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1.
Nano Lett ; 24(3): 958-965, 2024 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-38207219

RESUMEN

Photoelectrochemical (PEC) water splitting in acidic media holds promise as an efficient approach to renewable hydrogen production. However, the development of highly active and stable photoanodes under acidic conditions remains a significant challenge. Herein, we demonstrate the remarkable water oxidation performance of Ru single atom decorated hematite (Fe2O3) photoanodes, resulting in a high photocurrent of 1.42 mA cm-2 at 1.23 VRHE under acidic conditions. Comprehensive experimental and theoretical investigations shed light on the mechanisms underlying the superior activity of the Ru-decorated photoanode. The presence of single Ru atoms enhances the separation and transfer of photogenerated carriers, facilitating efficient water oxidation kinetics on the Fe2O3 surface. This is achieved by creating additional energy levels within the Fe2O3 bandgap and optimizing the free adsorption energy of intermediates. These modifications effectively lower the energy barrier of the rate-determining step for water splitting, thereby promoting efficient PEC hydrogen production.

2.
J Physiol ; 2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-38953534

RESUMEN

The central histaminergic system has a pivotal role in emotional regulation and psychiatric disorders, including anxiety, depression and schizophrenia. However, the effect of histamine on neuronal activity of the centrolateral amygdala (CeL), an essential node for fear and anxiety processing, remains unknown. Here, using immunostaining and whole-cell patch clamp recording combined with optogenetic manipulation of histaminergic terminals in CeL slices prepared from histidine decarboxylase (HDC)-Cre rats, we show that histamine selectively suppresses excitatory synaptic transmissions, including glutamatergic transmission from the basolateral amygdala, on both PKC-δ- and SOM-positive CeL neurons. The histamine-induced effect is mediated by H3 receptors expressed on VGLUT1-/VGLUT2-positive presynaptic terminals in CeL. Furthermore, optoactivation of histaminergic afferent terminals from the hypothalamic tuberomammillary nucleus (TMN) also significantly suppresses glutamatergic transmissions in CeL via H3 receptors. Histamine neither modulates inhibitory synaptic transmission by presynaptic H3 receptors nor directly excites CeL neurons by postsynaptic H1, H2 or H4 receptors. These results suggest that histaminergic afferent inputs and presynaptic H3 heteroreceptors may hold a critical position in balancing excitatory and inhibitory synaptic transmissions in CeL by selective modulation of glutamatergic drive, which may not only account for the pathophysiology of psychiatric disorders but also provide potential psychotherapeutic targets. KEY POINTS: Histamine selectively suppresses the excitatory, rather than inhibitory, synaptic transmissions on both PKC-δ- and SOM-positive neurons in the centrolateral amygdala (CeL). H3 receptors expressed on VGLUT1- or VGLUT2-positive afferent terminals mediate the suppression of histamine on glutamatergic synaptic transmission in CeL. Optogenetic activation of hypothalamic tuberomammillary nucleus (TMN)-CeL histaminergic projections inhibits glutamatergic transmission in CeL via H3 receptors.

3.
J Am Chem Soc ; 146(10): 6846-6855, 2024 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-38424010

RESUMEN

This investigation probes the intricate interplay of catalyst dynamics and reaction pathways during the oxygen evolution reaction (OER), highlighting the significance of atomic-level and local ligand structure insights in crafting highly active electrocatalysts. Leveraging a tailored ion exchange reaction followed by electrochemical dynamic reconstruction, we engineered a novel catalytic structure featuring single Ir atoms anchored to NiOOH (Ir1@NiOOH). This novel approach involved the strategic replacement of Fe with Ir, facilitating the transition of selenide precatalysts into active (oxy)hydroxides. This elemental substitution promoted an upward shift in the O 2p band and intensified the metal-oxygen covalency, thereby altering the OER mechanism toward enhanced activity. The shift from a single-metal site mechanism (SMSM) in NiOOH to a dual-metal-site mechanism (DMSM) in Ir1@NiOOH was substantiated by in situ differential electrochemical mass spectrometry (DEMS) and supported by theoretical insights. Remarkably, the Ir1@NiOOH electrode exhibited exceptional electrocatalytic performance, achieving overpotentials as low as 142 and 308 mV at current densities of 10 and 1000 mA cm-2, respectively, setting a new benchmark for the electrocatalysis of OER.

4.
Gynecol Endocrinol ; 40(1): 2351525, 2024 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38726683

RESUMEN

OBJECTIVE: Stable luteal cell function is an important prerequisite for reproductive ability and embryonic development. However, luteal insufficiency seriously harms couples who have the desire to have a pregnancy, and the most important thing is that there is no complete solution. In addition, Vaspin has been shown to have regulatory effects on luteal cells, but the complex mechanisms involved have not been fully elucidated. Therefore, this study aimed to explore the effect of Vaspin on rat luteal cells and its mechanism. METHODS: Granulosa lutein cells separated from the ovary of female rats were incubated for 24h with gradient concentrations of Vaspin, and granulosa lutein cells incubated with 0.5% bovine serum albumin were used as controls. The proliferation, apoptosis, angiogenesis, progesterone (P4) and estradiol (E2) were detected by CCK-8, Anneixn-FITC/PI staining, angiogenesis experiment and ELISA. Western blot was applied to observe the expression levels of proteins related to cell proliferation, apoptosis, angiogenesis and MEK/MAPK signaling pathway. RESULTS: Compared with the Control group, Vaspin could significantly up-regulate the proliferation of granulosa lutein cells and reduce the apoptosis. Moreover, Vaspin promoted the angiogenesis of granulosa lutein cells and the production of P4 and E2 in a concentration-dependent manner. Furthermore, Vaspin up-regulated the CyclinD1, CyclinB1, Bcl2, VEGFA and FGF-2 expression in granulosa lutein cells, and down-regulated the level of Bax. Also, Vaspin increased the p-MEK1 and p-p38 levels. CONCLUSION: Vaspin can up-regulate the proliferation and steroidogenesis of rat luteal cells and reduce apoptosis, which may be related to the influence of MEK/MAPK activity.


Asunto(s)
Apoptosis , Proliferación Celular , Células Lúteas , Progesterona , Serpinas , Animales , Femenino , Proliferación Celular/efectos de los fármacos , Serpinas/metabolismo , Serpinas/farmacología , Ratas , Células Lúteas/efectos de los fármacos , Células Lúteas/metabolismo , Apoptosis/efectos de los fármacos , Progesterona/farmacología , Estradiol/farmacología , Células Cultivadas , Ratas Sprague-Dawley , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Neovascularización Fisiológica/efectos de los fármacos
5.
J Asian Nat Prod Res ; : 1-9, 2024 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-38963070

RESUMEN

Five new glycosides, namely methyl 3-methoxybenzoate-4,5-di-O-ß-D-glucopyranoside (1), (1aS,3aS,3R)-3-(4'-O-ß-D-glucopyranosyl-3'-methoxyphenyl)-5,6-dioxa-bicyclo[3.3.0]octane-1-one (2), quinolin-4(1H)-one-3-O-ß-D-glucopyranoside (3), 3-methoxy-propiophenone 4-O-(6'-ß-D-xylopyranosyl)-ß-D-glucopyranoside (4), methyl 3-methoxybenzoate 4-O-(6'-ß-D-xylopyranosyl)-ß-D-glucopyranoside (5), and one known compound, bambulignan B (6) were isolated from the culms of Phyllostachys nigra var. henonis. Their structures were determined using spectroscopic analysis. All compounds were evaluated for their DPPH radical scavenging activity. Compound 6 exhibited antioxidant activity with IC50 value of 59.5 µM (positive control, L-ascorbic acid, IC50 = 12.4 µM; 2,6-ditertbutyl-4-methyl phenol, IC50 = 11.8 µM).

6.
Nano Lett ; 23(6): 2354-2361, 2023 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-36853807

RESUMEN

Ir-based materials are still the benchmark catalysts for various reactions in acidic environment, but the high loading and low atom utilization limit their large-scale deployment. Herein, we report an effective strategy for implanting fully dispersed iridium-oxide atomic clusters onto hematite for boosting photoelectrochemical water oxidation in acidic solution. The resulting photoanode achieves a record-high photocurrent of 1.35 mA cm-2 at 1.23 V, corresponding to a mass activity of 172.70 A g-1 (3 times higher than electrodeposited control sample) and demonstrating the merits from the high atomic utilization of Ir. The systematically experimental and theoretical results reveal that the performance improvement correlates with the modulated electronic structure including the adjusted Fermi level and d-band center, which significantly enhances charge separation efficiency and promotes the conversion from intermediate *O into *OOH.

7.
Molecules ; 29(12)2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38930848

RESUMEN

The photoelectrochemical (PEC) conversion of organic small molecules offers a dual benefit of synthesizing value-added chemicals and concurrently producing hydrogen (H2). Ethylene glycol, with its dual hydroxyl groups, stands out as a versatile organic substrate capable of yielding various C1 and C2 chemicals. In this study, we demonstrate that pH modulation markedly enhances the photocurrent of BiVO4 photoanodes, thus facilitating the efficient oxidation of ethylene glycol while simultaneously generating H2. Our findings reveal that in a pH = 1 ethylene glycol solution, the photocurrent density at 1.23 V vs. RHE can attain an impressive 7.1 mA cm-2, significantly surpassing the outputs in neutral and highly alkaline environments. The increase in photocurrent is attributed to the augmented adsorption of ethylene glycol on BiVO4 under acidic conditions, which in turn elevates the activity of the oxidation reaction, culminating in the maximal production of formic acid. This investigation sheds light on the pivotal role of electrolyte pH in the PEC oxidation process and underscores the potential of the PEC strategy for biomass valorization into value-added products alongside H2 fuel generation.

8.
Small ; 19(48): e2302970, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37594726

RESUMEN

Regulating the electronic structure of active sites and monitoring the evolution of the active component is essential to improve the intrinsic activity of catalysts for electrochemical reactions. Herein, a highly efficient pre-electrocatalyst of iron diselenide with rich Se vacancies achieved by phosphorus doping (denoted as P-FeSe2 ) for oxygen evolution reaction (OER) is reported. Systematically experimental and theoretical results show that the formed Se vacancies with phosphorus doping can synergistically modulate the electronic structure of FeSe2 and facilitate OER kinetics with the resulting enhanced electrical conductivity and electrochemical surface area. Importantly, the in situ formed FeOOH species on the surface of the P-FeSe2 nanorods (denoted as P-FeOOH(Se)) during the OER process acts as an active component to efficiently catalyze OER and exhibits a low overpotential of 217 mV to reach 10 mA cm-2 with good durability. Promisingly, an alkaline electrolyzer assembled with P-FeOOH(Se) and Pt/C electrodes requires an ultra-low cell voltage of 1.50 V at 10 mA cm-2 for overall water splitting, which is superior to the RuO2 || Pt/C counterpart and most of the state-of-the-art electrolyzers, demonstrating the high potential of the fabricated electrocatalyst by P doping strategy to explore more highly efficient selenide-based catalysts for various reactions.

9.
Cerebellum ; 22(5): 888-904, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36040660

RESUMEN

The classical motor center cerebellum is one of the most consistent structures of abnormality in autism spectrum disorders (ASD), and neuropeptide oxytocin is increasingly explored as a potential pharmacotherapy for ASD. However, whether oxytocin targets the cerebellum for therapeutic effects remains unclear. Here, we report a localization of oxytocin receptor (OXTR) in Purkinje cells (PCs) of cerebellar lobule Crus I, which is functionally connected with ASD-implicated circuits. OXTR activation neither affects firing activities, intrinsic excitability, and synaptic transmission of normal PCs nor improves abnormal intrinsic excitability and synaptic transmission of PCs in maternal immune activation (MIA) mouse model of autism. Furthermore, blockage of OXTR in Crus I in wild-type mice does not induce autistic-like social, stereotypic, cognitive, and anxiety-like behaviors. These results suggest that oxytocin signaling in Crus I PCs seems to be uninvolved in ASD pathophysiology, and contribute to understanding of targets and mechanisms of oxytocin in ASD treatment.


Asunto(s)
Trastorno del Espectro Autista , Trastorno Autístico , Ratones , Animales , Receptores de Oxitocina , Oxitocina , Células de Purkinje
10.
Pharmacol Res ; 191: 106773, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-37068531

RESUMEN

Specific medications to combat cerebellar ataxias, a group of debilitating movement disorders characterized by difficulty with walking, balance and coordination, are still lacking. Notably, cerebellar microglial activation appears to be a common feature in different types of ataxic patients and rodent models. However, direct evidence that cerebellar microglial activation in vivo is sufficient to induce ataxia is still lacking. Here, by employing chemogenetic approaches to manipulate cerebellar microglia selectively and directly, we found that specific chemogenetic activation of microglia in the cerebellar vermis directly leads to ataxia symptoms in wild-type mice and aggravated ataxic motor deficits in 3-acetylpyridine (3-AP) mice, a classic mouse model of cerebellar ataxia. Mechanistically, cerebellar microglial proinflammatory activation induced by either chemogenetic M3D(Gq) stimulation or 3-AP modeling hyperexcites Purkinje cells (PCs), which consequently triggers ataxia. Blockade of microglia-derived TNF-α, one of the most important proinflammatory cytokines, attenuates the hyperactivity of PCs driven by microglia. Moreover, chemogenetic inhibition of cerebellar microglial activation or suppression of cerebellar microglial activation by PLX3397 and minocycline reduces the production of proinflammatory cytokines, including TNF-α, to effectively restore the overactivation of PCs and alleviate motor deficits in 3-AP mice. These results suggest that cerebellar microglial activation may aggravate the neuroinflammatory response and subsequently induce dysfunction of PCs, which in turn triggers ataxic motor deficits. Our findings thus reveal a causal relationship between proinflammatory activation of cerebellar microglia and ataxic motor symptoms, which may offer novel evidence for therapeutic intervention for cerebellar ataxias by targeting microglia and microglia-derived inflammatory mediators.


Asunto(s)
Ataxia Cerebelosa , Ratones , Animales , Ataxia Cerebelosa/inducido químicamente , Células de Purkinje/fisiología , Microglía , Factor de Necrosis Tumoral alfa/farmacología , Cerebelo , Citocinas
11.
Proc Natl Acad Sci U S A ; 117(50): 32155-32164, 2020 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-33257584

RESUMEN

Anxiety commonly co-occurs with obsessive-compulsive disorder (OCD). Both of them are closely related to stress. However, the shared neurobiological substrates and therapeutic targets remain unclear. Here we report an amelioration of both anxiety and OCD via the histamine presynaptic H3 heteroreceptor on glutamatergic afferent terminals from the prelimbic prefrontal cortex (PrL) to the nucleus accumbens (NAc) core, a vital node in the limbic loop. The NAc core receives direct hypothalamic histaminergic projections, and optogenetic activation of hypothalamic NAc core histaminergic afferents selectively suppresses glutamatergic rather than GABAergic synaptic transmission in the NAc core via the H3 receptor and thus produces an anxiolytic effect and improves anxiety- and obsessive-compulsive-like behaviors induced by restraint stress. Although the H3 receptor is expressed in glutamatergic afferent terminals from the PrL, basolateral amygdala (BLA), and ventral hippocampus (vHipp), rather than the thalamus, only the PrL- and not BLA- and vHipp-NAc core glutamatergic pathways among the glutamatergic afferent inputs to the NAc core is responsible for co-occurrence of anxiety- and obsessive-compulsive-like behaviors. Furthermore, activation of the H3 receptor ameliorates anxiety and obsessive-compulsive-like behaviors induced by optogenetic excitation of the PrL-NAc glutamatergic afferents. These results demonstrate a common mechanism regulating anxiety- and obsessive-compulsive-like behaviors and provide insight into the clinical treatment strategy for OCD with comorbid anxiety by targeting the histamine H3 receptor in the NAc core.


Asunto(s)
Trastornos de Ansiedad/tratamiento farmacológico , Agonistas de los Receptores Histamínicos/administración & dosificación , Núcleo Accumbens/fisiopatología , Trastorno Obsesivo Compulsivo/tratamiento farmacológico , Receptores Histamínicos H3/metabolismo , Vías Aferentes/efectos de los fármacos , Vías Aferentes/fisiopatología , Animales , Trastornos de Ansiedad/etiología , Trastornos de Ansiedad/fisiopatología , Trastornos de Ansiedad/psicología , Modelos Animales de Enfermedad , Glutamatos/metabolismo , Histamina/metabolismo , Antagonistas de los Receptores Histamínicos H3/administración & dosificación , Humanos , Área Hipotalámica Lateral/efectos de los fármacos , Área Hipotalámica Lateral/fisiopatología , Masculino , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Núcleo Accumbens/citología , Núcleo Accumbens/efectos de los fármacos , Trastorno Obsesivo Compulsivo/etiología , Trastorno Obsesivo Compulsivo/fisiopatología , Trastorno Obsesivo Compulsivo/psicología , Optogenética , Técnicas de Placa-Clamp , Corteza Prefrontal/citología , Corteza Prefrontal/efectos de los fármacos , Corteza Prefrontal/fisiopatología , Terminales Presinápticos/efectos de los fármacos , Terminales Presinápticos/metabolismo , Ratas , Ratas Transgénicas , Técnicas Estereotáxicas , Estrés Psicológico/complicaciones , Estrés Psicológico/psicología , Transmisión Sináptica/efectos de los fármacos , Transmisión Sináptica/fisiología
12.
Hepatobiliary Pancreat Dis Int ; 22(3): 263-269, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36435702

RESUMEN

BACKGROUND: The effective treatment for hepatocellular carcinoma (HCC) depends on early diagnosis. Previously, the abnormal expression of Wnt3a as the key signaling molecule in the Wnt/ß-catenin pathway was found in HCC cells and could be released into the circulation. In this study, we used rat model of hepatocarcinogenesis to dynamically investigate the alteration of oncogenic Wnt3a and to explore its early monitor value for HCC. METHODS: Sprague-Dawley rats (SD) were fed with diet 2-fluorenylacetamide (2-FAA, 0.05%) for inducing hepatocarcinogenesis, and grouped based on liver morphological alteration by Hematoxylin & Eosin (H&E) staining; rats fed with normal chow were used as normal control (NC). Total RNA and protein were purified from rat livers. Differently expressed genes (DEGs) or Wnt3a mRNA, cellular distribution, and Wnt3a protein levels were analyzed by whole genome microarray with signal logarithm ratio (SLR log2cy5/cy3), immunohistochemistry, and enzyme-linked immunosorbent assay, respectively. RESULTS: Models of rat hepatocarcinogenesis were successfully established based on liver histopathological H&E staining. Rats were divided into the cell degeneration (rDeg), precancerosis (rPre-C) and HCC (rHCC) groups. Total numbers of the up- and down-regulated DEGs with SLR ≥ 8 were 55 and 48 in the rDeg group, 268 and 57 in the rPre-C group, and 312 and 201 in the rHCC group, respectively. Significantly altered genes were involved in cell proliferation, signal transduction, tumor metastasis, and apoptosis. Compared with the NC group, Wnt3a mRNA was increased by 4.6 folds (P < 0.001) in the rDeg group, 7.4 folds (P < 0.001) in the rPre-C group, and 10.4 folds (P < 0.001) in the rHCC group; the positive rates of liver Wnt3a were 66.7% (P = 0.001) in the rDeg group, 100% (P < 0.001) in the rPre-C group, and 100% (P < 0.001) in the rHCC group, respectively. Also, there were significant differences of liver Wnt3a (P < 0.001) or serum Wnt3a (P < 0.001) among different groups. CONCLUSIONS: Overexpression of Wnt3a was associated with rat hepatocarcinogenesis and it should be expected to be a promising monitoring biomarker for HCC occurrence at early stage.


Asunto(s)
Carcinogénesis , Carcinoma Hepatocelular , Neoplasias Hepáticas , Proteína Wnt3A , Animales , Ratas , Biomarcadores de Tumor/metabolismo , Carcinogénesis/genética , Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/patología , Ratas Sprague-Dawley , ARN Mensajero/metabolismo , Vía de Señalización Wnt , Proteína Wnt3A/análisis
13.
Molecules ; 28(19)2023 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-37836829

RESUMEN

Transition metal alloys have emerged as promising electrocatalysts due to their ability to modulate key parameters, such as d-band electron filling, Fermi level energy, and interatomic spacing, thereby influencing their affinity towards reaction intermediates. However, the structural stability of alloy electrocatalysts during the alkaline hydrogen evolution reaction (HER) remains a subject of debate. In this study, we systematically investigated the structural evolution and catalytic activity of the c-Co/Co3Mo electrocatalyst under alkaline HER conditions. Our findings reveal that the Co3Mo alloy and H0.9MoO3 exhibit instability during alkaline HER, leading to the breakdown of the crystal structure. As a result, the cubic phase c-Co undergoes a conversion to the hexagonal phase h-Co, which exhibits strong catalytic activity. Additionally, we identified hexagonal phase Co(OH)2 as an intermediate product of this conversion process. Furthermore, we explored the readsorption and surface coordination of the Mo element, which contribute to the enhanced catalytic activity of the c-Co/Co3Mo catalyst in alkaline HER. This work provides valuable insights into the dynamic behavior of alloy-based electrocatalysts, shedding light on their structural stability and catalytic activity during electrochemical reduction processes.

14.
J Environ Sci Health B ; 58(2): 131-138, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36727586

RESUMEN

Agrilus planipennis Fairmaire is an important wood boring pest of Fraxinus species in the family Oleaceae. Oxacyclotridecan-2-one is an attractant of A. planipennis. Traps with attractive lures can be used in mass trapping of insect pests, but the traps are a bit expensive and they must be set up and dismantled in the field. To develop an attract and kill method for A. planipennis, we enveloped oxacyclotridecan-2-one into sustained-released microspheres. The attractant microspheres were prepared using the solvent evaporation method. An orthogonal test L16(45) was used to optimize the five preparation factors: the quantities of polylactic acid (PLA), gelatin, Polyvinyl alcohol (PVA), attractant, and the rotational speed. The results showed that optimal conditions for preparation of microspheres were 2.5 g PLA, 0.5 g gelatin, 1.25 g PVA, 2 mL attractant and 600 r min-1 rotational speed. The encapsulation efficiency of the prepared microspheres was 95.22%, and the attractant loading rate was 15.61%. The release rate of attractant from prepared microspheres was about 26.74% on the first day, and then gradually entered a sustained-release stage for about 10 days that lasted for 17 days. Preliminary field control experiments showed that the prepared microspheres could attract and kill A. planipennis adults when sprayed together with insecticide.


Asunto(s)
Escarabajos , Insecticidas , Animales , Larva , Gelatina , Microesferas , Insecticidas/farmacología
15.
Omega ; 119: 102875, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37009427

RESUMEN

With the rapid development of telemedicine and the impact of the COVID-19 pandemic, more and more patients are now resorting to using telemedicine channels for healthcare services. However, for hospitals, there exists a lack of managerial guidance in place to help them adopt telemedicine in a practical and standardized way. This study considers a hospital operating with both telemedicine (virtual) and face-to-face (physical) medical channels, and which allocates its capacity by also taking into account the possibility of both referrals and misdiagnosis. Methodologically, we construct a game model based on a queuing framework. We first analyze equilibrium strategies for patient arrivals. Then we propose the necessary conditions for a hospital to develop a telemedicine channel and to operate both channels simultaneously. Finally, we find the optimal decisions for the service level of telemedicine, which can also be regarded as the optimal proportion of diseases treated by telemedicine, and the optimal hospital capacity allocation ratio between the two channels. We also find that hospitals in a full coverage market (e.g., for certain small-scale hospitals and community hospitals or cancer hospitals) are more difficult to adopt telemedicine than hospitals in a partial coverage market (e.g., for comprehensive large-scale hospitals with many potential patients). Small-scale hospitals are more suited to operating telemedicine as a gatekeeper to help triage patients, while large hospitals are more prone to regard telemedicine as a medical channel for providing professional medical services to patients. We also analyze the effects of the telemedicine cure rate and the cost ratio of telemedicine to the physical hospital on the overall healthcare system performance, including the physical hospital arrival rate, patients' waiting time, total profit, and social welfare. Then we compare the performance, ex ante versus ex post, the implementation of telemedicine. It is shown that when the market is partially covered, the total social welfare is always higher than it was before the implementation. However, as far as the profit goes, if the telemedicine cure rate is low and the cost ratio is high, the total hospital profit may be lower than it was prior to using telemedicine. However, the profit and social welfare of hospitals in the full coverage market are always lower than it was before the implementation. In addition, the waiting time in the hospital is always higher than that before the implementation, which means that the implementation of telemedicine will make patients who must receive treatment in the physical hospital face even worse congestion than before. More insights and results are gleaned from a series of numerical studies.

16.
Nanotechnology ; 33(44)2022 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-35878590

RESUMEN

Developing highly efficient and stable electrocatalysts for oxygen evolution reaction is of significant importance for applications in energy conversion and storage. Modulation of electronic structure of catalysts is critical for improving the performance of the resulting electrodes. Here, we report a facile way to engineer the electronic structure of Ni3FeS by coating a thin polyaniline (PANI) layer for improving electrocatalytic activity for overall water splitting. Experimental investigations unveil that the strong electronic interactions between the lone electron pairs of nitrogen in PANI and d orbitals of iron, nickel in Ni3FeS result in an electron-rich structure of Ni and Fe, and consequently optimize the adsorption and desorption processes to promote the OER activity. Remarkably, the resulting PANI/Ni3FeS electrode exhibited much enhanced OER performance with a low overpotential of 143 mV at a current density of 10 mA·cm-2and good stability. Promisingly, coupled with the reported MoNi4/MoO2electrode, the two-electrode electrolyzer achieved a current density of 10 mA·cm-2with a relatively low potential of 1.55 V, and can generate oxygen and hydrogen bubbles steadily driven by a commercial dry battery, endowed the composite electrocatalyst with high potential for practical applications.

17.
Nanotechnology ; 33(15)2022 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-34972094

RESUMEN

The electronic structure of active sites is of importance for catalysts to achieve an optimized interaction with the intermediates. In this study, a unique organic-inorganic hybrid oxygen evolution reaction electrocatalyst composed of electrochemically inactive conducting polyaniline (PANI) and non-precious Fe-based oxide Fe3O4is presented. PANI molecules werein situloaded on Fe3O4nanoparticles through an efficient and simple process under mild conditions. The electronic structure of Fe3O4was modulated by creating a strong interaction with PANI molecules, leading to enhanced activity and stability of the catalyst to achieve 10 mA cm-2geometrical current density at overpotential of 265 mV in 1 M aqueous KOH solution. This work demonstrates that a highly efficient electrocatalyst can be achieved by molecular modification and provides a novel strategy for the optimization of the inactive non-precious catalysts.

18.
Molecules ; 27(11)2022 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-35684437

RESUMEN

Bacterial cellulose (BC) is well known as a high-performance dietary fiber. This study investigates the adsorption capacity of BC for cholesterol, sodium cholate, unsaturated oil, and heavy metal ions in vitro. Further, a hyperlipidemia mouse model was constructed to investigate the effects of BC on lipid metabolism, antioxidant levels, and intestinal microflora. The results showed that the maximum adsorption capacities of BC for cholesterol, sodium cholate, Pb2+ and Cr6+ were 11.910, 16.149, 238.337, 1.525 and 1.809 mg/g, respectively. Additionally, BC reduced the blood lipid levels, regulated the peroxide levels, and ameliorated the liver injury in hyperlipidemia mice. Analysis of the intestinal flora revealed that BC improved the bacterial community of intestinal microflora in hyperlipidemia mice. It was found that the abundance of Bacteroidetes was increased, while the abundance of Firmicutes and Proteobacteria was decreased at the phylum level. In addition, increased abundance of Lactobacillus and decreased abundance of Lachnospiraceae and Prevotellaceae were obtained at the genus level. These changes were supposed to be beneficial to the activities of intestinal microflora. To conclude, the findings prove the role of BC in improving lipid metabolism in hyperlipidemia mice and provide a theoretical basis for the utilization of BC in functional food.


Asunto(s)
Hiperlipidemias , Metabolismo de los Lípidos , Animales , Bacterias , Bacteroidetes , Celulosa/farmacología , Colesterol , Hiperlipidemias/tratamiento farmacológico , Ratones , Colato de Sodio
19.
Molecules ; 27(21)2022 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-36364265

RESUMEN

Rational design and constructing earth-abundant electrocatalysts for efficient electrocatalytic water splitting is a crucial challenge. Herein, we report a simple and efficient one-step electrochemical synthetic route of the NiFe2O4@FeOOH composite electrocatalyst for the oxygen evolution reaction. The unique morphology of the NiFe2O4 nanoflowers loaded on FeOOH nanosheets allows more active sites to be exposed and promote charge transfer as well as gas release, and the resulting electrode enables a current density of 10 mA cm-2 at a low overpotential of 255 mV with outstanding stability at a current density of 100 mA cm-2 for 300 h.

20.
Sheng Li Xue Bao ; 74(2): 135-144, 2022 Apr 25.
Artículo en Zh | MEDLINE | ID: mdl-35503061

RESUMEN

Vestibular compensation is an important model for developing the prevention and intervention strategies of vestibular disorders, and investigating the plasticity of the adult central nervous system induced by peripheral injury. Medial vestibular nucleus (MVN) in brainstem is critical center for vestibular compensation. Its neuronal excitability and sensitivity have been implicated in normal function of vestibular system. Previous studies mainly focused on the changes in neuronal excitability of the MVN in lesional side of the rat model of vestibular compensation following the unilateral labyrinthectomy (UL). However, the plasticity of sensitivity of bilateral MVN neurons dynamically responding to input stimuli is still largely unknown. In the present study, by using qPCR, whole-cell patch clamp recording in acute brain slices and behavioral techniques, we observed that 6 h after UL, rats showed a significant deficit in spontaneous locomotion, and a decrease in excitability of type B neurons in the ipsilesional rather than contralesional MVN. By contrast, type B neurons in the contralesional rather than ipsilesional MVN exhibited an increase in response sensitivity to the ramp and step input current stimuli. One week after UL, both the neuronal excitability of the ipsilesional MVN and the neuronal sensitivity of the contralesional MVN recovered to the baseline, accompanied by a compensation of spontaneous locomotion. In addition, the data showed that the small conductance Ca2+-activated K+ (SK) channel involved in the regulation of type B MVN neuronal sensitivity, showed a selective decrease in expression in the contralesional MVN 6 h after UL, and returned to normal level 1 week later. Pharmacological blockage of SK channel in contralateral MVN to inhibit the UL-induced functional plasticity of SK channel significantly delayed the compensation of vestibular motor dysfunction. These results suggest that the changes in plasticity of the ipsilesional MVN neuronal excitability, together with changes in the contralesional MVN neuronal sensitivity, may both contribute to the development of vestibular symptoms as well as vestibular compensation, and SK channel may be an essential ionic mechanism responsible for the dynamic changes of MVN neuronal sensitivity during vestibular compensation.


Asunto(s)
Núcleos Vestibulares , Vestíbulo del Laberinto , Animales , Locomoción , Neuronas/fisiología , Técnicas de Placa-Clamp , Ratas , Núcleos Vestibulares/metabolismo
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