112 research outputs found
Physico-Chemical Characterization of Keratin from Wool and Chicken Feathers Extracted Using Refined Chemical Methods
In this work, the characteristic structure of keratin extracted from two different kinds of industrial waste, namely sheep wool and chicken feathers, using the sulfitolysis method to allow film deposition, has been investigated. The structural and microscopic properties have been studied by means of scanning electron microscopy (SEM), Raman spectroscopy, atomic force microscopy (AFM), and infrared (IR) spectroscopy. Following this, small-angle X-ray scattering (SAXS) analysis for intermediate filaments has been performed. The results indicate that the assembly character of the fiber can be obtained by using the most suitable extraction method, to respond to hydration, thermal, and redox agents. The amorphous part of the fiber and medium range structure is variously affected by the competition between polar bonds (reversible hydrogen bonds) and disulfide bonds (DB), the covalent irreversible ones, and has been investigated by using fine structural methods such as Raman and SAXS, which have depicted in detail the intermediate filaments of keratin from the two different animal origins. The preservation of the secondary structure of the protein obtained does offer a potential for further application of the waste-obtained keratin in polymer films and, possibly, biocomposites
Segond's fracture: a biomechanical cadaveric study using navigation
Background Segondâs fracture is a well-recognised radiological
sign of an anterior cruciate ligament (ACL) tear.
While previous studies evaluated the role of the anterolateral
ligament (ALL) and complex injuries on rotational
stability of the knee, there are no studies on the biomechanical
effect of Segondâs fracture in an ACL deficient
knee. The aim of this study was to evaluate the effect of a
Segondâs fracture on knee rotation stability as evaluated by
a navigation system in an ACL deficient knee.
Materials and methods Three different conditions were
tested on seven knee specimens: intact knee, ACL deficient
knee and ACL deficient knee with Segondâs fracture. Static
and dynamic measurements of anterior tibial translation
(ATT) and axial tibial rotation (ATR) were recorded by the
navigation system (2.2 OrthoPilot ACL navigation system
B. Braun Aesculap, Tuttlingen, Germany).
Results Static measurements at 30 showed that the mean
ATT at 30 of knee flexion was 5.1 ± 2.7 mm in the ACL
intact condition, 14.3 ± 3.1 mm after ACL cut
(P = 0.005), and 15.2 ± 3.6 mm after Segondâs fracture
(P = 0.08). The mean ATR at 30 of knee flexion was
20.7 ± 4.8 in the ACL intact condition, 26.9 ± 4.1 in
the ACL deficient knee (P[0.05) and 30.9 ± 3.8 after
Segondâs fracture (P = 0.005). Dynamic measurements
during the pivot-shift showed that the mean ATT was
7.2 ± 2.7 mm in the intact knee, 9.1 ± 3.3 mm in the
ACL deficient knee(P = 0.04) and 9.7 ± 4.3 mm in the
ACL deficient knee with Segondâs fracture (P = 0.07).
The mean ATR was 9.6 ± 1.8 in the intact knee,
12.3 ± 2.3 in the ACL deficient knee (P[0.05) and
19.1 ± 3.1 in the ACL deficient knee with Segondâs
lesion (P = 0.016).
Conclusion An isolated lesion of the ACL only affects
ATT during static and dynamic measurements, while the
addition of Segondâs fracture has a significant effect on
ATR in both static and dynamic execution of the pivot-shift
test, as evaluated with the aid of navigation
The future of sovereignty in multilevel governance Europe: a constructivist reading
Multilevel governance presents a depiction of contemporary structures in EU Europe as consisting of overlapping authorities and competing competencies. By focusing on emerging non-anarchical structures in the international system, hence moving beyond the conventional hierarchy/anarchy dichotomy to distinguish domestic and international arenas, this seems a radical transformation of the familiar Westphalian system and to undermine state sovereignty. Paradoxically, however, the principle of sovereignty proves to be resilient despite its alleged empirical decline. This article argues that social constructivism can explain the paradox, by considering sovereign statehood as a process-dependent institutional fact, and by showing that multilevel governance can feed into this process
Progressive realism and the EUâs international actorness: towards a grand strategy?
The EU lacks a coherent strategy to guide its international actions.This is a problem that has been amply discussed in both academic and policy-making circles, but that remains to be fully addressed. The December 2013 European Council recognised the issue, and the EU High Representative Federica Mogherini is in charge of a strategic review that will lead to a global strategy by June 2016. Most arguments in favour of a grand strategy rely on utilitarian arguments that highlight the EUâs potential for a more efficient foreign policy. By linking a progressive realist approach to the importance of an EU grand strategy, this article intends to demonstrate the normative need for such a guiding document. As it will be argued, a grand strategy is a necessary step in the consolidation of the EU as a pluralist postnational polity that has in the fulfilment of its citizensâ interests its raison dâĂȘtre
The human condition of politics: considering the legacy of Hans J. Morgenthau for international relations
Single harvesting in the all-inside graft-link technique: is the graft length crucial for success? A biomechanical study
Governing differentiation : on standardisation as political steering
The introduction of Luhmannâs System Theory to International Relations has been long overdue. In the last few years, articles by Donnelly (2012) and Buzan and Albert (2010) have started to discuss the application of the concept of differentiation to International Relations theory, and an edited book by Albert et al. (2010) has examined how systemic thought can reinvigorate the study of world politics. This article welcomes and continues these developments by proposing a Luhmannian reinterpretation of the evolution and functioning of governance via standards. The article argues that standardisation â involving the proliferation of standards but also of standardised instruments such as rankings, indicators and benchmarks â can be understood as a mechanism of political steering in a growingly differentiated (world) society. By considering standardisation as a systemic adaptation of the political system to a multifunctional environment, this article contests conventional economistic and power-based explanations where the âstandardisation turnâ in global governance is a mere consequence of neoliberal globalisation, power struggles among states or some type of hegemonic logic. In this manner, the article suggests that Luhmannâs Systems Theory can provide a more encompassing framework to understand the operation of standards as an extension of politics beyond territory, and to frame the challenges of governing an increasingly complex world
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