bluuebunny/crossref_metadata_2025_split huggingface dataset:
Process improvement for fermentation coupling with foam separation: a convenient strategy for cell recycle
Authors: Zhang Da , Dong Kai , Xu Dandan , Zheng Huijie , Wu Zhaoliang , Xu Xin 
Published: April 2015

AbstractApplications of fermentation coupling with foam separation technology show great advantages in many natural biosurfactants fermentation such as nisin, surfactin, and polymyxin E. However, only a few reports focus on process improvement, i.e. cells overflowing with foam. Because the cells also have hydrophobicity, it will overflow during foam separation, which decrease the productivity and contaminate the environment. Therefore, it is important to prevent cell from overflowing. In this study, a new approach was proposed to increase yield, using fermentation coupling with foam separation technology. Meanwhile, we tried to prevent cell from overflowing. This strategy was characterized by enrichment, recovery percentage, and inactivity percentage for product and cells. The results indicated pH was the most important factor in foam separation of polymyxin E. The optimal condition for fermentation coupling with foam separation was determined. The maximum total titer of polymyxin E reached 917 932.31 U (1147.4 U/mL) using coupling strategy that was 1.36 times more than total titer in shaken‐flask culture. Additionally, the adsorption mechanism for polymyxin E and cells was studied. The results indicated polymyxin E were mainly adsorbed on bubble, while the cells were partly in liquid form and partly adsorbed on undesired protein. Undesired protein can be considered as a stabilizer in foam separation of polymyxin E. Copyright © 2015 Curtin University of Technology and John Wiley & Sons, Ltd.
Kinetics and crystallization in pH‐sensitive free‐radical crosslinking polymerization of acrylic acid
Authors: Kim Byungsoo , Hong Daesun , Chang Wenji V. 
Published: April 2015

ABSTRACTFree‐radical crosslinking polymerization and crystallization of acrylic acid (AAc) were investigated by shear storage modulus (G′) measurements in pH 2, as well as in pH 6 and pH 10, by varying the molar ratio of crosslinking agent (N,N′‐methylene bis‐acrylamide; MBAAm) to AAc (0.583 × 10−3, 1.169 × 10−3, 1.753 × 10−3, and 2.338 × 10−3). Our results showed that the pre‐gelation time was the same at pH 2, regardless of the concentration of MBAAm. The propagation time was determined by the initial feed concentration of AAc, and the length of the linear curve in the propagation was proportional to the concentration of MBAAm. The Avrami exponent (n), as an indicative of growing pattern of an infinite molecule, in the crystallization was increased in proportional to the concentration of MBAAm, and generally low at pH 2. In the deceleration phase, n was observed near 1.0 throughout the all specimens. These results indicated that (1) the length of the pre‐gelation period was determined by the ionization of AAc (or pH), (2) the polymerization rate of AAc was not affected by the concentration of MBAAm, and (3) the inhomogeneity of hydrogel was determined by the growing pattern of infinite molecule in propagation phase. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42195.
Biosynthesis of Sesterterpenes, Head‐to‐Tail Triterpenes, and Sesquarterpenes in Bacillus clausii: Identification of Multifunctional Enzymes and Analysis of Isoprenoid Metabolites
Authors: Ueda Daijiro , Yamaga Hiroaki , Murakami Mizuki , Totsuka Yusuke , Shinada Tetsuro , Sato Tsutomu 
Published: April 2015

AbstractWe performed functional analysis of recombinant enzymes and analysis of isoprenoid metabolites in Bacillus clausii to gain insights into the biosynthesis of rare terpenoid groups of sesterterpenes, head‐to‐tail triterpenes, and sesquarterpenes. We have identified an (all‐E)‐isoprenyl diphosphate synthase (E‐IDS) homologue as a trifunctional geranylfarnesyl diphosphate (GFPP)/hexaprenyl diphosphate (HexPP)/heptaprenyl diphosphate (HepPP) synthase. In addition, we have redefined the function of a tetraprenyl‐β‐curcumene synthase homologue as that of a trifunctional sesterterpene/triterpene/sesquarterpene synthase. This study has revealed that GFPP, HexPP, and HepPP, intermediates of two isoprenoid pathways (acyclic terpenes and menaquinones), are biosynthesized by one trifunctional E‐IDS. In addition, GFPP/HexPP and HepPP are the primary substrates for the biosynthesis of acyclic terpenes and menaquinone‐7, respectively.
Postsynthetic Metal and Ligand Exchange in MFU‐4l: A Screening Approach toward Functional Metal–Organic Frameworks Comprising Single‐Site Active Centers
Authors: Denysenko Dmytro , Jelic Jelena , Reuter Karsten , Volkmer Dirk 
Published: April 2015

AbstractThe isomorphous partial substitution of Zn2+ ions in the secondary building unit (SBU) of MFU‐4l leads to frameworks with the general formula [MxZn(5–x)Cl4(BTDD)3], in which x≈2, M=MnII, FeII, CoII, NiII, or CuII, and BTDD=bis(1,2,3‐triazolato‐[4,5‐b],[4′,5′‐i])dibenzo‐[1,4]‐dioxin. Subsequent exchange of chloride ligands by nitrite, nitrate, triflate, azide, isocyanate, formate, acetate, or fluoride leads to a variety of MFU‐4l derivatives, which have been characterized by using XRPD, EDX, IR, UV/Vis‐NIR, TGA, and gas sorption measurements. Several MFU‐4l derivatives show high catalytic activity in a liquid‐phase oxidation of ethylbenzene to acetophenone with air under mild conditions, among which Co‐ and Cu derivatives with chloride side‐ligands are the most active catalysts. Upon thermal treatment, several side‐ligands can be transformed selectively into reactive intermediates without destroying the framework. Thus, at 300 °C, CoII‐azide units in the SBU of Co‐MFU‐4l are converted into CoII‐isocyanate under continuous CO gas flow, involving the formation of a nitrene intermediate. The reaction of CuII‐fluoride units with H2 at 240 °C leads to CuI and proceeds through the heterolytic cleavage of the H2 molecule.
Non‐Invasive Salivary Electrochemical Quantification of Paraquat Poisoning Using Boron Doped Diamond Electrode
Authors: Selva Thiago Matheus Guimarães , Reis de Araujo William , Cesar da Paixão Thiago Regis Longo 
Published: April 2015

AbstractThe present work describes the first electrochemical method for quantifying paraquat herbicide poisoning in human saliva samples. Paraquat shows two couples of well‐defined peaks in aqueous solution using a boron doped diamond (BDD) electrode. By using square wave voltammetry (SWV) technique under optimum experimental conditions, a linear analytical curve was obtained for paraquat concentrations ranging from 0.800 to 167 µmol L−1, with a detection limit of 70 nmol L−1. This method was applied to quantify paraquat spikes in human saliva samples and in two different water samples (tap and river). The recovery values obtained ranged from 83.0 to 104 % and 99.1 to 105 %, respectively, which highlight the accuracy of the proposed method.
Polyion‐Sensitive Polymeric Membrane‐Based Pulstrode as a Potentiometric Detector in Liquid Chromatography
Authors: Wang Xuewei , Balijepalli Anant S. , Meyerhoff Mark E. 
Published: April 2015

AbstractPotentiometric polyion‐sensitive polymeric membrane electrodes are capable of detecting a wide variety of polyionic macromolecules. Herein, we utilize this lack of selectivity to report the first application of this sensor technology as a detector in liquid chromatography (LC). A reversible polycation pulstrode based on tridodecylmethylammonium‐dinonylnaphthalene sulfonate doped within a polymeric membrane is employed as the LC detector. Poly‐arginines/protamine mixtures are separated by cation‐exchange/affinity chromatography on an immobilized heparin column, with eluted polycation peptide bands clearly observed via the pulstrode detector. The LC‐pulstrode system is further applied to follow the production of different polycation peptides derived from thermolysin catalyzed protamine digestion.
Polyketides and Meroterpenoids from Neosartorya glabra
Authors: Liu Wen‐Hong , Zhao Hong , Li Rong‐Qun , Zheng Hong‐Bin , Yu Qin 
Published: April 2015

AbstractTwo new polyketides, neosarphenols A and B (1 and 2, resp.), were isolated from Neosartorya glabra, together with six known polyketides, 3–8, and two meroterpenoids, 9 and 10. The structures of the new compounds were elucidated by comprehensive spectroscopic analysis, especially by HR‐ESI‐MS and NMR experiments. All compounds were evaluated for their cytotoxic activities against MDA‐MB‐231, MCF‐7, and PANC‐1 tumor cell lines; 1 and 6 exhibited selective and moderate cytotoxicities against PANC‐1 cell line.
Selenophen‐2‐yl‐Substituted Thiocarbonyl Ylides – at the Borderline of Dipolar and Biradical Reactivity
Authors: Mlostoń Grzegorz , Urbaniak Katarzyna , Linden Anthony , Heimgartner Heinz 
Published: April 2015

AbstractThe reactions of aryl (selenophen‐2‐yl) thioketones with CH2N2 occur with spontaneous elimination of N2, even at low temperature (−65°), to give regioselectively sterically crowded 4,4,5,5‐tetrasubstituted 1,3‐dithiolanes and/or a novel type of twelve‐membered dithia‐diselena heterocycles as dimers of the transient thiocarbonyl S‐methanides. The ratio of these products depends on the type of substituent located at C(4) of the phenyl ring. Whereas the formation of the 1,3‐dithiolanes corresponds to a [3+2] cycloaddition of an intermediate thiocarbonyl ylide with the starting thioketone, the twelve‐memberd ring has to be formed via dimerization of the ‘thiocarbonyl ylide’ with an extended biradical structure.
Studies on the Reactions of Thiocarbonyl S‐Methanides with Hetaryl Thioketones
Authors: Mlostoń Grzegorz , Pipiak Paulina , Linden Anthony , Heimgartner Heinz 
Published: April 2015

AbstractDihetaryl thioketones react with thiocarbonyl ylides to give 1,3‐dithiolanes in high yields. No competitive side reactions of the thiocarbonyl ylides were observed, evidencing the ‘superdipolarophilic’ character of this less‐known group of thioketones. Depending on the type of substituents present in both the thiocarbonyl ylide and the thioketone, formal [3+2] cycloadditions occur with complete regioselectivity or with formation of a mixture of both regioisomers. Regioselective formation of the sterically more crowded 1,3‐dithiolanes is explained via a mechanism involving stabilized 1,5‐biradicals. In systems with less‐efficient radical stabilization, e.g., in the case of adamantanethione S‐methanide, substantial violation of the regioselectivity was observed as a result of steric hindrance.
A Facile Synthesis of Face “D” Quinolino Annulated Benzazepinone Analogues with Its Quinoline Framework Appended To Oxadiazole, Triazole and Pyrazole Heterocycles
Authors: Kaur Navjeet , Anand Aditi , Kishore Dharma 
Published: April 2015

An exceedingly facile protocol to the hetero‐annulation of face “d” of benzazepinone with quinoline nucleus has been developed. The synthesis proceeded with the formation of the key intermediate 7‐fluoro‐benzazepin‐2,5‐dione (2), which resulted from the acylation of p‐fluoroaniline with succinyl chloride followed by treatment with PPA. Compound 2 underwent a very smooth Pfitzinger reaction with isatin to furnish the acid 3, the hydrazide of which reacted rapidly with reagents indicated in Schemes and to afford the corresponding oxadiazole, triazole, and pyrazole incorporated analogues 5, 6, 7, 8, 9, respectively, in acceptable yields.
Behavioral abnormalities are common and severe in patients with distal 22q11.2 microdeletions and microduplications
Authors: Lindgren Valerie , McRae Anne , Dineen Richard , Saulsberry Alexandria , Hoganson George , Schrift Michael 
Published: April 2015

AbstractWe describe six individuals with microdeletions and microduplications in the distal 22q11.2 region detected by microarray. Five of the abnormalities have breakpoints in the low‐copy repeats (LCR) in this region and one patient has an atypical rearrangement. Two of the six patients with abnormalities in the region between LCR22 D–E have hearing loss, which has previously been reported only once in association with these abnormalities. We especially note the behavioral/neuropsychiatric problems, including the severity and early onset, in patients with distal 22q11.2 rearrangements. Our patients add to the genotype–phenotype correlations which are still being generated for these chromosomal anomalies.
Impact of Preoperative ERCP on Laparoscopic Cholecystectomy: A Case‐Controlled Study with Propensity Score Matching
Authors: Ahn Keun Soo , Kim Yong Hoon , Kang Koo Jeong , Kim Tae‐Seok , Cho Kwang Bum , Kim Eun Soo 
Published: April 2015

AbstractBackgroundAlthough inflammation induced by endoscopic retrograde cholangiopancreatography (ERCP) may affect laparoscopic cholecystectomy (LC), making the procedure more difficult, clinical impact of ERCP on LC is unclear. The aim of this study was to evaluate the effects of ERCP on LC and to determine appropriate time of LC after ERCP.MethodsSix hundred twenty‐one patients who underwent LC for gallstone disease were enrolled. These patients were divided into two groups; patients with preoperative ERCP prior to LC (ERCP group) and patients who underwent LC without ERCP (non‐ERCP group). Among these patients, patients who had shown acute cholecystitis or cholangitis were excluded. To control for different demographic factors in the two groups, propensity score case matching was used at a 1:1 ratio. Finally, 142 patients were matched with 71 patients of the ERCP group and 71 patients of the non‐ERCP group. Intraoperative inflammation degree, technical difficulty, and postoperative outcome were analyzed.ResultsIn the ERCP group, the degree of inflammation was severe and operations were more difficult than those of the non‐ERCP group. The operation time was longer, and rates of open conversion were higher in the ERCP group. On multivariate analysis, preoperative ERCP was significant factor for difficult operations. The difficulty of operation was not different according to the operation timing after ERCP.ConclusionPreoperative ERCP is a significant factor in difficult LC. Therefore, experienced surgeons should perform LC after preoperative ERCP. Since operation difficulty was similar according to the timing of cholecystectomy after ERCP, there is no reason to delay LC after ERCP.
Emergence of californium as the second transitional element in the actinide series
Authors: Cary Samantha K. , Vasiliu Monica , Baumbach Ryan E. , Stritzinger Jared T. , Green Thomas D. , Diefenbach Kariem , Cross Justin N. , Knappenberger Kenneth L. , Liu Guokui , Silver Mark A. , DePrince A. Eugene , Polinski Matthew J. , Van Cleve Shelley M. , House Jane H. , Kikugawa Naoki , Gallagher Andrew , Arico Alexandra A. , Dixon David A. , Albrecht-Schmitt Thomas E. 
Published: April 2015

AbstractA break in periodicity occurs in the actinide series between plutonium and americium as the result of the localization of 5f electrons. The subsequent chemistry of later actinides is thought to closely parallel lanthanides in that bonding is expected to be ionic and complexation should not substantially alter the electronic structure of the metal ions. Here we demonstrate that ligation of californium(III) by a pyridine derivative results in significant deviations in the properties of the resultant complex with respect to that predicted for the free ion. We expand on this by characterizing the americium and curium analogues for comparison, and show that these pronounced effects result from a second transition in periodicity in the actinide series that occurs, in part, because of the stabilization of the divalent oxidation state. The metastability of californium(II) is responsible for many of the unusual properties of californium including the green photoluminescence.
Insights into perfluorooctane sulfonate photodegradation in a catalyst-free aqueous solution
Authors: Lyu Xian-Jin , Li Wen-Wei , Lam Paul K. S. , Yu Han-Qing 
Published: April 2015

AbstractPhotodegradation in the absence of externally added chemicals could be an attractive solution for the removal of perfluorooctane sulfonate (PFOS) in aqueous environment, but the low decomposition rate presents a severe challenge and the underlying mechanisms are unclear. In this study, we demonstrated that PFOS could be effectively degraded in a catalyst-free aqueous solution via a reduction route. Under appropriate pH and temperature conditions, a rapid PFOS photodegradation, with a pseudo-first-order decomposition rate constant of 0.91 h−1, was achieved. In addition, hydrated electrons were considered to be the major photo-generated reductive species responsible for PFOS photodegradation in this system. Its production and reduction ability could be significantly affected by the environmental conditions such as pH, temperature and presence of oxidative species. This study gives insights into the PFOS photodegradation process and may provide useful information for developing catalyst-free photodegradation systems for decomposing PFOS and other persistent water contaminants.
Spread spectrum high performance techniques for a long haul high frequency link
Authors: Alsina‐Pagès Rosa Maria , Salvador Martí , Hervás Marcos , Bergadà Pau , Pijoan Joan Lluís , Badia David 
Published: April 2015

Skywave ionospheric communication systems offer a good choice to satellite communications when transmitting from the poles. For the last 10 years the authors have been sounding and testing modulations through a 12 700 km high frequency link from the Spanish Antarctic Station to Spain. Previous tests comparing direct sequence spread spectrum (DS‐SS) and orthogonal frequency division multiplexing (OFDM) showed that spread spectrum bit rate error (BER) results outperformed OFDM at the expense of lower bit rates. In this study the authors present three spread spectrum techniques for this long haul link that increase the bit rate and the spectral efficiency of the direct sequence while keeping the good BER performance obtained. Tests have been performed with several symbol periods as well as different bandwidth for each technique, hence the authors can conclude which combination best suits this channel.
Economic evaluation of maintenance strategies for wind turbines: a stochastic analysis
Authors: Kerres Bertrand , Fischer Katharina , Madlener Reinhard 
Published: April 2015

The authors develop a stochastic model for assessing the life‐cycle cost and availability of wind turbines resulting from different maintenance scenarios, with the objective to identify the most cost‐effective maintenance strategy. Using field‐data‐based reliability models, the wind turbine – in terms of reliability – is modelled as a serial connection of the most critical components. Both direct cost for spare parts, labour and access to the turbine, as well as indirect cost from production losses are explicitly taken into account. The model is applied to the case of a Vestas V44–600 kW wind turbine. Results of a reliability‐centred maintenance analysis of this wind turbine are used to select the most critical wind turbine components and to identify possible maintenance scenarios. This study reveals that corrective maintenance is the most cost‐effective maintenance strategy for the gearbox and the generator of the V44 turbine, while the cost benefit of condition‐based maintenance using online condition‐monitoring systems increases with higher electricity price, turbine capacity and remoteness of sites.
Preparation and photocatalytic properties of a visible light responsive and magnetically separated photocatalyst of γ‐Fe2O3/SiO2/GSs/TiO2
Authors: Chen Deqiang , Chen Yiqun , Li Yang , Ye Shaonan 
Published: April 2015

A graphene sheet (GS) synthetised from natural graphite powder was doped in titanium dioxide (TiO2) through the sol–gel method to improve the photocatalytic activity and magnetic γ‐Fe2O3/SiO2 particles were added subsequently to improve recycling and reduce the waste of the catalyst. The morphology, microstructure, absorption spectrum and magnetic property of the γ‐Fe2O3/SiO2/GSs/TiO2 composites were characterised via X‐ray diffraction, transmission electron microscopy, diffuse‐reflectance spectra and a vibrating sample magnetometer, respectively. The result revealed that (i) the nanocrystalline structure of γ‐Fe2O3/SiO2/GSs/TiO2 composites is nearly unchanged compared with pure P25 nanoparticles; (ii) there was a redshift in the absorption edge of the photocatalyst composite; (iii) the photocatalyst composites displayed good superparamagnetism which was in favour of the reclamation of the catalyst; (iv) the adsorption and visible light photocatalytic activity of the composite is enhanced greatly on decomposition of methylene blue and (v) the photocatalysts maintained high photocatalytic activity after being reused several times.
Did a “perfect storm” of oceanic changes and continental anthropogenic impacts cause northern hemisphere anguillid recruitment reductions?
Authors: Miller Michael J. , Feunteun Eric , Tsukamoto Katsumi 
Published: April 2015

AbstractThe three northern hemisphere anguillid eel species experienced recruitment declines at similar times beginning in the 1970s and 1980s, but the exact causes of the declines have remained unclear. Attention focused on two categories of possible causes that included (i) anthropogenic impacts on eel growth habitats, such as dam construction, degradation and pollution of habitats, introduction of parasites, overfishing and (ii) changes in ocean-atmospheric conditions affecting their marine life-history stages. The cumulative effects of reaching peaks in dam construction, levels of pollution, and eutrophication just before the eel declines likely had reduced eel production in many areas, and contamination by metallic and organic compounds and parasites may have reduced reproductive success. Shifts in ocean-atmospheric conditions also occurred just before the eel declines that could have reduced feeding success of larvae or disrupted larval transport. If oceanic regime shifts reduced production of the marine snow food of eel larvae, it may have affected larval survival and recruitment success, especially if there is a critical time-window for successful larval first feeding when marine snow particles need to be abundant. A reduction of these particles could result in density-dependent early mortality of the larvae of each spawning event, and competition for marine snow particles with sympatrically spawning mesopelagic eel larvae would amplify this effect. Nutrient reductions causing shifts in the relative abundance of phytoplankton contributing to marine snow production and of ubiquitous cyanobacteria may mediate levels of larval survival in areas with high spawning activity. Reductions of eels reaching the spawning area from species range margins that spawn outside of peak spawning periods could have reduced recruitment further. It appears likely that a variety of impacts, oceanic and anthropogenic occurred simultaneously causing sudden declines of these eel populations.