13,480 research outputs found

    Determining ‘Age at Death’ for Forensic Purposes using Human Bone by a Laboratory-based Analytical Method

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    Determination of age-at-death (AAD) is an important and frequent requirement in contemporary forensic science and in the reconstruction of past populations and societies from their remains. Its estimation is relatively straightforward and accurate (±3 years) for immature skeletons by using morphological features and reference tables within the context of forensic anthropology. However, after skeletal maturity (>35 yrs) estimates become inaccurate, particularly in the legal context. In line with the general migration of all the forensic sciences from reliance upon empirical criteria to those which are more evidence-based, AAD determination should rely more-and-more upon more quantitative methods. We explore here whether well-known changes in the biomechanical properties of bone and the properties of bone matrix, which have been seen to change with age even after skeletal maturity in a traceable manner, can be used to provide a reliable estimate of AAD. This method charts a combination of physical characteristics some of which are measured at a macroscopic level (wet & dry apparent density, porosity, organic/mineral/water fractions, collagen thermal degradation properties, ash content) and others at the microscopic level (Ca/P ratios, osteonal and matrix microhardness, image analysis of sections). This method produced successful age estimates on a cohort of 12 donors of age 53–85 yr (7 male, 5 female), where the age of the individual could be approximated within less than ±1 yr. This represents a vastly improved level of accuracy than currently extant age estimation techniques. It also presents: (1) a greater level of reliability and objectivity as the results are not dependent on the experience and expertise of the observer, as is so often the case in forensic skeletal age estimation methods; (2) it is purely laboratory-based analytical technique which can be carried out by someone with technical skills and not the specialised forensic anthropology experience; (3) it can be applied worldwide following stringent laboratory protocols. As such, this technique contributes significantly to improving age estimation and therefore identification methods for forensic and other purposes

    Cone beam CT of the musculoskeletal system : clinical applications

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    Objectives: The aim of this pictorial review is to illustrate the use of CBCT in a broad spectrum of musculoskeletal disorders and to compare its diagnostic merit with other imaging modalities, such as conventional radiography (CR), Multidetector Computed Tomography (MDCT) and Magnetic Resonance Imaging. Background: Cone Beam Computed Tomography (CBCT) has been widely used for dental imaging for over two decades. Discussion: Current CBCT equipment allows use for imaging of various musculoskeletal applications. Because of its low cost and relatively low irradiation, CBCT may have an emergent role in making a more precise diagnosis, assessment of local extent and follow-up of fractures and dislocations of small bones and joints. Due to its exquisite high spatial resolution, CBCT in combination with arthrography may be the preferred technique for detection and local staging of cartilage lesions in small joints. Evaluation of degenerative joint disorders may be facilitated by CBCT compared to CR, particularly in those anatomical areas in which there is much superposition of adjacent bony structures. The use of CBCT in evaluation of osteomyelitis is restricted to detection of sequestrum formation in chronic osteomyelitis. Miscellaneous applications include assessment of (symptomatic) variants, detection and characterization of tumour and tumour-like conditions of bone. Teaching Points: Review the spectrum of MSK disorders in which CBCT may be complementary to other imaging techniques. Compare the advantages and drawbacks of CBCT compared to other imaging techniques. Define the present and future role of CBCT in musculoskeletal imaging

    Comparative US-MRI evaluation of the Insall–Salvati index

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    Purpose: To investigate whether the universally accepted range of normal patellar height ratio derived from MRI for the Insall–Salvati (IS) method could be similarly applied to ultrasound (US). Materials and methods: This study included 52 patients (age range 11–75 years) who underwent a bi-modality (US and MRI) examination, with a total of 60 knees evaluated. IS index (ratio of the patella tendon length to length of the patella) was acquired with both methods. Two operators, with different experiences of musculoskeletal imaging and blinded to the results of other investigators, separately performed the MRI and US measurements. Results: For the two operators, MRI reported a mean value of patellar height ratio of 1.10 ± 0.16 (mean ± standard deviation SD), while US a mean value of 1.17 ± 0.16 (mean ± SD). For comparable results, the small addition of 0.16 is needed for the measurements on US compared with MRI. Inter-observer agreements using intra-class correlation coefficient (ICC) was, respectively, 0.97 for MRI and 0.98 for US. The difference of mean values in patellar height ratios between MRI and US was not statistically significant (p = 0.15). The ICC between the two modalities was 0.94. Conclusion: According to our experience, IS index can be appropriately evaluated on US images, reducing the need of other imaging techniques

    Is the immediate effect of marathon running on novice runners' knee joints sustained within 6 months after the run? A follow-up 3.0 T MRI study.

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    OBJECTIVE: To evaluate changes in the knee joints of asymptomatic first-time marathon runners, using 3.0 T MRI, 6 months after finishing marathon training and run. MATERIALS AND METHODS: Six months after their participation in a baseline study regarding their knee joints, 44 asymptomatic novice marathoners (17 males, 27 females, mean age 46 years old) agreed to participate in a repeat MRI investigation: 37 completed both a standardized 4-month-long training programme and the marathon (marathon runners); and 7 dropped out during training (pre-race dropouts). The participants already underwent bilateral 3.0 T MRIs: 6 months before and 2 weeks after their first marathon, the London Marathon 2017. This study was a follow-up assessment of their knee joints. Each knee structure was assessed using validated scoring/grading systems at all time points. RESULTS: Two weeks after the marathon, 3 pre-marathon bone marrow lesions and 2 cartilage lesions showed decrease in radiological score on MRI, and the improvement was sustained at the 6-month follow-up. New improvements were observed on MRI at follow-up: 5 pre-existing bone marrow lesions and 3 cartilage lesions that remained unchanged immediately after the marathon reduced in their extent 6 months later. No further lesions appeared at follow-up, and the 2-week post-marathon lesions showed signs of reversibility: 10 of 18 bone marrow oedema-like signals and 3 of 21 cartilage lesions decreased on MRI. CONCLUSION: The knees of novice runners achieved sustained improvement, for at least 6 months post-marathon, in the condition of their bone marrow and articular cartilage

    Do neurogenic and cancer-induced muscle atrophy follow common or divergent paths?

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    Skeletal muscle is a dynamic tissue capable of responding to a large variety of physiological stimuli by adjusting muscle fiber size, metabolism and function. However, in pathological conditions such as cancer and neural disorders, this finely regulated homeostasis is impaired leading to severe muscle wasting, reduced muscle fiber size (atrophy), and impaired function. These disease features develop due to enhanced protein breakdown, which relies on two major degradation systems: the ubiquitin-proteasome and the autophagy-lysosome. These systems are independently regulated by different signalling pathways, which in physiological conditions, determine protein and organelle turnover. However, alterations in one or both systems, as it happens in several disorders, leads to enhanced protein breakdown and muscle atrophy. Although this is a common feature in the different types of muscle atrophy, the relative contribution of each of these systems is still under debate. Here, we will briefly describe the regulation and the activity of the ubiquitin-proteasome and the autophagy-lysosome systems during muscle wasting. We will then discuss what we know regarding how these pathways are involved in cancer induced and in neurogenic muscle atrophy, highlighting common and divergent paths. It is now clear that there is no one unifying common mechanism that can be applied to all models of muscle loss. Detailed understanding of the pathways and proteolysis mechanisms involved in each model will hopefully help the development of drugs to counteract muscle wasting in specific conditions

    Steel Structure of the Building

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    Diplomová práce se zabývá návrhem nosné ocelové vícepodlažní konstrukce vědecké instituce v Brně. Práce obsahuje tři rozdílné variantní řešení v předběžném návrhu a pro zvolené řešení je zpracována technická zpráva, statický výpočet, výkaz materiálu a výkresy.The Master’s thesis concerns a design of load bearing multi-storey steel construction of scientific institution in Brno. This thesis contains three different solutions of a draft proposal and for the elected solution is processed technical report, structural analysis, material list and drawings.
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