Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 10.512
Filtrar
1.
Expert Rev Mol Diagn ; : 1-10, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34196586

RESUMO

Objective: Associations between gene mutations and metastasis in gastric cancer (GC) remain contradictory, resulting in the inaccurate estimation of the magnitude of the risk associated with specific genotypes.Methods: In this study, we first screened out four key driver genes (TP53, PIK3CA, APC and ARID1A) by jointly analyzing the mutation levels and searching the literature for genes associated with GC metastasis. We then performed a meta-analysis to demonstrate the relationship between these key driver gene mutations and GC metastasis, including lymphatic and distance metastasis.Results: We found out four key driver genes (TP53, PIK3CA, APC and ARID1A), associated with risk of GC metastasis. The results showed that TP53 (OR 1.39, 95% CI 1.12-1.72) and APC mutations (OR 0.58, 95% CI 0.38-0.89) were associated with lymph node metastasis and distant metastasis in GC. And TP53 mutations (OR 1.65, 95% CI 1.25-2.18) were significantly related to GC metastasis in the Asian population. APC mutations (OR 0.54, 95% CI 0.29-1.00) were also related to GC metastasis in the European and American populations. There was no significant association with GC metastasis in PIK3CA or ARID1A mutations.Expert opinion:Mutations of TP53 and APC play important roles in lymph node metastasis and distant metastasis of GC and may be potential important biomarkers of progression and therapeutic targets. These observations should be further prospectively verified.

2.
Int Wound J ; 2021 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-34219379

RESUMO

Current low-temperature plasma (LTP) devices essentially use a rare gas source with a short working distance (8 to 20 mm), low gas flow rate (0.12 to 0.3 m3 /h), and small effective treatment area (1-5 cm2 ), limiting the applications for which LTP can be utilised in clinical therapy. In the present study, a novel type of LTP equipment was developed, having the advantages of a free gas source (surrounding air), long working distance (8 cm), high gas flow rate (10 m3 /h), large effective treatment area (20 cm2 ), and producing an abundance of active substances (NOγ, OH, N2 , and O), effectively addressing the shortcomings of current LTP devices. Furthermore, it has been verified that the novel LTP device displays therapeutic efficacy in terms of acceleration of wound healing in normal and Type I diabetic rats, with enhanced wound kinetics, rate of condensation of wound area, and recovery ratio. Cellular and molecular analysis indicated that LTP treatment significantly reduced inflammation and enhanced re-epithelialization, fibroblast proliferation, deposition of collagen, neovascularization, and expression of TGF-ß, superoxide dismutase, glutathione peroxidase, and catalase in Type I diabetic rats. In conclusion, the novel LTP device provides a convenient and efficient tool for the treatment of clinical wounds.

3.
J Biosci ; 462021.
Artigo em Inglês | MEDLINE | ID: mdl-34219741

RESUMO

N-3-(oxododecanoyl)-L-homoserine lactone (3-O-C12-HSL), a small bacterial signaling molecule secreted by Pseudomonas aeruginosa (P. aeruginosa), can block dendritic cell (DC) maturation and participate in immune escape, but the underlying mechanism is unclear. We speculate that regulation of DC maturation and function by lncRNAs may be the mechanism by which 3-O-C12-HSL inhibits the immune response. We found that 3-O-C12-HSL increased the expression level of the lncRNA NRIR, impeding monocyte-derived dendritic cell (Mo-DC) maturation. In addition, we observed the effect of NRIR on the expression of CD40, CD80, HLA-DR and IL-6. NRIR overexpression significantly reduced the expression of Mo-DC surface markers, while 3-OC12-HSL did not significantly reduce the expression of Mo-DC surface markers after NRIR knockdown. These results indicate that 3-O-C12-HSL indeed affects the differentiation and maturation of Mo-DCs through NRIR. IL-6 stimulates T cell proliferation and activation, and we found that high NRIR expression reduced IL6 levels. However, under NRIR knockdown, 3-O-C12-HSL did not decrease IL-6 expression, suggesting that 3-O-C12-HSL may affect T cell activation through NRIR. This study is the first to elucidate the important role of a lncRNA in the mechanism of 3-O-C12-HSL activity. It also provides new ideas regarding P. aeruginosa infection pathogenesis.

4.
Insect Biochem Mol Biol ; 136: 103621, 2021 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-34233213

RESUMO

Mirid bugs are a group of important insect pests that cause large annual losses in agricultural production. Many studies have focused on the isolation and identification of sex pheromones in mirid bugs, and the components and biological activity of the sex pheromones have also been studied as a way to control these pests. However, few studies have focused on the mechanisms of pheromone perception. In this study, we identified the odorant receptor repertoire in three mirid bug species, Apolygus lucorum, Adelphocoris lineolatus, and Adelphocoris suturalis using antennal transcriptome sequencing and bioinformatics analysis. The candidate pheromone receptor (PR) genes were then identified by comparative transcriptomic and expression pattern analysis. Importantly, in vitro functional studies have shown that the candidate PRs have robust responses to the main mirid bug sex pheromone components (E)-2-hexenyl butyrate (E2HB) and hexyl butyrate (HB). Our study uncovered the mechanism of pheromone peripheral coding in these three species and elucidated the mechanism by which mirid bugs can specifically recognize a mate. Moreover, the results of our study will provide a theoretical basis for screening effective sex attractants or mating disturbance agents at the molecular and neural levels for enhanced control of these destructive pests.

5.
Adv Mater ; : e2102392, 2021 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-34302399

RESUMO

Polymer dielectrics with excellent processability and high breakdown strength (Eb ) enable the development of high-energy-density capacitors. Although the improvement of dielectric constant (K) of polymer dielectric has been realized by adding high-K inorganic fillers with high contents (>10 vol%), this approach faces significant challenges in scalable film processing. Here, the incorporation of ultralow ratios (<1 vol%) of low-K Cd1- x Znx Se1- y Sy nanodots into a ferroelectric polymer is reported. The polymer composites exhibit substantial and concurrent increase in both K and Eb , yielding a discharged energy density of 26.0 J cm-3 , outperforming the current dielectric polymers and nanocomposites measured at ≤600 MV m-1 . The observed unconventional dielectric enhancement is attributed to the structural changes induced by the nanodot fillers, including transformation of polymer chain conformation and induced interfacial dipoles, which have been confirmed by density function theory calculations. The dielectric model established in this work addresses the limitations of the current volume-average models on the polymer composites with low filler contents and gives excellent agreement to the experimental results. This work provides a new experimental route to scalable high-energy-density polymer dielectrics and also advances the fundamental understanding of the dielectric behavior of polymer nanocomposites at atomistic scales.

6.
Inflammopharmacology ; 29(4): 1187-1200, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34244900

RESUMO

Lagotis brachystachya Maxim is a herb widely used in traditional Tibetan medicine. Our previous study indicated that total extracts from Lagotis brachystachya could lower uric acid levels. This study aimed to further elucidate the active components (luteolin, luteoloside and apigenin) isolated from Lagotis brachystachya and the underlying mechanism in vitro and in vivo. The results showed that treatment with luteolin and luteoloside reversed the reduction of organic anion transporter 1 (OAT1) levels, while apigenin attenuated the elevation of urate transporter 1 (URAT1) and glucose transporter 9 (GLUT9) levels in uric acid-treated HK-2 cells, which was consistent with the finding in the kidneys of potassium oxonate (PO)-induced mice. On the other hand, hepatic xanthine oxidase activity was inhibited by the components. In addition, all of these active components improved the morphology of the kidney in hyperuricemic mice. Moreover, molecular docking showed that luteolin, luteoloside and apigenin could bind Toll-like receptor 4 (TLR4) and NLR family pyrin domain containing 3 (NLRP3). Congruently, western blot analysis showed that the components inhibited TLR4/myeloid differentiation primary response 88 (MyD88)/NLRP3 signaling. In conclusion, these results indicated that luteolin, luteoloside and apigenin could attenuate hyperuricemia by decreasing the production and increasing the excretion of uric acid, which were mediated by inhibiting inflammatory signaling pathways.

7.
PLoS Comput Biol ; 17(7): e1009162, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34252085

RESUMO

On March 23 2020, the UK enacted an intensive, nationwide lockdown to mitigate transmission of COVID-19. As restrictions began to ease, more localized interventions were used to target resurgences in transmission. Understanding the spatial scale of networks of human interaction, and how these networks change over time, is critical to targeting interventions at the most at-risk areas without unnecessarily restricting areas at low risk of resurgence. We use detailed human mobility data aggregated from Facebook users to determine how the spatially-explicit network of movements changed before and during the lockdown period, in response to the easing of restrictions, and to the introduction of locally-targeted interventions. We also apply community detection techniques to the weighted, directed network of movements to identify geographically-explicit movement communities and measure the evolution of these community structures through time. We found that the mobility network became more sparse and the number of mobility communities decreased under the national lockdown, a change that disproportionately affected long distance connections central to the mobility network. We also found that the community structure of areas in which locally-targeted interventions were implemented following epidemic resurgence did not show reorganization of community structure but did show small decreases in indicators of travel outside of local areas. We propose that communities detected using Facebook or other mobility data be used to assess the impact of spatially-targeted restrictions and may inform policymakers about the spatial extent of human movement patterns in the UK. These data are available in near real-time, allowing quantification of changes in the distribution of the population across the UK, as well as changes in travel patterns to inform our understanding of the impact of geographically-targeted interventions.

8.
Artigo em Inglês | MEDLINE | ID: mdl-34309506

RESUMO

A novel Gram-stain-negative and rod-shaped bacterial strain, designated as 4Y14T, was isolated from aquaculture water and characterized by using a polyphasic taxonomic approach. Strain 4Y14T was found to grow at 10-40 °C (optimum, 28 °C), at pH 7.0-9.0 (optimum, 7.0-8.0) and with 0-2 % NaCl (optimum, 1 %, w/v). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 4Y14T belonged to the genus Chitinilyticum with high levels of similarity to Chitinilyticum litopenaei c1T (97.8 %) and Chitinilyticum aquatile c14T (97.2 %). Phylogenomic analysis indicated that strain 4Y14T formed an independent branch distinct from the two type strains above. Digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between strain 4Y14T and the two type strains were, respectively, 25.3 and 25.0 %, and 81.2 and 80.3 %, which were well below the thresholds of 70 % DDH and 95-96 % ANI for species definition, implying that strain 4Y14T should represent a novel genospecies. The predominant cellular fatty acids of strain 4Y14T were summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) and iso-C16 : 0; the major polar lipids were diphosphatidylglycerol, phosphatidylcholine and phosphatidylethanolamine; and the sole respiratory quinone was Q-8. The genomic DNA G+C content was 60.1 mol%. Based on the phenotypic and genotypic analyses, strain 4Y14T is concluded to represent a novel species of the genus Chitinilyticum, for which the name Chitinilyticum piscinae sp. nov. is proposed. The type strain of the species is 4Y14T (=GDMCC 1.1934T=KACC 22080T).

9.
Artigo em Inglês | MEDLINE | ID: mdl-34310288

RESUMO

We consider the reconstruction problem of video snapshot compressive imaging (SCI), which captures high-speed videos using a low-speed 2D sensor. The underlying principle of SCI is to modulate sequential high-speed frames with different masks and then these encoded frames are integrated into a snapshot on the sensor and thus the sensor can be of low-speed.On one hand, video SCI enjoys the advantages of low-bandwidth, low-power and low-cost. On the other hand, applying SCI to large-scale problems (HD or UHD videos) in our daily life is still challenging and one of the bottlenecks lies in the reconstruction algorithm. Exiting algorithms are either too slow (iterative optimization algorithms) or not flexible to the encoding process (deep learning based end-to-end networks). In this paper, we develop fast and flexible algorithms for SCI based on the plug-and-play (PnP) framework. In addition to the PnP-ADMM, we further propose the PnP-GAP algorithm with a lower computational workload. Furthermore, we extend the proposed PnP algorithms to the color SCI system using mosaic sensors. A joint reconstruction and demosaicing paradigm is developed for flexible and high quality reconstruction of color video SCI systems. Extensive results on both simulation and real datasets verify the superiority of our proposed algorithm.

10.
Microb Biotechnol ; 2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34310854

RESUMO

The ß-nicotinamide mononucleotide (NMN) is a key intermediate of an essential coenzyme for cellular redox reactions, NAD. Administration of NMN is reported to improve various symptoms, such as diabetes and age-related physiological decline. Thus, NMN is attracting much attention as a promising nutraceutical. Here, we engineered an Escherichia coli strain to produce NMN from cheap substrate nicotinamide (NAM) and glucose. The supply of in vivo precursor phosphoribosyl pyrophosphate (PRPP) and ATP was enhanced by strengthening the metabolic flux from glucose. A nicotinamide phosphoribosyltransferase with high activity was newly screened, which is the key enzyme for converting NAM to NMN with PRPP as cofactor. Notably, the E. coli endogenous protein YgcS, which function is primarily in the uptake of sugars, was firstly proven to be beneficial for NMN production in this study. Fine-tuning regulation of ygcS gene expression in the engineered E. coli strain increased NMN production. Combined with process optimization of whole-cell biocatalysts reaction, a final NMN titre of 496.2 mg l-1 was obtained.

11.
Vascular ; : 17085381211035282, 2021 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-34311590

RESUMO

BACKGROUND: It is indicated that Low-density lipoprotein cholesterol/high-density lipoprotein cholesterol ratio (LDL-C/HDL-C ratio) has greater predictive value for thickened carotid intima-media thickness (CIMT) comparing with classic lipid parameters. However, there have been few reports about their association in general Chinese population. METHOD: We included a total of 1220 CIMT participants and 2440 matched controls, who had ultrasonography of carotid artery during 2009 and 2016. Univariate and multivariate logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for thickened CIMT risk associated with LDL-C/HDL-C ratio. RESULT: In the univariate logistic regression model, there was significant association between LDL-C/HDL-C ratio and thickened CIMT (Q4 vs. Q1, OR = 1.94, 95% CI: 1.60-2.36; ptrend < 0.05). After adjusting for potential covariates, LDL-C/HDL-C ratio remained significantly associated with thickened CIMT (Q4 vs. Q1, OR = 1.81, 95% CI: 1.41-2.34, ptrend < 0.001; ≥3.05 v.s. <3.05, OR = 1.66, 95% CI: 1.37-2.02). In subgroup analyses, the association between LDL-C/HDL-C ratio and thickened CIMT remained significant in the subgroups stratified by sex, impaired fasting glucose (IFG), hypertension, and fatty liver disease but only remained significant in the subgroups of ≥45 years (OR = 2.01, 95% CI: 1.46-2.76; Ptrend<0.05), BMI ≥24 (kg/m2) (OR = 2.22; 95% CI = 1.63-3.03; Ptrend < 0.05) and BMI ≥25 (kg/m2) (OR = 2.50, 95% CI: 1.76-3.54; Ptrend < 0.05), dyslipidemia (OR = 3.28, 95% CI: 1.83-5,85; Ptrend < 0.001), and without periodontitis (OR = 2.08, 95% CI: 1.54-2.81 ; Ptrend < 0.05) comparing Q4 to Q1. Similar results were observed in the subgroup analyses for LDL-C/HDL-C ratio ≥3.05 v.s. <3.05 except for the age stratification. CONCLUSION: High LDL-C/HDL-C ratio could significantly increase the risk of thickened CIMT independent of gender, IFG, hypertension, and fatty liver disease in general Chinese population.

12.
BMC Musculoskelet Disord ; 22(1): 640, 2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34311715

RESUMO

BACKGROUND: Depression has been shown in some studies to be associated with knee pain. Females were widely recognized as more vulnerable to depression and knee pain than males. However, the role of sex in this correlation was under-researched. This study aimed to investigate the association between depressive symptoms and subsequent knee pain, as well as whether and how sex would moderate this association based on a four-wave (Wave 1 in 2010-2011, Wave 2 in 2013, Wave 3 in 2015, and Wave 4 in 2018) longitudinal study among middle-aged and elderly Chinese adults. METHODS: Seventeen thousand seven hundred eight participants were recruited and followed in the China Health and Retirement Longitudinal Study (CHARLS). Ten thousand four hundred fifty-one entered the final analysis based on the inclusion and exclusion criteria. Knee pain was assessed by self-report. Depressive symptoms were evaluated using the validated 10-item Center for Epidemiological Studies-Depression Scale (CESD-10). Cox proportional hazards models were used to calculate hazard ratios with 95% confidence intervals (CIs) after controlling potential confounders to examine the association between depressive symptoms and subsequent incident and persistent knee pain. Non-linear association of depressive symptoms score (CESD-10) and risk of knee pain was also investigated via applying 3-knotted restricted cubic spline regression. An interaction term of depressive symptoms status and sex was added to investigate the moderating effect of sex on the relationship between depressive symptoms status and the risk of knee pain. RESULTS: The median follow-up time was seven years for all the outcomes. Participants with depressive symptoms were 1.45 times (95% CI: 1.34-1.56) and 2.16 times (95% CI: 1.85-2.52) more likely to develop the incident and persistent knee pain after multivariable were adjusted, compared with those without depressive symptoms. There was a non-linear association between CESD-10 score and risk of knee pain. Compared with females, males had an enhanced correlation between depressive symptoms status and knee pain (multivariable-adjusted HR: 1.22, 95% CI: 1.05-1.42 and HR: 1.57, 95% CI: 1.14-2.17 for the incident and persistent knee pain, respectively). CONCLUSION: Depressive symptoms are independently associated with an excess risk of knee pain, with a stronger correlation for males than females among middle-aged and elderly Chinese adults.

13.
Stroke Vasc Neurol ; 2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34312319

RESUMO

There has been growing interest and insight into the histological composition of retrieved stroke emboli. One of the main focuses of the stroke clot analysis literature has been the implications of clot composition on mechanical thrombectomy procedures. However, the holy grail of clot analysis may not be in the field of clot-device interaction, but rather, in understanding mechanisms of fibrinolysis resistance. The mechanisms underlying the low response to fibrinolytic therapy, even with the newer, more powerful agents, remain poorly understood. While factors such as embolus size, location and collateral status influence alteplase delivery and recanalisation rates; compositional analyses focused on histological and ultrastructural characteristics offer unique insights into mechanisms of alteplase resistance. In this review, we strive to provide comprehensive review of current knowledge on clot composition and ultrastructural analyses that help explain resistance to fibrinolysis.

14.
Sci Rep ; 11(1): 15205, 2021 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-34312430

RESUMO

Renal injury is common in patients with coronavirus disease 2019 (COVID-19). We aimed to determine the relationship of estimated glomerular filtration rate (eGFR) and acute kidney injury (AKI) with the characteristics, progression, and prognosis of COVID-19 in-patients. We retrospectively reviewed 1851 COVID-19 patients admitted to 3 hospitals in Wuhan, China. Clinical, laboratory, radiological, treatment, complication, and outcome data were analyzed. Patients were stratified according to levels of eGFR (≥ 90 vs. 60-89 vs. < 60 mL/min/1.73 m2). The risk of reaching the composite endpoint-intensive care unit admission, invasive ventilation, or death-was compared. On admission, 25.5% patients had renal impairment (eGFR < 90 mL/min/1.73 m2), but only 2.6% patients had chronic kidney disease (CKD). The overall in-hospital AKI incidence was 6.7%. Severe illness and comorbidities (hypertension, diabetes, CKD, and cardiovascular/cerebrovascular diseases) were more common among patients with low eGFR (< 90 mL/min/1.73 m2). Despite the more frequent use of intensive oxygen therapy, continuous blood purification, and glucocorticoid treatment, the prognosis of these patients was unsatisfactory, with the incidence of the composite endpoint (15.4% vs. 19.6% vs. 54.5%; P = 0.000) and complications (AKI, respiratory failure, cardiac injury, coagulation disorders, sepsis, etc.) increasing with decreasing eGFR. Kaplan-Meier survival analysis revealed that patients with eGFR < 90 mL/min/1.73 m2 or AKI had significantly escalated risks of reaching the composite endpoint. Multivariate regression analysis showed that renal insufficiency (eGFR < 60 mL/min/1.73 m2) on admission and in-hospital AKI independently predicted poor prognosis among COVID-19 in-patients. And renal impairment on admission was a greater predictor of poor prognosis in non-elderly patients than that in elderly patients. Early and continuous renal-function monitoring and early AKI diagnosis are necessary to predict and prevent the progression of COVID-19.

15.
Artigo em Inglês | MEDLINE | ID: mdl-34312758

RESUMO

Cadmium (Cd) has strong mobility and could cause toxicity to plants, and selenium (Se) can effectively detoxify Cd stress. However, differences in the detoxification effects of different species and dosages of exogenous Se on Cd and its mechanism are still unclear. In this study, a pot experiment was conducted to determine the effects of different rates of selenite and selenate application on radish growth, the uptake and translocation of Cd, and the fractions of Cd transformation in native Cd-contaminated soil. Results indicated that the decrease in radish biomass in selenate treatment was significantly greater than that in selenite treatment at a high Se application rate (2.5 mg·kg-1) (p < 0.05). In contrast to selenite treatments, the application of selenate significantly increased the translocation of Cd from radish roots to shoots (p < 0.05). Cadmium concentration and its bioaccumulation factor in radish decreased gradually with increasing selenite application rates, while these values decreased at low Se rate (1 mg·kg-1) and increased at high Se rate for selenate treatment. Different Se application rates resulted in Cd fractions distributions to change in soil. Therefore, the application of selenite treatment had a greater detoxification effect on Cd in soil than that in selenate treatment, and the double toxic effect was observed between Se and Cd in high selenate treatment (2.5 mg·kg-1). Combined with human health risk asseeement, the application of 2.5 mg·kg-1 selenite could be a good approach for detoxification in native Cd-contaminated soil used in this study.

16.
Int J Cosmet Sci ; 2021 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-34312881

RESUMO

Skin, our first interface to the external environment, is subjected to oxidative stress caused by a variety of factors such as solar ultraviolet, infrared, and visible light, environmental pollution, including ozone and particulate matters, and psychological stress. Excessive reactive species, including reactive oxygen species and reactive nitrogen species, exacerbate skin pigmentation and aging, which further lead to skin tone unevenness, pigmentary disorder, skin roughness, and wrinkles. Besides these, skin microbiota is also a very important factor ensuring the proper functions of skin. While environmental factors such as UV and pollutants impact skin microbiota compositions, skin dysbiosis results in various skin conditions. In this review, we summarize the generation of oxidative stress from exogenous and endogenous sources. We further introduce current knowledge on the possible roles of oxidative stress in skin pigmentation and aging, specifically with emphasis on oxidative stress and skin pigmentation. Meanwhile, we summarize the science and rationale of using three well-known antioxidants, namely vitamin C, resveratrol, and ferulic acid, in the treatment of hyperpigmentation. Finally, we discuss the strategy for preventing oxidative stress-induced skin pigmentation and aging.

17.
Artigo em Inglês | MEDLINE | ID: mdl-34313106

RESUMO

The development of a highly efficient and stable catalyst for preferential oxidation of CO for the commercialization of proton-exchange membrane fuel cells has been a result of continuous effort. The main challenge is the simultaneous control of abundant active sites and interfacial reducibility over the catalyst CuxO/CeO2. Here, we report a strategy to modulate porosity, active sites, and O-vacancy sites (OV) by reducing media and O2/H2 activation. O2-pretreated CeO2-supported Cu catalysts unequivocally demonstrate the low-temperature activity owing to the excess concentrations of Cu+ and Cu2+ as well as the relative population of Ce3+ and O-vacancy sites at the surface. O2 activation improves the Cu2+ diffusion into the CeO2 lattice to generate the synergistic effect and induces the formation of electron-enriched Cu2+-OV-Ce3+ sites, which accelerate the activation and dissociation of CO/O2 and the formation of reactive oxygen species during catalysis. Density function theory (DFT) calculations reveal that CO adsorbs on Cu2O {110} and CuO {111} with relatively optimal adsorption energy and longer C-Cu lengths in contrast to that on Cu {111}, favoring the adsorption and desorption of CO. These are crucial for ongoing CO oxidation, producing CO2 by the Mars-van Krevelen mechanism.

18.
Environ Res ; 201: 111611, 2021 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-34217719

RESUMO

Although emerging researches have linked ambient fine particulate matter (PM2.5) to obesity, evidence from high-polluted regions is still lacking. We thus assessed the long-term impacts of PM2.5 on body mass index (BMI) and the risk of the prevalence of overweight/obesity (BMI≥25 kg/m2), by incorporating the well-established Prediction for Atherosclerotic Cardiovascular Disease Risk in China (China-PAR) project comprising 77,609 participants with satellite-based PM2.5 estimates at 1-km spatial resolution. The average of long-term PM2.5 level was 70.4 µg/m3, with the range of 32.1-94.2 µg/m3. Each 10 µg/m3 increment of PM2.5 was associated with 0.421 kg/m2 (95% confidence interval [CI]: 0.402, 0.439) and 13.5% (95% CI: 12.8%, 14.3%) increased BMI and overweight/obesity risk, respectively. Moreover, compared with the lowest quartile of PM2.5 (≤57.5 µg/m3), the relative risk of the prevalence of overweight/obesity from the highest quartile (>85.9 µg/m3) was 1.611 (95% CI: 1.566, 1.657). The exposure-response curve suggested a non-linear relationship between PM2.5 exposure and overweight/obesity. Besides, the association was modified by age, diabetes mellitus, hypertension and dyslipidemia status. Our study provides the evidence for the adverse impacts of long-term PM2.5 on BMI and overweight/obesity in China, and the findings are important for policy development on air quality, especially in severely polluted areas.

19.
Biomater Sci ; 9(15): 5116-5126, 2021 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-34254606

RESUMO

3D printing of a stiff and lubricative hydrogel-based meniscus substitute has been challenging since printability and stiffness compromise each other. In this work, based on an upgraded self-thickening and self-strengthening strategy, a unique multiple H-bonding monomer N-acryloylsemicarbazide (NASC) is firstly copolymerized with a super-hydrophilic monomer carboxybetaine acrylamide (CBAA) in dimethyl sulfoxide (DMSO)/H2O to form a soft poly(NASC-co-CBAA) gel, in which PCBAA serves to weaken the H-bonding interaction and avoid hydrophobic phase separation. The poly(NASC-co-CBAA) gel is then loaded with concentrated NASC and CBAA, followed by heating to form a thickening sol ink, which is printed into different objects that are further photoirradiated to initiate the copolymerization of entrapped NASC and CBAA, resulting in the formation of a high performance hydrogel with a Young's modulus of 10.98 MPa, tensile strength of 1.87 MPa and tearing energy of 5333 J m-2 after DMSO is completely replaced with water, due to the re-establishment of NASC H-bonds. Importantly, PCBAA affords high lubricity in printed hydrogels. The printed PNASC-PCBAA meniscus substitute can substitute rabbit's native meniscus and ameliorate the cartilage surface wear within a set 12-week time window, portending great potential as a meniscal substitute and other soft-supporting tissue scaffolds.

20.
Acta Biomater ; 2021 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-34271171

RESUMO

Doxorubicin (DOX) is a cornerstone drug in the treatment of osteosarcoma. However, achieving sufficient concentration in the tumor tissue after systemic administration with few side effects has been a challenge. Even with the most advanced nanotechnology approaches, less than 5% of the total administered drug gets delivered to the target site. Alternatives to increase the local concentration of DOX within the tumor using improved drug delivery methods are needed. In this study, we evaluate a clinically approved calcium sulfate/hydroxyapatite (CaS/HA) carrier, both in-vitro and in-vivo, for local, sustained and controlled delivery of DOX to improve osteosarcoma treatment. In-vitro drug release studies indicated that nearly 28% and 36% of the loaded drug was released over a period of 4-weeks at physiological pH (7.4) and acidic pH (5), respectively. About 63% of the drug had been released after 4-weeks in-vivo. The efficacy of the released drug from the CaS/HA material was verified on two human osteosarcoma cell lines MG-63 and 143B. It was demonstrated that the released drug fractions functioned the same way as the free drug without impacting its efficacy. Finally, the carrier system with DOX was assessed using two clinically relevant human osteosarcoma xenograft models. Compared to no treatment or the clinical standard of care with systemic DOX administration, the delivery of DOX using a CaS/HA biomaterial could significantly hinder tumor progression by inhibiting angiogenesis and cell proliferation. Our results indicate that a clinically approved CaS/HA biomaterial containing cytostatics could potentially be used for the local treatment of osteosarcoma. STATEMENT OF SIGNIFICANCE: The triad of doxorubicin (DOX), methotrexate and cisplatin has routinely been used for the treatment of osteosarcoma. These drugs dramatically improved the prognosis, but 45-55% of the patients respond poorly to the treatment with low 5-year survival. In the present study, we repurpose the cornerstone drug DOX by embedding it in a calcium sulfate/hydroxyapatite (CaS/HA) biomaterial, ensuring a spatio-temporal drug release and a hypothetically higher and longer lasting intra-tumoral concentration of DOX. This delivery system could dramatically hinder the progression of a highly aggressive osteosarcoma compared to systemic administration, by inhibiting angiogenesis and cell proliferation. Our data show an efficient method for supplementary osteosarcoma treatment with possible rapid translational potential due to clinically approved constituents.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...