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Magnetic skyrmions are promising as next-generation information units. Their antiparticle-the antiskyrmion-has also been discovered in chiral magnets. Here we experimentally demonstrate antiskyrmion sliding in response to a pulsed electric current at room temperature without the requirement of an external magnetic field. This is realized by embedding antiskyrmions in helical stripe domains, which naturally provide one-dimensional straight tracks along which antiskyrmion sliding can be easily launched with low current density and without transverse deflection from the antiskyrmion Hall effect. The higher mobility of the antiskyrmions in the background of helical stripes in contrast to the typical ferromagnetic state is a result of intrinsic material parameters and elastic energy of the stripe domain, thereby smearing out the random pinning potential, as supported by micromagnetic simulations. The demonstration and comprehensive understanding of antiskyrmion movement along naturally straight tracks offers a new perspective for (anti)skyrmion application in spintronics.
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Structure engineering of magnetic-dielectric multi-components is emerging as an effective approach for presuming high-performance electromagnetic (EM) absorption, but still faces bottlenecks due to the ambiguous regulation mechanism of surface morphology. Here, a novel wrinkled surface structure is tailored on the ZnFe2O4 microsphere via a spray-pyrolysis induced Kirkendall diffusion effect, the conductivity of the sample is affected, and a better impedance matching is adjusted by modulating the concentration of metal nitrate precursors. Driven by a vapor phase polymerization, conductive polypyrrole (PPy) shell are in situ decorated on the ZnFe2O4 microsphere surfaces, ingeniously constructing a core-shell ZnFe2O4@PPy composites. Moreover, a systematic investigation reveals that this unique wrinkled surface structure is highly dependent on the metal salt concentration. Optimized wrinkle ZnFe2O4@PPy composite exhibits a minimum reflection loss (RLmin) reached -41.0 dB and the effective absorption bandwidth (EAB) can cover as wide as 4.1 GHz. The enhanced interfacial polarization originated from high-density ZnFe2O4-PPy heterostructure, and the conduction loss of PPy contributes to the boosted dielectric loss capability. This study gives a significant guidance for preparing high-performance EM composites by tailoring the surface wrinkle structure.
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Toxoplasma gondii (T.gondii) can influence the host's neurotransmission, central immune responses, and brain structure, potentially impacting the onset and development of various psychiatric disorders such as schizophrenia. We employed Electrochemiluminescence Immunoassay (ECLIA) to measure anti-Toxoplasma antibodies in 451 schizophrenic patients and 478 individuals from the general population in Hunan, China. The incidence rate of T.gondii infection in schizophrenic patients (8.87 %) was higher than that in the general population (3.77 %). A significant difference was observed among females, but not in males. Age-stratified analysis revealed significant differences in the 21-40 and 41-60 age groups. The two populations had no significant difference in the antibody titer for T. gondii infection. Additionally, the profile of circulating metabolites in the serum of schizophrenic patients with or without T. gondii infection was examined using non-targeted metabolomics assay. A total of 68 metabolites were differentially expressed between Toxoplasma-positive and Toxoplasma-negative groups, potentially mediating the connection between T. gondii infection and schizophrenia. Our research suggests that schizophrenic patients are susceptible to T. gondii infection with distinct metabolic program.
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The identification of MHC class I-restricted CTL epitopes in certain species, particularly nonmammals, remains a challenge. In this study, we developed a four-step identification scheme and confirmed its efficiency by identifying the Anpl-UAA*76-restricted CTL epitopes of Tembusu virus (TMUV) in inbred haplotype ducks HBW/B4. First, the peptide binding motif of Anpl-UAA*76 was determined by random peptide library in de novo liquid chromatography-tandem mass spectrometry, a novel nonbiased, data-independent acquisition method that we previously established. Second, a total of 38 TMUV peptides matching the motif were screened from the viral proteome, among which 11 peptides were conserved across the different TMUV strains. Third, the conserved TMUV peptides were refolded in vitro with Anpl-UAA*76 and Anpl-ß2-microglobulin to verify the results from the previous two steps. To clarify the structural basis of the obtained motif, we resolved the crystal structure of Anpl-UAA*76 with the TMUV NS3 peptide LRKRQLTVL and found that Asp34 is critical for the preferential binding of the B pocket to bind the second residue to arginine as an anchor residue. Fourth, the immunogenicity of the conserved TMUV peptides was tested in vivo using specific pathogen-free HBW/B4 ducks immunized with the attenuated TMUV vaccine. All 11 conserved TMUV epitopes could bind stably to Anpl-UAA*76 in vitro and stimulate the secretion of IFN-γ and lymphocyte proliferation, and three conserved and one nonconserved peptides were selected to evaluate the CTL responses in vivo by flow cytometry and their tetramers. We believe that this new scheme could improve the identification of MHC class I-restricted CTL epitopes, and our data provide a foundation for further study on duck anti-TMUV CTL immunity.
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Patos , Flavivirus , Animales , Epítopos , Péptidos , Linfocitos T CitotóxicosRESUMEN
Several cellular processes, including the recovery of misfolded proteins, the folding of polypeptide chains, transit of polypeptides across the membrane, construction and disassembly of protein complexes, and modulation of protein control, are carried out by DnaJ homolog subfamily A member 1 (DNAJA1), which belongs to the DnaJ heat-shock protein family. It is unknown if DNAJA1 regulates the production of milk in bovine mammary epithelium cells (BMECs). Methionine and leucine increased DNAJA1 expression and nuclear location, as seen by us. In contrast to DNAJA1 knockdown, overexpression of DNAJA1 boosted the production of milk proteins and fats as well as mammalian target of rapamycin (mTOR) and sterol regulatory element binding protein-1c (SREBP-1c). As a result of amino acids, mTOR and SREBP-1c gene expression are stimulated, and DNAJA1 is a positive regulator of BMECs' amino acid-induced controlled milk protein and fat production.
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Células Epiteliales , Proteínas de la Leche , Animales , Bovinos , Aminoácidos , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/genética , Serina-Treonina Quinasas TORRESUMEN
Over the past decades, the synthetic glucocorticoids (GCs) have been widely used in clinical practice and animal husbandry. Given the health hazard of these toxic residues in food, it is necessary to explore the detailed interaction mechanisms of typical GCs and their main target glucocorticoid receptor (GR). Hence, this work compared the GR binding and agonist activities of typical GCs. Fluorescence polarization assay showed that these GCs were potent ligands of GR. Their GR binding affinities were in the order of methylprednisolone>betamethasone≈prednisolone>dexamethasone, with IC50 values of 1.67, 2.94, 2.95, and 5.58â nM. Additionally, the limits of detection of dexamethasone, betamethasone, prednisolone, and methylprednisolone were 0.32, 0.14, 0.19, and 0.09â µg/kg in fluorescence polarization assay. Reporter gene assay showed that these GCs induced GR transactivation in a dose-dependent manner, confirming their GR agonist activities. Among which, dexamethasone at the concentration of 100â nM produced a maximal induction of more than 11-fold over the blank control. Molecular docking and molecular dynamics simulations suggested that hydrogen-bonding and hydrophobic interactions played an important role in stabilizing the GC-GR-LBD complexes. In summary, this work might help to understand the GR-mediated endocrine disrupting effects of typical GCs.
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Glucocorticoides , Receptores de Glucocorticoides , Animales , Glucocorticoides/farmacología , Glucocorticoides/química , Glucocorticoides/metabolismo , Receptores de Glucocorticoides/química , Receptores de Glucocorticoides/genética , Receptores de Glucocorticoides/metabolismo , Simulación del Acoplamiento Molecular , Dexametasona/farmacología , Dexametasona/química , Dexametasona/metabolismo , MetilprednisolonaRESUMEN
The classical lytic infection theory along with large T antigen-mediated oncogenesis cannot explain the BK polyomavirus (BKPyV)-associated tumor secondary to BKPyV-associated nephropathy (BKVAN), viremia/DNAemia, and viruria after renal transplantation. This study performed virome capture sequencing and pathological examination on regularly collected urine sediment and peripheral blood samples, and BKVAN and tumor biopsy tissues of 20 patients with BKPyV-associated diseases of different stages. In the early noncancerous stages, well-amplified integration sites were visualized by in situ polymerase chain reaction, simultaneously with BKPyV inclusion bodies and capsid protein expression. The integration intensity, the proportion of microhomology-mediated end-joining integration, and host PARP-1 and POLQ gene expression levels increased with disease progression. Furthermore, multiomics analysis was performed on BKPyV-associated urothelial carcinoma tissues, identifying tandem-like structures of BKPyV integration using long-read genome sequencing. The carcinogenicity of BKPyV integration was proven to disturb host gene expression and increase viral oncoprotein expression. Fallible DNA double-strand break repair pathways were significantly activated in the parenchyma of BKPyV-associated tumors. Olaparib showed an antitumor activity dose-response effect in the tumor organoids without BRCA1/2 genes mutation. In conclusion, the dynamic viral integration patterns actively participate in the progression of BKPyV-associated diseases and thus could be a potential target for disease monitoring and intervention.
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Virus BK , Carcinoma de Células Transicionales , Trasplante de Riñón , Nefritis Intersticial , Infecciones por Polyomavirus , Infecciones Tumorales por Virus , Neoplasias de la Vejiga Urinaria , Humanos , Trasplante de Riñón/efectos adversos , Virus BK/genética , Proteína BRCA1/genética , Proteína BRCA2/genética , Integración Viral , Infecciones Tumorales por Virus/etiologíaRESUMEN
BACKGROUND AND OBJECTIVES: The Dombrock blood group system is based on the DO gene. DO*A and DO*B antigens are the result of a single-nucleotide polymorphism (SNP) on this gene. The introduction of Do antigens through blood transfusion or other invasive factors like infection may result in the production of Do antibodies, which may cause serious haemolytic transfusion reactions. In this study, TaqMan real-time PCR and droplet digital PCR were used to detect rare DO*A allele, guide the search for rare DO*A allele donors, and calculate DO alleles frequencies in mixed populations in Northwest China. MATERIALS AND METHODS: In this study, the highly sensitive and accurate TaqMan real-time polymerase chain reaction (PCR) method was used to detect and screen DO genotype SNPs in combination with droplet digital PCR. We also searched for rare DO*A allele donors and calculated the frequencies of DO alleles in mixed populations. RESULTS: A total of 1202 donor DNA samples were collected from Northwest China, of which 202 were used to detect DO allele SNPs using TaqMan real-time PCR. The rare DO*A allele was detected in the other 1000 blood donors by droplet digital PCR, and gene frequencies were inferred from dual channel droplet digital PCR data. Among 1202 donors from Northwest China, the allele frequencies of DO*A and DO*B were 0.1128 and 0.8872, respectively. CONCLUSION: The sequencing results confirmed that this new way of detecting DO alleles by droplet digital PCR with specific probes can detect rare DO*A allele to predict the presence of the rare antigen Doa and infer DO allele frequencies. This method is highly sensitive and specific.
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Antígenos de Grupos Sanguíneos , Humanos , Reacción en Cadena en Tiempo Real de la Polimerasa , Genotipo , Alelos , Frecuencia de los Genes , Antígenos de Grupos Sanguíneos/genética , Polimorfismo de Nucleótido SimpleRESUMEN
This study aimed to investigate the interaction between 24-Epibrassinolide (EBR) and melatonin (MT) and their effects on cadmium (Cd)-stressed Primula forbesii Franch. P. forbesii seedlings were hydroponically acclimatized at 6-7 weeks, then treated with Cd (200 µmol L-1), 24-EBR (0.1 µmol L-1), and MT (100 µmol L-1) after two weeks. Cd stress significantly reduced crown width, shoot, root length, shoot fresh weight, and fresh and dry root weights. Herein, 24-EBR, MT, and 24-EBR+MT treatments attenuated the growth inhibition caused by Cd stress and improved the morphology, growth indexes, and ornamental characteristics of P. forbesii under Cd stress. 24-EBR had the best effect by effectively alleviating Cd stress and promoting plant growth and development. 24-EBR significantly increased all growth parameters compared to Cd treatment. In addition, 24-EBR significantly improved the gas exchange parameters, activities of antioxidant enzymes, and the cycle efficiency of AsA-GSH. Furthermore, 24-EBR increased the activities of ascorbate peroxidase (APX), glutathione reductase (GR), dehydroascorbate reductase (DHAR), and monodehydroascorbate reductase (MDHAR) by 127.29%, 61.31%, 61.22%, and 51.04%, respectively, compared with the Cd treatment. Therefore, 24-EBR removed the reactive oxygen species produced by stress, thus protecting plants against stress damage. These results indicate that 24-EBR can effectively enhance the tolerance of P. forbesii to Cd stress.
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The development of efficient and stable Pd-based electrocatalysts is extremely important to facilitate the development of catalysts for polyol oxidation reactions. To synthesize Pd-based catalysts with excellent catalytic performance, a series of PdAg porous nanowires (PdAg PNWs) with different elemental ratios was constructed by facile synthesis using a seed-mediated method. The synthesized PdAg PNWs have a rough surface and a porous one-dimensional structure, which optimize the specific surface area and surface area of catalysts, thereby providing more active sites for catalysts. PdAg PNWs benefited from the geometric effect of porous nanowires and the synergy between Pd and Ag, showing excellent catalysis (8243.0 and 4137.0 mA mgPd-1) for the ethylene glycol oxidation reaction (EGOR) and glycerol oxidation reaction (GOR). Among them, the optimal Pd62Ag38 PNWs show the highest catalytic activity (6.0 times and 3.9 times higher than Pd/C) and stability compared with Pd57Ag43 PNWs, Pd51Ag49 PNWs, and Pd/C for EGOR and GOR. At the same time, this porous one-dimensional structure also endows PdAg PNWs with faster electron transfer capabilities than Pd/C. This work will likely provide an effective strategy for constructing cost-effective catalysts.
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Phthalate esters (PAEs) are important pollutants in the environment, which can interfere with the endocrine system by mimicking estrogen. However, limited information is available on modulating the estrogen receptor (ER) of five PAEs including di (2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DINP), benzyl butyl phthalate (BBP), diphenyl phthalate (DPhP) and dicyclohexyl phthalate (DCHP). This study evaluated the agonistic effects of PAEs on human ER. The cytotoxicity assay showed that there were a significant inhibition of the cell proliferation with treatment of five PAEs. Moreover, DPhP does-dependently enhanced ER-mediated transcriptional activity in the reporter gene assay. The increased expression of estrogen-responsive genes (TFF1, CTSD, and GREB1) was also observed in MCF-7 cells treated with DPhP. The result of molecular docking showed that DPhP tended to bind to the agonist conformation of ER compared with the antagonist conformation of ER, demonstrating its agonist characteristic that has been confirmed in the reporter gene assay. Thus, we found that DPhP may be evaluated as an ER agonist in vitro and it can interfere with the normal function of human ER.
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Ácidos Ftálicos , Receptores de Estrógenos , Compuestos de Bifenilo , Dibutil Ftalato , Humanos , Simulación del Acoplamiento Molecular , Ácidos Ftálicos/toxicidad , Receptores de Estrógenos/genéticaRESUMEN
The core@shell structure dimension of the Pd-based nanocrystals deeply impacts their catalytic properties for C1 and C2 alcohol oxidation reactions. However, the precise simultaneous control on the synthesis of core@shell nanocrystals with different shell dimensions is difficult, and most synthesis on Pd-based core@shell nanocatalysts involves the surfactants participation by multiple steps, thus leads to limited catalytic properties. Herein, for the first time, a facile one-step surfactant-free strategy is developed for shell dimension reconstruction of PdAu@Pd core@shell nanocrystals by altering volume ratios of mixed solvents. The Pd-based sunflower-like (SL) and coral grass-like (CGL) nanocrystals are obtained with different 2D hexagonal nanosheet assembles and 3D network shells, respectively. Benefitting from the clean surface shell of 2D ultrathin nanosheets structure, high atom utilization efficiency, and robust electronic effect. The PdAu@Pd SL achieves the ascendant methanol/ethanol/ethylene glycol oxidation reaction (MOR/EOR/EGOR) activities, much higher than Pd/C catalysts, as well as the improved antipoisoning ability. Notably, this one-step construction shell dimension of PdAu@Pd core@shell catalysts not only provide a significant reference for the improvement of surfactant-free synthetic routes, but also shed light on the advanced engineering on shell dimensions in core@shell nanostructures for electrocatalysis and so forth.
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Nanopartículas , Paladio , Catálisis , Etanol , SolventesRESUMEN
Tembusu virus (TMUV) is a flavivirus responsible for panzootic outbreaks of severe egg-drop and fatal encephalitis of domestic waterfowl in China. Although TMUV can be attenuated by in vitro passaging, experimental evidence supporting the role of specific genetic changes in virulence attenuation is currently lacking. Here, we performed site-directed mutagenesis on five envelope (E) protein amino acid residues in accordance with the attenuated TMUV generated in our recent study. Our results showed that the Thr-to-Lys mutation of residue 367 in E protein (E367) plays a predominant role in viral cell adaptation and virulence attenuation in ducks compared with mutations in other residues. We further demonstrated that the positively charged basic amino acid substitution at E367 enhanced the viral binding affinity for glycosaminoglycans (GAGs) and reduced viremia levels and the efficiency of replication in major target organs in subcutaneously inoculated ducks. Interestingly, the T367K mutation increased viral neutralization sensitivity to the early immune sera. Together, our findings provide the first evidence that a basic amino acid substitution at E367 strongly impacts the in vitro and in vivo infection of TMUV.IMPORTANCE Outbreaks of Tembusu virus (TMUV) infection have caused huge economic losses in the production of domestic waterfowl since the virus was first recognized in China in 2010. To control TMUV infection, a live-attenuated vaccine candidate of TMUV was developed in our previous study, but the mechanisms of virulence attenuation are not fully understood. Here, we found that the Thr-to-Lys substitution at E367 is a crucial determinant of TMUV virulence attenuation in ducks. We demonstrated that the T367K mutation attenuates TMUV through reducing viral replication in the blood, brain, heart (ducklings), and ovaries. These data provide new insights into understanding the pathogenesis of TMUV and the rational development of novel TMUV vaccines.
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Sustitución de Aminoácidos , Infecciones por Flavivirus/inmunología , Infecciones por Flavivirus/virología , Flavivirus/genética , Proteínas del Envoltorio Viral/genética , Sustitución de Aminoácidos/inmunología , Animales , Anticuerpos Neutralizantes , Línea Celular , China/epidemiología , Patos/virología , Femenino , Infecciones por Flavivirus/epidemiología , Infecciones por Flavivirus/patología , Mutagénesis Sitio-Dirigida , Mutación , Enfermedades de las Aves de Corral/inmunología , Enfermedades de las Aves de Corral/mortalidad , Enfermedades de las Aves de Corral/patología , Enfermedades de las Aves de Corral/virología , Carga Viral , Virulencia , Replicación ViralRESUMEN
Pt-based catalysts with core@shell structures are widely used in alcohol oxidations due to their excellent catalytic performance. In this work, we synthesized a series of core@shell PtAuAg@PtAg hollow nanodendrites (HNDs) with different compositions by a simple seed-mediated method. The PtAuAg@PtAg HNDs with a hollow core and dendritic shell exhibit excellent catalytic performance for ethylene glycol oxidation reaction (EGOR) and methanol oxidation reaction (MOR). Among these, Pt38Au29Ag33 HNDs have the highest mass activity (12364.0 mA mgPt-1/3278.0 mA mgPt-1) for EGOR and MOR, which is 4.2 times and 5.3 times higher than that of commercial Pt/C (2941.0 mA mgPt-1/617.6 mA mgPt-1), respectively. More importantly, after successive cyclic voltammetry tests, the retained mass activities of Pt38Au29Ag33 HNDs are 3913.8 mA mgPt-1 and 348.3 mA mgPt-1, which are much higher than that of commercial Pt/C as well. The excellent catalytic performance of PtAuAg@PtAg HNDs can be attributed to the structure of HNDs, which can greatly increase the surface area and active sites, as well as the electronic and synergistic effects among Pt, Au, and Ag. This research may provide new ideas for the development of high-efficiency hollow catalytic materials for EGOR and MOR.
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In search of new environmentally friendly and effective antifungal agents, a series of 4-aminoquinolines bearing a 1,3-benzodioxole moiety were prepared and their structures were fully elucidated by spectroscopic analyses. The antifungal activities of all the target compounds against five phytopathogenic fungi were evaluated inâ vitro. The results revealed that most of the newly synthesized compounds exhibited obvious inhibitory activities at the concentration of 50â µg/mL. Among them, 6-(furan-2-yl)-N-(4-methylphenyl)-2H-[1,3]dioxolo[4,5-g]quinolin-8-amine hydrochloride (7m) displayed more promising antifungal potency with EC50 values of 10.3 and 14.0â µg/mL against C. lunata and A. alternate, respectively. Particularly, the EC50 value of 7m against C. lunata was 7.3-fold as potent as the standard azoxystrobin. There were some significant morphological alterations in the mycelia of C. lunata when treated with 7m at 50â µg/mL. Additionally, the preliminary structure-activity relationships (SARs) were also discussed. Thus, this study suggests that 4-aminoquinolines bearing a 1,3-benzodioxole moiety are interesting scaffolds for the development of novel antifungal agents.
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Aminoquinolinas/farmacología , Antifúngicos/farmacología , Dioxoles/farmacología , Hongos/efectos de los fármacos , Aminoquinolinas/síntesis química , Aminoquinolinas/química , Antifúngicos/síntesis química , Antifúngicos/química , Dioxoles/química , Relación Dosis-Respuesta a Droga , Pruebas de Sensibilidad Microbiana , Estructura MolecularRESUMEN
OBJECTIVE: To explore the clinical diagnostic application of invasive cardiopulmonary exercise test (iCPET) in patients with unexplained dyspnea. METHODS: A retrospective analysis was conducted, covering patients with a chief complaint of exertional dyspnea between May 5, 2017 and October 1, 2020. Right cardiac catheterization examination was performed on patients whose cause had not been identified through routine examination, and further iCPET was performed on patients if no clear etiology was identified through right cardiac catheterization. According to the results and the diagnostic criteria of iCPET, patients showing no obvious abnormalities in the right cardiac catheterization examination were divided into four subgroups: exercise-induced pulmonary arterial hypertension (eiPAH), exercise-induced heart failure with preserved ejection fraction (eiHFpEF), preload failure, and oxidative myopathy. By comparing the lab test, echocardiography, right heart catheter and iCPET peak exercise data of the subgroups, the disease distribution and exercise hemodynamic characteristics of patients with unexplained dyspnea examined by iCPET were described. RESULTS: Of the 1 046 patients with exertional dyspnea, 771 were diagnosed with routine examination, while among the remaining 275 patients, 131 (47.6%) were diagnosed with right cardiac catheterization and 144 (52.4%) showed no clear etiology after routine examination and right cardiac catheterization. Of these 144 patients, 49 (34.0%) received iCPET with a median exercise time of 375 s. A total of 47 patients completed the examination, with a male-to-female ratio of 0.27â¶1 and an average age of (47.9±14.4) years old. Among the 47 patients, 76.6% (36/47) aged between 20 and 59 and 78.7% (36/47) lived in urban areas. The preload failure group ( n=27) showed low right atrium pressure at peak exercise intensity. The eiHFpEF group ( n=9) showed high wedge pressure of pulmonary capillaries at peak of exercise intensity. The eiPAH group ( n=8) showed high average pulmonary artery pressure at peak exercise intensity. The oxidative myopathy group ( n=3) was characterized by impairment of tissue uptake and/or utilization of oxygen during exercise. According to the comparison among the three subgroups of the preload failure, eiHFpEF and eiPAH, the eiPAH group had the highest blood K + level in routine examination, while the preload failure group had the lowest blood K + level ( P=0.014). The iCPET of the three subgroups showed statistically significant ( P=0.001) difference in right atrial pressure increase during exercise. Among the three, the eiHFpEF group had the highest increase and the preload failure group had the lowest increase. Conclusion ãIn unexplained dyspnea patients showing no abnormal results in right cardiac catheterization examination, the main cause was preload failure, which manifested as low right atrial pressure at peak exercise intensity. The study showed that iCPET was of important value for dyspnea cases when the cause of the condition was not revealed with right cardiac catheterization.
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Prueba de Esfuerzo , Insuficiencia Cardíaca , Adulto , Cateterismo Cardíaco , Disnea/etiología , Tolerancia al Ejercicio , Femenino , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Presión Esfenoidal Pulmonar , Estudios RetrospectivosRESUMEN
The rapid analysis of stilbene estrogens is crucially important in the environment, food and health sectors, but quantitation of lower detection limit for stilbene estrogens persists as a severe challenge. We herein described a homologous and sensitive fluorescence polarization (FP) assay based on estrogen receptor α ligand binding domain (ER-LBD) to monitor stilbene estrogens in milk. Under optimal conditions, the half maximal inhibitory concentrations (IC50) of the FP assay were 9.27 nM, 12.94 nM, and 22.38 nM for hexestrol, dienestrol and diethylstilbestrol, respectively. And the corresponding limits of detection (LOD) values were 2.94 nM, 2.89 nM, and 3.12 nM. Finally, the assay was applied to determine the stilbenes in milk samples where the mean recoveries ranged from 95.76% to 112.78% and the coefficients of variation (CV) below 12.00%. Furtherly, we have focused our study on high cross-reactivity phenomena by using two in silico approaches, including molecular docking analysis and topology analysis. Overall, docking results show that several residues in the hydrophobic pocket produce hydrophobic interactions with the tested drug molecules, which contribute to the stability of their binding. In this paper, we conclude that the FP method is suitable for the rapid detection of stilbenes in milk samples, requiring no expensive analytical equipment or time-consuming sample preparation. This work offers a practical approach that applies bioscience technology in food safety testing and improves analytical speed and laboratory efficiency.
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Dietilestilbestrol/análisis , Dietilestilbestrol/química , Leche/química , Animales , Unión Competitiva , Relación Dosis-Respuesta a Droga , Receptor alfa de Estrógeno/química , Receptor alfa de Estrógeno/metabolismo , Enlace de Hidrógeno , Concentración 50 Inhibidora , Cinética , Ligandos , Modelos Moleculares , Conformación Molecular , Unión ProteicaRESUMEN
BACKGROUND: Identify genes probably associated with chronic heart failure and predict potential target genes for dilated cardiomyopathy using bioinformatics analyses. METHODS: Gene expression profiles (series number GSE3585 and GSE42955) of cardiomyopathy patients and healthy controls were downloaded from the Expression Omnibus Gene (GEO) database. Differential expression of genes (DEGS) between the two groups of total 14 cardiomyopathy patients and 10 healthy controls were subsequently identified by limma package of R. Database for Annotation, Visualization, and Integrated Discovery (DAVID Tool), which is an analysis of enriched biological processes. Search Tool for the Retrieval Interacting Genes (STRING) was used as well for the analysis of protein-protein interaction network (PPI). Prediction of the potential drugs was suggested based on the preliminarily identified genes using Connectivity Map (CMap). RESULTS: Eighty-nine DEGs were identified (57 up-regulated and 32 down-regulated). The most enrichment Gene Ontology (GO) terms (P < 0.05) contain genes involved in extracellular matrix (ECM) and biological adhesion signal pathways (P < 0.05, ES > 1.5) such as ECM-receptors, focal adhesion and transforming growth factor beta (TGF-ß), etc. Fifty-one differentially expressed genes were found to encode interacting proteins. Eleven key genes along with related transcription factors were identified including CTGF, POSTN, CORIN, FIGF, etc. CONCLUSION: Bioinformatics-based analyses reveal the targeted genes probably associated with cardiomyopathy, which provide clues for pharmacological therapies aiming at the targets.
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Cardiomiopatía Dilatada/genética , Cardiomiopatía Dilatada/fisiopatología , Transcriptoma , Biología Computacional , Perfilación de la Expresión Génica , HumanosRESUMEN
The binding interactions of bisphenol A (BPA) and its halogenated derivatives (halogenated BPAs) to human estrogen receptor α ligand binding domain (hERα-LBD) was investigated using a combined in vitro and in silico approach. First, the recombinant hERα-LBD was prepared as a soluble protein in Escherichia coli BL21(DE3)pLysS. A native fluorescent phytoestrogen, coumestrol, was employed as tracer for the fluorescence polarization assay. The results of the in vitro binding assay showed that bisphenol compounds could bind to hERα-LBD as the affinity ligands. All the tested halogenated BPAs exhibited weaker receptor binding than BPA, which might be explained by the steric effect of substituents. Molecular docking studies elucidated that the halogenated BPAs adopted different conformations in the flexible hydrophobic ligand binding pocket (LBP), which is mainly dependent on their distinct halogenation patterns. The compounds with halogen substituents on the phenolic rings and on the bridging alkyl moiety acted as agonists and antagonists for hERα, respectively. Interestingly, all the compounds in the agonist conformation of hERα formed a hydrogen bond with His524, while the compounds in the antagonist conformation formed a hydrogen bond with Thr347. These docking results suggested a pivotal role of His524/Thr347 in maintaining the hERα structure in the biologically active agonist/antagonist conformation. Comparison of the calculated binding energies vs. experimental binding affinities yielded a good correlation, which might be applicable for the structure-based design of novel bisphenol compounds with reduced toxicities and for environmental risk assessment. In addition, based on hERα-LBD as a recognition element, the proposed fluorescence polarization assay may offer an alternative to chromatographic techniques for the multi-residue determination of bisphenol compounds.