Concepts and Models Regarding the Behavior of Antiseismic Devices for the Base Isolation System

The paper presents the main antiseismic devices, as component elements of the base isolation systems, in such a manner that the functional and constructive parameters are correlated with the inertial and stiffness characteristics of the dynamic isolated building. Also, each device will be characterized through a rheological model, which conditions the eigenvalues and eigenvectors spectrum, as well as the dynamic response to an exterior excitation of a seismic nature. In this context, antiseismic devices defined and characterized by the European Standard EN 15129 will be presented. Based on the requirements formulated in the norm, the devices can be identified and their laws of evolution established and checked as follows: antiseismic devices with permanent rigid connection; antiseismic devices with rigid connections with respect to the instantaneous displacement and antiseismic devices dependent on the velocity and on the velocity variation in time

Parametric correlations between experimental results and the base isolation, in situ, structural ones

The paper addresses the topic of the inconsistency between experimental, laboratory results for antiseismic devices and the dynamic stiffness, internal damping and dissipation parameters through additional devices. The necessary corrections of the stiffness and dissipation (damping) parameters will be presented when the antiseismic devices are equipped to satisfy the adequate functions in a complex structural system (buildings, viaducts, bridges) under the conditions of seismic motions characteristic to the Romanian territory. In this context, the kinematic excitation method, compared to the dynamic evaluation method of the vibration dissipation capacity, produced by a seismic shock is shown

Viscoelastic Model for the Rigid Body Vibrations of a Viaduct Depending on the Support Devices’ Rheological Model

Rezumat"/jats:title" "jats:p" Lucrarea abordează comportarea unui model de solid-rigid cu anumite simetrii structurale. Aceste simetrii permit simplificarea calculelor (ecuaţii de mişcare) şi, deci, a modelelor matematice. Dacă solidul rigid este conectat la structură prin patru legături elastice, modelul rămâne încă simplu şi uşor de rezolvat, vibraţiile putând fi decuplate în patru subsisteme de mişcare. "/jats:p" "jats:p"În final, se prezintă un studiu de caz pentru analiza modală a unui viaduct, modelat precum un corp solid-rigid, rezemat elastic, de pe autostrada Transilvania (km 29+602.75 m). Document type: Articl

Diagnosis and management of pericardial effusion

Pericardial effusion is a common pathology in clinical practice. The etiology of pericardial effusion is diverse, from infectious diseases, malignancies, autoimmune diseases, chronic renal failure, to drug-related or after an invasive cardiac intervention. Clinical presentation of pericardial effusion is variable, depending on the volume of the fluid and the rate of accumulation. Clinical manifestations are dramatic if the pericardial fluid accumulates rapidly. Classical symptoms in pericardial effusion include pleuritic chest pain associated with dyspnea. In case of cardiac tamponade, orthopnea, jugular venous distension, pulsus paradoxus, hypotension, and shock appear. Transthoracic echocardiography is the gold standard investigation for the diagnosis of pericardial effusions. The echocardiographic signs of cardiac tamponade are represented by the collapse of the right atrium and right ventricle, respiratory alteration of mitral and tricuspid flow, and changes of the inferior vena cava. Management of pericardial effusion is guided by several factors, including hemodynamic impact and etiology. Pericardiocentesis guided by echocardiography is a life-saving procedure in cases of large pericardial effusions and cardiac tamponade. This is a review of the diagnosis and treatment of pericardial effusion

Pheochromocytoma – clinical manifestations, diagnosis and current perioperative management

Pheochromocytoma is a neuroendocrine tumor characterized by the excessive production of catecholamines (epinephrine, norepinephrine, and dopamine). The diagnosis is suspected due to hypertensive paroxysms, associated with vegetative phenomena, due to the catecholaminergic hypersecretion. Diagnosis involves biochemical tests that reveal elevated levels of catecholamine metabolites (metanephrine and normetanephrine). Functional imaging, such as 123I-metaiodobenzylguanidine scintigraphy (123I-MIBG), has increased specificity in identifying the catecholamine-producing tumor and its metastases. The gold-standard treatment for patients with pheochromocytoma is represented by the surgical removal of the tumor. Before surgical resection, it is important to optimize blood pressure and intravascular volume in order to avoid negative hemodynamic events

Intestinal microbiota – a possible contributor to cardiovascular diseases?

The intestinal microbiota represents an interesting and emergent field of research, with already known implications in metabolic and immunological functions. Recently, there is increasing evidence that specific gut microbial populations are associated with cardiovascular diseases. Numerous completed and ongoing studies aim to evaluate the potential of intestinal microbiota assessment to improve the prevention, diagnosis, and therapeutic arsenal of cardiovascular diseases, considering dysbiosis as a cardiovascular risk factor. There is strong evidence for a correlation between intestinal flora imbalance and metabolic changes secondary to bacterial metabolites. In this minireview, we discuss recent data about the connections between intestinal microbiota and cardiovascular disease

The Serine/Threonine Protein Kinase (Akt)/ Protein Kinase B (PkB) Signaling Pathway in Breast Cancer

According to statistical data published in 2019, breast cancer is among the leading causes of death in women worldwide. The serine/threonine kinase (AKT) or protein kinase B (PkB) signaling pathway is activated by phosphorylation processes, which further is associated with cell growth, proliferation, and survival, but also with activation of glucose metabolism. Mutations of the AKT signaling pathway components (especially PI3KCA and PTEN) have been observed in breast cancer patients, which are associated with resistance to hormonal treatment. Many clinical trials are testing the effect of AKT inhibition in order to block the growth and proliferation of breast cancer cells. The purpose of this review is to present the incidence of this neoplastic disease, to describe AKT signaling pathways activation, mutations that occur at its level, and inhibitors that can block this protein kinase

Underactive bladder - an underestimated entity

Introduction. The concept of underactive bladder is relatively new. Currently there is no generally accepted definition of this pathology. Diagnosis depends on urodynamic findings, and symptoms are usually rare and intricated with the symptoms of other urinary pathology. Matherials and methods. This review examines the current literature on underactive bladder regarding pathology, definition, diagnosis, current guidelines, and any further potential medical developments. Conclusions. Underactive bladder is a poorly understood pathologic condition. Only since 2002 has there been any consensus regarding the definition. The diagnosis relies only on urodynamics; clinical diagnosis is a challenge even for a consultant; and treatment does not seem to alleviate much of the suffering. This disease remains underrecognized and undertreated. More research is needed to identify less invasive diagnosis tools and treatment for this pathology

Cardio metabolic risk factors for atrial fibrillation in type 2 diabetes mellitus: Focus on hypertension, metabolic syndrome and obesity

Objective. Atrial fibrillation (AF) in type 2 diabetes mellitus (T2DM) has been little explored so far. However, there are several cardio metabolic risk factors for AF in T2DM patients, such as arterial hypertension, obesity or the metabolic syndrome. Our objective was to evaluate cardio metabolic risk factors for AF in T2DM patients. Methods. We studied the medical records of T2DM patients hospitalized in the Internal Medicine department of an emergency referral hospital in Bucharest, Romania. The study was observational, retrospective and carried out between January-June 2018. Results. The study group included 221 T2DM patients (with a mean age of 68.65 ± 10.64, ranging between 37-93 years): 116 women (52.49%; with a mean age of 70.53 ± 10.69, ranging between 37-93 years) and 105 men (47.51%; with a mean age of 66.57 ± 10.23, ranging between 38-91 years). 92 patients had AF (41.63%): 40 women (34.48%) and 52 men (49.52%). 180 patients (81.45%) were hypertensive: 103 women (88.79%) and 77 men (73.33%). 113 patients (51.13%) had metabolic syndrome: 58 women (50.00%) and 55 men (52.38%). 77 patients (34.84%) were obese: 45 women (38.79%) and 32 men (30.48%). AF patients associated obesity in 26 cases (28.26%), hypertension in 73 cases (79.35%) and metabolic syndrome in 56 cases (60.87%). Conclusions. Out of the study group, 92 T2DM patients (41.63%) had AF, men being more likely to suffer from AF than women (p=0.0288). Hypertension affected 180 patients (81.45%) and in greater proportion women vs. men (p=0.0051). The metabolic syndrome and obesity were discovered in 113 patients (51.13%) and 77 patients (34.84%), respectively, with no significant differences in terms of gender. In our research, the highest cardio metabolic risk factors for AF in T2DM were hypertension (OR = 3.6675) and the metabolic syndrome (OR = 3.3388)

Pheochromocytoma – clinical manifestations, diagnosis and current perioperative management

Pheochromocytoma is a neuroendocrine tumor characterized by the excessive production of catecholamines (epinephrine, norepinephrine, and dopamine). The diagnosis is suspected due to hypertensive paroxysms, associated with vegetative phenomena, due to the catecholaminergic hypersecretion. Diagnosis involves biochemical tests that reveal elevated levels of catecholamine metabolites (metanephrine and normetanephrine). Functional imaging, such as 123I-metaiodobenzylguanidine scintigraphy (123I-MIBG), has increased specificity in identifying the catecholamine-producing tumor and its metastases. The gold-standard treatment for patients with pheochromocytoma is represented by the surgical removal of the tumor. Before surgical resection, it is important to optimize blood pressure and intravascular volume in order to avoid negative hemodynamic events