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1.
Chirality ; 36(2): e23643, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38384156

RESUMO

In this study, lipase-catalyzed resolution of N-acetyl-DL-methionine methyl ester (N-Ac-DL-MetOMe) was evaluated. A lipase from Brucella thiophenivorans was prone to exhibit high activity and excellent enantioselectivity toward N-Ac-DL-MetOMe to produce the key chiral intermediate N-acetyl-L-methionine methyl ester (N-Ac-L-MetOMe). The results showed that the enzymatic reaction was carried out in 100 g/L racemic substrate for 2 h, the conversion reached 51.3%, the enantiomeric excess value N-Ac-L-MetOMe exceeded 99%, and the enantiomeric ratio value >200. Therefore, the lipase from B. thiophenivorans has potential prospects for the resolution of N-Ac-DL-MetOMe to produce the important intermediate N-Ac-L-MetOMe.


Assuntos
Brucella , Lipase , Metionina/análogos & derivados , Ésteres , Estereoisomerismo
2.
Transfus Med ; 34(2): 136-141, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38258949

RESUMO

BACKGROUND: Hepatitis B virus (HBV) reactivity in individual immunologic and nucleic acid tests (NAT) tests does not represent the true infectious status of the blood donor. This study discusses the use of confirmatory tests to determine when deferral of blood donors is appropriate. METHODS: HBsAg or HBV NAT reactive samples were confirmed via a neutralisation test. All the HBsAg reactive but neutralisation test negative samples were subjected to further anti-HBc testing. The receiver operating characteristic curve was used to obtain the best threshold value using signal-to-cut-off ratios of two HBsAg enzyme-linked immunosorbent assay reagents. RESULTS: Of the 780 HBV reactive samples collected, there were 467 HBsAg reactive but HBV DNA negative samples, of which 65 (13.92%) and 402 (86.08%) were neutralisation test positive and negative, respectively. Of the 402, 91 samples (30% of tested samples) were anti-HBc reactive. HBV DNA positive specimens negative by virus neutralisation were >80% HBcAg positive. A screening strategy was proposed for Chinese blood collection agencies. CONCLUSION: These findings suggest that adopting a screening algorithm for deferring HBV reactive blood donors based on HBsAg and NAT testing followed with HBsAg S/CO consideration and HBcAg testing can be both safe and feasible in China.


Assuntos
Antígenos do Núcleo do Vírus da Hepatite B , Hepatite B , Humanos , Antígenos de Superfície da Hepatite B , Doadores de Sangue , DNA Viral , Hepatite B/prevenção & controle , Vírus da Hepatite B/genética , Anticorpos Anti-Hepatite B
3.
J Formos Med Assoc ; 122(7): 603-611, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36336606

RESUMO

OBJECTIVE: The aim of this study was to determine whether cognitive function is associated with future falls in older patients with diabetes mellitus (DM) compared with those without DM. Cognitive function was divided into several domains to further analyze. METHODS: A total of 678 individuals met the inclusion criteria and comprised the final study population. The mean age was 74.35 ± 5.35 years, and 58.9% of the participants were female (n = 400). At the baseline, cognitive function was measured by the Mini Mental State Examination (MMSE), and DM diagnoses were determined by medical records. The self-reported any falls data were obtained via face-to-face questioning at the 1-year follow-up. RESULTS: At baseline, 15.6% of participants (n = 106) were diagnosed with DM. According to whether they had any falls during 1-year follow-up, there was a significant difference between the two group in fasting plasma glucose (p = 0.012) and DM (p = 0.036) at baseline. Among the older adults with DM, those who had experienced any falls had poorer cognitive function (p = 0.014). After adjusting for various covariates, we found that MMSE (95% CI 0.790-0.991, p = 0.034), orientation to place (95% CI 0.307-0.911, p = 0.022) and registration (95% CI 0.162-0.768, p = 0.009) were significantly associated with falls in the follow-up. CONCLUSION: Our study found that in patients with DM, cognitive function is related to future falls. Not only overall cognitive function, but also orientation to place and registration were all associated with future falls in older adults with DM. When completing the fall risk assessment of elderly patients with DM, clinicians should give more attention to the testing of cognitive function.


Assuntos
Diabetes Mellitus , Vida Independente , Idoso , Feminino , Humanos , Masculino , Acidentes por Quedas , Cognição , Diabetes Mellitus/epidemiologia , População do Leste Asiático
4.
BMC Neurol ; 22(1): 166, 2022 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-35501719

RESUMO

Lysophosphatidic acid (LPA) is a common glycerol phospholipid and an important extracellular signaling molecule. LPA binds to its receptors and mediates a variety of biological effects, including the pathophysiological process underlying ischemic brain damage and traumatic brain injury. However, the molecular mechanisms mediating the pathological role of LPA are not clear. Here, we found that LPA activates cyclin-dependent kinase 5 (CDK5). CDK5 phosphorylates tau, which leads to neuronal cell death. Inhibition of LPA production or blocking its receptors reduced the abnormal activation of CDK5 and phosphorylation of tau, thus reversing the death of neurons. Our data indicate that the LPA-CDK5-Tau pathway plays an important role in the pathophysiological process after ischemic stroke. Inhibiting the LPA pathway may be a potential therapeutic target for treating ischemic brain injury.


Assuntos
Quinase 5 Dependente de Ciclina , Proteínas tau , Quinase 5 Dependente de Ciclina/metabolismo , Quinase 5 Dependente de Ciclina/farmacologia , Humanos , Isquemia , Lisofosfolipídeos , Neurônios , Reperfusão , Proteínas tau/metabolismo
5.
Anal Bioanal Chem ; 414(12): 3625-3630, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35257216

RESUMO

Graphene oxide (GO) is an excellent chemical tunable optical platform for imaging and sensing. The photoluminescence (PL) quantum yield of GO is relatively low, which limited the application of the intrinsic and tunable fluorescence from GO. Here, we report the first case of metal-enhanced fluorescence (MEF) of GO. A significant enhancement (~10-fold) in fluorescence intensity is observed from GO on the Ag substrate as compared to that on the glass. FL, Raman, and SEM images are used to investigate the MEF behavior and are coincident with each other. The influence of the metal particle size of Ag substrate is investigated. The fluorescence is also found to be responsive when adding different metal ions into GO solution. GO contacting directly with metal substrate exhibits strong MEF without quenching, which makes it possible to use GO sheets for three-dimension optical imaging and sensing.


Assuntos
Grafite , Fluorescência , Metais , Tamanho da Partícula
6.
Global Health ; 18(1): 15, 2022 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-35151336

RESUMO

BACKGROUND: The absence of pharmaceutical interventions made it particularly difficult to mitigate the first outbreak of coronavirus disease 2019 (COVID-19). The current study investigated how economic freedom and equality influenced the pandemic control process. METHODS: In Study 1, we assessed the effect of economic freedom and equality on COVID-19 pandemic control from nations worldwide. We collected the cumulative number of confirmed cases over time to perform logistic curve fitting and obtain the speed at which the first wave of the pandemic was controlled, and partial correlation analysis and representational similarity analysis (RSA) were performed to assess the similarity between economic freedom and the speed of pandemic control. In Study 2, an evolutionary game model in which economic freedom affects the speed of pandemic control through optimization of the allocation of available resources was developed. In Study 3, we used experimental manipulation to elucidate the psychological mechanism relating economic freedom and resource allocation. RESULTS: The economic freedom of nation could be used to positively predict the speed of pandemic control and the related similarity pattern. Equality was found to moderate the correlation and representational similarity between economic freedom and the speed of pandemic control. The evolutionary game model revealed a mechanism whereby economic freedom influences the speed of pandemic control through high resource availability. Furthermore, cooperation was found to be a possible psychological mechanism explaining how economic freedom increases resource availability. CONCLUSIONS: Economic freedom has a positive effect on the control of the COVID-19 pandemic only among highly egalitarian nations. New interventions are needed to help countries heighten economic freedom and equality as they continue to battle COVID-19 and other collective threats.


Assuntos
COVID-19 , Pandemias , Liberdade , Humanos , Pandemias/prevenção & controle , SARS-CoV-2
7.
Plant Mol Biol ; 99(3): 283-298, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30623274

RESUMO

KEY MESSAGE: Methane-triggered lateral root formation is not only a universal event, but also dependent on L-cysteine desulfhydrase-dependent hydrogen sulfide signaling. Whether or how methane (CH4) triggers lateral root (LR) formation has not been elucidated. In this report, CH4 induction of lateral rooting and the role of hydrogen sulfide (H2S) were dissected in tomato and Arabidopsis by using physiological, anatomical, molecular, and genetic approaches. First, we discovered that CH4 induction of lateral rooting is a universal event. Exogenously applied CH4 not only triggered tomato lateral rooting, but also increased activities of L-cysteine desulfhydrase (DES; a major synthetic enzyme of H2S) and induced endogenous H2S production, and contrasting responses were observed in the presence of hypotaurine (HT; a scavenger of H2S) or DL-propargylglycine (PAG; an inhibitor of DES) alone. CH4-triggered lateral rooting were sensitive to the inhibition of endogenous H2S with HT or PAG. The changes in the transcripts of representative cell cycle regulatory genes, miRNA and its target genes were matched with above phenotypes. In the presence of CH4, Arabidopsis mutant Atdes1 exhibited defects in lateral rooting, compared with the wild-type. Molecular evidence showed that the transcriptional profiles of representative target genes modulated by CH4 in wild-type plants were impaired in Atdes1 mutant. Overall, our data demonstrate the main branch of the DES-dependent H2S signaling cascade in CH4-triggered LR formation.


Assuntos
Cistationina gama-Liase/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Sulfeto de Hidrogênio/metabolismo , Metano/farmacologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Cistationina gama-Liase/genética , Genes de Plantas/genética , Solanum lycopersicum/genética , Solanum lycopersicum/metabolismo , MicroRNAs/genética , Mutação , Proteínas de Plantas/genética , Raízes de Plantas/citologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Transcriptoma
8.
Transfusion ; 59(7): 2361-2367, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30985961

RESUMO

BACKGROUND: China has not yet incorporated routine human T-lymphotropic virus (HTLV)-1/2 blood donor screening, even though HTLV has been reported in the southeastern coastal region. This study was conducted to investigate the prevalence of HTLV in five major regions across of China. METHODS: From January 2016 to December 2017, blood samples were collected in 20 blood centers located in different regions of China. These samples were screened for HTLV-1/2 antibodies using enzyme-linked immunosorbent assay (ELISA). If the test samples were reactive, the samples were confirmed with a western blot (WB) assay. If the results of WB were indeterminate, the donor was interviewed after a minimum lapse of 8 weeks. All follow-up samples from donors were tested for anti-HTLV-1/2 with ELISA and WB. RESULTS: There were 875,453 donor samples tested for anti-HTLV-1/2 by ELISA. In all, 365 samples tested negative, 22 samples tested positive by WB, and 14 samples with HTLV status undetermined due to being lost to follow-up. The prevalences were 11.09, 5.96, 3.16, 2.88 and 0.98 per 100,000 in Xiamen, Changsha, Beijing, Shenzhen, and Nanjing blood center, respectively. The prevalences were 0 per 100,000 for all 15 other blood centers. There was significant differences in the prevalence of HTLV in different regions of China (p = 0.0011). CONCLUSION: In China, HTLV-1 confirmed positive donors are mainly from southeastern coastal areas. It may be necessary to conduct HTLV screening in these areas to reduce the risk of transfusion-transmitted HTLV.


Assuntos
Doadores de Sangue , Seleção do Doador , Anticorpos Anti-HTLV-I/sangue , Infecções por HTLV-I , Anticorpos Anti-HTLV-II/sangue , Infecções por HTLV-II , Vírus Linfotrópico T Tipo 1 Humano/metabolismo , Vírus Linfotrópico T Tipo 2 Humano/metabolismo , Adulto , China/epidemiologia , Feminino , Infecções por HTLV-I/sangue , Infecções por HTLV-I/epidemiologia , Infecções por HTLV-II/sangue , Infecções por HTLV-II/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência
9.
Plant Cell Rep ; 38(3): 377-389, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30617541

RESUMO

KEY MESSAGE: Pharmacological and molecular evidence reveals a novel role of methane (CH4) gas in root organogenesis, the induction of lateral root (LR) formation, and this response might require hydrogen peroxide (H2O2) synthesis. Although plants can produce CH4 and release this to atmosphere, the beneficial role(s) of CH4 are not fully elucidated. In this study, the fumigation with CH4 not only increased NADPH oxidase activity and H2O2 production, but also induced tomato lateral root primordial formation and thereafter LR development. However, exogenously applied argon and nitrogen failed to influence LR formation. Above responses triggered by CH4 were sensitive to the removal of endogenous H2O2 with dimethylthiourea (DMTU; a membrane-permeable scavenger of H2O2), suggesting the hypothesis that CH4's effect on LR formation could be mediated by endogenous H2O2. Diphenylene iodonium (DPI) inhibition of the H2O2 generating enzyme NADPH oxidase attenuated H2O2 synthesis and impaired LR formation in response to CH4, confirming the requirement of NADPH oxidase-dependent H2O2. Meanwhile, the alterations of endogenous H2O2 concentrations failed to influence CH4 production in tomato seedlings. Molecular evidence revealed that CH4-induced SlCDKA1, SlCYCA2;1, and SlCYCA3;1 transcripts, and -decreased SlKRP2 mRNA were impaired by DMTU or DPI. Contrasting changes in LR formation-related miR390a and miR160 transcripts and their target genes, including SlARF4 and SlARF16, were observed. Together, our pharmacological and molecular evidence suggested the requirement of H2O2 synthesis in CH4-triggered tomato LR formation, partially via the regulation of cell cycle regulatory genes, miRNA-, and tasiRNA-modulated gene expression.


Assuntos
Peróxido de Hidrogênio/metabolismo , Metano/metabolismo , Raízes de Plantas/metabolismo , Solanum lycopersicum/metabolismo , Regulação da Expressão Gênica de Plantas/fisiologia , NADPH Oxidases/metabolismo , Proteínas de Plantas , Plântula/metabolismo , Tioureia/análogos & derivados , Tioureia/metabolismo
10.
Ann Bot ; 121(6): 1127-1136, 2018 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-29325001

RESUMO

Background and Aims: Although several studies have confirmed the beneficial roles of exogenous melatonin in lateral root (LR) formation, the molecular mechanism is still elusive. Here, the role of hydrogen peroxide (H2O2) in the induction of LR formation triggered by melatonin was investigated. Methods: Alfalfa (Medicago sativa 'Biaogan') and transgenic Arabidopsis seedlings were treated with or without melatonin, diphenyleneiodonium (DPI, NADPH oxidase inhibitor), N,N'-dimethylthiourea (DMTU, H2O2 scavenger), alone or combined. Then, H2O2 content was determined with 2',7'-dichlorofluorescein diacetate (H2DCFDA)-dependent fluorescence and spectrophotography. Transcript levels of cell cycle regulatory genes were analysed by real-time reverse transcription-PCR. Key Results: Application of exogenous melatonin not only increased endogenous H2O2 content but also induced LR formation in alfalfa seedlings. Consistently, melatonin-induced LR primordia exhibited an accelerated response. These inducible responses were significantly blocked when DPI or DMTU was applied. Compared with the wild-type, transgenic Arabidopsis plants overexpressing alfalfa MsSNAT (a melatonin synthesis gene) increased H2O2 accumulation and thereafter LR formation, both of which were blocked by DPI or DMTU. Similarly, melatonin-modulated expression of marker genes responsible for LR formation, including MsCDKB1;1, MsCDKB2;1, AtCDKB1;1 and AtCDKB2;1, was obviously impaired by the removal of H2O2 in both alfalfa and transgenic Arabidopsis plants. Conclusions: Pharmacological and genetic evidence revealed that endogenous melatonin-triggered LR formation was H2O2-dependent.


Assuntos
Peróxido de Hidrogênio/metabolismo , Melatonina/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Medicago sativa/crescimento & desenvolvimento , Medicago sativa/metabolismo , Melatonina/farmacologia , Melatonina/fisiologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase em Tempo Real
11.
BMC Plant Biol ; 17(1): 162, 2017 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-29029623

RESUMO

BACKGROUND: Both hydrogen sulfide (H2S) and hydrogen peroxide (H2O2) are separately regarded as a highly reactive molecule involved in root morphogenesis. In this report, corresponding causal link governing lateral root formation was investigated. METHODS: By using pharmacological, anatomic, and molecular approaches, evidence presented here revealed the molecular mechanism underlying tomato lateral root development triggered by H2S. RESULTS: A H2S donor sodium hydrosulfide (NaHS) triggered the accumulation of H2O2, the up-regulation of RBOH1 transcript, and thereafter tomato lateral root formation. Above responses were sensitive to the H2O2 scavenger (dimethylthiourea; DMTU) and the inhibitor of NADPH oxidase (diphenylene idonium; DPI), showing that the accumulations of H2O2 and increased RBOH1 transcript were respectively prevented. Lateral root primordial and lateral root formation were also impaired. Further molecular evidence revealed that H2S-modulated gene expression of cell cycle regulatory genes, including up-regulation of SlCYCA2;1, SlCYCA3;1, and SlCDKA1, and the down-regulation of SlKRP2, were prevented by the co-treatment with DMTU or DPI. Above mentioned inducing phenotypes were consistent with the changes of lateral root formation-related microRNA transcripts: up-regulation of miR390a and miR160, and with the opposite tendencies of their target genes (encoding auxin response factors). Contrasting tendencies were observed when DMTU or DPI was added together. The occurrence of H2S-mediated S-sulfhydration during above responses was preliminarily discovered. CONCLUSIONS: Overall, these results suggested an important role of RBOH1-mediated H2O2 in H2S-elicited tomato lateral root development, and corresponding H2S-target proteins regulated at transcriptional and post-translational levels.


Assuntos
Peróxido de Hidrogênio , Sulfeto de Hidrogênio , Raízes de Plantas/crescimento & desenvolvimento , Plântula/crescimento & desenvolvimento , Solanum lycopersicum/crescimento & desenvolvimento , Proteínas de Plantas/metabolismo
12.
Plant Cell Rep ; 34(3): 381-93, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25433859

RESUMO

KEY MESSAGE: ß-Cyclodextrin-hemin complex-induced tomato lateral root formation was associated with nitric oxide and heme oxygenase 1 by modulating cell cycle regulatory genes. ß-Cyclodextrin-hemin complex (ß-CDH), a complex by combining ß-cyclodextrin (ß-CD) with hemin, a heme oxygenase 1 (HO1) inducer, was a trigger of cucumber adventitious root formation by enhancing HO1 gene expression. In this report, our results identified the previously unknown function of ß-CDH in plants: the inducer of tomato lateral root (LR) formation. ß-CDH-triggered LR formation is hemin-specific, since ß-CD failed to induce LR development. Because nitric oxide (NO) is involved in LR formation, the correlation of ß-CDH with NO and HO1 was investigated. Our analysis suggested that ß-CDH induced an increase in endogenous NO production, followed by up-regulation of tomato HO1 gene and LR formation, all of which were mimicked by hemin and two NO-releasing compounds (SNP and GSNO). The induction of HO1 gene expression and LR formation triggered by ß-CDH or hemin were significantly blocked by an inhibitor of HO1. Further results revealed that both ß-CDH- and SNP-stimulated HO1 gene expression and thereafter LR formation were sensitive to the removal of NO with a potent NO scavenger, and the responses of SNP were significantly blocked by an inhibitor of HO1. Molecular evidence illustrated that representative cell cycle regulatory genes, including SlCDKA1, SlCYCA3;1, SlCYCA2;1, and SlCYCD3;1, were significantly up-regulated by ß-CDH and SNP, but obviously blocked when seedlings were co-treated with the scavenger of NO or the inhibitor of HO1. In summary, our physiological and molecular evidence demonstrated that both NO and HO1 were involved in the ß-CDH-induced LR formation with, at least partially, HO1 acting downstream of NO signaling.


Assuntos
Heme Oxigenase-1/metabolismo , Hemina/farmacologia , Óxido Nítrico/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Solanum lycopersicum/efeitos dos fármacos , beta-Ciclodextrinas/farmacologia , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Heme Oxigenase-1/antagonistas & inibidores , Heme Oxigenase-1/genética , Ácidos Indolacéticos/metabolismo , Solanum lycopersicum/genética , Solanum lycopersicum/crescimento & desenvolvimento , Solanum lycopersicum/metabolismo , Nitroprussiato/farmacologia , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Protoporfirinas/farmacologia , S-Nitrosoglutationa/farmacologia , Plântula/efeitos dos fármacos
13.
Plant Cell Rep ; 33(6): 969-78, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24556961

RESUMO

By using pharmacological and molecular approaches, we discovered the involvement of HO-1 in NaHS-induced lateral root formation in tomato seedlings. Heme oxygenase-1 (HO-1) and hydrogen sulfide (H2S) regulate various responses to abiotic stress and root development, but their involvement in the simultaneous regulation of plant lateral root (LR) formation is poorly understood. In this report, we observed that the exogenously applied H2S donor sodium hydrosulfide (NaHS) and the HO-1 inducer hemin induce LR formation in tomato seedlings by triggering intracellular signaling events involving the induction of tomato HO-1 (SlHO-1), and the modulation of cell cycle regulatory genes, including the up-regulation of SlCDKA;1 and SlCYCA2;1, and simultaneous down-regulation of SlKRP2. The response of NaHS in the induction of LR formation was impaired by the potent inhibition of HO-1, which was further blocked when 50 % saturation of carbon monoxide (CO) aqueous solution, one of the catalytic by-products of HO-1, was added. Further molecular evidence revealed that the NaHS-modulated gene expression of cell cycle regulatory genes was sensitive to the inhibition of HO-1 and reversed by cotreatment with CO. The impairment of LR density and length as well as lateral root primordia number, the decreased tomato HO-1 gene expression and HO activity caused by an H2S scavenger hypotaurine were partially rescued by the addition of NaHS, hemin and CO (in particular). Together, these results revealed that at least in our experimental conditions, HO-1 might be involved in NaHS-induced tomato LR formation. Additionally, the use of NaHS and hemin compounds in crop root organogenesis should be explored.


Assuntos
Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Heme Oxigenase-1/genética , Solanum lycopersicum/enzimologia , Sulfetos/farmacologia , Monóxido de Carbono/farmacologia , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Heme Oxigenase-1/metabolismo , Hemina/farmacologia , Sulfeto de Hidrogênio/farmacologia , Solanum lycopersicum/efeitos dos fármacos , Solanum lycopersicum/genética , Solanum lycopersicum/crescimento & desenvolvimento , Modelos Biológicos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/enzimologia , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Plântula/efeitos dos fármacos , Plântula/enzimologia , Plântula/genética , Plântula/crescimento & desenvolvimento
14.
IEEE Trans Med Imaging ; 43(4): 1640-1651, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38133966

RESUMO

Unsupervised domain adaptation(UDA) aims to mitigate the performance drop of models tested on the target domain, due to the domain shift from the target to sources. Most UDA segmentation methods focus on the scenario of solely single source domain. However, in practical situations data with gold standard could be available from multiple sources (domains), and the multi-source training data could provide more information for knowledge transfer. How to utilize them to achieve better domain adaptation yet remains to be further explored. This work investigates multi-source UDA and proposes a new framework for medical image segmentation. Firstly, we employ a multi-level adversarial learning scheme to adapt features at different levels between each of the source domains and the target, to improve the segmentation performance. Then, we propose a multi-model consistency loss to transfer the learned multi-source knowledge to the target domain simultaneously. Finally, we validated the proposed framework on two applications, i.e., multi-modality cardiac segmentation and cross-modality liver segmentation. The results showed our method delivered promising performance and compared favorably to state-of-the-art approaches.


Assuntos
Coração , Fígado , Coração/diagnóstico por imagem , Fígado/diagnóstico por imagem , Processamento de Imagem Assistida por Computador
15.
Parasitol Res ; 112(5): 1967-72, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23471780

RESUMO

During a survey lasting from 1990 to 2008, we captured 4,113 Asian house rats, Rattus tanezumi Temminck 1844 (Rodentia: Muridae) from 28 counties of Yunnan Province in southwestern China. From these rats, a total of 19,304 gamasid mites (Acari: Mesostigmata) were collected and identified as comprising 50 different species. The species diversity of gamasid mites from this single rat species is higher than that reported previously from multiple hosts within a given geographical region. Of the 50 mite species, 31 species belonged to ectoparasites and 19 species belonged to free-living mites. The species diversity of the mites from rats trapped outdoors was much higher than from rats trapped indoors. The parameter K from the negative binomial distribution was used to measure the spatial distribution patterns of the dominant mite species and revealed that all the mites had an aggregated distribution among the rat hosts. Most mite species showed a predominantly female-biased population structure with many more females than males.


Assuntos
Ácaros e Carrapatos/classificação , Interações Hospedeiro-Parasita , Infestações por Ácaros/parasitologia , Ratos/parasitologia , Doenças dos Roedores/parasitologia , Animais , China , Ecossistema , Feminino , Masculino , Densidade Demográfica , Distribuição por Sexo , Especificidade da Espécie
16.
J Alzheimers Dis ; 94(s1): S355-S366, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36683509

RESUMO

Meningeal lymphatic vessels (mLVs), the functional lymphatic system present in the meninges, are the key drainage route responsible for the clearance of molecules, immune cells, and cellular debris from the cerebrospinal fluid and interstitial fluid into deep cervical lymph nodes. Aging and ApoE4, the two most important risk factors for Alzheimer's disease (AD), induce mLV dysfunction, decrease cerebrospinal fluid influx and outflux, and exacerbate amyloid pathology and cognitive dysfunction. Dysfunction of mLVs results in the deposition of metabolic products, accelerates neuroinflammation, and promotes the release of pro-inflammatory cytokines in the brain. Thus, mLVs represent a novel therapeutic target for treating neurodegenerative and neuroinflammatory diseases. This review aims to summarize the structure and function of mLVs and to discuss the potential effect of aging and ApoE4 on mLV dysfunction, as well as their roles in the pathogenesis of AD.


Assuntos
Doença de Alzheimer , Sistema Glinfático , Vasos Linfáticos , Humanos , Doença de Alzheimer/patologia , Sistema Glinfático/metabolismo , Apolipoproteína E4/metabolismo , Sistema Linfático/metabolismo , Sistema Linfático/patologia
17.
Comput Biol Med ; 152: 106308, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36462371

RESUMO

PURPOSE: The identification of early-stage Parkinson's disease (PD) is important for the effective management of patients, affecting their treatment and prognosis. Recently, structural brain networks (SBNs) have been used to diagnose PD. However, how to mine abnormal patterns from high-dimensional SBNs has been a challenge due to the complex topology of the brain. Meanwhile, the existing prediction mechanisms of deep learning models are often complicated, and it is difficult to extract effective interpretations. In addition, most works only focus on the classification of imaging and ignore clinical scores in practical applications, which limits the ability of the model. Inspired by the regional modularity of SBNs, we adopted graph learning from the perspective of node clustering to construct an interpretable framework for PD classification. METHODS: In this study, a multi-task graph structure learning framework based on node clustering (MNC-Net) is proposed for the early diagnosis of PD. Specifically, we modeled complex SBNs into modular graphs that facilitated the representation learning of abnormal patterns. Traditional graph neural networks are optimized through graph structure learning based on node clustering, which identifies potentially abnormal brain regions and reduces the impact of irrelevant noise. Furthermore, we employed a regression task to link clinical scores to disease classification, and incorporated latent domain information into model training through multi-task learning. RESULTS: We validated the proposed approach on the Parkinsons Progression Markers Initiative dataset. Experimental results showed that our MNC-Net effectively separated the early-stage PD from healthy controls(HC) with an accuracy of 95.5%. The t-SNE figures have showed that our graph structure learning method can capture more efficient and discriminatory features. Furthermore, node clustering parameters were used as important weights to extract salient task-related brain regions(ROIs). These ROIs are involved in the development of mood disorders, tremors, imbalances and other symptoms, highlighting the importance of memory, language and mild motor function in early PD. In addition, statistical results from clinical scores confirmed that our model could capture abnormal connectivity that was significantly different between PD and HC. These results are consistent with previous studies, demonstrating the interpretability of our methods.


Assuntos
Doença de Parkinson , Humanos , Doença de Parkinson/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Encéfalo/diagnóstico por imagem , Redes Neurais de Computação , Diagnóstico Precoce
18.
Med Image Anal ; 88: 102869, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37384950

RESUMO

Multi-modality cardiac imaging plays a key role in the management of patients with cardiovascular diseases. It allows a combination of complementary anatomical, morphological and functional information, increases diagnosis accuracy, and improves the efficacy of cardiovascular interventions and clinical outcomes. Fully-automated processing and quantitative analysis of multi-modality cardiac images could have a direct impact on clinical research and evidence-based patient management. However, these require overcoming significant challenges including inter-modality misalignment and finding optimal methods to integrate information from different modalities. This paper aims to provide a comprehensive review of multi-modality imaging in cardiology, the computing methods, the validation strategies, the related clinical workflows and future perspectives. For the computing methodologies, we have a favored focus on the three tasks, i.e., registration, fusion and segmentation, which generally involve multi-modality imaging data, either combining information from different modalities or transferring information across modalities. The review highlights that multi-modality cardiac imaging data has the potential of wide applicability in the clinic, such as trans-aortic valve implantation guidance, myocardial viability assessment, and catheter ablation therapy and its patient selection. Nevertheless, many challenges remain unsolved, such as missing modality, modality selection, combination of imaging and non-imaging data, and uniform analysis and representation of different modalities. There is also work to do in defining how the well-developed techniques fit in clinical workflows and how much additional and relevant information they introduce. These problems are likely to continue to be an active field of research and the questions to be answered in the future.


Assuntos
Doenças Cardiovasculares , Imageamento Tridimensional , Humanos , Imageamento Tridimensional/métodos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos
19.
IEEE Trans Med Imaging ; 42(12): 3474-3486, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37347625

RESUMO

Myocardial pathology segmentation (MyoPS) is critical for the risk stratification and treatment planning of myocardial infarction (MI). Multi-sequence cardiac magnetic resonance (MS-CMR) images can provide valuable information. For instance, balanced steady-state free precession cine sequences present clear anatomical boundaries, while late gadolinium enhancement and T2-weighted CMR sequences visualize myocardial scar and edema of MI, respectively. Existing methods usually fuse anatomical and pathological information from different CMR sequences for MyoPS, but assume that these images have been spatially aligned. However, MS-CMR images are usually unaligned due to the respiratory motions in clinical practices, which poses additional challenges for MyoPS. This work presents an automatic MyoPS framework for unaligned MS-CMR images. Specifically, we design a combined computing model for simultaneous image registration and information fusion, which aggregates multi-sequence features into a common space to extract anatomical structures (i.e., myocardium). Consequently, we can highlight the informative regions in the common space via the extracted myocardium to improve MyoPS performance, considering the spatial relationship between myocardial pathologies and myocardium. Experiments on a private MS-CMR dataset and a public dataset from the MYOPS2020 challenge show that our framework could achieve promising performance for fully automatic MyoPS.


Assuntos
Meios de Contraste , Infarto do Miocárdio , Humanos , Imagem Cinética por Ressonância Magnética/métodos , Gadolínio , Miocárdio/patologia , Infarto do Miocárdio/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Valor Preditivo dos Testes
20.
Nat Commun ; 14(1): 261, 2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36650148

RESUMO

Separation of actinides from lanthanides is of great importance for the safe management of nuclear waste and sustainable development of nuclear energy, but it represents a huge challenge due to the chemical complexity of these f-elements. Herein, we report an efficient separation strategy based on ion sieving in graphene oxide membrane. In the presence of a strong oxidizing reagent, the actinides (U, Np, Pu, Am) in a nitric acid solution exist in the high valent and linear dioxo form of actinyl ions while the lanthanides (Ce, Nd, Eu, Gd, etc.) remain as trivalent/tetravalent spheric ions. A task-specific graphene oxide membrane with an interlayer nanochannel spacing between the sizes of hydrated actinyl ions and lanthanides ions is tailored and used as an ionic cut-off filter, which blocks the larger and linear actinyl ions but allows the smaller and spheric lanthanides ions to penetrate through, affording lanthanides/actinides separation factors up to ~400. This work realizes the group separation of actinides from lanthanides under highly acidic conditions by a simple ion sieving strategy and highlights the great potential of utilizing graphene oxide membrane for nuclear waste treatment.

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