Craniofacial structure in patients with obstructive sleep apnoea

Background: Obstructive sleep apnoea (OSA) is characterised by at least five 10-s episodes of apnoea or markedly shallow breathing per 1 h of sleep, which can lead to severe, sometimes life-threatening complications. It is essential to determine the specific features of the affected patients’ craniofacial structure, thus enabling their allocation to risk groups. The aim of the study was to assess the craniofacial structure in OSA patients, comparing the findings with Hasund’s and Segner’s cephalometric normal values. In addition, the sagittal dimensions of the upper airways, measured at two levels, were compared to McNamara’s normal values. Materials and methods: The study covered 41 patients diagnosed polysomno­graphically with OSA. Lateral cephalograms with cephalometric analysis and the measurements of the upper and lower sagittal dimensions of the upper airways were taken for each patient. Results: The only feature of the patents’ facial skeleton that significantly diverged from the normal range was the SNB angle (p = 0.004). Other angles, i.e. SNA, ANB, NL/NSL, NL/ML and NSL/ML, were not significantly different from normal. The average upper cross-sectional area of the upper airways was 10.4 mm; in 97.6% patients, this measurement was below McNamara’s normal values. In the majority of patients (75.6%), the average lower sagittal dimension of the upper airways (10.4 mm) was also below the normal. Conclusions: Mandibular retrognathia, manifested by the reduced SNB angle, and the narrowed upper and lower sagittal dimensions of the upper airways can be considered one of OSA prognostic factors

Evaluation of upper airways depth among patients with skeletal Class I and III

Background: The aim of this study was to determine the value of upper andlower pharyngeal depth among patients with skeletal Class III malocclusion on lateral cephalograms, as well as to examine the relationship between SNA, SNB, and ANB angles, along with Wits appraisal and the cross-sectional value of upper airway space at the level of the soft palate and tongue base among patients withskeletal Class I and III.Materials and methods: The material consisted of lateral cephalograms taken from 80 patients living in the Lubelskie voivodeship. The study group consistedof cephalograms of 50 patients with skeletal Class III malocclusion (17 maleand 33 female), whereas the control group consisted of 30 roentgenograms of patients with Class I malocclusion with proper jaw to mandible relation (14 maleand 16 female). The study and the control group shared no statistically significant differences considering basic sociographic data such as gender (chi = 1.267, p = 0.26)and age (U = 727.5, p = 0.82). The upper and lower pharyngeal depths wereassessed with the use of McNamara’s method. Spearman’s rho test, Mann--Whitney’s U test, and chi test were used for statistical analysis.Results: Among both males and females the pharyngeal depths were greaterconsidering patients with skeletal Class III in comparison to patients with Class Imalocclusion (p < 0.001). Furthermore, it was determined that the lower as wellas the upper pharyngeal width is statistically significantly dependent on ANB and SNB angles and Wits appraisal (p < 0.001).Conclusions: Pharyngeal width at the level of the soft palate and tongue base depends on skeletal class, namely ANB angle and Wits appraisal; it increases with the increase of SNB angle (forward movement of the mandible). The SNA angle (position of the maxilla) does not influence the anterior-posterior nasopharyngeal dimension

Signatures of four-particle correlations associated with exciton-carrier interactions in coherent spectroscopy on bulk GaAs

Transient four-wave mixing studies of bulk GaAs under conditions of broad bandwidth excitation of primarily interband transitions have enabled four-particle correlations tied to degenerate (exciton-exciton) and nondegenerate (exciton-carrier) interactions to be studied. Real two-dimensional Fourier-transform spectroscopy (2DFTS) spectra reveal a complex response at the heavy-hole exciton emission energy that varies with the absorption energy, ranging from dispersive on the diagonal, through absorptive for low-energy interband transitions to dispersive with the opposite sign for interband transitions high above band gap. Simulations using a multilevel model augmented by many-body effects provide excellent agreement with the 2DFTS experiments and indicate that excitation-induced dephasing (EID) and excitation-induced shift (EIS) affect degenerate and nondegenerate interactions equivalently, with stronger exciton-carrier coupling relative to exciton-exciton coupling by approximately an order of magnitude. These simulations also indicate that EID effects are three times stronger than EIS in contributing to the coherent response of the semiconductor

Histological analysis reveals the formation of shoots rather than embryos in regenerating cultures of Eucalyptus globulus

Eucalyptus globulus is an important species in international forestry in regions with Mediterranean climates and comprises 65 % of the plantation hardwood in Australia. Propagation by somatic embryogenesis would offer many advantages and its development has received much attention. Structures regenerating on explants from hypocotyls of mature zygotic embryos of E. globulus cultured on medium with NAA, reported previously to be effective for embryogenic regeneration, were analyzed morphologically and histologically to clarify their pathway of development. Analysis of series of sections revealed organogenic, rather than embryogenic, pathways of regeneration in this system. We show that protocols for propagation of E. globulus must be carefully evaluated by microscopic examination of adequate numbers of serial sections

Origin of Magnetic Circular Dichroism in GaMnAs: Giant Zeeman Splitting versus Spin Dependent Density of States

We present a unified interpretation of experimentally observed magnetic circular dichroism (MCD) in the ferromagnetic semiconductor (Ga,Mn)As, based on theoretical arguments, which demonstrates that MCD in this material arises primarily from a difference in the density of spin-up and spin-down states in the valence band brought about by the presence of the Mn impurity band, rather than being primarily due to the Zeeman splitting of electronic states.Comment: 4+ pages, 4 figure