bluuebunny/crossref_metadata_2025_split huggingface dataset:
Localized Quadrilateral Coarsening
Authors: Daniels Joel , Silva Claudio T. , Cohen Elaine 
Published: August 2009

AbstractIn this paper we introduce a coarsening algorithm for quadrilateral meshes that generates quality, quad‐only connectivity during level‐of‐coarseningcreation. A novel aspect of this work is development and implementation of a localized adaptation of thepolychordcollapse operator to better control and preserve important surface components. We describe a novel weighting scheme for automatic deletion selection that considers surface attributes, as well as localized queue updates that allow for improved data structures and computational performance opportunities over previous techniques. Additionally, this work supports optional and intuitive user controls for tailored simplification results.
Approximating Gradients for Meshes and Point Clouds via Diffusion Metric
Authors: Luo Chuanjiang , Safa Issam , Wang Yusu 
Published: August 2009

AbstractThe gradient of a function defined on a manifold is perhaps one of the most important differential objects in data analysis. Most often in practice, the input function is available only at discrete points sampled from the underlying manifold, and the manifold is approximated by either a mesh or simply a point cloud. While many methods exist for computing gradients of a function defined over a mesh, computing and simplifying gradients and related quantities such as critical points, of a function from a point cloud is non‐trivial.In this paper, we initiate the investigation of computing gradients under a different metric on the manifold from the original natural metric induced from the ambient space. Specifically, we map the input manifold to the eigenspace spanned by its Laplacian eigenfunctions, and consider the so‐called diffusion distance metric associated with it. We show the relation of gradient under this metric with that under the original metric. It turns out that once the Laplace operator is constructed, it is easier to approximate gradients in the eigenspace for discrete inputs (especially point clouds) and it is robust to noises in the input function and in the underlying manifold. More importantly, we can easily smooth the gradient field at different scales within this eigenspace framework. We demonstrate the use of our new eigen‐gradients with two applications: approximating / simplifying the critical points of a function, and the Jacobi sets of two input functions (which describe the correlation between these two functions), from point clouds data.
Mechanism of the persistent sodium current activator veratridine‐evoked Ca2+elevation: implication for epilepsy
Authors: Fekete Ádám , Franklin Laura , Ikemoto Takeshi , Rózsa Balázs , Lendvai Balázs , Sylvester Vizi E. , Zelles Tibor 
Published: August 2009

AbstractAlthough the role of Na+in several aspects of Ca2+regulation has already been shown, the exact mechanism of intracellular Ca2+concentration ([Ca2+]i) increase resulting from an enhancement in the persistent, non‐inactivating Na+current (INa,P), a decisive factor in certain forms of epilepsy, has yet to be resolved. Persistent Na+current, evoked by veratridine, induced bursts of action potentials and sustained membrane depolarization with monophasic intracellular Na+concentration ([Na+]i) and biphasic [Ca2+]iincrease in CA1 pyramidal cells in acute hippocampal slices. The Ca2+response was tetrodotoxin‐ and extracellular Ca2+‐dependent and ionotropic glutamate receptor‐independent. The first phase of [Ca2+]irise was the net result of Ca2+influx through voltage‐gated Ca2+channels and mitochondrial Ca2+sequestration. The robust second phase in addition involved reverse operation of the Na+–Ca2+exchanger and mitochondrial Ca2+release. We excluded contribution of the endoplasmic reticulum. These results demonstrate a complex interaction between persistent, non‐inactivating Na+current and [Ca2+]iregulation in CA1 pyramidal cells. The described cellular mechanisms are most likely part of the pathomechanism of certain forms of epilepsy that are associated withINa,P. Describing the magnitude, temporal pattern and sources of Ca2+increase induced byINa,Pmay provide novel targets for antiepileptic drug therapy.
The effect of nitroglycerin tolerance on oxidative stress and anaerobic sulfur metabolism in rat tissues
Authors: Dudek Magdalena , Bilska Anna , Bednarski Marek , Iciek Małgorzata , Kwiecień Inga , Sokołowska‐Jeżewicz Maria , Filipek Barbara , Włodek Lidia 
Published: September 2009

AbstractThe present results indicated that tolerance to nitroglycerin (glycerin trinitrate, GTN) increased the hepatic and renal level of reactive oxygen species, malondialdehyde, and glutathione peroxidase (POx) and decreased superoxide dismutase activity, whereas non‐protein thiols remained unchanged in both organs. In the liver (but not in the kidney) glutathioneS‐transferase (GST), catalase and rhodanese activities decreased and the sulfane sulfur level also dropped. Unlike in the liver, γ‐glutamyl transpeptidase (γGT) activity in the kidney declined. On the other hand, hepatic S‐nitrosothiols (SNT) rose while renal SNT declined. As no concomitant changes in the nitric oxide (NO) level were observed in either organ, the results suggested that under nitroglycerin tolerance NO was stored in the liver in the form of SNT. In conclusion, the results obtained in the liver and kidney confirm the involvement of oxidative stress in the pathomechanism of GTN tolerance, and reveal the diverse effects of this phenomenon on the γGT and GST activity and SNT level in both organs. We observed for the first time that GTN tolerance could be accompanied by the disruption of hepatic anaerobic cysteine metabolism, associated with sulfane sulfur and rhodanese activity.
Acetaldehyde and the Hypothermic Effects of Ethanol in Mice
Authors: Closon Catherine , Didone Vincent , Tirelli Ezio , Quertemont Etienne 
Published: August 2009

Background: Acetaldehyde, the first metabolite of ethanol, has been suggested to be involved in many behavioral effects of ethanol. However, few studies have investigated the hypothermic effects of acetaldehyde or the contribution of acetaldehyde to ethanol‐induced hypothermia. The aim of the present study is to better understand the hypothermic effects of acetaldehyde and the possible contribution of acetaldehyde in ethanol‐induced hypothermia, especially under conditions leading to acetaldehyde accumulation.Methods: Female Swiss mice were injected intraperitoneally with ethanol and acetaldehyde and their rectal temperatures were measured with a digital thermometer at various time points after the injections. Experiment 1 compared the hypothermic effects of various acetaldehyde doses (0 to 300 mg/kg) with a reference dose of ethanol (3 g/kg). Experiment 2 tested the effects of a pretreatment with the aldehyde dehydrogenase (ALDH) inhibitor cyanamide (25 mg/kg) on ethanol‐ and acetaldehyde‐induced hypothermia. In experiments 3 and 4, mice received a combined pretreatment with cyanamide and the alcohol dehydrogenase (ADH) inhibitor 4‐Methylpyrazole (10 mg/kg) before the injection of ethanol or acetaldehyde.Results: Acetaldehyde at doses between 100 and 300 mg/kg induced significant hypothermic effects, but of shorter duration than ethanol‐induced hypothermia. The inhibition of ALDH enzymes by cyanamide induced a strong potentiation of both ethanol‐ and acetaldehyde‐induced hypothermia. The pretreatment with 4‐MP prevented the potentiation of ethanol‐induced hypothermia by cyanamide, but slightly increased the potentiation of acetaldehyde‐induced hypothermia by cyanamide.Conclusions: The results of the present study clearly show that acetaldehyde has hypothermic properties in mice at least at relatively high concentrations. Furthermore, the accumulation of acetaldehyde following ALDH inhibition strongly enhanced the hypothermic effects of ethanol. These latter results confirm the hypothermic properties of acetaldehyde and show that acetate, the next step in ethanol metabolism, is not involved in these hypothermic effects. Finally, the experiment with 4‐MP indicates that the potentiating effects of cyanamide are mediated by the peripheral accumulation of acetaldehyde, which then reaches the brain to induce a severe hypothermia.
Comparison of Adaptive Behavior in Children With Heavy Prenatal Alcohol Exposure or Attention‐Deficit/Hyperactivity Disorder
Authors: Crocker Nicole , Vaurio Linnea , Riley Edward P. , Mattson Sarah N. 
Published: August 2009

Background:  Adaptive behavior, the ability to respond successfully to everyday demands, may be especially sensitive to the effects of heavy prenatal alcohol exposure. Similar adaptive dysfunction is common in other developmental disorders including attention‐deficit/hyperactivity disorder (ADHD). ADHD is frequently present in alcohol‐exposed children and this overlap in clinical presentation makes identification of alcohol‐exposed children difficult. Direct comparison of children with prenatal alcohol exposure and ADHD may yield distinct patterns of cognitive and behavioral performance and add to growing knowledge of the neuropsychological and behavioral profile of prenatal alcohol exposure. Therefore, the aim of the current study was to compare adaptive behavior in children with histories of heavy prenatal alcohol exposure (ALC), nonexposed children with ADHD (ADHD), and typically developing controls (CON).Methods:  Sixty‐five children (ALC = 22, ADHD = 23, CON = 20) were selected from a larger ongoing study of the behavioral teratogenicity of alcohol. Alcohol‐exposed and control participants were selected to match the ADHD subjects on age, sex, socioeconomic status, and race/ethnicity. Caregivers were administered the Vineland Adaptive Behavior Scales, a semi‐structured interview, and were asked to rate their child’s behavior on 3 domains of adaptive function. Data were analyzed using regression techniques.Results:  Relative to controls, children in both the ALC and ADHD groups showed adaptive behavior deficits on all 3 domains and children in the ALC group were significantly more impaired than the ADHD group on the daily living skills domain. Within the ALC group, socialization standard scores were lower at older ages. This negative relationship between age and standard scores in the ALC group was also observed on the communication domain, a finding not previously reported.Conclusions:  This study suggests that both children with prenatal alcohol exposure and children with ADHD show impairments in adaptive function relative to controls, but that the pattern of impairment differs between these clinical groups. Adaptive ability in children with prenatal alcohol exposure is characterized by an arrest in development, as evidenced by a lack of improvement with age in socialization and communication scores. In contrast, children with ADHD exhibit a developmental delay in adaptive ability as their scores continued to improve with age, albeit not to the level of control children. Continued research focused on elucidating the patterns of deficits that exist in alcohol‐exposed children ultimately will lead to improved differential diagnosis and effective interventions.
Supply and Demand of Board‐certified Emergency Physicians by U.S. State, 2005
Authors: Sullivan Ashley F. , Ginde Adit A. , Espinola Janice A. , Camargo Carlos A. 
Published: August 2009

AbstractObjectives:  The objective was to estimate the emergency medicine (EM) board‐certified emergency physician (EP) workforce supply and demand by U.S. state.Methods:  The 2005 National Emergency Department Inventories‐USA provided annual visit volumes for U.S. emergency departments (EDs). We estimated full‐time equivalent (FTE) EP demand at each ED by dividing the actual number of visits by the estimated average EP visit volume (3,548 visits/year) and then summing FTEs by state. Our model assumed that at least one EP should be present 24/7 in each ED. The number of EM board‐certified EPs per state was provided by the American Board of Medical Specialties (American Board of Emergency Medicine, American Board of Pediatrics) and the American Osteopathic Board of Emergency Medicine. We used U.S. Census Bureau civilian population estimates to calculate EP population density by state.Results:  The supply of EM board‐certified EPs was 58% of required FTEs to staff all EDs nationally and ranged from 10% in South Dakota to 104% in Hawai’i (i.e., there were more EPs than the estimated need). Texas and Florida had the largest absolute shortages of EM board‐certified EPs (2,069 and 1,146, respectively). The number of EM board‐certified EPs per 100,000 U.S. civilian population ranged from 3.6 in South Dakota to 13.8 in Washington, DC. States with a higher population density of EM board‐certified EPs had higher percent high school graduates and a lower percent rural population and whites.Conclusions:  The supply and demand of EM board‐certified EPs varies by state. Only one state had an adequate supply of EM board‐certified EPs to fully staff its EDs.
Clinical outcome of submerged vs. non‐submerged implants placed in fresh extraction sockets
Authors: Cordaro Luca , Torsello Ferruccio , Roccuzzo Mario 
Published: August 2009

AbstractAim: The aim of this study was to compare the clinical outcome of submerged vs. non‐submerged tapered implants placed into fresh extraction sockets.Materials and methods: A prospective, controlled, multicenter, randomized, clinical trial has been performed in two centers in Rome and Torino (Italy). Thirty healthy patients were recruited according to the following inclusion criteria: need for an immediate post extraction implant, ages between 18 and 70, horizontal defect depth <2 mm, smokers <10 cigarettes/day and absence of any circumstance or condition that could represent contraindications to implant surgery. The patients were randomly allocated to submerged or non‐submerged treatment groups immediately after flap elevation and tooth extraction. Submerged implants were exposed 8 weeks after the first surgery; all implants were loaded with provisional restorations 12 weeks after the first surgery and with definitive restoration 12 weeks thereafter. Clinical and radiographic parameters were evaluated at baseline, at implant loading and at the 1‐year follow‐up visit.Results: The results showed statistically significant differences between the two groups in the mean value of keratinized tissue (KT) height after surgery that was significantly reduced for submerged implants when compared with transmucosal implants (mean reduction of KT at year follow‐up: T group 0.2 mm, S group 1.3 mm; P=0.007).Conclusion: Similar outcomes were found for submerged and non‐submerged implants placed in fresh extraction sockets with a horizontal peri‐implant defect smaller than 2 mm, except for a reduction of KT in the submerged group. Either with a submerged or a non‐submerged procedure, 1 mm of mean soft tissue recession is seen after 1 year when compared with the pre‐extraction situation.
Inferior alveolar canal course: a radiographic study
Authors: Liu Tie , Xia Bing , Gu Zhiyuan 
Published: August 2009

AbstractObjectives: To describe the morphology and course of the inferior alveolar canal (IAC) as it appears in digital panoramic radiographs.Materials and methods: Three hundred and eighty‐six digital rotational panoramic radiographs (OPG) were studied using the Clinview Software (6.1.3.7 version, Instrumentarium). Among the 386 radiographs, 86 radiographs with 5‐mm steel balls were used to calculate the magnification.Results: The average magnification of radiographs in this study was 7.24±7.55%. The course of IAC as seen in the panoramic radiograph may be classified into four types: (1) linear curve, 12.75%, (2) spoon‐shaped curve, 29.25%, (3) elliptic‐arc curve, 48.5%, and (4) turning curve, 9.5%. On panoramic radiographs, the IAC appeared closest to the inferior border of the mandible in the region of the first molar. In relation to the teeth, on panoramic radiographs, the IAC appeared closest to the distal root tip of the third molar and furthest from the mesial root tip of the first molar.Conclusion: In the OPG, there are four types of IAC: linear, spoon shape, elliptic‐arc, and turning curve. The data found in the study may be useful for dental implant, mandibule surgery, and dental anesthesia. The limitations of the panoramic radiograph in depicting the true three‐dimensional (3D) morphology of the IAC are recognized, computed tomography (CT) and cone beam (CB)3D imaging being more precise.
Resonance frequency measurements in vivo and related surface properties of magnesium‐incorporated, micropatterned and magnesium‐incorporated TiUnite®, Osseotite®, SLA® and TiOblast® implants
Authors: Sul Young‐Taeg , Jönsson Jörgen , Yoon Goui‐Seong , Johansson Carina 
Published: August 2009

AbstractObjective: To investigate implant stability using resonance frequency measurements of topographically changed and/or surface chemistry‐modified implants in rabbit bone.Material and methods: Six groups of microstructured, screw‐shaped titanium implants: two oxidized, cation‐incorporated experimental implants [Mg implants and MgMp implants with micropatterned thread flanges (80–150 μm wide and 60–70 μm deep)] and four commercially available clinical implants (TiUnite®, Osseotite®, SLA®, and TiOblast®) were installed in 10 rabbit tibia for 6 weeks. The surface properties of the implants were characterized in detail using several analytical techniques. Implant stability was measured using a resonance frequency analyzer (Osstell™).Results: Surface characterization of the implants revealed microstructured, moderately rough implant surfaces varying 0.7–1.4 μm in Sa (mean height deviation), but with clear differences in surface chemistry. After 6 weeks, all implants showed statistically significantly higher increases in implant stability. When compared with one another, MgMp implants showed the most significant mean implant stability quotient (ISQ) value relative to the others (P≤0.016). In terms of increment (ΔISQ) in implant stability, MgMp implants showed a significantly greater value as compared with Osseotite® (P≤0.005), TiOblast® (P≤0.005), TiUnite® (P≤0.005), SLA® (P≤0.007), and Mg implants (P≤0.012). In addition, transducer direction dependence of resonance frequency analysis (RFA) measurements was observed such that the differences in the mean ISQ values between longitudinal and perpendicular measurements were significant at implant placement (P≤0.004) and after 6 weeks (P≤0).Conclusion: The present study found that implant surface properties influence RFA measurements of implant stability. Surface chemistry‐modified titanium implants showed higher mean ISQ values than did topographically changed implants. In particular, cation (magnesium)‐incorporated micropatterns in MgMp implants may play a primary role in ΔISQ.
Five‐year evaluation of the influence of keratinized mucosa on peri‐implant soft‐tissue health and stability around implants supporting full‐arch mandibular fixed prostheses
Authors: Schrott Alexander René , Jimenez Monik , Hwang Jae‐Woong , Fiorellini Joseph , Weber Hans‐Peter 
Published: August 2009

AbstractBackground: The question of the importance of keratinized mucosa around dental implants for the prevention of peri‐implant disease could not be answered in the relevant literature so far.Objective: To investigate the influence of peri‐implant keratinized mucosa on long‐term peri‐implant soft‐tissue health and stability over a period of 5 years.Material and methods: A total of 386 mandibular dental implants were placed in 73 completely edentulous patients, and subsequently restored with fixed full‐arch prostheses. At prosthesis delivery (baseline) and after 3, 6, 12, 18, 24, 36, 48 and 60 months, modified plaque index (mPlI), modified sulcus bleeding index (mBI), distance between implant shoulder and mucosal margin (DIM) and width of peri‐implant keratinized mucosa (KM) were recorded. Statistical analysis included multivariate logistic regression, multivariate ordinal logistic regression, generalized estimating equations and Bonferroni's correction.Results: Fifty‐eight patients with 307 implants completed the 5‐year study. Statistically significantly higher plaque accumulation on lingual sites (mean mPlI 0.67, SD 0.85), bleeding tendencies on lingual sites (mean mBI 0.22, SD 0.53) and larger soft‐tissue recession on buccal sites (mean DIM −0.69 mm, SD 1.11 mm) were found when the width of KM was <2 mm, compared to sites with≥2 mm of KM (mean mPlI 0.40, SD 0.68, P=0.001; mean mBI 0.13, SD 0.41, P<0.01; mean DIM −0.08 mm, SD 0.86 mm, P<0.001). The width of keratinized mucosa had no effect on bleeding tendency or plaque accumulation on buccal sites (P>0.05).Conclusion: In patients exercising good oral hygiene and receiving regular implant maintenance therapy, implants with a reduced width of <2 mm of peri‐implant keratinized mucosa were more prone to lingual plaque accumulation and bleeding as well as buccal soft‐tissue recession over a period of 5 years.
Guided bone regeneration using rhGDF‐5‐ and rhBMP‐2‐coated natural bone mineral in rat calvarial defects
Authors: Schwarz Frank , Ferrari Daniel , Sager Martin , Herten Monika , Hartig Brigitte , Becker Jürgen 
Published: August 2009

AbstractObjectives: The aim of the present study was to assess the influence of either recombinant human growth and differentiation factor 5 (rhGDF‐5)‐ or recombinant human bone morphogenetic protein 2 (rhBMP‐2)‐coated natural bone mineral (NBM) on guided bone regeneration in a rat calvarial defect model.Material and methods: Two monocortical critical‐size calvarial defects (diameter 6 mm, depth 1.5 mm) were prepared in a total of 90 rats each (n=180 defects) and randomly allocated to the following groups: (1) NBM+collagen membrane (BG), (2) rhBMP‐2+NBM+BG, (3) rhGDF‐5+NBM+BG, (4) autogenous bone (AB)+BG, or (5) untreated control (C). At 1, 2, 4, 8, 16, and 24 weeks, dissected blocks were processed for histological [e.g. area (mm2) of mineralized tissue (MT)] and immunohistochemical (osteocalcin – OC, angiogenesis – TG) analysis.Results: At 2 weeks, both coated NBM groups exhibited the formation of a thin hard tissue bridge underneath the BG. All test groups revealed significantly higher mean MT values than the C group at 24 weeks. rhBMP‐2+NBM+BG‐treated defects revealed significantly higher mean MT values in comparison with the AB+BG (8 and 24 weeks), NBM+BG (2 and 4 weeks), and rhGDF‐5+NBM+BG (2, 16, and 24 weeks) groups, respectively. Immunoreactions to either OC or TG were comparable in all test groups.Conclusion: It was concluded that (i) all treatment procedures investigated supported bone regeneration at 24 weeks and (ii) rhBMP‐2 might have the potential to improve the outcome of healing, particularly during the early stages of healing.