Irradiation-induced Effects Research Articles

Displacement damage analysis and modified electrical equivalent circuit for electron and photon-irradiated silicon solar cells

Solar modules and arrays are the conventional energy resources of space satellites. Outside the earth's atmosphere, solar panels experience abnormal radiation environments and because of incident particles, photovoltaic (PV) parameters degrade. This article tries to analyze the electrical performance of electron and photon-irradiated mono-crystalline silicon (mono-Si) solar cells. PV cells are irradiated by mono-energetic electrons and poly-energetic photons and immediately characterized after the irradiation. The mean degradation of the maximum power (Pmax) of silicon solar cells is presented and correlated using the displacement damage dose (Dd) methodology. This method simplifies evaluation of cell performance in space radiation environments and produces a single characteristic curve for Pmax degradation. Furthermore, complete analysis of the results revealed that the open-circuit voltage (Voc) and the filling factor of mono-Si cells did not significantly change during the irradiation and were independent of the radiation type and fluence. Moreover, a new technique is developed that adapts the irradiation-induced effects in a single-cell equivalent electrical circuit and adjusts its elements. The “modified circuit” is capable of modeling the “radiation damage” in the electrical behavior of mono-Si solar cells and simplifies the designing of the compensation circuits.

Irradiation-induced effects of proton irradiation on zirconium carbides with different stoichiometries

Zirconium carbide (ZrC) is being considered for utilization in deep burn TRISO fuel particles for high-temperature, gas-cooled reactors. Zirconium carbide has a cubic B1 type crystal structure along with a very high melting point (3420°C), exceptional hardness and good thermal and electrical conductivities. Understanding the ZrC irradiation response is crucial for establishing ZrC as an alternative component in TRISO fuel. Until now, very few studies on irradiation effects on ZrC have been released and fundamental aspects of defect evolution and kinetics are not well understood although some atomistic simulations and phenomenological studies have been performed. This work was carried out to understand the damage evolution in float-zone refined ZrC with different stoichiometries. Proton irradiations at 800°C up to doses of 3dpa were performed on ZrCx (where x ranges from 0.9 to 1.2) to investigate the damage evolution. The irradiation-induced defects, such as density of dislocation loops, at different stoichiometries and doses which were characterized by transmission electron microscopy (TEM) is presented and discussed.

A new method to simulate the micro-thermo-mechanical behaviors evolution in dispersion nuclear fuel elements

The large-deformation constitutive relations and stress update algorithms in a co-rotational framework are formulated respectively for the fuel particles, the matrix and cladding in dispersion nuclear fuel elements undergoing irradiation, with the main irradiation-induced effects within them considered. Their specific consistent tangent stiffness moduli are also developed. Correspondingly, the user subroutines UMAT have been programmed for definition of their mechanical constitutive relations. Besides, the user subroutines UMATHT have been written to define their thermal constitutive relations, in which degradation of the thermal conductivity of fuel particles are involved. An efficient method is established for modeling the irradiation-induced micro-thermo-mechanical behaviors evolution in dispersion nuclear fuel elements. The developed methodology is validated with the simulation results of the thermo-mechanical behaviors in fuel elements under an assumed irradiation condition. This study lays a foundation for optimal design of dispersion fuel elements.

Heavy ion-related bystander effects

Space radiation is composed of high-energy protons and heavier charged particles, which is distinct from common terrestrial forms of radiation. These particles can damage both shielding materials and biological systems. Although the fluence of space radiation is typically low, the effects are cumulative and may pose great risk during human exploration beyond low Earth orbit. In recent years, radiation-induced non-targeted effects, in which extranuclear and extracellular events may also contribute to the biological consequences of exposure to low doses of radiation, have been demonstrated to increase the detrimental effects caused by radiation in some in vitro and in vivo systems. Here, studies on non-targeted effects caused by radiation are summarized, with special emphasis on heavy ion-related bystander effects and cytoplasmic irradiation-induced effects.

A structure–property correlation study of neutron irradiation induced damage in EU batch of ODS Eurofer97 steel

Within the framework of the European Fusion Development Agreement (EFDA), an EU batch of oxide-dispersion-strengthened (ODS) Eurofer97 steel samples have been irradiated with neutrons to nominal dose levels of 1 and 3 displacements per atom (dpa) in the High Flux Reactor (HFR) located in Petten to investigate irradiation induced changes in the microstructure and mechanical properties. The results of the irradiation-induced effects on the mechanical properties of this steel are published by Luzginova et al. (2011) [18]. In this paper, post-irradiation examination (PIE) by Transmission Electron Microscopy is performed on the material irradiated at 300°C to investigate irradiation-induced microstructure dependence on the neutron irradiation dose and relate it to the observed mechanical properties. The results of this study revealed a presence of a high density of black dot damage and self-interstitial atom (SIA) dislocation loops in the microstructure after neutron irradiation to both 1 and 3dpa dose levels. No dissolution of the ODS particles due to irradiation was observed. These results are discussed in relation with the irradiation hardening and shift in ductile to brittle transition temperature (DBTT) observed in this alloy at the above irradiation conditions.

In Situ $I$ –$V$ Measurements of an Ultraviolet Enhanced $\hbox{ZnS:TiO}_{2}/\hbox{n-Si}$ Quantum Dot Heterojunction Photodiode Under 120 MeV $\hbox{Au}^{9+}$ Ions

This paper reports the development of a <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\hbox{ZnS:TiO}_{2}/\break \hbox{n-Si}$</tex></formula> heterojunction photodiode structure by deposition of colloidal <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\hbox{ZnS:TiO}_{2}$</tex></formula> quantum dots (QDs) on the n-Si substrate. To study the diode performance under harsh radiation atmospheres, in situ dark <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$I$</tex></formula> – <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$V$</tex> </formula> characteristics of the <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\hbox{ZnS:TiO}_{2}/\hbox{n-Si}$</tex></formula> photodiode have been studied under the irradiation of 120 MeV <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\hbox{Au}^{9+}$ </tex></formula> ions with an incremental increase in fluences from <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\hbox{3} \times \hbox{10}^{11}$</tex></formula> to <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\hbox{1} \times \hbox{10}^{13} \ \hbox{ions/cm}^{2}$</tex></formula> . It shows the increase in rectification behavior with the increase in irradiation fluences caused by interface smoothening and interface defect annealing at higher fluences. X-ray diffraction patterns and TEM analysis also show the increased crystallinity of <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$ \hbox{ZnS:TiO}_{2}$</tex></formula> QDs of size approximately 2–5 nm, whereas photoluminescence spectra show the reduction of defects. These results are in support of the irradiation-induced effects in in situ <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$I$</tex></formula> – <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$V$</tex></formula> measurements. The studies are also made for ultraviolet light of 376 nm wavelength (laser power 50 mW) and visible light of power 60 W for pristine and irradiated (at fluence <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\hbox{1} \times \hbox{10}^{13} \ \hbox{ions/cm}^{2}$</tex></formula> ) <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\hbox{ZnS:TiO}_{2}/\hbox{n-Si}$</tex></formula> heterojunction photodiodes.

Photoprotective and immunoregulatory capacity of ginsenoside Rg1 in chronic ultraviolet B-irradiated BALB/c mouse skin

The aim of this study was to investigate the photoprotective and immunoregulatory capacities of ginsenoside Rg1 in skin irradiated by chronic ultraviolet B (UVB) and to verify the potential mechanisms of action. BALB/c mice were pretreated with a topical application of ginsenoside Rg1 and irradiated with different doses of UVB daily for 30 consecutive days. Following chronic UVB irradiation, there were significant pathological changes in the skin of the BALB/c mice, including hyperkeratosis, acanthosis, sponge-like edematization and sunburn occurring in the epidermis, while edema, telangiectasis and inflammatory cell infiltration were observed in the papillary layer of the dermis. Treatment with ginsenoside Rg1 was able to reduce such changes induced by UVB irradiation. The number of p53 protein-positive stained cells following UVB irradiation was also observed by immunohistochemical analysis. Ginsenoside Rg1 downregulated the p53 protein expression induced by UVB irradiation, leading to reductions of 69.50, 23.53 and 12.93% at doses of 30, 60 and 120 mJ/cm2, respectively. Using reverse transcription polymerase chain reaction (RT-PCR), reductions in the levels of interferon (IFN)-γ mRNA expression were detected following UVB exposure; reductions of 19.6, 36.3 and 39.6% were observed following UVB irradiation at doses of 30, 60 and 120 mJ/cm2, respectively. The interleukin (IL)-10 mRNA expression levels increased by 40.1, 71.0 and 89.4% and the tumor necrosis factor (TNF)-α mRNA expression levels increased by 36.4, 18.4 and 8.6% following UVB irradiation at doses of 30, 60 and 120 mJ/cm2, respectively. However, pretreatment with ginsenoside Rg1 was observed to markedly attenuate the UVB irradiation-induced effects on the mRNA expression levels of the three cytokines. The topical application of ginsenoside Rg1 was able to protect the irradiated skin from UVB injury and reduce UVB-induced p53 protein expression. Ginsenoside Rg1 also demonstrated a potential regulatory effect on the UVB-induced local expression of the mRNA of the cytokines IFN-γ, IL-10 and TNF-α, which may be important in its immunoregulatory and inflammatory mechanisms.

Modulating Roles of Amiloride in Irradiation-Induced Antiproliferative Effects in Glioblastoma Multiforme Cells Involving Akt Phosphorylation and the Alternative Splicing of Apoptotic Genes

Apoptosis is a key mechanism for enhanced cellular radiosensitivity in radiation therapy. Studies suggest that Akt signaling may play a role in apoptosis and radioresistance. This study evaluates the possible modulating role of amiloride, an antihypertensive agent with a modulating effect to alternative splicing for regulating apoptosis, in the antiproliferative effects induced by ionizing radiation (IR) in glioblastoma multiforme (GBM) 8401 cells. Analysis of cell viability showed that amiloride treatment significantly inhibited cell proliferation in irradiated GBM8401 cells (p<0.05) in a time-dependent manner, especially in cells treated with amiloride with IR post-treatment. In comparison with GBM8401 cells treated with amiloride alone, with GBM8401 cells treated with IR alone, and with human embryonic lung fibroblast control cells (HEL 299), GBM8401 cells treated with IR combined with amiloride showed increased overexpression of phosphorylated Akt, regardless of whether IR treatment was performed before or after amiloride administration. The alternative splicing pattern of apoptotic protease-activating factor-1 (APAF1) in cells treated with amiloride alone, IR alone, and combined amiloride-IR treatments showed more consistent cell proliferation compared to that in other apoptosis-related genes such as baculoviral IAP repeat containing 5 (BIRC5), Bcl-X, and homeodomain interacting protein kinase-3 (HIPK3). In GBM8401 cells treated with amiloride with IR post-treatment, the ratio of prosurvival (-XL,-LC) to proapoptotic (-LN,-S) splice variants of APAF1 was lower than that seen in cells treated with amiloride with IR pretreatment, suggesting that proapoptotic splice variants of APAF1 (APAF1-LN,-S) were higher in the glioblastoma cells treated with amiloride with IR post-treatment, as compared to glioblastoma cells and fibroblast control cells that had received other treatments. Together, these results suggest that amiloride modulates cell radiosensitivity involving the Akt phosphorylation and the alternative splicing of APAF1, especially for the cells treated with amiloride with IR post-treatment. Therefore, amiloride may improve the effectiveness of radiation therapy for GBMs.

Study of gamma irradiation-induced effects on organic pollutants and suspended solids in coking wastewater

To investigate the effects of gamma irradiation on coking wastewater treatment, a preliminary study using different doses of gamma radiation (1, 3, 5 and 7 kGy) on coking wastewater samples was carried out. The pH parameter, chemical oxygen demand (COD), total suspended solids (TSS) and total organic carbon (TOC) of the coking wastewater samples were determined before and after irradiation. Results showed that gamma irradiation was effective for removing organic contaminants and suspended solids particles. The values of COD, TSS, TOC and pH decreased with the increasing of absorbed doses, after gamma irradiation. The removal rate of TSS and TOC is 81.43 and 95.22% at the absorbed doses of 7 kGy, respectively. It indicates that gamma irradiation offers an alternative method for coking wastewater treatment that may have extra benefit of improving the water quality.

Tailoring of magnetism in Pt/Co/Pt ultrathin films by ion irradiation

Magnetization orientation in Ga${}^{+}$-irradiated Pt/Co(${d}_{\mathrm{Co}}$)/Pt ultrathin films can be changed in a controlled way by adjusting the ion fluence, $F$. Two-dimensional (${d}_{\mathrm{Co}}$, $F$) diagrams of magnetic and magneto-optical properties have been derived. Distinct out-of-plane magnetic anisotropy states with enhanced magneto-optical effects were evidenced for specific (${d}_{\mathrm{Co}}$, $F$) values. This rich behavior originates from two competing mechanisms: intermixing of Co and Pt atoms at the interfaces and the formation of ordered CoPt alloy phases with high magnetic anisotropy. The irradiation-induced effects open novel routes for both tailoring thin-film magnetic and magneto-optical properties and patterning of magnetic nanostructures.

Atom probe tomography: from physical metallurgy towards microelectronics

Abstract Atom probe tomography (APT) is the only approach able to map out the 3D distribution of chemical species in a material at the atomic-scale. It has been applied to a number of issues in physical metallurgy including precipitation, segregation of impurities to lattice defects, ordering, magnetic multilayers. The implementation of ultrafast laser pulses instead of high-voltage pulses to field evaporate surface atoms has been a major breakthrough as this opened APT to semi-conductors or oxides that are key materials in microelectronics. This article reviews some of the more recent salient findings in physical metallurgy and microelectronics materials using APT. Special attention is paid to the role played by APT in the elucidation of irradiation-induced segregation effects. The following section deals with the segregation of dopants to crystal defects in silicon, a phenomenon that has a considerable influence on properties and performance of latest generation nano-transistors and devices.

Ion and electron irradiation-induced effects in nanostructured materials

A common misconception is that the irradiation of solids with energetic electrons and ions has exclusively detrimental effects on the properties of target materials. In addition to the well-known cases of doping of bulk semiconductors and ion beam nitriding of steels, recent experiments show that irradiation can also have beneficial effects on nanostructured systems. Electron or ion beams may serve as tools to synthesize nanoclusters and nanowires, change their morphology in a controllable manner, and tailor their mechanical, electronic, and even magnetic properties. Harnessing irradiation as a tool for modifying material properties at the nanoscale requires having the full microscopic picture of defect production and annealing in nanotargets. In this article, we review recent progress in the understanding of effects of irradiation on various zero-dimensional and one-dimensional nanoscale systems, such as semiconductor and metal nanoclusters and nanowires, nanotubes, and fullerenes. We also consider the two-dimensional nanosystem graphene due to its similarity with carbon nanotubes. We dwell on both theoretical and experimental results and discuss at length not only the physics behind irradiation effects in nanostructures but also the technical applicability of irradiation for the engineering of nanosystems.

Absence of 633-nm laser irradiation-induced effects on glucose phosphorylation by hexokinase

In a paper by Amat et al. (Modification of the intrinsic fluorescence and biochemical behavior of adenosine triphosphate ATP after irradiation with visible and near-infrared laser light, J. Photochem. Photobiol. B 81 (2005) 26–32) it was shown that the conversion of glucose to glucose-6-phosphate by hexokinase in vitro was accelerated when ATP, which supplies the reaction with energy, was priorly irradiated at non-resonant optical frequencies (NROF, i.e., 655 and 830 nm). Correspondingly, the authors postulated that NROF may lower the energy barrier for the dephosphorylation of ATP’s terminal phosphate and thus accelerate the reaction rate through a more expeditious energy delivery. Next to the established photobiostimulatory influence of visible light on cells, which is mediated by cytochrome c oxidase through resonant effects of light, Amat et al. posited an interesting theory with which the same processes could be induced through non-resonant effects. To investigate the effects of NROF with respect to the hexokinase reaction in greater detail, the reaction rates were measured spectrofluorometrically after 633-nm laser irradiation of ATP, the ATP-Mg complex, hexokinase, and the entire reaction mixture at room temperature (22 °C) and at the optimal reaction temperature (30 °C). No differences in reaction rates between the NROF-irradiated and control groups were found at either temperature. The hypothesis that NROF enhances in vitro hexokinase activity by lowering the activation energy for the dephosphorylation of ATP’s terminal phosphate by hexokinase was therefore disproven. Consequently, it is questionable, albeit not unequivocal, that NROF exerts an effect on other ATP-driven reactions in cell metabolic pathways through a direct impact on ATP.

Exoresection and endoresection for uveal melanoma

Surgical resection of uveal melanomas is an alternative eye-salvaging approach to the more commonly used irradiation techniques. There are two surgical resection techniques: Transscleral resection or “Exoresection” via a partial lamellar sclerouvectomy and “Endoresection” via a pars plana vitrectomy. While exoresection is more applicable to anteriorly located tumors with ciliary body and/or iris involvement, endoresection is more suitable for posteriorly located tumor without ciliary body involvement. Both approaches are suitable for large tumors with >8 mm in thickness. In general, eyes containing these large tumors have a very dismal prognosis regarding long-term visual function, eye retention, and irradiation-induced side effects. By removing the tumor burden from the eye, histopathologic and cytogenetic information of the tumor is available and complications associated with the so-called toxic tumor syndrome are avoided. However, both types of surgical resection are challenging surgical procedures, bearing the risk of early and late postoperative complications.

An environment-dependent interatomic potential for silicon carbide: calculation of bulkproperties, high-pressure phases, point and extended defects, and amorphousstructures

An interatomic potential has been developed to describe interactions in silicon, carbon andsilicon carbide, based on the environment-dependent interatomic potential (EDIP) (Bazantet al 1997 Phys. Rev. B 56 8542). The functional form of the original EDIP has beengeneralized and two sets of parameters have been proposed. Tests with these twopotentials have been performed for many properties of SiC, including bulk properties,high-pressure phases, point and extended defects, and amorphous structures.One parameter set allows us to keep the original EDIP formulation for silicon,and is shown to be well suited for modelling irradiation-induced effects in siliconcarbide, with a very good description of point defects and of the disordered phase.The other set, including a new parametrization for silicon, has been shown to beefficient for modelling point and extended defects, as well as high-pressure phases.

Atomistic Computer Simulations of Irradiation-Induced Effects in Nanostructured Carbon Materials

Atomistic Computer Simulations of Irradiation-Induced Effects in Nanostructured Carbon Materials

Mössbauer study of ferromagnetic metallic glasses irradiated by swift heavy ions at temperatures 100 and 300 K

The effect of swift heavy ion irradiation on ferromagnetic metallic glasses Fe40Ni38Mo4B18 and Fe78Si9B13 has been studied. The ion beams used are 100 MeV 127I and 180 MeV 197Au. The specimens were irradiated at fluences ranging from 3 × 1012 to 1.5 × 1014 ions/cm2. The irradiations have been carried out at temperatures 100 and 300 K. The magnetic moments are sensitive towards the irradiation conditions such as irradiation temperature and stopping power of incident ion beam. The irradiation-induced effects have been monitored, by using Mossbauer spectroscopy. The modifications in magnetic anisotropy and hyperfine magnetic field distributions, as an effect of different irradiation temperature as well as different stopping power have been discussed. After irradiation, all the samples remain amorphous and magnetic anisotropy considerably changes from its original in-plane direction. The results show enhancement in magnetic anisotropy in the specimen irradiated at 100 K, as compared to that of irradiated at 300 K. It is expected that at low temperature, the stresses produced in the material would remain un-annealed, compared to the samples irradiated at room temperature and therefore, the modification in magnetic anisotropy would be enhanced. A distribution of hyperfine magnetic field, of the samples irradiated at low temperature, show a small but distinct peak at ∼ 11 Tesla, indicating Fe-B pairing.

X-ray Irradiation-Induced Carrier Doping Effects in Organic Dimer–Mott Insulators

We report X-ray irradiation-induced carrier doping effects on the electrical conductivity in the organic dimer-Mott insulators $\kappa$-(ET)$_{2}$$X$ with $X =$ Cu[N(CN)$_{2}$]Cl and Cu$_{2}$(CN)$_{3}$. For $\kappa$-(ET)$_{2}$Cu[N(CN)$_{2}$]Cl, we have observed a large decrease of the resistivity by 40 % with the irradiation at 300 K and the metal-like temperature dependence down to about 50 K. The irradiation-induced defects expected at the donor molecule sites might cause a local imbalance of the charge transfer in the crystal. Such molecular defects result in the effective doping of carriers into the half-filled dimer-Mott insulators.

Poly(ADP-ribose) polymerase inhibition combined with irradiation: A dual treatment concept to prevent neointimal hyperplasia after endarterectomy

In a rat model of endarterectomy we investigated the potential role of the peroxynitrite-poly(ADP-ribose) polymerase (PARP) pathway in neointima formation and the effects of irradiation, pharmacologic inhibition of PARP, or combined pharmacologic inhibition of PARP and irradiation on vascular remodeling. Carotid endarterectomy was performed by incision of the left carotid artery with removal of intima in Sprague-Dawley rats. Six groups were studied: sham-operated rats (n = 10), control endarterectomized rats (n = 10), or endarterectomized rats irradiated with 15 Gy (n = 10), or treated with PARP inhibitor, INO-1001 (5 mg/kg/day) (n = 10), or with combined treatment with INO-1001 and irradiation with 5 Gy (n = 10) or with 15 Gy (n = 10). After 21 days, neointima formation and vascular remodeling were assessed. Neointima formation after endarterectomy was inhibited by postoperative irradiation with 15 Gy and was attenuated by PARP inhibition. However, in parallel to inhibition of neointimal hyperplasia, activation of the peroxynitrite-PARP pathway in the outer vessel wall layers was triggered by postoperative irradiation. Combined pharmacologic PARP inhibition and irradiation with 15 Gy significantly reduced both neointimal hyperplasia and activation of the peroxynitrite-PARP pathway in the outer vessel wall layers. Combination of PARP inhibition and irradiation with 5 Gy was less effective than both PARP inhibition or irradiation with 15 Gy alone. We conclude, that combined PARP inhibition and irradiation with 15 Gy may be a new dual strategy for prevention of restenosis after surgical vessel reconstruction: combining the strong antiproliferative effect of irradiation and ameliorating irradiation-induced side effects caused by excessive PARP activation.

Stress-induced corneal epithelial apoptosis mediated by K+ channel activation

One of the functional roles of the corneal epithelial layer is to protect the cornea, lens and other underlying ocular structures from damages caused by environmental insults. It is important for corneal epithelial cells to maintain this function by undergoing continuous renewal through a dynamic process of wound healing. Previous studies in corneal epithelial cells have provided substantial evidence showing that environmental insults, such as ultraviolet (UV) irradiation and other biohazards, can induce stress-related cellular responses resulting in apoptosis and thus interrupt the dynamic process of wound healing. We found that UV irradiation-induced apoptotic effects in corneal epithelial cells are started by the hyperactivation of K+ channels in the cell membrane resulting in a fast loss of intracellular K+ ions. Recent studies provide further evidence indicating that these complex responses in corneal epithelial cells are resulted from the activation of stress-related signaling pathways mediated by K+ channel activity. The effect of UV irradiation on corneal epithelial cell fate shares common signaling mechanisms involving the activation of intracellular responses that are often activated by the stimulation of various cytokines. One piece of evidence for making this distinction is that at early times UV irradiation activates a Kv3.4 channel in corneal epithelial cells to elicit activation of c-Jun N-terminal kinase cascades and p53 activation leading to cell cycle arrest and apoptosis. The hypothetic model is that UV-induced potassium channel hyperactivity as an early event initiates fast cell shrinkages due to the loss of intracellular potassium, resulting in the activation of scaffolding protein kinases and cytoskeleton reorganizations. This review article presents important control mechanisms that determine Kv channel activity-mediated cellular responses in corneal epithelial cells, involving activation of stress-induced signaling pathways, arrests of cell cycle progression and/or induction of apoptosis.