An excess of elemental sulfur is generated annually from hydrodesulfurization in petroleum refining processes; however, it has a limited number of uses, of which one example is the production of sulfuric acid. Despite this excess, the development of synthetic and processing methods to convert elemental sulfur into useful chemical substances has not been investigated widely. Here we report a facile method (termed 'inverse vulcanization') to prepare chemically stable and processable polymeric materials through the direct copolymerization of elemental sulfur with vinylic monomers. This methodology enabled the modification of sulfur into processable copolymer forms with tunable thermomechanical properties, which leads to well-defined sulfur-rich micropatterned films created by imprint lithography. We also demonstrate that these copolymers exhibit comparable electrochemical properties to elemental sulfur and could serve as the active material in Li-S batteries, exhibiting high specific capacity (823 mA h g(-1) at 100 cycles) and enhanced capacity retention.
Polymers for IR imaging: The preparation of high refractive index polymers (n = 1.75 to 1.86) via the inverse vulcanization of elemental sulfur is reported. High quality imaging in the near (1.5 μm) and mid-IR (3-5 μm) regions using high refractive index polymeric lenses from these sulfur materials was demonstrated.
Sulfur-rich copolymers based on poly(sulfurrandom-1,3-diisopropenylbenzene) (poly(S-r-DIB)) were synthesized via inverse vulcanization to create cathode materials for lithium−sulfur battery applications. These materials exhibit enhanced capacity retention (1005 mAh/g at 100 cycles) and battery lifetimes over 500 cycles at a C/10 rate. These poly(Sr-DIB) copolymers represent a new class of polymeric electrode materials that exhibit one of the highest charge capacities reported, particularly after extended charge− discharge cycling in Li−S batteries.
The pathogenesis of nonalcoholic steatohepatitis (NASH) is unclear, despite epidemiological data implicating FFAs. We studied the pathogenesis of NASH using lipoapoptosis models. Palmitic acid (PA) induced classical apoptosis of hepatocytes. PA-induced lipoapoptosis was inhibited by acyl-CoA synthetase inhibitor but not by ceramide synthesis inhibitors, suggesting that conversion products other than ceramide are involved. Phospholipase A 2 (PLA 2 ) inhibitors blocked PA-induced hepatocyte death, suggesting an important role for PLA 2 and its product lysophosphatidylcholine (LPC). Small interfering RNA for Ca 21 -independent phospholipase A 2 (iPLA 2 ) inhibited the lipoapoptosis of hepatocytes. PA increased LPC content, which was reversed by iPLA 2 inhibitors. Pertussis toxin or dominant-negative Ga i mutant inhibited hepatocyte death by PA or LPC acting through G-protein-coupled receptor (GPCR)/Ga i . PA decreased cardiolipin content and induced mitochondrial potential loss and cytochrome c translocation. Oleic acid inhibited PA-induced hepatocyte death by diverting PA to triglyceride and decreasing LPC content, suggesting that FFAs lead to steatosis or lipoapoptosis according to the abundance of saturated/unsaturated FFAs. LPC administration induced hepatitis in vivo. LPC content was increased in the liver specimens from NASH patients. These results demonstrate that LPC is a death effector in the lipoapoptosis of hepatocytes and suggest potential therapeutic values of PLA 2 inhibitors or GPCR/ Ga i inhibitors in
Background & Aims-The generation of oxidative stress and TGF-β1 production play important roles in liver fibrogenesis. We have previously shown that HCV increases hepatocyte TGF-β1 expression. However, the mechanisms by which this induction occurs have not been well studied. We explored the possibility that HCV infection regulates TGF-β1 expression through generation of reactive oxygen species (ROS), which act through one or more of the p38 MAPK, ERK, JNK, and NFκB signaling pathways to induce TGF-β1 expression.
Tumor size and fibrosis are important factors related to complications during colorectal ESD. Younger age and development of abdominal pain can predict the hospital course in patients with perforation after ESD.
HAIC is comparable with sorafenib in terms of OS and TTP in advanced HCC patients with PVTT. HAIC shows more favorable treatment responses compared with sorafenib. Therefore, HAIC might be an alternative treatment modality to sorafenib in advanced HCC patients with PVTT.
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