Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Sci Total Environ ; 926: 171936, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38527554

RESUMO

There is limited understanding regarding the changes in the ecological processes and the mechanisms of archaeal community in response to heavy metal contamination in the marine sediments. In this study, sediment samples were collected from 46 locations near harbors, and the concentration of heavy metals and the diversity of archaeal communities were investigated to understand the impact of Cd on archaeal communities. The results demonstrated a significant correlation between the diversity of archaeal community and Cd concentration, particularly showing a linear decrease in the species richness with rising Cd concentration. ANME-1b was identified as a significantly enriched archaeal taxon in the higher Cd environment. Null model and neutral community model indicated that the ecological assembly of archaeal communities in marine sediments was primarily governed by the stochastic processes, with dispersal limitation being the primary factor. The contribution of deterministic process to the assembly of archaeal communities in higher Cd environments increased clearly, accompanied by a notable reduction in species migration rates and widths of ecological niche of archaeal populations. Co-occurrence network analysis revealed an obvious increase in species interactions in higher Cd environments, with an apparent rise in the proportion of competitive relationships and an increase in the number of keystone species. Moreover, archaeal species formed a more complex and stable community to cope with Cd stress. This study provides new insights into the impacts of heavy metals on the ecological processes of marine microorganisms and the underlying mechanisms.


Assuntos
Archaea , Metais Pesados , Archaea/genética , Cádmio/análise , Sedimentos Geológicos , RNA Ribossômico 16S/análise , Metais Pesados/análise
2.
J Hazard Mater ; 460: 132309, 2023 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-37639798

RESUMO

The microbial community assembly processes and underlying mechanisms in response to heavy metal accumulation in coastal sediments remain underexplored. In this study, the heavy metal concentration in samples were found below the marine sediment quality standards. Through partial Mantel tests and linear regression analysis, Cd was identified as the major influencing factor, displaying strongest correlation with the bacterial community in the sediments. The class Desulfuromonadia was identified as a biomarker which showed enrichment in the sediments with high Cd content. Additionally, the results of null model and the neutral community model demonstrated the prominent role of stochastic processes in the assembly of bacterial community. However, with the increase in Cd concentration, the influence of selection processes intensified, resulting in a decline in species migration rate and subsequent reduction in ecological niche width. Furthermore, the intensified competition and an increase in keystone species among bacterial populations further enhanced the stability of the microbial co-occurrence network in response to high Cd concentration. This study offers an insight into the effects of heavy metal on microbial assembly and coexistence, which are conducive to marine ecosystem management and conservation.


Assuntos
Cádmio , Microbiota , Sedimentos Geológicos , Modelos Lineares , Consórcios Microbianos
3.
Cancer Med ; 12(10): 11211-11233, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37161541

RESUMO

OBJECTIVE: The aim of this meta-analysis was to summarize the available results of immunotherapy predictors for small cell lung cancer (SCLC) and to provide evidence-based information for their potential predictive value of efficacy. METHODS: We searched PubMed, EMBASE, Web of Science, The Cochrane Library, and ClinicalTrials (from January 1, 1975 to November 1, 2021). The hazard ratios (HR) and its 95% confidence intervals (CIs) and tumor response rate of the included studies were extracted. RESULTS: Eleven studies were eventually included and the pooled results showed that programmed cell death ligand 1 (PD-L1) positive: objective response rate (ORR) (relative risk [RR] = 1.39, 95% CI [0.48, 4.03], p = 0.54), with high heterogeneity (p = 0.05, I2  = 56%); disease control rate [DCR] (RR = 1.31, 95% CI [0.04, 38.57], p = 0.88), with high heterogeneity (p = 0.04, I2  = 75%); overall survival (OS) (HR = 0.89, 95% CI [0.74, 1.07], p = 0.22); and progression-free survival (PFS) (HR = 0.83, 95% CI [0.59, 1.16], p = 0.27), with high heterogeneity (p = 0.005, I2  = 73.1%). TMB-High (TMB-H): OS (HR = 0.86, 95% CI [0.74, 1.00], p = 0.05); PFS (HR = 0.71, 95% CI [0.6, 0.85], p < 0.001). Lactate dehydrogenase (LDH) >upper limit of normal (ULN): OS (HR = 0.95, 95% CI [0.81, 1.11], p = 0.511). Asian patients: OS (HR = 0.87, 95% CI [0.72, 1.04], p = 0.135); White/Non-Asian patients: OS (HR = 0.83, 95% CI [0.76, 0.90], p < 0.001). Liver metastasis patients: OS (HR = 0.93, 95% CI [0.83, 1.05], p = 0.229); PFS (HR = 0.84, 95% CI [0.67, 1.06], p = 0.141). Central nervous system (CNS) metastasis patients: OS (HR = 0.91, 95% CI [0.71, 1.17], p = 0.474); PFS (HR = 1.03, 95% CI [0.66, 1.60], p = 0.903). CONCLUSION: The available research results do not support the recommendation of PD-L1 positive and TMB-H as predictors for the application of immune checkpoint inhibitors (ICIs) in SCLC patients. LDH, baseline liver metastasis and CNS metastasis may be used as markers/influencing factors for predicting the efficacy of ICIs in SCLC patients. Non-Asian SCLC patients had better efficacy with ICIs in our results.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Hepáticas , Neoplasias Pulmonares , Segunda Neoplasia Primária , Carcinoma de Pequenas Células do Pulmão , Humanos , Carcinoma de Pequenas Células do Pulmão/tratamento farmacológico , Inibidores de Checkpoint Imunológico/uso terapêutico , Antígeno B7-H1 , Biomarcadores , L-Lactato Desidrogenase , Neoplasias Pulmonares/tratamento farmacológico
4.
Angew Chem Int Ed Engl ; 62(18): e202301925, 2023 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-36866977

RESUMO

Spin manipulation of transition-metal catalysts has great potential in mimicking enzyme electronic structures to improve activity and/or selectivity. However, it remains a great challenge to manipulate room-temperature spin state of catalytic centers. Herein, we report a mechanical exfoliation strategy to in situ induce partial spin crossover from high-spin (s=5/2) to low-spin (s=1/2) of the ferric center. Due to spin transition of catalytic center, mixed-spin catalyst exhibits a high CO yield of 19.7 mmol g-1 with selectivity of 91.6 %, much superior to that of high-spin bulk counterpart (50 % selectivity). Density functional theory calculations reveal that low-spin 3d-orbital electronic configuration performs a key function in promoting CO2 adsorption and reducing activation barrier. Hence, the spin manipulation highlights a new insight into designing highly efficient biomimetic catalysts via optimizing spin state.

5.
Food Chem ; 401: 134126, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36088714

RESUMO

To clarify the role of Acetobacter sp. in fermented noni juice, the physiochemical properties, main active ingredients and volatile constituents were comprehensively analyzed. The sugar content and acidity tended to be stable after 12 days of fermentation. Acetobacter sp. had no significant influence on major active ingredients of products. The headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) were performed to describe the characteristic flavor profiles during fermentation. A total of 55 flavor compounds were screened with odour threshold and Kruskal-Wallis p < 0.05. Among them, 14 different biomarkers were selected with Variable Importance in Projection (VIP) greater than 1. The concentrations of ketones and aldehydes increased significantly, mainly contributing to the floral, fruit and green features. The content of hexanoic acid, octanoic acid and butanoic acid as the main source of peculiar odor were significantly reduced, indicating Acetobacter sp. could improve the unpleasant odor of fermented noni juice.


Assuntos
Acetobacter , Morinda , Odorantes , Ácido Butírico , Cromatografia Gasosa-Espectrometria de Massas , Frutas/química , Açúcares/análise , Aldeídos/análise , Cetonas/análise
6.
Neoplasma ; 68(6): 1132-1138, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34779643

RESUMO

Prostate cancer (PCa) is one of the most common malignancies in men worldwide, and metastatic castrate-resistant prostate cancer (mCRPC) has shown a poor prognosis. Although chemotherapy and androgen deprivation therapy (ADT) have improved clinical outcomes, the median survival (MS) of patients with mCRPC is still less than 2 years. With the development of poly adenosine diphosphate-ribose polymerase inhibitor (PARPi), the treatment strategy for patients with mCRPC has markedly evolved. Olaparib, a type of PARPi that can selectively induce synthetic lethality in cancer cells with homologous recombination (HR) deficiencies, was the first type of PARPi approved for treating patients with mCRPC harboring mutations in HR repair (HRR) genes. This review discusses and summarizes the latest progress on therapeutic mechanisms, monotherapy, combination therapy, and adverse events of Olaparib.


Assuntos
Antagonistas de Androgênios , Neoplasias de Próstata Resistentes à Castração , Antagonistas de Androgênios/uso terapêutico , Humanos , Masculino , Ftalazinas/uso terapêutico , Piperazinas , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico
8.
Exp Ther Med ; 22(3): 975, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34335917

RESUMO

Diabetic macular edema (DME) is the main cause of visual impairment in diabetic patients, but its pathogenesis remains unclear. The purpose of the present study was to analyze the expression of microRNA (miR)-155-5p in patients with DME and its regulatory mechanism. A total of 72 patients diagnosed with DME and 17 with idiopathic macular hole (MH) were recruited. Among samples from patients with DME, 45 were DME and 27 were refractory DME, whereas patients with idiopathic MH served as the control group. Optical coherence tomography and fundus photograph analysis revealed that part of the retina in the fundus of patients with DME was thickened, with macular edema occurring simultaneously. In refractory patients with DME, macular edema was associated with bleeding and a dark cavity between retinal layers. Through reverse transcription-quantitative PCR analysis, miR-155-5p was highly expressed in the aqueous humor (AH) and plasma of patients with DME compared with that in patients with MH, and this was even higher in the refractory DME group. Upon analyzing patient clinical data, the difference in miR-155-5p expression in the AH and plasma was positively associated with disease course, body mass index, fasting blood-glucose, glycated hemoglobin, proteinuria and glycosuria. The expression of miR-155-5p was not significantly different based on hemoglobin, intraocular pressure and sex. The aforementioned results indicate that miR-155-5p might promote the development of DME. To further study the molecular mechanism, human retinal microvascular endothelial cells (HRMECs) were cultured and treated with high glucose in vitro. The results showed that miR-155-5p expression was significantly upregulated in HRMECs induced by high glucose. After inhibiting the expression of miR-155-5p, cell proliferation, angiogenesis and VEGF protein levels were significantly downregulated, whereas miR-155-5p mimics had the opposite effect. In summary, miR-155-5p is closely associated with DME and is a potential target for refractory DME treatment.

9.
Front Immunol ; 12: 659150, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33995378

RESUMO

Previous studies have established that disturbed lymphocytes are involved in the pathogenesis of Vogt-Koyanagi-Harada (VKH) syndrome. Accordingly, glucocorticoids (GCs), with their well-recognized immune-suppressive function, have been widely used for treatment of VKH patients with acute relapses. However, the systemic response of diverse immune cells to GC therapy in VKH is poorly characterized. To address this issue, we analyzed immune cell subpopulations and their phenotype, as well as cytokine profiles in peripheral blood from VKH patients (n=25) and health controls (HCs, n=21) by flow cytometry and luminex technique, respectively. For 16 patients underwent GC therapy (methylprednisolone, MP), the aforementioned measurements as well as the transcriptome data from patients before and after one-week's GC therapy were also compared to interrogate the systemic immune response to GC therapy. Lymphocyte composition in the blood was different in VKH patients and HCs. VKH patients had significantly higher numbers of T cells with more activated, polarized and differentiated phenotype, more unswitched memory B cells and monocytes, as compared to HCs. MP treatment resulted in decreased frequencies of T cells and NK cells, inhibited NK cell activation and T cell differentiation, and more profoundly, a marked shift in the distribution of monocyte subsets. Collectively, our findings suggest that advanced activation and differentiation, as well as dysregulated numbers of peripheral lymphocytes are the major immunological features of VKH, and GC therapy with MP not only inhibits T cell activation directly, but also affects monocyte subsets, which might combinatorically result in the inhibition of the pathogenic immune response.


Assuntos
Biomarcadores , Glucocorticoides/uso terapêutico , Imunofenotipagem , Imunossupressores/uso terapêutico , Síndrome Uveomeningoencefálica/diagnóstico , Síndrome Uveomeningoencefálica/tratamento farmacológico , Adulto , Autoimunidade , Estudos de Casos e Controles , Citocinas/metabolismo , Feminino , Glucocorticoides/administração & dosagem , Humanos , Imunossupressores/administração & dosagem , Leucócitos/imunologia , Leucócitos/metabolismo , Subpopulações de Linfócitos/imunologia , Subpopulações de Linfócitos/metabolismo , Masculino , Pessoa de Meia-Idade , Monócitos/imunologia , Monócitos/metabolismo , Resultado do Tratamento , Síndrome Uveomeningoencefálica/etiologia
10.
Appl Microbiol Biotechnol ; 105(5): 2157-2169, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33555363

RESUMO

Serpentine has weak immobilization capacity for Pb(II), especially under acidic conditions. In order to improve its application potential, a new biological modification method was adopted, i.e., the serpentine powder was weathered by Aspergillus niger and the fungus-serpentine aggregation (FSA) formed was investigated for its Pb(II) immobilization potential and underlying mechanism. Batch adsorption of Pb(II) by FSA closely followed the Langmuir model, while the maximum adsorption capacity of FSA (370.37 mg/g) was significantly higher than fungal mycelium (31.85 mg/g) and serpentine (8.92 mg/g). The adsorption process can be accurately simulated by pseudo-second-order kinetic model. Our data revealed the loading of organic matter is closely related to the adsorption of FSA, and the stronger immobilization capacity was mainly related to its modified porous organic-inorganic composite structure with extensive exchangeable ions. Moreover, FSA is an economical bio-material with excellent Pb(II) adsorption (pH = 1-8) along with significantly lower desorption efficiency (pH = 3-8), especially under acidic conditions. These findings provide a new perspective to explore the usage of fungus-minerals aggregation on heavy metals immobilization in acidic environments. Key Points • Co-culture of Aspergillus niger and serpentine produced a porous composite material like fungus-serpentine aggregation. • Fungus-serpentine aggregation has a surprisingly higher adsorption capacity of Pb(II) and significantly lower desorption efficiency under acidic conditions. • The loading of organic matter is closely related to the adsorption of FSA.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Adsorção , Concentração de Íons de Hidrogênio , Íons , Cinética , Minerais , Poluentes Químicos da Água/análise
11.
Sci Total Environ ; 760: 143357, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33198997

RESUMO

Using cheap raw materials and simple biological modification methods to obtain modified materials to remediate heavy metals has potential application prospects. Here, Aspergillus niger was used to modify wollastonite and further explore its fixation capacity and mechanism. The results showed that the growth and metabolism of A. niger promoted the weathering of wollastonite and the synthesis of whewellite, forming a mineral composite through fungal modification (MCF) with excellent fixation properties of heavy metal Pb2+. The maximum adsorption capacity of MCF for Pb2+ (434.78 mg/g) is significantly greater than that of original wollastonite (11.86 mg/g) with a desired lower desorption rate. Additionally, its removal rate of Pb2+ is higher than 75% under varying acidic conditions (1 ≤ pH ≤ 5.5). The results of XRD, FTIR, BET specific surface area, and SEM-EDS showed that MCF has a special organic-inorganic composite structure, which imparts a larger contact area for ions, and efficient removal of Pb2+ through combined physico-chemical adsorption. Batch adsorption results also indicated that the adsorption process by MCF was mainly a spontaneous endothermic reaction in the monolayer. This study provides a new perspective for the bio-modification of wollastonite and its application in the remediation of heavy metal pollution.


Assuntos
Chumbo , Poluentes Químicos da Água , Adsorção , Cádmio , Compostos de Cálcio , Cinética , Silicatos , Poluentes Químicos da Água/análise
12.
Inorg Chem ; 59(20): 15460-15466, 2020 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-32990428

RESUMO

Photochromism is an important strategy for realizing reversible light-controllable fluorescence switching. In spite of several reports on fluorescence switching via a photochromic process, the success of photochromic multimetallic complexes reversibly showing fluorescence switching in the solid or crystalline state has been limited for their application importance. Here, we report a photoswitchable near-infrared (NIR) fluorescence based on photochromism in the azo-label 3d/4f heterometal-organic rhomboids, azo-Zn2Ln2 (Ln = Eu (1), Yb (2), and Er (3)), in the crystalline state. An individual metallorhomboid contains up to four azobenzene fragments, which is prepared via the three-component assembly of a trans-azobenzene-grafted multifunctional ligand, and 3d and 4f metal ions. The photoisomerization quantum yields of azo-Zn2Ln2 complexes can be retained or even higher when compared to the free ligand due to the modification of electronic structure. The impressive crystalline-state NIR luminescence is observed for the complexes of azo-Zn2Yb2 (2) and azo-Zn2Er2 (3) at room temperature. Intriguingly, the switchable NIR luminescence can be effectively regulated by photochromism in the crystalline state. These features endow the self-assembly of the 3d/4f metallorhomboid with synergetic multifunctional behavior between photochromism and NIR luminescence.

13.
Dalton Trans ; 49(34): 12082-12087, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32820779

RESUMO

White light-emitting diodes (WLEDs) have aroused great attention due to their potential technological applications. In this work, we present two new Zn(ii) anthracene-linker-driven coordination polymers that exhibit intrinsic white-light emission. The emission covers the whole visible spectrum at room temperature. The chromaticity coordinates of the broadband emission can be tuned under external stimuli, including thermal and mechanical grinding. The obtained coordination polymer materials emit a "warm" white light at room temperature suitable for indoor lighting applications as well as a "cold" white light at the cryogenic temperature. Hence, the well-defined structures and mechanically tunable emission provide an excellent opportunity for realizing their potential as white emitters in optoelectronics.

14.
Inorg Chem ; 58(7): 4524-4533, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30895776

RESUMO

Postsynthetic modification represents an efficient strategy for the fabrication of tunable metal-organic frameworks (MOFs) and derived high-performance functional materials. Herein, we report the synthesis of a mixed-linker zinc(II)-based double-layered MOF (dlMOF) with dual-emissive luminescence, which was further applied as a host matrix to fabricate highly tunable Ln@dlMOF materials (Ln = Eu, Tb, Eu/Tb). The emission characteristics of these materials can be readily modulated over a wide spectrum, including white light emission, by simply tuning the Eu3+/Tb3+ molar ratio in EuTb@dlMOF. Furthermore, by virtue of the difference in thermal sensitivity between triple-emissive sources, the Eu3+/Tb3+-codoped thermometer EuTb@dlMOF exhibits real-time successive chromogenic switches from red (room temperature) to white (intermediate temperature) to blue/green (cryogenic temperature) emission in a wide temperature region. The versatile performance and the facile assembly from easily available linkers suggest that postsynthetic lanthanide encapsulation represents an efficient strategy for the future engineering of advanced photoluminescent materials with stimuli-responsive and thermochromic properties.

15.
Scanning ; 26(5 Suppl 1): I47-51, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15540813

RESUMO

The near-field images of interferences generated by the reflection or by the interactions of four evanescent fields of two different wavelengths are obtained. The near-field interactions of the evanescent fields are studied.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...