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1.
Nature ; 600(7887): 81-85, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34853456

RESUMO

Understanding the structure and dynamic process of water at the solid-liquid interface is an extremely important topic in surface science, energy science and catalysis1-3. As model catalysts, atomically flat single-crystal electrodes exhibit well-defined surface and electric field properties, and therefore may be used to elucidate the relationship between structure and electrocatalytic activity at the atomic level4,5. Hence, studying interfacial water behaviour on single-crystal surfaces provides a framework for understanding electrocatalysis6,7. However, interfacial water is notoriously difficult to probe owing to interference from bulk water and the complexity of interfacial environments8. Here, we use electrochemical, in situ Raman spectroscopic and computational techniques to investigate the interfacial water on atomically flat Pd single-crystal surfaces. Direct spectral evidence reveals that interfacial water consists of hydrogen-bonded and hydrated Na+ ion water. At hydrogen evolution reaction (HER) potentials, dynamic changes in the structure of interfacial water were observed from a random distribution to an ordered structure due to bias potential and Na+ ion cooperation. Structurally ordered interfacial water facilitated high-efficiency electron transfer across the interface, resulting in higher HER rates. The electrolytes and electrode surface effects on interfacial water were also probed and found to affect water structure. Therefore, through local cation tuning strategies, we anticipate that these results may be generalized to enable ordered interfacial water to improve electrocatalytic reaction rates.

2.
Dev Biol ; 496: 36-51, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36736605

RESUMO

Urp1 and Urp2 are two neuropeptides, members of the Urotensin 2 family, that have been recently involved in the control of body axis morphogenesis in zebrafish. They are produced by a population of sensory spinal neurons, called cerebrospinal fluid contacting neurons (CSF-cNs), under the control of signals relying on the Reissner fiber, an extracellular thread bathing in the CSF. Here, we have investigated further the function of Urp1 and Urp2 (Urp1/2) in body axis formation and maintenance. We showed that urp1;urp2 double mutants develop strong body axis defects during larval growth, revealing the redundancy between the two neuropeptides. These defects were similar to those previously reported in uts2r3 mutants. We observed that this phenotype is not associated with congenital defects in vertebrae formation, but by using specific inhibitors, we found that, at least in the embryo, the action of Urp1/2 signaling depends on myosin II contraction. Finally, we provide evidence that while the Urp1/2 signaling is functioning during larval growth, it is dispensable for embryonic development. Taken together, our results show that Urp1/2 signaling is required in larvae to promote correct vertebral body axis, most likely by regulating muscle tone.


Assuntos
Neuropeptídeos , Peixe-Zebra , Animais , Larva , Coluna Vertebral , Morfogênese , Proteínas de Peixe-Zebra
3.
BMC Microbiol ; 24(1): 358, 2024 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-39304812

RESUMO

BACKGROUND: Nocardiosis, despite its rarity and underreporting, is significant due to its severe impact, characterized by high morbidity and mortality rates. The development of a precise, reliable, rapid, and straightforward technique for identifying the pathogenic agent in clinical specimens is crucial to reduce fatality rates and facilitate timely antimicrobial treatment. In this study, we aimed to identify Nocardia spp. in clinical isolates, using MALDI-TOF MS as the primary method, with molecular methods as the gold standard. Clinical Nocardia isolates were identified using 16S rRNA/hsp65/gyrB/secA1/rpoB gene sequencing. Identification performance of the Bruker MALDI Biotyper 3.1 (V09.0.0.0_8468) and MBT Compass 4.1 (V11.0.0.0_10833) for Nocardia identification was evaluated. RESULTS: Seventy-six Nocardia isolates were classified into 12 species through gene sequencing. The MALDI Biotyper 3.1 (V09.0.0.0_8468) achieved 100% genus-level accuracy and 84.2% species accuracy (64/76). The MBT Compass 4.1 with the BDAL Database (V11.0.0.0_10833) improved species identification to 98.7% (75/76). The updated database enhanced species level identification with scores > 1.7, increasing from 77.6% (59/76) to 94.7% (72/76), a significant improvement (P = 0.001). The new and simplified extraction increased the proportion of strains identified to the species level with scores > 1.7 from 62.0% (18/29) to 86.2% (25/29) (P = 0.016). An in-house library construction ensured accurate species identification for all isolates. CONCLUSIONS: The Bruker mass spectrometer can accurately identify Nocardia species, albeit with some variations observed between different database versions. The MALDI Biotyper 3.1 (V09.0.0.0_8468) has limitations in identifying Nocardia brasiliensis, with some strains only identifiable to the genus level. MBT Compass 4.1 (V11.0.0.0_10833) effectively addresses this shortfall, improving species identification accuracy to 98.7%, and offering quick and reliable identification of Nocardia. Both database versions incorrectly identified the clinically less common Nocardia sputorum as Nocardia araoensis. For laboratories that have not upgraded their databases and are unable to achieve satisfactory identification results for Nocardia, employing the new and simplified extraction method can provide a degree of improvement in identification outcomes.


Assuntos
Nocardiose , Nocardia , RNA Ribossômico 16S , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Nocardia/classificação , Nocardia/genética , Nocardia/isolamento & purificação , Nocardia/química , Nocardiose/microbiologia , Nocardiose/diagnóstico , Humanos , RNA Ribossômico 16S/genética , DNA Bacteriano/genética , Análise de Sequência de DNA/métodos , Técnicas de Tipagem Bacteriana/métodos , Proteínas de Bactérias/genética
4.
Angew Chem Int Ed Engl ; : e202408736, 2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-39107260

RESUMO

The electrooxidation of catalyst surfaces is across various electrocatalytic reactions, directly impacting their activity, stability and selectivity. Precisely characterizing the electrooxidation on well-defined surfaces is essential to understanding electrocatalytic reactions comprehensively. Herein, we employed in situ Raman spectroscopy to monitor the electrooxidation process of palladium single crystal. Our findings reveal that the Pd surface's initial electrooxidation process involves forming *OH intermediate and ClO4 - ions facilitate the deprotonation process, leading to the formation of PdOx. Subsequently, under deep electrooxidation potential range, the oxygen atoms within PdOx contribute to creating surface-bound peroxide species, ultimately resulting in oxygen generation. The adsorption strength of *OH and the coverage of ClO4 - can be adjusted by the controllable electronic effect, resulting in different oxidation rates. This study offers valuable insights into elucidating the electrooxidation mechanisms underlying a range of electrocatalytic reactions, thereby contributing to the rational design of catalysts.

5.
Skin Res Technol ; 29(6): e13389, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37357650

RESUMO

BACKGROUND: Keloids and hypertrophic scars frustrate patients by the deformity of appearance and organ dysfunction. Many modalities had been tried in clinic practice, but the results are unsatisfied. OBJECTIVE: We retrospectively analysed the combined application of bleomycin and triamcinolone for the treatment of keloids and hypertrophic scars. METHODS: The combination of bleomycin and triamcin acetonide was applied to the treatment of keloids and hypertrophic scars, 86 cases accepted the treatment. Follow-up 2-5 years after treatment. RESULTS: (1) The pain of scars and itching symptoms have basically subsided through treatment. (2) After drug injection treatment, the keloid began to shrink, some of the keloids disappeared. (3) Small keloids did not recur after treatment. Large keloids had local recurrence after treatment. When further treatment was given, the recurrence disappeared. CONCLUSION: The combined application of bleomycin and triamcin acetonide can effectively cure keloids and hypertrophic scars.


Assuntos
Cicatriz Hipertrófica , Queloide , Humanos , Queloide/tratamento farmacológico , Queloide/patologia , Cicatriz Hipertrófica/tratamento farmacológico , Cicatriz Hipertrófica/patologia , Bleomicina/uso terapêutico , Triancinolona/uso terapêutico , Estudos Retrospectivos , Injeções Intralesionais , Resultado do Tratamento
6.
Proc Natl Acad Sci U S A ; 117(1): 727-732, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31871204

RESUMO

The intine, the inner layer of the pollen wall, is essential for the normal development and germination of pollen. However, the composition and developmental regulation of the intine in rice (Oryza sativa) remain largely unknown. Here, we identify a microRNA, OsmiR528, which regulates the formation of the pollen intine and thus male fertility in rice. The mir528 knockout mutant aborted pollen development at the late binucleate pollen stage, significantly decreasing the seed-setting rate. We further demonstrated that OsmiR528 affects pollen development by directly targeting the uclacyanin gene OsUCL23 (encoding a member of the plant-specific blue copper protein family of phytocyanins) and regulating intine deposition. OsUCL23 overexpression phenocopied the mir528 mutant. The OsUCL23 protein localized in the prevacuolar compartments (PVCs) and multivesicular bodies (MVBs). We further revealed that OsUCL23 interacts with a member of the proton-dependent oligopeptide transport (POT) family of transporters to regulate various metabolic components, especially flavonoids. We propose a model in which OsmiR528 regulates pollen intine formation by directly targeting OsUCL23 and in which OsUCL23 interacts with the POT protein on the PVCs and MVBs to regulate the production of metabolites during pollen development. The study thus reveals the functions of OsmiR528 and an uclacyanin during pollen development.


Assuntos
Metaloproteínas/genética , MicroRNAs/metabolismo , Oryza/fisiologia , Proteínas de Plantas/genética , Pólen/metabolismo , Regulação da Expressão Gênica de Plantas , Microscopia Eletrônica de Transmissão , Plantas Geneticamente Modificadas , Pólen/ultraestrutura
7.
J Environ Manage ; 325(Pt B): 116557, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36308952

RESUMO

The impact of climate change on nearshore coastal water quality and its interaction with pollution prevention efforts (e.g., the development of green and gray water infrastructure) still lack systematic investigation. This study performed a holistic analysis of the impact of climate change on the salinity and concentrations of total nitrogen (TN), total phosphorus (TP) and chlorophyll a (Chl.a) in Shenzhen Bay between Shenzhen and Hong Kong, the two most developed megacities in South China, based on three-dimensional hydrodynamic and water quality modeling. The major study findings were as follows. First, Chl.a was the most sensitive parameter, and its bay-wide average concentration in 2100 was predicted to be approximately 13% and 46% higher than those in 2015 under mild and rapid climate change scenarios, respectively. Second, sea level rise was found to be a major driver of all four water quality parameters, while temperature and radiation mainly influenced Chl.a and precipitation mainly influenced nutrients. Third, water quality responses to climate change were highly heterogeneous over the bay. Even under a mild climate change scenario, the highest location-specific changes (2100 vs. 2015) in salinity and TN, TP and Chl.a concentrations were projected to be approximately 21%, 19%, 25%, and 65%, respectively. Fourth, changes in seasonal variation due to climate change may lead to an enhanced ecological risk of algal blooms. Finally, the effect of reducing TN and TP concentrations by proposed water infrastructure development was found to be significantly weakened (nearly 40% and 20% for TN and TP, respectively, under a mild climate change scenario), while the negative effect (i.e., increase in the Chl.a concentration) was notably accelerated. Regional cooperation is critical for protecting the water quality of the bay, particularly under climate change. The insights obtained in this study are applicable to other coastal water zones around the world with similar socioeconomic backgrounds and climatic conditions.


Assuntos
Mudança Climática , Qualidade da Água , Clorofila A/análise , Rios/química , Monitoramento Ambiental/métodos , Clorofila , Eutrofização , Fósforo/análise , Nitrogênio/análise , China
8.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 54(3): 602-607, 2023 May.
Artigo em Zh | MEDLINE | ID: mdl-37248591

RESUMO

Objective: To analyze the detection rate, in vitro susceptibility to antibiotics, and carbapenemase types of carbapenem-resistant Enterobacteriaceae (CRE) strains in the clinical samples of a hospital and to provide support for the prevention, control and treatment of CRE-related infections. Methods: Clinical specimens were examined according to the operating procedures of bacteriological tests. Species identification and in vitro drug susceptibility testing were performed on the isolated strains. Carbapenemase inhibitor enhancement testing, which combined the use of 3-aminobenzeneboronic acid and ethylenediaminetetraacetic acid, was conducted to identify the types of carbapenemase in the CRE strains. Results: In 2021, 2215 CRE strains were isolated from 157196 clinical samples collected in this hospital, presenting a detection rate of 1.4% (2215/157196). A total of 1134 non-repetitive strains of CRE were isolated from 903 patients. The main sources of samples were respiratory tract (494/1134, 43.6%), secretion (191/1134, 16.8%) and blood (173/1134, 15.3%) samples. The cases with the same CRE strain isolated from the samples of two, three and four sites accounted for 12.5%, 4.9%, and 1.1%, respectively. The most common species was Klebsiella pneumoniae (883/1134, 77.9%), followed by Enterobacter cloacae complex (107/1134, 9.4%) and Escherichia coli (96/1134, 8.5%). The rates of resistance to polymyxin B and tigecycline of different species of CRE strains were not significantly different ( P<0.05). Serine carbapenemase-producing strains, metallo-ß-lactamase-producing strains, and those producing both enzymes accounted for 82.6% (809/979), 17.2% (168/979), and 0.2% (2/979), respectively. Conclusion: CRE strains are frequently isolated from samples collected from the respiratory tract, secretion, and blood. The most common strain is serine carbapenemase-producing K. pneumoniae, which has a high resistance rate to various antimicrobial drugs, and risk factors of its associated infections deserve more attention.


Assuntos
Enterobacteriáceas Resistentes a Carbapenêmicos , Infecções por Enterobacteriaceae , Mycobacterium tuberculosis , Humanos , Infecções por Enterobacteriaceae/epidemiologia , Infecções por Enterobacteriaceae/tratamento farmacológico , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Proteínas de Bactérias , beta-Lactamases , Klebsiella pneumoniae , Escherichia coli , Hospitais
9.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 54(3): 667-672, 2023 May.
Artigo em Zh | MEDLINE | ID: mdl-37248603

RESUMO

Objective: To compare the consistency and accuracy of a rapid test method and a traditional test method for pathogen identification, antimicrobial susceptibility and carbapenemase type identification of positive blood culture samples. Methods: A total of 51 positive blood culture samples of bloodstream infection (BSI) were collected between March 2022 and May 2022. All samples were found to be "positive for Gram-negative bacilli" according to the blood smear results. The rapid method was adopted to perform rapid antimicrobial susceptibility test (RAST) and analysis of the positive blood culture samples. According to the RAST result interpretation standards, NG-Test® CARBA 5 was used for rapid carbapenemase detection of the imipenem-resistant strains and the results were confirmed by PCR. In addition, mass spectrometry, VITEK 2 Compact drug sensitivity analysis, and carbapenemase type identification were performed with the colonies cultured with positive samples according to the traditional method. Results: In the identification of bacteria, the rapid method and the traditional method had 100% consistency rate in the identification results of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii. In the antimicrobial susceptibility test, the consistency rate between the results of the two methods was high and the consistency rate for results for susceptibility to imipenem was 100%. In the identification of carbapenemase type, 18 serinase-producing strains and 3 metal-ß-lactamase-producing strains of Enterobacterales were detected by the traditional method. With the rapid method, 18 Klebsiella pneumoniae carbapenemase (KPC)-producing strains, 2 New Delhi metallo-betalactamase (NDM)-producing strains, and 1 imipenem enzyme (IMP)-producing strain were identified in the blood culture samples by using a testing kit. Compared with the PCR results, the sensitivity and specificity of the rapid test for determining carbapenemase types were 100%. In this study, we investigated a rapid method for bacteria and carbapenemase type identification of positive blood culture specimens and found that the turnaround time (TAT) of the rapid method was reduced by 1.94 days on average in comparison with the TAT of the traditional method. Conclusion: The rapid method established in the study can effectively shorten the TAT for pathogenic microorganism identification and antimicrobial susceptibility test of blood culture samples, and the joint report of colloidal gold carbapenemase type identification results can provide a reference for clinicians to use antibiotics appropriately and accurately manage multi-drug resistant bacterial infections.


Assuntos
Carbapenêmicos , Sepse , Humanos , Carbapenêmicos/farmacologia , beta-Lactamases , Proteínas de Bactérias/genética , Antibacterianos/farmacologia , Imipenem/farmacologia , Klebsiella pneumoniae , Escherichia coli , Testes de Sensibilidade Microbiana
10.
Med Mycol ; 60(4)2022 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-35362524

RESUMO

Cryptococcus is an opportunistic pathogenic fungus and is the major cause of fungal meningitis. The cryptococcal antigen (CrAg) lateral flow assay (LFA) is an immunochromatographic test system that has simplified diagnosis as a point-of-care test. In this study, we evaluated the diagnostic performance of Cryptococcal capsular polysaccharide detection FungiXpert (Genobio Pharmaceutical, Tianjin, China) using serum and cerebrospinal fluid (CSF) samples for the diagnosis of cryptococcosis and investigated the cross-reaction of the assays to pathogenic fungi and bacterium by comparing it to the U.S. Food and Drug Administration (US FDA)-approved IMMY CrAg LFA. Eighty CSF and 119 serum/plasma samples from 158 patients were retrospectively collected to test for qualitative or semi-quantitative detection of CrAg. Cross-reaction of the assays was tested using 28 fungi and 1 bacterium. Compared to IMMY CrAg LFA, the FungiXpert LFA demonstrated 99.1% sensitivity and 98.9% specificity in the qualitative test. In the 96 semi-quantitative CrAg assay results, 39 (40.6%) test titers of FungiXpert LFA were 1-2 dilutions higher than those of IMMY CrAg LFA. The Intraclass Correlation Coefficient of the Semi-quantitative results of CrAg titer tests via the two assays was 0.976. Similar to IMMY CrAg LFA, FungiXpert LFA showed cross-reactivity with Trichosporon asahii. Compared with the IMMY CrAg LFA, the FungiXpert LFA showed an equal, yet, excellent performance. However, it is important to note that these two assays have potential cross-reactivity to T. asahii when diagnosing patients. FungiXpert LFA is a rapid screening method for the effective and practical diagnosis and treatment of cryptococcosis. LAY SUMMARY: The FungiXpert LFA was developed to diagnose fungal meningitis caused by Cryptococcus yeasts, by using serum or cerebrospinal fluid. It was compared to an existing lateral flow assay (LFA). The FungiXpert LFA performed well in qualitative and semi-quantitative tests.


Assuntos
Criptococose , Cryptococcus , Infecções por HIV , Meningite Criptocócica , Meningite Fúngica , Animais , Antígenos de Fungos , Criptococose/diagnóstico , Criptococose/veterinária , Infecções por HIV/veterinária , Meningite Criptocócica/diagnóstico , Meningite Criptocócica/veterinária , Meningite Fúngica/veterinária , Polissacarídeos , Estudos Retrospectivos
11.
BMC Biol ; 19(1): 95, 2021 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-33957926

RESUMO

BACKGROUND: Target of Rapamycin Complex 1 (TORC1) is a highly conserved eukaryotic protein complex that couples the presence of growth factors and nutrients in the environment with cellular proliferation. TORC1 is primarily implicated in linking amino acid levels with cellular growth in yeast and mammals. Although glucose deprivation has been shown to cause TORC1 inactivation in yeast, the precise role of TORC1 in glucose signaling and the underlying mechanisms remain unclear. RESULTS: We demonstrate that the presence of glucose in the growth medium is both necessary and sufficient for TORC1 activation. TORC1 activity increases upon addition of glucose to yeast cells growing in a non-fermentable carbon source. Conversely, shifting yeast cells from glucose to a non-fermentable carbon source reduces TORC1 activity. Analysis of transcriptomic data revealed that glucose and TORC1 co-regulate about 27% (1668/6004) of yeast genes. We demonstrate that TORC1 orchestrates the expression of glucose-responsive genes mainly via the Tap42-Sit4-Rrd1/2 pathway. To confirm TORC1's function in glucose signaling, we tested its role in spore germination, a glucose-dependent developmental state transition in yeast. TORC1 regulates the glucose-responsive genes during spore germination and inhibition of TORC1 blocks spore germination. CONCLUSIONS: Our studies indicate that a regulatory loop that involves activation of TORC1 by glucose and regulation of glucose-responsive genes by TORC1, mediates nutritional control of growth and development in yeast.


Assuntos
Saccharomyces cerevisiae , Proteínas Adaptadoras de Transdução de Sinal , Carbono , Glucose , Peptídeos e Proteínas de Sinalização Intracelular , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Peptidilprolil Isomerase , Proteína Fosfatase 2/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
12.
Phytother Res ; 35(4): 1991-2004, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33166007

RESUMO

Neuroinflammation is an inflammatory response in the nervous system that is associated with various neurological diseases including Alzheimer's diseases and others. Many studies evaluated the anti-inflammatory potential of Santalum album (S. album) extract, but none of them analyzed its effects against neuroinflammatory response in vitro. In addition, the precise mechanism underlying the anti-inflammatory effect of the extract has not yet been elucidated. Therefore, in this study, we investigated the effect of S. album extract on modulation of toll-like receptor 3 (TLR3) agonist polyinosnic-polycytidylic acid (PolyI:C)-induced neuroinflammatory response in human neuroblastoma cells. The TLR3-mediated immune response was differentially modulated by S. album extract in SH-SY5Y cells. In addition, treatment of cells with the conditioned medium (CM) of S. album extract significantly increased the mRNA levels of IFN-ß, IFN-α, MxA and OAS-1 and decreased IL-6, CXCL8, CCL2 and IP-10. S. album extract has indirectly affected the expression of IFNs and inflammatory cytokines in SH-SY5Y cells. Furthermore, the extract was able to modulate PolyI:C-induced inflammatory response in Caco2 cells. Overall, S. album was capable to attenuate PolyI:C-induced neuroinflammatory effect through the induction of TLR2, TLR4 and the modulation of TLR negative regulators of the TRAF3, IRF3 and NF-κB pathways.


Assuntos
Anti-Inflamatórios/uso terapêutico , Fármacos Neuroprotetores/uso terapêutico , Extratos Vegetais/química , Santalum/química , Receptor 3 Toll-Like/metabolismo , Anti-Inflamatórios/farmacologia , Humanos , Fármacos Neuroprotetores/farmacologia
13.
Biol Pharm Bull ; 43(3): 409-417, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31875578

RESUMO

Forest bathing is suggested to have beneficial effects on various aspects of human health. Terpenes, isoprene based-phytochemicals emitted from trees, are largely responsible for these beneficial effects of forest bathing. Although the therapeutic effects of terpenes on various diseases have been revealed, their effects on neuronal health have not yet been studied in detail. Here, we screened 16 terpenes that are the main components of Korean forests using Drosophila Alzheimer's disease (AD) models to identify which terpenes have neuroprotective effects. Six out of the 16 terpenes, ρ-cymene, limonene (+), limonene (-), linalool, α-pinene (+), and ß-pinene (-), partially suppressed the beta amyloid 42 (Aß42)-induced rough eye phenotype when fed to Aß42-expressing flies. Among them, limonene (+) restored the decreased survival of flies expressing Aß42 in neurons during development. Limonene (+) treatment did not affect Aß42 accumulation and aggregation, but did cause to decrease cell death, reactive oxygen species levels, extracellular signal-regulated kinase phosphorylation, and inflammation in the brains or the eye imaginal discs of Aß42-expressing flies. This neuroprotective effect of limonene (+) was not associated with autophagic activity. Our results suggest that limonene (+) has a neuroprotective function against the neurotoxicity of Aß42 and, thus, is a possible therapeutic reagent for AD.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Limoneno/farmacologia , Fármacos Neuroprotetores/farmacologia , Terpenos/farmacologia , Peptídeos beta-Amiloides/toxicidade , Animais , Animais Geneticamente Modificados , Autofagia/efeitos dos fármacos , Encéfalo/metabolismo , Modelos Animais de Doenças , Drosophila melanogaster , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Neuroglia/efeitos dos fármacos , Fragmentos de Peptídeos/toxicidade , Fosforilação/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Sobrevida
14.
Sensors (Basel) ; 20(20)2020 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-33096841

RESUMO

The radiation intensity of observed auroras in the far-ultraviolet (FUV) band varies dramatically with location for aerospace applications, requiring a photon counting imaging apparatus with a wide dynamic range. However, combining high spatial resolution imaging with high event rates is technically challenging. We developed an FUV photon counting imaging system for aurora observation. Our system mainly consists of a microchannel plate (MCP) stack readout using a wedge strip anode (WSA) with charge induction and high-speed electronics, such as a charge sensitive amplifier (CSA) and pulse shaper. Moreover, we constructed an anode readout model and a time response model for readout circuits to investigate the counting error in high counting rate applications. This system supports global rates of 500 kilo counts, 0.610 dark counts s-1 cm-2 at an ambient temperature of 300 K and 111 µm spatial resolution at 400 kilo counts s-1 (kcps). We demonstrate an obvious photon count loss at incident intensities close to the counting capacity of the system. To preserve image quality, the response time should be improved and some noise performance may be sacrificed. Finally, we also describe the correlation between counting rate and imaging resolution, which further guides the design of space observation instruments.

15.
Chemistry ; 25(49): 11432-11436, 2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31309625

RESUMO

We present strategies to tune the redox properties of polyoxometalate clusters to enhance the electron-coupled proton-buffer-mediated water splitting process, in which the evolution of hydrogen and oxygen can occur in different forms and is separated in time and space. By substituting the heteroatom template in the Keggin-type polyoxometalate cluster, H6 ZnW12 O40 , it is possible to double the number of electrons and protonation in the redox reactions (from two to four). This increase can be achieved with better matching of the energy levels as indicated by the redox potentials, compared to the ones of well-studied H3 PW12 O40 and H4 SiW12 O40 . This means that H6 ZnW12 O40 can act as a high-performance redox mediator in an electrolytic cell for the on-demand generation of hydrogen with a high decoupling efficiency of 95.5 % and an electrochemical energy efficiency of 83.3 %. Furthermore, the H6 ZnW12 O40 cluster also exhibits an excellent cycling behaviour and redox reversibility with almost 100 % H2 -mediated capacity retention during 200 cycles and a high coulombic efficiency >92 % each cycle at 30 mA cm-2 .

16.
Biol Pharm Bull ; 42(9): 1471-1481, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31474708

RESUMO

Sutaehwan (STH) has been used in Korean medicine for the treatment of abortus habitualis such as fetal restlessness in the uterus. Previously, we reported that a modified formulation of STH, Sutaehwan-Gami, has phytoestrogen-like properties in an ovariectomized menopausal rat model. However, the therapeutic effects of STH and the precise mechanisms by which STH affects various menopausal symptoms remain poorly understood. The current study was designed to explore the effects of a modified form of STH on menopausal anxiety, depression and heart hypertrophy and its mechanisms in 4-vinylcyclohexene diepoxide (VCD)-induced menopausal mouse models. VCD-induced menopausal model mice were fed a modified form of STH, which contained water extract of 3 herbs (called STH_KP17001) at a dose of 100 or 300 mg/kg/d or as a positive control, estradiol at a dose of 0.2 mg/kg/d with standard mouse pellets for 13 weeks. The results show that STH_KP17001 significantly restored the VCD-induced weight reduction of uterine and ovary through the phosphorylation of extracellular signal-regulated kinase (ERK) and protein kinase B (AKT) in the uterus and ovary. Moreover, STH_KP17001 showed slight proliferative effects and estrogen receptor α phosphorylation in MCF-7 cells. Treatment with STH_KP17001 reversed VCD-induced anxiety and depression through AMP-activated protein kinase (AMPK) activation and brain-derived neurotrophic factor (BDNF) expression in the cerebral cortex, while improving heart hypertrophy through inactivation of inhibitor of kappaB α (IκBα) in the heart. The results indicate that STH_KP17001 improves menopause-induced anxiety, depression and heart hypertrophy, implying its protective role for the management of menopausal symptoms.


Assuntos
Ansiedade/prevenção & controle , Cardiomegalia/prevenção & controle , Depressão/prevenção & controle , Menopausa/psicologia , Extratos Vegetais/farmacologia , Animais , Cicloexenos , Modelos Animais de Doenças , Feminino , Humanos , Células MCF-7 , Medicina Tradicional Coreana , Camundongos Endogâmicos C57BL , Extratos Vegetais/isolamento & purificação , Compostos de Vinila
17.
Angew Chem Int Ed Engl ; 58(10): 3092-3096, 2019 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-30589160

RESUMO

Lithium metal anodes suffer from poor cycling stability and potential safety hazards. To alleviate these problems, Li thin-film anodes prepared on current collectors (CCs) and Li-free types of anodes that involve direct Li plating on CCs have received increasing attention. In this study, the atomic-scale design of Cu-CC surface lithiophilicity based on surface lattice matching of the bcc Li(110) and fcc Cu(100) faces as well as electrochemical achievement of Cu(100)-preferred surfaces for smooth Li deposition with a low nucleation barrier is reported. Additionally, a purposely designed solid-electrolyte interphase is created for Li anodes prepared on CCs. Not only is a smooth planar Li thin film prepared, but a uniform Li plating/stripping on the skeleton of 3D CCs is achieved as well by high utilization of the surface and cavities of the 3D CCs. This work demonstrates surface electrochemistry approaches to construct stable Li metal-electrolyte interphases towards practical applications of Li anodes prepared on CCs.

18.
J Am Chem Soc ; 140(8): 3134-3138, 2018 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-29425034

RESUMO

Investigations of the Ag (I)-substituted Keggin K3[H3AgIPW11O39] as a bifunctional Lewis acidic and basic catalyst are reported that explore the stabilization of Li2Sn moieties so that reversible redox reactions in S-based electrodes would be possible. Spectroscopic investigations showed that the Li2Sn-moieties can be strongly adsorbed on the {AgIPW11O39} cluster, where the Ag(I) ion can act as a Lewis acid site to further enhance the adsorption of the S-moieties, and these interactions were investigated and rationalized using DFT. These results were used to construct an electrode for use in a Li-S battery with a very high S utilization of 94%, and a coulometric capacity of 1580 mAh g-1. This means, as a result of using the AgPOM, both a high active S content, as well as a high areal S mass loading, is achieved in the composite electrode giving a highly stable battery with cycling performance at high rates (1050 and 810 mAh g-1 at 1C and 2C over 100 to 300 cycles, respectively).

19.
Chemistry ; 24(33): 8275-8280, 2018 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-29694691

RESUMO

Inspired by the metal active sites of [NiFeSe]-hydrogenases, a dppf-supported nickel(II) selenolate complex (dppf=1,1'-bis(diphenylphosphino)ferrocene) shows high catalytic activity for electrochemical proton reduction with a remarkable enzyme-like H2 evolution turnover frequency (TOF) of 7838 s-1 under an Ar atmosphere, which markedly surpasses the activity of a dppf-supported nickel(II) thiolate analogue with a low TOF of 600 s-1 . A combined study of electrochemical experiments and DFT calculations shed light on the catalytic process, suggesting that selenium atom as a bio-inspired proton relay plays a key role in proton exchange and enhancing catalytic activity of H2 production. For the first time, this type of Ni selenolate-containing electrocatalyst displays a high degree of O2 and H2 tolerance. Our results should encourage the development of the design of highly efficient oxygen-tolerant Ni selenolate molecular catalysts.

20.
Biol Pharm Bull ; 41(4): 470-477, 2018 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-29398668

RESUMO

The Nardostachys jatamansi DC (NJ) root has been used as a sedative or analgesic to treat neurological symptoms and pain in traditional Korean medicine. Here, we investigate the potential effects of NJ on Alzheimer's disease (AD) and reveal the molecular mechanism through which NJ exerts its effects. The neuroprotective effect of the NJ root ethanol extract against ß amyloid (Aß) toxicity was examined in vitro using a cell culture system and in vivo using a Drosophila AD model. The NJ extract and chlorogenic acid, a major component of NJ, inhibited Aß-induced cell death in SH-SY5Y cells. Moreover, the NJ extract rescued the neurological phenotypes of the Aß42-expressing flies (decreased survival and pupariation rate and a locomotor defect) and suppressed Aß42-induced cell death in the brain. We also found that NJ extract intake reduced glial cell number, reactive oxygen species level, extracellular-signal-regulated kinase (ERK) phosphorylation, and nitric oxide level in Aß42-expressing flies, without affecting Aß accumulation. These data suggest that the neuroprotective activity of NJ might be associated with its antioxidant and anti-inflammatory properties, as well as its inhibitory action against ERK signaling; thus, NJ is a promising medicinal plant for the development of AD treatment.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Encéfalo/efeitos dos fármacos , Nardostachys/química , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/uso terapêutico , Extratos Vegetais/uso terapêutico , Raízes de Plantas/química , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/antagonistas & inibidores , Peptídeos beta-Amiloides/genética , Peptídeos beta-Amiloides/metabolismo , Animais , Animais Geneticamente Modificados , Encéfalo/metabolismo , Encéfalo/patologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Drosophila/genética , Drosophila/crescimento & desenvolvimento , Etnofarmacologia , Humanos , Larva/efeitos dos fármacos , Larva/metabolismo , Medicina Tradicional Coreana , Proteínas do Tecido Nervoso , Neurônios/metabolismo , Neurônios/patologia , Fármacos Neuroprotetores/farmacologia , Fragmentos de Peptídeos/antagonistas & inibidores , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Fitoterapia , Extratos Vegetais/farmacologia , República da Coreia , Análise de Sobrevida
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