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1.
Opt Lett ; 49(9): 2353-2356, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38691717

RESUMO

Clock recovery (CR) algorithms that support higher baud rates and advanced modulation formats are crucial for short-distance optical interconnections, and it is desirable to push CR to operate at baud rate with minimal computing resources and power. In this Letter, we proposed a hardware-efficient and multiplication operation-free baud-rate timing error detector (TED) as a solution to meet these demands. Our approach involves employing both the absolute value of samples and the nonlinear sign operation to emphasize the clock tone, which is deteriorated by severe bandwidth limitation in Nyquist and faster than Nyquist (FTN) systems. Through experimental investigations based on a transceiver system with a 3 dB bandwidth of 30 GHz, the proposed baud-rate TED exhibits excellent performance. The proposed scheme successfully achieves clock synchronization of the received signals with the transmitted signals, including 50 GBaud PAM4/8, 80 GBaud PAM4, and up to 120 GBaud PAM4 FTN signals. To the best of our knowledge, the CR based on the proposed baud-rate TED is the most optimal solution for ultrahigh-speed short-reach IM/DD transmission, comprehensively considering the timing jitter, bit error rate (BER), and implementation complexity.

2.
Biogerontology ; 24(4): 581-592, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37052773

RESUMO

There is growing evidence that extracellular vesicles (EVs) play a functional role in tissue repair and anti-aging by transferring the contents of donor cells to recipient cells. We hypothesized that Dauer (C. elegans), known as "ageless" nematodes, can also secrete extracellular vesicles and influence the lifespan of C. elegans. Here, we isolated EVs of dauer larvae (dauer EVs). Dauer EVs were characterized using transmission electron microscopy, nanoparticle tracking analysis (NTA), and Western blot analysis. Wild-type C. elegans were fed in the presence or absence of dauer EVs and tested for a range of phenotypes, including longevity, mobility and reproductive capacity. Results showed that dauer EVs increased the average lifespan of nematodes by 15.74%, improved mobility, slowed age-related pigmentation as well as body length, and reduced the accumulation of reactive oxygen species and lipids, while not impairing nematode reproductive capacity. These findings suggest that dauer EVs can extend the lifespan of C. elegans as well as the healthy lifespan by reducing ROS accumulation, with potential anti-aging capacity.


Assuntos
Proteínas de Caenorhabditis elegans , Vesículas Extracelulares , Animais , Caenorhabditis elegans/genética , Larva , Envelhecimento , Proteínas de Caenorhabditis elegans/genética , Longevidade/genética
3.
J Nucl Cardiol ; 30(3): 970-985, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-35982208

RESUMO

BACKGROUND: Low-dose (LD) myocardial perfusion (MP) SPECT suffers from high noise level, leading to compromised diagnostic accuracy. Here we investigated the denoising performance for MP-SPECT using a conditional generative adversarial network (cGAN) in projection-domain (cGAN-prj) and reconstruction-domain (cGAN-recon). METHODS: Sixty-four noisy SPECT projections were simulated for a population of 100 XCAT phantoms with different anatomical variations and 99mTc-sestamibi distributions. Series of LD projections were obtained by scaling the full dose (FD) count rate to be 1/20 to 1/2 of the original. Twenty patients with 99mTc-sestamibi stress SPECT/CT scans were retrospectively analyzed. For each patient, LD SPECT images (7/10 to 1/10 of FD) were generated from the FD list mode data. All projections were reconstructed by the quantitative OS-EM method. A 3D cGAN was implemented to predict FD images from their corresponding LD images in the projection- and reconstruction-domain. The denoised projections were reconstructed for analysis in various quantitative indices along with cGAN-recon, Gaussian, and Butterworth-filtered images. RESULTS: cGAN denoising improves image quality as compared to LD and conventional post-reconstruction filtering. cGAN-prj can further reduce the dose level as compared to cGAN-recon without compromising the image quality. CONCLUSIONS: Denoising based on cGAN-prj is superior to cGAN-recon for MP-SPECT.


Assuntos
Aprendizado Profundo , Humanos , Estudos Retrospectivos , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Tomografia Computadorizada com Tomografia Computadorizada de Emissão de Fóton Único , Tecnécio Tc 99m Sestamibi , Perfusão , Processamento de Imagem Assistida por Computador/métodos , Imagens de Fantasmas
4.
Psychosom Med ; 84(6): 685-694, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35472074

RESUMO

OBJECTIVE: Cortisol is associated with cognition in both healthy individuals and patients with neuropsychiatric disorders. Regarding the effects of cortisol on the dopamine system and the association between dopamine transporter (DAT) and cognition, DAT might be a central target linking cortisol and cognition. This study explored the role of striatal DAT in the cortisol-cognition relationship. METHODS: We recruited 33 patients with carbon monoxide poisoning and 33 age- and sex-matched healthy controls. All participants underwent cognitive assessments of attention, memory, and executive function. Single-photon emission computed tomography with 99mTc-TRODAT was used to determine striatal DAT availability. Plasma cortisol, tumor necrosis factor α, and interleukin-10 levels were measured using enzyme-linked immunosorbent assays. RESULTS: Compared with healthy controls, patients with carbon monoxide poisoning had lower cognitive performance, bilateral striatal DAT availability, and plasma tumor necrosis factor-α levels and higher cortisol and interleukin-10 levels. In all participants, plasma cortisol level and bilateral striatal DAT availability were negatively and positively related to cognition, respectively, including memory and executive function with ß from -0.361 (95% confidence interval [CI] = -0.633 to -0.090) to 0.588 (95% CI = 0.319 to 0.858). Moreover, bilateral striatal DAT mediated the cortisol-cognition relationship with indirect effects from -0.067 (95% CI = -0.179 to -0.001) to -0.135 (95% CI = -0.295 to -0.024). The cytokine levels did not influence the mediation effects. CONCLUSIONS: This is the first study to demonstrate that striatal DAT mediates the cortisol-cognition relationship. Future studies are needed to comprehensively evaluate the role of the dopamine system in cortisol-cognition associations and treatment implications.


Assuntos
Intoxicação por Monóxido de Carbono , Proteínas da Membrana Plasmática de Transporte de Dopamina , Cognição , Dopamina , Humanos , Hidrocortisona , Interleucina-10 , Tomografia Computadorizada de Emissão de Fóton Único/métodos
5.
Artigo em Inglês | MEDLINE | ID: mdl-35696264

RESUMO

A novel bacterium, designated NAS39T, was isolated from the interfacial sediment of Taihu Lake in PR China and its taxonomic position was investigated by using a polyphasic approach. Cells of the isolate were Gram-stain-negative, aerobic, non-motile, catalase-positive, yellow and rod-shaped. Phylogenetic analyses based on 16S rRNA gene sequences supported that strain NAS39T formed a cluster within the genus Flavobacterium, and was most closely related to Flavobacterium laiguense LB2P30T (98.4 %), followed by Flavobacterium tiangeerense 0563T (97.4 %). The average nucleotide identity values between strain NAS39T and F. laiguense LB2P30T and F. tiangeerense 0563T were 82.5 and 75.3 %, respectively. The digital DNA-DNA hybridization values between strain NAS39T and F. laiguense LB2P30T and F. tiangeerense 0563T were 40.9 and 18.6 %, respectively. The genomic DNA G+C content was 34.1 mol%. The major respiratory quinone was menaquinone-6. The dominant cellular fatty acids were iso-C15 : 0 and summed feature 3 comprising C16 : 1 ω7c/C16 : 1 ω6c. The polar lipids comprised phosphatidyl ethanolamine, two amino lipids, three amino phospholipids and two unidentified lipids. Based on the phenotypic, chemotaxonomic, genotypic and phylogenetic characteristics, strain NAS39T (=MCCC 1K06094T=KACC 22328T) represents a novel species of the genus Flavobacterium, for which the name Flavobacterium taihuense sp. nov. is proposed.


Assuntos
Flavobacterium , Lagos , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Lagos/análise , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análise
6.
Int J Mol Sci ; 22(16)2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34445342

RESUMO

Epigenetic regulation by histone deacetylase (HDAC) is associated with synaptic plasticity and memory formation, and its aberrant expression has been linked to cognitive disorders, including Alzheimer's disease (AD). This study aimed to investigate the role of class IIa HDAC expression in AD and monitor it in vivo using a novel radiotracer, 6-(tri-fluoroacetamido)-1-hexanoicanilide ([18F]TFAHA). A human neural cell culture model with familial AD (FAD) mutations was established and used for in vitro assays. Positron emission tomography (PET) imaging with [18F]TFAHA was performed in a 3xTg AD mouse model for in vivo evaluation. The results showed a significant increase in HDAC4 expression in response to amyloid-ß (Aß) deposition in the cell model. Moreover, treatment with an HDAC4 selective inhibitor significantly upregulated the expression of neuronal memory-/synaptic plasticity-related genes. In [18F]TFAHA-PET imaging, whole brain or regional uptake was significantly higher in 3xTg AD mice compared with WT mice at 8 and 11 months of age. Our study demonstrated a correlation between class IIa HDACs and Aßs, the therapeutic benefit of a selective inhibitor, and the potential of using [18F]TFAHA as an epigenetic radiotracer for AD, which might facilitate the development of AD-related neuroimaging approaches and therapies.


Assuntos
Doença de Alzheimer/diagnóstico por imagem , Inibidores de Histona Desacetilases/farmacocinética , Histona Desacetilases/metabolismo , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Anilidas/química , Anilidas/farmacocinética , Animais , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Modelos Animais de Doenças , Epigênese Genética/efeitos dos fármacos , Epigênese Genética/fisiologia , Radioisótopos de Flúor/química , Radioisótopos de Flúor/farmacocinética , Fluoracetatos/química , Fluoracetatos/farmacocinética , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Inibidores de Histona Desacetilases/química , Histona Desacetilases/classificação , Histona Desacetilases/genética , Humanos , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neuroimagem/métodos , Tomografia por Emissão de Pósitrons/métodos , Células Tumorais Cultivadas
7.
Int J Mol Sci ; 22(9)2021 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-34066508

RESUMO

Ovarian cancer (OC) metastases frequently occur through peritoneal dissemination, and they contribute to difficulties in treatment. While photodynamic therapy (PDT) has the potential to treat OC, its use is often limited by tissue penetration depth and tumor selectivity. Herein, we combined Cerenkov radiation (CR) emitted by 18F-FDG accumulated in tumors as an internal light source and several photosensitizer (PS) candidates with matched absorption bands, including Verteporfin (VP), Chlorin e6 (Ce6) and 5'-Aminolevulinic acid (5'-ALA), to evaluate the anti-tumor efficacy. The in vitro effect of CR-induced PDT (CR-PDT) was evaluated using a cell viability assay, and the efficiency of PS was assessed by measuring the singlet oxygen production. An intraperitoneal ES2 OC mouse model was used for in vivo evaluation of CR-PDT. Positron emission tomography (PET) imaging and bioluminescence-based imaging were performed to monitor the biologic uptake of 18F-FDG and the therapeutic effect. The in vitro studies demonstrated Ce6 and VP to be more effective PSs for CR-PDT. Moreover, VP was more efficient in the generation of singlet oxygen and continued for a long time when exposed to fluoro-18 (18F). Combining CR emitted by 18F-FDG and VP treatment not only significantly suppressed tumor growth, but also prolonged median survival times compared to either monotherapy.


Assuntos
Fluordesoxiglucose F18/uso terapêutico , Neoplasias Ovarianas/terapia , Fotoquimioterapia , Radiação , Ensaios Antitumorais Modelo de Xenoenxerto , Animais , Linhagem Celular Tumoral , Feminino , Injeções Intraperitoneais , Camundongos Endogâmicos BALB C
8.
Int J Syst Evol Microbiol ; 70(9): 4986-4992, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32762805

RESUMO

A novel strain, designated NS18T, was isolated from sediment sampled at Taihu Lake, PR China. Cells of the isolate were spherical, aerobic, non-motile, Gram-stain-positive and non-endospore-forming. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain NS18T clustered in a clade of the genus Agrococcus. Its closest phylogenetic neighbour was Agrococcus lahaulensis DSM 17612T with 98.2 % 16S rRNA gene sequence similarity. The complete genome of NS18T was 2 736 037 bp and its genomic DNA G+C content was 72.8 mol%. The average nucleotide identity and digital DNA-DNA hybridization values between strain NS18T and A. lahaulensis DSM 17612T based on their whole genomes were 85.1 and 28.7 %, respectively. The major fatty acids were anteiso-C17 : 0 and anteiso-C15 : 0. The predominant menaquinones were MK11 and MK12. The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol and two unidentified lipids. The components of the peptidoglycan were Ala, Gly, Asp, Thr and DAB. The whole-cell sugars contained rhamnose, ribose, xylose and glucose. According to the results of phenotypic, chemotaxonomic and phylogenetic analyses, strain NS18T (=NBRC 113859T=MCCC 1K03759T) represents a novel species, for which the name Agrococcus sediminis sp. nov is proposed.


Assuntos
Actinobacteria/classificação , Sedimentos Geológicos/microbiologia , Lagos/microbiologia , Filogenia , Actinobacteria/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Peptidoglicano/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/química
9.
Int J Syst Evol Microbiol ; 70(11): 5950-5957, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33048042

RESUMO

A taxonomic identification using a polyphasic approach was performed on strain NBS58-1T, which was isolated from the interfacial sediment of Taihu Lake in China. Strain NBS58-1T was Gram-stain-negative, aerobic, non-spore-forming and catalase-positive. Phylogenetic analyses based on 16S rRNA gene and three housekeeping genes (rpoB, gyrB and dnaK) sequences supported the position that strain NBS58-1T should be classified within the genus Rufibacter. The 16S rRNA gene sequence of strain NBS58-1T possessed the highest similarity to Rufibacter sediminis H-1T (96.60 %), followed by Rufibacter glacialis MDT1-10-3T (96.17 %). And the ANI value between strain NBS58-1T and R. glacialis MDT1-10-3T was 79.3 %. The respiratory quinone was menaquinone 7 (MK-7). The major cellular fatty acids comprised iso-C15 : 0 and summed feature 3. Phosphatidylethanolamine, two unidentified phospholipids and four unidentified lipids were the main polar lipids. The genomic DNA G+C content was 51.3 mol%. Based on phenotypic features and phylogenetic position, a novel species with the name Rufibacter hautae sp. nov. is proposed. The type strain is NBS58-1T=(KACC 21309T=MCCC 1K04037T). We also proposed Rufibacter quisquiliarum as a latter heterotypic synonym of Rufibacter ruber.


Assuntos
Bacteroidetes/classificação , Sedimentos Geológicos/microbiologia , Lagos/microbiologia , Filogenia , Técnicas de Tipagem Bacteriana , Bacteroidetes/isolamento & purificação , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Fosfolipídeos/química , Pigmentação , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
10.
J Nucl Cardiol ; 27(3): 819-828, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-30324328

RESUMO

BACKGROUND: Short imaging protocol to quantify myocardial blood flow (MBF) and myocardial flow reserve (MFR) may enhance the clinical application of 13N-ammonia cardiac PET. We assessed the flow quantitation of 13N-ammonia PET implementing simple retention model and two-compartment model. METHODS: Fourteen healthy volunteers (HVT) and twenty-three clinical patients received 13N-ammonia PET/CT. The simple retention model used the first 7-minute image to quantify MBF. Global and regional MBF and MFR of the two models were compared. RESULTS: Global and regional MBF and MFR of these two models were highly correlated with mildly inferior correlation in RCA territory (global R2: rest MBF = 0.79, stress MBF = 0.65, MFR = 0.77; regional R2: rest MBF ≥ 0.72, stress MBF ≥ 0.52, MFR ≥ 0.68). There were significant differences for MFR (4.04 ± 0.72, 3.66 ± 0.48, p = .02) and rest MBF (0.69 ± 0.12, 0.78 ± 0.12, p = .02) between the two models in the HVT group. CONCLUSIONS: 13N-ammonia global and regional MBF and MFR from the simple retention model demonstrate strong correlations with that from the two-compartment model. Significant differences of MFR and rest MBF are noted in the HVT group, with a proposed normal reference value for the 13N-ammonia short simple retention protocol.


Assuntos
Doença da Artéria Coronariana/diagnóstico por imagem , Circulação Coronária , Coração/diagnóstico por imagem , Coração/fisiopatologia , Radioisótopos de Nitrogênio , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Amônia , Artérias/diagnóstico por imagem , Feminino , Reserva Fracionada de Fluxo Miocárdico , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Imagem de Perfusão do Miocárdio/métodos , Miocárdio , Compostos Radiofarmacêuticos
11.
Alcohol Clin Exp Res ; 42(2): 329-337, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29205407

RESUMO

BACKGROUND: Ethanol (EtOH) intoxication inhibits glucose transport and decreases overall brain glucose metabolism; however, humans with long-term EtOH consumption were found to have a significant increase in [1-11 C]-acetate uptake in the brain. The relationship between the cause and effect of [1-11 C]-acetate kinetics and acute/chronic EtOH intoxication, however, is still unclear. METHODS: [1-11 C]-acetate positron emission tomography (PET) with dynamic measurement of K1 and k2 rate constants was used to investigate the changes in acetate metabolism in different brain regions of rats with acute or chronic EtOH intoxication. RESULTS: PET imaging demonstrated decreased [1-11 C]-acetate uptake in rat brain with acute EtOH intoxication, but this increased with chronic EtOH intoxication. Tracer uptake rate constant K1 and clearance rate constant k2 were decreased in acutely intoxicated rats. No significant change was noted in K1 and k2 in chronic EtOH intoxication, although 6 of 7 brain regions showed slightly higher k2 than baseline. These results indicate that acute EtOH intoxication accelerated acetate transport and metabolism in the rat brain, whereas chronic EtOH intoxication status showed no significant effect. CONCLUSIONS: In vivo PET study confirmed the modulatory role of EtOH, administered acutely or chronically, in [1-11 C]-acetate kinetics and metabolism in the rat brain. Acute EtOH intoxication may inhibit the transport and metabolism of acetate in the brain, whereas chronic EtOH exposure may lead to the adaptation of the rat brain to EtOH in acetate utilization. [1-11 C]-acetate PET imaging is a feasible approach to study the effect of EtOH on acetate metabolism in rat brain.


Assuntos
Acetatos/metabolismo , Intoxicação Alcoólica/metabolismo , Alcoolismo/metabolismo , Encéfalo/efeitos dos fármacos , Depressores do Sistema Nervoso Central/farmacologia , Etanol/farmacologia , Intoxicação Alcoólica/diagnóstico por imagem , Alcoolismo/diagnóstico por imagem , Animais , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Radioisótopos de Carbono , Glucose/metabolismo , Masculino , Tomografia por Emissão de Pósitrons , Ratos
12.
Eur J Nucl Med Mol Imaging ; 44(1): 117-128, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27585576

RESUMO

OBJECTIVES: The aim of this study was to evaluate the accuracy of myocardial blood flow (MBF) quantitation of 99mTc-Sestamibi (MIBI) single photon emission computed tomography (SPECT) compared with 13N-Ammonia (NH3) position emission tomography (PET) on the same cohorts. BACKGROUND: Recent advances of SPECT technologies have been applied to develop MBF quantitation as a promising tool to diagnose coronary artery disease (CAD) for areas where PET MBF quantitation is not available. However, whether the SPECT approach can achieve the same level of accuracy as the PET approach for clinical use still needs further investigations. METHODS: Twelve healthy volunteers (HVT) and 16 clinical patients with CAD received both MIBI SPECT and NH3 PET flow scans. Dynamic SPECT images acquired with high temporary resolution were fully corrected for physical factors and processed to quantify K1 using the standard compartmental modeling. Human MIBI tracer extraction fraction (EF) was determined by comparing MIBI K1 and NH3 flow on the HVT group and then used to convert flow values from K1 for all subjects. MIBI and NH3 flow values were systematically compared to validate the SPECT approach. RESULTS: The human MIBI EF was determined as [1.0-0.816*exp(-0.267/MBF)]. Global and regional MBF and myocardial flow reserve (MFR) of MIBI SPECT and NH3 PET were highly correlated for all subjects (global R2: MBF = 0.92, MFR = 0.78; regional R2: MBF ≥ 0.88, MFR ≥ 0.71). No significant differences for rest flow, stress flow, and MFR between these two approaches were observed (All p ≥ 0.088). Bland-Altman plots overall revealed small bias between MIBI SPECT and NH3 PET (global: ΔMBF = -0.03Lml/min/g, ΔMFR = 0.07; regional: ΔMBF = -0.07 - 0.06 , ΔMFR = -0.02 - 0.22). CONCLUSIONS: Quantitation with SPECT technologies can be accurate to measure myocardial blood flow as PET quantitation while comprehensive imaging factors of SPECT to derive the variability between these two approaches were fully addressed and corrected.


Assuntos
Amônia , Doença da Artéria Coronariana/fisiopatologia , Circulação Coronária , Tomografia por Emissão de Pósitrons/métodos , Tecnécio Tc 99m Sestamibi , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Adulto , Idoso , Velocidade do Fluxo Sanguíneo , Doença da Artéria Coronariana/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Imagem de Perfusão do Miocárdio/métodos , Radioisótopos de Nitrogênio , Compostos Radiofarmacêuticos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
13.
Hum Brain Mapp ; 37(3): 1080-90, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26821769

RESUMO

BACKGROUND: Low-dose ketamine has been found to have robust and rapid antidepressant effects. A hypoactive prefrontal cortex (PFC) and a hyperactive amygdala have been suggested to be associated with treatment-resistant depression (TRD). However, it is unclear whether the rapid antidepressant mechanisms of ketamine on TRD involve changes in glutamatergic neurotransmission in the PFC and the amygdala. METHODS: A group of 48 TRD patients were recruited and equally randomized into three groups (A: 0.5 kg/mg-ketamine; B: 0.2 kg/mg-ketamine; and C: normal saline [NS]). Standardized uptake values (SUV) of glucose metabolism measured by (18) F-FDG positron-emission-tomography before and immediately after a 40-min ketamine or NS infusion were used for subsequent region-of-interest (ROI) analyses (a priori regions: PFC and amygdala) and whole-brain voxel-wise analyses and were correlated with antidepressant responses, as defined by the Hamilton depression rating scale score. The (18) F-FDG signals were used as a proxy measure of glutamate neurotransmission. RESULTS: The ROI analysis indicated that Group A and Group B, but not Group C, had increases in the SUV of the PFC (group-by-time interaction: F = 7.373, P = 0.002), whereas decreases in the SUV of the amygdala were observed in all three groups (main effect of time, P < 0.001). The voxel-wise analysis further confirmed a significant group effect on the PFC (corrected for family-wise errors, P < 0.05; post hoc analysis: Group A

Assuntos
Tonsila do Cerebelo/efeitos dos fármacos , Antidepressivos/administração & dosagem , Transtorno Depressivo Resistente a Tratamento/tratamento farmacológico , Ketamina/administração & dosagem , Córtex Pré-Frontal/efeitos dos fármacos , Adulto , Tonsila do Cerebelo/diagnóstico por imagem , Antidepressivos/efeitos adversos , Transtorno Depressivo Maior/diagnóstico por imagem , Transtorno Depressivo Maior/tratamento farmacológico , Transtorno Depressivo Resistente a Tratamento/diagnóstico por imagem , Relação Dose-Resposta a Droga , Método Duplo-Cego , Antagonistas de Aminoácidos Excitatórios/administração & dosagem , Antagonistas de Aminoácidos Excitatórios/efeitos adversos , Feminino , Fluordesoxiglucose F18 , Ácido Glutâmico , Humanos , Ketamina/efeitos adversos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons , Córtex Pré-Frontal/diagnóstico por imagem , Escalas de Graduação Psiquiátrica , Compostos Radiofarmacêuticos
14.
J Nucl Cardiol ; 23(5): 1072-1079, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-25933679

RESUMO

BACKGROUND: Previously, we proposed interpolated averaged CT (IACT) for improved attenuation correction (AC) in thoracic PET/CT. This study aims to evaluate its feasibility and effectiveness on cardiac PET/CT. METHODS: We simulated (18)F-FDG distribution using the XCAT phantom with normal and abnormal cardiac uptake. Average activity and attenuation maps represented static PET and respiration average CT (ACT), respectively, while the attenuation maps of end-inspiration/expiration represented 2 helical CTs (HCT). IACT was obtained by averaging the 2 extreme phases and the interpolated phases generated between them. Later, we recruited 4 patients who were scanned 1 hr post 315-428 MBq (18)F-FDG injection. Simulated and clinical PET sinograms were reconstructed with AC using (1) HCT, (2) IACT, and (3) ACT. Polar plots and the 17-segment plots were analyzed. Two regions-of-interest were drawn on lesion and background area to obtain the intensity ratio (IR). RESULTS: Polar plots of PETIACT-AC were more similar to PETACT-AC in both simulation and clinical data. Artifacts were observed in various segments in PETHCT-AC. IR differences of HCT as compared to the phantom were up to ~20%. CONCLUSIONS: IACT-AC reduced respiratory artifacts and improved PET/CT matching similarly to ACT-AC. It is a promising low-dose alternate of ACT for cardiac PET/CT.


Assuntos
Artefatos , Doença da Artéria Coronariana/diagnóstico por imagem , Aumento da Imagem/métodos , Imageamento Tridimensional/métodos , Armazenamento e Recuperação da Informação/métodos , Imagem de Perfusão do Miocárdio/métodos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Estudos de Viabilidade , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Masculino , Pessoa de Meia-Idade , Análise Numérica Assistida por Computador , Imagens de Fantasmas , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/instrumentação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
15.
Am J Primatol ; 76(7): 609-17, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24375453

RESUMO

Group-level male-male co-operation, which has been documented in several primate and non-primate societies, may be mutualistically advantageous to the participants when confronted with threats such as takeovers and cuckoldry by external males. Co-operation among members of distinct social units-while universal among humans-is extremely rare in non-human primates. We present the first observations of collective action or co-operation among males of different one-male units (OMU) in a multi-level society of Rhinopithecus roxellana. A total of 59 instances of male co-operation were recorded. Male co-operation included coordinated chasing, joint vigilance, and patrolling behavior directed at lone adult males trying to enter an OMU. Male co-operation was significantly more frequent during the mating season when the risk of incursions and extra-group paternity was higher. Paternity of infants born in the subsequent birth season and kin relationships among resident males were identified using microsatellite genotype. All infants were sired by OMU males, which we interpret as possible evidence for their success at thwarting mating attempts by satellite males. OMU males were principally unrelated suggesting that male co-operation is best understood in terms of the mutual direct benefits individuals obtain through collective action. Our findings lend support to the bachelor threat hypothesis in which the cooperative behavior of several individuals is more effective than the lone action of a single individual in providing mate defense. Our research has implications for understanding male bonding, higher-level collective action, and the evolution of social co-operation in human societies.


Assuntos
Colobinae/fisiologia , Genótipo , Repetições de Microssatélites , Territorialidade , Animais , China , Colobinae/genética , Masculino , Estações do Ano , Comportamento Sexual Animal , Comportamento Social
16.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 45(4): 712-6, 2014 Jul.
Artigo em Zh | MEDLINE | ID: mdl-25286703

RESUMO

OBJECTIVE: To determine the feasibility and clinical efficacy of ultrasound-guided facet joint injection and nerve block in lumbar facet joint for the treatment of facet-joint related low back pain. METHODS: 20 patients with facet-joint pain were randomized into two groups received block blindly (B group) or guided by ultrasound (US group) respectively. The location of needle tip was confirmed by CT in both groups, and the accuracy was computed afterwards. VAS score, puncture time and one-time puncture success rate (%) were recorded. VAS scores and pain remission rates in both groups were recorded at 30 min, 1 d, 2 d, 6 weeks after the block. RESULTS: The VAS scores were 3.3 +/- 0.4 in US group and 1.2 +/- 0.3 in B group (P < 0.05). The puncture time was (206 +/- 27) s in US group while (397 +/- 31) s in B group (P < 0.05). There were 37 facet joint blocks guided by ultrasound, in which 32 were correctly targeted with the first puncture. The success rate is 86.5%. There were 35 facet joint blocks blindly, in which 11 were correctly targeted with the first puncture. The success rate is 31.4%. The difference of one-time puncture success rate between the two groups was significant (P < 0.05). Differences of VAS and pain remission rate at half an hour after facet joint injection between B group and US group were significant (P < 0.05). There were 8, 9, 9, and 9 patients in US group obtaining a reduction in VAS scores > or = 3 at 30 min, 1 d, 2 d and 6 weeks after the procedure respectively, while the numbers of such patients were 5, 6, 5, 5 in B group (P > 0.05). After 6 weeks of follow-up, the overall remission rates were (72.3 +/- 14.0)% in US group, and (56.7 +/- 11.0)% in B group, there was no significant difference between the two groups (P > 0.05). CONCLUSION: The ultrasound-guided lumbar facet joint injection technique had a high feasibility and accuracy, and had better clinical efficacy than block blindly.


Assuntos
Dor Lombar/terapia , Bloqueio Nervoso , Terapia por Ultrassom , Articulação Zigapofisária/patologia , Artralgia/terapia , Humanos , Injeções , Vértebras Lombares/patologia
17.
J Psychopharmacol ; 38(6): 515-525, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38853592

RESUMO

BACKGROUND: A better understanding of the mechanisms underlying cognitive impairment in schizophrenia is imperative, as it causes poor functional outcomes and a lack of effective treatments. AIMS: This study aimed to investigate the relationships of two proposed main pathophysiology of schizophrenia, altered prefrontal-striatal connectivity and the dopamine system, with cognitive impairment and their interactions. METHODS: Thirty-three patients with schizophrenia and 27 healthy controls (HCs) who are right-handed and matched for age and sex were recruited. We evaluated their cognition, functional connectivity (FC) between the dorsolateral prefrontal cortex (DLPFC)/middle frontal gyrus (MiFG) and striatum, and the availability of striatal dopamine transporter (DAT) using a cognitive battery investigating attention, memory, and executive function, resting-state functional magnetic resonance imaging with group independent component analysis and single-photon emission computed tomography with 99mTc-TRODAT. RESULTS: Patients with schizophrenia exhibited poorer cognitive performance, reduced FC between DLPFC/MiFG and the caudate nucleus (CN) or putamen, decreased DAT availability in the left CN, and decreased right-left DAT asymmetry in the CN compared to HCs. In patients with schizophrenia, altered imaging markers are associated with cognitive impairments, especially the relationship between DLPFC/MiFG-putamen FC and attention and between DAT asymmetry in the CN and executive function. CONCLUSIONS: This study is the first to demonstrate how prefrontal-striatal hypoconnectivity and altered striatal DAT markers are associated with different domains of cognitive impairment in schizophrenia. More research is needed to evaluate their complex relationships and potential therapeutic implications.


Assuntos
Disfunção Cognitiva , Corpo Estriado , Proteínas da Membrana Plasmática de Transporte de Dopamina , Imageamento por Ressonância Magnética , Esquizofrenia , Tomografia Computadorizada de Emissão de Fóton Único , Humanos , Masculino , Feminino , Esquizofrenia/fisiopatologia , Esquizofrenia/metabolismo , Esquizofrenia/diagnóstico por imagem , Adulto , Disfunção Cognitiva/fisiopatologia , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/diagnóstico por imagem , Corpo Estriado/metabolismo , Corpo Estriado/diagnóstico por imagem , Corpo Estriado/fisiopatologia , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Dopamina/metabolismo , Córtex Pré-Frontal/metabolismo , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Pré-Frontal/fisiopatologia , Córtex Pré-Frontal Dorsolateral/metabolismo , Estudos de Casos e Controles , Pessoa de Meia-Idade , Função Executiva/fisiologia , Testes Neuropsicológicos , Adulto Jovem
18.
IEEE Trans Pattern Anal Mach Intell ; 46(8): 5712-5724, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38421845

RESUMO

Natural Language Generation (NLG) accepts input data in the form of images, videos, or text and generates corresponding natural language text as output. Existing NLG methods mainly adopt a supervised approach and rely heavily on coupled data-to-text pairs. However, for many targeted scenarios and for non-English languages, sufficient quantities of labeled data are often not available. As a result, it is necessary to collect and label data-text pairs for training, which is both costly and time-consuming. To relax the dependency on labeled data of downstream tasks, we propose an intuitive and effective zero-shot learning framework, ZeroNLG, which can deal with multiple NLG tasks, including image-to-text (image captioning), video-to-text (video captioning), and text-to-text (neural machine translation), across English, Chinese, German, and French within a unified framework. ZeroNLG does not require any labeled downstream pairs for training. During training, ZeroNLG (i) projects different domains (across modalities and languages) to corresponding coordinates in a shared common latent space; (ii) bridges different domains by aligning their corresponding coordinates in this space; and (iii) builds an unsupervised multilingual auto-encoder to learn to generate text by reconstructing the input text given its coordinate in shared latent space. Consequently, during inference, based on the data-to-text pipeline, ZeroNLG can generate target sentences across different languages given the coordinate of input data in the common space. Within this unified framework, given visual (imaging or video) data as input, ZeroNLG can perform zero-shot visual captioning; given textual sentences as input, ZeroNLG can perform zero-shot machine translation. We present the results of extensive experiments on twelve NLG tasks, showing that, without using any labeled downstream pairs for training, ZeroNLG generates high-quality and "believable" outputs and significantly outperforms existing zero-shot methods.

19.
Zhonghua Yi Xue Za Zhi ; 93(44): 3532-6, 2013 Nov 26.
Artigo em Zh | MEDLINE | ID: mdl-24521897

RESUMO

OBJECTIVE: To explore whether the signal pathways of phosphoinositide 3-kinase (PI3K) and Notch can realize coordinated regulation on the activation and proliferation of CD4(+)T lymphocytes. METHODS: Male BALB/c mice were randomly divided into control and asthma groups. Then the murine model of asthma was established by the method of ovalbumin (OVA) challenge. The CD4(+)T lymphocytes were isolated by magnetic activated cell sorter (MACS) and then activated with phytohaemagglutinin (PHA) (10 µg/ml) and IL-2 (1000 U/ml) for 6 h. Those cells were then divided into Group A: without any treatment; Group B: treatment with PI3K inhibitor (LY294002); Group C: treatment with Notch inhibitor (gamma-secretase inhibitor, DAPT); Group D: treatment with PI3K inhibitor and Notch inhibitor. The protein and transcription levels of Cyclin A, Cyclin D1 and P27(kip1) of CD4(+)T lymphocytes were assessed by flow cytometry and reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: The results of flow cytometry showed that the purity of MACS-isolated CD4(+)T lymphocytes was 90.0% ± 5.2% and the survival rate 94.8% ± 3.2%. The protein (28.0% ± 3.5%, 14.9% ± 3.4%) and mRNA levels (0.55 ± 0.16, 1.38 ± 0.42) of Cyclin A and Cyclin D1 in CD4(+)T lymphocytes of asthma group were significantly higher than those of the control group (13.4% ± 3.5%, 7.7% ± 1.8% and 0.32 ± 0.10, 0.92 ± 0.37) (P = 0.002, 0.036 and P = 0.007, 0.042). The protein and mRNA levels (23.3% ± 3.9% and 0.16 ± 0.03) of P27(kip1) of asthma group were significantly lower than those of control group (37.5% ± 5.8% and 0.32 ± 0.03, P = 0.006 and P = 0.000). The protein and mRNA levels of Cyclin D1 in groups A, B, C and D-treated CD4(+)T lymphocytes were 12.2% ± 3.7%, 7.3% ± 3.0%, 8.1% ± 2.3%, 4.2% ± 1.7% and 1.71 ± 0.44, 1.07 ± 0.31, 1.21 ± 0.32 and 0.62 ± 0.20 respectively; groups B, C and D decreased markedly compared with group A (all P < 0.01) while group D decreased significantly compared with groups B and C (all P < 0.05). The protein levels of P27(kip1) in groups A, B, C and D were 22.9% ± 3.0%, 31.6% ± 5.3%, 28.4% ± 5.6% and 44.6% ± 2.8% respectively; group B was significantly higher than that of group A (P = 0.016) while group D was significantly higher than those of groups A, B and C (P = 0.003, 0.004, 0.000). Meanwhile P27(kip1) mRNA levels in each group were 0.16 ± 0.07, 0.36 ± 0.09, 0.63 ± 0.08 and 0.99 ± 0.21 respectively; groups B, C and D were much higher than that of group A (P = 0.016, 0.000, 0.000) while group D was significantly higher than those of groups B and C (P = 0.000, 0.023). The protein and mRNA levels of CylinA showed no statistical significance among different experimental groups (all P > 0.05). CONCLUSION: The signal pathways of PI3K and Notch may coordinately up-regulate the expression of positive regulatory factor cylinD1 and down-regulation the expression of negative regulatory factor P27(kip1) of CD4(+)T lymphocytes.


Assuntos
Asma/metabolismo , Linfócitos T CD4-Positivos/citologia , Fosfatidilinositol 3-Quinases/metabolismo , Receptores Notch/metabolismo , Transdução de Sinais , Animais , Asma/patologia , Linfócitos T CD4-Positivos/metabolismo , Proliferação de Células , Ciclina D1/metabolismo , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Ativação Linfocitária , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Inibidores de Fosfoinositídeo-3 Quinase , Receptores Notch/antagonistas & inibidores
20.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 44(2): 209-12, 2013 Mar.
Artigo em Zh | MEDLINE | ID: mdl-23745257

RESUMO

OBJECTIVE: To investigate the effects of chronic morphine administration on pain behaviors in young rats and to explore the mechanisms involved. METHODS: Sixteen SD young rats of 3-4 weeks were randomly divided into control and morphine administration groups. Young rats received saline (1 mL/kg) or morphine (10 mg/kg) subcutaneously. Each regimen was given once daily for 14 days. Pain behaviors were examined on day 1, 3, 5, 7, and 14 before the daily drug administration. Western blot was used to examine the expression of glutamate decarboxylase 65 (GAD65) in the spinal cord dorsal horn on day 14 after the last drug administration. RESULTS: Following 14 days of morphine administration, mechanical hyperalgesia was induced in young rats. Compared with control group, the mechanical withdrawal threshold of morphine group significantly decreased on days 3, 5,7 and 14. Chronic administration of morphine downregulated the expression of GAD65 in the spinal cord dorsal horn of young rats. CONCLUSION: Chronic morphine administration could induce mechanical hyperalgesia in young rats, and the downregulation of GAD65 in the spinal cord dorsal horn might play a critical role in the molecular mechanisms of morphine-induced hyperalgesia.


Assuntos
Glutamato Descarboxilase/metabolismo , Hiperalgesia/induzido quimicamente , Morfina/administração & dosagem , Morfina/efeitos adversos , Analgésicos Opioides/administração & dosagem , Analgésicos Opioides/efeitos adversos , Animais , Regulação para Baixo , Masculino , Células do Corno Posterior/enzimologia , Ratos , Ratos Sprague-Dawley , Medula Espinal/enzimologia , Fatores de Tempo
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