Thermoelectric properties of Ba8Ga16Ge30 with TiO2 nanoinclusions

The effects on thermal and electrical properties of adding small amounts of TiO2 nanoinclusions to bulk Ba8Ga16Ge30 clathrate have been investigated. The thermal properties were analysed using the transient plane source technique and the analysis showed a significant decrease in thermal conductivity as the volume fraction of TiO2 increased from 0 vol. % to 1.2 vol. %. The introduction of TiO2 nanoparticles caused a shift in the peak value of the Seebeck coefficient towards lower temperatures. The maximum value of the Seebeck coefficient was, however, only little affected. The introduction of TiO2 nanoparticles into the bulk Ba8Ga16Ge30 resulted in an increased electrical resistivity of the sample, thus simultaneously reducing the charge carrier contribution to the thermal conductivity, partly explaining the decrease in total thermal conductivity. Due to the large increase in resistivity of the samples, ZT was only somewhat improved for the material with 0.4 vol. % TiO2 while the ZT values of the other materials were lower than for the reference Ba8Ga16Ge30 material without TiO2 nanoparticles. The combined results are consistent with a scenario where the nanoparticle introduction causes a light doping of the semiconductor matrix and an increased concentration of phonon scattering centres

FIRST REVIEW OF THE LYNCODONTINI MATERIAL (MUSTELIDAE, CARNIVORA, MAMMALIA) FROM THE LOWER PLEISTOCENE ARCHAEO-PALAEONTOLOGICAL SITES OF ORCE (SOUTHEASTERN SPAIN)

Two archaeo-palaeontological Lower Pleistocene sites of Orce (Baza Basin, SE Spain), Fuente Nueva 3 (1.3 Ma) and Barranco León (1.4 Ma), preserve some of the earliest evidences of human presence in the European continent. During the 2013 field season, a small Lyncodontini mustelid mandible was found at Fuente Nueva-3. This finding was accompanied by a lower canine (c1), also from the same site, and a lower fourth premolar (p4) from Barranco León. Here, we report on the morphological and biometrical study of these materials, in comparison to other Eurasian Pliocene-Pleistocene species of the tribe Lyncodontini. The analyses revealed an affinity between the taxon from Fuente Nueva-3 and Barranco León with the small-sized European species Martellictis ardea (Gervais, 1848-1852), allowing us to ascribe the described material to the latter species. The presence of M. ardea in the sites of Orce is the southernmost occurrence of the species in the Iberian Peninsula and an important finding in the scarce fossil record of Lyncodontini in Europe

Lymph node tissue kallikrein-related peptidase 6 mRNA: a progression marker for colorectal cancer

BACKGROUND: A most important characteristic feature for poor prognosis in colorectal cancer (CRC) is the presence of lymph node metastasis. Determination of carcinoembryonic antigen (CEA) mRNA levels in lymph nodes has proven powerful for quantification of disseminated tumour cells. Here, we investigate the utility of human tissue kallikrein-related peptidase 6 (KLK6) mRNA as a progression biomarker to complement CEA mRNA, for improved selection of patients in need of adjuvant therapy and intensified follow-up after surgery. METHODS: Lymph nodes of pTNM stage I-IV CRC-(166 patients/503 lymph nodes) and control (23/108) patients were collected at surgery and analysed by quantitative RT-PCR. RESULTS: Lymph node KLK6 positivity was an indicator of poor outcome (hazard ratio 3.7). Risk of recurrence and cancer death increased with KLK6 lymph node levels. Patients with KLK6 lymph node levels above the 90th percentile had a hazard ratio of 6.5 and 76 months shorter average survival time compared to patients with KLK6 negative nodes. The KLK6 positivity in lymph nodes with few tumour cells, that is, low CEA mRNA levels, also indicated poor prognosis (hazard ratio 2.8). CONCLUSION: In CRC patients, lymph node KLK6 positivity indicated presence of aggressive tumour cells associated with poor prognosis and high risk of tumour recurrence. British Journal of Cancer (2012) 107, 150-157. doi: 10.1038/bjc.2012.220 www.bjcancer.com Published online 14 June 2012 (C) 2012 Cancer Research U

Omfang og effekter af mikroplast forurening i jord - med særligt fokus på recirkulering af affaldsprodukter

• Mikroplast forekommer i restprodukter fra menneskers husholdning, som kan bruges som gødning på marker. Der er mange gode grunde til at genanvende restprodukterne, men tvivl om mikroplasts effekter på jordens fertilitet begrænser genanvendelsen. • Der er mikroplast i organisk husholdningsaffald og spildevandsslam, men et klart og nuanceret billede af indholdet findes ikke. Spildevandsslam indeholder mange små partikler (primært fibre og fragmenter), hvorimod organisk husholdningsaffald indeholder flere større fragmenter (flager fra emballage og poser). Der er indikation på at kompost indeholder flest partikler pr. fosforenhed. • Mikroplast findes i jorden, men der er få studier der har målt koncentrationen på masseenhed. Der findes ikke sammenlignelige data mellem felt- og laboratorieforsøg, ligesom der ikke findes studier der evaluerer massebalancen af mikroplast (og derved nedbrydning), og det er endnu ikke klart i hvilket omfang restprodukter anvendt som gødning bidrager til forurening af jorden sammenlignet med andre kilder (landbrugsplast, henkastning af affald, bearbejdning af jorden mv.). • Forskning inden for mikroplast-effekter i jordmiljøet er et relativt nyt område, hvor de fleste resultater indtil videre er fra laboratorieforsøg. Laboratorieforsøg bruger ofte reducerede systemer, ligesom de ofte bruger højere koncentrationer end man vil forvente at finde i feltforsøg. Det kan give udfordringer i forhold til tolkningen, hvis man forsøger at overføre disse resultater til feltskala. • Det er vist i nogle laboratorieforsøg at mikroplast kan have en effekt på jordlevende organismer. Mange organismer indtager småt mikroplast, hvilket potentielt kan have forskellige negative virkninger på organismen, og kan fungere som første led i bioakkumulering af mikroplast. Der er dog på nuværende tidspunkt ikke konsensus i litteraturen (nogle studier viser negative effekter, mens andre ikke finder effekter af mikroplast), og antallet af effekt-studier foretaget ved miljørealistiske plastkoncentrationer og under miljørealistiske eksponeringsscenarier er stadig begrænset. • Det er observeret at mikroplast tilsat jord i meget høje koncentrationer kan have en negativ effekt på plantevækst, men det antages at det i særlig grad er indirekte effekter, såsom ændret næringsstoftilgængelighed, forandringer i jordstrukturen og dermed jordens evne til at dræne eller tilbageholde vand, samt planters mulighed for at indgå symbioser med organismer som mykorrhiza-svampe og Rhizobium-bakterier. Egentlige strukturelle ændringer af jorden som følge af mikroplastforurening, må antages først at ske ved meget høje mikroplast-koncentrationer. • I laboratoriestudier er det vist at både struktur og funktion af mikrobielle samfund kan påvirkes af eksponering til mikroplast, men generelt undersøges og observeres effekterne ved mikroplast-koncentrationer, som er højere end de koncentrationer der er målt i almindelig landbrugsjord. • Andre fremmedstoffer som organisk forurening og tungmetaller kan adsorberes til mikroplast. Det gør at mikroplast kan fungere som bærer af fremmedstoffer, hvis organismer indtager det, men samtidig kan det også gøre fremmedstoffer mindre tilgængelige for eksempelvis planter og dyr. • CRUCIAL-forsøget er gødet med komposteret husholdningsaffald og spildevandsslam i 20 år, i niveauer som er højere end tilladt (svarende til over 100 års tilførsel). Derfor forventes det at eventuelle skadelige stoffer (mikroplast, tungmetaller, organisk forurening) i produkterne er akkumuleret til et niveau der svarer til, eller er højere end den akkumulering man kunne forvente ved mere end 100 års almindelig gødningspraksis. Det skal bemærkes, at vi endnu ikke har kvantificeret plastindholdet i CRUCIAL jord eller de tilførte gødningsprodukter, men foreløbige pilotanalyser af jord fra CRUCIAL indikerer at der er store forskelle i både plastindhold og plasttype i jord fra de forskellige gødningsbehandlinger. Vi har ikke fundet skadelige virkninger af tilførte affaldsprodukter på regnormesamfund, potentialet for kvælstoffiksering eller jordens fødenet. • Tilførslen af spildevandsslam og komposteret husholdningsaffald i CRUCIAL-forsøget har fremmet jordens sundhed, hvad angår mikroorganismer, dyr og planters trivsel sammenlignet med ugødet jord. Produkterne har bidraget til et højere indhold af organisk stof i jorderne, og fungeret som næring, samtidigt med at der ikke er fundet indikationer på utilsigtede virkninger af en cocktail af uønskede stoffer, herunder mikroplast, tungmetaller og organiske fremmedstoffer, vi antager er tilført med særligt de organiske gødningsprodukter over årene. • I fremtidige studier bør der især fokuseres på at inkludere felt- og storskala model-økosystem-forsøg. For at kunne sammenligne forskellige studier er det nødvendigt at standardisere metoder til prøvetagning og måling af koncentrationen af mikroplast i gødning og jord. Desuden er det vigtigt at undersøge effekten af mikroplast på jordlevende organismer i felten eller i terrestriske model-økosystemer

Do contaminants compromise the use of recycled nutrients in organic agriculture? A review and synthesis of current knowledge on contaminant concentrations, fate in the environment and risk assessment

Use of nutrients recycled from societal waste streams in agriculture is part of the circular economy, and in line with organic farming principles. Nevertheless, diverse contaminants in waste streams create doubts among organic farmers about potential risks for soil health. Here, we gather the current knowledge on contaminant levels in waste streams and recycled nutrient sources, and discuss associated risks. For potentially toxic elements (PTEs), the input of zinc (Zn) and copper (Cu) from mineral feed supplements remains of concern, while concentrations of PTEs in many waste streams have decreased substantially in Europe. The same applies to organic contaminants, although new chemical groups such as flame retardants are of emerging concern and globally contamination levels differ strongly. Compared to inorganic fertilizers, application of organic fertilizers derived from human or animal feces is associated with an increased risk for environmental dissemination of antibiotic resistance. The risk depends on the quality of the organic fertilizers, which varies between geographical regions, but farmland application of sewage sludge appears to be a safe practice as shown by some studies (e.g. from Sweden). Microplastic concentrations in agricultural soils show a wide spread and our understanding of its toxicity is limited, hampering a sound risk assessment. Methods for assessing public health risks for organic contaminants must include emerging contaminants and potential interactions of multiple compounds. Evidence from long-term field experiments suggests that soils may be more resilient and capable to degrade or stabilize pollutants than often assumed. In view of the need to source nutrients for expanding areas under organic farming, we discuss inputs originating from conventional farms vs. non-agricultural (i.e. societal) inputs. Closing nutrient cycles between agriculture and society is feasible in many cases, without being compromised by contaminants, and should be enhanced, aided by improved source control, waste treatment and sound risk assessments

Soluble P-tau217 reflects amyloid and tau pathology and mediates the association of amyloid with tau

Alzheimer\u27s disease is characterized by β-amyloid plaques and tau tangles. Plasma levels of phospho-tau217 (P-tau217) accurately differentiate Alzheimer\u27s disease dementia from other dementias, but it is unclear to what degree this reflects β-amyloid plaque accumulation, tau tangle accumulation, or both. In a cohort with post-mortem neuropathological data (N = 88), both plaque and tangle density contributed independently to higher P-tau217, but P-tau217 was not elevated in patients with non-Alzheimer\u27s disease tauopathies (N = 9). Several findings were replicated in a cohort with PET imaging ( BioFINDER-2 , N = 426), where β-amyloid and tau PET were independently associated with P-tau217. P-tau217 concentrations correlated with β-amyloid PET (but not tau PET) in early disease stages and with both β-amyloid and (more strongly) tau PET in late disease stages. Finally, P-tau217 mediated the association between β-amyloid and tau in both cohorts, especially for tau outside of the medial temporal lobe. These findings support the hypothesis that plasma P-tau217 concentration is increased by both β-amyloid plaques and tau tangles and is congruent with the hypothesis that P-tau is involved in β-amyloid-dependent formation of neocortical tau tangles