bluuebunny/crossref_metadata_2025_split huggingface dataset:
Highly efficient, polymerizable, sulfur‐containing photoinitiator comprising a structure of planar N‐phenylmaleimide and benzophenone for photopolymerization
Authors: Wang Hongyu , Wei Jun , Jiang Xuesong , Yin Jie 
Published: April 2006

AbstractIn a continuation of research on chemically bonded photoinitiators comprising a structure of planar N‐phenylmaleimide (NPMI) and benzophenone (BP), a novel, highly efficient, polymerizable, sulfur‐containing photoinitiator, 4‐[(4‐maleimido)thiophenyl]benzophenone (MTPBP), was synthesized by the introduction of an NPMI group into BP. Another chemically bonded photoinitiator, 4‐[(4‐maleimido)phenoxy]benzophenone (MPBP), was selected to evaluate its photoefficiency. The results showed that MTPBP possessed a greatly redshifted UV maximal absorption and a very weak fluorescence emission. Electron spin resonance spectra indicated that the CS bond in its molecule underwent photolysis reactions to generate radicals to initiate the polymerization. Three representative types of different functionality monomers—methyl methacrylate, 1,6‐hexanediol diacrylate, and trimethylolpropane triacrylate—were chosen to be initiated through dilatometry and differential scanning photocalorimetry with unsaturated tertiary amine N,N‐dimethylaminoethyl methacrylate as the coinitiator. The results showed surprisingly high efficiency of MTPBP due to the mutual influence between NPMI and BP as in their physical mixtures and photolysis reactions at the CS bond. Both MPBP and MTPBP behaved with similar regularity toward different monomers. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3738–3750, 2006
Hybrid Comminution with High‐Pressure Roller and Stirred Bead Milling
Authors: Wang Yanmin , Forssberg Eric , Lin Peng 
Published: April 2006

AbstractThis paper presents the experimental results on the wet grinding of a moist calcium carbonate material in a hybrid comminution system, which consists of a high pressure roller mill (HPRM) and a subsequent stirred bead mill. The results show that the pre‐treatment of the material with the HPRM could result in energy saving and efficient size reduction during the subsequent wet ultra‐fine grinding in the stirred bead mill. It was found that the level of fineness of the ground product is dramatically influenced by the number of repeat passes of pre‐grinding in the HRPM. The formation of micro‐cracks in the particles under compressive loads was discussed in order to elucidate the role of the HRPM as a pre‐grinder in the hybrid comminution system. The simulated breakage behaviors of various irregular shaped particles indicate that the tortuous micro‐crack propagation paths and the crack branching behavior are related to the heterogeneity of the particle and the stress distributions.
Multiple molecular dynamics simulations of human p450 monooxygenase CYP2C9: The molecular basis of substrate binding and regioselectivity toward warfarin
Authors: Seifert Alexander , Tatzel Stephan , Schmid Rolf D. , Pleiss Jürgen 
Published: April 2006

AbstractTo examine the molecular basis of activity and regioselectivity of the clinically important human microsomal cytochrome P450 (CYP) monooxygenase 2C9 toward its substrate warfarin, 22 molecular dynamics simulations (3–5 ns each) were performed in the presence and absence of warfarin. The resulting trajectories revealed a stable protein core and mobile surface elements. This mobility leads to the formation of two surface channels in the region between F‐G loop, B′ helix/B‐B′ loop, β1‐sheet, and between helices F and I and the turn in the C‐terminal antiparallel β‐sheet in the presence of warfarin. Besides the nonproductive state of the CYP2C9 warfarin complex captured in the crystal structure, three additional states were observed. These states differ in the shape of the substrate binding cavity and the position of the warfarin molecule relative to heme. In one of these states, the 7‐ and 6‐positions of warfarin contact the heme with a marked geometrical preference for position 7 over position 6. This modeling result is consistent with experimentally determined regioselectivity (71 and 22% hydroxylation in positions 7 and 6, respectively). Access to the heme group is limited by the core amino acids Ala297, Leu362, Leu366, and Thr301, which therefore are expected to have a major impact on regioselectivity. In addition, modeling predicts that autoactivation of warfarin is sterically hindered. Our study demonstrates how the combination of mobile surface and rigid core leads to interesting properties: a broad substrate profile and simultaneously a high regioselectivity. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Adverse Effects of Citrate/Gold Nanoparticles on Human Dermal Fibroblasts
Authors: Pernodet Nadine , Fang Xiaohua , Sun Yuan , Bakhtina Asya , Ramakrishnan Aditi , Sokolov Jonathan , Ulman Abraham , Rafailovich Miriam 
Published: April 2006

AbstractNanoscale engineering is one of the most dynamically growing areas at the interface between electronics, physics, biology, and medicine. As there are no safety regulations yet, concerns about future health problems are rising. We investigated the effects of citrate/gold nanoparticles at different concentrations and exposure times on human dermal fibroblasts. We found that, as a result of intracellular nanoparticle presence, actin stress fibers disappeared, thereby inducing major adverse effects on cell viability. Thus, properties such as cell spreading and adhesion, cell growth, and protein synthesis to form the extracellular matrix were altered dramatically. These results suggest that the internal cell activities have been damaged.
Total Parathyroidectomy Without Autotransplantation for Renal Hyperparathyroidism: Experience with a qPTH‐controlled Protocol
Authors: Lorenz Kerstin , Ukkat Jörg , Sekulla Carsten , Gimm Oliver , Brauckhoff Michael , Dralle Henning 
Published: April 2006

AbstractBackgroundControversy regarding the optimal surgical treatment for secondary hyperparathyroidism (sHPT) continues. Subtotal parathyroidectomy (PTX) with a small remnant and total parathyroidectomy with autotransplantation prevail, although impaired by considerable recurrence rates. Concerns about postoperative management and long‐term supplementation prevent broader acceptance of total parathyroidectomy without autotransplantation.Materials and MethodsThe standardized surgical procedure with intraoperative PTH assessment (qPTH) included cervical thymectomy, histological proof of four parathyroid specimens and obligatory cryopreservation of parathyroid tissue in all 23 patients undergoing total PTX without autotransplantation. Whenever qPTH did not normalize, complete cervical exploration of ectopic sites was performed. Another 64 patients with subtotal PTX for sHPT served as comparison for the postoperative course.ResultsThere were 13 primary and 10 completion (5 persistent, 5 recurrent sHPT) total PTX with 14 concurrent thyroid resections performed. Mean preoperative PTH was 1.351 pg/ml (12–72 pg/ml) and serum calcium was 2.5 mmol/l (2.25–2.5 mmol/l). PTH showed intraoperative normalization in 15 patients and a 50% PTH reduction from preoperative values in all. Postoperative course was not significantly different from the subtotal PTX group and showed PTH within the normal range for 5 patients (4 < 35 pg/ml), 7 with PTH < 12 pg/ml, and 4 without measurable PTH. In 4 patients PTH did not normalize postoperatively. Serum calcium levels were below normal in all patients: < 2.25 mmol/l in 9, < 2.00 mmol/l in 7, and <1.8 mmol/l in 6 patients. Only 1 patient required intermittent early postoperative i.v. calcium supplementation, 6 patients received oral calcium and vitamin D supplement for low calcium levels, but no severe hypocalcemic symptoms were encountered. Mean postoperative hospital stay was 5 days. No recurrent laryngeal nerve palsies were encountered. Complications were two cervical bleedings following postoperative hemodialysis requiring evacuation.ConclusionsTotal PTX without autotransplantation proves to be an equally safe and successful procedure for sHPT as subtotal PTX or total PTX with autotransplantation. Measurable PTH after total PTX as demonstrated in this study, supports the idea of uncontrollable isolated cell nests that are inevitably prone to stimulated growth with time. Therefore, total PTX is superior with regard to prevention of recurrence. Adequate supplementation with calcium and vitamin D, often necessary after subtotal PTX to suppress inadequate PTH and protect from recurrence, will prevent severe hypocalcemia and with the modern aluminium‐diminishing dialysis regimen, development of adynamic bone disease appears less likely than feared. If necessary, cryopreserved parathyroid tissue can be autotransplanted on demand.
Associations of motor co‐ordination and attention with motor‐perceptual development in 3‐year‐old preterm and full‐term children who needed neonatal intensive care
Authors: Hemgren E. , Persson K. 
Published: April 2006

AbstractBackground  Children who have needed neonatal intensive care (NIC) are considered to be at risk for deficits such as developmental co‐ordination disorder and attention‐deficit/hyperactivity disorder. By assessing motor‐perceptual development, motor co‐ordination and attention already at 3 years of age, it might be possible to identify such deficits earlier than they are today.Aim  To investigate the motor‐perceptual development in a group of 202 NIC children but had no major impairments, to describe associations of deficits in co‐ordination and attention with motor‐perceptual delays, and to estimate the prevalence of NIC children with combined deficits together with a motor‐perceptual delay.Method  Co‐ordination and attention in children born very preterm (n = 57), moderately preterm (n = 75) and full‐term (n = 70) were observed according to a model for Combined Assessment of Motor Performance and Behaviour while they were assessed using a developmental scale, Motor‐Perceptual Development, 0–7 years, MPU.Results  In two out of 14 MPU areas, a larger proportion of very preterm than of moderately preterm and full‐term children had marked developmental delay. Overall, the proportion of NIC children having a motor‐perceptual delay increased with increasing incoordination and especially increasing lack of attention. Twenty‐one (11%) of the NIC children had different motor‐perceptual delays combined with pronounced incoordination and pronounced lack of attention.Conclusion  Deficits in co‐ordination and attention were associated with motor‐perceptual delays in areas important for daily living and development of academic skills. Therefore, to find children at risk for developmental co‐ordination disorder and attention‐deficit/hyperactivity disorder, assessments of co‐ordination and attention should be added to assessments of motor‐perceptual development in 3‐year‐old NIC children.
Fish assemblages in temporary ponds adjacent to ‘terra‐firme’ streams in Central Amazonia
Authors: PAZIN VICTOR F. V. , MAGNUSSON WILLIAM E. , ZUANON JANSEN , MENDONÇA FERNANDO P. 
Published: April 2006

Summary1. The effect of habitat structural features and physicochemical characteristics of the water on the composition and richness of fish assemblages in temporary ponds near streams were examined at three spatial scales: among ponds, among streams and between drainage basins, in a ‘terra‐firme’ (not subject to long‐term flooding) forest reserve in Central Amazonia.2. The fish assemblage in temporary ponds was composed of subsets of 18 small‐bodied species widely distributed in the reserve. The assemblages had a nested subset structure, where smaller ponds contained subgroups of the species found in larger ponds.3. Species composition and richness in temporary ponds were similar between drainage basins, although the fish assemblages in streams differed between basins.4. Fish assemblage structure was influenced by local factors related to habitat structure, such as pond area and depth, canopy cover and hydroperiod. Physicochemical characteristics of the water in the ponds were similar between drainage basins and had little detectable effect on the structure of pond fish assemblages.5. No correspondence was found between the composition, richness or abundance of fishes in the ponds and in stretches of the streams adjacent to the ponds. Therefore, it is not possible to predict the composition of these temporary pond fish assemblages from the fish assemblages found in adjacent streams.
Within‐lake variability in carbon and nitrogen stable isotope signatures
Authors: SYVÄRANTA JARI , HÄMÄLÄINEN HEIKKI , JONES ROGER I. 
Published: April 2006

Summary1. We assessed spatial and temporal variation in carbon and nitrogen isotopic signatures in different compartments of a single lake ecosystem. Stable isotope analyses were made on samples of particulate organic matter (POM), zooplankton, periphyton, macrophytes, macroinvertebrates and fish collected from several locations throughout the ice‐free period.2. No spatial variation in δ13C or δ15N values was found for pelagic samples of POM and zooplankton. However, pelagic δ15N signatures increased steadily through the summer resulting in an almost 6‰ average increase in POM and zooplankton. A concurrent decrease in epilimnetic nitrate concentrations suggested that the increase in δ15N of POM and zooplankton could have resulted from a progressive 15N‐enrichment of the available inorganic nitrogen pool as the size of this pool was reduced.3. Significant spatial variation in isotopic ratios was observed within littoral and profundal communities. Some spatial differences were likely related to lake‐specific characteristics, such as a major inlet and a small harbour area and some were interconnected with temporal events.4. Marked differences between spring and autumn δ15N and δ13C values of fish at one site probably reflected a spring spawning immigration from a larger downstream lake and also indicated limited dispersal of these immigrants.5. Our results indicate that restricted sampling of ecosystem components from lakes may provide misleading single values for the isotope end members needed for quantitative uses of stable isotopes in mixing models and for estimating trophic position. Hence we strongly advise that studies of individual lakes, or multiple lake comparisons, that utilise stable isotope analyses should pay more attention to potential within lake spatial and temporal variability of isotope ratios.
Penile duplex pharmaco‐ultrasonography of cavernous arteries in men with erectile dysfunction and generalized atherosclerosis
Authors: Bocchio Massimo , Scarpelli Piero , Necozione Stefano , Pelliccione Fiore , Spartera Carlo , Francavilla Felice , Francavilla Sandro 
Published: April 2006

SummaryAssessment of cavernosal perfusion in men with erectile dysfunction (ED) relies on Doppler spectrum analysis of pharmachologically stimulated peak systolic velocity (sPSV) in cavernous arteries but its accuracy in identifying men affected by a cavernosal perfusion disorder correlated with atherosclerosis remains undefined. We estimated by B‐mode ultrasound, the accuracy of sPSV of cavernous arteries to identify ED with an expected cavernosal perfusion disorder. This was predicted by an elevated intima‐media thickness (IMT) of common carotid arteries, a reference methodology to estimate the degree of generalized atherosclerosis, in men exposed to vascular risk factors (VRFs). sPSV and IMT were evaluated in 269 men with ED, 49 had no VRFs, 100 were overweight with/or without hyperlipidaemia, 120 were affected by type 2 diabetes and/or essential hypertension. sPSV was significantly lower (p < 0.05) in patients with VRFs associated with atherosclerosis (IMT ≥ 1 mm) (n = 39) than in men with no VRFs and no atherosclerosis (n = 49). sPSV correlated negatively with age (p < 0.0001), with serum% of glycated haemoglobin (p = 0.010) and with carotid artery IMT (p = 0.013). An sPSV ≤ 30 cm/sec, the cut‐off value which showed at receiver operating characteristic curve analysis the combined highest value of sensitivity and specificity, correctly identified only 57% of men in whom a cavernosal perfusion disorder was expected based on the presence of carotid artery IMT ≥ 1 mm combined to the exposure to VRFs. The ultrasonographic evaluation of sPSV had a very limited accuracy in discriminating ED with an expected cavernosal perfusion disorder, based on the presence of a generalized atherosclerosis in men with VRFs.
Costimulatory Molecules and Cytokine Production by T Lymphocytes in Common Variable Immunodeficiency Disease
Authors: Pons J. , Ferrer J. M. , Martínez‐Pomar N. , Iglesias‐Alzueta J. , Matamoros N. 
Published: April 2006

AbstractCommon variable immunodeficiency (CVID) is a heterogeneous syndrome characterized by hypogammaglobulinaemia and recurrent infections. Although early works pointed to a primary B‐lymphocyte defect as a cause of the disease, a failure in T‐lymphocyte cooperation has also been suggested. T cells exert their costimulatory function through either membrane costimulatory molecules or secreted cytokines, both having an influence in the development of the humoral response. The aim of our study was to evaluate whether an abnormal expression and induction of costimulatory molecules or alterations in the production of cytokines by T cells cause deficient T/B cooperation in CVID patients. We studied the expression and upregulation of costimulatory molecules (CD28, CD40L/CD154 and CTLA‐4/CD152) and production of cytokines (IL‐2, IL‐4, IL‐6, IL‐10, IFN‐γ and TNF‐α) in purified T lymphocytes from CVID patients stimulated with optimal doses of anti‐CD3 or suboptimal doses of anti‐CD3 and anti‐CD28. Stimulated T cells from CVID patients expressed normal levels of CD28, CD40L/CD154 and CTLA‐4/CD152 when compared with controls. Except for higher production of IL‐4 after stimulation with anti‐CD3, T cells of CVID patients produced similar amounts of cytokines compared with controls. An imbalance between costimulatory molecules expression (CD28, CD40L/CD154 and CTLA‐4/CD152) and cytokine production by T cells does not explain a deficient cooperation between T and B cells in this group of CVID patients.
Nematode Infection in Alymphoplasia (aly) Mice: Worm Species‐Dependent Differential Effect of Defects of the Gut‐Associated Lymphatic Tissue System
Authors: Morimoto M. , Yamauchi Y. , Shinkawa S. , Ishiwata K. , Hayashi T. 
Published: April 2006

AbstractMice homologous for the alymphoplasia mutation (aly) show the systemic absence of secondary lymphoid tissues, with disorganized splenic architecture, including the absence of the germinal centre and follicular dendritic cells. In this study, we examined the influence of defects of gut‐associated lymphoid tissue (GALT), such as Peyer's patches and the mesenteric lymph nodes, on the host response to helminth infection in aly/aly mice. The present study showed that most of the worms were expelled by day 7 after Nippostrongylus brasiliensis infection in both control aly/+ and aly/aly mice. In aly/aly mice, the number of peripheral blood eosinophils, intestinal goblet cells and mucosal mast cells were increased by N. brasiliensis infection in aly/aly mice to the same level as in the controls. Conversely, aly/aly mice developed more severe Heligmosomoides polygyrus infections than control aly/+ mice, as demonstrated by increased faecal egg counts, with reduced immune responses such as the numbers of intestinal goblet cells and mucosal mast cells. These results suggested that the dependency of GALT in activation of Th2 responses against gastrointestinal nematodes was different depending on the species of nematode.
The structure and kinematics of substrate entrainment into high‐concentration sandy turbidites: a field example from the Gorgoglione ‘flysch’ of southern Italy
Authors: BUTLER ROBERT W. H. , TAVARNELLI ENRICO 
Published: April 2006

AbstractSandy turbidites commonly show evidence for significant dynamic coupling with their substrate. The resulting deformation can be described using structural kinematic methods, linked to palaeoflow indicators, to better understand the links between flow and entrainment processes. A field example from the syn‐orogenic Gorgoglione Flysch, a succession of upper Miocene turbidites deposited into a deforming array of thrust‐top basins in the southern Apennine thrust belt, Italy, is described. The succession contains metre‐scale packages of alternating sandy turbidites and shales but is notable for containing > 100 m thick, massive sandbodies. These are structureless apart from sporadic horizons of aligned mud clasts. Commonly, the substrate beneath the massive sandbodies is deformed, with minor folds and thrusts verging in the direction of palaeoflow determined from tool marks and flutes at the base of these sandbodies. Structural studies from the base of a selected massive sandbody have identified that the substrate mud has been injected upwards, with flames sheared over in the direction of palaeoflow. Thus the substrate has deformed and become entrained during emplacement of the massive sandy body. At some locations, the substrate can be traced into the overlying deposit, with substrate clay beds becoming boudinaged and entrained into the sandbody. Analysis of the orientation of the mud clasts indicates that this bed disruption and incorporation into the sandy massive‐bed turbidite was an organized, viscous process. These features indicate that significant shear stress was partitioned out of the flow and onto the substrate. The incorporation and disruption of substrate into the sandbody suggest that post‐disruption strains increase upwards – implying that displacement gradients increased into the flow. These behaviours, showing variations in strain partitioning between the flow and its substrate, are explored in terms of evolving flow dynamics and substrate rheology.
Seroepidemiology of leptospirosis in southern Vietnamese children
Authors: Thai Khoa T. D. , Binh Tran Quang , Giao Phan Trong , Phuong Hoang Lan , Hung Le Quoc , Nam Nguyen Van , Nga Tran Thanh , Goris Marga G. A. , De Vries Peter J. 
Published: April 2006

SummaryObjective  To estimate the seroprevalence of human leptospirosis in southern Vietnam.Methods  All pupils (n = 961) of two primary schools in two communes in southern Vietnam were screened for the presence of serum Leptospira immunoglobulin (Ig)G. Leptospira IgM was tested in 92 randomly selected samples. IgM and IgG were tested with a commercially available enzyme‐linked immunosorbent assay (ELISA).Results  Leptospira IgG was found in 123 (12.8%, 95% CI: 10.8–15.1) children with a male:female ratio of 1.5:1. At the age of 7 years the prevalence was 11%. Log‐linear binary regression of the IgG seroprevalence by age showed a mean seroconversion rate of 1.5% (95% CI: 1.23–1.75) per year. Five (5.4%, 95% CI: 2.3–12.1) samples were definitely positive for IgM. Presence of serum Leptospira IgG antibodies was significantly associated with swimming in rivers (RR: 1.745, 95% CI: 1.117–2.724) and wading through water (RR 1.793, 95% CI: 1.181–2.722).Conclusion  Our data emphasize the importance of leptospirosis among children in Vietnam, despite the absence of severe disease, and stress the need for adequate and cheap diagnostics.