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1.
Chemosphere ; 239: 124703, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31526999

RESUMO

In recent years, precise environment supervision has gradually become vital in water pollution control, which requires the clear identification of dissolved organic matters (DOM) in wastewater. Metalworking fluid (MWF) is a type of wastewater with high toxicity. Over ten million m3 of MWF is discharged per year. However, its DOM characteristics have not yet been systematically investigated. Therefore, in this study, the fluorescent DOM (FDOM) of MWF was firstly characterized by excitation-emission matrix-parallel factor analysis (EEM-PARAFAC) and high-performance liquid chromatography (HPLC). Three fluorescent components (C1-C3) of the MWF from three metalworking plants (BO, TH, and YD) were identified. The peaks measured for C1 and C3 were attributed to tryptophan-like (Peak T) and humic/fulvic acid-like (Peak A + C) peaks, respectively, and the peaks at C2 were identified as humic-like (Peak A + M) or tryptophan-like (Peak T) peaks. There were differences in the C2 and C3 components of MWF from the three metalworking plants. The FDOM of MWF from the three metalworking plants exhibited similar polarity, but different apparent molecular weight distributions. In addition, the highest intensities of the three fluorescent peaks were sensitive to variations in the pH, humic acid (HA) concentrations, and metal ion levels (Cu2+, Fe3+, and Ni2+). The findings of this study not only indicate the FDOM characteristics of MWF, but also provide a promising method and valuable guidance for the practical monitoring of MWF in natural water bodies.

2.
J Cell Biochem ; 121(1): 867-875, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31452270

RESUMO

Long noncoding RNAs (lncRNAs) are linked to tumor development and progression. The aim of this study was to determine the prognostic significance and biological role of LINC01116 in head and neck squamous cell carcinoma (HNSCC). We identified 21 aberrantly expressed lncRNAs specific to HNSCC that were common in two microarray datasets. LINC01116 was highly overexpressed in HNSCC tissues and was correlated to shorter overall survival and relapse-free survival duration, as analyzed by the online Gene Expression Profiling Interactive Analysis platform. LINC01116 was also overexpressed in oral squamous cell carcinoma and nasopharyngeal carcinoma tissues, and LINC01116 silencing significantly inhibited the migration and invasion capacities of both cell lines by blocking the epithelial-mesenchymal transition process. In addition, 125 coexpressing genes were identified by circlncRNAnet, and were mainly located on human autosomes and enriched in transforming growth factor-ß signaling pathway. These findings indicate that LINC01116 might be a potential therapeutic target for HNSCC.

3.
Toxicol In Vitro ; 62: 104698, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31669364

RESUMO

Both PM2.5 and respiratory viruses are part of the atmospheric constituents. Respiratory viruses are often associated with PM2.5 exposure, but the mechanism of toxicity remains to be explored. The vitro models that adequately reproduce healthy cells or diseased cells exposing to PM2.5 and infecting VSV can provide a useful tool for studying innate immune mechanisms and investigating new therapeutic focus. In the environment of PM2.5, an infection model in which VSV infected A549 cells was established, that mimics the state in which the antiviral innate immune pathways are activated after the respiratory system is infected with RNA viruses. Subsequently, the model was exposed to PM2.5 for 24 h. PM2.5 could be ingested by A549 cells and synergize with VSV to inhibit cell viability and promote apoptosis. The expression of VSV-G were more abundant after VSV-infected A549 cells were exposed to PM2.5. Furthermore, PM2.5 inhibits VSV-induced IFN-ß expression in A549 cells. ISG15, CCL-5, and CXCL-10 had the same expression tendency with IFN-ß mRNA, consistently. Interestingly, when MG132 was applied, the expression of p-IRF-3 and IFN-ß proteins reduced by PM2.5 were refreshed. Conversely, the expression of VSV-G proteins were decreased. PM2.5 could degrade p-IRF-3 proteins by ubiquitination pathway to inhibit VSV-induced IFN-ß expression in A549 cells. Therefore, replication of the VSV viruses was promoted.

4.
Public Health Nutr ; : 1-12, 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31685051

RESUMO

OBJECTIVE: The present study investigated the association between dietary patterns and hypertension applying the Chinese Dietary Balance Index-07 (DBI-07). DESIGN: A cross-sectional study on adult nutrition and chronic disease in Inner Mongolia. Dietary data were collected using 24 h recall over three consecutive days and weighing method. Dietary patterns were identified using principal components analysis. Generalized linear models and multivariate logistic regression models were used to examine the associations between DBI-07 and dietary patterns, and between dietary patterns and hypertension. SETTING: Inner Mongolia (n 1861). PARTICIPANTS: A representative sample of adults aged ≥18 years in Inner Mongolia. RESULTS: Four major dietary patterns were identified: 'high protein', 'traditional northern', 'modern' and 'condiments'. Generalized linear models showed higher factor scores in the 'high protein' pattern were associated with lower DBI-07 (ßLBS = -1·993, ßHBS = -0·206, ßDQD = -2·199; all P < 0·001); the opposite in the 'condiments' pattern (ßLBS = 0·967, ßHBS = 0·751, ßDQD = 1·718; all P < 0·001). OR for hypertension in the highest quartile of the 'high protein' pattern compared with the lowest was 0·374 (95 % CI 0·244, 0·573; Ptrend < 0·001) in males. OR for hypertension in the 'condiments' pattern was 1·663 (95 % CI 1·113, 2·483; Ptrend < 0·001) in males, 1·788 (95 % CI 1·155, 2·766; Ptrend < 0·001) in females. CONCLUSIONS: Our findings suggested a higher-quality dietary pattern evaluated by DBI-07 was related to decreased risk for hypertension, whereas a lower-quality dietary pattern was related to increased risk for hypertension in Inner Mongolia.

5.
Environ Pollut ; 255(Pt 1): 113129, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31669826

RESUMO

The airborne occurrence, isomer profiles, and phase distribution of perfluoroalkyl acids (PFAAs), including perfluoroalkyl carboxylates (PFCAs) and sulfonates (PFSAs), have received little scientific attention to date. Here we collected gaseous and particulate phase (PM2.5) samples in China, between June and November 2013, using alkalized annular denuders and downstream filters toavoid sampling artefacts associated with traditional air sampling. We analysed the concentrations of 18 linear PFAAs and the branched isomers of perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS). Concentrations of total PFAAs were dominated by PFCAs, with a range of 6.6-610 pg/m3 in the gaseous phase and 2.3-290 pg/m3 in the particulate phase. Concentrations of total PFCAs were higher in summer than winter in both phases. Branched PFOA isomers accounted for 10-22% of total PFOA in the gaseous phase and 13-24% in the particulate phase, which is close to, but slightly lower than, their abundance in the commercial PFOA mixtures manufactured using the electrochemical fluorination (ECF) process. In contract, branched PFOS isomers accounted for 26-63% of total PFOS in the gaseous phase and 39-77% in the particulate phase, which is much higher than their abundance in commercial PFOS mixtures manufactured by ECF. Most PFCAs had mean particle-associated fractions (Φ) higher than 0.5. PFHxS had a much higher mean Φ (0.65) than linear PFOS (0.31). We hypothesise that PFAAs observed in Beijing air may originate from the local water bodies through processes such as aerosol generation, although transformation of precursors also contribute.

6.
BMJ Open ; 9(11): e031443, 2019 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-31712338

RESUMO

OBJECTIVE: Microalbuminuria (MAU) has been described as a risk factor for metabolic syndrome (MetS). However, the association between MetS components with MAU and 24-hour urinary albumin excretion (UAE) has not been clearly explained in the general Chinese population. We aimed to analyse the associations between MAU and high-normal 24-hour UAE with MetS and its components. DESIGN: Cross-sectional observational study. SETTING: Four selected counties/districts in China's Shandong and Jiangsu Provinces. PARTICIPANTS: A total of 2261 participants aged 18-69 years were included in this study. Participants with missing physical examination data or incomplete urine collection were not included in the analysis. RESULTS: The prevalence of MAU was 9%, and the mean 24-hour UAE was 18 mg/d. The prevalence of MAU was significantly higher for the MetS, high blood pressure (BP), high triglyceride (TG) levels, low high-density lipoprotein cholesterol (HDL-C) and hyperglycaemia groups but not for the central obesity group. Both MAU and mean 24-hour UAE were significantly increased in association with a number of MetS components. The adjusted prevalence OR (POR) for MetS with MAU was 2.95 (95% CI 2.15 to 4.04) compared with those without MAU. MAU was significantly associated with three components of MetS: high BP (POR=1.86, 95% CI 1.31 to 2.64), high TG levels (POR=1.80, 95% CI 1.31 to 2.46) and hyperglycaemia (POR=1.84, 95% CI 1.34 to 2.53). No significant association between MAU and central obesity or low HDL-C was found. The presence of MetS gradually increased according to the normal-range 24-hour UAE quartiles: POR=1.00, POR=1.22, POR=1.14 and POR=2.02, respectively. Hyperglycaemia also increased significantly according to the normal-range 24-hour UAE quartiles. CONCLUSIONS: MAU and elevated 24-hour UAE within the normal range were closely associated with MetS in the Chinese population, which may provide a basis for the development of early interventions to decrease the effects of MetS.

7.
J Toxicol Environ Health A ; 82(18): 990-996, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31679505

RESUMO

Long-term exposure to sodium arsenite was found to induce malignant transformation in human bronchial epithelial (HBE) cell line as evidenced by elevated ROS levels. Although chronic sodium arsenite-induced HBE cell line transformation was associated with elevated ROS generation, it was of interest to determine whether acute sodium arsenite exposure also initiated pulmonary damage. Thus, the aim of this study was to investigate oxidative-stress-related pulmonary damage using a human bronchial epithelial (HBE) cell line. Incubation of ρ+-HBE (in the presence of mitochondrial DNA) cells with various concentrations of sodium arsenite, significantly increased ROS and MDA levels accompanied by decreased SOD activity in a concentration-dependent manner. In contrast, treatment of ρ-HBE (without mitochondrial DNA) cells various concentrations of sodium arsenite a reduction in ROS and MDA levels were noted. However, the SOD activity remained decreased in ρ-HBE cells. This was accompanied by a significant rise in HO-1 protein expressions levels in both cell types with greater changes ρ-HBE cells at the lower sodium arsenite concentrations. Data indicate that acute sodium arsenite exposure exerted a greater effect ρ-HBE cells suggesting that absence of mitochondrial DNA appears to enhance sensitivity to the oxidant actions of inorganic As.

8.
Stat Med ; 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31691322

RESUMO

In longitudinal clinical trials, it is common that subjects may permanently withdraw from the study (dropout), or return to the study after missing one or more visits (intermittent missingness). It is also routinely encountered in HIV prevention clinical trials that there is a large proportion of zeros in count response data. In this paper, a sequential multinomial model is adopted for dropout and subsequently a conditional model is constructed for intermittent missingness. The new model captures the complex structure of missingness and incorporates dropout and intermittent missingness simultaneously. The model also allows us to easily compute the predictive probabilities of different missing data patterns. A zero-inflated Poisson mixed-effects regression model is assumed for the longitudinal count response data. We also propose an approach to assess the overall treatment effects under the zero-inflated Poisson model. We further show that the joint posterior distribution is improper if uniform priors are specified for the regression coefficients under the proposed model. Variations of the g-prior, Jeffreys prior, and maximally dispersed normal prior are thus established as remedies for the improper posterior distribution. An efficient Gibbs sampling algorithm is developed using a hierarchical centering technique. A modified logarithm of the pseudomarginal likelihood and a concordance based area under the curve criterion are used to compare the models under different missing data mechanisms. We then conduct an extensive simulation study to investigate the empirical performance of the proposed methods and further illustrate the methods using real data from an HIV prevention clinical trial.

9.
Artigo em Inglês | MEDLINE | ID: mdl-31702013

RESUMO

CONTEXT: Gonadotropin-releasing hormone analogues (GnRHa) and recombinant human growth hormone (rhGH) have been widely used to treat idiopathic central precocious puberty (CPP) or early and fast puberty (EFP). However, large-scale studies to evaluate the treatment effects on final adult height (FAH) are still lacking. OBJECTIVE: To assess the effects of long-term treatment for CPP/EFP on FAH and its main influencing factors. DESIGN AND SETTING: Retrospective, multi-center observational study from 1998-2017. PARTICIPANTS: Four hundred forty-eight Chinese girls with CPP/EFP received GnRHa and rhGH treatment (n=118), GnRHa alone (n=276), or no treatment (n=54). MAIN OUTCOME MEASURES: FAH, target height (Tht), and predictive adult height (PAH). RESULTS: The height gain (FAH-PAH) was significantly different among the GnRHa and rhGH treatment, GnRHa alone, and no treatment groups (p<0.05; 9.51±0.53, 8.07±0.37, and 6.44±0.91 cm, respectively). The genetic height gain (FAH-Tht) was 4.0±0.5 cm for the GnRHa+rhGH group and 2.0±0.27 cm for the GnRHa group, while the control group reached their Tht. In addition, five critical parameters derived from PAH, bone age, and Tht, showed excellent performance in predicting which patients could gain ≥5 cm (FAH-PAH), and this was further validated using an independent study. CONCLUSIONS: The overall beneficial effect of GnRHa+rhGH or GnRHa on FAH was significant. The control group also reached their genetic target height. Clinicians are recommended to consider both the potential gains in height and the cost of medication.

10.
Ecotoxicol Environ Saf ; 188: 109895, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31706238

RESUMO

Seventeen soil samples collected in an industrial park located in Ningxia Province, Northwestern China were analyzed for polychlorinated naphthalenes (PCNs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and polychlorinated biphenyls (PCBs). The PCN, PCDD/F, and PCB concentration ranges were 183-3340, 7.00-215, and 45.1-355 pg/g, respectively. Positive matrix factorization showed that secondary ferrous metal smelters and cement kilns contributed more than 70% of the total PCN concentration. Historical use of Halowax 1051 also affected the PCN concentrations in soil. Principal component analysis indicated that the PCDD/F concentrations in soil in the study area were mainly affected by thermal processes in secondary ferrous metal smelters. CB-209 was an important contributor to total PCBs in the study area, and likely originated from the phthalocyanine-type pigments used in a local recycled paper mill. Samples S10, S1, S17, and S6 had high ∑TEQ (PCDD/Fs + PCNs + PCBs) concentrations, and the carcinogenic risks of PCDD/Fs, PCNs, and PCBs for workers from these samples were 0.487 × 10-6, 0.234 × 10-6, 0.230 × 10-6, and 0.210 × 10-6, respectively. According to our results, the health risks of PCDD/Fs, PCNs, and PCBs for workers in this area should be given more attention.

11.
Int J Biol Macromol ; 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31712143

RESUMO

Resistant starch (RS) is helpful in controlling and preventing metabolic syndrome relevant diseases. However, the RS content of natural starch and modified starch produced by enzymatic method is generally low. To solve this problem, we selected the glycogen branching enzyme from Vibrio vulnificus (VvGBE) and investigated its application. Firstly, it was expressed in E. coli with the enzyme activity was 53.33 U/mL, and its optimum temperature and pH was 35 °C and 7.5, respectively. The half-life of VvGBE at 35 °C was 10 h, and the enzyme was most stable at pH 9.5. When we used the recombinant enzyme to treat corn starch, the content of RS increased by 19.41%, which was higher than that achieved with other enzymes. More specially, the conversion of slowly digestible starch to RS, which was only demonstrated in chemical modification, was accomplished. The fine structure of the modified starch was further investigated. Results showed that the number of short chains (DP < 13) increased to 90.58%, and the α-1,6 linkages ratio increased from 7.19% to 15.64%. The increase of short chains and α-1,6 linkages may contribute to high RS content. This study can provide a reference for the development of modified starch with lower digestibility.

12.
Aust N Z J Psychiatry ; : 4867419885443, 2019 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-31735061

RESUMO

OBJECTIVES: Large-scale genetic analysis of common variation in schizophrenia has been a powerful approach to understanding this complex but highly heritable psychotic disorder. To further investigate loci, genes and pathways associated more specifically in the well-characterized Australian Schizophrenia Research Bank cohort, we applied genome-wide single-nucleotide polymorphism analysis in these three annotation categories. METHODS: We performed a case-control genome-wide association study in 429 schizophrenia samples and 255 controls. Post-genome-wide association study analyses were then integrated with genomic annotations to explore the enrichment of variation at the gene and pathway level. We also examine candidate single-nucleotide polymorphisms with potential function within expression quantitative trait loci and investigate overall enrichment of variation within tissue-specific functional regulatory domains of the genome. RESULTS: The strongest finding (p = 2.01 × 10-6, odds ratio = 1.82, 95% confidence interval = [1.42, 2.33]) in genome-wide association study was with rs10252923 at 7q21.13, downstream of FZD1 (frizzled class receptor 1). While this did not stand alone after correction, the involvement of FZD1 was supported by gene-based analysis, which exceeded the threshold for genome-wide significance (p = 2.78 × 10-6). CONCLUSION: The identification of FZD1, as an independent association signal at the gene level, supports the hypothesis that the Wnt signalling pathway is altered in the pathogenesis of schizophrenia and may be an important target for therapeutic development.

13.
Mol Cell ; 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31735641

RESUMO

Macrophages form a major cell population in the tumor microenvironment. They can be activated and polarized into tumor-associated macrophages (TAM) by the tumor-derived soluble molecules to promote tumor progression and metastasis. Here, we used comparative metabolomics coupled with biochemical and animal studies to show that cancer cells release succinate into their microenvironment and activate succinate receptor (SUCNR1) signaling to polarize macrophages into TAM. Furthermore, the results from in vitro and in vivo studies revealed that succinate promotes not only cancer cell migration and invasion but also cancer metastasis. These effects are mediated by SUCNR1-triggered PI3K-hypoxia-inducible factor 1α (HIF-1α) axis. Compared with healthy subjects and tumor-free lung tissues, serum succinate levels and lung cancer SUCNR1 expression were elevated in lung cancer patients, suggesting an important clinical relevance. Collectively, our findings indicate that the secreted tumor-derived succinate belongs to a novel class of cancer progression factors, controlling TAM polarization and promoting tumorigenic signaling.

14.
Biotechnol Adv ; : 107496, 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31756374

RESUMO

Amino acids (AAs), which contain various functional groups including α-amino group, α-carboxyl group, and certain specific side-chains, exhibit a wide range of chemical properties. The derivatization of these functional groups of AAs via biocatalysis represents a sustainable approach for producing various chemicals, such as α-keto acids, α-hydroxyl acids, non-proteinogenic AAs, amines, peptides, higher alcohols, and phenylpropanoids, that are valuable in the pharmaceutical, chemical synthesis, cosmetic, and food industries. Here, we review recent advances in the derivatization of AAs to describe the design of derivatization reactions, how to overcome technical bottlenecks, and the potential range of chemicals that may be obtained. Furthermore, we highlight future prospects and address the challenges that remain in the derivatization of AAs for the production of fine chemicals.

15.
Sci Total Environ ; 694: 133775, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31756802

RESUMO

The lab-scale system combined bioelectrochemical and sulfur autotrophic denitrification (CBSAD) was established to evaluate the effects of currents (50-300 mA) on both the performances and microbial communities. Results showed that the nitrate removal rate increased significantly when the current increased from 50 to 200 mA, while it slightly decreased with higher currents. Mass balance results revealed that hydrogen autotrophic denitrification contributed almost three times (70.25-78.62%) to denitrification compared with that of the sulfur part (21.38-29.75%). Illumina MiSeq sequencing showed that the currents changed the bacterial richness and diversity in this system. Phylum Firmicutes and class Clostridia predominated >50% under each condition. And multiple key bacteria capable of denitrification such as Proteiniclasticum, Thauera and Family_XI_uncultured were identified and found in higher proportions when the current was 200 mA. Therefore, this study helps revealing the mechanisms of accelerating nitrate-reduction through applied currents in the CBSAD systems.

16.
Artigo em Inglês | MEDLINE | ID: mdl-31758236

RESUMO

Cyclodextrin glycosyltransferases (CGTases) are widely used in starch deep processing, so reducing their cost by improving their production is of significant industrial interest. The CGTase from Bacillus stearothermophilus NO2 possesses excellent catalytic properties but suffers from low production in E. coli. In this study, directed evolution was used to create three point mutants (I631T, I641T and K647E) that were produced in E. coli with shake-flask yields 1.7-, 2.1-, and 2.2-fold higher than that of wild-type, respectively. The wild-type and K647E were then produced in a 3-L fermenter. The CGTase activity of the K647E (1904 U mL-1) was 2.0-fold higher than that of the wild-type. The K647E fermentation supernatant could be used directly to prepare 2-O-α-D-glucopyranosyl-L-ascorbic acid, reducing the costs associated with its production. Structural modeling of the three mutants suggested that hydrophilicity, hydrogen bonding, and negative charge may be responsible for their improved production. Since K647 is conserved in the CGTase family, the corresponding residues in the CGTases from Bacillus circulans 251, Paenibacillus macerans, and Anaerobranca gottschalkii were changed to glutamic acid. Productions of the resulting K647E mutants were 2.0-, 1.5-, and 1.0-fold higher than those of their respective wild-types. Electrostatic protein surface analysis suggested that mutations occurring at low negative surface charge may increase CGTase production.

17.
Bone ; 130: 115121, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31678488

RESUMO

BACKGROUND: Osteoporosis and cardiovascular (CV) diseases are closely correlated. RANKL/RANK/OPG pathway and Wnt signalling pathway both implicated in the pathogenesis of osteoporosis and cardiovascular diseases. We aimed to investigate the effect of denosumab or romosozumab therapy on cardiovascular outcomes in patients with primary osteoporosis. METHODS: PubMed, Cochrane library, and EMBASE databases were systematically searched from the inception dates to June 4, 2019. Randomized clinical trials evaluating the effect of denosumab or romosozumab versus active comparators or placebo for at least 6 months in patients with primary osteoporosis or osteopenia were included. Two investigators independently extracted data for study characteristics, outcomes of interest, and risk of bias in accordance with PRISMA guidelines. RESULTS: 17 relevant studies (denosumab: n=11, 13615 participants; romosozumab: n=6, 12219 participants) were included. No associations between denosumab therapy and risk of a composite cardiovascular outcome (1.06 [95 % CI, 0.88-1.28], p=0.54), three-point major adverse cardiovascular event (3P MACE, 1.01 [95 % CI, 0.83-1.23], p=0.93), and four-point major adverse cardiovascular event (4P MACE, 0.99 [95 % CI, 0.83-1.18], p=0.89) were identified. Romosozumab therapy did not increase the risk of composite cardiovascular outcome (1.26 [95 % CI, 0.95-1.68], p=0.11), and 3P MACE (1.41 [95 % CI, 0.99-2.02], p=0.06), while increased the risk of 4P MACE (1.39 [95 % CI, 1.01-1.90], p=0.04) among elderly men and postmenopausal woman with osteoporosis over a period of 12-36 months. Denosumab or romosozumab did not increase or reduce specific cardiovascular outcomes, including CV death or death, myocardial infarction, stroke, atrial fibrillation, heart failure, aortic and intracranial aneurysm, aortic dissection, aortic valve disease and hypertension (all p>0.05). Sensitivity analysis conducted by random effects model altered the result of 4P MACE in romosozumab (1.36 [0.99-1.87], p=0.06). No other significant difference was detected in the sensitivity analyses and subgroup analyses. CONCLUSIONS: Denosumab therapy was not associated with any risk of composite and specific cardiovascular outcomes among patients with primary osteoporosis than active comparators or placebo, while romosozumab therapy might increase the risk of 4P MACE.

18.
Biomed Pharmacother ; 121: 109554, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31678753

RESUMO

γ-Oryzanol, a mixture of ferulic acid esters of plant sterols and triterpene alcohols existed in rice bran oil, can ameliorate lipid metabolism and enhance antioxidant activity. In this study, we used hydrogen peroxide (H2O2)-induced injury in human hepatic L02 cells to investigate the mechanisms involved in the hepatoprotective activity of γ-oryzanol. The injuries produced by H2O2 in L02 cells include increased levels of malondialdehyde (MDA) and intracellular reactive oxygen species (ROS), decreased activities of superoxide dismutase (SOD) and catalase (CAT), loss of mitochondrial membrane potential (MMP), increased protein expressions of caspase-9 and caspase-3, and induced apoptosis. Pretreatment with γ-oryzanol enhanced the ROS scavenging activity of endogenous antioxidant enzymes and decreased lipid peroxidation in H2O2 treated cells. Moreover, pretreatment with γ-oryzanol inhibited H2O2-induced apoptosis by restoring MMP, upregulating the expression ratio of Bcl-2/Bax, and inhibiting the activation of caspase-9 and caspase-3. These findings show that γ-oryzanol can prevent H2O2-induced apoptosis by suppressing intracellular accumulation of ROS and impeding ROS-activated mitochondrial apoptotic pathway.

19.
Adv Mater ; : e1904702, 2019 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-31709645

RESUMO

An in-depth understanding and effective suppression of nonradiative recombination pathways in perovskites are crucial to their crystallization process, in which supersaturation discrepancies at different time scales between CH3 NH3 I (MAI, methylammonium iodide) and PbI2 remain a key issue. Here, an A-site management strategy via the introduction of an A-site placeholder cation, NH4 + , to offset the deficient MA+ precipitation by occupying the cavity of Pb-I framework, is proposed. The temporarily remaining NH4 + is substituted by subsequently precipitated MA+ . The temperature-dependent crystallization process with the generation and consumption of a transient phase is sufficiently demonstrated by the dynamic changes in crystal structure characteristic peaks through in situ grazing-incidence X-ray diffraction and the surface potential difference evolution through temperature-dependent Kelvin probe force microscopy. A highly crystalline perovskite is consequently acquired, indicated by the enlarged grain size, lowered nonradiative defect density, prolonged carrier lifetime, and fluorescence lifetime imaging. Most importantly, it is identified that the A-site IMA defect is responsible for such crystal quality optimization based on theoretical calculations, transient absorption, and deep-level transient spectroscopy. Furthermore, the universality of the proposed A-site management strategy is demonstrated with other mixed-cation perovskite systems, indicating that this methodology successfully provides guidance for synthesis route design of highly crystalline perovskites.

20.
Anal Chem ; 2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31710814

RESUMO

Exploration of simple and universal methods to quantitatively measure nanoparticle (NP)-protein interaction is of great importance. In this work, pulsed streaming potential (SP) measurement has been used to evaluate the interaction between NPs and proteins within microchannels. Graphene oxide (GO) and SiO2 NPs were selected to represent two kinds of NPs. Lysozyme and common blood proteins, including albumin V, γ-globulins, and fibrinogen, were used as model proteins. The linear relationship between the initial adsorption rate (S = dEr/dt) and the concentration of proteins was observed. Combined with the Hill equation, the microscopic dissociation constant (KD) and the Hill coefficient (n) between NPs and proteins were calculated based on the relationship between S and the concentration of each protein. The concentration of free proteins which have not interacted with the NPs in the NPs-protein mixture could also be measured. The influence of pH, conductivity, and ionic strengths of the incubation buffer on the interaction between GO and lysozyme was evaluated based on the constant KD. The interaction intensity between NPs and proteins was defined as charge neutralization efficiency QC, which could be calculated from the value of S. It takes only 150 s to get the whole set of data under the optimized experiment parameters. The measurement solely depends on the surface charge, no intrinsic fluorescence is required for either the NPs or the proteins, and no labeling or immobilization process is involved as well.

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