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1.
Waste Manag ; 181: 89-100, 2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38598883

RESUMEN

High-salt content in food waste (FW) affects its resource utilization during biotransformation. In this study, adaptive laboratory evolution (ALE), gene editing, and artificial consortia were performed out to improve the salt-tolerance of Bacillus amyloliquefaciens for producing lipopeptide under FW and seawater. High-salt stress significantly decreased lipopeptide production in the B. amyloliquefaciens HM618 and ALE strains. The total lipopeptide production in the recombinant B. amyloliquefaciens HM-4KSMSO after overexpressing the ion transportor gene ktrA and proline transporter gene opuE and replacing the promoter of gene mrp was 1.34 times higher than that in the strain HM618 in medium containing 30 g/L NaCl. Lipopeptide production under salt-tolerant consortia containing two strains (HM-4KSMSO and Corynebacterium glutamicum) and three-strains (HM-4KSMSO, salt-tolerant C. glutamicum, and Yarrowia lipolytica) was 1.81- and 2.28-fold higher than that under pure culture in a medium containing FW or both FW and seawater, respectively. These findings provide a new strategy for using high-salt FW and seawater to produce value-added chemicals.


Asunto(s)
Bacillus amyloliquefaciens , Lipopéptidos , Bacillus amyloliquefaciens/metabolismo , Bacillus amyloliquefaciens/genética , Lipopéptidos/metabolismo , Tolerancia a la Sal , Agua de Mar/microbiología , Alimentos , Alimento Perdido y Desperdiciado
2.
Artículo en Inglés | MEDLINE | ID: mdl-38652228

RESUMEN

Although fengycin exhibits broad-spectrum antifungal properties, its application is hindered due to its low biosynthesis level and the co-existence of iturin A and surfactin in Bacillus amyloliquefaciens HM618, a probiotic strain. In this study, transcriptome analysis and gene editing were used to explore the potential mechanisms regulating fengycin production in B. amyloliquefaciens. The fengycin level of B. amyloliquefacien HM-3 (∆itu-ΔsrfAA) was 88.41 mg/L after simultaneously inhibiting the biosyntheses of iturin A and surfactin. The knockout of gene eps associated with biofilm formation significantly increased the fengycin level of the strain HM618, whereas the fengycin level decreased 32.05% after knocking out sinI, a regulator of biofilm formation. Transcriptome analysis revealed that the differentially expressed genes, involved in pathways of amino acid and fatty acid syntheses, were significantly down-regulated in the recombinant strains, which is likely associated with a decrease of fengycin production. The knockout of gene comQXPA and subsequent transcriptome analysis revealed that the ComQXPA quorum sensing system played a positive regulatory role in fengycin production. Through targeted genetic modifications and fermentation optimization, the fengycin production of the engineered strain HM-12 (∆itu-ΔsrfAA-ΔyvbJ) in a 5-L fermenter reached 1.172 g/L, a 12.26-fold increase compared to the fengycin level in the strain HM-3 (∆itu-ΔsrfAA) in the Erlenmeyer flask. Taken together, these results reveal the underlying metabolic mechanisms associated with fengycin synthesis and provide a potential strategy for improving fengycin production in B. amyloliquefaciens.

3.
Sci Adv ; 10(14): eadk5229, 2024 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-38569034

RESUMEN

The origin of the cosmic magnetic field remains an unsolved mystery, relying not only on specific dynamo processes but also on the seed field to be amplified. Recently, the diffuse radio emission and Faraday rotation observations reveal that there has been a microgauss-level magnetic field in intracluster medium in the early universe, which places strong constraints on the strength of the initial field and implies the underlying kinetic effects; the commonly believed Biermann battery can only provide extremely weak seed of 10-21 G. Here, we present evidence for the spontaneous Weibel-type magnetogenesis in laser-produced weakly collisional plasma with the three-dimensional synchronous proton radiography, where the distribution anisotropy directly arises from the temperature gradient, even without the commonly considered interpenetrating plasmas or shear flows. This field can achieve sufficient strength and is sensitive to Coulomb collision. Our results demonstrate the importance of kinetics in magnetogenesis in weakly collisional astrophysical scenarios.

4.
Metab Eng ; 83: 123-136, 2024 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-38582143

RESUMEN

Polymyxin is a lipopeptide antibiotic that is effective against multidrug-resistant Gram-negative bacteria. However, its clinical development is limited due to low titer and the presence of homologs. To address this, the polymyxin gene cluster was integrated into Bacillus subtilis, and sfp from Paenibacillus polymyxa was expressed heterologously, enabling recombinant B. subtilis to synthesize polymyxin B. Regulating NRPS domain inhibited formation of polymyxin B2 and B3. The production of polymyxin B increased to 329.7 mg/L by replacing the native promoters of pmxA, pmxB, and pmxE with PfusA, C2up, and PfusA, respectively. Further enhancement in this production, up to 616.1 mg/L, was achieved by improving the synthesis ability of 6-methyloctanoic acid compared to the original strain expressing polymyxin heterologously. Additionally, incorporating an anikasin-derived domain into the hybrid nonribosomal peptide synthase of polymyxin increased the B1 ratio in polymyxin B from 57.5% to 62.2%. Through optimization of peptone supply in the fermentation medium and fermentation in a 5.0-L bioreactor, the final polymyxin B titer reached 962.1 mg/L, with a yield of 19.24 mg/g maltodextrin and a productivity of 10.02 mg/(L·h). This study demonstrates a successful approach for enhancing polymyxin B production and increasing the B1 ratio through combinatorial metabolic engineering.

5.
J Agric Food Chem ; 72(12): 6155-6166, 2024 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-38498691

RESUMEN

The migration and transformation of allelochemicals are important topics in the exploration of allelopathy. Current research on the migration of allelochemicals mostly uses soil column and thin layer methods and verifies it by sowing plant seeds. However, traditional methods inevitably ignore the flux caused by the movement of allelochemicals carried by water. In fact, the flux determines the amount of allelochemicals that directly affect plants. In this work, a method of microdialysis combined with a soil column and UPLC-MS/MS to detect the flux of allelochemicals was developed for the first time and successfully applied to the detection of five taxane allelochemicals in soil. Meanwhile, by adding taxane allelochemicals to the soil and detecting their transformation products using UPLC-MS/MS, the half-life of taxane in the soil was determined, and the transformation pathway of taxane allelochemicals in the soil was further speculated.


Asunto(s)
Feromonas , Suelo , Feromonas/metabolismo , Cromatografía Liquida , Espectrometría de Masas en Tándem , Plantas/metabolismo
6.
Anal Chim Acta ; 1299: 342420, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38499416

RESUMEN

BACKGROUND: Telomerase is considered a biomarker for the early diagnosis and clinical treatment of cancer. The rapid and sensitive detection of telomerase activity is crucial to biological research, clinical diagnosis, and drug development. However, the main obstacles facing the current telomerase activity assay are the cumbersome and time-consuming procedure, the easy degradation of the telomerase RNA template and the need for additional proteases. Therefore, it is necessary to construct a new method for the detection of telomerase activity with easy steps, efficient reaction and strong anti-interference ability. RESULTS: Herein, an efficient, enzyme-free, economical, sensitive, fluorometric detection method for telomerase activity in one-step, named triggered-DNA (T-DNA) nanomachine, was created based on target-triggered DNAzyme-cleavage activity and catalytic molecular beacon (CMB). Telomerase served as a switch and extended few numbers of (TTAGGG)n repeat sequences to initiate the signal amplification in the T-DNA nanomachine, resulting in a strong fluorescent signal. The reaction was a one-step method with a shortened time of 1 h and a constant temperature of 37 °C, without the addition of any protease. It also sensitively distinguished telomerase activity in various cell lines. The T-DNA nanomachine offered a detection limit of 12 HeLa cells µL-1, 9 SK-Hep-1 cells µL-1 and 3 HuH-7 cells µL-1 with a linear correlation detection range of 0.39 × 102-6.25 × 102 HeLa cells µL-1 for telomerase activity. SIGNIFICANCE: In conclusion, our study demonstrated that the triggered-DNA nanomachine fulfills the requirements for rapid detection of telomerase activity in one-step under isothermal and enzyme-free conditions with excellent specificity, and its simple and stable structure makes it ideal for complex systems. These findings indicated the application prospect of DNA nanomachines in clinical diagnostics and provided new insights into the field of DNA nanomachine-based bioanalysis.


Asunto(s)
Técnicas Biosensibles , ADN Catalítico , Telomerasa , Humanos , Células HeLa , Telomerasa/análisis , ADN/química , ADN Catalítico/química , Técnicas Biosensibles/métodos , Límite de Detección
7.
Cell Res ; 34(4): 309-322, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38332200

RESUMEN

Synthetic biology confers new functions to hosts by introducing exogenous genetic elements, yet rebuilding complex traits that are based on large-scale genetic information remains challenging. Here, we developed a CRISPR/Cas9-mediated haploidization method that bypasses the natural process of meiosis. Based on the programmed haploidization in yeast, we further developed an easy-to-use method designated HAnDy (Haploidization-based DNA Assembly and Delivery in yeast) that enables efficient assembly and delivery of large DNA, with no need for any fussy in vitro manipulations. Using HAnDy, a de novo designed 1.024 Mb synthetic accessory chromosome (synAC) encoding 542 exogenous genes was parallelly assembled and then directly transferred to six phylogenetically diverse yeasts. The synAC significantly promotes hosts' adaptations and increases the scope of the metabolic network, which allows the emergence of valuable compounds. Our approach should facilitate the assembly and delivery of large-scale DNA for expanding and deciphering complex biological functions.


Asunto(s)
Cromosomas , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , ADN/metabolismo , Sistemas CRISPR-Cas/genética
8.
Phys Rev E ; 109(1-2): 015204, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38366402

RESUMEN

Shot-to-shot electron beam pointing instability in the plasma bubble, defined here as electron beam pointing jitter (EBJ), is a long-standing problem that limits the potential of the laser wakefield accelerator (LWFA) in a range of demanding applications. In general, EBJ is caused by variations in laser and plasma parameters from shot to shot, although the exact physical mechanism by which EBJ grows in the plasma wave remains unclear. In this work we theoretically investigate the fundamental physics of EBJ inside the plasma bubble and show how the intrinsic betatron oscillation can act as an amplifier to enhance EBJ growth. The analytical formulas for electron trajectory, pointing angle, and EBJ are derived from the basic momentum equation of an electron and verified numerically. It is shown that the shot-to-shot fluctuations of the laser and plasma parameters, such as laser strength, focus, and carrier-envelope phase, as well as the ambient plasma density and profile, lead to EBJ. The evolution of EBJ is dictated by the dynamics of the plasma bubble. Two amplification processes of the betatron oscillation are found in the rapidly evolving bubbles and play important roles in EBJ growth. The first is driven by a linear resonance in the wobbling bubble due to the coupling of the betatron oscillation and the bubble centroid oscillation. The second is a parametric resonance seen in the breathing bubble, where EBJ grows exponentially due to the strong frequency modulation of the betatron oscillation. Their characteristic functions, growth rates, and resonance conditions are deduced analytically and validated numerically. Finally, we also studied how radiation reaction affects EBJ. Our research provides a clear understanding of the basics of EBJ dynamics in LWFA and will help improve the use of LWFA in demanding applications.

9.
J Agric Food Chem ; 72(2): 1203-1212, 2024 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-38179953

RESUMEN

Organofluorine compounds have attracted substantial attention owing to their wide application in agrochemistry. Fluorinase (FlA) is a unique enzyme in nature that can incorporate fluorine into an organic molecule. Chlorinase (SalL) has a similar mechanism as fluorinase and can use chloride but not fluoride as a substrate to generate 5'-chloro-deoxyadenosine (5'-ClDA) from S-adenosyl-l-methionine (SAM). Therefore, identifying the features that lead to this selectivity for halide ions is highly important. Here, we engineered SalL to gain the function of FlA. We found that residue Tyr70 plays a key role in this conversion through alanine scanning. Site-saturation mutagenesis experiments demonstrated that Y70A/C/S/T/G all exhibited obvious fluorinase activity. The G131S mutant of SalL, in which the previously thought crucial residue Ser158 for fluoride binding in FlA was introduced, did not exhibit fluorination activity. Compared with the Y70T single mutant, the double mutant Y70T/W129F increased 5'-fluoro-5-deoxyadenosine (5'-FDA) production by 76%. The quantum mechanics (QM)/molecular mechanics (MM) calculations suggested that the lower energy barriers and shorter nucleophilic distance from F- to SAM in the mutants than in the SalL wild-type may contribute to the activity. Therefore, our study not only renders SalL the activity of FlA but also sheds light on the enzyme selectivity between fluoride versus chloride.


Asunto(s)
Cloruros , Fluoruros , Fluoruros/química , Oxidorreductasas/metabolismo , Proteínas Bacterianas/metabolismo , Desoxiadenosinas , S-Adenosilmetionina/metabolismo
10.
Sci Total Environ ; 914: 169803, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38181949

RESUMEN

The wild yak (Bos mutus) is a cold-tolerant herbivore native to the Tibetan Plateau and has been categorized as vulnerable by the International Union for Conservation of Nature and Natural Resources. Low population densities within currently fragmented habitats and unclear landscape conservation priorities warrant attention. Herein, we employed the maximum entropy (MaxEnt) model using over 900 wild yak occurrence records to model wild yak habitat suitability. Our analysis revealed unprotected wild yak landscapes covering 30.79 % of the habitat area, indicating a conservation gap between protected areas (PAs) and wild yak habitats. To protect metapopulation dynamics and mitigate high risks of poaching, habitat degradation and fragmentation, resource competition, and degenerated genetic characterization of wild yaks in fragmented and degraded habitat, we identified eight habitat patches as landscape conservation units (LCUs) and 14 linkages among the LCUs, enhancing the connectivity between LCUs to decrease negative effects of genetic threats. A centrality analysis demonstrated that Changtang, Arjinshan, and Hoh Xil national nature reserves and their linkages are all critical for the maintenance of habitat connectivity. Here, we suggest that habitat- and LCU-specific conservation strategies should be highlighted during the establishment of PAs and transboundary cooperation. Ultimately, our results can assist conservationists and land managers in comprehending wild yak distribution, movement, and habitat requirements, as well as for the development of effective protection strategies. Furthermore, the combined modeling method (MaxEnt-Zonation-InVEST) could be utilized as a component for identifying conservation priorities and linkages between core patches for species and assessing the efficiency of PAs, core habitats, and corridors in achieving conservation goals. Our study can provide a framework in identifying priority conservation and connectivity between habitat patches to facilitate effectively conservation and genetic resilience for endangered species in fragmented habitats.


Asunto(s)
Conservación de los Recursos Naturales , Ecosistema , Animales , Bovinos , Tibet , China , Especies en Peligro de Extinción
11.
Biosens Bioelectron ; 246: 115869, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38039736

RESUMEN

DNA nanotechnology, developing rapidly in recent years, has unprecedented superiorities in biological application-oriented research including high programmability, convenient functionalization, reconfigurable structure, and intrinsic biocompatibility. However, the susceptibility to nucleases in the physiological environment has been an obstacle to applying DNA nanostructures in biological science research. In this study, a new DNA self-assembly strategy, mediated by double-protonated small molecules instead of classical metal ions, is developed to enhance the nuclease resistance of DNA nanostructures while retaining their integrality and functionality, and the relative application has been launched in the detection of microRNAs (miRNAs). Faced with low-abundance miRNAs, we integrate hybrid chain reaction (HCR) with DNA self-assembly in the presence of double-protonated small molecules to construct a chemiluminescence detection platform with nuclease resistance, which utilizes the significant difference of molecular weight between DNA arrays and false-positive products to effectively separate of reaction products and remove the detection background. This strategy attaches importance to the nucleic acid stability during the assay process via improving nuclease resistance while rendering the detection results for miRNAs more authentic and reliable, opening our eyes to more possibilities for the multiple applications of customized DNA nanostructures in biology, including bioassay, bioimaging, drug delivery, and cell modulation.


Asunto(s)
Técnicas Biosensibles , MicroARNs , Nanoestructuras , MicroARNs/genética , Técnicas Biosensibles/métodos , ADN/genética , ADN/química , Nanoestructuras/química , Nanotecnología/métodos
12.
Eur Radiol Exp ; 7(1): 74, 2023 11 29.
Artículo en Inglés | MEDLINE | ID: mdl-38019353

RESUMEN

BACKGROUND: We tested the hypothesis that radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) promotes tumor cell release and explored a method for reducing these effects. METHODS: A green fluorescent protein-transfected orthotopic HCC model was established in 99 nude mice. In vivo flow cytometry was used to monitor circulating tumor cell (CTC) dynamics. Pulmonary fluorescence imaging and pathology were performed to investigate lung metastases. First, the kinetics of CTCs during the periablation period and the survival rate of CTCs released during RFA were investigated. Next, mice were allocated to controls, sham ablation, or RFA with/without hepatic vessel blocking (ligation of the portal triads) for evaluating the postablation CTC level, lung metastases, and survival over time. Moreover, the kinetics of CTCs, lung metastases, and mice survival were evaluated for RFA with/without ethanol injection. Pathological changes in tumors and surrounding parenchyma after ethanol injection were noted. Statistical analysis included t-test, ANOVA, and Kaplan-Meier survival curves. RESULTS: CTC counts were 12.3-fold increased during RFA, and 73.7% of RFA-induced CTCs were viable. Pre-RFA hepatic vessel blocking prevented the increase of peripheral CTCs, reduced the number of lung metastases, and prolonged survival (all p ≤ 0.05). Similarly, pre-RFA ethanol injection remarkably decreased CTC release during RFA and further decreased lung metastases with extended survival (all p ≤ 0.05). Histopathology revealed thrombus formation in blood vessels after ethanol injection, which may clog tumor cell dissemination during RFA. CONCLUSION: RFA induces viable tumor cell dissemination, and pre-RFA ethanol injection may provide a prophylactic strategy to reduce this underestimated effect. RELEVANCE STATEMENT: RFA for HCC promotes viable tumor cell release during ablation, while ethanol injection can prevent RFA induced tumor cell release. KEY POINTS: • RFA induced the release of viable tumor cells during the ablation procedure in an animal model. • Hepatic vessel blocking can suppress tumor cells dissemination during RFA. • Ethanol injection can prevent RFA-induced tumor cell release, presumably because of the formation of thrombosis.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Neoplasias Pulmonares , Animales , Ratones , Carcinoma Hepatocelular/cirugía , Ratones Desnudos , Neoplasias Hepáticas/cirugía , Modelos Animales de Enfermedad , Etanol
13.
Front Mol Biosci ; 10: 1202524, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37795220

RESUMEN

Background: Actin-related protein 2/3 complex subunit 1B (ARPC1B) is reported to be involved in tumorigenesis and progression. However, its role in kidney renal clear cell carcinoma (KIRC), correlation with tumor-infiltrating immune cells, and prognostic significance remain unclear. Methods: Data sets from the TCGA, GTEx, GEPIA, GEO, UALCAN, and CPTAC databases were extracted and analyzed to investigate the expression difference, prognosis, and clinicopathological features of ARPC1B. Single-sample Gene Set Enrichment Analysis (ssGSEA), CIBERSORT, and TISCH2 analysis were used to examine the relationship between ARPC1B expression and tumor immune infiltration in KIRC. The potential function of ARPC1B in KIRC was explored by GO functional annotation and KEGG pathway analysis. The TIDE algorithm was used to predict and analyze the relationship between ARPC1B expression and response to immune checkpoint blockade (ICB). The expression of ARPC1B was further validated by using quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC). Results: The study showed that ARPC1B expression was an independent prognostic factor of KIRC, with high ARPC1B expression being associated with poor overall survival (OS). Enrichment of GO annotation and pathway analysis showed multiple immune-related functional pathways affected by ARPC1B such as regulation of immune effector process, inflammatory response regulation, antigen processing and presentation, asthma, autoimmune thyroid disease, graft versus host disease, intestinal immune network for IgA production, and type I diabetic mellitus. Moreover, ARPC1B expression positively correlated with infiltrating levels of myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs) in KIRC. Importantly, high ARPC1B expression predicted a low response to ICB in KIRC. Conclusion: This study indicates that ARPC1B expression is an independent prognostic biomarker for OS in KIRC patients. High ARPC1B expression is closely associated with MDSCs and Tregs infiltration. These findings suggest that ARPC1B may serve as a biomarker for prognosis and immune infiltration in KIRC, potentially aiding in the development of novel treatment strategies to improve the survival outcomes for KIRC patients.

14.
Mikrochim Acta ; 190(10): 419, 2023 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-37770696

RESUMEN

A kind of hydroxycamptothecin (HCPT) hybrid molecularly imprinted polymer (AT/MA-HMIPs) with high selectivity and hard silicon skeleton was successfully prepared based on double hybrid monomers. The relationship between templates and functional monomers was studied through computer molecular simulation and experiments. Three single-monomer molecularly imprinted polymers were prepared as controls. The Langmuir isotherm and pseudo-second-order kinetic models were found to fit well with the adsorption results. The maximum adsorption capacity was 18.79 mg/g, and equilibrium was reached within 20 min. Moreover, it shows excellent selectivity (imprinting factor is 10.73) and good recoverability (after 10 adsorption-desorption cycles, the adsorption capacity only decreases by 7.75%) for HCPT. The purity of HCPT can reach 80.86% after being put into a solid phase extraction column and used in an actual sample, and the yield was 61.43%. This study lays the fundament for the development of excellent HCPT molecularly imprinted composites.

15.
Nat Commun ; 14(1): 5782, 2023 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-37723172

RESUMEN

In laser-driven inertial confinement fusion, driving pressure boosting and smoothing are major challenges. A proposed hybrid-drive (HD) scheme can offer such ideal HD pressure performing stable implosion and nonstagnation ignition. Here we report that in the hemispherical and planar ablator targets installed in the semicylindrical hohlraum scaled down from the spherical hohlraum of the designed ignition target, under indirect-drive (ID) laser energies of ~43-50 kJ, the peak radiation temperature of 200 ± 6 eV is achieved. And using only direct-drive (DD) laser energies of 3.6-4.0 kJ at an intensity of 1.8 × 1015 W/cm2, in the hemispherical and planar targets the boosted HD pressures reach 3.8-4.0 and 3.5-3.6 times the radiation ablation pressure respectively. In all the above experiments, significant HD pressure smoothing and the important phenomenon of how a symmetric strong HD shock suppresses the asymmetric ID shock pre-compressed fuel are demonstrated. The backscattering and hot-electron energy fractions both of which are about one-third of that in the DD scheme are also measured.

16.
Chem Commun (Camb) ; 59(67): 10153-10156, 2023 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-37530562

RESUMEN

We propose a universal fluorescence method for detection of nucleic acids based on rolling circle amplification (RCA) combined with a magnetic DNA machine and using dengue virus nucleic acids as an example target. RCA specifically amplifies the target and yields a large number of initiators employing heat-labile double-stranded DNase. The magnetic DNA machine produces a fluorescence signal and eliminates background noise. This method achieved a wide linear range, promising recovery and ultrahigh recognition specificity for one-base mismatches, and indicates the potential application of this sensing strategy in the clinical diagnosis of nucleic acids of pathogens.


Asunto(s)
Técnicas Biosensibles , Ácidos Nucleicos , Técnicas de Amplificación de Ácido Nucleico/métodos , ADN/genética , Desoxirribonucleasa I , Técnicas Biosensibles/métodos
17.
Biosensors (Basel) ; 13(7)2023 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-37504112

RESUMEN

A photoelectrochemical (PEC) detection platform was built based on the branched rutile/anatase titanium dioxide (RA-TiO2) electrode. Theoretical calculations proved that the type-II band alignment of rutile and anatase could facilitate charge separation in the electrode. The self-generated electric field at the interface of two phases can enhance the electron transfer efficiency of the electrode. Carboxylated CdTe quantum dots (QDs) were applied as signal amplification factors. Without the target DNA presence, the CdTe QDs were riveted to the surface of the electrode by the hairpin probe DNA. The sensitization of CdTe QDs increased the photocurrent of the electrode significantly. When the target DNA was present, the structural changes of the hairpin probe DNA resulted in the failure of the sensitized structure. Benefiting from excellent electrode structure design and CdTe QDs sensitization strategy, the PEC assays could achieve highly sensitive and specific detection of target DNA in the range of 1 fM to 1 nM, with a detection limit of 0.23 fM. The electrode construction method proposed in this article can open a new avenue for the preparation of more efficient PEC sensing devices.


Asunto(s)
Técnicas Biosensibles , Compuestos de Cadmio , Puntos Cuánticos , Compuestos de Cadmio/química , Electrones , Puntos Cuánticos/química , Telurio/química , ADN/química , Técnicas Biosensibles/métodos , Electrodos , Técnicas Electroquímicas/métodos , Límite de Detección
18.
J Econ Entomol ; 116(4): 1276-1285, 2023 08 10.
Artículo en Inglés | MEDLINE | ID: mdl-37279557

RESUMEN

The whitefly, Bemisia tabaci, is a destructive and invasive pest of many horticultural plants including poinsettia (Euphorbia pulcherrima). Outbreaks of B. tabaci cause serious damage by direct feeding on phloem sap, and spreading 100+ plant viruses to crops. Bemisia tabaci were observed more frequently on green than red poinsettia leaves, and the factors responsible for this are unknown. Here, we investigated the development rate, survivorship, fecundity of B. tabaci feeding on green versus red leaves, as well as the leaves' volatiles, trichome density, anthocyanin content, soluble sugars, and free amino acids. Compared to red leaves, B. tabaci on green leaves showed increased fecundity, a higher female sex ratio, and survival rate. The green color alone was more attractive to B. tabaci than red. Red leaves of poinsettia contained more phenol, and panaginsene in their volatiles. Alpha-copaene and caryophyllene were more abundant in the volatiles of poinsettia green leaves. Leaf trichome density, soluble sugars and free amino acids were higher in green than red leaves of poinsettia, anthocyanin was lower in green than red leaves. Overall, green leaves of poinsettia were more susceptible and attractive to B. tabaci. The morphological and chemical variation between red and green leaves also differed; further investigation may reveal how these traits affect B. tabaci's responses.


Asunto(s)
Euphorbia , Hemípteros , Animales , Aminoácidos/análisis , Antocianinas/análisis , Hojas de la Planta/química , Tricomas , Masculino , Femenino
19.
Biochem Biophys Res Commun ; 671: 192-199, 2023 09 03.
Artículo en Inglés | MEDLINE | ID: mdl-37302294

RESUMEN

The therapeutic effects and application of radiotherapy are restricted to some extent due to low radiosensitivity of tumor tissues and adverse effects by excess dosage. Current radiosensitizers are confronted with problems in clinical translation because of complicated manufacture technique and high cost. In this research, we have synthesized a radiosensitizer with advantages in low cost and mass production, which could be applied to CT imaging and enhanced radiotherapy in breast cancer, namely Bi-DTPA. It not only enhanced tumor CT imaging which resulted in better therapeutic accuracy, but also realized radiotherapy sensitization by producing massive ROS and inhibit tumor proliferation, providing a sound perspective in the clinical translation of the radiosensitizer.


Asunto(s)
Neoplasias , Fármacos Sensibilizantes a Radiaciones , Humanos , Fármacos Sensibilizantes a Radiaciones/farmacología , Fármacos Sensibilizantes a Radiaciones/uso terapéutico , Tolerancia a Radiación , Neoplasias/tratamiento farmacológico , Ácido Pentético/farmacología , Ácido Pentético/uso terapéutico , Tomografía Computarizada por Rayos X/métodos
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