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1.
Proc Natl Acad Sci U S A ; 121(11): e2313123121, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38437546

RESUMO

Organized flaking techniques to obtain predetermined stone tools have been traced back to the early Acheulean (also known as mode 2) in Africa and are seen as indicative of the emergence of advanced technical abilities and in-depth planning skills among early humans. Here, we report one of the earliest known examples of prepared core technology in the archaeological record, at the Cenjiawan (CJW) site in the Nihewan basin of China, dated 1.1 Mya. The operational schemes reconstructed from the CJW refit sets, together with shaping patterns observed in the retouched tools, suggest that Nihewan basin toolmakers had the technical abilities of mode 2 hominins, and developed different survival strategies to adapt to local raw materials and environments. This finding predates the previously earliest known prepared core technology from Eurasia by 0.3 My, and the earliest known mode 2 sites in East Asia by a similar amount of time, thus suggesting that hominins with advanced technologies may have migrated into high latitude East Asia as early as 1.1 Mya.


Assuntos
Hominidae , Tecnologia , Humanos , Animais , Ásia Oriental , China , África
2.
Bull Environ Contam Toxicol ; 112(4): 51, 2024 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-38556558

RESUMO

Esketamine (ESK) is the S-enantiomer of ketamine racemate (a new psychoactive substance) that can result in illusions, and alter hearing, vision, and proprioception in human and mouse. Up to now, the neurotoxicity caused by ESK at environmental level in fish is still unclear. This work studied the effects of ESK on behaviors and transcriptions of genes in dopamine and GABA pathways in zebrafish larvae at ranging from 12.4 ng L- 1 to 11141.1 ng L- 1 for 7 days post fertilization (dpf). The results showed that ESK at 12.4 ng L- 1 significantly reduced the touch response of the larvae at 48 hpf. ESK at 12.4 ng L- 1 also reduced the time and distance of larvae swimming at the outer zone during light period, which implied that ESK might potentially decrease the anxiety level of larvae. In addition, ESK increased the transcription of th, ddc, drd1a, drd3 and drd4a in dopamine pathway. Similarly, ESK raised the transcription of slc6a1b, slc6a13 and slc12a2 in GABA pathway. This study suggested that ESK could affect the heart rate and behaviors accompanying with transcriptional alterations of genes in DA and GABA pathways at early-staged zebrafish, which resulted in neurotoxicity in zebrafish larvae.


Assuntos
Dopamina , Ketamina , Humanos , Animais , Camundongos , Dopamina/metabolismo , Dopamina/farmacologia , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , Ketamina/metabolismo , Ketamina/farmacologia , Larva , Ácido gama-Aminobutírico/metabolismo , Ácido gama-Aminobutírico/farmacologia
3.
Environ Sci Technol ; 57(36): 13384-13396, 2023 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-37651267

RESUMO

Imidacloprid (IMI) and thiamethoxam (THM) are ubiquitous in aquatic ecosystems. Their negative effects on parental fish are investigated while intergenerational effects at environmentally relevant concentrations remain unclear. In this study, F0 zebrafish exposed to IMI and THM (0, 50, and 500 ng L-1) for 144 days post-fertilization (dpf) was allowed to spawn with two modes (internal mating and cross-mating), resulting in four types of F1 generations to investigate the intergenerational effects. IMI and THM affected F0 zebrafish fecundity, gonadal development, sex hormone and VTG levels, with accumulations found in F0 muscles and ovaries. In F1 generation, paternal or maternal exposure to IMI and THM also influenced sex hormones levels and elevated the heart rate and spontaneous movement rate. LncRNA-mRNA network analysis revealed that cell cycle and oocyte meiosis-related pathways in IMI groups and steroid biosynthesis related pathways in THM groups were significantly enriched in F1 offspring. Similar transcriptional alterations of dmrt1, insl3, cdc20, ccnb1, dnd1, ddx4, cox4i1l, and cox5b2 were observed in gonads of F0 and F1 generations. The findings indicated that prolonged paternal or maternal exposure to IMI and THM could severely cause intergenerational toxicity, resulting in developmental toxicity and endocrine-disrupting effects in zebrafish offspring.


Assuntos
Exposição Materna , Peixe-Zebra , Animais , Feminino , Humanos , Tiametoxam , Ecossistema
4.
Small ; 18(1): e2105246, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34741426

RESUMO

Electrocatalytic CO2 reduction reaction (CO2 RR) toward formate production can be operated under mild conditions with high energy conversion efficiency while migrating the greenhouse effect. Herein, an integrated 3D open network of interconnected bismuthene arrays (3D Bi-ene-A/CM) is fabricated via in situ electrochemically topotactic transformation from BiOCOOH nanosheet arrays supported on the copper mesh. The resulted 3D Bi-ene-A/CM consists of 2D atomically thin metallic bismuthene (Bi-ene) in the form of an integrated array superstructure with a 3D interconnected and open network, which harvests the multiple structural advantages of both metallenes and self-supported electrodes for electrocatalysis. Such distinctive superstructure affords the maximized quantity and availability of the active sites with high intrinsic activity and superior charge and mass transfer capability, endowing the catalyst with good CO2 RR performance for stable formate production with high Faradaic efficiency (≈90%) and current density (>300 mA cm-2 ). Theoretical calculation verifies the superior intermediate stabilization of the dominant Bi plane during CO2 RR. Moreover, by further coupling anodic methanol oxidation reaction, an exotic electrolytic system enables highly energy-efficient and value-added pair-electrosynthesis for concurrent formate production at both electrodes, achieving substantially improved electrochemical and economic efficiency and revealing the feasibility for practical implementation.

5.
Proc Natl Acad Sci U S A ; 116(20): 9820-9824, 2019 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-31036653

RESUMO

Middle to Late Pleistocene human evolution in East Asia has remained controversial regarding the extent of morphological continuity through archaic humans and to modern humans. Newly found ∼300,000-y-old human remains from Hualongdong (HLD), China, including a largely complete skull (HLD 6), share East Asian Middle Pleistocene (MPl) human traits of a low vault with a frontal keel (but no parietal sagittal keel or angular torus), a low and wide nasal aperture, a pronounced supraorbital torus (especially medially), a nonlevel nasal floor, and small or absent third molars. It lacks a malar incisure but has a large superior medial pterygoid tubercle. HLD 6 also exhibits a relatively flat superior face, a more vertical mandibular symphysis, a pronounced mental trigone, and simple occlusal morphology, foreshadowing modern human morphology. The HLD human fossils thus variably resemble other later MPl East Asian remains, but add to the overall variation in the sample. Their configurations, with those of other Middle and early Late Pleistocene East Asian remains, support archaic human regional continuity and provide a background to the subsequent archaic-to-modern human transition in the region.


Assuntos
Fósseis , Crânio , China , Humanos , Dente
6.
Bull Environ Contam Toxicol ; 110(1): 5, 2022 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-36507940

RESUMO

Agricultural use of neonicotinoid insecticides, neuroactive nitroguanidine compounds, has been detected everywhere in the global, posing significant hazard to nontarget organisms. This work studied the developmental neurotoxicity of zebrafish larvae exposed to imidacloprid (IMI) and thiamethoxam (THM), ranging from 0.05 µg L- 1 to 50 µg L- 1 for 35 days. Transcriptions of genes belonging to the behavior, neurodevelopment and cortisol synthesis in zebrafish larvae were monitored. The qPCR data demonstrated that with exposure time increased, the transcription of behavior related genes was down-regulated in both IMI and THM groups, such as macf1, cdh6 and syt10. Additionally, IMI and THM significantly up-regulated the transcriptions of actha, and down-regulated il1rapl1b and pi4k2a at 35 dpf. Importantly, IMI markedly enhanced the transcripiton of gfap, shha, nkx2.2a and nestin in a time dependent manner. This work provided the foundation for understanding zebrafish larvae's neurotoxicity induced by IMI and THM.


Assuntos
Inseticidas , Peixe-Zebra , Animais , Tiametoxam/toxicidade , Larva , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Inseticidas/toxicidade , Inseticidas/análise
7.
Appl Opt ; 60(22): 6682-6694, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34612912

RESUMO

Different from conventional microimaging techniques, polarization imaging can generate multiple polarization images in a single perspective by changing the polarization angle. However, how to efficiently fuse the information in these multiple polarization images by a convolutional neural network (CNN) is still a challenging problem. In this paper, we propose a hybrid 3D-2D convolutional neural network called MuellerNet, to classify biological cells with Mueller matrix images (MMIs). The MuellerNet includes a normal stream and a polarimetric stream, in which the first Mueller matrix image is taken as the input of normal stream, and the rest MMIs are stacked to form the input of a polarimetric stream. The normal stream is mainly constructed with a backbone network and, in the polarimetric stream, the attention mechanism is used to adaptively assign weights to different convolutional maps. To improve the network's discrimination, a loss function is introduced to simultaneously optimize parameters of the two streams. Two Mueller matrix image datasets are built, which include four types of breast cancer cells and three types of algal cells, respectively. Experiments are conducted on these two datasets with many well-known and recent networks. Results show that the proposed network efficiently improves the classification accuracy and helps to find discriminative features in MMIs.

8.
Ecotoxicol Environ Saf ; 227: 112917, 2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-34678628

RESUMO

Imidacloprid (IMI) and thiamethoxam (THM) are two commonly applied neonicotinoid insecticides. IMI and THM could cause negative impacts on non-target organisms like bees. However, the information about neurotoxicity of IMI and THM in fish is still scarce. Here we investigated the effects of IMI and THM on locomotor behavior, AChE activity, and transcription of genes related to synaptic transmission in zebrafish exposed to IMI and THM with concentrations of 50 ng L-1 to 50,000 ng L-1 at 14 day post fertilization (dpf), 21 dpf, 28 dpf and 35 dpf. Our results showed that IMI and THM significantly influenced the locomotor activity in larvae at 28 dpf and 35 dpf. THM elevated AChE activity at 28 dpf. The qPCR data revealed that IMI and THM affected the transcription of marker genes belonging to the synapse from 14 dpf to 35 dpf. Furthermore, IMI and THM mainly affected transcription of key genes in γ-aminobutyric acid, dopamine and serotonin pathways in larvae at 28 dpf and 35 dpf. These results demonstrated the neurotoxicity of IMI and THM in zebrafish. The findings from this study suggested that IMI and THM in the aquatic environment may pose potential risks to fish fitness and survival.


Assuntos
Inseticidas , Poluentes Químicos da Água , Animais , Abelhas , Inseticidas/análise , Inseticidas/toxicidade , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Transmissão Sináptica , Tiametoxam , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/genética
9.
Ecotoxicol Environ Saf ; 208: 111566, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396095

RESUMO

Androgens and estrogens often co-exist in aquatic environments and pose potential risks to fish populations. However, little is known about the endocrine disrupting effects of the mixture of androgens and estrogens in fish. In this study, transcriptional level of target genes related to the hypothalamic-pituitary-gonadal-liver (HPGL) axis, sex hormone level, VTG protein concentration, histology and secondary sex characteristic were assessed in the ovaries and livers of adult female western mosquitofish (Gambusia affinis) exposed to 17ß-estradiol (E2), testosterone (T), and mixtures of E2 and T for 91 days. The results showed that the transcriptional expression of cytochrome P450, family 19, subfamily A, polypeptide 1a (Cyp19a1a) was suppressed in the 200 ng/L T treatment and the 50 ng/L E2 + 200 ng/L T treatment in the ovaries. Steroidogenic acute regulatory protein (Star) and Cyp11a1 showed a similar expression pattern in the T treatment to its corresponding T + E2 mixtures. In the ovaries, the concentrations of 17ß-estradiol and testosterone were decreased in most treatments compared with the solvent control. VTG protein was induced in all steroid treatment. However, exposure to T or E2 + T mixture did not cause the abnormal cells of the ovaries and livers and an extension of the anal fins in female G. affinis. This study demonstrates that chronic exposure to E2, T and their mixtures affects the transcripts of genes in the HPGL axis, steroid hormone level and VTG protein concentration in the ovaries and livers, but fails to cause the histopathological effect of the ovaries and livers and alter the morphology of the anal fins in G. affinis.


Assuntos
Ciprinodontiformes/fisiologia , Disruptores Endócrinos/toxicidade , Estradiol/toxicidade , Androgênios/metabolismo , Animais , Ciprinodontiformes/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Disruptores Endócrinos/metabolismo , Estradiol/metabolismo , Estrogênios/metabolismo , Feminino , Hormônios Esteroides Gonadais/metabolismo , Fígado/efeitos dos fármacos , Masculino , Ovário/efeitos dos fármacos , Testosterona/metabolismo , Vitelogeninas/metabolismo
10.
Molecules ; 27(1)2021 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-35011402

RESUMO

A sensitive electrochemical immunosensor was prepared for rapid detection of ASA based on arsanilic acid (ASA) monoclonal antibody with high affinity. In the preparation of nanomaterials, polyethyleneimine (PEI) improved the stability of the solution and acted as a reducing agent to generate reduced graphene oxide (rGO) with relatively strong conductivity, thereby promoting the transfer of electrons. The dual conductivity of rGO and silver nanoparticles (AgNPs) improved the sensitivity of the sensor. The synthesis of nanomaterials were confirmed by UV-Vis spectroscopy, X-ray diffraction, transmission electron microscopy and scanning electron microscopy. In the optimal experiment conditions, the sensor could achieve the detection range of 0.50-500 ng mL-1 and the limit of detection (LOD) of 0.38 ng mL-1 (S/N = 3). Moreover, the sensor exhibited excellent specificity and acceptable stability, suggesting that the proposed sensor possessed a good potential in ASA detection. Thus, the as-prepared biosensor may be a potential way for detecting other antibiotics in meat and animal-derived foods.


Assuntos
Ácido Arsanílico/análise , Técnicas Biossensoriais , Técnicas Eletroquímicas , Grafite/química , Imunoensaio/métodos , Nanopartículas Metálicas/química , Prata/química , Limite de Detecção , Nanopartículas Metálicas/ultraestrutura , Nanocompostos/química , Polietilenoimina , Reprodutibilidade dos Testes
11.
Environ Sci Technol ; 54(10): 6009-6020, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32324390

RESUMO

Perfluoroalkyl substances (PFASs) are persistent chemicals in the environment. So far, little is known about their uptake potential in wetland plants. Here, we investigated the uptake and translocation of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) in eight common wetland plants, namely, Canna indica (Ci), Thalia dealbata (Td), Cyperus alternifolius (Ca), Phragmites australis (Pa), Arundo donax (Ad), Pontederia cordata (Pc), Cyperus papyrus (Cp), and Alisma orientale (Ao) by hydroponic experiments and visualized their tissue- and cell-level distribution with desorption electrospray ionization mass spectrometry (DESI-MS) and transmission electron microscopy equipped with energy-dispersive spectroscopy (TEM-EDS). The results showed that the PFASs accumulated in plants accounted for 1.67-16.7% of the total mass spiked into the hydroponic systems, and PFOS accumulated largely in roots (48.8-95.8%), while PFOA was stored mostly in the aboveground part (29.3-77.4%). DESI-MS and TEM-EDS analysis showed that PFASs in Ci, Td, Pa, and Ca were transported from the hydroponic solution to the root cortex via both apoplastic (e.g., across cell walls and/or intercellular spaces) and symplastic routes (e.g., across plasma membranes or via plasmodesmata) and further to the vascular bundle via symplastic route in Td and Pa and via both routes in Ci and Ca. These two chemicals were transported from roots to stems mainly through the cortex in Td and through both the cortex and vascular bundles in Ci and Ca.


Assuntos
Ácidos Alcanossulfônicos , Fluorocarbonos/análise , Caprilatos , Microscopia Eletrônica de Transmissão , Espectrometria de Massas por Ionização por Electrospray , Análise Espectral , Áreas Alagadas
12.
J Opt Soc Am A Opt Image Sci Vis ; 37(11): 1795-1805, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33175756

RESUMO

Infrared imaging has been widely used in the field of sea surface monitoring. Horizon detection is a key step before a target's detection, locating, and tracking in the sea-sky infrared scene. Reducing processing time while ensuring accuracy is the research focus of infrared horizon detection. This paper proposes a novel method of a line segment detector (LSD) algorithm with gradient direction filtering. First, the rough extraction of the sea-sky region is used to limit the size of the detected image, and then the potential horizon line segment is extracted, applying the improved LSD algorithm in the sea-sky region, which probably contains many false extraction results. Then, gradient direction filtering is designed to pick the horizon line segments in this step. Finally, the horizon line segments are stitched to obtain the whole horizon line based on random sample consensus. The results of the comparative experiments show that this novel method has high detection accuracy, and the processing time is significantly shortened; what is more, we can also conclude that this method has a good performance on the detection stability.

13.
Ecotoxicol Environ Saf ; 193: 110371, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32114246

RESUMO

Medroxyprogesterone acetate (MPA) is a widely used synthetic progestin in contraception pills and hormone replacement therapy. However, its effects on eye growth and development and function were largely unknown. In this study, the transcription of genes in the Notch signaling pathway and the visual cycle network were evaluated after chronic MPA exposure at 4.32 (L), 42.0 (M), and 424 (H) ng L-1 for 120 days in zebrafish. Meanwhile, the histology of the eyes was also examined. Transcriptional results showed that MPA at all three concentrations significantly increased the transcription of notch1a, dll4, jag1a, ctbp1 and rbpjb (key genes in the Notch signaling pathway) in the eyes of females. The up-regulation of noth1a, ctbp1 and kat2b was also observed in the eyes of males exposed to MPA at 424 ng L-1. In the visual cycle pathway, MPA increased the transcription of opn1sw1, opn1sw2, arr3a and rpe65a in the eyes of females from the M and H treatments. Histopathological analysis showed that exposure to 42.0 ng L-1 of MPA increased the thicknesses of inner nuclear layer in females and outer segment in males. Moreover, exposure to 424 ng L-1 of MPA increased the lens diameter in females. These results indicated that chronic MPA exposure affected the transcription of genes in the Notch signaling and in the visual cycle pathways, resulting in overgrowth of the eyes and interference of the eye functions. This study suggests that MPA pose a risk to fitness and survival of zebrafish in areas where MPA contamination exists.


Assuntos
Contraceptivos Hormonais/toxicidade , Olho/efeitos dos fármacos , Acetato de Medroxiprogesterona/toxicidade , Animais , Olho/crescimento & desenvolvimento , Olho/patologia , Feminino , Masculino , Receptores Notch/metabolismo , Retina , Transdução de Sinais/efeitos dos fármacos , Transcrição Gênica/efeitos dos fármacos , Peixe-Zebra/genética , Peixe-Zebra/crescimento & desenvolvimento , Peixe-Zebra/metabolismo
14.
Sensors (Basel) ; 20(11)2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-32517003

RESUMO

The normalized difference vegetation index (NDVI) is widely used in remote sensing to monitor plant growth and chlorophyll levels. Usually, a multispectral camera (MSC) or hyperspectral camera (HSC) is required to obtain the near-infrared (NIR) and red bands for calculating NDVI. However, these cameras are expensive, heavy, difficult to geo-reference, and require professional training in imaging and data processing. On the other hand, the RGBN camera (NIR sensitive RGB camera, simply modified from standard RGB cameras by removing the NIR rejection filter) have also been explored to measure NDVI, but the results did not exactly match the NDVI from the MSC or HSC solutions. This study demonstrates an improved NDVI estimation method with an RGBN camera-based imaging system (Ncam) and machine learning algorithms. The Ncam consisted of an RGBN camera, a filter, and a microcontroller with a total cost of only $70 ~ 85. This new NDVI estimation solution was compared with a high-end hyperspectral camera in an experiment with corn plants under different nitrogen and water treatments. The results showed that the Ncam with two-band-pass filter achieved high performance (R2 = 0.96, RMSE = 0.0079) at estimating NDVI with the machine learning model. Additional tests showed that besides NDVI, this low-cost Ncam was also capable of predicting corn plant nitrogen contents precisely. Thus, Ncam is a potential option for MSC and HSC in plant phenotyping projects.


Assuntos
Aprendizado de Máquina , Folhas de Planta , Zea mays , Algoritmos , Clorofila
15.
Sensors (Basel) ; 20(13)2020 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-32629882

RESUMO

High-throughput imaging technologies have been developing rapidly for agricultural plant phenotyping purposes. With most of the current crop plant image processing algorithms, the plant canopy pixels are segmented from the images, and the averaged spectrum across the whole canopy is calculated in order to predict the plant's physiological features. However, the nutrients and stress levels vary significantly across the canopy. For example, it is common to have several times of difference among Soil Plant Analysis Development (SPAD) chlorophyll meter readings of chlorophyll content at different positions on the same leaf. The current plant image processing algorithms cannot provide satisfactory plant measurement quality, as the averaged color cannot characterize the different leaf parts. Meanwhile, the nutrients and stress distribution patterns contain unique features which might provide valuable signals for phenotyping. There is great potential to develop a finer level of image processing algorithm which analyzes the nutrients and stress distributions across the leaf for improved quality of phenotyping measurements. In this paper, a new leaf image processing algorithm based on Random Forest and leaf region rescaling was developed in order to analyze the distribution patterns on the corn leaf. The normalized difference vegetation index (NDVI) was used as an example to demonstrate the improvements of the new algorithm in differentiating between different nitrogen stress levels. With the Random Forest method integrated into the algorithm, the distribution patterns along the corn leaf's mid-rib direction were successfully modeled and utilized for improved phenotyping quality. The algorithm was tested in a field corn plant phenotyping assay with different genotypes and nitrogen treatments. Compared with the traditional image processing algorithms which average the NDVI (for example) throughout the whole leaf, the new algorithm more clearly differentiates the leaves from different nitrogen treatments and genotypes. We expect that, besides NDVI, the new distribution analysis algorithm could improve the quality of other plant feature measurements in similar ways.


Assuntos
Folhas de Planta , Análise Espectral , Zea mays , Algoritmos , Clorofila/análise , Nitrogênio/análise , Folhas de Planta/química
16.
Angew Chem Int Ed Engl ; 59(35): 15014-15020, 2020 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-32421894

RESUMO

Electrochemical reduction of CO2 to valuable fuels is appealing for CO2 fixation and energy storage. However, the development of electrocatalysts with high activity and selectivity in a wide potential window is challenging. Herein, atomically thin bismuthene (Bi-ene) is pioneeringly obtained by an in situ electrochemical transformation from ultrathin bismuth-based metal-organic layers. The few-layer Bi-ene, which possesses a great mass of exposed active sites with high intrinsic activity, has a high selectivity (ca. 100 %), large partial current density, and quite good stability in a potential window exceeding 0.35 V toward formate production. It even deliver current densities that exceed 300.0 mA cm-2 without compromising selectivity in a flow-cell reactor. Using in situ ATR-IR spectra and DFT analysis, a reaction mechanism involving HCO3 - for formate generation was unveiled, which brings new fundamental understanding of CO2 reduction.

17.
Small ; 15(35): e1902218, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31293075

RESUMO

Controllable synthesis of ultrathin metal-organic framework (MOF) nanosheets and rational design of their nano/microstructures in favor of electrochemical catalysis is critical for their renewable energy applications. Herein, an in situ growth method is proposed to prepare the ultrathin NiFe MOF nanosheets with a thickness of 1.5 nm, which are vertically inlaid into a 3D ordered macroporous structure of NiFe hydroxide. The well-designed composite delivers an efficient electrocatalytic performance with a low overpotential of 270 mV at a current density of 10 mA cm-2 and stable electrolysis as long as 10 h toward the electrochemical oxygen evolution reaction, much superior to the state-of-the-art RuO2 electrocatalyst. A comprehensive analysis demonstrates that the excellent performance originates from the desirable combination of the highly exposed active centers in the ultrathin bimetallic MOF nanosheets, effective electron conduction between MOF nanosheets and ordered macroporous hydroxide, and efficient mass transfer across the hierarchically porous hybridization. This study sheds light on the exploration of powerful protocols to gain diverse high-performance MOF nanosheets and may open a perspective to achieve their efficient electrocatalytic performance.

18.
Ecotoxicol Environ Saf ; 183: 109556, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31509926

RESUMO

Dydrogesterone (DDG) is a synthetic progestin used in contraception and hormone replacement therapy. Our previous transcriptome data showed that the response to light stimulus, photoperiodism and rhythm related gene ontology (GO) terms were significantly enriched in the brain of zebrafish after chronic exposure to DDG. Here we investigated the effects of DDG on the eye of zebrafish. Zebrafish were exposed to DDG at three concentration levels (3.39, 33.1, and 329 ng L-1) for 120 days. Based on our previous transcriptome data, the transcription of genes involved in visual cycle and circadian rhythm network was examined by qPCR analysis. In the visual cycle network, exposure to all concentrations of DDG significantly decreased transcription of grk7a, aar3a and guca1d, while increased the transcription of opn1mw4 and opn1sw2 at the low concentration. Importantly, exposure to all concentrations of DDG down-regulated the transcription of rep65a that encodes a critical enzyme to catalyze the conversion from all-trans-retinal to 11-cis-retinal in the eye of male zebrafish. In the circadian rhythm network, DDG enhanced the transcription of clocka, arntl2 and nifil3-5 at all three concentrations, while it decreased the transcription of cry5, per1b, nr1d2b and si:ch211.132b12.7. In addition, DDG decreased the transcription of tefa in both males and females. Moreover, histological analysis showed the exposure to 329 ng L-1 of DDG decreased the thickness of retinal ganglion cell in the eye of male zebrafish. These results indicated that DDG exposure could affect the transcription of genes in visual cycle and circadian rhythm network in the eyes of zebrafish. This suggests that DDG has potential negative impact on the normal eye function.


Assuntos
Ritmo Circadiano/efeitos dos fármacos , Didrogesterona/toxicidade , Retina/efeitos dos fármacos , Transcriptoma/efeitos dos fármacos , Proteínas de Peixe-Zebra/genética , Peixe-Zebra/genética , Animais , Ritmo Circadiano/genética , Relação Dose-Resposta a Droga , Feminino , Masculino , Retina/metabolismo , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/metabolismo
19.
Sensors (Basel) ; 19(16)2019 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-31426414

RESUMO

Underwater acoustic communications are challenging because channels are complex, and acoustic waves when propagating in the ocean are subjected to a variety of interferences, such as noise, reflections, scattering and so on. Spread spectrum technique thus has been widely used in underwater acoustic communications for its strong anti-interference ability and good confidentiality. Underwater acoustic channels are typical coherent multipath channels, in which the inter-symbol interference seriously affects the performance of underwater acoustic communications. Time-reversal mirror technique utilizes this physical characteristic of underwater acoustic channels to restrain the inter-symbol interference by reconstructing multipath signals and reduce the influence of channel fading by spatial focusing. This paper presents an M-ary cyclic shift keying spread spectrum underwater acoustic communication scheme based on the virtual time-reversal mirror. Compared to the traditional spread spectrum techniques, this method is more robust, for it uses the M-ary cyclic shift keying spread spectrum to improve the communication rate and uses the virtual time-reversal mirror to ensure a low bit error rate. The performance of this method is verified by simulations and pool experiments.

20.
Am J Pathol ; 187(1): 25-32, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27846380

RESUMO

Vascular endothelial growth factor (VEGF)-D is capable of inducing angiogenesis and lymphangiogenesis through signaling via VEGF receptor (VEGFR)-2 and VEGFR-3, respectively. Mutations in the FIGF (c-fos-induced growth factor) gene encoding VEGF-D have not been reported previously. We describe a young male with a hemizygous mutation in the X-chromosome gene FIGF (c.352 G>A) associated with early childhood respiratory deficiency. Histologically, lungs showed ectatic pulmonary arteries and pulmonary veins. The mutation resulted in a substitution of valine to methionine at residue 118 of the VEGF-D protein. The resultant mutant protein had increased dimerization, induced elevated VEGFR-2 signaling, and caused aberrant angiogenesis in vivo. Our observations characterize a new subtype of congenital diffuse lung disease, provide a histological correlate, and support a critical role for VEGF-D in lung vascular development and homeostasis.


Assuntos
Predisposição Genética para Doença , Pneumopatias/genética , Mutação/genética , Doenças Vasculares/genética , Fator D de Crescimento do Endotélio Vascular/genética , Animais , Linhagem Celular , Galinhas , Criança , Pré-Escolar , Família , Humanos , Lactente , Recém-Nascido , Pulmão/irrigação sanguínea , Pulmão/metabolismo , Pulmão/patologia , Pneumopatias/sangue , Masculino , Neovascularização Patológica/genética , Doenças Vasculares/sangue , Fator D de Crescimento do Endotélio Vascular/sangue , Fator D de Crescimento do Endotélio Vascular/metabolismo
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