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1.
Abdom Radiol (NY) ; 2021 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-33388804

RESUMO

PURPOSE: R2* relaxometry is a quantitative method for assessment of iron overload. The purpose is to analyze the cross-sectional relationships between R2* in organs across patients with primary and secondary iron overload. Secondary analyses were conducted to analyze R2* according to treatment regimen. METHODS: This is a retrospective, cross-sectional, institutional review board-approved study of eighty-one adult patients with known or suspected iron overload. R2* was measured by segmenting the liver, spleen, bone marrow, pancreas, renal cortex, renal medulla, and myocardium using breath-hold multi-echo gradient-recalled echo imaging at 1.5 T. Phlebotomy, transfusion, and chelation therapy were documented. Analyses included correlation, Kruskal-Wallis, and post hoc Dunn tests. p < 0.01 was considered significant. RESULTS: Correlations between liver R2* and that of the spleen, bone marrow, pancreas, and heart were respectively 0.49, 0.33, 0.27, and 0.34. R2* differed between patients with primary and secondary overload in the liver (p < 0.001), spleen (p < 0.001), bone marrow (p < 0.01), renal cortex (p < 0.001), and renal medulla (p < 0.001). Liver, spleen, and bone marrow R2* were higher in thalassemia than in hereditary hemochromatosis (all p < 0.01). Renal cortex R2* was higher in sickle cell disease than in hereditary hemochromatosis (p < 0.001) and in thalassemia (p < 0.001). Overall, there was a trend toward lower liver R2* in patients assigned to phlebotomy and higher liver R2* in patients assigned to transfusion and chelation therapy. CONCLUSION: R2* relaxometry revealed differences in degree or distribution of iron overload between organs, underlying etiologies, and treatment.

2.
Huan Jing Ke Xue ; 42(1): 323-332, 2021 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-33372484

RESUMO

The waste sludge of municipal wastewater treatment plants is an important reservoir for antibiotic resistance genes (ARG). It is necessary to explore the fate of ARG, microbial community succession, and the correlations between them. Therefore, the distribution of ARG and the microbial community structure of waste sludge from wastewater treatment plants with A2O and A2O-MBR processes during microwave pretreatment and anaerobic digestion were studied in this research. The results showed that the occurrence of ARG and the microbial community structure were quite different in the waste sludge of A2O and A2O-MBR processes. The microwave pretreatment did not change the microbial community much, whereas the community structure of the digested sludge with pretreatment showed significant differences. Anaerobic digestion had a conformity effect on the distribution of ARG and MGE in the digested sludge with or without pretreatment. Among genes, ermF, qnrS, and blaNDM-1 were the most difficult to be reduced ARG and were prone to propagation during anaerobic digestion. The influence of biomass, ammonia nitrogen, and phosphorus on the distribution of ARG and MGE was higher than that of other environmental factors. The sludge characteristics also showed important impacts on the microbial community, especially on some genera with specific functions. These results could help people to better understand the spread and control of ARG during sludge anaerobic digestion.


Assuntos
Micro-Ondas , Esgotos , Anaerobiose , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Humanos , Eliminação de Resíduos Líquidos
3.
Front Public Health ; 8: 600196, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33335880

RESUMO

Background: Measles transmissions due to case importations challenge public health systems globally and herd immunities in all countries. In 2019, an imported measles case and its subsequently outbreak was found in the Zhoushan Islands. Here, the process of epidemiological investigation and virus tracing were summarized to provide references for the prevention and control of measles in the future. Materials and methods: The data on the demographic, epidemiological, and clinical manifestation of measles cases in this outbreak were collected. The 450 bp fragments of the measles virus (MeV) N gene were amplified and sequenced. The genome of the first imported case was further isolated. Then, the maximum-likelihood and time-scaled phylogenetic analysis was conducted. Results: A total of 28 measles cases were confirmed. Their onsets were between March 13 and May 18, 2019. The first patient was from the Ukraine. He was confirmed at the Fever Clinic in Zhoushan hospital on March 15, 2019 and at the same time, another patient had visited the hospital due to another illness and 10 days later, this second case had onset (March 25, 2019). The epidemic curve shows sustained community transmission. The majority of the following cases (19/26) were clustered on the Donggang street which was close to where the second case worked. The 22 measles virus strains successfully isolated from this outbreak all belonged to the D8.2a sub-cluster and clustered with the KY120864/MVs/GirSomnath.IND/42.16/[D8] which was the predominant genotype in the Ukraine during 2018-2019. The analysis of the complete D8 genotype genome pointed to the fact that this prevailing strain originated from India in 2015 and its substitution rate was estimated as 6.91 × 10-4 (5.64-7.98 × 10-4) nucleotide substitutions/site/year. Conclusion: This outbreak was caused by an imported case from the Ukraine. There was a possible nosocomial infection between the first case and the second case. Then, the second case played an important role in the spread of virus due to her occupation. The molecular phylogenetic analysis could help to track the origin of the virus. Increasing and maintaining the high level of vaccination coverage (≥95%) and an efficient response to imported cases are essential to prevent and control the recurrence and outbreak of measles virus.

4.
Acad Radiol ; 2020 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-33158701

RESUMO

In this review article, we discuss the literature pertaining to the bibliometric analysis of academic radiologists' scholarly activity in order to identify current trends, knowledge gaps, and potential future directions. Current research provides cross-sectional analyses of bibliometrics on three main themes: academic ranking, gender disparity, and research funding. The most commonly used parameters are the publication and the citation counts, the h-index and the number of years in academia. The h-index correlates positively with academic ranking and, in the case of editorial board members, with the journal's impact factor. Scholars who have secured National Institutes of Health funding tend to have higher h-indexes than those who have not. Whereas gender balance has been achieved in medical school and in several medical specialties, women remain significantly fewer than men in most areas of radiology. The underrepresentation of women is particularly noticeable at higher academic ranks and in leadership positions, suggesting that significant barriers to female radiologists' career advancement exist. Scholarly productivity of radiology residents and the impact of research on academic productivity are subjects that have received less attention in the published literature. Future studies should focus on whether bibliometric parameters can be used as reliable measurements of scholarly activity to help determine appointments, promotions and grant allocations, and to assess interventions that promote gender parity.

5.
J Clin Invest ; 2020 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-33211673

RESUMO

ABSTRACTIndividuals harboring the loss-of-function (LOF) proprotein convertase subtilising/kexin type 9 Gln152His variation (PCSK9Q152H) have low circulating low-density lipoprotein (LDL) cholesterol levels and are therefore protected against cardiovascular disease (CVD). This uncleavable form of pro-PCSK9, however, is retained in the endoplasmic reticulum (ER) of liver hepatocytes where it would be expected to contribute to ER storage disease (ERSD); a heritable condition known to cause systemic ER stress and liver injury. Here, we examined liver function in members of several French-Canadian families known to carry the PCSK9Q152H variation. We report that PCSK9Q152H carriers exhibited marked hypocholesterolemia and normal liver function despite their lifelong state of ER PCSK9 retention. Mechanistically, hepatic overexpression of PCSK9Q152H using adeno-associated viruses in male mice greatly increased the stability of key ER stress response chaperones in liver hepatocytes and unexpectedly protected against ER stress and liver injury rather than to induce them. Our findings show that ER retention of PCSK9 not only reduced CVD risk in patients but may also protect against ERSD and other ER stress-driven conditions of the liver. In summary, we have uncovered a co-chaperone function for PCSK9Q152H that explains its hepatoprotective effects and generated a translational mouse model for further mechanistic insights into this clinically relevant LOF PCSK9 variant.

6.
Can Assoc Radiol J ; : 846537120967349, 2020 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-33138621

RESUMO

The application of big data, radiomics, machine learning, and artificial intelligence (AI) algorithms in radiology requires access to large data sets containing personal health information. Because machine learning projects often require collaboration between different sites or data transfer to a third party, precautions are required to safeguard patient privacy. Safety measures are required to prevent inadvertent access to and transfer of identifiable information. The Canadian Association of Radiologists (CAR) is the national voice of radiology committed to promoting the highest standards in patient-centered imaging, lifelong learning, and research. The CAR has created an AI Ethical and Legal standing committee with the mandate to guide the medical imaging community in terms of best practices in data management, access to health care data, de-identification, and accountability practices. Part 1 of this article will inform CAR members on principles of de-identification, pseudonymization, encryption, direct and indirect identifiers, k-anonymization, risks of reidentification, implementations, data set release models, and validation of AI algorithms, with a view to developing appropriate standards to safeguard patient information effectively.

7.
Can Assoc Radiol J ; : 846537120967345, 2020 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-33140663

RESUMO

The application of big data, radiomics, machine learning, and artificial intelligence (AI) algorithms in radiology requires access to large data sets containing personal health information. Because machine learning projects often require collaboration between different sites or data transfer to a third party, precautions are required to safeguard patient privacy. Safety measures are required to prevent inadvertent access to and transfer of identifiable information. The Canadian Association of Radiologists (CAR) is the national voice of radiology committed to promoting the highest standards in patient-centered imaging, lifelong learning, and research. The CAR has created an AI Ethical and Legal standing committee with the mandate to guide the medical imaging community in terms of best practices in data management, access to health care data, de-identification, and accountability practices. Part 2 of this article will inform CAR members on the practical aspects of medical imaging de-identification, strengths and limitations of de-identification approaches, list of de-identification software and tools available, and perspectives on future directions.

8.
Can Assoc Radiol J ; : 846537120967720, 2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-33064568
9.
Eur Radiol ; 2020 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-32876833

RESUMO

OBJECTIVE: To evaluate the diagnostic performance of intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) for grading hepatic inflammation. METHODS: In this retrospective cross-sectional dual-center study, 91 patients with chronic liver disease were recruited between September 2014 and September 2018. Patients underwent 3.0-T MRI examinations within 6 weeks from a liver biopsy. IVIM parameters, perfusion fraction (f), diffusion coefficient (D), and pseudo-diffusion coefficient (D*), were estimated using a voxel-wise nonlinear regression on DWI series (10 b-values from 0 to 800 s/mm2). The reference standard was histopathological analysis of hepatic inflammation grade, steatosis grade, and fibrosis stage. Intraclass correlation coefficients (ICC), univariate and multivariate correlation analyses, and areas under receiver operating characteristic curves (AUC) were assessed. RESULTS: Parameters f, D, and D* had ICCs of 0.860, 0.839, and 0.916, respectively. Correlations of f, D, and D* with inflammation grade were ρ = - 0.70, p < 0.0001; ρ = 0.10, p = 0.35; and ρ = - 0.27, p = 0.010, respectively. When adjusting for fibrosis and steatosis, the correlation between f and inflammation (p < 0.0001) remained, and that between f and fibrosis was also significant to a lesser extent (p = 0.002). AUCs of f, D, and D* for distinguishing inflammation grades 0 vs. ≥ 1 were 0.84, 0.53, and 0.70; ≤ 1 vs. ≥ 2 were 0.88, 0.57, and 0.60; and ≤ 2 vs. 3 were 0.86, 0.54, and 0.65, respectively. CONCLUSION: Perfusion fraction f strongly correlated, D very weakly correlated, and D* weakly correlated with inflammation. Among all IVIM parameters, f accurately graded inflammation and showed promise as a biomarker of hepatic inflammation. KEY POINTS: • IVIM parameters derived from DWI series with 10 b-values are reproducible for liver tissue characterization. • This retrospective two-center study showed that perfusion fraction provided good diagnostic performance for distinguishing dichotomized grades of inflammation. • Fibrosis is a significant confounder on the association between inflammation and perfusion fraction.

10.
Biosens Bioelectron ; 168: 112556, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32890931

RESUMO

We reported a CRISPR/Cas-based dual amplified sensing strategy for rapid, sensitive and selective detection of polynucleotide kinase/phosphatase (PNKP), a DNA damage repair-related biological enzyme. In this strategy, a PNKP-triggered nicking enzyme-mediated strand displacement amplification reaction was introduced to enrich the activator DNA strands for CRISPR/Cas. Such an isothermal DNA amplification step, together with subsequent activated CRISPR/Cas-catalyzed cleavage of fluorescent-labeled short-stranded DNA probes, enable synergetic signal amplification for sensitive PNKP detection. The proposed strategy showed a wide linear detection range (more than 3 orders of magnitude ranging from 1× 10-5 to 2.5 × 10-2 U/mL T4 PNKP) and a detection limit as low as 3.3 × 10-6 U/mL. It was successfully used for the PNKP activity detection in cell extracts with high fidelity and displayed great potential for enzyme inhibitor screening and inhibitory capability evaluation. This work broadens the applications of CRISPR/Cas12a-based sensors to biological enzymes and provides a way to improve the sensitivity by introducing an isothermal signal amplification step. Such an isothermal DNA amplification-CRISPR/Cas-combined biosensor design concept might expand CRISPR/Cas-based sensing systems and promote their applications in various fields such as disease diagnosis and drug screening.

12.
PLoS One ; 15(9): e0234835, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32881864

RESUMO

In this study, the physiological values of volumes of plasma, cells, total blood and the F blood factors were identified in 24 adult tree shrews (Tupaia belangeri; 12 male and 12 female; average BW of 123.9±19.19 g). The two-compartment model method of Evans Blue dye was used to obtain the plasma volume and the venous hematocrit was measured by microhematocrit method. To establish the relationship between body weight (BW) and blood volume of tree shrews, We performed linear fitting for these two datasets. Results were analyzed according to gender and weight (<120g vs.>120g). Statistical significance was assessed using the unpaired student t test and one-way ANOVA. The average volumes per 100g body weight of plasma, red blood cell (RBC) and total blood were 5.42±0.543, 3.24±0.445, and 8.66±0.680ml respectively. The mean body hematocrit, cardiac hematocrit, jugular vein hematocrit, femoral vein hematocrit, and tail vein hematocrit was 37.43±4.096, 39.72±3.219, 43.04±4.717, 40.84±3.041, and 38.71±3.442% respectively. The F cardiac was 0.94±0.072, F jugular vein 0.88±0.118, F femoral vein 0.92±0.111, and the F tail vein 0.97±0.117. Blood volume (ml) was 85.89103×BW (kg). This is the first study to provide the parameters of plasma volume, cell volume, total blood volume and F factor and a baseline for future research on blood physiology of tree shrews.


Assuntos
Tupaiidae/sangue , Animais , Volume Sanguíneo , Peso Corporal , Tamanho Celular , Feminino , Hematócrito , Masculino , Volume Plasmático , Tupaiidae/fisiologia
13.
Ultrasonography ; 39(3): 221-228, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32475089

RESUMO

The Liver Imaging Reporting and Data System (LI-RADS) was created to standardize liver imaging in patients at high risk for hepatocellular carcinoma (HCC), and it uses a diagnostic algorithm to assign categories that reflect the relative probability of HCC, non-HCC malignancies, or benign focal liver lesions. In addition to major imaging features, ancillary features (AFs) are used by radiologists to refine the categorization of liver nodules. In the present document, we discuss and explain the application of AFs currently defined within the LI-RADS guidelines. We also explore possible additional AFs visible on contrast-enhanced ultrasonography (CEUS). Finally, we summarize the management of CEUS LI-RADS features, including the role of current and potential future AFs.

14.
Abdom Radiol (NY) ; 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32488557

RESUMO

PURPOSE: To perform an international survey on current practices in imaging-based surveillance, diagnosis, staging, and assessment of treatment response for HCC. MATERIALS AND METHODS: Three themes were covered in this international survey: demographics of respondents and liver imaging expertise; imaging practices for screening, surveillance, diagnosis, staging, and assessment of treatment response for HCC; and diagnostic imaging systems used. Descriptive summaries were created. RESULTS: Of 151 respondents, 22.5% were from Asia, 6.0% from Europe, 19.9% from North America, 26.5% from South America, and 25.2% from Australasia; 57.0% respondents worked in academic and 34.4% in private or mixed settings. Non-contrast ultrasound was most commonly used for screening and surveillance of HCC (90.7%), and multiphase computed tomography was used for diagnosis (96.0%). Extracellular contrast agents (69.5%) were the most commonly used MRI contrast agents and Lumason/SonoVue (31.1%) is the most commonly used contrast-enhanced ultrasound contrast agent. A majority (94.0%) of respondents use ancillary imaging features for assessment of liver lesions in at-risk patients. Usage of diagnostic imaging systems for HCC varied by region. RECIST or mRECIST criteria were most commonly used for assessing HCC treatment response (48.3%). Most respondents agreed that a standardized classification for the diagnosis of HCC is needed (68.9%) and that an atlas and lexicon would help improve inter-reader agreement (71.5%). CONCLUSION: Practices and recommendations for imaging of HCC vary between geographical regions. Future efforts to develop a unified system should address regional differences and potential barriers for adoption of a standardized diagnostic system for HCC.

15.
Adv Radiat Oncol ; 5(3): 313-317, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32529123

RESUMO

Purpose: The progress of women in academic medicine appears to be curtailed. We evaluated gender differences in academia for residents in radiation oncology compared with 2 of its related specialties, radiology and medical oncology, across Canada. Methods and Materials: We analyzed abstracts presented between 2013 and 2016 at the annual meetings of the Canadian Association of Radiation Oncologists and compared it to the corresponding data for the meetings of the Canadian Association of Radiologists and Canadian Association of Medical Oncology. We further evaluated gender composition of abstracts, presentations, and publications available on PubMed. Conversion rates according to gender and to medical specialties were assessed. Proportions were compared using Fisher exact test or the chi-squared test. Results: Among the 198 presented abstracts, 103 (52%) were published. Radiation oncology had the highest publishing rate with 90% (oncology 56%, radiology 40%). The publication rate between the medical specialties was significantly different (P < .001).Fifty-seven percent of abstracts presented by women were published versus 48% of abstracts presented by men. Overall, there was no significant difference between genders in terms of subsequent conversions into a scientific publication within each specialty (P = .25-1.0).In radiation oncology, women presented 67% of abstracts and published 95% of their presented abstracts, and in medical oncology, 66% of abstracts were from women and 57% of the presented abstracts were published. Among the published abstracts, 83% had the same first author in the abstract and the publication. Among those who lost their first-authorship status, 59% were women. However, there was no statistically significant difference between specialties for loss of first-author status. Conclusions: We observed that from 2013 to 2016, women had the highest presentation and publication rate in radiation oncology. More prospective data are needed to monitor the progress of women in all specialties and their specific needs.

16.
Ultrasound Med Biol ; 46(7): 1715-1726, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32381381

RESUMO

Shear wave elastography (speed and dispersion), local attenuation coefficient slope and homodyned-K parametric imaging were used for liver steatosis grading. These ultrasound biomarkers rely on physical interactions between shear and compression waves with tissues at both macroscopic and microscopic scales. These techniques were applied in a context not yet studied with ultrasound imaging, that is, monitoring steatosis of force-fed duck livers from pre-force-fed to foie gras stages. Each estimated feature presented a statistically significant trend along the feeding process (p values <10-3). However, whereas a monotonic increase in the shear wave speed was observed along the process, most quantitative ultrasound features exhibited an absolute maximum value halfway through the process. As the liver fat fraction in foie gras is much higher than that seen clinically, we hypothesized that a change in the ultrasound scattering regime is encountered for high-fat fractions, and consequently, care has to be taken when applying ultrasound biomarkers to grading of severe states of steatosis.

17.
Abdom Radiol (NY) ; 45(8): 2409-2417, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32435849

RESUMO

PURPOSE: To compare the level of parenchymal and portal venous enhancement in the portal venous phase (PVP) in cirrhotic patients undergoing gadoxetate disodium- and gadobenate dimeglumine-enhanced MRI. METHODS: In this retrospective study, 84 cirrhotic patients (mean age ± SD: 66 ± 13 years) who underwent contrast-enhanced MRI with both gadoxetate disodium and gadobenate dimeglumine between 2012 and 2018 were included. Two readers measured signal intensities of hepatic parenchyma, portal vein and psoas muscle on precontrast and PVP. Relative enhancement (RE), image contrast, and portal vein-to-liver contrast difference were calculated. Intraindividual differences were compared with the Wilcoxon signed rank-sum test and inter-reader differences with the intraclass correlation coefficient (ICC). RESULTS: In PVP, gadoxetate disodium provided lower RE than gadobenate dimeglumine (Reader 1: 42.4 ± 44.6 vs. 56.1 ± 58.8, p = 0.044; Reader 2: 42.4 ± 42.9 vs. 57.7 ± 60.5, p = 0.027;), lower image contrast (Reader 1: 0.27 ± 0.11 vs. 0.35 ± 0.11, respectively; p < 0.001; Reader 2: 0.29 ± 0.10 vs. 0.37 ± 0.07, respectively; p < 0.001), and lower portal vein-to-liver contrast difference (Reader 1: 0.89 ± 0.39 vs. 1.42 ± 0.90, p < 0.001; Reader 2: 0.95 ± 0.40 vs. 1.28 ± 0.37, p < 0.001). ICC was 0.94, 0.79, and 0.69 for RE, image contrast, and portal vein-to-liver contrast difference, respectively. CONCLUSION: In cirrhotic patients, gadoxetate disodium yielded lower enhancement of the hepatic parenchyma and lower contrast of the portal vein than gadobenate dimeglumine in PVP.

18.
Analyst ; 145(10): 3742-3748, 2020 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-32343290

RESUMO

A novel nucleic acid-based isothermal signal amplification strategy, named cross-boosting extension-nicking reaction (CBENR) is developed and successfully used for rapid and ultrasensitive detection of polynucleotide kinase (PNK) activity. Only two simple oligonucleotides (recognition substrate (RS) and TaqMan probe) are applied to construct the PNK-sensing platform. In the presence of PNK, the 3'-phosphate end of RS will be converted to the 3'-hydroxyl one, and then extended to a long poly-adenine (poly-A) sequence under the catalysis of terminal deoxynucleotidyl transferase (TdT). The poly-A sequence provides multiple binding sites for the TaqMan probe to form multiple DNA duplexes. Subsequently, ribonuclease HII (RNase HII) cuts the TaqMan probe into two parts at the pre-set uracil site, generating a fluorescence signal and providing new substrates for TdT elongation. The TdT-catalyzed substrate extension and RNase HII-catalyzed probe nicking are boosted by each other, resulting in persistent enlargement of these two reactions and thus giving ultrahigh signal amplification efficiency. Utilizing the CBENR-based PNK sensor, ultrasensitive detection of PNK activity was achieved with a detection limit as low as 3.0 × 10-6 U mL-1. Quantification of endogenous PNK activity at the single-cell level and the screening/evaluation of PNK inhibitors were also achieved.

19.
Anal Chem ; 92(9): 6470-6477, 2020 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-32249564

RESUMO

Nucleic acid aptamers have been widely used in various fields such as biosensing, DNA chip, and medical diagnosis. However, the high susceptibility of nucleic acids to ubiquitous nucleases reduces the biostability of aptamers and limits their applications in biological contexts. Therefore, improving the biostability of aptamers becomes an urgent need. Herein, we present a simple strategy to resolve this problem by directly replacing the d-DNA-based aptamers with left-handed l-DNA. By testing several reported aptamers against respective targets, we found that our proposed strategy stood up well for nonchiral small molecule targets (e.g., Hemin and cationic porphyrin) and chiral targets whose interactions with aptamers are chirality-independent (e.g., ATP). We also found that the l-DNA aptamers were indeed endowed with greatly improved biostability due to the extraordinary resistance of l-DNA to nuclease digestion. With respect to other small-molecule targets whose interactions with aptamers are chirality-dependent (e.g., kanamycin) and biomacromolecules (e.g., tyrosine kinase-7), however, the proposed strategy was not entirely effective likely due to the participation of the DNA backbone chirality into the target recognition. In spite of this limitation, this strategy indeed paves an easy way to screen highly biostable aptamers important for the applications in many fields.

20.
ACS Appl Mater Interfaces ; 12(18): 20922-20932, 2020 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-32297732

RESUMO

Nontargeted analysis of food safety requires selective removal of interference matrices and highly efficient recovery of chemical hazards. Porous materials such as covalent organic frameworks (COFs) show great promise in selective adsorption of matrix molecules via size selectivity. Considering the complexity of interference matrices, we prepared crystalline heteropore COFs whose two kinds of pores have comparable sizes to those of several common phytochromes, main interference matrices in vegetable sample analysis. By controlling the growth of COFs on the surface of Fe3O4 nanoparticles or by utilizing a facile co-electrospinning method, heteropore COF-based magnetic nanospheres or electrospun nanofiber films were prepared, respectively. Both the nanospheres and the films maintain the dual-pore structures of COFs and show good stability and excellent reusability. Via simple magnetic separation or immersion operation, respectively, they were successfully used for the complete removal of phytochromes and highly efficient recovery of 15 pesticides from the extracts of four vegetable samples, and the recoveries are in the range of 83.10-114.00 and 60.52-107.35%, respectively. Film-based immersion operation gives better sample pretreatment performance than the film-based filtration one. This work highlights the great application potentials of heteropore COFs in sample pretreatment for nontargeted analysis, thus opening up a new way to achieve high-performance sample preparation in many fields such as food safety analysis, environment monitoring, and so on.

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