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1.
PLoS Genet ; 19(9): e1010954, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37713421

RESUMEN

As an oocyte-specific growth factor, bone morphogenetic protein 15 (BMP15) plays a critical role in controlling folliculogenesis. However, the mechanism of BMP15 action remains elusive. Using zebrafish as the model, we created a bmp15 mutant using CRISPR/Cas9 and demonstrated that bmp15 deficiency caused a significant delay in follicle activation and puberty onset followed by a complete arrest of follicle development at previtellogenic (PV) stage without yolk accumulation. The mutant females eventually underwent female-to-male sex reversal to become functional males, which was accompanied by a series of changes in secondary sexual characteristics. Interestingly, the blockade of folliculogenesis and sex reversal in bmp15 mutant could be partially rescued by the loss of inhibin (inha-/-). The follicles of double mutant (bmp15-/-;inha-/-) could progress to mid-vitellogenic (MV) stage with yolk accumulation and the fish maintained their femaleness without sex reversal. Transcriptome analysis revealed up-regulation of pathways related to TGF-ß signaling and endocytosis in the double mutant follicles. Interestingly, the expression of inhibin/activin ßAa subunit (inhbaa) increased significantly in the double mutant ovary. Further knockout of inhbaa in the triple mutant (bmp15-/-;inha-/-;inhbaa-/-) resulted in the loss of yolk granules again. The serum levels of estradiol (E2) and vitellogenin (Vtg) both decreased significantly in bmp15 single mutant females (bmp15-/-), returned to normal in the double mutant (bmp15-/-;inha-/-), but reduced again significantly in the triple mutant (bmp15-/-;inha-/-;inhbaa-/-). E2 treatment could rescue the arrested follicles in bmp15-/-, and fadrozole (a nonsteroidal aromatase inhibitor) treatment blocked yolk accumulation in bmp15-/-;inha-/- fish. The loss of inhbaa also caused a reduction of Vtg receptor-like molecules (e.g., lrp1ab and lrp2a). In summary, the present study provided comprehensive genetic evidence that Bmp15 acts together with the activin-inhibin system in the follicle to control E2 production from the follicle, Vtg biosynthesis in the liver and its uptake by the developing oocytes.


Asunto(s)
Proteína Morfogenética Ósea 15 , Inhibinas , Proteínas de Pez Cebra , Pez Cebra , Animales , Femenino , Masculino , Activinas/genética , Proteína Morfogenética Ósea 15/genética , Proteína Morfogenética Ósea 15/metabolismo , Inhibinas/genética , Inhibinas/metabolismo , Mutación , Pez Cebra/genética , Pez Cebra/metabolismo , Proteínas de Pez Cebra/genética , Proteínas de Pez Cebra/metabolismo
2.
Environ Sci Technol ; 57(43): 16190-16205, 2023 10 31.
Artículo en Inglés | MEDLINE | ID: mdl-37752410

RESUMEN

Bisphenol A (BPA) is a well-known endocrine-disrupting chemical (EDC) that has estrogenic activities. In addition to disrupting reproductive development and function via estrogenic signaling pathways, BPA can also interfere with nonreproductive functions through nonestrogenic pathways; however, the mechanisms underlying such nonestrogenic activities are not well understood. In this study, we demonstrated that BPA could disrupt otolith formation during the early development of zebrafish with long-lasting ethological effects. Using multiple mutants of estrogen receptors, we provided strong genetic evidence that the BPA-induced otolith malformation was independent of estrogen signaling. Transcriptome analysis revealed that two genes related to otolith development, otopetrin 1 (otop1) and starmaker (stm), decreased their expression significantly after BPA exposure. Knockout of both otop1 and stm genes could phenocopy the BPA-induced otolith malformation, while microinjection of their mRNAs could rescue the BPA-induced abnormalities of otolith formation. Further experiments showed that BPA inhibited the expression of otop1 and stm by activating the MEK/ERK-EZH2-H3K27me3 signaling pathway. Taken together, our study provided comprehensive genetic and molecular evidence that BPA induced the otolith malformation through nonestrogenic pathway during zebrafish early development and its activities involved epigenetic control of key genes (e.g., otop1 and stm) participating in otolith formation.


Asunto(s)
Disruptores Endocrinos , Pez Cebra , Animales , Pez Cebra/genética , Membrana Otolítica , Fenoles/toxicidad , Compuestos de Bencidrilo/toxicidad , Epigénesis Genética , Disruptores Endocrinos/toxicidad , Disruptores Endocrinos/metabolismo
3.
Arch Environ Contam Toxicol ; 80(2): 402-413, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33534037

RESUMEN

In this study, we assessed the effects of 11-day exposure of sulfadiazine (SD), sulfamethazine (SM2), norfloxacin (NOR), and enrofloxacin (ENR) on the growth, chlorophyll a (Chl. a) content, phycobiliproteins (PBPs) content, and alkaline phosphatase (ALP) activity of Chrysosporum ovalisporum, examined the removal rate of these antibiotics by C. ovalisporum, and performed acute toxicology test with Daphnia magna to determine the effect of interaction between antibiotics and cyanobacteria on aquatic animals. The results showed that the stress of SD and SM2 increased extracellular ALP activity and weakly inhibited the algal growth and the contents of Chl. a and PBPs compared with that noted in the control. ENR and NOR treatment groups exerted significant inhibition on algal growth as well as Chl. a and PBPs contents and ALP activity, although the cyanobacterium could degrade these two antibiotics more than SD and SM2. The results also revealed that the interaction between antibiotics and cyanobacteria could inhibit D. magna feeding.


Asunto(s)
Antibacterianos/metabolismo , Cianobacterias/metabolismo , Contaminantes Químicos del Agua/metabolismo , Animales , Clorofila A , Daphnia/efectos de los fármacos , Agua
4.
Nanotechnology ; 31(45): 455405, 2020 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-32348967

RESUMEN

Hematite is recognized as an excellent photocatalyst for photoelectrochemical photoanodes for water oxidation because of its favorable band gap, excellent anti-photocorrosion and structural stability in alkaline solution. However, slow charge transport and fast carrier recombination in the bulk and at the hematite photoanode/electrolyte interface, have limited its applications for water splitting. Herein, we report a highly efficient hematite/ferrhydrite (Fh) core-shell photoanode system, consisting of hematite (α-Fe2O3) semiconductor nanorods which dramatically enhance light harvesting, and ferrhydrite as the hole-storage shell. Our integrated hematite/ferrhydrite core-shell photoanode shows 2.7 times increased photo-current density under simulated sun light irradiation.

5.
J Environ Sci (China) ; 97: 141-148, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32933729

RESUMEN

Sulfonamides (SAs) are common antimicrobial drugs, which are frequently detected in surface water systems, and are difficult to degrade, posing a potential threat to the aquatic environment. However, little is known about the potential adverse effects of SAs on non-target organisms (e.g., microalgae) in the aquatic ecosystem. In this study, the effect of SAs (sulfadiazine (SD), sulfamerazine (SM1), and sulfamethazine (SM2) at 1, 5, 20, and 50 mg/L concentrations, respectively) on the freshwater microalga Dictyosphaerium sp. was investigated, with respect to changes of biomass and chlorophyll a content and induction of extracellular polymer substances (EPS), including protein and polysaccharide contents. At the same time, the residue of SAs was determined. The results showed that Dictyosphaerium sp. was tolerant to the three SAs, and the chlorophyll a content in Dictyosphaerium sp. significantly decreased on day 7, followed by a "compensation phenomena". The increase in protein and polysaccharide contents played a defensive role in Dictyosphaerium sp. against antibiotic stress, and there was a strong positive correlation between polysaccharide contents and antibiotic concentrations. Dictyosphaerium sp. exhibited 35%-45%, 30%-42%, and 26%-51% removal of SD, SM1, and SM2, respectively. This study is helpful to understand the changes of EPS in the defense process of microalgae under the action of antibiotics, and provides a new insight for the ecological removal of antibiotic pollution in natural surface water system.


Asunto(s)
Microalgas , Sulfonamidas , Clorofila A , Ecosistema , Agua Dulce
6.
Nanotechnology ; 28(27): 275401, 2017 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-28531092

RESUMEN

We report the first demonstration of a high-efficiency photoelectrochemical (PEC) water splitting reaction using a novel Si NWs/WO3 core/shell photoanode prepared by a mild and inexpensive metal-catalyzed electroless etching process followed by dip-coating, airing and annealing methods. The dense and vertically aligned Si NWs/WO3 core/shell nanostructure were characterized by scanning electron microscopy, transmission electron microscopy and x-ray diffraction. In comparison to planar n-Si, Si NWs and planar Si/WO3, the Si NWs/WO3 samples showed significantly enhanced photocurrent over the entire potential sweep range. More significantly, the Si NWs/WO3 samples have an exceptionally low photocurrent onset potential of -0.6393 V versus reversible hydrogen electrode (RHE), indicating very efficient charge separation and charge transportation processes. The as-prepared electrode also has a photocurrent density of 2.7 mA cm-2 at 0.6107 V versus RHE in 0.5 M Na2SO4 solution under simulated solar light irradiation (100 mW cm-2 from 300 W Xenon lamp coupled with an AM 1.5 G filter). An optimal solar-to-hydrogen efficiency of about 1.9% was achieved at 0.2676 V versus RHE. Electrochemical impedance spectroscopy was conducted to investigate the properties of the charge transfer process, and the results indicated that the enhanced PEC performance may due to the increased charge separation. The x-ray photoelectron spectroscopy measurements indicated the chemical composition of the Si NWs/WO3 nanostructure. Our work has provided an efficient strategy to improve the energy conversion efficiency and photocurrent of water splitting materials.

7.
Gen Comp Endocrinol ; 254: 8-13, 2017 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-28927875

RESUMEN

Prolactin (PRL) and growth hormone (GH) play important roles in regulating salt and water balance through osmoregulatory organs in vertebrates. The aim of this study was to investigate the dynamic changes of GH/PRL hormone gene expressions in the pituitary gland and their receptors in gill and kidney, as well as the plasma osmolality when the olive flounder fish Paralichthys olivaceus were acclimated in freshwater (FW) conditions. After transfer from seawater (SW) to freshwater (FW), the osmolality of FW-adaption fish reached the lowest level at 1d which rose slightly afterwards. However, the hormone gene expression of PRL increased from 2d, reaching its peak at 5d, and then decreased at 14d. At this time, the value was still significantly higher than the control, showing a similar trend to the plasma hormone PRL. In contrast, the pituitary mRNA level of GH significantly decreased at 1d and then returned to normal levels. The mRNA levels of PRL receptor (PRLR) in both gill and kidney displayed a similar trend to the pituitary PRL. We also observed the synchronous expression trend of the renal PRLR with pituitary PRL (5d) and the asynchronous expression peaks between branchial (8d) and renal PRLR (5d). Significant responses of GH and its receptor (GHR) in both gill and kidney during the FW-acclimation were not observed. Nevertheless, the gene expression of GH receptor variant (GHR-V) in both gill and kidney declined at 2d, indicating unknown osmoregulatory functions of GHR-V. Collectively, our results provided more insights of the PRL, GH and their corresponding receptors in modulating osmoregulatory responses, representing an important aspect of FW-acclimation in flounder fish.


Asunto(s)
Aclimatación/fisiología , Lenguado/fisiología , Hormona del Crecimiento/metabolismo , Prolactina/metabolismo , Receptores de Prolactina/metabolismo , Receptores de Somatotropina/metabolismo , Animales , Lenguado/sangre , Lenguado/metabolismo , Agua Dulce , Regulación de la Expresión Génica , Hormona del Crecimiento/genética , Especificidad de Órganos/genética , Concentración Osmolar , Prolactina/genética , Receptores de Prolactina/genética , Receptores de Somatotropina/genética , Agua de Mar
8.
Sci Rep ; 14(1): 24547, 2024 10 19.
Artículo en Inglés | MEDLINE | ID: mdl-39426961

RESUMEN

The interaction of microalgae on the reinforced concrete with corrosion inhibitor is not well understood. Moreover, the inhibition role of microalgae on corrosion has been reported in recent years. In this study, the corrosion inhibition behavior of Q235 carbon steel (CS) due to the presence of Chlorella sp. and benzotriazole (BTA) in alkaline artificial seawater was investigated by means of weight loss, electrochemical measurements including open circuit potential, electrochemical impedance spectroscopy, and potentiodynamic polarization curves, and surface analysis including scanning electron microscopy, energy dispersion spectrometer, and X-ray photoelectron spectroscopy. The results of reduced corrosion rates in the algae-BTA system demonstrated that Chlorella sp. could facilitate the corrosion inhibition efficiency of BTA on the CS specimens. Moreover, polarization measurement showed the algae-BTA system had a mixed-type corrosion inhibition effect. The mechanisms of inhibition were proposed to be the precipitation of iron complexes such as Fe-BTA-EPS and Fe-BTA and iron compounds on the steel surface in the presence of the microalgae and BTA-. This study highlights the application of CS corrosion control by combining biological and chemical approaches that can be used for future research and practice, rather than purely chemical approaches.


Asunto(s)
Chlorella , Agua de Mar , Acero , Triazoles , Corrosión , Acero/química , Chlorella/química , Agua de Mar/química , Triazoles/química , Triazoles/farmacología , Carbono/química , Hierro/química
9.
iScience ; 26(5): 106727, 2023 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-37216105

RESUMEN

Maintaining the completeness of cargo and achieving on-demand cargo release during long navigations in complex environments of the internal human body is crucial. Herein, we report a novel design of magnetic hydrogel soft capsule microrobots, which can be physically disintegrated to release microrobot swarms and diverse cargoes with almost no loss. CaCl2 solution and magnetic powders are utilized to produce suspension droplets, which are put into sodium alginate solution to generate magnetic hydrogel membranes for enclosing microrobot swarms and cargos. Low-density rotating magnetic fields drive the microrobots. Strong gradient magnetic fields break the mechanical structure of the hydrogel shell to implement on-demand release. Under the guidance of ultrasound imaging, the microrobot is remotely controlled in acidic or alkaline environments, similar to those in the human digestion system. The proposed capsule microrobots provide a promising solution for targeted cargo delivery in the internal human body.

10.
Environ Int ; 176: 107976, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37236126

RESUMEN

Bisphenol A (BPA) is the most simple and predominant component of the Bisphenol family. BPA is widely present in the environment and the human body as a result of its extensive usage in the plastic and epoxy resins of consumer goods like water bottles, food containers, and tableware. Since the 1930s, when BPA's estrogenic activity was first observed, and it was labeled as a "mimic hormone of E2", studies on the endocrine-disrupting effects of BPA then have been widely conducted. As a top vertebrate model for genetic and developmental studies, the zebrafish has caught tremendous attention in the past two decades. By using the zebrafish, the negative effects of BPA either through estrogenic signaling pathways or non-estrogenic signaling pathways were largely found. In this review, we tried to draw a full picture of the current state of knowledge on the estrogenic and non-estrogenic effects of BPA with their mechanisms of action through the zebrafish model of the past two decades, which may help to fully understand the endocrine-disrupting effects of BPA and its action mechanism, and give a direction for the future studies.


Asunto(s)
Disruptores Endocrinos , Pez Cebra , Animales , Humanos , Pez Cebra/metabolismo , Estrona , Fenoles/toxicidad , Fenoles/metabolismo , Compuestos de Bencidrilo/toxicidad , Compuestos de Bencidrilo/metabolismo , Disruptores Endocrinos/toxicidad , Disruptores Endocrinos/metabolismo
11.
Bioelectrochemistry ; 150: 108349, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36527798

RESUMEN

The effect of marine microalgae on the corrosion behavior of carbon steel (CS) still needs further investigation due to their dual roles. In this study, the corrosion behavior of Q235 CS specimens in f/2 medium with absence and presence of three classes of marine microalgae Synechococcus sp., Chlorella sp., and Thalassiosira sp. was investigated during a 16-day immersion period by the weight loss, electrochemical impedance spectroscopy, potentiodynamic polarization curve, and surface analysis techniques. The biomass of the three microalgae was monitored at the same time. The results showed that the values of weight loss and corrosion current density decreased, and the values of charge transfer resistance increased in the CS specimens treated with these microalgae. On day 16, the inhibition efficiency of Thalassiosira sp. group was the highest (80.78%), followed by Chlorella sp. group (70.80%), and finally Synechococcus sp. group (69.38%). But the inhibition efficiency diminished with time. Furthermore, in these microalgal treatment groups, the passivation films were found to consist of a biofilm and a corrosion product film. This study revealed that the three microalgae can effectively strengthen the barrier of the CS specimens in the f/2 medium, leading to slow down their corrosion rates.


Asunto(s)
Chlorella , Microalgas , Synechococcus , Carbono , Acero/química , Corrosión
12.
Free Radic Biol Med ; 208: 299-308, 2023 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-37625657

RESUMEN

Progressive death of dopaminergic (DA) neurons is the main cause of Parkinson's disease (PD). The discovery of drug candidates to prevent DA neuronal death is required to address the pathological aspects and alter the process of PD. Azoramide is a new small molecule compound targeting ER stress, which was originally developed for the treatment of diabetes. In this study, pre-treatment with Azoramide was found to suppress mitochondria-targeting neurotoxin MPP+-induced DA neuronal death and locomotor defects in zebrafish larvae. Further study showed that pre-treatment with Azoramide significantly attenuated MPP+-induced SH-SY5Y cell death by reducing aberrant changes in nuclear morphology, mitochondrial membrane potential, intracellular reactive oxygen species, and apoptotic biomarkers. The mechanistic study revealed that Azoramide was able to up-regulate the expression of ER chaperone BiP and thereby prevented MPP+-induced BiP decrease. Furthermore, pre-treatment with Azoramide failed to suppress MPP+-induced cytotoxicity in the presence of the BiP inhibitor HA15. Taken together, these results suggested that Azoramide is a potential neuroprotectant with pro-survival effects against MPP+-induced cell death through up-regulating BiP expression.


Asunto(s)
1-Metil-4-fenilpiridinio , Neuronas Dopaminérgicas , Chaperón BiP del Retículo Endoplásmico , Neuroblastoma , Animales , Humanos , 1-Metil-4-fenilpiridinio/toxicidad , Apoptosis , Muerte Celular , Línea Celular Tumoral , Dopamina/metabolismo , Neuronas Dopaminérgicas/metabolismo , Neuroblastoma/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Pez Cebra/metabolismo , Chaperón BiP del Retículo Endoplásmico/efectos de los fármacos , Chaperón BiP del Retículo Endoplásmico/metabolismo
13.
Mar Pollut Bull ; 182: 113978, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35914434

RESUMEN

Microplastics (MPs) in soil and sediment (SS) matrices are emerging pollution hazards to ecosystems and humans. To mitigate MP pollution, suitable extractors and associated extracting solutions are required to efficiently separate MPs from SS matrices. In this study, we introduced a four-stage microplastic extractor (ME) device and investigated the fractional separation efficiencies of three extracting solutions (ultrapure water, saturated NaCl, and corn oil-in-NaCl) plus aeration, magnetic stirring, and electric stirring for three kinds of SS matrices (loam soil, sandy sediment, and muddy sediment) with four types of virgin MP pellets (acrylonitrile butadiene styrene (ABS), polycarbonate (PC), polypropylene, and polystyrene). In addition, fragments of these four types of post-consumer MPs were also tested by the ME device. The mean recovery efficiencies of these MPs in the three SS matrices were 88.3 %-100 %. Oil-in-NaCl further improved the recovery efficiencies for the denser ABS and PC up to 40 % based on NaCl extraction.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Ecosistema , Monitoreo del Ambiente/métodos , Humanos , Plásticos , Cloruro de Sodio , Suelo , Contaminantes Químicos del Agua/análisis
14.
J Neuroendocrinol ; 32(6): e12876, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32542811

RESUMEN

Ectotherm animals, such as fish, are vulnerable when facing an extreme temperature fluctuation as a result of their inability to maintain body temperature. The caudal neurosecretory system (CNSS) is unique to fish and has been shown to maintain homeostasis in response to seasonal changes. However, its temperature sensitivity is unknown. Here, we used in vitro electrophysiological and anatomical approaches to investigate a thermosensory pathway in the CNSS. We showed that the CNSS responds directly to local hypothermal challenge via the TRP channel, and transmits this signal using the neurotransmitter, GABA, to the neurosecretory Dahlgren cells of the CNSS. These findings are the first demonstration of the thermal perception of the CNSS and add to our understanding of the physiological role of the CNSS in thermoregulation and seasonal adaptation.


Asunto(s)
Adaptación Fisiológica/fisiología , Regulación de la Temperatura Corporal/fisiología , Lenguado/fisiología , Sistemas Neurosecretores/fisiología , Animales , Electrofisiología , Homeostasis/fisiología , Estaciones del Año , Transducción de Señal/fisiología , Estrés Fisiológico/fisiología , Temperatura , Sensación Térmica/fisiología
15.
Water Res ; 185: 116220, 2020 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-32736282

RESUMEN

To improve the efficiency of antibiotic degradation, the photosynergistic performance of bismuth vanadate (BiVO4) with a microalga, Dictyosphaerium sp., was demonstrated under visible-light irradiation for the first time. Sulfamethazine (SM2) was selected as a representative sulfanilamide antibiotic, and the photocatalytic degradation mechanism of SM2 was evaluated in media via the BiVO4-algae system. The hydrothermally synthesized sample was characterized using X-ray powder diffraction, X-ray photoelectron spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy, transmission electron microscopy, Brunauer-Emmett-Teller surface area, and Fourier transform infrared spectroscopy techniques. The results demonstrated that the prepared photocatalyst corresponded to phase-pure monoclinic scheelite BiVO4. The synthesized BiVO4 showed superior photocatalytic properties under irradiation with visible light, and more than 80% of photocatalytic degradation efficiency was obtained by the BiVO4-algae system. Based on quenching experiments, the photocatalytic degradation of SM2 in the BiVO4-algae system was primarily accomplished via the generation of triplet state dissolved organic matter, and hydroxyl radicals played a small role in the degradation process. The direct oxidation of holes made no contribution to the degradation. Metabolomics data showed that a total of 91 metabolites were significantly changed between the two comparison groups (algae-SM2 group vs algae group; algae-BiVO4-SM2 group vs algae-BiVO4 group). The glycometabolism pathways were increased and the tricarboxylic acid cycle was activated when BiVO4 was present. The study provides a distinctive approach to remove antibiotics using visible light in the aqueous environment.


Asunto(s)
Microalgas , Bismuto , Catálisis , Luz , Fotólisis , Sulfametazina
16.
Sci Rep ; 10(1): 8243, 2020 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-32427937

RESUMEN

Sulfadiazine (SD), sulfamerazine (SM1), and sulfamethazine (SM2) are widely used and disorderly discharged into surface water, causing contamination of lakes and rivers. However, microalgae are regard as a potential resource to alleviate and degrade antibiotic pollution. The physiological changes of Chlorella vulgaris in the presence of three sulfonamides (SAs) with varying numbers of -CH3 groups and its SA-removal efficiency were investigated following a 7-day exposure experiment. Our results showed that the growth inhibitory effect of SD (7.9-22.6%), SM1 (7.2-45.9%), and SM2 (10.3-44%) resulted in increased proteins and decreased soluble sugars. Oxidative stress caused an increase in superoxide dismutase and glutathione reductase levels but decreased catalase level. The antioxidant responses were insufficient to cope-up with reactive oxygen species (hydrogen peroxide and superoxide anion) levels and prevent oxidative damage (malondialdehyde level). The ultrastructure and DNA of SA-treated algal cells were affected, as evident from the considerable changes in the cell wall, chloroplast, and mitochondrion, and DNA migration. C. vulgaris-mediated was able to remove up to 29% of SD, 16% of SM1, and 15% of SM2. Our results suggest that certain concentrations of specific antibiotics may induce algal growth, and algal-mediated biodegradation process can accelerate the removal of antibiotic contamination.


Asunto(s)
Antibacterianos/farmacología , Chlorella vulgaris/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Sulfonamidas/farmacología , Contaminantes del Agua/farmacología , Catalasa/genética , Catalasa/metabolismo , Chlorella vulgaris/genética , Chlorella vulgaris/metabolismo , Clorofila/metabolismo , Agua Dulce/química , Glutatión Reductasa/genética , Glutatión Reductasa/metabolismo , Malondialdehído/metabolismo , Microalgas/efectos de los fármacos , Microalgas/genética , Microalgas/metabolismo , Fotosíntesis/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Superóxido Dismutasa/genética , Superóxido Dismutasa/metabolismo
17.
ACS Appl Mater Interfaces ; 12(11): 12656-12667, 2020 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-32083456

RESUMEN

Sulfur-doped two-dimensional (2D) graphitic carbon nitride nanosheets (2D-SCN) with efficient photocatalytic activity were synthesized via (1) polycondensation of thiourea to form bulk sulfur-doped graphitic carbon nitride (SCN) and (2) followed by thermal oxidative treatment of the prepared SCN via an etching strategy to form 2D-SCN. Sulfur was doped in situ into SCN by using thiourea as the precursor, and the 2D nanosheet structure was obtained during the thermal oxidative etching process. The structural, morphological, and optical properties of the 2D-SCN sample were investigated in detail. Herein, it is shown that the thermal oxidative etching treatment and sulfur doping induced a 2D nanosheet structure (2D-SCN-3h) with a thickness of about 4.0 nm and exposure of more sulfur elements on the surface. The surface area increased from 16.6 m2/g for SCN to 226.9 m2/g. Compared to bulk SCN, a blue shift of the absorption peaks was observed for the obtained 2D-SCN-3h photocatalyst, and the absorption intensity was higher than that of the sulfur-free counterpart (2D-CN). The successful in situ doping of S element into SCN or 2D-SCN-3h samples is beneficial to the introduction of surface N defects and O species. 2D-SCN-3h indicated higher efficiency in photogenerated charge carrier separation and showed the highest reductive activity in photocatalytic splitting of water at a rate of 127.4 µmol/h under simulated solar light irradiation, which was 250 times and 3 times higher than that of SCN and 2D-CN photocatalysts, respectively. The apparent quantum efficiency was estimated to be 8.35% at 420 nm irradiation. The S-C-N bond formed by sulfur doping was beneficial to the charge-transfer process, and this led to higher photocatalytic activity according to partial density of state analysis computed by first-principles methods.

18.
Environ Pollut ; 263(Pt A): 114554, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32305800

RESUMEN

In recent years, antibiotic pollution has become worse, especially in China. In this study, the ecotoxicological effects of four frequently used antibiotics with different lipophilic degrees (log Kow) (sulfadiazine (SD), sulfamethazine (SM2), enrofloxacin (ENR), and norfloxacin (NOR)) at four concentrations of 1, 5, 20, and 50 mg L-1 were examined using batch cultures of green alga Chlorella vulgaris and cyanobacterium Chrysosporum ovalisporum for 16 days based on changes in chlorophyll fluorescence parameters (chl a, Fv/Fm, and ΦPSII) and responses of the antioxidant system. Besides, the antibiotics removal efficiencies of the two microalgae were investigated. Sulfonamides (SD and SM2) had no significant inhibitory effect on the growth of C. ovalisporum, but had an inhibitory effect on C. vulgaris, whereas fluoroquinolones (ENR and NOR) significantly inhibited C. ovalisporum. The activities of superoxide dismutase, catalase, and glutathione reductase suggested that C. vulgaris was more tolerant to these antibiotics than C. ovalisporum. The increased malondialdehyde level in both algae indicated their tolerance against antibiotics. When compared with C. ovalisporum, C. vulgaris presented better capacity to remove antibiotics. In summary, the four antibiotics exerted time- or concentration-dependent ecotoxicological effects on the microalgae examined, whereas the microalgae could remove the antibiotics based on the log Kow of the antibiotics. The findings of this study contribute to effective understanding of the ecotoxicological effects of antibiotics and their removal by microalgae.


Asunto(s)
Chlorella vulgaris , China , Cianobacterias , Fluoroquinolonas , Sulfonamidas
19.
Front Physiol ; 10: 1560, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31992988

RESUMEN

Temperature is a critical environmental factor that affect most biological and physiological processes in fish. The caudal neurosecretory system (CNSS) is unique to fish and is proved to maintain homeostasis during seasonal alterations. However, the dynamic expression and secretion pattern of its major hormones, corticotrophin-releasing hormone (CRH), urotensin I (UI), and urotensin II (UII), and their response to thermal stress has not been studied. CRH, UII and cortisol in plasma, gene expression levels of CRH, UI, and UII in the CNSS of olive flounder (Paralichthys olivaceus) were therefore characterized. UI- and UII-positive Dahlgren cells, as well as cell proliferation in the CNSS, were also quantified. The results showed that plasma cortisol and CRH were increased in both low temperature (LT) and high temperature (HT) groups. However, there was no difference in plasma UI and UII during thermal stress. In CNSS, CRH, UI, and UII mRNA levels were all significantly elevated in response to acute hypothermal stress and recovered back to the control (normal) level after 8 days of adaptation. During hyperthermal challenge, gene expression of CRH and UI only significantly increased after 8-days of transfer but no change in UII was observed. We also demonstrated an increasing percent of UI-positive Dahlgren cells in the CNSS of 8-days hyperthermal stressed fish. However, no BrdU-labeled Dahlgren cells were found among the three treatment groups. Collectively, our results demonstrate that the CNSS is subjected to dynamic responses under thermal stress and expands upon the role of the CNSS in thermoregulation. The dynamic responses of hormone levels and the gene expression of CRH, UI and UII in CNSS are all involved in the process of hyper- or hypo-thermal stress and adaptation.

20.
Glob Chall ; 3(3): 1800027, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31565365

RESUMEN

Atomically modified graphitic carbon nitride quantum dots (QDs), characterized by strongly increased reactivity and stability, are developed. These are deposited on arrays of TiO2 nanopillars used as a photoanode for the photoelectrochemical water splitting. This photoanode shows excellent stability, with 111 h of continuous work without any performance loss, which outperforms the best-reported results by a factor of 10. Remarkably, our photoanode produces hydrogen even at zero bias. The excellent performance is attributed to the enhancement of photoabsorption, as well as to the promotion of charge separation between TiO2 nanopillars and the QDs.

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