226 research outputs found

    Pheochromocytoma – clinical manifestations, diagnosis and current perioperative management

    Get PDF
    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

    On the feasibility of N2 fixation via a single-site FeI/FeIV cycle: Spectroscopic studies of FeI(N2)FeI, FeIV=N, and related species

    Get PDF
    The electronic properties of an unusually redox-rich iron system, [PhBPR 3]FeNx (where [PhBPR 3] is [PhB(CH2PR2)3]−), are explored by Mössbauer, EPR, magnetization, and density-functional methods to gain a detailed picture regarding their oxidation states and electronic structures. The complexes of primary interest in this article are the two terminal iron(IV) nitride species, [PhBPiPr 3]FeN (3a) and [PhBPCH2Cy 3]FeN (3b), and the formally diiron(I) bridged-Fe(μ-N2)Fe species, {[PhBPiPr 3]Fe}2(μ-N2) (4). Complex 4 is chemically related to 3a via a spontaneous nitride coupling reaction. The diamagnetic iron(IV) nitrides 3a and 3b exhibit unique electronic environments that are reflected in their unusual Mössbauer parameters, including quadrupole-splitting values of 6.01(1) mm/s and isomer shift values of −0.34(1) mm/s. The data for 4 suggest that this complex can be described by a weak ferromagnetic interaction (J/D < 1) between two iron(I) centers. For comparison, four other relevant complexes also are characterized: a diamagnetic iron(IV) trihydride [PhBPiPr 3]Fe(H)3(PMe3) (5), an S = 3/2 iron(I) phosphine adduct [PhBPiPr 3]FePMe3 (6), and the S = 2 iron(II) precursors to 3a, [PhBPiPr 3]FeCl and [PhBPiPr 3]Fe-2,3:5,6-dibenzo-7-aza bicyclo[2.2.1]hepta-2,5-diene (dbabh). The electronic properties of these respective complexes also have been explored by density-functional methods to help corroborate our spectral assignments and to probe their electronic structures further

    Dynamics of ripple formation on silicon surfaces by ultrashort laser pulses in sub-ablation conditions

    Full text link
    An investigation of ultrashort pulsed laser induced surface modification due to conditions that result in a superheated melted liquid layer and material evaporation are considered. To describe the surface modification occurring after cooling and resolidification of the melted layer and understand the underlying physical fundamental mechanisms, a unified model is presented to account for crater and subwavelength ripple formation based on a synergy of electron excitation and capillary waves solidification. The proposed theoretical framework aims to address the laser-material interaction in sub-ablation conditions and thus minimal mass removal in combination with a hydrodynamics-based scenario of the crater creation and ripple formation following surface irradiation with single and multiple pulses, respectively. The development of the periodic structures is attributed to the interference of the incident wave with a surface plasmon wave. Details of the surface morphology attained are elaborated as a function of the imposed conditions and results are tested against experimental data

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

    Get PDF
    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)

    Current pharmacological treatment of painful diabetic neuropathy: A narrative review

    Get PDF
    Background and Objectives: Distal symmetrical polyneuropathy (DSPN) is one of the most common chronic complications of diabetes mellitus. Although it is usually characterized by progressive sensory loss, some patients may develop chronic pain. Assessment of DSPN is not difficult, but the biggest challenge is making the correct diagnosis and choosing the right treatment. The treatment of DSPN has three primary objectives: glycemic control, pathogenic mechanisms, and pain management. The aim of this brief narrative review is to summarize the current pharmacological treatment of painful DSPN. It also summarizes knowledge on pathogenesis-oriented therapy, which is generally overlooked in many publications and guidelines. Materials and Methods: The present review reports the relevant information available on DSPN treatment. The search was performed on PubMed, Cochrane, Semantic Scholar, Medline, Scopus, and Cochrane Library databases, including among others the terms “distal symmetrical polyneuropathy”, “neuropathic pain treatment”, “diabetic neuropathy”, “diabetes complications”, ”glycaemic control”, “antidepressants”, “opioids”, and “anticonvulsants”. Results: First-line drugs include antidepressants (selective serotonin reuptake inhibitors and tricyclic antidepressants) and pregabalin. Second- and third-line drugs include opioids and topical analgesics. While potentially effective in the treatment of neuropathic pain, opioids are not considered to be the first choice because of adverse reactions and addiction concerns. Conclusions: DSPN is a common complication in patients with diabetes, and severely affects the quality of life of these patients. Although multiple therapies are available, the guidelines and recommendations regarding the treatment of diabetic neuropathy have failed to offer a unitary consensus, which often hinders the therapeutic options in clinical practice

    Pheochromocytoma – clinical manifestations, diagnosis and current perioperative management

    Get PDF
    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

    Incisional hernias – results of present therapy options

    Get PDF
    Sp. Sf. Pantelimon, București, Al XI-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova și cea de-a XXXIII-a Reuniune a Chirurgilor din Moldova „Iacomi-Răzeșu” 27-30 septembrie 2011Introducere: Hernia incizională este cea mai frecventă complicație după operațiile abdominale. Este dificil de estimat exact costul acestei patologii pentru societate. Dacă adăugam la costul intervenției chirurgicale și costul spitalizării, dificultățile operațiilor de recidivă multiplă, costul protezelor, morbiditățile pacienților neoperați, afectarea capacității de muncă și a calității vieții, vom avea magnitudinea problemei dezvoltate de această complicație redutabilă a tuturor intervențiilor chirurgicale. Material și metodă: Am analizat rezultatele mai multor studii de prestigiu ale unor colective românești și internaționale în domeniul herniilor incizionale. Rezultate: Din nefericire rezultatele globale ale tratamentului în hernia incizională oscilează între 12-63% pentru procedeele tisulare și între 2-36% pentru procedeele allopalstice. Abordul chirurgical este cel mai adesea bazat pe traditie si pe liberul arbitru, decat pe evidențe statistice sau ghiduri de tratament. Nu este deloc surprinzător faptul că, în ciuda noilor cuceriri în domeniul defectelor parietale și a folosirii explozive a protezelor, rata de re-operații pentru recidiva incizională se situează la același nivel. Concluzii: Componența operatorie ca unică etiologie în hernia incizională este supraestimată. Datorită faptului că și alți factori etiologici, cunoscuți sau nu, concura la apariția herniei incizionale și la re-recidivă, și datorită faptului că acești “factori” nu sunt deocamdată influențabili de tratamentul medical nu ne rămțne decât să analizăm lucid și responsabil factorii chirurg-dependenți. Greselile de tactică/tehnică chirurgicală trebuie evidențiate, explicate, și înlăturate. Soluția nu este o abordare pur tehnică, ci una fiziologică, în termeni de elasticitate, complianța și rezistența a întregului perete abdominal, deseori modificat profund de marile defecte incizionale.Introduction: incisional hernia is the most common complication after abdominal surgery. It is difficult to estimate the exact cost to society of this pathology. If we add to the cost of surgery and hospitalization costs, the difficulties of relapse multiple operations, the cost of prostheses, unoperated patient morbidity, impaired work capacity and quality of life, the magnitude of the problem we have developed this redoubtable complication of all surgical procedures. Methods: We analyzed the results of several studies of prestigious romanian and international collectives about incisional hernias. Results: Unfortunately, the overall results of treatment in incisional hernia procedures vary between 12-63% for tissular procedures and between 2-36% for allopalstic procedures. Surgical approach is most often based on tradition and the free will, rather than obvious statistical treatment guidelines. Not surprisingly, despite the new advancements in the field of herniology and the use of new parietal prosthesis, the rate of re-operations for recurrent incisional fall at the same level. Conclusions: Surgery as the only component in etiology of incisional hernias is overestimated. Due to the fact that other etiological factors, known or not compete in the emergence and re-incision hernia recurrence, and because these “factors” are not influenced by medical treatment for now, we are just lucid and analyze the factors responsible - surgeon dependent. Mistakes tactics/surgical technique must be highlighted, explained and removed. The solution is not a purely technical approach, but a physiological, in terms of elasticity, compliance and resistance of the entire abdominal wall

    Correlations between Diabetes Mellitus Self-Care Activities and Glycaemic Control in the Adult Population: A Cross-Sectional Study

    Get PDF
    Although it is well known that lifestyle changes can affect plasma glucose levels, there is little formal evidence for the sustained effectiveness of exercise and diet in diabetes mellitus (DM) management. Self-care in DM refers to the real-life application of the knowledge that the patient gained during the education programmes. The goals are to bring about changes in the patient’s behaviour, thus improving glycaemic control. We evaluated the influence of DM self-care activities (SCA) on glycaemic control in a total of 159 patients with DM. Plasma glycated haemoglobin (HbA1c) levels were used to monitor glycaemic control, while SCA were assessed using the standardised Diabetes Self-Management Questionnaire (DSMQ). In our study, 53% of the patients had a HbA1c ≥ 7%. In univariate linear regression models, a statistically significant inverse association was observed between the HbA1c (the dependent variable) and both the DSMQ Dietary Control Score (R2 = 0.037, p = 0.0145) and the DSMQ Sum Score (R2 = 0.06, p = 0.0014). The mean absolute change in the HbA1c% associated with one standard deviation (SD) change in the DSMQ Sum Score, independent of the other significant variables retained in the compacted multivariate regression model, was −0.419% (confidence interval: 95%: from −0.18 to −0.65). Although the impact of the DSMQ Score was modest when compared to the other independent variables in the multivariate model, the findings emphasise the importance of maintaining optimal lifestyle changes to avoid hyperglycaemia and its complications. In conclusion, enhanced self-management of DM is associated with improved glucose control. In patients with chronic diseases such as DM, the role of streamlining SCA encompassing physical activity and proper dietary choices is imperative because of a significantly reduced access to healthcare globally as a result of the COVID-19 pandemic

    Invited Article: Filamentary deposition of laser energy in glasses with Bessel beams

    Get PDF
    We investigate the nonlinear absorption of laser energy in the bulk of transparent dielectrics for femtosecond and picosecond laser pulses focused by a conical lens. We highlight the influence of the pulse duration, laser pulse energy, and cone angle on laser energy absorption in transparent dielectrics. We provide a semi-analytical model allowing the calculation of maps for the density of nonlinear absorption of energy in BK7 and in SiO2 as a function of the pulse duration and peak fluence in the focal region. The comparison of the density of nonlinear absorption of energy with the available energy density determines optimal pulse durations and Bessel beam cone angles compatible with uniform laser energy deposition in the Bessel zone. The results reproduce quantitatively the transmission measurements for experiments in BK7 with picosecond pulses and suggest that the loss of propagation invariance and uniform laser energy deposition is responsible for a previously reported transition between different types of damage morphology in SiO2 [M. K. Bhuyan et al., Appl. Phys. Lett. 104, 021107 (2014)].We investigate the nonlinear absorption of laser energy in the bulk of transparent dielectrics for femtosecond and picosecond laser pulses focused by a conical lens. We highlight the influence of the pulse duration, laser pulse energy, and cone angle on laser energy absorption in transparent dielectrics. We provide a semi-analytical model allowing the calculation of maps for the density of nonlinear absorption of energy in BK7 and in SiO2 as a function of the pulse duration and peak fluence in the focal region. The comparison of the density of nonlinear absorption of energy with the available energy density determines optimal pulse durations and Bessel beam cone angles compatible with uniform laser energy deposition in the Bessel zone. The results reproduce quantitatively the transmission measurements for experiments in BK7 with picosecond pulses and suggest that the loss of propagation invariance and uniform laser energy deposition is responsible for a previously reported transition between different typ..
    corecore