Final Extent Research Articles

Low-frequency distributed acoustic sensing shape factors for fracture front detection

Accurate knowledge of fracture extents generated in multistage unconventional completions remains elusive. Crosswell low-frequency distributed acoustic sensing (LF-DAS) measurements can determine the time and location of a frac hit. Knowing where and when a frac hit occurs constrains the fracture extent but does not estimate it quantitatively. A recent study on crosswell LF-DAS demonstrated a simple method to rapidly determine the instantaneous fracture propagation rate when a frac hit occurs. This method, the zero strain-rate location method (ZSRLM), is based on laboratory experiments and numerical modeling assuming a radial fracture geometry. The method estimates a fracture propagation velocity that is used to extrapolate the final fracture extent. The propagation rate is calculated based on dynamic estimates of the nearest distance from the fiber to the front of a propagating fracture. The ZSRLM is adapted to estimate the distance to the fracture front based on rectangular fracture geometries. A 3D displacement discontinuity method program generates crosswell LF-DAS strain-rate waterfall plots considering a single, rectangular fracture of constant height. Over 150 different simulations were conducted varying formation mechanical properties, fracture height, and the vertical and horizontal offset between the treatment and monitor well. For each simulated case, the ZSRLM is used to estimate the distance to the fracture front based on the simulated waterfall plots. The difference between the estimated and actual distance to the front is corrected by a shape factor. The relationship among the shape factor, fracture height ratio, and vertical offset ratio is determined. Using a shape factor improves the performance of the ZSRLM by up to a factor of two for rectangular fractures. The updated ZSRLM is applied to extrapolate final fracture extents in two field cases: a single cluster stage in the Montney Formation and a multicluster stage of an Austin Chalk completion.

Microbial reduction and alteration of Fe(III)-containing smectites in the presence of biochar-derived dissolved organic matter

Clay minerals are important components of solid-phase iron pools in soils, and the redox state of structurally-coordinated iron in clay minerals can significantly influence soil physicochemical properties. Due to increasing use of biochar in agriculture, the dissolved organic matter derived from biochar (BDOM) has become an unignorable fraction of dissolved organic carbon in soil systems. However, our knowledge regarding the effect of BDOM on soil biogeochemical processes (particularly on iron redox cycling) is still very limited. To examine the role of BDOM in the microbial reduction of Fe(III) in clays, BDOM was extracted from wheat straw biochar and selectively added to laboratory reactors in which lactate, Fe(III)-containing smectite (montmorillonite SWy-2 or nontronite NAu-2), and a typical iron-reducing bacterium Shewanella oneidensis strain MR-1 were used as the respective electron donor, electron acceptor, and reaction mediator. The results demonstrated that BDOM contained bio-reactive quinone moieties. BDOM amendment increased the initial rate and final extent of Fe(III) bioreduction by strain MR-1. Such promotion effect of BDOM might be ascribed to its quinone moieties functioning as electron shuttles between MR-1 cells and structural Fe(III) in smectite. Structural changes were observed in the bioreduced smectite systems, especially for NAu-2 reactors in which obvious dissolution and illitization occurred. These observations suggest that BDOM is bio-reactive and is able to stimulate the microbial reduction of Fe(III) in clay minerals, and may offer new insights into the effects of biochar application in elemental cycles in soils.

Extraction and Classification of Flood-Affected Areas Based on MRF and Deep Learning

Floods can cause huge damage to society, the economy, and the environment. As a result, it is vital to determine the extent and type of land cover in flooded areas quickly and accurately in order to facilitate disaster relief and mitigation efforts. Synthetic aperture radar (SAR) is an all-weather, 24 h data source used to extract information about flood inundations, and its primary aim is to extract water body information for flood monitoring. In this study, we have studied the backscattering characteristics of water and non-water, combined the threshold segmentation method with Markov random fields (MRF), and embedded simulated annealing (SA) in the process of image noise reduction, resulting in the development of a water extraction method KI-MRF-SA with high accuracy in classification and high automation. Furthermore, object-scale adaptive convolutional neural networks (OSA-CNN) are introduced for the classification of optical images before the flood in order to provide reference data for flood inundation analysis. The method proposed in this study consists of the following three steps: (1) The Kittler and Illingworth (KI) thresholding algorithm is used for the segmentation of SAR images in order to determine the initial flood inundation extent; (2) MRF and SA algorithms are employed as a means to optimize the initial flood inundation extent, and the results are combined across multiple polarizations by using an intersection operation to determine the final flood inundation extent; and (3) As part of the flood mapping process, land cover types before the flood are classified using OSA-CNN and combined with flood inundation extents. According to the experimental results, it is evident that the proposed KI-MRF-SA method is capable of distinguishing water from non-water with significantly higher accuracy (3–5% improvement in the overall accuracy) than conventional thresholding methods. Combined with the classification method of OSA-CNN proposed in our earlier research, the overall classification accuracy of flood-affected areas could reach 92.7%.

A novel change detection and threshold-based ensemble of scenarios pyramid for flood extent mapping using Sentinel-1 data

Flood disasters destroy infrastructure, disrupt ecosystem processes, adversely affect social and economic activities and cause human fatalities. As such, flood extent mapping (FEM) is critical to mitigate these impacts. Specifically, FEM is essential to mitigate adverse impacts through early warning, efficient response during evacuation, search, rescue and recovery. Furthermore, accurate FEM is crucial for policy formulation, planning and management, rehabilitation, and promoting community resilience for sustainable occupation and use of floodplains. Recently, remote sensing has become valuable in flood studies. However, whereas free passive remote sensing images have been common input into predictive models, damage assessment and FEM, their utility is constrained by clouds during flooding events. Conversely, microwave-based data is unconstrained by clouds, hence is important for FEM. Hence, to increase the reliability and accuracy of FEM using Sentinel-1 radar data, we propose a three-step process that builds an ensemble of scenarios pyramid (ESP) based on change detection and thresholding technique. We deployed the ESP technique and tested it on a use-case based on two, five and 10 images. The use-case calculated three co-polarized Vertical-Vertical (VV) and three cross-polarized Vertical-Horizontal (VH) normalized difference flood index scenarios to form six binary classified FEMs at the base. We ensembled the base scenarios to three dual-polarized centre FEMs, and likewise the centre scenarios to a final pinnacle flood extent map. The base, centre and pinnacle scenarios were validated using six binary classification performance metrics. The results show that the ESP increased the base-to-pinnacle minimum classification performance metrics with overall accuracy, Cohen's Kappa, intersect over union, recall, F1-score, and Matthews Correlation coefficient of 93.204%, 0.864, 0.865, 0.870, 0.927, and 0.871 respectively. The study also established that the VV channels were superior in FEM than VH at the ESP base. Overall, this study demonstrates the efficacy of the ESP for operational flood disaster management.

How Cooking Time Affects In Vitro Starch and Protein Digestibility of Whole Cooked Lentil Seeds versus Isolated Cotyledon Cells.

Lentils are sustainable sources of bioencapsulated macronutrients, meaning physical barriers hinder the permeation of digestive enzymes into cotyledon cells, slowing down macronutrient digestion. While lentils are typically consumed as cooked seeds, insights into the effect of cooking time on microstructural and related digestive properties are lacking. Therefore, the effect of cooking time (15, 30, or 60 min) on in vitro amylolysis and proteolysis kinetics of lentil seeds (CL) and an important microstructural fraction, i.e., cotyledon cells isolated thereof (ICC), were studied. For ICC, cooking time had no significant effect on amylolysis kinetics, while small but significant differences in proteolysis were observed (p < 0.05). In contrast, cooking time importantly affected the microstructure obtained upon the mechanical disintegration of whole lentils, resulting in significantly different digestion kinetics. Upon long cooking times (60 min), digestion kinetics approached those of ICC since mechanical disintegration yielded a high fraction of individual cotyledon cells (67 g/100 g dry matter). However, cooked lentils with a short cooking time (15 min) showed significantly slower amylolysis with a lower final extent (~30%), due to the presence of more cell clusters upon disintegration. In conclusion, cooking time can be used to obtain distinct microstructures and digestive functionalities with perspectives for household and industrial preparation.

Nanoplastics in the soil environment: Analytical methods, occurrence, fate and ecological implications

Soils play a very important role in ecosystems sustainability, either natural or agricultural ones, serving as an essential support for living organisms of different kinds. However, in the current context of extremely high plastic pollution, soils are highly threatened. Plastics can change the chemical and physical properties of the soils and may also affect the biota. Of particular importance is the fact that plastics can be fragmented into microplastics and, to a final extent into nanoplastics. Due to their extremely low size and high surface area, nanoplastics may even have a higher impact in soil ecosystems. Their transport through the edaphic environment is regulated by the physicochemical properties of the soil and plastic particles themselves, anthropic activities and biota interactions. Their degradation in soils is associated with a series of mechanical, photo-, thermo-, and bio-mediated transformations eventually conducive to their mineralisation. Their tiny size is precisely the main setback when it comes to sampling soils and subsequent processes for their identification and quantification, albeit pyrolysis coupled with gas chromatography-mass spectrometry and other spectroscopic techniques have proven to be useful for their analysis. Another issue as a consequence of their minuscule size lies in their uptake by plants roots and their ingestion by soil dwelling fauna, producing morphological deformations, damage to organs and physiological malfunctions, as well as the risks associated to their entrance in the food chain, although current conclusions are not always consistent and show the same pattern of effects. Thus, given the omnipresence and seriousness of the plastic menace, this review article pretends to provide a general overview of the most recent data available regarding nanoplastics determination, occurrence, fate and effects in soils, with special emphasis on their ecological implications.

Comparative study on the structural and in vitro digestion properties of starch within potato parenchyma cells under different cooking methods

To study the effects of cooking methods on the structure and digestion changes of starch encapsulated by cellular structure, intact potato parenchyma cells were successfully isolated and then subjected to different domestic cooking methods, including baking, frying, boiling, and autoclaving. The morphology, crystalline structure, thermal properties, and in vitro starch digestibility of cooked cell samples were investigated. Our results indicated that potato cell walls remained intact and performed as physical barriers preventing the diffusion/absorption of α-amylase to intracellular starch substrates after baking or frying treatment. However, boiling or autoclaving treatment destroyed cell wall structure, and the disrupted cellular structure reduced the digestion rate, likely by inhibiting diffusion of amylase through a weakened cell wall barrier, but could not lower the final digestion extent when compared to the pure starch. These findings suggested that potato products with lower glycemic index can be obtained by baking or frying treatment.

Network structure indexes to forecast epidemic spreading in real-world complex networks

Complex networks are the preferential framework to model spreading dynamics in several real-world complex systems. Complex networks can describe the contacts between infectious individuals, responsible for disease spreading in real-world systems. Understanding how the network structure affects an epidemic outbreak is therefore of great importance to evaluate the vulnerability of a network and optimize disease control. Here we argue that the best network structure indexes (NSIs) to predict the disease spreading extent in real-world networks are based on the notion of network node distance rather than on network connectivity as commonly believed. We numerically simulated, via a type-SIR model, epidemic outbreaks spreading on 50 real-world networks. We then tested which NSIs, among 40, could a priori better predict the disease fate. We found that the “average normalized node closeness” and the “average node distance” are the best predictors of the initial spreading pace, whereas indexes of “topological complexity” of the network, are the best predictors of both the value of the epidemic peak and the final extent of the spreading. Furthermore, most of the commonly used NSIs are not reliable predictors of the disease spreading extent in real-world networks.

Relationship between refractive outcomes and quantitative retinal vascularization and severity of plus disease in eyes treated with intravitreal bevacizumab.

The study aimed to investigate the relationship between refractive outcomes with the extent of retinal vascularization and severity of the plus disease in infants treated with intravitreal bevacizumab (IVB). Pre-IVB fundus images (PFIs), final fundus images (FFIs), and refractive outcomes of the 93 infants who underwent IVB monotherapy for type 1 and aggressive retinopathy of prematurity (A-ROP) were retrospectively evaluated. Quantitative measurements were performed on PFIs and FFIs. Pre-IVB plus severity was scored on a five-leveled scale. Correlation between spherical equivalent (SE) with pre-treatment and final extent of the temporal retinal vascularization and pre-treatment severity of plus disease was analyzed. There was a linear and low positive correlation between the extent of pre-IVB and final temporal retinal vascularization with final SE (p = 0.000, r = 0.267; P = 0.002, r = 0.274, respectively). There was a low negative correlation between the pre-IVB plus severity score with final SE (p = 0.012, r = -0.192). Gestational age (GA), birth weight (BW), IVB dose, presence of additional IVB, or laser treatments were not correlated with refractive outcome. Out of 171 eyes, 38 eyes had >1 D myopia. In the univariate logistic analyses, pre-IVB retinal zone and pre-IVB and final extent of the temporal retinal vascularization were found to be related to the development of >1 D myopia (p = 0.002, odds ratio (OR) = 0.298; P = 0.000, OR = 0.281; P = 0.001, OR = 0.317; respectively). Our study indicates that the pre-treatment and final extent of retinal vascularization were the main parameters that were related to final refractive outcomes in IVB-treated eyes for type 1 and A-ROP.

Wetland spectral unmixing using multispectral satellite images

Wetlands are of great importance to the diversity of biota and ecology, thereby to humans. Monitoring such valuable areas is essential for sustainable development. When the sizes, geographic distribution, and total coverage of wetlands across the earth are taken into account, remote sensing shines out as the most economically and technically feasible method to realise the monitoring task. Concerning the utilisation of medium resolution satellite images as the input, the pixel-level approach falls short of understanding the wetland dynamics since vast amounts of pixels in such areas have mixed content. This study proposes a framework for determining the extent of wetlands and extracting their ground characteristics at the sub-pixel level. In the extent determination part, Tasselled Cap Water Index (TCWI) values are calculated on time series, and their variations throughout the year are modelled by fitting a double-sided sigmoid function. This information is coupled with Digital Terrain Model (DTM) thresholding to extract the final extent. A sub-pixel analysis is proposed for the latter part, which includes adopting a systematic approach using a three-element (soil, vegetation, water) scheme for establishing wetland ontology and implementing supervised spectral unmixing enhanced by band weight optimisation. Balıkdamı, one of the most impressive wetlands of Turkey, is chosen as the test area. Open-access optical satellite data acquired by the Sentinel-2 constellation are utilised as the primary data input. Since the abundance values of land cover classes in each Sentinel-2 pixel are estimated, reference abundance data with a 10 m ground sampling distance (GSD) are generated using four-band aerial images having a 30 cm GSD for the verification stage. A new method entitled ‘Abundance Confusion Matrix’ is introduced for comparison and detailed assessment of fractional land cover. Experimental results demonstrate that the extent determination is addressed with a precision of 99.21% and a miss rate of 5.75%. In addition, the abundance values of land cover classes are identified with an overall accuracy of 66.17% after the optimisation step. The proposed method proves to be a valuable tool for the detailed monitoring of wetlands.

Experimental investigation and micromechanics-based damage modeling of the stress relaxation mechanical properties in gray sandstone

The geomechanical behaviors of the gray sandstones under dry and fully saturated conditions are investigated by both of experimental and numerical studies in this paper. Conventional triaxial compression tests and single-stage stress relaxation tests are performed on cylindrical specimens under these two different states. The experimental results show that both peak strength and elastic modulus are reduced due to the presentence of the pore water which is contributed the weakening. While the typical incomplete attenuation characteristics of the two states are only having slight difference, the final stress relaxation extent under the statured condition is larger than the dry condition when the strain ratio is the same. Based on the pioneering work, a new micromechanical damage–friction coupling constitutive model with containing fewer parameters and each being physically meaningful for the stress relaxation is proposed here. Its chief novelty lies in considering both the instantaneous plastic internal variables and relaxation load to build the relationship between model’s parameter and experimental data. The single-stage relaxation tests of the sandstones are well-benchmarked with this model, which indicates that the proposed new model can capture the incomplete attenuation features of stress relaxation behavior of gray sandstones.

The percentage of unnecessary mastectomy due to false size prediction by preoperative imaging studies in patients with breast cancer who underwent neoadjuvant chemotherapy.

573 Background: It was shown that, with neoadjuvant chemotherapy (NCT), about 40-50% of breast conserving surgery (BCS) ineligible breast cancer converted to BCS-eligible. Because the estimated tumor extent with imaging after NCT tend to be discordant with pathologic extent, we assumed that proportion of unnecessary total mastectomy (TM) might be greater in NCT patients compared with non-NCT patients. We aimed to determine the proportion of TM for potential BCS candidate due to false size prediction after NCT and factors affecting that. Methods: We prospectively enrolled patients with invasive breast cancer (Stage II or III) who were scheduled for TM from 2018 to 2021 at Seoul National University Hospital (SNUH). Patients who were determined to undergo TM by only patient’s preference, who had BRCA1/2 mutation, multicentric cancer, diffuse malignant calcification over more than a quadrant, and inflammatory cancer were excluded. The decision of TM was done by operating surgeon considering the tumor extent, location, and breast size. Breast imaging including mammography, ultrasonography (USG), and MRI were done in patients. Before surgery, each surgeon recorded a hypothetic maximum tumor size (HMS) that the surgeon would have been able to try BCS if the patient had actually less than that size of tumor at that location in the patient. After operation, the HMS was compared with final pathologic total extent of the tumor including invasive and in situ cancer. In SNUH, decisions and tries of BCS led to eventual BCS with negative margin in 97.4% of patients during same period with this study. Results: Among 360 patients enrolled, 130 were patients who underwent NCT, and 230 were chemotherapy naïve as a control group. 62 of 130 (52.3%) in the NCT group and 49 of 230 (21.3%) in the non-NCT group were found to have smaller tumor extent than the pre-recorded HMS, respectively (NCT vs non-NCT p-value &lt;0.001). Further analyses were done only for NCT group. In an analysis according to subtype, the proportion of TM with false size prediction were more in HER2-positve (63.3%) and triple-negative breast cancer (TNBC) (57.6%) than in ER-positive/HER2-negative breast cancer (25.0%) (p-value &lt;0.001). In an imaging analysis, MRI size were larger than HMS in 73.8% of all patients. Both MRI-pathology size and USG-pathology size discrepancies were significantly associated with false decision of TM (both p&lt;0.001), but not with mammography. Without MRI, the false decision would have been reduced by 26.1%. Conclusions: We found that 52.3% of patients who received TM after NCT were actually BCS eligible, which was significantly higher than non-NCT patients. The proportion of false prediction were more in HER2-positive and TNBC. MRI imaging contributed to false size prediction and subsequent TM for BCS eligible patients. Clinical trial information: NCT04689529.

Model-Based Iterative Reconstruction (MBIR) for ASPECT Scoring in Acute Stroke Patients Selection: Comparison to rCBV and Follow-Up Imaging.

Background: To compare a model-based iterative reconstruction (MBIR) versus a hybrid iterative reconstruction (HIR) for initial and final Alberta Stroke Program Early Ct Score (ASPECT) scoring in acute ischemic stroke (AIS). We hypothesized that MBIR designed for brain computed tomography (CT) could perform better than HIR for ASPECT scoring. Methods: Among patients who had undergone CT perfusion for AIS between April 2018 and October 2019 with a follow-up imaging within 7 days, we designed a cohort of representative ASPECTS. Two readers assessed regional-cerebral-blood-volume-ASPECT (rCBV-ASPECTS) on the initial exam and final-ASPECTS on the follow-up non-contrast-CT (NCCT) in consensus. Four readers performed independently MBIR and HIR ASPECT scoring on baseline NCCT. Results: In total, 294 hemispheres from 147 participants (average age of 69.59 ± 15.63 SD) were analyzed. Overall raters’ agreement between rCBV-map and MBIR and HIR ranged from moderate to moderate (κ = 0.54 to κ = 0.57) with HIR and moderate to substantial (κ = 0.52 to κ = 0.74) with MBIR. Overall raters’ agreement between follow-up imaging and HIR/MBIR ranged from moderate to moderate (κ = 0.55 to κ = 0.59) with HIR and moderate to almost perfect (κ = 0.48 to κ = 0.82) with MBIR. Conclusions: ASPECT scoring with MBIR more closely matched with initial and final infarct extent than classical HIR NCCT reconstruction.

Fracture growth leading to mechanical spalling around deposition boreholes of an underground nuclear waste repository

This study presents a three-dimensional numerical analysis of multiple fracture growth leading to spalling around nuclear waste deposition boreholes. Mechanical spalling due to stress amplification after drilling is simulated using a finite element-based fracture growth simulator. Fractures initiate in tension based on a damage criterion and grow by evaluating stress intensity factors at each fracture tip. Tip propagation is multi-modal, resulting in final fracture patterns that are representative of both tensile and shear failure. Their geometries are represented by smooth parametric surfaces, which evolve during growth using lofting. The corresponding surface and volumetric meshes are updated at every growth step to accommodate the evolving fracture geometries. The numerical model is validated by comparing simulated fracture patterns against those observed in the AECL Underground Rock Laboratory Mine-By Experiment. It is subsequently calibrated to simulate fracture initiation and growth around boreholes drilled in the Forsmark granodiorite, subjected to a far-field anisotropic triaxial stress that corresponds to the in situ stress model from the Swedish Forsmark site. The deposition tunnel is implicitly simulated by attaching the deposition borehole to a free domain boundary. Several geomechanical cases are investigated, in which fracture growth is numerically evaluated as a function of in situ stress state, tunnel orientation, borehole geometry, total number of boreholes and borehole spacing. Numerical results show that spalling occurs in all cases, given the underground conditions at Forsmark, with borehole geometry, spacing and stresses affecting the extent of fracture nucleation and growth patterns. The uncertainty in underground stress conditions is evaluated through varying stress magnitudes and orientations relative to the tunnel floor. Whereas tunnel orientation influences the relative locations where fractures initiate with respect to the tunnel floor, fracture growth and its final extent is determined by the relative magnitudes of the in situ stresses. Higher stress differential causes higher spalling depths, but in all cases, failure extent is localised to the borehole vicinity, not exceeding one borehole radius. The cylindrical borehole is modified at the top to provide an access ramp for the spent fuel canisters and fracture growth around several deposition boreholes is simulated for borehole tops having cylindrical, conical, and wedge shapes. The enlargement of the borehole top induces higher stress concentrations at the borehole–tunnel junction, increasing the severity of spalling closer to the tunnel floor. Massive failure occurs when a multiple borehole model is considered and the inter-borehole distance is small enough that adjacent “spalled” areas interact. At Forsmark, through-going fractures are predicted to develop when the borehole spacing is less than 4 m. The effect of spalling on the structural integrity of the deposition boreholes is illustrated for each test case and quantified in terms of maximum spalling depth, spalling width and total fractured surface area.

Surgically Treated Femoral Neck Stress Fractures Are Likely to Result in Military Separation During Basic Combat Training.

Femoral neck stress fractures are a common condition affecting military service members, most noticeably during basic combat training. Previous studies have investigated the risk factors for femoral neck stress fracture development in basic trainees and outcomes associated with treatment; however, few studies have focused on operatively treated femoral neck stress fracture in the military trainee. Doing so would be important not only for the military, but also providers caring for athletes, such as distance runners, who have a heightened risk for femoral neck stress fracture development. (1) What proportion of US Army trainees completing basic combat training at Fort Jackson, SC, USA, who undergo surgery for femoral neck stress fracture during basic training subsequently leave military service because of the injury? (2) What factors are related to the patient or the fracture are associated with a higher likelihood of military separation? (3) What factors on the initial MRI are associated with progression of the stress fracture extent? A retrospective study of a longitudinally maintained database of stress injuries involving basic combat trainees from a single military post was reviewed over a 3-year period. Inclusion criteria included basic trainees undergoing surgery for a femoral neck stress fracture between January 2018 and June 2020 with a minimum of 1-year follow-up. Surgery was indicated for service members with complete and tension-sided femoral neck stress fractures and those with high risk compression-sided stress fractures, generally representing fractures involving more than 50% of the femoral neck width. Over the study period, 57 service members (51% [29 of 57] women with a mean age of 24 years) underwent surgery for a femoral neck stress fracture, and all 57 had a minimum of 1-year follow-up. Identified service members underwent independent data collection including injury and radiographic parameters based on chart and imaging review. Documented fracture line progression on repeat imaging was present in 39% of service members, with a mean fracture line progression of 55% of the femoral neck width. Service members were subdivided based upon the ability to return to military service at 1 year. Univariate analysis was performed using patient and injury variables to identify factors associated with the ability to return to military service. Overall, 58% (33 of 57) of service members who had a femoral neck stress fracture treated surgically underwent military separation. A higher proportion of service members who demonstrated fracture line progression leading to surgical treatment remained in the military (58% [14 of 24] versus 30% [10 of 33]; odds ratio 0.3 [95% confidence interval (CI) 0.1 to 0.9]; p = 0.03). With the numbers available, we found no other patient- or fracture-related variables associated with military separation, although we suspect we may have been underpowered on some of these comparisons, in particular gender (61% [20 of 33] of individuals separated after surgery for this injury were women compared with 38% [9 of 24] who were retained; OR 2.6 [95% CI 0.9 to 7.56]; p = 0.09). The extent of osseous edema on T1-weighted imaging in association with a hip effusion demonstrated a significant positive correlation with final fracture percentage (r = 0.62; p = 0.003). Military service members with a femoral neck stress fracture initially managed nonoperatively but with progression of the fracture line requiring surgical intervention were more likely to return to military duties and complete basic combat training, suggesting that early diagnosis of femoral neck stress fractures may be associated with better functional recovery after surgical treatment. Additionally, the extent of the osseous edema on initial MRI T1-weighted imaging sequences may help predict the final extent of femoral neck stress fractures on repeat imaging. Further investigations should incorporate patient-reported outcomes and further explore factors associated with fracture progression and the inability to return to active duty or sport. Level III, therapeutic study.

Individual movement variation in upstream‐migrating sea lamprey Petromyzon marinus in a highly fragmented river

Abstract Anthropogenic reductions in riverine connectivity can severely impede the migrations of anadromous species. In fragmented rivers, successful migrations depend on the ability of migrants to negotiate barriers or locate alternative passage routes. However, individual variation in the specific aspects of movement that determine migration success in fragmented rivers, is poorly characterised. Here, individual variation was investigated in the spawning migrations of 56 adult sea lamprey Petromyzon marinus, an anadromous, semelparous species that does not show fidelity to natal rivers. The variability and consequences of two key aspects of fish migration within fragmented rivers were tested: passage time (total time taken to pass a barrier) and retreats (exploratory downstream movements after unsuccessful passage attempts). These were tested using acoustic telemetry in the highly fragmented River Severn catchment, western England, U.K. Distinct unimodal, bimodal, and multimodal patterns of variation in passage times were displayed across the different barriers, potentially related to the physical characteristics of the barrier and prevailing river discharge conditions when the barriers were first approached, but were not related to lamprey body sizes. At the first three barriers encountered by upstream‐migrating sea lamprey in the study, between 30% and 46% of individuals made retreat movements, and between 5% and 100% of retreating individuals were able to locate alternative tributaries. Retreating individuals were highly variable in their distance and frequency of retreats; overall, retreat movements comprised 11% (lower‐upper quartiles 0%–52%, range 0%–76%) of the total distance moved before reaching spawning areas. Time‐to‐event analysis indicated that retreat rates reduced as river discharge increased. There was no evidence indicating that individual variation in passage time, or presence of retreat movements at barriers, influenced the subsequent upstream migration speed or final upstream extent of lampreys. While predictability in rank arrival timing was high within three unobstructed reaches, this predictability was disrupted at barriers due to individual variation in passage times. Anthropogenic barriers thus can both disrupt and reveal individual variation in the migration dynamics of anadromous species. Substantial variability in retreat behaviours can be displayed by anadromous species facing delays at barriers, with these behaviours also associated with environmental conditions and the availability of alternative migration routes. Individual variation in exploration and passage time of migrants strongly influence their eventual spawning distribution.

Crazing and Toughness in Diblock Copolymer-Modified Semicrystalline Poly(l-lactide)

Sustainable semicrystalline poly(l-lactide) (PLLA) was melt mixed with 5 wt % poly(ethylene oxide)-b-poly(butylene oxide) (PEO-PBO) diblock copolymer, resulting in blends that display an exceptional combination of properties. The blends were annealed at various temperatures, leading to different degrees of crystallinity. The addition of 5 wt % PEO-PBO produced finely dispersed liquid particles that caused a significant reduction in the time for crystallization after quenching from the melt, where Tm = 166 °C. At 95 °C, the halftime for crystallization was t1/2(95 °C) = t1/2o/7, while at 135 °C, t1/2(135 °C) = t1/2o/5, where t1/2o is the time required to obtain 50% of the final extent of crystallization with pure PLLA. The block copolymer particles also enhanced the ductility of the blends by facilitating stress-induced cavitation and uniform crazing without impacting the modulus. Tensile toughness increased by 7–15 fold, scaling inversely with the degree of crystallinity. The deformation mechanism was investigated by small- and wide-angle X-ray scattering as a function of applied strain, revealing that the craze volume is dependent on crystallinity, while the crystal structure displayed minimal changes. Regardless of the extent of crystallinity, crazing was found to be the primary deformation mechanism, countering the ductile-to-brittle transition associated with the aging of PLLA. Adding 5 wt % PEO-PBO extends the strain at break from 4% for pure PLLA after 2 days to more than approximately 50% after 85 or more days of aging. These findings, along with the industrially relevant blend preparation method, reveal that PEO-PBO is a unique and potent additive that could expand the applications served by PLLA, promoting a more sustainable future.

Curcumin-loaded composite hydrogel based on scallop (Patinopecten yessoensis) male gonad hydrolysates and κ-carrageenan: Characterization and in vitro digestibility

A composite hydrogel composed of scallop (Patinopecten yessoensis) male gonad hydrolysates (SMGHs) and κ-carrageenan (KC) was fabricated with a designed microstructure to preserve curcumin (Cur) during the upper gastrointestinal tract (GIT). The presence of KC obviously increased the initial elastic moduli (8.2–761.8 Pa), shortened the relaxation time T23 (517.37–420.10 ms) as well as caused the blue shift of the emission peak and quenched the intrinsic fluorescence of Cur in SMGHs/KC-Cur system, signifying the solid combination within SMGHs and KC. In addition, the red shift in O–H stretching bands and blue shift in amide I bands in SMGHs/KC-Cur further accentuated the involvement of hydrogen bonds and electrostatic interactions within SMGHs, KC and Cur. The disappearance of crystalline structures suggested the successful embedment of Cur in the hydrophobic core of SMGHs. Moreover, the microstructure of the hydrogels varied from heterogeneous with tattered large pore cavities and scattered patches to homogeneous distribution with dense mesh and solid network wall. These scenarios caused a more compact network of SMGHs/KC-Cur than SMGHs-Cur to protect Cur from releasing in simulated intestinal and simulated colonic phases with slower released rate, both of which had the final extent of Cur release exceeding 90%. Furthermore, cryo-SEM showed that the significant release of Cur from hydrogels in the simulated intestinal phase was due to SMGHs matrix erosion with even larger pore sizes, tattered network and thinner network wall. Therefore, it is suggested that SMGHs/KC hydrogels with biocompatibility and good tolerance to acid environment could be reliable and desirable soft materials to embed and deliver Cur to the colon, having potential applications in functional foods and biological therapeutic purposes.

Emulsifiers modulate the extent of gastric lipolysis during the dynamic in vitro digestion of submicron chia oil/water emulsions with limited impact on the final extent of intestinal lipolysis

Consumer demands for healthier foods are constantly on the rise and results in the diversification of sources such as vegetable oils. Chia oil is a relevant source of α-linolenic acid. One of the targeted applications is the inclusion of chia oil in emulsified form in beverages where it is necessary to obtain stable submicron emulsions, acting as carrier of nutrients such as lipids. In the present work, high-pressure homogenization was employed to produce emulsions (10% chia oil) with small oil droplets (300 nm), formulated with different emulsifiers (beta-lactoglobulin (BLG), lecithin and Tween 80). These emulsions were submitted to a dynamic in vitro digestion (DIDGI) to better understand the main mechanisms involved in the process of lipolysis, in order to design systems that may allow the modulation of the digestive action of lipases, thus ensuring the maximum bioaccessibility of the lipids. This device mimics part of the transient biochemical conditions as well as the flow of foods through the different compartments occurring in the real digestion. Significant differences were observed in the lipolysis during the gastric phase. BLGemulsions reached a lipolysis degree of 30%. Lecithin-stabilized emulsions behave similarly to BLG ones during the first 90 min but lipolysis levelled off further ∼20%. Finally, Tween-80-stabilized emulsions remained almost undigested (around 2%). No significant differences were noticed in duodenum and distal small intestine, irrespective of the emulsifier employed. After digestion, the fatty acid bioaccessibility was higher with BLG as emulsifier.

Towards understanding the modulation of in vitro gastrointestinal lipolysis kinetics through emulsions with mixed interfaces

The functionality of oil-in-water (o/w) emulsions may be modulated by combining emulsifiers rather than using an individual one. Based on our previous studies, citrus pectin (CP) and tween 80 (TW80) were selected as their emulsions presented different physical stability and in vitro lipolysis kinetics. Hence, our objective was to design and evaluate the in vitro lipolysis kinetics in both the gastric and small intestinal phase of five emulsions containing 5% triolein, 1% CP, and different concentrations of TW80 (0.00625–0.1%). For the initial emulsions, the interfacial load was quantified in terms of CP and TW80 and confirmed that both emulsifiers were present at the interface different ratios as a function of TW80 concentration. These emulsions were subjected to in vitro gastric digestion. Oil droplet characterization (particle size and microstructure) revealed a good to excellent physical stability. The kinetics of gastric lipid digestion were modulated by the TW80 concentration in the initial emulsions: higher magnitude of reaction rate constants (rate at which final extent is reached) and extent of lipolysis for lower TW80 concentrations. In addition, the kinetics of gastric lipase adsorption were also correlated with the lipolysis kinetics. In the small intestinal phase, three emulsions were prepared with 1% CP and 0.00625, 0.025 or 0.1% TW80 and in vitro digested. All emulsions were completely digested but the rate constant depended on the emulsion gastric stability. Overall, this study proposes an interesting strategy to modulate lipolysis kinetics in the gastric phase, but further research is needed to find another one to modulate small intestinal phase kinetics.