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1.
ACS Appl Mater Interfaces ; 15(2): 3476-3485, 2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36621816

RESUMO

Pressure sensing is highly demanding in wearable devices, robotics, and artificial intelligence, whereas it is still a big challenge to develop a pressure sensor with an excellent linear response in a broad detection range. Herein, a flexible and porous carbon nanotube (CNT)/carbon black (CB)/carbonyl iron powder (CIP)/silicone composite is proposed by a simple strategy of mixing, curing, and washing. Due to the porous structure induced by the sacrifice of sugar particles, an excellent linear response (R2 = 0.999) is achieved for the composite sensor by manipulating the contributions of contact resistance and tunnel resistance to the sensing performance via the alternation of CB and CNT contents. Moreover, the porous structure donates the composite sensor a low compressive modulus at a low pressure level, while the CIPs introduced lead to a high compressive modulus at a high pressure level with the assistance of an external magnetic field. As a result, the sensor produced has a wide linear response range of 80 Pa to 220 kPa, much wider than most of the linear response pressure sensors reported previously. The wide detection range is demonstrated by cyclic pressure tests in the frequency range of 0.1-5 Hz, durability tests, and monitoring human or robot motions including breathing, walking, lifting, and boxing, etc. Taking the advantages of low cost, high sensitivity, and excellent linear response in a wide pressure range, the current composite sensor is promising for precise monitoring of human motions and delicate controlling of robots.


Assuntos
Nanotubos de Carbono , Dispositivos Eletrônicos Vestíveis , Humanos , Inteligência Artificial , Nanotubos de Carbono/química , Porosidade , Pressão
2.
Bioorg Chem ; 131: 106305, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36495679

RESUMO

Phytochemical investigation on the rhizomes of Paris fargesii var. petiolata (Baker ex C. H. Wright) Wang et Tang led to the isolation of five previously undescribed steroidal saponins, parpetiosides A-E (1-5), and six known analogs (6-11). Their structures were established by extensive spectroscopic data analysis and chemical methods. Compound 5 was a rare steroidal saponin with disaccharide moiety linked at C-26 of dehydrokryptogenin that was hardly seen in the genus Paris. The cytotoxicities of the isolated compounds against three human cancer cell lines (U87, HepG2 and SGC-7901) were evaluated, and compound 1 displayed certain inhibitory effect with IC50 values of 8.02 ± 0.45, 8.24 ± 0.57 and 6.20 ± 0.79 µM, respectively. Moreover, the preliminary mechanism of 1 inhibiting the proliferation of the three cancer cell lines might be related to cell cycle distribution and the induction of S phase arrest.


Assuntos
Antineoplásicos , Liliaceae , Neoplasias , Saponinas , Humanos , Rizoma/química , Antineoplásicos/farmacologia , Antineoplásicos/análise , Liliaceae/química , Esteroides/farmacologia , Esteroides/química , Saponinas/farmacologia , Saponinas/química
3.
Aquat Toxicol ; 252: 106318, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36206702

RESUMO

Mitochondria are recognized as an important target organelle for the toxicity of nanomaterials. Although the toxic effects of silver nanoparticles (AgNPs) on mitochondria have been widely reported, the mechanism behind the toxicity remains unclear. In this study, the effects of two forms of silver (AgNPs and AgNO3) on carp gill mitochondria were investigated by analyzing the mitochondrial ultrastructure, physicochemical properties of mitochondrial membrane, and mitochondrial proteomics. After exposure of common carp to AgNPs (0.75 mg/L) and AgNO3 (0.05 mg/L) for 96 h, both forms of silver were shown to cause gill mitochondrial lesions, including irregular shape, loss of mitochondrial cristae, and increased mitochondrial membrane permeability. Proteomics results revealed that AgNPs and AgNO3 induced 362 and 297 differentially expressed proteins (DEPs) in gill mitochondria, respectively. Among the DEPs, 244 were shared between AgNPs and AgNO3 treatments. These shared proteins were mainly distributed in the mitochondrial membrane and matrix, and were significantly enriched in the tricarboxylic acid (TCA) cycle and oxidative phosphorylation pathway. The functional annotation of DEPs induced by both silver forms was mainly involved in energy production and conversion. These results indicated that the toxic mechanism of AgNPs and AgNO3 on gill mitochondria were comparable and the two forms of silver caused mitochondrial dysfunction in fish gills by inhibiting the TCA cycle and disrupting the electron transport chain.


Assuntos
Carpas , Nanopartículas Metálicas , Poluentes Químicos da Água , Animais , Nitrato de Prata/toxicidade , Brânquias , Nanopartículas Metálicas/química , Proteômica , Poluentes Químicos da Água/toxicidade , Prata/toxicidade , Prata/metabolismo , Corantes/metabolismo , Corantes/farmacologia , Ácidos Tricarboxílicos/metabolismo , Ácidos Tricarboxílicos/farmacologia
4.
Aquat Toxicol ; 237: 105895, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34147820

RESUMO

Toxic effects of silver nanoparticles (AgNPs) on fish gills have been widely reported but the recoverability of AgNPs-induced fish gill injuries is still unknown. In this study, combined multiomics and conventional toxicological analytical methods were used to investigate the changes in the gills of common carp responses to AgNPs (0.1 mg/L) toxicity after 24 h exposure and 7-day recovery. Conventional toxicological results showed that AgNPs exposure significantly increased silver content in gills and caused epithelial hyperplasia and lamellar fusion. After the recovery period, the silver content in fish gills significantly decreased; accompanied by the disappearance of histopathological characteristics in fish gills. Multiomics results revealed that AgNPs exposure resulted in the differential expression of 687 genes and 96 metabolites in fish gills. These differentially expressed genes (DEGs) and metabolites mainly participate in amino acid, carbohydrate, and lipid metabolisms, and are significantly enriched in the tricarboxylic acid (TCA) cycle. After the recovery period, the number of DEGs and metabolites in gills decreased to 33 and 90, respectively. Moreover, DEGs and metabolites in the TCA cycle recovered to control levels. In summary, the present study found that AgNPs-induced fish gill toxicity showed potential recoverability at molecular and phenotype levels.


Assuntos
Carpas , Nanopartículas Metálicas , Poluentes Químicos da Água , Animais , Brânquias/química , Metabolômica , Nanopartículas Metálicas/toxicidade , Prata/análise , Prata/toxicidade , Transcriptoma , Poluentes Químicos da Água/toxicidade
5.
Sci Rep ; 9(1): 15384, 2019 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-31659227

RESUMO

Bhutanitis thaidina is an endemic, rare, and protected swallowtail in China. Deforestation, habitat fragmentation, illegal commercialised capture, and exploitation of larval food plants are believed to be the four major causes of population decline of B. thaidina in the recent decade. However, little attention was paid to the impact of climate change. This study used ecological niche factor analysis and species distribution model to analyse the current suitable areas for B. thaidina with BioClim variables as well as its future suitable areas under four future climate scenarios (represented by four Representative Concentration Pathways: RCP2.6, RCP4.5, RCP6.0, and RCP8.5). Statistical analysis was carried out to compare the possible area and altitude changes to the distribution of B. thaidina under changing climate. Our analyses showed that the suitable areas for B. thaidina are fragmented under the current climate, with four suitable centres in northwestern Yunnan, northeastern Yunnan and northwestern Guizhou, the western margin of Sichuan Basin, and Qinling mountains. Apart from further habitat fragmentation under climate change, slight range expansion (average 6.0-8.9%) was detected under the RCP2.6 and RCP4.5 scenarios, while more range contraction (average 1.3-26.9%) was detected under the RCP6.0 and RCP8.5 scenarios, with the two southern suitable centres suffering most. Also, a tendency of contraction (2,500-3,500 m) and upslope shift (~600 m) in suitable altitude range were detected. The findings of this study supported the climate-vulnerable hypothesis of B. thaidina, especially under future climate like the RCP6.0 and RCP8.5 scenarios, in terms of contraction in suitable areas and altitude ranges. Conservation priority should be given to northwestern Yunnan, northeastern Yunnan, and northwestern Guizhou to alleviate the stress of massive habitat loss and extinction. Refugial areas should be established in all four suitable centres to maintain genetic diversity of B. thaidina in China.


Assuntos
Mudança Climática , Ecossistema , Espécies em Perigo de Extinção , Lepidópteros/fisiologia , Distribuição Animal , Animais , China , Lepidópteros/genética , Polimorfismo Genético
6.
Ying Yong Sheng Tai Xue Bao ; 19(10): 2194-200, 2008 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-19123355

RESUMO

With seedling's transplanting experiment under different water levels, this paper studied the growth responses of belowground modules of Carex lasiocarpa to various water regimes and water experiences in Sanjiang Plain. The results showed that the belowground modules of C. lasiocarpa had significantly different responses to water regimes. At thriving stage, the length of rhizome and adventitious root decreased with increasing water level, and until later growth stage, the maximal value still appeared under drought condition. However, under dry-wet alternate condition, the length of rhizome and adventitious root increased most from thriving stage to the end, indicating that stable and lower water level could improve the growth of rhizome and adventitious root. The biomass of rhizome, adventitious root, and belowground part were maximal under dry-wet alternate condition at both growth stages. For those with different water experiences, the ones undergoing alternate condition in early growth season and then drought had maximal rhizome biomass, and the others under sustained alternate condition had maximal adventitious root and belowground biomass. More biomass was distributed to rhizome in the later growth season under various water regimes. The percentage of rhizome in total biomass was significantly higher under drought condition than under other water conditions through the growth season. Besides, C. lasiocarpa grew slowly when submerged, but could recover through rhizomatic reproduction after the stress disappeared.


Assuntos
Carex (Planta)/crescimento & desenvolvimento , Raízes de Plantas/crescimento & desenvolvimento , Plântula/crescimento & desenvolvimento , Água/metabolismo , Biomassa , China
7.
Ying Yong Sheng Tai Xue Bao ; 18(11): 2432-7, 2007 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-18260443

RESUMO

With simulation test, this paper studied the effects of water level on the rhizomati germination and growth of Calamagrostis angustifolia and Carex lasiocarpa, the two typical wetland plants in Sanjiang Plain. The results showed that these two plants had different responses to water level. The population density, mean height, and maximum height of C. angustifolia reached the peak at 0 cm water level; while the mean and maximum height of C. lasiocarpa increased, but its population density decreased with increasing water level. At the early stage of germination, definite duration without inundation promoted the rhizomatic germination of these two plants, while continuous inundation constrained it. During growth period, excess inundation limited the growth of C. angustifolia, but C. lasiocarpa grew better under deeper water. Drought constrained the growth of C. angustifolia and C. lasiocarpa, and possibly, changed their life history.


Assuntos
Ecossistema , Raízes de Plantas/crescimento & desenvolvimento , Poaceae/crescimento & desenvolvimento , Água/análise , Áreas Alagadas , Carex (Planta)/crescimento & desenvolvimento , China , Solo/análise , Especificidade da Espécie
8.
World J Gastroenterol ; 11(16): 2477-81, 2005 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-15832421

RESUMO

AIM: One-week triple therapy with proton pump inhibitors, clarithromycin and amoxicillin has recently been proposed as the first-line treatment for Helicobacter pylori (H. pylori) infection; however, data regarding the effects of this regimen in China are scarce. The aim of this prospective and randomized study was to compare the efficacy of clarithromycin and metronidazole when they were combined with omeprazole and amoxicillin on eradication of H. pylori and ulcer healing in Chinese peptic ulcer patients. METHODS: A total of 103 subjects with H. pylori-positive peptic ulcer were randomly divided into two groups, and accepted triple therapy with omeprazole 20 mg, amoxicillin 1000 mg and either clarithromycin 500 mg (OAC group, n = 58) or metronidazole 400 mg (OAM group, n = 45). All drugs were given twice daily for 7 d. Patients with active peptic ulcer were treated with omeprazole 20 mg daily for 2-4 wk after anti-H. pylori therapy. Six to eight weeks after omeprazole therapy, all patients underwent endoscopies and four biopsies (two from the antrum and two others from the corpus of stomach) were taken for rapid urease test and histological analysis (with modified Giemsa staining) to examine H. pylori. Successful eradication was defined as negative results from both examination methods. RESULTS: One hundred patients completed the entire course of therapy and returned for follow-up. The eradication rate of H. pylori for the per-protocol analysis was 89.3% (50/56) in OAC group and 84.1% (37/44) in OAM group. Based on the intention-to-treat analysis, the eradication rate of H. pylori was 86.2% (50/58) in OAC group and 82.2% (37/45) in OAM group. There were no significant differences in eradication rates between the two groups on either analysis. The active ulcer-healing rate was 96.7% (29/30) in OAC group and 100% (21/21) in OAM group (per-protocol analysis, P>0.05). Six patients in OAC group (10.3%) and five in OAM group (11.1%) reported adverse events (P>0.05). CONCLUSION: One-week triple therapy with omeprazole and amoxicillin in combination with either clarithromycin or metronidazole is effective for the eradication of H. pylori. The therapeutic regimen comprising metronidazole with low cost, good compliance and mild adverse events may offer a good choice for the treatment of peptic ulcers associated with H. pylori infection in China.


Assuntos
Antibacterianos/administração & dosagem , Antiulcerosos/administração & dosagem , Claritromicina/administração & dosagem , Infecções por Helicobacter/tratamento farmacológico , Helicobacter pylori , Omeprazol/administração & dosagem , Adulto , Antibacterianos/efeitos adversos , Anti-Infecciosos/administração & dosagem , Anti-Infecciosos/efeitos adversos , Antiulcerosos/efeitos adversos , Povo Asiático , Claritromicina/efeitos adversos , Quimioterapia Combinada , Feminino , Humanos , Masculino , Metronidazol/administração & dosagem , Metronidazol/efeitos adversos , Pessoa de Meia-Idade , Omeprazol/efeitos adversos , Úlcera Péptica/tratamento farmacológico , Úlcera Péptica/microbiologia
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