Change In Total Volume Research Articles

The spatio-temporal relationship between white matter lesion volume changes and brain atrophy in clinically isolated syndrome and early multiple sclerosis

BackgroundWhite matter lesions and brain atrophy are both present early in multiple sclerosis. However, the spatio-temporal relationship between atrophy and lesion processes remains unclear. MethodsYearly magnetic resonance images were analyzed in 392 patients with clinically isolated syndrome from the 5-year REFLEX/REFLEXION studies. Patients received early treatment (from baseline; N = 262) or delayed treatment (from month-24; N = 130) with subcutaneous interferon beta-1a. Global and central atrophy were assessed using FSL-SIENA to provide yearly percentage volume change of brain and ventricles, respectively. Yearly total lesion volume change was calculated by subtracting the sum of the negative lesion volume change (disappearing + shrinking) from the positive lesion volume change (new + enlarging) for each yearly interval, as determined by an in-house developed semi-automated method. Using linear mixed models, during the period where patients had received ≥1 year of treatment, we investigated whether total lesion volume change was associated with percentage brain volume change or percentage ventricular volume change in the next year, and vice versa. ResultsHigher total lesion volume change was related to significantly faster global atrophy (percentage brain volume change) in the next year (B = − 0.113, SE = 0.022, p < 0.001). In patients receiving early treatment only, total lesion volume change was also associated with percentage ventricular volume change in the next year (B = 1.348, SE = 0.181, p < 0.001). Voxel-wise analyses showed that in patients receiving early treatment, higher total lesion volume change in years 2, 3, and 4 was related to faster atrophy in the next year, and in year 4 this relationship was stronger in patients receiving delayed treatment. Interestingly, faster atrophy was related to higher total lesion volume change in the next year (percentage brain volume change: B = − 0.136, SE = 0.062, p = 0.028; percentage ventricular volume change: B = 0.028, SE = 0.008, p < 0.001). ConclusionsHigher lesion volume changes were associated with faster atrophy in the next year. Interestingly, there was also an association between faster atrophy and higher lesion volume changes in the next year.

Simulating the impact of privately owned automated vehicles within the region Test Bed Lower Saxony, Germany

Automated and connected vehicles are assumed to have a major impact on road safety, traffic flow, energy consumption, greenhouse gas emissions, as well as on future mobility. This paper aims to analyze, the impact of privately owned automated vehicles on travel behavior in the region covering the Test Bed Lower Saxony in Germany. The main focus is laid on the evaluation of long-distance trips in the entire study area as well as on commuter journeys to and from the city of Brunswick. An agent-based demand model in conjunction with a traffic flow model was used to simulate four scenarios with different penetration rates of fully automated vehicles. The results show a major shift in the mode share, an increasing of the daily mileage, and reduced travel time of the motorized individual transport, as well as minor changes in travel distance and total traffic volume.

The dynamics of cavitation bubbles in a sealed vessel

A model of cavitation bubbles is derived in liquid confined in an elastic sealed vessel driven by ultrasound. In this model, an assumption that the pressure acting on the sealed vessel due to bubble pulsations is proportional to total volume change of bubbles is made. Numerical simulations are carried out for a single bubble and for bubbles. The results show that the pulsation of a single bubble can be suppressed to a large extent in sealed vessel, and that of two matched bubbles with same ambient radius can be further suppressed. However, when two mismatched bubbles have the same ambient radii, an interesting breathing phenomenon takes place, where one bubble pulsates inversely with the other one. Due to this breathing phenomenon the suppression effect becomes weak, so the maximum radii of two mismatched bubbles can be larger than that of a single bubble or that of two matched bubbles in sealed vessel. Besides that, for two mismatched bubbles with different ambient radii, the small one in sealed vessel under some certain parameters can pulsate as strong as or even stronger than that of a single bubble in an open vessel.

WITHDRAWN: Effect of Disease Type on Changes in Total Lung Volume After Lung Transplantation

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Abstract 10328: Eicosapentaenoic Acid versus Mixed Eicosapentaenoic/Docosahexaenoic Acid Added to Statin Therapy for Reducing Plaque Volume in Coronary Atherosclerosis: A Systematic Review and Meta-Analysis of Prospective Randomized Trials

Introduction: Multiple trials demonstrate efficacy of eicosapentaenoic acid (EPA) for lowering cardiovascular risk. Imaging studies suggest this benefit may relate to measurable effects on coronary plaque. Interestingly, EPA mixed with docosahexaenoic acid (DHA) has largely failed to show clinical benefit. The differential effects of EPA and EPA/DHA on coronary plaque burden and characteristics, including prognostically significant features such as lipid volume, remain unclear. Methods: We performed a systematic review of clinical trials that longitudinally measured coronary plaque volume in patients randomized to statin+EPA or statin+EPA/DHA versus statin alone, and performed network meta-analysis to estimate the standardized mean difference (SMD) of these treatments in percent change of total plaque volume and plaque lipid volume. Results: Ten trials comprising 860 patients met inclusion criteria among 535 articles. Four studies used intravascular ultrasound, three used coronary CTA, and three used optical coherence tomography. Among statin, statin+EPA, and statin+EPA/DHA treatments, random effects analysis yielded changes of +1.7% [-2.8%, +6.3%], -11.0% [-20.7%, -1.3%], and -3.4% [-14.5%, +7.8%] in total plaque volume and +3.1% [-1.6%, +7.8%], -19.8% [-27.5%, -12.1%], and -6.4% [-20.3%, +7.5%] in plaque lipid volume. Compared with statin, statin+EPA achieved greater percent reduction in coronary plaque volume (total volume: SMD = 0.92, P = 0.002; lipid volume: SMD = 1.04, P = 0.003) but statin+EPA/DHA showed no difference (total volume: SMD = 0.19, P = 0.58; lipid volume: SMD = 0.42, P = 0.38). Conclusions: In this most up-to-date meta-analysis, EPA as an adjunct to statins is associated with significant reductions in coronary plaque burden, including plaque lipid volume - unlike EPA/DHA combinations. These differential effects on coronary atherosclerosis offer mechanistic insights to observed clinical benefits of statin+EPA therapy.

Regression and pseudoprogression of pediatric optic pathway glioma in patients treated with proton beam therapy.

We examined regression patterns in pediatric optic pathway gliomas (OPGs) after proton beam therapy (PBT) and evaluated local control and visual outcomes. A total of 42 brain magnetic resonance imaging (MRI) scans from seven consecutive sporadic OPGs that were initially treated with chemotherapy and received PBT between June 2007 and September 2016 at the National Cancer Center, Korea were analyzed. Patients underwent brain MRI regularly before and after PBT. Total tumor, cystic lesion, and solid enhancing lesion area delineation and volume calculations were performed on gadolinium-enhanced T1-weighted MRI using Eclipse version 13, Varian. The median follow-up period after PBT was 70months (range 47-88). The median age at the time of PBT was 7years (range 4-16) and the median duration of chemotherapy before referral to PBT center was 25months (range 3-70). The median time to the greatest increase in cystic volume was 32months (range 12-43) after PBT. Solid enhancing lesion volume gradually decreased throughout the follow-up period. On an individual basis, total volume change was varied. However, on average, it regressed, although at a slower rate than solid enhancing lesion volume did. The local control rate was 85.7% (5-year progression-free survival rate, 80%; 5-year overall survival rate, 100%) and the rate of vision preservation was 71.4% (five of seven patients). The regression patterns in pediatric OPGs after PBT involve significant cystic change. Therefore, total volume is not appropriate for evaluating response. Care by a multidisciplinary team is necessary to manage clinical symptoms related to radiologic changes.

Prescribed Water Intake in Autosomal Dominant Polycystic Kidney Disease

BackgroundArginine vasopressin promotes kidney cyst growth in autosomal dominant polycystic kidney disease (ADPKD). Increased water intake reduces arginine vasopressin and urine osmolality and may slow kidney cyst growth.MethodsIn this randomized controlled 3-year clinical trial, we randomly assigned adults with ADPKD who had a height-corrected total kidney volume in Mayo imaging subclass categories 1B to 1E and an estimated glomerular filtration rate of 30 ml/min/1.73 m2 or greater to (1) water intake prescribed to reduce 24-hour urine osmolality to 270 mOsmol/kg or less or (2) ad libitum water intake irrespective of 24-hour urine osmolality. The primary end point was the percentage annualized rate of change in height-corrected total kidney volume.ResultsA total of 184 patients participated in either the ad libitum water intake group (n=92) or the prescribed water intake group (n=92). Over 3 years, there was no difference in the annualized rate of change in height-corrected total kidney volume between the ad libitum (7.8% per year; 95% confidence interval [CI], 6.6 to 9.0) and prescribed (6.8% per year; 95% CI, 5.8 to 7.7) water intake groups (mean difference, −0.97% per year; 95% CI, −2.37 to 0.44; P=0.18). The difference in mean 24-hour urine osmolality between the ad libitum and prescribed water intake groups was −91 mOsmol/kg (95% CI, −127 to −54 mOsmol/kg), with 52.3% of patients achieving adherence to the target 24-hour urine osmolality and no reduction in serum copeptin over 3 years. The frequency of adverse events was similar between groups.ConclusionsFor patients with ADPKD, prescribed water intake was not associated with excess adverse events and achieved the target 24-hour urine osmolality for half of the patients but did not reduce copeptin or slow the growth of total kidney volume over 3 years compared with ad libitum water intake. (Funded by the National Health and Medical Research Council of Australia [grant GNT1138533], Danone Research, PKD Australia, the University of Sydney, and the Westmead Medical Research Foundation; Australian New Zealand Clinical Trials Registry number, ACTRN12614001216606).

Changes in total and segmental extracellular and intracellular volumes with hypotension during hemodialysis measured with bioimpedance spectroscopy.

Bioelectrical impedance analysis (BIA) devices have been advocated to guide volume management in hemodialysis (HD) patients. We hypothesized that understanding the dynamics of fluid shifts in different body segments may provide additional insight on preventive measures to reduce the risk of intradialytic hypotension. A prospective observational study was conducted among 42 HD patients at risk of hypotension who were admitted as emergencies inpatient. A total of 191 BIA measurements were made during the 42 HD sessions, and hypotension occurred during 52 measurements (27%). The extracellular water (ECW) to intracellular water ratio (EIR) was measured in different body segments and declined significantly only in the non-access arm with increasing HD session duration (β=-0.04; 95% confidence interval (CI): -0.05 to -0.03, p<0.01). There was no significant association between EIR and hypotension with respect to the different body segments. Only pre-HD N-terminal-pro b-type natriuretic peptide was significantly associated with hypotension (β=0.20, 95% CI: 0.04 to 0.89, p=0.04). There was no association between relative blood volume monitoring change and EIR. In summary, we found that segmental BIA during HD was unable to detect or predict hypotension during dialysis. Although BIA is able to provide information about ECW and guide clinical assessment of volume in HD patients prior to dialysis, our findings did not suggest the use of serial measurements of changes in EIR in different body segments during HD provided sufficient information to predict intradialytic hypotension. Similarly, changes in EIR did not provide information on changes in plasma volume that could potentially trigger interventions to prevent or reduce intra-dialytic hypotension.

Effect of Total Stress Path and Gas Volume Change on Undrained Shear Strength of Gassy Clay

Clay with free gas bubbles can be frequently encountered in the seabed. Gassy clay is an unsaturated soil, but its mechanical behavior cannot be described using conventional unsaturated soil mechanics because it has a composite internal structure with a saturated soil matrix and gas bubbles. The gas bubbles can have either a detrimental or beneficial effect on the undrained shear strength of clay. New lower and upper bounds for the undrained shear strength of gassy clay are derived by considering the effect of total stress path and plastic hardening of the saturated soil matrix. For the upper bound, it is assumed that there is only bubble flooding, and the shear strength of an unsaturated soil sample is the same as that of the saturated soil matrix. Bubble flooding makes the saturated soil matrix partially drained and increases the undrained shear strength. The amount of bubble flooding is calculated using the modified Cam-Clay model and Boyle's law for ideal gas. The lower bound is derived based on the assumption that the entire soil fails without bubble flooding and the gas cavity size evolves due to plastic hardening of the saturated soil matrix. Compared with Wheeler's upper and lower bounds that do not consider plastic hardening of the saturated soil matrix, the new theoretical results give a better prediction of the undrained shear strength of gassy clays, especially for the upper bound. Implications for constitutive modeling of gassy clay are discussed based on the new research outcomes.

Giant negative thermal expansion of polycrystalline Ti2O3 induced by microstructural effects

Discovery of giant negative thermal expansion (NTE) of Ti2O3 is reported herein. Ti2O3 undergoes a phase transition from a low-temperature (low-T) insulating state to a high-T metallic state gradually at temperatures of 400–600 K, accompanied by highly anisotropic thermal deformation of the crystallographic unit cell. This anisotropic deformation induces large bulk NTE in the sintered body, although the unit-cell volume estimated from diffraction experiments shows positive thermal expansion in this T range. Results of this study also demonstrate that partial replacement of Ti with Nb increases the total volume change related to bulk NTE and show that it lowers the operating-T range of NTE to include room temperature. The development of NTE materials particularly addressing such microstructural effects is effective and promising.

Prolonged Time of Lung Collapse Associated With Decreased Recovery of Functional Lung Following Palliative Radiotherapy

<h3>Purpose/Objective(s)</h3> Bronchial obstruction leading to lung collapse from primary lung or metastatic tumors is a common urgent consult to radiation oncology. Palliative chest radiotherapy (RT) can reduce the risk of progression of endobronchial or extrabronchial disease can be utilized alone or in combination with bronchial stenting to re-open existing collapsed lung. The ability to re-open collapsed lung following RT is likely multi-factorial with time since lung collapse long thought as an important predictor of reversibility. In this study, we sought to quantify the time-dependency of recovery of functional lung volume in patients with partial or complete lung collapse using a CT-based imaging metric highly correlated with lung function. <h3>Materials/Methods</h3> Patients with primary lung or metastatic tumors who received palliative chest RT due to segmental, lobar or whole lung collapse who additionally had follow-up CT imaging of the chest were identified from the institutional electronic health record. Total lung volumes on simulation and follow-up chest CTs were manually segmented using a commercially available software. To evaluate functional lung volume, a subthreshold function was applied to the image sets to determine volume of lung with attenuation of -950 to -701 HU. An estimate of time since initiation of lung collapse was determined by review of clinical records and imaging. <h3>Results</h3> A total of 25 evaluable patients were identified with non-small cell lung cancer (NSCLC) being the predominant histology observed (19/25, 76%). The median time of collapse before initiation of RT was 11 days (range = 3-57). The median dose received was 20 Gy in 5 fractions (range = 8 Gy/1 fx to 30 Gy/10 fx). The mean change in total lung volume was 1090 cc with mean change in functional lung volume of 1006 cc. Overall, a 92% increase in functional lung volume was observed following chest RT in this cohort. A linear trend toward decreasing recovery of functional lung was observed with more prolonged lung collapse (<i>P</i> = 0.074). Patients with estimated time of lung collapse of ≤14 days had higher mean recovery of functional lung (113%) compared with those with lung collapse > 14 days (55%) (<i>P</i> = 0.040). <h3>Conclusion</h3> Early initiation of palliative RT following lung collapse may lead to greater recovery of functional lung volume, which may confer a survival benefit/decrease hospitalization rates/improve fitness for systemic therapy. Improvements in targeted therapies are leading to more durable systemic responses potentially increasing the importance of timely chest RT for patients with existing or pending lung collapse as a bridge during acute thoracic events.

The Relationship between Ovarian Endometrioma Ultrasonographic Size and Treatment with Dienogest: A Retrospective Cohort Study

Study Objective To examine the change in ultrasonographic size of ovarian endometrioma during treatment with dienogest Design Retrospective single cohort chart review from 2011-2021. Setting Academic university-affiliated hospital ambulatory clinics Patients or Participants Patients from the study authors' practices were included who had ultrasound findings consistent with ovarian endometriomas. Those who were prescribed dienogest with at least one follow-up ultrasound 3 months or more after treatment initiation were included. Patients also had to be non-pregnant, premenopausal and over the age of 18. Patients were excluded if they underwent surgical management between ultrasonographic assessments of their endometrioma. Sample size was calculated to require 21 patients to detect a mean of the differences in endometrioma size of 1cm, with a power of 80% and a 5% level of significance, assuming the standard deviation of 1.5. Interventions Dienogest 2 mg orally daily for at least 3 months. Measurements and Main Results The primary outcome assessed was change in ultrasound measurement of endometrioma maximum diameter over the study period and secondary outcome was change in total volume. Demographic information was tabulated and described in means and measures of variance. The outcomes were assessed with a paired t-test. A sensitivity analysis was performed for those patients with a surgical diagnosis of endometriosis. A total of 53 patients met inclusion criteria. The average age of participants was 37.72 +/- 6.35, and they were followed for an average of 14.19 +/- 14.17 months. The average change in endometrioma greatest maximum diameter was 0.77 +/- 1.59 (p=0.002) and change in volume was 3.84 +/- 59.00 cm3 (p=0.67). Sensitivity analysis demonstrated a decrease in endometrioma maximum diameter and volume but was not significant. Conclusion Dienogest has the potential to reduce the size of ovarian endometrioma. Future prospective studies are warranted to determine if medical treatment can shrink endometriomas which may ultimately prevent the need for surgery and protect fertility. To examine the change in ultrasonographic size of ovarian endometrioma during treatment with dienogest Retrospective single cohort chart review from 2011-2021. Academic university-affiliated hospital ambulatory clinics Patients from the study authors' practices were included who had ultrasound findings consistent with ovarian endometriomas. Those who were prescribed dienogest with at least one follow-up ultrasound 3 months or more after treatment initiation were included. Patients also had to be non-pregnant, premenopausal and over the age of 18. Patients were excluded if they underwent surgical management between ultrasonographic assessments of their endometrioma. Sample size was calculated to require 21 patients to detect a mean of the differences in endometrioma size of 1cm, with a power of 80% and a 5% level of significance, assuming the standard deviation of 1.5. Dienogest 2 mg orally daily for at least 3 months. The primary outcome assessed was change in ultrasound measurement of endometrioma maximum diameter over the study period and secondary outcome was change in total volume. Demographic information was tabulated and described in means and measures of variance. The outcomes were assessed with a paired t-test. A sensitivity analysis was performed for those patients with a surgical diagnosis of endometriosis. A total of 53 patients met inclusion criteria. The average age of participants was 37.72 +/- 6.35, and they were followed for an average of 14.19 +/- 14.17 months. The average change in endometrioma greatest maximum diameter was 0.77 +/- 1.59 (p=0.002) and change in volume was 3.84 +/- 59.00 cm3 (p=0.67). Sensitivity analysis demonstrated a decrease in endometrioma maximum diameter and volume but was not significant. Dienogest has the potential to reduce the size of ovarian endometrioma. Future prospective studies are warranted to determine if medical treatment can shrink endometriomas which may ultimately prevent the need for surgery and protect fertility.

Low soluble amyloid-β 42 is associated with smaller brain volume in Parkinson's disease

IntroductionWe sought to examine whether levels of soluble alpha-synuclein (α‐syn), amyloid-beta (Aβ42), phosphorylated tau (p-tau), and total tau (t-tau), as measured in cerebrospinal fluid (CSF), are associated with changes in brain volume in Parkinson's disease. MethodsWe assessed the 4-year change in total brain volume (n = 99) and baseline CSF α‐syn, Aβ42, p-tau, and t-tau of Parkinson Progression Markers Initiative participants. We used linear mixed models to assess the longitudinal effect of baseline CSF biomarkers on total and regional brain volume and thickness as well as linear regression for cross-sectional analyses at baseline and year 2. All models were adjusted for age and gender; brain volume models also adjusted for baseline intracranial volume. Bonferroni correction was applied. ResultsThe 4-year change in total brain volume was −21.2 mm3 (95% confidence interval, −26.1, −16.3). There were no significant associations between the 4-year change in total brain volume and baseline levels of any CSF biomarker (all p-values > 0.05). On cross-sectional analyses, CSF Aβ42 was linearly associated with total brain volume at baseline (R2 = 0.60, p = 0.0004) and at year 2 (R2 = 0.66, p < 0.0001), with CSF Aβ42 < 1100 pg/ml, the threshold for brain amyloid pathology, associated with smaller total brain volume at baseline (p = 0.0010) and at year 2 (p = 0.0002). CSF α‐syn was linearly associated with total brain volume at baseline (R2 = 0.58, p = 0.0044) but not at year 2 (R2 = 0.58, p = 0.1342). ConclusionReduction in soluble Aβ42 is associated with lower total brain volume in Parkinson's disease.

Texture and degree of compactness effect on the pore size distribution in weathered tropical soils

Soil pores can be functionally classified into macro-, meso- and micropores. The volume of these pores is highly affected by constitutive and state components of soils, such as particle size distribution and degree of compactness. In this study, we aimed to examine the impact of soil texture and degree of compactness on total porosity, and distribution of macro-, meso- and micropores. Undisturbed soil cores were taken in eight differently textured soils cultivated with sugarcane and equilibrated at matric potentials of − 30 and − 100 hPa for calculation of macropores (effective pore diameter – EPD > 100 µm), mesopores (EPD 100–30 µm) and micropores (EPD < 30 µm). The volume of each pore category was modelled using additive spline functions of soil particle size and degree of compactness. Soil organic carbon and mean weight diameter of soil aggregate (MWD) were also measured to support the findings. Total porosity and macropores were dependent on the degree of compactness and silt plus clay content, whereas silt plus clay content significantly affected meso- and micropores. Total porosity and macroporosity decreased with increasing compactness, mainly for soils with silt plus clay content lower than ~500 g kg−1; especially for the macropores, these decreases were substantially reduced for further increase in silt plus clay content (> 500 g kg−1) due to the higher MWD verified for these soils. Mesopores were predominant in soils with lower silt plus clay content, while their volume was practically null in soils with silt plus clay content higher than 500 g kg−1, for which only macro- and micropores were observed. In conclusion, the increased degree of compactness may reduce both total porosity and macroporosity in a process whose magnitude depends on soil texture, whereas meso- and micropores have major changes associated only with particle size distribution. However, macropores showed to be also sensitive to soil aggregation rather than properly changes in total soil volume (e.g., degree of compactness).

Seizure control does not predict hippocampal subfield volume change in children with focal drug-resistant epilepsy.

Background and purposeRecurrent seizures have been reported to induce neuronal loss in the hippocampus. It is unclear whether seizure control influences hippocampal volume. The aims of this study were to determine if there was a change in total or subfield hippocampal volume over time in children with focal drug-resistant epilepsy, and whether seizure control influenced total or subfield hippocampal volumes.MethodsUsing FreeSurfer’s automated segmentation of brain magnetic resonance imaging scans, we calculated the total and subfield (including CA1, CA3, CA4, subiculum, presubiculum, parasubiculum, molecular layer and dentate gyrus) hippocampal volumes of children with non-lesional focal epilepsy. Seizure frequency and hippocampal volumes were assessed at baseline and follow-up. Patients were classified into those who were seizure free or have improvement in seizures (group 1) and those with no improvement in seizures (group 2) at follow-up.ResultsThirty-seven patients were included, with mean age 10.31 ± 3.68 years at baseline. The interval between the two magnetic resonance imaging scans was 2.59 ± 1.25 years. There was no significant difference in the total and subfield hippocampal volumes for the whole cohort at follow-up compared to baseline (all P > 0.002). Seizure control of the two groups did not predict total or subfield hippocampal volume, after controlling for baseline volume, age, severity of seizure frequency at baseline and time interval between the magnetic resonance imaging scans (all P > 0.002).ConclusionWe have found that total and subfield hippocampal volumes did not change, and seizure control did not predict hippocampal volumes at follow-up in children with drug-resistant epilepsy.

Toward Practical Solid-State Lithium–Sulfur Batteries: Challenges and Perspectives

ConspectusThe energy density of the ubiquitous lithium-ion batteries is rapidly approaching its theoretical limit. To go beyond, a promising strategy is the replacement of conventional intercalation-type materials with conversion-type materials possessing substantially higher capacities. Among the conversion-type cathode materials, sulfur constitutes a cost-effective and earth-abundant element with a high theoretical capacity that has a potential to be game-changing, especially within an emerging solid-state battery configuration. Employment of nonflammable solid electrolytes that improves battery safety and boosts the energy density, as lithium metal anodes are also viable. The long-standing inherent problem of conventional lithium–sulfur batteries, arising from the reaction intermediates dissolved in liquid electrolytes, can be eliminated with inorganic solid ion conductors. In particular, the highly conducting and easily processable lithium-thiophosphates have successfully enabled the lab-scale solid-state lithium–sulfur cells to achieve close-to-theoretical capacities. For applications requiring safe, energy-dense, lightweight batteries, solid-state lithium–sulfur batteries are an ideal choice that could surpass conventional lithium-ion batteries.Nevertheless, there are challenges specific to practical solid-state lithium–sulfur batteries, beyond the typical challenges inherent to solid-state batteries in general. While the conversion reaction of sulfur realizes a large specific capacity, the associated significant total volume changes of the active material results in contact losses among the cathode components and, consequently, decreases reversible capacity. Additionally, the ionically and electronically insulating active material requires composite formation with solid electrolytes and electron-conductive additives to secure sufficient ion and electron supply at a triple-phase boundary. However, the compositing process itself makes the carrier transport pathways very tortuous and requires the balancing of carrier transport and optimization of the attainable energy density. Lastly, the requirement of a high interfacial area to establish sufficient triple-phase boundaries promotes the degradation of the solid electrolytes, and the formation of less-conductive interphases further deteriorates the transport in the composites.This Account focuses on the challenges associated with developing practical solid-state lithium–sulfur batteries and provides an overview over recently developed concepts to tackle these critical challenges: (1) Introduction of the conversion efficiency to enable quantitative assessments of the impact of chemo-mechanical failure. (2) For long-term cycling, the electrolyte degradation at the interface and the electrochemical activity of the formed interphases come into play. Practical stability tests with increased interfacial areas and subsequently altered reversal potentials can quantify the magnitude of the electrolyte degradation and confirm influences of reversible redox activity of the interphases. (3) Monitoring the effective conductivity in the composites clarifies correlations between transport and cyclability, further highlighting the need of quantitative measurements to address the composite carrier transport. (4) Impedance spectroscopy combined with transmission-line model analysis as a function of applied potentials can visualize the stability window of good effective ion transport to utilize both the capacity contributions from redox-active interphases and the high ionic conductivity. In the end, a roadmap toward the practical solid-state lithium–sulfur batteries will be presented.

Inflation of Okmok Volcano During 2008–2020 From PS Analyses and Source Inversion With Finite Element Models

AbstractOkmok volcano, located on northeastern Umnak Island along the eastern end of the Aleutian island arc, is one of the most active volcanoes in Alaska, producing multiple eruptions in the past century. The most recent eruption, which occurred during July–August of 2008, was the most explosive since the early nineteenth century. In the years following the 2008 eruption, Global Navigation Satellite System (GNSS) and Interferometric Synthetic Aperture Radar (InSAR) observations indicate that Okmok has inflated at a variable rate of 40–195 mm/yr. In this study, we investigate the post‐eruptive deformation of Okmok (2008–2020) using InSAR and GNSS. L‐band ALOS‐2, C‐band Sentinel‐1/Envisat and X‐band TerraSAR‐X data are analyzed with Persistent Scatterer (PS) InSAR method. The deformation time series calculated from InSAR and GNSS are assimilated into finite element models using the Ensemble Kalman Filter to track the evolution of the magma system through time. The results indicate that the InSAR‐derived deformation history can be well explained by a spatially stable magmatic source located in the central caldera, at about 3 km beneath the sea level, which is also believed to be the same source that produced the 1997 and 2008 eruptions. Magma accumulation in the reservoir is about from 2008 to 2020, which is about 160% and about 60% of the total reservoir volume changes during the 1997 and the 2008 eruptions, respectively.

Evaluating XBeach performance for extreme offshore-directed sediment transport events on a dissipative beach

ABSTRACT The performance of the process-based nearshore model XBeach for predicting extreme offshore-directed sediment transport was investigated using field observations at a dissipative beach in Japan. Three extreme erosion events were identified from a record of 6,209 observations of the cross-shore profile change at Hasaki, Japan, from 1987 to 2003. The analysis considered the sensitivity of the wave nonlinearity of short waves that could be tuned using the parameter, fua , to the observed bed profile change. The comparisons revealed that for extreme offshore-directed sediment transport events, fua = 0.0 is the best fit for predicting these extreme beach profile changes. In the nearshore zone, erosion was underestimated, and the BSS exhibited low values. Peak sediment deposition occurred in the bar-offshore zone with sediments transported from the nearshore zone and was estimated by the model reasonably well. In addition to the three extreme events, 14 other large events were identified, and the trends of beach profile change could be estimated with sufficient tuning of the fua parameter. After analyzing the correlation between fua and wave and morphology-related parameters, the fua value could be correlated to the observed volume change. This suggested that if there were a rough estimate of the expected total volume change, this may help in setting fua value.

Combined GRACE and MT-InSAR to Assess the Relationship between Groundwater Storage Change and Land Subsidence in the Beijing-Tianjin-Hebei Region

Beijing-Tianjin-Hebei (BTH) has been suffering from severe groundwater storage (GWS) consumption and land subsidence (LS) for a long period. The overexploitation of groundwater brings about severe land subsidence, which affects the safety and development of BTH. In this paper, we utilized multi-frame synthetic aperture radar datasets obtained by the Rardarsat-2 satellite to monitor land subsidence’s temporal and spatial distribution in the BTH from 2012 to 2016 based on multi-temporal interferometric synthetic aperture radar (MT-InSAR). In addition, we also employed the Gravity Recovery and Climate Experiment (GRACE) mascon datasets acquired by the Center for Space Research (CSR) and Jet Propulsion Laboratory (JPL) to obtain the GWS anomalies (GWSA) of BTH from 2003 to 2016. Then we evaluate the accuracy of the results obtained. Furthermore, we explored the relationship between the regional GWSA and the average cumulative subsidence in the BTH. The total volume change of subsidence is 59.46% of the total volume change of groundwater storage. Moreover, the long-term decreasing trend of the GWSA (14.221 mm/year) and average cumulative subsidence (17.382 mm/year) show a relatively high consistency. Finally, we analyze the heterogeneity of GWS change (GWSC) and LS change (LSC) in the four typical areas by the Lorenz curve model. The implementation of the South-to-North Water Diversion Project (MSWDP) affects the heterogeneity of GWSC and LSC. It can be seen that the largest heterogeneity of LSC lags behind the GWSC in the Tianjin-Langfang-Hengshui-Baoding area. The largest uneven subsidence in Beijing and Tianjin occurred in 2015, and the largest uneven subsidence in Hengshui-Baoding occurred in 2014. After that, the heterogeneity of subsidence gradually tends to stable.

Morphological changes after cranial fractionated photon radiotherapy: Localized loss of white matter and grey matter volume with increasing dose

PurposeNumerous brain MR imaging studies have been performed to understand radiation-induced cognitive decline. However, many of them focus on a single region of interest, e.g. cerebral cortex or hippocampus. In this study, we use deformation-based morphometry (DBM) and voxel-based morphometry (VBM) to measure the morphological changes in patients receiving fractionated photon RT, and relate these to the dose. Additionally, we study tissue specific volume changes in white matter (WM), grey matter (GM), cerebrospinal fluid and total intracranial volume (TIV). Methods and materialsFrom our database, we selected 28 patients with MRI of high quality available at baseline and 1 year after RT. Scans were rigidly registered to each other, and to the planning CT and dose file. We used DBM to study non-tissue-specific volumetric changes, and VBM to study volume loss in grey matter. Observed changes were then related to the applied radiation dose (in EQD2). Additionally, brain tissue was segmented into WM, GM and cerebrospinal fluid, and changes in these volumes and TIV were tested. ResultsPerforming DBM resulted in clusters of dose-dependent volume loss 1 year after RT seen throughout the brain. Both WM and GM were affected; within the latter both cerebral cortex and subcortical nuclei show volume loss. Volume loss rates ranging from 5.3 to 15.3%/30 Gy were seen in the cerebral cortical regions in which more than 40% of voxels were affected. In VBM, similar loss rates were seen in the cortex and nuclei. The total volume of WM and GM significantly decreased with rates of 5.8% and 2.1%, while TIV remained unchanged as expected. ConclusionsRadiotherapy is associated with dose-dependent intracranial morphological changes throughout the entire brain. Therefore, we will consider to revise sparing of organs at risk based on future cognitive and neurofunctional data.