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1.
J Am Chem Soc ; 146(31): 21677-21688, 2024 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-39042557

RESUMEN

Achieving high guest loading and multiguest-binding capacity holds crucial significance for advancement in separation, catalysis, and drug delivery with synthetic receptors; however, it remains a challenging bottleneck in characterization of high-stoichiometry guest-binding events. Herein, we describe a large-sized coordination cage (MOC-70-Zn8Pd6) possessing 12 peripheral pockets capable of accommodating multiple guests and a high-resolution electrospray ionization mass spectrometry (HR-ESI-MS)-based method to understand the solution host-guest chemistry. A diverse range of bulky guests, varying from drug molecules to rigid fullerenes as well as flexible host molecules of crown ethers and calixarenes, could be loaded into open pockets with high capacities. Notably, these hollow cage pockets provide multisites to capture different guests, showing heteroguest coloading behavior to capture binary, ternary, or even quaternary guests. Moreover, a pair of commercially applied drugs for the combination therapy of chronic lymphocytic leukemia (CLL) has been tested, highlighting its potential in multidrug delivery for combined treatment.


Asunto(s)
Espectrometría de Masa por Ionización de Electrospray , Éteres Corona/química , Calixarenos/química , Paladio/química , Zinc/química , Fulerenos/química , Estructura Molecular
2.
J Am Chem Soc ; 146(29): 20414-20424, 2024 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-38982611

RESUMEN

The structural dynamics of artificial assemblies, in aspects such as molecular recognition and structural transformation, provide us with a blueprint to achieve bioinspired applications. Here, we describe the assembly of redox-switchable chiral metal-organic cages Λ8/Δ8-[Pd6(CoIIL3)8]28+ and Λ8/Δ8-[Pd6(CoIIIL3)8]36+. These isomeric cages demonstrate an on-off chirality logic gate controlled by their chemical and stereostructural dynamics tunable through redox transitions between the labile CoII-state and static CoIII-state with a distinct Cotton effect. The transition between different states is enabled by a reversible redox process and chiral recognition originating in the tris-chelate Co-centers. All cages in two states are thoroughly characterized by NMR, ESI-MS, CV, CD, and X-ray crystallographic analysis, which clarify their redox-switching behaviors upon chemical reduction/oxidation. The stereochemical lability of the CoII-center endows the Λ8/Δ8-CoII-cages with efficient chiral-induction by enantiomeric guests, leading to enantiomeric isomerization to switch between Λ8/Δ8-CoII-cages, which can be stabilized by oxidation to their chemically inert forms of Λ8/Δ8-CoIII-cages. Kinetic studies reveal that the isomerization rate of the Δ8-CoIII-cage is at least an order of magnitude slower than that of the Δ8-CoII-cage even at an elevated temperature, while its activation energy is 16 kcal mol-1 higher than that of the CoII-cage.

3.
Anal Chem ; 96(27): 10943-10952, 2024 07 09.
Artículo en Inglés | MEDLINE | ID: mdl-38918973

RESUMEN

Both controllable regulation of the conformational structure of a polypeptide and specific recognition of an amino acid are still arduous challenges. Here, a novel dual-mode (electrochemical and colorimetric) biosensor was built for arginine (Arg) recognition based on a conformation switch, utilizing controllable and synergistic self-assembly of a ferrocene-grafted hexadecapeptide (P16Fc) with gold nanoparticles (AuNPs). Benefiting from the flexibility and unique topological structure of P16Fc formed nanospheres, the assembly and disassembly can undergo a conformation transition induced by Arg through controlling the distance and number of Fc detached from the gold surface, producing on-off electrical signals. Also, they can induce aggregation and dispersion of AuNPs in solution, causing a color change. The mechanism of Arg recognition with polypeptide conformation regulation was well explored by combining microstructure characterizations with molecular mechanics calculations. The electrochemical and colorimetric assays for Arg were successfully established in sensitive and selective manner, not only obtaining a very low detection limit, but also effectively eliminating the interference from other amino acids and overcoming the limitation of AuNP aggregation. Notably, the conformational change-based assay with the peptide regulated by the target will make a powerful tool for the amino acid biosensing and health diagnosis.


Asunto(s)
Arginina , Técnicas Electroquímicas , Compuestos Ferrosos , Oro , Nanopartículas del Metal , Metalocenos , Péptidos , Arginina/química , Compuestos Ferrosos/química , Metalocenos/química , Oro/química , Nanopartículas del Metal/química , Péptidos/química , Técnicas Biosensibles/métodos , Colorimetría/métodos , Conformación Proteica , Límite de Detección
4.
BMC Cancer ; 24(1): 1148, 2024 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-39277718

RESUMEN

BACKGROUND: Breast cancer (BC) poses significant burdens on women globally. While past research suggests a potential link between bone mineral density (BMD) and BC risk, findings remain inconsistent. Our study aims to elucidate the causal relationship between BMD and BC in East Asians using bidirectional Mendelian randomization (MR). METHODS: Genetic association data for bone mineral density T-scores (BMD-T) and Z-scores (BMD-Z) (Sample size = 92,615) and BC from two different sources (Sample size1 = 98,283; Sample size2 = 79,550) were collected from publicly available genome-wide association studies (GWAS). Single-nucleotide polymorphisms (SNPs) associated with BMD-T and BMD-Z as phenotype-related instrumental variables (IVs) were used, with BC as the outcome. As the primary means of causal inference, the inverse variance weighted (IVW) approach was employed. Heterogeneity analysis was conducted using Cochran's Q test, while MR-Egger regression analysis was implemented to assess the pleiotropic effects of the IVs. Sensitivity analyses were performed using methods such as MR-Egger, weighted median, and weighted mode to analyze the robustness and reliability of the results. The MR-PRESSO method and the RadialMR were used to detect and remove outliers. The PhenoScanner V2 website was utilized to exclude confounding factors shared between BMD and BC. Besides, the Bonferroni correction was also used to adjust the significance threshold. Then, the meta-analysis method was applied to combine the MR analysis results from the two BC sources. Finally, a reverse MR analysis was conducted. RESULTS: The results of the IVW method were consolidated through meta-analysis, revealing a positive correlation between genetically predicted BMD-T ([Formula: see text], [Formula: see text], [Formula: see text]) and BMD-Z ([Formula: see text],[Formula: see text], [Formula: see text]) with increased BC risk. The Cochran's [Formula: see text] test and MR-Egger regression suggested that neither of these causal relationships was affected by heterogeneity or horizontal pleiotropy. The sensitivity analyses supported the IVW results, indicating the robustness of the findings. Reverse MR analysis showed no causal relationship between BC and BMD. CONCLUSION: Our MR study results provide evidence for the causal relationship between BMD and BC risk in East Asian populations, suggesting that BMD screening is of great significance in detecting and preventing BC.


Asunto(s)
Densidad Ósea , Neoplasias de la Mama , Femenino , Humanos , Densidad Ósea/genética , Neoplasias de la Mama/genética , Neoplasias de la Mama/epidemiología , Pueblos del Este de Asia , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Análisis de la Aleatorización Mendeliana , Polimorfismo de Nucleótido Simple , Factores de Riesgo
5.
Front Zool ; 21(1): 10, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38561769

RESUMEN

BACKGROUND: Rapid identification and classification of bats are critical for practical applications. However, species identification of bats is a typically detrimental and time-consuming manual task that depends on taxonomists and well-trained experts. Deep Convolutional Neural Networks (DCNNs) provide a practical approach for the extraction of the visual features and classification of objects, with potential application for bat classification. RESULTS: In this study, we investigated the capability of deep learning models to classify 7 horseshoe bat taxa (CHIROPTERA: Rhinolophus) from Southern China. We constructed an image dataset of 879 front, oblique, and lateral targeted facial images of live individuals collected during surveys between 2012 and 2021. All images were taken using a standard photograph protocol and setting aimed at enhancing the effectiveness of the DCNNs classification. The results demonstrated that our customized VGG16-CBAM model achieved up to 92.15% classification accuracy with better performance than other mainstream models. Furthermore, the Grad-CAM visualization reveals that the model pays more attention to the taxonomic key regions in the decision-making process, and these regions are often preferred by bat taxonomists for the classification of horseshoe bats, corroborating the validity of our methods. CONCLUSION: Our finding will inspire further research on image-based automatic classification of chiropteran species for early detection and potential application in taxonomy.

6.
Inorg Chem ; 63(15): 6692-6700, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38573894

RESUMEN

The fabrication of molecular crystalline materials with fast, multistimuli-responsive behavior and the construction of the corresponding structure-activity relationship are of extraordinary significance for the development of smart materials. In this context, three multistimuli-responsive functional metal-organic polyhedra (MOP), {[Dy2(bcbp)3(NO3)1.5(H2O)7]·Cl4.2·(NO3)0.3·H2O}n (1), {[Dy2(bcbp)4(H2O)8]Cl6}n (2), and {[Eu2(bcbp)4(H2O)10]Cl6·H2O}n (3; bcbp = 1,1'-bis(4-carboxyphenyl)-4,4'-bipyridinium), were successfully prepared and characterized. All of the compounds exhibit rapid and reversible photochromic and electrochromic dual-responsive behaviors. Furthermore, benefiting from the well-defined crystal structure and different responsive behaviors, the photoinduced electron transfer (PIET) process and structure-activity relationship were explored. In addition, considering the excellent photochromic performance, function filter paper and smart organic glass were successfully prepared and used for ink-free printing and UV light detection.

7.
BMC Health Serv Res ; 24(1): 1135, 2024 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-39334309

RESUMEN

BACKGROUND: China accounts for 24% of newly diagnosed cancer cases and 30% of cancer-related deaths worldwide. Comprehensive analyses of the economic burden on patients across different cancer treatment phases, based on empirical data, are lacking. This study aims to estimate the financial burden borne by patients and analyze the cost compositions of the leading cancers with the highest number of new cases in China. METHODS: This cross-sectional cost-of-illness study analyzed patients diagnosed with lung, breast, colorectal, esophageal, liver, or gastric cancer, identified through electronic health records (EHRs) from 84 hospitals across 17 provinces in China. Patients completed any one of the initial treatment phase, follow-up phase, and relapse/metastasis phase were recruited by trained attending physicians through a stratified sampling procedure to ensure enough cases for each cancer progression stage and cancer treatment phase. Direct and indirect costs by treatment phase were collected from the EHRs and self-reported surveys. We estimated per case cost for each type of cancer, and employed subgroup analyses and multiple linear regression models to explore cost drivers. RESULTS: We recruited a total of 13,745 cancer patients across three treatment phases. The relapse/metastasis phase incurred the highest per case costs, varying from $8,890 to $14,572, while the follow-up phase was the least costly, ranging from $1,840 to $4,431. Being in the relapse/metastasis phase and having an advanced clinical stage of cancer at diagnosis were associated with significantly higher cost, while patients with low socioeconomic status borne lower costs. CONCLUSIONS: There were substantial financial burden on patients with six leading cancers in China. Health policymakers should emphasize comprehensive healthcare coverage for marginalized populations such as the uninsured, less educated, and those living in underdeveloped regions.


Asunto(s)
Costo de Enfermedad , Neoplasias , Humanos , China/epidemiología , Estudios Transversales , Masculino , Femenino , Persona de Mediana Edad , Neoplasias/economía , Neoplasias/terapia , Anciano , Adulto , Costos de la Atención en Salud/estadística & datos numéricos , Gastos en Salud/estadística & datos numéricos
8.
Molecules ; 29(6)2024 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-38542969

RESUMEN

Although much promising synthetic progress in conjugated polymer-based organic solar cells (OSCs) has resulted in significant improvement in power conversion efficiencies (PCEs) of from over 15 to >19.0% in the last five years, the sophisticated and complex reactions from at least two families' monomers with remarkably different electron push-pull effects could still pose an unavoidable material burden for the commercialization of OSCs in the coming future. Therefore, the method of preparing a homopolymer from a sole monomer would significantly reduce the synthetic steps and costs in order to pave the way for the large-scale production of OSC materials. Therefore, alkylthio-thiophenyl-substituted benzo[1,2-b;4,5-b']dithiophene (BDTTS) as the sole and key structural moiety with dihalogen and distannyl functional groups was designed and synthesized, respectively, in this study, for facile monomer syntheses and polymerizations to achieve three wide-bandgap homopolymer donors of BDTTS-alt-BDTT-Cl (P13), BDTTS-alt-BDTT (P15), and BDTTS (P14), respectively. The structural symmetry dependency on their physical, electrochemical, and optical properties, thin-film morphologies, and photovoltaic (PV) performance was investigated in detail. As a result, OSCs based on the asymmetric polymer P15, paired with BTP-eC9 as the electron acceptor, presented the best PV performance, with a PCE of 11.5%, a fill factor (FF) of 65.87%, and a short-circuit current (JSC) of 22.04 mA·cm-2, respectively. This PCE value is among the highest ones reported for BDT-type homopolymer donor-based OPVs, providing us with knowledge for obtaining promising PV performance from devices made of P15-like materials.

9.
Angew Chem Int Ed Engl ; 63(29): e202407034, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38708741

RESUMEN

Chirality, a fundamental principle in chemistry, biology, and medicine, is prevalent in nature and in organisms. Chiral molecules, such as DNA, RNA, and proteins, are crucial in biomolecular synthesis, as well as in the development of functional materials. Among these, 1,1'-binaphthyl-2,2'-diol (BINOL) stands out for its stable chiral configuration, versatile functionality, and commercial availability. BINOL is widely employed in asymmetric catalysis and chiral materials. This review mainly focuses on recent research over the past five years concerning the use of BINOL derivatives for constructing chiral macrocycles and cages. Their contributions to chiral luminescence, enantiomeric separation, transmembrane transport, and asymmetric catalysis were examined.

10.
Angew Chem Int Ed Engl ; : e202417593, 2024 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-39384546

RESUMEN

Afterglow materials have garnered significant interest due to distinct photophysical characteristics. However, it is still difficult to achieve long afterglow phosphorescence from organic molecules due to aggregation-caused quenching (ACQ) and energy dissipation. In addition, most materials reported so far have long afterglow emission only at room or even low temperatures, and mainly use UV light as an excitation source. In this work, we report a strategy to achieve high temperature long afterglow emission through the assembly of isolated 0D metal-organic cages (MOCs). In which, both ACQ and phosphorescence quenching effects are effectively mitigated by altering the stacking mode of organic chromophores through orthogonally anchoring into the edges of cubic MOCs. Furthermore, improvement in molecular rigidity, promotion of spin-orbit coupling and broadening of the absorption range are achieved through the MOC- engineering strategy. As a result, we successfully synthesized MOCs that can produce afterglow emission even after excitation by WLEDs at high temperatures (380 K). Moreover, the MOCs are capable of generating afterglow emissions when excited by mobile phone flashlight at room temperature. Given these features, the potential applications of MOCs in the visual identification of explosives, information encryption and multicolor display are explored.

11.
Angew Chem Int Ed Engl ; 63(1): e202313336, 2024 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-37983653

RESUMEN

The precise control of the regioselectivity in the transition metal-catalyzed migratory hydrofunctionalization of alkenes remains a big challenge. With a transient ketimine directing group, the nickel-catalyzed migratory ß-selective hydroarylation and hydroalkenylation of alkenyl ketones has been realized with aryl boronic acids using alkyl halide as the mild hydride source for the first time. The key to this success is the use of a diphosphine ligand, which is capable of the generation of a Ni(II)-H species in the presence of alkyl bromide, and enabling the efficient migratory insertion of alkene into Ni(II)-H species and the sequent rapid chain walking process. The present approach diminishes organosilanes reductant, tolerates a wide array of complex functionalities with excellent regioselective control. Moreover, this catalytic system could also be applied to the migratory hydroarylation of alkenyl azahetereoarenes, thus providing a general approach for the preparation of 1,2-aryl heteroaryl motifs with wide potential applications in pharmaceutical discovery.

12.
Angew Chem Int Ed Engl ; 63(2): e202315053, 2024 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-37883532

RESUMEN

A series of isostructural supramolecular cages with a rhombic dodecahedron shape have been assembled with distinct metal-coordination lability (M8 Pd6 -MOC-16, M=Ru2+ , Fe2+ , Ni2+ , Zn2+ ). The chirality transfer between metal centers generally imposes homochirality on individual cages to enable solvent-dependent spontaneous resolution of Δ8 /Λ8 -M8 Pd6 enantiomers; however, their distinguishable stereochemical dynamics manifests differential chiral phenomena governed by the cage stability following the order Ru8 Pd6 >Ni8 Pd6 >Fe8 Pd6 >Zn8 Pd6 . The highly labile Zn centers endow the Zn8 Pd6 cage with conformational flexibility and deformation, enabling intrigue chiral-Δ8 /Λ8 -Zn8 Pd6 to meso-Δ4 Λ4 -Zn8 Pd6 transition induced by anions. The cage stabilization effect differs from inert Ru2+ , metastable Fe2+ /Ni2+ , and labile Zn2+ , resulting in different chiral-guest induction. Strikingly, solvent-mediated host-guest interactions have been revealed for Δ8 /Λ8 -(Ru/Ni/Fe)8 Pd6 cages to discriminate the chiral recognition of the guests with opposite chirality. These results demonstrate a versatile procedure to control the stereochemistry of metal-organic cages based on the dynamic metal centers, thus providing guidance to maneuver cage chirality at a supramolecular level by virtue of the solvent, anion, and guest to benefit practical applications.

13.
J Am Chem Soc ; 145(42): 23361-23371, 2023 10 25.
Artículo en Inglés | MEDLINE | ID: mdl-37844297

RESUMEN

Molecular recognition lies at the heart of biological functions, which inspires lasting research in artificial host syntheses to mimic biomolecules that can recognize, process, and transport molecules with the highest level of complexity; nonetheless, the design principle and quantifying methodology of artificial hosts for multiple guests (≥4) remain a formidable task. Herein, we report two rhombic dodecahedral cages [(Zn/Fe)8Pd6-MOC-16], which embrace 12 adaptive pockets for multiguest binding with distinct conformational dynamics inherent in metal-center lability and are able to capture 4-24 guests to manifest a surprising complexity of binding scenarios. The exceptional high-order and hierarchical encapsulation phenomena suggest a wide host-guest dynamic-fit, enabling conformational adjustment and adaptation beyond the duality of induced-fit and conformational selection in protein interactions. A critical inspection of the host-guest binding events in solution has been performed by NMR and ESI-MS spectra, highlighting the importance of acquiring a reliable binding repertoire from different techniques and the uncertainty of quantifying the binding affinities of multiplying guests by an oversimplified method.


Asunto(s)
Biomimética , Conformación Molecular
14.
J Org Chem ; 88(6): 3883-3896, 2023 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-36880346

RESUMEN

The direct monofluoroalkenylation of C(sp3)-H bonds is of great importance and quite challenging. Current methods have been restricted to the monofluoroalkenylation of activated C(sp3)-H bonds. Here, we reported the photocatalyzed C(sp3)-H monofluoroalkenylation of inactivated C(sp3)-H bonds with gem-difluoroalkenes via 1,5-hydrogen atom transfer. This process shows good functional group tolerance, such as halides (F, Cl), nitrile, sulfone, ester, and pyridine, and good γ-selectivity. Moreover, this method succeeds in the photocatalyzed gem-difluoroallylation of inactivated C(sp3)-H with α-trifluoromethyl alkenes.

15.
J Org Chem ; 88(24): 17322-17329, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-38044560

RESUMEN

A visible-light-induced annulation/thiolation of 2-isocyanobiaryls with dialkyl(aryl)disulfides has been established, delivering a sustainable and atom-economic route to 6-organoylthiophenanthridines with wild functional group tolerance and good to excellent yields under oxidant-, base-, and transition-metal-free conditions.

16.
Phys Chem Chem Phys ; 25(4): 2916-2925, 2023 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-36637076

RESUMEN

Being fluorine-free and a high performance material as a small organic acceptor molecule, BTP-eC9 has been well mixed with BDT-based PM6 donor polymers for providing satisfactory photovoltaic properties, especially towards future large scale/large area solar cell production. However, as one of the key electrical outputs from such binary active layer materials, the open circuit voltage (VOC) was limited to ca. 0.84 V, which needs to be further improved for BTP-eC9 to have a bright future. This paper focuses on the molecular design of alkylthio- and alkoxy-phenyl flanked benzo[1,2-b:4,5-b']dithiophene-based conjugated polymers (PBDT-PS-ttTPD or P10 for short and PBDT-PO-ttTPD or P11), which were successfully synthesized and applied as donor materials for pairing with BTP-eC9 in organic photovoltaic (OPV) devices. By fine-tuning the side chains of the benzodithiophene (BDT) moiety, such non-fullerene OPV devices with normal configuration demonstrate an attractively high open circuit voltage (VOC) of 0.89 and 0.87 V in P10/BTP-eC9 and P11/BTP-eC9 based binary single bulk heterojunction OPV devices, while still maintaining an excellent JSC of 22.7 and 20.0 mA cm-2 with a final power conversion efficiency (PCE) of 12.93% and 9.37%, respectively. The alkylthio-phenyl chain substituted BDT polymer exhibits better photovoltaic performance in all aspects than the alternative with alkoxy chains due to the synergistic effect of the alkylthio-phenyl flanked BDT, TPD, and π-bridge (thieno[3,2-b]thiophene).

17.
Int J Clin Pract ; 2023: 1489905, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37497125

RESUMEN

Objective: In this study, we aimed to explore the efficacy of the autologous platelet-rich plasma (PRP) interventional circulatory perfusion combined with radiofrequency ablation and thermocoagulation (RFAT) in the treatment of discogenic low back pain (DLBP). Methods: From January 2020 to November 2022, 158 patients of the Second Affiliated Hospital of Nanchang University were selected as the study subjects, and 24 patients met the exclusion criteria. The 134 patients who met the inclusion criteria were divided into 65 patients in the control group (3 patients lost to follow-up) and 69 patients in the observation group (5 patients lost to follow-up), so 126 patients were actually completed the study, including 62 patients in the control group and 64 patients in the observation group. The control group responsible disc received RFAT, and an interventional circulatory perfusion was performed; the observation group received RFAT, and an interventional circulatory perfusion was performed, and then autologous PRP 2 ml was injected. Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) were performed before and 4 and 8 weeks after treatment, and the efficacy was evaluated at 4 and 8 weeks after treatment. The changes of lumbar disc MRI before and after treatment were observed. Results: The differences in the Visual Analog Scale (VAS) scores and the Oswestry Disability Index (ODI) between the observation group and the control group before the treatment were not statistically significant (P > 0.05 in both). However, four weeks and eight weeks after the treatment, the VAS scores and the ODIs were significantly lower in both groups than those before the treatment (P < 0.05 in both). In terms of the therapeutic efficacy, eight weeks after the treatment, the total effective rates in the control group and the observation group were 67.7% and 87.5%, respectively, with the observation group being superior to the control group (P < 0.05). Conclusion: After RFAT, interventional circulatory perfusion combined with autologous PRP intramedullary injection in the lumbar disc is a safe and effective treatment for DLBP, and it had superior long-term effects in improving the clinical symptoms and patient dysfunction than the RFAT and interventional circulatory perfusion.


Asunto(s)
Dolor de la Región Lumbar , Plasma Rico en Plaquetas , Ablación por Radiofrecuencia , Humanos , Dolor de la Región Lumbar/terapia , Resultado del Tratamiento , Electrocoagulación , Perfusión , Vértebras Lumbares/cirugía
18.
Sensors (Basel) ; 23(20)2023 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-37896629

RESUMEN

Due to the strong oxidizing properties of H2O2, excessive discharge of H2O2 will cause great harm to the environment. Moreover, H2O2 is also an energetic material used as fuel, with specific attention given to its safety. Therefore, it is of great importance to explore and prepare good sensitive materials for the detection of H2O2 with a low detection limit and high selectivity. In this work, a kind of hydrogen peroxide electrochemical sensor has been fabricated. That is, polypyrrole (PPy) has been electropolymerized on the glass carbon electrode (GCE), and then Ag and Cu nanoparticles are modified together on the surface of polypyrrole by electrodeposition. SEM analysis shows that Cu and Ag nanoparticles are uniformly deposited on the surface of PPy. Electrochemical characterization results display that the sensor has a good response to H2O2 with two linear intervals. The first linear range is 0.1-1 mM (R2 = 0.9978, S = 265.06 µA/ (mM × cm2)), and the detection limit is 0.027 µM (S/N = 3). The second linear range is 1-35 mM (R2 = 0.9969, 445.78 µA/ (mM × cm2)), corresponding to 0.063 µM of detection limit (S/N = 3). The sensor reveals good reproducibility (σ = 2.104), repeatability (σ = 2.027), anti-interference, and stability. The recoveries of the electrode are 99.84-103.00% (for 0.1-1 mM of linear range) and 98.65-104.80% (for 1-35 mM linear range). Furthermore, the costs of the hydrogen peroxide electrochemical sensor proposed in this work are reduced largely by using non-precious metals without degradation of the sensing performance of H2O2. This study provides a facile way to develop nanocomposite electrochemical sensors.

19.
J Org Chem ; 87(11): 7013-7021, 2022 06 03.
Artículo en Inglés | MEDLINE | ID: mdl-35603573

RESUMEN

Electrocatalytic three-component acylcyanation and aminocyanation of simple alkenes have been developed. The protocol features high functional group tolerance and can easily be scaled up. The key to success is to use an electrophilic cyanation source, enabling a broadened use of alkenes to aliphatic ones for acylcyanation.


Asunto(s)
Alquenos , Catálisis
20.
J Org Chem ; 87(11): 7022-7032, 2022 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-35583475

RESUMEN

The regioselective synthetic approach to higher alkenes from lower alkenes by using sulfoxides as alkyl or aryl reagents in the Fe3+/H2O2 system has been developed. This reaction realized direct alkylation or arylation of alkenes. In this reaction, sulfoxides afforded one Csp3 or Csp2 atom to the C═C bond of alkenes; one new Csp2-Csp3 bond or Csp2-Csp2 bond was formed. Nearly 40 products including di-, tri-, and tetra-substituted products were regioselectively synthesized. Both aliphatic and aromatic alkenes could participate in this reaction. Moreover, not only dimethyl sulfoxide but also three other sulfoxides can be applied to this reaction, including diethyl, dibenzyl, and diphenyl sulfoxide. The mechanism studies showed that this reaction may experience a coupling process via radical addition-elimination and the Fe3+/H2O2 system made the sulfoxides offered one alkyl or aryl radical to the C═C bond of alkenes.

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