Allyl isothiocyanate attenuates LED light-induced retinal damage in rats: exploration for the potential molecular mechanisms.

PURPOSE: Environmental light pollution due to artificial light may increase the rate and severity of retinal diseases, and plant-based nutritional interventions with antioxidant properties have the potential to reverse this phenomenon. We aimed to investigate the potential effects of allyl isothiocyanate (AITC) against white light-emitting diode (LED)-induced retinal degeneration (RD) in the rats. METHODS: Twenty-eight male rats were allocated as: (i) Control, (ii) LED, (iii) LED + AITC (10 mg/kg BW), (iv) LED + AITC (20 mg/kg BW). Rats were administered with AITC for 28 days, followed by two days of intense environmental LED light (750 Lux) exposure to the eyes. Animals were sacrificed immediately at the end of the study, then the blood and eyeballs were taken for the biochemical, western blotting, and histopathology examinations. RESULTS: AITC lowered the serum and retina malondialdehyde (MDA) levels while significantly (p < 0.05) improving the retinal antioxidant enzyme activities in a dose-dependent manner. AITC improved retinal and outer nuclear layer (ONL) thickness as compared to the LED group (p < 0.05). AITC increased the levels of Bax, caspase-3, HO-1, GAP43, and VEGF, while decreasing IL-1ß, IL-6, NF-κB, Bcl-2, GFAP, Grp78, activating ATF4 and ATF6 as compared to the LED group (p < 0.05). CONCLUSION: In conclusion, four weeks of AITC administration to the rats showed specific protective effects against two days of intense LED light-induced retinal damage; through antiinflammatory, antioxidant, anti-apoptotic, and modulating mitochondrial metabolic pathways.

Effects on the Ocular Surface from Reading on Different Smartphone Screens: A Prospective Randomized Controlled Study.

The purpose of this study was to investigate the influence of smartphone reading on the ocular surface and to compare the various effects of different screens and light conditions on the ocular surface. One hundred nineteen volunteers were randomly divided into: light + organic light-emitting diode (OLED), light + electronic ink (eINK), dark + OLED, and dark + eINK. Ocular surface examinations, including noninvasive break-up time (NIBUT), noninvasive keratograph tear meniscus height (NIKTMH), ocular redness, fluorescein break-up time (FBUT), corneal fluorescein staining, meibomian gland assessment, Schirmer I Test, and blinking frequency, were performed before and after a reading task. Symptoms were evaluated using the Ocular Surface Disease Index (OSDI) and Computer Vision Syndrome Questionnaire (CVS-Q). NIBUT and FBUT were decreased statistically significantly after participants read on an OLED screen for 2 hours compared with the baseline in light and dark environments, whereas no statistically significant decrease was observed on an eINK screen. NIKTMH was statistically significantly decreased after reading on an OLED screen in light and dark settings, and the eINK screen had a lesser effect on NIKTMH. An obvious increase in the ocular redness, OSDI and CVS-Q scores was observed after reading on an OLED screen, whereas the eINK screen had a lesser effect on these indicators. Blink rate increased gradually in OLED subgroups during the reading task, whereas no statistically significant difference was observed in the eINK subgroups. Our research suggested that reading on an OLED screen can cause ocular surface disorder and obvious subjective discomfort, whereas reading on an eINK screen can minimize ocular surface disorder in both dark and light environments.

Case-control study of brain and other central nervous system cancer among workers at semiconductor and storage device manufacturing facilities.

OBJECTIVE: This study evaluated the relationship between brain and other central nervous system cancer ('CNS cancer') and exposures at two semiconductor and electronic module manufacturing facilities and at a storage device manufacturing facility. METHODS: The case-control study, nested in a cohort of 126 836 employees, compared 120 CNS cancer cases and 1028 matched controls with respect to employment in 10 process groups and estimated cumulative exposure to 31 known or possible carcinogens. RESULTS: CNS cancer was associated with module manufacturing operations at two facilities. Module manufacturing is a process that begins with production of ceramic substrates followed by attachment of completed semiconductor chips and metal-containing circuitry resulting in a high performing electronic device. Positive associations with the highest tertile of estimated cumulative exposure were found for several chemicals, including 2-butoxyethanol, cyclohexanone, ortho-dichlorobenzene, cadmium, molybdenum, trichloroethylene and vinyl chloride. CONCLUSIONS: Results suggested positive associations between CNS cancer and specific operations and chemicals experienced in the semiconductor and electronic module manufacturing industry. However, lack of external support for these findings precludes a causal interpretation, and the observed associations may have been due to chance.

Semiconductor Work and the Risk of Spontaneous Abortion: A Systematic Review and Meta-Analysis.

(1) Background: In the semiconductor industry, female workers were identified as having an increased risk of spontaneous abortion (SA). To date, the association between semiconductor work and SA is controversial. We aimed to assess the association between semiconductor work and specific processes and SA, in the semiconductor industry. (2) Methods: A literature search was conducted using databases such as PubMed, Embase, Cochrane library, and other core databases, from the date of inception of these databases to 31 July 2019. Studies that identified SA risk in female workers in the semiconductor industry were included. (3) Results: We identified 529 studies, of which six studies were included in the meta-analysis. During 1980-1993, the risk of SA in fabrication (Fab) workers was significantly higher than non-Fab workers (RR, 1.29; 95% CI, 1.05-1.57). Photolithography workers had a higher SA risk than non-process and office workers (RR, 1.41; 95% CI, 1.13-1.77). (4) Conclusion: Meta-analysis indicates a statistically significant association between Fab-work and SA. Specific process and chemical exposure meta-analyses need to be interpreted carefully considering bias. Because of the rapid change in the semiconductor industry, it is necessary to conduct an elaborate cohort study taking into consideration the current working environment.

Background and Activities of the Samsung Ombudsperson Commission in Korea.

OBJECTIVES: The Samsung Ombudsperson Commission was launched as an independent third-party institution following an agreement among Samsung Electronics, Supporters for Health and Right of People in Semiconductor Industry (Banolim in Korean, an independent NGO), and the Family Compensation Committee, in accordance with the industry accident prevention measure required by the settlement committee to address the issues related to employees who allegedly died from leukemia and other diseases as a result of working at Samsung's semiconductor production facilities. METHODS: The Commission has carried out a comprehensive range of activities to review and evaluate the status of the company's occupational accidents management system, as well as occupational safety and health risk management within its facilities. RESULTS: Based on the results of this review, termed a comprehensive diagnosis, the Commission presented action plans for improvement to strengthen the company's existing safety and health management system and to effectively address uncertain risks in this area going forward. CONCLUSIONS: The Commission will monitor the execution of the suggested tasks and provide advice and guidance to ensure that Samsung's semiconductor and liquid crystal display production lines are safer.

Semiconductor Work and Adverse Pregnancy Outcomes Associated with Male Workers: A Retrospective Cohort Study.

OBJECTIVES: A hazardous work environment in semiconductor factories is a threat to the workers' health. Semiconductor manufacturing characteristically requires young workers, and reproductive toxicity is an important issue. Studies investigating reproductive toxicity among individuals working in the semiconductor manufacturing industry have primarily focused on outcomes in women. Information on the reproductive health of male semiconductor factory workers is limited. This study aimed to evaluate the association between workplace exposures among male workers in a Korean semiconductor company and adverse pregnancy outcomes. METHODS: Based on the data from the 2015 Semiconductor Health Survey (SHS), which evaluated the workplace exposures, pregnancy outcomes, and general health of 21 969 employees of the semiconductor industry in South Korea, we included 3868 male workers with 7504 pregnancy outcomes identified by self-reports for this retrospective cohort study. Data regarding the pregnancy outcomes, order of pregnancy, and the years of the outcomes were collected via the SHS questionnaire. Adverse pregnancy outcomes were defined as preterm labor, spontaneous abortion, and stillbirth. Workplace exposures were classified as fabrication, assembly, others, lab, and office work (reference group). A generalized estimating equations model including repeated events of individuals and producing relative risk (RR) and 95% confidence interval (CI) was used to estimate the association between workplace exposure and adverse pregnancy outcomes. Analyses were adjusted for work location, spouse's employment in semiconductor production work, educational level, marital status, risky alcohol drinking, smoking status, body mass index, order of pregnancy, and age and year of pregnancy outcome, which were based on a priori decisions. RESULTS: The adjusted risk for adverse outcomes was higher [RR (95% CI): 1.47 (1.04, 2.07)] among assembly process workers compared with the office workers. Adjusted risks for adverse outcomes among workers in assembly and fabrication, whose spouses also worked in semiconductor production, were 1.60 (95% CI: 1.04, 2.46) and 1.74 (95% CI: 1.18, 2.57) times higher, respectively, compared with the office workers with spouses not working in semiconductor production. CONCLUSIONS: Based on these findings, semiconductor work might be considered a risk factor for reproductive toxicity among male workers, especially for those whose spouses have the same job.

Several biological benefits of the low color temperature light-emitting diodes based normal indoor lighting source.

Currently, light pollution has become a nonnegligible issue in our daily life. Artificial light sources with high color temperature were deem to be the major pollution source, which could induce several adverse effects on human's health. In our previous research, we have firstly developed an artificial indoor light with low color temperature (1900 K). However, the biological effects of this artificial light on human's health are unclear. Here, four artificial lights (1900 K, 3000 K, 4000 K and 6600 K) were used to evaluate some biological changes in both human (in total 152 person-times) and murine models. Compared with other three high color temperature artificial lights, our lights (1900 K) presented a positive effect on promoting the secreting of melatonin and glutamate, protecting human's eyes, accelerating would healing and hair regeneration. These systematical studies indicated that the proposed low color temperature (1900 K) light could provide several significant benefits in human's daily life.

The tissue viability imaging system-Suitable method for discovering minimal skin changes in occupational screenings? Results of a cross-sectional field study.

BACKGROUND: For early detection of initial skin changes in occupational screenings, only few objective assessment systems are available. OBJECTIVES: With the aim of assessing an objective measurement method for hand eczema, we trialed the application of the tissue viability imaging (TiVi) system, quantifying erythema non-invasively by polarized light spectroscopy. MATERIALS AND METHODS: In a field study with 625 employees of a semiconductor production company, 411 were exposed to prolonged wearing of occlusive gloves in the clean room. TiVi system and Hand Eczema Score for Occupational Screenings (HEROS), a quantitative skin score for the hands, were used, supplemented by a standardized personal interview. RESULTS: TiVi values of 65 up to 246 for each hand (palm or back), for each participant summed to overall 289 up to 848 (median 389), were measured. Higher TiVi values were noted for men, smokers, and with increasing age. Correlation between TiVi and HEROS was only weak. Several factors like skin pigmentation, thickness of the skin, or tattoos seem to influence TiVi results. CONCLUSIONS: The practical relevance of one-time measurements with the TiVi system in occupational screenings seems to be limited. Specifically, the TiVi system cannot replace dermatological examinations at the workplace. Notwithstanding, the application for other scientific purposes might be useful.

Comparing Semiconductor Nanocrystal Toxicity in Pregnant Mice and Non-Human Primates.

Rationale: Despite growing use of engineered nanomaterials (ENM) in applications from electronics to medicine, the potential risk to human health remains a critical concern within clinical use. ENM exposure during pregnancy can potentially cause reproductive toxicity even at levels that produce no measurable harm to animals in normal conditions. Methods: Phospholipid micelle-encapsulated CdSe/CdS/ZnS semiconductor nanocrystals with an average hydrodynamic diameter of 60 nm were intravenously injected during pregnancy in both rodent and nonhuman primate animal models. Cadmium concentration levels and maternal haematological and biochemical markers were determined, along with histopathological examination of major organs. Results: Nanocrystals were found to have crossed the placenta from mother to fetus in both rodents and nonhuman primates. However, the animal models display different responses with respect to reproductive toxicity. In the rodent model, toxicity symptoms are absent in treated subjects, with no observed gestational or fetal abnormalities and complications. A significantly higher miscarriage rate of 60% is recorded for macaques after prenatal nanoparticle administration. There was a miscarriage rate of 15% in the general population despite only ~0.16% of the initial cadmium dose present in the fetus. Blood and biochemical markers of treated macaques indicate acute hepatocellular injury within a week after nanoparticle administration. Histology of major organs of the miscarried macaque fetuses show no abnormalities. Conclusion: The potential of nanomaterials to cross the placenta and impact fetal survival in primates suggest the necessity of precautionary measures to prevent gestational exposure of ENMs.

Linking Subcellular Disturbance to Physiological Behavior and Toxicity Induced by Quantum Dots in Caenorhabditis elegans.

The wide-ranging applications of fluorescent semiconductor quantum dots (QDs) have triggered increasing concerns about their biosafety. Most QD-related toxicity studies focus on the subcellular processes in cultured cells or global physiological effects on whole animals. However, it is unclear how QDs affect subcellular processes in living organisms, or how the subcellular disturbance contributes to the overall toxicity. Here the behavior and toxicity of QDs of three different sizes in Caenorhabditis elegans (C. elegans) are systematically investigated at both the systemic and the subcellular level. Specifically, clear size-dependent distribution and toxicity of the QDs in the digestive tract are observed. Short-term exposure of QDs leads to acute toxicity on C. elegans, yet incurring no lasting, irreversible damage. In contrast, chronic exposure of QDs severely inhibits development and shortens lifespan. Subcellular analysis reveals that endocytosis and nutrition storage are disrupted by QDs, which likely accounts for the severe deterioration in growth and longevity. This work reveals that QDs invasion disrupts key subcellular processes in living organisms, and may cause permanent damage to the tissues and organs over long-term retention. The findings provide invaluable information for safety evaluations of QD-based applications and offer new opportunities for design of novel nontoxic nanoprobes.

In vitro toxicity evaluation of Ti(4+)-stabilized γ-Bi2O3 sillenites.

We report results regarding the in vitro toxicology of γ-Bi2O3 represented by its isomorphous phase Bi12TiO20 (γ-BTO). The γ-BTO microparticles were synthesized by two methods: coprecipitation from a bismuth nitrate-tetrabutyl titanate solution and solid state reaction of Bi2O3 and TiO2 oxides. The structural and morphological characteristics of the obtained materials were determined using X-ray diffraction (XRD), selected area electron diffraction (SAED), transmission (TEM) and scanning (SEM) electron microscopy. The elemental composition was investigated using energy dispersive spectrometry (EDS). The cytotoxicity and oxidative/nitrosative stress (intracellular reactive oxygen species (ROS) and nitric oxide (NO) release) induced by the studied microparticles in HepG2, SH-SY5Y and 3T3-L1 cell cultures were determined using the MTT, DCF-DA (2',7'-dichlorfluorescein-diacetate) and Griess methods respectively. Depending on the cell type and γ-BTO concentration, results showed only weak cytotoxic effects after 24h of γ-BTO exposure and cell proliferation effects for longer treatment times. Only reduced NO release increases (corresponding to high γ-BTO concentrations) were detected in case of SH-SY5Y and 3T3-L1 cells. The intracellular ROS production (higher for HepG2 cells) appeared inversely proportional to the γ-BTO concentration. The obtained results indicated a promising in vitro biocompatibility of γ-BTO and encourage further studies regarding its potential for biomedical applications.

PdO doping tunes band-gap energy levels as well as oxidative stress responses to a Co3O4 p-type semiconductor in cells and the lung.

We demonstrate through PdO doping that creation of heterojunctions on Co3O4 nanoparticles can quantitatively adjust band-gap and Fermi energy levels to study the impact of metal oxide nanoparticle semiconductor properties on cellular redox homeostasis and hazard potential. Flame spray pyrolysis (FSP) was used to synthesize a nanoparticle library in which the gradual increase in the PdO content (0-8.9%) allowed electron transfer from Co3O4 to PdO to align Fermi energy levels across the heterojunctions. This alignment was accompanied by free hole accumulation at the Co3O4 interface and production of hydroxyl radicals. Interestingly, there was no concomitant superoxide generation, which could reflect the hole dominance of a p-type semiconductor. Although the electron flux across the heterojunctions induced upward band bending, the E(c) levels of the doped particles showed energy overlap with the biological redox potential (BRP). This allows electron capture from the redox couples that maintain the BRP from -4.12 to -4.84 eV, causing disruption of cellular redox homeostasis and induction of oxidative stress. PdO/Co3O4 nanoparticles showed significant increases in cytotoxicity at 25, 50, 100, and 200 µg/mL, which was enhanced incrementally by PdO doping in BEAS-2B and RAW 264.7 cells. Oxidative stress presented as a tiered cellular response involving superoxide generation, glutathione depletion, cytokine production, and cytotoxicity in epithelial and macrophage cell lines. A progressive series of acute pro-inflammatory effects could also be seen in the lungs of animals exposed to incremental PdO-doped particles. All considered, generation of a combinatorial PdO/Co3O4 nanoparticle library with incremental heterojunction density allowed us to demonstrate the integrated role of E(v), E(c), and E(f) levels in the generation of oxidant injury and inflammation by the p-type semiconductor, Co3O4.

[Psychophysiological research of changes of the functional condition of the neuro-psychic sphere of younger schoolchildren during the school day at luminescent and LED lighting in the classroom].

The purpose of the study is to test the hypothesis that the LED lighting (LL) in training class does not have a negative impact on the change in the functional state of the neuro-psychiatric sphere in pupils by the end of the school day, if compared with traditional for schools fluorescent lighting (FL). With the help of specially matched methods for psychophysiological examination there was performed the testing of changes in the functional state of the neuro-psychiatric in pupils during the school day and there was made an analysis of these changes in dependence on the type of lighting the classroom. LL, if compared to FL, was established to lead to a significant weakening of the negative changes of functional lability of the visual analyzer, the power of excitation of the nervous system and cognitive functions, as well as to an increase in positive changes in psychomotorics. The data obtained allow us to recommend the use of LED lighting equipment in modern schools.

Microchip-associated sarcoma in a shrew (Suncus murinus).

A 16-mo-old female house musk shrew (Suncus murinus) with a 1-wk history of a rapidly growing subcutaneous mass in the interscapsular region was euthanized and submitted for necropsy. Macroscopic examination identified an irregular, well-demarcated, solid, tan-white subcutaneous mass. A small cavity containing a microchip device was present at the center of the mass. In addition, massive splenomegaly was evident grossly. Histologically, the subcutaneous mass comprised spindle cells arranged in a storiform pattern of interweaving bundles, consistent with a high-grade soft tissue sarcoma with multifocal necrosis. Immunohistochemical investigation suggested that the neoplastic cells were positive for neuron-specific enolase and (rarely) α-smooth muscle actin and negative for cytokeratin, desmin, S100, and vimentin. In light of the mesenchymal histopathologic phenotype and the lack of specific immunoreactivity pattern, the mass was considered to be most consistent with a poorly differentiated sarcoma. To our knowledge, this is the first report of a microchip-associated soft tissue sarcoma in a shrew.

An investigation into the potential for different surface-coated quantum dots to cause oxidative stress and affect macrophage cell signalling in vitro.

The aim of this study was to investigate the ability of a series of different surface-coated quantum dots (QDs) to cause oxidative stress and affect cell signalling in J774.A1 macrophages. Organic QDs caused a significant (p < 0.001) decrease in glutathione (GSH) levels over 24 h, while COOH and NH(2) (PEG) QDs induced a significant decrease (p < 0.05) in GSH at 6 and 24 h only. J774.A1 cytosolic Ca(2+) concentration significantly increased (p < 0.01) 30 min after treatment with all QDs. Trolox was, however, able to prevent the COOH and NH(2) (PEG) QD-induced Ca(2+) signal, but not the organic QD induced effect. All QDs tested were observed to have a relatively low ability to stimulate increased expression of the pro-inflammatory cytokine tumour necrosis factor-alpha (TNF-alpha). In conclusion, QDs differ in their interactions with macrophages according to their specific surface properties.

Interfacial charge transfer between CdTe quantum dots and gram negative vs gram positive bacteria.

Oxidative toxicity of semiconductor and metal nanomaterials to cells has been well established. However, it may result from many different mechanisms, some requiring direct cell contact and others resulting from the diffusion of reactive species in solution. Published results are contradictory due to differences in particle preparation, bacterial strain, and experimental conditions. It has been recently found that C(60) nanoparticles can cause direct oxidative damage to bacterial proteins and membranes, including causing a loss of cell membrane potential (depolarization). However, this did not correlate with toxicity. In this study we perform a similar analysis using fluorescent CdTe quantum dots, adapting our tools to make use of the particles' fluorescence. We find that two Gram positive strains show direct electron transfer to CdTe, resulting in changes in CdTe fluorescence lifetimes. These two strains also show changes in membrane potential upon nanoparticle binding. Two Gram negative strains do not show these effects-nevertheless, they are over 10-fold more sensitive to CdTe than the Gram positives. We find subtoxic levels of Cd(2+) release from the particles upon irradiation of the particles, but significant production of hydroxyl radicals, suggesting that the latter is a major source of toxicity. These results help establish mechanisms of toxicity and also provide caveats for use of certain reporter dyes with fluorescent nanoparticles which will be of use to anyone performing these assays. The findings also suggest future avenues of inquiry into electron transfer processes between nanomaterials and bacteria.

Neuronal cell biocompatibility and adhesion to modified CMOS electrodes.

The use of CMOS (Complementary Metal Oxide Semiconductor) integrated circuits to create electrodes for biosensors, implants and drug-discovery has several potential advantages over passive multi-electrode arrays (MEAs). However, unmodified aluminium CMOS electrodes may corrode in a physiological environment. We have investigated a low-cost electrode design based on the modification of CMOS metallisation to produce a nanoporous alumina electrode as an interface to mammalian neuronal cells and corrosion inhibitor. Using NG108-15 mouse neuroblastoma x rat glioma hybrid cells, results show that porous alumina is biocompatible and that the inter-pore distance (pore pitch) of the alumina has no effect on cell vitality. To establish whether porous alumina and a cell membrane can produce a tight junction required for good electrical coupling between electrode and cell, we devised a novel cell detachment centrifugation assay to assess the long-term adhesion of cells. Results show that porous alumina substrates produced with a large pore pitch of 206 nm present a significantly improved surface compared to the unmodified aluminium control and that small pore-pitches of 17 nm and 69 nm present a less favourable surface for cell adhesion.

Health risk in the offspring of female semiconductor workers.

BACKGROUND: There are no published studies focusing on adverse birth outcomes or infant mortality in the semiconductor industry. AIM: To investigate whether female workers have higher risks of any adverse birth outcome or death from congenital malformation. METHODS: A total of 27,610 female workers had been employed in eight semiconductor companies in Taiwan between 1980 and 2000. Using the national birth registry, their live born children were identified, and then any deaths under 5 years of age with or without congenital malformations were identified by linking with the national death registry. Periconceptional exposure was defined as the mother having been employed in the semiconductor industry 3 months before and 3 months after conception of the live born infants. RESULTS: A total of 24,223 live births were included. No significant association between adverse birth outcomes or death with congenital malformation and maternal employment in semiconductor industry was found either in the period of 1980-94 or 1995-2000. CONCLUSIONS: There is no convincing evidence that female workers employed during the periconceptional period in the semiconductor industry had higher risks of having adverse birth outcomes or death due to congenital malformations. However, prospective research is warranted to confirm these findings.

Matrix-addressable, active electrode arrays for neural stimulation using organic semiconductors-cytotoxicity and pilot experiments in vivo.

Organic field effect transistors can be integrated into micromachined polyimide-based neural stimulation electrode arrays in order to build active switching matrices. With this approach, a matrix of N x M electrode contacts requires only N + M interconnects to a stimulator when active switching elements are used instead of N x M interconnects. In this paper, we demonstrated that pentacene-based organic field effect transistors (OFETs) can be used to drive stimulation currents through neural electrodes in a physiological-like environment. In order to prove the general applicability as an implant material, the cytotoxicity of pentacene was evaluated with respect to potential effects on cell viability. The results of these tests indicate that extracts from pentacene inhibit neither proliferation nor metabolism of the tested mouse fibroblasts. However, some effect on cell spreading was observed when cells were in direct contact to pentacene for 48 h. In pilot experiments it was demonstrated for the very first time that pentacene transistors can be used as switching elements, acting as voltage-controlled current sources, capable of driving currents suitable for electrical stimulation of a peripheral nerve via a tripolar cuff electrode.