String Dilaton Fluid Cosmology

We investigate $(n+1)$-dimensional string-dilaton cosmology with effective dilaton potential in presence of perfect-fluid matter.We get exact solutions parametrized by the constant \gam of the state equation p=(\gam-1)\rho, the spatial dimension number $n$, the bulk of matter, and the spatial curvature constant $k$. Several interesting cosmological behaviours are selected. Finally we discuss the recovering of ordinary Einstein gravity starting from string dominated regime and a sort of asymptotic freedom due to string effective coupling.Comment: 16 pages, Latex, submitted to Int. Jou. Mod. Phys.

Hyperpigmented spots at fundus examination: a new ocular sign in neurofibromatosis type I

Background: Neurofibromatosis Type I (NF1), also termed von Recklinghausen disease, is a rare genetic disorder that is transmitted by autosomal dominant inheritance, with complete penetrance and variable expressivity. It is caused by mutation in the NF1 gene on chromosome 17 encoding for neurofibromin, a protein with oncosuppressive activity, and it is 50% sporadic or inherited. The disease is characterized by a broad spectrum of clinical manifestations, mainly involving the nervous system, the eye and skin, and a predisposition to develop multiple benign and malignant neoplasms. Ocular diagnostic hallmarks of NF1 include optic gliomas, iris Lisch nodules, orbital and eyelid neurofibromas, eyelid café-au-lait spots. Choroidal nodules and microvascular abnormalities have recently been identified as additional NF1-related ocular manifestations. The present study was designed to describe the features and clinical significance of a new sign related to the visual apparatus in NF-1, represented by hyperpigmented spots (HSs) of the fundus oculi. Results: HSs were detected in 60 (24.1%) out of 249 patients with NF1, with a positive predictive value of 100% and a negative predictive value of 44.2%. None of the healthy subjects (150 subjects) showed the presence of HSs. HSs were visible under indirect ophthalmoscopy, ultra-wide field (UWF) pseudocolor imaging and red-only laser image, near-infrared reflectance (NIR)-OCT, but they were not appreciable on UWF green reflectance. The location and features of pigmentary lesions matched with the already studied NF1-related choroidal nodules. No significant difference was found between the group of patients (n = 60) with ocular HSs and the group of patients (n = 189) without ocular pigmented spots in terms of age, gender or severity grading of the disease. A statistically significant association was demonstrated between the presence of HSs and neurofibromas (p = 0.047), and between the presence of HSs and NF1-related retinal microvascular abnormalities (p = 0.017). Conclusions: We described a new ocular sign represented by HSs of the fundus in NF1. The presence of HSs was not a negative prognostic factor of the disease. Following multimodal imaging, we demonstrated that HSs and choroidal nodules were consistent with the same type of lesion, and simple indirect ophthalmoscopy allowed for screening of HSs in NF1

Electromagnetic shape resonances of a dielectric sphere and radiation of portable telephones

The frequency band used by cellular telephones includes the eigenfrequencies of a dielectric sphere with physical characteristics close to those of a human head. Proceeding from the spatial features of the natural modes of such a sphere we propose an independent and clear evident accuracy test for the complicated numerical calculations which are conducted when estimating the potential hazard due to the use of cellular telephones, in particular, for the check of a proper handling of the electromagnetic shape resonances of a human head.Comment: 10 pages, 1 figure with 2 eps file

Cancer stem cells-driven tumor growth and immune escape: the Janus face of neurotrophins

Cancer Stem Cells (CSCs) are self-renewing cancer cells responsible for expansion of the malignant mass in a dynamic process shaping the tumor microenvironment. CSCs may hijack the host immune surveillance resulting in typically aggressive tumors with poor prognosis. In this review, we focus on neurotrophic control of cellular substrates and molecular mechanisms involved in CSC-driven tumor growth as well as in host immune surveillance. Neurotrophins have been demonstrated to be key tumor promoting signaling platforms. Particularly, Nerve Growth Factor (NGF) and its specific receptor Tropomyosin related kinase A (TrkA) have been implicated in initiation and progression of many aggressive cancers. On the other hand, an active NGF pathway has been recently proven to be critical to oncogenic inflammation control and in promoting immune response against cancer, pinpointing possible pro-tumoral effects of NGF/TrkA-inhibitory therapy. A better understanding of the molecular mechanisms involved in the control of tumor growth/immunoediting is essential to identify new predictive and prognostic intervention and to design more effective therapies. Fine and timely modulation of CSCs-driven tumor growth and of peripheral lymph nodes activation by the immune system will possibly open the way to precision medicine in neurotrophic therapy and improve patient's prognosis in both TrkA- dependent and independent cancers

The diagnostic certainty levels of junior clinicians: A retrospective cohort study

BACKGROUND: Clinical decision-making is influenced by many factors, including clinicians' perceptions of the certainty around what is the best course of action to pursue. OBJECTIVE: To characterise the documentation of working diagnoses and the associated level of real-time certainty expressed by clinicians and to gauge patient opinion about the importance of research into clinician decision certainty. METHOD: This was a single-centre retrospective cohort study of non-consultant grade clinicians and their assessments of patients admitted from the emergency department between 01 March 2019 and 31 March 2019. De-identified electronic health record proformas were extracted that included the type of diagnosis documented and the certainty adjective used. Patient opinion was canvassed from a focus group. RESULTS: During the study period, 850 clerking proformas were analysed; 420 presented a single diagnosis, while 430 presented multiple diagnoses. Of the 420 single diagnoses, 67 (16%) were documented as either a symptom or physical sign and 16 (4%) were laboratory-result-defined diagnoses. No uncertainty was expressed in 309 (74%) of the diagnoses. Of 430 multiple diagnoses, uncertainty was expressed in 346 (80%) compared to 84 (20%) in which no uncertainty was expressed. The patient focus group were unanimous in their support of this research. CONCLUSION: The documentation of working diagnoses is highly variable among non-consultant grade clinicians. In nearly three quarters of assessments with single diagnoses, no element of uncertainty was implied or quantified. More uncertainty was expressed in multiple diagnoses than single diagnoses. IMPLICATIONS: Increased standardisation of documentation will help future studies to better analyse and quantify diagnostic certainty in both single and multiple working diagnoses. This could lead to subsequent examination of their association with important process or clinical outcome measures

Casimir energy of a dilute dielectric ball in the mode summation method

In the $(\epsilon_1-\epsilon_2)^2$--approximation the Casimir energy of a dilute dielectric ball is derived using a simple and clear method of the mode summation. The addition theorem for the Bessel functions enables one to present in a closed form the sum over the angular momentum before the integration over the imaginary frequencies. The linear in $(\epsilon_1-\epsilon_2)$ contribution into the vacuum energy is removed by an appropriate subtraction. The role of the contact terms used in other approaches to this problem is elucidated.Comment: 14 pages, REVTeX, no figures, no tables; presentation is made better, new references are adde