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1.
Food Chem ; 367: 130667, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34339981

RESUMO

The main purpose of the present study was to investigate the effect of different fertilizers on the physicochemical properties, multi-element and volatile composition of cucumbers. All samples were divided into five groups according to different combinations and amounts of chicken manure, NPK 17-17-17 fertilizer and microbial fertilizer. The co-application of chicken manure (120,000 kg/ha) and NPK 17-17-17 fertilizer (750 kg/ha) achieved the best texture properties, whereas the addition of the microbial fertilizer at 6000 kg/ha significantly improved the color quality of cucumbers. Similarly, the co-application of chicken manure, NPK 17-17-17 fertilizer and microbial fertilizer at 6000 kg/ha enhanced the number and abundance of volatile components detected in the cucumbers. Cucumbers from the control group contained the highest levels of most of the determined elements. Overall, a combination of chicken manure, NPK 17-17-17 fertilizer and 6000 kg/ha microbial fertilizer is recommended as a relatively efficient fertilizer utilization for cucumbers.


Assuntos
Cucumis sativus , Fertilizantes , Agricultura , Fertilizantes/análise , Esterco , Solo
2.
Food Chem ; 374: 131755, 2021 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-34883426

RESUMO

This study explored the anti-obesity effect of 6-shogaol and the underlying mechanisms by using Network pharmacology for the prediction and verification of molecular targets and pathways of 6-shogaol against obesity. Furthermore, the results were verified by molecular docking and cell experiments. A total of 86 core targets of 6-shogaol towards obesity were identified. Among them, AKT1 and PIK3CA were confirmed by using the molecular docking. In 3T3-L1 preadipocyte model, 6-shogaol significantly inhibited proliferation and differentiation, reducing the accumulation of lipid droplets. Compared with the control group, the inhibition rates of 6-shogaol on TG and TC were 90.8% and 40.0%, respectively. Additionally, 6-shogaol down-regulated the expression of PPAR-γ and C/EBP-α, while it decreased the phosphorylation of IRS-1, PI3K and AKT. This study, for the first time, confirmed the effect of 6-shogaol on improving obesity through PI3K/AKT pathway. An anti-obesity bioactivity study was further recommended for the development of novel anti-obesity products.

3.
Food Chem ; 374: 131751, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34883431

RESUMO

The main purpose of the present study was toinvestigate the influence of genotypes on the volatile, flavonoid-related compounds and antioxidant capacities of chilli peppers. A set of 49 volatiles were identified in the chilli peppers using gas chromatography-ion mobility spectrometry (GC-IMS). The flavonoid-related profiles were established by the simultaneous LC-MS measurement of 38 compounds. The results of chemometrics analysis reveal that Jize and Korean chilli peppers can be distinctly separated from each other. A panel of 18 volatile and 13 flavonoid-related variables with VIP > 1 and p < 0.05 were determined as the discriminants for Jize and Korean chilli peppers. Moreover, Korean chilli peppers showed significantly (p < 0.05) higher antioxidant activity than Jize chilli peppers. A clear and positive correlation was observed between the antioxidant potential and individual flavonoid compounds. The current findings could facilitate the valorization of chilli peppers as bioactive and functional ingredients at various commercial levels.

4.
Int J Biol Macromol ; 2021 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-34952095

RESUMO

In this study, the surface layer protein (SLP) from Lactobacillus kefiri HBA20 was characterized. The SLP was extracted by 5 M LiCl. The molecular mass of the SLP was approximately 64 kDa as analyzed via SDS-PAGE. The surface morphology and the adhesion potential of L. kefiri HBA20 in the absence and presence of SLP were measured by AFM. Moreover, the protein secondary structure was evaluated by using circular dichroism (CD) and Fourier transform infrared spectroscopy (FTIR), respectively. SLP had high ß-sheet contents and low content of α-helix. Thermal analysis of SLP of Lactobacillus kefiri HBA20 exhibited one transition peak at 129.64 °C. Furthermore, SEM measurements were showed that after the SLP were removed from the cell surface, the coaggregation ability with Saccharomyces cerevisiae Y8 of the strain was significantly reduced. In conclusion, the SLP of Lactobacillus kefiri HBA20 has a stable structure and the ability of adhesion to yeast. Molecular docking study revealed that mannan bind with the hydrophobic residues of SLP. Our results will help further understanding of the new surface layer protein and the interaction between L. kefiri and S. cerevisiae.

5.
Foods ; 10(11)2021 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-34828849

RESUMO

The detection of aflatoxin B1 (AFB1) has recently garnered much attention on the issue of food safety. In this study, a novel and sensitive aptasensor towards AFB1 is proposed using an Exonuclease III (Exo III)-integrated signal amplification strategy. This reported sensing strategy is regulated by aptamer-functionalized nanobeads that can target AFB1; furthermore, complementary DNA (cDNA) strands can lock the immobilized aptamer strands, preventing the signal amplification function of Exo III in the absence of AFB1. The presence of AFB1 triggers the displacement of cDNA, which will then activate the Exo III-integrated signal amplification procedure, resulting in the generation of a guanine (G)-rich sequence to form a G-4/hemin DNAzyme, which can catalyze the substrate of ABTS to produce a green color. Using this method, a practical detection limit of 0.0032 ng/mL and a dynamic range of detection from 0.0032 to 50 ng/mL were obtained. Additionally, the practical application of the established sensing method for AFB1 in complex matrices was demonstrated through recovery experiments. The recovery rate and relative standard deviations (RSD) in three kinds of cereal samples ranged from 93.83% to 111.58%, and 0.82% to 7.20%, respectively, which were comparable with or better than previously reported methods.

6.
Medicine (Baltimore) ; 100(46): e27840, 2021 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-34797316

RESUMO

BACKGROUND: The relationship between Helicobacter pylori (H. pylori) infection and subclinical atherosclerosis has been confirmed, but these conclusions are still controversial. Therefore, we have performed a systematic review and meta-analysis to assess the association between H. pylori infection and subclinical atherosclerosis. METHODS: Databases including PubMed, Embase, Web of Science were searched for the articles on the association of carotid intima-media thickness or pulse wave velocity with H. pylori infection published up to January 1, 2020. Stata 12.0 was used to calculate standardized mean difference (SMD) and 95% confidence interval (95% CI); the I2 test was used to evaluate heterogeneity between studies and sensitivity analysis and subgroup analysis were used to explore the source of heterogeneity. Funnel plot, Begg test, and Egger test were used to estimate publication bias. RESULTS: Data were extracted from 18 studies involving 6776 subjects with H. pylori positive and 7794 with H. pylori negative. H. pylori positive subjects is significantly associated with increased subclinical atherosclerosis as determined by carotid intima-media thickness (SMD: 0.376 mm; 95% CI: 0.178, 0.574; P < .001, I2 = 90.6%), pulse wave velocity (SMD: 0.320 m/s; 95% CI: 0.242, 0.398; P < .001, I2 = 52.6%), compared with H. pylori negative. Similar results were observed when subgroups analysis were stratified according to age, male ratio, geographical location, H. pylori diagnosis, and study design. Sensitivity analyses showed that our results were robust. The Begg test or Egger test showed no significant publication bias (all P > .05). CONCLUSIONS: This meta-analysis confirmed a significant association between H. pylori and subclinical atherosclerosis, which will help H. pylori patients to establish effective strategies for the prevention and control of cardiovascular events.

7.
Front Pharmacol ; 12: 755662, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34759824

RESUMO

Acute myeloid leukemia (AML) cells can evade innate immune killing by modulating natural killer (NK) cells receptors and their cognate ligands in tumor cells, thus it may be possible to restore proper expression of immune receptors or ligands with immune sensitive drugs. Decitabine, as a hypomethylation agent, was approved for the treatment of AML and myelodysplastic syndrome. While clinical responses were contributed by epigenetic effects and the induction of cancer cell apoptosis, decitabine also has immune-mediated anti-tumor effects. After exposure to various concentration of decitabine for 24 h, the primary NK cells (AML-NK cells) cytotoxicity and receptor expression (NKG2D and NKp46) displayed parabola-shaped response, while U-shaped response was seen in cytokine release (IFN-γ and IL-10), and these effects were regulated by ERK and STAT3 phosphorylation level. Furthermore, AML-NK cells function displayed different response when the competitive MEK and STAT3 inhibitors applied respectively. Thus, we could conclude that the different dose of decitabine makes various effects on AML-NK cells function and receptors expression.

8.
Ultrason Sonochem ; 79: 105770, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34598102

RESUMO

In this study, scallop mantle protein was treated by ultrasound at different powers, and then analyzed by ANS fluorescent probes, circular dichroism spectroscopy, endogenous fluorescence spectrum, DNTB colorimetry and in-vitro digestion model to elucidate the structure-function relationship. The results indicated that ultrasound can significantly affect the secondary structure of scallop mantle protein like enhancing hydrophobicity, lowering the particle size, increasing the relative contents of α-helix and decreasing contents of ß-pleated sheet, ß-turn and random coil, as well as altering intrinsic fluorescence intensity with blue shift of maximum fluorescence peak. But ultrasound had no effect on its primary structure. Moreover, the functions of scallop mantle protein were regulated by modifying its structures by ultrasound. Specifically, the protein had the highest performance in foaming property and in-vitro digestibility under ultrasonic power of 100 W, oil binding capacity under 100 W, water binding capacity under 300 W, solubility and emulsification capacity under 400 W, and emulsion stability under 600 W. These results prove ultrasonic treatment has the potential to effectively improve functional properties and quality of scallop mantle protein, benefiting in comprehensive utilization of scallop mantles.

9.
Microbiology (Reading) ; 167(10)2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34665117

RESUMO

Vibrio cholerae the causative agent of cholera, uses a large number of coordinated transcriptional regulatory events to transition from its environmental reservoir to the host intestine, which is its preferred colonization site. Transcription of the mannose-sensitive haemagglutinin pilus (MSHA), which aids the persistence of V. cholerae in aquatic environments, but causes its clearance by host immune defenses, was found to be regulated by a yet unknown mechanism during the infection cycle of V. cholerae. In this study, genomic expression library screening revealed that two regulators, VC1371 and VcRfaH, are able to positively activate the transcription of MSHA operon. VC1371 is localized and active in the cell membrane. Deletion of vc1371 or VcrfaH genes in V. cholerae resulted in less MshA protein production and less efficiency of biofilm formation compared to that in the wild-type strain. An adult mouse model showed that the mutants with vc1371 or VcrfaH deletion colonized less efficiently than the wild-type; the VcrfaH deletion mutant showed less colonization efficiency in the infant mouse model. The findings strongly suggested that the two regulators, namely VC1371 and VcRfaH, which are involved in the regulation of MSHA expression, play an important role in V. cholerae biofilm formation and colonization in mice.

10.
Membranes (Basel) ; 11(9)2021 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-34564472

RESUMO

We investigate the phase behavior of the asymmetric lipid membranes under shear flows, using the dissipative particle dynamics simulation. Two cases, the weak and strong shear flows, are considered for the asymmetric lipid microstructures. Three typical asymmetric structures, the membranes, tubes, and vesicle, are included in the phase diagrams, where the effect of two different types of lipid chain length on the formation of asymmetric membranes is evaluated. The dynamic processes are demonstrated for the asymmetric membranes by calculating the average radius of gyration and shape factor. The result indicates that different shear flows will affect the shape of the second type of lipid molecules; the shape of the first type of lipid molecules is more stable than that of the second type of lipid molecules. The mechanical properties are investigated for the asymmetric membranes by analyzing the interface tension. The results reveal an absolute pressure at the junctions of different types of particles under the weak shear flow; the other positions are almost in a state of no pressure; there is almost no pressure inside the asymmetric lipid membrane structure under the strong shear flow. The findings will help us to understand the potential applications of asymmetric lipid microstructures in the biological and medical fields.

11.
Adv Skin Wound Care ; 2021 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-34310362

RESUMO

OBJECTIVE: To describe trends and risk factors for pressure injuries (PI) in adult critical care patients placed in prone position between April 9, 2020 and June 8, 2020 to alleviate acute respiratory distress syndrome (ARDS) secondary to COVID-19 and examine effectiveness of products and strategies to mitigate PIs. METHODS: A retrospective chart review was conducted. Demographic data were analyzed using descriptive statistics. Differences between groups with and without PIs were analyzed using t-tests, X2 and Fisher's exact tests, and Cox regression analysis. RESULTS: Among 147 patients, significant PI risk factors included male sex (P = .019), high BMI (>40 kg/m2; P = .020), low Braden score (<12; P = .018), and low-dose vasopressor therapy (P = .020). Taping endotracheal tubes (ETTs) caused significantly fewer facial PIs than commercial ETT holders (P < .0001). Maximum prone duration/session was significant risk factor for anterior PIs (P = .016), which dropped 71% with newer pressure redistribution products. D-Dimer over 3,200 ug/mL (P = .042) was a significant risk factor for sacrococcygeal PIs while supine. The mortality was 34%; significant risk factors included age over 60 years (P = .005), Sequential Organ Failure Assessment score over 11 (P = .003), and comorbid congestive heart failure (P = .016). CONCLUSIONS: This study illustrates extrinsic and intrinsic risk factors for PIs. Taping the ETT versus using a commercial ETT holder, limiting the maximum duration of prone positioning to less than 32 hours, and frequent repositioning while supine may reduce the number of modifiable risk factors for PIs. Standardized methods for testing the effectiveness of pressure redistribution products for PI prevention will inform product selection and individualized patient care.

12.
J Agric Food Chem ; 69(23): 6720-6732, 2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34081859

RESUMO

This study aimed to confirm the effects of Tibet kefir milk (TKM) on gut microbiota and metabolism. An obesity model was established by feeding a high-fat diet (HFD) to human-microbiota-associated rats. Next-generation sequencing and ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry were applied for gut microbiota and untargeted metabolomics, respectively. After 8 weeks of feeding, the enterotype in the HFD group was switched from ET1 (Prevotella/Akkermansia-dominant) to ET2 (Bacteroides/Akkermansia-dominant). Branched-chain amino-acids- and aromatic amino-acids-metabolism increased, and taurine-conjugated bile acids decreased in the HFD group. Compared with the HFD group, taurocholic acid increased in the TKM1 group, while l-threonine decreased, and equol, taurochenodeoxycholate, and taurodeoxycholic acid increased in the TKM2 group. The metabolite alteration suggested restorative bile acid metabolism, modified metabolic pattern of amino acids, and elevation of anti-obesity factors in the TKM-intervened animals. It can be deduced that changes by TKM intervention in the host gut metabolites are the major contributors to reducing fat deposition.


Assuntos
Kefir , Microbiota , Aminoácidos , Animais , Ácidos e Sais Biliares , Dieta Hiperlipídica/efeitos adversos , Equol , Humanos , Leite , Ratos , Tibet
13.
Materials (Basel) ; 14(11)2021 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-34070819

RESUMO

We studied the effect of CrC interlayers with different carbon contents on the adhesion of CrC/a-C:H coatings prepared by anode assisted reactive magnetron sputtering combined with DC-pulsed plasma enhanced chemical vapor deposition. The adhesion of the coating was measured by indentation and scratching. The coatings were characterized by Raman, XPS, SEM and Nanoindentation. The adhesion of the CrC/a-C:H coating is best when the carbon content in the interlayer of CrC is 44.5%, the scratch adhesion is 74 N, and the indentation adhesion is HF1. In this case, the elastic modulus of the interlayer CrC (284 GPa) is closest to that of the a-C:H layer (274 GPa). In conclusion, when there is no graphitization in the CrC interlayer, and the elastic modulus of the CrC interlayer is close to that of the a-C:H layer, the CrC/a-C:H coatings show the best adhesion.

14.
J Cell Biol ; 220(5)2021 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-33844824

RESUMO

Cargo sorting and the subsequent membrane carrier formation require a properly organized endosomal actin network. To better understand the actin dynamics during endocytic recycling, we performed a genetic screen in C. elegans and identified RTKN-1/Rhotekin as a requisite to sustain endosome-associated actin integrity. Loss of RTKN-1 led to a prominent decrease in actin structures and basolateral recycling defects. Furthermore, we showed that the presence of RTKN-1 thwarts the actin disassembly competence of UNC-60A/cofilin. Consistently, in RTKN-1-deficient cells, UNC-60A knockdown replenished actin structures and alleviated the recycling defects. Notably, an intramolecular interaction within RTKN-1 could mediate the formation of oligomers. Overexpression of an RTKN-1 mutant form that lacks self-binding capacity failed to restore actin structures and recycling flow in rtkn-1 mutants. Finally, we demonstrated that SDPN-1/Syndapin acts to direct the recycling endosomal dwelling of RTKN-1 and promotes actin integrity there. Taken together, these findings consolidated the role of SDPN-1 in organizing the endosomal actin network architecture and introduced RTKN-1 as a novel regulatory protein involved in this process.


Assuntos
Actinas/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Endocitose/fisiologia , Endossomos/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Citoesqueleto de Actina/metabolismo , Fatores de Despolimerização de Actina/metabolismo , Animais , Caenorhabditis elegans/fisiologia , Movimento Celular/fisiologia , Endossomos/fisiologia , Transporte Proteico/fisiologia
15.
AACN Adv Crit Care ; 32(2): 159-168, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33878151

RESUMO

OBJECTIVE: As intensive care unit bed capacity doubled because of COVID-19 cases, nursing leaders created a prone team to support labor-intensive prone positioning of patients with COVID-related acute respiratory distress syndrome. The goal of the prone team was to reduce workload on intensive care teams, standardize the proning process, mitigate pressure injuries and turning-related adverse events, and ensure prone team safety. METHODS: Staff were trained using a hybrid learning model focused on prone-positioning techniques, pressure injury prevention, and turning-related adverse events. RESULTS: No adverse events occurred to patients or members of the prone team. The prone team mitigated pressure injuries using prevention strategies. The prone team and intensive care unit staff were highly satisfied with their experience. CONCLUSION: The prone team provided support for critically ill patients, and team members reported feeling supported and empowered. Intensive care unit staff were highly satisfied with the prone team.


Assuntos
COVID-19/psicologia , COVID-19/terapia , Cuidados Críticos/normas , Pessoal de Saúde/psicologia , Posicionamento do Paciente/normas , Decúbito Ventral , Síndrome do Desconforto Respiratório/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , COVID-19/epidemiologia , Cuidados Críticos/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Posicionamento do Paciente/psicologia , Guias de Prática Clínica como Assunto , SARS-CoV-2 , Estados Unidos/epidemiologia
16.
J Biophotonics ; 14(6): e202100015, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33710798

RESUMO

Imaging sebaceous glands and evaluating morphometric parameters are important for diagnosis and treatment of serum problems. In this article, we investigate the feasibility of high-resolution optical coherence tomography (OCT) in combination with deep learning assisted automatic identification for these purposes. Specifically, with a spatial resolution of 2.3 µm × 6.2 µm (axial × lateral, in air), OCT is capable of clearly differentiating sebaceous gland from other skin structures and resolving the sebocyte layer. In order to achieve efficient and timely imaging analysis, a deep learning approach built upon ResNet18 is developed to automatically classify OCT images (with/without sebaceous gland), with a classification accuracy of 97.9%. Based on the result of automatic identification, we further demonstrate the possibility to measure gland size, sebocyte layer thickness and gland density.


Assuntos
Aprendizado Profundo , Tomografia de Coerência Óptica , Processamento de Imagem Assistida por Computador , Glândulas Sebáceas
17.
Biosens Bioelectron ; 171: 112701, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33096433

RESUMO

With increasing concerns related to the abuse of antibiotics in livestock production worldwide, simple and rapid screening methods for monitoring antibiotics in animal-derived foods are highly desirable. In this study, we propose a facile synthesis strategy for gold nanoclusters (AuNCs) exhibiting remarkable optical properties by employing ovalbumin (OVA) as the template. The OVA-stabilized AuNCs (AuNCs@OVA) manifest intriguing multicolour fluorescence and a gradually declining fluorescence intensity at 650 nm with an increasing concentration of tetracycline family antibiotics (TCs) including tetracycline, chlorotetracycline, oxytetracycline, and doxycycline, which are a widely used class of antibiotics for treating infections in food-producing animals. This performance makes AuNCs@OVA particularly attractive as a broad-spectrum detector for TCs sensing, and we demonstrate that this simple sensing procedure can be realized in real time by directly mixing the target sample and AuNCs@OVA components. Based on this sensing strategy, a microfluidic lab-on-a-chip platform was constructed for the ultrarapid detection of TCs within 30 s. The detection limit was determined to be 0.09 µg/mL in chicken muscle extract, with the recovery ranging from 86.20% to 93.57% in spiked samples. This work provides not only a broad-spectrum sensing strategy for TCs but also a pump-free microfluidic chip with the advantages of being portable, ultrarapid, and low cost, offering a viable alternative for on-the-spot ultrarapid screening of TCs.


Assuntos
Antibacterianos , Técnicas Biossensoriais , Nanopartículas Metálicas , Ovalbumina , Tetraciclinas , Animais , Antibacterianos/análise , Ouro , Microfluídica , Espectrometria de Fluorescência , Tetraciclinas/análise
18.
Skin Res Technol ; 27(4): 479-485, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33141994

RESUMO

BACKGROUND: Basal cell carcinoma, seborrheic keratosis, and nevus are common skin conditions. Though most of the skin diseases can be distinguished from each other by physician's naked eyes, the diagnostic accuracy is not 100%. The accurate diagnosis and assessment of three diseases make a big difference on the clinical management. Nowadays, biopsy is still the gold standard for diagnosis even it is invasive, time-consuming, and painful. Ultrahigh-resolution optical coherence tomography is an emerging technology that can produce in situ, cellular-resolution, real-time, continuous, 3D images in a noninvasive way. MATERIALS AND METHODS: In our study, four basal cell carcinoma patients, five seborrheic keratosis patients, and 10 nevus patients who were diagnosed by histology were studied by ultrahigh-resolution optical coherence tomography after visual examination by experienced dermatologists. Cellular contrast was utilized to clearly identify the features of the three skin diseases. RESULTS: The features including such as hyperkeratosis (horn pseudocysts), papillomatosis, intraepidermal nests, elongated, and expanded rete ridge can be visualized in seborrheic keratosis. Tumor nodular, mucin surrounding with tumor (retraction space in histopathology), tumor subtype, and necrosis were featured in basal cell carcinoma. Pigment was characterized in epidermis and dermis. The comparison of ultrahigh-resolution optical coherence tomography images reveals a strong correlation with histological images. CONCLUSION: Ultrahigh-resolution optical coherence tomography can complement existing diagnostic techniques for investigating seborrheic keratosis, basal cell carcinoma and nevus, and show enormous potential in vivo applications for the three skin diseases in the future.


Assuntos
Carcinoma Basocelular , Ceratose Seborreica , Nevo , Neoplasias Cutâneas , Carcinoma Basocelular/diagnóstico por imagem , Humanos , Ceratose Seborreica/diagnóstico por imagem , Neoplasias Cutâneas/diagnóstico por imagem , Tomografia de Coerência Óptica
19.
Bull Environ Contam Toxicol ; 107(2): 215-220, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32472212

RESUMO

The abuse of antibiotics, such as the cephalosporins in livestock and aquaculture productions, usually causes the widespread antibiotic resistance due to their growth-promoting effects. In this study, cephalexin was chosen as the hapten molecule to prepare a broad-spectrum rabbit polyclonal antibody for cephalosporin antibiotics. The obtained antibody exhibited broad cross-reactivity ranging from 0.05% to 100% with 10 cephalosporins. Based on this antibody, we developed a broad-specific indirect competitive ELISA (ic-ELISA) for cefalexin, cefradine, cefadroxil and cefazolin with the half maximal inhibitory concentration (IC50) ranging from 0.72 to 2.99 ng/mL in working buffer. For animal-derived food samples with spiked cephalosporins, the ic-ELISA exhibited an excellent recovery ranging from 72.3% to 95.6%. To verify the accuracy of this proposed ic-ELISA, its detection performance was evaluated utilizing the high-performance liquid chromatography with satisfactory results. This study confirmed that: firstly, the prepared antibody can be used as a class-specific recognition element to develop immunoassays for cephalosporin antibiotics; and secondly, the developed ic-ELISA provided a new tool for broad-spectrum detection of first-generation cephalosporins in animal-derived foods.


Assuntos
Antibacterianos , Cefalosporinas , Ração Animal , Animais , Cromatografia Líquida de Alta Pressão , Ensaio de Imunoadsorção Enzimática , Coelhos
20.
Polymers (Basel) ; 12(12)2020 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-33348889

RESUMO

In this work, the interactions between bottlebrush polymers and phospholipid membranes were investigated using dissipative particle dynamics simulations. The weak and strong adsorption phenomena between the polymers and membranes were examined by calculating the system parameters. A spring model was introduced to explain the variances in the shape factors and the radius of gyration of the bottlebrush polymers, as well as the order parameters of the phospholipid membrane in the pulling processes. This work provides further understanding for the application of bottlebrush polymers in biological processes.

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