Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.963
Filtrar
1.
Food Chem ; 367: 130680, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34348198

RESUMO

This study investigated the effect of different types of smoking materials on the flavor, heterocyclic aromatic amine (HAA) content, and sensory attributes of smoked chicken drumsticks. All smoked samples showed lower pH and L*-value and higher a*-value and b*-value than the control sample (P < 0.05), but no significant differences in water content and water activity (P > 0.05). The samples smoked with sucrose combined with pear-tree woodchips (SP) or green tea leaves (ST) had higher overall acceptability than other samples (P < 0.05). Smoking increased the total HAA content, and the ST sample exhibited the highest total HAA content (P < 0.05). A total of 54 volatile compounds was identified. Overall, SP and ST are suitable for smoked chicken considering the sensory properties, while S and SA are proper for smoked chicken considering the minimization of HAAs, which may provide a theory basis for the production of smoked chicken.


Assuntos
Galinhas , Compostos Heterocíclicos , Aminas/análise , Animais , Fumaça , Fumar
2.
Food Chem ; 367: 130756, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34388633

RESUMO

This study was aimed at evaluating the potential of high-intensity ultrasound (HIU, 450 W for 10 min) combined with hydrogen peroxide (H2O2) having various concentrations (0, 50, 100, 200, 400, 800 µmol/g protein) to inhibit the thermal aggregation behavior of myofibrillar proteins (MPs) in water. The results indicated that the addition of H2O2 interfered with the intermolecular sulfhydryl-disulfide interchange and inhibited the disulfide bond cross-linking. The H2O2-mediated conversion of cysteine to thiol derivatives appeared to be the primary mechanism of this effect. The HIU combined with H2O2, especially at the H2O2 concentration of 200 µmol/g, corresponded to a more significant inhibitory effect than that of only H2O2, which attributed to the dissociation of the filamentous myosin structure that led to an enhanced accessibility of the buried sulfhydryl groups. In conclusion, these findings provide direct evidence for the role of HIU combined with H2O2 in improving the thermal stability of MPs.


Assuntos
Peróxido de Hidrogênio , Água , Concentração de Íons de Hidrogênio , Miosinas , Compostos de Sulfidrila
3.
J Colloid Interface Sci ; 606(Pt 2): 1055-1063, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34487928

RESUMO

Ammonia (NH3) plays an important role in agriculture and industry. The industry-scale production mainly depends on the Haber-Bosch process suffering from issues of environment pollution and energy consumption. Electrochemical reduction can degrade nitrite (NO2-) pollutants in the environment and convert it into more valuable NH3. Here, Ni2P nanosheet array on nickel foam is proposed as a 3D electrocatalyst for high-efficiency electrohydrogenation of NO2- to NH3 under ambient reaction conditions. When tested in 0.1 M phosphate buffer saline with 200 ppm NO2-, such Ni2P/NF is able to obtain a large NH3 yield rate of 2692.2 ± 92.1 µg h-1 cm-2 (3282.9 ± 112.3 µg h-1 mgcat.-1), a high Faradic efficiency of 90.2 ± 3.0%, and selectivity of 87.0 ± 1.7% at -0.3 V versus a reversible hydrogen electrode. After 10 h of electrocatalytic reduction, the conversion rate of NO2- achieves near 100%. The catalytic mechanism is further investigated by density functional theory calculations.


Assuntos
Amônia , Nitritos
4.
Dev Comp Immunol ; 127: 104305, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34718077

RESUMO

Beetles are the most diverse group of insects in Insecta which can be found in almost every habitat and environment on Earth. The possessing of the rapid and effective immune defenses is one of the important factors for their success. It is generally recognized that beetles only rely on the non-specific innate immune defense, without immunological memory, to fight against pathogens. However, there was cumulative evidence for the innate immune memory in invertebrates, including beetles, over the last decades, implying that insect innate immunity is more complex and has more features than previously thought. In beetles, it has been well documented that the specific or nonspecific enhanced immunocompetence can persist throughout development within generations and can even be transferred to the descendents in the next generation. Although insect immune priming might be shaped by epigenetic modifications and transferring effectors, mRNA and microbial signals, the solid experimental evidence to support the causal relationship between any of them and immune priming is still scarce. The combined usage of 'omics' approaches and CRISPR/Cas9 in the appropriate insect models with well-known genetic background, Tribolium castaneum and Tenebrio molitor, will help us to decipher the molecular mechanisms by which immune priming occurs in beetles in depth.

5.
Sci Total Environ ; 806(Pt 1): 150535, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34582857

RESUMO

Anthropogenic activities in river basins, especially large-scale water conservancy projects, have notably impacted the physical, chemical and ecological environments of estuaries and coastal areas. In this paper, the effects of water and sediment regulation (WSR) on the concentration and transport of heavy metals in the Yellow River were studied based on a continuous daily heavy metal survey in both the middle reaches (Xiaolangdi station) and lower reaches (Lijin station) of the Yellow River during the WSR period in 2019. The results indicated that the variation in the water oxidation-reduction environment of the Xiaolangdi reservoir during the WSR process exerted an important impact on the concentrations of dissolved Cu, Cd, Pb, Cr and As at the Xiaolangdi station but exerted almost no influence on the concentration of dissolved Ni. At Lijin station, the dissolved heavy metal content first increased and then decreased in the first stage, which mainly depended on the release of heavy metals from resuspended sediments. In the second stage, the heavy metal content gradually decreased due to adsorption onto fine particles discharged from the reservoir. The dissolved heavy metal flux during the water-sediment regulation scheme (WSRS) period accounted for 16.9-33.4% of the annual total dissolved heavy metal flux. WSRS changed transport of water and sediment. The dissolved heavy metal concentrations at the Xiaolangdi station were mainly controlled by the discharge of water and sediments from the Xiaolangdi reservoir, while the dissolved heavy metal concentration at the Lijin station was largely affected by the sediments resuspended from downstream riverbeds and the water and sediment scheduling mode of the Xiaolangdi reservoir. Dissolved heavy metal transportation was highly influenced by the WSR process within a short time. Human intervention, especially WSRS operation, apparently alters the natural states of both the mainstream and estuarine environments of the Yellow River.


Assuntos
Metais Pesados , Poluentes Químicos da Água , China , Monitoramento Ambiental , Sedimentos Geológicos , Humanos , Metais Pesados/análise , Água , Poluentes Químicos da Água/análise
6.
Environ Pollut ; 292(Pt A): 118312, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34627962

RESUMO

Inhalation of respirable silica particles can cause serious lung diseases (e.g., silicosis and lung cancer), and the toxicity of respirable silica is highly dependent on its crystal form. Common combustion processes such as coal and biomass burning can provide high temperature environments that may alter the crystal forms of silica and thus affect its toxic effects. Although crystalline silica (i.e., quartz, tridymite, and cristobalite) were widely found at different temperatures during the burning processes, the sources and crystal transformation pathways of silica in the burning processes are still not well understood. Here, we investigate the crystal transformation of silica in the coal and biomass combustion processes and clarify the detailed transformation pathways of silica for the first time. Specifically, in coal burning process, amorphous silica can transform into quartz and cristobalite starting at 1100 °C, and quartz transforms into cristobalite starting at 1200 °C; in biomass burning process, amorphous silica can transform into cristobalite starting at 800 °C, and cristobalite transforms into tridymite starting at 1000 °C. These transformation temperatures are significantly lower than those predicted by the classic theory due to possibly the catalysis of coexisting metal elements (e.g., aluminum, iron, and potassium). Our results not only enable a deeper understanding on the combustion-induced crystal transformation of silica, but also contribute to the mitigation of population exposure to respirable silica.


Assuntos
Carvão Mineral , Dióxido de Silício , Alumínio , Biomassa , Quartzo
7.
J Hazard Mater ; 423(Pt A): 127088, 2022 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-34482077

RESUMO

Antibiotic resistance has become a global public health problem. Recently, various environmental pollutants have been reported to induce the proliferation of antibiotic resistance. However, the impact of multiple pollutants (e.g., heavy metals and antibiotics), which more frequently occur in practical environments, is poorly understood. Herein, one widely distributed heavy metal (Ag+) and one frequently detected antibiotic (tetracycline) were chosen to investigate their coexisting effect on the proliferation of antibiotic resistance in the activated sludge system. Results show that the co-occurrence of Ag+ and tetracycline at environmentally relevant concentrations exhibited no distinct inhibition in reactor performances. However, they inhibited the respiratory activity by 42%, destroyed the membrane structure by 218%, and increased membrane permeability by 29% compared with the blank control bioreactor. Moreover, the relative abundances of target antibiotic resistance genes (ARGs) (e.g., tetA, blaTEM-1, and sulII) in effluent after exposure of coexisting Ag+ and tetracycline were increased by 92-1983% compared with those in control reactor, which were 1.1-4.3 folds higher than the sum of the sole ones. These were possibly attributed to the enrichments of antibiotic-resistant bacteria. The results would illumine the coexisting effect of heavy metals and antibiotics on the dissemination of ARGs in activated sludge system.

8.
Hum Mol Genet ; 2021 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-34849858

RESUMO

Although previous studies identified numerous single nucleotide polymorphisms (SNPs) and their target genes predisposed to prostate cancer (PrCa) risks, SNP-related splicing associations are rarely reported. In this study, we applied distance-based sQTL analysis (sQTLseekeR) using RNA-seq and SNP genotype data from benign prostate tissue (n = 467), and identified significant associations in 3344 SNP-transcript pairs (P ≤ 0.05) at PrCa risk loci. We characterized a common SNP (rs7247241) and its target gene (PPP1R14A) located in chr19q13, a sQTL with risk allele T associated with upregulation of long isoform (P = 9.99E-7). We confirmed the associations in both TCGA (P = 2.42E-24) and GTEX prostate cohorts (P = 9.08E-78). To functionally characterize this SNP, we performed chromatin Immunoprecipitation qPCR and confirmed stronger CTCF and PLAGL2 binding in rs7247241 C than T allele. We found that CTCF binding enrichment was negatively associated with methylation level at the SNP site in human cell lines (r = -0.58). Bisulfite sequencing showed consistent association of rs7247241-T allele with nearby sequence CpG hypermethylation in prostate cell lines and tissues. Importantly, the methylation level at CpG sites nearest to the CTCF binding and first exon splice-in (ψ) of PPP1R14A were significantly associated with aggressive phenotype in the TCGA PrCa cohort. Meanwhile, the long isoform of the gene also promoted cell proliferation. Taken together, with the most updated gene annotations, we reported a set of sQTL associated with multiple traits related to human prostate diseases, and revealed a unique role of PrCa risk SNP rs7247241 on PPP1R14A isoform transition.

9.
Front Pharmacol ; 12: 732874, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34744717

RESUMO

Background: Cerebral small vessel disease (CSVD) is a group of clinical syndromes covering all pathological processes of small vessels in the brain, which can cause stroke and serious dementia. However, as the pathogenesis of CSVD is not clear, so the treatment is limited. Endothelial cell dysfunction is earlier than clinical symptoms, such as hypertension and leukosis. Therefore, the treatment of endothelial cells is expected to be a new breakthrough. Quercetin, a flavonoid present in a variety of plants, has the function of anti-inflammation and anti-oxidation. This study aimed to investigate the protective effect of quercetin on endothelial cell injury and provide a basic theory for subsequent application in the clinic. Methods: Human brain microvascular endothelial cells (HBMECs) were cultured in vitro, and the injury model of endothelial cells was established by hypoxia and reoxygenation (H/R). The protective effects of quercetin on HBMECs were studied from the perspectives of cell viability, cell migration, angiogenesis and apoptosis. In order to further study the mechanism of quercetin, oxidative stress and endoplasmic reticulum stress were analyzed. What's more, blood-brain barrier (BBB) integrity was also studied. Results: Quercetin can promote the viability, migration and angiogenesis of HBMECs, and inhibit the apoptosis. In addition, quercetin can also activate Keap1/Nrf2 signaling pathway, reduce ATF6/GRP78 protein expression. Further study showed that quercetin could increase the expression of Claudin-5 and Zonula occludens-1. Conclusions: Our experiments show that quercetin can protect HBMECs from H/R, which contains promoting cell proliferation, cell migration and angiogenesis, reducing mitochondrial membrane potential damage and inhibiting cell apoptosis. This may be related to its antioxidation and inhibition of endoplasmic reticulum stress. At the same time, quercetin can increase the level of BBB connexin, suggesting that quercetin can maintain BBB integrity.

10.
Artigo em Inglês | MEDLINE | ID: mdl-34745281

RESUMO

Objective: To investigate the pre- and postsurgical clinical characteristics and clinical efficacy of patients with uveitis. Methods: The clinical data of patients with uveitis who underwent vitrectomy in our hospital from March 2019 to February 2021 were retrospectively analyzed. There were 52 cases of 64 eyes in total. The data on patient's gender, age, etiology, course of disease, anatomical classification, number of recurrences, changes in vision before and after surgery, changes in eye signs before and after surgery, and occurrence of postoperative complications were collected. The clinical features before and after vitrectomy were compared, and the influencing factors of clinical efficacy were analyzed. Results: The ocular signs of patients with uveitis after vitrectomy were significantly improved compared with before operation, and the difference was statistically significant (P < 0.05). The visual acuity after vitrectomy in patients with uveitis was significantly improved compared with that before operation, and the difference was statistically significant (P < 0.05). There was no significant difference in the surgical treatment of uveitis patients of different gender, age, and etiology (P > 0.05). There are significant differences in the clinical efficacy of vitrectomy in patients with different anatomical classifications. Among them, patients with panuveitis have the best clinical efficacy with vitrectomy and patients with posterior uveitis have the worst clinical efficacy with vitrectomy (P < 0.05). There is a significant difference in the clinical efficacy of vitrectomy in patients with recurrence times. The lower the number of recurrences, the better the clinical efficacy of vitrectomy in patients (P < 0.05). Conclusion: There are significant differences in the clinical signs of patients with uveitis before and after vitrectomy. Vitrectomy is effective in the treatment of uveitis. The type of anatomy and the number of recurrences are influencing factors for the clinical efficacy of vitrectomy. For patients with posterior uveitis, the surgical method should be carefully considered or a more reasonable treatment method should be selected, and for patients with uveitis with less recurrence, vitrectomy should be considered for active treatment.

11.
Mitochondrial DNA B Resour ; 6(12): 3336-3337, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34746407

RESUMO

In this study, the complete chloroplast genome of Loropetalum chinense var. rubrum Yieh was sequenced and characterized. The chloroplast genome is 159,427 bp in length, and contains a large single-copy (LSC) region of 88,185 bp and a small single-copy (SSC) region of 18,772 bp separated by a pair of inverted repeat (IR) regions of 26,235 bp. There are 128 genes in the genome including 83 protein-coding, 37 tRNA, and eight rRNA genes. The overall GC is 38.0% and the LSC, SSC, and IR regions are 36.1, 32.7, and 43.1%, respectively. Phylogenetic analysis of L. chinense var. rubrum fully resolved it in a clade with L. subcordatum. This complete chloroplast genome will provide valuable insight into evolution, molecular breeding, and phylogenetic analysis of Loropetalum species.

12.
Front Plant Sci ; 12: 739159, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34751224

RESUMO

Seawater acidification and nutrient alteration are two dominant environmental factors in coastal environments that influence the dynamics and succession of marine microalgae. However, the impacts of their combination have seldom been recorded. A simulated experimental system was set up to mimic the effects of elevated acidification on a bloom-forming dinoflagellate, Karenia mikimotoi, exposed to different nutrient conditions, and the possible mechanism was discussed. The results showed that acidification at different pH levels of 7.6 or 7.4 significantly influenced microalgal growth (p<0.05) compared with the control at pH 8.0. Mitochondria, the key sites of aerobic respiration and energy production, were impaired in a pH-dependent manner, and a simultaneous alteration of reactive oxygen species (ROS) production occurred. Cytochrome c oxidase (COX) and citrate synthase (CS), two mitochondrial metabolism-related enzymes, were actively induced with acidification exposure, suggesting the involvement of the mitochondrial pathway in coping with acidification. Moreover, different nutrient statuses indicated by various N:P ratios of 7:1 (N limitation) and 52:1 (P limitation) dramatically altered the impacts of acidification compared with those exposed to an N:P ratio of 17:1 (control), microalgal growth at pH 7.4 was obviously accelerated with the elevation of the nutrient ratio compared to that at pH 8.1 (p<0.05), and nutrient limitations seemed beneficial for growth in acidifying conditions. The production of alkaline phosphatase (AP) and acid phosphatase (AcP), an effective index indicating the microalgal growth status, significantly increased at the same time (p<0.05), which further supported this speculation. However, nitrate reductase (NR) was slightly inhibited. Hemolytic toxin production showed an obvious increase as the N:P ratio increased when exposed to acidification. Taken together, mitochondrial metabolism was suspected to be involved in the process of coping with acidification, and nutrient alterations, especially P limitation, could effectively alleviate the negative impacts induced by acidification. The obtained results might be a possible explanation for the competitive fitness of K. mikimotoi during bloom development.

13.
Nanotechnology ; 2021 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-34763323

RESUMO

The electrode material is vital for the performance of the electrochemical biosensor. Lately, many nanomaterials have been developed to improve the sensitivity and detection efficiency of the biosensors. In this work, a kind of one-dimensional nanomaterials, the CuPt alloy nanotubes with an open end (CuPt alloy NTs-AOE), was explored. The nanotubes with an open end can provide a larger electrochemical active surface area and more active sites for the immobilization of enzyme. The CuPt alloy displays excellent conductivity and catalytic activity. In addition, the Cu shows the great affinity to thio-compounds, which can greatly enhance the detection efficiency and sensitivity. As a result, the prepared biosensor demonstrates the wider linear range of 9.98×10-10 - 9.98×10-5 g/L for fenitrothion and 9.94×10-11 - 9.94×10-4 g/L for dichlorvos (as model OPs ) and with the lower detection limit of 1.84 ×10-10 g/L and 6.31×10-12 g/L (S/N = 3), respectively. Besides, the biosensor has been used to detect the real samples and obtains satisfactory recoveries (95.58 % - 100.56 %).

14.
Dis Colon Rectum ; 2021 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-34759244

RESUMO

BACKGROUND: The safety and feasibility of laparoscopic surgery for the management of rectal gastrointestinal stromal tumors are unknown. OBJECTIVE: To compare the surgical and oncologic results of laparoscopic versus open surgery for the treatment of rectal gastrointestinal stromal tumors. DESIGN: Retrospective multicenter propensity score-matched study to minimize heterogeneity between groups and focus on the difference between surgery strategies. SETTINGS: Eleven Chinese tertiary hospitals participated in this study. PATIENTS: A total of 364 patients with pathologically confirmed rectal gastrointestinal stromal tumors were retrospectively analyzed. MAIN OUTCOME MEASURES: Relapse-free survival, postoperative hospital stay length, and 30-day postoperative complication rate. RESULTS: We enrolled 214 patients who underwent surgical operation for primary localized rectal gastrointestinal stromal tumors. After propensity score matching, 134 cases involved in the comparison (67 laparoscopic vs. 67 open surgery) were randomly matched (1:1) by sex, age, tumor size, tumor site, and neoadjuvant therapy. The laparoscopic surgery group had superior relapse-free survival (χ2 = 4.46, p = 0.04), and fewer complications (6.0% vs. 25.4%, p = 0.002). No significant difference was found in the length of postoperative hospital stay between the laparoscopic surgery and open surgery groups (9.66 ± 5.42 vs. 10.64 ± 4.93, p = 0.28). Subgroup analysis showed that the laparoscopic surgery group had superior relapse-free survival (χ2 = 4.14, p = 0.04) and fewer complications after surgery (2.9% vs. 24.4%, p = 0.01) in the rectal gastrointestinal stromal tumors ≤ 5 cm subgroup. LIMITATIONS: The nature of retrospective review and relatively short follow-up period are limitations of this study. CONCLUSIONS: Laparoscopic surgery offers a safe and feasible option for the radical resection of primary localized rectal gastrointestinal stromal tumors, especially for patients with rectal gastrointestinal stromal tumors ≤ 5 cm. See Video Abstract at http://links.lww.com/DCR/B764.

15.
Bioengineered ; 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34719328

RESUMO

Alzheimer's Disease (AD) is a neurodegenerative disease featured by cognitive impairment. This bioinformatic analysis was to identify hub genes related to cognitive dysfunction in AD. The gene expression profile GSE48350 in the hippocampus of AD patients aged >70y was obtained from the Gene Expression Omnibus (GEO) database. A total of 96 differentially expressed genes (DEGs) were identified, and subjected to Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses; a protein-protein interaction (PPI) network was constructed. The DEGs were enriched in synapse-related changes. A protein cluster was teased out of PPI. Furthermore, the cognition ranked the first among all the terms of biological process (BP). Next, 4 of 10 hub genes enriched in cognition were identified. The function of these genes was validated using APP/PS1 mice. Cognitive performance was validated by Morris Water Maze (MWM), and gene expression by RT-qPCR, Cholecystokinin (CCK), Tachykinin precursor 1 (TAC1), Calbindin 1 (CALB1) were downregulated in the hippocampus. These genes can provide new directions in the research the molecular mechanism of AD.

16.
Front Psychol ; 12: 674481, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34759854

RESUMO

"Zou Fan" is currently the largest "tree hole" on Weibo, where people having suicidal ideation often express their thoughts and use this channel to seek support. Therefore, early suicide monitoring and timely crisis intervention based on artificial intelligence technology are needed for this social media user group. This research was based on the knowledge graph technology, whereby "Tree Hole Intelligent Agent" (i.e., Artificial Intelligence Program) was used to identify "Zou Fan Tree Hole" users at high risk for suicide, and then, the "Tree Hole Action" carried out proactive suicide crisis intervention with them. The "Tree Hole Action" has temporarily prevented 3,629 potential suicides. The "Tree Hole Action" plays a significant role in suicide risk monitoring and crisis intervention for social media users and has been seen to have an important social impact.

17.
Sensors (Basel) ; 21(21)2021 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-34770728

RESUMO

With the rapid spreading of in-vehicle information systems such as smartphones, navigation systems, and radios, the number of traffic accidents caused by driver distractions shows an increasing trend. Timely identification and warning are deemed to be crucial for distracted driving and the establishment of driver assistance systems is of great value. However, almost all research on the recognition of the driver's distracted actions using computer vision methods neglected the importance of temporal information for action recognition. This paper proposes a hybrid deep learning model for recognizing the actions of distracted drivers. Specifically, we used OpenPose to obtain skeleton information of the human body and then constructed the vector angle and modulus ratio of the human body structure as features to describe the driver's actions, thereby realizing the fusion of deep network features and artificial features, which improve the information density of spatial features. The K-means clustering algorithm was used to preselect the original frames, and the method of inter-frame comparison was used to obtain the final keyframe sequence by comparing the Euclidean distance between manually constructed vectors representing frames and the vector representing the cluster center. Finally, we constructed a two-layer long short-term memory neural network to obtain more effective spatiotemporal features, and one softmax layer to identify the distracted driver's action. The experimental results based on the collected dataset prove the effectiveness of this framework, and it can provide a theoretical basis for the establishment of vehicle distraction warning systems.


Assuntos
Condução de Veículo , Aprendizado Profundo , Direção Distraída , Acidentes de Trânsito , Humanos , Redes Neurais de Computação
18.
BMC Oral Health ; 21(1): 576, 2021 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-34772397

RESUMO

BACKGROUND: Early childhood caries has been designated as a serious public health problem. The traditional restoration method is very challenging, especially in uncooperative patients. Non-invasive therapy, like remineralization agents, which have been developed to reverse the demineralization progress at the early stage of caries, may be a better choice. This study aimed to evaluate the remineralization efficacy of different concentrations of 45S5 bioactive glass (BAG) on artifical carious lesions of deciduous enamel. METHODS: 65 caries-like enamel lesions of the deciduous teeth were assigned to 5 groups (n = 13) and transported to a 14 days pH-cycling: Group A: 2%BAG, Group B: 4%BAG, Group C: 6%BAG, Group D: 8%BAG, and Group E: deionized water (DDW, negative control). 8 sound (Group F) and 8 demineralized teeth (Group G) were prepared for contrast. The recovery power of mechanical property was evaluated by Vickers hardness test through the recovery of enamel microhardness (%REMH). Surface morphology, mass fraction of Ca and P ions, and Ca/P atomic ratio were analyzed by scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (EDX). Moreover, Fourier transform infrared spectroscopy equipped with attenuated total reflectance was used to identify the chemical structure of newly formed compounds. RESULTS: % REMH were (42.65 ± 1.35), (52.59 ± 2.96), (57.40 ± 1.72), (52.91 ± 2.55), (12.46 ± 2.81) in 2%BAG, 4%BAG, 6%BAG, 8%BAG, and DDW groups respectively. Micro-spherical particles were deposited in all BAG groups and 6% BAG showed the densest and most uniform surface. EDX analysis identified significantly higher Ca(wt%) and P(wt%) in four BAG groups than in the demineralized group (p < 0.005), while 6% BAG showed the highest mineral gain efficacy. The infrared spectrum demonstrated that newly mineralized crystals were consisted of type-B hydroxycarbonate apatite. CONCLUSION: BAG possessed a promising remineralization effect on artificial lesions in deciduous enamel by recovering enamel surface mechanical property, morphology and chemical elements. Among them, 6% BAG performed the greatest overall efficacy. Acting as a new caries-arresting biomaterial, 45S5 BAG has the potential to facilitate the adaptation of better carious prevention strategies in children.

19.
Inflammation ; 2021 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-34792688

RESUMO

Intestinal inflammation is a common disease which can further lead to inflammatory bowel disease and even intestinal cancer. The increasing focus has come to the role of short-chain fatty acid (SCFA) in various bowel diseases. Hence, this study was designed to explore the specific role of SCFA in intestinal inflammation. In vivo and in vitro models of intestinal inflammation were constructed by lipopolysaccharide (LPS) injection in mice and LPS treatment on intestinal epithelial cells. A possible regulatory mechanism involving SCFA, CCAAT enhancer-binding protein beta (CEBPB), microRNA-145 (miR-145), and dual-specificity phosphatase 6 (DUSP6) in intestinal inflammation was verified by ChIP assay and dual-luciferase reporter gene assay. To evaluate the effects of SCFA on LPS-treated intestinal epithelial cells, the expression of relevant genes and inflammatory factors (IL-6, TNF-α, and IL-1ß) were determined. Last, the role of SCFA in vivo was explored through the scoring of disease activity index (DAI) and observation of colonic histology of LPS-treated mice. SCFA decreased the CEBPB expression in mouse colon tissues and small intestine epithelial cells induced by LPS. Furthermore, CEBPB could bind to the miR-145 promoter to inhibit its expression, thereby promoting the expression of DUSP6. In addition, SCFA improved the DAI, colonic histology, and the expression of serum inflammatory factors in LPS-treated mice and cells, noting that SCFA alleviated intestinal inflammation in vitro and in vivo. To sum up, SCFA inhibited DUSP6 by upregulating miR-145 through CEBPB repression and thus prevented the development of intestinal inflammation.

20.
Chemosphere ; : 132943, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34793842

RESUMO

Micro- and nano-plastics (MNPs) are increasingly prevalent pollutants in marine ecosystems and result in various deleterious effects on marine organisms. There have been studies evaluated the toxic effects of MNPs on marine microalgae, but few of them focused on the effects of MNPs on dinoflagellate species and their toxins production, which could have significant implications on human health and ecological safety in coastal areas. In this study, the common harmful algal blooms-causing dinoflagellate Alexandrium tamarense was exposed to 0.1 and 1 µm sized polystyrene nanoplastics (NPs) to investigate the responding patterns of population growth, multiple physiological functions, as well as the intracellular paralytic shellfish toxins (PSTs) productions. The results indicated the population growth, photosynthetic parameters, nutrients (nitrate and phosphate) uptake rates and extracellular carbonic anhydrase activities (CAext) were all inhibited by the two sized NPs, accompanied by the prolonged and more aggregated microalgal cells under the observation of scanning electron microscope (SEM), and the inhibition effects were more severe under 1 µm sized NPs than 0.1 µm sized NPs. Finally, we found the intracellular PSTs contents increased 73.59% exposed to 0.1 µm sized NPs while decreased 85.50% exposed to 1 µm sized NPs comparing the controls at 96 h, without significant changes of relative compositions. These results provided evidence that MNPs were toxic to A. tamarense and affected their intracellular PSTs productions within 96 h, which is critical to consider when evaluating the potential risks of MNPs in marine ecosystems.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...