Most popular statistical models in epidemic evolution focus on the dynamics of average relevant quantities and overlooks the role of small fluctuations on the model parameters. Models for Covid-19 ...are no exception. In this paper we show that the role of time-correlated fluctuations, far from being negligible, can in fact determine the spreading of an epidemic and, most importantly, the resurgence of the exponential diffusion in the presence of time-limited episodes in promiscuity behaviours. The results found in this work are not only relevant and specific for the Covid-19 epidemic but are more general and can be applied to other epidemics.
We present the exact analytical expression for the spectrum of a sparse non-hermitian random matrix ensemble, generalizing two standard results in random-matrix theory: this analytical expression ...constitutes a non-hermitian version of the Kesten-McKay measure as well as a sparse realization of Girko's elliptic law. Our exact result opens new perspectives in the study of several physical problems modelled on sparse random graphs, which are locally treelike. In this context, we show analytically that the convergence rate of a transport process on a very sparse graph depends in a nonmonotonic way upon the degree of symmetry of the graph edges.
Tuberous sclerosis complex (TSC) is an autosomal dominant multisystem disorder characterized by the development of multiple hamartomas in many organs and tissues. It occurs due to inactivating ...mutations in either of the two genes, TSC1 and TSC2, following a second hit in a tumor suppressor gene in most hamartomas. Comprehensive screening for mutations in both the TSC1 and TSC2 loci has been performed in several cohorts of patients and a broad spectrum of pathogenic mutations have been described. In Brazil, there is no data regarding incidence and prevalence of tuberous sclerosis and mutations in TSC1 and TSC2. We analyzed both genes in 53 patients with high suspicion of tuberous sclerosis using multiplex-ligation dependent probe amplification and a customized next generation sequencing panel. Confirmation of all variants was done by the Sanger method. We identified 50 distinct variants in 47 (89%) of the patients. Five were large rearrangements and 45 were point mutations. The symptoms presented by our series of patients were not different between male and female individuals, except for the more common occurrence of shagreen patch in women (p = 0.028). In our series, consistent with other studies, TSC2 mutations were associated with a more severe phenotypic spectrum than TSC1 mutations. This is the first study that sought to characterize the molecular spectrum of Brazilian individuals with tuberous sclerosis.
► Antioxidant potential and antiproliferative effect of five monoterpenes was investigated. ► α-Terpineol presented good antioxidant activity in ORAC test. ► Limonene and α-terpineol presented ...equivalent antiproliferative profile in vitro. ► α-Terpineol had encouraging results against breast carcinoma and chronic myeloid leukemia. ► In vivo assays must be performed to confirm the anti-tumor potential of α-terpineol.
α-Terpineol is a relatively cheap and abundant aroma compound. It is widely used in food, cosmetics, and household products. Many of its monoterpene counterparts have been applied in antiproliferative assays, leading to promising results in the prevention or even treatment of cancers. However, despite its theoretic potential, no paper reports the evaluation of antiproliferative capacity of this alcohol. Thus, antioxidant potential of three monoterpenoids (carvone, perillyl alcohol, and α-terpineol) was measured using two methods: DPPH and ORAC. Also, the antiproliferative effect of these monoterpenoids against nine cancerous cell lines were performed and compared to limonene and doxorubicin. Results showed that all samples tested had very low antioxidant activity in the DPPH assay, but α-terpineol (2.72μmolTrolox equiv./μmol) could be compared to commercial antioxidants in the ORAC assay. The antiproliferative results obtained encourage future in vivo studies for α-terpineol, since this monoterpenoid presented cytostatic effect against six cell lines, especially for breast adenocarcinoma and chronic myeloid leukemia, in a range of 181–588μM.
Purpose
To present the state-of-art of radiomics in the context of pancreatic neuroendocrine tumors (PanNETs), with a focus on the methodological and technical approaches used, to support the search ...of guidelines for optimal applications. Furthermore, an up-to-date overview of the current clinical applications of radiomics in the field of PanNETs is provided.
Methods
Original articles were searched on PubMed and Science Direct with specific keywords. Evaluations of the selected studies have been focused mainly on (i) the general radiomic workflow and the assessment of radiomic features robustness/reproducibility, as well as on the major clinical applications and investigations accomplished so far with radiomics in the field of PanNETs: (ii) grade prediction, (iii) differential diagnosis from other neoplasms, (iv) assessment of tumor behavior and aggressiveness, and (v) treatment response prediction.
Results
Thirty-one articles involving PanNETs radiomic-related objectives were selected. In regard to the grade differentiation task, yielded AUCs are currently in the range of 0.7–0.9. For differential diagnosis, the majority of studies are still focused on the preliminary identification of discriminative radiomic features. Limited information is known on the prediction of tumors aggressiveness and of treatment response.
Conclusions
Radiomics is recently expanding in the setting of PanNETs. From the analysis of the published data, it is emerging how, prior to clinical application, further validations are necessary and methodological implementations require optimization. Nevertheless, this new discipline might have the potential in assisting the current urgent need of improving the management strategies in PanNETs patients.
Background
Over the last months, during the COVID‐19 pandemic, a growing number of chilblain‐like lesions were reported mainly in children and rarely in young adults. The relationship with SARS‐CoV‐2 ...infection was postulated, often without any laboratory, instrumental or clinical confirmation. The disclosure of information about chilblain‐like lesions as a COVID‐19 manifestation in social media has created concern in children’s families and paediatricians.
Objectives
To verify whether the chilblain‐like lesions were caused by SARS‐CoV‐2 infection.
Methods
Prospective study on a case series including children who presented with acral lesions at the Pediatric Dermatology Outpatient and Pediatric Emergency Unit of the University of Bologna, from 1 April to 30 April 2020. We reported demographical, laboratory and clinical features, history of close contact with COVID‐19 patients, presence of similar skin lesions in other family members, precipitating and risk factors for chilblain onset.
Results
We evaluated eight patients (five females, three males) aged between 11 and 15 years. We excluded acute or previous SARS‐CoV‐2 infection with RT‐PCR nasopharyngeal swab, serum antibody levels using chemiluminescent immunoassays. Other acute infections causing purpuric lesions at the extremities were negative in all patients. Skin lesion biopsy for histological and immunohistochemical evaluation was made in two cases and was consistent with chilblain. PCR assay on skin lesion biopsy for parvovirus B19, Mycoplasma pneumoniae and SARS‐CoV‐2 was performed in a patient and resulted negative. We identified common precipitating and risk factors: physical (cold and wet extremities, low BMI), cold and wet indoor and outdoor environment, behaviours, habits and lifestyle. We therefore reached a diagnosis of primary chilblains.
Conclusions
During the COVID‐19 pandemic, a ‘cluster’ of primary chilblains developed in predisposed subjects, mainly teenagers, due to cold exposure in the lockdown period. Laboratory findings support our hypothesis, although it is also possible that an unknown infectious trigger may have contributed to the pathogenesis.