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1.
Bioinspir Biomim ; 19(5)2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38876097

RESUMO

Gravitational forces can induce deviations in body posture from desired configurations in multi-legged arboreal robot locomotion with low leg stiffness, affecting the contact angle between the swing leg's end-effector and the climbing surface during the gait cycle. The relationship between desired and actual foot positions is investigated here in a leg-stiffness-enhanced model under external forces, focusing on the challenge of unreliable end-effector attachment on climbing surfaces in such robots. Inspired by the difference in ceiling attachment postures of dead and living geckos, feedforward compensation of the stance phase legs is the key to solving this problem. A feedforward gravity compensation (FGC) strategy, complemented by leg coordination, is proposed to correct gravity-influenced body posture and improve adhesion stability by reducing body inclination. The efficacy of this strategy is validated using a quadrupedal climbing robot, EF-I, as the experimental platform. Experimental validation on an inverted surface (ceiling walking) highlights the benefits of the FGC strategy, demonstrating its role in enhancing stability and ensuring reliable end-effector attachment without external assistance. In the experiment, robots without FGC only completed 3 out of 10 trials, while robots with FGC achieved a 100% success rate in the same trials. The speed was substantially greater with FGC, achieving 9.2 mm s-1in the trot gait. This underscores the proposed potential of the FGC strategy in overcoming the challenges associated with inconsistent end-effector attachment in robots with low leg stiffness, thereby facilitating stable locomotion even at an inverted body attitude.


Assuntos
, Gravitação , Lagartos , Locomoção , Robótica , Robótica/instrumentação , Robótica/métodos , Animais , Locomoção/fisiologia , Lagartos/fisiologia , Pé/fisiologia , Marcha/fisiologia , Fenômenos Biomecânicos , Biomimética/instrumentação , Biomimética/métodos , Desenho de Equipamento , Dedos do Pé/fisiologia , Modelos Biológicos
2.
Lipids Health Dis ; 23(1): 144, 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38760797

RESUMO

BACKGROUND: Cancer-associated cachexia (CAC) arises from malignant tumors and leads to a debilitating wasting syndrome. In the pathophysiology of CAC, the depletion of fat plays an important role. The mechanisms of CAC-induced fat loss include the enhancement of lipolysis, inhibition of lipogenesis, and browning of white adipose tissue (WAT). However, few lipid-metabolic enzymes have been reported to be involved in CAC. This study hypothesized that ELOVL6, a critical enzyme for the elongation of fatty acids, may be involved in fat loss in CAC. METHODS: Transcriptome sequencing technology was used to identify CAC-related genes in the WAT of a CAC rodent model. Then, the expression level of ELOVL6 and the fatty acid composition were analyzed in a large clinical sample. Elovl6 was knocked down by siRNA in 3T3-L1 mouse preadipocytes to compare with wild-type 3T3-L1 cells treated with tumor cell conditioned medium. RESULTS: In the WAT of patients with CAC, a significant decrease in the expression of ELOVL6 was found, which was linearly correlated with the extent of body mass reduction. Gas chromatographic analysis revealed an increase in palmitic acid (C16:0) and a decrease in linoleic acid (C18:2n-6) in these tissue samples. After treatment with tumor cell-conditioned medium, 3T3-L1 mouse preadipocytes showed a decrease in Elovl6 expression, and Elovl6-knockdown cells exhibited a reduction in preadipocyte differentiation and lipogenesis. Similarly, the knockdown of Elovl6 in 3T3-L1 cells resulted in a significant increase in palmitic acid (C16:0) and a marked decrease in oleic acid (C18:1n-9) content. CONCLUSION: Overall, the expression of ELOVL6 was decreased in the WAT of CAC patients. Decreased expression of ELOVL6 might induce fat loss in CAC patients by potentially altering the fatty acid composition of adipocytes. These findings suggest that ELOVL6 may be used as a valuable biomarker for the early diagnosis of CAC and may hold promise as a target for future therapies.


Assuntos
Células 3T3-L1 , Tecido Adiposo Branco , Caquexia , Elongases de Ácidos Graxos , Neoplasias , Elongases de Ácidos Graxos/genética , Elongases de Ácidos Graxos/metabolismo , Animais , Caquexia/genética , Caquexia/metabolismo , Caquexia/patologia , Camundongos , Tecido Adiposo Branco/metabolismo , Tecido Adiposo Branco/patologia , Humanos , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/complicações , Neoplasias/patologia , Masculino , Feminino , Ácido Palmítico/metabolismo , Lipogênese/genética , Pessoa de Meia-Idade , Ácidos Graxos/metabolismo
3.
Sci Rep ; 14(1): 3465, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38342931

RESUMO

The freezing damage of rock tunnels in cold region involves ice-water phase change and complicated interaction of Thermo-Hydro-Mechanical (THM) field. Taking the fractured rock mass of cold region tunnels as research subject, the THM coupling model of cold region tunnels was established, which is based on the seepage mechanics, heat transfer theory, damage mechanics and equivalent continuum theory. This model could reflect the anisotropic properties of deformation, water migration and heat transfer caused by the initial fracture of rock mass. The construction and operation processes of a rock tunnel in cold region were simulated, and results were compared with the measured value and predecessor's achievements. It shows that proposed model could reflect the anisotropic property of surrounding rock and the simulated deformation and stress are not symmetrical. Compared with the literature, the calculated results in this paper are closer to the measured values. The insulating layer has a significant effect on the stress of the supporting structures. The maximum tension stress of the lining is 4.5 times as that without insulating layer, and the lining will be destroyed for the overlarge tension stress.

4.
Mycoses ; 66(9): 795-800, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37226871

RESUMO

BACKGROUND: Mucormycosis is a rare form of invasive, rapidly progressive and lethal opportunistic fungal infection caused by Mucorales. Although Rhizopus arrhizus (R. arrhizus) is the most commonly isolated Mucorales worldwide, infections caused by Apophysomyces variabilis (A. variabilis) are increasing. OBJECTIVES AND METHODS: We present a case of necrotizing fasciitis caused by A. variabilis in an immunocompetent woman. In order to further understand the characteristics of the strain isolated from the patient, we identified the strain through ITS sequencing, assessed the ability to tolerate salt concentrations and temperature conditions, in addition to performing in vitro drug susceptibility testing against common antifungal agents. RESULTS: The strain showed 98.76% identity with A. variabilis in the NCBI database, and it was found to tolerate higher temperatures and salt concentrations than previously reported strains. The strain was sensitive to amphotericin B and posaconazole, but not to voriconazole, itraconazole, 5-fluorocytosine and echinocandins. CONCLUSIONS: This case indicates that Mucorales caused by A. variabilis should be recognised as an emerging pathogen that can cause a high mortality rate in the absence of prompt diagnosis and proper treatment in China, aggressive surgical debridement combined with prompt and appropriate antifungal treatment may improve outcomes.


Assuntos
Mucorales , Mucormicose , Mycobacterium tuberculosis , Feminino , Humanos , Testes de Sensibilidade Microbiana , Antifúngicos/uso terapêutico , Mucormicose/diagnóstico , Mucormicose/tratamento farmacológico , Mucormicose/microbiologia
5.
J Org Chem ; 88(7): 4494-4503, 2023 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-36972416

RESUMO

The mechanism of the rhodium-catalyzed C-H alkenylation/directing group migration and [3+2] annulation of N-aminocarbonylindoles with 1,3-diynes has been investigated with DFT calculations. On the basis of mechanistic studies, we mainly focus on the regioselectivity of 1,3-diyne inserting into the Rh-C bond and the N-aminocarbonyl directing group migration involved in the reactions. Our theoretical study uncovers that the directing group migration undergoes a stepwise ß-N elimination and isocyanate reinsertion process. As studied in this work, this finding is also applicable to other relevant reactions. Additionally, the role of Na+ versus Cs+ involved in the [3+2] cyclization reaction is also probed.

6.
Sensors (Basel) ; 22(19)2022 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-36236734

RESUMO

To avoid depth-of-field mismatches caused by the changes in pipe structure and image overexposures caused by highly reflective surfaces while radial imaging irregular pipes, this paper proposes a novel all-in-focus, adaptable, and low scene-coupling method that suppresses overexposures in support of fault detection. Firstly, the pipeline's radial depth distribution data are obtained by sensors, and an optimal all-in-focus imaging scheme is established by combining camera parameters. Secondly, using digital imaging technology, the high reflection effect produced by disparate light sources is comprehensively evaluated for overexposure suppression. Thirdly, a device is designed for imaging non-Lambertian free-form surface scenes under low illumination, providing the sequence images needed for the next step. Lastly, specific digital fusions are made to the sequential images to obtain an all-in-focus final image without overexposure. An image-quality analysis method is then used to measure the efficacy of the system in obtaining the characteristic information of the inner surfaces of an irregular pipe. Results of the experiment show that the method and device used are able to distinguish small 0.5 mm wide lines ranging from 40-878 mm depth and are capable of providing efficient image support for defect inspection of irregular pipes and free-form surfaces amongst other irregular surfaces.

7.
Angew Chem Int Ed Engl ; 61(18): e202116534, 2022 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-35174939

RESUMO

The performance enhancement of inverted perovskite solar cells applying nickel oxide (NiOx ) as the hole transport layer (HTL) has been limited by impurity ions (such as nitrate ions). Herein, we have proposed a strategy to obtain high-quality NiOx nanoparticles via an ionic liquid-assisted synthesis method (NiOx -IL). Experimental and theoretical results illustrate that the cation of the ionic liquid can inhibit the adsorption of impurity ions on nickel hydroxide through a strong hydrogen bond and low adsorption energy, thereby obtaining NiOx -IL HTL with high conductivity and strong hole-extraction ability. Importantly, the removal of impurity ions can effectively suppress the redox reaction between the NiOx film and the perovskite film, thus slowing down the deterioration of device performance. Consequently, the modified inverted device shows a striking efficiency exceeding 22.62 %, and superior stability maintaining 92 % efficiency at a maximum power point tracking under one sun illumination for 1000 h.

8.
Sci Adv ; 7(28)2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34233877

RESUMO

Stabilizing high-efficiency perovskite solar cells (PSCs) at operating conditions remains an unresolved issue hampering its large-scale commercial deployment. Here, we report a star-shaped polymer to improve charge transport and inhibit ion migration at the perovskite interface. The incorporation of multiple chemical anchor sites in the star-shaped polymer branches strongly controls the crystallization of perovskite film with lower trap density and higher carrier mobility and thus inhibits the nonradiative recombination and reduces the charge-transport loss. Consequently, the modified inverted PSCs show an optimal power conversion efficiency of 22.1% and a very high fill factor (FF) of 0.862, corresponding to 95.4% of the Shockley-Queisser limited FF (0.904) of PSCs with a 1.59-eV bandgap. The modified devices exhibit excellent long-term operational and thermal stability at the maximum power point for 1000 hours at 45°C under continuous one-sun illumination without any significant loss of efficiency.

9.
ACS Appl Mater Interfaces ; 12(39): 44297-44306, 2020 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-32805950

RESUMO

The competition between charge recombination and extraction principally affects the fill factor (FF) and power conversion efficiency (PCE) of planar thin-film solar cells. In Sb2S3 thin-film solar cells, the electrocharge recombination and extraction n transport layer (ETL) plays a significant role in electron extraction and determination of Sb2S3 film absorber quality. Herein, a TiO2 ETL is strategically modified using an inorganic salt zinc halide (i.e., ZnCl2, ZnBr2, ZnI2), which simultaneously improves the electronic properties of TiO2 and promotes the growth of Sb2S3 films with larger grain size and higher crystallinity. The experimental results and theoretical calculations further reveal that the zinc halide can interact with TiO2 and simultaneously bond strongly with the upper Sb2S3 film, which creates a unique pathway for electron transfer, passivates the trap states, and alleviates the recombination losses effectively. As a result, an average PCE of 6.87 ± 0.11% and the highest PCE of 7.08% have been attained with an improved FF from 51.22 to 61.61% after ZnCl2 introduction. Additionally, introduction of ZnCl2 helps the unencapsulated devices to maintain 93% of their original performance after 2400 h of storage in a nitrogen-filled glovebox. This work develops an effective route for the optimization of ETLs and defect healing using simple and low-cost inorganic salts.

10.
ACS Appl Mater Interfaces ; 12(4): 4970-4979, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31698902

RESUMO

Interfaces in Sb2S3 thin-film solar cells strongly affect their open-circuit voltage (VOC) and power conversion efficiency (PCE). Finding an effective method of reducing the defects is a promising approach for increasing the VOC and PCE. Herein, the use of an inorganic salt SbCl3 is reported for post-treatment on Sb2S3 films for surface passivation. It is found that a thin SbCl3 layer could form on the Sb2S3 surface and produce higher efficiency cells by reducing the defects and suppressing nonradiative recombination. Through density functional theory calculations, it is found that the passivation of the Sb2S3 surface by SbCl3 occurs via the interactions of Sb and Cl in SbCl3 molecules with S and Sb in Sb2S3, respectively. As a result, incorporating the SbCl3 layer highly improves the VOC from 0.58 to 0.72 V; an average PCE of 6.9 ± 0.1% and a highest PCE of 7.1% are obtained with an area of 0.1 cm2. The achieved PCE is the highest value in the Sb2S3 planar solar cells. In addition, the incorporated SbCl3 layer also leads to good stability of Sb2S3 devices, by which 90% of the initial performance is maintained for 1080 h of storage under ambient humidity (85 ± 5% relative humidity) at room temperature.

11.
Front Chem ; 7: 76, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30873400

RESUMO

In this study, a rapid and sensitive immunochromatographic strip (ICS) assay, based on quantum dots (QDs), was developed for the qualitative and quantitative detection of acetamiprid in agricultural samples. Acetamiprid-ovalbumin conjugates (ACE-OVA) and goat anti-mouse IgG were sprayed onto a nitrocellulose membrane as a test and control line. Two kinds of anti-acetamiprid monoclonal antibodies (mAb) obtained in our lab were characterized by the ELISA and surface plasmon resonance assay. The competitive immunoassay was established using a QDs-mAb conjugate probe. The visual detection limit of acetamiprid for a qualitative threshold was set as 1 ng/mL to the naked eye. In the quantitative test, the fluorescence intensity was measured by a portable strip reader and a standard curve was obtained with a linear range from 0.098 to 25 ng/mL, and the half maximal inhibitory concentration of 1.12 ng/mL. The developed method showed no evident cross-reactivities with other neonicotinoid insecticides except for thiacloprid (36.68%). The accuracy and precision of the developed QDs-ICS were further evaluated. Results showed that the average recoveries ranged from 78.38 to 126.97% in agricultural samples. Moreover, to test blind tea samples, the QDs-ICS showed comparable reliability and a high correlation with ultra-performance liquid chromatography-tandem mass spectrometry. The whole sample detection could be accomplished within 1 h. In brief, our data clearly manifested that QDs-ICS was quite qualified for the rapid and sensitive screening of acetamiprid residues in an agricultural product analysis and paves the way to point-of-care testing for other analytes.

12.
J Agric Food Chem ; 65(46): 10107-10114, 2017 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-29077402

RESUMO

Neonicotinoid insecticides are commonly used for pest control on tea plantations as a result of their broad-spectrum activity. However, neonicotinoid residues released from tea leaves into tea infusions pose a dietary risk to consumers. Therefore, a rapid, sensitive, and reliable on-site detection method for neonicotinoids is needed. We developed a quantum-dot-based fluorescent lateral flow immunochromatographic strip (LFICS) combined with a broad-specific antibody for detection of typical neonicotinoids (imidacloprid, imidaclothiz, and clothianidin), with sensitivities [50% inhibitory concentration (IC50)] of 0.104-0.33 ng/mL and visual detection limits of 0.5-1 ng/mL. The strip assay could be completed in less than 30 min. Using the LFICS to analyze spiked tea samples (green tea, black tea, and oolong tea), the average recovery of the three neonicotinoids ranged between 71 and 111%, with the coefficient of variation below 12%. The results from the LFICS tests for field samples were consistent with results from ultraperformance liquid chromatography-tandem mass spectrometry. The newly developed strip is a useful tool for the on-site detection of neonicotinoid residues in tea.


Assuntos
Imunoensaio/métodos , Inseticidas/análise , Neonicotinoides/análise , Resíduos de Praguicidas/análise , Pontos Quânticos/química , Chá/química , Camellia sinensis/química , Imunoensaio/instrumentação , Limite de Detecção
13.
Sci Rep ; 7: 43940, 2017 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-28266626

RESUMO

Tamoxifen is administered for estrogen receptor positive (ER+) breast cancers, but it can induce uterine endometrial cancer and non-alcoholic fatty liver disease (NAFLD). Importantly, ten years of tamoxifen treatment has greater protective effect against ER+ breast cancer than five years of such treatment. Tamoxifen was also approved by the FDA as a chemopreventive agent for those deemed at high risk for the development of breast cancer. The side effects are of substantial concern because of these extended methods of tamoxifen administration. In this study, we found that anordrin, marketed as an antifertility medicine in China, inhibited tamoxifen-induced endometrial epithelial cell mitosis and NAFLD in mouse uterus and liver as an anti-estrogenic and estrogenic agent, respectively. Additionally, compared with tamoxifen, anordiol, the active metabolite of anordrin, weakly bound to the ligand binding domain of ER-α. Anordrin did not regulate the classic estrogen nuclear pathway; thus, it did not affect the anti-tumor activity of tamoxifen in nude mice. Taken together, these data suggested that anordrin could eliminate the side effects of tamoxifen without affecting its anti-tumor activity.


Assuntos
Antineoplásicos Hormonais/efeitos adversos , Anticoncepcionais Orais Sintéticos/administração & dosagem , Neoplasias do Endométrio/prevenção & controle , Hepatopatia Gordurosa não Alcoólica/prevenção & controle , Norandrostanos/administração & dosagem , Tamoxifeno/efeitos adversos , Animais , Antineoplásicos Hormonais/administração & dosagem , Antineoplásicos Hormonais/farmacologia , Linhagem Celular Tumoral , Neoplasias do Endométrio/induzido quimicamente , Feminino , Xenoenxertos , Humanos , Camundongos Endogâmicos ICR , Camundongos Nus , Transplante de Neoplasias , Hepatopatia Gordurosa não Alcoólica/induzido quimicamente , Tamoxifeno/administração & dosagem , Tamoxifeno/farmacologia , Resultado do Tratamento
14.
J Immunoassay Immunochem ; 36(5): 487-95, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25522905

RESUMO

Inositol 1, 4, 5-Trisphosphate Receptor (InsP3R) is an intracellular Ca(2+) release channel, which widely participates in cellular processes. Three isoforms of InsP3R were identified as InsP3R1, InsP3R2, and InsP3R3. They share 60-0% protein sequence homology and form a channel in a manner of homotetramer or heterotetramer. Several InsP3R isoform-specific rabbit antibodies have been generated to distinguish their localization and functions. However, there is no report of such a valid antibody raised from other species. In his article, we prepare a mouse monoclonal antibody against a synthetic peptide with rat InsP3R1-specific carboxyl terminus sequence. This monoclonal antibody of InsP3R1 (R1-mAb) was purified and characterized as IgG2b, which can recognize InsP3R1 by Western-blot (WB) analysis and immunoprecipitate (IP) InsP3R1 from moue brain lysate tested. Applied in immunofluorescent (IF) and immunohistochemical (IHC) assays, this antibody and rabbit polyclonal antibody could give the consistent results in SH-SY5Y cells, human sperm, and mouse brain paraffin section. In summary, we generate a mouse InsP3R1-specific IgG 2b antibody identifying InsP3R1 in WB, IF, IHC, and IP analysis, which provides a possible choice for detection of InsP3R1, especially in application of co-localization analysis with other InsP3R isoforms or other proteins.


Assuntos
Anticorpos Monoclonais/imunologia , Receptores de Inositol 1,4,5-Trifosfato/imunologia , Animais , Anticorpos Monoclonais/sangue , Encéfalo/metabolismo , Linhagem Celular , Feminino , Humanos , Imuno-Histoquímica , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos ICR
15.
Mol Genet Genomics ; 289(6): 1157-69, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24952483

RESUMO

RT-qPCR is a commonly used method for evaluating gene expression; however, its accuracy and reliability are dependent upon the choice of appropriate reference gene(s), and there is limited information available on suitable reference gene(s) that can be used in mouse testis at different stages. In this study, using the RT-qPCR method, we investigated the expression variations of six reference genes representing different functional classes (Actb, Gapdh, Ppia, Tbp, Rps29, Hprt1) in mice testis during embryonic and postnatal development. The expression stabilities of putative reference genes were evaluated using five algorithms: geNorm, NormFinder, Bestkeeper, the comparative delta C(t) method and integrated tool RefFinder. Analysis of the results showed that Ppia, Gapdh and Actb were identified as the most stable genes and the geometric mean of Ppia, Gapdh and Actb constitutes an appropriate normalization factor for gene expression studies. The mRNA expression of AT1 as a test gene of interest varied depending upon which of the reference gene(s) was used as an internal control(s). This study suggested that Ppia, Gapdh and Actb are suitable reference genes among the six genes used for RT-qPCR normalization and provide crucial information for transcriptional analyses in future studies of gene expression in the developing mouse testis.


Assuntos
Expressão Gênica , Reação em Cadeia da Polimerase em Tempo Real/normas , Testículo/metabolismo , Algoritmos , Animais , Primers do DNA , Masculino , Camundongos , Receptor Tipo 1 de Angiotensina/genética , Padrões de Referência , Testículo/embriologia , Testículo/crescimento & desenvolvimento
16.
Mol Hum Reprod ; 15(4): 215-21, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19223336

RESUMO

During mammalian pregnancy, it has been demonstrated that the quality of embryo implantation determines the quality of ongoing pregnancy and fetal development. Recent studies have provided increasing evidence that differential Wnt signaling plays diverse roles in multiple peri-implantation events. This review focuses on recent progress on various aspects of Wnt signaling in preimplantation embryo development, blastocyst activation for implantation and uterine decidualization. Future studies with conditional deletion of Wnt family members are hoped to provide deeper insight on the pathophysiological significance of Wnt proteins on early pregnancy events.


Assuntos
Implantação do Embrião/fisiologia , Embrião de Mamíferos/fisiologia , Transdução de Sinais/fisiologia , Útero/metabolismo , Proteínas Wnt/metabolismo , Animais , Blastocisto/fisiologia , Feminino , Feto/fisiologia , Infertilidade Feminina , Gravidez , beta Catenina/metabolismo
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