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2.
J Cell Sci ; 136(20)2023 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-37737012

RESUMO

All endocytosis and exocytosis in the African trypanosome Trypanosoma brucei occurs at a single subdomain of the plasma membrane. This subdomain, the flagellar pocket, is a small vase-shaped invagination containing the root of the single flagellum of the cell. Several cytoskeleton-associated multiprotein complexes are coiled around the neck of the flagellar pocket on its cytoplasmic face. One of these, the hook complex, was proposed to affect macromolecule entry into the flagellar pocket lumen. In previous work, knockdown of T. brucei (Tb)MORN1, a hook complex component, resulted in larger cargo being unable to enter the flagellar pocket. In this study, the hook complex component TbSmee1 was characterised in bloodstream form T. brucei and found to be essential for cell viability. TbSmee1 knockdown resulted in flagellar pocket enlargement and impaired access to the flagellar pocket membrane by surface-bound cargo, similar to depletion of TbMORN1. Unexpectedly, inhibition of endocytosis by knockdown of clathrin phenocopied TbSmee1 knockdown, suggesting that endocytic activity itself is a prerequisite for the entry of surface-bound cargo into the flagellar pocket.


Assuntos
Trypanosoma brucei brucei , Trypanosoma , Trypanosoma/metabolismo , Endocitose/fisiologia , Trypanosoma brucei brucei/metabolismo , Membrana Celular/metabolismo , Cílios/metabolismo , Flagelos/metabolismo , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo
3.
PLoS Pathog ; 19(6): e1011438, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37276216

RESUMO

Cold shock proteins are members of a family of DNA- and RNA-binding proteins with one or more evolutionarily conserved cold shock domain (CSD). These proteins have a wide variety of biological functions, including DNA-damage repair, mRNA stability, and regulation of transcription, splicing and translation. We previously identified two CSD containing proteins, CSD1 and CSD2, in the protozoan parasite Trypanosoma brucei to be required for RBP6-driven metacyclic production, albeit at different steps of the developmental program. During metacyclogenesis T. brucei undergoes major morphological and metabolic changes that culminate in the establishment of quiescent metacyclic parasites and the acquisition of mammalian infectivity. To investigate the specific role of CSD1 and CSD2 in this process, we ectopically expressed CSD1 or CSD2 in non-infectious procyclic parasites and discovered that each protein is sufficient to produce infectious metacyclic parasites in 24 hours. Domain truncation assays determined that the N-terminal domain, but not the C-terminal domain, of CSD1 and CSD2 was required for metacyclic development. Furthermore, conserved amino acid residues in the CSD of CSD1 and CSD2, known to be important for binding nucleic acids, were found to be necessary for metacyclic production. Using single-end enhanced crosslinking and immunoprecipitation (seCLIP) we identified the specific binding motif of CSD1 and CSD2 as "ANACAU" and the bound mRNAs were enriched for biological processes, including lipid metabolism, microtubule-based movement and nucleocytoplasmic transport that are likely involved in the transition to bloodstream form-like cells.


Assuntos
Trypanosoma brucei brucei , Animais , Trypanosoma brucei brucei/metabolismo , Proteínas e Peptídeos de Choque Frio/metabolismo , Resposta ao Choque Frio , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Mamíferos
4.
J Allergy Clin Immunol ; 153(4): 954-968, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38295882

RESUMO

Studies of asthma and allergy are generating increasing volumes of omics data for analysis and interpretation. The National Institute of Allergy and Infectious Diseases (NIAID) assembled a workshop comprising investigators studying asthma and allergic diseases using omics approaches, omics investigators from outside the field, and NIAID medical and scientific officers to discuss the following areas in asthma and allergy research: genomics, epigenomics, transcriptomics, microbiomics, metabolomics, proteomics, lipidomics, integrative omics, systems biology, and causal inference. Current states of the art, present challenges, novel and emerging strategies, and priorities for progress were presented and discussed for each area. This workshop report summarizes the major points and conclusions from this NIAID workshop. As a group, the investigators underscored the imperatives for rigorous analytic frameworks, integration of different omics data types, cross-disciplinary interaction, strategies for overcoming current limitations, and the overarching goal to improve scientific understanding and care of asthma and allergic diseases.


Assuntos
Asma , Hipersensibilidade , Estados Unidos , Humanos , National Institute of Allergy and Infectious Diseases (U.S.) , Hipersensibilidade/genética , Asma/etiologia , Genômica , Proteômica , Metabolômica
5.
Radiology ; 311(1): e230459, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38563669

RESUMO

Background Microwave ablation (MWA) is currently under preliminary investigation for the treatment of multifocal papillary thyroid carcinoma (PTC) and has shown promising treatment efficacy. Compared with surgical resection (SR), MWA is minimally invasive and could preserve thyroid function. However, a comparative analysis between MWA and SR is warranted to draw definitive conclusions. Purpose To compare MWA and SR for preoperative US-detected T1N0M0 multifocal PTC in terms of overall and 1-, 3-, and 5-year progression-free survival rates and complication rates. Materials and Methods In this retrospective study, 775 patients with preoperative US-detected T1N0M0 multifocal PTC treated with MWA or SR across 10 centers between May 2015 and December 2021 were included. Propensity score matching (PSM) was performed for patients in the MWA and SR groups, followed by comparisons between the two groups. The primary outcomes were overall and 1-, 3-, and 5-year progression-free survival (PFS) rates and complication rates. Results After PSM, 229 patients (median age, 44 years [IQR 36.5-50.5 years]; 179 female) in the MWA group and 453 patients (median age, 45 years [IQR 37-53 years]; 367 female) in the SR group were observed for a median of 20 months (range, 12-74 months) and 26 months (range, 12-64 months), respectively. MWA resulted in less blood loss, shorter incision length, and shorter procedure and hospitalization durations (all P < .001). There was no evidence of differences in overall and 1-, 3-, or 5-year PFS rates (all P > .05) between MWA and SR (5-year rate, 77.2% vs 83.1%; P = .36) groups. Permanent hoarseness (2.2%, P = .05) and hypoparathyroidism (4.0%, P = .005) were encountered only in the SR group. Conclusion There was no evidence of a significant difference in PFS rates between MWA and SR for US-detected multifocal T1N0M0 PTC, and MWA resulted in fewer complications. Therefore, MWA is a feasible option for selected patients with multifocal T1N0M0 PTC. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Georgiades in this issue.


Assuntos
Micro-Ondas , Neoplasias da Glândula Tireoide , Humanos , Feminino , Adulto , Pessoa de Meia-Idade , Micro-Ondas/uso terapêutico , Estudos Retrospectivos , Câncer Papilífero da Tireoide/diagnóstico por imagem , Câncer Papilífero da Tireoide/cirurgia , Hospitalização , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Neoplasias da Glândula Tireoide/cirurgia
6.
Eur Radiol ; 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38546792

RESUMO

OBJECTIVE: To evaluate the efficacy, safety, and improvement of symptoms by ultrasound-guided microwave ablation (MWA) for patients with large benign thyroid nodules (BTNs). METHODS: Eighty-seven patients with 87 BTNs (≥ 4 cm) treated with MWA between April 2015 and March 2021 were enrolled in this retrospective multicenter study, with clinical and ultrasound examinations performed at the 1st, 3rd, 6th, and 12th months. A multivariable linear mixed effects model was employed to explore the alterations in volume and volume reduction ratio (VRR), as well as the potential factors associated with VRR. RESULTS: The mean age of the 87 patients was 45.69 ± 14.21 years (range 18-76 years), and the ratio of men to women was 1:4.8. The mean volumes were much decreased at the 12th month after ablation compared to the initial volumes (p < .001). The mean VRR was 76.09% at the 12th month. The technique efficacy (VRR > 50%) was 90.80% at the 12th month. A multivariate analysis revealed that VRR was related to the initial volume (p = .015), annular flow (p = .010), and nodule composition (p = .024). The mean symptomatic score decreased from 4.40 ± 0.28 to 0.26 ± 0.06 at the 12th month (p < .001). At the same time, the mean cosmetic score decreased from 3.22 ± 0.10 to 1.31 ± 0.08 (p < .001). CONCLUSION: MWA could serve as a safe and effective therapy for large BTNs, significantly reducing the volume of BTNs and significantly improving compressive symptoms and appearance problems. CLINICAL RELEVANCE STATEMENT: Microwave ablation could serve as a safe and effective therapy for large benign thyroid nodules, leading to significant volume reduction and satisfied symptom and cosmetic alleviation period. KEY POINTS: • This multicenter study investigated the feasibility and safety of microwave ablation for large benign thyroid nodules. • After ablation, the nodule volume was significantly reduced, and patients' symptoms and appearance problems were significantly improved. • Microwave ablation is feasible for large benign thyroid nodules and has been a supplement treatment.

7.
J Vasc Interv Radiol ; 35(7): 1004-1011, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38537738

RESUMO

PURPOSE: To investigate the feasibility, safety, and clinical outcomes of image-guided thermal ablation in patients with hepatic epithelioid hemangioendothelioma (HEHE). MATERIALS AND METHODS: This was a multicenter retrospective investigation of 18 patients (43.9 years [SD ± 14.8]; 6 men) who underwent image-guided thermal ablation for HEHE between January 2013 and February 2023. A total of 31 ablation sessions (24 involving microwave ablation and 7 involving radiofrequency ablation) were evaluated. The rates of technical success, adverse events, and outcomes were assessed. The Kaplan‒Meier method was used to estimate progression-free survival (PFS) and overall survival (OS) rates. The risk factors affecting PFS were investigated using Cox proportional hazard regression analysis. RESULTS: The technical success rate was 93.5% (29/31). No major adverse events occurred. Local tumor progression occurred after 2 sessions (6.5%, 2/31), and intrahepatic distant metastasis occurred after 16 sessions (51.6%, 16/31). During the medium follow-up time of 37.2 months (range, 3-117 months), the OS and PFS rates were 87.6% and 62.2%, respectively, at 1 year; 75.5% and 37.4%, respectively, at 3 years; and 75.5% and 37.4%, respectively, at 5 years. The median OS and PFS were 90.5 months (95% CI: 68.1-112.8) and 23.8 months (95% CI: 15.4-32.2), respectively. According to the multivariate analysis, a larger tumor size (P = .026) was associated with shorter PFS. CONCLUSIONS: Image-guided thermal ablation is a feasible and safe treatment option for patients with HEHE that resulted in local tumor control and a favorable long-term prognosis.


Assuntos
Estudos de Viabilidade , Hemangioendotelioma Epitelioide , Neoplasias Hepáticas , Intervalo Livre de Progressão , Humanos , Masculino , Neoplasias Hepáticas/cirurgia , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/diagnóstico por imagem , Feminino , Pessoa de Meia-Idade , Hemangioendotelioma Epitelioide/cirurgia , Hemangioendotelioma Epitelioide/patologia , Hemangioendotelioma Epitelioide/mortalidade , Hemangioendotelioma Epitelioide/diagnóstico por imagem , Estudos Retrospectivos , Adulto , Fatores de Risco , Fatores de Tempo , Ablação por Radiofrequência/efeitos adversos , Ablação por Radiofrequência/mortalidade , Micro-Ondas/uso terapêutico , Micro-Ondas/efeitos adversos , Progressão da Doença , Adulto Jovem , Idoso , China , Resultado do Tratamento
8.
J Am Chem Soc ; 145(31): 17232-17241, 2023 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-37493612

RESUMO

Supramolecular radical chemistry is an emerging area bridging supramolecular chemistry and radical chemistry, and the integration of radicals into the supramolecular architecture offers a new dimension for tuning their structures and functions. Although various efforts have been devoted to the fabrication of supramolecular junctions, the charge transport characterization through the supramolecular radicals remained unexplored due to the challenges in creating supramolecular radicals at the single-molecule level. Here, we demonstrate the fabrication and charge transport investigation of a supramolecular radical junction using the electrochemical scanning tunneling microscope-based break junction (EC-STM-BJ) technique. We found that the conductance of a supramolecular radical junction was more than 1 order of magnitude higher than that of a supramolecular junction without a radical and even higher than that of a fully conjugated oligophenylenediamine molecule with a similar length. The combined experimental and theoretical investigations revealed that the radical increased the binding energy and decreased the energy gap in the supramolecular radical junction, which leads to the near-resonant transport through the supramolecular radical. Our work demonstrated that the supramolecular radical can provide not only strong binding but also efficient electrical coupling between building blocks, which provides new insights into supramolecular radical chemistry and new materials with supramolecular radicals.

9.
Small ; 19(15): e2207242, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36631289

RESUMO

Limited comprehension of the reaction mechanism has hindered the development of catalysts for CO2 reduction reactions (CO2 RR). Here, the bimetallic AgCu nanocatalyst platform is employed to understand the effect of the electronic structure of catalysts on the selectivity and activity for CO2 electroreduction to CO. The atomic arrangement and electronic state structure vary with the atomic ratio of Ag and Cu, enabling tunable d-band centers to optimize the binding strength of key intermediates. Density functional theory calculations confirm that the variation of Cu content greatly affects the free energy of *COOH, *CO (intermediate of CO), and *H (intermediates of H2 ), which leads to the change of the rate-determining step. Specifically, Ag96 Cu4 reduces the free energy of the formation of *COOH while maintaining a relatively high theoretical overpotential for hydrogen evolution reaction(HER), thus achieving the best CO selectivity. While Ag70 Cu30 shows relatively low formation energy of both *COOH and *H, the compromised thermodynamic barrier and product selectivity allows Ag70 Cu30 the best CO partial current density. This study realizes the regulation of the selectivity and activity of electrocatalytic CO2 to CO, which provides a promising way to improve the intrinsic performance of CO2 RR on bimetallic AgCu.

10.
PLoS Pathog ; 17(8): e1009329, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34339455

RESUMO

The flagellar pocket (FP) is the only endo- and exocytic organelle in most trypanosomes and, as such, is essential throughout the life cycle of the parasite. The neck of the FP is maintained enclosed around the flagellum via the flagellar pocket collar (FPC). The FPC is a macromolecular cytoskeletal structure and is essential for the formation of the FP and cytokinesis. FPC biogenesis and structure are poorly understood, mainly due to the lack of information on FPC composition. To date, only two FPC proteins, BILBO1 and FPC4, have been characterized. BILBO1 forms a molecular skeleton upon which other FPC proteins can, theoretically, dock onto. We previously identified FPC4 as the first BILBO1 interacting partner and demonstrated that its C-terminal domain interacts with the BILBO1 N-terminal domain (NTD). Here, we report by yeast two-hybrid, bioinformatics, functional and structural studies the characterization of a new FPC component and BILBO1 partner protein, BILBO2 (Tb927.6.3240). Further, we demonstrate that BILBO1 and BILBO2 share a homologous NTD and that both domains interact with FPC4. We have determined a 1.9 Å resolution crystal structure of the BILBO2 NTD in complex with the FPC4 BILBO1-binding domain. Together with mutational analyses, our studies reveal key residues for the function of the BILBO2 NTD and its interaction with FPC4 and evidenced a tripartite interaction between BILBO1, BILBO2, and FPC4. Our work sheds light on the first atomic structure of an FPC protein complex and represents a significant step in deciphering the FPC function in Trypanosoma brucei and other pathogenic kinetoplastids.


Assuntos
Citocinese , Citoesqueleto/metabolismo , Flagelos/metabolismo , Organelas/metabolismo , Proteínas de Protozoários/química , Proteínas de Protozoários/metabolismo , Trypanosoma brucei brucei/metabolismo , Sequência de Aminoácidos , Cristalografia por Raios X , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas , Homologia de Sequência , Técnicas do Sistema de Duplo-Híbrido
11.
Cell Mol Neurobiol ; 43(1): 193-204, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35137327

RESUMO

Glioma is the most common primary tumor of the central nervous system and normally should be treated by synthetic therapy, mainly with surgical operation assisted by radiotherapy and chemotherapy; however, the therapeutic effect has not been satisfactory, and the 5-year survival rates of anaplastic glioma and glioblastoma are 29.7% and 5.5%, respectively. To identify a more efficient strategy to treat glioma, in recent years, the influence of the inflammatory microenvironment on the progression of glioma has been studied. Various immunophenotypes exist in microglial cells, each of which has a different functional property. In this review, references about the phenotypic conversion of microglial cell polarity in the microenvironment were briefly summarized, and the differences in polarized state and function, their influences on glioma progression under different physiological and pathological conditions, and the interactive effects between the two were mainly discussed. Certain signaling molecules and regulatory pathways involved in the microglial cell polarization process were investigated, and the feasibility of targeted regulation of microglial cell conversion to an antitumor phenotype was analyzed to provide new clues for the efficient auxiliary treatment of neural glioma.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Glioma , Humanos , Microglia/metabolismo , Glioma/patologia , Glioblastoma/patologia , Transdução de Sinais , Neoplasias Encefálicas/genética , Microambiente Tumoral
12.
Eur Radiol ; 33(12): 8727-8735, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37466709

RESUMO

OBJECTIVES: Microwave ablation (MWA) has been widely used for unifocal papillary thyroid carcinoma (U-PTC) and has recently been preliminarily used in multifocal papillary thyroid carcinoma (M-PTC). However, the efficacy and safety of MWA for M-PTC have not been investigated in large samples. The aim of the present study was to evaluate the efficacy and safety of MWA for M-PTC and compare them with MWA for U-PTC. MATERIALS AND METHODS: This retrospective multicentre study enrolled 504 patients (376 females) who underwent MWA for U-PTC (340 cases) or M-PTC (164 cases) from Jan 2015 to Dec 2020. The median age of the patients was 43 years (age range, 20-80 years). Propensity score matching (PSM) was used to balance the baseline characteristics between M-PTC group and U-PTC group. The tumour progression, tumour disappearance, and complication rates were compared between the two groups. RESULTS: The complete ablation was achieved in all enrolled cases in one session. According to the statistical results, no significant differences were shown in tumour progression-free survival (p  = 0.29) or cumulative tumour progression rate (6.7% vs. 4.3%, p  = 0.33) between the M-PTC and U-PTC groups during the follow-up time. However, the tumour disappearance rate in the M-PTC group was lower in the U-PTC group (40.9% vs. 62.8%, p < 0.001), and tumour disappearance was slower in the M-PTC group (p < 0.001). The complication rate showed no significant difference (3.0% vs. 4.9%, p  = 0.571). CONCLUSIONS: MWA is an effective and safe treatment for selected patients with M-PTC, and the prognosis is similar to that of U-PTC. CLINICAL RELEVANCE STATEMENT: The present study provided evidence that compared with unifocal papillary thyroid cancer, microwave ablation could also treat multifocal T1N0M0 papillary thyroid cancer safely with similar clinical outcome, which could promote the application of minimally invasive treatment for papillary thyroid cancer. KEY RESULTS: • Microwave ablation for multifocal and unifocal T1N0M0 papillary thyroid carcinoma had similar tumour progression rates after propensity score matching (6.7% vs. 4.3%, p = 0.33). • The tumour disappearance rate in the multifocal group was lower than that in the unifocal group (40.9% vs. 62.8%, p < 0.001), and tumour disappearance was slower in the multifocal group (p < 0.001). • Tumour size, number, and location were not risk factors for tumour progression in the multifocal papillary thyroid cancer group.


Assuntos
Carcinoma Papilar , Neoplasias da Glândula Tireoide , Feminino , Humanos , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Câncer Papilífero da Tireoide/cirurgia , Câncer Papilífero da Tireoide/patologia , Neoplasias da Glândula Tireoide/cirurgia , Neoplasias da Glândula Tireoide/patologia , Estudos Retrospectivos , Resultado do Tratamento , Micro-Ondas/uso terapêutico , Carcinoma Papilar/cirurgia , Carcinoma Papilar/patologia
13.
Environ Res ; 237(Pt 2): 117029, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37659645

RESUMO

The distribution of seasonal precipitation would profoundly affect the dynamics of carbon fluxes in terrestrial ecosystems. However, little is known about the impacts of extreme precipitation and size events on ecosystem carbon cycle when compared to the effects of average precipitation amount. The study involved an analysis of carbon fluxes and water exchange using the eddy covariance and chamber based techniques during the growing seasons of 2015-2017 in Bayan, Mongolia and 2019-2021 in Hulunbuir, Inner Mongolia, respectively. The components of carbon fluxes and water exchange at each site were normalized to evaluate of relative response among carbon fluxes and water exchange. The investigation delved into the relationship between carbon fluxes and extreme precipitation over five gradients (control, dry spring, dry summer, wet spring and wet summer) in Hulunbuir meadow steppe and distinct four precipitation sizes (0.1-2, 2-5, 5-10, and 10-25 mm d-1) in Bayan meadow steppe. The wet spring and summer showed the greatest ecosystem respiration (ER) relative response values, 76.2% and 73.5%, respectively, while the dry spring (-16.7%) and dry summer (14.2%) showed the lowest values. Gross primary production (GPP) relative response improved with wet precipitation gradients, and declined with dry precipitation gradients in Hulunbuir meadow steppe. The least value in net ecosystem CO2 exchange (NEE) was found at 10-25 mm d-1 precipitation size in Bayan meadow steppe. Similarly, the ER and GPP increased with size of precipitation events. The structural equation models (SEM) satisfactorily fitted the data (χ2 = 43.03, d.f. = 11, p = 0.215), with interactive linkages among soil microclimate, water exchange and carbon fluxes components regulating NEE. Overall, this study highlighted the importance of extreme precipitation and event size in influencing ecosystem carbon exchange, which is decisive to further understand the carbon cycle in meadow steppes.

14.
Biotechnol Appl Biochem ; 70(2): 688-696, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35932185

RESUMO

The bacterium Caulobacter crescentus secretes an adhesive polysaccharide called holdfast, which is the known strongest underwater adhesive in nature. The deacetylase encoded by hfs (holdfast synthesis) H gene is a key factor affecting the adhesion of holdfast. Its structure and function are not yet clear, and whether other polysaccharide deacetylases exist in C. crescentus is still unknown. The screening of both HfsH and its structural analogue as well as their purification from the artificial expression products of Escherichia coli is the first step to clarify these questions. Here, we determined the conserved domains of HfsH via sequence alignment among carbohydrate esterase family 4 enzymes and screened out its structural analogue (CC_2574) in C. crescentus. The recombinant HfsH and CC_2574 were effectively expressed in E. coli. Both of them were purified by chromatography from their corresponding productions in E. coli and were then functionally analyzed. The results indicated that a high deacetylase activity (61.8 U/mg) was observed in recombinant HfsH but not in CC_2574, which suggesting that HfsH might be the irreplaceable gene mediating adhesion of holdfast in C. crescentus. Moreover, the divalent metal ions Zn2+ , Mg2+ , and Mn2+ could promote the activity of recombinant HfsH at the concentration from 0.05 to 1 mM, but inhibit its activity when the concentration exceeds 1 mM. In sum, our study first realized the artificial production of polysaccharide deacetylase HfsH and its structural analogue, and further explored their functions, both of which laid the foundation for the development of new adhesive materials.


Assuntos
Aderência Bacteriana , Caulobacter crescentus , Aderência Bacteriana/genética , Caulobacter crescentus/genética , Caulobacter crescentus/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Hormônio Foliculoestimulante Humano/metabolismo , Polissacarídeos/metabolismo , Proteínas de Bactérias/genética
15.
J Microencapsul ; 40(3): 157-170, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36825613

RESUMO

AIMS: The aim of this study is to develop a liposome that could exert unparalleled antioxidant effects. In the present study, a vitamin C (VC)/vitamin E (VE)-co-loaded multivesicular liposome (VCVE-MVL) was constructed. METHODS: Vitamins were encapsulated in soybean phosphatidylcholine (SPC) and cholesterol (CHO) by multi-emulsification method. The concentration of VC was determined by Fast Blue method. The concentration of VE was determined by high performance liquid chromatography (HPLC). Vitamin antioxidant capacity in vitro and in vivo was determined using ß-carotene bleaching. RESULTS: VCVE-MVL with particle diameter of 848.55 ± 0.29 nm and SPAN of 0.16 ± 0.11 were obtained. The encapsulation efficiency of VC reached 48.51% (w/w)±0.15. Compared with VC/VE solution, VCVE-MVL had a higher permeation efficiency. In addition, the in vitro and ex-vivo antioxidant tests verified the adequate antioxidant activity of VCVE-MVL. CONCLUSIONS: In conclusion, the antioxidant synergistic system we constructed and demonstrated its potential applications in the cosmetics industry.


Assuntos
Antioxidantes , Vitamina E , Antioxidantes/farmacologia , Antioxidantes/química , Ácido Ascórbico , Lipossomos/química , Vitaminas
16.
Ocean Coast Manag ; 232: 106427, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36440375

RESUMO

In the post COVID-19 pandemic era, collusion strategy has been attempted to confront fierce market competition in container shipping supply chains. Three typical collusion scenarios are constructed as follows: i) none of the two pairs of shipping chains colludes; ii) both pairs collude; and iii) only one pair colludes. This paper developed a two-stage game model to study the optimal strategies of the container terminals and corresponding liner companies. The container ports set terminal handling charge (THC) to pursue optimal profits at the first stage, and then liner companies choose freight rate to obtain corresponding optimal profits at the second stage. Further, we analyzed the collusive incentives of the THC difference between heterogeneous terminals and the impact of the freight rate difference between heterogeneous container liners. In particular, the possibility of deviation from collusion and the decision of capacity expansion of container terminal are discussed through theoretical analysis. The results show that the optimal THC of a container terminal and freight rate of a container liner are both highly related to the capacity of the container terminal, which is profoundly influenced by the different structures of its collusion. Finally, the empirical study proves the theoretical result and the implications of port governance are subsequently discussed.

17.
Neuroimage ; 260: 119483, 2022 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-35842098

RESUMO

Salient stimuli can capture attention in a bottom-up manner; however, this attentional capture can be suppressed in a top-down manner. It has been shown that individuals with high working memory capacity (WMC) can suppress salient­but-irrelevant distractors better than those with low WMC; however, neural substrates underlying this difference remain unclear. To examine this, participants with high or low WMC (high-/low-WMC, n = 44/44) performed a visual search task wherein a color singleton item served as a salient distractor, and underwent structural and resting-state functional magnetic resonance imaging scans. Behaviorally, the color singleton distractor generally reduced the reaction time (RT). This RT benefit (ΔRT) was higher in the high-WMC group relative to the low-WMC group, indicating the superior distractor suppression ability of the high-WMC group. Moreover, leveraging voxel-based morphometry analysis, gray matter morphology (volume and deformation) in the ventral attention network (VAN) was found to show the same, positive associations with ΔRT in both WMC groups. However, correlations of the opposite sign were found between ΔRT and gray matter morphology in the frontoparietal (FPN)/default mode network (DMN) in the two WMC groups. Furthermore, resting-state functional connectivity analysis centering on regions with a structural-behavioral relationship found that connections between the left orbital and right superior frontal gyrus (hubs of DMN and VAN, respectively) was correlated with ΔRT in the high-WMC group (but not in the low-WMC group). Collectively, our work present shared and distinct neuroanatomical substrates of distractor suppression in high- and low-WMC individuals. Furthermore, intrinsic connectivity of the brain network hubs in high-WMC individuals may account for their superior ability in suppressing salient distractors.


Assuntos
Encéfalo , Memória de Curto Prazo , Encéfalo/diagnóstico por imagem , Córtex Cerebral , Humanos , Imageamento por Ressonância Magnética , Tempo de Reação
18.
J Am Chem Soc ; 144(34): 15689-15697, 2022 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-35930760

RESUMO

Stacking interactions are of significant importance in the fields of chemistry, biology, and material optoelectronics because they determine the efficiency of charge transfer between molecules and their quantum states. Previous studies have proven that when two monomers are π-stacked in series to form a dimer, the electrical conductance of the dimer is significantly lower than that of the monomer. Here, we present a strong opposite case that when two anthanthrene monomers are π-stacked to form a dimer in a scanning tunneling microscopic break junction, the conductance increases by as much as 25 in comparison with a monomer, which originates from a room-temperature quantum interference. Remarkably, both theory and experiment consistently reveal that this effect can be reversed by changing the connectivity of external electrodes to the monomer core. These results demonstrate that synthetic control of connectivity to molecular cores can be combined with stacking interactions between their π systems to modify and optimize charge transfer between molecules, opening up a wide variety of potential applications ranging from organic optoelectronics and photovoltaics to nanoelectronics and single-molecule electronics.


Assuntos
Grafite , Condutividade Elétrica , Eletrodos , Eletrônica , Microscopia de Tunelamento , Polímeros
19.
Cell Biol Toxicol ; 38(1): 185-201, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-33677747

RESUMO

An increased lipopolysaccharide (LPS) level in patients with cirrhosis induced the dysregulation of sterol regulatory element-binding transcription factor 2 (SREBF2), which participated in the modulation of tumor inflammatory microenvironment. However, the role of SREBF2 in the LPS-induced injury of portal vein endothelium was scarcely reported. This study aimed to investigate the effects of SREBF2 on the LPS-induced injury to endothelial cells (ECs) in vitro and in vivo and explore the underlying mechanism. In this study, we found that LPS increased SREBF2 expression through activating the TLR4/JNK/c-Jun pathway and suppressed UBE2I-mediated SREBF2 sumoylation to enhance its transcriptional activity. The dysregulation of SREBF2 induced ER stress by increasing the intracellular cholesterol level and facilitated Bax expression to cause additional damage to LPS-induced ECs. As a potential intervention, miR590-3p negatively regulated SREBF2 expression and upregulated UBE2I expression by targeting TLR4, thus alleviating LPS-induced injury. These results suggest that LPS-induced SREBF2 triggered ER stress and promoted Bax expression to injure ECs, which was reversed by miR590-3p. The mechanisms of SREBF2 mediated LPS-induced endothelial injury of portal vein, which might be the therapeutic target for PVT development in cirrhosis patients. 1. LPS promoted SREBF2 expression by activating the TLR4/JNK/c-Jun pathway and suppressed UBE2I-mediated SREBF2 sumoylation to upregulate SREBF2 transcriptional activity 2. SREBF2-mediated ER stress and Bax expression involved in LPS-induced EC injury 3. miR590-3p decreased SREBF2 expression by targeting TLR4 and mitigated LPS-induced EC injury.


Assuntos
Estresse do Retículo Endoplasmático , Lipopolissacarídeos , Células Endoteliais/metabolismo , Endotélio/metabolismo , Humanos , Lipopolissacarídeos/farmacologia , Cirrose Hepática , Proteína de Ligação a Elemento Regulador de Esterol 2 , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo , Proteína X Associada a bcl-2/genética
20.
Bioorg Chem ; 119: 105469, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34915285

RESUMO

Targeting EGFR and HER-2 is an essential direction for cancer treatment. Here, a series of N-(1,3,4-thiadiazol-2-yl)benzamide derivatives containing a 6,7-methoxyquinoline structure was designed and synthesized to serve as EGFR/HER-2 dual-target inhibitors. The kinase assays verified that target compounds could inhibit the kinase activity of EGFR and HER-2 selectively. The results of CCK-8 and 3D cell viability assays confirmed that target compounds had excellent anti-proliferation ability against breast cancer cells (MCF-7 and SK-BR-3) and lung cancer cells (A549 and H1975), particularly against SK-BR-3 cells, while the inhibitory effect on healthy breast cells (MCF-10A) and lung cells (Beas-2B) was weak. Among them, the hit compound YH-9 binded to EGFR and HER-2 stably in molecular dynamics studies. Further studies found thatYH-9could induce the release of cytochrome c and inhibit proliferation by promoting ROS expression in SK-BR-3 cells. Moreover,YH-9could diminish the secretion of VEGF and bFGF factors in SK-BR-3 cells, then inhibited tube formation and angiogenesis. Notably,YH-9could effectively inhibit breast cancer growth and angiogenesis with little toxicity in the SK-BR-3 cell xenograft model. Taken together,in vitroandin vivoresults revealed that YH-9 had high drug potential as a dual-target inhibitor of EGFR/HER-2 to inhibit breast cancer growth and angiogenesis.


Assuntos
Antineoplásicos/farmacologia , Benzamidas/farmacologia , Descoberta de Drogas , Neovascularização Patológica/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Tiadiazóis/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Benzamidas/síntese química , Benzamidas/química , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/metabolismo , Humanos , Estrutura Molecular , Neovascularização Patológica/patologia , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Receptor ErbB-2/antagonistas & inibidores , Receptor ErbB-2/metabolismo , Relação Estrutura-Atividade , Tiadiazóis/síntese química , Tiadiazóis/química , Células Tumorais Cultivadas
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