Changes In Ca Concentration Research Articles

Impact of polyvinyl chloride (PVC) microplastic on growth, photosynthesis and nutrient uptake of Solanum lycopersicum L. (Tomato)

Microplastics (MPs) pollution and their impact on plants have become a global threat, but their effect at the molecular level remains scarce. This study aims to gain insight into the effects of polyvinylchloride microplastic (PVC-MP) on tomato plants at the genetic and protein levels. In this study, we found that increasing concentrations of PVC-MP (2.5, 5,7.5, and 10% w/w) in the soil did not cause any phytotoxic (chlorosis or necrosis) symptoms but it did result in a dose-dependent reduction in plant growth-related parameters, such as height, leaf area, stem diameter, and plant fresh and dry weight. Additionally, the number of secondary roots was reduced while the primary roots were elongated. Furthermore, PVC-MP also caused a significant decrease in light-harvesting pigments chlorophylls, and carotenoids while increasing the level of reactive oxygen species (ROS) and lipid peroxidation in plants. Microscopic analysis of the roots revealed the uptake of PVC-MP of size less than 10 μm. Micro- and macro-element analysis showed changes in concentrations of Ca, Cu, Fe, Mg, Mn, Ni, and Zn, upon PVC-MP exposure. Results from western blotting and q-PCR showed that higher doses of PVC-MP significantly reduced the CO2-fixing enzyme RuBisCO and D1 proteins of PSII at both protein and transcript levels. These findings suggest that lower levels of light-harvesting pigments, D1 protein, RuBisCO, and modulation of nutrient absorption are among the factors responsible for growth suppression in tomato plants upon exposure to PVC-MP. As tomato plants are economically significant crops, an increase in PVC-MP in agricultural fields may have a detrimental influence on crop production, resulting in economic loss.

Study of Mineral Composition and Quality of Fruit Using Vascular Restrictions in Branches of Sweet Cherry.

Calcium (Ca) and carbohydrate (CHO) supply in sweet cherry have been associated with fruit quality at harvest and during storage. There is little published information integrating CHO and Ca availability and distribution in sweet cherry and their effects on fruit quality. Accordingly, in the 2019-20 season, vascular restrictions were imposed on the phloem (girdling, G, stopping phloem flow) and xylem (transverse incision, S, cutting 50% of xylem cross-section area) of individual vertical branches of the sweet cherry combination 'Lapins'/Colt trained as Kym Green Bush system to modify mineral and CHO composition in fruit and associate such changes with quality at harvest and storage. The girdling to the phloem was used to induce changes in CHO distribution. The transverse incision to the xylem was a tool to modify Ca distribution. Five treatments (TR) were implemented: TR1-CTL = Control (without vascular restriction), TR2-G, at its base, TR3-G + G: at its base, and G further up at the change of year between the second and the third years of growth TR4--S and TR5-S + G. The vegetative (i.e., shoot and leaf growth), reproductive (i.e., fruit set and yield) development and stomatal conductance were monitored. Each branch was divided into the upper (1-and 2-year-old wood) and the lower (3-and 4-year-old wood) segments of the restriction applied. The quality and mineral composition (Ca, Mg, K, and N) of fruit borne on each segment were measured at harvest. The upper segment of TR3-G + G branches were harvested 10 d before the lower segment. The fruit from the upper segment of TR3-G + G was the largest, the sweetest, and had the higher titratable acidity concentration. However, fruits of this segment were the softest, had the lowest Ca concentrations, and had the highest ratios of N:Ca and K:Ca, compared with the other TRs. TR3-G + G branches developed the highest number of lateral current season shoots including shoots below the second girdling in the lower segment of the branch. This vegetative flow of growth would explain the mineral unbalance produced in the fruit from the upper segment of the branch. TR2-G did not register changes in fruit quality and mineral concentration compared with TR1-CTL. Surprisingly, the fruit from the branches with xylem restriction did not show changes in Ca concentration, suggesting that the xylem stream was enough to supply the fruit in branches without lateral shoot development. Fruit firmness was positively related to fruit Ca concentration and negatively related to the ratios of K:Ca and N:Ca.

Changes in calcium content and expression of calcium sensor-related genes during sand pear (Pyrus prifolia) fruit cracking

Fruit cracking is a physiological disorder and results in significant economic losses. Calcium (Ca) plays important roles in the pear fruit cracking process, however, the underlying molecular mechanism of fruit cracking induced by Ca is poorly understood. In the present study, using cracking susceptible pear genotype ‘4–5–73′, we investigated the changes in Ca content and Ca sensors-related gene expression in the peel and flesh samples of cracked and non-cracked fruit. Cracking symptoms started to appear on the peel at 9 weeks after anthesis (WAA), and the total cracking rate gradually increased during fruit development until 15 WAA. During the early fruit cracking period (9 to 12 WAA), the Ca content in the peel and flesh of cracked fruit was lower than that of non-cracked fruit. Transcriptome sequencing indicated that 17 Ca sensors-related genes were differentially expressed in cracked and non-cracked fruit peel at 13 WAA. Among them, PpCML11 displayed higher expression in the peel and flesh of cracking fruit than that of non-cracked fruit. In addition, a positive correlation was observed between the PpCML11 expression level and the Ca content in the flesh of non-cracked fruit. Taken together, the present study suggests that PpCML11 might be involve in the sand pear flesh development process, and could play an important role in response to biotic stress after fruit cracking.

Microstructural and dielectric properties of Ba0.45Mg0.05Sr0.5-x CaxTiO3 high entropy ceramics

Ba0.45Mg0.05Sr0.5-xCaxTiO3 (BMSCT) high entropy ceramics were prepared using a solid-state reaction process sintered at temperatures ranging from 1250 °C to 1400 °C. A change in Ca content significantly affects the crystalline phase and dielectric properties of the BMSCT ceramics. High resolution TEM observations and the analysis of respective images reveal a large number of intragranular on the nanoscale that are massively disordered and disturbed on the atomic level. The influence of Mg doping, resulting in a shift of the Curie point to −50 °C. For Ca-substitution (up to 10 at.%), a broad phase transition is observed in the BMSCT, and the Curie point is −30 °C. Comparing the dielectric constant at 1 MHz and 1 GHz, the permittivity of the BMSCT-9182 is only slightly inferior to the on at low frequency ～6%, but the one for BST is drastically decreased ～70% at microwave frequencies.

Change of Calcium Concentrations in Forest Soils by Plant Species and Soil Depth

One of the most important factors playing role in plant development is the nutrient element content of the soil. Being one of the fundamentally necessary macronutrients for plant nourishment, calcium (Ca) plays an important role in the growth and development of a plant. Thus, even though many studies have been carried out on the change of Ca concentration in agricultural soils, the number of studies examining this subject for forest soils is very limited. In the present study, it was aimed to compare the concentrations of Ca in soil and plant organs for the soils, where different forest trees are grown. Within this scope, leaf, bark, wood, cone, and root samples were collected from Turkish fir, black pine, Scotch pine, and Oriental beech species and soil samples were taken from the surface, mid-deep, and deep soil levels. Then, the Ca concentrations were compared. As a result, it was determined that Ca concentrations statistically significantly vary between leaves, roots, and woods of plants and between mid-deep and deep soils by species (p

Porewater geochemistry indicates methane seepage in the Okinawa Trough and its implications for the carbon cycle of the subtropical West Pacific

The Kuroshio Current, originating from the West Pacific Warm Pool and flowing through the Okinawa Trough, connects the equator and the subtropical West Pacific and plays an important role in the carbon cycle in the West Pacific Ocean. Previous studies have focused on the effects of surface export productivity and bottom redox conditions on the carbon cycle in the late Quaternary. Recent studies have demonstrated that methane seepages are very common in the Okinawa Trough, however, their significance for the carbon cycle remains not well understood. Here, methane seepages and sulfate-driven anaerobic oxidation of methane (SD-AOM) are constrained by the geochemical characteristics of porewater at site CSHC-4 (Length: 1555 cm) derived from the water depth of 934 m on the western continental slope of the Okinawa Trough. Using the △(DIC+ Ca2++ Mg2+)/△SO42− ratio, it is suggested that the sulfate reduction in the upper part of site CSHC-4 is dominated by organoclastic sulfate reduction (OSR), while that between 655 and 1055 cm is gradually dominated by SD-AOM with deepening depth. However, with the depletion of sulfate, the methanogenesis process predominates at the bottom of site CSHC-4. The depth of the sulfate-methane interface (SMI) and the methane diffusive flux of site CSHC-4 is calculated to be ∼1156 cm and ∼ 63 mmol m−2 yr−1, respectively. Near the SMI, the changes in concentrations of Ca2+, Mg2+, Sr2+ and ratios of Mg/Ca and Sr/Ca in the porewater indicate the possibility of the precipitation of authigenic high-Mg calcite in the sediments. In contrast, the increase in the concentration of Ba2+ in porewater below the SMI may imply the dissolution of barite (BaSO4). In addition, redox-sensitive elements in porewater exhibit various geochemical behaviours due to changes in redox conditions caused by SD-AOM. The above SD-AOM processes will affect the reconstruction of surface productivity and redox conditions of bottom water in the Okinawa Trough since the late Quaternary based on biogenic elements (e.g., Ca and Ba) and redox-sensitive elements (e.g., U and Cr), which requires careful evaluation. Therefore, our new findings illustrate the modern methane seepage in the Okinawa Trough and provide a reference for calculating the ancient carbon cycle in the subtropical West Pacific.

Leaf and Fruit Nutrient Concentration in Rojo Brillante Persimmon Grown under Conventional and Organic Management, and Its Correlation with Fruit Quality Parameters

This study aimed to evaluate the concentrations of the main macroelements in leaves and fruit grown following organic and conventional practices, and to relate them to physico-chemical parameters during commercial fruit harvests. Three samplings were carried out during fruit maturation. Nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) were determined in leaves and in two fruit flesh areas: basal and apical. Weight, color, firmness, soluble tannins (ST), and total soluble solids (TSS) were also evaluated in fruit. During the study period, the lowering leaf N concentration was accompanied by its increment in flesh. Leaf P and K lowered but did not imply changes in these concentrations in fruit. N, P, and K concentrations were higher in the apical area than in the basal flesh. No changes in Ca concentration occurred in leaf, but Ca translocation from the basal to the apical area was detected in fruit. Management affected the concentrations of leaf K and Mg and the fruit N, P and Ca. The agronomic efficiency of the macronutrients in the organic crops was superior to that in the conventional crops. The Ca and Mg and the N/Ca and Ca/(K+Mg) ratios were closely related to color, firmness, TSS, and ST content.

Ion-Selective Membrane-Coated Graphene-Hexagonal Boron Nitride Heterostructures for Field-Effect Ion Sensing.

An intrinsic ion sensitivity exceeding the Nernst–Boltzmann limit and an sp2-hybridized carbon structure make graphene a promising channel material for realizing ion-sensitive field-effect transistors with a stable solid–liquid interface under biased conditions in buffered salt solutions. Here, we examine the performance of graphene field-effect transistors coated with ion-selective membranes as a tool to selectively detect changes in concentrations of Ca2+, K+, and Na+ in individual salt solutions as well as in buffered Locke’s solution. Both the shift in the Dirac point and transconductance could be measured as a function of ion concentration with repeatability exceeding 99.5% and reproducibility exceeding 98% over 60 days. However, an enhancement of selectivity, by about an order magnitude or more, was observed using transconductance as the indicator when compared to Dirac voltage, which is the only factor reported to date. Fabricating a hexagonal boron nitride multilayer between graphene and oxide further increased the ion sensitivity and selectivity of transconductance. These findings incite investigating ion sensitivity of transconductance in alternative architectures as well as urge the exploration of graphene transistor arrays for biomedical applications.

Effect of High Volume Hemodiafiltration on Secondary Hyperparathyroidism Among Hemodialysis Patients

<i>Background: </i>Despite increasing knowledge of the uraemic syndrome, both morbidity and mortality remain unacceptably high in patients with chronic kidney disease. <i>Aim of the work: </i>investigate the differences between conventional hemodialysis and hemodiafiltration in the context of chronic kidney disease metabolic bone disease findings serum calcium (sCa), phosphate (sPO4) and intact parathyroid hormone (PTHint) concentrations. <i>Patients and methods: </i>This prospective cross over study was approved by Almaadi hospital committee and included 95 patients with CKD5 on regular hemodialysis for at least 6 months. Patients were divided into two groups: Group A: 60 patients scheduled 6 months conventional high flux (hf-HD) (Period1) followed by 6 months of post-dilutional–HDF (Period2). Group B: (controls) included 35 patients were kept on conventional hf-HD for 12 months. (Period3) for 1^st 6 months and (Period4) for 2^nd 6 months. The main variables evaluated at the start as well as at the end of each period were sCa, sPO4 and PTHint. <i>Results: </i>There was highly significant statistical decrease in Phosphorus level in period2 compared to other groups after 2^nd to 6^th month and average of overall (p<0.001). A significant statistical decrease was found in Parathormone level and CRP in period2 compared to other groups after 1 month to 6^th month and average of overall (p<0.05). There was significant statistical decrease in Albumin level in period2 compared to other groups after 2^nd to 6^th month and average of overall (p<0.05). There was a significant statistical increase in kt/v in period2 compared to other groups after 1^st to 6^th month and average of overall (p<0.05). <i>Conclusion: </i>The switch over from conventional Hf-HD to Ol-HDF results in a significant reduction of both PO4 and PTH concentrations, no significant changes in Ca concentrations.

Prenatal exposure to barium and the occurrence of neural tube defects in offspring

Neural tube defects (NTDs) have a complex etiology. Few studies have assessed alkaline earth metals exposures and occurrence of NTDs. We examined the association between prenatal exposure to magnesium (Mg), calcium (Ca), strontium (Sr) and barium (Ba) and risk for NTDs in a case-control study, and assessed the teratogenic effects of Ba on mice. Placentas were collected from 408 women with NTD-affected pregnancies and 593 women who delivered healthy infants, and concentrations of these metals were determined as prenatal exposure markers. The single effect of individual exposure and joint effect of coexposure to these metals were evaluated with logistic regression and Bayesian kernel machine regression (BKMR), respectively. Barium chloride (BaCl2) was intragastrically administered to pregnant ICR mice and fetal mice were examined for NTDs. Median concentrations of Mg and Ba were higher in NTD cases than in controls (Pall < 0.001). In logistic regression, higher levels of Ba were associated with 1.6-fold increased risk for NTDs (95% confidence interval: 1.06–2.43). In BKMR, the joint effect of the four-metal mixture on NTD risk increased steadily with the levels of the mixture. A change in Ba concentration from the 25th to 75th percentile displayed a risk effect when the other three metals were fixed at the 25th, 50th or 75th percentile, while such a change in Ca concentration showed a protective effect when the other metals were held at the 25th or 50th percentile. No interactions among metals were found. In the mouse experiment, dams treated with 200 mg/kg BaCl2 showed 16.8% of NTDs in fetal mice, compared to 2.6% in the untreated control group (P < 0.01). Taken together, higher mixture levels of the four alkaline earth metals were associated with increased risk for NTDs, with Ba being the major contributor for the joint effect. Intragastric administration of Ba can induce NTDs in mice.

What Can We Learn From X‐Ray Fluorescence Core Scanning Data? A Paleomonsoon Case Study

AbstractX‐ray fluorescence (XRF) core scanning of marine and lake sediments has been extensively used to study changes in past environmental and climatic processes over a range of timescales. The interpretation of XRF‐derived element ratios in paleoclimatic and paleoceanographic studies primarily considers differences in the relative abundances of particular elements. Here we present new XRF core scanning data from two long sediment cores in the Andaman Sea in the northern Indian Ocean and show that sea level related processes influence terrigenous inputs based proxies such as Ti/Ca, Fe/Ca, and elemental concentrations of the transition metals (e.g., Mn). Zr/Rb ratios are mainly a function of changes in median grain size of lithogenic particles and often covary with changes in Ca concentrations that reflect changes in biogenic calcium carbonate production. This suggests that a common process (i.e., sea level) influences both records. The interpretation of lighter element data (e.g., Si and Al) based on low XRF counts is complicated as variations in mean grain size and water content result in systematic artifacts and signal intensities not related to the Al or Si content of the sediments. This highlights the need for calibration of XRF core scanning data based on discrete sample analyses and careful examination of sediment properties such as porosity/water content for reliably disentangling environmental signals from other physical properties. In the case of the Andaman Sea, reliable extraction of a monsoon signal requires accounting for the sea level influence on the XRF data.

Effect of high volume hemodiafiltration on secondary hyperparathyroidism among hemodialysis patients

Abstract Background: Despite increasing knowledge of the uraemic syndrome,both morbidity and mortality remain unacceptably high in patients with chronic kidney disease. Study investigates the differences between conventional hemodialysis and hemodiafiltration in the context of chronic kidney disease metabolic bone disease findings, serum calcium (sCa), phosphate (sPO4) and intact parathyroid hormone (PTHint) concentrations. Patients and methods: This prospective cross over study was approved by Almaadi hospital committee and included 95patients with CKD5 on regular hemodialysis for at least 6months.Patients were divided into two groups:Group A:60patients scheduled 6months conventional high flux(hf-HD)(Period1) followed by 6months of post-dilutional –HDF (Period2). Group B:(controls)included 35patients were kept on conventional hf-HD for12months.(Period3)for 1st 6months and(Period4) for 2nd 6months.The main variables evaluated at the start as well as at the end of each period were sCa, sPO4 and PTH int. Results: There was highly significant statistical decrease in Phosphorus level in period2 compared to other groups after 2nd to 6th month and average of overall (p<0.001).A significant statistical decrease was found in Parathormone level and CRP in period2 compared to other groups after 1month to 6th month and average of overall (p<0.05).There was significant statistical decrease in Albumin level in period2 compared to other groups after 2nd to 6th month and average of overall (p<0.05).There was a significant statistical increase in kt/v in period2 compared to other groups after 1st to 6th month and average of overall (p<0.05). Conclusion: The switch over from conventional Hf-HD to Ol-HDF results in a significant reduction of both PO4 and PTH concentrations, no significant changes in Ca concentrations.

Световая адаптация палочек сетчатки, адаптационная память и последовательные образы

The GPCR signaling cascade in the retinal photoreceptor cells, rods and cones, provides high signal amplification and allows rods to respond reliably to single photons. At the same time, rods remain operational under light fluxes up to 105 photons per second, which is supported by a highly efficient system of light adaptation. Light adaptation is based on negative feedback chains, mainly through changes in the intracellular concentration of Ca2+ ions. There are three reliably identified loops of calcium regulation – the acceleration of quenching of photoactivated rhodopsin, the acceleration of cGMP synthesis by guanylate cyclase, and an increase of cGMP-controlled ion channels’ affinity to the nucleotide. However, it is known that there are additional one or two highly effective adaptation mechanisms, one of which regulates the lifetime of activated phosphodiesterase; for the second one, the target of regulation is unknown. The messengers of these regulations also remain unknown. While studying these mechanisms, we discovered a new phenomenon that was not noticed in previous works. We found that the restoration of rod’s dark current after turning off the non-saturating adapting light can take 20-30 s. Moreover, after the membrane current formally returns to the dark level, the sensitivity of the cell to testing stimuli remains reduced for one to two minutes. We called this phenomenon “adaptation memory”. Adaptation memory resembles the phenomenology of the afterimages. The gradual return of the membrane current to the dark level could correspond to the fading of positive afterimage. Long-term decrease in the sensitivity of photoreceptors to an additional stimulation can create a negative afterimage. As far as we know, this is the first experimental physiological demonstration of the possibility of afterimages generation already at the level of single photoreceptors.

Low salinity water flooding in carbonate reservoirs – dissolution effect

One of the most significant research subjects in the industry of oil is the low salinity water injection techniques (LSWI). This is because there are possible benefits of raising recovery in oil as opposed to the conventional injection of seawater. Recent research has been done to find out the causes of less salinity with the injection of water in carbonated rocks presented significant findings. The primary mechanisms that are thought to lower salinity water injection are carbonate rocks dissolution, fines migration and alteration of wettability to more water wet. However, many researchers have elected to oppose the mechanism of dissolution and instead attributed high recovery of oil to be the primary wettability modification mechanism. Additionally, previous researchers provided no evidence characterizing about the rock and fluids produced in a detailed manner. This research work provides a detailed description of the underlying mechanisms, the core flood laboratory and the spontaneous imbibition in carbonate rocks. In the experiment, we carried out a series of steps using a limestone core with low permeability. This core was obtained from a nearby oilfield in Iraq and used it to study how dissolution and fines migration mechanisms take place. Moreover, in the process of carrying out the experiment and before its starting, SEM imaging analysis was used. In this case, as we carried out the experiment, we had to inject two-phase flow of sea water (SW), de-ionized water (DW) as well as soltrol-130. This was done in a sequential manner at 50 °C as well as 0.02 ml per minute. As the experiment progressed, the concentration of ions and pH value of the extracted water were measured in a continuous manner. The results obtained indicate that the rate of change in concentration of Ca2+ ions is directly proportional to the effluent pH value. By just balancing the mass, we were able to easily see the rate at which limestone dissolved as the experiment progressed. The maximum increase in pH was registered when fresh water was injected (pH=9.2). An increase in pH value can have a positive effect on altering wettability in that it can increase the alkalinity of flood water. To notice fines migration, the Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscopy (EDS) are used to scan the images of the inlet and outlet of the core plugs after completion the experiment. This method can indicate that dissolution can induce fines dislodgement for the surface of the rock. The two mechanisms of fine migration and carbonate rock dissolution can significantly increase recovery of oil and at the same time inject water low in salinity.

Calcium dynamics of reproductive apple buds during the dormant season in the Western Cape, South Africa

Calcium (Ca) deficiency in apples results in unwanted physical disorders in mature fruit that reduce fruit value. Ca deficiency associated with bitter pit is already prevalent early in the season, as it is initiated a few weeks after full bloom. Information regarding Ca concentration in reproductive buds or bud tissues is lacking, thus we investigated the Ca concentration in reproductive buds of the bitter pit susceptible ‘Braeburn’ and non-susceptible ‘Cripps Pink’ apple cultivars during the dormant season. Wavelength-dispersive x-ray spectroscopy (WD SEM) was used to quantify total Ca concentration of parenchyma and vascular tissues, from June to September, for two seasons (2012 and 2014). Results showed a changing trend in Ca concentration from June to September for total Ca concentration and between cultivars. Total Ca concentration was the highest in ‘Cripps Pink’ during the whole period and related to the non-susceptibly to Ca related disorders. Ca concentration in ‘Cripps Pink’ declined towards September in contrast with the increasing trend of ‘Braeburn’. This may indicate that the total Ca concentration of the buds, and not the change of Ca concentration in buds during winter, is associated with a higher Ca status of fruit on non-susceptible cultivars. The actual Ca concentration of ‘Cripps Pink’ at the end of August was still higher than that of ‘Braeburn’. Results may be explained partly by the time of primary xylem formation in the bud, which happens earlier in ‘Cripps Pink’, as well as the associated increase in Ca translocation, indicating the role of generic differences between cultivars, contributing towards final changes in the inherent Ca concentration at the beginning of the dormant season.

Coarse-grained simulation reveals key features of HIV-1 capsid self-assembly.

The maturation of HIV-1 viral particles is essential for viral infectivity. During maturation, many copies of the capsid protein (CA) self-assemble into a capsid shell to enclose the viral RNA. The mechanistic details of the initiation and early stages of capsid assembly remain to be delineated. We present coarse-grained simulations of capsid assembly under various conditions, considering not only capsid lattice self-assembly but also the potential disassembly of capsid upon delivery to the cytoplasm of a target cell. The effects of CA concentration, molecular crowding, and the conformational variability of CA are described, with results indicating that capsid nucleation and growth is a multi-stage process requiring well-defined metastable intermediates. Generation of the mature capsid lattice is sensitive to local conditions, with relatively subtle changes in CA concentration and molecular crowding influencing self-assembly and the ensemble of structural morphologies.

Magnetization and Critical Current of Calcium-doped YBa2Cu3O7−x Composite Films

The results of the study of magnetization of Y1−xCaxBa2Cu3O7−δ HTS films deposited on the metallic substrate are presented. The magnetization measurements were carried out in a wide temperature range 4–77 K and magnetic fields up to 14 T. Based on critical state model, the analysis of the influence of calcium concentration on the critical current was performed. It was found that the change in Ca concentration causes the decrease in value of critical current density jc. The increase in temperature leads to enhancement of the observed effect. At T = 4.2 K and in the magnetic fields higher than 8 T, the jc reduction was found to be insignificant. This fact may indicate the possibility of jc growth in strong magnetic fields due to increase in carrier concentration caused by replacing Y3+ by Ca2+.

Abstract 2914: Gold magneto nanoparticles induced apoptosis in liver cancer cells through changes of Ca channel pump detected by LIBS Technique and RT-PCR array

Abstract Laser-induced breakdown spectroscopy technique (LIBS) was used in thesis study to address the effect of gold magneto nanoparticles on the liver cancer cells (HepG2) by examining the variation in genotoxicity and cytotoxicity. HepG2 cell line was cultured at 105 cells/ml and expanded, after which, they were incubated with gold magneto nanoparticles at concentrations 10, 25, 50 μg/ml respectively for 12 hours. The effect of these nanoparticles in cell apoptosis as well as in autophagy was evaluated by acridine orange staining and Annexin V/propidium iodide double staining as well as apoptosis specific PCR array assay for evaluation of apoptosis in the treated cells. At a concentration of nanocomposite 10, 25, 50 μg/ml, cells showed increase in the apoptosis figure from 11.25% ± 3.1% to 28% ± 2.04%, 39% ± 3.6%, 60% ± 4.3% respectively. Apoptosis specific PCR array also, showed very high expression of TNF, BIRC3 and NFKB1 with increasing in the fold regulation ratio of 155.03,158.03 and 149.2- fold respectively. On the other hand, extra investigation of these treated cells by LIBS shows an increasing in the iron oxide nanoparticles concentration as well as calcium concentration. This increase in the calcium content in the treated cells may play an important role in the program cell apoptosis which was prove in our study by both Flow cytometry as well as by profile apoptosis PCR array. Finally, our data showed the possibility of the using LIBS as inductor of cells apoptosis by measurement Ca concentration changes in liver cancer cells (HepG2 cells). Keywords: Apaptosis, LIBS; HepG2 cell; Genotoxicity Citation Format: Ola Ahmed, Hisham Imam, Abdel-Rahman N. Zekri. Gold magneto nanoparticles induced apoptosis in liver cancer cells through changes of Ca channel pump detected by LIBS Technique and RT-PCR array. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2914. doi:10.1158/1538-7445.AM2015-2914

Wood Decay Fungi Restore Essential Calcium to Acidic Soils in Northern New England

The depletion of root-available calcium in northern forests soils exposed to decades of increased acid deposition adversely affects forest health and productivity. Laboratory studies indicated the potential of wood-decay fungi to restore lost calcium to the rooting zone of trees. This study reports changes in concentrations of Ca, Mg, and K during decay of sapwood of spruce, maple, hemlock, and birch at two locations in northern New England, USA. Concentrations of exchangeable Ca, Mg, and Al in decayed wood residues after 10 and 12 years of ground contact were also compared. Significant loss of mass indicated by decreasing wood density occurred after two to eight years in conifers and after only two years in hardwoods. A significant gain in wood K was observed at two years, but the gain was not sustained. A significant gain in Ca concentration occurred by six years and that gain was sustained for 12 years. Concentrations of Mg varied. No significant difference in exchangeable Ca concentration was observed between decayed wood residue of spruce and maple and the forest floor. However, decayed wood residue had a much lower molar Al/Ca ratio, a conditional characteristic of sites with high root-available Ca.

Mechanosensitive ion channel MscL controls ionic fluxes during cold and heat stress in Synechocystis.

Calcium plays an essential role in a variety of stress responses of eukaryotic cells; however, its function in prokaryotes is obscure. Bacterial ion channels that transport Ca(2+) are barely known. We investigated temperature-induced changes in intracellular concentration of Ca(2+), Na(+) and K(+) in the cyanobacterium Synechocystis sp. strain PCC 6803 and its mutant that is defective in mechanosensitive ion channel MscL. Concentration of cations rapidly and transiently increased in wild-type cells in response to cold and heat treatments. These changes in ionic concentrations correlated with the changes in cytoplasmic volume that transiently decreased in response to temperature treatments. However, no increase in ionic concentrations was observed in the MscL-mutant cells. It implies that MscL functions as a non-specific ion channel, and it participates in regulation of cell volume under temperature-stress conditions.