185 research outputs found
Harmonic analysis of oscillators through standard numerical continuation tools
In this paper, we describe a numerical continuation method that enables
harmonic analysis of nonlinear periodic oscillators. This method is formulated
as a boundary value problem that can be readily implemented by resorting to a
standard continuation package - without modification - such as AUTO, which we
used. Our technique works for any kind of oscillator, including electronic,
mechanical and biochemical systems. We provide two case studies. The first
study concerns itself with the autonomous electronic oscillator known as the
Colpitts oscillator, and the second one with a nonlinear damped oscillator, a
non-autonomous mechanical oscillator. As shown in the case studies, the
proposed technique can aid both the analysis and the design of the oscillators,
by following curves for which a certain constraint, related to harmonic
analysis, is fulfilled.Comment: 20 pages, 4 figure
X-linked adrenoleukodystrophy and primary adrenal insufficiency
X-linked adrenoleukodystrophy (X-ALD; OMIM:300100) is a progressive neurodegenerative disorder caused by a congenital defect in the ATP-binding cassette transporters sub-family D member 1 gene (ABCD1) producing adrenoleukodystrophy protein (ALDP). According to population studies, X-ALD has an estimated birth prevalence of 1 in 17.000 subjects (considering both hemizygous males and heterozygous females), and there is no evidence that this prevalence varies among regions or ethnic groups. ALDP deficiency results in a defective peroxisomal β-oxidation of very long chain fatty acids (VLCFA). As a consequence of this metabolic abnormality, VLCFAs accumulate in nervous system (brain white matter and spinal cord), testis and adrenal cortex. All X-ALD affected patients carry a mutation on the ABCD1 gene. Nevertheless, patients with a defect on the ABCD1 gene can have a dramatic difference in the clinical presentation of the disease. In fact, X-ALD can vary from the most severe cerebral paediatric form (CerALD), to adult adrenomyeloneuropathy (AMN), Addison-only and asymptomatic forms. Primary adrenal insufficiency (PAI) is one of the main features of X-ALD, with a prevalence of 70% in ALD/AMN patients and 5% in female carriers. The pathogenesis of X-ALD related PAI is still unclear, even if a few published data suggests a defective adrenal response to ACTH, related to VLCFA accumulation with progressive disruption of adrenal cell membrane function and ACTH receptor activity. The reason why PAI develops only in a proportion of ALD/AMN patients remains incompletely understood. A growing consensus supports VLCFA assessment in all male children presenting with PAI, as early diagnosis and start of therapy may be essential for X-ALD patients. Children and adults with PAI require individualized glucocorticoid replacement therapy, while mineralocorticoid therapy is needed only in a few cases after consideration of hormonal and electrolytes status. Novel approaches, such as prolonged release glucocorticoids, offer potential benefit in optimizing hormonal replacement for X-ALD-related PAI. Although the association between PAI and X-ALD has been observed in clinical practice, the underlying mechanisms remain poorly understood. This paper aims to explore the multifaceted relationship between PAI and X-ALD, shedding light on shared pathophysiology, clinical manifestations, and potential therapeutic interventions
Blood Pressure and Left Ventricular Characteristics in Young Patients with Classical Congenital Adrenal Hyperplasia due to 21-Hydroxylase Deficiency
High steroid doses are often necessary in congenital adrenal hyperplasia (CAH) to suppress androgens and may increase blood pressure (BP). We evaluated 24-hour BP profile (ambBP), BP during exercise (excBP), and echocardiography in 20 young CAH patients. Systolic and diastolic BP during ambBP and excBP was normal in all patients. None presented myocardial hypertrophy. Nocturnal diastolic BP was affected by testosterone (P: .016, 95% CI: 0.002 to 0.021, β = 0.01). Left ventricular mass (LVM ) was affected by height SDS (P: .007, 95% CI: 2.67 to 14.17, β = 8.42), age (P: < .0001, 95% CI: 2.12 to 5.82, β = 3.97), and testosterone (P: .008, 95% CI: 0.01 to 0.09, β = 0.053). Left ventricular mass index (LVMI) correlated with BMI SDS (P: .044, 95% CI: 0.09 to 6.17, β = 3.13) and testosterone (P: .031, 95% CI: 0.002 to 0.035, β = 0.018). Hydrocortisone dose did not influence ambBP, excBP, or myocardial hypertrophy
Data-driven Predictive Latency for 5G: A Theoretical and Experimental Analysis Using Network Measurements
The advent of novel 5G services and applications with binding latency
requirements and guaranteed Quality of Service (QoS) hastened the need to
incorporate autonomous and proactive decision-making in network management
procedures. The objective of our study is to provide a thorough analysis of
predictive latency within 5G networks by utilizing real-world network data that
is accessible to mobile network operators (MNOs). In particular, (i) we present
an analytical formulation of the user-plane latency as a Hypoexponential
distribution, which is validated by means of a comparative analysis with
empirical measurements, and (ii) we conduct experimental results of
probabilistic regression, anomaly detection, and predictive forecasting
leveraging on emerging domains in Machine Learning (ML), such as Bayesian
Learning (BL) and Machine Learning on Graphs (GML). We test our predictive
framework using data gathered from scenarios of vehicular mobility, dense-urban
traffic, and social gathering events. Our results provide valuable insights
into the efficacy of predictive algorithms in practical applications
Fertility-Sparing Treatment for Early-Stage Cervical Cancer ≥ 2 cm: A Problem with a Thousand Nuances—A Systematic Review of Oncological Outcomes.
BACKGROUND: Fertility-sparing treatments (FSTs) have played a crucial role in the management of early-stage cervical cancer (ECC). The guidelines have recognized various approaches, depending on the tumor stage and other risk factors such as histotype and lymphovascular positivity. Much more debate has centered around the boundary within which these treatments should be considered. Indeed, these are methods to be reserved for ECC, but tumor size may represent the most significant limitation. In particular, there is no consensus on the strategy to be adopted in the case of ECC ≥ 2 cm. Therefore, this systematic review was to collect the literature evidence regarding the management of these patients. METHODS: Following the recommendations in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, we systematically searched the Pubmed and Scopus databases was conducted in April 2022, from the date of the first publication. We made no limitation on the country. We included all studies containing data on disease-free survival, overall survival, recurrence rate (RR), or complete response rate (CRR) to chemotherapy. RESULTS: Twenty-six studies fulfilled the inclusion criteria, and 691 patients were analyzed regarding FST. Surgery-based FST showed an RR of between 0 and 42.9%, which drops to 12.9% after excluding the vaginal or minimally invasive approaches. Furthermore, papers regarding FST based on the neoadjuvant chemotherapy (NACT) approach showed a CRR of between 21.4 and 84.5%, and an RR of between 0 and 22.2% CONCLUSION: This paper focused on the significant heterogeneity present in the clinical management of FST of ECC ≥ 2 cm. Nevertheless, from an oncological point of view, approaches limited to the minimally invasive or vaginal techniques showed the highest RR. Vice versa, the lack of standardization of NACT schemes and the wealth of confounders to be attributed to the histological features of the tumor make it difficult, if not impossible, to set a standard of treatment. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1245/s10434-022-12436-w
ASO Author Reflections: Fertility-Sparing Treatment for Early-Stage Cervical Cancer 2 cm or Larger in Size: A Problem Still Open
the early pleistocene whale fall community of bargiano umbria central italy paleoecological insights from benthic foraminifera and brachyuran crabs
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Role of SIRT3 in Microgravity Response: A New Player in Muscle Tissue Recovery
Life on Earth has evolved in the presence of a gravity constraint. Any change in the value of such a constraint has important physiological effects. Gravity reduction (microgravity) alters the performance of muscle, bone and, immune systems among others. Therefore, countermeasures to limit such deleterious effects of microgravity are needed considering future Lunar and Martian missions. Our study aims to demonstrate that the activation of mitochondrial Sirtuin 3 (SIRT3) can be exploited to reduce muscle damage and to maintain muscle differentiation following microgravity exposure. To this effect, we used a RCCS machine to simulate microgravity on ground on a muscle and cardiac cell line. During microgravity, cells were treated with a newly synthesized SIRT3 activator, called MC2791 and vitality, differentiation, ROS and, autophagy/mitophagy were measured. Our results indicate that SIRT3 activation reduces microgravity-induced cell death while maintaining the expression of muscle cell differentiation markers. In conclusion, our study demonstrates that SIRT3 activation could represent a targeted molecular strategy to reduce muscle tissue damage caused by microgravity
transthoracic ultrasound versus intraoperative ultrasound in patients with pulmonary fibrosis reappraisal of artifacts
In the last years, transthoracic ultrasound (TUS) has regained a growing interest from both clinicians and radiologists as a useful and non-invasive diagnostic tool for the study of many pleuro-pulmonary conditions, including interstitial lung diseases. Intraoperative lung ultrasound (ILU) is an ultrasound technique, developed for lung surface assessment during video-assisted thoracoscopic surgery procedures. It has been developed considering ultrasound basic physics principles for images generation and interpretation. Most of the TUS findings are due to the high difference in acoustic impedance between the chest-wall structures and the air in the lungs. In this brief communication, we compared ILU and TUS images in interstitial lung diseases. Most of the TUS artifacts-based diagnostic algorithms should be reappraised
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