As a major component of cell membrane lipids, Arachidonic acid (AA), being a major component of the cell membrane lipid content, is mainly metabolized by three kinds of enzymes: cyclooxygenase (COX), ...lipoxygenase (LOX), and cytochrome P450 (CYP450) enzymes. Based on these three metabolic pathways, AA could be converted into various metabolites that trigger different inflammatory responses. In the kidney, prostaglandins (PG), thromboxane (Tx), leukotrienes (LTs) and hydroxyeicosatetraenoic acids (HETEs) are the major metabolites generated from AA. An increased level of prostaglandins (PGs), TxA
and leukotriene B4 (LTB
) results in inflammatory damage to the kidney. Moreover, the LTB
-leukotriene B4 receptor 1 (BLT1) axis participates in the acute kidney injury via mediating the recruitment of renal neutrophils. In addition, AA can regulate renal ion transport through 19-hydroxystilbenetetraenoic acid (19-HETE) and 20-HETE, both of which are produced by cytochrome P450 monooxygenase. Epoxyeicosatrienoic acids (EETs) generated by the CYP450 enzyme also plays a paramount role in the kidney damage during the inflammation process. For example, 14 and 15-EET mitigated ischemia/reperfusion-caused renal tubular epithelial cell damage. Many drug candidates that target the AA metabolism pathways are being developed to treat kidney inflammation. These observations support an extraordinary interest in a wide range of studies on drug interventions aiming to control AA metabolism and kidney inflammation.
Optical diagnosis-based combustion experiments were conducted to investigate the characteristics of cavity assisted hydrogen jet combustion in a supersonic flow with a total pressure of 1.6 MPa, a ...total temperature of 1486 K, and a Mach number of 2.52, simulating flight Mach 6 conditions. A supersonic combustor with a constant cross-sectional area was employed with several cavity configurations, fueling schemes and equivalence ratios. It was found that stable combustion could not be obtained without a cavity, indicating that pure jet-wake stabilized combustion could not be achieved and the cavity acted as a flameholder. Three combustion modes were observed for the cavity assisted hydrogen jet combustion: cavity assisted jet-wake stabilized combustion, cavity shear-layer stabilized combustion, and combined cavity shear-layer/recirculation stabilized combustion. The cavity assisted jet-wake stabilized combustion was observed to be the most unstable mode, accompanied by intermittent blowoff under the present conditions, while the combined cavity shear-layer/recirculation stabilized combustion mode seemed to be the most robust one.
•Combustion modes in a supersonic combustor are investigated experimentally.•Three combustion modes are observed for cavity assisted hydrogen jet combustion.•Cavity assisted jet-wake stabilized combustion is the most unstable mode.•Combined cavity shear-layer/recirculation stabilized combustion is the most robust.
This study investigated the influence of Coronavirus Disease 2019 (COVID-19) on lung function in early convalescence phase.
A retrospective study of COVID-19 patients at the Fifth Affiliated Hospital ...of Sun Yat-sen University were conducted, with serial assessments including lung volumes (TLC), spirometry (FVC, FEV1), lung diffusing capacity for carbon monoxide (DLCO),respiratory muscle strength, 6-min walking distance (6MWD) and high resolution CT being collected at 30 days after discharged.
Fifty-seven patients completed the serial assessments. There were 40 non-severe cases and 17 severe cases. Thirty-one patients (54.3%) had abnormal CT findings. Abnormalities were detected in the pulmonary function tests in 43 (75.4%) of the patients. Six (10.5%), 5(8.7%), 25(43.8%) 7(12.3%), and 30 (52.6%) patients had FVC, FEV1, FEV1/FVC ratio, TLC, and DLCO values less than 80% of predicted values, respectively. 28 (49.1%) and 13 (22.8%) patients had PImax and PEmax values less than 80% of the corresponding predicted values. Compared with non-severe cases, severe patients showed higher incidence of DLCO impairment (75.6%vs42.5%, p = 0.019), higher lung total severity score (TSS) and R20, and significantly lower percentage of predicted TLC and 6MWD. No significant correlation between TSS and pulmonary function parameters was found during follow-up visit.
Impaired diffusing-capacity, lower respiratory muscle strength, and lung imaging abnormalities were detected in more than half of the COVID-19 patients in early convalescence phase. Compared with non-severe cases, severe patients had a higher incidence of DLCO impairment and encountered more TLC decrease and 6MWD decline.
Obesity and hyperlipidemia are the most prevalent independent risk factors of chronic kidney disease (CKD), suggesting that lipid accumulation in the renal parenchyma is detrimental to renal ...function. Non-esterified fatty acids (also known as free fatty acids, FFA) are especially harmful to the kidneys. A concerted, increased FFA uptake due to high fat diets, overexpression of fatty acid uptake systems such as the CD36 scavenger receptor and the fatty acid transport proteins, and a reduced β-oxidation rate underlie the intracellular lipid accumulation in non-adipose tissues. FFAs in excess can damage podocytes, proximal tubular epithelial cells and the tubulointerstitial tissue through various mechanisms, in particular by boosting the production of reactive oxygen species (ROS) and lipid peroxidation, promoting mitochondrial damage and tissue inflammation, which result in glomerular and tubular lesions. Not all lipids are bad for the kidneys: polyunsaturated fatty acids (PUFA) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) seem to help lag the progression of chronic kidney disease (CKD). Lifestyle interventions, especially dietary adjustments, and lipid-lowering drugs can contribute to improve the clinical outcome of patients with CKD.
Functionally graded materials (FGMs) are desirable in a variety of applications. Due to a lack of understanding of design and manufacturing methods, it remains a challenge to engineer FGMs. Gradient ...patterns and performance shown in biological materials present motifs for designing FGMs. The bottom-up characteristic of additive manufacturing (AM) enables unparalleled control over material and structure, making AM a perfect candidate for FGMs. The integration of the two provides an unprecedented opportunity for developing next generation advanced materials. In this review, we firstly detail the biological gradient materials/structures in terms of their functions. Subsequently, the art-of-the-state AM methods for fabricating FGMs are reviewed, with a focus on the technology types of AM that can prepare biomimetic material and structural FGMs, especially emphasizing the multiform gradients induced by processing parameters. Then, the performance and application cases of FGMs created by AM are summarized. Finally, an outlook for further developments of AM technologies towards FGMs is provided.
Combustion oscillations in a supersonic combustor with hydrogen injection upstream of a cavity flameholder are investigated numerically using a hybrid RANS/LES (Reynolds-Averaged ...Navier–Stokes/Large-Eddy Simulation) method acting as a wall-modeled LES. A turbulent boundary layer with thickness of δinf = 2.5 mm is considered and a recycling/rescaling method is adopted to treat the unsteady inflow. The results show that combustion oscillations can mainly be attributed to two mechanisms. One is the unsteady flame spreading from the cavity shear layer to the main stream, which is greatly influenced by the interaction of the jet-with-cavity shear layer. This mechanism leads to relatively low-frequency oscillations that correspond to the cavity-shear layer oscillations. The other is the auto-ignition of the combustible fluid packets formed around the fuel jet accompanied by the generation of the hairpin-like vortices, which leads to relatively high-frequency oscillations that correspond to the jet instabilities.
► Combustion oscillations in a supersonic combustor are investigated numerically. ► One oscillation mechanism is the unsteady flame spreading. ► Another oscillation mechanism is the auto-ignition of combustible fluid packets.
As one of active cooling method, opposing jet shows its advantages on the aerodynamic thermal reduction for hypersonic flight. To accurately predict its thermal protection features, a ...fluid-thermal-structural coupling strategy is adopted for a cone body with opposing jet, with a nose radius of 6 mm and jet radius of 0.6 mm. The related turbulent model and coupling method is validated by comparison of the numerical and experimental results. The interaction among flow, heat transfer, and the structural responds are gained in 60 s flight, and the influence of total pressure ratio of opposing jet (PR) is also discussed. The analysis indicates the necessary of fluid-thermal-structural coupling investigation for the details understanding of thermal protection procedure. The results show that the adoption of opposing jet can decrease the structure temperature and reduce drag obviously, and increase the stress at the tip region meanwhile, but still presents its advantage for its large enough safe factor. Besides, the adoption value of PR should be an integrated consideration of flow, heat transfer, structural response and coolant consume.
High fluorescence quantum yield graphene quantum dots (GQDs) have showed up as a new generation for bioimaging. In this work, luminescent GQDs were prepared by an ameliorative photo-Fenton reaction ...and a subsequent hydrothermal process using graphene oxide sheets as the precursor. The as-prepared GQDs were nanomaterials with size ranging from 2.3 to 6.4 nm and emitted intense green luminescence in water. The fluorescence quantum yield was as high as 24.6% (excited at 340 nm) and the fluorescence was strongest at pH 7. Moreover, the influences of low-concentration (12.5, 25 μg/mL) GQDs on the morphology, viability, membrane integrity, internal cellular reactive oxygen species level and mortality of HeLa cells were relatively weak, and the in vitro imaging demonstrated GQDs were mainly in the cytoplasm region. More strikingly, zebrafish embryos were co-cultured with GQDs for in vivo imaging, and the results of heart rate test showed the intake of small amounts of GQDs brought little harm to the cardiovascular of zebrafish. GQDs with high quantum yield and strong photoluminescence show good biocompatibility, thus they show good promising for cell imaging, biolabeling and other biomedical applications.
Display omitted
•Preparation and characterization of polyurea elastomers containing dynamic disulfide/diselenide bonds.•The feasibility of containing dynamic disulfide bonds/diselenide bonds as ...asphalt modifiers was verified.•Contributions of dynamic disulfide/diselenide bonds to the self-healing capability of asphalt binder were compared.
Adding self-healing materials to asphalt can improve the service life of asphalt pavement. In this research, three kinds of polyurea elastomers (PE) with self-healing properties were prepared: the elastomer containing disulfide bonds (PE-S1) obtained by one-step copolymerization and the elastomers containing disulfide/diselenide bonds (PE-S2/PE-Se) obtained by two-step copolymerization. The three elastomers were used as modifiers to prepare corresponding modified asphalt. Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy demonstrate the successful preparation of the elastomer containing disulfide/diselenide bond. The results of fluorescence microscope and fracture-healing-tensile test demonstrated that elastomers containing dynamic disulfide/diselenide bonds had self-healing capability. Dynamic chemical bonds and synthesis steps had an impact on the thermal stability of the elastomer, but these were not enough to affect the preparation of elastomer modified asphalt. The results of tensile ductility test showed that all three kinds of elastomer modifiers could improve the self-repairing ability of asphalt binder, and the optimum content was 4%. At the same time, there are differences in the self-healing properties of elastomer modified asphalt with different dynamic chemical bonds and synthesis steps. PE-Se elastomer modified asphalt had the better short-term healing capability. PE-S1 elastomer modified asphalt had greater advantages in long-term healing capability.
Display omitted
•Type 2 Diabetes symptoms similar to the manifestations of "Xiao Ke disease" in the TCM classics.•Six Chinese medicinals for classical formula Liuwei Dihuang pills (LWP).•LWP exerts ...therapeutic efficacy on the T2DM symptoms.•Pharmacological mechanism and active compounds of LWP for treating T2DM.
In traditional Chinese medicine (TCM), type 2 diabetes mellitus (T2DM) is regarded as Xiao Ke disease. Liuwei Dihuang pills (LWP), a classical TCM formula, with the function of nourishing kidney yin, has been used for treating Xiao Ke disease in clinic. In this review, we systematically highlighted recent evidence on LWP and T2DM data from clinical and animal studies, summarized the clinical application, pharmacological mechanism and the active compounds of LWP for the treatment of T2DM. This systematic review will provide an insightful understanding of TCM formulas, pharmacological mechanisms, medicinal-disease interactions, and will lay a foundation for the development of new drug therapy for T2DM.
PDF
