Element concentrations in wild edible mushrooms in Finland

The aim of the study was to examine the element concentrations of common mushroom species and to evaluate the possible health risks resulting from the consumption of mushrooms. The concentration of Ag, Al, Ca, Co, Cr, Cu, Fe, Hg, Mg, Mn, Mo, Pt, Rb, Se, V and Zn was studied for ten commercially sold mushroom species and two other common edible species in southern Finland. The element concentrations were analysed using AAS for selenium, fluorometry for mercury and ICP-MS for the other 14 elements. The platinum concentration was lower than the detection limit for all mushrooms species (n = 191). The highest aluminium, calcium and vanadium concentration were found in Boletus species. The amounts of mushroom considered safe for consumption were mostly limited by rubidium. When excluding Rb, the maximum amounts of mushroom recommended for consumption were limited by the concentration of chromium in the case of nine of the 12 studied fungi species. Iron was a limiting element for the safe consumption of Suillus variegatus while Agaricus abruptibulbus and Boletus species were limited by silver. In the light of the results the ten commercially sold mushroom species are mainly considered safe to consume. Nevertheless, it is recommended to avoid the consumption of A. abruptibulbus and to consume Boletus species and Suillus variegatus in moderate amounts only

Concentration of fecal calprotectin in 11,255 children aged 0-18 years

Objectives Fecal calprotectin is a valued surrogate marker for intestinal inflammation. It has been argued that calprotectin levels are higher in early age than in later life hampering the use of calprotectin in young children. Subjects and methods To study age-related variation, we used data from our laboratory information system on consecutive, unselected fecal calprotectin measurements from 2014 to 2017 in all children aged 0 to 18 years. From each individual, the first measurement was included and repeated measurements were excluded. Fecal calprotectin was quantitated in the major clinical laboratory in southern Finland, HUSLAB with an ELISA kit from Calpro AS (Calpro/Calprolab, Oslo, Norway). Currently, the assay is performed on two automatic pipetting analysers (Dynex DS2, Chantilly, USA) according to the instructions of the manufacturer. Results There were altogether 11,255 fecal calprotectin results from as many children. The median level of fecal calprotectin was 51 mg/kg in infants 100 mg/kg increased with increasing age. Conclusions Fecal calprotectin values in children beyond the first year of life are in general low and comparable in children and adolescents.Peer reviewe

Cadmium, lead, arsenic and nickel in wild edible mushrooms

The aim of the study was to study the geographical and temporal variation of Cd, Pb, As and Ni in wild edible mushrooms and to evaluate possible toxicological risks resulting from their consumption. The research focused on 12 mushroom species commonly collected in Finland. The samples were collected at common collection sites in Southern Finland between the years 1977 and 1999 and analysed using ICP-MS. The median dry weight concentrations ranged between 0.22-29.70 mg kg-1 d.w. for Cd, 0.36-6.05 mg kg-1 d.w. for Pb, 0.14-5.11 mg kg-1 d.w. for As and 0.41-9.08 mg kg-1 d.w. for Ni. The highest concentrations of Cd, Pb and As were found in Agaricus abruptibulbus and the highest level of Ni in Albatrellus ovinus. The Pb concentrations in A. abruptibulbus and Cd levels in Lactarius species were found to be significantly higher at polluted than at unpolluted sites. The Pb contents of A. ovinus, Boletus species, Cantharellus tubaeformis and Lactarius species as well as Cd levels of A. abruptibulbus and Leccinum species were signifi cantly higher for samples collected in 1977-1983 than for ones collected in 1992-1999. Decomposer species had generally higher concentrations of Cd, Pb and As than mycorrhizal fungi. Apart from the high element concentrations of A. abruptibulbus, the consumption of mushrooms was generally not considered to pose a toxicological risk in the light of the safety limits set by WHO. However, the Cd and Pb contents in A. abruptibulbus and Cd levels of Gyromitra esculenta and Boletus species exceeded the EU maximum permitted concentrations for cultivated mushrooms

Computational studies of silicon interfaces and amorphous silica

Computational simulations are a new branch of science where one can perform computational experiments by simulating a model system. The model contains an approximation of a real system with simplified physical laws and reduced size in order to make it computationally tractable. Many physical systems cannot be analytically solved and also experimentally not everything can be measured. Computational simulations fill the gaps and allow new kinds of problems to be addressed. Two main issues are studied in this thesis with computational simulations. The first issue concerns interfaces in silicon and is studied with deterministic molecular dynamics simulations. The second issue concerns the amorphous state of silicon and silica created with a stochastic algorithm. As for the first issue the first study is a preliminary investigation of the heat conductivity over an amorphous-crystalline interface in silicon. Second, we present a methodology for calculating the life-time of large amorphous clusters embedded in a crystalline matrix by simulating much smaller clusters. We employ this methodology to study amorphous silicon clusters and find that the activation energy of the boundary movement is temperature dependent with a change in behavior at 1150 K. The last problem concerns the structure of twist grain boundaries at 0 K. We present detailed simulations where we explore many possible grain boundary structures by allowing the number of atoms at the interface to change. This is a degree of freedom that has not been previously considered in computational studies and proved to be of utmost importance. We find that the twist grain boundaries have ordered structures at 0 K for atomic densities at the interface not previously considered. We also find that the structural unit model is valid for twist grain boundaries and present the structural units forming the boundary. The second issue concerns the amorphous state of silicon and silica. With a stochastic Monte Carlo simulation method that operates on the bond network of silicon and silica, we have created both amorphous silicon and silica. We find that we can improve the structural description of amorphous silica by adjusting the potential model. In addition, we developed optimizations for the simulation method which made it tractable for larger systems.reviewe