Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 38
Filtrar
1.
FASEB J ; 37(1): e22716, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36527390

RESUMO

Non-alcoholic fatty liver disease (NAFLD) is a major health problem in Western countries and has become the most common cause of chronic liver disease. Although NAFLD is closely associated with obesity, inflammation, and insulin resistance, its pathogenesis remains unclear. The disease begins with excessive accumulation of triglycerides in the liver, which in turn leads to liver cell damage, steatosis, inflammation, and so on. P38γ is one of the four isoforms of P38 mitogen-activated protein kinases (P38 MAPKs) that contributes to inflammation in different diseases. In this research, we investigated the role of P38γ in NAFLD. In vivo, a NAFLD model was established by feeding C57BL/6J mice with a methionine- and choline-deficient (MCD) diet and adeno-associated virus (AAV9-shRNA-P38γ) was injected into C57BL/6J mice by tail vein for knockdown P38γ. The results indicated that the expression level of P38γ was upregulated in MCD-fed mice. Furthermore, the downregulation of P38γ significantly attenuated liver injury and lipid accumulation in mice. In vitro, mouse hepatocytes AML-12 were treated with free fatty acid (FFA). We found that P38γ was obviously increased in FFA-treated AML-12 cells, whereas knockdown of P38γ significantly suppressed lipid accumulation in FFA-treated AML-12 cells. Furthermore, P38γ regulated the Janus Kinase-Signal transducers and activators of transcription (JAK-STAT) signaling pathway. Inhibition of P38γ can inhibit the JAK-STAT signaling pathway, thereby inhibiting lipid accumulation in FFA-treated AML-12 cells. In conclusion, our results suggest that targeting P38γ contributes to the suppression of lipid accumulation in fatty liver disease.


Assuntos
Leucemia Mieloide Aguda , Hepatopatia Gordurosa não Alcoólica , Camundongos , Animais , Hepatopatia Gordurosa não Alcoólica/metabolismo , Metabolismo dos Lipídeos , Janus Quinases/metabolismo , Dieta Hiperlipídica , Camundongos Endogâmicos C57BL , Fígado/metabolismo , Transdução de Sinais , Ácidos Graxos não Esterificados/metabolismo , Inflamação/metabolismo , Metionina/farmacologia , Metionina/metabolismo , Leucemia Mieloide Aguda/metabolismo
2.
Inorg Chem ; 62(5): 2153-2160, 2023 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-36693191

RESUMO

Metal dodecaborates (MxB12H12) are a versatile class of materials used in polymer chemistry and cancer treatment and are promising candidates as electrolytes for solid-state batteries. However, a general and scalable approach has not yet been developed for producing high-purity B12H122- derivatives. In this work, we report a simple, efficient, and environmentally benign solvothermal method to prepare diffraction and 11B NMR pure Na2B12H12 (85% yield) and K2B12H12 (84% yield). This new synthetic approach is based on the use of the borane dimethyl sulfide complex (DMS·BH3) and borohydrides (NaBH4, KBH4) heated at different temperatures in diglyme in an autoclave. It was found that high-purity Na2B12H12·diglyme solvate is obtained via an intermediate formation of B3H8-, B9H14-, and B11H14-, which are all soluble in diglyme. Heating under vacuum is shown to be efficient for removing the coordinated diglyme, allowing the formation of unsolvated Na2B12H12. Autoclave synthesis starting from KBH4 directly yields solvent-free K2B12H12, and ball-milling KBH4 prior to the synthesis enabling us to significantly improve the final yield. The new synthetic method paves the way for large-scale synthesis of MxB12H12 derivatives, enabling to envisage a wider scope of practical applications.

3.
Proc Natl Acad Sci U S A ; 115(10): 2508-2513, 2018 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-29463705

RESUMO

Neuregulin3 (NRG3) is a growth factor of the neuregulin (NRG) family and a risk gene of various severe mental illnesses including schizophrenia, bipolar disorders, and major depression. However, the physiological function of NRG3 remains poorly understood. Here we show that loss of Nrg3 in GFAP-Nrg3f/f mice increased glutamatergic transmission, but had no effect on GABAergic transmission. These phenotypes were observed in Nex-Nrg3f/f mice, where Nrg3 was specifically knocked out in pyramidal neurons, indicating that Nrg3 regulates glutamatergic transmission by a cell-autonomous mechanism. Consequently, in the absence of Nrg3 in pyramidal neurons, mutant mice displayed various behavioral deficits related to mental illnesses. We show that the Nrg3 mutation decreased paired-pulse facilitation, increased decay of NMDAR currents when treated with MK801, and increased minimal stimulation-elicited response, providing evidence that the Nrg3 mutation increases glutamate release probability. Notably, Nrg3 is a presynaptic protein that regulates the SNARE-complex assembly. Finally, increased Nrg3 levels, as observed in patients with severe mental illnesses, suppressed glutamatergic transmission. Together, these observations indicate that, unlike the prototype Nrg1, the effect of which is mediated by activating ErbB4 in interneurons, Nrg3 is critical in controlling glutamatergic transmission by regulating the SNARE complex at the presynaptic terminals, identifying a function of Nrg3 and revealing a pathophysiological mechanism for hypofunction of the glutamatergic pathway in Nrg3-related severe mental illnesses.


Assuntos
Ácido Glutâmico/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas SNARE/metabolismo , Animais , Comportamento Animal/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/genética , Transtornos Mentais/genética , Camundongos , Camundongos Transgênicos , Neurregulinas , Células Piramidais/metabolismo
4.
Parasitol Res ; 120(5): 1627-1636, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33792812

RESUMO

Paragonimus proliferus, a lung fluke of the genus Paragonimus, was first reported in Yunnan province, China. P. proliferus can infect Sprague-Dawley (SD) rats and cause lung damage, but there is still no direct evidence of human infection. Until now, there has been a lack of studies on P. proliferus parasitism and development in mammalian lung tissue. The aim of this study was to perform transcriptomic profiling of P. proliferus at different developmental stages. SD rats were infected with P. proliferus metacercariae obtained from crabs; worms isolated from the lungs at different time points as well as metacercariae were subjected to whole transcriptome sequencing. Overall, 34,403 transcripts with the total length of 33,223,828 bp, average length of 965 bp, and N50 of 1833 bp were assembled. Comparative analysis indicated that P. proliferus, similar to other Paragonimus spp., expressed genes related to catabolism, whereas P. proliferus-specific transcripts were related to the maintenance of cellular redox homeostasis, sensitivity to bacteria, and immune response. Transcriptional dynamics analysis revealed that genes involved in the regulation of catabolism and apoptosis had stable expression over the P. proliferus life cycle, whereas those involved in development and immune response showed time-dependent changes. High expression of genes associated with immune response corresponded to that of genes regulating the sensitivity to bacteria and immune protection. We constructed a P. proliferus developmental model, including the development of the body, suckers, blood cells, reproductive and tracheal systems, lymph, skin, cartilage, and other tissues and organs, and an immune response model, which mainly involved T cells and macrophages. Our study provides a foundation for further research into the molecular biology and infection mechanism of P. proliferus.


Assuntos
Pulmão/parasitologia , Paragonimíase/patologia , Paragonimus/embriologia , Paragonimus/crescimento & desenvolvimento , Animais , Braquiúros/parasitologia , China , Perfilação da Expressão Gênica , Humanos , Estágios do Ciclo de Vida , Metacercárias/crescimento & desenvolvimento , Paragonimíase/parasitologia , Paragonimus/isolamento & purificação , Ratos , Ratos Sprague-Dawley , Transcriptoma/genética
5.
Molecules ; 24(3)2019 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-30717403

RESUMO

Here we report a Ti50V50-10 wt.% C alloy with a unique lattice and microstructure for hydrogen storage development. Different from a traditionally synthesized Ti50V50 alloy prepared by a melting method and having a body-centered cubic (BCC) structure, this Ti50V50-C alloy synthesized by a mechanical alloying method is with a face-centered cubic (FCC) structure (space group: Fm-3m No. 225). The crystalline size is 60 nm. This alloy may directly absorb hydrogen near room temperature without any activation process. Mechanisms of the good kinetics from lattice and microstructure aspects were discussed. Findings reported here may indicate a new possibility in the development of future hydrogen storage materials.


Assuntos
Ligas/química , Carbono/química , Titânio/química , Vanádio/química , Hidrogênio/química , Cinética , Teste de Materiais , Propriedades de Superfície
6.
BMC Complement Altern Med ; 17(1): 315, 2017 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-28619075

RESUMO

BACKGROUND: Inflammatory bowel disease (IBD), denominated by Crohn's disease and ulcerative colitis, is often associated with abdominal pain, diarrhea and bloody stool. The standard protocols for treating colitis conditions are not satisfactory; thus, complementary and alternative medicines have been increasingly accepted by IBD sufferers worldwide. In this study, we aimed to elucidate the anti-inflammatory effect of Chang-An-Shuan (CAS), a 6-herb Chinese medicinal formula, on 2, 4, 6-trinitrobenzenesulfonic acid (TNBS)-induced colitis in rats and the underlying mechanisms. METHODS: Sprague-Dawley rats were administered with rectal gavage of 2.5% TNBS in 50% ethanol for the induction of experimental colitis which is considered as a model for Crohn's disease. Upon the TNBS induction, rats were given CAS at 0.5 g/kg/day or 5 g/kg/day for 10 days. The application of salicylazosulfapyridine (0.5 g/kg/day) was served as a positive reference drug for the colitis condition. The efficacy and mechanistic action of CAS were evaluated by means of histopathological and biochemical approaches such as histological staining, real-time polymerase chain reaction, Western blotting analysis and enzyme-linked immunosorbent assay. RESULTS: Oral administration of CAS at 5 g/kg/day, but not 0.5 g/kg/day, significantly ameliorated the severity of TNBS-induced colitis as evidenced by the reduced loss of body weight, alleviated diarrhea and decreased bloody stool. While lowering the disease activity index, the administration of CAS lessened mucosal lesions thus mucosal integrity of the colitis rats was notably improved. Further, the CAS treatment also significantly suppressed the mRNA and protein levels of pro-inflammatory cytokines, namely interleukin-1ß and tumor necrosis factor-α while enhancing the level of anti-inflammatory cytokine IL-10 in the TNBS-treated rats. Importantly, the ameliorative effect of CAS was related to an inhibition of the nuclear factor-κB (NF-κB) signaling pathway by downregulating the expression levels of NF-κBp-65, p-38 and p-AKT. CONCLUSIONS: We suggest that CAS is a potential alternative remedial approach for treating IBD conditions, and the anti-inflammatory effect of CAS is associated with the down-regulation of the NF-κB signaling pathway and the balanced production of pro- and anti-inflammatory cytokines.


Assuntos
Anti-Inflamatórios/administração & dosagem , Colite/tratamento farmacológico , Medicamentos de Ervas Chinesas/administração & dosagem , Animais , Colite/induzido quimicamente , Colite/genética , Colite/imunologia , Humanos , Interleucina-10/genética , Interleucina-10/imunologia , Interleucina-1beta/genética , Interleucina-1beta/imunologia , Masculino , NF-kappa B/genética , NF-kappa B/imunologia , Ratos , Ratos Sprague-Dawley , Ácido Trinitrobenzenossulfônico/efeitos adversos
7.
World J Gastrointest Oncol ; 16(7): 3211-3229, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39072182

RESUMO

BACKGROUND: Gastric intestinal metaplasia (IM) is a precancerous lesion that is associated with an elevated risk of gastric carcinogenesis. Weiwei Decoction (WWD) is a promising traditional Chinese herbal formula widely employed in clinical for treating IM. Previous studies suggested the potential involvement of the olfactomedin 4 (OLFM4)/nucleotide-binding oligomerization domain 1 (NOD1)/caudal-type homeobox gene 2 (CDX2) signaling pathway in IM regulation. AIM: To verify the regulation of the OLFM4/NOD1/CDX2 pathway in IM, specifically investigating WWD's effectiveness on IM through this pathway. METHODS: Immunohistochemistry for OLFM4, NOD1, and CDX2 was conducted on tissue microarray. GES-1 cells treated with chenodeoxycholic acid were utilized as IM cell models. OLFM4 short hairpin RNA (shRNA), NOD1 shRNA, and OLFM4 pcDNA were transfected to clarify the pathway regulatory relationships. Protein interactions were validated by co-immunoprecipitation. To explore WWD's pharmacological actions, IM rat models were induced using N-methyl-N'-nitro-N-nitrosoguanidine followed by WWD gavage. Gastric cells were treated with WWD-medicated serum. Cytokines and chemokines content were assessed by enzyme-linked immunosorbent assay and quantitative reverse transcription polymerase chain reaction. RESULTS: The OLFM4/NOD1/CDX2 axis was a characteristic of IM. OLFM4 exhibited direct binding and subsequent down-regulation of NOD1, thereby sustaining the activation of CDX2 and promoting the progression of IM. WWD improved gastric mucosal histological lesions while suppressing intestinal markers KLF transcription factor 4, villin 1, and MUCIN 2 expression in IM rats. Regarding pharmacological actions, WWD suppressed OLFM4 and restored NOD1 expression, consequently reducing CDX2 at the mRNA and protein levels in IM rats. Parallel regulatory mechanisms were observed at the protein level in IM cells treated with WWD-medicated serum. Furthermore, WWD-medicated serum treatment strengthened OLFM4 and NOD1 interaction. In case of anti-inflammatory, WWD restrained interleukin (IL)-6, interferon-gamma, IL-17, macrophage chemoattractant protein-1, macrophage inflammatory protein 1 alpha content in IM rat serum. WWD-medicated serum inhibited tumor necrosis factor alpha, IL-6, IL-8 transcriptions in IM cells. CONCLUSION: The OLFM4/NOD1/CDX2 pathway is involved in the regulation of IM. WWD exerts its therapeutic efficacy on IM through the pathway, additionally attenuating the inflammatory response.

8.
ACS Appl Mater Interfaces ; 15(1): 1384-1391, 2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36573849

RESUMO

Doping a catalyst can efficiently improve the hydrogen reaction kinetics of MgH2. However, the hydrogen desorption behaviors are complicated in different MgH2-catalyst systems. Here, a carbon-encapsulated nickel (Ni@C) core-shell catalyst is synthesized to improve the hydrogen storage properties of MgH2. The complicated hydrogen desorption mechanism of the MgH2-Ni@C composite is elucidated. The experimental and theoretical calculation results indicate a short-range nanoreaction effect on the hydrogen desorption behaviors of the MgH2-Ni@C composite. The Ni@C catalysts and the adjacent MgH2 form nanoreaction sites along with preferential hydrogen desorption. The new interface between the in situ formed Mg and residual MgH2 contributes to the subsequent hydrogen desorption. With the nanoreaction sites increased via adding more catalyst, the short-range nanoreaction effect is more prominent; as a comparison, the interface effect becomes weaker or even disappears. In addition, the core-shell structure catalyst shows ultrahigh structural stability and catalytic activity, even after 50 hydrogen absorption and desorption cycles. Hence, this study provides new insights into the complicated hydrogen desorption behaviors and comes up with the short-range nanoreaction effect in the MgH2-catalyst system.

9.
World J Clin Cases ; 11(16): 3714-3724, 2023 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-37383139

RESUMO

Heliobacter pylori (H. pylori), a group 1 human gastric carcinogen, is significantly associated with chronic gastritis, gastric mucosal atrophy, and gastric cancer. Approximately 20% of patients infected with H. pylori develop precancerous lesions, among which metaplasia is the most critical. Except for intestinal metaplasia (IM), which is characterized by goblet cells appearing in the stomach glands, one type of mucous cell metaplasia, spasmolytic polypeptide-expressing metaplasia (SPEM), has attracted much attention. Epidemiological and clinicopathological studies suggest that SPEM may be more strongly linked to gastric adenocarcinoma than IM. SPEM, characterized by abnormal expression of trefoil factor 2, mucin 6, and Griffonia simplicifolia lectin II in the deep glands of the stomach, is caused by acute injury or inflammation. Although it is generally believed that the loss of parietal cells alone is a sufficient and direct cause of SPEM, further in-depth studies have revealed the critical role of immunosignals. There is controversy regarding whether SPEM cells originate from the transdifferentiation of mature chief cells or professional progenitors. SPEM plays a functional role in the repair of gastric epithelial injury. However, chronic inflammation and immune responses caused by H. pylori infection can induce further progression of SPEM to IM, dysplasia, and adenocarcinoma. SPEM cells upregulate the expression of whey acidic protein 4-disulfide core domain protein 2 and CD44 variant 9, which recruit M2 macrophages to the wound. Studies have revealed that interleukin-33, the most significantly upregulated cytokine in macrophages, promotes SPEM toward more advanced metaplasia. Overall, more effort is needed to reveal the specific mechanism of SPEM malignant progression driven by H. pylori infection.

10.
Dalton Trans ; 52(8): 2404-2411, 2023 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-36723231

RESUMO

A highly complex crystal structure of stoichiometric Mg5(en)6(BH4)10 was solved from single crystal synchrotron X-ray diffraction and confirmed by neutron powder diffraction (NPD) on isotopically substituted Mg(en)1.2(11BD4)2. We highlight the role of the amorphous Mg(BH4)2 in the reactivity of the Mg(BH4)2-en system and characterized a previously overlooked phase, Mg(en)2(BH4)2.

11.
Phys Chem Chem Phys ; 14(18): 6514-9, 2012 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-22456532

RESUMO

The decomposition pathway is crucial for the applicability of LiBH(4) as a hydrogen storage material. We discuss and compare the different decomposition pathways of LiBH(4) according to the thermodynamic parameters and show the experimental ways to realize them. Two pathways, i.e. the direct decomposition into boron and the decomposition via Li(2)B(12)H(12), were realized under appropriate conditions, respectively. By applying a H(2) pressure of 50 bar at 873 K or 10 bar at 700 K, LiBH(4) is forced to decompose into Li(2)B(12)H(12). In a lower pressure range of 0.1 to 10 bar at 873 K and 800 K, the concurrence of both decomposition pathways is observed. Raman spectroscopy and (11)B MAS NMR measurements confirm the formation of an intermediate Li(2)B(12)H(12) phase (mostly Li(2)B(12)H(12) adducts, such as dimers or trimers) and amorphous boron.

12.
Dalton Trans ; 50(42): 15352-15358, 2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34642725

RESUMO

Confinement of LiBH4 in porous materials is an efficient route to enhance the ionic conductivity of lithium, which seems to be associated with various types of scaffolding and its mixture ratios. In the present work, we reveal the effect of supports on ionic conductivity improvements based on a comparison of different silica supports, including micro-SiO2 (SM), porous nano-SiO2 (MSN), and nano-SiO2 with nanochannels (SBA-15). All LiBH4/silica composites exhibited higher lithium ionic conductivity, where LiBH4/SBA-15 (47% weight ratio) exhibited the highest conductivity of 3 × 10-5 S cm-1 at 35 °C, nearly three orders of magnitude higher than that of pure LiBH4. In addition, the LiBH4/SBA-15 composite has a wider electrochemical stability window of -0.2 to 5 V, satisfactory compatibility with the Li anode, and no occurrence of side reactions. These ionic conductivity enhancements can be attributed to the support effects of distinct SiO2, i.e., the increase in surface area for superior interfacial ionic conductivity and/or the increased disorder of LiBH4 for faster matrix ionic conductivity. The present study offers useful insights for designing a new hydride solid electrolyte for all-solid-state lithium ion batteries.

13.
Dalton Trans ; 50(1): 252-261, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33295901

RESUMO

Bismuth (Bi) has recently been discovered as a potential lithium-ion anode material for batteries with high Li capacity and suitable equilibrium potential, and without dendrite formation. However, the reversible electrochemical stability remains insufficient for applications. Herein, it is demonstrated that two-dimensional free-standing Bi nanosheets (Bi-NSs) have superior anode performance using either liquid or solid electrolytes. The Bi-NSs with a uniform thickness of ∼40 nm prepared by aqueous methods exhibit a record high capacity of ∼287 mA h g-1 at a current density of 250 mA g-1 with the LiBH4 solid electrolyte even after 100 cycles. Fast and stable solid-state lithium plating and stripping occur without side reactions. The 2D layered nanostructure has more active sites and a shorter diffusion length, and forms stable interfaces with the electrolyte. The present work reveals a facile synthesis route of novel 2D materials and paves an efficient pathway for high-capacity and safe bismuth-based anodes for lithium batteries.

14.
Front Pharmacol ; 12: 727956, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34675805

RESUMO

A member of the interleukin (IL)-1 superfamily was IL-36, which contained IL-36α, IL-36ß, IL-36γ, and IL-36Ra. Heterotrimer complexes, consisting of heterodimeric receptor complexes and IL-36 agonist, gave signals through intracellular functional domains, so as to bind to downstream proteins and induce inflammatory response. IL-36 agonists upregulated mature-associated CD80, CD86, MHCII, and inductively produced several pro-inflammatory cytokines through the IL-36R-dependent manner in dendritic cells (DCs). Besides, DCs had the ability to initiate the differentiation of helper T (Th) cells. Up to date, the role of IL-36 in immunity, inflammation and other diseases is of great importance. Additionally, autoimmune diseases were characterized by excessive immune response, resulting in damage and dysfunction of specific or multiple organs and tissues. Most autoimmune diseases were related to inflammatory response. In this review, we will conclude the recent research advances of IL-36 in the occurrence and development of autoimmune diseases, which may provide new insight for the future research and the treatment of these diseases.

15.
Research (Wash D C) ; 2021: 9819176, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34993488

RESUMO

Sodium alanate (NaAlH4) with 5.6 wt% of hydrogen capacity suffers seriously from the sluggish kinetics for reversible hydrogen storage. Ti-based dopants such as TiCl4, TiCl3, TiF3, and TiO2 are prominent in enhancing the dehydrogenation kinetics and hence reducing the operation temperature. The tradeoff, however, is a considerable decrease of the reversible hydrogen capacity, which largely lowers the practical value of NaAlH4. Here, we successfully synthesized a new Ti-dopant, i.e., TiH2 as nanoplates with ~50 nm in lateral size and ~15 nm in thickness by an ultrasound-driven metathesis reaction between TiCl4 and LiH in THF with graphene as supports (denoted as NP-TiH2@G). Doping of 7 wt% NP-TiH2@G enables a full dehydrogenation of NaAlH4 at 80°C and rehydrogenation at 30°C under 100 atm H2 with a reversible hydrogen capacity of 5 wt%, superior to all literature results reported so far. This indicates that nanostructured TiH2 is much more effective than Ti-dopants in improving the hydrogen storage performance of NaAlH4. Our finding not only pushes the practical application of NaAlH4 forward greatly but also opens up new opportunities to tailor the kinetics with the minimal capacity loss.

16.
Dalton Trans ; 49(19): 6312-6320, 2020 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-32338667

RESUMO

In order to satisfy the demand for the cyclic stability of commercial Ni-MH anodes, a PuNi3-type La0.6Gd0.2Mg0.2Ni2.6Co0.3Al0.1 alloy with excellent overall electrochemical properties was prepared by annealing the as-cast alloy sample at different temperatures for a week. The alloy had the highest PuNi3-type content of 86.9 wt% (1073 K), which offered a capacity retention of 69.6% after 100 cycles. However, 23.7 wt% PuNi3 type phase of the alloy constantly converted into the Ce2Ni7 type phase within a temperature increase of 50 °C, which improved the capacity retention by 12.1% under the same discharge capacity. We found that the addition of Gd did not change the stacked [LaMgNi4]/[LaNi5] superlattice and it maintained the structural stability of the crystal as well as its anti-corrosion, which is also a key factor to improve cyclic stability. These findings imply that alloys with both PuNi3-type and Ce2Ni7-type multiphase structures can be considered as a new choice for hydrogen storage.

17.
Dalton Trans ; 49(1): 156-163, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31793583

RESUMO

The influences of Gd and Co co-substitution for La and Ni on phase structures, and electrochemical properties of La0.83-xGdxMg0.17Ni3.35-2xCo2xAl0.15 (x = 0-0.83) alloys were investigated. All the alloys contained A2B7-type (Ce2Ni7- and Gd2Co7-type) phase, Pr5Co19-type phase, PuNi3-type phase and CaCu5-type phase. The partial replacement of Gd and Co for La and Ni increased the phase abundance of the Ce2Ni7-type superstructure and decreased cell volumes, which contributed to a better hydrogen absorption capacity, cyclic stability and HRD. Compared to those of single Gd- or Co-substitutions, the synergistic effects of Gd and Co on the overall electrochemical properties of alloys were significant. Such a superior overall electrochemical performance may result from appropriate cell volumes and anti-pulverization abilities.

18.
Adv Mater ; 32(10): e1907444, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31995271

RESUMO

The practical application of the lithium-sulfur (Li-S) battery is seriously restricted by its shuttle effect, low conductivity, and low sulfur loading. Herein, first-principles calculations are conducted to verify that the introduction of oxygen vacancies in TiO2 not only enhances polysulfide adsorption but also greatly improves the catalytic ability and both the ion and electron conductivities. A commercial polypropylene (PP) separator decorated with TiO2 nanosheets with oxygen vacancies (OVs-TiO2 @PP) is fabricated as a strong polysulfide barrier for the Li-S battery. The thickness of the OVs-TiO2 modification layer is only 500 nm with a low areal mass of around 0.12 mg cm-2 , which enhances the fast lithium-ion penetration and the high energy density of the whole cell. As a result, the cell with the OVs-TiO2 @PP separator exhibits a stable electrochemical behavior at 2.0 C over 500 cycles, even under a high sulfur loading of 7.1 mg cm-2 , and an areal capacity of 5.83 mAh cm-2 remains after 100 cycles. The proposed strategy of engineering oxygen vacancies is expected to have wide applications in Li-S batteries.

19.
Biomed Res Int ; 2020: 2854186, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33015160

RESUMO

OBJECTIVES: To evaluate the role of short-term low-dose glucocorticoids in mild COVID-19 patients. METHODS: We conducted a retrospective, cross-sectional, single-center study in Kunming, China. A total of 33 mild COVID-19 cases were divided into two treatment groups (with and without glucocorticoids, methylprednisolone, were used in this setting), and the absolute value of peripheral blood lymphocyte count; CD3+, CD4+, and CD8+ T cell counts; and the time to achieve negative transformation of a nucleic acid pharyngeal swab were recorded. Peripheral blood lymphocyte and T cell counts were compared between the treatment group and 25 healthy individuals. At the point of time when there was a 50% accumulation conversion rate (positive to negative nucleic acid on pharyngeal swab), and the nucleic acid turned negative in half of the patients in two groups, the peripheral blood lymphocyte and T cell counts were compared between treatment groups. RESULTS: The mean cumulative time for the 50% negative conversion rate of the nucleic acid in the pharyngeal swab was 17.7 ± 5.1 days and 13.9 ± 5.4 days in the glucocorticoid group and the nonglucocorticoid group, respectively. The absolute peripheral blood lymphocyte count and the T cell subset count in the glucocorticoid group were lower than those in the nonglucocorticoid group. When the nucleic acid turned negative in half of the patients, the absolute value of peripheral blood lymphocyte count and CD4+ T cells of the glucocorticoid group and the nonglucocorticoid group was not significantly different; the CD3+ and CD8+ T cells in the glucocorticoid group were lower than those in the nonglucocorticoid group. The absolute peripheral blood lymphocyte count, CD3+ T cells, and CD4+ T cells in the glucocorticoid group were lower than those of the healthy group during the whole disease period, and CD8+ T cells returned to normal at 19-21 days of the disease period. There was no significant difference between the nonglucocorticoid group and the healthy group for absolute peripheral blood lymphocyte and CD8+ T cells; moreover, CD3+ T cells and CD4+ T cells were lower in the nonglucocorticoid group than those in the healthy group from the day of admission to the 18th day and returned to normal at the period of 19-21 days. The absolute peripheral lymphocyte count (P = 0.048, effect size d = 0.727) and T cell subset count (CD3: P = 0.042, effect size d = 0.655; CD4: P < 0.01, effect size d = 0.599; and CD8: P = 0.034, effect size d = 0.550) in the nonglucocorticoid group were higher than those in the glucocorticoid group, and the difference between the groups was statistically significant. CONCLUSIONS: This study found that the use of short-term, low-dose glucocorticoids does not negatively influence the clinical outcome, without affecting the final clearance of viral nucleic acid in mild COVID-19 patients.


Assuntos
Betacoronavirus , Infecções por Coronavirus/tratamento farmacológico , Glucocorticoides/administração & dosagem , Pneumonia Viral/tratamento farmacológico , Adolescente , Adulto , Betacoronavirus/isolamento & purificação , COVID-19 , Criança , China/epidemiologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Estudos Transversais , Feminino , Humanos , Contagem de Linfócitos , Masculino , Metilprednisolona/administração & dosagem , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Estudos Retrospectivos , SARS-CoV-2 , Subpopulações de Linfócitos T/imunologia , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem , Tratamento Farmacológico da COVID-19
20.
ACS Appl Mater Interfaces ; 12(37): 42274-42284, 2020 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-32830480

RESUMO

Interactions between the active components with the support are one of the fundamentally factors in determining the catalytic performance of a catalyst. In contrast to the comprehensive understanding on the strong metal-support interactions (SMSI) in metal-based catalysts, it remains unclear for the interactions among different oxides in mixed oxide catalysts due to its complexity. In this study, we investigated the interaction between CeO2 and LaFeO3, the two important oxygen storage materials in catalysis area, by tuning the sizes of CeO2 particles and highlight a two-fold effect of the strong oxide-oxide interaction in determining the catalytic activity and selectivity for preferential CO oxidation in hydrogen feeds. It is found that the anchoring of ultra-fine CeO2 particles (<2 nm) at the framework of three-dimensional-ordered macroporous LaFeO3 surface results in a strong interaction between the two oxides that induces the formation of abundant uncoordinated cations and oxygen vacancy at the interface, contributing to the improved oxygen mobility and catalytic activity for CO oxidation. Hydrogen spillover, which is an important evidence of the strong metal-support interactions in precious metal catalysts supported by reducible oxides, is also observed in the H2 reduction process of CeO2/LaFeO3 catalyst due to the presence of ultra-fine CeO2 particles (<2 nm). However, the strong interaction also results in the formation of surface hydroxyl groups, which when combined with the hydrogen spillover reduces the selectivity for preferential CO oxidation. This discovery demonstrates that in hybrid oxide-based catalysts, tuning the interaction among different components is essential for balancing the catalytic activity and selectivity.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA