Phytochemical study: molecular docking of eugenol derivatives as antioxidant and antimicrobial agents

Abstract:

Eugenol (4-allyl-2-methoxyphenol) is a natural phenolic compound present in certain aromatic plants; however, it is generally extracted from essential oil of Eugenia caryophyllata (Syzygiumaromaticum) (L.) Merr. and L.M. Perry. This bioactive natural compound has generated considerable biological interest with well-known antimicrobial and antioxidant actions. The authors have aimed to the evaluations of eugenol derivatives and their as antimicrobial and antioxidant agent with the aid of molecular dynamic simulation. The starting material was extracted from cloves using hydrodistillation. Two eugenol derivatives, acetyleugenol (4-allyl-2-methoxyphenylacetate) and epoxyeugenol (4-allyl-2-methoxyphenol) were prepared and tested against two strains Escherichia coli (E. Coli) and Staphylococcus aureus (S. Aureus). The results have revealed that the three compounds (Eugenol, acetyleugenol and epoxyeugenol) possess important potentials of inhibition against E. coli and S. Aureus. The antioxidant activity of eugenol derivatives was evaluated by the reaction with DPPH (1,1-diphenyl-2-picrylhydrazyl), showed that the epoxyeugenol was the most active compound. The molecular docking scores of three compounds and the amino acids in the active site pockets of the selected proteins of the two bacteria have approved and explain the biological experimental outcomes.

In-vacuum Faraday isolation remote tuning

In-vacuum Faraday isolators (FIs) are used in gravitational wave interferometers to prevent the disturbance caused by light reflected back to the input port from the interferometer itself. The efficiency of the optical isolation is becoming more critical with the increase of laser input power. An in-vacuum FI, used in a gravitational wave experiment (Virgo), has a 20 mm clear aperture and is illuminated by an almost 20 W incoming beam, having a diameter of about 5 mm. When going in vacuum at 10(-6) mbar, a degradation of the isolation exceeding 10 dB was observed. A remotely controlled system using a motorized lambda=2 waveplate inserted between the first polarizer and the Faraday rotator has proven its capability to restore the optical isolation to a value close to the one set up in air.

Nonlinear sensors: an approach to the residence time detection strategy

The monitoring of the residence time difference in bistable sensors has been recently proposed as a valid scheme for improving the detection capabilities of sensors as diverse as fluxgate magnetometers, ferroelectric sensors and mechanical sensors. In this paper we propose an approach to the residence time based detection strategy based on the measurement of the slope m of the sensor output integral. We demonstrate that such a method, far from degrading the detection performances can provide an easier way to realize fast and reliable sensors without the computationally demanding task related with the computation of the residence time difference. We introduce the receiver operating characteristic curve as a quantitative estimator for the comparison of the two methods and show that the detector performances increase with increasing the periodic bias amplitude A up to a maximum value. This condition has potentially relevant consequences in the future detectors design.

In-vacuum optical isolation changes by heating in a Faraday isolator

We describe a model evaluating changes in the optical isolation of a Faraday isolator when passing from air to vacuum in terms of different thermal effects in the crystal. The changes are particularly significant in the crystal thermal lensing (refraction index and thermal expansion) and in its Verdet constant and can be ascribed to the less efficient convection cooling of the magneto-optic crystal of the Faraday isolator. An isolation decrease by a factor of 10 is experimentally observed in a Faraday isolator that is used in a gravitational wave experiment (Virgo) with a 10 W input laser when going from air to vacuum. A finite element model simulation reproduces with a great accuracy the experimental data measured on Virgo and on a test bench. A first set of measurements of the thermal lensing has been used to characterize the losses of the crystal, which depend on the sample. The isolation factor measured on Virgo confirms the simulation model and the absorption losses of 0.0016 +/- 0.0002/cm for the TGG magneto-optic crystal used in the Faraday isolator.

[Psychological dynamics in adolescence regarding death and suicide]

The authors try to analyse the idea of death and suicide in the adolescent and in order to face the psychological dynamics underlying these experiences. Therefore the differences between adolescential vitality and the separation-loss feelings emerge, between the need for autonomy and the search for identification patterns that are peculiar to this part of vital cycle. The autonomy and freedom search seems to pass delusively through the manipulation of the idea of death, to face a theme reserved to adults gives adolescent omnipotence feelings, assuring him at the same time against anguish. In the second part the authors report the clinical case of a boy who attempted suicide turce and who is under observation in the Department of Mental Health.

[Dream and initial phases of analysis: history, diagnosis, prognosis, and therapeutic remarks]

The authors underline the importance of dreams in the initial phases of psychoanalysis as an instrument of diagnosis and prognosis. In these first phases of explorative analysis or of consultation the dreams will show the structures and the deep mental dynamics of the patient, they will also show the expectations that the patient has with regard to the therapeutic prospects, and also the effectiveness of the encounter between patient and therapist. The authors underline the significance of the moment in which the dreams are told to the analyst: it is possible, therefore, to speak about anamnestic dreams, about dreams that are a consequence of the decision to start an analysis, about dreams that referred to the first contact between the patient and the analyst, about dreams that concern the consultation phase broadly. The authors, moreover, describe several examples of patients' dreams in the first phases of explorative analysis and they supply them with an interpretation and with a diagnostic and prognostic use, and they also propose indications on how and in what way and if it is the case to continue the therapy.