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The number of meiotic crossovers is tightly controlled and most depend on pro-crossover ZMM proteins, such as the E3 ligase HEI10. Despite the importance of HEI10 dosage for crossover formation, how HEI10 transcription is controlled remains unexplored. In a forward genetic screen using a fluorescent crossover reporter in Arabidopsis thaliana, we identify heat shock factor binding protein (HSBP) as a repressor of HEI10 transcription and crossover numbers. Using genome-wide crossover mapping and cytogenetics, we show that hsbp mutations or meiotic HSBP knockdowns increase ZMM-dependent crossovers toward the telomeres, mirroring the effects of HEI10 overexpression. Through RNA sequencing, DNA methylome, and chromatin immunoprecipitation analysis, we reveal that HSBP is required to repress HEI10 transcription by binding with heat shock factors (HSFs) at the HEI10 promoter and maintaining DNA methylation over the HEI10 5' untranslated region. Our findings provide insights into how the temperature response regulator HSBP restricts meiotic HEI10 transcription and crossover number by attenuating HSF activity.
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Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas Cromosómicas no Histona/genética , Intercambio Genético , Proteínas de Choque Térmico/metabolismo , Respuesta al Choque Térmico/genética , Meiosis/genética , Ubiquitina-Proteína Ligasas/metabolismoRESUMEN
During meiosis, DNA double-strand breaks (DSBs) occur throughout the genome, a subset of which are repaired to form reciprocal crossovers between chromosomes. Crossovers are essential to ensure balanced chromosome segregation and to create new combinations of genetic variation. Meiotic DSBs are formed by a topoisomerase-VI-like complex, containing catalytic (e.g. SPO11) proteins and auxiliary (e.g. PRD3) proteins. Meiotic DSBs are formed in chromatin loops tethered to a linear chromosome axis, but the interrelationship between DSB-promoting factors and the axis is not fully understood. Here, we study the localisation of SPO11-1 and PRD3 during meiosis, and investigate their respective functions in relation to the chromosome axis. Using immunocytogenetics, we observed that the localisation of SPO11-1 overlaps relatively weakly with the chromosome axis and RAD51, a marker of meiotic DSBs, and that SPO11-1 recruitment to chromatin is genetically independent of the axis. In contrast, PRD3 localisation correlates more strongly with RAD51 and the chromosome axis. This indicates that PRD3 likely forms a functional link between SPO11-1 and the chromosome axis to promote meiotic DSB formation. We also uncovered a new function of SPO11-1 in the nucleation of the synaptonemal complex protein ZYP1. We demonstrate that chromosome co-alignment associated with ZYP1 deposition can occur in the absence of DSBs, and is dependent on SPO11-1, but not PRD3. Lastly, we show that the progression of meiosis is influenced by the presence of aberrant chromosomal connections, but not by the absence of DSBs or synapsis. Altogether, our study provides mechanistic insights into the control of meiotic DSB formation and reveals diverse functional interactions between SPO11-1, PRD3 and the chromosome axis.
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Arabidopsis , Arabidopsis/genética , Arabidopsis/metabolismo , Cromatina/genética , Emparejamiento Cromosómico/genética , Cromosomas/metabolismo , Roturas del ADN de Doble Cadena , Endodesoxirribonucleasas/genética , Endodesoxirribonucleasas/metabolismo , Meiosis/genéticaRESUMEN
BACKGROUND & AIMS: Although non-alcoholic fatty liver disease (NAFLD) is becoming a leading cause of hepatocellular carcinoma (HCC), HCC risk in non-cirrhotic NAFLD received little attention. We aimed to develop and validate an HCC risk prediction model for non-cirrhotic NAFLD. METHODS: A nationwide cohort of non-cirrhotic NAFLD patients in Korea was recruited to develop a risk prediction model and validate it internally (n = 409 088). A model using a simplified point system was developed by Cox proportional hazard model. K-fold cross-validation assessed the accuracy, discrimination and calibration. The model was validated externally using a hospital cohort from Asan Medical Center (n = 8721). RESULTS: An 11-point HCC risk prediction model for non-cirrhotic NAFLD was developed using six independent factors of age, sex, diabetes, obesity, serum alanine aminotransferase level and gamma-glutamyl transferase level (c-index 0.75). The average area under receiver operating curves (AUROCs) of the model was 0.72 at 5 years and 0.75 at 10 years. In the external validation cohort, the AUROCs were 0.79 [95% confidence interval [CI], 0.59-0.95] at 5 years and 0.84 (95% CI, 0.73-0.94) at 10 years. The calibration plots showed the expected risks corresponded well with the observed risks. Risk stratification categorized patients into the low (score 0-6), moderate (7, 8) and high (9-11; estimated incidence rate >0.2%/year) risk groups. CONCLUSIONS: A novel HCC risk prediction model for non-cirrhotic NAFLD patients was developed and validated with fair performance. The model is expected to serve as a simple and reliable tool to assess HCC risk and assist precision screening of HCC.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Enfermedad del Hígado Graso no Alcohólico , Humanos , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/epidemiología , Carcinoma Hepatocelular/etiología , Enfermedad del Hígado Graso no Alcohólico/complicaciones , Enfermedad del Hígado Graso no Alcohólico/epidemiología , Enfermedad del Hígado Graso no Alcohólico/patología , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/epidemiología , Neoplasias Hepáticas/etiología , Estudios Retrospectivos , Cirrosis Hepática/complicaciones , Cirrosis Hepática/diagnóstico , Cirrosis Hepática/epidemiología , Factores de Riesgo , FibrosisRESUMEN
This study aims to explore the anti-inflammatory mechanisms of sargachromenol in both RAW 264.7 cells and lipopolysaccharide (LPS)-treated mice, as previous reports have suggested that sargachromenol possesses anti-aging, anti-inflammatory, antioxidant, and neuroprotective properties. Although the precise mechanism behind its anti-inflammatory activity remains unclear, pretreatment with sargachromenol effectively reduced the production of nitric oxide, prostaglandin E2, and interleukin (IL)-1ß in LPS-stimulated RAW 264.7 cells by inhibiting cyclooxygenase-2. Moreover, sargachromenol inhibited the activation of nuclear factor-κB (NF-κB) by preventing the degradation of the inhibitor of κB-α (IκB-α) and inhibiting protein kinase B (Akt) phosphorylation in LPS-stimulated cells. We also found that sargachromenol induced the production of heme oxygenase-1 (HO-1) by activating the nuclear transcription factor erythroid-2-related factor 2 (Nrf2). In LPS-treated mice, oral administration of sargachromenol effectively reduced the levels of IL-1ß, IL-6, and tumor necrosis factor-α (TNF-α) in the serum, suggesting its ability to suppress the production of inflammatory mediators by inhibiting the Akt/NF-κB pathway and upregulating the Nrf2/HO-1 pathway.
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Lipopolisacáridos , FN-kappa B , Animales , Ratones , FN-kappa B/metabolismo , Células RAW 264.7 , Lipopolisacáridos/farmacología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Antiinflamatorios/farmacología , Hemo-Oxigenasa 1/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo II/metabolismo , Ciclooxigenasa 2/metabolismoRESUMEN
The aims of the study are to evaluate idiopathic normal-pressure hydrocephalus (INPH)-related cerebral blood flow (CBF) abnormalities and to investigate their relation to cortical thickness in INPH patients. We investigated cortical CBF utilizing surface-based early-phase 18 F-florbetaben (E-FBB) PET analysis in two groups: INPH patients and healthy controls. All 39 INPH patients and 20 healthy controls were imaged with MRI, including three-dimensional volumetric images, for automated surface-based cortical thickness analysis across the entire brain. A subgroup with 37 participants (22 INPH patients and 15 healthy controls) that also underwent 18 F-fluorodeoxyglucose (FDG) PET imaging was further analyzed. Compared with age- and gender-matched healthy controls, INPH patients showed statistically significant hyperperfusion in the high convexity of the frontal and parietal cortical regions. Importantly, within the INPH group, increased perfusion correlated with cortical thickening in these regions. Additionally, significant hypoperfusion mainly in the ventrolateral frontal cortex, supramarginal gyrus, and temporal cortical regions was observed in the INPH group relative to the control group. However, this hypoperfusion was not associated with cortical thinning. A subgroup analysis of participants that also underwent FDG PET imaging showed that increased (or decreased) cerebral perfusion was associated with increased (or decreased) glucose metabolism in INPH. A distinctive regional relationship between cerebral cortical perfusion and cortical thickness was shown in INPH patients. Our findings suggest distinct pathophysiologic mechanisms of hyperperfusion and hypoperfusion in INPH patients.
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Fluorodesoxiglucosa F18 , Hidrocéfalo Normotenso , Humanos , Hidrocéfalo Normotenso/diagnóstico por imagen , Corteza Cerebral/diagnóstico por imagen , Tomografía de Emisión de Positrones/métodos , Encéfalo , Imagen por Resonancia MagnéticaRESUMEN
The limited availability of treatments for many infectious diseases highlights the need for new treatments, particularly for viral infections. Natural compounds from seaweed are attracting increasing attention for the treatment of various viral diseases, and thousands of novel compounds have been isolated for the development of pharmaceutical products. Seaweed is a rich source of natural bioactive compounds, including polysaccharides. The discovery of algal polysaccharides with antiviral activity has significantly increased in the past few decades. Furthermore, unique polysaccharides isolated from seaweeds, such as carrageenan, alginates, fucoidans, galactans, laminarians, and ulvans, have been shown to act against viral infections. The antiviral mechanisms of these agents are based on their inhibition of DNA or RNA synthesis, viral entry, and viral replication. In this article, we review and provide an inclusive description of the antiviral activities of algal polysaccharides. Additionally, we discuss the challenges and opportunities for developing polysaccharide-based antiviral therapies, including issues related to drug delivery and formulation. Finally, this review highlights the need for further research for fully understanding the potential of seaweed polysaccharides as a source of antiviral agents and for developing effective treatments for viral diseases.
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The skin is the outermost anatomical barrier, which plays a vital role in the maintenance of internal homeostasis and protection against physical, chemical, and biological detractors. Direct contact with various stimuli leads to several physiological changes that are ultimately important for the growth of the cosmetic industry. Due to the consequences of using synthetic compounds in skincare and cosmeceutical-related industries, the pharmaceutical and scientific communities have recently shifted their focus to natural ingredients. The nutrient-rich value of algae, which are some of the most interesting organisms in marine ecosystems, has attracted attention. Secondary metabolites isolated from seaweeds are potential candidates for a wide range of economic applications, including food, pharmaceuticals, and cosmetics. An increasing number of studies have focused on polyphenol compounds owing to their promising biological activities against oxidation, inflammation, allergies, cancers, melanogenesis, aging, and wrinkles. This review summarizes the potential evidence of the beneficial properties and future perspectives of using marine macroalgae-derived polyphenolic compounds for advancing the cosmetic industry.
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Cosméticos , Algas Marinas , Polifenoles/farmacología , Ecosistema , Cosméticos/farmacología , Cosméticos/química , Algas Marinas/química , Sustancias ProtectorasRESUMEN
In the medical field, it is delicate to anticipate good performance in using deep learning due to the lack of large-scale training data and class imbalance. In particular, ultrasound, which is a key breast cancer diagnosis method, is delicate to diagnose accurately as the quality and interpretation of images can vary depending on the operator's experience and proficiency. Therefore, computer-aided diagnosis technology can facilitate diagnosis by visualizing abnormal information such as tumors and masses in ultrasound images. In this study, we implemented deep learning-based anomaly detection methods for breast ultrasound images and validated their effectiveness in detecting abnormal regions. Herein, we specifically compared the sliced-Wasserstein autoencoder with two representative unsupervised learning models autoencoder and variational autoencoder. The anomalous region detection performance is estimated with the normal region labels. Our experimental results showed that the sliced-Wasserstein autoencoder model outperformed the anomaly detection performance of others. However, anomaly detection using the reconstruction-based approach may not be effective because of the occurrence of numerous false-positive values. In the following studies, reducing these false positives becomes an important challenge.
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Aprendizaje Profundo , Ultrasonografía Mamaria , Femenino , Humanos , Ultrasonografía Mamaria/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Ultrasonografía , Diagnóstico por Computador/métodosRESUMEN
BACKGROUND: Determination of implant size is crucial for patients with breast cancer undergoing one-stage breast reconstruction. The purpose of this study is to predict the implant size based on the breast volume measured by mammography (MG) with a fully automated method, and by breast magnetic resonance imaging (MRI) with a semi-automated method, in breast cancer patients with direct-to-implant reconstruction. PATIENTS AND METHODS: This retrospective study included 84 patients with breast cancer who underwent direct-to-implant reconstruction after nipple-sparing or skin-sparing mastectomy and preoperative MG and MRI between April 2015 and April 2019. Breast volume was measured using (a) MG with a fully automated commercial software and (b) MRI with an in-house semi-automated software program. Multivariable regression analyses including breast volume and patient weight (P < 0.05 in univariable analysis) were conducted to predict implant size. RESULTS: MG and MRI breast volume was highly correlated with both implant size (correlation coefficient 0.862 and 0.867, respectively; P values < 0.001) and specimen weight (correlation coefficient 0.802 and 0.852, respectively; P values < 0.001). Mean absolute difference between the MR breast volume and implant size was 160 cc, which was significantly higher than that between the MG breast volume and implant size of 118 cc (P < 0.001). On multivariable analyses, only breast volume measured by both MG and MRI was significantly associated with implant size in any implant type (all P values < 0.001). CONCLUSION: Breast volume measured by MG and MRI can be used to predict appropriate implant size in breast cancer patients undergoing direct-to-implant reconstruction in an efficient and objective manner.
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Implantes de Mama , Neoplasias de la Mama , Mamoplastia , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/cirugía , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Mamoplastia/métodos , Mamografía , Mastectomía/métodos , Pezones/cirugía , Estudios RetrospectivosRESUMEN
BACKGROUND AND AIM: Evidence has emerged that a pretreatment immune profile in rectal cancer is associated with response to chemoradiotherapy (CRT) and recurrence after CRT. However, few studies have evaluated the immune profile differences after CRT regarding recurrence and nonrecurrence. METHODS: We included patients with advanced rectal cancer treated with CRT and surgery with recurrence within 1 year in a recurrence group. After sex and age matching with the recurrence group, patients with no recurrence for 3 years after CRT were included in a nonrecurrence group. We extracted the immune profile, including CD3 and CD8, from the surgical specimen after CRT using multispectral fluorescence immunohistochemistry and compared the two groups. RESULTS: The immune profiles of 65 patients with rectal cancer were assessed; 30 were included in the recurrence group and 35 were included in the nonrecurrence group. CD3+ and CD8+ T lymphocyte densities were significantly higher in the nonrecurrence group than in the recurrence group (CD3+ ; P < 0.001, CD8+ ; P = 0.003) in the primary tumor. Consistent results were found in epithelial and stromal cells. Compared with the recurrence group, the distinct profiles of co-expressed immune markers in the nonrecurrence group were revealed (CD3+ CD8+ , P = 0.001; CD3+ CD8+ PD-L1- , P = 0.001; CD3+ CD8+ FOXP3- PD-L1- , P = 0.001). CONCLUSIONS: Vigorous CD3+ and CD8+ T cell priming post-CRT was prominent in the nonrecurrence group compared with that of the recurrence group. This finding suggests that differences in immune profiles may have clinical significance even after CRT.
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Quimioradioterapia , Neoplasias del Recto , Femenino , Humanos , Inmunohistoquímica , Masculino , Recurrencia Local de Neoplasia , Neoplasias del Recto/metabolismo , Neoplasias del Recto/patología , Neoplasias del Recto/terapia , Resultado del TratamientoRESUMEN
Coagulation is a potential defense mechanism that involves activating a series of zymogens to convert soluble fibrinogen to insoluble fibrin clots to prevent bleeding and hemorrhagic complications. To prevent the extra formation and diffusion of clots, the counterbalance inhibitory mechanism is activated at levels of the coagulation pathway. Contrariwise, this system can evade normal control due to either inherited or acquired defects or aging which leads to unusual clots formation. The abnormal formations and deposition of excess fibrin trigger serious arterial and cardiovascular diseases. Although heparin and heparin-based anticoagulants are a widely prescribed class of anticoagulants, the clinical use of heparin has limitations due to the unpredictable anticoagulation, risk of bleeding, and other complications. Hence, significant interest has been established over the years to investigate alternative therapeutic anticoagulants from natural sources, especially from marine sources with good safety and potency due to their unique chemical structure and biological activity. This review summarizes the coagulation cascade and potential macromolecular anticoagulants derived from marine flora and fauna.
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Anticoagulantes , Trombosis , Humanos , Anticoagulantes/farmacología , Anticoagulantes/uso terapéutico , Heparina/farmacología , Hemorragia/inducido químicamente , Hemorragia/tratamiento farmacológico , Hemorragia/prevención & control , Trombosis/tratamiento farmacológico , Fibrina , Fibrinógeno , Precursores EnzimáticosRESUMEN
Meiotic crossovers facilitate chromosome segregation and create new combinations of alleles in gametes. Crossover frequency varies along chromosomes and crossover interference limits the coincidence of closely spaced crossovers. Crossovers can be measured by observing the inheritance of linked transgenes expressing different colors of fluorescent protein in Arabidopsis pollen tetrads. Here we establish DeepTetrad, a deep learning-based image recognition package for pollen tetrad analysis that enables high-throughput measurements of crossover frequency and interference in individual plants. DeepTetrad will accelerate the genetic dissection of mechanisms that control meiotic recombination.
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Arabidopsis/genética , Aprendizaje Profundo , Meiosis , Alelos , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Segregación Cromosómica , Cromosomas de las Plantas , Intercambio Genético/genética , Intercambio Genético/fisiología , Recombinación Homóloga , Polen/genética , TransgenesRESUMEN
Paired Box (Pax) gene family, a group of transcription regulators have been implicated in diverse physiological processes. However, their role during hematopoiesis which generate a plethora of blood cells remains largely unknown. Using a previously reported single cell transcriptomics data, we analyzed the expression of individual Pax family members in hematopoietic cells in zebrafish. We have identified that Pax9, which is an essential regulator for odontogenesis and palatogenesis, is selectively localized within a single cluster of the hematopoietic lineage. To further analyze the function of Pax9 in hematopoiesis, we generated two independent pax9 knock-out mutants using the CRISPR-Cas9 technique. We found that Pax9 appears to be an essential regulator for granulopoiesis but dispensable for erythropoiesis during development, as lack of pax9 selectively decreased the number of neutrophils with a concomitant decrease in the expression level of neutrophil markers. In addition, embryos, where pax9 was functionally disrupted by injecting morpholinos, failed to increase the number of neutrophils in response to pathogenic bacteria, suggesting that Pax9 is not only essential for developmental granulopoiesis but also emergency granulopoiesis. Due to the inability to initiate emergency granulopoiesis, innate immune responses were severely compromised in pax9 morpholino-mediated embryos, increasing their susceptibility and mortality. Taken together, our data indicate that Pax9 is essential for granulopoiesis and promotes innate immunity in zebrafish larvae.
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Eritropoyesis/inmunología , Mielopoyesis/inmunología , Factor de Transcripción PAX9/inmunología , Proteínas de Pez Cebra/inmunología , Pez Cebra/inmunología , Animales , Animales Modificados Genéticamente , Infecciones Bacterianas/inmunología , Sistemas CRISPR-Cas , Eritropoyesis/genética , Regulación del Desarrollo de la Expresión Génica , Técnicas de Inactivación de Genes , Granulocitos/inmunología , Inmunidad Innata/genética , Inmunidad Innata/fisiología , Mielopoyesis/genética , Factor de Transcripción PAX9/deficiencia , Factor de Transcripción PAX9/genética , Pez Cebra/embriología , Pez Cebra/genética , Proteínas de Pez Cebra/deficiencia , Proteínas de Pez Cebra/genéticaRESUMEN
Meiotic recombination initiates from DNA double-strand breaks (DSBs) generated by SPO11 topoisomerase-like complexes. Meiotic DSB frequency varies extensively along eukaryotic chromosomes, with hotspots controlled by chromatin and DNA sequence. To map meiotic DSBs throughout a plant genome, we purified and sequenced Arabidopsis thaliana SPO11-1-oligonucleotides. SPO11-1-oligos are elevated in gene promoters, terminators, and introns, which is driven by AT-sequence richness that excludes nucleosomes and allows SPO11-1 access. A positive relationship was observed between SPO11-1-oligos and crossovers genome-wide, although fine-scale correlations were weaker. This may reflect the influence of interhomolog polymorphism on crossover formation, downstream from DSB formation. Although H3K4me3 is enriched in proximity to SPO11-1-oligo hotspots at gene 5' ends, H3K4me3 levels do not correlate with DSBs. Repetitive transposons are thought to be recombination silenced during meiosis, to prevent nonallelic interactions and genome instability. Unexpectedly, we found high SPO11-1-oligo levels in nucleosome-depleted Helitron/Pogo/Tc1/Mariner DNA transposons, whereas retrotransposons were coldspots. High SPO11-1-oligo transposons are enriched within gene regulatory regions and in proximity to immunity genes, suggesting a role as recombination enhancers. As transposon mobility in plant genomes is restricted by DNA methylation, we used the met1 DNA methyltransferase mutant to investigate the role of heterochromatin in SPO11-1-oligo distributions. Epigenetic activation of meiotic DSBs in proximity to centromeres and transposons occurred in met1 mutants, coincident with reduced nucleosome occupancy, gain of transcription, and H3K4me3. Together, our work reveals a complex relationship between chromatin and meiotic DSBs within A. thaliana genes and transposons, with significance for the diversity and evolution of plant genomes.
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Proteínas de Arabidopsis/genética , Arabidopsis/genética , Metilación de ADN/genética , Nucleosomas/genética , Cromosomas Fúngicos , Roturas del ADN de Doble Cadena , Elementos Transponibles de ADN/genética , Epigénesis Genética/genética , Meiosis/genética , Secuencias Reguladoras de Ácidos Nucleicos/genéticaRESUMEN
Recently, the amount of attention paid towards convolutional neural networks (CNN) in medical image analysis has rapidly increased since they can analyze and classify images faster and more accurately than human abilities. As a result, CNNs are becoming more popular and play a role as a supplementary assistant for healthcare professionals. Using the CNN on portable medical devices can enable a handy and accurate disease diagnosis. Unfortunately, however, the CNNs require high-performance computing resources as they involve a significant amount of computation to process big data. Thus, they are limited to being used on portable medical devices with limited computing resources. This paper discusses the network quantization techniques that reduce the size of CNN models and enable fast CNN inference with an energy-efficient CNN accelerator integrated into recent mobile processors. With extensive experiments, we show that the quantization technique reduces inference time by 97% on the mobile system integrating a CNN acceleration engine.
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Redes Neurales de la Computación , HumanosRESUMEN
The first postnatal years are an exceptionally dynamic and critical period of structural, functional and connectivity development of the human brain. The increasing availability of non-invasive infant brain MR images provides unprecedented opportunities for accurate and reliable charting of dynamic early brain developmental trajectories in understanding normative and aberrant growth. However, infant brain MR images typically exhibit reduced tissue contrast (especially around 6 months of age), large within-tissue intensity variations, and regionally-heterogeneous, dynamic changes, in comparison with adult brain MR images. Consequently, the existing computational tools developed typically for adult brains are not suitable for infant brain MR image processing. To address these challenges, many infant-tailored computational methods have been proposed for computational neuroanatomy of infant brains. In this review paper, we provide a comprehensive review of the state-of-the-art computational methods for infant brain MRI processing and analysis, which have advanced our understanding of early postnatal brain development. We also summarize publically available infant-dedicated resources, including MRI datasets, computational tools, grand challenges, and brain atlases. Finally, we discuss the limitations in current research and suggest potential future research directions.
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Encéfalo/crecimiento & desarrollo , Procesamiento de Imagen Asistido por Computador/métodos , Neuroanatomía/métodos , Neuroimagen/métodos , Atlas como Asunto , Simulación por Computador , Femenino , Humanos , Lactante , Recién Nacido , Imagen por Resonancia Magnética/métodos , Masculino , Modelos TeóricosRESUMEN
Fish bone, a by-product of fishery processing, is composed of protein, calcium, and other minerals. The objective of this study was to investigate the effects of a bioactive peptide isolated from the bone of the marine fish, Johnius belengerii, on the osteoblastic differentiation of MC3T3-E1 pre-osteoblasts. Post consecutive purification by liquid chromatography, a potent osteogenic peptide, composed of 3 amino acids, Lys-Ser-Ala (KSA, MW: 304.17 Da), was identified. The purified peptide promoted cell proliferation, alkaline phosphatase activity, mineral deposition, and expression levels of phenotypic markers of osteoblastic differentiation in MC3T3-E1 pre-osteoblast. The purified peptide induced phosphorylation of mitogen-activated protein kinases, including p38 mitogen-activated protein kinase, extracellular regulated kinase, and c-Jun N-terminal kinase as well as Smads. As attested by molecular modelling study, the purified peptide interacted with the core interface residues in bone morphogenetic protein receptors with high affinity. Thus, the purified peptide could serve as a potential pharmacological substance for controlling bone metabolism.
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Proteína Morfogenética Ósea 2/metabolismo , Huesos/química , Proteínas de Peces/farmacología , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Osteoblastos/efectos de los fármacos , Osteogénesis/efectos de los fármacos , Proteínas Smad/metabolismo , Células 3T3 , Animales , Diferenciación Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Proteínas de Peces/aislamiento & purificación , Gadiformes , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Ratones , Modelos Moleculares , Osteoblastos/citología , Osteoblastos/metabolismo , Regulación hacia Arriba/efectos de los fármacosRESUMEN
The aim of this study is to evaluate the localization of 99mTc-labeled dextran-coated superparamagnetic iron oxide (SPIO) nanoparticles to the liver tumor using image-based analysis. We delivered 99mTc-SPIO intravenously or intra-arterially (IA) with/without Lipiodol to compare the tumor localization by gamma scintigraphy, single-photon emission computed tomography (SPECT), and magnetic resonance imaging (MRI) in a rabbit liver tumor. The gamma and SPECT image-based analysis shows that the uptake ratio of the tumor to the normal liver parenchyma is highest after delivery of 99mTc-SPIO with Lipiodol IA and that well correlates with the trend of the signal decrease in the liver MRIs. Intra-arterial delivery of SPIO with Lipiodol might be a good drug delivery system targeting the hepatic tumors, as confirmed by image-based analysis.
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Infusiones Intraarteriales/métodos , Imagen por Resonancia Magnética/métodos , Tecnecio/análisis , Tomografía Computarizada de Emisión de Fotón Único/métodos , Animales , Medios de Contraste , ConejosRESUMEN
Atlases constructed using diffusion-weighted imaging are important tools for studying human brain development. Atlas construction is in general a two-step process involving spatial registration and fusion of individual images. The focus of most studies so far has been on improving the accuracy of registration while image fusion is commonly performed using simple averaging, often resulting in fuzzy atlases. In this article, we propose a patch-based method for diffusion-weighted (DW) atlas construction. Unlike other atlases that are based on the diffusion tensor model, our atlas is model-free and generated directly from the diffusion-weighted images. Instead of independently generating an atlas for each gradient direction and hence neglecting angular image correlation, we propose to construct the atlas by jointly considering DW images of neighboring gradient directions. We employ a group regularization framework where local patches of angularly neighboring images are constrained for consistent spatio-angular atlas reconstruction. Experimental results confirm that our atlas, constructed for neonatal data, reveals more structural details with higher fractional anisotropy than the atlas generated without angular consistency as well as the average atlas. Also the normalization of test subjects to the proposed atlas results in better alignment of brain structures. Hum Brain Mapp 38:3175-3189, 2017. © 2017 Wiley Periodicals, Inc.