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P2-type layered materials (Na x TMO2) have become attractive cathode electrodes owing to their high theoretical energy density and simple preparation. However, they still face severe phase transition and low conductivity. Current research on Na x TMO2 is mostly focused on the modification of bulk materials, and the application performances have been infrequently addressed. This review summarizes the information on current common P2-Na x TMO2 materials and discusses their sodium-storage mechanisms. Furthermore, modification strategies to improve their performance are addressed for practical applications based on a range of key parameters (output voltage, specific capacity, and lifespan). We also discuss the future development trends and application prospects for P2 cathode materials.
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Camellia oil, recognized as a high-quality edible oil endorsed by the Food and Agriculture Organization, is confronted with authenticity issues arising from fraudulent adulteration practices. These practices not only pose health risks but also lead to economic losses. This study proposes a novel machine learning framework, referred to as a transformer encoder backbone with a support vector machine regressor (TES), coupled with an electronic nose (E-nose), for detecting varying adulteration levels in camellia oil. Experimental results indicate that the proposed TES model exhibits the best performance in identifying the adulterated concentration of camellia oi, compared with five other machine learning models (the support vector machine, random forest, XGBoost, K-nearest neighbors, and backpropagation neural network). The results obtained by E-nose detection are verified by complementary Fourier transform infrared (FTIR) spectroscopy analysis for identifying functional groups, ensuring accuracy and providing a comprehensive assessment of the types of adulterants. The proposed TES model combined with E-nose offers a rapid, effective, and practical tool for detecting camellia oil adulteration. This technique not only safeguards consumer health and economic interests but also promotes the application of E-nose in market supervision.
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Background/purpose: As science and technology continue to advance, the utilization of intraoral scanners (IOSs) has become increasingly popular in the orthodontic workflow. The aim of this study was to discuss whether the degree of crowded arches affects scan accuracy. Materials and methods: Three different crowding levels of dental models (model MI: mild, model MO: moderate, and model SE: severe) were scanned using both an IOS and desktop scanner. Stereolithographic files were obtained and superimposed via CAD software to calculate differences between each measuring point of a model and the farthest corresponding point. The deviations from three models were compared with statistical analysis. Results: The trueness of different crowding arches showed that the deviation value of model SE was the maximum, followed by model MI, and model MO in the maxillary arch. In the mandibular arch, the order of the deviation from greatest to least was firstly model SE, then model MO, and model MI. Significant differences were observed among the maxillary models (P < 0.001), but there was no significant difference between models in the mandible (P = 0.669). Conclusion: The trueness of the three crowded arches is in the clinically acceptable range. The degree of crowding increases, the trueness of scanning at each position decreases. In the maxillary arch, more severe crowding corresponds to higher deviations. In the mandible, the degree of crowding is not explicitly related to the maximum deviation; therefore, the clinician should notice the deviation when using IOSs for crowding cases.
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Lung adenocarcinoma (LUAD) is highly lethal tumor; understanding immune response is crucial for current effective treatment. Research investigated immunogenic cell death (ICD) impact on LUAD through 75 ICD-related genes which encompass cell damage, endoplasmic reticulum stress, microenvironment, and immunity. Transcriptome data and clinical info were analyzed, revealing two ICD-related clusters: B, an immune osmotic subgroup, had better prognosis, stronger immune signaling, and higher infiltration, while A represented an immune-deficient subgroup. Univariate Cox analysis identified six prognostic genes (AGER, CD69, CD83, CLEC9A, CTLA4, and NT5E), forming a validated risk score model. It was validated across datasets, showing predictive performance. High-risk group had unfavorable prognosis, lower immune infiltration, and higher chemotherapy sensitivity. Conversely, low-risk group had better prognosis, higher immune infiltration, and favorable immunotherapy response. The key gene NT5E was examined via immunohistochemistry, with higher expression linked to poorer prognosis. NT5E was predominantly expressed in B cells, fibroblasts, and endothelial cells, correlated with immune checkpoints. These outcomes suggest that NT5E can serve as a LUAD therapeutic target. The study highlights gene predictive value, offers an efficient tumor assessment tool, guides clinical treatment strategies, and identifies NT5E as therapeutic target for LUAD.
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Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Humanos , Células Endoteliais , Morte Celular Imunogênica , Adenocarcinoma de Pulmão/tratamento farmacológico , Adenocarcinoma de Pulmão/genética , Imunoterapia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Microambiente TumoralRESUMO
INTRODUCTION: This study is to evaluate the safety and pharmacokinetics (PK) of larsucosterol (DUR-928 or 25HC3S) in subjects with alcohol-associated hepatitis (AH), a devastating acute illness without US Food and Drug Administration-approved therapies. METHODS: This phase 2a, multicenter, open-label, dose escalation study evaluated the safety, PK, and efficacy signals of larsucosterol in 19 clinically diagnosed subjects with AH. Based on the model for end-stage liver disease (MELD) score, 7 subjects were considered to have moderate AH and 12 to have severe AH. All subjects received 1 or 2 intravenous infusions (72 hours apart) of larsucosterol at a dose of 30, 90, or 150 mg and were followed up for 28 days. Efficacy signals from a subgroup of subjects with severe AH were compared with those from 2 matched arms of those with severe AH treated with standard of care (SOC), including corticosteroids, from a contemporaneous study. RESULTS: All 19 larsucosterol-treated subjects survived the 28-day study. Fourteen (74%) of all subjects including 8 (67%) of the subjects with severe AH were discharged ≤72 hours after receiving a single infusion. There were no drug-related serious adverse events nor early terminations due to the treatment. PK profiles were not affected by disease severity. Biochemical parameters improved in most subjects. Serum bilirubin levels declined notably from baseline to day 7 and day 28, and MELD scores were reduced at day 28. The efficacy signals compared favorably with those from 2 matched groups treated with SOC. Lille scores at day 7 were <0.45 in 16 of the 18 (89%) subjects with day 7 samples. Lille scores from 8 subjects with severe AH who received 30 or 90 mg larsucosterol (doses used in phase 2b trial) were statistically significantly lower ( P < 0.01) than those from subjects with severe AH treated with SOC from the contemporaneous study. DISCUSSION: Larsucosterol was well tolerated at all 3 doses in subjects with AH without safety concerns. Data from this pilot study showed promising efficacy signals in subjects with AH. Larsucosterol is being evaluated in a phase 2b multicenter, randomized, double-blinded, placebo-controlled (AHFIRM) trial.
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Doença Hepática Terminal , Hepatite Alcoólica , Humanos , Projetos Piloto , Índice de Gravidade de Doença , Hepatite Alcoólica/tratamento farmacológico , Hepatite Alcoólica/diagnósticoRESUMO
Being characterized by the self-adaption and high accuracy, the deep learning-based models have been widely applied in the 1D spectroscopy-related field. However, the "black-box" operation and "end-to-end" working style of the deep learning normally bring the low interpretability, where a reliable visualization is highly demanded. Although there are some well-developed visualization methods, such as Class Activation Mapping (CAM) and Gradient-weighted Class Activation Mapping (Grad-CAM), for the 2D image data, they cannot correctly reflect the weights of the model when being applied to the 1D spectral data, where the importance of position information is not considered. Here, aiming at the visualization of Convolutional Neural Network-based models toward the qualitative and quantitative analysis of 1D spectroscopy, we developed a novel visualization algorithm (1D Grad-CAM) to more accurately display the decision-making process of the CNN-based models. Different from the classical Grad-CAM, with the removal of the gradient averaging (GAP) and the ReLU operations, a significantly improved correlation between the gradient and the spectral location and a more comprehensive spectral feature capture were realized for 1D Grad-CAM. Furthermore, the introduction of difference (purity or linearity) and feature contribute in the CNN output in 1D Grad-CAM achieved a reliable evaluation of the qualitative accuracy and quantitative precision of CNN-based models. Facing the qualitative and adulteration quantitative analysis of vegetable oils by the combination of Raman spectroscopy and ResNet, the visualization by 1D Grad-CAM well reflected the origin of the high accuracy and precision brought by ResNet. In general, 1D Grad-CAM provides a clear vision about the judgment criterion of CNN and paves the way for CNN to a broad application in the field of 1D spectroscopy.
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Non-point source fugitive dust produced during municipal road construction is one of the main ambient air pollutants gravely threatening the life and health of construction workers and residents around construction areas. In this study, a gas-solid two-phase flow model is used to simulate the diffusion behavior of non-point source dust with different enclosure heights under wind loads. Moreover, the inhibitory effect of the enclosure on the diffusion of non-point source dust from construction to residential areas is analyzed. The results show that the physical blocking and reflux effects of the enclosure can effectively restrain dust diffusion. When the enclosure height is 3-3.5 m, the concentration of particulate matter in most sections of residential areas can be reduced to less than 40 µg/m3. Moreover, when the wind speed is 1-5 m/s and the enclosure height is 2-3.5 m, the diffusion height of non-point source dust particles above the enclosure is concentrated in the range 1.5-2 m. This study provides a scientific basis for setting the heights of enclosures and atomization sprinklers at construction sites. Further, effective measures are proposed to reduce the impact of non-point source dust on the air environment of residential areas and health of residents.
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Poluentes Atmosféricos , Poluição do Ar , Humanos , Poeira/análise , Monitoramento Ambiental/métodos , Material Particulado/análise , Poluentes Atmosféricos/análise , Vento , Poluição do Ar/análiseRESUMO
The letter is to respond to the recent publication "Trends in hospitalization for alcoholic hepatitis from 2011 to 2017: A USA nationwide study" (World J Gastroenterol 2022; 28: 5036-5046). We noticed a significant difference in the total numbers of reported hospitalized alcohol-associated hepatitis (AH) patients between this publication and our publication on Alcohol Clin Exp Res (2022; 46: 1472-1481). We believe the number of "AH-related hospitalizations" inflated by the inclusion of patients with non-AH forms of alcohol-associated liver disease.
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Hepatite Alcoólica , Hepatopatias Alcoólicas , Humanos , Hepatite Alcoólica/diagnóstico , Hepatite Alcoólica/epidemiologia , Pacientes Internados , HospitalizaçãoRESUMO
In recent years, more and more research has begun to focus on the flexible and lightweight design of wearable robots. During this process, many novel concepts and achievements have been continuously made and shown to the public, while new problems have emerged at the same time, which need to be solved. In this paper, we give an overview of the development status of soft wearable robots for human movement assistance. On the basis of a clear definition, we perform a system classification according to the target assisted joint and attempt to describe the overall prototype design level in related fields. Additionally, it is necessary to sort out the latest research progress of key technologies such as structure, actuation, control and evaluation, thereby analyzing the design ideas and basic characteristics of them. Finally, we discuss the possible application fields, and propose the main challenges of this valuable research direction.
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Robótica , Dispositivos Eletrônicos Vestíveis , Fenômenos Biomecânicos , Humanos , MovimentoRESUMO
Alzheimer's disease (AD) is characterized by the accumulation of amyloid-ß plaques and Tau tangles in brain tissues. Recent studies indicate that aberrant splicing and increased level of intron retention is linked to AD pathogenesis. Bioinformatic analysis revealed increased retention of intron 11 at the Tau gene in AD female dorsal lateral prefrontal cortex as compared to healthy controls, an observation validated by quantitative polymerase chain reaction using different brain tissues. Retention of intron 11 introduces a premature stop codon, resulting in the production of truncated Tau11i protein. Probing with customized antibodies designed against amino acids encoded by intron 11 showed that Tau11i protein is more enriched in AD hippocampus, amygdala, parietal, temporal, and frontal lobe than in healthy controls. This indicates that Tau messenger RNA with the retained intron is translated in vivo instead of being subjected to nonsense-mediated decay. Compared to full-length Tau441 isoform, ectopically expressed Tau11i forms higher molecular weight species, is enriched in Sarkosyl-insoluble fraction, and exhibits greater protein stability in cycloheximide assay. Stably expressed Tau11i also shows weaker colocalization with α-tubulin of microtubule network in human mature cortical neurons as compared to Tau441. Endogenous Tau11i is enriched in Sarkosyl-insoluble fraction in AD hippocampus and forms aggregates that colocalize weakly with Tau4R fibril-like structure in AD temporal lobe. The elevated level of Tau11i protein in AD brain tissues tested, coupled with biochemical properties resembling pathological Tau species suggest that retention of intron 11 of Tau gene might be an early biomarker of AD pathology.
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Doença de Alzheimer , Proteínas tau , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Biomarcadores/análise , Biomarcadores/metabolismo , Encéfalo/metabolismo , Diagnóstico Precoce , Feminino , Humanos , Íntrons/genética , Placa Amiloide/metabolismo , Proteínas tau/análise , Proteínas tau/genética , Proteínas tau/metabolismoRESUMO
BACKGROUND: The goals of our study are to determine the most recent trends in hospitalization, mortality, and healthcare utilization among hospitalized patients with alcohol-associated hepatitis (AH) in the United States. METHODS: We examined the recent prevalence, co-morbidities, and mortality in hospitalized AH patients in the United States based on the available National Inpatient Sample (NIS) data (2015 to 2019) using appropriate International Classification of Diseases (ICD) codes. We reported our data as national estimates based on the discharge weighting variable (DISCWT). Logistic regression analyses were used to determine factors associated with mortality. RESULTS: We observed an increase in the total number of hospitalized AH patients from 110,135 in 2015 to 136,620 in 2019, which represented 386 per 100,000 total hospitalizations or 42 per 100,000 US population, which in 2019 was 328 million. Patients were a mean of 48 years old and the majority were White and male. The average length of stay was around 6 days with an overall in-hospital mortality that decreased from 4.19% in 2015 to 3.86% in 2019 (p-value for trend = <0.0001). During the 5-year study period, a total of 24,795 hospitalized AH patients died and 592,885 survived the hospital stay. Those who died were older, had a longer length of stay, and higher hospital charges during the stay. Mortality was significantly greater in patients who presented with complications from portal hypertension, those with acute renal failure, underlying cirrhosis, and sepsis. CONCLUSIONS: Our study documented the increasing prevalence of hospitalized AH patients and their significant associated healthcare costs and utilization. Our results underscore a continuing unmet and urgent need to identify effective therapies for hospitalized AH patients.
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Hepatite Alcoólica , Hospitalização , Hepatite Alcoólica/epidemiologia , Mortalidade Hospitalar , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Prevalência , Estados Unidos/epidemiologiaRESUMO
Epigenetic alterations occur during aging, but it remains unclear what epigenetic features are associated with the onset of physiological decline in animals. Nuclear lamin-B forms the filamentous meshwork underneath the nuclear envelope, providing the structural scaffold necessary for genome organization and gene regulation. We found that reduced level of nuclear lamin-B protein coincides with the decline in locomotor activity and stress resistance in young adult male Drosophila. Ubiquitous lamin-B expression improves locomotor activity of the male flies at the expense of lower stress resistance and shorten lifespan. This observation suggests that tissue-specific expression of lamin-B may regulate different aspects of animal physiology during aging. To test this hypothesis, specific GAL-4 lines were used to drive the expression of lamin-B in specific neuronal populations and muscle tissues in male flies. Ectopic expression of lamin-B in the dopaminergic neurons within the protocerebral anterior medial region of the brain improves the locomotor activity of the male flies with little impact on their stress responses and lifespan. Interestingly, age-dependent decrease in the level of lamin-B protein is independent of its mRNA expression. Instead, cellular thermal shift assay showed that lamin-B and CP190 insulator protein undergo significant change in their solubility during aging. This suggests that the increased solubility of lamin-B protein may contribute to its reduced stability and degradation during aging.
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Proteínas de Drosophila , Lamina Tipo B , Envelhecimento/genética , Animais , Núcleo Celular/metabolismo , Drosophila/genética , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Lamina Tipo A/metabolismo , Lamina Tipo B/metabolismo , Masculino , Proteínas Associadas aos Microtúbulos/metabolismo , Membrana Nuclear/metabolismo , Proteínas Nucleares/metabolismoRESUMO
The oxysterol sulfate, 25-hydroxycholesterol 3-sulfate (25HC3S), has been shown to play an important role in lipid metabolism, inflammatory response, and cell survival. However, the mechanism(s) of its function in global regulation is unknown. The current study investigates the molecular mechanism by which 25HC3S functions as an endogenous epigenetic regulator. To study the effects of oxysterols/sterol sulfates on epigenetic modulators, 12 recombinant epigenetic enzymes were used to determine whether 25HC3S acts as their endogenous ligand. The enzyme kinetic study demonstrated that 25HC3S specifically inhibited DNA methyltransferases (DNMTs), DNMT1, DNMT3a, and DNMT3b with IC50 of 4.04, 3.03, and 9.05 × 10-6 M, respectively. In human hepatocytes, high glucose induces lipid accumulation by increasing promoter CpG methylation of key genes involved in development of nonalcoholic fatty liver diseases. Using this model, whole genome bisulfate sequencing analysis demonstrated that 25HC3S converts the 5mCpG to CpG in the promoter regions of 1,074 genes. In addition, we observed increased expression of the demethylated genes, which are involved in the master signaling pathways, including MAPK-ERK, calcium-AMP-activated protein kinase, and type II diabetes mellitus pathways. mRNA array analysis showed that the upregulated genes encoded for key elements of cell survival; conversely, downregulated genes encoded for key enzymes that decrease lipid biosynthesis. Taken together, our results indicate that the expression of these key elements and enzymes are regulated by the demethylated signaling pathways. We summarized that 25HC3S DNA demethylation of 5mCpG in promoter regions is a potent regulatory mechanism.
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Ésteres do Colesterol , HidroxicolesteróisRESUMO
NELF-mediated pausing of RNA polymerase II (RNAPII) constitutes a crucial step in transcription regulation. However, it remains unclear how control release of RNAPII pausing can affect the epigenome and regulate important aspects of animal physiology like aging. We found that NELF-A dosage regulates Drosophila healthspan: Halving NELF-A level in the heterozygous mutants or via neuronal-specific RNAi depletion improves their locomotor activity, stress resistance, and lifespan significantly. Conversely, NELF-A overexpression shortens fly lifespan drastically. Mechanistically, lowering NELF-A level facilitates the release of paused RNAPII for productive transcription of the heat-shock protein (Hsp) genes. The elevated HSPs expression in turn attenuates the accumulation of insoluble protein aggregates, reactive oxidative species, DNA damage and systemic inflammation in the brains of aging NELF-A depleted flies as compared to their control siblings. This pro-longevity effect is unique to NELF-A due to its higher expression level and more efficient pausing of RNAPII than other NELF subunits. Importantly, enhanced resistance to oxidative stress in NELF-A heterozygous mutants is highly conserved such that knocking down its level in human SH-SY5Y cells attenuates hydrogen peroxide-induced DNA damage and apoptosis. Depleting NELF-A reconfigures the epigenome through the maintenance of H3K9me2-enriched heterochromatin during aging, leading to the repression of specific retrotransposons like Gypsy-1 in the brains of NELF-A mutants. Taken together, we showed that the dosage of neuronal NELF-A affects multiple aspects of aging in Drosophila by regulating transcription of Hsp genes in the brains, suggesting that targeting transcription elongation might be a viable therapeutic strategy against age-onset diseases like neurodegeneration.
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Proteínas de Drosophila/fisiologia , Proteínas de Choque Térmico/biossíntese , Longevidade/genética , Proteínas de Ligação a RNA/fisiologia , Fatores de Transcrição/fisiologia , Envelhecimento , Animais , Linhagem Celular , Dano ao DNA , Drosophila/genética , Drosophila/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Regulação da Expressão Gênica , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Heterocromatina/metabolismo , Histonas/metabolismo , Humanos , Locomoção , Neurônios/metabolismo , Estresse Oxidativo , Agregados Proteicos , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Retroelementos , S-Adenosilmetionina/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transcrição GênicaAssuntos
Resistência à Insulina , Obesidade , Tartarugas , Animais , Insulina , Gordura Intra-Abdominal , Obesidade/terapia , RatosRESUMO
Tet3 regulates the dynamic balance between 5-methylcyotsine (5mC) and 5-hydroxymethylcytosine (5hmC) in DNA during brain development and homeostasis. However, it remains unclear how its functions are modulated in a context-dependent manner during neuronal differentiation. Here, we show that cyclin-dependent kinase 5 (cdk5) phosphorylates Tet3 at the highly conserved serine 1310 and 1379 residues within its catalytic domain, changing its in vitro dioxygenase activity. Interestingly, when stably expressed in Tet1, 2, 3 triple-knockout mouse embryonic stem cells (ESCs), wild-type Tet3 induces higher level of 5hmC and concomitant expression of genes associated with neurogenesis whereas phosphor-mutant (S1310A/S1379A) Tet3 causes elevated 5hmC and expression of genes that are linked to metabolic processes. Consistent with this observation, Tet3-knockout mouse ESCs rescued with wild-type Tet3 have higher level of 5hmC at the promoter of neuron-specific gene BRN2 when compared to cells that expressed phosphor-mutant Tet3. Wild-type and phosphor-mutant Tet3 also exhibit differential binding affinity to histone variant H2A.Z. The differential 5hmC enrichment and H2A.Z occupancy at BRN2 promoter is correlated with higher gene expression and more efficient neuronal differentiation of ESCs that expressed wild-type Tet3. Taken together, our results suggest that cdk5-mediated phosphorylation of Tet3 is required for robust activation of neuronal differentiation program.
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Quinase 5 Dependente de Ciclina/genética , Citidina/análogos & derivados , Dioxigenases/genética , Neurogênese/genética , 5-Metilcitosina/análogos & derivados , 5-Metilcitosina/metabolismo , Animais , Diferenciação Celular/genética , Citidina/genética , Citidina/metabolismo , Metilação de DNA/genética , Proteínas de Ligação a DNA , Regulação da Expressão Gênica no Desenvolvimento/genética , Histonas/genética , Camundongos , Camundongos Knockout , Células-Tronco Embrionárias Murinas , Proteínas do Tecido Nervoso/genética , Neurônios/metabolismo , Fatores do Domínio POU/genética , Fosforilação , Regiões Promotoras GenéticasRESUMO
Intron retention (IR) by alternative splicing is a conserved regulatory mechanism that can affect gene expression and protein function during adult development and age-onset diseases. However, it remains unclear whether IR undergoes spatial or temporal changes during different stages of aging or neurodegeneration like Alzheimer's disease (AD). By profiling the transcriptome of Drosophila head cells at different ages, we observed a significant increase in IR events for many genes during aging. Differential IR affects distinct biological functions at different ages and occurs at several AD-associated genes in older adults. The increased nucleosome occupancy at the differentially retained introns in young animals suggests that it may regulate the level of IR during aging. Notably, an increase in the number of IR events was also observed in healthy older mouse and human brain tissues, as well as in the cerebellum and frontal cortex from independent AD cohorts. Genes with differential IR shared many common features, including shorter intron length, no perturbation in their mRNA level, and enrichment for biological functions that are associated with mRNA processing and proteostasis. The differentially retained introns identified in AD frontal cortex have higher GC content, with many of their mRNA transcripts showing an altered level of protein expression compared to control samples. Taken together, our results suggest that an increased IR is an conserved signature that is associated with aging. By affecting pathways involved in mRNA and protein homeostasis, changes of IR pattern during aging may regulate the transition from healthy to pathological state in late-onset sporadic AD.
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Envelhecimento/genética , Doença de Alzheimer/genética , Íntrons/genética , Doença de Alzheimer/patologia , Animais , Encéfalo/patologia , Drosophila , Humanos , Camundongos , TranscriptomaAssuntos
Quinase 5 Dependente de Ciclina/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Locomoção/genética , Proteínas Associadas aos Microtúbulos/genética , Proteínas Nucleares/genética , Animais , Animais Geneticamente Modificados/genética , Animais Geneticamente Modificados/crescimento & desenvolvimento , Elementos de DNA Transponíveis/genética , Drosophila melanogaster/crescimento & desenvolvimento , Feminino , Humanos , FosforilaçãoRESUMO
BACKGROUND: Gesneriaceae family contains numerous species endemic to China, and many of them are listed as endangered species. There is a need for a simple and efficient method for long-term conservation of these species. OBJECTIVE: The study aimed to establish an efficient procedure for cryopreserving Paraisometrum mileense, a critically endangered species endemic to Yunnan, China. METHODS: Effects of sucrose concentration of preculture solution, duration of sucrose preculture, duration of plant vitrification solution 2 (PVS2) treatment, and cold acclimation on regeneration of cryopreserved adventitious shoot tips (ASTs) were assessed. RESULTS AND CONCLUSION: Among different sucrose preculture regimes tested, preculture with 0.3M sucrose for 24h resulted in best regeneration of cryopreserved ASTs. PVS2 treatment also affected regeneration considerably with the maximum survival of ASTs after incubation in PVS2 for 90 min at 0 degrees C. With the optimised parameters, the level of shoot regeneration from cryopreserved ASTs reached 86%. No morphological abnormalities were observed during one year's growth of the plantlets developing from cryopreserved ASTs. Procedure established in this research is a promising technique for the cryopreservation of ASTs of this species.
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Criopreservação , Lamiaceae/fisiologia , Brotos de Planta/fisiologia , Regeneração , Vitrificação , China , Conservação dos Recursos Naturais , Crioprotetores/farmacologia , Espécies em Perigo de Extinção , Excipientes/farmacologia , Lamiaceae/efeitos dos fármacos , Brotos de Planta/efeitos dos fármacos , Sacarose/farmacologia , Fatores de TempoRESUMO
In ordinary multivariate calibration methods, when the calibration set is determined to build the model describing the relationship between the dependent variables and the predictor variables, each sample in the calibration set makes the same contribution to the model, where the difference of representativeness between the samples is ignored. In this paper, by introducing the concept of weighted sampling into partial least squares (PLS), a new multivariate regression method, optimized sample-weighted PLS (OSWPLS) is proposed. OSWPLS differs from PLS in that it builds a new calibration set, where each sample in the original calibration set is weighted differently to account for its representativeness to improve the prediction ability of the algorithm. A recently suggested global optimization algorithm, particle swarm optimization (PSO) algorithm is used to search for the best sample weights to optimize the calibration of the original training set and the prediction of an independent validation set. The proposed method is applied to two real data sets and compared with the results of PLS, the most significant improvement is obtained for the meat data, where the root mean squared error of prediction (RMSEP) is reduced from 3.03 to 2.35. For the fuel data, OSWPLS can also perform slightly better or no worse than PLS for the prediction of the four analytes. The stability and efficiency of OSWPLS is also studied, the results demonstrate that the proposed method can obtain desirable results within moderate PSO cycles.