RESUMEN
The accurate whole heart segmentation (WHS) of multi-modality medical images including magnetic resonance image (MRI) and computed tomography (CT) plays an important role in many clinical applications, such as accurate preoperative diagnosis planning and intraoperative treatment. Considering that the shape information of each component of the whole heart is complementary, we can extract multi-modality features and obtain the final segmentation results by fusing MRI and CT images. In this paper, we proposed a multi-modality transfer learning network with adversarial training (MMTLNet) for 3D multi-modality whole heart segmentation. Firstly, the network transfers the source domain (MRI domain) to the target domain (CT domain) by reconstructing the MRI images with a generator network and optimizing the reconstructed MRI images with a discriminator network, which enables us to fuse the MRI images with CT images to fully utilize the useful information from images in multi-modality for segmentation task. Secondly, to retain the useful information and remove the redundant information for accurate segmentation, we introduce the spatial attention mechanism into the backbone connection of UNet network to optimize the feature extraction between layers, and add channel attention mechanism at the jump connection to optimize the information extracted from the low-level feature map. Thirdly, we propose a new loss function in the adversarial training by introducing a weighted coefficient to distribute the proportion between Dice coefficient loss and generator loss, which can not only ensure the images to be correctly transferred from MRI domain to CT domain, but also achieve accurate segmentation with the transferred domain. We extensively evaluated our method on the data set of the multi-modality whole heart segmentation (MM-WHS) challenge, in conjunction with MICCAI 2017. The dice values of whole heart segmentation are 0.914 (CT images) and 0.890 (MRI images), which are both higher than the state-of-the-art.
Asunto(s)
Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Aprendizaje Automático , Tomografía Computarizada por Rayos XRESUMEN
Poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt(4,4'-(N-(4-butylphenyl)))] (TFB) has been widely used as a hole transport layer (HTL) material in cadmium-based quantum dot light-emitting diodes (QLEDs) because of its high hole mobility. However, as the highest occupied molecular orbital (HOMO) energy level of TFB is -5.4 eV, the hole injection from TFB to the quantum dot (QD) layer is higher than 1.5 eV. Such a high oxidation potential at the QD/HTL interface may seriously degrade the device lifetime. In addition, TFB is not resistant to most solvents, which limits its application in inkjet-printed QLED display. In this study, the blended HTL consisting of TFB and cross-linkable small molecular 4,4'-bis(3-vinyl-9H-carbazol-9-yl)1,1'-biphenyl (CBP-V) was introduced into red QLEDs because of the deep HOMO energy level of CBP-V (-6.2 eV). Compared with the TFB-only devices, the external quantum efficiency (EQE) of devices with the blended HTL improved from 15.9 to 22.3% without the increase of turn-on voltage for spin-coating-fabricated devices. Furthermore, the blended HTL prolonged the T90 and T70 lifetime from 5.4 and 31.1 to 39.4 and 148.9 h, respectively. These enhancements in lifetime are attributed to the low hole-injection barrier at the HTL/QD interface and high thermal stability of the blended HTL after cross-linking. Moreover, the cross-linked blended HTL showed excellent solvent resistance after cross-linking, and the EQE of the inkjet-printed red QLEDs reached 16.9%.
RESUMEN
Quantum dots light-emitting diodes (QLEDs) have attracted much interest owing to their compatibility with low-cost inkjet printing technology and potential for use in large-area full-color pixelated display. However, it is challenging to fabricate high efficiency inkjet-printed QLEDs because of the coffee ring effects and inferior resistance to solvents from the underlying polymer film during the inkjet printing process. In this study, a novel crosslinkable hole transport material, 4,4'-bis(3-vinyl-9H-carbazol-9-yl)-1,1'-biphenyl (CBP-V) which is small-molecule based, is synthesized and investigated for inkjet printing of QLEDs. The resulting CBP-V film after thermal curing exhibits excellent solvent resistance properties without any initiators. An added advantage is that the crosslinked CBP-V film has a sufficiently low highest occupied molecular orbital energy level (≈-6.2 eV), high film compactness, and high hole mobility, which can thus promote the hole injection into quantum dots (QDs) and improve the charge carrier balance within the QD emitting layers. A red QLED is successfully fabricated by inkjet printing a CBP-V and QDs bilayer. Maximum external quantum efficiency of 11.6% is achieved, which is 92% of a reference spin-coated QLED (12.6%). This is the first report of such high-efficiency inkjet-printed multilayer QLEDs and demonstrates a unique and effective approach to inkjet printing fabrication of high-performance QLEDs.
RESUMEN
In order to explore how the modification of succinic acid improves the adsorption of tea oil tree sawdust for uranium, the tea oil tree sawdust was modified by succinic acid, after the pretreatments of crushing, screening, alkalization and acidification. Infrared analysis indicated carboxylic acid groups and ester groups were added to the sawdust after modification, and scanning electron microscope demonstrated after modification the appearance of tea oil tree sawdust was transferred from the structure like compact and straight stripped into the structure like loose and wrinkled leaves, which meant modification increased its inner pores. By the static experiments, effects of reaction time between adsorbent and solvent, dosage of adsorbent, temperature, pH value and initial concentration of uranium were investigated. The results showed that after the modification by succinic acid, the absorption rate of tea oil tree sawdust for uranium increased significantly by about 20% in 12.5 mg · L(-1) initial concentration uranium solution. Adsorption equilibrium was achieved within 180 min, and the kinetic data can be well described by the pseudo-second-order kinetic model. The experimental adsorption isotherm followed the Langmuir and Freundlich models. In addition, the maximum adsorption amounts of tea oil tree sawdust after modification calculated from Langmuir equation raised from 21.413 3 to 31.545 7 mg · g(-1) at 35°C and pH 4.0.
Asunto(s)
Melaleuca , Ácido Succínico/química , Uranio/química , Madera , Adsorción , Concentración de Iones de Hidrógeno , Cinética , Soluciones , Temperatura , ÁrbolesRESUMEN
Behavioral sensitization of psychostimulants was accompanied by alterations in a variety of biochemical molecules in different brain regions. However, which change is actually related to drug-produced sensitization lacks of accurate clarification. In this study, we investigated the role of integrin-linked kinase (ILK) in both the induction and expression of cocaine sensitization. Conditional inhibition of ILK expression was established in the nucleus accumbens (NAc) core by microinjecting recombinant adeno-associated virus-carrying, tetracycline-on-regulated small interfering RNA which reversed the chronic cocaine-induced psychomotor sensitization, as well as the changes in protein kinase B Ser473 phosphorylation, dendritic density, and dendritic spine numbers locally. Importantly, the reversed psychomotor sensitization did not recover after cessation of the silencing for 8 days. We also demonstrated that inhibition of ILK expression pre- and during-chronic cocaine treatments blocked the induction of cocaine psychomotor sensitization and abolished the stimulant effect of cocaine on ILK expression. In contrast, inhibition of ILK expression in the NAc core has no significant effect on cocaine-induced stereotypical behaviors. This concludes that ILK is involved in cocaine sensitization with the earlier induction and later expression functioning as a kinase to regulate protein kinase B Ser473 phosphorylation and a scaffolding protein to regulate the reorganization of the NAc spine morphology.
Asunto(s)
Conducta Adictiva/metabolismo , Trastornos Relacionados con Cocaína/metabolismo , Cocaína/farmacología , Inhibidores de Captación de Dopamina/farmacología , Plasticidad Neuronal/efectos de los fármacos , Proteínas Serina-Treonina Quinasas/metabolismo , Animales , Conducta Adictiva/fisiopatología , Western Blotting , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Encéfalo/fisiopatología , Trastornos Relacionados con Cocaína/fisiopatología , Dendritas/efectos de los fármacos , Técnica del Anticuerpo Fluorescente , Masculino , Plasticidad Neuronal/fisiología , Fosforilación/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt/metabolismo , ARN Interferente Pequeño , Ratas , Ratas Sprague-DawleyRESUMEN
In this study we established conditional silencing of integrin-linked kinase (ILK) expression in Sprague-Dawley rat brain by microinjection of rAAV-2-carrying, Tet-On-regulated siRNA expression cassette into nucleus accumbens (NAc) core and induction with doxycycline. We demonstrated that inhibition of ILK expression was effectively induced by administration of doxycycline for 2 weeks while ILK expression was restored after withdrawing doxycycline for 8 days. Increases in GFAP and OX42 expression were observed 5 weeks post virus injection. Importantly, inhibition of ILK expression in the NAc core had no significant effect on cell apoptosis and animal basal locomotion and stereotypical behaviors, but decreased dendritic density of medium spiny neurons. Our studies suggest that: (1) rAAV-delivered Tet-On-regulated siRNA expression can conditionally regulate gene expression in rat brain; (2) inhibition of ILK expression has no significant effect on cell apoptosis and basal locomotor and stereotypical behaviors, but decreases dendritic density; and (3) microinjection of rAAV-2 causes inflammatory response around the injection track.
Asunto(s)
Silenciador del Gen/fisiología , Marcación de Gen/métodos , Vectores Genéticos/genética , Biología Molecular/métodos , Núcleo Accumbens/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Animales , Antibacterianos/farmacología , Apoptosis/efectos de los fármacos , Apoptosis/genética , Espinas Dendríticas/fisiología , Espinas Dendríticas/ultraestructura , Dependovirus/genética , Doxiciclina/farmacología , Encefalitis/inducido químicamente , Encefalitis/genética , Técnica del Anticuerpo Fluorescente , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Regulación Enzimológica de la Expresión Génica/genética , Masculino , Microinyecciones/efectos adversos , Actividad Motora/efectos de los fármacos , Actividad Motora/genética , Neuronas/citología , Neuronas/fisiología , Interferencia de ARN/fisiología , ARN Interferente Pequeño/genética , Ratas , Ratas Sprague-Dawley , Conducta Estereotipada/efectos de los fármacos , Conducta Estereotipada/fisiologíaRESUMEN
Deprenyl, used clinically in Parkinson's disease, has multiple pharmacological effects which make it a good candidate to treat neurotoxicity. Thus, we investigated deprenyl's ability to attenuate methamphetamine-induced dopamine neurotoxicity. We also examined deprenyl's effect in changing markers associated with psychostimulant sensitization. A potential therapeutic effect on either pathological domain would be a boon in developing novel treatments for methamphetamine abuse. Adult male Sprague-Dawley rats were split into 6 groups. Three groups received a 7-day saline minipump with saline, 0.05 or 0.25 mg/kg SC deprenyl injections given for 10 days before, during and 5 days after the 7-day saline minipump implant. Similarly, 3 groups received methamphetamine pumps (25 mg/kg/day) with escalating daily injections of methamphetamine (0-6 mg/kg) in addition to the minipump treatment. These rats also received saline, 0.05 or 0.25 mg/kg deprenyl injections given before, during and the 7-day minipump treatment. Rats were killed on day 28 of withdrawal and brain samples taken. HPLC analysis for dopamine and 3,4-Dihydroxy-Phenylacetic Acid (DOPAC) revealed a loss of dopamine in the caudate and accumbens which was partially reversed by high dose deprenyl. Tyrosine hydroxylase immunostaining in the midbrain was unaffected by methamphetamine, suggesting that dopamine neurotoxicity was localized to the caudate. Western blot analysis of the caudate after methamphetamine revealed little change in Alpha-Amino-3-Hydroxy-5-Methyl-4-Isoxazole Propionic Acid (AMPA) GluR1 or N-Methyl-d-Aspartate (NMDA) NR2B subunits, or their phosphorylation state. However, methamphetamine increased levels of GluR1 and its phosphorylation state in the prefrontal cortex (PFC), and these increases were attenuated by deprenyl. Methamphetamine also increased levels of PFC NR2B subunit, but these increases were not attenuated by deprenyl. We suggest that deprenyl may be effective in reducing the neurotoxic effects of methamphetamine and may also attenuate changes in prefrontal AMPA receptor function, presumably more associated with addiction rather than neurotoxicity.
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Metanfetamina/toxicidad , Selegilina/farmacología , Sinapsis/efectos de los fármacos , Ácido 3,4-Dihidroxifenilacético/análisis , Ácido 3,4-Dihidroxifenilacético/metabolismo , Animales , Antiparkinsonianos/administración & dosificación , Antiparkinsonianos/farmacología , Western Blotting , Peso Corporal/efectos de los fármacos , Núcleo Caudado/efectos de los fármacos , Núcleo Caudado/metabolismo , Núcleo Caudado/patología , Cromatografía Líquida de Alta Presión , Dopamina/análisis , Dopamina/metabolismo , Inhibidores de Captación de Dopamina/administración & dosificación , Inhibidores de Captación de Dopamina/toxicidad , Relación Dosis-Respuesta a Droga , Inmunoquímica , Bombas de Infusión Implantables , Inyecciones Subcutáneas , Masculino , Mesencéfalo/efectos de los fármacos , Mesencéfalo/metabolismo , Mesencéfalo/patología , Metanfetamina/administración & dosificación , Fosforilación/efectos de los fármacos , Corteza Prefrontal/efectos de los fármacos , Corteza Prefrontal/metabolismo , Corteza Prefrontal/patología , Ratas , Ratas Sprague-Dawley , Receptores AMPA/metabolismo , Selegilina/administración & dosificación , Sustancia Negra/efectos de los fármacos , Sustancia Negra/metabolismo , Sustancia Negra/patología , Sinapsis/fisiología , Factores de Tiempo , Tirosina 3-Monooxigenasa/análisis , Tirosina 3-Monooxigenasa/metabolismoRESUMEN
We have recently shown in rats that cocaine-induced behavioral sensitization can be reversed by a 5-day treatment with ondansetron given 3.5 h after daily pergolide injections. In this study we further investigated the molecular/neurochemical alterations underlying cocaine sensitization and pergolide/ondansetron-mediated reversal. Results revealed that glutamic acid decarboxylase (GAD(65)/GAD(67)) is higher abundant in the nucleus accumbens (NAc) than that in the caudate and medial prefrontal cortex (mPFC), while GABA(A) receptor alpha2 subunit level in the NAc shell is less abundant than that in the NAc core, mPFC and caudate. Cocaine sensitization led to (1) a decrease in GAD(67) expression, an increase in total protein kinase C (PKC) zeta subtype and phosphorylated PKC zeta/lambda levels in the NAc core; (2) a decrease in GAD(67) and GABA(A) receptor alpha2 subunit expression, and an increase in phosphorylated PKC zeta/lambda levels in the NAc shell; (3) an increase in GAD(67) expression in the caudate. Importantly, pergolide/ondansetron treatment reversed these alterations. These results suggest that reversal of cocaine-induced behavioral sensitization is associated with reversal of region-specific changes in GABA function and PKC activity in the striatum.
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Conducta Animal/efectos de los fármacos , Cocaína/antagonistas & inhibidores , Glutamato Descarboxilasa/metabolismo , Isoenzimas/metabolismo , Proteína Quinasa C/metabolismo , Receptores de GABA-A/biosíntesis , Animales , Núcleo Caudado/metabolismo , Masculino , Núcleo Accumbens/enzimología , Ondansetrón/farmacología , Pergolida/farmacología , Corteza Prefrontal/enzimología , Ratas , Ratas Sprague-Dawley , Conducta Estereotipada/efectos de los fármacosRESUMEN
The present study investigated whether GABA(A) receptor alpha2 subunit and GAD(67) are involved in chronic high dose methamphetamine (METH)-induced sensitization and neurotoxicity. The METH sensitization was established in rats by 7-day pump infusion plus daily injection (25mg/kg/day) and a subsequent 28-day withdrawal period. Behavioral sensitization was assessed by behavioral ratings after challenge with METH (0.5mg/kg). The neurotoxicity was evaluated by the expression of glial fibrillary acidic protein (GFAP). Western blot assay showed that METH sensitization decreases GABA(A) alpha2 subunit and GAD(67) protein levels in the nucleus accumbens (NAc) core and shell, and conversely, these proteins were increased in the caudate. An upregulation of GFAP expression was observed in the caudate, but not in the NAc core and shell. These data suggest that inhibition of GABA transmission in the NAc is related to METH behavioral sensitization, whereas activation of GABA transmission in the caudate is associated with METH-induced neurotoxicity.
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Encéfalo/metabolismo , Glutamato Descarboxilasa/metabolismo , Isoenzimas/metabolismo , Metanfetamina/farmacología , Receptores de GABA-A/metabolismo , Adaptación Fisiológica/efectos de los fármacos , Adaptación Fisiológica/fisiología , Animales , Encéfalo/efectos de los fármacos , Expresión Génica/efectos de los fármacos , Expresión Génica/fisiología , Masculino , Ratas , Ratas Sprague-DawleyRESUMEN
Male Sprague-Dawley rats were given two separate sensitizing regimens of cocaine (7 days on, 7 days off, 7 days on at 40 mg/kg/day, s.c.) or saline injections. Half of the animals also received a drug with 5-hydroxytryptamine-2 (5-HT2) receptor antagonist properties (clozapine, 3 mg/kg; mianserin 6 mg/kg; ketanserin 1 mg/kg, all s.c.) or saline during the second cocaine dosing regimen in the acute withdrawal period, 3.5 h after each cocaine injection. On day 10 of withdrawal animals were challenged with cocaine (7.5 mg/kg, i.p.) and assessed by a behavioral rating scale and locomotor activity monitoring. The 5-HT2 receptor antagonists, but not saline, reversed behavioral sensitization and had little effect on behavior in the control animals. 5-HT2 receptor antagonists, therefore, may be a useful treatment for cocaine addicts that have undergone previous sensitization periods. The pharmacological profile of these antagonists suggests that the 5-HT2A receptor subtype may mediate this effect.