45 research outputs found

    SPADA: A project to study the effectiveness of shielding materials in space

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    The SPADA (SPAce Dosimetry for Astronauts) project is a part of an extensive teamwork that aims to optimize shielding solutions against space radiation. Shielding is indeed an irreplaceable tool to reduce exposure of crews of future Moon and Mars missions. We concentrated our studies on two flexible materials, Kevlar R� and Nextel R,� because of their ability to protect human space infrastructures from micrometeoroids. We measured radiation hardness of these shielding materials and compared to polyethylene, generally acknowledged as the most effective space radiation shield with practical applications in spacecraft. Both flight test (on the International Space Station and on the Russian FOTON M3 rocket), with passive dosimeters and accelerator-based experiments have been performed. Accelerator tests using high-energy Fe ions have demonstrated that Kevlar is almost as effective as polyethylene in shielding heavy ions, while Nextel is a poor shield against high-charge and -energy particles. Preliminary results from spaceflight, however, show that for the radiation environment in low-Earth orbit, dominated by trapped protons, thin shields of Kevlar and Nextel provide limited reduction

    Reliability of forced internal rotation and active internal rotation to assess lateral instability of the biceps pulley

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    PURPOSE: the aim of this study was to investigate the relationship between positive painful forced internal rotation (FIR) and lateral pulley instability in the presence of a pre-diagnosed posterosuperior cuff tear. The same investigation was conducted for painful active internal rotation (AIR). METHODS: a multicenter prospective study was conducted in a series of patients scheduled to undergo arthroscopic posterosuperior cuff repair. Pain was assessed using a visual analog scale (VAS) and the Disabilities of the Arm, Shoulder and Hand questionnaire (DASH) was administered. The VAS score at rest, DASH score, and presence/absence of pain on FIR and AIR were recorded and their relationships with lesions of the lateral pulley, cuff tear patterns and shape of lesions were analyzed. RESULTS: the study population consisted of 115 patients (mean age: 55.1 years) recruited from 12 centers. The dominant arm was affected in 72 cases (62.6%). The average anteroposterior extension of the lesion was 1.61 cm. The mean preoperative VAS and DASH scores were 6.1 and 41.8, respectively. FIR and AIR were positive in 94 (81.7%) and 85 (73.9%) cases, respectively. The lateral pulley was compromised in 50 cases (43.4%). Cuff tears were partial articular in 35 patients (30.4%), complete in 61 (53%), and partial bursal in 19 (16.5%). No statistical correlation between positive FIR or AIR and lateral pulley lesions was detected. Positive FIR and AIR were statistically associated with complete lesions. Negative FIR was associated with the presence of partial articular tears. CONCLUSIONS: painful FIR in the presence of a postero-superior cuff tear does not indicate lateral pulley instability. When a cuff tear is suspected, positive FIR and AIR are suggestive of full-thickness tear patterns while a negative FIR suggests a partial articular lesion. LEVEL OF EVIDENCE: level I, validating cohort study with good reference standards

    Supraspinatus repair and biceps tenodesis in competitive crossfit athletes allow for a 100% of return to sport

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    Purpose: The shoulder is the most commonly injured body part in CrossFit training. The aim of this study is to report the clinical and MRI results of an arthroscopic repair of supraspinatus tear associated with SLAP lesion in competitive CrossFit athletes. Methods: Competitive CrossFit athletes affected by a full-thickness supraspinatus tear associated with SLAP lesion secondary to training injury were prospectively enrolled in the study. Clinical diagnosis was confirmed with MRI (> 1.5 T). Functional evaluation was done using the Constant Score (CS) and ASES score (ASES). All lesions were treated with single-row repair and biceps tenodesis. Minimum follow-up (clinical, MRI) was 24 months. Results: Nineteen patients were available at the final follow-up. The average age was 43-year-old (range 28–52, SD 8), 12 were males and 7 females. Pre-operative CS and ASES were 67 (range 61–77, SD 7) and 71 (range 62–79, SD 5), respectively. At the 24-month follow-up, 19/19 athletes resumed intensive training and 17/19 returned to competitions. CS and ASES rose to 90 (p = 0.039) and 93 (p = 0.04), respectively. At the final follow-up, MRI indicated complete healing of the tendon in 15 (79%) cases and 4 (21%) cases with type II Sugaya repair integrity. Two of the patients of the latter group did not return to their usual training level and showed type II (Kibler) scapular dyskinesis. Conclusions: Arthroscopic repair of the supraspinatus tendon associated with biceps tenodesis led to a 100% of return-to-CrossFit training and 90% rate of individuals resuming competitions at 24 months of follow-up. MRI showed 15 (79%) cases of complete healing and 4 (21%) cases with type II Sugaya repair integrity; biceps tenodesis clinically failed only in 1 case and the athlete complained of a decrease in the competitions scores and opted to discontinue CrossFit competitions. Level of evidence: IV

    Fatal complication following pure ankle dislocation in a domestic setting: case report and review of the literature.

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    Pure ankle dislocation is a rare event that primarily results from high-energy trauma. Predisposing anatomical factors such as talar hypoplasia, ligament laxity, and previous sprains may play a key role. This report presents the case of a 55-year-old man with fatal anterior and posterior tibial artery tears following a pure anterolateral dislocation of the right ankle. To the best of our knowledge, no such cases have previously been reported in the English-language literature

    Study of different Time Attenuation Curve processing in Liver CT Perfusion

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    A valuable alternative to traditional diagnostic tool to record fetal heart rate, to monitor the general fetal wellbeing, is fetal phonocardiography, a passive and low cost acoustic recording of fetal heart sounds. In this paper, it is presented a simulating software of fetal phonocardiographic signals relative to different fetal physiological states and recording conditions (for example different kinds and levels of noise). This software can be useful to test and assess fetal heart rate extraction algorithms from fetal phonocardiographic recordings and as a teaching tool for demonstration to medical students and others
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