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The BES TEST™ (Bone Elastic Structure Test), is a recently developed software medical device that detects pathological changes of bone trabecular architecture by measuring its elastic characteristics, known to be directly related to its resistance. The results are expressed by the Bone Structure Index (BSI) or by its T-score, that is the number of standard deviations from the healthy population average. Purpose: Evaluate the precision of BES TEST™ under reproducibility conditions, defined as repeated measurements on the same or similar objects which include different locations, operators, and measuring systems. Methods: A total of 51 replicate measurements were performed by four different operators on five different phantoms. Each phantom was 3D printed using Stereolithography (SLA) and Fused Deposition Modeling (FDM) and has a unique internal structure that mimics trabecular bone. ISO 5725 guidelines were followed for the interpretation of results. Results: The 3D-printed phantoms performed like real bones when analyzed with BES TEST™. The reproducibility 95% Confidence Interval expressed in BSI is [Formula: see text], which corresponds in T-score to [Formula: see text]. The Least Significant Change in BSI is [Formula: see text], which corresponds to [Formula: see text]. Conclusion: The reproducibility of BES TEST™ within the admissible range is not inferior to that of gold standard tests for osteoporosis. 3D printing proved a valuable tool to perform reliable replicate measurements without having patients undergo unnecessary tests.

Additive manufacturing played a keyrole in investigating the precision of a recently-developed device that measures the elastic characteristics of the trabecular bone by simulating the application of loads on a virtual biopsy obtained from radiographic images of the proximal epiphyses in the patient’s hand fingers. The simulation results are combined in a Bone Structure Index (BSI), which has shown to be able to detect trabecular bone alterations due to osteoporosis or other pathological situations. In order to obtain a large number of measurements without having voluntary patients undergo unnecessary radiations, the precision assessment tests were carried out on a 3D-printed phantom hand, in which different mimicked trabecular structures (chips) were inserted. Each mimicked bone had a unique internal structure and density and was 3D-printed using radiopaque composite materials. Fifteen different chips were additively manufactured; 20 measurements were performed on each chip. BSI and BSI_T-score precision values were computed according to ISO 5725 and ISCD standards. For all the chips, no relationship was found between the mean [Formula: see text] and standard deviation [Formula: see text] of the measurements in each chip. The range of the 95% confidence interval ([Formula: see text]) was computed assuming the repeatability standard deviation [Formula: see text] as the known standard deviation of the measurement method (average of [Formula: see text] values): [Formula: see text], corresponding to [Formula: see text]. Least Significant Change was evaluated as well: [Formula: see text], corresponding to [Formula: see text]. The 95% confidence intervals are small when compared to the commonly-accepted diagnostic values, where a patient is classified as osteoporotic if T-score -1 and osteopoenic if -2.5

Background and Aims Chronic kidney disease is a frequent condition, characterized, especially in its more advanced stages, by an array of derangements in bone structure and density, resulting in a higher rate of bone fractures. Current strategies to monitor the bone status and assess the risk of bone fractures in CKD patients are limited. The Bone Elastic Structure (BES) test is a recently-developed non-invasive tool that measures the elastic characteristics of the trabecular bone by simulating the application of loads on a virtual biopsy obtained from radiographic images of the proximal epiphyses in the patient’s hand fingers. The simulation results are combined to obtain a parameter defined Bone Structure Index (BSI). The aim of our study is to explore whether the BES test could be a useful monitoring tool of bone status in patients with CKD on dialysis by exploring whether such patients have different BSI values compared with persons without CKD. Method The BES test was performed on a sample of 41 patients undergoing chronic hemodialysis (HD) and the BSI compared with a group of 374 persons with normal renal function who had undergone the BES test in previous studies. Differences in BSI and 95% confidence intervals (CIs) between the two groups were obtained and tested for statistical significance with a linear regression model including BSI as the dependent variable and kidney status (HD vs no HD) as the independent variable, adjusted for age and sex. Subgroup effects were explored by including interaction terms (age x kidney status, age x sex, kidney status x sex) in the model. Finally, to further remove the potential confounding by age and sex, each HD patient was individually matched with up to 4 non-HD participants based on sex and age (with a 5-year caliper) and a matched analysis was conducted on BSI values. Results Average (SD) age was 64 (17) years in the HD group and 60 (12) years in the non-HD group, with a prevalence of males of 49% and 16%, respectively. The individual values of BSI divided by kidney status and sex in Figure. The multivariate linear regression model showed that, after adjustment for age and sex, the BSI in the HD group was significantly lower compared with the non-HD group (HD 145, 95% CI 140, 154; non-HD 179, 95% CI 177, 181; absolute difference −32, 95% CI −40, −25; p-value < 0.001). There was no significant interaction between age, sex and kidney status on BSI values (all p-values > 0.05). Individual matching was successful for 36 out of 41 HD patients, who were matched to 127 non-HD participants; matched analysis confirmed the results (absolute difference −31, 95% CI −40, −23; p-value < 0.001). Conclusion The output of a non-invasive tool to determine the bone elastic structure appeared to be strongly associated with kidney function after control for differences in age and sex. Further studies are needed to determine the potential application of the BES test in patients with CKD.

Devices for training of healthcare specialists are widespread applications of 3D printing. BES TEST™ is an innovative test for the diagnosis of osteoporosis and similar bone diseases, based on mechanical simulations performed on a virtual biopsy of the patient’s fingers, obtained by radiograms. Operator training is performed on a phantom hand, which is held in place by a specifically-designed support, which was 3D printed using stereolithography (SLA) with Formlabs Tough V5™ resin. Our aim is twofold: (1) perform a mechanical characterization of the resin and (2) verify that the obtained material characteristics can be used for the design of 3D-printed parts, in particular the phantom hand support. Tensile tests were performed following ISO-527. FEM analyses were carried out on the support CAD model adopting the experimentally-obtained material properties. The calculated displacements were compared with those measured experimentally on the prototype, which was manufactured using the same 3D printing and post-curing parameters as the tensile samples. FEM and experimental results were in very good agreement (error < 5.5%): this confirms that, when studying the mechanical performance of SLA 3D-printed parts, it is good practice to characterize the resin using the same printing and post-curing parameters as the final part.

Stereolithography (SLA) is becoming a more and more popular 3D-printing method. Improvement in material properties encourages makers and engineers to embrace this technology even for load-bearing applications. Mechanical properties of 3D-printed materials are difficult to obtain from technical datasheets and, even when available, these data are often unreliable, since they depend strongly on the specific printing parameters applied. Therefore, it is often necessary to perform an in-house mechanical characterization. In this work, tensile tests are performed with a basic in-house-designed tester on SLA 3D-printed specimens; these are printed at different orientations on a Formlabs™ Form 2™ using Clear V4™ resin. The ultimate tensile strength, Young’s modulus, strain at maximum stress and strain at break are calculated. No relationship is found between printing angle and mechanical characteristics; therefore, this 3D-printed material can be considered isotropic. Results are compared with the manufacturer’s datasheet: the measured maximum stress is slightly lower than that stated by Formlabs™, while the modulus is nearly the same. Strain at maximum stress and strain at break were also measured but were not reported in the available datasheet.

Osteoporosis is a systemic skeletal disease where an increase in bone fragility is due to low bone mass and micro-architectural deterioration of bone tissue, which occur over a long period of time without clinical significance. Currently, Double Energy X-ray Absorption (DEXA) is the gold standard for bone mineral density assessment and the diagnosis of osteoporosis, but the majority of fractures occur in patients who would not be considered at fracture risk based on their Bone Mineral Density (BMD) values. It has long been known that fracture risk depends not only on mass loss, but also on bone architecture, whose alterations are an independent factor of increased fragility. The Bone Elastic Structure Test, BES TEST®, is a recently introduced analysis that assesses bone quality as expressed by the elastic properties of the trabecular micro-architecture from a virtual biopsy of the patient and could be a helpful add-on to densitometry for predicting fragility fractures and patient monitoring. The aim of this study is the comparison of DEXA and BES TEST® ability as 3-year risk estimators in a clinical application. In the CONTROL group, the BSI T-score is significantly different from the femoral DEXA T-score (p = 0.0005). In the FRACTURED group, the BSI T-score is significantly different from both the femoral DEXA T-score (p = 0.0266) and the lumbar DEXA T-score (p = 0.0051). Inter-group t-test statistical analysis (95% significance) shows that the femoral DEXA T-score (neck) of the CONTROL and the FRACTURED groups are not significantly different (p = 0.1478), while the BSI T-score of the CONTROL and the FRACTURED groups highlights a significant difference (p = 0.0001). Despite the small number of subjects, our data seem to confirm that the BSI could be a helpful add-on to densitometry for predicting fragility fractures and patient monitoring.

The social costs of osteoporosis are huge and keep growing because of increased life expectancy. Although a low bone mineral density is considered to be associated with a higher risk of fracture, densitometry alone has been shown to be inadequate to predict a significant number of fractures, hence the need to develop innovative and inexpensive diagnostic methods to be used together with the consolidated systems. The Bone Structure Index is computed using a patented technique that virtually simulates the application of compressive loads on the trabecular structure’s reconstructions obtained from the patient’s digital radiographs. The radiograms are acquired by a hand-held portable x-ray system equipped with a digital sensor. This configuration presents specific advantages but the use of a handheld portable X-ray device requires safety procedures specifically designed to protect the operator and the patient, which are discussed in the present paper.

Due to its building process, the mechanical properties of a 3D-printed object are substantially different from those of the same object, made of the same material, but obtained by a different manufacturing process. Tensile tests were carried out on standard specimens, which were 3D-printed with a Builder Premium™ FDM printer. Three different plastic and composite materials were tested and their stress-strain curves were obtained; significant parameters such as ultimate tensile strength and Young’s modulus were calculated and compared.

Background Pituitary down regulators, aromatase inhibitors tamoxifen and chemotherapeutic drugs, all have a negative impact on bone health in breast cancer patients. Although trabecular bone accounts for only 20% of skeleton mass, bone resistance depends also on the its micro-architecture, or quality, of, in addition to bone density. The BESTEST® is an innovative and inexpensive diagnostic method that gives an indication of the quality of the bone structure: it measures the weight-bearing capacity of the bone structure, evaluated from simulated application of loads on bone structure images acquired by radiograms in the proximal epiphysis of the hand. Results are expressed as BSI_T-score and BSI_Z-score (which refers the results to the average value for the same age) and provide precious add-on information to densitometry. We discuss the preliminary results obtained in female patients undergoing breast cancer treatment. Material and methods 100 Caucasian women, took BESTEST® as follow-up while undergoing oncological treatment. Femoral neck DXA T-score available in a subgroup of 60. 10 patients self-reported an osteoporotic fracture, DXA T-score available for 8. Control population: 200 women, accessing BESTEST® and DXA for screening purposes, 30 self-reporting an osteoporotic fracture. Results Statistics: mean (min, max). NAgeBSI_T-scoreBSI_Z-scoreDXA_T-scorePopulation10061 (33, 88)-1.7 (-3.4, -0.0)-1.3 (-2.6, 0.6)NADXA subgroup (of oncological population)6062 (35, 88)-1.8 (-3.4, -0.1)-1.3 (-2.6, 0.6)-1.6 (-3.2, 0.5)Fractured subgroup1067 (56, 82)-2.4 (-2.9, -1.3)-1.8 (-2.6 -0.1)NAFractured subgroup with DXA868 (60, 82)-2.4 (-2.9, -1.3)-1.8 (-2.6 -0.1)-1.5 (-2.9, 0.1)Control20063 (32, 89)-1.1 (-3.6, 2.9)-0.6 (-3.0, 2.9)-1.9 (-3.7, 1.0) The fractured subgroup exhibits significantly lower BSI T-score than the population (T-test p< 0.0100) and results are similar after BSI Z-score correction for age (T-test p = 0.0300). The BSI T-score of the DXA subgroup is representative of the oncological population undergoing treatment (T-test p=0.8668). As expected, BSI T-score and DXA T-score are not correlated: R2 = 0.0917 in the control and R2 = 0.0294 in the population. The DXA subgroup exhibit significantly lower BSI T-score than the control (T-test p = 0.0002) and similar results are obtained after BSI Z-score correction for age. A lower significance (T-test p = 0.0281) is found for DXA T-score. The 8 fractured oncological patients exhibit significantly lower values of BSI T-score that the oncological population (T-test p = 0.038) and all patients have a BSI T-score indicative of a compromised trabecular structure. DXA T-score values cannot be considered statistically different (T-test p = 0.6744) and results span all possible diagnostic results from high risk to normal. Conclusions Statistical analyses show that bone micro-architecture is indeed affected by oncological treatment and that bone alterations due to oncological treatment are easily detected with BESTEST, especially when associated with fractures. This preliminary study clearly provides a rational background for further, deeper investigations into the use of a new, rapid and safe technique for monitoring the effect of breast and prostate cancers therapies on bone micro-architecture modifications. Citation Format: Cosmi F, Del Conte A, Foltran L, Nicolosi A, Saracchini S. New diagnostic tools for bone health assessment: Perspectives in medical oncology [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-03-08.

Duchenne muscular dystrophy is a lethal genetic disease characterised by progressive degeneration of skeletal muscles induced by deficiency of dystrophin, a cytoskeletal protein expressed in myocytes and in certain neuron populations. The severity of the neurological disorder varies in humans and animal models owing to dysfunction in numerous brain areas, including the hippocampus. Cyclic treatments with high-dose glucocorticoids remain a major pharmacological approach for treating the disease; however, elevated systemic levels of either stress-induced or exogenously administered anti-inflammatory molecules dramatically affect hippocampal activity. In this study, we analysed and compared the response of hippocampal neurons isolated from wild-type and dystrophic mdx mice to acute administration of corticosterone in vitro, without the influence of other glucocorticoid-regulated processes. Our results showed that in neurons of mdx mice, both the genomic and intracellular signalling-mediated responses to corticosterone were affected compared to those in wild-type animals, evoking the characteristic response to detrimental chronic glucocorticoid exposure. Responsiveness to glucocorticoids is, therefore, another function of hippocampal neurons possibly affected by deficiency of Dp427 since embryonic development. Knowing the pivotal role of hippocampus in stress hormone signalling, attention should be paid to the effects that prolonged glucocorticoid treatments may have on this and other brain areas of DMD patients.

Additive manufacturing is gaining greater and greater popularity in recent years: thanks to a dramatic reduction of costs and increasing print quality, more and more people are attracted to 3D printing, even for the production of end-use load-bearing parts. Today, there are no universally accepted norms that guide the engineer through the uncertain task of predicting the mechanical behavior of 3D-printed parts. Even though there are numerous reports and articles in literature regarding this topic, the designer will have to rely mostly on his own mechanical tests. This paper describes the design of an in-house-built machine for 3D-printed material tensile testing. The accuracy of this test-rig has been verified through comparison of results on different 3D-printed specimens: these were realized through fused deposition modelling (FDM) and were divided into four distinct sets, based on the material and their orientation on the buildplate. Some samples were printed in PLA, others in XTCF-20™: a composite material made of a matrix of Amphora™ polymer reinforced with 20% in weight carbon short fibers. PLA samples were printed flat on the buildplate, on one side and standing: this affects directly the orientation of the plastic fibers. Tensile tests were performed both on ours and on a high-end commercial testing machine, following the ISO 527 norm. Maximum stress, strain at maximum stress and Young’s modulus were calculated for each tested specimen: these measures allowed to compare the results of the two testers. Results proved coherent, thus validating the in-house machine, which was realized for a fraction of the cost of an equivalent commercial model.

Additive manufacturing offers several advantages when compared to conventional manufacturing technologies, especially where large scale customization is requested. In this article, a procedure for the design of a fully-customized 3D-printed ankle-foot orthosis (AFO) is described, with reference to a case study regarding a 21-year-old woman with an injured ankle. The first step is the acquisition of the geometrical data from the patient’s foot: this is done using photogrammetry. The second step is the data conversion and import in a CAD modeler; SolidWorks™ is chosen for this purpose. The AFO is modelled parametrically around the foot mesh and optimized in order to resist the predicted mechanical stresses. Finally, the device is 3D-printed on an FDM printer and tested on the patient. An excellent geometrical correspondence between the AFO and the patient’s foot is highlighted: this leads to great comfort and enhances medical functionality. The described procedure can be easily automated, further reducing the lead time and costs of the whole process

Early phase endocrine-expansive breast and prostate cancers are treated with post-operative adjuvant hormonal therapies and chemotherapeutic drugs that have a negative impact on bone heath, blocking estrogen or androgen activity and increasing bone turnover leading to a progressively higher risk of fractures. At present, DXA monitoring of bone loss is widely recommended in prostate and breast cancer patients, but most fractures occur in patients whose DXA result falls outside the osteoporosis ranges, indicating that DXA might not be the elective exam for evaluating the degree of fracture risk in terms of microarchitecture alterations. The recently introduced Bone Structure Index (BSI) gives an indication of the quality of the bone structure. In this work, we discuss the preliminary results obtained in the evaluation of the BSI in female patients undergoing breast cancer treatment

We obtained an extended description of the abnormalities present in the bone structure in a rare inherited skeletal disorders. The 3D reconstructions of the trabecular architecture in the femur, obtained by CT scans, were the starting point for the morphological evaluation and the numerical elastic characterization of two subjects: a subject whose osteopetrosis was corrected by hematopoietic stem cell transplantation several years before and a healthy control. The Bone Structure Index, a novel parameter computed from the planar radiograms of the trabecular structure in the proximal epiphysis of the hand, was also evaluated. Important differences, that were not reported in literature before, were detected in homologous portions of the subjects

Il presente trovato si riferisce ad un procedimento per calcolare un indice rappresentativo di una proprietà di un materiale, ad esempio un materiale di tipo osseo, a partire almeno da un’immagine di un campione di tale materiale. Il trovato si riferisce altresì ad un sistema di rilevazione configurato per agevolare l’operazione di rilevazione dell’immagine del suddetto campione.

Osteoporosis is a silent disease, characterized by a decreasing bone strength, which leads to a progressive increase in fracture risk. As mean average human lifespan is growing, a parallel rise in the rate of osteoporosis is observed. Currently, diagnosis is made on the basis of bone mineral density, which seems to be a poor fracture predictor in about 40-50% of cases, and of clinical risk factors, but the trabecular structure arrangement should be evaluated as well. The BSI (Bone Structure Index) is a new index computed from simulated application of loads on a virtual biopsy of the patient. In this work, we aim to identify the distributions of BSI and of fragility fracture risk factors recognized by the scientific community in a population of over 300 female volunteers.

Sebbene l'osso trabecolare rappresenti solo il 20% dello scheletro, la resistenza dell’osso è fortemente influenzata, oltre che dalla densità, anche dalla micro-architettura della struttura trabecolare. Un metodo diagnostico innovativo di recente introduzione, BESTEST®, mediante il BSI (Bone Structure Index) misura la risposta elastica alle sollecitazioni da parte della struttura ossea, ricavata da simulazioni di carico condotte con metodi ingegneristici su una biopsia virtuale del paziente, ottenuta da radiogrammi planari dell'epifisi prossimale della mano. I risultati dell’esame sono espressi in termini statistici, BSI_T-score e BSI_Z-score, di significato analogo ma non correlati a quelli utilizzati in densitometria. È ben noto che i regolatori ipofisari, gli inibitori dell'aromatasi e il tamoxifene nelle donne in pre-menopausa e i chemioterapici hanno tutti un impatto negativo sulla salute delle ossa poiché, bloccando l'attività degli estrogeni o degli androgeni, aumentano il turnover osseo portando ad un rischio crescente di fratture. L'incidenza globale del rischio di fratture nei pazienti in trattamento ormonale per carcinoma mammario varia dall'1,37% all'11%. In questo lavoro, vengono discussi i risultati preliminari ottenuti nella valutazione del BSI_T-score in 100 pazienti di sesso femminile sottoposte a trattamento per carcinoma del seno. I risultati dimostrano che la micro-architettura ossea è effettivamente influenzata dal trattamento oncologico e che il BESTEST® può fornire un prezioso aiuto alla densitometria nella valutazione di queste alterazioni, specialmente quando associate a fratture. Questo studio preliminare fornisce inoltre una base razionale per ulteriori e più approfondite indagini sull'uso di questa nuova tecnica, rapida e sicura, per monitorare l'effetto delle terapie contro il cancro della mammella sulle alterazioni della micro-architettura ossea.

The aim of this work is to evaluate the fibre length distribution in a polyamide reinforced by short glass fibre. The fibre length and the fibre orientation distributions strongly influence the mechanical properties of short fibre reinforced composites. The sample investigated is a 30GFPA6 (polyamide-6 reinforced by 30 % by weight glass fibre), extracted from an injection-moulded plate. The digital reconstruction of the three-dimensional structure of the sample was obtained by synchrotron radiation micro-computed tomography (micro-CT), a high spatial resolution non-destructive technique. One global and one local method have been tested for the automatic evaluation of the fibre length distribution in our sample. The global method is based on the mean fibre length distribution computed from the Star Length Distribution (SLD), a morphological parameter. The local method is based on a 3D skeletonize function. The results are discussed in the light of the experimental data available in literature.

The micro-tomographic technique represents an important tool for the analysis of the internal structure in short-fibre-reinforced polymers samples. For the investigation of damage mechanisms, detection of the micro-voids within the matrix can be facilitated by applying a tensile load in-situ during the scan. The investigations here described started from two micro-CT acquisitions, at different strain levels, of the same PA6.6GF10 sample. An original procedure for micro-voids identification is proposed, based on the statistical elaboration of the matrix grey-tone range. In order to validate the suggested procedure beyond visual inspection, an independent method based on an optimisation approach, which puts to use the two available micro-tomographic sets, was developed and applied. The effect of the tensile load, which can induce a progression of the damage within the specimen, was investigated, and the relations among strain, fibre distribution and micro-voids volumetric fraction were studied. Our findings point out that the mechanisms of damage progression, even under static loading as in this case, appear to be more complex than those related to the fibre-density-induced stress concentrations alone and require further investigation.

Osteoarthritis (OA) is a degenerative joint disease that occurs mostly in the knee and in the hip. It is expected that more than 20% of the population over the age of 60 in Europe and in the United States will show signs and symptoms associated with OA, and that one-third of OA patients will experience disability and immobilization, hence the motivation for this research aimed at achieving new insights into the bone structure alterations induced by this disease. In an original approach, the 3D reconstructions obtained by high-resolution X-ray micro-CT were the starting point for: i) a morphological examination and 2) structural 3D analyses by numerical simulation of the bone architectures behavior, thus providing an extended description of the changes in osteoarthritic bone as disease progress. This paper presents the first results obtained by the combination of morphological and structural 3D analyses from on high-resolution micro-CT reconstructions of trabecular bone in early and late stage hip OA.

Densitometry is considered to be the gold standard in bone quality assessment. However, since its introduction, the medical community has been aware that mineral density is only one of the factors that influence the bone risk of fracture, which also depends on the bone's trabecular arrangement and, in particular, on the trabecular architecture's load bearing capabilities. At the University of Trieste, in recent years, a test has been developed that simulates the application of compressive loads on trabecular architecture's reconstructions extracted from digital radiographs. In this work, the test is described, and the results obtained by applying the appraisal in a particular case of severe osteoporosis of the hand, complicating a Complex Regional Pain Syndrome (CRPS) type II, are presented. The test was able to quantify the pathological alterations of bone micro-architecture by means of a Structural Index (SI), which was absolutely significant and relevant to the clinical situation. Important research and clinical opportunities of application of the test include accurate evaluation of osteoporotic bone diseases, careful clinical follow-up and monitoring of responses to therapeutic approaches, and, prospectively, reliable quantification of biological damage (forensic field).

The development of predictive models for fatigue behavior of materials is closely related to a quantitative assessment of damage nucleation and propagation phenomena. Conventional methods used for this purpose, such as microscope observations, conventional radiographs, ultrasonography techniques, either are destructive or do not reach an adequate resolution. Imaging techniques using synchrotron radiation, and in particular X-ray micro-computed tomography (micro-CT), however, combine the advantages of a non-destructive technique with a high spatial resolution. In this paper, damage evolution in samples extracted from PA6.6GF35 specimens subjected to fatigue tests interrupted at different stages of fatigue life is investigated by means of synchrotron radiation micro-CT. Although preliminary, our results suggest that the application of this technique for micro-voids detection within the glass short fibre polyamide reinforced samples offers unique possibilities of investigating the micro-scale internal structure of the samples but, at the same time, presents several criticalities at different stages of the analyses, ranging from specimen size to set-up configuration and threshold selection. A frank discussion of the critical issues encountered during the analyses supplements the presentation in an effort to help defining general guidelines for future developments in this field.

Pathological polymers of Z alpha1-AT can be secreted from cells through the canonical secretory pathway http://ow.ly/WHxZh

Osteoporosis is a very common disease in which the bones become weak and easily break. Besides the serious impact on a person’s health and quality of life, osteoporosis results in important costs for society. The current diagnosis considers the bone quantity, as evaluated by bone mineral density assessments, and the clinical risk factors, but cannot take into account the bone quality, defined as the structural soundness of the trabecular arrangement. An approach based on the numerical modeling of the behavior of bone architectures, acquired by planar radiograms in the proximal phalanges of the non-dominant hand, has been developed at the University of Trieste. The Bone Structure Index, BSI, summarizes the simulations results for the purpose of bone quality ranking in the clinical evaluation. In this work, we discuss the preliminary design of a portable low dose x-ray scanner intended to be used as a low cost, user-friendly device for imaging the trabecular pattern and for providing a radiogram suitable for BSI evaluation. As an example, two cases in which the chosen device is used to evaluate the BSI are also reported.

In short glass fibre reinforced polymers parts obtained by injection moulding, processing conditions produce complex orientation patterns that influence the mechanical properties of the component. In this work, the problem of whether a morphological description can be predictive of the elastic behaviour of these materials is addressed, with particular reference to the shell and core zones identified in a PA6-GF 30 sample. Morphological parameters considered include fibre volume fraction, Mean Intercept Length (MIL) fabric tensor eigenvalues and principal directions. Apparent elastic moduli values in different sites within the sample were computed by simulations using a numerical model based on the Cell Method. Both morphological and numerical methods were able to capture the principal directions of anisotropy and the differences between shell and core and among the volumes of interest within each region. Even if the fabric tensor, normalised, eigenvalues did not show a significant correlation to the apparent elastic moduli, approximately 92% of stiffness components variance could be accounted for by changes in MIL eigenvalues once normalised values were used for elastic moduli as well.

The elastic moduli of short fibre polyamide reinforced with different contents of glass fibres were computed by means of a numerical model. The analyses were based on the reconstructions of the internal fibre structure obtained by micro tomography using synchrotron light. The reconstructed volumes were used in a Cell Method micro-mechanical model in order to simulate the local tensile behaviour of the specimens.

The combined effect of notches and fibre orientation on static and fatigue strength of short glass fibre reinforced polyamide 6 was studied using notched specimens that, by proper design of the mould, could be injection moulded through gates of two different sizes and locations. The results showed that the values of the tensile and fatigue notch factors for a particular geometry were strongly influenced by varying the way specimens were injected. A new experimental method was applied to investigate whether the observed differences in mechanical behaviour of specimens having the same geometry were caused by different fibre orientation distributions. Synchrotron light micro- tomography allowed for visualisation of local fibre orientation at notches and the obtained images of the internal structure of the samples were subsequently analyzed by a global morphological parameter, the Mean Intercept Length. Results were also discussed in light of the full displacement field measured by Digital Image Correlation.

The fibre orientation distribution in a material sample extracted from an injection moulded plate, displaying the commonly encountered layered shell-core-shell structure, was analyzed. Starting from a micro tomography reconstruction of the sample, instead of trying to isolate each single fibre and measuring its geometrical properties, we derived the components of a fabric tensor from the evaluation of a global anisotropy parameter, the mean intercept length MIL. This parameter, commonly employed for the analysis of biological and geological structures, proved to be an efficient tool for the analysis of the structure of short fibre reinforced composites. The local variations of the degree of anisotropy (ratio of the maximum and minimum eigenvalues of the fabric tensor) from the shell to the core layers of the injection moulded plate could be captured and information about the local average fibre orientation angle was also obtained.

In this work we analysed a sample of short fibre reinforced polyamide extracted from an injection moulded plate. We derived local values of the elastic constants by two different numerical methods, one based on simulation and one based on the reconstruction of the sample's microstructure by micro - CT. Results were compared in terms of moduli of elasticity, assuming an orthotropic material model. Fibre orientation was first simulated by process simulation and results were checked against experimental data obtained by the optical section method. Then, fibre orientation data were used for micro-mechanical modelling of the elastic behaviour by means of mean field homogenisation tools. The experimentally based approach was based on micro computed tomography reconstructions of the inner structure of samples extracted from the injection moulded plate. Using numerical models based on the Cell Method, the elastic behaviour of the reconstructed volume was simulated and results were compared with analytical models based on process simulations and homogenization.

The contact mechanics of two metal-on-metal (MOM) total hip prostheses was studied by means of the finite element method (FEM). The purpose of the work was to compare two total hip replacements (Durom™ and Metasul™) with regard to the amount of wear debris released. Wear on the bearing surfaces was evaluated following Reye hypotheses from the pressure distribution, computed by means of three-dimensional FEM models; an approximate analytical model based on Hertz contact theory has also been developed and discussed. The results show that in the dry friction condition the Durom™ joint releases almost twice as much wear volume as produced by the Metasul™ joint. Therefore, while Durom™ implants can improve hip stability by increasing the prosthetic impingement-free range of motion (PIF-ROM), Metasul™ prostheses can be a valuable solution whenever wear represents a critical choice factor.

One of the most important alterations that occur in man and experimental animals during spaceflight concerns the skeletal system, and entails important bone loss and degradation of mechanical properties. In the present work we investigate ex vivo the long-term effects of weightlessness (simulated microgravity) on bone tissue, by comparing the mesoscale structural properties of weight-bearing rat tibial epiphyseal cancellous structures of healthy animals (ground controls) with those of identical bone explants maintained ex vivo in the Rotary Cell Culture System (RCCS) bioreactor, used to model, on ground, microgravity conditions. Bone structures were reconstructed by synchrotron radiation micro-CT, morphometric analyses were performed, and the apparent elastic properties were computed by means of a numerical model based on the Cell Method. Two novel results were achieved in this study. First of all, the skeletal modifications found in bone explants after 3-4 weeks of culture in the RCCS bioreactor are in perfect agreement with those observed in vivo after a long-term spaceflight (Mice Drawer System mission, 2009), thus confirming the relevance of our model in reproducing the effects of microgravity on whole bone tissue. Secondly, but not less importantly, our study points out that the degradation in bone structural performance (apparent mechanical properties) must be considered in order to achieve an accurate representation of trabecular bone modifications not only in osteoporotic bone diseases, but also in the microgravity-induced bone alterations. In conclusion, our findings, by proving that the association of the RCCS bioreactor-based culture method, used to model microgravity conditions, with numerical simulations able to quantify bone quality, represents the first ground-based reliable model for investigating, ex vivo, some of the spaceflight effects on bone tissue, and open new perspectives to basic research and clinical applications.

The fatigue behavior of a short fibre reinforced polyamide was investigated using small specimens, as part of a larger study of the fatigue damage phenomena in this material using micro computed tomography techniques. These techniques require very small specimens, smaller than the usual specimens commonly used in industry. Therefore, preliminary investigations were conducted on the effect of the shape of the specimens on the tensile and fatigue properties. Standard small ASTM D 1822 specimens and larger ISO 527 specimens were used. The results are discussed in the light of cyclic behavior and of the evolution of the surface temperature during fatigue tests.

In recent years, micro-CT has proved to be a very effective and reliable method for assessing the fibre structure in SFRP. More recently, efforts have been made in order to apply the technique for studying the damage accumulation processes in these materials. Among other issues, the micro-CT set-up requires samples of narrow gauge section allowing to concentrate damage. The aim of the experimental characterization presented below is threefold: • a comparison of the mechanical properties of two standard geometries of PA6.6GF10, the smaller ASTM D1822 (9.6 mm2 section, constant curvature) and the ISO 527-1A (40 mm2 constant section), used in the previous works; • a collection of data during interrupted fatigue tests on the ASTM samples, for later use in the damage accumulation investigation; • a fatigue thermal analysis, possible only on ISO samples due to their larger dimensions.

Hospitals, thanks to a constant evolution of health technology, have the task to improve reliability of services and to preserve patients and workers from malfunctions, both mechanical and human. To this aim, recently, reliability tools have started to be adopted in the health field. In its constant pursuit for a better health service, in 2012 the Technology Assessment structure at the Azienda Ospedaliero-Universitaria of Trieste started an interdisciplinary activity of verification of malfunctions occurring in the dialysis and nephrology unit.

This article describes the significance in human, scientific, and technical terms of the first experiment in telerobotic surgery carried out between the NASA Jet Propulsion Laboratory in Pasadena, California, and the Telerobotics Laboratory of the Politecnico di Milano on 7 July 1993. An Italian robot in the Telerobotics Laboratory was remotely controlled by an Italian surgeon in the United States. The robot's task was to perform a surgical operation on a model containing a pig's organs, involving execution of a biopsy, aspi ration of organic material, and two incisions in preparation of laparoscopy. Transmission was effected by means of a double satellite link, with three transceiver stations: one in Italy, one close to New York, and one in Pasadena, and two geostation ary satellites, the first over the Atlantic and the second over the United States. The route length of the signals was 150,000 km in each direction, and the two centers are 10,000 km apart.

The fibre orientation distribution in a material sample of short fibre reinforced polyamide extracted from an injection moulded notched plate was analysed using two different methods, one based on micro-computed tomography and the Mean Intercept Length concept and the other based on the classical optical section method. The two methods were compared in terms of the preferred fibre orientation at a chosen position, and the agreement was found to be excellent provided the correct section plane was chosen for the optical method. The optical method was applied to different section planes to ascertain the best choice. Comparisons with the optical method, which can provide the full fibre orientation distribution, confirm that the analysis based on the MIL concept is capable of capturing important information about the fibre orientation.

The mechanical properties of components made of short fibre reinforced composites, generally obtained by injection moulding, are strongly linked to fibre orientation. Therefore, it is of great importance to be able to verify the results of manufacturing process simulations obtained by commercial software. From the experimental point of view, the definition of carbon short fibre structure within a polymeric matrix in a micro-tomography is a non-trivial task, as the X-rays absorption properties of the two phases are very similar. This paper presents how this problem was overcome by using phase contrast imaging techniques. High resolution fibre structure reconstructions could therefore be obtained. The reconstruction of a large sample volume by overlapping of successive tomographies was also discussed. Moreover, this work shows that the anisotropy identification techniques based on morphological parameters, previously introduced by some of the Authors for short glass fibre reinforced polymers, can also be adopted for fibre arrangement identification in this type of materials.

In future years, fuel cells are expected to represent a promising technology as a source of heat and electricity in buildings and of electrical power for vehicles, since fossil fuels are exhausting and significantly degrade air quality. It is well known that, when exposed to a hydrogen environment, hydrogen embrittlerment may affect materials such as iron and steel. But these are not the only materials that are used for hydrogen equipment. In particular, the rubber materials used for O–rings that seal high pressure hydrogen gas equipment show problems of internal fracture, called blister fracture, when the gas is rapidly decompressed. As many different kinds of fillers can be used, in this work we started to investigate the influence of the type of filler on the rubber composites structure, by means of X-ray diffraction measurements performed at the Elettra synchrotron radiation facility in Trieste. In this preliminary study, three kinds of samples were analyzed before and after exposure to hydrogen: Sulphur vulcanized EPDM, Peroxide vulcanized EPDM and Sulphur vulcanized NBR. While Peroxide vulcanized samples did not show significant differences in the diffraction pattern, changes could be detected in the cristalline form of Sulfure vulcanized rubber.

Possible solutions for damage evaluation by micro-CT in SFRP

The fatigue behaviour of injection moulded short fibre reinforced polymers depends upon fibre orientation, as shown in experiments conducted with notched specimens injected through different injection gates. The different fatigue behaviour is mainly related to the different local elastic properties, as determined by the different fibre orientation patterns, resulting into different strain distributions. In order to quantify the relationship between fibre orientation and elastic constants, the Cell Method was applied to volumes extracted from the specimens, reconstructed by micro-tomography.