Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 186
Filtrar
1.
J Immunol ; 210(9): 1408-1418, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-36971659

RESUMO

Complement receptor type 2 (CR2) is an important membrane molecule expressed on B cells and follicular dendritic cells. Human CR2 has been shown to play a critical role in bridging the innate complement-mediated immune response with adaptive immunity by binding complement component 3d (C3d). However, the chicken CR2 (chCR2) gene has not been identified or characterized. In this study, unannotated genes that contain short consensus repeat (SCR) domains were analyzed based on RNA sequencing data for chicken bursa lymphocytes, and a gene with >80% homology to CR2 from other bird species was obtained. The gene consisted of 370 aa and was much smaller than the human CR2 gene because 10-11 SCRs were missing. The gene was then demonstrated as a chCR2 that exhibited high binding activity to chicken C3d. Further studies revealed that chCR2 interacts with chicken C3d through a binding site in its SCR1-4 region. An anti-chCR2 mAb that recognizes the epitope 258CKEISCVFPEVQ269 was prepared. Based on the anti-chCR2 mAb, the flow cytometry and confocal laser scanning microscopy experiments confirmed that chCR2 was expressed on the surface of bursal B lymphocytes and DT40 cells. Immunohistochemistry and quantitative PCR analyses further indicated that chCR2 is predominantly expressed in the spleen, bursa, and thymus, as well as in PBLs. Additionally, the expression of chCR2 varied according to the infectious bursal disease virus infection status. Collectively, this study identified and characterized chCR2 as a distinct immunological marker in chicken B cells.


Assuntos
Galinhas , Complemento C3d , Animais , Humanos , Complemento C3d/metabolismo , Receptores de Complemento 3d/metabolismo , Sítios de Ligação , Fatores Imunológicos , Receptores de Complemento
2.
Mikrochim Acta ; 191(4): 217, 2024 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-38519619

RESUMO

Hypoxia, a significant feature of the tumor microenvironment, is closely associated with tumor growth, metastasis, and drug resistance. In the field of tumor microenvironment analysis, accurately imaging and quantifying hypoxia - a critical factor associated with tumor progression, metastasis, and resistance to therapy - remains a significant challenge. Herein, a hypoxia-activated red-emission fluorescent probe, ODP, for in vivo imaging of hypoxia in the tumor microenvironment is presented. Among various imaging methods, optical imaging is particularly convenient due to its rapid response and high sensitivity. The ODP probe specifically targets nitroreductase (AzoR), an enzyme highly expressed in hypoxic cells, playing a vital role by catalyzing the cleavage of azo bonds. The optical properties of ODP exhibited excellent performance in terms of fluorescence enhancement, fluorescence lifetime (0.81 ns), and detection limit (0.86 µM) in response to SDT. Cell imaging experiments showed that ODP could effectively detect and image intracellular hypoxia and the imaging capability of ODP was studied under various conditions including cell migration, antioxidant treatment, and different incubation times. Through comprehensive in vitro and in vivo experiments, including cellular imaging and mouse tumor models, this work demonstrates the efficacy of ODP in accurately detecting and imaging hypoxia. Moreover, ODP's potential in inducing apoptosis in cancer cells offers a promising avenue for integrating diagnostic and therapeutic strategies in cancer treatment. This innovative approach not only contributes to the understanding and assessment of tumor hypoxia but also opens new possibilities for targeted cancer therapy.


Assuntos
Corantes Fluorescentes , Neoplasias , Camundongos , Animais , Corantes Fluorescentes/química , Microambiente Tumoral , Microscopia de Fluorescência/métodos , Hipóxia , Imagem Óptica/métodos , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico
3.
Small ; 19(18): e2206718, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36737849

RESUMO

Metal-organic framework (MOF) gel, an emerging subtype of MOF structure, is unique in formation and function; however, its evolutionary process remains elusive. Here, the evolution of a model gel-based MOF, UiO-66(Zr) gel, is explored by demonstrating its sequential sol-gel self-assembly and nonclassical gel-crystal transformation. The control of the sol-gel process enables the observation and characterization of structures in each assembly stage (phase-separation, polycondensation, and hindered-crystallization) and facilitates the preparation of hierarchical materials with giant mesopores. The gelation mechanism is tentatively attributed to the formation of zirconium oligomers. By further utilizing the pre-synthesized gel, the nonclassical gel-crystal transformation is achieved by the modulation in an unconventional manner, which sheds light on crystal intermediates and distinct crystallization motions ("growth and splitting" and "aggregation and fusion"). The overall sol-gel and gel-crystal evolutions of UiO-66(Zr) enrich self-assembly and crystallization domains, inspire the design of functional structures, and demand more in-depth research on the intermediates in the future.

4.
Plant Biotechnol J ; 21(5): 1058-1072, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36710373

RESUMO

The rubber tree (Hevea brasiliensis) is grown in tropical regions and is the major source of natural rubber. Using traditional breeding approaches, the latex yield has increased by sixfold in the last century. However, the underlying genetic basis of rubber yield improvement is largely unknown. Here, we present a high-quality, chromosome-level genome sequence of the wild rubber tree, the first report on selection signatures and a genome-wide association study (GWAS) of its yield traits. Population genomic analysis revealed a moderate population divergence between the Wickham clones and wild accessions. Interestingly, it is suggestive that H. brasiliensis and six relatives of the Hevea genus might belong to the same species. The selective sweep analysis found 361 obvious signatures in the domesticated clones associated with 245 genes. In a 15-year field trial, GWAS identified 155 marker-trait associations with latex yield, in which 326 candidate genes were found. Notably, six genes related to sugar transport and metabolism, and four genes related to ethylene biosynthesis and signalling are associated with latex yield. The homozygote frequencies of the causal nonsynonymous SNPs have been greatly increased under selection, which may have contributed to the fast latex yield improvement during the short domestication history. Our study provides insights into the genetic basis of the latex yield trait and has implications for genomic-assisted breeding by offering valuable resources in this new domesticated crop.


Assuntos
Hevea , Borracha , Borracha/metabolismo , Hevea/genética , Hevea/metabolismo , Látex/metabolismo , Estudo de Associação Genômica Ampla , Melhoramento Vegetal , Genômica , Cromossomos/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética
5.
Acc Chem Res ; 55(2): 186-196, 2022 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-34958204

RESUMO

ConspectusPorous metal-organic frameworks (MOFs), formed from organic linkers and metal nodes, have attracted intense research attention. Because of their high specific surface areas, uniform and adjustable pore sizes, and versatile physicochemical properties, MOFs have shown disruptive potential in adsorption, catalysis, separation, etc. For many of these applications, MOFs are synthesized solvothermally as bulk powders and subsequently shaped as pellets or extrudates. Other applications, such as membrane separations and (opto)electronics, require the implementation of MOFs as (patterned) thin films. Most thin-film formation methods are adapted from liquid-phase synthesis protocols. Precursor transport and nucleation are difficult to control in these cases, often leading to particle formation in solution. Moreover, the use of solvents gives rise to environmental and safety challenges, incompatibility issues with some substrates, and corrosion issues in the case of dissolved metal salts. In contrast, vapor-phase processing methods have the merits of environmental friendliness, control over thickness and conformality, scalability in production, and high compatibility with other workflows.In this Account, we outline some of our efforts and related studies in the development and application of vapor-phase processing of crystalline MOF materials (MOF-VPP). We first highlight the advances and mechanisms in the vapor-phase deposition of MOFs (MOF-VPD), mainly focusing on the reactions between a linker vapor and a metal-containing precursor layer. The characteristics of the obtained MOFs (thickness, porosity, crystallographic phase, orientation, etc.) and the correlation of these properties with the deposition parameters (precursors, temperatures, humidity, post-treatments, etc.) are discussed. Some in situ characterization methods that contributed to a fundamental understanding of the involved mechanisms are included in the discussion. Second, four vapor-phase postsynthetic functionalization (PSF) methods are summarized: linker exchange, guest loading, linker grafting, and metalation. These approaches eliminate potential solubility issues and enable fast diffusion of reactants and guests as well as a high loading or degree of exchange. Vapor-phase PSF provides a platform to modify the MOF porosity or even introduce new functionalities (e.g., luminescence photoswitching and catalytic activity). Third, since vapor-phase processing methods enable the integration of MOF film deposition into a (micro)fabrication workflow, they facilitate a range of applications with improved performance (low-k dielectrics, sensors, membrane separations, etc.). Finally, we provide a discussion on the limitations, challenges, and further opportunities for MOF-VPP. Through the discussion and analysis of the vapor-phase processing strategies as well as the underlying mechanisms in this Account, we hope to contribute to the development of the controllable synthesis, functionalization, and application of MOFs and related materials.

6.
Sensors (Basel) ; 23(24)2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-38139681

RESUMO

Forcing pathways between urban surfaces (impervious and pervious pavers) and near-surface air temperature were measured and investigated with a network of multiple sensors. Utilizing field data measured between April 2021 and May 2022, and assuming that the influential variables follow the basic heat-transfer energy-balance equations, multiple regression-based statistical models were built to predict the surface temperature and near-surface air temperature (0.05 m, 0.5 m, 1 m, 2 m, and 3 m) of one impervious paver site and one pervious paver site in Taipei City, Taiwan. Evaporative cooling was found to be more influential on the pervious paver with a statistically significant influence on the microclimate up to 1.8 m (and up to 0.7 m for the impervious paver), using in situ data with an ambient air temperature higher than 24 °C. The surface temperature is mainly affected by solar shortwave radiation and ambient air temperature. As for near-surface air temperature, ambient air temperature is the most influential factor, followed by surface temperature. The importance of surface temperature indicates the influence of upwelling longwave radiation on the microclimate. The predictive equations show that pervious surfaces can help cities with hot and humid climates fight the changing climate in the future.

7.
Int J Mol Sci ; 24(19)2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37833996

RESUMO

The extensive use of fossil fuels and global climate change have raised ever-increasing attention to sustainable development, global food security and the replacement of fossil fuels by renewable energy. Several C4 monocot grasses have excellent photosynthetic ability, stress tolerance and may rapidly produce biomass in marginal lands with low agronomic inputs, thus representing an important source of bioenergy. Among these grasses, Sorghum bicolor has been recognized as not only a promising bioenergy crop but also a research model due to its diploidy, simple genome, genetic diversity and clear orthologous relationship with other grass genomes, allowing sorghum research to be easily translated to other grasses. Although sorghum molecular genetic studies have lagged far behind those of major crops (e.g., rice and maize), recent advances have been made in a number of biomass-related traits to dissect the genetic loci and candidate genes, and to discover the functions of key genes. However, molecular and/or targeted breeding toward biomass-related traits in sorghum have not fully benefited from these pieces of genetic knowledge. Thus, to facilitate the breeding and bioenergy applications of sorghum, this perspective summarizes the bioenergy applications of different types of sorghum and outlines the genetic control of the biomass-related traits, ranging from flowering/maturity, plant height, internode morphological traits and metabolic compositions. In particular, we describe the dynamic changes of carbohydrate metabolism in sorghum internodes and highlight the molecular regulators involved in the different stages of internode carbohydrate metabolism, which affects the bioenergy utilization of sorghum biomass. We argue the way forward is to further enhance our understanding of the genetic mechanisms of these biomass-related traits with new technologies, which will lead to future directions toward tailored designing sorghum biomass traits suitable for different bioenergy applications.


Assuntos
Sorghum , Sorghum/genética , Sorghum/metabolismo , Biomassa , Melhoramento Vegetal , Poaceae/genética , Poaceae/metabolismo , Grão Comestível , Combustíveis Fósseis
8.
Plant J ; 107(5): 1513-1532, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34181801

RESUMO

De novo shoot organogenesis is an important biotechnological tool for fundamental studies in plant. However, it is difficult in most bamboo species, and the genetic control of this highly dynamic and complicated regeneration process remains unclear. In this study, based on an in-depth analysis at the cellular level, the shoot organogenesis from calli of Ma bamboo (Dendrocalamus latiflorus Munro) was divided into five stages. Subsequently, single-molecule long-read isoform sequencing of tissue samples pooled from all five stages was performed to generate a full-length transcript landscape. A total of 83 971 transcripts, including 73 209 high-quality full-length transcripts, were captured, which served as an annotation reference for the subsequent RNA sequencing analysis. Time-course transcriptome analysis of samples at the abovementioned five stages was conducted to investigate the global gene expression atlas showing genome-wide expression of transcripts during the course of bamboo shoot organogenesis. K-means clustering analysis and stage-specific transcript identification revealed important dynamically expressed transcription regulators that function in bamboo shoot organogenesis. The majority of abiotic stress-responsive genes altered their expression levels during this process, and further experiments demonstrated that exogenous application of moderate but not severe abiotic stress increased the shoot regeneration efficiency. In summary, our study provides an overview of the genetic flow dynamics during bamboo shoot organogenesis. Full-length cDNA sequences generated in this study can serve as a valuable resource for fundamental and applied research in bamboo in the future.


Assuntos
Bambusa/genética , Organogênese Vegetal/genética , Estresse Fisiológico , Transcriptoma , Bambusa/crescimento & desenvolvimento , Bambusa/fisiologia , DNA Complementar/genética , Perfilação da Expressão Gênica , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/fisiologia , RNA de Plantas/genética , Análise de Sequência de RNA , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
9.
Mol Cancer ; 21(1): 121, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35650603

RESUMO

BACKGROUND: circular RNAs (circRNAs) have been reported to play crucial roles in the biology of different cancers. However, little is known about the function of circSTX6 (hsa_circ_0007905) in pancreatic ductal adenocarcinoma (PDAC). METHODS: circSTX6, a circRNA containing exons 4, 5, 6 and 7 of the STX6 gene, was identified by RNA sequencing and detected by quantitative reverse transcription PCR (qRT-PCR). The biological function of circSTX6 was assessed in vitro and in vivo. The relationship between circSTX6 and miR-449b-5p was confirmed by biotin-coupled circRNA capture, fluorescence in situ hybridization (FISH) and luciferase reporter assays. The interaction of circSTX6 with Cullin 2 (CUL2) was verified by RNA-protein RNA pull-down, RNA immunoprecipitation (RIP) and western blotting assays. RESULTS: circSTX6 was frequently upregulated in PDAC tissues, and circSTX6 overexpression promoted tumor proliferation and metastasis both in vitro and in vivo. Furthermore, circSTX6 expression was associated with tumor differentiation and N stage. Mechanistically, circSTX6 regulated the expression of non-muscle myosin heavy chain 9 (MYH9) by sponging miR-449b-5p. Moreover, circSTX6 was confirmed to participate in the ubiquitin-dependent degradation of hypoxia-inducible factor 1-alpha (HIF1A) by interacting with CUL2 and subsequently accelerating the transcription of MYH9. CONCLUSIONS: Our findings indicate that circSTX6 facilitates proliferation and metastasis of PDAC cells by regulating the expression of MYH9 through the circSTX6/miR-449b-5p axis and circSTX6/CUL2/HIF1A signaling pathway. Therefore, circSTX6 could serve as a potential therapeutic target for the treatment of PDAC.


Assuntos
Carcinoma Ductal Pancreático , Proteínas Culina , MicroRNAs , Neoplasias Pancreáticas , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Proteínas Culina/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Hibridização in Situ Fluorescente , MicroRNAs/genética , Neoplasias Pancreáticas/patologia , Proteínas Qa-SNARE , RNA Circular/genética , Neoplasias Pancreáticas
10.
Nat Mater ; 20(1): 93-99, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33106648

RESUMO

Metal-organic frameworks (MOFs) offer disruptive potential in micro- and optoelectronics because of the unique properties of these microporous materials. Nanoscale patterning is a fundamental step in the implementation of MOFs in miniaturized solid-state devices. Conventional MOF patterning methods suffer from low resolution and poorly defined pattern edges. Here, we demonstrate the resist-free, direct X-ray and electron-beam lithography of MOFs. This process avoids etching damage and contamination and leaves the porosity and crystallinity of the patterned MOFs intact. The resulting high-quality patterns have excellent sub-50-nm resolution, and approach the mesopore regime. The compatibility of X-ray and electron-beam lithography with existing micro- and nanofabrication processes will facilitate the integration of MOFs in miniaturized devices.

11.
Molecules ; 27(15)2022 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-35897869

RESUMO

In order to discover pesticidal lead compounds with high activity and low toxicity, a series of novel benzamides substituted with pyrazole-linked 1,2,4-oxadiazole were designed via bioisosterism. The chemical structures of the target compounds were confirmed via 1H NMR, 13C NMR and HRMS analysis. The preliminary bioassay showed that most compounds exhibited good lethal activities against Mythimna separate, Helicoverpa armigera, Ostrinia nubilalis and Spodoptera frugiperda at 500 mg/L. Particularly in the case of Mythimna separate, compound 14q (70%) exhibited obvious insecticidal activity. In addition, compound 14h demonstrated good fungicidal activity against Pyricularia oryae with an inhibition rate of 77.8%, and compounds 14e, 14k, 14n and 14r also showed certain antifungal activities (55.6-66.7%). The zebrafish toxicity test showed that the LC50 of compound 14h was 14.01 mg/L, which indicated that it may be used as a potential leading compound for further structural optimization.


Assuntos
Inseticidas , Mariposas , Animais , Benzamidas , Desenho de Fármacos , Inseticidas/toxicidade , Estrutura Molecular , Oxidiazóis/química , Oxidiazóis/toxicidade , Pirazóis/toxicidade , Relação Estrutura-Atividade , Peixe-Zebra
12.
Molecules ; 27(12)2022 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-35745068

RESUMO

To develop new compounds with high activity, broad spectrum and low-toxicity, 17 benzamides substituted with quinoline-linked 1,2,4-oxadiazole were designed using the splicing principle of active substructures and were synthesized. The biological activities were evaluated against 10 fungi, indicating that some of the synthetic compounds showed excellent fungicidal activities. For example, at 50 mg/L, the inhibitory activity of 13p (3-Cl-4-Cl substituted, 86.1%) against Sclerotinia sclerotiorum was superior to that of quinoxyfen (77.8%), and the inhibitory activity of 13f (3-CF3 substituted, 77.8%) was comparable to that of quinoxyfen. The fungicidal activities of 13f and 13p to Sclerotinia sclerotiorum were better than that of quinoxyfen (14.19 mg/L), with EC50 of 6.67 mg/L and 5.17 mg/L, respectively. Furthermore, the acute toxicity of 13p was 19.42 mg/L, classifying it as a low-toxic compound.


Assuntos
Ascomicetos , Fungicidas Industriais , Quinolinas , Animais , Benzamidas/farmacologia , Fungicidas Industriais/farmacologia , Estrutura Molecular , Oxidiazóis/química , Oxidiazóis/farmacologia , Quinolinas/farmacologia , Relação Estrutura-Atividade , Peixe-Zebra
13.
Hum Brain Mapp ; 42(7): 2018-2031, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33416206

RESUMO

Differentiating between subcortical ischemic vascular disease (SIVD), Alzheimer's disease (AD), and normal cognition (NC) remains a challenge, and reliable neuroimaging biomarkers are needed. The current study, therefore, investigated the discriminative ability of diffusion kurtosis imaging (DKI) metrics in segregated thalamic regions and compare with diffusion tensor imaging (DTI) metrics. Twenty-three SIVD patients, 30 AD patients, and 24 NC participants underwent brain magnetic resonance imaging. The DKI metrics including mean kurtosis (MK), axial kurtosis (Kaxial ) and radial kurtosis (Kradial ) and the DTI metrics including diffusivity and fractional anisotropy (FA) were measured within the whole thalamus and segregated thalamic subregions. Strategic correlations by group, thalamo-frontal connectivity, and canonical discriminant analysis (CDA) were used to demonstrate the discriminative ability of DKI for SIVD, AD, and NC. Whole and segregated thalamus analysis suggested that DKI metrics are less affected by white matter hyperintensities compared to DTI metrics. Segregated thalamic analysis showed that MK and Kradial were notably different between SIVD and AD/NC. The correlation analysis between Kaxial and MK showed a nonsignificant relationship in SIVD group, a trend of negative relationship in AD group, and a significant positive relationship in NC group. A wider spatial distribution of thalamo-frontal connectivity differences across groups was shown by MK compared to FA. CDA showed a discriminant power of 97.4% correct classification using all DKI metrics. Our findings support that DKI metrics could be more sensitive than DTI metrics to reflect microstructural changes within the gray matter, hence providing complementary information for currently outlined pathogenesis of SIVD and AD.


Assuntos
Doença de Alzheimer/patologia , Isquemia Encefálica/patologia , Imagem de Difusão por Ressonância Magnética/métodos , Lobo Frontal/patologia , Rede Nervosa/patologia , Tálamo/patologia , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/diagnóstico por imagem , Isquemia Encefálica/diagnóstico por imagem , Diagnóstico Diferencial , Imagem de Tensor de Difusão/métodos , Feminino , Lobo Frontal/diagnóstico por imagem , Humanos , Masculino , Rede Nervosa/diagnóstico por imagem , Tálamo/diagnóstico por imagem
14.
Invest New Drugs ; 39(6): 1507-1522, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34195903

RESUMO

BACKGROUND: The purpose of this study was to identify ferroptosis-related genes (FRGs) associated with the prognosis of pancreatic cancer and to construct a prognostic model based on FRGs. METHODS: Based on pancreatic cancer data obtained from The Cancer Genome Atlas database, we established a prognostic model from 232 FRGs. A nomogram was constructed by combining the prognostic model and clinicopathological features. Gene Expression Omnibus datasets and tissue samples obtained from our center were utilized to validate the model. The relationship between risk score and immune cell infiltration was explored by CIBERSORT and TIMER. RESULTS: The prognostic model was established based on four FRGs (ENPP2, ATG4D, SLC2A1 and MAP3K5), and the risk score was demonstrated to be an independent risk factor in pancreatic cancer (HR 1.648, 95% CI 1.335-2.035, p < 0.001). Based on the median risk score, patients were divided into a high-risk group and a low-risk group. The low-risk group had a better prognosis than the high-risk group. In the high-risk group, patients treated with chemotherapy had a better prognosis. The nomogram showed that the model was the most important element. Gene set enrichment analysis identified three key pathways, namely, TGFß signaling, HIF signaling pathway and the adherens junction. The prognostic model may be associated with infiltration of immune cells such as M0 macrophages, M1 macrophages, CD4 + T cells and CD8 + T cells. CONCLUSION: The ferroptosis-related prognostic model can be employed to predict the prognosis of pancreatic cancer. Ferroptosis is an important marker, and immunotherapy may be a potential therapeutic target for pancreatic cancer.


Assuntos
Ferroptose/genética , Neoplasias Pancreáticas/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Biomarcadores Tumorais , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Macrófagos/metabolismo , Nomogramas , Prognóstico , Fatores de Risco , Fator de Crescimento Transformador beta/metabolismo
15.
Langmuir ; 37(23): 6847-6863, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34081473

RESUMO

Metal-organic frameworks (MOFs) are an emerging class of porous materials composed of organic linkers and metal centers/clusters. The integration of MOFs onto the solid surface as thin films/coatings has spurred great interest, thanks to leveraging control over their morphology (such as size- and shape-regulated crystals) and orientation, flexible processability, and easy recyclability. These aspects, in synergy, promise a wide range of applications, including but not limited to gas/liquid separations, chemical sensing, and electronics. Dozens of innovative methods have been developed to manipulate MOFs on various solid substrates for academic studies and potential industrial applications. Among the developed deposition methods, the liquid-phase epitaxial layer-by-layer (LPE-LbL) method has demonstrated its merits over precise control of the thickness, roughness, homogeneity, and orientations, among others. Herein, we discuss the major developments of surface-mounted MOFs (SURMOFs) in LbL process optimization, summarizing the SURMOFs' performance in different applications, and put forward our perspective on the future of SURMOFs in terms of advances in the formulation, applications, and challenges. Finally, future prospects and challenges with respect to SURMOFs growth will be discussed, keeping the focus on their widening applications.

16.
Exp Cell Res ; 396(1): 112244, 2020 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-32860814

RESUMO

PD1/PDL1 pathway plays a critical role in cancer immune responses. The immune checkpoint inhibitors of PD1/PDL1 have been well explored and developed for immunotherapies of solid tumors. Recently, various monoclonal antibodies targeting the PD1/PDL1 pathway have emerged and achieved remarkable success in clinical trials. However, challenges with these monoclonal antibodies have appeared during cancer therapies, including predictors of response, patient selection, and innate resistance. Thus, a competitive antagonist of native PD1/PDL1, with smaller size and lower side-effect, is required for future cancer therapies. In this study, we utilized a protein evolution system of phage-assisted continuous evolution (PACE) to evolve PD1 continuously. Our results indicated that the newly evolved PD1 bound to PDL1 with higher affinity. The interactome analysis further suggested that these evolved PD1s exhibited higher specificity with PDL1. Therefore, these evolved PD1s may be applied as a new tool for tumor immunotherapy.


Assuntos
Antígeno B7-H1/metabolismo , Evolução Molecular Direcionada/métodos , Receptor de Morte Celular Programada 1/metabolismo , Antígeno B7-H1/química , Antígeno B7-H1/genética , Sítios de Ligação , Clonagem Molecular , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica/efeitos dos fármacos , Genes Reporter , Células HEK293 , Humanos , Luciferases/genética , Luciferases/metabolismo , Modelos Moleculares , Mutagênese Sítio-Dirigida/métodos , Mutagênicos/farmacologia , Biblioteca de Peptídeos , Plasmídeos/química , Plasmídeos/metabolismo , Receptor de Morte Celular Programada 1/química , Receptor de Morte Celular Programada 1/genética , Ligação Proteica , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
17.
Gerontology ; 67(6): 718-728, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33853071

RESUMO

INTRODUCTION: Prospective memory (PM) is a multiphasic cognitive function important for autonomy and functional independence but is easily disrupted by pathological aging processes. Through cognitive simulation of perceptual experiences, mental imagery could be an effective compensatory strategy to enhance PM performance. Nevertheless, relevant research in individuals with amnestic mild cognitive impairment (MCI) has been limited, and the underlying mechanism of the therapeutic effect has not been sufficiently elucidated. The present study aimed to examine complex PM performances and the effect of mental imagery on each phase in older adults with MCI and to investigate the underlying cognitive mechanism from a process perspective. METHODS: Twenty-eight MCI and 32 normal aging controls completed a seminaturalistic PM task, in addition to a series of neuropsychological tests. Participants from each group were randomly assigned to a mental imagery condition or a standard repeated encoding condition before performing the PM task. Four indices were used to measure performance in the intention formation, intention retention, intention initiation, and intention execution phases of PM. Performances in each phase was compared between the 2 diagnostic groups and the 2 instruction conditions. RESULTS: The MCI group performed worse than the normal aging group in the intention formation and intention retention phases. The participants in the mental imagery condition performed significantly better than those in the standard condition during the intention formation, intention retention, and intention execution phases, regardless of the diagnostic group. Moreover, there was a significant interaction between the group and condition during intention retention, showing that people with MCI benefited even more from mental imagery than normal aging in this phase. Performance in the intention retention phase predicted performance in the intention initiation and intention execution phases. DISCUSSION: PM deficits in MCI mainly manifest during planning and retaining intentions. Mental imagery was able to promote performance in all but the initiation phase, although a trend for improvement was observed in this phase. The effects of mental imagery may be exerted in the intention retention phase by strengthening the PM cue-action bond, thereby facilitating the probability of intention initiation and bolstering fidelity to the original plan during intention execution.


Assuntos
Disfunção Cognitiva , Memória Episódica , Idoso , Disfunção Cognitiva/terapia , Humanos , Intenção , Transtornos da Memória/psicologia , Testes Neuropsicológicos
18.
Langenbecks Arch Surg ; 406(3): 691-701, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33507403

RESUMO

PURPOSE: To introduce sub-adventitial divestment technique (SDT), a procedure to remove the tumor while preserving the artery during curative pancreatectomy. Peri-operative safety profile was also evaluated. METHODS: In a single center consecutive series of pancreatectomy for pancreatic cancer, the outcome of patients who had pancreatectomy with SDT was compared to standard pancreatic surgery. RESULTS: From June 2014 to June 2016, 72 patients had pancreatectomy with SDT and 235 had standard surgery. Tumor stage was T4 in all 72 (100%) tumors removed using SDT compared to four (2%) with standard pancreatectomy (p < 0.001). All 72 (100%) tumors in the SDT group were stage III compared to 24 (10%) in the standard surgery group (p < 0.001). Both groups had a high proportion of poorly differentiated tumors (52 (72%) and 163 (69%) respectively) and perineural tumor invasion (62 (86%) and 186 (79%) respectively). R1 (< 1 mm) was found in 24 (86%) of 28 tumors in the SDT group, and in 72 (60%) out of 120 standard pancreatectomy tumors (p = 0.01). Complications occurred in 29 (40%) of the SDT group and in 88 (37%) of the standard group. The in-hospital mortality was four (6%) in the SDT group and one (0.4%) in the standard group (p = 0.01), with a 90-day mortality of 5 (8%)/60 and 6 (3%)/209 (p = 0.07) respectively. CONCLUSIONS: The sub-adventitial divestment technique appeared to be an effective surgical technique to remove the tumor while preserving the artery. This approach warrants further validation in prospective studies.


Assuntos
Pancreatectomia , Neoplasias Pancreáticas , Artérias , Humanos , Neoplasias Pancreáticas/cirurgia , Estudos Prospectivos , Estudos Retrospectivos
19.
J Dairy Sci ; 104(6): 6415-6430, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33741171

RESUMO

Depression is a prevalent, stress-related mental disorder that can lead to serious psychiatric diseases with morbidity and high mortality. Although some functional fermented dairy drinks have promising anxiolytic and antidepressant effects, the mechanism is still not clear. To determine the antidepressant-like effect and the potential molecule mechanism of kefir peptides (KP), various behavioral tests, including the elevated plus maze test, open field test, forced swimming test, and tail suspension test, were used. Administration of 150 mg/kg KP in mice reduced the duration of immobility in the forced swimming test and tail suspension test, elevated the time spent in the open arm and center zone in the elevated plus maze test, and increased the total distance traveled, average speed, and time spent in the center zone in the open field test compared with the mock group. These results indicated that KP dramatically ameliorated the depression-like behaviors. Kefir peptides were further isolated and identified using high-performance liquid chromatography and liquid chromatography-tandem mass spectrometry, from which 3 peptides were identified and designated KFP-1, KFP-3, and KFP-5. Among these peptides, administration of KFP-3 (15 AA residues) remarkably decreased immobility time in the forced swimming test and increased mobility time in the tail suspension test. Therefore, KFP-3 may be the major active peptide with antidepressant activity in KP. Overexpression of brain-derived neurotrophic factor, phosphorylated tropomyosin receptor kinase B, and phosphorylated ERK1/2 protein levels could be detected in the hippocampus under KP administration. Therefore, we suggest that KP improves depressive-like behaviors by activating the brain-derived neurotrophic factor-phosphorylated tropomyosin receptor kinase B signaling pathway. Kefir peptides may serve as a new type of antidepressant dairy product and may provide potent antidepressant effects for clinical use.


Assuntos
Kefir , Doenças dos Roedores , Animais , Antidepressivos , Fator Neurotrófico Derivado do Encéfalo , Depressão/tratamento farmacológico , Modelos Animais de Doenças , Glicoproteínas de Membrana , Camundongos , Peptídeos , Proteínas Tirosina Quinases , Estresse Psicológico
20.
Angew Chem Int Ed Engl ; 60(14): 7553-7558, 2021 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-33350565

RESUMO

The landscape of possible polymorphs for some metal-organic frameworks (MOFs) can pose a challenge for controlling the outcome of their syntheses. Demonstrated here is the use of a template to control in the vapor-assisted formation of zeolitic imidazolate framework (ZIF) powders and thin films. Introducing a small amount of either ethanol or dimethylformamide vapor during the reaction between ZnO and 4,5-dichloroimidazole vapor results in the formation of the porous ZIF-71 phase, whereas other conditions lead to the formation of the dense ZIF-72 phase or amorphous materials. Time-resolved in situ small-angle X-ray scattering reveals that the porous phase is metastable and can be transformed into its dense polymorph. This transformation is avoided through the introduction of template vapor. The porosity of the resulting ZIF powders and films was studied by N2 and Kr physisorption, as well as positron annihilation lifetime spectroscopy. The templating principle was demonstrated for other members of the ZIF family as well, including the ZIF-7 series, ZIF-8_Cl, and ZIF-8_Br.

SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa