bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the growth mechanisms of nanocrystalline diamond films
Authors: Kulisch Wilhelm , Popov Cyril 
Published: February 2006

AbstractNanocrystalline diamond/amorphous carbon (NCD/a‐C) composite films have been deposited by microwave chemical vapour deposition from methane‐rich CH4/N2 mixtures and characterized carefully by a variety of methods with respect to morphology and structure, composition, crystallinity, and bonding environment. The films consist of diamond nanocrystals of 3–5 nm diameter, which are embedded in an amorphous carbon matrix of 1–1.5 nm width. The matrix is a mixture of sp2 (20–30%) and sp3 bonded carbon and contains about 20% of hydrogen, mostly bonded to sp3 carbon atoms. New experiments are reported carried out to study the nucleation and the growth on a microscopic and macroscopic scale. No differences to standard deposition of polycrystalline diamond (PCD) with respect to the nucleation step were observed, i.e. in order to achieve a high nucleation density an appropriate substrate pretreatment is required. In contrast, there are strong differences in the growth mechanisms of NCD and PCD, respectively. Most importantly, there is a high rate of secondary nucleation observed in NCD deposition. On a macroscopic scale, this leads to a spherulitic growth of NCD films. The microscopic mechanisms leading to this high rate of secondary nucleation are discussed in terms of the deposition parameters leading to NCD growth, namely gas phase constituents and composition, pressure, substrate temperature, and bias voltage. Defect formation under the special conditions of NCD deposition is identified as a major reason. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of adsorbates on the piezoresponse of KNbO3
Authors: Peter F. , Kubacki J. , Szot K. , Reichenberg B. , Waser R. 
Published: February 2006

AbstractWe report on the reduction of piezoresponse in KNbO3 originating from a surface layer. An analysis with surface sensitive measurements shows that this layer consists of chemisorbates and physisorbates. Heating the sample under ultra high vacuum conditions removes the surface layer on the perovskite to a large extend. This treatment has a drastic effect on the piezoresponse as the potential difference applied to the sample is no longer reduced by a voltage drop across the adsorbate layer, leading to a higher electric field compared to the case with an adsorbate layer. Experiments and simulations are presented confirming this postulation on KNbO3. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Variability in riverine ecosystems
Authors: Thoms Martin C. 
Published: February 2006

AbstractRiverine ecosystems are complex features of the landscape displaying structures and processes that reflect the influence of many variables at a range of scales. Thus, the physical, chemical and ecological character of riverine ecosystems differs between them and may change over time, often at different rates and in different ways. In addition, the structure and function of riverine ecosystems also varies downstream. Rivers are process‐response systems whereby changes to discharge and sediment load induce a range of ecosystem responses. Those river systems subject to highly variable process regimes may be expected to exhibit enhanced levels of complexity and display processform relationships commensurate of this variability, where both equilibrium and non‐equilibrium conditions can exist. The process‐form relationships and interactions between the physical, chemical and ecological templates of highly variable riverine ecosystems challenge some of the accepted wisdoms of river system functioning. This paper introduces some of these challenges and the general theme of the ten papers of this special issue of River Research and Applications. As a collective they apply an interdisciplinary approach to the study and management of variability in riverine ecosystems and in doing so advance our knowledge of these systems. Copyright © 2006 John Wiley & Sons, Ltd.
The riverine ecosystem synthesis: biocomplexity in river networks across space and time
Authors: Thorp James H. , Thoms Martin C. , Delong Michael D. 
Published: February 2006

AbstractWe propose an integrated, heuristic model of lotic biocomplexity across spatiotemporal scales from headwaters to large rivers. This riverine ecosystem synthesis (RES) provides a framework for understanding both broad, often discontinuous patterns along longitudinal and lateral dimensions of river networks and local ecological patterns across various temporal and smaller spatial scales. Rather than posing a completely new model, we arrange a conceptual marriage of eco‐geomorphology (ecological aspects of fluvial geomorphology) with a terrestrial landscape model describing hierarchical patch dynamics. We modify five components of this terrestrial model for lotic ecosystems: (1) nested, discontinuous hierarchies of patch mosaics; (2) ecosystem dynamics as a composite of intra‐ and inter‐patch dynamics; (3) linked patterns and processes; (4) dominance of non‐equilibrial and stochastic processes; and (5) formation of a quasi‐equilibrial, metastable state. Our conceptual model blends our perspectives on biocomplexity with aspects of aquatic models proposed from 1980–2004.Contrasting with a common view of rivers as continuous, longitudinal gradients in physical conditions, the RES portrays rivers as downstream arrays of large hydrogeomorphic patches (e.g. constricted, braided and floodplain channel areas) formed by catchment geomorphology and climate. The longitudinal distribution of these patches, which are identifiable using standard geomorphic techniques, varies amongst rivers and is difficult to forecast above ecoregional scales. Some types of hydrogeomorphic patches may reoccur along this downstream passage. Unique ecological ‘functional process zones’ are formed by individual types of hydrogeomorphic patches because of physiochemical habitat differences which affect ecosystem structure and function.The RES currently includes 14 tenets predicting how patterns of individual species distributions, community regulation, lotic ecosystem processes, and floodplain interactions will vary over spatiotemporal scales, especially as they relate to the functional process zones formed by hydrogeomorphic differences in the river network. Copyright © 2006 John Wiley & Sons, Ltd.
Relationships between flow variability and macroinvertebrate assemblage composition: data from four Australian dryland rivers
Authors: Sheldon Fran , Thoms Martin C. 
Published: February 2006

AbstractAustralian dryland rivers have distinctive ecologies, intimately linked to their variable flows. The contrasting states of flood and drought mean that dryland rivers fluctuate between being highly connected (during floods: low fragmentation) to being highly disconnected (during droughts: high fragmentation) with the degree of connection between waterbodies on a spatial scale and the time since last connection on a temporal scale strongly influencing community composition. Flow regulation reduces the frequency and duration of flooding, thereby decreasing flow variability and imposing stable low flow conditions and high connectivity between waterbodies. Using macroinvertebrate assemblage data from four Australian dryland rivers (River Murray, Darling River, Cooper Creek and Diamantina River), we calculated various indices of flow variability from 30‐year hydrographs and assessed how well long‐term flow variability, and therefore variable levels of habitat connection, could explain broad patterns of macroinvertebrate assemblage composition. Where hydrological connection between sites was strong (River Murray pool sites) there was extreme similarity between assemblages at each site. Also, for sites where hydrological disconnection was extreme there was similarity between assemblages. There were strong associations between the complex measures of flow variability and the assemblage composition of the four rivers, suggesting that flow variability, and therefore, variable levels of habitat connectivity, may be strong determinants of broad‐scale assemblage composition in dryland rivers. Copyright © 2006 John Wiley & Sons, Ltd.
Managing river flows for hydraulic diversity: an example of an upland regulated gravel‐bed river
Authors: Dyer Fiona J. , Thoms Martin C. 
Published: February 2006

AbstractThe establishment of ecologically responsive environmental flow regimes is a challenge for river managers. Biological communities in river environments are partly constrained by hydraulic characteristics such as water depth, flow velocity and turbulence, so a key step in understanding the links between discharge and biotic response is to relate discharge and hydraulic character. This paper explores the nature of the relationship observed between discharge and hydraulic character in the Cotter River, Australia. Surface flow types or hydraulic patches, expressing a variety of hydraulic characteristics, were mapped in six reaches in this upland gravel‐bed river, during 18 different flow releases ranging from 8 to 260 ML per day. The distributions of these hydraulic patches were variable, both spatially and over time. The patches represent hydraulic habitats (of varying depth, flow velocity and turbulence) the diversity of which may contribute to in‐stream biodiversity. The study identified a range of flow releases that produce the greatest in‐stream diversity of hydraulic habitats, which, if included in managed release strategies, potentially benefits in‐stream biodiversity. Copyright © 2006 John Wiley & Sons, Ltd.
The real river management challenge: integrating scientists, stakeholders and service agencies
Authors: Rogers Kevin H. 
Published: February 2006

AbstractThe experience of river scientists leads them to propose ecosystem variability as a central theme in management. The real challenge however lies in developing collective understanding, and integration, within and between scientists, citizens and management agencies. The prevailing view of scientists as experts who solve environmental problems is fallacious. A broad societal response, supported by humble public service agencies and scientists in the service of society, is more likely to succeed. This paper proposes a framework for structuring the science/management/society partnerships, and is based on experiences from managing rivers flowing through the Kruger National Park, South Africa. Scientists need to place between‐discipline communication, constructive synthesis of their collective understanding and diffusion of this understanding into civil society, much higher on their collective agenda. Entering problem solving situations as co‐learners, rather than experts, facilitates partnership building. Managers need to focus on: (1) preparing society to engage the knowledge, the problem and the solutions needed to achieve some collectively defined set of future conditions; (2) actively engage scientists in the development of technology for altering patterns of resource use and (3) undertake actions needed to achieve the desired future distribution of the costs and benefits of resource use in society. Managers have a very limited tool box with which to work, and modern society has largely transferred the risk of failure to them. Society therefore needs to accept more responsibility in these partnerships of co‐operative decision‐making. It should engage in them with a ‘public good’ ethic, a vision for a shared future, and an acceptance that resource and technological limits ultimately determine the distribution of costs and benefits of ecosystem services. Successful partnerships are based on adaptive management processes driven by consensus decision‐making to ensure better distribution of knowledge, risks, humility and rewards in common property resource management. To achieve this we need to learn new ways to manage, while managing new ways to learn. Three models, social learning, learning communities and learning organizations, provide focus for learning. Copyright © 2006 John Wiley & Sons, Ltd.
Stapler Hepatectomy is a Safe Dissection Technique: Analysis of 300 Patients
Authors: Schemmer Peter , Friess Helmut , Hinz Ulf , Mehrabi Arianeb , Kraus Thomas W. , Z’graggen Kaspar , Schmidt Jan , Uhl Waldemar , Büchler Markus W. 
Published: February 2006

AbstractBackgroundIn many surgical procedures, stapling devices have been introduced for safety and to reduce the overall operative time. Their use for transection of hepatic parenchyma is not well established. Thus, the feasibility of stapler hepatectomy and a risk analysis of surgical morbidity based on intraoperative data have been prospectively assessed on a routine clinical basis.Materials and MethodsFrom October 1, 2001, to January 31, 2005, a total of 416 patients underwent liver resection in our department. During this period endo GIA vascular staplers were used for parenchymal transection in 300 cases of primary (22%) and metastatic (57%) liver cancer, benign diseases (adenoma, focal nodular hyperplasia [FNH], cysts) (14%), gallbladder carcinoma (2%), and other tumors (5%). There were 193 (64%) major resections (i.e., removal of three segments or more) and 107 minor hepatic resections. Additional extrahepatic resections were performed in 44 (15%) patients.ResultsMedian values for operative time and intraoperative hemorrhage were 210 minutes and 700 ml, respectively. Further, transfusion of RBC and FFP was needed in 17% and 11% of patients, respectively. A postoperative ICU stay for >2 days was required in 18% of patients. The median postoperative hospital stay was 10 days (IQR 8–14 days). The most frequent surgical complications were bile leak (8%), wound infection (3%), and pneumothorax (2%). In 7% of cases after stapler hepatectomy a relaparotomy was necessary. Treated medical complications were pleural effusion (7%), renal insufficiency (5%), and cardiac insufficiency (3%). Risk assessment revealed that both operative time and indication for resection had significant impact on surgical morbidity. Mortality (4%) and morbidity (33%) were comparable to other high‐volume centers performing conventional liver resection techniques.ConclusionIn conclusion, stapler hepatectomy can be used in a routine clinical setting with a low incidence of surgical complications.
Bilateral Adrenalectomy for Ectopic Cushing’s Syndrome—Discussions on Technique and Indication
Authors: Hellman Per , Linder Fredrik , Hennings Joakim , Hessman Ola , Eriksson Barbro , Örlefors Håkan , Åkerström Göran 
Published: February 2006

AbstractBackgroundTumors producing adrenocorticotropic hormone (ACTH) or corticotropin releasing hormone (CRH) often remain undiagnosed until severe Cushing’s syndrome appears, and it may be difficult to distinguish from Cushing’s syndrome due to pituitary tumors. Many patients suffer from disease spread, with metastases in the liver or other locations, and the main symptoms may be mineral disturbances, diabetes mellitus, or psychological symptoms from the severe hypercortisolism. Bilateral adrenalectomy may alleviate this situation, but is sometimes a troublesome procedure in these severely ill patients.MethodsWe have retrospectively investigated 8 patients with ectopic Cushing’s syndrome who have undergone bilateral adrenalectomy at the University Hospital in Uppsala. In addition, another 5 patients who underwent bilateral adrenalectomy for other reasons (recurrent pituitary Mb Cushing or bilateral hyperplasia) were scrutinized for technical considerations. Indications, timing of surgery, and operative procedures were studied to identify signs that may support our approach to management in the future.ResultsCurative surgery was not possible in any of the cases with ectopic Cushing’s syndrome. Of the 13 operated patients, handport‐assisted laparoscopic adrenalectomy was successfully performed bilaterally in 5 patients and unilaterally in combination with contralateral open surgery in 1 patient; conventional open surgery was performed on 7 patients, 3 of which were conversions from intitial handport‐assisted procedures. Non‐fatal complications occurred in 4 out of 10 patients.ConclusionsWe conclude that bilateral handport‐assisted laparoscopic adrenalectomy is safe, and that all surgical techniques in these severely ill patients may be troublesome and technically demanding. Early surgical intervention may reduce the technical disadvantages. Moreover, bilateral adrenalectomy can substantially reduce the symptoms of Cushing’s syndrome, although effects on mortality are not obvious.
Mimicking catalase and catecholase enzymes by copper(II)-containing complexes
Authors: Szilágyi István , Horváth László. , Labádi Imre , Hernadi Klara , Pálinkó István , Kiss Tamás 
Published: February 2006

AbstractAn imidazolate-bridged copper(II)-zinc(II) complex (Cu(II)-diethylenetriamino-μ-imidazolato-Zn(II)-tris(2-aminoethyl)amine perchlorate (denoted as “Cu,Zn complex”) and a simple copper(II) complex (Cu(II)-tris(2-aminoethyl) amine chloride (“Cu-tren”) were prepared and immobilised on silica gel (by hydrogen or covalent bonds) and montmorillonite (by ion exchange). The immobilised substances were characterised by FT-IR spectroscopy and their thermal characteristics were also studied. The obtained materials were tested in two probe reactions: catalytic oxidation of 3,5-di-tert-butyl catechol (DTBC) (catecholase activity) and the decomposition of hydrogen peroxide (catalase activity). It was found that the catecholase activity of the Cu,Zn complex increased considerably upon immobilization on silica gel via hydrogen bonds and intercalation by ion exchange among the layers of montmorillonite. The imidazolate-bridged copper(II)-zinc(II) complex and its immobilised versions were inactive in hydrogen peroxide decomposition. The Cu(II)-tris(2-aminoethyl)amine chloride complex displayed good catalase activity; however, immobilisation could not improve it.
Blow-up of regular submanifolds in Heisenberg groups and applications
Authors: Magnani Valentino 
Published: February 2006

Abstract
We obtain a blow-up theorem for regular submanifolds in the Heisenberg group, where intrinsic dilations are used. Main consequence of this result is an explicit formula for the density of (p+1)-dimensional spherical Hausdorff measure restricted to a p-dimensional submanifold with respect to the Riemannian surface measure. We explicitly compute this formula in some simple examples and we present a lower semicontinuity result for the spherical Hausdorff measure with respect to the weak convergence of currents. Another application is the proof of an intrinsic coarea formula for vector-valued mappings on the Heisenberg group.
On some new spectral estimates for Schrödinger-like operators
Authors: Levin Daniel 
Published: February 2006

Abstract
We prove the analog of the Cwikel-Lieb-Rozenblum estimate for a wide class of second-order elliptic operators by two different tools: Lieb-Thirring inequalities for Schrödinger operators with matrix-valued potentials and Sobolev inequalities for warped product spaces.
Kinetic characterization of ATP diphosphohydrolase and 5′‐nucleotidase activities in cells cultured from submandibular salivary glands of rats
Authors: Henz Sandra Liana , Ribeiro Cristiane Guimarães , Rosa Aline , Chiarelli Rafael Augusto , Casali Emerson André , Sarkis João José Freitas 
Published: February 2006

AbstractThe participation of ecto‐ATP diphosphohydrolase (CD39; ecto‐NTPDase) and ecto‐5′‐nucleotidase (CD73) activities in the nucleotide hydrolysis by salivary gland cells from rats was evaluated. We investigated the biochemical characteristics of these ectoenzymes in cells cultured from submandibular salivary glands of rats. TheVmaxfor the hydrolysis of ATP, ADP and AMP were 2275 ± 153 (mean ± SEM,n= 4), 941 ± 96 (mean ± SEM,n= 5) and 175 ± 5 (mean ± SEM,n= 5) nmol Pi liberated per min per mg of protein, respectively. TheKmvalues for ATP, ADP and AMP were 224 ± 8 μM (mean ± SEM,n= 4), 163 ± 15 μM (mean ± SEM,n= 5) and 117 ± 5 μM (mean ± SEM,n= 5), respectively. The competition plot showed that ATP and ADP were hydrolyzed at the same active site on the enzyme. It may be postulated that the physiological role for this ecto‐enzyme cascade is to terminate the action of the co‐transmitter ATP, generating adenosine.
Induction of transforming growth factor‐beta 1 on dentine pulp cells in different culture patterns
Authors: Nie Xin , Tian Weidong , Zhang Yongjie , Chen Xizhe , Dong Rui , Jiang Ming , Chen Famin , Jin Yan 
Published: February 2006

AbstractRecent studies have documented that TGF‐β1 takes part in dental pulp tissue repair. Moreover, dental pulp cells have the potential to differentiate into odontoblast‐like cells and produce reparative dentine in this process. However, the molecular mechanisms and potential interactions between TGF‐β1 and dental pulp cells are not clear due to the complexity of the pulp/dentine microenvironment. In this study, we investigated the induction of TGF‐β1 on the dental pulp cells in cell culture, tissue culture and three‐dimensional culture patterns. These results demonstrated that TGF‐β1 significantly increased the proliferation of cells and activity of ALPase. Dental pulp cells cultured in the presence of TGF‐β1 formed mineralization nodules. In the organ culture, dental pulp cells treated with TGF‐β1 differentiated into odontoblast‐like cells and formed a pulp‐dentinal complex; and TGF‐β1 significantly induced synthesis of dentine relative proteins DSPP, DMP‐1. The dental pulp cells share some characteristics of the odontoblast, such as a parallel arrangement with columnar form and a unilateral cell process. Together, these data indicate that TGF‐β1 can make dental pulp cells differentiated into odontoblast‐like cells and form the pulp‐dentinal complex. Moreover, these results suggest that TGF‐β1 is an important regulatory factor in odontoblast differentiation during tooth development and pulp repair.
Plasma concentrations of the novel peptide apelin are decreased in patients with chronic heart failure
Authors: Chong Kwok Shiong , Gardner Roy S. , Morton James J. , Ashley Euan A. , McDonagh Theresa A. 
Published: February 2006

AbstractBackground:Apelin, the novel endogenous ligand for the G‐protein‐coupled receptor APJ, has shown positive inotropic, vasodilatory and diuretic properties in animal studies. Differential expression and synthesis of apelin and APJ receptors have been observed in normal and failing human hearts, suggesting a possible role in cardiovascular homeostasis. Changes in plasma apelin concentrations in relation to heart failure have been described in small studies with conflicting results. Our aim was to evaluate plasma apelin concentrations in a large cohort of patients with chronic heart failure (CHF) across a broad spectrum of disease severity.Method and results:Plasma apelin concentrations were measured in 202 patients with CHF secondary to left ventricular systolic dysfunction and 22 age‐matched controls. Plasma apelin concentrations were significantly lower in patients with CHF, irrespective of NYHA class, ejection fraction or aetiology when compared to age‐matched controls (0.85 [0.53–2.04] versus 3.76 [0.85–5.13] ng/ml, p<0.001). Apelin concentrations were correlated with peak VO2 and right ventricular ejection fraction, but not with age, sex, body mass index, renal function or NT‐proBNP concentrations.Conclusions:Plasma apelin concentrations are decreased in patients with CHF. The Apelin‐APJ signaling pathway may be a potentially important mediator in the pathophysiological processes of heart failure and may therefore have potential therapeutic implications.