Ecotoxicological effects of per- and polyfluoroalkyl substances (PFAS) and of a new PFAS adsorbing organoclay to immobilize PFAS in soils on earthworms and plants

A novel adsorptive organoclay (Intraplex A®) was developed for the in situ immobilization of per- and polyfluoroalkyl substances (PFAS) in the vadose zone. We provide the first evaluation of the effects of Intraplex A® on earthworms and plants in a PFAS-contaminated soil. Ecotoxicological tests were carried out on control soil with and without Intraplex A® (C + I and C, respectively) and PFAS-contaminated soil with and without Intraplex A® (PFAS + I and PFAS, respectively). We investigated the acute ecotoxicological effects of PFAS and Intraplex A® on the growth, reproduction and survival of earthworms (Eisenia fetida) and on plant growth (oat - Avena sativa and turnip - Brassica rapa L. silvestris). Earthworm lethality was 7.6 lower in PFAS + I than in PFAS soil. Earthworms avoided 100% C + I and PFAS + I soils, and reduced earthworms' reproduction was observed in both these soils. For both plant species, the PFAS + I soil yielded less fresh and dry shoot biomass than the PFAS soil, while root growth remained unaffected (all tests: p < 0.05). Soils with Intraplex A® had some negative effects on plants and earthworms, which must be balanced with its benefits as an in situ PFAS adsorbent.

Gas-phase photolysis of spiropentane at 147.0 nm

The gas-phase photolysis of spiropentane has been investigated using xenon (147.0 nm) resonance radiation. Major products observed in order of decreasing importance are ethylene, aliène, methylacetylene, 1,2-butadiene, acetylene, propylene, and vinylacetylene. Nitric oxide was used as a radical scavenger while hydrogen sulfide and hydrogen iodide were employed as radical interceptors in the determination of the relative importance of radical and molecular processes. CH3/CH2 and CH3C=C• radicals were identified and quantified. Seven primary reaction channels were postulated of which those involving the "elimination" of ethylene were the most predominant accounting for 71% of the photodecomposition.

Computer simulation of transport phenomena during dialysis deglycerolization of red blood cells

A computer simulation model has been developed to aid in the understanding, parameter prediction, and performance optimization of a unique dialysis process where glycerol is removed from cryopreserved red blood cells using a semipermeable membrane pouch fixed in a mildly agitated transport cell. The dynamic system considered here consists of flow channels and the membrane blood pouch which contains the red blood cells, extracellular fluid, and cryopreservatives. Dialysate flows over the membrane surfaces while salt enters the pouch preventing osmotic hemolysis. The glycerol diffuses rapidly from the red cells and plasma across the membrane into the dialysate which carries it out of the transport cell. The system is discretized into completely mixed subdomains. Constituent transport and solvent flux are modeled with the transient convection-diffusion equation and linear equations of nonequilibrium thermodynamics, respectively. The integrated compartment method was used to solve for the principal variables, that is, salt and glycerol concentrations, water flow rates, and pressure in space and time. The computer simulation model, calibrated and verified with in-house data sets, is a reliable, cost-effective and flexible tool for dialysis system investigations, prediction, and optimal design.

The relationship between sIgM positive lymph-node lymphocytes and breast cancer metastasis

The relative frequency of lymphocytes with surface immunoglobulins (sIgM, sIgG, sIgA) was studied in breast-cancer patients' axillary lymph nodes by the immunofluorescence technique. The study encompassed a total of 105 patients, most of whom had infiltrating ductal carcinoma (IDC). The results have indicated a significantly higher (p less than 0.005) average percentage of sIgM positive lymphocytes in lymph nodes in the group of IDC patients with lymph-node metastasis. Short-term followup was available for a limited number of patients, but no conclusions were reached with respect to sIgM positive lymphocytes. It is suggested that evaluation of axillary lymph-node and peripheral blood lymphocyte subpopulations for each cancer patient would provide new information which could aid in determining the extent of the disease process. Moreover, such information may be of assistance in decisions of therapeutic modalities, detection of occult metastasis, and prediction of prognosis.