Assessment of Fennel Oil Microfluidized Nanoemulsions Stabilization by Advanced Performance Xanthan Gum

In this work, nanoemulsion-based delivery system was developed by encapsulation of fennel essential oil. A response surface methodology was used to study the influence of the processing conditions in order to obtain monomodal nanoemulsions of fennel essential oil using the microchannel homogenization technique. Results showed that it was possible to obtain nanoemulsions with very narrow monomodal distributions that were homogeneous over the whole observation period (three months) when the appropriate mechanical energy was supplied by microfluidization at 14 MPa and 12 passes. Once the optimal processing condition was established, nanoemulsions were formulated with advanced performance xanthan gum, which was used as both viscosity modifier and emulsion stabilizer. As a result, more desirable results with enhanced physical stability and rheological properties were obtained. From the study of mechanical spectra as a function of aging time, the stability of the nanoemulsions weak gels was confirmed. The mechanical spectra as a function of hydrocolloid concentration revealed that the rheological properties are marked by the biopolymer network and could be modulated depending on the amount of added gum. Therefore, this research supports the role of advanced performance xanthan gum as a stabilizer of microfluidized fennel oil-in-water nanoemulsions. In addition, the results of this research could be useful to design and formulate functional oil-in-water nanoemulsions with potential application in the food industry for the delivery of nutraceuticals and antimicrobials.

A fixed point algorithm for extracting the atrial activity in the frequency domain

In this work we present a fixed point algorithm to extract the atrial rhythm in atrial tachyarrhythmias from the surface electrocardiogram (ECG). In the frequency domain the atrial signal is characterized by a concentration of power around a main peak in the bandwidth 3-10Hz. The proposed algorithm exploits this discriminative property of the atrial component in combination with the decoupling of the atrial and other components superposed in the ECG. It recovers only the interesting atrial rhythm in a simple, fast and reliable way using the information contained in all the leads and reducing the average computational time from 0.902s (FastICA) to 0.023s (the proposed method). The algorithm is applied successfully to synthetic and real data. In simulated ECGs, the correlation index obtained was 0.792. In real ECGs, the accuracy of the results was validated using spectral and temporal parameters. The average peak frequency and spectral concentration obtained were 5.354Hz and 59.4%, respectively, and the kurtosis was 0.065.

Constrained temporal extraction of the atrial rhythm in Atrial Fibrillation episodes

The extraction of the Atrial Activity from the Ventricular Activity in Atrial Fibrillation episodes is a must for clinical analysis. We follow the semi Blind Source Extraction S-BSE approach to solve the problem. The proposed algorithm modifies the BSE contrast function to satisfy the prior knowledge about the spectral content of the atrial signal. The introduction of this prior allows obtaining a new algorithm with the following advantages: it allows the extraction of only the atrial component and it improves the quality of the recovered atrial signal in terms of spectral concentration as we show in the results.

[Prevalence of chronic hidden infections in a cohort of patients in substitutive treatment with methadone]

BACKGROUND

To analyse prevalence of hidden hepatitis B infection (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), and tuberculosis infection in drug users (DU) in a maintenance programme with methadone (MPM).

PATIENTS AND METHOD

189 DU were tested for HBV, HCV, HIV and tuberculin test. Drug addition history and route of administration were evaluated.

RESULTS

Prevalence of HIV, HCV, and tuberculous infection was 29.2%, 75.9% and 59.3% respectively. Intravenous route, early use of heroin and delay to enter in MPM were significatively associated with HIV and HCV infections.

CONCLUSIONS

There is a high prevalence of tuberculous and HCV infections in DU. Early access to MPM could decrease prevalence of those infections.

The maternal-infant center in the control of hepatitis B

A seroepidemiologic survey of HBV infection was carried out in four population groups served by the Maternity Hospital of Majorca, an island in the Mediterranean. The prevalence of HBV markers (HBsAg, anti-HBs, anti-HBc), determined by enzyme-immunoassay, reached 17.2% among 864 parturients, 17.2% in 783 hospital personnel, 2.7% and 19.2% among the 186 children and 73 husbands of parturients with no HBV markers, 22.8% and 43.8%, respectively, among the 44 children and 48 husbands of HBsAg chronic carrier parturients. The prevalences of HBsAg in the same groups reached 0.9%, 1.5%, 0% and 0%, 11.4% and 2.1%, respectively. The carrier state represents 50% of all infection cases among children and 4.8% among husbands of carrier women. The prevalence of markers, which was especially high among personnel working in maintenance services (39.1%), on surgical wards (35.3%), among midwives (27.6%) and in cleaning and laundry services (27.1%), and laboratories (21.4%), is used as an indicator in defining priorities for the vaccination of people at risk. Sixty-seven newborn babies of HBsAg carrier mothers were administered one dose of HBIG and three doses of hepatitis B vaccine; at 12 months of age, the seroconversion rate was 98.5%, whereas 1 child (1.5%) became a chronic carrier. Maternity hospitals represent the ideal centers in which to carry out the detection of HBsAg in pregnant women prior to parturition, to ensure that all newborns of chronic carrier women receive passive-active immunization, and to screen their family contacts and vaccinate those who are found susceptible to the infection.