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1.
J Chem Phys ; 154(9): 094703, 2021 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-33685134

RESUMEN

Solid-state electrolyte materials with superior lithium ionic conductivities are vital to the next-generation Li-ion batteries. Molecular dynamics could provide atomic scale information to understand the diffusion process of Li-ion in these superionic conductor materials. Here, we implement the deep potential generator to set up an efficient protocol to automatically generate interatomic potentials for Li10GeP2S12-type solid-state electrolyte materials (Li10GeP2S12, Li10SiP2S12, and Li10SnP2S12). The reliability and accuracy of the fast interatomic potentials are validated. With the potentials, we extend the simulation of the diffusion process to a wide temperature range (300 K-1000 K) and systems with large size (∼1000 atoms). Important technical aspects such as the statistical error and size effect are carefully investigated, and benchmark tests including the effect of density functional, thermal expansion, and configurational disorder are performed. The computed data that consider these factors agree well with the experimental results, and we find that the three structures show different behaviors with respect to configurational disorder. Our work paves the way for further research on computation screening of solid-state electrolyte materials.

2.
Cell Mol Neurobiol ; 40(6): 927-937, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31916070

RESUMEN

Traumatic brain injury (TBI) causes permanent neurological and cognitive impairments. Effective pharmacological interventions remain elusive. Spermidine is a polyamine compound found in our body that may play a role in brain development and congenital function. In this study, we aimed to investigate the therapeutic potential of spermidine for TBI. We employed experimental closed head injury (CHI) model to evaluate the protective function of spermidine on brain injury. We assessed the neurobehavioral function recovery using Neurologic Severity Score (NSS) and Morris water maze test. At histological level, we evaluated the improvement on brain edema, brain-blood barrier integrity, and cell apoptosis. We also measured inflammatory cytokines and brain injury biomarkers to monitor the treatment outcomes. Last, we correlated the level of spermidine with CHI animal model and TBI patients with different levels of severity. Spermidine administration post-CHI was found effectively to accelerate NSS improvement and shorten latency in maze test. We observed consistent improvements in brain edema, BBB function, and cell death in spermidine-treated group. Inflammatory cytokines and TBI biomarkers, e.g., S100B, MBP and CFAP were reduced significantly in treatment group. Interestingly, inhibiting spermidine synthesis influenced the neurobehavioral recovery in CHI mice. ODC1, a rate-limiting enzyme for spermidine synthesis, was found lower in CHI mice. Serum level of spermidine was significantly lower in TBI patients with severe pathological scores. Spermidine pathway may carry an endogenous role in pathophysiological process of CHI. For the first time, we demonstrated that administrating spermidine may provide a new treatment for TBI.


Asunto(s)
Lesiones Traumáticas del Encéfalo/tratamiento farmacológico , Fármacos Neuroprotectores/uso terapéutico , Espermidina/uso terapéutico , Adulto , Animales , Lesiones Traumáticas del Encéfalo/sangre , Modelos Animales de Enfermedad , Femenino , Humanos , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Ratones Endogámicos BALB C , Proteínas del Tejido Nervioso/sangre , Fármacos Neuroprotectores/química , Fármacos Neuroprotectores/farmacología , Espermidina/sangre , Espermidina/química , Espermidina/farmacología
3.
Chemistry ; 23(66): 16898-16905, 2017 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-28960575

RESUMEN

The lack of suitable high-voltage cathode materials has hindered the development of rechargeable magnesium batteries (RMBs). Here, mesoporous Na3 V2 (PO4 )3 /C (NVP/C) spheres have been synthesized through a facile spray-drying-annealing method, and their electrochemically desodiated phase NaV2 (PO4 )3 /C (ED-NVP/C) has been investigated as an intercalation host for Mg2+ ions. The obtained ED-NVP/C exhibits an average discharge voltage of around 2.5 V (vs. Mg2+ /Mg), higher than those of most previously reported cathode materials. In addition, it can deliver an initial discharge capacity of 88.8 mA h g-1 at 20 mA g-1 , with good cycling stability. Ex situ X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) results demonstrate that the electrochemical reaction is based on an intercalation mechanism and shows good reversibility. Galvanostatic intermittent titration technique (GITT) data have revealed that the intercalation process involves a two-phase transition. The reported ED-NVP/C cathode material with high working voltage offers promising potential for application in RMBs.

4.
Zhonghua Yi Xue Za Zhi ; 94(47): 3763-6, 2014 Dec 23.
Artículo en Zh | MEDLINE | ID: mdl-25623104

RESUMEN

OBJECTIVE: To summarize the clinical experiences of microsurgical and endovascular treatments of complicated arteriovenous malformation (AVM) in the conditions of hybrid operating room. METHODS: The clinical data were collected and analyzed for 8 patients of complex AVM between June 2012 to June 2013. There were Spetzler grade III (n = 2) and grade IV (n = 6). And the lesions were complicated with intracranial aneurysms (n = 3) and located in motor area (n = 2) and basal ganglia (n = 2). Five cases of AVM with cerebral hemorrhage underwent emergency surgery, including digital subtraction angiography (DSA) plus intraoperative embolization plus surgical resection of AVM plus intraoperative DSA (iDSA). Two cases underwent embolization plus aneurysm surgery while another had AVM embolization plus AVM resection and γ knife treatment. RESULTS: All surgical procedures, including iDSA, were completed in the same hybrid operating room. There was no change of surgical position or intraoperative mortality. Five patients of AVM hemorrhage undergoing emergency hematoma evacuation had no residue of AVM on iDSA. Their postoperative consciousness improved without neurological dysfunction. Two patients of limb paralysis recovered to paresis at 3 months postoperation. One case with blurry vision improved somewhat. Two cases undergoing elective surgery had a complete resection of AVM after embolization. CONCLUSION: Surgery plus endovascular treatment in hybrid operating room is efficacious for complex cerebral AVM. It avoids multiple surgeries and inspections. And any lesion residue may be assessed immediately with postoperative DSA.


Asunto(s)
Quirófanos , Angiografía de Substracción Digital , Hemorragia Cerebral , Embolización Terapéutica , Humanos , Aneurisma Intracraneal , Malformaciones Arteriovenosas Intracraneales , Radiocirugia , Resultado del Tratamiento , Venas
5.
Physiol Behav ; 273: 114405, 2024 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-37939829

RESUMEN

BACKGROUND: Spinal cord injury (SCI) is a highly traumatic injury that causes mechanical damage to the spinal cord. Our study aimed to investigate whether gallic acid has protective effects against SCI injury. METHODS: Adult male rats were subjected to contusive spinal cord injuries. For behavioural evaluation, the rats were given gallic acid by i.p. injection at the doses of 10, 50 or 100 mg/kg immediately after SCI once daily for consecutive 28 days. Behavioral tests were used to evaluate locomotor functions, mechanical sensitivity and nerve conduction functions. For biochemical experiments, the rats were randomly divided into three groups: sham group, SCI group and SCI+gallic acid group. The rats in the SCI+gallic acid group were given gallic acid at the dose of 100 mg/kg immediately after SCI once daily for consecutive 14 days. The levels of inflammatory factors were evaluated. RESULTS: Gallic acid treatment could improve locomotive and sensory function and reduce the functional impairments in SCI rats. The effects were more effective with increasing gallic acid dose. The levels of M1 markers (inducible nitric oxide synthase and cyclooxygenase-2) were decreased in gallic acid-treated SCI rats, whereas the levels of M2 markers (arginase 1 and cluster of differentiation 206) were increased in response to gallic acid administration. Gallic acid treatment resulted in a significant reduction in pro-inflammatory cytokines and an increase in anti-inflammatory cytokine levels. CONCLUSION: Gallic acid enhances the recovery in SCI rats by regulating microglial polarization. The underlying mechanism may involve the promotion of M2 polarization and the suppression of M1 polarization in microglia.


Asunto(s)
Microglía , Traumatismos de la Médula Espinal , Ratas , Animales , Masculino , Inflamación/tratamiento farmacológico , Médula Espinal , Traumatismos de la Médula Espinal/complicaciones , Citocinas
6.
J Vasc Surg Venous Lymphat Disord ; 12(4): 101897, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38679143

RESUMEN

OBJECTIVE: We investigated the feasibility and efficacy of assessing calf perforating veins (PVs) using the ankle pump in a sitting position (AP-sit) method by color Doppler ultrasound. METHODS: We performed a multicenter prospective clinical trial between November 2022 and October 2023. Eligible patients with chronic venous disease and healthy controls were enrolled. The calf PVs were assessed using three different methods: manual compression in a standing position, manual compression in a sitting position, and AP-sit method. The reflux durations and detection rate of incompetent PVs (IPVs) were compared among the three methods. The number and diameter of calf PVs and distribution of IPVs were analyzed. RESULTS: A total of 50 patients with chronic venous disease and 50 healthy controls were included. There were 173 calves analyzed, including 97 healthy calves and 76 calves with chronic venous disease. The number of PVs per calf was higher in the diseased calves (median, 7.0; interquartile range [IQR], 6.0-8.0) than in the healthy calves (median, 5.0; IQR, 3.0-6.0; P < .001). The diameter of IPVs (median, 2.3 mm; IQR, 2.0-3.1 mm) was larger than that of competent PVs (median, 1.4 mm; IQR, 1.2-1.7 mm). Most of the IPVs (78.8%) were located in the medial and posterior middle of the calf. The reflux duration induced by the AP-sit method was greater than that induced by the manual compression methods (P < .001). Although the AP-sit method had a higher detection rate (92.0%) of IPVs than the manual compression methods (71.7% and 74.3% for standing and sitting, respectively; P < .001), especially in the distal lower leg, the manual compression methods found IPVs not found using the AP-sit method. CONCLUSIONS: Diseased calves with chronic venous disease have more PVs than do healthy calves. IPVs are commonly larger than competent PVs, with most IPVs located in the medial and posterior middle of the calf. Most importantly, the AP-sit method provides a convenient and effective approach for assessing the calf PVs, especially those located in the distal calf, as an alternative or complementary method to traditional manual compression, which is valuable in the daily practice of sonographers.


Asunto(s)
Estudios de Factibilidad , Sedestación , Ultrasonografía Doppler en Color , Insuficiencia Venosa , Estudios Prospectivos , Humanos , Femenino , Masculino , Persona de Mediana Edad , Insuficiencia Venosa/diagnóstico por imagen , Insuficiencia Venosa/fisiopatología , Enfermedad Crónica , Valor Predictivo de las Pruebas , Adulto , Anciano , Posicionamiento del Paciente , Estudios de Casos y Controles , Pierna/irrigación sanguínea , Pierna/diagnóstico por imagen , Venas/diagnóstico por imagen , Flujo Sanguíneo Regional
7.
Front Genet ; 15: 1372164, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39165753

RESUMEN

Background: Preeclampsia (PE) is a global pregnancy concern, characterized by hypertension with an unclear etiology. This study employs Mendelian randomization (MR) and single-cell RNA sequencing (scRNA-seq) to clarify its genetic and molecular roots, offering insights into diagnosis and treatment avenues. Methods: We integrated PE-specific genome-wide association study (GWAS) data, expression and protein quantitative trait loci (eQTL and pQTL) data, and single-cell data from peripheral blood mononuclear cells (PBMCs). We identified highly variable genes using single-cell information and employed MR to determine potential causality. We also combined pQTL and GWAS data, discerned genes positively associated with PE through scRNA-seq, and leveraged the Enrichr platform to unearth drug-gene interactions. Results: Our scRNA-seq pinpointed notable cell type distribution variances, especially in T helper cells (Th cells), between PE and control groups. We unveiled 591 highly variable genes and 6 directly PE-associated genes. Although MR revealed correlations with PE risk, pQTL analysis was inconclusive due to data constraints. Using DSigDB, 93 potential therapeutic agents, like Retinoic acid targeting core genes (IFITM3, NINJ1, COTL1, CD69, and YWHAZ), emerged as prospective multi-target treatments. Conclusion: Utilizing MR and scRNA-seq, this study underscores significant cellular disparities, particularly in Th cells, and identifies crucial genes related to PE. Despite some limitations, these genes have been revealed in PE's underlying mechanism. Potential therapeutic agents, such as Retinoic acid, suggest promising treatment pathways.

8.
BMC Med Genomics ; 16(1): 39, 2023 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-36859245

RESUMEN

OBJECTIVE: A total of 5,200 pregnant women in Zhaoqing city, Guangdong Province, were screened to identify spinal muscular atrophy (SMA) mutation carriers to guide the prevention of SMA and prevent the birth of children with SMA. METHODS: Exons 7 and 8 (E7 and E8) of the survival motor neuron (SMN) 1 gene were detected in women using real-time fluorescence quantitative polymerase chain reaction. SMN1 and SMN2 copy numbers in those who were initially identified as carriers were verified via targeted region capture and next-generation sequencing. When both partners were identified as carriers, prenatal diagnosis of the fetus was performed. RESULTS: Among the screened women, 75 SMA carriers (71 cases had both E7 and E8 heterozygous deletions and 4 cases only had an E7 heterozygous deletion) were identified, with a carrier frequency of 1.44% (95% confidence interval: 1.31-1.65%). Three couples where both spouses were identified as SMA carriers, and their three fetuses were subjected to prenatal genetic analysis. Of the three, one had homozygous deletions of E7 and E8 and the other two had heterozygous deletions of E7 and E8. After a detailed prenatal consultation, the former couple decided to terminate the pregnancy. CONCLUSION: Through screening and prenatal diagnosis of pregnant women in Zhaoqing city, Guangdong Province, the incidence of SMA can be reduced, prevention of birth defects can be improved, incidence of birth defects can be effectively minimized.


Asunto(s)
Eliminación de Gen , Atrofia Muscular Espinal , Diagnóstico Prenatal , Proteína 1 para la Supervivencia de la Neurona Motora , Femenino , Humanos , Embarazo , China , Neuronas Motoras , Mujeres Embarazadas , Atrofia Muscular Espinal/diagnóstico , Proteína 1 para la Supervivencia de la Neurona Motora/genética
9.
Adv Healthc Mater ; 12(29): e2301990, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37467758

RESUMEN

To achieve synchronous repair and real-time monitoring the infarcted myocardium based on an integrated ion-conductive hydrogel patch is challenging yet intriguing. Herein, a novel synthetic strategy is reported based on core-shell-structured curcumin-nanocomposite-reinforced ion-conductive hydrogel for synchronous heart electrophysiological signal monitoring and infarcted heart repair. The nanoreinforcement and multisite cross-linking of bioactive curcumin nanoparticles enable well elasticity with negligible hysteresis, implantability, ultrahigh mechanoelectrical sensitivity (37 ms), and reliable sensing capacity (over 3000 cycles) for the nanoreinforced hydrogel. Results of in vitro and in vivo experiments demonstrate that such solely physical microenvironment of electrophysiological and biomechanical characteristics combining with the role of bioactive curcumin exert the synchronous benefit of regulating inflammatory microenvironment, promoting angiogenesis, and reducing myocardial fibrosis for effective myocardial infarction (MI) repair. Especially, the hydrogel sensors offer the access for achieving accurate acquisition of cardiac signals, thus monitoring the whole MI healing process. This novel bioactive and electrophysiological-sensing ion-conductive hydrogel cardiac patch highlights a versatile strategy promising for synchronous integration of in vivo real-time monitoring the MI status and excellent MI repair performance.


Asunto(s)
Curcumina , Infarto del Miocardio , Humanos , Hidrogeles , Curcumina/farmacología , Miocardio , Infarto del Miocardio/tratamiento farmacológico , Prótesis e Implantes
10.
Adv Mater ; 35(9): e2209497, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36527726

RESUMEN

It is challenging to balance high biocompability with good mechanical-electrical sensing performance, especially when triggering inflammatory stress response after in vivo implantation. Herein, a bioinspired wrinkle-reinforced adaptive nanoclay-interlocked soft strain-sensor based on a highly stretchable and elastic ionic-conductive hydrogel is reported. This novel nanoclay-composite hydrogel exhibits excellent tensile properties and high sensing capacity with steady and reliable sensing performance due to the structural-mechanical-electrical integrity of the nanoclay crosslinked and nano-reinforced interpenetrating network. The incorporation of amphiphilic ions provides the hydrogel with significant protein resistance, reducing its non-specific adsorption to proteins upon implantation, improving its biosafety as an implanted device, and maintaining the authenticity of the sensing results. Based on the revealed sensing enhanced mechanism based on hierarchical ordered structures as a proof-of-concept application, this hydrogel sensor is demonstrated to be able to accurately localize the region where myocardial infarction occurs and may become a novel strategy for real-time monitoring of pathological changes in heart disease.


Asunto(s)
Hidrogeles , Infarto del Miocardio , Humanos , Hidrogeles/química , Infarto del Miocardio/patología , Conductividad Eléctrica
11.
Natl Sci Rev ; 9(8): nwac084, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35992230

RESUMEN

Non-graphitic carbons are promising anode candidates for sodium-ion batteries, while their variable and complicated microstructure severely limits the rational design of high-energy carbon anodes that could accelerate the commercialization of sodium-ion batteries, as is the case for graphite in lithium-ion batteries. Here, we propose sieving carbons, featuring highly tunable nanopores with tightened pore entrances, as high-energy anodes with extensible and reversible low-potential plateaus (<0.1 V). It is shown that the tightened pore entrance blocks the formation of the solid electrolyte interphase inside the nanopores and enables sodium clustering to produce the plateau. Theoretical and spectroscopic studies also show that creating a larger area of sodiophilic pore surface leads to an almost linearly increased number of sodium clusters, and controlling the pore body diameter guarantees the reversibility of sodium cluster formation, producing a sieving carbon anode with a record-high plateau capacity of 400 mAh g-1. More excitingly, this approach to preparing sieving carbons has the potential to be scalable for modifying different commercial porous carbons.

12.
Top Curr Chem (Cham) ; 379(4): 27, 2021 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-34101036

RESUMEN

Atomistic machine learning (AML) simulations are used in chemistry at an ever-increasing pace. A large number of AML models has been developed, but their implementations are scattered among different packages, each with its own conventions for input and output. Thus, here we give an overview of our MLatom 2 software package, which provides an integrative platform for a wide variety of AML simulations by implementing from scratch and interfacing existing software for a range of state-of-the-art models. These include kernel method-based model types such as KREG (native implementation), sGDML, and GAP-SOAP as well as neural-network-based model types such as ANI, DeepPot-SE, and PhysNet. The theoretical foundations behind these methods are overviewed too. The modular structure of MLatom allows for easy extension to more AML model types. MLatom 2 also has many other capabilities useful for AML simulations, such as the support of custom descriptors, farthest-point and structure-based sampling, hyperparameter optimization, model evaluation, and automatic learning curve generation. It can also be used for such multi-step tasks as Δ-learning, self-correction approaches, and absorption spectrum simulation within the machine-learning nuclear-ensemble approach. Several of these MLatom 2 capabilities are showcased in application examples.


Asunto(s)
Simulación por Computador , Hidrocarburos Cíclicos/química , Aprendizaje Automático , Programas Informáticos , Estructura Molecular
13.
Nanotechnology ; 21(22): 225707, 2010 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-20453277

RESUMEN

Vertically well-aligned ZnO nanorod arrays with three kinds of tip morphology-abruptly sharpened, tapered and plane-have been controllably fabricated with wafer size uniformity by vapor phase transport and condensation. Except that the tip morphology is distinctly different, all of these nanorods are single crystalline, growing along their wurtzite 0001 axis, with similar diameters, lengths and densities. The field emission properties of these nanorod arrays are comparatively investigated and are found to be strongly affected by the tip morphology. A nanorod with the abruptly sharpened tip possesses the lowest turn-on and threshold electric fields as well as the highest field enhancement factor. Further analysis reveals that the abruptly sharpened tip morphology can reduce the screening effect more efficiently than the others. These results are very helpful for the design, fabrication and optimization of integrated field emitters using 1D nanostructures as the cathode material.

14.
Front Psychiatry ; 11: 414, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32457671

RESUMEN

BACKGROUND: In western countries, there is a negative association between religious belief and suicide risk, while in China this association is positive. Nevertheless, few data are available on the association between one specific type of religion and suicide risk, which might be different from the overall positive religion-suicide association in China. This study examined the association between Buddhist belief and suicide risk in Chinese persons receiving methadone maintenance therapy (MMT) for heroin dependence. METHODS: In total, 61 Buddhist believers and 425 age, gender, and clinic frequency-matched non-religious believers were selected from a sample of patients with heroin dependence treated in three MMT clinics in Wuhan, China. The suicidality module of the Chinese version of the Mini-international Neuropsychiatric Interview 5.0 was used to assess current suicide risk. Patients' demographic and clinical characteristics were also collected. Multiple ordinary logistic regression was used to analyze the association between Buddhist belief and current suicide risk, controlling for the confounding effects of demographic and clinical factors. RESULTS: In Chinese patients receiving MMT for heroin dependence, Buddhist believers had significantly higher levels of current suicide risk than non-religious believers (low: 45.9% vs. 24.7%, medium: 4.9% vs. 3.5%, high: 19.7% vs. 12.5%, P < 0.001). After adjusting for demographic and clinical covariates (including depressive symptoms), Buddhist belief was still significantly associated with an increase in the level of current suicide risk (OR: 2.98, P < 0.001). CONCLUSION: Buddhist belief is significantly associated with elevated current suicide risk in Chinese patients receiving MMT for heroin independence. In Chinese MMT clinics, patients with Buddhist belief may have a high current suicide risk and a timely psychiatric assessment and crisis intervention (when necessary) should be provided to these patients.

15.
ACS Appl Mater Interfaces ; 10(16): 13491-13498, 2018 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-29616799

RESUMEN

In this study, one-dimensional Cu2- xSe nanorods synthesized by a simple water evaporation-induced self-assembly approach are served as the anode material for Na-ion batteries for the first time. Cu2- xSe electrodes express outstanding electrochemical properties. The initial discharge capacity is 149.3 mA h g-1 at a current density of 100 mA g-1, and the discharge capacity can remain at 106.2 mA h g-1 after 400 cycles. Even at a high current density of 2000 mA g-1, the discharge capacity of the Cu2- xSe electrode still remains at 62.8 mA h g-1, showing excellent rate performance. Owing to the excellent electronic conductivity and one-dimensional structure of Cu2- xSe, the Cu2- xSe electrodes manifest fast Na+ ion diffusion rate. Moreover, detailed Na+ insertion/extraction mechanism is further investigated by ex situ measurements and theoretical calculations.

16.
ACS Appl Mater Interfaces ; 9(5): 4397-4403, 2017 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-27479707

RESUMEN

The Prussian blue, as a potential adsorbent of polysulfides to suppress the dissolution and shuttle of polysulfides for lithium-sulfur batteries, has been studied in this work. Our results show that Prussian blue improves the electrochemical reaction kinetics during discharge/charge processes. More importantly, the cathode with Prussian blue exhibits better cycling stability and higher discharge capacity retention (722 mAh g-1 at 0.2 A g-1 after 100 cycles) than the one without Prussian blue (151 mAh g-1). These improvements of electrochemical performances are ascribed to the fact that Prussian blue is very effective in suppressing the dissolution of polysulfides into liquid electrolyte by chemical adsorption.

17.
ChemSusChem ; 10(10): 2235-2241, 2017 05 22.
Artículo en Inglés | MEDLINE | ID: mdl-28383799

RESUMEN

A rod-like Cu2-x Se is synthesized by a facile water evaporation process. The electrochemical reaction mechanism is investigated by ex situ X-ray diffraction (XRD). By adopting an ether-based electrolyte instead of a carbonate-based electrolyte, the electrochemical performance of Cu2-x Se electrodes improved significantly. The Cu2-x Se electrodes exhibit outstanding cycle performance: after 1000 cycles, 160 mA h g-1 can be maintained with a retention of 80.3 %. At current densities of 100, 200, 500, and 1000 mA g-1 , the capacity of a Cu2-x Se/Li battery was 208, 202, 200, and 198 mA h g-1 , respectively, showing excellent rate capability. The 4-probe conductivity measurements along with electrochemical impendence spectroscopy (EIS) and cyclic voltammetry (CV) tests illustrate that the Cu2-x Se electrodes display high specific conductivity and impressive lithium-ion diffusion rate, which makes the Cu2-x Se a promising anode material for lithium-ion batteries.


Asunto(s)
Cobre/química , Suministros de Energía Eléctrica , Litio/química , Selenio/química , Microscopía Electrónica , Espectrometría Raman , Difracción de Rayos X
18.
ACS Appl Mater Interfaces ; 9(34): 28486-28494, 2017 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-28770985

RESUMEN

The Li3VO4@C microsphere composite was first reported as a novel cathode material for rechargeable aluminum-ion batteries (AIBs), which manifests the initial discharge capacity of 137 mAh g-1 and and remains at 48 mAh g-1 after 100 cycles with almost 100% Coulombic efficiency. The detailed intercalation mechanism of Al into the orthorhombic Li3VO4 is investigated by ex situ X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) of Li3VO4@C electrodes and the nuclear magnetic resonance aluminum spectroscopy (27Al NMR) of ionic liquid electrolytes in different discharge/charge states. First-principle calculations are also carried out to investigate the structural change as Al inserts into the framework of Li3VO4. It is revealed that the Al/Li3VO4@C battery goes through electrochemical dissolution and deposition of metallic aluminum in the anode, as well as the insertion and deinsertion of Al3+ cations in the cathode in the meantime. The rechargeable AIBs fabricated in this work are of low cost and high safety, which may make a step forward in the development of novel cathode materials based on the acidic ionic liquid electrolyte system.

19.
J Phys Chem B ; 110(21): 10296-302, 2006 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-16722732

RESUMEN

Large-area aligned Mo nanowires have been grown on stainless steel substrates by high-temperature chemical vapor deposition with the use of Mo metal. The detailed physical and chemical growth processes regarding the formation of the nanowires have been investigated using mass spectroscopy, thermogravimetry, and differential scanning calorimetry analysis, as well as structure analysis by electron microscopy. In reference to Gibbs energy calculation, our study reveals that the growth relies on the decomposition of MoO2 vapors through condensation of its vapor at high substrate temperatures. The aligned growth is a result of competing growth with the nanowires normal to the substrate surface reaching the final growth front. The field emission measurement and the vacuum luminescent tube study show that the Mo nanowires have potential application as electron emitters.

20.
PLoS One ; 11(6): e0157530, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27300005

RESUMEN

BACKGROUND: Global literature has suggested a negative impact of acculturative stress on both physical and mental health among international migrants. In China, approximately 20 percent of its population is rural-to-urban migrant workers and there are significant cultural differences between rural and urban societies, but no data are available regarding the acculturative stress of Chinese migrant workers. This study aimed to explore the forms and contexts of acculturative stress among Chinese migrant workers. METHODS: Qualitative data were collected from four focus group discussions with 17 Chinese rural-to-urban migrant workers and three individual interviews with three medical professionals who provided mental health services for factory-workers in Shenzhen, China. RESULTS: The data in the current study showed that rural-to-urban migrant workers in China had experienced various forms of acculturative stress including difficulties in adapting to the environment, work-related stress, family-related stress, financial hardship, and lack of sense of belonging to cities. CONCLUSION: Rural-to-urban migration in China is a challenging transition with significant acculturative stress and demands for major adjustments among migrant workers. The assessment and management of acculturative stress is a necessary first step in providing mental health services to migrant workers.


Asunto(s)
Aculturación , Dinámica Poblacional , Estrés Psicológico/epidemiología , Adulto , China/epidemiología , Femenino , Humanos , Masculino , Salud Mental , Aislamiento Social , Factores Socioeconómicos , Adulto Joven
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