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1.
Langmuir ; 34(15): 4548-4553, 2018 04 17.
Article in English | MEDLINE | ID: mdl-29551068

ABSTRACT

Chiroptical methods have been proven to be superior compared to their achiral counterparts for the structural elucidation of many compounds. To expand the use of chiroptical systems to everyday applications, the development of functional materials exhibiting intense chiroptical responses is essential. Particularly, tailored and robust interfaces compatible with standard device operation conditions are required. Herein, we present the design and synthesis of chiral allenes and their use for the functionalization of gold surfaces. The self-assembly results in a monolayer-thin room-temperature-stable upstanding chiral architecture as ascertained by ellipsometry, X-ray photoelectron spectroscopy, and near-edge X-ray absorption fine structure. Moreover, these nanostructures anchored to device-compatible substrates feature intense chiroptical second harmonic generation. Both straightforward preparation of the device-compatible interfaces along with their chiroptical nature provide major prospects for everyday applications.

2.
Br J Dermatol ; 172(6): 1547-1554, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25645336

ABSTRACT

BACKGROUND: Transformed mycosis fungoides (TMF) large cells may express CD30 antigen, and because of this, the differential diagnosis between CD30-rich TMF and primary cutaneous anaplastic large-cell lymphoma (cALCL) may be difficult, and especially in distinguishing cALCL associated with MF vs. CD30-rich TMF. OBJECTIVES: To find clinical, histological and molecular diagnostic features useful for differential diagnosis between cALCL and CD30-rich TMF. To analyse and compare the prognostic value of clinical and pathological factors in these two diseases. MATERIAL AND METHODS: We conducted a retrospective study (1999-2012) of 32 patients with cALCL and 34 with CD30-rich TMF, seen in reference centres of the French Study Group of Cutaneous Lymphoma. Clinical, histological and molecular features were analysed and compared to determine their diagnostic and prognostic value. RESULTS: Comparison of the two groups showed that age ˃ 60 years, ≥ 5 skin lesions, early progression, absence of spontaneous regression and trunk involvement were significantly associated with the diagnosis of TMF. Abnormal T-cell phenotype and perforin expression were significantly more frequent in cALCL (both P < 0·001). Overall survival (OS) at 5 years was 77·4% for cALCL and 20·7% for CD30-rich TMF. Stage T3, ≥ 5 skin lesions, lower limb involvement for cALCL and stage T4, extracutaneous involvement, B symptoms, high levels of lactate dehydrogenase for CD30-rich TMF were associated with poor OS and progression-free survival. DUSP22 gene rearrangement had no diagnostic or prognostic value. CONCLUSIONS: Clinical features and outcome are the most discriminative to differentiate the two entities. Even histological and molecular markers were not fully specific; abnormal vs. normal T-cell phenotype and perforin expression may constitute helpful tools.


Subject(s)
Biomarkers, Tumor/metabolism , Ki-1 Antigen/metabolism , Lymphoma, Primary Cutaneous Anaplastic Large Cell/diagnosis , Mycosis Fungoides/diagnosis , Skin Neoplasms/diagnosis , Adolescent , Adult , Aged , Aged, 80 and over , Diagnosis, Differential , Female , France/epidemiology , Humans , Lymphoma, Primary Cutaneous Anaplastic Large Cell/mortality , Male , Middle Aged , Mycosis Fungoides/mortality , Perforin/metabolism , Phenotype , Retrospective Studies , Skin Neoplasms/mortality , T-Lymphocytes/pathology , Young Adult
3.
Opt Express ; 19(21): 20704-21, 2011 Oct 10.
Article in English | MEDLINE | ID: mdl-21997081

ABSTRACT

Clouds represent a critical factor in regulating the Earth's atmosphere and its energy balance. Satellite instruments can measure the energy balance and global atmospheric properties only through an accurate knowledge of the vertical profile of cloudiness, which is as yet one of the key shortages in atmospheric science. The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on-board the ENVISAT satellite, designed to infer the amount of atmospheric trace-gases, demonstrated also sensitivity to the radiation emitted from clouds. In order to model the effect of the geometrical extent of a cloud on MIPAS measurements, we developed a retrieval model capable to simulate cloud effects on broad spectral intervals accounting for the two-dimensional (2-D) variability of the atmosphere in the satellite orbit plane. The 2-D analysis revealed a sensitivity of MIPAS spectra to both the vertical and horizontal extents and the position of clouds along the instrument line of sight. One-dimensional models were found to underestimate Cloud Top Height (CTH) by approximating clouds as an infinite horizontal layer with a finite vertical extents. With the 2-D approach, we showed it is possible, for optically thin Polar Stratospheric Clouds (PSCs), to retrieve both CTH and horizontal dimension by analyzing simultaneously all the limb observations that come across the cloud with their field of view. For a selected case study we found a very good agreement for both PSC CTH and horizontal extents retrieved from MIPAS measurements and those retrieved from coincident CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarisation) measurements.

4.
J Mater Sci Mater Med ; 22(10): 2387-95, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21805331

ABSTRACT

Cosmeto-textile applications can be used in the treatment of chronic venous insufficiency in legs by means of elastic bandages loaded with natural products which possess flebotonic properties. We have developed an efficient synthetic procedure for the preparation of ß-cyclodextrin (ß-CD)-grafted viscose by means of a 2-step ultrasound-assisted reaction. The highly grafted fabric bearing bis-urethane bridged ß-CD has been characterized by ATR-FTIR and CP-MAS spectra and by an empiric colorimetric method which used phenolphthalein as the CD guest. We have also developed a suitable cosmetic preparation containing natural substances and extracts (aescin, menthol, Centella asiatica and Ginkgo biloba) to recharge the CD-grafted textile. The efficacy of the new cosmeto-textile has been corroborated by in vitro studies of diffusion through membranes, cutaneous permeation and accumulation in porcine skin. Aescin was taken as a reference compound and its concentration in the different compartments was monitored by HPLC analysis. This cost effective cosmeto-textile shows excellent application compliance and is easily recharged and so has the strong base characteristics needed for possible industrial production.


Subject(s)
Cellulose , Cyclodextrins/chemistry , Escin/chemistry , Venous Insufficiency/therapy , beta-Cyclodextrins/chemistry , Animals , Compression Bandages , Emulsions , Humans , Molecular Structure , Permeability , Skin , Swine
5.
Dermatology ; 221(2): 97-106, 2010.
Article in English | MEDLINE | ID: mdl-20558976

ABSTRACT

The term 'pigmented epithelioid melanocytoma' (PEM) has recently been proposed as a nosological framework grouping lesions formerly known as animal-type melanomas, sporadic epithelioid blue nevi and Carney complex-associated epithelioid blue nevi. Congenital PEMs have been reported extremely rarely and their prognosis is poorly known. Four-color fluorescent in situ hybridization (FISH) for melanocytic lesions is a recent method developed to assess the malignant potential of ambiguous melanocytic lesions. Here we describe 2 cases of congenital epithelioid and strongly pigmented melanocytic lesions consistent with PEM. No BRAF gene mutation was found in the 2 cases. FISH for melanocytic lesions was also performed. The first case proved entirely negative, whereas the second one showed a positive zone with an extra copy of chromosome 6. The prognosis and management of PEM are discussed, with a review of the available data on the history, demographics, molecular alterations and histopathological aspects of this entity. PEM seems to represent a unique low-grade melanocytic tumor with a limited potential of metastasis to lymph nodes, but a favorable long-term clinical course. The published data about FISH for melanocytic tumors, and especially PEM, are reviewed. Four-color FISH may be a useful tool to assess more accurately the prognosis of these tumors.


Subject(s)
Melanoma/congenital , Melanoma/pathology , Nevus, Blue/congenital , Nevus, Blue/pathology , Skin Neoplasms/congenital , Skin Neoplasms/pathology , Antigens, CD/analysis , Antigens, Differentiation, Myelomonocytic/analysis , Chromosomes, Human, Pair 6/genetics , Female , Humans , In Situ Hybridization, Fluorescence , Infant , Lymph Nodes/pathology , Male , Melanoma/diagnosis , Melanoma/genetics , Melanoma/surgery , Nevus, Blue/diagnosis , Nevus, Blue/genetics , Nevus, Blue/surgery , Pigmentation/genetics , Proto-Oncogene Proteins B-raf/genetics , Skin Neoplasms/diagnosis , Skin Neoplasms/genetics , Skin Neoplasms/surgery , Trisomy
6.
Opt Express ; 17(7): 5340-57, 2009 Mar 30.
Article in English | MEDLINE | ID: mdl-19333299

ABSTRACT

In this paper we propose a new approach to operate two-dimensional sensitivity studies on the observations of MIPAS, an experiment on board the ENVISAT satellite. The proposed analysis system is intended to evaluate the amount and the spatial distribution of the information that is carried by MIPAS observations with respect to the target atmospheric parameters. The new approach enables the definition and assessment of the target-dependent atmospheric sampling of the measurements. The amount of information is evaluated by merging MIPAS measurements, relative to different limb-scans, in a two-dimensional analysis that models the sensitivity of the spectral signals combined with the geometrical redundancy introduced by different observation geometries. The spatial distribution of the information that is obtained with our analysis highlights the advantage of using a two-dimensional retrieval system. Furthermore, within the two-dimensional context, this analysis provides crucial indications for the definition of the optimal retrieval grid and, therefore, for the best exploitation of existing measurements. The proposed analysis is also suited for the design of optimized observation strategies. The sensitivity analysis, applied in this paper to MIPAS observations, can be extended to other orbiting limb sounders that, like MIPAS, continuously measure the atmospheric emission along the orbit track.


Subject(s)
Algorithms , Atmosphere/analysis , Atmosphere/chemistry , Environmental Monitoring/methods , Refractometry/methods , Spacecraft , Reproducibility of Results , Sensitivity and Specificity
7.
Int J Pharm ; 346(1-2): 119-23, 2008 Jan 04.
Article in English | MEDLINE | ID: mdl-17618070

ABSTRACT

The study reports pig-skin permeation and skin accumulation of miconazole nitrate (MCZ) from positively charged microemulsions containing water, 1-decanol/1-dodecanol (2:1, w/w), lecithin and/or decyl polyglucoside at different weight ratios, propylene glycol, 1,2 hexanediol and a cationic charge-inducing agent (stearylamine (ST), l-alanine benzyl ester (ALAB) or cetyltrimethylammonium bromide (CTAB)). Zeta-potential values of the positively charged microemulsions ranged from 14.2 to 37.5 mV and mean droplet size from 6.0 to 16.8 nm. In vitro pig-skin permeation of MCZ after a single 24h application was negligible for all microemulsions; accumulation from positively charged microemulsions was nearly twice that from their negatively charged counterparts. The increased accumulation might be ascribed to the interaction between positive microemulsive systems and negatively charged skin sites; no significant difference was observed among the various cationic charge-inducing agents. Skin accumulation from the microemulsion containing most lecithin was lower than those of other microemulsions; this was ascribed to the phase transformation from microemulsion to a liquid crystal system after skin contact. These results suggest that positively charged microemulsions could be used to optimize drug targeting without a concomitant increase in systemic absorption; ALAB, an ester of a natural amino acid, is an appropriate cationic charge-inducing agent.


Subject(s)
Alanine/metabolism , Antifungal Agents/metabolism , Miconazole/metabolism , Skin/metabolism , Administration, Topical , Alanine/analogs & derivatives , Alanine/chemistry , Animals , Antifungal Agents/chemistry , Emulsions , In Vitro Techniques , Miconazole/chemistry , Skin Absorption , Swine
9.
J Microencapsul ; 24(7): 660-72, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17763060

ABSTRACT

Insulin-loaded solid lipid nanoparticles (SLN), obtained by the solvent-in-water emulsion-diffusion technique, were produced using isovaleric acid (IVA) as organic phase, glyceryl mono-stearate (GMS) as lipid, soy lecithin and sodium taurodeoxycholate (TDC) as emulsifiers. IVA, a partially water-miscible solvent with low toxicity, was used to dissolve both insulin and lipids. SLN of spherical shape were obtained by simple water dilution of the O/W emulsion. Analysis of SLN content after processing showed interesting encapsulation efficiency with respect to therapeutic doses; moreover, insulin did not undergo any chemical modification within the nanoparticles and most of it remained stable after incubation of the SLN with trypsin solution. The biological activity of insulin, i.e. the ability to decrease glycemia in rats, was not negatively influenced by the SLN production process, as after subcutaneous administration of insulin extracted from SLN to animals, the blood glucose levels were quite similar to those obtained after administration of a conventional insulin suspension. Consequently, SLN seem to have interesting possibilities as delivery systems for oral administration of insulin.


Subject(s)
Insulin/chemistry , Lipids/chemistry , Nanoparticles/chemistry , Water/chemistry , Administration, Oral , Animals , Calorimetry, Differential Scanning/methods , Cattle , Chromatography, High Pressure Liquid , Diffusion , Hydrogen-Ion Concentration , Insulin/administration & dosage , Insulin/metabolism , Rats , Solvents/chemistry , Temperature , Time Factors
10.
Opt Express ; 15(16): 10458-72, 2007 Aug 06.
Article in English | MEDLINE | ID: mdl-19547399

ABSTRACT

We report the results of a study aimed at the assessment of the trade-off between precision and horizontal resolution of the retrieval products of MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) operating onboard the ENVIronmental SATellite. By exploiting different observation setups we could perform the study by acting on both the retrieval and the sampling grids. Our results are compared with those previously obtained on simulated observations [Appl. Opt. 43, 1-11 (2004)]. We show that the horizontal sampling of the atmosphere operated by the spectrometer cannot be pushed beyond some limits without inducing unacceptable correlations among the retrieved profiles. These correlations show-up only when using a two-dimensional retrieval algorithm and can be evaluated through the instabilities that they trigger in the horizontal distribution of the retrieval products. In order to reduce these instabilities we compare the strategy of degrading the retrieval grid with the strategy of applying horizontal regularization. We discuss the different trade-off between precision and spatial resolution connected with the two strategies. The method adopted in this study, is applicable to any orbiting limb sounder measuring along the orbit track.

11.
J Cosmet Sci ; 57(4): 261-77, 2006.
Article in English | MEDLINE | ID: mdl-16957807

ABSTRACT

Two commercial anti-aging products, RETI C and RETI C concentrate emulsions, containing retinol and vitamin C, were studied. The concentration of vitamin A was determined over time, subjecting the creams to an accelerated stability test. Both emulsions, when stored at 25 degrees C, showed a moderate decrease over time in retinol concentration, while after storage at 40 degrees C the percentage of retinol degraded increased over time. Under UVA irradiation, the retinol degraded to a greater extent than under UVB irradiation, both in RETI C and RETI C concentrate emulsions. In order to verify the anti-aging effectiveness of the emulsions, an in vivo test on some female volunteers was carried out, evaluating the visible results of the application of the creams on the skin surface. The creams were rather unstable after storage at 40 degrees C, but they were effective in treating the signs of aging and in reducing facial wrinkles.


Subject(s)
Ascorbic Acid/chemistry , Ascorbic Acid/pharmacology , Cosmetics/chemistry , Cosmetics/pharmacology , Skin Aging/drug effects , Vitamin A/chemistry , Vitamin A/pharmacology , Adult , Aged , Ascorbic Acid/radiation effects , Cosmetics/radiation effects , Drug Stability , Electric Conductivity , Emulsions/chemistry , Emulsions/pharmacology , Female , Humans , Middle Aged , Photochemistry , Rheology , Ultraviolet Rays , Viscosity , Vitamin A/radiation effects
12.
J Cosmet Sci ; 56(4): 227-51, 2005.
Article in English | MEDLINE | ID: mdl-16130045

ABSTRACT

Hemp-seed oil has several positive effects on the skin: thanks to its unsaturated fatty acid (PUFA) content it alleviates skin problems such as dryness and those related to the aging process. We present a comparative study of hemp-seed and olive oils, determining some physicochemical indices and evaluating their stability against oxidation. The peroxide value of hemp-seed oil was below 20, the threshold limit for edible oils. Hemp-seed oil was less stable against peroxidation than olive oil, but MDA and MONO assays showed its stability to be above expectations. The chlorophyll contained in extra virgin olive oil had a higher photostability than that contained in hemp-seed oil, possibly due to the larger amount of antioxidant in the olive oil. A certain amount of Vitamin E was found in hemp-seed oil. Since quality analyses indicated that hemp-seed oil is relatively stable, emulsions were prepared with the two oils, and their stability and rheological characteristics were tested. Some of the resulting gel-emulsions were suitable for spraying on the skin.


Subject(s)
Cannabis/chemistry , Cosmetics/chemistry , Plant Oils/chemistry , Seeds/chemistry , Emulsions/chemistry , Hydrogen-Ion Concentration , Malondialdehyde/analysis , Olive Oil , Oxidation-Reduction , Refractometry , Spectrophotometry, Ultraviolet , Viscosity , Vitamin E/analysis
13.
Int J Pharm ; 288(2): 281-8, 2005 Jan 20.
Article in English | MEDLINE | ID: mdl-15620868

ABSTRACT

The study aimed to produce solid lipid insulin-loaded micro-particles by the solvent-in-water emulsion-diffusion technique, using isobutyric acid as solvent phase, glyceryl monostearate or cetyl palmitate as lipid, soya lecithin and taurodeoxycholate as emulsifiers. Isobutyric acid, a partially water-miscible solvent with low toxicity, was used due to its high insulin-solubilization capacity. Solid lipid micro-particles of spherical shape were prepared by simple dilution of the emulsion with water. To increase the lipid load the process was conducted at 50 degrees C, and in order to reach sub-micron size, a high-shear homogeniser was used. Insulin encapsulation efficiency was about 80%. Analysis of microsphere content after processing showed that insulin did not undergo any chemical modification within the micro-particles. The in vitro release of insulin from the micro-particles was very low, and an initial burst effect of 20% of the dose was observed. After treatment of the solid lipid micro-particles with pepsin solution, an insulin loss of about 24% of the total englobed insulin was observed. The solid lipid micro-particles appear to have interesting possibilities as delivery systems for oral administration of insulin.


Subject(s)
Drug Carriers/chemistry , Insulin/chemistry , Lipids/chemistry , Microspheres , Solvents/chemistry , Animals , Cattle , Diffusion , Drug Carriers/pharmacokinetics , Emulsions , Insulin/pharmacokinetics , Lipids/pharmacokinetics , Solubility , Solvents/pharmacokinetics , Water/chemistry
14.
J Cosmet Sci ; 55(3): 233-52, 2004.
Article in English | MEDLINE | ID: mdl-15264052

ABSTRACT

Vitamin A palmitate photostability in relation to UVA and UVB was tested in hydroxy ethyl cellulose hydrogels at pH 4.0, 5.6, 7.0, and 8.0, alone and with the addition of sunscreens (3,4-methylbenzilidencamphor or butyl methoxy dibenzoylmethane) or an antioxidant (butylated hydroxy toluene). The photostability of vitamin A palmitate was also tested in encapsulated systems (Tagravit A1 microcapsules, Lipotec liposomes, phosphatidylcholine liposomes, and Lipotec nanocapsules) dispersed in gels at pH 5.6 and 7.0. The stability of retinyl palmitate over time in hydroxy ethyl cellulose hydrogels at pH 5.6 and 7.0 (stored one month at 25 degrees C or 40 degrees C), alone or with butylated hydroxy toluene, was also tested. The stability of retinyl palmitate over time in encapsulated systems, dispersed in gels at pH 5.6 and 7.0, was also studied. O/W emulsions were also prepared to compare the stability of vitamin A palmitate introduced in a lipophilic/hydrophilic medium (O/W emulsions) and a hydrophilic medium (hydrogels). HPLC analysis showed that encapsulated systems such as Lipotec nanocapsules, Tagravit A1 microcapsules, phosphatidylcholine liposomes, and Lipotec liposomes protect the vitamin A ester over time from hydrolysis and from oxidation to retinaldeide and retinoic acid, and that Lipotec nanocapsules and phosphatidylcholine liposomes also improve the vitamin's photostability. A change in pH (from 5.6 to 7.0) of the gels did not influence the vitamin ester's stability. pH levels of 4.0 and 8.0 determined a decrease in the stability of retinyl palmitate in the gels. A high concentration of sunscreens improved the photostability of retinyl palmitate in the gels at pH 5.6 and 7.0. Butylated hydroxy toluene protected retinyl palmitate from degradation induced by light at all the pH levels studied and by heat at pH 5.6 and 7.0, as can be seen from the study of the photostability of vitamin A palmitate under UVB and UVA and of stability over time. Rheological studies showed a slight decrease in the viscosity of the gels after UVB-UVA irradiation and a higher decrease in the viscosity of the gels and the emulsions after storage at 25 degrees C and 40 degrees C. This decrease can be attributed to a partial degradation of hydroxy ethyl cellulose and of emulsifier, as can be seen from the decrease in shear stress versus shear rate values under these conditions of storage, denoting a depolymerization of the rheological modifier.


Subject(s)
Vitamin A/analogs & derivatives , Vitamin A/chemistry , Animals , Diterpenes , Drug Stability , Emulsions/chemistry , Hydrogels/chemistry , Hydrogen-Ion Concentration , Liposomes/chemistry , Retinyl Esters , Skin/metabolism , Skin Absorption , Swine , Ultraviolet Rays , Viscosity , Vitamin A/pharmacokinetics
15.
J Cosmet Sci ; 55(2): 139-48, 2004.
Article in English | MEDLINE | ID: mdl-15131725

ABSTRACT

An o/w microemulsion formulated using lecithin and an alkyl glucoside as mild, non-irritant surfactants was proposed as a cosmetic vehicle for arbutin and kojic acid, naturally occurring whitening agents. After assessing the physicochemical stability of the microemulsion in the presence and absence of whitening agents, several perfumed compositions, developed using fragrant molecules of natural or synthetic origin, were introduced, and the olfactory impact of the perfumed microemulsion was evaluated. The photostability to UVB irradiation of both whitening agents was determined in aqueous solutions and in microemulsions, and also in the presence of the perfumed compositions. The stability of arbutin and kojic acid was higher in microemulsions than in aqueous solutions, and only in some cases did the presence of odorous molecules appear to influence it: linalool exerted some protective effect towards kojic acid photodegradation.


Subject(s)
Cosmetics , Light , Arbutin/chemistry , Emulsions , Pyrones/chemistry
16.
J Cosmet Sci ; 54(5): 451-62, 2003.
Article in English | MEDLINE | ID: mdl-14605687

ABSTRACT

In recent years, transparent dispersions or diluted milks have been used as sunscreens. These products contain water-soluble sunscreen agents, and quite frequently are washed away from the skin. However, O/W microemulsions are now being prepared as transparent vehicles for sunscreens. They are waterproof, nonsticky, and easily spreadable. The microemulsions are prepared by using pseudoternary diagrams, by combining lipids with surfactant blends and a polar phase. Soya lecithin and decylpolyglucose produce transparent systems with the lowest percentage of surfactants. These microemulsions contain 4-methylbenzilidene camphor or octylmethoxycinnamate as sunscreen agents. Cyclomethicone, menthol, and allantoin give products a good skin feel, and stearyl methicone gives the waterproof effect. These systems show a Newtonian flux. Little permeation of the sunscreens' trough lipophilic and hydrophilic membrane is evidenced.


Subject(s)
Emulsions , Pharmaceutical Vehicles , Sunscreening Agents/administration & dosage , Microscopy , Scattering, Radiation
17.
J Cosmet Sci ; 54(5): 513-24, 2003.
Article in English | MEDLINE | ID: mdl-14605692

ABSTRACT

The treatments used in many commercial sunscreen pigments (organic additives and inorganic surface coating) to lower the pigments' ability to degrade molecules under photocatalytic conditions are effective in inhibiting the degradation of phenol, but much less effective towards the degradation of salicylic acid. The reason is in the different degradation pathways that phenol and salicylic acid follow under photocatalytic conditions. The treatments are thus effective in inhibiting the degradation pathways initiated by Ti(IV)-*OH(surf) (also named *OH(ads)), as in the case of phenol, but much less effective towards electron-transfer processes involving surface complexes, as in the case of salicylic acid. These results indicate that the techniques currently adopted by the cosmetic industry to develop organic additives for use as pigment treatments are likely to be inadequate. The problem most likely is that treatments are optimized following the inhibition of the photocatalytic degradation of a single model molecule, which results in blocking just one photocatalytic degradation pathway (usually the one initiated by Ti(IV)-*OH(surf)) and not the other (electron transfer processes). The possible implications for sunscreen pigments are briefly discussed, and a new approach for the evaluation of the photocatalytic activity of inorganic sunscreens is proposed.


Subject(s)
Phenols/chemistry , Pigments, Biological/chemistry , Salicylic Acid/chemistry , Sunscreening Agents/standards , Titanium/chemistry , Catalysis , Photochemistry
18.
Int J Pharm ; 240(1-2): 85-94, 2002 Jun 20.
Article in English | MEDLINE | ID: mdl-12062504

ABSTRACT

Vitamin A and vitamin A palmitate photostability were tested in different media. Ethanol and octyl octanoate solutions of these two vitamins, as such and with the addition of sunscreens (3,4 methylbenzilidencanfora, butyl methoxy dibenzoylmethane and octyl methoxycinnamate) or beta-carotene and butylated hydroxy toluene, were analysed spectrophotometrically after UVB or UVA irradiation. An O/W fluid emulsion with 0.5% w/w of retinyl palmitate, with and without butylated hydroxy toluene, was prepared. The oil containing the vitamin was extracted with HCl and aluminium sulfate and analysed spectrophotometrically after UVB or UVA irradiation. The fluid emulsion containing retinyl palmitate with and without butylated hydroxy toluene was stored at different temperatures and analysed every week spectrophotometrically for a month. Of the sunscreens tested butyl methoxy dibenzoylmethane showed the strongest protective action towards vitamin A and vitamin A palmitate, whereas beta-carotene did not protect either vitamin. Butylated hydroxy toluene inhibited the photodegradation of both vitamins dissolved in octyl octanoate, suggesting that oxygen may be involved in their degradation. O/W emulsion promoted slightly the degradation of vitamin A ester. Butylated hydroxy toluene protected retinyl palmitate from degradation induced by light and heat.


Subject(s)
Ultraviolet Rays , Vitamin A/chemistry , Vitamin A/radiation effects , Butylated Hydroxytoluene/chemistry , Diterpenes , Drug Stability , Emulsions , Retinyl Esters , Solubility , Spectrophotometry , Sunscreening Agents/chemistry , Time Factors , Vitamin A/analogs & derivatives , beta Carotene/chemistry
19.
Appl Opt ; 40(12): 1872-85, 2001 Apr 20.
Article in English | MEDLINE | ID: mdl-18357187

ABSTRACT

We propose a new approach to the analysis of limb-scanning measurements of the atmosphere that are continually recorded from an orbiting platform. The retrieval is based on the simultaneous analysis of observations taken along the whole orbit. This approach accounts for the horizontal variability of the atmosphere, hence avoiding the errors caused by the assumption of horizontal homogeneity along the line of sight of the observations. A computer program that implements the proposed approach has been designed; its performance is shown with a simulated retrieval analysis based on a satellite experiment planned to fly during 2001. This program has also been used for determining the size and the character of the errors that are associated with the assumption of horizontal homogeneity. A computational strategy that reduces the large number of computer resources apparently demanded by the proposed inversion algorithm is described.

20.
J Forensic Sci ; 45(4): 820-3, 2000 Jul.
Article in English | MEDLINE | ID: mdl-10914577

ABSTRACT

The identification of insects found on a dead body can lead to the estimation of the time of death (postmortem interval). We report an updated version of an established method based on sequence analysis of PCR products from a region of the cytochrome b oxidase subunit I mitochondrial gene of different members of the family Calliphoridae, by sequencing six European species: Lucilia sericata (Meigen), Lucilia caesar (Linné), Lucilia illustris (Meigen), Calliphora vicina (Robineau-Desvody), Calliphora vomitoria (Linné), Protophormia terraenovae (Robineau-Desvody) and one Guianese species: Cochliomyia macellaria (Fabricius). This technique provided clear results when applied to the larvae and we also report the identification of empty puparia.


Subject(s)
Diptera/genetics , Electron Transport Complex IV/genetics , Forensic Medicine , Animals , Autopsy , Base Sequence , Death , Humans , Larva , Molecular Sequence Data , Polymerase Chain Reaction , Sequence Analysis, DNA , Time Factors
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