bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Conformation of New Azo‐functionalized Calix[4]arenes†
Authors: Xing Yan‐Jun , Wang Yan‐Jia
Published: September 2006

A new family of functionalized calix[4]arenes has been synthesized from calix[4]arene or azo‐calix[4]arene by acylation with the correspondingω‐alkylmercapto acid chloride. Six new compounds4a–4cand5a–5cwere isolated and characterised by MALDI, elemental analyses,1H NMR and13C NMR. NMR spectral data showed that these azo‐functionalized calix[4]arenes5a–5care all in 1,3‐alternate conformation in solution at room temperature while calix[4]arenes4a–4care all in cone conformation. The IR and UV properties of calix[4]arenes5a–5cwere also investigated.
N‐Chlorosuccinimide (NCS): A Novel Initiator for Atom Transfer Radical Polymerization of Methyl Methacrylate†
Authors: Wang Xia‐Yan , Chang Li‐Qun , Zhou Hong , Zhang Ke‐Da
Published: September 2006

Atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) was achieved, using N‐chloro‐succinimide (NCS) as an initiator together with catalytic system CuCl/PMDETA (N,N,N′,N′,N′′‐pentamethyldiethyl‐enetriamine), CuCl/MA5‐DETA (N,N,N′,N′,N′′‐penta(methylacrylate)diethylenetriamine), and CuCl/bipy (bipy2,2′‐bipyridyl) respectively. The results indicated that the polymerization possessed typical controlled/living radical polymerization characteristics. The analysis for terminal group of obtained polymer by 1H NMR proved that NCS is an initiator for ATRP. In comparison with NBS, the polymerization rate was slower and the resulted polymer had narrower molecular weight distribution (MWD) when NCS was employed as the initiator.
Difluorocarbene Chemistry: A Simple Transformation of 3,3‐gem‐Difluorocyclopropenes to Cyclopropenones†
Authors: Cheng Zhan‐Ling , Chen Qing‐Yun
Published: September 2006

The cycloaddition reactions of α‐acetyoxyl propynes with difluorocarbene, generated from the decomposition of FSO2CF2CO2SiMe3 in DG in the presence of 10% of NaF at 120 °C gave readily α‐acetyoxyl gem‐difluorocyclopropenes. When these fluorinated compounds were hydrolyzed under alkaline condition at 0 °C, α‐hydroxyl cyclopropenones were produced predominantly whereas treated with catalytic amounts of BF3·Et2O in Et2O, α‐acetyoxyl cyclopropenones were obtained.
Design and Synthesis of Polypyrazolyl Compounds as a New Type of Versatile Building Blocks†
Authors: Li Sheng‐Hui , Huang Hai‐Ping , Yu Shu‐Yan , Li Xian‐Ping
Published: September 2006

The design and synthesis of novel polypyrazolyl aromatic bridging ligands 1,3,5‐tris(3,5‐dimethyl‐1H‐pyra‐ zol‐4‐yl)benzene and 2,4,6‐tris(4‐(3,5‐dimethyl‐1H‐pyrazol‐4‐yl)phenyl)‐1,3,5‐triazine from simple starting materials mesitylene and p‐tolunitrile were reported.
Studies on the Transition Metal Ion Induced Fluorescence Enhancement of 1,8‐Naphthalimide Derivatives†
Authors: Wen Guo‐Tao , Zhu Man‐Zhou , Wang Zhuo , Meng Xiang‐Ming , Hu Hui‐Yuan , Guo Qing‐Xiang
Published: September 2006

Two fluorosensor systems have been designed and synthesized with their photophysical properties and fluorescence responses toward the transition metal ions studied. The fluorosensor was composed of 1,8‐naphthalimide and 4‐chloro‐1,8‐naphthalimide as fluorophore respectively, an amino moiety as the receptor and a hydrocarbon chain as the spacer to link the fluorophore and receptor. Fluorescence intensity of these systems is very weak due to the process of the efficient intramolecular photoinduced electron transfer (PET) in the absence of metal ions. Titration of the transition metal ions can switch on the fluorescence immediately. The intensity of released fluorescence is even higher than the expected from the consideration of the PET in these systems. It may be rationalized that the receptor bound to transition metal ions and the solvation of the fluorophore by the water molecules from the hydrated transition metal salts, may significantly cause fluorescence enhancement.
Stereospecific Synthesis of (Z)‐α‐Fluoro‐β‐trifluoromethyl Vinyl Iodides and Their Application to the Synthesis of Polyfluorinated Thienyl Alkadienes†
Authors: Shen Yan‐Chang , Wang Guo‐Ping
Published: September 2006

The direct iodination of polyfluorinated vinyl stannanes by tin‐iodine exchange methodology was achieved giving(Z)‐α‐fluoro‐β‐trifluoromethyl vinyl iodides stereospecifically. Changing the substituent in R group from the electron‐withdrawing group to electron‐donating group led to an increase in the yield from 78% to 90%, while it was moved from para to meta position the reaction did not afford a dramatic change in the yield (90% to 95%). In addition, this reaction also can be applied to the vinyl stannane with heterocyclic group. The further coupling reaction of prepared vinyl iodide containing heterocyclic moiety with (Z)‐α‐fluoro‐β‐trifluoromethylstannanes gave polyfluorinated heterocyclic alkadienes with 2E,4E‐selectivity.
Correlating Expression Data with Gene Function Using Gene Ontology†
Authors: Liu Qi , Deng Yong , Wang Chuan , Shi Tie‐Liu , Li Yi‐Xue
Published: September 2006

Clustering is perhaps one of the most widely used tools for microarray data analysis. Proposed roles for genes of unknown function are inferred from clusters of genes similarity expressed across many biological conditions. However, whether function annotation by similarity metrics is reliable or not and to what extent the similarity in gene expression patterns is useful for annotation of gene functions, has not been evaluated. This paper made a comprehensive research on the correlation between the similarity of expression data and of gene functions using Gene Ontology. It has been found that although the similarity in expression patterns and the similarity in gene functions are significantly dependent on each other, this association is rather weak. In addition, among the three categories of Gene Ontology, the similarity of expression data is more useful for cellular component annotation than for biological process and molecular function. The results presented are interesting for the gene functions prediction research area.
Indium Trichloride‐Mediated Facile Synthesis of 3‐(Substituted methylthio)‐4‐phenyl‐5‐(3,4,5‐trimethoxyphenyl)‐4H‐1,2,4‐triazole in Water†
Authors: Yang Song , Song Bao‐An , Jin Lin‐Hong , Hu De‐Yu
Published: September 2006

An environmentally benign and efficient process for the preparation of 3‐(substituted methylthio)‐4‐phenyl‐5‐ (3,4,5‐trimethoxyphenyl)‐4H‐1,2,4‐triazole was achieved by the reaction of 4‐phenyl‐5‐(3,4,5‐trimethoxyphenyl)‐ 4H‐1,2,4‐triazole‐3‐thiol with different halides in aqueous media mediated by indium trichloride in high yields.
Plasma interleukin‐6 levels are increased in subjects with impaired glucose tolerance but not in those with impaired fasting glucose in a cohort of Italian Caucasians
Authors: Cardellini Marina , Andreozzi Francesco , Laratta Emanuela , Marini Maria Adelaide , Lauro Renato , Hribal Marta Letizia , Perticone Francesco , Sesti Giorgio
Published: September 2006

Background

While the relationship between impaired glucose tolerance (IGT) and circulating interleukin‐6 (IL‐6) is well established, there is no information whether IL‐6 levels are elevated in impaired fasting glucose (IFG).

Methods

To this end, we examined the relationship between plasma IL‐6 concentration and different degrees of glucose homeostasis in a cohort of 470 Italian Caucasian subjects comprising 236 normal glucose tolerant (NGT), 49 IFG, 51 IGT, and 134 type 2 diabetic subjects.

Results

We observed that IL‐6, CRP and fibrinogen levels were higher in subjects with IGT or type 2 diabetes as compared with NGT and IFG subjects. Univariate correlations between IL‐6 concentrations and metabolic variables in the whole cohort showed that IL‐6 levels were positively correlated with age, BMI, waist, systolic and diastolic blood pressure, fasting plasma glucose, triglycerides, CRP, fibrinogen, and negatively correlated with insulin sensitivity, IGF‐I and HDL. In a subgroup analysis including NGT, IFG and IGT (n = 336), IL‐6 levels were positively correlated with age, BMI, waist, systolic and diastolic blood pressure, triglycerides, CRP, fibrinogen, fasting insulin, 2 h post‐load glucose, and negatively correlated with insulin sensitivity, IGF‐I and HDL. Stepwise linear regression analysis in a model including gender, age, BMI, waist, glucose tolerance status, fasting plasma glucose, 2 h post‐load glucose, triglycerides, HDL, fasting insulin, and insulin sensitivity revealed that waist was the only independent variable associated with IL‐6 levels accounting for 21.0% of its variation (P < 0.0001).

Conclusions

These data show that IGT and type 2 diabetes, but not IFG, are associated with elevated plasma IL‐6 levels. Copyright © 2006 John Wiley & Sons, Ltd.
Gliclazide protects human islet beta‐cells from apoptosis induced by intermittent high glucose
Authors: Del Guerra S , Grupillo M , Masini M , Lupi R , Bugliani M , Torri S , Boggi U , Del Chiaro M , Vistoli F , Mosca F , Del Prato S , Marchetti P
Published: September 2006

Background

Decreased beta‐cell mass, mainly due to apoptosis, is crucial for the development and progression of type 2 diabetes. Chronic exposure to high glucose levels is a probable underlying mechanism, whereas the role of oral anti‐diabetic agents (sulphonylureas in particular) is still unsettled.

Methods

To directly investigate more on such issues, we prepared isolated human islets, which were then cultured for 5 days in continuous normal glucose concentration (NG, 5.5 mmol/L) or normal and high (HG, 16.7 mmol/L) glucose levels (alternating every 24 h), with or without the addition of therapeutical concentration (10 µmolL) of gliclazide or glibenclamide.

Results

Intermittent high glucose caused a significant decrease of glucose‐stimulated insulin secretion, which was not further affected by either sulphonylurea. Apoptosis, as assessed by electron microscopy, was also significantly increased by alternating high glucose exposure, which was accompanied by altered mitochondria morphology and density volume, and increased concentrations of nitrotyrosine, a marker of oxidative stress. Gliclazide, but not glibenclamide, was able to significantly reduce high glucose induced apoptosis, mitochondrial alterations, and nitrotyrosine concentration increase.

Conclusion

Therefore, gliclazide protected human beta‐cells from apoptosis induced by intermittent high glucose, and this effect was likely to be due, at least in part, to the anti‐oxidant properties of the molecule. Copyright © 2006 John Wiley & Sons, Ltd.
Metformin prolongs the postprandial fall in plasma ghrelin concentrations in type 2 diabetes
Authors: English P. J. , Ashcroft A. , Patterson M. , Dovey T. M. , Halford J. C. G. , Harrison J. , Eccleston D. , Bloom S. R. , Ghatei M. A. , Wilding J. P. H.
Published: September 2006

Background

Weight loss is difficult to achieve in type 2 diabetes and many therapies are associated with weight gain, an effect attenuated by metformin. We studied the effects of metformin on energy expenditure, appetite and the regulation of PYY and ghrelin in type 2 diabetes.

Methods

Plasma peptide YY (PYY), ghrelin, resting metabolic rate (RMR), postprandial thermogenesis (PPTG), and appetite ratings were measured at baseline and following a mixed meal in 11 type 2 diabetic subjects treated with diet alone (T2D) and 10 treated with metformin monotherapy (T2MF). The groups were similar in age, gender and adiposity.

Results

There were no differences in baseline anthropometric, or metabolic variables between the groups. Postprandially, plasma ghrelin fell equally in both groups (23% versus 24.5%, p < 0.05 versus baseline, p = NS between groups) but were reduced for longer in T2MF (below baseline 60–240 min T2MF versus 60–180 min T2D) coincidentally with a prolonged sensation of fullness and suppression of hunger in the metformin‐treated group. There were no differences in PYY concentrations, RMR or PPTG.

Conclusions

Metformin prolongs the postprandial fall in ghrelin concentrations. These effects may prolong the inter‐meal interval, thereby decreasing snack intake and daily energy intake, promoting weight loss. Copyright © 2006 John Wiley & Sons, Ltd.
Chiral 1,10‐Phenanthroline‐Bridged Calix[6]arenes
Authors: Konrad Serge , Bolte Michael , Näther Christian , Lüning Ulrich
Published: September 2006

Several approaches to chiral derivatives of the 1,10‐phenanthroline‐bridged calix[6]arene 3 have been investigated, and seven new chiral calix[6]arenes have been synthesized. The C2‐symmetric axially chiral bimacrocycle 5 has been synthesized as racemic mixture; calixarenes 8, 14, 18, 19, 20 and 21 carrying chiral substituents (camphorsulfonyl, myrtanyl) have been prepared using enantiomerically pure reagents. Three chiral bimacrocycles 5, 19 and 20 have also been analyzed by X‐ray analyses. All compounds have been tested as ligands for copper ions in the CuI‐catalyzed cyclopropanation of styrene and indene.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Long Chain‐Substituted and Triply Functionalized Molecular Knots – Synthesis, Topological Chirality and Monolayer Formation
Authors: Böhmer Athanasia , Brüggemann Jens , Kaufmann Astrid , Yoneva Albena , Müller Sonja , Müller Walter M. , Müller Ute , Vergeer Frank W. , Chi Lifeng , De Cola Luisa , Fuchs Harald , Chen Xiaoming , Kubota Takateru , Okamoto Yoshio , Vögtle Fritz
Published: September 2006

New topological chiral molecular knots (knotanes) 3a–6 of the amide type were substituted with long aliphatic side chains (butyloxy, hexyloxy, octenyloxy, decyloxy) and with p‐bromobenzyloxy and oligoethylene glycol ether units, which resulted in improved solubility and enhanced potential for racemate separation. In consequence, the knotanes with longer substituted chains could be separated even on commercially available noncovalently bound chiral stationary phases. The (p‐bromobenzyloxy)‐knotane 6 and the octenyloxy‐knotane 4 were synthesized with the intention of using their functional sidechains in further reactions, 6 being used in Suzuki‐type reactions, while 4 was consequently allowed to react in the presence of Grubbs catalyst in metathesis reactions. The achieved solubility allowed us to test the abilities of the alkyl chain‐substituted knotanes 3a–c and the (p‐bromobenzyloxy)‐knotane 6 to form Langmuir–Blodgett films. The assemblies were investigated on mica by AFM technique. A key point of focus was the (topological) chirality of the long chain‐substituted knotanes. To address this point, the racemates were enantioseparated by HPLC on various chiral phases, and the obtained pure enantiomers were found to exhibit pronounced Cotton effects in their circular dichroism spectra. The absolute configurations of all new knots were derived by comparison with the unsubstituted knot. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
The Stereochemical Course of the Generation and Interception of aSix‐Membered Cyclic Allene: 3δ2‐1H‐Naphthalene (2,3‐Didehydro‐1,2‐dihydronaphthalene)
Authors: Christl Manfred , Braun Martin , Fischer Hartmut , Groetsch Stefan , Müller Germar , Leusser Dirk , Deuerlein Stephan , Stalke Dietmar , Arnone Mario , Engels Bernd
Published: September 2006

The bromofluorocarbene adduct rac‐1 of indene, possessing the fluorine atom at the endo position, is a useful substrate for the generation of the isonaphthalene 4 by the Doering–Moore–Skattebøl reaction. By resolution of rac‐1, an enantiomerically pure precursor of a six‐membered cyclic allene was obtained for the first time. The treatment of (+)‐ or (–)‐1, dissolved in 2,5‐dimethyl‐, 2‐tert‐butyl‐5‐methyl‐, or 2,5‐bis(tert‐butyl)furan, with methyllithium gave rise to the [4+2] cycloadducts 6 of 4 to the furans. It was shown by means of HPLC on Chiralcel OD that the formation of 6 proceeded with about 40 % ee, and that this value was independent of the type and concentration of the furan, and the reaction temperature. The absolute configurations of the enantiomers 1, as well as those of the enantiomers 6, were determined by simulation of the CD spectra by quantum chemical methods and by the comparison of them with the experimental spectra. In the case of (+)‐1, the reliability of this procedure was checked by X‐ray crystal structure analysis. On the basis of these results, a model is proposed for the steric course of the reaction sequence, leading from a pure enantiomer 1 to the 70:30 mixtures of the product enantiomers 6. The use of indene as trapping reagent for 4 furnished the [2+2] cycloadduct 15. For the preparation of rac‐15, the particularly simple one‐pot procedure was employed, in which indene, tetrabromomethane, and methyllithium were combined and in which the dibromocarbene adduct 2 of indene serves as precursor of 4. Compound 2 could not be isolated, but was characterised by low‐temperature 1H NMR spectra. The conversion of (+)‐ or (–)‐1 into 4 in the presence of indene afforded 15 only with a very low enantioselectivity. The constitutions and the relative configurations of 15 as well as the compounds 8 and 16, which resulted from thermolysis of the cycloadducts 6b and 15, respectively, were elucidated by X‐ray crystal diffraction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
C2‐Chiral Substituted cis‐1,3,5,7‐Tetraazadecalins as Proton Sponges:A Computational Study
Authors: Singh Ajeet , Chakraborty Shampa , Ganguly Bishwajit
Published: September 2006

Density functional quantum chemical calculations at the B3LYP/6‐31+G* and B3LYP/6‐31+G** levels have been performed to calculate the proton affinities of chiral cis‐1,5‐diazadecalins 1,2 and substituted cis‐1,3,5,7‐tetraazadecalin 3. The calculated gas‐phase proton affinities of cis‐1,3,5,7‐tetraazadecalins are higher than that of 1,8‐bis(dimethylamino)naphthalene (4). cis‐1,5‐Diazadecalins show lower proton affinities compared with those of substituted 1,3,5,7‐tetraazadecalins. Cooperative and anomeric effects seem to be responsible for the additional stabilization of the protonated forms of 1,3,5,7‐tetraazadecalins. Intramolecular proton transfer energies have been predicted for these amines and discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Dimethoxycarbene: Conformational Analysis of a Reactive Intermediate
Authors: Reisenauer Hans Peter , Romanski Jaroslaw , Mloston Grzegorz , Schreiner Peter R.
Published: September 2006

Dimethoxycarbene was prepared from an oxadiazoline precursor under high‐vacuum flash pyrolysis (HVFP) conditions and was trapped at low temperatures by matrix isolation techniques (Ar, 10 K). The excellent agreement between the computed [CCSD(T)/cc‐pVDZ] IR spectrum of the mixture of conformers of dimethoxycarbene and the experimentally measured IR absorptions allows a detailed analysis ofthe conformational preference of dimethoxycarbene. ItsUV spectrum is in agreement with earlier studies and ourTD‐B3LYP/6‐311+G(d,p) computations. The computed [CCSD(T)/cc‐pVDZ] rotational profile is rather steep and separates the s‐trans,s‐trans and s‐cis,s‐trans conformers by a 16 kcal mol–1 barrier, whilst the s‐cis,s‐cis conformer is too high‐lying to be observable (+17 kcal mol–1). In marked contrast with the gauche,gauche minimum of dimethoxymethane, the s‐trans,s‐trans conformer of dimethoxycarbene is slightly preferred (0.5 kcal mol–1). The s‐cis,s‐trans conformer equilibrates at the high temperatures required during HFVP generation and both conformers can be identified in the IR spectrum of the argon matrix at 10 K. The conformational preference is partly due to the minimization of the overall dipole moment in the s‐trans,s‐trans conformer. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Synthesis and Conformational Analysis of C‐4′‐Modified (2‐Oxabicyclo[3.1.0]hexyl)pyrimidine Nucleosides
Authors: Gagneron Julien , Gosselin Gilles , Mathé Christophe
Published: September 2006

We report on the synthesis of hitherto unknown pyrimidine nucleoside analogues bearing the 2‐oxabicyclo[3.1.0]hexane scaffold (5, 6, 8, 13–17 and 19) with various modifications at the C‐4′ position including methylene, azido, and arabino‐like configuration. Conformational analysis on the nucleoside analogues 6, 14 and 17 indicates that the conformation of such C‐4′‐modified nucleoside analogues was restricted in the South‐East hemisphere of the pseudorotation cycle (between a 0T1 and a 2E conformation). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Study of the Substituent‐Influenced Anomeric Effect in the Ring‐Chain Tautomerism of 1‐Alkyl‐3‐aryl‐naphth[1,2‐e][1,3]oxazines
Authors: Szatmári István , Tóth Diána , Koch Andreas , Heydenreich Matthias , Kleinpeter Erich , Fülöp Ferenc
Published: September 2006

The stabilities of the trans (B) and cis (C) tautomeric ring forms that are experimentally observed in the ring‐chain tautomeric interconversion of 1‐alkyl‐3‐aryl‐2,3‐dihydro‐1H‐naphth[1,2‐e][1,3]oxazines has been investigated. Stability differences are explained by the analysis of the natural bond orbital results for the lone pairs of electrons that are on the heteroatoms in the oxazine ring system and by regression analysis of the calculated 13C NMR chemical shift values. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Genotyping of simple sequence repeat factors implicated in shadow band generation revisited
Authors: Olejniczak Marta , Krzyzosiak Wlodzimierz J.
Published: September 2006

PCR amplification of microsatellite sequences generates, besides the main product corresponding to allele size, also additional, undesired products usually shorter by multiples of the repeated unit. These extra products known as shadow bands or stutter products may complicate genotyping. The mechanism by which these artifacts are formed is not well understood and so no effective remedy has been found to cope with these spurious products. In this study, using the DNA templates containing the CAG/CTG repeats flanked by gene‐specific sequences and universal priming sites, we analyzed the effects of many PCR variables on the shadow band generation. The most important result was that at the decreased temperature of the denaturation step during PCR cycling the shadow bands were either not formed or were strongly suppressed. Several possible sources of this effect are discussed.
Factors associated with treatment seeking in a community sample of European American and Mexican American women with eating disorders
Authors: Cachelin Fary M. , Striegel‐Moore Ruth H. , Regan Pamela C.
Published: September 2006

The purpose of this study was to investigate factors associated with treatment seeking in a community sample of European American and Mexican American women with eating disorders. We also explored which variables were associated with receiving treatment. Participants were 190 women with eating disorders (80 Mexican American, 110 European American) who were diagnosed using the SCID‐IV and Eating Disorder Examination. Results indicated that treatment seeking is associated with ethnicity (i.e. being European American), suffering from bulimia nervosa and more frequent purging, longer duration of disorder and psychiatric comorbidity and, for Mexican American women, higher degree of acculturation. Detection and treatment of eating disorder was associated with ethnicity (European American), earlier age of onset and lower BMI. Given the debilitating and chronic nature of eating disorders, further knowledge of factors that impede or facilitate help seeking and detection and treatment is needed. Copyright © 2006 John Wiley & Sons, Ltd and Eating Disorders Association.
Diving Underwater With Sea Turtles
Authors: Storch Sandra
Published: September 2006

Hawksbill turtles live on inaccessible islands in tropical oceans. In order to gain insight on their diving behaviour and their marine way of life some have been equipped with modern “trip recorders”
Behind the Façade of Saint Mark's
Authors: Schuller Manfred , Uetz Karin
Published: September 2006

Tracing the history of Saint Mark's Basilica in Venice: Historians have carried out painstaking research into the changes made to this elaborate building through the centuries.
No Snow on Kilimanjaro?
Authors: Hemp Andreas
Published: September 2006

Africa's highest mountain rises majestically above the savannah. Its slopes offer a variety of habitats to fascinating flora. But the entire ecosystem is threatened
Does the economy affect teenage substance use?
Authors: Arkes Jeremy
Published: September 2006

This research examines how teenage drug and alcohol use responds to changes in the economy. In contrast to the recent literature confirming pro‐cyclical alcohol use among adults, this research offers strong evidence that a weaker economy leads to greater teenage marijuana and hard‐drug use and some evidence that a weaker economy also leads to higher teenage alcohol use. The findings are based on logistic models with state and year fixed effects, using teenagers from the NLSY‐1997. The evidence also indicates that teenagers are more likely to sell drugs in weaker economies. This suggests one mechanism for counter‐cyclical drug use – that access to illicit drugs is easier when the economy is weaker. These results also suggest that the strengthening economy in the 1990s mitigated what would otherwise have been much larger increases in teenage drug use. Copyright © 2006 John Wiley & Sons, Ltd.
Cognitive testing in early phase clinical trials: outcome according to adverse event profile in a Phase I study
Authors: Collie Alex , Maruff Paul , Snyder Peter J. , Darekar Miss Amanda , Huggins John P.
Published: September 2006

Background

It has been proposed that objective cognitive testing provides additional information to that collected via adverse event (AE) recordings. However, in clinical trials of compounds with potentially negative effects on cognition, the results of cognitive testing may overlap with AE recordings.

Aims

To examine cognitive function in subjects who do and do not report sedation‐related AEs in a Phase I clinical trial.

Methods

Five computerized cognitive tasks were administered to 28 healthy male volunteers enrolled in a simulated Phase I study using midazolam to induce sedation‐related AEs and cognitive dysfunction. For each subject, the magnitude of cognitive change between pre‐dose and 1 hr post‐dose assessments was calculated. Group and individual level cognitive outcome was compared between subjects who did and did not report sedation‐related AEs following administration of 1.75 and 5.25 mg midazolam.

Results

At both doses of midazolam, cognitive dysfunction was observed in both subject groups (i.e., those who did and did not report AEs). Analysis of individual outcomes identified consistent cognitive dysfunction among subjects who reported sedation‐related AEs. Further, in the 5.25 mg condition a subset of individuals (66.7%) who did not report sedation‐related AEs nevertheless displayed substantial cognitive dysfunction.

Conclusions

Following administration of oral midazolam, there is a dissociation between sedation‐related AE recordings and performance on computerized cognitive tests of motor function, attention, strategy use and problem solving, learning and delayed recall. Inclusion of computerized cognitive tests in early phase trials may allow identification of subtle cognitive change, beyond that which is possible by self‐report and clinical observation. Copyright © 2006 John Wiley & Sons, Ltd.
Long‐term trend of precipitation in China and its association with the El Niño–southern oscillation
Authors: Xu Z. X. , Li J. Y. , Takeuchi K. , Ishidaira H.
Published: September 2006

The plausible long‐term trend of precipitation in China and its association with El Niño–southern oscillation (ENSO) are investigated by using non‐parametric techniques. It is concluded that a greater number of decreasing trends are observed than are expected to occur by chance. Geographically, the decreasing trend was concentrated in most parts of China, including the Songliao River, Hai River, Huai River, Yellow River, Zhujiang River, and southern part of the Yangtze River basins, whereas an increasing trend appeared primarily in the western and middle parts of China, mainly including the Inland River basin, and the northern part of the Yangtze River basins. Monthly mean precipitation for the summer and early autumn months generally decreased, with the greatest decrease occurring in August. The precipitation in spring from January to April and later autumn, including September and October, tended to increase. The teleconnection between precipitation and ENSO has been investigated by using the non‐parametric Kendall's τ. The correlation coefficients between the southern oscillation index (SOI) and precipitation show the areas with positive or negative associations. Approximately 20% of the stations exhibit statistically significant correlations between SOI and precipitation, of which 70% show a negative correlation, with most of them appearing in southeast China and several appearing in northwest and northeast China. Similar regional patterns are also observed when the precipitation records are further subdivided into El Niño, La Niña, and neutral periods. Statistical tests for the three kinds of time series were carried out using the non‐parametric Wilcoxon rank‐sum test, and it is noted that the stations with significant differences in precipitation averages are mainly marked in the Yellow River basin and south China. The frequencies of below‐ and above‐average precipitation that occurred during the El Niño, La Niña, and neutral periods are estimated as well. The result shows that greater precipitation may be associated with El Niño episodes in south China, but drought may easily occur during El Niño episodes in the Yellow River basin. Copyright © 2006 John Wiley & Sons, Ltd.
Comparative streamflow characteristics in urbanizing basins in the Portland Metropolitan Area, Oregon, USA
Authors: Chang Heejun
Published: September 2006

This study investigates changes in streamflow characteristics for urbanizing watersheds in the Portland Metropolitan Area of Oregon for the period from 1951 to 2000. The objective of this study was to assess how mean annual runoff ratio, mean seasonal runoff ratio, annual peak runoff ratio, changes in streamflow in response to storm amount, the fraction of time that the daily mean flow exceeds the annual mean flow, 3‐day recession constants, and dry/wet flow ratio vary among watersheds with different degrees of urban development. There were no statistically significant changes in annual runoff ratio and annual peak runoff ratio for the mixed land‐use watershed (Tualatin River watershed) and the urban watershed (Johnson Creek watershed) during the entire study period. The Tualatin River watershed, where most of the urban development occurred in a lower part of the watershed, showed a statistically significant increase in annual peak runoff ratio during the 1976 and 2000 period. The Upper Tualatin River watershed illustrated a significant decrease in annual peak runoff ratio for the entire study period. With significant differences in seasonal runoff ratio, only Johnson Creek exhibited a significant increase in both wet and dry season runoff ratios. Streamflow during storm events declined rapidly in the urban watershed, with a high 3‐day recession constant. At an event storm scale, streamflow in Fanno Creek, which is the most urbanized watershed, responded quickly to precipitation input. The fraction of time that the daily mean flow exceeded the annual mean flow and dry/wet flow ratio are all lower in Johnson Creek. This suggests a shorter duration of storm runoff and lower baseflow in the urbanized watershed when compared to the mixed land use watershed. The findings of this study demonstrate the importance of spatial and temporal scale, climate variability, and basin physiographic characteristics in detecting the hydrologic effects of urbanization in the Pacific Northwest of the USA. Copyright © 2006 John Wiley & Sons, Ltd.
Use of turbidometry to characterize suspended sediment and phosphorus fluxes in the Lake Tahoe basin, California, USA
Authors: Stubblefield Andrew P. , Reuter John E. , Dahlgren Randy A. , Goldman Charles R.
Published: September 2006

The efficacy of in‐stream nephelometric turbidometry as a surrogate for total suspended solids (TSS) and total phosphorus (TP) concentrations was evaluated for use in low turbidity (<50 NTU) subalpine watersheds at Lake Tahoe, California–Nevada, USA. Continuous turbidity records for the 1999, 2000 and 2001 snowmelt seasons and data from water quality samples (1982–2000) were examined to determine watershed sediment delivery dynamics. Strong correlations were found between turbidity and both TSS and TP concentration. The strong correlation indicates that turbidity can serve as a good surrogate for direct measurement in these watersheds. The watersheds displayed clockwise hysteresis: sediment flushing and depletion, on daily, seasonal and decadal time‐scales. The hysteresis curves had strong concave shapes, indicating a sensitive response to peak flow. A pronounced seasonal trend was observed for the ratio of suspended sediment concentration (SSC)/discharge over time, indicating early season flushing of available sediment. Significant linear relationships (p < 0·05) were found for 12 of 17 years. Comparison of annual sediment rating curve coefficients indicated smaller coefficients during high sediment loading years and in the years following. The smaller coefficients are evidence of sediment depletion during high flow years. The effect of hysteresis on monitoring methods was illustrated by comparing turbidity estimates of TSS load with sediment rating curve estimates of SSC. After accounting for differences in SSC/TSS methods of analysis, daily loads calculated with turbidity methods were 58–98% of rating curve estimates for the spring snowmelt seasons of 1999–2001. Copyright © 2006 John Wiley & Sons, Ltd.
Numerical simulation of a dam break for an actual river terrain environment
Authors: Liao C. B. , Wu M. S. , Liang S. J.
Published: September 2006

A two‐dimensional (2D) finite‐difference shallow water model based on a second‐order hybrid type of total variation diminishing (TVD) approximate solver with a MUSCL limiter function was developed to model flooding and inundation problems where the evolution of the drying and wetting interface is numerically challenging. Both a minimum positive depth (MPD) scheme and a non‐MPD scheme were employed to handle the advancement of drying and wetting fronts. We used several model problems to verify the model, including a dam break in a slope channel, a dam break flooding over a triangular obstacle, an idealized circular dam‐break, and a tide flow over a mound. Computed results agreed well with the experiment data and other numerical results available. The model was then applied to simulate the dam breaking and flooding of Hsindien Creek, Taiwan, with the detailed river basin topography. Computed flooding scenarios show reasonable flow characteristics. Though the average speed of flooding is 6–7 m s−1, which corresponds to the subcritical flow condition (Fr < 1), the local maximum speed of flooding is 14·12 m s−1, which corresponds to the supercritical flow condition (Fr ≈ 1·31). It is necessary to conduct some kind of comparison of the numerical results with measurements/experiments in further studies. Nevertheless, the model exhibits its capability to capture the essential features of dam‐break flows with drying and wetting fronts. It also exhibits the potential to provide the basis for computationally efficient flood routing and warning information. Copyright © 2006 John Wiley & Sons, Ltd.
Determination of the unit hydrograph of a typical urban basin using genetic programming and artificial neural networks
Authors: Rabuñal J. R. , Puertas J. , Suárez J. , Rivero D.
Published: September 2006

An application of genetic programming (GP) and artificial neural networks (ANNs) in hydrology is proposed, showing how these two techniques can work together to solve the problem of modelling the effect of rain on the runoff flow in a typical urban basin. The ability of GP to include the physical basis of a problem and even to analyse the results is discussed, and a case study is included as an example. We propose a solution to this problem by using an ANN for the prediction of the daily flow due to human activity of the citizens and the use of GP for the prediction of the flow rate resulting from the rain. Finally, it is shown that the methodology can be used to solve similar problems by combining both techniques. Copyright © 2006 John Wiley & Sons, Ltd.
Hydrograph and unit hydrograph derivation in arid regions
Authors: Şen Zekai
Published: September 2006

Arid and semi‐arid regions expose special hydrological features that are distinctive from humid areas. Unfortunately, humid‐region hydrological empirical formulations are used directly in the arid and semi‐arid regions without care about the basic assumptions. During any storm rainfall in arid regions, rainfall, infiltration and runoff components of the hydrological cycle have impacts on water resources. The basis of the methodology presented in this paper is the ratio of runoff increment to rainfall increment during an infinitesimally small time duration. This is the definition of runoff coefficient for the same infinitesimal time duration. The ratio is obtained through rational, physical and mathematical combination of hydrological thinking and then integrated with the classical infiltration equation for the hydrograph determination. The parameters of the methodology are explained and their empirical estimations are presented. The methodology works for rainfall and runoff from ungauged watersheds where infiltration measurement can be performed. The comparison of the new approach with different classical approaches, such as the rational formula and Soil Conservation Service method, are presented in detail. Its application is performed for two wadis within the Kingdom of Saudi Arabia. Copyright © 2006 John Wiley & Sons, Ltd.
Electrical earth resistivity surveying for delineating the characteristics of ground water in a semi‐arid region in the Khanasser Valley, northern Syria
Authors: Asfahani Jamal
Published: September 2006

A resistivity survey is conducted in Khanasser Valley, a semi‐arid region in northern Syria, to delineate the characteristics of ground water affected by the salt‐water intrusion related to Al‐Jaboul Sabkha. Existing wells were used to measure salinity and conductivity of water samplings. Vertical electrical sounding was carried out near the existing wells. The combination of resistivity and hydrogeological data enables the establishment of empirical relationships between earth resistivity, water resistivity, and the amount of total dissolved solids. These relationships are then used in order to derive salinity maps for electrode spacings of 70, 100, and 150 m. The distribution of fresh, brackish and salt‐water zones and their variations in space along two longitudinal profiles (LP1 and LP2) are established through converting subsurface depth–resistivity models into different ground‐water areas. The constructed ground‐water area maps allow interfaces between different water zones to be determined. Copyright © 2006 John Wiley & Sons, Ltd.
In vitro and in vivo differentiation of human umbilical cord derived stem cells into endothelial cells
Authors: Wu Kai Hong , Zhou Bin , Lu Shi Hong , Feng Bin , Yang Shao Guang , Du Wei Ting , Gu Dong Sheng , Han Zhong Chao , Liu Ying Long
Published: September 2006

The successful use of tissue‐engineered transplants is hampered by the need for vascularization. Recent advances have made possible the using of stem cells as cell sources for therapeutic angiogenesis, including the vascularization of engineered tissue grafts. The goal of this study was to examine the endothelial potential of human umbilical cord‐derived stem (UCDS) cells. UCDS cells were initially characterized and differentiated in an endothelial differentiation medium containing VEGF and bFGF. Differentiation into endothelial cells was determined by acetylated low‐density lipoprotein incorporation and expression of endothelial‐specific proteins, such as PECAM and CD34. In vivo, the transplanted UCDS cells were sprouting from local injection and differentiated into endothelial cells in a hindlimb ischemia mouse model. These findings indicate the presence of a cell population within the human umbilical cord that exhibits characteristics of endothelial progenitor cells. Therefore, human umbilical cord might represent a source of stem cells useful for therapeutic angiogenesis and re‐endothelialization of engineered tissue grafts. J. Cell. Biochem. 100: 608–616, 2007. © 2006 Wiley‐Liss, Inc.
Adenovirus efficiently transduces plasmacytoid dendritic cells resulting in TLR9‐dependent maturation and IFN‐α production
Authors: Basner‐Tschakarjan Etiena , Gaffal Evelyn , O'Keeffe Meredith , Tormo Damia , Limmer Andreas , Wagner Hermann , Hochrein Hubertus , Tüting Thomas
Published: September 2006

Background

Recombinant replication‐deficient adenoviral vectors (recAd) are attractive candidates for DNA vaccination approaches because they are able to activate the innate and adaptive immune systems. Here we explore the ability of recAd to transduce and activate subsets of dendritic cells, namely plasmacytoid dendritic cells (pDC) and conventional dendritic cells (cDC).

Methods

DC were derived from bone marrow precursors in vitro with the help of FLT3‐ligand. Sorted populations of pDC and cDC were infected with recAd at various multiplicities of infection. Transduction efficiency, phenotypic maturation and production of IFN‐α as well as IL‐6 were assessed. Additionally, activation of DC and induction of cytotoxic T lymphocytes (CTL) were determined in vivo. The role of Toll‐like receptor (TLR) 9 in recAd recognition was investigated as it has previously been shown that DNA viruses are recognized via this receptor.

Results

RecAd can efficiently transduce pDC as well as cDC in vitro. Both DC subsets mature and produce IFN‐α upon interaction with recAd. In the absence of TLR9, activation and cytokine production was only detected in cDC but not in pDC. Importantly, induction of CD8+ CTL following in vivo injection of recAd was similar in TRL9‐deficient mice when compared with wildtype controls.

Conclusions

RecAd can efficiently transduce and activate both pDC and cDC. pDC required TLR9 to detect the presence of recAd whereas cDC also recognized recAd independently of TLR9. These unique immunostimulatory properties support the future development of recombinant Ad as a vector for DNA vaccine approaches. Copyright © 2006 John Wiley & Sons, Ltd.
Highly efficient preparation of carbon‐14 labeled, auxin herbicide 4‐amino‐3,5,6‐trichloropicolinic acid
Authors: Pearson Norman R. , Lardie Tom S.
Published: September 2006

A highly efficient, seven‐step route has been developed for the preparation of 2,6‐[14C2]‐4‐amino‐3,5,6‐trichloropicolinic acid ([14C2]‐1, 2,6‐[14C2]‐picloram) from 2,6‐[14C2]‐pentachloropyridine. The method involves the stepwise, highly selective and high yield introduction of amino and carboxylic acid groups to the 4‐ and 2‐positions, respectively, of pentachloropyridine affording [14C2]‐1 in an overall radiochemical yield of >70% with the use of only one formal purification step. Copyright © 2006 John Wiley & Sons, Ltd.
Bioavailability of 99mTc‐Ha‐paclitaxel complex [99mTc‐ONCOFID‐P] in mice using four different administration routes
Authors: Meléndez‐Alafort Laura , Riondato Mattia , Nadali Anna , Banzato Alessandra , Camporese Davide , Boccaccio Pasquale , Uzunov Nikolay , Rosato Antonio , Mazzi Ulderico
Published: September 2006

Paclitaxel, an anti‐tumour drug, shows good results against breast and ovarian cancer. However, its therapeutic response is associated with toxic side‐effects caused by the agent used to dissolve it. Recently paclitaxel was linked to the linear polysaccharide hyaluronic acid (HA), showing good solubility, stabilization, localization and a reduction of cytotoxic side‐effects.

To study potential therapeutic applications, HA‐paclitaxel bioconjugate (ONCOFID‐P) was labelled with 99mTc by the addition of 99mTc‐pertechnetate, SnCl2 and sodium gluconate. The reaction mixture was incubated for 90 min at 65°C and purified by size exclusion chromatography. The obtained 99mTc‐ONCOFID‐P had 100% radiochemical purity and was stable in a phosphate buffer dilution 1:100 for 6 h at 37°C. 99mTc‐ONCOFID‐P bioavailability studies were carried out in healthy mice using four different administration pathways. The analysis showed that after intravenous administration more than 80% of the injected radiopharmaceutical was found in liver and spleen. Intraperitoneal, intravesical and oral administrations showed that all the 99mTc‐ONCOFID‐P remained at the administration site.

These results demonstrate that ONCOFID‐P administered intravenously could be used for liver metastasis therapy due to its high physiological and receptor‐specific liver uptake, while intravesical, intraperitoneal and oral administration of ONCOFID‐P could be used for local treatment of superficial cancers. Copyright © 2006 John Wiley & Sons, Ltd.
A simple and efficient synthesis of [3α‐3H]5α‐androst‐16‐en‐3β‐ol
Authors: Ren S. , Hesk D. , McNamara P. , Koharski D.
Published: September 2006

An efficient one step synthesis of [3α‐3H]5α‐androst‐16‐en‐3β‐ol by NaBT4 reduction of a ketone precursor is described. The specific activity of the product was 21.6 Ci/mmol with a radiochemical purity >99%. Synthesis of the precursor, 5α‐androst‐16‐en‐3‐one, from commercially available 5α‐androst‐16‐en‐3α‐ol is also presented. Copyright © 2006 John Wiley & Sons, Ltd.
Prediction of frozen storage time of Cape hake (Merluccius capensis and Merluccius paradoxus) by instrumental methods
Authors: Herrero Ana M , Careche Mercedes
Published: September 2006

An instrumental method to predict frozen storage time of Cape hake was developed by evaluation of a combination of methods previously known to classify hake into different quality categories, such as apparent viscosity, Kramer and puncture tests. The results showed that with multiple linear regression analysis it was possible to obtain linear models for the prediction of storage time at − 20°C. Only apparent viscosity (ηapp) and Kramer shear resistance (Kramer) were included in the regression model (months = 15.003 − 0.001ηapp + 0.144 Kramer; $R_{\rm {adj}}^{2} = 0.91$). The model had a typical error of estimation of 2.0 months. The simplicity of the model, which requires only two parameters, and the easiness of their measurement make the method a good candidate for use in quality control laboratories of hake processing industries. Copyright © 2006 Society of Chemical Industry
Influence of O2 on the quality of virgin olive oil during malaxation
Authors: Migliorini Marzia , Mugelli Marco , Cherubini Chiara , Viti Paolo , Zanoni Bruno
Published: September 2006

The aim of this work was to investigate the effect of malaxation operating conditions on virgin olive oil quality. Legal, sensory and nutritional parameters of olive oil were evaluated by identifying the role played by enzymes. A comparison was made between oil obtained from a traditional malaxation plant and oil obtained from malaxation equipment (LOM) able to work at low oxygen level and temperature. Research results showed that, during malaxation, oxygen had an effect on both phenolic compounds and fatty acids, mainly favouring enzyme phenomena. Malaxation at a low oxygen level was found to be selective for the formation of both phenolic and C6 compounds. Oil obtained from malaxation LOM equipment was shown to be richer in both aldehydes such as trans‐2‐hexenal and phenolic compounds than oil obtained from traditional processing. Copyright © 2006 Society of Chemical Industry