An iron‐catalyzed hydrofluorination of unactivated alkenes has been developed. The use of a multidentate ligand and the fluorination reagent N‐fluorobenzenesulfonimide (NFSI) proved to be critical ...for this reaction, which afforded various fluorinated compounds in up to 94 % yield.
H(igh)–F(ive): The combination of a multidentate ligand, (EtO)3SiH, and N‐fluorobenzenesulfonimide (NFSI) proved critical in facilitating an iron‐catalyzed hydrofluorination of unactivated alkenes to provide a variety of substituted fluorinated compounds. The reaction was shown to proceed by a radical mechanism and to be suitable for the fluorination of various biologically active substrates.
•Firmness declined sharply during postharvest storage of A. squamosa.•Fruit softening of A. squamosa was accompanied by changed moisture distribution.•Cell wall polysaccharides of A. squamosa ...degraded during storage.•PG, PME and Cx were involved in fruit softening of A. squamosa.
To investigate cell-wall carbohydrate metabolism and fruit softening of postharvest Annona squamosa, several indicators including firmness, moisture distribution, cell-wall polysaccharides compositions, activities of enzymes related with fruit softening during storage were studied. Results indicated that firmness exhibited a significant decline from 1 d to 3 d. Free and semi-bound moisture in pericarp was removed gradually and moisture migrated from high to low freedom degree during storage. Molecular weight distribution and monosaccharide composition of cell-wall polysaccharides changed greatly during storage, especially the degradation of pectin polysaccharide. Besides, related enzymes including PG, PME and Cx were all involved in fruit softening of postharvest Annona squamosa. This would provide theoretical basis to help solve fruit quality decline of Annona squamosa during storage in further research.
This study provides a facile and effective method to modify thin film composite (TFC) hollow fiber nanofiltration (NF) membranes by grafting poly (amidoamine) dendrimer (PAMAM) on the interfacially ...polymerized layer of polyethersulfone (PES) membranes for heavy metal removal. The PAMAM grafting not only decreases the pore size of the composite membrane, but also provides the positively charged functional groups, such as tertiary amino groups (RH3N+ and R3HN+), on the membrane surface to improve the hydrophilicity and water permeability of the TFC membrane without compromising rejection. The resultant membrane possesses rejection over 99% against most tested heavy metals like Pb2+, Cu2+, Ni2+, Cd2+, Zn2+ and As5+, with an outstanding pure water permeability (PWP) greater than 3.6Lm−2h−1bar−1 at 10bar. The rejection of the membrane to As3+ is also impressive. It can reach 97% by changing the solution pH. Moreover, the membrane shows stable performance for at least 72h under continuous testing. This PAMAM grafted TFC membrane may have great potential for heavy metal removal and other water treatment applications.
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•PAMAM dendrimer is grafted on a thin film composite membrane.•The membrane is positively charged due to amino groups grafted on the surface.•The membrane has a good pure water permeability (>3.6Lm−2h−1bar−1).•The membrane has excellent rejection to Pb2+, Ni2+, Cd2+, As5+, etc. (R>99%).•At pH 11.0, the rejection to As3+ can reach more than 97%.
This article is dedicated to providing a detailed review concerning the SPH-based hydrodynamic simulations for ocean energy devices (OEDs). Attention is particularly focused on three topics that are ...tightly related to the concerning field, covering (1) SPH-based numerical fluid tanks, (2) multi-physics SPH techniques towards simulating OEDs, and finally (3) computational efficiency and capacity. In addition, the striking challenges of the SPH method with respect to simulating OEDs are elaborated, and the future prospects of the SPH method for the concerning topics are also provided.
Composite membranes with asymmetric traits have gained attention in liquid separation, featuring gradient chemical and physical attributes that align or oppose mass transfer direction. Chemically ...asymmetric configurations harness internal driving forces to heighten separation efficiency, rendering them an appealing option for heightened separation efficiency and fouling prevention. Concurrently, the internal hierarchical structure differences within composite membranes—such as fiber‐based structural adjustments and the gradient density of functional layers—yield the dual benefits of effective liquid repelling and heightened transport efficiency. Unlike conventional phase‐change methods, electrospinning technology possesses advantages in constructing and governing composite fibrous membrane materials with asymmetric chemistry and hierarchical structures, driven by its adaptable stacking methodologies. Notably, the inherent pore structure of electrospun nanofibrous membranes emerges as a proven solution for minimizing transport resistance. In recent times, interest has surged in electrospun nanofibrous membranes endowed with internal asymmetric properties. However, the spotlight has predominantly graced Janus membranes, spotlighting opposite wettability on different sides, leaving other facets of asymmetric membrane enhancement somewhat underexplored. This comprehensive work unveils recent strides in design, fabrication, facilitated transport mechanisms, and real‐world liquid separation applications, all under the aegis of electrospun nanofiber membranes, each endowed with distinct asymmetric properties.
Compared to traditional membrane fabrication that relies on phase change behavior, electrospinning technology demonstrates advantages in constructing and controlling composite fibrous membrane materials with asymmetric chemical properties and hierarchical structures. This work focuses on the latest advancements in the design, creation, underlying transport mechanisms, and liquid separation use cases associated with electrospun nanofiber membranes showcasing varied asymmetric attributes.
In this study, we established a chronic obstructive pulmonary disease (COPD) model by stimulating mice with cigarette smoke, and observed the effects of dendritic cells (DCs) overexpressing SOCS1 on ...Th17, Treg and other related cytokines in peripheral blood, bronchoalveolar lavage fluid and lung tissues of COPD mice.
After successfully transfecting DCs with overexpressing SOCS1 (DC-SOCS1), the mice were injected with DC-SOCS1 (1 × 10
), DC-SOCS1 (2 × 10
) and immature DCs (1 × 10
) via tail vein on days 1 and 7 of COPD fumigation modeling. After day 28 of modeling, the peripheral blood, BALF and lung tissue samples were extracted from the mice, and the changes of DCs, Th17 and Treg cells and related cytokines were detected by immunohistochemistry, immunofluorescence, HE staining, flow cytometry and ELISA.
The results showed that DC-SOCS1 was able to reduce the secretion of pro-inflammatory factors and increase the anti-inflammatory factors in the COPD mice, and the effect of high concentration (2 × 10
DC-SOCS1) was better than low concentration (1 × 10
DC-SOCS1). Moreover, the intervention effect was significant on day 1 compared with day 7. In the mice injected with DC-SOCS1, the expression of CD83, IL-4, Foxp3, and CCR6 was increased on day 1 than those on day 7, while IL-17 and IFN-γ was decreased.
Intervention of COPD mice with high concentrations of DCs-SOCS1 reduced pro-inflammatory factor secretion and attenuated the inflammatory response in COPD. Trial registration Not applicable.
Novel radar-wave absorption nanocomposites are developed by filling the nanoscaled ferrites of strontium ferroxide (SrFe12O19) and carbonyl iron (CIP) individually into the highly flexible liquid ...silicone rubber (LSR) considered as dielectric matrix. Nanofiller dispersivities in SrFe12O19/LSR and CIP/LSR nanocomposites are characterized by scanning electronic microscopy, and the mechanical properties, electric conductivity, and DC dielectric-breakdown strength are tested to evaluate electrical insulation performances. Radar-wave absorption performances of SrFe12O19/LSR and CIP/LSR nanocomposites are investigated by measuring electromagnetic response characteristics and radar-wave reflectivity, indicating the high radar-wave absorption is dominantly derived from magnetic losses. Compared with pure LSR, the SrFe12O19/LSR and CIP/LSR nanocomposites represent acceptable reductions in mechanical tensile and dielectric-breakdown strengths, while rendering a substantial nonlinearity of electric conductivity under high electric fields. SrFe12O19/LSR nanocomposites provide high radar-wave absorption in the frequency band of 11~18 GHz, achieving a minimum reflection loss of −33 dB at 11 GHz with an effective absorption bandwidth of 10 GHz. In comparison, CIP/LSR nanocomposites realize a minimum reflection loss of −22 dB at 7 GHz and a remarkably larger effective absorption bandwidth of 3.9 GHz in the lower frequency range of 2~8 GHz. Radar-wave transmissions through SrFe12O19/LSR and CIP/LSR nanocomposites in single- and double-layered structures are analyzed with CST electromagnetic-field simulation software to calculate radar reflectivity for various absorbing-layer thicknesses. Dual-layer absorbing structures are modeled by specifying SrFe12O19/LSR and CIP/LSR nanocomposites, respectively, as match and loss layers, which are predicted to acquire a significant improvement in radar-wave absorption when the thicknesses of match and loss layers approach 1.75 mm and 0.25 mm, respectively.
•Thorough analysis of phenology using 18 metrics and 8 subregions across QTP.•New findings concerning impacts of different temperature components on phenology.•Quantitative differentiation of ...different factors influencing phenology in space and time.
Using NDVI3g vegetation index, we defined 18 phenology metrics to investigate phenological change on the Tibetan Plateau (TP). Considering the heterogeneity of vegetation phenology, we divided TP into 8 vegetation clusters according to a 1:1000000 vegetation cluster map. For regions where phenology is highly sensitive to climate, we investigated the impact of climate variables, such as temperature, precipitation, and solar radiation on phenology using the partial least squares regression (PLS) method. Results indicated (1) that turning points of the starting date of the growing season (SOS) metrics were in 1997–2000, before which SOS metrics advanced 2–3d/10a. The ending date of the growing season (EOS) and the length of growing season metrics (LOS) turning points were 2005 and 2004–2007, respectively. Before the turning points, the EOS metrics had a delayed tendency of 1–2d/10a, and the LOS metrics also had a prolonging tendency of 1–2d/10a. After the turning points, the significant levels of SOS and EOS metrics’ tendency only reached 0.1, and LOS’s tendency was insignificant at the 0.1 level. (2) Alpine meadows and alpine shrub meadows changed most intensely on TP. Advanced SOS and delayed EOS were the main reasons of the alpine meadow LOS extension. Advance SOS mainly contributed to the alpine shrub meadow LOS extension. (3) We used meteorological variables, such as temperature, precipitation and solar radiation, to analyze the drastic change of the phenology of alpine meadows and alpine shrub meadows through the PLS method. Temperature was found to be the dominant meteorological variable impacting phenology. In those regions, the previous year autumn and early winter temperature had a positive effect on the SOS phenology. The high temperature in this period would postpone previous year EOS, indirectly delaying SOS in the current year. On the other hand, warming autumn and early winter may slow the fulfilment of chilling requirements and lead to later SOS, which would have a delayed effect on SOS. Except summer, the minimum temperature had a similar effect on vegetation phenology, as average and maximum temperature. Furthermore, the effect of precipitation on phenology fluctuated widely across different months. The previous year autumn and winter precipitation had a negative effect on the SOS phenology, and early spring precipitation had a positive effect. The main factor limiting vegetation development in August was precipitation, and during this month precipitation had a positive impact on the EOS phenology. The influence of solar radiation was mainly during summer and early fall. This study will contribute toward vegetation phenology model improvement.
Abstract
Atherosclerosis-associated cardiovascular disease is one of the main causes of death and disability among patients with diabetes mellitus. However, little is known about the impact of ...S-nitrosylation in diabetes-accelerated atherosclerosis. Here, we show increased levels of S-nitrosylation of guanine nucleotide-binding protein G(i) subunit alpha-2 (SNO-GNAI2) at Cysteine 66 in coronary artery samples from diabetic patients with atherosclerosis, consistently with results from mice. Mechanistically, SNO-GNAI2 acted by coupling with CXCR5 to dephosphorylate the Hippo pathway kinase LATS1, thereby leading to nuclear translocation of YAP and promoting an inflammatory response in endothelial cells. Furthermore, Cys-mutant GNAI2 refractory to S-nitrosylation abrogated GNAI2-CXCR5 coupling, alleviated atherosclerosis in diabetic mice, restored Hippo activity, and reduced endothelial inflammation. In addition, we showed that melatonin treatment restored endothelial function and protected against diabetes-accelerated atherosclerosis by preventing GNAI2 S-nitrosylation. In conclusion, SNO-GNAI2 drives diabetes-accelerated atherosclerosis by coupling with CXCR5 and activating YAP-dependent endothelial inflammation, and reducing SNO-GNAI2 is an efficient strategy for alleviating diabetes-accelerated atherosclerosis.
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