Dysbiosis of gut microbiota plays an important role in cardiovascular diseases but the molecular mechanisms are complex. An association between gut microbiome and the variance in HDL-C (high-density ...lipoprotein-cholesterol) level was suggested in a human study. Besides, dietary fat was shown to increase both HDL-C and LDL-C (low-density lipoprotein-cholesterol) levels. We speculate that certain types of gut bacteria responding to dietary fat may help to regulate HDL-C level and potentially affect atherosclerotic development.
We aimed to investigate whether and how high-fat diet (HFD)-associated gut microbiota regulated HDL-C level.
We found that HFD increased gut flagellated bacteria population in mice. The increase in HDL-C level was adopted by mice receiving fecal microbiome transplantation from HFD-fed mouse donors. HFD led to increased hepatic but not circulating flagellin, and deletion of TLR5 (Toll-like receptor 5), a receptor sensing flagellin, suppressed HFD-stimulated HDL-C and ApoA1 (apolipoprotein A1) levels. Overexpression of TLR5 in the liver of TLR5-knockout mice was able to partially restore the production of ApoA1 and HDL-C levels. Mechanistically, TLR5 activation by flagellin in primary hepatocytes stimulated ApoA1 production through the transcriptional activation responding to the binding of NF-κB (nuclear factor-κB) on
promoter region. Furthermore, oral supplementation of flagellin was able to stimulate hepatic ApoA1 production and HDL-C level and decrease atherosclerotic lesion size in apolipoprotein E-deficient (
) mice without triggering hepatic and systemic inflammation. The stimulation of ApoA1 production was also seen in human ApoA1-transgenic mice treated with oral flagellin.
Our finding suggests that commensal flagellated bacteria in gut can facilitate ApoA1 and HDL-C productions in liver through activation of TLR5 in hepatocytes. Hepatic TLR5 may be a potential drug target to increase ApoA1.
Graphene, whose absorbance is approximately independent of wavelength, allows broadband light-matter interactions with ultrafast responses. The interband optical absorption of graphene can be ...saturated readily under strong excitation, thereby enabling scientists to exploit the photonic properties of graphene to realize ultrafast lasers. The evanescent field interaction scheme of the propagating light with graphene covered on a D-shaped fibre or microfibre has been employed extensively because of the nonblocking configuration. Obviously, most of the fibre surface is unused in these techniques. Here, we exploit a graphene-clad microfibre (GCM) saturable absorber in a mode-locked fibre laser for the generation of ultrafast pulses. The proposed all-surface technique can guarantee a higher efficiency of light-graphene interactions than the aforementioned techniques. Our GCM-based saturable absorber can generate ultrafast optical pulses within 1.5 μm. This saturable absorber is compatible with current fibre lasers and has many merits such as low saturation intensities, ultrafast recovery times, and wide wavelength ranges. The proposed saturable absorber will pave the way for graphene-based wideband photonics.
Safe disposal of nuclear waste is essential to ensure the sustainability of nuclear energy. This is especially true for the volatile radionuclide iodine-129 due to its long half-life (15.7 Ma) and ...high mobility in most disposal environments. The dissolution behaviour of lead vanadium iodoapatite (Pb
5
(VO
4
)
3
I) synthesized to evaluate its possible use for immobilizing iodine-129 was investigated to understand the mechanism by which iodide is released. Experiments using a semi-dynamic method were carried out in cap-sealed Teflon vessels at a constant temperature 90 ± 0.5 °C with a fixed sample surface area-to-solution volume ratio of 16 m
−1
. The leachates were analyzed using inductively coupled plasma mass spectrometry (ICP-MS) and the leached surfaces were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM) and infrared spectroscopy (IR). The results show that lead and vanadium dissolved congruently at a constant rate, while the iodine was initially released at a significantly higher rate than suggested by its stoichiometry with respect to lead and vanadium. The iodine-to-lead molar ratio in the solution gradually decreased over time, but iodine release remained superstoichiometric. The results suggest the release of iodide occurs by an ion-exchange process that is faster than the dissolution rate of the Pb-V-O framework. Analysis of the leached samples shows that the spectroscopic signature of OH groups in the leached samples is consistent with an ion exchange mechanism.
Incongruent release of iodine from iodoapatite (Pb
5
(VO
4
)
3
I) for immobilization of
129
iodine, controlled by exchange of iodide and hydroxide in solution.
This study sought to investigate the impact of pre-existing cognitive impairment on outcomes after transcatheter aortic valve implantation (TAVI). TAVI has been increasingly used in seniors, and ...evidence suggests better outcomes than surgical aortic valve replacement. Although frailty has been shown to be associated with poorer outcomes after TAVI, the effect of pre-existing cognitive impairment on patient outcomes after TAVI remains unclear. We searched the Medline, Embase, Scopus and Cochrane databases until May 14, 2022. The risk of bias was assessed using the Newcastle-Ottawa scale. The primary outcome was short-term (6 months to 1 year) mortality, and secondary outcomes included long-term (1 year to 3 years) mortality, in-hospital mortality, and postoperative delirium. A total of 14 studies with 32,746 patients (5,098 patients with cognitive impairment at baseline, 27,648 without) were included in our meta-analysis. Among studies that reported the raw proportion of patients with mortality of postoperative delirium, cognitive impairment significantly increased mortality (risk ratio 2.10, 95% confidence intervals CIs 1.43 to 3.08, p = 0.0002) and postoperative delirium (risk ratio 2.27, 95% CI 1.76 to 2.93, p <0.0001). Studies which reported the hazards for mortality (pooled hazards ratio 1.97, 95% CI 1.50 to 2.60, p <0.0001) and odds of postoperative delirium (pooled odds ratio 2.40, 95% CI: 1.51 to 3.80, p = 0.0002) yielded results consistent with the primary meta-analysis. In conclusion, pre-existing cognitive impairment is a significant risk factor for poorer outcomes after TAVI and should be carefully considered in this group of patients. Guidelines and future studies should take cognitive impairment into consideration for preoperative risk stratification.
To explore the value of Krüppel-like factor 5 (KLF5), a family member of the zinc finger protein transcription factor, in the diagnosis and prognostic evaluation of hepatocellular carcinoma (HCC).
...Cancerous and non-cancerous tissues were collected from 126 cases after HCC surgery by self-matching method with microarray fabrication. Immunohistochemistry was used to analyze the expression of KLF5, clinicopathological characteristics and prognostic value. The sera of 222 cases with chronic liver disease were collected and their KLF5 levels were quantitatively determined by enzyme-linked immunosorbent assay (ELISA). Simultaneously, 40 normal human sera were used as controls to evaluate the value of abnormal KLF5 in the diagnosis and differentiation of benign and malignant liver diseases. T-test, Z-test and χ (2) test were performed on the data.
The positive expression rate of KLF5 in the HCC group was 95.2% (120/126), which was significantly higher than the non-cancerous group 38.9% (49/126; χ (2) = 14.385,
< 0.0
Seafloor seepage sites along the Vestnesa Ridge off west-Svalbard have been, for decades, a natural laboratory for the studies of fluid flow and gas hydrate dynamics along passive continental ...margins. The lack of ground truth evidence for fluid composition and gas hydrate abundance deep in the sediment sequence however prohibits us from further assessing the current model of pockmark evolution from the region. A MARUM-MeBo 70 drilling cruise in 2016 aims to advance our understanding of the system by recovering sediments tens of meters below seafloor from two active pockmarks along Vestnesa Ridge. We report pore fluid composition data focusing on dissolved chloride, stable isotopes of water (δ18O and δD), and the isotopic composition of dissolved boron (δ11B). From one of the seepage sites, we detect a saline formation water with two layers where gas hydrates were recovered. This saline formation pore fluid is characterized by elevated chloride concentrations (up to 616 mM), high B/Cl ratios (9 × 10−4 mol/mol), high δ18O and δD isotopic signatures (+0.6‰ and +3.8‰, respectively) and low δ11B signatures (+35.0‰), which collectively hint to a high temperature modification at great depths. Based on the dissolved chloride concentration profiles, we estimated up to 47% of pore space occupied by gas hydrate in the sediments shallower than 11.5 mbsf. The observation of bubble fabric in the recovered gas hydrates suggests formation during past periods of intensive gaseous methane seepage. The presence of these gas hydrates without associated positive anomalies in dissolved chloride concentrations however suggests that the decomposition of gas hydrate is as fast as its formation. Such a state of gas hydrates can be attributed to a relatively low methane supply transported by the saline formation water at present. Our findings based on pore fluid composition corroborate previous inferences along Vestnesa Ridge that fluids sustaining seepage have migrated from great depths and that the variable gaseous and aqueous phases through the gas hydrate stability zone control the distributions of authigenic carbonates and gas hydrates.
•A saline formation fluid originated from great depths was documented.•Gas hydrates are currently at a dynamic equilibrium due to the low methane flux.•Fluids were diverted by the buried seep carbonates in Lunde pockmark.
As the importance of non-tailpipe particles (NTP) over tailpipe emissions from urban traffic has been increasing, there is a need to evaluate NTP contributions to ambient particulate matter (PM) ...using representative source profiles. The Brake and Tire Wear Study conducted in Los Angeles, California in the winter of 2020 collected 64 PM2.5 and 64 PM10 samples from 32 pairs of downwind-upwind measurements at two near-road locations (I-5 in Anaheim and I-710 in Long Beach). These samples were characterized for inorganic and organic markers and, along with locally-developed brake wear, tire wear, and road dust source profiles, subject to source apportionment using the effective-variance chemical mass balance (EV-CMB) model. Model results highlighted the dominance of resuspended dust in both PM2.5 (23–33%) and PM10 (32–53%). Brake and tire wear contributed more to PM2.5 than tailpipe exhausts (diesel + gasoline) for I-5 (29–30% vs. 19–21%) while they were comparable for I-710 (15–17% vs. 15–19%). For PM10, the brake and tire wear contributions were 2–3 times the exhaust contributions. Different fleet compositions on and near I-5 and I-710 appeared to influence the relative importance of NTP and exhaust sources. The downwind-upwind differences in source contributions were often insignificant, consistent with small and/or nearly equal impacts of adjacent highway traffic emissions on the downwind and upwind sites. The utility of sole markers, such as barium and zinc, to predict brake and tire wear abundances in ambient PM is evaluated.
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•Near-road PM10 and PM2.5 samples were dominated by resuspended dust.•Brake and tire wear contributed similarly to or more than tailpipe exhaust in PM2.5•Brake and tire wear contributions were 2–3 times the exhaust contributions in PM10.•Barium may serve as a unique marker for brake wear particles in Los Angeles.
Particulate Matter (PM) concentrations near highways are influenced by vehicle tailpipe and non-tailpipe emissions, other emission sources, and urban background aerosols. This study collected PM2.5 ...and PM10 filter samples near two southern California highways (I-5 and I-710) over two weeks in winter 2020. Samples were analyzed for chemical source markers. Mean PM2.5 and PM10 concentrations were approximately 10–15 and 30 μg/m3, respectively. Organic matter, mineral dust, and elemental carbon (EC) were the most abundant PM components. EC and polycyclic aromatic hydrocarbons at I-710 were 19–26% and 47% higher than those at the I-5 sites, respectively, likely due to a larger proportion of diesel vehicles. High correlations were found for elements with common sources, such as markers for brake wear (e.g., Fe, Ba, Cu, and Zr) and road dust (e.g., Al, Si, Ca, and Mn). Based on rubber abundances, the contributions of tire tread particles to PM2.5 and PM10 mass were approximately 8.0% at I-5 and 5.5% at I-710. Two different tire brands showed significantly different Si, Zn, carbon, and natural rubber abundances.
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