General Anesthetics
Sahab Uddin, Rashid Mamunur in Advances in Neuropharmacology, 2020
As a weak anesthetic agent, Nitrous oxide shows consistent anesthetic effects during surgery under hyperbaric situation. It produces marked analgesia at 20% concentrations and sedation at 30% and 80% concentrations. It also produces analgesia and sedation in outpatient dentistry at 50% concentration. Nitrous oxide is often used along with other agents like inhalational anesthetics or intravenous anesthetics. In the body cavity having hollow space, nitrous oxide exchange with N2 as it produces different blood: a gas partition coefficient which is consider as one of the disadvantage of nitrous oxide. The formed nitrous oxide enters into body cavity at a faster rate than escape of nitrogen thereby raising the volume and/or pressure inside the body cavity. The increased pressure and/or pressure causes development of pneumothorax which is fundamentally associated with hindered middle ear, embolus ofair, a hindered bowel loop, an air bubble in inner ocular cavity, a pulmonary bulla, and intracranial air (Brunton et al., 2011; Sharma and Sharma, 2017).
Novel UV Filtering Agents for Next-Generation Cosmetics: From Phytochemicals to Inorganic Nanomaterials
Madhu Gupta, Durgesh Nandini Chauhan, Vikas Sharma, Nagendra Singh Chauhan in Novel Drug Delivery Systems for Phytoconstituents, 2020
UV filtering agents used in cosmetics are known to be capable of minimizing the harmful effects of UV radiations. There are various classes of UV filters based on their chemical nature. However, the mechanism of action of various ingredients can be different at the basic level. One type is physical filters, which reflect (back) a portion of solar radiation, letting only a limited fraction of light cross them and reach the skin. Therefore, physical filters do not directly interact with solar radiation and there is chemical alteration in the UV protective agents after reflecting UV radiations. Some well-known examples of inorganic factors include zinc oxide (ZnO). Second are chemical filters that absorb a portion of solar radiation and use it to achieve a higher quantum energy state. Immediately after, such excess energy is released to the environment in the form of heat, and the chemical filter is again ready to absorb solar energy. A number of antioxidants and phytoextracts can fall in this category of chemical filters. Figure 7.2 represents the basic difference in the mechanism of action of two different categories of UV filters.
Abnormal Red Cell Metabolism
Harold R. Schumacher, William A. Rock, Sanford A. Stass in Handbook of Hematologic Pathology, 2019
Energy for red cell function is dependent on the glycolytic pathways (Fig. 1). Several red cell enzymes which play an active role in glycolysis are critical for red cell function and survival. The major pathway is the Embden-Meyerhof pathway (EMF), in which glucose is broken down to lactose and two molecules of ATP are generated, which are sufficient for the energy needs of the red cell. The second pathway, the hexose monophosphate pathway (HMP), which utilizes about 5–10% of the glucose, is the only source of reduced nicotinamide adenine dinucleotide phosphate (NADPH). NADPH is generated from nicotinamide adenine dinucleotide phosphate (NADP) in the HMP pathway by glucose 6-phosphate dehydrogenase (G6PD). NADPH acts as a coenzyme which converts glutathione (GSSH) to reduced glutathione (GSH). GSH protects the red cell from oxidative injury. Many drugs and organisms produce superoxide anion (O−) and hydrogen peroxide (H2O2). These oxidants can destroy red cells. However, GSH rapidly reduces the oxidant anions, and as long as there is adequate supply of NADPH, enough GSH is available to protect the red cells. Although deficiency of any enzyme in the EMF or HMP can cause hemolytic anemia, the most commonly encountered deficiencies are G6PD deficiency and pyruvate kinase deficiency.
Facile biosynthesis, characterisation and biotechnological application of ZnO nanoparticles mediated by leaves of Cnidoscolus aconitifolius
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2023
Reuben Samson Dangana, Reama Chinedu George, Umulkhayr Oyenike Shittu, Femi Kayode Agboola
It is presumed that metal and metal oxide nanoparticles exposure could cause oxidative stress when exposed to crop plants by generating reactive oxygen species (ROS). In this study, increased activity of SOD was observed (Figure 8) which means there was an increase in the oxidative stress which in turn increases the oxidative enzyme expression. However, studies suggested that the application of NPs at low concentrations was found effective in alleviating various abiotic stresses and enhancing plant growth and development [51,52]. In the case of catalase (Figure 9), there was no significant difference between the two groups treated with NPs and inorganic fertiliser. However, both treated groups showed increase activities of the enzyme as compared with the control group. Other studies have shown NPs to cause oxidative stress by an increase in the activity of antioxidant enzymes that exposure to CuO and ZnO NPs caused oxidative stress in wheat, which was evidenced by increased lipid peroxidation level and oxidised glutathione rate in roots [21,53,54]. As described above, generated ROS radicals act as signalling molecules, thereby activating the plant antioxidant defence mechanism of plants employing both enzymatic agents, such as superoxide dismutase (SOD) and catalase (CAT) and nonenzymatic antioxidants, such as ascorbate, glutathione, phenolics, etc [28].
Dynamics of environmental pollution, socio-economic factors, and total fertility rate in MENA, ECOWAS, and ASEAN regions
Published in Health Care for Women International, 2023
Chigozie Nelson Nkalu
Furthermore, environmental or air pollutants come in the likes of carbon monoxide (CO2), nitrate oxide (NO2), methane emissions (CH4), sulfur dioxide (SO2) and other particulate matter (Carré et al., 2017). Inhalation and ingestion are mostly the common expository routes of environmental or air pollutants, given that ingestion facilitates primarily in the contamination of water and food through air pollution. These pollutants, especially fossil fuel combustion from diesel exhaust, disrupt the endocrine activity, adversely affecting female reproduction health. Besides, the disruptions of endocrine activities by these air pollutants exert metabolic disorder and interferences in the human reproductive health with attending health issues such as obesity and insulin resistance, which severely linked to infertility or fertility issues (Carré et al., 2017).
Distribution, contamination, toxicity, and potential risk assessment of toxic metals in media from Arufu Pb–Zn–F mining area, northeast Nigeria
Published in Toxin Reviews, 2021
Adeniyi J. Adewumi, Temitope A. Laniyan, Phillips R. Ikhane
All laboratory analyses of samples were carried out at the State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Science, Guiyang, China. Prior to analysis, digestion of samples was carried out using Aqua Regia procedure. One gram of samples was weighed using electronic weighing balance and place into Teflon tubes using a mixture of NO3 and HCl in a ratio of 1:3. This was then placed in metallic container for 16 h at temperature of 110 °C and after which they were transferred to a hotplate where the digestate was allowed heat to near dryness after which 5 ml of the acids were added. After a total digestion of samples, the digestates were diluted with ultrapure water at the ratio of 1:50. For the analysis, Agilent 7700 series inductively coupled plasma-mass spectrometry (ICP-MS) was used. Metals analyzed in the soils, stream sediments, and mine tailings were As, Cd, Co, Cr, Cu, Hg, Ni, Pb, Zn, and Fe. For the analysis, high plasma liquid chromatography Agilent 7700 series ICP-MS was used. Standardized samples from the laboratory were measured at interval of 10 samples to serve as quality control for the analysis. Major oxides in the samples were analyzed using X-Ray Fluorescence ARL Quant’x EDXRF spectrometer. Major oxides analyzed include: Al2O3, CaO, CuO, Fe2O3, K2O, MgO, MnO, and LOI. Mineralogical analysis for soils, stream sediments, rocks, and mine-tailings was carried out using ARLTM Equinox 6000 X-Ray diffractometer.
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