Phosphorus. From elemental light to chemical element.
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Chemistry↗
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[The relationship of cationic toxicity to the density of the corresponding chemical elements].
The density of 46 chemical elements and LD50 of chloride cations were compared. There was a significant inverse relationship of LD50 to the density of 34 chemical elements. Quantitative ratios between these values for the elements studied were calculated.
Animals↗
[Dynamics of contents of chemical elements in fetal liver, and its physiological and nutritional significance].
The dynamics of contents of chemical elements in fetal liver, and its physiological and nutritional significance are studied. Twenty-one chemical elements in livers of fetus from induced abortion aged four to ten months are measured and are compared with those in adult. The relativity between the monthly average contents of twenty-one elements and fetus month age are analyzed and assorted. The results show that the contents of chemical elements of fetus liver are not well distributed and are not stable during the stage of fetus growth, and even change following the fetus's age. The changing patterns of contents of chemical elements of fetus liver can be divided into three types: a marked positive relativity of some chemical element contents with the increase in fetus age, marked negative relativity with the increase of fetus age, and indefinite relativity with the increase of fetus age. In the time period of embryo development to fetus to newborn infant, the content of some elements that has marked positive relativity with the increase of fetus age varies from low to high, indicating an increase of their contents in liver of fetus while supplying the need of fetus growth. The content of elements that have marked negative relativity with the increase of fetus age varies also from low to high and rapidly decreases in per unit tissue, resulting in an increase of the sensitivity to deficiency of these elements. The contents of elements that have indistinctive relativity with the increase of fetus age may not bring about any impact to fetus and newborn infant from the view of physiology and nutrition.
Calcium↗
Contents of chemical elements in stomach during prenatal development: different age-dependent dynamical changes and their significance.
AIM: To observe dynamic of different chemical elements in stomach tissue during fetal development. METHODS: To determine contents of the 21 chemical elements in each stomach samples from fetus aging four to ten months. The content values were compared to those from adult tissue samples, and the values for each month group were also analyzed for dynamic changes. RESULTS: Three representations were found regarding the relationship between contents of the elements and ages of the fetus, including the positive correlative (K), reversely correlative (Na, Ca, P, Al, Cu, Zn, Fe, Mn, Cr, Sr, Li, Cd, Ba, Se ) and irrelevant groups (Mg, Co, Ni, V, Pb, Ti). CONCLUSION: The chemical elements' contents in stomach tissues were found to change dynamically with the stomach weights. The age-dependent representations for different chemical elements during the prenatal development may be of some significance for assessing development of fetal stomach and some chemical elements. The data may be helpful for the nutritional balance of fetus and mothers during prenatal development and even the perinatal stages.
Adult↗
[Content of chemical elements in the liquid manure of swine at a treatment plant using biological purification].
An atom absorption spectrophotometer was used to study 13 chemical elements in samples taken at the entrance of the purification station, at the mechanical step exit, at the biostep exist, and at the laguna exit as well as following treatment of the solid fraction in open surface purification and drying plots. It was found that part of the biogenic chemical elements remained in the liquid fraction after purification and were hazardous in terms of eutrophication of the water receptacle. A technology was worked out to treat the solid fraction, however, it did not provide for preserving the biogenic chemical elements. This lowered the qualities of the fraction in enriching the soil.
Animals↗
[The chemical element content of mixed unstimulated saliva in periodontal diseases].
The levels of 21 chemical elements (N, Na, Mg, P, Cl, K, Ca, Sr, Cr, Mn, Fe, Co, Zn, Se, Br, Rb, Sc, Ag, Sb, Hg) were measured in mixed unstimulated saliva of 50 patients with periodontal diseases (29 women and 21 men) aged 20 to 49 without concomitant diseases, five of these with gingivitis and the rest with generalized periodontitis of medium severity (27 cases) and grave (n = 18). A control group consisted of 52 healthy subjects with intact periodontium and teeth. A complex of instrumental methods has been developed and used in this study including neutron activation analysis (NAA) in two modifications and roentgen-fluorescent analysis. Changes in salivary levels of chemical elements were detected in the patients, these changes augmenting with severity of periodontal tissue involvement. In grave condition the concentrations of the major electrolytes were increased by 2.3 to 6.6 times on an average, of nitrogen twofold, of scandium, manganese, and chromium by 6.8-8.8 times, and of iron, cobalt, copper, selenium, bromine, silver, and mercury by 1.6-1.9 times; zinc level in mixed salivary protein reduced as the disease augmented in severity and in a grave form was only 62% of its normal content (p < 0.01). Salivary oversaturation with ions including Ca2+ which are conductive to salivary glycoprotein sedimentation and eventually to formation of a nutrient medium for pathogenic bacteria and zinc deficit indirectly indicating a reduced level of immunity status of the body are additional factors responsible for increased rate of dental deposit formation in periodontal diseases.
Adult↗
[Experimental study on induction of lung cancer in hamster by fifteen chemical elements in the industrial dust from Yunnan Tin and other mines].
To exclude the carcinogenicity of trace radioactive elements in the mine powder and flue dust and clarify those inorganic chemical elements related to carcinogenesis of lung cancer, 15 non-radioactive inorganic chemical elements (CM1) responsible for mutagenesis, tumorigenesis and promotion of cancer from mine powder and flue dust were mixed for Ames test and carcinoma-inducing-experiment in animals. The results were as follows: 1. Ames test of CM1 showed positivity. 2. Lung cancer-inducing-experiment of CM1 in the hamster was successful with an incidence of 8.8% whereas in the control group, no lung cancer developed which showed that CM1 was related to the development of lung cancer. 3. Hyperplastic cells under light microscope showed Type II alveolar cells and Clara cells under electron microscope. It is possible that hyperplastic, precancerous and malignant cells in the lung are derived from these two kinds of cells. One case of multiple microcarcinoma was found in this experiment.
Animals↗
Study of chemical element behavior in health and disease by means of neutron activation analysis and multivariate statistics.
An attempt was undertaken to estimate the contribution of individual chemical elements to the rise of arterial hypertension. Instrumental neutron activation analysis was used to determine the concentrations of 23 chemical elements in hair of patients and healthy subjects. Mean concentrations as well as relationships between elements in both groups were calculated and compared. Discriminant function was obtained, which allows the division of patients and healthy subjects into two groups.
Adult↗
[Optimal isotope composition of biogenic chemical elements on board of manned spacecrafts].
Isotope composition of biogenic chemical elements (BCE) is discussed. A hypothesis is offered that biochemical and biomedical processes must be influenced as by the isotope composition of hydrogen and oxygen, so by the composition of stable isotopes of all the BCE constituting plants, animals, and humans. Biochemical, toxicological and other biomedical analyses should be performed to determine the best BCE isotope composition. These must be followed by development of methods, technologies, and life support systems to form and maintain the best isotope composition inside spacecraft habitable modules.
Humans↗
[Change in the content of chemical elements in epitheliocytes of the prickle cell layer of granulating skin wounds exposed to ultraviolet rays and ultraviolet laser therapy].
Spinous layer of human epidermis was studied in control group (2 human subjects) and in 16 patients with thermic lesions prior to and following ultraviolet laser therapy (UVLT) of ultraviolet irradiation (UVI). Skin biopsy was performed in each patient on undamaged regions (individual control). Chemical elements (Ca, K, Cl, Mg, Na and Al) content prior to and following treatment was compared. Patients with equal stage (IIIB) and localisation of lesion were selected. Bioptates were obtained for diagnostic purposes. UVLT was established to prompt normalization of the content of chemical elements named in epitheliocytes of human epidermis in IIIB lesions whereas UVI does not cause this effect at the same conditions. It is proposed that this difference is dependent on the origin of appropriate irradiations.
Adult↗
[Occurrence of harmful chemical elements (Hg, Cd, Pb) in pig stalls].
The presence of harmful chemical elements (Hg, Cd, Pb) in the stable environment for fattened pigs was compared in Hodonin district in the years 1984 and 1994. These data were recorded for the year 1994 in comparison with 1984: 1, mercury content in feed mixtures for pigs decreased 102 times (0.510 and/or 0.005 mg/kg), cadmium content 8 times (0.400 and/or 0.048 mg/kg) and lead content 6 times (2,680 and/or 0.420 mg/kg); 2. mercury content in stable dust deposition decreased 27 times (0.480 and/or 0.018 mg/kg) and cadmium content 6 times (1.370 and/or 0.248 mg/kg), but lead content slightly increased (5.980 and/or 8.569 mg/kg); 3. mercury content in the bristles dropped 20 times (0.440 and/or 0.022 mg/kg), cadmium content 5 times (0.080 and/or 0.015 mg/kg) and lead content 10 times (1.690 and/or 0.195 mg/kg). In addition, the presence of Hg, Cd and Pb in pig manure and road dust was investigated. Road dust exhibited an increased lead concentration (22.800 mg/kg), so it is not possible to exclude lead penetration from the stable surroundings to the internal environment of the stable. After application to arable land, pig manure can be a vector of some amounts of heavy metals (Hg 0.003; Cd 0.024; Pb 0.518 mg/kg dry matter). It is a positive result that there has been a significant decrease in mercury and cadmium contents in the stable environment for fattened pigs in the last decade. This fact reduces the health risk not only for pigs but also for their tenders.
Animal Feed↗
A modern periodic chart of chemical elements.
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Chemical Phenomena↗
[Elemental chemical composition of Scolelepis fuliginosa (Annelida, Polychaeta): effect of growth conditions].
The elemental chemical composition of Scolelepis fuliginosa was comparatively with specimens reared in laboratory and from a natural population. The carbon-nitrogen ratio variations show a certain homogeneity of composition in juveniles and young sexed and a sexual dimorphism in adults. C/N ratio of the laboratory specimens is not significantly different from that of the ones from natural surroundings. But, when these are kept several weeks in captivity, this ratio considerably decreases.
Age Factors↗
[The chemical element content of mixed unstimulated saliva from a healthy subject].
The levels of 21 chemical elements (N, Na, Mg, P, Cl, K, Ca, Sc, Cr, Mn, Fe, Co, Cu, Zn, Se, Br, Rb, Sr, Ag, Sb, Hg) were measured in 52 normal subjects aged 18 to 35 years with the use of a complex of instrumental methods including the neutron activation and x-ray fluorescence analysis. Effects of day time, season, sex and age on salivary composition were examined. The measured concentrations of chemicals in mixed nonstimulated saliva were different in each individual; some of them were liable to change only in the course of 24 hrs, therefore the time for saliva collection had to be strictly defined: 10-12 a.m. were found the optimal hours for saliva collection. Neither sex, nor age, nor season influenced the concentrations of the examined 21 chemicals, except Hg whose concentration grows with age.
Adolescent↗
Periodic systems of molecules as elements of Shchukarev's "supermatrix", i.e. the chemical element periodic system.
Generations of Soviet scientists contributed invaluable insights into molecular classification. Unfortunately, this research is little appreciated in much of the world. Among these workers S. A. Shchukarev was of great importance. His and his followers' legacy includes a host of graphical displays showing enthalpies of formation of gaseous molecules from free atoms DeltaH(a) and standard enthalpies of formation of substances plotted on the atomic number of the central elements, on their oxidation states, their internuclear separations, and other variables for a wide range of molecules. These graphs serve as databases, from which data can be extracted, to moderate precision, visually. We discuss graphs for one very limited set, or "pleiade" (gas-phase oxides of nitrogen), and for three much broader sets, or subsystems (gas-phase fluorides of all main subgroup atoms and oxides of transition-metal atoms in gas-phase and in STP conditions). When dissolved in water, molecules lose their identities but periodicity is echoed in the acids and aquocations that are formed. We show, as an example in tabular form, that redox potentials of high-oxygen acids containing S, Se, and Te change concomitantly with DeltaH(a ) and DeltaH(f) of their hexafluorides. We present graphical evidence that three properties for cations of groups 1-3 (in the short version of the periodic chart) behave similarly and share the periodicity of the elements. One of the properties is related to the ionization potential, which is shown in a tabular example to vary concomitantly with energy of hydration. It was the ultimate goal of S. A. Shchukarev that the transformation of any one graphical database into any other, having different molecules under different conditions, would be made mathematically.
Journal Article↗
Concentrations and leachability of chemical elements in estuarine sulfur-rich sediments, W. Finland.
Concentrations, distributions and mobility of chemical elements were investigated in reduced sulfur-rich estuarine sediments located in western Finland. The main objective was to determine the possible extent of metal leaching when dredged masses of these sulfur-rich sediments are dumped on the land and thus exposed to air. When dredged, the reduced sulfur in the sediments oxidises resulting in a lowering of pH, which in turn is expected to leach metals. The study area is an artificial lake claimed from the Botnian sea in 1962. In this lake, several mass-kills of fish have occurred, believed partly to be due to dredging. Two sediment samples (0-50 and 50-100 cm) were taken from 39 sampling points in the lake. These samples were leached in aqua regia (2:2:2 HNO3/HCl/H2O1) and analysed for Fe, Al, Mg, Ca, K, P, Na, Mn, Zn, Ba, V, Sr, Cr, Ni, Cu, Co, As, Pb, B, Mo and Cd with ICP-AES. Sulfur and organic carbon were analysed with Leco. In a controlled laboratory experiment, the sediments were allowed to oxidise for 1 year while moisturised with deionised water every month. The pH and conductivity were determined in the beginning of the experiment (reduced state) and in the end (oxidised state). In the supernatants in the oxidised states the amount of leached metals (Na, Al, Mn, Zn, Sr, Co, Ni, Cu, Cd, Cr, Pb, U, Li, Rb and As) were determined with ICP-MS. The sediments were found to contain low levels of toxic metals but, as expected, high concentrations of sulfur. In the experiment, pH was lowered (down to 3.0) and the conductivity increased in all samples due to oxidation and release of metal ions. The extent of leaching varied between 0.03% for As and 12.3% for Na. Critical pH values, at which high amounts of metals begin to leach, were obtained graphically. These values varied between 4.8 (Ni) and 3.3 (Cr). Not all elements were controlled by pH, e.g. Mn correlated well with its aqua regia leachable concentration. In a planned dredging operation in the area some 23,300 t (10,500 m3) (dry wt.) of sediments will be dredged. The amounts of metals likely to be leached, according to the results from this study, are as follows (kg): Al (1710), Mn (1230), Zn (59), Sr (39), Co (13), Ni (12), Cu (2) and less than 1 kg of Cd-Cr-As-Pb.
Journal Article↗
[The distribution of the content of chemical elements and metals in the brain tissue in bacterial meningoencephalitis].
The quantitative distribution of chemical elements and metals was assessed in the brain of 10 autopsy cases. The patients died of bacterial meningoencephalitis. It was found that the most "water-soaked" regions of the brain showed an increased accumulation of the concentration of metals correlatingly bound with water. The state of cerebral microvessels play a main role in regulation of the mineral metabolism.
Brain↗
[Toxicity of chemical elements].
A survey is presented of the most important facets of toxicity due to chemical elements as well as of the mechanisms through which it may be triggered. In particular, a detailed discussion is made on the characteristics shown by arsenic, cadmium, chromium, lead, mercury, barium and beryllium, with specific reference to the influence exerted by physiological, environmental and life-style factors.
Adult↗