Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.208
Filtrar
1.
Artículo en Inglés | MEDLINE | ID: mdl-32379550

RESUMEN

Background: It was reported that circular RNAs (circRNAs) exerted important function in various human cancers. However, the function of circFAT1 was less reported. The purpose of this study was to reveal the functional mechanism of circFAT1 in colorectal cancer (CRC). Materials and Methods: Quantitative real-time polymerase chain reaction and western blot assay were used to detect the levels of genes. Cell proliferation ability was assessed by 3-(4, 5-dimethyl-2-thiazoyl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Flow cytometry was used to investigate cell apoptosis rate. The glucose consumption and lactate production were determined using related kits. Furthermore, the interaction between circFAT1 or ubiquitin-like PHD and RING finger domain-containing protein 1 (UHRF1) and miR-520b or miR-302c-3p was predicted by starbase3.0, and then confirmed by the dual-luciferase reporter assay. Besides, xenograft experiment was performed to analyze the effect of circFAT1 on tumor growth in vivo. Results: The levels of circFAT1 and UHRF1 were increased, as well as the levels of miR-520b and miR-302c-3p were decreased in CRC tissues and cells. CircFAT1 knockdown suppressed cell proliferation, cycle, and glycolysis as well as induced apoptosis. Interestingly, circFAT1 was a sponge of miR-520b and miR-302c-3p, and miR-520b and miR-302c-3p could target UHRF1. Both miR-520b overexpression and miR-302c-3p overexpression inhibited CRC cell growth. Furthermore, both miR-520b knockdown and miR-302c-3p depletion weakened the effect of circFAT1 knockdown on the growth of CRC cells. Besides, circFAT1 depletion repressed tumor growth in vivo. Conclusion: The authors' findings suggested that circFAT1 upregulated UHRF1 to affect CRC cell proliferation, apoptosis, and glycolysis through targeting miR-520b and miR-302c-3p, providing theoretical basis for the treatment of CRC.

2.
iScience ; 23(5): 101074, 2020 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-32403088

RESUMEN

Proteins of all living cells undergo a myriad of post-translational modifications (PTMs) that are critical to multifarious life processes. In this study, we describe the first comprehensive multiple PTM-omics atlas in parallel with quantitative proteome analyses of two representative species of African trypanosomes, Trypanosoma brucei and Trypanosoma evansi. Ten PTM types with approximately 40,000 modified sites and 150 histone marks with a fine map on each protein of the two African trypanosomes were accomplished. The two biologically different trypanosomal species displayed distinct PTM-omic features, regulation pathways, and networks. Modifications in the proteins involved in the redox system were mainly upregulated in T. brucei, whereas proteins associated with motility were predominantly modified in T. evansi. The establishment of a database of multiple PTMs in the two parasites provides us with a deep insight into the biological mechanisms that underpin life processes in trypanosomes with different life cycles.

3.
Otolaryngol Head Neck Surg ; : 194599820926144, 2020 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-32396445

RESUMEN

Objective. To describe coronavirus disease 2019 (COVID-19) patient presentations requiring otolaryngology consultation and provide recommendations for protective measures based on the experience of ear, nose, and throat (ENT) departments in 4 Chinese hospitals during the COVID-19 pandemic. Study Design. Retrospective case series. Setting. Multicenter. Subjects and Methods. Twenty hospitalized COVID-19 patients requiring ENT consultation from 3 designated COVID-19 hospitals in Wuhan, Shanghai, and Shenzhen were identified. Data on demographics, comorbidities, COVID-19 symptoms and severity, consult reason, treatment, and personal protective equipment (PPE) use were collected and analyzed. Infection control strategies implemented for ENT outpatients and emergency room visits at the Eye and ENT Hospital of Fudan University were reported. Results. Median age was 63 years, 55% were male, and 95% were in severe or critical condition. Six tracheotomies were performed. Posttracheotomy outcomes were mixed (2 deaths, 2 patients comatose, all living patients still hospitalized). Other consults included epistaxis, pharyngitis, nasal congestion, hyposmia, rhinitis, otitis externa, dizziness, and tinnitus. At all hospitals, powered air-supply filter respirators (PAPRs) were used for tracheotomy or bleeding control. PAPR or N95-equivalent masks plus full protective clothing were used for other complaints. No inpatient ENT providers were infected. After implementation of infection control strategies for outpatient clinics, emergency visits, and surgeries, no providers were infected at the Eye and ENT Hospital of Fudan University. Conclusions and Relevance. COVID-19 patients require ENT consultation for many reasons, including tracheotomy. Otolaryngologists play an indispensable role in the treatment of COVID-19 patients but, due to their work, are at high risk of exposure. Appropriate protective strategies can prevent infection of otolaryngologists.

4.
Langmuir ; 2020 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-32275446

RESUMEN

The interactions between natural colloidal organic matter and actinides in solutions are complex and not fully understood. In this work, a crew-cut polystyrene-b-poly(acry1ic acid) (PS-b-PAA) micelle is proposed as a model particle for humic acid (HA) colloid with the aim to better understand the sequestration, aggregation, and mobility of HA colloids in the presence of uranyl ions. The effects of uranyl ions on the structure of PS29k-b-PAA5k micelles in aqueous solution were mainly investigated by synchrotron small-angle X-ray scattering. A core-shell model, accounting for the thickness and contrast changes of the PAA corona induced by the adsorption of uranyl, was employed to analyze the scattering data. A combination of transmission electron microscopy, dynamic light scattering, and zetametry showed a strong affinity of uranyl ions to PAA segments in water at pH 4-5 that resulted in the shrinkage and improved contrast of the PAA corona, as well as colloidal destabilization at a high uranyl concentration.

5.
Chemosphere ; 253: 126697, 2020 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-32298915

RESUMEN

The emergence and spread of antibiotic resistance are major threats to ecosystems and human health. Transoceanic channels (e.g., ship ballast water) can transfer harmful aquatic organisms across geographically isolated waters. However, the occurrence of antibiotic resistance genes (ARGs) in ship ballast water and their relationship with microbial communities and environmental factors remain unknown. In this study, ballast water from 28 vessels sailing to Shanghai and Jiangyin (China) were collected, and the ARGs in these water samples were investigated. Considerable levels of ARGs and integrase of the class-I integrons (intI1) were detected in all ballast water samples. sul1 and tetQ were the most and least abundant ARGs in ballast water samples, respectively. The ARGs were strongly correlated with those of the 16S rRNA and intI1 genes. Ballast water exchange can reduce the absolute abundance of some kinds of ARGs while increasing the relative abundance of several ARGs (e.g., mefA, mexF, strB, sul1, and tetQ). Moreover, the bacterial hosts of ARGs were generally different in the unexchanged ballast water (UEBW) and exchanged ballast water (EBW). In particular, Leisingera and unclassified_Erythrobacteraceae were the main ARGs-associated genera in the EBW, while Pseudohongiella, Cycloclasticus, OM43_clade, norank_f_Rhodospirillaceae, and norank_f_Rhodobacteraceae were the dominant ARGs hosts in the UEBW. Overall, ship ballast water is an effective moving carrier for the global transference of ARGs, and its sufficient management is required for mitigating ARGs propagation across oceans.

6.
J Pharm Pharmacol ; 2020 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-32314371

RESUMEN

OBJECTIVES: The aim of this study was to evaluate the effect of tectorigenin on treating allergic asthma model of guinea pigs and investigate the underlying mechanisms. METHODS: Allergic asthma model of guinea pigs was established by sensitizing with ovalbumin (OVA). Then OVA-sensitized guinea pigs were injected with 10 mg/kg tectorigenin, 25 mg/kg tectorigenin or dexamethasone to investigate the effect of tectorigenin. KEY FINDINGS: High dose of tectorigenin effectively decreased the number of coughs, the number of inflammatory cells and the levels of pro-inflammatory factors. Moreover, tectorigenin could inhibit pulmonary fibrosis in guinea pigs sensitized with OVA. In addition, the functions of tectorigenin were realized through downregulating profibrotic factors of transforming growth factor (TGF)-ß1, phosphorylated (p)-Smad2/3 and Smad4, upregulating fibrosis-inhibitor of Smad7 and decreasing pro-inflammatory factors of vascular endothelial growth factor A (VEGFA), tumour necrosis factor-α (TNF-α), Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), p-inhibitor of nuclear factor-kappa B (NF-κB) kinase ß (p-IKKß) and NF-κB. CONCLUSIONS: Tectorigenin could inhibit pulmonary fibrosis and airway inflammation through TGF-ß1/Smad signalling pathway and TLR4/NF-κB signalling pathway. Therefore, tectorigenin might be a promising medicine to treat allergic asthma.

7.
Helicobacter ; : e12692, 2020 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-32314468

RESUMEN

BACKGROUND AND AIMS: The efficacy of PPI-amoxicillin dual therapy (high-dose dual therapy) in the eradication of Helicobacter pylori is controversial. We aimed to investigate whether PPI-amoxicillin dual therapy is effective. METHODS: We searched several publication databases for randomized controlled trials (RCTs) that compared PPI-amoxicillin dual therapy with controls up to March 2019. Meta-analyses of eradication rates were performed using random-effects models. RESULTS: Data from twelve RCTs including 2249 patients suggested that PPI-amoxicillin dual therapy and the current mainstream guidelines-recommended therapies achieved similar efficacy (83.2% vs 85.3%, risk ratio [RR]: 1.00, 95% CI 0.97-1.03, intention-to-treat analysis), (87.5% vs 90.1%, RR: 0.98, 95% CI 0.95-1.02, per-protocol analysis), and compliance (94.3% vs 93.5%, RR: 1.11, 95% CI 0.78-1.59), but side effects were less likely in the dual therapy (12.9% vs 28.0%, RR: 0.53, 95% CI 0.37-0.76). Further subgroup analyses showed that the seven RCTs (1302 patients) that reported antimicrobial susceptibility test results also showed that PPI-amoxicillin dual therapy and the current guidelines-recommended therapies achieved similar efficacy, and PPI-amoxicillin dual therapy was as effective for rescue therapy (RR: 0.97, 95% CI 0.89-1.05) as for first-line treatment (RR: 0.97, 95% CI 0.93-1.02). CONCLUSIONS: Compared with the current mainstream guidelines-recommended therapies, PPI-amoxicillin dual therapy has the same efficacy and compliance, and generally PPI-amoxicillin dual therapy causes fewer side effects.

8.
Mol Biol Evol ; 2020 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-32243529

RESUMEN

Fisher's fundamental theorem of natural selection predicts no additive variance of fitness in a natural population. Consistently, studies in a variety of wild populations show virtually no narrow-sense heritability (h2) for traits important to fitness. However, counterexamples are occasionally reported, calling for a deeper understanding on the evolution of additive variance. In this study we propose adaptive divergence followed by population admixture as a source of the additive genetic variance of evolutionarily important traits. We experimentally tested the hypothesis by examining a panel of ∼1,000 yeast segregants produced by a hybrid of two yeast strains that experienced adaptive divergence. We measured over 400 yeast cell morphological traits and found a strong positive correlation between h2 and evolutionary importance. Because adaptive divergence followed by population admixture could happen constantly, particularly in species with wide geographic distribution and strong migratory capacity (e.g., humans), the finding reconciles the observation of abundant additive variances in evolutionarily important traits with Fisher's fundamental theorem of natural selection. Importantly, the revealed role of positive selection in promoting rather than depleting additive variance suggests a simple explanation for why additive genetic variance can be dominant in a population despite the ubiquitous between-gene epistasis observed in functional assays.

9.
Nat Commun ; 11(1): 1675, 2020 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-32245969

RESUMEN

The laurel family within the Magnoliids has attracted attentions owing to its scents, variable inflorescences, and controversial phylogenetic position. Here, we present a chromosome-level assembly of the Litsea cubeba genome, together with low-coverage genomic and transcriptomic data for many other Lauraceae. Phylogenomic analyses show phylogenetic discordance at the position of Magnoliids, suggesting incomplete lineage sorting during the divergence of monocots, eudicots, and Magnoliids. An ancient whole-genome duplication (WGD) event occurred just before the divergence of Laurales and Magnoliales; subsequently, independent WGDs occurred almost simultaneously in the three Lauralean lineages. The phylogenetic relationships within Lauraceae correspond to the divergence of inflorescences, as evidenced by the phylogeny of FUWA, a conserved gene involved in determining panicle architecture in Lauraceae. Monoterpene synthases responsible for production of specific volatile compounds in Lauraceae are functionally verified. Our work sheds light on the evolution of the Lauraceae, the genetic basis for floral evolution and specific scents.

10.
J Am Heart Assoc ; 9(7): e014175, 2020 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-32233751

RESUMEN

Background Previous studies reported that early-life exposure to undernutrition is associated with the risk of diabetes mellitus and metabolic syndrome in adulthood, but the association with risk of cardiovascular disease (CVD) later in life remains unclear. The current study aimed to investigate whether exposure to Chinese famine in early life is associated with risk of CVD. Methods and Results We used data from REACTION (Risk Evaluation of Cancers in Chinese Diabetic Individuals: A Longitudinal Study), which recruited a total of 259 657 community-dwelling adults aged 40 years or older from 25 centers across mainland China between 2011 and 2012. Compared with the nonexposed participants, those who had been exposed to famine in early life had a significantly increased risk of total CVD, myocardial infarction, stroke, and coronary heart disease. In the multivariable-adjusted logistic regression model, the odds ratios (95% CI) for total CVD, myocardial infarction, stroke, and coronary heart disease in fetal famine exposure were 1.35 (1.20-1.52), 1.59 (1.08-2.35), 1.40 (1.11-1.78), and 1.44 (1.26-1.65), respectively; those odds ratios in childhood famine exposure were 1.59 (1.40-1.81), 2.20 (1.52-3.20), 1.82 (1.45-2.28), and 1.80 (1.56-2.09), respectively; and those in adolescent famine exposure were 1.52 (1.27-1.81), 2.07 (1.28-3.35), 1.92 (1.42-2.58), and 1.83 (1.50-2.24), respectively. The main finding of our study is that, compared with those who lived in the less severely affected famine area, individuals in the severely affected famine area had significantly increased risk of total CVD in all 3 exposed groups. Conclusions Early-life exposure to undernutrition is associated with significantly increased risk of CVD in later life, especially among those who were in the severely affected famine area.

11.
BMC Med Genomics ; 13(Suppl 5): 43, 2020 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-32241263

RESUMEN

BACKGROUND: Non-synonymous mutations altering tumor suppressor genes and oncogenes are widely studied. However, synonymous mutations, which do not alter the protein sequence, are rarely investigated in melanoma genome studies. METHODS: We explored the role of somatic synonymous mutations in melanoma samples from TCGA (The Cancer Genome Atlas). The pathogenic synonymous mutation and neutral synonymous mutation data were used to assess the significance of pathogenic synonymous mutations in melanoma likely to affect genetic regulatory elements using Fisher's exact test. Poisson distribution probabilities of each gene were used to mine the genes with multiple potential functional synonymous mutations affecting regulatory elements. RESULTS: Concentrating on five types of genetic regulatory functions, we found that the mutational patterns of pathogenic synonymous mutations are mostly involved in exonic splicing regulators in near-splicing sites or inside DNase I hypersensitivity sites or non-optimal codon. Moreover, the sites of miRNA binding alteration exhibit a significantly lower rate of evolution than other sites. Finally, 12 genes were hit by recurrent potentially functional synonymous mutations, which showed statistical significance in the pathogenic mutations. Among them, nine genes (DNAH5, ADCY8, GRIN2A, KSR2, TECTA, RIMS2, XKR6, MYH1, SCN10A) have been reported to be mutated in melanoma, and other three genes (SLC9A2, CASR, SLC8A3) have a great potential to impact melanoma. CONCLUSION: These findings confirm the functional consequences of somatic synonymous mutations in melanoma, emphasizing the significance of research in future studies.

12.
J Agric Food Chem ; 2020 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-32348140

RESUMEN

In this study, the effects of white light-emitting diode (LED) and UV-C radiation (with the same intensity) on stilbene biosynthesis and phytochemicals accumulation of peanut sprouts were investigated. Results showed that white light radiation promoted the growth of peanut sprouts while UV-C radiation had the opposite effect. Contents of total phenolics, total flavonoids, and phytochemicals significantly increased in peanut sprouts treated by white light or UV-C radiation. Besides, light radiation significantly induced stilbene accumulation by upregulating the expression of genes and enzymes in stilbene biosynthesis-related pathway, and UV-C was more effective to promote stilbene accumulation. Compared with piceid and piceatannol, resveratrol showed the highest accumulation in peanut sprouts treated by light radiation. In summary, white light or UV-C radiation could be used as a method to promote stilbene biosynthesis and phytochemicals accumulation in peanut sprouts and UV-C was more effective.

13.
Medicine (Baltimore) ; 99(17): e19867, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32332651

RESUMEN

BACKGROUND: This systematic review aims to evaluate the effectiveness of electroacupuncture in treatment of lumbar disc herniation (LDH). METHODS: Electronic databases of all electroacupuncture for LDH will be searched at PubMed, Cochrane Library, Springer, EMBASE, China National Knowledge Infrastructure (CNKI), Wan-Fang, and Chinese Biological Medical disc, (CBM) from inception to February 29, 2020, with language restricted in Chinese and English. The primary outcome is Japanese Orthopedic Association Scores, a quantification scale for a comprehensive assessment according to patients' subjects feeling and objective function. Secondary outcomes included visual analogue scale (VAS), Oswestry dysfunction index (ODI), Pittsburgh sleep quality index (PSQI), Self-rating anxiety scale (SAS), self-depression rating scale (SDS), follow-up relapse rate. The systematic review and searches for randomized controlled trials of this therapy for LDH. The Cochrane RevMan V5.3 bias assessment tool is implemented to assess bias risk, data integration risk, meta-analysis risk, and subgroup analysis risk (if conditions are met). Mean difference (MD), standard mean deviation (SMD) and binary data will be used to represent continuous results. RESULTS: This study will provide a comprehensive review and evaluation of the available evidence for the treatment of LDH with this therapy. CONCLUSION: This study will provide new evidence to evaluate the effectiveness and side effects of electroacupuncture for LDH. Due to the data is not personalized, no formal ethical approval is required.


Asunto(s)
Electroacupuntura/normas , Degeneración del Disco Intervertebral/terapia , Desplazamiento del Disco Intervertebral/terapia , Protocolos Clínicos , Electroacupuntura/métodos , Humanos , Degeneración del Disco Intervertebral/fisiopatología , Desplazamiento del Disco Intervertebral/fisiopatología , Metaanálisis como Asunto , Literatura de Revisión como Asunto , Resultado del Tratamiento
14.
Medicine (Baltimore) ; 99(17): e19901, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32332667

RESUMEN

BACKGROUND: The aim of this systematic review with meta-analysis is to determine the efficacy and security of acupuncture in treatment of ocular myasthenia gravis and find out whether or not the quick short-term efficacy of acupuncture exists. METHODS: The following electronic databases will be searched by 2 independent reviewers: PubMed, Cochrane Library, EMBASE, Springer, China National Knowledge Infrastructure, Wanfang, and Chinese Biomedical Literature Database. All randomized controlled trials on acupuncture for ocular myasthenia gravis published in electronic databases from inception to March 1, 2020, with language restricted in Chinese and English will be included in the study.Methodologic quality is assessed by 2 blinded reviewers independently screen and score the articles using the PEDro scale and the Cochrane Collaboration risk of bias tool. A meta-analysis was performed when there is sufficient clinical homogeneity in at least 2 studies. The Grading of Recommendations Assessment, Development and Evaluation approach is used to rate the body of evidence in each meta-analysis. When the quantitive evaluation is not available, a qualitative description of the results of single study is provided. RESULTS: An evidence of variety of acupuncture treatment methods for treating ocular myasthenia gravis will be illustrated using subjective reports and objective measures of performance. The primary outcomes consisted of effective rate, MGFA PIS, QMG, and MG-composite. Secondary outcomes involve clinical absolute and relative score, titers of AchR antibodies, and the side effects. The treatment frequency and courses will be measured. CONCLUSION: This protocol will present the evidence of whether acupuncture is an effective and safe intervention for ocular myasthenia gravis. TRIAL REGISTRATION NUMBER: CRD42019141325.


Asunto(s)
Terapia por Acupuntura/normas , Protocolos Clínicos , Miastenia Gravis/terapia , Terapia por Acupuntura/métodos , Humanos , Metaanálisis como Asunto , Miastenia Gravis/fisiopatología , Proyectos de Investigación , Literatura de Revisión como Asunto
15.
Aging (Albany NY) ; 12(7): 6109-6119, 2020 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-32259797

RESUMEN

Oxygen and glucose deprivation (OGD)-reoxygenation (OGDR) induces oxidative injury to endometrial cells in vitro. We tested the potential effect of ginsenoside Rh3 (GRh3) in the process. Our results show that GRh3 activated Nrf2 signaling in T-HESC cells and primary murine endometrial cells. GRh3 induced Nrf2 Ser-40 phosphorylation and Keap1-Nrf2 disassociation, causing Nrf2 protein stabilization and nuclear translocation, which led to transcription and expression of antioxidant response element-dependent genes (HO1, NQO1 and GCLC). In T-HESC cells and primary murine endometrial cells, GRh3 potently attenuated OGDR-induced reactive oxygen species production, lipid peroxidation and mitochondrial depolarization, as well as cell viability reduction and necrosis. Activation of Nrf2 is required for GRh3-induced anti-OGDR actions in endometrial cells. Nrf2 inhibition, by Nrf2 shRNA, knockout (through CRISPR-Cas9-editing) or S40T mutation, abolished GRh3-induced endometrial cell protection against OGDR. Additionally, forced activation of Nrf2, by Keap1 knockout, mimicked and nullified GRh3-induced anti-OGDR actions in T-HESC cells. Together, we conclude that GRh3 protects endometrial cells from OGDR via activation of Nrf2 signaling.

16.
J Agric Food Chem ; 68(17): 4981-4990, 2020 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-32271576

RESUMEN

In this study, the antioxidant capacity and oxidative stability of zeaxanthin with different concentrations in soybean oil were evaluated. The oxidative or isomerization products of zeaxanthin were monitored during oxidation for 12 h at 110 °C. It was found that the ability to scavenge the free radicals (DPPH, FRAP, and ABTS) was dependent upon the concentration of zeaxanthin. However, antioxidation of zeaxanthin was observed when the concentration was less than 50 µg/g. When the concentration exceeded 50 µg/g, zeaxanthin acted as a pro-oxidant. There were three kinds of non-volatile products of zeaxanthin that were detected: (a) Z-violaxanthin, (b) 9-Z-zeaxanthin, and (c) 13-Z-zeaxanthin, and it was found that the content of 13-Z-zeaxanthin formed by isomerization was the highest. In addition, the linear ketone (6-methyl-3,5-heptadien-2-one) and cyclic volatile products (3-hydroxy-ß-cyclocitral, 3-hydroxy-5,6-epoxy-7,8-dihydro-ß-ionone, and 3-hydroxy-ß-ionone) formed by in situ oxidative cleavage were identified.

17.
Chem Commun (Camb) ; 56(39): 5243-5246, 2020 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-32270148

RESUMEN

We develop a label-free fluorescence method for ultrasensitive detection of apoptosis-associated caspase activity based on branched rolling circle amplification. This work demonstrates for the first time the use of a nucleic acid amplification strategy for the amplified detection of caspase activity, which allows for highly sensitive detection of endogenous caspase even at the single-cell level. This method can be further applied for kinetic analysis and inhibitor screening.

18.
Ecotoxicol Environ Saf ; 196: 110552, 2020 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-32259759

RESUMEN

Nowadays, numerous studies have focused on the newly developed technologies for the thorough removal of tetracyclines (TCs). However, it is often ignored that the parent TCs have limited stability in aquatic environments. Thus, this study selected green alga Chlamydomonas reinhardtii with high chlorophyll content to rapidly degrade chlortetracycline (CTC) into products with low toxicity. As the results shown, the half-life times of CTC (1 × 10-6 mol/L) decreased from 10.35 h to 2.55 h by the presence of C. reinhardtii at 24±1 °C with 12/12 h dark/light cycle. The main transformation products were iso-chlortetracycline (ICTC), 4-epi-iso-chlortetracycline (EICTC), and other degradation products with lower molecular weight. The toxicity evaluation shows that the negative effects of CTC on growth rate and soluble protein content of green algae were significantly alleviated after the enhanced degradation treatment, while the generation of reactive oxygen species (ROS) and antioxidant response in algal cells returned to normal levels. The chlorophyll of algae played an important role of photosensitizer, which catalyzed the photo-induced electron/energy transfer of CTC degradation. The ROS generation of algae also was also inseparable from the enhanced degradation of CTC, especially when the chlorophyll was damaged at the high CTC concentration. Based on these results, we can better select suitable algal species to further strengthen the degradation of antibiotics and effectively reduce the environmental risk of CTC in aqueous system.

19.
Disaster Med Public Health Prep ; : 1-7, 2020 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-32284089

RESUMEN

OBJECTIVES: Disaster literacy, which is a concept involved in moral quality, knowledge, and ability, impacts the disaster response. This study aimed to evaluate disaster education needs and to determine the affecting factors of disaster literacy among college students. METHODS: A cross-sectional study was conducted through questionnaires. A total of 7200 college students from 10 colleges and universities in 5 provinces and cities in China were investigated. RESULTS: Disaster education needs were urgently. For the participants, 79.43% stated that their families were not prepared for disaster prevention items, 96.36% suggested a campus emergency rescue team, and 88.64% obtained disaster knowledge through TV or Internet, and only 12.89% had offered relevant courses in their disciplines. The total scores of college students' disaster literacy were 87.85 ± 19.86, which was at a low level. Multiple linear regression analysis showed that age, major, grade, place of residence, parental education, mother's occupation, disaster experience, disaster training experience, and family disaster preparedness significantly affected college students' disaster literacy, especially grade, family disaster preparedness, and place of residence. CONCLUSIONS: College students' disaster literacy education is urgently needed. Families, communities, colleges and the government should attach importance to disaster literacy education for college students.

20.
Artículo en Inglés | MEDLINE | ID: mdl-32340437

RESUMEN

Tetragonal tungsten bronze (TTB) materials are one of the most promising classes of materials for ferroelectric and nonlinear optical devices, owing to their very unique noncentrosymmetric crystal structure. In this work, a new TTB phase of LiNb6Ba5Ti4O30 (LNBTO) has been discovered and studied. A small amount of a secondary phase, LiTiO2 (LTO), has been incorporated as nanopillars that are vertically embedded in the LNBTO matrix. The new multifunctional nanocomposite thin film presents exotic highly anisotropic microstructure and properties, e.g., strong ferroelectricity, high optical transparency, anisotropic dielectric function, and strong optical nonlinearity evidenced by the second harmonic generation results. An optical waveguide structure based on the stacks of α-Si on SiO2/LNBTO-LTO has been fabricated, exhibiting low optical dispersion with an optimized evanescent field staying in the LNBTO-LTO active layer. This work highlights the combination of new TTB material designs and vertically aligned nanocomposite structures for further enhanced anisotropic and nonlinear properties.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA