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1.
Small ; 20(12): e2307827, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37949815

RESUMO

Organic frameworks-based batteries with excellent physicochemical stability and long-term high capacity will definitely reduce the cost, carbon emissions, and metal consumption and contamination. Here, an ultra-stable and ultra-thin perylene-dicyandiamide-based hydrogen organic framework (HOF) nanosheet (P-DCD) of ≈3.5 nm in thickness is developed. When applied in the cathode, the P-DCD exhibits exceptional long-term capacity retention for alkali-ion batteries (AIBs). Strikingly, for lithium-ion batteries (LIBs), at current of 2 A g-1, the large reversible capacity of 108 mA h g-1 shows no attenuation within 5 000 cycles. For sodium-ion batteries (SIBs), the related capacity retains 91.7% within 10 000 cycles compared to the initial state, significantly much more stable than conventional organic materials reported previously. Mechanism studies through ex situ and in situ experiments and theoretical density functional theory (DFT) calculations reveal that the impressive long-term performance retention originates from the large electron delocalization, fast ion diffusion, and physicochemical stability within the ultra-thin 2D P-DCD, featuring π-π and hydrogen bonding stacking, nitrogen-rich units, and low impedance. The advantageous features demonstrate that rationally designed stable and effective organic frameworks pave the way to utilizing complete organic materials for developing next-generation low-cost and highly stable energy storage batteries.

2.
Plant Cell Environ ; 47(6): 2258-2273, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38482979

RESUMO

Sirtuins (SRTs) are a group of nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase that target both histone and nonhistone proteins. The biological function of SRT in horticultural plants has been rarely studied. In this study, FaSRT1-2 was identified as a key member of the 8 FaSRTs encoded in cultivated strawberry genome. Transient overexpression of FaSRT1-2 in strawberry fruit accelerated ripening, increased the content of anthocyanins and sugars, enhanced ripening-related gene expression. Moreover, stable transformation of FaSRT1-2 in strawberry plants resulted in enhanced vegetative growth, increased sensitivity to heat stress and increased susceptibility to Botrytis cinerea infection. Interestingly, knocking out the homologous gene in woodland strawberry had the opposite effects. Additionally, we found the content of stress-related hormone abscisic acid (ABA) was decreased, while the growth-related gibberellin (GA) concentration was increased in FaSRT1-2 overexpression lines. Gene expression analysis revealed induction of heat shock proteins, transcription factors, stress-related and antioxidant genes in the FaSRT1-2-overexpressed plants while knocked-out of the gene had the opposite impact. In conclusion, our findings demonstrated that FaSRT1-2 could positively promote strawberry plant vegetative growth and fruit ripening by affecting ABA and GA pathways. However, it negatively regulates the resistance to heat stress and B. cinerea infection by influencing the related gene expression.


Assuntos
Botrytis , Fragaria , Frutas , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas , Fragaria/genética , Fragaria/crescimento & desenvolvimento , Fragaria/fisiologia , Fragaria/metabolismo , Frutas/genética , Frutas/crescimento & desenvolvimento , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Botrytis/fisiologia , Histona Desacetilases/metabolismo , Histona Desacetilases/genética , Doenças das Plantas/microbiologia , Doenças das Plantas/genética , Ácido Abscísico/metabolismo , Estresse Fisiológico/genética , Reguladores de Crescimento de Plantas/metabolismo , Giberelinas/metabolismo , Plantas Geneticamente Modificadas , Resistência à Doença/genética
3.
Am J Obstet Gynecol ; 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38782229

RESUMO

BACKGROUND: With remarkable advancements in assisted reproductive technology (ART), the number of ART-conceived children continues to increase. Despite increased research investigating the outcomes of ART children, evidence on neurodevelopment remains controversial. OBJECTIVE: The aim of this study was to investigate the association between ART use and neurodevelopment in children at 1 year of age and to determine whether the characteristics of parental infertility and specific ART procedures affect neurodevelopment in children. STUDY DESIGN: The Jiangsu Birth Cohort enrolled couples who received ART treatment and who conceived spontaneously (2014-2020) in Jiangsu Province, China. In this study, we included 3531 pregnancies with 3840 cohort children who completed neurodevelopment assessment at 1 year of age, including 1906 infants conceived by ART (including 621 twins). Poisson regressions were fitted to estimate unadjusted and adjusted risk ratios (RRs) and 95% confidence intervals (CIs) for ART use with neurodevelopmental outcomes (cognition, receptive communication, expressive communication, fine motor, and gross motor) in children. RESULTS: Among singletons, ART use was associated with a 24% to 34% decrease in the risk for noncompetent development in 3 domains (cognition, adjusted RR, 0.66; 95% CI, 0.53-0.82; receptive communication, 0.76; 0.64-0.91; expressive communication, 0.69; 0.51-0.93) after adjustment for conventional covariates. However, an inverse association was observed in the gross motor domain, with ART singletons having a greater risk of being noncompetent in gross motor development than their non-ART counterparts (adjusted RR, 1.41; 95% CI, 1.11-1.79). Compared with singletons, twins resulting from ART treatment demonstrated compromised neurodevelopment in several domains. Furthermore, we continued to observe that the transfer of 'poor' quality embryos was associated with greater risks for noncompetent development in receptive communication (adjusted RR, 1.50; 95% CI, 1.05-2.14) and gross motor domains (1.55; 1.02-2.36) among ART singletons. CONCLUSION: These results generally provide reassuring evidence among singletons born after ART in the cognition, communication, and fine motor domains, but drawn attention to their gross motor development. The quality of transferred embryos in ART treatment might be associated with offspring neurodevelopment; however, the potential associations warrant further validation in independent studies, and the clinical significance needs careful interpretation.

4.
J Asian Nat Prod Res ; : 1-9, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38389314

RESUMO

Two new aporphine alkaloids, 6aR-2'-(3-oxobutenyl)-thaliadin (1) and N-methylthalisopynine (2), along with ten known analogs (3-12), were isolated from the roots of Thalictrum omeiense W. T. Wang et S. H. Wang. Their structures were determined by extensive spectroscopic and X-ray crystallographic analyses. Compounds 1-7 and 9-12 were tested for their antiproliferative effects in vitro against two human cancer cell lines (A549 and MCF-7). Among them, compounds 1, 3, and 7 exhibited moderate inhibitory activity against the tested cell lines with IC50 values ranging from 23.73 to 34.97 µM.

5.
J Comput Chem ; 44(21): 1776-1785, 2023 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-37133985

RESUMO

A nonionizing ultrafast laser pulse of 20-fs duration with a peak amplitude electric-field ±E = 200 × 10-4 a.u. was simulated. It was applied to the ethene molecule to consider its effect on the electron dynamics, both during the application of the laser pulse and for up to 100 fs after the pulse was switched off. Four laser pulse frequencies ω = 0.2692, 0.2808, 0.2830, and 0.2900 a.u. were chosen to correspond to excitation energies mid-way between the (S1 ,S2 ), (S2 ,S3 ), (S3 ,S4 ) and (S4 ,S5 ) electronic states, respectively. Scalar quantum theory of atoms in molecules (QTAIM) was used to quantify the shifts of the C1C2 bond critical points (BCPs). Depending on the frequencies ω selected, the C1C2 BCP shifts were up to 5.8 times higher after the pulse was switched off compared with a static E-field with the same magnitude. Next generation QTAIM (NG-QTAIM) was used to visualize and quantify the directional chemical character. In particular, polarization effects and bond strengths, in the form of bond-rigidity vs. bond-flexibility, were found, for some laser pulse frequencies, to increase after the laser pulse was switched off. Our analysis demonstrates that NG-QTAIM, in partnership with ultrafast laser irradiation, is useful as a tool in the emerging field of ultrafast electron dynamics, which will be essential for the design, and control of molecular electronic devices.

6.
BMC Med Imaging ; 23(1): 122, 2023 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-37697248

RESUMO

OBJECTIVES: To compare the inter-modality consistency and diagnostic performances of the contrast-enhanced ultrasound (CEUS) Liver Imaging Reporting and Data System (LI-RADS) and contrast-enhanced computed tomography (CECT) LI-RADS in patients at risk for hepatocellular carcinoma (HCC), so as to help clinicians to select a more appropriate modality to follow the focal liver lesions (FLLs). METHODS: This retrospective study included untreated 277 FLLs from 247 patients who underwent both CEUS and CECT within 1 month. The ultrasound contrast medium used was SonoVue. FLL categories were independently assigned by two ultrasound physicians and two radiologists using CEUS LI-RADS v2017 and CECT LI-RADS v2018, respectively. The diagnostic performances of CEUS and CECT LI-RADS were evaluated using sensitivity, specificity, positive predictive value (PPV), and negative predictive value. Cohen's Kappa was employed to evaluate the concordance of the LI-RADS category. RESULTS: The inter-modality consistency for CEUS and CECT LI-RADS was 0.31 (p < 0.001). HCC was more frequently observed in CECT LR-3 and LR-4 hepatic lesions than in CEUS (7.3% vs. 19.5%, p < 0.001). The specificity and PPV of CEUS and CECT LR-5 for the diagnosis of HCC were 89.5%, 95.0%, and 82.5%, 94.4%, respectively. The sensitivity of CEUS LR-5 + LR-M for the diagnosis of hepatic malignancies was higher than that of CECT (93.7% vs. 82.7%, p < 0.001). The specificity and PPV of CEUS LR-M for the diagnosis of non-HCC malignancies were lower than those of CECT (59.7% vs. 95.5%, p < 0.001; 23.4% vs. 70.3%, p < 0.001). CONCLUSIONS: The inter-modality consistency between the CEUS and CECT LI-RADS categories is fair. CEUS LI-RADS was more sensitive than CECT LI-RADS in terms of identifying hepatic malignancies, but weaker in terms of separating HCC from non-HCC malignancies.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico por imagem , Estudos Retrospectivos , Neoplasias Hepáticas/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Meios de Contraste
7.
Int J Mol Sci ; 24(11)2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-37298465

RESUMO

Ascorbic acid (AsA) is a crucial water-soluble antioxidant in strawberry fruit, but limited research is currently available on the identification and functional validation of key genes involved in AsA metabolism in strawberries. This study analyzed the FaMDHAR gene family identification, which includes 168 genes. Most of the products of these genes are predicted to exist in the chloroplast and cytoplasm. The promoter region is rich in cis-acting elements related to plant growth and development, stress and light response. Meanwhile, the key gene FaMDHAR50 that positively regulates AsA regeneration was identified through comparative transcriptome analysis of 'Benihoppe' strawberry (WT) and its natural mutant (MT) with high AsA content (83 mg/100 g FW). The transient overexpression experiment further showed that overexpression of FaMDHAR50 significantly enhanced the AsA content by 38% in strawberry fruit, with the upregulated expression of structural genes involved in AsA biosynthesis (FaGalUR and FaGalLDH) and recycling and degradation (FaAPX, FaAO and FaDHAR) compared with that of the control. Moreover, increased sugar (sucrose, glucose and fructose) contents and decreased firmness and citric acid contents were observed in the overexpressed fruit, which were accompanied by the upregulation of FaSNS, FaSPS, FaCEL1 and FaACL, as well as the downregulation of FaCS. Additionally, the content of pelargonidin 3-glucoside markedly decreased, while cyanidin chloride increased significantly. In summary, FaMDHAR50 is a key positive regulatory gene involved in AsA regeneration in strawberry fruit, which also plays an important role in the formation of fruit flavor, apperance and texture during strawberry fruit ripening.


Assuntos
Ácido Ascórbico , Fragaria , Ácido Ascórbico/metabolismo , Fragaria/metabolismo , Transcriptoma , Frutas/metabolismo , Antioxidantes/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo
8.
J Environ Manage ; 326(Pt A): 116682, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36375428

RESUMO

Due to increasing population pressure and urbanization, as well as global climate change impacts, many coastal river deltas are experiencing increased exposure, vulnerability and risks linked to natural hazards. Mapping the vulnerability and risk profiles of deltas is critical for developing preparedness, mitigation and adaptation policies and strategies. Current vulnerability and risk assessments focus predominantly on social factors, and typically, do not systematically incorporate a social-ecological systems perspective, which can lead to incomplete assessments. We argue that ecosystem services, which link both ecosystem functions and human well-being, can be used to better characterize the mutual dependencies between society and the environment within risk assessment frameworks. Thus, building on existing vulnerability and risk assessment frameworks, we propose a revised indicator-based framework for social-ecological systems of coastal delta environments, supported by a list of ecosystem service indicators that were identified using a systematic literature review. This improved framework is an effective tool to address the vulnerability and risk in coastal deltas, enabling the assessment of multi-hazard risks to social-ecological systems within and across coastal deltas and allows more targeted development of management measures and policies aimed at reducing risks from natural hazards.


Assuntos
Mudança Climática , Ecossistema , Humanos , Aclimatação , Medição de Risco , Urbanização
9.
Entropy (Basel) ; 25(3)2023 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-36981346

RESUMO

The same people exhibit various adoption behaviors for the same information on various networks. Previous studies, however, did not examine the variety of adoption behaviors on multi-layer networks or take into consideration this phenomenon. Therefore, we refer to this phenomenon, which lacks systematic analysis and investigation, as behavioral adoption diversity on multi-layered networks. Meanwhile, individual adoption behaviors have LTI (local trend imitation) characteristics that help spread information. In order to study the diverse LTI behaviors on information propagation, a two-layer network model is presented. Following that, we provide two adoption threshold functions to describe diverse LTI behaviors. The crossover phenomena in the phase transition is shown to exist through theoretical derivation and experimental simulation. Specifically, the final spreading scale displays a second-order continuous phase transition when individuals exhibit active LTI behaviors, and, when individuals behave negatively, a first-order discontinuous phase transition can be noticed in the final spreading scale. Additionally, the propagation phenomena might be impacted by the degree distribution heterogeneity. Finally, there is a good agreement between the outcomes of our theoretical analysis and simulation.

10.
Bioorg Chem ; 127: 105994, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35792314

RESUMO

Three series of quinazoline derivatives (7a-j, 8a-o, 9a-l) were designed and synthesized as EGFRL858R/T790M inhibitors. Series 7a-j and 8a-o are urea and thiourea derivatives while category 9a-l contain the Michael receptor active warhead. Most of the compounds exhibited excellent anti-proliferative activity in vitro against several cancer cell lines, including non-small cell lung cancer (NSCLC) cell lines A549 and H1975, among which 14 compounds had strong antiproliferative activity against A549 and H1975 cancer cells. What's more, they also showed moderate to excellent kinase inhibitory activity against EGFRWT and EGFRL858R/T790M. 8o exhibited the best kinase inhibitory activity with IC50 values of 0.8, 2.7 nM against EGFRWT and EGFRL858R/T790M, respectively. Moreover, AO single staining and Annexin V-FITC/PI staining results also indicated that both 8o and 9b significantly induced apoptosis in A549 cells. 8o arrested the cell cycle at S phase and 9b arrested the cell cycle at G1 phase.


Assuntos
Antineoplásicos , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Receptores ErbB , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Estrutura Molecular , Mutação , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Quinazolinas/farmacologia , Quinazolinas/uso terapêutico , Relação Estrutura-Atividade
11.
Chem Soc Rev ; 50(3): 2147-2172, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33331365

RESUMO

Photocatalysis with stable, efficient and inexpensive metal-free catalysts is one of the most promising options for non-polluting energy production. This review article covers the state-of-the-art development of various effective metal-free polymeric photocatalysts with large π-conjugated units for chemical transformations including water splitting, CO2 and N2 reduction, organic synthesis and monomer polymerisation. The article starts with the catalytic mechanisms of metal-free photocatalysts. Then a particular focus is on the rational manipulation of π-conjugation enlargement, charge separation, electronic structures and band structures in the design of metal-free polymeric photocatalysts. Following the design principles, the selection and construction of functional units are discussed, as well as the connecting bonds and dimensions of π-conjugated polymeric photocatalysts. Finally the hot and emerging applications of metal-free polymeric photocatalysts for photocatalytic chemical transformations are summarized. The strategies provide potential avenues to address the challenges of catalyst activity, selectivity and stability in the further development of highly effective metal-free polymeric photocatalysts.

12.
Molecules ; 27(18)2022 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-36144830

RESUMO

We used next-generation QTAIM (NG-QTAIM) to explain the cis-effect for two families of molecules: C2X2 (X = H, F, Cl) and N2X2 (X = H, F, Cl). We explained why the cis-effect is the exception rather than the rule. This was undertaken by tracking the motion of the bond critical point (BCP) of the stress tensor trajectories Tσ(s) used to sample the Uσ-space cis- and trans-characteristics. The Tσ(s) were constructed by subjecting the C1-C2 BCP and N1-N2 BCP to torsions ± θ and summing all possible Tσ(s) from the bonding environment. During this process, care was taken to fully account for multi-reference effects. We associated bond-bending and bond-twisting components of the Tσ(s) with cis- and trans-characteristics, respectively, based on the relative ease of motion of the electronic charge density ρ(rb). Qualitative agreement is found with existing experimental data and predictions are made where experimental data is not available.


Assuntos
Teoria Quântica , Ligação de Hidrogênio
13.
Inorg Chem ; 60(11): 7961-7973, 2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34009980

RESUMO

The evolution of local atomic configuration and macroscopic electrical properties of KNbO3 is investigated in detail using ab initio molecular dynamics simulations within the framework of density functional theory. By analyzing the local off-center displacements of K and Nb atoms, the presence of the crossover of displacive and order-disorder mechanisms in the NbO6 octahedron due to orbital hybridization is found, whereas the K is a completely displacive type due to the nonoriented ionic K-O bond. Besides, the order-disorder behavior of Nb atoms is enhanced with the increase in temperature, especially undergoing the phase transition. The predicted high dielectric constant of KNbO3 confirms the key role of the Nb's order-disorder behavior. We discover that the anomalous increase in dielectric constant in the vicinity of the phase boundary is not only from the transformation of the polarized direction but also from the enhancement of order-disorder contribution in the nonpolarized direction. The high dielectric constant with large spontaneous polarization boosts the piezoelectricity at the orthorhombic-tetragonal phase boundary of 500 K, giving rise to the nearly 100% increase than that of 300 K. A rebonding model is developed to illustrate the origin of high piezoelectricity around the tetragonal ferroelectric phase boundary, and the significance of introducing a tetragonal structure is emphasized for developing high piezoelectricity in the inorganic perovskite ferroelectrics.

14.
J Comput Assist Tomogr ; 45(5): 696-703, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34347707

RESUMO

PURPOSE: The aim of this study was to construct and verify a computed tomography (CT) radiomics model for preoperative prediction of synchronous distant metastasis (SDM) in clear cell renal cell carcinoma (ccRCC) patients. METHODS: Overall, 172 patients with ccRCC were enrolled in the present research. Contrast-enhanced CT images were manually sketched, and 2994 quantitative radiomic features were extracted. The radiomic features were then normalized and subjected to hypothesis testing. Least absolute shrinkage and selection operator (LASSO) was applied to dimension reduction, feature selection, and model construction. The performance of the predictive model was validated through analysis of the receiver operating characteristic curve. Multivariate and subgroup analyses were performed to verify the radiomic score as an independent predictor of SDM. RESULTS: The patients randomized into a training (n = 104) and a validation (n = 68) cohort in a 6:4 ratio. Through dimension reduction using LASSO regression, 9 radiomic features were used for the construction of the SDM prediction model. The model yielded moderate performance in both the training (area under the curve, 0.89; 95% confidence interval, 0.81-0.97) and the validation cohort (area under the curve, 0.83; 95% confidence interval, 0.69-0.95). Multivariate analysis showed that the CT radiomic signature was an independent risk factor for clinical parameters of ccRCC. Subgroup analysis revealed a significant connection between the SDM and radiomic signature, except for the lower pole of the kidney subgroup. CONCLUSIONS: The CT-based radiomics model could be used as a noninvasive, personalized approach for SDM prediction in patients with ccRCC.


Assuntos
Carcinoma de Células Renais/diagnóstico por imagem , Carcinoma de Células Renais/patologia , Neoplasias Renais/diagnóstico por imagem , Neoplasias Renais/patologia , Segunda Neoplasia Primária/diagnóstico , Tomografia Computadorizada por Raios X/métodos , Meios de Contraste , Feminino , Humanos , Rim/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Intensificação de Imagem Radiográfica/métodos
15.
BMC Geriatr ; 21(1): 681, 2021 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-34876057

RESUMO

BACKGROUND: Insomnia is a common sleep disturbance in older adults and is associated with many poor health outcomes. This study aimed to explore factors associated with insomnia in older adult outpatient clinics, and to further analyze the influence of gender on factors associated with insomnia. METHODS: This cross-sectional study was conducted in the outpatient clinics of a tertiary hospital in Southern Taiwan from July to September 2018. A total of 400 consecutive subjects aged 60 years or older were recruited. Insomnia was defined as a score of ≥6 points on the Athens Insomnia Scale (AIS). Socio-demographics, health behaviors and clinical data were collected by face-to-face interview. Multivariable logistic regression was adopted for statistical analysis of the entire sample and stratified by gender. RESULTS: Participants' mean age was 74.74 ± 8.54 years, and the majority (93%) had more than one chronic disease. The prevalence of insomnia accounted for 30% (120/400) of all subjects, with males 22.9% (46/201) and females 37.2% (74/199). Gender, appetite, exercise, depressive symptoms, and sleep-related conditions such as short sleep duration, sleeping pills usage, medium-high risk of obstructive sleep apnea (OSA) and restless leg syndrome (RLS) were factors associated with insomnia in older adults. Exercise, sleeping pills usage, and RLS were independently associated with insomnia only in men, while appetite and medium-high risk of OSA were associated with insomnia in women only. In addition, after further adjusting for covariates, prevalence of the insomnia-related symptoms such as sleep induction, total sleep duration, sleep quality and sleepiness during the day was significantly higher in females than in males. CONCLUSIONS: Insomnia symptoms are highly prevalent among older adults, predominantly females. Significant differences are found between genders in factors associated with insomnia and insomnia-related symptoms. Understanding gender differences may help clinicians to modify associated factors when managing older adults with insomnia.


Assuntos
Apneia Obstrutiva do Sono , Distúrbios do Início e da Manutenção do Sono , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Masculino , Pacientes Ambulatoriais , Distúrbios do Início e da Manutenção do Sono/diagnóstico , Distúrbios do Início e da Manutenção do Sono/epidemiologia , Qualidade do Sono
16.
J Phys Chem A ; 124(6): 1068-1075, 2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-31958227

RESUMO

In the field of electronics, organocatalysts are in high demand for use in the synthesis of clean polymers using solar radiation rather than potentially contaminating metals. Combining theoretical design, simulation, and experiments, this work presents a novel, pyridine-diketopyrrolopyrrole (P-DPP)-based metal-free visible-light organophotoredox catalyst (P-DPP). It is effective in the photocontrolled organocatalytic atom-transfer radical polymerization (O-ATRP) of methyl methacrylate (MMA) and styrene. The use of this catalyst and white light-emitting diode (LED) irradiation produces polymers with a cross-linked feature. In O-ATRP, the P-DPP catalyst has an oxidative quenching catalytic mechanism with an excited-state reductive potential of -1.8 V, fluorescence lifetime of 7.5 ns, and radical-cation oxidative potential of 0.45 V. Through molecular simulation, we found that the adjacent pyridine group is key to reducing the alkyl halide initiator and generating radicals, while the diketopyrrolopyrrole core stabilizes the triplet state of the catalyst through intramolecular charge transfer. The findings related to this novel photoredox catalyst will aid in the search for much more effective organophotoredox catalysts for use in controlled radical polymerization. They will also be of value in the fields of polymer chemistry and physics and in various applications.

17.
Phys Chem Chem Phys ; 21(48): 26515-26524, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31777912

RESUMO

In this work, the electronic and optical properties of one-dimensional (1D) Sb2S3 nanowires (NWs) with different sizes are investigated using first-principles calculations. The indirect-direct band transition of Sb2S3 NWs can be tuned effectively by the NW size and various uniaxial strains. In the Sb2S3 NWs, the quantum confinement effects result in wider bandgaps while the significantly enhanced electron-hole interaction that is expected to produce excitonic bound states generates a bandgap narrowing. The exciton binding energies for the Sb2S3 NWs are predicted by the effective masses of electrons and holes to lie in the range of 0-1 eV, which are larger than that of bulk Sb2S3, suggesting that excitons in Sb2S3 NWs may bind possible defects to promote luminescence. The size-controlled absorption edge blueshift and redshift of Sb2S3 NWs suggest that Sb2S3 NWs may be promising in the applications of nanoscale light emitting devices.

18.
Ophthalmologica ; 241(2): 73-80, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30153680

RESUMO

PURPOSE: To investigate the etiologies and characteristics of choroidal neovascularization (CNV) in young Chinese patients. METHODS: A retrospective review of young Chinese patients (< 50 years of age) with CNV from January 2010 to June 2016 was performed. RESULTS: Of the 501 patients (537 eyes) with CNV, 58.7% were female, and 7.2% had bilateral CNV. The mean age was 35 years. The etiologies were idiopathic CNV (ICNV, 43.9%), pathologic myopia (PM, 21.9%), punctate inner choroidopathy (PIC, 17.4%), polypoidal choroidal vasculopathy (4.4%), multifocal choroiditis with panuveitis (3.6%), and other disorders (8.8%). Five hundred and six CNVs (94.2%) showed a predominantly classic CNV composition on fundus fluorescein angiography (FFA) and 316 CNVs (96.6%) were type 2 CNV on optical coherence tomography (OCT). CONCLUSION: The etiologies of CNV in young Chinese patients were diverse, and ICNV, PM, and PIC were the three most common etiologies. Most CNVs were classic on FFA and type 2 on OCT.


Assuntos
Corioide/diagnóstico por imagem , Neovascularização de Coroide/etiologia , Acuidade Visual , Adolescente , Adulto , Criança , Pré-Escolar , China/epidemiologia , Neovascularização de Coroide/diagnóstico , Neovascularização de Coroide/epidemiologia , Feminino , Angiofluoresceinografia , Fundo de Olho , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Tomografia de Coerência Óptica/métodos , Adulto Jovem
19.
Clin Exp Ophthalmol ; 47(5): 631-637, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30663190

RESUMO

IMPORTANCE: Chorodial structure in subtypes of polypoidal choroidal vasculopathy (PCV). BACKGROUND: To evaluate choroidal vascularity in the eyes of patients with PCV with and without choroidal vascular hyperpermeability (CVH). DESIGN: A hospital-based retrospective study. PARTICIPANTS: Fifty-eight PCV patients (28 with CVH; 30 without CVH) and 30 normal controls were included in this study. METHODS: All study subjects underwent spectral-domain optical coherence tomography with enhanced depth imaging, and the choroidal images were binarized into the luminal area and stromal area. MAIN OUTCOME MEASURES: Choroidal vascularity index (CVI) and subfoveal choroidal thickness (SFCT). RESULTS: Compared to normal controls, patients with PCV showed no obvious difference in SFCT (P = 0.510), but significantly lower CVI (P = 0.003). Among PCV patients, the CVI in eyes with CVH was significantly greater than that in those without CVH (65.78 ± 4.70 vs 62.28 ± 3.90; P = 0.002), and a significant difference in SFCT was also found between the two subtypes of PCV (340.8 ± 89.2 vs 250.4 ± 67.7; P < 0.001). CONCLUSIONS AND RELEVANCE: PCV eyes with CVH have a greater CVI and a thicker SFCT than those without CVH. The significant differences in choroidal vascularity between the two subtypes of PCV may broaden our understanding of the pathogenesis of this disease and contribute to significant improvements in treatment.


Assuntos
Corioide/irrigação sanguínea , Corioide/patologia , Neovascularização de Coroide/diagnóstico por imagem , Pólipos/diagnóstico por imagem , Tomografia de Coerência Óptica , Idoso , Permeabilidade Capilar , Corioide/diagnóstico por imagem , Neovascularização de Coroide/fisiopatologia , Corantes/administração & dosagem , Feminino , Angiofluoresceinografia , Humanos , Verde de Indocianina/administração & dosagem , Masculino , Pessoa de Meia-Idade , Pólipos/fisiopatologia , Estudos Retrospectivos , Microscopia com Lâmpada de Fenda , Acuidade Visual/fisiologia
20.
Int Ophthalmol ; 39(5): 987-990, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-29594794

RESUMO

PURPOSE: To record the coexistence of polypoidal choroidal vasculopathy (PCV) with other rare fundus diseases in a Chinese population. METHOD: In this retrospective hospital-based study, a chart review of 861 patients with newly diagnosed PCV was performed. The clinical features of rare fundus comorbidities of PCV were recorded. RESULTS: Five eyes of 5 patients aged 63.4 ± 11.22 years (0.58%) had PCV coexisting with other fundus diseases in the same eye. Of the 5 PCV patients, 2 (0.23%) had myelinated nerve fiber, 2 (0.23%) had branch retinal vein occlusion, and 1 (0.12%) had retinal angiomatous proliferation. CONCLUSION: We reported rare fundus comorbidities of PCV in a large Chinese cohort. These comorbidities included myelinated nerve fiber, branch retinal vein occlusion and retinal angiomatous proliferation. The combination might constitute an accidental occurrence.


Assuntos
Doenças da Coroide/diagnóstico , Corioide/irrigação sanguínea , Degeneração Macular/epidemiologia , Fibras Nervosas Mielinizadas/patologia , Pólipos/diagnóstico , Oclusão da Veia Retiniana/epidemiologia , Acuidade Visual , Idoso , Idoso de 80 Anos ou mais , China/epidemiologia , Doenças da Coroide/epidemiologia , Comorbidade , Feminino , Angiofluoresceinografia , Fundo de Olho , Humanos , Macula Lutea/patologia , Degeneração Macular/diagnóstico , Masculino , Pessoa de Meia-Idade , Oftalmoscopia , Pólipos/epidemiologia , Doenças Raras , Células Ganglionares da Retina/patologia , Oclusão da Veia Retiniana/diagnóstico , Estudos Retrospectivos , Tomografia de Coerência Óptica
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