ABSTRACT
Prospective photocatalytic ammonia synthesis process has received more attentions but quite challenging with the low visible light utilization and weak N2 molecule absorption ability around the photocatalysts. Herein, interface reconstruction of MXene-Ti3C2/CeO2 composites with high-concentration active sites through the carbon-doped process are presented firstly, and obvious transition zones with the three-phase reaction interface are formed in the as-prepared catalysts. The optimal co-doped sample demonstrates an excellent photo response in the visible light region, the strongest chemisorption activity and the most active sites. Moreover, much more in-situ extra oxygen defects are also produced under light irradiation. It is expected that the double decorated catalyst shows a remarked ammonia production rate of above 0.76 mmol gcal-1·h-1 under visible-light illumination and a higher apparent quantum efficiency of 1.08 % at 420 nm, which is one of the most completive properties for the photocatalytic N2 fixation at present.
ABSTRACT
The photocatalytic performance of ceria-based materials can be tuned by adjusting the surface structures with decorating the transition-metal, which are considered as the important active sites. Herein, cuprous oxide-metallic copper composite-doped ceria nanorods were assembled through a simple hydrothermal reduction method. The photocatalytic ammonia synthesis rates exhibit an inverted "V-shaped" trend with increasing Cu0/CuxO mole ratio. The best ammonia production rate, approximately 900 or 521 µmol·gcal-1·h-1 under full-spectra or visible light, can be achieved when the Cu0/CuxO ratio is approximately 0.16, and this value is 8 times greater than that of the original sample. The absorption edge of the as-prepared samples shifted towards visible wavelengths, and they also had appropriate ammonia synthesis levels. This research provides a strategy for designing noble metal-free photocatalysts through introducing the metal/metallic oxide compositesto the catalysts.
ABSTRACT
We systematically studied several of the most traditional hollow-core anti-resonant fiber (HC-ARF) structures, with the aim of achieving low confinement loss, single-mode performance, and high insensitivity to bending in the 2 µm band. Moreover, the propagation loss of fundamental mode (FM), higher-order mode (HOMs), and the higher-order mode extinction ratio (HOMER) under different geometric parameters were studied. Analysis showed that the confinement loss of the six-tube nodeless hollow-core anti-resonant fiber at 2 µm was 0.042 dB/km, and its higher-order mode extinction ratio was higher than 9000. At the same time, a confinement loss of 0.040 dB/km at 2 µm was achieved in the five-tube nodeless hollow-core anti-resonant fiber, and its higher-order mode extinction ratio was higher than 2700.
ABSTRACT
Environmentally friendly photocatalytic N2 fixation process has attracted considerable attention. Developing efficient photocatalysts with high electron-hole separation rates and gas adsorption capacities remains quite challenging. Herein, a facile fabrication strategy of Cu-Cu2O and multicomponent hydroxide S-scheme heterojunctions with carbon dot charge mediators is reported. The rational heterostructurebrings excellent N2 absorption ability and high photoinduced electron/hole separation efficiency, and the ammonia produced yield reach above 210 µmol·gcal-1·h-1 during the nitrogen photofixation process. More superoxide and hydroxyl radicals are generated simultaneously in the as-prepared samples under light illumination. This work offers a reasonable construction method to further develop suitable photocatalysts for ammonia synthesis.
ABSTRACT
The green synthesis process of photocatalytic ammonia production has received more and more attentions. Herein, a Z-scheme heterojunction with all-solid-state structures is constructed, in which carbon dots can act as electron transferring mediators. The photocatalytic measurement shows that the modified photocatalysts exhibit much higher activities, in which the ammonia production rates can reach above 232 µmol·gcal-1·h-1 under the light irradiation. The improved catalytic properties can be credited to the significantly increased number of photoinduced oxygen vacancies, the excellent visible-light adsorption abilities and photogenerated electron-hole separation efficiencies for the carbon dots bridged heterostructures. More hydroxyl and superoxide radicals can be simultaneously produced in the composites. This work provides reasonable guidance for applications in photocatalytic ammonia synthesis and a promising construction strategy of efficient Z-scheme photocatalysts.
ABSTRACT
In this paper, we report for the first time on an all-multimode fiber spatiotemporal mode-locked figure-eight laser operating at 1.0 µm. This laser utilizes a multimode gain fiber and a nonlinear amplifying loop mirror mechanism. It can generate mode-locked noise-like pulses at different central wavelengths. Additionally, we observed the presence of a multi-soliton state within the cavity by reducing intracavity gain. This study contributes to a broader investigation of various pulse phenomena in spatiotemporal mode-locked lasers and provides valuable insights into further exploring the evolution of spatiotemporal dynamics in such systems.
ABSTRACT
OBJECTIVE: To determine the influences of etoposide combined with cisplatin on prognosis of patients with castration-resistant prostate cancer (CRPC) who failed castration treatment. METHODS: A total of 100 patients with metastatic CRPC who failed castration treatment in our hospital from January 2015 to January 2017 were retrospectively analyzed. The patients were divided into a control group (n=59) treated with docetaxel combined with prednisone and an experimental group (n=41) treated with etoposide combined with cisplatin (EP). The change in prostate-specific antigen (PSA) level was adopted as the evaluation criterion for efficacy, by which the total clinical effective rate of patients was calculated. The neurologic rating scale (NRS) was adopted to evaluate the pain of patients, and the incidence of adverse reactions was compared between the two groups. Cox regression was carried out to analyze independent prognostic factors impacting 3-year survival. RESULTS: The experimental group showed a significantly better clinical improvement than the control group (P<0.05). According to further analysis, the experimental group had a significantly higher clinical efficacy rate than the control group (P<0.05). Life quality scores of the experimental group were higher than those of the control group (all P<0.05). The two groups were not greatly different in bone pain, or incidence of adverse reactions (both P>0.05). The median survival time of the control group was 15.9 months, while that of the experimental group was 18 months, and the control group experienced a greatly shorter median survival time than the experimental group (P=0.040). According to Cox regression analysis, Gleason score, clinical stage, and metastasis were independent factors impacting the patients' 3-year prognosis (all P<0.05). CONCLUSION: EP regimen can strongly improve the 3-year survival rate of patients, without increasing adverse reactions.
ABSTRACT
Aberrant expression of long non-coding RNAs (lncRNAs) that results in sustained activation of cell growth promoting pathways is an important mechanism in driving prostate cancer progression. In the present study, we explored differentially expressed lncRNAs in two microarray datasets of prostate benign and malignant tissues. We found that MAGI2-AS3 was one of the most downregulated lncRNAs in prostate tumors, which was further confirmed in our collected clinical samples. The function assays showed that MAGI2-AS3 overexpression decreased cell viability and led to obvious cell apoptosis in PC-3 and DU145 prostate cancer cells. Elevation of MAGI2-AS3 decreased the activity of STAT3 in PC-3 and DU145. In addition, microRNA-424-5p (miR-424-5p), a positive regulator of STAT3 pathway, was predicted as a target of MAGI2-AS3, furthermore, the interaction between MAGI2-AS3 and miR-424-5p was confirmed via reverse-transcript polymerase chain reaction (RT-qPCR), dual luciferase reporter assay and RNA immunoprecipitation (RIP). MAGI2-AS3 upregulated miR-424-5p and downregulated COP1 in PC-3 and DU145. More importantly, IL6-induced activation of STAT3 pathway could attenuate the biological effect of MAGI2-AS3 in PC-3 and DU145. In clinical samples, MAGI2-AS3 levels were negatively correlated with miR-424-5p expression, while positively correlated with COP1 mRNA expression. Altogether, the current study revealed MAGI2-AS3 as a novel negative regulator of prostate cancer development.
ABSTRACT
BACKGROUND: Circular RNAs (circRNAs) are implicated in the development of oral squamous cell carcinoma (OSCC). The aim of current research is to elucidate the role and mechanism of circ_0011946 in the functional behaviors of OSCC cells. METHODS: Circ_0011946, microRNA (miR)-216a-5p, B cell lymphoma-2-like 2 protein (BCL2L2) abundances were exposed by quantitative reverse transcription polymerase chain reaction (qRT-PCR) or western blot. Cell proliferation, migration, invasion and apoptosis were detected by MTT, colony formation assay, transwell, wound-healing and flow cytometry assays, respectively. Target correlation was tested by dual-luciferase reporter and RNA pull-down assays. An in vivo xenograft experiment was employed to investigate the function of circ_0011946 on tumor growth in vivo. RESULTS: Circ_0011946 and BCL2L2 levels were increased, while miR-216a-5p level was decreased in OSCC tissues and cells. Circ_0011946 knockdown impeded proliferation, migration, and invasion, but promoted apoptosis in OSCC cells. Circ_0011946 functioned as a sponge for miR-216a-5p, and BCL2L2 was targeted by miR-216a-5p. Besides, miR-216a-5p or BCL2L2 knockdown partly attenuated the inhibitory influences of circ_0011946 silence or miR-216a-5p overexpression on OSCC cell progression. Furthermore, circ_0011946 post-transcriptionally regulated BCL2L2 through sponging miR-216a-5p. Moreover, circ_0011946 knockdown constrained OSCC tumor growth in vivo. CONCLUSION: Circ_0011946 silence repressed OSCC cell proliferation, migration, and invasion, but promoted apoptosis through the regulation of the miR-216a-5p/BCL2L2 axis.
Subject(s)
Apoptosis Regulatory Proteins/metabolism , Carcinoma, Squamous Cell/metabolism , MicroRNAs/metabolism , Mouth Neoplasms/metabolism , RNA, Circular/metabolism , Animals , Apoptosis/genetics , Apoptosis Regulatory Proteins/genetics , Carcinoma, Squamous Cell/pathology , Cell Line, Tumor , Cell Movement/genetics , Cell Proliferation/genetics , Female , Gene Silencing , Humans , Male , Mice , Mice, Inbred BALB C , Mice, Nude , MicroRNAs/genetics , Middle Aged , Mouth Neoplasms/pathology , Neoplasm Invasiveness/genetics , Neoplasm Transplantation , RNA InterferenceABSTRACT
A feasible tuning method for oxygen vacancies was realized by annealing under 3â atm H2 with (001)-exposed TiO2 nanosheets. The colored TiO2 sample exhibits an excellent N2 photo-fixation rate owing to the abundant oxygen vacancies (OVs) thus demonstrating that annealing with high pressure H2 is exceedingly efficient for tuning surface OVs.
ABSTRACT
Hierarchical Bi2WO6 nanostructures self-assembled with planar arranged nanosheets and dispersed Bi2WO6 nanosheets were synthesized with different dosages of EG via a simple hydrothermal route. The Bi2WO6 photocatalysts were analyzed by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (DRS) and X-ray photoelectron spectroscopy (XPS). A control experiment was conducted to test the effect of EG dosage on the growth mechanism and behavior of the highly (010) exposed hierarchical lamellar nanostructures and dispersed nanosheets. The photocatalytic nitrogen fixation rate of the hierarchical Bi2WO6 nanostructures was estimated to be 948 µmol g-1 h-1 across the full spectrum, which was 23% higher than that of the dispersed nanosheets (770 µmol g-1 h-1) due to chemisorption on the hierarchical structures and enhanced surface oxygen vacancies (OVs).
ABSTRACT
Ginkgo biloba is a dioecious plant. Male ginkgoes are mainly used in landscaping, while females are mainly used for fruit production. However, sex identification of ginkgo is a difficult task, especially at the seedling stage. In this work, we present for the first time the use of electrochemical techniques for the identification of ginkgo sex based on the differences in peroxides within male and female ginkgos. Graphene was used to concentrate peroxides in ginkgo extract, thereby improving electrochemical signal sensitivity. The electrochemical reduction of hydrogen peroxide catalyzed by peroxidase was used as a prob for sex determination in ginkgo. This electrochemical identification technique can be used not only for the analysis of adult ginkgo, but also successfully for the analysis of tissue culture seedlings and live seedlings. This electrochemical sensor has excellent discrimination ability due to the difference in peroxidase content in the leaves and petiole of ginkgo of different sexes. This electrochemical sensor allows for a rapid identification of the sex of ginkgo and has a very strong potential for field analysis.
Subject(s)
Biocatalysis , Ginkgo biloba/genetics , Peroxidase/metabolism , Electrochemistry , Ginkgo biloba/enzymology , Sex Determination AnalysisABSTRACT
Water pollution is a global environmental problem that has attracted great concern, and functional carbon nanomaterials are widely used in water treatment. Here, to optimize the removal performance of both oil/organic matter and dye molecules, we fabricated porous and hydrophobic core-shell sponges by growing graphene on three-dimensional stacked copper nanowires. The interconnected pores between the one-dimensional nanocore-shells construct the porous channels within the sponge, and the multilayered graphene shells equip the sponge with a water contact angle over 120° even under acidic and alkaline environments, which enables fast and efficient cleanup of oil on or under the water. The core-shell sponge can absorb oil or organic solvents with densities 40-90 times its own, and its oil-sorption capacity is much larger than those of other porous materials like activated carbon and loofah. On the other hand, the adsorption behavior of the core-shell sponge to dyes including methyl orange (MO) and malachite green (MG), also common water pollutants, was also measured. Dynamic adsorption of MG under cyclic compression demonstrated a higher adsorption rate than that in the static state, and an acidic environment was favorable for the adsorption of MO molecules. Finally, the adsorption isotherm for MO molecules was analyzed and fitted with the Langmuir model, and the adsorption kinetics were studied in depth as well.
ABSTRACT
A biosensor has been developed based on disposable screen-printed electrode for recording the electrochemical fingerprint of plant leaf tissue. A thin layer of polydopamine functionalized graphene sheets was coated on the plant tissue modified electrode for signal enhancement. The voltammetric data recorded under different buffer solutions can be derived as patterns for species identification. As the distribution of electrochemical active compounds in plants is controlled by genes, these fingerprints can reflect differences at the genetic level between species. Therefore, the electrochemical fingerprint of plant tissues can be used for phylogenetic research without qualitative analysis. 19 species of Amaryllidaceae including A. africanus, Clivia miniata, Clivia nobilis, Crinum firmifolium, Crinum latifolium, Crinum moorei, Curculiga gracilis, Cyrtanthus breviflorus, Habranthus robustus, Haemanthus albiflos, Haemathus multiflorus, Hippeastrum rutilum, Hymenocallis littoralis, Leucojum aestivum, Sprekelia formosissima, Tulbaghia violacea, Zephyranthes grandiflora, Zephyranthes macrosiphon and Zephyranthes minima have been selected deliberately. The dendrogram deduced from the electrochemical fingerprint was compared with the molecular phylogenetics. The results indicate the electrochemical fingerprint-based phylogenetic study is a persuasive methodology for plant phylogenetic analysis.
Subject(s)
Amaryllidaceae/chemistry , Biosensing Techniques , Electrochemical Techniques , Phylogeny , Plants/classification , Plants/geneticsABSTRACT
A self-made saturable absorber (SA) based on hybridized graphene oxide (GO) and ${{\rm Fe}_{3}}{{\rm O}_{4}}$Fe3O4 nanoparticles (FONP) was inserted into a linear cavity to generate a passively $ Q $Q-switched solid-state ${\rm Nd}\text:{{\rm YVO}_4}$Nd:YVO4 laser operating at the 1.3 µm waveband. The laser had a minimum pulse width of 163 ns and a maximum repetition rate of 314 kHz. This experiment, to the best of our knowledge, is the first to demonstrate that hybridized GO and FONP (GO-FONP) can be used as an SA in passively $ Q $Q-switched pulse lasers. Results show that GO-FONP has the potential to be used for passively $ Q $Q-switched laser generation.
ABSTRACT
The rapid identification of sex has potential uses involving dioecious commercial plants. In this work, we first propose a rapid electrochemical analysis method for plant sex determination using the signal difference generated by the electrochemically active substances in plant tissue. Polydopamine-functionalized graphene was wrapped around plant tissue. The introduction of polydopamine-functionalized graphene could solve the problem of the instability of plant tissue immobilization and enhance the electrochemical signals from plant tissue. Taxus × media, Dioscorea zingiberensis, and Dioscorea bulbifera were deliberately selected as dioecious plant models due to their pharmaceutical applications. The sex of the plant was not obvious after simply comparing the electrochemical voltammograms. Scatter patterns and 3D surface patterns were generated based on the voltammograms recorded after different solvent extractions. Sex determination was successfully achieved by pattern recognition.
ABSTRACT
Voltammetric scan can record the profile of electrochemical active substances in plant tissues. Because the distribution of chemical components in plants is controlled by genes, these profiles can reflect differences at the genetic level in different species. In this study, the voltammetric scan was applied to the investigation of macrophanerophytes taxonomy. All species of Chimonanthus with two exotaxa were deliberately selected due to their controversial infrageneric relationship. Electrode surface modification was excluded in this work to improve the convenience and accuracy of the fingerprint recording process. The dendrogram deduced from the electrochemical fingerprint data suggests that Ch. Zhejiangensis and Ch. grammatus are two groups of Ch. nitens, which may be only the ecotype of Ch. nitens, rather than independent taxonomic species. The small variations between the three species may be due to environmental factors and cannot be used for species formation. In addition, Ch. campanulatus and Ch. Praecox were clustered together with a close relationship.
Subject(s)
Calycanthaceae/chemistry , Plant Leaves/chemistry , Calycanthaceae/classification , Calycanthaceae/genetics , Electrochemical Techniques , Phylogeny , Plant Leaves/classification , Plant Leaves/geneticsABSTRACT
Mercury ions can significantly affect the organism and environment even at a very low concentration. Thus, great efforts have been devoted to developing high sensitive electrochemical sensors, especially the one that not only detect the mercury ions but also effective sensitive to thymine-Hg2+-thymine in aqueous solution. Metal-organic-frameworks (MOFs) possess hollow nature and are easy for grafting functional groups, however, there is still no attempts for working as electrochemical sensors in detecting mercury ions. Herein, we report a novel type sensor of Zr(IV)-based MOFs with specifically attached thioether side groups allowing mercury ions to be easily adsorbed and detected. The Zr(IV)-involved MOFs show strong binding to mercury ions compared with the bare MOFs, as confirmed by both experiment measurements and theoretical calculations. The as-prepared senor is sensitive ranging from 0.01â¯nM to 3⯵M with detection limitation of 7.3â¯fM, which is better than most of T-Hg2+-T- and enzyme-based sensors reported so far. The high sensitivity could be due to the straightforward adsorption pathway and the biomolecule exclusion nature of the Zr(IV)-involved MOFs sensor. We anticipate that our findings could pave the way for MOFs-based sensor exploration towards its commercial applications.
ABSTRACT
The identification of plant species not only is a hobby but also has important application value in plant resources science. Traditional plant identification often relies on the experience of botanists. The infrageneric identification of plants is easily mistaken due to similarities in organ features. In this work, we propose an electrochemical method to obtain fingerprints of plant petal tissue. Fourteen species of Lycoris were used as a model for validating this methodology. Pattern and color recognition were established for visualization of electrochemical fingerprints recorded after various solvent extractions. In addition, the infrageneric relationships of these Lycoris species were deduced from the electrochemical fingerprints since the type and content of electroactive compounds in plants are controlled by genes. The results indicate that the electrochemical fingerprints of Lycoris petals are correlated with the infrageneric relationships of native Lycoris species.
Subject(s)
Electrochemical Techniques/methods , Flowers/classification , Lycoris/classification , Adsorption , Flowers/chemistry , Graphite/chemistry , Lycoris/chemistry , Plant Extracts/chemistry , Plant Extracts/classification , Solvents , Species SpecificityABSTRACT
Graphene-embedded plant tissues show a high sensitivity to electrochemical signals, which enables a screen-printed electrode to be used for electrochemical fingerprint recording. The electrochemical fingerprints obtained under different conditions can be transformed into multidimensional recognition modes for plant identification. These electrochemical fingerprints reflect the types and quantities of the electrochemically active substances in plant tissues such that the fingerprints can be used for chemotaxonomic investigations. In this paper, five species of Lycoris bulbs, including L. chinensis, L. radiate, L. aurea, L. sprengeri and L. straminea, were successfully recognized by electrochemical fingerprinting. The species's interspecific relationships were also investigated. L. chinensis and L. aurea show highly similar morphology but have a relatively distant relationship. Hybridized L. radiata shows a notably close relationship with L. straminea, suggesting that one of its parents may be L. radiata. In addition, L. chinensis also shows a close relationship with L. straminea, suggesting that the L. straminea may be produced by cross-breeding L. chinensis and L. radiate. The results mentioned above indicate that the proposed electro-chemotaxonomic methodology is an inexpensive and quick taxonomic method that can provide additional evidence for the existing taxonomy system.