bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of the Distribution of Trace Elements in Six Species of Marine Organisms of the Ligurian Sea (North‐Western Mediterranean) — Comparison with Previous Findings
Authors: Capelli Renzo , Drava Giuliana , Siccardi Camilla , De Pellegrini Rodolfo , Minganti Vincenzo
Published: June 2004

This paper presents the results of the determination of several trace elements (total and organic mercury, selenium, cadmium, lead, copper, manganese and zinc) in six species of marine organisms (Nephrops norvegicus, Engraulis encrasicolus, Mullus barbatus, Mullus surmuletus, Merluccius merluccius, and Sarda sarda), sampled in the Ligurian Sea (North‐West Mediterranean) during a three‐year period, from 1998 to 2000. The species analysed (388 samples) are the same studied in previous investigations in the same area (260 samples), so that a comparison with previous data measured in 1977‐1986 was possible, in order to evaluate the variation of the marine environment in that area with respect to that period. Biological parameters of the specimens (length and weight of the individuals, and also sex for N. norvegicus) were taken into account in order to make possible the comparison between old and new data. No appreciable variation occurred in the levels of the trace elements analysed during the period 1998‐2000, while the comparison with the data collected about 25 years ago showed a decrease of all the elements except for selenium.
Adsorption of Organic Compounds onto Activated Carbons from Recycled Vegetables Biomass
Authors: Mameli Anna , Cincotti Alberto , Lai Nicola , Crisafulli Carmelo , Sciré Salvatore , Cao Giacomo
Published: June 2004

The removal of organic species from aqueous solution by activated carbons is investigated. The latter ones are prepared from olive husks and almond shells. A wide range of surface area values are obtained varying temperature and duration of both carbonization and activation steps. The adsorption isotherm of phenol, catechol and 2, 6‐dichlorophenol involving the activated carbons prepared are obtained at 25 °C. The corresponding behavior is quantitatively correlated using classical isotherm, whose parameters are estimated by fitting the equilibrium data. A two component isotherm (phenol / 2, 6‐dichlorophenol) is determined in order to test activated carbon behavior during competitive adsorption.
Comparing Some Operational Approaches to the Limit of Detection
Authors: Desimoni Elio , Brunetti Barbara , Cattaneo Raffaella
Published: June 2004

The limit of detection is one of the fundamental metrological characteristics of any chemical measurement systems but, even now, it is a highly controversial matter because of the existing differences in terminology, formulations and understanding. Even when limiting the analysis to those operational approaches that, because of their simplicity, are often suggested by the guidelines of some international bodies, the available approaches can return appreciably different estimates. In this paper, the matter is critically reconsidered, and the different approaches compared with the aid of some case studies.
Zero‐Crossing Second Derivative Spectrophotometry for Simultaneous Determination of Palladium and Nickel Using 1‐(2‐Pyridylazo)‐2‐Naphthol in Mixed Micellar Solutions
Authors: Eskandari Habibollah
Published: June 2004

1‐(2‐Pyridylazo)‐2‐naphthol (PAN) has been used for the simultaneous determination of nickel and palladium at trace levels. PAN complexes of nickel and palladium in the pH 1.98 form red and green colored complexes, respectively, which are soluble in aqueous 4:1 Triton X‐100 to sodium dodecylsulfate (SDS) micellar media with total detergent concentration of 3.2 %. Under optimum conditions, calibration graphs for the simultaneous determination by second derivative spectrophotometry were obtained. Zero crossing second derivative spectrophotometry at 668 and 572 nm, respectively for palladium and nickel was used for the simultaneous determination. The method is able to determine palladium to nickel ratio 70:1 to 1:6 (Wt/Wt), accurately. Accuracy and reproducibility of the determination method on the known various amounts of palladium and nickel in their binary mixtures were tested. Effects of diverse ions on the determination of palladium and nickel to investigate selectivity of the method also were studied.
Inhibition of Acidic Corrosion of Carbon Steel by some Mono and Bis Azo Dyes Based on 1, 5 Dihydroxynaphihalene
Authors: Abdallah Metwally , Moustafa Moustafa E.
Published: June 2004

Inhibition of the corrosion of carbon steel in hydrochloric acid solution by some mono‐ and bis‐azo dyes based on 1, 5‐dihydroxynaphthalene was studied in relation to the concentration of inhibitors using weight loss and potentiostatic polarization techniques. The percentage inhibition efficiency calculated from two methods is in a good agreement with each other. The inhibition mechanism of the additives was ascribed to the formation of complex compound adsorbed on the metal surface. The adsorption process follows Freundlich adsorption isotherm. The formation of the complex compound was studied by conductometric and potentiometric titrations. The stability constants of the Fe‐complexes were determined using the latter technique and related to the inhibition efficiency.
Enhanced Sensitivity of a Gas Sensor Incorporating Single‐Walled Carbon Nanotube–Polypyrrole Nanocomposites
Authors: An K. H. , Jeong S. Y. , Hwang H. R. , Lee Y. H.
Published: June 2004

A nanocomposite of polypyrrole/carbon nanotubes prepared by in situ chemical polymerization shows improved conductivity of the polypyrrole as compared with its pure form. Its application as a chemical sensor, made using a simple spin‐casting technique, shows a drastically increased sensitivity. The Figure shows a field‐emission scanning electron microscopy (FE‐SEM) image of the SWNT/Ppy nanocomposite.
Engineering Nanospaces: Iterative Synthesis of Melamine‐Based Dendrimers on Amine‐Functionalized SBA‐15 Leading to Complex Hybrids with Controllable Chemistry and Porosity
Authors: Acosta E. J. , Carr C. S. , Simanek E. E. , Shantz D. F.
Published: June 2004

A series of melamine‐based dendrimers of various generations are grown directly off the surface of amine‐functionalized SBA‐15 (see Figure), demonstrating the feasibility of using functionalized mesoporous silica as a solid‐phase support for organic–inorganic hybrid materials.
Mercury(II) N,N′‐Methyl‐Phenylethyl‐Dithiocarbamate and Its Use as a Precursor for the Room‐Temperature Solution Deposition of β‐HgS Thin Films
Authors: Green M. , Prince P. , Gardener M. , Steed J.
Published: June 2004

Mercury(II) N,N′‐methyl‐phenylethyl‐dithiocarbamate (Figure shows crystal structure) has been prepared and used as a room‐temperature single‐source precursor to a traditionally unstable phase of mercury sulfide.
Dip‐Pen Nanolithography of Chemical Templates on Silicon Oxide
Authors: Kooi S. E. , Baker L. A. , Sheehan P. E. , Whitman L. J.
Published: June 2004

A flexible template strategy for the generation of nanometer‐scale templates via dip‐pen nanolithography is described. Trichlorosilanes are patterned with a chemically modified cantilever, and subsequently oxidized. The reactive template formed can be further modified by covalent attachment (e.g., of poly(ethylene imine), see Figure) or via electrostatic immobilization (e.g., of CdSe).
Hierarchical Structure: Silicon Nanowires Standing on Silica Microwires
Authors: Ye C. , Zhang L. , Fang X. , Wang Y. , Yan P. , Zhao J.
Published: June 2004

A novel hierarchical structure, namely, single‐crystalline Si nanowires standing on silica microwires (see Figure), has been prepared by adopting the disproportionation reaction of SiO with metal tin as a liquid‐forming agent. The intense near‐IR photoluminescence displayed by the hierarchical structures suggests possible applications in nanoscale optoelectronic devices.
Supramolecular Photovoltaic Cells Using Porphyrin Dendrimers and Fullerene
Authors: Hasobe T. , Kashiwagi Y. , Absalom M. A. , Sly J. , Hosomizu K. , Crossley M. J. , Imahori H. , Kamat P. V. , Fukuzumi S.
Published: June 2004

Organic photovoltaic cells made using supramolecular complexes of porphyrin dendrimers with fullerenes demonstrate remarkable enhancement in the photoelectrochemical performance as well as broader photoresponse in the visible and near‐infrared regions relative to the reference system. This demonstrates that molecular assemblies of C60 and porphyrins with dendritic structures are effective in photoenergy conversion systems (see Figure).
Amorphous Calcium Carbonate: Synthesis and Potential Intermediate in Biomineralization
Authors: Faatz M. , Gröhn F. , Wegner G.
Published: June 2004

Amorphous calcium carbonate is produced as spherical particles (see Figure) via in‐situ generation of CO2 by hydrolysis of dialkyl carbonates in aqueous solution of CaCl2 at room temperature. This method of synthesis (precipitation) allows detailed studies of the particle formation process. Temperature‐dependent results are rationalized in terms of a phase diagram that assumes a liquid–liquid immiscibility gap with a lower critical separation temperature.
Encapsulating a Superconducting Material, MgCNi3, in a Carbon Nanoflask
Authors: Rana R. K. , Pol V. G. , Felner I. , Meridor E. , Frydman A. , Gedanken A.
Published: June 2004

MgCNi3 is a non‐oxide perovskite which is both superconducting and ferromagnetic. Here MgCxNi3 is encapsulated in carbon nanoflasks via a chemical method. Magnetic susceptibility measurements indicate the occluded MgCNi3 exhibits a superconducting transition with a critical temperature of 7 K (see Figure).
Efficient Hybrid Solar Cells from Zinc Oxide Nanoparticles and a Conjugated Polymer
Authors: Beek W. J. E. , Wienk M. M. , Janssen R. A. J.
Published: June 2004

ZnO nanoparticles dispersed in a semiconducting polymer form the active layer of a solar cell (see Figure) that is able to convert up to 40 % of the incident photons at 500 nm into electrical current and has a power conversion efficiency of about 1.5 % in sunlight. Manufactured at low temperature using environmentally friendly materials, it represents a new step to ‘green electricity'.
Controllable Synthesis of Highly Luminescent and Monodisperse CdS Nanocrystals by a Two‐Phase Approach under Mild Conditions
Authors: Pan D. , Jiang S. , An L. , Jiang B.
Published: June 2004

Highly luminescent and monodisperse CdS nanocrystals (see Figure) have been synthesized using a two‐phase approach. The synthesis of CdS nanocrystals at the liquid–liquid interface was easy, safe, and highly reproducible, and the reaction conditions were mild and controllable.
Micelle‐Mediated Synthesis of Single‐Crystalline Selenium Nanotubes
Authors: Ma Y. , Qi L. , Ma J. , Cheng H.
Published: June 2004

The large‐scale synthesis of single‐crystal Se nanotubes (e.g., see Figure) has been realized via a novel micelle‐mediated process, the key to which may be the use of micelles to control the distribution of amorphous Se in solution.
Free‐Standing Gold Nanoparticle Membrane by the Spontaneous Reduction of Aqueous Chloroaurate Ions by Oxyethylene‐Linkage‐Bearing Diamine at a Liquid–Liquid Interface
Authors: Selvakannan PR. , Kumar P. S. , More A. S. , Shingte R. D. , Wadgaonkar P. P. , Sastry M.
Published: June 2004

The one‐step synthesis of a free‐standing, robust gold nanoparticle membrane (see Figure) via the spontaneous reduction of aqueous chloroaurate ions by oxyethylene‐bearing diamine molecules in chloroform at the liquid–liquid interface is described. Such simply assembled membranes may have important applications in separation methodologies and as surfaces for enzyme, DNA, and cell immobilization.
In‐Situ End‐Group Functionalization of Regioregular Poly(3‐alkylthiophene) Using the Grignard Metathesis Polymerization Method
Authors: Jeffries‐EL M. , Sauvé G. , McCullough R. D.
Published: June 2004

A facile one‐step synthetic method to functionalize regioregular polythiophene is described (see Figure). End‐group functionalization leads to a number of new uses for these polymers including end‐group‐driven self‐assembly onto surfaces and into conducting polymer networks, and their use as building blocks for the synthesis of block copolymers.
Light Amplification by Optical Excitation of a Chemical Defect in a Conjugated Polymer
Authors: Vehse M. , Liu B. , Edman L. , Bazan G. C. , Heeger A J.
Published: June 2004

A small fraction of narrow‐bandgap benzothiadiazole (BT) ‘defects’ covalently integrated into the main chain of a wide‐bandgap polyfluorene (PF) polymer minimizes self‐absorption effects via efficient energy transfer from absorbing PF segments to emitting BT ‘defects’. A threshold for amplified spontaneous emission in a glass/polymer/air optical waveguide as low as 15 kW cm–2 is achieved.
High‐Quality Ultra‐Fine GaN Nanowires Synthesized Via Chemical Vapor Deposition (Adv. Mater. 2003, 15, 419)
Authors: Chen X. , Xu J. , Wang R.M. , Yu D.
Published: June 2004

To view the original paper use http://dx.doi.org/10.1002/adma.200390097.
Longitudinal evolution of unidentified bright objects in children with neurofibromatosis‐1
Authors: Kraut Michael A. , Gerring Joan P. , Cooper Karen L. , Thompson Richard E. , Denckla Martha B. , Kaufmann Walter E.
Published: June 2004

Neurofibromatosis type‐1 (NF‐1) is the most common autosomal dominant disorder affecting the central nervous system. Magnetic resonance imaging (MRI) has revealed distinctive T2‐weighted hyperintense foci (termed unidentified bright objects, UBOs) which appear to represent spongiform changes in the white matter. Cross‐sectional and longitudinal analyses suggest that UBOs disappear over time; however, none of these studies have examined comprehensively these foci. We conducted a quantitative MRI longitudinal study of number of affected regions, number of UBOs per region, and UBO volume per region, in a sample of 12 children with NF‐1. We applied semi‐automatic morphometric methods and comprehensive statistical approaches, within a detailed anatomical parcellation framework. Our data demonstrate that, despite a similar UBO regional distribution (e.g., prevalent globus pallidus/internal capsule (GP/IC) location), UBO evolution was more complex than previously reported. In some subjects, the total number of UBO‐occupied locations demonstrated a decrease between approximately ages 7 and 12 years, followed by a progressive increase during adolescence. This pattern was also found for UBO number and/or volume for all regions, with the exception of the cerebellar hemispheres. This REGIONAL distinction may reflect differences in white matter structure between affected long tract fiber bundles and that of cerebral and cerebellar myelinated fibers. The findings are also discussed in the context of previous MR and behavioral studies. We conclude that studies like the present one, in association with other MR modalities, are necessary to characterize more completely the nature and evolution of UBOs and their role in the cognitive phenotype of NF‐1. © 2004 Wiley‐Liss, Inc.
Inheritance of most X‐linked traits is not dominant or recessive, just X‐linked
Authors: Dobyns William B. , Filauro Allison , Tomson Brett N. , Chan April S. , Ho Allen W. , Ting Nicholas T. , Oosterwijk Jan C. , Ober Carole
Published: June 2004

The existence of X‐linked disorders in humans has been recognized for many centuries, based on lessons in religious texts and observations of specific human families (e.g., color blindness or Daltonism). Our modern concepts of Mendelian (including X‐linked) inheritance originated just after the turn of the last century. Early concepts of dominance and recessiveness were first used in conjunction with autosomal traits, and then applied to “sex”‐linked traits to distinguish X‐linked recessive and X‐linked dominant inheritance. The former was defined as vertical transmission in which carrier women pass the disorder to affected sons, while the latter was defined as vertical transmission in which daughters of affected males are always affected, transmitting the disorder to offspring of both sexes. However, many X‐linked disorders such as adrenoleukodystrophy, fragile X syndrome, and ornithine transcarbamylase deficiency do not fit these rules. We reviewed the literature on 32 X‐linked disorders and recorded information on penetrance and expressivity in both sexes. As expected, penetrance and an index of severity of the phenotype (defined in our Methods) were both high in males, while the severity index was low in females. Contrary to standard presentations of X‐linked inheritance, penetrance was highly variable in females. Our analysis classified penetrance as high in 28% of the disorders studied, intermediate in 31%, and low in 40%. The high proportion of X‐linked disorders with intermediate penetrance is difficult to reconcile with standard definitions of X‐linked recessive and dominant inheritance. They do not capture the extraordinarily variable expressivity of X‐linked disorders or take into account the multiple mechanisms that can result in disease expression in females, which include cell autonomous expression, skewed X‐inactivation, clonal expansion, and somatic mosaicism. We recommend that use of the terms X‐linked recessive and dominant be discontinued, and that all such disorders be simply described as following “X‐linked” inheritance. © 2004 Wiley‐Liss, Inc.
Mitotic and meiotic instability of a telomere association involving the Y chromosome
Authors: Huang Bing , Martin Christa Lese , Sandlin Constance J. , Wang Shengbiao , Ledbetter David H.
Published: June 2004

Constitutional telomere associations and jumping translocations (JTs) are rare events and usually occur post‐zygotically. We report a telomere association involving the Y chromosome which “jumped” during meiosis. A 21‐year‐old woman was referred for amniocentesis due to non‐immune hydrops seen in a previous pregnancy. Cytogenetic analysis of the amniocytes showed a 45,X,tas(Y;15)[4]/45,X[16] karyotype with the long arm of the Y chromosome attached to the end of the short arm of chromosome 15. Parental chromosome analyzes revealed a tas(Y;19)[63]/45,X[7] karyotype in the father with Yq attached to the end of the short arm of chromosome 19. A phenotypically normal male was born and blood chromosome analysis confirmed a 45,X,tas(Y;15)[39]/45,X[10]/46,XY[1] karyotype. Two other male children have 46,XY karyotypes, which further demonstrates the instability of the tas(Y;19) in meiosis. Fluorescence in situ hybridization (FISH) analysis with probes for theY‐centromere, the Yqh region, the shared Xq/Yq telomere and SRY showed hybridization on the tas(Y;19) and tas(Y;15). A chromosome 19p specific subtelomeric probe showed hybridization to the tas(Y;19) in the father. In addition, a probe for the simple telomeric sequences TTAGGG showed positive hybridization to the junction of the associations. The presence of TTAGGG telomere repeats and unique telomere sequences indicate that the Y;15 and Y;19 associations occur with no detectable loss of any sequences. The interstitial telomere sequences at the junction of the telomere association may explain the mitotic and meiotic instability of the association. © 2004 Wiley‐Liss, Inc.
Diastrophic dysplasia and atelosteogenesis type II as expression of compound heterozygosis: First report of a Mexican patient and genotype–phenotype correlation
Authors: Macías‐Gómez Nelly Margarita , Mégarbané André , Leal‐Ugarte Evelia , Rodríguez‐Rojas Lisa Ximena , Barros‐Núñez Patricio
Published: June 2004

The osteochondrodysplasias represent a heterogeneous group of cartilage and bone diseases. Among these, achondrogenesis 1B, atelosteogenesis type II, diastrophic dysplasia, and autosomal recessive multiple epiphyseal dysplasia are caused by mutations in the solute carrier family 26 (sulfate transporter), member 2 gene (SLC26A2). This group of osteochondrodysplasias shows a continuous spectrum of clinical variability and shares many features in common. Usually, it is difficult to distinguish clinically among these patients. To date, several efforts have been made to correlate mutations in the SLC26A2 gene with phenotypic severity in the patients. We report on a Mexican girl with diastrophic dysplasia presenting some unusual clinical and radiographic features that are usually observed in atelosteogenesis type II. Molecular analysis of the SLC26A2 gene in this patient showed compound heterozygosity for the R178X and R279W mutations. In this patient, the combination of a mild and a severe mutation has apparently led to an intermediate or transitional clinical picture, showing an apparent genotype–phenotype correlation. © 2004 Wiley‐Liss, Inc.
Further delineation of the odonto–onycho–dermal dysplasia syndrome
Authors: Mégarbané Hala , Haddad May , Delague Valérie , Renoux Julien , Boehm Nelly , Mégarbané André
Published: June 2004

We report on three boys, two brothers and their maternal cousin, presenting with dry hair, pilar keratosis, severe hypodontia, smooth tongue, onychodysplasia, and keratoderma and hyperhidrosis of palms and soles. Histology of the skin showed orthokeratotic, hyperkeratosis, hypergranulosis, and mild acanthosis in the epidermis. Scanning electron microscopic examination of the hair showed longitudinal depressions in some hair. These features are close to a rare entity: the odonto–onycho–dermal dysplasia but with some differing features. © 2004 Wiley‐Liss, Inc.
Spondyloperipheral dysplasia is caused by truncating mutations in the C‐propeptide of COL2A1
Authors: Zankl Andreas , Zabel Bernhard , Hilbert Katja , Wildhardt Gabi , Cuenot Segoleine , Xavier Belinda , Ha‐Vinh Russia , Bonafé Luisa , Spranger Jürgen , Superti‐Furga Andrea
Published: June 2004

The term “spondyloperipheral dysplasia” (SPD) has been applied to the unusual combination of platyspondyly and brachydactyly as observed in a small number of individuals. The reported cases show wide clinical variability and the nosologic status and spectrum of this condition are still ill defined. Zabel et al. [1996: Am J Med Genet 63(1):123–128] reported an individual with short stature and SPD who was heterozygous for a frameshift mutation in the C‐propeptide domain of COL2A1. To explain the additional finding of brachydactyly that is not an usual feature of the type II collagenopathies, it was postulated that the nature of the mutation induced precocious calcification and premature fusion of metacarpal and phalangeal growth plates. The C‐propeptide of collagen II had previously been found to promote calcification (“chondrocalcin”). We have ascertained two further individuals with clinical and radiological findings of a type II collagenopathy in infancy who developed brachydactyly type E like changes of fingers and toes in childhood. In both individuals, heterozygosity for novel, distinct mutations in the C‐propeptide coding region of COL2A1 were found. Although all three mutations (the one previously reported and the two novel ones) predict premature termination, their location close to the 3′‐end of the mRNA probably protects them from nonsense‐mediated decay and allows for synthesis of mutant procollagen chains. However, loss of crucial cysteine residues or other sequences essential for trimerization prevents these chains from associating and participating in procollagen helix formation, and thus leads to accumulation in the ER‐consistent with EM findings. The mechanism leading to precocious fusion of phalangeal epiphyses remains to be explored. The consistency of clinical, radiographic, and molecular findings in these three unrelated individuals confirms SPD as a distinct nosologic entity. The diagnosis of SPD is suggested by the appearance of brachydactyly in a child who has clinical and radiographic features of a collagen II disorder. © 2004 Wiley‐Liss, Inc.
Duplication 4p and deletion 4p (Wolf–Hirschhorn syndrome) due to complementary gametes from a 3:1 segregation of a maternal balanced t(4;13)(p16;q11) translocation
Authors: Takeno S.S. , Corbani M. , Andrade J.A.D. , Smith M. de A.C. , Brunoni D. , Melaragno M.I.
Published: June 2004

We present clinical and cytogenetic data on a family with a t(4;13)(p16;q11) translocation present in four generations. The balanced translocation resulted in one individual with monosomy 4p and one individual with trisomy 4p, due to 3:1 segregation. The male patient with trisomy 4p was fertile and transmitted the extra chromosome to his daughter. © 2004 Wiley‐Liss, Inc.
Synthesis and Antimicrobial Activity of New 2‐[p‐Substituted‐benzyl]‐5‐[substituted‐carbonylamino]benzoxazoles
Authors: Yildiz‐Oren Ilkay , Tekiner‐Gulbas Betul , Yalcin Ismail , Temiz‐Arpaci Ozlem , Akı‐Sener Esin , Altanlar Nurten
Published: June 2004

A series of 23 new 2‐[p‐substituted‐benzyl]‐5‐[p‐substituted‐phenyl/benzyl‐carbonylamino]benzoxazole derivatives has been synthesized by reacting 5‐amino‐2‐[p‐substituted‐benzyl]benzoxazoles with the appropriate carboxylic acid chlorides. The structures of the synthesized compounds were confirmed by IR and 1H‐NMR spectral data. Antimicrobial activities of the compounds were investigated using the twofold serial dilution technique against two gram‐positive and two gram‐negative bacteria and three Candida species in comparison with standard drugs. Microbiological results indicated that the newly synthesized 2‐[p‐substituted‐benzyl]‐5‐[p‐substituted‐phenyl/benzyl‐carbonylamino]benzoxazole derivatives (3‐25) possessed a broad spectrum of activity, showing MIC values of 6.25‐200 μg/mL against the gram‐positive and gram‐negative microorganisms tested. Moreover, they showed significant antifungal activity with MIC values of 3.12‐100 μg/mL against the Candida species tested. Especially, with a MIC value of 3.12 μg/mL, 2‐benzyl‐5‐[p‐bromobenzyl‐carbonylamino]benzoxazole 9 displayed the same activity against C. glabrata as the standard drug myconazol.
Synthesis and Evaluation of a Dimer of 2‐(4‐Pyridylmethyl)‐1‐Indanone as a Novel Nonsteroidal Aromatase Inhibitor
Authors: Gupta Ranju , Jindal Dharam Paul , Jit Birinder , Narang Gaurav , Palusczak Anja , Hartmann Rolf W.
Published: June 2004

A novel dimer of 2‐(4‐pyridylmethyl)‐1‐indanone (2) was obtained while carrying out aldol condensation of 1‐indanone with pyridine‐4‐carboxaldehyde in potas sium hydroxide. The structure of dimer 3 has been established using various spectral techniques and was screened for its ability to inhibit the cytochrome P450 enzyme aromatase. The dimer showed strong inhibition of human placental aromatase and was found 3 times more potent (RP = 3, IC50 = 10.2 μM) as compared to aminoglutethimide (RP = 1, IC50 = 18.5 μM
Synthesis of Amidinohydrazones and Evaluation of Their Inhibitory Effect towards Aldosterone Synthase (CYP11B2) and the Formation of Selected Steroids
Authors: Voets Marieke , Müller‐Vieira Ursula , Marchais‐Oberwinkler Sandrine , Hartmann Rolf W.
Published: June 2004

The synthesis and biological evaluation of a series of amidinohydrazones (3a‐h, 6a‐c, 8 and 9) as potential nonsteroidal inhibitors of aldosterone synthase (CYP11B2) are described. The compounds were tested in vitro using CYP11B2‐expressing fission yeast; they showed only marginal inhibitory effect. Compound 6c was evaluated for its effect on the formation of aldosterone, cortisol, androstenedione, and DHEA in the adrenocortical tumor cell line NCI‐H295R. It exhibited no significant effect on the production of these products.
In vivo hyperglycemia and its effect on Glut‐1 expression in the embryonic heart
Authors: Joyner Nia T. , Smoak Ida W.
Published: June 2004

BACKGROUND

Maternal diabetes exposes embryos to periods of hyperglycemia. Glucose is important for normal cardiogenesis, and Glut‐1 is the predominant glucose transporter in the embryo.

METHODS

Pregnant mice were exposed to 6 or 12 hr hyperglycemia during organogenesis using intraperitoneal (IP) injections of D‐glucose on gestational day (GD) 9.5 (plug = GD 0.5). Embryos were examined for morphology and total cardiac protein, and embryonic hearts were evaluated for Glut‐1 protein and mRNA expression immediately after treatment (GD 9.75, GD 10.0), as well as on GD 10.5 and GD 12.5.

RESULTS

IP glucose injections were effective in producing sustained maternal hyperglycemia. Maternal hyperglycemia for 6 or 12 hr on GD 9.5, followed by normoglycemia, produced a decrease in overall size and total cardiac protein in embryos evaluated on GD 10.5 but no difference on GD 12.5. Cardiac Glut‐1 expression was immediately upregulated in embryos exposed to 6 or 12 hr maternal hyperglycemia. On GD 10.5, cardiac Glut‐1 expression was not different in embryos exposed to maternal hyperglycemia for 6 hr but was downregulated in embryos exposed for 12 hr. On GD 12.5, cardiac Glut‐1 expression in embryos exposed to maternal hyperglycemia on GD 9.5 for 6 or 12 hr, followed by normoglycemia, was not different from controls. The temporal pattern was the same for Glut‐1 protein and mRNA expression.

CONCLUSIONS

Hyperglycemia‐induced alterations in Glut‐1 expression likely interfere with balance of glucose available to the embryonic heart that may affect cardiac morphogenesis. Birth Defects Research (Part A), 2004. © 2004 Wiley‐Liss, Inc.
Calmodulin/calmodulin‐dependent protein kinase II mediates SAAF‐induced motility activation of ascidian sperm
Authors: Nomura Mamoru , Yoshida Manabu , Morisawa Masaaki
Published: June 2004

Ca2+‐influx and membrane hyperpolarization by sperm‐activating and ‐attracting factor (SAAF) released from the unfertilized egg of the ascidians Ciona cause a transient increase in cAMP, which triggers activation of sperm motility. We demonstrated here the presence of Ca2+‐binding protein, calmodulin (CaM), and CaM‐dependent kinase II (CaMKII) in the sperm. CaM antagonist, W‐7, and CaMKII inhibitor, KN‐93, suppressed SAAF‐induced membrane hyperpolarization, increase in cAMP, and activation of sperm motility, but inactive analogues of W‐7 and KN‐93, namely W‐5 and KN‐92, respectively, did not. Subsequent addition of K+ ionophore, valinomycin, hyperpolarized the plasma membrane, increased cAMP, and conferred motility to the immotile sperm even in the presence of W‐7 and KN‐93. Addition of IBMX activated motility of sperm, which has been immobilized by W‐7 and KN‐93. These suggest that increased [Ca2+]i through influx of Ca2+ by SAAF binds to CaM to activate CaMKII. The activated CaMKII may cause membrane hyperpolarization to increase cAMP, which triggers the activation of sperm motility in Ciona. Cell Motil. Cytoskeleton 59:28–37, 2004. © 2004 Wiley‐Liss, Inc.
Incubation Time during Chemical Vapor Deposition of Si onto SiO2 from Silane
Authors: Kajikawa Y. , Tsuchiya T. , Noda S. , Komiyama H.
Published: June 2004

Mechanisms controlling the deposition incubation time of Si on SiO2 are studied. Two major mechanisms are considered to affect the incubation time: desorption of adsorbate that is not captured by existing islands, and differing sticking probabilities between islands and substrate. Results indicate that desorption of adsorbate seems to have less contribution and the sticking probability mechanism controls island growth (Figure), and therefore is the main cause for the incubation time in silane CVD processes.
Photocatalytically Active γ‐WO3 Films from Atmospheric Pressure CVD of WOCl4 with Ethyl Acetate or Ethanol
Authors: O'Neill S. , Parkin I.P. , Clark J.H. , Mills A. , Elliott N.
Published: June 2004

Coatings of yellow γ‐WO3 are deposited on glass by APCVD of WOCl4 and either ethanol or ethylacetate at 350–450°C. The yellow films show significant photoactivity for the destruction of stearic acid, and photoinduced superhydrophilicity. Preparation of blue reduced WO2.92 films from the same reaction at higher substrate temperatures of 500–600 °C (Figure) is also found to be possible. These films show no photoactivity, but can be converted into the fully stoichiometric photoactive form simply by heating in air.
Synthesis of Diamond Spheres
Authors: Lee J.‐K. , Baik Y.‐J. , Eun K.Y. , Lee J.‐Y. , Park J.‐W. , John P.
Published: June 2004

Diamond spheres with diameters in the range 150 to 600 nm have been synthesized by multi‐cathode direct current CVD. The diameters of the spheres vary with the radial distance from the centre of the 100 mm diameter copper substrate. The powders are characterized by TEM, Raman spectroscopy, IR spectroscopy, and XRD. TEM patterns show the internal structure to consist of nanocrystalline diamond grains exhibiting a Raman peak at 1334 cm–1, a form of diamond that has potential for a number of important applications including novel abrasives and drug delivery. A mechanism of homogeneous nucleation and growth is proposed.
Random Deposition as a Growth Mode in Atomic Layer Deposition
Authors: Puurunen R.L.
Published: June 2004

Despite the increasing number of successful applications of material growth by atomic layer deposition (ALD), the description of many physicochemical processes that occur during ALD growth is still incomplete. The way the material is arranged on the surface during ALD growth, called the ALD growth mode, defines important material properties, such as when the substrate gets fully covered by the ALD‐grown material, and the surface roughness. This work initiates the theoretical description of ALD growth modes by describing the random deposition growth mode, both qualitatively and quantitatively, by using the growth per cycle as a statistical quantity.
MOCVD of LaAlO3 Films from a Molten Precursor Mixture: Characterization of Liquid, Gas, and Deposited Phases
Authors: Malandrino G. , Condorelli G.G. , Lo Nigro R.
Published: June 2004

The capability of “second‐generation” precursors to act as a solvent of other precursor species, thus yielding a molten multi‐component source, has been investigated in detail. In particular, this novel approach has been applied to the MOCVD process of high quality, epitaxial LaAlO3 thin films on SrTiO3 (100) substrates. The adopted in‐situ strategy involves a molten mixture consisting of the La(hfa)3 • diglyme (Hhfa = 1,1,1,5,5,5‐hexafluoro‐2,4‐pentanedione, diglyme = bis(2‐methoxyethyl)ether) precursor which acts as a solvent for the Al(acac)3 (Hacac = acetylacetone). Thermal analyses and “in situ” Fourier transform infrared (FTIR) spectra of the gas phase proved that the molten multi‐component source possesses suitable stability during vaporization and mass transport processes. The LaAlO3 films have smooth surfaces and are epitaxially grown.
Atomic Layer Deposition of Photocatalytic TiO2 Thin Films from Titanium Tetramethoxide and Water
Authors: Pore V. , Rahtu A. , Leskelä M. , Ritala M. , Sajavaara T. , Keinonen J.
Published: June 2004

Titanium dioxide thin films were grown by atomic layer deposition (ALD) at 200–400 °C from a new titanium precursor, titanium tetramethoxide, and water. As compared with other titanium alkoxides studied earlier, titanium methoxide shows the highest stability with respect to thermal decomposition, and can thus be used over the widest range of temperatures. The films deposited at 250 °C and above were polycrystalline with the anatase structure, whereas those deposited at 200 °C were amorphous. Except for the film deposited at 200 °C, the films contained only minor amounts of carbon and hydrogen residues. The crystalline films were shown to have photocatalytic activity in decomposing both methylene blue in aqueous solution, and solid stearic acid coated on the film surface.
Multiplexed, particle‐based detection of DNA using flow cytometry with 3DNA dendrimers for signal amplification
Authors: Lowe Mary , Spiro Alex , Zhang Yu‐Zhong , Getts Robert
Published: June 2004

Background

Complex mixtures of DNA may be found in environmental and medical samples. There is a need for techniques that can measure low concentrations of target DNAs. For a multiplexed, flow cytometric assay, we show that the signal‐to‐noise ratio for fluorescence detection may be increased with the use of 3DNA dendrimers. A single fluorescent DNA molecule per bead could be detected with conventional flow cytometry instrumentation.

Methods

The analyte consisted of single‐stranded (ss) DNA amplicons that were hybridized to capture probes on the surface of fluorescent polystyrene microspheres (beads) and initially labeled with streptavidin‐R‐phycoerythrin (single‐step labeling). These beads have a low reporter fluorescence background and high efficiency of DNA hybridization. The DNA/SA‐RPE complex was then labeled with 3DNA dendrimers and SA‐RPE. The bead complexes were detected with a Luminex 100 flow cytometer. Bead standards were developed to convert the intensity to the number of SA‐RPE labels per bead and the number of dendrimers per bead.

Results

The dendrimer assay resulted in 10‐fold fluorescence amplification compared with single‐step SA‐RPE labeling. Based on concentration curves of pure target ss‐amplicons, the signal‐to‐noise ratio of the dendrimer assay was greater by a factor of 8.5 over single‐step SA‐RPE labeling. The dendrimer assay was tested on 16S ribosomal DNA amplified from filter retentates of contaminated groundwater. Multiplexed detection of a single dendrimer‐labeled DNA molecule per bead was demonstrated.

Conclusions

Multiplexed detection of DNA hybridization on a single molecule level per bead was achieved with conventional flow cytometry instrumentation. This assay is useful for detecting target DNAs at low concentrations. © 2004 Wiley‐Liss, Inc.
Green fluorescent protein–propidium iodide (GFP‐PI) based assay for flow cytometric measurement of bacterial viability
Authors: Lehtinen Janne , Nuutila Jari , Lilius Esa‐Matti
Published: June 2004

Background

Several staining protocols have been developed for flow cytometric analysis of bacterial viability. One promising method is dual staining with the LIVE/DEAD BacLight bacterial viability kit. In this procedure, cells are treated with two different DNA‐binding dyes (SYTO9 and PI), and viability is estimated according to the proportion of bound stain. SYTO9 diffuses through the intact cell membrane and binds cellular DNA, while PI binds DNA of damaged cells only. This dual‐staining method allows effective separation between viable and dead cells, which is far more difficult to achieve with single staining. Although SYTO9‐PI dual staining is practical for various bacterial viability analyses, the method has a number of disadvantages. Specifically, the passage of SYTO9 through the cell membrane is a slow process, which is significantly accelerated when the integrity of the cell membrane is disrupted. As a result, SYTO9 binding to DNA is considerably enhanced. PI competes for binding sites with SYTO9 and may displace the bound dye. These properties diminish the reliability of the LIVE/DEAD viability kit. In this study, we investigate an alternative method for measuring bacterial viability using a combination of green fluorescent protein (GFP) and PI, with a view to improving data reliability.

Methods

Recombinant Escherichia coli cells with a plasmid containing the gene for jellyfish GFP were stained with PI, and green and red fluorescence were measured by FCM. For comparison, cells containing the plasmid from which gfp was removed were stained with SYTO9 and PI, and analyzed by FCM. Viability was estimated according to the proportion of green and red fluorescence. In addition, bioluminescence and plate counting (other methods to assess viability) were used as reference procedures.

Results

SYTO9‐PI dual staining of bacterial cells revealed three different cell populations: living, compromised, and dead cells. These cell populations were more distinct when the GFP‐PI combination was used instead of dual staining. No differences in sensitivity were observed between the two methods. However, substitution of SYTO9 with GFP accelerated the procedure. Bioluminescence and plate counting results were in agreement with flow cytometric viability data.

Conclusions

In bacterial viability analyses, the GFP‐PI combination provided better distinction between current viability stages of E. coli cells than SYTO9‐PI dual staining. Additionally, the overall procedure was more rapid. No marked differences in sensitivity were observed. © 2004 Wiley‐Liss, Inc.
An analytical system based on a compact flow cytometer for DNA fragment sizing and single‐molecule detection
Authors: Habbersett Robert C. , Jett James H.
Published: June 2004

Background

Previous reports have demonstrated accurate DNA fragment sizing of linear DNA fragments, from 564 to ≈4 × 105 bp, in a flow system. B‐phycoerythrin (B‐PE), commonly used in conventional cytometric applications that require high‐sensitivity, was the first fluorophore detected in flow at the single‐molecule level.

Methods

Dilute solutions of stained DNA fragments or B‐PE were analyzed in a simplified, compact flow system, with enhanced performance and lower cost, utilizing a solid‐state laser and a single‐photon sensing avalanche photodiode detector (SSAPD). Extensive data processing and display software, developed specifically for the photon‐counting data stream, extracts correlated height, width, and area features from bursts of photons due to discrete molecules passing through the sensing region in the flow channel.

Results

DNA fragment sizing in flow has now been demonstrated for SYTOX‐orange–stained fragments ranging in size over 3.4 orders of magnitude, from 125 to 5 × 105 bp. For Lambda bacteriophage DNA (λ DNA; 48.5 kbp) a CV of 1.2 % has been achieved. Analysis of a femtomolar B‐PE solution demonstrates that the bursts of photons from individual molecules can be baseline‐resolved with 0.5 mW of laser power at a signal to noise ratio (SNR) of ≈30, with ≈100 photons detected from each molecule.

Conclusions

A compact, low‐power, high‐sensitivity system detects DNA fragments as small as 125 bp or individual B‐PE molecules in a flowing liquid stream. Demonstrated linearity, sensitivity, and resolution indicate that <1.0 mW of laser power is optimal, permitting further miniaturization of the system and additional cost reduction. Comprehensive analytical software exploits the standard cytometric paradigm of multiple 2D graphs and gating to extract features from classes of individually analyzed biomolecules. This complete system is thus poised to engage high‐sensitivity applications not amenable to conventional flow cytometric instrumentation. © 2004 Wiley‐Liss, Inc.
The polarization of fluorescence of DNA stains depends on the incorporation density of the dye molecules
Authors: Uy Jeanne L. , Asbury Charles L. , Petersen Timothy W. , van den Engh Ger
Published: June 2004

Background

The fluorescence induced by polarized light sources, such as the lasers that are used in flow cytometry, is often polarized and anisotropic. In addition, most optical detector systems are sensitive to the direction of polarization. These two factors influence the accuracy of fluorescence intensity measurements. The intensity of two light sources can be compared only if all details of the direction and degree of polarization are known. In a previous study, we observed that fluorescence polarization might be modified by dye–dye interactions. This report further investigates the role of dye density in fluorescence polarization anisotropy.

Methods

We measured the polarization distribution of samples stained with commonly used DNA dyes. To determine the role of fluorophore proximity, we compared the monomeric and a dimeric form of the DNA dyes ethidium bromide (EB), thiazole orange (TO), and oxazole yellow (YO).

Results

In all dyes sampled, fluorescence polarization is less at high dye concentrations than at low concentrations. The monomeric dyes exhibit a higher degree of polarization than the dimeric dyes of the same species.

Conclusions

The polarization of fluorescence from DNA dyes is related to the density of incorporation into the DNA helix. Energy transfer between molecules that are in close proximity loosens the linkage between the excitation and emission dipoles, thereby reducing the degree of polarization of the emission. © 2004 Wiley‐Liss, Inc.
Whole genome amplification for CGH analysis: Linker‐adapter PCR as the method of choice for difficult and limited samples
Authors: Pirker Christine , Raidl Maria , Steiner Elisabeth , Elbling Leonilla , Holzmann Klaus , Spiegl‐Kreinecker Sabine , Aubele Michaela , Grasl‐Kraupp Bettina , Marosi Christine , Micksche Michael , Berger Walter
Published: June 2004

Background

Comparative genomic hybridization (CGH) is a powerful method to investigate chromosomal imbalances in tumor cells. However, DNA quantity and quality can be limiting factors for successful CGH analysis. The aim of this study was to investigate the applicability of degenerate oligonucleotide‐primed PCR (DOP‐PCR) and a recently developed linker‐adapter‐mediated PCR (LA‐PCR) for whole genome amplification for use in CGH, especially for difficult source material.

Methods

We comparatively analyzed DNA of variable quality derived from different cell/tissue types. Additionally, dilution experiments down to the DNA content of a single cell were performed. FISH and/or classical cytogenetic analyses were used as controls.

Results

In the case of high quality DNA samples, both methods were equally suitable for CGH. When analyzing very small amounts of these DNA samples (equivalent to one or a few human diploid cells), DOP‐PCR‐CGH, but not LA‐PCR‐CGH, frequently produced false‐positive signals (e.g., gains in 1p and 16p, and losses in chromosome 4q). In case of formalin‐fixed paraffin‐embedded tissues, success rates by LA‐PCR‐CGH were significantly higher as compared to DOP‐PCR‐CGH. DNA of minor quality frequently could be analyzed correctly by LA‐PCR‐CGH, but was prone to give false‐positive and/or false‐negative results by DOP‐PCR‐CGH.

Conclusions

LA‐PCR is superior to DOP‐PCR for amplification of DNA for CGH analysis, especially in the case of very limited or partly degraded source material. © 2004 Wiley‐Liss, Inc.
Role ofSonic hedgehogin patterning of tracheal–bronchial cartilage and the peripheral lung
Authors: Miller Leigh‐Anne D. , Wert Susan E. , Clark Jean C. , Xu Yan , Perl Anne‐Karina T. , Whitsett Jeffrey A.
Published: June 2004

Sonic hedgehog(Shh) was conditionally deleted in respiratory epithelial cells of the embryonic lung in vivo. Deletion ofShhbefore embryonic day (E) 13.5 resulted in respiratory failure at birth. While lobulation was not perturbed, the lungs were hypoplastic, with reduced branching of peripheral lung tubules, evident from E13.5. Smooth muscle and endothelial cells were absent or reduced, the latter in relationship to the loss of peripheral lung parenchyma. Tracheal–bronchial ring abnormalities occurred whenShhwas deleted between E8.5 and E12.5. Deletion ofShhlater in gestation (after E13.5) caused mild abrogation of peripheral branching morphogenesis but did not disrupt tracheal‐bronchial development. Defects in branching morphogenesis and vascularization seen inShhnull mutant (Shh‐/‐) mice were substantially corrected when SHH was ectopically expressed in the respiratory epithelium; however, peripheral expression of SHH failed to correct cartilage abnormalities in the trachea and bronchi, indicating a spatial requirement for SHH expression near sites of cartilage formation. Expression of SHH by the respiratory epithelium plays an important role in the patterning of tracheal–bronchial mesenchyme required for formation of cartilage rings in conducting airways. SHH regulates branching morphogenesis and influences differentiation of the peripheral lung mesenchyme required for formation of bronchial and vascular smooth muscle. Developmental Dynamics 231:57–71, 2004. © 2004 Wiley‐Liss, Inc.