Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 247
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
J Neurosci ; 44(7)2024 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-38233216

RESUMEN

While functional brain imaging studies in humans suggest that chronic cocaine use alters functional connectivity (FC) within and between key large-scale brain networks, including the default mode network (DMN), the salience network (SN), and the central executive network (CEN), cross-sectional studies in humans are challenging to obtain brain FC prior to cocaine use. Such information is critical to reveal the relationship between individual's brain FC and the subsequent development of cocaine dependence and brain changes during abstinence. Here, we performed a longitudinal study examining functional magnetic resonance imaging (fMRI) data in male rats (n = 7), acquired before cocaine self-administration (baseline), on 1 d of abstinence following 10 d of cocaine self-administration, and again after 30 d of experimenter-imposed abstinence. Using repeated-measures analysis of variance (ANOVA) with network-based statistics (NBS), significant connectivity changes were found between anterior insular cortex (AI) of the SN, retrosplenial cortex (RSC) of the DMN, somatosensory cortex, and caudate-putamen (CPu), with AI-RSC FC showing the most robust changes between baseline and 1 d of abstinence. Additionally, the level of escalated cocaine intake is associated with AI-RSC and AI-CPu FC changes between 1 d and 30 d of abstinence; further, the subjects' AI-RSC FC prior to cocaine intake is a significant moderator for the AI-RSC changes during abstinence. These results provide novel insights into the roles of AI-RSC FC before and after cocaine intake and suggest this circuit to be a potential target to modulate large-scale network and associated behavioral changes in cocaine use disorders.


Asunto(s)
Trastornos Relacionados con Cocaína , Cocaína , Humanos , Masculino , Animales , Ratas , Giro del Cíngulo , Mapeo Encefálico/métodos , Corteza Insular , Estudios Longitudinales , Estudios Transversales , Encéfalo , Imagen por Resonancia Magnética/métodos , Corteza Cerebral/diagnóstico por imagen , Red Nerviosa
2.
Small ; 20(16): e2307483, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38150612

RESUMEN

The key to design an advanced oxygen reduction reaction (ORR) electrocatalyst is a well-balance between the adsorption and desorption of oxygen intermediates. This study systematically evaluated the ORR activity of HCP and FCC cobalt core-shell cobalt/N-doped carbon (Cobalt@NC) catalyst via theoretical and experimental studies. The electronic structure calculations using density functional theory (DFT) calculations revealed that the ORR activity of carbon layer can be improved by 1) switching the electrostatic potential in the electrical double layer due to the polarization induced at the carbon-cobalt interface and 2) modulating the electron population in the bonding orbital in the C-O bonds in an ORR. The results revealed that an O atom is bounded stronger to the outer NC shell with FCC Cobalt than HCP Cobalt, which hindered the desorption steps of OH*. Experimentally, plasma-engineered HCP Cobalt@NC also showed remarkably advanced performance toward ORR compared to that FCC Cobalt@NC. The kinetic current density of HCP Cobalt@NC at 0.85 V versus RHE is calculated as 6.24 mA cm-2, which is six folds higher than FCC Cobalt@NC and even outperform 20 wt.% Pt/C. In a practical Aluminium-air battery, HCP Cobalt@NC also exhibited slightly higher peak power density (110.57 mW cm-2) compared to 20 wt.% Pt/C.

3.
Plant Cell Environ ; 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38741272

RESUMEN

Excess soil salinity significantly impairs plant growth and development. Our previous reports demonstrated that the core circadian clock oscillator GIGANTEA (GI) negatively regulates salt stress tolerance by sequestering the SALT OVERLY SENSITIVE (SOS) 2 kinase, an essential component of the SOS pathway. Salt stress induces calcium-dependent cytoplasmic GI degradation, resulting in activation of the SOS pathway; however, the precise molecular mechanism governing GI degradation during salt stress remains enigmatic. Here, we demonstrate that salt-induced calcium signals promote the cytoplasmic partitioning of CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1), leading to the 26S proteasome-dependent degradation of GI exclusively in the roots. Salt stress-induced calcium signals accelerate the cytoplasmic localization of COP1 in the root cells, which targets GI for 26S proteasomal degradation. Align with this, the interaction between COP1 and GI is only observed in the roots, not the shoots, under salt-stress conditions. Notably, the gi-201 cop1-4 double mutant shows an enhanced tolerance to salt stress similar to gi-201, indicating that GI is epistatic to COP1 under salt-stress conditions. Taken together, our study provides critical insights into the molecular mechanisms governing the COP1-mediated proteasomal degradation of GI for salt stress tolerance, raising new possibilities for developing salt-tolerant crops.

4.
Environ Res ; 249: 118437, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38346486

RESUMEN

The widespread prevalence of micro and nanoplastics in the environment raises concerns about their potential impact on human health. Recent evidence demonstrates the presence of nanoplastics in human blood and tissues following ingestion and inhalation, yet the specific risks and mechanisms of nanoplastic toxicity remain inadequately understood. In this study, we aimed to explore the molecular mechanisms underlying the toxicity of nanoplastics at both systemic and molecular levels by analyzing the transcriptomic/metabolomic responses and signaling pathways in the intestines of mice after oral administration of nanoplastics. Transcriptome analysis in nanoplastic-administered mice revealed a notable upregulation of genes involved in pro-inflammatory immune responses. In addition, nanoplastics substantially reduced the expression of tight junction proteins, including occludin, zonula occluden-1, and tricellulin, which are crucial for maintaining gut barrier integrity and function. Importantly, nanoplastic administration increased gut permeability and exacerbated dextran sulfate sodium-induced colitis. Further investigation into the underlying molecular mechanisms highlighted significant activation of signaling transsducer and activator of transcription (STAT)1 and STAT6 by nanoplastic administration, which was in line with the elevation of interferon and JAK-STAT pathway signatures identified through transcriptome enrichment analysis. Additionally, the consumption of nanoplastics specifically induced nuclear factor kappa-B (NF-κB) and extracellular signal-regulated kinase (ERK)1/2 signaling pathways in the intestines. Collectively, this study identifies molecular mechanisms contributing to adverse effects mediated by nanoplastics in the intestine, providing novel insights into the pathophysiological consequences of nanoplastic exposure.


Asunto(s)
Factor de Transcripción STAT1 , Animales , Ratones , Factor de Transcripción STAT1/metabolismo , Factor de Transcripción STAT1/genética , Transcriptoma/efectos de los fármacos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Factor de Transcripción STAT6/metabolismo , Factor de Transcripción STAT6/genética , Ratones Endogámicos C57BL , Nanopartículas/toxicidad , Metabolómica , Masculino , Colitis/inducido químicamente , Colitis/metabolismo
5.
Int J Cancer ; 152(4): 713-724, 2023 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-36250346

RESUMEN

Glioblastoma (GBM) is the most common primary intracranial malignant tumor and consists of three molecular subtypes: proneural (PN), mesenchymal (MES) and classical (CL). Transition between PN to MES subtypes (PMT) is the glioma analog of the epithelial-mesenchymal transition (EMT) in carcinomas and is associated with resistance to therapy. CXCR4 signaling increases the expression of MES genes in glioma cell lines and promotes EMT in other cancers. RNA sequencing (RNAseq) data of PN GBMs in The Cancer Genome Atlas (TCGA) and secondary high-grade gliomas (HGGs) from an internal cohort were examined for correlation between CXCR4 expression and survival as well as expression of MES markers. Publicly available single-cell RNA sequencing (scRNAseq) data was analyzed for cell type specific CXCR4 expression. These results were validated in a genetic mouse model of PN GBM. Higher CXCR4 expression was associated with significantly reduced survival and increased expression of MES markers in TCGA and internal cohorts. CXCR4 was expressed in immune and tumor cells based on scRNAseq analysis. Higher CXCR4 expression within tumor cells on scRNAseq was associated with increased MES phenotype, suggesting a cell-autonomous effect. In a genetically engineered mouse model, tumors induced with CXCR4 exhibited a mesenchymal phenotype and shortened survival. These results suggest that CXCR4 signaling promotes PMT and shortens survival in GBM and highlights its inhibition as a potential therapeutic strategy.


Asunto(s)
Neoplasias Encefálicas , Glioblastoma , Glioma , Animales , Ratones , Neoplasias Encefálicas/patología , Línea Celular Tumoral , Transición Epitelial-Mesenquimal/genética , Regulación Neoplásica de la Expresión Génica , Glioblastoma/patología , Glioma/genética , Fenotipo , Humanos
6.
Small ; 19(32): e2206839, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37069777

RESUMEN

Peripheral nerve injuries cause various disabilities related to loss of motor and sensory functions. The treatment of these injuries typically requires surgical operations for improving functional recovery of the nerve. However, capabilities for continuous nerve monitoring remain a challenge. Herein, a battery-free, wireless, cuff-type, implantable, multimodal physical sensing platform for continuous in vivo monitoring of temperature and strain from the injured nerve is introduced. The thin, soft temperature, and strain sensors wrapped around the nerve exhibit good sensitivity, excellent stability, high linearity, and minimum hysteresis in relevant ranges. In particular, the strain sensor integrated with circuits for temperature compensation provides reliable, accurate strain monitoring with negligible temperature dependence. The system enables power harvesting and data communication to wireless, multiple implanted devices wrapped around the nerve. Experimental evaluations, verified by numerical simulations, with animal tests, demonstrate the feasibility and stability of the sensor system, which has great potential for continuous in vivo nerve monitoring from an early stage to complete regeneration.


Asunto(s)
Suministros de Energía Eléctrica , Prótesis e Implantes , Animales , Temperatura , Tecnología Inalámbrica
7.
Reproduction ; 165(1): 135-146, 2023 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-36322471

RESUMEN

In brief: Mealtime changes in pregnant mice revealed impaired neurobehavioral development in mouse offspring. This study is the basis for investigating diseases associated with neurobehavioral development of adult offspring of pregnant shift-working women. Abstract: Most organisms on Earth have a biological clock, and their physiological processes are regulated by a 1-day cycle. In modern society, several factors can disturb these biological clocks in humans; in particular, individuals working in shifts are exposed to stark environmental changes that interfere with their biological clock. They have a high risk of various diseases. However, there are scarce experimental approaches to address the reproductive and health consequences of shift work in the offspring of exposed individuals. In this study, considering the fact that shift workers usually have their meals during their adjusted working time, we aimed to examine the effects of a 12-h shift with usual mealtime as a plausible night work model on the neurobehavioral development of adult mouse offspring. In these offspring, early exposure to this mealtime shift differentially affected circadian rhythmic variables and total locomotor activity depending on the timing and duration of restrictive feeding. Moreover, neurobehavioral alterations such as declined short-term memory and depressive-like behavior were observed in adulthood. These results have implications for the health concerns of shift-working women and their children.


Asunto(s)
Hijos Adultos , Ritmo Circadiano , Humanos , Embarazo , Adulto , Niño , Animales , Femenino , Ratones , Ritmo Circadiano/fisiología , Destete , Conducta Animal , Reproducción
8.
Photochem Photobiol Sci ; 22(11): 2563-2572, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37632684

RESUMEN

BACKGROUND: This study assessed the therapeutic efficacy of intraperitoneal photodynamic therapy (PDT) using photosensitizer activation at two different wavelengths, 405 and 664 nm, in a mouse model of peritoneal carcinomatosis. METHODS: The dark and light cytotoxicity of chlorin e6-polyvinylpyrrolidone (Phonozen) were measured in vitro under 402 ± 14 and 670 ± 18 nm LED activation in bioluminescent human gastric cancer cells, MKN45-luc. Cell viability was measured at 6 h after irradiation using the PrestoBlue assay. Corresponding in vivo studies were performed in athymic nude mice by intraperitoneal injection of 1 × 106 MKN45-luc cells. PDT was performed 10 d after tumor induction and comprised intraperitoneal injection of Phonozen followed by light irradiation at 3 h, delivered by a diffusing-tip optical fiber placed in the peritoneal cavity and coupled to a 405 or 664 nm diode laser to deliver a total energy of 50 J (20 mice per cohort). Whole-body bioluminescence imaging was used to track the tumor burden after PDT out to 130 days, and 5 mice in each cohort were sacrificed at 4 h post treatment to measure the acute tumor necrosis. RESULTS: Photosensitizer dose-dependent photocytotoxicity was higher in vitro at 405 than 664 nm. In vivo, PDT reduced the tumor growth rate at both wavelengths, with no statistically significant difference. There was substantial necrosis, and median survival was significantly prolonged at both wavelengths compared with controls (46 and 46 vs. 34 days). CONCLUSIONS: Phonozen-mediated PDT results in significant cytotoxicity in vitro as well as tumor necrosis and prolonged survival in vivo following intraperitoneal light irradiation. Blue light was more photocytotoxic than red in vitro and had marginally higher efficacy in vivo.


Asunto(s)
Neoplasias Peritoneales , Fotoquimioterapia , Humanos , Ratones , Animales , Fármacos Fotosensibilizantes/farmacología , Fotoquimioterapia/métodos , Neoplasias Peritoneales/tratamiento farmacológico , Ratones Desnudos , Modelos Animales de Enfermedad , Necrosis , Línea Celular Tumoral
9.
Fish Shellfish Immunol ; 137: 108741, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37088346

RESUMEN

Haliotis discus hannai, a food with a high protein content, is widely consumed in Asian countries. It is known to have antioxidant, anticancer, and antibacterial effects. Since the biological significance of H. discus hannai hemolymph has not been widely studied, the objective of the present study was to purify phenoloxidase (PO) and investigate its immunological effects on human colonic epithelial cells. PO was purified through ammonium sulfate precipitation and one step column chromatography. The molecular weight of the protein was about 270 kDa. When PO was mixed with Gram-negative bacteria-derived lipopolysaccharide (LPS) at various ratios (10:1-1:10, w/w), the amount of residual LPS was reduced. PO at concentrations up to 200 µg/mL was not cytotoxic to HT-29 cells. The inflammatory response induced by LPS in HT-29 cells was regulated when the concentration of PO was increased. With increasing concentration of PO, production levels of pro-inflammatory cytokines, cytokines associated with hyperimmune responses such as IL4, IL-5, and INF-γ, and prostaglandin 2 (PGE2) were regulated. It was thought that simultaneous treatment with PO and LPS anti-inflammatory effects in HT-29 cells showed by regulating the ERK1/2-mediated NF-κB pathway. Results of this study suggest that H. discus hannai hemolymph is involved in the regulation of Gram-negative bacteria-related inflammatory immune responses in human colonic epithelial cells.


Asunto(s)
Gastrópodos , Monofenol Monooxigenasa , Animales , Humanos , Monofenol Monooxigenasa/metabolismo , Lipopolisacáridos/farmacología , Lipopolisacáridos/metabolismo , Citocinas/genética , Citocinas/metabolismo , Antiinflamatorios/farmacología , Antiinflamatorios/metabolismo
10.
Chem Rev ; 121(4): 2515-2544, 2021 02 24.
Artículo en Inglés | MEDLINE | ID: mdl-33449621

RESUMEN

This review gives an account on the fast expanding field of monomeric (or molecular) heptazines, at the exclusion of their various polymeric forms, often referred to as carbon nitrides. While examples of monomeric heptazines were extremely limited until the beginning of this century, the field has started expanding quickly since then, as has the number of reports on polymeric materials, though previous reviews did not separate these fields. We provide here a detailed report on the synthetic procedures for molecular heptazines. We also extensively report on the different achievements realized from these new molecules, in the fields of physical chemistry, spectroscopy, materials preparation, (photo)catalysis, and devices. After a comprehensive summary and discussion on heptazines syntheses and characteristics, we show that starting from well-defined molecules allows a versatility of approaches and a wide tunability of the expected properties. It comes out that the field of monomeric heptazines is now emerging and possibly heading toward maturity, while diverging from the one of polymeric carbon nitrides. It is likely that this area of research will quickly surge to the forefront of the search for active organic molecules, with special attention to the domains of catalysis and organic-based functional materials and devices.

11.
Medicina (Kaunas) ; 59(3)2023 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-36984523

RESUMEN

Background: Increased coronary artery calcification (CAC) has been reported in individuals with high levels of physical activity (PA). However, the association between increased CAC in a physically active population and cardiovascular mortality has not yet been well-established. This study aimed to investigate the association between PA levels and the presence or absence of CAC and cardiovascular mortality. Methods: A cohort study was conducted from 1 January 2011 to 30 December 2019. Mortality data were updated until 30 December 2020. The study population comprised 56,469 individuals who had completed the International Physical Activity Short Form Questionnaire and had undergone CAC score evaluation using a CT scan. We divided the participants into four groups: physically inactive individuals without CAC, physically inactive individuals with CAC, moderately active and health-enhancing physically active (HEPA) individuals without CAC, and moderately active and HEPA individuals with CAC. The primary outcome was cardiovascular mortality. The Cox proportional hazard model with confounding factor adjustment was conducted. Inverse probability of treatment weighting-based marginal-structural modelling was conducted. Results: The median follow-up duration was 6.60 years. The mean (SD) age of the study participants was 41.67 (±10.91) years, with 76.78% (n = 43,359) men. Compared with individuals without CAC, individuals with CAC demonstrated higher cardiovascular disease mortality regardless of PA level (Inactive and CAC > 0, HR 2.81, 95% CI: 1.76-19.19; moderately active and HEPA HR 3.27, 95% CI: 1.14-9.38). Conclusions: The presence of CAC might be associated with cardiovascular mortality regardless of PA level.


Asunto(s)
Enfermedades Cardiovasculares , Enfermedad de la Arteria Coronaria , Calcificación Vascular , Masculino , Humanos , Adulto , Persona de Mediana Edad , Estudios de Cohortes , Factores de Riesgo , Medición de Riesgo , Calcificación Vascular/complicaciones , Calcificación Vascular/epidemiología , Enfermedad de la Arteria Coronaria/complicaciones , Enfermedades Cardiovasculares/epidemiología , Ejercicio Físico
12.
Reproduction ; 163(5): 323-331, 2022 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-35286277

RESUMEN

The physiological processes of organisms in this rotating planet can adjust according to the time of day via built-in circadian clocks. However, more people are having different shift works, which can increase the risk of pathological conditions including altered reproductive function. Thus, circadian rhythm disturbance has become prevalent in the modern society. Specifically, epidemiological evidence has shown that shift-working women are at high risk of spontaneous abortions, irregular menstrual cycles, and low-birth-weight babies. The current study aimed to investigate the effects of circadian rhythm disturbances on the reproductive function of mice caused by dietary time shift, which is common among night-shift workers. According to the schedule of restricted feeding, the mice were classified into the free feeding, daytime feeding, and night feeding groups. The fertility indices of each group were then evaluated. Activity monitoring was performed to determine whether pregnancy delay might be attributed to mealtime shift. Moreover, the estrous cycle of female mice and the reproductive phenotype of male mice were investigated. Results showed that a 12-h mealtime shift significantly delayed successful conception, which could be attributed to a disrupted estrous cycle, in adult female mice.


Asunto(s)
Ritmo Circadiano , Tolerancia al Trabajo Programado , Animales , Femenino , Humanos , Masculino , Comidas , Trastornos de la Menstruación , Ratones , Embarazo , Reproducción
13.
Macromol Rapid Commun ; 43(1): e2100467, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34643991

RESUMEN

Even though plastic improved the human standard of living, handling the plastic waste represents an enormous challenge. It takes more than 100 years to decompose discarded or buried waste plastics. Microplastics are one of the causes of significantly pervasive environmental pollutants. The incineration of plastic waste generates toxic gases, underscoring the need for new approaches, in contrast to conventional strategies that are required for recycling plastic waste. Therefore, several studies have attempted to upcycle plastic waste into high value-added products. Converting plastic waste into carbonaceous materials is an excellent upcycling technique due to their diverse practical applications. This review summarizes various studies dealing with the upcycling of plastic waste into carbonaceous products. Further, this review discusses the applications of carbonaceous products synthesized from plastic waste including carbon fibers, absorbents for water purification, and electrodes for energy storage. Based on the findings, future directions for effective upcycling of plastic waste into carbonaceous materials are suggested.


Asunto(s)
Plásticos , Reciclaje , Gases , Humanos
14.
J Korean Med Sci ; 37(18): e146, 2022 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-35535373

RESUMEN

Sarcopenia is a progressive and generalized loss of skeletal muscle mass and function. The prevalence of sarcopenia was reported to be up to 29% in older persons in the community healthcare setting. Sarcopenia diagnosis is confirmed by the presence of low muscle mass plus low muscle strength or low physical performance. Sarcopenia management options include non-pharmacological and pharmacological approaches. Non-pharmacological approaches include resistance exercise and adequate nutrition. Of the two, resistance exercise is the standard non-pharmacological treatment approach for sarcopenia with significant positive evidence. Some dietary approaches such as adequate intake of protein, vitamin D, antioxidant nutrients, and long-chain polyunsaturated fatty acid have been shown to have positive effects against sarcopenia. Currently, no specific drugs have been approved by the Food and Drug Administration for the treatment of sarcopenia. However, several agents, including growth hormone, anabolic or androgenic steroids, selective androgenic receptor modulators, protein anabolic agents, appetite stimulants, myostatin inhibitors, activating II receptor drugs, ß-receptor blockers, angiotensin-converting enzyme inhibitors, and troponin activators, are recommended and have been shown to have variable efficacy. Future research should focus on sarcopenia biological pathway and improved diagnostic approaches such as biomarkers for early detection, development of consistently pre-eminent treatment methods for severe sarcopenia patients, and establishing sensitive measures for predicting sarcopenia treatment response.


Asunto(s)
Sarcopenia , Antagonistas Adrenérgicos beta/uso terapéutico , Anciano , Anciano de 80 o más Años , Ejercicio Físico , Humanos , Fuerza Muscular/fisiología , Músculo Esquelético , Sarcopenia/diagnóstico , Sarcopenia/epidemiología , Sarcopenia/terapia , Vitaminas/uso terapéutico
15.
J Environ Manage ; 307: 114562, 2022 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-35091242

RESUMEN

Valorization of oil sludge has been gaining attention to improve the sustainability of the petroleum industry. This study aimed to assess the possibility of anaerobic co-digestion of oil scum and secondary sludge with food waste (or swine manure). Oil scum and secondary sludge were obtained from a wastewater treatment plant (WWTP) of a petrochemical plant. Physicochemical properties, hazardous materials, and microbial community were characterized and biochemical methane potential was performed by a simplex-lattice mixture design. More than 87% (wet wt.) of the oil scum consisted of total petroleum hydrocarbons (TPHs) (21,762 mg/L) that are difficult to be degraded by anaerobes. The secondary sludge showed low TPHs (5 mg/L) and a bacterial community similar to that of municipal WWTPs. The heavy metal (Cu, As, Cr, Ni, Mn, Zn, and V) concentrations in the oil scum and secondary sludge were similar (20-600 mg/L). The maximum methane potentials of the oil sludge and secondary sludges were 20 ± 2 and 56 ± 3 mL CH4/g-volatile solid, respectively. The co-digestion with food waste or swine manure led to a synergy effect on methane production of the co-digestion substrate (10-40% increase compared to the calculated value; v/v) by balancing the C/N ratio. Due to the high TPH contents, oil scum is not appropriate for co-digestion. The co-digestion of secondary sludge with food waste and/or swine manure is recommended. It is necessary to consider whether the concentration of heavy metals is at a level that inhibits the anaerobic co-digestion depending on the operating conditions such as mixing ratios and solid contents.


Asunto(s)
Petróleo , Eliminación de Residuos , Anaerobiosis , Animales , Biocombustibles/análisis , Reactores Biológicos , Digestión , Alimentos , Estiércol , Metano , Aguas del Alcantarillado , Porcinos
16.
Neuroimage ; 244: 118634, 2021 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-34624504

RESUMEN

The vascular contributions of neurotransmitters to the hemodynamic response are gaining more attention in neuroimaging studies, as many neurotransmitters are vasomodulatory. To date, well-established electrochemical techniques that detect neurotransmission in high magnetic field environments are limited. Here, we propose an experimental setting enabling simultaneous fast-scan cyclic voltammetry (FSCV) and blood oxygenation level-dependent functional magnetic imaging (BOLD fMRI) to measure both local tissue oxygen and dopamine responses, and global BOLD changes, respectively. By using MR-compatible materials and the proposed data acquisition schemes, FSCV detected physiological analyte concentrations with high temporal resolution and spatial specificity inside of a 9.4 T MRI bore. We found that tissue oxygen and BOLD correlate strongly, and brain regions that encode dopamine amplitude differences can be identified via modeling simultaneously acquired dopamine FSCV and BOLD fMRI time-courses. This technique provides complementary neurochemical and hemodynamic information and expands the scope of studying the influence of local neurotransmitter release over the entire brain.


Asunto(s)
Encéfalo/diagnóstico por imagen , Técnicas Electroquímicas/métodos , Imagen por Resonancia Magnética/métodos , Neurotransmisores/fisiología , Oxígeno , Animales , Masculino , Neuroimagen , Ratas , Transmisión Sináptica
17.
Neuroimage ; 238: 118213, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34116153

RESUMEN

Superparamagnetic iron-oxide nanoparticles are robust contrast agents for magnetic resonance imaging (MRI) used for sensitive structural and functional mapping of the cerebral blood volume (CBV) when administered intravenously. To date, many CBV-MRI studies are conducted with Feraheme, manufactured for the clinical treatment of iron-deficiency. Unfortunately, Feraheme is currently not available outside the United States due to commercial and regulatory constraints, making CBV-MRI methods either inaccessible or very costly to achieve. To address this barrier, we developed a simple, one-pot recipe to synthesize Carboxymethyl-dextran coated Iron Oxide Nanoparticles, namely, "CION", suitable for preclinical CBV-MRI applications. Here we disseminate a step-by-step instruction of our one-pot synthesis protocol, which allows CION to be produced in laboratories with minimal cost. We also characterized different CION-conjugations by manipulating polymer to metal stoichiometric ratio in terms of their size, surface chemistry, and chemical composition, and shifts in MR relaxivity and pharmacokinetics. We performed several proof-of-concept experiments in vivo, demonstrating the utility of CION for functional and structural MRI applications, including hypercapnic CO2 challenge, visual stimulation, targeted optogenetic stimulation, and microangiography. We also present evidence that CION can serve as a cross-modality research platform by showing concurrent in vivo optical and MRI measurement of CBV using fluorescent-labeled CION. The simplicity and cost-effectiveness of our one-pot synthesis method should allow researchers to reproduce CION and tailor the relaxivity and pharmacokinetics according to their imaging needs. It is our hope that this work makes CBV-MRI more openly available and affordable for a variety of research applications.


Asunto(s)
Medios de Contraste , Dextranos/síntesis química , Nanopartículas Magnéticas de Óxido de Hierro , Imagen por Resonancia Magnética/métodos , Humanos
18.
Neuroimage ; 243: 118541, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34478824

RESUMEN

Resting-state functional magnetic resonance imaging (fMRI) has drastically expanded the scope of brain research by advancing our knowledge about the topologies, dynamics, and interspecies translatability of functional brain networks. Several databases have been developed and shared in accordance with recent key initiatives in the rodent fMRI community to enhance the transparency, reproducibility, and interpretability of data acquired at various sites. Despite these pioneering efforts, one notable challenge preventing efficient standardization in the field is the customary choice of anisotropic echo planar imaging (EPI) schemes with limited spatial coverage. Imaging with anisotropic resolution and/or reduced brain coverage has significant shortcomings including reduced registration accuracy and increased deviation in brain feature detection. Here we proposed a high-spatial-resolution (0.4 mm), isotropic, whole-brain EPI protocol for the rat brain using a horizontal slicing scheme that can maintain a functionally relevant repetition time (TR), avoid high gradient duty cycles, and offer unequivocal whole-brain coverage. Using this protocol, we acquired resting-state EPI fMRI data from 87 healthy rats under the widely used dexmedetomidine sedation supplemented with low-dose isoflurane on a 9.4 T MRI system. We developed an EPI template that closely approximates the Paxinos and Watson's rat brain coordinate system and demonstrated its ability to improve the accuracy of group-level approaches and streamline fMRI data pre-processing. Using this database, we employed a multi-scale dictionary-learning approach to identify reliable spatiotemporal features representing rat brain intrinsic activity. Subsequently, we performed k-means clustering on those features to obtain spatially discrete, functional regions of interest (ROIs). Using Euclidean-based hierarchical clustering and modularity-based partitioning, we identified the topological organizations of the rat brain. Additionally, the identified group-level FC network appeared robust across strains and sexes. The "triple-network" commonly adapted in human fMRI were resembled in the rat brain. Through this work, we disseminate raw and pre-processed isotropic EPI data, a rat brain EPI template, as well as identified functional ROIs and networks in standardized rat brain coordinates. We also make our analytical pipelines and scripts publicly available, with the hope of facilitating rat brain resting-state fMRI study standardization.


Asunto(s)
Encéfalo/diagnóstico por imagen , Imagen Eco-Planar/métodos , Animales , Mapeo Encefálico/métodos , Análisis por Conglomerados , Procesamiento de Imagen Asistido por Computador/métodos , Isoflurano , Masculino , Ratas , Reproducibilidad de los Resultados
19.
Bioinformatics ; 36(5): 1584-1589, 2020 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-31599923

RESUMEN

MOTIVATION: Owing to advanced DNA sequencing and genome assembly technology, the number of species with sequenced genomes is rapidly increasing. The aim of the recently launched Earth BioGenome Project is to sequence genomes of all eukaryotic species on Earth over the next 10 years, making it feasible to obtain genomic blueprints of the majority of animal and plant species by this time. Genetic models of the sequenced species will later be subject to functional annotation, and a comprehensive molecular network should facilitate functional analysis of individual genes and pathways. However, network databases are lagging behind genome sequencing projects as even the largest network database provides gene networks for less than 10% of sequenced eukaryotic genomes, and the knowledge gap between genomes and interactomes continues to widen. RESULTS: We present BiomeNet, a database of 95 scored networks comprising over 8 million co-functional links, which can build and analyze gene networks for any species with the sequenced genome. BiomeNet transfers functional interactions between orthologous proteins from source networks to the target species within minutes and automatically constructs gene networks with the quality comparable to that of existing networks. BiomeNet enables assembly of the first-in-species gene networks not available through other databases, which are highly predictive of diverse biological processes and can also provide network analysis by extracting subnetworks for individual biological processes and network-based gene prioritizations. These data indicate that BiomeNet could enhance the benefits of decoding the genomes of various species, thus improving our understanding of the Earth' biodiversity. AVAILABILITY AND IMPLEMENTATION: The BiomeNet is freely available at http://kobic.re.kr/biomenet/. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Asunto(s)
Bases de Datos Genéticas , Genoma , Animales , Redes Reguladoras de Genes , Genómica , Análisis de Secuencia de ADN
20.
Anal Bioanal Chem ; 413(4): 1193-1202, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33403427

RESUMEN

Carbon fiber (CNF), prepared by carbonization of electrospun polyacrylonitrile (PAN) fibers, is systematically investigated as a mediator to replace conventional organic matrices for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-MS). CNF exhibits a high salt tolerance, sensitivity, and resolution for organic matrix-free laser desorption/ionization time-of-flight mass spectrometry (LDI-MS) analysis of various analytes under both positive and negative ionization modes. Especially, saccharides, a neutral molecule having low negative ionization efficiency, are successfully detected with CNF. Taken together, this study clearly demonstrates CNF is a promising material to develop an efficient and universal platform for LDI-MS analysis regardless of preferential ionization modes of analytes. Graphical abstract.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA