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1.
Ann Intern Med ; 177(6): 719-728, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38801778

RESUMO

BACKGROUND: Observational studies suggest that voluntary medical male circumcision (VMMC) may lower HIV risk among men who have sex with men (MSM). A randomized controlled trial (RCT) is needed to confirm this. OBJECTIVE: To assess the efficacy of VMMC in preventing incident HIV infection among MSM. DESIGN: An RCT with up to 12 months of follow-up. (Chinese Clinical Trial Registry: ChiCTR2000039436). SETTING: 8 cities in China. PARTICIPANTS: Uncircumcised, HIV-seronegative men aged 18 to 49 years who self-reported predominantly practicing insertive anal intercourse and had 2 or more male sex partners in the past 6 months. INTERVENTION: VMMC. MEASUREMENTS: Rapid testing for HIV was done at baseline and at 3, 6, 9, and 12 months. Behavioral questionnaires and other tests for sexually transmitted infections were done at baseline, 6 months, and 12 months. The primary outcome was HIV seroconversion using an intention-to-treat analysis. RESULTS: The study enrolled 124 men in the intervention group and 123 in the control group, who contributed 120.7 and 123.1 person-years of observation, respectively. There were 0 seroconversions in the intervention group (0 infections [95% CI, 0.0 to 3.1 infections] per 100 person-years) and 5 seroconversions in the control group (4.1 infections [CI, 1.3 to 9.5 infections] per 100 person-years). The HIV hazard ratio was 0.09 (CI, 0.00 to 0.81; P = 0.029), and the HIV incidence was lower in the intervention group (log-rank P = 0.025). The incidence rates of syphilis, herpes simplex virus type 2, and penile human papillomavirus were not statistically significantly different between the 2 groups. There was no evidence of HIV risk compensation. LIMITATION: Few HIV seroconversions and limited follow-up period. CONCLUSION: Among MSM who predominantly practice insertive anal intercourse, VMMC is efficacious in preventing incident HIV infection; MSM should be included in VMMC guidelines. PRIMARY FUNDING SOURCE: The National Science and Technology Major Project of China.


Assuntos
Circuncisão Masculina , Infecções por HIV , Homossexualidade Masculina , Humanos , Masculino , Adulto , Infecções por HIV/prevenção & controle , Infecções por HIV/epidemiologia , Adulto Jovem , Adolescente , Pessoa de Meia-Idade , China/epidemiologia , Incidência , Comportamento Sexual , Análise de Intenção de Tratamento
2.
Nano Lett ; 23(4): 1211-1218, 2023 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-36748951

RESUMO

Interfacial atomic configuration and its evolution play critical roles in the structural stability and functionality of mixed zero-dimensional (0D) metal nanoparticles (NPs) and two-dimensional (2D) semiconductors. In situ observation of the interface evolution at atomic resolution is a vital method. Herein, the directional migration and structural evolution of Au NPs on anisotropic ReS2 were investigated in situ by aberration-corrected transmission electron microscopy. Statistically, the migration of Au NPs with diameters below 3 nm on ReS2 takes priority with greater probability along the b-axis direction. Density functional theory calculations suggest that the lower diffusion energy barrier enables the directional migration. The coalescence kinetics of Au NPs is quantitatively described by the relation of neck radius (r) and time (t), expressed as r2=Kt. Our work provides an atomic-resolved dynamic analysis method to study the interfacial structural evolution of metal/2D materials, which is essential to the study of the stability of nanodevices based on mixed-dimensional nanomaterials.

3.
Nano Lett ; 23(23): 11360-11367, 2023 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-38010863

RESUMO

The crystal growth kinetics is crucial for the controllable preparation and performance modulation of metal nanocrystals (NCs). However, the study of growth mechanisms is significantly limited by characterization techniques, and it is still challenging to in situ capture the growth process. Real-time and real-space imaging techniques at the atomic scale can promote the understanding of microdynamics for NC growth. Herein, the growth of Pd NCs on monolayer MoS2 under different atmospheres was in situ studied by environmental transmission electron microscopy. Introducing carbon monoxide can modulate the diffusion of Pd monomers, resulting in the epitaxial growth of Pd NCs with a uniform orientation. The electron energy loss spectroscopy and theoretical calculations showed that the CO adsorption assured the specific exposed facets and good uniformity of Pd NCs. The insight into the gas-solid interface interaction and the microscopic growth mechanism of NCs may shed light on the precise synthesis of NCs on two-dimensional (2D) materials.

4.
J Med Virol ; 95(2): e28567, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36786385

RESUMO

Men who have sex with men (MSM) have been recommended for targeted monkeypox vaccination. We aimed to investigate monkeypox awareness and explore the correlates of monkeypox vaccination hesitancy among MSM in China. We conducted a cross-sectional survey from August 10 to September 9, 2022. Awareness related to monkeypox and attitude toward monkeypox vaccination among MSM aged ≥18 years were collected. Multivariable logistic regression was applied to evaluate correlates of vaccination hesitancy. The discrepancy in awareness between subgroups regarding HIV status was assessed. A total of 1090 MSM were included (age: median 30 years, interquartile range [IQR], 25-35; HIV-infected: 53.12%). Only 13.85% of respondents expressed high monkeypox vaccination hesitancy. Hesitancy was associated with no fixed income (adjuster odds ratio [aOR], 2.46, 95% confidence interval [CI], 1.48-4.11), infrequent information following (sometimes, 3.01, 1.55-5.83; seldom or never, 5.66, 2.58-12.45), and lack of worries about monkeypox endemic (1.78, 1.11-2.87). Participants who believed that HIV-infected cases accounted for a smaller proportion (1.62, 1.01-2.60), disagreed that monkeypox virus could be detected in semen (2.21, 1.26-3.88), and considered either replication-competent (1.84, 1.14-2.96) or replication-deficient (4.80, 2.26-10.21) monkeypox vaccine unsuitable for HIV-infected people were generally more hesitant. Compared with HIV-uninfected MSM, HIV-infected MSM supported more for vaccination promotion. MSM in China had low hesitancy toward monkeypox vaccination. Safety and affordability of vaccine and availability of information were essential aspects to reduce hesitancy. Education on vaccination benefits should be encouraged to promote future vaccination plans.


Assuntos
Infecções por HIV , Mpox , Minorias Sexuais e de Gênero , Vacina Antivariólica , Masculino , Humanos , Adolescente , Adulto , Homossexualidade Masculina , Estudos Transversais , Hesitação Vacinal , Vacinação , China/epidemiologia
5.
AIDS Care ; 35(5): 634-638, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36223531

RESUMO

Obtaining antiretroviral therapy (ART) was a challenge for people living with HIV (PLHIV) in China during the COVID-19 outbreak. On 26 January 2020, the Chinese Center for AIDS/STD Control and Prevention issued a nationwide directive to relax restrictions on where and when PLHIV could refill ART. This qualitative study explored unexpected barriers under this directive and recommendations to improve future ART delivery. Between February 11 and February 15 2020, in-depth interviews of 4 groups of stake holders related to ART refilling (i.e., PLHIV, community-based organization employees, CDC staff, infectious disease physicians and nurses), were conducted via WeChat. Data were managed by NVivo 11.0 and transcripts were coded using thematic analysis. Sixty-two interviews were conducted. The main barriers to refilling ART included: (1) inconsistent documentation requirements to refill ART, (2) lack of specific protocols on ART refilling, (3) insufficient staffing, and (4) regimen verification and drug shortages. The most common recommendations to improve future ART delivery were: (1) to establish a nationwide system to distribute ART and (2) increase the number of pills delivered with each ART refill. Strengthening protocols and systems to refill ART and improving collaboration is key to preventing interruptions in ART among PLHIV during public health emergencies.


Assuntos
COVID-19 , Infecções por HIV , Humanos , Infecções por HIV/tratamento farmacológico , COVID-19/epidemiologia , Pandemias , Pesquisa Qualitativa , China/epidemiologia , Antirretrovirais/uso terapêutico
6.
Nanotechnology ; 34(36)2023 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-37295408

RESUMO

Formamidinium lead triiodide (FAPbI3) is considered as the prospective light-absorbing layer on account of the close-to-ideal bandgap of theα-phase, wide optical absorption spectrum and good thermal stability. Therefore, how to realizeδtoα-phase transition to obtain phase-pureα-FAPbI3without additives is important for FAPbI3perovskite films. Herein, a homologous post-treatment strategy (HPTS) without additives is proposed to prepare FAPbI3films with pureα-phase. The strategy is processed along with dissolution and reconstruction process during the annealing. The FAPbI3film has tensile strain with the substrate, and the lattice keeps tensile, and the film maintains in anα/δhybrid phase. The HPTS process releases the tensile strain between the lattice and the substrate. The process of strain release realizes the phase transition fromδtoα-phase during this process. This strategy can accelerate the transformation from hexagonalδ-FAPbI3to cubicα-FAPbI3at 120 °C. As a result, the acquiredα-FAPbI3films exhibit better film quality in optical and electrical properties, accordingly achieving device efficiency of 19.34% and enhanced stability. This work explores an effective approach to obtain additive-free and phase-pureα-FAPbI3films through a HPTS to fabricate uniform high-performanceα-FAPbI3perovskite solar cells.


Assuntos
Óxidos , Estudos Prospectivos , Transição de Fase
7.
Arch Sex Behav ; 52(5): 2065-2081, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37296334

RESUMO

Voluntary medical male circumcision (VMMC) may be incorporated into HIV prevention services for men who have sex with men (MSM). We conducted a mixed-methods study to elucidate barriers and facilitators to, and experience of, VMMC among MSM. Participants were MSM aged 18 years and older who were enrolled in an ongoing multicenter randomized controlled trial (RCT) to evaluate VMMC to prevent HIV among MSM in China. RCT participants completed a questionnaire before and after VMMC to assess perceptions of and complications after the procedure. A subset of RCT participants were selected for in-depth interviews. Interviewees answered open-ended questions about barriers and facilitators to and experience of undergoing VMMC. Six-step thematic analysis incorporating inductive and deductive approaches was used to interpret interview responses. A total of 457 MSM completed the pre-VMMC survey, 115 circumcised MSM completed post-VMMC surveys, and 30 MSM completed an interview. Main barriers to VMMC uptake were concerns about pain, length of wound healing, cost, lack of knowledge about or misconceptions of VMMC, and stigma related to surgery. Facilitators to VMMC could be categorized as internal factors (foreskin) and external factors (motivation and follow-up care). Interestingly, the VMMC experiences of others could be transformed from a barrier into a facilitator to VMMC in some circumstances. After VMMC participants transitioned from a negative state of pain, remorse, difficulty sleeping, and discomfort to a positive state of symptom alleviation and personal hygiene improvement. Optimizing facilitators and addressing barriers may encourage VMMC among MSM. Joint efforts should be made by relevant stakeholders to improve the awareness and uptake of VMMC among MSM.


Assuntos
Circuncisão Masculina , Infecções por HIV , Minorias Sexuais e de Gênero , Masculino , Humanos , Infecções por HIV/prevenção & controle , China , Dor
8.
BMC Med ; 20(1): 453, 2022 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-36424628

RESUMO

BACKGROUND: Conteltinib (CT-707) is a potent second-generation anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitor (TKI) showing promising anti-tumor activities in preclinical studies. This study aimed to assess the safety, pharmacokinetic (PK), and efficacy of conteltinib in patients with ALK-positive non-small cell lung cancer (NSCLC). METHODS: In this multicenter, single-arm, open-label, first-in-human phase 1 study, conteltinib was taken orally at doses of 50 to 800 mg quaque die (QD) in a dose-escalation phase. If the response was observed in a dose cohort of the dose-escalation phase, dose expansion was started. The primary endpoints were maximum tolerated dose (MTD), dose-limiting toxicity (DLT), and adverse events assessed by investigators. RESULTS: Between April 13, 2016, and February 8, 2020, 64 ALK-positive NSCLC patients were enrolled, including 41 (64.1%) patients with ALK TKI-naïve and 23 (35.9%) patients who received crizotinib previously. In the dose-escalation phase, 26 patients were treated with conteltinib at doses of 50 mg, 100 mg, 200 mg, 300 mg, 450 mg, 600 mg, and 800 mg QD. One DLT event was reported at the dose of 600 mg. MTD was not reached. Overall, 58 (90.6%) patients experienced treatment-related adverse events (TRAEs) and 9 (14.1%) patients had grade ≥ 3 TRAEs. The most common TRAEs were diarrhea (46 [71.9%]), serum creatinine elevated (29 [45.3%]), aspartate aminotransferase elevated (25 [39.1%]), and nausea (24 [37.5%]). Among 39 ALK TKI-naïve patients, the overall response rate (ORR) was 64.1% (25 of 39; 95% confidence interval [CI], 47.2-78.8), median progression-free survival (PFS) was 15.9 months (95% CI, 9.26-23.3), and median duration of response (DoR) was 15.0 months (95% CI, 9.06-25.8). Among 21 patients who received crizotinib previously, the ORR was 33.3% (7 of 21; 95% CI, 14.6-57.0), median PFS was 6.73 months (95% CI, 4.73-8.54), and median DoR was 6.60 months (95% CI, 3.77-13.3). CONCLUSIONS: In this study, conteltinib showed manageable safety profile, favorable PK properties, and anti-tumor activity in advanced ALK-positive NSCLC patients. The recommended phase 2 dose was determined to be 600 mg QD for ALK TKI-naïve patients and 300 mg bis in die (BID) for patients who received crizotinib previously. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02695550.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Crizotinibe/efeitos adversos , Quinase do Linfoma Anaplásico , Neoplasias Pulmonares/patologia , Inibidores de Proteínas Quinases/efeitos adversos , Proteínas Tirosina Quinases
9.
Langmuir ; 38(49): 15384-15393, 2022 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-36448653

RESUMO

Interactions of enzymes with supports significantly affect the activity and stability of immobilized enzymes. Herein, amino-functionalized ionic liquid (IL)-grafted magnetic zeolitic imidazolate framework-90 (MZIF-90) was prepared and used to immobilize porcine pancreatic lipase (PPL). The nanocomposites were fully characterized; meanwhile, the interactions between ILs and ZIF-90 were calculated based on density functional theory. The prepared biocatalyst (PPL-ILs/MZIF-90) had a lipase loading of 178.3 mg/g and hydrolysis activity up to 287.5 U/g. When the biocatalyst was used to synthesize isoamyl acetate, the reaction media, molar ratio of alcohol/acid, temperature, and reaction time were optimized. Under the optimized reaction conditions (in hexane, alcohol/acid = 3:1, under 45 °C, reacted for 9 h), the ester yield reached 85.5%. The results of the stability test showed that PPL-ILs/MZIF-90 retained 88.7% of the initial activity after storing for 35 days and 92.5% of the initial activity after reusing for seven cycles for synthesizing isoamyl acetate. Moreover, the secondary structure analysis showed that the synthesized supports protected the active conformation of immobilized lipase, which lead to the enhanced catalytic performance. Additionally, the biocatalyst can be easily separated with a magnet, which facilitated the reusability. This study provides insights regarding the application of metal organic framework composites in the field of enzyme catalysis.


Assuntos
Enzimas Imobilizadas , Lipase , Suínos , Animais , Lipase/química , Esterificação , Enzimas Imobilizadas/química , Fenômenos Magnéticos , Estabilidade Enzimática
10.
Curr HIV/AIDS Rep ; 19(6): 516-521, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36350470

RESUMO

PURPOSE OF REVIEW: Evidence from clinical trials identified the effectiveness of voluntary medical male circumcision (VMMC) as an additional strategy to reduce the risk of HIV transmission from women to men. However, concerns about post-circumcision sexual risk compensation may hinder the scale-up of VMMC programs. We reviewed the evidence of changes in risky sexual behaviors after circumcision, including condomless sex, multiple sex partners, and early resumption of sex after surgery. RECENT FINDINGS: Most clinical trial data indicate that condomless sex and multiple partners did not increase for men after circumcision, and early resumption of sex is rare. Only one post-trial surveillance reports that some circumcised men had more sex partners after surgery, but this did not offset the effect of VMMC. Conversely, qualitative studies report that a small number of circumcised men had increased risky sexual behaviors, and community-based research reports that more men resumed sex early after surgery. With the large-scale promotion and expansion of VMMC services, it may be challenging to maintain effective sexual health educations due to various restrictions. Misunderstandings of the effect of VMMC in preventing HIV infection are the main reason for increasing risky sexual behaviors after surgery. Systematic and practical sexual health counseling services should be in place on an ongoing basis to maximize the effect of VMMC.


Assuntos
Circuncisão Masculina , Infecções por HIV , Masculino , Feminino , Humanos , Circuncisão Masculina/psicologia , Infecções por HIV/prevenção & controle , Infecções por HIV/epidemiologia , Parceiros Sexuais , Comportamento Sexual/psicologia , Sexo sem Proteção
11.
Bioorg Med Chem Lett ; 75: 128973, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36075370

RESUMO

In the past decade, Wee1 inhibition has received widespread attention as a cancer therapy. Our research aims to discover effective, selective and drug-like Wee1 inhibitors. Herein, a series of compounds with pyrrolo[2,3-d]pyrimidine-based heterocycles were designed, synthesized and confirmed to inhibit Wee1 kinase. The inhibitors afforded good potency in Wee1 Kinase inhibitory activity in enzymatic assays. These compounds showed strong proliferation inhibition against NCI-1299 cell lines and had acceptable pharmacokinetic properties. These derivatives are promising inhibitors that warrant further evaluation, towards the development of potential anticancer drug.


Assuntos
Antineoplásicos , Pirimidinas , Antineoplásicos/farmacologia , Proteínas de Ciclo Celular , Linhagem Celular Tumoral , Inibidores Enzimáticos , Inibidores de Proteínas Quinases/farmacologia , Pirimidinas/farmacologia
12.
Acta Biochim Biophys Sin (Shanghai) ; 54(2): 252-260, 2022 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-35538024

RESUMO

Focal adhesion kinase (FAK), a multi-functional cytoplasmic tyrosine kinase, plays a critical role in cancer migration, proliferation and metastasis via regulating multiple signaling pathways. SY-707 is an anaplastic lymphoma kinase (ALK)/FAK/type 1 insulin-like growth factor receptor (IGF1R) multi-kinase inhibitor which is now being evaluated in phase II clinical trials for ALK positive non-small cell lung cancer (NSCLC). However, the effect of SY-707 on breast cancer is unknown. In this study, we assessed preclinical the anti-growth and anti-metastasis potency of SY-707 in breast cancer cells. ATP content, PE-Annexin V, and would healing assays were used to examine cell proliferation, cell cycle and migration. Then, SD rat and beagle dog models were used to evaluate the pharmacokinetics profile of SY-707, and mouse xenograft model was used to evaluate the anti-cancer activities of SY-707 . We found that breast cancer cells apoptosis were induced by SY-707. Moreover, SY-707 exerted inhibition on cell migration and adhesion in a dose-dependent manner. In T47D xenograft mice, SY-707 had significant anti-tumor activities alone or synergistically with Paclitaxel. Meanwhile, SY-707 also displayed significant suppression on spontaneous metastasis of tumor to the lung in 4T1 murine breast cancer xenograft model. In conclusion, SY-707 has potent anti-proliferation and anti-migration potential in breast cancer and , implying its therapeutic application for the treatment of breast cancer in future clinical trials.


Assuntos
Neoplasias da Mama , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Animais , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células , Cães , Feminino , Proteína-Tirosina Quinases de Adesão Focal , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Camundongos , Metástase Neoplásica , Inibidores de Proteínas Quinases/farmacologia , Ratos , Ratos Sprague-Dawley , Receptor IGF Tipo 1 , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Pharm Biol ; 59(1): 200-208, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33595422

RESUMO

CONTEXT: Rotundic acid (RA), a plant-derived pentacyclic triterpene acid, has been reported to possess extensive pharmacological activities. The poor bioavailability limits its further development and potential clinic application. OBJECTIVE: To clarify the potential mechanism for poor oral bioavailability. MATERIALS AND METHODS: The single-dose pharmacokinetics of orally administered RA (10 mg/kg) in Sprague-Dawley rats without or with verapamil (25 or 50 mg/kg) were investigated. Additionally, MDCKII-MDR1 and Caco-2 cell monolayers, five recombinant human cytochrome P450 (rhCYP) enzymes (1A2, 2C8, 2C9, 2D6 and 3A4), and rat liver microsomes were also conducted to investigate its potential mechanism. RESULTS: Verapamil could significantly affect the plasma concentration of RA. Co-administered verapamil at 25 and 50 mg/kg, the AUC0-∞ increased from 432 ± 64.2 to 539 ± 53.6 and 836 ± 116 ng × h/mL, respectively, and the oral clearance decreased from 23.6 ± 3.50 to 18.7 ± 1.85 and 12.2 ± 1.85 L/h/kg, respectively. The MDCKII-MDR1 cell assay showed that RA might be a P-gp substrate. The rhCYPs experiments indicated that RA was mainly metabolized by CYP3A4. Additionally, verapamil could increase the absorption of RA by inhibiting the activity of P-gp, and slow down the intrinsic clearance of RA from 48.5 ± 3.18 to 12.0 ± 1.06 µL/min/mg protein. DISCUSSION AND CONCLUSIONS: These findings indicated that verapamil could significantly affect the pharmacokinetic profiles of RA in rats. It was demonstrated that P-gp and CYP3A were involved in the transport and metabolism of RA, which might contribute to the low oral bioavailability of RA.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Citocromo P-450 CYP3A/metabolismo , Triterpenos/farmacocinética , Verapamil/farmacologia , Administração Oral , Animais , Área Sob a Curva , Disponibilidade Biológica , Células CACO-2 , Relação Dose-Resposta a Droga , Interações Medicamentosas , Humanos , Masculino , Microssomos Hepáticos/metabolismo , Ratos , Ratos Sprague-Dawley , Triterpenos/administração & dosagem , Verapamil/administração & dosagem
14.
Small ; 15(35): e1901980, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31267654

RESUMO

As one important electrode reaction in electrocatalytic and photoelectrochemical cells for renewable energy circulation, oxygen catalysis has attracted considerable research in developing efficient and cost-effective catalysts. Due to the inevitable formation of oxygenic intermediates on surface sites during the complex reaction steps, the surface structure dynamically evolves toward reaction-preferred active species. To date, transition metal compounds, here defined as TM-Xides, where "X" refers to typical nonmetal elements from group IIIA to VIA, including hydroxide as well, are reported as high-performance oxygen evolution reaction (OER) electrocatalysts. However, more studies observe at least exterior oxidation or amorphization of materials. Thus, whether the TM-Xides can be defined as OER catalysts deserves further discussion. This Review pays attention to recent progress on the surface reconstruction of TM-Xide OER electrocatalysts with an emphasis on the identification of the true active species for OER, and aims at disseminating the real contributors of OER performance, especially under long-duration electrocatalysis.

15.
Small ; 15(9): e1804688, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30677227

RESUMO

Methanol is extremely harmful to human health, since it is oxidized slowly and can accumulate in the human body. Therefore, it is essential to develop a methanol gas sensing technology with high sensitivity and selectivity for use in environmental monitoring and healthcare. In this work, a simple and low-cost sensor based on a Y2 O3 multishelled hollow structure (YMSH) to selectively detect methanol with an ultrasensitive limit of detection (71 ppb) is developed. The unique multishelled hollow structure with a large surface area and exposed {222} facets makes an important contribution to the ultrasensitive detection of methanol, which is further confirmed by subsequent theoretical simulations. Moreover, in situ Fourier transform infrared spectra verify that CO2 is the final product, which indicates a high catalytic activity of the YMSHs toward methanol oxidation. Interestingly, the sensor can also be applied to liquor samples that are mixtures of ethanol, methanol, and water, which provides a facile way to detect methanol in wines. This sensor represents a unique and highly sensitive means to detect methanol, which has great promise for potential application in environmental monitoring and food safety inspection.

16.
Nanotechnology ; 30(35): 355701, 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31082809

RESUMO

We report oxygen vacancies (OVs) rich hexagonal ReO3 nanostructured electrocatalysts for efficient hydrogen generation. Through a simple argon plasma exposure, OVs are introduced into the ReO3 nanoparticles (NP) and nanosheets to enhance electrocatalytic activities with decreasing overpotentails from 157 mV and 178 mV to 138 mV and 145 mV at the current density of 10 mA cm-2, respectively. As-processed OVs rich ReO3 NP exhibit a good stability during electrochemical measurements for 20 h in acidic electrolyte. The huge active surface area, abundant OVs and excellent conductivity contribute to the performance according to the experimental data. Further theoretical calculations show that the abundant OVs adsorb H with lower Gibbs free energy facilitating hydrogen evolution.

17.
Cardiovasc Ultrasound ; 16(1): 13, 2018 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-30126422

RESUMO

BACKGROUND: Atrial fibrillation (AF) can result in atrial functional mitral regurgitation (MR), but the mechanism remains controversial. Few data about the relationship between the 3-dimensional morphology of the MV and the degree of MR in AF exist. METHODS: Real-time 3-dimensional transesophageal echocardiography (3D-TEE) of the MV was acquired in 168 patients with AF (57.7% persistent AF), including 25 (14.9%) patients with moderate to severe MR (the MR+ group) and 25 patients without AF as controls. The 3-dimensional geometry of the MV apparatus was acquired using dedicated quantification software. RESULTS: Compared with the group of patients with no or mild MR (the MR- group) and the controls, the MR+ group had a larger left atrium (LA), a more dilated mitral annulus (MA), a reduced annular height to commissural width ratio (AHCWR), indicating flattening of the annular saddle shape, and greater leaflet surfaces and tethering. MR severity was correlated with the MA area (r2 = 0.43, P < 0.01) and the annulus circumference (r2 = 0.38, P < 0.01). A logistic regression analysis indicated that the MA area (OR: 1.02, 95% CI: 1.01-1.03, P < 0.01), AHCWR (OR: 0.24, 95% CI: 0.14-0.35, P = 0.04) and MV tenting volume (OR: 3.24, 95% CI: 1.16-9.08, P = 0.03) were independent predictors of MR severity in AF patients. CONCLUSIONS: The mechanisms of "atrial functional MR" are complex and include dilation of the MA, flattening of the annular saddle shape and greater leaflet tethering.


Assuntos
Função do Átrio Esquerdo/fisiologia , Ecocardiografia Tridimensional/métodos , Ecocardiografia Transesofagiana/métodos , Átrios do Coração/diagnóstico por imagem , Insuficiência da Valva Mitral/diagnóstico , Valva Mitral/diagnóstico por imagem , Idoso , Feminino , Átrios do Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Valva Mitral/fisiopatologia , Insuficiência da Valva Mitral/fisiopatologia , Reprodutibilidade dos Testes , Estudos Retrospectivos , Índice de Gravidade de Doença
18.
Echocardiography ; 34(2): 176-183, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28240425

RESUMO

BACKGROUND: The aim of this study was to investigate left atrial (LA) function and synchrony in paroxysmal atrial fibrillation (PAF) patients using two-dimensional speckle tracking echocardiography (STE). METHODS: Forty-five PAF patients and 30 healthy controls were enrolled. LA peak ventricular systolic longitudinal strain (LAS-S ) and strain rate (LASR-S ) and left atrial longitudinal strain (LAS-A ) and strain rate (LASR-A ) during late diastole were determined using STE, and the standard deviation of the time to peak (TPSD) of the regional strains was calculated to quantify LA dyssynchrony. TPSD during ventricular systole and late diastole were named SDs and SDa, respectively. RESULTS: Left atrial peak longitudinal strain during ventricular systole (LAS-S ) (29.34±8.57 vs 36.73±6.13), LASR-S (1.27±0.311 vs 1.57±0.25), LAS-A (13.11±4.91 vs 17.86±3.57), and LASR-A (-1.51±0.58 vs -1.90±0.30) were reduced in the PAF group compared with the controls (P<.05 for all). SDs (8.11±3.00% vs 4.67±1.48%) and SDa (5.57±2.26% vs 3.11±1.13%) were greater in PAF patients than in the controls (P<.05 for both). Furthermore, PAF patients with normal LA sizes exhibited lower LAS-S (P<.05), LASR-S (P<.05), LAS-A (P<.05), and LASR-A (P<.05) values and increased SDs (P<.05) and SDa (P<.05) values compared with the controls. Multivariate regression confirmed that SDs and SDa were powerful parameters for differentiating PAF patients from controls (SDs: sensitivity, 83%; specificity, 72%; SDa: sensitivity, 81%; specificity, 76%). CONCLUSIONS: Left atrial (LA) dysfunction and dyssynchrony in PAF patients can be detected with STE even in the absence of LA enlargement. STE-derived SDs and SDa were powerful parameters for identifying PAF patients.


Assuntos
Fibrilação Atrial/fisiopatologia , Função do Átrio Esquerdo/fisiologia , Ecocardiografia/métodos , Feminino , Átrios do Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
19.
Small ; 12(42): 5818-5825, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27553257

RESUMO

A controllable and scalable strategy is developed to fabricate multiplexed plasmonic nanoparticle structures by mechanical scratching with AFM lithography, which exhibit multiplex plasmonic properties and surface-enhanced Raman scattering responses. It offers an intuitive way to explore the plasmonic effects on the performance of an organic light-emitting diode device integrating with multiplexed plasmonic nanostructures.

20.
Small ; 12(29): 3976-84, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27335137

RESUMO

The atomic thickness and flatness allow properties of 2D semiconductors to be modulated with influence from the substrate. Reversible modulation of these properties requires an "active," reconfigurable substrate, i.e., a substrate with switchable functionalities that interacts strongly with the 2D overlayer. In this work, the photoluminescence (PL) of monolayer molybdenum disulfide (MoS2 ) is modulated by interfacing it with a phase transition material, vanadium dioxide (VO2 ). The MoS2 PL intensity is enhanced by a factor of up to three when the underlying VO2 undergoes the thermally driven phase transition from the insulating to metallic phase. A nonvolatile, reversible way to rewrite the PL pattern is also demonstrated. The enhancement effect is attributed to constructive optical interference when the VO2 turns metallic. This modulation method requires no chemical or mechanical processes, potentially finding applications in new switches and sensors.

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