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1.
Nat Immunol ; 22(9): 1127-1139, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34413521

RESUMEN

Follicular helper T (TFH) cells are a specialized subset of CD4+ T cells that essentially support germinal center responses where high-affinity and long-lived humoral immunity is generated. The regulation of TFH cell survival remains unclear. Here we report that TFH cells show intensified lipid peroxidation and altered mitochondrial morphology, resembling the features of ferroptosis, a form of programmed cell death that is driven by iron-dependent accumulation of lipid peroxidation. Glutathione peroxidase 4 (GPX4) is the major lipid peroxidation scavenger and is necessary for TFH cell survival. The deletion of GPX4 in T cells selectively abrogated TFH cells and germinal center responses in immunized mice. Selenium supplementation enhanced GPX4 expression in T cells, increased TFH cell numbers and promoted antibody responses in immunized mice and young adults after influenza vaccination. Our findings reveal the central role of the selenium-GPX4-ferroptosis axis in regulating TFH homeostasis, which can be targeted to enhance TFH cell function in infection and following vaccination.


Asunto(s)
Ferroptosis/fisiología , Fosfolípido Hidroperóxido Glutatión Peroxidasa/metabolismo , Selenio/farmacología , Células T Auxiliares Foliculares/fisiología , Adolescente , Adulto , Animales , Supervivencia Celular/inmunología , Niño , Femenino , Centro Germinal/citología , Centro Germinal/inmunología , Homeostasis/efectos de los fármacos , Homeostasis/genética , Humanos , Inmunidad Humoral/inmunología , Vacunas contra la Influenza/inmunología , Peroxidación de Lípido/fisiología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Mitocondrias/fisiología , Ovalbúmina , Células T Auxiliares Foliculares/inmunología , Vacunación , Adulto Joven
4.
Proc Natl Acad Sci U S A ; 119(42): e2203702119, 2022 10 18.
Artículo en Inglés | MEDLINE | ID: mdl-36215480

RESUMEN

The full activation process of G protein-coupled receptor (GPCR) plays an important role in cellular signal transduction. However, it remains challenging to simulate the whole process in which the GPCR is recognized and activated by a ligand and then couples to the G protein on a reasonable simulation timescale. Here, we developed a molecular dynamics (MD) approach named supervised (Su) Gaussian accelerated MD (GaMD) by incorporating a tabu-like supervision algorithm into a standard GaMD simulation. By using this Su-GaMD method, from the active and inactive structure of adenosine A1 receptor (A1R), we successfully revealed the full activation mechanism of A1R, including adenosine (Ado)-A1R recognition, preactivation of A1R, and A1R-G protein recognition, in hundreds of nanoseconds of simulations. The binding of Ado to the extracellular side of A1R initiates conformational changes and the preactivation of A1R. In turn, the binding of Gi2 to the intracellular side of A1R causes a decrease in the volume of the extracellular orthosteric site and stabilizes the binding of Ado to A1R. Su-GaMD could be a useful tool to reconstruct or even predict ligand-protein and protein-protein recognition pathways on a short timescale. The intermediate states revealed in this study could provide more detailed complementary structural characterizations to facilitate the drug design of A1R in the future.


Asunto(s)
Simulación de Dinámica Molecular , Receptores Purinérgicos P1 , Adenosina , Proteínas de Unión al GTP/metabolismo , Ligandos , Receptor de Adenosina A1/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Receptores Purinérgicos P1/metabolismo , Termodinámica
5.
J Lipid Res ; 65(10): 100634, 2024 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-39182609

RESUMEN

Human genetic studies show that loss of function mutations in 17-Beta hydroxysteroid dehydrogenase (HSD17ß13) are associated with protection from non-alcoholic steatohepatitis (NASH). As a result, therapies that reduce HSD17ß13 are being pursued for the treatment of NASH. However, inconsistent effects on steatosis, inflammation, and fibrosis pathogenesis have been reported in murine Hsd17b13 knockdown or knockout models. To clarify whether murine Hsd17b13 loss regulates liver damage and fibrosis, we characterized Hsd17b13 knockout mice subjected to pro-NASH diets or pro-inflammatory chemical-induced liver injury. There were no effects of Hsd17b13 loss on liver injury, inflammation, fibrosis, or lipids after 28 weeks on the Gubra-Amylin NASH (GAN) diet or 12 weeks on a 45% choline-deficient high-fat diet (CDAHFD). However, AAV-mediated re-expression of murine Hsd17b13 in KO mice increased liver macrophage abundance in both sexes fed the 45% CDAHFD. In contrast, there was a modest reduction in liver fibrosis, but not lipids or inflammation within Hsd17b13 null female, but not male, mice after 12 weeks of a 60% CDAHFD compared to WT littermates. Fibrosis and the abundance of liver macrophages were increased in Hsd17b13 KO females upon adenoviral re-expression of mouse HSD17ß13, but this was not reflected in inflammatory markers. Additionally, we found minimal differences in liver injury, lipids, or inflammatory and fibrotic markers 48 h after acute CCl4 exposure. In summary, murine Hsd17b13 loss has modest diet- and sex-specific effects on liver fibrosis which contrasts with human genetic studies. This suggests a disconnect between the biological function of HSD17ß13 in mice and humans.

6.
BMC Genomics ; 25(1): 68, 2024 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-38233753

RESUMEN

BACKGROUND: Costaceae, commonly known as the spiral ginger family, consists of approximately 120 species distributed in the tropical regions of South America, Africa, and Southeast Asia, of which some species have important ornamental, medicinal and ecological values. Previous studies on the phylogenetic and taxonomic of Costaceae by using nuclear internal transcribed spacer (ITS) and chloroplast genome fragments data had low resolutions. Additionally, the structures, variations and molecular evolution of complete chloroplast genomes in Costaceae still remain unclear. Herein, a total of 13 complete chloroplast genomes of Costaceae including 8 newly sequenced and 5 from the NCBI GenBank database, representing all three distribution regions of this family, were comprehensively analyzed for comparative genomics and phylogenetic relationships. RESULT: The 13 complete chloroplast genomes of Costaceae possessed typical quadripartite structures with lengths from 166,360 to 168,966 bp, comprising a large single copy (LSC, 90,802 - 92,189 bp), a small single copy (SSC, 18,363 - 20,124 bp) and a pair of inverted repeats (IRs, 27,982 - 29,203 bp). These genomes coded 111 - 113 different genes, including 79 protein-coding genes, 4 rRNA genes and 28 - 30 tRNAs genes. The gene orders, gene contents, amino acid frequencies and codon usage within Costaceae were highly conservative, but several variations in intron loss, long repeats, simple sequence repeats (SSRs) and gene expansion on the IR/SC boundaries were also found among these 13 genomes. Comparative genomics within Costaceae identified five highly divergent regions including ndhF, ycf1-D2, ccsA-ndhD, rps15-ycf1-D2 and rpl16-exon2-rpl16-exon1. Five combined DNA regions (ycf1-D2 + ndhF, ccsA-ndhD + rps15-ycf1-D2, rps15-ycf1-D2 + rpl16-exon2-rpl16-exon1, ccsA-ndhD + rpl16-exon2-rpl16-exon1, and ccsA-ndhD + rps15-ycf1-D2 + rpl16-exon2-rpl16-exon1) could be used as potential markers for future phylogenetic analyses and species identification in Costaceae. Positive selection was found in eight protein-coding genes, including cemA, clpP, ndhA, ndhF, petB, psbD, rps12 and ycf1. Maximum likelihood and Bayesian phylogenetic trees using chloroplast genome sequences consistently revealed identical tree topologies with high supports between species of Costaceae. Three clades were divided within Costaceae, including the Asian clade, Costus clade and South American clade. Tapeinochilos was a sister of Hellenia, and Parahellenia was a sister to the cluster of Tapeinochilos + Hellenia with strong support in the Asian clade. The results of molecular dating showed that the crown age of Costaceae was about 30.5 Mya (95% HPD: 14.9 - 49.3 Mya), and then started to diverge into the Costus clade and Asian clade around 23.8 Mya (95% HPD: 10.1 - 41.5 Mya). The Asian clade diverged into Hellenia and Parahellenia at approximately 10.7 Mya (95% HPD: 3.5 - 25.1 Mya). CONCLUSION: The complete chloroplast genomes can resolve the phylogenetic relationships of Costaceae and provide new insights into genome structures, variations and evolution. The identified DNA divergent regions would be useful for species identification and phylogenetic inference in Costaceae.


Asunto(s)
Genoma del Cloroplasto , Filogenia , Teorema de Bayes , Genómica/métodos , ADN
7.
Anal Chem ; 96(8): 3402-3408, 2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38355418

RESUMEN

l-Cysteine, distinguished by its possession of reactive sulfhydryl groups within its molecular structure, plays a significant role in both biological systems and the pharmaceutical industry. It stands not only as a natural component integral to the constitution of glutathione but also as the principal precursor for the synthesis of l-cystine through an oxidation reaction. This study endeavors to introduce a novel approach to l-cysteine analysis, capitalizing on its optical activity, whereby an optical rotation detection system grounded in the principles of quantum weak measurement is proffered. The optical rotation angle corresponding to the concentration of chiral solutions can be accurately ascertained through spectral analysis. In practical implementation, a chiral sensing system, boasting a sensitivity of 372 nm/rad, was meticulously constructed, leveraging the concept of weak value amplification. Then, the real-time monitoring of chemical reactions involving l-cysteine and dimethyl sulfoxide was performed. Under the specific experimental conditions outlined in this investigation, it was observed that the oxidation process culminated within approximately 12 h. The application of weak measurement-based chiral sensors holds immense potential, providing robust technical support for real-time monitoring in fields such as chiral analysis and the synthesis of chiral pharmaceutical compounds.

8.
Plant Cell Environ ; 47(3): 871-884, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38164043

RESUMEN

Symbiotic nitrogen fixation (SNF) is a crucial process for nitrogen geochemical cycling and plant-microbe interactions. Water-soluble humic acid (WSHM), an active component of soil humus, has been shown to promote SNF in the legume-rhizobial symbiosis, but its molecular mechanism remains largely unknown. To reveal the SNF-promoting mechanism, we conducted transcriptomic analysis on soybean treated with WSHM. Our findings revealed that up- and downregulated differentially expressed genes (DEGs) were mainly involved in plant cell-wall/membrane formation and plant defence/immunity in the early stage, while the late stage was marked by the flavonoid synthesis and ethylene biosynthetic process. Further study on representative DEGs showed that WSHM could inhibit GmBAK1d-mediated immunity and BR signalling, thereby promoting rhizobial colonisation, infection, and nodulation, while not favoring pathogenic bacteria colonisation on the host plant. Additionally, we also found that the ethylene pathway is necessary for promoting the soybean nodulation by WSHM. This study not only provides a significant advance in our understanding of the molecular mechanism of WSHM in promoting SNF, but also provides evidence of the beneficial interactions among the biostimulator, host plant, and soil microbes, which have not been previously reported.


Asunto(s)
Glycine max , Rhizobium , Nodulación de la Raíz de la Planta , Sustancias Húmicas , Fijación del Nitrógeno , Etilenos/metabolismo , Inmunidad de la Planta , Simbiosis , Nódulos de las Raíces de las Plantas/microbiología
9.
BMC Cancer ; 24(1): 575, 2024 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-38724921

RESUMEN

OBJECTIVE: To identify the risk factors of cervical high-grade squamous intraepithelial lesion(HSIL) complicated with occult cervical cancer and standardize the management of initial treatment for HSIL. METHOD: The clinical data of patients who underwent total hysterectomy directly due to HSIL in the obstetrics and gynecology department of two tertiary hospitals and three secondary hospitals from 2018 to 2023 were collected. Their general characteristics, pathological parameters and survival status were analyzed. Logistic regression model was used to analyze the correlation between clinical parameters and postoperative pathological upgrading. RESULT: 1. Among the 314 patients with HSIL who underwent total hysterectomy directly, 73.2% were from primary hospitals. 2. 25 patients (7.9%) were pathologically upgraded to cervical cancer, all of which were early invasive cancer. 3. Up to now, there was no recurrence or death in the 25 patients with early-stage invasive cancer, and the median follow-up period was 21 months(range 2-59 months). 4. Glandular involvement(OR 3.968; 95%CI 1.244-12.662) and lesion range ≥ 3 quadrants (OR 6.527; 95% CI 1.78-23.931), HPV 16/18 infection (OR 5.382; 95%CI 1.947-14.872), TCT ≥ ASC-H (OR 4.719; 95%CI 1.892-11.766) were independent risk factors that affected the upgrading of postoperative pathology. 5. The area under the curve (AUC) calculated by the Logistic regression model was 0.840, indicating that the predictive value was good. CONCLUSION: There is a risk of occult cervical cancer in patients with HSIL. Glandular involvement, Lesion range ≥ 3 quadrants, HPV 16/18 infection and TCT ≥ ASC-H are independent risk factors for HSIL combined with occult cervical cancer. The prognosis of biopsy-proved HSIL patients who underwent extrafascial hysterectomy and unexpected early invasive cancer was later identified on specimen may be good.


Asunto(s)
Histerectomía , Neoplasias del Cuello Uterino , Humanos , Femenino , Histerectomía/métodos , Estudios Retrospectivos , Persona de Mediana Edad , Neoplasias del Cuello Uterino/cirugía , Neoplasias del Cuello Uterino/patología , Adulto , Factores de Riesgo , Anciano , Lesiones Intraepiteliales Escamosas de Cuello Uterino/patología , Lesiones Intraepiteliales Escamosas de Cuello Uterino/cirugía , Lesiones Intraepiteliales Escamosas/patología , Lesiones Intraepiteliales Escamosas/cirugía , Infecciones por Papillomavirus/complicaciones , Infecciones por Papillomavirus/virología , Infecciones por Papillomavirus/patología , Displasia del Cuello del Útero/cirugía , Displasia del Cuello del Útero/patología , Clasificación del Tumor
10.
FEMS Yeast Res ; 242024 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-38592962

RESUMEN

How mutations in mitochondrial electron transport chain (ETC) proteins impact the cell cycle of Candida albicans was investigated in this study. Using genetic null mutants targeting ETC complexes I (CI), III (CIII), and IV (CIV), the cell cycle stages (G0/G1, S phase, and G2/M) were analyzed via fluorescence-activated cell sorting (FACS). Four CI null mutants exhibited distinct alterations, including extended S phase, shortened G2/M population, and a reduction in cells size exceeding 10 µM. Conversely, CIII mutants showed an increased population in G1/G0 phase. Among four CI mutants, ndh51Δ/Δ and goa1Δ/Δ displayed aberrant cell cycle patterns correlated with previously reported cAMP/PKA downregulation. Specifically, nuo1Δ/Δ and nuo2Δ/Δ mutants exhibited increased transcription of RIM15, a central hub linking cell cycle with nutrient-dependent TOR1 and cAMP/PKA pathways and Snf1 aging pathway. These findings suggest that suppression of TOR1 and cAMP/PKA pathways or enhanced Snf1 disrupts cell cycle progression, influencing cell longevity and growth among CI mutants. Overall, our study highlights the intricate interplay between mitochondrial ETC, cell cycle, and signaling pathways.


Asunto(s)
Candida albicans , Mitocondrias , Candida albicans/fisiología , Fase S , Mitocondrias/metabolismo , Ciclo Celular , División Celular
11.
PLoS Biol ; 19(3): e3000957, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33720927

RESUMEN

A forward genetic screening approach identified orf19.2500 as a gene controlling Candida albicans biofilm dispersal and biofilm detachment. Three-dimensional (3D) protein modeling and bioinformatics revealed that orf19.2500 is a conserved mitochondrial protein, structurally similar to, but functionally diverged from, the squalene/phytoene synthases family. The C. albicans orf19.2500 is distinguished by 3 evolutionarily acquired stretches of amino acid inserts, absent from all other eukaryotes except a small number of ascomycete fungi. Biochemical assays showed that orf19.2500 is required for the assembly and activity of the NADH ubiquinone oxidoreductase Complex I (CI) of the respiratory electron transport chain (ETC) and was thereby named NDU1. NDU1 is essential for respiration and growth on alternative carbon sources, important for immune evasion, required for virulence in a mouse model of hematogenously disseminated candidiasis, and for potentiating resistance to antifungal drugs. Our study is the first report on a protein that sets the Candida-like fungi phylogenetically apart from all other eukaryotes, based solely on evolutionary "gain" of new amino acid inserts that are also the functional hub of the protein.


Asunto(s)
Biopelículas/crecimiento & desarrollo , Candida albicans/genética , Proteínas Mitocondriales/genética , Candida albicans/crecimiento & desarrollo , Biología Computacional/métodos , Proteínas Fúngicas/metabolismo , Regulación Fúngica de la Expresión Génica/genética , Genes Mitocondriales/genética , Genes Mitocondriales/fisiología , Proteínas Mitocondriales/metabolismo , Modelos Biológicos , Filogenia , Virulencia/genética
12.
Horm Metab Res ; 2024 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-38588699

RESUMEN

This study aims to establish a random forest model for detecting the severity of Graves Orbitopathy (GO) and identify significant classification factors. This is a hospital-based study of 199 patients with GO that were collected between December 2019 and February 2022. Clinical information was collected from medical records. The severity of GO can be categorized as mild, moderate-to-severe, and sight-threatening GO based on guidelines of the European Group on Graves' orbitopathy. A random forest model was constructed according to the risk factors of GO and the main ocular symptoms of patients to differentiate mild GO from severe GO and finally was compared with logistic regression analysis, Support Vector Machine (SVM), and Naive Bayes. A random forest model with 15 variables was constructed. Blurred vision, disease course, thyroid-stimulating hormone receptor antibodies, and age ranked high both in mini-decreased gini and mini decrease accuracy. The accuracy, positive predictive value, negative predictive value, and the F1 Score of the random forest model are 0.83, 0.82, 0.86, and 0.82, respectively. Compared to the three other models, our random forest model showed a more reliable performance based on AUC (0.85 vs. 0.83 vs. 0.80 vs. 0.76) and accuracy (0.83 vs. 0.78 vs. 0.77 vs. 0.70). In conclusion, this study shows the potential for applying a random forest model as a complementary tool to differentiate GO severity.

13.
Med Mycol ; 62(2)2024 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-38318638

RESUMEN

Chromoblastomycosis (CBM), a chronic, granulomatous, suppurative mycosis of the skin and subcutaneous tissue, is caused by several dematiaceous fungi. The formation of granulomas, tissue proliferation, and fibrosis in response to these pathogenic fungi is believed to be intricately linked to host immunity. To understand this complex interaction, we conducted a comprehensive analysis of immune cell infiltrates, neutrophil extracellular traps (NETs) formation, and the fibrosis mechanism in 20 CBM lesion biopsies using immunohistochemical and immunofluorescence staining methods. The results revealed a significant infiltration of mixed inflammatory cells in CBM granulomas, prominently featuring a substantial presence of Th2 cells and M2 macrophages. These cells appeared to contribute to the production of collagen I and III in the late fibrosis mechanism, as well as NETs formation. The abundance of Th2 cytokines may act as a factor promoting the bias of macrophage differentiation toward M2, which hinders efficient fungal clearance while accelerates the proliferation of fibrous tissue. Furthermore, the expression of IL-17 was noted to recruit neutrophils, facilitating subsequent NETs formation within CBM granulomas to impede the spread of sclerotic cells. Understanding of these immune mechanisms holds promise for identifying therapeutic targets for managing chronic granulomatous CBM.


Asunto(s)
Trampas Extracelulares , Animales , Neutrófilos , Fibrosis , Granuloma/veterinaria , Inmunidad
14.
AIDS Behav ; 2024 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-39292319

RESUMEN

Individually, the COVID-19 and HIV pandemics have differentially impacted minoritized groups due to the role of social determinants of health (SDoH) in the U.S. Little is known how the collision of these two pandemics may have exacerbated adverse health outcomes. We evaluated county-level SDoH and associations with hospitalization after a COVID-19 diagnosis among people with (PWH) and without HIV (PWOH) by racial/ethnic groups. We used the U.S. National COVID Cohort Collaborative (January 2020-November 2023), a nationally-sampled electronic health record repository, to identify adults who were diagnosed with COVID-19 with HIV (n = 22,491) and without HIV (n = 2,220,660). We aggregated SDoH measures at the county-level and categorized racial/ethnic groups as Non-Hispanic (NH) White, NH-Black, Hispanic/Latinx, NH-Asian and Pacific Islander (AAPI), and NH-American Indian or Alaskan Native (AIAN). To estimate associations of county-level SDoH with hospitalization after a COVID-19 diagnosis, we used multilevel, multivariable logistic regressions, calculating adjusted relative risks (aRR) with 95% confidence intervals (95% CI). COVID-19 related hospitalization occurred among 11% of PWH and 7% of PWOH, with the highest proportion among NH-Black PWH (15%). In evaluating county-level SDoH among PWH, we found higher average household size was associated with lower risk of COVID-19 related hospitalization across racial/ethnic groups. Higher mean commute time (aRR: 1.76; 95% CI 1.10-2.62) and higher proportion of adults without health insurance (aRR: 1.40; 95% CI 1.04-1.84) was associated with a higher risk of COVID-19 hospitalization among NH-Black PWH, however, NH-Black PWOH did not demonstrate these associations. Differences by race and ethnicity exist in associations of adverse county-level SDoH with COVID-19 outcomes among people with and without HIV in the U.S.

15.
Nicotine Tob Res ; 26(Supplement_1): S43-S48, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38366336

RESUMEN

INTRODUCTION: Instagram is a popular social networking platform for sharing photos with a large proportion of youth and young adult users. We aim to identify key features in anti-vaping Instagram image posts associated with high social media user engagement by artificial intelligence. AIMS AND METHODS: We collected 8972 anti-vaping Instagram image posts and hand-coded 2200 Instagram images to identify nine image features such as warning signs and person-shown vaping. We utilized a deep-learning model, the OpenAI: contrastive language-image pre-training with ViT-B/32 as the backbone and a 5-fold cross-validation model evaluation, to extract similar features from the Instagram image and further trained logistic regression models for multilabel classification. Latent Dirichlet Allocation model and Valence Aware Dictionary and sEntiment Reasoner were used to extract the topics and sentiment from the captions. Negative binomial regression models were applied to identify features associated with the likes and comments count of posts. RESULTS: Several features identified in anti-vaping Instagram image posts were significantly associated with high social media user engagement (likes or comments), such as educational warnings and warning signs. Instagram posts with captions about health risks associated with vaping received significantly more likes or comments than those about help quitting smoking or vaping. Compared to the model based on 2200 hand-coded Instagram image posts, more significant features have been identified from 8972 AI-labeled Instagram image posts. CONCLUSION: Features identified from anti-vaping Instagram image posts will provide a potentially effective way to communicate with the public about the health effects of e-cigarette use. IMPLICATIONS: Considering the increasing popularity of social media and the current vaping epidemic, especially among youth and young adults, it becomes necessary to understand e-cigarette-related content on social media. Although pro-vaping messages dominate social media, anti-vaping messages are limited and often have low user engagement. Using advanced deep-learning and statistical models, we identified several features in anti-vaping Instagram image posts significantly associated with high user engagement. Our findings provide a potential approach to effectively communicate with the public about the health risks of vaping to protect public health.


Asunto(s)
Aprendizaje Profundo , Sistemas Electrónicos de Liberación de Nicotina , Medios de Comunicación Sociales , Vapeo , Adulto Joven , Adolescente , Humanos , Inteligencia Artificial , Red Social
16.
Phys Chem Chem Phys ; 26(21): 15511-15518, 2024 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-38752450

RESUMEN

Covalent organic frameworks (COFs) are an emerging class of crystalline organic materials that have shown potential to be a new physical platform. In this work, a designed COF named AB-COF, which has novel enantiomorphic Kagome bands, is proposed and a feasible route to synthesize it is given. Via a combination of first-principles calculations and tight-binding analysis, we investigate the electronic structures and the phase interference of the COF. It becomes topologically nontrivial when doping one iodine atom in a unit cell. The Berry curvatures of the valence band (VB) and conduction band (CB) of the iodine-doped AB-COF show opposite values and different distributions. This provides an opportunity to study the new mechanism of circular dichroism from the different Berry curvatures of the VB and CB. Surprisingly, the circular-dichroism dissymmetry factor of AB-COF reaches a theoretical maximum value, and the oscillator strength data are in agreement with this result. When two iodine atoms are doped in a unit cell, the Berry curvatures of the VB and CB also have different values, but with more symmetry and similar distributions. This behavior enhances the circular dichroism with a wider range of dissymmetric absorption, and the circular dichroism dissymmetry factor also reaches its theoretical maximum value.

17.
Phys Chem Chem Phys ; 26(3): 2066-2072, 2024 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-38126725

RESUMEN

The kagome lattice is one of the most intriguing topics to study. It has a frustrated flat band touching a set of Dirac bands and can possess various promising properties, such as ferromagnetism, superconductivity, and a non-trivial topology. Covalent organic frameworks (COFs) are a rare type of inorganic material, however, they can provide a platform for generating certain required lattices. Based on first-principles density functional theory calculations, we show that a newly synthesized two-dimensional COF named COF-SH has novel enantiomorphic kagome bands, which include two sets of flat bands touching the Dirac bands around the Fermi level. The Bloch wave of the flat-valence band at the K-point shows the kagome nature of the phase interference. Under charge doping, the COF-SH exhibits a ferromagnetic ground state. Moreover, when COF-SH is doped with iodine atoms, a sizable gap in the system is opened between the flat bands and the Dirac bands due to the spin-orbit coupling (SOC) effect. Meanwhile, the spin degeneracy is lifted since the organic layer loses electrons due to the oxidizing property of iodine. In addition, our tight-binding analysis with the SOC effect shows that the flat valence band separates from the Dirac bands and holds a nonzero Chern number. Consequently, this I-doped COF can give rise to a quantum anomalous Hall effect.

18.
Curr Treat Options Oncol ; 25(5): 619-627, 2024 05.
Artículo en Inglés | MEDLINE | ID: mdl-38581550

RESUMEN

OPINION STATEMENT: Skin tumors commonly seen in dermatology are involved in all layers of the skin and appendages. While biopsy of affected skin remains an essential method to confirm diagnosis and to predicate tumor prognosis, it has its limitations. Recently, photodynamic diagnosis (PDD) has demonstrated high sensitivity in detecting affected skin and mucosal tissues, providing valuable guidance for precision surgery to resect skin and mucosal tumors. In this review, we summarized the literatures concerning the applications of PDD in diagnostic process and treatment of skin and mucosal conditions such as actinic keratoses (AK), basal cell carcinoma (BCC), squamous cell carcinoma (SCC), Bowen's disease (BD) and extramammary Paget's disease (EMPD). The findings suggest that PDD holds substantial promise for expanding clinical applications and deserves further research exploration.


Asunto(s)
Fotoquimioterapia , Neoplasias Cutáneas , Humanos , Neoplasias Cutáneas/diagnóstico , Neoplasias Cutáneas/terapia , Neoplasias Cutáneas/etiología , Fotoquimioterapia/métodos , Carcinoma Basocelular/diagnóstico , Carcinoma Basocelular/terapia , Manejo de la Enfermedad , Fármacos Fotosensibilizantes/uso terapéutico , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/terapia
19.
Environ Res ; 251(Pt 2): 118735, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38518905

RESUMEN

Inert construction and demolition waste from Hong Kong (HK public fills) has been used for marine trial reclamation in the Guanghai Bay (GHWT) of the Chinese Mainland. However, an environmental assessment of HK public fills is necessary due to higher radioactivity in HK soils than typical global levels. Here, radiation dose rate, gamma radionuclides and gross beta of HK public fills were analyzed. The origin information was explored using natural primordial radionuclides as fingerprints. Our data show that radiation dose rate of HK public fills before disposal was 0.14-0.54 (0.33 ± 0.03) µSv/h (n = 16,722 data with 2787 ships) in 2014, which is less than the GHWT background. Monthly detection of 238U, 226Ra, 210Pb, 232Th, 228Th, 40K, and gross beta in HK public fills was conducted on three random ships. Their specific activities were <6.27-155.5, 58.7-98.7, <7.83-238.2,97.9-168.6, 87.1-136.0, 463.1-1,018, and 1047-1658 Bq/kgDW, respectively. These results suggest that the radioactivity levels of HK public fills are essentially the same as the GHWT background. The study assessed potential risks using various indices icluding Raeq (Radium equivalent activity), Hex (External radiation hazard index), Hin (Internal radiation hazard index), Iγ (Gamma index), AUI (Activity utilization index), AUI (Activity utilization index), E (Annual effective dose), AGDE (Annual gonadal dose equivalent), RLI (Representative level index), Din (Indoor air absorbed dose rate), Dout (Outdoor air absorbed dose rate), and ELCR (Excess lifetime cancer risk). The study suggests that HK public fills should be used for the trial reclamation rather than building-house materials. This provides valuable insights for the resource utilization and minimizing environmental pollution of HK public fills. The aim is to offer fundamental technical assistance for future waste resource utilization, ecological protection, and restoration in the Guangdong-Hong Kong-Macao Greater Bay Area.


Asunto(s)
Bahías , Hong Kong , Monitoreo de Radiación/métodos , Materiales de Construcción/análisis
20.
Clin Lab ; 70(6)2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38868877

RESUMEN

BACKGROUND: This study aimed to improve the accuracy of the fibrinogen (Fib) prothrombin time-derived (PT-der) method. To achieve this, a value transfer method was introduced for calibration, and its effectiveness was assessed. METHODS: The PT-der Fib assay was calibrated by pooled samples (assigned by the von Clauss method) in three different ways: 1) multipoint calibration using an automatic dilution system, 2) multipoint calibration using a manual dilution method, and 3) manual calibration with multiple concentrations. Three calibration equations (1, 2, and 3) were obtained and an optimal equation was selected by comparing the detection results of the von Clauss method with the PT-der method. Subsequently, the optimal equation was assessed for an accuracy limit, and linear analysis and reference interval verification were performed following the guidelines (EP15-A and EP6-A) issued by the CLSI. RESULTS: Compared with the other two equations (equation 1 and 2), equation 3, available from manual calibration with multiple concentrations, showed a better performance for the PT-der determination in a primary cohort (n = 208), and a good agreement (99% of the results between 1.52 and 6.30 g/L were interchangeable) was validated (n = 3226). The reference interval was also verified in almost all healthy individuals (39/40). However, the discrep-ancy between the two methods was observed in several specific conditions, such as hyperfibrinolysis. CONCLUSIONS: Manual calibration with multiple concentrations is better for the Fib PT-der method assay. As a rapid, accurate, and economical test, the performance of the Fib PT-der method has been verified and may be more applicable than before.


Asunto(s)
Fibrinógeno , Tiempo de Protrombina , Humanos , Fibrinógeno/análisis , Fibrinógeno/metabolismo , Tiempo de Protrombina/métodos , Calibración , Adulto , Valores de Referencia , Femenino , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Adulto Joven , Anciano , Adolescente , Pruebas de Coagulación Sanguínea/métodos , Pruebas de Coagulación Sanguínea/normas , Anciano de 80 o más Años
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