Effect of Implant Design on Initial Stability of Tapered Implants

2009 ◽  
Vol 35 (3) ◽  
pp. 130-135 ◽  
Author(s):  
Linus Chong ◽  
Ahmed Khocht ◽  
Jon B. Suzuki ◽  
John Gaughan
Keyword(s):  
Repeated Measures ◽  
Primary Stability ◽  
Analysis Of Covariance ◽  
Implant Design ◽  
Insertion Depth ◽  
Weak Association ◽  
Initial Stability ◽  
Repeated Measures Analysis ◽  
Different Depths ◽  
Strength Of Association

Abstract Implant design is one of the parameters for achieving successful primary stability. This study aims to examine the effect of a self-tapping blades implant design on initial stability in tapered implants. Polyurethane blocks of different densities were used to simulate different bone densities. The two different implant designs included one with self-tapping blades and one without self-tapping blades. Implants were placed at 3 different depths: apical third, middle third, and fully inserted at 3 different densities of polyurethane blocks. A resonance frequency (RF) analyzer was then used to measure stability of the implants. Repeated-measures analysis of variance was used to examine the effect of implant design, insertion depth, and block density on RF. Analysis of covariance was used to examine the strength of association between RF and the aforementioned factors. In both medium-density (P = .017) and high-density (P = .002) blocks, fully inserted non-self-tapping implants showed higher initial stability than self-tapping implants. No differences were noted between the 2 implant designs that were not fully inserted. The highest strength of association was with insertion depth (standardized beta [std β] = −0.60, P = .0001), followed by block density (std β = −0.15, P = .0002). Implant design showed a weak association (std β = −0.07, P = .09). In conclusion, fully inserted implants without self-tapping blades have higher initial stability than implants with self-tapping blades. However, the association strength between implant design and initial stability is less relevant than other factors, such as insertion depth and block density. Thus, if bone quality and quantity are optimal, they may compensate for design inadequacy.

Effects of Vaporized Perfluorocarbon on Pulmonary Blood Flow and Ventilation/Perfusion Distribution in a Model of Acute Respiratory Distress Syndrome

2001 ◽  
Vol 95 (6) ◽  
pp. 1414-1421 ◽  
Author(s):  
Matthias Hübler ◽  
Jennifer E. Souders ◽  
Erin D. Shade ◽  
Nayak L. Polissar ◽  
Carmel Schimmel ◽  
...  
Keyword(s):  
Blood Flow ◽  
Oleic Acid ◽  
Gas Exchange ◽  
Lung Injury ◽  
Repeated Measures ◽  
Pulmonary Blood Flow ◽  
Analysis Of Covariance ◽  
Inert Gas ◽  
Low Flow ◽  
Repeated Measures Analysis

Background Perfluorocarbon (PFC) liquids are known to improve gas exchange and pulmonary function in various models of acute respiratory failure. Vaporization has been recently reported as a new method of delivering PFC to the lung. Our aim was to study the effect of PFC vapor on the ventilation/perfusion (VA/Q) matching and relative pulmonary blood flow (Qrel) distribution. Methods In nine sheep, lung injury was induced using oleic acid. Four sheep were treated with vaporized perfluorohexane (PFX) for 30 min, whereas the remaining sheep served as control animals. Vaporization was achieved using a modified isoflurane vaporizer. The animals were studied for 90 min after vaporization. VA/Q distributions were estimated using the multiple inert gas elimination technique. Change in Qrel distribution was assessed using fluorescent-labeled microspheres. Results Treatment with PFX vapor improved oxygenation significantly and led to significantly lower shunt values (P < 0.05, repeated-measures analysis of covariance). Analysis of the multiple inert gas elimination technique data showed that animals treated with PFX vapor demonstrated a higher VA/Q heterogeneity than the control animals (P < 0.05, repeated-measures analysis of covariance). Microsphere data showed a redistribution of Qrel attributable to oleic acid injury. Qrel shifted from areas that were initially high-flow to areas that were initially low-flow, with no difference in redistribution between the groups. After established injury, Qrel was redistributed to the nondependent lung areas in control animals, whereas Qrel distribution did not change in treatment animals. Conclusion In oleic acid lung injury, treatment with PFX vapor improves gas exchange by increasing VA/Q heterogeneity in the whole lung without a significant change in gravitational gradient.

Aerobic Fitness and Emotional Arousal: A Critical Attempt at Replication

1981 ◽  
Vol 48 (3) ◽  
pp. 911-918 ◽  
Author(s):  
Jeffrey D. Zimmerman ◽  
Margaret Fulton
Keyword(s):  
Trait Anxiety ◽  
Repeated Measures ◽  
Psychosocial Stress ◽  
Electrodermal Activity ◽  
Heart Rate Recovery ◽  
Analysis Of Covariance ◽  
State Trait Anxiety Inventory ◽  
Repeated Measures Analysis ◽  
Two Indices ◽  
Statistical Results

This study was an attempt to replicate the findings of earlier research in which conclusions were based on a questionable interpretation of statistical results. A 2 × 2 repeated-measures analysis of covariance did not confirm, as had been previously reported, greater heart-rate recovery for 20 aerobically fit subjects as opposed to 20 unfit subjects following psychosocial stress. Two indices of electrodermal activity and State-Trait Anxiety Inventory responses also were utilized. Only the comparison between groups for Trait Anxiety was statistically significant.

Female sex hormones in men with migraine

Neurology ◽  
2018 ◽  
Vol 91 (4) ◽  
pp. e374-e381 ◽  
Author(s):  
Willebrordus P.J. van Oosterhout ◽  
Guus G. Schoonman ◽  
Erik W. van Zwet ◽  
Olaf M. Dekkers ◽  
Gisela M. Terwindt ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Free Testosterone ◽  
Analysis Of Covariance ◽  
Androgen Deficiency ◽  
Female Sex Hormones ◽  
Repeated Measures Analysis ◽  
17Β Estradiol ◽  
Migraine Group ◽  
Aging Males Symptoms

ObjectiveTo assess the role of estradiol and testosterone in men with migraine.MethodsWe measured 17β-estradiol (E2) and calculated free testosterone (Tf) in serum of 17 medication-free men with migraine and 22 men without migraine group-matched for age and body mass index (BMI), targeted at 20 to 28 kg/m2. Blood was sampled on a single, for migraineurs interictal, day at 9 am, 12 pm, 3 pm, and 6 pm. Migraineurs were subsequently measured 3 to 4 times daily until an attack occurred. Clinical androgen deficiency was assessed with the Androgen Deficiency of Ageing Men questionnaire and the Aging Males' Symptoms (AMS) scale. We analyzed interictal data (mean ± standard error) with repeated-measures analysis of covariance and longitudinal data by generalized estimated equations models.ResultsCompared to controls, men with migraine had a lower interictal Tf/E2 ratio (3.9 ± 0.4 vs 5.0 ± 0.3, p = 0.03) due to higher E2 (96.8 ± 6.1 vs 69.1 ± 5.6 pmol/L, p = 0.001) and similar Tf (357.5 ± 21.4 vs 332.6 ± 18.7 pmol/L, p = 0.35) levels. Preictal Tf levels were increased in men with migraine reporting premonitory symptoms (p = 0.03). Men with migraine more frequently reported symptoms of androgen deficiency (11 of 18 [61.1%] vs 6 of 22 [27.3%], p = 0.031), which were also more frequently severe (p = 0.006); their age- and BMI-adjusted AMS scores were higher (27.0 ± 1.2 vs 21.0 ± 1.0, p = 0.002).ConclusionsIn this study, nonobese men with migraine exhibited increased levels of the sex hormone estradiol and showed clinical evidence of relative androgen deficiency. The role of estradiol in modulating migraine susceptibility and activity in men deserves further investigations.

scholarly journals Influence of Eating Schedule on the Postprandial Response: Gender Differences

Nutrients ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 401 ◽  
Author(s):  
Marcela Masihy ◽  
Hugo Monrroy ◽  
Giulio Borghi ◽  
Teodora Pribic ◽  
Carmen Galan ◽  
...  
Keyword(s):  
Gender Differences ◽  
Repeated Measures ◽  
Physiological Responses ◽  
Well Being ◽  
Sensory Experience ◽  
Analysis Of Covariance ◽  
Repeated Measures Analysis ◽  
Postprandial Response ◽  
And Gender ◽  
Schedule Effect

Ingestion of a meal induces conscious sensations depending of the characteristics of the meal and the predisposition of the eater. We hypothesized that the eating schedule plays a conditioning role, specifically, that an extemporaneous meal is less rewarding than when eaten at the habitual schedule. We conducted a randomized parallel trial in 10 women and 10 men comparing the responses to a consistent savoury lunch-type meal (stewed beans) eaten at the habitual afternoon schedule or at an unconventional time in the morning. Schedule and gender differences were analyzed by repeated measures analysis of covariance. In women, the sensory experience induced by the probe meal, particularly postprandial satisfaction, was weaker when eaten at an unconventional time for breakfast. Men were resilient to the schedule effect and experienced the same sensations regardless of the timing of ingestion; the effect of the eating schedule was significantly more pronounced in women for fullness (F(1,55) = 14.9; p < 0.001), digestive well-being (F(1,36.8) = 22.3; p < 0.001), mood (F(1,12.4) = 13.8; p < 0.001), and anxiety (F(1,11.9) = 10.9; p = 0.001). No differences in the physiological responses induced by the afternoon and morning meals were detected either in women or men. Our data indicate that women are more susceptible to changes in meal schedule than men.

Effect Of Early Caffeine Therapy On Weight Gain In Very Preterm Infants

2019 ◽  
Author(s):  
Srinivasan Mani ◽  
Fernanda Kupferman ◽  
Roger Kim
Keyword(s):  
Weight Gain ◽  
Preterm Infants ◽  
Premature Infants ◽  
Repeated Measures ◽  
Analysis Of Covariance ◽  
Very Preterm Infants ◽  
Very Preterm ◽  
Repeated Measures Analysis ◽  
Practical Impact ◽  
Poor Weight Gain

Abstract Background: Premature infants were observed to have poor weight gain for the first 3 weeks after initiating caffeine therapy. The practical impact of this adverse effect in the era of prophylactic (early) caffeine therapy in very preterm infants have not been analyzed well.Methods: A retrospective cohort study was conducted including preterm infants born at < 31 weeks gestation between June 2013 and June 2016. Infants were divided into 2 groups based on the timing of caffeine initiation: less than the 48 hours after birth (early) and 48 or more hours after birth (late). The outcome was weight in grams at the end of 3rd week of life. Independent t-test and repeated-measures analysis of covariance (ANCOVA) were used for analysis. Results: Thirty-nine (84.6%) out of 46 infants born < 31 weeks gestation with a birth weight < 1250 grams were included in the study. Of the 39 infants, 22 received early caffeine therapy and 17 received late caffeine therapy. On comparing the weight at 3 weeks of age between the two groups, the early caffeine group had a significantly better weight gain with a mean weight at 3 weeks being 1140 grams vs 985 grams (p=0.03). Conclusion: In very preterm infants, early caffeine therapy was associated with better weight gain in the first 3 weeks of life.

scholarly journals Oxytocin and Oxytocinase in the Obese and Nonobese Parturients during Induction and Augmentation of Labor

2019 ◽  
Vol 09 (02) ◽  
pp. e177-e184
Author(s):  
Annemaria De Tina ◽  
Jeremy Juang ◽  
Thomas F. McElrath ◽  
Jack D. Baty ◽  
Arvind Palanisamy
Keyword(s):  
Repeated Measures ◽  
Mixed Model ◽  
Group Versus ◽  
Preliminary Evidence ◽  
Analysis Of Covariance ◽  
Uterine Contractions ◽  
Time Interaction ◽  
Repeated Measures Analysis ◽  
Elective Induction ◽  
The Mean

Objective To investigate differences in oxytocin (OXT) biodistribution between nonobese and obese parturients during labor. Study Design Patients with body mass index (BMI) of either ≥ 18 ≤ 24.9 kg/m2 (“nonobese”) or ≥ 30 kg/m2 (“obese”) undergoing elective induction of labor were included (N = 25 each). Blood samples were collected at baseline (T0), and 20 minutes after maximal OXT augmentation or adequate uterine contractions (T1) for OXT and oxytocinase assays. A mixed-model repeated-measures analysis of variance was used to test for group versus time interaction and analysis of covariance to detect a difference in OXT level at T1. Data presented as mean ± standard deviation or median (interquartile range), with p < 0.05 considered significant. Results The mean BMIs (kg/m2) were 22.1 ± 1.6 and 35.9 ± 5.1 in the nonobese and obese groups, respectively. No differences were observed in either the duration of OXT infusion, total dose of OXT, or plasma OXT (pg/mL) either at T0 or T1. However, plasma oxytocinase (ng/mL) was significantly lower at T0 (1.41 [0.67, 3.51] vs. 0.40 [0.29, 1.12]; p = 0.03) in the obese group. Conclusion We provide preliminary evidence that the disposition of OXT may not be different between obese and nonobese women during labor.

Move to Read Pilot Program for Academically Struggling Students to Improve Sight Word Performance

2020 ◽  
pp. 1-5
Author(s):  
Weiyun Chen ◽  
Cynthia Bowers ◽  
Pamela Hodges Kulinna
Keyword(s):  
Pilot Study ◽  
Physical Education ◽  
Student Performance ◽  
Repeated Measures ◽  
Analysis Of Covariance ◽  
Group Differences ◽  
Struggling Students ◽  
Sight Word ◽  
Word Test ◽  
Repeated Measures Analysis

Purpose: To present a pilot study that uses experiential learning theory to understand the effect of a Move to Read (MTR) program on student performance on a sight word test. Methods: Two groups in a school were compared. The academic struggling students (n = 37) received MTR activities in the classroom and physical education, whereas the regular academic achieving group (n = 28) only had the MTR activities in physical education during the eight and a half months’ pilot study. Students were tested using the Dolch Sight Word test. Results: Analysis of covariance showed no group differences. Repeated-measures analysis of variance showed significant increases in the sight word test for the academically struggling group over time (F2 = 152.276, p < .001, ). Conclusions: The MTR program shows promise for improving sight word performance using movement.

scholarly journals Size of hippocampal pyramidal neurons in schizophrenia

2003 ◽  
Vol 183 (5) ◽  
pp. 414-417 ◽  
Author(s):  
J. R. Highley ◽  
M. A. Walker ◽  
B. McDonald ◽  
T. J. Crow ◽  
M. M. Esiri
Keyword(s):  
Repeated Measures ◽  
Pyramidal Neurons ◽  
Analysis Of Covariance ◽  
Hippocampal Pyramidal Neurons ◽  
Hippocampal Cell ◽  
Repeated Measures Analysis ◽  
Main Effect ◽  
Neuron Size ◽  
And Gender ◽  
Meta Analyses

BackgroundMeta-analyses of hippocampal size have indicated that this structure is smaller in schizophrenia. This could reflect a reduction in the size of constituent neurons or a reduced number of neurons.AimsTo measure the size of hippocampal pyramidal neurons in the brains of people with and without schizophrenia.MethodPyramidal neuron size in hippocampal subfields was estimated stereologically from sections taken at 5 mm intervals throughout the whole length of right and left hippocampi from the brains of 13 people with schizophrenia and 16 controls. Results were assessed using repeated-measures analysis of covariance looking for a main effect of diagnosis and gender, and interactions of these with side.ResultsWe were unable to detect significant differences related to diagnosis, gender or side for any hippocampal subfield for this series of cases.ConclusionsFor this series of brains, hippocampal cell size is unchanged in schizophrenia.

Music stimuli in mindfulness meditation: Comparison of musician and non-musician responses

2020 ◽  
pp. 030573562090133
Author(s):  
Eugenia Hernandez-Ruiz ◽  
Abbey L Dvorak ◽  
Kevin Weingarten
Keyword(s):  
Repeated Measures ◽  
Mindfulness Meditation ◽  
Mixed Effects ◽  
Analysis Of Covariance ◽  
Auditory Stimuli ◽  
Clinical Implications ◽  
Music Intervention ◽  
Group Status ◽  
Repeated Measures Design ◽  
Repeated Measures Analysis

The purpose of this study was to compare the effectiveness of and preference for different auditory stimuli on mindfulness meditation in musicians. A second purpose was to compare musician responses with non-musician responses from a previous study. A repeated-measures design exposed participants to four auditory stimuli of increased complexity. Participants ( N = 49) were undergraduate musicians with limited mindfulness experience. Data included absorption in music, mindfulness, and preference and usefulness of auditory stimuli. A repeated-measures analysis of covariance, with absorption of music as a covariate, found no significant differences between stimuli on mindfulness meditation according to musicians. Friedman’s analyses of variance indicated that musician rankings of usefulness and preference were significantly different among conditions. Both musicians and non-musicians ranked Melody and Harmony conditions as most preferred and most useful for mindfulness meditation. A mixed effects model with both groups indicated not only a significant effect of auditory stimuli on mindfulness but also interaction due to group status. A significant result was only obtained when the covariate was not considered. Absorption in music scores between groups was significantly higher for musicians than non-musicians. These outcomes support the hypothesis that absorption in music and music expertise may mediate the effect of a music intervention. Clinical implications are discussed.

scholarly journals Two Different Methods to Measure the Stability of Acetabular Implants: A Comparison Using Artificial Acetabular Models

Sensors ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 254
Author(s):  
Quentin Goossens ◽  
Leonard Cezar Pastrav ◽  
Michiel Mulier ◽  
Wim Desmet ◽  
Jos Vander Sloten ◽  
...  
Keyword(s):  
Surgical Techniques ◽  
Primary Stability ◽  
Test Methods ◽  
Implant Design ◽  
Implant Stability ◽  
Press Fit ◽  
Initial Stability ◽  
Custom Made ◽  
Golden Standard ◽  
Load To Failure

The total number of total hip arthroplasties is increasing every year, and approximately 10% of these surgeries are revisions. New implant design and surgical techniques are evolving quickly and demand accurate preclinical evaluation. The initial stability of cementless implants is one of the main concerns of these preclinical evaluations. A broad range of initial stability test methods is currently used, which can be categorized into two main groups: Load-to-failure tests and relative micromotion measurements. Measuring relative micromotion between implant and bone is recognized as the golden standard for implant stability testing as this micromotion is directly linked to the long-term fixation of cementless implants. However, specific custom-made set-ups are required to measure this micromotion, with the result that numerous studies opt to perform more straightforward load-to-failure tests. A custom-made micromotion test set-up for artificial acetabular bone models was developed and used to compare load-to-failure (implant push-out test) with micromotion and to assess the influence of bone material properties and press-fit on the implant stability. The results showed a high degree of correlation between micromotion and load-to-failure stability metrics, which indicates that load-to-failure stability tests can be an appropriate estimator of the primary stability of acetabular implants. Nevertheless, micromotions still apply as the golden standard and are preferred when high accuracy is necessary. Higher bone density resulted in an increase in implant stability. An increase of press-fit from 0.7 mm to 1.2 mm did not significantly increase implant stability.

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