Hair Cosmetics and Cosmeceuticals
Rubina Alves, Ramon Grimalt in Techniques in the Evaluation and Management of Hair Diseases, 2021
They are detergent molecules which are classified according to the electric charge as either anionic, cationic, amphoteric (zwitterionic), or nonionic. The most widely used include lauryl sulfate, ammonium lauryl ether sulfate, and ammonium lauryl sulfate which belongs to the anionic group (group 1) [4]. They strongly remove dirt and sebum from the hair and scalp, in particular, one end of the molecule has a negative electrical charge and is soluble in water, so it does not blend with oils. The other end is soluble in oil and grease and does not blend with water. These molecules surround the fragments of grease localized on hair and scalp: the oil soluble parts go into the grease and the water-soluble parts remain located outward, forming a hydrophilic mass that is totally negatively charged. The surface of the hair shaft has negative charges, which tend to force the mass negative charges apart. The result is that the surface tension between water and grease is reduced and so the dirt comes off from the hair. In addition, surfactants produce foam, which incorporates the dirt, so that it cannot be re-deposited on the hair and scalp.
Asphyxia
Kevin L. Erskine, Erica J. Armstrong in Water-Related Death Investigation, 2021
Hydrogen sulfide is a gas originating from the natural environment, organic decomposition, and industry. Specific sources include sewers, septic tanks, the manufacture of petroleum-containing products and paper, natural gas, and volcanoes.8 It is commonly described as having a rotten egg odor. At higher concentrations in the ambient environment and with prolonged inhalation, its odor becomes undetectable due to paralysis of the olfactory nerves, and respiratory impairment and unconsciousness may ensue.8 Due to the occupational hazards and past reports of deaths, OSHA regulations restrict the amount of exposure and require training, equipment for detection of the gas, and the use of respiratory protective equipment.13,14 The action of H2S is at the cellular level, similar to cyanide. During the scene investigation, blackening of metal objects, including coins, may be noted. At autopsy, a greenish discoloration of the tissues, in addition to the characteristic odor, may be noted. Prompt toxicological testing may reveal elevated sulfate ion or thiosulfate levels.8
Ecology
Paul Pumpens in Single-Stranded RNA Phages, 2020
Furthermore, a thorough alkylation analysis was performed on the phage R17 with two groups of alkylating agents: (i) methyl methanesulfonate and dimethyl sulfate and (ii) N-methyl-N-nitrosourea and N-methyl-N′-nitro-N-nitrosoguanidine (Shooter 1974b). The extent of biological inactivation by these alkylating agents was explained by the breaks in the RNA chain, which resulted from hydrolysis of phosphotriesters formed in the alkylation reactions and the rate of hydrolysis increased rapidly as the pH was raised (Shooter et al. 1974a). The mechanism of the biological inactivation of the phage R17 by ethyl methanesulfonate and N-ethyl-N-nitrosourea was unveiled (Shooter and Howse 1975). Then, a group of eight alkylating agents was involved in the R17 studies (Shooter 1975) and acetoxy-dimethylnitrosamine was tested (Shooter and Wiessler 1976).
In silico prediction of post-translational modifications in therapeutic antibodies
Published in mAbs, 2022
Shabdita Vatsa
Tyrosine sulfation is an enzymatic modification that is catalyzed by tyrosylprotein sulfotransferases (TPSTs). During sulfation, a sulfate group is attached to the hydroxyl group of tyrosine residues.111 Tyrosine sulfation has been reported for a few monoclonal and bispecific antibodies.111–114 Sulfation of mAbs can occur in Chinese hamster ovary (CHO) cells during the cell culture. The degree of tyrosine sulfation in CHO cells varies due to differential expression of phosphoadenosine-5ʹ-phosphosulfate (PAPS) synthetase and TPST. PAPS synthetase converts ATP to PAPS; TPST transfers the sulfo group from PAPs to tyrosine residues.115 Sulfation in mAbs generates acidic variants,111 but the impact of tyrosine sulfation on the safety and efficacy of therapeutic antibodies has not yet been established.5
Removal of malathion insecticide from aqueous solution by the integration of persulfate process and magnetite nanoparticles loaded on carbon (Fe3O4@CNT) in the presence of ultraviolet radiation
Published in Toxin Reviews, 2022
Malektaj Eskandari makvand, Sima Sabzalipour, Mahboobeh Cheraghia, Neda Orak
Iron is a safe, non-toxic, and inexpensive element. It is noteworthy that the iron residues must be separated into inhomogeneous forms (Fe2+ or Fe3+) and the use of those solvents requires more processing. Nonetheless, inhomogeneous catalysis could be reused, which is an extraordinary advantage compared to the homogeneous form of this substance (Zhu et al.2013). Magnetite (Fe3O4) or divalent and trivalent iron oxide is widely employed as a catalyst in the photocatalysts and Fenton-dependent processes (Guo et al.2010, Huang et al. 2012, Mishra and Chun 2015), which is owing to the high ability of this substance to decompose the hydrogen peroxide and convert it to hydroxyl radical. Moreover, Fe3O4 has shown good stability in the photocatalysis process (Mishra and Chun 2015). In this regard, some superficial reactions of Fe3O4 with persulfate would lead to producing the sulfate radicals based on Equations (2–5) (Ji et al.2013, Oh et al.2015).
Risk of Colorectal Cancer in a Brazilian Population is Differentially Associated with the Intake of Processed Meat and Vitamin E
Published in Nutrition and Cancer, 2022
Radmila Raiani Alves Ribeiro, Isabella Rolim de Brito, Karolline Andrade Souza, Larissa de Castro Souza, Tiago Almeida de Oliveira, Mathias Weller
Data from the present case-control study indicated that a higher intake of processed meat, but not red meat, was associated with an increased risk of CRC. Nitrates and nitrites that are used for the conservation of processed meat produce N-nitroso compounds (NOCs) that are potent carcinogens in the gastrointestinal tract (10). Additionally, inorganic sulfate, which is also used in the preservation of processed meat, is metabolized to hydrogen sulfide (H2S), which is directly associated with an increased risk of CRC because of its carcinogenic properties (10). In a meta-analysis of 21 studies, a high intake of red and unprocessed meat increased the risk of CRC (48). In another meta-analysis of 16 case–control studies and five cohort/nested case–control studies, high intake of red and processed meat was also associated with a significantly increased risk of CRC (49). A recent analysis based on the pooled data of 407,270 participants in three US-based studies also attributed the increased risk of CRC to both higher intake of red and processed meat (50). In the American Cancer Prevention Study II Nutrition Cohort, CRC survivors with consistently high intake of red and processed meat before and after diagnosis had an increased risk of CRC-specific mortality (51).
Related Knowledge Centers
- Dimethyl Sulfate
- Ester
- Oxygen
- Sulfur
- Sulfuric Acid
- Empirical Formula
- Salt
- Oxidation State
- Conjugate
- Tetrahedral Molecular Geometry