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1.
J Org Chem ; 88(4): 2288-2295, 2023 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-36738288

RESUMEN

A simple and practical electron donor-acceptor (EDA) strategy to synthesize various 3-alkylated coumarins from easily available coumarins and naturally abundant carboxylic acids under photocatalyst-, oxidant-, and additive-free and mild conditions is reported. Using Na2S as the catalytic electron donor, a series of primary, secondary, and tertiary carbon radicals can be efficiently generated, and the EDA complex can be regenerated without an alkaline additive.

2.
Fish Shellfish Immunol ; 136: 108703, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36948366

RESUMEN

NK-lysin (NKL) is a positively charged antimicrobial peptide with broad-spectrum bactericidal activities. In this study, the cDNA sequence of NKL (TmNKL) from black scraper (Thamnaconus modestus) was cloned, which encodes a predicted polypeptide of 150 amino acids that contains a surfactant protein B domain with three disulfide bonds. Phylogenetically, TmNKL was most closely related to its teleost counterpart from tiger puffer (Takifugu rubripes). Expression analysis demonstrated that TmNKL transcripts were constitutively expressed in all tested tissues, with the highest expression levels in the gills. Its expression was significantly upregulated in the gills, head kidney, and spleen after infection with Vibrio parahaemolyticus. A linear peptide (TmNKLP40L) and a disulfide-type peptide (TmNKLP40O) were further synthesized and results showed that disulfide bonds are not essential for bactericidal activities of TmNKL, and that both forms of TmNKL exhibited potent bactericidal activities against 4 gram- negative bacteria, including V. parahaemolyticus, V. alginolyticus, Edwardsiella tarda, and V. harveyi. Observed antimicrobial activities are likely due to the effects of TmNKLP40L and TmNKLP40O treatment on disrupting the integrity of both inner and outer membrane of V. parahaemolyticus, resulting in hydrolysis of bacterial genomic DNA. Damaged cell membranes and leakage of intracellular contents were further confirmed using scanning and transmission microscopy. Moreover, administration of 1.0 µg/g TmNKLP40L or TmNKLP40O significantly decreased bacterial load in tissues and thus, pronouncedly enhanced the survival of V. parahaemolyticus-infected fish. Overall, our results demonstrated that TmNKL is a potent innate effector and provides protective effects against bacterial infection.


Asunto(s)
Antiinfecciosos , Enfermedades de los Peces , Tetraodontiformes , Animales , Proteínas de Peces/química , Péptidos , Bacterias Gramnegativas , Antiinfecciosos/farmacología , Enfermedades de los Peces/microbiología
3.
J Phys Chem A ; 127(40): 8473-8485, 2023 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-37768927

RESUMEN

The performance of multistate density functional theory (MSDFT) with nonorthogonal state interaction (NOSI) is assessed for 100 vertical excitation energies against the theoretical best estimates extracted to the full configuration interaction accuracy on the database developed by Loos et al. in 2018 (Loos2018). Two optimization techniques, namely, block-localized excitation and target state optimization, are examined along with two ways of estimating the transition density functional (TDF) for the correlation energy of the Hamiltonian matrix density functional. The results from the two optimization methods are similar. It was found that MSDFT-NOSI using the spin-multiplet degeneracy constraint for the TDF of spin-coupling interaction, along with the M06-2X functional, yields a root-mean-square error (RMSE) of 0.22 eV, which performs noticeably better than time-dependent density functional theory (DFT) at an RMSE of 0.43 eV using the same functional and basis set on the Loos2018 database. In comparison with wave function theory, NOSI has smaller errors than CIS(D∞), LR-CC2, and ADC(3) all of which have an RMSE of 0.28 eV, but somewhat greater than STEOM-CCSD (RMSE of 0.14 eV) and LR-CCSD (RMSE of 0.11 eV) wave function methods. In comparison with Kohn-Sham (KS) DFT calculations, the multistate DFT approach has little double counting of correlation. Importantly, there is no noticeable difference in the performance of MSDFT-NOSI on the valence, Rydberg, singlet, triplet, and double-excitation states. Although the use of another hybrid functional PBE0 leads to a greater RMSE of 0.36 eV, the deviation is systematic with a linear regression slope of 0.994 against the results with M06-2X. The present benchmark reveals that density functional approximations developed for KS-DFT for the ground state with a noninteracting reference may be adopted in MSDFT calculations in which the state interaction is key.

4.
Proc Natl Acad Sci U S A ; 117(25): 13967-13974, 2020 06 23.
Artículo en Inglés | MEDLINE | ID: mdl-32503918

RESUMEN

Molecular dynamics and free energy simulations have been carried out to elucidate the structural origin of differential protein-protein interactions between the common receptor protein angiotensin converting enzyme 2 (ACE2) and the receptor binding domains of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) [A. E. Gorbalenya et al., Nat. Microbiol. 5, 536-544 (2020)] that causes coronavirus disease 2019 (COVID-19) [P. Zhou et al., Nature 579, 270-273 (2020)] and the SARS coronavirus in the 2002-2003 (SARS-CoV) [T. Kuiken et al., Lancet 362, 263-270 (2003)] outbreak. Analysis of the dynamic trajectories reveals that the binding interface consists of a primarily hydrophobic region and a delicate hydrogen-bonding network in the 2019 novel coronavirus. A key mutation from a hydrophobic residue in the SARS-CoV sequence to Lys417 in SARS-CoV-2 creates a salt bridge across the central hydrophobic contact region, which along with polar residue mutations results in greater electrostatic complementarity than that of the SARS-CoV complex. Furthermore, both electrostatic effects and enhanced hydrophobic packing due to removal of four out of five proline residues in a short 12-residue loop lead to conformation shift toward a more tilted binding groove in the complex in comparison with the SARS-CoV complex. On the other hand, hydrophobic contacts in the complex of the SARS-CoV-neutralizing antibody 80R are disrupted in the SARS-CoV-2 homology complex model, which is attributed to failure of recognition of SARS-CoV-2 by 80R.


Asunto(s)
Betacoronavirus/fisiología , Peptidil-Dipeptidasa A/metabolismo , Unión Proteica , Receptores Virales/metabolismo , Aminoácidos/química , Enzima Convertidora de Angiotensina 2 , Anticuerpos Neutralizantes/metabolismo , Anticuerpos Antivirales/metabolismo , COVID-19 , Infecciones por Coronavirus , Humanos , Enlace de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Modelos Moleculares , Simulación de Dinámica Molecular , Pandemias , Neumonía Viral , Dominios Proteicos , SARS-CoV-2 , Electricidad Estática
5.
Fish Shellfish Immunol ; 131: 419-430, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36257553

RESUMEN

Ladderlectin is a member of C-type lectins (CTLs) in teleost fish and involved in innate immune defense. In this study, ayu (Plecoglossus altivelis) ladderlecin-like (PaLL-like) sequence was cloned, which encodes a polypeptide of 172 amino acids that includes a signal peptide and characteristic C-type lectin-like domains (CTLDs). Phylogenetically, PaLL-like was most closely related to its teleost counterpart from shishamo smelt (Spirinchus lanceolatus). Expression analysis revealed a ubiquitous expression profile, with highest expression detected in liver and its expression was up-regulated following Vibiro anguillarum infection. Similar to canonical CTLs, PaLL-like exhibited carbohydrate-binidng capacities to a wide range of well-defined mono-/di-saccharides and likely confer PaLL-like the ability to agglutinate all tested bacterial, including three Gram-positive species (i.e., Listeria monocytogenes, Staphylococcus aureus and Streptococcus iniae) and eight Gram-negative species (i.e., Edwardsiella tarda, Aeromonas (A.) hydrophila, Escherichia coli, Vibrio (V.) harveyi, V. anguillarum, V. parahemolyticus, A. versoni and V. vulnificus), in a calcium-dependent manner. Further functional studies revealed that PaLL-like displayed immunomodulatory activities leading to enhanced bactericidal activity of serum, pathogen opsonization and macrophage activation with increased expression of pro-inflammatory cytokines (i.e., PaIL-1ß and PaTNF-α). Collectively, these immunomodulatory activities of PaLL-like suppressed proliferations of V. anguillarum in targeted tissued in vivo and likely contributed to the increased survival rate of infected-fish. Overall, our results demonstrated PaLL-like is a critical component of innate immunity and provides protective effects against bacterial infection.


Asunto(s)
Enfermedades de los Peces , Osmeriformes , Vibriosis , Animales , Osmeriformes/genética , Proteínas de Peces/química , Alineación de Secuencia , Regulación de la Expresión Génica , Secuencia de Aminoácidos , Filogenia , Inmunidad Innata/genética , Lectinas Tipo C/genética
6.
Molecules ; 26(24)2021 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-34946769

RESUMEN

Deuterium isotope effects on acid-base equilibrium have been investigated using a combined path integral and free-energy perturbation simulation method. To understand the origin of the linear free-energy relationship of ΔpKa=pKaD2O-pKaH2O versus pKaH2O, we examined two theoretical models for computing the deuterium isotope effects. In Model 1, only the intrinsic isotope exchange effect of the acid itself in water was included by replacing the titratable protons with deuterons. Here, the dominant contribution is due to the difference in zero-point energy between the two isotopologues. In Model 2, the medium isotope effects are considered, in which the free energy change as a result of replacing H2O by D2O in solute-solvent hydrogen-bonding complexes is determined. Although the average ΔpKa change from Model 1 was found to be in reasonable agreement with the experimental average result, the pKaH2O dependence of the solvent isotope effects is absent. A linear free-energy relationship is obtained by including the medium effect in Model 2, and the main factor is due to solvent isotope effects in the anion-water complexes. The present study highlights the significant roles of both the intrinsic isotope exchange effect and the medium solvent isotope effect.

7.
Molecules ; 23(10)2018 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-30326599

RESUMEN

A dual QM and MM approach for computing equilibrium isotope effects has been described. In the first partition, the potential energy surface is represented by a combined quantum mechanical and molecular mechanical (QM/MM) method, in which a solute molecule is treated quantum mechanically, and the remaining solvent molecules are approximated classically by molecular mechanics. In the second QM/MM partition, differential nuclear quantum effects responsible for the isotope effect are determined by a statistical mechanical double-averaging formalism, in which the nuclear centroid distribution is sampled classically by Newtonian molecular dynamics and the quantum mechanical spread of quantized particles about the centroid positions is treated using the path integral (PI) method. These partitions allow the potential energy surface to be properly represented such that the solute part is free of nuclear quantum effects for nuclear quantum mechanical simulations, and the double-averaging approach has the advantage of sampling efficiency for solvent configuration and for path integral convergence. Importantly, computational precision is achieved through free energy perturbation (FEP) theory to alchemically mutate one isotope into another. The PI-FEP approach is applied to model systems for the 18O enrichment found in cellulose of trees to determine the isotope enrichment factor of carbonyl compounds in water. The present method may be useful as a general tool for studying isotope fractionation in biological and geochemical systems.


Asunto(s)
Celulosa/análisis , Isótopos de Oxígeno/análisis , Árboles/química , Fraccionamiento Químico , Modelos Moleculares , Simulación de Dinámica Molecular , Teoría Cuántica , Agua/análisis
8.
Zhonghua Nei Ke Za Zhi ; 55(2): 111-5, 2016 Feb.
Artículo en Zh | MEDLINE | ID: mdl-26875579

RESUMEN

OBJECTIVE: To explore the clinical significance of a series of cytokines and peripheral blood immunocyte subsets before and after immunosuppressive therapy in patients with immune thrombocytopenia (ITP). METHODS: The percentages of immunocyte subsets in the peripheral blood of 20 patients with ITP and 20 healthy controls were detected by flow cytometry, including CD3(+), CD4(+), CD8(+), CD4(+)/CD8(+), CD19(+). ELISA was applied to detect the level of serum TNFα, IL-2, IL-6, IL-4, IL-10, IL-11, IL-17, IL-27, transforming growth factor ß (TGFß), thrombopoietin (TPO) of 20 patients with ITP and 20 healthy controls. RESULTS: The percentage of CD3(+) T lymphocyte, CD4(+) T lymphocyte and the ratio of CD4(+)/CD8(+) T lymphocyte in patients with ITP were lower than those in healthy controls[(62.66 ± 6.58)% vs (69.93 ± 4.81)%, (29.46 ± 5.02)% vs (39.08 ± 3.50)%, 0.97 ± 0.35 vs 1.56 ± 0.26, all P<0.05]. After immunosuppressive therapy, the percentage of CD3(+) T lymphocyte, CD4(+) T lymphocyte and the ratio of CD4(+)/CD8(+) T lymphocyte [(71.49 ± 5.16)%, (39.25 ± 3.21)% and 1.56 ± 0.28] recovered to the same levels in healthy controls. The percentage of CD8(+) T lymphocyte and CD19(+) B lymphocyte in patients with ITP were higher than those in the healthy controls [(30.28 ± 4.63)% vs (25.90 ± 3.06)%, (18.92 ± 4.27)% vs (13.17 ± 3.64)%, all P<0.05]. After treatment of immunosuppressive therapy, the percentage of CD8(+) T lymphocyte and CD19(+) B lymphocyte [(25.16 ± 3.45)% and (11.98 ± 3.68)%] recovered to the similar levels in healthy controls. The serum levels of IL-4, IL-6, IL-11, IL-17 and TPO in patients with ITP were significantly higher than those in healthy controls. While TGFß level was significantly decreased. There was no significant difference of IL-27 between ITP patients and healthy controls. After the treatment of immunosuppressive therapy, IL-4, IL-6, IL-11, IL-17, TPO and TGFß were down-regulated while IL-27 was up-regulated. There was no significant difference of IFNγ, TNFα, IL-2 and IL-10 among ITP patients before or after immunosuppressive therapy and healthy controls. CONCLUSIONS: The present study suggests that the aberrant immunocyte subsets and cytokines are involved in the pathogenesis of ITP. Hyper-function of Th2 and Th17, dysfunction of Treg cells, up-regulation of IL-27, IL-11, TPO and other factors may contribute to the pathogenesis of ITP.


Asunto(s)
Linfocitos B/citología , Citocinas/sangre , Terapia de Inmunosupresión , Púrpura Trombocitopénica Idiopática/sangre , Púrpura Trombocitopénica Idiopática/inmunología , Linfocitos T Reguladores/citología , Células Th17/citología , Estudios de Casos y Controles , Citometría de Flujo , Humanos , Púrpura Trombocitopénica Idiopática/tratamiento farmacológico
9.
Isr J Chem ; 54(8-9): 1250-1263, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29386687

RESUMEN

The 2013 Nobel Prize in Chemistry was awarded to the authors of the first two publications utilizing the concept of combined quantum mechanical and molecular mechanical (QM/MM) methods. In celebrating this great event in computational chemistry, we review the early development of combined QM/MM techniques and the associated events that took place through the mid-1990s. We also offer some prospects for the future development of quantum mechanical techniques for macromolecular systems.

10.
Materials (Basel) ; 17(16)2024 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-39203240

RESUMEN

Calcium phosphate, particularly hydroxyapatite (HA), bears a close resemblance to human bones, rendering it a prevalent material in biomedical applications. This study focuses on the successful preparation of HA using a precipitation method with eggshell as a raw material. Subsequently, the HA powder was press-formed and sintered at various temperatures to investigate the impact of sintering temperature on the mechanical properties, including hardness, compressive strength, and fracture toughness, of the sintered HA samples (E-HA). Statistical analyses, including one-way ANOVA and Tukey's post-hoc test, were conducted to determine significant differences in these properties at different sintering temperatures. Experimental findings revealed that as the sintering temperature increased, HA partially transformed into ß-TCP between 800 and 1300 °C, with α-TCP observed at 1400 °C. The elimination of pores led to an increase in relative density, with a maximum relative density of 94.5% achieved at 1200 and 1300 °C. E-HA sintered at 1200 °C exhibited the highest hardness (5.08 GPa), compressive strength (255.79 MPa), and fracture toughness (1.21 MPa·m0.5). However, at 1400 °C, a slight decrease in apparent density (2.90 g/cm3) was noted due to the presence of α-TCP, along with significant grain growth. This study's objective is clearly aligned with the study design, incorporating detailed statistical analyses to validate the findings. Furthermore, bacterial culture experiments were conducted using sintered E-HA, Chem-HA (HA synthesized from reagent-grade calcium carbonate), and Comm-HA (commercial HA). Streptococcus mutans was cultured on the surfaces of sintered E-HA, Chem-HA, and Comm-HA samples for 20 h. After culturing, the OD values for all samples were below 0.2, indicating significant antibacterial efficacy. The comparable OD values and bacterial counts (p > 0.05) suggest that the source of HA does not impact its antibacterial properties. This underscores the potential of eggshell-derived HA as an effective material for biomedical applications.

11.
J Ethnopharmacol ; 328: 118000, 2024 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-38527574

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Xiaoer Niuhuang Qingxin Powder (XNQP) is a classic traditional Chinese medicine formula with significant clinical efficacy for treating febrile convulsions and influenza. AIM OF THE STUDY: This study aims to explore the potential mechanisms of XNQP in combating combating the influenza A virus, providing a theoretical basis for its clinical application. MATERIALS AND METHODS: The present investigation employed network pharmacology and bioinformatics analysis to determine the TLR4/MyD88/NF-κB signaling pathway as a viable target for XNQP intervention in IAV infection.Subsequently, a mouse model of influenza A virus infection was established, and different doses of XNQP were used for intervention. The protein expression levels of TLR4/MyD88/NF-κB were detected using HE staining, Elisa, immunohistochemistry, immunofluorescence, and western blot. RESULTS: The results showed that treatment with XNQP after IAV infection reduced the mortality and prolonged the survival time of infected mice. It reduced the release of TNF-α and IFN-γ in the serum and alleviated pathological damage in the lung tissue following infection. Additionally, the levels of TLR4, MyD88, NF-κB, and p-NF-κB P65 proteins were significantly reduced in lung tissue by XNQP. The inhibitory effect of XNQP on the expression of MyD88 and NF-κB was antagonized when TLR4 signaling was overexpressed. Consequently, the expression levels of MyD88, NF-κB, and p-NF-κB P65 were increased in lung tissue. Conversely, the expression levels of the proteins MyD88, NF-κB, and p-NF-κB P65 were downregulated when TLR4 signaling was inhibited. CONCLUSIONS: XNQP alleviated lung pathological changes, reduced serum levels of inflammatory factors, reduced mortality, and prolonged survival time in mice by inhibiting the overexpression of the TLR4/MyD88/NF-κB signaling pathway in lung tissues after IAV infection.


Asunto(s)
Medicamentos Herbarios Chinos , Virus de la Influenza A , Gripe Humana , Ratones , Animales , Humanos , FN-kappa B/metabolismo , Receptor Toll-Like 4/metabolismo , Factor 88 de Diferenciación Mieloide/metabolismo , Polvos , Transducción de Señal
12.
ACS Nano ; 18(9): 6946-6962, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38377037

RESUMEN

Pyroptosis mediated by gasdermin protein has shown great potential in cancer immunotherapies. However, the low expression of gasdermin proteins and the systemic toxicity of nonspecific pyroptosis limit its clinical application. Here, we designed a synthetic biology strategy to construct a tumor-specific pyroptosis-inducing nanoplatform M-CNP/Mn@pPHS, in which a pyroptosis-inducing plasmid (pPHS) was loaded onto a manganese (Mn)-doped calcium carbonate nanoparticle and wrapped in a tumor-derived cell membrane. M-CNP/Mn@pPHS showed an efficient tumor targeting ability. After its internalization by tumor cells, the degradation of M-CNP/Mn@pPHS in the acidic endosomal environment allowed the efficient endosomal escape of plasmid pPHS. To trigger tumor-specific pyroptosis, pPHS was designed according to the logic "AND gate circuit" strategy, with Hif-1α and Sox4 as two input signals and gasdermin D induced pyroptosis as output signal. Only in cells with high expression of Hif-1α and Sox4 simultaneously will the output signal gasdermin D be expressed. Since Hif-1α and Sox4 are both specifically expressed in tumor cells, M-CNP/Mn@pPHS induces the tumor-specific expression of gasdermin D and thus pyroptosis, triggering an efficient immune response with little systemic toxicity. The Mn2+ released from the nanoplatform further enhanced the antitumor immune response by stimulating the cGAS-STING pathway. Thus, M-CNP/Mn@pPHS efficiently inhibited tumor growth with 79.8% tumor regression in vivo. We demonstrate that this logic "AND gate circuit"-based gasdermin nanoplatform is a promising strategy for inducing tumor-specific pyroptosis with little systemic toxicity.


Asunto(s)
Neoplasias , Piroptosis , Humanos , Gasderminas , Péptidos y Proteínas de Señalización Intracelular , Neoplasias/terapia , Inmunoterapia , Lógica
13.
J Control Release ; 367: 61-75, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38242210

RESUMEN

Pyroptosis, mediated by gasdermin proteins, has shown excellent efficacy in facilitating cancer immunotherapy. The strategies commonly used to induce pyroptosis suffer from a lack of tissue specificity, resulting in the nonselective activation of pyroptosis and consequent systemic toxicity. Moreover, pyroptosis activation usually depends on caspase, which can induce inflammation and metabolic disorders. In this study, inspired by the tumor-specific expression of SRY-box transcription factor 4 (Sox4) and matrix metalloproteinase 2 (MMP2), we constructed a doubly regulated plasmid, pGMD, that expresses a biomimetic gasdermin D (GSDMD) protein to induce the caspase-independent pyroptosis of tumor cells. To deliver pGMD to tumor cells, we used a hyaluronic acid (HA)-shelled calcium carbonate nanoplatform, H-CNP@pGMD, which effectively degrades in the acidic endosomal environment, releasing pGMD into the cytoplasm of tumor cells. Upon the initiation of Sox4, biomimetic GSDMD was expressed and cleaved by MMP2 to induce tumor-cell-specific pyroptosis. H-CNP@pGMD effectively inhibited tumor growth and induced strong immune memory effects, preventing tumor recurrence. We demonstrate that H-CNP@pGMD-induced biomimetic GSDMD expression and tumor-specific pyroptosis provide a novel approach to boost cancer immunotherapy.


Asunto(s)
Neoplasias , Piroptosis , Humanos , Metaloproteinasa 2 de la Matriz/metabolismo , Gasderminas , Biomimética , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas de Neoplasias/farmacología , Caspasas/metabolismo , Caspasas/farmacología , Neoplasias/terapia
14.
J Phys Chem Lett ; 14(12): 2917-2926, 2023 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-36929896

RESUMEN

A multistate energy decomposition analysis (MS-EDA) method is introduced for excimers using density functional theory. Although EDA has been widely applied to intermolecular interactions in the ground state, few methods are currently available for excited-state complexes. Here, the total energy of an excimer state is separated into exciton excitation energy ΔEEx(|ΨX·ΨY⟩*), resulting from the state interaction between locally excited monomer states |ΨX*·ΨY⟩ and |ΨX·ΨY*⟩ , a superexchange stabilization energy ΔESE, originating from the mutual charge transfer between two monomers |ΨX+·ΨY⟩ and |ΨX-·ΨY+⟩ , and an orbital-and-configuration delocalization term ΔEOCD due to the expansion of configuration space and block-localized orbitals to the fully delocalized dimer system. Although there is no net charge transfer in symmetric excimer cases, the resonance of charge-transfer states is critical to stabilizing the excimer. The monomer localized excited and charge-transfer states are variationally optimized, forming a minimal active space for nonorthogonal state interaction (NOSI) calculations in multistate density functional theory to yield the intermediate states for energy analysis. The present MS-EDA method focuses on properties unique to excited states, providing insights into exciton coupling, superexchange and delocalization energies. MS-EDA is illustrated on the acetone and pentacene excimer systems; three configurations of the latter case are examined, including the optimized excimer, a stacked configuration of two pentacene molecules and the fishbone orientation. It is found that excited-state energy splitting is strongly dependent on the relative energies of the monomer excited states and the phase-matching of the monomer wave functions.

15.
Food Chem ; 425: 136449, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37295213

RESUMEN

Accurate on-site analysis of tetracycline (TC) is of great research value for ensuring food safety and estimating environmental pollution. Herein, a smartphone-based fluorescent platform for TC detectionhas been developed based on a europium functionalized metal-organic framework (Zr-MOF/Cit-Eu). Based on the inner filter and antenna effect between Zr-MOF/Cit-Eu and TC, the probe exhibited a ratiometric fluorescent response toward TC, resulting in an emission color change from blue to red. Excellent sensing performance was achieved with a detection limit of 3.9 nM, consistent with the linear operation spanning nearly four orders of magnitude. Subsequently, visual test strips based on Zr-MOF/Cit-Eu were prepared, possessing the potential for accurate testing of TC via RGB signals. Finally, the proposed platform was well applied in actual samples with satisfied recoveries (92.27 to 110.22%). This MOF-based on-site fluorescent platform holds great potential on constructing intelligent platform for visual and quantitative detection of organic contaminants.


Asunto(s)
Europio , Teléfono Inteligente , Colorantes Fluorescentes , Tetraciclina , Antibacterianos/análisis , Espectrometría de Fluorescencia/métodos
16.
JACS Au ; 3(7): 1800-1819, 2023 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-37502166

RESUMEN

A multistate energy decomposition analysis (MS-EDA) method is described to dissect the energy components in molecular complexes in excited states. In MS-EDA, the total binding energy of an excimer or an exciplex is partitioned into a ground-state term, called local interaction energy, and excited-state contributions that include exciton excitation energy, superexchange stabilization, and orbital and configuration-state delocalization. An important feature of MS-EDA is that key intermediate states associated with different energy terms can be variationally optimized, providing quantitative insights into widely used physical concepts such as exciton delocalization and superexchange charge-transfer effects in excited states. By introducing structure-weighted adiabatic excitation energy as the minimum photoexcitation energy needed to produce an excited-state complex, the binding energy of an exciplex and excimer can be defined. On the basis of the nature of intermolecular forces through MS-EDA analysis, it was found that molecular complexes in the excited states can be classified into three main categories, including (1) encounter excited-state complex, (2) charge-transfer exciplex, and (3) intimate excimer or exciplex. The illustrative examples in this Perspective highlight the interplay of local excitation polarization, exciton resonance, and superexchange effects in molecular excited states. It is hoped that MS-EDA can be a useful tool for understanding photochemical and photobiological processes.

17.
J Ethnopharmacol ; 304: 116070, 2023 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-36549371

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Mahuang Xixin Fuzi Decoction (MXF), as a classical prescription of traditional Chinese medicine (TCM), has been used to treat the immunocompromised individuals infected with influenza A virus (IAV). AIM OF THE STUDY: The study aims to explore the regulatory of MXF on inflammation and secretory immunoglobulin A (SIgA) antibodies immune response in BALB/c-nude mice infected with IAV. MATERIALS AND METHODS: The BALB/c-nude mice were infected with IAV, then different dosages of MXF were orally administrated to the mice. The weight, rectal temperature, spontaneous activity, spleen index, lung index, pathological changes of lung tissues, and the relative mRNA expression level of H1N1 M gene were measured for the purpose of valuing the antiviral effect of MXF. The expression levels of cytokines in lungs and immunoglobulin A (IgA) in serum of BALB/c-nude mice were determined with Cytometric Bead Array System (CBA). SIgA in bronchoalveolar lavage fluids (BALF) was detected with Enzyme-linked Immunosorbent Assay (ELISA). The mRNA and protein expression levels of B cell activating factor (BAFF), chemokine receptors 10 (CCR10), and polymeric immunoglobulin receptor (pIgR) in the lung tissues, which are related to the secretion of SIgA, were determined by using RT-PCR and Western blot. RESULTS: MXF could alleviate the clinical features and reduce the severity of viral lung lesions, including improving the body weight, rectal temperature and spontaneous activity of nude mice infected with IAV, increasing spleen index, decreasing lung index, alleviating pathological damage, and decreasing the relative expression level of H1N1 M gene. Levels of pro-inflammatory cytokines, including interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interleukin-2 (IL-2), interleukin-12p70 (IL-12p70), and interleukin-17A (IL-17A) were also significantly decreased after treatment with MXF. Interferon-γ (IFN-γ), an antiviral cytokine, was significantly up-regulated in high dose MXF (3.12 g/kg) group. Moreover, after MXF treatment, the expressions of SIgA in BALF and IgA in serum were both at relatively low levels. And the mRNA and protein expressions of BAFF, CCR10, and pIgR were significantly decreased after treatment with MXF. CONCLUSIONS: MXF has obviously protective effects on BALB/c-nude mice infected with IAV by inhibiting virus replication, calming inflammatory cytokine storm, and regulating SIgA immune response weakly.


Asunto(s)
Subtipo H1N1 del Virus de la Influenza A , Virus de la Influenza A , Infecciones por Orthomyxoviridae , Animales , Ratones , Citocinas/metabolismo , Ratones Desnudos , Inmunoglobulina A Secretora/metabolismo , Antivirales/farmacología , Pulmón , Inmunidad , ARN Mensajero/metabolismo , Ratones Endogámicos BALB C
18.
Guang Pu Xue Yu Guang Pu Fen Xi ; 32(7): 1972-4, 2012 Jul.
Artículo en Zh | MEDLINE | ID: mdl-23016366

RESUMEN

The contents of various elements in rhizoma dioscoreae were analyzed and compared with those of shishou D. opposita Thunb on the whole jointly by XRF and PXRD. The results showed that the element Cu, Al and Mn could not be detected in rhizoma dioscoreae, but the element Mg, Zn and Cr were found, and other elements contents changed to different degrees; there are starch and whewellite in both groups, the crystal type of starches separated from rhizoma dioscoreae cultivars was a typical B-type pattern, but as C-type and V-type in shishou D. opposita Thunb, which is a mixture of A-type, B-type and V-type. The combination of two testing techniques could be applied to the mensuration and analysis of the elements and micro-structural of Dioscorea opposita Thunb which could be from different producing areas.


Asunto(s)
Dioscorea/química , Almidón/análisis , Rizoma/química , Espectrometría de Fluorescencia , Espectrometría por Rayos X , Difracción de Rayos X
19.
Guang Pu Xue Yu Guang Pu Fen Xi ; 32(3): 660-3, 2012 Mar.
Artículo en Zh | MEDLINE | ID: mdl-22582627

RESUMEN

The major components of the 4th generation outer space bred angelica and the ground group were determined and analyzed by Fourier transform infrared spectroscopy (FTIR) and second derivative spectrum, considering the large mutation of the plants with space mutagenesis. The results show that the content of the coumarin (1741 cm(-1)), which is the main active components of the space angelica dahurica increased, and the content of the protein (1 459, 1 419 cm(-1)) and the fat (930 cm(-1)) increased slightly, whereas the content of the starch and the dietary fiber reduced drastically. There are obvious differences between the peak values of the second derivative spectra of the plants, revealing that the outer space angelica dahurica contained amine component at 1 279 cm(-1). Space mutation breeding is favor of breeding angelica with better idiosyncrasy.


Asunto(s)
Angelica , Espectroscopía Infrarroja por Transformada de Fourier , Cruzamiento , Medio Ambiente Extraterrestre , Mutagénesis , Mutación
20.
Guang Pu Xue Yu Guang Pu Fen Xi ; 32(2): 545-7, 2012 Feb.
Artículo en Zh | MEDLINE | ID: mdl-22512208

RESUMEN

The contents of various elements in the fourth generation atractylodes macrocephala koidz cultivated by spaceflight breeding were analyzed and compared with those of the ground group on the whole jointly by XRF and PXRD. The results showed that the element Na and Ti could not be detected in the space group, and the levels of K and Mn were enhanced by 1.16 and 1.15 times as these elements were measured in ground group, but other elements' contents declined to different degrees, and the most notable elements are Si and P, decreasing by 82.1% and 71.2% accordingly; there is some whewellite in the ground group, whereas much less is found in the space group. The ground group contains inulin, however none in the space group. Spaceflight breeding can harvest significantly mutated specific Chinese herbal medicines varieties. The combination of two testing techniques has a positive role in space breeding applied in cultivation of medicinal plants.


Asunto(s)
Atractylodes , Plantas Medicinales , Vuelo Espacial , Cruzamiento
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