bluuebunny/crossref_metadata_2025_split huggingface dataset:
Beitrag zu den Struktur‐Wirkungsbeziehungen am Acronycin
Authors: Reisch Johannes , Aly Samir M. El‐Moghazy 
Published: October 2006

AbstractDie Synthese von 1b, einem Aza‐anologon des Acronycins (1a), wird beschrieben. Die Wasserlöslichkeit von 1b übertrifft die von 1a um das 15‐fache. Im Screening am Transplantationstumor Leukämie P 388 erwies sich 1b ‐ wie 1a und Noracronycin ‐ als wirkungslos. Auch die mit 1a verwandten Verbindungen 6‐Hydroxy‐3,3,12‐trimethyl‐3,12‐dihydrochromeno[5,6‐b][1,8]naphthyridin‐7‐on, 5‐Hydroxy‐2,2‐11‐trimethyl‐2,11‐dihydrochromeno[7,6‐b][1,8]naphthyridin‐6‐on sowie 6‐Hydroxy‐3,3‐dimethyl‐3H‐pyrano[2′,3′:7,8]chromeno[2,3‐b]pyridin‐7‐on sind inaktiv.
New Lanthanum (III) Complex – Synthesis, Characterization, and Cytotoxic Activity
Authors: Kostova Irena , Rastogi Vinod K. , Kiefer Wolfgang , Kostovski Aleksandar 
Published: October 2006

AbstractThe complex of lanthanum (III) was synthesized reacting the respective inorganic salt with 5‐aminoorotic acid in amounts equal to the metal : ligand molar ratio of 1 : 3. The complex was prepared by adding an aqueous solution of lanthanum (III) nitrate to an aqueous solution of the ligand, subsequently raising the pH of the mixture gradually to approx. 5.0 through addition of a dilute solution of sodium hydroxide. The structure of the final complex was determined by means of spectral data (IR, Raman, 1H‐NMR) and elemental analysis. Significant differences in the IR spectrum of the complex were observed as compared to the spectrum of the ligand. A comparative analysis of the Raman spectrum of the complex with that of the free 5‐aminoorotic acid allowed a straightforward assignment of the vibrations of the ligand groups involved in coordination. The ligand and the complex were tested for the cytotoxic activities on the chronic myeloid leukemia derived K‐562, overexpressing the BCR‐ABL fusion protein and the non‐Hodgkin lymphoma derived DOHH‐2, characterized by a re‐expression of the anti‐apoptotic protein bcl‐2 cell lines. The results obtained indicate that the tested compounds exerted a considerable cytotoxic activity upon the evaluated cell lines in a concentration‐dependent matter, which enabled the construction of dose‐response curves and the calculation of the corresponding IC50 values. The inorganic salt exerted a very weak cytotoxic effect on these cells, which is in contrast to the lanthanum (III) complex.
Influence of antibiotic cefotaxime on somatic embryogenesis and plant regeneration in indica rice
Authors: Grewal Deepinder , Gill Raman , Gosal Satbir Singh 
Published: October 2006

AbstractAn antibiotic, cefotaxime (Omnatax™) has been found to promote somatic embryogenesis and subsequent plant regeneration in vitro in indica‐type basmati rice cultures. Response was highly genotype specific. The number, mass and morphology of the calli formed on the scutellar tissues were dependent on the growth medium (with or without cefotaxime). The embryogenic nature of nodular calli was confirmed through histological analysis and their plant regeneration ability. The calli of variety Pusa basmati 1 grown on medium supplemented with cefotaxime (100 mg/L) exhibited up to 70.5% plant regeneration as compared to control (51.51%). Plants regenerated from emryogenic calli were phenotypically normal and identical to seed‐derived plants and exhibited normal fertility. A limited humidity and an optimal aeration of the culture tubes further enhanced the frequency of somatic embryogenesis and plant regeneration.
Carbon Nanotube/Poly(methyl methacrylate) (CNT/PMMA) Composite Electrode Fabricated by In Situ Polymerization for Microchip Capillary Electrophoresis
Authors: Yao Xiao , Wu Huixia , Wang Joseph , Qu Song , Chen Gang 
Published: October 2006

AbstractWe describe the development and application of a novel carbon nanotube/poly(methyl methacrylate) (CNT/PMMA) composite electrode as a sensitive amperometric detector of microchip capillary electrophoresis (CE). The composite electrode was fabricated by the in situ polymerization of a mixture of CNTs and prepolymerized methyl methacrylate in the microchannel of a piece of fused silica capillary under heat. The performance of this unique system was demonstrated by the separation and detection of phenolic pollutants and purines. The new CNT‐based CE detector offered significantly lower operating potentials, yielded substantially enhanced signal‐to‐noise characteristics, and exhibited resistance to surface fouling and, hence, enhanced stability. Long‐term stability and reproducibility with relative standard deviations of less than 5 % for the peak current (n=20) were also demonstrated. The simplicity and significant performance exhibited by the CNT/PMMA composite electrode indicate great promise for conventional CE, flowing‐injection analysis, and other microfluidic analysis systems.
Polyisocyanides Derived from Tripeptides of Alanine
Authors: Metselaar Gerald A. , Adams P. J. Hans M. , Nolte Roeland J. M. , Cornelissen Jeroen J. L. M. , Rowan Alan E. 
Published: October 2006

AbstractHelical polymers of isocyanotripeptides derived from alanine have been synthesized and their architectures studied in detail. The helical conformation of the polyisocyanotripeptides is stabilized by internal hydrogen‐bonding arrays between the tripeptide side chains. The possibility of extending the well‐defined hydrogen‐bonded array, from dipeptide to tripeptide side chains, depends strongly on the stereochemistry of the constituent alanine amino acids, as has been shown by circular dichroism and IR studies. In polymers containing a weaker hydrogen‐bonding array adjacent to the polymer backbone, due to steric interactions between the alanine methyl groups, a stronger second hydrogen‐bonding array was present between the peptide bonds furthest away from the main chain, which is probably a result of stretching/compression of the helical‐polymer conformation.
Proapoptotic effects of NARC 1 (= PCSK9), the gene encoding a novel serine proteinase
Authors: Bingham Brendan , Shen Ru , Kotnis Smita , Lo C. Frederick , Ozenberger Bradley A. , Ghosh Nivedita , Kennedy Jeffrey D. , Jacobsen J. Steven , Grenier Jill M. , DiStefano Peter S. , Chiang Lillian W. , Wood Andrew 
Published: October 2006

AbstractBackgroundNARC 1/PCSK9 encodes a novel serine proteinase known to play a role in cholesterol homeostasis. NARC 1 mRNA expression in cerebellar granule neurons (CGNs) was discovered to be induced following an apoptotic injury. Coregulation of known apoptotic mediators (caspase‐3 and death receptor 6) raises the possibility that NARC 1 might be involved in the propagation of apoptotic signaling in neurons.MethodsCGNs were transfected with EGFP‐fusion constructs of wild‐type and mutant NARC 1, and a laser scanning cytometry‐based method of scoring cell death in transfectants was applied. Use of the poly‐caspase inhibitor BAF allowed assessment of the caspase‐dependence of the NARC 1 proapoptotic effect.ResultsWild‐type NARC 1 was found to have substantial proapoptotic effects that were only partially reversible by BAF. Mutation of the active site serine or deletion of the catalytic domain resulted in a reduced level of cell death, consistent with loss of the BAF‐sensitive component of cell death. NH2‐terminal deletion constructs of NARC 1 had effects similar to wild‐type, both in the absence and presence of BAF, whereas expression of COOH‐terminal deletion mutants produced a rate of cell death similar to wild‐type in the absence of BAF treatment, but which lacked the capacity to be reduced by treatment with BAF.ConclusionThe mechanism by which NARC 1‐EGFP over‐expression induces cell death in cultured CGNs remains unclear. Mutation analysis established a positive correlation between the presence of the Narc 1 active site serine in the transiently expressed protein and induction of the BAF‐sensitive component of the cell death phenotype. A caspase‐independent component proved sufficiently complex to map discretely within the Narc 1 protein. © 2006 International Society for Analytical Cytology
Technologies and applications of Al‐free high‐power laser diodes
Authors: Ohgoh Tsuyoshi , Fukunaga Toshiaki , Hayakawa Toshiro 
Published: October 2006

AbstractWe report high‐power technologies in 0.8‐µm Al‐free InGaAsP/InGaP laser diodes. To realize the high‐power operation, the improvement of catastrophic optical mirror damage (COMD) power density level is required. In addition to the use of low surface recombination velocity of Al‐free materials, optimization of waveguide thickness in broad waveguide structure with tensile‐strained barriers and current blocking structure near facets has led to high COMD power density level. Highly stable operation of Al‐free laser diodes with these structures has been obtained over 2500 hours at 2 W from a stripe width of µm. Applications of high‐power laser diodes are also described. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 158(1): 53–59, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20286
Incoming longwave radiation to melting snow: observations, sensitivity and estimation in Northern environments
Authors: Sicart J. E. , Pomeroy J. W. , Essery R. L. H. , Bewley D. 
Published: October 2006

AbstractAt high latitudes, longwave radiation can provide similar, or higher, amounts of energy to snow than shortwave radiation due to the low solar elevation (cosine effect and increased scattering due to long atmospheric path lengths). This effect is magnified in mountains due to shading and longwave emissions from the complex topography. This study examines longwave irradiance at the snow surface in the Wolf Creek Research Basin, Yukon Territory, Canada (60° 36′N, 134° 57′W) during the springs of 2002 and 2004. Incoming longwave radiation was estimated from standard meteorological measurements by segregating radiation sources into clear sky, clouds and surrounding terrain. A sensitivity study was conducted to detect the atmospheric and topographic conditions under which emission from adjacent terrain significantly increases the longwave irradiance. The total incoming longwave radiation is more sensitive to sky view factor than to the temperature of the emitting terrain surfaces. Brutsaert's equation correctly simulates the clear‐sky irradiance for hourly time steps using temperature and humidity. Longwave emissions from clouds, which raised longwave radiation above that from clear skies by 16% on average, were best estimated using daily atmospheric shortwave transmissivity and hourly relative humidity. An independent test of the estimation procedure for a prairie site near Saskatoon, Saskatchewan, Canada, indicated that the calculations are robust in late winter and spring conditions. Copyright © 2006 John Wiley & Sons, Ltd.
The response of precipitation and surface hydrology to tropical macro‐climate forcing in Colombia
Authors: Marin Saul , Ramírez Jorge A. 
Published: October 2006

AbstractIn tropical South America, weather and climate are affected by the meridional oscillation of the inter‐tropical convergence zone, the Pacific and Atlantic oceans, the Amazon basin, and the Andes Mountains. The dominant mode of the inter‐annual climate variability in the tropical Pacific is the El Niño/Southern Oscillation (ENSO) phenomenon. Colombia is among the South American countries that experiences large climate anomalies because of ENSO. However, the hydrologic response in Colombia to a particular ENSO event is highly complex and non‐linear.To describe this complex, non‐linear hydro‐climatic response to large‐scale atmospheric forcing in Colombia, a one‐way coupled atmospheric‐land surface hydrologic modelling approach is implemented whose main components are Colorado State University's Regional Atmospheric Modelling System (RAMS) and the Swedish Hydrologiska Byråns Vattenbalansavdelning‐Hydrologic Modelling System (HBV‐HMS). RAMS is implemented in a two‐nested grid domain for seasonal simulations and a four‐nested grid domain for daily simulations. Seasonal simulations emphasize the annual cycle at regional scales, while daily simulations focus on describing the diurnal cycle for specific watersheds. The HBV‐HMS is implemented for a specific watershed and used to examine its response at daily time scales.Results of the seasonal simulations reproduce quite well the observed spatial and temporal patterns of the hydro‐climatic variables: simulated temperature, pressure, wind velocity, and precipitation distributions show good agreement with observations. Results also show that the 1992 warm phase of ENSO led to a generalized decrease of precipitation along the Andes ranges and that the low lands of Colombia received more precipitation than during the 1989 cold ENSO phase. Similarly, daily‐simulated fields show good agreement with observed values. However, the simulated diurnal cycle of precipitation exhibits a temporal phase lag of several hours and simulated precipitation tends to underestimate both the total amount of precipitation and the duration of precipitation events. Despite these discrepancies, the results of the modelling effort clearly demonstrate the ability of this approach to capture the non‐linear and complex interactions of large‐scale atmospheric forcing and local characteristics as indicated by the satisfactory simulation of stream flow responses for a set of small watersheds. Copyright © 2006 John Wiley & Sons, Ltd.
Chronic studies in rats exposed to liquid effluent from coal gasification process
Authors: Kostial K. , Blanuša M. , Rabar I. , Maljković T. , Kello D. , Landeka M. , Bunarević A. , Stara J. F. 
Published: October 2006

AbstractThe health effects of the E‐effluent (water for quenching ash) from a coal gasification plant were assayed in a chronic experiment (16 month exposure) and a three generation reproduction study. Animals exposed to 100% E‐effluent had an increased daily intake of various inorganic elements (Fe, Cu, K, I, Se, Cd, Hg, Pb, As, F and Cr). In spite of that, the exposed and control animals had the same mortality rate, haematological findings, urinary protein excretion, trace element concentrations in kidneys, liver and femur, bone composition and morphometry, and histological findings. The pre‐ and post‐natal development and growth was unchanged during three generations. It is concluded that the higher intake of various inorganics caused no change in the parameters measured.
Selective determination of elemental mercury in blood and urine exposed to mercury vapor in vitro
Authors: Satoh Hiroshi , Hursh John B. , Clarkson Thomas W. , Suzuki Tsuguyoshi 
Published: October 2006

AbstractA method is described to ensure quantitative measurement of dissolved mercury vapor (Hg°) in blood and urine. Room air passed through samples of blood and urine carries with it all the dissolved Hg° but leaves behind all the ionic mercury (Hg++). Oxidation of Hg° to Hg++ in blood samples is completely inhibited by addition of ethanol (0.5% v/v). To minimize error due to evaporation of Hg°, it is suggested that samples should be stored at 0 °C and Hg° should be determined within 60 min of collection of blood samples and within 10 min of urine samples.
Alcohol and sulphate intermediates in the metabolism of toluene and xylenes to mercapturic acids
Authors: van Doorn R. , Leijdekkers Ch.‐M. , Bos R. P. , Brouns R. M. E. , Henderson P. Th. 
Published: October 2006

AbstractThe involvement of sequential side‐chain oxidation, sulphation and glutathione conjugation in the formation of mercapturic acids from toluene and xylenes was investigated. It was found that not only aralkanes but also aralkyl alcohols were excreted as mercapturic acids in the rat. The extent of mercapturic acid excretion varied over a more than 20‐fold range. Inhibition of ADH caused an increase and inhibition of sulphotransferase a decrease in the urinary excretion of thio compounds after administration of toluene, benzyl alcohol, o‐xylene and o‐methylbenzyl alcohol to rats. The position of the methyl groups attached to the aromatic nucleus affects the metabolism of aromatic hydrocarbons considerably. Factors that are involved in the high yield of mercapturic acids after administration of o‐xylene as compared to m‐ and p‐xylene, include the relatively low apparent affinity of o‐methylbenzyl alcohol for cytosolic ADH, the relatively high apparent affinity of o‐methylbenzyl alcohol for cytosolic sulphotransferase, and the high electrophilic reactivity of the o‐methylbenzyl sulphate.
Number connection test and continuous reaction times in non‐encephalopathic patients: A comparative study
Authors: Christensen Steen Erik , Elsass Peter , Vilstrup Hendrik 
Published: October 2006

AbstractNumber Connection Test (NCT) and Continuous Reaction Times (CRT) were determined in 94 hospitalized patients with no previous or actual cerebral dysfunction. By NCT, 47 patients used more than 30 s which is the upper normal limit. Of these, 5 used more than 50 s. Two patients exhibited a CRT exceeding the upper normal limit of 240 ms. Thus, accepting the upper limits quoted, one‐half of the patients were falsely classified as encephalopathic by NCT, but only 2% by CRT. This indicates that the NCT is too unspecific to exclude encephalopathy and suggests that the CRT is a more valid measure in this respect.
In vitro metabolism of inorganic arsenic by the gastro‐intestinal microflora of the rat
Authors: Rowland I. R. , Davies M. J. 
Published: October 2006

AbstractThe contents of the rat small intestine or caecum reduced sodium [74As] arsenate to arsenite over a period of 2–3 days. In the presence of caecal, but not small intestine, contents, small amounts of methyl arsonic acid and dimethylarsinic acid were formed. Stomach contents reduced arsenic very slowly. The metabolism of arsenate was inhibited by autoclaving the gut contents or by adding antibiotics, thus indicating that bacteria were involved. In prereduced media containing thioglycollate or cysteine in the absence of intestinal bacteria, sodium arsenate was reduced to arsenite. The rate of reduction of arsenate by the gut flora was increased by the presence of hydrogen sulphide or bile acids.
Effect of pharmacologic interventions on aldehyde dehydrogenase in the rat testicles
Authors: Messiha F. S. 
Published: October 2006

AbstractThe in vitro and in vivo effects of selected pharmacologic agents on cytosolic aldehyde dehydrogenase in the adult rat testicles were studied. Naltrexone, a narcotic antagonist, significantly inhibited epididymal but not testicular aldehyde dehydrogenase in vitro. Greater in vitro inhibition of aldehyde dehydrogenase in the epididymal preparation was determined in the presence of diphenyhydramine, a histamine H1‐receptor antagonist and by amantadine hydrochloride, an antiviral/antiparkinsonian agent. The latter drug also inhibited testicular aldehyde dehydrogenase from corresponding controls. The in vitro inhibition was non‐competitive as evaluated by reciprocal plots of the velocity of the reaction as a function of substrate concentrations. Short‐term oral administration of a biologically active metabolite of flutamide, a nonsteroidal antiandrogen, significantly induced testicular aldehyde dehydrogenase without concomitant changes in epididymal aldehyde dehydrogenase from respective controls. Conversely, administration of ethinylestradiol, an estrogenic steroid, inhibited testicular but not epididymal aldehyde hydrogenase in the rat.
Bio‐mimetic composite matrix that promotes endothelial cell growth for modification of biomaterial surface
Authors: Prasad C. Krishna , Muraleedharan C. V. , Krishnan Lissy K. 
Published: October 2006

AbstractThe incidence of thrombogenesis and occlusion of cardiovascular implants is likely to be reduced by endothelial cell (EC) growth promotion on biomaterials used for device fabrication. However, proper signaling between the matrix proteins deposited on the device surface and the cells grown on it is a prime requirement for growth and function. It was demonstrated earlier that a composition of matrix proteins that include fibrin, fibronectin, gelatin, and growth factors maintain a steady proliferation potential and prolong the survival of endothelial cells in vitro. In this study, assessment of the same matrix to prevent EC from dedifferentiation during in vitro culture and to promote endothelialization of biomaterials used for fabrication of cardiovascular implants is carried out. Up/down regulation of m‐RNA expression for a prothrombotic molecule‐plasminogen activator inhibitor (PAI), and two antithrombotic molecules‐ nitric oxide synthetase (eNOS) and tissue plasminogen activator (t‐PA) are chosen as the indicators of cell dedifferentiation during cell culture and passaging. Immunostaining for vinculin and actin demonstrated that composite coating on biomaterials improves focal adhesion and cytoskeletal organization that increases the quality of EC grown on it. EC proliferation, measured by 3H‐thymidine uptake, on all bare materials was poor and high incidence of cell apoptosis was noticed within 72 h in culture, whereas once coated with composite all materials showed good proliferation and survival. The results suggest that the designed composition of biomimetic adhesive proteins and growth factors is suitable for EC growth, survival, and functional integrity, thus making it suitable for cardiovascular tissue engineering that requires in vitro EC culture. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Compressive properties and degradability of poly(ε‐caprolatone)/hydroxyapatite composites under accelerated hydrolytic degradation
Authors: Ang K.C. , Leong K.F. , Chua C.K. , Chandrasekaran M. 
Published: October 2006

AbstractHydroxyapatite (HA) was incorporated as filler into polycaprolactone (PCL) matrix to improve the bioactivity as well as the compressive properties of the polymer composites that can be typically used in tissue engineering scaffolds. The compressive properties of five PCL/HA composites of different compositions were investigated in conjunction with the study of their rate of degradation. As PCL has a slow degradation rate, the experiment was conducted in a concentrated 5M sodium hydroxide medium to accelerate the degradation process. The compressive strength and modulus of all PCL/HA compositions were observed to decrease as the degradation experiment progressed, with samples having high HA content degraded most significantly as compared with samples with lower HA content. Pure PCL samples, however, were found to retain their mechanical properties comparatively well in the same degradation experiments. Although the addition of HA as filler into the PCL matrix was shown to have improved mechanical properties and bioactivity initially, these results do raise concerns of material properties being compromise during hydrolytic degradation. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2007