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1.
Plant Cell ; 34(5): 1804-1821, 2022 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-35080617

RESUMO

Plant viruses with densely packed genomes employ noncanonical translational strategies to increase the coding capacity for viral function. However, the diverse translational strategies used make it challenging to define the full set of viral genes. Here, using tomato yellow leaf curl Thailand virus (TYLCTHV, genus Begomovirus) as a model system, we identified genes beyond the annotated gene sets by experimentally profiling in vivo translation initiation sites (TISs). We found that unanticipated AUG TISs were prevalent and determined that their usage involves alternative transcriptional and/or translational start sites and is associated with flanking mRNA sequences. Specifically, two downstream in-frame TISs were identified in the viral gene AV2. These TISs were conserved in the begomovirus lineage and led to the translation of different protein isoforms localized to cytoplasmic puncta and at the cell periphery, respectively. In addition, we found translational evidence of an unexplored gene, BV2. BV2 is conserved among TYLCTHV isolates and localizes to the endoplasmic reticulum and plasmodesmata. Mutations of AV2 isoforms and BV2 significantly attenuated disease symptoms in tomato (Solanum lycopersicum). In conclusion, our study pinpointing in vivo TISs untangles the coding complexity of a plant viral genome and, more importantly, illustrates the biological significance of the hidden open-reading frames encoding viral factors for pathogenicity.


Assuntos
Begomovirus , Solanum lycopersicum , Begomovirus/genética , Genoma Viral , Solanum lycopersicum/genética , Fases de Leitura Aberta/genética , Filogenia , Doenças das Plantas/genética
2.
Br J Nutr ; 131(2): 276-285, 2024 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-37642137

RESUMO

The benefits of branched-chain amino acid (BCAA) administration after hepatic intervention in patients with liver diseases remain unclear. We conducted a systematic review and meta-analysis to evaluate the effects of BCAA on patients undergoing hepatectomy, trans-arterial embolisation and radiofrequency ablation. Relevant randomised controlled trials (RCT) were obtained from PubMed, EMBASE and Cochrane Library databases. A meta-analysis was performed to calculate the pooled effect size by using random-effects models. The primary outcomes were survival and tumour recurrence. The secondary outcomes were hospital stay, nutrition status, biochemistry profile, complication rate of liver treatment and adverse effect of BCAA supplementation. In total, eleven RCT involving 750 patients were included. Our meta-analysis showed no significant difference in the rates of tumour recurrence and overall survival between the BCAA and control groups. However, the pooled estimate showed that BCAA supplementation in patients undergoing hepatic intervention significantly increased serum albumin (mean difference (MD): 0·11 g/dl, 95 % CI: 0·02, 0·20; 5 RCT) at 6 months and cholinesterase level (MD: 50·00 U/L, 95 % CI: 21·08, 78·92; 1 RCT) at 12 months and reduced ascites incidence (risk ratio: 0·39, 95 % CI: 0·21, 0·71; 4 RCT) at 12 months compared with the control group. Additionally, BCAA administration significantly increased body weight at 6 months and 12 months and increased arm circumference at 12 months. In conclusion, BCAA supplementation significantly improved the liver function, reduced the incidence of ascites and increased body weight and arm circumference. Thus, BCAA supplementation may beneficial for selected patients undergoing liver intervention.


Assuntos
Aminoácidos de Cadeia Ramificada , Ascite , Humanos , Ascite/induzido quimicamente , Ascite/metabolismo , Ascite/patologia , Aminoácidos de Cadeia Ramificada/uso terapêutico , Recidiva Local de Neoplasia/induzido quimicamente , Recidiva Local de Neoplasia/metabolismo , Recidiva Local de Neoplasia/patologia , Fígado/metabolismo , Suplementos Nutricionais , Peso Corporal
3.
Acta Derm Venereol ; 104: adv40053, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38916178

RESUMO

Patients with rosacea commonly experience stigmatization, which induces stress and thereby exacerbates their symptoms. Given the strong effects of rosacea on health-related quality of life (HRQoL), addressing the physical and psychosocial aspects of rosacea is essential. To examine the effects of rosacea on HRQoL, we conducted a systematic review and meta-analysis involving real-world data. PubMed, EMBASE, and the Cochrane Library were searched, and randomized controlled trials (RCTs), cross-sectional studies, and case series evaluating the HRQoL of patients with rosacea were included. HRQoL assessment tools such as the Dermatology Life Quality Index (DLQI) and Rosacea-Specific Quality-of-Life Questionnaire (RosaQoL) were used. Data on 13,453 patients were retrieved from 52 eligible studies: 4 RCTs, 15 case series, and 33 cross-sectional studies. Compared with healthy controls, patients with rosacea had significantly lower DLQI scores (standardized mean difference [SMD] = -1.09, 95% confidence interval [CI] = -0.81 to -1.37). The DLQI scores after treatment were higher than those before treatment (SMD = -1.451, 95% CI = -1.091 to -1.810). The pooled estimates for the overall DLQI and RosaQoL scores were 8.61 and 3.06, respectively. In conclusion, patients with rosacea have lower HRQoL compared with healthy individuals, and treatment for rosacea improves their HRQoL.


Assuntos
Qualidade de Vida , Rosácea , Rosácea/psicologia , Humanos , Feminino , Inquéritos e Questionários , Masculino , Adulto , Pessoa de Meia-Idade , Efeitos Psicossociais da Doença , Resultado do Tratamento
4.
J Am Chem Soc ; 144(32): 14897-14906, 2022 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-35924834

RESUMO

Two-dimensional (2D) Dion-Jacobson (DJ) perovskite solar cells (PSCs), despite their advantage in versatility of n-layer variation, are subject to poor photovoltaic efficiency, particularly in the fill factor (FF), compared to their three-dimensional counterparts. To enhance the performance of DJ PSCs, the process of growing crystals and hence the corresponding morphology of DJ perovskites are of prime importance. Herein, we report the fast nonisothermal (NIT) crystallization protocol that is previously unrecognized for 2D perovskites to significantly improve the morphology, orientation, and charge transport of the DJ perovskite films. Comprehensive mechanistic studies reveal that the NIT effect leads to the secondary crystallization stage, forming network-like channels that play a vital role in the FF's leap-forward improvement and hence the DJ PSC's performance. As a whole, the NIT crystallized PSCs demonstrate a high power conversion efficiency and an FF of up to 19.87 and 86.16%, respectively. This research thus provides new perspectives to achieve highly efficient DJ PSCs.


Assuntos
Compostos de Cálcio , Óxidos , Cristalização , Titânio
5.
BMC Nurs ; 21(1): 257, 2022 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-36123726

RESUMO

BACKGROUND: Aromatherapy is effective in treating pain; however, aromatherapy is not offered in formal nursing education in Taiwan. This study designed aromatherapy training courses for nurses using the flipped teaching approach and explored the effectiveness of the method, which can serve as a reference for future aromatherapy courses. METHODS: A quasi-experimental design and convenience sampling were adopted. The participants were nurses who had been employed for over one year in two hospitals in Taiwan. Forty nurses were included in the experimental and control groups. The intervention of this study was performed in February 2020. Nurses in the control group received one hour of introduction to the use of aromatherapy in pain management. This class was delivered using the traditional teaching method, during which a researcher served as the lecturer. Nurses in the experimental group received a 2.5-h flipped teaching course on aromatherapy. Two weeks before classroom activities, the nurses in the experimental group watched a 30-min aromatherapy concept video on an e-learning teaching platform. Thereafter, the nurses participated in two hours of classroom teaching in both groups. The course design included group discussions, mind mapping, case discussion, practice with essential oils, and do-it-yourself essential oil preparation. RESULTS: Pre- and post-test knowledge and self-efficacy in aromatherapy were assessed. There were no significant differences in the pre-test knowledge and self-efficacy scores between the two groups. The test was analyzed using a generalized estimating equation. Post-test knowledge and self-efficacy results showed that the change in scores in the experimental group was significantly better than that in the control group, indicating that flipped teaching improved the participants' knowledge and self-efficacy in aromatherapy. CONCLUSIONS: This study confirmed that flipped teaching was effective in helping nursing personnel learn aromatherapy. Implementation of aromatherapy by nurses in clinical practice and its impact on patient care should be further assessed.

6.
Inorg Chem ; 60(21): 16266-16272, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34672549

RESUMO

A tricoordinate borenium ion has received considerable attention in recent years for its applications in Lewis acid catalysis. Over the years, asymmetric catalysis mediated by a chiral borenium ion has also been developed. To stabilize the electron-deficient boron atom, a series of chloroborane masked borenium ions featuring the symmetrical [B-Cl-B]+ linkage are prepared and utilized as the catalyst for the enantioselective Diels-Alder cycloaddition of cyclopentadiene and 2,2,2-trifluoroethyl acrylate. The presence of a Cp* ligand is critical in realizing the cyclic diboron compounds, and the stability of the resulting [B-Cl-B]+ cation is dependent on the steric bulkiness of the oxazolidinone moiety. The stereoselectivity of the Diels-Alder cycloaddition is controlled by the substituents of the chiral oxazolidinone ligand and could be further improved via the coordination of SnCl4 at the bridging chloride of the [B-Cl-B]+ cation.

7.
Angew Chem Int Ed Engl ; 60(14): 7866-7872, 2021 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-33403749

RESUMO

2D perovskites with chemical formula A'2 An-1 Bn X3n+1 have recently attracted considerable attention due to their tunable optical and electronic properties, which can be attained by varying the chemical composition. While high color-purity emitting perovskite nanomaterials have been accomplished through changing the halide composition, the preparation of single-phase, specific n-layer 2D perovskite nanomaterials is still pending because of the fast nucleation process of nanoparticles. We demonstrate a facile, rational and efficacious approach to synthesizing single-phase 2D perovskite nanoplates with a designated n number for both lead- and tin-based perovskites through kinetic control. Casting carboxylic acid additives in the reaction medium promotes selective formation of the kinetic product-multilayer 2D perovskite-in preference to the single-layer thermodynamic product. For the n-specific layered 2D perovskites, decreasing the number of octahedral layers per inorganic sheet leads to an increase of photoluminescence energy, radiative decay rate, and a significant boost in photostability.

8.
Angew Chem Int Ed Engl ; 60(39): 21434-21440, 2021 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-34319649

RESUMO

Through the incorporation of various halogen-substituted chiral organic cations, the effects of chiral molecules on the chiroptical properties of hybrid organic-inorganic perovskites (HOIPs) are investigated. Among them, the HOIP having a Cl-substituted chiral cation exhibits the highest circular dichroism (CD) and circular polarized luminescence (CPL) intensities, indicating the existence of the largest rotatory strength, whereas the F-substituted HIOP shows the weakest intensities. The observed modulation can be correlated to the varied magnetic transition dipole of HOIPs, which is sensitive to the d-spacing between inorganic layers and the halogen-halogen interaction between organic cations and the inorganic sheets. These counteracting effects meet the optimal CD and CPL intensity with chlorine substitution, rendering the rotatory strength of HOIPs arranged in the order of (ClMBA)2 PbI4 >(BrMBA)2 PbI4 >(IMBA)2 PbI4 >(MBA)2 PbI4 >(FMBA)2 PbI4 .

9.
Small ; 16(19): e2000903, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32309909

RESUMO

Tin-based perovskite, which exhibits narrower bandgap and comparable photophysical properties to its lead analogs, is one of the most forward-looking lead-free semiconductor materials. However, the poor oxidative stability of tin perovskite hinders the development toward practical application. In this work, the effect of pseudohalide anions on the stability and emission properties of single-layer 2D tin perovskite nanoplates with chemical formula TEA2 SnI4 (TEA = 2-thiophene-ethylammonium) is reported. The results reveal that ammonium thiocyanate (NH4 SCN) is the most effective additive in enhancing the stability and photoluminescence quantum yield of 2D TEA2 SnI4 (23 ± 3%). X-Ray photoelectron spectroscopic investigations on the thiocyanate passivated TEA2 SnI4 nanoplate show less than a 1% increase of Sn4+ signal upon 30 min exposure to air under ambient conditions (298 K, humidity ≈70%). Furthermore, no noticeable decrease in emission intensity of the nanoplate is observed after 20 h in air. The SCN- passivation during the growth stage of TEA2 SnI4 is proposed to play a crucial role in preventing the oxidation of Sn2+ and hence boosts both stability and photoluminescence yield of tin perovskite nanoplates.

10.
Inorg Chem ; 59(7): 4468-4474, 2020 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-32193926

RESUMO

The coordination chemistry of cationic divalent pnictogen ligands, such as nitrenium and phosphenium, has been well-explored in recent years. However, corresponding studies of a heavier congener, stibenium ion, are rare. To better facilitate a Sb+-metal interaction, a tridentate P-Sb+-P ligand with two phosphine buttresses was designed and synthesized, and its coordination chemistry toward late transition metals was investigated. The stibenium ligand was delivered as an activated P(SbCl)P-AgOTf complex (2) that releases AgCl and the P-Sb+-P ligand upon the treatment with transition metals. Reacting 2 with Rh(I) and Ir(I) metals yielded the anticipated stibenium-transition-metal complexes [(Rh(COD)Cl)2(µ-PSb+P)] OTf ([3][OTf]) and [(Ir(COD)Cl)2(µ-PSb+P)] OTf ([4][OTf]). The M-Sb+-M bridging structure was confirmed by single-crystal X-ray crystallography, and the bonding situation was examined computationally. Theoretical studies revealed the presence of three-center delocalized M-Sb+-M bonding interactions in [3][OTf] and [4][OTf].

11.
J Am Chem Soc ; 141(26): 10324-10330, 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31244186

RESUMO

Tin perovskite nanomaterial is one of the promising candidates to replace organic lead halide perovskites in lighting applications. Unfortunately, the performance of tin-based systems is markedly inferior to those featuring toxic Pb salts. In an effort to improve the emission quantum efficiency of nanoscale 2D layered tin iodide perovskites through fine-tuning the electronic property of organic ammonium salts, we came to unveil the relationship between dielectric confinement and the photoluminescent properties of tin iodide perovskite nanodisks. Our results show that increasing the dielectric contrast for organic versus inorganic layers leads to a bathochromic shift in emission peak wavelength, a decrease of exciton recombination time, and importantly a significant boost in the emission efficiency. Under optimized conditions, a leap in emission quantum yield to a record high 21% was accomplished for the nanoscale thienylethylammonium tin iodide perovskite (TEA2SnI4). The as-prepared TEA2SnI4 also possessed superior photostability, showing no sign of degradation under continuous irradiation (10 mW/cm2) over a period of 120 h.

12.
Inorg Chem ; 57(18): 11732-11737, 2018 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-30179003

RESUMO

Although boron-containing radicals are promising materials for molecular electronic devices, the electronic effect of the σ-donating yet π-accepting boron center on the stability of open-shell species has been less discussed. In this work, the role of a tricoordinate boron center in π-conjugated radicals was explored through electron paramagnetic resonance measurement of several boron-linked bisphenol radicals and diradicals. Replacing the bridging methine fragment of a neutral Galvinoxyl radical with an arylboryl group led to the corresponding boron-linked radical anion that requires excessive steric protection at the boron center to be persistent in solution. Experimental and theoretical investigations revealed that the introduction of boron would diminish the quinoidal character of the phenoxyl radical and increase both the electrophilicity and nucleophilicity of the open-shell species. Therefore, it is important to consider the steric protection of the boron center in boron-containing π-conjugated organic radicals.

13.
Inorg Chem ; 56(17): 10543-10548, 2017 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-28820245

RESUMO

1,2-Boryl migration of N-boryl N-heterocyclic carbene to 2-boryl imidazole is proposed to proceed through generation and recombination of two radical intermediates, namely, a neutral diarylboron radical and a N-heterocyclic carbene radical. Crossover experiments suggest that these two radical species are stable enough to escape solvent cages and recombine intermolecularly. The presence of radical intermediates is further supported by spin trapping experiments. Besides, the coordination of Li+ cation is found to be critical for the stability of the NHC radical.

14.
Inorg Chem ; 55(23): 12427-12434, 2016 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-27934439

RESUMO

The effect of a ligand on the electron deficiency and Lewis acidity of the Cp*-substituted boron dication has been investigated experimentally and theoretically. In addition to the reported IMes- and N-heterocyclic olefin (NHO)-stabilized boron dications, the related cyclic alkylamino carbene (CAAC)-coordinated boron mono- and dications have also been synthesized and structurally characterized. An electrochemical study of dications [3a-3c]2+ confirms the higher electron deficiency of the dicationic system than the related boron monocations. Moreover, the presence of a π-acidic CAAC ligand is critical for realizing stable radical species generated from the chemical reduction of boron cations. The nature of the axial ligand also significantly affects the selectivity of the hydride addition reaction of boron dications. While bulky superhydride reacts with [3a-3c]2+ in the same manner to give the cyclic boreniums, [BH4]- attacks three different electrophilic sites of boron dications: the sp2 carbon of Cp* of the IMes-coordinated system ([3a]2+), the central boron atom of the NHO-stabilized analogue ([3b]2+), and the ylidene carbon of the CAAC-containing boron dication ([3c]2+).

15.
Langmuir ; 30(1): 140-8, 2014 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-24380625

RESUMO

We have measured the effect of DC and AC electric fields (up to 15 kV/m) on the force between two 15 µm radius BaTiO3 glass spheres in air in the separation range 0-6 µm. These fields cause attractive forces that are much greater than van der Waals forces and therefore can be used to control and separate particles in many applications. The attractive force has a static and dynamic component. The static forces are about 9000 times greater than the prediction by multiple-moment methods but otherwise follow the expected trends for polarization forces. For example, the force scales with the square of the field, is constant over a range of field frequencies, and has the same force-separation profile predicted by multipole-moment methods. In contrast to the point dipole approximation, which depends inversely on the fourth power of the distance between the centers of the spheres, the measured static force approximately follows a power law, F ∝ -s(-0.75), that depends on the separation, s, between the nearest points of the spheres. This power law is very similar to the prediction by multipole-moment method for separations less than 1/10th of the radius. The dynamic response force occurs at twice the frequency of the drive and has a similar amplitude to the static force. The electrical field also causes a large increase in adhesion.

16.
17.
Angew Chem Int Ed Engl ; 53(24): 6237-40, 2014 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-24782406

RESUMO

Chemical reduction of a hydroxyphenyl-substituted borane triggers a sequential electron- and intramolecular hydrogen-atom-transfer process to afford a hydridoborate phenoxide dianion. On the other hand, hydrogen-atom abstraction of the borane leads to the isolation of a neutral borylated phenoxyl radical, which can be transformed to the corresponding benzoquinone borataalkene derivative by reduction with cobaltocene.

18.
bioRxiv ; 2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37781607

RESUMO

Endocytosis and lysosomal trafficking of cell surface receptors can be triggered by interaction with endogenous ligands. Therapeutic approaches such as LYTAC1,2 and KineTAC3, have taken advantage of this to target specific proteins for degradation by fusing modified native ligands to target binding proteins. While powerful, these approaches can be limited by possible competition with the endogenous ligand(s), the requirement in some cases for chemical modification that limits genetic encodability and can complicate manufacturing, and more generally, there may not be natural ligands which stimulate endocytosis through a given receptor. Here we describe general protein design approaches for designing endocytosis triggering binding proteins (EndoTags) that overcome these challenges. We present EndoTags for the IGF-2R, ASGPR, Sortillin, and Transferrin receptors, and show that fusing these tags to proteins which bind to soluble or transmembrane protein leads to lysosomal trafficking and target degradation; as these receptors have different tissue distributions, the different EndoTags could enable targeting of degradation to different tissues. The modularity and genetic encodability of EndoTags enables AND gate control for higher specificity targeted degradation, and the localized secretion of degraders from engineered cells. The tunability and modularity of our genetically encodable EndoTags should contribute to deciphering the relationship between receptor engagement and cellular trafficking, and they have considerable therapeutic potential as targeted degradation inducers, signaling activators for endocytosis-dependent pathways, and cellular uptake inducers for targeted antibody drug and RNA conjugates.

19.
Chemistry ; 18(45): 14292-304, 2012 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-23019113

RESUMO

Herein, we report the synthesis of boroles that are linked by a conjugated phenylene spacer. The characterization of these compounds was completed by NMR and UV/Vis spectroscopy, as well as X-ray crystal diffraction. Furthermore, the coordination behavior of these oligoboroles towards five electronically and sterically disparate pyridine derivatives was studied and revealed fundamental differences in the properties of the resulting adducts. The experimental results were supported by density functional theory (DFT) calculations that showed a charge-transfer effect upon formation of the pyridine-4-carbonitrile adduct. By chemical reduction of a tris(borolyl)-substituted benzene derivative, a hexaanion was isolated as a result of a two-electron reduction of each borolyl moiety. The interaction of the borolyl units through the aryl spacer, and the possible increase of the Lewis acidity due to the conjugation of the borolyl moieties, were investigated by base transfer reactions.

20.
Chemistry ; 18(37): 11732-46, 2012 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-22886835

RESUMO

Herein, we report on the synthesis of ferrocenylborole [Fc(BC(4)Ph(4))(2)] featuring two borole moieties in the 1,1'-positions. The results of NMR and UV/Vis spectroscopy and X-ray diffraction studies provided conclusive evidence for the enhanced Lewis acidity of the boron centers resulting from the conjugation of two borole fragments. This finding was further validated by the reaction of [Fc(BC(4)Ph(4))(2)] and the 4-Me-NC(5)H(4) adduct of monoborole [Fc(BC(4)Ph(4))], which led to quantitative transfer of the Lewis base. The coordination chemistry of ferrocenylboroles was further studied by examining their reactivity towards several pyridine bases. Accordingly, the strong Lewis acidity of boroles in general was nicely demonstrated by the reaction of [Fc(BC(4)Ph(4))] with 4,4'-bipyridine. Unlike common borane derivatives such as [FcBMe(2)], which only forms a 2:1 adduct, we also succeeded in the isolation of a 1:1 Lewis acid/base adduct, with one nitrogen donor of 4,4'-bipyridine remaining uncoordinated. In addition, the reduction chemistry of ferrocenylboroles [Fc(BC(4)Ph(4))] and [Fc(BC(4)Ph(4))(2)] has been studied in more detail. Thus, depending on the reducing agent and the reaction stoichiometry, chemical reduction of [Fc(BC(4)Ph(4))] might lead to the migration of the borolediide fragment towards the iron center, affording dianions with either η(5)-coordinated C(5)H(4) or η(5)-coordinated BC(4)Ph(4) moieties. In contrast, no evidence for borole migration was observed during reduction of bisborole [Fc(BC(4)Ph(4))(2)], which readily resulted in the formation of the corresponding tetraanion. Finally, our efforts to further enhance the borole ratio in ferrocenylboroles aiming at the synthesis of [Fc(BC(4)Ph(4))(4)] failed and, instead, generated an uncommon ansa-ferrocene containing two borole fragments in the 1,1'-positions and a B(2)C(4) ansa-bridge.


Assuntos
Compostos de Boro/química , Compostos Ferrosos/química , Metalocenos , Modelos Moleculares , Estrutura Molecular
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