Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 8 de 8
Filter
Add more filters










Database
Language
Publication year range
1.
Materials (Basel) ; 16(15)2023 Aug 06.
Article in English | MEDLINE | ID: mdl-37570194

ABSTRACT

The softening-melting properties of mixed ferrous burden made from high-basicity sinter with increased MgO and Al2O3 content and acid pellets was investigated for optimization. The influences of MgO and Al2O3 are discussed with the aid of phase analysis. The results showed that, with decreasing MgO mass%/Al2O3 mass% in mixed burden, all the softening-melting characteristic temperatures decreased, which can be attributed to the low melting temperature and viscosity of the slag caused by MgO and Al2O3. The permeability of the melting zone deteriorated again when MgO mass%/Al2O3 mass% decreased to a certain content. The softening interval widened slightly at first and then narrowed, while the melting interval first increased slightly and then increased greatly later. It can be deduced that the softening properties were improved, but the melting properties were worsened. Under comprehensive consideration of its softening-melting properties, permeability, iron ore reduction and the thermal state of the blast furnace hearth, the optimal softening-melting properties of a mixed ferrous burden with MgO mass%/Al2O3 mass% of 0.82 is optimal.

2.
Sleep Med Rev ; 65: 101663, 2022 10.
Article in English | MEDLINE | ID: mdl-36087456

ABSTRACT

Obstructive sleep apnea (OSA) is an established risk factor for high blood pressure (BP) in adults. However, it remains unclear whether the same association could be found in children and adolescents. Therefore, we conducted a systematic review and meta-analysis of observational studies to evaluate the associations between childhood OSA and BP outcomes. The review protocol was registered in PROSPERO (CRD42021225683). We performed a systematic literature search to identify relevant cross-sectional and longitudinal studies up to July 6, 2021. Of the 4902 identified articles, a total of 12 cross-sectional studies and 2 cohort studies were included in the final analyses. In the cross-sectional analyses, the mean systolic BP (SBP) were significantly higher in children with mild or moderate-to-severe OSA compared to the healthy controls, and these effects were more pronounced during the nighttime. In prospective studies, moderate-to-severe childhood OSA was associated with a risk of elevated SBP in adulthood (Mean difference = 4.02 mm Hg, 95% CI = 1.32 to 6.72). Taken together, our results suggest that moderate-to-severe childhood OSA is associated with a higher risk of adverse SBP outcomes. Early detection and treatment of OSA may promote cardiovascular health in children and adolescents and possibly in future adulthood.


Subject(s)
Hypertension , Sleep Apnea, Obstructive , Adolescent , Adult , Blood Pressure/physiology , Child , Cross-Sectional Studies , Humans , Hypertension/complications , Polysomnography , Prospective Studies
3.
Front Cardiovasc Med ; 9: 930000, 2022.
Article in English | MEDLINE | ID: mdl-36035915

ABSTRACT

The associations between sleep duration and cardiovascular diseases (CVDs) have been explored in many observational studies. However, the causality of sleep duration and many CVDs, such as coronary artery disease (CAD), heart failure (HF), and stroke, remains unclear. In this study, we conducted a systematic meta-review and meta-analysis of the results of observational and Mendelian randomization (MR) studies to examine how sleep duration impacts the risk of CVDs. We searched articles published in English and before 10 September 2021 in PubMed, Web of Science, and Embase. The articles were screened independently by two reviewers to minimize potential bias. We combined the meta-analyses of observational studies and 11 MR studies and summarized evidence of the effect of sleep duration on the risk of CAD, HF, stroke, and cardiovascular and all-cause mortality. Results showed that (a) evidence is accumulating that short sleep duration is a causal risk factor for CAD and HF; (b) abundant evidence from observational studies supports that long sleep duration is associated with the risk of CAD, stroke, and mortality, and long sleep duration has no causal associations with stroke and CAD in the MR studies; the causation of long sleep duration and other CVDs should be further studied; and (c) emerging evidence indicates that an increase in hours of sleep is associated with a decreased risk of CAD. Finally, we discussed the underlying pathophysiological mechanisms underlying short sleep duration and CVDs and suggested that increasing sleep duration benefits cardiovascular health.

4.
Antioxidants (Basel) ; 11(8)2022 Aug 18.
Article in English | MEDLINE | ID: mdl-36009315

ABSTRACT

Cardiovascular diseases (CVD) are leading causes of morbidity and mortality worldwide; therefore, seeking effective therapeutics to reduce the global burden of CVD has become increasingly urgent. Celastrol, a bioactive compound isolated from the roots of the plant Tripterygium wilfordii (TW), has been attracting increasing research attention in recent years, as it exerts cardiovascular treatment benefits targeting both CVD and their associated risk factors. Substantial evidence has revealed a protective role of celastrol against a broad spectrum of CVD including obesity, diabetes, atherosclerosis, cerebrovascular injury, calcific aortic valve disease and heart failure through complicated and interlinked mechanisms such as direct protection against cardiomyocyte hypertrophy and death, and indirect action on oxidation and inflammation. This review will mainly summarize the beneficial effects of celastrol against CVD, largely based on in vitro and in vivo preclinical studies, and the potential underlying mechanisms. We will also briefly discuss celastrol's pharmacokinetic limitations, which hamper its further clinical applications, and prospective future directions.

5.
Eur J Pharmacol ; 924: 174971, 2022 Jun 05.
Article in English | MEDLINE | ID: mdl-35469836

ABSTRACT

Osteoarthritis (OA), a progressive and degenerative joint disease, is characterized by cartilage degradation, synovitis, subchondral bone remodeling and osteophyte formation. Isorhynchophylline (IRN) is an oxindole alkaloid isolated from the traditional Chinese herb Uncaria rhynchophylla. In this study, we evaluated the protective effects of IRN on human OA chondrocytes. IRN treatment dose-dependently decreased the interleukin-1ß (IL-1ß)-induced expressions of nitric oxide (NO; p < 0.001), prostaglandin E2 (PGE2; p < 0.001), tumor necrosis factor alpha (TNF-α; p < 0.001), interleukin-6 (IL-6; p < 0.001), cyclooxygenase-2 (COX-2; p < 0.001) and inducible nitric oxide synthase (iNOS; p < 0.001) in chondrocytes. Meanwhile, the production of metalloproteinase 13 (MMP13; p < 0.001) and a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS5; p < 0.001) was inhibited by IRN treatment. Molecular docking studies revealed that IRN directly interacted with the nuclear factor kappa B (NF-κB) complex, which was associated with a reduced level of NF-κB nuclear translocation and the inhibition of NF-κB signaling activity. Furthermore, administration of IRN generated marked in vivo protective effects during OA development. Collectively, our results demonstrate that IRN may exhibit therapeutic benefits against OA, potentially by ameliorating the inflammative and degenerative progression of OA via inhibiting the NF-κB pathway.


Subject(s)
NF-kappa B , Osteoarthritis , Chondrocytes , Cyclooxygenase 2/metabolism , Dinoprostone/metabolism , Humans , Interleukin-1beta/metabolism , Interleukin-6/metabolism , Molecular Docking Simulation , NF-kappa B/metabolism , Nitric Oxide/metabolism , Osteoarthritis/pathology , Oxindoles/metabolism , Oxindoles/pharmacology , Oxindoles/therapeutic use , Tumor Necrosis Factor-alpha/metabolism , Uncaria
6.
ACS Omega ; 5(41): 26817-26828, 2020 Oct 20.
Article in English | MEDLINE | ID: mdl-33111008

ABSTRACT

In this paper, the influence of Stefan flow on different reactivity coke solution loss reaction (Ccoke + CO2 = 2CO) at different temperatures were analyzed and compared to deeply understand the mechanism of the coke solution loss reaction. Isothermal experiments of carbon dioxide gasification with Coke A (low reactivity), Coke B (medium reactivity), and Coke C (high reactivity), respectively, were carried out at 1100-1300 °C. After calculation, it is concluded that the external diffusion coefficients and the mass transfer coefficients with Stefan flow of three kinds of coke were decreased, and their minimum average deviations with and without Stefan flow were 44.57/43.27/43.23 and 42.57/39.47/39.15%, respectively. As the coke reactivity increased, the diffusion and mass transfer capacity of carbon dioxide with Stefan flow in the boundary layer decreased. The carbon dioxide concentration on the outer surface of three kinds of coke with Stefan flow was less than that without Stefan flow. The influence of Stefan flow on carbon dioxide concentration on the outer surface of coke was increased with the increase of coke reactivity. The area of carbon dioxide concentration region in the three kinds of coke declined after modification, and the deviations of the carbon dioxide concentration region area before and after modification of three kinds of coke ranged from 6.62 to 22.85%, 7.74 to 25.17%, and 8.62 to 26.74%. The influence of Stefan flow on the carbon dioxide concentration region increased as coke reactivity increased.

7.
Org Lett ; 16(6): 1602-5, 2014 Mar 21.
Article in English | MEDLINE | ID: mdl-24593196

ABSTRACT

Aldehydes and primary alcohols can be converted to one-carbon homologated primary, secondary, or tertiary amides in two operational steps. The approach offers several unique features including compatibility with (hetero)aryl, alkyl, alkenyl, and racemizable chiral substrates, the ability to prepare Weinreb amides from aryl and unhindered aliphatic substrates, and the opportunity to employ unprotected amino acids as amine sources in the amidation step.

8.
J Org Chem ; 77(10): 4854-60, 2012 May 18.
Article in English | MEDLINE | ID: mdl-22559051

ABSTRACT

Versatile trichloromethyl carbinols can be prepared in one pot from primary alcohols by treatment with Dess-Martin periodinane (DMP) in CHCl(3) followed by introduction of commercially available 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD). A modification of the method was used to convert chiral primary alcohol (R)-(-)-2,2-dimethyl-1,3-dioxolane-4-methanol to the corresponding trichloromethyl carbinol with complete stereochemical fidelity, despite the reactant proceeding through a base-sensitive aldehyde intermediate.


Subject(s)
Alcohols/chemistry , Aldehydes/chemistry , Dioxolanes/chemistry , Hydrocarbons, Chlorinated/chemistry , Hydrocarbons, Chlorinated/chemical synthesis , Methanol/chemistry , Methanol/chemical synthesis , Molecular Structure , Stereoisomerism
SELECTION OF CITATIONS
SEARCH DETAIL
...