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1.
Anal Chem ; 96(5): 2206-2216, 2024 02 06.
Article in English | MEDLINE | ID: mdl-38253323

ABSTRACT

Gut microbiota, widely populating the mammalian gastrointestinal tract, plays an important role in regulating diverse pathophysiological processes by producing bioactive molecules. Extensive detection of these molecules contributes to probing microbiota function but is limited by insufficient identification of existing analytical methods. In this study, a systematic strategy was proposed to detect and annotate gut microbiota-related metabolites on a large scale. A pentafluorophenyl (PFP) column-based liquid chromatography-high-resolution mass spectrometry (LC-HRMS) method was first developed for high-coverage analysis of gut microbiota-related metabolites, which was verified to be stable and robust with a wide linearity range, high sensitivity, satisfactory recovery, and repeatability. Then, an informative database integrating 968 knowledge-based microbiota-related metabolites and 282 sample-sourced ones defined by germ-free (GF)/antibiotic-treated (ABX) models was constructed and subsequently used for targeted extraction and annotation in biological samples. Using pooled feces, plasma, and urine of mice for demonstration application, 672 microbiota-related metabolites were annotated, including 21% neglected by routine nontargeted peak detection. This strategy serves as a useful tool for the comprehensive capture of the intestinal flora metabolome, contributing to our deeper understanding of microbe-host interactions.


Subject(s)
Gastrointestinal Microbiome , Metabolomics , Mice , Animals , Metabolomics/methods , Metabolome , Mass Spectrometry/methods , Chromatography, Liquid/methods , Mammals
2.
Small ; 20(16): e2306750, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38044278

ABSTRACT

Thermal interface materials (TIMs) are in desperate desire with the development of the modern electronic industry. An excellent TIM needs desired comprehensive properties including but not limited to high thermal conductivity, low Yong's modulus, lightweight, as well as low price. However, as is typically the case, those properties are naturally contradictory. To tackle such dilemmas, a strategy of construction high-performance TIM inspired by alveoli is proposed. The material design includes the self-alignment of graphite into 3D interconnected thermally conductive networks by polydimethylsiloxane beads (PBs) -the alveoli; and a small amount of liquid metal (LM) - capillary networks bridging the PBs and graphite network. Through the delicate structural regulation and the synergistic effect of the LM and solid graphite filler, superb thermal conductivity (9.98 ± 0.34 W m-1 K-1) can be achieved. The light emitting diode (LED) application and their performance in the central processing unit (CPU) heat dispersion manifest the TIM developed in the work has stable thermal conductivity for long-term applications. The thermally conductive, soft, and lightweight composites are believed to be high-performance silicone bases TIMs for advanced electronics.

3.
Acta Pharmacol Sin ; 45(3): 619-632, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37848553

ABSTRACT

N6-methyladenosine (m6A) modification is a prevalent RNA epigenetic modification, which plays a crucial role in tumor progression including metastasis. Isothiocyanates (ITCs) are natural compounds and inhibit the tumorigenesis of various cancers. Our previous studies show that ITCs inhibit the proliferation and metastasis of non-small cell lung cancer (NSCLC) cells, and have synergistic effects with chemotherapy drugs. In this study, we investigated the molecular mechanisms underlying the inhibitory effects of ITCs on cancer cell metastasis. We showed that phenethyl isothiocyanate (PEITC) dose-dependently inhibited the cell viability of both NSCLC cell lines H1299 and H226 with IC50 values of 17.6 and 15.2 µM, respectively. Furthermore, PEITC dose-dependently inhibited the invasion and migration of H1299 and H226 cells. We demonstrated that PEITC treatment dose-dependently increased m6A methylation levels and inhibited the expression of the m6A demethylase fat mass and obesity-associated protein (FTO) in H1299 and H226 cells. Knockdown of FTO significantly increased m6A methylation in H1299 and H226 cells, impaired their abilities of invasion and migration in vitro, and enhanced the inhibition of PEITC on tumor growth in vivo. Overexpression of FTO promoted the migration of NSCLC cells, and also mitigated the inhibitory effect of PEITC on migration of NSCLC cells. Furthermore, we found that FTO regulated the mRNA m6A modification of a transcriptional co-repressor Transducin-Like Enhancer of split-1 (TLE1) and further affected its stability and expression. TCGA database analysis revealed TLE1 was upregulated in NSCLC tissues compared to normal tissues, which might be correlated with the metastasis status. Moreover, we showed that PEITC suppressed the migration of NSCLC cells by inhibiting TLE1 expression and downstream Akt/NF-κB pathway. This study reveals a novel mechanism underlying ITC's inhibitory effect on metastasis of lung cancer cells, and provided valuable information for developing new therapeutics for lung cancer by targeting m6A methylation.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Humans , Carcinoma, Non-Small-Cell Lung/metabolism , Lung Neoplasms/pathology , Cell Movement , Isothiocyanates/pharmacology , Isothiocyanates/therapeutic use , Cell Line, Tumor , Co-Repressor Proteins/pharmacology , Alpha-Ketoglutarate-Dependent Dioxygenase FTO/genetics
4.
Anal Chem ; 94(48): 16604-16613, 2022 12 06.
Article in English | MEDLINE | ID: mdl-36472119

ABSTRACT

Glycosides are a large family of secondary metabolites in plants, which play a critical role in plant growth and development. Due to the complexity and diversity in structures and the limited availability of authentic standards, comprehensive annotation of the glycosides remains a great challenge. In this study, using maize as an example, a deep annotation method of glycosides was proposed based on untargeted liquid chromatography-high-resolution tandem mass spectrometry metabolomics analysis. First, knowledge-based in silico aglycone and glycosyl/acyl-glycosyl libraries were built. A total of 1240 known and potential aglycones from databases and literature were recorded. Next, the MS parameters beneficial to aglycone ion-rich MS/MS were explored using 1782 high-resolution MS/MS spectra of glycosides from the MassBank of North America (MoNA) and confirmed by 52 authentic glycoside standards. Then, screening rules for aglycon ions in MS/MS were recommended. Glycoside candidates were further filtered by MS/MS-based chemical classification and MS/MS similarity of aglycon-glycoside pairs. Finally, the glycosylation sites of flavonoid mono-O-glycosides were recommended by characteristic fragmentation patterns. The developed method was validated using glycosides and nonglycosides from the MoNA library. The annotation accuracy rates were 96.8, 94.9, and 98.0% in negative ion mode (ESI-), positive ion mode (ESI+), and the combined ESI- & ESI+, respectively. The annotation specificity was 99.6% (ESI-), 99.6% (ESI+), and 99.2% (ESI- & ESI+). A total of 274 glycosides (including 34 acyl-glycosides) were tentatively annotated in maize by the developed method. The method enables effective and reliable annotation for plant glycosides.


Subject(s)
Spectrometry, Mass, Electrospray Ionization , Tandem Mass Spectrometry , Tandem Mass Spectrometry/methods , Spectrometry, Mass, Electrospray Ionization/methods , Chromatography, Liquid/methods , Glycosides/analysis , Plant Extracts/chemistry , Metabolomics , Chromatography, High Pressure Liquid/methods
5.
Ecotoxicol Environ Saf ; 247: 114209, 2022 Dec 01.
Article in English | MEDLINE | ID: mdl-36308880

ABSTRACT

BACKGROUND: Metal exposure were assumed to be closely related with declined renal function, but the conclusions were controversial. We employed diverse statistical models and assessed the association between metal mixture exposure and mild renal impairment. METHODS: A total of 13 plasma metals were measured in 896 general population from Southern China. Subjects with estimated glomerular filtration rate within 60-89 ml/min/1.73 m2 and urinary albumin-creatinine ratio <30 mg/g creatinine were defined as mild renal impairment (MRI). RESULTS: About 31.47 % participants showed MRI. In the multivariate logistic regression models, compared with the first quartile, high levels of arsenic and molybdenum (the fourth quartile) were both associated with MRI, and the ORs (95 % CI) were 1.68 (1.05, 2.68) and 2.21 (1.40, 3.48), respectively. Their predominant roles were identified by the weighted quantile regression (WQS). Besides, restricted cubic spline analysis verified the relationship between molybdenum level and increased MRI risk in a linear and dose-response manner. CONCLUSION: High levels of arsenic and molybdenum might be independent risk factors of MRI, and they showed combined effect. Our findings might provide vigorous evidence in preventing mild decline in renal function.


Subject(s)
Arsenic , Humans , Molybdenum , Creatinine , Metals , Glomerular Filtration Rate , China/epidemiology
6.
Anal Chem ; 93(31): 10916-10924, 2021 08 10.
Article in English | MEDLINE | ID: mdl-34328315

ABSTRACT

From microbes to human beings, nontargeted metabolic profiling by liquid chromatography (LC)-mass spectrometry (MS) has been commonly used to investigate metabolic alterations. Still, a major challenge is the annotation of metabolites from thousands of detected features. The aim of our research was to go beyond coverage of metabolite annotation in common nontargeted metabolomics studies by an integrated multistep strategy applying data-dependent acquisition (DDA)-based ultrahigh-performance liquid chromatography (UHPLC)-high-resolution mass spectrometry (HRMS) analysis followed by comprehensive neutral loss matches for characteristic metabolite modifications and database searches in a successive manner. Using pooled human urine as a model sample for method establishment, we found 22% of the detected compounds having modifying structures. Major types of metabolite modifications in urine were glucuronidation (33%), sulfation (20%), and acetylation (6%). Among the 383 annotated metabolites, 100 were confirmed by standard compounds and 50 modified metabolites not present in common databases such as human metabolite database (HMDB) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were structurally elucidated. Practicability was tested by the investigation of urines from pregnant women diagnosed with gestational diabetes mellitus vs healthy controls. Overall, 83 differential metabolites were annotated and 67% of them were modified metabolites including five previously unreported compounds. To conclude, the systematic modifying group-assisted strategy can be taken as a useful tool to extend the number of annotated metabolites in biological and biomedical nontargeted studies.


Subject(s)
Metabolomics , Chromatography, High Pressure Liquid , Chromatography, Liquid , Databases, Factual , Female , Humans , Mass Spectrometry , Pregnancy
7.
Macromol Rapid Commun ; 42(5): e2000375, 2021 Mar.
Article in English | MEDLINE | ID: mdl-32794287

ABSTRACT

Most silicone elastomers are thermosets. As a response to the new paradigm of polymer recyclability, the development of silicone elastomers that can be reversibly and repeatedly cured and uncrosslinked using redox conditions is reported. Thiopropyl-modified silicones are oxidized to elastomers with disulfide crosslinks using the organosoluble oxidant PhI(OAc)2 . As with any elastomer, mechanical properties can be tuned by varying crosslink density. Thermal stabilities in air show that the products are comparable to traditional silicone thermosets, with degradation only starting over 300 °C. Uncrosslinking back to the same thiopropyl-modified silicones involves reductive S-S bridge cleavage using a Piers-Rubinsztajn reaction with hydrosilanes catalyzed by B(C6 F5 )3 ; HSiMe2 OSiMe3 is identified as a convenient reducing agent. The initially formed silicone-(CH2 )3 S-SiMe2 OSiMe3 products need deprotection with water in isopropanol/water to completely regenerate the thiopropylsilicones. This oxidation/reduction crosslinking/uncrosslinking cycle is practiced thrice, with a yield of 89% per cycle, with essentially no change in the Young's moduli of the elastomers, or 1 H NMR spectra of the uncrosslinked fluids after reduction. Further oxidation of disulfide groups on the elastomer surface permanently and significantly improved water wettability.


Subject(s)
Elastomers , Silicone Elastomers , Oxidation-Reduction , Polymers , Wettability
8.
Curr Heart Fail Rep ; 18(5): 253-263, 2021 10.
Article in English | MEDLINE | ID: mdl-34427881

ABSTRACT

PURPOSE OF REVIEW: With recent advances in the pharmacological management of type 2 diabetes mellitus (T2DM), there is a growing need to understand which patients optimally benefit from these novel therapies. Various clinical clustering methodologies have emerged that utilise data-agnostic strategies to categorise patients that have similar clinical characteristics and outcomes; broadly, this characterisation is termed phenotyping. In patients with T2DM, we aimed to describe patient characteristics from phenotype studies, their cardiovascular risk profiles and the impact of antihyperglycemic treatment. RECENT FINDINGS: Numerous phenotypic studies have been undertaken that have utilised a combination of clinical, biochemical, imaging and genetic variables. Each of these has produced phenotypes that display a spectrum of cardiovascular risk. Studies that aimed to describe pathophysiological phenotypes generally identified five phenotypes: autoimmune phenotype, insulin-related phenotypes (including permutations of insulin deficiency and resistance), obesity phenotype, ageing phenotype, and a sex-related phenotype. Studies examining risk profiles have demonstrated that across such phenotypes there is a spectrum of risk for diabetic complications. Few studies have examined treatment effects across these phenotypes, and thus provide little insights towards making phenotype-guided treatment decisions Clustering analyses in patients with T2DM have identified distinct phenotypes with unique risk profiles. Further studies are needed that harness the use of clinical, biochemical, imaging and genetic data to explore therapeutic heterogeneity and response to antihyperglycemic treatment across the spectrum of patient phenotypes.


Subject(s)
Diabetes Mellitus, Type 2 , Heart Failure , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/epidemiology , Humans , Hypoglycemic Agents/therapeutic use , Insulin , Phenotype
9.
World J Microbiol Biotechnol ; 37(4): 71, 2021 Mar 25.
Article in English | MEDLINE | ID: mdl-33763773

ABSTRACT

Extracting value-added products from microorganisms is an important research focus for the future. Among the many extraction methods, ultrasound-assisted extraction (UAE) has attracted more attention owing to its advantages in reducing working time, increasing yield, and improving the quality of the extract. This review summarizes the use of UAE value-added products from microorganisms, with the main extracted substances are pigments, lipids, polysaccharides, and proteins. In addition, this work also summarizes the mechanism of UAE and highlights the factors that affect UAE operation, such as ultrasonic power intensity or power density, operation mode, and energy consumption, which need to be considered. All extraction products from microorganisms showed that UAE can effectively improve the extraction yields of value-added products. It also highlights the existing problems of the technology and possible future prospects. In general, the UAE of value-added substances from microorganisms is feasible and has the potential for development.


Subject(s)
Chemical Fractionation/methods , Ultrasonics , Bacteria , Biological Products/chemistry , Biological Products/isolation & purification , Fungi , Lipids/isolation & purification , Microalgae , Pigments, Biological/isolation & purification , Plants , Polysaccharides/isolation & purification , Proteins/isolation & purification , Ultrasonic Waves
10.
J Am Chem Soc ; 141(32): 12707-12716, 2019 08 14.
Article in English | MEDLINE | ID: mdl-31319035

ABSTRACT

Switchable selective hydrogenation among the groups in multifunctional compounds is challenging because selective hydrogenation is of great interest in the synthesis of fine chemicals and pharmaceuticals as a result of the importance of key intermediates. Herein, we report a new approach to highly selectively (>99%) reducing C═X (X = O, N) over the thermodynamically more favorable nitro groups locating the substrate in a metal-organic capsule containing NADH active sites. Within the capsule, the NADH active sites reduce the double bonds via a typical 2e- hydride transfer hydrogenation, and the formed excited-state NAD+ mimics oxidize the reductant via two consecutive 1e- processes to regenerate the NADH active sites under illumination. Outside the capsule, nitro groups are highly selectively reduced through a typical 1e- hydrogenation. By combining photoinduced 1e- transfer regeneration outside the cage, both 1e- and 2e- hydrogenation can be switched controllably by varying the concentrations of the substrates and the redox potential of electron donors. This promising alternative approach, which could proceed under mild reaction conditions and use easy-to-handle hydrogen donors with enhanced high selectivity toward different groups, is based on the localization and differentiation of the 2e- and 1e- hydrogenation pathways inside and outside the capsules, provides a deep comprehension of photocatalytic microscopic reaction processes, and will allow the design and optimization of catalysts. We demonstrate the advantage of this method over typical hydrogenation that involves specific activation via well-modified catalytic sites and present results on the high, well-controlled, and switchable selectivity for the hydrogenation of a variety of substituted and bifunctional aldehydes, ketones, and imines.

11.
Molecules ; 24(22)2019 Nov 15.
Article in English | MEDLINE | ID: mdl-31731621

ABSTRACT

Low molecular weight, highly crosslinked silicone resins are widely used as reinforcing agents for highly transparent elastomers and adhesion/tack promoters in gels. The resins are complex mixtures and their structure / property relationships are ill defined. We report the synthesis of a library of 2, 3 and 4-fold hyperbranched polymeric oils that are comprised of linear, lightly branched or highly branched dendronic structures. Rheological examination of the fluids and tack measurements of gels filled with 10, 25 or 50% dendronic oils were made. Viscosity of the hyperbranched oils themselves was related to molecular weight, but more significantly to branch density. The properties are driven by chain entanglement. When cured into a silicone gel, less densely branched materials were more effective in improving tack than either linear oils or Me3SiO-rich, very highly branched oils of comparable molecular weight, because the latter oils underwent phase separation.


Subject(s)
Silicone Elastomers/chemistry , Silicone Elastomers/chemical synthesis , Silicone Oils/chemistry , Silicone Oils/chemical synthesis , Molecular Weight , Viscosity
12.
Cell Physiol Biochem ; 41(5): 2004-2015, 2017.
Article in English | MEDLINE | ID: mdl-28420000

ABSTRACT

BACKGROUND/AIMS: Flavonol (-)-epicatechin (EPI) is present in high amounts in cocoa and tea products, and has been shown to exert beneficial effects on the cardiovascular system. However, the precise mechanism of EPI on cardiomyocyte hypertrophy has not yet been determined. In this study, we examined whether EPI could inhibit cardiac hypertrophy. METHODS: We utilised cultured neonatal mouse cardiomyocytes and mice for immunofluorescence, immunochemistry, qRT-PCR, and western blot analyses. RESULTS: 1µM EPI significantly inhibited 1µM angiotensin II (Ang II)-induced increase of cardiomyocyte size, as well as the mRNA and protein levels of ANP, BNP and ß-MHC in vitro. The effects of EPI were accompanied with an up-regulation of SP1 and SIRT1, and were abolished by SP1 inhibition. Up-regulation of SP1 could block Ang II-induced increase in cardiomyocyte size, as well as the mRNA and protein levels of ANP, BNP and ß-MHC, and increase the protein levels of SIRT1 in vitro. Moreover, 1 mg/kg body weight/day EPI significantly inhibited mouse cardiac hypertrophy induced by Ang II, which could be eliminated by SP1 inhibition in vivo. CONCLUSION: Our data indicated that EPI inhibited AngII-induced cardiac hypertrophy by activating the SP1/SIRT1 signaling pathway.


Subject(s)
Angiotensin II/adverse effects , Cardiomegaly , Catechin/pharmacology , Myocytes, Cardiac/metabolism , Signal Transduction/drug effects , Sirtuin 1/metabolism , Sp1 Transcription Factor/metabolism , Angiotensin II/pharmacology , Animals , Cardiomegaly/chemically induced , Cardiomegaly/drug therapy , Cardiomegaly/metabolism , Cardiomegaly/pathology , Mice , Myocytes, Cardiac/pathology
13.
J Biochem Mol Toxicol ; 31(11)2017 Nov.
Article in English | MEDLINE | ID: mdl-28768059

ABSTRACT

(-)-Epicatechin (EPI) has beneficial effects on the cardiovascular disease. The human ether-a-go-go-related gene (HERG) potassium channel is crucial for repolarization of cardiac action potential. Dysfunction of the HERG channel can cause long QT syndrome type 2 (LQT2). Arsenic trioxide (As2 O3 ) has shown efficacy in the treatment of acute promyelocytic leukemia. However, As2 O3 can induce the deficiency of HERG channel and cause LQT2. In this study, we examined whether EPI could rescue the As2 O3 -induced HERG channel deficiency. We found that 3 µM EPI obviously increased protein expression and current of HERG channel. EPI was able to recover the protein expression and current of HERG channel disrupted by As2 O3 . EPI was able to increase the expression of SP1 protein and recover the expression of SP1 protein disrupted by As2 O3 . In addition, EPI significantly shortened action potential duration prolonged by As2 O3 . Our data suggest that EPI rescues As2 O3 -induced HERG channel deficiency through upregulating SP1 expression.


Subject(s)
Arsenicals/adverse effects , Catechin/pharmacology , ERG1 Potassium Channel/metabolism , Myocytes, Cardiac/drug effects , Oxides/adverse effects , Sp1 Transcription Factor/metabolism , Action Potentials/drug effects , Animals , Arsenic Trioxide , Cells, Cultured , ERG1 Potassium Channel/genetics , HEK293 Cells , Humans , Kinetics , Myocytes, Cardiac/metabolism , Patch-Clamp Techniques , Rats, Sprague-Dawley
14.
Perit Dial Int ; : 8968608241237400, 2024 Mar 27.
Article in English | MEDLINE | ID: mdl-38532707

ABSTRACT

Effective treatment of infections is a growing challenge owing to antimicrobial resistance. Peritoneal dialysis (PD) patients experience more frequent hospitalisations than the general population and have greater exposure to antibiotics, making them particularly vulnerable to this threat. Over the last decade, we have noted a surge in cases of complicated peritoneal dialysis-associated peritonitis (PD peritonitis) caused by antimicrobial-resistant organisms, including extended-spectrum beta-lactamase (ESBL), AmpC beta-lactamase-producing Enterobacterales, Pseudomonas aeruginosa and fungi. Practitioners must be alert to these organisms, seek early recognition of these resistance patterns and make timely adjustments in order to avoid delay in treatment that may increase risk of PD catheter removal and technique failure. We present a case of successful treatment of ESBL peritonitis, highlight its challenges, while providing guidance on management of other unusual and complicated PD peritonitis.

15.
Can J Kidney Health Dis ; 10: 20543581221150590, 2023.
Article in English | MEDLINE | ID: mdl-36704235

ABSTRACT

Volume overload in peritoneal dialysis (PD) is common and associated with significant morbidity and mortality. If left untreated, it can result in premature technique failure in patients receiving PD. Practitioners should be aware of common causes and formulate a stepwise approach in the management of volume overload.


La surcharge volumique est fréquente chez les patients traités par dialyse péritonéale (DP) et elle est associée à davantage de morbidité et de mortalité. Une surcharge volumique non traitée peut entraîner une défaillance technique prématurée chez les patients sous dialyse péritonéale. Il est important que les praticiens connaissent les causes communes de la surcharge volumique et qu'une approche par étapes soit formulée pour sa prise en charge.

16.
J Mol Histol ; 54(6): 655-664, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37759133

ABSTRACT

Sepsis is a serious inflammatory disease caused by bacterial infection. Cardiovascular dysfunction and remodeling are serious complications of sepsis, which can significantly affect sepsis patients' mortality. Delta-like homologue 1 (DLK1) has been reported could inhibit cardiac myofibroblast differentiation. However, the function of DLK1 in sepsis is unknown. In the present study, the DLK1 expression was first identified based on the online dataset GSE79962 analysis and cecal ligation and puncture (CLP)-induced sepsis mouse model. DLK1 expression was significantly reduced in septic heart tissues. In septic mouse heart, CLP operation decreased the fractional shortening (EF) (%) and ejection fraction (FS) (%) and caused significant edema, disordered myofilament arrangement, and degradation and necrosis in myocardial cells; CLP operation also increased collagen deposition and elevated the protein levels of fibrotic markers (α-SMA and F-actin). DLK1 overexpression in septic mice could effectively increase EF (%) and FS (%), attenuate CLP-caused ECM degradation and deposition and partially inhibit the CLP-induced TGF-ß1/Smad signaling activation. In conclusion, DLK1 expression was poorly expressed in the CLP-induced septic mouse heart. DLK1 overexpression partially alleviated sepsis-induced cardiac dysfunction and fibrosis, with the involvement of the TGF-ß1/Smad3 signaling pathway and MMPs.


Subject(s)
Heart Diseases , Sepsis , Humans , Animals , Mice , Transforming Growth Factor beta1/metabolism , Signal Transduction/physiology , Sepsis/complications , Sepsis/metabolism , Fibrosis , Calcium-Binding Proteins/metabolism , Membrane Proteins/metabolism
17.
ACS Appl Mater Interfaces ; 15(34): 41043-41054, 2023 Aug 30.
Article in English | MEDLINE | ID: mdl-37590910

ABSTRACT

The development of high-performance thermally conductive interface materials is the key to unlocking the serious bottleneck of modern microelectronic technology through enhanced heat dispersion. Existing methods that utilize silicone composites rely either on loading large doses of randomly distributed thermal conductive fillers or on filling prealigned thermal conductive scaffolds with liquid silicone precursors. Both approaches suffer from several limitations in terms of physical traits and processability. We describe an alternative approach in which malleable silicone matrices, based on the dynamic cyclic disulfide nature cross-linker (α-lipoic acid), are readily prepared using ring-opening polymerization. The mechanical properties of the resultant dynamic silicone matrix are readily tunable. Stress-dependent depolymerization of the disulfide network demonstrates the ability to reprocess the silicone elastomer matrix, which allows for the fabrication of highly efficient thermal conductive composites with a 3D interconnecting, thermally conductive network (3D-graphite/MxBy composites) via in situ methods. Applications of the composites as thermal dispersion interface materials are demonstrated by LEDs and CPUs, suggesting great potential in advanced electronics.

18.
ACS Omega ; 8(40): 36986-36998, 2023 Oct 10.
Article in English | MEDLINE | ID: mdl-37841137

ABSTRACT

This study aims to evaluate the dust removal efficiency and working conditions of a filter separator through a pressure drop under various operating conditions. Typical horizontal filter separators in natural gas stations were taken as the research objects, and the computational fluid dynamics method was first attempted to investigate the static and dynamic characteristics of the pressure drop and the dust removal efficiency under different operating times and pressures. Then, the simulated results were compared with those obtained from online dust detection. At a constant standard flow rate, the detected pressure drop deviated from the fitted optimal quadratic curve with an increase in the operation duration of the filter separator, and the dust removal efficiency also tended to decline. The declining trend was particularly faster at lower operating pressures caused by the fast air flow, which leads to more coalesced particles flowing out and increases the dust concentration downstream. A higher initial pressure drop of the filter separator was also maintained at a low operating pressure. The dust removal efficiency rapidly decreased at a higher throughput load, and the decreasing rate became moderate at a lower input load. An optimum operating throughput of the filter was obtained when the input load varied in the range of 100 × 104-270 × 104 Nm3/d. Good agreement was achieved between the simulated and experimental dust removal efficiency, and the relative errors are within ±20%. Both methods applied in this work were verified to have high accuracy and reliability through the actual on-site amount of dust captured.

19.
Environ Pollut ; 331(Pt 2): 121914, 2023 Aug 15.
Article in English | MEDLINE | ID: mdl-37257806

ABSTRACT

Humans are at risk of exogenous exposure to exogenous chemicals. Challenges exist for the comprehensive monitoring of residues with different physical and chemical properties in serum. Here, an on-line two-dimensional liquid chromatography (2D-LC) - high resolution mass spectrometry system (HRMS) was developed, expanding the range of the partition coefficient in octanol/water of the residue analysis from -8 to 12. A high-coverage serum residue screening strategy was further designed by integrating 2D-LC system with HRMS full MS/data independent acquisition and automatic spectral library searching. This strategy enables to simultaneously screen 1210 pesticides, veterinary/human drugs, other chemical pollutants and their metabolites in serum with a single analysis. Method validation showed 92% and 81% of 1022 residues spiked in serum could be detected at 50 ng/mL and 5 ng/mL, respectively. The developed method was applied to the analysis of 24 separately pooled serum samples, 58 suspect residues were found, some of them were detected at high frequencies over than 50%. Among them, 4,6-Dinitro-O-cresol and probable carcinogenic folpet are highly toxic, and cimaterol is banned in China. Collectively, this study developed a 2D-LC-HRMS -based screening strategy for screening pesticides, veterinary/human drugs, and other chemical pollutants in serum, it is helpful for studying the effect of exogenous exposures on human health.


Subject(s)
Environmental Pollutants , Pesticides , Humans , Chromatography, Liquid/methods , Mass Spectrometry/methods , Pesticides/analysis , Water , Environmental Pollutants/analysis
20.
Int J Biol Sci ; 19(5): 1616-1632, 2023.
Article in English | MEDLINE | ID: mdl-37056933

ABSTRACT

Cancer progression depends on the communication between tumor cells and tumor microenvironment. Cancer-associated fibroblasts (CAFs) are a major component of stromal cells. CAFs promote cancer metastasis; however, it has not been evaluated whether N6-methyladenosine (m6A) modification is responsible for CAFs' role in metastasis. In the present study, we found that CAFs promoted migration and invasion of non-small cell lung cancer (NSCLC) cells by elevating m6A modification in NSCLC cells. Methyltransferase-like 3 (METTL3) in NSCLC cells mediated CAFs' effect on m6A modification, and was regulated by CAFs-secreted vascular endothelial growth factor A (VEGFA). METTL3 knockdown in NSCLC cells dramatically inhibited cell migration and invasion, and suppressed tumor growth in vivo. Database analysis revealed that METTL3 was associated with poor prognosis of lung cancer. The mechanism study showed that METTL3 increased m6A level of RAC3 mRNA, resulting in increased stability and translation of RAC3 mRNA. RAC3 was responsible for the CAFs' promoting effect on cell migration via the AKT/NF-κB pathway. This study established a CAF-METTL3-RAC3 m6A modification-dependent regulation system in NSCLC metastasis, suggesting potential candidates for metastasis treatment.


Subject(s)
Cancer-Associated Fibroblasts , Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Humans , Cancer-Associated Fibroblasts/metabolism , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/metabolism , Lung Neoplasms/metabolism , Methyltransferases/genetics , Methyltransferases/metabolism , rac GTP-Binding Proteins/metabolism , RNA, Messenger/metabolism , Tumor Microenvironment , Vascular Endothelial Growth Factor A/metabolism
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