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1.
Protein Expr Purif ; 224: 106577, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39153562

RESUMO

Developing more effective bioactive ingredients of natural origin is imperative for promoting wound healing. Sea cucumbers have long enjoyed a good reputation as both food delicacies and traditional medicines. In this study, we heterogeneously expressed a Apostichopus japonicus derived novel protein AjPSPLP-3, which exhibits a theoretical molecular weight of 13.034 kDa, through fusion with maltose binding protein (MBP). AjPSPLP-3 contains a strict CXXCXC motif, nine extremely conserved cysteine residues and two highly conserved cysteine residues. The predicted structure of AjPSPLP-3 consists of random coil and nine ß-sheets, Cys30-Cys67, Cys38-Cys58, Cys53-Cys90, Cys56-Cys66, and Cys81-Cys102 participating in the formation of five pairs of disulfide bonds. In vitro experiments conducted on HaCaT cells proved that AjPSPLP-3 and MBP-fused AjPSPLP-3 significantly contribute to HaCaT cells proliferation and migration without exhibiting hemolytic activity on murine erythrocytes. Specifically, treatment with 10 µmol/L MBP-fused AjPSPLP-3 protein increased the viability of HaCaT cells by 12.28 % (p < 0.001), while treatment with 10 µmol/L AjPSPLP-3 protein increased viability of HaCaT cells by 6.01 % (p < 0.01). Furthermore, wound closure of MBP-fused AjPSPLP-3 and AjPSPLP-3 were 22.51 % (p < 0.01) and 7.32 % (p < 0.05) higher than that of the control groups in HaCaT cells following 24 h of incubation.


Assuntos
Movimento Celular , Proliferação de Células , Stichopus , Animais , Stichopus/genética , Stichopus/química , Proliferação de Células/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Humanos , Camundongos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/farmacologia , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes de Fusão/isolamento & purificação , Clonagem Molecular , Sequência de Aminoácidos , Linhagem Celular , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas Ligantes de Maltose/genética , Proteínas Ligantes de Maltose/química , Proteínas Ligantes de Maltose/metabolismo , Células HaCaT
2.
Int Microbiol ; 2024 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-39316254

RESUMO

Antimicrobial peptides (AMPs) are a family of short defense proteins that are naturally produced by all organisms and have great potential as effective substitutes for small-molecule antibiotics. The present study aims to excavate AMPs from sea cucumbers and achieve their heterologous expression in prokaryotic Escherichia coli. Using MytC as a probe, a cysteine-stabilized peptide SCAK33 with broad-spectrum antimicrobial activity was discovered from the proteome of Apostichopus japonicas. The SCAK33 showed inhibitory effects on both gram positive and gram negative bacteria with MICs of 3-28 µM, and without significant hemolysis activity in rat blood erythrocyte. Especially, it exhibited good antimicrobial activity against Bacillus megaterium, B. subtilis, and Vibrio parahaemolyticus with the MIC of 3, 7, and 7 µM, respectively. After observation by scanning electronic microscopy (SEM) and confocal laser scanning microscope (CLSM), it was found that the cell membrane of bacteria was severely damaged. Furthermore, the recombinant SCAK33 (reSCAK33) was heterologously expressed by fusion with SUMO tag in E. coli BL21(DE3), and the protein yield reached 70 mg/L. The research will supplement the existing quantity of sea cucumber AMPs and provide data support for rapid mining and biological preparation of sea cucumber AMPs.

3.
Microvasc Res ; 147: 104506, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36792028

RESUMO

Accumulating evidence suggests that interleukin (IL)-33 plays a critical role in regulating angiogenesis and cancer progression. In this study, we characterized the pathological importance of IL-33 deployed by tumor microvascular endothelial cells (ECs) in human esophageal squamous cell carcinoma (ESCC). The expression of IL-33 in microvascular ECs in 80 cases of ESCC was examined with immunohistochemistry (IHC) and double immunofluorescence. IHC results showed that strong IL-33-immunoreactivity (IR) in microvessels, which were confirmed to be ECs by double immunofluorescence staining with IL-33/CD31 antibodies. Moreover, high proliferative activity was shown in IL-33-positive ECs, and the IL-33 functional receptor ST2 was expressed in microvascular ECs. Clinicopathological analysis revealed that IL-33-positive microvessel density (MVD) was positively correlated with node involvement in patients with ESCC. A log rank test showed a highly significant inverse correlation between the densities of IL-33-positive MVDs and overall survival rate, and patients with higher IL-33-positive MVDs tended to have a lower survival rate (both p < 0.05). Therefore, we concluded that IL-33 deployed by microvascular ECs correlates with advanced pathological features and the long-term survival rate, which provides new insights into the regulatory mechanisms of tumor angiogenesis in the tumor microenvironment and might serve as a promising target in patients with ESCC.


Assuntos
Carcinoma de Células Escamosas , Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Humanos , Carcinoma de Células Escamosas do Esôfago/metabolismo , Carcinoma de Células Escamosas do Esôfago/patologia , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Células Endoteliais/metabolismo , Interleucina-33 , Prognóstico , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/metabolismo , Microambiente Tumoral
4.
Biogerontology ; 2023 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-37572203

RESUMO

Jingfang Granule (JFG), a traditional Chinese medicine, is frequently employed in clinical settings for the treatment of infectious diseases. Nevertheless, the anti-aging and anti-infection effects of JFG remain uncertain. In the present study, these effects were evaluated using the Caenorhabditis elegans (C. elegans) N2 as a model organism. The results demonstrated that JFG significantly increased the median lifespan of C. elegans by 31.2% at a dosage of 10 mg/mL, without any discernible adverse effects, such as alterations in the pharyngeal pumping rate or nematode motility. Moreover, JFG notably increased oviposition by 11.3%. Subsequent investigations revealed that JFG enhanced oxidative stress resistance in C. elegans by reducing reactive oxygen species levels and significantly improved survival rates in nematodes infected with Pseudomonas aeruginosa ATCC 9027. These findings suggest that JFG delays reproductive senescence in C. elegans and protects them from oxidative stress, thereby extending their lifespan. Additionally, JFG improves the survival of P. aeruginosa-infected nematodes. Consequently, JFG has potential as a candidate for the development of anti-aging and anti-infection functional medicines.

5.
Med Sci Monit ; 28: e933447, 2022 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-35027526

RESUMO

BACKGROUND H2A histone family member Z (H2AFZ) is a special subtype in the H2A histone family, which participates in the regulation of gene transcription. Nevertheless, little is known about the role of H2AFZ in the tumor microenvironment and genetic factors associated with lung cancer. MATERIAL AND METHODS The expression of H2AFZ in LUAD was analyzed via Tumor Immune Estimation Resource (TIMER), the Cancer Genome Atlas (TCGA), and Gene Expression Omnibus (GEO) databases at the mRNA level. To detect the protein expression level of H2AFZ, immunohistochemistry (IHC) was performed using LUAD tissues and non-tumor lung tissues. Kaplan-Meier survival analysis and Cox regression analysis were conducted to identify the effect of H2AFZ expression on overall survival (OS) based on TCGA-LUAD and the GEO dataset GSE68465 cohorts, and our LUAD patient cohort was used for validation. Identification of signaling pathways associated with the expression of H2AFZ was performed using Gene Set Enrichment Analysis (GSEA). The influences of expression of H2AFZ on tumor immune-infiltrating cell (TIICs) were assessed via TIMER and CIBERSORT. RESULTS The expression of H2AFZ was increased in LUAD tissues at both mRNA and protein levels. In addition, high expression of H2AFZ predicted poor OS and might be an independent prognostic predictor in LUAD patients. Moreover, H2AFZ affected the relative proportion of TIICs and was positively associated with Myeloid-derived suppressor cells (MDSC) infiltration level in LUAD. CONCLUSIONS H2AFZ was upregulated in LUAD and related to poor prognosis of LUAD patients; thus, it could be an underlying prognostic biomarker correlated with immune infiltration in LUAD.


Assuntos
Adenocarcinoma de Pulmão/diagnóstico , Adenocarcinoma de Pulmão/genética , Biomarcadores Tumorais/genética , Regulação Neoplásica da Expressão Gênica/genética , Histonas/genética , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Estudos de Coortes , Humanos , Prognóstico , Reprodutibilidade dos Testes , Microambiente Tumoral/genética
6.
Entropy (Basel) ; 24(7)2022 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-35885121

RESUMO

Reliable quantile estimates of annual peak flow discharges (APFDs) are needed for the design and operation of major hydraulic infrastructures and for more general flood risk management and planning. In the present study, linear higher order-moments (LH-moments) and nonparametric kernel functions were applied to APFDs at 18 stream gauge stations in Punjab, Pakistan. The main purpose of this study was to evaluate the impacts of different quantile estimation methods towards water resources management and engineering applications by means of comparing the state-of-the-art approaches and their quantile estimates calculated from LH-moments and nonparametric kernel functions. The LH-moments (η = 0, 1, 2) were calculated for the three best-fitted distributions, namely, generalized logistic (GLO), generalized extreme value (GEV), and generalized Pareto (GPA), and the performances of these distributions for each level of LH-moments (η = 0, 1, 2) were compared in terms of Anderson-Darling, Kolmogorov-Smirnov, and Cramér-Von Mises tests and LH-moment ratio diagrams. The findings indicated that GPA and GEV distributions were best fitted for most stations, followed by GLO distribution. The quantile estimates derived from LH-moments (η = 0, 1, 2) had a lower relative absolute error, particularly for higher return periods. However, the Gaussian kernel function provided a close estimate among nonparametric kernel functions for small return periods when compared to LH-moments (η = 0, 1, 2), thus highlighting the importance of using LH-moments (η = 0, 1, 2) and nonparametric kernel functions in water resources management and engineering projects.

7.
Small ; 16(50): e2005667, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33217165

RESUMO

Intelligent-responsive imaging-therapy strategy has shown great significance for biomedicine. However, it is still a challenge to construct spatiotemporally controlled imaging-therapy systems triggered by near infrared (NIR) light. In this work, NIR-light-activated ratiometric fluorescent hybrid micelles (RFHM) are prepared via the co-assembly of upconversion nanoparticles (UCNPs), doxorubicin (DOX), and UV-light-responsive amphiphilic block copolymer for the spatiotemporally controlled imaging and chemotherapy. Upon NIR light irradiation, UCNPs can convert NIR light to UV light. The emitted UV light induces the photoreaction of copolymer to further trigger ratiometric fluorescence imaging and degradation of hybrid micelles, resulting in rapid DOX release from hybrid micelles for antitumor therapy. The animal experiments reveal that NIR light can not only remotely regulate the ratiometric fluorescence imaging of RFHM in tumor tissue, but also trigger DOX release from RFHM to inhibit tumor growth. Therefore, this study provides a new strategy to achieve high spatial-temporal-controlled biological imaging and chemotherapy.


Assuntos
Micelas , Nanopartículas , Animais , Doxorrubicina/farmacologia , Sistemas de Liberação de Medicamentos , Polímeros
8.
Langmuir ; 35(52): 17009-17015, 2019 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-31804087

RESUMO

Deeply exploring the interaction of biomolecules with magnesium in solution is essential to understand the formation of complex bio-magnesium interfaces accompanied with corrosion products. Using the accelerated metadynamics simulations, we have investigated the interactions of amino acid analogues on clean and hydroxylated Mg(0001) surfaces by identifying their free energy barriers and adsorption sites. We find that there are two hydration layers stacked on the clean Mg(0001) surfaces and the hydroxylated Mg(0001) surfaces, which mainly determine the free energy barriers and adsorbed configurations. Further studies reveal that the water molecules in double hydration layers present two opposite orientations, depending on the charge distribution of the substrate. Specifically, oxygen atoms of water concentrate in the center of double hydration layers for a clean Mg surface but transfer to the outside surface once the Mg substrate is degraded. The reversed hydration layers greatly reduce the binding affinities of positively charged and electroneutral analogues. Overall, our simulation findings provide new insights into the interaction mechanism of biomolecules on a bio-magnesium device in the implantation initial stage, which is noteworthy for revealing the magnesium degradation mechanism in vivo.


Assuntos
Aminoácidos/química , Magnésio/química , Modelos Moleculares , Água/química , Adsorção , Conformação Molecular , Propriedades de Superfície , Termodinâmica
9.
Biomacromolecules ; 20(10): 4044-4052, 2019 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-31487160

RESUMO

Chemo-photodynamic combined therapy is promising in cancer treatment, although low tissue penetration of visible light for activating photosensitizers (e.g., chlorin e6, Ce6) limited its broad applications. Combination of upcoverting nanoparticles (UCNPs) with the photosensitizers endows us with the possibility to utilize highly tissue penetrable near-infrared light; nevertheless, the mismatch between absorption of common photosensitizers (λabs, mainly red) and emission of UCNPs (λem, mainly green) resulted in low energy utilization and unsatisfied therapeutic efficacy in the current UCNP-PDT (photodymanic therapy) platforms. To resolve this problem, herein, we construct polymer-UCNP hybrid micelles (PUHMs) for codelivery of doxorubicin (DOX) and Ce6, and systemically studied the effects of spectral match between λem of UCNPs and λabs of Ce6 on efficiency of synergistic chemo-photodynamic therapy. Compared with spectrally mismatched PUHMs, the spectrally matched PUHMs can significantly enhance the utilization efficiency of upconverted emission energy to activate the photosensitizers and generate more reactive oxygen species (ROS) for enhanced photodynamic therapy. Meanwhile, as the assembled structure of PUHMs can be destroyed by the oxidation of ROS upon 980 nm laser irradiation because of the hydrophobic-hydrophilic transformation of poly(propylene sulfide) (PPS) segment, the spectrally matched PUHMs triggered faster release of DOX, thus resulting in more effective chemotherapy. As a result, the spectrally matched PUHMs induced more prominent cytotoxicity and superior synergistic therapeutic effect for cancer cells in vitro. Our results demonstrated that such spectrally matched PUHMs provide us with an effective strategy for photodynamic-chemo synergistic therapy.


Assuntos
Antineoplásicos/química , Nanopartículas/química , Polímeros/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Doxorrubicina/química , Doxorrubicina/farmacologia , Portadores de Fármacos/química , Células HeLa , Humanos , Micelas , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/química , Espécies Reativas de Oxigênio/metabolismo
10.
Cell Physiol Biochem ; 48(3): 1139-1150, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30041193

RESUMO

BACKGROUND/AIMS: Non-coding RNAs (ncRNAs) play vital regulatory roles in many tumors. However, the functional roles of these transcripts responsible for their dysregulation in breast cancer (BC) are not thoroughly understood. METHODS: We examined the expression of microRNA miR-1471 in BC specimens. Online analysis tools predicted that lncRNA LOC101930370 might act as an endogenous 'sponge' by competing for miR-1471 binding targets. Luciferase assays were used to prove the interaction of LOC101930370, miR-1471 and SHH. Edu, wound-healing and transwell assays were used to verify the contribution of miR-1471 and LOC101930370 on MCF-7 cells proliferation and metastasis. Gain and loss of function studies were performed to evaluate the relevance of Hedgehog pathway with LOC101930370/miR-1471 regulating axis in MCF-7 cells. RESULTS: The expression of miR-1471 was markedly downregulated in BC. Inhibition of miR-1471 by LOC101930370 was proved by luciferase assay. Knockdown of LOC101930370 suppressed BC cells progression. MiR-1471 inhibitor resulted in a more aggressive metastasis of MCF-7 cells. Moreover, SHH and Gli-1 expression were significantly suppressed by LOC101930370 knockdown, and upregulated by miR-1471 inhibitor transfection. CONCLUSIONS: Collectively, our study reveals the interaction between LOC101930370 and miR-1471 for the first time. LOC101930370 positively regulates the expression of SHH by sponging miR-1471, which sheds new light on lncRNA-directed diagnostics and therapeutics in BC.


Assuntos
Neoplasias da Mama/genética , Regulação Neoplásica da Expressão Gênica , Proteínas Hedgehog/genética , Transdução de Sinais , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Proliferação de Células , Feminino , Técnicas de Silenciamento de Genes , Proteínas Hedgehog/metabolismo , Humanos , Células MCF-7 , Pessoa de Meia-Idade , Metástase Neoplásica/genética , Metástase Neoplásica/patologia , Regulação para Cima , Adulto Jovem
11.
Cancer Cell Int ; 18: 203, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30559604

RESUMO

BACKGROUND: Emerging evidence has suggested that interleukin (IL)-33 and its primary functional receptor ST2 are involved in the pathogenesis of tumorigenesis. METHODS: Using immunohistochemistry (IHC) and double immunofluorescence staining, we characterized the cellular and clinicopathological features of the IL-33/ST2 axis in different compartments in human esophageal squamous cell carcinoma (ESCC) surgical specimens. RESULTS: IHC data revealed an increased expression of IL-33-immunoreactivity (IR) and ST2-IR located in both ESCC cells and tumor stromal cells; which were associated with advanced clinicopathological features such as TNM stages and node involvement. However, the Kaplan-Meier analysis showed that densities of neither IL-33 positive nor ST2 positive cells in both the ESCC mass and stroma were associated with the overall survival rate in patients with ESCC. Double immunofluorescence staining for cellular feature analysis demonstrated that these IL-33 positive and ST2 positive cells in ESCCs were with a high proliferation rate, and IL-33-IR was frequently co-expressed with ST2-IR in both ESCC and stromal cells. CONCLUSION: Significant altered cellular features of the IL-33/ST2 axis in ESCCs were associated with advanced clinicopathological variables. The data suggest that the IL-33/ST2 axis might be involved in the progression of human ESCCs.

12.
Acta Radiol ; 58(1): 3-9, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26917786

RESUMO

BACKGROUND: Obstructive jaundice (OJ) is insensitive to radiation and chemotherapy, and a pathologic diagnosis is difficult to make clinically. Percutaneous transhepatic cholangiobiopsy (PTCB) is simple to perform and minimally invasive, and clinical practice has shown it to be an accurate and reliable new method for bile duct histopathologic diagnosis. PURPOSE: To investigate the value of PTCB for pathologic diagnosis of causes of OJ. MATERIAL AND METHODS: From April 2001 to December 2011, PTCB was performed in 826 consecutive patients. Data on pathologic diagnosis, true positive rate, and complications were analyzed retrospectively. Patients with negative pathologic findings were diagnosed using clinical, imaging, laboratory, and prognostic data. The feasibility and safety of PTCB for OJ were evaluated and true positive rates for biliary carcinoma and non-biliary carcinoma compared. RESULTS: PTCB was successful in all cases. Of 740 patients clinically diagnosed with malignant biliary stricture and 86 with benign biliary stricture, 727 received a positive pathologic diagnosis; in 99, the pathologic findings were considered false negative. The true positive rate for PTCB was 88.01% overall, differing significantly for biliary and non-biliary carcinoma (χ2 = 12.87, P < 0.05). Malignancy accounted for 89.59% of OJ cases; well, moderately, and poorly differentiated carcinoma represented 57.88%, 19.97%, and 22.15%. Biliary adenocarcinoma was the predominant malignant pathologic type (96.41%). Transient bilemia, bile leakage, and temporary hemobilia occurred in 47, 11, and 28 cases, respectively, with no serious complications. CONCLUSION: PTCB is safe, feasible, and simple, with a high true positive rate for definitive diagnosis of OJ causes. Well differentiated adenocarcinoma was the predominant pathologic type.


Assuntos
Neoplasias do Sistema Biliar/diagnóstico , Neoplasias do Sistema Biliar/epidemiologia , Biópsia/estatística & dados numéricos , Icterícia Obstrutiva/diagnóstico , Icterícia Obstrutiva/epidemiologia , Complicações Pós-Operatórias/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias do Sistema Biliar/patologia , Biópsia/métodos , Causalidade , China/epidemiologia , Comorbidade , Feminino , Humanos , Icterícia Obstrutiva/patologia , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/diagnóstico por imagem , Prevalência , Reprodutibilidade dos Testes , Fatores de Risco , Sensibilidade e Especificidade
13.
Chaos ; 27(8): 083124, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28863478

RESUMO

A three dimensional microbial continuous culture model with a restrained microbial growth rate is studied in this paper. Two types of dilution rates are considered to investigate the dynamic behaviors of the model. For the unforced system, fold bifurcation and Hopf bifurcation are detected, and numerical simulations reveal that the system undergoes degenerate Hopf bifurcation. When the system is periodically forced, bifurcation diagrams for periodic solutions of period-one and period-two are given by researching the Poincaré map, corresponding to different bifurcation cases in the unforced system. Stable and unstable quasiperiodic solutions are obtained by Neimark-Sacker bifurcation with different parameter values. Periodic solutions of various periods can occur or disappear and even change their stability, when the Poincaré map of the forced system undergoes Neimark-Sacker bifurcation, flip bifurcation, and fold bifurcation. Chaotic attractors generated by a cascade of period doublings and some phase portraits are given at last.

14.
Molecules ; 21(5)2016 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-27196888

RESUMO

A novel metal-free organobase-catalyzed regioselective benzoylation of diols and carbohydrates has been developed. Treatment of diol and carbohydrate substrates with 1.1 equiv. of 1-benzoylimidazole and 0.2 equiv. of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in MeCN under mild conditions resulted in highly regioselective benzoylation for the primary hydroxyl group. Importantly, compared to most commonly used protecting bulky groups for primary hydroxyl groups, the benzoyl protective group offers a new protection strategy.


Assuntos
Carboidratos/química , Di-Hidroxi-Di-Hidrobenzopirenos/química , Imidazóis/química , Carboidratos/síntese química , Catálise , Di-Hidroxi-Di-Hidrobenzopirenos/síntese química , Imidazóis/síntese química , Estrutura Molecular , Estereoisomerismo , Ureia/análogos & derivados , Ureia/química
15.
Bioorg Med Chem Lett ; 24(4): 1236-8, 2014 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-24447849

RESUMO

A series of novel 1,2,4-triazolo [3,4-a] phthalazine derivatives were synthesized in five steps from a common precursor, phthalic anhydride. Most of synthesized phthalazine derivatives showed inhibitory activity against Staphylococcus aureus. One of phthalazine derivatives 5l showed inhibitory activity against all tested bacterial and fungal strains.


Assuntos
Antibacterianos/farmacologia , Ftalazinas/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Triazóis/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Relação Dose-Resposta a Droga , Testes de Sensibilidade Microbiana , Estrutura Molecular , Ftalazinas/síntese química , Ftalazinas/química , Relação Estrutura-Atividade , Triazóis/síntese química , Triazóis/química
16.
Environ Pollut ; 356: 124395, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38901816

RESUMO

The escalating global occurrence of algal blooms poses a growing threat to ecosystem services. In this study, the spatiotemporal heterogeneity of water quality parameters was leveraged to partition Lake Dianchi into three clusters. Considering water quality parameters and both the delayed and instantaneous effects of meteorological factors, ensemble learning, and quasi-Monte Carlo methods were employed to predict daily algal cell density (AD) between January 2021 and January 2024. Consistently, superior predictive accuracy across all three clusters was exhibited by the Stacking-Elastic-Net regularization model. Furthermore, the minimum combination of drivers that achieved near-optimal accuracy for each cluster was identified, striking a balance between accuracy and cost. The ranking of the effect of drivers on AD varied by cluster, while the delayed effect of meteorological factors on AD generally outweighed their instantaneous effect for all clusters. Additionally, the heterogeneous or homogeneous thresholds and responses between drivers and AD were explored. These findings could serve as a scientific and cost-effective basis for government agencies to develop regional sustainable strategies for managing water quality.


Assuntos
Monitoramento Ambiental , Eutrofização , Lagos , Aprendizado de Máquina , Lagos/química , Monitoramento Ambiental/métodos , Qualidade da Água , Ecossistema
17.
Sci Total Environ ; 926: 171910, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38522549

RESUMO

Quantifying drivers contributing to air quality improvements is crucial for pollution prevention and optimizing local policies. Despite advances in machine learning for air quality analysis, their limited interpretability hinders attribution on global and local scales, vital for informed city management. Our study introduces an innovative framework quantifying socioeconomic and natural impacts on mitigation of particulate matter pollution in 31 Chinese major cities from 2014 to 2021. Two indices, formulated based on the additivity of Shapley additive explanations, are proposed to measure driver contributions globally and locally. Our analysis explores the self-contained and interactive effects of these drivers on particulate levels, pinpointing critical threshold values where these drivers trigger shifts in particulate matter levels. It is revealed that SO2, NOx, and dust emission reductions collectively account for 51.58 % and 51.96 % of PM2.5 and PM10 decreases at the global level. Moreover, our findings unveil a significant heterogeneity in driver contributions to pollutant mitigation across distinct cities, which can be instrumental in crafting location-specific policy recommendations.

18.
Macromol Biosci ; 24(2): e2300333, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37750477

RESUMO

In recent years, the development of new type wound dressings has gradually attracted more attention. Bacterial cellulose (BC) is a natural polymer material with various unique properties, such as ultrafine 3D nanonetwork structure, high water retention capacity, and biocompatibility. These properties allow BC to be used independently or in combination with different components (such as biopolymers and nanoparticles) to achieve diverse effects. This means that BC has great potential as a wound dressing. However, systematic summaries for the production and commercial application of BC-based wound dressings are still lacking. Therefore, this review provides a detailed introduction to the production fermentation process of BC, including various production strains and their biosynthetic mechanisms. Subsequently, with regard to the functional deficiencies of bacterial cellulose as a wound dressing, recent research progress in this area is enumerated. Finally, prospects are discussed for the low-cost production and high-value-added product development of BC-based wound dressings.


Assuntos
Bactérias , Celulose , Celulose/química , Bandagens , Biopolímeros/uso terapêutico , Biopolímeros/química , Polímeros
19.
Bioorg Med Chem Lett ; 23(14): 4154-6, 2013 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-23735742

RESUMO

Two series of novel AHL analogues were designed, synthesized and evaluated for antibacterial activity under cell membrane conditions in vitro. Analogues 4a-c and 4g-m presented potent activity against Gram-positive bacteria. Especially the analogue 4l exerted the most potent inhibition against Bacillus subtilis with MIC50 value of 1.443µg/ml. To our surprise, analogues 6a-c and 6g showed weak inhibition against Gram-negative bacteria with MIC50 values ranging from 17.589 to 67.840µg/ml. This was the first report about synthesis and antibacterial evaluation in vitro of AHL analogues containing dithioester linkage.


Assuntos
4-Butirolactona/análogos & derivados , Antibacterianos/síntese química , Desenho de Fármacos , 4-Butirolactona/síntese química , 4-Butirolactona/química , 4-Butirolactona/farmacologia , Antibacterianos/química , Antibacterianos/farmacologia , Carbamatos/síntese química , Carbamatos/química , Carbamatos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Percepção de Quorum/efeitos dos fármacos
20.
ACS Appl Mater Interfaces ; 15(30): 35884-35894, 2023 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-37487181

RESUMO

The effect of photodynamic therapy (PDT) is severely limited by tumor hypoxia and the short half-life of reactive oxygen species (ROS). Herein, we constructed a near-infrared (NIR) light-regulated PDT nanoplatform (TPP-UCNPs@MOF-Pt) consisting of an upconversion nanoparticle (UCNP) core and porphyrin-based metal-organic framework (MOF) shell with platinum nanoparticles (PtNPs) and a mitochondria-targeting triphenylphosphine (TPP) group on the surface. TPP-UCNPs@MOF-Pt could effectively relieve the tumor hypoxia by converting intracellular H2O2 to oxygen (O2) and elevated the ROS level to enhance PDT efficacy under NIR light irradiation. In addition, the mitochondria-targeting TPP-UCNPs@MOF-Pt was localized on the mitochondria, leading to severe depolarization of the mitochondrial membrane and activation of the apoptotic pathway, further amplifying the therapeutic efficacy. In vitro and in vivo experiments demonstrated that the greatly enhanced photodynamic therapeutic efficacy of TPP-UCNPs@MOF-Pt was achieved by combining relief of tumor hypoxia with mitochondrial targeting and NIR activation. This study provides a promising strategy for construction of an MOF-based multifunctional nanoplatform to address the current limitations of PDT treatment for hypoxic tumors.


Assuntos
Nanopartículas Metálicas , Estruturas Metalorgânicas , Nanopartículas , Neoplasias , Fotoquimioterapia , Humanos , Estruturas Metalorgânicas/farmacologia , Estruturas Metalorgânicas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Peróxido de Hidrogênio/metabolismo , Platina , Nanopartículas/uso terapêutico , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Oxigênio/metabolismo , Mitocôndrias/metabolismo , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Fármacos Fotossensibilizantes/metabolismo , Linhagem Celular Tumoral
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