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1.
Molecules ; 28(2)2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36677931

RESUMO

The present paper is a narrative review focused on a few important aspects and moments of trends surrounding materials and methods in sustainable nuclear energy, as an expression of applied chemistry support for more efficiency and safety. In such context, the paper is focused firstly on increasing alloy performance by modifying compositions, and elaborating and testing novel coatings on Zr alloys and stainless steel. For future generation reactor systems, the paper proposes high entropy alloys presenting their composition selection and irradiation damage. Nowadays, when great uncertainties and complex social, environmental, and political factors influence energy type selection, any challenge in this field is based on the concept of increased security and materials performance leading to more investigations into applied science.


Assuntos
Objetivos , Energia Nuclear , Ligas/química , Aço Inoxidável/química , Entropia , Teste de Materiais
2.
Clin Lab ; 63(5): 887-899, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28627816

RESUMO

BACKGROUND: Selenium is a chemical element found in the human body that plays a crucial role in its regulation. Depending on the concentration, it may have beneficial or have toxic effects. Selenium is incorporated as selenocysteine amino acid residue in selenoproteins which play an important role in many biological functions: anti-oxidant defense, regulation of the immune function and of the inflammatory response, metabolism of thyroid hormones, functioning of the central nervous system, biosynthesis of DNA and RNA, fertility, and reproduction. Excess selenium, altough less common than selenium deficiency, has equally important negative effects. METHODS: Given the importance of selenium quantification in various samples, the study proposes a simple and direct spectrophotometric determination of selenium using triiodide anions. The method is based on the oxidation of iodide in acidic medium by selenium (IV) contained in the sample, to form elemental iodine which, in turn, reacts with the excess iodide to form the triiodide anions, the most stable soluble species in aqueous solution. Triiodide is colored from yellow to brown, depending on the concentration. The coloured compound has maximum absorbance at specific wavelengths and thus, the stage of interaction with a chromogenic agent is eliminated. Due to the sensitivity of the reaction, the detection limit of triiodide, and therefore selenium, is extended toward lower values. RESULTS: The optimal conditions for the measurements were established: λ = 290 nm, pH = 1.0 - 1.5, reaction time = 15 minutes. Two areas of selenium detection were determined from the samples: 0.025 - 0.100 ppm, and 0.1 - 4.0 ppm. The detection limit of selenium was lowered at 0.100 ppm and even at 0.025 ppm, which significantly improves the sensitivity of the determination. Types of samples were specified which are suitable for analysis using the proposed method and explained why, in case of biological fluids, it must be used only accompanied by an adequate digestion method of the samples. CONCLUSIONS: Selenium can be measured by direct spectrophotometric determination of the triiodide anion resulting from the oxidation of iodide by selenium (IV) compounds from the sample. In this regard, a simple, direct, and sensitive determination method of selenium from the samples by UV-Vis spectrophotometry, without the use of chromogenic agents has been optimized.


Assuntos
Selênio/análise , Espectrofotometria , Humanos , Iodo , Oxirredução , Água
3.
Burns Trauma ; 4: 5, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27574675

RESUMO

Nowadays, fluid resuscitation of multiple trauma patients is still a challenging therapy. Existing therapies for volume replacement in severe haemorrhagic shock can lead to adverse reactions that may be fatal for the patient. Patients presenting with multiple trauma often develop hemorrhagic shock, which triggers a series of metabolic, physiological and cellular dysfunction. These disorders combined, lead to complications that significantly decrease survival rate in this subset of patients. Volume and electrolyte resuscitation is challenging due to many factors that overlap. Poor management can lead to post-resuscitation systemic inflammation causing multiple organ failure and ultimately death. In literature, there is no exact formula for this purpose, and opinions are divided. This paper presents a review of modern techniques and current studies regarding the management of fluid resuscitation in trauma patients with hemorrhagic shock. According to the literature and from clinical experience, all aspects regarding post-resuscitation period need to be considered. Also, for every case in particular, emergency therapy management needs to be rigorously respected considering all physiological, biochemical and biological parameters.

4.
Clin Lab ; 62(6): 977-86, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27468558

RESUMO

BACKGROUND: The complexity of the cases of critically ill polytrauma patients is given by both the primary, as well as the secondary, post-traumatic injuries. The severe injuries of organ systems, the major biochemical and physiological disequilibrium, and the molecular chaos lead to a high rate of morbidity and mortality in this type of patient. The 'gold goal' in the intensive therapy of such patients resides in the continuous evaluation and monitoring of their clinical status. Moreover, optimizing the therapy based on the expression of certain biomarkers with high specificity and sensitivity is extremely important because of the clinical course of the critically ill polytrauma patient. In this paper we wish to summarize the recent studies of biomarkers useful for the intensive care unit (ICU) physician. METHODS: For this study the available literature on specific databases such as PubMed and Scopus was thoroughly analyzed. Each article was carefully reviewed and useful information for this study extracted. The keywords used to select the relevant articles were "sepsis biomarker", "traumatic brain injury biomarker" "spinal cord injury biomarker", "inflammation biomarker", "microRNAs biomarker", "trauma biomarker", and "critically ill patients". RESULTS: For this study to be carried out 556 original type articles were analyzed, as well as case reports and reviews. For this review, 89 articles with relevant topics for the present paper were selected. The critically ill polytrauma patient, because of the clinical complexity the case presents with, needs a series of evaluations and specific monitoring. Recent studies show a series of either tissue-specific or circulating biomarkers that are useful in the clinical status evaluation of these patients. CONCLUSIONS: The biomarkers existing today, with regard to the critically ill polytrauma patient, can bring a significant contribution to increasing the survival rate, by adapting the therapy according to their expressions. Nevertheless, the necessity remains to research new non-invasive diagnostic methods that present with higher specificity and selectivity.


Assuntos
Biomarcadores/metabolismo , Técnicas de Apoio para a Decisão , Marcadores Genéticos , Traumatismo Múltiplo/diagnóstico , Estado Terminal , Humanos , Mediadores da Inflamação/metabolismo , MicroRNAs/genética , Traumatismo Múltiplo/genética , Traumatismo Múltiplo/metabolismo , Traumatismo Múltiplo/mortalidade , Traumatismo Múltiplo/terapia , Estresse Oxidativo , Valor Preditivo dos Testes , Prognóstico , Fatores de Risco
5.
Clin Lab ; 62(3): 263-74, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27156313

RESUMO

BACKGROUND: The diversity of primary and secondary traumatic injuries specific for the critically ill polytrauma patient is complicating the therapeutic management in the absence of a strict assessment of the biological changes. Inflammation, redox imbalance, and immunosuppression can be quantified by various biochemical parameters; however, they do not fully respond to the current requirements. Another phenomenon responsible for worsening the clinical status and for the development of complications in such patients is oxidative stress. Its aggressiveness combined with biochemical and physiological imbalances leads to increased morbidity and mortality. To minimize the effects induced by free radicals, various substances are administered with high antioxidant capacity. However, the dosage optimization for each patient is difficult without strict monitoring of oxidative stress. In this paper we will summarize and present the pathophysiology of oxidative stress, as well as the specificity of miRNAs for a series of molecular changes at the cellular level. METHODS: For this study the available literature on specific databases such as PubMed, Embase and Scopus was thoroughly analyzed. Each article has been carefully reviewed, extracting useful information for this study. The keywords used to select the relevant articles were "oxidative stress", "antioxidant therapy", "microRNAs biomarkers", and "critically ill patients". RESULTS: For this study, 121 scientific articles relevant to our topic were analyzed. Currently, quantification of oxidative stress is achieved through indirect correlations with plasma levels of specific biomarkers. For a more specific evaluation of the redox status, numerous studies were conducted on the use of circulating miRNAs as biomarkers in this regard. CONCLUSIONS: Introducing miRNAs can revolutionize both monitoring and therapy modulation in these patients, adapting to the organic damage.


Assuntos
Estado Terminal , MicroRNAs/sangue , Traumatismo Múltiplo/metabolismo , Estresse Oxidativo , Biomarcadores/sangue , Humanos
6.
Mol Biol Int ; 2015: 238586, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26693352

RESUMO

The critically ill polytrauma patient is a constant challenge for the trauma team due to the complexity of the complications presented. Intense inflammatory response and infections, as well as multiple organ dysfunctions, significantly increase the rate of morbidity and mortality in these patients. Moreover, due to the physiological and biochemical imbalances present in this type of patients, the bioproduction of free radicals is significantly accelerated, thus installing the oxidative stress. In the therapeutic management of such patients, multiple surgical interventions are required and therefore they are being subjected to repeated general anesthesia. In this paper, we want to present the pathophysiological implications of oxidative stress in critically ill patients with multiple traumas and the implications of general anesthesia on the redox mechanisms of the cell. We also want to summarize the antioxidant treatments able to reduce the intensity of oxidative stress by modulating the biochemical activity of some cellular mechanisms.

7.
Anal Cell Pathol (Amst) ; 2015: 186716, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26221578

RESUMO

Sepsis is one of the most common causes of death in critical patients. Severe generalized inflammation, infections, and severe physiological imbalances significantly decrease the survival rate with more than 50%. Moreover, monitoring, evaluation, and therapy management often become extremely difficult for the clinician in this type of patients. Current methods of diagnosing sepsis vary based especially on the determination of biochemical-humoral markers, such as cytokines, components of the complement, and proinflammatory and anti-inflammatory compounds. Recent studies highlight the use of new biomarkers for sepsis, namely, miRNAs. miRNAs belong to a class of small, noncoding RNAs with an approximate content of 19-23 nucleotides. Following biochemical and physiological imbalances, the expression of miRNAs in blood or other body fluids changes significantly. Moreover, its stability, specificity, and selectivity make miRNAs ideal candidates for sepsis biomarkers. In conclusion, we can affirm that stable species of circulating miRNAs represent potential biomarkers for monitoring the evolution of sepsis.


Assuntos
Biomarcadores/metabolismo , MicroRNAs/metabolismo , Sepse/genética , Animais , Biomarcadores/sangue , Líquidos Corporais/metabolismo , Regulação da Expressão Gênica , Humanos , MicroRNAs/sangue , MicroRNAs/química , MicroRNAs/genética , Sepse/diagnóstico
8.
Rom J Anaesth Intensive Care ; 22(2): 89-96, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28913463

RESUMO

INTRODUCTION: The biochemical processes of bioproduction of free radicals (FR) are significantly increasing in polytrauma patients. Decreased plasma concentrations of antioxidants, correlated with a disturbance of the redox balance are responsible for the installation of the phenomenon called oxidative stress (OS). OS action is associated with a series of secondary complications with direct implications in reducing the rate of survival, as well as in increasing morbidity The objectives of this study were to reveal possible relations between antioxidant therapy and a number of serum biochemical variables (ALT, AST, APPT, LDH, urea, leukocytes, platelets), the length of mechanical ventilation, the time spent in the ICU, and the mortality rate in major trauma patients. MATERIALS AND METHODS: In this retrospective study from a single center, 64 medical files of polytrauma patients admitted to the ICU "Casa Austria" were analysed. The selection criteria were: the Injury Severity Score (ISS) > 16 and a systolic arterial pressure (SAP) < 89 mmHg. The selected patients (n = 34) were divided into two groups: Antiox group, 20 patients who benefited from antioxidant therapy and the Contr group, 14 patients who did not received antioxidant therapy and served as a control group. The antioxidant therapy consisted of the simultaneous administration of vitamin C (i.v.), vitamin B1 (i.v.) and N-acetylcysteine (i.v.). The clinical and the biological evaluation were performed repeatedly until discharge from the ICU or the death of the patient. RESULTS: No significant differences were highlighted concerning the demographic data, the magnitude or the trauma mechanism between the two groups. In comparison with patients from the Contr group, the patients submitted to antioxidant therapy showed lower values after the treatment for leukocytes (p = 0.0066), urea (p = 0.0076), LDH (p = 0.0238), AST (p = 0.0070) and ALT (p < 0.0001). No statistically significant differences were evidenced regarding the incidence of sepsis or the development of multiple organ dysfunction syndrome (MODS). The period of mechanical ventilation was longer in patients from the Contr group (p = 0.0498), with no differences concerning the ICU length of stay (p = 0.7313). The mortality rate was lower in the Contr group (p = 0.0475). CONCLUSION: In multiple trauma patients a prolonged antioxidant therapy improved the posttraumatic laboratory tests.

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