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1.
BMC Public Health ; 24(1): 1152, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38658890

RESUMO

One Stop Crisis Center (OSCC) is a multi-sectorial center aimed to provide medical, social, legal, police and shelter services to survivors of domestic violence, rape, sexual assault, sodomy and child abuse. Although OSCCs have been established for almost three decades in different parts of the world including in Malaysia, there is a lack of a validated instrument to measure the service quality rendered in OSCCs. A validated instrument known as OSCC-Qual was developed using a 5-stage approach where (1) in stage 1, group discussions were conducted among all authors to identify potential items for the instrument; (2) in stage 2, content validation was performed by 13 experts using content validity index and modified kappa; (3) in stage 3, exploratory factor analysis was performed by 141 healthcare staff with experience in managing OSCC cases to validate the items as well as to identify the number of factors in the instrument; (4) in stage 4, confirmatory factor analysis was performed by 110 domestic violence survivors to ascertain the validity of the factors and items retained in stage 3 and (5) in stage 5, forward and backward translation into local Malay and Chinese languages was performed. Results: In stage 1, a total of 42 items were identified. No item was deleted in stage 2. In stage 3, a total of 7 factors (i.e., "information provision", "competency of staff", "professionalism", "supportive environment", "attitude of staff", "multi-sectorial coordination" and "tangibles") were identified. Four items were deleted due to poor factor loading. In stage 4, another 3 items were iteratively removed due to poor factor loading. Discriminant validity was good. Conclusion: With the availability of the 7-factor and 35-item OSCC-Qual instrument, it is hoped that the efficiency of OSCC in achieving its philosophical objectives after three decades of implementation can be unraveled and remedial actions can be taken, if necessary.


Assuntos
Violência Doméstica , Humanos , Malásia , Feminino , Adulto , Masculino , Inquéritos e Questionários , Análise Fatorial , Reprodutibilidade dos Testes , Qualidade da Assistência à Saúde
2.
Mar Drugs ; 22(2)2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38393066

RESUMO

The balance between bone-resorbing osteoclasts and bone-forming osteoblasts is essential for the process of bone remodeling. Excessive osteoclast differentiation plays a pivotal role in the pathogenesis of bone diseases such as rheumatoid arthritis and osteoporosis. In the present study, we examined whether 7,8-epoxy-11-sinulariolide acetate (Esa), a marine natural product present in soft coral Sinularia siaesensis, attenuates inflammation and osteoclastogenesis in vitro. The results indicated that Esa significantly inhibited lipopolysaccharide (LPS)-induced inflammation model of RAW264.7 cells and suppressed receptor activator for nuclear factor-κB ligand (RANKL)-triggered osteoclastogenesis. Esa significantly down-regulated the protein expression of iNOS, COX-2, and TNF-α by inhibiting the NF-κB/MAPK/PI3K pathways and reducing the release of reactive oxygen species (ROS) in RAW264.7 macrophages. Besides, Esa treatment significantly inhibited osteoclast differentiation and suppressed the expression of osteoclast-specific markers such as NFATC1, MMP-9, and CTSK proteins. These findings suggest that Esa may be a potential agent for the maintenance of bone homeostasis associated with inflammation.


Assuntos
Antozoários , Reabsorção Óssea , Diterpenos , Animais , Osteogênese , Fosfatidilinositol 3-Quinases/metabolismo , Diferenciação Celular , Osteoclastos , NF-kappa B/metabolismo , Inflamação/metabolismo , Antozoários/metabolismo , Ligante RANK/metabolismo , Fatores de Transcrição NFATC/metabolismo
3.
Nano Lett ; 23(22): 10274-10281, 2023 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-37909311

RESUMO

Recently, orbital Hall current has attracted attention as an alternative method to switch the magnetization of ferromagnets. Here we present our findings on electrical switching of the antiferromagnetic state in Mn3Sn/Cr, where despite the much smaller spin Hall angle of Cr, the switching current density is comparable to heavy metal-based heterostructures. However, the inverse process, i.e., spin-to-charge conversion in Cr-based heterostructures, is much less efficient than the Pt-based equivalents, as manifested in the 1 order of magnitude smaller terahertz emission intensity and spin current-induced magnetoresistance. These results in combination with the slow decay of terahertz emission against Cr thickness (diffusion length of ∼11 nm) suggest that the observed magnetic switching can be attributed to orbital current generation in Cr, followed by efficient conversion to spin current. Our work demonstrates the potential of light metals like Cr as efficient orbital/spin current sources for antiferromagnetic spintronics.

4.
Angew Chem Int Ed Engl ; 63(9): e202317514, 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38179807

RESUMO

In this study, we highlight the impact of catalyst geometry on the formation of O-O bonds in Cu2 and Fe2 catalysts. A series of Cu2 complexes with diverse linkers are designed as electrocatalysts for water oxidation. Interestingly, the catalytic performance of these Cu2 complexes is enhanced as their molecular skeletons become more rigid, which contrasts with the behavior observed in our previous investigation with Fe2 analogs. Moreover, mechanistic studies reveal that the reactivity of the bridging O atom results in distinct pathways for O-O bond formation in Cu2 and Fe2 catalysts. In Cu2 systems, the coupling takes place between a terminal CuIII -OH and a bridging µ-O⋅ radical. Whereas in Fe2 systems, it involves the coupling of two terminal Fe-oxo entities. Furthermore, an in-depth structure-activity analysis uncovers the spatial geometric prerequisites for the coupling of the terminal OH with the bridging µ-O⋅ radical, ultimately leading to the O-O bond formation. Overall, this study emphasizes the critical role of precisely adjusting the spatial geometry of catalysts to align with the O-O bonding pathway.

5.
Angew Chem Int Ed Engl ; : e202409713, 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39031452

RESUMO

The introduction of precise pore defects into nanocarbon structures results in the emergence of distinct physicochemical characteristics. However, there is a lack of research on non-planar chiral nanographene involving precise pore defects. Herein, we have developed two analogues to the π-extended pentadecabenzo[9]helicene (EP9H) containing embedded pore defects. Each molecule, namely extended dodecabenzo[7]helicene (ED7H; 1) or extended nonabenzo[5]helicene (EN5H; 2), exhibits dual-state emission. Significantly, the value of |glum| of 1 is exceptionally high at 1.41 × 10-2 in solution and BCPL as 254 M-1 cm-1. In PMMA film, |glum| of 1 is 8.56 × 10-3, and in powder film, it is 5.00 × 10-3. This study demonstrates that nanocarbon molecules with pore defects exhibit dual-state emission properties while maintaining quite good chiral luminescence properties. It was distinguished from the aggregation-caused quenching (ACQ) effect corresponding to the nanocarbon without embedded defect. Incorporating pore defects into chiral nanocarbon molecules also simplifies the synthesis process and enhances the solubility of the resulting product. These findings suggest that the introduction of pore defects can be a viable approach to improve nanocarbon molecules.

6.
Immunology ; 168(4): 654-670, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36314527

RESUMO

The prognosis of systemic lupus erythematosus (SLE) is unpredictable. This study aimed to examine the regulatory mechanism of the AHR/TET2/NT5E pathway during SLE progression. The AHR, TET2 and NT5E expression levels were examined in T regulatory cells (Tregs) of patients with SLE. The correlation of AHR, TET2 or NT5E expression levels with the immunosuppressive functions of Tregs was analysed. In patients with SLE, the number of CD4+ IL2RA- FOXP3+ T cell subset was positively correlated with the SLE disease activity index value and negatively correlated with the AHR and TET2 expression levels in CD4+ IL2RA+ FOXP3+ Tregs. Transcriptional profiles of 79 patients with SLE obtained from the Gene Expression Omnibus database (GSE61635 dataset) revealed a significant positive correlation between the mRNA expression levels of AHR and TET2. In silico analysis predicted that the TET2 promoter comprises an AHR-binding site. Kynurenine (KYN) promoted the binding of AHR to the TET2 promoter in Tregs of patients with SLE and Jurkat T cell lines. Furthermore, NT5E expression was significantly downregulated in Tregs of patients with SLE, which can be attributed to the dysregulation of NT5E promoter methylation status induced by downregulated TET2 activity. Furthermore, the Treg immunosuppressive activity, which is mediated through the TET2 and A2AR-adenosine pathways, in the KYN-treated group was approximately two-fold higher than that in the control group. The AHR/TET2/NT5E axis mediates the Treg immunosuppressive activity. These findings provide novel insights for the development of therapeutic approaches for SLE and related autoimmune diseases.


Assuntos
Dioxigenases , Lúpus Eritematoso Sistêmico , Humanos , 5'-Nucleotidase/genética , 5'-Nucleotidase/metabolismo , Dioxigenases/genética , Dioxigenases/metabolismo , Proteínas de Ligação a DNA/metabolismo , Regulação para Baixo , Fatores de Transcrição Forkhead/metabolismo , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/metabolismo , Subpopulações de Linfócitos T , Linfócitos T Reguladores
7.
Phys Rev Lett ; 131(10): 103002, 2023 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-37739370

RESUMO

We investigate the 2^{3}S_{1}-2^{3}P_{J} (J=0, 1, 2) transitions in ^{6}Li^{+} using the optical Ramsey technique and achieve the most precise values of the hyperfine splittings of the 2^{3}S_{1} and 2^{3}P_{J} states, with smallest uncertainty of about 10 kHz. The present results reduce the uncertainties of previous experiments by a factor of 5 for the 2^{3}S_{1} state and a factor of 50 for the 2^{3}P_{J} states, and are in better agreement with theoretical values. Combining our measured hyperfine intervals of the 2^{3}S_{1} state with the latest quantum electrodynamic (QED) calculations, the improved Zemach radius of the ^{6}Li nucleus is determined to be 2.44(2) fm, with the uncertainty entirely due to the uncalculated QED effects of order mα^{7}. The result is in sharp disagreement with the value 3.71(16) fm determined from simple models of the nuclear charge and magnetization distribution. We call for a more definitive nuclear physics value of the ^{6}Li Zemach radius.

8.
Exp Aging Res ; 49(3): 214-225, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35792710

RESUMO

BACKGROUND: It has been reported that LXR agonist can inhibit Aß generation and alleviate Aß-induced various adverse reactions in vivo and in vitro experiments, but the mechanisms have not been clarified. The study aimed to observe the effect of LXR agonist TO901317 on the cognitive function of AD transgenic mice fed with cholesterol-rich diet (CRD), and to explore the possible mechanism. Methods: 32 male 6-month-old double transgenic AD mice were enrolled and randomly divided into 4 groups: control (normal diet) group, CRD treatment group, TO901317 treatment group and GSK2033 treatment group. After 3 month, Morris water maze was for the changes of spatial exploration and memory ability; ELISA was for detecting the production of Aß42 in the brain; the concentration of total cholesterol (TC), low density lipoprotein (LDL) and high density lipoprotein (HDL) in serum were detected by cholesterol enzyme colorimetry; Finally, the expression of LXR-ß, RXR-α, ABCA1, caveolin-1, BACE1 and APP at protein level in the brains was measured by Western blotting. RESULTS: Compared with the control group, the learning, memory ability and spatial exploration ability of the mice were more significantly serious in the CRD group (P<0.05); The contents of TC and LDL in the serum and the production of Aß42 in the brains were significantly increased (P<0.05), but HDL was remarkably decreased (P<0.05); The protein levels of LXR-ß, RXR-α and ABCA1 were also significantly decreased (P<0.05); The expression of caveolin-1, APP and BACE1 were evidently increased (P<0.05). However, after treatment with TO901317, the impaired learning and memory and spatial exploration ability of the mice were significantly improved (P<0.05); The contents of TC and LDL in serum and the production of Aß42 in the brains were significantly decreased (P<0.05), but HLD was increased (P<0.05); The protein levels of LXR-ß, RXR-α, ABCA1were all significantly increased (P<0.05), while, the expression of caveolin-1, APP and BACE1 were all significantly decreased (P<0.05). All the changes were reversed by GSK2033 (P<0.05). CONCLUSIONS: TO901317 attenuated the more serious impairment of spatial exploration, learning and memory in transgenic AD mice induced by CRD, and the mechanism may be that TO901317 could activate the LXR-ß/RXR-α/ABCA1 transmembrane transport system, promote the cholesterol efflux, and decreased caveolin-1, APP and BACE1, further reduce Aß42 in the brains.


Assuntos
Secretases da Proteína Precursora do Amiloide , Receptores Nucleares Órfãos , Animais , Humanos , Masculino , Camundongos , Envelhecimento , Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Transportador 1 de Cassete de Ligação de ATP , Caveolina 1/metabolismo , Colesterol , Cognição , Dieta , Receptores X do Fígado/metabolismo , Microdomínios da Membrana/metabolismo , Camundongos Transgênicos , Receptores Nucleares Órfãos/metabolismo , Transporte Proteico , Receptor X Retinoide alfa/metabolismo
9.
Molecules ; 28(19)2023 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-37836735

RESUMO

Three new cembranoids (1-3) and a new casbanoid (4), along with three known analogues (5-7), have been isolated from the soft coral Sinularia nanolobata collected off Ximao Island. The structures, including the absolute configurations of new compounds, were established using extensive spectroscopic data analysis, time-dependent density functional theory/electronic circular dichroism (TDDFT-ECD) calculations, and the comparison with spectroscopic data of known compounds. In the in vitro bioassay, compounds 1 and 5 exhibited moderate cytotoxic activities against human erythroleukemia (HEL) cell lines, with IC50 values of 37.1 and 42.4 µM, respectively.


Assuntos
Antozoários , Diterpenos , Animais , Humanos , Estrutura Molecular , Antozoários/química , Linhagem Celular Tumoral , Diterpenos/farmacologia , Diterpenos/química , China
10.
Plant Physiol ; 186(4): 2064-2077, 2021 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-34618109

RESUMO

Sugar is considered as the primary regulator of plant apical dominance, whereby the outgrowth of axillary buds is inhibited by the shoot tip. However, there are some deficiencies in this theory. Here, we reveal that Fatty Acid Export 6 (BnFAX6) functions in FA transport, and linoleic acid or its derivatives acts as a signaling molecule in regulating apical dominance of Brassica napus. BnFAX6 is responsible for mediating FA export from plastids. Overexpression of BnFAX6 in B. napus heightened the expression of genes involved in glycolysis and lipid biosynthesis, promoting the flow of photosynthetic products to the biosynthesis of FAs (including linoleic acid and its derivatives). Enhancing expression of BnFAX6 increased oil content in seeds and leaves and resulted in semi-dwarf and increased branching phenotypes with more siliques, contributing to increased yield per plant relative to wild-type. Furthermore, decapitation led to the rapid flow of the carbon from photosynthetic products to FA biosynthesis in axillary buds, consistent with the overexpression of BnFAX6 in B. napus. In addition, free FAs, especially linoleic acid, were rapidly transported from leaves to axillary buds. Increasing linoleic acid in axillary buds repressed expression of a key transcriptional regulator responsible for maintaining bud dormancy, resulting in bud outgrowth. Taken together, we uncovered that BnFAX6 mediating FA export from plastids functions in lipid biosynthesis and in axillary bud dormancy release, possibly through enhancing linoleic acid level in axillary buds of B. napus.


Assuntos
Brassica napus/genética , Ácidos Graxos/biossíntese , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/genética , Brassica napus/crescimento & desenvolvimento , Brassica napus/metabolismo , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo
11.
Opt Lett ; 47(5): 1041-1044, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35230285

RESUMO

This paper numerically investigates the evolution of solitons in an optical lattice with gradual longitudinal manipulation. We find that the stationary solutions (with added noise to the amplitude) keep their width, profile, and intensity very well, although the propagation path is continuously changing during the modulated propagation. Discontinuities in the modulation functions cause the scattering of the beam that may end the stable propagation. Our results reveal a method to control the trajectory of solitons by designed variation of the optical lattice waveguides. Interesting examples presented include the snakelike and spiraling solitons that both can be adaptively induced in sinusoidally and helically shaped optical lattices. The controlled propagation paths provide an excellent opportunity for various applications, including optical switches and signal transmission, among others.

12.
Acta Math Sin Engl Ser ; 38(10): 1901-1938, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36407804

RESUMO

With the great advancement of experimental tools, a tremendous amount of biomolecular data has been generated and accumulated in various databases. The high dimensionality, structural complexity, the nonlinearity, and entanglements of biomolecular data, ranging from DNA knots, RNA secondary structures, protein folding configurations, chromosomes, DNA origami, molecular assembly, to others at the macromolecular level, pose a severe challenge in their analysis and characterization. In the past few decades, mathematical concepts, models, algorithms, and tools from algebraic topology, combinatorial topology, computational topology, and topological data analysis, have demonstrated great power and begun to play an essential role in tackling the biomolecular data challenge. In this work, we introduce biomolecular topology, which concerns the topological problems and models originated from the biomolecular systems. More specifically, the biomolecular topology encompasses topological structures, properties and relations that are emerged from biomolecular structures, dynamics, interactions, and functions. We discuss the various types of biomolecular topology from structures (of proteins, DNAs, and RNAs), protein folding, and protein assembly. A brief discussion of databanks (and databases), theoretical models, and computational algorithms, is presented. Further, we systematically review related topological models, including graphs, simplicial complexes, persistent homology, persistent Laplacians, de Rham-Hodge theory, Yau-Hausdorff distance, and the topology-based machine learning models.

13.
Phys Rev Lett ; 125(18): 183002, 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-33196244

RESUMO

The hyperfine structures of the 2^{3}S_{1} states of the ^{6}Li^{+} and ^{7}Li^{+} ions are investigated theoretically to extract the Zemach radii of the ^{6}Li and ^{7}Li nuclei by comparing with precision measurements. The obtained Zemach radii are larger than the previous values of Puchalski and Pachucki [Phys. Rev. Lett. 111, 243001 (2013)PRLTAO0031-900710.1103/PhysRevLett.111.243001] and disagree with them by about 1.5 and 2.2 standard deviations for ^{6}Li and ^{7}Li, respectively. Furthermore, our Zemach radius of ^{6}Li differs significantly from the nuclear physics value, derived from the nuclear charge and magnetic radii [Phys. Rev. A 78, 012513 (2008)PLRAAN1050-294710.1103/PhysRevA.78.012513] by more than 6σ, indicating an anomalous nuclear structure for ^{6}Li. The conclusion that the Zemach radius of ^{7}Li is about 40% larger than that of ^{6}Li is confirmed. The obtained Zemach radii are used to calculate the hyperfine splittings of the 2^{3}P_{J} states of ^{6,7}Li^{+}, where an order of magnitude improvement over the previous theory has been achieved for ^{7}Li^{+}.

14.
BMC Plant Biol ; 19(1): 156, 2019 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31023216

RESUMO

BACKGROUND: Seed germination and seedling establishment are two of the most critical phases in plant development. However, the molecular mechanisms underlying the effect of phosphorus on seed germination and post-germinated growth of oilseed rape are unclear so far. Here, we report the role of BnPHT1;4 in seed germination and early seedling development of Brassica napus. RESULTS: Our results show that BnPHT1;4 is preferentially expressed in cotyledons of early developing seedlings. Overexpression of BnPHT1;4 in oilseed rape promoted seed germination and seedling growth. Expression levels of the genes related to ABA and GA biosynthesis and signaling were significantly altered in BnPHT1;4 transgenic seedlings. Consequently, active GA level was up-regulated, whereas ABA content was down-regulated in BnPHT1;4 transgenic seedlings. Furthermore, exogenous GA could promote seed germination of wild type, while exogenous ABA could partially recover the advanced-germination phenotype of BnPHT1;4 transgenic seeds. Total phosphorus content in cotyledons of the transgenic seedlings was decreased more rapidly than that in wild type when Pi was supplied or deficient, and Pi contents in shoots and roots of the BnPHT1;4 transgenic plants were higher than those in wild type under high and low Pi conditions. CONCLUSIONS: Our data suggest that the high-affinity transporter BnPHT1;4 is involved in phosphorus acquisition and mobilization for facilitating seed germination and seedling growth of Brassica napus by modulating ABA and GA biosynthesis.


Assuntos
Brassica napus/metabolismo , Germinação , Proteínas de Membrana Transportadoras/metabolismo , Fósforo/metabolismo , Proteínas de Plantas/metabolismo , Plântula/crescimento & desenvolvimento , Sementes/crescimento & desenvolvimento , Ácido Abscísico/biossíntese , Brassica napus/genética , Cotilédone/metabolismo , Regulação da Expressão Gênica de Plantas , Giberelinas/biossíntese , Proteínas de Membrana Transportadoras/genética , Fenótipo , Fósforo/deficiência , Proteínas de Plantas/genética , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas , Plântula/metabolismo , Sementes/metabolismo , Solo
15.
Plant Physiol ; 178(1): 413-427, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30026290

RESUMO

PHOSPHATE STARVATION RESPONSE1 (PHR1) is a key regulatory component of the response to phosphate (Pi) starvation. However, the regulation of PHR1 in this response remains poorly understood. Here, we report that PHR1 is a target of the transcription factors AUXIN RESPONSE FACTOR7 (ARF7) and ARF19 and is positively regulated by auxin signaling in Arabidopsis (Arabidopsis thaliana) roots. PHR1 expression was induced by exogenous auxin and suppressed by auxin transport inhibitors in Arabidopsis roots. In the PHR1 promoter, three auxin-response elements, which are bound directly by ARF7 and ARF19, were shown to be essential for PHR1 expression. The arf7, arf19, and arf7 arf19 mutants showed down-regulated expression of PHR1 and downstream Pi starvation-induced genes in roots; they also exhibited defective Pi uptake in roots and overaccumulation of anthocyanin in shoots. The induction of lateral root formation in response to low Pi and to exogenous auxin was decreased in the phr1 mutant, whereas the expression of LATERAL ORGAN BOUNDARIES-DOMAIN16 (LBD16) and LBD29 was not changed significantly. PHR1 acted independently of LBD16 and LBD29 in the regulation of lateral root formation in response to low Pi. Under low-Pi conditions, lateral root impairment in the arf7 arf19 mutant was partially rescued by constitutive expression of PHR1, demonstrating that reduced PHR1 expression contributed to the arf7 arf19 phenotype. In addition to PHR1, other genes encoding MYB-CC members also were targets of ARF7 and ARF19. Our work thus reveals a mechanism coordinating auxin signaling and the PHR1 regulon in Arabidopsis responses to Pi deficiency.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Raízes de Plantas/genética , Fatores de Transcrição/genética , Antocianinas/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Ácidos Indolacéticos/metabolismo , Ácidos Indolacéticos/farmacologia , Mutação , Fosfatos/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Reguladores de Crescimento de Plantas/farmacologia , Raízes de Plantas/metabolismo , Brotos de Planta/genética , Brotos de Planta/metabolismo , Plantas Geneticamente Modificadas , Ligação Proteica , Elementos de Resposta/genética , Fatores de Transcrição/metabolismo
16.
Nanotechnology ; 28(9): 095201, 2017 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-28067205

RESUMO

We report a highly efficient tunable THz reflector in graphene. By applying a small gate voltage (up to ±3 V), the reflectance of graphene is modulated from a minimum of 0.79% to a maximum of 33.4% using graphene/ionic liquid structures at room temperature, and the reflection tuning is uniform within a wide spectral range (0.1-1.5 THz). Our observation is explained by the Drude model, which describes the THz wave-induced intraband transition in graphene. This tunable reflectance of graphene may contribute to broadband THz mirrors, deformable THz mirrors, variable THz beam splitters and other optical components.

17.
AAPS PharmSciTech ; 18(8): 3227-3235, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28560505

RESUMO

Liposomes, the biocompatible lipid bilayer vesicles, have attracted immense attention due to their distinctive features such as efficient vehicle for the delivery of a wide range of therapeutic agents, adjustable formulation properties, and high drug entrapment efficiency. In this contribution, we present a simple method for the preparation of liposomes using glass beads and compared the potential of this method with conventional methods of liposome preparation. The prepared liposomes were characterized by different analytical techniques (HPLC, DLS, TEM, differential scanning calorimetry, and in vitro drug release). Our findings revealed that the particle size of liposomes is mainly dependent on the size of the glass beads and the glass bead shearing time. An average liposome size of 67.7 ± 25.5 nm was obtained using 2-mm glass beads after 24-h incubation at 200 rpm. The liposomes prepared under the optimized conditions exhibited a high encapsulation efficiency of 92.1 ± 1.7% with 31.08% drug release after 360 min at 37°C. In conclusion, the developed method is a simple and convenient process of liposome preparation of different sizes with desirable entrapment efficiency capacity.


Assuntos
Vidro/química , Lipossomos/síntese química , Lipossomos/economia , Tamanho da Partícula , Anfotericina B/síntese química , Anfotericina B/economia , Varredura Diferencial de Calorimetria/economia , Varredura Diferencial de Calorimetria/métodos , Química Farmacêutica/economia , Química Farmacêutica/métodos , Colesterol/síntese química , Colesterol/economia , Análise Custo-Benefício , Fosfatidilcolinas/síntese química , Fosfatidilcolinas/economia , Resistência ao Cisalhamento
18.
Guang Pu Xue Yu Guang Pu Fen Xi ; 37(3): 841-6, 2017 Mar.
Artigo em Zh, Inglês | MEDLINE | ID: mdl-30160396

RESUMO

Soil water content (θ) is an important factor for the crop growth and crop production. The objectives of this study were to (i) test various regression models for estimating θ based on spectral feature parameters, and (ii) compare the performance of the proposed models by using artificial neural networks (ANN) and spectral feature parameters. The θ data of sand and loam and concurrent spectral parameters were acquired at the laboratory experiment in 2014. The results showed that: (1) the maximum reflectance with 900~970 nm and the sum reflectance within 900~970 nm estimate θ had the significant, when sand bulk density was 1.40 g·cm-3; the maximum reflectance with blue edge and the sum reflectance within 900~970 nm had the best correlation (R2>0.70) when sand bulk density was 1.50 g·cm-3; while soil bulk density was 1.60 g·cm-3, the sum reflectance within 780~970 nm and normalized absorption depth in 560~760 nm reached a significant (R2>0.90); when soil bulk density was 1.70 g·cm-3, the maximum reflectance with 900~970 nm and the sum reflectance within 900~970 nm had the best correlation estimate θ (R2>0.88). 2) When the soil type was loam, the maximum reflectance with 900~970 nm and the sum reflectance within 900~970 nm had a best correlation estimate θ. The spectral feature parameters the sum reflectance within blue edge (R2=0.26 and RMSE=0.09 m3·m-3) and 780~970 nm absorption depth (R2=0.32 and RMSE=0.10 m3·m-3) were best correlated with θ in the sand. The θ model based on maximum reflectance with 900~970 nm (R2=0.92 and RMSE=0.05 m3·m-3) and the sum reflectance within 900~970 nm had a high correlation (R2=0.92 and RMSE=0.04 m3·m-3) in the loam. The BP-ANN model presented a better estimation accuracy of θ (R2=0.87 and RMSE=0.05 m3·m-3) in two soils. Thus, the ANN model has great potential for estimating θ. Thus, the BP-ANN model has great potential for θ estimation.

19.
J Membr Biol ; 248(6): 1071-8, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26087905

RESUMO

Arsenic is successfully used in cancer chemotherapy and several cancer treatments on account of its apoptogenic effects. However, it is environmentally hazardous with potential for toxicity when distributed in the soil, water, and food, and long exposure to water contaminated with Arsenic may induce cancers. Some research studies have reported that liver is the storage site and an important target organ for Arsenic toxicity. In the present work, a new kind of organic arsenic compound, 4-(2-nitrobenzaliminyl) phenyl arsenoxide (NPA), was synthesized, and its potential involvement of mitochondria was explored. The results presented that the toxicology of NPA, at least in part, mediated mitochondrial function and may thoroughly destroy mitochondrial membrane physiological functions. NPA induced mitochondrial permeability transition pore (mtPTP) opening that induces mitochondrial biochemical abnormalities as evidenced by mitochondrial swelling, mitochondrial membrane potential breakdown, membrane fluidity alterations, and the strikingly remarkable protection of CsA. Meanwhile, both the decreased respiration rate of state 4 and the increased inner membrane H(+) permeabilization revealed that the inner membrane function regarding important energy production chain was destroyed. The toxicity of NPA is due to its interaction with mitochondrial membrane thiol protein. This conclusion is based on the protective effects of RR, DTT, and MBM(+).


Assuntos
Arsenicais/farmacologia , Mitocôndrias Hepáticas/efeitos dos fármacos , Mitocôndrias Hepáticas/metabolismo , Animais , Permeabilidade da Membrana Celular/efeitos dos fármacos , Respiração Celular , Ciclosporina/farmacologia , Hidrogênio/metabolismo , Peroxidação de Lipídeos , Fluidez de Membrana/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Proteínas de Transporte da Membrana Mitocondrial , Membranas Mitocondriais/química , Membranas Mitocondriais/metabolismo , Poro de Transição de Permeabilidade Mitocondrial , Consumo de Oxigênio , Potássio/metabolismo , Ratos
20.
J Membr Biol ; 248(2): 319-26, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25650179

RESUMO

The production capacity and yield of neodymium (Nd) in China have ranked the first in the world. Because of its unique biophysical and biochemical properties, Nd compounds have entered into the agricultural environment greatly to promote plant growth. Mitochondria play a crucial role in respiration and metabolism during the growth of plants. However, little is known about the mechanism by which Nd act at the mitochondrial level in plant cells. In this study, rice mitochondrial swelling, collapsed transmembrane potential and decreased membrane fluidity were examined to be important factors for mitochondria permeability transition pore (mPTP) opening induced by Nd(III). The protection of cyclosporin A (CsA) and dithiothreitol (DTT) could confirm that Nd(III) could trigger mPTP opening. Additionally, mitochondrial membrane breakdown observed by TEM and the release of cytochrome c (Cyt c) could also elucidate the mPTP opening from another point of view. At last, the study showed that Nd(III) could restrain the mitochondrial membrane lipid peroxide, so it might interact with anionic lipid too. This detection will be conductive to the safe application of Nd compounds in agriculture and food industry.


Assuntos
Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Neodímio/farmacologia , Oryza/efeitos dos fármacos , Oryza/metabolismo , Citocromos c/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Fluidez de Membrana/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Microscopia , Mitocôndrias/ultraestrutura , Dilatação Mitocondrial/efeitos dos fármacos , Permeabilidade/efeitos dos fármacos , Análise Espectral
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