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1.
Inorg Chem ; 62(4): 1649-1658, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36652606

RESUMO

Early-actinide-based (U, Np, and Pu) single-molecule magnets (SMMs) have yet to show magnetic properties similar to those of highly anisotropic lanthanide-based ones. However, there are not many studies exploring the late-actinides (more than half-filled f shells) as potential candidates for SMM applications. We computationally explored the electronic structure and magnetic properties of a hypothetical Cf(III) complex isostructural to the experimentally synthesized Dy(dbm)3(bpy) complex (bpy = 2,2'-bipyridine; dbm = dibenzoylmethanoate) via multireference methods and compared them to those of the Dy(III) analogue. This study shows that the Cf(III) complex can behave as a SMM and has a greater magnetic susceptibility compared to other experimentally and computationally studied early-actinide-based (U, Np, and Pu) magnetic complexes. However, Cf spontaneously undergoes α-decay and converts to Cm. Thus, we also explored the isostructural Cm(III)-based complex. The computed magnetic susceptibility and g-tensor values show that the Cm(III) complex has poor SMM behavior in comparison to both the Dy(III) and Cf(III) complexes, suggesting that the performance of Cf(III)-based magnets may be affected by α-decay and can explain the poor performance of experimentally studied Cf(III)-based molecular magnets in the literature. Further, this study suggests that the ligand field is dominant in Cf(III), which helps to increase the magnetization blocking barrier by nearly 3 times that of its 4f congener.

2.
Phys Chem Chem Phys ; 25(46): 31804-31812, 2023 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-37966055

RESUMO

Interface engineering of the organo-lead halide perovskite devices has shown the potential to improve their efficiency and stability. In this study, the atomic, electronic, optical and transport characteristics of MAPbI3/Ga2O3 and MAPbCl3/Ga2O3 interfaces were investigated by using first-principles calculations. Eight different interfacial models were established and the interfacial properties were discussed. The results show that the PbI/O configuration exhibits the largest bonding strength out of all eight interfacial configurations. Owing to the larger interfacial interaction, the charge transfer at the PbI/O interface is significantly more than that at the other interfaces. The analysis of absorption spectra indicates that the Ga-terminated perovskite/Ga2O3 heterostructures are expected to have great potential for efficient optoelectronic applications. The analysis of transmission spectra shows that the MA/O configurations with more transmission peaks near the Fermi level exhibit lower resistance compared to others. The results of our study could help understand the interfacial engineering mechanism between perovskite and Ga2O3.

3.
Neurochem Res ; 46(7): 1627-1640, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33710538

RESUMO

Accumulating data suggest that the downregulation of DHCR24 is linked to the pathological risk factors of AD, denoting a potential role of DHCR24 in AD pathogenesis. However, it remains unclear whether the downregulation of DHCR24 affects the abnormal heper-phosphorylation of tau protein, which is involved in tauopathy. In present papers, immunofluorescence and Filipin III fluorescence results showed that DHCR24 knockdown significantly lowered the level of plasma membrane cholesterol and expression level of membrane lipid-raft structural protein caveolin-1; and overexpression of DHCR24 could increase the plasma membrane cholesterol levels and facilitating caveolae structure through increase the expression of caveolin-1. PP2A is the key phosphatase involving in tau phosphorylation, which is localized in cholesterol-dependent caveola/raft lipid domains. Here, the PP2A activity was detected by western blot assay. Interestingly, the level of p-PP2Ac at Y307 (inactive) and p-GSK3ß at Y216 (active) in the downstream of the PP2A signal pathway were both significantly increased in silencing DHCR24 SH-SY5Y cells, which denoted an inhibition of the PP2A and activation of GSK3ß signaling. Conversely, overexpression of DHCR24 blunted the inhibition effect of PP2A and activation of GSK3ß. Besides, in the SH-SY5Y cell lines we demonstrated that DHCR24 knockdown obviously induced hyperphosphorylation of tau at Thr181, Thr231, Ser262, Ser396, and Ser422 Sites. In contrast, DHCR24 overexpression protects neuronal SH-SY5Y cells against the hyperphosphorylation of tau at Thr181, Thr231, Ser262, Ser396, and Ser422 Sites. Furthermore, PP2A activator D-erythro-Sphingosine (DES) also obviously inhibited the hyperphosphorylation of tau induced by DHCR24 knockdown. Collectively, our findings firstly confirmed that DHCR24 knockdown obviously induced abnormal hyperphosphorylation of tau by a novel lipid raft-dependent PP2A signaling. We propose that DHCR24 downregulation led to altered cholesterol synthesis as a potential mechanism in the progression of tau hyperphosphorylation involving in AD and other tauopathies.


Assuntos
Proteínas do Tecido Nervoso/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/metabolismo , Fosforilação/genética , Transdução de Sinais/fisiologia , Proteínas tau/metabolismo , Caveolina 1/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/genética , Colesterol/metabolismo , Técnicas de Inativação de Genes , Glicogênio Sintase Quinase 3 beta/metabolismo , Humanos , Microdomínios da Membrana/metabolismo , Proteínas do Tecido Nervoso/genética , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , Proteína Fosfatase 2/metabolismo , Serina/química , Treonina/química , Proteínas tau/química
4.
Int J Urol ; 28(8): 855-860, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34013615

RESUMO

OBJECTIVE: To compare the safety and outcomes between green-light laser en bloc resection and transurethral resection of bladder tumor. METHODS: A single-center, randomized controlled trial was carried out from August 2014 to September 2018. Patients with initial non-muscle-invasive bladder cancer were randomized to green-light laser en bloc resection or transurethral resection of bladder tumor. The primary outcomes were pathological findings and perioperative events. The secondary outcome was tumor recurrence. RESULTS: A total of 233 patients were randomized to the transurethral resection of bladder tumor group (117 patients) and the green-light laser en bloc resection group (116 patients). The resection time was longer in the green-light laser en bloc resection group (P = 0.022); however, no differences were identified in overall operative time (P = 0.255). Nine patients (7.7%) had an obturator nerve reflex during transurethral resection of bladder tumor. The estimated volume of blood loss was significantly lower in the green-light laser en bloc resection group (P = 0.012). The green-light laser en bloc resection group had a higher rate of T1 bladder cancer (P = 0.031). A total of 104 patients (89.7%) treated with green-light laser en bloc resection had detrusor muscle presence in the specimen, whereas 37 (31.9%) patients had the presence of muscularis mucosae, which was significantly higher than the corresponding number of transurethral resection of bladder tumor patients (P = 0.005 and 0.002, respectively). After a median follow-up period of 48 months, just five patients had tumor recurrence (three in the transurethral resection of bladder tumor group and two in the green-light laser en bloc resection group), and there was no difference between these two groups. CONCLUSIONS: Compared with transurethral resection of bladder tumor, green-light laser en bloc resection is more effective due to less obturator nerve reflex and the same recurrence rate. Most importantly, green-light laser en bloc resection can provide better tumor specimens for pathological examinations.


Assuntos
Neoplasias da Bexiga Urinária , Humanos , Lasers , Recidiva Local de Neoplasia/epidemiologia , Duração da Cirurgia , Neoplasias da Bexiga Urinária/cirurgia , Procedimentos Cirúrgicos Urológicos
5.
Med Sci Monit ; 26: e921272, 2020 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-32339160

RESUMO

BACKGROUND The aim of this study was to compare the clinical safety and effectiveness of transurethral bipolar plasmakinetic enucleation of the prostate (PKEP) vs. transurethral bipolar plasmakinetic resection of the prostate (PKRP) in the treatment of benign prostate hyperplasia (BPH) more than 80 ml. MATERIAL AND METHODS From June 2015 to February 2019, 179 BPH patients with prostate volume greater than 80 ml were enrolled and separated into a PKEP (n=81) group and a PKRP group (n=98). The patients in the 2 groups were followed up for 6 months. We collected and analyzed data from the international Prostate Symptom Score (IPSS), residual urine volume (RUV), quality of life (QOL), maximum urine flow rate (Qmax), and international erectile function index (ILEF-5). The clinical data collected during and after the operation and surgical complications were compared between the 2 groups. RESULTS The PKEP group had significantly shorter operation time, bladder flushing time, indwelling catheter time, and hospitalization time, and has less intraoperative blood loss, intraoperative blood transfusion, postoperative secondary hemorrhage, bladder neck contracture, capsule perforation, and retrograde ejaculation (P<0.05). Compared with the PKRP group, the postoperative IPSS and QOL scores were significantly lower in the PKEP group (P<0.05), while the excision glandular tissue weight and Qmax were significantly improved (P<0.05). There were no significant differences in ILEF-5 scores, RUV, urethral stricture, urinary incontinence, or erectile dysfunction between the 2 groups (p>0.05). CONCLUSIONS PKEP treatment of BPH with a large volume (>80 ml) has the advantages of complete gland resection, good surgical effect, improved surgical safety, and reduced intraoperative and postoperative complications.


Assuntos
Hiperplasia Prostática/cirurgia , Ressecção Transuretral da Próstata/métodos , Incontinência Urinária/cirurgia , Idoso , Povo Asiático , China/epidemiologia , Disfunção Erétil/complicações , Humanos , Hiperplasia , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Complicações Pós-Operatórias/etiologia , Período Pós-Operatório , Próstata/patologia , Hiperplasia Prostática/complicações , Qualidade de Vida , Ressecção Transuretral da Próstata/efeitos adversos , Resultado do Tratamento , Bexiga Urinária/fisiopatologia
6.
Med Sci Monit ; 25: 4225-4232, 2019 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-31171764

RESUMO

BACKGROUND The aim of this study was to assess the efficacy and safety of "on-demand" dapoxetine in the treatment of premature ejaculation (PE). MATERIAL AND METHODS We performed a meta-analysis of intravaginal ejaculatory latency time (IELT), patient-reported global impression of change (PGIC), perceived control over ejaculation (PCOE), and drug-related adverse effects (AEs). We searched Medline, PubMed, Embase, CNKI, Wanfang, and VIP databases up to May 30, 2018 with the following search terms: "dapoxetine" or "SSRIs" and "premature ejaculation" or "sexual dysfunction". RESULTS Our analysis included 11 RCTs (8521 cases and 4338 controls). We found that IELT, PGIC, and PCOE in PE patients with "on-demand" dapoxetine were significantly higher than in the control group, and we observed higher proportions in 60 mg vs. 30 mg dapoxetine. The AEs were mild and tolerable. CONCLUSIONS "On-demand" dapoxetine is effective and safe for patients with PE, and a dose of 60 mg may be more effective than 30 mg.


Assuntos
Benzilaminas/administração & dosagem , Naftalenos/administração & dosagem , Ejaculação Precoce/tratamento farmacológico , Adulto , Benzilaminas/farmacologia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Ejaculação/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Naftalenos/farmacologia , Inibidores Seletivos de Recaptação de Serotonina/uso terapêutico , Resultado do Tratamento
7.
Inorg Chem ; 57(4): 1880-1887, 2018 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-29394064

RESUMO

The coexistence of radioactive contaminants (e.g., thorium, uranium, and their daughters) in rare earth minerals introduces significant environmental, economic, and technological hurdles in modern rare earth production. Efficient, low cost, and green decontamination strategies are therefore desired to ameliorate this problem. We report here a single-step and quantitative decontamination strategy of thorium from rare earths based on a unique periodic trend in the formation of crystalline selenite compounds across the lanthanide series, where Ce(III) is fully oxidized in situ to Ce(IV). This gives rise to a crystallization system that is highly selective to trap tetravalent f-blocks while all other trivalent lanthanides completely remain in solution when coexist. These results are bolstered by first-principles calculations of lattice energies and an examination of bonding in these compounds. This system is contrasted with typical natural and synthetic systems, where trivalent and tetravalent f-block elements often cocrystallize. The separation factors after one round of crystallization were determined from binary systems of Th(IV)/La(III), Th(IV)/Eu(III), and Th(IV)/Yb(III) to reach 2.1 × 105, 1.2 × 105, and 9 × 104, respectively. Selective crystallization of thorium from a simulated monazite composite yields a separation factor of 1.9 × 103 with nearly quantitative removal of thorium.

8.
Med Sci Monit ; 24: 272-287, 2018 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-29332100

RESUMO

BACKGROUND Robot-assisted radical prostatectomy (RARP) is increasingly used worldwide, but comparisons of perioperative, functional, and oncologic outcomes among RARP, laparoscopic radical prostatectomy (LRP), and open radical prostatectomy (ORP) remain inconsistent. MATERIAL AND METHODS Systematic literature searches were conducted using EMBASE, PubMed, the Cochrane Library, CNKI, and Science Direct/Elsevier up to April 2017. A meta-analysis was conducted using Review Manager and Stata software. RESULTS We included 33 studies. Meta-analysis revealed that blood loss, transfusion rate, and positive surgical margin (PSM) rate were significantly lower following RARP compared with LRP (SMD (95% confidence interval [CI]) 0.31 [0.01, 0.61]; combined ORs (95% CI) 5.32 [1.29, 21.98]; 1.27 [1.10, 1.46]) and ORP (SMD (95% CI) 0.75 [0.30, 1.21]; and combined ORs (95% CI) 3.44 [1.21, 9.79]); positive surgical margin (PSM) rates were significantly lower following RARP compared with LRP (combined ORs (95% CI) 1.27 [1.10, 1.46]), but not ORP. Operation time was also shorter for RARP than for LRP. The rates of nerve-sparing, recovery of complete urinary continence, and recovery of erectile function were significantly higher following RARP compared with LRP (combined ORs (95% CI) 0.55 [0.31, 0.95]; 0.66 [0.55, 0.78]; 0.46 [0.30, 0.71]) and ORP (combined ORs (95% CI) 0.36 [0.21, 0.63]; 0.33 [0.15, 0.74]; 0.65 [0.37, 1.14]). CONCLUSIONS This meta-analysis demonstrates that RARP results in better overall outcomes than LRP and ORP in terms of blood loss, transfusion rate, nerve sparing, urinary continence and erectile dysfunction recovery, and suggests that RARP offers better results than LRP and ORP in treatment of prostate cancer. However, studies with larger sample sizes and long-term results are needed.


Assuntos
Prostatectomia , Neoplasias da Próstata/cirurgia , Procedimentos Cirúrgicos Robóticos , Idoso , Perda Sanguínea Cirúrgica , Transfusão de Sangue , Disfunção Erétil/etiologia , Humanos , Laparoscopia , Masculino , Margens de Excisão , Pessoa de Meia-Idade , Duração da Cirurgia , Prostatectomia/efeitos adversos , Viés de Publicação , Procedimentos Cirúrgicos Robóticos/efeitos adversos , Incontinência Urinária/etiologia
9.
Analyst ; 140(18): 6226-9, 2015 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-26229987

RESUMO

The epithelial cell adhesion molecule (EpCAM) is a tumor-specific antigen for malignancies of the epithelialis lineage. In this study the interaction between the DNA-based EpCAM aptamer (SYL3C) and EpCAM was explored using single molecular recognition force spectroscopy (SMFS). The capability of aptamer SYL3C to recognize the EpCAM protein and the kinetic parameters were investigated.


Assuntos
Antígenos de Neoplasias/metabolismo , Aptâmeros de Nucleotídeos/metabolismo , Moléculas de Adesão Celular/metabolismo , Microscopia de Força Atômica/métodos , Linhagem Celular Tumoral , Molécula de Adesão da Célula Epitelial , Humanos
10.
Inorg Chem ; 54(17): 8617-24, 2015 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-26347292

RESUMO

Two uranyl carboxyphosphonates (H2dipy)[(UO2)3(H2O)2(H2DPTP)2]·2H2O (DPTP-U1) and (H2bbi)[(UO2)4(H2O)2(HDPTP)2] (DPTP-U2) [H6DPTP = 2,5-diphosphonoterephthalic acid, dipy = 4,4'-bipyridine, bbi = 1,1'-(1,4-butanediyl)bis(imidazole)] were synthesized under hydrothermal conditions. The carboxyphosphonate ligand was formed through the in situ oxidation of (2,5-dimethyl-1,4-phenylene)diphosphonic acid mediated by UO2(2+). Single-crystal X-ray diffraction analyses reveal that DPTP-U1 possesses uranyl carboxyphosphonate layers that are separated by protonated dipy cations. Whereas DPTP-U2 is in a three-dimensional framework structure with channels filled by protonated bbi cations. The computational investigations give an insight into the nature of bonding interactions between uranium(VI) and carboxyphosphonate ligand. The spectroscopic properties were also studied.

11.
J Chem Phys ; 143(11): 114707, 2015 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-26395728

RESUMO

In the present work, the behavior of He in the MAX phase Ti3AlC2 material is investigated using first-principle methods. It is found that, according to the predicted formation energies, a single He atom favors residing near the Al plane in Ti3AlC2. The results also show that Al vacancies are better able to trap He atoms than either Ti or C vacancies. The formation energies for the secondary vacancy defects near an Al vacancy or a C vacancy are strongly influenced by He impurity content. According to the present results, the existence of trapped He atoms in primary Al vacancy can promote secondary vacancy formation and the He bubble trapped by Al vacancies has a higher tendency to grow in the Al plane of Ti3AlC2. The diffusion of He in Ti3AlC2 is also investigated. The energy barriers are approximately 2.980 eV and 0.294 eV along the c-axis and in the ab plane, respectively, which means that He atoms exhibit faster migration parallel to the Al plane. Hence, the formation of platelet-like bubbles nucleated from the Al vacancies is favored both energetically and kinetically. Our calculations also show that the conventional spherical bubbles may be originated from He atoms trapped by C vacancies. Taken together, these results are able to explain the observed formation of bubbles in various shapes in recent experiments. This study is expected to provide new insight into the behaviors of MAX phases under irradiation from electronic structure level in order to improve the design of MAX phase based materials.


Assuntos
Alumínio/química , Berílio/química , Elétrons , Hélio/química , Titânio/química , Modelos Químicos , Teoria Quântica , Termodinâmica
13.
J Colloid Interface Sci ; 669: 804-815, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38749219

RESUMO

Herein, a novel copper selenide/zinc selenide/Nitrogen-doped carbon (Cu2Se/ZnSe/NC) sphere was constructed via a combination of cation exchange, selenization and carbonization approaches with zinc-based metal-organic frameworks (ZIF-8) as precursor for sulfadiazine (SDZ) removal. Compared with the ZnSe/NC, the defective Cu2Se/ZnSe interface in the optimizing Cu-ZnSe/NC2 sample caused a remarkably improved adsorption performance. Notably, the adsorption capacity of 129.32 mg/g was better than that of mostly reported adsorbents for SDZ. And the adsorption referred to multiple-layer physical-chemical process that was spontaneous and exothermic. Besides, the Cu-ZnSe/NC2 displayed fast adsorption equilibrium of about 20 min and significant anti-interference ability for inorganic ions. Specially, the adsorbent possessed excellent stability and reusability, which could also be applied for rhodamine B (RhB), methylene blue (MB), and methyl orange (MO) dyes removal. Ultimately, the charge redistribution of Cu2Se/ZnSe interface greatly contributes the superior adsorption performance for SDZ, in which electrostatic attraction occupied extremely crucial status as compared to π-π electron-donor-acceptor (π-π EDA) interaction and hydrogen bonding (H-bonding), as revealed by the density function theory (DFT) calculations and experimental results. This study can provide a guideline for design of high-efficient adsorbent with interfacial charge redistribution.

14.
Anal Chem ; 85(4): 2010-4, 2013 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-23350586

RESUMO

We present a new method for specific detection of oxytetracycline (OTC) at nanomolar concentrations based on a microfabricated cantilever array. The sensing cantilevers in the array are functionalized with self-assembled monolayers (SAMs) of OTC-specific aptamer, which acts as a recognition molecule for OTC. While the reference cantilevers in the array are functionalized with 6-mercapto-1-hexanol SAMs to eliminate the influence of environmental disturbances. The cantilever sensor shows a good linear relationship between the deflection amplitude and the OTC concentration in the range of 1.0-100 nM. The detection limit of the cantilever array sensor is as low as 0.2 nM, which is comparable to some traditional methods. Other antibiotics such as doxycycline and tetracycline do not cause significant deflection of the cantilevers. It is demonstrated that the cantilever array sensors can be used as a powerful tool to detect drugs with high sensitivity and selectivity.


Assuntos
Antibacterianos/análise , Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Oxitetraciclina/análise , Técnicas Biossensoriais/instrumentação , Ouro/química , Análise em Microsséries , Enxofre/química , Temperatura
15.
Neuroscience ; 513: 126-133, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36681141

RESUMO

Alzheimer's disease (AD) is a chronic neurological disorder with high morbidity. Exercise is one of the effective ways to ameliorate AD. In this study, we assessed the effects of exercise on cognition and inflammation and studied the role of miR-148a-3p in AD. In 88 patients with AD, the expression of miR-148a-3p was studied using qRT-PCR. ROC curve and Pearson analysis were utilized to evaluate the roles of miR-148a-3p in AD. MWM test was conducted to investigate the effects of miR-148a-3p and exercise on cognition and memory. Moreover, inflammatory indicators were identified using an enzyme-linked immunosorbent assay. Relative luciferase levels reflected whether miR-148a-3p targeted SYNJ1. miR-148a-3p levels declined in patients with AD, indicating its potential as a biomarker. Interestingly, miR-148a-3p levels were elevated in patients with AD after exercise. MiR-148a-3p levels correlated with cognitive scores and proinflammatory levels. The cognitive situation and pro-inflammatory state were partly recovered in the mice after exercise. MiR-148a-3p silencing reversed these abovementioned tendencies. Patients with AD exhibited a low level of miR-148a-3p, which was increased after exercise. Therefore, exercise might improve the cognitive function and memory of mice with AD by upregulating miR-148a-3p.


Assuntos
Doença de Alzheimer , MicroRNAs , Animais , Camundongos , Biomarcadores , Cognição , Inflamação , MicroRNAs/metabolismo
16.
Dalton Trans ; 52(36): 12948-12957, 2023 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-37646327

RESUMO

Supercapacitors (SCs) have been the subject of considerable interest because of their distinct advantages. The performance of SCs is directly affected by the electrode materials. Metal oxides derived from Prussian blue analogues (PBAs) are often used as electrode materials for SCs. Herein, we developed a multi-step strategy to fabricate ternary hollow metal oxide (CuO/NiO/Co3O4) heterostructures. The core-shell structured PBA (NiHCC@CuHCC) with Ni-based PBA (NiHCC) as the core and Cu-based PBA (CuHCC) as the shell was prepared by a crystal seed method. The ternary metal oxide (CuO/NiO/Co3O4) with a hollow structure was obtained by calcinating NiHCC@CuHCC. The prepared CuO/NiO/Co3O4 demonstrates an excellent specific capacitance of 262.5 F g-1 at 1 A g-1, which is 27.4% and 16.2% higher than those of CuO/Co3O4 and NiO/Co3O4, respectively. In addition, the material showed outstanding cycling stability with a capacitance retention of 107.9% after 3000 cycles. The two-electrode system constructed with CuO/NiO/Co3O4 and nitrogen-doped graphene hydrogel (NDGH) demonstrates a stable and high energy density of 27.1 W h kg-1 at a power density of 1037.5 W kg-1. The capacitance retention rate was 100.7% after 4000 cycles. The reason for the excellent electrochemical properties could be the synergistic effect of the introduced heterojunction of CuO/NiO, the hollow structure, and various metal oxides. This strategy can greatly inspire the construction of SC electrodes.

17.
Materials (Basel) ; 16(15)2023 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-37570159

RESUMO

MAX phases have exhibited diverse physical properties, inspiring their promising applications in several important research fields. The introduction of a chalcogen atom into a phase of MAX has further facilitated the modulation of their physical properties and the extension of MAX family diversity. The physical characteristics of the novel chalcogen-containing MAX 211 phase Zr2SeB and Zr2SeN have been systematically investigated. The present investigation is conducted from a multi-faceted perspective that encompasses the stability, electronic structure, and mechanical properties of the system, via the employment of the first-principles density functional theory methodology. By replacing C with B/N in the chalcogen-containing MAX phase, it has been shown that their corresponding mechanical properties are appropriately tuned, which may offer a way to design novel MAX phase materials with enriched properties. In order to assess the dynamical and mechanical stability of the systems under investigation, a thorough evaluation has been carried out based on the analysis of phonon dispersions and elastic constants conditions. The predicted results reveal a strong interaction between zirconium and boron or nitrogen within the structures of Zr2SeB and Zr2SeN. The calculated band structures and electronic density of states for Zr2SeB and Zr2SeN demonstrate their metallic nature and anisotropic conductivity. The theoretically estimated Pugh and Poisson ratios imply that these phases are characterized by brittleness.

18.
Biol Direct ; 18(1): 59, 2023 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-37723551

RESUMO

BACKGROUND: The thymus is required for T cell development and the formation of the adaptive immunity. Stromal cells, which include thymic epithelial cells (TECs) and mesenchymal stromal cells (MSCs), are essential for thymic function. However, the immunomodulatory function of thymus-derived MSCs (T-MSCs) has not been fully explored. METHODS: MSCs were isolated from mouse thymus and their general characteristics including surface markers and multi-differentiation potential were characterized. The immunomodulatory function of T-MSCs stimulated by IFN-γ and TNF-α was evaluated in vitro and in vivo. Furthermore, the spatial distribution of MSCs in the thymus was interrogated by using tdTomato-flox mice corssed to various MSC lineage Cre recombinase lines. RESULTS: A subset of T-MSCs express Nestin, and are mainly distributed in the thymic medulla region and cortical-medulla junction, but not in the capsule. The Nestin-positive T-MSCs exhibit typical immunophenotypic characteristics and differentiation potential. Additionally, when stimulated with IFN-γ and TNF-α, they can inhibit activated T lymphocytes as efficiently as BM-MSCs, and this function is dependent on the production of nitric oxide (NO). Additionally, the T-MSCs exhibit a remarkable therapeutic efficacy in acute liver injury and inflammatory bowel disease (IBD). CONCLUSIONS: Nestin-positive MSCs are mainly distributed in medulla and cortical-medulla junction in thymus and possess immunosuppressive ability upon stimulation by inflammatory cytokines. The findings have implications in understanding the physiological function of MSCs in thymus.


Assuntos
Células-Tronco Mesenquimais , Óxido Nítrico , Animais , Camundongos , Nestina , Fator de Necrose Tumoral alfa , Imunidade Adaptativa
19.
ACS Omega ; 7(45): 40929-40940, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36406488

RESUMO

As a large family of two-dimensional materials, MXenes have attracted intensive attention in recent years. For more functional applications, it is of great significance to determine new MXene members. Here, we theoretically expand the M elements of MXenes to the lanthanide series. Based on density functional theory calculations, the bare lanthanide-based carbides M2C (M = Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb) and the corresponding fluorine- and hydroxyl-terminated configurations are investigated. Most of the fluorine- and hydroxyl-terminated MXenes investigated are half-metals. Specifically, in the half-metallic Eu2CF2, the spin-down states show a band gap larger than 2 eV, implying this configuration's potential applications in spin generation and injection. Both Gd2CT2 (T = F and OH) are magnetic semiconductors. The former shows an indirect band gap of 1.38 eV, while the latter presents a direct one of 0.882 eV. These two configurations also show large magnetic moments higher than 13.7 µB per unit cell. All the hydroxyl-terminated MXene members show relatively low work functions, with the lowest value of 1.46 eV determined in Tm2C(OH)2. These predicted electronic properties imply that the lanthanide-based MXenes could have potential applications in spintronics, information storage, near-infrared detectors, field effect transistors, and field emitter cathodes.

20.
ACS Nano ; 16(6): 9062-9076, 2022 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-35653439

RESUMO

Biopolymer/silica nanocomposite aerogels are highly attractive as thermally insulating materials for prevailing energy-saving engineering but are usually plagued by their lack of mechanical strength and environmental stability. Lignin is an appealing plant phenolic biopolymer due to its natural abundance, high stiffness, water repellency, and thermostability. However, integrating lignin and silica into high-performance 3D hybrid aerogels remains a substantial challenge due to the unstable co-sol process. In diatoms, the silicic acid stabilization prior to the condensation reaction is enhanced by the intervention of biomolecules in noncovalent interactions. Inspired by this mechanism, we herein rationally design an ultrastrong silica-mineralized lignin nanocomposite aerogel (LigSi) with an adjustable multilevel micro/nanostructure and arbitrary machinability through an unusual water-induced self-assembly and in situ mineralization based on ethylene glycol-stabilized lignin/siloxane colloid. The optimized LigSi exhibits an ultrahigh stiffness (a specific modulus of ∼376.3 kN m kg-1) and can support over 5000 times its own weight without obvious deformation. Moreover, the aerogel demonstrates a combination of outstanding properties, including superior and humidity-tolerant thermal insulation (maintained at ∼0.04 W m-1 K-1 under a relative humidity of 33-94%), excellent fire resistance withstanding an ∼1200 °C flame without disintegration, low near-infrared absorption (∼9%), and intrinsic self-cleaning/superhydrophobic performance (158° WCA). These advanced properties make it an ideal thermally insulating material for diversified applications in harsh environments. As a proof of concept, a dual-mode LigSi thermal device was designed to demonstrate the application prospect of combining passive heat-trapping and active heating in the building.


Assuntos
Lignina , Água , Água/química , Lignina/química , Celulose/química , Géis/química , Biopolímeros/química , Dióxido de Silício/química , Glicóis
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