bluuebunny/crossref_metadata_2025 huggingface dataset:
The Determinants of Household Saving in China: A Dynamic Panel Analysis of Provincial Data
Authors: HORIOKA CHARLES YUJI , WAN JUNMIN
Published: November 2007

In this paper, we conduct a dynamic panel analysis of the determinants of the household saving rate in China using a life cycle model and panel data on Chinese provinces for the 1995–2004 period from China's household survey. We find that China's household saving rate has been high and rising and that the main determinants of variations over time and over space therein are the lagged saving rate, the income growth rate, (in many cases) the real interest rate, and (in some cases) the inflation rate. However, we find that the variables relating to the age structure of the population have the expected impact on the household saving rate in only one of the four samples. These results provide mixed support for the life cycle hypothesis as well as the permanent income hypothesis, are consistent with the existence of inertia or persistence, and imply that China's household saving rate will remain high for some time to come.
Enforcement Principles and Environmental Agencies: Principal-Agent Relationships in a Delegated Environmental Program
Authors: Atlas Mark
Published: November 2007

This article examines whether states shirked enforcement responsibilities in their principal-agent relationship with the federal government when implementing a delegated environmental program. It evaluates determinants of environmental enforcement stringency, particularly whether penalties were less when imposed by states than by the federal government. It analyzes 6,048 hazardous waste administrative penalties across 32 states and all U.S. Environmental Protection Agency Regions over 14 years. It finds that state penalties are typically substantially lower than federal penalties, and that penalty amounts are typically also related to the partisan composition of elected officials and the characteristics of enforcement actions, such as the type, seriousness, and number of violations. Factors such as the influence of organized interest groups, agency sensitivity to economic conditions or the economic importance of regulated industries, and environmentalist preferences of elected officials and the public are typically unrelated to enforcement stringency.
The Brownlow Committee, Regulation, and the Presidency: Seventy Years Later
Authors: Arnold Peri E.
Published: November 2007

Analyzing Robert E. Cushman’s study within the context of the Brownlow Report substantiates the argument that the immediate failure of the committee’s recommendations—and their influence in the longer term—is best explained within the conceptual framework of changing political orders in American political development. Seventy years later, the field has the historical perspective to see that the committee’s work was buffeted by tensions between competing political orders. Today, far from being just an interesting episode in American public administration, we see that the Brownlow Committee’s work on regulation, as much as work on executive organization, heralded and enabled a new era of presidential administration.
Administrative Management: Does Its Strong Executive Thesis Still Merit Our Attention?
Authors: Kaufman Herbert
Published: November 2007

Tasked with the responsibility of finding new and innovative ways of improving administrative management, Arthur W. Macmahon, James W. Fesler, and Herbert Emmerich creatively enriched the final report of the President’s Committee on Administrative Management with their analyses. But that is not the only reason for celebrating this work today. These documents still merit attention because they are historical landmarks that draw attention to the continuing tensions between Congress and the president over which branch of government should have control over executive branch agencies. This study makes the case for a strong executive in a manner that has rarely been as clearly and forcefully stated as it was in 1937. It reminds the field that policy decisions remain nothing but aspirations until they are turned into action. Reading this study is like reading any classic treatise on government—it generates thought.
The Whole‐of‐Government Approach to Public Sector Reform
Authors: Christensen Tom , Lægreid Per
Published: November 2007

In this article, the authors discuss “whole‐of‐government” initiatives as a reaction to the negative effects of New Public Management reforms such as structural devolution, “single‐purpose organizations,” and performance management but also as a reaction to a more insecure world. The authors examine what is meant by a “whole‐of‐government” approach and explore how this concept might be interpreted in analytical terms. The structural approach is contrasted with a cultural perspective and a myth‐based perspective. Finally, results, experiences, and lessons from the whole‐of‐government movement are discussed.
Percutaneous Pericardial Instrumentation for Catheter Ablation of Focal Atrial Tachycardias Arising from the Left Atrial Appendage
Authors: PHILLIPS KAREN P. , NATALE ANDREA , STERBA RICHARD , SALIBA WALID I. , BURKHARDT J. DAVID , WAZNI OUSSAMA , LIBERMAN LEONARDO , SCHWEIKERT ROBERT A.
Published: November 2007

Focal atrial tachycardias originating from the left atrial appendage present unique anatomic challenges for successful ablation. We describe the role of minimally invasive percutaneous epicardial mapping and ablation in the management of two patients with ectopic atrial tachycardias arising from the left atrial appendage following failure of a conventional endocardial approach to achieve cure.
Transcatheter Mitral Valve Repair for Functional Mitral Regurgitation: Coronary Sinus Approach
Authors: PIAZZA NICOLO , BONAN RAOUL
Published: November 2007

Mitral regurgitation has become recognized as an important health problem. More specifically, functional mitral regurgitation is associated with worse outcomes in heart failure, postmyocardial infarction, and perioperative coronary artery bypass surgery patients. Many patients with severe mitral regurgitation are denied or refused mitral valve surgery. A less invasive procedure with possibly fewer potential complications may thus be attractive for patients with severe mitral regurgitation. Devices used for coronary sinus (CS) mitral annuloplasty are directed toward patients with functional mitral regurgitation. Because of its easy accessibility and close relationship to the posterior mitral annulus (MA), alterations of the CS geometry with percutaneous devices may translate to displacement of the posterior annulus and correct mitral leaflet coaptation. This review will focus on the contemporary CS annuloplasty devices: (1) Edwards MONARC system; (2) Cardiac Dimensions CARILLON; and (3) Viacor Shape Changing Rods system. In addition, important information obtained from recent imaging studies describing the relationship between the CS, MA, and coronary arteries will be reviewed.
Intrapersonal and Interpersonal Factors Influencing Adolescents' Decisions About Having Sex: A Test of Sufficiency of the Theory of Planned Behavior1
Authors: Beadnell Blair , Wilsdon Anthony , Wells Elizabeth A. , Morison Diane M. , Gillmore Mary Rogers , Hoppe Marilyn
Published: November 2007

This study tested the theory of planned behavior's (TPB) expectation that attitudes, social norms, and self‐efficacy would mediate other variables' effects on intention for having sex and probability of having sex. Longitudinal data were collected from 790 high‐school‐aged adolescents. In an intrapersonal variable model, sensation seeking, alcohol use, hard work, smoking, and moral beliefs had mediated effects, but the last 2 also had direct effects (on intention and behavior, respectively). In an interpersonal model, school attachment had mediated effects, pressure to have sex had a direct effect on behavior, and parent communication and number of sexually active friends had both. Intrapersonal variable effects were better described by the TPB than those of interpersonal variables. Targeting distal psychosocial factors may enhance intervention efficacy.
College Students' Attitudes Toward Mental Illness: An Examination of the Stigma Process1
Authors: Phelan Julie E. , Basow Susan A.
Published: November 2007

Undergraduate students (96 female, 72 male) read 3 scenarios depicting either male or female characters with symptoms of depression, alcohol abuse, and common stress. Participants then completed measures assessing their attitudes about the character in the scenarios, as well as their level of social dominance orientation, empathy, adherence to traditional gender roles, and familiarity with mental illness. As predicted, participants who labeled the target mentally ill were more likely to view the target as dangerous. This, in turn, led to an increased desire for social distance. In contrast, empathy, although associated with increased likelihood of labeling, was associated with decreased desire for social distance. Implications of the results for reducing the social stigma of mental illness are discussed.
Below the Age of Consent: Influences on Moral and Legal Judgments of Adult–Adolescent Sexual Relationships1
Authors: Horvath Miranda A. H. , Giner‐Sorolla Roger
Published: November 2007

Sexual age‐of‐consent violations involving adult–adolescent relationships (AARs) are sometimes viewed with ambivalence by the media and are infrequently prosecuted. Two studies conducted in Britain (where the age of consent is 16) examined influences on disapproval of minimally presented AARs between a 14‐year‐old and a 30‐year‐old. In Study 1, AARs involving an older man were seen as more harmful and objectionable than those involving an older woman. A second study on a jury‐eligible adult population replicated Study 1's gender effects, and also found a difference between legal knowledge and personal belief that the older person had committed a crime. Gender effects in both studies were mediated by perceived harm and emotions.
Ambivalent Sexism and Misogynistic Rap Music: Does Exposure to Eminem Increase Sexism?1
Authors: Cobb Michael D. , Boettcher William A.
Published: November 2007

We evaluate the oft‐repeated but typically untested claim that rap music encourages sexism. We randomly assigned participants to 1 of 3 conditions: no music, misogynistic rap music, and nonmisogynistic rap music. The first study (treated as a pilot; N = 232) weakly demonstrated the differential impact of exposure on male and female participants, but our measures of sexism were unreliable. We then conducted a second study (N = 175) employing well‐validated (and more subtle) measures taken from the Ambivalent Sexism Inventory (ASI). While we replicated the weak differential impact of participants' sex, we also find that sexism increased after listening to nonmisogynistic rap music, especially among males. Implications for the debate about labeling and censoring rap music are discussed.
Effects of Bacillus thuringiensisδ‐endotoxin‐fed Helicoverpa armigera on the survival and development of the parasitoid Campoletis chlorideae
Authors: Sharma H.C. , Dhillon M.K. , Arora R.
Published: November 2007

With the deployment of transgenic crops expressing δ‐endotoxins from Bacillus thuringiensis (Bt) for pest management, there is a need to generate information on the interaction of crop pests with their natural enemies that are important for regulation of pest populations. Therefore, we studied the effects of the Bt δ‐endotoxins Cry1Ab and Cry1Ac on the survival and development of the parasitoid Campoletis chlorideae Uchida (Hymenoptera: Ichneumonidae) reared on Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) larvae fed on Bt toxin‐intoxicated artificial diet. The H. armigera larvae fed on artificial diet impregnated with Cry1Ab and Cry1Ac at LC50 (effective concentration to kill 50% of the neonate H. armigera larvae) and ED50 (effective concentration to cause a 50% reduction in larval weight) levels before and after parasitization resulted in a significant reduction in cocoon formation and adult emergence of C. chlorideae. Larval period of the parasitoid was prolonged by 2 days when fed on Bt‐intoxicated larvae. No adverse effects were observed on female fecundity. The observed effects appeared to be indirect in nature, because no Bt proteins were detected through enzyme‐linked immunosorbent assay in the C. chlorideae larvae, cocoons, or adults fed on Cry1Ab‐ or Cry1Ac‐treated H. armigera larvae. The effects of Bt toxin proteins on C. chlorideae were due to early mortality of H. armigera larvae, that is, before completion of parasitoid larval development.
Nutrient balance in medfly, Ceratitis capitata, larval diets affects the ability of the developing insect to incorporate lipid and protein reserves
Authors: Nestel David , Nemny‐Lavy Esther
Published: November 2007

The Mediterranean fruit fly [Ceratitis capitata Wiedemann (Diptera: Tephritidae)], or medfly, is mass produced in many facilities throughout the world to supply sterile flies for sterile insect technique programs. Production of sterile males requires large amounts of larval and adult diets. Larval diets comprise the largest economic burdens in the mass production of sterile flies, and are one of the main areas where production costs could be reduced without affecting quality and efficacy. The present study investigated the effect of manipulating diet constituents on larval development and performance. Medfly larvae were reared on diets differing in the proportions of brewer's yeast and sucrose. We studied the effect of such diets on the ability of pupating larvae to accumulate protein and lipids, and on other developmental indicators. Except for diets with a very low proportion of brewer's yeast (e.g., 4%), pupation and adult emergence rates were in general high and satisfactory. The ability of pupating larvae to accumulate lipid reserves and proteins was significantly affected by the sucrose and yeast in the diet, and by the proportion of protein to carbohydrates (P/C). In contrast to previous nutritional studies conducted with other insects, low P/C in medfly larval diets (with excess dietary carbohydrates) resulted in pupating medfly larvae having a relatively reduced load of lipids; medfly larvae protein contents in these diets were, as expected, relatively low. Similarly, high P/C ratios in the diet produced larvae with high protein and lipid contents. Differences with other insects may be due to differential post‐ingestion regulation where a high dietary carbohydrate diet reduces the lipogenic activity of the larvae, and induces a shift from lipid to glucose oxidation. Larvae reared on low P/C diets spent more time foraging in the diet than larvae maintained on a high P/C diet, suggesting a compensatory mechanism to complement nutrient intake. The results suggest that the content of brewer's yeast, the most expensive diet component, could be fine‐tuned without apparently affecting fly quality.
Hyaluronan fragments induce cytokine and metalloprotease upregulation in human melanoma cells in part by signalling via TLR4
Authors: Voelcker Verena , Gebhardt Carl , Averbeck Marco , Saalbach Anja , Wolf Verena , Weih Falk , Sleeman Jonathan , Anderegg Ulf , Simon Jan
Published: November 2007

Abstract:  Small fragments of the extracellular matrix component hyaluronic acid (sHA) are typically produced at sites of inflammation and tissue injury and have been shown to be associated with tumor invasiveness and metastasis. Here we report that exposure of human melanoma cells to sHA leads to nuclear factor kB (NFk‐B) activation followed by enhanced expression of matrix metalloprotease (MMP) 2 and interleukin (IL)‐8, factors that can contribute to melanoma progression. At the receptor level, we found that Toll‐like receptor (TLR) 4 is involved in this signalling pathway, similar to the case in dendritic and endothelial cells. Specifically, we found that melanoma cells expressed TLR4 on their surface in vivo and in vitro, and using specific siRNA, we could clearly demonstrate the functional importance of TLR4 in sHA‐triggered activation of IL‐8 expression in melanoma cells. Furthermore, we also found that sHA treatment enhanced the motility of melanoma cells, an effect that could again be blocked by TLR4‐specific siRNA. Together, our results suggest that sHA in melanoma might promote tumor invasiveness by inducing MMP‐ and cytokine‐expression, in part in a TLR4‐dependent manner, providing new insights into the relationship between cancer and innate immunity.
Effect of oral melatonin on the procoagulant response to acute psychosocial stress in healthy men: a randomized placebo‐controlled study
Authors: Wirtz Petra H. , Bärtschi Carmen , Spillmann Maria , Ehlert Ulrike , Von Känel Roland
Published: November 2007

Abstract:  Acute mental stress is a potent trigger of acute coronary syndromes. Catecholamine‐induced hypercoagulability with acute stress contributes to thrombus growth after coronary plaque rupture. Melatonin may diminish catecholamine activity. We hypothesized that melatonin mitigates the acute procoagulant stress response and that this effect is accompanied by a decrease in the stress‐induced catecholamine surge. Forty‐five healthy young men received a single oral dose of either 3 mg melatonin (n = 24) or placebo medication (n = 21). One hour thereafter, they underwent a standardized short‐term psychosocial stressor. Plasma levels of clotting factor VII activity (FVII:C), FVIII:C, fibrinogen, D‐dimer, and catecholamines were measured at rest, immediately after stress, and 20 min and 60 min post‐stress. The integrated change in D‐dimer levels from rest to 60 min post‐stress differed between medication groups controlling for demographic and metabolic factors (P = 0.047,  = 0.195). Compared with the melatonin group, the placebo group showed a greater increase in absolute D‐dimer levels from rest to immediately post‐stress (P = 0.13;  = 0.060) and significant recovery of D‐dimer levels from immediately post‐stress to 60 min thereafter (P = 0.007;  = 0.174). Stress‐induced changes in FVII:C, FVIII:C, fibrinogen, and catecholamines did not significantly differ between groups. Oral melatonin attenuated the stress‐induced elevation in the sensitive coagulation activation marker D‐dimer without affecting catecholamine activity. The finding provides preliminary support for a protective effect of melatonin in reducing the atherothrombotic risk with acute mental stress.
Immediate Functional Loading of Single‐Tooth TIO2 Grit‐Blasted Implant Restorations: A Controlled Prospective Study in a Porcine Model. Part I: Clinical Outcome
Authors: Bousdras Vasilios A. , Sindet‐Pedersen Steen , Cunningham James L. , Blunn Gordon , Petrie Aviva , Naert Ignace E. , Jaecques Siegfried , Goodship Allen E.
Published: November 2007

Background:  Although favorable integration occurs with immediately loaded implants, the relationship between implant outcome, levels of occlusion, and diet requires optimization.

Purpose:  Pertubating load on single implant restorations immediately after placement by a hard food diet will increase the strains at the bone‐implant interface, increasing the risk for failure.

Materials and Methods:  Forty‐eight implants replaced the first and third mandibular premolars in 12 pigs, allocated into two groups based on soft‐ and hard‐diet feeding. Cylindrical and tapered implants replaced the first and third premolars, respectively. Each animal received at random four different masticatory loading conditions (group 1 control]: implant with either a cover screw or a healing abutment, and group 2 test]: implant with a crown either with or without occlusal contacts).

Results:  Thirteen implants out of 44 failed in 11 animals (one with a cover screw, one with a healing abutment, three with nonocclusal, and eight with occlusal restorations). The failure rate of restored implants (either in occlusion or not) was significantly higher in the third premolar sites (p=.007), although diet had no significant effect (p=.421).

Conclusions:  While diet had no effect on the failure pattern of immediately loaded single implants, the position and type of load under the masticatory mode were significant. Immediately loaded implants both in and out of occlusion were less successful than the controls, and this is probably attributed to detrimental strain induced on the bone‐implant interface.
A 4‐Year Prospective Clinical and Radiological Study of Maxillary Dental Implants Supporting Single‐Tooth Crowns Using Early and Delayed Loading Protocols
Authors: Turkyilmaz Ilser , Avci Mehmet , Kuran Serkan , Ozbek Esma Nida
Published: November 2007

Background:  Recent studies have showed that immediate/early loading of dental implants is a clinically feasible concept with results similar to those for standard two‐stage procedures, especially in the mandible. However, there are only a few studies regarding the immediate/early loading of maxillary implants supporting single‐tooth crowns.

Purpose:  The aim of this study was to compare the clinical and radiological outcomes of early‐ and delayed‐loaded dental implants supporting single‐tooth crowns in the maxilla.

Materials and Methods:  Twenty‐nine patients were consecutively treated between 2000 and 2002 with 59 Brånemark System MK III TiUnite implants (Nobel Biocare AB, Göteborg, Sweden) in the maxilla. Two groups were formed according to the loading protocols. In the test group, definitive implant‐supported single crowns were delivered to 19 patients 6 weeks after the implant placement. In the control group, definitive implant‐supported single crowns were delivered to 10 patients 6 months after the implant placement. Clinical and radiographic parameters were recorded at baseline, 1 to 4 years. Implant stability measurements have only been performed at 4‐year follow‐up recall.

Results:  Overall, three implants were lost during the study period. Two implants were lost in the test group including 36 implants, which indicated a survival rate of 94.4%. One of the lost implants was replaced and then osseointegrated successfully. One implant was lost in the control group during the healing period, which indicated a survival rate of 95.7%. The average marginal bone loss was 1.11 mm for 56 implants after 4 years. There were no significant differences in marginal bone levels, insertion torque, and resonance frequency values between the two groups.

Conclusion:  The results of this study indicate that 6 weeks of early loading period for TiUnite‐surface titanium implants in the maxilla is reliable and predictable for this patient population and may offer an alternative to the standard loading protocol.
The Establishment of a Protocol for the Total Rehabilitation of Atrophic Maxillae Employing Four Zygomatic Fixtures in an Immediate Loading System – A 30‐Month Clinical and Radiographic Follow‐Up
Authors: Duarte Luis Rogério , Filho Hugo Nary , Francischone Carlos Eduardo , Peredo Luiz Guillermo , Brånemark Per‐Ingvar
Published: November 2007

Background:  The existing approaches to the treatment of the atrophic maxilla are difficult and involve an element of risk.

Purpose:  The aim of the present study was to establish a new surgical/prosthetic protocol for the treatment of extremely atrophic maxillae using four zygomatic implants (ZIs) in an immediate loading system.

Materials and Methods:  Twelve patients were treated with the surgical placement of 48 ZIs, and the totally edentulous maxillae were rehabilitated with protocol‐type maxillary prostheses rigidly fixed to the ZIs in an immediate loading system. Follow‐up was conducted at 6 months and again at 30 months.

Results:  Of the 48 ZIs inserted, one implant failed to achieve osseointegration. The prosthetic components fitted well and no sinus pathology was detected in any of the patients.

Conclusion:  The surgical/prosthetic protocol showed that it was possible to insert four ZIs in an immediate loading system and achieve stability for up to 30 months.
Effect of Dental Implant Cross‐Sectional Design on Cortical Bone Structure Using Finite Element Analysis
Authors: Abu‐Hammad Osama , Khraisat Ameen , Dar‐Odeh Najla , El‐Maaytah Mohammed
Published: November 2007

Purpose:  This finite element analysis investigation evaluated the effect of different implant cross‐sectional designs on bone stress levels under different loading patterns.

Materials and Methods:  Finite element analysis program was used to construct four different three‐dimensional models describing 4 × 10‐mm implants in blocks of cortical and trabecular bone. A 5‐mm‐long abutment was modeled above each implant. The implant in model 1 was unthreaded, while in model 2 the implant was circularly threaded. The third implant in model 3 had the cross‐sectional shape as a 16‐sided star‐shaped design. The implant in model 4 was constructed unthreaded, with a diameter of 4.5 mm. Vertical and horizontal loads of 100 N each were applied on the top middle node of each implant assembly. All nodes at the bottom surface of the bone models were restrained.

Results:  By comparing models 1, 2, and 3, the lowest bone stress values under vertical and horizontal forces were observed around the unthreaded implant in model 1 (8.92 and 94.52 MPa, respectively). The highest stress value under vertical loading was shown around the threaded implant in model 2 (10.07 MPa), whereas the highest stress value under horizontal loading was observed around the star‐shaped implant in model 3 (108.40 MPa). Model 4, with a wider unthreaded design, had stress values under vertical and horizontal loading of 7.32 and 71.35 MPa, respectively.

Conclusions:  It was concluded that the unthreaded implant design produced the least bone stress. An increase in implant diameter could produce marked reduction in stress value in the bone around the neck of the implant.
Characterization of the Surface Properties of Commercially Available Dental Implants Using Scanning Electron Microscopy, Focused Ion Beam, and High‐Resolution Transmission Electron Microscopy
Authors: Jarmar Tobias , Palmquist Anders , Brånemark Rickard , Hermansson Leif , Engqvist Håkån , Thomsen Peter
Published: November 2007

Background:  Since osseointegration of the respective implant is claimed by all manufacturing companies, it is obvious that not just one specific surface profile including the chemistry controls bone apposition.

Purpose:  The purpose was to identify and separate out a particular set of surface features of the implant surfaces that can contribute as factors in the osseointegration process.

Material and Methods:  The surface properties of several commercially available dental implants were extensively studied using profilometry, scanning electron microscopy, and transmission electron microscopy. Ultrathin sections prepared with focused ion beam microscopy (FIB) provided microstructural and chemical data which have not previously been communicated. The implants were the Nobel Biocare TiUnite® (Nobel Biocare AB, Göteborg, Sweden), Nobel Biocare Steri‐Oss HA‐coated (Nobel Biocare AB, Yorba Linda, CA, USA), Astra‐Tech OsseoSpeed™ (Astra Tech AB, Mölndal, Sweden), Straumann SLA® (Straumann AG, Waldenburg, Switzerland), and the Brånemark Integration Original Fixture implant (Brånemark Integration, Göteborg, Sweden).

Results:  It was found that their surface properties had differences. The surfaces were covered with crystalline TiO2 (both anatase and rutile), amorphous titanium oxide, phosphorus doped amorphous titanium oxide, fluorine, titanium hydride, and hydroxyapatite, respectively.

Conclusion:  This indicates that the provision of osseointegration is not exclusively linked to a particular set of surface features if the implant surface character is a major factor in that process. The studied methodology provides an effective tool to also analyze the interface between implant and surrounding bone. This would be a natural next step in understanding the ultrastructure of the interface between bone and implants.
Malignant Tumors of the Maxilla: Virtual Planning and Real‐Time Rehabilitation with Custom‐Made R‐zygoma Fixtures and Carbon–Graphite Fiber‐Reinforced Polymer Prosthesis
Authors: Ekstrand Karl , Hirsch Jan‐M.
Published: November 2007

Background: Oral cancer is a mutilating disease. Because of the expanding application of computer technology in medicine, new methods are constantly evolving. This project leads into a new technology in maxillofacial reconstructive therapy using a redesigned zygoma fixture.

Purpose: Previous development experiences showed that the procedure was time‐consuming and painful for the patients. Frequent episodes of sedation or general anesthetics were required and the rehabilitation is costly. The aim of our new treatment goal was to allow the patients to wake up after tumor surgery with a functional rehabilitation in place.

Materials and Methods: Stereolithographic models were introduced to produce a model from the three‐dimensional computed tomography (CT). A guide with the proposed resection was fabricated, and the real‐time maxillectomy was performed. From the postoperative CT, a second stereolithographic model was manufactured and in addition, a stent for the optimal position of the implants. Customized zygoma implants were installed (R‐zygoma, Integration AB, Göteborg, Sweden). A fixed construction was fabricated by using a new material based on poly(methylacrylate) reinforced with carbon/graphite fibers and attached to the implants. On the same master cast, a separate obturator was fabricated in permanent soft silicon.

Results: The result of this project showed that it was possible to create a virtual plan preoperatively to apply during surgery in order for the patient to wake up functionally rehabilitated.

Conclusion: From a quality‐of‐life perspective, it is an advantage to be rehabilitated fast. By using new computer technology, pain and discomfort are less and the total rehabilitation is faster, which in turn reduces days in hospital and thereby total costs.
A Finite Element Analysis of Stress Distribution in Bone Tissue Surrounding Uncoupled or Splinted Dental Implants
Authors: Bergkvist Göran , Simonsson Kjell , Rydberg Kristofer , Johansson Fredrik , Dérand Tore
Published: November 2007

Background: Several studies on one‐stage surgery in the treatment of the edentulous maxilla with implant‐supported fixed prostheses have reported problems with removable provisional prostheses, which can load the implants in an uncontrollable manner during healing, and jeopardize healing. Immediate splinting of the implants with a fixed provisional prosthesis has been proposed to protect the bone‐implant interface.

Purpose: This study used the finite element method (FEM) to simulate stresses induced in bone tissue surrounding uncoupled and splinted implants in the maxilla because of bite force loading, and to determine whether the differences in these stress levels are related to differences in observed bone losses associated with the two healing methods.

Materials and Methods: Stress levels in the maxilla were studied using the FEM program TRINITAS (Institute of Technology, Linköping University, Linköping, Sweden) in which all phases – preprocessing/modeling, equation solving, and postprocessing/evaluation – were simulated.

Results: Stress levels in bone tissue surrounding splinted implants were markedly lower than stress levels surrounding uncoupled implants by a factor of nearly 9.

Conclusion: From a mechanical viewpoint, FEM simulation supports the hypothesis that splinting reduces damage evolution in bone tissue, which agrees with clinical observations.
Rehabilitation of Edentulous Mandibles by Means of Five TiUnite™ Implants After One‐Stage Surgery: A 1‐Year Retrospective Study of 90 Patients
Authors: Friberg Bertil , Jemt Torsten
Published: November 2007

Background: Recently, the present team reported the 1‐year data of one‐stage surgery and mainly early loading performed in edentulous mandibles using 750 turned Brånemark System® implants in 152 patients.

Purpose: The aim of the present investigation was to retrospectively evaluate the 1‐year results of the same treatment technique, using Brånemark System implants with an oxidized surface (TiUnite™, Nobel Biocare AB, Göteborg, Sweden). The outcome was compared with that of the former study (control) on turned implants.

Materials and Methods: The present study involved 90 individuals with 450 TiUnite implants of mainly the Brånemark System Mark III design, placed in edentulous mandibles and using one‐stage surgery. The prosthetic procedure was commenced as a mean 8 days after the surgical intervention. Intraoral radiographs were obtained at prosthesis insertion and at the 1‐year annual checkup. Failure rates of test and control groups were compared by means of the chi‐square test.

Results: No implants were found to be mobile up to and including the first annual checkup, resulting in an implant cumulative survival rate (CSR) of 100%. The corresponding CSR for the control group was 97.5%, and this difference in implant survival was statistically significant when analyzed with the chi‐square test (p < .001). A statistically significant difference was also demonstrated (p < .01) when conducting the same statistical analysis on the patient level. The mean marginal bone resorption during the first year of function was 0.49 mm (SD 0.56), and the corresponding figures for the control study were 0.39 mm (SD 0.46). The central TiUnite implant, that is, the one placed in or in close relation to the symphyseal region showed significantly more bone loss (p < .05) than the corresponding central turned implant of the control study. Distally positioned test implants demonstrated less marginal bone loss than the corresponding central one.

Conclusions: The outcome of 450 TiUnite implants placed in 90 patients with edentulous mandibles, of which 380 implants in 76 patients were followed for 1 year, showed an implant CSR of 100%. The figure was significantly different from the control study result of 97.5% on turned surface implants. The levels of marginal bone were close to identical for test and control implants at the 1‐year checkup.
Enhanced Initial Cell Responses to Chemically Modified Anodized Titanium
Authors: Jimbo Ryo , Sawase Takashi , Baba Koumei , Kurogi Tadafumi , Shibata Yasuaki , Atsuta Mitsuru
Published: November 2007

Background: Previously, we reported that anodized porous titanium implants have photocatalytic hydrophilicity. However, this effect was not always sufficient for the significant improvement of bone apposition.

Purpose: The purpose of this study was to improve the photocatalytic properties of porous titanium implants by the fluoride modification of the anodized titanium dioxide (TiO2), and to investigate the initial cell response to it.

Materials and Methods: The ideal concentration of ammonium hydrogen fluoride (NH4F‐HF2) used in this study was determined by a static water contact angle assay. The ideal concentration of NH4F‐HF2 was 0.175%, and experimental disks were treated with this concentration. A pluripotent mesenchymal cell line, C2C12, was cultured on the disks in order to investigate cell attachment, morphology, and proliferation.

Results: Cell attachment after 30 minutes of culturing was significantly higher for the ultraviolet‐irradiated, fluoride‐modified anodized TiO2 (p < .05), and the simultaneous scanning electron microscope observation showed a rather flattened and extended cell morphology. The proliferation rate after 24 hours was also significantly higher for the fluoride‐modified anodized TiO2.

Conclusion: Fluoride chemical modification enhances the hydrophilic property of the anodized TiO2 and improves the initial cell response to it.
A New Technique for Reconstruction of the Atrophied Narrow Alveolar Crest in the Maxilla Using Morselized Impacted Bone Allograft and Later Placement of Dental Implants
Authors: Holmquist Per , Dasmah Amir , Sennerby Lars , Hallman Mats
Published: November 2007

Background: In cases when the alveolar crest is too narrow to host an implant, lateral augmentation is required. The use of autogenous bone blocks harvested from the iliac crest is often demanded. One disadvantage is the associated patient morbidity.

Purpose: The purpose of this study was to clinically and histologically evaluate the use of morselized impacted bone allograft, a novel technique for reconstruction of the narrow alveolar crest.

Materials and Methods: Two patients with completely edentulous maxillae and one partially edentulous, with a mean age of 77 years (range 76–79 years) were included in the study. The alveolar crest width was <3 mm without possibility to place any implant. Bone grafts were taken from a bone bank in Gävle Hospital. Bone from the neck of femur heads was milled to produce bone chips. The milled bone was partially defatted by rinsing in 37°C saline solution. After compression of the graft pieces with a size of 15 mm (height), 30 mm (length), and 6 mm (width), they were then fit to adapt to the buccal surface of the atrophied alveolar crest. One piece was placed to the right and one to the left side of the midline. On both sides fibrin glue was used (Tisseel®, Baxter AG, Vienna, Austria) to stabilize the graft.

After 6 months of graft healing, dental implants were placed, simultaneously biopsies were harvested and in one patient two oxidized microimplants were placed. At the time of abutment connection, microimplants were retrieved with surrounding bone for histology. Fixed screw‐retained bridges were fabricated in mean of 7 months after implant surgery. Radiographs were taken before and after implant surgery and after 1 year of loading.

Results: Sixteen implants with an oxidized surface were placed (TiUnite®, Nobel Biocare AB, Göteborg, Sweden). After 1 year of functional loading, all implants were clinically stable. The marginal bone loss was 1.4 mm (SD 0.3) after 1 year of loading. The histological examination showed resorption and subsequent bone formation on the allograft particles. There were no signs of inflammatory cell infiltration in conjunction with the allograft. The two microimplants showed bone formation directly on the implant surface.

Conclusions: This study shows that morselized impacted bone allograft can be used to increase the width of the atrophied narrow alveolar crest as a good alternative to autogenous bone grafts in elderly patients. The histological examination of biopsies revealed a normal incorporation process and no signs of an immunological reaction. Further studies with larger samples are of important to be able to conclude if equal results can be obtained using morselized impacted bone allograft as for autogenous bone graft.
Skills Diagnosis Using IRT‐Based Latent Class Models
Authors: Roussos Louis A. , Templin Jonathan L. , Henson Robert A.
Published: November 2007

This article describes a latent trait approach to skills diagnosis based on a particular variety of latent class models that employ item response functions (IRFs) as in typical item response theory (IRT) models. To enable and encourage comparisons with other approaches, this description is provided in terms of the main components of any psychometric approach: the ability model and the IRF structure; review of research on estimation, model checking, reliability, validity, equating, and scoring; and a brief review of real data applications. In this manner the article demonstrates that this approach to skills diagnosis has built a strong initial foundation of research and resources available to potential users. The outlook for future research and applications is discussed with special emphasis on a call for pilot studies and concomitant increased validity research.
Modeling Diagnostic Assessments with Bayesian Networks
Authors: Almond Russell G. , DiBello Louis V. , Moulder Brad , Zapata‐Rivera Juan‐Diego
Published: November 2007

This paper defines Bayesian network models and examines their applications to IRT‐based cognitive diagnostic modeling. These models are especially suited to building inference engines designed to be synchronous with the finer grained student models that arise in skills diagnostic assessment. Aspects of the theory and use of Bayesian network models are reviewed, as they affect applications to diagnostic assessment. The paper discusses how Bayesian network models are set up with expert information, improved and calibrated from data, and deployed as evidence‐based inference engines. Aimed at a general educational measurement audience, the paper illustrates the flexibility and capabilities of Bayesian networks through a series of concrete examples, and without extensive technical detail. Examples are provided of proficiency spaces with direct dependencies among proficiency nodes, and of customized evidence models for complex tasks. This paper is intended to motivate educational measurement practitioners to learn more about Bayesian networks from the research literature, to acquire readily available Bayesian network software, to perform studies with real and simulated data sets, and to look for opportunities in educational settings that may benefit from diagnostic assessment fueled by Bayesian network modeling.
ANTIOXIDANT EFFECT AND DNA PROTECTIVE EFFECT OF VARIOUS ENZYMATIC EXTRACTS FROM PERILLA FRUTESCENS VAR. CRISPA
Authors: KIM EUN‐KYUNG , LEE SEUNG‐JAE , JEON YOU‐JIN , AHN CHANG‐BUM , SONG MIN DONG , PARK TAE‐KYU , MOON SANG‐HO , JEON BYONG‐TAE , SHAHIDI FEREIDOON , PARK PYO‐JAM
Published: November 2007

The antioxidant activity of enzymatic extracts from Perilla frutescens var. crispa was evaluated using 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical, hydroxyl radical and alkyl radical‐scavenging activity by employing an electron spin resonance methodology. P. frutescens var. crispa was enzymatically hydrolyzed by eight carbohydrases (Dextrozyme, AMG, Promozyme, Maltogenase, Termamyl, Viscozyme, Celluclast, BAN [Novo Co., Novozyme Nordisk, Bagsvaerd, Denmark]) and nine proteases (Flavourzyme, Neutrase, Protamex, Alcalase, PP‐trypsin [trypsin from porcine pancreas; Novo Co.], papain, pepsin, α‐chymotrypsin, BP‐trypsin [trypsin from bovine pancreas; Sigma Chemical Co., St. Louis, MO]). The DPPH radical‐scavenging activities of Dextrozyme and Neutrase extracts from P. frutescens var. crispa were the highest and the IC50 values were 60.12 and 112.81 µg/mL, respectively. All enzymatic extracts of P. frutescens var. crispa scavenged hydroxyl radical and the scavenging activity increased in a dose‐dependent manner; the IC50 values of Viscozyme and BP‐trypsin, which showed the highest activity, were 0.78 and 0.26 mg/mL, respectively. In addition, the Termamyl and Protamex extracts of P. frutescens var. crispa showed the highest alkyl radical‐scavenging activities, and the IC50 values were 248.13 and 415.23 µg/mL, respectively. The Viscozyme and BP‐trypsin extracts from P. frutescens var. crispa showed protective effect against H2O2‐induced DNA damage. These results indicate that enzymatic extracts of P. frutescens var. crispa possess antioxidant activity.

PRACTICAL APPLICATIONS

Perilla frutescens var. crispa could be used to produce protein and carbohydrate extracts with antioxidative activeity. Many industrial commercial enzymes, such as Promozyme, Celluclast 1.5 L FG, Maltogenase L, Viscozyme L, Termamyl SC, Dextrozyme E, AMG 300 L, Protamex, Flavourzyme 500 MG, Neutrase 0.8 L, Puncreatic Trypsin and Alcalase 2.4 L, could also be used to attain the extracts processing the high antioxidative activity. The extracts can be used as natural antioxidants.
EFFECTS OF HIGH‐CHOLESTEROL DIET AND ANTIOXIDANT VITAMINS COMBINATION ON OXIDANT/ANTIOXIDANT STATUS IN HEART, KIDNEY, LIVER AND TESTIS TISSUES FROM RATS
Authors: DEVRİM ERDİNÇ , ÖZBEK HANEFİ , DURAK İLKER
Published: November 2007

Possible effects of a high‐cholesterol diet on the oxidant/antioxidant status in various tissues from rats and the effects of the combination of vitamins C and E on these parameters and on hypercholesterolemia were investigated. Twenty‐four Sprague‐Dawley type rats were randomly divided into three groups. The control group (group 1) was fed on a rat pellet diet. The study groups (groups 2 and 3) were fed on a high‐cholesterol diet for 3 months. Rats in group 3 were supplemented with vitamins C (100 mg/kg intraperitoneally ) and E (60 mg/kg intramuscularly ) three times a week throughout the study. At the end of the study period, all animals were sacrificed and their heart, kidney, liver and testis surgically removed to measure oxidant and antioxidant parameters. Blood samples were also obtained from the animals. We observed that serum total cholesterol levels significantly increased in the study groups after the study period. The increase in the blood cholesterol level in group 3 was, however, significantly lower than that in group 2. As to the oxidant–antioxidant parameters, there were different results among the tissues. In conclusion, our results suggest that high serum cholesterol level does not lead to oxidation reactions in the early phase of hypercholesterolemia, and antioxidant vitamins supplementation increases antioxidant potential values of the tissues and decreases the blood total cholesterol level in the cholesterol‐supplemented animals.

PRACTICAL APPLICATIONS

It is clearly known that hypercholesterolemia is an important health problem throughout the world. The results of the present study indicate that antioxidant vitamins (vitamins C and E) may be useful in the prevention of hypercholesterolemia
PRODUCTION OF REFINED CAROTENE‐RICH PALM OIL FROM PALM MESOCARP (ELAEIS GUINEENSIS) USING SUPERCRITICAL CARBON DIOXIDE
Authors: LAU HARRISON LIK NANG , CHOO YUEN MAY , MA AH NGAN , CHUAH CHENG HOCK
Published: November 2007

Simultaneous extraction, degumming and deacidification of palm oil directly from palm mesocarp using supercritical carbon dioxide (SC‐CO2) were carried out. The temperatures and pressures used were 40–80C and 18–30 MPa, respectively. The degummed and deacidified palm oil produced from the process meets the specifications of refined, bleached and deodorized palm oil of Malaysian standard, with added value in its carotene content . The recovery of the refined palm oil was 52.8–74.0% based on the total hexane extractable material. Other palm minor components such as vitamin E, phytosterols and squalene were preserved in the refined SC‐CO2‐extracted carotene‐rich palm oil. The solubility of triacylglycerols (TGs), distribution coefficient of free fatty acids (FFAs) and the separation factor of FFAs and TGs of palm oil in SC‐CO2 are discussed.

PRACTICAL APPLICATIONS

The study provides an alternative processing method for palm oil extraction and refining industries. The same principles could be applied to oilseed processing such as soybean and rapeseed oils. The separation factors of free fatty acids (FFAs)/triacylglycerols and the distribution coefficient of FFAs are useful data for process modeling. The extractability and extraction patterns of palm minor components in the mesocarp provide an insight for the recovery of these valuable functional components from palm oil.