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1.
Anal Chim Acta ; 1188: 339181, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34794568

RESUMO

In this work, MnO2 nanoflower (NF), as novel and more effective co-reaction accelerator, was applied to construct a new ternary electrochemiluminescence (ECL) system of Ru complex/tripropylamine (TPrA)/MnO2 NF. Compared with the classic Ru complex/TPrA binary ECL system, the reaction efficiency of co-reactant TPrA in the new ternary ECL system was obviously enhanced, leading to the significantly improved ECL signal by accelerating the dissociation of co-reactants into more active radicals. Then, an ECL biosensor was fabricated based on the proposed ternary ECL system, realizing the sensitive determination of glutathione (GSH). In order to realize the efficient nucleic acid amplification, a certain amount of GSH was firstly converted to a large number of intermediate DNA in assistance of Hg2+, which acted as walker could walk along with the DNA triplex immobilized on the electrode and cut off the DNA strand (S2) labeled with ferrocene (Fc). Owing to the fact that Fc possessed obvious quenching effect to the ECL of Ru complex labeled on the other side of S2, the ECL signal recovered significantly. Thus, the proposed ECL biosensor achieved the sensitive determination of GSH, and the detection limit was 50 nM.


Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , Glutationa , Medições Luminescentes , Compostos de Manganês , Óxidos , Propilaminas
2.
Nat Commun ; 12(1): 6872, 2021 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-34824225

RESUMO

Re-engineering biosynthetic assembly lines, including nonribosomal peptide synthetases (NRPS) and related megasynthase enzymes, is a powerful route to new antibiotics and other bioactive natural products that are too complex for chemical synthesis. However, engineering megasynthases is very challenging using current methods. Here, we describe how CRISPR-Cas9 gene editing can be exploited to rapidly engineer one of the most complex megasynthase assembly lines in nature, the 2.0 MDa NRPS enzymes that deliver the lipopeptide antibiotic enduracidin. Gene editing was used to exchange subdomains within the NRPS, altering substrate selectivity, leading to ten new lipopeptide variants in good yields. In contrast, attempts to engineer the same NRPS using a conventional homologous recombination-mediated gene knockout and complementation approach resulted in only traces of new enduracidin variants. In addition to exchanging subdomains within the enduracidin NRPS, subdomains from a range of NRPS enzymes of diverse bacterial origins were also successfully utilized.

3.
Anal Chem ; 93(46): 15493-15500, 2021 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-34752060

RESUMO

Depending on the reaction between walkers and tracks, DNA walker is able to output signals continuously, which has attracted great attention from the bioanalytical community. Therefore, how to improve its reaction kinetics for efficient signal readout is of great significance. Herein, a quadrilateral DNAzyme walker was fabricated by colocalizing one walker and three DNA tracks in the quadrilateral nucleic acid frame to form a reaction unit (abbreviated as qDNA walker). Impressively, in contrast to the common free DNAzyme walker, the reaction kinetics of the qDNA walker was 2.3 times faster, which could achieve microRNA detection within 30 min. Meanwhile, an electrochemiluminescence (ECL) emitter of anthracene-cucurbituril supramolecular nanocrystals (Ant-CB SNCs) was obtained based on the self-assembly of cucurbituril (CB, host molecule) and anthracene (Ant, guest molecule). Benefiting from the host-guest recognition effect, the prepared Ant-CB SNCs exhibited enhanced ECL efficiency due to the supramolecular interaction between CB and Ant, which could inhibit vibration and rotation of the Ant molecules. We defined this new enhanced ECL phenomenon as "host-guest recognition-enhanced ECL." As a proof of concept, an ECL biosensor for microRNA-21 (miRNA-21) was constructed by combining the high-efficiency DNAzyme walker and the advanced ECL emitter of Ant-CB SNCs, which showed a linear range from 50 aM to 50 pM with a low limit of detection (11 aM), highlighting the great potential in clinical diagnosis.


Assuntos
Técnicas Biossensoriais , DNA Catalítico , MicroRNAs , DNA , Técnicas Eletroquímicas , Cinética , Limite de Detecção , Medições Luminescentes
4.
Nanotechnology ; 33(8)2021 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-34731847

RESUMO

2D van der Waals materials are crystals composed of atomic layers, which have atomic thickness scale layers and rich distinct properties, including ultrafast optical response, surface effects, light-mater interaction, small size effects, quantum effects and macro quantum tunnel effects. With the exploration of saturable absorption characteristic of 2D van der Waals materials, a series of potential applications of 2D van der Waals materials as high threshold, broadband and fast response saturable absorbers (SAs) in ultrafast photonics have been proposed and confirmed. Herein, the photoelectric characteristics, nonlinear characteristic measurement technique of 2D van der Waals materials and the preparation technology of SAs are systematically described. Furthermore, the ultrafast pulsed fiber lasers based on classical 2D van der Waals materials including graphene, transition metal chalcogenides, topological insulators and black phosphorus have been fully summarized and analyzed. On this basis, opportunities and directions in this field, as well as the research results of ultrafast pulsed fiber lasers based on the latest 2D van der Waals materials (such as PbO, FePSe3, graphdiyne, bismuthene, Ag2S and MXene etc), are reviewed and summarized.

5.
Anal Chem ; 93(41): 13928-13934, 2021 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-34609848

RESUMO

Herein, a new field-free and highly ordered spherical nucleic acid (SNA) nanostructure was self-assembled directly by ferrocene (Fc)-labeled DNA tweezers and DNA linkers based on the Watson-Crick base pairing rule, which was employed as an electrochemiluminescence (ECL) quenching switch with improved recognition efficiency due to the high local concentration of the ordered nanostructure. Moreover, with a collaborative strategy combined with the advantages of both self-accelerated approach and pore confinement-enhanced ECL effect, the mesoporous silica nanospheres (mSiO2 NSs) were prepared to be filled with rubrene (Rub) as ECL emitters and Pt nanoparticles (PtNPs) as coreaction accelerators (Rub-Pt@mSiO2 NSs), which demonstrated high ECL response in the aqueous media (dissolved O2 as coreactant). When the SNA nanostructure was immobilized on the Rub-Pt@mSiO2 NSs-modified electrode, it presented a "signal off" state owing to the quenching effect of the Fc molecules. As a proof of concept, the SNA-based ECL switch platform was applied in the detection of microRNA let-7b (let-7b). Impressively, in the presence of the target let-7b, a deconstruction of the SNA nanostructure was actuated, causing the Fc to leave the electrode surface and achieved an extremely high ECL recovery ("signal on" state). Hence, a sensitive determination for let-7b was realized with a low detection limit of 1.8 aM ranging from 10 aM to 1 nM by employing the Rub-Pt@mSiO2 NSs-based ECL platform combined with the target-triggered SNA deconstruction, which also offered an ingenious method for the further applications of biomarker analyses.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , MicroRNAs , Ácidos Nucleicos , Técnicas Eletroquímicas , Limite de Detecção , Medições Luminescentes
6.
Anal Chem ; 93(35): 12075-12080, 2021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-34427443

RESUMO

Herein, with skillfully engaging stable T-Hg2+-T bonding, a "Crab Claw"-like DNA nanomachine with concise and highly efficient assembly and enhanced recognition/conversion efficiency was engineered as a super signal amplifier, which was united with Pd@Cu@Pt multimetallic mesoporous nanomaterials (Pd@Cu@Pt MMNs) for ultrasensitive electrochemical assay of mercury ions (Hg2+). Specifically, the formed "Crab Claw"-like DNA nanomachine could simultaneously trigger four same cascade DNAzyme cleavage reactions with the help of Mg2+ DNAzyme for markedly converting target Hg2+ to enormous DNA segments labeled with ferrocene (Fc), improving the detection sensitivity. Subsequently, the prepared Pd@Cu@Pt MMNs could not only show commendable electrochemical catalysis to Fc but also act as an excellent immobilization matrix for capturing and accumulating abundant Fc around them to further strengthen the electrochemical signal. As a result, the well-designed electrochemical sensor could achieve a low limit of detection of 3.58 fM in the range from 10 fM to 100 nM for Hg2+detection. This strategy offers a simple and rapid avenue to detect heavy metal ions and shows promising application potential for environmental pollutant monitoring.


Assuntos
Técnicas Biossensoriais , DNA/química , Mercúrio , Nanotecnologia , Técnicas Eletroquímicas , Limite de Detecção , Mercúrio/análise
7.
Anal Chem ; 93(31): 10890-10897, 2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34313108

RESUMO

Organic materials with diverse structures and brilliant glowing colors have been attracting extensive attention in optical electronic devices and electrochemiluminescence (ECL) fields and are currently faced with the issue of low ECL efficiency. Herein, a series of tetraphenyl alkene nanocrystals (TPA NCs) with an ordered molecular structure were synthesized to explore regularities in the crystallization-induced enhanced (CIE) ECL emission effects by altering the number and position of vinyl on the backbone of TPA molecules. Among those TPA NCs, tetraphenyl-1,3-butadiene (TPB) NCs exhibit the brightest ECL emission via a coreactant pathway, with the relative ECL efficiency of up to 31.53% versus the standard [Ru(bpy)3]2+/TEA system, which is thousands of times higher than that of free TPB molecules. The high ECL efficiency of TPB NCs originates from the effective electron transfer of unique J-aggregates on the a axis of the nanocrystals to notably promote radiative transition and the restriction on the free rotation of TPB molecules to further suppress the nonradiative transition, which has exhibited great potential in ultrasensitive biosensing, efficient light-emitting devices, and clear ECL imaging fields. As a proof of concept, since dopamine (DA) can form benzoquinone species by electrochemical oxidation to realize intermediate radical quenching and excited-state quenching on the TPB NCs/TEA system, the TPB NCs with the CIE ECL effect are used to construct an ultrasensitive ECL-sensing platform for the determination of DA with a lower detection limit of 3.1 nM.


Assuntos
Técnicas Biossensoriais , Nanopartículas , Alcenos , Cristalização , Técnicas Eletroquímicas , Medições Luminescentes
8.
J Healthc Eng ; 2021: 5556172, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34194683

RESUMO

In recent years, the prevalence of sensory integration disorders in children in urban areas has increased. Most existing sensory integration treatments are located in hospital-based sensory integration units; however, medical resources are extremely limited, making it difficult to guarantee the appropriate treatment time and intervention results for many children. The concept of sensory integration therapy must be disseminated widely and correctly to meet these children's needs. Although most urban communities have a high number of children's spaces, these spaces require improvement. This study proposes the incorporation of the concept of sensory integration therapy into neighborhood open spaces for children to positively impact children's sensory development. The purpose of this study is to determine the effective facility factors of an occupational therapy room, translate them into a community facility design, clarify the categories and relative importance of each design attribute, and explore the design strategies of the children's facilities in neighborhood open spaces based on the sensory integration theory. This study investigates the importance of the sensory integration treatment level. The facilities in neighborhood open spaces for children can be considered systemic structures consisting of five partitioned units with different levels of importance among the synergistic components within each unit. These structures will enable children to experience sensory stimulation during daily outdoor play and will serve as preventive and therapeutic tools.

9.
J Pain Res ; 14: 1415-1430, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34079358

RESUMO

Temporomandibular disorders (TMD) are a group of diseases in the oral and maxillofacial region that can manifest as acute or chronic persistent pain, affecting millions of people worldwide. Although hundreds of studies have explored mechanisms and treatments underlying TMD, multiple pathogenic factors and diverse clinical manifestations make it still poorly managed. Appropriate animal models are helpful to study the pathogenesis of TMD and explore effective treatment measures. At present, due to the high cost of obtaining large animals, rodents and rabbits are often used to prepare TMD animal models. Over the past decade, various animal models have been intensively developed to understand neurobiological and molecular mechanisms of TMD, and seek effective treatments. Although these models cannot carry out all clinical features, they are valuable in revealing the mechanisms of TMD and creating curative access. Currently, there are multitudinous animal models of TMD research. They can be constructed in different means and summarized into four ways according to the various causes and symptoms, including chemical induction (intra-articular injection of ovalbumin, collagenase, formalin, vascular endothelial growth factor, intramuscular injection of complete Freund's adjuvant, etc.), mechanical stress stimulation (passive mouth opening, change of chewing load), surgical operation (partial disc resection, joint disc perforation) and psychological stress induction. Here, we summarize and discuss different approaches of animal models for determining neurophysiological and mechanical mechanisms of TMD and assess their advantages and limitations, respectively.

10.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 52(3): 489-496, 2021 May.
Artigo em Chinês | MEDLINE | ID: mdl-34018370

RESUMO

Objective: To probe for factors that can be used effectively to predict the prognostic survival of patients with endometrial cancer recurrence. Methods: The clinicopathological data of 473 patients with stage Ⅰ to Ⅲ endometrial cancer who underwent standard surgical treatment from October 2013 to May 2019 were retrospectively collected, and post-operative recurrence of the patients were followed up. Overall recurrence includes local recurrence and poor prognosis recurrence. The endpoint indicators of this study are the recurrence-free survival (RFS) and overall survival (OS) of patients with overall recurrence, local recurrence, and poor prognosis recurrence (PPR). The Kaplan-Meier survival curve was used to evaluate the OS and RFS of patients. Cox proportional-hazards model was used to identify factors affecting the prognostic survival of patients with endometrial cancer recurrence. Results: Among the 473 patients, 406 did not experience recurrence. A total of 67 patients, accounting for 14.2%, had recurrence. Among them, 27 had local recurrence, accounting for 5.7%, while 40 had poor prognosis recurrence, accounting for 8.5%. The median follow-up time of patients with recurrence was 38 months. The survival curve showed that the RFS and OS of the patients in the recurrence-free group remained unchanged, while the patients in the recurrence group, regardless of whether they had overall recurrence, local recurrence or PPR, experienced a decrease in RFS and OS( P<0.001). The overall 3-year OS rate of patients with recurrence was 44.8%, the median survival time was 29 months, and the median recurrence time was 17 months. The 3-year OS rate of patients in the recurrence-free group was 98.8%, and the median survival time was 40 months; the 3-year OS rate of patients with local recurrence was 59.3%, the median survival time was 27 months, and the median recurrence time was 15 months. The 3-year OS rate of patients with PPR was only 35.0%, the median survival time was 22 months, and the median recurrence time was 10 months. The results of multivariate Cox regression analysis showed that, for overall recurrence patients, FIGO stage Ⅲ (hazard ratio ( HR)=3.432, P=0.005), increased expression of K-i67 ( HR=1.015, P=0.025), and decreased expression of estrogen receptor (ER) ( HR=0.985, P=0.005) are independent factors for the decline in RFS, FIGO stage Ⅲ ( HR=4.918, P=0.005) and the decreased expression of progesterone receptor (PR) ( HR=0.977, P=0.003) are independent factors for the decrease in OS. For patients with local recurrence, special pathological types ( HR=2.545, P=0.049) and increased expression of Ki-67 ( HR=1.024, P=0.033) are independent factors influencing the decrease in RFS, while decreased expression of PR ( HR=0.973, P=0.009) is an independent risk factor for decreased OS. For patients with PPR, FIGO stage Ⅲ ( HR=5.977, P=0.002) and decreased ER expression ( HR=0.984, P=0.023) are independent risk factors for the decline in RFS, while FIGO stage Ⅲ ( HR=10.098, P=0.001) is an independent factor influencing the decline of OS. Conclusion: FIGO stage Ⅲ, increased Ki-67 expression, and decreased ER expression can increase patients' risk of postoperative recurrence, and FIGO stage Ⅲ and decreased expression of PR can increase the risk of death in patients with recurrence.


Assuntos
Neoplasias do Endométrio , Recidiva Local de Neoplasia , Neoplasias do Endométrio/patologia , Feminino , Humanos , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos
12.
Cancer Epidemiol Biomarkers Prev ; 30(6): 1200-1207, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33849965

RESUMO

BACKGROUND: Based on a population with very low prevalence of smoking and alcohol drinking, we examined the associations between overall obesity and fat distribution in middle age, obesity in early adulthood, and adult weight gain with the risk of liver cancer incidence. METHODS: The associations between body mass index (BMI) at study enrollment and at age 20, waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), adult weight gain, and annual average weight gain with the risk of liver cancer were estimated using Cox regression models. Multivariable-adjusted HRs and 95% confidence intervals (CIs) were calculated. RESULTS: After a mean follow-up time of 17.5 years, 241 liver cancer cases were identified from 69,296 participants. The HRs for per 5-kg/m2 increment of BMI, per 10-cm increment of WC and HC, and per 0.1-unit increment of WHtR in middle age were 1.29 (95% CI, 1.07-1.57), 1.23 (95% CI, 1.05-1.43), 1.30 (95% CI, 1.10-1.55), and 1.37 (95% CI, 1.07-1.75), respectively. The HRs for per 5-kg increment of absolute adult weight gain and per 0.5-kg/year increment of annual average weight gain were 1.15 (95% CI, 1.06-1.25) and 1.44 (95% CI, 1.08-1.92). CONCLUSIONS: Overall and abdominal obesity in middle age and weight gain through adulthood were positively associated with liver cancer risk among non-smoking and non-alcohol-drinking women. IMPACT: Based on a cohort of non-smoking and non-alcohol-drinking women, the current study confirmed the association between obesity in middle age and increased liver cancer risk and suggested weight gain through adulthood as a risk factor for liver cancer.

13.
J Eat Disord ; 9(1): 58, 2021 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-33926562

RESUMO

BACKGROUND: The Coronavirus Disease 2019 (COVID-19) is a global pandemic and posed serious challenges in many countries. A number of studies before the COVID-19 pandemic have shown that the primary caregivers of the ED patients are subjected to great burden, psychological pressure, and serious emotional problems. This study aimed to investigate the psychological distress level of the primary caregivers of ED offspring during the COVID-19 pandemic. METHODS: From March 6 to April 20, 2020, 378 questionnaires for primary caregivers of ED offspring and 1163 questionnaires for primary caregivers of healthy offspring were collected through an online crowdsourcing platform in mainland China. Valid questionnaires that met the criteria included 343 (90.74%) primary caregivers of ED offspring and 1085 (93.29%) primary caregivers of healthy offspring. Using Propensity Score Matching (PSM), 315 (83.33%) primary caregivers of ED offspring and 315 matched primary caregivers of healthy offspring were included in the statistical analysis. Depression, anxiety, perceived stress and social support were measured by Patient Health Questionnaire-9, Generalized Anxiety Disorder-7, Perceived Stress Scale-10 and Social Support Rating Scale, respectively. RESULTS: The rates of depression and anxiety of the primary caregivers of ED offspring were 20.6 and 16.5%, which were significantly higher than those of primary caregivers of healthy offspring (4.1 and 2.2%), all P < 0.001. Regression analysis found that perceived stress, social support, previous or present mental illness, family conflicts during the COVID-19 pandemic had a significant impact on the severity of depression (P < 0.001, P = 0.002, P = 0.041, P = 0.014); Perceived stress, social support, family conflicts during the COVID-19 pandemic and years of education had a significant impact on the severity of anxiety (P < 0.001, P = 0.002, P = 0.002, P = 0.003). CONCLUSIONS: During the COVID-19 pandemic, primary caregivers of ED offspring experienced more psychological distress than that of primary caregivers of healthy offspring. ED caregivers with high perceived stress may have higher levels of depression and anxiety. ED caregivers with high social support, no mental illness and no family conflicts may have lower levels of depression. ED caregivers with high social support, no family conflicts, and high years of education may have lower levels of anxiety.

14.
Biosens Bioelectron ; 182: 113178, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33773379

RESUMO

DNA-based amplifiers with high programmability and accurate molecular recognition ability have become a versatile platform for target amplification. However, the random diffusion of capture probes (CPs) in most DNA amplifiers limits the target recognition efficiency, affecting the limit of detection. Herein, a high-efficient DNA amplifier was developed by localizing the CPs consisted of the unique palindromic tails and target recognition sequences on Au nanoparticle modified magnetic beads (Au@MBs). In the presence of target K-ras gene, the CPs with high local concentration and orientation could capture the target efficiently to expose their palindromic tails, which could act as primers to trigger the polymerization for target recycling. More importantly, the polymerization products could involve in the next recycle and produce abundant mimic targets (MTs) continuously, thereby achieving the detection of trace K-ras gene. Meanwhile, a novel electrochemiluminescence (ECL) indicator of a thin-layer of perylene (Pe) molecules decorated Ag microflowers (Pe@Ag MFs) was obtained based on the reaction between the perylene cation radical (Pe•+) and Ag atoms. The obtained Pe@Ag MFs exhibited desirable ECL performance because (i) a thin-layer of Pe molecules could reduce the inner filter effect and inactive emitters, (ii) the Ag MFs as coreaction accelerator could react with S2O82- to produce more SO4•- and shorten the distance between Pe•- and SO4•- to significantly enhance the ECL intensity of Pe with less energy loss. This work paves the way for the development of efficient amplification strategy and offers a paradigm for the preparation of high-efficiency ECL indicators.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Perileno , DNA , Técnicas Eletroquímicas , Ouro , Limite de Detecção , Medições Luminescentes , Prata
15.
Ann Transl Med ; 9(4): 326, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33708953

RESUMO

Background: Given the high prevalence of type 2 diabetes mellitus (T2DM) in the Chinese population, it is necessary to estimate the T2DM incident attributable to obesity and physical inactivity. Methods: We analyzed the data from the Shanghai Men's and Women's Health Studies, including 56,691 men and 70,849 women aged 40-74. The hazard ratios (HRs) and the population attributable risks (PARs) were calculated by Cox regression model and model-based estimation. Results: A total of 3,315 male and 5,925 female cases were identified during 519,157 and 981,504 person-years, up to 31 December 2017. Excess weight, abdominal obesity were associated with the increased risks of T2DM both in women and men, while physical inactivity was only associated with an increased risk in men. A large proportion of T2DM incident cases can be attributed to excess body weight (women: 48.6%; men: 41.5%) and abdominal obesity (women: 50.4%; men: 30.3%). Physical activity was negatively associated with the risk of T2DM (Ptrend<0.01). The PARs adjusted for confounders were 3.6% for physical inactivity in men and 1.7% in women. Conclusions: Excess weight and abdominal obesity accounted for a large proportion of T2DM incident cases in men and women; a small part of T2DM cases were attributed to physical inactivity in men. Weight control is of great significance in curbing the epidemic of diabetes.

16.
Anal Chem ; 93(12): 5301-5308, 2021 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-33739818

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) are regarded as promising electrochemiluminescent (ECL) emitters owing to their high quantum efficiency and inexpensive production. Despite the fact that the ECL properties of the pure PAH microcrystal (such as rubrene microcrystals, Rub MCs) have gained extensive attention, it is a challenge in controlling the morphology and size to reduce the inner filter effect. Herein, an advanced ECL emitter of palladium nanoparticle-functionalized hollow PAH-metal nanocubes was prepared by an in situ redox deposition method (the resultant nanocomposites were abbreviated as Pd-Rub-Ag@Au nanocubes). Specifically, the rubrene-decorated Ag@Au nanocubes (Rub-Ag@Au nanocubes) were prepared using the Ag@Au nanocubes as a template and a rubrene cation radical (Rub•+) as a reductant, and then Pd nanoparticles (Pd NPs) were in situ reduced on the surface of Rub-Ag@Au nanocubes. Impressively, compared with the Rub MCs, Pd-Rub-Ag@Au nanocubes showed uniform size and significantly enhanced ECL efficiency and intensity in the aqueous media. As a proof-of-concept, the Pd-Rub-Ag@Au nanocube-based ECL biosensing platform combined with a multisite-anchored DNA nanomachine was constructed for ochratoxin A (OTA, a type of mycotoxin) detection. The DNA nanomachine covered with high-density recognizing sequences could operate toehold-mediated strand displacement amplification on the sensing platform and promote the movement efficiency and velocity greatly. Due to the advanced performance of Pd-Rub-Ag@Au nanocubes and high recognition efficiency of the DNA nanomachine, the proposed biosensor for OTA detection can achieve a detection limit of 4.7 fg/mL ranging from 0.01 to 100 pg/mL, which offers an ingenious method for the further application of PAHs.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Micotoxinas , DNA , Técnicas Eletroquímicas , Ouro , Limite de Detecção , Medições Luminescentes
17.
Int J Cancer ; 148(12): 2982-2996, 2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-33559177

RESUMO

To date, limited studies have focused on the association between dietary fat and liver cancer risk, especially in China. Our study aims to evaluate the association between dietary fat intake and liver cancer incidence risk in men. Dietary fat intake was obtained through a validated food frequency questionnaire in a Chinese prospective cohort. The Cox regression model was utilized to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). After exclusion, 59 998 recruitments were finally analyzed with a total follow-up time of 714 339 person-years, 431 incident liver cancer cases were newly identified among them. The adjusted HRs (95% CIs) for the highest vs lowest quartile of total fat, saturated fat, monounsaturated fat (MUFA), and polyunsaturated fat (PUFA) were 1.33 (1.01-1.75), 1.50 (1.13-1.97), 1.26 (0.96-1.65), and 1.41 (1.07-1.86), and the corresponding P-trend values were .008, .005, .034, and .005, respectively. In the secondary analysis among participants tested for hepatitis B virus, we found that higher intakes of saturated fat and PUFA were also associated with increased liver cancer risks. Besides, high risks of per standard deviation alterations of the total fat, saturated fat and MUFA were detected in liver cancer, and these results were similar to those concluded from the full-cohort analysis. In conclusion, dietary intakes of total fat, saturated fat, PUFA, and probably MUFA might increase liver cancer risks. Our study provides suggestive advice to public administration on dietary suggestions, and related measures taken from managing dietary fat intake might reduce liver cancer incidence.


Assuntos
Gorduras na Dieta/efeitos adversos , Gorduras na Dieta/análise , Hepatite B/epidemiologia , Neoplasias Hepáticas/epidemiologia , Adulto , Idoso , China/epidemiologia , Hepatite B/complicações , Humanos , Incidência , Neoplasias Hepáticas/etiologia , Masculino , Pessoa de Meia-Idade , Inquéritos Nutricionais , Estudos Prospectivos
18.
Anal Chem ; 93(8): 4051-4058, 2021 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-33587601

RESUMO

Here, we described a novel swing arm location-controllable DNA walker based on the DNA tetrahedral nanostructures (DTNs) for nucleic acid detection using the polycyclic aromatic hydrocarbon (PAH) microcrystals (TAPE-Pe MCs) consisting of the nonplanar molecular tetrakis(4-aminophenyl)ethene (TAPE) and planar molecular perylene (Pe) as electrochemiluminescence (ECL) luminophores. Specifically, the swing arm strands and track strands were fixed simultaneously on the DTNs to obtain the location-controllable DNA walker, which possessed an improved reaction efficiency compared to that of a fixed swing arm-based DNA walker due to the quantitative and orderly swing arm on the DTNs. On the other hand, the Pe microcrystals doped by TAPE molecules could decrease the π-π stacking of Pe molecules for the ECL efficiency enhancement, achieving a blue-shifted and intense ECL emission. Therefore, we defined this enhanced and blue-shifted ECL phenomenon as "inhibition of conjugation-driven ECL (IC-ECL)". To prove these principles, a location-controllable DNA walker-based ECL biosensor was developed with microRNA let-7a as target molecules. The ECL biosensor achieved a low detection limit of 4.92 fM within a wide linear range from 10 fM to 100 nM. This approach offers a new insight for ECL efficiency increase and location-controllable strategies with improved reaction efficiency, demonstrating potential in diagnostic analysis.


Assuntos
Técnicas Biossensoriais , MicroRNAs , Braço , DNA , Técnicas Eletroquímicas , Limite de Detecção , Medições Luminescentes
19.
Adv Nutr ; 12(2): 402-412, 2021 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-33002099

RESUMO

Here we provide a comprehensive meta-analysis to summarize and appraise the quality of the current evidence on the associations of tea drinking in relation to cancer risk. PubMed, Embase, and the Cochrane Database of Systematic Reviews were searched up to June 2020. We reanalyzed the individual prospective studies focused on associations between tea drinking and cancer risk in humans. We conducted a meta-analysis of prospective studies and provided the highest- versus lowest-category analyses, dose-response analyses, and test of nonlinearity of each association by modeling restricted cubic spline regression for each type of tea. We graded the evidence based on the summary effect size, its 95% confidence interval, 95% prediction interval, the extent of heterogeneity, evidence of small-study effects, and excess significance bias. We identified 113 individual studies investigating the associations between tea drinking and 26 cancer sites including 153,598 cancer cases. We assessed 12 associations for the intake of black tea with cancer risk and 26 associations each for the intake of green tea and total tea with cancer risk. Except for an association between lymphoid neoplasms with green tea, we did not find consistent associations for the highest versus lowest categories and dose-response analyses for any cancer. When grading current evidence for each association (number of studies ≥2), weak evidence was detected for lymphoid neoplasm (green tea), glioma (total tea, per 1 cup), bladder cancer (total tea, per 1 cup), and gastric and esophageal cancer (tea, per 1 cup). This review of prospective studies provides little evidence to support the hypothesis that tea drinking is associated with cancer risk. More well-designed studies are still needed to identify associations between tea intake and rare cancers.


Assuntos
Neoplasias Esofágicas , Neoplasias Gástricas , Humanos , Estudos Prospectivos , Fatores de Risco , Revisões Sistemáticas como Assunto , Chá
20.
Anal Chem ; 93(2): 1120-1125, 2021 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-33295754

RESUMO

Metal nanoclusters (NCs) have attracted extensive interest in electrochemiluminescence (ECL) field, but it is still a significant challenge to prepare high ECL efficiency NCs, which tremendously precludes their application in sensing and imaging. Herein, we report poly(3,4-ethylenedioxythiophene) (PEDOT) as a functional ligand for NCs with a "kill three birds with one stone" role, acting as a stabilizer like existing templates, excitingly, excellent electrical conductivity to accelerate the injection of interfacial electrons, and outstanding electrocatalytic activity toward coreactants (S2O82-), which breaks the convention that traditional ligands act as a double-edged sword in ECL field. As an illustration, PEDOT-hosted Ag NCs were prepared with an unprecedented ECL intensity with S2O82- as a cathodic coreactant, which indicates that this novel ligand strategy will bring exciting opportunities, not only in opening up new horizons for rational development of high ECL efficiency metal NCs but also in advancing their potential applications in light-emitting devices and clinical biosensing. As a proof of concept, the PEDOT-hosted Ag NCs were applied as neoteric ECL emitters to achieve sensitive detection of dopamine (DA), which showcased a wide linear response from 1 nM to 10 mM and a low detection limit of 0.17 nM.


Assuntos
Técnicas Biossensoriais , Compostos Bicíclicos Heterocíclicos com Pontes/química , Dopamina/análise , Técnicas Eletroquímicas , Medições Luminescentes , Polímeros/química , Compostos de Sódio/química , Sulfatos/química , Eletrodos , Nanopartículas Metálicas/química , Tamanho da Partícula , Prata/química , Propriedades de Superfície
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