12 research outputs found
UV Stimulated Manganese Dioxide for the Persulfate Catalytic Degradation of Bisphenol A
One of the most commonly produced industrial chemicals worldwide, bisphenol A (BPA),
is used as a precursor in plastics, resins, paints, and many other materials. It has been proved that
BPA can cause long-term adverse effects on ecosystems and human health due to its toxicity as an
endocrine disruptor. In this study, we developed an integrated MnO2/UV/persulfate (PS) process for
use in BPA photocatalytic degradation from water and examined the reaction mechanisms, degradation
pathways, and toxicity reduction. Comparative tests using MnO2, PS, UV, UV/MnO2, MnO2/PS,
and UV/PS processes were conducted under the same conditions to investigate the mechanism
of BPA catalytic degradation by the proposed MnO2/UV/PS process. The best performance was
observed in the MnO2/UV/PS process in which BPA was completely removed in 30 min with a
reduction rate of over 90% for total organic carbon after 2 h. This process also showed a stable
removal efficiency with a large variation of pH levels (3.6 to 10.0). Kinetic analysis suggested that 1O2
and SO4
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Biogeographic patterns and drivers of soil viromes
Viruses are crucial in shaping soil microbial functions and ecosystems. However, studies on soil viromes have been limited in both spatial scale and biome coverage. Here we present a comprehensive synthesis of soil virome biogeographic patterns using the Global Soil Virome dataset (GSV) wherein we analysed 1,824 soil metagenomes worldwide, uncovering 80,750 partial genomes of DNA viruses, 96.7% of which are taxonomically unassigned. The biogeography of soil viral diversity and community structure varies across different biomes. Interestingly, the diversity of viruses does not align with microbial diversity and contrasts with it by showing low diversity in forest and shrubland soils. Soil texture and moisture conditions are further corroborated as key factors affecting diversity by our predicted soil viral diversity atlas, revealing higher diversity in humid and subhumid regions. In addition, the binomial degree distribution pattern suggests a random co-occurrence pattern of soil viruses. These findings are essential for elucidating soil viral ecology and for the comprehensive incorporation of viruses into soil ecosystem models
A Comparative Study of the Use of Mesoporous Carbon and Mesoporous Silica as Drug Carriers for Oral Delivery of the Water-Insoluble Drug Carvedilol
Mesoporous carriers have been extensively applied to improve the dissolution velocity and bioavailability of insoluble drugs. The goal of this work was to compare the drug-loading efficiency (LE) and drug-dissolution properties of mesoporous silica nanoparticles (MSN) and mesoporous carbon nanoparticles (MCN) as drug vectors oral delivery of water-insoluble drugs. For this purpose, MSN and MCN with similar particle size, surface area, and mesoporous diameter were prepared to precisely evaluate the effects of different textures on the drug-loading and dissolution behavior of insoluble drugs. Carvedilol (CAR), a Bio-pharmaceutic Classification System (BCS) class II drug, was loaded in the MSN and MCN by the solvent adsorption method and solvent evaporation method with different carrier−drug ratios. The carboxylated MCN (MCN−COOH) had a higher LE for CAR than MSN for both the two loading methods due to the strong adsorption effect and π−π stacking force with CAR. In vitro drug dissolution study showed that both MSN and MCN-COOH could improve the dissolution rate of CAR compared with the micronized CAR. In comparison to MSN, MCN-COOH displayed a slightly slower dissolution profile, which may be ascribed to the strong interaction between MCN-COOH and CAR. Observation of cell cytotoxicity and gastrointestinal mucosa irritation demonstrated the good biocompatibility of both MSN and MCN−COOH. The present study encourages further research of different carriers to determine their potential application in oral administration
Dynamic analysis of correlation patterns between urban population and construction land at different administrative levels: The case of Hangzhou megacity
Understanding the urban human-land interaction at multiple administrative levels comprehensively plays an important role in the refined governance and thus provides critical references for urban planning and management. This paper analyzes the relationship between urban population and urban construction land in Hangzhou from perspectives of equilibrium, intensification and coordination at the multi-level during 2010 and 2020. Meanwhile, the underlying mechanism among the urban construction land expansion, population flow and land utilization efficiency with different demographic migration pattern is defined by Kaya identity and further quantitatively deconstructed by the Logarithmic Mean Divisia Index (LMDI). Regraded with the multi-level evaluation of human-land interactions, the prefectural-level analysis reveals significant reduction in both internal difference and absolute value of per capita urban construction land area, and the growth rate of urban population is 2.24 times faster than that of the urban construction land. At the county-level, the proportion of balanced and intensive county-level units increase by 15.38% and 38.46% respectively. The proportion of the county-level units under coordinated status reaches up to 92.31%. At the township-level, the proportion of intensive township-level units increases by 16.84% and the proportion of the township-level units under coordinated status is up to 64.74%. Furthermore, analysis of the multidimensional combination characteristics of urban human-land interaction is performed with six combination types at the county-level and four combination types at the township-level, which are useful for managers to develop categorized and refined urban development guidance. The driving mechanisms demonstrated that 47% of the townships with net population inflow and 41% of the townships with net population outflow are mainly influenced by the increase of permanent resident population, while the deterioration degree of land utilization efficiency in the former is significantly lower than that in the latter. This result implies that the townships in the core urban areas present the better performance in the improvement of land utilization efficiency than those in the western areas of Hangzhou. The exploration will provide references for coordinating the rational allocation of land resources and optimizing the regional human-land relationship
A feasible framework to downscale NPP-VIIRS nighttime light imagery using multi-source spatial variables and geographically weighted regression
10.1016/j.jag.2021.102513International Journal of Applied Earth Observation and Geoinformation10410251
Identifying and classifying shrinking cities using long-term continuous night-time light time series
10.3390/rs13163142Remote Sensing1316314
Relationship between serum homocysteine level and cognitive impairment in patients with Parkinson‘s disease
OBJECTIVE To investigate the correlation between serum homocysteine (Hcy) and cognitive impairment (CI) in patients with Parkinson’s disease (PD)
MicroRNA programs in normal and aberrant stem and progenitor cells
Emerging evidence suggests that microRNAs (miRNAs), an abundant class of ∼22-nucleotide small regulatory RNAs, play key roles in controlling the post-transcriptional genetic programs in stem and progenitor cells. Here we systematically examined miRNA expression profiles in various adult tissue-specific stem cells and their differentiated counterparts. These analyses revealed miRNA programs that are common or unique to blood, muscle, and neural stem cell populations and miRNA signatures that mark the transitions from self-renewing and quiescent stem cells to proliferative and differentiating progenitor cells. Moreover, we identified a stem/progenitor transition miRNA (SPT-miRNA) signature that predicts the effects of genetic perturbations, such as loss of PTEN and the Rb family, AML1-ETO9a expression, and MLL-AF10 transformation, on self-renewal and proliferation potentials of mutant stem/progenitor cells. We showed that some of the SPT-miRNAs control the self-renewal of embryonic stem cells and the reconstitution potential of hematopoietic stem cells (HSCs). Finally, we demonstrated that SPT-miRNAs coordinately regulate genes that are known to play roles in controlling HSC self-renewal, such as Hoxb6 and Hoxa4. Together, these analyses reveal the miRNA programs that may control key processes in normal and aberrant stem and progenitor cells, setting the foundations for dissecting post-transcriptional regulatory networks in stem cells