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1.
Environ Sci Technol ; 58(23): 10140-10148, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38781353

RESUMO

Anammox bacteria performed the reaction of NH4+ and NO with hydrazine synthase to produce N2H4, followed by the decomposition of N2H4 with hydrazine dehydrogenase to generate N2. Ferroheme/ferriheme, which serves as the active center of both hydrazine synthase and hydrazine dehydrogenase, is thought to play a crucial role in the synthesis and decomposition of N2H4 during Anammox due to its high redox activity. However, this has yet to be proven and the exact mechanisms by which ferroheme/ferriheme is involved in the Anammox process remain unclear. In this study, abiotic and biological assays confirmed that ferroheme participated in NH4+ and NO reactions to generate N2H4 and ferriheme, and the produced N2H4 reacted with ferriheme to generate N2 and ferroheme. In other words, the ferroheme/ferriheme cycle drove the continuous reaction between NH4+ and NO. Raman, ultraviolet-visible spectroscopy, and X-ray absorption fine structure spectroscopy confirmed that ferroheme/ferriheme is involved in the synthesis and decomposition of N2H4 via the core FeII/FeIII cycle. The mechanism of ferroheme/ferriheme participation in the synthesis and decomposition of N2H4 was proposed by density functional theory calculations. These findings revealed for the first time the heme electron transfer mechanisms, which are of great significance for deepening the understanding of Anammox.


Assuntos
Hidrazinas , Oxirredução , Hidrazinas/química
2.
Am J Otolaryngol ; 45(4): 104342, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38703609

RESUMO

OBJECTIVE: To develop a multi-instance learning (MIL) based artificial intelligence (AI)-assisted diagnosis models by using laryngoscopic images to differentiate benign and malignant vocal fold leukoplakia (VFL). METHODS: The AI system was developed, trained and validated on 5362 images of 551 patients from three hospitals. Automated regions of interest (ROI) segmentation algorithm was utilized to construct image-level features. MIL was used to fusion image level results to patient level features, then the extracted features were modeled by seven machine learning algorithms. Finally, we evaluated the image level and patient level results. Additionally, 50 videos of VFL were prospectively gathered to assess the system's real-time diagnostic capabilities. A human-machine comparison database was also constructed to compare the diagnostic performance of otolaryngologists with and without AI assistance. RESULTS: In internal and external validation sets, the maximum area under the curve (AUC) for image level segmentation models was 0.775 (95 % CI 0.740-0.811) and 0.720 (95 % CI 0.684-0.756), respectively. Utilizing a MIL-based fusion strategy, the AUC at the patient level increased to 0.869 (95 % CI 0.798-0.940) and 0.851 (95 % CI 0.756-0.945). For real-time video diagnosis, the maximum AUC at the patient level reached 0.850 (95 % CI, 0.743-0.957). With AI assistance, the AUC improved from 0.720 (95 % CI 0.682-0.755) to 0.808 (95 % CI 0.775-0.839) for senior otolaryngologists and from 0.647 (95 % CI 0.608-0.686) to 0.807 (95 % CI 0.773-0.837) for junior otolaryngologists. CONCLUSIONS: The MIL based AI-assisted diagnosis system can significantly improve the diagnostic performance of otolaryngologists for VFL and help to make proper clinical decisions.


Assuntos
Inteligência Artificial , Laringoscopia , Leucoplasia , Prega Vocal , Humanos , Prega Vocal/diagnóstico por imagem , Prega Vocal/patologia , Laringoscopia/métodos , Masculino , Leucoplasia/diagnóstico , Leucoplasia/patologia , Feminino , Pessoa de Meia-Idade , Idoso , Diagnóstico por Computador/métodos , Aprendizado de Máquina , Diagnóstico Diferencial , Adulto , Algoritmos , Neoplasias Laríngeas/diagnóstico , Neoplasias Laríngeas/patologia , Neoplasias Laríngeas/diagnóstico por imagem
3.
Sensors (Basel) ; 24(6)2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38544079

RESUMO

Crowd counting is an important task that serves as a preprocessing step in many applications. Despite obvious improvement reported by various convolutional-neural-network-based approaches, they only focus on the role of deep feature maps while neglecting the importance of shallow features for crowd counting. In order to surmount this issue, a dilated convolutional-neural-network-based cross-level contextual information extraction network is proposed in this work, which is abbreviated as CL-DCNN. Specifically, a dilated contextual module (DCM) is constructed by importing cross-level connection between different feature maps. It can effectively integrate contextual information while conserving the local details of crowd scenes. Extensive experiments show that the proposed approach outperforms state-of-the-art approaches using five public datasets, i.e., ShanghaiTech part A, ShanghaiTech part B, Mall, UCF_CC_50 and UCF-QNRF, achieving MAE 52.6, 8.1, 1.55, 181.8, and 96.4, respectively.

4.
Anal Chem ; 95(11): 5159-5167, 2023 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-36896726

RESUMO

Oxidative stress and related oxidative damage have a causal relation with the pathogenesis of hypertension. Therefore, it is crucial to determine the mechanism of oxidative stress in hypertension by applying mechanical forces on cells to simulate hypertension while monitoring the release of reactive oxygen species (ROS) from cells under an oxidative stress environment. However, cellular level research has rarely been explored because monitoring the ROS released by cells is still challenging owing to the interference of O2. In this study, an Fe single-atom-site catalyst anchored on N-doped carbon-based materials (Fe SASC/N-C) was synthesized, which exhibits excellent electrocatalytic activity for the reduction of hydrogen peroxide (H2O2) at a peak potential of +0.1 V and can effectively avoid the interference of O2. Furthermore, we constructed a flexible and stretchable electrochemical sensor based on the Fe SASC/N-C catalyst to study the release of cellular H2O2 under simulated hypoxic and hypertension conditions. Density functional theory calculations show that the highest transition state energy barrier from the oxygen reduction reaction (ORR), i.e., O2 to H2O, is 0.38 eV. In comparison, the H2O2 reduction reaction (HPRR) can be completed only by overcoming a lower energy barrier of 0.24 eV, endowing the HPRR to be more favorable on Fe SASC/N-C compared with the ORR. This study provided a reliable electrochemical platform for real-time investigation of H2O2-related underlying mechanisms of the hypertension process.


Assuntos
Peróxido de Hidrogênio , Hipertensão , Humanos , Espécies Reativas de Oxigênio , Estresse Oxidativo , Deutério , Hipóxia , Oxigênio
5.
Anal Chem ; 95(38): 14365-14374, 2023 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-37712586

RESUMO

Though many elegant laccase mimics have emerged, these mimics generally have no substrate selectivity as well as low activity, making it difficult to fulfill the demand for monitoring in physiological conditions. Herein, inspired by the Cu-N ligand structure in the active site of natural laccase, we revealed that a carbon nanomaterial with atomically dispersed Cu and Zn atoms (CuZn-N/C) and a well-defined ligand structure could function as an effective laccase mimic for selectively catalyzing epinephrine (EP) oxidation. Catalytic activity of the CuZn-N/C nanozyme was superior to those of Cu-N/C and Zn-N/C and featured a Km value nearly 3-fold lower than that of natural laccase, which indicated that CuZn-N/C has a better affinity for EP. Density functional theory (DFT) revealed the mechanism of the superior catalytic ability of dual-metal CuZn-N/C as follows: (1) the exact distance of the two metal atoms in the CuZn-N/C catalyst makes it suitable for adsorption of the EP molecule, and the CuZn-N/C catalyst can offer the second hydrogen bond that stabilizes the adsorption; (2) molecular orbitals and density of states indicate that the strong interaction between the EP molecule and CuZn-N/C is important for EP catalytic oxidization. Furthermore, a sensitive and selective online optical detection platform (OODP) is constructed for determining EP with a low limit of detection (LOD) of 0.235 µM and a linear range of 0.2-20 µM. The system allows real-time measurement of EP release in the rat brain in vivo following ischemia with dexmedetomidine administration. This work not only provides an idea of designing efficient laccase mimics but also builds a promising chemical platform for better understanding EP-related drug action for ischemic cerebrovascular illnesses and opens up possibilities to explore brain function.


Assuntos
Encéfalo , Lacase , Animais , Ratos , Ligantes , Especificidade por Substrato , Epinefrina
6.
Small ; 19(10): e2206626, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36642809

RESUMO

Direct electrocatalytic reduction of N2 to NH3 under mild conditions is attracting considerable interests but still remains enormous challenges in terms of respect of intrinsic catalytic activity and limited electrocatalytic efficiency. Herein, a photo-enhanced strategy is developed to improve the NRR activity on Cu single atoms catalysts. The atomically dispersed Cu single atoms supported TiO2 nanosheets (Cu SAs/TiO2 ) achieve a Faradaic Efficiency (12.88%) and NH3 yield rate (6.26 µg h-1 mgcat -1 ) at -0.05 V versus RHE under the light irradiation field, in which NH3 yield rate is fivefold higher than that under pure electrocatalytic nitrogen reduction reaction (NRR) process and is remarkably superior in comparison to most of the similar type electrocatalysts. The existence of external light field improves electron transfer ability between CuO and TiO, and thus optimizes the accumulation of surface charges on Cu sites, endowing more electrons involved in nitrogen fixation. This work reveals an atomic-scale mechanistic understanding of field effect-enhanced electrochemical performance of catalysts and it provides predictive guidelines for the rational design of photo-enhanced electrochemical N2 reduction catalysts.

7.
Chemistry ; 29(14): e202202744, 2023 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-36446736

RESUMO

Among the factors that lead to the reduction of the efficiency of perovskite solar cells (PSCs) the difficulty involved in realizing a high-quality film and the efficient charge transfer that takes place at the interface between electron-transport layer (ETL) and perovskite is worth mentioning. Here, a strategy for planar-type devices by natural bio-functional interfaces that uses a buried electron-transport layer made of cobalamin complexed tin oxide (SnO2 @B12 ) is demonstrated. Having systematically investigated the effects of SnO2 @B12 interfacial layer in perovskite solar cells, it can be concluded that cobalamin can chemically link the SnO2 layer and the perovskite layer, resulting in improved perovskite film quality and interfacial defect passivation. Utilizing SnO2 @B12 improves the efficiency of planar-type PSCs by 20.60 %. Furthermore, after 250 h of exposure to an ambient atmosphere, unsealed PSCs containing SnO2 @B12 degrade by 10 %. This research provides a viable method for developing bio-functional molecules that will increase the effectiveness and durability of planar-perovskite solar cells.

8.
Biomed Chromatogr ; 37(1): e5523, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36336973

RESUMO

Occupational chronic cadmium poisoning (OCCP) can cause irreversible organ damage. Currently, no effective treatment is available for OCCP, and effective and sensitive biomarkers for treatment evaluation are still lacking. In this study, metabolomics techniques were used to analyze changes in endogenous metabolites in the urine of patients with OCCP after 15 years of treatment. Thirty urine samples from female patients with OCCP and healthy female controls (n = 15 per group) were assessed using gas chromatography-time-of-flight mass spectrometry and ultra-high-performance liquid chromatography-Q-Exactive mass spectrometry. The OCCP group had higher concentrations of blood urea nitrogen and urinary cadmium but near-normal urinary concentrations of ß2 -microglobulin and retinol-binding protein. Compared with the control group, the OCCP group had 66 significantly different metabolites with a variable importance in projection score >1 and p < 0.05. These differential metabolites were involved in various metabolic pathways, such as creatine metabolism, nicotinate and nicotinamide metabolism, the pentose phosphate pathway, d-glutamine and d-glutamate metabolism, and amino acid metabolism. Compared with the control group, the OCCP group had significantly higher urinary concentrations of creatine, glutamic acid, quinolinic acid and nicotinic acid. In a receiver operator characteristic analysis, the area under the curve of creatine was higher than those for glutamic acid, quinolinic acid and nicotinic acid, indicating that urinary concentrations of creatine could be used as a sensitive biomarker for the diagnosis and prognosis of OCCP and for monitoring its treatment.


Assuntos
Intoxicação por Cádmio , Niacina , Humanos , Feminino , Creatina , Ácido Quinolínico , Ácido Glutâmico , Metabolômica/métodos , Biomarcadores
9.
Sensors (Basel) ; 23(11)2023 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-37299841

RESUMO

Aiming at the problems of low detection efficiency and poor detection accuracy caused by texture feature interference and dramatic changes in the scale of defect on steel surfaces, an improved YOLOv5s model is proposed. In this study, we propose a novel re-parameterized large kernel C3 module, which enables the model to obtain a larger effective receptive field and improve the ability of feature extraction under complex texture interference. Moreover, we construct a feature fusion structure with a multi-path spatial pyramid pooling module to adapt to the scale variation of steel surface defects. Finally, we propose a training strategy that applies different kernel sizes for feature maps of different scales so that the receptive field of the model can adapt to the scale changes of the feature maps to the greatest extent. The experiment on the NEU-DET dataset shows that our model improved the detection accuracy of crazing and rolled in-scale, which contain a large number of weak texture features and are densely distributed by 14.4% and 11.1%, respectively. Additionally, the detection accuracy of inclusion and scratched defects with prominent scale changes and significant shape features was improved by 10.5% and 6.6%, respectively. Meanwhile, the mean average precision value reaches 76.8%, compared with the YOLOv5s and YOLOv8s, which increased by 8.6% and 3.7%, respectively.

10.
Cancer Cell Int ; 22(1): 190, 2022 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-35578228

RESUMO

Extracellular vesicles secreted by tumor microenvironment (TME) cells are vital players in tumor progression through transferring nucleic acids and proteins. Macrophages are the main immune cells in TME and tumor associated macrophages (TAM) express M2 phenotype, which induce tumor proliferation, angiogenesis, invasion, metastasis and immune elimination, resulting in the subsequent evolution of malignancies. There are a high number of studies confirmed that tumor cells and TAM interact with each other through extracellular vesicles in various cancers, like pancreatic ductal adenocarcinoma, gastric cancer, breast cancer, ovarian cancer, colon cancer, glioblastoma, hepatocellular cancer, and lung cancer. Herein, this review summarizes the current knowledge on mechanisms of communications between tumor cells and TAM via extracellular vesicles, mainly about microRNAs, and targeting these events might represent a novel approach in the clinical implications of this knowledge into successful anti-cancer strategies.

11.
J Surg Oncol ; 126(4): 804-813, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35765926

RESUMO

The treatment of periacetabular malignancy frequently challenges surgeons. To simplify the surgical procedure, we performed a novel reconstruction strategy preserving the femoral head for patients with periacetabular malignancies. We retrospectively reviewed 14 patients who underwent total en bloc resection of a periacetabular tumor and reconstruction of the hip joint with an individualized hemipelvic endoprosthesis and remaining femoral head from July 2015 to January 2019 at our center. Regions of pelvic resection: region II-4 (28.6%), region I + II-5 (35.7%), region II + III-2 (14.3%) and region I + II + III-3 (21.4%). The oncological outcomes were that 13 patients survived without disease and one patient survived with lung metastasis. None of the patients experienced local recurrence (range: 20-62 months; mean: 32 months). The incidence of postoperative complications was 35.7%, including delayed wound healing and deep venous thrombosis. No prosthesis-related complications occurred until the last follow-up in this study (range: 20-62 months; mean: 32 months). The mean Musculoskeletal Tumor Society functional outcome score was 23.2. The mean Toronto Extremity Salvage Score of the patients was 75.7 points, with a mean limb discrepancy of 1.51 cm (range: 0.5-3.2 cm). Reconstruction with preservation of the femoral head showed acceptable early functional and oncological outcomes, and it had an acceptable complication rate.


Assuntos
Neoplasias Ósseas , Procedimentos de Cirurgia Plástica , Acetábulo/patologia , Acetábulo/cirurgia , Neoplasias Ósseas/patologia , Neoplasias Ósseas/cirurgia , Cabeça do Fêmur/patologia , Cabeça do Fêmur/cirurgia , Humanos , Próteses e Implantes , Procedimentos de Cirurgia Plástica/métodos , Estudos Retrospectivos , Resultado do Tratamento
12.
Nanotechnology ; 33(50)2022 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-36067725

RESUMO

Remote control of cells and the regulation of cell events at the molecular level are of great interest to the biomedical field. In addition to mechanical forces and genes, chemical compounds and light play pivotal roles in regulating cell fate, which have boosted the fast growth of biology. Herein, we synthesized light-regulated, atomically dispersed Fe-N4immobilized on a carbon substrate nanozyme (Fe-N/C single atom catalysts), whose peroxidase- and catalase-like properties can be enhanced by 120% and 135%, respectively, under 808-nm laser irradiation through the photothermal effect of Fe-N/C. Interestingly, a switch to love/switch to kill interaction between Fe-N/C dose and near-infrared (NIR) light co-regulating the Fe-N/C nanozyme to modulate cell fate was discovered. Based on this, we found that under NIR light irradiation, when the dose of Fe-N/C is low, it can scavenge more reactive oxygen species (ROS) and achieve cell protection; when the dose of Fe-N/C is too high, it tended to lead to cell apoptosis. This work not only provides an effective strategy for the regulation of nanozyme activity but also realizes the dual-functional application of nanozyme materials for the treatment of some specific diseases.


Assuntos
Ferro , Carbono/química , Catalase , Ferro/química , Ferro/farmacologia , Espécies Reativas de Oxigênio
13.
Environ Res ; 212(Pt B): 113355, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35472467

RESUMO

In this study, ethanol-type fermentation pretreatment and adding two types of biochar prepared at 600 °C and 1000 °C (referred to as SS600 and SS1000) were combined to alleviate acid accumulation via strengthening direct interspecies electron transfer (DIET) during anaerobic digestion of food waste. Results demonstrated that ethanol production was about 11 g/L after the ethanol-type fermentation at pH of 4-5 for 4 days, accounting for 8.9% of the influent COD of the subsequent methanogenesis. After the ethanol-type fermentation pretreatment, average methane productions of digesters with SS600 and SS1000 addition increased by 86.3% and 64.9% to 618.1 ± 30.1 and 527.3 ± 25.4 mL/g VS under solid retention time (SRT) of 25 d respectively, and the conductivity of sludge increased by 95.3% and 65.3% compared to digester without biochar addition. Furthermore, adding biochar also could accelerate the recovery of acidification digester. The relative abundance of Methanothrix performing DIET were enriched with SS600. These results suggested that coupling ethanol-type fermentation with biochar addition could strengthen DIET to resist the shocks of high organic loading rate.


Assuntos
Reatores Biológicos , Eliminação de Resíduos , Anaerobiose , Carvão Vegetal , Etanol , Fermentação , Alimentos , Metano , Esgotos
14.
BMC Pulm Med ; 22(1): 333, 2022 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-36056339

RESUMO

BACKGROUND: Human tumors are highly heterogeneous at the cellular, molecular, genetic and functional levels. Tumor heterogeneity has tremendous impact on cancer progression and treatment responses. However, the mechanisms for tumor heterogeneity have been poorly understood due to the lack of experimental models. METHODS: This study provides a novel exploration and analysis of the impacts of cellular and molecular heterogeneity of human lung epithelial cells on their malignant transformation following chronic exposure to cigarette smoke extracts. RESULTS: The ability of cigarette smoke extract (CSE) to cause malignant transformation of the human bronchial epithelial cells (16HBE) is dependent on the sizes of the cells. Epithelial-mesenchymal transition (EMT) plays an important role in this process. Mechanistically, CSE-induced malignant transformation of 16HBE cells was closely linked to the reduced relative telomere length of the larger 16HBE cells, thereby up-regulation of the expression of stemness genes. CONCLUSIONS: These findings provide novel insights for understanding the impact of cellular heterogeneity in lung cancer development. The in vitro transformation model described in this study could be extrapolated to studying the pathogenesis of other malignancies, as well as for mechanistic studies that are not feasible in vivo.


Assuntos
Fumar Cigarros , Neoplasias Pulmonares , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Fumar Cigarros/efeitos adversos , Células Epiteliais/metabolismo , Transição Epitelial-Mesenquimal , Humanos , Neoplasias Pulmonares/genética , Nicotiana/efeitos adversos
15.
Molecules ; 27(16)2022 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-36014414

RESUMO

Hydroxychloroquine (HCQ) is an autophagy inhibitor that has been used for the treatment of many diseases, such as malaria, rheumatoid arthritis, systemic lupus erythematosus, and cancer. Despite the therapeutic advances in these diseases, the underlying mechanisms have not been well determined and hinder the rational use of this drug in the future. Here, we explored the possible mechanisms and identified the potential binding targets of HCQ by performing quantitative proteomics and thermal proteome profiling on MIA PaCa-2 cells. This study revealed that HCQ may exert its functions by targeting some autophagy-related proteins such as ribosyldihydronicotinamide dehydrogenase (NQO2) and transport protein Sec23A (SEC23A), or regulating the expression of galectin-8 (LGALS8), mitogen-activated protein kinase 8 (MAPK8), and so on. Furthermore, HCQ may prevent the progression of pancreatic cancer by regulating the expression of nesprin-2 (SYNE2), protein-S-isoprenylcysteine O-methyltransferase (ICMT), and cotranscriptional regulator FAM172A (FAM172A). Together, these findings not only identified potential binding targets for HCQ but also revealed the non-canonical mechanisms of HCQ that may contribute to pancreatic cancer treatment.


Assuntos
Antirreumáticos , Artrite Reumatoide , Lúpus Eritematoso Sistêmico , Neoplasias Pancreáticas , Antirreumáticos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Galectinas , Humanos , Hidroxicloroquina/farmacologia , Hidroxicloroquina/uso terapêutico , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Neoplasias Pancreáticas/tratamento farmacológico , Proteínas/uso terapêutico , Proteômica
16.
Fa Yi Xue Za Zhi ; 38(5): 618-624, 2022 Oct 25.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-36727179

RESUMO

Physical exercise can reduce the overall risk of cardiovascular disease, prolong lifespan and improve the quality of life, but some studies have shown that there is a certain correlation between vigorous physical exercise and sudden cardiac death. A number of retrospective or prospective studies on sports-related sudden cardiac death (SrSCD) have been conducted at home and abroad. This article reviews the related studies on the definition, epidemiological characteristics, common causes of SrSCD and effects of excercise on cardiovascular function, pre-exercise screening and evaluation of SrSCD, in order to understand the latest research progress on SrSCD and provide clues and references for SrSCD research.


Assuntos
Morte Súbita Cardíaca , Qualidade de Vida , Humanos , Estudos Retrospectivos , Estudos Prospectivos , Incidência , Morte Súbita Cardíaca/etiologia , Morte Súbita Cardíaca/prevenção & controle
17.
Soft Matter ; 17(3): 637-644, 2021 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-33210672

RESUMO

It is difficult for the same molecule to form vesicular assemblies in water and alipatic hydrocarbon (oil), respectively. Here, we report that chiral oligo(methylene-p-phenyleneethynylene)s bearing hydrophobic or hydrophilic side chains can take extended conformations to self-assemble into vesicle-like particles in a hydrophobic or hydrophilic solvent system. The self-assembly processes are highly independent of molecular design and chemical environments. Based on the analyses of TEM, UV, CD and PXRD data, it is plausible to expect that the vesicular membranes could be stabilized together by π-π stacking interactions between foldamer backbones and collective van der Waals interactions between side chains.

18.
Soft Matter ; 17(44): 10073-10079, 2021 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-34714902

RESUMO

It is difficult for the same molecule to self-assemble into stable vesicular particles in water and aliphatic hydrocarbon (oil), respectively. Here we demonstrated that chiral oligo(methylene-p-phenyleneethynylene)s with alternating hydrophilic and hydrophobic side chains were able to self-assemble into vesicular particles independent of solvent polarity. These particles were well dispersed in aliphatic hydrocarbon, alcohol or water for at least one month at room temperature, and readily transferred from organic to aqueous phases via dialysis. They displayed a noticeable response to the acidity of the aqueous phase, and could be used as simple cargos for loading hydrophilic or hydrophobic molecules in aqueous cores, which were different from loading in polymersomes. The vesicular particles loaded with hydrophobic paclitaxel exhibited comparable anti-HeLa cell activity to free paclitaxel in vitro.


Assuntos
Paclitaxel , Água , Interações Hidrofóbicas e Hidrofílicas , Solventes
19.
Environ Sci Technol ; 55(11): 7615-7623, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34014661

RESUMO

Feammox, that is, Fe(III) reduction coupled to anaerobic ammonium oxidation, has been reported to play an important role in the nitrogen cycle in natural environments. However, the application of Feammox in wastewater treatment is limited because continuous Fe(III) supplementation is required for achieving continuous nitrogen removal, which is not feasible in practice. In this study, air was aerated intermittently into the Feammox system containing iron and high-content ammonium for oxidizing Fe(II) generated from Feammox to Fe(III), then, the produced Fe(III) participated in the next round of Feammox, leading to continuous nitrogen removal through the Fe(II)/Fe(III) cycle. The results showed that after each 10 min of aeration (150 mL/min), every 6-7 days, dissolved oxygen (DO) increased from 0 to about 0.4 mg/L, accompanied by a decrease in Fe(II) and an increase in Fe(III). One day after the aeration, DO was undetectable, and then, Fe(II) content increased and Fe(III) content decreased. On day 90, NH4+-N content in the aerated reactor was only 10.2 mg/L, while it remained at around 288.3 mg/L in the aeration-free group. X-ray diffraction showed that the generated Fe(III) through air aeration was Fe(OH)3. Microbial analysis showed that anammox and nitrification/denitrification could be excluded in the system. This NH4+ removal process, driven by the Fe(II)/Fe(III) cycle with O2 as the terminal electron acceptor, might be used as an in situ remediation method for treating high-content NH4+.


Assuntos
Compostos de Amônio , Anaerobiose , Reatores Biológicos , Desnitrificação , Compostos Férricos , Compostos Ferrosos , Nitrogênio , Oxirredução
20.
Cardiovasc Drugs Ther ; 35(3): 587-598, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-32462265

RESUMO

INTRODUCTION: Atrial fibrillation (AF) is the most common type of arrhythmia. Atrial remodeling is a major factor to the AF substrate. The purpose of the study is to explore whether aliskiren (ALS) has a cardioprotective effect and its potential molecular mechanisms on atrial remodeling. METHODS: In acute experiments, dogs were randomly assigned to Sham, Paced and Paced+aliskiren (10 mg kg-1) (Paced+ALS) groups, with 7 dogs in each group. Rapid atrial pacing (RAP) was maintained at 600 bpm for 2 h for paced and Paced+ALS groups and atrial effective refractory periods (AERPs), inducibility of AF (AFi) and average duration time (ADT) were measured. In chronic experiments, there were 5 groups: Sham, Sham+ALS, Paced, Paced+ALS and Paced+ALS+PI3K antagonist wortmannin (WM) (70 µg kg-1 day-1). RAP at 500 beats/min was maintained for 2 weeks. Inflammation and oxidative stress indicators were measured by ELISA assay, echocardiogram and pathology were used to assess atrial structural remodeling, phosphatidylinositol 3-hydroxy kinase/protein kinase B (PI3K/Akt) signaling pathways were studied by RT-PCR and western blotting to evaluate whether the cardioprotective effect of ALS works through PI3K/Akt signaling pathway. RESULTS: The electrophysiological changes were observed after 2-h pacing. The AERP shortened with increased AFi and ADT, which was attenuated by ALS (P < 0.05). After pacing for 2 weeks, oxidative stress and inflammation markers in the Paced group were significantly higher than those in the Sham group (P < 0.01) and were reduced by ALS treatment (P < 0.01). The reduced level of antioxidant enzymes caused by RAP was also found to be elevated in ALS-treated group (P < 0.01). The results of pathology and echocardiography showed that RAP can cause atrial enlargement, fibrosis (P < 0.01), and were attenuated in ALS treatment group. The PI3K/Akt signaling pathway were downregulated induced by RAP. ALS could upregulate the PI3K/Akt pathway expression (P < 0.05). Furthermore, the cardioprotective effects in structural remodeling of ALS were suppressed by WM. CONCLUSIONS: ALS may offer cardioprotection in RAP-induced atrial remodeling, which may partly be ascribed to its anti-inflammatory and anti-oxidative stress action and the regulation of PI3K/Akt signaling pathway.


Assuntos
Amidas/farmacologia , Remodelamento Atrial/efeitos dos fármacos , Fumaratos/farmacologia , Animais , Cães , Ecocardiografia , Feminino , Mediadores da Inflamação/metabolismo , Masculino , Estresse Oxidativo/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , Distribuição Aleatória , Transdução de Sinais/efeitos dos fármacos , Wortmanina/farmacologia
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