Background: Chemotherapy induced mucositis is one of the deterring factors influencing adherence to cancer treatment. Sodium bicarbonate mouth wash was recently shown to increase patients’ compliance. However, the co...Background: Chemotherapy induced mucositis is one of the deterring factors influencing adherence to cancer treatment. Sodium bicarbonate mouth wash was recently shown to increase patients’ compliance. However, the cost implication of this strategy was never explored. Aim: This study is designed to explore the compounding of sodium bicarbonate 2% mouth wash from sodium bicarbonate powder USP and commercially procured intravenous solution, and to determine the estimated cost implication for patients using this strategy. Materials and Methods: Sodium bicarbonate 2% were compounded using commercially procured sterile intravenous 8.4% solution and powder USP, diluted and dissolved in sterile water for irrigation respectively. The estimated cost savings between the 2 methods were compared to each other as well as to savings from when used in preventing or in adjuvant therapy for chemotherapy induced mucositis. Ethical approval not required by UVA Institutional Review Board. Study conducted according to the International Standards of Good Practice. Result: We came up with a new recipe, sodium bicarbonate 2% mouth wash using commercially procured sterile liquid formulation. Due to shortage, we compounded with sodium bicarbonate powder USP. Using USP 795 regulation, we assigned 14 days beyond use date with refrigeration to these formulations. These formulations resulted in estimated cost savings of $3597.52 and $3686.56 respectively if patients were to be treated for chemotherapy induced mucositis for 21 days. When compared to commercially procured sterile liquid formulation, the use of powder USP, will lead to additional estimated 60 to 66.67% savings for patients. Conclusion: By using sodium bicarbonate powder or solution to compound a 2% mouth wash, we came up with a cheap product that could be used by patients in the moment in the hospital. We were also able to suggest ways that an estimated cost savings for patients undergoing cancer treatment that use this product can be computed.展开更多
To solve the problem of ammonia wastewater pollution generated from preparing rare earth carbonate using the ammonium bicarbonate precipitation method,an eco-friendly precipitant,magnesium bicarbonate,was used to prep...To solve the problem of ammonia wastewater pollution generated from preparing rare earth carbonate using the ammonium bicarbonate precipitation method,an eco-friendly precipitant,magnesium bicarbonate,was used to prepare lanthanum cerium carbonate.The lanthanum cerium sulfate solution obtained from the smelting and separation of Baotou mixed rare earth ore was used as the raw material.The influence of pH on the content of impurities,including SO^(2-)_(4)and magnesium,and the existing states of SO^(2-)_(4)n lanthanum cerium carbonate products,as well as the thermal decomposition behavior of the products,were deeply explored.SO^(2-)_(4)mainly exists in the form of rare earth sulfate complex salts in lanthanum cerium carbonate products.The fo rmation of the salts can be effectively avoided by adjusting the pH of the precipitation process.Then the content of SO^(2-)_(4)in the product is controlled.When the pH ranges from 6.00 to 7.12,the content of SO^(2-)_(4)in the product ranges from 0.42 wt%to 0.99 wt%.The content of MgO is lower than 0.04 wt%.Both contents meet the requirements of the national standard GB/T 16479-2020.In this study,lanthanum cerium carbonate products with low-content SO^(2-)_(4)were prepared.In addition,the existing states of SO^(2-)_(4)in the products are revealed.The research provides a new method for controlling the impurity content in preparing lanthanum cerium carbonate.展开更多
The effect of Cl^(–)and SO_(4)^(2–)on corrosion behavior of pure copper in simulated groundwater was investigated by electrochemical testing techniques,scanning electron microscope/energy dispersive spectroscopy,X-r...The effect of Cl^(–)and SO_(4)^(2–)on corrosion behavior of pure copper in simulated groundwater was investigated by electrochemical testing techniques,scanning electron microscope/energy dispersive spectroscopy,X-ray photoelectron spectroscopy,and X-ray diffraction in 0.1 mol/L NaHCO_(3)solutions.The results indicate that increasing Cl^(-)and SO_(4)^(2–)reduces the corrosion resistance of Cu.Cl^(-)and SO_(4)^(2–)can promote anodic dissolution of Cu and deteriorate the passivation property.The breakdown potential(Eb)of Cu decreases with the increase in Cl^(-)and SO_(4)^(2–).With the increase in immersion time,the polarization resistance in different solutions tends to be stable.After 55 days,polarization resistance(Rp)was almost equal in 0 and 0.01 mol/L Cl^(-)and SO_(4)^(2–)solutions.In 0.05 mol/L Cl^(-)and SO_(4)^(2−)solution,Rp was lower.HCO3–has a certain corrosion effect on Cu and the pits size increased with the increase in Cl^(-)and SO_(4)^(2–).The corrosion products(Cu_(2)(OH)_(2)CO_(3))and CuO were detected in solutions without or at low Cl^(-)and SO_(4)^(2–)contents.The corrosion product after immersion in the solution containing 0.05 mol/L Cl^(-)and SO_(4)^(2–)was Cu_(2)O.展开更多
BACKGROUND Kidney dysfunction and reduced filtration capacity due to chronic kidney disease(CKD)lead to a shift in the body's acid-base balance,ultimately causing metabolic acidosis(MA).Sodium bicarbonate has been...BACKGROUND Kidney dysfunction and reduced filtration capacity due to chronic kidney disease(CKD)lead to a shift in the body's acid-base balance,ultimately causing metabolic acidosis(MA).Sodium bicarbonate has been used as a supplement to alleviate the symptoms and reverse the acidosis,and it may even slow the progression of CKD.However,its safety profile and overall effectiveness are uncertain.AIM To conduct a systematic review and meta-analysis of clinical trials assessing sodium bicarbonate's safety and efficacy for treating CKD-induced MA.METHODS Medline,Scopus,EMBASE,and Cochrane Central were systematically searched from inception until May 2024 to select all relevant randomized control trials(RCTs)and non-RCT(NRCTs)evaluating the effectiveness of sodium bicarbonate in correcting MA in end-stage renal disease patients.In addition,ClinicalTrials.gov,Medrxiv.org,and Google Scholar were searched for other literature.A random-effects meta-analysis was performed to derive mean differences(MD)and risk ratios(RR)with their 95%CI for continuous and dichotomous outcomes respectively.RESULTS Following a systematic search of the databases,20 RCTs and 2 and NRCTs comprising 2932 patients were included in our study.The results revealed that sodium bicarbonate significantly increased serum bicarbonate in CKD patients(MD:2.59,95%CI:0.95-4.22;P=0.02;I2=95%).However,there was a non-significant increase in estimated glomerular filtration rate(eGFR)in patients on sodium bicarbonate therapy(MD:0.93,95%CI:-1.88-3.75;P=0.52;I2=93%).Upon assessment of the safety profile of sodium bicarbonate,no significant association was found in the outcomes of death/prolonged hospitalization(RR:1.05,95%CI:0.84-1.32;P=0.66;I2=0%),or gastrointestinal disorders(RR:1.64,95%CI:0.35-7.66;P=0.53;I2=76%),or worsening edema(RR:1.26,95%CI:0.94-1.68;P=0.12;I2=37%)when compared to control.CONCLUSION Sodium bicarbonate therapy may halt worsening kidney function by correcting serum bicarbonate levels and treating MA.Although sodium bicarbonate does not significantly improve the eGFR,it may potentially prevent CKD progression while maintaining an overall favorable safety profile.展开更多
Photosynthesis is the most important biochemical reaction on Earth. It has co-evolved and developed with the Earth, driving the biogeochemical cycle of all elements on the planet and serving as the only chemical proce...Photosynthesis is the most important biochemical reaction on Earth. It has co-evolved and developed with the Earth, driving the biogeochemical cycle of all elements on the planet and serving as the only chemical process in nature that can convert light energy into chemical energy. Some heavy oxygen isotopic(^(18)O) labeling experiments have"conclusively" demonstrated that the oxygen released by photosynthesis comes only from water and are written into textbooks. However, it is not difficult to find that bicarbonate has never been excluded from the direct substrate of photosynthesis from beginning to end during the history of photosynthesis research. No convincing mechanism can be used to explain photosynthetic oxygen evolution solely from water photolysis. The bicarbonate effect, the Dole effect, the thermodynamic convenience of bicarbonate photolysis, the crystal structure characteristics of photosystem Ⅱ, and the reinterpretation of heavy oxygen isotopic labeling(^(18)O)experiments all indicate that the photosynthetic oxygen evolution does not exclude the important role and contribution of bicarbonate photolysis. The recently proposed view that bicarbonate photolysis is the premise of water photolysis, bicarbonate photolysis and water photolysis work together with a 1:1(mol/mol) stoichiometric relationship, and the stoichiometric relationship between oxygen and carbon dioxide released during photosynthetic oxygen evolution is also 1:1, has excellent applicability and objectivity, which can logically and reasonably explain the precise coordination between light and dark reactions during photosynthesis, the bicarbonate effect, the Dole effect, the Kok cycle and the neutrality of water and carbon in nature.This is of great significance for constructing the bionic artificial photosynthetic reactors and scientifically answering the question of the source of elemental stoichiometric relationships in nature.展开更多
The design of efficient heterogeneous catalysts in bicarbonate-activated hydrogen peroxide systems(BAP)is a hot topic in wastewater treatment.In this work,Cu_(2)O nanoparticles with different morphologies including cu...The design of efficient heterogeneous catalysts in bicarbonate-activated hydrogen peroxide systems(BAP)is a hot topic in wastewater treatment.In this work,Cu_(2)O nanoparticles with different morphologies including cubic shape(c-Cu_(2)O),octahedron shape(o-Cu_(2)O)and spherical shape(s-Cu_(2)O),were applied in BAP for the first time to degrade tetracycline hydrochloride(TC).Compared with Cu^(2+)ions and CuO,TC degradation was boosted in the presence of Cu_(2)O in the BAP system,with the degradation rate following the order c-Cu_(2)O>o-Cu_(2)O>s-Cu_(2)O.The morphology-dependent effects could be linearly correlated with the ratio of surface oxygen species(O_S),but not with the surface area or Cu(Ⅰ)ratio.The c-Cu_(2)O catalyst with exposure of(100)facets contained 76.6%O_Sas the active site for H_(2)O_(2)adsorption and activation,while the value was much lower for o-Cu_(2)O and s-Cu_(2)O with dominant(111)facets.The presence of HCO_(3)-enhanced the interactions among Cu_(2)O,H_(2)O_(2)and TC,leading to facile oxidation of Cu(Ⅰ)to Cu(Ⅱ)by H_(2)O_(2),and the formation of various reactive species such as hydroxyl radicals and Cu(Ⅲ)contributed to TC degradation.This work provides a new method for enhancing H_(2)O_(2)activation with heterogeneous catalysts by crystal facet engineering.展开更多
Combination of CO_(2) capture using inorganic alkali with subsequently electrochemical conversion of the resultant HCO_(3)^(-)to high-value chemicals is a promising route of low cost and high efficiency.The electroche...Combination of CO_(2) capture using inorganic alkali with subsequently electrochemical conversion of the resultant HCO_(3)^(-)to high-value chemicals is a promising route of low cost and high efficiency.The electrochemical reduction of HCO_(3)^(-)is challenging due to the inaccessible of negatively charged molecular groups to the electrode surface.Herein,we adopt a comprehensive strategy to tackle this challenge,i.e.,cascade of in situ chemical conversion of HCO_(3)^(-)to CO_(2) and CO_(2) electrochemical reduction in a flow cell.With a tailored Ni-N-S single atom catalyst(SACs),where sulfur(S)atoms located in the second shell of Ni center,the CO_(2)electroreduction(CO_(2)ER)to CO is boosted.The experimental results and density functional theory(DFT)calculations reveal that the introduction of S increases the p electron density of N atoms near Ni atom,thereby stabilizing^(*)H over N and boosting the first proton coupled electron transfer process of CO_(2)ER,i.e.,^(*)+e^(-)+^(*)H+^(*)CO_(2)→^(*)COOH.As a result,the obtained catalyst exhibits a high faradaic efficiency(FE_(CO)~98%)and a low overpotential of 425 mV for CO production as well as a superior turnover frequency(TOF)of 47397 h^(-1),outcompeting most of the reported Ni SACs.More importantly,an extremely high FECOof 90%is achieved at 50 mA cm^(-2)in the designed membrane electrode assembly(MEA)cascade electrolyzer fed with liquid bicarbonate.This work not only highlights the significant role of the second coordination on the first coordination shell of the central metal for CO_(2)ER,but also provides an alternative and feasible strategy to realize the electrochemical conversion of HCO_(3)^(-)to high-value chemicals.展开更多
BACKGROUND Tumoral calcinosis is a condition characterized by deposits of calcium phosphate crystals in extra-articular soft tissues,occurring in hemodialysis patients.Calcium phosphate crystals are mainly composed of...BACKGROUND Tumoral calcinosis is a condition characterized by deposits of calcium phosphate crystals in extra-articular soft tissues,occurring in hemodialysis patients.Calcium phosphate crystals are mainly composed of hydroxyapatite,which is highly infilt-rative to tissues,thus making complete resection difficult.An adjuvant method to remove or resolve the residual crystals during the operation is necessary.CASE SUMMARY A bicarbonate Ringer’s solution with bicarbonate ions(28 mEq/L)was used as the adjuvant.After resecting calcium phosphate deposits of tumoral calcinosis as much as possible,while filling with the solution,residual calcium phosphate deposits at the pseudocyst wall can be gently scraped by fingers or gauze in the operative field.A 49-year-old female undergoing hemodialysis for 15 years had swelling with calcium deposition for 2 years in the shoulders,bilateral hip joints,and the right foot.A shoulder lesion was resected,but the calcification remained and early re-deposition was observed.Considering the difficulty of a complete rection,we devised a bicarbonate dissolution method and excised the foot lesion.After resection of the calcified material,the residual calcified material was washed away with bicarbonate Ringer’s solution.CONCLUSION The bicarbonate dissolution method is a new,simple,and effective treatment for tumoral calcinosis in hemodialysis patients.展开更多
Carbon neutrality is widely concerned and highly valued by many countries.Biosphere has always maintained the balance between oxidized organic substances and assimilated organic matter,resulting in netzero carbon diox...Carbon neutrality is widely concerned and highly valued by many countries.Biosphere has always maintained the balance between oxidized organic substances and assimilated organic matter,resulting in netzero carbon dioxide(CO_(2)) emissions and maintaining its own carbon neutrality.Nature has set a good example for human beings to coordinate oxygen(O_(2)) balance and CO_(2)balance,and achieve carbon neutrality.How does photosynthetic oxygen evolution initiate carbon and water neutrality?My synthesis shows that photo system Ⅱ functions as carbonic anhydrase to catalyze the reaction of CO_(2)hydration under physiological conditions,and CO_(2)hydration coupled with chemical equilibrium,H^(+)+HCO_(3)^(-)→1/2O_(2)+2e^(-)+2H^(+)+CO_(2),occurs in a photosystem Ⅱ corecomplex.Meanwhile,I focused on the revisiting of four classical heavy oxygen(O^(18)) labeling experiments and found that bicarbonate can promote photo synthetic oxygen evolution,and that photo synthetic oxygen evolution can alternately come from bicarbonate and water,not only water.Bicarbonate photolysis and water photolysis account for half of the photo synthetic oxygen evolution respectively,which can well explain the bicarbonate effect,Dole effect and plants’ environmental adaptability.Photosynthetic oxygen evolution initiated the journey of water metabolism and carbon metabolism in nature,which led to the coupling as 1:1(mol/mol) stoichiometric relationship between the reduction of CO_(2)and oxidation of organic carbon,coordinated the evolution of the atmosphere,hydrosphere,lithosphere and biosphere,and realized "carbon neutrality" in the whole Earth system.展开更多
The serious limitations of available technologies for decontamination of wastewater have compelled researchers to search for alternative solutions. Catalytic treatment with hydrogen peroxide, which appears to be one o...The serious limitations of available technologies for decontamination of wastewater have compelled researchers to search for alternative solutions. Catalytic treatment with hydrogen peroxide, which appears to be one of the most efficient treatment systems, is able to degrade various organics with the help of powerful ·OH radicals. This review focuses on recent progress in the use of bicarbonate activated hydrogen peroxide for wastewater treatment. The introduction of bicarbonate to pollutant treatment has led to appreciable improvements, not only in process efficiency, but also in process stability. This review describes in detail the applications of this process in homogeneous and heterogeneous systems. The enhanced degradation, limited or lack of leaching during heterogeneous degradation, and prolonged catalysts stability during degradation are salient features of this system. This review provides readers with new knowledge regarding bicarbonate, including the fact that it does not always harm pollutant degradation, and can significantly benefit degradation under some conditions.展开更多
Rare earths(REs) are of vital importance for the development of new materials and green energy.Magnesium bicarbonate is one of the most recyclable and environmental-friendly precipitant for REs recovery from leaching ...Rare earths(REs) are of vital importance for the development of new materials and green energy.Magnesium bicarbonate is one of the most recyclable and environmental-friendly precipitant for REs recovery from leaching solutions. Nd_2(CO_3)_3 has difficulties in industrial production. So in this study,the precipitation of neodymium from chloride solution by magnesium bicarbonate are investigated. The effects of feeding method, [HCO_3^-]/[Nd^(3+)] mole ratio, feeding speed and reaction temperature on yield and impurity(magnesia) content are systematically studied. Results show that the impurity(magnesia)content decreases to 0.010 wt% with a yield approaching to 100% obtained under the conditions of[HCO_3^-]/[Nd^(3+)] = 3.00 by parallel flow addition at 50 ℃. The major impurity(magnesia) in rare earth carbonates mainly presents in the form of physical absorption, which can be easily removed by scrubbing. Therefore, it offers a promising green process that uses magnesium bicarbonate to produce neodymium carbonate due to its cycling of carbon dioxide, magnesium salt and waste water.展开更多
Primary canalicular bile undergoes a process of fluidization and alkalinization along the biliary tract that is influenced by several factors including hormones, innervation/neuropeptides, and biliary constituents. Th...Primary canalicular bile undergoes a process of fluidization and alkalinization along the biliary tract that is influenced by several factors including hormones, innervation/neuropeptides, and biliary constituents. The excretion of bicarbonate at both the canaliculi and the bile ducts is an important contributor to the generation of the so-called bile-salt independent flow. Bicarbonate is secreted from hepatocytes and cholangiocytes through parallel mechanisms which involve chloride efflux through activation of Cl- channels, and further bicarbonate secretion via AE2/SLC4A2-mediated Cl-/HCO3- exchange. Glucagon and secretin are two relevant hormones which seem to act very similarly in their target cells （hepatocytes for the former and cholangiocytes for the latter）. These hormones interact with their specific G protein-coupled receptors, causing increases in intracellular levels of cAMP and activation of cAMP-dependent Cl- and HCO3- secretory mechanisms. Both hepatocytes and cholangiocytes appear to have cAMP-responsive intracellular vesicles in which AE2/SLC4A2 colocalizes with cell specific Cl- channels （CFTR in cholangiocytes and not yet determined in hepatocytes） and aquaporins （AQP8 in hepatocytes and AQP1 in cholangiocytes）, cAMP-induced coordinated trafficking of these vesicles to either canalicular or cholangiocyte lumenal membranes and further exocytosis results in increased osmotic forces and passive movement of water with net bicarbonate-rich hydrocholeresis.展开更多
The passivation process of X80 pipeline steel in bicarbonate solutions was investigated using potentiodynamic, dynamic electro-chemical impedance spectroscopy （DEIS）, and Mott-Schottky measurements. The results show...The passivation process of X80 pipeline steel in bicarbonate solutions was investigated using potentiodynamic, dynamic electro-chemical impedance spectroscopy （DEIS）, and Mott-Schottky measurements. The results show that the shape of polarization curves changes with concentration. The critical ＇passive＇ concentration is 0.009 mol/L for X80 pipeline steel in bicarbonate solutions. No anodic current peak exists in solutions when the concentration is lower than 0.009 mol/L, whereas there are one and two anodic current peaks when the concentration ranges from 0.009 to 0.05 mol/L and is higher than 0.1 mol/L, respectively. DEIS measurements show that there exist active dissolution range, transition range, pre-passive range, passive layer formation range, passive range, and trans-passive range for X80 pipeline steel in the 0.1 mol/L solutions. The results of DEIS measurements are in complete agreement with the potentiodynamic diagram. An equivalent circuit containing three sub-layers is used to explain the Nyquist plots in the passive range. Analyses are well made for explaining the corresponding fitted capacitance and impedance. The Mott-Schottky plots show that the passive film of X80 pipeline steel is an n-type semiconductor, and capacitance measurements are in good accordance with the results of DEIS experiment.展开更多
Susceptibilities to stress corrosion cracking （SCC） of X80 pipeline steel in high pH solutions with various concentrations of HC03 at a passive potential of-0.2 V vs. SCE were investigated by slow strain rate tensi...Susceptibilities to stress corrosion cracking （SCC） of X80 pipeline steel in high pH solutions with various concentrations of HC03 at a passive potential of-0.2 V vs. SCE were investigated by slow strain rate tensile （SSRT） test. The SCC mechanism and the effect of HC03 were discussed with the aid of electrochemical techniques. It is indicated that X80 steel shows enhunced susceptibility to SCC with the concentration of HCO3 increasing from 0.15 to 1.00 mol/L, and the susceptibility can be evaluated in terms of current density at -0.2 V vs. SCE. The SCC behavior is controlled by the dissolution-based mechanism in these circumstances. Increasing the concentration of HCO3 not only increases the risk of rupture of passive films but also promotes the anodic dissolution of crack tips. Besides, little susceptibility to SCC is found in dilute solution containing 0.05 mol/L HCO3 for X80 steel. This can be attributed to the inhibited repassivation of passive films, manifesting as a more intensive dissolution in the non-crack tip areas than at the crack tips.展开更多
Fine spherical particle sized ceria (CeO_2) was prepared by homogeneous precipitation method with ammonium bicarbonate as precipitant. The prepared CeO_2 has the primary particle size of 10～50 nm when calcined betwee...Fine spherical particle sized ceria (CeO_2) was prepared by homogeneous precipitation method with ammonium bicarbonate as precipitant. The prepared CeO_2 has the primary particle size of 10～50 nm when calcined between 400～700 ℃ analyzed by XRD and the aggregated particle size is about 300 nm measured by LASER particle sizer. SEM, TG-DTA and Zeta-potential analyzer were employed individually to study the morphology and the formation of CeO_2 product. It was found that excess NH_4NO_3 can serve as an sphericallization agent to prepare spherical CeO_2 powder by precipitation method.展开更多
The effect of zinc(Zn) deficiency and excessive bicarbonate on the allocation and exudation of organic acids in plant organs(root, stem, and leaf) and root exudates of two Moraceae plants(Broussonetia papyrifera and M...The effect of zinc(Zn) deficiency and excessive bicarbonate on the allocation and exudation of organic acids in plant organs(root, stem, and leaf) and root exudates of two Moraceae plants(Broussonetia papyrifera and Morus alba) were investigated. Two Moraceae plants were hydroponically grown and cultured in nutrient solution in four different treatments with 0.02 mM Zn or no Zn,combined with no or 10 mM bicarbonate. The variations of organic acids in different plant organs were similar to those of root exudates in the four treatments except B. papyrifera, which was in a treatment that was a combination of 0.02 mM Zn and no bicarbonate. The response characteristics in the production, translocation, and allocation of organic acids in the plant organs and root exudates varied with species and treatments. Organic acids in plant organs and root exudates increased under Zn-deficient conditions,excessive bicarbonate, or both. An increase of organic acids in the leaves resulted in an increase of root-exuded organic acids. B. papyrifera translocated more oxalate and citrate from the roots to the rhizosphere than M. alba under the dual influence of 10 mM bicarbonate and Zn deficiency. Organic acids of leaves may be derived from dark respiration and photorespiration. By comparison, organic acids in stems, roots, and root exudates may be derived from dark respiration and organic acid translocation from the leaves. These results provide evidence for the selective adaptation of plants to environments with low Zn levels or high bicarbonate levels such as a karst ecosystem.展开更多
Diabetic ketoacidosis(DKA) is a severe and toocommon complication of uncontrolled diabetes mellitus. Acidosis is one of the fundamental disruptions stemming from the disease process, the complications of which are pot...Diabetic ketoacidosis(DKA) is a severe and toocommon complication of uncontrolled diabetes mellitus. Acidosis is one of the fundamental disruptions stemming from the disease process, the complications of which are potentially lethal. Hydration and insulin administration have been the cornerstones of DKA therapy; however, adjunctive treatments such as the use of sodium bicarbonate and protocols that include serial monitoring with blood gas analysis have been much more controversial. There is substantial literature available regarding the use of exogenous sodium bicarbonate in mild to moderately severe acidosis; the bulk of the data argue against significant benefit in important clinical outcomes and suggest possible adverse effects with the use of bicarbonate. However, there is scant data to support or refute the role of bicarbonate therapy in very severe acidosis. Arterial blood gas(ABG) assessment is an element of some treatment protocols, including society guidelines, for DKA. We review the evidence supporting these recommendations. In addition, we review the data supporting some less cumbersome tests, including venous blood gas assessment and routine chemistries. It remains unclear that measurement of blood gas pH, via arterial or venous sampling, impacts management of the patient substantially enough to warrant the testing, especially if sodium bicarbonate administration is not being considered. There are special circumstances when serial ABG monitoring and/or sodium bicarbonate infusion are necessary, which we also review. Additional studies are needed to determine the utility of these interventions in patients with severe DKA and pH less than 7.0.展开更多
Sensing of analyte s in biological fluids and biotechnological production media remains a challenge.He re,the luminescent response of the europium(Ⅲ)complex of 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid(DO3A...Sensing of analyte s in biological fluids and biotechnological production media remains a challenge.He re,the luminescent response of the europium(Ⅲ)complex of 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid(DO3A)to bicarbonate was investigated in detail.The response of Eu.DO3A to changes in bicarbonate concentration was studied in different buffers,and the influence of ionic strength,pH,and specific ions was determined.The response is found to depend on pH and ionic strength,but it is not possible to separate contributions from the sensing event from those in the bicarbonate activity.Prior to demonstrating the ability to determine the bicarbonate concentration in bioproduction media and serum,the influence of competing carboxy anions was evaluated.It is established that while competing anions bind stronger to the responsive complex,at the relevant concentration their contribution to the recorded signal is negligible.We are thus able to conclude that Eu.DO3A is a good platform for building a bicarbonate sensor.展开更多
Objective： To observe the influence of pH value on the proliferation of LAK cells and on the killing effect of rlL-2, IFN-α2b, TNF-α, LAK cells and doxorubicin on malignant tumor cells, and investigate the possibil...Objective： To observe the influence of pH value on the proliferation of LAK cells and on the killing effect of rlL-2, IFN-α2b, TNF-α, LAK cells and doxorubicin on malignant tumor cells, and investigate the possibility of increasing the efficacy of rlL-2 or IFN-α2b and doxorubicin by infusing sodium bicarbonate （NaHCO3） through target arteries. Methods： Separating single nucleus cells from peripheral blood of healthy men, and observing the influence of pH on the activation of single nucleus cells by rlL-2. MTT assay was used to measure the killing effect of rlL-2, IFN-α2b and TNF-α on 7404 cells and the increased effect of doxorubicin on rlL-2 and IFN-α2b, the cytotoxity of LAK cells in different pH. Forty-two patients with advanced primary liver cancer were obtained by stratified random, NaHCO3, rIL-2/IFN-α2b and doxorubicin were infused through target arteries. The efficacy was estimated after two cycles. Results： The conditions of pH 7.3 and pH 7.6 in vitro helped the proliferation of LAK cells and the killing effect of rIL-2, IFN-α2b and LAK cells on 7404 cells. In the condition of pH 6.8 there was almost no killing effect for LAK cells. In the condition of pH 7.0, 7.2, 7.4 and 7.6, the killing rate of TNF-α to 7404 cells increased by degrees, and in pH 7.4 the killing effect was the optimum. After two cycles treatments in the 42 patients with advanced primary liver cancer, the response rate （CR＋PR） was 88% （37/42）. The median overall response and median overall survival were increased, and no complication associated with infusing sodium bicarbonate was observed. Conclusion： The killing effect of rIL-2, IFN-α2b, TNF-α and doxorubicin on malignant tumor cells was enhanced by increasing the pH value.展开更多
The surface properties of PAN-based carbon fibers electrochemically treated in aqueous ammonium bicarbonate before and after treatment were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microsc...The surface properties of PAN-based carbon fibers electrochemically treated in aqueous ammonium bicarbonate before and after treatment were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and Dynamic Contact Angle Analysis (DCAA). The results of characterization indicated that the oxygen and nitrogen contents in carbon fiber surface were significantly increased by electrochemical treatment, and amide groups was introduced onto it, which was related with the electrolyte. The AFM photographs illustrated that the roughness of the fiber surface was also increased. The wettibality of the fibers was improved after treatment because the surface energy especially the polar part of it was increased.展开更多
文摘Background: Chemotherapy induced mucositis is one of the deterring factors influencing adherence to cancer treatment. Sodium bicarbonate mouth wash was recently shown to increase patients’ compliance. However, the cost implication of this strategy was never explored. Aim: This study is designed to explore the compounding of sodium bicarbonate 2% mouth wash from sodium bicarbonate powder USP and commercially procured intravenous solution, and to determine the estimated cost implication for patients using this strategy. Materials and Methods: Sodium bicarbonate 2% were compounded using commercially procured sterile intravenous 8.4% solution and powder USP, diluted and dissolved in sterile water for irrigation respectively. The estimated cost savings between the 2 methods were compared to each other as well as to savings from when used in preventing or in adjuvant therapy for chemotherapy induced mucositis. Ethical approval not required by UVA Institutional Review Board. Study conducted according to the International Standards of Good Practice. Result: We came up with a new recipe, sodium bicarbonate 2% mouth wash using commercially procured sterile liquid formulation. Due to shortage, we compounded with sodium bicarbonate powder USP. Using USP 795 regulation, we assigned 14 days beyond use date with refrigeration to these formulations. These formulations resulted in estimated cost savings of $3597.52 and $3686.56 respectively if patients were to be treated for chemotherapy induced mucositis for 21 days. When compared to commercially procured sterile liquid formulation, the use of powder USP, will lead to additional estimated 60 to 66.67% savings for patients. Conclusion: By using sodium bicarbonate powder or solution to compound a 2% mouth wash, we came up with a cheap product that could be used by patients in the moment in the hospital. We were also able to suggest ways that an estimated cost savings for patients undergoing cancer treatment that use this product can be computed.
基金Project supported by the National Natural Science Foundation of China(52274355)the National Key Research and Development Program of China(2022YFC2905305)+1 种基金the Gansu Province Science and Technology Major Special Project,China(22ZD6GD061)the Inner Mongolia Autonomous Region Science and Technology Revitalization of Inner Mongolia Cooperation Project,China(2022YFXM0001)。
文摘To solve the problem of ammonia wastewater pollution generated from preparing rare earth carbonate using the ammonium bicarbonate precipitation method,an eco-friendly precipitant,magnesium bicarbonate,was used to prepare lanthanum cerium carbonate.The lanthanum cerium sulfate solution obtained from the smelting and separation of Baotou mixed rare earth ore was used as the raw material.The influence of pH on the content of impurities,including SO^(2-)_(4)and magnesium,and the existing states of SO^(2-)_(4)n lanthanum cerium carbonate products,as well as the thermal decomposition behavior of the products,were deeply explored.SO^(2-)_(4)mainly exists in the form of rare earth sulfate complex salts in lanthanum cerium carbonate products.The fo rmation of the salts can be effectively avoided by adjusting the pH of the precipitation process.Then the content of SO^(2-)_(4)in the product is controlled.When the pH ranges from 6.00 to 7.12,the content of SO^(2-)_(4)in the product ranges from 0.42 wt%to 0.99 wt%.The content of MgO is lower than 0.04 wt%.Both contents meet the requirements of the national standard GB/T 16479-2020.In this study,lanthanum cerium carbonate products with low-content SO^(2-)_(4)were prepared.In addition,the existing states of SO^(2-)_(4)in the products are revealed.The research provides a new method for controlling the impurity content in preparing lanthanum cerium carbonate.
基金supported by the National Natural Science Foundation of China(No.U22B2065).
文摘The effect of Cl^(–)and SO_(4)^(2–)on corrosion behavior of pure copper in simulated groundwater was investigated by electrochemical testing techniques,scanning electron microscope/energy dispersive spectroscopy,X-ray photoelectron spectroscopy,and X-ray diffraction in 0.1 mol/L NaHCO_(3)solutions.The results indicate that increasing Cl^(-)and SO_(4)^(2–)reduces the corrosion resistance of Cu.Cl^(-)and SO_(4)^(2–)can promote anodic dissolution of Cu and deteriorate the passivation property.The breakdown potential(Eb)of Cu decreases with the increase in Cl^(-)and SO_(4)^(2–).With the increase in immersion time,the polarization resistance in different solutions tends to be stable.After 55 days,polarization resistance(Rp)was almost equal in 0 and 0.01 mol/L Cl^(-)and SO_(4)^(2–)solutions.In 0.05 mol/L Cl^(-)and SO_(4)^(2−)solution,Rp was lower.HCO3–has a certain corrosion effect on Cu and the pits size increased with the increase in Cl^(-)and SO_(4)^(2–).The corrosion products(Cu_(2)(OH)_(2)CO_(3))and CuO were detected in solutions without or at low Cl^(-)and SO_(4)^(2–)contents.The corrosion product after immersion in the solution containing 0.05 mol/L Cl^(-)and SO_(4)^(2–)was Cu_(2)O.
文摘BACKGROUND Kidney dysfunction and reduced filtration capacity due to chronic kidney disease(CKD)lead to a shift in the body's acid-base balance,ultimately causing metabolic acidosis(MA).Sodium bicarbonate has been used as a supplement to alleviate the symptoms and reverse the acidosis,and it may even slow the progression of CKD.However,its safety profile and overall effectiveness are uncertain.AIM To conduct a systematic review and meta-analysis of clinical trials assessing sodium bicarbonate's safety and efficacy for treating CKD-induced MA.METHODS Medline,Scopus,EMBASE,and Cochrane Central were systematically searched from inception until May 2024 to select all relevant randomized control trials(RCTs)and non-RCT(NRCTs)evaluating the effectiveness of sodium bicarbonate in correcting MA in end-stage renal disease patients.In addition,ClinicalTrials.gov,Medrxiv.org,and Google Scholar were searched for other literature.A random-effects meta-analysis was performed to derive mean differences(MD)and risk ratios(RR)with their 95%CI for continuous and dichotomous outcomes respectively.RESULTS Following a systematic search of the databases,20 RCTs and 2 and NRCTs comprising 2932 patients were included in our study.The results revealed that sodium bicarbonate significantly increased serum bicarbonate in CKD patients(MD:2.59,95%CI:0.95-4.22;P=0.02;I2=95%).However,there was a non-significant increase in estimated glomerular filtration rate(eGFR)in patients on sodium bicarbonate therapy(MD:0.93,95%CI:-1.88-3.75;P=0.52;I2=93%).Upon assessment of the safety profile of sodium bicarbonate,no significant association was found in the outcomes of death/prolonged hospitalization(RR:1.05,95%CI:0.84-1.32;P=0.66;I2=0%),or gastrointestinal disorders(RR:1.64,95%CI:0.35-7.66;P=0.53;I2=76%),or worsening edema(RR:1.26,95%CI:0.94-1.68;P=0.12;I2=37%)when compared to control.CONCLUSION Sodium bicarbonate therapy may halt worsening kidney function by correcting serum bicarbonate levels and treating MA.Although sodium bicarbonate does not significantly improve the eGFR,it may potentially prevent CKD progression while maintaining an overall favorable safety profile.
基金the Support Plan Projects of Science and Technology Department of Guizhou Province [No.(2021)YB453]。
文摘Photosynthesis is the most important biochemical reaction on Earth. It has co-evolved and developed with the Earth, driving the biogeochemical cycle of all elements on the planet and serving as the only chemical process in nature that can convert light energy into chemical energy. Some heavy oxygen isotopic(^(18)O) labeling experiments have"conclusively" demonstrated that the oxygen released by photosynthesis comes only from water and are written into textbooks. However, it is not difficult to find that bicarbonate has never been excluded from the direct substrate of photosynthesis from beginning to end during the history of photosynthesis research. No convincing mechanism can be used to explain photosynthetic oxygen evolution solely from water photolysis. The bicarbonate effect, the Dole effect, the thermodynamic convenience of bicarbonate photolysis, the crystal structure characteristics of photosystem Ⅱ, and the reinterpretation of heavy oxygen isotopic labeling(^(18)O)experiments all indicate that the photosynthetic oxygen evolution does not exclude the important role and contribution of bicarbonate photolysis. The recently proposed view that bicarbonate photolysis is the premise of water photolysis, bicarbonate photolysis and water photolysis work together with a 1:1(mol/mol) stoichiometric relationship, and the stoichiometric relationship between oxygen and carbon dioxide released during photosynthetic oxygen evolution is also 1:1, has excellent applicability and objectivity, which can logically and reasonably explain the precise coordination between light and dark reactions during photosynthesis, the bicarbonate effect, the Dole effect, the Kok cycle and the neutrality of water and carbon in nature.This is of great significance for constructing the bionic artificial photosynthetic reactors and scientifically answering the question of the source of elemental stoichiometric relationships in nature.
基金supported by the National Natural Science Foundation of China (No.51978542)the Opening Project of Hubei Key Laboratory of Biomass Fibers and Eco-Dyeing&Finishing (No.STRZ202113)。
文摘The design of efficient heterogeneous catalysts in bicarbonate-activated hydrogen peroxide systems(BAP)is a hot topic in wastewater treatment.In this work,Cu_(2)O nanoparticles with different morphologies including cubic shape(c-Cu_(2)O),octahedron shape(o-Cu_(2)O)and spherical shape(s-Cu_(2)O),were applied in BAP for the first time to degrade tetracycline hydrochloride(TC).Compared with Cu^(2+)ions and CuO,TC degradation was boosted in the presence of Cu_(2)O in the BAP system,with the degradation rate following the order c-Cu_(2)O>o-Cu_(2)O>s-Cu_(2)O.The morphology-dependent effects could be linearly correlated with the ratio of surface oxygen species(O_S),but not with the surface area or Cu(Ⅰ)ratio.The c-Cu_(2)O catalyst with exposure of(100)facets contained 76.6%O_Sas the active site for H_(2)O_(2)adsorption and activation,while the value was much lower for o-Cu_(2)O and s-Cu_(2)O with dominant(111)facets.The presence of HCO_(3)-enhanced the interactions among Cu_(2)O,H_(2)O_(2)and TC,leading to facile oxidation of Cu(Ⅰ)to Cu(Ⅱ)by H_(2)O_(2),and the formation of various reactive species such as hydroxyl radicals and Cu(Ⅲ)contributed to TC degradation.This work provides a new method for enhancing H_(2)O_(2)activation with heterogeneous catalysts by crystal facet engineering.
基金financially supported by the Natural Science Foundation of Shandong Province (ZR2020QB132,ZR2020MB025)the Opening Project of State Key Laboratory of High Performance Ceramics and Superfine Microstructure (SKL202108SIC)the Taishan Scholar Program of Shandong Province (ts201712046)。
文摘Combination of CO_(2) capture using inorganic alkali with subsequently electrochemical conversion of the resultant HCO_(3)^(-)to high-value chemicals is a promising route of low cost and high efficiency.The electrochemical reduction of HCO_(3)^(-)is challenging due to the inaccessible of negatively charged molecular groups to the electrode surface.Herein,we adopt a comprehensive strategy to tackle this challenge,i.e.,cascade of in situ chemical conversion of HCO_(3)^(-)to CO_(2) and CO_(2) electrochemical reduction in a flow cell.With a tailored Ni-N-S single atom catalyst(SACs),where sulfur(S)atoms located in the second shell of Ni center,the CO_(2)electroreduction(CO_(2)ER)to CO is boosted.The experimental results and density functional theory(DFT)calculations reveal that the introduction of S increases the p electron density of N atoms near Ni atom,thereby stabilizing^(*)H over N and boosting the first proton coupled electron transfer process of CO_(2)ER,i.e.,^(*)+e^(-)+^(*)H+^(*)CO_(2)→^(*)COOH.As a result,the obtained catalyst exhibits a high faradaic efficiency(FE_(CO)~98%)and a low overpotential of 425 mV for CO production as well as a superior turnover frequency(TOF)of 47397 h^(-1),outcompeting most of the reported Ni SACs.More importantly,an extremely high FECOof 90%is achieved at 50 mA cm^(-2)in the designed membrane electrode assembly(MEA)cascade electrolyzer fed with liquid bicarbonate.This work not only highlights the significant role of the second coordination on the first coordination shell of the central metal for CO_(2)ER,but also provides an alternative and feasible strategy to realize the electrochemical conversion of HCO_(3)^(-)to high-value chemicals.
文摘BACKGROUND Tumoral calcinosis is a condition characterized by deposits of calcium phosphate crystals in extra-articular soft tissues,occurring in hemodialysis patients.Calcium phosphate crystals are mainly composed of hydroxyapatite,which is highly infilt-rative to tissues,thus making complete resection difficult.An adjuvant method to remove or resolve the residual crystals during the operation is necessary.CASE SUMMARY A bicarbonate Ringer’s solution with bicarbonate ions(28 mEq/L)was used as the adjuvant.After resecting calcium phosphate deposits of tumoral calcinosis as much as possible,while filling with the solution,residual calcium phosphate deposits at the pseudocyst wall can be gently scraped by fingers or gauze in the operative field.A 49-year-old female undergoing hemodialysis for 15 years had swelling with calcium deposition for 2 years in the shoulders,bilateral hip joints,and the right foot.A shoulder lesion was resected,but the calcification remained and early re-deposition was observed.Considering the difficulty of a complete rection,we devised a bicarbonate dissolution method and excised the foot lesion.After resection of the calcified material,the residual calcified material was washed away with bicarbonate Ringer’s solution.CONCLUSION The bicarbonate dissolution method is a new,simple,and effective treatment for tumoral calcinosis in hemodialysis patients.
基金foundations of the National Natural Science Foundation of China [No. U1612441-2]Support Plan Projects of Science and Technology Department of Guizhou Province [No.(2021)YB453]。
文摘Carbon neutrality is widely concerned and highly valued by many countries.Biosphere has always maintained the balance between oxidized organic substances and assimilated organic matter,resulting in netzero carbon dioxide(CO_(2)) emissions and maintaining its own carbon neutrality.Nature has set a good example for human beings to coordinate oxygen(O_(2)) balance and CO_(2)balance,and achieve carbon neutrality.How does photosynthetic oxygen evolution initiate carbon and water neutrality?My synthesis shows that photo system Ⅱ functions as carbonic anhydrase to catalyze the reaction of CO_(2)hydration under physiological conditions,and CO_(2)hydration coupled with chemical equilibrium,H^(+)+HCO_(3)^(-)→1/2O_(2)+2e^(-)+2H^(+)+CO_(2),occurs in a photosystem Ⅱ corecomplex.Meanwhile,I focused on the revisiting of four classical heavy oxygen(O^(18)) labeling experiments and found that bicarbonate can promote photo synthetic oxygen evolution,and that photo synthetic oxygen evolution can alternately come from bicarbonate and water,not only water.Bicarbonate photolysis and water photolysis account for half of the photo synthetic oxygen evolution respectively,which can well explain the bicarbonate effect,Dole effect and plants’ environmental adaptability.Photosynthetic oxygen evolution initiated the journey of water metabolism and carbon metabolism in nature,which led to the coupling as 1:1(mol/mol) stoichiometric relationship between the reduction of CO_(2)and oxidation of organic carbon,coordinated the evolution of the atmosphere,hydrosphere,lithosphere and biosphere,and realized "carbon neutrality" in the whole Earth system.
基金supported by the National Natural Science Foundation of China(21273086)~~
文摘The serious limitations of available technologies for decontamination of wastewater have compelled researchers to search for alternative solutions. Catalytic treatment with hydrogen peroxide, which appears to be one of the most efficient treatment systems, is able to degrade various organics with the help of powerful ·OH radicals. This review focuses on recent progress in the use of bicarbonate activated hydrogen peroxide for wastewater treatment. The introduction of bicarbonate to pollutant treatment has led to appreciable improvements, not only in process efficiency, but also in process stability. This review describes in detail the applications of this process in homogeneous and heterogeneous systems. The enhanced degradation, limited or lack of leaching during heterogeneous degradation, and prolonged catalysts stability during degradation are salient features of this system. This review provides readers with new knowledge regarding bicarbonate, including the fact that it does not always harm pollutant degradation, and can significantly benefit degradation under some conditions.
基金supported by National Science and Technology Support Program of China(2015BAB16B03)the National Natural Science Foundation of China(51504034,51674037)
文摘Rare earths(REs) are of vital importance for the development of new materials and green energy.Magnesium bicarbonate is one of the most recyclable and environmental-friendly precipitant for REs recovery from leaching solutions. Nd_2(CO_3)_3 has difficulties in industrial production. So in this study,the precipitation of neodymium from chloride solution by magnesium bicarbonate are investigated. The effects of feeding method, [HCO_3^-]/[Nd^(3+)] mole ratio, feeding speed and reaction temperature on yield and impurity(magnesia) content are systematically studied. Results show that the impurity(magnesia)content decreases to 0.010 wt% with a yield approaching to 100% obtained under the conditions of[HCO_3^-]/[Nd^(3+)] = 3.00 by parallel flow addition at 50 ℃. The major impurity(magnesia) in rare earth carbonates mainly presents in the form of physical absorption, which can be easily removed by scrubbing. Therefore, it offers a promising green process that uses magnesium bicarbonate to produce neodymium carbonate due to its cycling of carbon dioxide, magnesium salt and waste water.
基金the "UTE for CIMA project" as well as by a grant from the "Institute de Salud CarlosⅢ" (PI051098). J. M. B. has a grant from the Spanish Ministry of Science and Technology
文摘Primary canalicular bile undergoes a process of fluidization and alkalinization along the biliary tract that is influenced by several factors including hormones, innervation/neuropeptides, and biliary constituents. The excretion of bicarbonate at both the canaliculi and the bile ducts is an important contributor to the generation of the so-called bile-salt independent flow. Bicarbonate is secreted from hepatocytes and cholangiocytes through parallel mechanisms which involve chloride efflux through activation of Cl- channels, and further bicarbonate secretion via AE2/SLC4A2-mediated Cl-/HCO3- exchange. Glucagon and secretin are two relevant hormones which seem to act very similarly in their target cells （hepatocytes for the former and cholangiocytes for the latter）. These hormones interact with their specific G protein-coupled receptors, causing increases in intracellular levels of cAMP and activation of cAMP-dependent Cl- and HCO3- secretory mechanisms. Both hepatocytes and cholangiocytes appear to have cAMP-responsive intracellular vesicles in which AE2/SLC4A2 colocalizes with cell specific Cl- channels （CFTR in cholangiocytes and not yet determined in hepatocytes） and aquaporins （AQP8 in hepatocytes and AQP1 in cholangiocytes）, cAMP-induced coordinated trafficking of these vesicles to either canalicular or cholangiocyte lumenal membranes and further exocytosis results in increased osmotic forces and passive movement of water with net bicarbonate-rich hydrocholeresis.
基金supported by the National Science and Technology Infrastructure Platforms Construction Projects (No.2005DKA10400)
文摘The passivation process of X80 pipeline steel in bicarbonate solutions was investigated using potentiodynamic, dynamic electro-chemical impedance spectroscopy （DEIS）, and Mott-Schottky measurements. The results show that the shape of polarization curves changes with concentration. The critical ＇passive＇ concentration is 0.009 mol/L for X80 pipeline steel in bicarbonate solutions. No anodic current peak exists in solutions when the concentration is lower than 0.009 mol/L, whereas there are one and two anodic current peaks when the concentration ranges from 0.009 to 0.05 mol/L and is higher than 0.1 mol/L, respectively. DEIS measurements show that there exist active dissolution range, transition range, pre-passive range, passive layer formation range, passive range, and trans-passive range for X80 pipeline steel in the 0.1 mol/L solutions. The results of DEIS measurements are in complete agreement with the potentiodynamic diagram. An equivalent circuit containing three sub-layers is used to explain the Nyquist plots in the passive range. Analyses are well made for explaining the corresponding fitted capacitance and impedance. The Mott-Schottky plots show that the passive film of X80 pipeline steel is an n-type semiconductor, and capacitance measurements are in good accordance with the results of DEIS experiment.
文摘Susceptibilities to stress corrosion cracking （SCC） of X80 pipeline steel in high pH solutions with various concentrations of HC03 at a passive potential of-0.2 V vs. SCE were investigated by slow strain rate tensile （SSRT） test. The SCC mechanism and the effect of HC03 were discussed with the aid of electrochemical techniques. It is indicated that X80 steel shows enhunced susceptibility to SCC with the concentration of HCO3 increasing from 0.15 to 1.00 mol/L, and the susceptibility can be evaluated in terms of current density at -0.2 V vs. SCE. The SCC behavior is controlled by the dissolution-based mechanism in these circumstances. Increasing the concentration of HCO3 not only increases the risk of rupture of passive films but also promotes the anodic dissolution of crack tips. Besides, little susceptibility to SCC is found in dilute solution containing 0.05 mol/L HCO3 for X80 steel. This can be attributed to the inhibited repassivation of passive films, manifesting as a more intensive dissolution in the non-crack tip areas than at the crack tips.
基金Project supported by Rare Earth Department of National Development Committee Preparation of High Quality Polishing Powder
文摘Fine spherical particle sized ceria (CeO_2) was prepared by homogeneous precipitation method with ammonium bicarbonate as precipitant. The prepared CeO_2 has the primary particle size of 10～50 nm when calcined between 400～700 ℃ analyzed by XRD and the aggregated particle size is about 300 nm measured by LASER particle sizer. SEM, TG-DTA and Zeta-potential analyzer were employed individually to study the morphology and the formation of CeO_2 product. It was found that excess NH_4NO_3 can serve as an sphericallization agent to prepare spherical CeO_2 powder by precipitation method.
基金funded by the National Key Basic Research Program of China under Grant No. 2013CB956701the National Natural Science Foundation of China under Grant No. 31070365Funded by talents introduction of Anqing Normal University (No. 14000100032)
文摘The effect of zinc(Zn) deficiency and excessive bicarbonate on the allocation and exudation of organic acids in plant organs(root, stem, and leaf) and root exudates of two Moraceae plants(Broussonetia papyrifera and Morus alba) were investigated. Two Moraceae plants were hydroponically grown and cultured in nutrient solution in four different treatments with 0.02 mM Zn or no Zn,combined with no or 10 mM bicarbonate. The variations of organic acids in different plant organs were similar to those of root exudates in the four treatments except B. papyrifera, which was in a treatment that was a combination of 0.02 mM Zn and no bicarbonate. The response characteristics in the production, translocation, and allocation of organic acids in the plant organs and root exudates varied with species and treatments. Organic acids in plant organs and root exudates increased under Zn-deficient conditions,excessive bicarbonate, or both. An increase of organic acids in the leaves resulted in an increase of root-exuded organic acids. B. papyrifera translocated more oxalate and citrate from the roots to the rhizosphere than M. alba under the dual influence of 10 mM bicarbonate and Zn deficiency. Organic acids of leaves may be derived from dark respiration and photorespiration. By comparison, organic acids in stems, roots, and root exudates may be derived from dark respiration and organic acid translocation from the leaves. These results provide evidence for the selective adaptation of plants to environments with low Zn levels or high bicarbonate levels such as a karst ecosystem.
文摘Diabetic ketoacidosis(DKA) is a severe and toocommon complication of uncontrolled diabetes mellitus. Acidosis is one of the fundamental disruptions stemming from the disease process, the complications of which are potentially lethal. Hydration and insulin administration have been the cornerstones of DKA therapy; however, adjunctive treatments such as the use of sodium bicarbonate and protocols that include serial monitoring with blood gas analysis have been much more controversial. There is substantial literature available regarding the use of exogenous sodium bicarbonate in mild to moderately severe acidosis; the bulk of the data argue against significant benefit in important clinical outcomes and suggest possible adverse effects with the use of bicarbonate. However, there is scant data to support or refute the role of bicarbonate therapy in very severe acidosis. Arterial blood gas(ABG) assessment is an element of some treatment protocols, including society guidelines, for DKA. We review the evidence supporting these recommendations. In addition, we review the data supporting some less cumbersome tests, including venous blood gas assessment and routine chemistries. It remains unclear that measurement of blood gas pH, via arterial or venous sampling, impacts management of the patient substantially enough to warrant the testing, especially if sodium bicarbonate administration is not being considered. There are special circumstances when serial ABG monitoring and/or sodium bicarbonate infusion are necessary, which we also review. Additional studies are needed to determine the utility of these interventions in patients with severe DKA and pH less than 7.0.
基金Project supported by the University of Copenhagen,the Novo Nordisk Foundation(grant number 4096)Carlsbergfondet,the Villum Foundation(grant number 14922)ENS Lyon。
文摘Sensing of analyte s in biological fluids and biotechnological production media remains a challenge.He re,the luminescent response of the europium(Ⅲ)complex of 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid(DO3A)to bicarbonate was investigated in detail.The response of Eu.DO3A to changes in bicarbonate concentration was studied in different buffers,and the influence of ionic strength,pH,and specific ions was determined.The response is found to depend on pH and ionic strength,but it is not possible to separate contributions from the sensing event from those in the bicarbonate activity.Prior to demonstrating the ability to determine the bicarbonate concentration in bioproduction media and serum,the influence of competing carboxy anions was evaluated.It is established that while competing anions bind stronger to the responsive complex,at the relevant concentration their contribution to the recorded signal is negligible.We are thus able to conclude that Eu.DO3A is a good platform for building a bicarbonate sensor.
基金a grant from the Key Scientific Research Projects of Anhui Province (No. 0123027).
文摘Objective： To observe the influence of pH value on the proliferation of LAK cells and on the killing effect of rlL-2, IFN-α2b, TNF-α, LAK cells and doxorubicin on malignant tumor cells, and investigate the possibility of increasing the efficacy of rlL-2 or IFN-α2b and doxorubicin by infusing sodium bicarbonate （NaHCO3） through target arteries. Methods： Separating single nucleus cells from peripheral blood of healthy men, and observing the influence of pH on the activation of single nucleus cells by rlL-2. MTT assay was used to measure the killing effect of rlL-2, IFN-α2b and TNF-α on 7404 cells and the increased effect of doxorubicin on rlL-2 and IFN-α2b, the cytotoxity of LAK cells in different pH. Forty-two patients with advanced primary liver cancer were obtained by stratified random, NaHCO3, rIL-2/IFN-α2b and doxorubicin were infused through target arteries. The efficacy was estimated after two cycles. Results： The conditions of pH 7.3 and pH 7.6 in vitro helped the proliferation of LAK cells and the killing effect of rIL-2, IFN-α2b and LAK cells on 7404 cells. In the condition of pH 6.8 there was almost no killing effect for LAK cells. In the condition of pH 7.0, 7.2, 7.4 and 7.6, the killing rate of TNF-α to 7404 cells increased by degrees, and in pH 7.4 the killing effect was the optimum. After two cycles treatments in the 42 patients with advanced primary liver cancer, the response rate （CR＋PR） was 88% （37/42）. The median overall response and median overall survival were increased, and no complication associated with infusing sodium bicarbonate was observed. Conclusion： The killing effect of rIL-2, IFN-α2b, TNF-α and doxorubicin on malignant tumor cells was enhanced by increasing the pH value.
基金Sponsored by the Scientific Research Foundation of Harbin Institute of Technology(Grant No. HIT. 2003.57)
文摘The surface properties of PAN-based carbon fibers electrochemically treated in aqueous ammonium bicarbonate before and after treatment were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and Dynamic Contact Angle Analysis (DCAA). The results of characterization indicated that the oxygen and nitrogen contents in carbon fiber surface were significantly increased by electrochemical treatment, and amide groups was introduced onto it, which was related with the electrolyte. The AFM photographs illustrated that the roughness of the fiber surface was also increased. The wettibality of the fibers was improved after treatment because the surface energy especially the polar part of it was increased.
