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1.
J Phys Chem A ; 128(27): 5243-5252, 2024 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-38937149

RESUMEN

Direct methanol fuel cells (DMFCs) have attracted increasing attention as a very promising and important energy source. In this paper, density functional theory (DFT) is used to study the structure and O-H fracture mechanism of methanol adsorption on PtnCu4-n (111) (n = 1, 2, 3) binary metal catalyst surfaces under different coverages. By comparing the adsorption energy and dehydrogenation energy barriers of methanol, it is found that the adsorption strength and dehydrogenation energy barriers of methanol on Pt and Cu sites decreased with increasing coverage. At the same Pt and Cu ratio, methanol is more easily adsorbed on Cu sites. When Pt/Cu = 3:1 and 1:3, the PtCu binary catalyst has a significant impact on the energy barrier of breaking the O-H bond in methanol with the increase of coverage. Especially when Pt/Cu = 1:3 and the coverage is 1/4 ML, the energy barriers of O-H bond breaking in methanol on Pt and Cu sites are 0.63 and 0.61 eV, respectively, which are lower than that on pure Pt. It means that the Cu sites played a very important role in reducing the O-H fracture energy barrier of methanol. When Pt/Cu = 1:1, the change in the dehydrogenation energy barrier of methanol on Pt sites and Cu sites is not significant, indicating that the coverage has little effect on it.

2.
Acta Pharmacol Sin ; 2024 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-39223366

RESUMEN

Inhibin beta A (INHBA) and its homodimer activin A have pleiotropic effects on modulation of immune responses and tumor progression, but it remains uncertain whether tumors may release activin A to regulate anti-tumor immunity. In this study we investigated the effects and mechanisms of tumor intrinsic INHBA on carcinogenesis, tumor immunity and PD-L1 blockade. Bioinformatic analysis on the TCGA database revealed that INHBA expression levels were elevated in 33 cancer types, including breast cancer (BRCA) and colon adenocarcinoma (COAD). In addition, survival analysis also corroborated that INHBA expression was negatively correlated with the prognosis of many types of cancer patients. We demonstrated that gain or loss function of Inhba did not alter in vitro growth of colorectal cancer CT26 cells, but had striking impact on mouse tumor models including CT26, MC38, B16 and 4T1 models. By using the TIMER 2.0 tool, we figured out that in most cancer types, Inhba expression in tumors was inversely associated with the infiltration of CD4+ T and CD8+ T cells. In CT26 tumor-bearing mice, overexpression of tumor INHBA eliminated the anti-tumor effect of the PD-L1 antibody atezolizumab, whereas INHBA deficiency enhanced the efficacy of atezolizumab. We revealed that tumor INHBA significantly downregulated the interferon-γ (IFN-γ) signaling pathway. Tumor INHBA overexpression led to lower expression of PD-L1 induced by IFN-γ, resulting in poor responsiveness to anti-PD-L1 treatment. On the other hand, decreased secretion of IFN-γ-stimulated chemokines, including C-X-C motif chemokine 9 (CXCL9) and 10 (CXCL10), impaired the infiltration of effector T cells into the tumor microenvironment (TME). Furthermore, the activin A-specific antibody garetosmab improved anti-tumor immunity and its combination with the anti-PD-L1 antibody atezolizumab showed a superior therapeutic effect to monotherapy with garetosmab or atezolizumab. We demonstrate that INHBA and activin A are involved in anti-tumor immunity by inhibiting the IFN-γ signaling pathway, which can be considered as potential targets to improve the responsive rate of PD-1/PD-L1 blockade.

3.
Small ; 18(24): e2201934, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35561065

RESUMEN

Due to their characteristics of high capacity and appropriate potassiation/depotassiation potential, Sb-based materials have become a class of promising anode materials for potassium ion batteries (PIBs). However, the huge strain induced by potassiation/depotassiation limits their ability to periodically accept/release K+ . Herein, a composite with FeSb2 nanoparticles embedded in a 3D porous carbon framework (FeSb2 @3DPC) is successfully constructed as an extremely stable anode material for PIBs. Benefiting from the synergistic effect of the design of nano and porous structures, the introduction of the inactive metal Fe, the firm anchoring of the FeSb2 nanoparticles by the carbon material, and the incomplete reaction of the FeSb2 , the FeSb2 @3DPC can achieve an ultra-long cycle life of over 4000 cycles at a current density of 500 mA g-1 . Furthermore, ex situ X-ray diffraction and transmission electron microscopy reveal a gradual activation process of FeSb2 for potassium storage. Fortunately, after activation, the electrochemical polarization of the FeSb2 @3DPC anode gradually alleviates and the capacitance-controlled charge storage mode further dominates compared with the diffusion-controlled mode, all of which promote the FeSb2 @3DPC to maintain the stable potassium storage capability.

4.
Small ; 18(44): e2204045, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36047969

RESUMEN

Bismuth (Bi)-based materials have attracted great attention as anodes in potassium ion batteries (PIBs) for their high theoretical capacity and suitable voltage range. Herein, the authors report a unique spindle-like structured Bi@N-doped carbon composite (SPB@NC) consisting of interconnected nano-Bi coated heteroatom-doped hard carbon layer via an interesting in situ carbon thermal reduction method. The special interconnected Bi nanoparticles gradually form porous structure with ample inner voids for accommodating volume variations while the N-doped carbon layer not only keeps the electrode stable, but also contributes to rapid electron/ion transfer. As a result, such a robust framework endows SPB@NC fast potassium storage with outstanding capacity of 276.5 mAh g-1  at 30 A g-1 (i.e., 1 min for discharge/charge) and durable cycling performance of 299.3 mAh g-1  at 5 A g-1  after 2000 cycles. Notably, a full cell assembled with potassium vanadate cathode is promising for practical applications. A series of ex situ techniques reveals the in-depth potassium storage mechanism and kinetics reactions. This work illuminates helpful insights into Bi-based anodes for PIBs.

5.
Neuroendocrinology ; 112(6): 555-570, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34348334

RESUMEN

BACKGROUND/AIM: Central administration of cocaine- and amphetamine-regulated transcript peptides (CARTp) alters gastrointestinal motility and reduces food intake in rats. Since neurons in the dorsal motor nucleus of the vagus (DMV) receive GABAergic and glutamatergic inputs and innervate the smooth muscle of gastrointestinal organs, we hypothesized that CARTp acts on the DMV or presynaptic neurons. METHODS: We used 3,3'-dioctadecyloxa-carbocyanine perchlorate (DiO) retrograde tracing with electrophysiological methods to record DMV neurons innervating the stomach antrum or cecum in brainstem slices from adult rats. RESULTS: DiO application did not change the electrophysiological properties of DMV neurons. CART55-102 had no effect on the basal firing rates of neurons in either the stomach antrum-labeled group (SLG) or cecum-labeled group (CLG). When presynaptic inputs were blocked, CART55-102 further increased the firing rates of the SLG, suggesting a direct excitatory effect. Spontaneous inhibitory postsynaptic currents (sIPSCs) occurred at a higher frequency in SLG neurons than in CLG neurons. CART55-102 reduced the amplitude and the frequency of sIPSCs in SLG neurons dose-dependently, with higher doses also reducing spontaneous excitatory postsynaptic currents (sEPSCs). Higher doses of CART55-102 reduced sIPSC and sEPSC amplitudes in CLG neurons, suggesting a postsynaptic effect. In response to incremental current injections, the SLG neurons exhibited less increases in firing activity. Simultaneous applications of current injections and CART55-102 decreased the firing activity of the CLG. Therefore, stomach antrum-projecting DMV neurons possess a higher gating ability to stabilize firing activity. CONCLUSION: The mechanism by which CARTp mediates anorectic actions may be through a direct reduction in cecum-projecting DMV neuron excitability and, to a lesser extent, that of antrum-projecting DMV neurons, by acting on receptors of these neurons.


Asunto(s)
Ciego , Neuronas , Animales , Ciego/inervación , Masculino , Proteínas del Tejido Nervioso , Ratas , Ratas Sprague-Dawley , Estómago/inervación , Estómago/fisiología
6.
BMC Pregnancy Childbirth ; 21(1): 585, 2021 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-34429082

RESUMEN

BACKGROUND: The prenatal test of cell-free fetal DNA (cffDNA) is also known as noninvasive prenatal testing (NIPT) with high sensitivity and specificity. This study is to evaluate the performance of NIPT and its clinical relevance with various clinical indications. METHODS: A retrospective analysis was conducted on 14,316 pregnant women with prenatal indications, including advanced maternal age (≥35 years), maternal serum screening abnormalities, the thickened nuchal translucency (≥2.5 mm) and other ultrasound abnormalities, twin pregnancy/IVF-ET pregnancy, etc. The whole-genome sequencing (WGS) of maternal plasma cffDNA was employed in this study. RESULTS: A total of 189 (1.32%) positive NIPT cases were identified, and 113/189 (59.79%)cases were confirmed by invasive prenatal testing. Abnormal serological screening (53.14%) was the most common indication, followed by elderly pregnancy (23.02%). The positive prediction value for T21, T18, T13, sex chromosome abnormalities, other autosomal aneuploidy abnormalities, and CNV abnormalities were 91.84, 68.75,37.50, 66.67, 14.29, and 6.45%, respectively. The positive rate and the true positive rate of nuchal translucency (NT) thickening were the highest (4.17 and 3.33%), followed by the voluntary requirement group (3.49 and 1.90%) in the various prenatal screening indications. The cffDNA concentration was linearly correlated with gestational age (≥10 weeks) and the positive NIPT group's Z-score values. CONCLUSIONS: whole-genome sequencing of cffDNA has extremely high sensitivity and specificity for T21, high sensitivity for T18, sex chromosome abnormalities, and T13. It also provides evidence for other abnormal chromosomal karyotypes (CNV and non-21/18/13 autosomal aneuploidy abnormalities). The cffDNA concentration is closely related to the gestational age and determines the specificity of NIPT. Our results highlight NIPT's clinical significance, which is an effective prenatal screening tool for high-quality care of pregnancy.


Asunto(s)
Aberraciones Cromosómicas/embriología , Trastornos de los Cromosomas/diagnóstico , Pruebas Prenatales no Invasivas , Embarazo de Alto Riesgo , Adolescente , Adulto , China/epidemiología , Femenino , Humanos , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Embarazo , Estudios Retrospectivos , Sensibilidad y Especificidad , Secuenciación Completa del Genoma , Adulto Joven
7.
Clin Infect Dis ; 71(16): 2158-2166, 2020 11 19.
Artículo en Inglés | MEDLINE | ID: mdl-32445580

RESUMEN

BACKGROUND: In December 2019, the coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) broke out in Wuhan. Epidemiological and clinical characteristics of patients with COVID-19 have been reported, but the relationships between laboratory features and viral load has not been comprehensively described. METHODS: Adult inpatients (≥18 years old) with COVID-19 who underwent multiple (≥5 times) nucleic acid tests with nasal and pharyngeal swabs were recruited from Renmin Hospital of Wuhan University, including general patients (n = 70), severe patients (n = 195), and critical patients (n = 43). Laboratory data, demographic data, and clinical data were extracted from electronic medical records. The fitted polynomial curve was used to explore the association between serial viral loads and illness severity. RESULTS: Viral load of SARS-CoV-2 peaked within the first few days (2-4 days) after admission, then decreased rapidly along with virus rebound under treatment. Critical patients had the highest viral loads, in contrast to the general patients showing the lowest viral loads. The viral loads were higher in sputum compared with nasal and pharyngeal swab (P = .026). The positive rate of respiratory tract samples was significantly higher than that of gastrointestinal tract samples (P < .001). The SARS-CoV-2 viral load was negatively correlated with portion parameters of blood routine and lymphocyte subsets and was positively associated with laboratory features of cardiovascular system. CONCLUSIONS: The serial viral loads of patients revealed whole viral shedding during hospitalization and the resurgence of virus during the treatment, which could be used for early warning of illness severity, thus improve antiviral interventions.


Asunto(s)
COVID-19/epidemiología , Coronavirus/patogenicidad , China/epidemiología , Femenino , Humanos , Masculino , Pruebas Serológicas , Carga Viral
8.
Biochem Biophys Res Commun ; 533(4): 1366-1370, 2020 12 17.
Artículo en Inglés | MEDLINE | ID: mdl-33097185

RESUMEN

Nematode Caenorhabditis elegans (C. elegans) exhibited a vigorous swimming behavior in liquid medium. Addition of dopamine inhibited the swimming behavior, causing paralysis in 65% of wild-type nematodes. Interestingly, phytocannabinoids cannabidiol (CBD) or cannabidivarin (CBDV), caused paralysis in 40% of the animals. Knockout of DOP-3, the dopamine D2-like receptor critical for locomotor behavior, eliminated the paralysis induced by dopamine, CBD, and CBDV. In contrast, both CBD and CBDV caused paralysis in animals lacking CAT-2, an enzyme necessary for dopamine synthesis. Co-administration of dopamine with either CBD or CBDV caused paralysis similar to that of either phytocannabinoid treatment alone. These data support the notion that CBD and CBDV act as functional partial agonists on dopamine D2-like receptors in vivo. The discovery that dopamine receptor is involved in the actions of phytocannabinoids moves a significant step toward our understanding of the mechanisms for medical uses of cannabis in the treatment of neurological and psychiatric disorders.


Asunto(s)
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/efectos de los fármacos , Cannabidiol/farmacología , Cannabinoides/farmacología , Receptores de Dopamina D2/metabolismo , Animales , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Dopamina/metabolismo , Dopamina/farmacología , Oxigenasas de Función Mixta/genética , Oxigenasas de Función Mixta/metabolismo , Mutación , Parálisis/inducido químicamente , Psicotrópicos/farmacología , Receptores de Dopamina D2/genética
9.
Cancer Cell Int ; 20: 313, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32694935

RESUMEN

BACKGROUND: The aim of this study was to investigate the association between telomerase reverse transcriptase (TERT) gene polymorphisms and acute myeloid leukemia (AML) susceptibility in a Chinese Han population. METHODS: A total of 102 AML patients and 108 healthy controls were enrolled in this case-control study. TERT gene rs2853669 and rs2736100 polymorphisms were genotyped via polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Chi-square test was applied to compare polymorphism distributions between case and control groups. The strength of the association between TERT gene polymorphisms and AML susceptibility was evaluated utilizing odds ratio (OR) with corresponding 95% confidence interval (CI). RESULTS: CC genotype and C allele of rs2736100 polymorphism were more frequent in AML patients (P < 0.05), and individuals carrying CC genotype showed higher risk of suffering from AML (OR = 2.632, 95% CI 1.129-6.133). But for rs2853669 polymorphism, no significant differences were detected in either genotype or allele distributions between groups (P > 0.05). CONCLUSIONS: This study suggested a positive association between TERT gene rs2736100 polymorphism and AML susceptibility in Chinese Han population.

10.
JAMA ; 323(15): 1488-1494, 2020 04 21.
Artículo en Inglés | MEDLINE | ID: mdl-32125362

RESUMEN

Importance: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan, China, in December 2019 and has spread globally with sustained human-to-human transmission outside China. Objective: To report the initial experience in Singapore with the epidemiologic investigation of this outbreak, clinical features, and management. Design, Setting, and Participants: Descriptive case series of the first 18 patients diagnosed with polymerase chain reaction (PCR)-confirmed SARS-CoV-2 infection at 4 hospitals in Singapore from January 23 to February 3, 2020; final follow-up date was February 25, 2020. Exposures: Confirmed SARS-CoV-2 infection. Main Outcomes and Measures: Clinical, laboratory, and radiologic data were collected, including PCR cycle threshold values from nasopharyngeal swabs and viral shedding in blood, urine, and stool. Clinical course was summarized, including requirement for supplemental oxygen and intensive care and use of empirical treatment with lopinavir-ritonavir. Results: Among the 18 hospitalized patients with PCR-confirmed SARS-CoV-2 infection (median age, 47 years; 9 [50%] women), clinical presentation was an upper respiratory tract infection in 12 (67%), and viral shedding from the nasopharynx was prolonged for 7 days or longer among 15 (83%). Six individuals (33%) required supplemental oxygen; of these, 2 required intensive care. There were no deaths. Virus was detectable in the stool (4/8 [50%]) and blood (1/12 [8%]) by PCR but not in urine. Five individuals requiring supplemental oxygen were treated with lopinavir-ritonavir. For 3 of the 5 patients, fever resolved and supplemental oxygen requirement was reduced within 3 days, whereas 2 deteriorated with progressive respiratory failure. Four of the 5 patients treated with lopinavir-ritonavir developed nausea, vomiting, and/or diarrhea, and 3 developed abnormal liver function test results. Conclusions and Relevance: Among the first 18 patients diagnosed with SARS-CoV-2 infection in Singapore, clinical presentation was frequently a mild respiratory tract infection. Some patients required supplemental oxygen and had variable clinical outcomes following treatment with an antiretroviral agent.


Asunto(s)
Betacoronavirus/aislamiento & purificación , Infecciones por Coronavirus , Pandemias , Neumonía Viral , Adulto , Anciano , Antivirales/uso terapéutico , COVID-19 , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/terapia , Infecciones por Coronavirus/virología , Progresión de la Enfermedad , Combinación de Medicamentos , Femenino , Humanos , Lopinavir/efectos adversos , Lopinavir/uso terapéutico , Masculino , Persona de Mediana Edad , Terapia por Inhalación de Oxígeno , Neumonía Viral/epidemiología , Neumonía Viral/terapia , Neumonía Viral/virología , Reacción en Cadena de la Polimerasa , Infecciones del Sistema Respiratorio/virología , Ritonavir/efectos adversos , Ritonavir/uso terapéutico , SARS-CoV-2 , Singapur/epidemiología , Esparcimiento de Virus
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