bluuebunny/crossref_metadata_2025_split huggingface dataset:
Litter-Raking Forests in Se Slovenia and In Croatia
Authors: Šilc Urban , Čarni Andraž , Košir Petra , Marinšek Aleksander , Zelnik Igor 
Published: August 2008

Litter-Raking Forests in Se Slovenia and In CroatiaThe standard Braun-Blanquet method was used for sampling litter-raking vegetation in southeastern Slovenia (Suha krajina, Bela krajina, Kočevsko) and in the border region in Croatia. Relevés were classified with the TWINSPAN program and two associations were separated:Pteridio-BetuletumTrinajstić et Šugar ex Rauš et Matić 1994 andMolinio-QuercetumŠugar 1972. Both communities are the result of intensive litter collecting (and other human impacts). The first one thrives on carbonate bedrock, while the second is limited on silicate bedrock, as is reflected in its specific floristic composition. Due to abandonment of litter collecting these stands are in progressive successional development, and typical variants are becoming rare and endangered.
Phytosociological Characteristic of the Plant Communities With the Occurrence of Endemic Species Cyclamen Fatrense
Authors: Kanka Róbert , Turis Peter , Chilová Viktória 
Published: August 2008

Phytosociological Characteristic of the Plant Communities With the Occurrence of Endemic SpeciesCyclamen FatrenseIn this contribution we bring together the basic phytosociological characteristics of communities with the presence of speciesCyclamen fatrensein the herb layer. The analysis was made on the basis of 30 original phytosociological relevés. The main criterion for the relevés recording was the selection of the broadest possible range of biotopes with presence and the highest possible abundance of speciesCyclamen fatrenseon the entire area of its occurrence, which is represented by the Vel'ká Fatra and Starohorské vrchy Mts. The forest phytocoenoses of the associationCarici albae-FagetumMoor 1952, and phytocoenoses of clearings of the associationEpilobio-Atropetum bella-donnaeR. Tx. 1931 em. 1950, were classified by using Zürich-Montpellier School method. Additionally, 18 relevés with the presence of speciesCyclamen fatrensewere excerpted from already published works and detailed comparison was also made.
Characteristics of US workers whose blood lead levels trigger the medical removal protection provision, and conformity with biological monitoring requirements, 2003–2005
Authors: Tak SangWoo , Roscoe Robert J. , Alarcon Walter , Ju Jun , Sestito John P. , Sussell Aaron L. , Calvert Geoffrey M. 
Published: August 2008

AbstractBackgroundWorkers with blood lead levels (BLL) ≥60 µg/dl (50 µg/dl for construction workers) or with three or more consecutive BLLs over at least 6 months that average 50 µg/dl or greater are required to be removed from work involving lead exposure that exceeds the OSHA action level. This study estimates the proportion of workers with BLLs that trigger the medical removal provision by industry sector, and examines whether workers received appropriate follow‐up blood lead testing.MethodsThree years (2003–2005) of data from the Adult Blood Lead Epidemiology and Surveillance program were analyzed to identify those industries with a high percentage of workers with BLLs that trigger the medical removal provision. Adjusted rate ratios (RR) of adults with such BLLs were estimated by industry sector compared to the battery manufacturing industry using Poisson regression models.ResultsOut of 13,724 adults with BLLs ≥25 µg/dl, a total of 533 adults had BLLs that triggered the medical removal provision. RRs of adults with BLLs triggering medical removal were highest for “painting and wall covering contractors” (RR = 22.1) followed by “highway, street and bridge construction” (RR = 14.7), “amusement, gambling, and recreation” (RR = 11.4), and “glass product manufacturing” (RR = 10.1). Overall, 29% of adults with BLLs triggering medical removal received appropriate follow‐up blood lead tests and met the eligibility to return to lead work.ConclusionsThese findings suggest that additional efforts are needed to prevent occupational overexposure to lead in adults, and to ensure proper medical management of those workers who meet medical removal criteria. Am. J. Ind. Med. 51:691–700, 2008. Published 2008 Wiley‐Liss, Inc.
Kinetics and mechanism of Cr(VI) adsorption onto tea‐leaves waste
Authors: Mozumder Md. Salatul Islam , Khan Md. Maksudur Rahman , Islam Md. Akhtarul 
Published: August 2008

AbstractAdsorption equilibrium and kinetic experiments have been conducted in batch mode to evaluate Cr(VI)‐tea‐leaves waste system. The equilibrium data followed the Langmuir adsorption isotherm and the adsorption was viewed as a physicochemical reversible process. A unified approach model was used to describe the adsorption system from both equilibrium and kinetic viewpoints. The model satisfactorily described both kinetic and equilibrium data. The adsorption and desorption rate constants were evaluated from the model fittings and were not dependent on initial concentration and adsorbent doses. pHzpc of the adsorbent was evaluated as 4.2 ± 0.1, and below that pH the adsorbent surface is positively charged. Adsorption of Cr(VI) was found highly pH‐dependent, and the removal efficiency dropped sharply from 95 to 10% when pH of the system changed from 2 to 5. The surface functional groups of tea‐leaves waste (before and after adsorption) were analyzed by Fourier transform infrared (FTIR) and the amine groups were found to take part in the adsorption of Cr(VI). The experimental result inferred that electrostatic attraction between the surface and the species is one of the major adsorption mechanisms for binding metal ions to the tea‐leaves waste. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd.
Recent developments in the study of hypnotic pain reduction: a new golden era of research?
Authors: Milling Leonard S. 
Published: August 2008

AbstractThis article presents a selective review of recent developments in research on hypnotic pain reduction. A profusion of well‐controlled studies of hypnotic analgesia in children suggests that hypnosis ranks among the more effective psychological tools for managing the distress experienced by youngsters undergoing invasive medical procedures. This literature also draws attention to the importance of matching interventions to natural pain coping strategies. Virtual reality hypnosis shows much promise as a treatment and may offer hope to people who might otherwise be unable to experience hypnotic analgesia. Response expectancies appear to be a key psychological mechanism of hypnotic pain reduction. Neuroimaging studies point to activity in the midcingulate cortex as a possible biological mechanism of hypnotic analgesia. More generally, based upon the findings of a sound empirical literature, important meta‐analytic and qualitative reviews have concluded that hypnosis is effective for reducing both experimental and clinical pain. Indeed, the study of hypnotic pain reduction is vigorous, innovative, and may well have entered a golden era of research. Copyright © 2008 British Society of Experimental & Clinical Hypnosis. Published by John Wiley & Sons, Ltd.
Biomedical Potentials of Crown Ethers: Prospective Antitumor Agents
Authors: Kralj Marijeta , Tušek‐Božić Ljerka , Frkanec Leo 
Published: August 2008

AbstractCrown ethers are of enormous interest and importance in chemistry, biochemistry, materials science, catalysis, separation, transport and encapsulated processes, as well as in the design and synthesis of various synthetic systems with specific properties, diverse capabilities, and programmable functions. Classical crown ethers are macrocyclic polyethers that contain 3–20 oxygen atoms separated from each other by two or more carbon atoms. They are exceptionally versatile in selectively binding a range of metal ions and a variety of organic neutral and ionic species. Crown ethers are currently being studied and used in a variety of applications beyond their traditional place in chemistry. This review presents additional applications and the ever‐increasing biomedical potentials of these intriguing compounds, with particular emphasis on the prospects of their relevance as anticancer agents. We believe that further research in this direction should be encouraged, as crown compounds could either induce toxicities that are different from those of conventional antitumor drugs, or complement drugs in current use, thereby providing a valuable adjunct to therapy.
The prognostic significance of cytokine levels in newly diagnosed acute myeloid leukemia and high‐risk myelodysplastic syndromes
Authors: Tsimberidou Apostolia Maria , Estey Elihu , Wen Sijin , Pierce Sherry , Kantarjian Hagop , Albitar Maher , Kurzrock Razelle 
Published: August 2008

AbstractBACKGROUND.Tumor necrosis factor (TNF)‐α and other cytokines are involved in the pathogenesis of acute myeloid leukemia (AML) and high‐risk myelodysplastic syndromes (MDS), but their prognostic significance in these diseases is unknown. In the current study, the authors assessed the association between serum levels of various cytokines and clinical outcomes in patients with untreated AML or high‐risk MDS.METHODS.Serum levels of TNF‐α, interleukin (IL)‐1 receptor antagonist, IL‐6, IL‐10, and endostatin were measured in patients with AML or high‐risk MDS who presented for treatment at The University of Texas M. D. Anderson Cancer Center from September 1994 through January 2001. Univariate and multivariate analyses were performed to test for correlations with clinical outcomes.RESULTS.Higher TNF‐α levels were found to correlate with poorer performance status; higher leukocyte counts; higher levels of β2‐microglobulin, creatinine, uric acid, and alkaline phosphatase; lower levels of creatinine clearance and albumin; baseline infection; and M4‐M5 AML subtypes. TNF‐α levels <10 pg/mL were associated with higher rates of complete remission (P = .003), survival (P = .0003), and event‐free survival (EFS) (P = .0009). However, on multivariate analyses, TNF‐α level ≥10 pg/mL was not found to be an independent factor predicting clinical outcomes, but became statistically significant when leukocyte count was excluded from the models. The other cytokines were not found to be predictive of clinical outcomes.CONCLUSIONS.High serum TNF‐α level is an adverse prognostic factor for survival and EFS in patients with untreated AML or high‐risk MDS. Cancer 2008. © 2008 American Cancer Society.
Cyclic Voltammetric Behavior of Nitrogen‐Doped Tetrahedral Amorphous Carbon Films Deposited by Filtered Cathodic Vacuum Arc
Authors: Khun N. W. , Liu E. , Guo H. W. 
Published: August 2008

AbstractNitrogen‐doped tetrahedral amorphous carbon (ta‐C : N) films were deposited by filtered cathodic vacuum arc (FCVA) technique using nitrogen as a background gas. The structure of the ta‐C : N films was studied with X‐ray photoelectron spectroscopy (XPS) and Raman spectroscopy in terms of nitrogen flow rate used during the film deposition. Potential windows of the films measured in deaerated and unstirred solutions, such as 0.5 M HCl, 0.1 M KCl, 0.1 M NaCl, 0.1 M KOH, and 0.1 M NaOH, were about 2.4, 2.32, 3.2, 3.1, and 3.25 V, respectively. This study showed that the potential windows of the ta‐C : N films were also affected by nitrogen flow rate. The ta‐C : N films used in this study had the desired voltammetric characteristics suitable for electrochemical analysis.
Cu(II) Hexacyanoferrate(III) Modified Carbon Paste Electrode; Application for Electrocatalytic Detection of Nitrite
Authors: Ojani Reza , Raoof Jahan‐Bakhsh , Norouzi Banafsheh 
Published: August 2008

AbstractCopper hexacyanoferrate (CuHCF) film‐modified carbon paste electrode (CPE) has been prepared from various electrolytic aqueous solutions using consecutive cyclic voltammetry. The cyclic voltammograms showed the direct deposition of CuHCF films from the mixing of Cu2+ and Fe(CN)63− ions and each time with one of the six cations: H+, Na+, K+, NH4+, Mg2+, and Al3+. The CuHCF film showed a single redox couple that exhibited a cation effect (Na+, K+, Mg2+, and NH4+) and anion effect (Cl−, NO3−, SO42−, ClO4−, and BrO3−) in the cyclic voltammograms. Voltammetric studies have indicated that in presence of nitrite, the cathodic peak current of CuHCF increases, followed by a decrease in the corresponding anodic current. This indicated that nitrite was reduced by the redox mediator immobilized on the electrode surface via an electrocatalytic mechanism. The process of reduction and its kinetics were investigated by using cyclic voltammetry, differential pulse voltammetry, chronoamperometry and chronocoulometry techniques. The electrocatalytic ability about 800 mV can be seen. The rate constant of the catalytic reduction of nitrite was found to be 7.9×105 cm3 mol−1 s−1. Linearity range obtained was 5×10−5−8.4×10−3 by cyclic voltammetry and 8×10−6−1.3×10−3 and 4×10−3−2×10−2 by differential pulse voltammetry.
Hydrothermal Synthesis of Titanium‐Supported Nickel Nanoflakes for Electrochemical Oxidation of Glucose
Authors: Yi Qingfeng , Huang Wu , Yu Wenqiang , Li Lei , Liu Xiaoping 
Published: August 2008

AbstractTitanium‐supported nanoscale flaky nickel electrode (nanoNi/Ti) was prepared by a hydrothermal process using hydrazine hydrate as a reduction agent. Its electrocatalytic activity as an electrocatalyst for the electrooxidation of glucose was evaluated in alkaline solutions using cyclic voltammetry (CV), chronoamperometric responses (CA) and electrochemical impedance spectra (EIS). The nanoNi/Ti electrode exhibits significantly high current density of glucose oxidation. A high catalytic rate constant of 1.67×106 cm3 mol−1 s−1 was calculated from amperometric responses on the nanoNi/Ti electrode. Low charge transfer resistances on the nanoNi/Ti in 0.5 M NaOH containing various concentrations of glucose were obtained according to the analysis for EIS. Furthermore, amperometric data show a linear dependence of the current density for glucose oxidation upon glucose concentration in the range of 0.05–0.6 mM with a sensitivity of 7.32 mA cm−2 mM−1. A detection limit of 0.0012 mM (1.2 μM) M glucose was found. Results show that the prepared nanoNi/Ti electrode presents high electrocatalytic activity for glucose oxidation.
Stimulation of human mesenchymal stem cells and osteoblasts activities in vitro on silicon‐releasable scaffolds
Authors: Obata Akiko , Kasuga Toshihiro 
Published: August 2008

AbstractCellular activities of human osteoblasts (HOBs) and mesenchymal stem cells (MSCs) on a silicon‐releasable scaffold, siloxane‐doped poly(lactic acid) and vaterite composite coated with hydroxycarbonate apatite (SPV‐H), were estimated using a medium with or without organic factors, such as dexamethasone (Dex) and β‐glycerophosphate (β‐GP), for inducing mineralization or differentiation. As a control, a composite film containing no silicon (denoted by PV‐H) was prepared using poly(lactic acid) and vaterite. HOBs cultured on SPV‐H formed some agglomerates, bone nodules, after a 21‐day culture in a medium without the organic factors, whereas no agglomerate was observed on PV‐H. Laser Raman spectra implied that calcium phosphate precipitated in HOBs on the SPV‐H. The silicon species in SPV‐H stimulated HOBs to mineralization. The culture tests using MSCs show that the level of alkaline phosphatase (ALP) activity in the cells cultured on SPV‐H increased during the 21‐day culture in a medium without Dex and β‐GP. The level was unchanged in MSCs cultured on PV‐H. In the case of supplementing Dex and β‐GP to the medium, the level of ALP activity in MSCs cultured on SPV‐H was higher than that on PV‐H at all time points during the 21‐day culture. The silicon species in SPV‐H were regarded to induce and enhance the osteogenic differentiation of MSCs. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Injectable acrylic bone cements for vertebroplasty based on a radiopaque hydroxyapatite. Bioactivity and biocompatibility
Authors: Hernández Lidia , Parra Juan , Vázquez Blanca , Bravo Antonio López , Collía Francisco , Goñi Isabel , Gurruchaga Marilo , San Román Julio 
Published: August 2008

AbstractRadiopaque bone cements have been formulated to provide injectable pastes with improved bioactivity to be applied in vertebroplasty and kyphoplasty techniques. The bioactive compound was strontium containing hydroxyapatite salt, which was introduced as obtained (SrHA) or after treatment with MMA monomer (SrHA‐t). The in vitro bioactivity of the cements was tested in cement films or in cement pastes introduced directly in a simulated body fluid (SBF) solution at 37°C to mimic the in vivo conditions. Precipitation of an apatite‐like layer was observed for the 20 wt %‐SrHA‐t containing cement in the first experiments, and in all formulations in the second ones. The deposited particles were characterized by FTIR spectroscopy and by EDAX analysis. Radiopacity of cements after immersion in SBF was confirmed. The biocompatibility exhibited by the SrHA containing cements was, in some cases, superior to that shown by a formulation with 10 wt % of BaSO4. The new formulations prepared with the treated filler exhibited the lowest cytotoxicity and enhanced cellular proliferation. The in vivo biocompatibility tested by an intramuscular model in rats indicated the formation of a membrane formed by collagen fibers containing fibroblasts with no inflammatory cells, such as macrophages, giant cells or lymphocytes in all formulations. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
On the direct calculation of the free energy of quantization for molecular systems in the condensed phase
Authors: Geerke Daan P. , Luber Sandra , Marti Koni H. , Van Gunsteren Wilfred F. 
Published: August 2008

AbstractUsing the path integral formalism or the Feynman‐Hibbs approach, various expressions for the free energy of quantization for a molecular system in the condensed phase can be derived. These lead to alternative methods to directly compute quantization free energies from molecular dynamics computer simulations, which were investigated with an eye to their practical use. For a test system of liquid neon, two methods are shown to be most efficient for a direct evaluation of the excess free energy of quantization. One of them makes use of path integral simulations in combination with a single‐step free energy perturbation approach and was previously reported in the literature. The other method employs a Feynman‐Hibbs effective Hamiltonian together with the thermodynamic integration formalism. However, both methods are found to give less accurate results for the excess free energy of quantization than the estimate obtained from explicit path integral calculations on the excess free energy of the neon liquid in the classical and quantum mechanical limit. Suggestions are made to make both methods more accurate. © 2008 Wiley Periodicals, Inc. J Comput Chem 2009
Efficient evaluation of sampling quality of molecular dynamics simulations by clustering of dihedral torsion angles and Sammon mapping
Authors: Frickenhaus Stephan , Kannan Srinivasaraghavan , Zacharias Martin 
Published: August 2008

AbstractA direct conformational clustering and mapping approach for peptide conformations based on backbone dihedral angles has been developed and applied to compare conformational sampling of Met‐enkephalin using two molecular dynamics (MD) methods. Efficient clustering in dihedrals has been achieved by evaluating all combinations resulting from independent clustering of each dihedral angle distribution, thus resolving all conformational substates. In contrast, Cartesian clustering was unable to accurately distinguish between all substates. Projection of clusters on dihedral principal component (PCA) subspaces did not result in efficient separation of highly populated clusters. However, representation in a nonlinear metric by Sammon mapping was able to separate well the 48 highest populated clusters in just two dimensions. In addition, this approach also allowed us to visualize the transition frequencies between clusters efficiently. Significantly, higher transition frequencies between more distinct conformational substates were found for a recently developed biasing‐potential replica exchange MD simulation method allowing faster sampling of possible substates compared to conventional MD simulations. Although the number of theoretically possible clusters grows exponentially with peptide length, in practice, the number of clusters is only limited by the sampling size (typically much smaller), and therefore the method is well suited also for large systems. The approach could be useful to rapidly and accurately evaluate conformational sampling during MD simulations, to compare different sampling strategies and eventually to detect kinetic bottlenecks in folding pathways. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009
Simvastatin attenuation of cerebral vasospasm after subarachnoid hemorrhage in rats via increased phosphorylation of Akt and endothelial nitric oxide synthase
Authors: Sugawara Takashi , Ayer Robert , Jadhav Vikram , Chen Wanqiu , Tsubokawa Tamiji , Zhang John H. 
Published: August 2008

AbstractThe mechanisms involved in simvastatin‐mediated attenuation of cerebral vasospasm after subarachnoid hemorrhage (SAH) are unclear. We investigated the role of the phosphatidylinositol 3‐kinase/Akt (PI3K/Akt) pathway and endothelial nitric oxide synthase (eNOS) in the cerebral vasculature in statin‐mediated attenuation of cerebral vasospasm using wortmannin, an irreversible pharmacological PI3K inhibitor, and a rat SAH endovascular perforation model. Simvastatin was administered intraperitoneally in two dosages (1 mg/kg and 20 mg/kg) at 0.5, 24, and 48 hr after SAH and histological parameters of ipsilateral intracranial carotid artery (ICA) were assessed at 24 and 72 hr. SAH significantly decreased ICA diameter and perimeter while increasing wall thickness at both 24 and 72 hr. High‐dosage simvastatin prevented the reduction of ICA diameter and perimeter following SAH, whereas both high and low dosages reduced wall thickness significantly at 24 and 72 hr. The effects of simvastatin were significantly reversed by wortmannin. High‐dosage simvastatin increased pAkt and peNOS (phosphorylated forms) levels without increasing Akt and eNOS expression compared with the SAH group and also improved neurological deficits at 24 and 72 hr. Simvastatin did not affect protein levels by itself compared with untreated sham group. The present study elucidates the critical role of the PI3K activation leading to phosphorylation of Akt and eNOS in simvastatin‐mediated attenuation of cerebral vasospasm after SAH. © 2008 Wiley‐Liss, Inc.