Noninvasive Assessment of UV-induced Skin Damage: Comparison of Optical Measurements to Histology and MMP Expression

Acute exposure to UV radiation (UVR) causes visible skin damage such as erythema and results in local and systemic immunosuppression while chronic exposure can result in photocarcinogenesis. These deleterious effects can be quantified by histology and by bioassays of key biological markers, including matrix metalloproteinases (MMPs), or tryptophan moieties. We now report our results in quantifying UV skin damage with noninvasive optical methods based on reflectance and fluorescence spectroscopy and compare these noninvasive measurements to histopathology and MMP-13 expression. A solar simulator with spectral output nearly identical to that of solar radiation was developed and used in our experiments. SKH1 hairless mice were exposed to solar-simulated UVR at a total dose of 21 MED delivered over 10 weeks. Changes in oxygenated and deoxygenated hemoglobin were measured by diffuse reflectance spectroscopy, and tryptophan changes were monitored via a fluorescence monitor. Our results show that there is an increase in erythema, skin fluorescence, sunburn cells and MMP-13 after a series of suberythemal doses of UV irradiation on a hairless mouse animal model. Increased skin fluorescence is observed with increasing UV exposure. The levels of MMP-13 increase as the cumulative UV dose increases but their increase does not correspond to noninvasively measured changes.     

Simple Sulfinate Synthesis Enables CH Trifluoromethylcyclopropanation

A simple method to convert readily available carboxylic acids into sulfinate salts by employing an interrupted Barton decarboxylation reaction is reported. A medicinally oriented panel of ten new sulfinate reagents was created using this method, including a key trifluoromethylcyclopropanation reagent, TFCS‐Na. The reactivity of six of these salts towards C? H functionalization was field‐tested using several different classes of heterocycles.     

Decontamination of textile wastewater via TiO2/activated carbon composite materials

Water scarcity and pollution rank equal to climate change as the most urgent environmental turmoil for the 21st century. To date, the percolation of textile effluents into the waterways and aquifer systems, remain an intricate conundrum abroad the nations. With the renaissance of activated carbon, there has been a steadily growing interest in the research field. Recently, the adoption of titanium dioxide, a prestigious advanced photo-catalyst which formulates the new growing branch of activated carbon composites for enhancement of adsorption rate and discoloration capacity, has attracted stern consideration and supports worldwide. Confirming the assertion, this paper presents a state of art review of titanium dioxide/activated carbon composites technology, its fundamental background studies, and environmental implications. Moreover, its major challenges together with the future expectation are summarized and discussed. Conclusively, the expanding of activated carbons composites material represents a potentially viable and powerful tool, leading to the plausible improvement of environmental conservation.     

Diastereoselective formation of a dipalladium(I) complex supported by a bridging tetradentate ligand,and oxidative addition of RS-H across a phosphine-bridged Pd(I)-Pd(I) bond

The ligand CH2(P(o-C6H4NMe2)2)2 (dmapm) gives access to the first example of a dipalladium(I) complex supported by a tetradentate ligand, Pd2Cl2(mu-N,P,P,N-dmapm), which, unlike the well-known Pd2X2(mu-dppm)2 complexes (X = halide, dppm = bis(diphenylphosphino)methane), reacts with thiols to give addition of RS-H across a phosphine-bridged Pd-Pd bond.     

Bildung von Diphosphaten aus geschmolzenem Natriumtrimetaphosphat, 3. Mitt.

Zusammenfassung Beim Auflösen der Oxide von Ti(IV), Ni und Co in geschmolzenem Na₃P₃O₉ bilden sich die Diphosphate Na₂(TiO) P₂O₇, Na₂NiP₂O₇ und Na₂CoP₂O₇. Beim Auslaugen der erstarrten Schmelze mit Wasser tritt auch Na₂Co₃(P₂O₇)₂·4 H₂O auf; ein entsprechendes Hydrat wird auch bei Mn(II) gefunden. Außerdem bildet Mn (II) ein Polyphosphat [Mn (PO₃)₂] _n . — Beim Auflösen eines Gemisches aus SrO und PbO in wechselnden Mengenverhältnissen entstehen nebeneinander Mischkristalle von Na₂(Sr, Pb) P₂O₇ mit wechselndem Verhältnis Sr,Pb und von einem Ultraphosphat [(Sr, Pb) P₄O₁₁] _n mit dem konstanten Verhältnis Sr,Pb=0,66,0,34. — Die Polyphosphate von Mn und von Sr–Pb werden papierchromatographisch und IR-spektroskopisch untersucht. — Die Bildung von Diphosphaten aus einer Polyphosphatschmelze wird an Hand der hier und früher beschriebenen Befunde zu deuten versucht.

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On dissolving the oxides of Ti(IV), Ni or Co in molten Na₃P₃O₇ the diphosphates Na₂(TiO) P₂O₇, Na₂NiP₂O₇ and Na₂CoP₂O₇ are formed respectively. Mn(II) forms a polyphosphate [Mn(PO₃)₂] _n . On dissolving a mixture of SrO and PbO of varying ratio one obtains at the same time mixed crystals of Na₂(Sr,Pb)P₂O₇ with a variable ratio of Sr,Pb and an ultraphosphate [(Sr,Pb)P₄O₁₁] _n with a constant ratio Sr,Pb=0,66,0,34. An interpretation of the formation of diphosphates from a melt of polyphosphates is attempted, using the present and previous observations.

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Mit 1 Abbildung

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Herrn Prof. Dr.E. Hayek zum 60. Geburtstag gewidmet.     

Cadmium

Ohne Zusammenfassung     

Spectrum of acetylene: 1650–1950 Å

A discontinuity in ¹³C-isotope shifts is used to fix the location of a diffuse 00 of gaseous ¹²C₂H₂ at 54 116 cm^?1. The shifts and analogy with a known band system of HCN suggest the assignment B? ¹B_u - X? ¹ Σ⁺_g for the new electronic transition.     

A hybrid Monte Carlo approach to molecular aggregation in a porous medium

A Monte Carlo simulation is used to study the segregation of liquid crystal molecules (short chains) in a heterogeneous matrix (of barrier concentration ) in an ordering field (E). Aggregation of molecules, pinned by the matrix barriers, is enhanced at lower temperature (T) and higher barrier concentrations via clusters of clustering growth. Variation of the radial distribution function with T and , rms displacement of molecules, and visual analysis of their distribution reveal that the size of the molecular aggregates is relatively larger and less dispersed at higher than that at a lower at T=0.2. The orientational molecular ordering is found to be lower at low temperature at higher . Molecules remain segregated at higher temperatures unless the porosity is reduced and the ordering field is increased considerably. Received 29 October 1999 and Received in final form 19 January 2000     

Imperfection of the Sm sublattice and valence instability in compounds based on SmB6

The magnetic susceptibility, electrical resistance, specific heat, and thermal expansion coefficient of SmB₆, Sm_0.8B₆, and Sm_1–x La_xB₆ (x=0.1 and 0.2) are measured in the temperature range T=4–300 K. The dispersion curves of the acoustic phonon branches in lanthanum-doped samples are studied. A combined analysis of the results confirms the existence of an activation gap in the electron density of states in both nonstoichiometric and lanthanum-doped compounds. The anomalies in the electronic component of the thermal expansion coefficient are associated to a considerable degree with the temperature variation of the valence and, like the magnetic susceptibility, reflect features of the f-electron excitation spectrum. It is found that lanthanum doping does not lead to significant changes in the anomalies in the phonon spectrum of SmB₆. It is established that the homogeneous intermediate-valent state of the samarium ion is fairly stable and is maintained when the perfection of the Sm sublattice is violated. Zh. éksp. Teor. Fiz. 115, 1024–1038 (March 1999)