Cell­free fetal DNA at 11­13 weeks of gestation is not altered in complicated pregnancies.

Non-invasive maternal cell-free fetal DNA (cffDNA) is a promising biomarker for screening common genetic syndromes. Alterations in the expression levels of cffDNA in the maternal circulation have been demonstrated in abnormal pregnancies. However, the results are conflicting. The present study aimed to investigate whether cffDNA levels are associated with pregnancy complications. The study group comprised pregnant women who presented with pregnancy complications, such as preterm birth, gestational hypertension, intrauterine growth retardation, gestational diabetes, polyhydramnios, oligohydramnios, vaginal bleeding and placental abruption. The control group comprised women who had a normal pregnancy course. Blood samples were obtained from 500 pregnant women between 11-13 weeks of gestation. cffDNA was amplified, sequenced and analyzed using the next-generation aneuploidy test of a Panorama-Natera kit. Nuchal translucency (NT) thickness as well as pregnancy associated plasma protein-A (PAPP-A) and ß-human chorionic gonadotropin (ß-hCG) levels were also assessed. Statistical analysis was performed in 494 out of the 500 samples collected with SPSS v.26 using non-parametric methods. The parameters were normalized by the multiples of median (MoM) method. The expression levels of PAPP-A, ß-hCG, and the NT mean MoM values were significantly different between the study and control groups (P=0.005, P<0.001 and P=0.007, respectively). However, the expression levels of cffDNA and the mean MoM values were not significantly different between these two groups (P=0.687). The findings of the present study support the conclusion that cffDNA expression is not altered in a series of pregnancy complications. The prognostic value of cffDNA in predicting adverse pregnancy outcomes requires further investigation.

Risk Factors for Surgical Site Infections in Patients Undergoing Emergency Surgery: A Single-centre Experience.

BACKGROUND/AIM: Surgical site infections (SSI) are associated with increased morbidity and mortality, and they occur more frequently during unplanned emergency surgical (ES) procedures rather than elective. Our aim was to determine the incidence of SSI within our ES cohort and to identify risk factors for SSI. PATIENTS AND METHODS: Data from consecutive patients undergoing ES in a single institution during a 5-year period were prospectively collected and analyzed. RESULTS: A total of 838 consecutive patients were included. The median age was 52 (IQR=25-71) years and some 368 (44%) were female. 157 (18.7%) of those patients developed SSI. The most commonly isolated pathogen was E. Coli (55.4%) followed by Staphylococcus Aureus (40.1%). The 30-day mortality rate of patients who presented SSIs was 14.6% compared to 6.8% of patients without SSI (p=0.002). Multivariable analysis showed that the type of wound, American Society of Anesthesiology score, severity and duration of surgery >90 min were independent risk factors for the occurrence of SSI. CONCLUSION: Identification of modifiable causative factors for SSI within an ES unit is paramount as they can critically impact postoperative outcomes.

Performance analysis of waveguide-mode resonant optical filters with stochastic design parameters.

The performance of optical filters with resonant waveguide gratings is investigated numerically in a stochastic context, assuming random fluctuations of various design variables. Specifically, we derive stochastic models based on polynomial chaos expansions, whose involved coefficients are obtained by computing spectral projections via sparse-grid quadrature. The latter exploits purely deterministic results from a rigorous coupled-wave analysis solver and requires less simulation data than standard Monte Carlo (MC) techniques. The statistical moments of the filter's spectral response are calculated reliably, as the comparison against reference results from MC analysis verifies, and the extraction of the Sobol indices reveals the structure's sensitivity with respect to specific design parameters. Moreover, the present analysis clearly points out that neglecting even small geometric variations in the filter design may produce misleading conclusions regarding the corresponding performance, with undesirable consequences in real-life applications.

Surface solitons in waveguide arrays: Analytical solutions.

A novel phase-space method is employed for the construction of analytical stationary solitary waves located at the interface between a periodic nonlinear lattice of the Kronig-Penney type and a linear or nonlinear homogeneous medium as well as at the interface between two dissimilar nonlinear lattices. The method provides physical insight and understanding of the shape of the solitary wave profile and results to generic classes of localized solutions having either zero or nonzero semi-infinite backgrounds. For all cases, the method provides conditions involving the values of the propagation constant of the stationary solutions, the linear refractive index and the dimensions of each part in order to assure existence of solutions with specific profile characteristics. The evolution of the analytical solutions under propagation is investigated for cases of realistic configurations and interesting features are presented such as their remarkable robustness which could facilitate their experimental observation.