Volume Loss Research Articles

Association of Changes in Cerebral and Hypothalamic Structure With Sleep Dysfunction in Patients With Genetic Frontotemporal Dementia.

Sleep dysfunction is common in patients with neurodegenerative disorders; however, its neural underpinnings remain poorly characterized in genetic frontotemporal dementia (FTD). Hypothalamic nuclei important for sleep regulation may be related to this dysfunction. Thus, we examined changes in hypothalamic structure across the lifespan in patients with genetic FTD and whether these changes related to sleep dysfunction. Data from the observational multisite Genetic Frontotemporal Dementia Initiative (GENFI) study were used. GENFI participants were adult members of a family with known pathogenic variants in the microtubule-associated protein tau (MAPT) or progranulin (GRN) genes or an expansion in the chromosome 9 open reading frame 72 (C9orf72) gene. Family members without a pathogenic variant served as controls. GENFI participants were followed annually, with up to 7 visits, and underwent clinical characterization, neuropsychological testing, biological sampling, and brain MRI. For our analyses, participants were included if they had at least 1 T1-weighted structural MRI scan available. Linear mixed-effect models were used to examine changes in sleep dysfunction, measured using the Cambridge Behavioural Inventory-Revised sleep subscale, volumetric changes in hypothalamic regions, and the associations between cortical and hypothalamic atrophy and sleep dysfunction. Participants included 491 adults with pathogenic genetic variants of FTD (27.9% symptomatic; median age: 49.4 years, 56.4%F) and 321 controls (median age: 44.2 years, 57.3%F). Pathogenic variant carriers showed greater sleep dysfunction across the adult lifespan (β = [0.25-0.34], q < 0.005) with MAPT carriers alone showing presymptomatic sleep changes (β = 0.34, q = 0.005). Cortical thinning in frontal and parietal regions was associated with greater sleep disturbances in C9orf72 and GRN carriers (q < 0.05). MAPT carriers showed consistently significant volume loss over time across all sleep-relevant hypothalamic subunits (β = [-0.56 to -0.39], q < 0.005), and reduced volumes in these subunits were related to increased sleep dysfunction (β = [-0.20 to -0.16], q < 0.05). These findings suggest that sleep dysfunction in patients with genetic FTD may be attributable to atrophy in sleep-relevant hypothalamic subunits, with the most severe and consistent deficits observed in MAPT carriers. While biologically plausible, our statistical approach cannot confirm a causal link between atrophy and sleep disturbances.

Quantifying preserved renal volume and function in patients undergoing standard partial nephrectomy vs. tumor enucleation for localized renal tumors

IntroductionRenal parenchymal volume loss from standard partial nephrectomy (SPN) is a significant prognosticator for postoperative renal function. Tumor enucleation (TE) minimizes parenchymal loss compared to SPN. Little is known regarding discrete changes in renal function associated with volume loss. We sought to quantify the differences between SPN and TE in preserving parenchymal volume and estimated glomerular filtration rate (eGFR). MethodsWe identified 420 patients who underwent robotic partial nephrectomy (SPN or TE) at our tertiary care center from 2009 to 2022. Parenchymal volumes were calculated using TeraRecon 3D reconstruction software from axial imaging performed preoperatively and within 6 months postoperatively. Renal volume preserved and renal function were evaluated with multivariable linear and logistic regression models. ResultsAt 1 year, eGFR was 7% lower in patients undergoing SPN compared to TE (P < 0.01). Across both SPN and TE, only volume of preserved parenchyma was predictive of eGFR and chronic kidney disease (CKD) progression (both P < 0.01). TE preserved more healthy parenchymal volume compared to SPN (median percentage 97.6% vs 89.2%; P < 0.001). Each 1% of volumetric loss corresponded to a 0.35% decrease in eGFR at 1 year postoperatively (P < 0.01). ConclusionsVolume of preserved renal parenchyma was the strongest factor associated with preserved eGFR and reduced odds of CKD progression. TE preserved more parenchyma than SPN, which translated to higher eGFR preservation at 1 year postoperatively.

Case reports on hand prejuvenation: clinical outcomes in middle-aged women with hyaluronic acid filler plus lidocaine.

Hand rejuvenation with hyaluronic acid filler injections is gaining more attention for its ability to correct volume loss and improve skin quality. The hand dorsum is prone to loss of dermal elasticity and subcutaneous atrophy as individuals age, and administering hyaluronic acid fillers has become an option to restore the smoothness and youthful contour of the hand. The aim of this study is to demonstrate that injections with Definisse Touch Filler Plus Lidocaine are effective and safe for hand rejuvenation. Ten subjects underwent filler placement of 0.5 to 1.0 mL in the dorsal superficial lamina, which is devoid of sensory nerves and major skin vessels, using a blunt cannula via the fanning technique. Measurements were done before, immediately after, and 1 month after the treatment using validated aesthetic scales. There was a significant correction of volume loss immediately after the first treatment and an improvement in skin texture and topography 1 month after the procedure. No lasting or severe adverse effects were observed. To show significant and conclusive results, it is recommended to conduct further prospective, comparative, blinded studies in more subjects followed for longer periods (ie, 12 months or more). Objective analysis of volumetric changes using automated three-dimensional surface techniques is likewise beneficial. Injecting a low G-prime hyaluronic acid along the dorsal superficial lamina via cannula provides an effective and tolerable option for improving the appearance of aged hands.

Effect of theoretical volume fraction (TVF) of reinforcements on Al5083/SiC and Al5083/ZrB2 surface composites produced by friction stir processing

This study focuses on the effects of theoretical volume fraction (TVF) on the microstructure and mechanical properties of silicon carbide (SiC) and zirconium diboride (ZrB2) ceramic reinforced Al5083 surface composites (SC). Al5083-H111 was used as the base material (BM), SiC and ZrB2 were used as reinforcement materials, and TVFs were determined as 5, 10, 15, and 20% for SCs produced by the friction stirring process (FSP). Macrostructure, microstructure, X-ray diffraction (XRD) analysis and mechanical properties such as microhardness, tensile strength (UTS), and wear behaviour were characterised. When the TVF and AVF values of SiC and ZrB2 particles were compared, it was found that the AVFs were lower than the TVFs. Significant decreases in the changes in the SZ areas of SiC and ZrB2 particle SCs were detected depending on the reinforcement size. In the time-dependent axial load graphs of SiC and ZrB2 reinforced samples, load values ranging from 7800 to 8200 N were obtained and it was determined that these values were sufficient for friction heat, hydrostatic pressure, and plasticization in FSP. As a result of mechanical characterisation processes, the microhardness values and wear rates of ZrB2 reinforced SCs in the stir zone (SZ) were higher than SiC reinforced SCs. When the reinforcement particles were compared, it was observed that ZrB2 reinforced SCs exhibited higher microhardness and wear resistance than SiC reinforced SCs. As a result of all tests and investigations, it was determined that the ideal TVFs were 15% for SiC reinforced SCs and 5% for ZrB2 reinforced SCs. The microhardness value of ZrB2 reinforced SC with 20% TVF was 119.6 HV, while the UTS and volume loss values of ZrB2 reinforced SC with 5% TVF were found to be the highest values with 305.86 MPa and 1.83 mm3, respectively. Compared to BM, these values showed significant improvements in mechanical test results, especially in wear behavior. The results obtained showed an improvement of 55% in microhardness, 3.3% in UTS values, and 309% in wear behavior.

Effects of Fluoride-containing Biomimetic Agents on Remineralization and Color Change of Enamel White Spot Lesions: An In Vitro Study.

The aim of this study was to evaluate the effects of fluoride-containing remineralization agents on enamel white spot lesions. Twenty bovine incisors were cut mesio-distally and occluso-gingivally, creating 80 specimens, and divided into four groups (n=20/group): 1) control (no treatment); 2) fluoride varnish (Voco Profluoroid 5% NaF Varnish, VOCO Dental, Cuxhaven, Germany); 3) CPP-ACFP (MI Paste Plus with Recaldent, GC Corporation, Tokyo, Japan),; 4) self-assembling peptide (P11-4F, CURODONT Repair Fluoride Plus, Credentis AG, Windisch, Switzerland). After a three-week demineralization-remineralization cycle, white spot lesions were observed on the specimens. Before applying the remineralization agents, baseline demineralization values were determined using DIAGNOdent 2095, QLF-D Biluminator, SEM-EDS (KaVo Dental, Charlotte, NC, USA), and color values were measured by Vita EasyShade (Vita Zahnfabrik, Bad Säckingen, Germany). Remineralization agents were applied once, following the manufacturers' instructions. The remineralization capacities of these agents and their effects on color change were evaluated at four time points: baseline (T0), demineralization (T1), and remineralization on the seventh (T2) and 30th (T3) days. After 30 days, CPP-ACFP and P11-4F showed significantly greater Ca (% by weight), F (% by weight), and Ca/P ratio than the fluoride varnish group (p<0.05). SEM images revealed that in the groups where the remineralization agent was applied, the pores and tubules were blocked, and the surfaces were covered, whereas these findings were not observed in the control group. Based on QLF-D Biluminator data, P11-4F application provided more successful fluorescence changes compared to CPP-ACFP and fluoride applications and was statistically more effective in reducing lesion volume and maximum fluorescence loss (p<0.05). Significant differences were observed among the four groups at the seventh (T2) and 30th days (T3) in the laser fluorescence evaluation with DIAGNOdent (p<0.05). On the seventh day, the fluoride group exhibited greater effectiveness than the control group, while on the 30th day, the CPPACFP group demonstrated superior improvement over the control group (p<0.05). According to color change results, applying a remineralization agent was found to be a statistically successful method in restoring the tooth's original color (p<0.05). However, there were no significant differences among the treatment groups (p>0.05). CPP-ACFP and P11-4F demonstrated positive effects on remineralization at the seventh and 30th days. Applying a remineralization agent is a viable option for blocking pores and tubules on demineralized enamel. The color change related to the use of the remineralization agent showed a positive effect over time.

A Case of Supraorbital Hypoesthesia Following Double Orbital Sphere Volume Implant.

The patient is a 63-year-old female with past ocular history of end-stage glaucoma in her OD. To maintain symmetry and achieve cosmesis with her right orbit, she chose to proceed with enucleation of the eye with a donor sclera-wrapped 20-mm silicone sphere implant. After 1 year, she developed right enophthalmos due to volume loss. The patient opted for an additional sphere to be placed posterior to the original sphere. A 14-mm silicone sphere was placed through a lateral orbitotomy into the intraconal space. On postoperative day 1, the patient developed numbness along the V1 trigeminal nerve in the supraorbital region, extending past her hairline. The implant was removed 1 week later, and the authors are currently waiting for nerve recovery. This is a rare and challenging postoperative complication, possibly explained by nerve compression, demyelination, or nerve ischemia.

Cognitive deficits after COVID-19 associated with brain injury biomarkers and volume loss.

Cognitive deficits after COVID-19 associated with brain injury biomarkers and volume loss.

Microbial growth within porous gravity currents

The effect of microbial activity on buoyancy-driven flow within a porous layer is analysed. The input fluid provides an energy source for the growth of biofilms on the porous rock. At each location within the porous layer, the porosity and permeability begin to decrease once the input fluid has invaded. This leads to an evolving rock heterogeneity that depends on the passing time of the input fluid. Hence, the evolution of the flow is partly controlled by its own history. We present an axisymmetric gravity current model, accounting for this effect. In general, a reduction in permeability leads to the flow having a lesser extent in the radial direction and greater thickness (extent in the cross-flow direction), whilst a reduction in porosity has negligible effect on the thickness but leads to a much greater radial extent. The flow is fastest near the free surface where the permeability is greatest. In the case where the porosity and permeability reduce as power-law functions of fluid residence time, the evolution of the flow and the rock properties are self-similar. Consumption of the input fluid by the microbes is also incorporated in the model and it generally leads to flows with lesser radial extent but little change in the thickness. The three impacts of microbial growth (volume loss owing to consumption and the reduction in permeability and porosity) each influence the flow in substantially different ways and the interplay is analysed. A motivation of the study, the underground storage of hydrogen, is briefly discussed.

Temple Volumization: A Review of Anatomy and Optimal Injection Techniques.

Cosmetically unappealing temporal volume loss can develop as a result of facial aging. To present an evidenced-based approach towards safe and effective temple filling. We review the underlying anatomy of the temple and optimal anatomy-driven injection techniques associated with temple volumization. Multiple safe injection planes exist to achieve temporal volumization. A thorough understanding of optimal injection techniques based on the underlying anatomy mitigates the incidence and severity of adverse events, enhancing treatment success.

A longitudinal study of hippocampal subfield volumes and hippocampal glutamate levels in antipsychotic-naïve first episode psychosis patients.

Previous studies have implicated hippocampal abnormalities in the neuropathology of psychosis spectrum disorders. Reduced hippocampal volume has been reported across all illness stages, and this atrophy has been hypothesized to be the result of glutamatergic excess. To test this hypothesis, we measured hippocampal subfield volumes and hippocampal glutamate levels in antipsychotic naïve first episode psychosis patients (FEP) and the progression of volume decline and changes in glutamate levels over a 16-week antipsychotic drug (APD) trial. We aimed to determine if subfield volumes at baseline were associated with glutamate levels, and if baseline glutamate levels were predictive of change in subfield volumes over time. We enrolled ninety-three medication-naïve FEP participants and 80 matched healthy controls (HC). T1 and T2 weighted images and magnetic resonance spectroscopy (MRS) data from a voxel prescribed in the left hippocampus were collected from participants at baseline and after 6 and 16 weeks of APD treatment. Hippocampal subfield volumes were assessed using FreeSurfer 7.1.1., while glutamate levels were quantified using jMRUI version 6.0. Data were analyzed using linear mixed models. We found regional subfield volume deficits in the CA1, and presubiculum in FEP at baseline, that further expanded to include the molecular and granule cell layer of the dentate gyrus (GC/ML/DG) and CA4 by week 16. Baseline hippocampal glutamate levels in FEP were not significantly different than those of HC, and there was no effect of treatment on glutamate. Glutamate levels were not related to initial subfield volumes or volume changes over 16 weeks. We report a progressive loss of hippocampal subfield volumes over a period of 16 weeks after initiation of treatment, suggestive of early progression in neuropathology. Our results do not suggest a role for glutamate as a driving factor. This study underscores the need to further research the mechanism(s) underlying this phenomenon as it has implications for early intervention to preserve cognitive decline in FEP participants.

Empirical prediction of horizontal movements induced by tunnelling in fine-grained soils

Available evidence indicates that the focal depth of displacement vectors along the ground surface decreases with the transverse distance from the tunnel centre-line. Based on field and centrifuge observations, this paper presents a new empirical method in which the focal depth is a function of the transverse offset and, possibly, the tunnel volume loss. The comparison with experimental data from centrifuge experiments and case histories confirms the reliability of the proposed method, in terms of both surface horizontal displacements and strains. In particular, the predicted horizontal displacement profiles, both in terms of maximum value and extension, are in better agreement with the available experimental evidence than those obtained using the empirical and analytical methods currently adopted in design. Finally, an operational way to obtain the complete horizontal displacement field at the surface, near-surface, and at depths down to the tunnel crown is suggested and the importance of carrying out field monitoring for surface and subsurface horizontal displacements is highlighted.

Neuroimaging Spectrum of Erdheim-Chester Disease: An Image-based Review.

Erdheim-Chester Disease (ECD) is a rare, multisystem histiocytic disorder characterized by its variable clinical presentations. Central Nervous System (CNS) involvement is observed in approximately half of ECD patients (up to 76% in some series), and often carries a poorer prognosis. While CNS involvement may remain asymptomatic, others may experience a range of neurological symptoms, including cognitive decline, neuropsychiatric disturbances, motor deficits, cranial or peripheral neuropathies, and endocrine abnormalities.Neuroimaging findings in CNS-ECD are diverse, including neurodegeneration manifesting as cerebral or cerebellar volume loss, solitary or multifocal variably enhancing intraparenchymal lesions along the neuroaxis, meningeal infiltration, involvement of the Hypothalamo-pituitary axis, perivascular sheathing or basal ganglia lesions. Other well documented sites of involvement include the craniofacial region, orbits and spine. Awareness of these findings is relevant, not only because of the non-specific nature of these findings, but also given the high proportion of CNS involvement in ECD as well as the higher mortality associated with CNS involvement.This review provides an in-depth overview of the various manifestations of CNS involvement in ECD and their imaging features, along with a brief overview of the differential considerations which include other histiocytic and non-histiocytic processes.ABBREVIATIONS: ECD＝Erdheim-Chester Disease; RDD＝Rosai-Dorfman Disease; LCH= Langerhans cell histiocytosis.

Microstructure and tribological properties of atmospheric plasma-sprayed TiO2 coatings reinforced by boron nitride nanosheets

ABSTRACT In this study, boron nitride nanosheets (BNNSs)/TiO2 composite coatings were fabricated using atmospheric plasma spraying. The phase composition and microstructure of composite coatings were characterized through X-ray diffraction (XRD) and scanning electron microscopy (SEM). Additionally, tribological tests were conducted using a ball-on-disc tribometer under dry sliding conditions. XRD analysis reveals the transformation of partial anatase TiO2 to rutile TiO2. SEM images demonstrate that the incorporation of BNNSs has no discernible impact on the coating’s morphology. The TiO2-BNNSs coating exhibited a reduction in both volume loss and wear rate by approximately 71.5% and 55.9%, respectively, in comparison to the TiO2 coating. The potential strengthening mechanisms of the composite coating are further discussed.

Transformation from D022 to L12 in Al3Ti by Fe Addition for Enhanced Wear Resistance

The addition of third elements may help transform brittle D022-structured lightweight Al3Ti to a relatively ductile L12-structured (Al, M)3Ti (where M represents the third elements), thus increasing the ductility at the expense of hardness. Such a transformation could benefit the wear resistance of the alloy due to improved toughness if a proper balance between the hardness and ductility is achieved. In this work, a D022-predominant Al3Ti alloy (S-Al3Ti) and an L12-predominant (Al, Fe)3Ti alloy (S-Al67Ti25Fe8) were fabricated by arc melting. Change in wear resistance, corresponding to a D022-to-L12 transformation, caused by the addition of Fe as a representative third element, was investigated and compared with the wear resistance of a commercial Al-matrix composite reinforced by 30 wt.% SiC particles (S-Al/SiCp) as a reference material. It was observed that wear of the S-Al3Ti resulted from abrasion involving synergistic oxidation, leading to a larger volume loss. In contrast, the softer S-Al67Ti25Fe8 showed enhanced wear resistance, benefiting from improved toughness with reasonable hardness. During the wear testing, both the alloys exhibited better performance than S-Al/SiCp, a well-known lightweight composite. This study highlights that D022-to-L12 transformation enhances wear resistance due to increased toughness which can be adjusted using the addition of a third element.

Theoretical Analysis of Shaft Wall Damage and Failure Under Impacting of Ore-Rock Falling in Vertical Ore Pass

The impact of ore-rock blocks on the shaft wall of a vertical ore pass is a crucial cause of shaft wall damage and failure. Based on the structure and parameters of the ore pass in a case mine, the first collision’s position of the ore-rock block with respect to the ore pass wall and the angle between the impacting direction of the ore-rock block and the horizontal plane before and after the collision are investigated via a kinematic analysis. The normal and tangential analysis models of ore rock impacting the shaft wall are established and analyzed based on contact mechanics. The results show that: (1) based on the kinematic analysis of ore rock moving in the ore pass and on the colliding condition of the ore-rock block the first time that it collides with the ore pass wall, the coordinates and angles of the collision are proposed; (2) the impacting process of ore rock is categorized into elastic compression, elastic–plastic compression, and rebound of the shaft wall material. The relationship between the normal impact force and the penetrating depth is determined, and the slipping distance of the ore-rock block along the shaft wall and the lost volume of the shaft material are established. (3) The wall material’s normal, tangential, and total restitution coefficient is acquired. (4) The total lost volume during the collision is obtained through the analysis and solution of the model. (5) Based on the characteristics and parameters of the ore pass in the case mine, the influence of the impact velocity and angle of the ore-rock block on the restitution coefficient, maximum normal intrusion depth, maximum tangential displacement, and volume loss of the shaft wall are analyzed by using relevant formulas.

Brain morphometry in hepatic Wilson disease patients.

Wilson disease (WD) primarily presents with hepatic and neurological symptoms. While hepatic symptoms typically precede the neurological manifestations, copper accumulates in the brain already in this patient group and leads to subclinical brain MRI abnormalities including T2 hyperintensities and atrophy. This study aimed to assess brain morphological changes in mild hepatic WD. WD patients without a history of neurologic symptoms and decompensated cirrhosis and control participants underwent brain MRI at 3T scanner including high-resolution T1-weighted images. A volumetric evaluation was conducted on the following brain regions: nucleus accumbens, caudate, pallidum, putamen, thalamus, amygdala, hippocampus, midbrain, pons, cerebellar gray matter, white matter (WM), and superior peduncle, using Freesurfer v7 software. Whole-brain analyses using voxel- and surface-based morphometry were performed using SPM12. Statistical comparisons utilized a general linear model adjusted for total intracranial volume, age, and sex. Twenty-six WD patients with mild hepatic form (30 ± 9 years [mean age ± SD]); 11 women; mean treatment duration 13 ± 12 (range 0-42) years and 28 healthy controls (33 ± 9 years; 15 women) were evaluated. Volumetric analysis revealed a significantly smaller pons volume and a trend for smaller midbrain and cerebellar WM in WD patients compared to controls. Whole-brain analysis revealed regions of reduced volume in the pons, cerebellar, and lobar WM in the WD group. No significant differences in gray matter density or cortical thickness were found. Myelin or WM in general seems vulnerable to low-level copper toxicity, with WM volume loss showing promise as a marker for assessing brain involvement in early WD stages.

Long-Term Cerebellar Consequences of Post-traumatic Brain Injury Assessed by MRI With Diffusion Tensor Imaging

BACKGROUND AND OBJECTIVES: Post-traumatic brain injury (TBI) lesions, which combine brain atrophy and white matter injuries, can lead to progressive post-traumatic encephalopathy. However, the specific involvement of the cerebellum, which participates in cognitive, executive, and sensory functions, has been little studied. The aim of this work was to explore the long-term cerebellar consequences of severe TBI. METHODS: In this retrospective study, patients included were hospitalized for a severe TBI and reassessed after discharge with a clinical examination and a MRI with diffusion tensor imaging. Patients were compared with a population of healthy volunteers. For a subgroup of this cohort, we analyzed the evolution of late post-TBI lesions on MRI up to 10 years after TBI. RESULTS: Ninety-seven patients reassessed 5 [3; 6] years after the TBI were included. Volume loss was revealed in the whole cerebellum (P = .01) and especially in the anterior lobe (P &lt; .005) with a decrease in grey matter volume (P = 6.10−3). The mean diffusivity was increased in 4 cerebellar areas which are the right lower, right upper, left lower, and left upper cerebellar peduncles while the fractional anisotropy was decreased in all studied areas (P &lt; 10−3). The longitudinal analysis (n = 17 patients) showed no progression of MRI lesions beyond the acute phase. CONCLUSION: This work shows that even if direct cerebellar damage is rare, long-term post-TBI cerebellar lesions can be observed. Therefore, clinical correlates of cerebellar lesions should be considered more systematically.

Paracetamol overdose associated with cortical blindness-complicated acute leukoencephalopathy: a case report

BackgroundParacetamol is one of the most used antipyretics and analgesics among pediatrics, and its overdose is highly encountered among pediatrics especially in the pre-school age. While it is well-known that paracetamol overdose may lead to toxicities including severe hepatic toxicity, some recent reports have highlighted its “in situ” toxicity on brain tissue at high doses, even in the absence of hepatotoxicity. This can result in acute leukoencephalopathy (AL), coma, or even death. This report describes a case of a child who developed cortical blindness-complicated AL, following a paracetamol overdose.Case presentationAn 18-month-old previously healthy girl accidentally ingested 300 mg/kg of paracetamol suspension. After ingestion, the child was in an initial bad condition that has gradually improved. Several days after ingestion, the patient lost her vision, and she remained blind since then despite a newer appreciation to light. The initial brain magnetic resonance imaging (MRI) suggested AL demonstrated as a faint high T2/fluid-attenuated inversion recovery (FLAIR) signal intensity in the cortical and subcortical regions of both parieto-occipital lobes with sulcal effacement and restricted diffusion. After around 3 months, the subsequent brain MRI showed involutional changes that were manifested as a brain volume loss in the same areas with evidence of gyri-form laminar necrosis in both parieto-occipital regions without restricted diffusion. Other brain MRI findings include right cerebral convexity hyperacute subdural hematoma with prominent subarachnoid spaces.ConclusionsThe child developed cortical blindness-complicated AL following a paracetamol overdose. It is well- known that AL may result from several toxins by their direct and/or indirect effect on the cerebral white matter. However, there is still no enough data in the literature clearly explaining the relation of paracetamol overdose to AL. The generally proposed effect of paracetamol on the brain is mainly justified by the excessive oxidative stress. Further studies at the cellular and genetic levels are still needed to investigate the exact association between paracetamol overdose and AL, as well as the underlying mechanisms involved.

Dynamic LIA advances hastened the demise of small valley glaciers in central Svalbard

Most small land-terminating glaciers in Svalbard have experienced large recession since the Little Ice Age (LIA) and today are thin, cold, and largely inactive. This likely contrasts to their LIA conditions, but the observational record from that time is sparse. We investigate the evolution of five small glaciers in central Nordenskiöld Land, Svalbard, from the LIA to 2019. Photogrammetric reconstructions and ground penetrating radar are used to reconstruct their geometric changes since 1936, and historical observation, photographs, and geomorphological mapping extend this history to before the 1900s. Our results show that from 1936 to 2019, the study glaciers on average lost 49.6% of their area and 77.4% ± 7.7% of their volume, with the greatest volume loss at Scott Turnerbreen of 91% ± 5%. Four out of these five glaciers strongly indicate a history of surge-like advances near the end of the LIA within one or two decades, and the rate of subsequent mass loss seems connected to their previous dynamics. This apparent switch to high activity during a period of rapid climatic change, could have implications for our understanding of past and future glacier evolution; climate change and highly dynamic glacier responses may be more connected than previously thought.

Evaluation of the physicochemical properties of intracanal medications used in traumatized teeth

Aim: The aim of the present study was to evaluate the solubility, flow and radiopacity of Calen (SS White Artigos Dentários Ltd, Rio de Janeiro, Brazil), Calen with zinc oxide (Calen/ZnO), calcium hydroxide + zinc oxide + 2% chlorhexidine (CH/ZnO/CHX), Calplus and Ultracal XS. Methods: 28 bovine incisor specimens were standardized, instrumented and filled with pastes with the aid of a centrix syringe. To assess solubility, the root canals of acrylic teeth (N = 10) were filled with the previously mentioned pastes and scanned by using micro–computed tomography before (initial) and after 7 days of immersion in ultrapure water. The solubility of each specimen was the difference between the initial and final volume. Flow properties were analysed according to the ISO 6876/2012 standard. Radiopacity was radiographically analysed by using Image J software. Data were submitted to analysis of variance and Tukey’s test (alpha 5%). Results: CH/ZnO/CHX and Calplus presented similar values regarding radiopacity. The group composed of Calen paste showed higher flow values. As for solubility, CH/ZnO/ CHX showed lower volume loss, but there was no statistical difference compared to other medications. Conclusion: The medication composed of calcium hydroxide, zinc oxide and 2% chlorhexidine is a suitable alternative for use in traumatized teeth.