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The prevalence of chronic kidney disease (CKD) is highly increasing. Renal fibrosis is a common pathological feature in various CKD. Previous studies showed tubular cell senescence is highly involved in the pathogenesis of renal fibrosis. However, the inducers of tubular senescence and the underlying mechanisms have not been fully investigated. C-X-C motif chemokine receptor 4 (CXCR4), a G-protein-coupled seven-span transmembrane receptor, increases renal fibrosis and plays an important role in tubular cell injury. Whereas, whether CXCR4 could induce tubular cell senescence and the detailed mechanisms have not studied yet. In this study, we adopted adriamycin nephropathy and 5/6 nephrectomy models, and cultured tubular cell line. Overexpression or knockdown of CXCR4 was obtained by injection of related plasmids. We identified CXCR4 increased in injury tubular cells. CXCR4 was expressed predominantly in renal tubular epithelial cells and co-localized with adipose differentiation-related protein (ADRP) as well as the senescence-related protein P16INK4A . Furthermore, we found overexpression of CXCR4 greatly induced the activation of ß-catenin, while knockdown of CXCR4 inhibited it. We also found that CXCR4 inhibited fatty acid oxidation and triggered lipid deposition in tubular cells. To inhibit ß-catenin by ICG-001, an inhibitor of ß-catenin, could significantly block CXCR4-suppressed fatty acid oxidation. Taken together, our results indicate that CXCR4 is a key mediator in tubular cell senescence and renal fibrosis. CXCR4 promotes tubular cell senescence and renal fibrosis by inducing ß-catenin and inhibiting fatty acid metabolism. Our findings provide a new theory for tubular cell injury in renal fibrosis.
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Rim , Receptores CXCR4 , Insuficiência Renal Crônica , beta Catenina , beta Catenina/metabolismo , Senescência Celular , Células Epiteliais/metabolismo , Ácidos Graxos/metabolismo , Fibrose , Rim/patologia , Insuficiência Renal Crônica/patologia , Receptores CXCR4/genética , Receptores CXCR4/metabolismo , Animais , CamundongosRESUMO
The liver, the largest organ in the human body, plays a multifaceted role in digestion, coagulation, synthesis, metabolism, detoxification, and immune defense. Changes in liver function often coincide with disruptions in both the central and peripheral nervous systems. The intricate interplay between the nervous and immune systems is vital for maintaining tissue balance and combating diseases. Signaling molecules and pathways, including cytokines, inflammatory mediators, neuropeptides, neurotransmitters, chemoreceptors, and neural pathways, facilitate this complex communication. They establish feedback loops among diverse immune cell populations and the central, peripheral, sympathetic, parasympathetic, and enteric nervous systems within the liver. In this concise review, we provide an overview of the structural and compositional aspects of the hepatic neural and immune systems. We further explore the molecular mechanisms and pathways that govern neuroimmune communication, highlighting their significance in liver pathology. Finally, we summarize the current clinical implications of therapeutic approaches targeting neuroimmune interactions and present prospects for future research in this area.
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Hepatopatias , Fígado , Neuroimunomodulação , Humanos , Animais , Neuroimunomodulação/fisiologia , Fígado/imunologia , Fígado/patologia , Fígado/metabolismo , Hepatopatias/imunologiaRESUMO
BACKGROUND: Ulcerative colitisis (UC) classified as a form of inflammatory bowel diseases (IBD) characterized by chronic, nonspecific, and recurrent symptoms with a poor prognosis. Common clinical manifestations of UC include diarrhea, fecal bleeding, and abdominal pain. Even though anti-inflammatory drugs can help alleviate symptoms of IBD, their long-term use is limited due to potential side effects. Therefore, alternative approaches for the treatment and prevention of inflammation in UC are crucial. METHODS: This study investigated the synergistic mechanism of Lactobacillus plantarum SC-5 (SC-5) and tyrosol (TY) combination (TS) in murine colitis, specifically exploring their regulatory activity on the dextran sulfate sodium (DSS)-induced inflammatory pathways (NF-κB and MAPK) and key molecular targets (tight junction protein). The effectiveness of 1 week of treatment with SC-5, TY, or TS was evaluated in a DSS-induced colitis mice model by assessing colitis morbidity and colonic mucosal injury (n = 9). To validate these findings, fecal microbiota transplantation (FMT) was performed by inoculating DSS-treated mice with the microbiota of TS-administered mice (n = 9). RESULTS: The results demonstrated that all three treatments effectively reduced colitis morbidity and protected against DSS-induced UC. The combination treatment, TS, exhibited inhibitory effects on the DSS-induced activation of mitogen-activated protein kinase (MAPK) and negatively regulated NF-κB. Furthermore, TS maintained the integrity of the tight junction (TJ) structure by regulating the expression of zona-occludin-1 (ZO-1), Occludin, and Claudin-3 (p < 0.05). Analysis of the intestinal microbiota revealed significant differences, including a decrease in Proteus and an increase in Lactobacillus, Bifidobacterium, and Akkermansia, which supported the protective effect of TS (p < 0.05). An increase in the number of Aspergillus bacteria can cause inflammation in the intestines and lead to the formation of ulcers. Bifidobacterium and Lactobacillus can regulate the micro-ecological balance of the intestinal tract, replenish normal physiological bacteria and inhibit harmful intestinal bacteria, which can alleviate the symptoms of UC. The relative abundance of Akkermansia has been shown to be negatively associated with IBD. The FMT group exhibited alleviated colitis, excellent anti-inflammatory effects, improved colonic barrier integrity, and enrichment of bacteria such as Akkermansia (p < 0.05). These results further supported the gut microbiota-dependent mechanism of TS in ameliorating colonic inflammation. CONCLUSION: In conclusion, the TS demonstrated a remission of colitis and amelioration of colonic inflammation in a gut microbiota-dependent manner. The findings suggest that TS could be a potential natural medicine for the protection of UC health. The above results suggest that TS can be used as a potential therapeutic agent for the clinical regulation of UC.
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Colite Ulcerativa , Colite , Doenças Inflamatórias Intestinais , Lactobacillus plantarum , Álcool Feniletílico/análogos & derivados , Simbióticos , Animais , Camundongos , Colite Ulcerativa/tratamento farmacológico , Azeite de Oliva , NF-kappa B , Ocludina , Modelos Animais de Doenças , Colite/induzido quimicamente , Inflamação/complicações , Inflamação/tratamento farmacológico , Colo , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Doenças Inflamatórias Intestinais/tratamento farmacológico , Sulfato de Dextrana/efeitos adversos , Camundongos Endogâmicos C57BLRESUMO
Phase unwrapping is a crucial step in obtaining the final physical information in the field of optical metrology. Although good at dealing with phase with discontinuity and noise, most deep learning-based spatial phase unwrapping methods suffer from the complex model and unsatisfactory performance, partially due to simple noise type for training datasets and limited interpretability. This paper proposes a highly efficient and robust spatial phase unwrapping method based on an improved SegFormer network, SFNet. The SFNet structure uses a hierarchical encoder without positional encoding and a decoder based on a lightweight fully connected multilayer perceptron. The proposed method utilizes the self-attention mechanism of the Transformer to better capture the global relationship of phase changes and reduce errors in the phase unwrapping process. It has a lower parameter count, speeding up the phase unwrapping. The network is trained on a simulated dataset containing various types of noise and phase discontinuity. This paper compares the proposed method with several state-of-the-art deep learning-based and traditional methods in terms of important evaluation indices, such as RMSE and PFS, highlighting its structural stability, robustness to noise, and generalization.
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The imaging spectrometer's high performance in practical applications may be compromised by environmental factors, particularly temperature variations, posing a challenge to its stability. Temperature fluctuations can induce spectral shift, directly impacting the accuracy of spectral measurements, subsequently influencing the precision of radiometric measurements. To address this issue, this study investigates a dual-channel UV imaging spectrometer. This instrument boasts a wavelength calibration accuracy of 0.01â nm. This paper conducts an in-depth analysis of the various mechanisms through which temperature changes influence the spectral line offset in the imaging spectrometer, integrating actual orbital temperature data to discuss the instrument's temperature load settings. The impact of temperature on spectral shift is examined using finite element analysis and optical design software. Estimations of spectral shift were made based on temperature variations. Simulation results indicated that the maximum deviation of spectral shift is estimated at 0.018â nm under a temperature condition of 16 ± 1°C. Under a more controlled orbital temperature condition (16 ± 0.3°C), the maximum deviation of spectral shift decreased to 0.01â nm. Experimental data revealed that at 16 ± 1°C, the maximum deviation of spectral shift did not exceed 0.01â nm. This effectively corroborates our theoretical analysis. The relationship between temperature and spectral shift offers a crucial theoretical foundation for calibrating spectral measurements and managing the thermal conditions of the instrument.
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Our study was designed to investigate the original spectrum of feline respiratory tract infection and to provide a scientific basis for the clinical diagnosis and treatment of feline respiratory infections and for precise prevention and control measures. A total of 400 cats with upper respiratory tract infections from animal hospitals in 12 provinces in China were examined from November 2022 to October 2023 to investigate the epidemiology of feline calicivirus (FCV), feline herpes virus type 1 (FHV-1), influenza A virus (IAV), Mycoplasma felis, Chlamydia felis, and Bordetella bronchiseptica through loop-mediated isothermal amplification (LAMP) with microfluidic chip detection. The results showed that 396 of the 400 samples tested were positive for at least one of these pathogens, with an overall detection rate of 99.00%. The detection rates were as follows: FCV, 36.00% (144/400); M. felis, 34.00% (136/400); FHV-1, 21.50% (86/400); C. felis, 15.75% (63/400); B. b, 13.00% (52/400); IAV, 4.50% (18/400). There were no statistically significant differences in the detection rates of respiratory pathogens between different sexes, ages, seasons, breeds, or regions (P > 0.05). There were 88 mixed infections, giving a total mixed infection rate of 22.00% (88/400). It is worth noting that the detection rate of FCV at different ages and of FHV-1 in different sexes showed significant differences (P < 0.05). The highest rate of FCV infection was found in animals that were 1 to 2 years old, and the rate of FHV-1 infection in male cats was higher than that in female cats. The results showed that the spectrum of feline respiratory pathogens is complex, with diverse epidemiological characteristics and mixed infections, and some differences among different respiratory pathogens were found with regard to the sex, age, and breed of the cat. Studies should be continued to provide a scientific basis for precise prevention and control of feline respiratory diseases.
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Doenças do Gato , Técnicas de Amplificação de Ácido Nucleico , Infecções Respiratórias , Animais , Gatos , Infecções Respiratórias/veterinária , Infecções Respiratórias/virologia , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/microbiologia , Infecções Respiratórias/diagnóstico , Doenças do Gato/virologia , Doenças do Gato/epidemiologia , Doenças do Gato/microbiologia , Feminino , Masculino , China/epidemiologia , Técnicas de Amplificação de Ácido Nucleico/métodos , Calicivirus Felino/isolamento & purificação , Calicivirus Felino/genética , Vírus da Influenza A/isolamento & purificação , Vírus da Influenza A/genética , Vírus da Influenza A/classificação , Chlamydia/genética , Chlamydia/isolamento & purificação , Chlamydia/classificação , Bordetella bronchiseptica/isolamento & purificação , Bordetella bronchiseptica/genética , Mycoplasma/isolamento & purificação , Mycoplasma/genética , Mycoplasma/classificação , Técnicas de Diagnóstico Molecular/métodos , Varicellovirus/genética , Varicellovirus/isolamento & purificação , Varicellovirus/classificação , Sistema Respiratório/virologia , Sistema Respiratório/microbiologiaRESUMO
Gangliosides play an imperative role in cell signaling, neuronal recovery, apoptosis, and other physiological processes. For example, GM3 can regulate hypothalamic leptin resistance and control energy homeostasis, GD3 can mediate cell proliferation and differentiation and induce apoptosis, and GQ1b can stimulate neurogenesis. Therefore, the present study sought to establish and optimize the targeted analysis method for ganglioside subclasses and their molecular species using hydrophilic interaction liquid chromatography-triple quadrupole-MS/MS (HILIC-QQQ-MS/MS). Additionally, the fragmentation pattern of different ganglioside subclasses and their retention time patterns were analyzed, providing more accurate qualitative results. The limit of quantitation (LOQ) was as low as 10-4 ng. Moreover, the molecular species of gangliosides in the liver, cortex, and hypothalamus of C57BL/6 mice were analyzed using the established method. A total of 23 ganglioside subclasses with 164 molecular species, including 40 O-acetylated ganglioside molecular species and 28 NeuGc ganglioside molecular species, were identified using the semi-quantitative analysis method of an external standard curve corrected by an internal standard. In addition to NeuGc gangliosides, the contents of ganglioside subclasses were more abundant in the mouse brain than those in the mouse liver; especially, the contents of unsaturated gangliosides in the hypothalamus were much higher than those in the liver. Among them, O-acetylated gangliosides were detected only in the cortex and hypothalamus at a concentration of up to 100 µg/mg protein (40 molecular species). Overall, the proposed method expanded the detectable number of ganglioside subclasses and molecular species in biological samples and provided more opportunities for further study of the biological functions of gangliosides.
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PURPOSE: Ulcerative colitis (UC) is a serious health problem with increasing morbidity and prevalence worldwide. The pathogenesis of UC is complex, currently believed to be influenced by genetic factors, dysregulation of the host immune system, imbalance in the intestinal microbiota, and environmental factors. Currently, UC is typically managed using aminosalicylates, immunosuppressants, and biologics as adjunctive therapies, with the risk of relapse and development of drug resistance upon discontinuation. Therefore, further research into the pathogenesis of UC and exploration of potential treatment strategies are necessary to improve the quality of life for affected patients. According to previous studies, Lactobacillus paracasei Jlus66 (Jlus66) reduced inflammation and may help prevent or treat UC. METHODS: We used dextran sulfate sodium (DSS) to induce a mouse model of UC to assess the effect of Jlus66 on the progression of colitis. During the experiment, we monitored mouse body weight, food and water consumption, as well as rectal bleeding. Hematoxylin-eosin staining was performed to assess intestinal pathological damage. Protein imprinting and immunohistochemical methods were used to evaluate the protein levels of nuclear factor-kappa B (NF-κB), mitogen-activated protein kinase (MAPK), and tight junction (TJ) proteins in intestinal tissues. Fecal microbiota was analyzed based on partial 16S rRNA gene sequencing. RESULTS: Jlus66 supplementation reduced the degree of colon tissue damage, such as colon shortening, fecal occult blood, colon epithelial damage, and weight loss. Supplementation with Jlus66 reduced DSS-induced upregulation of cytokine levels such as TNF-α, IL-1ß, and IL-6 (p < 0.05). The NF-κB pathway and MAPK pathway were inhibited, and the expression of TJ proteins (ZO-1, Occludin, and Claudin-3) was upregulated. 16S rRNA sequencing of mouse cecal contents showed that Jlus66 effectively regulated the structure of the intestinal biota. CONCLUSION: In conclusion, these data indicate that Jlus66 can alter the intestinal biota and slow the progression of UC, providing new insights into potential therapeutic strategies for UC.
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Renal tubular epithelial cell senescence plays a critical role in promoting and accelerating kidney aging and age-related renal fibrosis. Senescent cells not only lose their self-repair ability, but also can transform into senescence-associated secretory phenotype (SASP) to trigger inflammation and fibrogenesis. Recent studies show that mitochondrial dysfunction is critical for renal tubular cell senescence and kidney aging, and calcium overload and abnormal calcium-dependent kinase activities are involved in mitochondrial dysfunction-associated senescence. In this study we investigated the role of mitochondrial calcium overload and mitochondrial calcium uniporter (MCU) in kidney aging. By comparing the kidney of 2- and 24-month-old mice, we found calcium overload in renal tubular cells of aged kidney, accompanied by significantly elevated expression of MCU. In human proximal renal tubular cell line HK-2, pretreatment with MCU agonist spermine (10 µM) significantly increased mitochondrial calcium accumulation, and induced the production of reactive oxygen species (ROS), leading to renal tubular cell senescence and age-related kidney fibrosis. On the contrary, pretreatment with MCU antagonist RU360 (10 µM) or calcium chelator BAPTA-AM (10 µM) diminished D-gal-induced ROS generation, restored mitochondrial homeostasis, retarded cell senescence, and protected against kidney aging in HK-2 cells. In a D-gal-induced accelerated aging mice model, administration of BAPTA (100 µg/kg. i.p.) every other day for 8 weeks significantly alleviated renal tubuarl cell senescence and fibrosis. We conclude that MCU plays a key role in promoting renal tubular cell senescence and kidney aging. Targeting inhibition on MCU provides a new insight into the therapeutic strategy against kidney aging.
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Timely and accurate diagnosis of Schistosoma infection is important to adopt effective strategies for schistosomiasis control. Previously, we demonstrated that Schistosoma japonicum can secret extracellular vesicles and their cargos may serve as a novel type of biomarkers for diagnosing schistosomiasis. Here, we developed a Gaussia luciferase immunoprecipitation assay combined with S. japonicum extracellular vesicle (SjEV) protein to evaluate its potential for diagnosing schistosomiasis. A saposin-like protein (SjSLP) identified from SjEVs was fused to the Gaussia luciferase as the diagnostic antigen. The developed method showed good capability for detecting S. japonicum infection in mice and human patients. We also observed that the method could detect Schistosoma infection in mice as early as 7 days of post-infection, which showed better sensitivity than that of indirect ELISA method. Overall, the developed method showed a good potential for detecting Schistosoma infection particularly for early stage, which may provide an alternative strategy for identify Schistosoma infection for disease control.
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Imunoprecipitação , Luciferases , Schistosoma japonicum , Esquistossomose Japônica , Animais , Esquistossomose Japônica/diagnóstico , Esquistossomose Japônica/parasitologia , Schistosoma japonicum/enzimologia , Schistosoma japonicum/imunologia , Camundongos , Humanos , Imunoprecipitação/métodos , Luciferases/genética , Feminino , Sensibilidade e Especificidade , Camundongos Endogâmicos BALB C , Ensaio de Imunoadsorção Enzimática/métodos , Vesículas Extracelulares , Antígenos de Helmintos/análise , Antígenos de Helmintos/imunologia , MasculinoRESUMO
BACKGROUND: Cellular senescence, macrophages infiltration, and vascular smooth muscle cells (VSMCs) osteogenic transdifferentiation participate in the pathophysiology of vascular calcification in chronic kidney disease (CKD). Senescent macrophages are involved in the regulation of inflammation in pathological diseases. In addition, senescent cells spread senescence to neighboring cells via Interferon-induced transmembrane protein3 (IFITM3). However, the role of senescent macrophages and IFITM3 in VSMCs calcification remains unexplored. AIMS: To explore the hypothesis that senescent macrophages contribute to the calcification and senescence of VSMCs via IFITM3. METHODS: Here, the macrophage senescence model was established using Lipopolysaccharides (LPS). The VSMCs were subjected to supernatants from macrophages (MCFS) or LPS-induced macrophages (LPS-MCFS) in the presence or absence of calcifying media (CM). Senescence-associated ß-galactosidase (SA-ß-gal), Alizarin red (AR), immunofluorescent staining, and western blot were used to identify cell senescence and calcification. RESULTS: The expression of IFITM3 was significantly increased in LPS-induced macrophages and the supernatants. The VSMCs transdifferentiated into osteogenic phenotype, expressing higher osteogenic differentiation markers (RUNX2) and lower VSMCs constructive makers (SM22α) when cultured with senescent macrophages supernatants. Also, senescence markers (p16 and p21) in VSMCs were significantly increased by senescent macrophages supernatants treated. However, IFITM3 knockdown inhibited this process. CONCLUSIONS: Our study showed that LPS-induced senescence of macrophages accelerated the calcification of VSMCs via IFITM3. These data provide a new perspective linking VC and aging, which may provide clues for diagnosing and treating accelerated vascular aging in patients with CKD.
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Senescência Celular , Lipopolissacarídeos , Macrófagos , Proteínas de Membrana , Músculo Liso Vascular , Proteínas de Ligação a RNA , Calcificação Vascular , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patologia , Lipopolissacarídeos/farmacologia , Calcificação Vascular/patologia , Calcificação Vascular/metabolismo , Macrófagos/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Proteínas de Ligação a RNA/metabolismo , Humanos , Miócitos de Músculo Liso/metabolismo , Miócitos de Músculo Liso/patologia , Insuficiência Renal Crônica/metabolismo , Insuficiência Renal Crônica/patologia , Células Cultivadas , Animais , Osteogênese , Transdiferenciação CelularRESUMO
Broadband filtering and reconstruction-based spectral measurement represent a hot technical route for miniaturized spectral measurement; the measurement encoding scheme has a great effect on the spectral reconstruction fidelity. The existing spectral encoding schemes are usually complex and hard to implement; thus, the applications are severely limited. Considering this, here, a simple spectral encoding method based on a triangular matrix is designed. The condition number of the proposed spectral encoding system is estimated and demonstrated to be relatively low theoretically; then, verification experiments are carried out, and the results show that the proposed encoding can work well under precise or unprecise encoding and measurement conditions; therefore, the proposed scheme is demonstrated to be an effective trade-off of the spectral encoding efficiency and implementation cost.
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The numerical aperture of the spectrometer is crucial for weak signal detection. The transmission lens-based configuration has more optimization variations, and the grating can work approximately in the Littrow condition; thus, it is easier to acquire high numerical aperture (NA). However, designing a large aperture focusing lens remains challenging, and thus, ultra-high NA spectrometers are still difficult to acquire. In this paper, we propose a method of setting image plane tilt ahead directly when designing the large aperture focusing lens to simplify the high NA spectrometer design. By analyzing the accurate demands of the focusing lens, it can be concluded that a focusing lens with image plane tilt has much weaker demand for achromatism, and other monochromatic aberration can also be reduced, which is helpful to increase the NA. An NA0.5 fiber optic spectrometer design is given to demonstrate the proposed method. The design results show that the NA can achieve 0.5 using four lenses of two materials, and the MTF is higher than 0.5 when the spectral dispersion length is 12.5 mm and the pixel size is 25 µm, and thus, the spectral resolution can achieve 6.5 nm when the spectral sampling ratio is 2:1. The proposed method can provide reference for applications when appropriate materials are limited and high sensitivity is necessary.
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Hyperspectral detection of the change rate of organic matter content in agricultural remote sensing requires a high signal-to-noise ratio (SNR). However, due to the large number and efficiency limitation of the components, it is difficult to improve the SNR. This study uses high-efficiency convex grating with a diffraction efficiency exceeding 50% across the 360-850 nm range, a back-illuminated Complementary Metal Oxide Semiconductor (CMOS) detector with a 95% efficiency in peak wavelength, and silver-coated mirrors to develop an imaging spectrometer for detecting soil organic matter (SOM). The designed system meets the spectral resolution of 10 nm in the 360-850 nm range and achieves a swath of 100 km and a spatial resolution of 100 m at an orbital height of 648.2 km. This study also uses the basic structure of Offner with fewer components in the design and sets the mirrors of the Offner structure to have the same sphere, which can achieve the rapid adjustment of the co-standard. This study performs a theoretical analysis of the developed Offner imaging spectrometer based on the classical Rowland circular structure, with a 21.8 mm slit length; simulates its capacity for suppressing the +2nd-order diffraction stray light with the filter; and analyzes the imaging quality after meeting the tolerance requirements, which is combined with the surface shape characteristics of the high-efficiency grating. After this test, the grating has a diffraction efficiency above 50%, and the silver-coated mirrors have a reflection value above 95% on average. Finally, the laboratory tests show that the SNR over the waveband exceeds 300 and reaches 800 at 550 nm, which is higher than some current instruments in orbit for soil observation. The proposed imaging spectrometer has a spectral resolution of 10 nm, and its modulation transfer function (MTF) is greater than 0.23 at the Nyquist frequency, making it suitable for remote sensing observation of SOM change rate. The manufacture of such a high-efficiency broadband grating and the development of the proposed instrument with high energy transmission efficiency can provide a feasible technical solution for observing faint targets with a high SNR.
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Metal-modified catalysts have attracted extraordinary research attention in heterogeneous catalysis due to their enhanced geometric and electronic structures and outstanding catalytic performances. Silver (Ag) possesses necessary active sites for ethylene epoxidation, but the catalyst activity is usually sacrificed to obtain high selectivity towards ethylene oxide (EO). Herein, we report that using Al can help in tailoring the unoccupied 3d state of Ag on the MnO2 support through strong electronic metal-support interactions (EMSIs), overcoming the activity-selectivity trade-off for ethylene epoxidation and resulting in a very high ethylene conversion rate (~100 %) with 90 % selectivity for EO under mild conditions (170 °C and atmospheric pressure). Structural characterization and theoretical calculations revealed that the EMSIs obtained by the Al modification tailor the unoccupied 3d state of Ag, modulating the adsorption of ethylene (C2H4) and oxygen (O2) and facilitating EO desorption, resulting in high C2H4 conversion. Meanwhile, the increased number of positively charge Ag+ lowers the energy barrier for C2H4(ads) oxidation to produce oxametallacycle (OMC), inducing the unexpectedly high EO selectivity. Such an extraordinary electronic promotion provides new promising pathways for designing advanced metal catalysts with high activity and selectivity in selective oxidation reactions.
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Asthma is a chronic airway inflammatory disease whose global incidence increases annually. The role of innate lymphoid cells (ILCs) is a crucial aspect of asthma research with respect to different endotypes of asthma. Based on its pathological and inflammatory features, asthma is divided into type 2 high and type 2 low endotypes. Type-2 high asthma is distinguished by the activation of type 2 immune cells, including T helper 2 (Th2) cells and ILC2s; the production of cytokines interleukin (IL)-4, IL-5 and IL-13; eosinophilic aggregation; and bronchial hyper-responsiveness. Type-2 low asthma represents a variety of endotypes other than type 2 high endotype such as the IL-1ß/ILC3/neutrophil endotype and a paucigranulocytic asthma, which may be insensitive to corticosteroid treatment and/or associated with obesity. The complexity of asthma is due to the involvement of multiple cell types, including tissue-resident ILCs and other innate immune cells including bronchial epithelial cells, dendritic cells, macrophages and eosinophils, which provide immediate defence against viruses, pathogens and allergens. On this basis, innate immune cells and adaptive immune cells combine to induce the pathological condition of asthma. In addition, the plasticity of ILCs increases the heterogeneity of asthma. This review focuses on the phenotypes of tissue-resident ILCs and their roles in the different endotypes of asthma, as well as the mechanisms of tissue-resident ILCs and other immune cells. Based on the phenotypes, roles and mechanisms of immune cells, the therapeutic strategies for asthma are reviewed.
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Asma , Imunidade Inata , Humanos , Linfócitos/metabolismo , Citocinas/metabolismoRESUMO
The spontaneously formed passivation layer, the solid electrolyte interphase (SEI) between the electrode and electrolyte, is crucial to the performance and durability of Li ion batteries. However, the Li ion transport mechanism in the major inorganic components of the SEI (Li2CO3 and LiF) is still unclear. Particularly, whether introducing an amorphous environment is beneficial for improving the Li ion diffusivity is under debate. Here, we investigate the Li ion diffusion mechanism in amorphous LiF and Li2CO3 via machine-learning-potential-assisted molecular dynamics simulations. Our results show that the Li ion diffusivity in LiF at room temperature cannot be accurately captured by the Arrhenius extrapolation from the high temperature (>600 K) diffusivities (difference of â¼2 orders of magnitude). We reveal that the spontaneous formation of Li-F regular tetrahedrons at low temperatures (<500 K) leads to an extremely low Li ion diffusivity, suggesting that designing an amorphous bulk LiF-based SEI cannot help with the Li ion transport. We further show the critical role of Li2CO3 in suppressing the Li-F regular tetrahedron formation when these two components of SEIs are mixed. Overall, our work provides atomic insights into the impact of the local environment on Li ion diffusion in the major SEI components and suggests that suppressing the formation of large-sized bulk-phase LiF might be critical to improve battery performance.
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Developing efficient and simple catalysts to reveal the key scientific issues in the epoxidation of ethylene has been a long-standing goal for chemists, whereas a heterogenized molecular-like catalyst is desirable which combines the best aspects of homogeneous and heterogeneous catalysts. Single-atom catalysts can effectively mimic molecular catalysts on account of their well-defined atomic structures and coordination environments. Herein, we report a strategy for selective epoxidation of ethylene, which exploits a heterogeneous catalyst comprising iridium single atoms to interact with the reactant molecules that act analogously to ligands, resulting in molecular-like catalysis. This catalytic protocol features a near-unity selectivity (99%) to produce value-added ethylene oxide. We investigated the origin of the improvement of selectivity for ethylene oxide for this iridium single-atom catalyst and attributed the improvement to the π-coordination between the iridium metal center with a higher oxidation state and ethylene or molecular oxygen. The molecular oxygen adsorbed on the iridium single-atom site not only helps to strengthen the adsorption of ethylene molecule by iridium but also alters its electronic structure, allowing iridium to donate electrons into the double bond π* orbitals of ethylene. This catalytic strategy facilitates the formation of five-membered oxametallacycle intermediates, leading to the exceptionally high selectivity for ethylene oxide. Our model of single-atom catalysts featuring remarkable molecular-like catalysis can be utilized as an effective strategy for inhibiting the overoxidation of the desired product. Implementing the concepts of homogeneous catalysis into heterogeneous catalysis would provide new perspectives for the design of new advanced catalysts.
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A grating-based interferometric cavity produces coherent diffraction light field in a compact size, serving as a promising candidate for displacement measurement by taking advantage of both high integration and high accuracy. Phase-modulated diffraction gratings (PMDGs) make use of a combination of diffractive optical elements, allowing for the diminishment of zeroth-order reflected beams and thus improving the energy utilization coefficient and sensitivity of grating-based displacement measurements. However, conventional PMDGs with submicron-scale features usually require demanding micromachining processes, posing a significant challenge to manufacturability. Involving a four-region PMDG, this paper establishes a hybrid error model including etching error and coating error, thus providing a quantitative analysis of the relation between the errors and optical responses. The hybrid error model and the designated process-tolerant grating are experimentally verified by micromachining and grating-based displacement measurements using an 850â nm laser, confirming the validity and effectiveness. It is found the PMDG achieves an energy utilization coefficient (the ratio of the peak-to-peak value of the ±1st order beams to the 0th-order beam) improvement of nearly 500% and a four-fold reduction in 0th-order beam intensity compared with the traditional amplitude grating. More importantly, this PMDG maintains very tolerant process requirements, and the etching error and coating error can be up to 0.5â µm and 0.6â µm, respectively. This offers attractive alternatives to the fabrication of PMDGs and grating-based devices with wide process compatibility. This work first systematically investigates the influence of fabrication errors and identifies the interplay between the errors and the optical response for PMDGs. The hybrid error model allows further avenues for the fabrication of diffraction elements with practical limitations of micromachining fabrication.
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Immersion gratings have high dispersion efficiency and have important application value in miniaturized imaging spectrometers, but its serious dispersion nonlinearity causes difficulties in calibration and image processing, which limits its application range. To solve this, this paper presents a design method for a two-material linear dispersion immersion grating device design method, and a compact small F-number immersion grating spectrometer based on it. First the vector form dispersion equation of the two-material immersion grating is derived and the linear spectral dispersion immersion grating design process is given, then a compact small F-number uniform dispersion imaging spectrometer is given as a design example using the proposed method. The results show that when the operating band of the system is 1590-1675â nm, the spectral resolution is better than 0.25â nm, and F-number can achieve better than 2. Compared with traditional single-material immersion grating imaging spectrometer, the designed imaging spectrometer dispersion linearity is significantly improved. Finally, the influence of prism materials, structure parameters and grating parameters on dispersion nonlinearity is analyzed. Design and analysis results show that the proposed two-material immersion grating device has much better spectral dispersion nonlinearity correction ability, and its design method can provide reference to the compact spectrometer design based on immersion gratings.