•Corrosion behaviour of steel is different depending on the kind of metal cations in fresh water.•Metal cations that have large X are incorporated in passive films of the steel.•The corrosion rate of ...mild steel can be estimated by using “corrosion inhibitory effect of cations, Y”.s.
The effects of metal cations on corrosion of mild steel in model fresh water were investigated by electrochemical techniques and immersion tests. Analysis of X-ray photoelectron spectroscopy showed that metal cations have large hardness of cations, X, are incorporated in passive films. The electrochemical and immersion results showed that X is not suitable as a corrosion indicator of mild steel. A novel corrosion indicator, “corrosion inhibitory effect of cations Y”, that consists of X and molar volume ratio, ΔV, is proposed, and it is shown that the novel indicator can estimate the corrosion rate of mild steel in fresh water.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
•Corrosion rate of SUS304 can be explained by metal cation hardness, X, which is calculated by HSAB concept.•From the XPS results, metal cations with large X form a layer by incorporating in the ...passive films.•The metal cation layer inhibits the corrosion of SUS304 in 0.5 M Cl− aqueous solution.
The corrosion characteristics of SUS304 exposed to 0.5 M Cl− aqueous solution containing different metal cations were studied with immersion tests, surface analysis and electrochemical tests. The mechanism of corrosion with metal cations was clarified by the XPS analysis results together with the hard and soft acid and base (HSAB) concept and the passive films structure. It is supposed that metal cations with large hardness make a layer by chemical bonding with the passive films. The passive films are protected by the metal cation layer from Cl− attack, and consequently corrosion reactions are inhibited.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The influences of metal cations on the corrosion of mild steel in 10 mM Cl- aqueous solutions were investigated by electrochemical techniques and immersion tests. Immersion tests and electrochemical ...impedance spectroscopy (EIS) results showed that Zn2+ has a significant effect on corrosion Inhibition. Surface morphological inspection also showed the smooth surface of specimen Immersed in Zn2+ containing solution. Analysis of X-ray photoelectron spectroscopy showed that Zn2+ was incorporated in the oxide films by making a strong bond. It is supposed that Zn2+ forms a very effective shielding film which can inhibit the electrochemical reactions, and consequently lowers the corrosion rate.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Healthcare workers who are exposed to coronavirus disease 2019 are psychologically distressed. This study aimed to evaluate the mental health outcomes of hospital workers 2 years after the outbreak ...of coronavirus disease 2019 and to identify changes in the stress of hospital workers and predicted risk factors.
This survey was conducted 2 years after the initial evaluation performed under the first emergency declaration of the coronavirus disease 2019 pandemic among hospital workers at the same hospital in an ordinance-designated city in Japan from June to July 2022. Sociodemographic data, 19 stress-related question responses, the Impact of Event Scale-Revised, and the Maslach burnout inventory-general survey were collected. Multiple regression models were used to identify factors associated with each of the mental health outcomes 2 years after the coronavirus disease 2019 outbreak.
We received 719 valid responses. Between 2020 and 2022, hospital workers' anxiety about infection decreased, whereas their exhaustion and workload increased. Multiple regression analysis revealed that 2 years after the coronavirus disease 2019 outbreak, nurses and young people were at a higher risk of experiencing stress and burnout due to emotional exhaustion, respectively.
This is the first study to examine the long-term stress of hospital workers measured in Japan. Exhaustion and workload were worsened 2 years into the pandemic. Therefore, health and medical institutions should continuously monitor the physical and psychological health of staff members.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•Among COVID-19 patients, delirium and encephalopathy have been observed.•Cytokine storms and CNS damage result from viral induced hyperinflammation.•BBB failure and elevated microglia activation may ...be signs of COVID encephalopathy.•COVID-19 can result in cognitive impairment, starting with delirium.
The coronavirus disease (COVID-19) continues to spread worldwide. It has a high rate of delirium, even in young patients without comorbidities. Infected patients required isolation because of the high infectivity and virulence of COVID-19. The high prevalence of delirium in COVID-19 primarily results from encephalopathy and neuroinflammation caused by acute respiratory distress syndrome (ARDS)-associated cytokine storm. Acute respiratory distress syndrome has been linked to delirium and psychotic symptoms in the subacute phase (4 to 12 weeks), termed post-acute COVID-19 syndrome (PACS), and to brain fog, cognitive dysfunction, and fatigue, termed “long COVID,” which persists beyond 12 weeks. However, no review article that mentions “COVID-19 delirium” have never been reported.
This narrative review summarizes data on delirium associated with acute severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and related neurological symptoms of persistent post-infection illness (PACS or long COVID) after persistence of cognitive dysfunction. Thus, we describe the pathophysiological hypothesis of COVID-19 delirium and its continuation as long COVID. This review also describes the treatment of delirium complicated by COVID-19 pneumonia.
SARS-CoV-2 infection is associated with encephalopathy and delirium. An association between COVID-19 infection and Alzheimer's disease has been suggested, and studies are being conducted from multiple facets including genetics, cytology, and postmortem study.
This review suggests that COVID-19 has important short and long-term neuropsychiatric effects. Several hypotheses have been proposed that highlight potential neurobiological mechanisms as causal factors, including neuronal-inflammatory pathways by cytokine storm and cellular senescence, and chronic inflammation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In order to clarify the effect of metal cations (Zn2+, Mg2+, Na+) in aqueous solution on hydrogen absorption into iron, the amount of hydrogen absorption from iron surface was measured by ...electrochemical tests with a laser ablation. Moreover, in order to obtain the basic mechanism of hydrogen absorption with adsorption of metal cation, we obtained the adsorption potential of the adsorbed atom and the electronic state around the adsorbed atom using first principles calculations. Peak value of permeation current and the time until the current reached the peak value decreased and elongated in the order of NaCl, MgCl2, and ZnCl2 solutions. Also, by first-principles calculations adsorption strength of each metal atom increased in the order of Na < Mg < Zn. It was suggested that dissolution of Fe is inhibited due to formation of dense metal layer in the solution including the metal cation which has large adsorption strength to Fe surface like Zn, and finally permeation current may have been reduced.
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