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The cardiac cycle
Published in Neil Herring, David J. Paterson, Levick's Introduction to Cardiovascular Physiology, 2018
Neil Herring, David J. Paterson
The volume of blood in a ventricle at the end of its filling phase is called the end-diastolic volume (EDV). The EDV is typically ~120 mL in a standing man (Figure 2.5), and ~150 mL supine. The corresponding end-diastolic pressure (EDP) is just a few mmHg. EDP is a little higher on the left side than on the right (Table 2.1), because the thicker left ventricle wall requires a higher pressure to distend it. Since pressures are higher in the left atrium than right atrium, congenital defects in the atrial septum in neonates usually result in a left-to-right flow of blood. Such defects do not, therefore, deoxygenate the arterial blood or cause ‘blue baby syndrome’.
Pollution assessment and estimation of the percentages of toxic elements to be removed to make polluted drinking water safe: a case from Nigeria
Published in Toxin Reviews, 2023
Johnbosco C. Egbueri, Daniel A. Ayejoto, Johnson C. Agbasi
The NO3− concentrations in the water resources were found to be below the standard limit (10–15 mg/L) set by NIS (2007) and the WHO (2017), ranging from 0 to 18.481 mg/L, with an average of 1.962 mg/L. This is likely due to the excessive use of nitrate fertilizer or other agricultural practices in the surrounding agricultural lands, as well as significant surface runoff from agricultural fields to wetlands. Anthropogenic sources such as poor management of organic wastes, sewage, and nitrogen-rich fertilizers are frequently blamed for NO3 pollution, which usually results in an outbreak of methemoglobinemia (blue-baby syndrome), goiter, and gastric cancer (Karanth 1987, Fewtrell 2004, BIS (Bureau of Indian Standards) 2012, Wagh et al.2017, 2019, Egbueri 2019, Latif et al.2020, Sahoo and Khaoash 2020). As a result, it is recommended that the hygiene of the environment in these areas be improved. In general, because of their high concentrations, several PTAs have been found to represent a substantial health concern to water users around the world. The PTAs chosen for this investigation, however, were determined to be moderate in general. All of the PTAs were found to be below their respective criteria, according to the data (Table 1).
Hydrogeochemical characterization, multi-exposure deterministic and probabilistic health hazard evaluation in groundwater in parts of Northern India
Published in Toxin Reviews, 2023
Herojeet Rajkumar, Pradeep K. Naik, Gagandeep Singh, Madhuri Rishi
NO3- contaminant in groundwater is a worldwide environmental concern due to its unique properties, such as high movability and solubility rate, stable oxidative state in water and associated health risks (WHO 2008, Zhai et al.2017, He et al. 2022a). Groundwater pollution due to NO3- is widely reported in various countries, namely in Loess plateau, Northwest China (Li et al.2019b), Matanza-Riachuelo River Basin, Argentina (Ceballos et al.2021), Weining plain and Yinchuan plain, Northwest China (He et al.2022a, 2022b), Donsheng district, Inner Mongolia (Feng et al.2020), Gorveh-Dehgelan, Western Iran (Rahmati et al.2015), Catalan Region, Spain (Carrey et al.2021) and Guanzhong plain, China (Wang and Li 2022). In India, ∼118 million people consume water with NO3- content 45–100 mg/L, and ∼108 million people drink water containing NO3- level >100 mg/L (Rai 2003, Sangwan et al.2021). Anthropogenic activities, such as application of N-chemical fertilizers (Huang et al.2011), excreta from animals farm (Minet et al.2017, Zhang et al.2018), urban runoff (Lapworth et al.2017), landfill leachate (Rao et al.2021), wastewater irrigation (Elisante and Muzuka 2017) and discharge of untreated municipal, sewage and industrial effluents (Herojeet et al.2016, He et al. 2022a), are the leading causes for NO3- loads. The acute toxicity of NO3- is often encountered even though the concentration level for drinking water is below 45 mg/L in infants (<1 year) and children by “blue baby syndrome” (Skold et al. 2011, BIS 2012). Long-term exposure to NO3- has chronic effects on human health, such as non-Hodgkin lymphoma, nitrosamines, and multiple sclerosis (Fabro et al.2015, Wongsanit et al.2015). Therefore, the health hazard risks of such ions are still concerns to infants and children even at low concentration due to exposure dose, sensitivity and weak tolerance limit (Adimalla and Qian 2019).
Cassava toxicity, detoxification and its food applications: a review
Published in Toxin Reviews, 2021
Anil Panghal, Claudia Munezero, Paras Sharma, Navnidhi Chhikara
Anti-nutritional factors are generated in food substances during normal metabolism of spices and have the ability to alter the digestibility of other nutrients. Cassava contains lots of anti-nutrients e.g. nitrates, phytates, tannins, oxalate, and saponins. Phytic acid is the main site for storage of phosphorus compound in plants and are present in cassava roots (624 mg/100 g) (Marfo 1990). The negatively charged phosphates in phytic acids strongly bind to metallic cations of iron, calcium, potassium, manganese, magnesium, and zinc, making these metals insoluble and altering their availability (Bohn et al.2008). Nitrates are present both in leaf and roots but leaf contain significantly higher amount (43–310 mg/100 g/dw) (Wobeto et al.2007). The well-known harmful effect of nitrate is the ability to react with hemoglobin to form methemoglobin and nitrate. Subsequently, the oxygen transport is altered leading to death and condition known as methemoglobinemia or blue baby syndrome. The toxic dose for methemoglobin formation ranges from 33–350 mg nitrate ion/kg body weight, especially in infants. The polyphenols (tannins) in leaves ranges from 2.1 to 120 mg/100 g/dw (Wobeto et al.2007). Processing treatments like sun drying, oven drying, steaming, shredding, and steeping of cassava leaves decreases polyphenols but 50–60% will be retained (Fasuyi 2005). Oxalates are anti-nutrients present in leaves in the range of 1.35–2.88 mg/100 g/dw (Wobeto et al.2007). Oxalic acid combines with calcium and form calcium oxalate complex in the intestinal lumen resulting in calcium unavailablity and kidney stones. Saponins are also present in cassava, their range in the leaves is 1.74–4.73 mg/100 g/dw (Wobeto et al.2007). Saponins have the ability of breaking erythrocytes due their interaction with cholesterol of erythrocyte membrane. Saponins can also break cells found in the intestinal mucosa and subsequently affect nutrient absorption. Saponins have hypocholesterolemic effect also by binding with cholesterol to prevent its absorption or bind with bile acids to prevent the circulation and promote excretion (Liwa et al.2017). These anti-nutrient factors can be reduced or eliminated by using different methods viz., soaking, boiling, pressure cooking, roasting, microwave heating, and fermentation (Chhikara et al. 2018).