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1.
Opt Lett ; 49(10): 2557-2560, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38748104

RESUMO

The inherent nonseparability of vector beams presents a unique opportunity to explore novel optical functionalities, expanding new degrees of freedom for optical information processing. In this Letter, we introduce a novel, to the best of our knowledge, method for tailoring the local nonseparability along the propagation axis of vector beams. Employing higher-order Bessel vector beams, the longitudinal control over the local nonseparability is achieved through targeted amplitude modulation of constituent orthogonal polarization components within the main ring region. Experimental demonstrations of diverse longitudinal nonseparability profiles corroborate the efficacy and versatility of our approach, opening avenues for further exploration of the nonseparability manipulation in vector beams.

2.
J Am Chem Soc ; 146(19): 12883-12888, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38709642

RESUMO

Polyamides represent one class of materials that is important in modern society. Because of the numerous potential applications of polyamides in various fields, there is a high demand for new polyamide structures, which necessitates the development of new polymerization methods. Herein, we report a novel and efficient palladium-catalyzed hydroaminocarbonylative polymerization of dienes and diamines for the synthesis of cycloaliphatic polyamides. The method employs readily available starting materials, proceeds in an atom-economic manner, and creates a series of new functional polyamides in high yields and high molecular weights. In contrast with the traditional polyamides based on adipic acid, the cycloaliphatic polyamides have superior thermal resistance, higher glass-transition temperature, and better solubility in common organic solvents, thus probably featuring the merits of high-performance and good processability.

3.
Angew Chem Int Ed Engl ; : e202406226, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38618886

RESUMO

In contrast to the kinetically favored outward isomerization-hydrocarbonylation of alkenes, the disfavored inward isomerization-hydrocarbonylation of alkenes remains an important challenge. Herein, we have developed a novel and effective palladium-catalyzed inward isomerization-hydroaminocarbonylation of unactivated alkenes and aniline hydrochlorides for the formation of synthetically valuable α-aryl carboxylic amides in high yields and high site-selectivities. The high efficiency of the reaction is attributed to a relay catalysis strategy, in which the Markovnikov-favored [PdH]-PtBu3 catalyst is responsible for inward isomerization, while the [PdH]-Ruphos catalyst is responsible for hydroaminocarbonylation of the resulting conjugated aryl alkenes. The reaction exhibits highly functional group tolerance and provides a new method for formal carbonylation of remote C(sp3)-H bond.

4.
World J Gastroenterol ; 30(13): 1911-1925, 2024 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-38659485

RESUMO

BACKGROUND: Liuweiwuling Tablet (LWWL) is a Chinese patent medicine approved for the treatment of chronic inflammation caused by hepatitis B virus (HBV) infection. Previous studies have indicated an anti-HBV effect of LWWL, specifically in terms of antigen inhibition, but the underlying mechanism remains unclear. AIM: To investigate the potential mechanism of action of LWWL against HBV. METHODS: In vitro experiments utilized three HBV-replicating and three non-HBV-replicating cell lines. The in vivo experiment involved a hydrodynamic injection-mediated mouse model with HBV replication. Transcriptomics and metabolomics were used to investigate the underlying mechanisms of action of LWWL. RESULTS: In HepG2.1403F cells, LWWL (0.8 mg/mL) exhibited inhibitory effects on HBV DNA, hepatitis B surface antigen and pregenomic RNA (pgRNA) at rates of 51.36%, 24.74% and 50.74%, respectively. The inhibition rates of LWWL (0.8 mg/mL) on pgRNA/covalently closed circular DNA in HepG2.1403F, HepG2.2.15 and HepG2.A64 cells were 47.78%, 39.51% and 46.74%, respectively. Integration of transcriptomics and metabolomics showed that the anti-HBV effect of LWWL was primarily linked to pathways related to apoptosis (PI3K-AKT, CASP8-CASP3 and P53 pathways). Apoptosis flow analysis revealed that the apoptosis rate in the LWWL-treated group was significantly higher than in the control group (CG) among HBV-replicating cell lines, including HepG2.2.15 (2.92% ± 1.01% vs 6.68% ± 2.04%, P < 0.05), HepG2.A64 (4.89% ± 1.28% vs 8.52% ± 0.50%, P < 0.05) and HepG2.1403F (3.76% ± 1.40% vs 7.57% ± 1.35%, P < 0.05) (CG vs LWWL-treated group). However, there were no significant differences in apoptosis rates between the non-HBV-replicating HepG2 cells (5.04% ± 0.74% vs 5.51% ± 1.57%, P > 0.05), L02 cells (5.49% ± 0.80% vs 5.48% ± 1.01%, P > 0.05) and LX2 cells (6.29% ± 1.54% vs 6.29% ± 0.88%, P > 0.05). TUNEL staining revealed a significantly higher apoptosis rate in the LWWL-treated group than in the CG in the HBV-replicating mouse model, while no noticeable difference in apoptosis rates between the two groups was observed in the non-HBV-replicating mouse model. CONCLUSION: Preliminary results suggest that LWWL exerts a potent inhibitory effect on wild-type and drug-resistant HBV, potentially involving selective regulation of apoptosis. These findings offer novel insights into the anti-HBV activities of LWWL and present a novel mechanism for the development of anti-HBV medications.


Assuntos
Antivirais , Apoptose , DNA Viral , Medicamentos de Ervas Chinesas , Vírus da Hepatite B , Comprimidos , Replicação Viral , Apoptose/efeitos dos fármacos , Animais , Humanos , Vírus da Hepatite B/efeitos dos fármacos , Medicamentos de Ervas Chinesas/farmacologia , Camundongos , Células Hep G2 , Antivirais/farmacologia , Replicação Viral/efeitos dos fármacos , Modelos Animais de Doenças , Antígenos de Superfície da Hepatite B/metabolismo , Masculino , Hepatite B/tratamento farmacológico , Hepatite B/virologia , RNA Viral/metabolismo , Fígado/efeitos dos fármacos , Fígado/patologia , Fígado/virologia
5.
Front Aging Neurosci ; 16: 1381692, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38524118

RESUMO

Background and aims: Dementia imposes a heavy burden on society and families, therefore, effective drug treatments, exploring and preventing factors associated with dementia, are paramount. To provide reference points for the best frequency of physical exercise (physical exercise), we investigated the association between frequency of PE and cognition in Chinese old adults. Methods: 16,181 Chinese participants aged 65 years or older were included in this study. Associations between PE and cognition were estimated multivariate logistic and linear regression analyses. Associations were further investigated across dementia subtypes (Alzheimer dementia, vascular dementia, and other types of dementia). Subgroup analyses were performed in different age groups, in populations with and without stroke, and those with and without hypertension. Results: PE associated with dementia after adjusting for full covariates (OR: 0.5414, 95% CI: 0.4536-0.6491, p < 0.001). Exercise performed at ≥3 times/week associated with lower risk of dementia (OR: 0.4794-0.6619, all p value <0.001). PE was associated with improved cognition (ß: 12851, p < 0.001), and any PE frequency contributed to cognitive improvement (p values for exercise performed ≥1 time/week were <0.001). Similar conclusions were identified when we repeated analyses in different dementia subtypes and age groups. Subgroup analyses suggested that the cognition of individuals without hypertension also benefitted from exercising 1-2 times/week (OR: 0.6168, 95% CI: 0.4379-0.8668, p = 0.005). Conclusion: The best exercise frequency is exercising ≥3 times/week for individuals from different dementia subtypes and age groups. While for those without hypertension, PE at 1-2 times /week is also beneficial.

6.
Behav Sci (Basel) ; 14(3)2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38540536

RESUMO

Time-based prospective memory (TBPM) refers to the ability of an individual to successfully execute an expected plan in the future at a certain time point or after a definite period of time. This study investigated the potential developmental mechanism of school-age children's TBPM ability from the perspective of time monitoring. Experiment 1 used a between-subjects design of three ages (7, 9, 11) × two TBPM types (time point, time period) to investigate the trends and characteristics of two types of TBPM in children aged 7-11 years old. Experiment 2 used a between-subjects design of three ages (7, 9, 11) × two monitoring conditions (free monitoring, fixed monitoring) to investigate differences in two types of TBPM and monitoring behavior among school-age children under different monitoring conditions. These results showed that the age effect of TBPM was affected by the type of prospective memory (PM) and that time-point PM performance was significantly better than time-period PM performance among school-age children. These findings indicate that clear and definite external cues are helpful for school-age children in performing TBPM tasks. Moreover, there were significant differences found in the TBPM performance of school-age children under different time monitoring conditions. The performance of older children was significantly better than that of younger children. This indicates that older children can better allocate their attentional resources and use time monitoring strategies to improve their performance in PM tasks. Accordingly, this study showed that the TBPM ability of 7- to 11-year-old children is in continuous development and that the time monitoring behavior in the TBPM task is affected by task type and monitoring conditions.

7.
Arch Microbiol ; 206(4): 177, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38494532

RESUMO

Tuberculosis (TB), an infectious disease caused by Mycobacterium tuberculosis (Mtb) infection, has persisted as a major global public health threat for millennia. Until now, TB continues to challenge efforts aimed at controlling it, with drug resistance and latent infections being the two main factors hindering treatment efficacy. The scientific community is still striving to understand the underlying mechanisms behind Mtb's drug resistance and latent infection. DNA methylation, a critical epigenetic modification occurring throughout an individual's growth and development, has gained attention following advances in high-throughput sequencing technologies. Researchers have observed abnormal DNA methylation patterns in the host genome during Mtb infection. Given the escalating issue of drug-resistant Mtb, delving into the role of DNA methylation in TB's development is crucial. This review article explores DNA methylation's significance in human growth, development and disease, and its role in regulating Mtb's evolution and infection processes. Additionally, it discusses potential applications of DNA methylation research in tuberculosis.


Assuntos
Mycobacterium tuberculosis , Tuberculose , Humanos , Metilação de DNA , Antituberculosos , Tuberculose/tratamento farmacológico , Tuberculose/genética , Tuberculose/microbiologia , Mycobacterium tuberculosis/genética
8.
In Vitro Cell Dev Biol Anim ; 60(3): 287-299, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38485818

RESUMO

The study aimed to investigate the effect of ginsenoside Rg1 on intervertebral disc degeneration (IVDD) in rats and IL-1ß-induced nucleus pulposus (NP) cells, and explore its underlying mechanism. Forty IVDD rat models were divided into the IVDD group, low-dose (L-Rg1) group (intraperitoneal injection of 20 mg/kg/d ginsenoside Rg1), medium-dose (M-Rg1) group (intraperitoneal injection of 40 mg/kg/d ginsenoside Rg1), and high-dose (H-Rg1) group (intraperitoneal injection of 80 mg/kg/d ginsenoside Rg1). The pathological change was observed by HE and safranin O-fast green staining. The expression of IL-1ß, IL-6, TNF-α, MMP3, aggrecan, and collagen II was detected. The expression of NF-κB p65 in IVD tissues was detected. Rat NP cells were induced by IL-1ß to simulate IVDD environment and divided into the control group, IL-1ß group, and 20, 50, and 100 µmol/L Rg1 groups. The cell proliferation activity, the apoptosis, and the expression of IL-6, TNF-α, MMP3, aggrecan, collagen II, and NF-κB pathway-related protein were detected. In IVDD rats, ginsenoside Rg1 improved the pathology of IVD tissues; suppressed the expression of IL-1ß, IL-6, TNF-α, aggrecan, and collagen II; and inhibited the expression of p-p65/p65 and nuclear translocation of p65, to alleviate the IVDD progression. In the IL-1ß-induced NP cells, ginsenoside Rg1 also improved the cell proliferation and inhibited the apoptosis and the expression of IL-6, TNF-α, aggrecan, collagen II, p-p65/p65, and IκK in a dose-dependent manner. Ginsenoside Rg1 alleviated IVDD in rats and inhibited apoptosis, inflammatory response, and ECM degradation in IL-1ß-induced NP cells. And Rg1 may exert its effect via inhibiting the activation of NF-κB signaling pathway.


Assuntos
Ginsenosídeos , Degeneração do Disco Intervertebral , Disco Intervertebral , Núcleo Pulposo , Animais , Ratos , Agrecanas/genética , Apoptose , Colágeno/farmacologia , Inflamação/patologia , Interleucina-6/metabolismo , Disco Intervertebral/metabolismo , Disco Intervertebral/patologia , Degeneração do Disco Intervertebral/tratamento farmacológico , Degeneração do Disco Intervertebral/metabolismo , Degeneração do Disco Intervertebral/patologia , Metaloproteinase 3 da Matriz/metabolismo , NF-kappa B/metabolismo , Transdução de Sinais , Fator de Necrose Tumoral alfa/metabolismo
9.
J Am Chem Soc ; 146(12): 8260-8268, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38497725

RESUMO

We report the synthesis, crystal structure, and physical properties of a novel ternary compound, Th2Cu4As5. The material crystallizes in a tetragonal structure with lattice parameters a = 4.0639(3) Å and c = 24.8221(17) Å. Its structure can be described as an alternating stacking of fluorite-type Th2As2 layers with antifluorite-type double-layered Cu4As3 slabs. The measurement of electrical resistivity, magnetic susceptibility, and specific heat reveals that Th2Cu4As5 undergoes bulk superconducting transition at 4.2 K. Additionally, all these physical quantities exhibit anomalies at 48 K, accompanied by a sign change in the Hall coefficient, suggesting a charge-density-wave-like (CDW) phase transition. Drawing from both experimental data and band calculations, we propose that the superconducting and CDW-like phase transitions are, respectively, associated with the Cu4As3 slabs and the As plane in the Th2As2 layers.

10.
Food Res Int ; 181: 114094, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38448096

RESUMO

The detailed dynamics of small molecular nonvolatile chemical and bacterial diversities, as well as their relationship are still unclear in the manufacturing process of Keemun black tea (KMBT). Herein, mass spectrometry-based untargeted metabolomics, Feature-based Molecular Networking (FBMN) and bacterial DNA amplicon sequencing were used to investigate the dense temporal samples of the manufacturing process. For the first time, we reveal that the pyrogallol-type catechins are oxidized asynchronously before catechol-type catechins during the black tea processing. Rolling is the key procedure for forming the small molecular nonvolatile metabolite profile (SMNMetProf), increasing the metabolite richness, and then shaping the bacterial community structure in the KMBT manufacturing process, which decreases both molecular weight and molecular polarity of the small molecular nonvolatile metabolites. The SMNMetProf of black tea is formed by the endogenous enzymatic oxidation of tea leaves, rather than bacterial fermentation.


Assuntos
Camellia sinensis , Catequina , Chá , Comércio , DNA Bacteriano/genética
11.
Huan Jing Ke Xue ; 45(2): 768-779, 2024 Feb 08.
Artigo em Chinês | MEDLINE | ID: mdl-38471916

RESUMO

Relationships between land use and water quality of rivers and lakes vary spatially and temporally. These variations were analyzed using spatial analysis and mathematical statistical methods for the Suzhou Creek in Shanghai. Based on the data of water quality and land use in 2001, 2005, 2010, 2015, and 2020, five spatial scales (200, 500, 1 000, 2 000, and 5 000 m reach buffer) of the landscape pattern were extracted using correlation and redundancy analysis to explore the impact of land use composition and spatial pattern on water quality at different spatial and temporal scales. The results showed that: ① the water quality of Suzhou Creek has gradually improved in the past 20 years; other indicators were between Class II to Class IV in 2020 except TN, and TN was the main pollutant. ② The main land use type of the buffer zone was construction land, and the proportion of greenland and woodland showed a small growth trend. ③ The water quality was closely related to landscape pattern, showing temporal and spatial scale effects. On the time scale, indicators such as construction land, agricultural land, landscape dominance, aggregation, and diversity had significant correlations with various water quality parameters, and there was an inverse correlation in 2010 compared with that in other years for NH4+-N, TP, and TN. The landscape pattern in 2001 had the greatest explanation for water quality, with an explanation rate of 93.65%. The impact of greenland and woodland on water quality has begun to emerge in the past 10 years. ④ On the spatial scale, there were significant correlations between greenland and woodland, patch number, landscape shape index, diversity index, and water quality. There was a strong positive regulatory effect of greenland and woodland on NH4+-N, TP, and TN at the scale of 2 000 m. The patch number and landscape shape index had relatively strong regulatory effects on water quality on a larger spatial scale, whereas the Shannon diversity index had a better positive regulatory effect on water quality on a small scale. The landscape pattern within a buffer of 2 000 m had the highest interpretation degree for all factors, with an explanation rate of 68.47%. The study showed that rationally planning the proportion of greenland and woodland within the 2 000 m buffer zone and optimizing its landscape configuration is an important measure to purify the surface water quality of Suzhou Creek.

12.
Nat Commun ; 15(1): 2197, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38467628

RESUMO

The superconductivity in systems containing dispersionless (flat) bands is seemingly paradoxical, as traditional Bardeen-Cooper-Schrieffer theory requires an infinite enhancement of the carrier masses. However, the combination of flat and steep (dispersive) bands within the multiple band scenario might boost superconducting responses, potentially explaining high-temperature superconductivity in cuprates and metal hydrides. Here, we report on the magnetic penetration depths, the upper critical field, and the specific heat measurements, together with the first-principles calculations for the Mo5Si3-xPx superconducting family. The band structure features a flat band that gradually approaches the Fermi level as a function of phosphorus doping x, reaching the Fermi level at x ≃ 1.3. This leads to an abrupt change in nearly all superconducting quantities. The superfluid density data placed on the 'Uemura plot' results in two separated branches, thus indicating that the emergence of a flat band enhances correlations between conducting electrons.

13.
Chemistry ; 30(24): e202400377, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38403857

RESUMO

The atom-transfer radical addition (ATRA) reaction simultaneously forges carbon-carbon and carbon-halogen bonds. However, frequently-used photosensitizers such as precious transition metal complexes, or organic dyes have limitations in terms of their potential toxicity and recyclability. Three ß-ketoenamine-linked covalent organic frameworks (COFs) from 1,3,5-triformylphloroglucinol and 1,4-phenylenediamines with variable transient photocurrent and photocatalytic activity have been prepared. A COF bearing electron-deficient Cl atoms displayed the highest photocatalytic activity toward the ATRA reaction of polyhalogenated alkanes to give halogenated olefins under visible light at room temperature. This heterogeneous photocatalyst exhibited good functional group tolerance and could be recycled without significant loss of activity.

14.
Nitric Oxide ; 145: 33-40, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38382866

RESUMO

OBJECTIVE: Hydrogen sulfide (H2S) is associated with depressive-like behavior in rodents. We undertook cross-sectional and longitudinal analyses of plasma levels of H2S and its substrate homocysteine (Hcy) in depression and assessed the association of both parameters with psychopathology and cognitive function. METHODS: Forty-one patients suffering from depression (PSDs) and 48 healthy volunteers were recruited. PSDs were treated for 8 weeks. Analyzable data were collected from all participants for assessment of their psychopathology and cognitive function. Plasma was collected for determination of levels of H2S and Hcy, and data were correlated to determine their potential as plasma biomarkers. RESULTS: Cross-sectional analyses revealed PSDs to have a low plasma H2S level and high Hcy level. Longitudinal analyses revealed that 8 weeks of treatment reversed the changes in plasma levels of H2S and Hcy in PSDs. Plasma levels of H2S and Hcy were associated with psychopathology and cognitive function in depression. The area under the receiver operating characteristic curve (AUC) for a combination of plasma levels of H2S and Hcy and expression of the TNF gene (i.e., H2S-Hcy-TNF) was 0.848 for diagnosing depression and 0.977 for predicting the efficacy of antidepressant agents. CONCLUSION: Plasma levels of H2S and Hcy reflect changes in psychopathology and cognitive function in depression and H2S-Hcy-TNF has the potential to diagnose depression and predict the efficacy of antidepressant medications.


Assuntos
Sulfeto de Hidrogênio , Humanos , Sulfeto de Hidrogênio/metabolismo , Estudos Transversais , Homocisteína
15.
J Org Chem ; 89(6): 4098-4112, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38421813

RESUMO

A method for the selective construction of S-N/C(sp2)-S bonds using N-substituted O-thiocarbamates and indoles as substrates is reported. This protocol features good atom utilization, mild conditions, short reaction time, and wide substrate scope, which can provide a convenient path for the functionalization of indoles. In addition, the reaction could be scaled up on gram scale, showing potential application value in industry synthesis.

16.
Chem Asian J ; 19(7): e202400005, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38296810

RESUMO

A Schiff-base porous polymer has been impregnated with ruthenium trichloride for acceptor-free dehydrogenation coupling (ADC) of secondary alcohols with γ-amino- and 2-aminobenzyl alcohols to give pyridines and quinolines. This heterogenous catalyst exhibited high catalytic efficiency over repeated cycles with wide functional group tolerance.

17.
Mol Divers ; 2024 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-38183513

RESUMO

Thymidylate kinase (TMPK) of monkeypox virus (MPXV) has emerged as a promising target for potential therapeutics due to its significant role in pyrimidine metabolism. While smallpox drugs are advised for treating monkeypox, the European Medicine Agency has sanctioned Tecovirimat due to its potent nanomolar activity. Nonetheless, there is a need for monkeypox-specific therapeutic options. In this work, we employed docking-based virtual screening and molecular dynamics (MD) simulations to identify myxobacterial secondary metabolites as promising anti-viral natural compounds capable of inhibiting thymidylate kinase. The computational pharmacokinetics and manual curation of top-scoring compounds identified six lead compounds that were compared in terms of protein-ligand contacts and protein-essential dynamics. The study shows that among the six candidates, Aurachin A and the Soraphinol analogues such as Soraphinol A and Soraphinol C remain very stable compared to other compounds, enabling the active site integrity via a stable dynamics pattern. We also show that other compounds such as Phenoxan, Phenylnannolone C, and 8E-Aurafuron B remain unstable and have a negative impact on the active site integrity and may not be suitable binders for TMPK protein. Analyzing the Aurachin A and Soraphinol A binding, the established hydrogen bonds with Arg93 and the conserved hydrophobic interaction with Tyr101 are consistent with previous experimental interactions. Additionally, a deeper insight into the indole and the aromatic ring interaction through π-π stacking and π-cation interactions, as well as the background of Aurachin A and Soraphinol A as a bioactive compound, has significant implications not only for its potential as a promising drug but also for directing future drug discovery efforts targeting the TMPK protein.

18.
Sci Total Environ ; 915: 170037, 2024 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-38232856

RESUMO

Large missing sources of daytime atmospheric nitrous acid (HONO), a vital source of hydroxyl radicals (OH) through its photolysis, frequently exist in global coastal regions. In this study, ambient HONO and relevant species were measured at a coastal site in the Pearl River Delta (PRD), China, during October 2019. Relatively high concentrations (0.32 ± 0.19 ppbv) and daytime peaks at approximately 13:00 of HONO were observed, and HONO photolysis was found to be the dominant (55.5 %) source of the primary OH production. A budget analysis of HONO based on traditional sources suggested large unknown sources during the daytime (66.4 %), which had a significant correlation with the mass of coarse particles (PM2.5-10) and photolysis frequency (J(NO2)). When incorporating photolysis of the abundant nitrate measured in coarse particles with a reasonable enhancement factor relative to fine particles due to favorable aerosol conditions, the missing daytime sources of HONO could be fully compensated by coarse particles serving as the largest source at this coastal site. Our study revealed great potential of coarse particles as a strong daytime HONO source, which has been ignored before but can efficiently promote NOx recycling and thus significantly enhance atmospheric oxidation capacity.

19.
Adv Mater ; 36(10): e2300320, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37141008

RESUMO

Fungal pathogens have been designated by the World Health Organization as microbial threats of the highest priority for global health. It remains a major challenge to improve antifungal efficacy at the site of infection while avoiding off-target effects, fungal spreading, and drug tolerance. Here, a nanozyme-based microrobotic platform is developed that directs localized catalysis to the infection site with microscale precision to achieve targeted and rapid fungal killing. Using electromagnetic field frequency modulation and fine-scale spatiotemporal control, structured iron oxide nanozyme assemblies are formed that display tunable dynamic shape transformation and catalysis activation. The catalytic activity varies depending on the motion, velocity, and shape providing controllable reactive oxygen species (ROS) generation. Unexpectedly, nanozyme assemblies bind avidly to fungal (Candida albicans) surfaces to enable concentrated accumulation and targeted ROS-mediated killing in situ. By exploiting these tunable properties and selective binding to fungi, localized antifungal activity is achieved using in vivo-like cell spheroid and animal tissue infection models. Structured nanozyme assemblies are directed to Candida-infected sites using programmable algorithms to perform precisely guided spatial targeting and on-site catalysis resulting in fungal eradication within 10 min. This nanozyme-based microrobotics approach provides a uniquely effective and targeted therapeutic modality for pathogen elimination at the infection site.


Assuntos
Antifúngicos , Micoses , Animais , Antifúngicos/química , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Candida albicans/metabolismo , Modelos Animais
20.
Inorg Chem ; 63(1): 211-218, 2024 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-38153326

RESUMO

A quaternary compound, ThCr2Si2C, was synthesized by using the arc-melting technique. The compound adopts a tetragonal CeCr2Si2C-type crystal structure. The electronic resistivity and specific heat data exhibit metallic behavior, while the magnetic susceptibility displays a pronounced broad peak at around 370 K, indicating the antiferromagnetic phase transition. The first-principles calculations suggest A-type antiferromagnetic ordering of the Cr sublattice, which is confirmed by neutron diffraction experiments. By comparing the crystal structure of ThCr2Si2C with the isostructural Cr-based compounds, the magnetic state of Cr 3d orbital is discussed in terms of the band-filling effects and indirect spin exchange interaction.

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