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1.
Nanoscale ; 13(45): 19085-19097, 2021 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-34761764

RESUMO

Polypyrrole (PPy) nanoparticles have been widely studied in tumor photothermal therapy (PTT) for their significant photostability, good biocompatibility, and excellent photothermal performance. Herein, we report bovine serum albumin (BSA) stabilized PPy that were mineralized by MnO2 nanozyme on the surface (PPy@BSA-MnO2) to achieve synergistic photothermal and chemodynamic therapy (CDT) for breast cancer. In this multifunctional nanoplatform, the surface-loaded MnO2 undergoes a redox reaction with glutathione (GSH) to generate glutathione disulfide (GSSG) and Mn2+. Then, Mn2+ can convert H2O2 into a highly cytotoxic ˙OH to achieve chemodynamic therapy (CDT) and possess good magnetic resonance (MR) T1-weighted imaging capabilities to realize contrast imaging of the 4T1 tumor-bearing mouse models. In addition, PPy nanoparticles can efficiently convert near-infrared light energy into heat and achieve PTT. Most importantly, PPy@BSA-MnO2 nanoprobes have excellent in vitro 4T1 cell-killing effect and in vivo tumor-suppressive properties. The acute toxicity assessment results indicate that PPy@BSA-MnO2 nanoprobes have good biological safety. Therefore, the as-prepared multifunctional PPy@BSA-MnO2 nanoprobes possess excellent performance to promote MRI-guided PTT/CDT synergistic therapy for breast cancer treatment and have extensive clinical transformation and application prospects.


Assuntos
Neoplasias , Polímeros , Animais , Peróxido de Hidrogênio , Imageamento por Ressonância Magnética , Compostos de Manganês , Camundongos , Óxidos , Pirróis , Nanomedicina Teranóstica
2.
Bioinformatics ; 2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33624750

RESUMO

MOTIVATION: Gene-gene co-expression networks (GCN) are of biological interest for the useful information they provide for understanding gene-gene interactions. The advent of single cell RNA-sequencing allows us to examine more subtle gene co-expression occurring within a cell type. Many imputation and denoising methods have been developed to deal with the technical challenges observed in single cell data; meanwhile, several simulators have been developed for benchmarking and assessing these methods. Most of these simulators, however, either do not incorporate gene co-expression or generate co-expression in an inconvenient manner. RESULTS: Therefore, with the focus on gene co-expression, we propose a new simulator, ESCO, which adopts the idea of the copula to impose gene co-expression, while preserving the highlights of available simulators, which perform well for simulation of gene expression marginally. Using ESCO, we assess the performance of imputation methods on GCN recovery and find that imputation generally helps GCN recovery when the data are not too sparse, and the ensemble imputation method works best among leading methods. In contrast, imputation fails to help in the presence of an excessive fraction of zero counts, where simple data aggregating methods are a better choice. These findings are further verified with mouse and human brain cell data. AVAILABILITY: The ESCO implementation is available as R package ESCO. Users can either download the development version via github (https://github.com/JINJINT/ESCO) or the archived version via Zenodo (https://zenodo.org/record/4455890). SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

3.
Stat Methods Med Res ; 30(4): 976-993, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33413033

RESUMO

Biological research often involves testing a growing number of null hypotheses as new data are accumulated over time. We study the problem of online control of the familywise error rate, that is testing an a priori unbounded sequence of hypotheses (p-values) one by one over time without knowing the future, such that with high probability there are no false discoveries in the entire sequence. This paper unifies algorithmic concepts developed for offline (single batch) familywise error rate control and online false discovery rate control to develop novel online familywise error rate control methods. Though many offline familywise error rate methods (e.g., Bonferroni, fallback procedures and Sidak's method) can trivially be extended to the online setting, our main contribution is the design of new, powerful, adaptive online algorithms that control the familywise error rate when the p-values are independent or locally dependent in time. Our numerical experiments demonstrate substantial gains in power, that are also formally proved in an idealized Gaussian sequence model. A promising application to the International Mouse Phenotyping Consortium is described.


Assuntos
Algoritmos , Projetos de Pesquisa , Animais , Camundongos , Distribuição Normal
4.
Sensors (Basel) ; 19(14)2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31311185

RESUMO

Firmness changes in Nanguo pears under different freezing/thawing conditions have been characterized by hyperspectral imaging (HSI). Four different freezing/thawing conditions (the critical temperatures, numbers of cycles, holding time and cooling rates) were set in this experiment. Four different pretreatment methods were used: multivariate scattering correction (MSC), standard normal variate (SNV), Savitzky-Golay standard normal variate (S-G-SNV) and Savitzky-Golay multiplicative scattering correction (S-G-MSC). Combined with competitive adaptive reweighted sampling (CARS) to identify characteristic wavelengths, firmness prediction models of Nanguo pears under different freezing/thawing conditions were established by partial least squares (PLS) regression. The performance of the firmness model was analyzed quantitatively by the correlation coefficient (R), the root mean square error of calibration (RMSEC), the root mean square error of prediction (RMSEP) and the root mean square error of cross validation (RMSECV). The results showed that the MSC-PLS model has the highest accuracy at different cooling rates and holding times; the correlation coefficients of the calibration set (Rc) were 0.899 and 0.927, respectively, and the correlation coefficients of the validation set (Rp) were 0.911 and 0.948, respectively. The accuracy of the SNV-PLS model was the highest at different numbers of cycles, and the Rc and the Rp were 0.861 and 0.848, respectively. The RMSEC was 65.189, and the RMSEP was 65.404. The accuracy of the S-G-SNV-PLS model was the highest at different critical temperatures, with Rc and Rp values of 0.854 and 0.819, respectively, and RMSEC and RMSEP values of 74.567 and 79.158, respectively.


Assuntos
Processamento de Imagem Assistida por Computador , Pyrus/crescimento & desenvolvimento , Espectroscopia de Luz Próxima ao Infravermelho , Algoritmos , Calibragem , Congelamento , Análise dos Mínimos Quadrados , Pyrus/anatomia & histologia
5.
Biotechnol Lett ; 39(6): 857-864, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28247198

RESUMO

OBJECTIVE: To develop a reliable and easy to use expression system for antibiotic production improvement of Streptomyces. RESULTS: A two-compound T7 RNA polymerase-dependent gene expression system was developed to fulfill this demand. In this system, the T7 RNA polymerase coding sequence was optimized based on the codon usage of Streptomyces coelicolor. To evaluate the functionality of this system, we constructed an activator gene overexpression strain for enhancement of actinorhodin production. By overexpression of the positive regulator actII-ORF4 with this system, the maximum actinorhodin yield of engineered strain was 15-fold higher and the fermentation time was decreased by 48 h. CONCLUSION: The modified two-compound T7 expression system improves both antibiotic production and accelerates the fermentation process in Streptomyces. This provides a general and useful strategy for strain improvement of important antibiotic producing Streptomyces strains.


Assuntos
Antibacterianos/metabolismo , RNA Polimerases Dirigidas por DNA/metabolismo , Streptomyces/metabolismo , Proteínas Virais/metabolismo , Antraquinonas/análise , Antraquinonas/metabolismo , Antibacterianos/análise , Biotecnologia , Clonagem Molecular , RNA Polimerases Dirigidas por DNA/genética , Fermentação , Streptomyces/enzimologia , Streptomyces/genética , Proteínas Virais/genética
6.
J AAPOS ; 16(1): 65-9, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22245021

RESUMO

PURPOSE: To report the long-term rates of visual impairment in children who underwent cataract surgery after late diagnosis. METHODS: The records of children who underwent cataract surgery in northern China between January 1994 and December 2009 were retrospectively reviewed. Age at surgery, surgical approach, postoperative best-corrected visual acuity, and compliance with amblyopia treatment were evaluated. Visual impairment was defined as best-corrected visual acuity <20/60. RESULTS: Of 486 children included in this study, 2 (0.4%) had surgery by age 3 months and 68 (14%) by age 6 months. Of the 536 eyes of 331 patients with visual acuity recorded at final follow-up, 151 eyes (37%) had bilateral cataract and 82 (65%) had unilateral cataract, with a total of 233 (45%) considered visually impaired. In children who had surgery before 36 months of age for bilateral cataracts, there was no significant difference in rates of visual impairment with versus without primary IOL implantation. In patients with unilateral cataract, visual impairment occurred regardless of age at surgery or whether IOL was primarily implanted. Postoperatively, compliance with amblyopia treatment was good in 30% of patients, fair in 45%, and poor in 31%. CONCLUSIONS: The long-term visual acuity was unfavorable in approximately half of children diagnosed and treated for pediatric cataracts after 3 months of age. Contributing factors included age at presentation and absence of effective training for postoperative vision rehabilitation.


Assuntos
Extração de Catarata/estatística & dados numéricos , Catarata/diagnóstico , Diagnóstico Tardio/efeitos adversos , Complicações Pós-Operatórias/etiologia , Transtornos da Visão/etiologia , Adolescente , Catarata/fisiopatologia , Catarata/reabilitação , Extração de Catarata/reabilitação , Criança , Pré-Escolar , Humanos , Lactente , Implante de Lente Intraocular/estatística & dados numéricos , Nistagmo Patológico/etiologia , Cooperação do Paciente , Complicações Pós-Operatórias/fisiopatologia , Complicações Pós-Operatórias/reabilitação , Resultado do Tratamento , Transtornos da Visão/fisiopatologia , Transtornos da Visão/reabilitação , Acuidade Visual/fisiologia
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