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1.
Plant Cell ; 36(5): 1844-1867, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38146915

RESUMEN

Hypothetical chloroplast open reading frames (ycfs) are putative genes in the plastid genomes of photosynthetic eukaryotes. Many ycfs are also conserved in the genomes of cyanobacteria, the presumptive ancestors of present-day chloroplasts. The functions of many ycfs are still unknown. Here, we generated knock-out mutants for ycf51 (sll1702) in the cyanobacterium Synechocystis sp. PCC 6803. The mutants showed reduced photoautotrophic growth due to impaired electron transport between photosystem II (PSII) and PSI. This phenotype results from greatly reduced PSI content in the ycf51 mutant. The ycf51 disruption had little effect on the transcription of genes encoding photosynthetic complex components and the stabilization of the PSI complex. In vitro and in vivo analyses demonstrated that Ycf51 cooperates with PSI assembly factor Ycf3 to mediate PSI assembly. Furthermore, Ycf51 interacts with the PSI subunit PsaC. Together with its specific localization in the thylakoid membrane and the stromal exposure of its hydrophilic region, our data suggest that Ycf51 is involved in PSI complex assembly. Ycf51 is conserved in all sequenced cyanobacteria, including the earliest branching cyanobacteria of the Gloeobacter genus, and is also present in the plastid genomes of glaucophytes. However, Ycf51 has been lost from other photosynthetic eukaryotic lineages. Thus, Ycf51 is a PSI assembly factor that has been functionally replaced during the evolution of oxygenic photosynthetic eukaryotes.


Asunto(s)
Proteínas Bacterianas , Sistemas de Lectura Abierta , Complejo de Proteína del Fotosistema I , Synechocystis , Complejo de Proteína del Fotosistema I/metabolismo , Complejo de Proteína del Fotosistema I/genética , Synechocystis/genética , Synechocystis/metabolismo , Sistemas de Lectura Abierta/genética , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Cloroplastos/metabolismo , Fotosíntesis/genética , Tilacoides/metabolismo , Complejo de Proteína del Fotosistema II/metabolismo , Complejo de Proteína del Fotosistema II/genética , Mutación
2.
Proc Natl Acad Sci U S A ; 121(14): e2321645121, 2024 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-38527201

RESUMEN

Central Asia (CA) is one of the world's most significant arid regions, which is markedly impacted by global warming. A better understanding of the dynamical processes governing its Holocene climate variability is critical for a better understanding of possible future impacts of climate change in the region. To date, most of the existing CA paleoclimate records are from the summer precipitation-dominated eastern CA (ECA), with few records from the winter precipitation-dominated western CA (WCA). Here, we present a precisely dated (~6‰) and highly resolved (<4-y) record of hydroclimatic variations from the WCA covering the period between 7,774 and 656 y BP. Utilizing multiple proxies (δ18O, δ13C, and Sr/Ca) derived from a stalagmite from the Fergana Valley, Kyrgyzstan, we reveal a long-term drying trend in WCA, which is in contrast with the wetting trend in ECA. We propose that different responses of winter and summer westerly jets to seasonal solar insolation over the past 8,000 y may have resulted in an antiphased precipitation relationship between the WCA and ECA. Our data contain dominant quasiperiodicities of 1,400, 50 to 70, and 20 to 30 y, indicating close connections between the WCA climate and the North Atlantic. We further identified a series of droughts and pluvials on centennial-to-decadal timescales, which may have influenced regional societies and trans-Eurasian culture exchanges during historical and prehistorical times.

3.
PLoS Genet ; 20(1): e1011037, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38206971

RESUMEN

Explicitly sharing individual level data in genomics studies has many merits comparing to sharing summary statistics, including more strict QCs, common statistical analyses, relative identification and improved statistical power in GWAS, but it is hampered by privacy or ethical constraints. In this study, we developed encG-reg, a regression approach that can detect relatives of various degrees based on encrypted genomic data, which is immune of ethical constraints. The encryption properties of encG-reg are based on the random matrix theory by masking the original genotypic matrix without sacrificing precision of individual-level genotype data. We established a connection between the dimension of a random matrix, which masked genotype matrices, and the required precision of a study for encrypted genotype data. encG-reg has false positive and false negative rates equivalent to sharing original individual level data, and is computationally efficient when searching relatives. We split the UK Biobank into their respective centers, and then encrypted the genotype data. We observed that the relatives estimated using encG-reg was equivalently accurate with the estimation by KING, which is a widely used software but requires original genotype data. In a more complex application, we launched a finely devised multi-center collaboration across 5 research institutes in China, covering 9 cohorts of 54,092 GWAS samples. encG-reg again identified true relatives existing across the cohorts with even different ethnic backgrounds and genotypic qualities. Our study clearly demonstrates that encrypted genomic data can be used for data sharing without loss of information or data sharing barrier.


Asunto(s)
Estudio de Asociación del Genoma Completo , Privacidad , Humanos , Estudio de Asociación del Genoma Completo/métodos , Genotipo , Programas Informáticos , Genómica
4.
Proc Natl Acad Sci U S A ; 120(7): e2218813120, 2023 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-36745798

RESUMEN

Efficient H2 harvesting from wastewater instead of pure water can minimize fresh water consumption, which is expected to solve the problem of water shortage in H2 production process and contribute to carbon neutrality in the environmental remediation, but the inevitable electron depletion caused by electron-consuming pollutants will result in an exhausted H2 evolution reaction (HER) performance. In this paper, by coupling piezocatalysis and advanced oxidation processes (AOPs) by a MoS2/Fe0/peroxymonosulfate (PMS) ternary system, extensive types of wastewater achieved considerable H2 generation, which exceeded the yield in pure water with synchronous advanced degradation of organic pollutants. In addition, profiting from the crucial bridging role of PMS, the H2 yield in nitrobenzene wastewater after the introduction of PMS-based AOPs increased 3.37-fold from 267.7 µmol·g-1·h-1 to 901.0 µmol·g-1·h-1 because the presence of PMS both thermodynamically benefited MoS2 piezocatalytic H2 evolution and eliminated the electron depletion caused by organic pollutants. By this way, the original repressed H2 evolution performance in substrate of wastewater not only was regained but even showed a significant enhancement than that in pure water (505.7 µmol·g-1·h-1). Additionally, the cyclonic piezoelectric reactor was preliminarily designed for future industrialization. This strategy provided a valuable path for the recycling of actual wastewater by fuel production and synchronous advanced treatment.

5.
Exp Cell Res ; 440(2): 114139, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38908423

RESUMEN

Pelvic organ prolapse (POP) is a group of diseases caused by extracellular matrix (ECM) degradation in pelvic supportive tissues. Cysteine and serine rich nuclear protein 1 (CSRNP1) is involved in cell proliferation and survival regulation, and reportedly facilitates collagen breakdown in human chondrocytes. The present study aimed to probe the effect of CSRNP1 on collagen metabolism in human-derived vaginal fibroblasts. High expression of CSRNP1 was found in POP patient-derived vaginal fibroblasts in comparison to normal-derived vaginal fibroblasts. Following functional experiments revealed that CSRNP1 overexpression led to proliferation inhibition, apoptosis and collagen degradation in normal vaginal fibroblasts. In line with this, silencing of CSRNP1 inhibited hydrogen peroxide (H2O2)-triggered apoptosis, ROS generation and collagen loss in normal vaginal fibroblasts. Silencing of CSRNP1 also reduced the expression of cell senescence markers p21 and γ-H2Ax (the histone H2Ax phosphorylated at Ser139), as well as curbed collagen breakdown in normal vaginal fibroblasts caused by a DNA damage agent etoposide. Transcriptomic analysis of vaginal fibroblasts showed that differentially expressed genes affected by CSRNP1 overexpression were mainly enriched in the Wnt signaling pathway. Treatment with a Wnt pathway inhibitor DKK1 blocked CSRNP1 knockdown-caused collagen deposition. Mechanistically, CSRNP1 was identified to be a target of Snail family transcriptional repressor 2 (SNAI2). Forced expression of CSRNP1 reversed the anti-apoptotic, anti-senescent and anti-collagen loss effects of SNAI2 in normal vaginal fibroblasts exposed to H2O2 or etoposide. Our study indicates that the SNAI2/CSRNP1 axis may be a key driver in POP progression, which provides a potential therapeutic strategy for POP.


Asunto(s)
Apoptosis , Senescencia Celular , Colágeno , Daño del ADN , Fibroblastos , Estrés Oxidativo , Vagina , Humanos , Femenino , Fibroblastos/metabolismo , Apoptosis/genética , Senescencia Celular/genética , Vagina/metabolismo , Vagina/citología , Vagina/patología , Colágeno/metabolismo , Peróxido de Hidrógeno/farmacología , Proliferación Celular , Prolapso de Órgano Pélvico/metabolismo , Prolapso de Órgano Pélvico/genética , Prolapso de Órgano Pélvico/patología , Factores de Transcripción de la Familia Snail/metabolismo , Factores de Transcripción de la Familia Snail/genética , Silenciador del Gen , Células Cultivadas
6.
Proc Natl Acad Sci U S A ; 119(42): e2211244119, 2022 10 18.
Artículo en Inglés | MEDLINE | ID: mdl-36215485

RESUMEN

Desert-inhabiting cyanobacteria can tolerate extreme desiccation and quickly revive after rehydration. The regulatory mechanisms that enable their vegetative cells to resurrect upon rehydration are poorly understood. In this study, we identified a single gene family of high light-inducible proteins (Hlips) with dramatic expansion in the Nostoc flagelliforme genome and found an intriguingly special convergence formed through four tandem gene duplication. The emerged four independent hlip genes form a gene cluster (hlips-cluster) and respond to dehydration positively. The gene mutants in N. flagelliforme were successfully generated by using gene-editing technology. Phenotypic analysis showed that the desiccation tolerance of hlips-cluster-deleted mutant decreased significantly due to impaired photosystem II repair, whereas heterologous expression of hlips-cluster from N. flagelliforme enhanced desiccation tolerance in Nostoc sp. PCC 7120. Furthermore, a transcription factor Hrf1 (hlips-cluster repressor factor 1) was identified and shown to coordinately regulate the expression of hlips-cluster and desiccation-induced psbAs. Hrf1 acts as a negative regulator for the adaptation of N. flagelliforme to the harsh desert environment. Phylogenetic analysis revealed that most species in the Nostoc genus possess both tandemly repeated Hlips and Hrf1. Our results suggest convergent evolution of desiccation tolerance through the coevolution of tandem Hlips duplication and Hrf1 in subaerial Nostoc species, providing insights into the mechanism of desiccation tolerance in photosynthetic organisms.


Asunto(s)
Nostoc , Complejo de Proteína del Fotosistema II , Desecación , Nostoc/metabolismo , Complejo de Proteína del Fotosistema II/metabolismo , Filogenia , Factores de Transcripción/metabolismo
7.
J Am Chem Soc ; 146(11): 7178-7184, 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38466344

RESUMEN

In the field of catalytic asymmetric synthesis, the less-treated path lies in oxidative catalytic asymmetric transformations. The hurdles of pinpointing the appropriate chemical oxidants and addressing their compatibility issues with catalysts and functionalities present significant challenges. Organic electrochemistry, employing traceless electrons for redox reactions, is underscored as a promising solution. However, the commonly used electrolysis in batch cells introduces its own set of challenges, hindering the advancement of electrochemical asymmetric catalysis. Here we introduce a microfluidic electrochemistry platform with single-pass continuous flow reactors that exhibits a wide-ranging applicability to various oxidative asymmetric catalytic transformations. This is exemplified through the sulfenylation of 1,3-dicarbonyls, dehydrogenative C-C coupling, and dehydrogenative alkene annulation processes. The unique properties of microfluidic electrochemical reactors not only eliminate the need for chemical oxidants but also enhance reaction efficiency and reduce the use of additives and electrolytes. These salient features of microfluidic electrochemistry expedite the discovery and development of oxidative asymmetric transformations. In addition, the continuous production facilitated by parallel single-pass reactors ensures straightforward reaction upscaling, removing the necessity for reoptimization across various scales, as evidenced by direct translation from milligram screening to hectogram asymmetric synthesis.

8.
J Am Chem Soc ; 2024 Jul 09.
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.

9.
Small ; : e2311058, 2024 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-38351656

RESUMEN

The design of smart stimuli-responsive photoluminescent materials capable of multi-level encryption and complex information storage is highly sought after in the current information era. Here, a novel adamantyl-capped CsPbBr3 (AD-CsPbBr3 ) perovskite NCs, along with its supramolecular host-guest assembly partner a modified ß-CD (mCD), mCD@AD-CsPbBr3 , are designed and prepared. By dispersing these two materials in different solvents, namely, AD-CsPbBr3 in toluene, mCD@AD-CsPbBr3 in toluene, and mCD@AD-CsPbBr3 in methanol, the three solutions exhibit diverse photoluminescence (PL) turn-on/off or PL discoloration response upon supramolecular stimulus. Based on these responses, a proof-of-principle programmable Multi-Level Photoluminescence Encoding System (MPLES) is established. Three types of four-level and three types of three-level information encoding are achieved by the system. A layer-by-layer four-level information encryption and decryption as well as a two-level encrypted 3D code are successfully achieved.

10.
Small ; 20(1): e2304463, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37649191

RESUMEN

The high activity of water molecules results in a series of awful parasitic reaction, which seriously impede the development of aqueous zinc batteries. Herein, a new gel electrolyte with multiple molecular anchors is designed by employing natural biomaterials from chitosan and chlorophyll derivative. The gel electrolyte firmly anchors water molecules by ternary hydrogen bonding to reduce the activity of water molecules and inhibit hydrogen evolution reaction. Meanwhile, the multipolar charged functional groups realize the gradient induction and redistribution of Zn2+ , which drives oriented Zn (002) plane deposition of Zn2+ and then achieves uniform Zn deposition and dendrite-free anode. As a result, it endows the Zn||Zn cell with over 1700 h stripping/plating processes and a high efficiency of 99.4% for the Zn||Cu cell. In addition, the Zn||V2 O5 full cells also exhibit capacity retention of 81.7% after 600 cycles at 0.5 A g-1 and excellent long-term stability over 1600 cycles at 2 A g-1 , and the flexible pouch cells can provide stable power for light-emitting diodes even after repeated bending. The gel electrolyte strategy provides a reference for reversible zinc anode and flexible wearable devices.

11.
Small ; 20(5): e2304424, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37726235

RESUMEN

Peptide assemblies are promising nanomaterials, with their properties and technological applications being highly hinged on their supramolecular architectures. Here, how changing the chirality of the terminal charged residues of an amphiphilic hexapeptide sequence Ac-I4 K2 -NH2 gives rise to distinct nanostructures and supramolecular handedness is reported. Microscopic imaging and neutron scattering measurements show thin nanofibrils, thick nanofibrils, and wide nanotubes self-assembled from four stereoisomers. Spectroscopic and solid-state nuclear magnetic resonance (NMR) analyses reveal that these isomeric peptides adopt similar anti-parallel ß-sheet secondary structures. Further theoretical calculations demonstrate that the chiral alterations of the two C-terminal lysine residues cause the formation of diverse single ß-strand conformations, and the final self-assembled nanostructures and handedness are determined by the twisting direction and degree of single ß-strands. This work not only lays a useful foundation for the fabrication of diverse peptide nanostructures by manipulating the chirality of specific residues but also provides a framework for predicting the supramolecular structures and handedness of peptide assemblies from single molecule conformations.


Asunto(s)
Lateralidad Funcional , Nanoestructuras , Péptidos/química , Nanoestructuras/química , Isomerismo , Estructura Secundaria de Proteína
12.
Nat Mater ; 22(7): 832-837, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36894772

RESUMEN

The scaling of silicon-based transistors at sub-ten-nanometre technology nodes faces challenges such as interface imperfection and gate current leakage for an ultrathin silicon channel1,2. For next-generation nanoelectronics, high-mobility two-dimensional (2D) layered semiconductors with an atomic thickness and dangling-bond-free surfaces are expected as channel materials to achieve smaller channel sizes, less interfacial scattering and more efficient gate-field penetration1,2. However, further progress towards 2D electronics is hindered by factors such as the lack of a high dielectric constant (κ) dielectric with an atomically flat and dangling-bond-free surface3,4. Here, we report a facile synthesis of a single-crystalline high-κ (κ of roughly 16.5) van der Waals layered dielectric Bi2SeO5. The centimetre-scale single crystal of Bi2SeO5 can be efficiently exfoliated to an atomically flat nanosheet as large as 250 × 200 µm2 and as thin as monolayer. With these Bi2SeO5 nanosheets as dielectric and encapsulation layers, 2D materials such as Bi2O2Se, MoS2 and graphene show improved electronic performances. For example, in 2D Bi2O2Se, the quantum Hall effect is observed and the carrier mobility reaches 470,000 cm2 V-1 s-1 at 1.8 K. Our finding expands the realm of dielectric and opens up a new possibility for lowering the gate voltage and power consumption in 2D electronics and integrated circuits.


Asunto(s)
Grafito , Silicio , Electrónica , Semiconductores
13.
Nat Mater ; 22(4): 489-494, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36959503

RESUMEN

Pressure-induced magnetic phase transitions are attracting interest as a means to detect superconducting behaviour at high pressures in diamond anvil cells, but determining the local magnetic properties of samples is a challenge due to the small volumes of sample chambers. Optically detected magnetic resonance of nitrogen vacancy centres in diamond has recently been used for the in situ detection of pressure-induced phase transitions. However, owing to their four orientation axes and temperature-dependent zero-field splitting, interpreting these optically detected magnetic resonance spectra remains challenging. Here we study the optical and spin properties of implanted silicon vacancy defects in 4H-silicon carbide that exhibit single-axis and temperature-independent zero-field splitting. Using this technique, we observe the magnetic phase transition of Nd2Fe14B at about 7 GPa and map the critical temperature-pressure phase diagram of the superconductor YBa2Cu3O6.6. These results highlight the potential of silicon vacancy-based quantum sensors for in situ magnetic detection at high pressures.

14.
Plant Physiol ; 193(3): 2180-2196, 2023 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-37471276

RESUMEN

Rice (Oryza sativa L.) is a cold-sensitive species that often faces cold stress, which adversely affects yield productivity and quality. However, the genetic basis for low-temperature adaptation in rice remains unclear. Here, we demonstrate that 2 functional polymorphisms in O. sativa SEC13 Homolog 1 (OsSEH1), encoding a WD40-repeat nucleoporin, between the 2 subspecies O. sativa japonica and O. sativa indica rice, may have facilitated cold adaptation in japonica rice. We show that OsSEH1 of the japonica variety expressed in OsSEH1MSD plants (transgenic line overexpressing the OsSEH1 allele from Mangshuidao [MSD], cold-tolerant landrace) has a higher affinity for O. sativa metallothionein 2b (OsMT2b) than that of OsSEH1 of indica. This high affinity of OsSEH1MSD for OsMT2b results in inhibition of OsMT2b degradation, with decreased accumulation of reactive oxygen species and increased cold tolerance. Transcriptome analysis indicates that OsSEH1 positively regulates the expression of the genes encoding dehydration-responsive element-binding transcription factors, i.e. OsDREB1 genes, and induces the expression of multiple cold-regulated genes to enhance cold tolerance. Our findings highlight a breeding resource for improving cold tolerance in rice.


Asunto(s)
Oryza , Oryza/metabolismo , Fitomejoramiento , Frío , Oxidación-Reducción , Homeostasis , Regulación de la Expresión Génica de las Plantas
15.
FASEB J ; 37(5): e22895, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-37000564

RESUMEN

Lactobacillus species is one of the most commonly used probiotics with a wide range of health-promoting effects, and beneficial effects of the surface protein of the lactobacillus could potentially be involved in the action of probiotics in the gastrointestinal tract. In this study, the anti-inflammatory effect of LPxTG-motif surface protein (LMP) derived from Limosilactobacillus reuteri SH 23 was assessed using a mouse model of colitis induced by dextran sodium sulfate (DSS). The results showed that LMP has the inhibition properties upon the DSS-induced ulcerative colitis of mice via the MAPK-dependent NF-κB pathway. The inflammatory factors TNF-α and IL-6 were inhibited, and the IL-10 secretion was enhanced in the LMP-treated DSS mice model. Furthermore, the diversity of the intestinal microbiota bacteria in this treated group was also influenced, including the increase in the abundance of Lactobacillus and Akkermansia genus in the LMP-treated mice groups, and there is a positive correlation between the IL-10 cytokines with the changes in the intestinal microbiota Lactobacillus and Akkermansia. Therefore, LMP derived from the Limosilactobacillus reuteri SH 23 has the potential to alleviate inflammatory diseases through the balance of the intestinal flora with the inhibition of the inflammatory factors in the NF-κB pathway.


Asunto(s)
Colitis Ulcerosa , Colitis , Limosilactobacillus reuteri , Animales , Ratones , Colitis Ulcerosa/inducido químicamente , Colitis Ulcerosa/metabolismo , Interleucina-10/metabolismo , FN-kappa B/metabolismo , Proteínas de la Membrana/metabolismo , Colitis/metabolismo , Modelos Animales de Enfermedad , Sulfato de Dextran/toxicidad , Ratones Endogámicos C57BL , Colon/metabolismo
16.
Chemphyschem ; 25(5): e202300960, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38179835

RESUMEN

Prussian blue analogues (PBAs) have advantages such as high voltage and low cost, making them one kind of the promising positive electrode materials for sodium-ion batteries. Particle dispersion is a key physical parameter of electrode materials, and understanding its impact on electrochemical performance is a prerequisite for obtaining high-performance PBAs. In this article, two PBAs samples with different particle dispersion were synthesized through sodium citrate-assisted co-precipitation method by means of staying and stirring. The influence of particle dispersion on electrochemical performance was investigated through polarization curve and AC impedance tests. It was found that PBAs with well-dispersed particles exhibited excellent rate performance, with a capacity of ~120 mAh g-1 at 1 C rate and a capacity retention of 75 % after 100 cycles. The capacity retention rate could reach 63 % at 5 C rate, far higher than that of PBAs samples with poor particle dispersion. From the perspective of electrochemical kinetics analysis, it has been shown that PBAs with well-dispersed particles exhibit smaller electrochemical polarization and faster Na+ diffusion reaction kinetics, which are key factors in achieving excellent rate performance.

17.
Langmuir ; 40(22): 11806-11816, 2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38770910

RESUMEN

Antibacterial peptides (ABPs) have been recognized as promising alternatives to conventional antibiotics due to their broad antibacterial spectrum, high antibacterial activity, and low possibility of inducing bacterial resistance. However, their antibiofilm mechanisms have not yet reached a consensus. In this study, we investigated the antibiofilm activity of a short helical peptide G3 against Staphylococcus epidermidis, one of the most important strains of medical device contamination. Studies show that G3 inhibits S. epidermidis biofilm formation in a variety of ways. In the initial adhesion stage, G3 changes the properties of bacterial surfaces, such as charges, hydrophobicity, and permeability, by rapidly binding to them, thus interfering with their initial adhesion. In the mature stage, G3 prefers to target extracellular polysaccharides, leading to the death of outside bacteria and the disruption of the three-dimensional (3D) architecture of the bacterial biofilm. Such efficient antibiofilm activity of G3 endows it with great potential in the treatment of infections induced by the S. epidermidis biofilm.


Asunto(s)
Antibacterianos , Biopelículas , Staphylococcus epidermidis , Staphylococcus epidermidis/efectos de los fármacos , Staphylococcus epidermidis/fisiología , Biopelículas/efectos de los fármacos , Antibacterianos/farmacología , Antibacterianos/química , Pruebas de Sensibilidad Microbiana , Péptidos/farmacología , Péptidos/química
18.
J Org Chem ; 89(7): 4438-4443, 2024 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-38471105

RESUMEN

A straight and efficient protocol for the synthesis of hindered indole-ethers via C-H alkoxylation of indoles was developed by a cobalt-catalyzed cross-dehydrogenative coupling reaction with secondary alcohols. The selection of the salicylaldehyde-Co(II) catalyst enables the reaction to proceed under conditions without acid or base addition in the presence of limited alcohols. The protocol has broad substrate scope for both indole and secondary alcohols and exhibits good functional tolerance. The synthetic applications are proven by gram-scale reaction and further diversification of the product. Preliminary mechanistic investigations indicate that the activation of C-H bonds is not the rate-determining step of the reaction.

19.
Inorg Chem ; 63(17): 7555-7559, 2024 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-38624233

RESUMEN

Noncentrosymmetric chalcogenides are promising candidates for infrared nonlinear-optical (NLO) crystals, and exploring high-performance ones is a hot topic and challengeable. Herein, the combination of AgQ4, InQ4, and SiQ4 (Q = S, Se) units with different S/Se ratios resulted in the discovery of the tetrahedral chalcogenides Ag2In2SiS4Se2 (1) and Ag2In2SiS5Se (2). They both crystallize in the monoclinic Cc space group with different local structures. Co-occupied S/Se sites only exist in 2, and the arrangement of [In2SiQ3] six-membered rings builds different helical chains and 3D [(In2SiQ6)2-]n polyanionic frameworks in 1 and 2. They show balanced NLO performances, including phase-matchable moderate NLO responses (0.7 and 0.5 × AGS) and enhanced laser-induced damage thresholds (4.5 and 5.1 × AGS). Theoretical calculations reveal that their NLO responses are predominantly contributed by the AgQ4 and InQ4 units.

20.
Phys Chem Chem Phys ; 26(10): 7988-8012, 2024 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-38380525

RESUMEN

Artificial materials, characterized by their distinctive properties and customized functionalities, occupy a central role in a wide range of applications including electronics, spintronics, optoelectronics, catalysis, and energy storage. The emergence of atomically thin two-dimensional (2D) materials has driven the creation of artificial heterostructures, harnessing the potential of combining various 2D building blocks with complementary properties through the art of stacking engineering. The promising outcomes achieved for heterostructures have spurred an inquisitive exploration of homostructures, where identical 2D layers are precisely stacked. This perspective primarily focuses on the field of stacking engineering within layered homostructures, where precise control over translational or rotational degrees of freedom between vertically stacked planes or layers is paramount. In particular, we provide an overview of recent advancements in the stacking engineering applied to 2D homostructures. Additionally, we will shed light on research endeavors venturing into three-dimensional (3D) structures, which allow us to proactively address the limitations associated with artificial 2D homostructures. We anticipate that the breakthroughs in stacking engineering in 3D materials will provide valuable insights into the mechanisms governing stacking effects. Such advancements have the potential to unlock the full capability of artificial layered homostructures, propelling the future development of materials, physics, and device applications.

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