1,024 research outputs found
The response of high latitude ionosphere to the 2015 June 22 storm
This work investigates physical mechanisms triggering phase scintillations on L-band signals under strong stormy conditions. Thanks to selected ground-based Global Navigation Satellite Systems (GNSS) receivers, located both in Antarctica and in the Arctic, an interhemispheric comparison between high latitude ionospheric observations in response to the peculiar solar wind conditions occurred on June 22, 2015 is here shown. To trace back the observed phase scintillations to the physical mechanisms driving it, we combine measurements from GNSS receivers with in-situ and ground-based observations. Our study highlights the ionospheric scenario in which irregularities causing scintillation form and move, leveraging on a multi-observation approach. Such approach allows deducing that scintillations are caused by the presence of fast-moving electron density gradients originated by particle precipitation induced by solar wind variations. In addition, we show how the numerous and fast oscillations of the north-south component of the interplanetary magnetic field (Bz,IMF) result to be less effective in producing moderate/intense scintillation events than during period of long lasting negative values. Finally, we also demonstrate how the in-situ electron density data can be used to reconstruct the evolution of the ionospheric dynamics, both locally and globally
Investigation of the Physical Processes Involved in GNSS Amplitude Scintillations at High Latitude: A Case Study
The storm onset on 7 September 2017, triggered several variations in the ionospheric electron density, causing severe phase fluctuations at polar latitudes in both hemispheres. In addition, although quite rare at high latitudes, clear amplitude scintillations were recorded by two Global Navigation Satellite System receivers during the main phase of the storm. This work attempted to investigate the physical mechanisms triggering the observed amplitude scintillations, with the aim of identifying the conditions favoring such events. We investigated the ionospheric background and other conditions that prevailed when the irregularities formed and moved, following a multi-observations approach. Specifically, we combined information from scintillation parameters and recorded by multi-constellation (GPS, GLONASS and Galileo) receivers located at Concordia station (75.10°S, 123.35°E) and SANAE IV base (71.67°S, 2.84°W), with measurements acquired by the Special Sensor Ultraviolet Spectrographic Imager on board the Defense Meteorological Satellite Program satellites, the Super Dual Auroral Radar Network, the Swarm constellation and ground-based magnetometers. Besides confirming the high degree of complexity of the ionospheric dynamics, our multi-instrument observation identified the physical conditions that likely favor the occurrence of amplitude scintillations at high latitudes. Results suggest that the necessary conditions for the observation of this type of scintillation in high-latitude regions are high levels of ionization and a strong variability of plasma dynamics. Both of these conditions are typically featured during high solar activity
Tongue stretching: technique and clinical proposal.
Abstract
Objectives
The tongue is an organ with multiple functions, from sucking to phonation, from swallowing to postural control and equilibrium. An incorrect position or mechanics of the tongue can causes sucking problems in the newborn or atypical swallowing in the adult, with repercussions on the position of the head and neck, up to influencing upright posture and other problems. Tongue dysfunctions are quite frequent (10–15%) in the population. For the manual therapist, this frequency indicates one to two subjects every 30 patients. Exercises have been proposed to improve the tone and strength of the swallowing muscles but the results are not so clear in the literature. The aim of this study is to describe and provide a tongue muscle normalization technique that helps the manual therapist in the treatment of problems related to it.
Methods
The literature has been investigated through pubmed, Google scholar of the last 10 years, the keywords used and combined with the Boolean operators AND and OR, are: "tongue, tongue habits, tongue diseases, taste disorder, neck pain, posture, postural balance, atypical swallowing, muscle stretching exercise, tissue expansion, soft tissue therapy, osteopathic manipulative treatment".
Results and Conclusions
The technique is possible to be executed even in a sitting position, in the case the patient is unable to assume a supine position, the subject should provides immediate feedback that allows the therapist to understand if the technique has been correctly executed. The simplicity of execution and application of the technique makes it a possible and immediate therapeutic tool in the clinical setting
Vitamin K deficiency bleeding leading to a diagnosis of Crohn’s Disease
We report the case of a 45 year old man who came to Emergency Room of Polyclinic for sudden onset of localized ecchymosis and widespread hematomas. He was subjected to blood count and first level investigations to assess coagulation. Based on the results, second level investigations were performed. Endoscopy of the gastrointestinal tract with histological examination revealed a diagnosis of Crohn's disease. Vitamin K deficiency causes the formation of vitamin K-dependent clotting factors that cannot perform their pro-coagulant action. Consequently, patients present with hemorrhagic manifestations. Clinical and laboratory features observed in this patient show that the deficiency of vitamin K-dependent coagulation factors may reveal a complex clinical condition such as an inflammatory bowel disease
Circulating tumor DNA reflects tumor metabolism rather than tumor burden in chemotherapy-naive patients with advanced non-small cell lung cancer (NSCLC):an18F-FDG PET/CT study
We aimed to evaluate the relationships between circulating tumor cells (CTCs) or plasma cell-free DNA (cfDNA) on one side and a comprehensive range of18F-FDG PET/CT-derived parameters on the other side in chemotherapy-naive patients with advanced non-small cell lung cancer (NSCLC). Methods: From a group of 79 patients included in a trial evaluating the role of pretreatment circulating tumor markers as predictors of prognosis in chemotherapy-naive patients with advanced NSCLC, we recruited all those who underwent18F-FDG PET/CT for clinical reasons at our institution before inclusion in the trial (and thus just before chemotherapy). For each patient, a peripheral blood sample was collected at baseline for the evaluation of CTCs and cfDNA. CTCs were isolated by size using a filtration-based device and then morphologically identified and enumerated; cfDNA was isolated from plasma and quantified by a quantitative polymerase chain reaction using human telomerase reverse transcriptase. The following18F-FDG PET/CT-derived parameters were computed: maximum diameter of the primary lesion (T), of the largest lymph node (N), and of the largest metastatic lesion (M); SUVmax; SUVmean; size-incorporated SUVmax; metabolic tumor volume; and total lesion glycolysis. All parameters were independently measured for T, N, and M. The associations among CTCs, cfDNA, and18F-FDG PET/CT-derived parameters were evaluated by multivariate-analysis. Patients were divided into 2 groups according to the presence of either limited metastatic involvement (M1a or M1b due to extrathoracic lymph nodes only) or disseminated metastatic disease. The presence or absence of metabolically active bone lesions was also recorded for each patient, and patient subgroups were compared. Results: Thirty-seven patients recruited in the trial matched our PET-based criteria (24 men; age, 64.5 6 8.1 y). SUVmaxfor the largest metastatic lesion was the only variable independently associated with baseline cfDNA levels (P 5 0.016). Higher levels of cfDNA were detected in the subgroup of patients with metabolically active bone lesions (P 5 0.02), but no difference was highlighted when patients with more limited metastatic disease were compared with patients with disseminated metastatic disease. Conclusion: The correlation of cfDNA levels with tumor metabolism, but not with metabolic tumor volume at regional or distant levels, suggests that cfDNA may better reflect tumor biologic behavior or aggressiveness rather than tumor burden in metastatic NSCLC
Correlation between B7-H4 and Survival of Non-Small-Cell Lung Cancer Patients Treated with Nivolumab
Reliable predictors of benefit from immune checkpoint inhibitors in non-small-cell lung cancer (NSCLC) are still limited. We aimed to evaluate the association between the expression of selected molecules involved in immune response and clinical outcomes in NSCLC patients receiving nivolumab. In our study, the outcomes of 46 NSCLC patients treated with nivolumab in second or subsequent lines (Nivolumab Cohort) were compared with the expression of PD-L1, PD-L2, PD-1, B7-H3, and B7-H4 assessed by immunohistochemistry (IHC). Samples from 17 patients (37.0%) in the Nivolumab Cohort were positive for B7-H4 expression. At univariate analyses, only B7-H4 expression was associated with significantly decreased progression-free survival (PFS; 1.7 vs. 2.0 months; p = 0.026) and with a disadvantage in terms of overall survival (OS) close to statistical significance (4.4 vs. 9.8 months; p = 0.064). At multivariate analyses, B7-H4 expression was significantly associated with decreased PFS (hazard ratio (HR) = 2.28; p = 0.021) and OS (HR = 2.38; p = 0.022). Subsequently, B7-H4 expression was compared with clinical outcomes of 27 NSCLC patients receiving platinum-based chemotherapy (Chemotherapy Cohort), but no significant association was observed. Our results suggest a negative predictive role of B7-H4 in a population of NSCLC treated with immune checkpoint inhibitors, which deserves further research
Imaging of vascular abnormalities in ocular surface disease
The vascular system of the ocular surface plays a central role in infectious, autoimmune, inflammatory, traumatic and neoplastic diseases. The development, application, and mon-itoring of treatments for vascular abnormalities depends on the in vivo analysis of the oc-ular surface vasculature. Until recently, ocular surface vascular imaging was confined to biomicroscopic and color photographic assessment, both limited by poor reproducibility and the inability to image lymphatic vasculature in vivo . The evolvement and clinical im-plementation of innovative imaging modalities including confocal microscopy, intravenous, and optical coherence tomography-based angiography now allows standardized quantita-tive and functional vascular assessment with potential applicability to automated analysis algorithms and diagnostics. (c) 2021 Elsevier Inc. All rights reserved.
Integrated Somatic and Germline Whole-Exome Sequencing Analysis in Women with Lung Cancer after a Previous Breast Cancer
open20Women treated for breast cancer (BC) are at risk of developing secondary tumors, such as lung cancer (LC). Since rare germline variants have been linked to multiple cancer development, we hypothesized that BC survivors might be prone to develop LC as a result of harboring rare variants. Sixty patients with LC with previous BC (the study population; SP) and 53 women with either BC or LC and no secondary cancer (control population; CP) were enrolled. Whole exome sequencing was performed in both tumors and unaffected tissues from 28/60 SP patients, and in germline DNA from 32/53 CP. Candidate genes were validated in the remaining individuals from both populations. We found two main mutational signature profiles: S1 (C>T) in all BCs and 16/28 LCs, and S2 (C>A) which is strongly associated with smoking, in 12/28 LCs. The burden test over rare germline variants in S1-LC vs CP identified 248 genes. Validation confirmed GSN as significantly associated with LC in never-smokers. In conclusion, our data suggest two signatures involved in LC onset in women with previous BC. One of these signatures is linked to smoking. Conversely, regardless of smoking habit, in a subgroup of BC survivors genetic susceptibility may contribute to LC risk.openCoco, Simona; Bonfiglio, Silvia; Cittaro, Davide; Vanni, Irene; Mora, Marco; Genova, Carlo; Dal Bello, Maria Giovanna; Boccardo, Simona; Alama, Angela; Rijavec, Erika; Sini, Claudio; Rossella, Valeria; Barletta, Giulia; Biello, Federica; Truini, Anna; Bruzzo, Cristina; Gallo, Maurizio; Lazarevic, Dejan; Ballestrero, Alberto; Grossi, FrancescoCoco, Simona; Bonfiglio, Silvia; Cittaro, Davide; Vanni, Irene; Mora, Marco; Genova, Carlo; Dal Bello, Maria Giovanna; Boccardo, Simona; Alama, Angela; Rijavec, Erika; Sini, Claudio; Rossella, Valeria; Barletta, Giulia; Biello, Federica; Truini, Anna; Bruzzo, Cristina; Gallo, Maurizio; Lazarevic, Dejan; Ballestrero, Alberto; Grossi, Francesc
Clinical outcomes of pre-loaded ultra-thin DSAEK and pre-loaded DMEK.
ObjectiveTo compare clinical outcomes and complications between pre-loaded ultra-thin Descemet stripping automated endothelialkeratoplasty (pl-UT-DSAEK) and pre-loaded Descemet membrane endothelial keratoplasty (pl-DMEK).Methods and analysisComparative study in patients with endothelial dysfunction associated with Fuchs endothelial corneal dystrophy and pseudophakic bullous keratopathy who underwent pl-UT-DSAEK or pl-DMEK transplants. For both groups, the tissues were pre-loaded at the Fondazione Banca degli Occhi del Veneto (Venice, Italy) and shipped to The Royal Liverpool University Hospital (Liverpool, UK). Best corrected visual acuity (BCVA) and re-bubbling rates were the main outcome measures.Results56 eyes of 56 patients were included. 31 received pl-UT-DSAEK and 25 received pl-DMEK. At 12 months, BCVA (LogMAR) was significantly better for pl-DMEK (0.17±0.20 LogMAR) compared with pl-UT-DSAEK (0.37±0.37 LogMAR, pConclusionPl-DMEK offers better BCVA than pl-UT-DSAEK. The higher re-bubbling rate associated with pre-loaded DMEK is of concern
Deep Learning Using Preoperative AS-OCT Predicts Graft Detachment in DMEK.
PurposeTo evaluate a novel deep learning algorithm to distinguish between eyes that may or may not have a graft detachment based on pre-Descemet membrane endothelial keratoplasty (DMEK) anterior segment optical coherence tomography (AS-OCT) images.MethodsRetrospective cohort study. A multiple-instance learning artificial intelligence (MIL-AI) model using a ResNet-101 backbone was designed. AS-OCT images were split into training and testing sets. The MIL-AI model was trained and validated on the training set. Model performance and heatmaps were calculated from the testing set. Classification performance metrics included F1 score (harmonic mean of recall and precision), specificity, sensitivity, and area under curve (AUC). Finally, MIL-AI performance was compared to manual classification by an experienced ophthalmologist.ResultsIn total, 9466 images of 74 eyes (128 images per eye) were included in the study. Images from 50 eyes were used to train and validate the MIL-AI system, while the remaining 24 eyes were used as the test set to determine its performance and generate heatmaps for visualization. The performance metrics on the test set (95% confidence interval) were as follows: F1 score, 0.77 (0.57-0.91); precision, 0.67 (0.44-0.88); specificity, 0.45 (0.15-0.75); sensitivity, 0.92 (0.73-1.00); and AUC, 0.63 (0.52-0.86). MIL-AI performance was more sensitive (92% vs. 31%) but less specific (45% vs. 64%) than the ophthalmologist's performance.ConclusionsThe MIL-AI predicts with high sensitivity the eyes that may have post-DMEK graft detachment requiring rebubbling. Larger-scale clinical trials are warranted to validate the model.Translational relevanceMIL-AI models represent an opportunity for implementation in routine DMEK suitability screening
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