Identifying microplastic litter with Laser Induced Breakdown Spectroscopy: A first approach.

The broad diversity of microplastic litter requires a selection of analytical techniques to reliably determine the particle's chemical composition. This study demonstrates that Laser Induced Breakdown Spectroscopy (LIBS) can identify microplastic particles based on their spectral fingerprints. By studying the spectral features of polymer reference spectra, microplastic litter can be distinguished from non-plastic materials. The results show that LIBS can be used as a fast in-situ technique for pre-characterization of the microparticle's material and is a possible tool for environmental studies on microplastics.

Reduced brain-derived neurotrophic factor is associated with a loss of serotonergic innervation in the hippocampus of aging mice.

Brain-derived neurotrophic factor (BDNF) regulates monoamine neuronal growth, survival and function in development and throughout adulthood. At 18 months of age, mice with constitutive reductions in BDNF expression show decreased serotonin innervation in the hippocampus compared with age-matched wildtype mice. It is not known, however, whether age-accelerated loss of serotonergic innervation in BDNF(+/-) mice occurs in other brain regions, advances beyond 18 months or is associated with alterations in other neurotransmitter systems. In this study, immunocytochemistry was used to assess serotonergic and catecholaminergic innervation in 26-month-old BDNF(+/-) mice. Age-related loss of serotonin axons in the hippocampus was potentiated in BDNF(+/-) mice compared with wildtype mice at this late age, particularly in the CA1 subregion. By contrast, aging BDNF(+/-) mice showed increased serotonin innervation of the basomedial nucleus of the amygdala. In the noradrenergic system, BDNF(+/-) mice showed reduced numbers of cell bodies and fibers in the locus coeruleus compared with age-matched wildtype mice, whereas no changes were observed in dopaminergic innervation with respect to genotype. In vivo zero net flux microdialysis in awake mice showed a significant decrease in extracellular serotonin levels in the hippocampus in BDNF(+/-) mice at 20 months of age. Thus, reduced BDNF is associated with altered serotonergic and noradrenergic innervation in aging mice and, in particular, with accelerated loss of serotonergic innervation to the hippocampus that is manifest as a decrease in basal neurotransmission.

Dietary fat reduction strategies.

In this study, we used computer modeling to identify which techniques designed to achieve dietary fat reduction were the most effective in meeting the dietary recommendations of the American Heart Association Step-One diet. Menus were developed for men and nonpregnant, nonlactating women, 25 to 50 years old, according to the Continuing Survey of Food Intakes by Individuals (with 36% and 37% of energy from fat for men and women respectively). The menus were modified realistically using the Minnesota Nutrition Data System. The following five strategies were applied: skim milk replaced whole milk and 2%-fat milk (SKM); medium-fat meat exchanges replaced higher-fat ones (MMtEx); lean meat exchanges replaced higher-fat ones (LMtEx); fat-modified products were used (FMP); and 2%-fat milk replaced whole milk (LFM). For men, strategies LMtEx, SKM + LMtEx, SKM + LMtEx + FMP, LMtEx + FMP, LMtEx + FMP + LFM, and LMtEx + LFM reduced energy by 195 to 415 kcal and achieved the targeted level of energy from fat (less than or equal to 30 +/- 1%) and cholesterol (less than 300 mg) while maintaining 67% or more of the Recommended Dietary Allowances for other nutrients. For women, however, no single strategy achieved the goal. Certain combinations of strategies, SKM + LMtEx, SKM + FMP, SKM + MMtEx + FMP, reduced energy by 150 to 268 kcal and achieved the targeted dietary fat and cholesterol goals while maintaining 67% or more of the Recommended Dietary Allowances for other nutrients. All strategies led to a reduction in both saturated fatty acids (to 9% to 10% of energy) and monounsaturated fatty acids.(ABSTRACT TRUNCATED AT 250 WORDS)