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1.
Diabetes Metab Syndr Obes ; 14: 4469-4482, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34795494

RESUMO

Purpose: To analyze the impact of hyperglycemia on the clinical outcome of COVID-19 in patients with newly diagnosed diabetes (NDD). Patients and Methods: We performed a retrospective study of 3114 cases of COVID-19 without pre-existing diabetes, 351 of which had NDD, in Hubei Province, China. The Cox regression model was used to calculate the risk of adverse clinical outcomes comparing the NDD vs non-NDD group before and after propensity score-matched (PSM) analysis. Patients with NDD were further divided into a sustained hyperglycemia group, a fluctuating group, and a remitted group based on their blood glucose levels during hospitalization as well as into hypoglycemic agent users and nonusers. Results: Compared to the non-NDD individuals, individuals with NDD had a significantly increased risk of all-cause mortality (adjusted HR after PSM, 2.65; 95% CI, 1.49-4.72; P = 0.001) and secondary outcomes involving organ damage during the 28-day follow-up period. Subgroup analyses indicated that among individuals with NDD, the individuals with remitted hyperglycemia had the lowest 28-day mortality, whereas those with sustained hyperglycemia had the highest (IRR 24.27; 95% CI, 3.21-183.36; P < 0.001). Moreover, individuals treated with hypoglycemic agents had significantly lower all-cause mortality than those not treated with hypoglycemic agents (IRR 0.08; 95% CI, 0.01-0.56; P < 0.001). Conclusion: Our study reinforces the clinical message that NDD is strongly associated with poor outcomes in COVID-19 patients. Furthermore, resolved hyperglycemia in the later phase of the disease and the use of hypoglycemic agents were associated with improved prognosis in patients with NDD.

2.
Artigo em Inglês | MEDLINE | ID: mdl-34799952

RESUMO

Zn dendrite issue was intensively studied via tuning zinc ion flux. pH change seriously influences dendrite formation, while its importance has not been revealed. Here, we construct a N-modification graphdiyne interface (NGI) to stabilize pH by mediating hydrated zinc ion desolvation. Operando pH detection reveals pH stabilization by NGI. This works with pores in NGI to achieve dendrite-free Zn deposition and an increased symmetric cell lifespan by 116 times. Experimental and theoretical results owe pH stabilization to desolvation with a reduced activation energy achieved by electron transfer from solvation sheath to N atom. The efficient desolvation ensures that electron directly transfers from substrate to Zn2+ (rather than the coordinated H2O), avoiding O-H bond splitting. Hence, Zn-V6O13 battery achieves a long lifespan at 20.65 mA cm-2 and 1.07 mAh cm-2. This work reveals the significance of interface pH and provides a new approach to address Zn dendrite issue.

3.
Commun Biol ; 4(1): 1307, 2021 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-34795381

RESUMO

The domestication and subsequent development of sheep are crucial events in the history of human civilization and the agricultural revolution. However, the impact of interspecific introgression on the genomic regions under domestication and subsequent selection remains unclear. Here, we analyze the whole genomes of domestic sheep and their wild relative species. We found introgression from wild sheep such as the snow sheep and its American relatives (bighorn and thinhorn sheep) into urial, Asiatic and European mouflons. We observed independent events of adaptive introgression from wild sheep into the Asiatic and European mouflons, as well as shared introgressed regions from both snow sheep and argali into Asiatic mouflon before or during the domestication process. We revealed European mouflons might arise through hybridization events between a now extinct sheep in Europe and feral domesticated sheep around 6000-5000 years BP. We also unveiled later introgressions from wild sheep to their sympatric domestic sheep after domestication. Several of the introgression events contain loci with candidate domestication genes (e.g., PAPPA2, NR6A1, SH3GL3, RFX3 and CAMK4), associated with morphological, immune, reproduction or production traits (wool/meat/milk). We also detected introgression events that introduced genes related to nervous response (NEURL1), neurogenesis (PRUNE2), hearing ability (USH2A), and placental viability (PAG11 and PAG3) into domestic sheep and their ancestral wild species from other wild species.

5.
Math Biosci Eng ; 18(6): 9525-9562, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-34814357

RESUMO

This paper presents a model for finding optimal pandemic control policy considering cross-region human mobility. We extend the baseline susceptible-infectious-recovered (SIR) epidemiology model by including the net human mobility from a severely-impacted region to a mildly-affected region. The strategic optimal mitigation policy combining testing and lockdown in each region is then obtained with the goal of minimizing economic cost under the constraint of limited resources. We parametrize the model using the data of the COVID-19 pandemic and show that the optimal response strategy and mitigation outcome greatly rely on the mitigation duration, available resources, and cross-region human mobility. Furthermore, we discuss the economic impact of travel restriction policies through a quantitative analysis.

6.
Am J Ophthalmol ; 2021 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-34818515

RESUMO

PURPOSE: To evaluate the diagnostic yield of congenital ectopia lentis (EL) in a Chinese cohort by combining panel-based next-generation sequencing with clinical findings DESIGN: A cohort study. METHODS: In total, 175 patients with congenital EL and their available family members (n = 338) were enrolled. All congenital EL patients underwent genetic testing. Genotype-phenotype analyses were conducted to assess the biometric and structural ocular manifestations of congenital EL. RESULTS: In total, 175 patients with congenital EL and 338 of their relatives were included in this study. In these patients, 92.57% (162/175) of disease-related variants were detected in FBN1 (83.43%), CPAMD8 (1.71%), COL4A5 (0.57%), ADAMTSL4 (3.43%), LTBP2 (1.71%), and CBS (2.29%). Based on genetic and clinical findings, the primary diagnostic rate was increased to 40.57% from 19.43% with the exception of the 91 diagnoses of potential MFS, with a new diagnostic strategy for congenital ectopia lentis thus having been developed. Within this group of patients harboring FBN1 mutations, 16.44% (19/141) probands were diagnosed with ectopia lentis syndrome (ELS) and 2.13% (3/141) were diagnosed with Marfan syndrome (MFS). CONCLUSIONS: The results of this cohort study expand the genomic landscape associated with congenital EL in Chinese cohorts. FBN1 mutations represent the most common cause of congenital EL in this population, and we have developed a new diagnostic strategy for congenital EL subtypes via the use of a well-designed panel-based next-Generation Sequencing (NGS) which can be used to efficiently and precisely diagnose patients with congenital EL in a cost-effective manner.

7.
Phytochemistry ; 194: 113030, 2021 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-34839132

RESUMO

Panax notoginseng is a highly valuable and widely used herb in traditional Chinese medicine. The quality and efficacy of Panax notoginseng grown under different conditions can greatly vary due to the differences in chemical composition. The analysis of chemical composition in Panax notoginseng typically involves various experimental steps including extraction, chromatographic separation and characterization, which can be time- and labor-consuming. Therefore, the efficient quality assessment and control of Panax notoginseng requires the development of more rapid methods for the chemical characterization and classification of Panax notoginseng. In this study, a method based on internal extractive electrospray ionization mass spectrometry (iEESI-MS) was developed to characterize chemical components of Panax notoginseng samples under different growth conditions (e.g., place of origin, soil quality, growth season) at the speed of 0.5 min per sample, without sample pretreatment and chromatographic separation. A total of 35 chemical components, including sugars, saponins, organic acids, etc., were identified in Panax notoginseng samples. Clear separation was observed in the multivariate analysis of the iEESI-MS data from Panax notoginseng samples grown under different conditions. The difference in the content of sucrose, fructose, Rg1, Rf, Rb1, Noto-R1, malonyl-Rb1, malonyl-Rg1, malonyl-Rf, Rd, Re, linoleic acid, palmitic acid and malic acid can be used as key characteristic indicators to discriminate origin, commercial specifications, and cultivation conditions of Panax notoginseng samples. The results of our study indicate the high power of iEESI-MS for the rapid molecular characterization and classification of Panax notoginseng under different growth conditions, which can be used for the quality assessment of traditional herbal medicines as well as in pharmaceutical and clinical analysis.

8.
Front Immunol ; 12: 704836, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34650552

RESUMO

Intestinal ischemia/reperfusion (I/R) injury is a grave condition with high morbidity and mortality. We previously confirmed that intestinal I/R induces intestinal flora disorders and changes in metabolites, but the role of different metabolites in intestinal I/R injury is currently unclear. Based on targeted metabolic sequencing, pravastatin (PA) was determined to be a metabolite of the gut microbiota. Further, intestinal I/R model mice were established through superior mesenteric artery obstruction. In addition, a co-culture model of small intestinal organoids and type II innate lymphoid cells (ILC2s) was subjected to hypoxia/reoxygenation (H/R) to simulate an intestinal I/R model. Moreover, correlation analysis between the PA level in preoperative feces of patients undergoing cardiopulmonary bypass and the indices of postoperative intestinal I/R injury was carried out. IL-33-deficient mice, ILC2-deleted mice, and anti-IL-13 neutralizing antibodies were also used to explore the potential mechanism through which PA attenuates intestinal I/R injury. We demonstrated that PA levels in the preoperative stool of patients undergoing cardiopulmonary bypass were negatively correlated with the indices of postoperative intestinal I/R injury. Furthermore, PA alleviated intestinal I/R injury and improved the survival of mice. We further showed that PA promotes IL-13 release from ILC2s by activating IL-33/ST2 signaling to attenuate intestinal I/R injury. In addition, IL-13 promoted the self-renewal of intestinal stem cells by activating Notch1 and Wnt signals. Overall, results indicated that the gut microbial metabolite PA can attenuate intestinal I/R injury by promoting the release of IL-13 from ILC2s via IL-33/ST2 signaling, revealing a novel mechanism of and therapeutic strategy for intestinal I/R injury.

9.
Updates Surg ; 2021 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-34655427

RESUMO

Advanced minimally invasive techniques, such as robotic surgeries, are applied increasingly frequently around the world and are primarily used to improve the surgical outcomes of laparoscopic gastrectomy (LG). Against that background, we conducted a meta-analysis to evaluate the feasibility, safety, and effectiveness of robotic gastrectomy (RG). Studies comparing surgical outcomes between LG and RG patients were retrieved from medical databases, including RCTs and non-RCTs. The primary outcome of this study was overall survival, which was obtained by evaluating the 3-year survival rate and the 5-year survival rate. In addition, postoperative complications, mortality, length of hospital stay, and harvested lymph nodes were also assessed. We also conducted subgroup analyses stratified by resection type, body mass index, age, depth of invasion and tumour size. Ultimately, 31 articles met the criterion for our study through an attentive check of each text, including 1 RCT and 30 non-RCTs. A total of 12,401 patients were included in the analysis, with 8127 (65.5%) undergoing LG and 4274 (34.5%) undergoing RG. Compared with LG, RG was associated with fewer postoperative complications (OR 0.81; 95% CI 0.71-0.93; P = 0.002), especially pancreas-related complications (OR 0.376; 95% CI 0.156-0.911; P = 0.030), increased harvested lymph nodes (WMD 2.03; 95% CI 0.95-3.10; P < 0.001), earlier time to first flatus (WMD - 0.105 days; 95% CI - 0.207 to - 0.003; P = 0.044), longer operation time (WMD 40.192 min, 95% CI 32.07-48.31; P < 0.001), less intraoperative blood loss (WMD - 20.09 ml; 95% CI - 26.86 to - 13.32; P < 0.001), and higher expense (WMD 19,141.68 RMB; 95% CI 11,856.07-26,427.29; P < 0.001). There was no significant difference between RG and LG regarding 3-year overall survival (OR 1.030; 95% CI 0.784-1.353; P = 0.832), 5-year overall survival (OR 0.862; 95% CI 0.721-1.031; P = 0.105), conversion rate (OR 0.857; 95% CI 0.443-1.661; P = 0.648), postoperative hospital stay (WMD - 0.368 days; 95% CI - 0.75-0.013; P = 0.059), mortality (OR 1.248; 95% CI 0.514-3.209; P = 0.592), and reoperation (OR 0.855; 95% CI 0.479-1.525; P = 0.595). Our study revealed that postoperative complications, especially pancreas-related complications, occurred less often with RG than with LG. However, long-term outcomes between the two surgical techniques need to be further examined, particularly regarding the oncological adequacy of robotic gastric cancer resections.

10.
Adv Mater ; : e2105426, 2021 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-34612536

RESUMO

Zinc ion batteries (ZIBs), generally established on an excessive metallic Zn anode and aqueous electrolytes, suffer from severe dendrites and gassing issues at Zn side, resulting in poor cycling life. Substituting Zn metal anode with non-Zn ones is a promising strategy for solving these problems, whereas this is still restricted by the limited anode alternatives. Herein, by replacing metal Zn with chalcogen element tellurium (Te), a conversion-type Te-based ZIB is reported that can work in both mild and alkaline electrolytes. As expected, the as-assembled mild Te/MnO2 and alkaline Te/Ni(OH)2 cells deliver remarkable capacities up to 106 and 161 mAh g-1 anode+cathode , respectively, with a high utilization of anode (50.1% for the Te/MnO2 and 38.9% for the Te/Ni(OH)2 ), which surpass all ZIBs. Ultralong cycling life (over 75% capacity retention after 5000 cycles) is achieved in the two systems, benefiting from the stable conversion mechanisms (mild: Te to ZnTe2 to ZnTe; alkaline: ZnTe to Te to TeO2 ) with thoroughly eliminated dendrites and gassing. Moreover, high gravimetric energy density of ZIBs is also achieved, which are 176.3 Wh kg-1 anode+cathdoe (Te/Ni(OH)2 ) and 81 Wh Kg-1 anode+cathode (Te/MnO2 ), respectively. This work sheds light on the development of advanced conversion-type anode for high-performance batteries with superior stability.

11.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 29(5): 1424-1428, 2021 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-34627420

RESUMO

OBJECTIVE: To investigate the relationship between hypoxia inducible factor 1 (HIF1α) and Wilms' tumor 1associating protein (WTAP) expression level in t(8;21) acute myeloid leukemia cells. METHODS: The t(8;21) acute myeloid leukemia cell lines, including SKNO-1 and Kasumi-1 were treated by Echinomycin for 24 h, RT-qPCR and Western blot were used to detect the expression levels of WTAP mRNA and the protein. The CoCl 2 was used to induce the hypoxia of the cells for 24 h, the expression levels of HIF1α, WTAP protein were detected by Western blot. RESULTS: The expression level of WTAP mRNA and the protein in the echinomycin treated group was significantly lower than those in the control group (P<0.01). The expression level of WTAP protein in the CoCl2 treated group was significantly higher than those in the control group (P<0.05). CONCLUSION: The inhibition of HIF1-α could down-regulates the expression of WTAP, while the up-regulation of HIF1α could up-regulates the expression of WTAP, which shows that there is a positive correlation of HIF1α and WTAP expression. This result suggesting that HIF1α may be involves in the expression regulation of WTAP gene.


Assuntos
Proteínas de Ciclo Celular , Leucemia Mieloide Aguda , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia , Leucemia Mieloide Aguda/genética , Proteínas Nucleares , Fatores de Processamento de RNA , RNA Mensageiro
12.
Artigo em Inglês | MEDLINE | ID: mdl-34714571

RESUMO

Efficient synthesis of cyclic polymers has received much attention in polymer chemistry field. Although photochemical cycloaddition of terminal π-bonded units provides a plausible way toward cyclic polymerization, it remains challenging to avoid side reactions by manipulating photochemical selectivity. Herein supramolecular confinement has been developed as a promising strategy to address this issue, by introducing highly directional hydrogen bonds to the photo-reactive cyanostilbenes. The cyanostilbenes units on both ends of a telechelic macromonomer are orientationally aligned with high local concentrations, yielding [2 + 2] photo-cycloaddition products upon 430 nm light irradiation. It leads to the formation of cyclic polymers in the self-assembled state, in stark contrast to Z-E isomerization of cyanostilbenes in the monomeric state. Overall, supramolecular confinement effect exemplified in the current study provides new avenues toward cyclic topological polymers with high synthetic efficiency.

13.
Inorg Chem ; 60(20): 15627-15634, 2021 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-34613720

RESUMO

Spurred by the rapid growth of Ru-based complexes as molecular water oxidation catalysts (WOCs), we propose novel ruthenium(II) complexes bearing pyridylpyrrole-carboxylate (H2ppc) ligands as members of the WOC family. The structure of these complexes has 4-picoline (pic)/dimethyl sulfoxide (DMSO) in [Ru(ppc)(pic)2(dmso)] and pic/pic in [Ru(ppc)(pic)3] as axial ligands. Another ppc2- ligand and one pic ligand are located at the equatorial positions. [Ru(ppc)(pic)2(dmso)] behaves as a WOC as determined by electrochemical measurement and has an ultrahigh electrocatalytic current density of 8.17 mA cm-2 at 1.55 V (vs NHE) with a low onset potential of 0.352 V (vs NHE), a turnover number of 241, a turnover frequency of 203.39 s-1, and kcat of 16.34 s-1 under neutral conditions. The H2O/pic exchange of the complexes accompanied by oxidation of a ruthenium center is the initial step in the catalytic cycle. The cyclic voltametric measurements of [Ru(ppc)(pic)2(dmso)] at various scan rates, Pourbaix diagrams (plots of E vs pH), and kinetic studies suggested a water nucleophilic attack mechanism. HPO42- in a phosphate buffer solution is invoked in water oxidation as the proton acceptor.

14.
Inorg Chem ; 60(21): 16584-16592, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34637291

RESUMO

Interconversion between CO2 + H2 and FA/formate is the most promising strategy for the fixation of carbon dioxide and reversible hydrogen storage; however, FA dehydrogenation and CO2 hydrogenation are usually studied separately using different catalysts for each reaction. This report describes of the catalysis of [Cp*Ir(N∧N)(X)]n+ (Cp* = 1,2,3,4,5-pentamethylcyclopentadienyl; X = Cl, n = 0; X = H2O, n = 1) bearing a proton-responsive N∧N pyridylpyrrole ligand for both reactions. Complex 2-H2O catalyzes FA dehydrogenation at 90 °C with a TOFmax of 45 900 h-1. Its catalysis is more active in aqueous solution than in neat solution under base-free conditions. These complexes also catalyze CO2 hydrogenation in the presence of base to formate under atmospheric pressure (CO2/H2 = 0.05 MPa/0.05 MPa) at 25 °C with a TOF value of 4.5 h-1 in aqueous solution and with a TOF value of 29 h-1 in a methanol/H2O mixture solvent. The possible mechanism is proposed by intermediate characterization and KIE experiments. The extraordinary activity of these complexes are mainly attributed to the metal-ligand cooperative effect of the the pyrrole group to accept a proton in the dehydrogenation of formic acid and assist cooperative heterolytic H-H bond cleavage in CO2 hydrogenation.

15.
Adv Mater ; : e2106180, 2021 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-34699667

RESUMO

High-voltage aqueous rechargeable batteries are promising competitors for next-generation energy storage systems with safety and high specific energy, but they are limited by the absence of low-cost aqueous electrolytes with a wide electrochemical stability window (ESW). The decomposition of aqueous electrolytes is mainly facilitated by the hydrogen bond network between water molecules and the water molecules in the solvation sheath. Here, three types of small dipole molecules (small molecules containing a dipole; glycerol (Gly), erythritol (Et), and acrylamide (AM)) are reported to develop aqueous electrolytes with high safety and wide ESW (over 2.5 V) for aqueous lithium-, sodium-, and zinc-ion batteries, respectively. The solvation-sheath structures are explored by ab initio molecular dynamics (MD) simulations, demonstrating that three types of dipole molecules deplete the water molecules in the solvation sheath of the charge carrier and break the hydrogen bond network between the water molecules, thus effectively expanding the ESW. A battery constructed from lithium titanate and lithium manganate in Gly-containing electrolyte exhibits an output voltage of 2.45 V and retains a specific capacity of 119.6 mAh g-1 after 400 cycles. This work provides another strategy for exploiting low-cost high-voltage electrolytes for aqueous energy-storage systems.

16.
Br J Neurosurg ; : 1-8, 2021 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-34542381

RESUMO

OBJECTIVE: Resection of high-grade glioma with sodium fluorescein can improve the resection rate of the glioma and improve survival. However, it is unclear whether the yellow fluorescence boundary of the high-grade glioma is consistent with the actual boundary of the tumor. This study explores the yellow fluorescence boundary and the actual tumor boundary in high-grade glioma surgery. METHODS: This is a retrospective analysis of 10 patients with high-grade gliomas who underwent tumor visualization with sodium fluorescein. After staining of the tumor, random selections of both developed and non-developed yellow fluorescent border tissue at the fluorescence chromogenic boundary were made, followed by pathological examination. Claudin-5, an important component of the tight connections between vascular endothelial cells, was assessed by immunohistochemistry and qRT-PCR in the tumor and surrounding tissues in order to determine the tumor cell content of the tissue, blood-brain barrier damage, and vascular proliferation. The yellow fluorescence boundary was compared with the actual tumor boundary and the results analyzed. RESULTS: Tumor cells were still detected outside the yellow fluorescence boundary during high-grade glioma surgery (P < 0.05). Claudin-5 expression was higher in high-grade gliomas than in adjacent normal tissues (P < 0.05), while disconnected Claudin-5 expression was associated with intraoperative yellow fluorescence imaging (r = 0.67). CONCLUSIONS: There is a difference between the yellow fluorescence boundary and the actual boundary of the tumor in high-grade glioma, and there are glioma cell infiltrations in the brain tissue of the undeveloped yellow fluorescent border. To ensure patient recovery and function, it is recommended that tumor resection be expanded based on yellow fluorescence visualization. Claudin-5 is overall up-regulated in high-grade gliomas, but some Claudin-5 expression is disconnected. This Claudin-5 expression pattern may be related to the development of yellow fluorescence.

17.
Cell Metab ; 33(10): 1943-1956.e2, 2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34478633

RESUMO

Metabolic dysfunction is becoming a predominant risk for the development of many comorbidities. Ischemic heart disease (IHD) still imposes the highest disease burden among all cardiovascular diseases worldwide. However, the contributions of metabolic risk factors to IHD over time have not been fully characterized. Here, we analyzed the global disease burden of IHD and 15 associated general risk factors from 1990 to 2019 by applying the methodology framework of the Global Burden of Disease Study. We found that the global death cases due to IHD increased steadily during that time frame, while the mortality rate gradually declined. Notably, metabolic risk factors have become the leading driver of IHD, which also largely contributed to the majority of IHD-related deaths shifting from developed countries to developing countries. These findings suggest an urgent need to implement effective measures to control metabolic risk factors to prevent further increases in IHD-related deaths.

18.
ACS Nano ; 15(9): 14631-14642, 2021 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-34478265

RESUMO

The renaissance of aqueous Zn ion batteries has drawn intense attention to Zn metal anode issues, including dendrites growth, dead Zn, low efficiency, and other parasitic reactions. However, against the widely used 2D Zn foil, in fact, the Zn powder anode is a more practical choice for Zn-based batteries in industrial applications, but the related solutions are rarely investigated. Herein, we focus on the Zn powder anode and disclose its unknown failure mechanism different from Zn foils. By utilization of 2D flexible conductive Ti3C2Tx MXene flakes with hexagonal close-packed lattice as electrons and ions redistributor, a stable and highly reversible Zn powder anode without dendrite growth and low polarization is constructed. Low lattice mismatch (∼10%) enables a coherent heterogeneous interface between the (0002) plane of deposited Zn and (0002) plane of the Ti3C2Tx MXene. Thus, the Zn2+ ions are induced to undergo rapid uniform nucleation and sustained reversible stripping/plating with low energy barriers via the internally bridged shuttle channels. Paired with cyano group iron hexacyanoferrate (FeHCF) cathode, the FeHCF//MXene@Zn full battery delivers superior cycle durability and rate capability, whose service life with a CE of near 100% touches 850% of bare Zn powder counterparts. The proposed Ti3C2Tx MXene redistributor strategy concerning high-speed electrons/ions channel, low-barrier heterogeneous interface, is expected to be widely applied to other alkali metal anodes.

19.
Angew Chem Int Ed Engl ; 60(45): 24171-24178, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-34523779

RESUMO

Herein, we report a new strategy for carbon-carbon bond scission and intramolecular ring expansion fluorination of unactivated cyclopropanes, which was accomplished with a new hypervalent fluoroiodane(III) reagent 1. This novel method delivers medicinally relevant 4-fully substituted fluoropiperidines in moderate to high yields with excellent regio- and diastereoselectivity. Reagent 1, which has an N-acetylbenziodazole framework, was readily synthesized via three steps in 76 % overall yield and was characterized by NMR spectroscopy and X-ray crystallography. Owing to the presence of a secondary I⋅⋅⋅O bonding interaction between the λ3 -iodane atom and the carbonyl oxygen of the acetyl group of the N-acetylbenziodazole framework, 1 has excellent stability and can be stored at ambient temperature for 6 months without any detectable decomposition. Density functional theory calculations and experimental studies showed that the reaction proceeds via a carbocation intermediate that readily combines with a fluoride ion to generate the product.

20.
ACS Sens ; 6(10): 3800-3807, 2021 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-34550676

RESUMO

In recent years, the performance research of perovskite materials is not only concentrated in the field of solar cells or optics, but the field of gas sensing has gradually entered the public view. However, the detection of nitric oxide (NO) by lead-free halide perovskites has not yet been reported. Herein, we use Cs2PtI6 to realize the first example of a halide perovskite applied to NO sensing. Due to favoring Pt-N binding, the material has some excellent properties such as a NO detection limit as low as 100 parts-per-billion (ppb), ultrahigh selectivity to NO, and can work at room temperature for more than 2 months. In situ sum frequency generation (SFG) spectra and crystal orbital Hamilton population (COHP) analysis reveal that the strong bonding interaction between Pt 5s and N 2s ensure the high adsorption energy, and Pt 5d electron back donation to N 2px, N 2pz antibonding causes the conductive change of the sensors. In addition, its flexible wearable technology shows the application potential of the device and promotes the further development of perovskite materials.


Assuntos
Compostos de Cálcio , Óxido Nítrico , Óxidos , Titânio
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