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1.
J Neurosci ; 44(2)2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-37973375

RESUMO

Cortical neurons exhibit multiple timescales related to dynamics of spontaneous fluctuations (intrinsic timescales) and response to task events (seasonal timescales) in addition to selectivity to task-relevant signals. These timescales increase systematically across the cortical hierarchy, for example, from parietal to prefrontal and cingulate cortex, pointing to their role in cortical computations. It is currently unknown whether these timescales are inherent properties of neurons and/or depend on training in a specific task and if the latter, how their modulations contribute to task performance. To address these questions, we analyzed single-cell recordings within five subregions of the prefrontal cortex (PFC) of male macaques before and after training on a working-memory task. We found fine-grained but opposite gradients of intrinsic and seasonal timescales that mainly appeared after training. Intrinsic timescales decreased whereas seasonal timescales increased from posterior to anterior subregions within both dorsal and ventral PFC. Moreover, training was accompanied by increases in proportions of neurons that exhibited intrinsic and seasonal timescales. These effects were comparable to the emergence of response selectivity due to training. Finally, task selectivity accompanied opposite neural dynamics such that neurons with task-relevant selectivity exhibited longer intrinsic and shorter seasonal timescales. Notably, neurons with longer intrinsic and shorter seasonal timescales exhibited superior population-level coding, but these advantages extended to the delay period mainly after training. Together, our results provide evidence for plastic, fine-grained gradients of timescales within PFC that can influence both single-cell and population coding, pointing to the importance of these timescales in understanding cognition.


Assuntos
Memória de Curto Prazo , Córtex Pré-Frontal , Animais , Masculino , Memória de Curto Prazo/fisiologia , Córtex Pré-Frontal/fisiologia , Macaca , Neurônios/fisiologia , Primatas
2.
J Neurosci ; 44(23)2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38641409

RESUMO

The behavioral and neural effects of the endogenous release of acetylcholine following stimulation of the nucleus basalis (NB) of Meynert have been recently examined in two male monkeys (Qi et al., 2021). Counterintuitively, NB stimulation enhanced behavioral performance while broadening neural tuning in the prefrontal cortex (PFC). The mechanism by which a weaker mnemonic neural code could lead to better performance remains unclear. Here, we show that increased neural excitability in a simple continuous bump attractor model can induce broader neural tuning and decrease bump diffusion, provided neural rates are saturated. Increased memory precision in the model overrides memory accuracy, improving overall task performance. Moreover, we show that bump attractor dynamics can account for the nonuniform impact of neuromodulation on distractibility, depending on distractor distance from the target. Finally, we delve into the conditions under which bump attractor tuning and diffusion balance in biologically plausible heterogeneous network models. In these discrete bump attractor networks, we show that reducing spatial correlations or enhancing excitatory transmission can improve memory precision. Altogether, we provide a mechanistic understanding of how cholinergic neuromodulation controls spatial working memory through perturbed attractor dynamics in the PFC.


Assuntos
Memória de Curto Prazo , Modelos Neurológicos , Córtex Pré-Frontal , Memória Espacial , Córtex Pré-Frontal/fisiologia , Memória de Curto Prazo/fisiologia , Memória Espacial/fisiologia , Animais , Acetilcolina/metabolismo , Masculino , Neurônios Colinérgicos/fisiologia , Neurônios Colinérgicos/efeitos dos fármacos , Núcleo Basal de Meynert/fisiologia
3.
Neurochem Res ; 49(7): 1806-1822, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38713437

RESUMO

Ischemic stroke presents a global health challenge, necessitating an in-depth comprehension of its pathophysiology and therapeutic strategies. While reperfusion therapy salvages brain tissue, it also triggers detrimental cerebral ischemia-reperfusion injury (CIRI). In our investigation, we observed the activation of nuclear receptor coactivator 4 (NCOA4)-mediated ferritinophagy in an oxygen-glucose deprivation/reoxygenation (OGD/R) model using HT22 cells (P < 0.05). This activation contributed to oxidative stress (P < 0.05), enhanced autophagy (P < 0.05) and cell death (P < 0.05) during CIRI. Silencing NCOA4 effectively mitigated OGD/R-induced damage (P < 0.05). These findings suggested that targeting NCOA4-mediated ferritinophagy held promise for preventing and treating CIRI. Subsequently, we substantiated the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway effectively regulated the NCOA4-mediated ferritinophagy, by applying the cGAS inhibitor RU.521 and performing NCOA4 overexpression (P < 0.05). Suppressing the cGAS-STING pathway efficiently curtailed ferritinophagy (P < 0.05), oxidative stress (P < 0.05), and cell damage (P < 0.05) of CIRI, while NCOA4 overexpression could alleviate this effect (P < 0.05). Finally, we elucidated the specific molecular mechanism underlying the protective effect of the iron chelator deferoxamine (DFO) on CIRI. Our findings revealed that DFO alleviated hypoxia-reoxygenation injury in HT22 cells through inhibiting NCOA4-mediated ferritinophagy and reducing ferrous ion levels (P < 0.05). However, the protective effects of DFO were counteracted by cGAS overexpression (P < 0.05). In summary, our results indicated that the activation of the cGAS-STING pathway intensified cerebral damage during CIRI by inducing NCOA4-mediated ferritinophagy. Administering the iron chelator DFO effectively attenuated NCOA4-induced ferritinophagy, thereby alleviating CIRI. Nevertheless, the role of the cGAS-STING pathway in CIRI regulation likely involves intricate mechanisms, necessitating further validation in subsequent investigations.


Assuntos
Autofagia , Ferritinas , Coativadores de Receptor Nuclear , Traumatismo por Reperfusão , Coativadores de Receptor Nuclear/metabolismo , Animais , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/tratamento farmacológico , Ferritinas/metabolismo , Camundongos , Autofagia/efeitos dos fármacos , Autofagia/fisiologia , Linhagem Celular , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Isquemia Encefálica/metabolismo , Isquemia Encefálica/tratamento farmacológico
4.
Ann Intern Med ; 176(7): 922-933, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37335994

RESUMO

BACKGROUND: An effective and safe treatment for nausea and vomiting of pregnancy (NVP) is lacking. OBJECTIVE: To assess the efficacy and safety of acupuncture, doxylamine-pyridoxine, and a combination of both in women with moderate to severe NVP. DESIGN: Multicenter, randomized, double-blind, placebo-controlled, 2 × 2 factorial trial. (ClinicalTrials.gov: NCT04401384). SETTING: 13 tertiary hospitals in mainland China from 21 June 2020 to 2 February 2022. PARTICIPANTS: 352 women in early pregnancy with moderate to severe NVP. INTERVENTION: Participants received daily active or sham acupuncture for 30 minutes and doxylamine-pyridoxine or placebo for 14 days. MEASUREMENTS: The primary outcome was the reduction in Pregnancy-Unique Quantification of Emesis (PUQE) score at the end of the intervention at day 15 relative to baseline. Secondary outcomes included quality of life, adverse events, and maternal and perinatal complications. RESULTS: No significant interaction was detected between the interventions (P = 0.69). Participants receiving acupuncture (mean difference [MD], -0.7 [95% CI, -1.3 to -0.1]), doxylamine-pyridoxine (MD, -1.0 [CI, -1.6 to -0.4]), and the combination of both (MD, -1.6 [CI, -2.2 to -0.9]) had a larger reduction in PUQE score over the treatment course than their respective control groups (sham acupuncture, placebo, and sham acupuncture plus placebo). Compared with placebo, a higher risk for births with children who were small for gestational age was observed with doxylamine-pyridoxine (odds ratio, 3.8 [CI, 1.0 to 14.1]). LIMITATION: The placebo effects of the interventions and natural regression of the disease were not evaluated. CONCLUSION: Both acupuncture and doxylamine-pyridoxine alone are efficacious for moderate and severe NVP. However, the clinical importance of this effect is uncertain because of its modest magnitude. The combination of acupuncture and doxylamine-pyridoxine may yield a potentially larger benefit than each treatment alone. PRIMARY FUNDING SOURCE: The National Key R&D Program of China and the Project of Heilongjiang Province "TouYan" Innovation Team.


Assuntos
Terapia por Acupuntura , Antieméticos , Complicações na Gravidez , Gravidez , Criança , Feminino , Humanos , Doxilamina/efeitos adversos , Piridoxina/uso terapêutico , Piridoxina/efeitos adversos , Antieméticos/uso terapêutico , Qualidade de Vida , Vômito/tratamento farmacológico , Vômito/induzido quimicamente , Náusea/tratamento farmacológico , Complicações na Gravidez/tratamento farmacológico , Terapia por Acupuntura/efeitos adversos
5.
BMC Biol ; 21(1): 208, 2023 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-37798721

RESUMO

BACKGROUND: Domestication and introduction of dairy animals facilitated the permanent human occupation of the Tibetan Plateau. Yet the history of dairy pastoralism in the Tibetan Plateau remains poorly understood. Little is known how Tibetans adapted to milk and dairy products. RESULTS: We integrated archeological evidence and genetic analysis to show the picture that the dairy ruminants, together with dogs, were introduced from West Eurasia into the Tibetan Plateau since ~ 3600 years ago. The genetic admixture between the exotic and indigenous dogs enriched the candidate lactase persistence (LP) allele 10974A > G of West Eurasian origin in Tibetan dogs. In vitro experiments demonstrate that - 13838G > A functions as a LP allele in Tibetans. Unlike multiple LP alleles presenting selective signatures in West Eurasians and South Asians, the de novo origin of Tibetan-specific LP allele - 13838G > A with low frequency (~ 6-7%) and absence of selection corresponds - 13910C > T in pastoralists across eastern Eurasia steppe. CONCLUSIONS: Results depict a novel scenario of genetic and cultural adaptations to diet and expand current understanding of the establishment of dairy pastoralism in the Tibetan Plateau.


Assuntos
Criação de Animais Domésticos , Povo Asiático , Dieta , Leite , Animais , Cães/genética , Humanos , Tibet , Ruminantes
6.
Int J Mol Sci ; 25(11)2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38892338

RESUMO

The elongation of the mesocotyl plays an important role in the emergence of maize deep-sowing seeds. This study was designed to explore the function of exogenous salicylic acid (SA) and 6-benzylaminopurine (6-BA) in the growth of the maize mesocotyl and to examine its regulatory network. The results showed that the addition of 0.25 mmol/L exogenous SA promoted the elongation of maize mesocotyls under both 3 cm and 15 cm deep-sowing conditions. Conversely, the addition of 10 mg/L exogenous 6-BA inhibited the elongation of maize mesocotyls. Interestingly, the combined treatment of exogenous SA-6-BA also inhibited the elongation of maize mesocotyls. The longitudinal elongation of mesocotyl cells was the main reason affecting the elongation of maize mesocotyls. Transcriptome analysis showed that exogenous SA and 6-BA may interact in the hormone signaling regulatory network of mesocotyl elongation. The differential expression of genes related to auxin (IAA), jasmonic acid (JA), brassinosteroid (BR), cytokinin (CTK) and SA signaling pathways may be related to the regulation of exogenous SA and 6-BA on the growth of mesocotyls. In addition, five candidate genes that may regulate the length of mesocotyls were screened by Weighted Gene Co-Expression Network Analysis (WGCNA). These genes may be involved in the growth of maize mesocotyls through auxin-activated signaling pathways, transmembrane transport, methylation and redox processes. The results enhance our understanding of the plant hormone regulation of mesocotyl growth, which will help to further explore and identify the key genes affecting mesocotyl growth in plant hormone signaling regulatory networks.


Assuntos
Compostos de Benzil , Regulação da Expressão Gênica de Plantas , Reguladores de Crescimento de Plantas , Purinas , Ácido Salicílico , Zea mays , Zea mays/crescimento & desenvolvimento , Zea mays/efeitos dos fármacos , Zea mays/genética , Zea mays/metabolismo , Ácido Salicílico/farmacologia , Ácido Salicílico/metabolismo , Purinas/farmacologia , Compostos de Benzil/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Reguladores de Crescimento de Plantas/farmacologia , Reguladores de Crescimento de Plantas/metabolismo , Oxilipinas/farmacologia , Citocininas/metabolismo , Citocininas/farmacologia , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Sementes/genética , Perfilação da Expressão Gênica , Transdução de Sinais/efeitos dos fármacos , Ácidos Indolacéticos/farmacologia , Ácidos Indolacéticos/metabolismo , Ciclopentanos/farmacologia
7.
Biochem Biophys Res Commun ; 681: 55-61, 2023 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-37757667

RESUMO

Gelsemium elegans (G.elegans) is a plant of the Loganiaceae family, known for its indole alkaloids, including gelsemine, koumine, and gelsenicine. Gelsemine and koumine are well-studied active alkaloids with low toxicity, valued for their anti-anxiety and analgesic properties. However, gelsenicine, another important alkaloid, remains underexplored due to its high toxicity. This study focuses on evaluating the analgesic properties of gelsenicine and comparing them with gelsemine and koumine. The results indicate that all three alkaloids exhibit robust analgesic properties, with gelsemine, koumine, and gelsenicine showing ED50 values of 0.82 mg/kg, 0.60 mg/kg, and 8.43 µg/kg, respectively, as assessed by the hot plate method. Notably, the therapeutic dose of gelsenicine was significantly lower than its toxic dose (LD50 = 0.185 mg/kg). The study also investigated the mechanism of action by analyzing the expression levels of GlyRα3 and Gephyrin. The PGE2 model group showed decreased expression levels of GlyRα3 and Gephyrin, while groups treated with gelsemine, koumine, and gelsenicine were able to reverse this decrease. These results suggest that gelsenicine effectively alleviates PGE2-induced hyperalgesia by upregulating the expression of GlyRα3 and Gephyrin, which are key targets of the Gly receptor pathway.

8.
Opt Express ; 31(19): 30911-30920, 2023 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-37710623

RESUMO

In this work, we demonstrate the optical heating modulation of soliton-based supercontinuum generation through the employment of multi-walled carbon nanotubes (MW-CNTs) acting as fast and efficient heat generators. By utilizing highly dispersion-sensitive liquid-core fibers in combination with MW-CNTs coated to the outer wall of the fiber, spectral tuning of dispersive waves with response times below one second via exploiting the strong thermo-optic response of the core liquid was achieved. Local illumination of the MW-CNTs coated fiber at selected points allowed modulation of the waveguide dispersion, thus controlling the soliton fission process. Experimentally, a spectral shift of the two dispersive waves towards the region of anomalous dispersion was observed at increasing temperatures. The presented tuning concept shows great potential in the context of nonlinear photonics, as complex and dynamically reconfigurable dispersion profiles can be generated by using structured light fields. This allows investigating nonlinear frequency conversion processes under unconventional conditions, and realizing nonlinear light sources that are reconfigurable quickly.

9.
Pharmacol Res ; 187: 106606, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36516884

RESUMO

Epidermal growth factor receptor variant III (EGFRvIII) is a mutant isoform of EGFR with a deletion of exons 2-7 making it insensitive to EGF stimulation and downstream signal constitutive activation. However, the mechanism underlying the stability of EGFRvIII remains unclear. Based on CRISPR-Cas9 library screening, we found that mucin1 (MUC1) is essential for EGFRvIII glioma cell survival and temozolomide (TMZ) resistance. We revealed that MUC1-C was upregulated in EGFRvIII-positive cells, where it enhanced the stability of EGFRvIII. Knockdown of MUC1-C increased the colocalization of EGFRvIII and lysosomes. Upregulation of MUC1 occurred in an NF-κB dependent manner, and inhibition of the NF-κB pathway could interrupt the EGFRvIII-MUC1 feedback loop by inhibiting MUC1-C. In a previous report, we identified AC1Q3QWB (AQB), a small molecule that could inhibit the phosphorylation of NF-κB. By screening the structural analogs of AQB, we obtained EPIC-1027, which could inhibit the NF-κB pathway more effectively. EPIC-1027 disrupted the EGFRvIII-MUC1-C positive feedback loop in vitro and in vivo, inhibited glioma progression, and promoted sensitization to TMZ. In conclusion, we revealed the pivotal role of MUC1-C in stabilizing EGFRvIII in glioblastoma (GBM) and identified a small molecule, EPIC-1027, with great potential in GBM treatment.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Glioma , Humanos , Temozolomida/farmacologia , Glioblastoma/tratamento farmacológico , Glioblastoma/genética , Glioblastoma/metabolismo , NF-kappa B/metabolismo , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Linhagem Celular Tumoral , Mucina-1/genética
10.
Cell Biol Toxicol ; 39(6): 3175-3195, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37721623

RESUMO

Metabolic dysfunction associated with fatty liver disease (MAFLD), always accompanied by disturbance of glucose and lipid metabolism, is becoming the most difficult obstacle in the next decades. In the current research, we uncover that the potent non-coding RNA Tug1, which is related to metabolic enzymes, regulates hepatocytes steatosis induced by sodium palmitate via miR-1934-3p absorbing. The knockdown of lncRNA-Tug1 distinctly rescues the increased expression level of glycolytic enzymes and fatty acid synthetase via releasing more mature miR-1934-3p in hepatocytes. Moreover, miR-1934-3p suppresses Selenoprotein F (SelenoF) through binding with the SelenoF 3'UTR effectors; importantly, we demonstrated that the deletion of SelenoF consistent with the lncRNA-Tug1's effecting on metabolism enzymes. In the current paper, the interaction of Tug1/miR-1934-3p/SelenoF was verified by the dual-luciferase reporter system, and IRS1/AKT pathway possesses the essential role in glucolipid metabolism when SelenoF is deleted. We concluded that lncRNA Tug1 functioned as ceRNA to alleviate steatosis and glycolysis in hepatocytes of C57BL/6 through adsorbing miR-1934-3p to release SelenoF and triggering IRS/AKT pathway. The Tug1/miR-1934-3p/SelenoF constructed the ceRNA interact network Selenoprotein F accelerates glucolipid metabolism via IRS1/AKT pathway SelenoF-/- alleviates steatosis in mice liver.


Assuntos
Fígado Gorduroso , MicroRNAs , RNA Longo não Codificante , Camundongos , Animais , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Camundongos Endogâmicos C57BL , Fígado Gorduroso/genética , Hepatócitos/metabolismo , Selenoproteínas , Proliferação de Células/genética
11.
Environ Sci Technol ; 57(43): 16585-16594, 2023 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-37842981

RESUMO

A trophic position (TP) model (TPmix model) that simultaneously considered trophic discrimination factor and ßGlu/Phe variations was developed in this study and was first applied to investigate the trophic transfer of halogenated organic pollutants (HOPs) in wetland food webs. The TPmix model characterized the structure of the wetland food web more accurately and significantly improved the reliability of TMF compared to the TPbulk, TPAAs, and TPsimmr models, which were calculated based on the methods of stable nitrogen isotope analysis of bulk, traditional AAs-N-CSIA, and weighted ßGlu/Phe, respectively. Food source analysis revealed three interlocking food webs (kingfisher, crab, and frogs) in this wetland. The highest HOP biomagnification capacities (TMFmix) were found in the kingfisher food web (0.24-82.0), followed by the frog (0.08-34.0) and crab (0.56-11.7) food webs. The parabolic trends of TMFmix across combinations of log KOW in the frog food web were distinct from those of aquatic food webs (kingfisher and crab), which may be related to differences in food web composition and HOP bioaccumulation behaviors between aquatic and terrestrial organisms. This study provides a new tool to accurately study the trophic transfer of contaminants in wetlands and terrestrial food webs with diverse species and complex feeding relationships.


Assuntos
Poluentes Ambientais , Poluentes Químicos da Água , Animais , Cadeia Alimentar , Isótopos de Nitrogênio/análise , Isótopos de Nitrogênio/metabolismo , Áreas Alagadas , Aminoácidos/metabolismo , Reprodutibilidade dos Testes , Peixes/metabolismo , Poluentes Químicos da Água/análise , Monitoramento Ambiental/métodos
12.
Environ Res ; 237(Pt 1): 116962, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37619634

RESUMO

It is of great significance to develop the effective technique to treat phenol-containing wastewater. Herein, Fe-based prussian blue analogues-derived zero valent iron (ZVI) was successfully synthesized by one-step calcination method. Owing to high specific surface area and rich active sites, ZVI-2 possessed excellent performance in charge transfer. Notably, in comparison with conventional ZVI and Fe2+, ZVI-2 can effectively activate peroxymonosulfate (PMS) for achieving rapid degradation of phenol, and the highest removal efficiency of phenol reached 94.9% within 24 min. More importantly, developed ZVI-2/PMS oxidation system with good stability displayed strong anti-interference capability. Interestingly, Fe0 loaded on the surface of ZVI-2 can efficiently break the O-O bond of PMS to generate reactive oxygen species (i.e., SO4•-, OH•, O2•- and 1O2). As main adsorption sites of PMS, the existence of oxygen vacancy promote the formation of high-valent transition metal complexes (namely ZVI-2≡Fe4+=O). Under the combined action of reactive oxygen species and ZVI-2≡Fe4+=O, phenol can be eventually degraded into CO2 and H2O. The possible degradation pathways of phenol were also investigated. Furthermore, proposed ZVI-2/PMS oxidation system displayed great potential for application in the field of wastewater treatment. All in all, current work provided a valuable reference for design and application of Fe-based catalysts in PS-AOPs.

13.
Med Sci Monit ; 29: e940247, 2023 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-37408302

RESUMO

BACKGROUND Thoracic paravertebral block (TPVB) and erector spinae plane block (ESPB) are widely used in video-assisted thoracic surgery (VATS). However, they have corresponding adverse effects, including hypotension for TPVB and unpredictable injectate spread in ESPB. An optimal perioperative analgesic strategy remains controversial. We investigated the effect of ultrasound-guided combined TPVB and ESPB (CTEB) for VATS. MATERIAL AND METHODS A total of 120 patients scheduled for thoracic surgery were randomized to receive either ultrasound-guided TPVB, ESPB, or CTEB preoperatively. Postoperative analgesia was achieved with sufentanil patient-controlled intravenous analgesia. The primary outcome was the static pain score at 2 h after surgery. RESULTS The static pain score 2 h postoperatively was significantly different among the 3 groups. This difference was statistically significant for Group ESPB vs Group TPVB (P=0.004), but not for Group ESPB vs Group CTEB (P=0.767), or Group TPVB vs Group CTEB (P=0.117). Group TPVB exhibited the highest incidence of hypotension among the 3 groups. More patients experienced a sensory loss in Groups TPVB and CTEB 30 min after the block performance. Patients receiving CTEB exhibited a lower incidence of chronic pain 6 months postoperatively than those in Group ESPB. CONCLUSIONS CTEB does not enhance the analgesic effect of ESPB in patients undergoing VATS; however, it may induce a faster sensory loss after nerve block and reduce the incidence of postoperative chronic pain compared with ESPB. CTEB may also help to reduce the incidence of intraoperative hypotension compared with TPVB.


Assuntos
Dor Crônica , Hipotensão , Bloqueio Nervoso , Humanos , Cirurgia Torácica Vídeoassistida , Estudos Prospectivos , Analgésicos , Dor Pós-Operatória/tratamento farmacológico , Dor Pós-Operatória/prevenção & controle
14.
Appl Opt ; 62(13): 3347-3356, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-37132835

RESUMO

The coefficient of thermal expansion (CTE) of ultra-low-expansion (ULE) glass is critical to the development of precision optical systems. Herein, an ultrasonic immersion pulse-reflection method is proposed to characterize the CTE of ULE glass. The ultrasonic longitudinal wave velocity of ULE-glass samples with significantly different CTE values was measured using a correlation algorithm combined with moving-average filtering, which can achieve 0.2 m/s precision with a contribution to the ultrasonic CTE measurement uncertainty of 0.47 ppb/°C. Furthermore, the established ultrasonic CTE measurement model predicted the 5°C-35°C mean CTE with a root-mean-square error of 0.9 ppb/°C. Notably, a complete uncertainty analysis methodology was established in this paper, which can provide directional guidance for the subsequent development of higher-performance measurement devices and the improvement of relevant signal processing procedures.

15.
Ecotoxicol Environ Saf ; 264: 115465, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37716073

RESUMO

A systematic assessment of the variations in the ecological risk of PAHs and the key emission sources controlling the variations is of great importance to human health and aquatic organisms. PAH concentrations, composition, source, and ecological risk in soils and water in two different periods (2010-2011 and 2019) of three typical epikarst springs in Southwest China were investigated. Results showed that PAH concentrations in soil and water have an overall downward trend (a reduction of 57 % and 93 %, respectively) in the past 10 years, which is consistent with the downward trend in the relative contribution rate of raw coal production (a 66 % reduction). In terms of composition, the proportion of low-ring PAHs decreased, medium-ring and high-ring PAHs increased in the soil profile. The proportion of low-ring PAHs did not change obviously, the proportion of medium-ring PAHs increased, and the proportion of high-ring PAHs decreased in epikarst springs. The source of PAHs changed remarkably over time, the relative contribution of coal combustion to PAHs decreased from 38 % to 20 %, and the vehicle contribution of PAHs increased from 31 % to 44 % in soils. The relative contribution rate of unburned oil and coke oven and biomass combustion change is less. Furthermore, the ecological risk of PAHs in the soils was reduced from moderate risk 2 to moderate risk 1, the risk in epikarst spring was reduced from high risk to moderate risk 2 after 10 years. This study demonstrates that substituting petroleum and coal with green energies can reduce PAH concentrations and risk.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Poluentes do Solo , Humanos , Solo , Água , Monitoramento Ambiental/métodos , Poluentes do Solo/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Carvão Mineral/análise , China , Medição de Risco
16.
J Sci Food Agric ; 103(12): 6033-6043, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37119403

RESUMO

BACKGROUND: Large yellow croaker (Larimichthys crocea) is an economical marine fish consumed in China. Theaflavins have antibacterial and antioxidant properties. However, there is a lack of research into their application in large yellow croakers during refrigerated storage. This study investigated the effect of theaflavins on the quality of large yellow croaker (Larimichthys crocea) during 12 days of storage at 4 °C. RESULTS: The results showed that theaflavin treatment was able to inhibit microbial growth and reduce the production of total volatile basic nitrogen (TVB-N). Meanwhile, theaflavins were beneficial in reducing the unfolding of myofibrillar proteins, decreasing the degree of protein aggregation, and improving the stability of protein structure. The degree of protein oxidation was lower in a theaflavin-treated group compared with an untreated group. Theaflavin treatment effectively inhibited increases in acid value (AV), peroxide value (PV), and malonaldehyde (MDA) content. The effect of theaflavin was positively correlated with an increase in concentration under refrigeration conditions. This study therefore suggests that the use of theaflavins is a viable method for extending the period for which refrigerated large yellow croaker can be preserved. CONCLUSIONS: Adding theaflavins to large yellow croaker can be an effective method for preserving quality during refrigerated storage. © 2023 Society of Chemical Industry.


Assuntos
Antioxidantes , Perciformes , Animais , Antioxidantes/farmacologia , China
17.
Angew Chem Int Ed Engl ; 62(36): e202308523, 2023 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-37370248

RESUMO

Constructing a powerful photocatalytic system that can achieve the carbon dioxide (CO2 ) reduction half-reaction and the water (H2 O) oxidation half-reaction simultaneously is a very challenging but meaningful task. Herein, a porous material with a crystalline topological network, named viCOF-bpy-Re, was rationally synthesized by incorporating rhenium complexes as reductive sites and triazine ring structures as oxidative sites via robust -C=C- bond linkages. The charge-separation ability of viCOF-bpy-Re is promoted by low polarized π-bridges between rhenium complexes and triazine ring units, and the efficient charge-separation enables the photogenerated electron-hole pairs, followed by an intramolecular charge-transfer process, to form photogenerated electrons involved in CO2 reduction and photogenerated holes that participate in H2 O oxidation simultaneously. The viCOF-bpy-Re shows the highest catalytic photocatalytic carbon monoxide (CO) production rate (190.6 µmol g-1 h-1 with about 100 % selectivity) and oxygen (O2 ) evolution (90.2 µmol g-1 h-1 ) among all the porous catalysts in CO2 reduction with H2 O as sacrificial agents. Therefore, a powerful photocatalytic system was successfully achieved, and this catalytic system exhibited excellent stability in the catalysis process for 50 hours. The structure-function relationship was confirmed by femtosecond transient absorption spectroscopy and density functional theory calculations.

18.
J Neurosci ; 41(35): 7420-7434, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34301827

RESUMO

Neurons in the PFC are typically activated by different cognitive tasks, and also by different stimuli and abstract variables within these tasks. A single neuron's selectivity for a given stimulus dimension often changes depending on its context, a phenomenon known as nonlinear mixed selectivity (NMS). It has previously been hypothesized that NMS emerges as a result of training to perform tasks in different contexts. We tested this hypothesis directly by examining the neuronal responses of different PFC areas before and after male monkeys were trained to perform different working memory tasks involving visual stimulus locations and/or shapes. We found that training induces a modest increase in the proportion of PFC neurons with NMS exclusively for spatial working memory, but not for shape working memory tasks, with area 9/46 undergoing the most significant increase in NMS cell proportion. We also found that increased working memory task complexity, in the form of simultaneously storing location and shape combinations, does not increase the degree of NMS for stimulus shape with other task variables. Lastly, in contrast to the previous studies, we did not find evidence that NMS is predictive of task performance. Our results thus provide critical insights on the representation of stimuli and task information in neuronal populations, in working memory.SIGNIFICANCE STATEMENT How multiple types of information are represented in working memory remains a complex computational problem. It has been hypothesized that nonlinear mixed selectivity allows neurons to efficiently encode multiple stimuli in different contexts, after subjects have been trained in complex tasks. Our analysis of prefrontal recordings obtained before and after training monkeys to perform working memory tasks only partially agreed with this prediction, in that nonlinear mixed selectivity emerged for spatial but not shape information, and mostly in mid-dorsal PFC. Nonlinear mixed selectivity also displayed little modulation across either task complexity or correct performance. These results point to other mechanisms, in addition to nonlinear mixed selectivity, representing complex information about stimulus and task context in neuronal activity.


Assuntos
Aprendizagem/fisiologia , Memória de Curto Prazo/fisiologia , Córtex Pré-Frontal/fisiologia , Animais , Macaca mulatta , Masculino , Neurônios/fisiologia , Dinâmica não Linear , Movimentos Sacádicos/fisiologia , Comportamento Espacial/fisiologia
19.
J Cell Physiol ; 237(8): 3292-3304, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35616291

RESUMO

Bisphenol A (BPA) in the environment can have deleterious effects on humans and animals. BPA can exert nephrotoxicity by inducing oxidative stress. Selenium (Se) deficiency can specifically impair kidney tissues and additionally show a synergistic effect on the toxicity of several environmental chemicals. However, the toxic effects of BPA on the chicken kidney and whether Se deficiency produces synergistic effects on the toxicity of BPA remain poorly understood. Herein, we established BPA exposure models and Se deficiency model in vivo and in vitro, and described the discovery path of BPA aggravation on apoptosis and necroptosis in Se-deficient chicken kidneys via regulation of oxidative stress and phosphatidylinositol 3-kinase/threonine kinase (PI3K/AKT) signaling pathway. We found that BPA exposure increased reactive oxygen species and malondialdehyde levels, reduced activities of catalase, GPx, and superoxide dismutase, downregulated PI3K and AKT expressions, activated Bcl/Bax-Caspase 9-Caspase 3, and receptor-interacting protein kinase 1/mixed lineage kinase domain-like protein signaling pathways, resulting in apoptosis and necroptosis in the chicken kidney. In addition, Se deficiency significantly promoted the expression of renal apoptosis and necroptosis in BPA-exposed chicken kidneys. Altogether, our results showed that BPA aggravates apoptosis and necroptosis in Se-deficient chicken kidneys via regulation of oxidative stress and PI3K/AKT signaling pathway. Our findings elucidate the mechanism of BPA nephrotoxicity and Se deficiency exacerbation toxicity in chickens and will provide great significance for the protection of the ecological environment and animal health.


Assuntos
Compostos Benzidrílicos , Rim , Fenóis , Selênio , Animais , Apoptose , Compostos Benzidrílicos/toxicidade , Galinhas/metabolismo , Rim/efeitos dos fármacos , Rim/patologia , Necroptose , Estresse Oxidativo , Fenóis/toxicidade , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Selênio/deficiência
20.
Mol Biol Evol ; 38(4): 1529-1536, 2021 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-33283852

RESUMO

The rise and expansion of Tibetan Empire in the 7th to 9th centuries AD affected the course of history across East Eurasia, but the genetic impact of Tibetans on surrounding populations remains undefined. We sequenced 60 genomes for four populations from Pakistan and Tajikistan to explore their demographic history. We showed that the genomes of Balti people from Baltistan comprised 22.6-26% Tibetan ancestry. We inferred a single admixture event and dated it to about 39-21 generations ago, a period that postdated the conquest of Baltistan by the ancient Tibetan Empire. The analyses of mitochondrial DNA, Y, and X chromosome data indicated that both ancient Tibetan males and females were involved in the male-biased dispersal. Given the fact that the Balti people adopted Tibetan language and culture in history, our study suggested the impact of Tibetan Empire on Baltistan involved dominant cultural and minor demic diffusion.


Assuntos
Fluxo Gênico , Genoma Humano , Feminino , Humanos , Masculino , Paquistão , Tibet/etnologia , Sequenciamento Completo do Genoma
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