Nasal surgery in patients with systemic disorders

Multisystemic disorders represent a heterogenous group of diseases which can primarily manifest at the nose and paranasal sinuses as limited disease or secondarily as part of systemic involvement. Rhinologists therefore play an important role in the diagnostic but also therapeutic process. Although therapy of multisystemic disorders is primary systemic, additional rhinosurgery may become necessary. The spectrum of procedures consists of sinus surgery, surgery of the orbit and lacrimal duct, septorhinoplasty and closure of nasal septal perforation. Since the prevalence of most systemic diseases is very rare, recommendations are based on the analysis of single case reports and case series with a limited number of patients only. Although data is still limited, experiences published so far have shown that autologous cartilage or bone grafts can be used in nasal reconstruction of deformities caused by tuberculosis, leprosy, Wegener’s granulomatosis, sarcoidosis and relapsing polychondritis. Experiences gained from these diseases support the concept that well-established techniques of septorhinoplasty can be used in systemic diseases as well. However, a state of remission is an essential condition before considering any rhinosurgery in these patients. Even under these circumstances revision surgery has to be expected more frequently compared to the typical collective of patients undergoing septorhinoplasty. In addition, experiences gained from saddle nose reconstruction may in part be of value for the treatment of nasal septal perforations since implantation of cartilage grafts often represents an essential step in multilayer techniques of closure of nasal septal perforations. Aside from the treatment of orbital complications sinus surgery has been proven beneficial in reducing nasal symptoms and increasing quality of life in patients refractory to systemic treatment

Constrained motion design with distinct actuators and motion stabilization

The design of adaptive structures is one method to improve sustainability of buildings. Adaptive structures are able to adapt to different loading and environmental conditions or to changing requirements by either small or large shape changes. In the latter case, also the mechanics and properties of the deformation process play a role for the structure's energy efficiency. The method of variational motion design, previously developed in the group of the authors, allows to identify deformation paths between two given geometrical configurations that are optimal with respect to a defined quality function. In a preliminary, academic setting this method assumes that every single degree of freedom is accessible to arbitrary external actuation forces that realize the optimized motion. These (nodal) forces can be recovered a posteriori. The present contribution deals with an extension of the method of motion design by the constraint that the motion is to be realized by a predefined set of actuation forces. These can be either external forces or prescribed length chances of discrete, internal actuator elements. As an additional constraint, static stability of each intermediate configuration during the motion is taken into account. It can be accomplished by enforcing a positive determinant of the stiffness matrix.Deutsche ForschungsgemeinschaftMinisterium für Wissenschaft, Forschung und Kunst Baden‐WürttembergProjekt DEA

Motion design with efficient actuator placement for adaptive structures that perform large deformations

Adaptive structures have great potential to meet the growing demand for energy efficiency in buildings and engineering structures. While some structures adapt to varying loads by a small change in geometry, others need to perform an extensive change of shape to meet varying demands during service. In the latter case, it is important to predict suitable deformation paths that minimize control effort. This study is based on an existing motion design method to control a structure between two given geometric configurations through a deformation path that is optimal with respect to a measure of control efficiency. The motion design method is extended in this work with optimization procedures to obtain an optimal actuation system placement in order to control the structure using a predefined number of actuators. The actuation system might comprise internal or external actuators. The internal actuators are assumed to replace some of the elements of the structure. The external actuators are modeled as point forces that are applied to the structure nodes. Numerical examples are presented to show the potential for application of the motion design method to non-load-bearing structures

Feeding regulates sex pheromone attraction and courtship in Drosophila females

In Drosophila melanogaster, gender-specific behavioural responses to the male-produced sex pheromone cis-vaccenyl acetate (cVA) rely on sexually dimorphic, third-order neural circuits. We show that nutritional state in female flies modulates cVA perception in first-order olfactory neurons. Starvation increases, and feeding reduces attraction to food odour, in both sexes. Adding cVA to food odour, however, maintains attraction in fed females, while it has no effect in males. Upregulation of sensitivity and behavioural responsiveness to cVA in fed females is paralleled by a strong increase in receptivity to male courtship. Functional imaging of the antennal lobe (AL), the olfactory centre in the insect brain, shows that olfactory input to DA1 and VM2 glomeruli is also modulated by starvation. Knocking down insulin receptors in neurons converging onto the DA1 glomerulus suggests that insulin-signalling partly controls pheromone perception in the AL, and adjusts cVA attraction according to nutritional state and sexual receptivity in Drosophila females

A molecular brush with thermoresponsive poly(2-ethyl-2-oxazoline) side chains: a structural investigation

The thermoresponsive behavior of a poly(2-oxazoline)-based molecular brush is investigated in aqueous solution. The molecular brush under study, PiPOx100-g-PEtOx17, has a poly(2-isopropenyl-2-oxazoline) (PiPOx) backbone grafted with thermoresponsive poly(2-ethyl-2-oxazoline) (PEtOx) side chains. Since the backbone degree of polymerization is only a factor of ~ 6 higher than the ones of the side chains, it features an architecture between a star-like polymer and a comb-like polymer. Its aqueous solution exhibits lower critical solution temperature (LCST) behavior with a cloud point temperature Tcp = 40.5 °C at 30 g L−1. The temperature-dependent structural evolution is disclosed using dynamic light scattering (DLS) and small-angle neutron scattering (SANS). An increase of the molecular brush size is found upon heating from room temperature to Tcp, which is attributed to the extension of the backbone resulting from the dehydration and collapse of the side chains. Above Tcp, the size decreases again, which indicates the collapse of the whole molecular brush. Large aggregates are found to be present in the solution in the temperature range 25–50 °C. These become more compact, as the temperature is increased across Tcp

An atomic model of HIV-1 capsid-SP1 reveals structures regulating assembly and maturation

Maturation and inhibition of HIV-1 HIV-1 undergoes a two-step assembly process controlled largely by a single region of its Gag protein. Schur et al. determined a complete atomic model for this region within an assembled Gag protein lattice using cryo-electron tomography together with subtomogram averaging. Amino acids from different parts of multiple Gag molecules come together to form an intricate network of interactions that drive HIV-1 assembly. The final step of maturation into the infectious HIV-1 virus is controlled by structural changes in Gag that alter the accessibility of the final cleavage site to the viral protease. Science , this issue p. 506 </jats:p