Weak Alkaline Research Articles

Measurement of the concentration of hydrogen ions in the mucous membranes of the upper respiratory tract. Mittermaier and Marchionini (Zeitschrift f. Hals-NasenOhren-Heilkunde, 1928. B. 20)

Mittermaier and Marchionini (Zeitschrift f. Hals-NasenOhren-Heilkunde, 1928. B. 20) investigated the state of the mucous membranes and secretions in acute inflammation of the paranasal sinuses, and found a displacement of Pu towards the acidic reaction; so, with acute inflammation of the frontal sinus, Rn 6.63; with severe acute and purulent sinusitis Pn 6.4. With the transition of an acute process into a chronic one, the pH also shifts towards alkalinity; so. polypoidly degenerated mucosa in chronic sinusitis gave Pn = 7.9; These studies have, in addition to the theoretical and practical result, the widely practiced washing of the inflamed sinuses with various solutions receive certain indications, namely: in acute inflammations, the lavages should be performed with weakly alkaline solutions, and for chronic inflammations, with weakly acidic solutions.

Improved clearing method contributes to deep imaging of plant organs

Tissue clearing methods are increasingly essential for the microscopic observation of internal tissues of thick biological organs. We previously developed TOMEI, a clearing method for plant tissues; however, it could not entirely remove chlorophylls nor reduce the fluorescent signal of fluorescent proteins. Here, we developed an improved TOMEI method (iTOMEI) to overcome these limitations. First, a caprylyl sulfobetaine was determined to efficiently remove chlorophylls from Arabidopsis thaliana seedlings without GFP quenching. Next, a weak alkaline solution restored GFP fluorescence, which was mainly lost during fixation, and an iohexol solution with a high refractive index increased sample transparency. These procedures were integrated to form iTOMEI. iTOMEI enables the detection of much brighter fluorescence than previous methods in tissues of A. thaliana, Oryza sativa, and Marchantia polymorpha. Moreover, a mouse brain was also efficiently cleared by the iTOMEI-Brain method within 48 h, and strong fluorescent signals were detected in the cleared brain.

Isolated molybdenum-based microporous POMs for selective adsorption of gases.

Dodecanuclear, icosanuclear and octanuclear porous MOF-like POM materials [MoV12O12(μ2-O)4(μ3-O)12(Htrz)4(trz)4]·nH2O (n = 22, 1; n = 92, 2; Htrz = 1H-1,2,3-triazole), [MoV8O8(μ2-O)12(Htrz)8]½·[MoV12O12(μ2-O)4(μ3-O)12(Htrz)4(trz)4]·44H2O (3), and [MoV8O8(μ2-O)12(Htrz)8]·62H2O (4) have been obtained and well characterized. Higher Mo12 agglomerates have been fabricated in acidic solution, while isolated Mo8 species formed in weak alkaline conditions. Fortuitously, their additive 3 is precipitated in a neutral environment. Structural analyses indicate that there are diversiform pores present in 1-4, which are formed by polyoxometalates (POMs) themselves and intermolecular accumulations, or even induced by free disordered water molecules. Obvious downfield shifts have been found in the solid 13C NMR spectra for the coordinated 1,2,3-triazoles in 1 and 2. In particular, isolated single species of polyoxometalate-based porous framework POMOF 4 can be identified in the solution 13C NMR spectrum and further supported by solid and solution UV-vis spectroscopy. Moreover, gas adsorption tests indicate that 1 is the most promising CO2 adsorbent of these four materials, compared with other common gases O2, H2, CH4 and N2 under different pressures. The peculiarities of this sort of POMOFs, as well as the relationships and interactions with gases, have been discussed.

Adsorption of CO2 by alkali metals and weak alkali rare earth metals supported on aluminum pillared diatomite

In this study, aluminum pillared diatomite loaded with alkali metals and weak alkali rare earth metals was prepared by impregnation method with cheap and abundant diatomite as raw material. Aluminum pillared diatomite loaded with alkali metals Cs, K, Na, Li and aluminum pillared diatomite loaded with weakly alkaline rare earth metals La, Nd, Tm were prepared respectively. Its physicochemical properties were studied by XRPD and N2 adsorption/desorption techniques, and characterized by thermogravimetric analysis, CO2 temperature programmed desorption and FTIR. The results show that the adsorption capacity of 5Cs/Al-PILC for CO2 is the highest, which is 2.355 mmol/g. The specific surface area and porosity of diatomite were improved by aluminum pillared modification, but the specific surface area and micropore content of metal loaded diatomite decreased slightly. The effect of alkalinity is greater than that of micropore amount. The adsorption performance of aluminum pillared diatomite adsorbent is affected by the synergistic effect of specific surface area, total micropore volume and alkalinity. Alkalinity is the main factor affecting the adsorption capacity. The adsorption process of CO2 on the sample is mainly chemical adsorption. The addition of appropriate amount of metal can enhance the alkalinity of the sample, and the adsorbed CO2 exists in the form of bicarbonate and carbonate. The adsorbent made from diatomite has low cost, can be used in industrial production, and has broad development prospects.

Photodegradation of humic acid from the surrounding soils of a sub-alpine Lake Tiancai

溶解性有机质（DOM）是湖泊生态系统的物质循环和能量流动的基础.典型亚高山湖泊DOM的主要来源为流域土壤腐殖酸（外源DOM），其具有较强的光吸收特性，光降解是其重要的转化过程，从而改变碳、氮、磷等物质的存在形式.在气候变暖的背景下，亚高山湖泊中DOM的浓度、pH、溶解氧及太阳辐射都可能发生变化；但这些环境变化对亚高山湖泊DOM光降解过程的影响尚不够清楚.由此本文研究了亚高山湖泊——天才湖（树线下200 m）周边土壤提取的腐殖酸（THA）的光降解过程：首先考察在光源为500 W汞灯、不通气以及pH=8.0条件下THA的降解过程中DOC浓度、有色溶解性有机质（CDOM，以a₂₈₀表征）和荧光溶解性有机质（FDOM）的变化，其后定性比较、定量分析不同光降解条件（pH、载气和光照波段）对THA的光降解过程的影响.结果表明，THA含有4种荧光组分，其中C1~C3均为类腐殖质，占总荧光强度83.64%，C4占比16.36%，为类蛋白质物质.在500 W汞灯的照射下，THA分子量逐渐降低，10 h后DOC浓度降低44.5%，a₂₈₀随光照时间的增加逐渐减少，CDOM含量较初始大幅度下降；而FDOM （以荧光组分强度表示）总体趋势表现为先增加后下降.相对于弱碱性的环境（pH=8.0），弱酸性环境（pH=6.0）更有利于THA的光化学过程.氧气的存在很大程度上促进了DOM光化学转化过程，通入空气的条件下a₂₈₀的降解速率是氮气条件下的3.25倍.在不同光波段的实验下表明，可见光和紫外光对THA降解的贡献差异较大，紫外光波段的表观光子降解率（η）约为可见光的5~11倍.结果表明在气候变化背景下，亚高山湖泊中DOM的光化学降解将可能加快，亚高山湖泊在碳循环中的作用可能增强.;Dissolved organic matter (DOM) in lakes is ubiquitous and plays an important role in the aqueous ecosystem. DOM in sub-alpine lakes is dominated by the terrestrially-derived humic acid in the soil. Photodegradation is an important transformation process of DOM because of its strong light absorption, changing the form of carbon, nitrogen, phosphorus. Under the scenario of climate warming, DOM concentration, pH, dissolved oxygen and solar radiation in subalpine lakes may change. However, the effects of these environmental changes on DOM photodegradation in sub-alpine lakes are still unclear. In this paper, the photodegradation of allochthonous DOM in a sub-alpine lake-Lake Tiancai (located 200 m below the tree line) were studied. Firstly, the humic acid (THA) was extracted from the soil around Lake Tiancai. Then the photodegradation of THA was investigated at different light bands (ultraviolet or visible light) and different pH conditions. The results showed that four components were identified by excitation-emission matrix fluorescence coupled with parallel factor analysis (EEM-PARAFAC), including C1-C3 were humic-like fluorescence, accounting for 83.64% of the total fluorescence intensity, and C4 was protein-like substance, accounting for 16.36%. Under the irradiation of 500 W mercury lamp, the molecular weight of THA decreased gradually and DOC concentration decreased by 44.5% after 10 h. The value of a₂₈₀ (a proxy for colored dissolved organic matter (CDOM)) decreased gradually with the irradiation time; while the fluorescent dissolved organic matter (FDOM) showed an overall trend of increasing at first and then decreasing. Compared with the weakly alkaline media (pH=8.0), the weakly acidic media (pH=6.0) facilitated for the photochemical process of THA and acidification may further promote DOM degradation. Oxygen played a crucial role in DOM photochemical reaction as the pseudo-first-order kinetic constant of a₂₈₀ in the presence of oxygen was 3.25 times that in the absence of oxygen. The ultraviolet light was much more efficient for THA degradation than visible light. The apparent quantum degradation ratios (η) of ultraviolet light were about 5-11 times that of visible light. This result of this study suggested that under the scenario of climate change, the photodegradation of DOM in sub-alpine lakes might accelerate, enhancing the role of sub-alpine lakes in the carbon cycle.

Experimental Study on Dynamic Compression Mechanics of Sandstone after Coupled Alkali‐Chemical‐Dynamic Interaction

For the purpose of analyzing the effect of the alkaline solutions on the mechanical property of sandstone impact compression, the sandstone specimens of coal mine roadway were corroded in NaOH solution with pH 7 (neutral pure water solution) and pH = 8, 9, 10, 11, and 12 for 28 d, followed by dynamic compression tests using a separated Hopkinson compression bar test device, and the microstructural changes of the specimens were measured by SEM electron microscope scanning equipment. The studies indicate that the degree of damage to the dynamic properties of a sandstone specimen is tightly correlated with the variation of the pH value of the corrosion solution. The corrosion deterioration effect of the strong alkaline solution is most obvious, followed by the weak alkaline solution, and the mechanical properties of the sandstone are relatively stable under a neutral solution. The dynamic compressive strength and dynamic modulus of elasticity of specimens decrease as a quadratic and cubic function, respectively, with the rising pH of the solution. The dynamic peak strain and average strain rate tend to increase with the increase in pH, and they are larger than those of the uncorroded specimens. As the pH of the solution rises, the impact damage of the sandstone specimens intensifies, and the average particle size of the fragments tends to decrease in a quadratic polynomial.

Study on the optimal plug size design of weak alkaline ternary composite driven in block II7-12 of an oilfield A

The weakly alkaline ternary compound drive block in Block A II7-12 oil formation is the first block in an oilfield to adopt the lipopeptide compounded weakly alkaline ternary system for industrial production, and the explored target layer II7-12 belongs to Class IIB+ Class III oil formation. In view of the nature of the oil formation in the block, a study combining indoor physical model rating and numerical simulation was carried out, and the optimization of the size of the extended ternary main and secondary plugs was taken in the process according to the dynamic response at the right time to further improve the recovery rate and increase the economic benefits.

Preparation and demulsification performance of modified attapulgite nanoparticle demulsifier

By chemically modifying the attapulgite (AT) using 3-Aminopropyl triethoxysilane (APTES), stearic acid (STA) and/or octadecyl trichlorosilane (OTS), AT-APTES, AT-APTES-STA and AT-OTS nanoparticle demulsifiers were prepared. The structure and morphology of the prepared materials were characterized and analyzed by FT-IR, SEM and Zeta potential. Contact angle characterization and the distribution of nanoparticle materials in the oil-water mixture showed that the AT-APTES-STA nanomaterial has good amphiphilicity and interfacial activity. The demulsification performance of various NP demulsifiers was investigated by using bottle test method. The results showed that the AT-APTES-STA nanoparticles can achieve rapid and efficient demulsification of the crude oil emulsions at room temperature in a wide pH range from acidic to weak alkaline. The increase of demulsifier dosage and demulsification temperature was helpful to improve the demulsification efficieny. However, the influence of temperature on the demulsification efficiency was limited, and good demulsification efficiency could be obtained at room temperature. Under the conditions of demulsifier dosage 900 ppm, pH 7 and temperature 25℃, the demulsification efficiency of AT-APTES-STA was as high as 96.7%. In contrast, the AT-APTES had a poor demulsification efficiency, while the AT and AT-OTS materials basically do not have the demulsification ability. By comparing the demulsification performance and the chemical structure of these modified attapulgite nanoparticles, it was concluded that a NP demulsifier with excellent demulsification performance should have the following two basic characteristics: (a) good amphiphilicity and interfacial activity; and (b) enough surface functional groups that can strongly interact with the emulsified molecules. It is believed that this work is of great significance to the design and preparation of NP demulsifiers for the crude oil emulsion.

Bidirectional Light-Driven Ion Transport through Porphyrin Metal–Organic Framework-Based van der Waals Heterostructures via pH-Induced Band Alignment Inversion

Bidirectional Light-Driven Ion Transport through Porphyrin Metal–Organic Framework-Based van der Waals Heterostructures via pH-Induced Band Alignment Inversion

Biomimetic mineralization and characterization of hierarchically structured hydrated magnesium carbonates: The effects of sodium alginate

Recently, CO2 mineralization involving magnesium salt provides a feasible way for carbon sequestration. The produced hydrated magnesium carbonates (HMCs) can be used as functional materials and will bring huge economic benefits. Inspired by the mineralization in biological organisms, the indirect CO2 mineralization process involving NH4HCO3-MgCl2 in the presence of sodium alginate (SA) was systematically investigated. XRD, SEM, FTIR, TG and XPS were used to characterize the crystal phase, morphology, structure and surface of HMCs. By the regulation of temperature, HMCs with a complex hierarchical structure were successfully synthesized, i.e., sea urchin-like nesquehonite assembled by nanorods and 3D spiderweb-like hydromagnesite assembled by nanosheets. The presence of SA inhibits the phase transition from nesquehonite to hydromagnesite, and the inhibitory effect increases as the concentration of SA increases. By decreasing the molar ratio of Mg2+/HCO3−, the shape of nesquehonite particle changes from a sphere to an ellipsoid or a gourd. The spherical structure of nesquehonite is destroyed in a weak alkaline solution and the crystalline product is flower-like hydromagnesite in a strong alkaline solution. The decomposition process of HMCs is composed of dehydration (or dehydration and dehydroxylation) stage and decarbonation stage. XPS results for nesquehonite and hydromagnesite are quite different due to their different surface structure. This study will provide insights into the preparation of hierarchically structured HMCs by indirect CO2 mineralization and promote added values of HMCs by biomimetic mineralization method.

Efficient synthesis of 2,5-furandicarboxylic acid from biomass-derived 5-hydroxymethylfurfural in 1,4-dioxane/H2O mixture

The catalytic conversion of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA), a renewably sourced substitution for petroleum-derived terephthalic acid, at a high concentration is highly demanding but challenging. Herein, the efficient conversion of HMF (10–25 wt%) in 1,4-dioxane/H2O was achieved, and a desirable FDCA yield of 98% was obtained from HMF (10 wt%) over commercial Ru/C (2 Equiv. NaHCO3, 4 MPa O2, 3 h, and 140 ℃). In addition, a two-step cascade reaction was developed for FDCA production, in which FDCA was employed as the acid catalyst to promote the dehydration of fructose (10 wt%) to HMF, followed by oxidation in 1,4-dioxane/H2O to FDCA over Ru/C. As compared to pure water or 1,4-dioxane, the better stability of HMF in 1,4-dioxane/H2O with a weak alkaline environment and the enhancement of superoxide radicals (·O2-) in 1,4-dioxane/H2O could ensure high FDCA yield at high HMF concentration.

Fluorescence Characteristics of Coalbed Methane Produced Water and Its Influence on Freshwater Bacteria in the South Qinshui Basin, China

Production of coalbed methane (CBM) resources commonly requires using hydraulic fracturing and chemical production well additives. Concern exists for the existence of chemical compounds in CBM produced water, due to the risk of environmental receptor contamination. In this study, parallel factor method analysis (PARAFAC), fluorescence index, and the fluorescence area integral methods were used to analyse the properties of CBM produced water sampled from Shizhuang Block (one of the most active CBM-producing regions in the Qinshui Basin). A culture experiment was designed to determine the effect of discharged CBM produced water on microorganisms in freshwater. Water quality analysis shows the hydrochemistry of most water samples as Na-HCO3 type produced water of CBM appears as a generally weak alkaline (pH 8.69 ± 0.185) with high salinity, high alkalinity, and a high chemical oxygen demand (COD) value. Three individual components were identified by using parallel factor method analysis as humic-like components (C1), fulvic-like components (C2), and amino acid-like substances (C3). The fluorescence characteristic index comprehensively explains that the fluorescent substances in CBM produced water has the characteristics of a low degree of humification and a high recent self-generating source. The region integration results of characteristic peaks show that tyrosine-like and tryptophan-like materials account for more than 67% of fluorescent substances in CBM produced water. The addition of produced water from coalbed methane promotes the growth of freshwater bacteria, and this process is accompanied by the decrease of the proportion of fulvic acid, humic acid, and the increase of the proportion of soluble microbial metabolites. This paper proposes a convenient method for organic matter identification of CBM produced water and provides some theoretical support and reference for the improvement of CBM water treatment and utilization.

Tailoring time-varying alkaline microenvironment on titanium for sequential anti-infection and osseointegration

Initial implant-associated infection and later poor osseointegration are the main obstacles for bone implant success. Therefore, it is essential to endow implants with sequential antibacterial and osteogenic properties. However, bacteria and host cells share similar response mechanisms to external environments, so up to now, designing such implants remains a challenge. Here, we proposed a novel strategy of tailoring a time-varying surface alkaline microenvironment for sequential anti-infection and osteointegration, which was realized by constructing a two-layer hierarchical coating on the titanium with Ca-O-Ti as the inner layer and MgO as the outer layer. At the early stage of bone implantation, the outer MgO film rapidly generates a local strong alkaline microenvironment that disrupts bacterial energy metabolism and kills bacteria; at the later stage, the inner Ca-O-Ti layer maintains a long-term local weak alkaline microenvironment, which promotes stem cell adhesion, proliferation, and osteogenic differentiation to achieve successful osteointegration. The results of an in vivo experiment using a rat osteomyelitis model confirmed that the hierarchical coating inhibited infection and promoted the formation of new bone. This study demonstrates the potential of tailoring a time-varying alkaline microenvironment for sequential anti-infection and osteointegration, as a promising and safe strategy for the surface modification of bone implants.

Determination of As species distribution and variation with time in extracted groundwater samples by on-site species separation method

It is challenging to dependably keep the native distribution of arsenic (As) species before sample analysis in the laboratory. The on-site separation method can avoid sample contamination and species change in the process of sample collection and transportation from field to laboratory. In this study, As species distribution and variation of the extracted groundwater was first analyzed by an on-site species separation method in Jianghan Plain, China. Our study illustrated that: 1) high-As groundwater generally existed under mildly reducing conditions (Eh < 200 mV), weak alkaline conditions (pH < 7.2), elevated concentrations of dissolved Fe(II) and S(-II), and high proportions of As (III); 2) As species in the groundwater changed dramatically at room temperature in 36 hours post extraction (HPE). Fe-sulfide and Fe oxides minerals, which adsorbed As (V), were the main reasons influencing the As species concentration; 3) Acidification and strong complexing agents cannot preserve As species effectively. The average proportion of As (III) in the wells, where groundwater samples from the depth of 25 m exceed 10 μg L−1 As, can be reduced by 61% and 63% after HCl and EDTA were added, respectively. Accurate assessment of concentrations and distribution variation of As species in groundwater can guide the removal of As and the safe use of water resources, especially in drought areas relying on drinking well water.

Biliary reflux after laparoscopic modified antireflux monoanastomotic gastric bypass surgery

Aim. Determination of biliary reflux in patients with morbid obesity after a single-anastomotic gastric bypass operation performed in the clinic's modification and according to the classical Roux-en-Y gastric bypass technique. Development of diagnostic criteria for biliary reflux Materials and methods. The results of treatment of 36 patients with morbid obesity who underwent bypass surgery were studied. The patients are divided into two groups. Clinically modified laparoscopic monoanastomotic gastric bypass surgery was performed in 25 patients (main group). The control group included 11 patients after the standard technique of Roux-en-Y laparoscopic gastric bypass. Inclusion criteria were: persons of both sexes aged 18-60 years with morbid obesity and a body mass index of 40 or more, as well as 35 or more in the presence of comorbid diseases (type 2 diabetes mellitus, arterial hypertension, dyslipidemia, sleep apnea syndrome). In both groups, impedance pH measurements were performed in the postoperative period. Statistical processing was performed using the Statistica 13.0 software package using parametric and nonparametric statistical methods. Results: Clinical manifestations of the enterogastric biliary reflex were found in both groups; in addition, clinical manifestations of the corresponding symptoms were noted by patients of both groups. The analysis of daily pH-metry in the studied groups showed that in the esophagus the time with pH &lt;4 in the main group 2.83 (1.55; 3.95)% 3.00 (2.30; 3.50)% in the control group, time with pH 4-6.9 (physiological for the esophagus) 92.40 (90.65; 94.20)% and 94.10 (89.80; 95.50)%, respectively, time with pH&gt; 7 (weak alkaline) was 4.80 (3.45; 5.85)% and in the control group 2.90 (1.20; 7.20)%. There was no statistically significant difference in these indicators (p&gt; 0.05). Conclusions. Monoanastomotic gastric bypass surgery in the modification of the clinic has the same positive properties as the Rouen-Wye technique, allowing you to avoid the risks associated with possible pathological reflux of bile into the esophagus. Patients who have undergone mini-gastric bypass surgery require a thorough examination with fibrogastroscopy in combination with pH impedance measurement at least 1 time per year in order to determine biliary reflux and morphological changes both in the lumen of the esophagus and in the stomach stump. The level of quality of life of patients after surgery in the control group and the main group does not significantly differ, as evidenced by the results of the questionnaire survey using the GERG Q questionnaire, which indicates the effectiveness of the methodology of laparoscopic monoanastomotic gastric bypass surgery modified in the clinic. Key words: morbid obesity, gastric bypass surgery, surgical treatment, mini-gastric bypass, biliary reflux.

Efficient removal of hazardous benzohydroxamic acid (BHA) contaminants from the industrial beneficiation wastewaters by facile precipitation flotation process

Benzohydroxamic acid (BHA) is intensively used as collector in the mineral processing industry, and thus tremendous hazardous beneficiation wastewater containing BHA organic contaminant needs urgent treatment. In this work, an efficient removal of BHA organic contaminants from various industrial beneficiation wastewaters via the chelation, flocculation, and precipitation flotation process was studied. The removal efficiency of BHA, COD and turbidity of the purified water, and the chelation mechanism were investigated by optical microscope, SEM, FTIR, XPS, Zeta potential, and thermodynamic analyses. The results showed that organic BHA contaminant can be chelated firstly by Cu(II) to form hydrophobic BHA-Cu precipitate effectively via the “O-O” chelation and a five-membered chelation ring was formed under weak alkaline conditions. The generated precipitate was then successfully removed using CTAB as surfactant and NP-40 as frother in a microbubble flotation column. Over 94% BHA was removed under the optimal chelation, flocculation and flotation conditions: chelation with Cu(II) concentration of 30 mg/L and pH of 8 for 30 min; flocculation with CTAB concentration of 0.2 mg/L for 20 min; followed by flotation with NP-40 frother of 0.6 mg /L and air flow rate of 100 mL/min for over 40 min. Under this condition, 83.91% COD was removed, and the residuel COD and turbidity of the purified water were lower than 25 mg/L and 0.1 NTU, respectively, which met the wastewater discharge requirement. It’s demonstrated that the precipitate flotation can be employed as an effective method to purify industrial wastewater containing BHA. In addition, the interaction mechanism of Cu(II) and BHA under different pH values was also discussed in this work.

Selective leaching of vanadium from vanadium-molybdenum residue based on carbonation transformation at ambient temperature

A novel process is proposed to selectively leach vanadium and separate molybdenum from the vanadium-molybdenum residue (VMR) in the weakly alkaline solution, which is built on carbonation leaching. The optimal leaching conditions of the 16 wt% sodium carbonate, leaching temperature of 25℃, leaching time of 4 h, and liquid-solid ratio of 1.5:1 mL/g were systematically researched. And the leaching efficiency of vanadium and molybdenum were 86.85% and 7.73%. The equilibrium constant K was calculated from the solubility product Ksp of the calcium-based compounds, and it was found that calcium vanadate was considerably preferred to the transformation of calcium molybdate and sodium carbonate. Calcium vanadate was simpler to dissolve than calcium molybdate, simultaneously vanadium and molybdenum were separated. XRD and XPS analysis confirmed that vanadium was leached while molybdenum remained in the leaching residue. One of the reasons why a small amount of vanadium was not leached was that calcium sulfate participated in the carbonation transformation and consumed sodium carbonate. The other reason is that part of V(III) stably existed in the (Cr, Fe)2O3 spinel. The whole process of carbonation leaching is carried out at ambient temperature, which is a process of clean separation of vanadium and molybdenum.

Anti-Oxidative Effect of Weak Alkaline Reduced Water in RAW 264.7 Murine Macrophage Cells

Excessive oxidative stress (OS) is a common cause of various diseases such as cancer, diabetes, and obesity; thus, an anti-oxidative solution is essential for the improvement of human health. Increasing evidence suggests that alkaline reduced water (ARW), especially between pH 9.5–10.0, has antioxidant capacity; however, relatively few studies have reported the effect of weak ARW at pH 8.5 on OS, especially in vitro. This study was conducted to evaluate the anti-oxidative efficacy of weak ARW with negative oxidation-reduction potential (ORP) and relatively high hydrogen (H2) concentration, as compared to tap water (TW) and ARW at pH 9.5. RAW 264.7 murine macrophage cells, stimulated by hydrogen peroxide (H2O2) and lipopolysaccharide (LPS) to induce OS, were used as a control (Con) and then treated with TW and ARW at pH 8.5 (ARW_8.5) and pH 9.5 (ARW_9.5) at different concentrations (0.1%, 1%, and 10% v/v). Results showed that cell viability was significantly restored after treatment with both ARW_8.5 and ARW_9.5 compared to Con/H2O2 and Con/LPS, while TW treatment did not induce significant changes. Levels of reactive oxygen species (ROS), nitric oxide (NO), Ca2+, catalase, and glutathione peroxide (GPx) showed significant differences in a concentration-dependent manner in ARW_8.5 and ARW_9.5 groups compared to Con/H2O2 and Con/LPS groups. Likewise, the expression of p-p38, p-JNK, and p-ERK was also significantly reduced in the ARW-treated groups, but not in the TW group. In conclusion, ARW_8.5 exhibited anti-oxidative effects through the regulation of the MAPK signaling pathway in RAW 264.7 murine macrophage cells, indicating the health-promoting potential of weak ARW through daily intake.

Petrological Composition of the Last Coal Seam in the Longmendong Section before the End-Permian Mass Extinction

Late Permian coal deposits are widely distributed throughout southwestern China. This paper describes the petrological composition of the last coal seam in the Longmendong section of the Emeishan area during the latest Changhsingian (Permian) and records important information regarding the evolution of the mass extinction event that occurred at the end of the Permian. The results show that the dominant coal maceral group is vitrinite, followed by liptinite and inertinite macerals, and the coal minerals include quartz, chamosite and pyrite. The pyrofusinite and carbon microparticles occurrence modes could have been formed during wildfires in the adjacent areas. The β-tridymite occurrence modes and the high proportions and occurrence modes of magmatic quartz indicate that synchronous felsic volcanic activity occurred during the peat mire accumulation period. The chamosite and quartz occurrence modes suggest that they primarily precipitated from Fe-Mg-rich siliceous solutions that was derived from the weathering of nearby Emeishan basalt. The pyritic coal balls occurrence modes in the C1 coal seam are likely the result of coal-forming plants and Fe-Mg-rich siliceous solutions in neutral to weak alkaline conditions during late syngenetic stages or early epigenetic stages within paleomires.

Synthesis, aggregation behavior of alternating copolymer emulsifier in oil solution and its application in oil-based drilling fluids

In order to solve the emulsification problem of oil-based drilling fluids under high-temperature conditions, the copolymer emulsifier with the structure of alternating tertiary amine moieties and alkyl groups was synthesized by the reaction of N,N-dimethylethylenediamine and the alternating copolymer of maleic anhydride with 1-octadene (PMAO). The structure compositions and molecular weight of copolymer emulsifiers were characterized by FT-IR spectra, 1H NMR spectra, elemental analyse and multi-angle laser light scattering. The influence of tertiary amine moieties proportion in copolymer emulsifier on aggregation, interfacial activity, pH-response and emulsion stability were studied. The abundant presence of tertiary amine makes copolymer stabilize water-in-oil emulsion under neutral and weak alkaline conditions while destabilizing the emulsion under acidic conditions. Combining the above experimental data and the stability of water-in-oil emulsions prepared by the copolymer emulsifier, it was found that the emulsifier which has a high proportion of tertiary amine was indeed better at the performance of salt resistance under high temperature. When the copolymer emulsifier (D100) was used in an oil-based drilling fluid system, the electricity stability is greater than 1000 V and the filtrate volume is only 0.6 mL after aging at 232 °C for 16 h.