Pesticide residues in Tunisian table grapes and associated risk for consumer's health.

Sixty-four table grape samples from different regions of Tunisia were collected during three consecutive years (2015-2017). The presence of 96 pesticides, including dithiocarbamates, was assessed. Pesticides identification and quantification were performed by liquid or gas chromatography, coupled to tandem mass spectrometry. All samples contained multiple residues (4 to 24 residues), with an average of 11.6 residues per sample. Individual concentrations of pesticides in grapes ranged from 0.01 to 5.86 mg kg-1. For at least one chemical compound, exceedances of the European Maximum Residue Limits were found in 94% of the samples. To assess the potential risk of pesticides through consumption of grapes, the acute exposure was estimated by the determination of predicted short term intake which is expressed as a percentage of Acute Reference Dose (ARfD), for non-compliances of pesticides. The exceedance of ARfD was associated with carbofuran, carbendazim, chlorpyrifos, deltamethrin, dimethoate and omethoate. Consequently, these pesticides could present a risk for consumer's health.

Twenty-nine cases of lupus vulgaris.

UNLABELLED: Cutaneous tuberculosis (TB) is a rare presentation of extrapulmonary TB. Lupus vulgaris (LV) is a common presentation of cutaneous TB. OBJECTIVE: We aimed to describe the epidemiological, clinical, paraclinical, therapeutic, and outcome features of LV in the region of Sfax, Tunisia. PATIENTS AND METHODS: We conducted a retrospective and descriptive study of LV case patients observed at the dermatology department of the Hédi Chaker Hospital (Sfax) over a 34-year period. RESULTS: A total of 88 cutaneous TB case patients were identified during the study period, including 29 patients presenting with LV. All patients had clinical features of the most common presentation of LV. The results of skin biopsies indicated tuberculoid granulomas without caseous necrosis. Patients received TB treatment. LV progressed to squamous cell carcinoma in one patient. CONCLUSION: In Tunisia, endemic country for TB, LV should be considered in patients presenting with an old skin lesion.

Validity and reliability of the session-RPE method for quantifying training load in karate athletes.

AIM: To test the construct validity and reliability of the session rating of perceived exertion (sRPE) method by examining the relationship between RPE and physiological parameters (heart rate: HR and blood lactate concentration: [La --] ) and the correlations between sRPE and two HR--based methods for quantifying internal training load (Banister's method and Edwards's method) during karate training camp. METHODS: Eighteen elite karate athletes: ten men (age: 24.2 ± 2.3 y, body mass: 71.2 ± 9.0 kg, body fat: 8.2 ± 1.3% and height: 178 ± 7 cm) and eight women (age: 22.6 ± 1.2 y, body mass: 59.8 ± 8.4 kg, body fat: 20.2 ± 4.4%, height: 169 ± 4 cm) were included in the study. During training camp, subjects participated in eight karate--training sessions including three training modes (4 tactical--technical, 2 technical--development, and 2 randori training), during which RPE, HR, and [La -- ] were recorded. RESULTS: Significant correlations were found between RPE and physiological parameters (percentage of maximal HR: r = 0.75, 95% CI = 0.64--0.86; [La --] : r = 0.62, 95% CI = 0.49--0.75; P < 0.001). Moreover, individual sRPE was significantly correlated with two HR--based methods for quantifying internal training load ( r = 0.65--0.95; P < 0.001). The sRPE method showed the high reliability of the same intensity across training sessions (Cronbach's α = 0.81, 95% CI = 0.61--0.92). CONCLUSION: This study demonstrates that the sRPE method is valid for quantifying internal training load and intensity in karate.

Investigation of exciton photodissociation, charge transport and photovoltaic response of poly(N-vinyl carbazole):TiO(2) nanocomposites for solar cell applications.

The photogeneration of charge carriers in spin-coated thin films of nanocrystalline (nc-)TiO(2) particles dispersed in a semiconducting polymer, poly(N-vinylcarbazole) (PVK), has been studied by photoluminescence and charge transport measurements. The solvent and the TiO(2) particle concentration have been selected to optimize the composite morphology. A large number of small domains leading to a large interface and an improved exciton dissociation could be obtained with tetrahydrofuran (THF). The charge transport mechanism and trap distribution at low and high voltage in ITO/nc-TiO(2):PVK/Al diodes in the dark could be identified by current-voltage measurements and impedance spectroscopy. The transport mechanism is space charge limited with an exponential trap distribution in the high voltage regime (1-4 V), whereas a Schottky process with a barrier height of about 0.9 eV is observed at low bias voltages (<1 V). The current-voltage characteristics under white illumination have shown a dramatic increase of the short circuit current density J(sc) and open circuit voltage V(oc) for a 30% TiO(2) volume content corresponding to the morphology exhibiting the best dispersion of TiO(2) particles. A degradation of the photovoltaic properties is induced at higher compositions by the formation of larger TiO(2) aggregates. A procedure has been developed to extract the physical parameters from the J-V characteristics in the dark and under illumination on the basis of an equivalent circuit. The variation of the solar cell parameters with the TiO(2) composition confirms that the photovoltaic response is optimum for 30% TiO(2) volume content. It is concluded that the photovoltaic properties of nc-TiO(2):PVK nanocomposites are controlled by the interfacial area between the donor and the acceptor material and are limited by the dispersion of the TiO(2) nanoparticles in the polymer.

Reference phase-shifter for measuring high power microwave impedance by using a phase modulation method.

A basic mechanical phase-shifter is described and proposed for use as a reference circuit for impedance measurements with a phase modulation method. It consists of a section of a curved rectangular waveguide, the length of which is mechanically varied with a stepper motor. The phase-shifter functions without gears. It can be used successfully in industrial set-ups with a pulsed or CW generator which are of low stability in frequency and in amplitude.