Comparison of eleven commonly used formulae for sonographic estimation of fetal weight in prediction of actual birth weight

Objectives: The aim of the study is to compare the accuracy of 11 formulas in predicting fetal weight. Material and methods: The study includes 1072 pregnant women of gestational age from 28 to 42 weeks, who gave birth between January and June 2017. Pregnant women were divided into five groups; group 1, where actual birth weight (ABW) was less than 2500 g, group 2, where ABW was between 2500–4000 g, group 3, where ABW was above 4000 g. Group 4 — newborns with birth weight under 10 percentile and group 5 — newborns with birth weight above 90 percentile. The accuracy of the estimated fetal weight (EFW) was assessed by calculating absolute percentage error (APE) and ‘limits-of-agreement’. R Spearman correlation was utilized between EFW and ABW. Results: The most accurate formula for group 1 is Hadlock3 (MAPE = 7.04%), the narrowest limits of agreement has Combs — [mean (SD): 99.41 g (269.57 g)]. For group 2, the lowest MAPE (5.43%) has Ott, the narrowest limits of agreement belongs to Combs – [mean (SD): -101.36 g (275.88 g)] . For group 3 is Hadlock3 (MAPE = 5.79%), the narrowest limits of agreement has Hadlock5 [mean (SD): -637.32 g (209.59 g)]. For group 4 is Combs (MAPE = 7.72%), the narrowest limits of agreement has Combs [mean (SD): 195.77 g (264.97 g)]. For gr oup 5 is Warsof2 (MAPE = 7.06%), the narrowest limits of agreement has Campbell [mean (SD): 227.81 g (299.26 g)]. Conclusions: Median of absolute percentage error is the most useful parameter to predict birth weight. Each group of fetuses needs different formula to predict the most accurate weight

Sustainable injection moulding: The impact of materials selection and gate location on part warpage and injection pressure

This paper presents an approach of how warpage (i.e. part deflection) and injection pressure of an intricate geometry could be minimised by selecting an optimal thermoplastic material and injection gate location (through which the molten plastic flows into the cavity). The numerical analyses for mould filling considered four gate locations along with a PP (polypropylene), PS (polystyrene) and a fibre-filled PP material (each had different shrinkage characteristics, mechanical property and viscosity). Results of the cavity filling simulations indicated that (on average) the largest and smallest warpage was predicted with the PP and PS respectively. The warpage of the fibre-filled PP showed the most gate location dependent behaviour. In addition, the lowest injection pressure was associated with the fibre-filled PP. For reduced pressure, the best and second best solutions for gate location were the top and middle ones. In addition, specific attention was paid to differential fibre orientation, as one of the most important factors responsible for part warpage. In an attempt to maximise the part stiffness, the fibre-filled PP was selected. It became clear that the gate location affected the melt flow evolution and therefore the fibre orientation. Simulation results showed that bidirectional flow and asymmetrical fibre distribution was achieved with the gate positioned at the mid-section of the part. Unidirectional flow and therefore symmetrical fibre distribution could be achieved by placing the gate at the top section of the part. The injection moulding experimental utilised the fibre-filled PP along with the two aforementioned gate locations. It was discovered that warpage was present when the middle gate was applied, but it was successfully eliminated using the top gate location. It can be stated that differential fibre orientation did not cause warpage, but the asymmetrical distribution of fibre orientation did. The information discussed in the paper may be particularly useful in the early mould/part design stages when any modification can still be easily and cost-effectively implemented. An important finding is that the final gate location should only be chosen after the thermoplastic material properties and melt flow direction have been taken into account. The successful reduction of warpage and injection pressure may help to reduce the amount of production waste and energy consumption, ensuring defect-free sustainable manufacturing

Cerebrospinal fluid markers of neuroinflammation in delirium:A role for interleukin-1β in delirium after hip fracture

AbstractObjectiveExaggerated central nervous system (CNS) inflammatory responses to peripheral stressors may be implicated in delirium. This study hypothesised that the IL-1β family is involved in delirium, predicting increased levels of interleukin-1β (IL-1β) and decreased IL-1 receptor antagonist (IL-1ra) in the cerebrospinal fluid (CSF) of elderly patients with acute hip fracture. We also hypothesised that Glial Fibrillary Acidic Protein (GFAP) and interferon-γ (IFN-γ) would be increased, and insulin-like growth factor 1 (IGF-1) would be decreased.MethodsParticipants with acute hip fracture aged >60 (N=43) were assessed for delirium before and 3–4 days after surgery. CSF samples were taken at induction of spinal anaesthesia. Enzyme-linked immunosorbent assays (ELISA) were used for protein concentrations.ResultsPrevalent delirium was diagnosed in eight patients and incident delirium in 17 patients. CSF IL-1β was higher in patients with incident delirium compared to never delirium (incident delirium 1.74pg/ml (1.02–1.74) vs. prevalent 0.84pg/ml (0.49–1.57) vs. never 0.66pg/ml (0–1.02), Kruskal–Wallis p=0.03). CSF:serum IL-1β ratios were higher in delirious than non-delirious patients. CSF IL-1ra was higher in prevalent delirium compared to incident delirium (prevalent delirium 70.75pg/ml (65.63–73.01) vs. incident 31.06pg/ml (28.12–35.15) vs. never 33.98pg/ml (28.71–43.28), Kruskal–Wallis p=0.04). GFAP was not increased in delirium. IFN-γ and IGF-1 were below the detection limit in CSF.ConclusionThis study provides novel evidence of CNS inflammation involving the IL-1β family in delirium and suggests a rise in CSF IL-1β early in delirium pathogenesis. Future larger CSF studies should examine the role of CNS inflammation in delirium and its sequelae

Cerebrospinal fluid levels of neopterin are elevated in delirium after hip fracture

Background The inflammatory cell product neopterin is elevated in serum before and during delirium. This suggests a role for disordered cell-mediated immunity or oxidative stress. Cerebrospinal fluid (CSF) neopterin levels reflect brain neopterin levels more closely than serum levels. Here we hypothesized that CSF neopterin levels would be higher in delirium. Methods In this prospective cohort study, 139 elderly patients with acute hip fracture were recruited in Oslo and Edinburgh. Delirium was diagnosed with the confusion assessment method performed daily pre-operatively and on the first 5 days post-operatively. Paired CSF and blood samples were collected at the onset of spinal anaesthesia. Neopterin levels were measured using high-performance liquid chromatography. Results Sixty-four (46 %) of 139 hip fracture patients developed delirium perioperatively. CSF neopterin levels were higher in delirium compared to controls (median 29.6 vs 24.7 nmol/mL, p = 0.003), with highest levels in patients who developed delirium post-operatively. Serum neopterin levels were also higher in delirium (median 37.0 vs 27.1 nmol/mL, p = 0.003). CSF neopterin remained significantly associated with delirium after controlling for relevant risk factors. Higher neopterin levels were associated with poorer outcomes (death or new institutionalization) 1 year after surgery (p = 0.02 for CSF and p = 0.03 for serum). Conclusions This study is the first to examine neopterin in CSF from patients with delirium. Our findings suggest potential roles for activation of cell-mediated immune responses or oxidative stress in the delirium process. High levels of serum or CSF neopterin in hip fracture patients may also be useful in predicting poor outcomes

Surface Characteristics and Biological Evaluation of Si-DLC Coatings Fabricated Using Magnetron Sputtering Method on Ti6Al7Nb Substrate

Diamond-like carbon (DLC) coatings are well known as protective coatings for biomedical applications. Furthermore, the incorporation of different elements, such as silicon (Si), in the carbon matrix changes the bio-functionality of the DLC coatings. This has also been proven by the results obtained in this work. The Si-DLC coatings were deposited on the Ti6Al7Nb alloy, which is commonly used in clinical practice, using the magnetron sputtering method. According to the X-ray photoelectron spectroscopy (XPS) analysis, the content of silicon in the examined coatings varied from ~2 at.% up to ~22 at.%. Since the surface characteristics are key factors influencing the cell response, the results of the cells’ proliferation and viability assays (live/dead and XTT (colorimetric assays using tetrazolium salt)) were correlated with the surface properties. The surface free energy (SFE) measurements, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) analysis demonstrated that the polarity and wettability of the surfaces examined increase with increasing Si concentration, and therefore the adhesion and proliferation of cells was enhanced. The results obtained revealed that the biocompatibility of Si-doped DLC coatings, regardless of the Si content, remains at a very high level (the observed viability of endothelial cells is above 70%)

An Integration of a Peristaltic Pump-Based Extruder into a 3D Bioprinter Dedicated to Hydrogels

The 3D printing technologies used for medical applications are mostly based on paste extruders. These are designed for high capacity, and thus often feature large material reservoirs and large diameter nozzles. A major challenge for most 3D printing platforms is a compromise between speed, accuracy, and/or volume/mass of moving elements. To address these issues, we integrated a peristaltic pump into a bioprinter. That allowed for combining the most important requirements: high precision, a large material reservoir, and safety of biological material. The system of a fully heated nozzle and a cooled print bed were developed to maintain the optimal hydrogel temperature and crosslinking speed. Our modifications of the bioprinter design improved the mechanical properties of the printouts and their accuracy while maintaining the maximal survival rate of cells and increasing the capacity of the bioink reservoir

A system-of-systems perspective for simultaneous UAV sizing and allocation using design of experiments and simulation

Traditional approaches to aircraft sizing focus on maximizing the performance of the individual airframe as a standalone system. Customers, such as the Department of Defense, have recently looked more towards all-encompassing solutions to large problems by using a System-of-Systems approach instead of maximizing capability from a single aircraft or similar monolithic system. Shrinking budgets call for making the most efficient use of existing assets and addressing capability gaps in broad frameworks. The result is that optimizing the aircraft alone may not provide the customer with needed capabilities. Unmanned Aerial Vehicles (UAVs) performing Intelligence, Surveillance, and Reconnaissance (ISR) missions provide an example of systems designed to operate with other independent systems as part of a system-of-systems. In this research, a fleet of UAVs will provide wildfire detection in high terrain. The research investigates how to allocate existing systems along with a number of yet-to-be-defined UAVs. In this manner, the new UAVs may not be optimal for individual aircraft-based performance metrics, but they will enhance the capabilities of the fleet. Such a large, complex problem requires decomposition into a resource allocation problem using a Design of Experiments (DoE) to select configurations of UAV fleets to test by simulation using STK\u27s Aircraft Mission Modeler software package at the System-of-Systems level, and an aircraft sizing sub-problem using an SQP algorithm and the Breguet endurance equation to size the new UAV. The STK output is modeled using main effects and a response surface that shows the tradeoff between cost and coverage, enabling the customer to select the optimal allocation of existing and new UAVs and determine the key characteristics of the new UAVs that fit into this fleet. The new UAV sized for this specific mission, but from a System-of-Systems perspective, complements the UAV fleet, enhancing the capabilities of the System-of-Systems while only occasionally displacing the existing UAV assets