Haptoglobin genotypic distribution in Iranian patients with coronary heart disease

Haptoglobin is a plasma protein with hemoglobin binding capacity. Haptoglobin has important biological functions such as binding to free hemoglobin and removes it from the circulation, thus preventing iron loss and kidney damage during intravascular hemolysis, superior antioxidant capacity, protection against free radicals. Studies on the distribution of Hp show that the gene frequencies of Hp dependent on geographical and genetic family. In the other, several authors have showed the correlation between HP types and different diseases, such as inflammation, infection, cardiovascular diseases and malignant tumors.Smoking, hypertention,diabetes mellitus and serum lipid concentrations are risk factors for developing cardiovascular diseases. In addition, Hp polymorphism has been proposed as a risk factor for developing atherosclerotic vasculare disease. In this study, the association between Haptoglobin genotypic distribution and the incidence of coronary heart disease investigated. 50 Iranian patients with coronary heart disease were randomly selected. Genomic DNA extracted from peripheral blood leukocytes. In PCRs with primers A and B, amplification products of 1757 and 3481 bp were amplified from genomic DNA containing alleles Hp1 and Hp2, respectively. In the population studied, the distribution of haptoglobin polymorphism was 36% (n = 18) for the Hp1-1 type, 62% (n =31) for the HP1-2 type, and 2% (n = 1) for the HP2-2 type.  The trend in this study showing a lower frequency of 3-vessel disease and less severe coronary artery stenosis in patients with the HP1-1 phenotype than in patients with the HP1-2 phenotypes may be indicative of a protective effect of the HP1-1 phenotype against the development of atherosclerotic coronary artery disease

Characterization of Flow-Induced Structures in Carbon Nanotube Suspensions

Les nanotubes de carbone sont des nanoparticules fibreuses présentes dans de nombreuses applications. Grâce à leur importante surface spécifique apparente, leur densité de courant électrique élevée, leur stabilité thermique et leurs excellentes propriétés mécaniques, les nanotubes de carbone sont utilisés pour améliorer les propriétés physiques des matrices polymériques. Les propriétés macroscopiques des suspensions proviennent de leurs propriétés à l’échelle du micron et du submicron. La structure des suspensions peut être facilement influencée par de nombreux paramètres tels que les forces de cisaillement externes, la concentration de la suspension, la température, les caractéristiques des particules, etc. L’étude de la structure de la suspension représente un défi majeur et devient un sujet d’intérêt grandissant pour de nombreux chercheurs. Dans cette étude, la structure d’une suspension modèle de nanotubes de carbone dispersée dans une résine époxy est étudiée en utilisant un ensemble de méthodes rhéologiques, les théories fractales et de mise à l’échelle ainsi qu’un modèle structural thixotropique. L’effet de l’histoire d’écoulement sur les propriétés viscoélastiques linéaires des suspensions et l’évolution de la structure lors de l’arrêt du cisaillement ont été investigués pour une large gamme de vitesse de pré-cisaillement, de concentrations et de températures. Les résultats de ces analyses sont les suivants. L’effet de l’histoire d’écoulement s’est avéré plus prononcé pour les suspensions diluées ou semi-diluées. Les faibles vitesses de pré-cisaillement entraînent un plus grand nombre d’enchevêtrements entre les particules. Cela résulte de la réduction du seuil de percolation rhéologique. Pour les suspensions diluées ou semi-diluées, après l’arrêt du cisaillement, les vi différentes structures métastables formées ont pu être distinguées par leurs différents modules de conservation qui sont inversement reliés à la vitesse de pré-cisaillement. Pour les suspensions concentrées, les structures métastables formées ont donné des modules de conservation équivalents quelque soit le pré-cisaillement appliqué. Il a été montré que la vitesse de formation de ces structures métastables augmentait avec l’augmentation de la concentration. De plus, pour les concentrations faibles et intermédiaires, la vitesse de formation des structures métastables décroît lorsque l’on augmente la vitesse de pré-cisaillement appliqué, alors que pour les concentrations élevées, le pré-cisaillement n’a pas d’influence sur la formation des structures. Il a été trouvé que le module élastique des structures métastables formées est relié aux vitesses du pré-cisaillement appliquées selon une loi de puissance; les paramètres de celle-ci dépendent fortement de la concentration. Cette corrélation est applicable aux résultats à cisaillements constants pour les suspensions formant une courbe maîtresse sur une large échelle de concentrations, au-dessus et en-dessous du point de gélification. Cela illustre également l’importance du module de conservation des structures métastables comme un paramètre représentant l’évolution de la structure. À la lumière des théories fractales et de mise à l’échelle, il apparaît dans cette recherche que les suspensions de nanotubes étudiées sont classées comme des suspensions à floculation lente pour lesquelles l’élasticité des structures provient à la fois des liaisons inter- et intra-flocs. De plus, le potentiel d’interaction des suspensions est une combinaison des composants centraux et non-centraux. La faible sensibilité de la dimension fractale des suspensions à l’histoire d’écoulement est en accord avec le module de conservation constant des structures métastables, qui est faiblement influencé par la vitesse de pré-cisaillement proche et au-dessus du point de gélification. vii Etant donné que les forces de cisaillement perturbent l’état de dispersion et d’enchevêtrement des particules, cela peut causer la formation de structures sous écoulement ou la distorsion des structures dépendant de la concentration et de la vitesse du pré-cisaillement appliquée. En comparant le module de conservation des suspensions sans pré-cisaillement et celui des structures métastables après pré-cisaillement à différentes vitesses, une vitesse de pré-cisaillement critique a été déterminée pour les concentrations faibles et intermédiaires au-dessus desquelles des enchevêtrements de nanotubes se sont rompus; cela réduit leur élasticité et provoque la formation incomplète de la structure au repos. L’évolution de la structure est en accord – qualitativement – avec les prédictions d’un modèle structural thixotropique. A la différence de nombreuses suspensions de fibres et de nano-composites, le mouvement Brownien est un mécanisme influençant la formation de la structure de la suspension de nanotubes de carbone modèle en l’absence d’écoulement. Cette conclusion a pu être formulée grâce à une analyse quantitative de la vitesse de formation de la structure selon différentes températures conjointement à la réponse de la suspension en démarrage dans des directions opposées.----------Carbon nanotubes (CNTs) are fibre-like nano-particles with many different applications. Due to their high specific surface area, high electric current density, thermal stability and excellent mechanical properties, they are used to reinforce physical properties of polymer matrices. The macroscopic properties of suspensions are inherited from their properties at micron and sub-micron scales. The suspensions structure can be easily influenced by many parameters such as the extent of external shear forces, the suspension concentration, temperature, the particles specifications, etc. This makes the study of the suspension structure a very challenging task and has been the subject of interest to many researchers. In this thesis, the structure of a model carbon nanotube suspension dispersed in an epoxy is studied by employing a set of rheological methods, scaling and fractal theories and a structural thixotropic model. The effect of flow history on linear viscoelastic properties of suspensions and the evolution of structure upon cessation of shear flow has been studied over a wide range of pre-shearing rates, concentration and temperature. The results of these analyses are as follows. The effect of flow history is more pronounced on the suspensions structure in dilute and semi-dilute concentration regimes. By pre-shearing at low rates, more inter-particle entanglements were induced, which resulted in reduction of rheological percolation thresholds. After cessation of shear flow, for dilute and semi-dilute suspensions, the formed metastable structures were distinguishable by different storage moduli, which were inversely related to the rate of pre-shearing. However, for the concentrated suspensions, the formed metastable structures had an approximately equal storage modulus regardless of the rate of the applied pre-shearing. It was shown that the rate of formation of these metastable structures was ix enhanced by increasing concentration. Furthermore, the rate of structure build-up decreased by increasing the applied pre-shear rate in low and intermediate concentrations, while it remained almost intact with respect to the pre-shearing rate at high concentrations. It was found that the elastic modulus of the formed metastable structures scaled with the applied pre-shear rate in a power-law form, the parameters of which strongly depended on the concentration. As a result, scaling the steady shear results of the suspensions using this correlation formed a master curve over a wide range of concentrations below and above the gel point; this illustrated the importance of the storage modulus of metastable structures as a parameter, which represented the parameters involved in the evolution of structure. The conducted research in the light of scaling and fractal theories revealed the fact that the model CNT suspensions under investigation was classified as slowly flocculating suspensions in which the elasticity of structures originated from both the inter- and intra-floc links. Moreover, the interaction potential of the suspensions was a combination of central and non-central components. The less sensitivity of the fractal dimension of the suspensions to the flow history was in agreement with the invariant storage modulus of the metastable structures, which was barely influenced by the rate of pre-shearing near and above the gel point. Since application of shear forces disturbed the state of dispersion and particle entanglements, it may cause formation of some flow-induced structures or distortion of structures depending on the concentration regime and the rate of the applied pre-shearing. By comparing the storage modulus of the suspensions without pre-shearing and the one for the metastable structures after pre-shearing at various rates, a critical pre-shear rate was found at low and intermediate concentrations above which some nanotube entanglements broke down; this reduced their elasticity and resulted in the incomplete structure build-up at rest during transient flow x reversal measurements. The structural evolution that has been explained so far was shown to be in qualitative agreement with the predictions of a structural thixotropic model. Unlike many fiber suspensions and nano-composites, the Brownian motion was an influential mechanism in structure build-up of the carbon nanotube model suspensions in the absence of flow. This was concluded by a quantitative analysis of the rate of the structural build-up under the variation of temperature in conjunction with the extent of structure reconstruction at rest in a set of transient stress growth measurements in opposite directions

The Evaluation of Laser Application in Surgery: A Review Article

There are several types of surgeries which use lasers in the operating room. Surgeons use lasers in general surgery or surgical specialties to cut, coagulate, and remove tissue. In modern medicine, the application of laser therapy is an attractive subject due to its minimal invasive effect. Today lasers are widely used in the treatment and diagnosis of many diseases such as various cancers, lithotripsy, ophthalmology, as well as dermatology and beauty procedures. Depending on the type of lasers, the wavelength and the delivery system, most lasers have replaced conventional surgical instruments for better wound healing results. Over time, by using many different tools and devices, new lasers have been created; as a result, they are used in a wide range of medical special cases. In this review, laser applications in surgery and its beneficial effects compared to previous surgeries with the aim of providing appropriate therapeutic and non-invasive solutions with minimal side effects after surgery are investigated

Evaluation of Laser Effects on the Human Body After Laser Therapy

Lasers have wide applications in the treatment and diagnosis of diseases and various medical fields. Laser therapy like the other methods has advantages and disadvantages. Some risks such as bleeding, pain, and infection are created after laser therapy. Explanation and evaluation of laser effects on cell function, tissue, and the body are the aims of this study. We reviewed papers available from 1986 to 2019 about the effects of lasers on cells and tissue. An online search of PubMed, Science Direct and Google scholar using such keywords as “laser”, “cell”, “tissue”, “body” and “side effects” was performed. The laser photons are absorbed by chromophores, resulting in the target heating and localized damage. Laser irradiation alters cellular metabolism and cellular functions. These alterations may be accompanied by undesired side effects which can be monitored via metabolites level change in the body. Based on this finding, laser therapy may be associated with several side effects and complications; therefore, before treatment, the determination of laser types and their properties is necessary to avoid creating side effects. The advantages and disadvantages of the treatment type should be considered in order to choose the best treatment with the least side effects. The patients’ awareness of possible side effects before treatment and also an effective follow-up and management of patients after action are two important points in laser therapy. Training curriculum definition should be determined for laser applicant qualifications in different medical fields

Effect of flow history on linear viscoelastic properties and the evolution of the structure of multiwalled carbon nanotube suspensions in an epoxy

International audienc

effect of flow history on linear viscoelastic properties and evolution of the structure of multiwelled carbon nanotube suspensions in an epoxy

International audienc

effect of flow history on linear viscoelastic properties and evolution of the structure of multiwelled carbon nanotube suspensions in an epoxy

International audienc