bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimation of Mediterranean forest transpiration and photosynthesis through the use of an ecosystem simulation model driven by remotely sensed data
Authors: Anselmi Silvia , Chiesi Marta , Giannini Monica , Manes Fausto , Maselli Fabio
Published: June 2004

Aim  This paper investigates the use of an ecosystem simulation model, FOREST‐BGC, to estimate the main ecophysiological processes (transpiration and photosynthesis) of Mediterranean coastal forest areas using remotely sensed data.

Location  Model testing was carried out at two protected forest sites in central Italy, one of which was covered by Turkey oak (Circeo National Park) and the other by holm‐oak (Castelporziano Estate).

Methods  At both sites, transpiration and photosynthesis measurements were collected in the field during the growing seasons over a four‐year period (1999 and 2001 for the Turkey oak; 1997, 1999 and 2000 for the holm‐oak). Calibration of the model was obtained through combining information derived from ground measurements and remotely sensed data. In particular, remote sensing estimates of the Leaf Area Index derived from 1 × 1‐km NOAA AVHRR Normalized Difference Vegetation Index data were used to improve the adaptation of the model to local forest conditions.

Results  The results indicated different strategies regarding water use efficiency, ‘water spending’ for Turkey oak and ‘water saving’ for holm‐oak. The water use efficiency for the holm‐oak was consistently higher than that for the Turkey oak and the relationship between VPD and WUE for the holm‐oak showed a higher coefficient of determination (R2 = 0.9238). Comparisons made between the field measurements of transpiration and photosynthesis and the model estimates showed that the integration procedure used for the deciduous oak forest was effective, but that there is a need for further studies regarding the sclerophyllous evergreen forest. In particular, for Turkey oak the simulations of transpiration yielded very good results, with errors lower than 0.3 mm H2O/day, while the simulation accuracy for photosynthesis was lower. In the case of holm‐oak, transpiration was markedly overestimated for all days considered, while the simulations of photosynthesis were very accurate.

Main conclusions  Overall, the approach offers interesting operational possibilities for the monitoring of Mediterranean forest ecosystems, particularly in view of the availability of new satellite sensors with a higher spatial and temporal resolution, which have been launched in recent years.
Defending “The Purity of Home Life” Against Socialism: The Founding Years of the Australian Women's National League
Authors: Quartly Marian
Published: June 2004

The paradigm of maternal citizenship has been variously understood by historians as enabling and restrictive of women's action in the public sphere. This paper considers the use to which the maternal paradigm was put by the founders of the Australian Women's National League, focussing in particular upon their campaign to link the Labor party with socialism and “free love”. It observes the ease with which the ideal of the maternal citizen — central to the liberal feminism of the day — could be turned to the conservative class interests of elite women.
Hostile Receptions: Dilemmas of Democracy, Legitimacy and Supranational Law
Authors: Longo Michael
Published: June 2004

The increasing resonance of international humanitarian law in the domestic sphere, primarily through the implementation of treaty obligations in domestic legislation, gives international law a relevance to local communities never before seen. Whilst the effects of this phenomenon defy generalisation in Australia today, it is possible to discern a range of responses from indignation at the overarching reach of international law to the domestic space, to vindication of historical claims of mistreatment at the hands of colonial oppressors.

Recent shifts in Commonwealth legislation and policy have sparked debate on whether the federal government has breached its international obligations. Notwithstanding the importance and currency of this question, and irrespective of one's views on it, there is a broader issue raised by the question, which is more amenable to academic investigation. It may be framed in the following terms. How can, and should, the ideal of democratic control of legislation and the legal system generally be reconciled with the development of an autonomous international legal system? The article will approach this question from a comparative perspective, drawing on legal and political developments in the EU and Australia. It seeks to justify a comparative analysis on the basis that Australia (an established federation) and the EU (an emerging federation) are both dealing with issues of reception of supranational law within domestic systems. It concludes that there is a need to reaffirm the legitimacy of supranational law both as an expression of national sovereignty and as an outcome of rational discourse — i.e. it has come into being with right process and is considered binding.
Disproportionate Sentences as Human Rights Violations
Authors: Van Zyl Smit Dirk , Ashworth Andrew
Published: June 2004

The article explores the concepts of disproportionality and gross disproportionality in sentencing. Several constitutions or human rights documents prohibit grossly disproportionate sentences, either expressly or impliedly. The draft constitution of the European Union has a Charter of Fundamental Rights that includes the right not to be subjected to a disproportionate sentence. The possible meaning and application of this are discussed by reference to the development of related constitutional jurisprudence in other jurisdictions.
Secondary Iatrogenic Harm: Claims for Psychiatric Damage Following a Death Caused by Medical Error
Authors: Case Paula
Published: June 2004

The purpose of this paper is to investigate the feasibility of claims for psychiatric damage following the death of a family member, where that death has been caused by medical error.1 The relative's position is a subject of heightened interest since the exposure of the plight of the parents involved in the UK organ scandal,2 and in the case of an iatrogenic death it is, of course, the family who are essentially the focus of the law's attempts to provide redress. Whilst the cases of deceased patients' relatives seeking damages for mental harm are inherently problematic in light of the restrictive secondary victim criteria applicable to psychiatric damage claims, a close look at the rules which permeate this area of compensation reveals that denying compensation to the relative suffering psychiatric harm is difficult to sustain.3
Transatlantic constitutionalism: Comparing the United States and the European Union
Authors: FABBRINI SERGIO
Published: June 2004

Abstract. This article contributes to the European constitutional debate with a comparison of the constitutional evolution of the European Union and the United States. The European Union has more to learn from the American experience of constitutionalism than from any of its own Member States. Like the United States, the European Union will have a frame of government constitution that will try to order a system of multiple and concurrent communities of interests, as happened in America, and designed by an indirectly elected assembly. The European Union and the United States will continue to manifest many differences in other crucial aspects of their institutional and cultural development. However, although constrained by their respective historical and institutional paths, their constitutional evolution is making the Atlantic Ocean less wide than it used to be.
The metamorphoses of corporatism: From classical to lean patterns
Authors: TRAXLER FRANZ
Published: June 2004

Abstract. Given notable fluctuations in the relevance of corporatist practices over time, did profound transformations in the profile of corporatism accompany these fluctuations? Based on data from twenty OECD countries, this article examines whether and how corporatist wage regulation changed its profile in structures, policies and performance from 1970 to 1996. The empirical evidence obtained from this analysis runs counter to the orthodox view of superior persistence and performance of classical (i.e., encompassing and centralized) structures of corporatism. Non‐classical (‘lean’) structures have gained in importance and performed no worse than their classical counterparts. The article concludes by discussing the implications of the findings for corporatist theory.
Basic Fibroblast Growth Factor Coating and Endothelial Cell Seeding of a Decellularized Heparin‐coated Vascular Graft
Authors: Conklin Brian S. , Wu Huakang , Lin Peter H. , Lumsden Alan B. , Chen Changyi
Published: June 2004

Abstract:  The objective of this study was to determine the effect of basic fibroblast growth factor (bFGF) coating on endothelial cell seeding and proliferation on a decellularized heparin coated vascular graft and to determine the retention of seeded cells on the graft under flow conditions. Disks of heparin coated decellularized grafts were incubated for 24 h as controls or with bFGF. Human microvascular endothelial cells (HMECs) or canine peripheral blood endothelial progenitor cells (CEPC) were seeded onto the disks and incubated for 96 h or 48 h, respectively. HMECs were also seeded onto the luminal surfaces of two heparin‐coated decellularized grafts for 3 h. One graft was placed in a perfusion culture system and cultured for an additional 6 h with flow and pressure. After culturing, there were 4.7 ± 1.4 cells/mm2 HMECs on control grafts and 11.4 ± 1.4 cells/mm2 in bFGF treated grafts (P < 0.05). Likewise, with CEPCs, there were 14.8 ± 4.8 cells/mm2 in control grafts and 33.3 ± 7.3 cells/mm2 in bFGF treated grafts. After only 3 h of cell attachment, 60% of HMECs were retained in the intact graft exposed flow relative to the static control graft, which is an acceptable level. These data demonstrate that bFGF coating on the heparin bound decellularized grafts significantly increases both HMEC and dog EPC proliferation and that seeded cells are stable under perfusion conditions.
New Blood Volume Monitoring Method for Hemodialysis: A‐V Pressure Gradient Measurement by Synchronized One‐point Reading
Authors: Oda Masami , Hokama Sanehiro , Sugaya Kimio , Hatano Tadashi , Ogawa Yoshihide
Published: June 2004

Abstract:  During hemodialysis, rapid ultrafiltration often causes symptomatic hypotension. To predict the occurrence of volume‐dependent hypotension as early as possible, continuous hematocrit monitoring with the Crit‐Line noninvasive monitor has been widely used to measure blood volume changes during hemodialysis. As another potential method of monitoring blood volume variations, we studied blood viscosity, which is theoretically associated with the pressure gradient across the dialyzer. Blood viscosity (calculated by the Hugen‐Poiseuille formula) is a major determinant of the blood flow rate and is associated with the pressure difference between the postpump arterial (A) and venous (V) pressures. The A‐V pressure gradient fluctuates due to pump pulsation, so we minimized this noise by always reading the pressure gradient at the same point out of 1400 partitions on the rotary pump. To test this synchronized one‐point reading method, the A‐V pressure gradient was measured using 3 different xanthan gum solutions and was found to be linearly proportional to the model blood flow rate. In an experimental dialysis system using a xanthan gum solution (300 mg/L), the A‐V pressure gradient showed a gradual linear increase along with the ultrafiltration rate up to 1 L/h as the viscosity slowly increased in the dialyzer. The changes of blood volume shown by this method were significantly correlated with data obtained using the Crit‐Line in 8 patients undergoing hemodialysis. This simple and inexpensive method may allow monitoring of blood volume changes and thus provide data that are beneficial for fluid management in hemodialysis patients suffering from clinical dialysis intolerance.
Assessment of Stenosis in Vascular Access Grafts
Authors: Tricht Ilse Van , Wachter Dirk De , Vanhercke Daniel , Tordoir Jan , Verdonck Pascal
Published: June 2004

Abstract:  The major complication that occurs with grafts used as vascular access for hemodialysis, is stenosis at the venous anastomosis or in the draining vein. 75% area stenosis is considered significant as thrombotic occlusion may occur. The aim of this experimental study was to evaluate invasive and noninvasive indices to detect significant stenoses in a vascular access graft. A compliant underarm loop graft in vitro model was built and studied with 50, 65, 80, and 90% stenosis at flow rates of 500, 1000, and 1500 mL/min. Flow in the system was pulsatile. Velocity was measured with ultrasound Doppler and the pressure was measured invasively. The  resistance  index  (RI), pvenous line/MAP, and the newly introduced pressure ratio (PR) were calculated and compared. A stenosis can be suspected when a high frequency ultrasound velocity signal develops at the venous anastomosis. RI > 1 confirms a very severe stenosis (90%). The parameter PR < 8% confirms significant stenoses showing its clinical relevancy.
Ulnar‐basilic Fistula: Indications, Surgical Aspects, Puncture Technique, and Results
Authors: Salgado Octavio J. , Chacón Rosa E. , Henríquez Carlos
Published: June 2004

Abstract:  Ulnar‐basilic fistula (UBF) is an autogenic vascular access option for hemodialysis (HD) first reported in 1967. However, only a few reports dealing with its complications and survival rates have been published in the literature. In the present work the results of 61 UBFs done in 60 adult patients on chronic HD are reported. Forty UBFs were created as primary access and the remaining 21 UBF as secondary access after: (a) thrombosis of an ipsilateral radiocephalic fistula (RCF) in 6 cases, (b) thrombosis of a contralateral RCF in 7 cases, and (c) thrombosis of a brachiocephalic fistula in 2 cases. No episodes of surgical complications, arterial steal, or ulnar nerve damage were observed. Five UBFs thrombosed within the first week after surgery. The 1‐, 3‐, and 5‐year unassisted survival rates were 70.9%, 67.7%, and 57.3%, respectively, which were significantly higher than those reported previously. The inclusion of UBF in routine access plans is recommended.
Computational Fluid Dynamics‐Analysis of the Niagara Hemodialysis Catheter in a Right Heart Model
Authors: Mareels Guy , De Wachter Dirk S. , Verdonck Pascal R.
Published: June 2004

Abstract:  Central venous catheters are widely used as a hemoaccess method for dialysis therapy. In this study, the performance parameters (velocities, pressure drop, shear rates, access recirculation) of the Niagara catheter are analyzed using computational fluid dynamics. Side holes are left open, closed, or reduced in size to assess the influence of this design feature. Initially the catheter is inserted in a tube which represents the vena cava. In the “arterial” luminal tip, wall shear rates over 20 000 s−1 are common and peaks attain 55 000 s−1 at a 300 mL/min blood flow rate. The presence of side holes appears to affect the location but not the level of these elevated shear rates. Halving their diameter causes elevated shear rates to appear in a more extended region with peaks up to 80 000 s−1. Simulated recirculation percentage is nil in normal catheter use, but attains 30% with reversed catheter connections. The  results  of  the  tube  model  are  compared  to  those  of an anatomically realistic right atrium model, which was three‐dimensionally reconstructed. It is concluded that most catheter's specific hemodynamic properties can be deduced from the tube model.
Prediction of the Clinical Performance of Adult Arterial Cannulas
Authors: De Somer Filip , Taeymans Yves , De Wachter Dirk , Verdonck Pascal , Van Nooten Guido
Published: June 2004

Abstract:  The choice of an arterial cannula for cardiac surgery is often difficult. The clinician has to rely on the pressure–flow diagrams provided by the manufacturer that are all produced using water. The conversion of these water data to representative clinical conditions is often difficult if not impossible. In this in vivo study the theory of dynamic similarity is applied to scale the manufacturer's data to the clinical situation, in order to predict the pressure drop desired by the cardiac surgeon. Three hundred and forty‐seven samples of pressure drop are obtained in 58 patients. Patients are grouped according to cannula size (20, 22, and 24 Fr). Very good correlation is found between measured and predicted values (r = 0.93; 0.86; 0.87 for 20; 22; 24 Fr). As a result, windows of optimal performance are constructed for each cannula diameter. This technique also allows the construction of an online recommendation for signaling abnormal cannula performance during cardiac surgery.
Does the Family Business Interaction Factor Represent a Resource or a Cost?
Authors: Poza Ernesto J. , Hanlon Susan , Kishida Reiko
Published: June 2004

The authors investigate the interaction between families and their businesses and the impact of this interaction on management and governance practices used. Family businesses participating in the family business programs at three U.S. universities completed questionnaires pertaining to family and business culture and practices. The research draws on the agency cost theory, governance, systems theory, and the resource-based view of organizations literature in the consideration of family firm attributes and the relationship between family members, nonfamily managers, and the firm. Chief executive officers generally perceive management practices, succession processes, and family environment more favorably than do either other family members or nonfamily managers. There are no significant differences in perceptions between active and inactive family members on the family scales. The difference in perceptions of the family firm between nonfamily managers and family managers is discussed as a challenge to the full utilization of professional management capabilities by family firms. Finally, owning family unity, the perception of business opportunity, and how positive the relation between firm and family is influences managerial and governance practices and therefore represents a resource for competitive advantage and sustained business performance.
The Family Business and Its Social Responsibilities
Authors: Gallo M.A.
Published: June 2004

The social responsibilities of family businesses are still a little-studied area. This article is based on the opinions of 44 academics who are directly involved in studying and advising this type of company. The study's results indicate that family businesses are better at carrying out the responsibilities of wealth creation and delivery of goods to the market than the development of individual skills and guaranteeing their long-term continuity.
Study of the Interconversion of Isomers of [16]annulene by the AM1 Method
Authors: Hernando José María , Quirante José Joaquín , Enríquez Fernando
Published: June 2004

The AM1 method was used to carry out a theoretical study of different isomers of [16]annulene and of the reversible transformation between them preserving the molecular periphery. Transition states were located on the corresponding potential energy hypersurface.
Theoretical Interpretation of High-Performance Chromatographic Data for a Heterogeneous Series of Compounds
Authors: Jakuš Vladimír
Published: June 2004

A new approach to theoretical evaluation of the Gibbs free energy of solvation was applied for estimation of retention data in high-performance liquid chromatography on reversed phases (RP-HPLC). Simple and improved models of stationary and mobile phases in RP-HPLC were employed. Statistically significant correlations between the calculated and experimental data were obtained for a heterogeneous series of twelve compounds.
The Ion Associates of Methyl-, Ethyl- and Isopropyl Derivatives of Dialkylaminoethyl Dialkylamidofluorophosphate with Bromophenol Blue
Authors: Halámek Emil , Kobliha Zbyněk
Published: June 2004

Nine new Tammelin esters were studied on the basis of the chloroform extracts of their ion associates with bromophenol blue. A study was made of the effect of the alkyl on the amino and amido groups of dialkylaminoethyl dialkylamidofluorophosphate and on the extraction efficiency of the ion pair. An increase in the number of carbon atoms on the amide group leads to the increase in the extraction efficiency of the ion pairs as a consequence of the increasing hydrophobicity. A further contribution to the increase in the extraction efficiency with increasing number of carbon atoms in the alkyls of the amino nitrogen is clearly retarded by the increasing basicity of the amino group. An extraction spectrophotometric determination of the test derivatives of dialkylaminoethyl dialkylamidofluorophosphate was developed and the interferences from precursors in the synthesis were examined.
Nickel(II) Complexes with 1,3,6,9,11,14-Hexaazatricyclo-(12,2,1,1)octadecane. Structure and Some Properties
Authors: Březina František , Šubčíková Martina , Kameníček Jiří , Lasovský Jan , Šindelář Zdeněk , Pastorek Richard , Ondráček Jan
Published: June 2004

The following compounds have been prepared: [NiL]Cl2.3 H2O, [NiL]Br2.3 H2O, [NiL]I2.H2O and [NiL](NO3)2.H2O, where L is the title macroligand. The structure of [NiL]I2.H2O was solved by direct methods with the results: a = 8.399(3), b = 14.501(2), c = 15.699(2) Å, α = 86.64(1)°, β = 87.46(3)°, γ = 89.01(2)°. The substance crystallizes in the triclinic system with space group P I, Z = 4, R = 0.0589, wR = 0.0626. The arrangement around the nickel atom is approximatively square planar. Cyclic voltammetry demonstrated the possibility of oxidizing the nickel (II) complex and the diamagnetic sulphate [NiL](SO4)2 was prepared by the reaction of [NiL]Cl2.3 H2O with Na2S2O8.
Linear Tri- and Tetrapeptides Acting as Prodrugs
Authors: Kasafírek Evžen , Šturc Antonín , Roubalová Alena
Published: June 2004

Tri- and tetrapeptides with C-terminal 1-amino-1-cycloalkanecarboxylic acid of the general formula X-Ala-Y-OR, where X is Ala, Leu, Phe, Ac-Tyr, Gly-Pro, Ac-Leu-Lys or Ac-Leu-Arg, Y is Acb, Acp or Ach, and R is methyl or ethyl, have been prepared. These peptides containing a rationally chosen N-substituent are cleaved with a suitable enzyme (leucinaminopeptidase, alaninaminopeptidase, chymotrypsin, plasmin or kallikrein) in an aqueous medium. The arising C-terminal dipeptide ester undergoes spontaneous cyclization to give biologically active spirocyclic dipeptide. The prepared short peptides exhibit all functional features of prodrugs.
Substituted N,N-Dimethyl-3-(phenylthio)- and -4-(phenylthio)benzylamines
Authors: Šindelář Karel , Kmoníček Vojtěch , Hrubantová Marta , Polívka Zdeněk
Published: June 2004

(Arylthio)benzoic acids IIa - IIe and VIb - VId were transformed via the acid chlorides to the N,N-dimethylamides which were reduced either with diborane "in situ" or with lithium aluminium hydride to N,N-dimethyl-(arylthio)benzylamines Ia - Ie and Vb - Vd. Leuckart reaction of the aldehydes IX and X with dimethylformamide and formic acid afforded directly the amines Va and Ve. Demethylation of the methoxy compounds Ia and Ve with hydrobromic acid resulted in the phenolic amines If and Vf. The most interesting N,N-dimethyl-4-(phenylthio)benzylamine (Va) hydrochloride showed affinity to cholinergic and 5-HT2 serotonin receptors in the rat brain and some properties considered indicative of antidepressant activity (inhibition of serotonin re-uptake in the brain and potentiation of yohimbine toxicity in mice).
Preparation of Some Substituted 9,10-Dihydro-1-hydroxy-9-oxoacridine Derivatives
Authors: Rádl Stanislav , Kovářová Lenka
Published: June 2004

In connection with our research into antibacterial fluoroquinolones of a general formula I we were interested in similar 1-hydroxy-acridines II. Our synthetic strategy was based on a recent finding that ethyl 2-(1,4-dihydro-4-oxoquinolin-2-yl) acetate reacted at 180 °C with diethyl ethoxymethylene-malonate providing diethyl 9,10-dihydro-1-hydroxy-9-oxoacridine-2,4-dicarboxylate.
Preparation of Some 2,3-Dihydro-7-oxo-7H-pyrido[1,2,3-de][1,4]benzoxazine Derivatives
Authors: Rádl Stanislav , Moural Jaroslav , Bendová Radoslava
Published: June 2004

We have recently described a new reaction of 8-hydroxyquinolone II with 3-bromopropyne leading to 2,3-dihydro-3-methylene-7-oxo-7H-pyridol[1,2,3-de][1,4]benzoxazine-6-carboxylate IIIa, which could be used as an intermediate for preparation of antibacterically active compound IIIb. Now we extend the scope of the reaction.
The Interaction of Azure B with Surfactants
Authors: Němcová Irena , Dušková Martina
Published: June 2004

A study was made of the effect of anionogenic, cationogenic and nonionogenic surfactants (tensides) on the absorption spectra of azure B. It was found that the change in the absorption spectra in solutions containing sodium lauryl sulfate are produced by change in the polymerization of the dye. At low tenside concentrations, dimers and higher dye aggregates are formed as a result of a decrease in the dye cation repulsion caused by interaction with tenside monomer anions. Above the critical micelle concentration, the dye is solubilized in the micelles, where the monomer form of azure B predominates. The cationogenic tenside does not affect dye polymerization; monomer formation is preferred in the nonionogenic tenside after micelle formation.
The Determination of Optimal Inoculum Quality for Submerse Fermentation Process
Authors: Ettler Petr
Published: June 2004

The quantity and quality of inoculation material play a crucial role in bioprocess results. Instead of inexact decrease of pH value and subjective evaluation of the inoculum maturation, we proposed for the Streptomyces noursei cultivation to determine the rheological behaviour of the broth reflecting the growth of the culture and his physiological activity. For the rotational system cylinder-cylinder we found the optimal level of shear stress 80-120 mPa at shear rate 698 s-1 for the transfer of inoculum to production stage and achievement of maximal process productivity.
Structure of the Tris(diallyldithiocarbamate)cobalt(III) Complex
Authors: Kellö Eleonóra , Lokaj Jan , Vrábel Viktor
Published: June 2004

The structure of [Co{S2CN(CH2-CH=CH2)2}3] was determined by the heavy atom method, all nonhydrogen atoms being refined by anisotropic diagonal approximation using the least squares method to the value of R= 0.067 for 1 024 reflections with I ≥ 1.96σ(I). The substance is isostructural with [Fe{S2CN(CH2-CH=CH2)2}3], crystallizes in the monoclinic system, space group C2/c, lattice parameters a = 1.8763(9), b = 1.0209(5), c = 1.5402(7) nm, β = 106.18(4)°, Z = 4. Cobalt is coordinated by 3 dithiocarbamate ligands in the bidentate way, the average Co-S lenght is 0.2267(2) nm. The metal atom and two ligand atoms are located on the twofold axis. The CoS6 polyhedron is a trigonally distorted octahedron.
Resolution of a Racemic Corey Lactone via Enantioselective Esterification
Authors: Veselý Ivan , Paleček Jaroslav , Stibor Ivan
Published: June 2004

The (-)-enantiomer of Corey lactone Ia has been separated from its (+)-enantiomer Ib via enantioselective esterification of the latter using glycerol tributyrate and catalytic amount of lipase from Candida cylindracea (EC 3.1.1.3) in an aprotic solvent at 20 to 40 °C during 5 to 48 h. The Ic obtained has been separated from Ia by column chromatography and converted back to Ib by acid catalyzed transesterification with methanol.
The Synthetic Use of 2-(4'-Acetylbiphenyl-4-yl)-5-phenyl-1,3,4-oxadiazole for Preparation of New Heterocyclic Luminophores
Authors: Lhoták Pavel , Kurfürst Antonín , Nádeník Petr
Published: June 2004

2-(4'-Acetylbiphenyl-4-yl)-5-phenyl-1,3,4-oxadiazole (I) was converted into α,β-unsaturated ketone II and pyridinium salt IV, which were used in preparation of triarylpyridines XIII-XIX by Kröhnke's method. Also the diketones V-VIII were obtained from derivative I and served as precursors for the synthesis of pyrazoles IX-XII. The discussion of 1H NMR spectra and luminescent properties of prepared bifluorophoric heterocyclic systems is given.
Synthesis of trans-2-[N-(2-Hydroxy-1,2,3,4-tetrahydronaphthalene-1-yl)]iminothiazolidine and Related Compounds - A New Class of Antidepressants
Authors: Shukla Upendra K. , Singh Raieshwar , Khanna J. M. , Saxena Anil K. , Singh Hemant K. , Sur Ravindra N. , Dhawan Bhola N. , Anand Nitya
Published: June 2004

Antiparasitic and antidepressant activities exhibited by tetramisole (I) and its enantiomers prompted the study of its structural analogs trans-2-[N-(2-hydroxy-1,2,3,4-tetrahydronaphthalene/indane-1-yl)]iminothiazolidine (VIII/IX) and 2,3,4a,5,6,10b-hexahydronaphtho[1',2':4,5]-imidazo[2,1-b]thiazole (XII), 2,3,4a,5-tetrahydro-9bH-indeno[1',2':4,5]imidazo[2,1-b]thiazole (XIII), and 2,3,4a,5-tetrahydro-9bH-indeno[1',2':4,5]imidazo[2,1-b]thiazole (XVI), and a homolog 3,4,6,7-tetrahydro-7-phenyl-2H-imidazo[2,1-b]-1,3-thiazine (XX). While none of these compounds showed any noteworthy antiparasitic activity, the trans-2-[N-(2-hydroxy-1,2,3,4-tetrahydronaphthalene-1-yl)]iminothiazolidine (VIII) has shown marked antidepressant activity, better than imipramine in the tests used, and provides a new structural lead for antidepressants.
The Effect of Dephosphorylation on the Conformation of Peptides from β-Casein
Authors: Clark David C. , Smith Linda J. , Chaplin Lesley C.
Published: June 2004

Peptides β(1-28) and β(1-52) incorporating residues 1-28 and 1-52 of β-casein were prepared by proteolysis of the protein using plasmin and chymotrypsin respectively. Analysis of the circular dichroism spectra of the isolated peptides revealed that limited levels of α-helix were formed only by peptide β(1-52) and then only in the presence of >40% trifluoroethanol (TFE). Partial dephosphorylation of the peptides by treatment with alkaline phosphatase resulted in the formation of significant levels of α-helix in both peptides in the presence of TFE. However, no α-helix was detected in either peptide in the absence of TFE.
Polarographic and Voltammetric Determination of Chlorobenzene, Benzyl Chloride and Melphalan
Authors: Barek Jiří , Matějka Jaroslav , Zima Jiří
Published: June 2004

Conditions were found for the determination of chlorobenzene and benzyl chloride in dimethylformamide and of Melphalan in ethanol-water medium (4 : 1) using tast polarography at a classical dropping mercury electrode in the concentration range 1 . 10-3 - 2 . 10-5 mol l-1. Differential pulse polarography permits the range for the determination of benzyl chloride to be extended to 1 . 10-5 - 2 . 10-6 mol l-1. The use of fast scan differential pulse voltammetry and linear scan voltammetry at a hanging mercury drop electrode did not lead to an increase in the sensitivity of the determination because of the very negative half-wave potential values and high irreversibility of the processes involved.
Polymer-Supported Oligo(oxyethylene)s, Sulfoxides, and Crown Ethers in Nucleophilic Substitution Reactions
Authors: Čefelín Pavel , Hrudková Hana , Janout Václav , Kalchenko Vitalii I. , Valter Bohumír
Published: June 2004

The efficiency of polymer analogues of oligo(oxyethylene)s and sulfoxides in the activation of nucleophilic substitution reactions were compared by testing to the reaction between sodium phenoxide and 1-bromooctane in 1,4-dioxane. With polymer analogues of crown ethers and polymer networks having the pseudo-crown ether structure the polymer effect can be achieved, i.e. a higher activation efficiency of the polymer analogue (in the L-S system) compared with the efficiency of the unimmobilized compound (in the homogeneous system). The results suggest that several molecules of the linear activator or of side active groupings (chains) on the polymer having the podand structure take part in the formation of the activation site (for the complex formation or solvation of the cation).
Carbon-13 Substituent-Induced Chemical Shifts: Monosubstituted Benzene Derivatives
Authors: Exner Otto , Buděšínský Miloš
Published: June 2004

Carbon-13 NMR spectra of twelve monosubstituted benzene derivatives were measured in deuterochloroform. Together with the literature data a set of 35 systematically chosen substituents was obtained on which some thirty correlation equations were tested. As anticipated only substituent chemical shifts (SCS) in the position 4 are controlled by inductive and resonance effects, and can be correlated by dual substituent parameters (DSP). For the other positions DSP were not successful and more sophisticated equations are not much telling. On the other hand, the direct relations between two series of SCS are usually more precise and simple to understand. It is concluded that SCS in benzene ring need not be controlled by too complex mechanism but simply by different factors than by inductive and resonance effects.
"Safety-Catch" Protecting Groups in Peptide Synthesis
Authors: Pátek Marcel , Lebl Michal
Published: June 2004

A new benzhydryl-type protective groups for amides based on the concept of converting a stable protecting group into a labile one (safety-catch principle) are described. The p-substituted benzhydrylamine derivatives III(a, b), IV(a, b) are shown to be labile toward various acids but in their oxidized state - V(a, b), VI(a, b) exhibit the resistance to conditions commonly used for removal the Boc group. Independent removal of Boc or Fmoc groups, each in the presence of derivative VIa, is demonstrated by a synthesis of Pro-Leu-Gly-NH2. Some mechanistic aspects of deprotection reaction are discussed.
4-N-Benzazolylamino Derivatives of 3-Y-3-Buten-2-one
Authors: Milata Viktor , Ilavský Dušan , Goljer Igor , Leško Ján
Published: June 2004

Ethoxymethylene derivatives of 2,4-pentanedione (Ia), 3-oxobutanenitrile (Ib), methyl (Ic) or ethyl (Id) 3-oxobutanoate give with 4- or 5-aminobenzimidazole or benzotriazole, respectively, under mild conditions products of nucleophilic substitution II-V. Structure of these compounds was discussed on the basis of their spectral measurements - IR, UV, 1H, 13C NMR and mass spectra.
Synthesis of O-(2-Deoxy-2-stearoylamino-β-D-glucopyranosyl)-(1→4)-N-acetylnormuramoyl-L-α-aminobutanoyl-D-isoglutamine, a Lipophilic Disaccharide Analogue of MDP
Authors: Ledvina Miroslav , Šaman David , Ježek Jan
Published: June 2004

Partial N-deacetylation of compound II with barium hydroxide afforded benzyl 2-acetamido-3-O-allyl-4-O-(2-amino-2-deoxy-4,6-O-isopropylidene-β-D-glucopyranosyl)-6-O,-benzyl-2-deoxy-α-D-glucopyranoside (III) in high yield. Compound III was N-acylated with stearic acid in the presence of DCC and the obtained product was converted into benzyl 2-acetamido-6-O-benzyl-3-O-carboxymethyl-2-deoxy-4-O-(3,4,6-tri-O-benzyl-2-deoxy-2-stearoylamino-β-D-glucopyranosyl)-α-D-glucopyranoside (VII). Coupling of compound VII with L-α-aminobutanoyl-D-isoglutamine benzyl ester followed by hydrogenolysis of the product VIII afforded compound IX.
Micellar Enzymology: Superactivity of Enzymes in Reversed Micelles of Surfactants Solvated by Water/Organic Cosolvent Mixtures
Authors: Klyachko Natalia L. , Bogdanova Natalia G. , Levashov Andrei V. , Martinek Karel
Published: June 2004

Catalytic properties of α-chymotrypsin, peroxidase and laccase, dissolved in water-immiscible organic solvents by entrapping them into the reversed micelles of surfactants solvated by water/organic cosolvent (glycerol or 1,4- or 2,3-butanediol or dimethyl sulfoxide) mixtures, are studied. As micelle-forming surfactants, sodium salt of bis(2-ethylhexyl)sulfosuccinate (Aerosol OT) in n-octane or cetyltrimethylammonium bromide in n-octane/chloroform (1 : 1 by volume) mixture are used. The dependences of the catalytic activity on the surfactant solvation degree are bell-shaped. Maxima of the catalytic activity of enzymes solubilized in the micellar systems are observed at such optimum values of the surfactant solvation degree at which the size of micellar inner cavity and of the entrapped protein molecule is approximately equal. With decreasing content of water in the micellar media studied, the catalytic activity of the solubilized enzymes increases considerably, and is much (10-100 times) higher than in bulk aqueous buffers. In conclusion, possible mechanisms of the micellar effects are suggested.
Molecular Mechanics Studies on MFI Type Zeolites. 1. Effect of p-Xylene Adsorption on the Zeolite Structure
Authors: Vos Burchart Erik de , Linden Bert van der , Bekkum Herman van , Graaf Bastiaan van de
Published: June 2004

The effect of the adsorption of p-xylene on the all-silica MFI-structure is simulated with our molecular mechanics model. From experimental measurements it is known that the symmetry of the framework changes from monoclinic (space group P21/n.1.1.) towards orthorhombic (space group P212121) upon adsorption of p-xylene up to eight molecules per unit cell. The experimentally observed change in the geometry of the zeolite upon p-xylene adsorption is compared with that calculated by molecular mechanics. For the calculations our force field for all-silica zeolites is used in combination with the MM3 force field for organic molecules. Parameters for the organic-zeolite interactions are obtained by combination of the two force fields.
Molecular Mechanics Studies on MFI Type Zeolites. 2. Isomorphous Substitution by Aluminium
Authors: Vos Burchart Erik de , Bekkum Herman van , Graaf Bastiaan van de
Published: June 2004

The molecular mechanics force field developed for all-silica structures is extended with parameters for tetrahedral aluminium. With this force field and the MM3 force field for organic molecules the effects of isomorphous substitution in the MFI framework are examined (4 Al/unit cell) with tetrapropyl ammonium (TPA) as the charge compensating cation. The results indicate a slight preference for the positions 2, 9, 5, 12, and 6 and the by mirror symmetry related positions. The differences in energy are mainly due to the differences in the zeolite framework energy.
Zeolite Syntheses from Superalkaline Reaction Mixtures
Authors: Fischer Falk , Hadan Marianne , Fiedrich Günter
Published: June 2004

The synthesis of faujasite-type zeolite from superalkaline reaction mixtures are described. The contribution shows the influence of component K2O added in the system Na2O-Al2O3-SiO2-H2O with H2O/(K2O + Na2O) = 13-15. The reaction course was investigated in the range K2O/(K2O + Na2O) from about 0.07 to 0.5. Under used conditions it is quite possible to isolate faujasite-type zeolite as a single crystalline phase. By means of IR spectroscopy, low SiO2/Al2O3 ratios from 2.0 to 2.1 in the faujasite framework have been indicated. The low SiO2/Al2O3 ratios are interpreted by a higher stability of the Si-O-Al- than the Si-O-Si- bond with increasing hydroxyl ion concentration.
Synthesis and Characterization of Novel Inorganic Microporous Beryllophosphates
Authors: Yu Long , Pang Wenqin
Published: June 2004

Five new types of microporous beryllophosphates were hydrothermally synthesized using BeO-P2O5-R-MCl (or MCl2)-H2O, R being cyclohexylamine (CHA), pyrrolidine, 1-butylamine or triethylamine, M alkali or alkali earth cation. X-Ray diffraction patterns (XRD), infrared (IR), TG-DT and elemental analysis show that the crystalline beryllophosphates have novel, unique framework structures, composed from basic units of tetrahedral PO4 and BeO4. These materials exhibit zeolite-like adsorption and ion-exchange properties. Factors affecting the product crystallization (as e.g. pH), type of cation and composition of reaction mixture are discussed.
Influence of Silicon Content and Nature of the Template Molecule on Physico-Chemical and Catalytic Properties of SAPO-5
Authors: Jänchen Jochen , Penchev Vladimir , Löffler Elke , Parlitz Barbara , Stach Helmut
Published: June 2004

Two series of SAPO-5 molecular sieves were synthesized: (i) Using tripropylamine as a template and varying the Si content in the gel, and (ii) varying the template molecule at constant silicon content in the gel. The products were characterized physico-chemically and tested in toluene disproportionation. It was found that the rising silica content in the synthesis gel has only little influence on the SiO2 incorporation into the SAPO. Investigation of the acid character revealed that the concentrations of the adsorbed ammonia molecules are nearly constant and independent of the total silicon content of the crystals. The catalytic activity showed no correlation either with the silicon content of the catalysts or with the acidity measured by temperature-programmed desorption of ammonia. It is concluded that the incorporated silicon exists not only in a monomeric form and that the TPD of ammonia reflects not only the strong Bronsted acidity. The SAPO-5 sample synthesized with triethylamine possessed the strongest acidity corresponding to the highest catalytic activity. It is supposed that in the presence of TEA molecules silicon replaces mainly P atoms in the AlPO4-5 framework.
The Shape-Selective Acylation of 2-Methoxynaphthalene, Catalyzed by Zeolites Y, Beta and ZSM-12
Authors: Harvey Gillian , Mäder Georg
Published: June 2004

The Friedel-Crafts acylation of 2-methoxynaphthalene (2MN) was investigated using zeolites USY, Beta and ZSM-12 as catalysts under batch conditions at 100 and 180 °C. Two ketone isomers, 1-acetyl-2-methoxynaphthalene (1AC) and 2-acetyl-6-methoxynaphthalene (2AC) were produced; the selectivity of the reaction could be influenced by the zeolite used. USY produced only the 1AC isomer whereas Beta and ZSM-12 produced both. Selective synthesis of 2AC was achieved by optimization of the reaction conditions using zeolite Beta as the catalyst. It was also observed that the 1AC ketone is unstable in contact with acid zeolite catalysts and undergoes protiodeacylation, a reaction previously only observed in the presence of strong mineral acids.
Shape Selective Disproportionation of Methylnaphthalene on ZSM-5 Catalyst
Authors: Kikuchi Eiichi , Mogi Yasuhiro , Matsuda Takeshi
Published: June 2004

The conversion of 2-methylnaphthalene (2-MN) was studied at atmospheric pressure in a flow-type fixed bed reactor using H-Y, H-beta, H-mordenite, H-ZSM-5, H-ZSM-11 and H-ZSM-48 as catalysts. H-Y and H-beta exhibited high activities for disproportionation and isomerization of 2-MN. H-Mordenite and zeolites having medium size pores were active for the conversion of 2-MN which was mainly isomerized to 1-MN. The low disproportionation activities of these zeolites resulted from their shape selective properties. Disproportionation of 2-MN on the zeolite catalysts gave 2,6- and 2,7-dimethylnaphthalenes (DMN) in higher proportions than the thermodynamically attainable level. H-ZSM-5 was the most selective catalyst to produce these DMN isomers among the zeolite catalysts tested, although 2,7-DMN was formed in a higher proportion than 2,6-DMN. On H-mordenite catalyst, 2,6-DMN was more selectively formed than 2,7-DMN. The selectivity for 2,6-DMN against 2,7-DMN increased with increasing SiO2/Al2O3 ratio of H-mordenite. It is suggested that the composition of DMN isomers produced by disproportionation of 2-MN depends on the acid strength as well as on the shape selective properties of zeolites used.
Diffusion Coefficients of Transition Metal Ion Complexes in Zeolites NaA, CaA, NaX
Authors: Vlessidis Athanasios G. , Evmiridis Nicholaos P.
Published: June 2004

Ion-exchange rate curves of aqueous and ammonia transition metal ion complexes are presented together with ion-exchange isotherms of the corresponding complexes using molecular sieves as ion-exchangers. The data are treated mathematically according to Danes and Wolf procedure and the diffusion coefficients for the specific transition metal ion complexes are obtained. Finally, the variation of diffusion coefficients with the extent of ion exchange is followed.
Fused Furazans
Authors: Śliwa Wanda , Thomas Antoni , Zelichowicz Natalia
Published: June 2004

As a continuation of our work concerning 1,2,5-heteradiazoles, the present paper deals with fused furazans - their syntheses, chemical reactivity and properties.
The Synthesis and Identification of Isomeric Products of Enzymatic O-Demethylation of the Sympathomimetic Tetraminol - trans-3(2-Hydroxyethylamino)-5,8-dimethoxy-1,2,3,4-tetrahydro-2-naphthol
Authors: Drandarov Konstantin
Published: June 2004

The structure of the positional isomers of mono-O-demethylated metabolites (V and VI) of Tetraminol - trans-3-(2-hydroxyethylamino)-5,8-dimethoxy-1,2,3,4-tetrahydro-2-naphthol (XIX) - and the pairs of related derivatives was determined.
Temperature Dependence of Densities and Heat Capacities for the Methanol-Urea System
Authors: Svoboda Václav
Published: June 2004

Data were obtained for the temperature dependences of densities and heat capacities of liquid solutions of the methanol-urea system over the region of their mutual solubility. The temperature region was 298.15 K to 328.15 K.
Extraction Spectrophotometric Determination of [(2-Chlorophenyl)methylene]propane Dinitrile with Reactive Dyes of the Stabilized Diazonium Salt Type
Authors: Halámek Emil , Kobliha Zbyněk
Published: June 2004

A spectrophotometric method has been developed for the determination of [(2-chlorophenyl)methylene]propane dinitrile (CS) stabilized by the diazonium salts Fast Red TR and Fast Blue B after extraction with chloroform. Mass spectrometry, 1H and 13C NMR and elemental analysis confirmed the presence of the hydrazoform of the azo dye formed by reaction with malononitrile, as a product of the alkaline hydrolysis of substance CS, and the diazonium salt Fast Red TR.
The Polarographic and Voltammetric Determination of 1(4'-Carbamoylphenyl)-3,3-dimethyltriazene
Authors: Barek Jiří , Mejstřík Viktor , Toubar Saafa , Zima Jiří
Published: June 2004

A study was made of the polarographic behaviour of 1-(4'-carbamoylphenyl)-3,3-dimethyltriazene and optimum conditions were found for its determination by tast polarography and differential pulse polarography at a static mercury drop electrode and by fast scan differential pulse voltammetry at a hanging mercury drop electrode in the concentration range 1 . 10-4 to 2 . 10-7 mol l-1. A further increase in the sensitivity can be achieved through adsorptive accumulation of the test substance on the surface of a hanging mercury drop, permitting the determination to be extended to the concentration range 1 . 10-7 - 2 . 10-9 mol l-1.
Some Problems of the Laboratory Modelling of Non-Isothermal Adsorption in a Fixed Bed of Adsorbent
Authors: Bobok Daniel , Kossaczký Elemír
Published: June 2004

The course of non-isothermal adsorption of carbon dioxide from nitrogen stream in laboratory glass adsorbers with a polyurethane insulation, without insulation, with a vacuum silvered jacket and with a vacuum jacket with radiation curtain of aluminium sheet was investigated from the point of view of the possibility to employ a one-dimensional model to describe the adsorption course. The assumptions of the one-dimensional model are fulfilled, from the adsorbers investigated, by the adsorber with vacuum silvered jacket and the adsorber with vacuum jacket with radiation curtain.
Ten-Vertex Monocarbaborane Chemistry. A Convenient New Preparation of the [closo-1-CB9H10]- Anion and the Crystal and Molecular Structure of [(η5-C5Me5)2Ir2Cl3]+ [closo-1-CB9H10]-
Authors: Nestor Karl , Štíbr Bohumil , Kennedy John D. , Thornton-Pett Mark , Jelínek Tomáš
Published: June 2004

A more convenient synthesis of the [closo-1-CB9H10]- anion, from the reaction of 6-(NMe3)-nido-6-CB9H11] with piperidine in THF, is reported. Reaction of [NMe4]+[1-CB9H10]- and [(η5-C5Me5)IrCl2]2 gives the ionic species [(η5-C5Me5)2Ir2Cl3]+ [closo-1-CB9H10]- as a yellow crystalline compound. Crystals are orthorhombic, space group Pnma, with a = 2505.9(6), b = 1223.6(3), c = 1029.8(3) ppm, and Z = 4. The structure was refined for 2329 reflections F > 4.0σ(F) to R = 0.0439. Both cation and anion possess crystallographic mirror-plane symmetry. Comparison of the structure of the anion with other formally closo ten-vertex structures reveals a previously unrecognised general opening.