► Alkalosis impairs cortical GABAergic cells in response to excitatory synaptic inputs. ► Alkalosis impairs the abilities of encoding spikes at these GABAergic neurons. ► Neuronal impairment is ...associated with the increases of spike refractory periods and thresholds. ► The final targets of alkalosis are voltage-gated sodium channels and glutamate receptor-channels.
Acid–base imbalance leads to pathological cognition and behaviors in the clinical practices. In the comparison with acidosis, the cellular mechanisms underlying alkalosis-induced brain dysfunction remain unclear. By using electrophysiological approach, we investigated the influences of high extracellular pH environment on cortical GABAergic neurons in terms of their responsiveness to synaptic inputs and their ability to produce action potentials. Artificial cerebral spinal fluid in high pH impairs excitatory synaptic transmission and spike initiation in cortical GABAergic neurons. The alkalosis-induced dysfunction of GABAergic neurons is associated with the decrease of receptor responsiveness and the increases of spike refractory periods and threshold potentials. Our studies reveal that alkalosis impairs cortical GABAergic neurons and subsequently deteriorate brain functions. The molecular targets for alkalosis action include glutamate receptor-channels and voltage-gated sodium channels on GABAergic neurons.
NaNO3 and other alkali nitrate salts, which are present in the molten state during use, have been described as facilitators or catalysts for CO2 absorption by both MgO and MgO-containing double ...salts. Although MgO exhibits a high capacity (exceeding 70 wt %), its regenerability in multicycle tests shows a significant loss of capacity with cycle number prior to lining out. On the other hand, the MgO–Na2CO3 double salt shows a lower (∼16 wt %) but stable capacity over multiple cycles under pressure swing operation. The purpose of this paper is to elaborate on the concept of molten salts as catalysts for CO2 absorption by MgO, and extend these observations to the MgO-containing double salt oxides. We will show that the phenomena involved with CO2 absorption by MgO and MgO-based double salts are similar and general, but with some important differences. This paper focuses on the following key concepts: (i) identification of conditions that favor or disfavor participation of isolated MgO during double salt absorption, and investigation of methods to increase the absorption capacity of double salt systems by including MgO participation; (ii) examination of the relationship between CO2 uptake and melting point of the promoter salt, leading to the recognition of the role of premelting (surface melting) in these systems; and (iii) extension of the reaction pathway model developed for the MgO–NaNO3 system to the double salt systems. This information advances our understanding of MgO-based CO2 absorption systems for application with precombustion gas streams.
► We describe Na2CO3-promoted MgO as a CO2 absorbent in the range of 300–470°C. ► The material shows a regenerable capacity of 3.4mmol/g both through TSA and PSA. ► Na2Mg(CO3)2 double salt has a free ...energy of formation of approximately −122kJ/mol. ► The absorbent is predicted to be able to remove 85–90% of CO2 in pre-combustion application. ► NaNO3 is found to have an important role in facilitating the CO2 absorption of the double salt.
Absorption and desorption of carbon dioxide on Na2CO3-promoted MgO have been studied at temperatures compatible with warm gas cleanup (300–470°C) from a pre-combustion syngas. The absorbents are synthesized through the formation and activation of the precipitate resulting from the addition of sodium carbonate to an aqueous solution of magnesium nitrate. The absorbent, which comprises MgO, Na2CO3 and residual NaNO3 after activation, forms the double salt Na2Mg(CO3)2 on exposure to CO2. The thermodynamic properties of the double salt, obtained through computational calculation, predict that the preferred temperature range for absorption of CO2 with the double salt is significantly higher compared with MgO. Faster CO2 uptake can be achieved as a result of this higher temperature absorption window. Absorption tests indicate that the double salt absorbent as prepared has a capacity toward CO2 of 15wt.% (3.4mmol CO2/g absorbent) and can be easily regenerated through both pressure swing and temperature swing absorption in multiple-cycle tests. Thermodynamic calculations also predict an important effect of CO2 partial pressure on the absorption capacity in the warm temperature range. The impurity phase, NaNO3, is identified as a key component in facilitating CO2 absorption by these materials. The reason for reported difficulties in reproducing the performance of these materials can be traced to specific details of the synthesis method, which are reviewed in some detail.
OBJECTIVETo evaluate the impact of Triangle theory-based continuity of care on postoperative malnutrition in pancreatic cancer patients.METHODSWe retrospectively analyzed the data from 184 patients ...with pancreatic cancer admitted to The Second People's Hospital of Lanzhou City from January 2020 to May 2023. Patients were divided into a control group receiving conventional care (n = 114) and a study group receiving Triangle theory-based care (n = 70). Postoperative nutritional status and prognosis were compared between the two groups. Nutritional indexes included serum total protein (STP), albumin (ALB), and hemoglobin (HB). Self-care ability was assessed using the Exercise of Self-care Agency (ESCA). Quality of life was measured using the Quality-of-Life Questionnaire for Pancreatic Cancer 26 (QLQ-PAN-26), and the incidence of malnutrition was evaluated using the Patient-Generated Subjective Global Assessment (PG-SGA). Multifactorial logistic regression was applied to analyze risk factors for malnutrition.RESULTSAt ten days post-operation, the study group showed significantly better nutritional levels (P < 0.05). After three months, the, study group also exhibited superior self-care ability and quality of life scores (all P < 0.001). The incidence of malnutrition was 42.39%. Independent risk factors for malnutrition included routine care (OR = 3.459), operation time ≥ 90 min (OR = 2.277), intraoperative bleeding ≥ 200 mL (OR = 2.590), postoperative day 1 ALB < 37.5 g/L (OR = 3.975), and HB < 95.5 g/L (OR = 6.068).CONCLUSIONTriangle theory-based continuity of care significantly improves nutritional status and quality of life in postoperative pancreatic cancer patients, demonstrating its potential for broader clinical use.
Sand is a granular, porous material with high compressibility, which influences the penetration process. According to the sand responses at different penetration velocities, the P-alpha equation of ...state and Mohr-Coulomb Tresca-limit yield criterion are used to describe the constitutive behavior. In the plastic region, the spherical cavity-expansion model is applied, and in the fluid-like region the hydrodynamic model with compressibility considered is applied based on the Alekseevskii-Tate model. Comparison with experimental results shows that the model is suitable for calculating sand penetration depths for rigid and erosive projectiles. Initial sand density affects penetration dissimilarly for different striking velocities, and a critical striking velocity exists. The compressibility should be considered with P-alpha equation of state below this critical striking velocity, and otherwise the fully compacted density can directly be used to calculate the penetration depth. Projectile dynamic yield strength influences penetration strongly. For an erosive projectile, the penetration depth and change in residual projectile length vary with the projectile dynamic yield strength.
Pressure at projectile-target interface and sand density changes with penetration velocity for several values of initial sand density. Display omitted
•At high enough velocity, a fluid-like region appears in sand, and also projectile.•We establish a hydrodynamic model with compressibility considered for sand impact.•In our model, both rigid and erosive projectiles are studied.•Our model's validity is demonstrated by experiments of rigid and erosive projectiles.•Initial sand density affects penetration differently at diverse striking velocities.
Molten salts facilitate the reaction of CO2 with MgO by providing an alternate pathway to traditional gas‐solid reactions. Molten salts partially dissolve bulk MgO and provide activated species ...accessible to CO2 at gas‐solid‐liquid triple phase boundaries. This methodology is also applicable to other basic metal oxides and molten salts, inspiring the design of new absorbent systems.
Cerebral ischemic stroke is one of the most prevalent diseases in senior individuals. Its therapeutical strategies include anticoagulation, thrombolysis and cell protection. Tissue-type plasminogen ...activator (t-PA) that interacts with thrombin for the lysis of thrombosis is widely used to treat stroke patients in early stage. The mechanism of action of t-PA is not clear. Here, we report a novel role of t-PA in protecting blood–brain barrier and its potential mechanisms. In a model of the blood–brain barrier with human umbilical vascular epithelium cells, we found that t-PA in low concentrations prevented the impairment of the blood–brain barrier as a result of oxygen and glucose deprivation. This protection was fulfilled by strengthening the junctions among vascular endothelia and by upregulating the productions of vascular endothelium growth factor and of zonula occludens-1. Therefore, t-PA may strengthen the junctions of vascular endothelia in the blood–brain barrier to improve the microenvironment of brain cells and, in turn, the outcome of stroke patients.
Absorption and desorption of carbon dioxide on Na sub(2)CO sub(3)-promoted MgO have been studied at temperatures compatible with warm gas cleanup (300-470 degree C) from a pre-combustion syngas. The ...absorbents are synthesized through the formation and activation of the precipitate resulting from the addition of sodium carbonate to an aqueous solution of magnesium nitrate. The absorbent, which comprises MgO, Na sub(2)CO sub(3) and residual NaNO sub(3) after activation, forms the double salt Na sub(2)Mg(CO sub(3)) sub(2) on exposure to CO sub(2). The thermodynamic properties of the double salt, obtained through computational calculation, predict that the preferred temperature range for absorption of CO sub(2) with the double salt is significantly higher compared with MgO. Faster CO sub(2) uptake can be achieved as a result of this higher temperature absorption window. Absorption tests indicate that the double salt absorbent as prepared has a capacity toward CO sub(2) of 15 wt.% (3.4 mmol CO sub(2)/g absorbent) and can be easily regenerated through both pressure swing and temperature swing absorption in multiple-cycle tests. Thermodynamic calculations also predict an important effect of CO sub(2) partial pressure on the absorption capacity in the warm temperature range. The impurity phase, NaNO sub(3), is identified as a key component in facilitating CO sub(2) absorption by these materials. The reason for reported difficulties in reproducing the performance of these materials can be traced to specific details of the synthesis method, which are reviewed in some detail.
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