SIMS Investigation of the Distribution of K+, Na+, Mg2+ and Ca2+ Cations in Birch Pollen

Two microanalytical techniques were used to investigate the inorganic cation content and distributions in birch (Betula verrucosa Ehrh.) pollen. With intact pollen grains. X-ray microanalysis (EDX) could only give a mean ionic composition. Secondary Ion Microscopy and Spectrometry (SIMS) appeared to be a more suitable technique to image ion distributions in the different pollen structures. This was carried out with samples prepared using a new vapour phase technique designed to improve ion retention. Transmission electron microscopy (TEM)showed good structural preservation of the samples. Monovalent ion (K⁺, Na⁺) distribution showed features different from those of the divalent cations (Ca²⁺, Mg²⁺). In the vegetative cell, the alkaline cations were mainly distributed in the most internal part of the cytoplasm and they were probably associated with starch grains or concentrated in dry vacuoles. Calcium distribution correlated well with the areas in the cytoplasm of the vegetative cell containing a dense network of mitochondria and endoplasmic reticulum. Within the pollen grain, the sperm cell appeared to contain the most calcium. Calcium was also abundant in the sporoderm. These results reveal the potential of SIMS for pollen studies that include germination, the monitoring of air pollutants and the allergens-ion interactions.     

Determination of the elemental composition of mature wheat grain using a modified secondary ion mass spectrometer (SIMS)

An imaging secondary ion mass spectrometry system has been developed that allows the distribution of elements or ions to be superimposed on an image of the plant cell or tissue generated by ion-induced secondary electrons. This system has been evaluated by analysing the aleurone and sub-aleurone cells of mature wheat grain, showing high spatial resolution (100-200 nm) images of O-, PO(2)-, Mg+, Ca+, Na+ and K+ within the phytate granules of the aleurone, with CN- being diagnostic for proteins and C(2)- being diagnostic for starch in the starchy endosperm cells. This system should provide improved localization of elements in a range of other plant systems.     

盐胁迫下杨树根际系统盐分离子分布特性

在温室条件下,采用盆栽根箱培养的方法研究盐胁迫下I 69杨(PopulusdeltoidesBartr.cv.'Lux')和NL 1381杨〔PopulusdeltoidesBartr.cv.'Lux'×P.euramericana(Dode)GeninierCL'I 45 51'〕根际、非根际土壤盐分分布特征。盐处理浓度共设3个水平:CK(NaCl0g kg)、处理A(NaCl1g kg)和处理B(NaCl2g kg),采用完全随机设计。结果表明,2个杨树无性系根际水溶性K+亏缺,水溶性Na+、Ca2+和Mg2+富集。K+的亏缺率及Na+的富集率随NaCl处理浓度的增大而减小,Ca2+和Mg2+的富集率在非盐渍条件下最低,处理A达最高,处理B较处理A略有下降。在盐胁迫下,无性系NL 1381杨根际土壤Na+的浓度和电导率均低于无性系I 69杨,可以有效减轻盐分对根系的渗透胁迫,相对而言具有较强的抗盐性。     

Microbeam PIXE analysis of Na,K, Mg,and Ca in severely damaged cardiac tissue

The aim of the study was to measure with microbeam PIXE elements such as Na, K, Mg, and Ca in cardiac tissue after various treatments in vivo, which affect the cardiomyocyte integrity. It was assumed that local deviations from normal electrolyte levels indicate the degree of cardiac damage. The first step in this feasibility study was comparison of severely damaged cardiac tissues with controls. Severe cardiac damage was introduced by the so-called Ca paradox. Experiments were performed with isolated rat hearts, perfused retrogradely with an oxygenated crystalloid buffer. Results indicated that severe cardiac damage was accompanied with almost complete disappearance of the normal intracellular electrolyte composition as a result of the loss of membrane integrity. Identifications of smaller and more locally present ischemic damages on basis of altered electrolyte levels appeared to be feasible. However, the prerequisite was that the mobility of electrolytes be kept under control during tissue sampling and sample preparation, when physiological mechanisms stop to maintain gradients.     

SIMS determination of the distribution of the main mineral cations in the depth of the cuticle and the pecto-cellulosic wall of epidermal cells of flax stems: problems encountered with SIMS depth profiling

Depth profiles of C, Na, Mg, Al, K and Ca were performed in the cuticle and wall of epidermal cells of flax hypocotyls, with current densities ranging from 0.2 to 1 pA μm^?2. The crater bottoms were never flat, but exhibited fairly complex, filiform or alveolar structures. The profiles of K, Ca and Mg were reasonably parallel to one another. The Ca/Mg signal ratio was in the magnitude of 3.5 in the cuticle. The Na profile, except perhaps in the cuticle, did not parallel the K, Ca and Mg profiles, but rather paralleled the C profile. At the outset of the depth profiles, ie in the cuticle, the intensity of the Na signal, although fairly variable, was usually above that of K; then there was an abrupt decrease of the Na signal, possibly at the border of the cuticle and of the wall. The Al signal usually began to increase, thus revealing the occurrence of perforations through the epidermis sample, after 80 min sputtering at a current density of 1 pA μm^?2; the mean sputtering rate was thus estimated to be in the order of 1 μm h^?1.     

Microprobe analysis of Na,K, Cl,P, S,Ca, Mg and H2O in frozen-hydrated sections of anterior caeca of the locust, Schistocerca gregaria

Electron probe X-ray microanalysis of frozen-hydrated sections was carried out for sodium, potassium, chlorine, calcium, magnesium, sulphur, phosphorus and water concentrations in the lumen and epithelial cells of freshly-fed adult female desert locusts, and in blood of fed and starved locusts.Sodium and chloride were found to be at a much lower level in the lumen and cells than potassium, and at a much higher level in the blood. The luminal folds were plugged with a dense organic matrix, presumed to be polyanionic glycosaminoglycans, which appeared to restrict access of charged moieties of the absorptive sites. The data were consistent with a model of caecal fluid absorption in which a passive flux of potassium from lumen to blood, possibly assisted by an active absorption of chloride, drives fluid into the blood. Unlike the case of the vertebrate intestine, active absorption of sodium from the lumen would not contribute significantly to the fluid transport in vivo.     

Analysis of Metal Element Distributions in Rice (Oryza sativa L.) Seeds and Relocation during Germination Based on X-Ray Fluorescence Imaging of Zn,Fe, K,Ca, and Mn

Knowledge of mineral localization within rice grains is important for understanding the role of different elements in seed development, as well as for facilitating biofortification of seed micronutrients in order to enhance seeds’ values in human diets. In this study, the concentrations of minerals in whole rice grains, hulls, brown rice, bran and polished rice were quantified by inductively coupled plasma mass spectroscopy. The in vivo mineral distribution patterns in rice grains and shifts in those distribution patterns during progressive stages of germination were analyzed by synchrotron X-ray microfluorescence. The results showed that half of the total Zn, two thirds of the total Fe, and most of the total K, Ca and Mn were removed by the milling process if the hull and bran were thoroughly polished. Concentrations of all elements were high in the embryo regions even though the local distributions within the embryo varied between elements. Mobilization of the minerals from specific seed locations during germination was also element-specific. High mobilization of K and Ca from grains to growing roots and leaf primordia was observed; the flux of Zn to these expanding tissues was somewhat less than that of K and Ca; the mobilization of Mn or Fe was relatively low, at least during the first few days of germination.     

Effect of ATP,EDTA and EGTA on the simultaneous binding of Na,K, Mg and Ca by rat liver microsomes

In the presence of Na, K, Mg and Ca at physiological pH, complexing agents can affect cation binding by rat liver microsomes in a manner not always readily predictable simply from a knowledge of individual formation constants. Increasing concentrations (0 to 20 mM) of the strong nonbiological complexing agent, ethylenediaminetetraacetate (EDTA), produced a sharp decrease almost to zero in bound Ca, an increase to a high plateau in bound Na and K and an initial increase followed by a sharp decrease in bound Mg. Increasing concentrations of the Ca-preferring analogue of EDTA, ethylene bisglycol (β-aminoethylether) tetraacetate (EGTA), produced similar changes except that bound Mg increased and remained elevated, indicating that this agent complexes Mg very weakly at physiological pH. The biological complexing agent, adenosine triphosphate (ATP), caused a gradual rectilinear and parallel decrease in bound Mg and Ca and a concomitant and parellel increase in bound Na and K at about 4°C and pH 6.4. Results with EDTA and EGTA suggest, however, that under different conditions, enhancement by ATP of divalent cation binding may be possible. Reactions of this nature may be of significance in ATP stimulated divalent cation uptake by subcellular particles.     

钠、钾、钙和葡萄糖对白斑狗鱼精子活力的影响

观察了白斑狗鱼精子在0～679．6kPa NaCl、KCl、葡萄糖溶液和0～339．8kPa CaCl2溶液中的活动情况。在NaCl、KCl、葡萄糖溶液中,白斑狗鱼精子快速运动时间和寿命的变化规律基本一致,精子活动最适渗透压介于339．8～453．0kPa。K^ 有延长精子寿命的作用。外源性葡萄糖可被精子利用,增强精子活力．延长精子寿命。56．7kPa CaCl2对精子活动有抑制作用,并引起精子聚集,该效应随着Ca^2 浓度升高而增强。     

Studies on urine and tissues of rats,guineapigs and mice exposed to sulphur mustard using mass spectrometry

Urine and tissues (brain, liver, kidney, fat and triceps muscles) from rodents (rats, guinea pigs and albino mice) treated with sulphur mustard percutaneously were examined for the presence of sulphur mustard and/or metobolites using electron impact direct inlet and GC-mass spectrometry. Sulphur mustard and thiodiglycol sulphoxide were not detected in these samples even after application of massive doses. However, thiodiglycol was identified in urine only     

Ultrasensitive radioisotope,stable-isotope,and trace-element analysis in the biological sciences using tandem accelerator mass spectrometry

The new technique of tandem accelerator mass spectrometry (TAMS) has improved the sensitivity for measurement of several long-lived radioisotopes and certain stable isotopes by many orders of magnitude. Nuclear physics tandems and new small dedicated accelerators are now able to measure¹⁴C,¹⁰Be,²⁶Al,³²Si,³⁶Cl,⁴¹Ca, and¹²⁹I in natural materials. Sensitivities down to 10⁵ atoms per sample can be achieved in favorable cases. By accelerating ions to MeV energies, one can eliminate molecules and uniquely identify the atomic numbers below 20. Although most applications to date have been in the earth sciences, the opportunity now exists for important new applications in biology and toxicology. Trace elements can be measured at the parts per billion (10⁹) level using a secondary ion mass spectrometry (SIMS) ion source. Radioactive tracer measurements can be made for elements, such as aluminum, for which there are no isotopes with suitable half-lives for conventional decay counting methods. For¹⁴C, counting times become much shorter and dose levels can be reduced.     

Clastogenicity in vitro of the Na, K, Ca and Mg salts of saccharin; and of magnesium chloride; consideration of significance

The sodium, potassium, calcium and magnesium salts of saccharin, and magnesium chloride, have been shown to be clastogenic to Chinese hamster lung (CHL) fibroblasts in vitro, but only at elevated dose levels (8-16 mg/ml). Saccharin acid was inactive to the limits of its solubility (4 mg/ml). When the data are expressed in terms of ionic concentration, each salt showed a similar clastogenic potency. This suggests that ionic effects induced by these salts in the assay medium may be the critical determinant of the clastogenic effects seen, rather than that the saccharin moiety presents a genotoxic insult to the chromosomes of the cells. The metal-chelating agents EDTA and EGTA were non-clastogenic, but the disodium salt of EDTA showed weak activity prior to toxicity at 0.5 mg/ml. The absence of a clastogenic response for the salts of saccharin at dose levels lower than 4 mg/ml is discussed within the context of the threshold-dependent tumour-promoting activity of high dose levels of sodium saccharin to the bladder of male rats. The doubtful value of conducting in vitro clastogenicity studies at dose levels greater than 10(-2) M is discussed.     

Investigating the Effects of Chemical Gradients on Performance and Reliability within Perovskite Solar Cells with TOF‐SIMS

Time‐of‐flight secondary‐ion mass spectrometry (TOF‐SIMS), a powerful analytical technique sensitive to all components of perovskite solar cell (PSC) materials, can differentiate between the various organic species within a PSC absorber or a complete device stack. The ability to probe chemical gradients through the depth of a device (both organic and inorganic), with down to 100 nm lateral resolution, can lead to unique insights into the relationships between chemistry in the absorber bulk, at grain boundaries, and at interfaces as well as how they relate to changes in performance and/or stability. In this review, the technique is described; then, from the literature, several examples of how TOF‐SIMS have been used to provide unique insight into PSC absorbers and devices are covered. Finally, the common artifacts that can be introduced if the data are improperly collected, as well as methods to mitigate these artifacts are discussed.     

Blood Pressure and Levels of Fe, Ca, Mg, Zn, Cu, Na and K in the Hair of Young Bantu Men from Tanzania

Mineral imbalance in the body may significantly contribute to the development and course of hypertension. In this paper, blood pressure figures have been linked to the levels of Fe, Ca, Mg, Zn, Cu, Na and K in hair. The research sample was composed of young men (n?=?91) aged 13–21, from the town of Mafinga, Iringa District, Tanzania. The data collected included their age, tribal background and weekly diet. Based on body mass index, the participants were categorised into pre-defined subgroups. To examine how the minerals in question affect blood pressure, correlation analysis and multiple ridge regression analysis were performed. Analysis of ridge regression findings for the researched group (n?=?91) shows that the minerals under scrutiny account for systolic blood pressure variation in 13 % and in 15 % for diastolic blood pressure variation. After including two additional variables—calendar age and body mass index—in regression analysis, the ultimate coefficient of determination (R ²) changes for systolic blood pressure and remains the same for diastolic blood pressure (R ²?=?0.194 and R ²?=?0.156, respectively). Nutritional analysis shows that the students included in the study received insufficient calories per day (1,500–2,200 kcal). The group of students with abnormal blood pressure were not aware of their poor health. Research findings may result from progressive environmental changes and poor nutrition in terms of food quantity and quality, which had an impact on the subjects’ blood pressure. Hair analysis used to determine mineral content in the body may be an auxiliary tool in identifying the links between factors leading to the development of hypertension.     

Distribution of a cryptating agent in excreta and its influence on urinary elimination of Na, K, Mg, Ca and Zn in the rat.

After a single s.c. dose of 13, 16, 21, 24-hexaoxa-1, 10-diazabicyclo- (8, 8, 8)-hexacosane, A-(222), rats eliminate 42% of this cryptating agent via urine during the first 24h and about 34% via feces during the second 24h. Excretion seems to be complete within 72h. A-(222) impairs significantly the urinary excretion of sodium-potassium- and calcium-ions during the first 24h. The excretion of magnesium- and zinc-ions is not affected. The observed impairments cannot be interpreted as a chelation effect of A-(222) with these cations.