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1.
J Chromatogr A ; : 460941, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32044124

RESUMO

Carbohydrates (such as levoglucosan) are a class of important water-soluble organic compounds in atmosphere. In this study, a high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) was applied to characterize carbohydrates in aerosol particles. Since carbohydrate was a kind of compound with low response in mass spectrometry, the conventional HPLC-MS/MS method was not sensitive enough to determine it. When acetate acid was added into mobile phase as buffer, the transition of [M+CH3COO]-→[M-H]- could be selected as the quantification ions. In the range from 1.0 µg L-1 to 20 µg mL-1, the coefficients of regression (r2) were more than 0.990, and relative standard deviations (RSD) for replicated injections were lower than 2%. The limit of detection (LOD) and quantification (LOQ) were lower than 2.5 ng L-1 and 10 ng L-1, respectively. The precision and accuracy were examined by spiked samples at three different concentration levels (10 µg L-1, 100 µg L-1, and 500 µg L-1) in five replicates. Recovery ratios ranged from 85% to 115% with RSD lower than 16%. Matrix effects of different carbohydrates ranged from 62% to 120%. The most sensitive HPLC-MS/MS method was developed and validated to analyze 40 aerosol samples successfully. The carbohydrates including three sugar alcohols (threitol, arabitol and sorbitol), one monosaccharide sugar (inositol), two disaccharides (sucrose, trehalose), one anhydrosugar (levoglucosan) and one 2-methyltetrols (2-Methylbutane-1,2,3,4-tretraol) were successfully quantified.

2.
J Clin Periodontol ; 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32031269

RESUMO

AIM: To identify risk variants associated with gene expression in peripheral blood and to identify genes whose expression change may contribute to the susceptibility to periodontitis. MATERIAL AND METHODS: We systematically integrated the genetic associations from a recent large-scale periodontitis GWAS and blood expression quantitative trait loci (eQTL) data using Sherlock, a Bayesian statistical framework. We then validated the potential causal genes in independent gene expression datasets. Gene co-expression analysis was used to explore the functional relationship for the identified causal genes. RESULTS: Sherlock analysis identified 10 genes (rs7403881 for MT1L, rs12459542 for SIGLEC5, rs12459542 for SIGLEC14, rs6680386 for S100A12, rs10489524 for TRIM33, rs11962642 for HIST1H3E, rs2814770 for AIM2, rs7593959 for FASTKD2, rs10416904 for PKN1, and rs10508204 for WDR37) whose expression may influence periodontitis. Among these genes, AIM2 was consistent significantly upregulated in periodontium of periodontitis patients across four datasets. The cis-eQTL (rs2814770, ~16 kb upstream of AIM2) showed significant association with AIM2 (P = 6.63 × 10-6 ) and suggestive association with periodontitis (P = 7.52 × 10-4 ). We also validated the significant association between rs2814770 and AIM2 expression in independent expression dataset. Pathway analysis revealed that genes co-expressed with AIM2 were significantly enriched in immune- and inflammation-related pathways. CONCLUSION: Our findings implicate that AIM2 is a susceptibility gene, expression of which in gingiva may influence periodontitis risk. Further functional investigation of AIM2 may provide new insight for periodontitis pathogenesis.

3.
J Cell Mol Med ; 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-32003123

RESUMO

Preeclampsia is a severe pregnancy-related disease that is found in 3%-5% of pregnancies worldwide and is primarily related to the decreased proliferation and invasion of trophoblast cells and abnormal uterine spiral artery remodelling. However, studies on the pathogenesis of placental trophoblasts are insufficient, and the aetiology of PE remains unclear. Here, we report that endothelial protein C receptor (EPCR), a transmembrane glycoprotein, was down-regulated in placentas from preeclamptic patients. Moreover, lack of EPCR significantly reduced the trophoblast cell proliferation, invasion and tube formation capabilities. Microscale thermophoresis analysis showed that EPCR directly bound to protease-activated receptor 1 (PAR-1), a G protein-coupled receptor. This change resulted in a substantial reduction in active Rac1 and caused excessive actin rearrangement. Our findings reveal a previously unidentified role of EPCR in the regulation of trophoblast proliferation, invasion and tube formation through promotion of actin polymerization, which is required for normal placental development.

5.
Artigo em Inglês | MEDLINE | ID: mdl-31961054

RESUMO

This study adopted the latest self-developed bioabsorbable material lactide-glycolide-1,3-trimethylene carbonate (LA-GA-TMC) and applied the three-dimensional (3D) printing technique to manufacture the occluder for cardiac septal defects, so as to realize the individualized treatment of cardiac septal defects. At the same time, its biosafety was evaluated, with an aim to establish foundation for futural large-scale animal experiment and clinical trial. The traditional "one-pot synthesis" was modified, and the "two-step synthesis method" was utilized to synthesize the LA-GA-TMC terpolymer at the lactide: glycolide: trimethylene carbonate ratio of 6:1:1.7. Afterward, the synthesized terpolymer was used as the raw material to fabricate the occluder model via using 3D printing technique. Then, its biocompatibility was comprehensively evaluated through cytocompatibility, blood compatibility, and histocompatibility. The occluder made from LA-GA-TMC 3D printing had favorable ductility and recoverability; besides, it possessed the temperature-control feature, and the relative cell proliferation rates in extract liquids at various concentrations were all >70%, suggesting that it had favorable cytocompatibility. Moreover, hemolytic experiment revealed that its hemolytic rate was <5%, dynamic blood coagulation experiment demonstrated that the sample material moderately activated the blood coagulation, and the above findings suggested that it had good blood compatibility. In addition, implanting experiment in vivo revealed that its histocompatibility was superior to the traditional nitinol and the emerging poly-l-lactic acid. It is completely feasible to manufacture the cardiac septal defects occluder based on the novel absorbable material LA-GA-TMC, which has favorable biocompatibility, through 3D printing technique and it possesses broad prospects in large-scale animal experiment and clinical trial.

7.
Food Chem Toxicol ; 137: 111126, 2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31954714

RESUMO

Syringic acid (SA), a natural polyphenol found in fruits and vegetables, is claimed to show notable hepatoprotection. Nevertheless, low solubility and bioavailability hamper the application of SA. This study aimed to investigate the potential of TPGS/F127/F68 mixed polymeric micelles as a sustained and liver-targeting nanocarrier for SA. Herein, the prepared SA-loaded TPGS/F127/F68 mixed polymeric micelles (SA-TPGS-Ms) were spherically-shaped and homogeneously-distributed nanoparticles with high entrapment efficiency (94.67 ± 2.05%) and sustained release. Besides, in-vitro cell culture studies revealed that SA-TPGS-Ms substantially promoted cellular uptake with excellent biocompatibility. After oral administration, SA-TPGS-Ms demonstrated an increased bioavailability (2.3-fold) and delayed in-vivo elimination compared with the free SA. Furthermore, the alleviation of oxidative stress and amelioration of hepatic injury in CCl4-induced hepatotoxicity mice further demonstrated the excellent hepatoprotection of SA-TPGS-Ms. Collectively, SA-TPGS-Ms could be a promising nanocarrier for the utilization of SA in functional foods, with enhanced bioavailability and hepatoprotection.

8.
J Org Chem ; 85(2): 622-632, 2020 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-31799847

RESUMO

An efficient Pd-catalyzed arylation of alkylpyridine based on the pyridinium activation strategy has been developed for synthesis of mixed aryl alkylpyridines. It was found that (1) the N-methyl group in the pyridinium salts acted as a transient activator and could be automatically departed after the reaction, (2) CuBr was an indispensable additive for achieving the C6-selective arylation, (3) the α-branched alkyl chain on the alkylpyridine greatly increased the yield of the product. Deuterium labelling experiment revealed that in the case of the α-branched alkylpyridine, the presence of CuBr completely inhibited the H/D exchange at the benzylic position and thus enabled the selective arylation at the C6 position. This protocol demonstrates a broad substrate scope, and with respect to both the aryl iodides and the α-branched alkylpyridine, the desired mixed aryl alkylpyridines were obtained in generally good to excellent yields.

9.
New Phytol ; 225(4): 1667-1680, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31581317

RESUMO

Seed vigour and early establishment are important factors determining the yield of crops. A wheat nitrate-inducible NAC transcription factor, TaNAC2, plays a critical role in promoting crop growth and nitrogen use efficiency (NUE), and now its role in seed vigour is revealed. A TaNAC2 regulated gene was identified that is a NRT2-type nitrate transporter TaNRT2.5 with a key role in seed vigour. Overexpressing TaNAC2-5A increases grain nitrate concentration and seed vigour by directly binding to the promoter of TaNRT2.5-3B and positively regulating its expression. TaNRT2.5 is expressed in developing grain, particularly the embryo and husk. In Xenopus oocyte assays TaNRT2.5 requires a partner protein TaNAR2.1 to give nitrate transport activity, and the transporter locates to the tonoplast in a tobacco leaf transient expression system. Furthermore, in the root TaNRT2.5 and TaNRT2.1 function in post-anthesis acquisition of soil nitrate. Overexpression of TaNRT2.5-3B increases seed vigour, grain nitrate concentration and yield, whereas RNA interference of TaNRT2.5 has the opposite effects. The TaNAC2-NRT2.5 module has a key role in regulating grain nitrate accumulation and seed vigour. Both genes can potentially be used to improve grain yield and NUE in wheat.

11.
Int J Pharm ; 574: 118939, 2020 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-31836485

RESUMO

Human epidermal growth factor receptor 2 (HER2) is an attractive target for cancer therapy, although a large fraction of tumors that express HER2 may still resist first-line therapies. Immunotoxins with antibodies that are armed with extremely potent cytotoxic toxin molecules may provide an important solution to this problem. In this work, we constructed three new anti-HER2 immunotoxins by using single-domain antibody (sdAb) molecules as the targeting moiety and the improved toxin PE24X7 as the effector with the aim of simplifying the preparation and reducing the off-target toxicity of the immunotoxins. Due to the beneficial outcomes of sdAb molecules, the synthesized immunotoxins were efficiently expressed in soluble form, avoiding the refolding process required by the common immunotoxin design and having high solubility and stability. Cell toxicity experiments showed that they have high cytotoxicity against various HER2-positive tumor cells and good selectivity (more than 1000-fold) towards HER2-positive rather than HER2-negative cells. Importantly, in vivo treatment experiments showed that one of the new immunotoxins could efficiently halt tumor growth at doses lower than 0.75 mg/kg, and it had a maximum tolerated dose (MTD) higher than 8.0 mg/kg, showing a substantially improved MTD and a broadened therapeutic window than the previously reported anti-HER2 immunotoxins. Given that PE toxin-based immunotoxins have been approved for clinical cancer therapy, the unique characteristics of the immunotoxins presented here make them promising for use in the development of anti-HER2 cancer therapeutics.

12.
Analyst ; 145(3): 701-718, 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-31844874

RESUMO

Light-up small molecule fluorescent dyes play an important role in modern analytical techniques, and they can be widely applied in biochemistry and biomedicine. Aptamers, including single-stranded ribonucleic acids and deoxyribonucleic acids, are molecules that have high affinity for, and can selectively bind to, a specific target, including ions, small molecules, cells, etc. Aptamers are selected in vitro using a process termed SELEX. Light-up dyes have excellent fluorogenic behavior because, although their baseline fluorescence is very low, their fluorescence quantum yield dramatically increases when they bind with a specific aptamer. Aptamer-dye pairs are used in biological imaging and chemical analysis because of their numerous advantages, including their low cost, small size, ease of modification, stability, and low immunogenicity. This paper reviews the progress that has been made in the selection of aptamers for use with light-up dyes and the applications of aptamer-based light-up dyes.

13.
Clin Exp Med ; 20(1): 109-119, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31845129

RESUMO

Carboxyl terminus of Hsc-70-interacting protein (CHIP), as U-box-type ubiquitin ligase, connects the chaperone and proteasome systems and plays a pivotal role in maintaining protein homeostasis in the cytoplasm. CHIP induces the ubiquitination and degradation of diverse oncogenic substrate proteins and therefore involves in the progression of tumorigenesis. In this study, the CHIP expression was examined in different human breast cancer cell lines and a group of breast cancer tissues. We found, for the first time, that CHIP expression was correlated with the molecular subtyping of breast cancer. CHIP was least expressed in the base-like subtype of breast cancer, which are triple-negative breast cancer (TNBC) breast cancer predominantly. Accordingly, CHIP expression was evidently decreased in the TNBC MDA-MB-231 breast cancer cell line. Enforced induction of CHIP in the MDA-MB-231 cells exerted no obvious influences on cellular growth and cell cycle. The apoptotic and proliferation cells in hCHIP cells were both reduced compared to the ctrl cells. The mRNA and protein expressions of the anti-apoptotic Bcl-2 and Bcl-xL were markedly increased in the hCHIP cells compared to that of the ctrl cells. The expression of RelA was significantly reduced in the nuclear extract in hCHIP cells compared to that in the ctrl cells. The protein expressions of IKKß were markedly decreased in the hCHIP cells compared to the ctrl cells. The reduced cellular proliferation was largely due to the attenuated IKKß-p65/NF-κB activity. Meanwhile, the invasion ability but not the migration ability was diminished when CHIP was overexpressed in the MDA-MB-231 cells. The activity of MMP2 but not MMP9 was significantly decreased in the hCHIP cells compared to the ctrl cells. Taken together, these observations here provide functional evidence for CHIP behaved as a tumor suppressor in the TNBC breast cancer cells. CHIP influenced diverse biological aspects of the MDA-MB-231 breast cancer cells. Importantly, CHIP expression is a useful indicator of the molecular subtyping of breast cancer.

14.
Int J Mol Sci ; 20(24)2019 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-31817978

RESUMO

Citrus fruits are mainly consumed as fresh fruit and processed juice products. They serve as nutritional and a tasty diet in our daily life. However, the formidable bitterness and delayed bitterness significantly impact the citrus industry attributable to the two major bitter compounds naringin and limonin. The extremely sour and acidic also negatively affects the sensory quality of citrus products. Citrus breeding programs have developed different strategies to improve citrus quality and a wealth of studies have aimed to uncover the genetic and biochemical basis of citrus flavor. In this minireview, we outline the major genes characterized to be involved in pathways shaping the sweet, bitter, or sour taste in citrus, and discuss briefly about the possible approaches to modify citrus taste by genetic engineering.

15.
J Periodontol ; 2019 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-31833563

RESUMO

BACKGROUND: Each genetic variant individually explains only a tiny proportion of the genetic variation with insignificant predictive power. The tool of multi-locus genetic risk score (GRS), which aggregates information from multiple genetic variants, has been widely used in many complex diseases but not yet applied to generalized aggressive periodontitis (GAgP). METHODS: A total of 335 GAgP patients and 114 healthy controls were enrolled in the case-control study. The unweighted GRS (uGRS) and weighted GRS (wGRS) were calculated based on significant variants. Logistic regression models were conducted for the GRS-based association analyses on the risk of GAgP. Receiver operating characteristic analysis was performed to compare the discriminatory ability of predictors of GAgP risk. RESULTS: Four loci were found to be significantly associated with GAgP. They were matrix metalloproteinase 8 rs11225395 (odds ratio [OR] = 1.40, 95% CI: 1.03 to 1.91), epidermal growth factor rs2237051 (OR = 1.41, 95% CI: 1.03 to 1.93), PPAR-a rs4253623 (OR = 1.53, 95% CI: 1.03 to 2.26), and apolipoprotein E rs429358 (OR = 1.79, 95% CI: 1.08 to 2.97). Each additional point of the uGRS/wGRS was associated with a 50%/31% increased risk of developing GAgP (OR = 1.50, 95% CI: 1.21 to 1.85 or OR = 1.31, 95% CI: 1.14 to 1.51, respectively) after adjusting for age, sex, and body mass index (BMI). Participants in the high group of uGRS/wGRS (OR = 2.87, 95% CI: 1.59 to 5.17 or OR = 2.67, 95% CI: 1.46 to 4.88, respectively) and the middle group of uGRS/wGRS (OR = 2.21, 95% CI: 1.29 to 3.78 or OR = 1.88, 95% CI: 1.09 to 3.08, respectively) had an increased risk of GAgP compared with those in the low group of score after adjustment for age, sex, and BMI. The addition of GRS to a model of conventional risk factors improved discrimination by 4.5% (from 0.695 to 0.740, P = 0.048). CONCLUSIONS: We demonstrated that the multi-locus GRS based on four significant single nucleotide polymorphisms might be useful to assess genetic predisposition to GAgP. The GRS in combination with conventional risk factors significantly improved the power of identifying subgroups of Chinese population with a particularly high risk for GAgP.

16.
Aust Health Rev ; 2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31837712

RESUMO

ObjectiveYoung adults aged 18-24 years often delay or avoid seeking help for their mental health concerns. eMental health, the use of the Internet to deliver mental health information, services and care, offers a low-cost, easy-access option. However the factors that influence online help-seeking among this cohort remain unclear.MethodsAndersen's healthcare utilisation model was adapted to examine correlates of eMental health use among Australian youth. In all, 161 young adults completed an online survey comprising sociodemographic questions, online feature preferences, the Actual and General Help-seeking Questionnaires, Berkman-Syme Social Network Index, General Self-Efficacy Scale, Service Obstacles Scale and Depression, Anxiety and Stress Scales.ResultsAlmost 70% of young people reported having previously accessed some form of online support for their personal or emotional problems. This included informal information via social media and formalised counselling services. Notably, perception of service satisfaction was low. Hierarchical logistical regression identified two significant predisposing factors to subsequent online help-seeking: prior face-to-face service use and living or cohabitating with others.ConclusionseMental health is accessed by young people in Australia, yet more needs to be done to better integrate this service model into the healthcare system. This includes training and education for consumers and professionals about existing, effective programs.What is known about this topic?eMental health platforms can bridge the gap between technology and conventional mental health care. Despite its rapidly expanding evidence base, the implementation of eMental health into the Australian healthcare system remains slow. More work needs to be done to elucidate the factors underlying preferences for online help-seeking.What does this paper add?Young adult perspectives on the delivery of mental health information, services and care via the Internet are examined in accordance with a major conceptual model, namely Andersen's behavioural model of health services use. The majority of those surveyed reported having accessed some form of online support for an emotional issue, although dissatisfaction with the quality of this support was expressed. Andersen's model can guide future research in this area and potentially help target eMental health initiatives to individual service users' needs.What are the implications for practitioners?eMental health interventions offer an alternative for young adults who have difficulty accessing traditional mental health care services, but are also an adjunct to those experiencing mild to moderate symptoms of mental illness. Practitioners can introduce young adults to eMental health by discussing the benefits and limitations and by providing information about available and secure online programs delivered by trusted service providers.

17.
Arthritis Rheumatol ; 2019 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-31872544

RESUMO

OBJECTIVE: This study aimed to investigate the role of an inflammatory lipid mediator, leukotriene B4 (LTB4 ), and its receptor BLT1 in systemic sclerosis (SSc). METHODS: Serum levels of LTB4 were compared in 64 subjects with SSc and 80 healthy controls (HC). Skin and lung sections were immunostained with leukotriene A4 hydrolase (LTA4 H), the critical enzyme for LTB4 synthesis, and BLT1, in combination with different cell markers. The LTB4 -BLT1 axis was genetically or pharmacologically interrupted in mouse models of SSc induced by bleomycin or angiotensin II, or immunized with the DNA topoisomerase I. Immunoblotting was performed to examine the signaling pathway in fibroblasts and endothelial cells following stimulation with LTB4 or the serum from SSc patients. RESULTS: 44.93% higher serum LTB4 levels were detected in patients with SSc than matched HCs (220.3±74.75 vs 152.0±68.05 pg/ml, p<0.0001), associated with interstitial lung disease (ILD) and diffuse cutaneous subset. LTA4 H and BLT1 were increased in lesional skin and lung areas from SSc, and abundant in myofibroblast and endothelial cells. Interruption of the LTB4 -BLT1 axis significantly mitigated dermal and pulmonary fibrosis, with 54.00% and 52.65% fewer α-SMA+ myofibroblast accumulation of skin and lungs respectively after bleomycin challenging. Recombinant LTB4 or the serum of SSc patients promoted fibroblast-myofibroblast and endothelial-mesenchymal transitions via BLT1, which was dependent on activation of the PI3K/Akt/mTOR pathway, but independent of TGF-ß release by fibroblasts or endothelial cells. CONCLUSION: The LTB4 -BLT1 axis may contribute to fibrosis in SSc by directly promoting myofibroblast differentiation via the PI3K/Akt/mTOR pathway, independently of TGF-ß autocrine secretion.

18.
Med Sci Monit ; 25: 10016-10028, 2019 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-31877561

RESUMO

BACKGROUND Dental pulp cells (DPCs) play vital roles in the recovery of dental pulp tissue. Concentrated growth factor (CGF) can promote proliferation and mineralization of various cells. However, the functions of CGF on DPCs and dental pulp tissue are unclear. The object of our study was to identify the roles of CGF in DPCs proliferation and mineralization in vitro and to assess the effects of CGF on direct pulp capping in vivo. MATERIAL AND METHODS We performed CCK-8 and Transwell assay to detect proliferation and migration activity of DPCs. Alizarin Red staining was performed to examine mineralized nodules. Alkaline phosphatase activity test was used to measure the mineralization capacity of DPCs. We assessed the odontogenic differentiation gene expression level by Western blot and qPCR. The effect of CGF on direct pulp capping in vivo were evaluated by radiography and histopathology. RESULTS CGF increased the number of proliferative and migratory DPCs. CGF enhanced DPCs mineralized nodules and improved the gene expression levels of DSPP, DMP-1, BSP, and ALP. CGF upregulated the protein levels of ALP, BMP2, SMAD5, Runx2, and p-Smad, and the effect could be partially reversed by Noggin. CGF promoted pulp recovery and kept its vitality in directly pulp capping. CONCLUSIONS CGF promotes DPCs proliferation and mineralization. It regulates the mineralization of DPCs via the BMP2/SMAD5/Runx2 signaling pathway. CGF can be used as the effective graft for direct pulp capping.

19.
Huan Jing Ke Xue ; 40(10): 4440-4449, 2019 Oct 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854811

RESUMO

In order to research the impact of continuous extreme rainfall on the water quality of the Dongjiang River, which is a drinking water source, the characteristics of extreme rainfall events in the basin were analyzed for last 38 years. The impacts of these events on water quality are discussed by considering both hydrological data and water quality data. Using SWAT2012 software, a high-precision basin model was established for the flux of major pollutants during extreme rainfall and water quality. The results indicate that there were 173 extreme rainfall events in the Dongjiang River basin over the past 38 years. The annual frequency of extreme rainfall events in high-flow years was higher than in other years. During the year, rainfall was mainly affected by climate, particularly from March to September (80%), with the peak rainfall usually occurring in June. Spatially, the Zengcheng-Bolo-Huizhou-Longmen area had the highest frequency of extreme events. During the study period, rainfall was significantly positively correlated with the concentrations of cyanide, Pb, Fe, Mn, TP, and with turbidity, and the correlation coefficients for the concentrations of TP and turbidity with rainfall were relatively high. Rainfall was significantly negatively correlated with pH, conductivity, the concentration of Zn, as well as some other indicators. These observations show that water quality is affected by rainfall to some extent. Turbidity, TN, ammonia nitrogen, and TP concentrations all showed increasing trends, to different degrees, during rainstorm runoff periods. Turbidity and TP concentrations showed a significant and consistent relationship with flow rate, peaking earlier than the flow rate peak (by approximately 1 d), showing a significant initial flushing effect. The pH curve showed an opposite trend to the flow rate, forming a "V" shape, which may be affected by the rainfall, soil acidity, and confluence conditions in the upstream mountains. Ammonia nitrogen was subject to initial flushing in the early stages of extreme rainfall but was diluted by the clean rainwater; initially, ammonia nitrogen showed high values that declined during the middle and late stages. The variations in pollutant loads were consistent with that of runoff flux, and the peaks in TN, ammonia nitrogen, and TP flux appeared later than the flow peak (by approximately 1 d), thus differing from the pollutant concentration peak. The pollutant load mainly showed a significant increase during storm runoff periods. The proportion of pollutant COD, ammonia nitrogen, and TP transported by 59.48% of the runoff reached 68.42%, 54.68%, and 70.20%, respectively, demonstrating the characteristics of rapid and high-impact pollutant loads. These characteristics have a great influence on the quality of Dongjiang River drinking water and it is suggested that initial rainwater treatment should be strengthened to reduce the negative impact of rainstorm runoff periods on water quality.

20.
PeerJ ; 7: e7828, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31772831

RESUMO

Objective: To investigate the correlation between the single nucleotide polymorphisms (SNPs) in the toll-like receptor 4 (TLR4) gene and the susceptibility to chronic periodontitis. Design: 241 Chinese subjects from the cohort of Beijing Shijingshan Community were recruited. Buccal swab samples, the whole unstimulated saliva and periodontal clinical parameters were collected. Human DNA extracted from buccal swab samples were used for genotyping eight SNPs of the TLR4 gene (rs11536889, rs1927906, rs1927911, rs2149356, rs4986790, rs4986791, rs2737190, rs787384) by the Sequenom MassARRAY system. Porphyromonas gingivalis (P. gingivalis) was detected from the deposition of the whole unstimulated saliva through polymerase chain reaction (PCR) method based on 16S rRNA. The correlation between SNPs of TLR4 and chronic periodontitis susceptibility in the whole subjects and the patients detected with P. gingivalis was investigated. Results: The variants of rs4986790 and rs4986791 were not found in 241 Chinese subjects. Moreover, there was no significant difference in the distribution of theother6 SNPs of TLR4 between groups of none/mild -periodontitis and moderate/severe-periodontitis subjects. When combined with P. gingivalis infection, rs1927911 (TT/CC+CT), rs2149356 (TT/GG+GT) and rs2737190 (GG/AA+AG) were independent risk factors of chronic periodontitis. Conclusion: Three SNPs of TLR4, i.e., rs1927911 (TT/CC+CT), rs2149356 (TT/GG+GT) and rs2737190 (GG/AA+AG), were associated with moderate/severe chronic periodontitis in Chinese population infected with P. gingivalis. P. gingivalis, which interacted with TLR4 gene plays an important role in the pathogenesis of periodontitis.

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