bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessing the effects of sodium on fire ant foraging in the field and colony growth in the laboratory
Authors: RESASCO JULIAN , PORTER SANFORD D. , SANDERS NATHAN J. , LEVEY DOUGLAS J.
Published: December 2013

Sodium is an essential dietary element and preferential foraging for high concentrations of sodium by inland herbivorous and omnivorous ants suggests it may be limiting. If so, increased sodium availability through altered deposition and anthropogenic sources may lead to increased colony and population growth and cascading ecological impacts.

For red imported fire ants,Solenopsis invictaBuren, the present study tests: (i) whether colonies from coastal and inland sites differ in their responses toNaClbaits; and (ii) whether supplementalNaClincreases growth of fire ant colonies in the laboratory.

Fire ants in inland sites with low sodium deposition responded roughly an order of magnitude more strongly to high concentrations ofNaClbaits than did fire ants in coastal sites with high sodium deposition.

Laboratory colonies of fire ants, however, showed no signs of sodium limitation or benefits of increased sodium. The link between behavioural responses to baits in the field and effects on colony growth deserves further investigation to assess the ecological impacts of altered sodium availability.
Expression of vesicle‐associated membrane‐protein‐associated protein B cleavage products in peripheral blood leukocytes and cerebrospinal fluid of patients with sporadic amyotrophic lateral sclerosis
Authors: Deidda I. , Galizzi G. , Passantino R. , Cascio C. , Russo D. , Colletti T. , La Bella V. , Guarneri P.
Published: December 2013

Background and purpose

Vesicle‐associated membrane‐protein‐associated protein B (VAPB) is an endoplasmic reticulum (ER) resident protein participating in ER function, vesicle trafficking, calcium homeostasis and lipid transport. Its N‐terminal domain, named MSP, is cleaved and secreted, serving as an extracellular ligand. VAPB mutations are linked to autosomal‐dominant motor neuron diseases, including amyotrophic lateral sclerosis (ALS) type 8. An altered VAPB function is also suspected in sporadic ALS (SALS).

Methods

The expression pattern of VAPB cleavage and secreted products in the peripheral blood leukocytes (PBL) and cerebrospinal fluid (CSF) of SALS patients and neurological controls was assessed. PBL from healthy controls were also analyzed. Assays were carried out through western blotting, using an anti‐VAPB (N‐terminal) antibody.

Results

Two VAPB fragments containing the MSP domain (17 kDa and 14 kDa molecular sizes) were identified in PBL of SALS and controls, with no significant differences amongst groups. In CSF, only the 14 kDa VAPB MSP fragment was expressed and a corresponding VAPA fragment was not detected. The CSF VAPB fragment was absent in 58.7% of SALS patients, of whom 79.2% were bulbar onset (P = 0.001, bulbar versus spinal).

Conclusions

The absence of the CSF VAPB MSP fragment from most bulbar‐onset SALS patients suggests a specific alteration of brain‐derived VAPB cleavage and secretion in this group of patients, and hints at a role of VAPB in the pathophysiology of this motor neuron disease.
Hemodynamic evidence linking cognitive deficits in clinically isolated syndrome to regional brain inflammation
Authors: Papadaki E. Z. , Simos P. G. , Panou T. , Mastorodemos V. C. , Maris T. G. , Karantanas A. H. , Plaitakis A.
Published: December 2013

Background and purpose

To investigate the relation between hemodynamic measurements and memory function in patients with clinically isolated syndrome (CIS).

Methods

Forty CIS patients were administered tests of verbal short‐term/working memory and passage learning. Using dynamic susceptibility contrast MRI cerebral blood volume (CBV), cerebral blood flow and mean transit time values were estimated in 20 cerebral regions of interest, placed in normal appearing white matter (NAWM) and normal appearing deep gray matter structures, bilaterally.

Results

CIS patients showed significantly impaired scores on working memory and secondary verbal memory that correlated inversely with elevated CBV values in the left frontal and periventricular NAWM, thalamus, right caudate and corpus callosum.

Conclusions

Verbal memory in CIS correlates inversely with elevated CBV values of brain structures involved in memory. As these hemodynamic changes, detected in CIS, are indicative of inflammation, the observed cognitive disturbances may relate to widespread brain inflammatory processes that prevail in early multiple sclerosis.
A longitudinal study of family structure in Swedish persons with haemophilia
Authors: Lövdahl S. , Henriksson K. M. , Baghaei F. , Holmström M. , Berntorp E. , Astermark J.
Published: December 2013

Haemophilia is an X‐linked inherited rare bleeding disorder affecting mainly men. The treatment consists of replacement therapy that has been associated with severe side effects, such as blood transmitted viral infections, but has markedly improved over the last decades. The aim of this study was to study family structure over time among Swedish persons with haemophilia (PWH), focusing on children, siblings and marital status. PWH A or B were identified from the haemophilia centres and the national Patient Registry. Each PWH was compared to five age‐ and gender‐matched controls. The national Multi‐Generation Registry was used to identify children and siblings. A total of 1365 children with a father suffering from haemophilia A or B and 1938 siblings of the PWH were identified. Having one or more children was significantly less common (P = 0.003) for PWH than for controls. Significantly lower rates of having a child were also found for the subgroups of persons suffering from severe haemophilia and those infected with HIV (P < 0.001). A higher proportion of PWH, with or without HIV and/or viral hepatitis had siblings compared to the controls (P < 0.001). However, the mean number of siblings was significantly lower for persons with severe haemophilia (P = 0.001). The number of marriages and divorces did not differ between PWH and controls. Our data indicate a negative impact of HIV and viral hepatitis on family structure for PWH despite the relatively good access to treatment in Sweden over the last few decades. This was particularly true for those with a severe form of haemophilia.
Preoperative indicators of length of stay following total hip replacement: a New Zealand‐based retrospective, observational study
Authors: Le Mar Karen Jane , Whitehead Dean
Published: December 2013

Aims and objectives

To identify preoperative risk factors that potentially affect postoperative length of stay of patients undergoing total hip replacement.

Background

With limited health resources and an ageing population, alongside an increasing prevalence of osteoarthritis and the growing need for total hip replacement, reducing length of stay is a mainstay of effective and cost‐efficient orthopaedic practice.

Design

A retrospective observational study.

Methods

Data from a convenience sample of 243 patients having undergone an elective unilateral total hip replacement between January 2008–December 2009 were collected. Demographic data were studied and allied against the main preoperative risk factors – with length of stay being the main outcome measure.

Results

Pearson's correlation demonstrated a moderate positive correlation between age and a longer postoperative stay. The number of comorbidities did not have an impact on length of stay. Demographic findings included almost half the cohort lived with hypertension, and 66% of the available cases (n = 196) were deemed overweight.

Conclusions

Collecting accurate and comprehensive assessment information relating to preoperative risk factors for total hip replacement, significantly impacts on postoperative outcomes specifically related to length of stay.

Relevance to clinical practice

In complex healthcare systems, where there is a need for quality client outcomes tempered against limited resources, this study highlights the benefits of accurate preassessment of orthopaedic clients undergoing major surgical intervention against the desirable outcomes of reduced lengths of admission.
Constipation – prevalence and incidence among medical patients acutely admitted to hospital with a medical condition
Authors: Noiesen Eline , Trosborg Ingelise , Bager Louise , Herning Margrethe , Lyngby Christel , Konradsen Hanne
Published: December 2013

Aims and objectives

To examine the prevalence and incidence of patient‐reported symptoms of constipation in acutely hospitalised medical patients.

Background

Constipation is a common medical problem with severe consequences, and most people suffer from constipation at some point in their lives. In the general population, constipation is one of the most common complaints and is a significant personal and public health burden. Alteration in patients’ patterns of elimination while in hospital has long been identified as either a potential or an actual problem that requires attention. Knowledge of the prevalence and incidence of constipation during hospitalisation is only sporadic.

Design

The study was descriptive and a prospective cohort design was chosen.

Methods

The Constipation Assessment Scale was translated into Danish and was used for the assessment of patient‐reported bowel function. Five nurses made the assessments at admission to the acute medical ward and three days after admission. Three hundred and seventy‐three patients participated in this study.

Results

Thirty‐nine percent of the patients showed symptoms of constipation at admission. Of the patients who did not have the symptoms at admission, 43% developed the symptoms during the first three days of their stay in hospital. Significantly more of the older patients developed symptoms of moderate constipation. The incidence rate was 143 new cases per 1000 patient days.

Conclusions

In this study, symptoms of constipation were common among patients acutely admitted to hospital due to different medical conditions. Symptoms of constipation were also developed during the first three days of the stay in hospital.

Relevance to clinical practice

The study highlights the need to develop both clinical guidelines towards treating constipation, and preventive measures to ensure that patients do not become constipated while staying in hospital.
Effect of prolonged wakefulness on electroencephalographic oscillatory activity during sleep
Authors: Olbrich Eckehard , Landolt Hans Peter , Achermann Peter
Published: December 2013

The human sleep electroencephalogram (EEG) is characterized by the occurrence of distinct oscillatory events such as delta waves, sleep spindles and alpha activity. We applied a previously proposed algorithm for the detection of such events and investigated their incidence and frequency in baseline and recovery sleep after 40 h of sustained wakefulness in 27 healthy young subjects. The changes in oscillatory events induced by sleep deprivation were compared to the corresponding spectral changes. Both approaches revealed, on average, an increase in low frequency activity and a decrease in spindle activity after sleep deprivation. However, the increase of oscillatory events in the delta range and decrease in the sigma range occurred in a more restricted frequency range compared to spectral changes. The mean relative power spectra showed a significant increase in theta and alpha activity after sleep deprivation while, on average, the event analysis showed only a weak effect in the theta band. The reason for this discrepancy is that the spectral analysis does not distinguish between diffuse activity and clearly visible temporally localized oscillations, while the event analysis would detect only the latter. Additionally, only a few individuals clearly showed activity in the theta or alpha frequency bands. Conversely, event analysis revealed that some individuals showed an increased rate of sleep spindles after sleep deprivation, a fact that was not evident in the relative power spectra due to a decrease in background activity. The two methods complement each other and facilitate the interpretation of distinct changes induced by prolonged wakefulness in sleep EEG.
Functional characterization of the three mitogen‐activated protein kinase kinases (MAP2Ks) present in the Cryphonectria parasitica genome reveals the necessity of Cpkk1 and Cpkk2, but not Cpkk3, for pathogenesis on chestnut (Castanea spp.)
Authors: Moretti Marino , Rossi Marika , Ciuffo Marina , Turina Massimo
Published: December 2013

The biological function(s) of the cpkk1, cpkk2 and cpkk3 genes, encoding the three mitogen‐activated protein kinase kinases (MAP2Ks) of Cryphonectria parasitica, the causal agent of chestnut blight, were examined through knockout strains. Cpkk1, the Mkk1 orthologue, acts in a phosphorylation cascade essential for cell integrity; Cpkk2 is the Ste7 orthologue involved in the pheromone response pathway; Cpkk3 is the Pbs2 orthologue, the MAP2K activated during the high‐osmolarity response. Our analysis confirmed the role of each MAP2K in its respective signalling cascade with some peculiarities: abnormal hyphae with a reduced number of septa and thinner cell walls were observed in Δcpkk1 mutants, and a strong growth defect on solid media was evident in Δcpkk2 mutants, when compared with the controls. Virulence on chestnut was affected in both the Δcpkk1 and Δcpkk2 strains, which were also unable to complete the developmental steps essential for mating. No alterations were reported in Δcpkk3, except under hyperosmotic conditions and in the presence of fludioxonil. Δcpkk2 mutants, however, showed higher sensitivity during growth in medium containing the antibiotic G418 (Geneticin).
Journey to become a nurse leader mentor: past, present and future influences
Authors: McCloughen Andrea , O'Brien Louise , Jackson Debra
Published: December 2013

Mentorship, often viewed as a central capacity of leadership, is acknowledged as influential in growing nurse leaders. Mentoring relationships are perceived as empowering connections offering a dynamic guided experience to promote growth and development in personal and professional life. A hermeneutic phenomenological approach informed by Heidegger and Gadamer was used to explore understandings and experiences of mentorship for nurse leadership by 13 Australian nurse leaders. We found that learning and transformation associated with becoming a nurse leader mentor was experienced as an enduring evolutionary process. Participants' life journeys provided experiences that developed their understandings and established their personal identity as a leader and mentor. We considered the journey motif in terms of its inextricable connection with lived time and used Heidegger's ecstasies of temporality as a lens to understand how the temporal dimensions of past, present and future influenced and shaped the development of nurse leader mentors. We found that our temporal existence influences interpretation of ourselves and the world. Individuals can benefit from multiple separate mentoring interludes, with different mentors, over a lifetime. For some nurses, becoming a leader and mentor is a lifelong transformative process that grows from diverse experience and influential role modelling rather than formal instruction.
Solving the obesity epidemic: voices from the community
Authors: Mama Scherezade K. , Soltero Erica G. , Ledoux Tracey A. , Gallagher Martina R. , Lee Rebecca E.
Published: December 2013

Science and Community: Ending Obesity Improving Health (S&C) aimed to reduce obesity in Houston by developing community partnerships to identify research priorities and develop a sustainable obesity reduction program. Partnership members were recruited from S&C events and invited to participate in in‐depth interviews to gain insight into obesity prevalence, causes, and solutions. Members (n = 22) completed a 60–90‐min in‐depth interview. The interview guide consisted of 30 questions about pressing health problems in the community, potential solutions to health problems and obesity and how the environment has impacted obesity and health behaviors in the community. Interviewees (n = 12 women and 10 men) were mostly Hispanic/Latino (n = 9) and African American (n = 7). Common problems identified were childhood obesity, balancing a healthy diet and physical inactivity. Interviewees identified obesity as a major problem in their communities and cited access to quality food and physical activity resources as both a problem and a solution. Additional emergent themes focused on solutions, including increasing awareness and education, coordinated efforts among organizations and using an ecologic approach to combat obesity. Community insight gleaned from this study may be used to enhance relevance and sustainability of programs developed to reduce obesity and suggests possible avenues for participatory research and intervention.
Nitrergic and purinergic mechanisms evoke inhibitory neuromuscular transmission in the human small intestine
Authors: Gallego D. , Malagelada C. , Accarino A. , De Giorgio R. , Malagelada J. R. , Azpiroz F. , Jimenez M.
Published: December 2013

Background

Inhibitory neuromuscular transmission in the human colon is due to nitrergic and purinergic (P2Y1‐mediated) inputs. The aim of this study was to determine the mechanisms of neuromuscular transmission in different regions of the human small intestine.

Methods

Ileal (n = 6) and jejunal (n = 6) samples underwent histological examination and were studied using sharp microelectrodes in smooth muscle cells and conventional muscle bath techniques. Electrical field stimulation (EFS) was used to stimulate inhibitory neurons.

Key Results

No histological abnormalities were found. Resting membrane potential was −39.7 ± 1.5 and −45.5 ± 2.1 mV in the jejunum and ileum, respectively. Slow waves and spontaneous contractions were recorded at a frequency of about 8–9 and 6–7 cpm in the jejunum and ileum, respectively. In non‐adrenergic, non‐cholinergic conditions, EFS caused an inhibitory junction potential and mechanical relaxation. Both responses were blocked by tissue incubation with the nitric oxide synthase inhibitor (Nω‐nitro‐l‐arginine 1 mM) and the P2Y1 receptor blocker 2′‐deoxy‐N6‐methyladenosine 3′,5′‐bisphosphate tetrasodium salt (MRS2179; 10 μM). Both exogenous addition of sodium nitroprusside (1 μM) and the preferential P2Y1 receptor agonist ADPβS (1 μM) hyperpolarized and relaxed smooth muscle cells. MRS2179 (10 μM) blocked ADPβS‐induced responses.

Conclusions & Inferences

Similar to colon, inhibitory neurotransmission in the human small intestine is mainly mediated by purinergic (via P2Y1 receptors) and nitrergic inhibitory neurotransmission. Similar mechanisms of inhibitory neurotransmission are present in different regions of the human intestine.
QTLmapping for seedling traits associated with low‐nitrogen tolerance using a set of advanced backcross introgression lines of rice
Authors: Zhao Chun‐Fang , Zhou Li‐Hui , Zhang Ya‐Dong , Zhu Zhen , Chen Tao , Zhao Qing‐Yong , Yao Shu , Yu Xin , Wang Cai‐Lin
Published: December 2013

Nitrogen (N) deficiency is a major yield‐limiting factor in rice production. The objective of this study was to identify putativeQTLs for low‐N stress tolerance of rice, using an advanced backcross population derived from crosses between anindicacultivar ‘93‐11’ and ajaponicacultivar ‘Nipponbare’ and genotyped at 250 marker loci. Plant height, maximum root length, root dry weight, shoot dry weight and plant dry weight under two N conditions and their relative traits were used to evaluate low‐N tolerance at the seedling stage. A total of 44QTLs were identified on chromosomes 1, 2, 3, 4, 5, 6, 8 and 9. Eight intervals on five chromosomes were identified to harbour multipleQTLs, suggesting pleiotropism or multigenic effects according to the contributor of alleles. SomeQTLclusters were found in the nearby regions of genes associated with N recycling in rice, indicating that the key N metabolism genes might have effects on the expression ofQTLs. Several uniqueQTLs for relative traits were detected, which suggested the specific genetic basis of relative performance.
Identification and characterization of a novel copper transporter gene family TaCT1 in common wheat
Authors: LI HAOXUN , FAN RENCHUN , LI LIBIN , WEI BO , LI GUOLIANG , GU LIQING , WANG XIANPING , ZHANG XIANGQI
Published: December 2013

Copper is an essential micronutrient for plant growth and development, and copper transporter plays a pivotal role for keeping copper homeostasis. However, little is known about copper transporters in wheat. Here, we report a novel copper transporter gene family, TaCT1, in common wheat. Three TaCT1 homoeologous genes were isolated and assigned to group 5 chromosomes. Each of the TaCT1 genes (TaCT1‐5A, −5B or −5D) possesses 12 transmembrane domains. TaCT1 genes exhibited higher transcript levels in leaf than in root, culm and spikelet. Excess copper down‐regulated the transcript levels of TaCT1 and copper deficiency‐induced TaCT1 expression. Subcellular experiments localized the TaCT1 to the Golgi apparatus. Yeast expression experiments and virus‐induced gene silencing analysis indicated that the TaCT1 functioned in copper transport. Site‐directed mutagenesis demonstrated that three amino acid residues, Met35, Met38 and Cys365, are required for TaCT1 function. Phylogenetic and functional analyses suggested that homologous genes shared high similarity with TaCT1 may exist exclusively in monocot plants. Our work reveals a novel wheat gene family encoding major facilitator superfamily (MFS)‐type copper transporters, and provides evidence for their functional involvement in promoting copper uptake and keeping copper homeostasis in common wheat.
The contributions of interpreters to the development of radical innovations of meanings: the role of ‘Pioneering Projects’ in the sustainable buildings industry
Authors: Jepsen Lisbeth Brøde , Dell'Era Claudio , Verganti Roberto
Published: December 2013

Studies of innovation management have often focused on two domains: technologies and markets. An ever‐increasing standard of living is pushing companies to develop products and services that are not only profitable but also socially responsible. Sustainable housing offers an intriguing empirical setting that allows the investigation of new processes able to support innovations that must be both profitable and socially responsible. Energy‐efficient houses not only require technological changes (new sustainable energy technologies) but also require behavioural changes in consumers' attitudes, decisions and practices about living in sustainable houses. Companies are not only innovative in regard to their own product but apply the entire system of application with which their specific technologies interact. The development of Pioneering Projects requires many skills and competencies that often exceed the capacity and competencies of a single company. In other words, Pioneering Projects are testing grounds for experimentation, where unconventional, temporary partnerships of stakeholders from different industries unite in the development of real market applications. The paper addresses the value of key interpreters in facilitating the development of radical innovations of meanings in the sustainable buildings industry. Specifically, the paper analyses the ability to create value for the Pioneering Projects from the exploration and knowledge diversity of the interpreters and the impact that Pioneering Projects have on the companies' outcomes. Empirical data about Pioneering Projects were collected from two manufacturing companies in Denmark: DOVISTA and Saint‐Gobain Isover.
An inquiry on dimensions of external technology search and their influence on technological innovations: evidence fromChinese firms
Authors: Li‐Ying Jason , Wang Yuandi , Salomo Søren
Published: December 2013

A central part of technological innovation for industrial firms involves search for new external knowledge. A well‐established stream of literature on firms' external knowledge search has demonstrated that firms investing in broader search may have a great ability to innovate. In this paper, we explore the influences of technology search on firms' technological innovation performance along three distinctive dimensions: technical, geographic, and temporal dimensions, using a unique panel data set containing information onChinese firms that were active in technology in‐licensing and patenting during the period 2000–2009. Our findings reveal thatChinese firms' technological innovation performances are related to external technology search in quite different ways from the ones suggested in the extant literature using evidence from developed countries. We find thatChinese firms searching ‘locally’ along the technical dimension have better technological innovation performance than those searching ‘distantly’. However, when aChinese firm in‐license relatively old (mature) technologies or those from geographically nearby areas, it will be less bounded to searching familiar technical knowledge.
The competitiveness of China's Leading Regions: Benchmarking Their Knowledge‐based Economies
Authors: Huggins Robert , Luo Shougui , Thompson Piers
Published: December 2013

China's spectacular economic growth has been spatially uneven, with much development occurring in eastern coastal areas. In particular, three metropolitan ‘super‐regions’ have become China's most competitive knowledge‐based economies, consisting of the Pearl River Delta, the Yangtze River Delta, and the Bohai Gulf Region. This paper benchmarks the competitiveness of these regions, with a view to exploring which region is best positioned to become the most dominant knowledge‐based economy over time. Through the theoretical lens of dynamic comparative advantage, it is shown that each region has hugely increased its competitiveness through improvements in the capacity to absorb and diffuse knowledge. It is further shown that due to multi‐dimensional advantages the Yangtze River Delta, incorporating the Shanghai metropolis, is best positioned to become the dominant hub of China's future knowledge economy. It is concluded that China's leading regions will require further economic policy adjustments in order to secure their future competitiveness.
Robust Tracking Control of a Prosthesis Test Robot
Authors: Richter Hanz , Simon Dan
Published: December 2013

This paper develops a passivity-based robust motion controller for a robot used in prosthetic leg performance studies. The mathematical model of the robot and passive prosthesis corresponds to a three degree-of-freedom, underactuated rigid manipulator. A form of robotic testing of prostheses involves tracking reference trajectories obtained from human gait studies. The robot presented in this paper emulates hip vertical displacement and thigh swing, and we consider a prosthesis with a passive knee for control development. The control objectives are to track commanded hip displacements and thigh angles accurately, even in the presence of parametric uncertainties and large disturbance forces arising from ground contact during the stance phase. We develop a passivity-based controller suitable for an underactuated system and compare it with a simple independent-joint sliding mode controller (IJ-SMC). This paper describes the mathematical model and nominal parameters, derives the passivity-based controller using Lyapunov techniques and reports success in real-time implementation of both controllers, whose advantages and drawbacks are compared.
Frictional Behaviors of a Mild Steel and a TRIP780 Steel Under a Wide Range of Contact Stress and Sliding Speed
Authors: Kim Chongmin , Lee Jeong-Uk , Barlat F. , Lee Myoung-Gyu
Published: December 2013

The application of advanced high-strength steels (AHSS) generally makes it necessary to use higher tool-sheet contact pressures compared with those used for forming low-strength steel, and it leads to significant changes in frictional behavior, which in turn change the final product characteristics. In order to understand frictional behaviors between steel sheets and tool materials under high contact stresses present in real stamping conditions, a novel friction tester was conceived, fabricated, and used. This tester can generate high normal loads, as high as 625 MPa, whereas traditional friction testers were limited to 10 MPa or less. A mild steel and a TRIP780 steel were paired with Cr-coated D2 tool steel, and friction behaviors were observed under various conditions, including the use of two lubricants, wide ranges of sliding speeds, and normal contact stresses. The coefficient of friction (COF) decreased at a low contact pressure as the sliding velocity increased. The contact pressure had a significant effect, albeit too complex to be explained by simple models. It was also evident that lubricant effects must be studied coupled with the contact pressure and sliding speed. In a nonlubricated condition at normal stresses roughly half of the steel’s yield strength, the friction event caused plastic deformation that reached up to 0.2 mm from the surface. In this deformed region, the amount of retained austenite in the TRIP steel decreased substantially, and significant residual compressive stress, reaching 350 MPa, also developed in the ferrite phase (plus a minor amount of martensite, which is undistinguishable from ferrite by the X-ray diffraction method used herein). The magnitude of change of friction constant due to changes in contact conditions was enough to significantly affect springback of automotive body panels.
In situ synchrotron based x-ray techniques as monitoring tools for atomic layer deposition
Authors: Devloo-Casier Kilian , Ludwig Karl F. , Detavernier Christophe , Dendooven Jolien
Published: December 2013

Atomic layer deposition (ALD) is a thin film deposition technique that has been studied with a variety of in situ techniques. By exploiting the high photon flux and energy tunability of synchrotron based x-rays, a variety of new in situ techniques become available. X-ray reflectivity, grazing incidence small angle x-ray scattering, x-ray diffraction, x-ray fluorescence, x-ray absorption spectroscopy, and x-ray photoelectron spectroscopy are reviewed as possible in situ techniques during ALD. All these techniques are especially sensitive to changes on the (sub-)nanometer scale, allowing a unique insight into different aspects of the ALD growth mechanisms.
The preparation and properties of cobalt(II) tellurates
Authors: Sikač Jiří , Jenšovský Lubor
Published: December 2013

Cobalt(II) tellurates with the composition CoTeO4, CoTeO4.1/2 H2O and Co3TeO6 were prepared. The first two are cubic with octahedral coordination around the cobalt atom and with TeO6 octahedra joined at the edges. In Co3TeO6, which is isostructural with Ni3TeO6, the TeO6 octahedra are isolated. At least one cobalt atom is tetrahedrally coordinated by oxygen atoms. The high values of the temperature independent paramagnetism, 11 m3 kg-1, and the Weiss constant, Θ = -64 K, indicate marked magnetic exchange interaction. The thermal decomposition of all three tellurates leads to formation of cobalt tellurates and finally to CoO and TeO2. At laboratory temperature all three substances are paramagnetic with μeff values corresponding to divalent cobalt.
Aminolysis of N-acyllactams
Authors: Stehlíček Jaroslav , Šebenda Jan
Published: December 2013

The overall second-order rate constants of aminolysis of N-benzoyllactams of different ring size, the rate constants of aminolysis of N,N'-isophthaloyl- and N,N'-terephthaloylbis(6-hexanelactam) to the first and second stages and the ratio of splitting of the exocyclic and endocyclic amide bond by octylamine were determined in THF at 50 °C. The effect of the type of amine and medium on the rate of aminolysis was examined.
Analogues of androgens with the open ring A
Authors: Kasal Alexander
Published: December 2013

The synthesis of the A-nor-3,5-seco analogue of dehydroepiandrosterone (VII) is based on different acylation and oxidation rates of the hydroxyl groups in A-nor-3,5-seco-5-androsten-3,17β-diol (I). The methyl ester of 5-oxo-17β-pivaloyloxy-A-nor-3,5-secoandrostan-3-oic acid (X), accessible from testosterone pivalate, was converted to 4,5-seco-analogues of testosterone and methyltestosterone (compounds XVII and XXIII).
Hog pancreatic α-amylase peptides from tryptic digest of isozyme AII
Authors: Meloun Bedřich , Kluh Ivan , Morávek Ladislav
Published: December 2013

Peptides isolated from the tryptic digest of the S-sulfo derivative of isozyme AII by gel filtration on Sephadex columns, paper chromatography and electrophoresis were sequenced by the phenylisothiocyanate method. The sequential regions determined account for 319 nonoverlapping amino acid residues in 46 peptides. Sequences around methionine residues and problems of isolation of amylase isozymes are discussed.
New catalysts for Belousov-Zhabotinskii reaction
Authors: Handlířová Marie , Tockstein Antonín
Published: December 2013

It was found that cobalt, nickel and copper as central ions in complexes with various amines can act as catalysts of the Belousov-Zhabotinskii reaction. Also sole 8-hydroxyquinoline is a catalyst.
Conductivity study of association of K2Mg[Fe(CN)6], K2Ca[Fe(CN)6] and K2Ba[Fe(CN)6] in aqueous solutions
Authors: Fidler Alois , Čeleda Jiří
Published: December 2013

The stability constants, Kp0, of ion pairs M2+.[Fe(CN)6]4- and their equivalent conductivities, λp0, at infinite dilution were evaluated by means of two-parameter fitting from the conductivities measured in very diluted aqueous solutions of double hexacyanoferrates of the type K2M(II).[Fe(CN)6] at 25 °C with the use of the limiting Debye-Huckel formula for ionic activity coefficients and Onsager limiting formula for the conductivity of strong electrolytes extended to electrolyte mixtures. Thus, Kp0 = 0.66, 0.72, and 0.76 . 104 dm3/mol and λp0 = 46, 49, and 53 S cm2 /val, respectively.
Comparison of the reactions of ferric ions with Chromazurol S, Eriochromazurol B and Eriochromcyanine R in the presence of surface active substances and spectrophotometric determination of Fe(III)-ions with Chromazurol S-cetylpyridinium bromide system
Authors: Kubáň Vlastimil , Gotzmannová Dagmar
Published: December 2013

The spectrophotometric methods of determining Fe(III) ions with Chromazurol S, Eriochromazurol B and Eriochromcyanine R in the presence of cationic, anionic and nonionic tensides were compared using the basic optical and statistical parameters. A method was proposed and developed for the determination of Fe(III) ions using Chromazurol S in blood serum and plasma at pH 4.7-5.0 in a medium of 2 . 10-4M cetylpyridinium bromide and 0.1M pyridine buffer and at pH 6.0-6.5 in a medium of 2 . 10-3M cetylpyridinium bromide and 0.1M hexamethylenetetramine buffer with molar absorption coefficients of 1.31 . 105 and 1.40 . 105, respectively. The determination is sufficiently specific even at pathological concentrations of the other serum components.
13C NMR study of 3-(X-benzal)phthalides and 2-(X-benzal)-1,3-indanediones
Authors: Solčániová Eva , Hrnčiar Pavol , Liptaj Tibor
Published: December 2013

13C NMR spectra of 14 derivatives of 3-(X-benzal)phthalides (I) and 10 derivatives of 2-(X-benzal)-1,3-indanediones (II) were investigated. The correlation of 13C chemical shifts of carbon atoms of the phthalide ring with σ-constants showed that the electronic effect of substituents was transmitted from the benzylidene group of 3-(X-benzal)phthalides on the chemical shift of the carbonyl group not only through oxygen, but also through the aromatic ring of the phthalide moiety. The transmission of substituent effects in 2-(X-benzal)-1,3-indanediones on the chemical shift of the carbonyl groups was more pronounced on the carbonyl, which is in the trans-arrangement with respect to the aryl group. This phenomenon was also observed at carbon atoms of the benzene ring of the indanedione moiety closer to the trans-CO group.
13C NMR study of tetrosides and their derivatives
Authors: Urban Jiří , Marek Miroslav , Jarý Jiří , Sedmera Petr
Published: December 2013

13C NMR spectra of 23 tetrose derivatives were assigned. The C(1) resonates below 103 ppm with compounds having cis-arranged substituents at C(1) and C(2) and above 106 ppm with compounds having trans-arrangement. The carbon-13 chemical shifts are mainly influenced by the 1,2-interaction. The magnitudes of direct coupling constants 1J(C(1), H) cannot be used for the determination of the anomeric configuration.
Enantioselective hydrosilylation of tert-butyl phenyl ketone by diphenylsilane catalysed by [Rh{(-)-DIOP}2]+ClO4-
Authors: Kolb Ivan , Hetflejš Jiří
Published: December 2013

Kinetics of the title reaction has been studied by the method of initial reaction rates. In the presence of free chiral ligand the hydrosilylation was found to be first order in the catalyst and in the ketone and fractional order in the organosilicon hydride. The rate data and the results of spectroscopic study of interaction of diphenylsilane with the rhodium complex have been interpreted in terms of a reaction model involving formation of the corresponding cationic silyl(hydrido)rhodium complex followed by interaction of the ketone with this complex in the rate determining step. The results are confronted with those obtained for the analogous reaction catalysed by [Rh(1,5-COD)(-)-DIOP]+ClO4-.
Reactions of ethyl 2-(4-chlorophenyl)-4H-furo[3,2-b]pyrrole-5-carboxylate
Authors: Krutošíková Alžbeta , Kováč Jaroslav , Chudobová Mária , Ilavský Dušan
Published: December 2013

Reduction, hydrolysis, N-alkylation and N-acylation of 2-(chlorophenyl)-4H-furo[3,2-b]pyrrole-5-carboxylate are described. The HMO method was used to calculate compounds I, II, IV and X as model substances furo[3,2-b]pyrrole, 2-phenylfuro[3,2-b]pyrrole and methyl furo[3,2-b]pyrrole-5-carboxylate. The stability and reactivity of the synthesized compounds are discussed on the basis of indexes of chemical reactivity.
Synthesis of 2-amino-6-substituted 5,6-dihydro-4H-1,3-thiazin-4-ones from α,β-unsaturated acyl isothiocyanates
Authors: Dzurilla Milan , Kristian Pavol , Kutschy Peter
Published: December 2013

Reactions of α,β-unsaturated acyl isothiocyanates with primary and secondary amines were studied. Thioureas formed from the weakly basic secondary amines easily underwent cyclization in hot benzene to yield 2,6-disubstituted 5,6-dihydro-4H-1,3-thiazin-4-ones. Their structure was proved by IR, 1H NMR and mass spectral methods.
Biological activities and protracted action of carba-analogues of deamino-oxytocin with O-methyltyrosine in position 2
Authors: Barth Tomislav , Slaninová Jiřina , Lebl Michal , Jošt Karel
Published: December 2013

The biological potency and the duration of the effect of two analogues of deamino-oxytocin, having the disulfide bond substituted by a thioether group and the tyrosine residue replaced by O-methyltyrosine, were compared in the uterotonic and galactogogic assay in vivo. [2-O-Methyltyrosine]deamino-6-carba-oxytocin had a very low formal elimination constant (i.e. strongly protracted action) in the uterotonic assay.
The effect of decationation of hydroxylated HNaY zeolites on their interaction with ethylene and propylene. hydrogen complexes, oligomeration and isotope exchange
Authors: Kubelková Ludmila , Nováková Jana , Dolejšek Zdeněk , Jírů Pavel
Published: December 2013

The effect of decationation on the interaction of propylene and ethylene with the hydroxylated forms of HNaY zeolites has been studied. The compounds formed in the zeolite cavities were studied using their infrared spectra, the composition of the gaseous phase was followed by mass spectrometry. The results showed that among factors affecting the interaction with propylene properties of hydroxyl groups play the decisive role. With the increasing decationation of the zeolite the strength of the OH bond in the hydrogen complex of the large-cavity hydroxyls with propylene decreased and the rate of propylene oligomeration at 310 K as well as the isotope exchange rate of propylene-d6 with the zeolite hydroxyls at 570 K increased. The propylene isotope exchange reaction proceeded by the multiple-step mechanism. In the case of ethylene only the physical sorption with a non-specific character was observed at 310 K. The adsorbed amount increased with the increasing content of Na+ ions in the zeolite (with the decreasing decationation). A part of the adsorbed molecules formed hydrogen complexes with hydroxyls of large cavities. The observed lower weakening of the OH bond was in agreement with the lower basicity of ethylene if compared with propylene. The isotope exchange of ethylene-d4 with the zeolite hydroxyls proceeded by a single-step mechanism, it had an autocatalytic character and its rate was 70 times lower than that of the isotope exchange of propylene-d6 with OH.
Preparation of some trimethyl- and methylethylbiphenyls and reactivity of aromatic hydrocarbons in the Gomberg reaction
Authors: Novrocík Jan , Novrocíková Marta , Titz Miloš
Published: December 2013

Trimethyl- and methylethylbiphenyls with the alkyl groups in the both phenyl rings have been prepared by the Gomberg reaction and identified by the capillary gas-liquid chromatography. Depending on choice of the aromatic hydrocarbon either individual isomers or their mixtures (three at the most) have been obtained which were contaminated with compounds of diarylmethane type in many cases. The methylethylbiphenyls have only been prepared as mixtures contaminated with diarylmethanes. These side products have been prepared by independent syntheses. A method has been developed for isolation and separation of mixtures of trimethyl- and methylethylbiphenyls from the reaction products containing tarry products. The method is suitable for preparation of small amounts of some analytical standards. The HMO method has been used for calculation of values of the radical superdelocalizabilities at individual centres in the molecules of o-, m- and p-xylene, toluene and ethylbenzene, and these values have been compared with composition of the Gomberg reaction products from these hydrocarbons. The competitive technique has been used for comparison of the reactivities of the mentioned aromatic substrates in the Gomberg reactions.
Ab initio study of the (BH)2 dimer
Authors: Urban Miroslav , Hrivnáková Soňa , Hobza Pavel
Published: December 2013

The total interaction energy between two BH molecules was calculated as a sum of the SCF and correlation interaction energies. The latter was obtained either semiempirically or by the 2nd and 3rd order perturbation theory. It appeared to be the main contribution to the total interaction energy with some geometries. Important differences in the SCF interaction energy of different geometrical configurations of the dimer were explained by the utilization of higher terms of the Coulomb energy multipole expansion. Unexpectedly the geometry of highest stability does not correspond to the linear arrangement of the dimer but rather to the T-shaped structure.
A simple way of calculation of spin densities from RHF wave function
Authors: Tiňo Jozef , Klimo Viliam , Mestechkin Michael M.
Published: December 2013

From study of non-stability of the RHF method a formula has been derived for addition of the spin-polarization component to the RHF spin densities. Spin densities of several radicals have been calculated by the INDO method. The results are compared with those of RHF CI and PUHF, the agreement being very good.
Kinetics and mechanism of oxidation of V(II) ions with trichloroacetic acid
Authors: Adamčíková Ľubica
Published: December 2013

The kinetics and mechanism of the redox reaction of V(II) ions with trichloroacetic acid were studied in the medium of 0.04-2.0M-HClO. The results of kinetic measurements were compared with the analogous oxidation of U(III) ions with trichloroacetic acid, and the exchange rate constant for the reaction U3+ + *U4+ → U4+ + *U3+ was calculated. The influence of binary mixtures on the kinetic parameters of the reaction and the application of the Marcus' equation show that the oxidation of V2+ions with trichloroacetic acid proceeds by an outer-sphere mechanism.
Spectrophotometric study of the interaction of ferric ions with Chromazurol S in the presence of cetylpyridinium bromide
Authors: Kubáň Vlastimil , Gotzmannová Dagmar , Koch Siegfried
Published: December 2013

The properties of the Fe(III)-Chromazurol S-cetylpyridinium bromide system were found by graphical and numerical interpretation of the absorbance curves using a desk-top calculator controlled SuperscanTM3 spectrophotometer and programs for the direct recording and treatment of experimental data. The composition and probable structure of the ternary species FeL.2 T and Fe(LH)2.n T under various experimental conditions and the probable reaction mechanism of its formation are discussed.
13C and 15N NMR studies of 2,3,4-pentanetrione 3-phenylhydrazone, dimethyl 2-phenylhydrazonopropanedioate and ethyl 2-phenylhydrazono-3-oxobutanoate
Authors: Lyčka Antonín
Published: December 2013

The 13C AND 15N NMR spectra of 2,3,4-pentanetrione 3-phenylhydrazone, dimethyl 2-phenylhydrazonopropanedioate and ethyl 2-phenylhydrazono-3-oxobutanoate have been measured in deuteriochloroform at 30 °C. The carbon and nitrogen signals have been assigned, and the chemical shifts and coupling constants 1J(CH) have been determined. Ethyl 2-phenylhydrazono-3-oxobutanoate has been measured first as the (E) isomer and then as a mixture of the (E) and (Z) isomers. This compound has also been prepared with one or two 15N atoms enabling determination of absolute values of the coupling constants nJ(15N13C) and 1J(15N15N), respectively.
N-alkylation of 3,5-dicyano-2,4,4,6-tetramethyl-1,4-dihydropyridine with some α,ω-dihalogeno-N-alkenes
Authors: Paleček Jaroslav , Kopecký Jaroslav , Kuthan Josef
Published: December 2013

Bis-1,4-dihydropyridine derivatives Vc-Vf can be obtained on reaction of α,ω-diiodo-n-alkanes with the sodio derivative II of compound I, while α,ω-dibromo-n-alkanes give a mixture of compounds Vc-Vf and IVc-IVf. Analogous products IVa and Va,b could not be prepared, owing to the predominating and disturbing elimination reactions. Spectral characteristics (UV, IR, NMR and mass spectra) of the compounds obtained are confronted with their structure.
The preparation of 3-amino-3-deoxy-1,2-O-isopropylidene-α-L-erythrofuranose, 3-amino-3-deoxy-1,2-O-isopropylidene-β-D-threofuranose and their derivatives
Authors: Jarý Jiří , Masojídková Milena , Kozák Ivan , Marek Miroslav , Staněk Jan
Published: December 2013

The title amino derivatives VI and XIV were prepared by nucleophilic substitution of p-toluenesulfonyl derivatives II and XVII with sodium azide or hydrazine and subsequent reduction. Nucleophilic substitution of compounds II and XVII with sodium benzoate was also investigated. The 1H NMR spectra of the substances prepared are discussed.
Analysis of adsorption kinetics on zeolites under nonisothermal conditions. I. Analytical solution of the problem
Authors: Kočiřík Milan , Smutek Miloš , Bezus Arkadij , Zikánová Arlette
Published: December 2013

Mass and heat balance equations for a zeolitic compact in the form of an infinite plate were solved and theoretical equations for the kinetic curves were discussed. Besides the general solution obtained by the residuum method, approximate solutions for limiting cases were derived.