78 research outputs found

    Evaluation of the Coulter Counter S-Plus VI

    Get PDF
    This article reports an evaluation of the Coulter Counter model S-Plus VI automatic analyser for haematology, and data are presented on linearity, carry-over, precision, accuracy and stability of the instrument, when compared with a model S-Plus IV/D

    Experimental results on the physical model of an USBR type II stilling basin

    Get PDF
    The present paper describes the experimental campaign carried on the physical model of the spillway of Lower Diamphwe Dam (Malawi), which is provided with a USBR type II stilling basin. Stilling basins are used in order to reduce the excessive kinetic energy of flowing water downstream of spillways. Specifically, a USBR type II basin is provided with blocks at the end of the chute and with a confining dentated sill; these appurtenances allow to dissipate excess energy with high efficiency. The study focuses on the hydraulic behavior of the stilling basin; tests were carried on for different values of incoming discharge and downstream water depth. Results show the dissipation efficiency of the stilling basin in terms of pressure fluctuation and the variability of the jump type with the hydraulic characteristics of the incoming and the downstream flow depths

    Multiple vertebral hemangiomas of the thoracic spine with atypical radiological features and aggressive behavior causing myelopathy: A case report

    Get PDF
    Abstract Background Vertebral Haemangiomas (VHs) are frequent and generally asymptomatic benign tumors, involving the spine, usually incidentally found on computed tomography and magnetic resonance. Despite being usually asymptomatic and quiescent lesions, VHs can occasionally manifest aggressive features, leading to clinical manifestations such as back pain and neurological deficits. Case report. We report a case of a 54-year-old man, presented with 5 months history of pain, associated with lower limbs paraesthesia and weakness, gait disturbance and episodes of accidental falls. Radiological evaluation by spine pre- and post-contrast MRI indicated multiple vertebral hypervascular lesions, compatible with haemangiomas, involving from T3 to T11 levels, showing several different features (typical and atypical); aggressive haemangioma radiological pattern may be valuable at T3 and T4 vertebras. A thoracic spine pre- and post-contrast computed tomography confirmed the radiological diagnosis of multiple aggressive haemangiomas. Discussion Aggressive VH consists in a very rare subset of vertebral haemangiomas characterized by a greater tendency in being symptomatic. They may show atypical radiological features, that make their diagnosis very complex. In the recent years, many strategies for treatment of symptomatic or aggressive VHs have been developed, but the optimal treatment strategy is still controversial. Conclusion Although aggressive VHs being extremely rare, recognizing radiological features of these lesions is mandatory to achieve a correct diagnosis and appropriate therapeutic targets

    State of the Art in Artificial Intelligence and Radiomics in Hepatocellular Carcinoma

    Get PDF
    The most common liver malignancy is hepatocellular carcinoma (HCC), which is also associated with high mortality. Often HCC develops in a chronic liver disease setting, and early diagnosis as well as accurate screening of high-risk patients is crucial for appropriate and effective management of these patients. While imaging characteristics of HCC are well-defined in the diagnostic phase, challenging cases still occur, and current prognostic and predictive models are limited in their accuracy. Radiomics and machine learning (ML) offer new tools to address these issues and may lead to scientific breakthroughs with the potential to impact clinical practice and improve patient outcomes. In this review, we will present an overview of these technologies in the setting of HCC imaging across different modalities and a range of applications. These include lesion segmentation, diagnosis, prognostic modeling and prediction of treatment response. Finally, limitations preventing clinical application of radiomics and ML at the present time are discussed, together with necessary future developments to bring the field forward and outside of a purely academic endeavor

    Progressive multifocal leukoencephalopathy presenting with bilateral myoclonus: a case report

    Get PDF
    Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system (CNS) caused by John Cunningham virus lytic infection of the oligodendrocytes, the myelin-producing cells in the CNS. Symptoms largely vary depending on location and size of the lesions, and the most frequent clinical presentation is characterized by motor deficits, altered consciousness, gait ataxia, and visual symptoms. Despite limb weakness or hemiparesis as the most frequent presenting symptom, involuntary movement is far less common, and very few cases are described in the literature with focal movement disorders without additional neurologic abnormalities. Here we described a case of PML in a patient treated for non-Hodgkin lymphoma with immunomodulatory chemotherapies who presented with bilateral myoclonus of the upper limbs. This report highlights the importance of considering PML in the differential diagnosis of focal movement disorders and discusses the potential causative mechanism of this atypical presentation

    Clinical correlates of R1 relaxometry and magnetic susceptibility changes in multiple sclerosis: a multi-parameter quantitative MRI study of brain iron and myelin

    Get PDF
    Objectives: The clinical impact of brain microstructural abnormalities in multiple sclerosis (MS) remains elusive. We aimed to characterize the topography of longitudinal relaxation rate (R1) and quantitative susceptibility (χ) changes, as indices of iron and myelin, together with brain atrophy, and to clarify their contribution to cognitive and motor disability in MS. Methods: In this cross-sectional study, voxel-based morphometry, and voxel-based quantification analyses of R1 and χ maps were conducted in gray matter (GM) and white matter (WM) of 117 MS patients and 53 healthy controls. Voxel-wise between-group differences were assessed with nonparametric permutation tests, while correlations between MRI metrics and clinical variables (global disability, cognitive and motor performance) were assessed both globally and voxel-wise within clusters emerging from the between-group comparisons. Results: MS patients showed widespread R1 decrease associated with more limited modifications of χ, with atrophy mainly involving deep GM, posterior and infratentorial regions (p < 0.02). While R1 and χ showed a parallel reduction in several WM tracts (p < 0.001), reduced GM R1 values (p < 0.001) were associated with decreased thalamic χ (p < 0.001) and small clusters of increased χ in the caudate nucleus and prefrontal cortex (p < 0.02). In addition to the atrophy, χ values in the cingulum and corona radiata correlated with global disability and motor performance, while focal demyelination correlated with cognitive performance (p < 0.04). Conclusions: We confirmed the presence of widespread R1 changes, involving both GM and WM, and atrophy in MS, with less extensive modifications of tissue χ. While atrophy and χ changes are related to global and motor disability, R1 changes are meaningful correlates of cognition. Key points: • Compared to healthy controls, multiple sclerosis patients showed R1 and χ changes suggestive of iron increase within the basal ganglia and reduced iron and myelin content within (subnuclei of) the thalamus. • Thalamic volume and χ changes significantly predicted clinical disability, as well as pulvinar R1 and χ changes, independently from atrophy. • Atrophy-independent R1 and χ changes, suggestive of thalamic iron and myelin depletion, may represent a sensitive marker of subclinical inflammation

    Reduced intracranial volume in Fabry Disease: Evidence of abnormal neurodevelopment?

    Get PDF
    Introduction: Lysosomal storage disorders (LSD) are often characterized by abnormal brain development, reflected by a reduction of intracranial volume (ICV). The aim of our study was to perform a volumetric analysis of intracranial tissues in Fabry Disease (FD), investigating possible reductions of ICV as a potential expression of abnormal brain development in this condition. Materials and Methods: Forty-two FD patients (15males,mean age 43.3±13.0 years) were enrolled along with 38 healthy controls (HC) of comparable age and sex. Volumetric MRI data were segmented using SPM12 to obtain intracranial tissue volumes, from which ICV values were derived. Results: Mean ICV of FD patients was 8.1% smaller compared to the control group (p<5·10−5). Unlike what typically happens in neurodegenerative disorders, no significant differences emerged when comparing between the two groups the fractional volumes of gray matter, white matter and CSF (i.e., normalized by ICV), consistent with a harmonious volumetric reduction of intracranial structures. Discussion: The present results suggest that in FD patients an abnormality of brain development is present, expanding the current knowledge about central nervous system involvement in FD, further emphasizing the importance of an early diagnosis

    Visual Snow Syndrome Improves With Modulation of Resting-State Functional MRI Connectivity After Mindfulness-Based Cognitive Therapy: An Open-Label Feasibility Study

    Get PDF
    BACKGROUND: Visual snow syndrome (VSS) is associated with functional connectivity (FC) dysregulation of visual networks (VNs). We hypothesized that mindfulness-based cognitive therapy, customized for visual symptoms (MBCT-vision), can treat VSS and modulate dysfunctional VNs. METHODS: An open-label feasibility study for an 8-week MBCT-vision treatment program was conducted. Primary (symptom severity; impact on daily life) and secondary (WHO-5; CORE-10) outcomes at Week 9 and Week 20 were compared with baseline. Secondary MRI outcomes in a subcohort compared resting-state functional and diffusion MRI between baseline and Week 20. RESULTS: Twenty-one participants (14 male participants, median 30 years, range 22-56 years) recruited from January 2020 to October 2021. Two (9.5%) dropped out. Self-rated symptom severity (0-10) improved: baseline (median [interquartile range (IQR)] 7 [6-8]) vs Week 9 (5.5 [3-7], P = 0.015) and Week 20 (4 [3-6], P < 0.001), respectively. Self-rated impact of symptoms on daily life (0-10) improved: baseline (6 [5-8]) vs Week 9 (4 [2-5], P = 0.003) and Week 20 (2 [1-3], P < 0.001), respectively. WHO-5 Wellbeing (0-100) improved: baseline (median [IQR] 52 [36-56]) vs Week 9 (median 64 [47-80], P = 0.001) and Week 20 (68 [48-76], P < 0.001), respectively. CORE-10 Distress (0-40) improved: baseline (15 [12-20]) vs Week 9 (12.5 [11-16.5], P = 0.003) and Week 20 (11 [10-14], P = 0.003), respectively. Within-subject fMRI analysis found reductions between baseline and Week 20, within VN-related FC in the i) left lateral occipital cortex (size = 82 mL, familywise error [FWE]-corrected P value = 0.006) and ii) left cerebellar lobules VIIb/VIII (size = 65 mL, FWE-corrected P value = 0.02), and increases within VN-related FC in the precuneus/posterior cingulate cortex (size = 69 mL, cluster-level FWE-corrected P value = 0.02). CONCLUSIONS: MBCT-vision was a feasible treatment for VSS, improved symptoms and modulated FC of VNs. This study also showed proof-of-concept for intensive mindfulness interventions in the treatment of neurological conditions

    Evaluation of Disability Progression in Multiple Sclerosis via Magnetic-Resonance-Based Deep Learning Techniques

    Get PDF
    Short-term disability progression was predicted from a baseline evaluation in patients with multiple sclerosis (MS) using their three-dimensional T1-weighted (3DT1) magnetic resonance images (MRI). One-hundred-and-eighty-one subjects diagnosed with MS underwent 3T-MRI and were followed up for two to six years at two sites, with disability progression defined according to the expanded-disability-status-scale (EDSS) increment at the follow-up. The patients' 3DT1 images were bias-corrected, brain-extracted, registered onto MNI space, and divided into slices along coronal, sagittal, and axial projections. Deep learning image classification models were applied on slices and devised as ResNet50 fine-tuned adaptations at first on a large independent dataset and secondly on the study sample. The final classifiers' performance was evaluated via the area under the curve (AUC) of the false versus true positive diagram. Each model was also tested against its null model, obtained by reshuffling patients' labels in the training set. Informative areas were found by intersecting slices corresponding to models fulfilling the disability progression prediction criteria. At follow-up, 34% of patients had disability progression. Five coronal and five sagittal slices had one classifier surviving the AUC evaluation and null test and predicted disability progression (AUC &gt; 0.72 and AUC &gt; 0.81, respectively). Likewise, fifteen combinations of classifiers and axial slices predicted disability progression in patients (AUC &gt; 0.69). Informative areas were the frontal areas, mainly within the grey matter. Briefly, 3DT1 images may give hints on disability progression in MS patients, exploiting the information hidden in the MRI of specific areas of the brain

    De novo rational design of a freestanding, supercharged polypeptide, proton-conducting membrane

    Get PDF
    Proton translocation enables important processes in nature and man-made technologies. However, controlling proton conduction and fabrication of devices exploiting biomaterials remains a challenge. Even more difficult is the design of protein-based bulk materials without any functional starting scaffold for further optimization. Here, we show the rational design of proton-conducting, protein materials exceeding reported proteinaceous systems. The carboxylic acid-rich structures were evolved step by step by exploring various sequences from intrinsically disordered coils over supercharged nanobarrels to hierarchically spider β sheet containing protein-supercharged polypeptide chimeras. The latter material is characterized by interconnected β sheet nanodomains decorated on their surface by carboxylic acid groups, forming self-supportive membranes and allowing for proton conduction in the hydrated state. The membranes showed an extraordinary proton conductivity of 18.5 ± 5 mS/cm at RH = 90%, one magnitude higher than other protein devices. This design paradigm offers great potential for bioprotonic device fabrication interfacing artificial and biological systems
    • …
    corecore