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1.
Enzyme Microb Technol ; 178: 110447, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38626534

RESUMO

Clostridium butyricum (C. butyricum) represents a new generation of probiotics, which is beneficial because of its good tolerance and ability to produce beneficial metabolites, such as short-chain fatty acids and enzymes; however, its low enzyme activity limits its probiotic efficacy. In this study, a mutant strain, C. butyricum FZM 240 was obtained using carbon ion beam irradiation, which exhibited greatly improved enzyme production and tolerance. The highest filter paper, endoglucanase, and amylase activities produced by C. butyricum FZM 240 were 125.69 U/mL, 225.82 U/ mL, and 252.28 U/mL, which were 2.58, 1.95, and 2.21-fold higher, respectively, than those of the original strain. The survival rate of the strain increased by 11.40 % and 5.60 % after incubation at 90 °C for 5 min and with simulated gastric fluid at pH 2.5 for 2 h, respectively, compared with that of the original strain. Whole-genome resequencing and quantitative real-time PCR(qRT-PCR) analysis showed that the expression of genes related to enzyme synthesis (GE000348, GE001963 and GE003123) and tolerance (GE001114) was significantly up-regulated, while that of genes related to acid metabolism (GE003450) was significantly down-regulated. On this basis, homology modeling and functional prediction of the proteins encoded by the mutated genes were performed. According to the results, the properties related to the efficacy of C. butyricum as a probiotic were significantly enhanced by carbon ion beam irradiation, which is a novel strategy for the application of Clostridium spp. as feed additives.

2.
Brain Behav ; 14(3): e3430, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38433103

RESUMO

BACKGROUND: Craniopharyngiomas are low-grade malignancies (WHO I) in the sellar region. Most cases of childhood-onset craniopharyngioma are adamantinomatous craniopharyngioma, and neurosurgery is the treatment of choice. Affected patients have postoperative complications, including water and electrolyte disturbances, because these malignancies develop near the hypothalamus and pituitary gland. Determining postoperative serum sodium fluctuation patterns in these patients can reduce postoperative mortality and improve prognosis. OBJECTIVE: To measure changes in serum sodium levels in pediatric patients who underwent craniopharyngioma surgery and identify influencing factors. METHODS: This retrospective study measured the serum sodium levels of 202 patients aged 0-18 years who underwent craniopharyngioma resection in Beijing Tiantan Hospital and Beijing Children's Hospital and identified predictors of severe hyponatremia and hypernatremia. RESULTS: The mean age of the cohort was 8.35 ± 4.35 years. The prevalence of hypernatremia, hyponatremia, and their severe forms (serum Na+  > 150 mmol/L and serum Na+  < 130 mmol/L) within 14 days after surgery was 66.3%, 72.8%, 37.1%, and 40.6%, respectively. The mean postoperative serum sodium level showed a triphasic pattern, characterized by two peaks separated by a nadir. Sodium levels peaked on days 2 (143.6 ± 7.6 mmol/L) and 14 (143.2 ± 6.7 mmol/L) and reached their lowest on day 6 (135.5 ± 7.5 mmol/L). A total of 31 (15.3%) patients met the diagnostic threshold for hyponatremia and hypernatremia of the triphase response, whereas 116 (57.4%) patients presented this pattern, regardless of met the diagnostic criteria or not. The prevalence of severe hyponatremia varied depending on preoperative endocrine hormone deficiency, tumor status (primary or recurrent), and surgical approach. CONCLUSIONS: Serum sodium levels after craniopharyngioma resection in children showed a triphasic pattern in most cases. The risk of postoperative hyponatremia varied depending on preoperative endocrine hormone deficiency, tumor status (primary or recurrent), and surgical approach.


Assuntos
Craniofaringioma , Hipernatremia , Hiponatremia , Neoplasias Hipofisárias , Humanos , Criança , Pré-Escolar , Craniofaringioma/cirurgia , Hipernatremia/epidemiologia , Hipernatremia/etiologia , Hiponatremia/epidemiologia , Hiponatremia/etiologia , Estudos Retrospectivos , Neoplasias Hipofisárias/cirurgia , Hormônios , Sódio
3.
Cell Metab ; 36(2): 438-453.e6, 2024 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-38325338

RESUMO

The hypothalamus plays a crucial role in the progression of obesity and diabetes; however, its structural complexity and cellular heterogeneity impede targeted treatments. Here, we profiled the single-cell and spatial transcriptome of the hypothalamus in obese and sporadic type 2 diabetic macaques, revealing primate-specific distributions of clusters and genes as well as spatial region, cell-type-, and gene-feature-specific changes. The infundibular (INF) and paraventricular nuclei (PVN) are most susceptible to metabolic disruption, with the PVN being more sensitive to diabetes. In the INF, obesity results in reduced synaptic plasticity and energy sensing capability, whereas diabetes involves molecular reprogramming associated with impaired tanycytic barriers, activated microglia, and neuronal inflammatory response. In the PVN, cellular metabolism and neural activity are suppressed in diabetic macaques. Spatial transcriptomic data reveal microglia's preference for the parenchyma over the third ventricle in diabetes. Our findings provide a comprehensive view of molecular changes associated with obesity and diabetes.


Assuntos
Diabetes Mellitus , Núcleo Hipotalâmico Paraventricular , Animais , Núcleo Hipotalâmico Paraventricular/metabolismo , Transcriptoma/genética , Hipotálamo/metabolismo , Obesidade/metabolismo , Diabetes Mellitus/metabolismo , Perfilação da Expressão Gênica
4.
Food Chem ; 441: 138324, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38176145

RESUMO

To develop the application of wheat bran and improve the nutrition and anti-staling capacity of Chinese steamed bread (CSB), oleic acid-esterified wheat bran (OWB) was prepared by esterification of wheat bran with oleic acid, and its physicochemical properties, structure, and quality improvement for CSB during refrigerated storage were investigated. The hydrophilic-lipophilic balance value of OWB was 16.0, the maximum degree of substitution was 0.146, and its emulsifying capacity was similar to that of glycerol monostearate. The starch gelatinization degree of CSB containing 3 % OWB and the control decreased by 19.55 % and 27.12 % within 7 days of refrigerated storage, respectively, while the hardness of CSB with OWB was lower than that with wheat bran. OWB inhibited starch recrystallization and increased bound water in the corresponding CSB, which effectively delayed starch retrogradation. OWB had a positive emulsifying capacity and showed potential as a functional material for preventing retrogradation of starch-based foods.


Assuntos
Pão , Fibras na Dieta , Pão/análise , Fibras na Dieta/análise , Melhoria de Qualidade , Ácido Oleico , Amido/química , Vapor , China
5.
Neuron ; 112(7): 1081-1099.e7, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38290516

RESUMO

Oxytocin (OXT) plays important roles in autonomic control and behavioral modulation. However, it is unknown how the projection patterns of OXT neurons align with underlying physiological functions. Here, we present the reconstructed single-neuron, whole-brain projectomes of 264 OXT neurons of the mouse paraventricular hypothalamic nucleus (PVH) at submicron resolution. These neurons hierarchically clustered into two groups, with distinct morphological and transcriptional characteristics and mutually exclusive projection patterns. Cluster 1 (177 neurons) axons terminated exclusively in the median eminence (ME) and have few collaterals terminating within hypothalamic regions. By contrast, cluster 2 (87 neurons) sent wide-spread axons to multiple brain regions, but excluding ME. Dendritic arbors of OXT neurons also extended outside of the PVH, suggesting capability to sense signals and modulate target regions. These single-neuron resolution observations reveal distinct OXT subpopulations, provide comprehensive analysis of their morphology, and lay the structural foundation for better understanding the functional heterogeneity of OXT neurons.


Assuntos
Ocitocina , Núcleo Hipotalâmico Paraventricular , Animais , Camundongos , Hipotálamo , Neurônios/fisiologia , Ocitocina/fisiologia , Núcleo Hipotalâmico Paraventricular/fisiologia
6.
Int J Biol Macromol ; 257(Pt 2): 128591, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38052287

RESUMO

In this work, the modified gluten was prepared by enzymolysis combined with Maillard reaction (MEG), and its functional and structural properties were investigated. The result showed that the maximum foamability of MEG was 19.58 m2/g, the foam stability was increased by 1.8 times compared with gluten, and the solubility and degree of graft were increased to 44.4 % and 28.1 % at 100 °C, whereas the content of sulfhydryl group decreased to 0.81 µmol/g. The scavenging ability on ABTS+radical and DPPH radical of MEG was positively correlated with reaction temperature, and the maximum values were 86.57 % and 71.71 % at 140 °C, respectively. Furthermore, the fluorescence quenching effect of tryptophan and tyrosine residues was enhanced, while the fluorescence intensity decreased with the temperature increase. Scanning electron microscopy revealed that the surface of enzymatically hydrolyzed-gluten became smooth and the cross section became straightened, while MEG turned smaller and irregular approaching a circular structure. FT-IR spectroscopy showed that enzymatic hydrolysis promoted the occurrence of more carbonyl ammonia reactions and the formation of precursors of advanced glycosylation end products. These results provide a feasible method for improving the structure and functional properties of gluten protein.


Assuntos
Glutens , Reação de Maillard , Glutens/química , Espectroscopia de Infravermelho com Transformada de Fourier , Hidrólise , Solubilidade
7.
Eur J Clin Nutr ; 78(1): 54-63, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37816846

RESUMO

BACKGROUND AND OBJECTIVES: Cumulative lipid profile burden is designed to dynamically measure lipid accumulation, and its effect on hypertension has been poorly studied. Our main purpose was to investigate the effect of cumulative lipid profile burden on the incidence of essential hypertension (EH) and to investigate whether cumulative lipid burden mediates the pathogenesis of the effects of diet and obesity on EH. SUBJECTS AND METHODS: A total of 1295 participants were included in the study, which started in 2017. The average follow-up time was 2.98 years. A total of 240 EH patients occurred during the follow-up period. RESULTS: The HR (95% CI) of the highest quartile in cumulative Total cholesterol (TC), triglyceride (TG) and high density lipoprotein (HDL) burden were 1.747 (1.145 - 2.664), 1.502 (1.038 - 2.173), 0.615 (0.413 - 0.917) for incidence of EH respectively, compared to the respective reference groups. Participants with EH consumed more red meat and refined grains, and red meat was positively associated with cumulative TC burden. BMI and Waist-To-Height Ratio (WHtR) increased the incidence of EH, and obesity was positively correlated with cumulative TG burden. Mediating analysis showed that cumulative TG had a partial mediating effect in the causal relationship between obesity and EH, and Mendelian randomization (MR) also proved this result. Diet was not found to influence EHn through cumulative lipid profile burden. CONCLUSIONS: The cumulative TG burden partially mediates the effect of obesity on EH.


Assuntos
Hipertensão , Humanos , Estudos de Coortes , Índice de Massa Corporal , Hipertensão/epidemiologia , Hipertensão/etiologia , Obesidade/complicações , Triglicerídeos , Hipertensão Essencial , Dieta , China/epidemiologia , HDL-Colesterol
8.
Materials (Basel) ; 16(21)2023 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-37959433

RESUMO

Dual-phase high-entropy alloys with excellent room temperature and high-temperature properties have been widely studied as potential high-temperature structural materials. However, interface weakening causes its high-temperature performance to decline at higher temperatures, severely limiting further development. In this study, a series of Al17Cr10Fe36Ni36Mo1Hfx (x = 0, 0.03, 0.15, 0.3, 0.5, and 0.8 at%) alloys were prepared to study the effect of Hf content on the microstructure and mechanical properties of the matrix alloy. The results indicate that with the addition of the Hf, the Hf-rich phase began to precipitate at the interface and inside the B2 phase in the matrix alloy. In contrast, the morphology of both the FCC and B2 phases had no noticeable change. With the increase in Hf content, the high-temperature strength and ductility of the alloy first increased and then decreased, while the room temperature performance remained almost unchanged. Benefiting from the hindrance of the Hf-rich phase to grain boundary sliding and dislocation movement during high-temperature deformation, the tensile strength, yield strength, and plasticity of the matrix alloy increased from 474 MPa, 535 MPa, and 8.7% to 816 MPa, 923 MPa, and 42.0% for the Al17Cr10Fe36Ni36Mo1Hf0.5 alloys, respectively. This work provides a new path for designing a high-entropy alloy with excellent high-temperature mechanical properties.

9.
Chin Med J (Engl) ; 2023 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-38030389

RESUMO

BACKGROUND: Ebstein's anomaly (EA) is a rare and complex congenital heart anomaly, and the effect of surgical treatment is not ideal. This study aims to introduce our experience in management strategies, surgical techniques, and operative indications for patients with Ebstein's anomaly. METHODS: A retrospective study of 258 operations was performed in 253 patients by the same cardiac surgeon in The First Hospital of Tsinghua University between March 2004 and January 2020. 32 patients had previously received cardiac surgery in other hospitals. The clinical data including diagnosis, operative indications, techniques, pathological changes, and survival rates were collected and analyzed. RESULTS: Anatomical correction was performed in 203 (78.7%) operations, 1½ ventricle repair in 38 (14.7%) operations, tricuspid valve repair only in four operations (1.6%), tricuspid valve replacement in ten (3.9%), total cavopulmonary connection (TCPC) in two (0.8%), and Glenn operation in one operation (0.4%). Reoperation was performed in five patients (2.0%) during hospitalization. Among them, tricuspid valve replacement was performed in one patient, 1½ ventricle repair in two patients, and tricuspid valve annulus reinforcement in two patients. Five patients died with an early mortality rate of 2.0%. Complete atrioventricular conduction block was complicated in one patient (0.4%). A total of 244 patients was followed up (four in the 253 patients lost) with a duration of 3.0-168.0 (87.6 ± 38.4) months. Cardiac function of 244 patients improved significantly with mean New York Heart Association (NYHA) functional class recovery from 3.5 to 1.1. The mean grade of tricuspid valve regurgitation improved from 3.6 to 1.5. Three late deaths (1.2%) occurred. The survival rates at five and ten years after surgery were 98.6% and 98.2%, respectively. Reoperation was performed in five patients (2.0%) during the follow-up period. CONCLUSION: Based on our management strategies and operative principles and techniques, anatomical correction of EA is capable of achieving excellent long-term results, and low rates of TCPC, 1½ ventricle repair and valvular replacement.

10.
Small ; : e2307040, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37967337

RESUMO

The practical application of Li-S batteries is still severely restricted by poor cyclic performance caused by the intrinsic polysulfides shuttle effect, which is even more severe under the high-temperature condition owing to the inevitable increase of polysulfides' solubility and diffusion rate. Herein, tungsten-doped vanadium dioxide (W-VO2 ) micro-flowers are employed with first-order metal-insulator phase transition (MIT) property as a robust and multifunctional modification layer to hamper the shuttle effect and simultaneously improve the thermotolerance of the common separator. Tungsten doping significantly reduces the transition temperature from 68 to 35 °C of vanadium dioxide, which renders the W-VO2 easier to turn from the insulating monoclinic phase into the metallic rutile phase. The systematic experiments and theoretical analysis demonstrate that the temperature-induced in-suit MIT property endows the W-VO2 catalyst with strong chemisorption against polysulfides, low energy barrier for liquid-to-solid conversion, and outstanding diffusion kinetics of Li-ion under high temperatures. Benefiting from these advantages, the Li-S batteries with W-VO2 modified separator exhibit significantly improved rate and long-term cyclic performance under 50 °C. Remarkably, even at an elevated temperature (80 °C), they still exhibit superior electrochemical performance. This work opens a rewarding avenue to use phase-changing materials for high-temperature Li-S batteries.

11.
Front Endocrinol (Lausanne) ; 14: 1241145, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38027203

RESUMO

Objective: Hypothalamic-pituitary axis dysfunction is a common complication in post-operative craniopharyngioma(CP) patients, and it greatly impacts the long-term quality of life of such patients. To better understand the effects of postoperative hypothalamic-pituitary dysfunction and long-term hormone replacement therapy in patients with childhood CP, we assessed approximately 200 patients with childhood-onset CP postoperatively. Methods: Clinical details of patients with childhood-onset CP who underwent sellar tumor resection in Beijing Children's Hospital and Beijing Tiantan Hospital from 2018 to 2019 were retrieved retrospectively. The participants were followed up to assess the effects of post-operative long-term hormone replacement therapy and assess the tumor recurrence rate. Results: The median age of admission was 8.1 (1.8, 14.3) years. Headache (45.5%), visual impairment (39.5%), and nausea (33.0%) were the most common clinical manifestations. ACP accounted for 95% of all CP cases. The incidence of central adrenal insufficiency and central hypothyroidism within the first week after surgery was 56.2% and 70.3%, respectively. At the same time 85.5% of the patients required at least one dose of desmopressin to control urine output. Total survival and tumor recurrence rates were 98.6% and 26.1%, respectively, with a median follow-up time of 29.7 (19.0, 40.3) months. During the follow-up period, 28.1% patients met the diagnostic criteria for short stature, while 54.4% fit the criteria for obesity. In addition, 94.4% of the patients were taking at least one kind of hormone substitution, and 74.7% were taking three or more. The prevalence of levothyroxine, glucocorticoid, desmopressin, and growth hormone replacement therapy was 87.3%, 77.5%, 78.9% and 31.0%, respectively. The proportion of patients treated with the substitutive combination of levothyroxine, hydrocortisone, and desmopressin was 54.9%. Conclusion: This study is a large-sample systematic postoperative endocrine function evaluation of patients with childhood-onset CP. Due to the high prevalence of post-operative hypothalamic-pituitary dysfunction, patients with CP usually require long-term multiple hormone substitution therapy. Individualized management and accurate hormone replacement dosage for postoperative childhood-onset CP patients are of great importance.


Assuntos
Craniofaringioma , Doenças Hipotalâmicas , Doenças da Hipófise , Neoplasias Hipofisárias , Humanos , Criança , Craniofaringioma/complicações , Craniofaringioma/epidemiologia , Craniofaringioma/cirurgia , Estudos Retrospectivos , Tiroxina , Qualidade de Vida , Desamino Arginina Vasopressina , Recidiva Local de Neoplasia/complicações , Neoplasias Hipofisárias/epidemiologia , Neoplasias Hipofisárias/cirurgia , Neoplasias Hipofisárias/complicações , Doenças Hipotalâmicas/complicações , Doenças da Hipófise/complicações , Terapia de Reposição Hormonal , Hidrocortisona
12.
MedComm (2020) ; 4(5): e372, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37746666

RESUMO

High myopia is a leading cause of blindness worldwide with increasing prevalence. Retina percepts visual information and triggers myopia development, but the underlying etiology is not fully understood because of cellular heterogeneity. In this study, single-cell RNA sequencing analysis was performed on retinas of mouse highly myopic and control eyes to dissect the involvement of each cell type during high myopia progression. For highly myopic photoreceptors, Hk2 inhibition underlying metabolic remodeling from aerobic glycolysis toward oxidative phosphorylation and excessive oxidative stress was identified. Importantly, a novel Apoe + rod subpopulation was specifically identified in highly myopic retina. In retinal neurons of highly myopic eyes, neurodegeneration was generally discovered, and the imbalanced ON/OFF signaling driven by cone-bipolar cells and the downregulated dopamine receptors in amacrine cells were among the most predominant findings, indicating the aberrant light processing in highly myopic eyes. Besides, microglia exhibited elevated expression of cytokines and TGF-ß receptors, suggesting enhanced responses to inflammation and the growth-promoting states involved in high myopia progression. Furthermore, cell-cell communication network revealed attenuated neuronal interactions and increased glial/vascular interactions in highly myopic retinas. In conclusion, this study outlines the transcriptional landscape of highly myopic retina, providing novel insights into high myopia development and prevention.

13.
ACS Appl Mater Interfaces ; 15(40): 46971-46981, 2023 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-37755826

RESUMO

The exploitation of high-performance supercapacitors is crucial to promote energy storage technologies. Benefiting from the three-dimensional conductive micronanostructures and high specific capacity of the PPy@CuCo2S4@NF (polypyrrole/copper cobalt sulfide/nickel foam) composite electrode, this electrode exhibits a high specific capacity of 1403.21 C g-1 at 1 A g-1 and a capacitance retention of 85.79% after 10,000 cycles at 10 A g-1. The assembled PPy@CuCo2S4@NF//AC aqueous hybrid supercapacitor (AHSC) reveals a wide operating potential window of 1.5 V and achieves a high specific capacity of 322.52 C g-1 at 1 A g-1 and a capacitance retention of 86.84% after 15,000 cycles at 10 A g-1. The AHSC also exhibits a high power density of 733.69 W kg-1 at an energy density of 67.19 W h kg-1, surpassing those of previously reported spinel-based supercapacitors. Ex situ X-ray diffraction and X-ray photoelectron spectroscopy results show that the CuCo2S4 spinel structure changes to CuS2 and CoS2 cube structures, and the oxidation states of Cu and Co increase during charging and discharging processes. Density functional theory calculations suggest a superior conductivity for CuCo2S4 compared to that for CuCo2O4, demonstrating that CuCo2S4 has superior electrochemical performance. These findings attest to the considerable potential of the spinel materials for advanced energy storage applications.

14.
Cell Discov ; 9(1): 94, 2023 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-37699875

RESUMO

High myopia is a leading cause of blindness worldwide. It may lead to emotional defects that rely closely on the link between visual sensation and the central nervous system. However, the extent of the defects and its underlying mechanism remain unknown. Here, we report that highly myopic patients exhibit greater anxiety, accompanied by higher CC chemokine ligand 2 (CCL2) and monocyte levels in the blood. Similar findings are found in the mouse model of high myopia. Mechanistic evaluations using GFP-positive bone marrow chimeric mice, parabiotic mouse model, enhanced magnetic resonance imaging, etc., show that highly myopic visual stimulation increases CCL2 expression in eyes, aggravates monocyte/macrophage infiltration into eyes and brains, and disrupts blood-ocular barrier and blood-brain barrier of mice. Conversely, Ccl2-deficient highly myopic mice exhibit attenuated ocular and brain infiltration of monocytes/macrophages, reduced disruption of the blood-ocular barrier and blood-brain barrier, and less anxiety. Substantial alleviation of high myopia-related anxiety can also be achieved with the administration of CCL2-neutralizing antibodies. Our results establish the association between high myopia and anxiety, and implicate the CCL2-mediated inflammatory pathogenesis as an underlying mechanism.

15.
ACS Appl Mater Interfaces ; 15(33): 39384-39395, 2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37555537

RESUMO

Efficient electrocatalysts and catalytic mechanisms remain a pressing need in Li-S electrochemistry to address lithium polysulfide (LiPS) shuttling and enhance conversion kinetics. This study presents the development of multifunctional VO2@rGO heterostructures, incorporating interfacial built-in electric field (BIEF) enhancement, as a Mott-Schottky electrocatalyst for Li-S batteries. Electrochemical experiments and theoretical analysis demonstrate that the interfacial BIEF between VO2 and rGO induces self-driven charge redistribution, resulting in accelerated charge transport rates, enhanced LiPS chemisorption, reduced energy barriers for Li2S nucleation/decomposition, and improved Li-ion diffusion behavior. The Mott-Schottky electrocatalyst, combining the strengths of VO2's anchoring ability, rGO's metallic conductivity, and BIEF's optimized charge transport, exhibits an outstanding "trapping-conversion" effect. The modified Li-S battery with a VO2@rGO-modified separator achieves a highly reversible capacity of 558.0 mAh g-1 at 2 C over 600 cycles, with an average decay rate of 0.048% per cycle. This research offers valuable insights into the design of Mott-Schottky electrocatalysts and their catalytic mechanisms, advancing high-efficiency Li-S batteries and other multielectron energy storage and conversion devices.

16.
Cell ; 186(15): 3245-3260.e23, 2023 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-37369203

RESUMO

Terrestrial organisms developed circadian rhythms for adaptation to Earth's quasi-24-h rotation. Achieving precise rhythms requires diurnal oscillation of fundamental biological processes, such as rhythmic shifts in the cellular translational landscape; however, regulatory mechanisms underlying rhythmic translation remain elusive. Here, we identified mammalian ATXN2 and ATXN2L as cooperating master regulators of rhythmic translation, through oscillating phase separation in the suprachiasmatic nucleus along circadian cycles. The spatiotemporal oscillating condensates facilitate sequential initiation of multiple cycling processes, from mRNA processing to protein translation, for selective genes including core clock genes. Depleting ATXN2 or 2L induces opposite alterations to the circadian period, whereas the absence of both disrupts translational activation cycles and weakens circadian rhythmicity in mice. Such cellular defect can be rescued by wild type, but not phase-separation-defective ATXN2. Together, we revealed that oscillating translation is regulated by spatiotemporal condensation of two master regulators to achieve precise circadian rhythm in mammals.


Assuntos
Relógios Circadianos , Camundongos , Animais , Relógios Circadianos/genética , Ritmo Circadiano/fisiologia , Núcleo Supraquiasmático/metabolismo , Processamento de Proteína Pós-Traducional , Mamíferos
17.
Sensors (Basel) ; 23(11)2023 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-37299786

RESUMO

Network traffic anomaly detection is a key step in identifying and preventing network security threats. This study aims to construct a new deep-learning-based traffic anomaly detection model through in-depth research on new feature-engineering methods, significantly improving the efficiency and accuracy of network traffic anomaly detection. The specific research work mainly includes the following two aspects: 1. In order to construct a more comprehensive dataset, this article first starts from the raw data of the classic traffic anomaly detection dataset UNSW-NB15 and combines the feature extraction standards and feature calculation methods of other classic detection datasets to re-extract and design a feature description set for the original traffic data in order to accurately and completely describe the network traffic status. We reconstructed the dataset DNTAD using the feature-processing method designed in this article and conducted evaluation experiments on it. Experiments have shown that by verifying classic machine learning algorithms, such as XGBoost, this method not only does not reduce the training performance of the algorithm but also improves its operational efficiency. 2. This article proposes a detection algorithm model based on LSTM and the recurrent neural network self-attention mechanism for important time-series information contained in the abnormal traffic datasets. With this model, through the memory mechanism of the LSTM, the time dependence of traffic features can be learned. On the basis of LSTM, a self-attention mechanism is introduced, which can weight the features at different positions in the sequence, enabling the model to better learn the direct relationship between traffic features. A series of ablation experiments were also used to demonstrate the effectiveness of each component of the model. The experimental results show that, compared to other comparative models, the model proposed in this article achieves better experimental results on the constructed dataset.


Assuntos
Algoritmos , Engenharia , Aprendizado de Máquina , Redes Neurais de Computação , Registros
18.
Opt Express ; 31(7): 11624-11632, 2023 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-37155793

RESUMO

The optimization of trichromatic white light emitting diodes (LEDs) spectrum for application scenes related to the age of lighting users is proposed and demonstrated. Based on the spectral transmissivity of human eyes at different ages, the visual and non-visual responses of human eyes to different wavelengths of light, we have built the blue light hazards (BLH) and circadian action factor (CAF) related to the age of the lighting user. The BLH and CAF are used to evaluate the spectral combinations of high color rendering index (CRI) white LEDs obtained from different radiation flux ratios of red, green, and blue monochrome spectrum. The best spectra of white LEDs for lighting users at different ages in work and leisure scenes are achieved due to the optimization criterion of BLH proposed by us. This research provides a solution for intelligent health lighting design applicable to light users of different ages and application scenes.

19.
Yi Chuan ; 45(5): 425-434, 2023 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-37194589

RESUMO

Hypothalamic median eminence (ME) is a potential niche for neurons and oligodendrocytes, and trophic factors may regulate hypothalamic function by inducing cellular changes in the ME region. To determine whether diet-induced plasticity exists in hypothalamic stem cells dormant under physiological conditions, we used a combination of a normal diet, a high-fat diet, and a ketogenic diet (a low-carb, high-fat diet) to compare the proliferation of tanycytes (TCs) and oligodendrocyte precursor cells (OPCs) in the ME area of mice under the different diets. The results showed that the ketogenic diet could induce and promote the proliferation of OPCs in the ME area, and blocking the fatty acid oxidation program could inhibit the proliferation of OPCs induced by a ketogenic diet. This study preliminarily revealed the diet-induced effect on OPCs in the ME region and provided enlightenment for further study on the function of OPCs in the ME region.


Assuntos
Dieta Cetogênica , Células Precursoras de Oligodendrócitos , Camundongos , Animais , Eminência Mediana , Proliferação de Células , Ácidos Graxos , Diferenciação Celular
20.
Small ; 19(37): e2301085, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37194979

RESUMO

Polysulfide shuttle effect and sluggish sulfur reaction kinetics severely impede the cycling stability and sulfur utilization of lithium-sulfur (Li-S) batteries. Modulating d-band electronic structures of molybdenum disulfide electrocatalysts via p/n doping is promising to boost polysulfide conversion and suppress polysulfide migration in lithium-sulfur batteries. Herein, p-type V-doped MoS2 (V-MoS2 ) and n-type Mn-doped MoS2 (Mn-MoS2 ) catalysts are well-designed. Experimental results and theoretical analyses reveal that both of them significantly increase the binding energy of polysulfides on the catalysts' surface and accelerate the sluggish conversion kinetics of sulfur species. Particularly, the p-type V-MoS2 catalyst exhibits a more obvious bidirectional catalytic effect. Electronic structure analysis further demonstrates that the superior anchoring and electrocatalytic activities are originated from the upward shift of the d-band center and the optimized electronic structure induced by duplex metal coupling. As a result, the Li-S batteries with V-MoS2 modified separator exhibit a high initial capacity of 1607.2 mAh g-1 at 0.2 C and excellent rate and cycling performance. Moreover, even at a high sulfur loading of 6.84 mg cm-2 , a favorable initial areal capacity of 8.98 mAh cm-2 is achieved at 0.1 C. This work may bring widespread attention to atomic engineering in catalyst design for high-performance Li-S batteries.

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