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1.
Small ; 20(28): e2310857, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38349039

RESUMO

Photocatalytic oxidative coupling of CH4 (OCM) is a promising CH4 conversion process that can achieve efficient methane conversion with the assistance of O2. It remains to be highly challenging to improve the photocatalytic OCM activity from catalyst design and to deepen the understanding of the reactant activation in the OCM process. In this work, the Au-loaded ZnAl-layered double hydroxides (LDHs) with and without oxygen vacancy are constructed (denoted as Au/ZnAl and Au/ZnAl-v), respectively. When applied for photocatalytic OCM, the Au/ZnAl-v shows a CH4 conversion rate of 8.5 mmol g-1 h-1 with 92% selectivity of C2H6 at 40 °C, outperforming most reported photocatalytic OCM systems at low temperature reported in the literature. Furthermore, the catalytic performance of Au/ZnAl-v can be stable for 100 h. In contrast, the An/ZnAl exhibits a CH4 conversion rate of 0.8 mmol g-1 h-1 with 46% selectivity of C2H6. Detailed characterizations and DFT calculation studies reveal that the introduced Ov sites on Au/ZnAl-v are able to activate O2, and the resulting superoxide radical O2·- greatly promotes the activation of CH4. The coupling of CH3· groups with the assistance of Au cocatalyst leads to the formation of C2H6 with high photocatalytic activity.

2.
Small ; 20(19): e2307975, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38098446

RESUMO

Electrochemical methanol oxidation reaction (MOR) is regarded as a promising pathway to obtain value-added chemicals and drive cathodic H2 production, while the rational design of catalyst and in-depth understanding of the structure-activity relationship remains challenging. Herein, the ultrathin NiV-LDH (u-NiV-LDH) with abundant defects is successfully synthesized, and the defect-enriched structure is finely determined by X-ray adsorption fine structure etc. When applied for MOR, the as-prepared u-NiV-LDH presents a low potential of 1.41 V versus RHE at 100 mA cm-2, which is much lower than that of bulk NiV-LDH (1.75 V vs RHE) at the same current density. The yield of H2 and formate is 98.2% and 88.1% as its initial over five cycles and the ultrathin structure of u-NiV-LDH can be well maintained. Various operando experiments and theoretical calculations prove that the few-layer stacking structure makes u-NiV-LDH free from the interlayer hydrogen diffusion process and the hydrogen can be directly detached from LDH laminate. Moreover, the abundant surface defects upshift the d-band center of u-NiV-LDH and endow a higher local methanol concentration, resulting in an accelerated dehydrogenation kinetics on u-NiV-LDH. The synergy of the proton detachment from the laminate and the methanol dehydrogenation oxidation contributes to the excellent MOR performance of u-NiV-LDH.

3.
BMC Cardiovasc Disord ; 24(1): 443, 2024 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-39180009

RESUMO

BACKGROUND: Cardiovascular diseases (CVDs) pose a significant threat to public health. Evidence indicates that the combination of central obesity and normal body mass index (BMI) is associated with an increased risk of cardiovascular disease and mortality. However, limited evidences exists in middle aged and elderly adults in China. METHODS: This was a prospective cohort study that utilized a nationally representative sample of 6,494 adults aged 45 years and above. These individuals participated in the China Health and Retirement Longitudinal Study spanning from 2011 to 2018. Height, weight and waist circumference (WC) were measured, and BMI was calculated by height and weight. Other variables were obtained through self-reported questionnaires. Association analysis was conducted using Cox proportional hazard regression models. RESULTS: A total of 10,186 participants were investigated, with 57,185 person-years of follow-up. During this period, 1,571 CVDs occurred, including 1,173 heart diseases and 527 strokes. After adjusting for various factors including age, gender, education, marital status, smoking status, alcohol intake, social activity, hypertension, dyslipidemia, diabetes, cancer, chronic lung diseases, liver disease, kidney disease, digestive disease, ENP(emotional, nervous, or psychiatric problems), memory related disease, arthritis or rheumatism, asthma, self-rated health and depression, the results revealed that compared to those with normal WC normal body mass index (BMI), individuals with central obesity normal BMI had a 27.9% higher risk of CVD incidence (95% confidence interval [CI]:1.074-1.524), and a 33.4% higher risk of heart disease incidence (95% CI:1.095-1.625), while no significant association was found with stroke. Additionally, those with normal WC high BMI showed a 24.6% higher risk of CVD incidence (95% CI:1.046-1.483), and a 29.1% higher risk of heart disease incidence (95% CI:1.045-1.594), again with no significant association with stroke. Finally, individuals with central obesity high BMI exhibited a 49.3% higher risk of CVD incidence (95% CI:1.273-1.751), a 61% higher risk of heart disease incidence (95% CI:1.342-1.931), and a 34.2% higher risk of stroke incidence (95% CI:1.008-1.786). Age- and sex- specific analyses further revealed varying trends in these associations. CONCLUSIONS: We discovered that the combined association of body mass index(BMI) and central obesity with CVD incidence exhibited a significantly enhanced predictive value. Specifically, a high BMI with central obesity was notably linked to an increased risk of CVD incidence. Additionally, central obesity with a normal BMI or a normal WC coupled with a high BMI significantly augmented the risk of heart disease incidence, but not stroke. Notably, male and middle-aged adults demonstrated a greater propensity for heart disease incidence. Our study underscores the importance of maintaining an optimal BMI and preventing abdominal obesity in promoting cardiovascular health.


Assuntos
Índice de Massa Corporal , Doenças Cardiovasculares , Obesidade Abdominal , Humanos , Masculino , Feminino , Estudos Prospectivos , Pessoa de Meia-Idade , China/epidemiologia , Obesidade Abdominal/epidemiologia , Obesidade Abdominal/diagnóstico , Idoso , Medição de Risco , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/diagnóstico , Fatores Etários , Fatores de Risco , Incidência , Fatores de Tempo , Prognóstico
4.
Small ; 19(21): e2300581, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36823447

RESUMO

Electrocatalytic reduction of CO2 to high-value-added chemicals provides a feasible path for global carbon balance. Herein, the fabrication of NiNP x @NiSA y -NG (x,y = 1, 2, 3; NG = nitrogen-doped graphite) is reported, in which Ni single atom sites (NiSA ) and Ni nanoparticles (NiNP ) coexist. These NiNP x @NiSA y -NG presented a volcano-like trend for maximum CO Faradaic efficiency (FECO ) with the highest point at NiNP2 @NiSA2 -NG in CO2 RR. NiNP2 @NiSA2 -NG exhibited ≈98% of maximum FECO and a large current density of -264 mA cm-2 at -0.98 V (vs. RHE) in the flow cell. In situ experiment and density functional theory (DFT) calculations confirmed that the proper content of NiSA and NiNP balanced kinetic between proton-feeding and CO2 hydrogenation. The NiNP in NiNP2 @NiSA2 -NG promoted the formation of H* and reduced the energy barrier of *CO2 hydrogenation to *COOH, and CO desorption can be efficiently facilitated by NiSA sites, thereby resulting in enhanced CO2 RR performance.

5.
Small ; 19(41): e2303420, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37312653

RESUMO

Direct and selective oxidation of benzene to phenol is a long-term goal in industry. Although great efforts have been made in homogenous catalysis, it still remains a huge challenge to drive this reaction via heterogeneous catalysts under mild conditions. Herein, a single-atom Au loaded MgAl-layered double hydroxide (Au1 -MgAl-LDH) with a well-defined structure, in which the Au single atoms are located on the top of Al3+ with Au-O4 coordination as revealed by extended x-ray-absorption fine-structure (EXAFS)and density-functional theory (DFT)calculation is reported. The photocatalytic results prove the Au1 -MgAl-LDH is capable of driving benzene oxidation reaction with O2 in water, and exhibits a high selectivity of 99% for phenol. While contrast experiment shows a ≈99% selectivity for aliphatic acid with Au nanoparticle loaded MgAl-LDH (Au-NP-MgAl-LDH). Detailed characterizations confirm that the origin of the selectivity difference can be attributed to the profound adsorption behavior of substrate benzene with Au single atoms and nanoparticles. For Au1 -MgAl-LDH, single Au-C bond is formed in benzene activation and result in the production of phenol. While for Au-NP-MgAl-LDH, multiple AuC bonds are generated in benzene activation, leading to the crack of CC bond.

6.
Angew Chem Int Ed Engl ; 62(45): e202311696, 2023 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-37711060

RESUMO

The key issue in the 5-hydroxymethylfurfural oxidation reaction (HMFOR) is to understand the synergistic mechanism involving the protons deintercalation of catalyst and the adsorption of the substrate. In this study, a Pd/NiCo catalyst was fabricated by modifying Pd clusters onto a Co-doped Ni(OH)2 support, in which the introduction of Co induced lattice distortion and optimized the energy band structure of Ni sites, while the Pd clusters with an average size of 1.96 nm exhibited electronic interactions with NiCo support, resulting in electron transfer from Pd to Ni sites. The resulting Pd/NiCo exhibited low onset potential of 1.32 V and achieved a current density of 50 mA/cm2 at only 1.38 V. Compared to unmodified Ni(OH)2 , the Pd/NiCo achieved an 8.3-fold increase in peak current density. DFT calculations and in situ XAFS revealed that the Co sites affected the conformation and band structure of neighboring Ni sites through CoO6 octahedral distortion, reducing the proton deintercalation potential of Pd/NiCo and promoting the production of Ni3+ -O active species accordingly. The involvement of Pd decreased the electronic transfer impedance, and thereby accelerated Ni3+ -O formation. Moreover, the Pd clusters enhanced the adsorption of HMF through orbital hybridization, kinetically promoting the contact and reaction of HMF with Ni3+ -O.

7.
J Am Chem Soc ; 144(5): 2171-2178, 2022 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-34995077

RESUMO

The coordinated configuration of atomic platinum (Pt) has always been identified as an active site with high intrinsic activity for hydrogen evolution reaction (HER). Herein, we purposely synthesize single vacancies in a carbon matrix (defective graphene) that can trap atomic Pt to form the Pt-C3 configuration, which gives exceptionally high reactivity for HER in both acidic and alkaline solutions. The intrinsic activity of Pt-C3 site is valued with a turnover frequency (TOF) of 26.41 s-1 and mass activity of 26.05 A g-1 at 100 mV, respectively, which are both nearly 18 times higher than those of commercial 20 wt % Pt/C. It is revealed that the optimal coordination Pt-C3 has a stronger electron-capture ability and lower Gibbs free energy difference (ΔG), resulting in promoting the reduction of adsorbed H+ and the acceleration of H2 desorption, thus exhibiting the extraordinary HER activity. This work provides a new insight on the unique coordinated configuration of dispersive atomic Pt in defective C matrix for superior HER performance.

8.
Small ; 18(40): e2203787, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36058649

RESUMO

The conversion of CO2 into high-value added chemicals driven by solar energy is an effective way to solve environmental problems, which is, however, largely restricted by the competition reaction of the hydrogen evolution reaction (HER) and easy electron-hole recombination, etc. Herein, VO4 -supported ultrathin NiMgV-layered double hydroxide (V/NiMgV-LDH) nanosheets are successfully fabricated, and the extended X-ray absorption fine structure (EXAFS) and density function theory (DFT) calculations reveal that VO4 species are located on the top of V atoms in the NiMgV-LDH laminate. The V/NiMgV-LDH is proved to be highly efficient for the photocatalytic CO2 reduction reaction (CO2 PR) with high selectivity of 99% for C1 products and nearly no HER (<1%) takes place under visible light. Contrast experiments using NiMgV-LDH as the catalyst for CO2 PR show a CO selectivity of 71.40% and a H2 selectivity of 28.11%. Such excellent performance of V/NiMgV-LDH can be attributed to the following reasons: 1) the V/NiMgV-LDH modulates the band structure and promotes the separation of electrons and holes; 2) strong bonding between V/NiMgV-LDH and CO* and H* facilitates the hydrogenation to form CH4 and inhibits the formation of by-product H2 at the same time.

9.
Small ; 18(35): e2202334, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35934816

RESUMO

To realize excellent selectivity of CH4 in CO2 photoreduction (CO2 PR) is highly desirable, yet which is challenging due to the limited active sites for CH4 generation and severe electron-hole recombination on photocatalysts. Herein, based on the theoretically calculated effects of vanadium incorporation into the laminate of layered double hydroxides (LDHs), V into NiAl-LDH to synthesize a series of LDHs with various V contents is introduced. NiV-LDH is revealed to afford a high CH4 selectivity (78.9%), and extremely low H2 selectivity (only 0.4%) under λ > 400 nm irradiation. By further tuning the molar ratio of Ni to V, a CH4 selectivity of as high as 90.1% is achieved on Ni4 V-LDH, and H2 is completely prohibited on Ni2 V-LDH. Fine structural characterizations and comprehensive optical and electrochemical studies uncover V incorporation creates the lower-valence Ni species as active sites for generating CH4 , and enhances the generation, separation, and transfer of photogenerated carriers.

10.
Chemistry ; 28(6): e202103601, 2022 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-34873760

RESUMO

The low-cost, high-abundance and durable layered double hydroxides (LDHs) have been considered as promising electrocatalysts for oxygen evolution reaction (OER). However, the easy agglomeration of lamellar LDHs in the aqueous phase limits their practical applications. Herein, a series of ternary NiCoFe LDHs were successfully fabricated on nickel foam (NF) via a simple electrodeposition method. The as-prepared Ni(Co0.5 Fe0.5 )/NF displayed an unique nanoarray structural feature. It showed an OER overpotential of 209 mV at a current density of 10 mA cm-2 in alkaline solution, which was superior to most systems reported so far. As evidenced by the XPS and XAFS results, such excellent performance of Ni(Co0.5 Fe0.5 )/NF was attributed to the higher Co3+ /Co2+ ratio and more defects exposed, comparing with Ni(Co0.5 Fe0.5 )-bulk and Ni(Co0.5 Fe0.5 )-mono LDHs prepared by conventional coprecipitation method. Furthermore, the ratio of Co to Fe could significantly tune the Co electronic structure of Ni(Cox Fe1-x )/NF composites (x=0.25, 0.50 and 0.75) and affect the electrocatalytic activity for OER, in which Ni(Co0.5 Fe0.5 )/NF showed the lowest energy barrier for OER rate-determining step (from O* to OOH*). This work proposes a facile method to develop high-efficiency OER electrocatalysts.

11.
Global Health ; 17(1): 86, 2021 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-34321024

RESUMO

INTRODUCTION: Suboptimal health status (SHS), an intermediate state between chronic disease and health, is characterized by chronic fatigue, non-specific pain, headaches, dizziness, anxiety, depression, and functional system disorders with a high prevalence worldwide. Although some lifestyle factors (e.g. smoking, alcohol consumption, physical exercise) and environmental factors (e.g. air quality, noise, living conditions) have already been studied, few studies can comprehensively illustrate the associations of lifestyle and environment factors with general, physical, mental, and social SHS. METHODS: A cross-sectional study was conducted among 6750 urban residents aged 14 years or over in five random cities from September 2017 to September 2018 through face-to-face questionnaires. There were 5881 valid questionnaires with a response rate of 87%. A general linear model and structural equation model were developed to quantify the effects of lifestyle behaviors and environment factors on SHS. RESULTS: The detection rates of general, physical, mental, and social SHS were 66.7, 67.0, 65.5, and 70.0%, respectively. Good lifestyle behaviors and favorable environment factors positively affected SHS (P < 0.001). Lifestyle behaviors had the largest effect on physical SHS (ß = - 0.418), but the least on social SHS (ß = - 0.274). Environment factors had the largest effect on mental SHS (ß = 0.286), but the least on physical SHS (ß = 0.225). CONCLUSIONS: Lifestyle behaviors and environment factors were important influencing factors of SHS. Physical SHS was more associated with lifestyle. Lifestyle and environment were similarly associated with mental and social SHS.


Assuntos
Nível de Saúde , Estilo de Vida , China/epidemiologia , Estudos Transversais , Humanos , Inquéritos e Questionários
12.
Int J Equity Health ; 18(1): 129, 2019 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-31426808

RESUMO

BACKGROUND: Hierarchical medical systems are common in developed countries, but it's not optimistic in China. This study aimed to identify the factors affecting healthcare-seeking behavior among pregnant women in Guangdong, China. METHODS: We conducted a cross-sectional, observational survey, developed using the Andersen's behavioral model. Pregnant women were randomly selected using a two-stage, stratified, random sampling method from hospitals in Guangdong, China. A multinomial logistic regression was used to identify statistically significant variables from aspect of environmental, demographic and pregnancy characteristics associated with pregnant women seeking healthcare at primary, secondary or tertiary hospitals. RESULTS: A total of 1393 pregnant women returned the survey after attending 1 of 12 hospitals within 4 cities of the Guangdong province: 537 (38.5%) of the respondents attended a primary hospital, 437 (31.4%) a secondary hospital, and 419 (30.1%) a tertiary hospital. Women attending primary hospitals were more likely to live closer to the hospital, live rurally, and be educated to a lower level. Several factors were significantly associated with attendance at a secondary vs a primary hospital: the woman's perceived necessity to seek maternal healthcare (OR 1.73, 95% CI [1.1,2.74]), the woman's choice of delivery hospital (OR 1.45, 95% CI [1.01,2.07]), or urban living (OR 1.39, 95% CI [1.03,1.88]). Characteristics associated with attendance at a tertiary vs a primary hospital were: a history of pregnancy complications (OR 2.35, 95% CI [1.43,3.86]), travel to the hospital by public transport/taxi (OR 2.09/2.67, 95% CI [1.35,3.22]/ [1.45,4.92]), urban living (OR 1.58, 95% CI [1.14,2.18]), or a planned current pregnancy (OR 1.53, 95% CI [1.07,2.19]). CONCLUSION: Medical needs and convenience both play a role in the choice of hospital for antenatal care, and impact on equity utilization of health services. Pregnant women without risk factors and with higher levels of education should be a target population for guiding to choose a more proper level of hospital.


Assuntos
Comportamento de Escolha , Atenção à Saúde , Hospitais , Serviços de Saúde Materna , Aceitação pelo Paciente de Cuidados de Saúde , Gestantes , Adolescente , Adulto , China , Estudos Transversais , Parto Obstétrico , Escolaridade , Feminino , Equidade em Saúde , Humanos , Modelos Logísticos , Gravidez , Complicações na Gravidez , População Rural/estatística & dados numéricos , Inquéritos e Questionários , Meios de Transporte , Viagem , População Urbana , Adulto Jovem
13.
BMC Psychiatry ; 19(1): 85, 2019 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-30836983

RESUMO

BACKGROUND: Depression and anxiety are prevalent and associated with a worse prognosis in coronary heart disease (CHD) patients. However, the influence of disease severity on mood symptoms is unknown. The specific associations of mood symptoms with NYHA classes remain unexplored. METHODS: In this cross-sectional study, 443 consecutive inpatients with angina pectoris (AP) confirmed by angiography were included into analysis. Somatic and cognitive symptom scores derived from Patient Health Questionnaire (PHQ-9) and Generalized Anxiety Disorder Scale (GAD-7) were used to assess mood symptoms. Predictors for depression and anxiety with strict and lax standards were compared. We hypothesized NYHA classification to be an indicator of disease severity through analyses with clinical features using ordinal logistic model. Applying both binary and ordinal logistic models, we evaluated the associations of mood symptoms with NYHA classes. RESULTS: Discrepancy of disease severity existed between the depressed and nondepressed. NYHA classification was proved to be an integrated index under influence of age, coronary stenosis, heart failure and diabetes. NYHA class I and II individuals with AP were at equivalent risk for depression (NYHA II vs I: binary model OR 1.32 (0.59,2.96), p = 0.50; ordinal model OR 1.17 (0.73,1.88), p = 0.52), however NYHA class III/IV patients shared a sharply higher risk (NYHA III/IV vs I: binary model OR 3.32 (1.28,8.61), p = .013; ordinal model OR 3.94 (2.11,7.36), p < .001). Analyses on somatic and cognitive depressive symptoms confirmed this finding and hinted a greater impact of education background on mood when patient's condition is unstable. Anxiety seemed in the whole picture irrelevant with NYHA classes. Comparing with NYHA class I/II, AP patients in NYHA class III/IV tended to be less anxious. However, when CHD became unstable, the calmness may immediately be broken up. A great distinction of the ratio of anxiety and depression symptom scores between NYHA class III/IV stable and unstable AP patients (p = .018) was observed. CONCLUSIONS: Mood symptoms in CHD patients are to a great extend derived from disease itself. Only for patients with relatively serious physical condition, unexpected discomforts caused by disease notably impact the emotions. Education background tends to influence the mood especially when disease is still unstable.


Assuntos
Angina Pectoris/psicologia , Ansiedade/psicologia , Insuficiência Cardíaca/psicologia , Índice de Gravidade de Doença , Idoso , Angina Pectoris/epidemiologia , Ansiedade/epidemiologia , Estudos Transversais , Depressão/epidemiologia , Depressão/psicologia , Feminino , Insuficiência Cardíaca/epidemiologia , Humanos , Pacientes Internados , Masculino , Pessoa de Meia-Idade , Prevalência
14.
Nanoscale Adv ; 6(9): 2363-2370, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38694473

RESUMO

Herein, we report the successful fabrication of a series of transition metal doped Ni nanoparticles (NPs) coordinated with Ni single atoms in nitrogen-doped carbon nanotubes (denoted as Ni1+NPsM-NCNTs, M = Mn, Fe, Co, Cu and Zn; Ni1 = Ni single atom). X-ray absorption fine structure reveals the coexistence of Ni single atoms with Ni-N4 coordination and NiM NPs. When applied for electrocatalytic CO2RR, the Ni1+NPsM-NCNT compounds show the Faradaic efficiency of CO (FECO) with a volcano-like tendency of Mn < Fe ≈ Co < Zn < Cu, in which the Ni1+NPsCu-NCNT exhibits the highest FECO of 96.92%, a current density of 171.25 mA cm-2 and a sustainable stability over 24 hours at a current density of 100 mA cm-2, outperforming most reported examples in the literature. Detailed experiments and theoretical calculations reveal that for Ni1+NPsCu-NCNTs, the electron transfer from NiCu NPs to Ni single atoms strengthens the adsorption of *COOH intermediates. Moreover, the d-band center of Ni-N in Ni1+NPsCu-NCNT is upshifted, providing stronger binding with the reaction intermediates of *COOH, whereas the NiCu NPs increase the Gibbs free energy change of the Volmer step, suppressing the competitive HER.

15.
ACS Appl Mater Interfaces ; 15(29): 34497-34504, 2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37439628

RESUMO

Prion disorders are a group of lethal infectious neurodegenerative diseases caused by the spontaneous aggregation of misfolded prion proteins (PrPSc). The oxidation of such proteins by chemical reagents can significantly modulate their aggregation behavior. Herein, we exploit a series of vanadium-substituted Keggin-type tungsten and molybdenum POMs (W- and Mo-POMs) as chemical tools to oxidize PrP106-126 (denoted as PrP), an ideal model for studying PrPSc. Due to the band gaps being larger than that of Mo-POMs, W-POMs possess higher structural stability and show stronger binding and oxidation effect on PrP. Additionally, the substitution of W/Mo by vanadium elevates the local electron distribution on the bridged O(26) atom, thereby strengthening the hydrogen bonding of POMs with the histidine site. Most importantly, with the number of substituted vanadium increases, the LUMO energy level of POMs decreases, making it easier to accept electrons from methionine. As a result, PW10V2 displays the strongest oxidation on the methionine residue of PrP, leading to an excellent inhibitory effect on PrP aggregation and a significant attenuation on its neurotoxicity.


Assuntos
Proteínas Priônicas , Príons , Príons/química , Príons/metabolismo , Vanádio , Metionina/química , Racemetionina
16.
Nanoscale ; 15(28): 11867-11874, 2023 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-37395470

RESUMO

Introducing different active sites into heterogeneous catalysts provides new prospects to address the challenges in single-atom catalysis. Herein, the Au single atoms together and the Au nanoparticles were loaded onto NiAl-LDH by a facile impregnation-reduction method for the first time, resulting in the formation of Au1+n-NiAl-LDH, in which abundant Au single atoms are located around the Au nanoparticles with ∼5 nm size. When applied in the electrocatalytic benzyl alcohol oxidation reaction (BAOR), the as-prepared Au1+n-NiAl-LDH exhibits a remarkable selectivity of 91% and 177.63 µmol for benzaldehyde in 5 hours, while in contrast examples using solely Au single atom loaded NiAl-LDH (Au1-NiAl-LDH) and solely Au nanoparticle loaded NiAl-LDH (Aun-NiAl-LDH) can only realize 87.36 µmol production (75% selectivity) and 48.90 µmol production (28% selectivity) of benzaldehyde, respectively. Such a dramatic difference can be attributed to the synergistic effects of Au single atoms and Au nanoparticles. DFT calculation results reveal that for Au1+n-NiAl-LDH, Au single atoms promote the dehydrogenation capacity of LDH laminates, while Au nanoparticles offer adsorption sites for the electrophilic attachment of benzyl alcohol.

17.
Aging (Albany NY) ; 13(6): 8204-8213, 2021 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-33686964

RESUMO

OBJECTIVES: The association between weak hand grip strength (HGS) and stroke recovery has been studied; however, few studies focused on the association of HGS with stroke prevalence and incidence. METHODS: A prospective cohort baseline study of a nationally representative sample in Chinese adults aged 45 years and older in 2011 was followed up in 2015. 8871 participants without stroke at baseline were followed. The associations of HGS and its changes with stroke prevalence and incidence were investigated using logistic regression models and Cox proportional hazards regression models. RESULTS: Association of HGS and stroke prevalence was significant. HGS weakness significantly increased risk of stroke incidence, with 89.3% higher risk when compared to normal HGS. During 35,263 person-years of follow-up, 112 stroke patients occurred. The four-year incidence rate ratio of stroke for participants with a HGS weakness was 2.15, compared to normal HGS participants. HGS changes in weakness/weakness from 2011 to 2015(D-HGS) and normal/weakness D-HGS had higher risks of stroke incidence when compared with those who had normal/normal D-HGS. CONCLUSIONS: HGS weakness and decline of HGS were associated with stroke incidence for adults aged 45 years and older in China.


Assuntos
Força da Mão , Acidente Vascular Cerebral/epidemiologia , Idoso , China/epidemiologia , Estudos de Coortes , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
18.
Nanoscale ; 13(3): 1869-1874, 2021 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-33439208

RESUMO

Noble metal-based catalysts have attracted huge attention owing to their intriguing activity and selectivity. Revealing noble metal active sites and keeping them in a form of stable and high loading are crucial to improving the catalytic performance and understanding the reaction mechanism. Herein, a feasible preparation method was used to synthesize a Rh-based ultrathin NiFe layered double hydroxide (Rh/NiFe). The detailed study proved that the existence form of Rh atoms is atomically dispersed. Moreover, extended X-ray absorption fine structure (EXAFS) with theoretical calculation of X-ray absorption near-edge structure (XANES) and density functional theory (DFT) were used to identify at the atomic level the precise location and coordination environment of the introduced Rh atoms. It was found that Rh atoms are doped in the LDH layer in a coplanar position with Ni and Fe atoms. With a 5.4 wt% loading amount of Rh, the modified catalyst of Rh/NiFe-5.4 requires 80 mV less than unmodified ultrathin NiFe layered double hydroxide (NiFe) for hydrazine electrooxidation. The XAFS fitting revealed that the doping of Rh atoms results in the distortion of the laminate and then introduces certain defects, which may be attributed to electron transport, thus endowing them with exceptional electrocatalytic performance.

19.
J Affect Disord ; 260: 11-17, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31493632

RESUMO

BACKGROUND: Association of cardiovascular disease (CVD) or depression and memory has been studied. But hardly any studies on the association of coexistence of CVD and depression and memory. METHODS: This is a prospective cohort study of a nationally representative sample of 12,272 adults aged 45 years and more who participated in the China health and retirement longitudinal study 2011 to 2015. All Variables were acquired by self-reporting questions. The associations between coexistence of CVD and depression with memory related disease (MRD) were investigated by using Cox proportional hazards regression models. RESULTS: Among the 12,272 participants (mean age 65.69 years; 46.8% male) in this study, 56.9% no CVD or depression and 6.7% coexistence of CVD and depression. After adjustment for age, sex, marriage, living place, registered permanent residence, education level, smoking status, alcoholic intake, sleep status, nap status, social communication, health before 15 years, life satisfaction, cognitive function, and 11 chronic diseases risk factors, depression alone was significantly high risk for MRD (HR:1.64; 95% CI: 1.09-2.49); coexistence of CVD and depression increased the risk for MRD significantly higher (HR: 4.72; 95%CI: 2.91-7.64). LIMITATIONS: Diseases were all self-reported and we couldn't adjust for all the potential confounders, which might be prone to information error and residual confounding. CONCLUSIONS: In a nationally representative cohort with median 4 years of follow-up, depression alone and coexistence of depression and CVD could significantly increase the risk of MRD. Our study supports the idea of prevention of memory disease from a psycho-cardiology aspect.


Assuntos
Doenças Cardiovasculares/psicologia , Depressão/psicologia , Transtornos da Memória/epidemiologia , Idoso , Doenças Cardiovasculares/epidemiologia , China/epidemiologia , Depressão/epidemiologia , Feminino , Humanos , Estudos Longitudinais , Masculino , Transtornos da Memória/complicações , Transtornos da Memória/psicologia , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Prospectivos , Aposentadoria/psicologia , Aposentadoria/estatística & dados numéricos , Fatores de Risco
20.
J Affect Disord ; 266: 187-193, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32056875

RESUMO

BACKGROUND: Association of cardiovascular disease (CVD) or depression and memory has been studied. But hardly any studies on the association of coexistence of CVD and depression and memory. METHODS: This is a prospective cohort study of a nationally representative sample of 12,272 adults aged 45 years and more who participated in the China health and retirement longitudinal study 2011 to 2015. All variables were acquired by self-reporting questions. The associations between coexistence of CVD and depression with memory related disease (MRD) were investigated by using Cox proportional hazards regression models. RESULTS: Among the 12,272 participants (mean age 65.69 years; 46.8% male) in this study, 56.9% no CVD or depression and 6.7% coexistence of CVD and depression. After adjustment for age, sex, marriage, living place, registered permanent residence, education level, smoking status, alcoholic intake, sleep status, nap status, social communication, health before 15 years, life satisfaction, cognitive function, and 11 chronic diseases risk factors, depression alone was significantly high risk for MRD (HR:1.64; 95% CI: 1.09-2.49); coexistence of CVD and depression increased the risk for MRD significantly higher (HR: 4.72; 95%CI: 2.91-7.64). LIMITATIONS: Diseases were all self-reported and we couldn't adjust for all the potential confounders, which might be prone to information error and residual confounding. CONCLUSIONS: In a nationally representative cohort with median 4 years of follow-up, depression alone and co-existence of depression and CVD could significantly increase the risk of MRD. Our study supports the idea of prevention of memory disease from a psycho-cardiology aspect.


Assuntos
Doenças Cardiovasculares , Adolescente , Adulto , Idoso , Doenças Cardiovasculares/epidemiologia , China/epidemiologia , Estudos de Coortes , Depressão/epidemiologia , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Prospectivos , Fatores de Risco
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