bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protonation of Tris(iminocatecholato) Complexes of Gallium(III) and Titanium(IV)
Authors: Albrecht Markus , Burk Simon , Stoffel Ralf , Lüchow Arne , Fröhlich Roland , Kogej Michael , Schalley Christoph A. 
Published: February 2007

AbstractThe coordination behaviour of the chiral tren‐type tripodal ligand 3‐H6 with gallium(III) and titanium(IV) ions was investigated and it was found that only mononuclear complexes are formed. In the presence of Na+, one of the cations acts as a template and is bound inside the “cap” of [Na(3)M]n– (M = Ga, n = 2; M = Ti, n = 1). If no such cation is present, three protons are bound to the iminocatechol units in order to prevent repulsion between lone pairs at nitrogen and oxygen. To minimize the charge repulsion between the protonated imines of [H3(3)M]n+ (M = Ga, n = 0; M = Ti, n = 1), an enaminone/chinomethine mesomeric structure becomes important. The adoption of this unusual mesomeric form by the iminocatecholates was supported by computational methods. In further investigations, we found, that the addition of protons (H2SO4) to the dinuclear (catecholimine)titanium helicate K4[(4)3Ti2] leads to protonation of the imine part of the iminocatechol. An excess of acid results in the hydrolysis of the complexes as well as of the imine units. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Assessing Guest Selectivity within Metallacrown Host Compartments
Authors: Lim Choong‐Sun , Van Noord Annabel Cutland , Kampf Jeff W. , Pecoraro Vincent L. 
Published: February 2007

Abstract15‐MC‐5 complexes associate in the solid state to form chiral compartments capable of binding guests. Using small molecular yardsticks, we are able to assess the size restrictions of these structures. Dicarboxylate guests that are too short to span the GdIII ions are stabilized by solvates that hydrogen bond to the uncoordinated carboxylate, while guests that are too long destroy the weakly associated structure. We also demonstrate that all that is required for guest encapsulation is unsaturation of the chain connection carboxylates rather than necessitating the presence of aromaticity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Estimating joint tail probabilities of river discharges through the logistic copula
Authors: de Waal D. J. , van Gelder P. H. A. J. M. , Nel A. 
Published: February 2007

AbstractIn flood analysis, apart from extreme precipitation or sudden snow melt, also the duration or persistence of high water levels needs proper description. The purpose of this paper is to estimate tail probabilities from the joint distribution of variables such as one‐day annual maximum river discharges and its aggregate seven‐day annual maximum discharges. An application will be shown to the river Rhine in The Netherlands. The marginal distributions of the annual maxima (AM) exceeding certain thresholds are assumed to be bounded Strict Pareto and the logistic copula is used for the joint distribution. The main methodological issue discussed is the fitting of the logistic copula within a Bayesian framework. The estimation of parameters are obtained through a Markov Chain Monte Carlo simulation. In this respect, the paper provides a method for selecting the univariate and bivariate thresholds. Copyright © 2007 John Wiley & Sons, Ltd.
Generalised algorithm of novel space vector modulation: forN‐level three‐phase voltage source inverter
Authors: Chekireb Hachemi , Berkouk El Madjid 
Published: February 2007

AbstractThis paper concerns the development of a generalised algorithm of a novel space vector modulation (SVM) forN‐level three‐phase voltage source inverter. It is considering that the (N−1) DC input voltages of inverter are constant. The proposed method ensures initially the determination of theN3inverter switching states, the extraction of the redundancies to obtain 3N(N‐1) + 1 independent switching states and their organisation by sector in six distinct matricesWkwithk = (1, … ,6). After that, these matricesWkwithk = (2, … ,6) are ordered as the matrixW1related to the first sector. So, the research of the three closest vectors to the reference vector is carried out only in first sector and for this purpose, the equivalent reference vector is introduced which is resulting from the rotation by −(k−1)π/3 of the reference vector. The on‐line choice of the three vectors (three switching states of the inverter) is based on the distances between the equivalent reference vector and some vectors located in its vicinity in the (α,β) plane of the first sector. Moreover, a simple method for the calculation of the duty cycles for these three switching states is proposed which exploits directly the three shortest distances associated to these three selected vectors. The sequence of these three switching states over a sampling period is investigated in view to reduce the harmonic contents of the voltage output. The application is carried out on anN‐level three‐phase voltage source inverter, whereNis an arbitrary odd integer. Finally, the phase voltage and its harmonic spectrum provided by a three‐phaseN‐level inverter withN = (3,5,7,9,13,15) are presented to confirm the generalisation of this method. Copyright © 2007 John Wiley & Sons, Ltd.
A simple simulation method for torque and speed calculation of AC motors under distorted input waveforms
Authors: Kappatou Joya C. , Zarmakoupis Konstantinos , Safacas Athanasios N. 
Published: February 2007

AbstractThis paper presents a method of calculating in a simple, cheap and computational efficient way the steady‐state time variables of three‐phase induction or synchronous motors when only the data of the machine and a drawn waveform of its distorted stator input are given. Such waveforms can be considered as converter output voltage or current feeding the machine. According to this method the converter part for simulation can be omitted. The method has been implemented for an induction, as well as a synchronous machine under different cases of distorted voltage waveforms in the stator. Experimental and simulation results are in good agreement. Copyright © 2007 John Wiley & Sons, Ltd.
The Neolithic of the southern Levant
Authors: Twiss Katheryn C. 
Published: February 2007

AbstractThe Neolithic period of the southern Levant was an era of tremendous change. Over the course of the Neolithic, the gradual transition from foraging to agriculture involved not merely economic innovations, but also profound shifts in population size, social organization, and technology. This represents possibly the earliest, and certainly one of the earliest, instances of the transition to agriculture. The advent of farming altered human demography, health, and diversity; it shaped the spread of the world's dominant cultures, genes, and languages.1, 2 It recast humans' relationship with the natural world, increasing modification of the environment. It both enabled and required the development of new social structures as humans learned how to live in increasingly large and densely packed groups.These transformations were not easily achieved. This paper traces the development of the southern Levantine Neolithic through two thousand years of socioeconomic elaboration and expansion; a major social recalibration in the middle Neolithic; and a final millennium‐and‐a‐half of smaller‐scale and materially simpler adaptations.
Efficient multilocus association testing for whole genome association studies using localized haplotype clustering
Authors: Browning Brian L. , Browning Sharon R. 
Published: February 2007

AbstractWhole genome association studies are generating data sets with hundreds of thousands of markers genotyped on thousands of cases and controls. We show that whole genome haplotypic association testing with permutation to account for multiple testing is statistically powerful and computationally feasible on such data, using an efficient software implementation of a recently proposed method. We use realistic simulations to explore the statistical properties of the method, and show that for ungenotyped disease‐susceptibility variants with population frequencies of 5% or less the haplotypic tests have markedly better power than single‐marker tests. We propose a combined single‐marker and haplotypic strategy, in which both single‐marker and haplotypic tests are applied, with the minimum P‐value adjusted for multiple testing by permutation which results in a test that is powerful for detecting both low‐and high‐frequency disease‐susceptibility variants. Genet. Epidemiol. 2007. © 2007 Wiley‐Liss, Inc.
Phylochronology of early metazoans: combined evidence from molecular and fossil data
Authors: Qun Yang , Junye Ma , Xiaoyan Sun , Peiyun Cong 
Published: February 2007

AbstractTiming the evolutionary appearances of early Metazoa on Earth may rely on the combined information of fossil occurrences, molecular divergences and the geological background. Recent advances in the studies of Neoproterozoic and earliest Cambrian strata in South China and elsewhere, together with numerous works on molecular dating, provide an opportunity to draw a more precise timescale for the early metazoan evolution. This study presents a synthesis of available molecular and fossil dating results, placed in the palaeoenvironmental background, which leads to the recognition of the following time events for early metazoan cladogenesis: (1) Animal multicellularity occurred most probably during early to middle Neoproterozoic times (between ∼1000 and ∼660 Ma) during the geological period of gradual increase in oxygen content; (2) Eumetazoans and sponges (or sponge‐like organisms) parted from each other during the Neoproterozoic glaciation interval (ca. 750–580 Ma), but both experienced adaptive radiation after the glaciations as evidenced by the Doushantuo Biota (ca. 635–551 Ma); (3) A great metazoan radiation event (MRE) occurred during the late Ediacaran and earliest Cambrian periods (ca. 550–530 Ma), interpreted here as a metazoan radiation at higher taxonomic levels, as compared with the early Cambrian radiation representing one at lower taxonomic levels (lower than subphylum or class). In order to better constrain the phylochronology of early metazoans, we present evidence for the divergences of arthropod subgroups on the basis of molecular dating results and the fossil record. It is shown that the arthropod stem group diverged from its sister taxon at between ∼700 and ∼565 Ma and major arthropod subgroups originated coevally with MRE. The MRE is probably correlatable with the δ13C negative anomaly in the late Ediacaran Period.Although the phylochronology of early Metazoa is gradually emerging, a great deal of research still will be needed in the following directions in order to reduce uncertainties in, and discrepancies among, dating results: (1) Evaluate different molecular dating techniques so as to establish a proper set of standard procedures for dating early metazoan events; (2) Set up a standard set of fossil calibration points suitable for dating early metazoan divergences; (3) Use both molecular and fossil constraints as far as possible; (4) Place the time sequence in the geological and palaeoecological background so that one can visualize a logical evolutionary scenario. We suggest that the fossil record plus the geological background should serve to construct a general timeframe for evolution, while molecular dating will supplement and probably increase the precision of the chronology. Copyright © 2007 John Wiley & Sons, Ltd.
Prevalence and correlates of disruptive behavior in patients in Norwegian nursing homes
Authors: Testad I. , Aasland A. M. , Aarsland D. 
Published: February 2007

AbstractBackgroundAlthough Behavioral and Psychological Symptoms of Dementia (BPSD) increase with increasing dementia severity, and institutionalization of an individual with dementia is often caused by behavioral symptoms, relatively few studies have explored the prevalence of BPSD in nursing homes.ObjectiveTo study the prevalence and correlates of agitation in residents with dementia, in Norwegian nursing homes.MethodsThis study has taken place in dementia wards in four Norwegian nursing homes. To measure agitation in residents with dementia we used the Cohen‐Mansfield Agitation Inventory (CMAI), consisting of 29 agitation items. Dementia stage was measured by Functional Assessment Staging (FAST).ResultsTwo hundred and eleven patients (71% female) were included in the study: mean (SD) age 85.5 (8.4), FAST 4.7 (2.1), CMAI total sumscore 39.5 (12.6). Dementia was present in 167 (79%) subjects. Among those with dementia, weekly occurrence of at least one CMAI item (i.e. a score of 3 or higher) occurred in 75.4% (95% CI 68.4–81.4). Six of the items occurred at least weekly in 20% of the residents with dementia, and 11 of the items, including physical aggression, occurred in less than 5% of the residents. Agitation was associated with more severe dementia (p = 0.001), but not with age and gender.ConclusionSymptoms of agitation were common, but may nevertheless be lower compared to findings in other geographical areas. Further studies are warranted to test this hypothesis, and if confirmed, to explore possible causes for such differences. Copyright © 2007 John Wiley & Sons, Ltd.
The G-protein coupled bile salt receptor TGR5 is expressed in liver sinusoidal endothelial cells
Authors: Keitel Verena , Reinehr Roland , Gatsios Petros , Rupprecht Claudia , Görg Boris , Selbach Oliver , Häussinger Dieter , Kubitz Ralf 
Published: February 2007

AbstractSinusoidal endothelial cells (SEC) constitute a permeable barrier between hepatocytes and blood. SEC are exposed to high concentrations of bile salts from the enterohepatic circulation. Whether SEC are responsive to bile salts is unknown. TGR5, a G-protein–coupled bile acid receptor, which triggers cAMP formation, has been discovered recently in macrophages. In this study, rat TGR5 was cloned and antibodies directed against the C-terminus of rat TGR5 were developed, which detected TGR5 as a glycoprotein in transfected HepG2-cells. Apart from Kupffer cells, TGR5 was detected in SEC of rat liver. SEC expressed TGR5 over the entire acinus, whereas endothelial cells of the portal or central veins were not immunoreactive toward TGR5 antibodies. In isolated SEC, TGR5 mRNA and protein were detected by reverse transcription (RT) PCR, immunofluorescence microscopy, and Western blot analysis. Bile salts increased cAMP in isolated SEC and induced mRNA expression of endothelial NO synthase (eNOS), a known cAMP-dependent gene. In addition, bile acids activated eNOS by phosphorylation of eNOS at amino acid position 1177. In line with eNOS activation, bile acids induced NO production in liver slices. This is the first report on the expression of TGR5 in SEC.Conclusion:The data suggest that SEC are directly responsive toward specific bile salts. Regulation of eNOS in SEC by TGR5 connects bile salts with hepatic hemodynamics. This is of particular importance in cholestatic livers when bile salt concentrations are increased. (Hepatology 2007;45:695–704.)
MELD score as a predictor of liver failure and death in patients with acetaminophen-induced liver injury
Authors: Schmidt Lars E. , Larsen Fin Stolze 
Published: February 2007

Abstract

The Model for End-Stage Liver Disease (MELD) scoring system has been established as a reliable measure of short-term mortality risk in patients with end-stage chronic liver disease. The aim of this study was to evaluate the prognostic value of the MELD scoring as a predictor of fulminant hepatic failure (FHF) and death in patients with acetaminophen poisoning. Prospectively, serial measurements of the 3 MELD components—INR, bilirubin, and creatinine—were performed in 460 patients with acetaminophen-induced liver injury. Starting on the first day after the day of overdose, MELD score was significantly higher in patients who eventually developed hepatic encephalopathy (HE) than in those who did not. HE developed in 63 of 142 patients with a MELD score above 18 at 48-72 hours after the overdose (positive predictive value 44%) compared with 2 of 182 patients with a MELD score of 18 or below (negative predictive value 99%). Among 124 patients with FHF, a threshold MELD score of 33 on the day after the onset of HE had sensitivity of 60%, specificity of 69%, positive predictive value of 65%, and negative predictive value of 63%. However, the discriminative power of MELD score was not superior to that of INR alone or of the King's College Hospital criteria.

Conclusion

: MELD score may be useful as a predictor of FHF in patients admitted with acetaminophen toxicity. However, as a predictor of death from FHF, MELD score did not provide more information than the King's College Hospital criteria or INR alone. (Hepatology 2007;45:789–796.)
Diagnostic value of HSP70, glypican 3, and glutamine synthetase in hepatocellular nodules in cirrhosis
Authors: Di Tommaso Luca , Franchi Giada , Park Young Nyun , Fiamengo Barbara , Destro Annarita , Morenghi Emanuela , Montorsi Marco , Torzilli Guido , Tommasini Maurizio , Terracciano Luigi , Tornillo Luigi , Vecchione Raffaella , Roncalli Massimo 
Published: February 2007

Abstract

Hepatocellular nodules in cirrhosis include regenerative (large regenerative, LRN) and dysplastic (low and high grade, LGDN and HGDN) nodules, early and grade 1 HCC (eHCC-G1), and overt HCC. The differential diagnosis may be particularly difficult when lesions such as HGDN and eHCC-G1 are involved. We investigated the diagnostic yield of a panel of 3 putative markers of hepatocellular malignancy such as HSP70, glypican 3 (GPC3), and glutamine synthetase (GS). We selected 52 surgically removed nonmalignant nodules (15 LRNs, 15 LGDNs, 22 HGDNs) and 53 HCCs (10 early, 22 grade 1, and 21 grade 2-3) and immunostained them for HSP70, GPC3, and GS. The sensitivity and specificity of the individual markers for the detection of eHCC-G1 were 59% and 86% for GS, 69% and 91% for GPC3, and 78% and 95% for HSP70. We identified 2 main phenotypes: (1) all negative, seen in 100% LRN and LGDN, 73% HGDN and 3% eHCC-G1; (2) all positive, a feature detected in less than half the eHCC-G1. Using a 3-marker panel, when at least 2 of them, regardless which, were positive, the sensitivity and specificity for the detection of eHCC-G1 were respectively 72% and 100%; the most sensitive combination was HSP70+/GPC3+ (59%) when a 2-marker panel was used.

Conclusion:

The adopted panel of 3 markers is very helpful in distinguishing eHCC-G1 from dysplastic nodules arising in cirrhosis. (Hepatology 2007;45:725–734.)
Sertraline as a first-line treatment for cholestatic pruritus
Authors: Mayo Marlyn J. , Handem Iorna , Saldana Sandra , Jacobe Heidi , Getachew Yonas , Rush John A. 
Published: February 2007

Abstract

Pruritus is frequently the most debilitating symptom of cholestatic liver diseases. Moreover, existing therapies are often ineffective. Recent small, retrospective case series reports suggest that serotonin reuptake inhibitors can improve pruritus. This study was undertaken to establish the dose of sertraline and to evaluate its efficacy for cholestatic pruritus. Twenty one subjects with chronic pruritus due to liver disease (including primary biliary cirrhosis, primary sclerosing cholangitis, chronic hepatitis C, and postnecrotic cirrhosis) initially underwent an open-label, dose escalation to determine the dose with optimal efficacy and tolerability. After a washout period, 12 of the subjects entered a randomized, double-blind, placebo-controlled trial. Participants quantified their pruritus using a 0-10 visual analog scale, and pruritus was assessed for distribution, timing, degree of disability, and physical evidence of scratching. The optimum sertraline dose (75-100 mg/day) was well tolerated. In the controlled portion of the study, itch scores improved in patients taking sertraline, but worsened in patients taking placebo (

P

= 0.009). Changes in itch distribution, duration, direction, and physical evidence of scratching paralleled changes in the visual analog pruritus score.

Conclusion:

Sertraline seems to be an effective, well-tolerated treatment for pruritus due to chronic liver disease. These results suggest that serotonergic pathways are important in the perception of itch. (Hepatology 2007;45:666–674.)
Immunosuppression reactivates viral replication long after resolution of woodchuck hepatitis virus infection
Authors: Menne Stephan , Cote Paul J. , Butler Scott D. , Toshkov Ilia A. , Gerin John L. , Tennant Bud C. 
Published: February 2007

Abstract

Resolution of hepatitis B virus (HBV) infection is characterized by coordinated humoral and cellular immune responses. Immunity is durable over decades, protecting the host from reinfection and potential activation of residual HBV. Woodchucks infected at birth with woodchuck hepatitis virus (WHV) cleared viremia and developed antibodies to surface antigen (anti-WHs). Woodchucks became seronegative for anti-WHs 3-6 years later, but in some, WHV DNA was detected in serum, liver, and/or peripheral blood mononuclear cells (PBMCs). Those with WHV DNA had increased

in vitro

cellular immune responses to viral antigens, CD4 and CD8 markers, and Th1-type cytokines, suggesting active WHV-specific T lymphocytes. Immunosuppression for 12 weeks using cyclosporine A in such woodchucks resulted in transient reactivation of WHV replication. Serum of 1 woodchuck that became positive for WHV DNA during immunosuppression was inoculated into WHV-susceptible woodchucks, and a productive infection was demonstrated. The results indicate that after infection durable cellular immunity to WHV is essential for the long-term control of viral replication and is probably maintained by continuous priming from residual virus.

Conclusion:

These experimental observations demonstrate the potential of immunosuppression to reactivate HBV after resolution of infection. (Hepatology 2007;45:614–622.)
Revelation of simple and complex liver acini after portal transplantation of pancreatic islets or thyroid follicles in rats
Authors: Dombrowski Frank , Evert Matthias 
Published: February 2007

Abstract

The microarchitecture of the liver is still not completely understood although various concepts of structural liver organization have been proposed. Among them, Rappaport's liver acinus stands out as one of the most accepted models. The correctness of this model, however, has also been doubted, and its applicability is hampered by the fact that the outlines of the liver acinus are disguised and nobody was ever able to give visual evidence by “unmasking” a simple liver acinus from the surrounding liver tissue. After intraportal transplantation of pancreatic islets or thyroid follicles into diabetic or thyroidectomized rats, respectively, the transplants engraft in small portal tracts and morphologically alter the downstream liver tissue due to excessive hormone secretion. Using a combined approach of perfusion fixation, stereomicroscopy, and light microscopy, we demonstrate in this study that these foci of altered liver tissue represent simple and complex liver acini, exactly as described by Rappaport. We present stereomicroscopical and histological examples of all important cut levels of altered simple and complex liver acini, including their topographical relation to the supplying and draining vessels and to the “central vein” liver lobule. Moreover, by computer-aided reconstruction of serial semi-thin sections, we were able to present the first 3-dimensional images of simple and complex liver acini.

Conclusion:

Our results prove the correctness of Rappaport's acinus model and confirm the simple liver acinus as the principal microcirculatory unit of the liver. (Hepatology 2007;45:705–715.)