A Bayesian approach to Mendelian randomization with multiple pleiotropic variants

We propose a Bayesian approach to Mendelian randomization (MR), where instruments are allowed to exert pleiotropic (i.e. not mediated by the exposure) effects on the outcome. By having these effects represented in the model by unknown parameters, and by imposing a shrinkage prior distribution that assumes an unspecified subset of the effects to be zero, we obtain a proper posterior distribution for the causal effect of interest. This posterior can be sampled via Markov chain Monte Carlo methods of inference to obtain point and interval estimates. The model priors require a minimal input from the user. We explore the performance of our method by means of a simulation experiment. Our results show that the method is reasonably robust to the presence of directional pleiotropy and moderate correlation between the instruments. One section of the article elaborates the model to deal with two exposures, and illustrates the possibility of using MR to estimate direct and indirect effects in this situation. A main objective of the article is to create a basis for developments in MR that exploit the potential offered by a Bayesian approach to the problem, in relation with the possibility of incorporating external information in the prior, handling multiple sources of uncertainty, and flexibly elaborating the basic model.

Osmotic Treatment for Quantifying Cell Wall Elasticity in the Sepal of Arabidopsis thaliana

Elastic properties of the cell wall play a key role in regulating plant growth and morphogenesis; however, measuring them in vivo remains a challenge. Although several new methods have recently become available, they all have substantial drawbacks. Here we describe a detailed protocol for osmotic treatments, which is based on the idea of releasing the turgor pressure within the cell and measuring the resulting deformation. When placed in hyperosmotic solution, cells lose water via osmosis and shrink. Confocal images of the tissue, taken before and after this treatment, are quantified using high-resolution surface projections in MorphoGraphX. The cell shrinkage observed can then be used to estimate cell wall elasticity. This allows qualitative comparisons of cell wall properties within organs or between genotypes and can be combined with mechanical simulations to give quantitative estimates of the cells' Young's moduli. We use the abaxial sepal of Arabidopsis thaliana as an easily accessible model system to present our approach, but it can potentially be used on many other plant organs. The main challenges of this technique are choosing the optimal concentration of the hyperosmotic solution and producing high-quality confocal images (with cell walls visualized) good enough for segmentation in MorphoGraphX.

Effect of ultrasound and chemical pretreatment on drying characteristics and quality attributes of hot air dried pineapple slices

Drying of food materials is a time consuming activity making the process cost and energy intensive and hence, several pretreatments are used to improve the drying rate. The present study aims to study the effect of potassium metabisulphite (KMS solution, 0.25% w/v) and ultrasound (20 and 30 min) pretreatment on hot air drying characteristics and quality of pineapple slices. The results indicated that pretreated samples provided higher drying rate, enhanced moisture diffusivity, brighter color and lower hardness than that of untreated dried sample. It was observed that KMS and ultrasound pretreatment for 20 and 30 min reduced the drying time by 23.8%, 19% and 14.3%, respectively. Further, ten thin layer drying models were applied to the experimental drying data and logarithmic model was best fitted to explain the drying behavior of pretreated and untreated samples. Additionally, the effect of shrinkage on moisture transfer mechanism was also studied. Results highlighted that instantaneous moisture diffusivity was increased during drying while shrinkage was not accounted. However, shrinkage consideration reduced the average moisture diffusivity values by 72-83%. Overall color change (13.95 ± 0.92) and browning index (36.02 ± 2.45) were found to be lowest in ultrasound (30 min) pretreated dried sample, highlighting better color stability. Scanning electron microscopy presented noticeable effects of pretreatment on alterations of microstructure of pineapple slices. It can be interpreted that KMS pretreatment was found to be more effective for improvement of drying characteristics of pineapple slices as compared to ultrasound pretreatment.

Measurement of the shrinkage of natural and simulated lesions on root surfaces using CP-OCT

OBJECTIVES

Demineralized root dentin and cementum is made up of mostly collagen that shrinks significantly upon dehydration or drying with air. During remineralization mineral is deposited on the outside of the lesion creating a highly mineralized surface layer that inhibits diffusion, arrests the lesion and prevents shrinkage. Previous studies suggest that active root caries lesions manifest shrinkage, while arrested lesions no longer manifest shrinkage upon dehydration. The purpose of this study was to demonstrate that the shrinkage of root caries lesions can be monitored during dehydration using an optical coherence tomography probe suitable for clinical use.

METHODS

In this in vitro study the shrinkage of simulated and natural root caries lesions on extracted teeth was measured using a cross polarization optical coherence tomography (CP-OCT) system and a 3D printed appliance with an integrated air nozzle suitable for clinical use. Two methods were employed to assess shrinkage, changes in the position of the lesion surface and changes in the thickness of the lesion.

RESULTS

CP-OCT was successful in measuring a significant (P < 0.05) contraction of the lesion surface, significant decrease in the lesion thickness and increase in the reflectivity per micron upon drying natural lesions on extracted teeth.

CONCLUSIONS

In this preclinical study, we have demonstrated that a CP-OCT handpiece modified for infection control with an attached air nozzle suitable for in vivo use can be used to monitor the shrinkage of root caries lesions. In addition, we have developed a new approach to measuring lesion shrinkage with OCT, namely monitoring changes in the lesion thickness as opposed to the position of the lesion surface, that does not require an initial reference position and is more easily implemented in vivo.

Hybrid MRI guided radiotherapy in locally advanced cervical cancer: Case report of an innovative personalized therapeutic approach

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The case report of a patient affected by locally advanced cervical MRgRT is described.

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MRgRT appears to be feasible for cervical cancer and may improve treatment quality.

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MRgRT insights are discussed focusing on adaptive response and toxicity monitoring.

Adhesive class I restorations in sound molar teeth incorporating combined resin-composite and glass ionomer materials: CAD-FE modeling and analysis

OBJECTIVES

To investigate the influence of different resin composite and glass ionomer cement material combinations in a "bi-layer" versus a "single-layer" adhesive technique for class I cavity restorations in molars using numerical finite element analysis (FEA).

MATERIALS AND METHODS

Three virtual restored lower molar models with class I cavities 4mm deep were created from a sound molar CAD model. A combination of an adhesive and flowable composite with bulk fill composite (model A), of a glass ionomer cement with bulk fill composite (model B) and of an adhesive with bulk fill composite (model C), were considered. Starting from CAD models, 3D-finite element (FE) models were created and analyzed. Solid food was modeled on the occlusal surface and slide-type contact elements were used between tooth surface and food. Polymerization shrinkage was simulated for the composite materials. Physiological masticatory loads were applied to these systems combined with shrinkage. Static linear analyses were carried out. The maximum normal stress criterion was adopted as a measure of potential damage.

RESULTS

All models exhibited high stresses principally located along the tooth tissues-restoration interfaces. All models showed a similar stress trend along enamel-restoration interface, where stresses up to 22MPa and 19MPa was recorded in the enamel and restoration, respectively. A and C models showed a similar stress trend along the dentin-restoration interface with a lower stress level in model A, where stresses up to 11.5MPa and 7.5MPa were recorded in the dentin and restoration, respectively, whereas stresses of 17MPa and 9MPa were detected for model C. In contrast to A and C models, the model B showed a reduced stress level in dentin, in the lower restoration layer and no stress on the cavity floor.

SIGNIFICANCE

FE analysis supported the positive effect of a "bi-layer" restorative technique in a 4mm deep class I cavities in lower molars versus "single-layer" bulk fill composite technique.

Surgical and radiological behavior of MRI-depictable mesh implants after TAPP repair: the IRONMAN study

PURPOSE

Knowledge of postoperative behavior of mesh implants used for hernia repair is generally limited to cases of recurrence, local complications or return to the previous operative field in other pathological conditions. Previous studies with MRI-visible mesh implants in different parts of the abdominal wall have led to variable findings with regard to mesh properties and mostly described a reduction in size over time with subsequently limited mesh overlap over hernia defects which could contribute to recurrence. We aimed to evaluate implant properties in a mechanically stable anatomical region after TAPP repair of primary unilateral inguinal hernias in men with clinical and MRI examinations 4 weeks and 1 year after surgery.

METHODS

From 11/2015 to 01/2019, 23 men with primary, unilateral, inguinal hernias underwent TAPP repair with iron particle-loaded, MRI-visible mesh implants in a prospective cohort study. In 16 patients the operative outcome could be evaluated 4 weeks and 12 months after surgery by clinical examination and MRI evaluation with regard to postoperative course, possible adverse outcomes and radiological findings related to implant behavior-namely MRI-identifiability, mesh dislocation or reduction in surface area.

RESULTS

All included patients had an uneventful postoperative clinical course. MRI after 4 weeks revealed one postoperative seroma, which resolved spontaneously. No recurrence was detected. Mesh implants could be accurately delineated in DIXON-IN studies and showed neither clinically nor statistically significant changes in size or position.

CONCLUSION

4 weeks and 1 year after a standardized TAPP procedure the mesh implant used in this study showed no tendency towards dislocation or reduction in size in this anatomical position. Its MRI visibility allows accurate delineation during the postoperative course by experienced radiologists in appropriate MRI protocols. Larger patient series are desirable to further support these findings. Shrinkage of implants in the groin as a reason for early recurrence may be overestimated.

Increased ENaC activity during kidney preservation in Wisconsin solution

Background

The invention of an effective kidney preservation solution capable of prolonging harvested kidney viability is the core of kidney transplantation procedure. Researchers have been working on upgrading the preservation solution quality aiming at prolonging storage time while maintaining utmost organ viability and functionality. For many years, the University of Wisconsin (UW) solution has been considered the gold standard solution for kidney preservation. However, the lifespan of kidney preservation in the UW solution is still limited. Its impact on the epithelial Na⁺ channel (ENaC) activity and its mediated processes is unknown and the primary goal of this study.

Methods

Kidneys harvested from 8 weeks old Sprague Dawley rats were divided into 4 groups depending upon the period of preservation in UW solution. Additional analysis was performed using dogs’ kidneys. ENaC activity was measured using patch clamp technique; protein expression and mRNA transcription were tested through Western blot and RT-qPCR, respectively. A colorimetric LDH level estimation was performed at different time points during UW solution preservation.

Results

Kidney preservation in Wisconsin solution caused reduction of the kidney size and weight and elevation of LDH level. ENaC activity increased in both rat and dog kidneys preserved in the UW solution as assessed by patch clamp analysis. On the contrary, ENaC channel mRNA levels remained unchanged.

Conclusions

ENaC activity is significantly elevated in the kidneys during preservation in UW solution, which might affect the immediate post-implantation allograft function and trajectory post-transplant.

Combustion behaviour and dominant shrinkage mechanism of flexible polyurethane foam in the cone calorimeter test

The shrinkage is an important thermal response of flexible polyurethane foam (FPUF) in fire, which couples its first combustion stage and influences the initial fire spread. In this paper the combustion and shrinkage behaviours are quantitatively investigated and the shrinkage mechanisms are discussed. The critical heat flux for the shrinkage is about 13 kW/m², between the critical heat flux for piloted ignition and that for non-piloted ignition. Above the critical value the shrinkage rate increases linearly with increasing the heat flux. As the foam density decreases both the shrinkage rate and the first peak of Figra curve which reflects the initial fire spread rate increase. The perceptible shrinkage originates from the decomposition via which the struts convert to the melts. Both the shrinking of struts and the gasification play a minor role. The collapse of porous structure, namely the melts filling into the pores to form the tar layer, dominates the shrinkage. The tar is composed of polyols produced after the first decomposition stage. Beneath the tar layer the porous structure is unchanged. To reduce the fire hazards of FPUF by its heat insulation merit it needs to maintain the porous structure at the first decomposition stage.

Real-time in-depth imaging of gap formation in bulk-fill resin composites

OBJECTIVES

This study visualized in real-time the gap forming of bulk-fill resin composites during polymerization using optical coherence tomography (OCT).

METHODS

Light-cured bulk-fill resin composites; Tetric N-ceram Bulk Fill (TNB), SonicFill (SNF), Surefil SDR (SDR), dual-cured bulk-fill resin composite Bulk EZ (BEZ), and light-cured core resin composite Clearfil Photo Core (CPC) were investigated. Swept-source OCT real-time cross-sectional monitoring was obtained during resin composite placement and curing procedure. Gap formation was observed in bonded cylindrical resin composite molds (4-mm depth, 3-mm diameter) and free shrinkage volume was observed at the top and bottom of a tube with similar dimensions (n=10). OCT 3D data were analyzed to calculate sealing floor area percentage (SFA%) and volumetric shrinkage in bonded tube (VS%). Data were analyzed by ANOVA at significance level of 0.05. The bottom-top degree of conversion ratio (DC%-R) through 4-mm depth was measured using the XploRA Plus micro-Raman spectroscopy.

RESULTS

BEZ showed no gap formation at the cavity floor in any specimens while SNF showed the highest gap formation; the statistical order in terms of SFA% was BEZ (100±0)>TNB (84.97±2.98)>CPC (52.13±8.23)=SDR (45.97±9.21)>SNF (16.23±6.00) (p<0.05). On the other hand, total VS% was statistically ordered as BEZ (3.40±0.14)>SDR (3.22±0.09)>TNB (1.82±0.11)>SNF (1.65±0.04)=CPC (1.56±0.04) (p<0.05). Unlike BEZ, the light-cured resin composites showed larger shrinkage at specimen bottom than top. TNB showed the lowest DC%-R followed by SNF (p<0.05).

SIGNIFICANCE

Light-cured bulk-fill resin composites showed various degrees of gap formation and shrinkage at 4-mm deep cavity. The dual-cured bulk-filled resin composite showed no decrease of degree of conversion through the depth and the highest cavity adaptation despite its tendency for higher volumetric shrinkage.

Semi-parametric Bayesian regression for subgroup analysis in clinical trials

Determining whether there are differential treatment effects in subgroups of trial participants remains an important topic in clinical trials as precision medicine becomes ever more relevant. Any assessment of differential treatment effect is predicated on being able to estimate the treatment response accurately while satisfying constraints of balancing the risk of overlooking an important subgroup with the potential to make a decision based on a false discovery. While regression models, such as marginal interaction model, have been widely used to improve accuracy of subgroup parameter estimates by leveraging the relationship between treatment and covariate, there is still a possibility that it can lead to excessively conservative or anti-conservative results. Conceivably, this can be due to the use of the normal distribution as a default prior, which forces outlying subjects to have their means over-shrunk towards the population mean, and the data from such subjects may be excessively influential in estimation of both the overall mean response and the mean response for each subgroup, or a model mis-specification. To address this issue, we investigate the use of nonparametric Bayes, particularly Dirichlet process priors, to create semi-parametric models. These models represent uncertainty in the prior distribution for the overall response while accommodating heterogeneity among individual subgroups. They also account for the effect and variation due to the unaccounted terms. As a result, the models do not force estimates to excessively shrink but still retain the attractiveness of improved precision given by the narrower credible intervals. This is illustrated in extensive simulations investigating bias, mean squared error, coverage probability and credible interval widths. We applied the method on a simulated data based closely on the results of a cystic fibrosis Phase 2 trial.

Feasibility of manufacturing ultra-high performance cement-based composites (UHPCCs) with recycled sand: A preliminary study

Due to the excellent mechanical and durability properties, ultra-high performance cement-based composites (UHPCCs) have attracted a lot of attention during the past decades. It is noted that most existing UHPCCs are manufactured from raw materials with high quality, for instance, well-graded river sands. However, the huge consumption of river sands as construction materials has inevitably resulted in some serious ecological impacts, as reported around the world. In this regard, it shall be much beneficial if some substitutes, such as recycled sands produced through processing of construction and demolition waste (CDW), could be used to replace natural sands to manufacture the qualified UHPCCs. This paper presents such a preliminary study on the feasibility of manufacturing UHPCCs with recycled sands. A total of five UHPCCs are designed and cast with different replacement percentages of recycled sand, i.e., 0%, 30% 50%, 70% and 100% (in mass). The associated packing density of the mixed sands is estimated based on the linear packing model. The fresh and hardened properties of the UHPCCs, including the workability, strength and shrinkage, are experimentally examined. The test results indicate that it is possible to use recycled sand to replace natural river sand in the manufacture of UHPCCs; however, the amount of the recycled sand needs to be limited. In the case when the replacement percentage of the recycled sand is lower than 50% (in mass), the properties of the UHPCCs with the recycled sand are comparable with those containing river sand only.

Additive quantile regression for clustered data with an application to children's physical activity

Additive models are flexible regression tools that handle linear as well as non-linear terms. The latter are typically modelled via smoothing splines. Additive mixed models extend additive models to include random terms when the data are sampled according to cluster designs (e.g. longitudinal).These models find applications in the study of phenomena like growth, certain disease mechanisms and energy expenditure in humans, when repeated measurements are available. We propose a novel additive mixed model for quantile regression. Our methods are motivated by an application to physical activity based on a data set with more than half a million accelerometer measurements in children of the UK Millennium Cohort Study. In a simulation study, we assess the proposed methods against existing alternatives.

A concise review of optical, physical and isotropic fractionator techniques in neuroscience studies, including recent developments

Stereology is a collection of methods which makes it possible to produce interpretations about actual three-dimensional features of objects based on data obtained from their two-dimensional sections or images. Quantitative morphological studies of the central nervous system have undergone significant development. In particular, new approaches known as design-based methods have been successfully applied to neuromorphological research. The morphology of macroscopic and microscopic structures, numbers of cells in organs and structures, and geometrical features such as length, volume, surface area and volume components of the organ concerned can be estimated in an unbiased manner using stereological techniques. The most practical and simplest stereological method is the fractionator technique, one of the most widely used methods for total particle number estimation. This review summarizes fractionator methods in theory and in practice. The most important feature of the methods is the simplicity of its application and underlying reasoning. Although there are three different types of the fractionator method, physical, optical and isotropic (biochemical), the logic underlying its applications remains the same. The fractionator method is one of the strongest and best options among available methods for estimation of the total number of cells in a given structure or organ. The second part of this review focuses on recent developments in stereology, including how to deal with lost caps, with tissue section deformation and shrinkage, and discusses issues of calibration, particle identification, and the role of stereology in the era of a non-histological alternative to counting of cells, the isotropic fractionator (brain soup technique).

Free gingival graft adjunct with low-level laser therapy: a randomized placebo-controlled parallel group study

OBJECTIVES

This study aimed to evaluate the effect of low-level laser therapy (LLLT) in terms of enhancing wound healing, reducing free gingival graft (FGG) shrinkage and postoperative pain.

MATERIALS AND METHODS

Thirty patients were randomly assigned to receive either FGG + LLLT (test, n = 15) or FGG + plasebo LLLT (control, n = 15). In the test group, a diode laser (810 nm, 0.1 W, energy density 6 J/cm²) was applied immediately after surgery and 1, 3, 7, and 14 days later. Measurements of the graft surface areas of the groups were made with an image-analyzing software at baseline and first, third, and sixth months. Complete wound epithelialization and visual analogue scale (VAS) for pain score were evaluated after surgery.

RESULTS

Shrinkage of the graft was statistically higher in the control than the test group at third and sixth months (p < 0.05). In terms of epithelization of the graft area, the test and control groups did not show any significant difference during the 28-day period (p > 0.05). Besides this, statistically significant differences were observed for VAS pain score and the number of analgesic used (p < 0.05).

CONCLUSIONS

The use of an 810-nm diode laser provided additional benefits to FGG in terms of less shrinkage of the graft dimensions and postoperative pain.

CLINICAL RELEVANCE

Low-level laser therapy reduced the shrinkage of free gingival graft's surface area after 6 months and enhanced postoperative pain relief.

Perioperative factors associated with aneurysm sac size changes after endovascular aneurysm repair

PURPOSE

To identify the perioperative factors associated with aneurysm size changes after endovascular aortic aneurysm repair (EVAR).

METHODS

Between August, 2008 and December, 2014, 187 patients underwent EVAR treatment in our institution. The subjects of this study were 135 of these patients without peripheral artery disease, who were followed up with computed tomography (CT) for 3 years. Significant aneurysm size change was defined as sac size change of more than 5 mm from the baseline.

RESULTS

Sac enlargement was identified in 25 patients (18.5%) and sac shrinkage was identified in 59 (43.7%) patients. The factors associated with sac enlargement were postoperative pulse wave velocity (OR: odds ratio 3.80, p = 0.047), prevalence of a type 2 endoleak 1 week after surgery (OR 4.26, p = 0.022), inner diameter (OR 1.10, p = 0.005), and distance from the lower renal artery to the terminal aorta (OR 1.05, p = 0.017). The factors associated with sac shrinkage were prevalence of a type 2 endoleak (OR 0.09, p < 0.001) and preoperative pulse wave velocity (OR 0.32, p = 0.022). The factors independently associated with type 2 endoleak were the use of an Excluder device (OR 3.99, p = 0.002) and the length of the aneurysm (OR 1.02, p = 0.027).

CONCLUSION

Inner diameter, treatment length, perioperative pulse wave velocity, and type 2 endoleak were associated with sac size changes after EVAR.

Intracoronal stress transfer through enamel following RBC photopolymerisation: A synchrotron X-ray study

OBJECTIVES

To measure the spatial distribution of crystallographic strain in tooth enamel induced by the photo-polymerisation of a dimethacrylate resin based composite cavity restoration.

METHODS

Six sound first premolar teeth, allocated into two groups (n=3), were prepared with mesio-occlusal distal cavities. The enamel was machined at the point of maximum convexity on the outer tooth to create a vertical fin of thickness 100μm and 0.5mm depth to allow for synchrotron X-ray diffraction measurements. 2D diffraction patterns were used to determine crystallite orientation and quantify changes in the hydroxyapatite crystal lattice parameters, before and after photo-polymerisation of a composite material placed in the cavity, to calculate strain in the respective axis. The composite was photo-polymerised with either relatively high (1200mWcm^-2, group 1) or low (480mWcm^-2, group 2) irradiances using LED or quartz halogen light sources, respectively. A paired t-test was used to determine significant differences in strain between irradiance protocols at ɑ=0.001.

RESULTS

Photo-polymerisation of the composite in the adjacent cavity induced significant changes in both the crystallographic c and a axes of the enamel measurement area. However the magnitude of strain was low with ∼0.1% difference before and after composite photo-polymerisation. Strain in enamel was not uniformly distributed and varied spatially as a function of crystallite orientation. Increased alignment of crystallites perpendicular to the cavity wall was associated with higher c axis strain. Additionally, strain was significantly greater in the c (p<0.001) and a axis (p<0.001) when using a high irradiance photo-polymerisation protocol.

SIGNIFICANCE

Although cuspal deflection is routinely measured to indirectly assess the 'global' effect of composite shrinkage on the tooth-restoration complex, here we show that absolute strains generated in enamel are low, indicating strain relief mechanisms may be operative. The use of low irradiance protocols for photo-polymerisation resulted in reduced strain.

Bayesian Semiparametric Multivariate Density Deconvolution

We consider the problem of multivariate density deconvolution when interest lies in estimating the distribution of a vector valued random variable X but precise measurements on X are not available, observations being contaminated by measurement errors U. The existing sparse literature on the problem assumes the density of the measurement errors to be completely known. We propose robust Bayesian semiparametric multivariate deconvolution approaches when the measurement error density of U is not known but replicated proxies are available for at least some individuals. Additionally, we allow the variability of U to depend on the associated unobserved values of X through unknown relationships, which also automatically includes the case of multivariate multiplicative measurement errors. Basic properties of finite mixture models, multivariate normal kernels and exchangeable priors are exploited in novel ways to meet modeling and computational challenges. Theoretical results showing the flexibility of the proposed methods in capturing a wide variety of data generating processes are provided. We illustrate the efficiency of the proposed methods in recovering the density of X through simulation experiments. The methodology is applied to estimate the joint consumption pattern of different dietary components from contaminated 24 hour recalls. Supplementary Material presents substantive additional details.

The effects of graft shrinkage and extrusion on early clinical outcomes after meniscal allograft transplantation

BACKGROUND

Graft shrinkage or radial extrusion is a reported complication after meniscus allograft transplantation (MAT). Whether shrinkage or extrusion progress after surgery and whether they are associated with the clinical outcome of MAT remain debatable. In this study, graft shrinkage and extrusion were measured in the coronal and sagittal planes using serial postoperative magnetic resonance imaging (MRI). The purpose of this study was to evaluate if graft shrinkage or extrusion is correlated to the clinical outcome of MAT.

METHODS

MRIs acquired at 3 and 12 months postoperatively in 30 patients (21 men and 9 women) who underwent MAT (6 medial and 24 lateral menisci) from 2010 to 2016 were analyzed. Two orthopedic surgeons and two musculoskeletal specialized radiologists each performed the MRI measurements. Allograft shrinkage was measured by the width and thickness of the graft at the coronal and sagittal planes. To determine the graft extrusion, distances between the proximal tibia cartilage margin and the extruded graft margin were measured in both coronal (either lateral or medial) and sagittal (both anterior and posterior) plane and relative percentage of extrusion (RPE) were calculated. Subjective International Knee Documentation Committee (IKDC) scores at 12 months were evaluated as a clinical outcome measurement, and correlations between shrinkage or extrusion of allograft and IKDC score were analyzed.

RESULTS

In the coronal plane, radial RPE averaged 43.6% at postoperative 3 months, but there was no significant progression of extrusion at 12 months (average 42.0%) (P = 0.728). In the sagittal plane, there were no significant progressions of anterior and posterior RPE (P = 0.487 and 0.166, respectively) between postoperative 3 and 12 months. Shrinkage was calculated by multiplying the width and height of the three sections and summing these values. There was no significant progression of shrinkage between postoperative 3 and 12 months (P = 0.150). RPE in the radial (R = 0.147, P = 0.525), anterior (R = 0.249, P = 0.264), and posterior (R = 0.230, P = 0.315) directions and shrinkage (R = 0.176, P = 0.435) were not correlated to IKDC score at postoperative 12 months.

CONCLUSIONS

In the coronal and sagittal planes, extrusion and shrinkage did not progress from 3 months to 1 year. Extrusion and shrinkage had no correlation with early clinical outcomes. This finding suggests that graft extrusion or shrinkage may be not a great concern especially in early postoperative period of MAT, and multiple, serial MRI may be not necessary.

Distributed Lag Interaction Models with Two Pollutants

Distributed lag models (DLMs) have been widely used in environmental epidemiology to quantify the lagged effects of air pollution on a health outcome of interest such as mortality and morbidity. Most previous DLM approaches only consider one pollutant at a time. In this article, we propose distributed lag interaction model (DLIM) to characterize the joint lagged effect of two pollutants. One natural way to model the interaction surface is by assuming that the underlying basis functions are tensor products of the basis functions that generate the main-effect distributed lag functions. We extend Tukey's one-degree-of-freedom interaction structure to the two-dimensional DLM context. We also consider shrinkage versions of the two to allow departure from the specified Tukey's interaction structure and achieve bias-variance tradeoff. We derive the marginal lag effects of one pollutant when the other pollutant is fixed at certain quantiles. In a simulation study, we show that the shrinkage methods have better average performance in terms of mean squared error (MSE) across different scenarios. We illustrate the proposed methods by using the National Morbidity, Mortality, and Air Pollution Study (NMMAPS) data to model the joint effects of PM₁₀ and O₃ on mortality count in Chicago, Illinois, from 1987 to 2000.

Improved estimation of subject-level functional connectivity using full and partial correlation with empirical Bayes shrinkage

Reliability of subject-level resting-state functional connectivity (FC) is determined in part by the statistical techniques employed in its estimation. Methods that pool information across subjects to inform estimation of subject-level effects (e.g., Bayesian approaches) have been shown to enhance reliability of subject-level FC. However, fully Bayesian approaches are computationally demanding, while empirical Bayesian approaches typically rely on using repeated measures to estimate the variance components in the model. Here, we avoid the need for repeated measures by proposing a novel measurement error model for FC describing the different sources of variance and error, which we use to perform empirical Bayes shrinkage of subject-level FC towards the group average. In addition, since the traditional intra-class correlation coefficient (ICC) is inappropriate for biased estimates, we propose a new reliability measure denoted the mean squared error intra-class correlation coefficient (ICCMSE) to properly assess the reliability of the resulting (biased) estimates. We apply the proposed techniques to test-retest resting-state fMRI data on 461 subjects from the Human Connectome Project to estimate connectivity between 100 regions identified through independent components analysis (ICA). We consider both correlation and partial correlation as the measure of FC and assess the benefit of shrinkage for each measure, as well as the effects of scan duration. We find that shrinkage estimates of subject-level FC exhibit substantially greater reliability than traditional estimates across various scan durations, even for the most reliable connections and regardless of connectivity measure. Additionally, we find partial correlation reliability to be highly sensitive to the choice of penalty term, and to be generally worse than that of full correlations except for certain connections and a narrow range of penalty values. This suggests that the penalty needs to be chosen carefully when using partial correlations.

Shrinkage and porosity evolution during air-drying of non-cellular food systems: Experimental data versus mathematical modelling

In the present work, the impact of glass transition on shrinkage of non-cellular food systems (NCFS) during air-drying will be assessed from experimental data and the interpretation of a 'shrinkage' function involved in a mathematical model. Two NCFS made from a mixture of water/maltodextrin/agar (w/w/w: 1/0.15/0.015) were created out of maltodextrins with dextrose equivalent 19 (MD19) or 36 (MD36). The NCFS made with MD19 had 30°C higher Tg than those with MD36. This information indicated that, during drying, the NCFS with MD19 would pass from rubbery to glassy state sooner than NCFS MD36, for which glass transition only happens close to the end of drying. For the two NCFS, porosity and volume reduction as a function of moisture content were captured with high accuracy when represented by the mathematical models previously developed. No significant differences in porosity and in maximum shrinkage between both samples during drying were observed. As well, no change in the slope of the shrinkage curve as a function of moisture content was perceived. These results indicate that glass transition alone is not a determinant factor in changes of porosity or volume during air-drying.

Prospective cohort study on mesh shrinkage measured with MRI after laparoscopic ventral hernia repair with an intraperitoneal iron oxide-loaded PVDF mesh

BACKGROUND

Current data on shrinkage of intraperitoneal meshes come mainly from animal studies. High-quality human data in prospective studies are scarce.

METHODS

We used the ability to visualize intraperitoneal PVDF meshes enhanced with iron particles (DynaMesh IPOM visible) with magnetic resonance imaging (MRI) to determine the amount of shrinkage between 1 and 13 months postoperatively. All measurements of the width, length, and surface area of the mesh were performed with a standardized methodology independently by four radiologists blinded for the timing of the MRI.

RESULTS

Of the 15 patients undergoing laparoscopic ventral hernia repair, 13 patients received an MRI both at 1 and at 13 months. Evaluation of inter-rater reliability between the radiologists showed intra-class correlations of 0.95 (95% CI 0.92-0.98) for the width, 0.96 (95% CI 0.93-0.98) for the length, and 0.99 (90% CI 0.99-1.00) for the surface area of the mesh. The change between measurement at implantation and 1-month MRI was - 0.7 cm (P = 0.023; - 3.6%) for the width and - 1.9 cm (P = 0.001; - 7.2%) for the length. The change between 1 and 13 months was - 0.06 cm (P = 0.74; shrinkage = 0.3%) for the width, - 0.12 cm (P = 0.56; shrinkage = 0.5%) for the length, and - 4.0 cm² (P = 0.20; shrinkage = 1.0%) for the surface area of the mesh.

CONCLUSION

There is excellent inter-rater reliability between radiologists when measuring width, length, and surface area of visible intraperitoneal PVDF mesh with MRI. There is no significant shrinkage between 1 and 13 months of intraperitoneal PVDF mesh after laparoscopic ventral hernia repair.

Data on optimum recycle aggregate content in production of new structural concrete

This data presented herein are the research summary of “mechanical behavior and durability performance of concrete containing recycled concrete aggregate” (Paul, 2011) [1]. The results reported in this article relate to an important parameter of optimum content of recycle concrete aggregate (RCA) in production of new concrete for both structural and non-structural applications. For the purpose of the research various types of physical, mechanical and durability tests are performed for concrete made with different percentages of RCA. Therefore, this data set can be a great help of the readers to understand the mechanism of RCA in relates to the concrete properties.

Shrinkage in oral squamous cell carcinoma: An analysis of tumor and margin measurements in vivo, post-resection, and post-formalin fixation

PURPOSE

To quantify changes in tumor size and tumor-free margins following surgical resection and formalin fixation of oral cavity squamous cell carcinoma.

MATERIALS AND METHODS

Nineteen patients were studied via cohort design. Between May and December 2011, measurements of tumor size and tumor-free margin were made in patients with squamous cell carcinoma of the oral cavity. Mucosal reference points were marked with sutures, representing tumor diameter and two separate resection margins. Measurements were recorded immediately before resection, after resection, and following fixation in formalin.

RESULTS

The overall mean shrinkage in tumor size was 10.7% (95% CI 3.4-18.0, p=0.006). When comparing mean tumor measurements, most of the tumor size decrease (6.4%, 95% CI 0.4-12.4, p=0.039) occurred between pre- and post-excision measurements. To a lesser extent, tumor size decreased following formalin fixation. Comparison of tumor-free margin measurements revealed a pre-excision to post-fixation mean decrease of 11.3% (95% CI 2.9-19.6%, p=0.011), with a statistically significant decrease of 14.9% (95% CI 8.5-21.3%, p<0.001) occurring between pre- and post-excision, and no significant decrease from post-excision to post-formalin fixation.

CONCLUSION

Mucosal dimensions of both tumor and tumor-free margins in oral cavity squamous cell carcinoma specimens decrease between surgical resection and pathologic analysis. Most of this decrease occurs prior to fixation, especially for margins, and may be due to intrinsic tissue properties rather than formalin effects.