scholarly journals The Distribution and Severity of Corrosion Damage at Eight Distinct Zones of Metallic Femoral Stem Implants

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 840 ◽  
Author(s):  
Roohollah Milimonfared ◽  
Reza Oskouei ◽  
Mark Taylor ◽  
Lucian Solomon
Keyword(s):  
Spatial Distribution ◽  
Hip Replacement ◽  
Logistic Regression Model ◽  
Statistical Significance ◽  
Femoral Stem ◽  
Corrosion Damage ◽  
Distal Region ◽  
Proximal Region ◽  
Visual Scoring ◽  
Ordinal Logistic Regression Model

Metallic taper junctions of modular total hip replacement implants are analysed for corrosion damage using visual scoring based on different granularity levels that span from analysing the taper holistically to dividing the taper into several distinct zones. This study aims to objectively explore the spatial distribution and the severity of corrosion damage onto the surface of metallic stem tapers. An ordinal logistic regression model was developed to find the odds of receiving a higher score at eight distinct zones of 137 retrieved stem tapers. A method to find the order of damage severity across the eight zones is introduced based on an overall test of statistical significance. The findings show that corrosion at the stem tapers occurred more commonly in the distal region in comparison with the proximal region. Also, the medial distal zone was found to possess the most severe corrosion damage among all the studied eight zones.

Visual assessment of 18F-FDG metabolic spatial distribution improves the differential diagnosis of indeterminate pulmonary nodules and masses with high FDG uptake

2020 ◽  
Author(s):  
Jie Lin ◽  
Ling Wang ◽  
Xiaowei Ji ◽  
Xiangwu Zheng ◽  
Kun Tang
Keyword(s):  
Spatial Distribution ◽  
Visual Analysis ◽  
Characteristic Curve ◽  
Pulmonary Nodules ◽  
Distal Region ◽  
Proximal Region ◽  
Benign Lesions ◽  
Fdg Uptake ◽  
Pet Ct ◽  
Malignant Lesions

Abstract Purpose The aim of this study was to evaluate the value of visual analysis of 18 F-fluorodeoxyglucose ( 18 F-FDG) metabolic spatial distribution (V-FMSD) in diagnosis of indeterminate pulmonary nodules and masses with high 18 F-FDG uptake. Methods A total of 301 patients with indeterminate pulmonary nodules or masses who undergone 18 F-FDG positron emission tomography/computed tomography (PET/ CT) imaging were studied retrospectively. The characteristics of 18 F-FDG metabolic spatial distribution (FMSD) of proximal and distal regions of the lesion were visually analyzed using a 5-point scoring system. The sensitivity, specificity, accuracy and area under receiver operating characteristic curve (AUC) were compared between V-FMSD and conventional PET/CT methods for diagnosis of hypermetabolic indeterminate pulmonary nodules and masses. Results The V-FMSD results showed that 180 (92.8%) malignant lesions’ scores were ≥ 3 and 78 (72.9%) benign lesions’ scores were ≤ 2. It indicated that the FMSD in the proximal region of malignant lesions was significantly higher than that of the distal region, and the FMSD in the proximal region of benign lesions was significantly lower than that of the distal region. The specificity of V-FMSD was 72.9%, which was obviously higher than the maximum standard uptake value (SUVmax) (0%, P < 0.001) and retention index (RI) (26.2%, P < 0.001). The AUC of V-FMSD was 0.886, which was significantly larger than SUVmax (0.626, P < 0.001), RI (0.670, P < 0.001) and PET/CT (0.788, P < 0.05). Conclusions The characteristics of FMSD between pulmonary benign and malignant lesions are different. V-FMSD can be taken as a novel auxiliary marker to improve the diagnostic performance for hypermetabolic indeterminate pulmonary nodules and masses.

scholarly journals Do galactic bars depend on environment?: an information theoretic analysis of Galaxy Zoo 2

2020 ◽  
Vol 501 (1) ◽  
pp. 994-1001
Author(s):  
Suman Sarkar ◽  
Biswajit Pandey ◽  
Snehasish Bhattacharjee
Keyword(s):  
Spatial Distribution ◽  
Mutual Information ◽  
Local Density ◽  
Statistical Significance ◽  
Distribution Functions ◽  
Cumulative Distribution ◽  
Host Galaxy ◽  
Data Sets ◽  
Data Set ◽  
Information Theoretic

ABSTRACT We use an information theoretic framework to analyse data from the Galaxy Zoo 2 project and study if there are any statistically significant correlations between the presence of bars in spiral galaxies and their environment. We measure the mutual information between the barredness of galaxies and their environments in a volume limited sample (Mr ≤ −21) and compare it with the same in data sets where (i) the bar/unbar classifications are randomized and (ii) the spatial distribution of galaxies are shuffled on different length scales. We assess the statistical significance of the differences in the mutual information using a t-test and find that both randomization of morphological classifications and shuffling of spatial distribution do not alter the mutual information in a statistically significant way. The non-zero mutual information between the barredness and environment arises due to the finite and discrete nature of the data set that can be entirely explained by mock Poisson distributions. We also separately compare the cumulative distribution functions of the barred and unbarred galaxies as a function of their local density. Using a Kolmogorov–Smirnov test, we find that the null hypothesis cannot be rejected even at $75{{\ \rm per\ cent}}$ confidence level. Our analysis indicates that environments do not play a significant role in the formation of a bar, which is largely determined by the internal processes of the host galaxy.

scholarly journals Severe stunting and its associated factors among children aged 6–59 months in Ethiopia; multilevel ordinal logistic regression model

2021 ◽  
Vol 47 (1) ◽  
Author(s):  
Amare Muche ◽  
Reta Dewau
Keyword(s):  
Logistic Regression ◽  
Odds Ratio ◽  
Associated Factors ◽  
Logistic Regression Model ◽  
Adjusted Odds Ratio ◽  
Wealth Index ◽  
Maternal Height ◽  
Severe Stunting ◽  
Mothers And Children ◽  
Ordinal Logistic Regression Model

Abstract Background In Ethiopia, stunting is the most common form of undernutriton. Identifying the determinants of severe stunting among children is crucial for public health interventions to improve child health. Therefore, this study aimed to identify the determinants of severe stunting among under-five children in Ethiopia. Methods A community-based cross-sectional study design was employed. A two stage stratified cluster sampling technique was used. A multilevel ordinal logistic regression model was fitted to identify independent determinants. Adjusted odds ratio (AOR) and median odds ratio (MOR) with its 95% confidence interval at p-value< 0.05 were used to declare statistical significance. Results The result of this study showed that about 18% of the children were severely stunted. Being male increased the severity of stunting in children by 26% adjusted odds ratio (AOR): 1.26 (95% CI: 1.09–1.46), compared to female sex; over-weight mothers increased the severity of stunting in their children AOR: 3.43 (95% CI: 2.21–5.33) compared to normal BMI mothers; and children from middle, poorer, and poorest wealth index households were 1.84 (95% CI:1.27–2.67), 2.13 (95% CI, CI:1.45–3.14) and 2.52 (95% CI,1.72–3.68). In contrast, severe stunting was reduced by 62% (AOR: 0.38, 95% CI: 0.20–0.74) and 48% (AOR = 0.52, 95% CI: 0.37–0.72) in children of educated mothers compared to children of uneducated mothers and children of underweight mothers compared with those children of normal BMI mothers respectively. For each one-unit increase in maternal height, there is a 5% significant reduction in the child’s odds of being severely stunted. After controlling for other factors, the effect of predictors on the likelihood of stunting in high risk clusters increased by a median odds ratio (MOR) of 1.83 (95% CI: 1.69–2.00). Conclusions The magnitude of severe childhood stunting was still high with regional variation in Ethiopia. Child age, sex, maternal height, age, education and household wealth index as well as administrative regions were significantly associated factors with severe stunting. Significant interventions shall be implemented at the individual, household and community levels in order to reduce the problem.

scholarly journals Intestinal Apolipoprotein A-IV Gene Transcription Is Controlled by Two Hormone-Responsive Elements: A Role for Hepatic Nuclear Factor-4 Isoforms

2005 ◽  
Vol 19 (9) ◽  
pp. 2320-2334 ◽  
Author(s):  
Amena Archer ◽  
Dominique Sauvaget ◽  
Valérie Chauffeton ◽  
Pierre-Etienne Bouchet ◽  
Jean Chambaz ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transgenic Mice ◽  
Distal Region ◽  
Proximal Region ◽  
Dominant Negative ◽  
Specific Expression ◽  
Nuclear Factors ◽  
Dominant Negative Form ◽  
Responsive Element ◽  
Hormone Responsive Element

Abstract In the small intestine, the expression of the apolipoprotein (apo) C-III and A-IV genes is restricted to the enterocytes of the villi. We have previously shown that, in transgenic mice, specific expression of the human apo C-III requires a hormone-responsive element (HRE) located in the distal region of the human apoA-IV promoter. This HRE binds the hepatic nuclear factors (HNF)-4α and γ. Here, intraduodenal injections in mice and infections of human enterocytic Caco-2/TC7 cells with an adenovirus expressing a dominant-negative form of HNF-4α repress the expression of the apoA-IV gene, demonstrating that HNF-4 controls the apoA-IV gene expression in enterocytes. We show that HNF-4α and γ functionally interact with a second HRE present in the proximal region of the human apoA-IV promoter. New sets of transgenic mice expressing mutated forms of the promoter, combined with the human apo C-III enhancer, demonstrate that, whereas a single HRE is sufficient to reproduce the physiological cephalo-caudal gradient of apoA-IV gene expression, both HREs are required for expression that is restricted to villi. The combination of multiple HREs may specifically recruit regulatory complexes associating HNF-4 and either coactivators in villi or corepressors in crypts.

scholarly journals A Distal Region Involving Hepatocyte Nuclear Factor 4α and CAAT/Enhancer Binding Protein Markedly Potentiates the Protein Kinase A Stimulation of the Glucose-6-Phosphatase Promoter

2005 ◽  
Vol 19 (1) ◽  
pp. 163-174 ◽  
Author(s):  
Amandine Gautier-Stein ◽  
Gilles Mithieux ◽  
Fabienne Rajas
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Binding Sites ◽  
Binding Protein ◽  
Distal Region ◽  
Proximal Region ◽  
Nuclear Factor ◽  
Hepatocyte Nuclear Factor ◽  
Enhancer Binding Protein ◽  
Kinase A

Abstract Glucose-6-phosphatase (Glc6Pase) is the last enzyme of gluconeogenesis and is only expressed in the liver, kidney, and small intestine. In these tissues, the mRNA and its activity are increased when cAMP levels increased (e.g. in fasting or diabetes). We first report that a proximal region (within −200 bp relative to the transcription start site) and a distal region (−694/−500 bp) are both required for a potent cAMP and a protein kinase A (PKA) responsiveness of the Glc6Pase promoter. Using different molecular approaches, we demonstrate that hepatocyte nuclear factor (HNF4α), CAAT/ enhancer-binding protein-α (C/EBPα), C/EBPβ, and cAMP response element-binding protein (CREB) are involved in the potentiated PKA responsiveness: in the distal region, via one HNF4α- and one C/EBP-binding sites, and in the proximal region, via two HNF4α and two CREB-binding sites. We also show that HNF4α, C/EBPα, and C/EBPβ are constitutively bound to the endogenous Glc6Pase gene, whereas CREB and CREB-binding protein (CBP) will be bound to the gene upon stimulation by cAMP. These data strongly suggest that the cAMP responsiveness of the Glc6Pase promoter requires a tight cooperation between a proximal and a distal region, which depends on the presence of several HNF4α-, C/EBP-, and CREB-binding sites, therefore involving an intricate association of hepatic and ubiquitous transcription factors.

Regulatory elements controlling pituitary-specific expression of the human prolactin gene

1990 ◽  
Vol 10 (9) ◽  
pp. 4690-4700
Author(s):  
B Peers ◽  
M L Voz ◽  
P Monget ◽  
M Mathy-Hartert ◽  
M Berwaer ◽  
...  
Keyword(s):  
Regulatory Elements ◽  
Distal Region ◽  
Dnase I ◽  
Proximal Region ◽  
Base Pairs ◽  
Specific Expression ◽  
Positive Region ◽  
Dnase I Footprinting ◽  
Human Prolactin ◽  
Flanking Sequences

We have performed transfection and DNase I footprinting experiments to investigate pituitary-specific expression of the human prolactin (hPRL) gene. When fused to the chloramphenicol acetyltransferase (CAT) reporter gene, 5,000 base pairs of the 5'-flanking sequences of the hPRL gene were able to drive high cat gene expression in prolactin-expressing GH3B6 cells specifically. Deletion analysis indicated that this pituitary-specific expression was controlled by three main positive regulatory regions. The first was located just upstream from the TATA box between coordinates -40 and -250 (proximal region). We have previously shown that three motifs of this region bind the pituitary-specific Pit-1 factor. The second positive region was located in the vicinity of coordinates -1300 to -1750 (distal region). DNase I footprinting assays revealed that eight DNA motifs of this distal region bound protein Pit-1 and that two other motifs were recognized by ubiquitous factors, one of which seems to belong to the AP-1 (jun) family. The third positive region was located further upstream, between -3500 and -5000 (superdistal region). This region appears to enhance transcription only in the presence of the distal region.

Effect of imposed head vibration on the stability and waveform of flagellar beating in sea urchin spermatozoa

1991 ◽  
Vol 156 (1) ◽  
pp. 63-80 ◽  
Author(s):  
C. Shingyoji ◽  
I. R. Gibbons ◽  
A. Murakami ◽  
K. Takahashi
Keyword(s):  
Sea Urchin ◽  
Beat Frequency ◽  
Distal Region ◽  
Proximal Region ◽  
Bend Angle ◽  
Vibration Frequencies ◽  
Sliding Velocity ◽  
Additional Energy ◽  
The Stability ◽  
Cyclic Changes

The heads of live spermatozoa of the sea urchin Hemicentrotus pulcherrimus were held by suction in the tip of a micropipette mounted on a piezoelectric device and vibrated either laterally or axially with respect to the head axis. Within certain ranges of frequency and amplitude, lateral vibration of the pipette brought about a stable rhythmic beating of the flagella in the plane of vibration, with the beat frequency synchronized to the frequency of vibration [Gibbons et al. (1987), Nature 325, 351–352]. The sperm flagella, with an average natural beat frequency of 48 Hz, showed stable beating synchronized to the pipette vibration over a range of 35–90 Hz when the amplitude of vibration was about 20 microns or greater. Vibration frequencies below this range caused instability of the beat plane, often associated with irregularities in beat frequency. Frequencies above about 90 Hz caused irregular asymmetrical flagellar beating with a marked decrease in amplitude of the propagated bends and a skewing of the flagellar axis towards one side; the flagella often stopped in a cane shape. In flagella that were beating stably under imposed vibration, the wavelength was reduced at higher frequencies and increased at lower frequencies. When the beat frequency was equal to or lower than the natural beat frequency, the apparent time-averaged sliding velocity of axonemal microtubules, obtained as twice the product of frequency and bend angle, decreased with beat frequency in both the proximal and distal regions of the flagella. However, at vibration frequencies above the natural beat frequency, the sliding velocity increased with frequency only in the proximal region of the flagellum and remained essentially unchanged in more distal regions. This apparent limit to the velocity of sliding in the distal region may represent an inherent limit in the intrinsic velocity of active sliding, while the faster sliding observed in the proximal region may be a result of passive sliding or elastic distortion of the microtubules induced by the additional energy supplied by the vibrating pipette. Axial vibration with frequencies either close to or twice the natural beat frequency induced cyclic changes in the waveform, compressing and expanding the bends in the proximal region, but did not affect bends in the distal region or alter the beat frequency.

Functional morphology of the mouthparts and proventriculus of the rock crab Nectocarcinus tuberculosus (Decapoda: Portunidae)

2003 ◽  
Vol 83 (4) ◽  
pp. 821-834 ◽  
Author(s):  
Indra Raymond Salindeho ◽  
Danielle Jane Johnston
Keyword(s):  
Content Analysis ◽  
Stomach Content ◽  
Stomach Content Analysis ◽  
Distal Region ◽  
Proximal Region ◽  
Rocky Shores ◽  
Brachyuran Crab ◽  
Cardiac Stomach ◽  
Dietary Preferences ◽  
Sea Grass

Mouthpart and proventriculus structure of the brachyuran crab Nectocarcinus tuberculosus was described by scanning electron microscopy and histology and characteristics indicative of dietary preferences were identified. A qualitative stomach content analysis was conducted to verify structural interpretations with respect to diet. The mouthparts and proventriculus of N. tuberculosus have features that are typical of macrophagous crabs and are consistent with a carnivorous diet of hard items. However, the mandibular arrangement indicates that N. tuberculosus is also adapted to ingest soft plant material and fleshy items, revealing that this crab is omnivorous which is consistent with its habitat of rocky shores and sea grass beds. Carnivorous features of the feeding apparatus include large crista dentata on the third maxillipeds that grip food items during ingestion and cuspidate setae on the second maxillipeds and first maxillae. Nectocarcinus tuberculosus has a complex arrangement of proventricular ossicles, 5-denticulated accessory teeth, and a spiny cardio-pyloric valve with rough, calcified protuberances. It has a robust, strongly calcified gastric mill with a prominent anterior cusp and 11 roughly surfaced vertical ridges on each lateral tooth specialized for crushing and grinding. In contrast to true carnivorous crabs, the mandibles in this species are symmetrically arranged, with two sharp cutting edges and no teeth, an arrangement adapted to cut softer plant-like materials and flesh. Structural interpretations with respect to diet were confirmed by stomach content analysis where items identified included gastropods, bivalves and the sea grass Posidonia australis. Functionally, the filtering system in the proventriculus of N. tuberculosus is complex. The cardiac stomach has a well developed ventral filtration system or ‘cardiac filter’ which comprises coarse and fine filters. Different modifications of setation between the distal and proximal regions of the inner valve of the pyloric filter are unique to this crab species, with an intersetule width 600 nm in the distal region and 80–100 nm in the proximal region. This suggests that some differentiation in filtration occurs between regions within the pyloric filter.

Variation in femoral anteversion in patients requiring total hip replacement

2019 ◽  
Vol 30 (3) ◽  
pp. 281-287
Author(s):  
Jim W Pierrepont ◽  
Ed Marel ◽  
Jonathan V Baré ◽  
Leonard R Walter ◽  
Catherine Z Stambouzou ◽  
...  
Keyword(s):  
Total Hip Replacement ◽  
Hip Replacement ◽  
Femoral Stem ◽  
Femoral Anteversion ◽  
Patient Specific ◽  
3 Dimensional ◽  
Total Hip ◽  
Age Related ◽  
Gender And Age ◽  
Implant Alignment

Background: Optimal implant alignment is important for total hip replacement (THR) longevity. Femoral stem anteversion is influenced by the native femoral anteversion. Knowing a patient’s femoral morphology is therefore important when planning optimal THR alignment. We investigated variation in femoral anteversion across a patient population requiring THR. Methods: Preoperatively, native femoral neck anteversion was measured from 3-dimensional CT reconstructions in 1215 patients. Results: The median femoral anteversion was 14.4° (−27.1–54.5°, IQR 7.4–20.9°). There were significant gender differences (males 12.7°, females 16.0°; p < 0.0001). Femoral anteversion in males decreased significantly with increasing age. 14% of patients had extreme anteversion (<0° or >30°). Conclusions: This is the largest series investigating native femoral anteversion in a THR population. Patient variation was large and was similar to published findings of a non-THR population. Gender and age-related differences were observed. Native femoral anteversion is patient-specific and should be considered when planning THR.

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