Activity

Groundwater is projected to become an increasing source of freshwater and nutrients to the Arctic Ocean as permafrost thaws, yet few studies have quantified groundwater inputs to Arctic coastal waters under contemporary conditions. New measurements along the Alaska Beaufort Sea coast show that dissolved organic carbon and nitrogen (DOC and DON) concentrations in supra-permafrost groundwater (SPGW) near the land-sea interface are up to two orders of magnitude higher than in rivers. This dissolved organic matter (DOM) is sourced from readily leachable organic matter in surface soils and deeper centuries-to millennia-old soils that extend into thawing permafrost. SPGW delivers approximately 400-2100 m3 of freshwater, 14-71 kg of DOC, and 1-4 kg of DON to the coastal ocean per km of shoreline per day during late summer. These substantial fluxes are expected to increase as massive stocks of frozen organic matter in permafrost are liberated in a warming Arctic.Epigallocatechin-3-gallate (EGCG), a green tea-derived polyphenol, exhibits antitumor activities. An EGCG nanoemulsion (nano-EGCG) was prepared to improve the stability and reduce the side effects of EGCG for treatment of human lung cancer cells, and the antitumor effects were studied. The possible molecular mechanism underlying its antitumor effects on cultured human lung cancer cells was also elucidated. The antitumor effects of EGCG and nano-EGCG were determined using methylthiazolyldiphenyl-tetrazolium bromide (MTT), colony formation, migration, and invasion assays. In addition, changes in the AMP-activated protein kinase (AMPK) signaling pathway were investigated using Western blot analyses. AMPK inhibitors were used to determine the roles of the AMPK signaling pathway involved in the molecular mechanism of the nano-EGCG. Our results showed that both EGCG and nano-EGCG inhibited the growth of H1299 lung cancer cells, with half-maximal inhibitory concentrations of 36.03 and 4.71 μM, respectively. learn more Additionally, nano-EGCG effectively suppressed lung cancer cell colony formation, migration, and invasion in a dose-dependent manner. Nano-EGCG may inhibit lung cancer cell invasion through matrix metalloproteinase (MMP)-2- and MMP-9-independent mechanisms. Furthermore, the expression of several key regulatory proteins in the AMPK signaling pathway was modulated by nano-EGCG. Nano-EGCG may inhibit lung cancer cell proliferation, colony formation, migration, and invasion through the activation of AMPK signaling pathways. This novel mechanism of nano-EGCG suggests its application in lung cancer prevention and treatment. Our results provide an experimental foundation for further research on its potential activities and effects in vivo.Although certain microbial lipids are toxins, the structural features important for cytotoxicity remain unknown. Increased functional understanding is essential for developing therapeutics against toxic microbial lipids. Group B Streptococci (GBS) are bacteria associated with preterm births, stillbirths, and severe infections in neonates and adults. GBS produce a pigmented, cytotoxic lipid, known as granadaene. Despite its importance to all manifestations of GBS disease, studies towards understanding granadaene’s toxic activity are hindered by its instability and insolubility in purified form. Here, we report the synthesis and screening of lipid derivatives inspired by granadaene, which reveal features central to toxin function, namely the polyene chain length. Furthermore, we show that vaccination with a non-toxic synthetic analog confers the production of antibodies that inhibit granadaene-mediated hemolysis ex vivo and diminish GBS infection in vivo. This work provides unique structural and functional insight into granadaene and a strategy to mitigate GBS infection, which will be relevant to other toxic lipids encoded by human pathogens.Communication networks have multiple users, each sending and receiving messages. A multiple access channel (MAC) models multiple senders transmitting to a single receiver, such as the uplink from many mobile phones to a single base station. The optimal performance of a MAC is quantified by a capacity region of simultaneously achievable communication rates. We study the two-sender classical MAC, the simplest and best-understood network, and find a surprising richness in both a classical and quantum context. First, we find that quantum entanglement shared between senders can substantially boost the capacity of a classical MAC. Second, we find that optimal performance of a MAC with bounded-size inputs may require unbounded amounts of entanglement. Third, determining whether a perfect communication rate is achievable using finite-dimensional entanglement is undecidable. Finally, we show that evaluating the capacity region of a two-sender classical MAC is in fact NP-hard.The function of the hyperpolarization-activated cyclic nucleotide-gated channel 1 (HCN1) and the expression of brain-derived neurotrophic factor (BDNF) may be involved in the pathogenesis of post-traumatic stress disorder (PTSD). This study aims to explore the role of the HCN1 channel, BDNF, and mTOR in the actions of PTSD and to examine whether synaptic transmission or plasticity is involved in the regulation of this disease. In the present study, rats were exposed to the single prolonged stress and electric foot shock (SPS&S) procedure, which can induce PTSD-like behaviors in rats. ZD7288 was administered by intracerebroventricular (i.c.v.) injection to one experimental group to inhibit the function of the HCN1 ion channel while 8-Br-cAMP was administered to another group to activate the function of the HCN1 ion channel. A series of behavioral tests and biochemical assessments of certain proteins (HCN1, BDNF, and pmTOR) and synaptic ultrastructure in the prefrontal cortex (PFC) and hippocampus (Hip) were thregulated BDNF-mTOR signaling pathways and synaptic transmission.Recent studies showed that peroxisome proliferator-activated receptors (PPARs) had effects on the progression of multiple tumors, but the role of PPARD and PPARG in glioma remains poorly understand. We conducted a case-control study to investigate the association of polymorphisms in PPARD and PPARG with glioma risk and prognosis in the Chinese Han population. Seven polymorphisms (PPARD rs2016520, rs67056409, rs1053049 and rs2206030; PPARG rs2920503, rs4073770 and rs1151988) were genotyped using the Agena MassARRAY system in 568 glioma patients and 509 healthy controls. The odd ratios (OR) and 95% confidence interval (CI) were calculated to assess the association of PPARD and PPARG polymorphisms with glioma risk. The Multifactor dimensionality reduction (MDR) method was used to analysis interactions of genetic polymorphisms on glioma risk. Then, we conducted log-rank test, Kaplan-Meier analysis and Cox regression model to evaluate the relationship of PPARD and PPARG polymorphisms with glioma prognosis. We found PPARD polymorphisms (rs2016520, rs67056409, rs1053049) were significantly associated with glioma risk in multiple models (P  40 and astrocytoma (P  less then  0.