Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.825
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Chem Soc Rev ; 2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-39212091

RESUMO

By engineering chemically identical but structurally distinct materials into intricate and sophisticated polytypic nanostructures, which often surpass their pure phase objects and even produce novel physical and chemical properties, exciting applications in the fields of photovoltaics, electronics and photocatalysis can be achieved. In recent decades, various methods have been developed for synthesizing a library of polytypic nanocrystals encompassing IV, III-V and II-VI polytypic semiconductors. The exceptional performances of polytypic metal chalcogenide nanocrystals have been observed, making them highly promising candidates for applications in photonics and electronics. However, achieving high-precision control over the morphology, composition, crystal structure, size, homojunctions, and periodicity of polytypic metal chalcogenide nanostructures remains a significant synthetic challenge. This review article offers a comprehensive overview of recent progress in the synthesis and control of polytypic metal chalcogenide nanocrystals using colloidal synthetic strategies. Starting from a concise introduction on the crystal structures of metal chalcogenides, the subsequent discussion delves into the colloidal synthesis of polytypic metal chalcogenide nanocrystals, followed by an in-depth exploration of the key factors governing polytypic structure construction. Subsequently, we provide comprehensive insights into the physical properties of polytypic metal chalcogenide nanocrystals, which exhibit strong correlations with their applications. Thereafter, we emphasize the significance of polytypic nanostructures in various applications, such as photovoltaics, photocatalysis, transistors, thermoelectrics, stress sensors, and the electrocatalytic hydrogen evolution. Finally, we present a summary of the recent advancements in this research field and provide insightful perspectives on the forthcoming challenges, opportunities, and future research directions.

2.
Nano Lett ; 24(3): 881-889, 2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38198246

RESUMO

Cellulose nanofiber (CNF) possesses excellent intrinsic properties, and many CNF-based high-performance structural and functional materials have been developed recently. However, the coordination of the mechanical properties and functionality is still a considerable challenge. Here, a CNF-based structural material is developed by a bioinspired gradient structure design using hollow magnetite nanoparticles and the phosphorylation-modified CNF as building blocks, which simultaneously achieves a superior mechanical performance and electromagnetic wave absorption (EMA) ability. Benefiting from the gradient design, the flexural strength of the structural material reached ∼205 MPa. Meanwhile, gradient design improves impedance matching, contributing to the high EMA ability (-59.5 dB) and wide effective absorption width (5.20 GHz). Besides, a low coefficient of thermal expansion and stable storage modulus was demonstrated as the temperature changes. The excellent mechanical, thermal, and EMA performance exhibited great potential for application in stealth equipment and electromagnetic interference protecting electronic packaging materials.

3.
Nano Lett ; 24(14): 4082-4090, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38526914

RESUMO

The generally nonpolar SrTiO3 has attracted more attention recently because of its possibly induced novel polar states and related paraelectric-ferroelectric phase transitions. By using controlled pulsed laser deposition, high-quality, ultrathin, and strained SrTiO3 layers were obtained. Here, transmission electron microscopy and theoretical simulations have unveiled highly polar states in SrTiO3 films even down to one unit cell at room temperature, which were stabilized in the PbTiO3/SrTiO3/PbTiO3 sandwich structures by in-plane tensile strain and interfacial coupling, as evidenced by large tetragonality (∼1.05), notable polar ion displacement (0.019 nm), and thus ultrahigh spontaneous polarization (up to ∼50 µC/cm2). These values are nearly comparable to those of the strong ferroelectrics as the PbZrxTi1-xO3 family. Our findings provide an effective and practical approach for integrating large strain states into oxide films and inducing polarization in nonpolar materials, which may broaden the functionality of nonpolar oxides and pave the way for the discovery of new electronic materials.

4.
J Am Chem Soc ; 146(29): 19998-20008, 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-38865282

RESUMO

As the dimensionality of materials generally affects their characteristics, thin films composed of low-dimensional nanomaterials, such as nanowires (NWs) or nanoplates, are of great importance in modern engineering. Among various bottom-up film fabrication strategies, interfacial assembly of nanoscale building blocks holds great promise in constructing large-scale aligned thin films, leading to emergent or enhanced collective properties compared to individual building blocks. As for 1D nanostructures, the interfacial self-assembly causes the morphology orientation, effectively achieving anisotropic electrical, thermal, and optical conduction. However, issues such as defects between each nanoscale building block, crystal orientation, and homogeneity constrain the application of ordered films. The precise control of transdimensional synthesis and the formation mechanism from 1D to 2D are rarely reported. To meet this gap, we introduce an interfacial-assembly-induced interfacial synthesis strategy and successfully synthesize quasi-2D nanofilms via the oriented attachment of 1D NWs on the liquid interface. Theoretical sampling and simulation show that NWs on the liquid interface maintain their lowest interaction energy for the ordered crystal plane (110) orientation and then rearrange and attach to the quasi-2D nanofilm. This quasi-2D nanofilm shows enhanced electric conductivity and unique optical properties compared with its corresponding 1D geometry materials. Uncovering these growth pathways of the 1D-to-2D transition provides opportunities for future material design and synthesis at the interface.

5.
Int J Cancer ; 154(12): 2075-2089, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38367273

RESUMO

Females with existing high-risk HPV (HR-HPV) infections remain at risk of subsequent multiple or recurrent infections, on which benefit from HPV vaccines was under-reported. We pooled individual-level data from four large-scale, RCTs of AS04-HPV-16/18 vaccine to evaluate efficacy and immunogenicity in females DNA-positive to any HR-HPV types at first vaccination. Females receiving the AS04-HPV-16/18 vaccine in the original RCTs constituted the vaccine group in the present study, while those unvaccinated served as the control group. Vaccine efficacy (VE) against new infections and associated cervical intraepithelial neoplasia (CIN) 2+ in females DNA-negative to the considered HR-HPV type but positive to any other HR-HPV types, VE against reinfections in females DNA-positive to the considered HR-HPV type but cleared naturally during later follow-up, and levels of anti-HPV-16/18 IgG were assessed. Our final analyses included 5137 females (vaccine group = 2532, control group = 2605). The median follow-up time was 47.88 months (IQR: 45.72-50.04). For the prevention of precancerous lesions related to the non-infected HR-HPV types at baseline, VE against HPV-16/18 related CIN 2+ was 82.70% (95% CI: 63.70-93.00%). For the prevention of reinfections related to the infected HR-HPV types following natural clearance, VE against HPV-16/18 12MPI was non-significant (p > .05), albeit robust immunity persisted for at least 48 months. Females with existing HR-HPV infections at first vaccination still benefit from vaccination in preventing precancers related to the non-infected types at baseline. VE against reinfections related to the infected types following natural clearance remains to be further investigated.


Assuntos
Infecções por Papillomavirus , Vacinas contra Papillomavirus , Displasia do Colo do Útero , Neoplasias do Colo do Útero , Feminino , Humanos , Papillomavirus Humano 16 , Vacinas contra Papillomavirus/uso terapêutico , Reinfecção/complicações , Papillomavirus Humano 18 , Vacinação , DNA
6.
J Neuroinflammation ; 21(1): 123, 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38725082

RESUMO

BACKGROUND: Hepatic encephalopathy (HE) is closely associated with inflammatory responses. However, as a crucial regulator of the immune and inflammatory responses, the role of leucine-rich repeat kinase 2 (LRRK2) in the pathogenesis of HE remains unraveled. Herein, we investigated this issue in thioacetamide (TAA)-induced HE following acute liver failure (ALF). METHODS: TAA-induced HE mouse models of LRRK2 wild type (WT), LRRK2 G2019S mutation (Lrrk2G2019S) and LRRK2 knockout (Lrrk2-/-) were established. A battery of neurobehavioral experiments was conducted. The biochemical indexes and pro-inflammatory cytokines were detected. The prefrontal cortex (PFC), striatum (STR), hippocampus (HIP), and liver were examined by pathology and electron microscopy. The changes of autophagy-lysosomal pathway and activity of critical Rab GTPases were analyzed. RESULTS: The Lrrk2-/--HE model reported a significantly lower survival rate than the other two models (24% vs. 48%, respectively, p < 0.05), with no difference found between the WT-HE and Lrrk2G2019S-HE groups. Compared with the other groups, after the TAA injection, the Lrrk2-/- group displayed a significant increase in ammonium and pro-inflammatory cytokines, aggravated hepatic inflammation/necrosis, decreased autophagy, and abnormal phosphorylation of lysosomal Rab10. All three models reported microglial activation, neuronal loss, disordered vesicle transmission, and damaged myelin structure. The Lrrk2-/--HE mice presented no severer neuronal injury than the other genotypes. CONCLUSIONS: LRRK2 deficiency may exacerbate TAA-induced ALF and HE in mice, in which inflammatory response is evident in the brain and aggravated in the liver. These novel findings indicate a need of sufficient clinical awareness of the adverse effects of LRRK2 inhibitors on the liver.


Assuntos
Encefalopatia Hepática , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina , Falência Hepática Aguda , Camundongos Knockout , Tioacetamida , Animais , Camundongos , Encefalopatia Hepática/patologia , Encefalopatia Hepática/genética , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/genética , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/metabolismo , Falência Hepática Aguda/induzido quimicamente , Falência Hepática Aguda/patologia , Falência Hepática Aguda/genética , Camundongos Endogâmicos C57BL , Tioacetamida/toxicidade
7.
Small ; 20(16): e2306914, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38041488

RESUMO

Electrocatalysts with high activity and durability for acidic oxygen evolution reaction (OER) play a crucial role in achieving cost-effective hydrogen production via proton exchange membrane water electrolysis. A novel electrocatalyst, Te-doped RuO2 (Te-RuO2) nanotubes, synthesized using a template-directed process, which significantly enhances the OER performance in acidic media is reported. The Te-RuO2 nanotubes exhibit remarkable OER activity in acidic media, requiring an overpotential of only 171 mV to achieve an anodic current density of 10 mA cm-2. Furthermore, they maintain stable chronopotentiometric performance under 10 mA cm-2 in acidic media for up to 50 h. Based on the experimental results and density functional calculations, this significant improvement in OER performance to the synergistic effect of large specific surface area and modulated electronic structure resulting from the doping of Te cations is attributed.

8.
Small ; : e2404452, 2024 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-39248686

RESUMO

Aqueous rechargeable lithium-ion batteries (ARLIBs) are extensively researched due to their inherent safety, typical affordability, and potential high energy density. However, fabricating ARLIBs with both high energy density and power performance remains challenging. Herein, based on cyanoethyl-modified bacterial cellulose nanofibers (CBCNs), a multifunctional fast ion transport framework is developed to construct the flexible free-standing ARLIBs with high areal loading and excellent rate performance. Benefiting from the unique merits of CBCNs, such as ultra-high aspect ratio, excellent toughness, superior adhesion, good lithiophilicity and ideal stability, the flexible free-standing and highly robust electrodes are fabricated and exhibit a long-term stable cycling of 1200 cycles with a high specific capacity of 117 mAh∙g-1 at 15 C. Remarkably, the corresponding full cell with the free-standing high mass loading (45.5 mg∙cm-2) electrodes under the condition of ultra-low addition of battery binder demonstrates a cycle lifespan of over 1000 cycles with a specific capacity of 120 mAh∙g-1 and a capacity decay as low as 0.03% per cycle, which is far superior to those of almost all previous reports. This work provides a strategy for constructing ARLIBs with high energy density and power performance by introducing a unique fast ion transport nanofiber framework.

9.
Small ; : e2401159, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38716681

RESUMO

Defects can introduce atomic structural modulation and tailor performance of materials. Herein, it demonstrates that semiconductor WO3 with inert electrocatalytic behavior can be activated through defect-induced tensile strains. Structural characterizations reveal that when simply treated in Ar/H2 atmosphere, oxygen vacancies will generate in WO3 and cause defective structures. Stacking faults are found in defects, thus modulating electronic structure and transforming electrocatalytic-inert WO3 into highly active electrocatalysts. Density functional theory (DFT) calculations are performed to calculate *H adsorption energies on various WOx surfaces, revealing the oxygen vacancy composition and strain predicted to optimize the catalytic activity of hydrogen evolution reaction (HER). Such defective tungsten oxides can be integrated into commercial proton exchange membrane (PEM) electrolyser with comparable performance toward Pt-based PEM. This work demonstrates defective metal oxides as promising non-noble metal catalysts for commercial PEM green-hydrogen generation.

10.
J Antimicrob Chemother ; 79(1): 128-133, 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-37991189

RESUMO

OBJECTIVES: We explored the epidemiological and molecular characteristics of Candida parapsilosis sensu stricto isolates in China, and their mechanisms of azole resistance. METHODS: Azole susceptibilities of 2318 non-duplicate isolates were determined using CLSI broth microdilution. Isolates were genotyped by a microsatellite typing method. Molecular resistance mechanisms were also studied and functionally validated by CRISPR/Cas9-based genetic alterations. RESULTS: Fluconazole resistance occurred in 2.4% (n = 56) of isolates, and these isolates showed a higher frequency of distribution in ICU inpatients compared with susceptible isolates (48.2%, n = 27/56 versus 27.8%, 613/2208; P = 0.019). Microsatellite-genotyping analysis yielded 29 genotypes among 56 fluconazole-resistant isolates, of which 10 genotypes, including 37 isolates, belonged to clusters, persisting and transmitting in Chinese hospitals for 1-29 months. Clusters harbouring Erg11Y132F (5/10; 50%) were predominant in China. Among these, the second most dominant cluster MT07, including seven isolates, characteristically harbouring Erg11Y132F and Mrr1Q625K, lent its carriage to being one of the strongest associations with cross-resistance and high MICs of fluconazole (>256 mg/L) and voriconazole (2-8 mg/L), causing transmission across two hospitals. Among mutations tested, Mrr1Q625K led to the highest-level increase of fluconazole MIC (32-fold), while mutations located within or near the predicted transcription factor domain of Tac1 (D440Y, T492M and L518F) conferred cross-resistance to azoles. CONCLUSIONS: This study is the first Chinese report of persistence and transmissions of multiple fluconazole-resistant C. parapsilosis sensu stricto clones harbouring Erg11Y132F, and the first demonstration of the mutations Erg11G307A, Mrr1Q625K, Tac1L263S, Tac1D440Y and Tac1T492M as conferring resistance to azoles.


Assuntos
Candida parapsilosis , Fluconazol , Fluconazol/farmacologia , Candida parapsilosis/genética , Antifúngicos/farmacologia , Azóis/farmacologia , China/epidemiologia , Testes de Sensibilidade Microbiana , Farmacorresistência Fúngica/genética
11.
BMC Microbiol ; 24(1): 309, 2024 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-39174950

RESUMO

BACKGROUND: Klebsiella pneumoniae (KP) is the second most prevalent Gram-negative bacterium causing bloodstream infections (BSIs). In recent years, the management of BSIs caused by KP has become increasingly complex due to the emergence of carbapenem-resistant Klebsiella pneumoniae (CRKP). Although numerous studies have explored the risk factors for the development of CRKP-BSIs, the mortality of patients with KP-BSIs, and the molecular epidemiological characteristics of CRKP, the variability in data across different populations, countries, and hospitals has led to inconsistent conclusions. In this single-center retrospective observational study, we utilized logistic regression analyses to identify independent risk factors for CRKP-BSIs and factors associated with mortality in KP-BSI patients. Furthermore, a risk factor-based prediction model was developed. CRKP isolates underwent whole-genome sequencing (WGS), followed by an evaluation of microbiological characteristics, including antimicrobial resistance and virulence genes, as well as epidemiological characteristics and phylogenetic analysis. RESULTS: Our study included a total of 134 patients with KP-BSIs, comprising 50 individuals infected with CRKP and 84 with carbapenem-susceptible Klebsiella pneumoniae (CSKP). The independent risk factors for CRKP-BSIs were identified as gastric catheterization (OR = 9.143; CI = 1.357-61.618; P = 0.023), prior ICU hospitalization (OR = 4.642; CI = 1.312-16.422; P = 0.017), and detection of CRKP in non-blood sites (OR = 8.112; CI = 2.130-30.894; P = 0.002). Multivariate analysis revealed that microbiologic eradication after 6 days (OR = 3.569; CI = 1.119-11.387; P = 0.032), high Pitt bacteremia score (OR = 1.609; CI = 1.226-2.111; P = 0.001), and inappropriate empirical treatment after BSIs (OR = 6.756; CI = 1.922-23.753; P = 0.003) were independent risk factors for the 28-day mortality in KP-BSIs. The prediction model confirmed that microbiologic eradication after 6.5 days and a Pitt bacteremia score of 4.5 or higher were significant predictors of the 28-day mortality. Bioinformatics analysis identified ST11 as the predominant CRKP sequence type, with blaKPC-2 as the most prevalent gene variant. CRKP stains carried multiple plasmid-mediated resistance genes along with some virulence genes. Phylogenetic analysis indicated the presence of nosocomial transmission of ST11 CRKP within the ICU. CONCLUSIONS: The analysis of risk factors for developing CRKP-BSIs and the association between KP-BSIs and 28-day mortality, along with the development of a risk factor-based prediction model and the characterization of CRKP strains, enhances clinicians' understanding of the pathogens responsible for BSIs. This understanding may help in the timely administration of antibiotic therapy for patients with suspected KP-BSIs, potentially improving outcomes.


Assuntos
Antibacterianos , Bacteriemia , Carbapenêmicos , Infecções por Klebsiella , Klebsiella pneumoniae , Humanos , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/isolamento & purificação , Estudos Retrospectivos , Infecções por Klebsiella/microbiologia , Infecções por Klebsiella/epidemiologia , Infecções por Klebsiella/mortalidade , Infecções por Klebsiella/tratamento farmacológico , Fatores de Risco , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Bacteriemia/microbiologia , Bacteriemia/mortalidade , Bacteriemia/epidemiologia , Bacteriemia/tratamento farmacológico , Antibacterianos/farmacologia , Carbapenêmicos/farmacologia , Filogenia , Testes de Sensibilidade Microbiana , Sequenciamento Completo do Genoma , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Enterobacteriáceas Resistentes a Carbapenêmicos/efeitos dos fármacos , Enterobacteriáceas Resistentes a Carbapenêmicos/isolamento & purificação , Fatores de Virulência/genética , Idoso de 80 Anos ou mais , Adulto
12.
Chem Res Toxicol ; 37(8): 1382-1393, 2024 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-39075630

RESUMO

Understanding the potential carcinogenic potency of nitrosamines is necessary to setting acceptable intake limits. Nitrosamines and the components that can form them are commonly present in food, water, cosmetics, and tobacco. The recent observation of nitrosamines in pharmaceuticals highlighted the need for effective methods to determine acceptable intake limits. Herein, we describe two computational models that utilize properties based upon quantum mechanical calculations in conjunction with mechanistic insights and established data to determine the carcinogenic potency of a variety of common nitrosamines. These models can be applied to experimentally untested nitrosamines to aid in the establishment of acceptable intake limits.


Assuntos
Carcinógenos , Nitrosaminas , Nitrosaminas/química , Carcinógenos/química , Carcinógenos/toxicidade , Cinética , Humanos , Testes de Carcinogenicidade , Teoria Quântica
13.
Lupus ; 33(4): 357-364, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38314781

RESUMO

OBJECTIVE: To investigate characteristics associated with different COVID-19 outcomes of people with systemic lupus erythematosus (SLE) and COVID-19 during the second pandemic wave of COVID-19 in China. METHODS: In this retrospective study, people with SLE and COVID-19 who visited the First Affiliated Hospital of Nanchang University from December 2022 and February 2023 were subjected to this study. The three possible outcomes were listed in order of ordinal severity: (1) not hospitalized, (2) hospitalized but not receiving oxygenation, and (3) hospitalized with any ventilation or oxygenation. A multivariable ordinal logistic regression model was built to examine the association between COVID-19 severity and demographic traits, medications, comorbidities, and disease activity. Furthermore, among the 301 SLE patients included in our study, only two patients experienced mortality. In order to maintain statistical rigor, we have included these two deceased patients in the outcome measure of hospitalized with any ventilation or oxygenation. RESULTS: A total of 301 patients with SLE were enrolled in this study. The multivariate ordinal logistic regression analyses indicated that high SLE disease activity (vs remission; OR 39.04, 95% CI 3.08 to 494.44, p = .005) was associated with more severe outcomes. Three doses of COVID-19 vaccination (OR 0.19, 95% CI 0.07 to 0.51, p = .001), glucocorticoids dose (1-5 mg/day 0.14, 0.03 to 0.73, p = .020, and 6-9 mg/day 0.12, 0.02 to 0.61, p = .010), and more intensive immunosuppression drugs (0.34, 0.12 to 0.97, p = .044) were associated with better outcomes. In age-adjusted and sex-adjusted models, telitacicept (6.66, 1.35 to 32.86, p = .020) and rituximab (7.81, 1.87 to 32.66, p = .005) were associated with more severe outcomes. Hydroxychloroquine (0.47, 0.25 to 0.88, p = .018) was associated with favorable outcomes. CONCLUSION: Different COVID-19 outcomes in people with SLE are mostly driven by COVID-19 vaccination, medications, and activity SLE. More importantly, three doses of COVID-19 vaccination may be associated with better outcomes.


Assuntos
COVID-19 , Lúpus Eritematoso Sistêmico , Humanos , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Lúpus Eritematoso Sistêmico/epidemiologia , Lúpus Eritematoso Sistêmico/complicações , Estudos Retrospectivos , Pandemias , Vacinas contra COVID-19 , COVID-19/epidemiologia , COVID-19/complicações
14.
J Pharmacol Sci ; 154(4): 225-235, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38485340

RESUMO

In this study, we investigated the regulatory mechanisms underlying the effects of LPS tolerance on the inflammatory homeostasis of immune cells. LPS priming-induced immune tolerance downregulated cyclooxygenase-2, and lowered the production of prostaglandin-E2 in microglial cells. In addition, LPS tolerance downregulated the expression of suppressor of cytokine signaling 3, and inducible nitric oxide synthase/nitric oxide; suppressed the LPS-mediated induction of tumor necrosis factor-α, interleukin (IL)-6, and IL-1; and reduced reactive oxygen species production in microglial cells. LPS stimulation increased the levels of the adaptive response-related proteins heme oxygenase-1 and superoxide dismutase 2, and the levels of heme oxygenase-1 (HO-1) enhanced after LPS priming. Systemic administration of low-dose LPS (0.5 mg/kg) to mice for 4 consecutive days attenuated high-dose LPS (5 mg/kg)-induced inflammatory response, microglial activation, and proinflammatory cytokine expression. Moreover, repeated exposure to low-dose LPS suppressed the recruitment of peripheral monocytes or macrophages to brain regions and downregulated the expression of proinflammatory cytokines. Notably, LPS-induced social avoidance behaviors in mice were mitigated by immune tolerance. In conclusion, immune tolerance may reduce proinflammatory cytokine expression and reactive oxygen species production. Our findings provide insights into the effects of endotoxin tolerance on innate immune cells and social behaviors.


Assuntos
Heme Oxigenase-1 , Microglia , Animais , Camundongos , Heme Oxigenase-1/metabolismo , Microglia/metabolismo , Lipopolissacarídeos/farmacologia , NF-kappa B/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Aprendizagem da Esquiva , Citocinas/metabolismo , Interleucina-6/metabolismo , Comportamento Social , Tolerância Imunológica , Óxido Nítrico Sintase Tipo II/metabolismo , Óxido Nítrico/metabolismo
15.
Exp Cell Res ; 422(1): 113440, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36481206

RESUMO

The limited cardiomyocyte proliferation is insufficient for repair of the myocardium. Therefore, activating cardiomyocyte proliferation might be a reasonable option for myocardial regeneration. Here, we investigated effect of retinoic acid (RA) on inducing adult cardiomyocyte proliferation and assessed efficacy of self-assembling peptide (SAP)-released RA in activating regeneration of the infarcted myocardium. Effect of RA on inducing cardiomyocyte proliferation was examined with the isolated cardiomyocytes. Expression of the cell cycle-associated genes and paracrine factors in the infarcted myocardium was examined at one week after treatment with SAP-carried RA. Cardiomyocyte proliferation, myocardial regeneration and improvement of cardiac function were assessed at four weeks after treatment. In the adult rat myocardium, expression of RA synthetase gene Raldh2 and RA concentration were decreased significantly. After treatment with RA, the proliferated cardiomyocytes were increased. The formulated SAP could sustainedly release RA. After treatment with SAP-carried RA, expression of the pro-proliferative genes in cell cycle and paracrine factors in the infarcted myocardium were up-regulated. Myocardial regeneration was enhanced, and cardiac function was improved significantly. These results demonstrate that RA can induce adult cardiomyocytes to proliferate effectively. The sustained release of RA with SAP is a promise strategy to enhance repair of the infarcted myocardium.


Assuntos
Infarto do Miocárdio , Miócitos Cardíacos , Ratos , Animais , Miócitos Cardíacos/metabolismo , Infarto do Miocárdio/metabolismo , Tretinoína/farmacologia , Tretinoína/metabolismo , Miocárdio/metabolismo , Peptídeos/farmacologia , Peptídeos/metabolismo , Proliferação de Células
16.
Plant Cell Rep ; 43(5): 119, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38632145

RESUMO

KEY MESSAGE: Mutants lacking functional HYD2 homoeologs showed improved seedling growth, but comparable or increased susceptibility to salt stress in tillering plants, suggesting a developmentally restricted role of HYD2 in salt response. Salinity stress threatens global food security by reducing the yield of staple crops such as wheat (Triticum ssp.). Understanding how wheat responds to salinity stress is crucial for developing climate resilient varieties. In this study, we examined the interplay between carotenoid metabolism and the response to salt (NaCl) stress, a specific form of salinity stress, in tetraploid wheat plants with mutations in carotenoid ß-hydroxylase 1 (HYD1) and HYD2. Our investigation encompassed both the vulnerable seedling stage and the more developed tillering stage of wheat plant growth. Mutant combinations lacking functional HYD2 homoeologs, including hyd-A2 hyd-B2, hyd-A1 hyd-A2 hyd-B2, hyd-B1 hyd-A2 hyd-B2, and hyd-A1 hyd-B1 hyd-A2 hyd-B2, had longer first true leaves and slightly enhanced root growth during germination under salt stress compared to the segregate wild-type (control) plants. Interestingly, these mutant seedlings also showed decreased levels of neoxanthin and violaxanthin (xanthophylls derived from ß-carotene) and an increase in ß-carotene in roots. However, tillering hyd mutant and segregate wild-type plants generally did not differ in their height, tiller count, and biomass production under acute or prolonged salt stress, except for decreases in these parameters observed in the hyd-A1 hyd-B1 hyd-A2 hyd-B2 mutant that indicate its heightened susceptibility to salt stress. Taken together, these findings suggest a significant, yet developmentally restricted role of HYD2 homoeologs in salt-stress response in tetraploid wheat. They also show that hyd-A2 hyd-B2 mutant plants, previously demonstrated for possessing enriched nutritional (ß-carotene) content, maintain an unimpaired ability to withstand salt stress.


Assuntos
Estresse Salino , Plântula , Triticum , beta Caroteno , beta Caroteno/metabolismo , Carotenoides/metabolismo , Salinidade , Estresse Salino/genética , Plântula/metabolismo , Tetraploidia , Triticum/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas
17.
Retina ; 2024 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-39121508

RESUMO

PURPOSE: Determine whether intravitreal injection of bevacizumab (IVB) exerts long-term effects on neurodevelopmental outcomes in children with retinopathy of prematurity (ROP) when reaching the age of 8 years. METHODS: We enrolled 277 children. Patients were stratified into the groups full-term, preterm without ROP, ROP without treatment, or ROP with treatment, based on gestational age (GA) and ROP status. Children under GA of 37 weeks were considered premature. Patients' cognitive outcomes were evaluated using Full-Scale Intelligence Quotient (FIQ) (full score and percentile) generated by the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) every 1 to 2 years. RESULTS: At the mean age of 7.8 years, ROP without and with treatment groups demonstrated lower FIQ scores and percentiles, compared with full-term and premature groups (both p<0.05). FIQ scores and percentiles didn't significantly differ between patients who received different treatments for ROP (full score p=0.19; percentile p=0.37). After adjusting for GA, LogMAR best corrected visual acuity (BCVA) was negatively associated with FIQ scores (p=0.0008) and percentiles (p=0.0002). CONCLUSIONS: At the mean age of 8 years, patients with ROP undergoing IVB didn't exhibit worse cognitive outcomes than those who underwent laser photocoagulation or both treatments. GA and BCVA correlated with cognitive development in children.

18.
Proc Natl Acad Sci U S A ; 118(12)2021 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-33737391

RESUMO

Kleine-Levin syndrome (KLS) is a rare disorder characterized by severe episodic hypersomnia, with cognitive impairment accompanied by apathy or disinhibition. Pathophysiology is unknown, although imaging studies indicate decreased activity in hypothalamic/thalamic areas during episodes. Familial occurrence is increased, and risk is associated with reports of a difficult birth. We conducted a worldwide case-control genome-wide association study in 673 KLS cases collected over 14 y, and ethnically matched 15,341 control individuals. We found a strong genome-wide significant association (rs71947865, Odds Ratio [OR] = 1.48, P = 8.6 × 10-9) within the 3'region of TRANK1 gene locus, previously associated with bipolar disorder and schizophrenia. Strikingly, KLS cases with rs71947865 variant had significantly increased reports of a difficult birth. As perinatal outcomes have dramatically improved over the last 40 y, we further stratified our sample by birth years and found that recent cases had a significantly reduced rs71947865 association. While the rs71947865 association did not replicate in the entire follow-up sample of 171 KLS cases, rs71947865 was significantly associated with KLS in the subset follow-up sample of 59 KLS cases who reported birth difficulties (OR = 1.54, P = 0.01). Genetic liability of KLS as explained by polygenic risk scores was increased (pseudo R2 = 0.15; P < 2.0 × 10-22 at P = 0.5 threshold) in the follow-up sample. Pathway analysis of genetic associations identified enrichment of circadian regulation pathway genes in KLS cases. Our results suggest links between KLS, circadian regulation, and bipolar disorder, and indicate that the TRANK1 polymorphisms in conjunction with reported birth difficulties may predispose to KLS.


Assuntos
Citocinas/genética , Suscetibilidade a Doenças , Variação Genética , Síndrome de Kleine-Levin/complicações , Síndrome de Kleine-Levin/genética , Complicações do Trabalho de Parto/epidemiologia , Complicações do Trabalho de Parto/etiologia , Transtorno Bipolar/etiologia , Distúrbios do Sono por Sonolência Excessiva/etiologia , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Síndrome de Kleine-Levin/epidemiologia , Masculino , Razão de Chances , Polimorfismo Genético , Gravidez , Medição de Risco , Fatores de Risco
19.
Ecotoxicol Environ Saf ; 283: 116786, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-39083869

RESUMO

Cd ions are absorbed and transported from the soil by crop roots, which are the first organ to be exposed to Cd. This results in an increase in cadmium ions in crops, significantly affecting crop growth and yield. Exogenous melatonin (MT) can help reduce cadmium (Cd) stress in cotton, but the specific contribution of roots to this process remains unclear. In order to address this knowledge gap, an in-situ root phenotyping study was conducted to investigate the the phenotype and lifespan of roots under cadmium stress (Cd) and melatonin treatment (Cd + MT). The results showed that MT alleviated the decreases in plant height, leaf area, SPAD value, stem diameter, stomatal conductance and net photosynthetic rate under Cd stress, which further promoted the biomass accumulation in various cotton organs. What is more, the Cd + MT treatment increased root volume, surface area, and length under Cd stress by 25.63 %, 10.58 %, and 21.89 %, respectively, compared with Cd treatment. Interestingly, compared to Cd treatment, Cd + MT treatment also significantly extended the lifespan of roots and root hairs by 6.68 days and 2.18 days, respectively. In addition, Cd + MT treatment reduced the transport of Cd from roots to shoots, particularly to bolls, and decreased the Cd bioconcentration factor in bolls by 61.17 %, compared to Cd treatment. In conclusion, these findings show that applying MT externally helps reduce Cd stress by delaying root senescence, promoting root development and regulating Cd transport. This method can be an effective approach to managing Cd stress in cotton.


Assuntos
Cádmio , Gossypium , Melatonina , Raízes de Plantas , Poluentes do Solo , Gossypium/efeitos dos fármacos , Gossypium/crescimento & desenvolvimento , Melatonina/farmacologia , Cádmio/toxicidade , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Poluentes do Solo/toxicidade , Transporte Biológico/efeitos dos fármacos
20.
Chem Biodivers ; 21(5): e202302111, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38453650

RESUMO

Phytochemical studies on 95 % ethanol extract of the heartwood of Solanum verbascifolium L. resulted in the isolation of one new amide derivative (1), and 21 known phenylpropanoids compounds. The structures were characterized by spectral analysis and high-resolution mass spectrometric analysis. The anti-inflammatory activity of amide compounds 1-4 and 6-9 by investigating their impact on the release of nitric oxide (NO) in MH-S cells. Our findings unveiled significant inhibitory effects on NO secretion. Compound 1 exhibited robust dose-dependent suppression, with pronounced inhibition observed at both 20 µM (P<0.01) and 40 µM (P<0.01). Furthermore, compound 9 demonstrated noteworthy inhibitory effects at 40 µM (P<0.01). Similarly, compounds 3 and 4 displayed substantial inhibition of NO secretion at the same concentration, although the significance level was slightly lower (P<0.05). It is expected that there is a substantial association between the anti-inflammatory activities of amides and their targets, specifically PTGS2, by combining network pharmacology and molecular docking techniques. This discovery emphasizes amides' potential as an interesting subject for additional study in the realm of anti-inflammatory medications.


Assuntos
Anti-Inflamatórios , Simulação de Acoplamento Molecular , Óxido Nítrico , Solanum , Solanum/química , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/metabolismo , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Anti-Inflamatórios/isolamento & purificação , Ciclo-Oxigenase 2/metabolismo , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Extratos Vegetais/isolamento & purificação , Farmacologia em Rede , Amidas/química , Amidas/farmacologia , Amidas/isolamento & purificação , Camundongos , Relação Dose-Resposta a Droga , Estrutura Molecular , Relação Estrutura-Atividade , Linhagem Celular , Anti-Inflamatórios não Esteroides/farmacologia , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/isolamento & purificação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA