The effective dose due to scattered radiation at patients during primary osteosynthesis; a multicenter prospective observational study

Objectives: During osteosynthesis of a fracture patients are exposed to the primary radiation of an X-ray image and scattered (secondary) radiation. The primary objective was to measure the amount of scattered radiation at the thyroid, breast tissue, and gonads of patients undergoing primary osteosynthesis of acute fractures. The secondary objective was to calculate the effective dose caused by scattered radiation. Methods: In this multicenter prospective observational case series patients undergoing a primary osteosynthesis of an acute fracture of hand/wrist, shoulder, ankle, knee, or hip were included. Three dosimeters were attached to the patient at the level of the thyroid, breast and gonads. Scattered radiation doses were corrected for the average background radiation per hospital per day. Results: A total of 205 patients were included between March 6, 2017 and June 18, 2018; 49 (24%) had a hand/wrist fracture, 37 (18%) a shoulder fracture, 47 (23%) an ankle fracture, 35 (17%) a knee fracture, and 37 (18%) a hip fracture. In 32–39% of all patients undergoing primary osteosynthesis effective scattered doses was detected. The highest measured median effective dose was 60.43 µSv (P25–P75 33.84–100.76) at the gonads during hip osteosynthesis. Conclusions: The results of this study show that scattered radiation is detectable in a third of patients undergoing an osteosynthesis. However, both effective doses due to direct radiation and scattered radiation are low. Advances in knowledge: This is the first study that presents that no radiation protection for patients undergoing an osteosynthesis is necessary.Support Biomechanical Engineerin

Holocene evolution and signature of environmental change of the Burullus lagoon (Nile Delta) deciphered from a long sediment record

International audienceThis study presents high-resolution multi-proxy analyses of a well-dated sediment core (BR-1, 19.20 m long) retrieved from the Nile Delta, aiming to reconstruct the Holocene evolution of the Burullus lagoon. In particular, we focus on the morphodynamical processes, sediment provenances and related hydro-climatic changes. The Holocene strata of the lagoon coast comprise Early-Holocene marine transgressive facies and the Mid-Late Holocene retrogressive deltaic facies. Although BR-1 shows no river-channel facies, two peaks of magnetic susceptibility (MS) at ca. 8.0–7.0 ka (also associated with a high sedimentation rate of 50 mm/yr) and 3.5–2.0 ka evoke phases of greater morphodynamic influence of palaeo-Nile branches on the lagoon's development. Both dated peat layers (ca. 13 m and 8 m below MSL) and lagoon muds intercalated in BR-1, together with previously-dated peat strata were benchmarked relatively to MSL for the reconstruction of relative Holocene sea level in the study area. Our results show considerable land lowering on the Burullus coast indicated by a sea-level elevation, ca. 4–1 m lower than the one reconstructed along adjacent coastlines where less land subsidence occurred. The lagoon system began to form after ca. 6.0 ka in response to deceleration in sea-level rise and, being a shallower water body, both macrofauna (Cerastoderma glaucum etc.) and ostracods (Cyprideis torosa) of brackish-water nature emerged. In addition, geochemical data from BR-1 provide insights into environmental change in association with basin-wide hydro-climate fluctuations. Concomitant peaks in Fe/Al, Ti/Al and Cr/Al ratios (mafic origin), together with higher Zr/Al and Hf/Al ratios (felsic origin) before ca. 8.0 ka suggest sediment provenances derived from the White and the Blue Nile during the main African Humid Period (AHP). Since then, Ti/Al kept slightly ascending core-upwards with two pulses at 7.8–7.3 ka and 3.5–2.0 ka, which was asynchronous to Zr/Al and Hf/Al. This corroborates more sediments of basaltic origin transported to the delta coast after the main AHP due to southerly shift in the position of the ITCZ. The two periods of Ti/Al pulse are consistent with the MS peaks in BR-1, suggesting that palaeo-Nile branches remained active during 8.0–7.0 ka and 3.0–2.0 ka nearby

Thermal architecture for the QUBIC cryogenic receiver

QUBIC, the QU Bolometric Interferometer for Cosmology, is a novel forthcoming instrument to measure the B-mode polarization anisotropy of the Cosmic Microwave Background. The detection of the B-mode signal will be extremely challenging; QUBIC has been designed to address this with a novel approach, namely bolometric interferometry. The receiver cryostat is exceptionally large and cools complex optical and detector stages to 40 K, 4 K, 1 K and 350 mK using two pulse tube coolers, a novel 4He sorption cooler and a double-stage 3He/4He sorption cooler. We discuss the thermal and mechanical design of the cryostat, modelling and thermal analysis, and laboratory cryogenic testing

QUBIC: the Q and U bolometric interferometer for cosmology

QUBIC, the Q & U Bolometric Interferometer for Cosmology, is a novel ground-based instrument that has been designed to measure the extremely faint B-mode polarisation anisotropy of the cosmic microwave background at intermediate angular scales (multipoles o

Simulations and performance of the QUBIC optical beam combiner

QUBIC, the Q & U Bolometric Interferometer for Cosmology, is a novel ground-based instrument that aims to measure the extremely faint B-mode polarisation anisotropy of the cosmic microwave background at intermediate angular scales (multipoles o