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1.
Small ; 20(11): e2304773, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37936335

RESUMO

Practical applications of synthetic self-propelled nano and microparticles for microrobotics, targeted drug delivery, and manipulation at the nanoscale are rapidly expanding. However, fabrication limitations often hinder progress, resulting in relatively simple shapes and limited functionality. Here, taking advantage of 3D nanoscale printing, chiral micropropellers powered by the hydrogen peroxide reduction reaction are fabricated. Due to their chirality, the propellers exhibit multifunctional behavior controlled by an applied magnetic field: spinning in place (loitering), directed migration in the prescribed direction, capture, and transport of polymer cargo particles. Design parameters of the propellers are optimized by computation modeling based on mesoscale molecular dynamics. It is predicted by computer simulations, and confirmed experimentally, that clockwise rotating propellers attract each other and counterclockwise repel. These results shed light on how chirality and shape optimization enhance the functionality of synthetic autonomous micromachines.

2.
J Environ Manage ; 352: 120033, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38218168

RESUMO

Saline-alkali soil poses significant chanllenges to sustainable development of agriculture. Although biochar is commonly used as a soil organic amendment, its microbial remediation mechanism on saline-alkali soil requires further confirmation. To address this, we conducted a pot experiment using cotton seedlings to explore the potential remediation mechanism of rice straw biochar (BC) at three different levels on saline-alkaline soil. The results showed that adding of 2% biochar greatly improved the quality of saline-alkaline soil by reducing pH levels, electrical conductivity (EC), and water-soluble ions. Moreover, biochar increased the soil organic matter (SOM), nutrient availability and extracellular enzyme activity. Interestingly, it also reduced soil salinity and salt content in various cotton plant tissues. Additionally, biochar had a notable impact on the composition of the microbial community, causing changes in soil metabolic pathways. Notably, the addition of biochar promoted the growth and metabolism of dominant salt-tolerant bacteria, such as Proteobacteria, Bacteroidota, Acidobacteriota, and Actinobacteriota. By enhancing the positive correlation between microorganisms and metabolites, biochar alleviated the inhibitory effect of salt ions on microorganisms. In conclusion, the incorporation of biochar significantly improves the soil microenvironment, reduces soil salinity, and shows promise in ameliorating saline-alkaline soil conditions.


Assuntos
Álcalis , Microbiota , Solo/química , Carvão Vegetal , Íons
3.
Health Econ ; 32(3): 541-557, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36377693

RESUMO

This paper estimates the effect of in utero exposure to adverse events on late life diabetes, cardiovascular disease risks and cognition deficiency. We merge data on the regional violence during the Cultural Revolution and the excessive death rates during the Chinese Great Famine with data from the China Health and Retirement Longitudinal Study survey. Results show that female babies who were exposed in utero to the famine have higher diabetes risks, while male babies who were exposed to the Cultural Revolution are shown to have lower cognitive abilities.


Assuntos
Efeitos Tardios da Exposição Pré-Natal , Humanos , Masculino , Feminino , Estudos Longitudinais , Efeitos Tardios da Exposição Pré-Natal/epidemiologia , Fome Epidêmica , China/epidemiologia , Aposentadoria
4.
Environ Res ; 231(Pt 3): 116217, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37245574

RESUMO

The sole application of nitrogen (N) fertilizer with lower N2O emission potential or combined with biochar may help for mitigating N2O production. However, how biochar applied with various inorganic N fertilizers affected N2O emission in acidic soil remains unclear. Thus, we examined N2O emission, soil N dynamics and relating nitrifiers (i.e., ammonia-oxidizing archaea, AOA) in acidic soil. The study contained three N fertilizers (including NH4Cl, NaNO3, NH4NO3) and two biochar application rates (i.e., 0% and 0.5%). The results indicated that the alone application of NH4Cl produced more N2O. Meanwhile, the co-application of biochar and N fertilizers enhanced N2O emission as well, especially in the combined treatment of biochar and NH4NO3. Soil pH was decreased with the application of various N fertilizers, especially with NH4Cl, and the average decrease rate was 9.6%. Meanwhile, correlation analysis showed a negative relationship between N2O and pH, dramatically, which might indicate that the alteration of pH was one factor relating to N2O emission. However, there was no difference between the same N addition treatments with or without biochar on pH. Interestingly, in the combined treatment of biochar and NH4NO3, the lowest net nitrification rate and net mineralization rate appeared during days 16-23. Meanwhile, the highest emission rate of N2O in the same treatment also appeared during days 16-23. The accordance might indicate that N transformation alteration was another factor relating to N2O emissions. In addition, compared to NH4NO3 alone application, co-applied with biochar had a lower content of Nitrososphaera-AOA, which was a main contributor to nitrification. The study emphasizes the importance of using a suitable form of N fertilizers and further indicates that two factors, namely alteration of pH and N transformation rate, are related to N2O emission. Moreover, in future studies, it is necessary to explore the soil N dynamics controlled by microorganisms.


Assuntos
Fertilizantes , Solo , Solo/química , Fertilizantes/análise , Nitrogênio , Óxido Nitroso , Archaea , Agricultura/métodos
5.
J Environ Manage ; 345: 118796, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37579602

RESUMO

In arable soils, anthropogenic activities such as fertilizer applications have intensified soil acidification in recent years. This has resulted in frequent environmental problems such as aluminum (Al) and H+ stress, which negatively impact crop yields and quality in acidic soils. Biochar, as a promising soil conditioner, has attracted much attention globally. The present study was conducted in a greenhouse by setting up 2% biochar rate to investigate how biochar relieves Al3+ hazards in acidic soil by affecting soil quality, soil environment, and soil microbiomes. The addition of biochar significantly improved soil fertility and enzyme activities, which were attributed to its ability to enhance the utilization of soil carbon sources by influencing the activity of soil microorganisms. Moreover, the Al3+ contents were significantly decreased by 66.61-88.83% compared to the C0 level (without biochar treatment). In particular, the results of the 27Al NMR suggested that forms of AlVI (Al(OH)2+, Al(OH)+ 2, and Al3+) were increased by 88.69-100.44% on the surface of biochar, reducing the Al3+ stress on soil health. The combination of biochar and nitrogen (N) fertilizer contributed to the augmentation of bacterial diversity. The application of biochar and N fertilizer increased the relative abundance of the majority of bacterial species. Additionally, the application of biochar and N fertilizer had a significant impact on soil microbial metabolism, specifically in the biosynthesis of secondary metabolites (lipids and organic acids) and carbon metabolic ability. In conclusion, biochar can enhance soil microbial activity and improve the overall health of acidic soil by driving microbial metabolism. This study offers both theoretical and technical guidance for enhancing biochar in acidified soil and promoting sustainable development in farmland production.


Assuntos
Alumínio , Solo , Solo/química , Fertilizantes , Carvão Vegetal/química , Carbono , Ácidos , Nitrogênio/análise
6.
J Environ Manage ; 347: 119045, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37778069

RESUMO

In order to explore the alteration of N transformation and N2O emissions in acid soil with the co-application of straw and different types of nitrogen (N) fertilizers, an incubation experiment was carried out for 40 days. There are totally five treatments in the study: (a) without straw and N fertilizer (N0), (b) straw alone application (SN0), (c) straw with NH4Cl (SN1), (d) straw with NaNO3 (SN2), and (e) straw with NH4NO3 (SN3). N2O emissions, soil physicochemical properties, and abundance/activity of ammonia-oxidizing archaea (AOA) were measured. The results showed that the combined application of straw and N enhanced N2O emissions, particularly, SN2 and SN3 treatments. Moreover, the soil pH was lower in co-application treatments and the average decreasing rate was 9.69%. Specially, the pH was lowest in the SN1 treatment. The results of correlation analysis indicated a markedly negative relationship between pH and N2O, as well as a negative relationship between pH and net mineralization rate. These findings suggest that pH alteration can affect the N transformation process in soil and thus influence N2O emissions. In addition, the dominant AOA at the genus level in the SN2 treatment was Nitrosopumilus, and Candidatus nitrosocosmicus in the SN3 treatment. The reshaped AOA structure can serve as additional evidence of the changes in the N transformation process. In conclusion, as the return of straw, the cumulation of N2O from arable acid soil depends on the form of N fertilizer. It is also important to consider how N fertilizer is applied to reduce the possibility of N being lost in the soil as gas.


Assuntos
Fertilizantes , Solo , Solo/química , Fertilizantes/análise , Nitrogênio/análise , Óxido Nitroso/análise , Archaea , Agricultura
7.
Hum Brain Mapp ; 43(17): 5167-5179, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-35751551

RESUMO

Studies on functional and structural changes in the primary somatosensory cortex (S1) have provided important insights into neural mechanisms underlying several chronic pain conditions. However, the role of S1 plasticity in postherpetic neuralgia (PHN) remains elusive. Combining psychophysics and magnetic resonance imaging (MRI), we investigated whether pain in PHN patients is linked to S1 reorganization as compared with healthy controls. Results from voxel-based morphometry showed no structural differences between groups. To characterize functional plasticity, we compared S1 responses to noxious laser stimuli of a fixed intensity between both groups and assessed the relationship between S1 activation and spontaneous pain in PHN patients. Although the intensity of evoked pain was comparable in both groups, PHN patients exhibited greater activation in S1 ipsilateral to the stimulated hand. Pain-related activity was identified in contralateral superior S1 (SS1) in controls as expected, but in bilateral inferior S1 (IS1) in PHN patients with no overlap between SS1 and IS1. Contralateral SS1 engaged during evoked pain in controls encoded spontaneous pain in patients, suggesting functional S1 reorganization in PHN. Resting-state fMRI data showed decreased functional connectivity between left and right SS1 in PHN patients, which scaled with the intensity of spontaneous pain. Finally, multivariate pattern analyses (MVPA) demonstrated that BOLD activity and resting-state functional connectivity of S1 predicted within-subject variations of evoked and spontaneous pain intensities across groups. In summary, functional reorganization in S1 might play a key role in chronic pain related to PHN and could be a potential treatment target in this patient group.


Assuntos
Dor Crônica , Neuralgia Pós-Herpética , Humanos , Neuralgia Pós-Herpética/diagnóstico por imagem , Córtex Somatossensorial/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Medição da Dor/métodos
8.
BMC Plant Biol ; 22(1): 2, 2022 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-34979911

RESUMO

BACK GROUND: MYB Transcription factors (TFs) are most imperative and largest gene family in plants, which participate in development, metabolism, defense, differentiation and stress response. The MYB TFs has been studied in various plant species. However, comprehensive studies of MYB gene family in the sweet cherry (Prunus avium L.) are still unknown. RESULTS: In the current study, a total of 69 MYB genes were investigated from sweet cherry genome and classified into 28 subfamilies (C1-C28 based on phylogenetic and structural analysis). Microcollinearity analysis revealed that dispersed duplication (DSD) events might play an important role in the MYB genes family expansion. Chromosomal localization, the synonymous (Ks) and nonsynonymous (Ka) analysis, molecular characteristics (pI, weight and length of amino acids) and subcellular localization were accomplished using several bioinformatics tools. Furthermore, the members of distinct subfamilies have diverse cis-acting regions, conserved motifs, and intron-exon architectures, indicating functional heterogeneity in the MYB family. Moreover, the transcriptomic data exposed that MYB genes might play vital role in bud dormancy. The quantitative real-time qRT-PCR was carried out and the expression pattern indicated that MYB genes significantly expressed in floral bud as compared to flower and fruit. CONCLUSION: Our comprehensive findings provide supportive insights into the evolutions, expansion complexity and functionality of PavMYB genes. These PavMYB genes should be further investigated as they seem to be brilliant candidates for dormancy manipulation in sweet cherry.


Assuntos
Flores/crescimento & desenvolvimento , Frutas/crescimento & desenvolvimento , Proteínas de Plantas/genética , Prunus avium/genética , Fatores de Transcrição/genética , Flores/genética , Frutas/genética , Família Multigênica , Proteínas de Plantas/metabolismo , Prunus avium/crescimento & desenvolvimento , Prunus avium/metabolismo , Fatores de Transcrição/metabolismo
9.
Nanotechnology ; 34(1)2022 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-36191554

RESUMO

In this study, reduced graphene oxide (rGO) were subject to ultrasonic treatment to acquire varied morphologies, and the enzymatic glucose sensors were constructed by coating the rGO onto indium tin oxide electrodes and physically linking glucose oxidase to the rGO coatings. The effects of the surface morphologies of the rGO coatings on the interfacial characteristics and the electro-catalytic capacity of the enzymatic glucose sensors were systematically investigated. It turns out that, the rGO coating with a rough surface is more hydrophilic, and exhibits uniform glucose oxidase adsorption and higher electron migration rate at the solid/liquid interface between the analytical liquid and the working electrode. As a result, the corresponding glucose sensor shows excellent electro-catalytic capacity towards glucose with a broader linear range of 0-10.0 mM, a higher sensitivity of 38.9µA·mM-1·cm-2, and a lower detection limit of 0.1µM (signal-to-noise ratio of 3). Additionally, the as-prepared glucose sensor exhibits excellent accuracy for detecting actual blood samples as well as superior resistance to interference from other substances (such as L-phenylalanine, urea, ascorbic acid, uric acid, NaCl, and KCl). These results establish the theoretical and experimental foundation for the application of rGO coating in the field of biosensors.


Assuntos
Técnicas Biossensoriais , Grafite , Glucose Oxidase , Ácido Úrico , Cloreto de Sódio , Técnicas Biossensoriais/métodos , Eletrodos , Glucose , Ácido Ascórbico , Ureia , Fenilalanina , Técnicas Eletroquímicas/métodos
10.
Int J Biometeorol ; 66(10): 1997-2008, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35902391

RESUMO

China is the largest fruit producer and consumer market in the world. Understanding the growing conditions responses to climate change is the key to predict future site suitability of main cultivation areas for certain deciduous fruit trees. In this study, we used dynamic and growing degree day models driven by downscaled daily temperatures from 22 global climate models to project the effects of climate change on growing conditions for deciduous fruit trees under two representative concentration pathway (RCP) 4.5 and RCP8.5 scenarios over 2 future time periods (represented by central years 2050s and 2085s) in northern China. The results showed a general increase of available winter chill for all sites under RCP4.5 scenario, and the most dramatic increase in chill accumulation could reach up to 36.8% in northeast regions for RCP8.5. However, the forecasted chill will decrease by 6.4% in southeast stations under RCP8.5 by 2085s. Additionally, the increase rate of growing season heat showed spatially consistency, and the most pronounced increase was found in the RCP8.5 by 2085s. For the southwest station, median heat accumulation increased by 20.8% in the 2050s and 37.1% in the 2085s under RCP8.5. Similar increasing range could be found in the northeast station; the median growing season heat increased by 19.8% and 38.8% in the 2050s and 2085s under RCP8.5, respectively. Moreover, the date of last spring frost was expected to advance and the frequency of frost occurrences was projected to decline in the study area compared to the past. Overall, the present study improves understanding regarding site-specific characteristics of climatic suitability for deciduous fruit tree cultivation in main producing regions of northern China. The results could provide growers and decision-makers with theoretical evidence to take adaptive measure to ensure fruit production in future.


Assuntos
Frutas , Árvores , China , Mudança Climática , Estações do Ano , Árvores/fisiologia
11.
FASEB J ; 34(9): 12324-12337, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32662527

RESUMO

Autophagy is an important mechanism for cellular homeostasis and survival during pathologic stress conditions in the kidney, such as ischemia-reperfusion (IR) injury. In this study, renal IR was induced in female C57BL/6 mice after melatonin administration. Renal function, histological damage, inflammatory infiltration, cytokine production, oxidative stress, antioxidant capacity, autophagy changing, apoptosis levels, and autophagy-associated intracellular signaling pathway were assessed to evaluate the impact of antecedent melatonin treatment on IR-induced renal injury. The administration of melatonin resulted in significantly preserved renal function, and the protective effect was associated with ameliorated oxidative stress, limited pro-inflammatory cytokine production, and neutrophil and macrophage infiltration. Moreover, autophagic flux was increased after melatonin administration while the apoptosis levels were decreased in the melatonin-pretreated mice. Using TAK-242 and CRX-527, we confirmed that MyD88-dependent TLR4 and MEK/ERK/mTORC1 signaling participated in melatonin-induced autophagy in IR mice. Collectively, our results provide novel evidence that antecedent melatonin treatment provides protection for the kidney against IR injury by enhancing autophagy, as regulated by the TLR4/MyD88/MEK/ERK/mTORC1 signaling pathway. Therefore, melatonin preconditioning offers a potential therapeutic approach to prevent renal IR injury related to various clinical conditions.


Assuntos
Autofagia/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/fisiologia , Rim/irrigação sanguínea , Alvo Mecanístico do Complexo 1 de Rapamicina/fisiologia , Quinases de Proteína Quinase Ativadas por Mitógeno/fisiologia , Fator 88 de Diferenciação Mieloide/fisiologia , Traumatismo por Reperfusão/prevenção & controle , Receptor 4 Toll-Like/fisiologia , Animais , Autofagia/fisiologia , Feminino , Inflamação/prevenção & controle , Melatonina/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Infiltração de Neutrófilos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
12.
Int J Mol Sci ; 22(16)2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34445508

RESUMO

This study investigated the effects of root-restriction cultivation on the root architecture, endogenous strigolactone (SL) content, and SL-related genes expression in grapevine (Vitis vinifera L.). In addition, we clarified the effects of synthetic SL analog GR24 application on grapevine roots to explore the role of SLs in their development. The results showed that the root architecture changed significantly under root-restriction cultivation. At 40 days after transplantation (DAT), the contents of two types of SLs in roots under root restriction were both significantly lower than that in roots of the control. SL content was significantly positively correlated with the expression levels of VvCCD8 and VvD27, indicating that they play vital roles in SLs synthesis. After GR24 treatment for 20 days, the root length was significantly shorter than in the control. A low concentration (0.1 µM) of GR24 significantly reduced the root diameter and increased the fine-root density, while a high concentration (10 µM) of GR24 significantly reduced the lateral root (LR) length and increased the LR density. Concomitantly, GR24 (0.1 µM) reduced endogenous SL content. After GR24 treatment for 5 days, the total content of two tested SLs was highly positively correlated with the expression levels of VvDAD2, whereas it was highly negatively correlated with VvSMAXL4 at 20 days after GR24 treatment. This study helps to clarify the internal mechanism of root-restriction cultivation affecting the changes in grapevine root architecture, as well as further explore the important role of SLs in the growth of grapevine roots in response to root-restriction treatment.


Assuntos
Compostos Heterocíclicos com 3 Anéis/farmacologia , Lactonas/farmacologia , Proteínas de Plantas/genética , Vitis/crescimento & desenvolvimento , Dioxigenases/genética , Relação Dose-Resposta a Droga , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Vitis/efeitos dos fármacos , Vitis/genética
13.
Sheng Li Xue Bao ; 73(3): 369-388, 2021 Jun 25.
Artigo em Zh | MEDLINE | ID: mdl-34230941

RESUMO

Spinal cord magnetic resonance imaging (MRI) is an advanced imaging technique (mainly in the cervical cord) and has been gradually used in basic scientific research such as human sensation and motor function, and clinical applications such as spinal cord injury, myelitis, and chronic pain, etc. The development of spinal cord MRI is still at the early stage compared with brain MRI and limited by the current MRI technology and data analysis methods. This review focuses on the methods and applications of spinal cord MRI technology in the basic research fields of cognitive neuroscience and clinical application. Firstly, we will introduce the imaging principle, methods, measurement standards, and applications of most commonly used multimodal spinal cord MRI techniques, including quantitative spinal cord MRI (such as structural, diffusion, spectroscopy, myelin water, magnetization transfer, and chemical exchange saturation transfer imaging, etc.) and spinal functional MRI (fMRI). Secondly, we will discuss the technical challenges and possible solutions of spinal cord MRI data processing from the three dimensions of denoising, data processing pipeline optimization, and repeatability and reliability. Finally, we will discuss the application status and development prospects of spinal cord MRI.


Assuntos
Traumatismos da Medula Espinal , Medula Espinal , Humanos , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Reprodutibilidade dos Testes , Medula Espinal/diagnóstico por imagem
14.
J Chem Phys ; 153(1): 014902, 2020 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-32640804

RESUMO

Suspensions of chemically powered self-propelled colloidal particles are examples of active matter systems with interesting properties. While simple spherical Janus particles are often studied, it is known that geometry is important and recent experiments have shown that chemically active torus-shaped colloids behave differently from spherical colloids. In this paper, coarse-grained microscopic simulations of the dynamics of self-diffusiophoretic torus colloids are carried out in bulk solution in order to study how torus geometric factors influence their active motion. The concentration and velocity fields are key ingredients in self-diffusiophoretic propulsion, and the forms that these fields take in the colloid vicinity are shown to be strong functions of torus geometric parameters such as the torus hole size and thickness of the torus tube. This work utilizes a method where self-diffusiophoretic torus colloids with various geometric and dynamical characteristics can be built and studied in fluid media that include chemical reactions and fluid flows. The model can be used to investigate the collective properties of these colloids and their dynamics in confined systems, topics that are of general importance for applications that use colloidal motors with complex geometries.

15.
Int J Mol Sci ; 21(3)2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-32019252

RESUMO

Floral bud dormancy release of fruit tree species is greatly influenced by climate change. The lack of chilling accumulation often results in the occurrence of abnormal flower and low yields of sweet cherries (Prunus avium L.) in warm regions. To investigate the regulation of dormancy in sweet cherries, six DAM genes with homology to peach DAM, designated PavDAM1-6, have been identified and characterized. Phylogenetic analysis indicate that these genes are similar to DAMs in peach, apple and pear. The expression patterns of the PavDAMs in the low-chill cultivar 'Royal Lee' were different from that in the high-chill cultivar 'Hongdeng'. 'Royal Lee' exhibits lower transcriptional level of PavDAM1 compared to 'Hongdeng', especially at the stage of chilling accumulation, and transcriptional levels of PavDAM4/5 were high in both cultivars during the endodormancy. Ectopic expression of PavDAM1 and PavDAM5 in Arabidopsis resulted in plants with abnormal flower and seed development, especially the PavDAM5. Higher transcriptional levels of SOC1 were observed in transgenic PavDAM1/5 lines, and ectopic expression of PavSOC1 had the similar floral phenotype. Further, protein interaction analysis demonstrated that PavDAM1/5 could interact with PavSOC1 in vivo and in vitro, which will help clarify the molecular mechanism of the flower development in sweet cherry or other fruit trees.


Assuntos
Temperatura Baixa , Flores/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Proteínas de Domínio MADS/metabolismo , Dormência de Plantas/genética , Proteínas de Plantas/metabolismo , Prunus avium/crescimento & desenvolvimento , Flores/genética , Flores/metabolismo , Proteínas de Domínio MADS/genética , Fenótipo , Filogenia , Proteínas de Plantas/genética , Prunus avium/genética , Prunus avium/metabolismo , Estações do Ano
16.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 37(1): 158-168, 2020 Feb 25.
Artigo em Zh | MEDLINE | ID: mdl-32096390

RESUMO

With the change of medical diagnosis and treatment mode, the quality of medical image directly affects the diagnosis and treatment of the disease for doctors. Therefore, realization of intelligent image quality control by computer will have a greater auxiliary effect on the radiographer's filming work. In this paper, the research methods and applications of image segmentation model and image classification model in the field of deep learning and traditional image processing algorithm applied to medical image quality evaluation are described. The results demonstrate that deep learning algorithm is more accurate and efficient than the traditional image processing algorithm in the effective training of medical image big data, which explains the broad application prospect of deep learning in the medical field. This paper developed a set of intelligent quality control system for auxiliary filming, and successfully applied it to the Radiology Department of West China Hospital and other city and county hospitals, which effectively verified the feasibility and stability of the quality control system.


Assuntos
Algoritmos , Inteligência Artificial , Processamento de Imagem Assistida por Computador , Controle de Qualidade , Radiografia Torácica , Humanos
17.
Biochem Biophys Res Commun ; 519(2): 227-233, 2019 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-31493865

RESUMO

BACKGROUND: Hepatic ischaemia-reperfusion (IR) injury is a common clinical challenge lacking effective therapy. The aim of this study was to investigate whether spermidine has protective effects against hepatic IR injury through autophagy. METHODS: Liver ischaemia reperfusion was induced in male C57BL/6 mice. Then, liver function, histopathology, cytokine production and immunofluorescence were evaluated to assess the impact of spermidine pre-treatment on IR-induced liver injury. Autophagosome formation was observed by transmission electron microscopy. Western blotting was used to explore the underlying mechanism and its relationship with autophagy, and TUNEL staining was conducted to determine the relationship between apoptosis and autophagy in the ischaemic liver. RESULTS: The results of the transaminase assay, histopathological examination, and pro-inflammatory cytokine production and immunofluorescence evaluations demonstrated that mice pre-treated with spermidine showed significantly preserved liver function. Further experiments demonstrated that mice administered spermidine before the induction of IR exhibited increased autophagy via the AMPK-mTOR-ULK1 pathway, and TUNEL staining revealed that spermidine attenuated IR-induced apoptosis in the liver. CONCLUSIONS: Our results provide the first line of evidence that spermidine provides protection against IR-induced injury in the liver by regulating autophagy through the AMPK-mTOR-ULK1 signalling pathway. These results suggest that spermidine may be beneficial for hepatic IR injury.


Assuntos
Autofagia/efeitos dos fármacos , Fígado/efeitos dos fármacos , Traumatismo por Reperfusão/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Espermidina/farmacologia , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/metabolismo , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Serina-Treonina Quinases TOR/metabolismo
18.
Hum Reprod ; 30(1): 61-70, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25398968

RESUMO

STUDY QUESTION: Does tumor necrosis factor-α (TNF-α) differentially regulate matrix metalloproteinase-2 (MMP-2) expression in leiomyomas compared with normal myometrium? SUMMARY ANSWER: TNF-α up-regulates MMP-2 expression and stimulates cell migration through the activation of extracellular signal-regulated kinase (ERK) signaling pathway in leiomyoma smooth muscle cells (SMCs), but not in normal myometrial SMCs. WHAT IS KNOWN ALREADY: Uterine leiomyoma, the benign smooth muscle cell tumor, is the single most common indication for hysterectomy. High expression of MMPs or TNF-α has been reported in uterine leiomyomas; however, the molecular mechanism underlying these observations remains unknown. STUDY DESIGN, SIZE, DURATION: Samples were obtained between 2009 and 2013 from 12 women of reproductive age at the proliferative phase of the menstrual cycle by hysterectomy. Leiomyomas and matched normal myometrium from each woman were analyzed in vitro. PARTICIPANTS/MATERIALS, SETTING, METHODS: Western blot, RT-qPCR and a wound-healing assay were used to investigate the effects of TNF-α on MMP-2 expression and intracellular signal transduction in cultured SMCs from leiomyomas and matched myometrium. MAIN RESULTS AND THE ROLE OF CHANCE: Western blot and RT-qPCR analyses using tissues from clinical patients showed that the levels of MMP-2 protein (P = 0.008) and mRNA (P = 0.009) were significantly higher in uterine leiomyomas compared with their matched myometrium. Treatment with TNF-α significantly up-regulated the protein (P = 0.039) and mRNA (P = 0.037) levels of MMP-2 in cultured leiomyoma SMCs but not in matched myometrial SMCs. The extracellular signal-regulated kinase (ERK) and nuclear factor-kappa B (NF-κB) pathways were activated by TNF-α in leiomyoma SMCs. Specific inhibitors of the ERK or NF-κB pathway (PD98059 or Bay11-7082) suppressed TNF-α-induced MMP-2 expression in leiomyoma SMCs. The wound-healing assay revealed that TNF-α promoted the migration of cultured leiomyoma SMCs (P = 0.036); however, PD98059 compromised the cell migration triggered by TNF-α. LIMITATIONS, REASONS FOR CAUTION: This study is descriptive and although we observed clear differential regulation of MMP-2 by TNF-α at mRNA and protein levels in leiomyoma, future studies are needed to identify why the difference in TNF-α response exists between human leiomyoma tissue and normal myometrium. Including some of the experiments such as transfection studies for TNF-α and MMP-2 promoter mapping could have added more insight as to why this difference exists. In addition, further studies in vivo are needed to verify the results obtained from primary cultured SMCs. WIDER IMPLICATIONS OF THE FINDINGS: Considering the positive effect of TNF-α on leiomyoma SMC migration, strategies targeting TNF-α, in parallel with the production of more specific inhibitors of MMPs, may provide alternative therapeutic approaches for the treatment of leiomyoma. STUDY FUNDING/COMPETING INTERESTS: This work was partially supported by grants from the Program for New Century Excellent Talents in University (NCET-12-0282), National Natural Science Foundation of China (81371620) and Tianjin Natural Science Foundation (12JCZDJC24900). The authors have no conflicts of interest to declare.


Assuntos
Leiomioma/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Miométrio/metabolismo , Fator de Necrose Tumoral alfa/fisiologia , Adulto , Movimento Celular , Células Cultivadas , Feminino , Fase Folicular/metabolismo , Humanos , Sistema de Sinalização das MAP Quinases , Pessoa de Meia-Idade , Miócitos de Músculo Liso/metabolismo , NF-kappa B/metabolismo , Transdução de Sinais , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo
19.
Soft Matter ; 10(38): 7511-8, 2014 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-25080889

RESUMO

The hydrodynamic behavior and propulsion mechanism of self-propelled micromotors are studied theoretically and experimentally. A hydrodynamic model to describe bubble growth and detachment is proposed to investigate the mechanism of a self-propelled conical tubular catalytic micromotor considering bubble geometric asymmetry and buoyancy force. The growth force caused by the growth of the bubble surface against the fluid is the driving force for micromotor motion. Also, the buoyancy force plays a primary role in bubble detachment. The effect of geometrical parameters on the micromotor velocity and drag force is presented. The bubble radius ratio is investigated for different micromotor radii to determine its hydrodynamic behavior during bubble ejection. The average micromotor velocity is found to be strongly dependent on the semi-cone angle, expelling frequency and bubble radius ratio. The semi-cone angle has a significant effect on the expelling frequency for conical tubular micromotors. The predicted results are compared to already existing experimental data for cylindrical micromotors (semi-cone angle δ = 0°) and conical micromotors. A good agreement is found between the theoretical calculation and experimental results. This model provides a profound explanation for the propulsion mechanism of a catalytic micromotor and can be used to optimize the micromotor design for its biomedical and environmental applications.

20.
Brain Res ; 1831: 148830, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38408557

RESUMO

OBJECTIVES: Previous studies have demonstrated that optic neuritis (ON) affects brain plasticity. However, whether ON affects the spinal cord remains unclear. We aimed to investigate the spinal cord changes in ON and their associations with disability. METHODS: A total of 101 ON patients, and 41 healthy controls (HC) were retrospectively recruited. High-resolution imaging was conducted using a Magnetization Prepared Rapid Acquisition Gradient-Echo (MP-RAGE) sequence for T1-weighted images and an echo planar imaging (EPI) sequence for Diffusion Tensor Imaging (DTI) data collection. Additionally, patients' disability and cognitive impairment were evaluated using the Expanded Disability Status Scale (EDSS) and the Paced Auditory Serial Addition Test (PASAT), respectively. The quantitative spinal MRI was employed to examine the cross-sectional area (CSA) and diffusion indicators, with a specific focus on calculating the average values across the C2-C7 cervical spinal cord segments. CSA, fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were compared between groups. Correlation analyses were performed between CSA, diffusion indicators, and clinical variables. RESULTS: No significant differences were found in CSA between ON patients and HCs. MD (p = 0.007) and RD (p = 0.018) were increased in ON patients compared with HCs, and AD was decreased in ON (p = 0.013). The AD values of the ON patients were significantly positively correlated with PASAT scores (r = 0.37, p < 0.001). CONCLUSIONS: This study provided imaging evidence for DTI abnormalities in patients with ON. Spinal cord DTI can improve our knowledge of the path physiology of ON, and clinical progression.


Assuntos
Imagem de Tensor de Difusão , Traumatismos da Medula Espinal , Humanos , Imagem de Tensor de Difusão/métodos , Estudos Retrospectivos , Medula Espinal/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos
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