Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 371
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
BMC Genomics ; 25(1): 158, 2024 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-38331736

RESUMEN

BACKGROUND: Studies have confirmed that Infectious bovine rhinotracheitis virus (IBRV) infection induces mitochondrial damage. MicroRNAs (miRNAs) are a class of noncoding RNA molecules, which are involved in various biological processes and pathological changes associated with mitochondrial damage. It is currently unclear whether miRNAs participate in IBRV-induced mitochondrial damage in Madin-Darby bovine kidney (MDBK) cells. RESULTS: In the present study, we used high-throughput sequencing technology, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis to screen for mitochondria-related miRNAs and messenger RNAs (mRNAs). In total, 279 differentially expressed miRNAs and 832 differentially expressed mRNAs were identified in 6 hours (IBRV1) versus 24 hours (IBRV2) after IBRV infection in MDBK cells. GO and KEGG enrichment analysis revealed that 42 differentially expressed mRNAs and 348 target genes of differentially expressed miRNAs were correlated with mitochondrial damage, and the miRNA-mitochondria-related target genes regulatory network was constructed to elucidate their potential regulatory relationships. Among the 10 differentially expressed miRNAs, 8 showed expression patterns consistent with the high-throughput sequencing results. Functional validation results showed that overexpression of miR-10a and miR-182 aggravated mitochondrial damage, while inhibition of miR-10a and miR-182 alleviated mitochondrial damage. CONCLUSIONS: This study not only revealed the expression changes of miRNAs and mRNAs in IBRV-infected MDBK cells, but also revealed possible biological regulatory relationship between them. MiR-10a and miR-182 may have the potential to be developed as biomarkers for the diagnosis and treatment of IBRV. Together, Together, these data and analyses provide additional insights into the roles of miRNA and mRNA in IBRV-induced mitochondria damage.


Asunto(s)
Herpesvirus Bovino 1 , MicroARNs , Animales , Bovinos , MicroARNs/genética , MicroARNs/metabolismo , Herpesvirus Bovino 1/genética , Células Epiteliales/metabolismo , Riñón/metabolismo , Redes Reguladoras de Genes , ARN Mensajero/genética , Perfilación de la Expresión Génica
2.
Small ; : e2400449, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38488742

RESUMEN

Materials with low intrinsic lattice thermal conductivity are crucial in the pursuit of high-performance thermoelectric (TE) materials. Here, the TE properties of PbBi2 Te4-x Sex (0 ≤ x ≤ 0.6) samples are systematically investigated for the first time. Doping with Se in PbBi2 Te4 can simultaneously reduce carrier concentration and increase carrier mobility. The Seebeck coefficient is significantly increased by doping with Se, based on the density functional theory calculation, it is shown to be due to the increased bandgap and electronic density of states. In addition, the lattice strain is enhanced due to the difference in the size of Se and Te atoms, and the multidimensional defects formed by Se doping, such as vacancies, dislocations, and grain boundaries, enhance the phonon scattering and reduce the lattice thermal conductivity by about 37%. Finally, by using Se doping to reduce carrier concentration and thermal conductivity, a large ZTmax = 0.56 (at 574K) is achieved for PbBi2 Te3.5 Se0.5 , which is around 64% larger than those of the PbBi2 Te4 pristine sample. This work not only demonstrates that PbBi2 Te4 is a potential medium temperature thermoelectric material, but also provides a reference for enhancing thermoelectric properties through defect and energy band engineering.

3.
Ann Bot ; 133(5-6): 697-710, 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38230804

RESUMEN

BACKGROUND AND AIMS: The staghorn fern genus Platycerium is one of the most commonly grown ornamental ferns, and it evolved to occupy a typical pantropical intercontinental disjunction. However, species-level relationships in the genus have not been well resolved, and the spatiotemporal evolutionary history of the genus also needs to be explored. METHODS: Plastomes of all the 18 Platycerium species were newly sequenced. Using plastome data, we reconstructed the phylogenetic relationships among Polypodiaceae members with a focus on Platycerium species, and further conducted molecular dating and biogeographical analyses of the genus. KEY RESULTS: The present analyses yielded a robustly supported phylogenetic hypothesis of Platycerium. Molecular dating results showed that Platycerium split from its sister genus Hovenkampia ~35.2 million years ago (Ma) near the Eocene-Oligocene boundary and began to diverge ~26.3 Ma during the late Oligocene, while multiple speciation events within Platycerium occurred during the middle to late Miocene. Biogeographical analysis suggested that Platycerium originated in tropical Africa and then dispersed eastward to southeast Asia-Australasia and westward to neotropical areas. CONCLUSIONS: Our analyses using a plastid phylogenomic approach improved our understanding of the species-level relationships within Platycerium. The global climate changes of both the Late Oligocene Warming and the cooling following the mid-Miocene Climate Optimum may have promoted the speciation of Platycerium, and transoceanic long-distance dispersal is the most plausible explanation for the pantropical distribution of the genus today. Our study investigating the biogeographical history of Platycerium provides a case study not only for the formation of the pantropical intercontinental disjunction of this fern genus but also the 'out of Africa' origin of plant lineages.


Asunto(s)
Filogenia , Filogeografía , Plastidios , Polypodiaceae , Polypodiaceae/genética , Polypodiaceae/clasificación , Plastidios/genética , Evolución Biológica , África , Helechos/genética , Helechos/clasificación , Evolución Molecular
4.
Cereb Cortex ; 33(14): 9095-9104, 2023 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-37231204

RESUMEN

Schizophrenia is a self-disorder characterized by disrupted brain dynamics and architectures of multiple molecules. This study aims to explore spatiotemporal dynamics and its association with psychiatric symptoms. Resting-state functional magnetic resonance imaging data were collected from 98 patients with schizophrenia. Brain dynamics included the temporal and spatial variations in functional connectivity density and association with symptom scores were evaluated. Moreover, the spatial association between dynamics and receptors/transporters according to prior molecular imaging in healthy subjects was examined. Patients demonstrated decreased temporal variation and increased spatial variation in perceptual and attentional systems. However, increased temporal variation and decreased spatial variation were revealed in higher order networks and subcortical networks in patients. Specifically, spatial variation in perceptual and attentional systems was associated with symptom severity. Moreover, case-control differences were associated with dopamine, serotonin and mu-opioid receptor densities, serotonin reuptake transporter density, dopamine transporter density, and dopamine synthesis capacity. Therefore, this study implicates the abnormal dynamic interactions between the perceptual system and cortical core networks; in addition, the subcortical regions play a role in the dynamic interaction among the cortical regions in schizophrenia. These convergent findings support the importance of brain dynamics and emphasize the contribution of primary information processing to the pathological mechanism underlying schizophrenia.


Asunto(s)
Esquizofrenia , Humanos , Dopamina , Serotonina , Imagen por Resonancia Magnética/métodos , Encéfalo , Mapeo Encefálico/métodos
5.
J Chem Phys ; 160(21)2024 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-38832747

RESUMEN

The interplay between orientation transition and chiral self-assemblies of para-terphenyl (P3P) molecules on the Cd(0001) surface has been investigated using low temperature scanning tunneling microscopy and density functional theory calculations. Three distinct molecular orientations have been discerned from the self-assembled thin films of P3P. At the low coverage, flat-lying molecules appear in the homochiral domains with the incommensurate registry to the substrate. With the coverage increasing, the incoming molecules are incorporated into the first layer with edge-on orientation and form the self-assembled zigzag chains. The alternative arrangement of zigzag chains with opposite chirality leads to the formation of a c(4 × 2) superstructure, in which the tilted molecules exhibit orientational frustration and fuzzy noises. The analysis of the tunneling spectra reveals that the electronic structure of P3P layers is contingent upon the hybridization between the electronic states of P3P molecules and the Cd(0001) surface. These results provide important insights into the interplay between orientational transition and chiral assembly of P3P molecules on metal substrates.

6.
BMC Public Health ; 24(1): 1358, 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38769474

RESUMEN

BACKGROUND: Understanding factors associated with antiretroviral treatment (ART) adherence is crucial for ART success among people living with HIV (PLHIV) in the "test and treat" era. Multiple psychosocial factors tend to coexist and have a syndemic effect on ART adherence. We aimed to explore factors associated with ART adherence and the syndemic effect of multiple psychosocial factors on ART adherence among PLHIV newly starting ART in Guangdong Province, China. METHODS: Newly diagnosed PLHIV from six cities in Guangdong Province were recruited between May 2018 and June 2019, and then followed up from May 2019 to August 2020. Baseline and follow-up data were collected from a questionnaire and the national HIV surveillance system, the follow-up data of which were analyzed in this study. A Center for Adherence Support Evaluation (CASE) index > 10 points was defined as optimal ART adherence, which was measured via participants' self-reported adherence during follow-up survey. Multivariable logistic regression was used to identify factors associated with ART adherence. Exploratory factor analysis (EFA) and multi-order latent variable structural equation modeling (SEM) were performed to explore the syndemic effect of multiple psychosocial factors on ART adherence. RESULTS: A total of 734 (68.53%) follow-up participants were finally included in this study among the 1071 baseline participants, of whom 91.28% (670/734) had self-reported optimal ART adherence. Unemployment (aOR = 1.75, 95%CI: 1.01-3.02), no medication reminder (aOR = 2.28, 95%CI: 1.09-4.74), low medication self-efficacy (aOR = 2.28, 95%CI: 1.27-4.10), low social cohesion (aOR = 1.82, 95%CI: 1.03-3.19), no social participation (aOR = 5.65, 95%CI: 1.71-18.63), and ART side effects (aOR = 0.46, 95%CI: 0.26-0.81) were barriers to optimal ART adherence. The EFA and second-order latent variable SEM showed a linear relationship (standardized coefficient = 0.43, P < 0.001) between ART adherence and the latent psychosocial (syndemic) factor, which consisted of the three latent factors of medication beliefs and self-efficacy (standardized coefficient = 0.65, P < 0.001), supportive environment (standardized coefficient = 0.50, P < 0.001), and negative emotions (standardized coefficient=-0.38, P < 0.01). The latent factors of medication beliefs and self-efficacy, supportive environment, and negative emotions explained 42.3%, 25.3%, and 14.1% of the variance in the latent psychosocial factor, respectively. CONCLUSIONS: About nine out of ten PLHIV on ART in Guangdong Province self-reported optimal ART adherence. However, more efforts should be made to address barriers to optimal ART adherence.


Asunto(s)
Infecciones por VIH , Cumplimiento de la Medicación , Humanos , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/psicología , China/epidemiología , Masculino , Femenino , Adulto , Estudios Transversales , Cumplimiento de la Medicación/estadística & datos numéricos , Cumplimiento de la Medicación/psicología , Persona de Mediana Edad , Antirretrovirales/uso terapéutico , Encuestas y Cuestionarios , Fármacos Anti-VIH/uso terapéutico , Adulto Joven
7.
Acta Biochim Biophys Sin (Shanghai) ; 56(1): 54-61, 2024 01 25.
Artículo en Inglés | MEDLINE | ID: mdl-38098360

RESUMEN

Long noncoding RNAs (lncRNAs) are important regulators of bone metabolism. In this study, lncRNA microarray analysis was used to identify differentially expressed lncRNAs in differentiated osteoclasts. lncRNA-Gm5532 is highly expressed during osteoclast differentiation. lncRNA-Gm5532 knockdown impairs osteoclast formation and bone resorption. Mechanistic experiments show that lncRNA-Gm5532 functions as a competing endogenous RNA (ceRNA) and acts as a sponge for miR-125a-3p, which promotes TNF receptor-associated factor 6 (TRAF6) expression. miR-125a-3p mimics suppress osteoclast differentiation and TAK1/NF-κB/MAPK signaling. The miR-125a-3p inhibitor reverses the negative effects of siGm5532 on osteoclast differentiation. In summary, our study reveals that lncRNA-Gm5532 functions as an activator in osteoclast differentiation by targeting the miR-125a-3p/TRAF6 axis, making it a novel biomarker and potential therapeutic target for osteoporosis.


Asunto(s)
Resorción Ósea , MicroARNs , ARN Largo no Codificante , Humanos , MicroARNs/metabolismo , Osteoclastos/metabolismo , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Factor 6 Asociado a Receptor de TNF/genética , Factor 6 Asociado a Receptor de TNF/metabolismo , Resorción Ósea/genética , Resorción Ósea/metabolismo
8.
BMC Biol ; 21(1): 50, 2023 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-36882831

RESUMEN

BACKGROUND: Over the past decade, phylogenomics has greatly advanced our knowledge of angiosperm evolution. However, phylogenomic studies of large angiosperm families with complete species or genus-level sampling are still lacking. The palms, Arecaceae, are a large family with ca. 181 genera and 2600 species and are important components of tropical rainforests bearing great cultural and economic significance. Taxonomy and phylogeny of the family have been extensively investigated by a series of molecular phylogenetic studies in the last two decades. Nevertheless, some phylogenetic relationships within the family are not yet well-resolved, especially at the tribal and generic levels, with consequent impacts for downstream research. RESULTS: Plastomes of 182 palm species representing 111 genera were newly sequenced. Combining these with previously published plastid DNA data, we were able to sample 98% of palm genera and conduct a plastid phylogenomic investigation of the family. Maximum likelihood analyses yielded a robustly supported phylogenetic hypothesis. Phylogenetic relationships among all five palm subfamilies and 28 tribes were well-resolved, and most inter-generic phylogenetic relationships were also resolved with strong support. CONCLUSIONS: The inclusion of nearly complete generic-level sampling coupled with nearly complete plastid genomes strengthened our understanding of plastid-based relationships of the palms. This comprehensive plastid genome dataset complements a growing body of nuclear genomic data. Together, these datasets form a novel phylogenomic baseline for the palms and an increasingly robust framework for future comparative biological studies of this exceptionally important plant family.


Asunto(s)
Arecaceae , Magnoliopsida , Arecaceae/genética , Filogenia , Genómica , Plastidios/genética
9.
Molecules ; 29(6)2024 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-38542890

RESUMEN

An unparalleled copper(I)-catalyzed synthesis of 1,3,4-oxadiazoles from tertiary amines in one step has been described. The one-pot reactions involving (N-isocyanimine)triphenylphosphorane, tertiary amines, and carboxylic acids resulted in the formation of 1,3,4-oxadiazoles in moderate to good yields through a consecutive oxidative Ugi/aza-Wittig reaction, enabling the direct functionalization of sp3 C-H bonds adjacent to the nitrogen atom. This method offered several notable advantages, including ligands-free, exceptional productivity and a high functional group tolerance. The preliminary biological evaluation demonstrated that compound 4f inhibited hepatoma cells efficiently, suggesting potentially broad applications of the approach for synthesis and medicinal chemistry.


Asunto(s)
Cobre , Compuestos Organofosforados , Oxadiazoles , Cobre/química , Oxadiazoles/química , Aminas/química , Catálisis , Estrés Oxidativo
10.
Bioconjug Chem ; 34(6): 988-993, 2023 06 21.
Artículo en Inglés | MEDLINE | ID: mdl-37216465

RESUMEN

Macrocycles occupy chemical space "beyond the rule of five". They bridge traditional bioactive small molecule drugs and macromolecules and have the potential to modulate challenging targets such as PPI or proteases. Here we report an on-DNA macrocyclization reaction utilizing intramolecular benzimidazole formation. A 129-million-member macrocyclic library composed of a privileged benzimidazole core, a dipeptide sequence (natural or non-natural), and linkers of varying length and flexibility was designed and synthesized.


Asunto(s)
Compuestos Macrocíclicos , Compuestos Macrocíclicos/química , Biblioteca de Genes , Ciclización , Bencimidazoles , ADN/química
11.
BMC Cancer ; 23(1): 388, 2023 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-37127623

RESUMEN

BACKGROUND: In recent years, there has been growing evidence indicating a relationship between liquid-liquid phase separation (LLPS) and cancer development. However, to date, the clinical significance of LLPS in skin cutaneous melanoma (SKCM, hereafter referred to as melanoma) remains to be elucidated. In the current study, the impact of LLPS-related genes on melanoma prognosis has been explored. METHODS: LLPS-related genes were retrieved from the DrLLPS database. The prognostic feature for LLPS in melanoma was developed in The Cancer Genome Atlas (TCGA) dataset and verified in the GSE65904 cohort. Based on risk scores, melanoma patients were categorized into high- and low-risk groups. Thereafter, the differences in clinicopathological correlation, functional enrichment, immune landscape, tumor mutational burden, and impact of immunotherapy between the two groups were investigated. Finally, the role of key gene TROAP in melanoma was validated by in vitro and in vivo experiments. RESULTS: The LLPS-related gene signature was developed based on MLKL, PARVA, PKP1, PSME1, RNF114, and TROAP. The risk score was a crucial independent prognostic factor for melanoma and patients with high-risk scores were related to a worse prognosis. Approximately, all immune-relevant characteristics, such as immune cell infiltration and immune scores, were extremely evident in patients with low-risk scores. The findings from the in vitro and in vivo experiments indicated that the viability, proliferation, and invasion ability of melanoma cells were drastically decreased after the knockdown of TROAP. CONCLUSION: Our gene signature can independently predict the survival of melanoma patients. It provides a basis for the exploration of the relationship between LLPS and melanoma and can offer a fresh perspective on the clinical diagnosis and treatment of the disease.


Asunto(s)
Melanoma , Neoplasias Cutáneas , Humanos , Inmunoterapia , Factores de Riesgo , Pronóstico , Melanoma Cutáneo Maligno
12.
J Org Chem ; 88(18): 13125-13134, 2023 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-37616489

RESUMEN

A new one-pot synthesis of imidazo[1,2-a]pyridine-fused 1,3-benzodiazepine derivatives via a sequential GBB-3CR/Pd(II)-catalyzed azide-isocyanide coupling/cyclization process was developed. The Groebke-Blackburn-Bienaymé three-component reactions (GBB-3CR) of 2-aminopyridine, 2-azidobenzaldehydes, and isocyanides in the presence of a catalytic amount of p-toluenesulfonic acid gave azide intermediates without separation. The reaction was followed by using another molecule of isocyanides to produce imidazo[1,2-a]pyridine-fused 1,3-benzodiazepine derivatives in good yields by the Pd(II)-catalyzed azide-isocyanide coupling/cyclization reaction. The synthetic approach produces novel nitrogen-fused polycyclic heterocycles under mild reaction conditions. The preliminary biological evaluation demonstrated that compound 6a inhibited glioma cells efficiently, suggesting potentially broad applications of the approach for synthesis and medicinal chemistry.

13.
Cell Biol Toxicol ; 39(6): 3305-3321, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37855941

RESUMEN

Iron overload enhances osteoclastic bone resorption and induces osteoporosis. Excess iron is highly toxic. The modulation of redox and iron homeostasis is critical for osteoclast differentiation under iron-overload condition. Nuclear factor erythroid 2-related factor 2 (NRF2) is a transcription factor that regulates the cellular defense against oxidative stress and iron overload through the expression of genes involved in anti-oxidative processes and iron metabolism. Our studies demonstrated that NRF2 activation was suppressed during osteoclast differentiation. Under iron-overload condition, NRF2 and its mediated antioxidant and iron metabolism genes were activated by reactive oxygen species (ROS), which enhanced antioxidant capability. NRF2 mediated the upregulation of iron exporter ferroportin 1 (FPN1) and iron storage protein ferritin, contributing to decreased levels of intracellular iron. Nfe2l2 knockout induced oxidative stress and promoted osteoclast differentiation under normal condition, but induced ferroptosis under iron-overload condition. Nfe2l2 knockout alleviated iron overload induced bone loss by inhibiting osteoclast differentiation. Our results suggest that NRF2 activation is essential for osteoclast differentiation by enhancing antioxidant capability and reducing intracellular iron under iron-overload condition. Targeting NRF2 to induce ferroptosis could be a potential therapy for the treatment of iron-overload induced osteoporosis.


Asunto(s)
Resorción Ósea , Sobrecarga de Hierro , Osteoporosis , Antioxidantes/farmacología , Resorción Ósea/metabolismo , Homeostasis , Hierro/metabolismo , Sobrecarga de Hierro/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Osteoclastos/metabolismo , Osteoporosis/metabolismo , Oxidación-Reducción , Especies Reactivas de Oxígeno/metabolismo , Animales , Ratones , Células RAW 264.7
14.
Environ Sci Technol ; 57(50): 21416-21427, 2023 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-38064647

RESUMEN

Accurately controlling catalytic activity and mechanism as well as identifying structure-activity-selectivity correlations in Fenton-like chemistry is essential for designing high-performance catalysts for sustainable water decontamination. Herein, active center size-dependent catalysts with single cobalt atoms (CoSA), atomic clusters (CoAC), and nanoparticles (CoNP) were fabricated to realize the changeover of catalytic activity and mechanism in peroxymonosulfate (PMS)-based Fenton-like chemistry. Catalytic activity and durability vary with the change in metal active center sizes. Besides, reducing the metal size from nanoparticles to single atoms significantly modulates contributions of radical and nonradical mechanisms, thus achieving selective/nonselective degradation. Density functional theory calculations reveal evolutions in catalytic mechanisms of size-dependent catalytic systems over different Gibbs free energies for reactive oxygen species generation. Single-atom site contact with PMS is preferred to induce nonradical mechanisms, while PMS dissociates and generates radicals on clusters and nanoparticles. Differences originating from reaction mechanisms endow developed systems with size-dependent selectivity and mineralization for treating actual hospital wastewater in column reactors. This work brings an in-depth understanding of metal size effects in Fenton-like chemistry and guides the design of intelligent catalysts to fulfill the demand of specific scenes for water purification.


Asunto(s)
Cobalto , Descontaminación , Catálisis , Agua
15.
Environ Sci Technol ; 57(8): 3334-3344, 2023 02 28.
Artículo en Inglés | MEDLINE | ID: mdl-36734031

RESUMEN

Accelerating the rate-limiting Fe3+/Fe2+ circulation in Fenton reactions through the addition of reducing agents (or co-catalysts) stands out as one of the most promising technologies for rapid water decontamination. However, conventional reducing agents such as hydroxylamine and metal sulfides are greatly restricted by three intractable challenges: (1) self-quenching effects, (2) heavy metal dissolution, and (3) irreversible capacity decline. To this end, we, for the first time, introduced redox-active polymers as electron shuttles to expedite the Fe3+/Fe2+ cycle and promote H2O2 activation. The reduction of Fe3+ mainly took place at active N-H or O-H bonds through a proton-coupled electron transfer process. As electron carriers, H atoms at the solid phase could effectively inhibit radical quenching, avoid metal dissolution, and maintain long-term reducing capacity via facile regeneration. Experimental and density functional theory (DFT) calculation results indicated that the activity of different polymers shows a volcano curve trend as a function of the energy barrier, highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gap, and vertical ionization potential. Thanks to the appropriate redox ability, polyaniline outperforms other redox-active polymers (e.g., poypyrrole, hydroquinone resin, poly(2,6-diaminopyridine), and hexaazatrinaphthalene framework) with a highest iron reduction capacity up to 5.5 mmol/g, which corresponds to the state transformation from leucoemeraldine to emeraldine. Moreover, the proposed system exhibited high pollutant removal efficiency in a flow-through reactor for 8000 bed volumes without an obvious decline in performance. Overall, this work established a green and sustainable oxidation system, which offers great potential for practical organic wastewater remediation.


Asunto(s)
Peróxido de Hidrógeno , Hierro , Hierro/química , Peróxido de Hidrógeno/química , Sustancias Reductoras , Electrones , Oxidación-Reducción
16.
J Chem Phys ; 159(21)2023 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-38038204

RESUMEN

We have studied the epitaxial growth of Si thin films on the Cd(0001) surface using low-temperature scanning tunneling microscopy. When deposited at low temperatures (100 K), Si atoms form dendritic islands with triangular shapes, indicating the existence of anisotropic edge diffusion in the process of Si film growth. After annealing to elevated temperatures, the triangular dendritic Si islands become hexagonal compact islands. Moreover, the 2D Si islands located on two different substrate terraces exhibit different heights due to the influence of quantum-well states in Cd(0001) films. Based on high-resolution scanning tunneling microscopy images, it is observed that the first, second, and third Si layers show the pseudomorphic 1 × 1 structure. In particular, the first and second layer islands reveal the opposite triangles, indicating the hexagonal close-packed stacking of Si atoms. These results provide important information for the growth of pristine Si films on metal substrates and the understanding of Si-metal interaction.

17.
BMC Ophthalmol ; 23(1): 516, 2023 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-38114950

RESUMEN

BACKGROUND: Here we described a new threading technique for the universal fixation of any posterior chamber intraocular lens (IOL). METHODS: Twenty-seven eyes of 27 patients whose surgery done by Surgeon A with the needle-guided method or the suture needle retrograde threading (SNRT) method for intrascleral IOL fixation were enrolled in the first group. Thirty-four eyes of 34 patients whose surgery done by Surgeon A, Surgeon B or Surgeon C with the SNRT method for intrascleral IOL fixation were grouped into three sub-groups by surgeon. Information regarding age, sex, best-available visual acuity (BCVA), intraocular pressure (IOP), past ophthalmological history, threading time (from puncturing to externalizing suture) and complications during and after the surgery were gathered. RESULTS: The analysis showed that the threading time was less in the SNRT group than needle-guided group by Surgeon A. There was one eye with suture needle slipping from the guide needle when guiding out of the eye. The threading procedure was completed one time without suture ruptures or loop slippage in the SNRT group operated by Surgeon A. And using the SNRT method, Surgeon A, Surgeon B, and Surgeon C did not show any significant difference in threading time. No complications (e.g., vitreous hemorrhage, hyphemia, retinal detachment, suprachoroidal hemorrhage, or hypotony) were observed during surgery or postoperatively in all cases. No leakage occurred at the site of the puncture after the operation. CONCLUSIONS: The described technique appears to be a safe, simple, easy-to-learn, and universal surgical method, which is suitable for various types of IOLs.


Asunto(s)
Implantación de Lentes Intraoculares , Lentes Intraoculares , Humanos , Implantación de Lentes Intraoculares/métodos , Esclerótica/cirugía , Ojo Artificial , Técnicas de Sutura , Suturas , Estudios Retrospectivos , Complicaciones Posoperatorias/cirugía
18.
BMC Ophthalmol ; 23(1): 332, 2023 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-37474888

RESUMEN

BACKGROUND: To evaluate the influence of decentration of plate-haptic toric intraocular lens (IOLs) on visual quality. METHODS: This study enrolled 78 eyes of 78 patients. Patients in group A were implanted with toric IOLs, and patients in group B were implanted with monofocal IOLs. All patients were divided into group A1 and B1 (decentration below 0.3 mm) and group A2 and B2 (decentration above 0.3 mm). The uncorrected distance visual acuity (UDVA), best corrected visual acuity (BCVA), modulation transfer function cutoff (MTF cutoff), objective scatter index (OSI), strehl ratio (SR), optical interference and patients' satisfaction were measured in different pupils at three months postoperatively. The associations between decentration and visual quality were analyzed by Spearman correlation. RESULTS: There were no significant differences in UDVA, BCVA, MTF cutoff, OSI, SR, optical interference and patients' satisfaction among subgroups. The differences in decentration between groups A and B were not statistically significant. In group A2, the total higher order aberrations (tHOAs) at pupil sizes of 3 mm (P = 0.046), 5 mm (P = 0.014), spherical aberrations at pupil sizes of 3 mm (P = 0.011), 4 mm (P = 0.014), 5 mm (P = 0.000), secondary astigmatism at pupil sizes of 3 mm (P = 0.002), 4 mm (P = 0.005) were higher than in group B2. Compared to group A1, group A2 had higher spherical aberrations at pupil sizes of 4 mm (P = 0.042), 5 mm (P = 0.001), 6 mm (P = 0.038), secondary astigmatism at pupil sizes of 3 mm (P = 0.013), 4 mm (P = 0.005), 6 mm (P = 0.013). Group B2 has higher coma and secondary astigmatism than group B1 at 6-mm pupil (P = 0.014, P = 0.045). Significant positive correlations were found between spherical aberrations and the decentration of group A1 and A2 at 6-mm pupils. CONCLUSION: The decentration above 0.3 mm negatively affected visual quality due to increased tHOAs, spherical aberrations, coma and secondary astigmatism aberrations, the influence become larger with increasing pupil diameter. And toric IOLs are more affected by decentration than monofocal IOLs.


Asunto(s)
Astigmatismo , Lentes Intraoculares , Facoemulsificación , Humanos , Implantación de Lentes Intraoculares , Astigmatismo/cirugía , Astigmatismo/complicaciones , Coma/complicaciones , Coma/cirugía , Tecnología Háptica
19.
BMC Biol ; 20(1): 182, 2022 08 19.
Artículo en Inglés | MEDLINE | ID: mdl-35986286

RESUMEN

BACKGROUND: SP140 is a bromodomain-containing protein expressed predominantly in immune cells. Genetic polymorphisms and epigenetic modifications in the SP140 locus have been linked to Crohn's disease (CD), suggesting a role in inflammation. RESULTS: We report the development of the first small molecule SP140 inhibitor (GSK761) and utilize this to elucidate SP140 function in macrophages. We show that SP140 is highly expressed in CD mucosal macrophages and in in vitro-generated inflammatory macrophages. SP140 inhibition through GSK761 reduced monocyte-to-inflammatory macrophage differentiation and lipopolysaccharide (LPS)-induced inflammatory activation, while inducing the generation of CD206+ regulatory macrophages that were shown to associate with a therapeutic response to anti-TNF in CD patients. SP140 preferentially occupies transcriptional start sites in inflammatory macrophages, with enrichment at gene loci encoding pro-inflammatory cytokines/chemokines and inflammatory pathways. GSK761 specifically reduces SP140 chromatin binding and thereby expression of SP140-regulated genes. GSK761 inhibits the expression of cytokines, including TNF, by CD14+ macrophages isolated from CD intestinal mucosa. CONCLUSIONS: This study identifies SP140 as a druggable epigenetic therapeutic target for CD.


Asunto(s)
Enfermedad de Crohn , Inhibidores del Factor de Necrosis Tumoral , Antígenos Nucleares/genética , Antígenos Nucleares/metabolismo , Enfermedad de Crohn/genética , Enfermedad de Crohn/metabolismo , Citocinas/genética , Citocinas/metabolismo , Epigénesis Genética , Humanos , Macrófagos , Factores de Transcripción/genética
20.
J Org Chem ; 87(15): 9488-9496, 2022 08 05.
Artículo en Inglés | MEDLINE | ID: mdl-35881945

RESUMEN

A new one-pot preparation of 4-tetrazolyl-3,4-dihydroquinazolines has been reported. The Ugi-azide reactions of 2-azidobenzaldehydes, amines, trimethylsilyl azide, and isocyanides produced azide intermediates without separation, which were treated with isocyanides to give 4-tetrazolyl-3,4-dihydroquinazoline derivatives through a sequential Palladium-catalyzed azide-isocyanide cross-coupling/cyclization reaction in moderate to good yields. The biological evaluation demonstrated that compound 6c inhibited breast cancer cells well and displayed broad applications for synthesis and medicinal chemistry.


Asunto(s)
Cianuros , Paladio , Azidas , Catálisis , Cianuros/química , Ciclización , Estructura Molecular , Paladio/química
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA