bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dipeptide‐Based Low‐Molecular‐Weight Efficient Organogelators and Their Application in Water Purification
Authors: Debnath Sisir , Shome Anshupriya , Dutta Sounak , Das Prasanta Kumar 
Published: July 2008

AbstractThe development of new low‐molecular‐weight gelators for organic solvents is motivated by several potential applications of gels as advanced functional materials. In the present study, we developed simple dipeptide‐based organogelators with a minimum gelation concentration (MGC) of 6–0.15 %, w/v in aromatic solvents. The organogelators were synthesized using different L‐amino acids with nonpolar aliphatic/aromatic residues and by varying alkyl‐chain length (C‐12 to C‐16). The self‐aggregation behavior of these thermoreversible organogels was investigated through several spectroscopic and microscopic techniques. A balanced participation of the hydrogen bonding and van der Waals interactions is crucial for efficient organogelation, which can be largely modulated by the structural modification at the hydrogen‐bonding unit as well as by varying the alkyl‐chain length in both sides of the hydrophilic residue. Interestingly, these organogelators could selectively gelate aromatic solvents from their mixtures with water. Furthermore, the xerogels prepared from the organogels showed a striking property of adsorbing dyes such as crystal violet, rhodamine 6G from water. This dye‐adsorption ability of gelators can be utilized in water purification by removing toxic dyes from wastewater.
Structure–Property Relationships for Self‐Assembled Zinc Chlorin Light‐Harvesting Dye Aggregates
Authors: Huber Valerie , Sengupta Sanchita , Würthner Frank 
Published: July 2008

AbstractA series of zinc 31‐hydroxymethyl chlorins 10 a–e and zinc 31‐hydroxyethyl chlorins 17 with varied structural features were synthesized by modifying naturally occurring chlorophyll a. Solvent‐, temperature‐, and concentration‐dependent UV/Vis and CD spectroscopic methods as well as microscopic investigations were performed to explore the importance of particular functional groups and steric effects on the self‐assembly behavior of these zinc chlorins. Semisynthetic zinc chlorins 10 a–e possess the three functional units relevant for self‐assembly found in their natural bacteriochlorophyll (BChl) counterparts, namely, the 31‐OH group, a central metal ion, and the 131 CO moiety along the Qy axis, and they contain various 172‐substituents. Depending on whether the zinc chlorins have 172‐hydrophobic or hydrophilic side chains, they self‐assemble in nonpolar organic solvents or in aqueous media, respectively. Zinc chlorins possessing at least two long side chains provide soluble self‐aggregates that are stable in solution for a prolonged time, thus facilitating elucidation of their properties by optical spectroscopy. The morphology of the zinc chlorin aggregates was elucidated by atomic force microscopy (AFM) studies, revealing well‐defined nanoscale rod structures for zinc chlorin 10 b with a height of about 6 nm. It is worth noting that this size is in good accordance with a tubular arrangement of the dyes similar to that observed in their natural BChl counterparts in the light‐harvesting chlorosomes of green bacteria. Furthermore, for the epimeric 31‐hydroxyethyl zinc chlorins 17 with hydrophobic side chains, the influence of the chirality center at the 31‐position on the aggregation behavior was studied in detail by UV/Vis and CD spectroscopy. Unlike zinc chlorins 10, the 31‐hydroxyethyl zinc chlorins 17 formed only small oligomers and not higher rod aggregate structures, which can be attributed to the steric effect imposed by the additional methyl group at the 31‐position.
Organocatalytic Three‐Component Reactions of Pyruvate, Aldehyde and Aniline by Hydrogen‐Bonding Catalysts
Authors: Li Xin , Deng Hui , Luo Sanzhong , Cheng Jin‐Pei 
Published: July 2008

AbstractHydrogen‐bonding catalysts have been found to catalyze one‐pot three‐component reactions of pyruvate, anilines and aldehydes to afford versatile 3‐amino‐1,5‐dihydro‐2H‐pyrrol‐2‐ones in high yields. Both, thioureas and phosphoric acids are viable catalysts for these reactions and have comparable activity. The corresponding chiral thioureas and phosphoric acids have also been used in these three‐component reactions to give pyrrol‐2‐ones in high yields and with moderate enantioselectivities.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Efficient Electrocatalytic Detection of Epinephrine at Gold Electrodes Modified with Self‐Assembled Metallo‐Octacarboxyphthalocyanine Complexes
Authors: Agboola Bolade O. , Ozoemena Kenneth I. 
Published: July 2008

AbstractElectrocatalysis of epinephrine at gold electrode pre‐modified with the self‐assembled monolayer of cysteamine and subsequently integrated with novel metallo‐octacarboxyphthalocyanine (MOCPc where M=Fe, Co and Mn) complexes (Au‐Cys‐MOCPc) was investigated. The electrodes showed response to the presence of epinephrine. The oxidation peak potential (Ep/V vs. Ag|AgCl, sat'd KCl) and charge transfer resistance (Rct (kΩ)) in epinephrine solution depend markedly on the central metal of the phthalocyanine cores: Au‐Cys‐FeOCPc<Au‐Cys‐MnOCPc<Au‐Cys‐CoOCPc. All the electrodes showed first order electrode kinetics in [epinephrine]; the Au‐Cys‐FeOCPc electrode exhibited catalytic rate constant (kch=4.1×107 M−1 s−1) which is higher than that of the Au‐cys‐CoOCPc or Au‐cys‐MnOCPc electrode. Mechanism, recognizing the mediation of the electrocatalytic process by the central M(II)/M(III) redox processes was proposed. Epinephrine electro‐oxidation at the Au‐cys‐FeOCPc electrode was studied in more details for the response characteristics. The diffusion coefficient of epinephrine was evaluated as (2.62±0.23)×10−9 cm2 s−1. It was established that Au‐Cys‐FeOCPc is suitable for sensitive determination of epinephrine in physiological pH (7.40) conditions showing linear concentration range of up to 300 nM, with excellent sensitivity (0.53±0.01 nA nM−1), and very low limits of detection (13.8 nM) and quantification (45.8 nM). The peak separation between ascorbic acid and epinephrine is large enough (190 mV) to permit simultaneous determination of both epinephrine and ascorbic acid in physiological pH 7.4 conditions using the Au‐cys‐FeOCPc electrode. Au‐cys‐FeOCPc electrode was successfully used for the determination of epinephrine in epinephrine hydrochloric acid injection with recovery of ca. 98.4%.
Synovial sarcoma of the head and neck: Rare case of cervical metastasis
Authors: Ishiki Hiroto , Miyajima Chie , Nakao Kazunari , Asakage Takahiro , Sugasawa Masashi , Motoi Toru 
Published: July 2008

AbstractBackground.Synovial sarcoma is a rarely encountered soft tissue sarcoma. Surgery with a wide surgical margin is the treatment of choice. However, there is no consensus on the treatment of head and neck synovial sarcoma in patients with cervical metastasis.Methods.A 20‐year‐old man was seen with a palpable mass in the right neck. He had been diagnosed with synovial sarcoma of the right tonsil and treated by surgery 1 and a half years before; therefore, the mass detected was thought to be a cervical metastasis of synovial sarcoma. We performed a modified radical neck dissection with no postoperative treatment. The pathological diagnosis was confirmed by detecting the SS‐specific fusion gene SYT‐SSX1.Results.The patient remains free of recurrence or metastasis 2 years and 10 months after the surgery.Conclusions.We encountered a case of head and neck synovial sarcoma with cervical metastasis that was successfully treated. © 2008 Wiley Periodicals, Inc. Head Neck, 2009
Role of proinflammatory cytokines in cisplatin‐induced vestibular hair cell damage
Authors: Kim Hyung‐Jin , So Hong‐Seob , Lee Jeong‐Han , Park Channy , Lee Jin‐Bin , Youn Myung‐Ja , Kim Se‐Jin , Yang Sei‐Hoon , Lee Kang‐Min , Kwon Kang‐Beom , Park Byung‐Hyun , Park Raekil 
Published: July 2008

AbstractBackground.Cisplatin causes the impairment of inner ear functions, including hearing and balance, through the involvement of a number of mechanisms. However, no laboratory studies have been performed on involvement of inflammation‐related events in cisplatin‐mediated vestibular dysfunction.Methods.We evaluated the secretion of proinflammatory cytokines and nuclear factor‐κB (NF‐κB) activation in cisplatin‐treated UB/UE‐1 utricular epithelial cells. We also employed immunohistochemistry to detect proinflammatory cytokines and NF‐κB expression in cisplatin‐injected mice.Results.Productions of proinflammatory cytokines significantly caused the death of UB/UE1 cells by cisplatin. Pharmacologic inhibition of mitogen‐activated protein (MAP) kinase/ERK kinase‐1 (MEK1) or extracellular signal‐regulated kinase (ERK) significantly attenuated the death of UB/UE1 cells caused by cisplatin and proinflammatory cytokines. Immunohistochemical studies revealed an increase in the expression of proinflammatory cytokines and NF‐κB in both the cristae ampullae and utricle of cisplatin‐injected mice.Conclusions.These results suggest that proinflammatory cytokines may play an important role in the pathogenesis of cisplatin‐mediated vestibulotoxicity. © 2008 Wiley Periodicals, Inc. Head Neck, 2008
An optimal water allocation for an irrigation district in Pingtung County, Taiwan
Authors: Cheng Yun , Lee Cheng‐Haw , Tan Yih‐Chi , Yeh Hsin‐Fu 
Published: July 2008

AbstractThis paper presents a linear programming model to study the conjunctive use of surface water and groundwater for optimal water allocation in Taiwan. Increasing demand for water emphasizes the proper need for effective planning and development of irrigated resources. A groundwater simulation model was performed to construct the hydrogeological structure of the regional Pingtung Plain in the southwest part of Taiwan and the optimal withdrawal of three irrigation areas in Pingtung Plain was analysed. The optimal ratios for allocating water of three canals are analysed in this research. The optimal distribution rate of each canal depends on the season, irrigation methods and crops, which are two paddy rice and one upland crop. After simulation of various scenarios, optimal simulation results show that the minimal amount of required groundwater and the maximum amount of excess water amounts in the area can be satisfied by current agricultural practices. Copyright © 2008 John Wiley & Sons, Ltd.
Gene expression analysis of a human enterocyte cell line reveals downregulation of cholesterol biosynthesis in response to short‐chain fatty acids
Authors: Alvaro Adriana , Solà Rosa , Rosales Roser , Ribalta Josep , Anguera Anna , Masana Lluís , Vallvé Joan Carles 
Published: July 2008

AbstractIt has been suggested that the short‐chain fatty acids (SCFAs) produced by anaerobic bacterial intestinal fermentation of soluble fiber may regulate lipid metabolism in intestine, thus reducing plasma cholesterol levels. However, the exact mechanism of action of SCFAs in lowering cholesterol levels is not fully understood. The aims of this study were to test the effects of SCFAs on gene expression in a human enterocyte cell line Caco‐2/TC‐7 and to validate microarray data by real‐time PCR. Human Caco‐2/TC‐7 enterocytes were cultured on transwell filter inserts and incubated with the SCFAs acetate (Ac), propionate (Pr), and butyrate (Bu). Total RNA was then isolated for microarrays and quantitative real‐time PCR analysis. Treatment of human enterocytes with Pr and Bu affects a wide variety of genes. These genes were classified according to the PANTHER classification system, and the results showed that different biological processes and metabolic pathways were modified by Pr and Bu treatment, including the intestinal cholesterol biosynthesis pathway. Differential array expression analysis showed that nine genes were downregulated in this pathway, and these results were validated by real‐time PCR. This in vitro study allowed us to identify a wide variety of biological processes and metabolic pathways affected by the SCFAs tested. Importantly, our results show that the global effect of Pr and Bu is to downregulate the expression of nine key genes involved in intestinal cholesterol biosynthesis, thus possibly inhibiting this pathway. © 2008 IUBMB IUBMB Life, 60(11): 757–764, 2008
Exposure to violence and aggression: protective roles of social support among urban African American youth
Authors: Benhorin Shira , McMahon Susan D. 
Published: July 2008

AbstractThis cross‐sectional study examined the impact of social support on the relation between exposure to violence and aggressive behavior, as reported by self, peers, and teachers. The main‐effects and stress‐buffering models of social support were tested for parents, teachers, classmates, and close friends among 127 urban, African American youth. The results demonstrate the negative impact of violence exposure on aggressive behavior and the complex roles of social support in these relations. Specifically, more perceived support from parents, teachers, and close friends was associated with lower teacher‐reported aggressive behavior, whereas classmate support buffered the impact of violence on peer‐reported aggressive behavior. These findings, multiple reporter differences, and implications for preventive interventions are discussed. © 2008 Wiley Periodicals, Inc.
Dispersive liquid–liquid microextraction followed by reversed phase HPLC for the determination of decabrominated diphenyl ether in natural water
Authors: Li Yanyan , Hu Jia , Liu Xiujuan , Fu Lingyan , Zhang Xiaojun , Wang Xuedong 
Published: July 2008

AbstractA simple, rapid, and efficient method, dispersive liquid–liquid microextraction (DLLME), has been developed for the extraction and preconcentration of decabrominated diphenyl ether (BDE‐209) in environmental water samples. The factors relevant to the microextraction efficiency, such as the kind and volume of extraction and dispersive solvent, the extraction time, and the salt effect, were optimized. Under the optimum conditions (extraction solvent: tetrachloroethane, volume, 22.0 μL; dispersive solvent: THF, volume, 1.00 mL; extraction time: below 5 s and without salt addition), the most time‐consuming step is the centrifugation of the sample solution in the extraction procedure, which is about 2 min. In this method, the enrichment factor could be as high as 153 in 5.00 mL water sample, and the linear range, correlation coefficient (r2), detection limit (S/N = 3), and precision (RSD, n = 6) were 0.001–0.5 μg/mL, 0.9999, 0.2 ng/mL, and 2.1%, respectively. This method was successfully applied to the extraction of BDE‐209 from tap, East Lake, and Yangtse River water samples; the relative recoveries were 95.8, 92.9, and 89.9% and the RSD% (n = 3) were 1.9, 2.7, and 3.5%, respectively. Comparison of this method with other methods, such as solid‐phase microextraction (SPME), and single‐drop microextraction (SDME), indicates that DLLME is a simple, fast, and low‐cost method for the determination of BDE‐209, and thus has tremendous potential in polybrominated diphenyl ethers (PBDEs) residual analysis in environmental water samples.
Microbial and algal oils: Do they have a future for biodiesel or as commodity oils?
Authors: Ratledge Colin , Cohen Zvi 
Published: July 2008

AbstractWe review the prospects of using yeasts and microalgae as sources of cheap oils that could be used for biodiesel. We conclude that yeast oils, the cheapest of the oils producible by heterotrophic microorganisms, are too expensive to be viable alternatives to the major commodity plant oils. Algal oils are similarly unlikely to be economic; the cheapest form of cultivation is in open ponds which then requires a robust, fast‐growing alga that can withstand adventitious predatory protozoa or contaminating bacteria and, at the same time, attain an oil content of at least 40% of the biomass. No such alga has yet been identified. However, we note that if the prices of the major plant oils and crude oil continue to rise in the future, as they have done over the past 12 months, then algal lipids might just become a realistic alternative within the next 10 to 15 years. Better prospects would, however, be to focus on algae as sources of polyunsaturated fatty acids.
Random Block Copolymers via Segment Interchange Olefin Metathesis
Authors: Wagner Nicole L. , Timmers Francis J. , Arriola Daniel J. , Jueptner Guenter , Landes Brian G. 
Published: July 2008

AbstractPolycarbonate/polyethylene random block copolymers (RBCs) have been produced using olefin metathesis catalysis in a process termed segment interchange metathesis. An olefin metathesis catalyst tolerant of polar functionality was added to reagent polycarbonate and polyethylene polymers which contained internal unsaturated carbon–carbon bonds. Subsequent metathesis occurred, segmenting the reagent polymers, resulting in RBCs. The block copolymers self‐assembled into microphase structures which persisted into the melt state as determined by small angle X‐ray scattering (SAXS).magnified image
Dopamine D1receptor ligands: Where are we now and where are we going
Authors: Zhang Jing , Xiong Bing , Zhen Xuechu , Zhang Ao 
Published: July 2008

AbstractThe dopamine (DA) D1receptor is the most highly expressed DA receptor subtype among the DA receptor family. Although the first DA D1receptor selective ligand SCH‐23390 (1) was introduced more than two decades ago, clinically useful D1receptor selective ligands are rare. A renewed interest was ignited in the early 1990s by Nichols and Mailman who developed dihydrexidine (27a), the first high affinity full efficacy agonist for the D1receptor. Since then, a number of D1receptor agonists with full intrinsic activity, including A‐86929 (31a), dinapsoline (32a), dinoxyline (34a), and doxanthrine (35a) were identified. These compounds all contain a conformationally rigid structure. However, the fate of such ligands for clinical use as treatments of Parkinson's disease and other related CNS disorders is not optimistic since the clinical trial with dihydrexidine (27a) was not successful. Further investigations on other compounds which are currently in the discovery stage will be crucial for determining the future of the D1receptor agonists. © 2008 Wiley Periodicals, Inc. Med Res Rev, 29, No. 2, 272–294, 2009
Length‐dependent weakness and electrophysiological signs of secondary axonal loss in chronic inflammatory demyelinating polyradiculoneuropathy
Authors: Harbo Thomas , Andersen Henning , Jakobsen Johannes 
Published: July 2008

AbstractIn chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) the pathophysiology underlying permanent muscle weakness and sensory loss was studied in 22 stabilized long‐term CIDP patients clinically characterized using isokinetic dynamometry, quantitative sensory testing, and neuropathy scores. Conduction velocity (CV), distal latency (DLAT), minimal F‐wave latency (FLAT), compound muscle action potential (CMAP), and amplitude decay between distal and proximal stimulation sites were determined in the median, ulnar, peroneal, and tibial motor nerves and sensory CV and nerve action potentials in the median and sural nerves. Amplitude of CMAP and the DLAT were related to quantitative muscle strength, whereas CV, FLAT, amplitude decay, and dispersion were not consistently related to strength. Furthermore, CMAP and muscle strength were significantly more reduced distally than proximally. In conclusion, the electrophysiological signs of axonal loss and the associated length‐dependent muscle weakness suggest secondary axonal loss in addition to primary demyelination in CIDP. Muscle Nerve, 2008
Reference values for 50‐kHZ electrical impedance myography
Authors: Rutkove Seward B. , Fogerson Patricia M. , Garmirian Lindsay P. , Tarulli Andrew W. 
Published: July 2008

AbstractElectrical impedance myography (EIM) is a method for non‐invasively and quantitatively assessing muscle health, in which the major outcome parameter, phase (θ), decreases in diseased states. In order to create a set of normal reference values, we performed 50‐kHZ EIM in 5 muscles of 87 healthy individuals, using θ as the major outcome variable. Because the distributions of data were mostly skewed, logarithmic transformations were performed, and the resulting data were fitted to quadratic functions. The lower limit of normal was set by plotting the lower 95% confidence interval of the curve for each muscle and then identifying age‐specific reference values. We found that the distribution of data was similar to that for other neurophysiologic parameters. The lower limit of normal was easily defined, and relatively few values fell below the proposed lower limit. By using commercially available bioimpedance devices, these values will allow other investigators to explore the application of 50‐kHZ EIM in clinical neuromuscular disease research. Muscle Nerve, 2008
Detection of circulating fetal cells utilizing automated microscopy: potential for noninvasive prenatal diagnosis of chromosomal aneuploidies
Authors: Seppo Antti , Frisova Veronika , Ichetovkin Ilia , Kim Youngmin , Evans Mark I. , Antsaklis Aristeidis , Nicolaides Kypros H. , Tafas Triantafyllos , Tsipouras Petros , Kilpatrick Michael W. 
Published: July 2008

AbstractObjectiveAs fetal cells can be indisputably identified through detection of Y FISH signals, we utilized an automated microscopy system developed to identify and enumerate cells bearing X and Y FISH signals. We further investigated the potential of fetal hemoglobin expression as a gender independent marker for automated identification of fetal cells.MethodFor FISH‐based scanning, verified fetal cells were identified based on the presence of a single X‐signal and individual signals for each of the two Y FISH probes. For cell identification based on fetal hemoglobin expression, putative fetal cells were verified based on the presence of signals for anti‐γ or anti‐ε globin antibody, and FISH signals for the X‐ and Y‐ chromosomes.ResultsFetal cells were identified, by FISH‐based scanning, in 28 of the 29 maternal samples from pregnancies with male fetuses. Simple density gradient centrifugation achieved a 3‐ to 5‐fold increase in the number of fetal cells detected.ConclusionAutomated microscopy identified fetal cells in both first and second trimester maternal blood samples. Although we were unable to detect fetal erythroblasts in numbers sufficient for clinical diagnosis, the ability to reliably detect fetal cells by FISH‐based scanning opens the possibility for prenatal detection of chromosomal aberrations utilizing circulating fetal cells. Copyright © 2008 John Wiley & Sons, Ltd.