bluuebunny/crossref_metadata_2025_split huggingface dataset:
Degradation of Macromolecular Organic Compounds in a Tropical Lagoon (Ciénaga Grande, Colombia) and its Ecological Significance
Authors: Hoppe Hans‐Georg , Gocke Klaus , Zamorano Doris , Zimmermann Reinhard 
Published: February 2007

AbstractPrimary production and decomposition of organic substances were investigated in a tropical lagoon during the rainy season. Production and mineralization were measured using the oxygen method. Total bacteria numbers and biomasses were estimated with epifluorescence microscopy, and the enzymatic degradation capacity of model substrates was determined photometrically. These parameters were measured in the water and sediment of the lagoon itself and also in its effluents and incoming waters. The aim of the study was to determine the sites of highest microbial activity in the lagoon and to compare its activity with other coastal water bodies. Since the shallow water lagoon contains a large amount of particulate matter, it was of special interest to study the degradation of this material and its influence on the microbial population. It was found that up to 14 % of the bacteria colonized the particles and that 62 % of the respiration originated in the particle fraction >8 μm. Highest exoenzymatic activities were measured in the sediment and water of the mangrove belt. It is concluded that decomposition and conditioning of particulate organic matter play dominant roles in the recycling of organic carbon in the lagoon.
A Study of the Chromatiaceae in a Saline Meromictic Lake in Saskatchewan, Canada
Authors: Parker R. D. , Hammer U. T. 
Published: February 2007

AbstractLamprocystis roseopersicina was found to be the dominant phototrophic bacterium in meromictic Deadmoose Lake. Using carbon‐14 it was determined that phototrophic bacteria fixed 14.3 g C m−2 year−1, 17.1 % of the total limnetic primary production. Experiments indicated low light intensities (X = 8.87 × 10−2 cal cm−2hr−1) to be the most important factor limiting bacterial production. Lamprocystis was shown to be capable of photoorganoheterotrophic uptake of glucose.
Chitosan‐phosphorylated chitosan polyelectrolyte complex hydrogel as an osteoblast carrier
Authors: Li Quan‐Li , Chen Zhi‐Qing , Darvell Brian W. , Liu Lai‐Kui , Jiang Hong‐Bing , Zen Quan , Peng Qian , Ou Guo‐Min 
Published: February 2007

AbstractTo simulate extra‐cellular matrix, a novel three‐dimensional scaffold of polyelectrolyte complex (PEC) hydrogel as an osteoblast carrier was synthesized. First, chitosan, a natural glycosaminoglycan, was modified by phosphorylation to obtain a water‐soluble phosphorylated chitosan (P‐content: 10.7 mass%). The PEC hydrogel was then formed from equal volumes of 0.173 mass% phosphorylated chitosan in water and 1 mass% chitosan in 1% (V/V) acetic acid solution. Rat osteoblasts were seeded in the hydrogel. The PEC hydrogel had a three‐dimensional hierarchically‐porous structure and good cytobiocompatibility for osteoblasts in vitro. It is concluded that the PEC hydrogel is a promising material as an osteoblast carrier. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2007
Factors related to contraction and mechanical strength of collagen gels seeded with canine endotenon cells
Authors: Chen Meng‐Yi , Sun Yulong , Zhao Chunfeng , Zobitz Mark E. , An Kai‐Nan , Moran Steven L. , Amadio Peter C. 
Published: February 2007

AbstractFibroblasts can construct a hydrated collagen lattice to a tissue‐like structure that is greatly influenced by initial culture conditions. The purpose of this study was to investigate the effects of cell concentration and collagen concentration on the contraction kinetics and mechanical properties of resultant endotenon‐derived fibroblast‐seeded collagen lattice. The experiment was designed to evaluate the effect of cell concentration (0, 0.25, 0.5, and 1.0 ××××× 106 cells/mL) and collagen concentration (0.5, 1.0, 1.5, and 2.0 mg/mL). Collagen lattice contraction was recorded for 42 days, after which time the lattices were mechanically tested. The collagen lattices seeded with higher initial cell concentration had a shorter contraction lag phase (p < 0.01), and exhibited a higher ultimate stress (p < 0.01) and instantaneous and equilibrium modulus (p < 0.01) than those seeded with a lower initial cell concentration. The collagen lattices cultured with a lower initial collagen concentration also had a shorter contraction lag phase, and exhibited greater instantaneous and equilibrium modulus (p < 0.01) than those cultured with higher initial collagen concentration. The collagen lattices of initial 0.5 mg/mL collagen concentration had the highest value of ultimate stress (p < 0.03). © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2007
Implementation of π‐π interactions in molecular dynamics simulation
Authors: Yuki Hitomi , Tanaka Yoshikazu , Hata Masayuki , Ishikawa Hidenori , Neya Saburo , Hoshino Tyuji 
Published: February 2007

AbstractNo explicit π‐π interaction term has been incorporated in the conventional molecular dynamics (MD) simulation programs in spite of its significant role in the folding of biomolecules and the clustering of organic chemicals. In this article, we propose a technique to emphasize the effect of π‐π interactions using a function of energy and implement it into an MD simulation program. Several trial calculations show that the π‐π incorporated program gives improved results consistent with experimental data on atom geometry and has no unfavorable interference with the conventional computational framework. This indicates an importance of the explicit consideration of π‐π interactions in MD simulation. © 2007 Wiley Periodicals, Inc.J Comput Chem 2007
Performance of mentally retarded forensic patients on the test of memory malingering
Authors: Simon Michael J. 
Published: February 2007

AbstractThe utility of the Test of Memory Malingering (TOMM) with mentally retarded forensic patients was assessed. Twenty‐one adjudicated forensic inpatients, who had been diagnosed with mental retardation, were administered the TOMM. The majority of these patients also suffered from an Axis I mental disorder. The participants attained a mean score of 48.7 on Trial 2, with only 1 participant scoring below the standard cutoff for malingering (i.e., 45). The participants attained a mean score of 49.4 on the Retention Trial, with no participants falling below the cutoff for malingering. The results clearly indicate that mildly retarded forensic patients can perform well on the TOMM. The findings provide evidence that the TOMM can be used in the assessment of mildly retarded criminal defendants with little fear of obtaining false indications of malingering. © 2007 Wiley Periodicals, Inc. J Clin Psychol 63: 339–344, 2007.
Differential health effects of written processing of the experience of a surgical operation in high‐ and low‐risk conditions
Authors: Solano Luigi , Pepe Luisa , Donati Valentina , Persichetti Stefano , Laudani Guido , Colaci Andrea 
Published: February 2007

AbstractThe aim of this study was to assess the effects of the writing technique on postoperative course in interaction with different levels of risk. Participants were 40 urologic inpatients waiting to undergo transurethral resection of the prostate, with different levels of surgical risk as assessed with the Goldman Preoperative Risk Index (L. Goldman et al., 1978). Only 20 participants wrote for 3 days about the experience of being in the hospital. Measures were days of stay in the hospital after the operation, the Symptom Check List (SCL‐90; L. R. Derogatis, 1977; Italian version: G. Magni, C. Messina, D. De Leo, A. Mosconi, & M. Carli, 1983) scores, and a medical evaluation of postoperative course. A significant positive effect of writing on all three dependent variables emerged only in low‐risk participants. High‐risk writing participants showed a nonsignificantly worse postoperative course on all parameters than did high‐risk nonwriting participants. In highly stressful conditions, writing therefore should be employed only with caution. © 2007 Wiley Periodicals, Inc. J Clin Psychol 63: 357–369, 2007.
Powerful spin in the conclusion of wampold et al.'s re‐analysis of placebo versus no‐treatment trials despite similar results as in original review
Authors: Hróbjartsson Asbjørn , Gøtzsche Peter C. 
Published: February 2007

AbstractB. E. Wampold, T. Minami, S. C. Tierney, T. W. Baskin, and K. S. Bhati (2005) re‐analyzed trials included in our systematic review of randomized clinical trials that compared placebo with no treatment (A. Hróbjartsson & P. C. Gøtzsche, 2001). Based on 11 trials, B. E. Wampold et al. concluded that “ … the placebo effect is robust” (p. 850). We (2001) concluded, based on 130 trials, that “we found little evidence in general that placebos have powerful clinical effects” (p. 1599). In this commentary, we examine the reasons for this discrepancy. For trials with continuous outcomes, our analyses (82 trials) and that of B. E. Wampold et al. (5 trials) resulted in pooled standardized mean differences that were small and essentially identical: −0.28 (95% confidence interval = −0.38 to −0.19) versus −0.29 (95% confidence interval = −0.52 to −0.06). There was considerable risk of bias (e.g., reporting bias, sample‐size bias). Similarly, for trials with binary outcomes, our analysis (32 trials) and that of B. E. Wampold et al. (6 trials) found no statistically significant pooled effect of placebo interventions and were essentially identical: relative risk 0.95 (95% confidence interval = 0.88–1.02) versus odds ratio 0.99 (95% confidence interval = 0.81–1.23). Thus, B. E. Wampold et al.'s conclusion was not substantiated by their data, and is best characterized as powerful spin. © 2007 Wiley Periodicals, Inc. J Clin Psychol 63: 373–377, 2007.
Contingency table techniques for three dimensional atom probe tomography
Authors: Moody Michael P. , Stephenson Leigh T. , Liddicoat Peter V. , Ringer Simon P. 
Published: February 2007

AbstractA contingency table analysis procedure is developed and applied to three dimensional atom probe data sets for the investigation of fine‐scale solute co‐/anti‐segregation effects in multicomponent alloys. Potential sources of error and inaccuracy are identified and eliminated from the technique. The conventional P value testing techniques associated with χ2 are shown to be unsatisfactory and can become ambiguous in cases of large block numbers or high solute concentrations. The coefficient of contingency is demonstrated to be an acceptable and useful basis of comparison for contingency table analyses of differently‐conditioned materials. However, care must be taken in choice of block size and to maintain a consistent overall composition between experiments. The coefficient is dependent upon block size and solute composition, and cannot be used to compare analyses with significantly different solute compositions or to assess the extent of clustering without reference to that of the randomly ordered case. It is shown that as clustering evolves into larger precipitates and phases, contingency table analysis becomes inappropriate. Random labeling techniques are introduced to infer further meaning from the coefficient of contingency. We propose the comparison of experimental result, μexp, to the randomized value, μrand, as a new method by which to interpret the quantity of solute clustering present in a material. It is demonstrated that how this method may be utilized to identify an appropriate size of contingency table analysis blocks into which the data set is partitioned to optimize the significance of the results. Microsc. Res. Tech., 2007. © 2007 Wiley‐Liss, Inc.
Visualization of hemodynamics in intracranial arteries using time‐resolved three‐dimensional phase‐contrast MRI
Authors: Yamashita Shuhei , Isoda Haruo , Hirano Masaya , Takeda Hiroyasu , Inagawa Shoichi , Takehara Yasuo , Alley Marcus T. , Markl Michael , Pelc Norbert J. , Sakahara Harumi 
Published: February 2007

AbstractPurposeTo visualize the hemodynamics of the intracranial arteries using time‐resolved three‐dimensional phase‐contrast (PC)‐MRI (4D‐Flow).Materials and MethodsMR examinations were performed with a 1.5T MR unit on six healthy volunteers (22–50 years old, average = 30 years). 4D‐Flow was based on a radiofrequency (RF)‐spoiled gradient‐echo sequence, and velocity encoding (VENC) was performed along all three spatial directions. Measurements were retrospectively gated to the electrocardiogram (ECG), and cine series of three‐dimensional (3D) data sets were generated. The voxel size was 1 × 1 × 1 mm, and acquisition time was 30–40 minutes. 4D data sets were calculated into time‐resolved images of 3D streamlines, 3D particle traces, and 2D velocity vector fields by means of flow visualization software.ResultsWe were able to see the 3D streamlines from the circle of Willis to the bilateral M2 segment of the middle cerebral arteries (MCAs). Time‐resolved images of 3D particle traces also clearly demonstrated intracranial arterial flow dynamics. 2D velocity vector fields on the planes traversing the carotid siphon or the basilar tip were clearly visualized. These results were obtained in all six volunteers.Conclusion4D‐Flow helped to elucidate the in vivo 3D hemodynamics of human intracranial arteries. This method may be a useful noninvasive means of analyzing the hemodynamics of intracranial arteries in vivo. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Age dependence of cerebral perfusion assessed by magnetic resonance continuous arterial spin labeling
Authors: Biagi Laura , Abbruzzese Arturo , Bianchi Maria Cristina , Alsop David C. , Del Guerra Alberto , Tosetti Michela 
Published: February 2007

AbstractPurposeTo study the normal dependence of cerebral perfusion changes on age, to measure values of perfusion early in life, and to create a reference dataset.Materials and MethodsPerfusion maps were collected from a total of 44 healthy subjects (from four to 78 years old) using the arterial spin labeling (ASL) technique. The population was retrospectively divided into three age groups: children, teenagers, and adults. For each group, mean values of cerebral blood flow (CBF) were calculated in gray matter (GM) and white matter (WM). Results were compared across the three different age groups.ResultsCBF values decreased with age (97 ± 5 mL/100 g/minute in GM and 26 ± 1 mL/100 g/minute in WM for the children, GM 79 ± 3 mL/100 g/minute and WM 22 ± 1 mL/100 g/minute for the teenagers, and GM 58 ± 4 mL/100 g/minute, WM 20 ± 1 mL/100 g/minute for the adults). The quantitative results suggest a rapid drop, rather than a gradual decrease, in cerebral perfusion between children and adult subjects, especially in the GM. This step in CBF occurs during adolescence, at approximately the 16th year of age.ConclusionASL is a practical and quantitative technique suitable for perfusion measurement in children as well as adults. Perfusion measurements with ASL appear sensitive to neurophysiological changes occurring during brain maturation. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.
Perinatal kynurenine 3‐hydroxylase inhibition in rodents: Pathophysiological implications
Authors: Ceresoli‐Borroni Gianpiera , Guidetti Paolo , Amori Laura , Pellicciari Roberto , Schwarcz Robert 
Published: February 2007

AbstractThe kynurenine pathway (KP) of tryptophan degradation contains three neuroactive metabolites: the neuroinhibitory agent kynurenic acid (KYNA) and, in a competing branch, the free radical generator 3‐hydroxykynurenine (3‐HK) and the excitotoxin quinolinic acid (QUIN). These three “kynurenines” derive from a common precursor, L‐kynurenine, and are recognized for their role in brain physiology and pathophysiology. Inhibition of kynurenine 3‐hydroxylase, the enzyme responsible for 3‐HK formation, shifts KP metabolism in the mature brain toward enhanced KYNA formation. We now tested the cerebral effects of kynurenine 3‐hydroxylase inhibition in immature rodents. Rat pups treated with the kynurenine 3‐hydroxylase inhibitor UPF 648 (30 mg/kg, i.p.) 10 min after birth showed substantial increases in cerebral and liver kynurenine and KYNA levels up to 24 hr later, whereas 3‐HK and QUIN levels were simultaneously decreased. Administered to pregnant rats or mice on the last day of gestation, UPF 648 (50 mg/kg, i.p.) produced qualitatively similar changes (i.e., large increases in kynurenine and KYNA and reductions in 3‐HK and QUIN) in the brain and liver of the offspring. Rat pups delivered by UPF 648‐treated mothers and immediately exposed to neonatal asphyxia showed further enhanced brain KYNA levels. These studies demonstrate that acute kynurenine 3‐hydroxylase inhibition effectively shifts cerebral KP metabolism in neonatal rodents toward increased KYNA formation. Selective inhibitors of this enzyme may therefore provide neuroprotection in newborns and will also be useful for the experimental evaluation of the long‐term effects of perinatal KP impairment. © 2007 Wiley‐Liss, Inc.
Regulatory properties of 3‐deoxy‐D‐arabino‐heptulosonate‐7‐phosphate synthase isozymes from Candida maltosa
Authors: Bode R. , Melo C. , Birnbaum D. 
Published: February 2007

AbstractThe first step in the biosynthesis of aromatic amino acids by Candida maltosa was catalysed by two isozymes of 3‐deoxy‐d‐arabino‐heptulosonate 7‐phosphate (DAHP) synthase. The formation of which was constitutive. The phenylalanine‐sensitive and the tyrosine‐sensitive DAHP synthases were partially purified by hydroxylapatite chromatography and several properties of the separated isozymes were studied. Both enzymes showed a molecular weight of 90,000. The Km‐values of the tyrosine‐sensitive DAHP synthase were 0.20 mm for erythrose‐4‐phosphate (E‐4‐P) and 0.50 mm for phosphoenolpyruvate (PEP). Inhibition of this isozyme reaction by l‐tyrosine was competitive with respect to E‐4‐P (Ki = 0.028 mm) and non‐competitive with respect to PEP. The Km‐values of the phenylalanine‐sensitive DAHP synthase were estimated to be 0.65 mm for E‐4‐P and 0.63 mm for PEP; a Ki of 0.097 mm was obtained for l‐phenylalanine. A number of tyrosine and phenylalanine analogues and biosynthetic intermediates also inhibited the two isozyme reactions. For example, we observed a strong inhibitory effect of p‐hydroxyphenylpyruvate on the tyrosine‐sensitive DAHP synthase and of phenylpyruvate on the phenylalanine‐sensitive isozyme. Prephenate and arogenate had a less pronounced effect on the phenylalanine‐sensitive DAHP synthase.
Auswirkungen von Mutanteninduktion und Protoplastenfusion auf den DNA‐ und Proteingehalt vonPichia guilliermondii
Authors: Büttner Martina , Klinner U. , Birnbaum D. , Böttcher F. 
Published: February 2007

AbstractThe DNA content per cell of two tested auxotrophic mutants ofPichia guilliermondiiwas diminished in comparison to their wild‐type strains. After protoplast fusion between these mutants the majority of hybrids did not show the expected amount of DNA. In some hybrids it was only slightly higher than in the wild‐type strains, although heterozygosity for markers of three chromosomes could be established.The protein content per cell of most strains was positively correlated with the DNA content, but generally more affected as the DNA content by the induction of mutations and protoplast fusion. The protein/DNA ratio of the two mutants was strongly reduced, while this ratio was somewhat enhanced in one of the hybrids in comparison to the wild‐type strains and the majority of hybrids. Apparently, the reduced protein content per cell in the mutants seemed to be partially compensated in the hybrids.
Einfluß von Phosphat und Inhibitoren der Proteinsynthese auf das Wachstum und die Tentoxinbildung von Alternaria alternata (Fr.) Keissler
Authors: Edel B. , Brückner B. , Hänel I. , Tröger R. 
Published: February 2007

AbstractThe synthesis of a phytotoxic substance, tentoxin, by Alternaria alternata (Fr.) Keissler is negatively controlled by inorganic phosphate. We show here that the influence of phosphate on the production of this secondary metabolite is time‐dependent. By using inhibitors of protein synthesis (p‐fluorphenylalanine, cycloheximide) together with a resuspension technique, attempts were made to find out when the enzymes responsible for tentoxin synthesis are formed.
Influence of nourseothricin on growth and secondary metabolism of Streptomyces noursei JA 3890b
Authors: Röder B. , Plonka G. , Bormann E. J. , Gräfe U. 
Published: February 2007

AbstractThe nourseothricin‐producing S. noursei strain JA 3890 b possessed a high degree of resistance to its own antibiotic when grown in submerged cultures started from mycelium samples as inocula. In contrast, both the outgrowth of spores and the development of surface colonies from mycelium samples were severely inhibited in the presence of relatively low concentrations of nourseothricin, suggesting that the producer organism is susceptible to the autotoxic metabolite in particular stages of its development. Nourseothricin production by submerged cultures has been found to be independent of negative feedback regulation by the antibiotic.
Conditions for the exopolysaccharide synthesis from n‐hexadecane by an oil‐positive bacterium 437
Authors: Wang X. Y. , Schwartz W. 
Published: February 2007

AbstractSuitable conditions for exopolysaccharide synthesis from n‐hexadecane by the oil‐positive bacterium were: NaNO3 1.25–1.50 g, Na2HPO4 · 2 H2O 0.5 g, K2HPO4 0.5 g, MgSO4 · 7 H2O 0.5 g, H3PO4 (85%) 0–0.5 g, CaCl2 · 2 H2O 0.05 g, FeCl3 · 6 H2O 0.02 g, aqua dest. 1 l, pH 7.0–7.5, n‐hexadecane 2.5–3.0% (w/v). Under these conditions the viscosity of the broth from culture shaken at 30°C for 10 days was as high as 5,000–6,000 cSt (45°C). After pelleting of the cells, 11–13 g/1 polysaccharide were obtained by ethanol precipitation.
The temperature profiles of growth, thermal death and ethanol tolerance of the cellobiose‐fermenting yeast Candida wickerhamii
Authors: Cabeça‐Silva Cecilia , Madeira‐Lopes A. , Van Uden N. 
Published: February 2007

AbstractThe temperature profiles of growth and thermal death of the cellobiose‐fermenting yeast Candida wickerhamii was associative with the initial maximum, final maximum, optimum and minimum temperatures for growth around 38°C, 31°C, 31°C and 3°C, respectively. Ethanol enhanced thermal death by increasing the entropy of activation (entropy coefficient 7.2 entropy units mol−1 l−1), shifted the supraoptimal part of the profile to lower temperatures without disrupting it and increased the minimum temperature for growth. The temperature profile of ethanol tolerance with respect to growth displayed a narrow temperature plateau (18–22°C) of maximum tolerance (limit 7.4%, v/v, ethanol) while the toxic effects of ethanol increased steeply on either side of the plateau.
Hybridization of yeasts by protoplast fusion: Attempts to polyploidize Pichia guilliermondii
Authors: Klinner U. , Böttcher F. 
Published: February 2007

AbstractThe DNA content of fusion hybrids of Pichia guilliermondii was not further increased by renewed fusions. Occasionally, the stabilized hybrids only contained approximately the DNA content of the corresponding wild‐type strain. Investigation of the early events after fusion revealed spontaneous mitotic segregation with a high frequency. The benomyl‐induced mitotic segregation pattern of the hybrid clones was not uniform. In some clones certain markers did not segregate any longer. This probably indicates the loss of the respective chromosome. The inability of P. guilliermondii fusion products to form stable hybrids with the expected high DNA content may be attributed to either the aneuploidy of the fusion partners or a specific mitotic apparatus of this yeast.