bluuebunny/crossref_metadata_2025 huggingface dataset:
Progress in Pharmacogenomics and Its Promise for Medicine
Authors: Blake Charles A. , Sobel Burton E.
Published: October 2008

Pharmacogenomics addresses the impacts of diverse and multiple genes in populations as determinants of responses of individual patients to drugs. The field has its roots in basic science, and is pivotal in drug development, elucidation of therapeutic efficacy, and constraining the risks of adverse drug reactions. Regulatory agencies are relying increasingly on pharmacogenomics for identification of patients who are particularly likely to benefit from treatment with specific agents and exclusion of those at risk of adverse drug reactions. Practical applications of pharmacogenomics already abound particularly in the use of drugs acting on the central nervous system and on the cardiovascular system. The Society for Experimental Biology and Medicine (SEBM) is proud and pleased to have devoted its 2008 symposium, presented at the annual Experimental Biology meeting in San Diego on April 6, 2008, to advances in pharmacogenomics with emphasis on drug development, regulatory agency considerations, and clinical applications.
A PTAS For The k-Consensus Structures Problem Under Squared Euclidean Distance
Authors: Li Shuai Cheng , Ng Yen Kaow , Zhang Louxin
Published: October 2008

In this paper we consider a basic clustering problem that has uses in bioinformatics. A structural fragment is a sequence of l points in a 3D space, where l is a fixed natural number. Two structural fragments f1 and f2 are equivalent if and only if f1 = f2 x R + τ under some rotation R and translation τ . We consider the distance between two structural fragments to be the sum of the squared Euclidean distance between all corresponding points of the structural fragments. Given a set of n structural fragments, we consider the problem of finding k (or fewer) structural fragments g1, g2, ... , gk, so as to minimize the sum of the distances between each of f1, f2, ... , fn to its nearest structural fragment in g1, ... , gk. In this paper we show a polynomial-time approximation scheme (PTAS) for the problem through a simple sampling strategy.
A Multivariate Model for Coastal Water Quality Mapping Using Satellite Remote Sensing Images
Authors: Su Yuan-Fong , Liou Jun-Jih , Hou Ju-Chen , Hung Wei-Chun , Hsu Shu-Mei , Lien Yi-Ting , Su Ming-Daw , Cheng Ke-Sheng , Wang Yeng-Fung
Published: October 2008

his study demonstrates the feasibility of coastal water quality mapping using satellite remote sensing images. Water quality sampling campaigns were conducted over a coastal area in northern Taiwan for measurements of three water quality variables including Secchi disk depth, turbidity, and total suspended solids. SPOT satellite images nearly concurrent with the water quality sampling campaigns were also acquired. A spectral reflectance estimation scheme proposed in this study was applied to SPOT multispectral images for estimation of the sea surface reflectance. Two models, univariate and multivariate, for water quality estimation using the sea surface reflectance derived from SPOT images were established. The multivariate model takes into consideration the wavelength-dependent combined effect of individual seawater constituents on the sea surface reflectance and is superior over the univariate model. Finally, quantitative coastal water quality mapping was accomplished by substituting the pixel-specific spectral reflectance into the multivariate water quality estimation model.
Current status of the habitat and population of the black howler monkey (Alouatta pigra) in Balancán, Tabasco, Mexico
Authors: Pozo‐Montuy Gilberto , Serio‐Silva Juan Carlos , Bonilla‐Sánchez Yadira M. , Bynum Nora , Landgrave Rosario
Published: October 2008

We evaluated the habitat and populations of the black howler monkey (Alouatta pigra) in the municipality of Balancán, Tabasco, southeastern Mexico, using a combination of field surveys and remotely sensed data. We identified 21,937 ha of remnant vegetation composed of 1,348 fragments. Fragments separated by up to 200 m were grouped into “clusters” of fragments in accordance with the maximum observed open distance crossed byA. pigra. A total of 11% or 84 of the 772 clusters identified through remote sensing were selected at random, and for these we determined the vegetation type, canopy height, area, and distance to the closest human settlement. In these same 84 clusters, which included a total area of 9,817 ha, from October to June of 2006 we located a total of 1,064 black howler monkeys, including 228 troops and 49 solitary monkeys.A. pigrawas found in 62 (74.7%) of all clusters visited, with a cumulative area of 6,032 ha. Troops varied in size from 2 to 15 individuals (average 6.0±2.9 ind/troop). Adults were 67% (n=716) of detected individuals, whereas juveniles were 20.5% (n=218) and infants were 12.5% (n=133). We found black howlers to occur at an ecological density of 10.8 ind/km2, which is low in comparison withA. pigrain other fragmented and conserved sites. We found a statistically significant relationship between the area of clusters and the abundance of howler monkeys (r2=0.2,F=10.47, gl=3,P=0.002). In addition, the probability of findingA. pigrawas greater in secondary vegetation, riparian vegetation, tropical dry forest, undisturbed tropical oak forest, and palm forest (F=12, gl=3,P<0.0001), as compared with disturbed tropical oak forest. Our results provide data on the distribution, abundance, and population structure of black howler monkeys in a fragmented landscape in the southeast of Mexico. These data are a necessary prerequisite for conservation planning for this species. Am. J. Primatol. 70:1169–1176, 2008. © 2008 Wiley‐Liss, Inc.
Enantiocomplementary Enzymes: Classification, Molecular Basis for Their Enantiopreference, and Prospects for Mirror‐Image Biotransformations
Authors: Mugford Paul F. , Wagner Ulrike G. , Jiang Yun , Faber Kurt , Kazlauskas Romas J.
Published: October 2008

One often‐cited weakness of biocatalysis is the lack of mirror‐image enzymes for the formation of either enantiomer of a product in asymmetric synthesis. Enantiocomplementary enzymes exist as the solution to this problem in nature. These enzyme pairs, which catalyze the same reaction but favor opposite enantiomers, are not mirror‐image molecules; however, they contain active sites that are functionally mirror images of one another. To create mirror‐image active sites, nature can change the location of the binding site and/or the location of key catalytic groups. In this Minireview, X‐ray crystal structures of enantiocomplementary enzymes are surveyed and classified into four groups according to how the mirror‐image active sites are formed.
N,O‐chelate aluminum and zinc complexes: synthesis and catalysis in the ring‐opening polymerization of ε‐caprolactone
Authors: Zhang Cheng , Wang Zhong‐Xia
Published: October 2008

Reaction between 2‐(1H‐pyrrol‐1‐yl)benzenamine and 2‐hydroxybenzaldehyde or 3,5‐di‐tert‐butyl‐2‐hydroxybenzaldehyde afforded 2‐(4,5‐dihydropyrrolo[1,2‐a]quinoxalin‐4‐yl)phenol (HOL1NH, 1a) or 2,4‐di‐tert‐butyl‐6‐(4,5‐dihydropyrrolo[1,2‐a]quinoxalin‐4‐yl)phenol (HOL2NH, 1b). Both 1a and 1b can be converted to 2‐(H‐pyrrolo[1,2‐a]quinoxalin‐4‐yl)phenol (HOL3N, 2a) and 2,4‐di‐tert‐butyl‐6‐(H‐pyrrolo[1,2‐a]quinoxalin‐4‐yl)phenol (HOL4N, 2b), respectively, by heating 1a and 1b in toluene. Treatment of 1b with an equivalent of AlEt3 afforded [Al(Et2)(OL2NH)] (3). Reaction of 1b with two equivalents of AlR3 (R = Me, Et) gave dinuclear aluminum complexes [(AlR2)2(OL2N)] (R = Me, 4a; R = Et, 4b). Refluxing the toluene solution of 4a and 4b, respectively, generated [Al(R2)(OL4N)] (R = Me, 5a; R = Et, 5b). Complexes 5a and 5b were also obtained either by refluxing a mixture of 1b and two equivalents of AlR3 (R = Me, Et) in toluene or by treatment of 2b with an equivalent of AlR3 (R = Me, Et). Reaction of 2a with an equivalent of AlMe3 afforded [Al(Me2)(OL3N)] (5c). Treatment of 1b with an equivalent of ZnEt2 at room temperature gave [Zn(Et)(OL2NH)] (6), while reaction of 1b with 0.5 equivalent of ZnEt2 at 40 °C afforded [Zn(OL2NH)2] (7). Reaction of 1b with two equivalents of ZnEt2 from room temperature to 60 °C yielded [Zn(Et)(OL4N)] (8). Compound 8 was also obtained either by reaction between 6 and an equivalent of ZnEt2 from room temperature to 60 °C or by treatment of 2b with an equivalent of ZnEt2 at room temperature. Reaction of 2b with 0.5 equivalent of ZnEt2 at room temperature gave [Zn(OL4N)2] (9), which was also formed by heating the toluene solution of 6. All novel compounds were characterized by NMR spectroscopy and elemental analyses. The structures of complexes 3, 5c and 6 were additionally characterized by single‐crystal X‐ray diffraction techniques. The catalysis of complexes 3, 4a, 5a–c, 6 and 8 toward the ring‐opening polymerization of ε‐caprolactone was evaluated. Copyright © 2008 John Wiley & Sons, Ltd.
A novel approach to consolidation of historical limestone: the calcium alkoxides
Authors: Favaro M. , Tomasin P. , Ossola F. , Vigato P. A.
Published: October 2008

Potential utilization of calcium alkoxides as stone consolidants was considered. Reaction of Ca(OCH3)2, Ca(OCH2CH3)2(CH3CH2OH)4 and Ca[OCH(CH3)2]2 with the atmosphere in different experimental conditions was studied. The reaction produced CaCO3 and two different pathways seem to be involved, the first taking place through CO2 insertion into the Ca–O bond of Ca(OR)2 species with formation of an alkylcarbonate derivative, subsequently transformed into CaCO3 through ROH elimination; the second takes place through hydrolysis of Ca(OR)2 to Ca(OH)2, which is then carbonated to CaCO3. The vaterite/calcite ratios found in the final CaCO3 vary considerably with the experimental conditions adopted. Investigations demonstrated the potentiality of Ca(OCH3)2 to act as a stone consolidant. In fact, impregnation of a porous substrate, simulating the deteriorated stone, with a methanol solution of Ca(OCH3)2, produced a crystalline vaterite film, which gradually filled all the pores and cavities of substrate and seems to fulfil the necessary requirements for a consolidant. Copyright © 2008 John Wiley & Sons, Ltd.
Tin‐coupled star‐shaped block copolymer of styrene and butadiene (II) properties and application
Authors: Feng Huadong , Zhang Xingying , Zhao Suhe
Published: October 2008

A novel tin‐coupled star‐shaped block copolymer (SB‐B)4Sn was synthesized by anionic polymeric techniques. This new copolymer exhibited two different types: One was star‐shaped polybutadiene‐b‐poly(butadiene‐ran‐styrene) (S‐PB‐PSB), and the other was star‐shaped polybutadiene‐b‐poly(butadiene‐ran‐styrene)‐b‐polystyrene (S‐PB‐PSB‐PS). In this article, properties of (SB‐B)4Sn were contrasted with that of tin‐coupled star‐shaped random styrene‐butadiene rubber (S‐SBR) and S‐SBR/cis‐BR blend rubbers. Physical property testing results showed that (SB‐B)4Sn possessed good mechanical properties like S‐SBR. Rheological study indicated that these star‐shaped block copolymers had good processing properties. Rubber processing analyzer (RPA) spectra showed that the dispersion of additives in (SB‐B)4Sn and S‐SBR/cis‐BR blend rubber was much better than that in S‐SBR. Dynamic mechanical thermal analyzer (DMTA) spectra showed that (SB‐B)4Sn had a good combination of low rolling resistance and high wet skid resistance, which made it satisfactory materials to produce high performance tire tread. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
New method of determining miscibility in binary polymer blends through hydrodynamic interaction: The free volume approach
Authors: Ranganathaiah C. , Kumaraswamy G. N.
Published: October 2008

A new method has been developed to determine the probability of miscibility in binary polymer blends through hydrodynamic interaction. This is achieved by the measurement of the free volume content in blends of carefully selected systems—styrene acrylonitrile (SAN)/poly(methyl methacrylate) (PMMA), PMMA/poly(vinyl chloride) (PVC), and PVC/polystyrene (PS)—with positron annihilation lifetime spectroscopy. The free volume content can predict the miscible/immiscible nature of the blends but provides no information on the extent of miscibility for different compositions of the blends. We have generalized a model used to understand the viscometric behavior of polymer/solvent systems to polymer/polymer systems through the free volume approach. This model provides two important parameters: a geometric factor (γ) and a hydrodynamic interaction parameter (α). γ depends on the molecular architecture, whereas α accounts for the excess friction at the interface between the constituents of the blend, and we propose that α can serve as a precursor to miscibility in a system and indicate which composition produces a high probability of miscibility. The efficacy of this proposition has been checked with measured free volume data for the three blend systems. The SAN/PMMA system produces a maximum α value of −209 at 20% PMMA; PVC/PMMA produces a maximum α value of −57 at 10% PMMA. Interestingly, for the PS/PVC system, α is close to zero throughout the entire concentration range. Therefore, we infer that α is perhaps an appropriate parameter for determining the composition‐dependent probability of miscibility in binary blend systems. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Biodegradable composites based on starch/EVOH/glycerol blends and coconut fibers
Authors: Rosa Morsyleide F. , Chiou Bor‐sen , Medeiros Eliton S. , Wood Delilah F. , Mattoso Luiz H. C. , Orts William J. , Imam Syed H.
Published: October 2008

Unripe coconut fibers were used as fillers in a biodegradable polymer matrix of starch/ethylene vinyl alcohol (EVOH)/glycerol. The effects of fiber content on the mechanical, thermal, and structural properties were evaluated. The addition of coconut fiber into starch/EVOH/glycerol blends reduced the ductile behavior of the matrix by making the composites more brittle. At low fiber content, blends were more flexible, with higher tensile strength than at higher fiber levels. The temperature at the maximum degradation rate slightly shifted to lower values as fiber content increased. Comparing blends with and without fibers, there was no drastic change in melt temperature of the matrix with increase of fiber content, indicating that fibers did not lead to significant changes in crystalline structure. The micrographs of the tensile fractured specimens showed a large number of holes resulting from fiber pull‐out from the matrix, indicating poor adhesion between fiber and matrix. Although starch alone degraded readily, starch/EVOH/glycerol blends exhibited much slower degradation in compost. Composites produced 24.4–28.8% less CO2 compared with starch in a closed‐circuit respirometer. Addition of increasing amount of fiber in starch/EVOH/glycerol composite had no impact on its biodegradation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
A monoclonal antibody that inhibits translation in Sf21 cell lysates is specific for glyceraldehyde‐3‐phosphate dehydrogenase
Authors: Van Meter Kipp E. , Stuart Melissa K.
Published: October 2008

Monoclonal antibody (Mab) 8B7 was shown in a previous study to inhibit protein translation in lysates of Sf21 cells. The antibody was thought to be specific for a 60‐kDa form of elongation factor‐1 alpha (EF‐1α), primarily because the antigen immunoprecipitated by Mab 8B7 cross‐reacted with Mab CBP‐KK1, an antibody generated to EF‐1α from Trypanosoma brucei. The purpose of the current study was to investigate further the antigenic specificity of Mab 8B7. The concentration of the 60‐kDa antigen relative to total cellular protein proved insufficient for its definitive identification. However, subcellular fractionation of Sf21 cells yielded an additional protein of 37 kDa in the cytosolic and microsomal fractions that was reactive with Mab 8B7. The 37‐kDa protein could be easily visualized by colloidal Coomassie Blue G‐250 staining as a series of pI 6.9–8.4 spots on two‐dimensional gels. Excision of an abundant immunoreactive spot enabled identification of the protein as glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) by matrix‐assisted laser desorption/ionization–mass spectrometry (MALDI‐MS) and protein database searching. Subsequent immunoblotting of purified rabbit skeletal muscle GAPDH with Mab 8B7 confirmed the antibody's specificity for GAPDH. Besides the pivotal role GAPDH plays in glycolysis, the enzyme has a number of noncanonical functions, including binding to mRNA and tRNA. The ability of Mab 8B7 to disrupt these lesser‐known functions of GAPDH may account for the antibody's inhibitory effect on in vitro translation. Arch. Insect Biochem. Physiol. 69:107‐117, 2008. © 2008 Wiley‐Liss, Inc.
Vinylic CH Borylation of Cyclic Vinyl Ethers with Bis(pinacolato)diboron Catalyzed by an Iridium(I)‐dtbpy Complex
Authors: Kikuchi Takao , Takagi Jun , Isou Hironori , Ishiyama Tatsuo , Miyaura Norio
Published: October 2008

Borylation of the vinylic CH bond of 1,4‐dioxene, 2,3‐dihydrofuran, 3,4‐dihydro‐2H‐pyran and their γ‐substituted analogs was carried out in the presence of bis(pinacolato)diboron (B2pin2) and a catalytic amount of IrI‐dtbpy (dtbpy=4,4′‐di‐tert‐butyl‐2,2′‐bipyridine) complex. The two boron atoms in B2pin2 participated in the coupling, thus giving two equivalents of the coupling product from one equivalent of B2pin2. The borylation of 1,4‐dioxene in hexane resulted in 81 % yield at room temperature. The borylation of 2,3‐dihydrofurans at 80 °C in octane suffered from low regioselectivity, and gave a mixture of α‐ and β‐coupling products even for hindered γ‐disubstituted analogs, but γ‐substituted analogs of 3,4‐dihydro‐2H‐pyran achieved high α‐selectivity, giving single coupling products. This protocol was applied to the syntheses of a key precursor of vineomycinone B2 methyl ester and other C‐substituted D‐glucals by borylation of protected D‐glucals with B2pin2 to give α‐boryl glucal followed by cross‐coupling with haloarenes, benzyl bromide, and allyl bromide. A catalytic cycle that involves the oxidative addition of sp2 CH bond to iridium(III)‐trisboryl intermediate as the rate‐determining step has been proposed.
Fetal death persists through recurrent pregnancies in mice following Ljungan virus infection
Authors: Samsioe Annika , Sjöholm Åke , Niklasson Bo , Klitz William
Published: October 2008

OBJECTIVES: Laboratory mice infected with Ljungan virus (LV) early in pregnancy suffer from perinatal death. Here we investigate the persistence of that effect through the outcome of consecutive pregnancies in LV‐infected mice. STUDY DESIGN: CD‐1 mice were infected while pregnant and their adult female offspring were followed in parallel with uninfected control mice during repeated pregnancies. Three mating attempts resulted in two or three pregnancies per dam. The outcome of the last pregnancy was carefully monitored. RESULTS: Both the dams infected as adults and their adult female offspring suffered perinatal deaths during the last pregnancy which occurred approximately 6 months after the original LV exposure and acute infection. The non‐infected control animals experienced no perinatal death. CONCLUSIONS: Perinatal death persists across recurrent pregnancies in this mouse model of LV infection, both in animals infected as adults and in females exposed to the virus in utero. This implies that LV persists in mice long after intial infection, and is maintained in a quiescent state but can remain pathogenic in later pregnancies. Birth Defects Res (Part B) 83:507‐510, 2008. © 2008 Wiley‐Liss, Inc.
Lack of adaptive response of gamma radiation for protection against neutron‐induced teratogenesis
Authors: Lee Hae‐June , Kim Joong‐Sun , Song Myoung‐Sub , Seo Heung‐Sik , Moon Changjong , Kim Jong‐Choon , Jo Sung‐Kee , Kim Sung‐Ho
Published: October 2008

BACKGROUND:Although there are some reports on neutron teratology, there is little information on the adaptive response of gamma radiation for protection against neutron‐induced teratogenesis. This study examined whether or not a low dose of gamma radiation can induce an adaptive response in mouse fetuses exposed to a subsequent dose of neutrons in vivo.METHODS:Pregnant ICR mice were exposed to a priming dose of 0.3 Gy (0.9 Gy/min) of gamma rays on day 10.5 of gestation and challenged with 0.8 Gy (0.94 Gy/minute) of neutrons 24 hlater. The mice were sacrificed on day 18.5 of gestation. The fetuses were examined for mortality, growth retardation, and other morphologic abnormalities.RESULTS:The tail length in the 0.3 Gy of gamma rays + 0.8 Gy of neutrons group was significantly shorter than in the 0.8 Gy of neutrons group. Although there was no significant difference compared with the 0.8 Gy of neutrons group, the number of live fetuses in the 0.3 Gy of gamma rays +0.8 Gy of neutrons group was lower. There was no evidence of primed exposure‐related reductions in the malformed fetuses. Although there was no significant difference compared with the unprimed group, the number of malformed offspring in the primed group was higher. Furthermore, the incidence of kinked tail and adactyly was significantly higher in the primed mice than in the unprimed mice.CONCLUSIONS:Overall, this study shows that exposure to 0.3 Gy of gamma rays failed to induce an adaptive response of fetogenesis to a neutron challenge dose.Birth Defects Res (Part B)83:502‐506, 2008. © 2008 Wiley‐Liss, Inc.
Simultaneous determination of 18α‐ and 18β‐glycyrrhetic acid in human plasma by LC‐ESI‐MS and its application to pharmacokinetics
Authors: Zou Qiaogen , Wei Ping , Li Jing , Ge Zheng‐xiang , Ouyang Pingkai
Published: October 2008

A highly sensitive and selective LC‐ESI‐MS was developed, validated for the simultaneous determination of 18α‐glycyrrhetic acid (α‐GA) and 18β‐glycyrrhetic acid (β‐GA) for pharmacokinetic studies in healthy subjects. Sample preparation was performed by liquid–liquid extraction with ethyl acetate and the separations were achieved using a C18column with the mobile phase composed of 10 mmol/L ammonium acetate solution–methanol–acetonitrile (40:36:24, v/v/v) at a flow rate of 1 mL/min. The internal standard was honokiol and the epimers were quantified using a single quadrupole mass spectrometer employing ESI in the negative ion mode. The separation factor,α, was 1.512 forα‐ andβ‐GA. The standard curves were linear for both epimers with coefficients of determination (r ≥ 0.9998) over the concentration range of 1–150 ng/mL. The precision and accuracy were ≤ 4.33 and ≤ 6.57%, respectively. The mean plasma extraction recoveries were 82.23 ± 1.91 and 84.29 ± 2.09% forα‐GA andβ‐GA, respectively. The assay was successfully applied to evaluation of the pharmacokinetic properties ofα‐GA andβ‐GA from 19 volunteers who had received oral administration of diammonium glycyrrhizinate capsules. The initial data suggest that glycyrrhizin metabolizes to glycyrrhetic acid fairly slowly and the elimination ofα‐GA is slower than that ofβ‐GA. Copyright © 2008 John Wiley & Sons, Ltd.
Identification of key metabolites of tectorigenin in rat urine by HPLC‐MSn
Authors: Zhang Wei‐Dong , Yang Xiao‐Lin , Lei‐Xu  , Cao Jun , Li Ping , Yang Zhong‐Lin
Published: October 2008

This is a report about the identification of key metabolites of tectorigenin in rat urine using high‐performance liquid chromatography–electrospray ionization ion trap tandem mass spectrometric method (HPLC‐ESI‐MSn). Six healthy rats were administered a single dose (80 mg/kg) of tectorigenin by oral gavage. Urine was sampled for 0–24 h and centrifuged at 12,000 rpm for 10 min to obtain the supernatants, then the supernatants were purified by solid‐phase extraction with a C18 cartridge. The chromatographic separation was carried out on a reversed‐phase C18 column with a gradient elution program whereas acetonitrile–0.1% formic acid water was used as mobile phase. Mass spectra were acquired in negative ionization mode and a data‐dependant scan was used for the identification of the key metabolites of tectorigenin in the urine samples. As a result, four phase II metabolites and the parent drug tectorigenin were found and identified in rat urine for the first time. Copyright © 2008 John Wiley & Sons, Ltd.
Simultaneous determination of the flavonoid aglycones diosmetin and hesperetin in human plasma and urine by a validated GC/MS method:in vivometabolic reduction of diosmetin to hesperetin
Authors: Spanakis Marios , Kasmas Stamatis , Niopas Ioannis
Published: October 2008

Diosmetin and hesperetin are the aglycones of the flavonoid glycosides diosmin and hesperidin which occur naturally in citrus fruit. A GC/MS method for the simultaneous determination of diosmetin and hesperetin in human plasma and urine has been developed and validated. The method was linear in the 2–300 ng/mL concentration range for both diosmetin and hesperetin in plasma and urine (r >0.999). The precision of the method was better than 6.01 and 7.16% for diosmetin and hesperetin, respectively, and the accuracy was 96.76–100.40% and 95.00–105.50% for diosmetin and hesperetin, respectively. The lower limit of quantitation was found to be 2 ng/mL for both analytes in plasma and urine. Recovery of diosmetin, hesperetin and internal standard naringenin was greater than 82.5%. The method has been applied for the determination of diosmetin and hesperetin in plasma and urine samples obtained from a healthy male subject following a single oral 1000 mg dose of the flavonoid glycoside diosmin. The presence of hesperetin in plasma and urine samples indicates the metabolic reduction of diosmetin to its flavanone analogue hesperetin through reduction of the 2,3 double bond of the C‐ring by the enzymes of bacteria of the intestinal microflora. Copyright © 2008 John Wiley & Sons, Ltd.
Synchronization of the Fungal and the Plant Circadian Clock by Light
Authors: Kozma‐Bognár László , Káldi Krisztina
Published: October 2008

Circadian clocks are endogenous time keeping devices that provide temporal control of physiology in accordance with predicted daily changes in the environment. Photoentrainment is the process that synchronizes circadian clocks‐and thereby clock‐controlled gene expression and physiology‐to the environmental day/night cycles. Light is primarily detected by specialized photoreceptors that are coupled—directly or through other signaling components—to the rhythm‐generating oscillator. As a consequence, the expression, the activity or the stability of oscillator components are altered, resulting in a change of phase and/or pace of the oscillator. In this review our present knowledge about light absorption/transduction and light‐induced modifications of oscillator components in Neurospora crassa and Arabidopsis thaliana is summarized. These systems provide a basis for understanding the molecular mechanisms of entrainment in the fungal and plant circadian systems.
Cobalt‐ and Nickel‐Catalyzed Regio‐ and Stereoselective Reductive Coupling of Alkynes, Allenes, and Alkenes with Alkenes
Authors: Jeganmohan Masilamani , Cheng Chien‐Hong
Published: October 2008

Transition‐metal‐catalyzed coupling of two different CC π components through a metallacycle intermediate is a highly atom economical method to construct CC bonds in organic synthesis. The metal‐catalyzed coupling of an alkene and alkyne generally gives an Alder‐ene or reductive coupling product. In this article, we focus on the cobalt‐ and nickel‐catalyzed reductive coupling of alkynes, allenes, and alkenes with alkenes. These reductive coupling reactions provide convenient methods for the synthesis of various alkenes, dienes, functionalized alkanes, lactones, lactams, and cyclic alcohols in a highly regio‐ and stereoselective manner. A chemselective formation of metallacyclopentene intermediate from the two different CC π components and a low‐valence metal species plays a key role for the high regio‐ and stereoselectivity of the catalytic reaction.
Cephalosol: An Antimicrobial Metabolite with an Unprecedented Skeleton from Endophytic Cephalosporium acremonium IFB‐E007
Authors: Zhang Hua Wei , Huang Wu Yang , Chen Jing Rong , Yan Wei Zhong , Xie Dai Qian , Tan Ren Xiang
Published: October 2008

Cephalosol (1), a potent antimicrobial secondary metabolite with a new carbon skeleton, was characterized from the culture of Cephalosporium acremonium IFB‐E007 that used to reside as an endophyte in Trachelospermum jasminoides (Apocynaceae). Its structure and absolute configuration were unambiguously determined by spectroscopic and computational approaches.
A Phosphotyrosine‐Imprinted Polymer Receptor for the Recognition of Tyrosine Phosphorylated Peptides
Authors: Emgenbroich Marco , Borrelli Cristiana , Shinde Sudhirkumar , Lazraq Issam , Vilela Filipe , Hall Andrew J. , Oxelbark Joakim , De Lorenzi Ersilia , Courtois Julien , Simanova Anna , Verhage Jeroen , Irgum Knut , Karim Kal , Sellergren Börje
Published: October 2008

Hyperphosphorylation at tyrosine is commonly observed in tumor proteomes and, hence, specific phosphoproteins or phosphopeptides could serve as markers useful for cancer diagnostics and therapeutics. The analysis of such targets is, however, a challenging task, because of their commonly low abundance and the lack of robust and effective preconcentration techniques. As a robust alternative to the commonly used immunoaffinity techniques that rely on phosphotyrosine(pTyr)‐specific antibodies, we have developed an epitope‐imprinting strategy that leads to a synthetic pTyr‐selective imprinted polymer receptor. The binding site incorporates two monourea ligands placed by preorganization around a pTyr dianion template. The tight binding site displayed good binding affinities for the pTyr template, in the range of that observed for corresponding antibodies, and a clear preference for pTyr over phosphoserine (pSer). In further analogy to the antibodies, the imprinted polymer was capable of capturing short tyrosine phosphorylated peptides in the presence of an excess of their non‐phosphorylated counterparts or peptides phosphorylated at serine.
Filteroptimierung auf Basis von CFD‐Berechnungen
Authors: Nikolaus K. , Ripperger S. , Tichy J. W.
Published: October 2008

Computational Fluid Dynamics (CFD) ist ein sehr effizientes und in der Verfahrenstechnik zunehmend verbreitetes Werkzeug zur Entwicklung und Optimierung von Apparaten und Maschinen. Im Folgenden wird die Anwendung der Methode zur Optimierung des Strömungsverlaufs innerhalb der komplexen Geometrie eines kontinuierlich betriebenen Drucktrommelfilters vorgestellt.
Einschluss von Cyclodextrin durch kombinierte Dispergierung und Reagglomeration nanoskaliger Partikel
Authors: Sauter C. , Schuchmann H. P. , Bräse S.
Published: October 2008

Zahlreiche Entwicklungsprojekte in der pharmazeutischen Industrie werden aufgrund einer mangelhaften Wirkung des Arzneimittels eingestellt. Der Grund hierfür liegt oftmals in der unzureichenden Bioverfügbarkeit des Wirkstoffes, der häufig nicht direkt am Wirkort und in nicht ausreichenden oder zu hohen Konzentrationen freigesetzt wird. Während des Herstellungsprozesses können Nanopartikel meist nicht stabilisiert werden und lagern sich zu großen, stabilen Agglomeraten zusammen. Für die Bildung wirkstoffbeladener, nanostrukturierter Trägeragglomerate ist es erforderlich, den Wirkstoff in die poröse Agglomeratstruktur einzubinden, um anschließend eine gezielte Freisetzung zu erhalten. Eine möglichst vollständige Dispergierung und Desagglomeration der Partikelagglomerate ist aus diesem Grunde unumgänglich. Im vorliegenden Beitrag wird die technische Machbarkeit zur Erzeugung wirkstoffbeladener, nanostrukturierter Trägeragglomerate vorgestellt. Die Ergebnisse zeigen, dass Dispergierung und Reagglomeration zeitlich getrennt voneinander ablaufen und somit eine gezielte Beladung mit z. B. Cyclodextrin möglich ist.
Strömungs‐ und Trennverhalten von Tellerseparatoren zur Abscheidung von Ölnebelaerosolen, Untersuchungen zum Rotor/Rotor‐Konzept
Authors: Piesche M. , Zink A. , Schütz S.
Published: October 2008

In dieser Arbeit werden allgemeingültige Gesetzmäßigkeiten zum Strömungsverhalten und zur Tropfenabscheidung in Tellerseparatoren vorgestellt. Das geometrische Apparatekonzept orientiert sich am Aufbau klassischer Tellerseparatoren (Rotor/Rotor‐Konzept). Untersucht werden die Wechselwirkungen zwischen Strömungsverhalten, Druckverlust, Verteilung des Rohgases auf die einzelnen Tellerspalte und dem Gesamttrenngrad. Die Berechnung des Strömungsverhaltens erfolgt auf Basis der Finite‐Volumen‐Methode. Unter Zugrundelegung eines bekannten Strömungsfeldes werden die Bewegungen der Tropfen jeweils einzeln verfolgt, was der Betrachtungsweise des Euler‐Lagrange‐Verfahrens entspricht. Ein analytisches Modell wird entwickelt, das neben der Berechnung des Trenngrades auch die Bestimmung der Volumenstromverteilung und des Druckabfalls erlaubt. Dieses Näherungsverfahren versteht sich als Ergänzung zu einer Auslegung mittels einer numerisch gewonnenen universellen Trenngradkurve und dient zugleich zur Minimierung aufwändiger CFD‐Berechnungen. Betrachtet werden die einzelnen Strömungsgebiete im Tellerseparator als ein Netzwerk, das auf der Unterteilung in Maschen und Knoten basiert. Für jeden Knoten gilt die Erhaltung des Gesamtvolumenstroms und für jede Masche muss die Summe aller Druckänderungen gleich null sein. Die Ergebnisse der analytischen Berechnungsmethode zeigen sowohl für die Volumenstromverteilung als auch für die Separatortrenngrade eine gute Übereinstimmung mit den Daten der numerischen Strömungssimulation. Die in diesem Zusammenhang berechneten Druckänderungen werden ebenfalls durch das Experiment bestätigt. Damit gelingt ein umfassendes Apparate‐Scale‐up unter Berücksichtigung aller wesentlichen betrieblichen, stofflichen und geometrischen Einflussgrößen einschließlich des Tellerwinkels und des Radienverhältnisses der Teller.
Verfahren zur selektiven Herstellung von linearem Diglycerin
Authors: Richter M. , Eckelt R. , Martin A. , Krisnandi Y. K.
Published: October 2008

Glycerin wird unter reaktiven Vakuum‐Rückflussbedingungen an einem superaciden polymeren Katalysator bei einer Temperatur von 150 °C mit hoher Selektivität zu linearem Diglycerin umgesetzt. Mit dem vorgestellten Verfahren lassen sich – im Gegensatz zum Rührkessel – hohe Selektivitäten an linearem Diglycerin auch bei hohen Glycerin‐Umsätzen aufrecht erhalten.
Untersuchungen von Filmströmungen mittels eines neuartigen Micro Particle Image Velocimetry Messverfahrens
Authors: Paschke S. , Repke J.‐U. , Wozny G.
Published: October 2008

Der Wärme‐ und Stoffübergang in Packungskolonnen wird erheblich durch die komplexe Fluiddynamik der flüssigen Phase beeinflusst, für deren tiefergehendes Verständnis zwingend Informationen über das Geschwindigkeitsfeld benötigt werden. Zu diesem Zweck wurde eine neue μPIV (Micro Particle Image Velocimetry)‐Messmethode entwickelt, bei der das Geschwindigkeitsprofil durch die bewegte wellige Oberfläche gemessen wird, sodass erstmalig Analysen auf nicht transparenten Packungsmaterialien ermöglicht werden.
CO2‐Absorption mit Aminlösung per Membrankontaktor
Authors: Epp B. , Fahlenkamp H. , Stankewitz C.
Published: October 2008

Zur Minimierung des Raumbedarfs von CO2‐Rauchgaswäschen wird die druckbetriebene Membranabsorption untersucht. Diese ermöglicht einen dispersionsfreien Gas/Flüssig‐Stoffaustausch, erfordert jedoch die Kompatibilität von Waschmittel und Membranwerkstoff. Es werden die am Lehrstuhl Umwelttechnik vorhandene Versuchsanlage zur kontinuierlichen Membranabsorption und erste Ergebnisse vorgestellt.
Der Einsatz von Mikroreaktoren im chemisch‐technischen Praktikum
Authors: Ondruschka B. , Klemm W. , Scholz P. , Stark A. , Zimmermann EL J. , Strümpel M. , Hegner Dipl. Phys. M.
Published: October 2008

Mikroreaktoren werden in der chemischen Industrie bei der Miniaturisierung verfahrenstechnischer Prozesse bereits seit langem erfolgreich eingesetzt. Forschungsseitig leisteten dazu Hochschulen und Universitäten im Rahmen von Schwerpunktprogrammen einen großen Beitrag. Auf dieser Grundlage und der Auswertung neuester Literatur wurde im Institut für Technische Chemie und Umweltchemie eine Mikroreaktorversuchsapparatur entwickelt und aufgebaut. Ausgehend von den theoretischen Grundlagen lernen die Studierenden am Beispiel eines T‐Mischers den Einfluss der wichtigsten technologischen Parameter auf den Ablauf eines durch den Stofftransport limitierten Reaktionsprozesses kennen. Besonderer Wert wurde dabei auf die Visualisierung und die mathematische Auswertung der Qualität des Mischvorgangs gelegt. Dieses gelang unter Verwendung eines Stereomikroskops, einer handelsüblichen Videokamera und der Anwendung eines dafür angepassten Computerprogramms. Die erzielten Ergebnisse werden dargestellt und ausführlich diskutiert.
Hydrodynamik und Verweilzeitverhalten eines Düsenumlaufreaktors für den Einsatz in der Mehrphasenkatalyse
Authors: Behr A. , Becker M. , Dostal J. , Kohlmann D.
Published: October 2008

Für die effiziente Durchführung von Mehrphasenreaktionen stellen Jetloop‐Reaktoren eine interessante und zunehmend bedeutendere Alternative zu konventionellen Rührkesselreaktoren dar. Die Hydrodynamik wird hierbei durch den Leistungseintrag sowie geometrische Größen der verwendeten Düse und der Einbauten bestimmt. Darüber hinaus ist das Verweilzeit‐ und Mischverhalten für die Durchführung chemischer Reaktionen von besonderer Bedeutung. Die vorliegende Arbeit beschreibt die grundlegenden Untersuchungen zu Hydrodynamik und Verweilzeitverhalten eines Düsenumlaufreaktors, der für die homogene Mehrphasenkatalyse eingesetzt wird.
Dreiphasige Butadien‐Telomerisationen im kontinuierlich betriebenen Schlaufenreaktor
Authors: Behr A. , Dehn D.
Published: October 2008

Homogenkatalysierte, dreiphasige Telomerisationen des Butadiens wurden untersucht. Zunächst wurden einzelne Reaktions‐ und Betriebsparameter im Laborreaktor in halbkontinuierlicher Betriebsweise optimiert und der Einfluss des Stofftransports auf die Reaktionsgeschwindigkeit näher betrachtet. Mit einem neuartigen Schlaufenreaktor wurde anschließend im kontinuierlichen Betrieb gearbeitet. Das Prinzip dieses Reaktors beruht auf einem stetigen Recycling der flüssigen wässrigen Katalysatorphase, in der sich auch das flüssige Edukt befindet, und des nicht umgesetzten gasförmigen Edukts. Ziel war es, ein Reaktorprinzip aufzuzeigen, das sich auf eine Vielzahl von homogenkatalysierten Gas/Flüssig/Flüssig‐Reaktionen anwenden lässt.
Bestimmung von Dampf/Flüssig‐Gleichgewichtsdaten mittels Differenzialkalorimetrie – Experiment und theoretische Validierung
Authors: von Buchholz I. , Schnitzlein K.
Published: October 2008

Vorgestellt wird ein auf der Kopplung von dynamischer Differenzialkalorimetrie und Gasanalytik basierendes Verfahren zur experimentellen Bestimmung von Dampf/Flüssig‐Gleichgewichtsdaten binärer Flüssigkeitsgemische. Die dem Auswertungsalgorithmus zugrunde gelegten Annahmen bezüglich der Verdampfung kleinster Flüssigkeitsmengen wurden durch Modellierung des Experiments erfolgreich validiert. Die Vorteile dieses alternativen Messverfahrens liegen insbesondere in der Kürze des Experiments und der geringen Probenmenge.
Two Photon‐Induced Electron Injection From a Nanotrigger in Native Endothelial NO‐Synthase
Authors: Beaumont Edward , Lambry Jean‐Christophe , Robin Anne‐Claire , Martasek Pavel , Blanchard‐Desce Mireille , Slama‐Schwok Anny
Published: October 2008

We have recently designed a nanotrigger (NT), a photoactive molecule addressing the NADPH sites of proteins. This nanotrigger has a 103 times larger two‐photon cross‐section compared to the ubiquitous NADPH cofactor. In this work, we tested whether two‐photon excitation of the bound NT to NADPH sites may be used to initiate enzymatic catalysis by appropriate electron injection. To establish proof of principle, we monitored the ultrafast absorption of NT bound to the fully active endothelial NO‐Synthase (eNOS) following excitation by one and two‐photons at 405 and 810 nm, respectively. Electron injection from NT* to FAD in eNOS initiated the catalytic cycle in 15±3 ps at both exciting wavelengths. The data proved for the first time that electron transfer can be promoted by two‐photon excitation. We also show that the nanotrigger decays faster in homogeneous solvents than in the NADPH site of proteins, suggesting that hindered environments modified the natural decay of NT. The nanotrigger provides a convenient way of synchronizing an ensemble of proteins in solution with a femtosecond laser pulse. The ability of NT to initiate NOS catalysis by two‐photon excitation may be exploited for controlled and localized release of free NO in cells with enhanced spatial and temporal resolution.
Spectroscopic and Electrochemical Evaluation of Salt Effects on Electron‐Transfer Equilibria between Donor/Acceptor and Ion‐Radical Pairs in Organic Solvents
Authors: Rosokha Sergiy V. , Sun Duoli , Fisher Jeffrey , Kochi Jay K.
Published: October 2008

Addition of “inert” tetrabutylammonium hexafluorophosphate (Bu4NPF6) to a solution of TMDO/DDQ in dichloromethane (where TMDO=2,2,6,6‐tetramethylbenzo[1,2‐d;4,5‐d]bis[1,3]‐dioxole, donor, and DDQ=diclorodicyano‐p‐benzoquinone, acceptor) is accompanied by drastic changes in the electronic spectrum, which are related to the appearance of the DDQ−. and TMDO+. ion radicals and a decrease in the concentration of the neutral molecules and the charge‐transfer complex [TMDO,DDQ]. These changes point to a considerable rise (of about three orders of magnitude) in the apparent electron‐transfer equilibrium constant (KET) for this donor/acceptor pair upon increasing the electrolyte concentration from 0 to 0.5 M. Accordingly, the ion‐radical fractions and KET values are higher in dichloromethane, at high electrolyte concentrations, than in acetonitrile (where the effect of Bu4NPF6 is less pronounced). Similar trends of the apparent equilibrium constants are observed for the tetramethyl‐p‐phenylenediamine/tetracyanoethylene pair. Electron‐transfer equilibrium constants for both donor/acceptor dyads obtained from spectral measurements are related to those derived from the redox potentials of the reactants. The effects of media variations on the electron‐transfer equilibria are discussed within the ion‐pairing and ionic‐activity frameworks.
Are normal and complicated grief different constructs? A confirmatory factor analytic test
Authors: Dillen Let , Fontaine Johnny R. J. , Verhofstadt‐Denève Leni
Published: October 2008

Nowadays, much debate in the bereavement domain is directed towards the inclusion of Complicated Grief (CG) as a separate category in the Diagnostic and Statistical Manual of Mental Disorders. Important within this discussion is the conceptual relationship between CG reactions and normal grief (NG) reactions. This study aims at elucidating this relationship by using data from 456 bereaved young adults, aged 17 to 25 years. We examined the structural distinctiveness of CG and NG reactions, using two criteria sets. The first set ties in with previous research in bereaved adults on the distinctiveness of CG and NG and allows to test the replicability of earlier findings. The second set links up with the recently revised criteria for CG and permits to investigate whether earlier findings hold for the new criteria. For both sets, two models for NG and CG were compared using confirmatory factor analytic procedures. These analyses revealed that CG and NG reactions can be distinguished by their very nature, except for one CG reaction (viz. ‘yearning’), that loaded on both factors. Copyright © 2008 John Wiley & Sons, Ltd.
Attachment and interpersonal distress: examining the relationship between attachment styles and interpersonal problems in a clinical population
Authors: Haggerty Greg , Hilsenroth Mark J. , Vala‐Stewart Rosemarie
Published: October 2008

The present study examined the relationship between self‐perceived attachment styles and interpersonal problems. Specifically, we utilized a clinical sample from an outpatient university‐based community clinic who completed the Experiences in Close Relationships Scale‐Revised, the Relationship Questionnaire and Inventory of Interpersonal Problems Circumplex Scales (IIP‐64) as part of a psychological assessment process. The results showed a significant positive correlation between the IIP‐64 total score and both attachment anxiety and attachment avoidance. Findings revealed significant negative relationships between a secure attachment and the dominant, vindictive, cold, socially inhibited and non‐assertive subscales of the IIP‐64. Findings also revealed a significant positive relationship between a fearful attachment and the dominant, vindictive, cold, socially inhibited and non‐assertive subscales of the IIP‐64. Finally, results showed a significant relationship between a dismissive attachment and the dominant subscale of the IIP‐64. Copyright © 2008 John Wiley & Sons, Ltd.
The Effect of Magnetic Mirror on Near Wall Conductivity in Hall Thrusters
Authors: Yu D. , Liu H. , Cao Y. , Fu H.
Published: October 2008

The effect of magnetic mirror on near wall conductivity is studied in the acceleration region of Hall thrusters. The electron dynamics process in the plasma is described by test particle method, in which electrons are randomly emitted from the centerline towards the inner wall of the channel. It is found that the effective collision coefficient, i.e. the rate of electrons colliding with the wall, changes dramatically with the magnetic mirror effect being considered; and that it decreases further with the increase of magnetic mirror ratio to enhance the electron mobility accordingly. In particular, under anistropic electron velocity distribution conditions, the magnetic mirror effect becomes even more prominent. Furthermore, due to decrease in magnetic mirror ratio from the exhaust plane to the anode in Hall thrusters, the axial gradient of electron mobility with magnetic mirror effect is greater than without it. The magnetic mirror effects on electron mobility are derived analytically and the results are found in agreement with the simulation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spectroscopic Diagnostics of Pulsed arc Plasmas for Particle Generation
Authors: Behringer K. , Höschen T.
Published: October 2008

Pulsed arc plasmas were diagnosed by means of emission spectroscopy. A capacitor was discharged through argon and hydrogen leading to a few cycles of damped current oscillation with ≈120 μs period and 5‐12 kA maximum current. Spectroscopic measurements in the visible range were carried out in order to characterise the electron temperature and density in the arc channel as well as electron and gas temperatures in the afterglow plasmas. Spectra were integrated over 10 μs time windows and shifted in time from pulse to pulse. The plasmas also contained substantial fractions of electrode material (brass), namely copper and zinc. The electron density was measured in the conventional way from the broadening of Hβ or from the Ar I Stark width. In the arc channel, it ranged from about 3 · 1022 to 2 · 1023 m–3. The broadening of Zn II lines could also be used. Ratios of Ar I to Ar II and of Zn I to Zn II line intensities were analysed for the electron temperature. Line pairs were found which lay conveniently close in one frame of the spectrometer allowing automatic on‐line analysis without relying on reproducibility. Atomic physics models including opacity were developed for Ar II and Zn II in order to check the existence of a Boltzmann distribution of their excited states. These calculations showed that the observed levels were in fact close to thermodynamic equilibrium, in particular, if the resonance lines were optically thick. Electron temperature measurements yielded values between 14000 K and 21000 K. The gas temperature in the afterglow, where particles should have formed, was derived from the rotational and vibrational temperatures of C2 molecular bands. Ratios between Cu I line intensities yielded the electron temperatures. Both were found to be a few 1000 K. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)