Hierarchical porosity and functionalization help to fully make use of metal–organic frameworks (MOFs) for their diverse applications. Herein, a simple strategy is reported to construct hierarchically ...porous MOFs through a competitive coordination method using tetrafluoroborate (M(BF4)x, where M is metal site) as both functional sites and etching agents. The resulting MOFs have in situ formed defect‐mesopores and functional sites without sacrificing their structure stability. The formation mechanism of the defect‐mesopores is elucidated by a combination of experimental and first‐principles calculation method, indicating the general feasibility of this new approach. Compared with the original microporous counterparts, the new hierarchical MOFs exhibit superior adsorption for the bulky dye molecules and catalytic performance for the CO2 conversion attributed to their specific hierarchical pore structures.
A simple and novel strategy is reported to fabricate a series of hierarchically porous metal–organic frameworks through the competitive coordination method. The formation mechanism of defect‐mesopores is elucidated by a combination of experimental and first‐principles calculation methods. Furthermore, the adsorption and catalytic advantage over the original microporous counterparts is also demonstrated attributed to their specific hierarchical pore structures.
The homojunction of oxygen/metal vacancies and its interfacial n–p effect on the physiochemical properties are rarely reported. Interfacial n–p homojunctions of TiO2 are fabricated by directly ...decorating interfacial p‐type titanium‐defected TiO2 around n‐type oxygen‐defected TiO2 nanocrystals in amorphous–anatase homogeneous nanostructures. Experimental measurements and theoretical calculations on the cell lattice parameters show that the homojunction of oxygen and titanium vacancies changes the charge density of TiO2; a strong EPR signal caused by oxygen vacancies and an unreported strong titanium vacancies signal of 2D 1H TQ‐SQ MAS NMR are present. Amorphous–anatase TiO2 shows significant performance regarding the photogeneration current, photocatalysis, and energy storage, owing to interfacial n‐type to p‐type conductivity with high charge mobility and less structural confinement of amorphous clusters. A new “homojunction of oxygen and titanium vacancies” concept, characteristics, and mechanism are proposed at an atomic‐/nanoscale to clarify the generation of oxygen vacancies and titanium vacancies as well as the interface electron transfer.
The homojunction of oxygen and titanium vacancies developed in the amorphous–anatase interface of nanostructured TiO2 results in a unique n–p electronic transmission, which is mostly preferred to the mobility of electronic charge carriers. It also contributes to significant performance regarding photogeneration current, photocatalysis, and energy storage.
A considerable amount of leachate with high fulvic acid (FA) content is generated during the municipal solid waste (MSW) incineration process. This incineration leachate is usually processed by ...downstream bio-methanogenic treatment. However, few studies have examined the impact that these compounds have on methanogenesis and how they are degraded and transformed during the treatment process. In this study, a laboratory-scale expanded granular sludge bed (EGSB) reactor was operated with MSW incineration leachate containing various concentrations of FA (1500 mg/L to 8000 mg/L) provided as the influent. We found that FA degradation rates decreased from 86% to 72% when FA concentrations in the reactor were increased, and that molecular size, level of humification and aromatization of the residual FA macromolecules all increased after bio-methanogenic treatment. Increasing FA influent concentrations also inhibited growth of hydrogenotrophic methanogens from the genus Methanobacterium and syntrophic bacteria from the genus Syntrophomonas, which resulted in a decrease in methane production and a concomitant increase in CO2 content in the biogas. Sequences most similar to species from the genus Anaerolinea went up as FA concentrations increased. Bacteria from this genus are capable of extracellular electron transfer and may be using FA as an electron acceptor for growth or as a shuttle for syntrophic exchange with other microorganisms in the reactor. In order to determine whether FA could serve as an electron shuttle to promote syntrophy in an anaerobic digester, co-cultures of Geobacter metallireducens and G. sulfurreducens were grown in the presence of FA from raw leachate or from residual bioreactor effluent. While raw FA stimulated electron transfer between these two bacteria, residual FA did not have any electron shuttling abilities, indicating that FA underwent a significant transformation during the bio-methanogenic treatment process. These results are significant and should be taken into consideration when optimizing anaerobic bioreactors used to treat MSW incineration leachate high in FA content.
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•High fulvic acid content adversely affects methanogenesis in anaerobic digesters.•Humification and aromatization of fulvic acids increases during biomethanogenesis.•Fulvic acids from incineration leachate can promote syntrophy between bacteria.•Treated fulvic acids lose their electron shuttling capabilities.•Microbial community structure is impacted by the presence of fulvic acids.
How often, and in what contexts, have archaeologists discussed racism over the last four decades? Do societal events lead to sustained discussions of racism among the academic community? Here, the ...authors seek to answer these questions by applying computational text analysis methods to 68176 abstracts from 41 meetings of the Society for American Archaeology. Discussions of racism are found to be rare—usually a passing mention in the context of broader social issues. Historical archaeologists have addressed racism more frequently than other archaeologists. The results form a baseline against which the discipline's engagement with racism as a research theme and with anti-racist strategies might be tracked.
Eleven new meroterpenoids, bipolahydroquinones A–C (1–3), cochlioquinones I–N (4–8 and 11), and isocochlioquinones F and G (9 and 10), together with six known ones, were obtained from an endophytic ...fungus Bipolaris sp. L1-2 from Lycium barbarum. Compound 2 is the first example of cochlioquinone derivatives possessing a benzofuran moiety. The structures and absolute configurations of the new compounds were elucidated by spectroscopic data interpretation, single-crystal X-ray diffraction analysis, chemical transformations, and biosynthetic considerations. Compounds 3, 4, and 6–8 showed cytotoxicity against NCI-H226 and/or MDA-MB-231 with IC50 values ranging from 5.5 to 9.5 μM.
This paper reported that the peroxidase-like activity of DNA-Ag/Pt nanoclusters (NCs) can be inhibited significantly by l-cysteine. Based on this finding, a highly sensitive and selective ...colorimetric detection for l-cysteine was developed with a detection limit (LOD) of 2.0nM and a linear range from 5.0nM to 500nM. This detection for l-cysteine was highly selectivity over other amino acids. The high sensitivity and selectivity of this method facilitated the detection of l-cysteine in biological samples. Moreover, this method developed here was low-cost and simple. These results indicated the excellent analytical application of Ag/Pt NCs as enzyme mimic.
SUMMARY
The sex of dioecious plants is mainly determined by genetic factors, but it can also be converted by environmental cues such as exogenous phytohormones. Gibberellic acids (GAs) are well‐known ...inducers of flowering and sexual development, yet the pathway of gibberellin‐induced sex conversion in dioecious spinach (Spinacia oleracea L.) remains elusive. Based on sex detection before and after GA3 application using T11A and SSR19 molecular markers, we confirmed and elevated the masculinization effect of GA on a single female plant through exogenous applications of GA3, showing complete conversion and functional stamens. Silencing of GIBBERELLIC ACID INSENSITIVE (SpGAI), a single DELLA family protein that is a central GA signaling repressor, results in similar masculinization. We also show that SpGAI can physically interact with the spinach KNOX transcription factor SHOOT MERISTEMLESS (SpSTM), which is a homolog of the flower meristem identity regulator STM in Arabidopsis. The silencing of SpSTM also masculinized female flowers in spinach. Furthermore, SpSTM could directly bind the intron of SpPI to repress SpPI expression in developing female flowers. Overall, our results suggest that GA induces a female masculinization process through the SpGAI‐SpSTM‐SpPI regulatory module in spinach. These insights may help to clarify the molecular mechanism underlying the sex conversion system in dioecious plants while also elucidating the physiological basis for the generation of unisexual flowers so as to establish dioecy in plants.
Significance Statement
Using environmental factors such as hormones to induce sex conversion is an important approach to studying dioecy sex differentiation, which is a special character closely related to flowering, reproduction, and fruiting. In our research, exogenous GA3 can induce functional masculinization of individual spinach, and the GA‐regulating pathway was established: GA‐SpGAI‐SpSTM‐SpPI. This study provides new ideas and theoretical support for studying the sex differentiation mechanisms of spinach and other dioecious plants.
Echinococcosis is a zoonotic parasitic disease caused by larval stages of cestodes belonging to the genus Echinococcus. The infection affects people's health and safety as well as agropastoral ...sector. In China, human echinococcosis is a major public health burden, especially in western China. Echinococcosis affects people health as well as agricultural and pastoral economy. Therefore, it is important to understand the prevalence status and spatial distribution of human echinococcosis in order to advance our knowledge of basic information for prevention and control measures reinforcement.
Report data on echinococcosis were collected in 370 counties in China in 2018 and were used to assess prevalence and spatial distribution. SPSS 21.0 was used to obtain the prevalence rate for CE and AE. For statistical analyses and mapping, all data were processed using SPSS 21.0 and ArcGIS 10.4, respectively. Chi-square test and Exact probability method were used to assess spatial autocorrelation and spatial clustering.
A total of 47,278 cases of echinococcosis were recorded in 2018 in 370 endemic counties in China. The prevalence rate of human echinococcosis was 10.57 per 10,000. Analysis of the disease prevalence showed obvious spatial positive autocorrelation in globle spatial autocorrelation with two aggregation modes in local spatial autocorrelation, namely high-high and low-high aggregation areas. The high-high gathering areas were mainly concentrated in northern Tibet, western Qinghai, and Ganzi in the Tibetan Autonomous Region and in Sichuan. The low-high clusters were concentrated in Gamba, Kangma and Yadong counties of Tibet. In addition, spatial scanning analysis revealed two spatial clusters. One type of spatial clusters included 71 counties in Tibet Autonomous Region, 22 counties in Qinghai, 11 counties in Sichuan, three counties in Xinjiang Uygur Autonomous Region, two counties in Yunnan, and one county in Gansu. In the second category, six types of spatial clusters were observed in the counties of Xinjiang Uygur Autonomous Region, and the Qinghai, Gansu, and Sichuan Provinces.
This study showed a serious prevalence of human echinococcosis with obvious spatial aggregation of the disease prevalence in China. The Qinghai-Tibet Plateau is the "hot spot" area of human echinococcosis in China. Findings from this study indicate that there is an urgent need of joint strategies to strengthen efforts for the prevention and control of echinococcosis in China, especially in the Qinghai-Tibet Plateau.
Abstract Background MicroRNAs (miRNAs) are endogenous small RNAs of 21–25 nucleotides that post-transcriptionally regulate gene expressions. Recently, circulating miRNAs have been reported as ...promising biomarkers for neurodegenerative disorders and processes affecting the central nervous system. This study was conducted to investigate the potential role of serum miRNAs as diagnostic biomarkers for Alzheimer's disease (AD). Methods Serum samples were obtained from 105 probable AD patients and 150 age- and gender-matched normal controls. The serum concentrations of miRNAs miR-9, miR-29a, miR-29b, miR-101, miR-125b, and miR-181c were measured with a real-time quantitative reverse transcriptase PCR (qRT-PCR) method. Results We found both miR-125b and miR-181c were down-regulated while miR-9 was up-regulated in serum of AD patients compared with that of normal controls. Among the receiver operating characteristic (ROC) results, miR-125b alone showed its priority with a specificity up to 68.3% and a sensitivity of 80.8%. Importantly, miR-125b was correlated with the Mini Mental State Examination (MMSE) in AD patients. Conclusions Our results indicate that serum miR-125b may serve as a useful noninvasive biomarker for AD.
To strengthen the effectiveness of resveratrol (RES) as a natural antioxidant in food systems, this work attempted to enhance the water solubility of RES by utilizing the solubilizing properties of ...stevioside (STE) and investigated the effect of STE-solubilized RES (STE–RES) incorporation on the stability of soy protein isolate (SPI)-based emulsions. The physical properties and oxidative stability of SPI emulsions with STE/STE–RES were evaluated. The water solubility of RES increased with the increase of STE concentration up to its critical micelle concentration, suggesting the solubilization of hydrophobic RES in STE self-assembled micelles. STE micelles competitively adsorbed at the oil–water interface with SPI, forming a mixed SPI and STE interfacial layer, thus resulting in a decrease in particle size and evident enhancement in the physical stability of SPI-based emulsions. After the incorporation of STE–RES, SPI emulsions showed an enhanced oxidative stability with reduced lipid hydroperoxides and volatile hexanal. This improvement was believed to be mainly attributed to the targeted migration of RES to the interface during the adsorption of the STE–RES complex, as evidenced by high interfacial accumulation of RES.
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