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Core-collapse supernovae are among the most magnificent events in theobservable universe. They produce many of the chemical elements necessary forlife to exist and their remnants -- neutron stars and black holes -- areinteresting astrophysical objects in their own right. However, despitemillennia of observations and almost a century of astrophysical study, theexplosion mechanism of core-collapse supernovae is not yet well understood.Hyper-Kamiokande is a next-generation neutrino detector that will be able toobserve the neutrino flux from the next galactic core-collapse supernova inunprecedented detail. We focus on the first 500 ms of the neutrino burst,corresponding to the accretion phase, and use a newly-developed, high-precisionsupernova event generator to simulate Hyper-Kamiokande's response to fivedifferent supernova models. We show that Hyper-Kamiokande will be able todistinguish between these models with high accuracy for a supernova at adistance of up to 100 kpc. Once the next galactic supernova happens, thisability will be a powerful tool for guiding simulations towards a precisereproduction of the explosion mechanism observed in nature.

Hyper-Kamiokande is the next generation underground water Cherenkov detectorthat builds on the highly successful Super-Kamiokande experiment. The detectorwhich has an 8.4~times larger effective volume than its predecessor will belocated along the T2K neutrino beamline and utilize an upgraded J-PARC beamwith 2.6~times beam power. Hyper-K's low energy threshold combined with thevery large fiducial volume make the detector unique, that is expected toacquire an unprecedented exposure of 3.8~Mton$\cdot$year over a period of20~years of operation. Hyper-Kamiokande combines an extremely diverse scienceprogram including nucleon decays, long-baseline neutrino oscillations,atmospheric neutrinos, and neutrinos from astrophysical origins. The scientificscope of this program is highly complementary to liquid-argon detectors forexample in sensitivity to nucleon decay channels or supernova detection modes.Hyper-Kamiokande construction has started in early 2020 and the experiment isexpected to start operations in 2027. The Hyper-Kamiokande collaboration ispresently being formed amongst groups from 19 countries including the UnitedStates, whose community has a long history of making significant contributionsto the neutrino physics program in Japan. US physicists have played leadingroles in the Kamiokande, Super-Kamiokande, EGADS, K2K, and T2K programs.

One of the most significant threats to global public health in the 21st century is the novel coronavirus disease (COVID-19) caused by SARS-CoV-2. It rapidly turned into a global pandemic after it was identified in late 2019, and the World Health Organization announced the end of the pandemic on May 5, 2023. Current strategies for managing this disease include vaccination and repurposing antimalarial and antibiotic medications to alleviate symptoms like fever and throat pain, which are associated with acute respiratory distress syndrome (ARDS). Antiviral drugs such as chloroquine, hydroxychloroquine, azithromycin, remdesivir, and favipiravir have been repurposed for the treatment of COVID-19. They were previously recommended for treating SARS-CoV and MERS-CoV. However, the inefficacy and adverse side effects of these repurposed drugs led to a decrease in their widespread use in treating COVID-19 patients. The lack of approved drugs for combating this coronavirus and its unpredictable variants remains a significant challenge., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

The present study is focused on the integration of microreactors to synthesize visible light active nanophotocatalysts for inline photocatalytic degradation of organic dye and antibacterial activity. A wire-assisted and a rapid laser micromachining technique has been employed for the fabrication of polydimethylsiloxane (PDMS) and poly(methyl methacrylate) (PMMA)-based microreactors, respectively. By varying the design and chemical reagents involved, different sizes of visible light active Ag 2 S nanoparticles were prepared via a continuous microfluidics approach using fabricated microreactors. When polyvinylpyrrolidone (PVP) was utilized as the capping agent during the reaction, smaller particles of the size of ~ 15 nm were observed. The photocatalytic performance of these nanoparticles has been evaluated inline by employing the single-inlet planar microreactor as a function of flow rate and channel length. The photocatalyst durability test and a comparative photocatalytic efficiency study between the microreactor and the conventional beaker reactor have also been carried out. Under visible light, these nanoparticles exhibit a remarkable enhancement of ~ 94.5% in the inline microreactor-based photocatalytic degradation of methylene blue dye. The slower the flow rate and longer the channel length, gradual enhancement in the performance has been observed. Also, these nanoparticles express an antibacterial effect with very high efficacy even at very low (2 mg mL -1 ) concentration toward the inhibition of Escherichia Coli., (© 2020 American Society for Photobiology.)

In an attempt to develop low cost, energy efficient and advanced electrode material for lithium-ion batteries (LIBs), waste-to-wealth derived as well as value added spent battery materials as potential alternatives assume paramount importance. By combining the low lithiation potential advantages, one can arrive at energy efficient electrodes bestowed with cost effective and eco-friendly benefits required for practical LIB applications. In the present study, Zn and Mn-salts along with C were successfully extracted from the spent zinc carbon batteries through a simple and efficient hydrometallurgy approach and decomposed thermally to obtain ZnMn 2 O 4 at 350 °C for 12 h and 450 °C for 3 h. Further, C-ZnMn 2 O 4 nanocomposites were prepared and demonstrated for appreciable electrochemical performance in LIB assembly. Our results show that C-ZnMn 2 O 4 composites prepared at 350 °C and 450 °C demonstrate better performance than pristine ZnMn 2 O 4 anode due to the improved electronic conductivity rendered by the added carbon obtained from spent primary battery. In particular, C-ZnMn 2 O 4 at 350 °C @12 h exhibits appreciable electrochemical performance by showing a stable and higher capacity of 600 mAhg -1 at a current density of 50 mAg -1 in the voltage range of 0.01-3.0 V and qualifies it as a better performing cost-effective anode for LIBs., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Appropriate recycling of waste to reusable materials is much sought after in the scientific community to control the incessant rising pollution in environment due to insufficient management of waste materials. To address this issue, efforts were directed to obtain SnO 2 -Fe 3 O 4 nanocomposites from scrap tin plated steel and the use of these composites for the degradation of organic pollutant. We have demonstrated a novel, efficient and facile hydrometallurgy approach for the extraction of iron from waste tin plated steel containers found in plenty in the common waste generated in society. The extracted iron has further been utilized for the preparation of SnO 2 :Fe 3 O 4 nanocomposites with different compositions (SnO 2 :Fe 3 O 4 ratio of 93.2:6.8, 85:15, 58:42 and 40:60) using hydrothermal route. The photocatalytic activities of nanocomposite were determined spectroscopically using Rhodamine-B (RhB) as a model dye. Our results indicate that among all the composites with SnO 2 (85%):Fe 3 O 4 (15%) exhibits the best photocatalytic efficiency under UV light whereas the composition of SnO 2 (93.2%):Fe 3 O 4 (6.28%) is the most efficient in visible light. The above visible light efficiency was supported by density functional theory (DFT) studies which suggest a small amount of pure Fe is present at the Sn sites in the nanocomposite, leading to the reduction in the band gap of the nanocomposite and resulting in absorption in the visible range. Thus, in the present study, we have shown a process of conversion of waste to nanomaterials and its utilization for treatment of organic pollutants., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Context: Intra-articular (IA) bupivacaine and adjuvants are used in multimodal analgesia for knee arthroscopy., Aims: To evaluate the efficacy of IA plain bupivacaine and bupivacaine with adjuvants (dexmedetomidine and magnesium [Mg] sulfate) for postoperative analgesia in knee arthroscopy., Settings and Design: This was a randomized controlled study in a tertiary care hospital., Methodology: Fifty-four patients were randomly allocated to receive 20 ml of study drug, 0.25% bupivacaine (Group B), 0.25% bupivacaine with 0.5 μg/kg of dexmedetomidine (Group D), and 0.25% bupivacaine with 10 mg/kg of Mg sulfate (Group M). Duration of analgesia, visual analog score for pain at rest (VAS-R) and movement (VAS-M), and number of times rescue analgesics were given in the first 24 h of postoperative period were assessed. Vital parameters and any side effects of the drugs were also noted at immediate (0, 5, 10, 15, and 30 min, 1 h) and late postoperative period (2, 4, 6, 12 and 24 h)., Results: Duration of analgesia was prolonged in bupivacaine-dexmedetomidine and bupivacaine-Mg sulphate groups as compared to bupivacaine alone (5.97 ± 1.76 h, 13.44 ± 7.87 h, and 14.61 ± 8.83 h in Groups B, D, and M, respectively; P = 0.001). The VAS-R and VAS-M were less with Group D and Group M compared to Group B ( P = 0.002 in VAS-R and P = 0.004 in VAS-M). The number of times rescue analgesic used was more in the Group B (2.06 ± 0.8, 0.94 ± 0.8, and 0.89 ± 0.9 in Groups B, D, and M, respectively; P < 0.001). The hemodynamic parameters were comparable and no side effects were noted among the three groups., Conclusion: IA bupivacaine with adjuvants prolongs duration and improves quality of postoperative analgesia as compared to bupivacaine alone., Competing Interests: There are no conflicts of interest.

Selective oxidation of CO to CO2 using metallic or alloy nanoparticles as catalysts can solve two major problems of energy requirements and environmental pollution. Achieving 100% conversion efficiency at a lower temperature is a very important goal. This requires sustained efforts to design and develop novel supported catalysts containing alloy nanoparticles. In this regard, the decoration of nanoalloys with graphene, as a support for the catalyst, can provide a novel structure due to the synergic effect of the nanoalloys and graphene. Here, we demonstrate the effect of nano-PdPt (Palladium-Platinum) alloys having different morphologies on the catalytic efficiency for the selective oxidation of CO. Efforts were made to prepare different morphologies of PdPt alloy nanoparticles with the advantage of tuning the capping agent (PVP - polyvinyl pyrollidone) and decorating them on graphene sheets via the wet-chemical route. The catalytic activity of the G-PdPt hybrids with an urchin-like morphology has been found to be superior (higher % conversion at 135 °C lower) to that with a nanoflower morphology. The above experimental observations are further supported by molecular dynamics (MD) simulations.

The majority of human mild traumatic brain injuries (mTBI; 70%) lack radiological evidence of injury, yet may present long term cognitive, and behavioral dysfunctions. With the hypothesis of evident damaged neural tissue and immunological consequences during acute phase of mTBI, we used closed skull weight-drop TBI model to address human mTBI condition. Serum cytokines (TNF-α, IL-10) and glial fibrillary acidic protein (GFAP) expression were examined at day 0 (control, pre-injury), 4h, day 1, day 3 and day 5 post injury (PI). Diffusion tensor imaging (DTI) was performed at similar timepoints to identify neuroinflammation translation into imaging abnormalities and monitor injury progression. DTI indices including mean diffusivity (MD), radial diffusivity (RD), fractional anisotropy and axial diffusivity values were quantified from cortex (CTX), hippocampus and corpus callosum regions. One way ANOVA showed significant increase in TNF-α at 4h and IL-10 at day 1 PI as compared to control. GFAP(+) cells were significantly increased at day 3 and day 5 as compared to control in CTX. Repeated measures ANOVA revealed significant decreases in MD, RD values in CTX at day 3 and day 5 as compared to day 0. A significant, inverse correlation was observed between cortical MD (r=-0.74, p=0.01), AD (r=-0.60, p=0.03) and RD (r=-0.72, p=0.01) values with mean GFAP(+) cells in the cortical region. These findings suggest that mTBI leads to elevated cytokine expression and subsequent hypertrophy of astrocytic processes. The increased numbers of reactive glial cells contribute diffusion restrictions in the CNS leading to reduced MD and RD values. These findings are in line with the deficits and pathologies associated with clinical mTBI, and support the use of mTBI model to address pathology and therapeutic options., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Autoxidation of pyrogallol in alkaline medium is characterized by increases in oxygen consumption, absorbance at 440 nm, and absorbance at 600 nm. The primary products are H2O2 by reduction of O2 and pyrogallol-ortho-quinone by oxidation of pyrogallol. About 20 % of the consumed oxygen was used for ring opening leading to the bicyclic product, purpurogallin-quinone (PPQ). The absorbance peak at 440 nm representing the quinone end-products increased throughout at a constant rate. Prolonged incubation of pyrogallol in alkali yielded a product with ESR signal. In contrast the absorbance peak at 600 nm increased to a maximum and then declined after oxygen consumption ceased. This represents quinhydrone charge-transfer complexes as similar peak instantly appeared on mixing pyrogallol with benzoquinones, and these were ESR-silent. Superoxide dismutase inhibition of pyrogallol autoxidation spared the substrates, pyrogallol, and oxygen, indicating that an early step is the target. The SOD concentration-dependent extent of decrease in the autoxidation rate remained the same regardless of higher control rates at pyrogallol concentrations above 0.2 mM. This gave the clue that SOD is catalyzing a reaction that annuls the forward electron transfer step that produces superoxide and pyrogallol-semiquinone, both oxygen radicals. By dismutating these oxygen radicals, an action it is known for, SOD can reverse autoxidation, echoing the reported proposal of superoxide:semiquinone oxidoreductase activity for SOD. The following insights emerged out of these studies. The end-product of pyrogallol autoxidation is PPQ, and not purpurogallin. The quinone products instantly form quinhydrone complexes. These decompose into undefined humic acid-like complexes as late products after cessation of oxygen consumption. SOD catalyzes reversal of autoxidation manifesting as its inhibition. SOD saves catechols from autoxidation and extends their bioavailability.

There are several published reports on the prevalence of low vitamin D levels in otherwise healthy Indian population. Vitamin D deficiency has shown variable effect on muscle performance and strength but there is paucity of data on the effect of vitamin D deficiency on muscle energy metabolism. The present study was proposed to investigate the influence of severe vitamin D deficiency on high-energy metabolite levels in resting skeletal muscle and thereafter, monitor the response after vitamin D supplementation using ³¹P magnetic resonance spectroscopy (MRS). Study was conducted on 19 otherwise healthy subjects but with low serum 25(OH)D levels (<5 ng/ml). Subjects were supplemented with cholecalciferol at a dose of 60,000 IU/week for 12 weeks. MRS measurements of inorganic phosphate (Pi), phosphocreatine (PCr), phosphodiester (PDE) and ATP of the calf muscle were taken pre- and post-vitamin D supplementation. The study revealed significantly increased PCr/Pi ratio and decreased [Pi] and PDE/ATP ratio with raised serum 25(OH)D levels after 12 weeks of supplementation. The study indicates that serum 25(OH)D level plays an important role in improving the skeletal muscle energy metabolism and vitamin D deficiency might be one of the primary reasons for prevalence of low PCr/Pi ratio and high PDE values in normal Indian population as reported earlier. The findings of this preliminary study are highly encouraging and warrant further in-depth research, involving larger number of subjects of different age groups, regions and socio-economic sections of the society to further strengthen a correlation between vitamin D levels and muscle energy metabolism.

Background: Subclinical hypothyroidism (sHT) is considered to be a milder form of thyroid dysfunction. Few earlier studies have reported neuromuscular symptoms as well as impaired muscle metabolism in sHT patients., Aim/objective: In this study we report our findings on muscle bioenergetics in sHT patients using phosphorous magnetic resonance spectroscopy (31P MRS) and look upon the possibility to use 31P MRS technique as a clinical marker for monitoring muscle function in subclinical thyroid dysfunction., Subjects and Methods: Seventeen normal subjects, 15 patients with sHT, and 9 patients with hypothyroidism performed plantar flexion exercise while lying supine in 1.5 T magnetic resonance scanner using custom built exercise device. MR Spectroscopy measurements of inorganic phosphate (Pi), phosphocreatine (PCr), and ATP of the calf muscle were taken during rest, at the end of exercise and in the recovery phase. PCr recovery rate constant (kPCr) and oxidative capacity were calculated by monoexponential fit of PCr vs time (t) at the beginning of recovery., Results: We observed that changes in some of the phosphometabolites (increased phosphodiester levels and Pi concentration) in sHT patients which were similar to those detected in patients with hypothyroidism. However, our results do not demonstrate impaired muscle oxidative metabolism in sHT patients based upon PCr dynamics as observed in hypothyroid patients., Conclusions: 31P MRS-based PCr recovery rate could be used as a marker for monitoring muscle oxidative metabolism in sub clinical thyroid dysfunction.

Thallium (Tl) is a toxic heavy metal and its exposure to the human body causes physiological and biochemical changes due to its interference with potassium-dependent biological reactions. A high-resolution (1)H NMR spectroscopy based metabonomic approach has been applied for investigating acute biochemical effects caused by thallium sulfate (Tl(2)SO(4)). Male strain A mice were divided in three groups and received three doses of Tl(2)SO(4) (5, 10 and 20 mg kg(-1) b.w., i.p.). Urine samples collected at 3, 24, 72 and 96 h post-dose time points were analyzed by (1)H NMR spectroscopy. NMR spectral data were processed and analyzed using principal components analysis to represent biochemical variations induced by Tl(2)SO(4). Results showed Tl-exposed mice urine to have distinct metabonomic phenotypes and revealed dose- and time-dependent clustering of treated groups. The metabolic signature of urine analysis from Tl(2)SO(4)-treated animals exhibited an increase in the levels of creatinine, taurine, hippurate and β-hydroxybutyrate along with a decrease in energy metabolites trimethylamine and choline. These findings revealed Tl-induced disturbed gut flora, membrane metabolite, energy and protein metabolism, representing physiological dysfunction of vital organs. The present study indicates the great potential of NMR-based metabonomics in mapping metabolic response for toxicology, which could ultimately lead to identification of potential markers for Tl toxicity., (Copyright © 2011 John Wiley & Sons, Ltd.)

Purpose: Radiation exposure induces change in many biological compounds. It is important to assess the physiological and biochemical response to an absorbed dose of ionising radiation due to intentional or accidental event and to predict medical consequences for medical management. In the present study, nuclear magnetic resonance (NMR) spectroscopy-based metabolic profiling was used in mice serum for identification of radiation-induced changes at metabolite level., Materials and Methods: Mice were irradiated with 3, 5 and 8 Gray of γ-radiation dose and serum samples collected at day 1, 3 and 5 post irradiation were analysed by proton nuclear magnetic resonance (¹H NMR) spectroscopy. ¹H NMR spectra of serum were analysed by pattern recognition using principal component analysis., Results: Irradiated mice serum showed distinct metabonomic phenotypes and revealed dose- and time-dependent clustering of irradiated groups. ¹H NMR spectral analysis exhibited increased lactate, amino acids, choline and lipid signals as well as decreased glucose signals. These findings indicate radiation-induced disturbed energy, lipid and protein metabolism., Conclusions: The information obtained from this study reflects multiple physiological dysfunctions. The study promises the application of NMR-based metabonomics in the field of radiobiology, for development of metabolic-based markers for screening of risk populations and medical management in these cases.

A systematic study on the water-intake capacity of the microemulsion formed using a catanionic surfactant (synthesized by taking equimolar mixture of acid and amine) with varying hydrocarbon chain length of the acid has been carried out. A decrease in the water-intake capacity with increase in the chain length was observed. Shorter chain length of co-surfactant (1-butanol compared to 1-octanol) led to higher water-intake capacity of microemulsions which may also be attributed to the high hydrophilic-lipophilic balance (HLB) of 1-butanol. Three new microemulsions based on catanionic surfactants have been used to synthesize quantum dots of CdS. The size of CdS quantum dots decreased with increase in chain length of the acid component of the catanionic surfactant., (Copyright © 2010 Elsevier Inc. All rights reserved.)

It is generally assumed that men display greater strength and muscle capacity than women. However, previous biochemical and histological studies have shown that men have greater capacity for anaerobic metabolism and women have higher or similar oxidative metabolism. Therefore, in the present study, we estimated oxidative capacity of gastrocnemius muscle and compared in Indian men and women using non-invasive in vivo 31P magnetic resonance spectroscopy (MRS). Healthy subjects (8 young males and 9 females, age-matched) performed plantar flexion exercise within a magnet and MRS measurements of inorganic phosphate (Pi), phosphocreatine (PCr), ADP, and pH of the calf muscles were carried out using a 1.5 T whole-body MRI system. PCr values during recovery were fitted to an exponential curve, and oxidative capacity was calculated using rate constant (k(PCr)), as an index of oxidative phosphorylation. When men and women were compared for different metabolic ratios, ADP, pH, k(PCr) and oxidative capacity, all parameters turned out to be statistically insignificant. The results showed no gender effect on skeletal muscle oxidative metabolism. The study demonstrated the usefulness of such non-invasive method to indirectly measure the oxidative capacity of the muscle based on PCr recovery.

Previously, we observed that alloxan-induced in vitro cytotoxicity and apoptosis in an insulin secreting rat insulinoma, RIN, cells was prevented by prior exposure to prostaglandin (PG) E(1), PGE(2), PGI(2), PGF(1)(alpha), and PGF(3)(alpha) (P<0.05 compared to alloxan), whereas thromboxane B(2) (TXB(2)) and 6-keto-PGF(1)(alpha) were ineffective. In an extension of these studies, we now report that prior intraperitoneal administration of PGE(1), PGE(2), PGF(1)(alpha), and PGF(3)(alpha) prevented alloxan-induced diabetes mellitus in male Wistar rats, whereas PGI(2), TXB(2), and 6-keto PGF(1)(alpha) were not that effective. PGE(1), PGE(2), PGF(1)(alpha), and PGF(3)(alpha) not only attenuated chemical-induced diabetes mellitus but also restored the antioxidant status to normal range in red blood cells and pancreas. These results suggest that PGE(1), PGE(2), PGF(1)(alpha), and PGF(3)(alpha) can abrogate chemically induced diabetes mellitus in experimental animals and attenuate the oxidant stress that occurs in diabetes mellitus.

In the present study, we studied the effect of various prostaglandins (PGs) on alloxan-induced cytotoxicity to rat insulinoma (RIN) cells. Of all the PGs tested, PGE(1), PGE(2), PGI(2), PGF(1 alpha), and PGF(3 alpha) protected RIN cells from alloxan-induced cytotoxicity (P<0.05 compared to alloxan), whereas thromboxane B(2) and 6-keto-PGF(1 alpha) were not effective. PGE(1) induces a statistically significant increase in the activities of superoxide dismutase and glutathione peroxidase and decrease in lipid peroxides in alloxan-treated RIN cells (P<0.001). PGE(1) restored nitric oxide/lipid peroxide ratio to normalcy, suggesting that PGE(1) suppresses oxidant stress induced by alloxan in RIN cells in vitro. Furthermore, PGE(1) prevented DNA damage and apoptosis induced by alloxan. These results indicate that PGE(1) prevents alloxan-induced cytotoxicity to RIN cells in vitro.

Vegetarians are known to have a low incidence of cardiovascular diseases and lower blood pressure compared to non-vegetarians. The exact cause for this is not known. In the present study, it was found that, in general, vegetarians (female > males) have a higher concentrations of anti-oxidant enzymes: catalase and superoxide dismutase in their RBC membranes and lower levels of plasma lipid peroxides compared to non-vegetarians. Both male and female non-vegetarians were found to have a higher n-3/n-6 ratio compared to vegetarians. These results suggest that vegetarians have a higher anti-oxidant status and low levels of n-3 fatty acids. It remains to be seen whether this alterations in the oxidant and anti-oxidant status and n-3 concentrations explains the lower incidence of cardiovascular diseases and lower blood pressure in vegetarians., (Copyright 2001 Harcourt Publishers Ltd.)

Oxidant stress is believed to be enhanced in patients with diabetes mellitus, which may lead to endothelial dysfunction and the development of atherosclerosis. In diabetes, hyperglycemia drives non-enzymatic glycation and oxidation of proteins and lipids which enhances the formation of advanced glycation end products (AGEs), which may be involved in the pathogenesis of diabetic vascular disease. The macrovascular complications of diabetes seem to be due to enhanced cellular oxidant stress by the interaction of AGEs with their receptor. It would be worthwhile to devise methods to reduce this oxidant stress. In alloxan-induced diabetic rats lipid peroxidation products were increased, while levels of nitric oxide glutathione peroxidase and superoxide dismutase were reduced. Melatonin restored these biochemical abnormalities to normalcy independent of hyperglycemia. This model can be used to study the role of oxidant stress in the development of macrovascular complications in diabetes mellitus.

Exposure to environmental pollutants is known to be harmful to health, in general, and to lungs in particular. In this respect, traffic police are at particular risk due to the nature of their job, since they are exposed to emissions from the vehicles. Here, we show that in the traffic police of Hyderabad city, India, the plasma levels of lipid peroxides are high, whereas the concentrations of the nitric oxide are low. In addition, the levels of various antioxidants in the RBC lysate such as catalase, superoxide dismutase and glutathione peroxidase were found to be low with no significant alteration in plasma ceruloplasmin levels. These results suggest that exposure to air pollutants, a major portion of which is due to emissions from the vehicles, can increase oxidant stress, decrease the levels of antioxidants and nitric oxide. This imbalance in the oxidant/antioxidant system may lead to lung damage and is likely to cause respiratory problems in individuals exposed to air pollution.