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1.
ACS Sens ; 2022 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-35549157

RESUMO

Piezoelectric cantilever resonator is one of the most promising platforms for real-time sensing of volatile organic compounds (VOCs). However, it has been a great challenge to eliminate the cross-sensitivity of various VOCs for these cantilever-based VOC sensors. Herein, a virtual sensor array (VSA) is proposed on the basis of a sensing layer of GO film deposited onto an AlN piezoelectric cantilever with five groups of top electrodes for identification of various VOCs. Different groups of top electrodes are applied to obtain high amplitudes of multiple resonance peaks for the cantilever, thus achieving low limits of detection (LODs) to VOCs. Frequency shifts of multiple resonant modes and changes of impedance values are taken as the responses of the proposed VSA to VOCs, and these multidimensional responses generate a unique fingerprint for each VOC. On the basis of machine learning algorithms, the proposed VSA can accurately identify different types of VOCs and mixtures with accuracies of 95.8 and 87.5%, respectively. Furthermore, the VSA has successfully been applied to identify the emissions from healthy plants and "plants with late blight" with an accuracy of 89%. The high levels of identifications show great potentials of the VSA for diagnosis of infectious plant diseases by detecting VOC biomarkers.

2.
BMC Plant Biol ; 22(1): 239, 2022 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-35550027

RESUMO

BACKGROUND: Ancient tea plantations with an age over 100 years still reserved at Mengku Town in Lincang Region of Yunan Province, China. However, the characteristic of soil chemicophysical properties and microbial ecosystem in the ancient tea plantations and their correlation with tea-leaves chemical components remained unclear. Tea-leaves chemical components including free amino acids, phenolic compounds and purine alkaloids collected from modern and ancient tea plantations in five geographic sites (i.e. Bingdao, Baqishan, Banuo, Dongguo and Jiulong) were determined by high performance liquid chromatography (HPLC), while their soil microbial community structure was analyzed by high-throughput sequencing, respectively. Additionally, soil microbial quantity and chemicophysical properties including pH, cation exchange capacity (CEC), soil organic matter (SOM), soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), total potassium (TK), alkali-hydrolyzable nitrogen (AN), available phosphorous (AP) and available potassium (AK) were determined in modern and ancient tea plantations. RESULTS: Tea-leaves chemical components, soil chemicophysical properties and microbial community structures including bacterial and fungal community abundance and diversity evaluated by Chao 1 and Shannon varied with geographic location and tea plantation type. Ancient tea plantations were observed to possess significantly (P < 0.05) higher free amino acids, gallic acid, caffeine and epigallocatechin (EGC) in tea-leaves, as well as soil fertility. The bacterial community structure kept stable, while fungal community abundance and diversity significantly (P < 0.05) increased in ancient tea plantation because of higher soil fertility and lower pH. The long-term plantation in natural cultivation way might significantly (P < 0.05) improve the abundances of Nitrospirota, Methylomirabilota, Ascomycota and Mortierellomycota phyla. CONCLUSIONS: Due to the natural cultivation way, the ancient tea plantations still maintained relatively higher soil fertility and soil microbial ecosystem, which contributed to the sustainable development of tea-leaves with higher quality.

3.
Artigo em Inglês | MEDLINE | ID: mdl-35575049

RESUMO

The lifespan of practical lithium (Li) metal batteries is severely hindered by the instability of Li metal anodes. Fluorinated solid electrolyte interphase (SEI) emerges as a promising strategy to improve the stability of Li metal anodes. The rational design of fluorinated molecules is pivotal to constructing fluorinated SEI. Herein, design principles of fluorinated molecules are proposed. Fluoroalkyl (-CF2CF2-) is selected as an enriched F reservoir and the defluorination of C-F bond is driven by leaving groups on ß-site. An activated fluoroalkyl molecule (AFA), 2,2,3,3-tetraflurobutane-1,4-diol dinitrate is unprecedentedly proposed to render fast and complete defluorination and generate uniform fluorinated SEI on Li metal anodes. In Li-sulfur (Li-S) batteries under practical conditions, the fluorinated SEI constructed by AFA undergoes 183 cycles, which is three times of the SEI formed by LiNO3. Furthermore, a Li-S pouch cell of 360 Wh kg-1 delivers 25 cycles with AFA. This work demonstrates rational molecular design principles of fluorinated molecules to construct fluorinated SEI for practical Li metal batteries.

4.
J Ethnopharmacol ; : 115335, 2022 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-35513215

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Gynostemma pentaphyllum has been used as traditional medicine for many diseases, including metabolic syndrome (Mets), aging, diabetes, neurodegenerative diseases in China and some East Asian and Southeast Asian countries. It was shown that G. pentaphyllum and gypenosides had anti-obesity and cholesterol-lowering effects too. However, its main active ingredients are still unclear. AIMS: The objective of this study was to compare the effects of gypenosides before and after heat-processing on high fat obese mice, and to analyze the function of G. pentaphyllum saponin via network pharmacology and molecular docking. METHODS: The leaves of G. pentaphyllum were heat processed at 120 °C for 3 h to obtain heat-processed G. pentaphyllum. Gypenosides (Gyp) and heat-processed gypenosides (HGyp) were prepared by resin HP-20 chromatography and analyzed using LC-MS from the extracts of G. pentaphyllum before and after heat-processing, respectively. Obesity model was made with high fat diet (HFD). Gyp and HGyp were administrated at 100 mg/kg for 12 weeks in HFD obese mice and the body weight, energy intake, and levels of total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL), high-density lipoprotein (HDL) were compared. HGyp was administrated at a dose of 50,100,200 mg/kg for 12 weeks in HFD obese mice and the perirenal adipose, epididymal adipose, abdominal adipose, shoulder brown adipose, inguinal adipose were measured. Moreover, the potential targets, hub genes and pathways of damulin A, damulin B, gypenoside L, gypenoside LI for treating Mets were screened out via network pharmacology. According to the results of network pharmacology, core targets of treating Mets were docking with damulin A, gypenoside L, damulin B, gypenoside LI via molecular docking. RESULTS: HGyp showed stronger effects on body weight loss and lipid-lowering in obese mice than Gyp. The contents of gypenoside L, gypenoside LI, danulin A and dumulin B of G. pentaphyllum were increased by heat-processing. HGyp significantly decreased the body weight, calorie intake, and levels of TC, TG, LDL, HDL on the obese mice. It up-regulated PPARα and PPARγ in the liver tissues. HGyp reduced significantly the size of adipocytes in inguinal, abdominal, epididymal adipose and increased the proportion of interscapular brown fat. Network pharmacology results showed that 21 potential targets and 12 related-pathways were screened out. HMGCR, ACE, LIPC, LIPG, PPARα PPARδ, PPARγ were the core targets of HGyp against lipid metabolism by molecular docking. The putative functional targets of HGyp may be modulated by AGE-RAGE, TNF, glycerolipid metabolism, lipid and atherosclerosis, cholesterol metabolism, PPAR, fat digestion and absorption, cell adhesion molecules signaling pathway. CONCLUSIONS: Gyp and HGyp are valuable for inhibition obesity, lipid-lowering, metabolic regulation. Especially, the effect of HGyp is better than that of Gyp.

5.
Nat Commun ; 13(1): 2432, 2022 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-35508545

RESUMO

Aromatic tertiary amines are one of the most important classes of organic compounds in organic chemistry and drug discovery. It is difficult to efficiently construct tertiary amines from primary amines via classical nucleophilic substitution due to consecutive overalkylation. In this paper, we have developed a radical tandem C-N coupling strategy to efficiently construct aromatic tertiary amines from commercially available carboxylic acids and nitroarenes. A variety of aromatic tertiary amines can be furnished in good yields (up to 98%) with excellent functional group compatibility under mild reaction conditions. The use of two different carboxylic acids also allows for the concise synthesis of nonsymmetric aromatic tertiary amines in satisfactory yields. Mechanistic studies suggest the intermediacy of the arylamine-(TPP)Fe(III) species and might provide a possible evidence for an SH2 (bimolecular homolytic substitution) pathway in the critical C-N bond formation step.


Assuntos
Aminas , Compostos Férricos , Aminas/química , Ácidos Carboxílicos/química , Catálise
6.
Mol Biol Rep ; 2022 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-35526251

RESUMO

BACKGROUND: Laryngeal carcinoma is one of the common malignant tumors of the head and neck. Multidrug resistance (MDR) remains a critical problem in the chemotherapy of patients with laryngeal cancer. This study aims to clarify the role and mechanisms of Notch1 signaling in MDR induced by hypoxia in laryngeal cancer cells. METHODS AND RESULTS: Laryngeal carcinoma cells were cultured under normoxia or hypoxia. Notch1 expression was inhibited by small interfering RNA (siRNA). The mRNA expression of Notch1, Hes1, Hey1, MDR1 and survivin was analyzed by real-time PCR. The protein expression of Notch1, the Notch1 intracellular domain (N1ICD), MDR1/P-gp and survivin was analyzed by Western blotting. Current research has shown that hypoxia can upregulate Notch1 expression and Notch1 signaling activity. Furthermore, suppression of Notch1 expression effectively downregulated Notch1 signaling activity and the expression of the MDR and survivin genes in laryngeal cancer cells under hypoxic conditions (P < 0.05). The Cell Counting Kit-8 (CCK-8) assay results confirmed that the sensitivity of hypoxic laryngeal cancer cells to a variety of drugs could be upregulated by suppressing Notch1 expression (P < 0.05). Additionally, flow cytometry (FCM) showed that suppression of Notch1 expression significantly increased drug-induced apoptosis and intracellular rhodamine 123 (Rh123) accumulation in hypoxic laryngeal carcinoma cells (P < 0.05). CONCLUSIONS: Notch1 signalling could be regarded as a pivotal regulator of hypoxia-induced MDR in laryngeal cancer cells through the regulation of survivin-mediated apoptosis resistance and MDR1/P-gp-mediated drug transport.

7.
Interdiscip Sci ; 2022 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-35415827

RESUMO

Atypical visual attention is a hallmark of autism spectrum disorder (ASD). Identifying the attention features accurately discerning between people with ASD and typically developing (TD) at the individual level remains a challenge. In this study, we developed a new systematic framework combining high accuracy deep learning classification, deep learning segmentation, image ablation and a direct measurement of classification ability to identify the discriminative features for autism identification. Our two-stream model achieved the state-of-the-art performance with a classification accuracy of 0.95. Using this framework, two new categories of features, Food & drink and Outdoor-objects, were identified as discriminative attention features, in addition to the previously reported features including Center-object and Human-faces, etc. Altered attention to the new categories helps to understand related atypical behaviors in ASD. Importantly, the area under curve (AUC) based on the combined top-9 features identified in this study was 0.92, allowing an accurate classification at the individual level. We also obtained a small but informative dataset of 12 images with an AUC of 0.86, suggesting a potentially efficient approach for the clinical diagnosis of ASD. Together, our deep learning framework based on VGG-16 provides a novel and powerful tool to recognize and understand abnormal visual attention in ASD, which will, in turn, facilitate the identification of biomarkers for ASD.

8.
Inorg Chem ; 61(18): 6829-6836, 2022 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-35473298

RESUMO

Metal-organic frameworks (MOFs), a new type of porous material, have shown many possible applications in gas storage and separation, biomedicine, catalysis, and so on. While most MOFs are synthesized through solvothermal synthesis where a large quantity of organic solvent is used, the green synthetic approach using a minimized amount of solvent is important to prevent irreversible environmental compacts. In this study, we successfully synthesized Zr-MOFs with SBUs (e.g., UiO-66 and MIL-140A) using a simple metal source and investigated the role of organic modulators in modulating the MOF structures during solid-state synthesis. Meanwhile, UiO-66 rich in defects synthesized via a solid-state conversion strategy shows good catalytic performance for the ring-opening of epoxides with alcohols. This work contributes to the understanding of the role of organic modulators in the solid-state synthesis of MOFs.

9.
Chem Commun (Camb) ; 58(39): 5873-5876, 2022 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-35470834

RESUMO

In this communication, we report a photocatalyzed amidation strategy from carboxylic acids and tertiary amines through C-N bond cleavage. A wide scope of structurally diverse carboxylic acids participate smoothly in the reaction, providing the desired tertiary amides with moderate-to-good yields (34 examples, up to 93% yield). This amidation strategy provides an alternative way to address the regioselectivity between nucleophilic functional groups, thus complementing the functional group compatibility of classical amidation protocols. Its synthetic robustness is also proved by the late-stage modification of several complex molecules and gram-scale applications.


Assuntos
Aminas , Ácidos Carboxílicos , Amidas/química , Aminas/química , Ácidos Carboxílicos/química , Catálise
10.
Adv Mater ; : e2110356, 2022 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-35439839

RESUMO

Wide-bandgap (∼1.8 eV) perovskite is an crucial component to pair with narrow-bandgap perovskite in low-cost monolithic all-perovskite tandem solar cells. However, the stability and efficiency of wide-bandgap perovskite solar cells are constrained by the light-induced halide segregation and by the large photovoltage deficit. Here we report a steric engineering to obtain high-quality and photostable wide-bandgap perovskites (∼1.8 eV) suitable for all-perovskite tandems. By alloying dimethylammonium and chloride into the mixed-cation mixed-halide perovskites, wide bandgaps are obtained with much lower bromide contents while the lattice strain and trap densities are simultaneously minimized. The wide-bandgap perovskite solar cells exhibit considerably improved performance and photostability, retaining >90% of their initial efficiencies after 1000 hours of operation at maximum power point. With the triple-cation/triple-halide wide-bandgap perovskites enabled by steric engineering, we further obtain a stabilized PCE of 26.0% in all-perovskite tandem solar cells. Our strategy provides an avenue to fabricate efficient and stable wide-bandgap subcells for multi-junction photovoltaic devices. This article is protected by copyright. All rights reserved.

11.
Bioconjug Chem ; 33(4): 654-665, 2022 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-35385661

RESUMO

Radiation therapy (RT) concurrent with chemotherapy improves local lung cancer control but may cause systemic toxicity. There is an unmet clinical need of treatments that can selectively sensitize cancer cells to RT. Herein, we explored a radiosensitizing strategy that combines doxorubicin (DOX)-encapsulated polyaspartamide nanoparticles and 5-aminolevulinic acid (5-ALA). The DOX-polyaspartamide nanoparticles were coupled with NTSmut, a ligand specific to neurotensin receptor type 1 (NTSR1), for lung cancer targeting. DOX was coupled to the polymer backbone through a pH-sensitive hydrazone linker, which allows for controlled release of the drug in an acidic tumor micromovement. Meanwhile, 5-ALA accumulates in the cancer cell's mitochondria, forming protoporphyrin (PpIX) that amplifies RT-induced oxidative stress. When tested in vitro in H1299 cells, DOX-encapsulated nanoparticles in conjugation with 5-ALA enhanced cancer cell killing owing to the complementary radiosensitizing effects of DOX and 5-ALA. In vivo studies confirmed that the combination improved tumor suppression relative to RT alone without causing toxicity to normal tissues. Overall, our study suggests an effective and selective radiosensitizing approach.


Assuntos
Neoplasias Pulmonares , Nanopartículas , Ácido Aminolevulínico , Linhagem Celular Tumoral , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Humanos , Concentração de Íons de Hidrogênio , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Polímeros
12.
Front Med (Lausanne) ; 9: 873684, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35463016

RESUMO

Objective: To compare opacity characteristics of US-860 UV and L-312 IOL, and report the phenomenon of glistenings in hydrophobic-hydrophilic acrylic IOLs. Setting: Qingdao Eye Hospital. Design: Experimental study. Methods: Four medical records (4 eyes) of patients with L-312 or US-860 UV IOL opacification reporting decreased or lost vision who underwent IOL explanation between 2019 and 2021 were reviewed. Explanted IOLs were analyzed by slit-lamp examination, confocal microscopy, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) at Qingdao Eye Hospital and Qingdao university of science and technology. Results: The 4 explanted IOLs were represented by 2 hydrophilic acrylic designs. The preoperative mean corrected distance visual acuity changed from 1.84 ± 1.09 logarithm of the minimum angle of resolution (log MAR) to 0.20 ± 0.03 log MAR postoperatively except case 3. The mean interval of the L-312 IOL was 56.67 ± 14.19 months (range 44 to 72 months), and the interval of the US-860 UV IOL was 27 months. Morphological findings were surface, subsurface calcifications of the US-860 UV IOL material, and the optical region of L-312 IOLs are teeming with a great number of vacuoles by light microscope, scanning electron microscope and Energy Dispersive X-ray Spectral. Conclusion: The cause of US-860 UV opacification was primary calcification, and vacuoles resulted in L-312 IOL opacification.

13.
Front Psychol ; 13: 792108, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35465482

RESUMO

Objective: To explore the relationship between adolescents' social mobility belief and their learning engagement, as well as the mediating effect of achievement goal orientation and the moderating effect of psychological capital. Method: A sample of 895 adolescents from Hunan, Jiangxi, Hainan, Henan, and Guangdong provinces were assessed using the social mobility belief questionnaire, the achievement goal orientation questionnaire, the adolescents' psychological capital questionnaire, and the adolescents' learning engagement questionnaire. Results: First, adolescents' social mobility belief was positively related to their learning engagement (r = 0.481, p < 0.01); Second, the two achievement goal orientations-mastery goal orientations and performance goal orientations-had mediating effects between social mobility belief and learning engagement (r = 0.603, p < 0.01; r = 0.367, p < 0.01); Third, the relationship between achievement goal orientation and learning engagement was regulated by psychological capital. Adolescents with high psychological capital had higher learning engagement (r = 0.684, p < 0.01). Conclusion: Adolescents' social mobility belief can directly affect their learning engagement, and it can also indirectly affect their learning engagement through achievement goal orientation moderated by their level of psychological capital. Our findings highlighted the importance of providing adolescents with guidance in setting up positive social values and definitions of success while stimulating their psychological capital as a part of the teaching process.

14.
Int Orthop ; 2022 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-35306569

RESUMO

PURPOSE: There is scant literature on the evaluation of dislocation after total hip arthroplasty (THA) in patients with ipsilateral valgus knee deformity. This study aimed to investigate the post-operative dislocation rate in patients with valgus knee deformity who underwent ipsilateral THA and identify whether ipsilateral valgus knee deformity increases the dislocation rate after THA. METHODS: We retrospectively reviewed patients with valgus knee deformity who underwent ipsilateral THA in our institution from January 2016 to December 2018. Each hip with ipsilateral valgus knee deformity was matched with a hip without valgus knee deformity according to sex, affected side, and date of surgery. The primary outcome was the dislocation rate after THA. Univariate analyses were initially used to compare data between the dislocation group and the non-dislocation group. Independent risk factors for dislocation were determined using multivariate logistic regression. RESULTS: There were 257 THAs with ipsilateral valgus knee deformity (valgus knee group) and 257 THAs without valgus knee deformity (control group). The valgus knee group showed a significantly higher dislocation rate than the control group (9.7% versus 1.6%, p < 0.001). Older age (p = 0.020) and malposition of the acetabular cup (p = 0.048) were independent risk factors of post-operative dislocation. CONCLUSION: Patients with valgus knee deformity have a higher risk of dislocation after ipsilateral THA. If ipsilateral THA and total knee arthroplasty must be performed successively, total knee arthroplasty may have an earlier priority than THA.

15.
World J Clin Cases ; 10(6): 1806-1814, 2022 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-35317147

RESUMO

BACKGROUND: Although transcatheter aortic valve implantation (TAVI) is a safe and effective treatment for aortic stenosis, it still carries some risks, such as valve leaks, stroke, and even death. The left ventricular global longitudinal strain (LVGLS) measurement may be useful for the prediction of adverse events during this operation. AIM: To explore the change of LVGLS during TAVI procedure and the relationship between LVGLS and perioperative adverse events. METHODS: In this study, 61 patients who had undergone percutaneous transfemoral TAVI were evaluated by transthoracic echocardiography. Before surgery, data on left ventricular ejection fraction (LVEF) and LVGLS were collected separately following balloon expansion and stent implantation. Difference in values of LVGLS and LVEF during preoperative balloon expansion (pre-ex), preoperative stent implantation (pre-im) and balloon expansion-stent implantation (ex-im) were also examined. Adverse events were defined as perioperative death, cardiac rupture, heart arrest, moderate or severe perivalvular leakage, significant mitral regurgitation during TAVI, perioperative moderate or severe mitral regurgitation, perioperative left ventricular outflow tract obstruction, reoperation, and acute heart failure. RESULTS: The occurrence of perioperative adverse events was associated with differences in pre-ex LVGLS, but not with difference in pre-ex LVEF. There were significant differences between pre-LVGLS and ex-LVGLS, and between pre-LVGLS and im-LVGLS (P = 0.037 and P = 0.020, respectively). However, differences in LVEF were not significant (P = 0.358, P = 0.254); however differences in pre-ex LVGLS were associated with pre-LVGLS (P = 0.045). Compared to LVEF, LVGLS is more sensitive as a measure of left heart function during TAVI and the perioperative period. Moreover, the differences in LVGLS were associated with the occurrence of perioperative adverse events, and changes in LVGLS were apparent in patients with undesirable LVGLS before the surgery. Furthermore, LVGLS is useful to predict changes in cardiac function during TAVI. CONCLUSION: Greater attention should be paid to the patients who plan to undergo TAVI with normal LVEF but poor LVGLS.

16.
Exp Ther Med ; 23(4): 290, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35317441

RESUMO

Gelsolin (GSN) is a calcium-regulated actin-binding protein that can sever actin filaments. Notably, actin dynamics affect the structure and function of epithelial barriers. The present study investigated the role of GSN in the barrier function of pancreatic ductal epithelial cells (PDECs) in hypertriglyceridemia-induced pancreatitis (HTGP). The human PDEC cell line HPDE6-C7 underwent GSN knockdown and was treated with caerulein (CAE) + triglycerides (TG). Intracellular calcium levels and the actin filament network were analyzed under a fluorescence microscope. The expression levels of GSN, E-cadherin, nectin-2, ZO-1 and occludin were evaluated by reverse transcription-quantitative polymerase chain reaction and western blotting. Ultrastructural changes in tight junctions were observed by transmission electron microscopy. Furthermore, the permeability of PDECs was analyzed by fluorescein isothiocyanate-dextran fluorescence. The results revealed that CAE + TG increased intracellular calcium levels, actin filament depolymerization and GSN expression, and increased PDEC permeability by decreasing the expression levels of E-cadherin, nectin-2, ZO-1 and occludin compared with the control. Moreover, changes in these markers, with the exception of intracellular calcium levels, were reversed by silencing GSN. In conclusion, GSN may disrupt barrier function in PDECs by causing actin filament depolymerization in HTGP in vitro.

17.
ACS Appl Mater Interfaces ; 14(12): 14466-14473, 2022 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-35312273

RESUMO

Bottom-up synthesis based on site-selective atomic layer deposition is a powerful atomic-scale processing approach to fabricate materials with desired functionalities. Typical selective atomic layer deposition (ALD) can be achieved using selective activation of a growth area or selective deactivation of a protected area. In this work, we explored the site selectivity based on the difference of the inherent surface reactivity between different materials and within the same materials. By sequentially applying two site-selective atomic layer deposition, the ALD Pd catalyst is spatially confined on ALD SnO2 modified h-BN substrate Pd/SnO2/h-BN shows improved catalytic activity and stability due to strong metal-support interactions and spatial confinement. The results reveal that sequential site-selective ALD is a feasible and effective synthesis strategy that provides an attractive path toward designing and developing highly stable catalysts.

18.
J Org Chem ; 87(6): 4215-4225, 2022 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-35262361

RESUMO

Selective hydroarylation of internal alkynes catalyzed by a dimeric manganese complex provides a powerful strategy for the construction of multisubstituted alkenes. In this work, density functional theory (DFT) calculations and experimental studies were carried out to explore the mechanism and origin of regiodivergent hydroarylation of internal alkynes reported by our group. The results demonstrate that this reaction first proceeds via a bimetallic mechanism to generate the active catalyst that subsequently undergoes a monometallic mechanism to run the three-stage catalytic cycle: alkyne migratory insertion, protonation, and active catalyst regeneration. Alkyne migratory insertion is considered as the regioselectivity-determining step. Energy decomposition analyses on insertion transition states suggest that the interaction between the substrate and catalyst is mainly responsible for the observed exclusive γ-selectivity of 1a, while the deformation of these two sections induced by the sterically hindered phenyl group and aryl group accounts for the complete ß-position arylation of 1e. The decrease of γ-selectivity with the regulation of a tertiary alcohol motif in 1a originates from the reduced noncovalent interaction. The computational results provide important insights into the origin of regiodivergent selectivities and useful information for further designing and adjusting the strategy in Mn-catalyzed alkyne hydroarylation.

19.
J Biochem Mol Toxicol ; : e23039, 2022 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-35279909

RESUMO

The proinflammatory property of cisplatin is potentially destructive and contributes to the pathogenesis of acute kidney injury (AKI). The role and upstream regulatory mechanism of histone acetyltransferase 1 (HAT1) in acute kidney inflammation are still unknown. We performed RNA sequencing to filter differentially expressed microRNAs (miRNAs) in the kidney tissue of mice with AKI induced by cisplatin and ischemia-reperfusion. Here, we found that miR-486-5p was upregulated and that the expression of HAT1 was reduced in AKI mouse models and injured human renal proximal tubular epithelial cell (HK-2) model induced by cisplatin. miR-486-5p is implicated in cisplatin-induced kidney damage in vivo. Bioinformatics analysis predicted a potential binding site between miR-486-5p and HAT1. The Luciferase reporter assay and Western blot confirmed that miR-486-5p directly targeted the 3'-untranslated region of HAT1 mRNA and inhibited its expression in the cytoplasm of HK-2 cells. In the in vitro study, inhibiting miR-486-5p reduced apoptosis, and the expression of proinflammatory mediators was induced by cisplatin in HK-2 cells. Simultaneously, the downregulation of miR-486-5p inhibited the activation of the toll-like receptor 4 (TLR4) and nuclear factor-kappa B (NF-κB). We further found that HAT1 could inhibit apoptosis and the activation of cisplatin on the TLR4/NF-κB pathway and that the upregulation of miR-486-5p reversed this effect. Therefore, the upregulation of miR-486-5p targeting HAT1 promoted the cisplatin-induced apoptosis and acute inflammation response of renal tubular epithelial cells by activating the TLR4/NF-κB pathway, providing a new basis to highlight the potential intervention of regulating the miR-486-5p/HAT1 axis.

20.
Micromachines (Basel) ; 13(3)2022 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-35334715

RESUMO

Piezoelectric micromachined ultrasonic transducers (PMUTs) are a promising alternative to conventional bulk piezoelectric ceramic-based ultrasonic transducers. However, the transmitting sensitivity of the reported PMUTs is far from satisfactory. In this paper, we report a beam-membrane coupled PMUT (BM-PMUT), which enhances the transmitting sensitivity via simultaneously increasing the acoustic emission areas and maintaining the comparable vibration amplitude. Experimental results show that the center and edge transmitting sensitivities of the BM-PMUT are 108.1 and 96 nm/V at 370 kHz, which are 109.9 and 49.6 nm/V at 677 kHz for the traditional PMUT (T-PMUT). Thus, the BM-PMUT realizes piston-like mode shapes and achieves around twofold improvement in the effective acoustic emission area relative to the traditional T-PMUT of the same size. Due to the larger acoustic emission areas and comparable vibration amplitudes, the normalized far-field sound pressure level of the BM-PMUT is 8.5 dB higher than that of the T-PMUT.

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