bluuebunny/crossref_metadata_2025 huggingface dataset:
Nine-Vertex Polyhedral Monoazaborane Chemistry: Synthesis and NMR Characterization of exo-6-Ligand-arachno-4-azanonaboranes(11), 6-L-4-NB8H11
Authors: Jelínek Tomáš , Štíbr Bohumil , Kennedy John D.
Published: July 2002

Reactions between arachno-4-NB8H13 and Lewis bases L in dichloromethane or without solvent generate the previously unreported series of arachno compounds exo-6-L-arachno-4-NB8H11, where L = pyridine (py), quinoline (quin), isoquinoline (i-quin), urotropine (uro), and MeCN. These are characterized by mass spectrometry together with 11B and 1H NMR spectroscopy. The NMR results permit complete assignment of all resonances and thence permit comparison with the structurally similar compounds exo-6-L-arachno-4-EB8H10 (for E = CH2 or S).
Quantitative Relationships Between Inhibition of Photosynthesis and Lipophilicity of Piperidinoethyl Alkoxyphenylcarbamates
Authors: Kráľová Katarína , Loos Dušan , Čižmárik Jozef
Published: July 2002

Piperidinoethyl esters of 2-, 3- and 4-alkoxy substituted phenylcarbamic acids (PAPC) inhibit photosynthetic processes in alga Chlorella vulgaris and spinach chloroplasts. These inhibitory activities of PAPC were correlated with chromatographically determined lipophilicity characteristics log k' (from HPLC) and Kovats indices KIO (from gas chromatography) using parabolic and bilinear model. Both theoretical models are suitable for description of studied correlations, however from the viewpoint of statistical analysis Kubinyi's bilinear model gives better results.
Analogues of the Cholecystokinin C-Terminal Tetrapeptide
Authors: Hlaváček Jan , Marcová Renáta , Maletínská Lenka , Slaninová Jiřina
Published: July 2002

Substituted phenylethyl amides and phenylethyl esters Va - Vj derived from the carboxyterminal tetrapeptide part of the cholecystokinin were synthesized and their biological properties assayed. In the original CCK tetrapeptide structure Trp-Met-Asp-Phe-NH2 the Met was replaced by Lys(Pamc) and the terminal Phe-NH2 was replaced by Phe-NHCH2C6H5 or Phe-OCH2C6H5 moiety with a various degree of alkylation in the Ph ring. A bioassay revealed that these simple CCK analogues were selectively bound to A receptors from pancreas, whereas no binding to B receptors from brain was found. Some of the compounds behaved as weak inhibitors of CCK activity on gall bladder and guinea pig ileum contractions without any effect in anorectic assay.
Electron Donating and Acid-Base Properties of Cerium Oxide and Its Mixed Oxides with Alumina
Authors: Sugunan Sankaran , Jalaja Jacob M.
Published: July 2002

The electron donating properties of ceria activated at 300, 500 and 800 °C and its mixed oxides with alumina are reported from the studies on adsorption of electron acceptors of various electron affinity. The surface acidity/basicity of the oxides have been determined by titration method and H0,max values are reported. The limit of electron transfer from oxide surface is between 1.77 and 2.40 eV in terms of the electron affinity of the electron acceptor. Ceria promotes the electron donating of alumina without changing the limit of electron transfer.
A Comparative Study of the Variable Screening and Hartree-Fock Models as Means for the Construction of Two-Center Correlation Diagrams
Authors: Lörinčík Jan , Polák Rudolf , Šroubek Zdeněk , Paidarová Ivana
Published: July 2002

The aim of this work is to test the Variable Screening Model (VSM) [Wille U., Hippler R.: Phys. Rep. 132, 129 (1986)] as a method for computing correlation diagrams of neutral and ionized diatomic quasimolecules by comparing the results with corresponding Hartree-Fock calculations, and to elucidate the specific features of both aforementioned approaches in applications to given purpose. These calculations serve as the first step in the interpretation of inner-shell vacancy production in low-velocity ion-atom collisions inside bombarded solids.
A Capillary Glass Reactor for Polygalacturonase Immobilization
Authors: Stratilová Eva , Čapka Martin , Czakóová Marie , Haladej Ludvík , Rexová-Benková Lubomíra
Published: July 2002

Polygalacturonase was immobilized onto a set of nonporous glass columns of the capillary reactor functionalized with aminopropyl and epoxy groups. The properties of the anchored catalysts in relation to the accessibility of the reaction sites toward polymeric and low-molecular substrates are reported.
A Study of Transmission Effects of Sulfonyl and Carbonyl Groups
Authors: Ludwig Miroslav , Pařík Patrik , Kulhánek Jiří
Published: July 2002

Seventeen p-substituted N-phenylsulfonylbenzamides of general formulas XC6H4SO2NHCOC6H5 and C6H5SO2NHCOC6H4X have been synthesized and their structure has been confirmed by elemental analysis and 1H NMR spectra. The dissociation constants of all the compounds have been measured by potentiometric titration in methanol, acetonitrile, dimethylformamide, dimethyl sulfoxide, and pyridine. The obtained pKHA values have been correlated with three sets of Hammett substituent constants using simple or double linear regression. The solvent and substituent effects are discussed on the basis of experimental results, and the difference between the substituent effects from sulfonamide and benzamide sections is evaluated. It has been found that due to the extensive delocalization of negative charge in the conjugated base the transmission effects of carbonyl and sulfonyl groups on the transmission of substituent effect are roughly the same. The experimental data have been interpreted by the methods with latent variables: the principal component analysis (PCA), the conjugated deviation analysis (CDA), and the method of projection to latent structures (PLS). The results obtained by these procedures were similar.
Sorption of Water Soluble Organic Dyes on Magnetic Poly(oxy-2,6-dimethyl-1,4-phenylene)
Authors: Šafařík Ivo , Šafaříková Miroslava , Buřičová Vlasta
Published: July 2002

Magnetic composite based on poly(oxy-2,6-dimethyl-1,4-phenylene) (PODMP) was prepared by melting the polymer with ε-caprolactam in a presence of fine magnetite particles. Magnetic PODMP was used for sorption of water soluble organic compounds (dyes belonging to triphenylmethane, heteropolycyclic and azo dye groups) from water solutions. There were considerable differences in the binding of the dyes tested. In general, heteropolycyclic dyes exhibited the lowest sorption.
Lipase Immobilized by Sol-Gel Technique in Layers
Authors: Kuncová Gabriela , Guglielmi Massimo , Dubina Pavel , Šafář Bohuslav
Published: July 2002

Commercial lipase was immobilized into an organic-inorganic matrix formed by hydrolysis of silicon alkoxides (tetraethoxysilane, dimethyldiethoxysilane and methyltriethoxysilane) with (3-aminopropyl)triethoxysilane, (3-thiopropyl)trimethoxysilane and chlorodiisopropyloctylsilane. Hydrolytic activity of lipase was tested after addition of the enzyme to a prepolymer solution, after gelation, in xerogel particles and in thin layers deposited on glass slides by dip- or spin-coating. The prepolymer containing NH groups showed the higher activity then the native enzyme.
Chemometric Analysis of Substituent Effects. IX. Alternative Interpretation of Substituent Effects (AISE) - Orthogonal Model
Authors: Pytela Oldřich
Published: July 2002

Continuing the previous communications, the present paper suggests an orthogonal model of alternative interpretation of substituent effects (AISE). Following this approach, substituents are classified into three classes. Those of class II are defined as substituents whose atom bound to the basic skeleton bears a character of nucleophile, i.e. it is able of an intramolecular nucleophilic interaction with the reaction centre. The class III includes substituents whose atom bound to the basic skeleton is electrophilic in nature and can correspondingly interact with the reaction centre too. The class I includes the substituents possessing none of the above-mentioned characteristics. Within the model suggested the substituent effects can be described by a family of three lines corresponding to the substituent classes described with a single substituent constant at the coordinate axis. The validity of the model suggested has successfully been tested by comparison with other correlation equations using 318 reaction series taken from literature. It has been found that the value of the point of intersection at the coordinate axis (the isosubstituent constant) is smaller in processes with electron deficit and grater in those with electron excess in the reaction centre. The slopes of the individual lines in the family of lines (the reaction constants) decrease in the order II > I > III in most cases, the only exception being the processes with direct conjugation between a negatively charged reaction centre and the substituent and some gas phase processes.
Correlation Between GC Retention Data and Relative Molecular Weight of N,N-Bis(2,2,2-trifluoroethyl)dithiocarbamates of Some Divalent Metals
Authors: Hrouzek Ján , Krupčík Ján , Skačáni Ivan
Published: July 2002

The correlation of gas-chromatographic retention data (retention times and linear retention indices) and relative molecular weight was examined for N,N-bis(2,2,2-trifluoroethyl)dithiocarbamate chelates of some divalent metals. Regression analysis of data obtained by capillary GC on a non-polar column heated by applying a dual-ramp temperature programme gave linear dependences possessing reasonable correlation coefficients.
Sequencing Strategy for a Protein-Linked Genome: Spontaneous Reversions of Ochre Triplet in the Phage ϕ29 Gene 17
Authors: Fučík Vladimír , Chaloupecký Vladimír , Beran Jaroslav , Jonák Jiří
Published: July 2002

A direct method using T7 gene 6 exonuclease to prepare single-stranded templates was adapted for the sequencing of the phage ϕ29 genome carrying a covalently linked terminal protein at the 5' ends of both DNA chains. The terminal protein was found to block completely the action of the exonuclease. The treatment of the phage DNA by proteinase K did not restore the accessibility of the 5' ends to the exonuclease to the full extent but only partially. The digestion of proteinase K-treated terminal fragments of the genome by 5' exonuclease could proceed now from both 5' ends, however, at different rates. The delay of exonucleolytic digestion apparently due to residual amino acid(s) was calculated to be about 800 nucleotides. The relative rates of exonucleolytic splitting of both chains were of decisive significance for the choice of suitable primers for the sequencing of desired regions. In all Sus+ revertants sequenced by the described method the TAA(ochre) codon in the gene 17 was found changed either to the original CAA(Gln) or to TAT(Tyr) with the same frequencies.
Kinetics of Cyclization of Methyl S-(2,4,6-Trinitrophenyl)mercaptoacetate to 2-Methoxycarbonyl-5,7-dinitrobenzo[d]thiazol-3-oxide
Authors: Janík Marek , Macháček Vladimír , Pytela Oldřich
Published: July 2002

The cyclization kinetics of methyl S-(2,4,6-trinitrophenyl)mercaptoacetate to 2-methoxycarbonyl-5,7-dinitrobenzo[d]thiazol-3-oxide have been studied in acetate, methoxyacetate or N-methylmorpholine buffers. In the acetate and methoxyacetate buffers, the cyclization obeys the rate equation v = [SH](k'MeO[CH3O-] + k'B[B-] + k'B,MeO[B-][CH3O-]) and goes by two reaction paths differing in the order of their reaction steps, the splitting off of the proton from C-H group being the rate-limiting step in either path. In the N-methylmorpholine buffers, increasing concentration of the base results in gradual decrease of reaction order in the base and change in the rate-limiting step of cyclization. Methyl S-(2,4-dinitrophenyl)mercaptoacetate undergoes cyclization neither in the given buffers nor in methoxide solution.
Glycosylation of Triterpene Alcohols and Acids of the Lupane and A-Secolupane Series
Authors: Klinotová Eva , Křeček Václav , Klinot Jiří , Endová Magdalena , Eisenreichová Jana , Buděšínský Miloš , Štícha Martin
Published: July 2002

A series of 3- and 28-glucosides and glucosyl esters of betulinic acid (1a), 28-hydroxy-3,4-secolupa-4(23),20(29)-dien-3-oic acid (22a), dimethyl ester of 28-hydroxy-2,3-secolup-20(29)-en-2,3-dioic acid (43a), their 20(29)-dihydro derivatives (1b, 22b, 43b) and several other triterpenes of the lupane (12a, 12b) and 3,4-secolupane series (18a, 18b, 32a) has been prepared by reaction of tetra-O-acetyl-α-D-glucopyranosyl bromide in acetonitrile in the presence of mercury(II) cyanide and subsequent deacetylation of the obtained tetra-O-acetyl-β-D-glucopyranosyl derivatives. In several cases attempted glucosylation in the presence of silver silicate afforded predominantly the corresponding 1,2-orthoacetates of α-D-glucopyranose.
Synergism Between Ni and W in the Ni-W/C Sulfide Catalyst in Hydrodenitrogenation of Pyridine and Hydrodesulfurization of Thiophene
Authors: Gulková Daniela , Zdražil Miroslav
Published: July 2002

Parallel hydrodenitrogenation (HDN) of pyridine and hydrodesulfurization (HDS) of thiophene was studied over active-carbon-supported Ni, W, and Ni-W sulfide catalysts at 2 MPa and at 280 and 320 °C. Synergism between Ni and W was observed both in HDN and HDS reactions: the activity of the Ni-W catalyst was higher than the sum of the activities of the Ni and W catalysts. However, the synergistic increase in activity was much higher in HDS than in HDN. This led to a characteristic shift in the HDN/HDS selectivity, which was strongly shifted to the HDS side over the Ni-W catalysts as compared with the Ni and W catalysts. HDS was faster than HDN over the Ni-W catalyst, the rate of both reactions being about the same over the Ni catalyst and HDN being faster than HDS over the W catalyst. The selectivity of all the catalysts was shifted to the HDN side with decreasing temperature. The data are a new example for generalisation of the rule that the synergism in activity of bimetallic sulfide Co-Mo, Ni-Mo, and Ni-W catalysts is higher in HDS than in hydrogenation and HDN.
Cation-π Interactions in the Solid State: Crystal Structures of M+(benzene)2CB11Me12- (M = Tl, Cs, Rb, K, Na) and Li+(toluene)CB11Me12-
Authors: King Benjamin T. , Noll Bruce C. , Michl Josef
Published: July 2002

In these crystal structures, the relatively weak electrostatic interactions between the bulky CB11Me12- anion and the title cations permit cation-π interactions in the solid state. In all cases, single-crystal X-ray diffraction analysis reveals η6-arene-cation interactions within 10% of the expected van der Waals distance. The Tl+, Cs+, Rb+, and K+ structures are isomorphous, with the benzene molecules sandwiching the cation and four anions equatorially disposed in a nearly square arrangement. Both the cation and the near-square of closest anions are positioned to interact favorably with the local dipoles of benzene. The smaller Na+ crystallizes in polymeric chains with a nearly tetrahedrally coordinated cation in van der Waals contact with two anions and two benzene molecules in a tilted-sandwich arrangement. The Li+ structure possesses two motifs, a simple van der Waals sandwich of a toluene molecule and an anion, and chains of half-occupied toluene-Li complexes on inversion centers between anions. The simple van der Waals model is reasonably accurate for the cation-arene distances, only slightly underestimating the separation (2-10% deviation), with worse agreement for the smaller cations.
Fused Thiazoloandrostanes and Their Quaternary Salts, Synthesis and Cooperative Ligand Binding to Muscarinic Acetylcholine Receptor
Authors: Urbanský Marek , Proška Jan , Drašar Pavel
Published: July 2002

Steroidal thiazolium salts were prepared and their interaction with [3H]N-methylscopolamine ([3H]NMS) at M2 muscarinic receptors using radioligand binding were studied. The results were consistent with a ternary complex theory. The compounds diminished [3H]NMS binding with Kd values in the micromolar or submicromolar range. In particular, the presence of bulky benzylic group at the thiazole nitrogen atom caused a substantial increase in affinity of allosteric ligand for receptor. Our results demonstrate that steroidal thiazolium salts could be a new class of potentially useful tools for mapping the muscarinic receptors.
Truxillic Acid Derivatives, Neuromuscular Blocking Agents with Very High Affinity for the Allosteric Binding Site of Muscarinic Acetylcholine Receptors
Authors: Urbanský Marek , Proška Jan , Říčný Jan , Drašar Pavel
Published: July 2002

Bis-quaternary salts of 3-piperidinopropyl esters of α-truxillic acid were synthesized in order to study their allosteric action on muscarinic acetylcholine receptor. Using radioligand binding studies, it has been demonstrated that most of prepared compounds bind with high affinity to the allosteric binding site of M2 muscarinic receptor subtype (Kd values in the range 1-10 nM). Bulky substitution of the quaternary ammonium center led to effective positive modulators of [3H]N-methylscopolamine binding to M2 receptors. Due to its high allosteric potency, the structure of phenacyl derivative seems to be the most promising candidate for future design of photoaffinity probes or radiolabelled ligands for mapping the allosteric binding site.
6-(Hydroxyphenyl)imidazo[2,1-b]thiazoles as Potential Antiinflammatory Agents: Effects on Human Neutrophil Functions
Authors: Andreani Aldo , Rambaldi Mirella , Leoni Alberto , Locatelli Alessandra , Morigi Rita , Traniello Serena , Cariani Alessio , Rizzuti Olivia , Spisani Susanna
Published: July 2002

Synthesis of 6-(hydroxyphenyl)imidazo[2,1-b]thiazoles related to levamisole from the corresponding methoxy derivatives is reported. These compounds were tested on in vitro neutrophil activation, namely locomotion induced by chemoattractants, superoxide generation and lysozyme degranulation triggered by agonists. These functions were evaluated after cell pulse with different concentrations of the drugs. Several derivatives showed significant inhibitory effects, in some cases more potent than the parent compound.
Circular Dichroism and Conformational Analysis of Diastereomeric Bicamphors
Authors: Boiadjiev Stefan E. , Lightner David A.
Published: July 2002

Stereospecific syntheses afforded endo,endo- (1) and exo,exo- (2) bicamphors, while the third possible diastereomeric exo,endo-bicamphor (3) originated from nonselective camphor radical dimerization. The stereochemistry of bicamphor linkage was confirmed by 1H NMR analysis. Chiroptical and ultraviolet spectral data are presented for the three diastereomers 1-3 to show interchromophoric interaction. Conformational analysis to evaluate the relative orientation of each pair of carbonyl chromophores was accomplished by 1H NMR spectroscopy and molecular mechanics calculations.
Synthesis of Acyclic Nucleoside and Nucleotide Analogs Derived from 6-Amino-7H-purin-8(9H)-one
Authors: Janeba Zlatko , Holý Antonín , Masojídková Milena
Published: July 2002

Reaction of 8-bromoadenine derivatives2with sodium acetate in acetic acid and cleavage of (S)-7-[(trityloxy)methyl]-7,8-dihydro[1,3]oxazolo[3,2-e]purin-4-amine (12) and diisopropyl (S)-{[(4-amino-8,9-dihydro-7H-[1,3]oxazino[3,2-e]purin-8-yl)oxy]methyl}phosphonate (13a) were used for the synthesis of the corresponding N9-substituted derivatives of 6-amino- 7H-purin-8(9H)-one3a-3cand7. Alkylation of 6-amino-7H-purin-8(9H)-one (3a) with diverse alkylation agents afforded the title N9-monosubstituted3b,3dand7aand N7,N9-disub- stituted acyclic nucleoside and nucleotide analogs6b,6dand8a.
Preliminary Investigations of High-Frequency Atmospheric-Pressure Plasma Jet for Atomic Emission Spectrometry
Authors: Štěpán Martin , Semerád Martin , Kanický Viktor , Otruba Vítězslav
Published: July 2002

The 27.12- and 13.56-MHz plasma-jet discharges are generated in argon at atmospheric pressure. The plasma originates inside the nozzle of the bored metal power electrode and outflows against the counter-electrode. The discharge has a column shape with the diameter about 0.7-1.5 mm and the length 5-30 mm. The 27.12 MHz/100 W and 13.56 MHz/1 500 W generators are operated at a power of 100 and 200 W, respectively. Stable discharges are obtained within the range from 0.3 to 0.9 dm3 min-1 Ar. The 27.12 MHz/100 W discharge is capable of accepting dry aerosol while the wet aerosol extinguishes this plasma. On the contrary, wet aerosol can be introduced into the 13.56 MHz/200 W plasma. The vibrational temperature of 3 000 K has been determined based on the intensity of the molecular band of the N2 2nd positive system (365-383 nm) in the 27.12 MHz discharge. Intensity vs concentration dependences have been measured with Li 670.784, Na 588.995, Na 589.592, K 766.491 and Rb 780.023 nm lines. Limits of detection in the 27.12 MHz/100 W discharge coupled to an ultrasonic nebulizer with desolvation are 0.1 Li, 30 Na, 10 K and 3 ng cm-3 Rb. Limits of detection in the 13.56 MHz/200 W discharge connected to a pneumatic concentric Meinhard nebulizer is 8 ng cm-3 Li.
Synthesis of Trichloro(η5-alkenyltetramethylcyclopentadienyl)titanium(IV) Complexes and Their Activity in Styrene Polymerization
Authors: Zemánek Jaroslav , Fröhlichová Lenka , Šindelář Pavel , Štěpnička Petr , Císařová Ivana , Varga Vojtech , Horáček Michal , Mach Karel
Published: July 2002

Fully substituted trichloro(η5-cyclopentadienyl)titanium(IV) complexes with pendant alkenyl groups, [TiCl3(η5-C5Me4R)] (R = CH(Me)CH=CH2 (3a), (CH2)2CH=CH2 (3b), and (CH2)3CH=CH2 (3c)), were synthesized by the reaction of the corresponding trimethylsilyl or trimethylstannyl substituted cyclopentadienes C5Me4R(EMe3), where E = Si or Sn, with TiCl4. In all cases, the pendant double bonds did not exhibit any interaction with the titanium atoms as indicated by 1H, 13C NMR or IR spectra as well as by the solid-state structure of 3c. The catalytic systems prepared by mixing complexes 3a-3c, [TiCl3(η5-C5Me5)], [TiCl3(η5-C5H5)], and similar complexes with R = butyl (4), phenyl (5), 4-fluorophenyl (6) with methylalumoxane (MAO) at the molar ratio Al/Ti = 500 catalyzed polymerization of styrene to syndiotactic polystyrene. Their polymerization activities increase in the order: [TiCl3(η5-C5Me5)] < 3a < 3b < 3c < 4 < 5 < 6 < [TiCl3(η5-C5H5)], while the molecular weights (Mw) of syndiotactic polystyrene grow in the order: [TiCl3(η5-C5H5)] < 3a <3b < 4 ≈ 6 < [TiCl3(η5-C5Me5)] < 3c ≈ 5 (maximum Mw ca 3.0 · 105). A comparison of the results for the catalytic systems based on 4 with those derived from 3a-3c points to a rather weak competition of the pendant double bonds with monomer for a cationic Ti(III) catalytic centre.
Transport of Amino Acids Through Charged Cation-Exchange Membrane
Authors: Kara Huseyin , Yazicigil Zafer , Durmaz Fatih , Ersoz Mustafa
Published: July 2002

The sorption and transport of amino acids such as glycine, L-valine and L-leucine through charged polysulfone membranes was investigated as a function of pH lower than 5.6 under three different interfacial conditions. The sorption was characterized by the Langmuir and the Freundlich equations. The highest permeability was obtained if the initial pH on the amino acid source side was 5.6 and that on the opposite side 2.5, the intermediate permeability was obtained if the initial pH on both sides was 2.5, and the smallest permeability was obtained if the initial pH on the amino acid side was 5.6. The obtained results are explained in terms of the interfacial transport based on the chemical reaction (protonation and ion exchange).
Synthesis and Antifungal Activity Evaluation of 3-Hetaryl-2,5-dihydrofuran-2-ones. An Unusual Fragmentation of the Oxazole Ring via 2,3-Selenoxide Shift
Authors: Kuneš Jiří , Balšánek Vojtěch , Pour Milan , Buchta Vladimír
Published: July 2002

In continuing the studies on the synthesis and evaluation of antifungal activity of the analogues of (-)incrustoporine, the replacement of the phenyl moiety at C3 of the furanone ring with a hetaryl substituent was considered. Thus, a series of 5-alkyl-3-hetaryl-2,5-dihydrofuran-2-ones with the thienyl, furyl and thiazolyl moieties attached to C3 was synthesized, and the compounds subjected to antifungal activity screening. In the preparation of compounds containing the oxazolyl fragment, the [2,3]-sigmatropic rearrangement led to the fragmentation of the oxazole ring, resulting in the formation of 3-(1-benzamido-2-oxoethylidene)-5-methyltetrahydrofuran-2-one. Somewhat surprisingly, the antifungal efficiency of the derivatives was lower in comparison with analogues containing a substituted phenyl at C3.
Promoting physical activity in general practice: a controlled trial of written advice and information materials
Authors: Smith Ben J , Bauman Adrian E , Bull Fiona C , Booth Michael L , Harris Mark F
Published: July 2002

Objective—To investigate the impact of a simple written prescription for physical activity given by a general practitioner and the effect of supplementing this with mailed information materials about physical activity.

Methods—A controlled trial was conducted in 27 general practices in New South Wales, Australia. Subjects were sequential routine care patients between 25 and 65 years old. Controls (n = 386) were recruited first, and intervention subjects two weeks later. Intervention subjects were randomised to receive a prescription only (n = 380) or a prescription plus a mailed booklet (n = 376). Self reported physical activity levels were measured by interview at baseline, 6–10 weeks, and seven to eight months.

Results—By intention to treat, the average changes in minutes of total physical activity did not differ significantly between the groups. Inactive people in the prescription plus supplementary booklet group were significantly more likely than controls to report an increase in their physical activity by at least 60 min/week after 6–10 weeks (odds ratio 1.58, 95% confidence interval 1.06 to 2.35). No significant short term improvements in self reported activity were shown in the prescription only group. In the supplemented group, the proportion reporting an increase in physical activity to 3344 kJ/week at 6–10 weeks was not significant, and neither intervention group showed significant increases in any of the outcome measures at seven to eight months by intention to treat. Treatment received analysis showed greater improvements in intervention groups, especially the prescription plus booklet group, in which the odds of inactive people in this group reporting increased activity became significant at seven to eight months.

Conclusions—A prescription for physical activity from a general practitioner, supplemented by additional written materials, can lead to modest short term improvements in self reported physical activity levels among inactive patients. A prescription alone was found not to be effective.
Dental evaluation of scuba diving mouthpieces using a subject assessment index and radiological analysis of jaw position
Authors: Hobson R S , Newton J P
Published: July 2002

Objective—To compare two experimental scuba mouthpieces with a commercially available design.

Methods—A laboratory study using six men to assess effort, muscle pain, muscle fatigue, facial discomfort, tooth discomfort, and loss of lip sensation using a visual analogue scale. Cephalometric radiographs and analysis of jaw position with each mouth piece were also used.

Results—Fully customised mouthpieces caused the least discomfort, muscle pain, fatigue, and effort. They also resulted in the least mandibular displacement from the resting position. Radiographic analysis of jaw position showed that the fully customised design resulted in the least displacement from normal jaw position.

Conclusions—A fully customised design gives the greatest comfort, least effort, and least mandibular displacement. This design is recommended, particularly for divers who experience temporomandibular dysfunction associated with diving.
A systematic review of interventions to prevent lower limb soft tissue running injuries
Authors: Yeung E W , Yeung S S
Published: July 2002

Objectives—To assess the available evidence for preventive strategies for lower limb soft tissue injuries caused by running.

Methods—An electronic database search was conducted using The Cochrane Musculoskeletal Injuries Group Specialised Register, The Cochrane Controlled Trials Register, Medline, Embase, Sport Discus, Heracles, Atlantes, Biosis, Cinahl, Scisearch, Current Contents, Index To Theses and Dissertation Abstracts. Any randomised or quasi-randomised trials evaluating interventions to prevent running injuries to lower limb soft tissue were included. The eligibility of trials for inclusion and the quality of the trials were independently assessed by two reviewers.

Results—Exposure to a high training load (duration, frequency, or running distance) increases the risk of injury, and thus modification of the training schedule can reduce the incidence of injury. The effectiveness of stretching exercises and of insoles in the prevention of lower extremity soft tissue injuries caused by running is not known. Wearing a knee brace with a patellar support ring may be effective in the prevention of anterior knee pain caused by running.

Conclusions—This review provides evidence for the effectiveness of the modification of training schedules in reducing lower limb soft tissue running injuries. More studies are required to quantify the optimal training loads and to confirm that knee braces can prevent knee pain. It is important to note that the studies included in this review had few female participants therefore the results may not be generalisable.
Surgical treatment for chronic Achilles tendinopathy: a prospective seven month follow up study
Authors: Paavola M , Kannus P , Orava S , Pasanen M , Järvinen M
Published: July 2002

Objective:To prospectively assess the early results of surgical treatment of chronic Achilles tendinopathy.

Methods:This seven month prospective follow up study assessed the short term results of surgical treatment of chronic Achilles tendinopathy and compared the subjective and functional outcome of patients with Achilles tendinopathy without a local intratendinous lesion (group A) with that of similar patients with such a lesion (group B). Forty two of the initial 50 patients were examined before surgery and after the seven month follow up. Evaluation included an interview, subjective evaluation, clinical tests, and a performance test.

Results:At the follow up, physical activity was fully restored in 28 of the 42 patients (67%), and 35 patients (83%) were asymptomatic or had only mild pain during strenuous exercise. In clinical tests, significant improvements were observed in climbing up and down stairs and the rising on the toes test. Surgical treatment also seemed to be successful from the total test score, which was excellent or good in 35 patients, compared with before surgery when it was excellent or good in one patient only. Patients in group A fared better than those in group B, whether evaluated by recovery of physical activity after surgery (88%v54%) or the complication rate (6%v27%).

Conclusions:Surgical treatment of chronic Achilles tendinopathy gives good and acceptable short term results. A lower complication rate and a trend to better recovery was observed in patients with peritendinous adhesions only than in those with peritendinous adhesions combined with an intratendinous lesion.
Truth-telling and patient diagnoses
Authors: Sullivan Robert J , Menapace Lawrence W , White Royce M
Published: July 2002

How do physicians handle informing patients of their diagnoses and how much information do patients really want? How do registered nurses view both sides of this question?

Three questionnaires were constructed and administered in a mid-size hospital in New York state. Physicians and nurses underestimate the number of patients who want detailed information. Patients who earn more than average, have a college education, and who are under age 60 are more likely to want information, and state that their physician should give it to them. Only 42% of physicians state that patients want a detailed description of their diagnosis and treatment options. Physicians educated outside the USA appeared to be more likely to change their criteria for informing patients and, along with American-educated nurses, were more willing to participate in formal discussions of the issue.

Physicians should comply with the wishes of patients for information and include them in the team deciding on diagnosis and treatment.
A survey of newly appointed consultants' attitudes towards research fraud
Authors: Geggie D
Published: July 2002

Objective—To determine the prevalence of, and attitudes towards, observed and personal research misconduct among newly appointed medical consultants.

Design—Questionnaire study.

Setting—Mersey region, United Kingdom.

Participants—Medical consultants appointed between Jan 1995 and Jan 2000 in seven different hospital trusts (from lists provided by each hospital's personnel department).

Main outcome measures—Reported observed misconduct, reported past personal misconduct and reported possible future misconduct.

Results—One hundred and ninety-four replies were received (a response rate of 63.6%); 55.7% of respondents had observed some form of research misconduct; 5.7% of respondents admitted to past personal misconduct; 18% of respondents were either willing to commit or unsure about possible future research misconduct. Only 17% of the respondents reported having received any training in research ethics. Anaesthetists reported a lower incidence of observed research misconduct (33.3%) than the rest of the respondents (61.5%) (p<0.05).

Conclusion—There is a higher prevalence of observed and possible future misconduct among newly appointed consultants in the UK than in the comparable study of biomedical trainees in California. Although there is a need for more extensive studies, this survey suggests that there is a real and potential problem of research misconduct in the UK.
Exposure assessment in the hard metal manufacturing industry with special regard to tungsten and its compounds
Authors: Kraus T , Schramel P , Schaller K H , Zöbelein P , Weber A , Angerer J
Published: July 2002

OBJECTIVES

To assess the exposure to tungsten, cobalt, and nickel in a plant producing hard metals. The main components of hard metals are tungsten carbide and cobalt metal. According to recent studies, these two components may be responsible for both fibrogenic and carcinogenic effects.

METHODS

87 workers were investigated (86 male, one female) with a median age of 42 (range 22–58) and a mean duration of exposure of 13 years (range 1–27 years). Stationary and personal air sampling, and biological monitoring were carried out.

RESULTS

Ambient monitoring yielded maximum tungsten concentrations of 417 μg/m3in the production of heavy alloys. A maximum cobalt concentration of 343 μg/m3and a maximum nickel concentration of 30 μg/m3were found at the sintering workshop. The highest urinary cobalt concentrations were found in the powder processing department. The mean concentration was 28.5 μg/g creatinine and the maximum value was 228 μg/g creatinine. The maximum nickel concentration in urine of 6.3 μg/g creatinine was detected in the department producing heavy alloys. The highest tungsten concentrations excreted in urine were found in grinders and had a mean value of 94.4 μg/g creatinine and a maximum of 169 μg/g creatinine. Due to the different solubility and bioavailability of the substance, there was no correlation between the tungsten concentrations in air and urine on a group basis.

CONCLUSIONS

Despite its low solubility, tungsten carbide is bioavailable. The different bioavailability of tungsten metal and tungsten compounds has to be considered in the interpretation of ambient and biological monitoring data in the hard metal producing industry. The bioavailability increases in the order: tungsten metal, tungsten carbide, tungstenate. Only if both monitoring strategies are considered in combination can a valid and effective definition of high risk groups be derived.
Solvent use and time to pregnancy among female personnel in biomedical laboratories in Sweden
Authors: Wennborg H , Bodin L , Vainio H , Axelsson G
Published: July 2002

OBJECTIVES

To elucidate possible effects on fecundability from chemical, biological, and physical agents in laboratories, a retrospective study based on a questionnaire was conducted among female personnel who worked in Swedish biomedical research laboratories. Female personnel in non-laboratory departments were used as a reference group. The maximum number of women included in the analyses was 560. This corresponded to 2519 menstrual cycles. These women had given birth at least once during the period 1990–4.

METHODS

Time to pregnancy was used to estimate the fecundability—that is, probability of conception of a clinically detectable pregnancy per cycle. The fecundability ratio (FR) between exposed and unexposed cycles was calculated with a discrete time analogue of the Cox's proportional-hazards model. The FR estimates below unity indicate subfecundity.

RESULTS

Work with organic solvents in general in laboratory work, gave a decreased adjusted fecundability ratio (FR) of 0.79 (95% confidence interval (95 % CI) 0.68 to 0.93). Moreover, work with acetone and use of viruses also showed decreased FRs, 0.72 (0.53 to 0.97) and 0.66 (0.49 to 0.90), respectively.

CONCLUSIONS

The results of the present study give some indications of reduced fecundability for work with specific agents in laboratories, and support previously reported findings of a negative influence of organic solvents on fecundity among female laboratory personnel.
Immunological analysis of pleural fluid in post-cardiac injury syndrome
Authors: Shrivastava R , Venkatesh S , Pavlovich B B , Bharadwaj J , Vaz A
Published: July 2002

Post-cardiac injury syndrome (PCIS) is an inflammatory process involving pleura and pericardium secondary to cardiac injury. Even though this clinical entity has been recognised for decades, diagnosis is difficult because of lack of a diagnostic test. Antimyocardial antibody titre in pleural fluid and serum has been proposed to have diagnostic value. However there are inherent difficulties in measuring and interpreting the role of antimyocardial antibody. A case of PCIS with low pleural fluid complement level is reported, which it is believed can be useful to support the diagnosis of PCIS.
DNA polymorphism in the living fossil Ginkgo biloba from the Eastern United States
Authors: Kuddus Ruhul H , Kuddus Nayema N , Dvorchik Igor
Published: July 2002

Random amplified polymorphic DNA (RAPD) analysis is a valuable tool in studying inter- and intra-specific genetic variations, patterns of gene expression, and for the identification of specific genes using nearly isogenic variants. Here we used RAPD analysis to study the genetic variation in Ginkgo biloba grown in the eastern United States. Our results support the evidence that Southern blot hybridization of RAPD using probes made from cloned DNA fragments allows a more accurate analysis of the RAPD pattern than dye-stained gels or Southern blot hybridization of RAPD blots using probes made from purified PCR products. Using these techniques, we observed a high degree of relatedness among plants grown in certain localities although significant genetic variation may exist in the species, and could be a possible explanation for the observed variations in the efficacy of medications derived from G. biloba extract.Key words: Ginkgo biloba, Ginkgo extract, RAPD analysis, RFLP analysis.
Microsatellite marker analysis of an anther-derived potato family: skewed segregation and genecentromere mapping
Authors: Chani Eduard , Ashkenazi Varda , Hillel Jossi , Veilleux Richard E
Published: July 2002

Segregation patterns of polymorphic simple sequence repeat (SSR) primer pairs were investigated in monoploid potato families derived from anther culture. A total of 14 primers developed from the sequences in the database, as well as from a genomic library of potato, was used. Distorted segregation was observed for seven (50%) polymorphic loci among monoploids derived from an interspecific hybrid. Similar distortion was observed for only one of five loci that could be contrasted between the two monoploid families. Segregation distortion was less common in the sexually derived backcross population between the interspecific hybrid and either of its parents. One locus could be putatively linked to a lethal allele because it showed distorted segregation in both monoploid families, a group of 70 heterozygous diploids derived from unreduced gametes through anther culture, and a backcross population. These diploids were used to map the polymorphic SSR markers with respect to the centromeres using half-tetrad analysis. The majority of the SSR loci mapped more than 33 cM from the centromere, suggesting the occurrence of a single crossover per chromosome arm.Key words: androgenesis, segregation distortion, simple sequence repeats (SSRs), Solanum phureja, unreduced gametes.
Traitement et analyse des paramètres de pilotage d'un tunnelier
Authors: Denis Alain , Cremoux Francis
Published: July 2002

Tunnel boring parameters are used to control the good-functioning of the tunnel boring machine along the bored tunnel route and rarely to obtain more information about the nature or the mechanical behavior of the bored soil. Actually, they can bring very informative data, firstly, to improve the geological section to have the exact tunnel length in each soil formation and, secondly, to quantify the variability of the boring process along the tunnel route. Previously, a mechanical parameter is obtained from the combination of three tunnel boring parameters, which are thrust, penetration rate, and rotary speed. From statistical and geostatistical methods, the drillability signal, which can be seen as a time series, is divided into a set of stationary subdomains. The resulting series is then a stationary one, by zones, whose analysis can bring more information about the tunnel length for each soil formation and on the variability of the boring process. This last piece of information might then be utilized by contractors to explain some low advance rate totally unexpected before boring.Key words: tunnel boring machine, boring parameters, drillability, homogeneous zone, variability, statistic, geostatistic.
A field study of hoarfrost formation on insulated pavements
Authors: Côté J , Konrad J -M
Published: July 2002

This paper presents the results of a field study of hoarfrost formation on insulated test sections located in Québec City. It was established that the surface cooling rate increases sharply when all of the granular material placed above the insulating layer is frozen. The absence of latent heat release makes the pavement surface more sensitive to rapidly changing meteorological conditions. It was also shown that hoarfrost formation occurs when the surface temperature is less than the frost point, and it is not related to the dew point, as generally accepted. The paper also discusses the relationship between the hoarfrost index, HFI, and the total thickness of hoarfrost deposits.Key words: frost penetration, pavement, insulation, surface cooling, differential icing, hoarfrost.
Effect of protein binding on charge transfer in DNA: A simple model based on the superexchange mechanism
Authors: Filali-Mouhim Abdelali , Benrahmoune Mustapha , Jay-Gerin Jean-Paul
Published: July 2002

The effect of protein binding on the electronic coupling between distant redox centers in DNA is investigated in DNAprotein complex systems using the superexchange formalism. The systems (bridges) studied are described by a tight-binding electronic Hamiltonian in which site orbitals interact with one another through an exponentially decaying function of distance. Based on the "continuous-medium approximation," previously developed for large homogeneous three-dimensional systems (J.-M. Lopez-Castillo et al. J. Phys. Chem. 99, 6864 (1995)), the intervening bridge is defined by a unique dimensionless parameter Γ /E that controls the distance dependence of the electronic coupling. Here, E is the energy separation between the orbitals of the bridging medium and the redox sites (tunneling energy), and Γ is the electronic bandwidth of the bridge taken as a continuous medium. It was found that, for a given value of (Γ/E)DNAfar from the DNA's resonance conditions and for (Γ/E)proteinvalues near the protein's resonance conditions, the electronic coupling is independent of the donoracceptor distance when the acceptor lies within the "recognition region" of DNA. Moreover, when the redox centers are located on both sides of this region, the electronic coupling is many orders of magnitude larger than it should be, far from the protein's resonance conditions.Key words: DNA, DNAprotein complexes, long-range electron and hole transfers, electronic coupling, superexchange mechanism, energetic control, continuous-medium approximation.
Regulation ofRaoultella terrigenacomb.nov. phytase expression
Authors: Zamudio Marcela , González Aracely , Bastarrachea Fernando
Published: July 2002

Phytases catalyze the release of phosphate from phytate (myo-inositol hexakisphosphate) to inositol polyphosphates. Raoultella terrigena comb.nov. phytase activity is known to increase markedly after cells reach the stationary phase. In this study, phytase activity measurements made on single batch cultures indicated that specific enzyme activity was subject to catabolite repression. Cyclic AMP (cAMP) showed a positive effect in expression during exponential growth and a negative effect during stationary phase. RpoS exhibited the opposite effect during both growth phases; the induction to stationary phase decreased twofold in the rpoS::Tn10 mutant, but the effect of RpoS was not clearly determined. Two phy::MudI1734 mutants, MW49 and MW52, were isolated. These formed small colonies in comparison with the MW25 parent strain when plated on Luria-Bertani (LB) or LB supplemented with glucose. They did not grow in minimal media or under anaerobiosis, but did grow aerobically on LB and LB glucose at a lower rate than did MW25. The β-galactosidase activity level in these mutants increased three to four fold during stationary growth in LB glucose and during anaerobiosis. Addition of cAMP during the exponential growth of MW52 on LB glucose provoked a decrease in β-galactosidase activity during the stationary phase, confirming its negative effect on phytase expression during stationary growth.Key words: phytase activity, expression regulation, Raoultella terrigena.
UNIFORM CHARACTERIZATIONS OF COMPLEXITY CLASSES OF FUNCTIONS
Authors: KOSUB SVEN , SCHMITZ HEINZ , VOLLMER HERIBERT
Published: July 2002

We introduce a general framework for the definition of function classes. Our model, which is based on nondeterministic polynomial-time Turing transducers, allows uniform characterizations of FP, FP NP , FP NP [O ( log n)], [Formula: see text], counting classes (#·P, #·NP, #·coNP, GapP, GapP NP ), optimization classes (max·P, min·P, max·NP, min·NP), promise classes (NPSV, # few · P , c #· P ), multivalued classes (FewFP, NPMV), and many more. Each such class is defined in our model by a scheme how to evaluate computation trees of nondeterministic machines. We study a reducibility notion between such evaluation schemes, which leads to a necessary and sufficient criterion for relativizable inclusion between function classes. As it turns out, this criterion is easily applicable and we get as a consequence, e.g., that there is an oracle A, such that min · P A⊈#· NP A (note that no structural consequences are known to follow from the corresponding positive inclusion).