Degradation mechanism, hydrocarbon polymers Final technical report

Degradation of hydrocarbon polymers by exposure to 275 F for 400 hours in presence and in absence of ammonium perchlorat

Land Degradation and Climate Change in Africa

Land degradation is rampant in Africa, accounting for 46% of the total land area. Land degradation at the current pace is projected to render more than half of the cultivated land in Africa unusable by 2050. Land degradation and climate change mutually reinforce each other, creating serious implications for food security, biodiversity and livelihoods in Africa. Effective early warning systems are an essential and important alert mechanism for addressing land degradation. An integrated landscape approach is a promising way to address the broad and multi-faceted nature of land degradation across Africa’s different agro-ecological zones

Estrogens promote misfolded proinsulin degradation to protect insulin production and delay diabetes

Summary: Conjugated estrogens (CE) delay the onset of type 2 diabetes (T2D) in postmenopausal women, but the mechanism is unclear. In T2D, the endoplasmic reticulum (ER) fails to promote proinsulin folding and, in failing to do so, promotes ER stress and β cell dysfunction. We show that CE prevent insulin-deficient diabetes in male and in female Akita mice using a model of misfolded proinsulin. CE stabilize the ER-associated protein degradation (ERAD) system and promote misfolded proinsulin proteasomal degradation. This involves activation of nuclear and membrane estrogen receptor-α (ERα), promoting transcriptional repression and proteasomal degradation of the ubiquitin-conjugating enzyme and ERAD degrader, UBC6e. The selective ERα modulator bazedoxifene mimics CE protection of β cells in females but not in males. : Estrogens prevent diabetes in women, but the mechanism is poorly understood. Xu et al. report that estrogens activate the endoplasmic-reticulum-associated protein degradation pathway, which promotes misfolded proinsulin degradation, suppresses endoplasmic reticulum stress, and protects insulin secretion in mice and in human pancreatic β cells. Keywords: estrogens, beta cell, islet, endoplasmic reticulum stress, proinsulin misfolding, diabetes, bazedoxifene, sex dimorphism, ERAD, SER

Drosophila Parkin requires PINK1 for mitochondrial translocation and ubiquitinates Mitofusin

Loss of the E3 ubiquitin ligase Parkin causes early onset Parkinson's disease, a neurodegenerative disorder of unknown etiology. Parkin has been linked to multiple cellular processes including protein degradation, mitochondrial homeostasis, and autophagy; however, its precise role in pathogenesis is unclear. Recent evidence suggests that Parkin is recruited to damaged mitochondria, possibly affecting mitochondrial fission and/or fusion, to mediate their autophagic turnover. The precise mechanism of recruitment and the ubiquitination target are unclear. Here we show in Drosophila cells that PINK1 is required to recruit Parkin to dysfunctional mitochondria and promote their degradation. Furthermore, PINK1 and Parkin mediate the ubiquitination of the profusion factor Mfn on the outer surface of mitochondria. Loss of Drosophila PINK1 or parkin causes an increase in Mfn abundance in vivo and concomitant elongation of mitochondria. These findings provide a molecular mechanism by which the PINK1/Parkin pathway affects mitochondrial fission/fusion as suggested by previous genetic interaction studies. We hypothesize that Mfn ubiquitination may provide a mechanism by which terminally damaged mitochondria are labeled and sequestered for degradation by autophagy

Identification of Thermal Degradation Process of Starch in Production of Environmentally Friendly Flocculants

Chemical modification of starch can be used to produce environmentally degradable flocculants. This is carried out at elevated temperature, which in turn causes thermal degradation, influencing the quality of the product. Starting from experimental results and the probabilistic nature of the process stochastic model was established to identify the rate and the mechanism of degradation under various conditions. It was concluded that applying moderate temperature around 143 Celsius ensures sufficient production rate without excessive thermal degradation

TGA/FTIR Studies on the Thermal Degradation of some Polymeric Sulfonic and Phosphonic Acids and Their Sodium Salts

The thermal degradation of poly(vinyl sulfonic acid) and its sodium salt, poly(4-styrenesulfonic acid) and its sodium salt, and poly(vinylphosphonic acid) was studied by a combination of techniques, including TGA/FTIR, to identify the volatile products which were evolved during the degradation as well as analysis of the residues which were obtained in order to propose a mechanism for the degradation. The motivation for the work was to attempt to identify new monomers which could be graft copolymerized onto a polymer in order to improve the thermal stability of that polymer