NaHCO3 Concentration Research Articles

The role of alkali in sweet potato starch-Mesona chinensis Benth polysaccharide gels: Gelation, rheological and structural properties

According to the Chinese traditional black jelly production process, a critical step to ensure the quality of jelly is to add alkali to it. In this study, the effects of sodium carbonate (Na2CO3) and sodium bicarbonate (NaHCO3) on the pasting, rheological, textural, and structural properties of sweet potato starch (SPS)-Mesona chinensis Benth polysaccharide (MCP) gels were evaluated. Adding Na2CO3 at low concentration reduced the final viscosity (FV) of SPS-MCP gels, whereas adding it at a high concentration increased the FV. Adding NaHCO3 can increase the FV of SPS-MCP gels in a concentration-dependent manner. Rheological results indicated that adding NaHCO3 at a low concentration decreased the storage modulus of SPS-MCP gels, whereas adding it at a high concentration increased the storage modulus. The storage modulus of SPS-MCP gels increased with increasing concentration of NaHCO3. The addition of Na2CO3 and NaHCO3 improved the textural properties of SPS-MCP gels and decreased the water mobility. Infrared results indicated that adding alkali can enhance the hydrogen bonding between SPS and MCP. Scanning electron microscopy results suggested that alkali can reduce the size of gels, and make the structure more compact.

Capability of carbon fixation in bicarbonate-based and carbon dioxide-based systems by Scenedesmus acuminatus TH04

Carbon sequestration using microalgae can be performed from bicarbonate (a product of carbon dioxide capture) and/or carbon dioxide. To implement either process successfully, the capability of microalgal strains is the most important criteria. In this work, a thermophilic microalgal Scenedesmus acuminatus TH04 was investigated to optimize its growth and carbon fixation in bicarbonate-based and carbon dioxide-based reactor systems. Culture variables including temperature, light intensity, pH, and aeration rate, concentration of NaHCO3, Na2CO3, CO2 and triethylenetetramine (TETA) were examined. The S. acuminatus TH04 strain achieved the highest biomass production and bicarbonate fixation efficiency of 1.7 g/L and 100 %, respectively, with 4.2 g NaHCO3/L. In a single photobioreactor (PBR), the maximum biomass production and CO2 fixation efficiency of 4.7 g/L and 9.8 % were achieved under the optimal conditions of CO2 of 5% (v/v), aeration rate of 0.1 vvm, TETA of 5 mM and Na2CO3 of 50 mM. Remarkably, a sequence of ten PBRs increased CO2 fixation efficiency by S. acuminatus TH04 to 93.9 %. The S. acuminatus TH04 strain demonstrated a highly potential capability in simultaneous production of biomass and carbon fixation from HCO3− and CO2 as carbon sources.

Exogenous NaHCO3 enhances growth and lipid accumulation of the highly NaHCO3-tolerant Nannochloris sp. JB17

The extremely saline-alkaline soil in the northeast of China is rich in Na2CO3 and NaHCO3. Previously, we isolated the green alga Nannochloris sp. JB17 (JB17) from this soil and found that it was resistant to high concentrations of NaHCO3. In this study, the biochemical characteristics of JB17 cultured with NaHCO3 were studied by measuring growth and photosynthesis, and biomass, starch, and lipid production. The final cell density and maximum dry weight of JB17 cultured with 300 mM NaHCO3 were 1.528 and 1040.8 mg L−1, respectively, and were higher than those of JB17 cultured with 50 mM NaHCO3 (control). The maximum chlorophyll-a content and oxygen evolution rate under 300 mM NaHCO3 treatment were 26.5 mg g−1and 182 μmol O2 mg−1 Chl h−1, respectively, and were higher than those of the control. The addition of 300 mM NaHCO3 increased the relative electron transfer rate (rETR) and maximum relative electron transfer rate of JB17. The total starch and lipids contents of JB17 significantly increased from 215 to 356 mg g−1 and from 263 to 531 mg g−1, respectively, after the addition of 300 mM NaHCO3. Including NaHCO3 in the culture medium greatly stimulated the growth, biomass accumulation, and lipid productivity of JB17. These results indicate that the accumulation of starch and lipids in JB17 cultured with NaHCO3 might be related to the promotion of photosynthesis.

Improving the mechanical performance of biocomposite plaster/ Washingtonian filifira fibres using the RSM method

This article describes a study on the use of a new biocomposite for the construction material made of plaster and fibres extracted from palm Washingtonia filifera (WF), also known under the name palm desert or California. The main objective is to investigate the influence of the treatment of WF fibres with NaHCO3 on the mechanical properties of the resulting biocomposite. Several plaster/WF fibre composites are prepared with 2% of untreated WF fibres and treated for different treatment times (24, 72, 168 and 240 h) according to different NaHCO3 concentrations (5, 10 and 20%). The mechanical properties in tensile and 3-point bending are studied respectively for untreated (WF) fibres and elaborated gypsum/fibre (WF) composites. The results obtained show that the incorporation of WF fibres into the plaster matrix improves the mechanical performance of this new biocomposite and its ductility. Response Surface Methodology (RSM) is used to statistically study the experimental results. Response models generated by ANOVA, indicate that the rate of NaHCO3 significantly influences the ultimate strength and flexural modulus. The optimization study showed that the ideal rate of NaHCO3 is 20%, while the optimum treatment time is 168 h, which is in agreement with the experimental results.

Sustainable carbon capture via halophilic and alkaliphilic cyanobacteria: the role of light and bicarbonate

The two-step photosynthetic biogas upgrading process, which combines CO2 capture by carbonate solution and carbonate regeneration by using aquatic microbial oxygenic photoautotrophs (i.e., cyanobacteria, algae, and diatoms), may provide a potential alternative to the commercial routes used for gaseous biofuel upgrading. Such a process not only provides a green and low energy intensive biogas upgrading pathway but also converts CO2 in biogas into high value biomass. To improve the upgrading performance, the effects of light intensity and NaHCO3 concentration on the growth and the HCO3- transformation characteristics of halophilic and alkaliphilic Spirulina platensis were investigated in this study. Experimental results showed that the light attenuation of S. platensis culture was significant. Increasing light intensity up to 210 μmol m-2 s-1 effectively improved the S. platensis growth and photosynthetic pigment accumulation. S. platensis could grow in the range of 0.05 to 0.6 M NaHCO3, and a maximum biomass concentration of 1.46 g L-1 was achieved under an optimal growth condition of 0.1 M NaHCO3, which was 65.9% higher than at 0.05 M NaHCO3. Moreover, the bicarbonate utilization efficiency reached 42.0%. Finally, in a case study, a biogas stream at a flow rate of 800 m3 h-1 could generate biomass up to 344 kg h-1, corresponding an energy value of 5591 MJ h-1.

Experimental Research on the Optimization and Evaluation of the Polymer/Chromium-Ion Deep Profile Control System for the Fractured Low-Permeability Reservoirs

The matrix/fracture conductivity of a fractured low-permeability reservoir is variable, and its heterogeneity is serious. When carrying out deep profile control measures, it is difficult to inject under the premise of ensuring the plugging effect. According to the characteristics of the fractured low-permeability reservoir in Chaoyanggou Oilfield, the polymer/chromium ion deep profile control system was optimized via a viscosity evaluation experiment, liquidity experiment and oil displacement experiment. The experimental results show that the high molecular weight main agent/low concentration system and low molecular weight main agent/high concentration system can meet the gel strength requirement. The evaluation results of the injection ability and plugging performance of the fractured low-permeability core show that a high molecular weight profile control system is difficult to inject, while a low molecular weight profile control system has a poor plugging performance and high cost after simulated shear. Therefore, the formulation of the profile control system was determined to be a polymer with a molecular weight of 16 million g·mol−1 as the main agent with a concentration of 1000–1500 mg·L−1. As assisting agents, the concentrations of thiourea, NaCl and NaHCO3 were 900 mg·L−1, 800 mg·L−1 and 700 mg·L−1, respectively. The plugging rate of the system was 87.6%, and the resistance coefficient was 19.2. Finally, a fractured low-permeability core model with parallel long cores was designed, and the optimal profile control system was used for the core oil-displacement experiment. Compared with the water-flooding experiment, the plugging rate can be increased by 6.9–8.0%.

Solvent Extraction of Vanadium from Sodium Carbonate–Sodium Bicarbonate Solution Using Aliquat-336

The solvent extraction of vanadium (V) from Na2CO3–NaHCO3 solution was attempted using Aliquat-336 (methyltrioctylammonium chloride) extractant dissolved in sulfonated kerosene as diluent with 2-octanol as phase modifier. The influence factors, such as Na2CO3 concentration, NaHCO3 concentration, temperature, extractant concentration and impurity P, on vanadium extraction were investigated. The results revealed that the single stage extraction efficiency of vanadium reached above 89% from 20 g/L Na2CO3 – 20 g/L NaHCO3 solution under the following conditions: extractant concentration of 15%, room temperature of 20–30 °C, 2-octanol of 6%, phase ratio (O/A) of 1:1, and oscillation time of 1 min. The addition of NaHCO3 into Na2CO3 solution could lower the pH value of the Na2CO3 solution, improve extraction efficiency of vanadium, and not introduce other impurities. The phosphate anion did not interact with the vanadate anion in the Na2CO3–NaHCO3 solution. The P in the Na2CO3–NaHCO3 solution had little influence on vanadium extraction.

Development and in vitro evaluation of domperidone/Dowex resinate embedded gastro-floatable emulgel and effervescent alginate beads

This work aims to develop and evaluate buoyant beads embedded with domperidone/Dowex 50WX2 resinate complex as novel multiple-unit type oral gastro-retentive drug delivery system. Domperidone (BCS II) has been chosen for gastric retention as it has a poor oral bioavailability (around 15%), a short biological half-life, and pH-dependent solubility with poor solubility at a high pH and good solubility at low pH. Two different techniques were used to induce beads buoyancy; first, formulation of effervescent beads by incorporation of NaHCO3 in the beads, which will release carbon dioxide gas upon reaction with the acidic gastric fluid causing the beads to float. Second, is the formation of low-density emulgel beads by the incorporation of light mineral oil in the beads. Resinate complex is used to control the drug release from the prepared formulations. Beads were evaluated for percent drug entrapment efficiency, floating behavior (float lag time and duration), mean particle diameter, in vitro drug release, and release kinetics in SGF. The effect of different concentrations of both NaHCO3 (1%, 2%, and 10%) and light mineral oil (2%, 5%, and 10%) on the floating behavior and physical appearance was studied. The optimized formula (F10) was subjected to a four-week stability study at both 25 °C and 40 °C. Results revealed that gastro-retentive beads possessed a floating duration of up to 24 h and no floating lag time was developed. The novel resinate loaded beads succeeded to sustain the release of domperidone in SGF. The optimized formula was stable at both temperatures of 25 °C and 40 °C for four weeks. Hence, the developed optimized formulation (F10) is considered as a potential to increase the domperidone bioavailability, decrease dosage frequency, and increase patient compliance.

Geochemical Characteristics and Influencing Factors of Groundwater Fe in Seawater Intrusion Area

To reveal the influencing process and mechanism of seawater intrusion on groundwater Fe in coastal zones, the local groundwater in Buzhuang Town, together with those in the neighboring area where no seawater intruded, was sampled and comparatively analyzed, and the static simulation experiments were also performed in laboratory. The local groundwater has Fe levels of 6.09–196.96 μg/L, with an average of 73.38 μg/L, but groundwater Fe levels from the neighboring area are 1.3–17.7 times of those in local groundwater. Such facts indicate the groundwater Fe levels decreased due to seawater intrusion. The groundwater Fe levels are significantly negatively correlated with pH, significantly positively correlated with Ca2+, Mg2+, and positively correlated with SO42−. The simulation experiments indicate leached Fe increases with a greater mixture of seawater, increasing concentrations of NaCl and CaCl2, but decreases with increasing NaHCO3 concentrations. Fe(OH)2 and Fe(OH)3 minerals are super-saturated because of the high pH and high OH− concentration resulting from seawater intrusion. By this way, the dissolving ability of groundwater Fe is restricted. Therefore, pH is the key factor determining groundwater Fe levels in coastal zones. Another, the decreasing of Ca2+, Mg2+ in groundwater decreases Fe levels because of the co-precipitation and deactivation of groundwater Fe. Salt effect and NaHCO3 contribute less to groundwater Fe levels because of the restriction of maximum Fe solubility by high OH− and super-saturation of Fe-bearing minerals. The influencing model of groundwater Fe levels under the effect of seawater intrusion is forwarded.

Optimization of SO2 and NOx sequential wet absorption in a two-stage bioscrubber for elemental sulphur valorisation.

Flue gases contain SO2 and NOx that can be treated together for elemental sulphur recovery in bioscrubbers, a technology that couples physical-chemical and biological processes for gaseous emissions treatment in a more economic manner than classical absorption. Sequential wet absorption of SO2 and NOx from flue gas is thoroughly studied in this work in a two-stage bioscrubber towards elemental sulphur valorisation pursuing reuse of biological process effluents as absorbents. The optimal operating conditions required for SO2 and NOx absorption in two consecutive spray absorbers were defined using NaOH-based absorbents. Overall, removal efficiencies of 98.9% and 55.9% for SO2 and NOx abatement were obtained in two in-series scrubbers operated under a gas contact time of 1 and 100 s, and a liquid-to-gas ratio of 7.5 and 15 L m-3, respectively. Higher NOx removal efficiency to clean gas emission was obtained by oxidants dosing in the absorber for NOx absorption. High NaHCO3 concentration in a two-stage bioscrubber effluent was exploited as alkaline absorbent for flue gas treatment. The performance of scrubbers using an absorbent mimicking a reused effluent exhibited the same removal efficiencies than those observed using NaOH solutions. In addition, the reuse of bioprocess effluent reduced reagents' consumption by a 63.7%. Thus, the two-stage bioscrubber proposed herein offers an environmentally friendly and economic alternative for flue gas treatment.

Influence of Edible Starch and Sodium Bi-carbonate on Postharvest Quality of Minimally Processed Carrot and Potato

The demand for healthy and ready-to-eat products has been growing steadily over the years. However, these products are very susceptible to spoilage and have a short shelf-life. In this research, edible coatings based on edible starch (aloe vera gel) and NaHCO3 were applied on fresh-cut vegetable samples (carrot and potato), and the changes in their bio-chemical properties and microbial changes were monitored during 6 days of storage at 4ºC. Two factor experiments, Factor A; postharvest treatments (different concentration of aloe gel and NaHCO3) and Factor B; two vegetable species (Carrot and Potato) were laid out in a Completely Randomized Design (CRD) with three replications. Different concentration of aloe vera gel and NaHCO3 solutions were prepared as per treatment. The prepared slices of vegetable species were treated with different treatment combinations and stored in 200 g capacity polyethylene bags sealed under air, vacuum or modified active atmosphere and then bio-chemically (Titratable Acidity (TA), Ascorbic Acid (AA) content, Total Soluble Solids (TSS), Reducing Sugar (RS), Non-reducing Sugar (NRS), pH) and microbiologically assessed. Higher rate of edible starch (30%) + NaHCO3 (2%) treated potato (CT12) showed the superior performance on TA (1.290), TSS (5.200% Brix), NRS content (0.340) and pH (4.773% Brix) compare to control and other interaction treatments of the study at 6 days after storage while untreated potato (T0) showed statistically lower AA (6.575 mg/25 g) TA (0.464) TSS (3.856), pH (3.827) NRS (0.133). Growth of bacterial colonies on NA media had statistically highest (14.00) in untreated potato and lowest (5.00) in T12 treated potato while fungal colonies on PDA media range of 4.00 to 11 at 6 DAS. The study may help small-scale establishments to increase the shelf-life of minimally processed vegetables.

Elucidating the differences in the carbon mineralization behaviors of calcium and magnesium bearing alumino-silicates and magnesium silicates for CO2 storage

Engineering the permanent storage of CO2 in earth-abundant Ca- and Mg-bearing silicate and alumino-silicate rocks and minerals as carbonates requires a fundamental understanding of the extents of carbonate conversion that can be achieved at conditions relevant to geologic formations. While many studies have reported the reaction rates and the carbonation extents of specific minerals, the data is limited in terms of reaction conditions and the mineral samples were relatively pure to start with. Thus, understanding of the effect of the chemical and mineralogical heterogeneity on the carbon mineralization behaviors of various minerals and rocks in geologic conditions is lacking. Therefore, this study investigated the reactivities of a selection of minerals and rocks such as (a) Mg-rich olivine (Mg1.74Fe0.26SiO4) as previously reported by Gadikota and co-workers (2014), [1] labradorite (plagioclase feldspar with Ca0.53Na0.47Al1.53Si O8), (b) anorthosite (a mixture of plagioclase (Ca0.98Na0.02Al1.98Si2.02O8), olivine (Mg1.32Fe0.68SiO4) and magnetite (Fe3O4)), and (c) basalt (a fine-grained volcanic rock containing a mixture of plagioclase (Ca0.6Na0.4Al1.6Si2.4O8), calcic pyroxene (~Mg0.48, Fe0.52CaSi2O6) and low Ca pyroxene (~Mg0.48Fe0.52SiO3)), that are relevant to CO2 storage. The reaction conditions were also selected to mimic the conditions relevant to geologic CO2 storage sites (Tmax = 185 °C, Pmax = 164 bar, 0–1 M NaHCO3, 0–1 M NaCl, 1.0 M NaCl + 0.64 M NaHCO3). Our studies show that the extents of carbonation of olivine, labradorite, anorthosite, and basalt are 85, 35, 19 and 9%, respectively, when reacted for three hours at 185 °C, PCO2 of 139 atm in 1.0 M NaCl + 0.64 M NaHCO3 with 15 wt% solid reactant and a stirring rate of 800 rpm. Further, our results indicate that increasing the reaction temperature over the range of 90 to 185 °C, and increasing the concentration of NaHCO3 over the range of 0 to 1 M, both enhance the extent of carbon mineralization. On the other hand, increasing the partial pressure of CO2 from 64 atm to 169 atm and raising the concentration of NaCl to 1.0 M have no significant effects within the time-scale of these experimental studies. Comparison of our results with previous studies suggests that the reactivity of Ca- and Mg-bearing alumino-silicates is lower compared to Ca- and Mg-bearing silicates.

Evaluation Solvent Level Effect on Sugar Yield during Microwave-Assisted Pretreatment

An efficient pretreatment step is essential to ensure maximum and economical recovery of the fermentable sugar from enzymatic hydrolysis of lignocellulosic biomass. Microwave-assisted pretreatment was found to be a good alternative of conventional heating pretreatment of acid or alkali due to its direct heating of sample which reduce the energy consumption. The present study aims to evaluate the effect of using very diluted solvent (acid and alkali) on monomeric sugar yield during microwave-assisted pretreatment of lignocellulosic biomass (sago palm bark wastes). The changes of the surface structure of untreated and pretreated lignocellulosic biomass were detected using SEM analysis. Three solvents were employed at three concentrations (0.01, 0.05 and 0.1 N). The solvents that utilized in the microwave-assisted pretreatment were sulphuric acid (MA), sodium hydroxide (MH) and sodium bicarbonate (MB) and compared with distilled water (MW). Sago palm bark (SPB) was soaked in these solvents as a substrate at 5% w/v and subjected to microwave power at 800 W in a modified household microwave oven for 5 minutes. Immersing feedstock in distilled water and heating using microwave heating released 5.32 mg/g of monomeric sugar. Highest yield of monomeric sugar was found using 0.1N H2SO4 which yielded 10.28 mg/g during. Applying the pretreatment using the similar concentrations of NaOH and NaHCO3 released 9.35 and 4.31 mg/g of monomeric sugar, respectively. Decreasing chemical solvent level from 0.1 to 0.05 and 0.01 N shows a negative influence on sugar yield for MA and MH pretreatment while MB pretreatment displays a positive effect by extracting some useful components such as xylose.

Effects of sodium salt stress on seed germination of typical annuals in a desert-oasis ecotone of Hexi Corridor, China

We assessed the effects of different concentrations of salts (0, 40, 80, 120, 160 and 200 mmol·L-1) on the seed germination and re-germination of six typical annuals (Gramineae: Setaria viridis, Chloris virgata and Eragrostis minor; Chenopodiaceae: Bassia dasyphylla, Salsola ruthenica and Corispermum mongolicum) in autumn of current year and next spring, with NaCl and NaHCO3 as neutral sodium salt and alkaline sodium salt. The results showed that NaCl and NaHCO3 significantly affected seed germination of the six species. The inhibition effect of NaHCO3 on seed germination was stronger than NaCl. When the concentration of NaHCO3 reached to 160 mmol·L-1, germination rates of the six species were low. However, when the concentration of NaCl reached to 200 mmol·L-1, the germination rates of the six species were still high. The germination (2.8%-20.0%) and re-germination rates (3.3%-20.0%) in current autumn were much lower than those in next spring, with values of 21.7%-81.6% and 5.0%-41.1%, respectively. In autumn, most of the current year's seeds kept dormancy, but the dormancy weakened in next spring. The salt tolerance of seeds of the six annual species was in the order of C. virgata > S. viridis > S. ruthenica > B. dasyphylla > C. mongolicum > E. minor.

Macromolecular Structure of a Commercial Humic Acid Sample

The molecular structure of a commercial sample of humic acids (HA) was investigated by membrane dialysis experiments (MD) and low-pressure size-exclusion chromatography (LP-SEC). MD showed that HA molecules were retained by dialysis membrane with a cut-off of 6–8 kDa, independently from HA concentration (15 or 150 mg L−1), NaHCO3 concentration (0.005–2.0 mol L−1), and from propan 2-ol (0–5 v/v %). SEC experiments at low pressure gave chromatograms with a broad peak, with an elution volume between those of the globular proteins bovine serum albumin (molecular weight = 66.5 kDa) and lysozyme from egg (molecular weight = 14.4 kDa). The pattern of the chromatogram did not vary with HA concentration, and second-run chromatograms of single eluted fractions showed relatively sharp peaks. From these data, we reveal that the commercial HA sample analysed has a macromolecular structure rather than being a supramolecular aggregate of relatively small molecules, as recently proposed for some samples of HA obtained from different sources.

β-Carotene Production from Dunaliella salina Cultivated with Bicarbonate as Carbon Source.

Bicarbonate has been considered as a better approach for supplying CO2 to microalgae cells microenvironments than gas bubbling owing t°Cost-effectiveness and easy operation. However, the β-carotene production was too low in Dunaliella salina cultivated with bicarbonate in previous studies. Also, the difference in photosynthetic efficiency between these tw°Carbon sources (bicarbonate and CO2) has seldom been discussed. In this study, the culture conditions, including NaHCO3, Ca2+, Mg2+ and microelement concentrations, were optimized when bicarbonate was used as carbon source. Under optimized condition, a maximum biomass concentration of 0.71 g/l and corresponding β-carotene content of 4.76% were obtained, with β-carotene yield of 32.0 mg/l, much higher than previous studies with NaHCO3. Finally, these optimized conditions with bicarbonate were compared with CO2 bubbling by online monitoring. There was a notable difference in Fv/Fm value between cultivations with bicarbonate and CO2, but there was no difference in the Fv/Fm periodic changing patterns. This indicates that the high concentration of NaHCO3 used in this study served as a stress factor for β-carotene accumulation, although high productivity of biomass was still obtained.

Investigation of biomass productivity from Nannochloropsis gaditana via response surface methodology using MATLAB

This study aimed to investigate biomass productivity to produce bioethanol from Nannochloropsis gaditana grown in Johnson’s medium including different concentrations of macronutrients. For this study, we prepared various concentrations of KNO3 (0.1–2 g/L), NaHCO3 (5–50 g/L) and KH2PO4 (0.05–0.8 g/L). In addition, central composite design (CCD) was used to optimize biomass productivity for acquiring the maximum biomass productivity. It was found that biomass concentration may vary with macronutrient concentrations. According to the experimental results, the maximum biomass concentration was found in 0.5, 20 and 0.8 g/L of KNO3, NaHCO3 and KH2PO4, respectively. The maximum experimental biomass yield of 2.04 g/L was obtained at these optimum conditions. These results showed that Nannochloropsis gaditana can be used for bio-ethanol production after optimization of macronutrient concentration.

Osteoclast and osteoblast responsive carbonate apatite coatings for biodegradable magnesium alloys

ABSTRACT Corrosion-control coatings which can enhance bone formation and be completely replaced by bone are attractive for biodegradable Mg alloys. Carbonate apatite (CAp) and hydroxyapatite (HAp) coatings were formed on Mg-4 wt% Y-3 wt% rare earth (WE43) alloy as a corrosion-control and bioabsorbable coating in the coating solution with various concentrations of NaHCO3. The incorporation of carbonate group in apatite structure was examined using X-ray diffraction and Fourier transform infrared spectroscopy. Rat osteoclast precursor and MC3T3-E1 osteoblast cells were cultured on the CAp- and HAp-coated WE43 to examine the osteoclastic resorption and the alkaline phosphatase (ALP) activity, respectively. Mg ions in the used medium were quantified to examine the corrosion-control ability. The NaHCO3 addition in the solution resulted in the formation of B-type CAp in which the phosphate group of apatite structure was substituted with the carbonate group. The osteoclastic resorption was observed only for the CAp coatings as the cracking of the coatings and the corrosion of substrate WE43 strongly localized under osteoclast cell bodies. The CAp and HAp coatings significantly enhanced the ALP activity of osteoblasts. The CAp-coated WE43 specimens showed 1/5 smaller amount of Mg ion release than the uncoated WE43 on the first day of culturing osteoblasts. For the subsequent 22 days, the Mg ion release was reduced to 1/2 by the CAp coatings. In the presence of osteoclasts, the CAp coatings showed slightly lower corrosion protectiveness than the HAp coating. It was demonstrated that the CAp coatings can be a bioabsorbable and corrosion-control coating for biodegradable Mg alloys.

Germination of Solanum nigrum L. (Black Nightshade) in Response to Different Abiotic Factors

ABSTRACT: Solanum nigrum L. (black nightshade), an annual to short-lived perennial weed, has become a problem weed in farming systems in central China. Laboratory and greenhouse experiments were conducted to examine the influence of various abiotic factors on seed germination of black nightshade to develop effective weed control programs. Seeds germinated at a range of constant temperatures from 15 to 30 oC, but no germination occurred at temperatures below 10 oC or above 35 oC. Seeds also germinated at alternating temperature regimes from 15/5 to 40/30 oC, with maximum germination (> 93.5%) at the alternating temperatures of 25/15 and 30/20 oC. Germination decreased as osmotic potential became more negative, and no germination was observed at ≤ -0.8 MPa. Moreover, germination was reduced by saline and alkaline stresses and no germination occurred at ≥ 200 mM NaCl or ≥ 150 mM NaHCO3 concentrations. Seed germination was not significantly affected by pH values from 5 to 10. Seedling emergence was significantly affected by burial depth with maximum emergence (93.1%) at 1 cm depth.

Helicobacter pylori Eradication Using Laser Endoscope and Methylene Blue.

Helicobacter pylori (H. pylori) eradication has become increasingly unsuccessful due to the prevalence of antibiotic resistance. To address this global issue, a novel strategy for eradication without antibiotics must be developed. The purpose of this study was to examine the effect of methylene blue (MB) with sodium bicarbonate (NaHCO3) on H. pylori using photodynamic antimicrobial chemotherapy. MB was basified using NaHCO3. The basic effect of MB with NaHCO3 was examined using an endoscope equipped with a laser light source. H. pylori was smeared on the culture media with basic MB, followed by illumination at approximately 1,100 lux for 10 and 20 seconds.After 4 days of culture, the basic effects were determined according to the bacterial growth. The basic effects of MB appeared at a pH from 8.6 to 9.0 and at NaHCO3 concentrations between 2% and 6.5%. MB concentrations of > 0.05% exhibited the basic effects. The duration of irradiation had no remarkable effects. Our results showed that the laser endoscope and basic MB were effective for H. pylori eradication.