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1.
J Phys Chem A ; 128(23): 4750-4760, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38832647

RESUMO

The interactions between a magnetic tip and local spin impurities initiate unconventional Kondo phenomena, such as asymmetric suppression or even splitting of the Kondo peak. However, a lack of realistic theoretical models and comprehensive explanations for this phenomenon persists due to the complexity of the interactions. This research employs a joint method of density functional theory (DFT) and hierarchical equation of motion (HEOM) to simulate and contrast the modulation of the spin state and Kondo behavior in the Fe/Cu(100) system with two distinct magnetic tips. A cobalt tip, possessing a larger magnetic moment, incites greater atomic displacement of the iron atom, more notable alterations in electronic structure, and enhanced charge transfer with the environment compared with the control process utilizing a nickel tip. Furthermore, the Kondo resonance undergoes asymmetric splitting as a result of the ferromagnetic correlation between the iron atom and the magnetic tip. The Co tip's higher spin polarization results in a wider spacing between the splitting peaks. This investigation underscores the precision of the DFT + HEOM approach in predicting complex quantum phenomena and explaining the underlying physical principles. This provides valuable theoretical support for developing more sophisticated quantum regulation experiments.

2.
BMC Neurol ; 23(1): 428, 2023 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-38042771

RESUMO

BACKGROUND: Paranasal sinus angiosarcoma is an uncommon malignancy, with only a few reported cases worldwide. Although it exhibits multiple symptoms, facial paralysis has not been previously documented as a noticeable presentation. CASE PRESENTATION: In this case, we report a 40-year-old male who presented with facial numbness and pain for one month, weakness of his facial muscles for 15 days, and recurrent right epistaxis for 1 year. He had a history of nasal inflammatory polyps with chronic sinusitis. Computed tomography and magnetic resonance imaging showed space-occupying lesions in the right nasal cavity and maxillary sinus, with bone destruction occurring in the sinus wall and turbinate. This patient then underwent endoscopic surgery. According to the histopathological and immunohistochemical results, he was eventually diagnosed with paranasal sinus angiosarcoma in April 2021. To date, this patient has not initiated any radiotherapy or chemotherapy and has survived with lymphatic metastasis for at least 3 years. CONCLUSIONS: This manuscript suggests that paranasal sinus angiosarcoma can present with facial paralysis. Moreover, pathological and immunohistochemical tests are still vital for diagnosing paranasal sinus angiosarcoma and differential diagnosis. Additionally, regular follow-up is crucial for patients with paranasal sinus angiosarcoma, enabling monitoring of recurrence, metastasis, and recovery while contributing valuable clinical data to understanding this rare disease and associated research endeavours.


Assuntos
Paralisia Facial , Hemangiossarcoma , Masculino , Humanos , Adulto , Hemangiossarcoma/diagnóstico , Hemangiossarcoma/diagnóstico por imagem , Paralisia Facial/etiologia , Seio Maxilar/diagnóstico por imagem , Seio Maxilar/patologia , Cavidade Nasal/patologia , Epistaxe/patologia
3.
Biomed Chromatogr ; 36(11): e5471, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35916119

RESUMO

A rapid and sensitive UHPLC-MS/MS method was developed and fully validated for the quantification of verinurad in rat plasma. Lesinurad was used as an internal standard (IS), and simple protein precipitation was utilized to prepare the analytes from the matrix. Chromatographic separation was carried out on a Zorbax SB C18 column. The mobile phase consisted of water with 0.1% formic acid (A) and acetonitrile with 0.1% formic acid (B) at a flow rate of 0.3 mL/min. The short run time of 4 min made it possible to analyze more than 300 samples per day. The ion transitions were quantified in negative mode with multiple reaction monitoring (MRM) transitions of 347.1 â†’ 261.1 for verinurad and 404.2 â†’ 178.9 for the IS. The validated linear ranges of verinurad were 10-5000 ng/mL in rat plasma. The validated UHPLC-MS/MS method was further applied to the pharmacokinetic study of verinurad in rat plasma after intragastric (2 mg/kg) and intravenous (1 mg/kg) administrations. The pharmacokinetic study revealed that verinurad showed high clearance and high bioavailability (78.1%). To the best of our knowledge, this is the first report of the bioavailability study of verinurad.


Assuntos
Espectrometria de Massas em Tandem , Água , Acetonitrilas , Animais , Disponibilidade Biológica , Cromatografia Líquida de Alta Pressão/métodos , Formiatos , Naftalenos , Propionatos , Piridinas , Ratos , Ratos Sprague-Dawley , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem/métodos
4.
Cereb Cortex ; 23(1): 71-9, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22250289

RESUMO

Regulated growth and branching of dendritic processes is critical for the establishment of neuronal circuitry and normal brain functions. Rho family GTPases, including RhoA, Rac1, and Cdc42, play a prominent role in dendritic development. RhoA inhibits dendritic branching and growth, whereas Rac1/Cdc42 does the opposite. It has been suggested that the activity of RhoA must be kept low to allow dendritic growth. However, how neurons restrict the activation of RhoA for proper dendritic development is not clear. In the present study, we undertook a comprehensive loss-of-function analysis of putative RhoA GTPase-activating proteins (RhoA GAPs) in the cortical neurons. The expression of 16 RhoA GAPs was detected in the developing rat brain, and RNA interference experiments suggest that 2 of them, Myo9b and RICS, are critical regulators of dendritic morphogenesis. Knockdown of either Myo9b or RICS in cultured cortical neurons or developing cortex resulted in decreased dendrite length and number. Inhibition of RhoA/ROCK signaling restores the defects of dendritic morphology induced by knockdown of Myo9b or RICS. These data demonstrate that Myo9b and RICS repress RhoA/Rock signaling and modulate dendritic morphogenesis in cortical neurons, providing evidence for critical physiological function of RhoA GAPs in regulation of dendritic development.


Assuntos
Córtex Cerebral/citologia , Córtex Cerebral/metabolismo , Dendritos/metabolismo , Dendritos/ultraestrutura , Miosinas/metabolismo , Quinases Associadas a rho/metabolismo , Proteína rhoA de Ligação ao GTP/metabolismo , Animais , Tamanho Celular , Células Cultivadas , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/fisiologia , Distribuição Tecidual
5.
RSC Adv ; 14(1): 353-363, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38173589

RESUMO

The elucidation of carbonate crystal growth mechanisms contributes to a deeper comprehension of microbial-induced carbonate precipitation processes. In this research, the Curvibacter lanceolatus HJ-1 strain, well-known for its proficiency in inducing carbonate mineralization, was employed to trigger the formation of concave-type carbonate minerals. The study meticulously tracked the temporal alterations in the culture solution and conducted comprehensive analyses of the precipitated minerals' mineralogy and morphology using advanced techniques such as X-ray diffraction, scanning electron microscopy, focused ion beam, and transmission electron microscopy. The findings unequivocally demonstrate that concave-type carbonate minerals are meticulously templated by bacterial biofilms and employ calcified bacteria as their fundamental structural components. The precise morphological evolution pathway can be delineated as follows: initiation with the formation of bacterial biofilms, followed by the aggregation of calcified bacterial clusters, ultimately leading to the emergence of concave-type minerals characterized by disc-shaped, sunflower-shaped, and spherical morphologies.

6.
Behav Sci (Basel) ; 13(1)2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36661635

RESUMO

To reduce the impact of rating bias and popularity bias in recommender system, and make the recommender system reach a balance between recommendation utility and debias effect at the same time, we propose a bi-process debiasing recommendation model based on matrix factorization. Firstly, considering the problem that the user's ratings are affected by the herd mentality, which leads to a consistency between the rating and the selection of rating items, resulting in the power-law distribution, the k-times parabolic fuzzy distribution was used to fuse the user's age to redistribute the ratings. Secondly, the loss function is optimized by the continuously increasing flow and popularity of items. Finally, user emotion and item popularity are combined to construct user psychological tendency, which is divided into three levels: strong, medium and weak, and different levels are given different weights. To verify the performance of the model, the experimental results on real datasets show that the model proposed in this paper not only effectively reduces the recommendation bias but also ensures the recommendation utility.

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