Search results for " rays"

Different sensitivity of carp (Cyprinus carpio) and rainbow trout (Oncorhynchus mykiss) to the immunomodulatory effects of UVB irradiation.

2006

Abstract In order to study the sensitivity of two fish species, carp (Cyprinus carpio) and rainbow trout (Oncorhynchus mykiss), to the immunomodulatory effects of ultraviolet B (UVB) radiation, the fish were exposed to a single UVB dose of 50, 250, 500 or 1000 mJ cm−2. These species represent different phylogenetic groups of fish, and they differ also in their behaviour inhabitating often dark and turbid (carp) or clear and transparent waters (salmonids). Immune responses were studied on day 1 post-irradiation. Unexposed fish, and fish exposed to radiation depleted of UV wavelengths served as controls. UVB irradiation markedly enhanced the blood respiratory burst and cytotoxic activity in c…

Long-term UVB irradiation affects the immune functions of carp (Cyprinus carpio) and rainbow trout (Oncorhynchus mykiss).

2009

The effects of long-term, low-dose ultraviolet B (UVB) radiation on immune functions of two fish species representing different taxonomic groups, carp (Cyprinus carpio) and rainbow trout (Oncorhynchus mykiss), were assessed in this study. The fish were exposed to 7, 20 or 60 mJ cm(-2) UVB three times per week, for 6 weeks. In carp, UVB exposure affected the respiratory burst activity of blood and head kidney phagocytes, differential blood leukocyte counts and blood chemistry. Phytohemagglutinin (PHA)-stimulated in vitro proliferation responses of blood and head kidney lymphocytes, however, remained unchanged. Rainbow trout tolerated the irradiations with fewer alterations, but significant c…

A Comparison of the Histodynamics of Sebaceous Glands and Epidermis in Man: a Microanatomic and Morphometric Study

1974

Photoactivation of Anticancer Ru Complexes in Deep Tissue: How Deep Can We Go?

2017

Activation of anticancer therapeutics such as ruthenium (Ru) complexes is currently a topic of intense investigation. The success of phototherapy relies on photoactivation of therapeutics after the light passes through skin and tissue. In this paper, the photoactivation of anticancer Ru complexes with 671-nm red light through tissue of different thicknesses was studied. Four photoactivatable Ru complexes with different absorption wavelengths were synthesized. Two of them (Ru3 and Ru4) were responsive to wavelengths in the “therapeutic window” (650–900 nm) and could be activated using 671-nm red light after passing through tissue up to 16-mm-thick. The other two (Ru1 and Ru2) could not be ac…

Differential regulation of the clusterin gene by Ha-ras and c-myc oncogenes and during apoptosis

1998

Clusterin (ApoJ) is an extracellular glycoprotein expressed during processes of tissue differentiation and regression that involve programmed cell death (apoptosis). Increased clusterin expression has also been found in tumors, however, the mechanism underlying this induction is not known. Apoptotic processes in tumors could be responsible for clusterin gene activation. Alternatively, oncogenic mutations could modulate signal transduction, thereby inducing the gene. We examined the response of the rat clusterin gene to two oncogenes, Ha-ras and c-myc, in transfected Rat1 fibroblasts. While c-myc overexpression did not modify clusterin gene activity, the Ha-ras oncogene produced a seven to t…

Synthesis, spectroscopic studies and biological evaluation of acridine derivatives: The role of aggregation on the photodynamic efficiency.

2018

Two new photoactive compounds (1 and 2) derived from the 9-amidoacridine chromophore have been synthesized and fully characterized. Their abilities to produce singlet oxygen upon irradiation have been compared. The synthesized compounds show very different self-aggregating properties since only 1 present a strong tendency to aggregate in water. Biological assays were conducted with two cell types: hepatoma cells (Hep3B) and human umbilical vein endothelial cells (HUVEC). Photodynamic therapy (PDT) studies carried out with Hep3B cells showed that non-aggregating compound 2 showed photoxicity, ascribed to the production of singlet oxygen, being aggregating compound 1 photochemically inactive.…

Aluminium nitrate ceramics: a potential UV dosemeter material.

2002

The ceramic material AlN-Y 2 O 3 is proposed as a potential ultraviolet radiation (UVR) dosemeter using optically stimulated luminescence (OSL) and thermally stimulated luminescence (TL). Experimental studies have shown that AlN ceramics exhibit attractive characteristics suitable for practical UV dosimetry applications. The features are: (1) the spectral sensitivity covers the 200-350 nm range, in the UV-B region it is similar to that of human skin; (2) the angular dependence of the incident radiation follows the cosine law; (3) high yields of both UVR-induced OSL and TL signals compared to those of Al 2 O 3 :C; and (4) a large dynamic range TL signal (5 orders of magnitude). Although ther…

Sensitivity of the Cherenkov Telescope Array to spectral signatures of hadronic PeVatrons with application to Galactic Supernova Remnants

2023

The local Cosmic Ray (CR) energy spectrum exhibits a spectral softening at energies around 3~PeV. Sources which are capable of accelerating hadrons to such energies are called hadronic PeVatrons. However, hadronic PeVatrons have not yet been firmly identified within the Galaxy. Several source classes, including Galactic Supernova Remnants (SNRs), have been proposed as PeVatron candidates. The potential to search for hadronic PeVatrons with the Cherenkov Telescope Array (CTA) is assessed. The focus is on the usage of very high energy $\gamma$-ray spectral signatures for the identification of PeVatrons. Assuming that SNRs can accelerate CRs up to knee energies, the number of Galactic SNRs whi…

Spectral attenuation of solar ultraviolet radiation in humic lakes in Central Finland

2003

The attenuation of solar ultraviolet (UV) radiation in five lakes in Central Finland was evaluated through field measurements and/or by determining the optical properties of the lake water during summer 1999. Spectral UV irradiance in the air and at several depths underwater was measured in three lakes (Lake Palosjärvi, Konnevesi, and Jyväsjärvi) with dissolved organic carbon (DOC) ranging from 4.9 to 8.7 mg l(-1) and chlorophyll a ranging from 1.6 to 16 g l(-1). According to the field measurements, 99% of the UV-B radiation was attenuated in approximately a half meter water column in the clearest lake. In the UV-A region at 380 nm, the corresponding attenuation occurred in the upper one me…

TFIIH Operates through an Expanded Proximal Promoter To Fine-Tune c-myc Expression

2004

A continuous stream of activating and repressing signals is processed by the transcription complex paused at the promoter of the c-myc proto-oncogene. The general transcription factor IIH (TFIIH) is held at promoters prior to promoter escape and so is well situated to channel the input of activators and repressors to modulate c-myc expression. We have compared cells expressing only a mutated p89 (xeroderma pigmentosum complementation group B [XPB]), the largest TFIIH subunit, with the same cells functionally complemented with the wild-type protein (XPB/wt-p89). Here, we show structural, compositional, and functional differences in transcription complexes between XPB and XPB/wt-89 cells at t…