugates 14–18 and 20–22. The crystallization and X‐ray analysis of 20 showed the heterocycles and azomethine bonds were all co‐planar with the heterocycles adopting an anti‐parallel arrangement. These configurations result in extended conjugation and enhanced opto‐electronic properties of the azomethines. Oxidation potential (Epa) was tailored by modification of the substitution pattern of the terminal thiophenes and central pyrroles of the azomethines. The combined low Epa and extended azomethine degree of conjugation resulted in stark color transitions occurring between their neutral and oxidized states. Reversible color formation was induced both electrochemically and by doping/de‐doping with trifluoroacetic acid/triethylamine.
ChemInform Abstract: Synthesis and Evaluation of a Broad Range of New Chiral Phosphine—Carbene Ligands for Asymmetric Hydrogenation.
Authors: Passays Johan , Ayad Tahar , Ratovelomanana‐Vidal Virginie , Gaumont Anne‐Claude , Jubault Philippe , Leclerc Eric 
Published: September 2011

AbstractThe novel catalysts of the type (I) are synthesized on a gram scale and applied in the hydrogenation of dehydroamino acids (II) and methylstilbene (IV).
ChemInform Abstract: Magnetically Recoverable Osmium Catalysts for Dihydroxylation of Olefins.
Authors: Fujita Ken‐ichi , Umeki Satoshi , Yamazaki Manabu , Ainoya Taku , Tsuchimoto Teruhisa , Yasuda Hiroyuki 
Published: September 2011

AbstractA magnetically recoverable osmium catalyst is prepared by use of magnetite, quaternary ammonium salt, and potassium osmate(VI) and applied to the dihydroxylation of olefins.
ChemInform Abstract: MOM‐, MEM‐ and SEM‐Phenyl Selenides as Reagents for the Protection of Alcohols as Alkoxymethyl Ethers.
Authors: Temperini Andrea , Annesi Diego , Testaferri Lorenzo , Tiecco Marcello 
Published: September 2011

AbstractActivation of Mom‐, Mem‐, and Sem‐phenyl selenides by iodonium or Cu(I) ions in the presence of alcohols (I), (IV), (VII), and (IX) affords to corresponding alkoxymethyl ethers (III), (VI), (VIII), and (XI), respectively, in good yields.
ChemInform Abstract: Ruthenium‐Catalyzed Regio‐ and Stereoselective Addition of Carboxylic Acids to Aryl and Trifluoromethyl Group Substituted Unsymmetrical Internal Alkynes.
Authors: Kawatsura Motoi , Namioka Junya , Kajita Koji , Yamamoto Mitsuaki , Tsuji Hiroaki , Itoh Toshiyuki 
Published: September 2011

AbstractThe reaction proceeds with complete (E)‐selectivity.
ChemInform Abstract: tBuOLi‐Mediated Alkynylation of Aldehydes.
Authors: Li Chuanbin , Li Xiaolong , Meng Xu , Wang Tiansheng , Li Jihui , Chen Baohua 
Published: September 2011

AbstractA simple and efficient method for the preparation of propargylic alcohols (III) (23 examples) is described.
ChemInform Abstract: Ceric Ammonium Nitrate Mediated Oxidative Dimerization of 1‐Methoxy Naphthalene.
Authors: Ramchander J. , Reddy A. Ram 
Published: September 2011

AbstractNitration of 1‐methoxy naphthalene with ceric ammonium nitrate affords the unusual dimeric nitration product (I) along with 5 known nitrated compounds.
ChemInform Abstract: Axially Chiral Phosphine—Oxazoline Ligands in Silver(I)‐Catalyzed Asymmetric Mannich Reaction of N‐Boc Aldimines with Trimethylsiloxyfuran.
Authors: Zhao Qian‐Yi , Shi Min 
Published: September 2011

AbstractAmong 12 chiral binaphthylphosphines, (Ra)‐BOP is the best ligand in the reaction with imine (IIb).
ChemInform Abstract: A Highly Efficient Access to Spiroketals, Mono‐Unsaturated Spiroketals, and Furans: Hg(II)‐Catalyzed Cyclization of Alkyne Diols and Triols.
Authors: Ravindar Kontham , Reddy Maddi Sridhar , Deslongchamps Pierre 
Published: September 2011

AbstractThe reaction leads to spirocyclic products with excellent regioselectivity.
ChemInform Abstract: A Base‐Modulated Chemoselective Synthesis of 3‐Cyanoindoles or 4‐Cyanoquinolines Using a Palladium‐Catalyzed N‐Heterocyclization.
Authors: Banini Serge R. , Turner Michael R. , Cummings Matthew M. , Soederberg Bjoern C. G. 
Published: September 2011

AbstractDepending on the absence or presence of DBU, cyanoalkenes (I) cyclize either to indole or quinoline derivatives (II) or (III).
ChemInform Abstract: Synthesis and Antimicrobial Activity of Some New 4‐Hetarylpyrazole and Furo[2,3‐c]pyrazole Derivatives.
Authors: Bondock Samir , Khalifa Wesam , Fadda Ahmed A. 
Published: September 2011

AbstractA variety of new functionalized 4‐hetarylpyrazole and furopyrazole derivatives are synthesized via reaction of 5‐hydroxypyrazole (I) with appropriate nucleophiles.
ChemInform Abstract: Synthesis of α,α‐Diarylacetamides from Benzyl Aryl Ketones Using 2‐Azido‐1,3‐dimethylimidazolinium Hexafluorophosphate.
Authors: Kitamura Mitsuru , Miyagawa Satoshi , Okauchi Tatsuo 
Published: September 2011

AbstractKetones (I) react with title compound (II) to give migratory amidated compounds (III), which are transformed into the corresponding acetamides (IV) by treatment with LiAlH4.
ChemInform Abstract: Synthesis of Substituted Benzoxazolinones by the Curtis Rearrangement: Crystal Structures of Intermediates and By‐Products.
Authors: Laus Gerhard , Kahlenberg Volker , Wurst Klaus , Nerdinger Sven , Schottenberger Herwig 
Published: September 2011

AbstractThe synthesis of 7‐substituted benzoxazolinones (IV) by the Curtis rearrangement of (III) is presented.
ChemInform Abstract: Novel Synthesis and Cytotoxic Activity of Some Chromeno[3,4‐b]pyrrol‐4(3H)‐ones.
Authors: Soman S. S. , Thaker T. H. , Rajput R. A. 
Published: September 2011

AbstractA new synthesis of title chromenopyrrolones (IV) based on the condensation of aminochromenones (I) with α‐halo ketones (II) is given.
ChemInform Abstract: Silver‐Catalyzed Cycloisomerization of 1,n‐Allenynamides.
Authors: Garcia Pierre , Harrak Youssef , Diab Lisa , Cordier Pierre , Ollivier Cyril , Gandon Vincent , Malacria Max , Fensterbank Louis , Aubert Corinne 
Published: September 2011

AbstractDepending on the substitution pattern of the allene moiety, various N‐heterocycles which incorporate cross‐conjugated trienes are synthesized.