bluuebunny/crossref_metadata_2025_split huggingface dataset:
Efficient liquid phase oxidation of olefins and aromatic alcohol catalyzed by reusable polymer anchored Schiff base complexes
Authors: Islam Manirul , Mondal Paramita , Mukherjee Sanghamitra , Mobarak Manir , Roy Anupam Sigha , Mondal Sanchita , Sarkar Saikat 
Published: November 2009

AbstractBACKGROUND: Heterogenization of homogeneous catalyst has become an interesting process for the catalytic oxidation of olefins and aromatic alcohol. This may provide a new kind of catalyst that is not only friendly to the environment but also exhibits higher thermal and chemical stabilities.RESULTS: Polymer anchored Schiff‐base complexes of iron(III), copper(II) and cobalt(II) have been synthesized and characterized. The catalytic potential of these complexes has been tested for the oxidation of cyclohexene. The effect of varying solvent, oxidant, substrate oxidant molar ratio, temperature and catalyst amount has been studied. Under optimized reaction conditions 91, 88 and 81% conversion of cyclohexene was obtained with Fe(III), Cu(II) and Co(II) catalysts, respectively. Moreover, the oxidation of other substrates, such as styrene, benzylalcohol, toluene and 1‐hexene were also efficiently carried out by these catalysts.CONCLUSION: The immobilized complexes showed excellent catalytic activity along with high selectivity for the oxidation of olefins and alcohols. The catalysts can be recycled more than five times without any noticeable loss of catalytic activity. Copyright © 2009 Society of Chemical Industry
Contrast expression patterns of JNK1 during sex reversal of the rice‐field eel
Authors: Xiao Ya‐Mei , Chen Lili , Liu Jiao , Liu Wen‐Bin , Chen He‐Ge , Zou Li‐Jun , Liu Yun , Li David Wan‐Cheng 
Published: November 2009

AbstractThe c‐Jun N‐terminal kinases (JNKs) are members of the mitogen‐activated protein kinase family. Their functions in regulating animal development have been well studied in both invertebrates and vertebrates. However, it remains to be determined whether they play a role in sex determination. Here we present first evidence to show that expression of JNK1 displays distinct patterns during sex reversal of rice‐field eel. Molecular cloning reveals that JNK1 is well conserved among rice‐field eel and other vertebrates. Both quantitative real‐time polymerase chain reaction and Western blot analysis demonstrate that JNK1 is highly expressed in the ovary of the female individual and reduced to a substantial degree at the later stage of the intersex. However, when the intersex individual develops into the stage of male, expression of the JNK1 in the testis of the male individual is distinctly downregulated. Associated with the contrast JNK1 expression pattern in female and male gonads, several stem cell marker genes including Nanog, Oct‐3/4, and Sox‐2 were also differentially expressed in female and male germinal stem cells. Together, these results suggest it is possible that JNK1 plays an important role in sexual reversal of the rice‐field eel.J. Exp. Zool. (Mol. Dev. Evol.) 314B:242–256, 2010. © 2009 Wiley‐Liss, Inc.
A poly(ethylene) glycolylated peptide for ocular delivery compacts DNA into nanoparticles for gene delivery to post‐mitotic tissues in vivo
Authors: Read Sarah Parker , Cashman Siobhan M. , Kumar‐Singh Rajendra 
Published: November 2009

AbstractBackgroundWe have previously shown that a novel synthetic peptide for ocular delivery (POD) can efficiently compact DNA and deliver it to cells in vitro. This observation prompted us to develop use of POD as a nonviral vector in vivo.MethodsPOD peptide was modified using poly(ethylene) glycol (PEG‐POD) and used to compact DNA into nanoparticles that were then analysed using electron microscopy, dynamic light scattering, and fluorescent labeling. Transfection efficiency and localization were determined 48 h post‐injection into the subretinal space of the mouse eye using luciferase and LacZ, respectively. Efficiency of ocular transfection was compared to two other PEGylated peptides: PEG‐TAT and PEG‐CK30.ResultsPEG‐POD can compact DNA and form discrete nanoparticles of approximately 136 nm that can penetrate and transduce the retinal pigment epithelium (RPE) in vivo. PEG‐POD significantly increased expression of plasmid DNA by 215‐fold, PEG‐TAT by 56.52‐fold, and PEG‐CK30 by 24.73‐fold relative to DNA injected alone. In all cases β‐galactosidase was observed primarily in the RPE layer after subretinal injection. Electrophysiological analyses of PEG‐POD transduced retina indicates an absence of PEG‐POD‐mediated toxicity. PEG‐POD can protect plasmid DNA from DNaseI digestion, resulting in significant transfection of the lung after intravenous injection in mice.ConclusionsPEG‐POD was found to significantly increase gene delivery relative to both DNA alone and other pegylated peptides. These findings highlight the use of pegylated peptides, and specifically PEG‐POD, as novel gene delivery vectors. Copyright © 2009 John Wiley & Sons, Ltd.
Biodistribution of gadolinium‐based contrast agents, including gadolinium deposition
Authors: Aime Silvio , Caravan Peter 
Published: November 2009

AbstractThe biodistribution of approved gadolinium (Gd)‐based contrast agents (GBCAs) is reviewed. After intravenous injection GBCAs distribute in the blood and the extracellular space and transiently through the excretory organs. Preclinical animal studies and the available clinical literature indicate that all these compounds are excreted intact. Elimination tends to be rapid and, for the most part, complete. In renally insufficient patients the plasma elimination half‐life increases substantially from hours to days depending on renal function. In patients with impaired renal function and nephrogenic systemic fibrosis (NSF), the agents gadodiamide, gadoversetamide, and gadopentetate dimeglumine have been shown to result in Gd deposition in the skin and internal organs. In these cases, it is likely that the Gd is no longer present as the GBCA, but this has still not been definitively shown. In preclinical models very small amounts of Gd are retained in the bone and liver, and the amount retained correlates with the kinetic and thermodynamic stability of the GBCA with respect to Gd release in vitro. The pattern of residual Gd deposition in NSF subjects may be different than that observed in preclinical rodent models. GBCAs are designed to be used via intravenous administration. Altering the route of administration and/or the formulation of the GBCA can dramatically alter the biodistribution of the GBCA and can increase the likelihood of Gd deposition. J. Magn. Reson. Imaging 2009;30:1259–1267. © 2009 Wiley‐Liss, Inc.
Retrospective assessment of prevalence of nephrogenic systemic fibrosis (NSF) after implementation of a new guideline for the use of gadobenate dimeglumine as a sole contrast agent for magnetic resonance examination in renally impaired patients
Authors: Abujudeh Hani H. , Rolls Hillary , Kaewlai Rathachai , Agarwal Sheela , Gebreananya Zelalem A. , Saini Sanjay , Schaefer Pamela W. , Kay Jonathan 
Published: November 2009

AbstractFrom May 2007 to January 2008, patients with Stage 3‐5 chronic kidney disease (CKD) undergoing gadobenate dimeglumine (GBD)‐enhanced magnetic resonance (MR) examinations were included in the retrospective investigation. The electronic medical records were reviewed to assess the prevalence of nephrogenic systemic fibrosis (NSF) in renally impaired patients underwent GBD‐enhanced MR examinations. In all, 250 patients (98 men, mean age 72.6 years) were included: 97% of the patients had Stage 3 CKD (estimated GFR 30–59 mL/min/1.73 m2); 37% had been exclusively exposed to GBD. The remaining were exposed to GBD and other gadolinium‐based contrast agents (GBCAs). The mean dose of GBD was 22 mL (standard deviation [SD], 11.2). Including exposure to other GBCAs, the mean cumulative dose of gadolinium was 61 mL (SD, 62.3). A total of 206 patients (82%) had skin examinations following the last GBD administration (mean duration, 108 days). No evidence of suspected or diagnosed NSF was found. In conclusion, on the basis of a retrospective chart review there was no skin evidence of NSF in predominantly Stage 3 CKD patients who were exposed to GBD at an average follow‐up of 108 days, either solely or in combination with other GBCAs. J. Magn. Reson. Imaging 2009;30:1335–1340. © 2009 Wiley‐Liss, Inc.
Gadolinium‐based contrast agents and nephrogenic systemic fibrosis: Why did it happen and what have we learned?
Authors: Weinreb Jeffrey C. , Abu‐Alfa Ali K. 
Published: November 2009

AbstractThis article addresses two questions about gadolinium‐based contrast agents (GBCAs) and nephrogenic systemic fibrosis (NSF): “Why did it happen” and “What have we learned”? It reviews the events leading to the discovery of an association between NSF and GBCAs. Various factors are elucidated that contributed to the delay between the time when GBCA came into widespread clinical use and a link was made with NSF, including use in renal‐compromised patients, high‐dose magnetic resonance angiography (MRA), lack of documentation and adequate databases, policy and regulatory changes, and an absence of scientific evidence. The authors conclude that the overriding cause was lack of awareness. J. Magn. Reson. Imaging 2009;30:1236–1239. © 2009 Wiley‐Liss, Inc.
High‐throughput method for on‐target performic acid oxidation of MALDI‐deposited samples
Authors: Williams Brad J. , Russell William K. , Russell David H. 
Published: November 2009

AbstractAn information‐rich on‐target performic acid oxidation method, which is compatible with alkylation for differentiation of free cysteine versus disulfide‐containing peptides, is described. On‐target oxidation is achieved using performic acid vapor to oxidize disulfide‐containing peptides and/or small proteins on the matrix‐assisted laser desorption/ionization (MALDI) sample deposits. The on‐target oxidation method is preferred over solution‐phase oxidation methods because (1) less sample handing is required, (2) oxidation throughput is drastically increased and (3) ion suppression effects are reduced because performic acid is not added directly to the MALDI spot. The utility of this method is demonstrated by simultaneous oxidation of multiple MALDI sample deposits containing model disulfide‐linked peptides, intact bovine insulin and a bovine ribonuclease A proteolytic digest. Copyright © 2009 John Wiley & Sons, Ltd.
Acute hyperosmotic stimulus‐induced Fos expression in neurons depends on activation of astrocytes in the supraoptic nucleus of rats
Authors: Yuan Hua , Gao Bei , Duan Li , Jiang Shan , Cao Rong , Xiong Ying‐Fei , Rao Zhi‐Ren 
Published: November 2009

AbstractAcute hyperosmolarity induced a time‐dependent expression of Fos protein in both neurons and astrocytes of the rat supraoptic nucleus, with peak Fos expresion occurring at 45 min in astrocytes and at 90 min in neurons after hypertonic stimulation in vivo. To determine whether the two cell types were activated separately or in an integrated manner, animals were pretreated with fluorocitrate, a glial metabolic blocker or carbenoxolone, a gap junction blocker followed by an acute hypertonic stimulation similar to that of the controls. Antibodies against glial fibrillary acidic protein, connexin 43, vasopressin, and oxytocin were used in serial sections to identify the cellular elements of the supraoptic nucleus. It was found that interruption of astrocyte metabolism with fluorocitrate significantly reduced Fos protein expression in both astrocytes and neurons, whereas blockage of gap junctions with carbenoxolone clearly reduced Fos protein expression in neurons, but not in astrocytes. These results indicate that both neurons and astrocytes in the rat supraoptic nucleus are involved in regulating osmolarity. Astrocytes are activated first, whereas connexin 43 functional hemichannels in SON astrocytes are required for the subsequent activation of the neurons. © 2009 Wiley‐Liss, Inc.
Periodicities in Indian monsoon rainfall over spectrally homogeneous regions
Authors: Azad Sarita , Vignesh T. S. , Narasimha R. 
Published: November 2009

AbstractThis work presents results of a sharper search for significant periodicities in Indian monsoon rainfall, based on the recognition of the area's meteorological heterogeneity. Towards this end, a quantitative definition of spectral homogeneity is proposed, and the concept is used to classify India into distinct spectrally homogeneous regions (SHR) by two independent methods. The analysis is then carried out for each of the 10 SHRs, which may cut across or be subsets of homogeneous‐rainfall zones defined earlier by various workers based on different criteria. A particularly interesting region is SHR7, the largest spectrally homogeneous cluster identified by both methods, which includes sub‐divisions from west central and peninsular India. The spectrum here shows a significant dip in the frequency band 0.2–0.31 per year, flanked on either side by a rich structure characterised by nearly coincident spectral peaks in all the seven sub‐divisions constituting the region. The significant peaks (confidence level ≥ 99%) in SHR7 are 3.0, 5.7, 10.9, 13.3, 24.0, 30.3 and 60.6 years. The spectral dip is conjectured to be associated with the ENSO (EI Niño‐Southern Oscillation) phenomenon, which occurs on the period scales of 3–5 years and is known to be anti‐correlated with monsoon rainfall. Copyright © 2009 Royal Meteorological Society
Nitrate modifies the assimilation pattern of ammonium and urea in wheat seedlings
Authors: Garnica Maria , Houdusse Fabrice , Zamarreño Angel M , Garcia‐Mina Jose M 
Published: November 2009

AbstractBACKGROUND: In certain plant species, ammonium or urea nutrition can cause negative effects on plant development which can result in toxic symptoms. Some authors suggest that the presence of nitrate can alleviate these symptoms by increasing ammonium and urea assimilation, avoiding its accumulation. In order to study this hypothesis, wheat (Triticum aestivum L.) seedlings were grown with various nitrogen supplies containing the main nitrogen forms (ammonium, nitrate and urea). Amino acids content and the activity of the three main enzymes involved in nitrogen assimilation (nitrate reductase, glutamine synthetase and urease) were studied.RESULTS: The application of nitrate along with urea and/or ammonium was not associated with a time‐sustained increase in the activity of glutamine synthetase and urease. Amino acid analysis revealed that nitrate induced changes in amino acid metabolism enhancing its concentration. Likewise the content of protein was also higher in nitrate‐treated plants.CONCLUSION: These results suggest that the effect of nitrate is compatible with a rapid and transient increase in the activity of glutamine synthetase and urease during the first hour after the onset of treatments. Nevertheless, a possible effect of nitrate reducing ammonium accumulation through the activation of alternative metabolic pathways different from that involving glutamine synthetase cannot be ruled out. Finally, nitrate effects on amino acid concentration indicate that, whereas ammonium assimilation takes place principally in the root, urea and nitrate assimilation occurred in the shoot, under the conditions of the experiment. Copyright © 2009 Society of Chemical Industry
Aqueous extract of Hibiscus sabdariffa L. decelerates acetaminophen‐induced acute liver damage by reducing cell death and oxidative stress in mouse experimental models
Authors: Liu Liang‐Chih , Wang Chau‐Jong , Lee Ching‐Chih , Su Sheng‐Chi , Chen Huei‐Lin , Hsu Jen‐Dong , Lee Huei‐Jane 
Published: November 2009

AbstractBACKGROUND: Acetaminophen (AAP)‐induced oxidative stress can cause cell death to induce liver damage. The antioxidant effect of Hibiscus sabdariffa L. (HS) was shown in previous studies. In this study the effect of HS extract (HSE) on AAP‐induced liver injury in BALB/c mice was investigated.RESULTS: In vivo, BALB/c mice were fed orally with 200, 400 or 600 mg kg−1 HSE for 2 weeks and then injected with 1000 mg kg−1 AAP. Pretreatment with HSE decreased lipid peroxidation and increased catalase activity and glutathione level. It also decreased AAP‐induced liver injury, accompanied by decreased expression of pJNK, Bax and tBid in the liver. Additionally, HSE protected BALB/c normal liver cells from AAP‐induced damage in vitro.CONCLUSION: It has been demonstrated that HSE can protect the mouse liver from AAP‐induced injury and that the protective mechanism might involve decreasing oxidative stress and reducing cell death. Copyright © 2009 Society of Chemical Industry
Direct purification of tanshinones from Salvia miltiorrhiza Bunge by high‐speed counter‐current chromatography without presaturation of the two‐phase solvent mixture
Authors: Wu Dingfang , Jiang Xinhang , Wu Shihua 
Published: November 2009

AbstractTanshen, the rhizome of Salvia miltiorrhiza Bunge, is a famous Traditional Chinese Medicine for multiple therapeutic remedies. This work presents the isolation and purification of tanshinone I and tanshinone IIA from the extract of the rhizome of S. miltiorrhiza by using high‐speed counter‐current chromatography (CCC) without presaturation of the two‐phase solvent mixture. The CCC method combines the results of CCC solvent system selection and components analyses of solvent mixture by GC, and thus it is possible to add accurately each individual solvent to prepare single saturated solvent phase without presaturation. The optimum CCC solvent system is a system of hexane–ethyl acetate–ethanol–water (8:2:7:3, v/v), which has been determined by usual solvent system selection and CCC runs. As a result, over 98% pure tanshinone IIA and over 94% pure tanshinone I have been obtained by using less solvent volume. Their structures have been identified by ESI‐MS, NMR spectra.
Application of MEKC to the monitoring of atrazine sorption behaviour on soils
Authors: Lima Diana L. D. , Erny Guillaume L. , Esteves Valdemar I. 
Published: November 2009

AbstractMeasuring interactions between soils and xenobiotics is critical to assess the threat to water resources posed by potentially harmful chemicals. Such studies are done via batch experiments where the chemical of interest is incubated with the soil for a long period of time. However, the analysis of the remaining concentration in the aqueous phase is often troublesome, due to dissolved organic matter that can interfere with the analysis. Thus, for such application a lengthy sample clean‐up is often needed prior to analysis. The aim of this work was to develop an alternative approach to monitor atrazine using MEKC. A buffer of 10 mM NaH2PO4 and 50 mM SDS was used to separate atrazine and soil organic matter in less than 7 min. Samples were injected without any pre‐treatment leading to a significantly lower total analysis time (sample clean‐up, column conditioning, separation) than HPLC. After full optimisation, good repeatability of retention time (RSD<1%) and peak areas (RSD<3%) was achieved as well as a good linearity (r2=0.9994) and relatively low LOD (0.26 mg/L). The method was applied to study the sorption of atrazine to a soil sample using batch equilibrium technique.
Liquid Crystal Alignment Properties of Poly‐(3‐thiopheneacetate)/Dialkyldimethylammonium Complexes
Authors: Yoon Young‐Sik , Kang Hyo , Kim Byoung Gak , Lee Jong‐Chan 
Published: November 2009

AbstractLiquid crystal alignment properties were investigated in liquid crystal (LC) cells fabricated with poly(3‐thiopheneacetate)/dialkyldimethylammonium (PTA‐Cn) complexes, where n is the number of carbon atoms in the alkyl groups in dialkyldimethylammonium bromide. Homeotropic LC alignment was observed in PTA‐Cn LC cells containing long alkyl groups (n = 14, 16, 18) with high pretilt angles close to 90°. Homeotropic LC alignment was observed from prepared LC cell made from PTA‐C12 film, while the homeotropic LC alignment was gradually changed to random alignment within 10 min. LC cells fabricated from PTA‐C10 always showed random alignment behavior. The surface orientational order parameters of the alkyl groups of PTA‐Cn films were estimated by near edge X‐ray absorption fine structure (NEXAFS) spectroscopy, producing values of 0.040, 0.111, 0.153, 0.151, and 0.170 for PTA‐C10, PTA‐12, PTA‐14, PTA‐16, and PTA‐18, respectively. Therefore, homeotropic LC alignment behavior correlated well with the order of alkyl groups on the complex surface.magnified image
Amphiphilic Hyperbranched Polymers Containing Two Types of β‐Cyclodextrin Segments: Synthesis and Properties
Authors: Tian Wei , Fan Xiao‐Dong , Kong Jie , Liu Yu‐Yang , Zhang Wei‐Hong , Cheng Guang‐Wen , Jiang Min 
Published: November 2009

AbstractAmphiphilic hyperbranched polymers carrying two types of β‐cyclodextrin groups including ionic and covalent bonding were synthesized via atom transfer radical polymerization and immobilization reaction. Their inclusion capabilities for single or double‐guest molecules were investigated by UV‐visible spectroscopy. Using Chlorambucil and Lonidamine as the double model drugs, their encapsulation efficiencies indicate that these polymers possess the capabilities of high drug‐loading. Furthermore, the release behaviors of these polymers were studied via UV‐visible spectroscopy. The results indicate that they can slow the release rate of double model drugs. Varying the pH values of environment or regulating their shell layer structures can control the release behaviors of double model drugs.magnified image
Construction and Properties of Hydrophobic Association Hydrogels with High Mechanical Strength and Reforming Capability
Authors: Jiang Guoqing , Liu Chang , Liu Xiaoli , Zhang Guohui , Yang Meng , Liu Fengqi 
Published: November 2009

AbstractHydrophobic association hydrogels (HA‐gels) with almost ideal properties were successfully prepared by micellar copolymerization, and the associated micelles acted as physical cross‐linking points in the network of HA‐gels. HA‐gels exhibit exceptional mechanical properties and transparency. However, the most striking properties are that HA‐gels possess the capability of self‐healing and remolding, which is mainly due to the dissociation and re‐association process of the associated micelles. Dried‐gels, which were prepared by stretching HA‐gels to a certain elongation for a period of time in the air, can be used as shrinkable or thermal sensitivity materials. HA‐gels have a broad selectivity for components, so we have synthesized HA‐gels with variously available properties by changing a corresponding component: thermoresponsive HA‐gels, nanosphere‐composite HA‐gels, and fluorescent HA‐gels. Therefore, we are sure that HA‐gels will be widely used in various fields, such as biology, medication, sensors, optics, and oil exploitation.magnified image
Droplet Microfluidics for Fabrication of Non‐Spherical Particles
Authors: Shum Ho Cheung , Abate Adam R. , Lee Daeyeon , Studart André R. , Wang Baoguo , Chen Chia‐Hung , Thiele Julian , Shah Rhutesh K. , Krummel Amber , Weitz David A. 
Published: November 2009

AbstractWe describe new developments for controlled fabrication of monodisperse non‐spherical particles using droplet microfluidics. The high degree of control afforded by microfluidic technologies enables generation of single and multiple emulsion droplets. We show that these droplets can be transformed to non‐spherical particles through further simple, spontaneous processing steps, including arrested coalescence, asymmetric polymer solidification, polymerization in microfluidic flow, and evaporation‐driven clustering. These versatile and scalable microfluidic approaches can be used for producing large quantities of non‐spherical particles that are monodisperse in both size and shape; these have great potential for commercial applications.magnified image