The Chemical Evolution of the Milky Way: the Three Infall Model

We present a new chemical evolution model for the Galaxy that assumes three main infall episodes of primordial gas for the formation of halo, thick and thin disk, respectively. We compare our results with selected data taking into account NLTE effects. The most important parameters of the model are (i) the timescale for gas accretion, (ii) the efficiency of star formation and (iii) a threshold in the gas density for the star formation process, for each Galactic component. We find that, in order to best fit the features of the solar neighbourhood, the halo and thick disk must form on short timescales (~0.2 and ~1.25 Gyr, respectively), while a longer timescale is required for the thin-disk formation. The efficiency of star formation must be maximum (10 Gyr-1) during the thick-disk phase and minimum (1 Gyr-1) during the thin-disk formation. Also the threshold gas density for star formation is suggested to be different in the three Galactic components. Our main conclusion is that in the framework of our model an independent episode of accretion of extragalactic gas, which gives rise to a burst of star formation, is fundamental to explain the formation of the thick disk. We discuss our results in comparison to previous studies and in the framework of modern galaxy formation theories.Comment: 12 pages, 7 figures, accepted for publication in MNRA

Erythema-directed digital photography for the enhanced evaluation of topical treatments for acne vulgaris.

n/

The Cupuacu (Theobroma Grandiflorum) fruit. High performance liquid chromatographic determination of antioxidant phenolic substances in cupuacu seed powder

A method for the qualitative analysis of antioxidant phenolic substances in cupuacu seed powder by high performance liquid chromatography is described. We have used n-exhane to degrease the cupuacu seed powder and a methanol-water (80:20) solution for the extraction of the analytes. HPLC separation was carried out by using a binary gradient elution utilizing methanol-acetonitrile 1:1 (v/v) and 0.5% (w/v) phosphoric acid. Spectral scans were continuously collected in the range 210-370 nm and the spectrophotometric chromatogram was plotted at 280 nm. Spectrofluorimetric detection was carried out with excitation at 280 nm and emission at 330 nm. Epicatechin and quercetin were identified by comparing the chromatographic behaviour and the UV spectrum of the extracted components with those of pure standards, while the spectrofluorimetric detection, by stopped flow technique, has allowed the identification of catechin and has confirmed the spectrophotometric identification of epicatechin

Cosmetics for acne: indications and recommendations for an evidence-based approach.

AIM: The aim of this review was to evaluate, by a thorough revision of the literature, the true efficacy of currently available topic and systemic cosmetic acne agents. METHODS: The efficacy of currently available cosmetic acne agents has been retrospectively evaluated via thorough revision of the literature on matched electronic databases (PubMed). All retrieved studies, either randomized clinical trials or clinical trials, controlled or uncontrolled were considered. RESULTS: Scientific evidence suggests that most cosmetic products for acne may enhance the clinical outcome. Cleansers should be indicated to all acne patients; those containing benzoyl peroxide or azelaic/salicylic acid/triclosan show the best efficacy profile. Sebum-controlling agents containing nicotinamide or zinc acetate may minimize excessive sebum production. Cosmetics with antimicrobial and anti-inflammatory substances such as, respectively, ethyl lactate or phytosphingosine and nicotinamide or resveratrol, may speed acne recovery. Topical corneolytics, including retinaldehyde/glycolic acid or lactic acid, induce a comedolytic effect and may also facilitate skin absorption of topical drugs. Finally, the use of specific moisturizers should be strongly recommended in all acne patients. CONCLUSION: Cosmetics, if correctly prescribed, may improve the performance of the therapy, whereas wrong procedures and/or inadequate cosmetics may worsen acne. Cosmetological recommendations may allow clinicians to make informed decisions about the role of various cosmetics and to indentify the appropriate indications and precautions. The choice of the most effective product should take into consideration the ongoing pharmacological therapy and acne type/severity as well

Experimental Evidence For Self-Similar Structures In The Aggregation Of Porphyrins In Aqueous Solutions

We have studied the aggregation of the porphyrin t-H₂Pagg in aqueous solution by light scattering. The intensity profile of the elastically scattered light, studied in the exchanged wave-vector range 0.2 ≤ q ≤ 31.4 μ m⁻¹, indicates that the aggregation produces large monodisperse clusters having a fractal structure, and is driven by diffusion-limited aggregation kinetics. Additional measurements performed at different q values confirm such a picture giving a hydrodynamic radius R(H) consistent with the radius of gyration R(g) measured by elastic scattering. This is explained taking into account the q² dependence observed in the mean decay rate of the intensity-intensity correlation function and the effect on this latter dynamical quantity of anisotropies in the cluster structure

Management of a pregnant woman with fibromuscular dysplasia

No abstract available

Electromotive instillation of mitomycin immediately before transurethral resection for patients with primary urothelial non-muscle invasive bladder cancer: a randomised controlled trial.

BACKGROUND: The clinical effect of intravesical instillation of chemotherapy immediately after transurethral resection of bladder tumours (TURBT) has recently been questioned, despite its recommendation in guidelines. Our aim was to compare TURBT alone with immediate post-TURBT intravesical passive diffusion (PD) of mitomycin and immediate pre-TURBT intravesical electromotive drug administration (EMDA) of mitomycin in non-muscle invasive bladder cancer. METHODS: We did a multicentre, randomised, parallel-group study in patients with primary non-muscle invasive bladder cancer in three centres in Italy between Jan 1, 1994, and Dec 31, 2003. Patients were randomly assigned to receive treatment by means of stratified blocked randomisation across six strata. Patients and physicians giving the interventions were aware of assignment, but it was masked from outcome assessors and data analysts. Patients were randomly assigned to receive TURBT alone, immediate post-TURBT instillation of 40 mg PD mitomycin dissolved in 50 mL sterile water infused over 60 min, or immediate pre-TURBT instillation of 40 mg EMDA mitomycin dissolved in 100 mL sterile water with intravesical 20 mA pulsed electric current for 30 min. Our primary endpoints were recurrence rate and disease-free interval. Analyses were done by intention to treat. Follow-up for our trial is complete. This study is registered with ClinicalTrials.gov, number NCT01149174. FINDINGS: 124 patients were randomly assigned to receive TURBT alone, 126 to receive immediate post-TURBT PD mitomycin, and 124 to receive immediate pre-TURBT EMDA mitomycin. 22 patients were excluded from our analyses because they did meet our eligibility criteria after TURBT: 11 had stage pT2 disease and 11 had carcinoma in situ. Median follow-up was 86 months (IQR 57-125). Patients assigned to receive EMDA mitomycin before TURBT had a lower rate of recurrence (44 [38%] of 117) than those assigned to receive PD mitomycin after TURBT (70 [59%] of 119) and TURBT alone (74 [64%] of 116; log-rank p<0·0001). Patients assigned to receive EMDA mitomycin before TURBT also had a higher disease-free interval (52 months, IQR 32-184) than those assigned to receive PD mitomycin after TURBT (16 months, 12-168) and TURBT alone (12 months, 12-37; log-rank p<0·0001). We recorded persistent bladder symptoms after TURBT in 18 (16%) of 116 patients in the TURBT-alone group (duration 3-7 days), 37 (31%) of 119 in the PD mitomycin post-TURBT group (duration 20-30 days), and 24 (21%) of 117 in the EMDA mitomycin pre-TURBT group (duration 7-12 days); haematuria after TURBT in eight (7%) of 116 patients in the TURBT-alone group, 16 (13%) of 119 in the PD mitomycin post-TURBT group, and 11 (9%) of 117 in the EMDA mitomycin pre-TURBT group; and bladder perforation after TURBT in five (4%) of 116 patients in the TURBT-alone group, nine (8%) of 119 in the PD mitomycin post-TURBT group, and seven (6%) of 117 in the EMDA mitomycin pre-TURBT group. INTERPRETATION: Intravesical EMDA mitomycin before TURBT is feasible and safe; moreover, it reduces recurrence rates and enhances the disease-free interval compared with intravesical PD mitomycin after TURBT and TURBT alone