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1.
Small ; 20(5): e2305948, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37759414

RESUMO

The large-scale commercialization of the hydrogen evolution reaction (HER) necessitates the development of cost-effective and highly efficient electrocatalysts. Although transition metal sulfides, such as MoS2 and Ni3 S2 , hold great potential in the field of HER, their catalytic performance has been unsatisfactory due to incomplete exposure of active sites and poor electrical conductivity. In this work, via a simple hydrothermal strategy, amorphous MoS2 nanoshells in the form of urchin-like MoS2 -Ni3 S2 core-shell heterogeneous structure is realized and in situ loaded on nickel foam (A-MoS2 -Ni3 S2 -NF). In particular, XPS analysis results show that the coupling of amorphous MoS2 and Ni3 S2 makes the electrode surface exhibit electron-abundant property, which will have a positive impact on HER catalytic activity. In addition, the fully exposed active site of amorphous MoS2 is another crucial factor contributing to its high catalytic performance of A-MoS2 -Ni3 S2 -NF electrode. In particular, at a current density of 10 mA cm⁻2 , the overpotential of electrode is 95 mV (1.0 m KOH) and 145 mV (0.5 m H2 SO4 ). This work highlights the importance of amorphous MoS2 and MoS2 -Ni3 S2 of sea-urchin core-shell structure in optimizing HER performance, which provides an important reference for HER research.

2.
Int J Med Mushrooms ; 18(8): 651-660, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27910783

RESUMO

The medicinal mushroom Trametes versicolor has been well recognized for its activity in maintaining the general health of the population and in managing and treating human diseases in various cultures. Its use has been recently gaining acceptance and popularity in Western countries. The reported health benefits of T. versicolor led to a search for the identity of its bioactive ingredients. These efforts have resulted in the isolation of the polysaccharopeptide PSP from cultured mycelia of strain Cov-1, which expresses large amounts of PSP. The availability of highly purified PSP was followed by studies of its biological activities using tissue culture models and limited human clinical trials. In this review we summarize recent advances in the antitumorigenic and immunomodulatory effects of PSP, elimination of prostate cancer stem cells and control of the intestinal microbiome, and its interplay with host cells as a prebiotic. These findings may have implications for widening and repurposing the use of PSP.


Assuntos
Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Microbioma Gastrointestinal/efeitos dos fármacos , Células-Tronco Neoplásicas/efeitos dos fármacos , Proteoglicanas/farmacologia , Trametes/química , Antibacterianos/química , Antineoplásicos/química , Humanos , Proteoglicanas/química
3.
Wei Sheng Wu Xue Bao ; 47(4): 628-33, 2007 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-17944362

RESUMO

Five Ganoderma species, including G. lucidum, G. tsugae, G. oerstedii, G. resinaceum and G. subamboinens, were parallel studied under an identical condition. These species were cultivated using liquid fermentation and their mycelia polysaccharides were extracted and compared on the physical/chemical properties and in vitro immunomodulatory activities. These results showed that the polysaccharide yields varied markedly among different species, and G. oerstedii was the highest among the five. However, HPLC analysis showed all the polysaccharide extracts had similar molecular weight distributions and monosaccharide compositions. They all contained glucose, galactose, mannose, glucosamine hydrochloride and fucose. In vitro assays, these polysaccharide extracts significantly stimulated phagocytosis and nitric oxide production by RAW 264.7 macrophage cell line, and G. subamboinens exerted the strongest potency. When Con A was not or presented, they all showed an up-or-down immunomodulatory effect on mouse splenocyte proliferation. The results illustrate that in addition to G. lucidum and G. tsugae, which are the two mostly studied and applied species, other Ganoderma species can also produce polysaccharides with similar physical/chemical properties and with similar immunomodulatory activities.


Assuntos
Ganoderma/química , Ganoderma/imunologia , Polissacarídeos/química , Polissacarídeos/imunologia , Animais , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Peso Molecular , Micélio/química , Micélio/imunologia , Polissacarídeos/farmacologia
4.
World J Gastroenterol ; 8(3): 493-5, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12046077

RESUMO

AIM: Ursolic acid (UA) and oleanolic acid (OA) are triperpene acids having a similar chemical structure and are distributed wildly in plants all over the world. In recent years, it was found that they had marked anti-tumor effects. There is little literature currently available regarding their effects on colon carcinoma cells. The present study was designed to investigate their inhibitory effects on human colon carcinoma cell line HCT15. METHODS: HCT15 cells were cultured with different drugs. The treated cells were stained with hematoxylin-eosin and their morphologic changes observed under a light microscope. The cytotoxicity of these drugs was evaluated by tetrazolium dye assay. Cell cycle analysis was performed by flow cytometry (FCM). Data were expressed as means +/-SEM and Analysis of variance and Student' t-test for individual comparisons. RESULTS: Twenty-four to 72 h after UA or OA 60 micromol/L treatment, the numbers of dead cells and cell fragments were increased and most cells were dead at the 72nd hour. The cytotoxicity of UA was stronger than that of OA. Seventy-eight hours after 30 micromol/L of UA or OA treatment, a number of cells were degenerated, but cell fragments were rarely seen. The IC(50) values for UA and OA were 30 and 60 micromol/L, respectively. Proliferation assay showed that proliferation of UA and OA-treated cells was slightly increased at 24h and significantly decreased at 48 h and 60 h, whereas untreated control cells maintained an exponential growth curve. Cell cycle analysis by FCM showed HCT15 cells treated with UA 30 and OA 60 for 36 h and 72 h gradually accumulated in G(0)/G(1) phase (both drugs P<0.05 for 72 h), with a concomitant decrease of cell populations in S phase (both drugs P<0.01 for 72 h) and no detectable apoptotic fraction. CONCLUSION: UA and OA have significant anti-tumor activity. The effect of UA is stronger than that of OA. The possible mechanism of action is that both drugs have an inhibitory effect on tumor cell proliferation through cell-cycle arrest.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Neoplasias do Colo/tratamento farmacológico , Ácido Oleanólico/farmacologia , Triterpenos/farmacologia , Ciclo Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Neoplasias do Colo/patologia , Humanos , Células Tumorais Cultivadas , Ácido Ursólico
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