Background Significant progress has been made in cell replacement therapy for neural retinal diseases using retinal cells differentiated from human pluripotent stem cells. Low tumorigenicity and the ...ability to mature to form synaptic junctions make precursor cells a promising donor source. Here, we attempted to improve the yield of photoreceptor precursor cells in three-dimensional retinal organoids from human embryonic stem cells (hESCs). Methods A CRX-tdTomato-tagged hESC line was generated to track retinal precursors in 3D retinal organoids. COCO, a multifunctional antagonist of the Wnt, TGF-beta, and BMP pathways, was employed to 3D organoid differentiation schemes for enhanced photoreceptor precursor cells. Organoid fluorescence intensity measurement was used to monitor retinalization tendency with the number of precursors further checked by flow cytometry. Signature gene expression during organoid differentiation were assessed by qPCR and immunocytochemistry after COCO supplementation. Results CRX-positive cells can be spatiotemporally tracked by tdTomato without affecting retinalization during retinal organoid differentiation. Fluorescence intensity of organoids, which turned out highly consistent with flow cytometry measurement, allowed us to determine the differentiation efficiency of precursors during organoid culturing directly. Using COCO as an auxiliary supplement, rather than alone, can yield an increased number of photoreceptor precursors in the early stage of organoid differentiation. Over a longer time-frame, photoreceptor precursors enhanced their fate of cones and decreased fate of rods after treatment with COCO. Conclusions Tracing with the CRX-reporter system showed that in retinal organoids derived from human pluripotent stem cells, COCO increased the differentiation efficiency of photoreceptor precursors and cones. Keywords: Retinal organoid, 3D, COCO, CRX, Photoreceptor precursor, Fluorescent labeling, Cone
A severe dust storm event originated from the Gobi Desert in Central and East
Asia during 2–7 May 2017. Based on Moderate Resolution Imaging
Spectroradiometer (MODIS) satellite products, hourly ...environmental monitoring
measurements from Chinese cities and East Asian meteorological observation
stations, and numerical simulations, we analysed the spatial and temporal
characteristics of this dust event as well as its associated impact on the
Asia-Pacific region. The maximum observed hourly PM10 (particulate
matter with an aerodynamic diameter ≤ 10 µm) concentration
was above 1000 µg m−3 in Beijing, Tianjin, Shijiazhuang,
Baoding, and Langfang and above 2000 µg m−3 in Erdos, Hohhot,
Baotou, and Alxa in northern China. This dust event affected over
8.35 million km2, or 87 % of the Chinese mainland, and significantly deteriorated air quality in 316 cities of
the 367 cities examined across China. The maximum surface wind speed during
the dust storm was 23–24 m s−1 in the Mongolian Gobi Desert and
20–22 m s−1 in central Inner Mongolia, indicating the potential
source regions of this dust event. Lidar-derived vertical dust profiles in
Beijing, Seoul, and Tokyo indicated dust aerosols were uplifted to an
altitude of 1.5–3.5 km, whereas simulations by the Weather Research and
Forecasting with Chemistry (WRF-Chem) model indicated 20.4 and 5.3 Tg of
aeolian dust being deposited respectively across continental Asia and the
North Pacific Ocean. According to forward trajectory analysis by the FLEXible
PARTicle dispersion (FLEXPART) model, the East Asian dust plume moved across
the North Pacific within a week. Dust concentrations decreased from the East
Asian continent across the Pacific Ocean from a magnitude of 103 to
10−5 µg m−3, while dust deposition intensity ranged from
104 to 10−1 mg m−2. This dust event was unusual due to its
impact on continental China, the Korean Peninsula, Japan, and the North
Pacific Ocean. Asian dust storms such as those observed in early May 2017 may
lead to wider climate forcing on a global scale.
With the development of proteomics and epigenetics, a large number of RNA‐binding proteins (RBPs) have been discovered in recent years, and the interaction between long non‐coding RNAs (lncRNAs) and ...RBPs has also received increasing attention. It is extremely important to conduct in‐depth research on the lncRNA‐RBP interaction network, especially in the context of its role in the occurrence and development of cancer. Increasing evidence has demonstrated that lncRNA‐RBP interactions play a vital role in cancer progression; therefore, targeting these interactions could provide new insights for cancer drug discovery. In this review, we discussed how lncRNAs can interact with RBPs to regulate their localization, modification, stability, and activity and discussed the effects of RBPs on the stability, transport, transcription, and localization of lncRNAs. Moreover, we explored the regulation and influence of these interactions on lncRNAs, RBPs, and downstream pathways that are related to cancer development, such as N6‐methyladenosine (m6A) modification of lncRNAs. In addition, we discussed how the lncRNA‐RBP interaction network regulates cancer cell phenotypes, such as proliferation, apoptosis, metastasis, drug resistance, immunity, tumor environment, and metabolism. Furthermore, we summarized the therapeutic strategies that target the lncRNA‐RBP interaction network. Although these treatments are still in the experimental stage and various theories and processes are still being studied, we believe that these strategies may provide new ideas for cancer treatment.
Understanding strong metal‐support interactions is crucially important for developing atom‐efficient transition metal heterogeneous catalysts. Herein, we performed a density functional theory study ...of highly dispersed Pt on CeO2(110). Various surface models are compared in terms of thermodynamic stability, electronic properties and energy diagrams for CO oxidation. Pt prefers square‐planar oxygen coordination in all models with a +2 state. The structures with a single Pt atom exhibit a low CO oxidation activity. A higher activity is predicted by replacement of a surface Ce by two Pt atoms. The high activity of this highly stable structure stems from the coordinative unsaturation of one of the Pt atoms and the presence of a neighboring two‐fold O atom. The CO oxidation occurs via a Mars‐van Krevelen mechanism. A compared to single‐atom catalysts based on Pt in interaction with CeO2(111) emphasizes the strong dependence of catalytic activity on the ceria surface termination.
Single‐atom catalysis: A high activity of low‐temperature CO oxidation is predicted by replacement of a surface Ce of CeO2(110) by two Pt atoms, and the compared to single‐atom catalysts based on Pt in interaction with CeO2(111) emphasizes the strong dependence of catalytic activity on the ceria surface termination.
Abstract
Background
The coronavirus disease 2019 (COVID-19) pandemic has led to global research to predict those who are at greatest risk of developing severe disease and mortality. The aim of this ...meta-analysis was to determine the associations between obesity and the severity of and mortality due to COVID-19.
Methods
We searched the PubMed, EMBASE, Cochrane Library and Web of Science databases for studies evaluating the associations of obesity with COVID-19.
Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using random- or fixed-effects models. Meta-regression analyses were conducted to estimate regression coefficients.
Results
Forty-six studies involving 625,153 patients were included. Compared with nonobese patients, obese patients had a significantly increased risk of infection.
(OR 2.73, 95% CI 1.53–4.87;
I
2
= 96.8%), hospitalization (OR 1.72, 95% CI 1.55–1.92;
I
2
= 47.4%), clinically severe disease (OR 3.81, 95% CI 1.97–7.35;
I
2
= 57.4%), mechanical ventilation (OR 1.66, 95% CI 1.42–1.94;
I
2
= 41.3%), intensive care unit (ICU) admission (OR 2.25, 95% CI 1.55–3.27;
I
2
= 71.5%), and mortality (OR 1.61, 95% CI 1.29–2.01;
I
2
= 83.1%).
Conclusion
Patients with obesity may have a greater risk of infection, hospitalization, clinically severe disease, mechanical ventilation, ICU admission, and mortality due to COVID-19. Therefore, it is important to increase awareness of these associations with obesity in COVID-19 patients.
The interest for food waste (FW) in the scientific community has been growing consistently in the most recent years. This is reflected by the number of publications (journal articles and proceedings ...papers) which can be accessed in the Web of Science (WoS) database. However, lacking of systematic, chronological and synthesizing studies indicating how this field has evolved over time. The main objective of this paper is to consolidate the state of the art of research on FW, based on a bibliometrics study of articles published over the past 18 years. The results are discussed under the following perspectives: chronological distribution, countries, institutions, source titles, subject categories, and author keywords. It is found that the FW research has increased rapidly over past 18 years, most notably in the last 8 years. In total, 2340 research articles were published in 801 journals and in 161 WoS subject categories. The top 7 productive countries were analyzed herein. The predominance of Chinese institutions in terms of article count and a predominance of industrialized countries' institutions in terms of citation score were compared. Finally, based on keywords analysis, it comes to the conclusion that the clean energy, treatment and valorization, and management innovation have attracted extensive attention during the past decade.
•A systematic overview of scientific literature dealing with FW is provided by a bibliometric analysis.•The analysis of publication output, distribution of countries, institutions, and subject category are carried out.•The analysis of author keywords helps in drawing the research trends in a special perspective.•Researches on clean energy, LCA, and sustainability tend to be a new research focus in the area of FW.
•The removal ratio of phosphate onto Zn–Al LDH was higher than Mg–Al LDH and reached 95% respectively.•Mg–Al and Zn–Al LDHs exhibited rapid adsorption rates of phosphate and could reach equilibrium ...at 40min.•Phosphate species are adsorbed by LDHs via electrostatic attraction, ligand exchange and ion exchange.
Phosphate removal is important for the natural water or wastewater treatment, and adsorption is an efficient treatment process. In this study, Mg–Al and Zn–Al layered double hydroxides (LDHs) were synthesized by co-precipitation method at a constant pH of 9–10. The prepared LDHs were characterized by X-ray diffraction (XRD) and BET surface area determination. The XRD patterns showed the characteristic basal reflections of hydrotalcite-like LDH materials. BET surface area of Zn–Al LDH was larger than that of Mg–Al LDH. Adsorption experiments were carried out as a function of LDHs dosage, contact time and initial pH of phosphate solution. The adsorption of phosphate reached equilibrium quickly at about 40min. The experimental data showed a good compliance with the pseudo-second-order kinetic model. The Freundlich and Langmuir models both described the adsorption isotherm data well (R2>0.98). Zeta potential and fourier transform infrared spectroscopy (FTIR) analyses were used to elucidate adsorption mechanisms. The results indicated that phosphate species were adsorbed via electrostatic attraction, ligand exchange and ion exchange. The removal ratio of phosphate onto Zn–Al LDH was higher than Mg–Al LDH and reached 95% respectively, suggesting that Mg–Al and Zn–Al LDHs were excellent adsorbents for phosphorus removal from aqueous solution.
Topological phases have recently witnessed rapid progress in non-Hermitian systems. Here we study a one-dimensional non-Hermitian Aubry-André-Harper (AAH) model with imaginary periodic or ...quasiperiodic modulations. We demonstrate that the non-Hermitian off-diagonal AAH models can host zero-energy modes at the edges. In contrast to the Hermitian case, the zero-energy mode can be localized only at one edge. Such a topological phase corresponds to the existence of a quarter winding number defined by eigenenergy in momentum space. We further find the coexistence of a zero-energy mode located only at one edge and topological nonzero-energy edge modes characterized by a generalized Bott index. In the incommensurate case, a topological non-Hermitian quasicrystal is predicted where all bulk states and two topological edge states are localized at one edge. Such topological edge modes are protected by the generalized Bott index. Finally, we propose an experimental scheme to realize these non-Hermitian models in electric circuits. Our findings add another direction for exploring topological properties in Aubry-André-Harper models.
An epoxycyclohexenone (ECH) moiety occurs in natural products of both bacteria and ascomycete and basidiomycete fungi. While the enzymes for ECH formation in bacteria and ascomycetes have been ...identified and characterized, it remained obscure how this structure is biosynthesized in basidiomycetes. In this study, we i) identified a genetic locus responsible for panepoxydone biosynthesis in the basidiomycete mushroom Panus rudis and ii) biochemically characterized PanH, the cytochrome P450 enzyme catalyzing epoxide formation in this pathway. Using a PanH‐producing yeast as a biocatalyst, we synthesized a small library of bioactive ECH compounds as a proof of concept. Furthermore, homology modeling, molecular dynamics simulation, and site directed mutation revealed the substrate specificity of PanH. Remarkably, PanH is unrelated to ECH‐forming enzymes in bacteria and ascomycetes, suggesting that mushrooms evolved this biosynthetic capacity convergently and independently of other organisms.
PanH, a cytochrome P450 monooxygenase, was identified and verified as the enzyme responsible for epoxycyclohexenone formation in panepoxydone biosynthesis in the basidiomycete mushroom Panus rudis. A PanH‐producing yeast as a biocatalyst enabled an enzymatic approach to synthesize a library of bioactive epoxycyclohexenone compounds.
Phosphors emitting visible and near-infrared persistent luminescence have been explored extensively owing to their unusual properties and commercial interest in their applications such as ...glow-in-the-dark paints, optical information storage, and in vivo bioimaging. However, no persistent phosphor that features emissions in the ultraviolet C range (200-280 nm) has been known to exist so far. Here, we demonstrate a strategy for creating a new generation of persistent phosphor that exhibits strong ultraviolet C emission with an initial power density over 10 milliwatts per square meter and an afterglow of more than 2 h. Experimental characterizations coupled with first-principles calculations have revealed that structural defects associated with oxygen introduction-induced anion vacancies in fluoride elpasolite can function as electron traps, which capture and store a large number of electrons triggered by X-ray irradiation. Notably, we show that the ultraviolet C afterglow intensity of the yielded phosphor is sufficiently strong for sterilization. Our discovery of this ultraviolet C afterglow opens up new avenues for research on persistent phosphors, and it offers new perspectives on their applications in terms of sterilization, disinfection, drug release, cancer treatment, anti-counterfeiting, and beyond.
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