239 research outputs found

    Effect of carbonation on eco-friendly binders for marine infrastructures

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    This research examines the effects of carbonation on various binders— CEM I (Ordinary Portland Cement), CEM III (a slag cement containing ground granulated blast furnace slag), and calcium sulfoaluminate (CSA) cement— focusing on their potential as sustainable materials for artificial reefs. Mechanical properties, leaching, and mineralogical changes were evaluated under accelerated carbonation and subsequent exposure to artificial seawater for 91 days. Results show that carbonation significantly reduces the surface pH of the binders, indicating alterations in chemical properties. X-ray Diffraction (XRD) analysis reveals that carbonation transforms Ca(OH)₂ by forming CaCO₃, enhancing material durability and reducing Ca(OH)₂ content. Compressive strength tests indicate that CEM III with 25 % recycled concrete fines achieved the highest strength of 69.9 MPa after carbonation, outperforming CEM I and CSA. Despite having the lowest compressive strength (42.5 MPa), carbonated CSA samples demonstrated the highest oyster settlement density (0.0408 oysters/cm²), likely due to the breakdown of ettringite during carbonation, forming carbonates, calcium sulfates, and alumina. Additionally, CEM I and CEM III exhibited significant calcium leaching over time, resulting in strength loss, which surface carbonation mitigated. The surface carbonation-induced pH reduction and calcium carbonate formation suggest a favorable environment for optimal oyster settlement. These findings highlight the potential of carbonated eco-friendly binders as sustainable solutions for artificial reefs, offering environmental and structural benefits.</p

    Recurrent differentiated thyroid cancer: Towards personalized treatment based on evaluation of tumor characteristics with PET (THYROPET Study): Study protocol of a multicenter observational cohort study

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    Background: After initial treatment of differentiated thyroid carcinoma (DTC) patients are followed with thyroglobulin (Tg) measurements to detect recurrences. In case of elevated levels of Tg and negative neck ultrasonography, patients are treated 'blindly' with Iodine-131 (131I). However, in up to 50% of patients, the post-therapy scan reveals no 131I-targeting of tumor lesions. Such patients derive no benefit from the blind therapy but are exposed to its toxicity. Alternatively, iodine-124 (124I) Positron Emission Tomography/Computed Tomography (PET/CT) has become available to visualize DTC lesions and without toxicity. In addition to this, 18F-fluorodeoxyglucose (18F-FDG) PET/CT detects the recurrent DTC phenotype, which lost the capacity to accumulate iodine. Taken together, the combination of 124I and 18F-FDG PET/CT has potential to stratify patients for treatment with 131I.Methods/Design: In a multicenter prospective observational cohort study the hypothesis that the combination of 124I and 18F-FDG PET/CT can avoid futile 131I treatments in patients planned for 'blind' therapy with 131I, is tested.One hundred patients planned for 131I undergo both 124I and 18F-FDG PET/CT after rhTSH stimulation. Independent of the outcome of the scans, all patients will subsequently receive, after thyroid hormone withdrawal, the 131I therapy. The post 131I therapeutic scintigraphy is compared with the outcome of the 124I and 18F-FDG PET/CT in order to evaluate the diagnostic value of the combined PET modalities.This study primary aims to reduce the number of futile 131I therapies. Secondary aims are the nationwide introduction of 124I PET/CT by a quality assurance and quality control (QA/QC) program, to correlate imaging outcome with histopathological features, to compare 124I PET/CT after rhTSH and after withdrawal of thyroid hormone, and to compare 124I and 131I dosimetry.Discussion: This study aims to evaluate the potential value of the combination of 124I and 18F-FDG PET/CT in the prevention of futile 131I therapies in patients with biochemically suspected recurrence of DTC. To our best knowledge no studies addressed this in a prospective cohort of patients. This is of great clinical importance as a futile 131I is a costly treatment associated with morbidity and therefore should be restricted to those likely to benefit from this treatment.Trial registration: Clinicaltrials.gov identifier: NCT01641679

    Localization of parathyroid adenomas using 11C-methionine pet after prior inconclusive imaging

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    Purpose: Minimally invasive parathyroidectomy (MIP) is the recommended treatment in primary hyperparathyroidism (pHPT) for which accurate preoperative localization is essential. The current imaging standard consists of cervical ultrasonography (cUS) and MIBI-SPECT/CT. 11C-MET PET/CT has a higher resolution than MIBI-SPECT/CT. The aim of this study was to determine the diagnostic performance of 11CMET PET/CT after initial inconclusive or negative localization.  Methods: We performed a retrospective single center cohort study of patients with pHPT undergoing parathyroid surgery after prior negative imaging and later localization by means of 11C-MET PET/CT between 2006 and 2014. Preoperative localization by 11C-MET PET/CT was compared with later surgical localization, intraoperative quick PTH (IOPTH), duration of surgery, histopathology, and follow-up data. Also, differences in duration of surgery between the groups with and without correct preoperative localization were analyzed.  Results: In 18/28 included patients a positive 11C-MET-PET/CT result corresponded to the surgical localized adenoma (64%). In 3/28 patients imaging was false positive and no adenoma was found. In 7/28 patients imaging was false negative at the side of the surgically identified adenoma. Sensitivity of 11C-MET PET/ CT was 72% (18/25). Duration of surgery of correctly localized patients was significantly shorter compared to falsely negative localized patients (p = 0.045).  Conclusion: In an intention to treat 11C-MET-PET/CT correctly localized the parathyroid adenoma in 18/28 (64%) patients, after previous negative imaging. A preoperatively correct localized adenoma leads to a more focused surgical approach (MIP) potentially reducing duration of surgery and potentially healthcare costs

    Single-Arm, Open-Label, Multicenter Study to Evaluate the Safety and Performance of Dura Sealant Patch in Reducing Cerebrospinal Fluid Leakage Following Elective Cranial Surgery: The ENCASE Trial Study Protocol

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    Cerebrospinal fluid (CSF) leakage is one of the most common neurosurgical complications, occurring in 4% to 32% of surgical cases, with a higher incidence in complicated skull base surgery, intradural spine surgery, and the surgery of the posterior fossa. Our group developed a Dural Sealant Patch (DSP) for watertight dural closure after cranial surgery. OBJECTIVE: To clinically study for the first time the safety and performance of the DSP as a means of reducing CSF leakage in patients undergoing elective cranial intradural surgery with a dural closure procedure. METHODS: We will conduct an open-label, single-arm, multicenter study with a 360 d (12 mo) follow-up. A total of 40 patients will be enrolled at 3 sites. The primary endpoint is a combination of occurrences of one of the following events: postoperative percutaneous CSF leakage, intraoperative leakage at 20 cm H2O, or postoperative wound infection. The secondary endpoints are pseudomeningocele and thickness of dura + DSP. EXPECTED OUTCOMES: Not more than 3 patients will meet the primary endpoint suggesting safety and efficacy. DISCUSSION: As a next step, a randomized controlled trial against the best current practice will follow to evaluate if DSP reduces CSF leakage while its safety is noninferior

    Monitoring of Executive Functions During Awake Glioma Surgery:A Standardized Multicenter Protocol

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    BACKGROUND AND OBJECTIVES:Currently, there are no standardized clinical mapping protocols for monitoring of executive functions during awake glioma surgery, primarily due to a lack of evidence-based data for cognitive mapping. By aligning procedures and documentation practices across institutions, clinicians can overcome the current fragmentation in the field and iteratively work toward generating reproducible, high-quality Data sets that will better clarify the clinical relevance of white matter pathways involved in executive functions. A previously conducted pilot study led to the development of a standardized monitoring protocol and demonstrated that pooling of data is feasible when surgical teams commit to the study requirements. The primary goal of this multicenter study protocol is to investigate whether using this standardized protocol can identify white matter tracts involved in executive functions.METHODS:In this prospective, clinical observational study, we will continue data collection in 4 neurosurgical departments from the previously conducted pilot study and expand to other hospitals providing neurosurgical care. We aim to include adult patients that will undergo awake primary glioma surgery and undergo monitoring of executive functions with a uniform set of tasks for the following white matter tracts: frontal aslant tract, superior longitudinal fasciculus II and II, arcuate fasciculus, inferior fronto-occipital fasciculus. Data will be collected in a standardized manner for each patient before, during, and after surgery.EXPECTED OUTCOMES:The primary objective of this study was to determine if executive functions can be effectively monitored using a standardized protocol during awake glioma surgery in multiple neurosurgical centers.DISCUSSION:Despite limitations inherent to multicenter and observational studies, this study represents a necessary step toward developing a validated uniform way of collecting intraoperative findings on mapping of executive functions. The generation of high-quality Data sets is highly needed to extend the scientific basis for monitoring of white matter pathways involved in executive functions.</p

    Single-arm, open-label, multicentre first in human study to evaluate the safety and performance of dural sealant patch in reducing CSF leakage following elective cranial surgery: The ENCASE trial

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    Objective The dural sealant patch (DSP) is designed for watertight dural closure after cranial surgery. The goal of this study is to assess, for the first time, safety and performance of the DSP as a means of reducing cerebrospinal fluid (CSF) leakage in patients undergoing elective cranial intradural surgery with a dural closure procedure. Design First in human, open-label, single-arm, multicentre study with 360-day (12 months) follow-up. Setting Three large tertiary reference neurosurgical centres, two in the Netherlands and one in Switzerland. Participants Forty patients undergoing elective cranial neurosurgical procedures, stratified into 34 supratentorial and six infratentorial trepanations. Intervention Each patient received one DSP after cranial surgery and closure of the dura mater with sutures. Outcome measures Primary composite endpoint was occurrence of one of the following events: postoperative percutaneous CSF leakage, intraoperative leakage at 20 cm H 2 O positive end-expiratory pressure or postoperative wound infection. Overall success was defined as achieving the primary endpoint in no more than two patients. Secondary endpoints were device-related serious adverse events or adverse events (AEs), pseudomeningocele and thickness of dura+DSP. Additional endpoints were reoperation in 30 days and user satisfaction. Results No patients met the primary endpoint. No device-related (serious) AEs were observed. There were two incidences of self-limiting pseudomeningocele as confirmed on MRI. Thickness of dura and DSP were (mean±SD) 3.5 mm±2.0 at day 7 and 2.1 mm±1.2 at day 90. No patients were reoperated within 30 days. Users reported a satisfactory design and intuitive application. Conclusions DSP, later officially named Liqoseal, is a safe and potentially efficacious device for reducing CSF leakage after intracranial surgery, with favourable clinical handling characteristics. A randomised controlled trial is needed to assess Liqoseal efficacy against the best current practice for reducing postoperative CSF leakage. Trial registration number NCT03566602

    Hepatic saturated fatty acid fraction is associated with de novo lipogenesis and hepatic insulin resistance

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    Hepatic steatosis is associated with poor cardiometabolic health, with de novo lipogenesis (DNL) contributing to hepatic steatosis and subsequent insulin resistance. Hepatic saturated fatty acids (SFA) may be a marker of DNL and are suggested to be most detrimental in contributing to insulin resistance. Here, we show in a cross-sectional study design (ClinicalTrials.gov ID: NCT03211299) that we are able to distinguish the fractions of hepatic SFA, mono- and polyunsaturated fatty acids in healthy and metabolically compromised volunteers using proton magnetic resonance spectroscopy (H-1-MRS). DNL is positively associated with SFA fraction and is elevated in patients with non-alcoholic fatty liver and type 2 diabetes. Intriguingly, SFA fraction shows a strong, negative correlation with hepatic insulin sensitivity. Our results show that the hepatic lipid composition, as determined by our H-1-MRS methodology, is a measure of DNL and suggest that specifically the SFA fraction may hamper hepatic insulin sensitivity. Hepatic steatosis is associated with poor cardiometabolic health, with de novo lipogenesis (DNL) contributing to hepatic steatosis and subsequent insulin resistance. Here, the authors use H-1-MRS methodology to show hepatic SFA fraction is a measure of DNL and specifically may hamper hepatic insulin sensitivity.Peer reviewe

    Novel Insights Into Gyrate Atrophy of the Choroid and Retina (GACR):A Cohort Study

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    Gyrate atrophy of the choroid and retina (GACR, OMIM #258870) is a rare inherited metabolic disorder characterized by progressive chorioretinal degeneration and hyperornithinemia. Current therapeutic modalities potentially slow disease progression but are not successful in preventing blindness. To allow for trial development, increased knowledge of the clinical phenotype and current therapeutic outcomes is required. In this study, we analyzed 27 patients with GACR. The median age at inclusion was 24 years (range 8–58), with a median age at diagnosis of 14 years (range 0–42). Symptoms began at a mean age of 9 years (range 0–21). Mixed-models analysis showed a significant association between dietary natural protein intake and plasma ornithine levels. Ornithine increased significantly with age, independent of dietary natural protein intake. We found no statistically significant association between ornithine levels and best-corrected visual acuity over time. Patients who started a natural protein-restricted diet below 10 years of age had better VF outcomes compared to patients that started at a later age. MR spectroscopy was used to asses cerebral creatine deficiency, which was present in 15/20 patients, of whom 10 were supplemented with creatine at the time. Finally, using the Michigan Retinal Degeneration Questionnaire, we provided a first insight into the vision-related disability reported by patients with GACR and showed that higher foveal sensitivity was associated with less perceived disability. To conclude, this study provides insights into the phenotype, genotype, biochemistry, and treatment effects of GACR, which can be used for care pathways and clinical trial design.</p

    Long-Term Outcomes in Patients With Spontaneous Cerebellar Hemorrhage: An International Cohort Study

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    International audienceBACKGROUND:Spontaneous intracerebral hemorrhage (ICH) in the cerebellum has a poor short-term prognosis, whereas data on the long-term case fatality and recurrent vascular events are sparse. Herewith, we aimed to assess the long-term case fatality and recurrence rate of vascular events after a first cerebellar ICH.METHODS:In this international cohort study, we included patients from 10 hospitals (the United States and Europe from 1997 to 2017) aged ≥18 years with a first spontaneous cerebellar ICH who were discharged alive. Data on long-term case fatality and recurrence of vascular events (recurrent ICH [supratentoria or infratentorial], ischemic stroke, myocardial infarction, or major vascular surgery) were collected for survival analysis and absolute event rate calculation.RESULTS:We included 405 patients with cerebellar ICH (mean age [SD], 72 [13] years, 49% female). The median survival time was 67 months (interquartile range, 23–100 months), with a cumulative survival rate of 34% at 10-year follow-up (median follow-up time per center ranged: 15–80 months). In the 347 patients with data on vascular events 92 events occurred in 78 patients, after initial cerebellar ICH: 31 (8.9%) patients had a recurrent ICH (absolute event rate, 1.8 per 100 patient-years [95% CI, 1.2–2.6]), 39 (11%) had an ischemic stroke (absolute event rate, 2.3 [95% CI, 1.6–3.2]), 13 (3.7%) had a myocardial infarction (absolute event rate, 0.8 [95% CI, 0.4–1.3]), and 5 (1.4%) underwent major vascular surgery (absolute event rate, 0.3 [95% CI, 0.1–0.7]). The median time to a first vascular event during follow-up was 27 months (interquartile range, 8.7–50 months), with a cumulative hazard of 47% at 10 years.CONCLUSIONS:The long-term prognosis of patients who survive a first spontaneous cerebellar ICH is poor and comparable to that of patients who survive a first supratentorial ICH. Further identification of patients at high risk of vascular events following the initial cerebellar ICH is needed. Including patients with cerebellar ICH in randomized controlled trials on secondary prevention of patients with ICH is warranted

    The predictive validity of a Brain Care Score for late-life depression and a composite outcome of dementia, stroke, and late-life depression: data from the UK Biobank cohort

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    Introduction: The 21-point Brain Care Score (BCS) is a novel tool designed to motivate individuals and care providers to take action to reduce the risk of stroke and dementia by encouraging lifestyle changes. Given that late-life depression is increasingly recognized to share risk factors with stroke and dementia, and is an important clinical endpoint for brain health, we tested the hypothesis that a higher BCS is associated with a reduced incidence of future depression. Additionally, we examined its association with a brain health composite outcome comprising stroke, dementia, and late-life depression. Methods: The BCS was derived from the United Kingdom Biobank baseline evaluation in participants with complete data on BCS items. Associations of BCS with the risk of subsequent incident late-life depression and the composite brain health outcome were estimated using multivariable Cox proportional hazard models. These models were adjusted for age at baseline and sex assigned at birth. Results: A total of 363,323 participants were included in this analysis, with a median BCS at baseline of 12 (IQR: 11-14). There were 6,628 incident cases of late-life depression during a median follow-up period of 13 years. Each five-point increase in baseline BCS was associated with a 33% lower risk of incident late-life depression (95% CI: 29%-36%) and a 27% lower risk of the incident composite outcome (95% CI: 24%-30%). Discussion: These data further demonstrate the shared risk factors across depression, dementia, and stroke. The findings suggest that a higher BCS, indicative of healthier lifestyle choices, is significantly associated with a lower incidence of late-life depression and a composite brain health outcome. Additional validation of the BCS is warranted to assess the weighting of its components, its motivational aspects, and its acceptability and adaptability in routine clinical care worldwide
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