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1.
Biodivers Data J ; 12: e129879, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39309533

RESUMEN

Background: This research documents a new record of Miniopterusmagnater in the south-western region of China, a significant discovery given the limited diversity of the Miniopterus genus within the country. Only three species of Miniopterus occur in China: Miniopterusmagnater, Miniopterusfuliginosus and Miniopteruspusillus. These species share a high degree of morphological similarity, particularly in their external characteristics. This underscores the necessity for the identification of additional distinguishing traits that can aid in the taxonomic differentiation of these closely-related species. New information: During the 2023 field expedition to various nature reserves in Yunnan Province, China, we encountered specimens of the genus Miniopterus. Utilising a combination of morphological assessments and phylogenetic analyses, we identified six individuals as Miniopterusmagnater. A review of the existing geographical distribution data revealed that this species is primarily found in central and southern regions of China, with no previous records from the south-western part of the country. Based on our findings, we present a novel record of Miniopterusmagnater's distribution in the south-western region of China.

2.
Materials (Basel) ; 17(10)2024 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-38793337

RESUMEN

The rapid development of additive manufacturing (AM) has facilitated the creation of bionic lightweight, energy-absorbing structures, enabling the implementation of more sophisticated internal structural designs. For protective structures, the utilization of artificially controlled deformation patterns can effectively reduce uncertainties arising from random structural damage and enhance deformation stability. This paper proposed a bionic corrugated lightweight honeycomb structure with controllable deformation. The force on the onset state of deformation of the overall structure was investigated, and the possibility of controlled deformation in the homogeneous structure was compared with that in the corrugated structure. The corrugated structures exhibited a second load-bearing capacity wave peak, with the load-bearing capacity reaching 60.7% to 117.29% of the first load-bearing peak. The damage morphology of the corrugated structure still maintained relative integrity. In terms of energy absorption capacity, the corrugated lightweight structure has a much stronger energy absorption capacity than the homogeneous structure due to the second peak of the load carrying capacity. The findings of this study suggested that the combination of geometric customization and longitudinal corrugation through additive manufacturing offers a promising approach for the development of high-performance energy-absorbing structures.

3.
Parasit Vectors ; 17(1): 238, 2024 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-38802937

RESUMEN

BACKGROUND: Eukaryotic genes contain introns that are removed by the spliceosomal machinery during mRNA maturation. Introns impose a huge energetic burden on a cell; therefore, they must play an essential role in maintaining genome stability and/or regulating gene expression. Many genes (> 50%) in Plasmodium parasites contain predicted introns, including introns in 5' and 3' untranslated regions (UTR). However, the roles of UTR introns in the gene expression of malaria parasites remain unknown. METHODS: In this study, an episomal dual-luciferase assay was developed to evaluate gene expression driven by promoters with or without a 5'UTR intron from four Plasmodium yoelii genes. To investigate the effect of the 5'UTR intron on endogenous gene expression, the pytctp gene was tagged with 3xHA at the N-terminal of the coding region, and parasites with or without the 5'UTR intron were generated using the CRISPR/Cas9 system. RESULTS: We showed that promoters with 5'UTR introns had higher activities in driving gene expression than those without 5'UTR introns. The results were confirmed in recombinant parasites expressing an HA-tagged gene (pytctp) driven by promoter with or without 5'UTR intron. The enhancement of gene expression was intron size dependent, but not the DNA sequence, e.g. the longer the intron, the higher levels of expression. Similar results were observed when a promoter from one strain of P. yoelii was introduced into different parasite strains. Finally, the 5'UTR introns were alternatively spliced in different parasite development stages, suggesting an active mechanism employed by the parasites to regulate gene expression in various developmental stages. CONCLUSIONS: Plasmodium 5'UTR introns enhance gene expression in a size-dependent manner; the presence of alternatively spliced mRNAs in different parasite developmental stages suggests that alternative slicing of 5'UTR introns is one of the key mechanisms in regulating parasite gene expression and differentiation.


Asunto(s)
Regiones no Traducidas 5' , Intrones , Plasmodium yoelii , Regiones Promotoras Genéticas , Regiones no Traducidas 5'/genética , Intrones/genética , Plasmodium yoelii/genética , Plasmodium yoelii/crecimiento & desarrollo , Animales , Expresión Génica , Ratones , Regulación de la Expresión Génica , Sistemas CRISPR-Cas
4.
Nat Commun ; 15(1): 1774, 2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38413566

RESUMEN

Mutations in a Plasmodium de-ubiquitinase UBP1 have been linked to antimalarial drug resistance. However, the UBP1-mediated drug-resistant mechanism remains unknown. Through drug selection, genetic mapping, allelic exchange, and functional characterization, here we show that simultaneous mutations of two amino acids (I1560N and P2874T) in the Plasmodium yoelii UBP1 can mediate high-level resistance to mefloquine, lumefantrine, and piperaquine. Mechanistically, the double mutations are shown to impair UBP1 cytoplasmic aggregation and de-ubiquitinating activity, leading to increased ubiquitination levels and altered protein localization, from the parasite digestive vacuole to the plasma membrane, of the P. yoelii multidrug resistance transporter 1 (MDR1). The MDR1 on the plasma membrane enhances the efflux of substrates/drugs out of the parasite cytoplasm to confer multidrug resistance, which can be reversed by inhibition of MDR1 transport. This study reveals a previously unknown drug-resistant mechanism mediated by UBP1 through altered MDR1 localization and substrate transport direction in a mouse model, providing a new malaria treatment strategy.


Asunto(s)
Antimaláricos , Endopeptidasas , Malaria Falciparum , Plasmodium yoelii , Animales , Ratones , Plasmodium yoelii/genética , Malaria Falciparum/parasitología , Plasmodium falciparum/genética , Antimaláricos/uso terapéutico , Resistencia a Múltiples Medicamentos/genética , Resistencia a Medicamentos/genética
5.
Angew Chem Int Ed Engl ; 63(15): e202317808, 2024 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-38238997

RESUMEN

The self-assembled metal-organic cages (MOCs) have been evolved as a paradigm of enzyme-mimic catalysts since they are able to synergize multifunctionalities inherent in metal and organic components and constitute microenvironments characteristic of enzymatic spatial confinement and versatile host-guest interactions, thus facilitating unconventional organic transformations via unique driving-forces such as weak noncovalent binding and electron/energy transfer. Recently, MOC-based photoreactors emerged as a burgeoning platform of supramolecular photocatalysis, displaying anomalous reactivities and selectivities distinct from bulk solution. This perspective recaps two decades journey of the photoinduced radical reactions by using photoactive metal-organic cages (PMOCs) as artificial reactors, outlining how the cage-confined photocatalysis was evolved from stoichiometric photoreactions to photocatalytic turnover, from high-energy UV-irradiation to sustainable visible-light photoactivation, and from simple radical reactions to multi-level chemo- and stereoselectivities. We will focus on PMOCs that merge structural and functional biomimicry into a single-cage to behave as multi-role photoreactors, emphasizing their potentials in tackling current challenges in organic transformations through single-electron transfer (SET) or energy transfer (EnT) pathways in a simple, green while feasible manner.

6.
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
7.
mBio ; : e0234623, 2023 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-37874152

RESUMEN

Cerebral malaria (CM) is a severe neurological complication of Plasmodium falciparum infection with acute brain lesions. Genetic variations in both host and parasite have been associated with susceptibility to CM, but the underlying molecular mechanism remains unclear. Here, we demonstrate that variants of human apolipoprotein E (hApoE) impact the outcome of Plasmodium berghei ANKA (PbA)-induced experimental cerebral malaria (ECM). Mice carrying the hApoE2 isoform have fewer intracerebral hemorrhages and are more resistant to ECM than mice bearing the hApoE3, hApoE4, or endogenous murine ApoE (mApoE). hApoE2 mice infected with PbA showed increased splenomegaly and IFN-γ levels in serum but reduced cerebral cell apoptosis that correlated with the survival advantage against ECM. In addition, upregulated expression of genes associated with lipid metabolism and downregulated expression of genes linked to immune responses were observed in the brain tissue of hApoE2 mice relative to ECM-susceptible mice after PbA infection. Notably, serum cholesterol and the cholesterol content of brain-infiltrating CD8+ T cells are significantly higher in infected hApoE2 mice, which might contribute to a significant reduction in the sequestration of brain CD8+ T cells. Consistent with the finding that fewer brain lesions occurred in infected hApoE2 mice, fewer behavioral deficits were observed in the hApoE2 mice. Finally, a meta-analysis of publicly available data also showed an increased hApoE2 allele in the malaria-endemic African population, suggesting malaria selection. This study shows that hApoE2 protects mice from ECM through suppression of CD8+ T cell activation and migration to the brain and enhanced cholesterol metabolism.IMPORTANCECerebral malaria (CM) is the deadliest complication of malaria infection with an estimated 15%-25% mortality. Even with timely and effective treatment with antimalarial drugs such as quinine and artemisinin derivatives, survivors of CM may suffer long-term cognitive and neurological impairment. Here, we show that human apolipoprotein E variant 2 (hApoE2) protects mice from experimental CM (ECM) via suppression of CD8+ T cell activation and infiltration to the brain, enhanced cholesterol metabolism, and increased IFN-γ production, leading to reduced endothelial cell apoptosis, BBB disruption, and ECM symptoms. Our results suggest that hApoE can be an important factor for risk assessment and treatment of CM in humans.

8.
Nanomaterials (Basel) ; 13(11)2023 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-37299707

RESUMEN

3D printing technology has been used to directly produce various actual products, ranging from engines and medicines to toys, especially due to its advantage in producing items of complicated, porous structures, which are inherently difficult to clean. Here, we apply micro-/nano-bubble technology to the removal of oil contaminants from 3D-printed polymeric products. Micro-/nano-bubbles show promise in the enhancement of cleaning performance with or without ultrasound, which is attributed to their large specific surface area enhancing the adhesion sites of contaminants, and their high Zeta potential which attracts contaminant particles. Additionally, bubbles produce tiny jets and shock waves at their rupture, driven by coupled ultrasound, which can remove sticky contaminants from 3D-printed products. As an effective, efficient, and environmentally friendly cleaning method, micro-/nano-bubbles can be used in a range of applications.

9.
Angew Chem Int Ed Engl ; 62(25): e202303288, 2023 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-37060207

RESUMEN

A visible light photosensitizing metal-organic cage is applied as an artificial supramolecular reactor to control the reaction of aryl radicals with terminal olefins under green light/solvent conditions, which facilitates selective transformation in the confined enzyme-mimicking environment to give a series of geometrically defined E/Z-alkenes. The hydrophobic cage displays good host-guest inclusion with aromatic substrates, promoting Meerwein arylation and protecting E-isomeric products during reaction; while a small amount of benzonitrile can turn on efficient E→Z isomerization. Besides π-π stacking, the hydrogen bonding and halogen bonding interactions also act as control forces for the arylation of aliphatic terminal olefins known as poor acceptors in classic Meerwein arylation. The application of this switchable cage-confined arylation catalysis has been demonstrated by the syntheses of Tapinarof and a marine natural product from the same substrate via controllable E/Z selectivity.


Asunto(s)
Alquenos , Metales , Alquenos/química , Isomerismo , Catálisis , Halógenos
10.
Inorg Chem ; 61(48): 19232-19239, 2022 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-36395178

RESUMEN

We report two novel titanium-based pnictide oxide compounds (EuF)2Ti2Pn2O (Pn = Sb, Bi), which are synthesized by replacing Sr2+ in (SrF)2Ti2Pn2O [Liu, R. H. Structure and Physical Properties of the Layered Pnictide-Oxides: (SrF)2Ti2Pn2O (Pn = As, Sb) and (SmO)2Ti2Sb2O. Chem. Mater. 2010, 22, 1503-1508] with Eu2+ using a solid-state reaction. (EuF)2Ti2Sb2O exhibits an obvious anomaly in resistivity and heat capacity at T ∼ 195 K, which may arise from the spin-density wave/charge-density wave instability. Similar features are also observed in BaTi2Pn2O, (SrF)2Ti2Pn2O, and Na2Ti2Pn2O (Pn = As and Sb) [Liu, R. H. Structure and Physical Properties of the Layered Pnictide-Oxides: (SrF)2Ti2Pn2O (Pn = As, Sb) and (SmO)2Ti2Sb2O. Chem. Mater. 2010, 22, 1503-1508, Ozawa, T. C. Chemistry of layered d-metal pnictide oxides and their potential as candidates for new superconductors. Sci. Technol. Adv. Mater. 2008, 9, 033003, Wang, X. F. Structure and physical properties for a new layered pnictide-oxide: BaTi2As2O. J. Phys.: Condens. Matter. 2010, 22, 075702, and Xu, H. C. Electronic structure of the BaTi2As2O parent compound of the titanium-based oxypnictide superconductor. Phys. Rev. B 2014, 89, 155108]. Magnetic susceptibility measurements indicate an antiferromagnetic transition at T ∼ 2.5 K for (EuF)2Ti2Sb2O. In particular, the electronic specific heat coefficients of both (EuF)2Ti2Sb2O and (EuF)2Ti2Bi2O are significantly enhanced compared to those of (SrF)2Ti2Pn2O, Na2Ti2Pn2O, and BaTi2Pn2O,1,5,6 which may be due to a strong electron correlation effect in this system. Thus, (EuF)2Ti2Pn2O (Pn = Sb, Bi) may provide new platforms for studying density wave, magnetic ordering, and electron correlation effects.

11.
ACS Nano ; 16(1): 1160-1169, 2022 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-35023714

RESUMEN

Looking for high-performance substrates is an important goal of current surface enhanced Raman scattering (SERS) research. Herein, ultrathin multilayer rhenium (Re) nanosheets as a rare-earth metal substrate are found to have extraordinary SERS performance. These Re nanosheets are prepared through a convenient low-temperature molten salt strategy, and their total thickness is ∼5 nm, including 3-4 layers of ultrathin nanosheets with a thickness of only ∼1 nm. The viscosity of molten salt plays a key role in the formation of these ultrathin layered nanosheets. These nanosheets exhibit a strong and well-defined localized surface plasmon resonance (SPR) effect in the visible light region. The plasmonic Re nanosheets show excellent SERS performance with high sensitivity, chemical stability, and signal repeatability. The lowest detection limit for toxic compounds is 10-12 mol, and the corresponding Raman enhancement factor is 9.1 × 108. A composite enhancement mechanism caused by localized-SPR and charge transport has played an important role in the rare-earth-SERS. High-throughput multiassay analysis is performed on the flexible membrane assembled from the Re nanosheets, which highlights that our system is capable of rapid separation and identification of the samples containing various analytes.

12.
Plant Dis ; 106(1): 260-265, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34402633

RESUMEN

Phoma macdonaldii, the causal agent of sunflower black stem, severely affects sunflower yield and quality. A rapid and sensitive detection method is necessary for diagnosis of this disease. In this study, a loop-mediated isothermal amplification (LAMP) assay was developed for rapid detection of the pathogen from diseased sunflower tissues. The LAMP primers were designed to target the rDNA region of the fungus. The reaction condition was optimized to 60°C water baths for 45 min. The detection limit of the LAMP assay was 100 fg DNA or 10 conidia/g seeds. The LAMP assay was validated by detecting P. macdonaldii from infected sunflower tissue samples, including leaves, stems, and seeds, and applying to seed samples randomly collected from sunflower fields. This LAMP assay will be useful for estimating disease prevalence and implementing sustainable management of sunflower black stem.


Asunto(s)
Ascomicetos , Helianthus , Ascomicetos/genética , Técnicas de Diagnóstico Molecular , Técnicas de Amplificación de Ácido Nucleico
13.
Anal Chem ; 93(37): 12776-12785, 2021 09 21.
Artículo en Inglés | MEDLINE | ID: mdl-34493037

RESUMEN

The development of low-cost, biocompatible, and durable high-performance substrates is an urgent issue in the field of surface-enhanced Raman scattering (SERS). Herein, by reducing and exfoliating the TiO2-layered nanoplates in the gas phase, nitrogen-doped titanium monoxide (N-TiO) ultrathin nanosheets composed of 2-3 single layers with a thickness of only ∼1.2 nm are synthesized. Compared with pure TiO, the oxidation resistance of N-TiO is greatly improved, in which the oxidation threshold is significantly increased from 187.5 to 415.6 °C. The N-TiO ultrathin nanosheets are found to have strong surface plasmon resonance in the visible region. These ultrathin N-TiO nanosheets can be easily assembled into a large-scale flexible membrane and exhibit remarkable SERS effects. Moreover, this low-cost flexible SERS substrate combines the high durability of noble-metal substrates and the high biocompatibility of semiconductor substrates.


Asunto(s)
Espectrometría Raman , Titanio , Óxido Nítrico , Nitrógeno , Resonancia por Plasmón de Superficie
14.
Chem Sci ; 12(31): 10532-10537, 2021 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-34447546

RESUMEN

An efficient palladium-catalyzed AAA reaction with a simple α-sulfonyl carbon anion as nucleophiles is presented for the first time. Allyl fluorides are used as superior precursors for the generation of π-allyl complexes that upon ionization liberate fluoride anions for activation of silylated nucleophiles. With the unique bidentate diamidophosphite ligand ligated palladium as catalyst, the in situ generated α-sulfonyl carbon anion was quickly captured by the allylic intermediates, affording a series of chiral homo-allylic sulfones with high efficiency and selectivity. This work provides a mild in situ desilylation strategy to reveal nucleophilic carbon centers that could be used to overcome the pK a limitation of "hard" nucleophiles in enantioselective transformations.

15.
Opt Express ; 29(5): 7494-7503, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33726249

RESUMEN

Wave plates based on metasurfaces have attracted intensive attention over the past decade owing to their compactness and design flexibility. Although various wave plates have been designed, their working wavelengths are fixed once they are made. Here we present a study on tunable wave plates based on phase-change metasurfaces made of Ge2Sb2Te5 nanopillar structures. The Ge2Sb2Te5 nanopillars can work as a high-efficiency transmissive half- or quarter-wave plate depending on their structural parameters. The working wavelength of wave plate can be tuned via the phase transition of Ge2Sb2Te5. Moreover, the polarization state of the transmitted light at a fixed wavelength can be modified by changing the crystallinity of Ge2Sb2Te5. The features suggest that tunable wave plates may have applications in optical modulators, molecular detection, and polarimetric imaging.

16.
J Am Chem Soc ; 142(52): 21645-21650, 2020 12 30.
Artículo en Inglés | MEDLINE | ID: mdl-33337862

RESUMEN

A novel palladium-mediated carbonylogous 1,4-dipole was developed by in situ deprotonation. By using our own-developed C2-unsymmetric phosphoramidite as supporting ligand, this dipole was applied to the asymmetric synthesis of chiral cyclohexanones via a catalytic [4+2] cycloaddition. Electron-deficient allylic carbonate was used to generate the highly reactive palladium-mediated dipoles for the first time, and a diverse array of stable dipole precursors was explored for the elaboration of chiral cyclohexanones. A general mechanism for the reaction process and stereochemical outcome was proposed, which can be useful in designing and predicting future transformation.

17.
J Am Chem Soc ; 142(43): 18628-18636, 2020 10 28.
Artículo en Inglés | MEDLINE | ID: mdl-33052687

RESUMEN

Design and exploration of new intermediates for chemo-, regio-, and stereoselective cycloadditions remain a formidable challenge in modern organic synthesis. Compared to the well-developed 1,3-dipolar cycloadditions, Pd-catalyzed1,4-dipolar cycloadditions are generally limited to specialized substrates due to the inherent nature of the thermodynamically driven intramolecular transformations and undesired isomerizations. Herein, we demonstrate the use of ligated palladium catalysts to control and modulate the intermolecular reactivity of aliphatic 1,4-dipoles, enabling two distinctive cycloaddition pathways with a broad scope of acceptors. This atom-economic process also features an eco-friendly in situ deprotonation strategy to generate the corresponding active palladium-mediated dipoles. Overall, a diverse array of chiral 6-membered rings and spiro [2.4] heptanes were prepared in high yield and selectivity. In addition, an unexpected property of cyano-stabilized carbanions was discovered and investigated, which can be useful in designing and predicting future transformations.

18.
Sensors (Basel) ; 20(17)2020 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-32825149

RESUMEN

The tire marking points of dynamic balance and uniformity play a crucial guiding role in tire installation. Incomplete marking points block the recognition of tire marking points, and then affect the installation of tires. It is usually necessary to evaluate the marking point completeness during the quality inspection of finished tires. In order to meet the high-precision requirements of the evaluation of tire marking point completeness in the smart factories, the K-means clustering algorithm is introduced to segment the image of marking points in this paper. The pixels within the contour of the marking point are weighted to calculate the marking point completeness on the basis of the image segmentation. The completeness is rated and evaluated by completeness calculation. The experimental results show that the accuracy of the marking point completeness ratings is 95%, and the accuracy of the marking point evaluations is 99%. The proposed method has an important guiding significance of practice to evaluate the tire marking point completeness during the tire quality inspection based on machine vision.

19.
Angew Chem Int Ed Engl ; 59(13): 5341-5345, 2020 03 23.
Artículo en Inglés | MEDLINE | ID: mdl-31965664

RESUMEN

Substituted cyclohexylamines are becoming increasingly important in drug discovery. Asymmetric Heck insertion/amination of nonconjugated cyclodienes proceeds to give 5-aryl cyclohexenylamines with good enantioselectivity and exclusive trans configurations. Primary and secondary anilines, indoline, and benzylamines are suitable amines. The weakly donating diphosphite Kelliphite forms a deep unsymmetrical pocket, which is essential for stereoselective anti attack of amines.

20.
Angew Chem Int Ed Engl ; 59(6): 2246-2250, 2020 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-31691440

RESUMEN

Palladium-catalyzed three-component carboetherification of cyclic alkenes proceeded to give trans adducts exclusively with excellent enantioselectivity through a Wacker-type pathway. The reaction is also applicable to other oxygen nucleophiles, such as water, phenols, and carboxylic acids, as well as some electron-poor aryl amines.

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