The dissolution and controlled release of poorly water soluble drugs have been challenging during the past half century. Food ingredients are often exploited to implement some strategies to conceive ...new drug delivery systems as potential solutions. In this study, Janus zein–PVP medicated nanofibers were fabricated through side-by-side electrospinning and by using zein as a key filament-forming matrix and a drug carrier. Ferulic acid (FA), as a poorly water-soluble model drug, was loaded on both sides of the Janus fibers. The side-by-side electrospinning process was performed for a smooth and robust preparation. SEM and TEM revealed that the resultant Janus fibers had linear morphology without beads-on-a-string phenomena, smooth surface, and obvious side-by-side structure. The FA was present in the fibers in an amorphous state due to its fine compatibility with zein and PVP. In vitro dissolution tests verified that the Janus fibers manipulated the release of FA in a two-stage manner. The controlled release mechanism of the Janus fibers was proposed. On the basis of the application of zein, a process–structure–performance relationship, which should be useful for developing many new functional materials from biological macromolecules, was disclosed.
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•Zein is utilized to create medicated Janus structure•A modified side-by-side electrospinning is implemented to treat zein•The Janus fibers can provide a two-stage controlled release of ferulic acid•A clear process-nanostructure-performance relationship is exhibited
Purpose
Microorganisms that inhabit at microhabitat of bulk soil, rhizosphere, and root play different roles in carbon and nutrient cycling, and their changes have differential impacts on plant ...community dynamics. However, there is an extensive knowledge deficit regarding how plant invasion affects soil microorganisms residing at different microhabitats of plant species being invaded and even those of the invader itself.
Methods
This study employed high-throughput sequencing of bacterial 16S rRNA genes and the fungal internal transcribed spacer (ITS) region to investigate the microbial community structure and function(s) of bulk soil, rhizosphere, and roots of a dominant native tree species (
Cyclobalanopsis glauca
) in a subtropical evergreen forest invaded and uninvaded by an invasive native species (
Phyllostachys edulis
, Moso bamboo), and that of the invader itself at both invaded and uninvaded forests. Moreover, we calculated the α-, β-diversity and phyla composition and predicted the function and co-occurrence network of microbes.
Results
The bacterial richness rather than fungal richness in bulk soil was observed to have increased after being invaded by bamboo. Both richness and co-occurrence network of the root-associated microbiomes of
C. glauca
declined after being invaded by bamboo, with a more drastic change in the rhizosphere than in roots. In the case of the bamboo, it was observed that bacterial networks had strengthened after they were invaded into the ambient forest as opposed to when they were in a monoculture, with a heavier change in root than in the rhizosphere. Furthermore, the changes in the root-associated microbial composition of
C. glauca
were mainly relevant for nutritional cycling, particularly bacteria responsible for nitrogen (N) cycling, implying the strengthened competition of
C. glauca
for nutrients after being invaded by bamboo.
Conclusion
This study revealed that the invasion of bamboo resulted in significant but differential changes in microbial community structure and related functions that were inhabited within the bulk soil, and at the rhizosphere, and roots of both dominant native tree species and the bamboo itself. A more profound observation was made where the invasive and non-invasive plants showed contrasting responses between rhizosphere and root after invasion or being invaded, with the rhizospheric microbes of non-invasive plants being more sensitive than that of roots, and the roots of invader were more sensitive than rhizosphere. The study findings have important implications for soil carbon and nutrients cycling and even community development of subtropical evergreen forests.
The COVID-19 pandemic caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has spurred unprecedented and concerted worldwide research to curtail and eradicate this pathogen. ...SARS-CoV-2 has four structural proteins: Envelope (E), Membrane (M), Nucleocapsid (N), and Spike (S), which self-assemble along with its RNA into the infectious virus by budding from intracellular lipid membranes. In this paper, we develop a model to explore the mechanisms of RNA condensation by structural proteins, protein oligomerization and cellular membrane–protein interactions that control the budding process and the ultimate virus structure. Using molecular dynamics simulations, we have deciphered how the positively charged N proteins interact and condense the very long genomic RNA resulting in its packaging by a lipid envelope decorated with structural proteins inside a host cell. Furthermore, considering the length of RNA and the size of the virus, we find that the intrinsic curvature of M proteins is essential for virus budding. While most current research has focused on the S protein, which is responsible for viral entry, and it has been motivated by the need to develop efficacious vaccines, the development of resistance through mutations in this crucial protein makes it essential to elucidate the details of the viral life cycle to identify other drug targets for future therapy. Our simulations will provide insight into the viral life cycle through the assembly of viral particles de novo and potentially identify therapeutic targets for future drug development.
HIV estimation using data from the demographic and health surveys (DHS) is limited by the presence of non‐response and test refusals. Conventional adjustments such as imputation require the data to ...be missing at random. Methods that use instrumental variables allow the possibility that prevalence is different between the respondents and non‐respondents, but their performance depends critically on the validity of the instrument. Using Manski's partial identification approach, we form instrumental variable bounds for HIV prevalence from a pool of candidate instruments. Our method does not require all candidate instruments to be valid. We use a simulation study to evaluate and compare our method against its competitors. We illustrate the proposed method using DHS data from Zambia, Malawi and Kenya. Our simulations show that imputation leads to seriously biased results even under mild violations of non‐random missingness. Using worst case identification bounds that do not make assumptions about the non‐response mechanism is robust but not informative. By taking the union of instrumental variable bounds balances informativeness of the bounds and robustness to inclusion of some invalid instruments. Non‐response and refusals are ubiquitous in population based HIV data such as those collected under the DHS. Partial identification bounds provide a robust solution to HIV prevalence estimation without strong assumptions. Union bounds are significantly more informative than the worst case bounds without sacrificing credibility.
Air pollution is a serious environmental problem that has attracted much attention. Air quality prediction can provide useful information for urban environmental governance decision-making and ...residents’ daily health control. However, existing research methods have suffered from a weak ability to capture the spatial correlations and fail to model the long-term temporal dependencies of air quality. To overcome these limitations, we propose a multi-scale spatiotemporal graph convolution network (MST-GCN), which consists of a multi-scale block, several spatial-temporal blocks and a fusion block. We first divide the extracted features into several groups based on their domain categories, and represent the spatial correlations across stations as two graphs. Then we combine the grouped features and the constructed graphs in pairs to form a multi-scale block that feeds into spatial-temporal blocks. Each spatial-temporal block contains a graph convolution layer and a temporal convolution layer, which can model the spatial correlations and long-term temporal dependencies. To capture the group interactions, we use a fusion block to fuse multiple groups. Extensive experiments on a real-world dataset demonstrate that our model achieves the highest performance compared with state-of-the-art and baseline models for air quality prediction.
Previous research has shown that simulation training using avatars with repeated feedback improves child sexual abuse interview quality. The present study added a hypothesis-testing intervention and ...examined if the combination of two interventions, feedback and hypothesis-testing, would improve interview quality compared to no intervention and to either intervention alone. Eighty-one Chinese university students were randomly assigned to a control, feedback, hypothesis-testing, or the combination of feedback and hypothesis-testing group and conducted five simulated child sexual abuse interviews online. Depending on the assigned group, feedback on the outcome of the cases and question types used in the interview were provided after each interview, and/or the participants built hypotheses based on preliminary case information before each interview. The combined interventions group and feedback group showed a higher proportion of recommended questions and correct details from the 3rd interview onward compared to the hypothesis-building and control groups. The difference between the number of correct conclusions was not significant. hypothesis-testing alone exacerbated the use of non-recommended questions over time. The results show that hypothesis-testing may impact question types used negatively but not when combined with feedback. The potential reasons for hypothesis-testing alone not being effective and the differences between the present and previous studies were discussed.
Lead (Pb) is one of the most relevant heavy metals contaminants which cause oxidative stress and threaten human health. The lung is one of the organs most severely damaged by Pb. In this study, we ...investigated the protective effect of grape seed procyanidin extract (GSPE) on Pb-induced lung injury in rats. We found that GSPE alleviated Pb-induced lung injury by relieving oxidative stress, reducing release of inflammatory factors, and inhibiting apoptosis. Furthermore, GSPE enhanced the antioxidant defense systems by activating the nuclear factor-erythroid-2-related factor (Nrf2) signaling pathway to promote downstream expression of heme oxygenase 1 and NAD(P)H quinone oxidoreductase 1. The subsequent ubiquitin-binding protein p62 (sequestosome 1), a downstream target of Nrf2, formed a positive feedback loop with Nrf2 during oxidative stress responses. GSPE treatment resulted in activation of adenosine monophosphate-activated protein kinase (AMPK), which was highly involved in Nrf2 activation. Overall, our findings demonstrate that theprotective effect of GSPE on Pb-induced lung injury arises from activation of the AMPK/Nrf2/p62 signaling pathway, thus providing a new approach for treatment of Pb intoxication.
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•Grape seed procyanidin extract inhibits lead-induced oxidative stress by activating AMPK/Nrf2/p62.•Grape seed procyanidin extract treatment attenuates inflammation and apoptosis induced by lead.•Grape seed procyanidin extract reduces the accumulation of lead in rat lungs.
Deltamethrin (DLM) is widely used in agriculture and the prevention of human insect-borne diseases. However, the molecular mechanism of DLM induced liver injury remains unclear to date. This study ...investigated the potential molecular mechanism that DLM induced liver fibrosis in quails. Japanese quails received resveratrol (500 mg/kg) daily with or without DLM (45 mg/kg) exposure for 12 weeks. Histopathology, transmission electron microscopy, biochemical indexes, TUNEL, quantitative real-time PCR, and western blot analysis were performed. DLM exposure induced hepatic steatosis, oxidative stress, inflammation, and apoptosis. Most importantly, the Nrf2/TGF-β1/Smad3 signaling pathway played an important role on DLM-induced liver fibrosis in quails. Interestingly, the addition of resveratrol, an Nrf2 activator, alleviates oxidative stress and inflammation response by activating Nrf2, thereby inhibits the liver fibrosis induced by DLM in quails. Collectively, these findings demonstrate that chronic exposure to DLM induces oxidative stress via the Nrf2 expression inhibition and apoptosis, and then results in liver fibrosis in quails by the activation of NF-κB/TNF-α and TGF-β1/Smad3 signaling pathway.
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•Chronic exposure to deltamethrin (DLM) induces liver fibrosis in quails.•Hepatic steatosis and oxidative stress are the key of DLM-induced liver fibrosis.•Resveratrol alleviates DLM-induced oxidative stress by activating Nrf2.•DLM induced the liver fibrosis via regulation of the Nrf2/TGF-β1/Smad3 pathway.
The incorporation of asymmetric Y junctions into thermoresponsive polymers allows access to hierarchical self-assembly, and self-assembly of cyclic polymers can further amplify the topology effect. ...At present, systematic insights into the influence of Y junctions on physicochemical properties remain at the early stage. A diversity of linear and cyclic polyacrylamide copolymers with substituent-variable Y junctions are designed to reveal the effects of topology, chain length, composition, concentration, and temperature. With the increasing size of substituents, copolymer aqueous solutions gradually shift from dual upper and lower critical solution temperatures (UCST/LCST) to a single LCST until the lack of phase transition. The LCST can be elevated by introduction of a cyclic architecture, longer polymer chain, and smaller substituent. Owing to the changes in degree of hydration of subunits, heat can induce sphere–vesicle–nanosheet–nanoribbon–sphere (linear copolymer) and sphere–nanosheet–nanoribbon (cyclic copolymer) transitions. In addition, the cyclization effect is also reflected in cooperative hydration of distinct subunits upon heating, higher ceiling temperatures to form stable lamellae, and more pronounced hysteresis of the turbidity curve upon cooling. This research using Y junction bearing thermoresponsive copolymers may provide a promising platform to achieve on-demand phase transitions and nanostructures.
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