Abstract: A green-blue to ultraviolet light-emitting optical device, e.g. a green-blue to ultraviolet emitting laser or a green-blue to ultraviolet emitting diode, comprising a green-blue to ultraviolet light emitting gallium nitride material on a base structure including a silicon carbide substrate, which preferably consists of 2H-SiC, 4H-SiC, or a-axis oriented 6H-SiC. The carrier mobility and the transparency of the silicon carbide substrate are optimized by the selection of orientation and polytype, thus enhancing device performance. The light-emitting diodes may incorporate a structural modification to increase the light output comprising a dielectric Bragg mirror beneath the LED structure, made of alternating layers of AlN, GaN, InN or their alloys. Methods for making such light-emitting diodes are provided, including a technique for defining individual devices by mesa etching which avoids possible damage to the active area during dicing.

Abstract: Garlic has been claimed to be effective against diseases, in the pathophysiology of which oxygen free radicals (OFRs) have been implicated. Effectiveness of garlic could be due to its ability to scavenge OFRs. However, its antioxidant activity is not known. We investigated the ability of allicin (active ingredient of garlic) contained in the commercial preparation Garlicin to scavenge hydroxyl radicals (·OH) using high pressure liquid chromatographic (HPLC) method. ·OH was generated by photolysis of H2O2 (1.25–10 μmoles/ml) with ultraviolet light and was trapped with salicylic acid which is hydroxylated to produce ·OH adduct products 2,3- and 2,5-dihydroxybenzoic acid (DHBA). H2O2 produced a concentration-dependent ·OH as estimated by ·OH adduct products 2,3-DHBA and 2,5-DHBA. Allicin equivalent in Garlicin (1.8, 3.6, 7.2, 14.4, 21.6, 28.8 and 36 μg) produced concentration-dependent decreases in the formation of 2,3-DHBA and 2,5-DHBA. The inhibition of formation of 2,3-DHBA and 2,5-DHBA with 1.8 μg/ml was 32.36% and 43.2% respectively while with 36.0 μg/ml the inhibition was approximately 94.0% and 90.0% respectively. The decrease in ·OH adduct products was due to scavenging of ·OH and not by scavenging of formed ·OH adduct products. Allicin prevented the lipid peroxidation of liver homogenate in a concentration-dependent manner. These results suggest that allicin scavenges ·OH and Garlicin has antioxidant activity.

Abstract: The output of a continuously pumped, Q-switched, Nd:YAG laser (10) is frequency converted to provide ultraviolet light (62) for forming vias (72, 74) in multi-layered targets (40). The parameters of the output pulses (62) are selected to facilitate substantially clean, simultaneous or sequential drilling or via formation in a wide variety of materials such as metals, organic dielectrics, and reinforcement materials having different thermal absorption characteristics in response to ultraviolet light. These parameters typically include at least two of the following criteria: high average power of greater than about 100 milliwatts measured over the beam spot area, a temporal pulse width shorter than about 100 nanoseconds, a spot diameter of less than about 50 microns, and a repetition rate of greater than about one kilohertz. The laser system (10) and method circumvent conventional depth of cut saturation limitations and can achieve an increased depth of cut per pulse in a target (40) formed of either single- or multi-layered material.

Abstract: Post-mortem neuropathological examination of five cases of Niemann-Pick disease type C revealed neurofibrillary tangles in many parts of the brain. Tangles were a consistent finding in the hippocampus, hypothalamus, substantia innominata, midbrain pons and medulla. Other regions of the brain in which tangles were present included neocortex, basal ganglia, thalamus, cerebellar cortex in one case, and dentate nucleus in another. The tangles were argyrophilic, fluoresced under ultraviolet light when stained with thioflavin S, and reacted strongly with antibody to tau protein. Some of the tangles could be immunostained for ubiquitin. Electron microscopy, performed in one of the cases, showed the tangles to consist of paired helical filaments ultrastructurally identical to those of Alzheimer's disease. The distribution of the tangles in the central nervous system as a whole and also within many individual neurons corresponded fairly closely with that of the abnormal storage material. Both the tangles and the storage material extended into, and distended, the proximal parts of many dendrites and axons. No A4/beta protein, either in the form of plaques or in the walls of blood vessels, was detected in any of the cases. Our findings suggest that neurofibrillary tangles are a common feature of Niemann-Pick disease type C and that their formation may be a reaction to the abnormal storage material.

Abstract: A population-based case-control study of cutaneous malignant melanoma (CMM) was conducted in 452 women with melanoma and 930 control subjects aged 25-59 years in five San Francisco Bay Area counties between 1981 and 1986. Women were interviewed in their homes with regard to history of sunlight exposure and sunburns during different periods in their lives, phenotypic and host characteristics, medical history, occupation, and demographic factors. Data were analyzed by the patients' histologic type of melanoma; 355 women were classified as having superficial spreading melanoma (SSM), 61 had nodular melanoma (NM), 13 had lentigo maligna melanoma, and 23 had other melanomas that could not be further classified upon histologic review by University of California dermatopathologists. Univariate results from analysis of factors related to sun exposure showed that the risk of all histologic types of CMM, SSM, and NM increased with increasing tendency of the subject to sunburn and with history of increased severity and/or frequency of sunburns up to age 12 years. Risk of all types of CMM and SSM also increased with increasing number of sunburns for all age groups and with lack of use of sunscreen. After adjustment for each other and for phenotypic factors, history of sunburn up to age 12 and lack of sunscreen use were the primary sun-related factors associated with an increased risk of all types of CMM and SSM, while tendency to sunburn when exposed to 1/2 hour of noontime sun and lack of use of sunscreen were related to NM. Although having frequent sunburns before age 12 and having severe sunburns before age 12 were both strongly associated with melanoma, having large numbers of sunburns during any time period from elementary school through age 30 years and having sunburns during the 10 years prior to diagnosis or interview were all associated with a doubling of risk for SSM after adjustment for other factors. These results suggest that the increased risk of melanoma related to sunburns is not confined to childhood sunburns. Maintenance of an all-year tan provided no protective effect against melanoma after adjustment for tendency to burn. No association was noted with use of fluorescent lights or exposure to sunlamps for all types of CMM, SSM, or NM.

Abstract: Gold surfaces have been found to be hydrophilic only after exhaustive preparation and with the ultimate care in sample preparation and treatment. The use of a combination of ultraviolet (UV) light and ozone has been described as a viable method of producing a clean, hydrophilic, gold surface. We have found that gold surfaces, which have been either stored in the laboratory after vacuum deposition or purchased as high purity standards, are oxidized by a combination of UV light and ozone generated from a mercury lamp. The samples were characterized with x‐ray photoelectron spectroscopy (XPS) and ion scattering spectroscopy (ISS) prior to and after exposure to UV/ozone in a stainless steel box in laboratory air. After the cleaning process gold surfaces were found by XPS to contain less carbon and to be enriched in oxygen. The O 1s on the cleaned surface, which was not present on the untreated surface, consisted of two peaks that are attributed to gold oxide and hydroxyl. The oxide layer was found to be 17±4 A thick by variable angle XPS depth profiling with an initial stoichiometry of Au2O3. The oxide was found to be stable to extended exposure to UHV and water and ethanol rinses. ISS compositional depth profiles confirmed the oxide layer thickness and that the hydrated surface layer is removed in the initial sputtering of the oxidized gold. Implications of these results related to the mechanism of self‐assembly of thiols on gold are discussed.

Abstract: The generation of free oxygen radicals is believed to play an important pathogenic role in the development of various disorders. More than other tissues, the skin is exposed to numerous environmental chemical and physical agents such as ultraviolet light causing oxidative stress. In the skin this results in several short- and long-term adverse effects such as erythema, edema, skin thickening, wrinkling, and an increased incidence of skin cancer or precursor lesions. However, accelerated cutaneous aging under the influence of ultraviolet light, usually termed photoaging, is only one of the harmful effects of continual oxygen radical production in the skin. Others include cutaneous inflammation, autoimmunological processes, keratinization disturbances, and vasculitis. Vitamin E is the major naturally occurring lipid-soluble non-enzymatic antioxidant protecting skin from the adverse effects of oxidative stress including photoaging. Its chemistry and its physiological function as a major antioxidative and anti-inflammatory agent, in particular with respect to its photoprotective, antiphotoaging properties, are described by summarizing animal studies, in vivo tests on human skin and biochemical in vitro investigations. The possible therapeutic use in different cutaneous disorders, and pharmacological and toxicological aspects are discussed. Many studies document that vitamin E occupies a central position as a highly efficient antioxidant, thereby providing possibilities to decrease the frequency and severity of pathological events in the skin. For this purpose increased efforts in developing appropriate systemic and local pharmacological preparations of vitamin E are required.

Abstract: In amphibian embryos, establishment of dorsal-ventral asymmetry is believed to involve dorsal-ventral differences in vegetally derived mesoderm-inducing signals and/or differences in the competence of animal hemisphere (ectodermal) cells to respond to these signals. Previous studies have shown that certain Wnt proteins can generate an ectopic dorsal axis when misexpressed, and that they do so by modifying the response of ectodermal cells to inducers. None of these Wnt proteins are expressed at an appropriate time to do so in vivo. In this study, we describe the isolation and characterization of a full length cDNA for the Xenopus Wnt gene, Xwnt-8b, whose biological activity and expression pattern suggest that it may be involved in establishment of the dorsoventral axis. Both maternal and zygotic Xwnt-8b transcripts undergo alternative splicing to generate mRNAs which encode two different forms of Xwnt-8b protein. During early cleavage stages Xwnt-8b transcripts are confined primarily to animal hemisphere blastomeres, while zygotically derived Xwnt-8b transcripts are restricted almost exclusively to a band of cells in the prospective forebrain of neurula and tailbud stage embryos. Ectopically expressed Xwnt-8b can completely rescue dorsal development of embryos ventralized by exposure to ultraviolet light, and can induce a complete secondary axis in wild-type embryos. Axis induction is observed only if Xwnt-8b is supplied prior to the onset of zygotic gene transcription. This biological activity, together with the presence of maternal Xwnt-8b transcripts in cells that will be induced to form the dorsal mesoderm, is consistent with the possibility that Xwnt-8b may be the endogenous agent that establishes asymmetry in the response of ectodermal cells to mesoderm-inducing signals, thereby initiating dorsal development.

Abstract: Bragg gratings with sidelobe levels 26 dB lower than the peak reflectivity have been fabricated in standard telecommunication optical fibres by exposure to ultraviolet light through a phase mask with a locally varying diffraction efficiency This represents a reduction of 14 dB in the sidelobe levels compared to uniform gratings with the same bandwidth and reflectivity

Abstract: We have conducted a detailed study of the thermal stability of Bragg gratings written in hydrogen‐loaded and unloaded germanium‐doped optical fiber. Interference of either continuous‐wave or pulsed ultraviolet light was used to induce the index modulation gratings. Some gratings were kept at room temperature and others were annealed at fixed temperatures for 10–20 h. For temperatures between room temperature and 350 °C, gratings in the hydrogen‐loaded fiber showed significantly greater decay than those in the unloaded counterpart. The ultraviolet‐induced index modulation in hydrogen‐loaded fiber was reduced by 40% after 10 h at 176 °C, whereas it was reduced by only 5% in unloaded fiber under the same conditions. The annealing behavior of gratings written using the pulsed source was identical to that of gratings written with the continuous‐wave source, and the thermal stability of gratings in hydrogen‐loaded fiber did not depend on the magnitude of the index modulation. We also observed that the annealing of ultraviolet‐induced OH absorption in the hydrogen‐loaded fiber was not correlated with the grating decay. Our annealing results show that the species responsible for the index change in the hydrogen‐loaded fiber are less stable than those in the unloaded fiber.

Abstract: Tumor suppressor gene CDKN2 (also called MTS1, CDK4I and p16INK4) is located in 9p21 and deleted homozygously in a high percentage of tumor cell lines. We have examined the sequence of CDKN2 in 154 tumor cell lines that are not homozygously deleted for CDKN2. Overall, 18% (27/154) of the cell lines carried mutations in CDKN2. These mutations were found in cell lines derived from melanoma, bladder, lung and prostate cancers, as well as sarcomas of various origin. The spectrum of the CDKN2 mutations found in melanoma cell lines indicated a major role for ultraviolet light in generating the mutations, suggesting the mutations occurred in vivo. The frequency of loss of heterozygosity in 9p21 in this set of lines is only slightly higher than the background rate of aneuploidy, suggesting that a second 9p21 tumor suppressor gene, if it exists, must lie near CDKN2.

Abstract: Purpose. Heme oxygenase-1 (HO-1) is a stress protein induced up to 100-fold within a few hours after exposure to oxidative stress, and it has been shown to counteract oxidative injury induced by ultraviolet light or free radicals. The current study was undertaken to determine whether the HO-1 gene can be introduced into adult rabbit ocular tissues by microinjection of a recombinant replication-deficient adenovirus human HO-1 cDNA (Adv-HHO). Methods. Human HO-1 gene was used for transfection studies to differentiate endogenous from transfected HO. The purified Adv-HHO construct (10 8 pfu/ml) was mixed with lipofectamine and microinjected into the anterior chamber, vitreous cavity, and subretinal space of New Zealand rabbit eyes. After 2 weeks, total RNA was extracted from different ocular tissues, reverse transcription-polymerase chain reaction was performed using specific human HO-1 primers, and amplification products were subjected to Southern hybridization. Results. Transfection with the Adv-HHO construct into rabbit corneal epithelial cells in culture resulted in a functional expression of the human HO-1 gene ; the human HO-1 mRNA was detected, and enzyme activity increased threefold. Human HO-1 mRNA was detected in the retina after microinjection of the Adv-HHO construct into the subretinal space. Microinjection into the vitreous resulted in HO-1 mRNA expression in the corneal endothelium, iris, lens, and retina ; after intracameral injection of the Adv-HHO construct, human HO-1 mRNA was detected in corneal epithelium and endothelium, ciliary body, lens, and iris. Regardless of the injection site, transfected human HO-1 mRNA was undetectable in tissues outside the eye, that is, brain, liver, and kidney. Conclusions. These results demonstrated a tissue-selective functional transfer of the human HO-1 gene into rabbit ocular tissues in vivo. This technique may be a promising means for delivering HO-1 gene in vivo as a protective mechanism against oxidative stress that contributes to the pathogenesis of ocular diseases such as cataract, light-induced injury, age-related macular degeneration, and diabetic retinopathy. Invest Ophthalmol Vis Sci. 1995 ;36 :2202-2210.

Abstract: One of the major obstacles to pulmonary-directed gene therapy using adenoviral vectors is the induction of inflammation. We investigated whether the adenoviral particles that constitute the initial inoculum can serve as an inflammatory stimulus, independent of their ability to express genes that they contain. Viral particles were prepared that are defective in gene expression by (i) isolating particles that have incomplete genomes by selecting those that have buoyant densities on CsCl density gradients lighter than complete viruses; and (ii) cross-linking viral DNA by exposure to ultraviolet light in the presence of 8-methoxypsoralen. The defective particles retained their icosahedral appearance when viewed by electron microscopy but lost their plaque-forming ability on 293 cells. High doses of intact, incomplete, or inactivated viral particles were instilled intratracheally into CBA/J mice, and after 6 days the amount of inflammation was quantified by counting inflammatory cells contained within...

Abstract: In this research, the effectiveness of various blending and sonication techniques were investigated for extracting particle-associated coliforms from secondary effluent samples. The amount of shielding from ultraviolet disinfection afforded these coliforms by the particulates was then assessed. It was found that blending samples for 1.5 minutes at 19 000 rpm at 4°C in a mixture of chemicals (resulting in concentrations of 10 -6 M Zwittergent 3-12, 10 -3 M EGTA, 0.01 M Tris buffer, 0.1% peptone, and pH 7) resulted in the greatest recovery of particle-associated coliform, as detected by the multiple tube fermentation (MTF) test. Fragmentation of large flocs during homogenization, as evidenced by the change in particle size distribution, was most likely the responsible mechanism. Sonication proved ineffective. It was found that particle association and shielding of coliforms significantly affect accurate measurements of coliform density in secondary effluent using the standard MTF test and that significantly more coliforms may be present in disinfected secondary effluents than is indicated by the standard enumeration procedure.

Abstract: The spectral properties of Tb(III) complexes with a series of 4-substituted analogues of dipicolinic acid (2,6 pyridinedicarboxylic acid) were compared. Analogues in which the 4-substituted was -H, -OH, -Cl, -Br, -NH{sub 2}, or -NHAc all sensitized emission from bound terbium ions when excited with ultraviolet light. Molar extinction coefficients of the complexes at the wavelengths of maximum absorbance were in the range (2.2 x 10{sup 3} to 8.3 x 10{sup 3}) M{sup {minus}1} cm{sup {minus}1} with magnitudes in the following order: NHAc > NH{sub 2} > OH > H > Br > Cl. When excitation spectra of Tb(III) complexes were measured under identical conditions for each ligand, the maximum Tb(III) emission intensities were in the following order: NH{sub 2} > NHAc > OH > H > Cl {approximately} Br. Measurements of Tb(III) emission decay kinetics revealed lifetimes in the range 1.0-2.0 ms. Relative quantum yields for energy transfer were ordered as follows: NH{sub 2} > OH > NHAc > Cl > H {approximately} Br. Energy transfer efficiency was not enhanced when Br was substituted for Cl at the 4-position, consistent with energy transfer from excited singlet, rather than triplet states. The efficient sensitization of Tb(III) emission by the analogues withmore » nitrogen at the 4-position suggests that this class of compounds will be most useful for developing millisecond luminescence probes for bioanalytical studies.« less

Abstract: The estimation of age of lake sturgeon Acipenser fulvescens by counting annuli in transverse sections of pectoral fin rays is validated through two methods: capture–recapture and examination of annuli laid down after injection of an oxytetracycline (OTC) marker. At first capture of each individual, the first ray of the right pectoral fin was removed. At recapture, 1–3 years later, the first ray of the left pectoral fin was removed. Differences between counts of annuli in rays collected at capture and at recapture were the same as the number of years that individual had been at large. At first capture lake sturgeons ranged in age and size from 4 years old and 43 cm fork length (FL) to 34 years and 115 cm FL. At recapture, they ranged from 6 years and 45 cm FL to 36 years and 122 cm FL. Fin ray sections of recaptured individuals previously injected with an OTC marker showed a discrete fluorescent band under ultraviolet light. The number of annuli outside this band corresponded to the number of year...

Abstract: A cosmetic composition according to the present invention incorporates a new combination of ingredients particularly designed to provide significant protection of the skin from several damaging components of environmental pollution, while also providing significant protection against moisture loss and damage due to free radical activity and ultraviolet light, both UV-A and UV-B, and controlling oil In general, a cosmetic composition according to the present invention comprises: water, and emulsified and dispersed in the water: (1) an anti-pollution complex comprising propylene glycol, hydrolyzed wheat protein, mannitol, glycogen, yeast extract, ginseng extract, linden extract, calcium pantothenate, horse chestnut extract, and biotin; (2) a micellar complex comprising: phospholipids, glycosphingolipids, panthenol, Crataegus extract, cholesterol, and sodium hyaluronate; (3) an anti-free radical complex comprising melanin, a short-chain fatty acid ester of tocopherol, a long-chain fatty acid ester of retinol, and a long-chain fatty acid ester of ascorbic acid; and (4) a sunscreen Other cosmetic components, such as aloe extract, matricaria extract, apricot kernel extract, garden balsam leaf extract, hydrolyzed soy protein, and horsetail extract, and ancillary components can also be used

Abstract: Photochemotherapy with 8-methoxypsoralen and long-wave ultraviolet light (PUVA) has become a useful alternative in dermatologic therapy PUVA therapy has been successfully used in the treatment of severe psoriasis and cutaneous lichen planus The aim of this investigation was to use PUVA in the treatment of oral lichen planus (OLP) Eighteen patients with long-standing, bilateral, and severe OLP of the buccal mucosa participated in the investigation A dose of 06 mg/kg 8-methoxypsoralen was administered orally 2 hours before long-wave ultraviolet light irradiation was done The patients were randomly assigned to treatment of the left or right side of the buccal mucosa The irradiation therapy was given 12 times at intervals of 2 to 3 days, and the patients received a total average dosage of 165 J/cm2 The results showed that 13 treated sites compared with six control sites responded significantly favorable to PUVA therapy Two patients dropped out because of side effects that were similar to those seen after whole-body irradiation PUVA treatment The follow up times was 12 months The conclusion of this study is that PUVA seems to be effective in the treatment of OLP and should be considered in severe cases of OLP

Abstract: 8-Methoxypsoralen in combination with long wavelength ultraviolet light is employed for the treatment of several cutaneous disorders, such as psoriasis, vitiligo and mycosis fungoides. It is common to attribute the efficacy of the photochemotherapy to the formation of psoralen DNA photoadducts. Thus, the main research effort has been directed towards the elucidation of nucleic acid photochemistry and related subsequent events (mutagenicity, toxicity). However, psoralens have been shown to undergo photoaddition reactions with other cellular components. In this review the status of psoralen-DNA photobiology is briefly summarized. The main focus, however, is on a survey of psoralen photochemical modification of proteins and the ways by which these additional photobiological events can impact the antigenicity and potentially immunogenicity of treated cells. Some preliminary results show the extent of psoralen-amino acid photoadduct formation and their impact on enzymatic processing.

Abstract: Two mutants affected in lipid metabolism of Chlamydomonas reinhardtii were isolated by treating cells with ultraviolet light. Both mutants showed high chlorophyll fluorescent yields, as compared with parents, and were designated as hf-2 and hf-9 (for high fluorescence), hf-2 was shown to be defective in the synthesis of a chloroplast-specific lipid, sulfoquinovosyl diacylglycerol. hf-9 was shown to be defective in desaturation at the ω6 position of fatty acids of monogalactosyl diacylglycerol, digalactosyl diacylglycerol, sulfoquinovosyl diacylglycerol and phosphatidylglycerol. The mutants exhibited alterations in photosynthetic activity and chloroplast ultrastructure.

Abstract: For many years, it has been suggested that exposure to sunlight, particularly its ultraviolet component, may be associated with an increased risk of senile cataract. This paper adresses 1) the physical and geographic variables that affect the entry of ultraviolet light in the eye; 2) the epidemiologic evidence that associates cataract with ultraviolet light exposure; and 3) the effectiveness of personal barrier protection (i.e. sunglasses and hats) in reducing ocular exposure to ultraviolet light. The epidemiologic evidence is drawn from studies in Australia, China, Tibet, and the United States. The U.S evidence consists of data from the Maryland Watermen study and analyses of cataract surgery under the Medicare program which provides health insurance for nearly all Americans age 65 and over (30 million) and pays for 85% of the 1.3 million cataract extractions performed annually in the U.S. Analysis of the Medicard data shown that, after controlling for age, sex, and race, and income of the population and also controlling for supply of ophthalmologists, optometrists, price of surgery and local practice costs, the strongest predictor of cataract surgery likelihood in a Medicare benificiary is the person's latitude of residence. Latitude correlates directly with the UV-B content of sunlight, because the incident angle of the sun determines the atmospheric penetration of ultraviolet radiation. Data suggest that the probability of cataract surgery in the U.S. increases by 3% for each 1 degree decrease (i.e. more Southerly) in latitude.