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1.
Anal Chem ; 95(2): 1359-1365, 2023 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-36575992

RESUMO

Pressure has been a facile signal readout mode for developing point-of-care testing devices due to the attractive features of portability, accessibility, rapidity, and affordability. Herein, a pressure signal readout device was designed by integrating two homemade needle-type piezoresistive transducers, a controller for a thin-film piezoresistive sensor and a smartphone. Meanwhile, a bidirectional immunochromatographic test strip was designed as an immunoreaction platform for dual-analyte detection. Using PdCuPt nanoparticles with catalase-mimic activity as signal tags, the pressure signals triggered by catalyzed aerogenous reaction were monitored by the pressure signal readout device and read on a smartphone with the Bluetooth module. In this proof-of-principle work, imidacloprid and carbendazim were detected as model analytes. The dynamic ranges for quantitating imidacloprid and carbendazim are 20 pg mL-1 to 50 ng mL-1 and 50 pg mL-1 to 50 ng mL-1, respectively. The whole immunoassay process was completed within 16 min. The recovery values for imidacloprid and carbendazim spiked into herbal medicines are 82.0-110.0 and 84.0-116.0%, respectively, verifying its reliability for real sample detection. As the smartphone APP and controller for a thin-film piezoresistive sensor contain 12 signal channels, the system can be easily extended to meet the demand for high-throughput screening.


Assuntos
Benzimidazóis , Smartphone , Reprodutibilidade dos Testes , Imunoensaio/métodos , Limite de Detecção
2.
Anal Chem ; 95(26): 10008-10016, 2023 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-37342882

RESUMO

Phages have already been employed to detect bacteria because of their specific recognition capability and strong infectious activity toward their host. However, the reported single-phage-based techniques are inevitably restricted by false negative results that arose from extremely high strain specificity of phages. In this study, a cocktail composed of three Klebsiella pneumoniae (K. pneumoniae) phages was prepared as a recognition agent to broaden the recognition spectrum for detecting this bacterial species. A total of 155 clinically isolated strains of K. pneumoniae collected from four hospitals were adopted to test its recognition spectrum. A superior recognition rate of 91.6% for the strains was achieved due to the complementarity of the recognition spectra of the three phages composed of the cocktail. However, the recognition rate is as low as 42.3-62.2% if a single phage is employed. Based on the wide-spectrum recognition capability of the phage cocktail, a fluorescence resonance energy transfer method was established for detecting K. pneumoniae strains by employing fluorescein isothiocyanate labeled to the phage cocktail and Au nanoparticles labeled to p-mercaptophenylboronic acid as energy donors and acceptors, respectively. The detection process can be completed within 35 min, with a wide dynamic range of 5.0 × 102-1.0 × 107 CFU/mL. The application potential was verified by applying it to quantitate K. pneumoniae in different sample matrixes. This pioneer work opens an avenue for achieving wide-spectrum detection of different strains belonging to the same bacterial species with the phage cocktail.


Assuntos
Klebsiella pneumoniae , Klebsiella pneumoniae/química , Bacteriófagos/isolamento & purificação , Especificidade da Espécie , Ouro , Nanopartículas Metálicas
3.
Anal Chem ; 94(27): 9610-9617, 2022 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-35749272

RESUMO

As a multidrug-resistant pathogen, Acinetobacter baumannii has long been identified as one of the most common nosocomial bacteria. High-performance recognition probes for wide-spectrum detection of A. baumannii are highly desired to achieve efficient diagnosis and timely treatment of infectious diseases induced by this pathogen. An engineering tail fiber protein (ETFP) named as Gp50 encoded by lytic phage Abp9 was expressed in Escherichia coli and identified as a binding protein for A. baumannii. According to the results of genome sequencing of an A. baumannii wild strain and phage-resistant strains, the binding receptor of ETFP Gp50 is inferred to be a lipopolysaccharide distributed on the bacterial surface. The engineering protein did not show lytic activity to A. baumannii, which facilitates the development of reliable diagnosis kits and biosensors with high flexibility and low false-negative rate. The results of specificity study show that ETFP Gp50 is a species-specific binding protein with a recognition rate of 100% for all tested 77 A. baumannii strains, while that of the natural phage Abp9 is only 27.3%. With the engineering protein, a fluorescence method was developed to detect A. baumannii with a detection range of 2.0 × 102 to 2.0 × 108 cfu mL-1. The method has been used for the quantification of A. baumannii in a diverse sample matrix with acceptable reliability. The work demonstrates the application potential of ETFP Gp50 as an ideal recognition probe for rapid screening of A. baumannii strains in a complicated sample matrix.


Assuntos
Acinetobacter baumannii , Bacteriófagos , Acinetobacter baumannii/genética , Antibacterianos/farmacologia , Bacteriófagos/genética , Escherichia coli/genética , Reprodutibilidade dos Testes , Vírion
4.
Plant Dis ; 2022 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-35771105

RESUMO

Cercidiphyllum japonicum is a deciduous tree belonging to the genus Cercidiphyllum of the family Cercidiphyllaceae (Li et al., 2008). Fossil records indicated that this tree was once distributed throughout the Northern hemisphere during the tertiary period, whereas it is now only found in Japan and China as a consequence of quaternary glaciation. In 1989, C. japonicum was listed as a Rare and Endangered plant in China (Song et al., 1989). It is also highly valued for use in ornamental, medicinal, and research contexts, leading to its widespread planting and cultivation throughout China. In September 2021, a severe leaf spot infection (FigS1.A) was first detected on C. japonicum trees in Meigu County, Sichuan Province, China (N 28°33', E 103°14'). In a survey of twenty 100-year-old C. japonicum trees in this region, the incidence of such leaf spot was found to be approximately 95%. During the early stages of disease, infected leaves exhibited small punctate spots along the leaf center or margins. These spots were brown in the center with black edges. As the disease progressed, these spots expanded until they coalesced to yield large circular or irregularly shaped regions of necrotic tissue, and finally produced mildew. Samples of leaf tissue between symptomatic and healthy regions (5 mm×5 mm) were excised from five symptomatic leaves, surface disinfected for 30 s with 75% ethanol, soaked for 2 min in 3% NaClO, rinsed then plated on potato dextrose agar (PDA) medium supplemented with ampicillin and carbenicillin (50 µg/ml each). After cultured for 3 days in the dark at 25°C, emergent hyphae were purified by subculturing them on fresh PDA medium. In total, single spore culturing was performed by collecting and purifying seven fungal isolates. These isolates exhibited largely comparable morphological characteristics. Aerial hyphae had a cotton-like appearance and were white to pale gray in color (FigS1.B), turning pale reddish-brown with profuse sporulation (FigS1.C). Conidia were present in long chains, with conidiophores being present in clusters or in isolation (FigS1.D), with 1-5 transverse septa, 0-3 oblique and longitudinal septa and an ellipsoidal to obpyriform structure, measuring 9.0-38.6 µm in length and 5.1-12.6 µm in width (n = 40) (FigS1.E). These seven isolates thus exhibited morphological characteristics consistent with those of members of the Alternaria genus (Simmons, 2008). Molecular identification of a representative isolate (LGB9) was performed by amplifying the internal transcribed spacer (ITS) rDNA, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), translation elongation factor 1-alpha (TEF1), and partial RNA polymerase II largest subunit (RPB2) gene sequences with the ITS1/ITS4 (White et al.,1990), GDF/GDR (Templeton et al., 1992), TEF-728F/TEF-986R (Carbone & Kohn 1999) and RPB2-5F2/RPB2-7cR (Sung et al., 1990; Liu et al., 1999), and Bt-2a/Bt-2b (Glass and Donaldson 1995) primer pairs, respectively. The resultant sequences were deposited in GenBank (ITS, OL659190; GAPDH, OL685343; TEF, ON340848; RPB2, OL685344). Further phylogenetic analyses of isolate LGB9 revealed it to cluster in the A. brassicae clade with 97% bootstrap support. To confirm the pathogenicity of isolate LGB9, 15 healthy leaves from five one-year-old C. japonicum plants were spray-inoculated with a suspension containing 3×105 LGB9 conidia/mL, with control leaves instead being sprayed with distilled water. After 8 days, inoculated leaves exhibited symptoms similar to those observed on naturally infected leaves (FigS1.F-I), whereas the mock leaves were free of any symptoms. This is the first report to our knowledge of a case of leaf spot disease caused by A. brassicae affecting C. japonicum in China or anywhere else in the world. To ensure the protection of this living fossil species, appropriate interventional measures should be adopted to manage the development and spread of this disease.

5.
Socioecon Plann Sci ; 83: 101228, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35034989

RESUMO

This paper proposes a novel grey spatiotemporal model and quantitatively analyzes the spillover and momentum effects of the COVID-19 lockdown policy on the concentration of PM2.5 (particulate matter of diameter less than 2.5 µm) in Wuhan during the COVID-19 pandemic lockdown from 23 January to 8 April 2020 inclusive, and the post-pandemic period from 9 April 2020 to 17 October 2020 inclusive. The results suggest that the stringent lockdowns lead to a reduction in PM2.5 emissions arising from a momentum effect (9.57-18.67%) and a spillover effect (7.07-27.60%).

6.
Lipids Health Dis ; 17(1): 84, 2018 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-29665812

RESUMO

BACKGROUND: Long-term persistence of statin therapy provided an ongoing reduction in mortality among patients with and without a known history of CVD, and renoprotective effect on CKD patients. Until now, very few reports are available from China to address the effects of statin therapy in CKD + CAD patients. METHODS: We compared the effects of long-term statin therapy (follow-up time 4 years) in terms of cardiovascular events, all-cause death, and cardiac death among 254 CKD patients with or without CAD. RESULTS: Long-term statin therapy was much more effective in the CKD + CAD patients compared with CKD patients. In the CAD + CKD patients, long-term statins showed a 22.2% reduction in the CVs rate (P = 0.012). With regard to the all-cause and cardiac deaths, long-term statins had significant treatment effects on the CAD + CKD patients (reduction of about 28.1% in mortality rates, P < 0.001). In contrast, long-term statin therapy exerted no significant influence on the clinical outcomes of the CKD-only patients. CONCLUSION: Long-term statin therapy more dramatically reduced the CVs and mortality rates of the CKD patients with concomitant CAD. In contrast, CKD-only patients had a good prognosis and did not appear to require statin treatment.


Assuntos
Doença da Artéria Coronariana/complicações , Doença da Artéria Coronariana/tratamento farmacológico , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/tratamento farmacológico , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Modelos de Riscos Proporcionais , Resultado do Tratamento
7.
Lipids Health Dis ; 14: 137, 2015 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-26510458

RESUMO

BACKGROUND: Small dense low-density lipoprotein cholesterol (sdLDL-C) concentration was useful in the assessment of the presence of cardiovascular diseases (CVD) and its severity. We examined whether SdLDL-C is more closely associated with carotid artery intima-media thickness (CA-IMT), a surrogate measure of atherosclerosis, than LDL-C and traditional CVD risk factors in Chinese healthy subjects. METHODS: We measured CA-IMT, blood pressure (BP), sdLDL-C, glucose metabolism and lipid in 183 native Chinese healthy subjects. CA-IMT was assessed by ultrasonography, and sdLDL-C concentrations were measured by a homogenous assay. Pearson's correlation coefficient analyses and Multiple regression analyses were used to examine the relationships between CA-IMT values and other clinical variables. RESULTS: The sdLDL-C level was significantly higher in males than in females (p <0.05) and there was an age effect on sdLDL-C (p <0.05). When the effects of age, gender and other traditional CVD risk factors were adjusted using multiple regression analysis. CA-IMT remained significantly associated with sdLDL-C(ß = 0.437, p <0.001). CONCLUSIONS: There are gender and age differences in sdLDL-C levels among a healthy Chinese population. Moreover, we found adjusted traditional CVD risk factors such as higher age, male sex, and other traditional CVD risk factors, the association between CA-IMT and SdLDL-C remained significant. sdLDL-C is may be a useful predictor in the assessment of CA-IMT in Chinese population.


Assuntos
Artérias Carótidas/anatomia & histologia , Espessura Intima-Media Carotídea , LDL-Colesterol/sangue , Adulto , Fatores Etários , Povo Asiático , Biomarcadores/sangue , Glicemia/metabolismo , Pressão Sanguínea/fisiologia , Índice de Massa Corporal , Artérias Carótidas/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Regressão , Medição de Risco , Fatores de Risco , Fatores Sexuais
8.
Ann Vasc Surg ; 28(2): 375-80, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24200130

RESUMO

BACKGROUND: We studied the relationship between serum levels of small, dense low-density lipoprotein cholesterol (sdLDL-C) and carotid stenosis in elderly patients with ischemic cerebral infarction. METHODS: All patients >65 years of age with newly diagnosed ischemic cerebral infarction were enrolled. None received statins before enrollment. Patients were examined for carotid stenosis by ultrasound color Doppler, and serum sdLDL-C levels were measured using an automated method. RESULTS: The 149 patients were distributed according to their carotid stenosis as without (n = 61) or with mild (n = 30), moderate (n = 34), or severe (n = 24) carotid stenosis. sdLDL-C levels increased significantly with increasing stenosis severity (0.54 ± 0.19, 0.71 ± 0.18, 0.98 ± 0.19, and 1.32 ± 0.17 mmol/L, respectively). Spearman rank correlation analysis revealed that sdLDL-C levels and degree of carotid stenosis were positively correlated (r = 0.411; P < 0.001). Male sex, body mass index, diabetes, hypertension, hyperlipidemia, drinking, smoking, and sdLDL-C levels were positively correlated with carotid stenosis. Logistic regression analysis revealed that sdLDL-C levels are an independent risk factor of carotid stenosis (P = 0.041). CONCLUSIONS: sdLDL-C levels are positively correlated with the severity of carotid stenosis, and are an independent risk factor in elderly patients with ischemic cerebral infarction.


Assuntos
Estenose das Carótidas/sangue , Infarto Cerebral/sangue , LDL-Colesterol/sangue , Fatores Etários , Idoso , Biomarcadores/sangue , Estenose das Carótidas/complicações , Estenose das Carótidas/diagnóstico , Infarto Cerebral/diagnóstico , Infarto Cerebral/etiologia , Distribuição de Qui-Quadrado , Feminino , Humanos , Modelos Logísticos , Masculino , Análise Multivariada , Tamanho da Partícula , Fatores de Risco , Índice de Gravidade de Doença , Ultrassonografia Doppler em Cores
9.
Life Sci ; 342: 122538, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38428571

RESUMO

Pulmonary disorders, including asthma, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis (PF), pulmonary hypertension (PH), and lung cancer, seriously impair the quality of lives of patients. A deeper understanding of the occurrence and development of the above diseases may inspire new strategies to remedy the scarcity of treatments. Type I protein arginine methyltransferases (PRMTs) can affect processes of inflammation, airway remodeling, fibroblast proliferation, mitochondrial mass, and epithelial dysfunction through substrate methylation and non-enzymatic activity, thus affecting the occurrence and development of asthma, COPD, lung cancer, PF, and PH. As potential therapeutic targets, inhibitors of type I PRMTs are developed, moreover, representative compounds such as GSK3368715 and MS023 have also been used for early research. Here, we collated structures of type I PRMTs inhibitors and compared their activity. Finally, we highlighted the physiological and pathological associations of type I PRMTs with asthma, COPD, lung cancer, PF, and PH. The developing of type I PRMTs modulators will be beneficial for the treatment of these diseases.


Assuntos
Asma , Hipertensão Pulmonar , Neoplasias Pulmonares , Doença Pulmonar Obstrutiva Crônica , Fibrose Pulmonar , Humanos , Hipertensão Pulmonar/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Asma/patologia
10.
Aging Dis ; 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38739931

RESUMO

Diabetic foot ulcers (DFUs) are a prevalent and profoundly debilitating complication that afflicts individuals with diabetes mellitus (DM). These ulcers are associated with substantial morbidity, recurrence rates, disability, and mortality, imposing substantial economic, psychological, and medical burdens. Timely detection and intervention can mitigate the morbidity and disparities linked to DFU. Nevertheless, current therapeutic approaches for DFU continue to grapple with multifaceted limitations. A growing body of evidence emphasizes the crucial role of cellular senescence in the pathogenesis of chronic wounds. Interventions that try to delay cellular senescence, eliminate senescent cells (SnCs), or suppress the senescence-associated secretory phenotype (SASP) have shown promise for helping chronic wounds to heal. In this context, targeting cellular senescence emerges as a novel therapeutic strategy for DFU. In this comprehensive review, we look at the pathology and treatment of DFU in a systematic way. We also explain the growing importance of investigating SnCs in DFU and highlight the great potential of senotherapeutics that target SnCs in DFU treatment. The development of efficacious and safe senotherapeutics represents a pioneering therapeutic approach aimed at enhancing the quality of life for individuals affected by DFU.

11.
J Math Biol ; 66(1-2): 383-97, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22350094

RESUMO

In this paper, we consider the concepts of evolutionarily stable strategy (ESS), neighborhood invader strategy (NIS) and global invader strategy (GIS) in single species with frequency-dependent interactions. We find some general relationships among the three concepts in matrix games. The main conclusion is that ESS and NIS are equivalent to each other and are both equivalent to local superiority; a strategy with global superiority must be a GIS; a GIS may not be equivalent to its global superiority in games with more than two players; and in any two-player matrix game a GIS is just equivalent to its global superiority. In two-player games, globally asymptotic stability in the replicator dynamics has also been shown. Equivalent conditions for the three concepts stated by payoff comparisons are given and are applied to examples involved.


Assuntos
Evolução Biológica , Teoria dos Jogos , Modelos Biológicos , Animais , Aptidão Genética , Conceitos Matemáticos , Dinâmica Populacional , Seleção Genética
12.
J Chromatogr A ; 1706: 464268, 2023 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-37544237

RESUMO

Poly(ethyleneimine) (PEI) modified silica spheres were used to graft butyric acid and octanoic acid onto their surfaces, forming two stationary phases named Sil-PEI-BAD and Sil-PEI-CAD, respectively. Characterized methods including fourier transform infrared spectroscopy (FT-IR), elemental analysis (EA) and thermogravimetric analysis (TGA) were utilized to determine the successful synthesis of these two stationary phase materials. The chromatographic performance of these two stationary phases was analyzed with hydrophobic and hydrophilic compounds as analytes. Compared with Sil-PEI-CAD column, Sil-PEI-BAD column was more effective in separating hydrophilic compounds including nucleosides, alkaloids and vitamins. Hydrophobic substances including polycyclic aromatic hydrocarbons (PAHs) and alkylbenzenes obtained excellent separation results on Sil-PEI-CAD column than Sil-PEI-BAD column. Additionally, according to the separation of phenols, Sil-PEI-CAD column can be used in HILIC/RPLC mixed-mode. The results showed that the properties and retention mechanisms of the prepared stationary phases depended on the length of the alkyl chains bonded on the silica surface.


Assuntos
Cromatografia de Fase Reversa , Nucleosídeos , Cromatografia de Fase Reversa/métodos , Interações Hidrofóbicas e Hidrofílicas , Nucleosídeos/análise , Dióxido de Silício/química , Espectroscopia de Infravermelho com Transformada de Fourier
13.
Plants (Basel) ; 11(9)2022 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-35567233

RESUMO

As a valuable ornamental plant, Sinningia hybrida 'Isa's Murmur' (S. hybrida) has genetic flower diversity, which has great potential to develop different flower characters in the horticultural market. The present study focuses on establishing a practical approach for the sustainable propagation of S. hybrida. Compared with aseptic seeding leaves explants, field-grown leaves explants are more suitable for adventitious shoot regeneration. Adding 0.1 mg L-1 NAA and 2.0 mg L-1 TDZ could obtain the highest adventitious shoot proliferation coefficient (24.5), and the induction rate was 91.7%. The shoot proliferation coefficient (20.7) and the greatest shoot length and induction rate (95.3%) were achieved in 0.1 mg L-1 NAA and 2.0 mg L-1 BA medium, accompanied by rooting formation. Adding 0.5 mg L-1 GA3, 1.0 mg L-1 BA, and 0.2 mg L-1 IBA to MS medium can effectively prolong the regenerated buds for rooting. The best for rooting was 1/2 MS medium containing 0.3 mg L-1 IBA, with the maximum number of roots (13.4 per shoot) and survival rate for transplanting (100%). This work aims to build an efficient, definitive, and scalable protocol for S. hybrida regeneration useful for large-scale cultivation and even more protoplast fusion and genetic transformation to develop more colorful or fragrant flowers.

14.
Anal Chim Acta ; 1207: 339799, 2022 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-35491039

RESUMO

As a "superbug", methicillin-resistant Staphylococcus aureus (MRSA) has long been one of the most ubiquitous drug-resistant bacteria inducing numerous nosocomial infections. To achieve effective diagnosis and following treatment decision of infectious diseases induced by MRSA, it is highly desired to establish rapid analysis and antibiotic susceptibility test methods for this pathogen. In this study, we successfully expressed a bifunctional protein by fusing green fluorescent protein and cellular wall-binding domain of bacteriophage P108. The bifunctional protein can be employed as a signal probe for broad-spectrum fluorimetry of MRSA strains because it can both bind with the target pathogen and emit intensive fluorescence. By using it as the signal probe and porcine IgG as the capture agent, MRSA can be analyzed within a dynamic range of 1.0 × 103-2.0 × 107 CFU mL-1 with a sandwich mode. The fluorimetry was also applied to test antibiotic susceptibility of this pathogen to five antibiotics, and all results are conformable with those obtained with a standard micro broth dilution method. The above results demonstrate the attractive perspective of the bifunctional protein for rapid diagnosis and effective medication of infectious diseases induced by MRSA.


Assuntos
Bacteriófagos , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Animais , Antibacterianos/farmacologia , Fluorometria , Proteínas de Fluorescência Verde/genética , Infecções Estafilocócicas/diagnóstico , Staphylococcus aureus , Suínos
15.
J Chromatogr A ; 1669: 462933, 2022 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-35279558

RESUMO

The bovine serum albumin (BSA) was firstly bonded on the surface of graphene quantum dots (GQDs) functionalized silica as the stationary phase named as BSA@GQDs@SiO2 which can perform hydrophilic interaction between the stationary phase and analytes. Characteristic methods including Fourier transform infrared spectroscopy (FT-IR), elemental analysis (EA), thermogravimetric analysis (TGA) and scanning electron microscope (SEM) were applied to estimate the chemical bonding results and morphological features of the prepared materials. In the chromatographic evaluation part, the BSA@GQDs@SiO2 column showed excellent separation efficiency for the analysis of hydrophilic compounds involving nucleosides and bases, acids, phenols, quinolones, vitamins and alkaloids, which proved the prepared column can exhibit hydrophilic interaction mode with other interactions including hydrogen bonding and electrostatic interaction. What's more, essential experimental approaches were designed to evaluate the retention properties of the prepared column via comparing with a commercial amino column and a prepared GQDs@SiO2 column. Results indicated the prepared column showed excellent separation ability for different kinds of hydrophilic compounds than commercial and single hydrophilic columns. The study showed that BSA@GQDs@SiO2 stationary phase with double hydrophilic materials will be a potential chromatographic material for analyzing various hydrophilic analytes.


Assuntos
Grafite , Pontos Quânticos , Grafite/química , Interações Hidrofóbicas e Hidrofílicas , Soroalbumina Bovina , Dióxido de Silício/química , Espectroscopia de Infravermelho com Transformada de Fourier
16.
J Chromatogr A ; 1662: 462731, 2022 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-34915189

RESUMO

As a welcomed porous material, covalent organic frameworks (COFs) have many advantages and are widely used in various aspects. Particularly, COFs have aroused great attentions of scientists in chromatographic separation field due to their outstanding advantages, such as high stability, large specific surface area and multiple voids. However, endowing COFs with chirality to construct chiral stationary phase (CSP) function is still facing many challenges. Here, we firstly prepared a ß-cyclodextrin (ß-CD) and covalent organic framework functional silica CSP named as COF@CD@SiO2 by one-pot method to perform high performance liquid chromatography (HPLC) chiral separation. The morphology and structure of the synthesized stationary phase were investigated by a variety of characterization methods including Fourier transform infrared spectrometry (FT-IR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), N2 adsorption experiment, powder X-ray diffraction (XRD) and elemental analysis (EA). The prepared stationary phase realized fast separation of six enantiomers in a short time. The separation mechanism was mainly ascribed to the inclusion complexation of ß-cyclodextrin and the mutli-interaction sites from COFs material. In conclusion, the prepared chiral column can be used to achieve fast separation of enantiomers with good stability and reproducibility. These results can open new avenue for using chiral COFs in liquid chromatographic separation.


Assuntos
Estruturas Metalorgânicas , beta-Ciclodextrinas , Reprodutibilidade dos Testes , Dióxido de Silício , Espectroscopia de Infravermelho com Transformada de Fourier
17.
Plants (Basel) ; 11(19)2022 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-36235322

RESUMO

Aeschynanthus pulcher (Blume) G. Don, the "lipstick plant" is a prized ornamental plant with distinctive flowers. Here, we introduce a novel in vitro regeneration method for A. pulcher using leaf explants and an optimized combination of phytohormone plant growth regulators (PGRs). The optimal conditions for shoot regeneration included 1 mg L-1 polyvinyl pyrrolidone (PVP) plus 3 mg L-1 thidiazuron (TDZ), inducing a response rate of 82.4% and a shoot/explant ratio of 38.6. When the Murashige and Skoog (MS) medium contained indole-3-butyric acid (IBA) alone, leaves first differentiated into adventitious roots and then adventitious shoots. Leaves cultured on MS medium containing 1 g L-1 PVP, 3 mg L-1 TDZ, 5 mg L-1 casein, and 0.1 mg L-1 α-naphthaleneacetic acid (NAA) for 30 d exhibited the highest embryogenic callus (EC) induction rate (95.6%). The optimal shoot proliferation coefficient (21.5) was obtained when shoots derived from EC were cultured on the same medium as that used for EC induction for 5 weeks. The most effective medium for rooting of elongated shoots was MS medium containing 1 g L-1 PVP, 5 mg L-1 casein, 3 mg L-1 6-benzyladenine (BA), and 0.1 mg L-1 NAA, and the number of roots reached 18.8. The regenerated plants grown in a greenhouse had 100% survival following one week of hardening. Overall, our effective and efficient propagation method should result in shortened culture periods and reduced production costs, allowing for the future selective breeding and genetic improvement of A. pulcher.

18.
Biosens Bioelectron ; 182: 113189, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33799025

RESUMO

As one of the most common and noticeable superbugs, methicillin-resistant Staphylococcus aureus (MRSA) has long been a major threat to public health. To meet the demand for effective diagnosis of MRSA-induced infection, it is urgent to establish rapid assay method for this type of pathogen. In this study, an aqueous soluble cellular wall-binding domain (CWBD) protein from bacteriophage P108 was obtained with a recombinant expression technique. It can act as a wide-spectrum binding agent for all MRSA strains and exclude the interference from methicillin-susceptible strains of Staphylococcus aureus and other species of bacteria. To establish a lateral flow assay (LFA) method for MRSA, CWBD-coupled time-resolved fluorescent microspheres (FMs) were used as signal probes for tracing MRSA, and a nitrocellulose membrane immobilized with porcine IgG was used to capture MRSA. With the LFA based on sandwich format, MRSA can be assayed within 10 min with a broad linear range of 6.6 × 102-6.6 × 107 CFU/mL. Its application potential has been demonstrated by assaying different types of bacteria-contaminated real samples. The results suggest that the LFA strip using recombinant CWBD as the recognition agent provides a rapid, portable, cost-effective approach for point-of-care testing of MRSA.


Assuntos
Bacteriófagos , Técnicas Biossensoriais , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Animais , Antibacterianos/uso terapêutico , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus , Suínos
19.
Plants (Basel) ; 10(9)2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34579450

RESUMO

This work was aimed at establishing an effective approach for in vitro propagation of Ajuga lupulina Maxim, a medicinal and ornamental plant mainly found in eastern Xizang, in the western Sichuan region of China. We report an optimum response in the proliferation of axillary shoots from nodal segment explants (10.2 shoots/explant) on MS medium containing 3.0 mg L-1 of 6-benzyladenine (BA). When BA and TDZ individually or in combination with NAA were employed for adventitious shoot regeneration, shoots and embryo-like structures (ELSs) were noted in the callus from leaf explants. The maximum response of 26.4 shoots /explant (81.6%) and 12.0 ELSs/explant were ascertained on MS medium with 4.0 mg L-1 TDZ and 0.1 mg L-1 NAA. The leaf despite browning still demonstrated a high regeneration capacity. TDZ (2.0 mg L-1) and BA (2.0 mg L-1) along with NAA (0.01 mg L-1) were found to perform well for shoot regeneration via callus from shoot tip explants. The best for rooting was MS medium (half-strength) containing indole-3-butyric acid (IBA: 1.5 mg L-1) and (NAA: 0.5 mg L-1) with the maximum number of roots (25.8 per shoot) and the highest rooting frequency (81.71%). The survival of the plantlets in the greenhouse was 78.2% indicative of successful acclimatization. This work is the first report of a consistent, definitive, and unique protocol for A. lupulina regeneration, paving the way for the in vitro preservation of such significant genetic resources and also further allied systems based on such callus-based or embryo-based approaches.

20.
Transbound Emerg Dis ; 68(5): 2676-2686, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33369865

RESUMO

As of 21 April 2020, 176 ASF outbreaks have occurred in China. For each outbreak, an investigation was conducted, including historical data retrieval and traceability of potential contacts. The purpose of this study is to conduct a preliminary analysis of the data obtained from the outbreak investigations, including an investigation of the possible contributing factors of the spread of ASF in China. Based on the epidemic situation and the policies issued, the entire epidemic can be divided into three phases. 71 outbreaks were reported between 3 August 2018 and 17 November 2018; 44 outbreaks between 19 November 2018 and 30 March 2019; and 61 outbreaks between 4 April 2019 and 12 April 2020. Based on the reported outbreaks, the proportional rate of outbreaks in small farms (livestock ≤ 500, 127/168) is significantly higher than that of medium (501 ≤ livestock < 2,000, 14/168; 2001 ≤ livestock ≤ 5,000, 9/168) and large farms (livestock ≥ 5,001, 18/168). The odds of infection related to swill feeding (OR = 2.5, 95% CI, 1.5-4.3) and the mechanical dissemination of vehicles and personnel (OR = 2.7, 95% CI, 1.6-4.5) are significantly higher than those of pigs and pig production transportation. Swill feeding is the major contributing factor for small farms while mechanical dissemination of vehicles and personnel is the major contributing factor for large farms. The average duration from the beginning of the infection to the official outbreak report is gradually decreasing, which means that response speed of industry entities and the animal husbandry and veterinary departments from the beginning of the infection to the outbreak report is gradually increasing. Based on the analysis for ASF outbreaks, some policies and suggestions were put forward, such as improving the biosecurity level of the farms, as well as strengthening the supervision of breeding, transportation and slaughter.


Assuntos
Vírus da Febre Suína Africana , Febre Suína Africana , Epidemias , Doenças dos Suínos , Febre Suína Africana/epidemiologia , Febre Suína Africana/prevenção & controle , Criação de Animais Domésticos , Animais , China/epidemiologia , Surtos de Doenças/prevenção & controle , Surtos de Doenças/veterinária , Fatores de Risco , Suínos , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/prevenção & controle
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