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1.
J Am Chem Soc ; 146(23): 16039-16051, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38832517

RESUMO

Efficient methane photooxidation to formic acid (HCOOH) has emerged as a sustainable approach to simultaneously generate value-added chemicals and harness renewable energy. However, the persistent challenge lies in achieving a high yield and selectivity for HCOOH formation, primarily due to the complexities associated with modulating intermediate conversion and desorption after methane activation. In this study, we employ first-principles calculations as a comprehensive guiding tool and discover that by precisely controlling the O2 activation process on noble metal cocatalysts and the adsorption strength of carbon-containing intermediates on metal oxide supports, one can finely tune the selectivity of methane photooxidation products. Specifically, a bifunctional catalyst comprising Pd nanoparticles and monoclinic WO3 (Pd/WO3) would possess optimal O2 activation kinetics and an intermediate oxidation/desorption barrier, thereby promoting HCOOH formation. As evidenced by experiments, the Pd/WO3 catalyst achieves an exceptional HCOOH yield of 4.67 mmol gcat-1 h-1 with a high selectivity of 62% under full-spectrum light irradiation at room temperature using molecular O2. Notably, these results significantly outperform the state-of-the-art photocatalytic systems operated under identical condition.

2.
Chemphyschem ; 25(13): e202400138, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38507137

RESUMO

Circularly polarized luminescence (CPL) materials hold significant value in various fields, including information storage, secure communication, three-dimensional displays, biological detection, and optoelectronic devices. Using the Langmuir-Schaeffer (LS) assembly technique, we successfully construct a series of large-area flexible optical ultrathin films. Impressively, the inorganic assembled ultrathin films exhibit excellent CPL optical activity covering the visible to near-infrared (NIR) region, with the luminescence asymmetry factor glum ranging from 0.59 to 0.72. Moreover, such ultrathin films also display outstanding mechanical flexibility, the optical activity of which even after 240 bending cycles shows almost no difference compared to the unbent samples. Owing to the ultra-broadband optical activity and ultra-stable optical activity of such full-inorganic assembled materials on flexible substrates, coupled with their excellent processability and outstanding mechanical flexibility, we anticipate they will find use in many fields such as communication technology and flexible optoelectronics.

3.
Angew Chem Int Ed Engl ; 62(52): e202315478, 2023 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-37946688

RESUMO

Photoelectrochemistry is becoming an innovative approach to organic synthesis. Generally, the current photoelectrocatalytic organic transformations suffer from limited reaction type, low conversion efficiency and poor stability. Herein, we develop efficient and stable photoelectrode materials using metal oxide protective layer, with a focus on achieving regioselective activation of amine compounds. Notably, our photoelectrochemistry process is implemented under mild reaction conditions and does not involve any directing groups, transition metals or oxidants. The results demonstrate that beyond photocatalysis and electrocatalysis, photoelectrocatalysis exhibits high efficiency, remarkable repeatability and good functional group tolerance, highlighting its great potential for applications.

4.
Stat Med ; 40(2): 441-450, 2021 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-33145780

RESUMO

For massive survival data, we propose a subsampling algorithm to efficiently approximate the estimates of regression parameters in the additive hazards model. We establish consistency and asymptotic normality of the subsample-based estimator given the full data. The optimal subsampling probabilities are obtained via minimizing asymptotic variance of the resulting estimator. The subsample-based procedure can largely reduce the computational cost compared with the full data method. In numerical simulations, our method has low bias and satisfactory coverage probabilities. We provide an illustrative example on the survival analysis of patients with lymphoma cancer from the Surveillance, Epidemiology, and End Results Program.


Assuntos
Algoritmos , Viés , Humanos , Probabilidade , Modelos de Riscos Proporcionais , Análise de Sobrevida
5.
BMC Microbiol ; 18(1): 203, 2018 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-30509171

RESUMO

BACKGROUND: Farnesol has potential antifungal activity against Candida albicans biofilms, but the molecular mechanism of this activity is still unclear. Farnesol inhibits hyphal growth by regulating the cyclic AMP (cAMP) signalling pathway in C. albicans, and CYR1 and PDE2 regulate a pair of enzymes that are directly responsible for cAMP synthesis and degradation. Here, we hypothesize that farnesol enhances the antifungal susceptibility of C. albicans biofilms by regulating CYR1 and PDE2. RESULTS: The resistance of the CYR1- and PDE2-overexpressing strains to caspofungin, itraconazole and terbinafine was increased in planktonic cells, and that to amphotericin B was increased in biofilms. Meanwhile, the biofilms of the CYR1- and PDE2-overexpressing strains were thicker (all p < 0.05) and consisted of more hyphae than that of the wild strain. The intracellular cAMP levels were higher in the biofilms of the CYR1-overexpressing strain than that in the biofilms of the wild strain (all p < 0.01), while no changes were found in the PDE2-overexpressing strain. Exogenous farnesol decreased the resistance of the CYR1- and PDE2-overexpressing strains to these four antifungals, repressed the hyphal and biofilm formation of the strains, and decreased the intracellular cAMP level in the biofilms (all p < 0.05) compared to the untreated controls. In addition, farnesol decreased the expression of the gene CYR1 and the protein CYR1 in biofilms of the CYR1-overexpressing strain (all p < 0.05) but increased the expression of the gene PDE2 and the protein PDE2 in biofilms of the PDE2-overexpressing strain (all p < 0.01). CONCLUSIONS: The results indicate that CYR1 and PDE2 regulate the resistance of C. albicans biofilms to antifungals. Farnesol suppresses the resistance of C. albicans biofilms to antifungals by regulating the expression of the gene CYR1 and PDE2, while PDE2 regulation was subordinate to CYR1 regulation.


Assuntos
Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Nucleotídeo Cíclico Fosfodiesterase do Tipo 2/metabolismo , Farmacorresistência Fúngica , Farneseno Álcool/farmacologia , Proteínas Fúngicas/metabolismo , Candida albicans/genética , Candida albicans/fisiologia , Caspofungina/farmacologia , Nucleotídeo Cíclico Fosfodiesterase do Tipo 2/genética , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Hifas/efeitos dos fármacos , Hifas/genética , Hifas/metabolismo , Terbinafina/farmacologia
6.
BMC Oral Health ; 18(1): 152, 2018 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-30157822

RESUMO

BACKGROUND: The root canal glide path has been recommended as the foundation for a safer root canal preparation. The aim of this study was to compare glide paths created with K-files, PathFiles, and the ProGlider file, and their effects on subsequent WaveOne preparation regarding canal transportation, canal volume increase, apical extruded debris, and working time in curved canals. METHODS: Sixty mesial canals of extracted human mandibular first molars were randomly assigned to the K-file (KF), PathFile (PF) and ProGlider file (PG) groups for glide path preparation. Then, canals were prepared using WaveOne files. Specimens were scanned (voxel size: 18 µm) three times using micro-computed tomography: pre-glide path, post-glide path, and post-root canal preparation. Canal transportations were measured at 1, 3, and 5 mm levels from the apical foramen, and canal volume increases were also accounted. Apical extruded debris during preparation was collected for measurement. Meanwhile,working time was recorded. Data were analyzed statistically using one-way analysis of variance and Tukey's post hoc tests (p < 0.05). RESULTS: After glide path preparation, the PG and PF groups showed significantly less canal transportation than the KF group at all levels (P < 0.05), while the PG group exhibited a significantly larger canal volume increase than the PF and KF groups (P < 0.05). After the subsequent canal preparation with WaveOne, the PG and PF groups showed significantly less canal transportation than the KF group at 3 and 5 mm levels, and the PG group showed significantly less canal transportation than the PF group at 5 mm level (P < 0.05). However, statistically similar canal volume increases occurred among the three groups. Additionally, the PG and PF groups produced less apical extruded debris compared to the KF group (P < 0.05). The working time of the PG group was the shortest, while that of the KF group was the longest. CONCLUSION: Compared with the PathFiles and K-files, the ProGlider file combined with the WaveOne file showed reduced canal transportation and working time.


Assuntos
Dente Molar/cirurgia , Preparo de Canal Radicular/instrumentação , Desenho de Equipamento , Humanos , Técnicas In Vitro , Mandíbula , Dente Molar/diagnóstico por imagem , Fatores de Tempo , Microtomografia por Raio-X
7.
Anim Biotechnol ; 27(4): 231-7, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27565866

RESUMO

Secreted frizzled related protein 5 (SFRP5), an anti-inflammatory adipokine, is relevant to the adipocyte differentiation. In order to clarify its role in regulating intramuscular fat (IMF) deposition in Tibetan chicken, the full-length sequence of the Tibetan chicken SFRP5 gene was cloned. The relative expression of SFRP5 gene was detected using quantitative RT-PCR in various tissues of 154 days old Tibetan chicken, as well as in breast muscle, thigh muscle, and adipose tissue at different growth stages. The results showed that SFRP5 gene was expressed in all examined tissues but highly enriched in adipose tissue. Temporal expression profile showed that the expression of SFRP5 was gradually decreased in breast muscle, but was fluctuated in thigh muscle and adipose tissue with the growth of Tibetan chicken. Furthermore, correlation analysis demonstrated that the expression of SFRP5 in breast muscle, thigh muscle and adipose tissue was correlated with IMF content at different levels. The results indicated that Tibetan chicken SFRP5 is involved in IMF deposition.


Assuntos
Adipocinas , Tecido Adiposo/metabolismo , Proteínas Aviárias , Galinhas , Músculo Esquelético/metabolismo , Adipocinas/química , Adipocinas/genética , Adipocinas/metabolismo , Animais , Proteínas Aviárias/química , Proteínas Aviárias/genética , Proteínas Aviárias/metabolismo , Diferenciação Celular/genética , Galinhas/genética , Galinhas/metabolismo , Galinhas/fisiologia , Clonagem Molecular , Feminino , Masculino , Filogenia , Via de Sinalização Wnt/genética
8.
Virus Res ; 332: 199130, 2023 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-37178792

RESUMO

Nipah virus (NiV) is a zoonotic pathogen with airborne transmission and high case fatality rates in humans. There is currently no treatment or vaccine against NiV infection approved for humans or animals, therefore early diagnosis is the key to control any potential outbreaks. In this study, we developed an optimized one-pot assay using recombinase polymerase amplification (RPA) coupled to CRISPR/Cas13a for the molecular detection of NiV. The one-pot RPA-CRISPR/Cas13a assay for NiV detection was specific and did not cross-react against other selected (re)-emerging pathogens. The sensitivity of the one-pot RPA-CRISPR/Cas13a assay for NiV detection can detect as little as 103 cp/µL of total synthetic NiV cDNA. The assay was then validated with simulated clinical samples. The results for the one-pot RPA-CRISPR/Cas13a assay could be visualized with either fluorescence or lateral flow strips for convenient clinical or field diagnostics, providing a useful supplement to the gold-standard qRT-PCR assay for detecting NiV detections.


Assuntos
Vírus Nipah , Recombinases , Humanos , Animais , Recombinases/metabolismo , Sensibilidade e Especificidade , Vírus Nipah/genética , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Reação em Cadeia da Polimerase/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Nucleotidiltransferases/genética
9.
Viruses ; 15(1)2022 12 28.
Artigo em Inglês | MEDLINE | ID: mdl-36680124

RESUMO

A recent outbreak of monkeypox virus (mpox) has prompted researchers to explore diagnostics as a means of impeding transmission and further spread. Rapid, sensitive, and specific methods are crucial for accurately diagnosing mpox infections. Here, we developed a loop-mediated isothermal amplification (LAMP) assay for the specific detection of mpox. The primer sets were designed to target regions in and around the N4R gene, and results showed a detection limit of 2 × 100 DNA copies, which is comparable to the gold-standard qPCR method currently used to detect mpox. Particularly, the assay provides results visible to the naked eye within 30 min. This test specifically detects mpox DNA with no cross-reactivity to related DNA viruses including Varicella Zoster Virus (VZV), Hepatitis B virus (HBV), Vaccinia virus (VACV), Herpes simplex virus-1 (HSV-1), Herpes simplex virus-2 (HSV-2), Human papillomavirus-16 (HPV-16) and Human papillomavirus-18 (HPV-18). Furthermore, the LAMP assay has been evaluated using clinical samples from laboratory-confirmed mpox patients and found to be consistent with the qPCR results. Our results show that this single-tube LAMP method can contribute to diagnosis of suspected mpox infections in the field and clinic, especially in regions with limited laboratory resources.


Assuntos
Monkeypox virus , Mpox , Humanos , Monkeypox virus/genética , Mpox/diagnóstico , DNA Viral/genética , DNA Viral/análise , Técnicas de Amplificação de Ácido Nucleico/métodos , Herpesvirus Humano 3/genética , Herpesvirus Humano 2/genética , Sensibilidade e Especificidade
10.
Virol Sin ; 36(4): 746-754, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33635517

RESUMO

Human herpesviruses are double-stranded DNA viruses that are classified into nine species. More than 90% of adults are ever infected with one or more herpesviruses. The symptoms of infection with different herpesviruses are diverse ranging from mild or asymptomatic infections to deadly diseases such as aggressive lymphomas and sarcomas. Timely and accurate detection of herpesvirus infection is critical for clinical management and treatment. In this study, we established a single-tube nonuple qPCR assay for detection of all nine herpesviruses using a 2-D multiplex qPCR method with a house-keeping gene as the internal control. The novel assay can detect and distinguish different herpesviruses with 30 to 300 copies per 25 µL single-tube reaction, and does not cross-react with 20 other human viruses, including DNA and RNA viruses. The robustness of the novel assay was evaluated using 170 clinical samples. The novel assay showed a high consistency (100%) with the single qPCR assay for HHVs detection. The features of simple, rapid, high sensitivity, specificity, and low cost make this assay a high potential to be widely used in clinical diagnosis and patient treatment.


Assuntos
Infecções por Herpesviridae , Herpesviridae , Adulto , Herpesviridae/genética , Infecções por Herpesviridae/diagnóstico , Humanos , Reação em Cadeia da Polimerase Multiplex , Reação em Cadeia da Polimerase em Tempo Real , Sensibilidade e Especificidade
12.
Cell Biochem Funct ; 28(7): 585-90, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20941748

RESUMO

5,10-Methylenetetrahydrofolate reductase (MTHFR) catalyzes the metabolism of folate and nucleotides, which are essential for DNA synthesis and methylation. It is highly polymorphic, and its variant genotypes result in lower enzymatic activity and higher plasma homocysteine. Previous studies have provided evidence that a high prevalence of MTHFR gene polymorphisms is frequently detected in patients with autoimmune disease, suggesting a novel genetic association with autoimmune disorders. However, the genetic association between MTHFR and Graves' disease (GD), one of the most common autoimmune diseases, has not been studied. Here, we designed a clinic-based case-control study including 199 GD cases and 235 healthy controls to examine the associations between three common MTHFR polymorphisms (i.e., C677T, A1298C, and G1793A) and GD. Surprisingly, logistic regression analysis shows MTHFR 677CT + TT genotypes are associated with an approximately 42% reduction in the risk of GD in women (adjusted OR = 0.58, 95% CI = 0.3-0.9), compared to the CC genotype, indicating a significant protective effect of 677CT + TT genotypes. Our result provides epidemiological evidence that MTHFR mutation (C677T) protects women from GD. The protective effect, possibly obtained by influencing DNA methylation, should be confirmed in a large number of cohorts.


Assuntos
Doença de Graves/enzimologia , Doença de Graves/genética , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Polimorfismo de Nucleotídeo Único , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Criança , China , Feminino , Estudos de Associação Genética , Haplótipos , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Adulto Jovem
14.
EClinicalMedicine ; 18: 100238, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31922125

RESUMO

BACKGROUND: The emergence and spread of HIV-1 drug resistance may compromise HIV control globally. In response to HIV/AIDS epidemic, China launched national HIV/AIDS treatment program in 2003, and started to accumulate drug resistance data since 2001. In this study we aimed to assess the level, trend and distribution of HIV-1 drug resistance during a period of 17 years from 2001 to 2017, and to characterize crucial drug resistance mutations. METHODS: We systematically reviewed 4737 studies published between January 1, 2001 and March 31, 2019 in PubMed, Embase, China National Knowledge Infrastructure (CNKI), WanFang Database, Web of Science, conference abstracts from the Chinese Medical Association and the Chinese AIDS Academic Conferences, and selected 170 studies that met our study criteria. To assess the prevalence of drug resistance in whole country or a local region, we performed pooled analyses of raw data. The transformed proportions were pooled using the inverse variance fixed effects methods or the DerSimonian-Laired random effects methods. The temporal trend of transmitted drug resistance (TDR) was determined using generalized additive model implemented in the Mgcv version 1.8 package. HIV-1 genotypic resistance was analyzed using the Stanford HIVdb algorithm. FINDINGS: We assembled 218 datasets from 170 selected studies (129 in Chinese and 41 in English), covering 21,451 ART-naïve and 30,475 ART-treated individuals with HIV-1 infection. The pooled prevalence of TDR was 3.0% (95%CI: 2.8-3.2), including 0.7% (95%CI: 0.4-1.0), 1.4% (95%CI: 1.3-1.6) and 0.5% (95%CI: 0.4-0.6) for nucleoside reverse transcriptase inhibitor (NRTI), non-NRTI (NNRTI) and protease inhibitor (PI) resistance, respectively. The acquired drug resistance (ADR) prevalence was 44.7% (95%CI: 39.3-50.2), including 31.4% (95%CI: 28.2-34.6), 39.5% (95%CI: 35.6-43.5) and 1.0% (95%CI: 0.8-1.2) for NRTI, NNRTI and PI resistance, respectively. TDR and ADR prevalence had characteristic regional patterns. The worst prevalence of drug resistance occurred in Central China, and higher ADR prevalence occurred in South China than North China. TDR in whole country has risen since 2012, and this rise was driven mainly by NNRTI resistance. One NRTI-associated (M184V/I) and three NNRTI-associated (K103N/S, Y181C/I and G190A/S) mutations had high percentages in ART-naïve and ART-treated individuals, and these mutations conferred high-level resistance to 3TC, EFV and/or NVP. INTERPRETATION: These findings suggest that the current available first-line ART regimens containing 3TC and/or EFV or NVP need to be revised. In addition, scale-up of multiple viral load measurements per year and drug resistance testing prior to ART initiation are recommended. Furthermore, implementation of pre-treatment education and counseling to improve patient adherence to ART is encouraged. FUNDING: This work was supported by grants from the National Natural Science Foundation of China (81672033, U1302224, and 81271888) and Open Research Fund Program of the State Key Laboratory of Virology of China (2019IOV002).

15.
Curr HIV Res ; 17(4): 225-239, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31560290

RESUMO

AIDS is a globalized infectious disease. In 2014, UNAIDS launched a global project of "90-90-90" to end the HIV epidemic by 2030. The second and third 90 require 90% of HIV-1 infected individuals receiving antiretroviral therapy (ART) and durable virological suppression. However, wide use of ART will greatly increase the emergence and spreading of HIV drug resistance and current HIV drug resistance test (DRT) assays in China are seriously lagging behind, hindering to achieve virological suppression. Therefore, recommending an appropriate HIV DRT method is critical for HIV routine surveillance and prevention in China. In this review, we summarized the current existing HIV drug resistance genotypic testing methods around the world and discussed the advantages and disadvantages of these methods.


Assuntos
Fármacos Anti-HIV/farmacologia , Farmacorresistência Viral , Genótipo , Infecções por HIV/diagnóstico , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , HIV-1/genética , Tipagem Molecular , Alelos , Fármacos Anti-HIV/uso terapêutico , Terapia Antirretroviral de Alta Atividade , China , Monitoramento de Medicamentos , Genoma Viral , Infecções por HIV/tratamento farmacológico , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Tipagem Molecular/métodos , Mutação , RNA Viral , Análise de Sequência de DNA , Carga Viral
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