bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Liquefaction Potential and Dynamic Properties of Silty Sand Using Cyclic Triaxial Testing
Authors: Sitharam TG , GovindaRaju L , Srinivasa Murthy BR 
Published: February 2005

Abstract
The recent earthquake that struck the Bhuj area of Gujarat State in India on 26 January 2001 has caused almost a total devastation of several hundred buildings in villages and cities. Liquefaction triggered by this earthquake caused major damage to structures resting on Loose to medium dense sands. This earthquake provides grave illustrations of the importance of understanding the seismic response of such deposits. Recent developments in numerical analyses for nonlinear dynamic responses of ground due to strong earthquake motions have increased the demand for dynamic soil properties corresponding not only at small strain level but also at large strain level. In this paper, the results of cyclic undrained tests are presented for liquefied soil close to the epicenter of the Bhuj earthquake. From these tests the dynamic properties were estimated at large strain levels of 0.5 % to 4 %. The modulus and damping estimated using cyclic triaxial testing at large strain levels might serve as a key factor for assessment of ground response due to earthquakes.
Measurement and Simulation of Damage to Long Light-Weight Packages in the FedEx 3-Day Saver Parcel Delivery Service
Authors: Singh SP , Burgess G , Mingerink C 
Published: February 2005

Abstract
Packaged goods are shipped daily using the single parcel distribution systems offered by carriers such as FedEx, UPS, and USPS. Through these shipments, packages are exposed to dynamic forces that result in punctures, creases, scuffs, tape failures, and corner and edge crushes. This study measured the frequency and severity of these and other types of damage that occur to long light-weight packages in the FedEx single parcel environment (3-Day Saver). The results of this study showed that the most frequent type of damage in one-way shipments were creases, which represented 61.5 % of the damage events observed. Corner crushes followed with 16.7 %, edge crushes with 6.8 %, punctures with 6.7 %, and tape failures with 1.7 % of the total damages observed. Based on 58 packages shipped, the average box experienced 8.4 creases, 2.3 corner crushes, 0.9 punctures, 0.9 edge crushes, 0.8 others, 0.2 tape failures, and 0.1 scuffs per shipment. Based on these results, a test protocol was developed to reproduce this damage. The test includes vibration testing, compression testing with an edge hazard, at drop onto a point hazard, tip-over test onto an edge hazard, and corner and edge drop tests. The proposed tests correlated well with actual damage.
The Use of an Alternative Method for Fracture Toughness Evaluation on Different Materials
Authors: Guardiola M , Bernal C , Martínez R , Cassanelli A 
Published: February 2005

AbstractThrough this paper an alternative procedure to obtain fracture toughness parameters on blunt-notched samples rather than on standard sharp-notched samples has been applied to several materials which display different fracture behavior. An aluminum alloy, an austempered ductile iron (ADI), and two different polymeric materials, polyamide 6 and poly(methyl methacrylate) (PMMA), were tested. The use of the alternative methodology allows simplification and cost reduction in fracture toughness evaluation. For the aluminum alloy, the fracture parameter obtained by this method was 16 % lower than that determined using ASTM standard methodology with data scatter similar to that reported in literature. For the ADI, fracture toughness values from blunt-notched samples were close to those obtained using standard test samples, showing low sensitivity to the changes in the crack tip diameter. For polyamide 6, the alternative methodology led to a toughness value within the same range of the values obtained from the traditional technique. In the case of the PMMA, the KIc values obtained from both methods showed good agreement.
Three‐Year Post‐Placement Survival of Implants Mobile at Placement
Authors: Orenstein Ira H. , Tarnow Dennis P. , Morris Harold F. , Ochi Shigeru 
Published: February 2005

Background: Although rigid fixation of endosseous implants at the time of placement is generally thought to be a prerequisite for successful osseointegration, the Dental Implant Clinical Research Group (DICRG) of the Department of Veterans Affairs has reported on implants that integrated despite being mobile at placement. The present study examines the frequency of osseointegration and the 36‐month post‐placement survival of implants mobile at placement in a prospective, multicenter, longitudinal clinical study of more than 3,000 implants conducted by the DICRG.Methods: A total of 3,111 implants of 6 different designs were placed in all jaw regions in more than 800 patients at 32 study centers. At the time of this report, 2,770 of these implants had been followed for 36 months post‐placement. They included 89 implants that were mobile at placement. Data for demographic variables, implant coating, bone quality, incision type, bone augmentation, and antibiotic usage were recorded. An electronic hand‐held probe was used to measure mobility at uncovering and at regular follow‐up intervals.Results: Eighty‐nine of 2,770 inserted implants were mobile at placement. Results are reported for two periods: from placement to 36 months and from prosthetic loading to 36 months. The latter method eliminated early failures and resulted in substantially higher scores for both mobile implants at placement (95.9% survival from prosthetic loading to 36 months post‐placement versus 79.8% from placement to 36 months) and implants not mobile at placement (98.4% versus 93.4%). Mobility at placement was significant to 3‐year survival (P <0.001). Hydroxyapatite (HA) coating improved the performance of implants mobile at placement (91.8% for HA‐coated versus 53.6% for non‐HA) and those not mobile at placement (97.2% for HAcoated versus 87.4% for non‐HA). Radiographic findings suggested that crestal bone response around implants which were mobile versus immobile at placement was similar.Conclusions: Although implant stability at the time of placement is clearly desirable as seen in the superior 3‐year survival of stable implants, it may not be an absolute prerequisite to osseointegration or to longterm survival. Several factors may influence the decision to remove or replace a mobile implant. HA‐coating significantly improved the performance of both mobile and immobile implants at placement to 3 years post‐placement (P <0.001). Ann Periodontol 2000;5:32‐41.
Genes of Periodontopathogens Expressed During Human Disease
Authors: Song Yo‐Han , Kozarov Emil V. , Walters Sheila M. , Cao Sam Linsen , Handfield Martin , Hillman Jeffrey D. , Progulske‐Fox Ann 
Published: February 2005

Background: Since many bacterial genes are environmentally regulated, the screening for virulence‐associated factors using classical genetic and molecular biology approaches can be biased under laboratory growth conditions of a given pathogen, because the required conditions for expression of many virulence factors may not occur during in vitro growth. Thus, technologies have been developed during the past several years to identify genes that are expressed during disease using animal models of human disease. However, animal models are not always truly representative of human disease, and with many pathogens, there is no appropriate animal model.Methods: A new technology, in vivo‐induced antigen technology (IVIAT) was thus engineered and tested in our laboratory to screen for genes of pathogenic organisms induced specifically in humans, without the use of animal or artificial models of infection. This technology uses pooled sera from patients to probe for genes expressed exclusively in vivo (or ivi, in vivo‐induced genes). IVIAT was originally designed for the study of Actinobacillus actinomycetemcomitans pathogenesis, but we have now extended it to other oral pathogens including Porphyromonas gingivalis.Results: One hundred seventy‐one thousand (171,000) clones from P. gingivalis strain W83 were screened and 144 were con‐ firmed positive. Over 300,000 A. actinomycetemcomitans clones were probed, and 116 were confirmed positive using a quantitative blot assay.Conclusion: IVIAT has proven useful in identifying previously unknown in vivo‐induced genes that are likely involved in virulence and are thus excellent candidates for use in diagnostic and therapeutic strategies, including vaccine design. Ann Periodontol 2002;7:38‐42.
Periodontal Disease Increases the Risk of Preterm Delivery Among Preeclamptic Women
Authors: Riché Estelle L. , Boggess Kim A. , Lieff Susi , Murtha Amy P. , Auten Richard L. , Beck James D. , Offenbacher Steven 
Published: February 2005

Background: Preterm births are a major cause of neonatal morbidity and mortality, and represent an important public health issue. About 30% of preterm births are due to medical conditions of the mother or the fetus, among which preeclampsia plays a major role. We have previously reported that maternal periodontal disease enhances the risk for preterm delivery and preeclampsia. Our current objective was to determine whether maternal periodontal disease increases the risk for preterm delivery among preeclamptic women.Methods: Women were enrolled prior to their twenty‐sixth week of gestation. Periodontal status was assessed at baseline and defined as healthy, mild, or moderate/severe. Repeat examinations were performed at delivery to assess changes in periodontal status.Results: A cohort of 1,020 women was studied, 47 of whom had preeclampsia. A strong association between periodontal disease status at enrollment and rate of premature delivery was observed among preeclamptic women after adjusting for the major risk factors for preterm delivery, including maternal race; age; marital status; WIC (women, infants, children program) or food stamps; insurance; previous preterm delivery; and chorioamnionitis. Among preeclamptic women, 49.3% with mild periodontal disease and 82.6% with moderate to severe disease delivered preterm (hazard ratios [HR] 4.11 and 11.0, respectively). Periodontal disease worsening during pregnancy in preeclamptic women was also associated with an increased risk of preterm births (HR 8.44).Conclusion: These results suggest that mothers with preeclampsia may be at greater risk for preterm delivery if periodontal disease is present early in pregnancy or progresses during pregnancy. Ann Periodontol 2002;7:95‐101.
Periodontal Disease as a Risk Factor for Adverse Pregnancy Outcomes. A Systematic Review
Authors: Scannapieco Frank A. , Bush Renee B. , Paju Susanna 
Published: February 2005

Background: Recent studies have implicated a variety of infections, including periodontal diseases, as risk factors for adverse pregnancy outcomes such as prematurity and low birth weight.Rationale: A number of studies have shown that bacterial vaginosis is related to preterm and/or low birth weight (PT/LBW), which continues to be a significant cause of infant morbidity and mortality. It is also possible that other infectious processes, including periodontal diseases, contribute to PT/LBW. This systematic review examines the literature to determine the possible relationship between PT/LBW and periodontal diseases.Focused Question: Does prevention/control of periodontal disease as compared to controls have an impact on the initiation/progression of adverse pregnancy outcomes?Search Protocol: MEDLINE, pre‐MEDLINE, MEDLINE Daily Update, and the Cochrane Oral Controlled Trials Register were searched to identify published studies that related variables associated with PT/LBW and periodontal disease. Searches were performed for articles published through October 2002.Inclusion criteria: Randomized controlled clinical trials (RCTs), case‐control, and cohort studies were included. Study populations included mothers, with or without periodontal disease, who gave birth to preterm and/or mature infants. The interventions considered included all forms of periodontal therapy.Exclusion criteria: Only studies on humans were included.Data Collection and Analysis: Due to study heterogeneity, meta‐analysis was not possible.

Main Results

Of the over 660 studies identified, 12 (6 case‐control, 3 cross‐sectional and longitudinal, and 3 intervention) met inclusion and exclusion criteria and were included in the analysis.

While several studies implicated periodontal disease as a risk factor for PT/LBW, few assessed the impact of the prevention and treatment of periodontal disease on outcomes.

Several epidemiologic studies did not support periodontal disease as a risk factor for PT/LBW

Reviewers' Conclusions

Periodontal disease may be a risk factor for PT/LBW

Additional longitudinal, epidemiologic, and interventional studies are needed to validate this association and to determine whether it is causal.

It is not yet clear whether periodontal diseases play a causal role in adverse pregnancy outcomes.

Preliminary evidence to date suggests that periodontal intervention may reduce adverse pregnancy outcomes.

Ann Periodontol 2003;8:70‐78
The Informativeness of Attachment Loss on Tooth Mortality
Authors: Hujoel P.P. , Löe H. , Anerud A. , Boysen H. , Leroux B.G. 
Published: February 2005

Background: In periodontal clinical trials, clinical attachment level measurements are commonly used as surrogates for tooth loss. Conclusions regarding treatment efficacy in these trials are valid if: 1) the surrogate is informative on tooth loss, and 2) the surrogate captures the effect of treatment on tooth loss. The goal of this study was to evaluate the first criterion: Are serial clinical attachment loss measurements informative on overall tooth mortality?Methods: Young Norwegian men (aged 17 to 35) were first examined in 1969 (n=565) and followed for 26 years with examinations in 1971 (n=381), 1973 (n=292), 1975 (n=245), 1981 (n=228), 1988 (n=202), and 1995 (n=223). Several aspects of the serial attachment loss measurements were related to tooth mortality risk using statistical models that take into account the time‐dependent changes of the clinical attachment loss measurements.Results: The results provided evidence that moderate attachment losses were informative on tooth mortality. Both the lifetime cumulative attachment loss, as well as attachment loss since young adulthood, of ≥2 mm or ≥3 mm was informative on tooth mortality. Tooth mortality risk increased as the attachment loss increased; loss ≥3 mm at the buccal or mesial site increased tooth mortality risk, by 91% (relative risk, 1.91; 95% confidence interval, 1.01‐3.60) and 270% (RR, 3.70; 95% CI, 1.83‐7.49), respectively.Conclusions: We concluded that clinical attachment loss was moderately informative on overall tooth mortality in this Norwegian population. Since this finding has now been demonstrated in 3 different populations, the focus of further research should be on evaluating whether the second criterion for a valid surrogate is satisfied: Does clinical attachment loss capture the effect of periodontal treatments on tooth loss? J Periodontol 1999;70: 44‐48.
Relationship of the Subgingival Microbiota to a Chairside Test for Aspartate Aminotransferase in Gingival Crevicular Fluid
Authors: Wong Man‐Ying , Lu Chia‐Lin , Liu Cheing‐Meei , Hou Lein‐Tuan , Chang Wen‐Kuei 
Published: February 2005

Background: The aim of the present study was to evaluate the association between the occurrence of certain specific periodontal pathogens and aspartate aminotransferase (AST) levels in gingival crevicular fluid (GCF).Methods: Thirty systemically healthy subjects with moderate to advanced periodontitis were selected. Within each subject, the AST contents of GCF from sites with probing depth between 5 mm and 7 mm were measured using a chairside colorimetric test. AST‐positive site refers to one that had an AST level ≥800 μIU. Subgingival plaque samples from one AST‐positive and one negative site were collected for microbiological examination. One site with probing depth ≤3 mm and no gingival inflammation was selected as a healthy control. Clinical parameters of the chosen sites, including the plaque index and gingival index scores, probing depth, and clinical attachment level were measured. Culture and immunofluorescence (IF) were used for detecting common periodontal pathogens, including Actinobacillus actinomycetemcomitans, Peptostreptococcus micros, Campylobacter rectus, Eikenella corrodens, Fusobacterium nucleatum, Capnocytophaga species, Prevotella intermedia, Prevotella melaninogenica, and Porphyromonas gingivalis. Logistic regression was used to analyze the correlation between the AST test and certain specific pathogens.Results: The GCF scores and total cultivable bacterial counts were higher in AST‐positive sites than either AST‐negative or healthy sites. The prevalence and proportions of specific periodontal pathogens such as C. rectus, E. corrodens, F. nucleatum, Capnocytophaga species, P. intermedia, and P. gingivalis were significantly higher in positive than in negative sites. In analyzing the correlation of the proportion of 6 pathogens with the AST test by logistic regression, only P. gingivalis showed a significant positive correlation. The odds ratio of having a high proportion of P. gingivalis in the presence of a positive AST test was 1.21.Conclusions: The present study showed that at AST‐positive sites, there is a higher prevalence and higher proportion of certain periodontal pathogens. Although only the correlation of P. gingivalis and AST values was statistically significant, the results imply that certain periodontal pathogens may be associated with elevation of AST levels in GCF. J Periodontol 1999;70: 57‐62.
A Novel Insertion Sequence Increases the Expression of Leukotoxicity in Actinobacillus actinomycetemcomitans Clinical Isolates
Authors: He Tao , Nishihara Tatsuji , Demuth Donald R. , Ishikawa Isao 
Published: February 2005

Background: The expression of leukotoxin varies among Actinobacillus actinomycetemcomitans strains and is dependent in part on the structure of the ltx promoter region. Highly leukotoxic strains, characterized by a 530 base pair (bp) deletion within the ltx promoter, have been associated with juvenile periodontitis in the United States and Europe. In the present study, we analyzed the ltx promoter structure to elucidate whether A. actinomycetemcomitans from Japanese periodontitis patients exhibits the highly toxic phenotype.Methods: Forty‐five A. actinomycetemcomitans strains, including 43 clinical isolates, the highly leukotoxic strain JP2, and a minimally leukotoxic strain 652 were used in the study. The ltx promoter structure was analyzed by polymerase chain reaction (PCR), with oligonucleotide primers focusing the ltx promoter region, and nucleotide sequencing. Leukotoxic activity was determined by trypan blue exclusion. Western blotting assay was performed to detect the level of leukotoxin polypeptide.Results: A 495 bp PCR product was amplified from JP2, a 1025 bp product from 652 and 41 of the clinical isolates, and a 1926 bp product from the remaining two clinical isolates (Aa IS1, Aa IS2). Sequencing of the 1926 bp PCR fragment showed that it was similar to that of strain 652 but contained an 886 bp region that was identified as an insertion sequence (IS). Both AaIS strains expressed high levels of leukotoxicity, similar to strain JP2. In addition, a mutant (Aa IS–) that had lost the IS element expressed a significantly lower level of leukotoxicity compared with AaIS strains. Furthermore, the levels of leukotoxin polypeptide expressed by these strains were consistent with their whole cell leukotoxicity.Conclusions: A. actinomycetemcomitans clinical strains which were isolated from Japanese periodontitis patients do not possess the 530 bp ltx promoter deletion. The results of this study suggest that a high level of leukotoxin expression correlates with the insertion of the transposable DNA element. J Periodontol 1999;70:1261‐1268.
Possible Potentiation of Toxins From Prevotella intermedia, Prevotella nigrescens, and Porphyromonas gingivalis by Cotinine
Authors: Sayers Nicola M , James Jacqueline A. , Drucker David B. , Blinkhorn Anthony S. 
Published: February 2005

Background: Smoking is a recognized risk factor for the initiation and progression of periodontitis. However, the mechanism by which smoking induces its negative effects on the periodontium is not clear. This study aimed to test the hypothesis that synergy may occur between cotinine and bacterial products isolated from 3 putative periodontopathogens.Methods: A chick embryo toxin assay was used to investigate bacterial toxins (cell‐free extracellular toxins and cellfree cell lysates) from 5 species with and without cotinine. A total of 9 putative periodontopathogens (3 species) and 2 non‐oral controls (2 species) were studied. The periodontal species were: Prevotella intermedia (n = 4), Prevotella nigrescens (n = 4), and Porphyromonas gingivalis (n = 1). The control species tested were: Staphylococcus aureus (n = 1) and Escherichia coli (n = 1).Results: The toxicity kill was significantly greater than expected by simple addition alone (P <0.05, Fisher's exact test) between cotinine (800 ng/ml) and 1) the cell‐free extracellular toxins of P. nigrescens MH1 and 2) the cellfree cell lysates of P. intermedia MH2. Synergy occurred with cotinine plus the cell‐free extracellular toxins in all but 3 periodontal isolates, and the cell‐free cell lysates in all but 2 periodontal isolates. Cotinine significantly (P<0.05, Fisher's exact test) enhanced the effects of cell‐free extracellular toxins and cell lysates from one control species (E. coli), but not the other (S. aureus).Conclusions: These findings indicate that synergy in an in vitro assay can occur between cotinine and toxins from putative periodontopathogens. This may be one important mechanism by which smoking increases the severity of periodontitis. J Periodontol 1999;70:1269‐1275.
Bacterial Adhesion of Actinobacillus actinomycetemcomitans Serotypes to Titanium Implants: SEM Evaluation.A Preliminary Report
Authors: Ökte Emel , Sultan Nedim , Doğan Başak , Asikainen Sirkka 
Published: February 2005

Background: In this study, the adherence ability of Actinobacillus actinomycetemcomitans serotypes to titanium implant surfaces was evaluated to demonstrate if any selective adherence occurs according to the serotypes of the microorganism.Methods: The study material included 3 reference strains of A. actinomycetemcomitans serotypes a, b, and c (ATCC 29523, ATCC 43718, ATCC 33384) and 2 clinical isolates of A. actinomycetemcomitans serotypes and e (IDH 781, IDH 1705), together with commercially available titanium blade implants. For each strain, bacterial suspensions with identical concentrations (5 × 107 cells/ml) were prepared and 0.5 ml of each was added on to the implant surfaces, which had been precoated with glycine‐bovine serum albumin (BSA). After incubation at 37°C for 60 minutes in 5% CO2 in air, the implants with attached bacteria were prepared for scanning electron microscopic (SEM) observations. Bacterial adhesion was quantified on the textured body surfaces of the implants, and results were statistically analyzed with analysis of variance followed by Duncan's test. The surface ultrastructure of the bacterial cells was also evaluated descriptively.Results: The tested strains adhered to implant surfaces in different quantities. Serotype a (ATCC 29523) showed the highest adherence affinity (statistically significant, P<0.01). When compared with each other, serotypes b, c, and d (ATCC 43718, ATCC 33384, and IDH 781) attached equally well, whereas serotype (IDH 1705) had a statistically significant low adherence capability.Conclusions: It is suggested that in vitro A. actinomycetemcomitans adhesion to implant surfaces is strain dependent. J Periodontol 1999;70:1376‐1382