1,473 research outputs found
MRI-guided focused ultrasound surgery in musculoskeletal diseases: the hot topics
MRI-guided focused ultrasound surgery (MRgFUS) is a minimally invasive treatment guided by the most sophisticated imaging tool available in today's clinical practice. Both the imaging and therapeutic sides of the equipment are based on non-ionizing energy. This technique is a very promising option as potential treatment for several pathologies, including musculoskeletal (MSK) disorders. Apart from clinical applications, MRgFUS technology is the result of long, heavy and cumulative efforts exploring the effects of ultrasound on biological tissues and function, the generation of focused ultrasound and treatment monitoring by MRI. The aim of this article is to give an updated overview on a "new" interventional technique and on its applications for MSK and allied sciences
Modeling and Control of a novel Variable Stiffness three DoF Wrist
This paper presents a novel design for a Variable Stiffness 3 DoF actuated
wrist to improve task adaptability and safety during interactions with people
and objects. The proposed design employs a hybrid serial-parallel configuration
to achieve a 3 DoF wrist joint which can actively and continuously vary its
overall stiffness thanks to the redundant elastic actuation system, using only
four motors. Its stiffness control principle is similar to human muscular
impedance regulation, with the shape of the stiffness ellipsoid mostly
depending on posture, while the elastic cocontraction modulates its overall
size. The employed mechanical configuration achieves a compact and lightweight
device that, thanks to its anthropomorphous characteristics, could be suitable
for prostheses and humanoid robots.
After introducing the design concept of the device, this work provides
methods to estimate the posture of the wrist by using joint angle measurements
and to modulate its stiffness. Thereafter, this paper describes the first
physical implementation of the presented design, detailing the mechanical
prototype and electronic hardware, the control architecture, and the associated
firmware. The reported experimental results show the potential of the proposed
device while highlighting some limitations. To conclude, we show the motion and
stiffness behavior of the device with some qualitative experiments.Comment: 13 pages + appendix (2 pages), 19 figures, submitted to IJR
Microglia-derived microvesicles affect microglia phenotype in glioma
Extracellular-released vesicles (EVs), such as microvesicles (MV) and exosomes (Exo)
provide a new type of inter-cellular communication, directly transferring a ready to use
box of information, consisting of proteins, lipids and nucleic acids. In the nervous
system, EVs participate to neuron-glial cross-talk, a bidirectional communication
important to preserve brain homeostasis and, when dysfunctional, involved in several
CNS diseases. We investigated whether microglia-derived EVs could be used to transfer
a protective phenotype to dysfunctional microglia in the context of a brain tumor.
When MV, isolated from microglia stimulated with LPS/IFNg were brain injected in
glioma-bearing mice, we observed a phenotype switch of tumor associated myeloid
cells (TAMs) and a reduction of tumor size. Our findings indicate that the MV cargo,
which contains upregulated transcripts for several inflammation-related genes, can
transfer information in the brain of glioma bearing mice modifying microglial gene
expression, reducing neuronal death and glioma invasion, thus promoting the recovery
of brain homeostasis
The Role of ABO Blood Type in Thrombosis Scoring Systems
In addition to their major role in transfusion medicine, there is increasing evidence that ABO blood group antigens (complex carbohydrate molecules widely expressed on the surface of red blood cells and several other cell types) are implicated in the development of a wide array of pathologic conditions. In particular, intense research has been dedicated over the last 50 years to the study of the association between non-O blood type and the risk of developing cardiovascular disorders. Several pathways have been hypothesized to explain this relationship, the most reasonable implying the influence of the ABO blood group on circulating plasma levels of von Willebrand factor, factor VIII, and several inflammatory cytokines. This narrative review summarizes the current knowledge on the role of ABO antigens in both venous and arterial thromboses, focusing on their association with clinical scoring systems evaluating thrombotic risk
The management of a blood donor bitten by a snake
The worldwide burden of snakebite is high and venomous snakes are found in many regions of the world and are a threat to public health. In Italy, for instance, viper bites are an infrequent but not negligible event. Although people who have been bitten by a snake rarely wish to donate blood within a "short" time, it is however important to evaluate their eligibility to donate blood or blood components as their donation could be a problem for donor management, especially if a specific policy is not in place. The aim of this manuscript is to summarise the worldwide existing donor deferral policy for snakebites and to provide some indications in order to facilitate decision-making and to guarantee maximum safety for the donors as well as for the recipients
Fatty images of the heart: spectrum of normal and pathological findings at computed tomography and cardiac magnetic resonance imaging.
Ectopic cardiac fatty images are not rarely detected incidentally at computed tomography and cardiac magnetic resonance, either in exams focused on the heart as in general thoracic imaging evaluations. A correct interpretation of these findings is essential in order to recognize their normal or pathological meaning, focusing on the eventually associated clinical implications. The development of techniques such as computed tomography and cardiac magnetic resonance allowed a detailed detection and evaluation of adipose tissue within the heart. This pictorial review illustrates the most common characteristics of cardiac fatty images at computed tomography and cardiac magnetic resonance, in a spectrum of normal and pathological conditions ranging from physiological adipose images to diseases presenting with cardiac fatty foci. Physiologic intramyocardial adipose tissue may normally be present in healthy adults, being not related to cardiac affections and without any clinical consequence. However cardiac fatty images may also be the expression of various diseases, comprehending arrhythmogenic right ventricular dysplasia, post-myocardial infarction lipomatous metaplasia, dilated cardiomyopathy and lipomatous hypertrophy of the inter-atrial septum. Fatty neoplasms of the heart as lipoma and liposarcoma are also described
Epigenetics Modifications and Therapeutic Prospects in Human Thyroid Cancer
At present no successful treatment is available for advanced thyroid cancer, which comprises poorly differentiated, anaplastic, and metastatic or recurrent differentiated thyroid cancer not responding to radioiodine. In the last few years, biologically targeted therapies for advanced thyroid carcinomas have been proposed on the basis of the recognition of key oncogenic mutations. Although the results of several phase II trials look promising, none of the patients treated had a complete response, and only a minority of them had a partial response, suggesting that the treatment is, at best, effective in stabilizing patients with progressive disease. “Epigenetic” refers to the study of heritable changes in gene expression that occur without any alteration in the primary DNA sequence. The epigenetic processes establish and maintain the global and local chromatin states that determine gene expression. Epigenetic abnormalities are present in almost all cancers and, together with genetic changes, drive tumor progression. Various genes involved in the control of cell proliferation and invasion (p16INK4A, RASSF1A, PTEN, Rap1GAP, TIMP3, DAPK, RARβ2, E-cadherin, and CITED1) as well as genes specific of thyroid differentiation (Na+/I− symport, TSH receptor, pendrin, SL5A8, and TTF-1) present aberrant methylation in thyroid cancer. This review deals with the most frequent epigenetic alterations in thyroid cancer and focuses on epigenetic therapy, whose goal is to target the chromatin in rapidly dividing tumor cells and potentially restore normal cell functions. Experimental data and clinical trials, especially using deacetylase inhibitors and demethylating agents, are discussed
Human T-lymphotropic virus and transfusion safety. Does one size fit all?
Human T-cell leukemia viruses (HTLV-1 and HTLV-2) are associated with a variety of human diseases, including some severe ones. Transfusion transmission of HTLV
through cellular blood components is undeniable. HTLV screening of blood donations became mandatory in different countries to improve the safety of blood
supplies. In Japan and Europe, most HTLV-infected donors are HTLV-1 positive, whereas in the United States a higher prevalence of HTLV-2 is reported. Many
industrialized countries have also introduced universal leukoreduction of blood components, and pathogen inactivation technologies might be another effective
preventive strategy, especially if and when generalized to all blood cellular products. Considering all measures available to minimize HTLV blood transmission, the
question is what would be the most suitable and costeffective strategy to ensure a high level of blood safety regarding these viruses, considering that there is no
solution that can be deemed optimal for all countries
Soft Robotics: Design for Simplicity, Performance, and Robustness of Robots for Interaction with Humans.
This thesis deals with the design possibilities concerning the next generation of advanced Robots. Aim of the work is to study, analyse and realise artificial systems that are essentially simple, performing and robust and can live and coexist with humans. The main design guideline followed in doing so is the Soft Robotics Approach, that implies the design of systems with intrinsic mechanical compliance in their architecture. The first part of the thesis addresses design of new soft robotics actuators, or robotic muscles. At the beginning are provided information about what a robotic muscle is and what is needed to realise it. A possible classification of these systems is analysed and some criteria useful for their comparison are explained. After, a set of functional specifications and parameters is identified and defined, to characterise a specific subset of this kind of actuators, called Variable Stiffness Actuators. The selected parameters converge in a data-sheet that easily defines performance and abilities of the robotic system. A complete strategy for the design and realisation of this kind of system is provided, which takes into account their me- chanical morphology and architecture. As consequence of this, some new actuators are developed, validated and employed in the execution of complex experimental tasks. In particular the actuator VSA-Cube and its add-on, a Variable Damper, are developed as the main com- ponents of a robotics low-cost platform, called VSA-CubeBot, that
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can be used as an exploratory platform for multi degrees of freedom experiments. Experimental validations and mathematical models of the system employed in multi degrees of freedom tasks (bimanual as- sembly and drawing on an uneven surface), are reported.
The second part of the thesis is about the design of multi fingered hands for robots. In this part of the work the Pisa-IIT SoftHand is introduced. It is a novel robot hand prototype designed with the purpose of being as easily usable, robust and simple as an industrial gripper, while exhibiting a level of grasping versatility and an aspect comparable to that of the human hand. In the thesis the main theo- retical tool used to enable such simplification, i.e. the neuroscience– based notion of soft synergies, are briefly reviewed. The approach proposed rests on ideas coming from underactuated hand design. A synthesis method to realize a desired set of soft synergies through the principled design of adaptive underactuated mechanisms, which is called the method of adaptive synergies, is discussed. This ap- proach leads to the design of hands accommodating in principle an arbitrary number of soft synergies, as demonstrated in grasping and manipulation simulations and experiments with a prototype. As a particular instance of application of the method of adaptive syner- gies, the Pisa–IIT SoftHand is then described in detail. The design and implementation of the prototype hand are shown and its effec- tiveness demonstrated through grasping experiments. Finally, control of the Pisa/IIT Hand is considered. Few different control strategies are adopted, including an experimental setup with the use of surface Electromyographic signals
Bologna Process and Expenditure on Higher Education: A Convergence Analysis of the EU-15
The Bologna Process represents a major example of a political and institutional convergence among Higher Education (HE) policies across European countries. The main fields which are explicitly targeted by such convergence process are: curricula structure, mutual recognition of academic degrees, evaluation procedures. The aim of this work is to evaluate whether it is possible to detect an influence of the Bologna Process on financial resources invested in higher education institutions among the EU-15 countries. We analyse the financial data of HE expenditure in the period 1998-2004 (as the Bologna Declaration was set out in 1998) and, specifically, after the wide implementation of changes in curricula structure in many countries of EU-15 (after 2001). Our approach uses two different techniques: (1) regression models - considering both fixed-effects and random-effects - were used to individuate an eventual “Bologna” effect; (2) then, traditional convergence models (sigma and beta convergence) were employed to analyse this effect in more detail, more specifically to test whether the HE expenditure is converging or diverging in recent years. Our findings suggest that the Bologna Process has had a positive influence on the trend of “expenditure per student” convergence across the EU-15 countries. The estimated speed of convergence is still quite low, and this fact supports a claim for more emphasis on the role of private funding and cost-sharing in terms of European-level policies. However, the EU-15 countries’ different traditions and different socio-economic characteristics are strongly affecting this process, so that the European convergence is towards different steady-levels
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