Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 47
Filtrar
1.
Fish Shellfish Immunol ; 144: 109260, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38043874

RESUMO

To explore the immune defense mechanisms of the ancient crustacean fairy shrimp (B.kugenumaensis) and uncover antibacterial-related gene resources, the present study analyzed the pathological changes in B. kugenumaensis infected with E. anguillarum. Differential gene expression changes between the infected and uninfected groups were investigated through comparative transcriptome sequencing to elucidate the molecular responses to the infection. Under transmission electron microscopy, the intestinal mucosal structure of B. kugenumaensis was damaged, the microvilli disappeared, the number of mitochondria and endoplasmic reticulum increased, mitochondria vacuolated and arranged disordered. The transcriptome data indicated that a total of 250,520,580 clean reads were assembled into 66,502 unigenes, with an average length of 789 bp and an N50 length of 1326 bp. Following bacterial infection, approximately 2678 differentially expressed genes (DEGs) were identified, with 1732 genes upregulated and 946 genes downregulated. The detected DEGs related to immune responses, particularly involving apoptosis, lysosome, autophagy, phagosome, and MAPK signaling pathways. Moreover, 9 immunity-related genes with different expressions were confirmed by using real-time quantitative PCR (RT-qPCR). This study first reports the pathogenicity of E. anguillarum on B. kugenumaensis and speculates that immune effectors such as lysozyme and lectin, as well as apoptosis, lysosome, and the MAPK signaling pathway, play crucial roles in the innate immunity of fairy shrimp. These findings deepen our understanding of fairy shrimp immune regulatory mechanisms and provide a theoretical foundation for disease prevention and control.


Assuntos
Anostraca , Perfilação da Expressão Gênica , Animais , Perfilação da Expressão Gênica/veterinária , Transcriptoma , Imunidade Inata/genética
2.
Sleep Breath ; 28(1): 133-149, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37428351

RESUMO

PURPOSE: This study evaluated the effects of chronic intermittent hypoxia (CIH) at different times on the mitochondria of mouse hearts and H9C2 cardiomyocytes to determine the role of the cannabinoid receptor 1 (CB1R)/adenosine 5'-monophosphate-activated protein kinase (AMPK)/peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) signaling pathway. METHODS: Animal and cellular CIH models were prepared in an intermittent hypoxia chamber at different times. The cardiac function of mice was determined, and heart tissue and ultrastructural changes were observed. Apoptosis, reactive oxygen species (ROS), and mitochondrial membrane potential were detected, and MitoTracker™ staining was performed to observe cardiomyocyte mitochondria. Western blot, immunohistochemistry, and cellular immunofluorescence were also performed. RESULTS: In the short-term CIH group, increases in mouse ejection fraction (EF) and heart rate (HR); mitochondrial division; ROS and mitochondrial membrane potential; and the expression levels of CB1R, AMPK, and PGC-1α were observed in vivo and in vitro. In the long-term CIH group, the EF and HR increased, the myocardial injury and mitochondrial damage were more severe, mitochondrial synthesis decreased, the apoptosis percentage and ROS increased, mitochondrial fragmentation increased, membrane potential decreased, CB1R expression increased, and AMPK and PGC-1α expression levels decreased. Targeted blocking of CB1R can increase AMPK and PGC-1α, reduce damage attributed to long-term CIH in mouse hearts and H9C2 cells, and promote mitochondrial synthesis. CONCLUSION: Short-term CIH can directly activate the AMPK/PGC-1α pathway, promote mitochondrial synthesis in cardiomyocytes, and protect cardiac structure and function. Long-term CIH can increase CB1R expression and inhibit the AMPK/PGC-1α pathway, resulting in structural damage, the disturbance of myocardial mitochondria synthesis, and further alterations in the cardiac structure. After targeted blocking of CB1R, levels of AMPK and PGC-1α increased, alleviating damage to the heart and cardiomyocytes caused by long-term CIH.


Assuntos
Proteínas Quinases Ativadas por AMP , Miócitos Cardíacos , Camundongos , Animais , Miócitos Cardíacos/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Mitocôndrias/metabolismo , Transdução de Sinais , Hipóxia/metabolismo
3.
Acta Biochim Biophys Sin (Shanghai) ; 56(5): 740-752, 2024 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-38477044

RESUMO

Dysregulation of microRNA (miRNA) expression in cancer is a significant factor contributing to the progression of chemoresistance. The objective of this study is to explore the underlying mechanisms by which miR-34b-3p regulates chemoresistance in cervical cancer (CC). Previous findings have demonstrated low expression levels of miR-34b-3p in both CC chemoresistant cells and tissues. In this study, we initially characterize the behavior of SiHa/DDP cells which are CC cells resistant to the chemotherapeutic drug cisplatin (DDP). Subsequently, miR-34b-3p mimics are transfected into SiHa/DDP cells. It is observed that overexpression of miR-34b-3p substantially inhibits the proliferation, migration, and invasion abilities of SiHa/DDP cells and also enhances their sensitivity to DDP-induced cell death. Quantitative RT-PCR and western blot analysis further reveal elevated expression levels of STC2 and FN1 in SiHa/DDP cells, contrary to the expression pattern of miR-34b-3p. Moreover, STC2 and FN1 contribute to DDP resistance, proliferation, migration, invasion, and decreased apoptosis in CC cells. Through dual-luciferase assay analysis, we confirm that STC2 and FN1 are direct targets of miR-34b-3p in CC. Finally, rescue experiments demonstrate that overexpression of either STC2 or FN1 can partially reverse the inhibitory effects of miR-34b-3p overexpression on chemoresistance, proliferation, migration and invasion in CC cells. In conclusion, our findings support the role of miR-34b-3p as a tumor suppressor in CC. This study indicates that targeting the miR-34b-3p/STC2 or FN1 axis has potential therapeutic implications for overcoming chemoresistance in CC patients.


Assuntos
Proliferação de Células , Cisplatino , Resistencia a Medicamentos Antineoplásicos , Fibronectinas , MicroRNAs , Neoplasias do Colo do Útero , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/tratamento farmacológico , Feminino , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Linhagem Celular Tumoral , Fibronectinas/metabolismo , Fibronectinas/genética , Movimento Celular/genética , Movimento Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Apoptose/genética , Apoptose/efeitos dos fármacos , Antineoplásicos/farmacologia , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Glicoproteínas
4.
Acta Biochim Biophys Sin (Shanghai) ; 56(1): 23-33, 2024 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-38062774

RESUMO

Neural tube defects (NTDs) represent a developmental disorder of the nervous system that can lead to significant disability in children and impose substantial social burdens. Valproic acid (VPA), a widely prescribed first-line antiepileptic drug for epilepsy and various neurological conditions, has been associated with a 4-fold increase in the risk of NTDs when used during pregnancy. Consequently, urgent efforts are required to identify innovative prevention and treatment approaches for VPA-induced NTDs. Studies have demonstrated that the disruption in the delicate balance between cell proliferation and apoptosis is a crucial factor contributing to NTDs induced by VPA. Encouragingly, our current data reveal that melatonin (MT) significantly inhibits apoptosis while promoting the restoration of neuroepithelial cell proliferation impaired by VPA. Moreover, further investigations demonstrate that MT substantially reduces the incidence of neural tube malformations resulted from VPA exposure, primarily by suppressing apoptosis through the modulation of intracellular reactive oxygen species levels. In addition, the Src/PI3K/ERK signaling pathway appears to play a pivotal role in VPA-induced NTDs, with significant inhibition observed in the affected samples. Notably, MT treatment successfully reinstates Src/PI3K/ERK signaling, thereby offering a potential underlying mechanism for the protective effects of MT against VPA-induced NTDs. In summary, our current study substantiates the considerable protective potential of MT in mitigating VPA-triggered NTDs, thereby offering valuable strategies for the clinical management of VPA-related birth defects.


Assuntos
Melatonina , Defeitos do Tubo Neural , Gravidez , Feminino , Criança , Humanos , Ácido Valproico , Melatonina/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Defeitos do Tubo Neural/induzido quimicamente , Defeitos do Tubo Neural/prevenção & controle , Estresse Oxidativo , Transdução de Sinais
5.
Zhongguo Zhong Yao Za Zhi ; 48(22): 6191-6199, 2023 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-38114226

RESUMO

Simiao Yong'an Decoction is a classic prescription for treating gangrene. Modern medical evidence has proven that Si-miao Yong'an Decoction has therapeutic effects on atherosclerosis(AS), vascular occlusion angeitides, and hypertension, while its pharmacodynamic mechanism remains unclear. The evidence of network pharmacology, molecular docking, literature review, and our previous study suggests that luteolin and kaempferol are two major flavonoids in Simiao Yong'an Decoction and can inhibit macrophage inflammation and exert anti-AS effects. However, due to lack of the metabolism studies in vivo, little is known about the metabolic characteristics of luteolin and kaempferol. This study employed ultra-performance liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometry(UHPLC-LTQ-Orbitrap MS/MS) and relevant software to identify the metabolites and metabolic pathways of luteolin and kaempferol in rat plasma, urine, and feces, after oral administration of luteolin and kaempferol, respectively. After the administration of luteolin, 10, 11, and 3 metabolites of luteolin were detected in the plasma, urine, and feces, respectively. After the administration of kaempferol, 9, 3, and 1 metabolites of kaempferol were detected in the plasma, urine, and feces, respectively. The metabolic pathways mainly involved methylation, glucuronidation, and sulfation. This study enriches the knowledge about the pharmacological mechanism of luteolin and kaempferol and supplies a reference for revealing the metabolic process of other flavonoids in Simiao Yong'an Decoction, which is of great significance for elucidating the pharmacological effects and effective substances of this decoction in vivo.


Assuntos
Medicamentos de Ervas Chinesas , Espectrometria de Massas em Tandem , Ratos , Animais , Espectrometria de Massas em Tandem/métodos , Luteolina/análise , Medicamentos de Ervas Chinesas/química , Quempferóis/análise , Cromatografia Líquida de Alta Pressão/métodos , Simulação de Acoplamento Molecular
6.
Phys Chem Chem Phys ; 24(21): 12890-12897, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35583130

RESUMO

Different from conventional materials, structures with a negative Poisson's ratio (NPR) contract/expand laterally under a longitudinal compressive/tensile strain, usually exhibiting peculiar features. Through first-principles calculations, we investigate the electronic and transport properties of Pd9B16 molecules. Its Poisson's ratio is found to be negative under uniaxial strain along a specific direction. By contacting with Au nanowires, atomic Au chains and atomic C chain electrodes, two kinds of transitions for transmission states could be realized by the modulation of the strain and the contacting site, i.e., metallic-semiconducting transition and spin polarized-unpolarized transition. Further analysis shows that it is the suppression and shifting of density of states, caused by the strain or contacting electrodes, that trigger the transitions. Those findings combine NPR and spintronics at the single-molecule level, which may throw light on the development of nanoelectronic devices.

7.
Sensors (Basel) ; 22(4)2022 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-35214372

RESUMO

This article introduces a tracked-leg transformable robot, TALBOT. The mechanical and electrical design, control method, and environment perception based on LiDAR are discussed. The original tracked-leg transformable structure allows the robot to switch between the tracked and legged mode to achieve all-terrain adaptation. In the tracked mode, TALBOT is controlled by the method of differential speed between the two tracked feet. In the legged mode, TALBOT is controlled based on a bionic control strategy of the central pattern generator to realize the generation and conversion of gait. In addition, the robot is equipped with a LiDAR, through sensor preprocessing and optimization of the slam mapping algorithm, so that the robot achieves a better mapping effect. We tested the robot's motion performance and the slam mapping effect, including going straight and turning in tracked and legged modes and building a map in an indoor environment.


Assuntos
Robótica , Adaptação Fisiológica , Algoritmos , Marcha , Perna (Membro) , Robótica/métodos
8.
Zhongguo Zhong Yao Za Zhi ; 47(10): 2658-2667, 2022 May.
Artigo em Chinês | MEDLINE | ID: mdl-35718484

RESUMO

This study aims to identify the chemical constituents of Simiao Yong'an Decoction based on ultra-performance liquid chromatography coupled with linear quadrupole ion trap-orbitrap mass spectrometry(UPLC-LTQ-Orbitrap-MS). The elution was performed through a UPLC BEH C_(18) column(2.1 mm × 100 mm, 1.7 µm) with the mobile phase of water(containing 0.1% formic acid)-acetonitrile at a flow rate of 0.4 mL·min~(-1). LTQ-Orbitrap-MS with heat electrospray ion(HESI) source was employed to collect MS fragment information in the negative ion mode. A total of 72 compounds were identified based on reference substance comparison, fragmentation rules, accurate molecular weight, related reports and databases(MassBank and HMDB), including 30 iridoid glycosides, 9 organic acids, 15 flavonoids, 10 phenylpropanoids, 7 triterpenoids, and 1 saccharide. The method established in this study is comprehensive, rapid, and accurate, which can help summarize the fragmentation rules of constituents and provide reference for revealing the active constituents and pharmacodynamic mechanism of Simiao Yong'an Decoction.


Assuntos
Medicamentos de Ervas Chinesas , Triterpenos , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida , Medicamentos de Ervas Chinesas/química , Flavonoides/análise , Triterpenos/análise
9.
Mar Drugs ; 18(7)2020 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-32668657

RESUMO

Glyceroglycolipids, abundant in cyanobacteria's photosynthetic membranes, present bioactivities and pharmacological activities, and can be widely used in the pharmaceutical industry. Environmental factors could alter the contents and compositions of cyanobacteria glyceroglycolipids, but the regulation mechanism remains unclear. Therefore, the glyceroglycolipids contents and the transcriptome in Synechococcus elongatus PCC 7942 were analyzed under phosphate starvation. Under phosphate starvation, the decrease of monogalactosyl diacylglycerol (MGDG) and increases of digalactosyl diacylglycerol (DGDG) and sulfoquinovosyl diacylglycerol (SQDG) led to a decrease in the MGDG/DGDG ratio, from 4:1 to 5:3, after 12 days of cultivation. However, UDP-sulfoquinovose synthase gene sqdB, and the SQDG synthase gene sqdX, were down-regulated, and the decreased MGDG/DGDG ratio was later increased back to 2:1 after 15 days of cultivation, suggesting the regulation of glyceroglycolipids on day 12 was based on the MGDG/DGDG ratio maintaining glyceroglycolipid homeostasis. There are 12 differentially expressed transcriptional regulators that could be potential candidates related to glyceroglycolipid regulation, according to the transcriptome analysis. The transcriptome analysis also suggested post-transcriptional or post-translational regulations in glyceroglycolipid synthesis. This study provides further insights into glyceroglycolipid metabolism, as well as the scientific basis for glyceroglycolipid synthesis optimization and cyanobacteria glyceroglycolipids utilization via metabolic engineering.


Assuntos
Glicolipídeos/metabolismo , Metabolismo dos Lipídeos/genética , Synechococcus/genética , Synechococcus/metabolismo , Transcriptoma , Perfilação da Expressão Gênica , Regulação Bacteriana da Expressão Gênica , Redes Reguladoras de Genes , Fosfatos/deficiência , Fatores de Tempo
10.
Mikrochim Acta ; 187(10): 560, 2020 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-32915335

RESUMO

Silver nanoplates were for the first time synthesized on electrospun chitosan/polyethylene oxide (CS/PEO) fibers via tollens reaction. Ag nanoplates/CS/PEO fibers were used as the SERS-active substrates for quantitative evaluation of 2-naphthylthiol, with an enhancement factor (1.41 ± 0.07) × 106. The SERS-active substrates are flexible, stable, and easy for transportion and preservation, and act as the SERS platform for sensitive detection of the target. Thiram and thiabendazole as the representatives of pesticide residues were identified and detected by the Ag nanoplates/CS/PEO fibers, exhibiting linear response ranges from 10-11 to 10-7 M with a detection limit of 10-11 M. The Ag nanoplates/CS/PEO fibers meet the requirement of thiram detection in practical samples, such as apple, pear, tomato, and cucumber juices. The strategy revealed the feasibility of fabrication of Ag nanoplates on electrospun fibers via tollens reaction and SERS sensing of pesticides in real samples. Ag nanoplates/CS/PEO fibers were fabricated by tollens reaction and electrospinning for SERS sensing of pesticide residues with high sensitivity.


Assuntos
Nanopartículas Metálicas/química , Resíduos de Praguicidas/química , Prata/química , Humanos
11.
Mikrochim Acta ; 186(8): 542, 2019 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-31317336

RESUMO

Polyacrylonitrile fibers with and without magnetic nanoparticles (Fe3O4 NPs) were prepared by electrospinning. The pure polyacrylonitrile (PAN) fibers and the composited polyacrylonitrile (PAN/Fe3O4) fibers were studied with respect to their capability for enrichment of glycoproteins. Specifically, the glycoproteins ovalbumin (OB) and transferrin (Trf) were studied and compared to the non-glycoproteins bovine serum albumin and lysozyme. Following adsorption and subsequent protein elution with 0.1 wt% of CTAB solution, the glycoproteins were analyzed by SDS polyacrylamide gel electrophoresis. The strong interaction between PAN or PAN/Fe3O4 fibers and glycoproteins is attributed to the synergistic effects of hydrophilic and hydrogen bond interactions. The PAN/Fe3O4 fibers have an attractive additional feature of allowing magnetic separation. The PAN and PAN/Fe3O4 fibers have a high adsorption capacity toward OB and Trf. The treated PAN/Fe3O4 fibers display good selectivity, fast adsorption kinetics, and were applied to extractions of mixed protein samples. The detection limits of OB and Trf are 0.32 and 0.22 µg·mL-1, respectively. The PAN/Fe3O4 fibers offered an alternative solution for adsorption of glycoproteins from biological samples. Graphical abstract The pure polyacrylonitrile (PAN) fibers and the composited polyacrylonitrile (PAN/Fe3O4) fibers were studied with respect to their capability for enrichment of glycoproteins: glycoproteins ovalbumin (OB) and transferrin (Trf). The treated PAN/Fe3O4 fibers showed fast adsorption kinetics, were applied in a physiological state, mixed and real samples.


Assuntos
Resinas Acrílicas/química , Glicoproteínas/química , Nanopartículas de Magnetita/química , Ovalbumina/química , Transferrina/química , Adsorção , Muramidase/química , Soroalbumina Bovina/química
12.
Appl Opt ; 57(9): 2287-2291, 2018 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-29604027

RESUMO

A laser-diode-pumped broadband and continuously frequency-tuned all-solid-state Nd:YVO4 laser at 1064 nm with an output power of 200 mW is demonstrated. A RbTiOPO4 (RTP) etalon and a piezoelectric-transducer (PZT) are utilized for coarse and fine frequency tuning, respectively. Dependence of the frequency excursion on the applied voltage to the RTP etalon and the displacement of the PZT is theoretically and experimentally investigated. A continuous frequency tuning of 14 GHz is conducted by synchronous adjustment of the RTP etalon and the PZT. The tuning covers more than 6 times the longitudinal mode spacing of a laser resonator without any mode hops.

13.
Opt Express ; 25(19): 23199-23206, 2017 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-29041622

RESUMO

We demonstrate a linearly frequency-modulated laser from a laser diode (LD) pumped Nd:YVO4 laser. A fast frequency tuning of 2.40 THz/s with a tuning range of 6 GHz is achieved in LD pumped Nd:YVO4 1064 nm laser by using RbTiOPO4 (RTP) crystals as the frequency modulator. The continuous tuning range is more than 3 times the longitudinal mode spacing of the resonator. The maximum output power of frequency-modulated laser reaches 160 mW at 1064 nm. Linewidth of the single frequency laser is measured to be 190 kHz by a delay self-heterodyne interferometer. A deviation lower than 60 MHz is obtained during linear modulation.

14.
Appl Opt ; 56(33): 9150-9155, 2017 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-29216083

RESUMO

A continuously frequency-tuned laser diode end-pumped Nd:YVO4 laser at 1064 nm is demonstrated. A coated etalon and a piezoelectric-transducer (PZT) are utilized for coarse and fine frequency tuning, respectively. Broadband and linear frequency tuning without mode hops is conducted by the synchronous adjustment of the etalon and the PZT. Dependence of the frequency excursion on the displacement of the PZT and the tilting angle of the etalon are theoretically and experimentally investigated. A linear frequency tuning range up to 18 GHz without mode hops or frequency overlaps in a one-way non-stopped scanning is obtained. The maximum output power is 930 mW at 1064 nm, and the average frequency tuning speed is 1.24 GHz/s. Standard deviation of the frequency variation to a linear frequency tuning is estimated to be 186 MHz, indicating a high tuning linearity.

15.
Opt Express ; 22(20): 24655-65, 2014 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-25322040

RESUMO

A novel miniaturized Cr4⁺:YAG passively Q-switched Nd:YAG pulse-burst laser under 808 nm diode-laser pulse-pumping was demonstrated for the purpose of laser-induced plasma ignition, in which pulse-burst mode can realize both high repetition rate and high pulse energy simultaneously in a short period. Side-pumping configuration and two different types of laser cavities were employed. The pumping pulse width was constant at 250 µs. For the plane-plane cavity, the output beam profile was flat-top Gaussian and the measured M² value was 4.1 at the maximum incident pump energy of 600 mJ. The pulse-burst laser contained a maximum of 8 pulses, 7 pulses and 6 pulses for pulse-burst repetition rate of 10 Hz, 50 Hz and 100 Hz, respectively. The energy obtained was 15.5 mJ, 14.9 mJ and 13.9 mJ per pulse for pulse-burst repetition rate of 10 Hz, 50 Hz and 100 Hz, respectively. The maximum repetition rate of laser pulses in pulse-burst was 34.6 kHz for 8 pulses at the incident pump energy of 600 mJ and the single pulse width was 13.3 ns. The thermal lensing effect of Nd:YAG rod was investigated, and an plane-convex cavity was adopted to compensate the thermal lensing effect of Nd:YAG rod and improve the mode matching. For the plane-convex cavity, the output beam profile was quasi-Gaussian and the measured M2 value was 2.2 at the incident pump energy of 600 mJ. The output energy was 10.6 mJ per pulse for pulse-burst repetition rate of 100 Hz. The maximum repetition rate of laser pulses in pulse-burst was 27.4 kHz for 6 pulses at the incident pump energy of 600 mJ and the single pulse width was 14.2 ns. The experimental results showed that this pulse-burst laser can produce high repetition rate (>20 kHz) and high pulse energy (>10 mJ) simultaneously in a short period for both two different cavities.

16.
Appl Opt ; 53(14): 3081-4, 2014 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-24922030

RESUMO

In this paper, an electro-optical cavity-dumped 1.06 µm laser using YVO4/Nd:GdVO4 composite crystal under 808 nm diode-laser pumping was reported. Theoretical calculations showed that the temperature distribution in YVO4/Nd:GdVO4 crystal was lower than that in GdVO4/Nd:GdVO4 and Nd:GdVO4 crystals under the same conditions. A constant 3.8±0.3 ns pulse width was obtained and the repetition rate could reach up to 50 kHz with a maximum average output power of 5.6 W and slope efficiency of 40.7%, corresponding to a peak power of 31.1 kW.

17.
Int J Prosthodont ; 37(1): 109, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38381992

RESUMO

PURPOSE: To compare the static and dynamic occlusion of all-ceramic single crowns designed by mechanical and virtual articulators, by evalua6ng the accuracy of occlusal contacts of prostheses designed by virtual articulators and the feasibility of clinical application of CAD/CAM virtual articulators. MATERIALS AND METHODS: Nine subjects with an average age of 27 years who needed crown repair were recruited. After preparation of the all-ceramic crowns, two zirconia crowns were designed and fabricated through digital procedures and traditional methods. The intraoral scanner, Geomagic software, and T-Scan analyzer were used to analyze the occlusal contact points, areas, and the occlusal force percentage peak before the treatment and after the two crowns were temporarily fixed. RESULTS: There was a significant difference in the number of occlusal contact points and areas between the mechanical group and control group (preoperation group), but there was no obvious difference between the virtual group and control group. The occlusal contact overlapping areas of the virtual-control group were significantly larger than those of the mechanical-control group. The occlusal force percentage peak of the tested teeth was slightly larger in the mechanical group than in the virtual group. CONCLUSIONS: The posterior single crown designed by a virtual articulator restored the intercuspal occlusal better than one designed by a mechanical articulator, and it produced less dynamic occlusal interference. This finding suggests that virtual articulators can provide guidance for the design and adjustment of the occlusal surface of posterior single crown prostheses.


Assuntos
Coroas , Articuladores Dentários , Humanos , Adulto , Desenho Assistido por Computador , Dente Molar , Cerâmica , Planejamento de Prótese Dentária/métodos
18.
Talanta ; 279: 126615, 2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-39096787

RESUMO

The sensitive detection of analytes of different sizes is crucial significance for environmental protection, food safety and medical diagnostics. The confined space of nanochannels provides a location closest to the molecular reaction behaviors in real systems, thereby opening new opportunities for the precise detection of analytes. However, due to the susceptibility to external interference on the confined space of nanochannels, the high sensitivity nature of the current signals through the nanochannels is more troubling for the detection reliability. Combining highly sensitive optical signals with the sensitive current signals of solid-state nanochannels establishes a nanochannel detection platform based on electro-optical dual signals, potentially offering more sensitive, specific, and accuracy detection of analytes. This review summarizes the last five years of applications of solid-state nanochannels based on electro-optical dual signals in analytes detection. Firstly, the detection principles of solid-state nanochannels and the construction strategies of nanochannel electro-optical sensing platforms are discussed. Subsequently, the review comprehensively outlines the applications involving nanochannels with electrical signals combined with fluorescence signals, electrical signals combined with surface-enhanced Raman spectroscopy signals, and electrical signals combined with other optical signals in analyte detection. Additionally, the perspectives and difficulties of nanochannels are investigated on the basis of electro-optical dual signals.

19.
Materials (Basel) ; 17(9)2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38730933

RESUMO

High-nickel ternary materials are currently the most promising lithium battery cathode materials due to their development and application potential. Nevertheless, these materials encounter challenges like cation mixing, lattice oxygen loss, interfacial reactions, and microcracks. These issues are exacerbated at high voltages, compromising their cyclic stability and safety. In this study, we successfully prepared Nb5+-doped high-nickel ternary cathode materials via a high-temperature solid-phase method. We investigated the impact of Nb5+ doping on the microstructure and electrochemical properties of LiNi0.88Co0.05Mn0.07O2 ternary cathode materials by varying the amount of Nb2O5 added. The experimental results suggest that Nb5+ doping does not alter the crystal structure but modifies the particle morphology, yielding radially distributed, elongated, rod-like structures. This morphology effectively mitigates the anisotropic volume changes during cycling, thereby bolstering the material's cyclic stability. The material exhibits a discharge capacity of 224.4 mAh g-1 at 0.1C and 200.3 mAh g-1 at 1C, within a voltage range of 2.7 V-4.5 V. Following 100 cycles at 1C, the capacity retention rate maintains a high level of 92.9%, highlighting the material's remarkable capacity retention and cyclic stability under high-voltage conditions. The enhancement of cyclic stability is primarily due to the synergistic effects caused by Nb5+ doping. Nb5+ modifies the particle morphology, thereby mitigating the formation of microcracks. The formation of high-energy Nb-O bonds prevents oxygen precipitation at high voltages, minimizes the irreversibility of the H2-H3 phase transition, and thereby enhances the stability of the composite material at high voltages.

20.
J Ethnopharmacol ; 328: 118093, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38537842

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Dichroa febrifuga Lour., a toxic but extensively used traditional Chinese medicine with a remarkable effect, is commonly called "Changshan" in China. It has been used to treat malaria and many other parasitic diseases. AIM OF THE REVIEW: The study aims to provide a current overview of the progress in the research on traditional use, phytochemistry, pharmacological activities, toxicology, and methods of toxicity reduction of D. febrifuga. Additionally, further research directions and development prospects for the plant were put forward. MATERIALS AND METHODS: The article uses "Dichroa febrifuga Lour." "D. febrifuga" as the keyword and all relevant information on D. febrifuga was collected from electronic searches (Elsevier, PubMed, ACS, CNKI, Google Scholar, and Baidu Scholar), doctoral and master's dissertations and classic books about Chinese herbs. RESULTS: 30 chemical compounds, including alkaloids, terpenoids, flavonoids and other kinds, were isolated and identified from D. febrifuga. Modern pharmacological studies have shown that these components have a variety of pharmacological activities, including anti-malarial activities, anti-inflammatory activities, anti-tumor activities, anti-parasitic activities and anti-oomycete activities. Meanwhile, alkaloids, as the material basis of its efficacy, are also the source of its toxicity. It can cause multiple organ damage, including liver, kidney and heart, and cause adverse reactions such as nausea and vomiting, abdominal pain and diarrhea. In the current study, the toxicity can be reduced by modifying the structure of the compound, processing and changing the dosage forms. CONCLUSIONS: There are few studies on the chemical constituents of D. febrifuga, so the components and their structure characterization contained in it can become the focus of future research. In view of the toxicity of D. febrifuga, there are many methods to reduce it, but the safety and rationality of these methods need further study.


Assuntos
Etnofarmacologia , Medicina Tradicional Chinesa , Compostos Fitoquímicos , Humanos , Animais , Compostos Fitoquímicos/farmacologia , Compostos Fitoquímicos/toxicidade , Compostos Fitoquímicos/química , Compostos Fitoquímicos/isolamento & purificação , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/toxicidade , Fitoterapia
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa