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1.
Ecotoxicol Environ Saf ; 273: 116099, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38422788

RESUMO

Sulfamethoxazole (SMZ) is a frequently detected antibiotic in the environment, and there is a growing concern about its potential toxic effects on aquatic organisms. sea cucumber (Apostichopus japonicas) is a benthic invertebrate whose gut acts as a primary immune defense and serves critical protective barrier. In this study, growth performance, histology, gut microbiota, and metabolomics analyses were performed to investigate the toxic response in the intestine of sea cucumber effects caused by SMZ stress for 56 d by evaluating with different concentrations of SMZ (0, 1.2×10-3, and 1.2 mg/L). The weight gain rate of sea cucumbers under SMZ stress showed significant decrease, indicating that the growth of sea cucumbers was hindered. Analysis of the intestinal morphological features indicated that SMZ stimulation resulted in atrophy of the sea cucumber gut. In the 1.2×10-3 mg/L concentration, the thickness of muscle and mucosal layers was reduced by 12.40% and 21.39%, while in the 1.2 mg/L concentration, the reductions were 35.08% and 26.98%. The abundance and diversity of sea cucumber intestinal bacteria decreased significantly (P < 0.05) under the influence of SMZ. Notably, the intestinal bacteria of sea cucumber became homogenized with the increase in SMZ concentration, and the relative abundance of Ralstonia reached 81.64% under the stress of 1.2 mg/L concentration. The SMZ stress significantly impacted host metabolism and disrupted balance, particularly in L-threonine, L-tyrosine, neuronic acid, piperine, and docosapentaenoic acid. SMZ leads to dysregulation of metabolites, resulting in growth inhibition and potential inflammatory responses that could adversely affect the normal activities of aquatic organisms. Further metabolic pathway enrichment analyses demonstrated that impaired biosynthesis of unsaturated fatty acids and aminoacyl-tRNA biosynthesis metabolic pathway were major reasons for SMZ stress-induced intestinal bacteria dysbiosis. This research aims to provide some theoretical evidence for the ecological hazard assessment of antibiotics in water.


Assuntos
Pepinos-do-Mar , Stichopus , Animais , Sulfametoxazol/toxicidade , Sulfametoxazol/metabolismo , Metabolômica , Bactérias/genética
2.
Sensors (Basel) ; 23(20)2023 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-37896601

RESUMO

Anomaly detection tasks involving time-series signal processing have been important research topics for decades. In many real-world anomaly detection applications, no specific distributions fit the data, and the characteristics of anomalies are different. Under these circumstances, the detection algorithm requires excellent learning ability of the data features. Transformers, which apply the self-attention mechanism, have shown outstanding performances in modelling long-range dependencies. Although Transformer based models have good prediction performance, they may be influenced by noise and ignore some unusual details, which are significant for anomaly detection. In this paper, a novel temporal context fusion framework: Temporal Context Fusion Transformer (TCF-Trans), is proposed for anomaly detection tasks with applications to time series. The original feature transmitting structure in the decoder of Informer is replaced with the proposed feature fusion decoder to fully utilise the features extracted from shallow and deep decoder layers. This strategy prevents the decoder from missing unusual anomaly details while maintaining robustness from noises inside the data. Besides, we propose the temporal context fusion module to adaptively fuse the generated auxiliary predictions. Extensive experiments on public and collected transportation datasets validate that the proposed framework is effective for anomaly detection in time series. Additionally, the ablation study and a series of parameter sensitivity experiments show that the proposed method maintains high performance under various experimental settings.

3.
Cell Tissue Bank ; 24(1): 221-230, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35896934

RESUMO

Feeder cells play important roles in In-vitro culture of stem cells. However, the preparation protocol of feeder cells produced by bovine embryonic fibroblast cells (bEFs) is still lack. In this study, the preparation of bEF-feeder by Mitomycin C was optimized with different concentrations and treatment time. The cell viability of bEFs was detected by CCK8 and 5-Ethynyl-2'-deoxyuridine. The growth of bESCs in each bEFs-feeder group was assessed by alkaline phosphatase staining and CCK8. Quantitative real time PCR was used to detect the mRNA expression of pluripotency-related genes of bESCs. Results showed that the proliferation of bEFs was significantly repressed while bEFs were treated with 14 ug/mL or 16 ug/mL Mitomycin C for 3 h, and the cell viability within 2-4 days after treatment was consistent with the 1st day. The numbers of bESCs clones in bEF-feeder treated with 14 µg/mL Mitomycin C for 3 h or 16 µg/mL Mitomycin C for 3 h were significantly higher than that in bEF-feeder treated with 8 µg/mL Mitomycin C for 8 h or bEFs treated with 6 µg/mL Mitomycin C for 9 h. The mRNA expression of pluripotency-related genes in bESCs cultured by bEF-feeder were higher than the MEF-feeder, the clone morphology of bESCs cultured in bEF-feeder was rounder and sharper than the MEF-feeder. In conclusion, the bEF-feeder prepared with 14 µg/mL Mitomycin C for 3 h or 16 µg/mL Mitomycin C for 3 h could effectively maintains the growth of bESCs, and bEF-feeder is more suitable for bESCs culture than the MEF-feeder.


Assuntos
Técnicas de Cultura de Células , Células Alimentadoras , Fibroblastos , Mitomicina , Células-Tronco Pluripotentes , Bovinos , Sobrevivência Celular/efeitos dos fármacos , Mitomicina/farmacologia , Células-Tronco Pluripotentes/citologia , Animais
4.
Mol Biol Rep ; 49(10): 9297-9305, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35945402

RESUMO

BACKGROUND: Exosomes are involved in intercellular communication, affecting many physiological and pathological process. The present study evaluated the effects of serum exosomes on the function of bovine mammary epithelial cells (BMECs) and milk synthesis under heat stress. METHODS AND RESULTS: We cultured the BMECs in fetal bovine serum (FBS) or exosome-free FBS medium and examined, their viability using CCK-8 kit. The results showed that culturing the cells in an exosome-free medium decreased viability and increased the levels of reactive oxygen species. The BMECs cultured in the exosome-free medium had reduced mitochondrial membrane potential, decreased manganese superoxide dismutase activity, and disrupted mitochondrial dynamics. They exhibited apoptosis due to upregulated Drp1, Fis1, Bax and HSP70. Lastly, we observed downregulation of milk fat and lactoprotein-related genes: mTOR, PPARγ, p-mTOR and ADD1 and SREBP1, ELF5, and CSN2, respectively, after culturing the cells in an exosome-free medium. These negative effects of the exosome-free medium on the BMECs could be further reinforced under heat stress. CONCLUSION: Our results demonstrated that exosomes from serum are critical for maintaining the normal function of BMECs.


Assuntos
Glândulas Mamárias Animais , PPAR gama , Animais , Células Cultivadas , Células Epiteliais , Resposta ao Choque Térmico , Espécies Reativas de Oxigênio/farmacologia , Soroalbumina Bovina/farmacologia , Sincalida/farmacologia , Superóxido Dismutase , Serina-Treonina Quinases TOR , Proteína X Associada a bcl-2
5.
Biosci Biotechnol Biochem ; 86(11): 1506-1514, 2022 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-36066914

RESUMO

Isofurans (IsoFs) are a series of novel discovered lipid peroxidation products. This study focused on the investigation of the angiogenic property of IsoF. MTT stain assay indicated that 1 µm IsoF had the most bioactivity in rat brain endothelial cells (RBECs). IsoF significantly promoted cellular proliferation and migration and remarkably decreased staurosporine-induced apoptosis by TUNEL assay in the RBECs. It successfully up-regulated rat aortic vascularization and choroid explant sprouting, extracellular regulated protein kinases (ERK)1/2, and triggered calcium release. RT-PCR examination indicated that IsoF up-regulated tumor necrosis factor (TNF)α, angiopoietin-1 receptor (Tie2), and vascular endothelial growth factor (VEGF)-A, but did not interfere with caspase 2 and VEGF-C in the RBECs. IsoF has pro-angiogenic activity. Calcium release and ERK1/2 phosphorylation may be involved in the signaling of the IsoF-induced up-regulation of TNFα, Tie2, and VEGF-A, which could be the molecular mechanism of the pro-angiogenic activity of the IsoF.


Assuntos
Angiopoietina-1 , Fator A de Crescimento do Endotélio Vascular , Ratos , Animais , Fator A de Crescimento do Endotélio Vascular/metabolismo , Angiopoietina-1/genética , Fator C de Crescimento do Endotélio Vascular , Caspase 2 , Células Endoteliais/metabolismo , Fator de Necrose Tumoral alfa , Cálcio/metabolismo , Estaurosporina , Neovascularização Fisiológica
6.
Sensors (Basel) ; 22(24)2022 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-36560133

RESUMO

The analysis of infrared spectroscopy of substances is a non-invasive measurement technique that can be used in analytics. Although the main objective of this study is to provide a review of machine learning (ML) algorithms that have been reported for analyzing near-infrared (NIR) spectroscopy from traditional machine learning methods to deep network architectures, we also provide different NIR measurement modes, instruments, signal preprocessing methods, etc. Firstly, four different measurement modes available in NIR are reviewed, different types of NIR instruments are compared, and a summary of NIR data analysis methods is provided. Secondly, the public NIR spectroscopy datasets are briefly discussed, with links provided. Thirdly, the widely used data preprocessing and feature selection algorithms that have been reported for NIR spectroscopy are presented. Then, the majority of the traditional machine learning methods and deep network architectures that are commonly employed are covered. Finally, we conclude that developing the integration of a variety of machine learning algorithms in an efficient and lightweight manner is a significant future research direction.


Assuntos
Algoritmos , Espectroscopia de Luz Próxima ao Infravermelho , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Aprendizado de Máquina , Espectrofotometria Infravermelho , Espectroscopia de Infravermelho com Transformada de Fourier
7.
Angew Chem Int Ed Engl ; 61(32): e202206460, 2022 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-35657722

RESUMO

The discovery and identification of novel active sites are paramount for deepening the understanding of the catalytic mechanism and driving the development of remarkable electrocatalysts. Here, we reveal that the genuine active sites for the hydrogen evolution reaction (HER) in LaRuSi are Si sites, not the usually assumed Ru sites. Ru in LaRuSi has a peculiar negative valence state, which leads to strong hydrogen binding to Ru sites. Surprisingly, the Si sites have a Gibbs free energy of hydrogen adsorption that is near zero (0.063 eV). The moderate adsorption of hydrogen on Si sites during the HER process is also validated by in situ Raman analysis. Based on it, LaRuSi exhibits an overpotential of 72 mV at 10 mA cm-2 in alkaline media, which is close to the benchmark of Pt/C. This work sheds light on the recognition of real active sites and the exploration of innovative silicide HER electrocatalysts.

8.
Angew Chem Int Ed Engl ; 60(43): 23388-23393, 2021 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-34370386

RESUMO

PtSe2 is a typical noble metal dichalcogenide (NMD) that holds promising possibility for next-generation electronics and photonics. However, when applied in hydrogen evolution reaction (HER), it exhibits sluggish kinetics due to the insufficient capability of absorbing active species. Here, we construct PtSe2 /Pt heterointerface to boost the reaction dynamics of PtSe2 , enabled by an in situ electrochemical method. It is found that Se vacancies are induced around the heterointerface, reducing the coordination environment. Correspondingly, the exposed Pt atoms at the very vicinity of Se vacancies are activated, with enhanced overlap with H 1s orbital. The adsorption of H. intermediate is thus strengthened, achieving near thermoneutral free energy change. Consequently, the as-prepared PtSe2 /Pt exhibits extraordinary HER activity even superior to Pt/C, with an overpotential of 42 mV at 10 mA cm-2 and a Tafel slope of 53 mV dec-1 . This work raises attention on NMDs toward HER and provides insights for the rational construction of novel heterointerfaces.

9.
Angew Chem Int Ed Engl ; 60(22): 12360-12365, 2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-33723912

RESUMO

Optimizing the hydrogen adsorption Gibbs free energy (ΔGH ) of active sites is essential to improve the overpotential of the electrocatalytic hydrogen evolution reaction (HER). We doped graphene-like Co0.85 Se with sulfur and found that the active sites are reversed (from cationic Co sites to anionic S sites), which contributed to an enhancement in electrocatalytic HER performance. The optimal S-doped Co0.85 Se composite has an overpotential of 108 mV (at 10 mA cm-2 ) and a Tafel slope of 59 mV dec-1 , which exceeds other reported Co0.85 Se-based electrocatalysts. The doped S sites have much higher activity than the Co sites, with a hydrogen adsorption Gibbs free energy (ΔGH ) close to zero (0.067 eV), which reduces the reaction barrier for hydrogen production. This work provides inspiration for optimizing the intrinsic HER activity of other related transition metal chalcogenides.

10.
Angew Chem Int Ed Engl ; 59(50): 22743-22748, 2020 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-32896011

RESUMO

Vacancy engineering plays vital role in the design of high-performance electrocatalysts. Here, we introduced coupled cation-vacancy pairs in Ni-doped CoSe to achieve boosted hydrogen evolution reaction (HER) activity through a facile topochemical intercalation approach. Adjacent Co vacancy pairs and heteroatom Ni doping contribute together for the upshift of the Se 4pz orbital, which induces larger overlap between the Se 4p and H 1s orbitals. As a result, the free energy of H adsorption can be lowered significantly. With an advanced HER activity of 185.7 mV at 10 mA cm-2 , this work provides new direction and guidance for the design of novel electrocatalysts.

11.
Opt Express ; 27(17): 23763-23774, 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31510276

RESUMO

Light-field near-eye displays can solve the accommodation/convergence conflict problem that can cause severe discomfort to the user. However, in actual systems, convergence depth and accommodation depth may not match each other due to the repeated zones or flipped images produced by traditional light-field methods. Also, Moiré fringes are another problem which is caused by interaction between two periodic structures. We present a method of constructing a light-field near-eye display based on random pinholes, where the random structure is employed as a spatial light modulator to break the periodicity of elemental images. Light-field images for a unique view zone in space without Moiré fringes can be provided. A proof-of-concept prototype has been developed to verify the proposed method.

12.
J Bone Miner Metab ; 37(2): 264-272, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30019248

RESUMO

Osteoblastic differentiation is a complex process that is critical for proper bone formation. An increasing number of studies have suggested that microRNAs (miRNAs) are pivotal regulators in various physiological and pathological processes, including osteogenesis. Here, we discuss the influence of miRNA-92a-1-5p on osteogenic differentiation. We found that miR-92a-1-5p was obviously downregulated during osteogenic differentiation of MC3T3-E1 cells. Gain-of-function and loss-of-function experiments revealed that miR-92a-1-5p was a negative regulator of osteogenic differentiation. Experimental validation demonstrated that ß-catenin, which acts as a positive regulator of osteogenic differentiation, was negatively regulated by miR-92a1-5p. The findings of this study provide new insights into the possibility of miR-92a1-5p being a potential therapeutic target in the management of bone regeneration-related diseases.


Assuntos
Diferenciação Celular/genética , Regulação da Expressão Gênica , MicroRNAs/metabolismo , Osteogênese/genética , beta Catenina/genética , beta Catenina/metabolismo , Animais , Proteína Morfogenética Óssea 2/farmacologia , Calcificação Fisiológica/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Camundongos , MicroRNAs/genética , Osteogênese/efeitos dos fármacos , Transcrição Gênica/efeitos dos fármacos
13.
BMC Musculoskelet Disord ; 20(1): 82, 2019 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-30764802

RESUMO

BACKGROUND: It is very important to dynamically evaluate the functional outcome in the knee after anterior cruciate ligament (ACL) reconstruction under physiological weight bearing. The objective of the current study is that we would like to compare the patellofemoral joint kinematics in three ACL status: ACL intact, ACL deficiency, ACL reconstruction. METHODS: Twenty patients with unilateral ACL deficient knees were recruited as preoperative group. Six months after ACL reconstruction, these ten subjects were included as postoperative subjects. Ten normal subjects with healthy knees as the control group. Each subject was asked to walk up a custom set of stairs and a single-plane fluoroscopic imaging system was used to determine the 6DOF kinematics of the injured knees, ACL reconstructed knees, and intact knees. RESULTS: ACL deficient knees showed reduced patellar flexion angle and reduced distal patellar translation during knee flexion. ACL reconstructed knees showed abnormal patellofemoral joint kinematics compared to ACL intact and ACL deficient knees, exhibiting increased patellar external rotation, lateral tilt, lateral translation during knee flexion. CONCLUSION: These findings imply that some alterations persist after ACL deficiency and ACL reconstruction. These abnormal changes will be the onset of degeneration in patellofemoral joint even if the ACL is reconstructed in a way that restores the clinical anteroposterior stability of the knee. Some biomechanical changes should be made to improve the outcome of intervention especially in surgical treatment like ACL reconstruction.


Assuntos
Lesões do Ligamento Cruzado Anterior/cirurgia , Reconstrução do Ligamento Cruzado Anterior , Ligamento Cruzado Anterior/cirurgia , Articulação Patelofemoral/cirurgia , Adolescente , Adulto , Ligamento Cruzado Anterior/diagnóstico por imagem , Ligamento Cruzado Anterior/fisiopatologia , Lesões do Ligamento Cruzado Anterior/diagnóstico por imagem , Lesões do Ligamento Cruzado Anterior/fisiopatologia , Reconstrução do Ligamento Cruzado Anterior/efeitos adversos , Fenômenos Biomecânicos , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Articulação Patelofemoral/diagnóstico por imagem , Articulação Patelofemoral/fisiopatologia , Amplitude de Movimento Articular , Recuperação de Função Fisiológica , Fatores de Tempo , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Suporte de Carga , Adulto Jovem
14.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 41(6): 578-85, 2016 Jun 28.
Artigo em Zh | MEDLINE | ID: mdl-27374441

RESUMO

OBJECTIVE: To explore the role of DNA methyltransferases (DNMTs) in the pathogenesis of neuropathic pain (NPP) in rats following sciatic nerve chronic constriction injury (CCI).
 METHODS: A total of 27 adult male Sprague-Dawley rats with successful implantation of lumbar intrathecal catheter were randomly divided into 3 groups: a sham + normal saline group (sham+NS group), a CCI+NS group, and a CCI+5-azacytidine group (CCI+5-AZA group) (n=9 in each group). The rats in the Sham+NS group and the CCI+NS group received NS, while the rats in the CCI+5-AZA group received 10 µmol/L of 5-AZA (a DNMTs inhibition) once a day through spinal injection from the 3th day to 14th day after CCI surgery. Mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) of ipsilateral hinds in the 3 groups were measured before or at the 3th, 5th, 7th, 10th or 14th day after CCI surgery. At the end of experiments, all rats were killed under deep anesthesia and their lumbar spinal cords were dissected to examine the DNMT1, DNMT3a and DNMT3b expression by RT-PCR, Western blot and immunohistochemistry, respectively.
 RESULTS: Compared with the sham+NS group, the MWT and TWL in the CCI+NS group were obviously reduced from the 3th day to the 14th day after surgery (both P<0.05). Compared with the CCI+NS group, the MWT and TWL in the CCI+5-AZA group were obviously increased from the 5th day to the 14th day after surgery (both P<0.05), but they were still reduced compared with the sham+NS group (both P<0.05). The DNMT1, DNMT3a and DNMT3b were highly expressed in the lumbar spinal dorsal horn in all rats, and the positive signals were mainly located in the nucleus. The DNMT1, DNMT3a and DNMT3b levels in the CCI+NS group were increased significantly compared with that in the sham+NS group on the 14th day after surgery (all P<0.05). The DNMT1, DNMT3a and DNMT3b expressions in the CCI+ 5-AZA group were decreased significantly compared with that in the CCI+NS group (all P<0.05), but they still increased compared with that in the sham+NS group (all P<0.05). 
 CONCLUSION: Up-regulation of DNMTs in the lumbar spinal may play an important role in the pathogenesis of NPP in CCI rats. DNMTs inhibitors (5-AZA) could reduce expression of DNMTs and attenuate CCI-induced NPP, which might be a potential therapeutic drug for NPP.


Assuntos
Azacitidina , Neuralgia , Animais , Constrição , DNA , DNA (Citosina-5-)-Metiltransferases , Metilação de DNA , Injeções Espinhais , Masculino , Ratos , Ratos Sprague-Dawley , Corno Dorsal da Medula Espinal , Regulação para Cima
15.
Appl Opt ; 54(14): 4478-84, 2015 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-25967505

RESUMO

Photothermal microscopy (PTM), a noninvasive pump-probe high-resolution microscopy, has been applied as a bioimaging tool in many biomedical studies. PTM utilizes a conventional phase contrast microscope to obtain highly resolved photothermal images. However, phase information cannot be extracted from these photothermal images, as they are not quantitative. Moreover, the problem of halos inherent in conventional phase contrast microscopy needs to be tackled. Hence, a digital holographic photothermal microscopy technique is proposed as a solution to obtain quantitative phase images. The proposed technique is demonstrated by extracting phase values of red blood cells from their photothermal images. These phase values can potentially be used to determine the temperature distribution of the photothermal images, which is an important study in live cell monitoring applications.


Assuntos
Rastreamento de Células/instrumentação , Eritrócitos/citologia , Holografia/instrumentação , Microscopia/instrumentação , Termografia/instrumentação , Células Cultivadas , Desenho de Equipamento , Análise de Falha de Equipamento , Humanos , Aumento da Imagem/instrumentação , Lasers de Estado Sólido , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
16.
IEEE Signal Process Mag ; 32(1): 58-69, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26167102

RESUMO

Single molecule microscopy is a relatively new optical microscopy technique that allows the detection of individual molecules such as proteins in a cellular context. This technique has generated significant interest among biologists, biophysicists and biochemists, as it holds the promise to provide novel insights into subcellular processes and structures that otherwise cannot be gained through traditional experimental approaches. Single molecule experiments place stringent demands on experimental and algorithmic tools due to the low signal levels and the presence of significant extraneous noise sources. Consequently, this has necessitated the use of advanced statistical signal and image processing techniques for the design and analysis of single molecule experiments. In this tutorial paper, we provide an overview of single molecule microscopy from early works to current applications and challenges. Specific emphasis will be on the quantitative aspects of this imaging modality, in particular single molecule localization and resolvability, which will be discussed from an information theoretic perspective. We review the stochastic framework for image formation, different types of estimation techniques and expressions for the Fisher information matrix. We also discuss several open problems in the field that demand highly non-trivial signal processing algorithms.

17.
Opt Express ; 22(17): 20396-420, 2014 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-25321248

RESUMO

In fluorescence microscopy, high-speed imaging is often necessary for the proper visualization and analysis of fast subcellular dynamics. Here, we examine how the speed of image acquisition affects the accuracy with which parameters such as the starting position and speed of a microscopic non-stationary fluorescent object can be estimated from the resulting image sequence. Specifically, we use a Fisher information-based performance bound to investigate the detector-dependent effect of frame rate on the accuracy of parameter estimation. We demonstrate that when a charge-coupled device detector is used, the estimation accuracy deteriorates as the frame rate increases beyond a point where the detector's readout noise begins to overwhelm the low number of photons detected in each frame. In contrast, we show that when an electron-multiplying charge-coupled device (EMCCD) detector is used, the estimation accuracy improves with increasing frame rate. In fact, at high frame rates where the low number of photons detected in each frame renders the fluorescent object difficult to detect visually, imaging with an EMCCD detector represents a natural implementation of the Ultrahigh Accuracy Imaging Modality, and enables estimation with an accuracy approaching that which is attainable only when a hypothetical noiseless detector is used.


Assuntos
Diagnóstico por Imagem , Elétrons , Microscopia de Fluorescência/métodos , Fótons , Processamento de Sinais Assistido por Computador/instrumentação , Desenho de Equipamento , Análise de Regressão
18.
Theor Appl Genet ; 127(10): 2095-103, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25212109

RESUMO

KEY MESSAGE: Identification and allele-specific marker development of a functional SNP of HvLox - 1 which associated with barley lipoxygenase activity. Improving the stability of the flavor of beer is one of the main objectives in breeding barley for malting, and lipoxygenase-1 (LOX-1) is a key enzyme controlling this trait. In this study, a modified LOX activity assay was used for null LOX-1 mutant screening. Four barley landraces with no detected level of LOX-1 activity were screened from 1,083 barley germplasm accessions from China. The genomic sequence diversity of the HvLox-1 gene of the four null LOX-1 Chinese landraces was compared with that of a further 76 accessions. A total of 104 nucleotide polymorphisms were found, which contained 83 single-nucleotide polymorphisms (SNPs), 7 multiple-nucleotide polymorphisms, and 14 insertions and deletions. Most notably, we found a rare C/G mutation (SNP-61) in the second intron which led to null LOX-1 activity through an altered splicing acceptor site. In addition, an allele-specific polymerase chain reaction marker was developed for the genotyping of SNP-61, which could be used in breeding programs for barley to be used for malting. The objective was to improve beer quality.


Assuntos
Alelos , Hordeum/genética , Lipoxigenase/metabolismo , Cruzamento , China , Mapeamento Cromossômico , Genótipo , Hordeum/enzimologia , Íntrons , Lipoxigenase/genética , Polimorfismo de Nucleotídeo Único
19.
BMC Med Inform Decis Mak ; 14: 75, 2014 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-25150702

RESUMO

BACKGROUND: The key aim of triage in chest pain patients is to identify those with high risk of adverse cardiac events as they require intensive monitoring and early intervention. In this study, we aim to discover the most relevant variables for risk prediction of major adverse cardiac events (MACE) using clinical signs and heart rate variability. METHODS: A total of 702 chest pain patients at the Emergency Department (ED) of a tertiary hospital in Singapore were included in this study. The recruited patients were at least 30 years of age and who presented to the ED with a primary complaint of non-traumatic chest pain. The primary outcome was a composite of MACE such as death and cardiac arrest within 72 h of arrival at the ED. For each patient, eight clinical signs such as blood pressure and temperature were measured, and a 5-min ECG was recorded to derive heart rate variability parameters. A random forest-based novel method was developed to select the most relevant variables. A geometric distance-based machine learning scoring system was then implemented to derive a risk score from 0 to 100. RESULTS: Out of 702 patients, 29 (4.1%) met the primary outcome. We selected the 3 most relevant variables for predicting MACE, which were systolic blood pressure, the mean RR interval and the mean instantaneous heart rate. The scoring system with these 3 variables produced an area under the curve (AUC) of 0.812, and a cutoff score of 43 gave a sensitivity of 82.8% and specificity of 63.4%, while the scoring system with all the 23 variables had an AUC of 0.736, and a cutoff score of 49 gave a sensitivity of 72.4% and specificity of 63.0%. Conventional thrombolysis in myocardial infarction score and the modified early warning score achieved AUC values of 0.637 and 0.622, respectively. CONCLUSIONS: It is observed that a few predictors outperformed the whole set of variables in predicting MACE within 72 h. We conclude that more predictors do not necessarily guarantee better prediction results. Furthermore, machine learning-based variable selection seems promising in discovering a few relevant and significant measures as predictors.


Assuntos
Dor no Peito/diagnóstico , Serviço Hospitalar de Emergência , Cardiopatias/diagnóstico , Modelos Estatísticos , Triagem/métodos , Idoso , Inteligência Artificial , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico
20.
BMC Complement Altern Med ; 14: 1, 2014 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-24383621

RESUMO

BACKGROUND: Chemicals of herbal products may cause unexpected toxicity or adverse effect by the potential for alteration of the activity of CYP450 when co-administered with other drugs. Eleutherococcus senticosus (ES), has been widely used as a traditional herbal medicine and popular herbal dietary supplements, and often co-administered with many other drugs. The main bioactive constituents of ES were considered to be eleutherosides including eleutheroside B (EB) and eleutheroside E (EE). This study was to investigate the effects of EB and EE on CYP2C9, CYP2D6, CYP2E1 and CYP3A4 in rat liver microsomes in vitro. METHOD: Probe drugs of tolbutamide (TB), dextromethorphan (DM), chlorzoxazone (CLZ) and testosterone (TS) as well as eleutherosides of different concentrations were added to incubation systems of rat liver microsomes in vitro. After incubation, validated HPLC methods were used to quantify relevant metabolites. RESULTS: The results suggested that EB and EE exhibited weak inhibition against the activity of CYP2C9 and CYP2E1, but no effects on CYP2D6 and CYP3A4 activity. The IC50 values for EB and EE were calculated to be 193.20 µM and 188.36 µM for CYP2E1, 595.66 µM and 261.82 µM for CYP2C9, respectively. Kinetic analysis showed that inhibitions of CYP2E1 by EB and EE were best fit to mixed-type with Ki value of 183.95 µM and 171.63 µM, respectively. CONCLUSIONS: These results indicate that EB and EE may inhibit the metabolism of drugs metabolized via CYP2C9 and CYP2E1, and have the potential to increase the toxicity of the drugs.


Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Glucosídeos/farmacologia , Lignanas/farmacologia , Microssomos Hepáticos/enzimologia , Fenilpropionatos/farmacologia , Animais , Clorzoxazona/farmacologia , Citocromo P-450 CYP2C9/metabolismo , Citocromo P-450 CYP2E1/metabolismo , Dextrometorfano/farmacologia , Concentração Inibidora 50 , Cinética , Masculino , Fitoterapia , Ratos , Ratos Wistar , Testosterona/farmacologia , Tolbutamida/farmacologia
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