749 research outputs found
Neuroimaging phenotypes of CSF1R-related leukoencephalopathy: Systematic review, meta-analysis, and imaging recommendations
Colony-stimulating factor 1 receptor (CSF1R)-related leukoencephalopathy is a rare but fatal microgliopathy. The diagnosis is often delayed due to multifaceted symptoms that can mimic several other neurological disorders. Imaging provides diagnostic clues that help identify cases. The objective of this study was to integrate the literature on neuroimaging phenotypes of CSF1R-related leukoencephalopathy. A systematic review and meta-analysis were performed for neuroimaging findings of CSF1R-related leukoencephalopathy via PubMed, Web of Science, and Embase on 25 August 2021. The search included cases with confirmed CSF1R mutations reported under the previous terms hereditary diffuse leukoencephalopathy with spheroids, pigmentary orthochromatic leukodystrophy, and adult-onset leukoencephalopathy with axonal spheroids and pigmented glia. In 78 studies providing neuroimaging data, 195 cases were identified carrying CSF1R mutations in 14 exons and five introns. Women had a statistically significant earlier age of onset (p = 0.041, 40 vs 43 years). Mean delay between symptom onset and neuroimaging was 2.3 years. Main magnetic resonance imaging (MRI) findings were frontoparietal white matter lesions, callosal thinning, and foci of restricted diffusion. The hallmark computed tomography (CT) finding was white matter calcifications. Widespread cerebral hypometabolism and hypoperfusion were reported using positron emission tomography and single-photon emission computed tomography. In conclusion, CSF1R-related leukoencephalopathy is associated with progressive white matter lesions and brain atrophy that can resemble other neurodegenerative/-inflammatory disorders. However, long-lasting diffusion restriction and parenchymal calcifications are more specific findings that can aid the differential diagnosis. Native brain CT and brain MRI (with and without a contrast agent) are recommended with proposed protocols and pictorial examples are provided
A blockchain protocol for authenticating space communications between satellites constellations
Blockchain has found many applications, apart from Bitcoin, in different fields and it has the potential to be very useful in the satellite communications and space industries. Decentralized and secure protocols for processing and manipulating space transactions of satellite swarms in the form of Space Digital Tokens (SDT) can be built using blockchain technology. Tokenizing space transactions using SDTs will open the door to different new blockchain-based solutions for the advancement of constellation-based satellite communications in the space industry. Developing blockchain solutions using smart contracts could be used in securely authenticating various P2P satellite communications and transactions within/between satellite swarms. To manage and secure these transactions, using the proposed SDT concept, this paper suggested a blockchain-based protocol called Proof of Space Transactions (PoST). This protocol was adopted to manage and authenticate the transactions of satellite constellations in a P2P connection. The PoST protocol was prototyped using the Ethereum blockchain and experimented with to evaluate its performance using four metrics: read latency, read throughput, transaction latency, and transaction throughput. The simulation results clarified the efficiency of the proposed PoST protocol in processing and verifying satellite transactions in a short time according to read and transaction latency results. Moreover, the security results showed that the proposed PoST protocol is secure and efficient in verifying satellite transactions according to true positive rate (TPR), true negative rate (TNR), and accuracy metrics. These findings may shape a real attempt to develop a new generation of Blockchain-based satellite constellation systems
Quantum interferometry with three-dimensional geometry
Quantum interferometry uses quantum resources to improve phase estimation
with respect to classical methods. Here we propose and theoretically
investigate a new quantum interferometric scheme based on three-dimensional
waveguide devices. These can be implemented by femtosecond laser waveguide
writing, recently adopted for quantum applications. In particular, multiarm
interferometers include "tritter" and "quarter" as basic elements,
corresponding to the generalization of a beam splitter to a 3- and 4-port
splitter, respectively. By injecting Fock states in the input ports of such
interferometers, fringe patterns characterized by nonclassical visibilities are
expected. This enables outperforming the quantum Fisher information obtained
with classical fields in phase estimation. We also discuss the possibility of
achieving the simultaneous estimation of more than one optical phase. This
approach is expected to open new perspectives to quantum enhanced sensing and
metrology performed in integrated photonic.Comment: 7 pages (+4 Supplementary Information), 5 figure
Radiosurgery and fractionated stereotactic body radiotherapy for patients with lung oligometastases
Background: Patients with oligometastatic disease can potentially be cured by using an ablative therapy for all active lesions. Stereotactic body radiotherapy (SBRT) is a non-invasive treatment option that lately proved to be as effective and safe as surgery in treating lung metastases (LM). However, it is not clear which patients benefit most and what are the most suitable fractionation regimens. The aim of this study was to analyze treatment outcomes after single fraction radiosurgery (SFRS) and fractionated SBRT (fSBRT) in patients with lung oligometastases and identify prognostic clinical features for better survival outcomes.
Methods: Fifty-two patients with 94 LM treated with SFRS or fSBRT between 2010 and 2016 were analyzed. The characteristics of primary tumor, LM, treatment, toxicity profiles and outcomes were assessed. Kaplan-Meier and Cox regression analyses were used for estimation of local control (LC), overall survival (OS) and progression-free survival.
Results: Ninety-four LM in 52 patients were treated using SFRS/fSBRT with a median of 2 lesions per patient (range: 1-5). The median planning target volume (PTV)-encompassing dose for SFRS was 24 Gy (range: 17-26) compared to 45 Gy (range: 20-60) in 2-12 fractions with fSBRT. The median follow-up time was 21 months (range: 3-68). LC rates at 1 and 2 years for SFSR vs. fSBRT were 89 and 83% vs. 75 and 59%, respectively (p = 0.026). LM treated with SFSR were significantly smaller (p = 0.001). The 1 and 2-year OS rates for all patients were 84 and 71%, respectively. In univariate analysis treatment with SFRS, an interval of ≥12 months between diagnosis of LM and treatment, non-colorectal cancer histology and BED 70% and time to first metastasis ≥12 months. There was no grade 3 acute or late toxicity.
Conclusions: Longer time to first metastasis, good KPS and N0 predicted better OS. Good LC and low toxicity rates were achieved after short SBRT schedules
Tumor radiomic features complement clinico-radiological factors in predicting long-term local control and laryngectomy free survival in locally advanced laryngo-pharyngeal cancers
OBJECTIVE: To study if pre-treatment CT texture features in locally advanced squamous cell carcinoma of laryngo-pharynx can predict long-term local control and laryngectomy free survival (LFS). METHODS: Image texture features of 60 patients treated with chemoradiation (CTRT) within an ethically approved study were studied on contrast-enhanced images using a texture analysis research software (TexRad, UK). A filtration-histogram technique was used where the filtration step extracted and enhanced features of different sizes and intensity variations corresponding to a particular spatial scale filter (SSF): SSF = 0 (without filtration), SSF = 2 mm (fine texture), SSF = 3-5 mm (medium texture) and SSF = 6 mm (coarse texture). Quantification by statistical and histogram technique comprised mean intensity, standard-deviation, entropy, mean positive pixels, skewness and kurtosis. The ability of texture analysis to predict LFS or local control was determined using Kaplan-Meier analysis and multivariate cox model. RESULTS: Median follow-up of patients was 24 months (95% CI:20-28). 39 (65%) patients were locally controlled at last follow-up. 10 (16%) had undergone salvage laryngectomy after CTRT. For both local control & LFS, threshold optimal cut-off values of texture features were analyzed. Medium filtered-texture feature that were associated with poorer laryngectomy free survival were entropy ≥4.54, (p = 0.006), kurtosis ≥4.18; p = 0.019, skewness ≤-0.59, p = 0.001, and standard deviation ≥43.18; p = 0.009). Inferior local control was associated with medium filtered features entropy ≥4.54; p 0.01 and skewness ≤ - 0.12; p = 0.02. Using fine filters, entropy ≥4.29 and kurtosis ≥-0.27 were also associated with inferior local control (p = 0.01 for both parameters). Multivariate analysis showed medium filter entropy as an independent predictor for LFS and local control (p < 0.001 & p = 0.001). CONCLUSION: Medium texture entropy is a predictor for inferior local control and laryngectomy free survival in locally advanced laryngo-pharyngeal cancer and this can complement clinico-radiological factors in predicting prognosticating these tumors. ADVANCES IN KNOWLEDGE: Texture features play an important role as a surrogate imaging biomarker for predicting local control and laryngectomy free survival in locally advanced laryngo-pharyngeal tumors treated with definitive chemoradiation
NK cell receptors in anti-tumor and healthy tissue protection: Mechanisms and therapeutic advances
natural killer (NK) cells are integral to the innate immune system, renowned for their ability to target and eliminate cancer cells without the need for antigen presentation, sparing normal tissues. these cells are crucial in cancer immunosurveillance due to their diverse array of activating and inhibitory receptors that modulate their cytotoxic activity. however, the tumor microenvironment can suppress NK cell function through various mechanisms. over recent decades, research has focused on overcoming these tumor escape mechanisms. Initially, efforts concentrated on enhancing T cell activity, leading to impressive results with immunotherapeutic approaches aimed at boosting T cell responses. nevertheless, a substantial number of patients do not benefit from these treatments and continue to seek effective alternatives. In this context, NK cells present a promising avenue for developing new treatments, given their potent cytotoxic capabilities, safety profile, and activity against T cell- resistant tumors, such as those lacking HLA-I expression. recent advancements in immunotherapy include strategies to restore and amplify NK cell activity through immune checkpoint inhibitors, cytokines, adoptive NK cell therapy, and CAR-NK cell technology. this review provides a comprehensive overview of NK cell receptors, the tumor escape mechanisms that hinder NK cell function, and the evolving field of NK cell-based cancer immunotherapy, highlighting ongoing efforts to develop more effective and targeted cancer treatment strategies
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