Duration Of Phase Research Articles

Video-Based Performance Analysis in Pituitary Surgery—Part 1: Surgical Outcomes

Endoscopic pituitary adenoma surgery has a steep learning curve, with varying surgical techniques and outcomes across centers. In other surgeries, superior performance is linked with superior surgical outcomes. This study aimed to explore the prediction of patient-specific outcomes using surgical video analysis in pituitary surgery. Endoscopic pituitary adenoma surgery videos from a single center were annotated by experts for operative workflow (3 surgical phases and 15 surgical steps) and operative skill (using modified Objective Structured Assessment of Technical Skills [mOSATS]). Quantitative workflow metrics were calculated, including phase duration and step transitions. Poisson or logistic regression was used to assess the association of workflow metrics and mOSATS with common inpatient surgical outcomes. 100 videos from 100 patients were included. Nasal phase mean duration was 24minutes and mean mOSATS was 21.2/30. Mean duration was 34minutes and mean mOSATS was 20.9/30 for the sellar phase, and 11minutes and 21.7/30, respectively, for the closure phase. The most common adverse outcomes were new anterior pituitary hormone deficiency (n= 26), dysnatremia (n= 24), and cerebrospinal fluid leak (n= 5). Higher mOSATS for all 3 phases and shorter operation duration were associated with decreased length of stay (P= 0.003 &P < 0.001). Superior closure phase mOSATS were associated with reduced postoperative cerebrospinal fluid leak (P < 0.001), and superior sellar phase mOSATS were associated with reduced postoperative visual deterioration (P= 0.041). Superior surgical skill and shorter surgical time were associated with superior surgical outcomes, at a generic and phase-specific level. Such video-based analysis has promise for integration into data-driven training and service improvement initiatives.

Intraoperative Fluorescent Navigation of the Ureters, Vessels, and Nerves during Robot-Assisted Sacrocolpopexy.

In this study, we aimed to demonstrate the feasibility and safety of navigating the ureters, middle sacral artery (MSA), and superior hypogastric nerve (SHN) using indocyanine green (ICG) and near-infrared fluorescence (NIRF) imaging during robot-assisted sacrocolpopexy (RSCP). Overall, 15 patients who underwent RSCP for apical vaginal prolapse were retrospectively enrolled. All patients underwent cystoscopic intraureteric instillation of 5 cc ICG (2.5 mg/mL) before RSCP and intravenous injection of 3 cc ICG during presacral dissection and mesh fixation. In all patients, the fluorescent right ureter was clearly identified in real time. The MSA was visualized on ICG-NIRF images in 80% (13/15) of patients. The mean time from ICG injection to MSA visualization was 43.7 s; the mean duration of the arterial phase was 104.3 s. Fluorescent SHN was detected in 73.3% (11/15) of patients. The time from ICG injection to SHN fluorescence was 48.4 s; the duration of fluorescence was 177.2 s. There was no transfusion, iatrogenic ureteral injury, or bowel or urinary dysfunction. Our results indicated that intraoperative ureter, MSA, and SHN mapping using ICG-NIRF images during RSCP is a valuable and safe technique to avoid iatrogenic ureteral, vascular, and neural injuries and to simplify surgical procedures. Nonetheless, further studies are required.

Impact of main sequence mass loss on the appearance, structure, and evolution of Wolf-Rayet stars

Context. Stellar winds are one of the most important drivers of massive star evolution and are a vital source of chemical, mechanical, and radiative feedback on the galactic scale. Despite its significance, mass loss remains a major uncertainty in stellar evolution models. In particular, the interdependencies between the different approaches and the subsequent evolutionary stages and predicted observable phenomena are far from being systematically understood. Aims. In this study, we examine the impact of main sequence mass loss on the structure of massive stars throughout their entire evolution. Particular focus is placed on the consequences in terms of entrance into the Wolf-Rayet (WR) regime and the subsequent evolution. Methods. Using the Geneva stellar evolution code (GENEC), we computed grids of single, nonrotating stellar models at solar and Large Magellanic Cloud (LMC) metallicities of initial masses between 20 and 120 solar masses, with two representative prescriptions for high and low main sequence mass loss. Results. We obtain detailed numerical predictions regarding the structure and evolution of massive stars, and infer the role of main sequence mass loss by comparison of the mass-loss rate prescriptions. We present implications for the overall evolutionary trajectory, including the evolution of WR stars, as well as the effect on stellar yields and stellar populations. Conclusions. Mass loss during the main sequence plays an important role because of its ability to affect the sequence and duration of all subsequent phases. We identify several distinct evolutionary paths for massive stars, which are significantly influenced by the chosen main sequence mass-loss description. We also discuss the impact of uncertainties – other than that regarding mass loss – on the evolution, in particular those relating to convection. We further demonstrate that not only the total mass loss but also the specific mass-loss history throughout a star’s life is a crucial determinant of many aspects, such as the resulting stellar yields.

Gait phase normalization resolves the problem of different phases being compared in gait cycle normalization

For time-continuous analysis of gait, the problem of variations in cycle durations is resolved by normalizing to the gait cycle, but results depend on the definition of the cycle start. Gait cycle normalization ignores variations in gait phase durations, which results in averaging and comparing data across different phases. We propose gait phase normalization as part of a comprehensive method for independently analyzing magnitude and timing differences. First, gait phases are identified and differences in absolute and/or relative timing of phase durations or any point of interest between conditions or groups are analyzed using standard statistics. Next, time-continuous gait data is normalized to gait phases, and statistical parametric mapping (SPM) is used to assess magnitude differences in gait data. This approach is demonstrated on data recorded from ten young healthy adults walking on a treadmill at five different speeds. Sagittal knee angle was normalized to gait cycle or gait phase using five different gait cycle start events. Walking at different speeds resulted in significant changes in gait phase durations, highlighting a problem ignored by gait cycle normalization. SPM results for knee angle normalized to gait cycle varied from normalization to gait phases. Gait phase normalized SPM results were robust to the definition of the cycle start, in contrast to gait cycle normalized data. The approach of analyzing phase durations and normalizing data to gait phases overcomes previous limitations and enables a comprehensive analysis of magnitude and timing differences in time-continuous gait data and could be readily adapted to other tasks.

Physiological Response to the COVID-19 Vaccine: Insights From a Prospective, Randomized, Single-Blinded, Crossover Trial.

Rapid development and implementation of vaccines constituted a crucial step in containing the COVID-19 pandemic. A comprehensive understanding of physiological responses to these vaccines is important to build trust in medicine. This study aims to investigate temporal dynamics before and after COVID-19 vaccination in 4 physiological parameters as well as the duration of menstrual cycle phases. In a prospective trial, 17,825 adults in the Netherlands wore a medical device on their wrist for up to 9 months. The device recorded their physiological signals and synchronized with a complementary smartphone app. By means of multilevel quadratic regression, we examined changes in wearable-recorded breathing rate, wrist skin temperature, heart rate, heart rate variability, and objectively assessed the duration of menstrual cycle phases in menstruating participants to assess the effects of COVID-19 vaccination. The recorded physiological signals demonstrated short-term increases in breathing rate and heart rate after COVID-19 vaccination followed by a prompt rebound to baseline levels likely reflecting biological mechanisms accompanying the immune response to vaccination. No sex differences were evident in the measured physiological responses. In menstruating participants, we found a 0.8% decrease in the duration of the menstrual phase following vaccination. The observed short-term changes suggest that COVID-19 vaccines are not associated with long-term biophysical issues. Taken together, our work provides valuable insights into continuous fluctuations of physiological responses to vaccination and highlights the importance of digital solutions in health care. RR2-10.1186/s13063-021-05241-5.

Mechanisms of a novel regulatory light chain-dependent cardiac myosin inhibitor.

Hypertrophic cardiomyopathy (HCM) is a genetic disease of the heart characterized by thickening of the left ventricle (LV), hypercontractility, and impaired relaxation. HCM is caused primarily by heritable mutations in sarcomeric proteins, such as β myosin heavy chain. Until recently, medications in clinical use for HCM did not directly target the underlying contractile changes in the sarcomere. Here, we investigate a novel small molecule, RLC-1, identified in a bovine cardiac myofibril high-throughput screen. RLC-1 is highly dependent on the presence of a regulatory light chain to bind to cardiac myosin and modulate its ATPase activity. In demembranated rat LV trabeculae, RLC-1 decreased maximal Ca2+-activated force and Ca2+ sensitivity of force, while it increased the submaximal rate constant for tension redevelopment. In myofibrils isolated from rat LV, both maximal and submaximal Ca2+-activated force are reduced by nearly 50%. Additionally, the fast and slow phases of relaxation were approximately twice as fast as DMSO controls, and the duration of the slow phase was shorter. Structurally, x-ray diffraction studies showed that RLC-1 moved myosin heads away from the thick filament backbone and decreased the order of myosin heads, which is different from other myosin inhibitors. In intact trabeculae and isolated cardiomyocytes, RLC-1 treatment resulted in decreased peak twitch magnitude and faster activation and relaxation kinetics. In conclusion, RLC-1 accelerated kinetics and decreased force production in the demembranated tissue, intact tissue, and intact whole cells, resulting in a smaller cardiac twitch, which could improve the underlying contractile changes associated with HCM.

Chlorella vulgaris cold preservation (4∘C) as a means to stabilize biomass for bioreactor inoculation: A six-month study

Chlorella vulgaris cells were maintained over six months (or tentatively) using three protocols: two-week subculturing (positive control), storage at 4∘C, and simple abandonment (negative control). Cultures were monitored by their optical and cell densities over the trial period. Cells were characterized by their size, pigment profile, photosystem II status (OJIP test), electron transport rate assay (light curve), and lag phase duration when regrown. The abandoned cultures quickly showed cells deviating from their nominal state (increased size, a loss of their pigments, a negative alteration of their photosynthetic capacity, and an extended lag phase when inoculated into fresh medium). Frequent subculturing yielded reasonably stable performances. Yet, our experience showed that uncontrollable factors (human errors, lack of communication between teams) could expose the cultures to unfortunate incidents. 4∘C preservation allowed the cells to have a constant size and a slightly increased, yet stable, pigment profile associated to a dark acclimation (+12 % total chlorophyll). Finally, regrowth tests demonstrated that 4∘C preservation induces slightly improved performance (lag phase duration reduced by 9.5 %) than frequent subculturing. Those findings advocate for the use of 4∘C preservation to reduce cell maintenance work and conserve a pool of cells in a similar state to be used as repeatable inoculum for larger-scale experiments while nullifying otherwise batch-to-batch variation effects. Subculturing work can be reduced from once every two weeks to once every six months at least.

Reproductive resilience of growth and nitrogen uptake underpins yield improvement in winter wheat with forced delay of sowing

Winter wheat production is influenced by climate extremes worldwide. Heavy precipitation induced delay of sowing generates limited photothermal resources for wheat early growth. However, how wheat build resilience from stunted seedling growth has not been fully explored. Here, a twelve-year farmers' survey of wheat yield was recorded and four-year field experiments of wheat grown in normal and late-sowing were performed under zero nitrogen (N0) and optimum nitrogen (Opt.N) supply. Wheat growth and N uptake were measured at both vegetative and reproductive stages alongside photothermal resource-use efficiency. Farmers' survey showed 10.4 % yield losses due to delayed sowing compared to the normal. However, four-year field trials revealed that the combination of increasing seeding rates and Opt.N application recovered grain yield of sowing-delayed wheat and even increased by 13.2 % compared to plants in the normal seasons. Although delayed sowing substantially suppressed seedling growth and tillering before winter dormancy, the Opt.N application increased spring tillers by 2.4-fold which were productive at maturity. Further, plant growth and N uptake from jointing to anthesis of sowing-delayed wheat were accelerated by Opt.N, but not by N0 treatment. Delayed sowing significantly shortened the duration of lag phase of grain filling by 3.5 days and by 183 growing degree days compared with the normal, which initiated the linear and fast filling earlier. Increased leaf photosynthesis by 27.4 % during grain filling further supported the fast recovery of grain filling in the sowing-delayed wheat. Concomitantly, the physiological N-use efficiency increased by 46.7 % during grain filling and by 41.5 % at maturity by enhancing N availability and seeding rates, and photothermal resource-use efficiency increased by 1.3- to 1.7-fold for wheat with delayed vs. normal sowing. Overall, these findings highlight the integrated management of nutrient and cultivation to mitigate the impacts of climate extremes on crop productivity through building plant reproductive resilience.

Stress wave effects and their mechanisms on stress-strain curves in the elastic phase of SHPB tests

In Split Hopkinson Pressure Bar (SHPB) tests, the stress wave effects during the elastic phase of the stress-strain curve and their influence mechanisms are crucial. Due to the extremely short duration of the elastic deformation phase, the stress wave effects on the specimen during this stage cannot be ignored. This leads to significant errors in the obtained elastic stress-strain curves. However, the dynamic compressive elastic stress-strain relationship forms the basis for studying the viscoelastic behavior of materials. Accurate determination of elastic yield stress and yield strain is also essential for deriving accurate plastic stress-strain relationships. Quantitative research on the stress wave effects during the elastic compression phase of SHPB tests is fundamental for decoupling and obtaining accurate material elastic curves. This paper conducts a quantitative theoretical analysis of the structural effects caused by stress wave evolution during the elastic compression phase, based on the assumption of plane waves. It studies the deviation characteristics and main factors of the phenomenological engineering stress-strain curves of the specimen compared to the actual material stress-strain curves under different conditions, revealing the influence rules and mechanisms of this deviation. The maximum stress deviation value and its corresponding dimensionless time, as well as the variation trend of the maximum stress deviation value within different fluctuation intervals, are calculated. Additionally, the study investigates the cases where the incident wave is arc-shaped or a combination of arc and linear waves. The findings provide theoretical references for the precise design and accurate data processing of SHPB tests.

Assessing the net financial benefits of employing digital endpoints in clinical trials.

In the last few decades, developers of new drugs, biologics, and devices have increasingly leveraged digital health technologies (DHTs) to assess clinical trial digital endpoints. To our knowledge, a comprehensive assessment of the financial net benefits of digital endpoints in clinical trials has not been conducted. We obtained data from the Digital Medicine Society (DiMe) Library of Digital Endpoints and the US clinical trials registry, ClinicalTrials.gov. The benefit metrics are changes in trial phase duration and enrollment associated with the use of digital endpoints. The cost metric was obtained from an industry survey of the costs of including digital endpoints in clinical trials. We developed an expected net present value (eNPV) model of the cash flows for new drug development and commercialization to assess financial value. The value measure is the increment in eNPV that occurs when digital endpoints are employed. We also calculated a return on investment (ROI) as the ratio of the estimated increment in eNPV to the mean digital endpoint implementation cost. For phase II trials, the increase in eNPV varied from $2.2 million to $3.3 million, with ROIs between 32% and 48% per indication. The net benefits were substantially higher for phase III trials, with the increase in eNPV varying from $27 million to $40 million, with ROIs that were four to six times the investment. The use of digital endpoints in clinical trials can provide substantial extra value to sponsors developing new drugs, with high ROIs.

Two‐stage algorithm for traffic signal optimization and web‐service system development

AbstractEfficient control of traffic signals for vehicles and pedestrians at intersections is critical for relieving traffic congestion. Considering the unique characteristics of intersections, such as the number of roads, the presence or absence of crosswalks, road geometric shapes, and traffic demand patterns, an appropriate phase sequence and duration for traffic signals must be established at each intersection. This paper proposes a simulation‐based two‐stage algorithm comprising integer‐constrained Adam (ICA) and tabu search (TS) to optimize the phase sequence and duration for arbitrary intersections with arbitrary traffic‐demand patterns. The ICA promptly identifies a promising region in which a global optimal solution is likely to be obtained, whereas TS determines the best solution near the region. The performance of the proposed algorithm that optimizes phase durations with fixed phase sequence is evaluated against several baseline methods using 24 instances across six actual intersections. Experimental results show that the proposed algorithm reduces the average travel time by 20.2% compared with existing traffic signals within a computation time of 4 min, thus providing a near‐optimal solution eight times faster than commonly used population‐based metaheuristics. Furthermore, the algorithm demonstrates robust performance across heterogeneous vehicles and recommends the best phase sequence that effectively alleviates congestion in current traffic signal systems. The optimized phase sequence with best phase durations further reduces the average travel time by approximately 11.3% compared with the existing phase sequence with best phase durations at an actual intersection. To facilitate its widespread use, a free, open web‐service system named “Smart Intersection for Traffic Efficiency” is developed, which enables users to optimize traffic signal systems without requiring optimization background or simulation knowledge.

The effect of probiotic supplementation on sleep, depression-like behaviour, and central glucose and lactate metabolism in male and female pubertal mice exposed to chronic sleep disruption

The prevalence of depression significantly increases during puberty and adolescence. Puberty is the period during which sexual maturity is attained, while adolescence persists beyond puberty and includes physiological, social, emotional, and cognitive maturation. A stressor that has been shown previously to induce depression is chronic sleep disruption. Probiotics can prevent stress-induced depression. However, it was unclear whether probiotics could prevent depression following chronic sleep disruption and what mechanism may be involved. Therefore, we investigated whether pubertal probiotic treatment could prevent depression-like behavior in mice following chronic sleep disruption. We also examined whether probiotic treatment could improve sleep quality, and increase serotonin, tryptophan, glucose, and L-lactate concentrations in chronically sleep-disrupted mice. We hypothesized that probiotic treatment would prevent depression-like behavior, improve sleep quality, and increase serotonin, tryptophan, glucose, and L-lactate concentrations in sleep-disrupted mice. Male and female mice (N=120) received cannula and electroencephalogram (EEG) electrode implants at postnatal day (PND) 26. Mice received Lacidofil® or Cerebiome® probiotics (PND 33–51) and were sleep-disrupted for the first 4 hours of the light phase (sleep period) (PND 40–51). Hippocampal L-lactate and glucose concentrations and sleep were measured over a 24-h period (PND 48–49). Depression-like behaviour was evaluated using tail suspension (PND 49) and forced swim tests (PND 50). Chronic sleep disruption increased depression-like behaviour and NREM duration in the dark phase, and reduced all metabolites and neuromodulating biomolecules measured within the brain. However, mice treated with probiotics did not display depression-like behaviour or decreased hippocampal L-lactate following chronic sleep disruption. Cerebiome prevented decreases to prefrontal serotonin and hippocampal glucose concentrations, while Lacidofil increased NREM duration in the latter half of the light phase. The current study not only replicates previous findings linking chronic sleep disruption to depression, but also demonstrates that pubertal probiotic treatment can mitigate the effects of chronic sleep disruption on depression-like behaviour and on the neural mechanisms underlying depression in a strain-dependent manner.

Appendicectomy pathway: Insights from electronic medical records of a local health district in Australia

BackgroundThis study aims to identify the common pathways of appendicectomy, the most common emergency surgery in Australia’s public hospitals and any variations within a regional public health district in New South Wales, Australia. MethodsWe analyzed the electronic medical records of 3,943 patients who underwent appendicectomy between January 2014 and July 2020 at 2 hospitals in the Illawarra Shoalhaven Local Health District, New South Wales, Australia, using the PM2 approach for surgical pathway identification and subsequent statistical analyses. ResultsAmong 3,943 patients, 3,606 (91.5%) followed an 11-step main pathway: (1) emergency department admission, (2) surgery booking, (3) anesthesia start, (4) operating room entry, (5) surgery start, (6) surgery end, (7) anesthesia end, (8) operating room discharge, (9) postanesthesia care unit admission, (10) postanesthesia care unit discharge, and (11) hospital discharge. The median length of stay was 48.13 hours (interquartile range 32.74). The main pathway differed from either variation 1 (n = 246, 6.2%) or variation 2 (n = 30, 0.8%) only in the timing and location of anesthesia administration or conclusion. Variation 3 (n = 26, 0.7%) included patients who underwent appendicectomy twice, whereas variation 4 (n = 25, 0.6%) included patients booked for surgery before emergency department admission through community doctor referrals. Thirteen exceptional cases experienced combinations of the aforementioned pathways. The length of stay and phase durations varied between the main pathway and these variations. ConclusionThe appendicectomy pathway was largely standardized across the studied hospitals, with the location of anesthesia administration or conclusion affecting specific stages but not the overall length of stay. Only a complex 2-surgery pathway increased length of stay.

Associations between fetal position at delivery and duration of active phase of labor: A historical cohort study.

In clinical experience, occiput posterior (OP) position is associated with longer labor duration than occiput anterior (OA) position, but few studies have investigated the association between labor duration and fetal position. We aimed to compare duration of the active phase of labor in OP deliveries with OA deliveries in a contemporary population using survival methods. Secondary aims were to compare the frequencies of operative interventions, obstetric anal sphincter injuries (OASIS), postpartum hemorrhage, and newborn outcomes in OP with OA deliveries. We did a historical cohort study in three university hospitals in Norway from 2012 to 2022. Women with a single fetus in cephalic presentation, no previous cesarean section and gestational age ≥37 weeks were eligible and stratified into the first four groups of the Robson ten-group classification system (TGCS). We estimated the mean duration and calculated the hazard ratio (HR) for delivery using survival analyses. Cesarean sections and instrumental vaginal deliveries were censored. The study population comprised 112 019 women, 105 571 (94.2%) were delivered in OA and 6448 (5.8%) in OP position. The estimated mean duration of the active phase of labor was longer in women with the fetus in OP position in all four TGCS groups. The estimated duration was longer in the OP groups in analyses stratified with respect to epidural analgesia and oxytocin augmentation. The graphical abstract illustrates the probability of delivery in OP compared with OA position in merged TGCS groups 1 and 2a, as a function of time. The unadjusted HR was 0.33 (95% CI 0.31-0.36) for fetuses delivered in OP position compared with OA position in TGCS group 1, 0.25 (95% CI 0.21-0.27) in group 2a, 0.70 (95% CI 0.67-0.73) in group 3, and 0.61 (95% CI 0.55-0.67) in group 4a, respectively. Neither maternal age, gestational age, BMI nor birthweight had confounding effect. Operative delivery rates and OASIS rates were higher in OP position in all four groups. We found longer duration of the active phase of labor in women with the fetus delivered in OP position in all four TGCS groups.

Experimental Protocols Used to Mimic Gastrointestinal Protein Digestion: A Systematic Review.

Bioactive peptides derived from native proteins modulate physiological processes in the metabolic pathways. Given that multiple protocols in the literature mimic the digestion of dietary components, gathering studies that use such models directed at protein digestion processes is critical. This systematic review aimed to gather evidence that adopted adequate experimental models to simulate human protein digestion. The databases searched were PubMed, Web of Science, ScienceDirect, Embase, Virtual Health Library, and Scopus. A total of 1985 articles were found, resulting in 20 eligible in vitro studies. The Office of Health Assessment and Translation was used to evaluate methodological quality. Seven studies used plant-based protein sources, twelve used animal protein sources, and one used both. The duration of the oral phase varied, although 60% of the studies employed a protein digestion period of 120 min. Amylase, pepsin, and pancreatin enzymes were utilized in 40% of the studies, with pH levels of 7, 3, and 7, respectively, during the oral, gastric, and intestinal phases. The INFOGEST harmonized static model was adopted by 65% of the studies; INFOGEST is the most effective model for simulating gastrointestinal protein processes in humans and can be used to answer several research questions because it describes experimental conditions close to the human physiological situation.

A Comprehensive Classification and Analysis of Geomagnetic Storms Over Solar Cycle 24

A geomagnetic storm is a global disturbance of Earth's magnetosphere, occurring as a result of the interaction with magnetic plasma ejected from the Sun. Despite considerable research, a comprehensive classification of storms for a complete solar cycle has not yet been fully developed, as most previous studies have been limited to specific storm types. This study, therefore, attempted to present complete statistics for solar cycle 24, detailing the occurrence of geomagnetic storm events and classifying them by type of intensity (moderate, intense, and severe), type of complete interval (normal or complex), duration of the recovery phase (rapid or long), and the number of steps in the storm's development. The analysis was applied to data from ground-based magnetometers, which measured the Dst index as provided by the World Data Center for Geomagnetism, Kyoto, Japan. This study identified 211 storm events, comprising moderate (177 events), intense (33 events), and severe (1 event) types. About 36% of ICMEs and 23% of CIRs are found to be geoeffective, which caused geomagnetic storms. Up to four-step development of geomagnetic storms was exhibited during the main phase for this solar cycle. Analysis showed the geomagnetic storms developed one or more steps in the main phase, which were probably related to the driver that triggered the geomagnetic storms. A case study was additionally conducted to observe the variations of the ionospheric disturbance dynamo (Ddyn) phenomenon that resulted from the geomagnetic storm event of 2015 July 13. The attenuation of the Ddyn in the equatorial region was analyzed using the H component of geomagnetic field data from stations in the Asian sector (Malaysia and India). The variations in the Ddyn signatures were observed at both stations, with the TIR station (India) showing higher intensity than the LKW station (Malaysia).

Temporal effect and evolution mechanism of sand-bentonite mixture liner swelling under the influence of sand and diesel

To elucidate the time-dependent swelling behavior of landfill sand-bentonite mixture liners under the effect of organic pollutants, an no loading swelling ratio test was conducted on mixtures with varying sand and diesel content. The evolution characteristics of the swelling time curve morphology were investigated. The micro-mechanisms underlying the swelling time effect evolution were explored. The results indicated that the sand-diesel interaction significantly altered the swelling time curve morphological characteristics of the mixture. As the sand content increased, the swelling coefficient at the stable state decreased. However, during the rapid swell phase, diesel-contaminated mixed soil does not exhibit the increase-then-decrease pattern in swell coefficient seen in unpolluted mixed soil. The duration of both the slow swelling phase and the time to reach a stable state were longer. Mechanistic analysis revealed that cation exchange capacity is insufficient to effectively analyze the evolution characteristics of the swelling time curve. Instead, the initial swelling potential of bentonite is the true indicator of the mixture’s swelling properties. The particle size distribution influences the changes in the swelling coefficient during the rapid swelling phase, but diesel alters the particle size distribution, mitigating its impact. The oil sealing effect within intra-aggregate and inter-aggregate pores not only weakened the swelling characteristics of the mixture at all stages but also increased the permeability resistance, thereby reducing the duration of the rapid swelling phase and extending the slow swelling and stable swelling phases.

Clinical impact of a dose-escalation strategy for lenvatinib in differentiated thyroid cancer.

Treatment options for patients with differentiated thyroid cancer (DTC) who experience disease progression on lenvatinib treatment are limited. Although dose escalation of treatment with tyrosine kinase inhibitors at disease progression has been reported across cancer types, clinical significance in patients with DTC has not been investigated. We retrospectively reviewed patients with DTC who experienced disease progression on lenvatinib treatment from September 2011 to June 2022. We compared subjects who received dose-escalation treatment with standard treatment of termination at the time of initial disease progression. The escalated dose was decided by referencing to the previous effective and tolerated dose. Thirty-three patients were identified, 15 with dose escalation and 18 with lenvatinib termination. In both groups, the starting dose of lenvatinib was 24mg/day, and the median dose at initial disease progression was 10mg/day. In the former, the median dose escalation was 6mg/day (range: 4-12). Objective response rate, clinical benefit rate by escalation, and median treatment duration of the dose-escalation phase were 13.3%, 73.3%, and 9.9months (95% confidence interval [CI] 5.71-27.6), respectively. Median overall survival from initial disease progression was significantly longer in the dose-escalation group (median OS: 20.4months [95% CI 7.0-NA] vs. 3.9months [95% CI 1.7-7.9], log-rank p-value; 0.0004, hazard ratio; 0.22 [95% CI 0.09-0.55]). There were no grade 5 adverse events, and one patient discontinued due to a grade 3 lung abscess. The dose-escalation strategy appears to be a safe and effective treatment option after disease progression in patients treated with lenvatinib for DTC.

Non-conductive silicon-containing materials improve methane production by pure cultures of methanogens

Conductive materials (CM) enhance methanogenesis, but there is no clear correlation between conductivity and faster methane production (MP) rates. We investigated if MP by pure cultures of methanogens (Methanobacterium formicicum, Methanospirillum hungatei, Methanothrix harundinacea and Methanosarcina barkeri) is affected by CM (activated carbon (AC), magnetite), and other sustainable alternatives (sand and glass beads, without conductivity, and zeolites (Zeo)). The significant impact of the materials was on M. formicicum as MP was significantly accelerated by non-CM (e.g., sand reduced the lag phase (LP) duration by 48 %), Zeo and AC (LP reduction in 71% and 75 %, respectively). Conductivity was not correlated with LP reduction. Instead, silicon content in the materials was inversely correlated with the time required for complete MP, and silicon per se stimulated M. formicicum’s activity. These findings highlight the potential of using non-CM silicon-containing materials in anaerobic digesters to accelerate methanogenesis.

Degradation Kinetics of Antifouling Biocides in Sediment During the Spiking Equilibrium Phase

The new generation of antifouling biocides, as well as other emerging contaminants, has not yet been included in sediment quality guidelines or present standard protocols for sediment spiking. Most of these biocides have short half-lives in water, but little information is available regarding their degradation in sediments. Thus, there is a need to establish a reliable duration of the equilibrium phase for sediment spiking prior to sediment toxicity testing to determine the actual exposure concentrations during ecotoxicological tests. This study aimed to evaluate the degradation of DCOIT, Irgarol, Diuron, and Dichlofluanid during a spiking equilibrium phase of 24 h at three different time intervals (0, 6, and 24 h) and concentrations (10, 100, and 1000 ng g-1), by applying kinetic degradation models. The models presented a better fit for the 1000 ng g-1 treatments, in which the half-lives of DCOIT and Diuron were &lt; 5 h, Dichlofluanid &lt; 2 h, and Irgarol &lt; 6h. Our results also indicate that, except for Dichlofluanid, the degradation rates of the other antifouling biocides were reduced dramatically after 6 h of equilibrium. Therefore, an equilibrium phase of 24 h (or greater than 6 h) was considered viable for sediment spiking. Our findings provide valuable information to guide future sediment toxicity tests using these compounds.