352 research outputs found
A nanostructured look of collagen apatite porosity into human mineralized collagen fibril
Bone tissue is a hierarchical material characterized at nanoscale by the mineralized collagen fibril, a recurring structure mainly composed of apatite minerals, collagen and water. Bone nanostructure has a fundamental role in determining the mechanical behavior of the tissue and its mass transport properties. Diffusion phenomenon allows to maintain an adequate supply of metabolites in the mechanisms of bone remodeling, adaptation and repair. Several analytical and computational models have been developed to analyze and predict bone tissue behavior. However, the fine replication of the natural tissue still represents a challenge. Insights on the structural organization at nanoscale and on the influence of apatite mineral crystals on the diffusion coefficient lead to outline the functional conditions for the development of biomimetic strategies for bone tissue engineering. Thorough understanding of bone nanostructure is essential to improve longevity of bioscaffolds and to decrease the risk of failure by controlling their mechanical and biological performance
BACCIO BALDINI (1517-1589), PROTOMEDICO ALLA CORTE MEDICEA TRA UMANESIMO E SPERIMENTALISMO
The article aims to shed light on some particular aspects of the activity and the scientific thought of Baccio Baldini, Director of the Laurentian Library and Court physician of the Medici family in Florence. The analysis of his work as a humanist and the recovery of some unpublished documents enable to define the figure of Baldini as a paradigmatic example of the court physicians of modern age in Italy, highlighting the complementarity between humanism and experimentalism in the Renaissance medicine
Microcorrosion Casting in Normal and Pathological Biliary Tree Morphology
The organization of the intrahepatic biliary tree was studied in three dimensions by scanning electron microscopic (SEM) corrosion casts, in normal and cholestatic rat liver.
In the normal liver the observation revealed the features of the biliary passages from the bile canaliculi to the canaliculo-ductular junction, to the ductules and the bile ducts, confirming previous SEM observations.
In cholestatic liver, the modifications and the proliferation of bile ductules appear clearly.
Resin flow from canalicular to sinusoidal network was never observed.
The method was found to be very useful in the evaluation of the architecture of the intrahepatic biliary tree, under normal as well as under pathological conditions
A MATLAB app to assess, compare and validate new methods against their benchmarks
Emerging technologies for physiological signals and data collection enable the monitoring of patient health and well-being in real-life settings. This requires novel methods and tools to compare the validity of this kind of information with that acquired in controlled environments using more costly and sophisticated technologies. In this paper, we describe a method and a MATLAB tool that relies on a standard sequence of statistical tests to compare features obtained using novel techniques with those acquired by means of benchmark procedures. After introducing the key steps of the proposed statistical analysis method, this paper describes its implementation in a MATLAB app, developed to support researchers in testing the extent to which a set of features, captured with a new methodology, can be considered a valid surrogate of that acquired employing gold standard techniques. An example of the application of the tool is provided in order to validate the method and illustrate the graphical user interface (GUI). The app development in MATLAB aims to improve its accessibility, foster its rapid adoption among the scientific community and its scalability into wider MATLAB tools
Restablecimiento de una nueva normalidad biomecánica en las graves deformidades de la rodilla
En las graves alteraciones morfo-estructurales de la rodilla, con inestabilidad en varusvalgus,
las prótesis vinculadas a bisagra simple, tendían a fallar. El presente trabajo se
propone evidenciar que, en tales situaciones, la prótesis vinculada a rotación representa la
solución más idónea para el restablecimiento de una nueva normalidad. 18 pacientes (13
mujeres y 5 hombres) con edad media de 68 años han sido sometidos a intervención para
colocar prótesis de rodilla. Ha sido utilizado el implante Endo-Model® de Waldemar Link®,
prótesis vinculada a rotación. El follow-up medio es de 19 meses con controles a 2, 3, 6 y
12 meses y después anuales. Los resultados han sido: óptimo para 17 pacientes y bueno
para 1 paciente, en el cual se ha verificado la ruptura post-operatoria del tendón
cuadricipital. Nuestra casuística muestra resultados comparables a los de otros autores. No
hemos tenido movilizaciones asépticas o sépticas, ni complicaciones médicas intraoperatorias
y post-operatorias. Consideramos que, en presencia de la correcta indicación
clínica, la utilización de la prótesis vinculada a rotación es preferible a la de deslizamiento
porque disminuye el riesgo de una movilización precoz del implante y del desgaste anormal
de los componentes protésicos, restableciendo una nueva normalidad biomecánica.Peer Reviewe
Is medical device regulatory compliance growing as fast as extended reality to avoid misunderstandings in the future?
Purpose: European Extended Reality (XR) industry is expected to significantly increase by 2025 with an extreme impact on the Healthcare scenario. Considering that the transition period for the Medical Device Regulation 2017/745 (MDR 2017/745) will end in May 2024, purpose of this study is to assess whether the Medical Device Regulatory Compliance is ready to cope with the inclusion of XR and its possible social and economic impact in the world of medical device software (MDSW). Methods: XR publications patterns were evaluated since MDR 2017/745 release on different databases. European normative about MDSW are consulted, followed by the European Database of Medical Devices (EUDAMED). Results: The number of publications on XR have increased since 2017 and healthcare is the third highest-impacted subject area. Specific classes for software have been introduces in the European Nomenclature of Medical Devices (EMDN) and some XR applications have already been registered in EUDAMED classified as MDSW. Conclusions: XR will become intrinsic in everyday medical protocol and guidelines. The establishment of the IEEE Virtual Reality and Augmented Reality Working Group and the statement of VR for remoting surgery as a MDSW in MDCG 2019-11 are demonstration of the necessity of MD regulatory compliance in being able to keep up with the upcoming XR technologies. The Authors agree that the competent authorities should consider intervening in the European Regulative Compliance to cope with the revolution of Phygital in Healthcare and to regulate procedures involving the use of XR in medicine preventing future misunderstanding and criticalities especially for high risk situations
Diagnostic value of presepsin for bacterial infection in cirrhosis: a pilot study
Introduction: Presepsin (or sCD14) has been identified as a protein whose levels increase specifically in the blood of patients with bacterial infections. In this study, we evaluated the clinical performance of sCD14 and its usefulness in the early diagnosis of bacterial infection in decompensated cirrhotic patients. Materials: Seventy patients were enrolled in this study. The mean age of patients was 49.5 years, and 21 were women and 49 men. The heparinized whole blood for the PATHFAST test was used in the evaluation of bacterial infection (T0). The test was repeated after 48 hours (T1); at 96 hours (T2); at 144 hours (T3); then at 15 days (T4) to monitor the clinical responses to therapeutic interventions. Results: Forty-nine patients tested positive for sCD14. The mean sCD14 level was 1854 ± 1744 pg/mL. Microbiological findings confirmed the presence of bacterial infections within 84 ± 4.8 h from enrollment in all 49 positive patients. Thirty-eight patients were considered responders to empirical antibiotic therapy with a decrease of presepsin at the different time points, while an increased level of sCD14 was highlighted in 11 patients. When the test was performed, 45% of the patients showed no signs or symptoms of bacterial infection. At 30 days of follow-up 43 patients survived, and 6 patients died from septic shock. Conclusions: The PATHFAST test highlighted the presence of infection in a very short time (15 minutes), and the presepsin could be considered an early biomarker in patients with cirrhosis. A greater number of patients are necessary to confirm these data
Modular versus monoblock stem in revision total hip arthroplasty: a systematic review and meta-analysis
Background: Total hip arthroplasty (THA) is estimated to grow in the following decades with a consequent increase of THA revisions (rTHA). This systematic review and meta-analysis aims to compare modular and monoblock stem in rTHA surgery, focusing on clinical and radiological outcomes and complication rates. Methods: A literature search was performed using the following search strategy: ((Modular stem) OR (monolithic stem)) AND (hip review) on PubMed, Scopus, and Cochrane. Randomized controlled trials (RCTs) and observational studies (OS) compared clinical and radiological outcomes, and complication rates for monoblock and modular revision femoral stem were included. The risk of bias was assessed through the Methodological Index for Non-Randomized Studies (MINORS) score. The Review Manager (RevMan) software was used for the meta-analysis. The rate of complications was assessed using odds ratio (OR) with 95% confidence intervals (CIs). Results: The authors included 11 OS and one RCT with 3,671 participants (mean age: 68.4 years old). The mean follow-up was 46.9 months. There was no prevalence of subsidence for one type of stem. Mean subsidence was from 0.92 to 10 mm for modular stem and from 1 to 15 mm for monoblock stem. Postoperative Harris Hip Score (HHS) showed better results with modular stems without statistical significance [mean difference (MD) =1.32; 95% CI: −1.62 to 4.27; P=0.38]. No statistically significant difference was found for dislocations (OR =2.48; 95% CI: 0.67 to 9.14; P=0.17), infections (OR =1.07; 95% CI: 0.51 to 2.23; P=0.86), intraoperative fractures (OR =1.62; 95% CI: 0.42 to 6.21; P=0.48), and postoperative fractures (OR =1.60; 95% CI: 0.55 to 4.64; P=0.39). Conclusions: Modular and monoblock stems show comparable and satisfactory clinical and radiological outcomes for rTHA. Both stems are valid and effective options for managing femoral bone deficit in hip revision surgery. The main limitation of this study is the small number and low quality of enclosed studies that compared the two stems. Moreover, the modular stem is usually used for more complex cases with lower quality femoral bone stock
Visuomotor Integration for Coupled Hand Movements in Healthy Subjects and Patients With Stroke
Many studies have investigated the bilateral upper limb coordination during movements under different motor and visual conditions. Bilateral training has also been proposed as an effective rehabilitative protocol for patients with stroke. However, the factors influencing in-phase vs. anti-phase coupling have not yet been fully explored. In this study, we used a motion capture device based on two infrared distance sensors to assess whether the up and down oscillation of the less functional hand (the non-dominant one in healthy younger and older subjects and the paretic one in patients with stroke) could be influenced by in-phase or anti-phase coupling of the more functional hand and by visual feedback. Similar patterns were found between single hand movements and in-phase coupled movements, whereas anti-phase coupled movements were less ample, less sinusoidal, but more frequent. These features were particularly evident for patients with stroke who showed a reduced waveform similarity of bilateral movements in all conditions but especially for anti-phase movements under visual control. These results indicate that visuomotor integration in patients with stroke could be less effective than in healthy subjects, probably because of the attentional overload required when moving the two limbs in an alternating fashion
An objective, markerless videosystem for staging facial palsy
Background: The clinical classification of unilateral peripheral facial palsy (UPFP) is still based on subjective conventional methodology, leaving several missing points for an exact depiction of face deformity.
Aim of the study: To propose a new objective, video recording method that relies on mathematical algorithms allowing the software to recognize numerical points on the face surface that would be indicative of facial nerve impairment, without positioning of markers on the face.
Material and methods: Patients with UPFP of different House-Brackman (HB) degrees, from II to V, have been evaluated after video recording during two selected facial movements (forehead frowning and smiling) by a software trained to recognize the face points as numbers. Numerical parameters in millimeters have been obtained as indicative values of the shifting of the face points, and the shifting ratio between the healthy (denominator) and the affected side (numerator), i.e. the asymmetry index for the two movements taken into consideration.
Results: For each HB grade, specific ranges of asymmetry index have been identified with a positive correlation for shift differences and negative correlation for asymmetry indexes.
Conclusions: The use of the present objective system enabled the identification of numerical ranges of asymmetry index between the healthy and the affected side, that were found to be consistent with the outcome from the subjective methods currently in use
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