bluuebunny/crossref_metadata_2025 huggingface dataset:
Embryo futures and stem cell research: the management of informed uncertainty
Authors: Ehrich Kathryn , Williams Clare , Farsides Bobbie , Scott Rosamund
Published: August 2011

In the social worlds of assisted conception and stem cell science, uncertainties proliferate and particular framings of the future may be highly strategic. In this article we explore meanings and articulations of the future using data from our study of ethical and social issues implicated by the donation of embryos to human embryonic stem cell research in three linked assisted conception units and stem cell laboratories in the UK. Framings of the future in this field inform the professional management of uncertainty and we explore some of the tensions this involves in practice. The bifurcation of choices for donating embryos into accepting informed uncertainty or not donating at all was identified through the research process of interviews and ethics discussion groups. Professional staff accounts in this study contained moral orientations that valued ideas such as engendering patient trust by offering full information, the sense of collective ownership of the National Heath Service and publicly funded science and ideas for how donors might be able to give restricted consent as a third option.
“PERHAPS YOU ONLY KISSED HER?”: A Contrapuntal Reading of the Penalties for Illicit Sex in the Sunni Hadith Literature
Authors: Lucas Scott C.
Published: August 2011

The goal of this essay is to illustrate how Ebrahim Moosa's method of “contrapuntal reading” can be applied fruitfully to the Sunni hadith literature. My case study is the set of penalties (hudud) for illicit sex, which include flogging, stoning, and banishment. I propose a fresh reading of these sacred texts that brings to the fore the ethical dimension of Prophet Muhammad's conduct, especially his strong reluctance to apply these measures. I conclude by identifying four ethical problems that the stoning penalty raises and suggest how the hadith literature can be read to argue against the validity of this specific punishment.
THE ETHICS OF PROPHETIC DISOBEDIENCE: Qur'an 8:67 at the Crossroads of Islamic Sciences
Authors: Ahmed Rumee
Published: August 2011

Medieval Muslim scholars were challenged with squaring their conceptions of prophetic infallibility with reports that Muhammad disobeyed revelatory commands from God. The manner in which they rehabilitated the prophetic image in these cases had corresponding repercussions in the fields of jurisprudence, theology, and legal theory. The present article uses the case of Q. 8:67 to demonstrate the intertwined nature of the Islamic sciences and the stakes involved when delimiting the prophetic ability to err and/or disobey God.
FORMATION, GRACE, AND PNEUMATOLOGY: Or, Where's the Spirit in Gregory's Augustine?
Authors: Smith James K. A.
Published: August 2011

Eric Gregory's Politics and the Order of Love takes up an audacious project: enlisting Saint Augustine in order to “help imagine a better liberalism.” This article first provides a summary of Gregory's argument, focusing on his emphasis on love as a “motivation” for neighborly care, and hence democratic participation. This involves tracing the theme of motivation in the book, which is tied to his articulation of liberal perfectionism and an emphasis on civic virtue. In conclusion I raise the question of whether his project has ignored a key aspect of Augustine's account of love, namely, the role of the Holy Spirit, thereby demarcating the limits of Gregory's “rational reconstruction” of Augustine.
BUDDHIST ETHICS: A Review Essay
Authors: Heim Maria
Published: August 2011

I argue that three recent studies (Imagining the Life Course, by Nancy Eberhardt;Sensory Biographies, by Robert Desjarlais; andHow to Behave, by Anne Hansen) advance the field of Buddhist Ethics in the direction of the empirical study of morality. I situate their work within a larger context of moral anthropology, that is, the study of human nature in its limits and capacities for moral agency. Each of these books offers a finely grained account of particular and local Buddhist ways of interpreting human life and morality, and each explores complex conceptions of moral agency. I suggest that these three studies share similar interests in moral psychology, the human being across time, the intersubjective dimensions of moral experience, and what life within a karmic framework looks like. I propose that their contributions offer some of the most refreshing and interesting work generated in Buddhist ethics in the last decade.
Effect of implant–abutment connection design on reliability of crowns: regular vs. horizontal mismatched platform
Authors: Freitas Júnior Amilcar C. , Bonfante Estevam A. , Silva Nelson R. F. A. , Marotta Leonard , Coelho Paulo G.
Published: August 2011

Objectives

To evaluate the reliability and failure modes of regular and horizontal mismatched platforms for implant–abutment connection varying the implant diameter.

Material and methods

Regular (REG, n = 21, 4.0‐mm‐diameter implant) and horizontal mismatched (HM, n = 21, 4.6‐mm‐diameter implant) platform Ti‐6Al‐4V implants were restored with proprietary identical Ti‐6Al‐4V abutments and metal crowns (cobalt‐chrome, Wirobond® 280, BEGO, Bremen, Germany) cemented. Mechanical testing comprised step‐stress accelerated‐life testing, where crowns were distributed in three loading profiles for fatigue in water, producing timely and clinically relevant fractures. The probability of failure vs. cycles (95% two‐sided confidence intervals) was calculated and plotted using a powerlaw relationship for damage accumulation, Weibull modulus (95% two‐sided confidence intervals) and then the reliability for a mission of 50,000 cycles at 125 N load (95% two‐sided confidence interval) were calculated. Fractography was performed in the scanning electron microscope.

Results

The β‐value for group REG (β = 1.37) indicated that fatigue was a factor accelerating the failure, whereas load alone dictated the failure for group HM (β = 0.71). The Weibull parameter contour plot showed no significantly different Weibull modulus for REG (10.24) compared to HM (10.20) and characteristic strength of 162.6 and 166.8 N, respectively (P > 0.91). The calculated reliability for a mission of 50,000 cycles at 125 N load was not significantly different (0.71 for REG and 0.73 for HM). Abutment screw failure was the chief failure mode.

Conclusions

Reliability was not significantly different between groups and failure modes were similar.
Identification of candidate substrates for poly(ADP‐ribose) polymerase‐2 (PARP2) in the absence of DNA damage using high‐density protein microarrays
Authors: Troiani Sonia , Lupi Rosita , Perego Rita , Re Depaolini Stefania , Thieffine Sandrine , Bosotti Roberta , Rusconi Luisa
Published: August 2011

Poly(ADP‐ribose) polymerase‐2 (PARP2) belongs to the ADP‐ribosyltransferase family of enzymes that catalyze the addition of ADP‐ribose units to acceptor proteins, thus affecting many diverse cellular processes. In particular, PARP2 shares with PARP1 and, as recently highlighted, PARP3 the sole property of being catalytically activated by DNA‐strand breaks, implying key downstream functions in the cellular response to DNA damage for both enzymes. However, evidence from several studies suggests unique functions for PARP2 in additional processes, possibly mediated through its basal, DNA‐damage unstimulated ADP‐ribosylating activity. Here, we describe the development and application of a protein microarray‐based approach tailored to identify proteins that are ADP‐ribosylated by PARP2 in the absence of DNA damage mimetics and might thus represent useful entry points to the exploration of novel PARP2 functions. Several candidate substrates for PARP2 were identified and global hit enrichment analysis showed a clear enrichment in translation initiation and RNA helicase molecular functions. In addition, the top scoring candidates FK506‐binding protein 3 and SH3 and cysteine‐rich domain‐containing protein 1 were selected and confirmed in a complementary assay format as substrates for unstimulated PARP2.

Structured digital abstract

 A list of the large number of protein‐protein interactions described in this article is available via the MINT article ID MINT‐8201796
Articles: Increasing Participation in Prevention Research: Strategies for Youths, Parents, and Schools
Authors: Hooven Carole , Walsh Elaine , Willgerodt Mayumi , Salazar Amy
Published: August 2011

TOPIC:  Subject participation is a critical concern for clinicians and researchers involved in prevention programs, especially for intensive interventions that require randomized assignment and lengthy youth and parent involvement.

PURPOSE:  This article describes details of an integrated approach used to recruit and retain at‐risk high school youths, their parents, and high schools to two different comprehensive, “indicated” prevention programs.

SOURCES USED:  Parent and youth recruitment and retention data for the two studies is provided in support of the approach described. A coordinated, multilevel approach, organized around cross‐cutting issues, is described in detail as a response to the challenges of including vulnerable populations in intervention research.

CONCLUSION:  Methods are relevant to nurse clinicians who deliver prevention programs, and are important to clinical research that relies upon adequate participation in research programs.
The Challenge Model: Examining Resilience in Pelzer's A Child Called “It”
Authors: Waibel‐Duncan Mary Katherine , Yarnell Jennifer Whitehouse
Published: August 2011

The rapidly emerging field of positive psychology has yielded theories, research, and best practice standards that may complement the work of nursing professionals as they assess and build upon individuals' unique areas of strength in the context of daily hassles, major life events, and exceptional circumstances. In this article, we summarize Wolin and Wolin's Challenge Model and illustrate its potential usefulness as a tool for examining resilience in pediatric patients. Through our own teaching and consultation experiences, we have found that the pairing of the Wolins' clinical model of human psychology and Dave Pelzer's A Child Called “It” provides a salient means of furthering current and prospective professionals' empathic regard for young patients and clients by promoting a more balanced and comprehensive understanding of children who face adversity.
Clopidogrel “Resistance”: Where are We Now?
Authors: Qureshi Zeshan , Hobson Alex R.
Published: August 2011

Antiplatelet therapy with aspirin and clopidogrel in PCI patients, though effective, is still associated with thrombotic complications. These are multifactorial in origin, but partially attributable to “clopidogrel resistance.” However, how best to identify and manage “clopidogrel resistance” remains unclear. Targeting therapeutic changes specifically at those individuals with poor response to clopidogrel is likely to be a solution. A “one size fits all” approach to clopidogrel dosing is probably flawed. This review will explore (1) the definition and mechanisms of clopidogrel resistance, (2) assessment of clopidogrel resistance by (i) platelet function testing and (ii) genetic testing, (3) the management of “clopidogrel resistance,” and (4) newer antiplatelet agents, and evolving stent technology. A pubmed literature review was performed using the keywords “clopidogrel”, “resistance”, “poor response”, “adverse events”, “platelet function tests”, and “genetic tests”. In looking at new agents, keywords “prasugrel”, “cangrelor”, “ticagrelor”“Elinogrel”, and “P2Y12 receptor antagonists” were used. Third, a search was performed looking at “stent design”, “IVUS”, “bioabsorbable stents”, and “stent apposition”. Whilst new P2Y12 receptor antagonists and improved stent technology may reduce thrombotic events in the future, there is still a need for clopidogrel. There is good evidence that poor response to clopidogrel is associated with adverse outcome. Platelet function tests probably provide more clinically useful data than genetic tests, but the question of how best to identify and manage variability in response to clopidogrel demands further research.
Effects of the Recombinant Form of the Natural Human B‐type Natriuretic Peptide and Levosimendan on Pulmonary Hyperventilation and Chemosensivity in Heart Failure
Authors: Bocchi Edimar Alcides , Moura Lídia Zytynski , Issa Victor Sarli , Cruz Fátima , Carvalho Vitor Oliveira , Guimarães Guilherme Veiga
Published: August 2011

Background: The origin of dyspnea in chronic heart failure (HF) is multifactorial, and excessive ventilation is thought to play a role in inducing this symptom. Chemosensivity is augmented in HF, correlates with increased pulmonary ventilation (VE), and is an adverse prognostic marker. Despite increased blood levels of natriuretic peptides in clinical conditions associated with dyspnea, their effect on pulmonary VE and chemoreceptor activity remains unexplored. Methods: We tested in a prospective, placebo‐controlled, three‐way cross‐over, double‐blind randomized study the effects of the recombinant form of the natural human B‐type natriuretic peptide (R‐BNP) in comparison with placebo and levosimendan on chemoreflex sensitivity at rest, as well as their effects on pulmonary VE, systemic blood pressure, heart rate and sympathetic serum activity both at rest and during exercise. Results: Eleven stable chronic HF patients were randomized to sessions of 6‐min treadmill‐walking tests during placebo, or levosimendan or R‐BNP intravenous infusion in the following conditions: room air, hypoxia, and hypercapnia. R‐BNP administration determined higher pulmonary ventilatory response at rest and during exercise (P < 0.001) consequent to a boost of respiratory rate (P < 0.001) under room air and hypoxia conditions. Norepinephrine blood levels increased from rest to exercise in all conditions without differences among placebo, levosimendan, and R‐BNP effects. BNP blood levels remained unchanged. Conclusions: The novelty of the present findings is that R‐BNP infusion in HF patients can boost pulmonary ventilatory response at rest and during exercise.
Refractoriness in Bipolar Disorder: Definitions and Evidence‐Based Treatment
Authors: Fountoulakis Konstantinos N.
Published: August 2011

Defining refractoriness in bipolar disorder is complex and should concern and include either every phase and pole or the disorder as a whole. The data on the treatment of refractory bipolar patients are sparse. Combination and add‐on studies suggest that in acutely manic patients partial responders to lithium, valproate, or carbamazepine, a good strategy would be to add haloperidol, risperidone, olanzapine, quetiapine, or aripiprazole. Adding oxcarbazepine to lithium is also a choice. There are no reliable data concerning the treatment of refractory bipolar depressives and also there is no compelling data for the maintenance treatment of refractory patients. It seems that patients stabilized on combination treatment might do worse if shifted from combination. Conclusively there are only limited and sometimes confusing data on the treatment of refractory bipolar patients. Further focused research is necessary on this group of patients.
5-Nitro-2-furylvinylation of substituted benzene derivatives
Authors: Hrabovský Ján , Kováč Jaroslav
Published: August 2011

5-Nitro-2-furylvinylation of o-, m-, and p-disubstituted and trisubstituted benzene derivatives afforded under conditions of Friedel-Crafts condensation (E)-2-substituted 1-(5-nitro-2-furyl)-ethylene.
X-ray crystallography of the sesquiterpene lactone erivanin
Authors: Rychłewska Urszula , Holub Miroslav , Błoszyk Ełżbieta , Drożdż Bohdan
Published: August 2011

X-ray structure analysis of the sesquiterpene lactone erivanin proved the correctness of the structure II proposed for this native compound earlier.
Mechanism of hypobromous acid addition to unsaturated steroids. Competition between neighboring group participation and external nucleophile attack
Authors: Kočovský Pavel , Tureček František , Černý Václav
Published: August 2011

Mechnism of hydrobromous acid addition to 2,3- and 5,6-unsaturated steroids bearing a 19-acetoxy group were established by means of isotopic labeling. In the cleavage of 2α,3α-bromonium ion III participation by the 19-acetoxyl predominates over external attack, 5(O)n process being the major (88%) and 7(O)π,n process the minor (10%) reaction. The external attack by water contributes only 2%. The 5α,6α-bromonium ion XI is cleaved by participation of the 19-acetoxyl at C(5) in a 6(O)π,n process (78%) via XII - XIII. Cleveage at C(6) leads to XIV and occurs partially with 7(O)π,n participation by the 19-acetoxyl (4%) and partially by external attack of water (8%). These results bring evidence for the formation of a seven-membered acetoxonium ion ring as intermediate in participation processes involving ester carbonyl groups.
Synthesis of adenylyl-(2'→5')adenylyl-(2'→5')adenosine
Authors: Karpeisky Marat Yu. , Beigelman Leon N. , Mikhailov Sergey N. , Padyukova Nelly Sh. , Smrt Jiří
Published: August 2011

Three syntheses of adenylyl-(2'-5')-adenylyl-(2'-5')-adenosine (Ib) are described. In the first, adenosine 2'(3') phosphate is polymerized by the action of diphenylphosphorochloridate, and the 3'-5' internucleotidic linkages and the thermal phosphoryl group removed enzymatically. The second is represented by the triester synthesis starting from 2',3'-di-O-acetyl-N-benzoyladenosine and 5'-O-monomethoxytrityl-3'-O-p-methoxybenzoyl-N-benzoyladenosine 2'(2-cyanoethyl) phosphate (IIc) using 2,4,6-triisopropylbenzenesulfonyl chloride as condensing agent. In the third, 3',5'-O-(tetraisopropyldisiloxane-1,3-diyl)adenosine (V) and 2',3'-di-O-benzoyl-N,N-dibenzoyladenosine serve as the components. The internucleotide bond is synthesized by means of 2-chlorophenylphosphoditriazolide (VI).
Eritadenines - Novel type of potent inhibitors of S-adenosyl-L-homocysteine hydrolase
Authors: Votruba Ivan , Holý Antonín
Published: August 2011

Rat liver SAH-hydrolase is strongly inhibited by four stereoisomeric 4-(adenin-9-yl)-2,3-dihydroxybutyric acids (eritadenines). D-Eritadenine, which is the most effective of the four, inactivates the catalytic activity of SAH-hydrolase at IC50 = 1.2 .10-8 mol l-1 in the hydrolytic reaction. The enzyme is irreversibly inhibited (τ/2 = 1.6 min). The inactivation activity decreases in the order D-erythro(2R, 3R) L-erythro(2S, 3S) threo(2S, 3R) threo(2R, 3S) configuration.
Stereospecific synthesis of isomeric 4-substituted 9-(2,3-dihydroxybutyl)adenines
Authors: Holý Antonín
Published: August 2011

Reduction of ethyl 2,3-O-isopropylidene-D-tartrate with sodium borohydride afforded (4S, 5S)-2,2-dimethyl-1,3-dioxolane-4,5-dimethanol (Va) which was benzoylated to give monobenzoyl derivative Vd and further transformed into p-toluensulfonyl derivative Ve. Reaction of the compound Ve with sodium salt of adenine followed by methanolysis gave 2,3-O-isopropylidene derivative Vf which on acid hydrolysis afforded 9-(2S, 3S)-(2,3,4-trihydroxybutyl)adenine (Ia). The enantiomer IIa was obtained from 3,4-O-isopropylidene-D-mannitol via (4R, 5R)-2,2-dimethyl-1,3-dioxolane-4,5-dimethanol (VIa) using the same procedure. Reaction of compounds Vf and VIf with p-toluenesulfonyl chloride afforded 4-O-p-toluenesulfonyl derivatives Vg and VIg. These compounds were also obtained from Va and VIa via di-p-toluenesulfonyl derivatives Vc and VIc by reaction with sodium salt of adenine. Treatment of compounds Vg and VIg with sodium iodide gave 4-iodo derivatives Vh and VIh which on reaction with tri-n-butyltin hydride, followed by acid hydrolysis, afforded enantiomeric threo-2,3-dihydroxybutyl derivatives Ib andIIb. Compounds Vg and VIg on treatment with sodium azide, subsequent catalytic hydrogenation of the intermediates Vj and VIj and acid hydrolysis afforded enantiomeric threo-9-(4-amino-2,3-dihydroxybutyl)adenines (Ic,IIc).
Polarography of benzo-1,2,3-dithiazolium salts
Authors: Tsveniashvili V. Sh.
Published: August 2011

Abstract in Russian
Calculation of transient supersaturation in the thermal diffusion cloud chamber at measurements of supersaturation spectrum of cloud condensation nuclei
Authors: Smolík Jiří , Vítovec Jaroslav
Published: August 2011

On the basis of numerical solution of material and energy balance including, beside diffusion and heat conduction, also the convective components of mass and heat transfer and interconversion of mechanical and thermal energies, the problem is analysed of transient supersaturation in the thermal diffusion cloud chamber at measurements of supersaturation spectra of cloud condensation nuclei (CCN). The results are compared with analytical solutions of the same problem for the case when diffusion and heat conduction are considered as the only mechanism of mass and heat transfer. The most advantageous case for measurement of supersaturation spectra CCN as results from the analysis, is that one when the temperature of the sample is equal to the arithmetic mean of temperatures of both plates of the chamber.
(E-Z)-Isomerization of unsaturated esters X-CH=CH-COOCH3
Authors: Všetečka Václav , Pecka Jaroslav , Procházka Miloš
Published: August 2011

Total energy differences for a series of (E) and (Z) isomers of unsaturated esters X-CH=CH-COOCH3 have been calculated by the CNDO/2 method. The applicability of this method to the prediction of relative stabilities of (E) and (Z) isomers and their optimal conformations was checked by comparison with the experimental data.
Isomerization of binor S
Authors: Kafka Zdeněk , Vodička Luděk , Galík Vlastimil
Published: August 2011

A new procedure was worked out for the isomerization of Binor S, the norbornadiene dimer (heptacyclo/8,4,0,02,12,03,8,04,6,05,9,011,13/tetradecane) with phosphorus pentoxide to obtain a mixture of hexacyclic olefins, viz. hexacyclo/8,4,0,02,7,03,14,04,8,09,13/tetradec-5-ene and hexacyclo/6,6,0,02,6,05,14,07,12,09,13/tetradec-3-ene, which serve as the starting material in the synthesis of triamantane.
Syntheses and antineoplastic effects of some N-substituted imides of 1-substituted 4-aryl-naphthalene-2,3-dicarboxylic acids
Authors: Křepelka Jiří , Vančurová Iva , Holubek Jiří , Roubík Jiří , Vlčková Drahuše
Published: August 2011

Condensation of anhydrides Ia-d with primary amines, 2-hydroxyethylamine or formamide gave imides III-XXII. The formation of N-(2-hydroxyethyl)imides was accompanied by replacement of the aromatic hydroxy group at position 1 by a 2-hydroxyethylamine residue (XX, XXII. Reaction of the imides XIX and XX with thionyl chloride produced the corresponding 2-chloroethyl derivatives XXIII and XXIV. Alkylation of the imide II, or its alkali salt prepared in situ, by ethyl bromacetate in a homogenous medium or by 2-(N,N-diethylamino)ethyl chloride in a biphasic medium, gave the imides XXV and XXVI, respectively. Condensation of the anhydrides Ia and/or Id with 1,2-diaminobenzene gave the respective imides XIII and XIV, and pentacyclic derivatives of 12H-benz(f)isoindole[2,1-a]benzimidazole-12-one (XXVII and XXVIII, respectively) as mixtures of positional isomers. In biological evaluation for antineoplastic efficiacy in animals with experimental tumours the imide XX proved to have the widest range of application.
Allosteric regulation of proline-inhibitable glutamate kinase from winter-wheat leaves by L-proline, adenosine diphosphate and low temperatures
Authors: Štefl Miroslav , Vašáková Ludmila
Published: August 2011

The determining way of regulation of proline biosynthesis in plants at normal and low temperatures has been discovered. The first enzyme of the biosynthetic pathway, allosteric glutamate kinase (GK 1), is very active at low temperatures (0°, -20°C). In the normal temperature range the biosynthesis of proline is controlled by inhibition of GK 1 through feedback by L-proline (I50 = 80μmol/l, I100 = 50mmol/l). At low temperatures the inhibition switches over into allosteric activation and the biosynthesis of proline is started. It is a new type of instantaneous change of central regulation of the enzyme with change of ecology. In a range of temperature ADP is only a partial allosteric inhibitor of GK 1. L-Proline, ADP and low temperature bring about complex heterotropic cooperatives in GK 1, which are demonstrated by changes in the relation {vo; [L-Glu]}. A hypothetical scheme of central regulation of proline-inhibitable glutamate kinase by L-proline with changes of temperature and concentration of salts has been worked out.
Oxidation of benzaldehyde by dioxygen. The thermal reaction
Authors: Lederer Pavel , Luňák Stanislav , Mácová Eva , Vepřek-Šiška Josef
Published: August 2011

The oxidation of benzaldehyde is catalyzed by transition metal ions even when these are present in trace concentrations. In complete absence of the ions, the reaction between benzaldehyde and dioxygen would not take place. A study has been made of the oxidation of benzaldehyde in benzene catalyzed by transition metal complexes. The catalytic activity of transition metals is higher when they assume their lower oxidation states. When the reaction is catalyzed by iron(III) bis(2,4-pentanedionato)-complex, the first reaction step is the reduction of Fe(III) to Fe(II), the latter being the catalyst of the thermal reaction. The mechanism proposed for the catalyzed reaction does not involve free radical formation.
Hydraulic characteristics of turbine impeller
Authors: Fořt Ivan , Malá Jana
Published: August 2011

The study concentrates on the determination of hydraulic characteristics (volumetric flow rate, power output, hydraulic efficiency and total head) of a standard, six-blade turbine impeller in a flat-bottomed cylindrical vessel provided with radial baffles at a turbulent regime of agitated liquid. The investigated characteristics are determined by means of a macroscopic balance of mechanical energy of the impeller region expressed in a dimensionless form. The results show that all the hydraulic characteristics investigated, with the exception of the dimensionless impeller total head, are independent of the impeller-to-vessel diameter ratio. The hydraulic efficiency of a standard turbine impeller is about 40%.
A simplified method of temperature control maximizing productivity of the batch reactor; The effect of inertia of the cooling system
Authors: Jiráček František , Horák Josef
Published: August 2011

The effect has been studied of the inertia of the cooling system on the reliability of control of the temperature of the reaction mixture. The study has been made using a mathematical model of the batch reactor with an exothermic reaction. The temperature has been controlled by a two-level controller opening and closing the flow of the coolant. The aim of the control has been to maintain a constant value of the degree of utilization of the cooling capacity of the reactor. The instantaneous value of the degree of utilization has been assessed from the ratio of times for which the cooling system is idle to the time of operation. The reliability of control has been studied for variable activity of the catalyst.
Identification of aromatic hydrocarbons in high-boiling fraction of pyrolysis oil by capillary gas-liquid chromatography and mass spectrometry
Authors: Novrocík Jan , Novrocíková Marta , Čapek Antonín
Published: August 2011

Capillary gas chromatography and mass spectrometry have been used for identification of most main high-boiling components of fraction of pyrolysis oil (boiling point 250 to 350° C under normal pressure) especially those boiling above the b.p. of acenaphthene. All methyl homologues of acenaphthene, phenanthrene, some isomeric methylfluorenes, trimethyl- and methylethyl naphthenes, phenylnaphthalenes, dimethylbiphenyls, benzindans, methylbenzindans and other aromatic hydrocarbons have been prepared as standards. In connection with the preparation of some trimethyl- and methylethylnaphthalenes a discussion is presented of the course of chloromethylation and acetylation of 1- and 2-methyl- and 2-ethylnaphthalenes. Content of methyl-homologues of some hydrocarbons (acenaphthene, fluorene, phenanthrene, and anthracene) in the high-boiling fraction of pyrolysis oil has been compared with that present in similar fraction of coal tar.
Spectrophotometric study of the reactions of lanthanoids with bromopyrogallol red in the presence of cation active tensides
Authors: Němcová Irena , Plocková Pavla , Con Tran Hong
Published: August 2011

The absorption spectra of the binary complexes of lanthanoids with bromopyrogallol red were measured and the formation of ternary complexes with cation active tenside, Septonex, was studied. Optimal conditions were found for the formation of these complexes and the possibility of their use in the photometric determination of lanthanoids was demonstrated on several examples.
Human hemopexin. Preparation of the heme-rich protein
Authors: Morávek Ladislav , Borvák Josef , Grüner Karel , Meloun Bedřich , Štrop Petr , Hrkal Zbyněk , Pokorný Miloš
Published: August 2011

A simplified procedure was developed for the preparation of hemopexin from Cohn fraction IV obtained from partially hemolyzed pooled samples of serum. The method is based on precipitation with rivanol, chromatography on DEAE-cellulose, and gel filtration; it permits large quantities of the material to be treated on a laboratory scale. The preparation of heme-rich hemopexin obtained was characterized by amino acid analysis and the following N-terminal amino acid sequence: Thr-Pro-Leu-Pro-Arg-Gly-Ser-Ala-His-Gly-Asn-Val-Ala-Glu-Gly-Glu-Thr(Thr)Thr-Asn-Pro-Asp-Val-(Gly)(Leu).
Application of the correlation according to rod and of arranged NRTL equation for calculation of liquid extraction
Authors: Dojčanský Ján , Surový Július , Bafrncová Soňa
Published: August 2011

Ternary equilibrium data in the liquid-liquid system, calculated on thermodynamic basis by use of the arranged NRTL equation, are compared with the distribution coefficients of individual components and concentrations of the extracted component, obtained by the correlation according to Rod. On simple extraction examples, the effect of quality of equilibrium data on the results of chemical engineering calculation of the number of equilibrium stages at countercurrent extraction, is evaluated.
Micro-packed columns with graphitized thermal carbon black
Authors: Feltl Ladislav , Antonínová Marcela , Smolková Eva
Published: August 2011

Two types of column were prepared, conventional packed and micro-packed with Sterling MT graphitized thermal carbon black (GTCB). Comparison demonstrated the advantages of the micro-packed column. The adsorption of C5-C10 alkanes and C4-C10 1-alkenes was studied on these columns in the interval 448.15-488.15 K. The differential heats of adsorption were calculated by the linear regression method from the temperature dependence of the specific retention volumes and the usefulness of the micro-packed column for determination of adsorption thermodynamic quantities was evaluated on the basis of the results. The separation efficiency of the two columns was demonstrated on the separation of a mixture of the geometric isomers of tricyclododecane.
Electronic effect of and mutual polarizability in groups attached to oxygen via their C, Si, Ge, and B atoms
Authors: Pola Josef , Chvalovský Václav
Published: August 2011

Relative acidity of triphenylhydroxy substituted germane and stannane is consistent with superior electrondonating effect of (C6H5)3Ge and (C6H5)3Sn groups in these compounds. Relative basicity data of alkyl(alkoxy) boranes, methanes, silanes, and germanes (RO)nZRm (Z = B, C, Si, and Ge) are compiled. The variation of the electronic effect parameter σ of fully alkylated RmZ-groups upon substitution of their alkyl with ethoxy substituent appears for Z=B and Si to be influenced by mutual polarizability effect of ethoxy substituents. Mutual polarizability of ethoxy substituents attached to carbon and germanium is negligible.
Characterization of the sulfated glycopeptide of chicken pepsinogen
Authors: Baudyš Miroslav , Kostka Vladimír , Grüner Karel , Pohl Jan
Published: August 2011

S-sulfonated chicken pepsinogen was digested with TPCK-trypsin; large tryptic peptides, separated on Sephadex G-25 fine, were subjected to additional cleavage with α-chymotrypsin. The hold-up fraction of the chymotryptic digest from the Sephadex G-25 column, was resolved by high voltage electrophoresis. The three most acidic zones contained glycopeptides of identical amino acid sequence Val-Ser-Thr-Asn-Glu-Thr-Val-Tyr, yet differed in the composition of the sugar moiety. These glycopeptides, moreover, bear different numbers of sulfate groups which enabled the resolution of the peptides. The most acidic glycopeptide contains 7 glucosamine residues, 3 mannose residues and 5 sulfate groups, the second one 6 glucosamine residues, 3 mannose residues and 4 sulfate groups and the slowest, minority glycopeptide, 5 glucosamine residues, 2 mannose residues and 2 sulfate groups. The entire sugar moiety is attached to one of the chain viaasparagine. In other experiments the glycopeptides were also isolated from the thermolytic digest of chicken pepsin; their C-terminal sequence was shorter by two amino acid residues. The tentative assignment of the glycopeptides to the amino acid sequence of pepsinogen resulted from the analysis of the limited tryptic digest of the whole protein molecule. Chicken pepsinogen is glycosylated at the site of the chain occupied by a phosphoserine residue in hog pepsinogen A.
Chemical pseudoexcitation of the CO ligand and vibrational frequences of transition metal carbonyls
Authors: Řeřicha Roman
Published: August 2011

The forward- and back-donations of electrons between the CO ligand and central transition element atom lead to a system of cumulated multiple bonds of the type X=Y=Z. From a "vibrational" point of view this fact means a non-separability of vibrational motions of the three MCO nuclei. A coupling of the stretching vibrations ν1(MC) and ν3(CO) leads to analogous fundamental frequencies as in the case of the isolated stable molecules of O=C=O, S=C=O, Se=C=O, etc. The magnitude of the vibrational coupling between ν1 and ν3 is roughly proportional to the fundamental frequency of the degenerated deformation vibration ν2ab of the MCO grouping, i.e. a ratio of the frequencies should be constant. With free molecules of CO2, SCO, CS2, N2O and others, the ratio (ν1 + ν3)/ν2ab of the fundamental frequencies is equal to 5.5 like with complex anions [(CO)PtX3]- regardless X = Cl, Br or I. For other transition metal carbonyls the ratio is within the range of 4.0-6.0. On the other hand, the H3B-C=O molecule as a system with the essentially single B-C and the triple C=O bond is characterized by a markedly different value (9.0). In the latter, the local electronic state of CO is similar to the electronic ground state of the positive ion CO+ of the free molecule. In the transition metal carbonyls the chemical pseudoexcitation of the CO ligand leads to its local electronic states which are similar to electronic excited states lying between an excited valence state of the free neutral CO molecule (back-donation is equal to one electron) and an excited valence state of the free negative ion CO- (back-donation is equal to two electrons.
Solubility of Na2O2.8 H2O in the system H2O2-NaOH-KOH-H2O
Authors: Balej Jan , Špalek Otomar
Published: August 2011

The solubility of Na2O2.8 H2O in the multicomponent system H2O2-NaOH-KOH-H2O has been investigated at temperatures of 12, 20, and 30°C. Comparison of the data with solubilities of the same compound in the simler system H2O2-NaOH-H2) shows that the presence of potassium hydroxide increases the solubility at the same temperature and total content of hydroxide ions. The effect of potassium ions on the solubility of Na2O2.8 H2O is expressed by an empirical equation relating the apparent equilibrium constant of the dissolution reaction and the molalities of the perhydroxyl and potassium ions at a given temperature.
The kinetics of partial processes in the oxidation of ascorbic acid catalyzed by vanadyl tetrasulphophthalocyanine
Authors: Wagnerová Dana M. , Votruba Jaroslav , Blanck Jürgen , Vepřek-Šiška Josef
Published: August 2011

The rapid partial reactions of the oxidation of ascorbic acid by dioxygen with vanadyl tetrasulphophthalocyanine as a catalyst were studied by the stopped-flow method. The experimental data were treated on a computer and compared with the kinetic implications resulting from the proposed mechanism. Application of the adaptive identification method led to quantitative solution of the mechanism, i.e. determination of the values of all the isolated rate constants of the reaction mechanism.
Intermolecular cyclization of o-fuchsones
Authors: Píšová Milena , Souček Milan
Published: August 2011

o-Fuchsones formed by dehydrohalogenation of o-hydroxyaryl(diaryl)methyl chlorides with tertiary amines undergo a cyclization to eight-membered dimers of the type head to tail. The dimerization reaction is catalyzed by tertiary amines hydrochlorides involving very likely triarylmethyl cation as intermediates.
Structural units of maltenes and asphaltenes from hydrogenation of coal
Authors: Lang Ivo
Published: August 2011

The calculation of the unit structure weight (USW) from NMR data is discussed. A comparison with the average molecular weight (Mr) values from vapour phase osmometry and mass spectrometry measurements showed that for the coal maltenes investigated (the fraction from the coal hydrogenation product soluble in pentane), USW can be looked upon as a rapid approximation of Mr. For asphaltenes, the calculation of USW is to a high extent dependent upon the assumed arrangement of the aromatic system. For an approximation of Mr of the asphaltenes studied, the most satisfactory was the calculation of USW from parameters of the Williams method assuming the occurrence of a peri-cata-condensed system. The USW of coal hydrogenation products calculated from NMR (1H and 13C) spectra should not be attributed the physical meaning of their smallest building units.
Optimal temperatures for the periodic steady state in a cascade of stirred adsorbers
Authors: Brunovská Alena , Brunovský Pavol
Published: August 2011

A cascade of stirred adsorbers with a cyclic mode of operation under which adsorbers are periodically removed for activation and replaced by reactivated ones is considered. A method of computation of temperatures maximizing the period under the requirement that the outlet concentration is below a given level is presented.
5-Substituted 2-furancarbaldehydes and water-soluble furan derivatives
Authors: Végh Daniel , Kováč Jaroslav , Dandárová Miloslava
Published: August 2011

5-Halo-2-furaldehydes Ia, Ib react with trimethylamine in aprotic solvents to furnish 5-trimethyl-ammonium salts of 2-furaldehyde IIa, IIb. The reactivity of this salt was utilized for a simple preparation of 5-substituted 2-furaldehydes IV in water at room temperature. The possibility to synthesize azomethines V and ethylenes VI, having the trimethylammonium group in position 5 of the furan ring maintained, is discussed.
Optically active tricyclic dilactams with non-planar cis-amide groups: Synthesis, X-ray, NMR and CD studies
Authors: Bláha Karel , Buděšínský Miloš , Koblicová Zdena , Maloň Petr , Tichý Miloš , Baker J. R. , Hossain M. B. , Van der Helm Dick
Published: August 2011

Three tricyclic dilactams were investigated as models for study of chiroptical properties of homoconjugated non-planar cis-amide groups. Racemic 5,8-diazatricyclo[6,3,0,01,5]undecane-4,9-dione (I) was partially resolved into enantiomers by chromatography on acetylcellulose. The 6-isobutyl (II) and 6-methyl (III) derivatives were prepared in optically pure forms by condensation of diethyl 4-oxoheptanedioate with (S)-1,2-diamino-4-methylpentane and (S)-1,2-diamino-propane, respectively. The respective diamines were synthesized starting from (S)-leucine and (S)-alanine: this determined the absolute configuration on the C(6) atom in both dilactams. As shown by 1H and 13C NMR spectra, the condensation reaction afforded only one of the two possible diastereoisomeric dilactams. The configurational relation between the chiral center at C(6) and the chirality of the tricyclic moiety was derived from coupling constants in the 1H NMR spectra. The configuration of compound II was confirmed by X-ray diffraction. According to 1H NMR spectra, the spatial arrangement of II in solution is similar to that in crystal, the only difference being in the local conformation of the isobutyl side chain at C(6). IR spectroscopy identified only minor differences in geometry of the two lactam groupings in II and III. All CD parameters of compounds I-III, measured in various solvents, are very similar. The CD curves show the same absolute configuration (1S, 6S) of compounds II and III and the opposite configuration of the studied enantiomer of I(1R). Parameters of the n-π dichroic band indicate a non-planar amide-grouping whose geometry is known from the X-ray analysis. Its sign agrees with the relationship derived for the chiroptical properties of defined pyramidicity on nitrogen atom in non-planar amides. The π-π dichroic bands exhibit an exciton splitting into a couplet as a result of interaction between the amide groups.
Hydrolytic products of Fe(III) after oxidation of Fe(II) by chlorate
Authors: Mádlo Karel , Hanousek František , Petřina Antonín , Tláskal Jaroslav
Published: August 2011

Ferrous sulphate was oxidized by potassium chlorate in the pH region 2-7 and at temperatures ranging from 298.1 to 323.1 K and various hydrolytic products of Fe(III) were separated and indentified. The separated solid ferric products were analyzed using a combination of the chemical analysis, IR spectroscopy, X-ray diffraction, and electron microscopy. The following substances were found as major components of the products: Fe2O3.n H2O ("ferric gel"), Fe2O3.n H2O with bound SO2-4 ions ("sulphogel"), α-FeO(OH), γ-FeO(OH) and Fe3O4. Their amount depends particularly on the pH temperature of the reaction medium.
Spectrophotometric study of the complex equilibria of cadmium(II) ions with 4-(2-pyridylazo)resorcine (PAR) using the SQUAD-G program and the method of determining Cd(II) ions with PAR
Authors: Vlčková Sylva , Jančář Luděk , Kubáň Vlastimil , Havel Josef
Published: August 2011

The existence of the red-orange CdLH+ complex (λmax = 406 nm, εmax = 1.78.104 mmol-1.cm2, log *β111 = -1.66+0.04) and CdL complex (λmax = 495 nm, εmax = 3.2.104 mmol-1. cm2, log *β112 = -8.25+0.05) was demonstrated in aqueous solutions of PAR with a concentration excess of Cd(II) ions. It was shown that a 10% v/v acetone medium containing Cd(II) in a concentration excess of PAR contains the following complexes: CdL2H2 (λmax = 507 nm, εmax = 1.4 . 104 mmol-1 cm(2), log*β122 = -2.85+0.04), CdL2H- (λmax = 495 nm, εmax = 6.25 . 104 mmol-1 cm2, log *β123 = -9.58 + 0.04) and CdL2-2 (λmax = 495 nm, εmax = 9.16 . 104 mmol-1 cm2, log *β124 = -17.33 + 0.06). The basic parameters of the individual complexes were determined by graphical interpretation using slope-intercept transformations and by numerical interpretation using the generalized SQUAD-G program. The statistical parameters of the spectrophotometric method of determining cadmium ions were evaluated from the linear part of the calibration curve using the STAT program.
INDO/S calculations on simple silicon compounds and some silicon organic molecules
Authors: Sauer Joachim , Čársky Petr , Zahradník Rudolf
Published: August 2011

The INDO/S method has been extended to silicon-containing systems. On the basis of test calculations for SiH2, SiHCl, SiF2, SiH, SiN, SiO+, SiF and SiO we suggest the following semiempirical parameters: βoSi = -4 eV and γSi = 5.5 eV. Additional molecules treated are SiH+, SiS, SiCC, SiCSi, SiCl, SiCl2, SiO2, HNSi, and vinyl- and phenylsilane. Comparison is made with the corresponding carbon species CH2, CF2, CCl2, CH+, CO, CS, CH, CF, CN, CO+, CO2, C3 and benzene. The method with the suggested Si parameter set is employed for the investigation of the electronic structure and electronic spectra of unstable molecules of silaethylene, silylmethylene, methylsilylene, disilylene, silylsilylene and silabenzene.
Determination of acids and their strength in isobutyl methyl ketone
Authors: Dostál Vladimír , Stránský Zdeněk , Slouka Jan
Published: August 2011

The dissociation constants of nitrophenoxazines in isobutyl methyl ketone (MIBK) were determined and correlated with the HNP values in acetone. Of the derivatives studied, the strongest acid is 1,3,7-trinitrophenoxazine (pK = 19.8), the weakest, 1-nitrophenoxazine (pK > 26). The compounds have no tendency to homo- or heteroconjugation, and were used as indicators in determination of weak acids in MIBK. Some derivatives of malonic acid and of 1,2,4-triazine as well as the intermediates used in their synthesis were determined; their HNP and pK values were established. The shape of the potentiometric titration curves can be of assistance in solving some structure problems.
Ammonium uranyl carbonates - Complex compounds with variable coordination number?
Authors: Baran Václav
Published: August 2011

A series of ammonium uranyl carbonate (AUC) solid samples were prepared. Their chemical composition varied systematically and corresponded to the formula (NH4)x[UO2(CO3)y] with molar coefficients from x = 4.0 and y = 3.0 to 1.1 and 1.3, resp. The first samples of this series, with x in the range 4.0-2.7 and y in the range 3.0-2.3, revealed identical IR spectra as well as X-ray patterns, in contrast to the other ones. A reliable explanation of this fact is not at hand, one of the possibilities being the variable coordination number of the uranyl central ion. IR spectra of AUC and its sodium analogue were confronted, too, with the conclusion that architecture of both complexes is the same but with distinct quantitative differences.
X-ray diffractograms and IR spectra of modified vanadium-phosphate catalysts
Authors: Brutovský Milan , Gerej Štefan , Vasilco Fedor , Gerejová Judita
Published: August 2011

Structure of vanadium-phosphate catalysts (V : P = 1 : 1.2) modified by addition of Li, Ba, Mn, Fe, Co, Ni, Cu, Zn, Pd, Cd, Sn or Ce has been studied by X-ray diffractometry and IR spectroscopy. Dimension of particles is diminished, and degree of arrangement of structure of the contact catalyst is lowered in the presence of the additives as compared with the non-modified catalyst, which can be explained by incorporation of these additives (except for Pd) in the lattice of the basic catalyst. Crystalline phase (VO)2P2O7 has been found in all the catalysts besides the cyclic anion P4O124-; the non-modified and the Ba-containing catalysts contain also the compound VO(PO3)2.
7-(3-Substituted amino-2-hydroxypropyl)-8-benzyl-, or -8-phenyltheophyllines
Authors: Štibrányi Ladislav , Rybár Alfonz , Jendrichovský Ján , Boženková Lýdia , Kovalčík Vladimír
Published: August 2011

N-Substituted derivatives of 7-(3-amino-2-hydroxypropyl)-8-benzyl- (V), or -8-phenyltheophylline (VI) were prepared by addition of the appropriate amines to 7-epoxypropyl-8-benzyl- (III), or -8-phenyltheophyllines (IV). Compounds III and IV were obtained by alkylation of 8-benzyl-, or 8-phenyltheophyllines with 1-chloro-2,3-epoxypropane. DerivativesV and VI exhibited a peripheral vasodilatation effect in vitro.
Fluorinated tricyclic neuroleptics with prolonged action: 8-Methoxy, 8-ethoxy, 8-ethylthio and 8-hydroxy derivatives of 3-fluoro-10-(4-methylpiperazino)-10,11-dihydrodibenzo[b,f]thiepin
Authors: Jílek Jiří , Pomykáček Josef , Metyšová Jiřina , Protiva Miroslav
Published: August 2011

Acids IIa-c were prepared by reactions of (4-fluoro-2-iodophenyl)acetic acid with 4-methoxythiophenol, 4-ethoxythiophenol and 4-(ethylthio)thiophenol and cyclized with polyphosphoric acid in boiling toluene to dibenzo[b,f]thiepin-10(11H)-ones IIIa-c. Reduction with sodium borohydride afforded the alcohols IVa-c which were treated with hydrogen chloride and gave the chloro derivatives Va-c. Substitution reactions with 1-methylpiperazine resulted in the title compounds Ia-c out of which the methoxy derivative Ia was transformed by demethylation with boron tribromide to the phenol Id. Compounds Ia-d are very potent neuroleptics exhibiting a clear prolongation of the central depressant and some prolongation of the cataleptic activity.