scholarly journals ORGANIC GEOCHEMISTRY OF HUMIC ACIDS FROM A NEOGENE LIGNITE SAMPLE, BULGARIA

2017 ◽  
Vol 43 (5) ◽  
pp. 2398
Author(s):  
M. Stefanova ◽  
S.P. Marinov

Humic substances naturally occur in Miocene/Pliocene-aged lignite at very high concentrations. Here biomarkers in the bitumen-free extract of humic acids from Thracian lignite, Bulgaria, are studied. Applying methods of organic geochemistry a broad range of compounds are isolated and characterised. Species are classified according to abundance, possible source input and diagenetic transformation. A feature of humic acids derived from Thracian coal is the extremely high content of 16α(H)Phyllocladane, ~60% of aliphatic fraction, or 1.6 wt.% of initial lignite. The high diterpenoids content, especially with abietane skeleton, proved the conifer contribution to the peat-forming helophytes, i.e. Cupressaceae s. str., Podocarpaceae, Araucariaceae, Taxodiaceae, Phyllocladus, Piceae. Tightly-trapped, linear long-chain fatty acids (FAs) are the main constituents of the acidic fraction of humic acids. Their distribution patterns indicate a dominant higher plant origin. The presence of αOH-FAs and hopanoid acids assumes bacterial activity in the plant material reworked. A hint for the input of plant biopolymers, i.e. cutin, suberin, is the relative high content of “even” carbon numbered ωΟΗFAs and α,ω-alkanedioic FAs. “Even” numbered short-chain ωΟΗFAs could originate from cutin-derived constituents of the needles of numerous species of gymnospermous families.

1986 ◽  
Vol 34 (2) ◽  
pp. 155 ◽  
Author(s):  
PJ Hocking

A study was made of mineral nutrient concentrations and distributions in leaves and fruits of 10 species of Grevillea from diverse localities in south-western Australia. Seeds of all species contained high concentrations of mineral nutrients, despite the nutrient-poor soils of their habitats. Leaves and the leathery follicles which contained the seeds typically had very low levels of nutrients. With few exceptions, the concentration and distribution patterns of a particular nutrient in fruits were similar in all the species studied. In these species, over 90% of the P content, and between 50 and 70% of the N, Zn and Cu contents of a fruit were located in seeds. Some species accumulated very high concentrations of a particular nutrient, e.g. Ca in seeds and leaves of G. leucopteris, K in seeds of G. tripartita and Fe in follicles of G. petrophiloides. Ratios of K : Ca concentrations were low (< 1) in seeds of G. candelabroides, G. petrophiloides, G. pinaster and especially G. polybotrya and G. leucopteris, which are characterized by high Ca concentrations in their seeds. In the Grevillea species studied, Na C1 and Fe accumulated in the leathery follicle but not in the seeds. A study of G. leucopteris from 18 localities throughout its ecological and distributional range showed that concentrations and distribution patterns for each nutrient in fruits were similar, irrespective of soil type. It is concluded from the results for G. leucopteris and the other species that there is conservative genetic regulation of seed mineral nutrition in the genus Grevillea.


1996 ◽  
Vol 8 (1) ◽  
pp. 15-22 ◽  
Author(s):  
S.J. De Mora ◽  
P.A. Lee ◽  
A. Grout ◽  
C. Schall ◽  
K.G. Heumann

The distribution of dimethylsulphide (DMS), together with the precursor dimethylsulphonio-propionate (DMSP) and the oxidation product dimethylsulphoxide (DMSO), was measured in melt waters on the McMurdo Ice Shelf in the immediate vicinity of Bratina Island. Conductivity in these sulphate dominated ponds was extremely variable, ranging from 0.106–52.3 mS cm−1. Similarly, chlorophyll a concentrations in the pond waters (1–150 μg 1−1) and mats (1.4–33 μg cm−2) differed considerably. The biomass was dominated by benthic felts of phototrophic cyanobacteria, which might act as a source of biogenic sulphur compounds in the ponds. The mean (and ranges) of concentrations of dissolved sulphur compounds (nmol 1−1) were: CS2 0.16 (<0.04–1.29); DMSPd 0.6 (<0.07–8.4); DMS 3.5 (<0.07–183); DMSO 27.9 (15.5–184.5). Very high concentrations of DMSO were ubiquitous in the ponds in the ice-cored moraine region of the ice shelf, with dissolved concentrations having been 1–2 orders of magnitude greater than those of DMS or DMSPd. It is difficult to ascribe the formation of DMSO solely to the conventionally accepted pathways of DMS oxidation by either bacterial activity or photochemical reactions. A direct biosynthetic production from phytoplankton or bacteria might be involved which means that DMSO in aquatic environments could act as a significant source of DMS rather than as a sink as generally supposed.


Author(s):  
I. C. Hedge

SynopsisThe Labiatae of SW Asia arc analysed. There is a major development of the family in this area with c. 1100 species, much morphological diversity, many illuminating distribution patterns and very high endemism levels; species endemism averages over 70% in the medium-sized and large genera. Areas of high concentrations of endemic taxa are indicated. The very significant differences between the Labiate floras of Turkey, Iran and Afghanistan throw doubt on designating all the steppic part of the area as Irano-Turanian; there is a strong Mediterranean floristic connection throughout much of Turkey and little evidence of Irano-Turanian influence. There are numerous taxonomically very isolated genera and species; some of these genera have very restricted distributions, a few are almost cosmopolitan.


1984 ◽  
Vol 49 (5) ◽  
pp. 1061-1078 ◽  
Author(s):  
Jiří Čeleda ◽  
Stanislav Škramovský

Based on the earlier paper introducing a concept of the apparent parachor of a solute in the solution, we have eliminated in the present work algebraically the effect which is introduced into this quantity by the additivity of the apparent molal volumes. The difference remaining from the apparent parachor after substracting the contribution corresponding to the apparent volume ( for which the present authors suggest the name metachor) was evaluated from the experimental values of the surface tension of aqueous solutions for a set of 1,1-, 1,2- and 2,1-valent electrolytes. This difference showed to be independent of concentration up to the very high values of the order of units mol dm-3 but it was directly proportional to the number of the free charges (with a proportionality factor 5 ± 1 cm3 mol-1 identical for all studied electrolytes). The metachor can be, for this reason, a suitable characteristic for detection of the association of ions and formation of complexes in the solutions of electrolytes, up to high concentrations where other methods are failing.


Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1607
Author(s):  
Mariano Venturini ◽  
Ariana Rossen ◽  
Patricia Silva Paulo

To produce nuclear fuels, it is necessary to convert uranium′s ore into UO2-ceramic grade, using several quantities of kerosene, methanol, nitric acid, ammonia, and, in low level, tributyl phosphate (TBP). Thus, the effluent generated by nuclear industries is one of the most toxic since it contains high concentrations of dangerous compounds. This paper explores biological parameters on real nuclear wastewater by the Monod model in an ORP controlled predicting the specific ammonia oxidation. Thermodynamic parameters were established using the Nernst equation to monitor Oxiders/Reductors relationship to obtain a correlation of these parameters to controlling and monitoring; that would allow technical operators to have better control of the nitrification process. The real nuclear effluent is formed by a mixture of two different lines of discharges, one composed of a high load of nitrogen, around 11,000 mg/L (N-NH4+-N-NO3−) and 600 mg/L Uranium, a second one, proceeds from uranium purification, containing TBP and COD that have to be removed. Bioprocesses were operated on real wastewater samples over 120 days under controlled ORP, as described by Nernst equations, which proved to be a robust tool to operate nitrification for larger periods with a very high load of nitrogen, uranium, and COD.


Author(s):  
Mario Vincenzo Russo ◽  
Ivan Notardonato ◽  
Alberto Rosada ◽  
Giuseppe Ianiri ◽  
Pasquale Avino

This paper shows a characterization of the organic and inorganic fraction of river waters (Tiber and Marta) and ores/soil samples collected in the Northern Latium region of Italy for evaluating the anthropogenic/natural source contribution to the environmental pollution of this area. For organic compounds, organochloride volatile compounds in Tiber and Marta rivers were analyzed by two different clean-up methods (i.e., liquid–liquid extraction and static headspace) followed by gas chromatography–electron capture detector (GC-ECD) analysis. The results show very high concentrations of bromoform (up to 1.82 and 3.2 µg L−1 in Tiber and Marta rivers, respectively), due to the presence of greenhouse crops, and of chloroform and tetrachloroethene, due to the presence of handicrafts installations. For the qualitative and quantitative assessment of the inorganic fraction, it is highlighted the use of a nuclear analytical method, instrumental neutron activation analysis, which allows having more information as possible from the sample without performing any chemical-physical pretreatment. The results have evidenced high levels of mercury (mean value 88.6 µg g−1), antimony (77.7 µg g−1), strontium (12,039 µg g−1) and zinc (103 µg g−1), whereas rare earth elements show levels similar to the literature data. Particular consideration is drawn for arsenic (414 µg g−1): the levels found in this paper (ranging between 1 and 5100 µg g−1) explain the high content of such element (as arsenates) in the aquifer, a big issue in this area.


1960 ◽  
Vol 38 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Ivan T. Beck ◽  
E. Pinter ◽  
R. D. McKenna ◽  
H. Griff

Acute hemorrhagic pancreatitis in humans is thought to be perpetuated by the autolytic processes catalyzed by trypsin and lipase. This study is an integral part of our search for trypsin and lipase inhibitors to be used in the treatment of this disease.Benzethonium chloride was found to inhibit tryptic activity in vitro. The proteolytic activity of rabbit's serum was inhibited, and the inhibition was most pronounced 6 to 12 hours after the subcutaneous injection of the compound. Fibrinolysin was also inhibited in vitro but benzethonium chloride had no inhibitory action on chymotrypsin, pepsin, or lipase.Serum proteins in vitro were precipitated only with very high concentrations of the compound. No significant protein changes were observed in sera of rabbits after the subcutaneous injection of the compound.


2007 ◽  
Vol 13 (2) ◽  
pp. 213-218
Author(s):  
Thomas W. Stief

Serine protease inactivators (serpins) are important regulators in biochemistry. Often it is necessary to block the serpin action, that is, to stabilize the sample. The guanidine group of arginine is the ligand for the active center pocket of many serine proteases. Arginine or guanidine inhibits serine proteases, and arginine belongs to the reactive P1-P1' center of many serpins. The plasmatic antithrombin, antiplasmin, or anti-C1-esterase activity was determined: A total of 20 µL of pooled normal plasma or 7% human albumin was added to 100 µL of 0—2.67 M arginine, pH 8.6, 10 µL of 26 mIU/mL thrombin in 7% human albumin, and 30 µL of 1.7 mM CHG-Ala-Arg-pNA (37°C). ΔA at 405 nm was determined, by using a microtiter plate reader. Thrombin was substituted by plasmin or C1-esterase, and the chromogenic peptide substrates <Glu-Phe-Lys-pNA or MeOC-Lys(eCBO)-Gly-Arg-pNA, respectively, were used. The IC50 of arginine against plasmatic antithrombin activity is 580 mM; the IC 25 is 440 mM. The IC25 of arginine against plasmatic α 2-antiplasmin or C1-inactivator is 1650 mM. The amidolytic activity of thrombin, plasmin, and C1-esterase is inhibited similarly by arginine: the IC50 for arginine against the amidolytic activity of these proteases is about 400 mM. Arginine at very high concentrations inhibits serpins. This is important, if stabilization of a biological fluid is a prerequisite for valid activities of serine proteases. In addition, these high concentrations of arginine might be a new gentle principle to inhibit pathogens that need serpins for their pathophysiology.


Blood ◽  
1975 ◽  
Vol 45 (1) ◽  
pp. 71-82 ◽  
Author(s):  
E Gimpert ◽  
M Jakob ◽  
WH Hitzig

Abstract Some characteristics of vitamin B12 binding and transport in the serum of an infant with congenital hereditary transcobalamin II (TC II) deficiency were studied using the following parameters and methods: vitamin B12 level and binding capacity; electrophoretic mobility in polyacrylamide gel electrophoresis; various immunodiffusion and absorption experiments, using a specific anti-TC II antiserum and the patient's serum as antigen. The results of these studies point to a deficient synthesis of TC II. Parenteral administration of high doses of vitamin B12 was followed by rapid and complete clinical remission and the appearance of vitamin B12 binder in the alpha 2 region which is similar to “fetal binder.” Thus, very high concentrations of vitamin B12, either carrier free or bound to this alpha 2 binder, were able to correct the disturbed physiology of TC II deficiency, presumably by normalization of DNA-thymine synthesis.


This work analyzes the state of snowpack in Nizhny Novgorod on the basis of certain chemical performances and integral biological toxicity. Snow samples were obtained in February 2018 along major highways of Nizhny Novgorod. A snow-covered area in Dubrava forestry was selected as reference. The studies demonstrated that the snowpack was characterized by very high concentrations of chlorides and sulfides: in sampling points of the Lower City, the content of chlorides and sulfates varied in the ranges of 24.67–62.36 mg/l and 30.16–62.09 mg/l, respectively, and in sampling points of the Upper City, this variability was 416.82–988.45 mg/l and 280.11–879.22 mg/l, respectively. The content of lead in snowpack in both the Lower City and the Upper City was approximately the same (0.0053 and 0.0048 mg/l). The minimum content of pollutants in snow samples from reference site was characterized by toxicity (10%, V = 6.0%) which was estimated as allowable (toxicity class 1). Snowpack water from the Lower City was characterized generally by medium toxicity (class 2), and sampled in the Upper City – by acute toxicity (59%, V = 26.5%), with regard to the reference (class 3).


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