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The use of non-solvating, or as-called sparingly-solvating, electrolytes (NSEs), is regarded as one of the most promising solutions to the obstacles to the practical applications of Li-S batteries. However, it remains a puzzle that long-life Li-S batteries have rarely, if not never, been reported with NSEs, despite their good compatibility with Li anode. Here, we find the capacity decay of Li-S batteries in NSEs is mainly due to the accumulation of the dead Li2 S at the cathode side, rather than the degradation of the anodes or electrolytes. Based on this understanding, we propose an electrochemical strategy to reactivate the accumulated Li2 S and revive the dead Li-S batteries in NSEs. With such a facile approach, Li-S batteries with significantly improved cycling stability and accelerated dynamics are achieved with diglyme-, acetonitrile- and 1,2-dimethoxyethane-based NSEs. Our finding may rebuild the confidence in exploiting non-solvating Li-S batteries with practical competitiveness.
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Mutations in K-Ras and epidermal growth factor receptor (EGFR) are mutually exclusive, but it is not known how K-Ras activation inactivates EGFR, leading to resistance of cancer cells to anti-EGFR therapy. Here, we report that the K-Ras effector p38γ MAPK confers intrinsic resistance to small molecular tyrosine kinase inhibitors (TKIs) by concurrently stimulating EGFR gene transcription and protein dephosphorylation. We found that p38γ increases EGFR transcription by c-Jun-mediated promoter binding and stimulates EGFR dephosphorylation via activation of protein-tyrosine phosphatase H1 (PTPH1). Silencing the p38γ/c-Jun/PTPH1 signaling network increased sensitivities to TKIs in K-Ras mutant cells in which EGFR knockdown inhibited growth. Similar results were obtained with the p38γ-specific pharmacological inhibitor pirfenidone. These results indicate that in K-Ras mutant cancers, EGFR activity is regulated by the p38γ/c-Jun/PTPH1 signaling network, whose disruption may be a novel strategy to restore the sensitivity to TKIs.
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Receptores ErbB/genética , Receptores ErbB/metabolismo , Proteína Quinasa 12 Activada por Mitógenos/metabolismo , Inhibidores de Proteínas Quinasas/farmacología , Transcripción Genética , Animales , Células Cultivadas , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Mutación , Fosforilación/efectos de los fármacos , Bibliotecas de Moléculas Pequeñas/farmacología , Transcripción Genética/efectos de los fármacosRESUMEN
A novel silica-based stationary phase with branched octadecyl groups was prepared by the sequential employment of the Michael addition reaction and photoinduced thiol-yne click chemistry with 3-aminopropyl-functionalized silica microspheres as the initial material. The resulting stationary phase denoted as SiO2 -N(C18)4 was characterized by elemental analysis, FTIR spectroscopy and Raman spectroscopy, demonstrating the existence of branched octadecyl groups in silica microspheres. The separations of benzene homologous compounds, acid compounds and amine analogues were conducted, demonstrating mixed-mode separation mechanism on SiO2 -N(C18)4 . Baseline separation of basic drugs mixture was acquired with the mobile phase of acetonitrile/H2 O (5%, v/v). SiO2 -N(C18)4 was further applied to separate Corydalis yanhusuo Wang water extracts, and more baseline separation peaks were obtained for SiO2 -N(C18)4 than those on Atlantis dC18 column. It can be expected that this new silica-based stationary phase will exhibit great potential in the analysis of basic compounds.
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Egress is a vital step in the endogenous development of apicomplexan parasites, as it assures the parasites exit from consumed host cells and entry into fresh ones. However, little information has previously been reported on this step of Eimeria spp. In this study, we investigated in vitro egress of Eimeria tenella sporozoites triggered by acetaldehyde. We found that addition of exogenous acetaldehyde induces egress of sporozoites from primary chicken kidney cells (PCKs) and stimulate secretion of E. tenella microneme 2 protein (EtMic 2). Moreover, by using cellular calcium inhibitors, we further proved that these processes were dependent on the intracellular calcium of the parasites. Our findings provide clues to the study of interaction between eimerian parasites and their hosts.
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Calcio/metabolismo , Eimeria tenella/metabolismo , Proteínas Protozoarias/metabolismo , Acetaldehído/farmacología , Animales , Células Cultivadas , Pollos , Eimeria tenella/efectos de los fármacos , Concentración de Iones de Hidrógeno , Riñón/citología , Riñón/efectos de los fármacos , Riñón/parasitología , Esporozoítos/efectos de los fármacos , Esporozoítos/metabolismoRESUMEN
Objective: To investigate the killing effect of hypericin on tachyzoites of Toxoplasma gondii RH strain in vitro. Methods: Normal saline ï¼group Aï¼ and different concentrations of hypericin (5 µg/ml, group B; 50 µg/ml, group C; 500 µg/ml, group Dï¼ were added to T. gondii tachyzoites in 24-well plateï¼1×10(6)/wellï¼. The tachyzoites were harvested after 2, 4 and 6 h, and underwent the following treatment: trypan blue staining to calculate the dyeing rate, Giemsa staining to observe the morphological and structural alterations of tachyzoites, and transmission electron microscopy to observe the ultrastructure of tachyzoites. In addition, flow cytometry was performed to calculate the survival rate of YFP-carrying Toxoplasma with the same treatment. Results: The trypan blue dyeing rate at 2 h after treatment in groups B, C and D wasï¼11.0±3.6ï¼%, ï¼25.0±6.3ï¼% andï¼40.0±2.7ï¼% respectively, with a significant difference of group D versus B and C ï¼P<0.01ï¼, and groups C and D versus group A ï¼»ï¼6.0±3.0ï¼%ï¼ï¼½. The dyeing rate at 4 h and 6 h in group D wasï¼97.0±2.0ï¼% and ï¼98.0±1.7ï¼%, respectively, both significantly higher than that of groups C ï¼»ï¼30.0±7.2ï¼%, ï¼42.7±5.5ï¼%ï¼½, B ï¼»ï¼20.0±3.0ï¼%, ï¼34.0±6.6ï¼%ï¼½ and A ï¼»ï¼10.0±1.0ï¼%, ï¼19.3±4.9ï¼%ï¼½ï¼P<0.01ï¼. Giemsa staining showed gradual end swelling and necrosis of tachyzoites with increased treatment duration and dosage. Transmission electron microscopy showed swelling of worm body, gap between cell membrane and matrix, increase and enlargement of vacuoles inside worm body, disruption of cell membrane, and dissolving of inner structures, with increased treatment duration. Flow cytometry showed significant difference of tachyzoite survival rate at 2, 4 and 6 h after hypericin treatment with that of the control groupï¼P<0.01ï¼. The survival rate of group C at 2 h after hypericin treatment wasï¼7.9±1.9ï¼%, significantly lower than that of groups B ï¼»ï¼38.1±5.5ï¼%ï¼½ and A ï¼»ï¼81.8±6.0ï¼%ï¼½ ï¼P<0.01ï¼. No tachyzoite was found to survive in group D at 2 h and in group C at 4 h. The survival rate of group B at 4 and 6 h after hypericin treatment wasï¼14.3±7.9ï¼% and ï¼1.4±1.8ï¼%, respectively, both significantly lower than that of group Aï¼»ï¼73.8±11.3ï¼% andï¼64.1±14.4ï¼%, respectivelyï¼½ ï¼P<0.01ï¼. Conclusion: Hypericin has a remarkable killing effect on T. gondii tachyzoites, and the efficacy positively correlates with the dose and treatment duration.
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Toxoplasma , Antracenos , Microscopía Electrónica de Transmisión , Perileno/análogos & derivadosRESUMEN
Egress from host cells is a vital step of the intracellular life cycle of apicomplexan parasites such as Toxoplasma gondii. This phenomenon has attracted attentions from many research groups. Previous studies have shown that ethanol could stimulate the release of microneme proteins by elevating intracellular Ca(2+) concentration of T. gondii, resulting in the parasite egress from host cells. However, little information about egress is known on Eimeria species, the causative agent of coccidiosis in poultry and livestock. In this report, we studied the effect of ethanol and isopropanol on the egress of eimerian parasites. Eimeria tenella sporozoites cultured in primary chicken kidney cells were treated with ethanol and isopropanol, then the egressed parasites were analyzed. Ethanol and isopropanol could induce the rapid egress of E. tenella sporozoites from host cells. No substantial damage was found in parasite-egressed host cells. Compared to the freshly isolated sporozoites, the re-invading ability and reproductivity of the egressed parasites significantly decreased by 43.4 and 44.1 % individually. We also found that fewer sporozoites egressed from host cells when the parasites developed for a longer time before the alcohol treatment. These results demonstrate an in vitro egress mode different from that of T. gondii, facilitating the deciphering of the mechanisms of egress of eimerian parasites.
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2-Propanol/farmacología , Coccidiosis/veterinaria , Eimeria tenella/efectos de los fármacos , Eimeria tenella/fisiología , Etanol/farmacología , Enfermedades de las Aves de Corral/parasitología , Animales , Pollos , Coccidiosis/parasitología , Esporozoítos/efectos de los fármacos , Esporozoítos/fisiologíaRESUMEN
The Vasa gene is a vital germline marker to study the origin and development of germ cells and gonads in many organisms. Until now, little information was available about the characteristics of the Vasa gene in Schistosoma japonicum (S. japonicum). In this study, we cloned the open reading frame (ORF) of the S. japonicum Vasa-like gene (Sj-Vasa). The expression pattern and tissue localization of Sj-Vasa were also analyzed. Our results showed that Sj-Vasa shared the general feature of DEAD-box family member proteins. Sj-Vasa was transcribed and expressed throughout the S. japonicum life cycle with transcription exhibiting high levels at day 24 in both male and female worms, and the expression level in the female was always higher than that in the male. Sj-Vasa protein was localized in a variety of tissues of adult schistosomes, including the gonads (ovary, vitellarium, and testes), the subtegument, and some cells of the parenchyma. To our knowledge, this is the first report of preliminary characterization and expression of the Vasa-like gene that may play an important role in the development of the worm, especially in reproductive organs of S. japonicum.
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Schistosoma japonicum/genética , Animales , Femenino , Regulación del Desarrollo de la Expresión Génica , Proteínas del Helminto/genética , Proteínas del Helminto/metabolismo , Humanos , Masculino , Ovario/metabolismo , Schistosoma japonicum/crecimiento & desarrollo , Schistosoma japonicum/metabolismo , Esquistosomiasis Japónica/parasitología , Testículo/metabolismoRESUMEN
Novel cyclodextrin (CD) chiral stationary phases (CD-CSPs) with well-defined structure have been successfully synthesized by immobilization of mono/di(10-undecenoyl)-perphenylaminocarbonyl ß-CD on the 3-mercaptopropyl functionalized silica gel via thiol-ene click chemistry. The phenyl carbamate groups on the rims of CD extended the cavity of CD-CSPs, which facilitated the formation of inclusion complex with various types of racemic compounds under RP mode, and also improved the π-π stacking interaction, dipole-dipole interaction, and hydrogen bonding interaction with racemic compounds under normal phase mode. Fifteen racemic compounds were successfully separated on this CD-CSP with HPLC, and the chromatographic results also demonstrated that thiol-ene click chemistry affords a facile approach for preparation of CSPs.
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Cromatografía Líquida de Alta Presión/métodos , Química Clic/métodos , beta-Ciclodextrinas/química , beta-Ciclodextrinas/síntesis química , Reproducibilidad de los Resultados , EstereoisomerismoRESUMEN
Facile preparation of core-shell magnetic metal-organic framework nanospheres by a layer-by-layer approach is presented. The nanospheres have high surface area (285.89â cm(2) g(-1)), large pore volume (0.18â cm(3) g(-1)), two kinds of mesopores (2.50 and 4.72â nm), excellent magnetic responsivity (55.65â emu g(-1)), structural stability, and good dispersibility. The combination of porosity, hydrophobicity, and uniform magnetism was exploited for effective enrichment of peptides with simultaneous exclusion of high molecular weight proteins. The nanospheres were successfully applied in the selective enrichment of endogenous peptides in human serum.
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Nanosferas , Péptidos/química , Fenómenos Magnéticos , Fenómenos FísicosRESUMEN
Selective enrichment of glycopeptides from complicated biological samples is critical for glycoproteomics to obtain the structure and glycosylation information of glycoproteins using mass spectrometry (MS), which still remains a great challenge. Hydrophilic interaction chromatography (HILIC)-based strategies have been proposed for selective isolation of glycopeptides via the interactions between the glycan of glycopeptides and the matrices. However, the application of these methods is limited by the medium selectivity of HILIC matrices. In this study, hydrophilic metal-organic frameworks (MOFs) were fabricated and used as a HILIC matrix. The cross-linked CD-MOFs (LCD-MOFs) were facilely prepared with γ-cyclodextrin as ligand and possessed nano-sized cubic structure, superior hydrophilicity, and bio-compatibility. The LCD-MOFs performance for the selective enrichment of glycopeptides from the complex biological samples were investigated with a digested mixture of human immunoglobulin G (IgG) that was used as standard samples. In the selectivity assessment, the non-glycopeptides causing ion suppression to the glycopeptides were effectively removed, the signal of glycopeptides were enhanced significantly by LCD-MOFs, and twenty glycopeptides were identified with 67 fmol of IgG digest. In addition, the resulting LCD-MOFs demonstrated the lower detection limit (3.3 fmol) with a satisfactory recovery yield (84-103%) for glycopeptide enrichment from a digest of IgG. Furthermore, a promising protocol was developed for the selective enrichment of glycopeptides from mouse liver, and 344 unique N-glycosylation sites that mapped to 290 different glycoproteins were identified in a single MS run. The results clearly demonstrated that when used in a HILIC matrix, LCD-MOFs have great potential for identifying and enriching low-abundant glycopeptides in complex biological samples.
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Cromatografía de Afinidad , Glicopéptidos/aislamiento & purificación , Compuestos Organometálicos/química , Animales , Glicopéptidos/análisis , Glicosilación , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Inmunoglobulina G/metabolismo , Hígado/metabolismo , Ratones , Nanoestructuras/química , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , gamma-Ciclodextrinas/químicaRESUMEN
Solid electrolyte interface (SEI) is arguably the most important concern in graphite anodes, which determines their achievable Coulombic efficiency (CE) and cycling stability. In spent graphite anodes, there are already-formed (yet loose and/or broken) SEIs and some residual active lithium, which, if can be inherited in the regenerated electrodes, are highly desired to compensate for the lithium loss due to SEI formation. However, current graphite regenerated approaches easily destroy the thin SEIs and residue active lithium, making their reuse impossible. Herein, this work reports a fast-heating strategy (e.g., 1900 K for ≈150 ms) to upcycle degraded graphite via instantly converting the loose original SEI layer (≈100 nm thick) to a compact and mostly inorganic one (≈10-30 nm thick with a 26X higher Young's Modulus) and still retaining the activity of residual lithium. Thanks to the robust SEI and enclosed active lithium, the regenerated graphite exhibited 104.7% initial CE for half-cell and gifted the full cells with LiFePO4 significantly improved initial CE (98.8% versus 83.2%) and energy density (309.4 versus 281.4 Wh kg-1), as compared with commercial graphite. The as-proposed upcycling strategy turns the "waste" graphite into high-value prelithiated ones, along with significant economic and environmental benefits.
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Using Li2S cathodes instead of S cathodes presents an opportunity to pair them with Li-free anodes (e.g., graphite), thereby circumventing anode-related issues, such as poor reversibility and safety, encountered in Li-S batteries. However, the moisture-sensitive nature of Li2S causes the release of hazardous H2S and the formation of insulative by-products, increasing the manufacturing difficulty and adversely affecting cathode performance. Here, Li4SnS4, a Li+ conductor that is air-stable according to the hard-soft acid-base principle, is formed in situ and uniformly on Li2S particles because Li2S itself participates in Li4SnS4 formation. When exposed to air (20% relative humidity), the protective Li4SnS4 layer maintains its components and structure, thus contributing to the enhanced stability of the Li2S@Li4SnS4 composite. In addition, the Li4SnS4 layer can accelerate the sluggish conversion of Li2S because of its favorable interfacial charge transfer, and continuously confine lithium polysulfides owing to its integrity during electrochemical processes. A graphite-Li2S pouch cell containing a Li2S@Li4SnS4 cathode is constructed, which shows stable cyclability with 97% capacity retention after 100 cycles. Hence, combining a desirable air-stable Li2S cathode and a highly reversible Li-free configuration offers potential practical applications of graphite-Li2S full cells.
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Toxoplasma gondii is an obligate intracellular parasite that can infect any nucleated cells of warm-blood vertebrates. Invasion and egress by this protozoan parasite, both of which are crucial for its life cycle, are rapid events that are dependent upon parasite motility. A variety of chemicals and molecules have been utilized to induce Toxoplasma early egress from host cells. Here, we aimed to determine whether nitric oxide (NO) could induce egress of T. gondii tachyzoites from infected cells. Infected macrophages were collected from C57BL/6 mice and treated with different doses of sodium nitroferricyanide (III) dihydrate (SNP) which releases nitric oxide into cell culture medium. The pattern of parasite egress was analyzed by flow cytometry. The results showed that exogenous NO released by SNP could trigger egress of T. gondii tachyzoites from infected peritoneal macrophages which then underwent necrosis after parasite egress. Our findings provided a novel approach to study the interactions between host immune responses and T. gondii.
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Macrófagos Peritoneales/parasitología , Óxido Nítrico/farmacología , Toxoplasma/efectos de los fármacos , Animales , Apoptosis , Citometría de Flujo , Humanos , Macrófagos Peritoneales/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Óxido Nítrico/metabolismo , Donantes de Óxido Nítrico/farmacología , Nitroprusiato/farmacología , Toxoplasma/fisiologíaRESUMEN
In order to increase the content of mineral admixtures in cement, this study proposes a method for preparing a high-volume mineral admixture cementitious material (HMAC) using superfine cement as a reverse filling material. Firstly, superfine cement is prepared through mechanical grinding. Then, the activity of mineral admixtures (such as slag and fly ash) is enhanced by mechanical grinding, sulfate activation, and alkali activation methods. Meanwhile, the evolution of HMCM from microstructure to macroscopic mechanical behavior is studied by combining a laser particle size analyzer and a scanning electron microscope. Furthermore, the reverse filling mechanism of superfine cement on mineral admixtures under different activation conditions is proposed. Results show that superfine cement can largely improve the utilization rate of cement clinker and the compressive strength of cementitious materials. In the condition that the compressive strength is not lower than that of the control group (without mineral admixture), the content of mineral admixture can be increased to 50%, 70%, and 90% after mechanical grinding, sulfate activation, and alkali activation, respectively. Analysis indicates that the reverse filling effect of superfine cement is the main reason for improving the density of the HMCM.
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In this investigation, non-spontaneous combustion coal gangue was activated by two methods: (1) low-temperature calcination and (2) calcium addition. Differences in the activity of the activated coal gangue were studied at various calcination temperatures and amounts of calcium addition. Meanwhile, the cementation activity of the activated coal gangue was evaluated according to the activity effect analysis. Furthermore, the influences of the activated coal gangue on the cementation activity of cement were investigated. The results indicated that the activities of the activated coal gangue increased at a temperature between 500 °C and 700 °C. The calcium addition method can also increase the activity of coal gangue, with the effect being better when the gangue is mixed with slag. The addition of calcium and the calcination of coal gangue can promote the production of active minerals such as metakaolin, which is the main reason for the increased cementation activity.
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S2--enriched alkali-activator (SEAA) was prepared by modifying the alkali activator through Na2S. The effects of S2--enriched alkali-activated slag (SEAAS) on the solidification performance of Pb and Cd in MSWI fly ash were investigated using SEAAS as the solidification material for MSWI fly ash. Combined with microscopic analysis through scanning electron microscopy (SEM), X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR), the effects of SEAAS on the micro-morphology and molecular composition of MSWI fly ash were studied. The solidification mechanism of Pb and Cd in S2--enriched alkali-activated MSWI fly ash was discussed in detail. The results showed that the solidification performance for Pb and Cd in MSWI fly ash induced by SEAAS was significantly enhanced first and then improved gradually with the increase in dosage of ground granulated blast-furnace slag (GGBS). Under a low GGBS dosage of 25%, SEAAS could eliminate the problem of severely exceeding permitted Pb and Cd in MSWI fly ash, which compensated for the deficiency of alkali-activated slag (AAS) in terms of solidifying Cd in MSWI fly ash. The highly alkaline environment provided by SEAA promoted the massive dissolution of S2- in the solvent, which endowed the SEAAS with a stronger ability to capture Cd. Pb and Cd in MSWI fly ash were efficiently solidified by SEAAS under the synergistic effects of sulfide precipitation and chemical bonding of polymerization products.
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BACKGROUND: Toxoplasma gondii is an opportunistic protozoan that is ubiquitous in humans and animals. It can invade any human organ and cause severe diseases, including toxoplasma ophthalmopathy, meningoencephalitis, and liver necrosis. Porcine toxoplasmosis is prevalent in China. CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) and Cas (CRISPR-Associated Protein) systems are widely used for gene editing and pathogen detection. CRISPR-based diagnostics are molecular assays that have been developed to detect parasites with high sensitivity and specificity. METHODS: This study aimed to establish a combined CRISPR/Cas12a and RPA rapid detection method for T. gondii by targeting the B1 gene and 529 bp repeat element (529 RE). The detection results could be visualized by the fluorescence or lateral flow strips (LFS). The sensitivity and specificity of the method were evaluated, and T. gondii-infected mouse blood was used for detection. RESULTS: The results indicated that the established method for T. gondii detection was satisfactory, with a detection limit of 1.5 cp/µl for the two loci. Moreover, the B1 gene could detect 1 tachyzoite per reaction, and the 529 RE could detect 0.1 tachyzoite per reaction, consistently with the highly sensitive nested polymerase chain reaction (PCR) results. The method was suitable for strains, including RH, and did not cross-react with other protozoa DNA with similar habits. The T. gondii-infected mouse blood samples were all positive for T. gondii at 1, 3, and 5 days post infection (dpi). CONCLUSIONS: This study established a rapid, sensitive, and time-saving DNA detection method for T. gondii that has the potential to be an alternative tool for T. gondii detection in the field.
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Toxoplasma , Toxoplasmosis , Animales , Humanos , Ratones , Porcinos , Sistemas CRISPR-Cas , Toxoplasmosis/parasitología , Toxoplasma/genética , Reacción en Cadena de la Polimerasa , Sensibilidad y Especificidad , ADN Protozoario/análisisRESUMEN
In conventional lithium-ion batteries (LIBs), active lithium (Li) ions, which function as charge carriers and could only be supplied by the Li-containing cathodes, are also consumed during the formation of the solid electrolyte interphase. Such irreversible Li loss reduces the energy density of LIBs and is highly desired to be compensated by prelithiation additives. Herein, lithium selenide (Li2Se), which could be irreversibly converted into selenide (Se) at 2.5-3.8 V and thus supplies additional Li, is proposed as a cathode prelithiation additive for LIBs. Compared with previously reported prelithiation reagents (e.g., Li6CoO4, Li2O, and Li2S), the delithiation of Li2Se not only delivers a high specific capacity but also avoids gas release and incompatibility with carbonate electrolytes. The electrochemical characterizations show that with the addition of 6 wt % Li2Se to the LiFePO4 (LFP) cathodes, a 9% increase in the initial specific capacity in half Li||LFP cells and a 19.8% increase in the energy density (based on the total mass of the two electrodes' materials) could be achieved without sacrificing the other battery performance. This work demonstrates the possibility to use Li2Se as a high-efficiency prelithiation additive for LIBs and provides a solution to the high-energy LIBs.
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It is well known that the physicochemical properties of nanocarriers, which are closely related to the surface modification of nanoparticles, have crucial impacts on their biological effects. Herein, the interaction between functionalized degradable dendritic mesoporous silica nanoparticles (DDMSNs) and bovine serum albumin (BSA) was investigated for probing into the nanocarriers' potential toxicity using multi-spectroscopy such as ultraviolet/visible (UV/Vis), synchronous fluorescence, Raman and circular dichroism (CD) spectroscopy. BSA, owing to its structural homology and high sequence similarity with HSA, was employed as the model protein to study the interactions with DDMSNs, amino-modified DDMSNs (DDMSNs-NH2) and hyaluronic acid (HA) coated nanoparticles (DDMSNs-NH2-HA). It was found that the static quenching behavior of DDMSNs-NH2-HA to BSA was accompanied by an endothermic and hydrophobic force-driven thermodynamic process, which was confirmed by fluorescence quenching spectroscopic studies and thermodynamic analysis. Furthermore, the conformational variations of BSA upon interaction with nanocarriers were observed by combination of UV/Vis, synchronous fluorescence, Raman and CD spectroscopy. The microstructure of amino residues in BSA changed due to the existence of nanoparticles, for example, the amino residues and hydrophobic groups exposed to microenvironment and the alpha helix (α-helix) content of BSA decreased. Specially, through thermodynamic analysis, the diverse binding modes and driving forces between nanoparticles and BSA were discovered because of different surface modifications on DDMSNs, DDMSNs-NH2 and DDMSNs-NH2-HA. We believe that this work can promote the interpretation of mutual impact between nanoparticles and biomolecules, which will be in favor of predicting the biological toxicity of nano-DDS and engineering functionalized nanocarriers.
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Nanopartículas , Albúmina Sérica Bovina , Albúmina Sérica Bovina/química , Dicroismo Circular , Espectrometría de Fluorescencia/métodos , Termodinámica , Unión Proteica , Sitios de Unión , Espectrofotometría Ultravioleta/métodosRESUMEN
Toxoplasma gondii is an obligate parasitic protozoon that transmits to animals and humans via ingested food. Cats that act as T. gondii's final hosts play a critical role in T. gondii transmission by shedding millions of oocysts. Timely diagnosis of infected cats is essential for preventing toxoplasmosis because oocysts are a putative T. gondii source in epidemiology. We developed a new visual LAMP assay targeting the B1 gene to analyze single oocysts in cat feces in this study. The amplification result could be visually estimated based on the color change. LAMP assay analytical sensitivity was 101 copies/µL for the B1 gene plasmid, which was tenfold better than the PCR reaction. There were no cross-reactions with other parasites. The LAMP assay can detect a single T. gondii oocyst in 200 mg of cat feces. The LAMP assay detected a single oocyst in 200 mg cat feces at a higher rate than the PCR assay (83.3% vs. 50.0%).