Magnesium Ion Concentration Research Articles

Recombinase polymerase amplification combined with lateral-flow dipstick for rapid detection of Prorocentrum minimum

The dinoflagellate Prorocentrum minimum is a common harmful algal bloom-forming microalgal species worldwide. Because of its harmfulness, accurate detection of P. minimum by convenient method has become a hotspot for field monitoring of this alga. The recently developed nucleic acid isothermal amplification technology is a promising tool for diagnosis and on-site detection of harmful microalgae. In this study, a novel assay based on isothermal amplification referred to recombinase polymerase amplification (RPA) combined with lateral-flow dipstick (LFD) was established for the detection of P. minimum. The specificity of the proposed RPA-LFD was validated by test with control algae. Various RPA conditions including amplification time, amplification temperature, and magnesium ion concentration in the amplification reaction were optimized. The RPA-LFD displayed a stable performance for the detection of P. minimum that is not disturbed by non-specific species. The optimal RPA-LFD could recognize the target algal species from water samples with a cell density of 10 cells mL−1 within 30 min, displaying a detection limit that was 10-fold lower than that of conventional PCR. The practicability of the proposed RPA-LFD was also confirmed by test with natural samples. In conclusion, the developed RPA-LFD is promising for rapid on-site detection of P. minimum in the future.

Electrochemical detection of calcium and magnesium in water bodies

The design, fabrication, and implementation of novel flexible sensors for electrochemical detection of multiple minerals such as calcium and magnesium in water bodies are presented in this paper. 3D printing technique was utilized to form the master moulds for developing the sensor prototype. The 3D printed moulds were developed initially using Poly Lactic Acid as the printing filament. Multi-Walled Carbon Nanotubes and Polydimethylsiloxane were used for forming the electrodes and substrates of the sensor patches, respectively. The casting of Multi-Walled Carbon Nanotubes powder and Polydimethylsiloxane were done on the 3D printed moulds. The electrodes were patterned in an interdigitated manner to operate on the impedimetric principle. The passive elements of the equivalent circuit of the interdigitated sensors were determined using Complex Non-Linear Least-Square Curve Fitting software. The total change in impedance concerning differently concentrated solutions was due to different resistive and reactive elements of the sensors. The resistance, reactance, and impedance values from the sensor patches were analysed during the experiment for calcium and magnesium solutions. Experimental outcomes proved that the sensor was able to differentiate various concentrations of calcium and magnesium ions between 1 ppm and 200 ppm solutions. The reproducibility, repeatability, and reusability of the sensors were also tested to propose the developed sensors as an alternative solution for the determination of calcium and magnesium ions from unknown samples.

Importance of Lowered Ionized Magnesium Concentrations in Elderly Hypertensives

In recent publications a magnesium deficiency in elderly is up to 50%, depending on co-morbidity, drugs and nutritional status [1,2]. On the other hand, it is well known that a magnesium insufficiency is a pathogenic factor in the development of primary hypertension [2-11]. In this context calcium magnesium antagonism, sodium magnesium antiport, disturbed vitamin D metabolism or disturbed magnesium channels (TRPM 6 and 7) are of special interest [1-7]. For these reasons magnesium metabolism was of interest in elderly hypertensives. Ionized magnesium is the active form and was measured additionally. Up to now it is not clear whether there is a correlation between plasma or serum magnesium concentrations and ionized magnesium content.

Teredinibacter waterburyi sp. nov., a marine, cellulolytic endosymbiotic bacterium isolated from the gills of the wood-boring mollusc Bankia setacea (Bivalvia: Teredinidae) and emended description of the genus Teredinibacter.

A cellulolytic, aerobic, gammaproteobacterium, designated strain Bs02T, was isolated from the gills of a marine wood-boring mollusc, Bankia setacea (Bivalvia: Teredinidae). The cells are Gram-stain-negative, slightly curved motile rods (2–5×0.4–0.6 µm) that bear a single polar flagellum and are capable of heterotrophic growth in a simple mineral medium supplemented with cellulose as a sole source of carbon and energy. Cellulose, carboxymethylcellulose, xylan, cellobiose and a variety of sugars also support growth. Strain Bs02T requires combined nitrogen for growth. Temperature, pH and salinity optima (range) for growth were 20 °C (range, 10–30 °C), 8.0 (pH 6.5–8.5) and 0.5 M NaCl (range, 0.0–0.8 M), respectively when grown on 0.5 % (w/v) galactose. Strain Bs02T does not require magnesium and calcium ion concentrations reflecting the proportions found in seawater. The genome size is approximately 4.03 Mbp and the DNA G+C content of the genome is 47.8 mol%. Phylogenetic analyses based on 16S rRNA gene sequences, and on conserved protein-coding sequences, show that strain Bs02T forms a well-supported clade with Teredinibacter turnerae . Average nucleotide identity and percentage of conserved proteins differentiate strain Bs02T from Teredinibacter turnerae at threshold values exceeding those proposed to distinguish bacterial species but not genera. These results indicate that strain Bs02T represents a novel species in the previously monotypic genus Teredinibacter for which the name Teredinibacter waterburyi sp. nov. is proposed. The strain has been deposited under accession numbers ATCC TSD-120T and KCTC 62963T.

Effects of magnesium ions in microbial cells adhesion of attached growth system for the enhancement of biogas production

This research aims to improve the biogas production by employing cell immobilisation technique under thermophilic conditions. The thermophilic fermentative biogas production was carried out by immobilising the anaerobic sludge obtained from palm oil mill treatment plant on granular activated carbon (GAC) in repeated batch mode. Different concentration of magnesium ions (Mg2+) (0.25, 0.5, 0.75, 1.0 and 1.5 g/l) on biogas production was investigated at 60°C with an initial sucrose concentration of 5 g/l as feedstock. The effect of Mg2+ supplementation at the initial stage of immobilisation process is important to increase the formation of biofilm in the attached growth system. This study had found that Mg2+ could enhance the biogas production capacity with optimum Mg2+ concentration of 0.75 g/l.

Possibility of using thermal water from the Nizhne-Paratunskiye springs of Kamchatka to create pharmaceutical and cosmeceutical compositions

The purpose was to determine content of the main active components — macro- and microelements — in thermal water, in the intermediate product (concentrate) and in the dosage form (spray). Determining the saturation of the dosage form with active components was the purpose as well. Materials and methods. Thermal water from the Nizhne-Paratunskiye springs of Kamchatka, concentrate from this water, composition with a concentrate of thermal water in the form of spray were used. Determination of the content of calcium and magnesium ions was carried out by titrimetric method on the basis of forming a complex compound with Trilon B. Validation of the used methods was carried out. Its repeatability was evaluated within one day to determine the precision of the technique. The intra- and inter-assay precision of the validated method was also evaluated. Solutions containing calcium and magnesium ions in concentrations of 80–120 % from the declared amount were prepared to determine linearity of the methods. Results. The content of magnesium and calcium ions in the raw material (3.63 and 284.41 mg/l, respectively), the intermediate product — concentrate (35.38 and 2723.00 mg/l) and the finished form — spray (11 and 778 mg/l) was determined. Conclusion. As a result of studies based on the determination of the content of macro- and microelements in the spray, concentrate, dosage form, it was found that it is possible to achieve an increase in the content of the trace elements in thermal water, thanks to its 10-fold concentration, which will reduce the cost of transportation. Using the concentrate it is possible to achieve the required salt concentration in the finished product. The developed spray has a complex of auxiliary substances that provide the required consistency of the composition, easily releases hydrothermal water, is chemically indifferent, compatible with salts, absorbs liquid well, is easily removed from the application site, leaves no traces.

The mutual effects of injected fluid and rock during imbibition in the process of low and high salinity carbonated water injection into carbonate oil reservoirs

Abstract During water injection into oil reservoirs, interactions occur between injected water and the reservoir rock. The interactions are enhanced when dissolved carbon dioxide (CO2) is used in injectable fluid in enhanced oil recovery (EOR) process, especially in carbonate reservoirs. With the dissolution of CO2 in water, carbonic acid is formed. The formed acid reacts with the carbonate salts in the rock (calcium carbonate and magnesium carbonate) and dissolves them. The dissolution causes a change in the properties of the rock, including wettability, porosity and permeability. In this study, variations of porosity, permeability, rock mass and wettability during carbonated water imbibition were measured based on direct measurements of porosity, permeability, rock weight and contact angle. In addition, changes in the concentration of calcium, magnesium and bicarbonate ions from the dissolution of carbonate rocks in injected water were measured by sampling and titration of water. The experiments were carried out at a constant temperature and the pressure parameter was considered to be variable in order to investigate its effect on the cases discussed. The effect of base fluid salinity was investigated in two salinities equal to the initial salinity and salinity from the dilution of seawater. The carbonated water imbibition in oil-saturated plugs yields 48, 56, 69 and 75%, at pressures of 500, 1000, 1500, and 2000 psi, respectively, and low salinity resulted from the dilution of seawater as the base fluid. In addition to the dependence of changes in rock parameters on the pressure and salinity of the base fluid, the results show that porosity variations, permeability and, most importantly, wettability of the rock are so much that they can be effective in activating the process of the imbibition and increasing its power in oil production.

Water Softening and Disinfection Using an Electrolysis Unit with a Filtering Cartridge

The removal of a set of contaminations consisting of hardness salts, iron, humic substances, and microorganisms by using a unit combining electrochemical treatment and filtration is investigated. Constructively, the electrochemical unit is based on the flask of a standard domestic water filter equipped with a filtering cartridge, in the form of hollow cylinder, filled with sintered activated carbon. A graphite anode is placed on the inside of the cartridge, and a steel mesh cathode is placed coaxially outside the cartridge. In experiments, we use tap water from the Kiev’s water supply network characterized by a total hardness of 4.5 mg-eq/L (the concentrations of calcium and magnesium ions are 70 and 12 mg/L, respectively) and a carbonate alkalinity of 3.6 mg-eq/L. Model solutions are prepared by adding either iron(II) (as FeCl2) or humic acid to water to a concentration of 7 and 20 mg/L, respectively; Bacillus subtilis is also added to a concentration of 104 CFU/L. To evaluate the effectiveness of using the filtering cartridge, water electrolysis is carried out in two configurations: in the presence and absence of the filtering cartridge, without separating the electrode compartments. In experiments without the cartridge, the current slightly decreases from 0.5 to 0.45 A (i.e., by only 10%), while the hardness falls by only 12%. In experiments with the cartridge, the current falls to a steady value amounting to 40% of its initial value, while the hardness falls from 4.6 to 0.28 mg-eq/L (i.e., by 93%) and the concentrations of iron, humic substances, and bacteria decrease from 7 mg/L, 20 mg/L, and 5 × 104 CFU/mL to 0.01 mg/L, 1 mg/L, and 0 CFU/mL, respectively. The energy consumption of the unit is up to 2 kWh/m3.

Experimental Study on Diffusion Process of Sulfate Ion in Cemented Gangue Backfill Material

Cemented gangue backfill material (CGBM) is made of coal gangue, fly ash, cement, and water. The backfill body will be corroded by mine water that contains different kinds of corrosive ions. The paper mainly aimed to study the diffusion process of sulfate ion () in CGBM. Soluble salt solutions with different concentrations are prepared to simulate various mine water. The concentration was measured by layered sampling method and chemical analyzing method. The diffusion coefficient was calculated according to the second Fick’s law. Scanning electron microscope (SEM) and X‐ray diffraction (XRD) were used to analyze the degradation mechanisms. The experimental results showed that the concentration increases in CGBM when the external sulfate solutions concentration increases. With the increasing of magnesium ion (Mg2+) concentration and bicarbonate ion () concentration in the external corrosion solutions, the diffusion coefficient of was increased, and has more significant effects than Mg2+. reacting with CGBM produced ettringite and gypsum. The ettringite and gypsum changed the pore structure of hardened CGBM and affected the compressive strength of hardened CGBM. Studying the diffusion of can contribute to predicting the service life of CGBM.

Study Investigates Smart Waterflooding in Sandstone Reservoirs

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 193238, “Investigation of Smart Waterflooding in Sandstone Reservoirs: Experimental and Simulation Study, Part 2,” by Hasan N. Al-Saedi, SPE, Missouri University of Science and Technology and Missan Oil Company; Ralph E. Flori, SPE, Missouri University of Science and Technology; and Alsaba Mortadha, Australian College of Kuwait, prepared for the 2018 Abu Dhabi International Petroleum Exhibition and Conference, 12–15 November, Abu Dhabi. The paper has not been peer reviewed. In this paper, the authors consider the effect of water chemistry on water/rock interactions during seawater and smart waterflooding of reservoir sandstone cores containing heavy oil. Oil recovery, surface-reactivity tests, and multicomponent reactive-transport simulation were conducted to understand smart waterflooding better. The authors determine that lowering magnesium-ion (Mg2+) concentration results in lower additional oil recovery, and that lowering calcium-ion (Ca2+) concentration leads to higher additional oil recovery. Introduction “Smart water” (SW) can be defined as a water engineered by manipulating the ionic composition (adding or removing ions) regardless of the resulting salinity. An upward pH shift has been reported in the literature during low-salinity (LS) and/or smart waterflooding. That upward shift modifies the wettability of sandstone, thereby increasing oil recovery. When high salinity is displaced by LS water, Ca2+ will be desorbed from the clay surface because ion exchange occurs between hydrogen (H+) and Ca2+ at the negative sites of the clay surface. The organic materials will be then desorbed from the clay because of the reaction between the protonated basic and the acidic materials with hydroxide. The authors’ investigations on free-clay sandstone provided a different insight into such reactions. The observations from chromatographic columns of quartz showed an increase in the acetate detachment from the quartz surface with a significant pH jump during LS waterflooding. The oil-recovery observations from the quartz column supported the proposed mechanism. Previous systematic laboratory works indicated that the abundance of Mg2+ in the formation water (FW) is more effective than Ca2+ for a higher LS enhanced-oil-recovery (EOR) effect. Conversely, the abundance of Ca2+ in the injected LS water has a larger effect on LS EOR. When Mg2+ was present in the LS water, no oil-recovery improvement occurred. Methodology Brines. Synthetic FW and SW were prepared by dissolving sodium chloride (NaCl), calcium chloride (CaCl2), and magnesium chloride (MgCl2) in deionized water. Crude Oil. A reservoir crude oil was de-livered from eastern Kansas from the Bartlesville sandstone reservoir. The crude oil had a viscosity of approximately 600 cp at ambient temperature. The density is 0.83 gm/cc at 20°C. Reservoir Rock Description and Core Preparation. Five Bartlesville sandstone reservoir cores were drilled from the original 3-in. diameter to a 1-in. diameter preserved core from eastern Kansas. The preserved reservoir sandstone cores were delivered with 3-in. diameter. The most abundant mineral was quartz, followed by clays.

DETECTION OF CAMPYLOBACTER SPP. WITH REAL-TIME POLYMERASE CHAIN REACTION

Bacteria of Campylobacter genus are ones of the main zoonotic pathogens causing human and animal diseases. Campylobacter organisms are microaerophiles and, therefore, require low oxygen concentration (3–5%) and high carbon dioxide concentration (3–10%) for their growth. They use amino acids rather than carbons as a source of energy. Classical bacteriological methods for Campylobacter spp. detection are not always successful due to diffi culties in creating optimal conditions for their growth. Therewith, development and implementation of molecular methods for Campylobacter detection and identifi cation are of current importance. Assay for qualitative Campylobacter spp. detection with real-time polymerase chain reaction using CFX-96 thermocycler was optimized. Highly specifi c segment of 16S rRNA gene allowing identifi cation of 6 Campylobacter species: C. jejuni, C. coli, C. lari, C. upsaliensis, C. helveticus и C. hyointestinalis was selected as an amplifi cation target. Optimal magnesium ion concentration (2.5 мМ) and primer annealing temperature (58 °С) were determined. Eighteen reference strains of various bacteria were tested. Only tests of Campylobacter genus strains gave positive results. The method sensitivity was 40 target molecules. The said method was used for testing 76 samples of raw materials of animal origin. Campylobacter spp. genome was detected in 18 samples. Obtained results showed that the optimized variant of real-time polymerase chain reaction based on 16S rRNA gene amplifi cation was a specifi c, sensitive, rapid, reproducible and accurate method for qualitative detection of Campylobacter spp. in samples of raw animal materials.

Irrigative assessment of Sasyk water quality

The transformation of the salt-water liman Sasyk into a fresh water reservoir through its separation from the sea by a dam and connection with the Danube by a canal caused certain ecological problems. One of them was that during the first decades the expected water irrigation conditions were not achieved because of salt infiltration from the bottom sediments. Use of high-salinity water led to soil salinization. As a result, Sasyk ceased to be considered as an object for irrigation purposes. At present, the process of Sasyk water quality formation stabilized and the need for land irrigation is still of great importance.
 The authors of the researches devoted to solving the environmental problems of Sasyk classify the irrigation properties of water as average and maximum values of mineralization. However, these properties can change significantly over the year and therefore the water may belong to different irrigation categories (classes). The purpose of this study is to evaluate the irrigation properties of Sasyk water and their variability based on the hydrochemical observations conducted near the village of Trapivka, at base pumping station GNS-2 during warm periods of a year from 2007 to 2017.
 The article presents an overview of different methods of irrigative water assessment and a detailed typification of the irrigative water using the water typification suggested by Aliokin O.A. The research includes the evaluation of the Sasyk water quality as per the studied methods. The authors discovered the fact that mineralization of Sasyk water during a warm period is within the 1-3 g/dm3 range in 90-95% of cases under study and only in 5-10% of those its value is less than 1 g/dm3. The ratio of main ions in Sasyk water may be of the following subtypes: IIa (30%), IIb (50%), ІІIb (10%) and ІІIc (10%). The mineral composition is mainly represented by the toxic salts such as NaCl, Na2SO4, MgSO4. Their content in the water does not exceed 2.0 g/dm3. Among the toxic salts NaCl is the one that prevails. Under normal conditions the mineralization of the water and the content of sodium and magnesium ions in Sasyk contribute to salinization and soil alkalinization. To provide safe irrigation of all types of soil using the water from Sasyk its chemical melioration and dilution with low-mineralized water is required. At present, the irrigative properties of Sasyk water (mineralization, composition of toxic salts and their concentration) allow its use of for irrigation of light, permeant and drained soils.

Static and dynamic approach to estimation of spring water hardness cation content as a natural factor of groundwater formation

To assess the degree of influence of natural factors on the groundwater mineralization, it is proposed to simultaneously consider in a static and dynamic position the results of titrimetric determination of the total mineralization and concentration of calcium and magnesium ions in spring water. This is shown by the example of four springs located in the territory of Kaluga. The study made it possible to establish: the average annual background concentrations, as well as to justify the relative variable for groundwater in springs No. 1, No. 3 and No. 4 and the influence of the natural factor on the formation of the total hardness and concentration of calcium and magnesium ions in the study period, relatively stable for groundwater in spring No. 2 by the value of the molar ratio of the concentrations of calcium and magnesium ions.

Multimineral reactions controlling secondary phase evolution in a hyperalkaline plume

This paper presents a modelling study of the influence of a hyperalkaline leachate on a host rock in a geological disposal facility for low- to intermediate-level nuclear waste disposal, when compared with a 15-year experiment designed to simulate the geochemical and mineralogical evolution of the system. The hyperalkaline leachate may be produced by the interaction of groundwater with the cementitious backfill surrounding the waste form. The rock sample is from the Borrowdale Volcanic Group, which comprises orthoclase, quartz, dolomite, muscovite, haematite and calcite as the major mineral phases, with various kinetic dissolution/precipitation rates. Multimineral reactions with the multiple chemicals in the leachate are responsible for the variation in chemical concentration and temporal evolution of different primary and secondary phases observed in the experimental study. The temporal variation in the concentrations of calcium (Ca2+), silicate (SiO3 2−), magnesium (Mg2+) and carbonate (CO3 2−) ions and pH has been modelled, which agrees well with the experimental results. The mineral evolution process has confirmed that dolomite and calcium silicate hydrate (CSH) gel (CSH phases) will dissolve and generate new secondary phases, such as calcite and saponite-K over the 15-year experiment.

Radio-Telemetric Assessment of Cardiac Variables and Locomotion With Experimentally Induced Hypermagnesemia in Horses Using Chronically Implanted Catheters.

The objective of this study was to characterize the pharmacokinetics and pharmacodynamics of intravenous administration of magnesium sulfate to horses using a novel radio-telemetry system for physiologic signal capture. Five Horses were surgically implanted with a radio-telemetric carotid catheter. Implants were paired with a non-invasive telemetric unit which acquired a six lead ECG and 3-axis acceleration to assess activity acquired wirelessly in real-time for future analysis. Horses were exposed to a new stall environment before (baseline) and after 60 mg/kg (30 mL) of magnesium sulfate (MgSO4), or the same volume of 0.9% saline, administered intravenously in a blinded, random crossover design. Blood for pharmacokinetics, telemetric data, and body temperature were recorded serially for 24 h. Data were analyzed across time and between treatments. Significance was set at P < 0.05. Ionized magnesium concentration (Mg2+) increased and the Ca2+ to Mg2+ ratio decreased and persisted for 5 h after MgSO4 administration. Heart rate (HR) increased and mean arterial blood pressure (MAP) decreased for at least 6 h. Electrocardiogram (ECG) intervals (RR) decreased and (PR and QTc) increased in duration compared to controls indicating an increase in heart rate, and slower myocardial conduction in the MgSO4 group. Acceleration in all planes was less in the MgSO4 group compared to controls indicating decreased locomotion. This novel method permitted collection of physiologic signals without interference by handlers or animal restraint. An intravenous bolus of MgSO4 produced cardiac variable changes associated with the reduction of locomotion in these horses, and in a direction that may be causal. Locomotion was decreased when horses were first introduced into a new environment which reflects the calming effect desired in sport horses. Telemetric monitoring can be used as a model to elucidate the behavior and physiologic effects of other drugs. The administration of MgSO4 may be detected for regulatory purposes with the monitoring of Mg2+ and Ca2+ concentrations and their ratio.

Ocena wpływu wybranych jonów metali na efektywność transportu biernego i aktywnego imipraminy

The aim of the study was to evaluate the effect of zinc as well as magnesium or copper ions on the efficacy of passive transport of imipramine hydrochloride in in vitro model. According to results from passive transport, the next aim of the studies was to check the efficiency of active transport of imipramine hydrochloride in the presence or absence of zinc ions. The passive transport study was conducted in specially designed capsules, while CaCo-2 cell lines were used in active transport evaluation. Zinc, magnesium and copper content was determined by F-AAS method. The analysis of imipramine hydrochloride was performed using HPLC method. Mean concentrations of zinc, magnesium, and copper ions obtained in this experiment were as follows: 2.98, 1.34 and 3.52 mg/L, respectively. The presence of zinc ions increased the efficiency of active transport of imipramine hydrochloride by 39%. Furthermore, the transport of zinc ions in the presence of imipramine hydrochloride was 27% greater than that of the zinc-containing solutions without imipramine hydrochloride. The extending of the time of experiment from 30 to 60 minutes resulted in an increase in transport efficiency of more than 10% in both cases. The efficiency of passive and active transport of imipramine hydrochloride is influenced by the presence of Mg, Zn and Cu ions. The passive transport of imipramine hydrochloride after 90 minutes of experiment was the most effective in the presence of copper and zinc ions. Further studies conducted on the CaCo-2 cell line indicated a clear positive interaction of imipramine - zinc.

Relationship between Electrical Conductivity and Chemical Content of Rat Skeletal Muscle Impregnating Solution and Postmortem Interval.

Objective To study the mechanism of change of the electrical conductivity （EC） of rat skeletal muscle impregnating solution that occurs with the change of postmortem interval （PMI）. Methods Healthy Sprague-Dawley rats were killed and kept at about 25 ℃. Skeletal muscles were extracted at different PMI--immediate （0 d）, 1 d, 2 d, 3 d, 4 d, 5 d, 6 d, and 7 d, then mixed with deionized water to make impregnating solution with a mass concentration of 0.1 g/mL. The solution's EC and nine common chemicals in it, such as potassium ion, calcium ion, and chloride ion, were determined. Results EC increased gradually with the extending of PMI （P=0.024） during the 7 days after the rats' death. The content of uric acid （P=0.032）, urea nitrogen （P=0.013） and phosphorus （P=0.022） also increased during the extension. However, the content of magnesium ions decreased with extending of PMI （P=0.047）. The correlation between potassium ion, sodium ion, chlorine ion, calcium ion, creatinine and PMI were weak （P>0.05）. Conclusion The molecular basis of skeletal muscle EC change in rats after their death is the changes of uric acid, urea nitrogen, inorganic phosphorus and other chemical components. Furthermore, combine use of various indicators can improve the accuracy of the EC method to infer PMI.

Contamination-free visual detection of CaMV35S promoter amplicon using CRISPR/Cas12a coupled with a designed reaction vessel: Rapid, specific and sensitive

An ultrafast and convenient method for visually detecting CaMV35S promoter amplicon (amplified products) was established by using CRISPR/Cas12a system coupled with a designed reaction vessel. Genetically modified (GM) soybean (Roundup Ready®) powders containing CaMV35S promoter were employed as detection targets, which were amplified by loop-mediated isothermal amplification (LAMP). The CRISPR/Cas12a system directly mixed with amplified products at 37 °C for 5 min and detection results could be clearly identified by the naked eye under UV light (254 nm). A designed reaction vessel was employed to make operation easier and could effectively prevent contamination at the source. The CRISPR/Cas12a detection system was optimized in our study and the concentration of magnesium ions was proved to be important for the work of CRISPR/Cas12a system. The optimized concentration range of magnesium ions was between 10 mM and 12 mM. Besides, the activated Bst DNA polymerase also had little effects on CRISPR/Cas12a system. The developed method could significantly distinguish the specific and non-specific amplification. And as low as 0.05% transgenic contents in soybean powders could be detected. It would have the potential to be complementary to instrument-based ultrahigh sensitive method and provide a new solution for on-site rapid detection.

Magnesium modified calcium hydroxyapatite: An efficient and recyclable catalyst for the one-pot Biginelli condensation

Magnesium modified calcium hydroxyapatite Ca(10-x)Mgx(PO4)6(OH)2, 0 ≤ x ≤ 3, have been synthesised using double decomposition method. The resulting materials have been fully characterised by X-ray powder diffraction, chemical analysis and infrared spectroscopy. X-ray diffraction analysis shows that the obtained materials consist of a single phase having an apatitic structure. The catalytic activity of the synthesised compounds was tested on the one pot Biginelli reaction for the synthesis of 3,4-dihydropyrimidin-2-(1H)-one. The substitution of calcium by magnesium ions has a positive effect on the efficiency of the catalyst. Moreover, increasing the magnesium ion concentration in the apatite leads to better yields in Biginelli product and a faster rate of the reaction. The catalyst is easily recyclable can be used at least five times without significant change in activity.

Genome-wide association study identifies loci linked to serum electrolyte traits in Chinese Holstein cattle.

We aimed to identify QTL for serum electrolyte traits by performing a GWAS of calcium, chloride, sodium, potassium and magnesium ion concentrations in Chinese Holstein cattle. We detected five SNPs that had significant associations with calcium ion concentrations and identified GATA2 from Bos taurus chromosome (BTA)22 as having the highest significance. Among the genes with significant results, we speculate that TMEM123 might be related to calcium channel proteins according to the functions of the TMEM family.