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1.
Artículo en Inglés | MEDLINE | ID: mdl-38641484

RESUMEN

BACKGROUND AND OBJECTIVES: The 1 + X certificate system, introduced in China in 2019, integrates academic credentials with vocational skill certificates to meet the heightened demand for skilled talents in the growing economy. This study aims to innovate and evaluate the vocational pharmaceutical education system under the 1 + X certificate framework, specifically addressing the gap between theoretical education and workplace requirements. MATERIALS AND METHODS: A retrospective observational approach analyzed 490 pharmacy students over two academic years. The 2021 cohort underwent 1 + X integrated education, while the 2020 cohort followed conventional education. We collaborated closely with industry partners to identify and compile typical job competencies, formulating work projects aligned with industry demands. Combining the skill level standards and assessment content of "1+X Pharmaceutical Purchasing and Sales" and "1+X Pharmaceutical Preparation", we revised the course standards, incorporating typical work projects into the 2021 pharmacy professional teaching curriculum. This constituted the fundamental content of the 1 + X education reform. Statistical analysis compared course scores and 1 + X certificate examination performance. RESULTS: The 2021 cohort, under the 1 + X educational model, demonstrated higher average scores in pharmacy courses, with significant improvements in pharmacology (1 + X vs. Traditional education: 58.40 ± 14.20 vs. 53.44 ± 14.67), clinical pharmacotherapy (72.74 ± 10.28 vs. 63.15 ± 11.03), and pharmaceutical distribution and marketing (79.34 ± 10.96 vs. 67.50 ± 15.82). 1 + X certificate pass rates and satisfaction with the model were also higher than the 2020 cohort. CONCLUSION: The 1 + X certificate system is useful for developing talent in Chinese vocational education, effectively integrating assessments with industry standards. Future research should aim at evaluating long-term outcomes and improving quantitative skills assessments for enhanced effectiveness.

2.
J Neuroinflammation ; 21(1): 97, 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38627787

RESUMEN

The unfavorable prognosis of many neurological conditions could be attributed to limited tissue regeneration in central nervous system (CNS) and overwhelming inflammation, while liver X receptor (LXR) may regulate both processes due to its pivotal role in cholesterol metabolism and inflammatory response, and thus receives increasing attentions from neuroscientists and clinicians. Here, we summarize the signal transduction of LXR pathway, discuss the therapeutic potentials of LXR agonists based on preclinical data using different disease models, and analyze the dilemma and possible resolutions for clinical translation to encourage further investigations of LXR related therapies in CNS disorders.


Asunto(s)
Enfermedades del Sistema Nervioso Central , Receptores Nucleares Huérfanos , Humanos , Receptores X del Hígado , Receptores Nucleares Huérfanos/metabolismo , Sistema Nervioso Central/metabolismo , Inflamación , Enfermedades del Sistema Nervioso Central/tratamiento farmacológico
3.
Front Oncol ; 13: 1322403, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38107067

RESUMEN

Acute myeloid leukemia (AML) is a malignant disease of myeloid hematopoietic stem/progenitor cells characterized by the abnormal proliferation of primitive and naive random cells in the bone marrow and peripheral blood. Acute promyelocytic leukemia (APL) is a type (AML-M3) of AML. Most patients with APL have the characteristic chromosomal translocation t(15; 17)(q22; q12), forming PML::RARA fusion. The occurrence and progression of AML are often accompanied by the emergence of gene fusions such as PML::RARA, CBFß::MYH11, and RUNX1::RUNX1T1, among others. Gene fusions are the main molecular biological abnormalities in acute leukemia, and all fusion genes act as crucial oncogenic factors in leukemia. Herein, we report the first case of LYN::LINC01900 fusion transcript in AML with a promyelocytic phenotype and TP53 mutation. Further studies should address whether new protein products may result from this fusion, as well as the biological function of these new products in disease occurrence and progression.

4.
Front Mol Neurosci ; 16: 1251432, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38025264

RESUMEN

Background: Intracerebral hemorrhage (ICH) is the predominant type of hemorrhagic stroke with high mortality and disability. In other neurological conditions, the deposition of extracellular matrix (ECM) molecules is a prominent obstacle for regenerative processes and an enhancer of neuroinflammation. Whether ECM molecules alter in composition after ICH, and which ECM members may inhibit repair, remain largely unknown in hemorrhagic stroke. Methods: The collagenase-induced ICH mouse model and an autopsied human ICH specimen were investigated for expression of ECM members by immunofluorescence microscopy. Confocal image z-stacks were analyzed with Imaris 3D to assess the association of immune cells and ECM molecules. Sections from a mouse model of multiple sclerosis were used as disease and staining controls. Tissue culture was employed to examine the roles of ECM members on oligodendrocyte precursor cells (OPCs). Results: Among the lectican chondroitin sulfate proteoglycan (CSPG) members, neurocan but not aggrecan, versican-V1 and versican-V2 was prominently expressed in perihematomal tissue and lesion core compared to the contralateral area in murine ICH. Fibrinogen, fibronectin and heparan sulfate proteoglycan (HSPG) were also elevated after murine ICH while thrombospondin and tenascin-C was not. Confocal microscopy with Imaris 3D rendering co-localized neurocan, fibrinogen, fibronectin and HSPG molecules to Iba1+ microglia/macrophages or GFAP+ astrocytes. Marked differentiation from the multiple sclerosis model was observed, the latter with high versican-V1 and negligible neurocan. In culture, purified neurocan inhibited adhesion and process outgrowth of OPCs, which are early steps in myelination in vivo. The prominent expression of neurocan in murine ICH was corroborated in human ICH sections. Conclusion: ICH caused distinct alterations in ECM molecules. Among CSPG members, neurocan was selectively upregulated in both murine and human ICH. In tissue culture, neurocan impeded the properties of oligodendrocyte lineage cells. Alterations to the ECM in ICH may adversely affect reparative outcomes after stroke.

5.
Chemphyschem ; 24(21): e202300429, 2023 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-37534533

RESUMEN

Combustible gas-gas reactions usually do not occur spontaneously upon mixing without ignition or other triggers to lower the activation energy barrier. Nanobubbles, however, could provide such a possibility in solution under ambient conditions due to high inner pressure and catalytic radicals within their boundary layers. Herein, a tunable gas-gas reaction strategy via bulk nanobubble pathway is developed by tuning the interface charge of one type of bulk nanobubble and promoting its fusion and reaction with another, where the reaction-accompanied size and number concentration change of the bulk nanobubbles and the corresponding thermal effect clearly confirm the occurrence of the nanobubble-based H2 /O2 combustion. In addition, abundant radicals can be detected during the reaction, which is considered to be critical to ignite the gas reaction during the fusion of nanobubbles in water at room temperature. Therefore, the nanobubble-based gas-gas reactions provide a safe and efficient pathway to produce energy and synthesize new matter inaccessible under mild or ambient conditions.

6.
Cell ; 186(17): 3726-3743.e24, 2023 08 17.
Artículo en Inglés | MEDLINE | ID: mdl-37442136

RESUMEN

Elucidating the cellular organization of the cerebral cortex is critical for understanding brain structure and function. Using large-scale single-nucleus RNA sequencing and spatial transcriptomic analysis of 143 macaque cortical regions, we obtained a comprehensive atlas of 264 transcriptome-defined cortical cell types and mapped their spatial distribution across the entire cortex. We characterized the cortical layer and region preferences of glutamatergic, GABAergic, and non-neuronal cell types, as well as regional differences in cell-type composition and neighborhood complexity. Notably, we discovered a relationship between the regional distribution of various cell types and the region's hierarchical level in the visual and somatosensory systems. Cross-species comparison of transcriptomic data from human, macaque, and mouse cortices further revealed primate-specific cell types that are enriched in layer 4, with their marker genes expressed in a region-dependent manner. Our data provide a cellular and molecular basis for understanding the evolution, development, aging, and pathogenesis of the primate brain.


Asunto(s)
Corteza Cerebral , Macaca , Análisis de la Célula Individual , Transcriptoma , Animales , Humanos , Ratones , Corteza Cerebral/citología , Corteza Cerebral/metabolismo , Macaca/metabolismo , Transcriptoma/genética
7.
Stroke Vasc Neurol ; 8(6): 486-502, 2023 12 29.
Artículo en Inglés | MEDLINE | ID: mdl-37137522

RESUMEN

BACKGROUND: Inflammation-exacerbated secondary brain injury and limited tissue regeneration are barriers to favourable prognosis after intracerebral haemorrhage (ICH). As a regulator of inflammation and lipid metabolism, Liver X receptor (LXR) has the potential to alter microglia/macrophage (M/M) phenotype, and assist tissue repair by promoting cholesterol efflux and recycling from phagocytes. To support potential clinical translation, the benefits of enhanced LXR signalling are examined in experimental ICH. METHODS: Collagenase-induced ICH mice were treated with the LXR agonist GW3965 or vehicle. Behavioural tests were conducted at multiple time points. Lesion and haematoma volume, and other brain parameters were assessed using multimodal MRI with T2-weighted, diffusion tensor imaging and dynamic contrast-enhanced MRI sequences. The fixed brain cryosections were stained and confocal microscopy was applied to detect LXR downstream genes, M/M phenotype, lipid/cholesterol-laden phagocytes, oligodendrocyte lineage cells and neural stem cells. Western blot and real-time qPCR were also used. CX3CR1CreER: Rosa26iDTR mice were employed for M/M-depletion experiments. RESULTS: GW3965 treatment reduced lesion volume and white matter injury, and promoted haematoma clearance. Treated mice upregulated LXR downstream genes including ABCA1 and Apolipoprotein E, and had reduced density of M/M that apparently shifted from proinflammatory interleukin-1ß+ to Arginase1+CD206+ regulatory phenotype. Fewer cholesterol crystal or myelin debris-laden phagocytes were observed in GW3965 mice. LXR activation increased the number of Olig2+PDGFRα+ precursors and Olig2+CC1+ mature oligodendrocytes in perihaematomal regions, and elevated SOX2+ or nestin+ neural stem cells in lesion and subventricular zone. MRI results supported better lesion recovery by GW3965, and this was corroborated by return to pre-ICH values of functional rotarod activity. The therapeutic effects of GW3965 were abrogated by M/M depletion in CX3CR1CreER: Rosa26iDTR mice. CONCLUSIONS: LXR agonism using GW3965 reduced brain injury, promoted beneficial properties of M/M and facilitated tissue repair correspondent with enhanced cholesterol recycling.


Asunto(s)
Lesiones Encefálicas , Microglía , Ratones , Animales , Receptores X del Hígado/agonistas , Receptores X del Hígado/metabolismo , Microglía/metabolismo , Receptores Nucleares Huérfanos/agonistas , Receptores Nucleares Huérfanos/metabolismo , Imagen de Difusión Tensora , Macrófagos/metabolismo , Colesterol/metabolismo , Colesterol/farmacología , Hemorragia Cerebral/metabolismo , Inflamación , Lesiones Encefálicas/metabolismo , Hematoma
8.
Nanoscale ; 15(9): 4388-4396, 2023 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-36745395

RESUMEN

Interface engineering is a promising strategy to enhance the catalytic performance of electrocatalysts for the oxygen reduction reaction (ORR). However, it is still a challenge to modulate the size into a suitable range (e.g., nanocluster-scale) to make the most of the interface. Moreover, the explicit mechanism of the interface for enhancing catalytic performance is still elusive. Herein, a model catalyst (FeCu@NC) loaded with nanocluster-scaled Fe2O3/Cu interfaces was prepared by modulating the metal components of the precursor to explore the enhancement of interface engineering for the ORR. Benefiting from the synergistic effect of the strong interfacial coupling effects of Fe2O3/Cu and optimized microstructure, FeCu@NC exhibited superior ORR activity and zinc-air battery performance. Experimental and theoretical calculations revealed that the presence of the Fe2O3/Cu interface breaks the traditional cognition to endow the Cu atoms (intrinsically inferior for the ORR) with a slight positive charge, which serves as the active sites for the ORR. This study provides a novel insight into the design of advanced electrocatalysts for the ORR by interface engineering.

9.
Neurol Res ; 45(9): 796-803, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34112057

RESUMEN

OBJECTIVES: This article aimed to analyze the relationship between obesity and the efficacy of acute ischaemic stroke patients treated with IVT. BACKGROUND: Stroke causes morbidity and mortality in large numbers of individuals annually. Intravenous thrombolysis (IVT)with recombinant tissue plasminogen activator (r-tPA) is currently the only approved by the FDA for treatment of acute ischaemic stroke. Researchers have focused on studying the mechanisms associated with ischaemic stroke. Obesity is an established vascular risk factor with increasing prevalence and a huge impact on public health worldwide. It is an independent predictor for ischaemic stroke with a 4% risk increase for each unit augmentation in body mass index (BMI). Therefore, obese patients will constitute an increasing subgroup of candidates for IVT. However, its impact on prognosis in acute ischaemic stroke patients with intravenous thrombolysis did not reach a consensus conclusion. METHODS: Systematic literature search of PUBMED databases published before August 2020, was performed to identify studies addressing the role of obesity in acute ischaemic stroke patients treated with IVT. Studies included randomized clinical trials, observational studies, guideline statements, and review articles. CONCLUSIONS: Obesity may be related to long-term prognosis of large group of AIS patients treated with IVT. It depends on the scale of clinical study samples, follow-up time, and evaluation criteria.


Asunto(s)
Isquemia Encefálica , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Humanos , Isquemia Encefálica/complicaciones , Isquemia Encefálica/tratamiento farmacológico , Fibrinolíticos/uso terapéutico , Accidente Cerebrovascular Isquémico/tratamiento farmacológico , Obesidad/complicaciones , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/tratamiento farmacológico , Terapia Trombolítica/efectos adversos , Activador de Tejido Plasminógeno/uso terapéutico
10.
Front Mol Neurosci ; 15: 927334, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35782383

RESUMEN

Intracerebral hemorrhage (ICH) is a subtype of stroke that is characterized by high morbidity and mortality, for which clinical outcome remains poor. An extensive literature indicates that the release of ferrous iron from ruptured erythrocytes in the hematoma is a key pathogenic factor in ICH-induced brain injury. Deferoxamine is an FDA-approved iron chelator that has the capacity to penetrate the blood-brain barrier after systemic administration and binds to iron. Previous animal studies have shown that deferoxamine attenuates ICH-induced brain edema, neuronal death, and neurological deficits. This review summarizes recent progress of the mechanisms by which deferoxamine may alleviate ICH and discusses further studies on its clinical utility.

11.
Front Mol Neurosci ; 15: 927150, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35782389

RESUMEN

The destruction of the blood-brain barrier (BBB) after intracerebral hemorrhage (ICH) is associated with poor prognosis. Modulation of sphingosine 1-phosphate receptor (S1PR) may improve outcomes from ICH. Ozanimod (RPC-1063) is a newly developed S1PR regulator which can selectively modulate type 1/5 sphingosine receptors. Here, we studied the impact of Ozanimod on neuroprotection in an experimental mouse model of ICH, induced by injecting collagenase type VII into the basal ganglia. Ozanimod was administered by gavage 2 h after surgery and once a day thereafter until sacrifice. The results demonstrate that Ozanimod treatment improved neurobehavioral deficits in mice and decreased weight loss after ICH. Ozanimod significantly reduced the density of activated microglia and infiltrated neutrophils in the perihematoma region. Furthermore, Ozanimod reduced hematoma volume and water content of the ICH brain. The results of TUNEL staining indicate that Ozanimod mitigated brain cell death. The quantitative data of Evans blue (EB) staining showed that Ozanimod reduced EB dye leakage. Overall, Ozanimod reduces the destruction of the BBB and exert neuroprotective roles following ICH in mice.

12.
Dalton Trans ; 51(30): 11363-11371, 2022 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-35816017

RESUMEN

Metal-organic frameworks (MOFs) have been widely used as precursors to derive carbon-based electrocatalysts for the oxygen reduction reaction (ORR) due to their high porosity and tunable chemical composition/structure. However, the influence of MOF type on the structure and further ORR activity of derived metal-free carbon catalysts is still elusive. In the present work, a series of different Zn-based MOFs were employed as precursors to explore this issue. Meanwhile, prepare N-doped metal-free carbon catalysts were prepared for the ORR under the activation of sacrificial urea (which is effective to enhance the ORR activity of carbon-based catalysts). By analyzing the intermediates during pyrolysis, it is found that the decisive role of MOF types on the doped N and the morphology of derived carbon catalysts was played by the Zn coordination environment of MOFs and its reactivity with the decomposition intermediate of urea. Although the structure and porosity of derived carbon catalysts from different MOFs are very different, they all showed superior ORR activity and Zn-air battery performance up to 20 wt% Pt/C benchmark catalysts. From the above analyses, the combination of urea and compounded Zn is also a promising activation method for the preparation of highly-efficient metal-free carbon electrocatalysts.

13.
Biomolecules ; 12(7)2022 06 23.
Artículo en Inglés | MEDLINE | ID: mdl-35883430

RESUMEN

Recent advances in single-cell transposase-accessible chromatin using a sequencing assay (scATAC-seq) allow cellular heterogeneity dissection and regulatory landscape reconstruction with an unprecedented resolution. However, compared to bulk-sequencing, its ultra-high missingness remarkably reduces usable reads in each cell type, resulting in broader, fuzzier peak boundary definitions and limiting our ability to pinpoint functional regions and interpret variant impacts precisely. We propose a weakly supervised learning method, scEpiLock, to directly identify core functional regions from coarse peak labels and quantify variant impacts in a cell-type-specific manner. First, scEpiLock uses a multi-label classifier to predict chromatin accessibility via a deep convolutional neural network. Then, its weakly supervised object detection module further refines the peak boundary definition using gradient-weighted class activation mapping (Grad-CAM). Finally, scEpiLock provides cell-type-specific variant impacts within a given peak region. We applied scEpiLock to various scATAC-seq datasets and found that it achieves an area under receiver operating characteristic curve (AUC) of ~0.9 and an area under precision recall (AUPR) above 0.7. Besides, scEpiLock's object detection condenses coarse peaks to only ⅓ of their original size while still reporting higher conservation scores. In addition, we applied scEpiLock on brain scATAC-seq data and reported several genome-wide association studies (GWAS) variants disrupting regulatory elements around known risk genes for Alzheimer's disease, demonstrating its potential to provide cell-type-specific biological insights in disease studies.


Asunto(s)
Epigenómica , Estudio de Asociación del Genoma Completo , Cromatina/genética , Epigénesis Genética , Aprendizaje Automático Supervisado
14.
J Nanobiotechnology ; 20(1): 223, 2022 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-35549949

RESUMEN

Tumor microenvironment (TME), characterized by high glutathione (GSH), high hydrogen peroxide (H2O2) and acidic pH levels, is favorable for the growth, invasion and metastasis of cancer cells. Taking advantage of the specific characteristics of tumors, TME-responsive GCBD NPs are designed to deliver nanoscale coordination polymers (NCPs, GA-Cu) and chemotherapy drugs (doxorubicin, DOX) based on bovine serum albumin (BSA) nanocarriers into cancer cells for combined chemodynamic therapy (CDT) and chemotherapy. In an acidic environment, GCBD NPs could release approximately 90% copper ions, which can not only consume overexpressed GSH to modulate the TME but can also react with endogenous H2O2 in a Fenton-like reaction to achieve the CDT effect. Meanwhile, the released DOX could enter the nucleus of tumor cells and affect their proliferation to achieve efficient chemotherapy. Both in vitro and in vivo experiments showed that GCBD NPs had good biosafety and could effectively inhibit the growth of cancer cells. GCBD NPs are promising as a biocompatible nanoplatform to exploit TME characteristics for combined chemo and chemodynamic therapy, providing a novel strategy to eradicate tumors with high efficiency and specificity.


Asunto(s)
Neoplasias , Microambiente Tumoral , Línea Celular Tumoral , Doxorrubicina/química , Glutatión , Humanos , Peróxido de Hidrógeno , Neoplasias/tratamiento farmacológico , Albúmina Sérica Bovina/uso terapéutico
15.
Front Big Data ; 5: 878716, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35620565

RESUMEN

Domain adaptation aims at reducing the domain shift between a labeled source domain and an unlabeled target domain, so that the source model can be generalized to target domains without fine tuning. In this paper, we propose to evaluate the cross-domain transferability between source and target samples by domain prediction uncertainty, which is quantified via Wasserstein gradient flows. Further, we exploit it for reweighting the training samples to alleviate the issue of domain shift. The proposed mechanism provides a meaningful curriculum for cross-domain transfer and adaptively rules out samples that contain too much domain specific information during domain adaptation. Experiments on several benchmark datasets demonstrate that our reweighting mechanism can achieve improved results in both balanced and partial domain adaptation.

16.
Front Immunol ; 13: 844163, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35401553

RESUMEN

Intracerebral hemorrhage (ICH) is an important subtype of stroke with an unsatisfactory prognosis of high mortality and disability. Although many pre-clinical studies and clinical trials have been performed in the past decades, effective therapy that meaningfully improve prognosis and outcomes of ICH patients is still lacking. An active area of research is towards alleviating secondary brain injury after ICH through neuroprotective pharmaceuticals and in which minocycline is a promising candidate. Here, we will first discuss new insights into the protective mechanisms of minocycline for ICH including reducing iron-related toxicity, maintenance of blood-brain barrier, and alleviating different types of cell death from preclinical data, then consider its shortcomings. Finally, we will review clinical trial perspectives for minocycline in ICH. We hope that this summary and discussion about updated information on minocycline as a viable treatment for ICH can facilitate further investigations.


Asunto(s)
Lesiones Encefálicas , Fármacos Neuroprotectores , Barrera Hematoencefálica/metabolismo , Hemorragia Cerebral/tratamiento farmacológico , Hemorragia Cerebral/metabolismo , Humanos , Minociclina/uso terapéutico , Fármacos Neuroprotectores/uso terapéutico
17.
Front Neurol ; 13: 861843, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35370878

RESUMEN

Matrix metalloproteinases (MMPs) are physiologically expressed in the central nervous system in neurons, astrocytes and microglia, and their aberrant elevation contributes to a number of diseases. Amongst the MMP members, MMP-9 has generated considerable attention because of its possible involvement in inflammatory responses, blood-brain barrier permeability, the regulation of perineuronal nets, demyelination, and synaptic long-term potentiation. Emerging evidence indicate an association between MMP-9 and the syndrome of depression. This review provides an updated and comprehensive summary of the probable roles of MMP-9 in depression with an emphasis on the mechanisms and potential of MMP-9 as a biomarker of depression.

18.
Front Cell Neurosci ; 16: 799753, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35185473

RESUMEN

Intracerebral hemorrhage (ICH) is a devastating form of stroke with high rates of mortality and morbidity. It induces cell death that is responsible for neurological deficits postinjury. There are no therapies that effectively mitigate cell death to treat ICH. This review aims to summarize our knowledge of ICH-induced cell death with a focus on apoptosis and necrosis. We also discuss the involvement of ICH in recently described modes of cell death including necroptosis, pyroptosis, ferroptosis, autophagy, and parthanatos. We summarize treatment strategies to mitigate brain injury based on particular cell death pathways after ICH.

19.
Anal Bioanal Chem ; 414(15): 4401-4408, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35175388

RESUMEN

The widespread use and increased exposure of nanoparticles call for technology to quantify their concentration and size distribution in biological matrices. As ex situ evaluation, facile extraction with high fidelity and efficiency is critical. In this work, single particle inductively coupled plasma mass spectrometry (spICP-MS) was used for nanoparticle number and distribution analysis, where a facile and highly efficient mechanically assisted alkaline digestion has been developed to extract nanoparticles at low alkali concentration. The optimization was performed using chicken tissues in vitro mixed with 30 nm gold nanoparticles, mixture of 30 nm and 60 nm gold nanoparticles, and 45 nm silver nanoparticles, respectively, which is, then, mechanically ground to form tissue homogenate and 2% TMAH is added. The nanoparticles are extracted with a recovery of more than 94% for all the spiked nanoparticle tissue samples. The extraction method has also been attempted to be applied to extract single-sized gold nanoparticles from various organs of mice mixed in vivo with the nanoparticles through intravenous injection, and led to consistent results with acid digestion. Mice injected intravenously with double-sized gold nanoparticle mixture were also studied, further showing that gold nanoparticles of 30 nm and 60 nm have no significant difference in their biodistribution in the same organ. To the best of our knowledge, this is the first attempt for multiple nanoparticles being extracted simultaneously and measured quantitatively from various organs, such as the heart, liver, spleen, lungs, and kidneys. We believe this method is beneficial to the safety assessment and toxicokinetics studies for nanoparticles in tissues.


Asunto(s)
Nanopartículas del Metal , Nanopartículas , Animales , Oro/química , Nanopartículas del Metal/química , Ratones , Tamaño de la Partícula , Plata/química , Distribución Tisular
20.
Bioinformatics ; 38(6): 1607-1614, 2022 03 04.
Artículo en Inglés | MEDLINE | ID: mdl-34999749

RESUMEN

MOTIVATION: Rapidly generated scRNA-seq datasets enable us to understand cellular differences and the function of each individual cell at single-cell resolution. Cell-type classification, which aims at characterizing and labeling groups of cells according to their gene expression, is one of the most important steps for single-cell analysis. To facilitate the manual curation process, supervised learning methods have been used to automatically classify cells. Most of the existing supervised learning approaches only utilize annotated cells in the training step while ignoring the more abundant unannotated cells. In this article, we proposed scPretrain, a multi-task self-supervised learning approach that jointly considers annotated and unannotated cells for cell-type classification. scPretrain consists of a pre-training step and a fine-tuning step. In the pre-training step, scPretrain uses a multi-task learning framework to train a feature extraction encoder based on each dataset's pseudo-labels, where only unannotated cells are used. In the fine-tuning step, scPretrain fine-tunes this feature extraction encoder using the limited annotated cells in a new dataset. RESULTS: We evaluated scPretrain on 60 diverse datasets from different technologies, species and organs, and obtained a significant improvement on both cell-type classification and cell clustering. Moreover, the representations obtained by scPretrain in the pre-training step also enhanced the performance of conventional classifiers, such as random forest, logistic regression and support-vector machines. scPretrain is able to effectively utilize the massive amount of unlabeled data and be applied to annotating increasingly generated scRNA-seq datasets. AVAILABILITY AND IMPLEMENTATION: The data and code underlying this article are available in scPretrain: Multi-task self-supervised learning for cell type classification, at https://github.com/ruiyi-zhang/scPretrain and https://zenodo.org/record/5802306. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Asunto(s)
Bosques Aleatorios , Análisis de la Célula Individual , Análisis de la Célula Individual/métodos , Análisis por Conglomerados , Máquina de Vectores de Soporte
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