Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 374
Filtrar
1.
Brain Behav ; 14(5): e3515, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38702895

RESUMO

INTRODUCTION: Maternal sleep deprivation (MSD), which induces inflammation and synaptic dysfunction in the hippocampus, has been associated with learning and memory impairment in offspring. Melatonin (Mel) has been shown to have anti-inflammatory, antioxidant, and neuroprotective function. However, the beneficial effect of Mel on MSD-induced cognitive impairment and its mechanisms are unknown. METHODS: In the present study, adult offspring suffered from MSD were injected with Mel (20 mg/kg) once a day during postnatal days 61-88. The cognitive function was evaluated by the Morris water maze test. Levels of proinflammatory cytokines were examined by enzyme-linked immunosorbent assay. The mRNA and protein levels of synaptic plasticity associated proteins were examined using reverse transcription-polymerase chain reaction and western blotting. RESULTS: The results showed that MSD impaired learning and memory in the offspring mice. MSD increased the levels of interleukin (IL)-1creIL-6, and tumor necrosis factor-α and decreased the expression levels of brain-derived neurotrophic factor, tyrosine kinase receptor B, postsynaptic density protein-95, and synaptophysin in the hippocampus. Furthermore, Mel attenuated cognitive impairment and restored markers of inflammation and synaptic plasticity to control levels. CONCLUSIONS: These findings indicated that Mel could ameliorate learning and memory impairment induced by MSD, and these beneficial effects were related to improvement in inflammation and synaptic dysfunction.


Assuntos
Hipocampo , Melatonina , Transtornos da Memória , Plasticidade Neuronal , Privação do Sono , Animais , Melatonina/farmacologia , Melatonina/administração & dosagem , Privação do Sono/complicações , Privação do Sono/tratamento farmacológico , Privação do Sono/fisiopatologia , Camundongos , Masculino , Hipocampo/metabolismo , Hipocampo/efeitos dos fármacos , Feminino , Transtornos da Memória/tratamento farmacológico , Transtornos da Memória/etiologia , Transtornos da Memória/fisiopatologia , Plasticidade Neuronal/efeitos dos fármacos , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Gravidez , Privação Materna , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/fisiopatologia , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Doenças Neuroinflamatórias/tratamento farmacológico
2.
Cogn Emot ; : 1-18, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38738622

RESUMO

The brain processes underlying the distinction between emotion-label words (e.g. happy, sad) and emotion-laden words (e.g. successful, failed) remain inconclusive in bilingualism research. The present study aims to directly compare the processing of these two types of emotion words in both the first language (L1) and second language (L2) by recording event-related potentials (ERP) from late Chinese-English bilinguals during a lexical decision task. The results revealed that in the early word processing stages, the N170 emotion effect emerged only for L1 negative emotion-laden words and L2 negative emotion-label words. In addition, larger early posterior negativity (EPN) was elicited by emotion-laden words than emotion-label words in both L1 and L2. In the later processing stages, the N400 emotion effect was evident for L1 emotion words, excluding positive emotion-laden words, while it was absent in L2. Notably, L1 emotion words elicited enhanced N400 and attenuated late positive complex (LPC) compared to those in L2. Taken together, these findings confirmed the engagement of emotion, and highlighted the modulation of emotion word type and valence on word processing in both early and late processing stages. Different neural mechanisms between L1 and L2 in processing written emotion words were elucidated.

3.
Nanomaterials (Basel) ; 14(8)2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38668213

RESUMO

Nowadays, metal oxide semiconductor gas sensors have diverse applications ranging from human health to smart agriculture with the development of Internet of Things (IoT) technologies. However, high operating temperatures and an unsatisfactory detection capability (high sensitivity, fast response/recovery speed, etc.) hinder their integration into the IoT. Herein, a ternary heterostructure was prepared by decorating WO3 nanoplates with Au and SnO2 nanoparticles through a facial photochemical deposition method. This was employed as a sensing material for 3-hydroxy-2-butanone (3H-2B), a biomarker of Listeria monocytogenes. These Au/SnO2-WO3 nanoplate-based sensors exhibited an excellent response (Ra/Rg = 662) to 25 ppm 3H-2B, which was 24 times higher than that of pure WO3 nanoplates at 140 °C. Moreover, the 3H-2B sensor showed an ultrafast response and recovery speed to 25 ppm 3H-2B as well as high selectivity. These excellent sensing performances could be attributed to the rich Au/SnO2-WO3 active interfaces and the excellent transport of carriers in nanoplates. Furthermore, a wireless portable gas sensor equipped with the Au/SnO2-WO3 nanoplates was assembled, which was tested using 3H-2B with known concentrations to study the possibilities of real-time gas monitoring in food quality and safety.

4.
Sci Data ; 11(1): 396, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38637640

RESUMO

Stag beetles (Coleoptera: Lucanidae) represent a significant saproxylic assemblage in forest ecosystems and are noted for their enlarged mandibles and male polymorphism. Despite their relevance as ideal models for the study of exaggerated mandibles that aid in attracting mates, the regulatory mechanisms associated with these traits remain understudied, and restricted by the lack of high-quality reference genomes for stag beetles. To address this limitation, we successfully assembled the first chromosome-level genome of a representative species Dorcus hopei. The genome was 496.58 Mb in length, with a scaffold N50 size of 54.61 Mb, BUSCO values of 99.8%, and 96.8% of scaffolds anchored to nine pairs of chromosomes. We identified 285.27 Mb (57.45%) of repeat sequences and annotated 11,231 protein-coding genes. This genome will be a valuable resource for further understanding the evolution and ecology of stag beetles, and provides a basis for studying the mechanisms of exaggerated mandibles through comparative analysis.


Assuntos
Besouros , Genoma de Inseto , Animais , Masculino , Besouros/genética , Florestas , Filogenia , Polimorfismo Genético , Cromossomos de Insetos
5.
Arch Insect Biochem Physiol ; 115(4): e22113, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38628056

RESUMO

The efficiency of RNA interference (RNAi) has always limited the research on the phenotype innovation of Lepidoptera insects. Previous studies have found that double-stranded RNA-degrading enzyme (dsRNase) is an important factor in RNAi efficiency, but there have been no relevant reports in butterflies (Papilionoidea). Papilio xuthus is one of the important models in butterflies with an extensive experimental application value. To explore the effect of dsRNase in the RNAi efficiency on butterflies, six dsRNase genes (PxdsRNase 1-6) were identified in P. xuthus genome, and their dsRNA-degrading activities were subsequently detected by ex vivo assays. The result shows that the dsRNA-degrading ability of gut content (<1 h) was higher than hemolymph content (>12 h). We then investigated the expression patterns of these PxdsRNase genes during different tissues and developmental stages, and related RNAi experiments were carried out. Our results show that different PxdsRNase genes had different expression levels at different developmental stages and tissues. The expression of PxdsRNase2, PxdsRNase3, and PxdsRNase6 were upregulated significantly through dsGFP injection, and PxdsRNase genes can be silenced effectively by injecting their corresponding dsRNA. RNAi-of-RNAi studies with PxEbony, which acts as a reporter gene, observed that silencing PxdsRNase genes can increase RNAi efficiency significantly. These results confirm that silencing dsRNase genes can improve RNAi efficiency in P. xuthus significantly, providing a reference for the functional study of insects such as butterflies with low RNAi efficiency.


Assuntos
Borboletas , Animais , Borboletas/genética , Interferência de RNA , RNA de Cadeia Dupla , Insetos/genética , Inativação Gênica
6.
J Int Med Res ; 52(4): 3000605241240579, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38603605

RESUMO

The mortality rate of gastric varices bleeding can reach 20% within 6 weeks. Isolated gastric varices (IGVs) refer to gastric varices without esophageal varices and typically arise as a common complication of left portal hypertension. Although IGVs commonly form in the setting of splenic vein occlusion, the combination of antiphospholipid syndrome and protein S deficiency leading to splenic vein occlusion is rare. We herein present a case of a 28-year-old woman with intermittent epigastric pain and melena. She was diagnosed with antiphospholipid syndrome based on the triad of pregnancy morbidity, unexplained venous occlusion, and positive lupus anticoagulant. Laparoscopic splenectomy and pericardial devascularization were performed for the treatment of IGVs. During the 6-month postoperative follow-up, repeated endoscopy and contrast-enhanced computed tomography revealed disappearance of the IGVs. This is the first description of splenic vein occlusion associated with both antiphospholipid syndrome and protein S deficiency. We also provide a review of the etiology, clinical manifestations, diagnosis, and treatment methods of IGVs.


Assuntos
Síndrome Antifosfolipídica , Varizes Esofágicas e Gástricas , Deficiência de Proteína S , Doenças Vasculares , Feminino , Humanos , Adulto , Varizes Esofágicas e Gástricas/complicações , Varizes Esofágicas e Gástricas/diagnóstico , Síndrome Antifosfolipídica/complicações , Síndrome Antifosfolipídica/diagnóstico , Deficiência de Proteína S/complicações , Hemorragia Gastrointestinal/etiologia , Doenças Vasculares/complicações
7.
Part Fibre Toxicol ; 21(1): 17, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38561847

RESUMO

BACKGROUND: Amorphous silica nanoparticles (SiNPs) have been gradually proven to threaten cardiac health, but pathogenesis has not been fully elucidated. Ferroptosis is a newly defined form of programmed cell death that is implicated in myocardial diseases. Nevertheless, its role in the adverse cardiac effects of SiNPs has not been described. RESULTS: We first reported the induction of cardiomyocyte ferroptosis by SiNPs in both in vivo and in vitro. The sub-chronic exposure to SiNPs through intratracheal instillation aroused myocardial injury, characterized by significant inflammatory infiltration and collagen hyperplasia, accompanied by elevated CK-MB and cTnT activities in serum. Meanwhile, the activation of myocardial ferroptosis by SiNPs was certified by the extensive iron overload, declined FTH1 and FTL, and lipid peroxidation. The correlation analysis among detected indexes hinted ferroptosis was responsible for the SiNPs-aroused myocardial injury. Further, in vitro tests, SiNPs triggered iron overload and lipid peroxidation in cardiomyocytes. Concomitantly, altered expressions of TfR, DMT1, FTH1, and FTL indicated dysregulated iron metabolism of cardiomyocytes upon SiNP stimuli. Also, shrinking mitochondria with ridge fracture and ruptured outer membrane were noticed. To note, the ferroptosis inhibitor Ferrostatin-1 could effectively alleviate SiNPs-induced iron overload, lipid peroxidation, and myocardial cytotoxicity. More importantly, the mechanistic investigations revealed miR-125b-2-3p-targeted HO-1 as a key player in the induction of ferroptosis by SiNPs, probably through regulating the intracellular iron metabolism to mediate iron overload and ensuing lipid peroxidation. CONCLUSIONS: Our findings firstly underscored the fact that ferroptosis mediated by miR-125b-2-3p/HO-1 signaling was a contributor to SiNPs-induced myocardial injury, which could be of importance to elucidate the toxicity and provide new insights into the future safety applications of SiNPs-related nano products.


Assuntos
Ferroptose , Sobrecarga de Ferro , MicroRNAs , Nanopartículas , Humanos , Miócitos Cardíacos , Dióxido de Silício/metabolismo , Sobrecarga de Ferro/metabolismo , Sobrecarga de Ferro/patologia , Ferro/metabolismo , Ferro/farmacologia , MicroRNAs/metabolismo , Nanopartículas/toxicidade
8.
Brain Behav ; 14(5): e3508, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38688894

RESUMO

BACKGROUND: The inflammation and synaptic dysfunction induced by mitochondrial dysfunction play essential roles in the learning and memory impairment associated with sleep dysfunction. Elamipretide (SS-31), a novel mitochondrion-targeted antioxidant, was proven to improve mitochondrial dysfunction, the inflammatory response, synaptic dysfunction, and cognitive impairment in models of cerebral ischemia, sepsis, and type 2 diabetes. However, the potential for SS-31 to improve the cognitive impairment induced by chronic sleep deprivation (CSD) and its underlying mechanisms is unknown. METHODS: Adult c57BL/6J mice were subjected to CSD for 21 days using an activity wheel accompanied by daily intraperitoneal injection of SS-31 (5 mg/kg). The novel object recognition and Morris water maze test were used to evaluate hippocampus-dependent cognitive function. Western blotting and reverse transcription-quantitative polymerase chain reaction assays were used to determine the effects of CSD and SS-31 on markers of mitochondria, inflammation response, and synaptic function. Enzyme-linked immunosorbent assays were used to examine the levels of proinflammatory cytokines. RESULTS: SS-31 could improve the cognitive impairment induced by CSD. In particular, SS-31 treatment restored the CSD-induced decrease in sirtuin 1 (SIRT1) and peroxisome proliferator-activated receptor γ coactivator alpha levels and the increase in levels nuclear factor kappa-B and inflammatory cytokines, including interleukin (IL)-1ß, IL-6, and tumor necrosis factor-alpha. Furthermore, SS-31 significantly increased the levels of brain-derived neurotrophic factor, postsynaptic density protein-95, and synaptophysin in CSD mice. CONCLUSION: Taken together, these results suggest that SS-31 could improve CSD-induced mitochondrial biogenesis dysfunction, inflammatory response, synaptic dysfunction, and cognitive impairment by increasing SIRT1 expression levels.


Assuntos
Antioxidantes , Camundongos Endogâmicos C57BL , Mitocôndrias , Oligopeptídeos , Privação do Sono , Animais , Camundongos , Privação do Sono/tratamento farmacológico , Privação do Sono/complicações , Privação do Sono/metabolismo , Oligopeptídeos/farmacologia , Oligopeptídeos/administração & dosagem , Masculino , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Antioxidantes/farmacologia , Hipocampo/metabolismo , Hipocampo/efeitos dos fármacos , Transtornos da Memória/tratamento farmacológico , Transtornos da Memória/etiologia , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/etiologia , Sirtuína 1/metabolismo , Modelos Animais de Doenças
9.
Chin Med ; 19(1): 49, 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38519984

RESUMO

Respiratory diseases, marked by structural changes in the airways and lung tissues, can lead to reduced respiratory function and, in severe cases, respiratory failure. The side effects of current treatments, such as hormone therapy, drugs, and radiotherapy, highlight the need for new therapeutic strategies. Traditional Chinese Medicine (TCM) offers a promising alternative, leveraging its ability to target multiple pathways and mechanisms. Active compounds from Chinese herbs and other natural sources exhibit anti-inflammatory, antioxidant, antitumor, and immunomodulatory effects, making them valuable in preventing and treating respiratory conditions. Ferroptosis, a unique form of programmed cell death (PCD) distinct from apoptosis, necrosis, and others, has emerged as a key area of interest. However, comprehensive reviews on how natural products influence ferroptosis in respiratory diseases are lacking. This review will explore the therapeutic potential and mechanisms of natural products from TCM in modulating ferroptosis for respiratory diseases like acute lung injury (ALI), asthma, pulmonary fibrosis (PF), chronic obstructive pulmonary disease (COPD), lung ischemia-reperfusion injury (LIRI), pulmonary hypertension (PH), and lung cancer, aiming to provide new insights for research and clinical application in TCM for respiratory health.

10.
J Biochem Mol Toxicol ; 38(4): e23698, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38501767

RESUMO

Accumulating evidence confirms that sleep insufficiency is a high risk factor for cognitive impairment, which involves inflammation and synaptic dysfunction. Resveratrol, an agonist of the Sirt1, has demonstrated anti-inflammation and neuroprotective effects in models of Alzheimer's disease, Parkinson's disease, and schizophrenia. However, the beneficial effects of resveratrol on sleep deprivation-induced cognitive deficits and its underlying molecular mechanisms are unclear. In the present study, thirty-two male C57BL/6 J mice were randomly divided into a Control+DMSO group, Control+Resveratrol group, SD+DMSO group, and SD+Resveratrol group. The mice in the SD+Resveratrol group underwent 5 days of sleep deprivation after pretreatment with resveratrol (50 mg/kg) for 2 weeks, while the mice in the SD+DMSO group only underwent sleep deprivation. After sleep deprivation, we evaluated spatial learning and memory function using the Morris water maze test. We used general molecular biology techniques to detect changes in levels of pro-inflammatory cytokines and Sirt1/miR-134 pathway-related synaptic plasticity proteins. We found that resveratrol significantly reversed sleep deprivation-induced learning and memory impairment, elevated interleukin-1ß, interleukin-6, and tumor necrosis factor-α levels, and decreased brain-derived neurotrophic factor, tyrosine kinase receptor B, postsynaptic density protein-95, and synaptophysin levels by activating the Sirt1/miR-134 pathway. In conclusion, resveratrol is a promising agent for preventing sleep deprivation-induced cognitive dysfunction by reducing pro-inflammatory cytokines and improving synaptic function via the Sirt1/miR-134 pathway.


Assuntos
Disfunção Cognitiva , MicroRNAs , Masculino , Camundongos , Animais , Resveratrol/farmacologia , Privação do Sono/complicações , Privação do Sono/metabolismo , Sirtuína 1/metabolismo , Dimetil Sulfóxido/metabolismo , Dimetil Sulfóxido/farmacologia , Camundongos Endogâmicos C57BL , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/prevenção & controle , Hipocampo/metabolismo , MicroRNAs/metabolismo , Citocinas/metabolismo , Cognição
11.
Int J Biol Macromol ; 265(Pt 2): 130898, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38508556

RESUMO

Anti-infection hydrogels have recently aroused enormous attraction, particularly in the treatment of chronic wounds. Herein, silver nanoparticle@catechol formaldehyde resin microspheres (Ag@CFRs) were fabricated by one-step hydrothermal method and subsequently encapsulated in hydrogels which were developed by Schiff base reaction between aldehyde groups in oxidized hyaluronic acid and amino groups in carboxymethyl chitosan. The developed polysaccharide hydrogel exhibited microporous structure, high swelling capacity, favorable mechanical strength, enhanced tissue adhesion and photothermal activities. Additionally, the hydrogel not only ensured long-term and high-efficiency antibacterial performance (99.9 %) toward E. coli and S. aureus, but also realized superior cytocompatibility in vitro. Moreover, based on the triple antibacterial strategies endowed by chitosan, silver nanoparticles and the photothermal properties of catechol microspheres, the composite hydrogel exhibited excellent anti-infection function, significantly downregulated inflammatory factors (TNF-α and IL-1ß) and promoted in vivo infected-wound healing. These results demonstrated that the polysaccharide hydrogel containing Ag@CFRs has great potential for infected-wounds repair.


Assuntos
Quitosana , Nanopartículas Metálicas , Hidrogéis/farmacologia , Prata , Escherichia coli , Microesferas , Staphylococcus aureus , Antibacterianos/farmacologia , Catecóis/farmacologia , Anti-Inflamatórios , Polissacarídeos/farmacologia
12.
Sleep Med ; 117: 162-168, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38547593

RESUMO

BACKGROUND AND OBJECTIVE: Rumination, a common factor of chronic insomnia disorder (CID) caused by cognitive-emotional arousal, is associated with an increased amount of rapid eye movement (REM) sleep. However, the specific subtypes, such as phasic REM and tonic REM, that contribute to the increased REM sleep have not been reported. This study aimed to determine the association between rumination and different REM sleep subtypes in patients with CID. METHODS: This study enrolled 35 patients with CID and 27 age- and sex-matched healthy controls. The Immersion-Rumination Questionnaire evaluated participants' rumination, and the Insomnia Severity Index was used to assess insomnia severity. Finally, polysomnography was used to monitor objective sleep quality and quantification of different types of REM. RESULTS: The CID patients had higher rumination scores than the healthy controls. They had a shorter REM sleep duration, less phasic REM, a lower percentage of phasic REM time, and a higher percentage of tonic REM time. Spectral analysis revealed that the patients affected by insomnia had higher ß power during REM sleep, higher ß and σ power during phasic REM sleep, and higher ß, and γ power during tonic REM sleep. Partial correlation analysis showed that rumination in the CID patients correlated negatively with the duration of phasic REM sleep. Additionally, rumination correlated negatively with δ power in REM sleep and positively with ß power in REM sleep, tonic REM sleep, phasic REM sleep, N3and N2 sleep in the patients with CID. CONCLUSION: The CID patients had stronger rumination, reduced total and phasic REM sleep, and the stronger rumination was, the shorter phasic REM was and the higher fast (ß) wave power in REM sleep.


Assuntos
Transtorno do Comportamento do Sono REM , Distúrbios do Início e da Manutenção do Sono , Humanos , Sono REM , Distúrbios do Início e da Manutenção do Sono/complicações , Polissonografia , Nível de Alerta , Transtorno do Comportamento do Sono REM/complicações
13.
Sleep Med ; 117: 177-183, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38554533

RESUMO

OBJECTIVES: To explore the relationship between nocturnal levels of stress-related hormones and different sleep-wake states in chronic insomnia disorder (CID) patients. METHODS: Thirty-three CID patients and 34 good sleepers were enrolled and completed assessment of sleep log, Pittsburgh Sleep Quality Index and Insomnia Severity Index. During a-overnight polysomnography monitoring, the patients' vein bleeds were continually collected at different time points (pre-sleep, deep-sleep, 5-min or 30-min waking, and morning waking-up). The control subjects' bleeds were collected only at 22:00 and morning waking-up. The serum hormones were detected using enzyme-linked immunosorbent assay. RESULTS: Compared with at pre-sleep, the level of cortisol was significantly higher at morning waking-up respectively in two-group subjects (Ps < 0.001), with insignificant inter-group differences in cortisol, corticotropin releasing hormone and copeptin at the two time-points. In the patients, the nocturnal secretion curves of three hormones were similar, with the highest concentration at morning waking-up, followed by 30-min waking, 5-min waking, pre-sleep, and deep-sleep. The patients' cortisol (Z = 79.192, P < 0.001) and copeptin (Z = 12.333, P = 0.015) levels were statistically different at different time-points, with higher cortisol at morning waking-up relative to deep-sleep, pre-sleep and 5-min waking (Ps < 0.05), and at 30-min waking relative to deep-sleep and pre-sleep (Ps < 0.05), and higher copeptin at morning waking-up relative to deep-sleep (P < 0.05). CONCLUSIONS: In CID, the nocturnal wakes were instantaneously accompanied by high level, and deep sleep was accompanied by the lowest levels, of stress-related hormones, especially in cortisol, supporting the insomniac hypothesis of increased nocturnal pulse-release of cortisol.


Assuntos
Distúrbios do Início e da Manutenção do Sono , Humanos , Projetos Piloto , Hidrocortisona , Sono , Polissonografia
14.
Photochem Photobiol Sci ; 23(4): 719-729, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38441849

RESUMO

The bioluminescence system of luminescent beetles has extensive applications in biological imaging, protein labeling and drug screening. To explore wild luciferases with excellent catalytic activity and thermal stability, we cloned the luciferase of Pygoluciola qingyu, one species living in areas of high temperature and with strong bioluminescence, by combining transcriptomic sequencing and reverse transcription polymerase chain reaction (RT-PCR). The total length of luciferase gene is 1638 bp and the luciferase consists 544 amino acids. The recombinant P. qingyu luciferase was produced in vitro and its characteristics were compared with those of eight luciferases from China firefly species and two commercial luciferases. Compared with these luciferases, the P. qingyu luciferase shows the highest luminescence activity at room temperature (about 25-28 â„ƒ) with similar KM value for D-luciferin and ATP to the Photinus pyralis luciferase. The P. qingyu luciferase activity was highest at 35 â„ƒ and can keep high activity at 30-40 â„ƒ, which suggests the potential of P. qingyu luciferase for in vivo and cell application. Our results provide new insights into P. qingyu luciferase and give a new resource for the application of luciferases.


Assuntos
Besouros , Vaga-Lumes , Animais , Vaga-Lumes/genética , Besouros/genética , Besouros/metabolismo , Sequência de Aminoácidos , Luciferases/química , Luciferases de Vaga-Lume/metabolismo , Clonagem Molecular , Medições Luminescentes
15.
Opt Express ; 32(4): 6531-6539, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38439353

RESUMO

Graphene oxide (GO) flat lens has a thickness in nanoscale. They modulates the light field via both phase and amplitude modulation and hence possess excellent focusing property. In this paper, we develop a systematic design method to realize the ultrathin GO flat lens with various focusing properties. By using the Rayleigh-Sommerfield theory, the focusing property of ultrathin GO lenses is accurately calculated, then the genetic algorithm (GA) is employed to design the GO lenses. The lens works at visible frequency can have a large radius and long working distance. By setting different optimization objectives, extraordinary focusing property including sub-diffraction limit focusing with FWHM (∼1.96λ) and achromatic focusing with the wavelengths (450 nm, 550 nm, 650 nm) can be achieved. These innovative designs are fabricated and tested.

16.
Small ; : e2400615, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38477702

RESUMO

Despite the intriguing potential, nano-socketed Cu/perovskite heterostructures for CO2 electroreduction (CO2 RR) are still in their infancy and rational optimization of their CO2 RR properties is lacking. Here, an effective strategy is reported to promote CO2 -to-C2+ conversion over nano-socketed Cu/perovskite heterostructures by A-site-valence-controlled oxygen vacancies. For the proof-of-concept catalysts of Cu/La0.3-x Sr0.6+x TiO3-δ (x from 0 to 0.3), their oxygen vacancy concentrations increase controllably with the decreased A-site valences (or the increased x values). In flow cells, their activity and selectivity for C2+ present positive correlations with the oxygen vacancy concentrations. Among them, the Cu/Sr0.9 TiO3-δ with most oxygen vacancies shows the optimal activity and selectivity for C2+ . And relative to the Cu/La0.3 Sr0.6 TiO3-δ with minimum oxygen vacancies, the Cu/Sr0.9 TiO3-δ exhibits marked improvements (up to 2.4 folds) in activity and selectivity for C2+ . The experiments and theoretical calculations suggest that the optimized performance can be attributed to the merits provided by oxygen vacancies, including the accelerated charge transfer, enhanced adsorption/activation of reaction species, and reduced energy barrier for C─C coupling. Moreover, when explored in a membrane-electrode assembly electrolyzer, the Cu/Sr0.9 TiO3-δ catalyst shows excellent activity, selectivity (43.9%), and stability for C2 H4 at industrial current densities, being the most effective perovskite-based catalyst for CO2 -to-C2 H4 conversion.

17.
Front Psychol ; 15: 1294982, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38333062

RESUMO

Background: Postdoctoral researchers are critical to scholarly advancements, and promoting postdoctoral career growth is an endogenous path to help postdocs break through the "encircled city of scientific research". However, further research is needed to fully explore the mechanisms that connect workplace support to postdoctoral career growth. Methods: Drawing from the Conservation of Resources theory, this study proposes a chain mediation model that demonstrates how workplace support enhances career growth by connecting psychological capital with work-life balance. To understand the motivation and career growth of postdocs in China, we conducted two questionnaires in 2021 and 2023 with the support of relevant stations. Results: Analyzing 367 questionnaires from Chinese postdocs, our research indicates that workplace support has a positive impact on career growth. Additionally, both psychological capital and work-life balance are key factors that contribute to career growth, serving as separate mediators and as part of a chain of mediators. Discussion: This study validates the appropriateness of the Conservation of Resources theory in the study of the influence mechanism of postdoctoral career growth and proposes targeted strategies for academic institutions to improve support systems, promoting more effective career development pathways.

18.
Cell Stem Cell ; 31(2): 260-274.e7, 2024 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-38306994

RESUMO

Probing how human neural networks operate is hindered by the lack of reliable human neural tissues amenable to the dynamic functional assessment of neural circuits. We developed a 3D bioprinting platform to assemble tissues with defined human neural cell types in a desired dimension using a commercial bioprinter. The printed neuronal progenitors differentiate into neurons and form functional neural circuits within and between tissue layers with specificity within weeks, evidenced by the cortical-to-striatal projection, spontaneous synaptic currents, and synaptic response to neuronal excitation. Printed astrocyte progenitors develop into mature astrocytes with elaborated processes and form functional neuron-astrocyte networks, indicated by calcium flux and glutamate uptake in response to neuronal excitation under physiological and pathological conditions. These designed human neural tissues will likely be useful for understanding the wiring of human neural networks, modeling pathological processes, and serving as platforms for drug testing.


Assuntos
Bioimpressão , Tecido Nervoso , Humanos , Neurônios/metabolismo , Astrócitos/metabolismo , Engenharia Tecidual
19.
bioRxiv ; 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38328181

RESUMO

Probing how the human neural networks operate is hindered by the lack of reliable human neural tissues amenable for dynamic functional assessment of neural circuits. We developed a 3D bioprinting platform to assemble tissues with defined human neural cell types in a desired dimension using a commercial bioprinter. The printed neuronal progenitors differentiate to neurons and form functional neural circuits in and between tissue layers with specificity within weeks, evidenced by the cortical-to-striatal projection, spontaneous synaptic currents and synaptic response to neuronal excitation. Printed astrocyte progenitors develop into mature astrocytes with elaborated processes and form functional neuron-astrocyte networks, indicated by calcium flux and glutamate uptake in response to neuronal excitation under physiological and pathological conditions. These designed human neural tissues will likely be useful for understanding the wiring of human neural networks, modeling pathological processes, and serving as platforms for drug testing.

20.
Angew Chem Int Ed Engl ; 63(16): e202401570, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38380578

RESUMO

1,2-migration is one recurring isomerization reaction in organic chemistry. In contrast, double 1,2-migration remains rare and limited to transition-metal complexes. Herein, we describe the synthesis, characterization and reactivity of mixed heavier Sn=Ge vinylidenes. Double 1,2-carbon migration enables the isomerization of the stannagermenylidene (3) to the germastannenylidene (4). X-ray diffraction analysis and DFT calculations revealed that 3 and 4 feature a Sn=Ge double bond. The reaction of 3 with IMe4 (1,3,4,5-tetramethylimidazoline-2-ylidene) results in the electron redistribution in the Sn=Ge core to give the germylone-stannylene adduct (5). Moreover, treatment of 3 with 0.25 equiv. of (AlCp*)4 produces the heteronuclear aluminyl stannagermyne (6).

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA