Catalytic conversion of seawater to fuels: Eliminating N vacancies in g-C3N4 to promote photocatalytic hydrogen production.

The use of solar energy to decompose seawater and produce hydrogen is of great significance in solving the energy crisis. Numerous studies have shown that vacancies can significantly improve photocatalytic activity due to their electron-rich nature. However, our recent research has shown that materials with vacancies are not suitable for photocatalytic reactions in seawater. In this study, g-C3N4 with rich N vacancies was selected as the research object, and urea was used as the precursor; in this system, the N vacancies in g-C3N4 could be effectively reduced by the addition of ZIF-8 (ZCNQx). The activity of ZCNQ40 was 5.6 times higher than that of g-C3N4 in fresh seawater, but only 3.1 times higher in freshwater. Based on the analysis of the experimental results, we believe that g-C3N4 has a limiting relationship between H+ adsorption catalysis and H2 product desorption. In addition, seawater contains many heteroatoms that will also compete with proton (H+) reduction. The results of our study show that catalysts with vacancies are not necessarily suitable for catalytic reactions in seawater media. This research will stimulate new ideas for research into the conversion of solar energy to chemical energy in seawater media.

The enhanced photocatalytic inactivation of marine microorganisms over ZnO supported Ag quantum dots by the synthesis of H2O2.

The production of hydroxyl radicals has been demonstrated to improve the antifouling of marine through a photocatalytic strategy. However, only relying on the valence band of the photocatalyst to generate hydroxyl radicals is inefficient and limits the application of photocatalytic technology in the field of marine-antifouling coatings. Herein, we reported a new strategy in which Ag quantum dots are used to synthesize hydrogen peroxide (H2O2) by photocatalysis in seawater. The decomposition of the generated H2O2 to hydroxyl radicals improves the antifouling ability. Interestingly, the prominent size effect of Ag quantum dots is closely related to the yield of H2O2. We synthesized Ag quantum dots supported on ZnO and found that Ag quantum dots approximately 4 nm in size have the highest activity for H2O2 generation and undergo a 1 h photocatalytic reaction in which the concentration of H2O2 can reach 124 µg/mL. The efficiency of ZnO in inactivating marine microorganisms increased from 72.3% to 99.4% in seawater. The synthesis of H2O2 through photocatalysis based on the medium of seawater can expand the application of photocatalytic technology in the field of marine antifouling.

Morphology modulation and performance optimization of nanopetal-based Ag-modified Bi2O2CO3 as an inactivating photocatalytic material.

The use of photocatalytic technology to kill bacteria on marine vessel surface coatings has been paid more attention by research scholars. In this paper, petal-like microspheres with Ag nanoparticles were prepared by a simple one-step process combining the hydrothermal method and photodeposition. The 0.7% Ag/Bi2O2CO3 composite photocatalyst exhibited the highest photocatalytic efficiency for bacterial removal under visible light irradiation and had the highest photogenerated carrier separation efficiency, and the sterilization rate was doubled compared with that of pure Bi2O2CO3, reaching 95%. Using X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy, the existence of Ag nanoparticles was confirmed, and their size was approximately 10 nm. The surface plasmon resonance (SPR) effect of Ag nanoparticles was investigated by ultraviolet-visible diffuse reflectance spectroscopy (DRS). It was shown that the surface plasmon resonance effect of Ag improved the spectral utilization of the Ag/Bi2O2CO3 composite photocatalyst and enhanced the stability of the catalyst. This caused the Ag/Bi2O2CO3 composite photocatalyst to have superior photocatalytic activity to pure Bi2O2CO3. The results of electrochemical impedance characterization and transient photocurrent response show that 0.7% Ag/Bi2O2CO3 has a high efficiency of photogenerated carrier separation. By the free radical capture test, hydroxyl radicals were the primary active substance, and Ag+ improved the photocatalytic sterilization activity.

Investigating the frequency-dependent amplification of a tapered amplifier in atom interferometers.

We present the investigation on the frequency-dependent amplification (FDA) of a tapered amplifier (TA) and the corresponding influence on Raman-type atom interferometers. In our interferometer, the output of two phase-locked diode lasers is injected into a TA to generate Raman beams. The frequency of one laser is chirped during the interfering process, which induces a variance of the Raman lasers power as a result of the FDA of the TA. The corresponding power ratio variation of the Raman lasers is measured by beat note method, which shows a linear dependence with a slope of -0.087(4)/GHz when the laser frequency changes over 2 GHz at 780 nm. The corresponding error related to AC Stark effect due to this frequency-dependent variation is estimated for our atom interferometer. The investigation presented here may provide hints for other experiments involving TAs.

Mutations in the p16 gene in DMBA-induced pancreatic intraepithelial neoplasia and pancreatic cancer in rats.

BACKGROUND: 7, 12-dimethylbenzanthracene (DMBA)-induced pancreatic intraepithelial neoplasia (PanIN) and pancreatic cancer in rats provide a classic model for uncovering the molecular mechanisms underlying pancreatic cancer. However, this model has not been characterized genetically, and in particular, the major genetic alterations in the p16 gene are unknown. METHODS: Lesions of PanIN and pancreatic cancer were induced with DMBA implantation in 40 rats, and control pancreatic tissue was obtained from 10 age-matched rats without exposure to DMBA. Pancreatic tissue was harvested three months after DMBA implantation and DNA was extracted. Homozygous deletions and point mutations of the p16 (exons 1 and 2) gene were detected by PCR amplification and direct sequencing. RESULTS: DMBA implantation in the 40 rats induced 26 PanINs and 9 carcinomas. The overall frequency of p16 alterations in the pancreatic tissue of these rats was 42.86% (15/35), and the changes were point mutations, not homozygous deletions. p16 mutations were present in 30.77% (8/26) of the rats with PanIN and 77.78% (7/9) of the rats with carcinoma (P<0.05). The increasing incidence of p16 alterations was detected in 20.00% (1/5) of PanIN-1, 28.57% (2/7) of PanIN-2 and 35.71% (5/14) of PanIN-3 lesions. CONCLUSION: Our findings indicated that p16 alteration is a common event in the carcinogenesis of this model and that the mutation pattern is analogous to that of human lesions.

[Preparation of Tb3+, Yb3+ doped Y2O3 luminescent powders and near-infrared quantum cutting research].

Y2O3:Tb3+ and Y2O3:Tb3+, Yb3+ samples were prepared by co-precipitation method. The morphology, microstructure and fluorescence spectra at room temperature of samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and fluorescence spectrometer, The optimal process conditions of Y2O3:Tb3+ under different doping concentrations, annealing temperature, and pH value of the solution were obtained: Tb3+ concentration is 1.5%, annealing temperature is 1400 degrees C, an alkaline solution environment, and samples under 300 nm light excitation have the largest green light emission at 543 nm. The corresponding relation of Tb3+ ion level structure and transition properties and experimental spectra were analyzed in detail, and we explained the influence mechanism of process conditions and the fluorescence quenching process mainly effects luminous intensity of samples. The energy transfer from sensitizing ions Tb3+ to active ion Yb3+ was confirmed, it made the sample have considerable emitting light in the near-infrared region; the authors described the process of cooperation conversion luminescence between the two ions from the level transition angle, and also analyzed the system of fluorescence quenching process. Test results showed that the near infrared quantum cutting can effectively improve the luminous efficiency of doped ions, and will have broad application prospects in the silicon solar cells and other fields.

Contribution of murine bone marrow mesenchymal stem cells to pancreas regeneration after partial pancreatectomy in mice.

The implantation of BMSCs (bone marrow mesenchymal stem cells) has emerged as a potential method of treating tissue damage, but the in vivo differentiation of BMSCs in an injured pancreas and its therapeutic effects have not been determined. Our aim has been to investigate the potential of BMSCs to contribute to the parenchyma and mesenchymal components of the pancreas during rapid regeneration, with preliminary exploration of the molecular mechanisms of this process. GFP(+) (green fluorescent protein(+) ) BMSCs were intravenously infused into the tail veins of mice that had received a 65-70% partial pancreatectomy, while mice that had only received a partial pancreatectomy and mice that had only been injected with BMSCs served as controls. Four weeks later, the injected GFP(+) BMSCs were diffusely engrafted in the pancreatic parenchyma and mesenchyma of the recipient mice with pancreatic injuries and had differentiated into pancreatic ductal epithelial cells (accounting for 1.7±0.3%), vascular endothelial cells (3.2±0.6%) and PSCs (pancreatic stellate cells) (5.2±1.6%), but no ß or neural cells. Significantly, more engrafted and differentiated GFP(+) BMSCs were observed in the regenerating pancreas than in the normal pancreas. For the mice that received a partial pancreatectomy, the pancreatic weight/body weight of the mice with BMSC treatment was greater than mice without BMSC treatment (P<0.05). In addition, real-time RT-PCR (reverse transcription-PCR) showed that the expression levels of miR-9 (microRNA 9) and miR-204 in the engrafted BMSCs (5.2- and 2.6-fold, P<0.05, respectively) were increased compared with wild-type BMSCs. We also observed a significant reduction in the expression of miR-375 (0.71-fold, P<0.05) in engrafted GFP(+) BMSCs compared with wild-type BMSCs. BMSCs can therefore be a potential cell bank for treating pancreatic injuries by contributing to a variety of cell types. This process might be related to the expression of miR-9, miR-204 and miR-375.

Short video users' personality traits and social sharing motivation.

Purpose/significance: Studying the correlation between short video users' personality traits and their sharing motivation can enrich the theoretical research on social sharing motivation and provide a reference for short-video content management and platform construction. Methods/process: Based on uses and gratifications theory and personality traits theory, a structural model affecting short-video users' sharing motivations was proposed. A total of 579 valid questionnaires were collected from a social network, and the proposed hypotheses were tested using SPSS and Amos software. Results/conclusion: The results show that the personality traits of short-video users affect their sharing motivation and that their specific sharing motivation also differ due to their personality traits. At the same time, the research results also confirm the Matthew effect of "the rich getting richer" and the social compensation effect of "the poor getting richer" in the context of social platforms that host short videos.

A Tandem Reaction System for Inactivation of Marine Microorganisms by Commercial Carbon Black and Boron-Doped Carbon Nitride.

The Pureballast system, based on photocatalytic technology, can purify ships' ballast water. However, the efficiency of photocatalytic sterilization still needs to be improved due to the shortcomings of the photocatalyst itself and the complex components of seawater. In this work, a tandem reaction of electrocatalytic synthesis and photocatalytic decomposition of hydrogen peroxide (H2O2) was constructed for the inactivation of marine microorganisms. Using seawater and air as raw materials, electrocatalytic synthesis of H2O2 by commercial carbon black can avoid the risk of large-scale storage and transportation of H2O2 on ships. In addition, boron doping can improve the photocatalytic decomposition performance of H2O2 by g-C3N4. Experimental results show that constructing the tandem reaction is effective, inactivating 99.7% of marine bacteria within 1 h. The sterilization efficiency is significantly higher than that of the single way of electrocatalysis (52.8%) or photocatalysis (56.9%). Consequently, we analyzed the reasons for boron doping to enhance the efficiency of g-C3N4 decomposition of H2O2 based on experiments and first principles. The results showed that boron doping could significantly enhance not only the transfer kinetics of photogenerated electrons but also the adsorption capacity of H2O2. This work can provide some reference for the photocatalytic technology study of ballast water treatment.

PWT1, an avirulence gene of Magnaporthe oryzae tightly linked to the rDNA Locus, is recognized by two staple crops, common wheat and barley.

The pathogenicity to wheat (Pwt1) locus conditions host species specificity of Magnaporthe oryzae on wheat. GFSI1-7-2 (Setaria isolate) carries the avirulence allele (PWT1) at this locus while Br48 (Triticum isolate) carries the virulence allele (pwt1). An F(1) culture derived from a cross between GFSI1-7-2 and Br48 was backcrossed with Br48 to produce a tester population in which PWT1 alone segregated. When hexaploid wheat lines were inoculated with the BC(1)F(1) testers, they were all resistant to all PWT1 carriers and susceptible to all pwt1 carriers, suggesting that they recognize PWT1. When barley cultivars were inoculated with the testers, they showed the same pattern of reactions as the hexaploid lines, suggesting that the barley cultivars also recognize PWT1. These results suggest that PWT1 is a fundamental gene that universally conditions the avirulence of Setaria isolates on two staple crops, hexaploid wheat and barley. Interestingly, tetraploid wheat lines did not recognize PWT1. Molecular mapping using the F(1) and BC(1)F(1) populations revealed that the Pwt1 locus is located on chromosome 2 and tightly linked to the ribosomal DNA locus and a telomere.

Near Infrared Quantum Cutting of Tb3+-Yb3+ Co-Doped CeF3 Nanophosphors.

In this paper, Tb3+-Yb3+ Co-doped CeF3 nanophosphors were synthesized using the microwave-assisted heating hydrothermal method (M-H). The excitation and emission spectra of the samples at room temperature show that the samples absorb ultraviolet light from 250 nm to 280 nm, and emit light at 300 nm. This corresponds to the transitions from 5D to 4F of Ce3+, 480 nm, 540 nm, 583 nm, 620 nm which correspond to the transitions from 5D4 to 7F6,5,4,3 of Tb3+, 973 nm which corresponds to the transitions from 2F5/2-2F7/2 of Yb3+. In the emission spectra, it is clear that the emission intensity of Ce3+ and Tb3+ decreases, and Yb3+ increases with increasing Yb3+. This suggests that energy transfer from Ce3+ to Yb3+, and Ce3+ to Tb3+ to Yb3+ may occur. In the near infrared emission area, it is noted that a distinct emission centered at 973 nm was observed under 260 nm excitation. This is due to transitions among the different Stark levels of 2FJ(J=5/2,7/2) Yb3+ ions. This also suggests an energy transfer from Ce3+ ions to Tb3+ and then to Yb3+. The energy transfers from Tb3+-Yb3+ Co-doped CeF3 nanophosphors, which lead to intense NIR emissions at 900-1050 nm, match the energy of Si band gaps of Si-based solar cells. Therefore, these kinds of materials are promising candidates for applications that require modifying if solar spectrums and enhancement of conversion efficiency of Si-based solar cells.

α1-Adrenoceptors in the hippocampal dentate gyrus involved in learning-dependent long-term potentiation during active-avoidance learning in rats.

The hippocampus is the key structure for learning and memory in mammals and long-term potentiation (LTP) is an important cellular mechanism responsible for learning and memory. The influences of norepinephrine (NE) on the modulation of learning and memory, as well as LTP, through ß-adrenoceptors are well documented, whereas the role of α1-adrenoceptors in learning-dependent LTP is not yet clear. In the present study, we measured extracellular concentrations of NE in the hippocampal dentate gyrus (DG) region using an in-vivo brain microdialysis and high-performance liquid chromatography techniques during the acquisition and extinction of active-avoidance behavior in freely moving conscious rats. Next, the effects of prazosin (an antagonist of α1-adrenoceptor) and phenylephrine (an agonist of the α1-adrenoceptor) on amplitudes of field excitatory postsynaptic potential were measured in the DG region during the active-avoidance behavior. Our results showed that the extracellular concentration of NE in the DG was significantly increased during the acquisition of active-avoidance behavior and gradually returned to the baseline level following extinction training. A local microinjection of prazosin into the DG significantly accelerated the acquisition of the active-avoidance behavior, whereas a local microinjection of phenylephrine retarded the acquisition of the active-avoidance behavior. Furthermore, in all groups, the changes in field excitatory postsynaptic potential amplitude were accompanied by corresponding changes in active-avoidance behavior. Our results suggest that NE activation of α1-adrenoceptors in the hippocampal DG inhibits active-avoidance learning by modulation of synaptic efficiency in rats.

Development of an unsupported arm exercise test in patients with chronic obstructive pulmonary disease.

BACKGROUND: Unsupported arm exercise tests have been used to evaluate the effects of pulmonary rehabilitation in patients with chronic obstructive pulmonary disease (COPD), but the reliability and validity of these tests are not established. OBJECTIVE: We evaluated the test-retest reliability and validity of a 6-minute pegboard and ring test (PBRT) in 27 outpatients with COPD and 30 age-matched controls. METHODS: We evaluated a 6-minute PBRT, subject demographics, pulmonary function and disease-specific quality of life questionnaire, and the Pulmonary Functional Status Dyspnea Questionnaire-Modified version in 27 patients with COPD. RESULTS: Highly significant correlation coefficients (r = .91, P < .001) were found between test and retest of PBRT scores. Statistically significant correlation coefficients were found between PBRT scores and pulmonary function tests such as FEV1% pred and FVC% pred, and activity domain and subdomain of Pulmonary Functional Status Dyspnea Questionnaire-Modified (P