Gabriel Predoi

Electrochemical Methods for Total AntioxidantCapacity and its Main Contributors Determination:A review

Abstract Backround: The present review focuses on electrochemical methods for antioxidant capacity and its main contributors assessment. The main reactive oxygen species, responsible for low density lipoprotein oxidation, and their reactivity are reminded. The role of antioxidants in counteracting the factors leading to oxidative stress-related degenerative diseases occurence, is then discussed. Antioxidants can scavenge free radicals, can chelate pro-oxidative metal ions, or quench singlet oxygen. When endogenous factors (uric acid, bilirubin, albumin, metallothioneins, superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase) cannot accomplish their protective role against reactive oxygen species, the intervention of exogenous antioxidants (vitamin C, tocopherols, flavonoids, carotenoids etc) is required, as intake from food, as nutritional supplements or as pharmaceutical products. Literature study: The main advantages of electrochemical methods with respect to traditional, more laborious instrumental techniques are described: sensitivity, rapidity, simplicity of the applied analytical procedure which does not require complicated sample pre-treatment etc. The paper reviews minutiously the voltammetric, amperometric, biamperometric, potentiometric and coulometric methods for total antioxidant capacity estimation. For each method presented, the electroactivity and the mechanism of electro-oxidation of antioxidant molecules at various electrodes, as well as the influences on the electroactive properties are discussed. The characteristics of the developed methods are viewed from the perspective of the antioxidant molecule structure influence, as well as from the importance of electrode material and/or surface groups standpoint. The antioxidant molecule-electrode surface interaction, the detection system chosen, the use of modifiers, as well as the nature of the analysed matrix are the factors discussed, which influence the performances of the studied electrochemical techniques. Conclusions: The electrochemical methods reviewed in this paper allow the successful determination of the total antioxidant capacity and of its main contributors in various media: foodstuffs and beverages, biological fluids, pharmaceuticals. The advantages and disadvantages of the electrochemical methods applied to antioxidant content and antioxidant activity assay are treated and interpreted, in the case of various analysed matrixes. Combining advanced materials with classical electrode construction, provides viable results and can constitute an alternative for the future. Graphical Abstract

Antioxidant Capacity Determination in Plants and Plant-Derived Products: A Review

The present paper aims at reviewing and commenting on the analytical methods applied to antioxidant and antioxidant capacity assessment in plant-derived products. Aspects related to oxidative stress, reactive oxidative species influence on key biomolecules, and antioxidant benefits and modalities of action are discussed. Also, the oxidant-antioxidant balance is critically discussed. The conventional and nonconventional extraction procedures applied prior to analysis are also presented, as the extraction step is of pivotal importance for isolation and concentration of the compound(s) of interest before analysis. Then, the chromatographic, spectrometric, and electrochemical methods for antioxidant and antioxidant capacity determination in plant-derived products are detailed with respect to their principles, characteristics, and specific applications. Peculiarities related to the matrix characteristics and other factors influencing the methods performances are discussed. Health benefits of plants and derived products are described, as indicated in the original source. Finally, critical and conclusive aspects are given when it comes to the choice of a particular extraction procedure and detection method, which should consider the nature of the sample, prevalent antioxidant/antioxidant class, and the mechanism underlying each technique. Advantages and disadvantages are discussed for each method.

MRI Findings in Choroid Plexus Carcinoma in Two Dogs

Abstract Due to technological advances in bio-imaging in the last years, magnetic resonance imaging (MRI) is widely used as a noninvasive and non-irradiant tool for assessment and imaging diagnosis. In this study are presented two dogs with progressive clinical and neurological manifestations, following the discovered signs (head tilt and circling in the first case, respective epileptic seizures and ataxia in the second case), MRI evaluation was recommended. The imaging exams showed the presence of a mass, located in the third ventricle, with heterogeneous signal changes in conventional sequences T1, T2 and FLAIR. Unifying the imaging data with those of the histopathological examination it was possible to establish the diagnosis of choroid plexus carcinoma in both cases.

Properties of Basil and Lavender Essential Oils Adsorbed on the Surface of Hydroxyapatite

The research conducted in this study presented for the first time results of physico-chemical properties and in vitro antimicrobial activity of hydroxyapatite plant essential oil against Gram-positive bacteria (methicillin-resistant Staphylococcus aureus (MRSA) and S. aureus 0364) and Gram-negative bacteria (Escherichia coli ATCC 25922). The samples were studied by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy to determine the morphology and structure of the nanocomposites of hydroxyapatite coated with basil (HAp-B) and lavender (HAp-L) essential oils (EOs). The values of the BET specific surface area (SBET), total pore volume (VP) and pore size (DP) were determined. The results for the physico-chemical properties of HAp-L and HAp-B revealed that lavender EOs were well adsorbed on the surface of hydroxyapatite, whereas basil EOs showed a poor adsorption on the surface of hydroxyapatite. We found that the lavender EOs hydroxyapatite (HAp-L) exhibited a very good inhibitory growth activity. The value of the minimum inhibitory concentration (MIC) related to growth bacteria was 0.039 mg/mL for MRSA, 0.02 mg/mL for S. aureus and 0.039 mg/mL E. coli ATCC 25922. The basil EO hydroxyapatite (HAp-B) showed poor inhibition of bacterial cell growth. The MIC value was 0.625 mg/mL for the HAp-B sample in the presence of the MRSA bacteria, 0.313 mg/mL in the presence of S. aureus and 0.078 mg/mL for E. coli ATCC 25922.

Nanoencapsulation techniques for compounds and products with antioxidant and antimicrobial activity - A critical view

Oxidative decay and microbial spoilage are issues of concern, as they constitute threats to human health. Natural antioxidants and antimicrobials hamper the negative impact of synthetic compounds and they need appropriate delivery systems. Different nanostructures can be developed: association colloids-based nanostructures, nanoemulsions, nanoliposomes, nanolaminates, nanofibers, carbon nanotubes, nanocomposites. The main nanoencapsulation techniques applied to antioxidants and antimicrobials are described: association colloid-based nanoincorporation, lipid-based nanoencapsulation techniques, encapsulation techniques based on biologically-derived polymeric nanocarriers, encapsulation techniques based on non-biological polymeric nanocarriers, cyclodextrin incorporation, electrospraying and electrospinning, carbon nanotubes and nanocomposite encapsulation. Several nanoencapsulation methods can be followed by freeze-drying or spray-drying. Protection of bioactive compounds and controlled release are achieved, but the impact of the nanomaterials on human health and on the environment should be considered. The influence of the nanoencapsulation techniques on the antioxidant/antimicrobial activity is discussed. The choice of the appropriate encapsulation method is vital. Bioactivity increase, preservation or decrease, depend on the interactions established between the functional groups of encapsulated compound and the encapsulating nanomaterial.

Insights into the Animal’s Mind

Although it was believed that the mind is an “exclusive ability” of human beings, many animals possess excellent perceptual and cognitive skills that sometimes surpass those of humans. For example, sensory abilities such as sight, hearing, and smell are much better developed in some animals than in humans. Also some animals are capable of using tools, to live in a hierarchical society, and to develop empathy towards animals of different species (Striedter 2013). Here, we discuss cognitive features in animals with small brain, as well as, in animals with larger brains. To understand animal’s mind, this chapter examines the animal’s brain from structural (anatomy: brain size, connectome and modularity, i.e. lamination and minicolumns) and functional (learning, cognition, and mind) perspectives.

Aspects Concerning the Morphology and Topography of the Lymph nodes in Pelvic Limb in Swine

The lymphatic system consists of lymph nodes, lymphatic vessels and lymph. In this current clinical examination, only lymph nodes are examined. The lymphatic vessels are examined only in pathological cases and the lymph is not a normal subject for an examination (the harvesting is very difficult). Inxa0swine , the examination of lymph nodes is difficult (sometimes possible xad only for weak pigs) because of the subcutaneous fat. The most important figures are offered, in this situation, by the lymph nodes examination in necropsy exam or from the animal after slaughtering it. The studies accomplished in this work have the purpose to offer, to whom it may concern, useful information about the morphology and the topography of muscular lymph nodes for the pelvic limb in swine, taking into account the fact that for the veterinary control of the meat we have to include the veterinary examination, before slaughter. The study material was represented by pieces that came from 4 swine individuals with an average weight of 40kg. The most used method was dissection, executed bilaterally and in successive plans to the limit of visibility, using the Nikon SMZ 2T stereomicroscope, that the Domestic Animal Anatomy Laboratory is equipped with. There were identified the relations between the lymph nodes and the blood vessels and were taken notes about individual variations. The lymph nodes of the pelvic limb in swine are consistently represented by: iliofemoral, scrotal or mammary, sub iliac, ischial, gluteus and superficial popliteal. Besides the fact that, generally, the accessory lymph nodes are missing, yet they are found in 50% of cases into the deep popliteal lymph node, located in the gap between gluteus biceps and semitendinosus, embedded into the fat tissue.

Comparative aspects regarding the thoracic limb musclesin domestic pig and wild boar.

In various specialized works, the aspects concerning the muscles morphology in swine aren’t very detailed. This is due to the fact that the frequence of terapeutical interventions and in the first place, the surgical interventions in this segment and at this specie is not very high. Still, in the last years the comparative medicine has continued to enhance new experimental models on swine and the interest for knowing the anatomy and physiology of this animal has increased. Our comparative study has emphasized some morphological differences between the two species unreported in specialized literature, that showed especially the strengthening of the stay apparatus in boar. We can highlight the development of the tendons that flank the scapular humeral joint and the shaping of a bicipital tendon brace at that specie.