Background: Traumatic brain injury (TBI) is characterized by high mortality and disability rates. Disease-associated microglia (DAM) are a newly discovered subtype of microglia. However, their presence and function in the acute phase of TBI remain unclear.
View Article and Find Full Text PDFSubarachnoid hemorrhage (SAH) often leads to long-term cognitive deficits in patients, particularly due to injury to brain regions such as the hippocampus. This study aims to investigate the role of the triggering receptor expressed on myeloid cells 2 (TREM2) in mitigating hippocampal injury and associated cognitive impairments following SAH. To explore the protective effects of TREM2, we utilized the TREM2 agonist COG1410 to upregulate TREM2 expression and employed TREM2 knockout (KO) mice to verify the necessity of TREM2 for this protective role.
View Article and Find Full Text PDFBackground: The gut microbiota plays a critical role in regulating brain function through the microbiome-gut-brain axis (MGBA). Dysbiosis of the gut microbiota is associated with neurological impairment in Traumatic brain injury (TBI) patients. Our previous study found that TBI results in a decrease in the abundance of Prevotella copri (P.
View Article and Find Full Text PDFStepwise metalation of the hexadentate ligand LH (LH = 1,3,5-CH(NHCH--NHSiMeBu)) affords bimetallic trinuclear clusters (L)FeZn(thf) and (L)FeZn(py). Reactivity studies were pursued to understand metal atom lability as the clusters undergo ligand substitution, redox chemistry, and group transfer processes. Chloride addition to (L)FeZn(thf) resulted in a mixture of species including both all-zinc and all-iron products.
View Article and Find Full Text PDFBackground: Because physician practices contribute to national healthcare expenditures, initiatives aimed at educating physicians about high-value cost-conscious care (HVCCC) are important. Prior studies suggest that the training environment influences physician attitudes and behaviors towards HVCCC.
Objective: To explore the relationship between medical student experiences and HVCCC attitudes.
Background: White matter injury (WMI) is an important pathological process after traumatic brain injury (TBI). The correlation between white matter functions and the myeloid cells expressing triggering receptor-2 (TREM2) has been convincingly demonstrated. Moreover, a recent study revealed that microglial sterol metabolism is crucial for early remyelination after demyelinating diseases.
View Article and Find Full Text PDFEfforts to produce aromatic monomers through catalytic lignin depolymerization have historically focused on aryl-ether bond cleavage. A large fraction of aromatic monomers in lignin, however, are linked by various carbon-carbon (C-C) bonds that are more challenging to cleave and limit the yields of aromatic monomers from lignin depolymerization. Here, we report a catalytic autoxidation method to cleave C-C bonds in lignin-derived dimers and oligomers from pine and poplar.
View Article and Find Full Text PDFSelective lignin depolymerization is a key step in lignin valorization to value-added products, and there are multiple catalytic methods to cleave labile aryl-ether bonds in lignin. However, the overall aromatic monomer yield is inherently limited by refractory carbon-carbon linkages, which are abundant in lignin and remain intact during most selective lignin deconstruction processes. In this work, we demonstrate that a Co/Mn/Br-based catalytic autoxidation method promotes carbon-carbon bond cleavage in acetylated lignin oligomers produced from reductive catalytic fractionation.
View Article and Find Full Text PDFMyelin sheath injury contributes to cognitive deficits following subarachnoid hemorrhage (SAH). G protein-coupled receptor 17 (GPR17), a membrane receptor, negatively regulates oligodendrocyte precursor cell (OPC) differentiation in both developmental and pathological contexts. Nonetheless, GPR17's role in modulating OPC differentiation, facilitating remyelination post SAH, and its interaction with downstream molecules remain elusive.
View Article and Find Full Text PDFBackground: Neuroinflammation is one of the most important processes in secondary injury after traumatic brain injury (TBI). Triggering receptor expressed on myeloid cells 2 (TREM2) has been proven to exert neuroprotective effects in neurodegenerative diseases and stroke by modulating neuroinflammation, and promoting phagocytosis and cell survival. However, the role of TREM2 in TBI has not yet been elucidated.
View Article and Find Full Text PDFM(NH ) intermediates involved in N-N bond formation are central to ammonia oxidation (AO) catalysis, an enabling technology to ultimately exploit ammonia (NH ) as an alternative fuel source. While homocoupling of a terminal amide species (M-NH ) to form hydrazine (N H ) has been proposed, well-defined examples are without precedent. Herein, we discuss the generation and electronic structure of a Ni -NH species that undergoes bimolecular coupling to generate a Ni (N H ) complex.
View Article and Find Full Text PDFCGA (Vasostatin-1, VS-1) a N-terminal Chromogranin A (CGA)-derived peptide, has been shown to have a protective effect against TNF-α-induced impairment of endothelial cell integrity. However, the mechanisms of this effect have not yet been clarified. CGA (Chromofungin, CHR) is an important bioactive fragment of CGA.
View Article and Find Full Text PDFTerminal Ni hydrides are proposed intermediates in proton reduction catalyzed by both molecular electrocatalysts and metalloenzymes, but well-defined examples of paramagnetic nickel hydride complexes are largely limited to bridging hydrides. Herein, we report the synthesis of an = 1/2, terminally bound thiolate-Ni-H complex. This species and its terminal hydride ligand in particular have been thoroughly characterized by vibrational and EPR techniques, including pulse EPR studies.
View Article and Find Full Text PDFChem Commun (Camb)
May 2019
A heterobimetallic VFe complex is demonstrated to catalyse hydrazine disproportionation with yields of up to 1073 equivalents of NH3 per catalyst, comparable to the highest turnover known for any molecular catalyst. Notably, the heterobimetallic complex is appreciably more active than monometallic analogues of the V and Fe sites, suggesting that bimetallic cooperativity may facilitate the observed catalysis.
View Article and Find Full Text PDFBelieved to accumulate on the Fe sites of the FeMo-cofactor (FeMoco) of MoFe-nitrogenase under turnover, strongly donating hydrides have been proposed to facilitate N binding to Fe and may also participate in the hydrogen evolution process concomitant to nitrogen fixation. Here, we report the synthesis and characterization of a thiolate-coordinated Fe(H)(N) complex, which releases H upon warming to yield an Fe-N-Fe complex. Bimolecular reductive elimination of H from metal hydrides is pertinent to the hydrogen evolution processes of both enzymes and electrocatalysts, but well-defined examples are uncommon and usually observed from diamagnetic second- and third-row transition metals.
View Article and Find Full Text PDFObjective: Ulinastatin reduces the high permeability of vascular endothelial cells induced by tumor necrosis factor alpha (TNF-α). This study investigated the molecular mechanism behind this effect, with the aim of understanding the action of ulinastatin in sepsis therapy and exploring novel therapeutic strategies for sepsis patients.
Methods: A TNF-α treated human umbilical vein endothelial cell line (EA.
Objective: The objective was to investigate the correlation between single nucleotide polymorphism (SNP) of chromogranin A (CHGA) and prognosis of critically ill patients.
Methods: We screened 357 critically ill patients consecutively admitted to our intensive care unit. The -89/-415/-462 SNP locus in the promoter region and the +9559/+9578/+9590/+9611 SNP locus in exon 7 coding of CHGA were genotyped by polymerase chain reaction and DNA sequencing technology.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue
December 2013
Objective: To explore the role of chromogranin A ( CGA) derived peptide CGA47~ ( Chromfungin, CHR) on septic serum induced high permeability of vascular endothelial cells.
Methods: Human umbilical venous endothelial cell line (EA.hy926 cells) was exposed to CHR, serum of septic shock patient, and tumor necrosis factor-a (TNF-a) respectively.
Concomitant deprotonation and metalation of hexadentate ligand platform (tbs)LH6 ((tbs)LH6 = 1,3,5-C6H9(NHC6H4-o-NHSiMe2(t)Bu)3) with divalent transition metal starting materials Fe2(Mes)4 (Mes = mesityl) or Mn3(Mes)6 in the presence of tetrahydrofuran (THF) resulted in isolation of homotrinuclear complexes ((tbs)L)Fe3(THF) and ((tbs)L)Mn3(THF), respectively. In the absence of coordinating solvent (THF), the deprotonation and metalation exclusively afforded dinuclear complexes of the type ((tbs)LH2)M2 (M = Fe or Mn). The resulting dinuclear species were utilized as synthons to prepare bimetallic trinuclear clusters.
View Article and Find Full Text PDF[Re(bpy-tBu)(CO)4](OTf) (bpy-tBu = 4,4'-di-tert-butyl-2,2'-bipyridine, OTf = trifluoromethanesulfonate) (1) and [Re(bpy)(CO)4](OTf) (bpy = 2,2'-bipyridine) (2) were synthesized and studied as proposed intermediates in the electrocatalytic reduction of carbon dioxide (CO2) by Re(bpy-R)(CO)3X. Both compounds demonstrated increased current responses in cyclic voltammograms under CO2. Complex 1 was also characterized by X-ray crystallography.
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