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1.
Nano Lett ; 21(20): 8545-8553, 2021 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-34623162

RESUMO

The formation of membrane nanopores is one of the crucial activities of cells and has attracted considerable attention. However, the understanding of their types and mechanisms is still limited. Herein, we report a novel nanopore formation phenomenon achieved through the insertion of polymeric nanotoroids into the cellular membrane. As revealed by theoretical simulations, the nanotoroid can embed in the membrane, leaving a nanopore on the cell. The through-the-cavity wrapping of lipids is critical for the retention of the nanotoroid in the membrane, which is attributed to both a relatively large inner cavity of the nanotoroid and a moderate attraction between the nanotoroid and membrane lipids. Under the guidance of the simulation predictions, experiments using polypeptide toroids as pore-forming agents were performed, confirming the unique biophysical phenomenon. This work demonstrates a distinctive pore-forming pathway, deepens the understanding of the membrane nanopore phenomenon, and assists in the design of advanced pore-forming materials.


Assuntos
Nanoporos , Peptídeos , Polímeros
2.
Environ Monit Assess ; 194(3): 213, 2022 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-35199201

RESUMO

Extensive nutrient loss is one of the most challenging issues faced by agricultural production regions worldwide. However, diffuse pollution in the subtropical mountainous watersheds is rarely simulated. A watershed model with regional parameter values is essential for watershed management. In this study, SWAT, one of the most popular models was applied to simulate daily discharge (years of 2008-2014), NO3-N flux (2012-2014), and tea yield (2012-2014) in the Ping-Lin watershed (PLW) of Taiwan, as well as to test the effectiveness of a modified fertilization strategy. The results demonstrated that SWAT was capable of simulating daily discharge variation, daily riverine NO3-N flux, and tea yield in the PLW. NO3-N yield of the tea farm (47 kg/ha/yr) was 9 times higher than that of the forest (5.1 kg/ha/yr). A significant proportion (~ 50%) of the input nitrogen (including dry/wet deposition and fertilizer) infiltrated into the soil, resulting in a poor fertilizer uptake efficiency of the tea tree. It was demonstrated that the modified fertilization strategy (apply fertilizer in small rainfall event, i.e., daily rainfall < 20 mm/day, and not in a single day) could increase the nitrogen uptake and harvest yield of the tea tree by 14% and 4%, respectively, with a 10% reduction in nitrogen input. Furthermore, this strategy significantly reduced the nitrogen yields from surface flow (75%), lateral flow (36%), percolation (50%), and groundwater (48%). A popular model with verified parameter values could help in developing a win-win strategy for both farmers and regulators, thus realizing the goals of sustainable agricultural practices.


Assuntos
Fertilizantes , Nitrogênio , Agricultura , Monitoramento Ambiental , Fazendas , Nitratos/análise , Nitrogênio/análise , Solo , Chá , Água
3.
Microb Pathog ; 157: 104964, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34022363

RESUMO

OBJECT: Fusobacterium nucleatum (F.nucleatum), a gram-negative, obligately anaerobe of oral commensal,has been regarded as culprit of periodontal diseases previously and is being unveiled as possible pathogen of gastrointestinal disorders. The key virulence factor of F.nucleatum is FadA adhesin for binding and invading of the host's epithelial cells. Here, we detected fecal F.nucleatum and virulence gene fadA in patients with ulcerative colitis(UC) and evaluated the clinical relevance with UC. METHODS AND SUBJECTS: A total of 310 subjects were enrolled including 100 patients with UC, 70 healthy controls (HC), 70 patients with irritable bowel syndrome subtype diarrhea(IBS-D), and 70 colorectal cancer patients(CRC). Stool samples of UC patients compared with healthy controls as well as IBS-D and CRC patients were collected for Polymerase Chain Reaction(PCR) detection of F.nucleatum (based on 16s rRNA) and virulence gene fadA. RESULTS: The detection rate of 16s rRNA based PCR for F.nucleatum of UC patients(39/100, 39.00%) and CRC(26/70, 37.14%) patients are significantly higher than HC (12/70, 17.14%, P < 0.01) and IBS-D patients (14/70, 20.00%, P < 0.01). Moreover, 19 samples were detected fadA positive from 39 F.nucleatum positive samples of UC patients (19/39, 48.72%), which is significantly higher than HC(2/12, 16.66%, P < 0.05). There were 3 samples detected fadA positive from 14 F.nucleatum positive samples of IBS-D patients(3/14, 21.43%) and 13 out of 26(50.00%) of CRC patients, which were both no significant differences compared with UC patients(21.4% vs 48.72%, P > 0.05; 50.00% vs 48.72%, P > 0.05). For both F.nucleatum and fadA gene positive patients, there were no statistical significances between erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), white blood cells(WBC), and hemoglobin compared with negative patients(defined by either F.nucleatum or fadA negative, or both negative). However, it is worth noting that detection rate of F.nucleatum with virulence gene fadA in patients of severe ulcerative colitis was significantly higher than patients with mild and moderate colitis(28.89% vs 10.91%, P < 0.05). In addition, the fecal F.nucleatum and fadA gene positive patients were more likely to have pancolitis other than left-sided colitis(pancolitis/left-sided colitis: 26.92% vs 10.42%, P < 0.05). CONCLUSIONS: The presence of F.nucleatum and fadA gene increased in UC patients, especially in patients with severe colitis and pancolitis. Strains of F.nucleatum harbored virulence gene fadA are suggested to play a role in the pathogenesis of UC.


Assuntos
Colite Ulcerativa , Fusobacterium nucleatum , Adesinas Bacterianas , Fusobacterium nucleatum/genética , Humanos , RNA Ribossômico 16S/genética , Virulência
4.
BMC Genomics ; 21(1): 229, 2020 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-32171242

RESUMO

BACKGROUND: Gene expression regulators identified in transcriptome profiling experiments may serve as ideal targets for genetic manipulations in farm animals. RESULTS: In this study, we developed a gene expression profile of 76,000+ unique transcripts for 224 porcine samples from 28 tissues collected from 32 animals using Super deepSAGE technology. Excellent sequencing depth was achieved for each multiplexed library, and replicated samples from the same tissues clustered together, demonstrating the high quality of Super deepSAGE data. Comparison with previous research indicated that our results not only have good reproducibility but also have greatly extended the coverage of the sample types as well as the number of genes. Clustering analysis revealed ten groups of genes showing distinct expression patterns among these samples. Our analysis of over-represented binding motifs identified 41 regulators, and we demonstrated a potential application of this dataset in infectious diseases and immune biology research by identifying an LPS-dependent transcription factor, runt-related transcription factor 1 (RUNX1), in peripheral blood mononuclear cells (PBMCs). The selected genes are specifically responsible for the transcription of toll-like receptor 2 (TLR2), lymphocyte-specific protein tyrosine kinase (LCK), and vav1 oncogene (VAV1), which belong to the T and B cell signaling pathways. CONCLUSIONS: The Super deepSAGE technology and tissue-differential expression profiles are valuable resources for investigating the porcine gene expression regulation. The identified RUNX1 target genes belong to the T and B cell signaling pathways, making them novel potential targets for the diagnosis and therapy of bacterial infections and other immune disorders.


Assuntos
Biologia Computacional/métodos , Perfilação da Expressão Gênica/veterinária , Redes Reguladoras de Genes , Sus scrofa/genética , Animais , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Regulação da Expressão Gênica , Leucócitos Mononucleares/química , Proteína Tirosina Quinase p56(lck) Linfócito-Específica/genética , Proteínas Proto-Oncogênicas c-vav/genética , Reprodutibilidade dos Testes , Suínos , Distribuição Tecidual , Receptor 2 Toll-Like/genética
5.
Emerg Infect Dis ; 26(1): 179-180, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31855529

RESUMO

China has made remarkable progress in reducing schistosomiasis caused by Schistosoma japonicum over the past 7 decades but now faces a severe threat from imported schistosomiasis. Results from national surveillance during 2010-2018 indicate integrating active surveillance into current surveillance models for imported cases is urgently needed to achieve schistosomiasis elimination in China.


Assuntos
Esquistossomose/epidemiologia , Adulto , Idoso , Animais , China/epidemiologia , Erradicação de Doenças , Humanos , Masculino , Pessoa de Meia-Idade , Esquistossomose/etiologia , Esquistossomose/parasitologia , Esquistossomose/prevenção & controle , Migrantes , Viagem
6.
Pestic Biochem Physiol ; 159: 51-58, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31400784

RESUMO

Isoquinoline alkaloids possess broad pharmacological activities. In this study, the antifungal activity of twelve isoquinoline alkaloids, including berberine (1), jatrorrhizine (2), coptisine (3), corydaline (4), tetrahydroberberine (5), chelidonine (6), dihydrosanguinarine (7), chelerythrine (8), sanguinarine (9), palmatine (10), tetrahydropalmatine (11) and columbamine (12) were evaluated against eight plant pathogenic fungi in vitro. All the tested compounds showed varying degrees of inhibition against the eight tested plant fungi. Among them, sanguinarine exhibited high antifungal activity (EC50 ranging from 6.96-59.36 µg/mL). It displayed the best inhibitory activity against Magnaporthe oryzae (EC50 = 6.96 µg/mL), compared with azoxystrobin (EC50 = 12.04 µg/mL), and significantly suppressed spore germination of M. oryzae with the inhibition rate reaching 100% (50 µg/mL). The optical microscopy and scanning electron microscopy observations revealed that after treating M. oryzae mycelia with sanguinarine at 10 µg/mL, the mycelia appeared curved, collapsed and the cell membrane integrity was eventually damaged. Furthermore, the reactive oxygen species production, mitochondrial membrane potential and nuclear morphometry of mycelia had been changed, and the membrane function and cell proliferation of mycelia were destroyed. These results will enrich our insights into action mechanisms of antifungal activity of sanguinarine against M. oryzae.


Assuntos
Alcaloides/farmacologia , Antifúngicos/farmacologia , Benzofenantridinas/farmacologia , Isoquinolinas/farmacologia , Berberina/análogos & derivados , Berberina/farmacologia , Alcaloides de Berberina/farmacologia , Magnaporthe/metabolismo , Magnaporthe/patogenicidade , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Testes de Sensibilidade Parasitária , Espécies Reativas de Oxigênio/metabolismo
7.
Med Res Rev ; 38(5): 1614-1660, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29485730

RESUMO

To follow-up on our prior Part I review, this Part II review summarizes and provides updated literature on novel quinoline and quinazoline alkaloids isolated during the period of 2009-2016, together with the biological activity and the mechanisms of action of these classes of natural products. Over 200 molecules with a broad range of biological activities, including antitumor, antiparasitic and insecticidal, antibacterial and antifungal, cardioprotective, antiviral, anti-inflammatory, hepatoprotective, antioxidant, anti-asthma, antitussive, and other activities, are discussed. This survey should provide new clues or possibilities for the discovery of new and better drugs from the original naturally occurring quinoline and quinazoline alkaloids.


Assuntos
Alcaloides/farmacologia , Quinazolinas/farmacologia , Quinolinas/farmacologia , Alcaloides/química , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Humanos , Substâncias Protetoras/química , Substâncias Protetoras/farmacologia , Quinazolinas/química , Quinolinas/química
8.
Med Res Rev ; 38(3): 775-828, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-28902434

RESUMO

Quinoline and quinazoline alkaloids, two important classes of N-based heterocyclic compounds, have attracted tremendous attention from researchers worldwide since the 19th century. Over the past 200 years, many compounds from these two classes were isolated from natural sources, and most of them and their modified analogs possess significant bioactivities. Quinine and camptothecin are two of the most famous and important quinoline alkaloids, and their discoveries opened new areas in antimalarial and anticancer drug development, respectively. In this review, we survey the literature on bioactive alkaloids from these two classes and highlight research achievements prior to the year 2008 (Part I). Over 200 molecules with a broad range of bioactivities, including antitumor, antimalarial, antibacterial and antifungal, antiparasitic and insecticidal, antiviral, antiplatelet, anti-inflammatory, herbicidal, antioxidant and other activities, were reviewed. This survey should provide new clues or possibilities for the discovery of new and better drugs from the original naturally occurring quinoline and quinazoline alkaloids.


Assuntos
Alcaloides/farmacologia , Quinazolinas/farmacologia , Quinolinas/farmacologia , Alcaloides/química , Animais , Humanos , Fatores Imunológicos/química , Fatores Imunológicos/farmacologia , Substâncias Protetoras/química , Substâncias Protetoras/farmacologia , Quinazolinas/química , Quinolinas/química
9.
Molecules ; 23(10)2018 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-30241413

RESUMO

In an attempt to find the neonicotinoid insecticides, twenty novel dihydropyridine derivatives were designed, "green" synthesized via one pot facile three-component reaction and evaluated for their bioactivities against Tetranychus cinnabarinus, Myzus persicae, Brevicoryne brassicae, Fusarium oxysporum f. sp. vasinfectum, Magnaporthe oryzae, Sclerotinia sclerotiorum and Botrytis cinereal. All of the tested compounds showed potent insecticidal activity, and some were much better in comparison with imidacloprid (IMI). Especially, compounds 3d (LC50: 0.011 mM) and 5c (LC50: 0.025 mM) were 12.2- and 5.4-fold more active than IMI (LC50: 0.135 mM) against T. cinnabarinus, respectively. Moreover, out of all the derivatives, compound 3d (LC50: 0.0015 mM) exhibited the strongest insecticidal activity against B. brassicae and compound 3i (LC50: 0.0007 mM) displayed the strongest insecticidal activity against M. persicae. Surprisingly, when the concentration of compound 4 was 50 mg/L, the inhibition rate against F. oxysporum and S. sclerotiorum reached 45.00% and 65.83%, respectively. The present work indicated that novel dihydropyridine derivatives could be used as potential lead compounds for developing neonicotinoid insecticides and agricultural fungicides.


Assuntos
Antifúngicos/síntese química , Di-Hidropiridinas/síntese química , Inseticidas/síntese química , Ácaros e Carrapatos/efeitos dos fármacos , Animais , Antifúngicos/química , Antifúngicos/farmacologia , Afídeos/efeitos dos fármacos , Di-Hidropiridinas/química , Di-Hidropiridinas/farmacologia , Fusarium/efeitos dos fármacos , Química Verde , Inseticidas/química , Inseticidas/farmacologia , Estrutura Molecular , Relação Estrutura-Atividade
10.
Small ; 13(24)2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28464447

RESUMO

The cellular internalization of rod-like nanoparticles (NPs) is investigated in a combined experimental and simulation study. These rod-like nanoparticles with smooth, abacus-like (i.e., beads-on-wires), and helical surface patterns are prepared by the cooperative self-assembly of poly(γ-benzyl-l-glutamate)-block-poly(ethylene glycol) (PBLG-b-PEG) block copolymers and PBLG homopolymers. All three types of NPs can be internalized via endocytosis. Helical NPs exhibit the best endocytic efficacy, followed by smooth NPs and abacus-like NPs. Coarse-grained molecular dynamics simulations are used to examine the endocytic efficiency of these NPs. The NPs with helical and abacus-like surfaces can be endocytosed via novel "standing up" (tip entry) and "gyroscope-like" (precession) pathways, respectively, which are distinct from the pathway of traditional NPs with smooth surfaces. This finding indicates that the cellular internalization capacity and pathways can be regulated by introducing stripe patterns (helical and abacus-like) onto the surface of rod-like NPs. The results of this study may lead to novel applications of biomaterials, such as advanced drug delivery systems.

11.
Biomacromolecules ; 18(3): 797-807, 2017 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-28125207

RESUMO

In this work, the interactions between block copolymer micelles (BCMs) and plasma membranes were investigated by performing coarse-grained molecular dynamics (CGMD) simulations. Different binding strengths between the BCMs and the membranes were tested, and four interaction pathways were discovered: attachment, semiendocytosis, endocytosis, and fusion. Endocytosis was the most efficient way for the BCMs to be taken up, and fusion could lead to cytotoxicity. Unlike rigid particles, deformation of the BCMs strongly affected the interaction pathways. We examined the effects of changing the aggregation number of the BCMs (Nagg), the chain length of the polymer (Nb), and the chain stiffness of the hydrophobic block (ka), and we learned that smaller Nagg and lower Nb could lead to weaker cellular uptake capacities, whereas larger Nagg and higher Nb gave rise to higher cytotoxicities. Moreover, a weaker chain stiffness of the hydrophobic block could be more favorable for obtaining BCMs with higher internalization efficacies and lower cytotoxicities. The results of these simulations could aid in the design of BCMs with desirable cellular internalization capacities and lower cytotoxicities. Such BCMs could be useful in drug-delivery systems.


Assuntos
Membrana Celular/química , Micelas , Polímeros/química , Sistemas de Liberação de Medicamentos , Interações Hidrofóbicas e Hidrofílicas , Modelos Moleculares , Simulação de Dinâmica Molecular
12.
Soft Matter ; 13(30): 5130-5136, 2017 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-28657106

RESUMO

P(FpC3P) (Fp: CpFe(CO)2; C3P: propyl diphenyl phosphine) has a helical backbone, resulting from piano stool metal coordination geometry, which is rigid with intramolecular aromatic interaction of the phenyl groups. The macromolecule is hydrophobic, but the polarized CO groups can interact with water for aqueous self-assembly. The stiffness of P(FpC3P), which is adjustable by temperature, is an important factor influencing the morphologies of kinetically trapped assemblies. P(FpC3P)7 self-assembles in DMSO/water (10/90 by volume) into lamellae at 25 °C, vesicles at 40 °C and irregular aggregates at higher temperatures (60 and 70 °C). The colloidal stability decreases in the order of lamellae, vesicles and irregular aggregates. Dissipative particle dynamics (DPD) simulation reveals the same temperature-dependent self-assembled morphologies with an interior of hydrophobic aromatic groups covered with the metal coordination units. The rigid backbone at 25 °C accounts for the formation of the layered morphology, while the reduced rigidity of the same P(FpC3P)7 at 40 °C curves up the lamellae into vesicles. At a higher temperature (60 or 70 °C), P(FpC3P)7 behaves as a random coil without obvious amphiphilic segregation, resulting in irregular aggregates. The stiffness is, therefore, a crucial factor for the aqueous assembly of macromolecules without obvious amphiphilic segregation, which is reminiscent of the solution behavior observed for many hydrophobic biological macromolecules such as proteins.

13.
Bioorg Med Chem Lett ; 27(8): 1750-1753, 2017 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-28285912

RESUMO

In an effort to discover potent camptothecin-derived antitumor agents, novel camptothecin analogues with sulfonylpiperazinyl motifs at position-7 were designed and synthesized. They were evaluated for in vitro cytotoxicity with the sulforhodamine-B (SRB) method in five types of human tumor cell lines, A-549, MDA-MB-231, KB, KB-VIN and MCF-7. With IC50 values in the low µM to nM level, most of the new analogues showed greater cytotoxicity activity than the reference compounds irinotecan and topotecan. Furthermore, compounds 12l (IC50, 1.2nM) and 12k (IC50, 20.2nM) displayed the highest cytotoxicity against the multidrug-resistant (MDR) KB-VIN cell line and merit further development as preclinical drug candidates for treating cancer, including MDR phenotype. Our study suggested that integration of sulfonylpiperazinyl motifs into position-7 of camptothecin is an effective strategy for discovering new potent cytotoxic camptothecin derivatives.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Camptotecina/análogos & derivados , Camptotecina/farmacologia , Piperazinas/química , Piperazinas/farmacologia , Antineoplásicos/síntese química , Camptotecina/síntese química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Desenho de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Metilação , Neoplasias/tratamento farmacológico , Piperazina , Piperazinas/síntese química , Sulfonas/síntese química , Sulfonas/química , Sulfonas/farmacologia
14.
Biometals ; 29(1): 25-37, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26645388

RESUMO

While indirect model has been widely accepted in bioleaching, but the evidence of cell surface iron speciation has not been reported. In the present work the iron speciation on the cell surfaces of four typically acidophilic iron-oxidizing microorganism (mesophilic Acidithiobacillus ferrooxidans ATCC 23270, moderately thermophilic Leptospirillum ferriphilum YSK and Sulfobacillus thermosulfidooxidans St, and extremely thermophilic Acidianus manzaensis YN25) grown on different energy substrates (chalcopyrite, pyrite, ferrous sulfate and elemental sulfur (S(0))) were studied in situ firstly by using synchrotron-based micro- X-ray fluorescence analysis and X-ray absorption near-edge structure spectroscopy. Results showed that the cells grown on iron-containing substrates had apparently higher surface iron content than the cells grown on S(0). Both ferrous iron and ferric iron were detected on the cell surface of all tested AIOMs, and the Fe(II)/Fe(III) ratios of the same microorganism were affected by different energy substrates. The iron distribution and bonding state of single cell of A. manzaensis were then studied in situ by scanning transmission soft X-ray microscopy based on dual-energy contrast analysis and stack analysis. Results showed that the iron species distributed evenly on the cell surface and bonded with amino, carboxyl and hydroxyl groups.


Assuntos
Acidianus/metabolismo , Acidithiobacillus/metabolismo , Metabolismo Energético , Ferro/metabolismo , Cobre/metabolismo , Compostos Ferrosos/metabolismo , Sulfetos/metabolismo , Propriedades de Superfície , Espectroscopia por Absorção de Raios X
15.
J Med Chem ; 67(6): 4560-4582, 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38502936

RESUMO

Inspired by the structure of dysoxylactam A (DLA) that has been demonstrated to reverse P-glycoprotein (P-gp)-mediated multidrug resistance (MDR) effectively, 61 structurally simplified cyclolipopeptides were thus designed and synthesized via an effective method, and their reversing P-gp-mediated MDR potentials were evaluated, which provided a series of more potent analogues and allowed us to explore their structure-activity relationship (SAR). Among them, a well-simplified compound, 56, with only two chiral centers that all derived from amino acids dramatically reversed drug resistance in KBV200 cells at 10 µM in combination with vinorelbine (VNR), paclitaxel (PTX), and adriamycin (ADR), respectively, which is more promising than DLA. The mechanism study showed that 56 reversed the MDR of tumor cells by inhibiting the transport function of P-gp rather than reducing its expression. Notably, compound 56 effectively restored the sensitivity of MDR tumors to VNR in vivo at a dosage without obvious toxicity.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP , Resistencia a Medicamentos Antineoplásicos , Lipopeptídeos , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Resistência a Múltiplos Medicamentos , Subfamília B de Transportador de Cassetes de Ligação de ATP , Doxorrubicina/farmacologia , Linhagem Celular Tumoral
16.
Biotechnol Lett ; 35(12): 2129-36, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23974497

RESUMO

Attachments of Acidithiobacillus ferrooxidans ATCC 23270 onto elemental sulfur, quartz and complex chalcopyrite were investigated by analysis of its extracellular polymeric substances as well as applying Langmuir and Freundlich equations. The two equations fitted the adsorption equilibrium data with significant correlation coefficient over 0.9. This indicated that bacterial attachment is complicated and involves Langmuir and Freundlich characterizations. Sulfur-grown cells showed the highest affinity for the three solid substrates. The investigated complex chalcopyrite possessed a higher maximum adsorption capacity for A. ferrooxidans than elemental sulfur or quartz. The Freundlich fitting parameters suggested that quartz had a weaker adsorption capacity and smaller adsorption areas than elemental sulfur or the complex chalcopyrite. It is not the content of total carbohydrates or proteins in EPS but their ratios that determine the affinity differences between cells and substrates.


Assuntos
Acidithiobacillus/metabolismo , Aderência Bacteriana/fisiologia , Cobre/metabolismo , Modelos Teóricos , Quartzo/metabolismo , Enxofre/metabolismo , Acidithiobacillus/química , Acidithiobacillus/citologia , Adsorção , Espaço Extracelular/química , Espaço Extracelular/metabolismo , Cinética , Modelos Lineares , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/metabolismo
17.
World J Gastrointest Oncol ; 15(8): 1317-1331, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37663937

RESUMO

Colitis-associated colorectal cancer (CAC) is defined as a specific cluster of colorectal cancers that develop as a result of prolonged colitis in patients with inflammatory bowel disease (IBD). Patients with IBD, including ulcerative colitis and Crohn's disease, are known to have an increased risk of developing CAC. Although the incidence of CAC has significantly decreased over the past few decades, individuals with CAC have increased mortality compared to individuals with sporadic colorectal cancer, and the incidence of CAC increases with duration. Chronic inflammation is generally recognized as a major contributor to the pathogenesis of CAC. CAC has been shown to progress from colitis to dysplasia and finally to carcinoma. Accumulating evidence suggests that multiple immune-mediated pathways, DNA damage pathways, and pathogens are involved in the pathogenesis of CAC. Over the past decade, there has been an increasing effort to develop clinical approaches that could help improve outcomes for CAC patients. Colonoscopic surveillance plays an important role in reducing the risk of advanced and interval cancers. It is generally recommended that CAC patients undergo endoscopic removal or colectomy. This review summarizes the current understanding of CAC, particularly its epidemiology, mechanisms, and management. It focuses on the mechanisms that contribute to the development of CAC, covering advances in genomics, immunology, and the microbiome; presents evidence for management strategies, including endoscopy and colectomy; and discusses new strategies to interfere with the process and development of CAC. These scientific findings will pave the way for the management of CAC in the near future.

18.
World J Gastroenterol ; 29(35): 5125-5137, 2023 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-37744294

RESUMO

BACKGROUND: Autoimmune pancreatitis (AIP) has been linked with elevated immunoglobulin (Ig) G4 levels. The characteristics and outcomes of AIP based on serum markers have not been fully evaluated. AIM: To compare clinical features, treatment efficacy, and outcome of AIP based on serum IgG4 levels and analyze predictors of relapse. METHODS: A total of 213 patients with AIP were consecutively reviewed in our hospital from 2006 to 2021. According to the serum IgG4 level, all patients were divided into two groups, the abnormal group (n = 148) with a high level of IgG4 [> 2 × upper limit of normal (ULN)] and the normal group (n = 65). The t-test or Mann-Whitney U test was used to compare continuous variables. Categorical parameters were compared by the χ2 test or Fisher's exact test. Kaplan-Meier curves and log-rank tests were established to assess the cumulative relapse rates. Univariate and multivariate analyses were used to investigate potential risk factors of AIP relapse. RESULTS: Compared with the normal group, the abnormal group had a higher average male age (60.3 ± 10.4 vs 56.5 ± 12.9 years, P = 0.047); higher level of serum total protein (72.5 ± 7.9 g/L vs 67.2 ± 7.5 g/L, P < 0.001), IgG4 (1420.5 ± 1110.9 mg/dL vs 252.7 ± 106.6 mg/dL, P < 0.001), and IgE (635.6 ± 958.1 IU/mL vs 231.7 ± 352.5 IU/mL, P = 0.002); and a lower level of serum complement C3 (100.6 ± 36.2 mg/dL vs 119.0 ± 45.7 mg/dL, P = 0.050). In addition, a lower number of cases with abnormal pancreatic duct and pancreatic atrophy (23.6% vs 37.9%, P = 0.045; 1.6% vs 8.6%, P = 0.020, respectively) and a higher rate of relapse (17.6% vs 6.2%, P = 0.030) were seen in the abnormal group. Multivariate analyses revealed that serum IgG4 [(> 2 × ULN), hazard ratio (HR): 3.583; 95% confidence interval (CI): 1.218-10.545; P = 0.020] and IgA (> 1 × ULN; HR: 5.908; 95%CI: 1.199-29.120; P = 0.029) and age > 55 years (HR: 2.383; 95%CI: 1.056-5.378; P = 0.036) were independent risk factors of relapse. CONCLUSION: AIP patients with high IgG4 levels have clinical features including a more active immune system and higher relapse rate. Several factors, such as IgG4 and IgA, are associated with relapse.


Assuntos
Pancreatite Autoimune , Humanos , Masculino , Adulto , Pessoa de Meia-Idade , Idoso , Estudos Retrospectivos , Hospitais , Imunoglobulina G , Imunoglobulina A
19.
Sci Adv ; 9(23): eadf0284, 2023 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-37285430

RESUMO

It is known that post-retrieval extinction but not extinction alone could erase fear memory. However, whether the coding pattern of original fear engrams is remodeled or inhibited remains largely unclear. We found increased reactivation of engram cells in the prelimbic cortex and basolateral amygdala during memory updating. Moreover, conditioned stimulus- and unconditioned stimulus-initiated memory updating depends on the engram cell reactivation in the prelimbic cortex and basolateral amygdala, respectively. Last, we found that memory updating causes increased overlapping between fear and extinction cells, and the original fear engram encoding was altered during memory updating. Our data provide the first evidence to show the overlapping ensembles between fear and extinction cells and the functional reorganization of original engrams underlying conditioned stimulus- and unconditioned stimulus-initiated memory updating.


Assuntos
Complexo Nuclear Basolateral da Amígdala , Memória , Memória/fisiologia , Medo/fisiologia , Condicionamento Clássico/fisiologia , Condicionamento Operante
20.
Nanomaterials (Basel) ; 12(15)2022 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-35957153

RESUMO

Multi-component nitride thin films usually show high hardness and good wear resistance due to the nanoscale structure and solid-solution strengthening effect. However, the state of N atoms in the thin film and its effects on the compressive strength is still unclear. In this work, (AlTiVCr)N multi-component nitride thin films with a face-centered cubic (FCC) structure prepared by the direct current magnetron sputtering method exhibit a superior strength of ~4.5 GPa and final fracture at a strain of ~5.0%. The excellent mechanical properties are attributed to the synergistic effects of the nanocrystalline structure, covalent bonding between N and metal atoms, and interstitial strengthening. Our results could provide an intensive understanding of the relationship between microstructure and mechanical performances for multi-component nitride thin films, which may promote their applications in micro- and nano-devices.

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