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1.
Braz. j. biol ; 84: e252364, 2024. graf
Artigo em Inglês | MEDLINE, LILACS, VETINDEX | ID: biblio-1355885

RESUMO

Abstract Understanding morphological and physiological changes under different light conditions in native fruit species in juveniles' stage is important, as it indicate the appropriate environment to achieve vigorous saplings. We aimed to verify growth and morphophysiological changes under shade gradient in feijoa (Acca sellowiana (O. Berg) Burret) to achieve good quality saplings adequate to improve cultivation in orchards. The saplings were grown for twenty-one-month under four shading treatments (0%, 30%, 50%, and 80%). Growth, photosynthetic pigments, gas exchanges, chlorophyll fluorescence, and leaf anatomy parameters were evaluated. Saplings under full sun and 30% shade had higher height and diameter growth and dry mass accumulation due to higher photosynthesis rate. As main acclimatization mechanisms in feijoa saplings under 80% shade were developed larger leaf area, reduced leaf blade thickness, and enhanced quantum yield of photosystem II. Even so, the net CO2 assimilation and the electron transport rate was lower and, consequently, there was a restriction on the growth and dry mass in saplings under deep shade. Therefore, to obtain higher quality feijoa saplings, we recommend that it be carried out in full sun or up to 30% shade, to maximize the sapling vigor in nurseries and, later, this light environment can also be used in orchards for favor growth and fruit production.


Resumo A verificação de mudanças morfológicas e fisiológicas sob diferentes condições luminosas em espécies frutíferas nativas em estágio juvenil é importante, uma vez que indicam o ambiente adequado para a formação de mudas com alto vigor. Objetivou-se verificar o crescimento e as alterações morfofisiológicas sob gradiente de sombreamento em mudas de feijoa (Acca sellowiana (O. Berg) Burret) para obter mudas de boa qualidade, adequadas para fomentar os plantios da espécie em pomares. As mudas foram cultivadas por vinte e um meses sob quatro tratamentos de sombreamento (0%, 30%, 50% e 80%). Foram avaliados parâmetros de crescimento, pigmentos fotossintéticos, trocas gasosas, fluorescência da clorofila e anatomia foliar. Mudas a pleno sol e 30% de sombra apresentaram maior crescimento em altura, diâmetro e acúmulo de massa seca, devido à maior taxa de fotossíntese. Como principais mecanismos de aclimatação sob 80% de sombra, as mudas desenvolveram maior área foliar, redução da espessura do limbo foliar e aumento do rendimento quântico do fotossistema II. Mesmo assim, a assimilação líquida de CO2 e a taxa de transporte de elétrons foram menores e, consequentemente, houve restrição ao crescimento e acúmulo de massa seca das mudas no maior nível de sombreamento. Portanto, para a obtenção de mudas de feijoa de maior qualidade, recomendamos que seja realizada a pleno sol ou até 30% de sombra, para maximizar o vigor das mudas em viveiros e, posteriormente, este ambiente de luz também pode ser utilizado em pomares para favorecer o crescimento e a produção de frutos.


Assuntos
Myrtaceae , Feijoa , Fotossíntese , Folhas de Planta , Aclimatação , Luz
2.
J Integr Plant Biol ; 64(2): 564-591, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34962073

RESUMO

Photosynthesis started to evolve some 3.5 billion years ago CO2 is the substrate for photosynthesis and in the past 200-250 years, atmospheric levels have approximately doubled due to human industrial activities. However, this time span is not sufficient for adaptation mechanisms of photosynthesis to be evolutionarily manifested. Steep increases in human population, shortage of arable land and food, and climate change call for actions, now. Thanks to substantial research efforts and advances in the last century, basic knowledge of photosynthetic and primary metabolic processes can now be translated into strategies to optimize photosynthesis to its full potential in order to improve crop yields and food supply for the future. Many different approaches have been proposed in recent years, some of which have already proven successful in different crop species. Here, we summarize recent advances on modifications of the complex network of photosynthetic light reactions. These are the starting point of all biomass production and supply the energy equivalents necessary for downstream processes as well as the oxygen we breathe.


Assuntos
Luz , Fotossíntese
3.
J Biomed Opt ; 27(8)2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35534924

RESUMO

SIGNIFICANCE: Monte Carlo (MC) methods have been applied for studying interactions between polarized light and biological tissues, but most existing MC codes supporting polarization modeling can only simulate homogeneous or multi-layered domains, resulting in approximations when handling realistic tissue structures. AIM: Over the past decade, the speed of MC simulations has seen dramatic improvement with massively parallel computing techniques. Developing hardware-accelerated MC simulation algorithms that can accurately model polarized light inside three-dimensional (3D) heterogeneous tissues can greatly expand the utility of polarization in biophotonics applications. APPROACH: Here, we report a highly efficient polarized MC algorithm capable of modeling arbitrarily complex media defined over a voxelated domain. Each voxel of the domain can be associated with spherical scatters of various radii and densities. The Stokes vector of each simulated photon packet is updated through photon propagation, creating spatially resolved polarization measurements over the detectors or domain surface. RESULTS: We have implemented this algorithm in our widely disseminated MC simulator, Monte Carlo eXtreme (MCX). It is validated by comparing with a reference central-processing-unit-based simulator in both homogeneous and layered domains, showing excellent agreement and a 931-fold speedup. CONCLUSION: The polarization-enabled MCX offers biophotonics community an efficient tool to explore polarized light in bio-tissues, and is freely available at http://mcx.space/.


Assuntos
Fótons , Software , Algoritmos , Simulação por Computador , Luz , Método de Monte Carlo
4.
Sci Rep ; 12(1): 7622, 2022 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-35538090

RESUMO

The photokinetic behaviour of drugs driven by polychromatic light is an area of pharmaceutics that has not received a lot of attention. Most often, such photokinetic data is treated by thermal kinetic models (i.e., the classical 0th-, 1st- or 2nd-order equations). Such models were not analytically derived from the rate-laws of the photodegradation reactions. Polychromatic light kinetic modelling is hence of importance, as a means to providing adequate toolkits and metrics. This paper aims at proposing two reliable drug-actinometers useful for polychromatic UVA range. The general actinometric methodology offered here is also useful for any drugs/materials obeying a primary photoprocess where both reactant and photoproduct absorb the incident light, of the [Formula: see text] type. The present method has been consolidated by the η-order kinetics. This framework further demonstrated the lamp-specificity of actinometers. Overall, Dacarbazine and Nifedipine photodegradations obeyed η-order kinetics, and stand as effective actinometers that can be recommended for the ICH Q1b photostability testing.


Assuntos
Dacarbazina , Nifedipino , Cinética , Luz , Fotólise , Raios Ultravioleta
5.
Sci Rep ; 12(1): 7660, 2022 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-35538111

RESUMO

We present a particle-in-cell (PIC) analysis of terahertz (THz) radiation by ultrafast plasma currents driven by relativistic-intensity laser pulses. We show that, while the I0 [Formula: see text] product of the laser intensity I0 and the laser wavelength λ0 plays the key role in the energy scaling of strong-field laser-plasma THz generation, the THz output energy, WTHz, does not follow the I0 [Formula: see text] scaling. Its behavior as a function of I0 and λ0 is instead much more complex. Our two- and three-dimensional PIC analysis shows that, for moderate, subrelativistic and weakly relativistic fields, WTHz(I0 [Formula: see text]) can be approximated as (I0λ02)α, with a suitable exponent α, as a clear signature of vacuum electron acceleration as a predominant physical mechanism whereby the energy of the laser driver is transferred to THz radiation. For strongly relativistic laser fields, on the other hand, WTHz(I0 [Formula: see text]) closely follows the scaling dictated by the relativistic electron laser ponderomotive potential [Formula: see text], converging to WTHz ∝ [Formula: see text] for very high I0, thus indicating the decisive role of relativistic ponderomotive charge acceleration as a mechanism behind laser-to-THz energy conversion. Analysis of the electron distribution function shows that the temperature Te of hot laser-driven electrons bouncing back and forth between the plasma boundaries displays the same behavior as a function of I0 and λ0, altering its scaling from (I0λ02)α to that of [Formula: see text], converging to WTHz ∝ [Formula: see text] for very high I0. These findings provide a clear physical picture of THz generation in relativistic and subrelativistic laser plasmas, suggesting the THz yield WTHz resolved as a function of I0 and λ0 as a meaningful measurable that can serve as a probe for the temperature Te of hot electrons in a vast class of laser-plasma interactions. Specifically, the α exponent of the best (I0λ02)α fit of the THz yield suggests a meaningful probe that can help identify the dominant physical mechanisms whereby the energy of the laser field is converted to the energy of plasma electrons.


Assuntos
Lasers , Radiação Terahertz , Aceleração , Elétrons , Luz
6.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 39(2): 370-379, 2022 Apr 25.
Artigo em Chinês | MEDLINE | ID: mdl-35523559

RESUMO

There is a shared problem in current optical imaging technologies of how to obtain the optical parameters of biological tissues with complex profiles. In this work, an imaging system for obtaining the optical parameters of biological tissues with complex profile was presented. Firstly, Fourier transformation profilometry was used for obtaining the profile information of biological tissues, and then the difference of incident light intensity at different positions on biological tissue surface was corrected with the laws of illumination, and lastly the optical parameters of biological tissues were achieved with the spatial frequency domain imaging technique. Experimental results indicated the proposed imaging system could obtain the profile information and the optical parameters of biological tissues accurately and quickly. For the slab phantoms with height variation less than 30 mm and angle variation less than 40º, the maximum relative errors of the profile uncorrected optical parameters were 46.27% and 72.18%, while the maximum relative errors of the profile corrected optical parameters were 6.89% and 10.26%. Imaging experiments of a face-like phantom and a human's prefrontal lobe were performed respectively, which demonstrated the proposed imaging system possesses clinical application value for the achievement of the optical parameters of biological tissues with complex profiles. Besides, the proposed profile corrected method can be used to combine with the current optical imaging technologies to reduce the influence of the profile information of biological tissues on imaging quality.


Assuntos
Diagnóstico por Imagem , Luz , Humanos , Imagem Óptica , Imagens de Fantasmas
7.
Annu Rev Plant Biol ; 73: 617-648, 2022 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35595290

RESUMO

Photosynthesis is an important remaining opportunity for further improvement in the genetic yield potential of our major crops. Measurement, analysis, and improvement of leaf CO2 assimilation (A) have focused largely on photosynthetic rates under light-saturated steady-state conditions. However, in modern crop canopies of several leaf layers, light is rarely constant, and the majority of leaves experience marked light fluctuations throughout the day. It takes several minutes for photosynthesis to regain efficiency in both sun-shade and shade-sun transitions, costing a calculated 10-40% of potential crop CO2 assimilation. Transgenic manipulations to accelerate the adjustment in sun-shade transitions have already shown a substantial productivity increase in field trials. Here, we explore means to further accelerate these adjustments and minimize these losses through transgenic manipulation, gene editing, and exploitation of natural variation. Measurement andanalysis of photosynthesis in sun-shade and shade-sun transitions are explained. Factors limiting speeds of adjustment and how they could be modified to effect improved efficiency are reviewed, specifically nonphotochemical quenching (NPQ), Rubisco activation, and stomatal responses.


Assuntos
Dióxido de Carbono , Luz Solar , Luz , Fotossíntese/fisiologia , Folhas de Planta/metabolismo , Ribulose-Bifosfato Carboxilase/genética , Ribulose-Bifosfato Carboxilase/metabolismo
8.
Sci Rep ; 12(1): 8566, 2022 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35595814

RESUMO

In this work we suggest a novel paradigm of social laser (solaser), which can explain such Internet inspired social phenomena as echo chambers, reinforcement and growth of information cascades, enhancement of social actions under strong mass media operation. The solaser is based on a well-known in quantum physics laser model of coherent amplification of the optical field. Social networks are at the core of the solaser model; we define them by means of a network model possessing power-law degree distribution. In the solaser the network environment plays the same role as the gain medium has in a physical laser device. We consider social atoms as decision making agents (humans or even chat bots), which possess two (mental) states and occupy the nodes of a network. The solaser establishes communication between the agents as absorption and spontaneous or stimulated emission of socially actual information within echo chambers, which mimic an optical resonator of a convenient (physical) laser. We have demonstrated that social lasing represents the second order nonequilibrium phase transition, which evokes the release of coherent socially stimulated information field represented with the order parameter. The solaser implies the formation of macroscopic social polarization and results in a huge social impact, which is realized by viral information cascades occurring in the presence of population imbalance (social bias). We have shown that decision making agents follow an adiabatically time dependent mass media pump, which acts in the network community reproducing various reliable scenarios for information cascade evolution. We have also shown that in contrast to physical lasers, due to node degree peculiarities, the coupling strength of decision making agents with the network may be enhanced [Formula: see text] times. It leads to a large increase of speed, at which a viral message spreads through a social media. In this case, the mass media pump supports additional reinforcement and acceleration of cascade growth. We have revealed that the solaser model in some approximations possesses clear links with familiar Ising and SIS (susceptible-infected-susceptible) models typically used for evaluating a social impact and information growth, respectively. However, the solaser paradigm can serve as a new platform for modelling temporal social events, which originate from "microscopic" (quantum-like) processes occurring in the society. Our findings open new perspectives for interdisciplinary studies of distributed intelligence agents behavior associated with information exchange and social impact.


Assuntos
Lasers , Mídias Sociais , Comunicação , Humanos , Luz , Rede Social
9.
PLoS One ; 17(5): e0267989, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35511959

RESUMO

The addition of supplemental light (SL) is an effective way to offset insufficient lighting. Although it is commonly believed that SL increases leaf photosynthesis and therefore improves yield and fruit flavor, the mechanism underlying the effects of SL on the photosystem II (PSII) apparatus remains unclear, and SL leads to high energy consumption. In order to save energy, we investigated the physiological status of the PSII apparatus, plant growth parameters and fruit parameters under two types of overhead SL with a low daily energy consumption of 0.0918 kWh m-2. The results showed that SL significantly increased the leaf chlorophyll content from full unfolding to yellowing. However, a remarkable increase in the absorption flux per cross-section (ABS/CS), the quantum yield of electron transport (φEo) and the performance index (PIabs) was observed only in a relatively short period of the leaf life cycle. SL also enhanced the fruit yield and quality. The obviously increased ΔVK and ΔVJ components of the chlorophyll fluorescence induction kinetic (OJIP) curve, along with the significantly decreased PIabs from days 40-60 after unfolding in the SL-treated groups, resulted in more rapid leaf aging and earlier fruit ripening compared with the control plants (CK). Therefore, an energy-friendly SL strategy can alter the physiological status of the PSII apparatus, affecting yield and fruit quality and maturity.


Assuntos
Lycopersicon esculentum , Complexo de Proteína do Fotossistema II , Clorofila/farmacologia , Luz , Lycopersicon esculentum/metabolismo , Fotossíntese/fisiologia , Complexo de Proteína do Fotossistema II/metabolismo , Folhas de Planta/metabolismo
10.
Food Chem ; 389: 133086, 2022 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-35526285

RESUMO

Gallic acid (GA) is found in a wide range of natural plants and is relevant to the health of human beings. Here, a photoelectrochemical sensing platform based on g-C3N4@CNT heterojunction has been prepared for the highly sensitive and selective detection of GA. Under the light of xenon lamp, the photocurrent of g-C3N4@CNT is 7 times higher than that of g-C3N4. And the sensor generates 4 times more photocurrent in the presence of GA than without GA. This sensor has a wide linear range from 10 nM to 10 µM with a limit of detection as low as 2 nM. Also, the abundant amino groups of g-C3N4 provide excellent selectivity for the sensor. Furthermore, the sensor can be used for the analysis of GA in black tea samples, which provides a novel and rapid method for the detection of GA in food samples.


Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , Antioxidantes , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Ácido Gálico , Humanos , Luz
11.
Inorg Chem ; 61(20): 7878-7889, 2022 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-35533083

RESUMO

In this work, the effect of Keggin polyoxometalates encapsulated in Keplerate {Mo72Fe30} shell (K shell) on the visible light-assisted catalase-like activity (H2O2 dismutation) of the resulting core-shell clusters PMo12@K, SiMo12@K, and BW12@K was investigated. Superior photodismutation activity of PMo12@K compared to that of K shell and two other core-shell clusters was discovered. The homogeneity of PMo12@K and its improved oxidative stability, increased redox potential, and reduced band gap caused by a synergistic effect between the Keplerate shell and Keggin core seem reasonable to explain such a superiority. The light-dependent photocatalytic performance of PMo12@K evaluated by action spectra revealed a maximum apparent quantum efficiency (AQY) at 400 nm, demonstrating the visible light-driven photocatalytic reaction. A first-order rate constant of 2 × 10-4 s-1 and activation energy of 108.8 kJ mol-1 alongside a turnover frequency of 0.036 s-1 and a total turnover number of up to ∼3800 approved the effective photocatalytic activity and improved the oxidative stability of PMo12@K. A nonradical photocatalytic mechanism through a Fe-OOH intermediate was proposed. Thus, the structure, optical activity, and oxidative stability of a host Keplerate-type nanocluster can be tuned significantly by encapsulation of a guest, like "cluster-in-cluster" structures, which opens the scope for introducing new visible light-sensitive hierarchical nanostructures.


Assuntos
Peróxido de Hidrogênio , Nanoestruturas , Catalase , Catálise , Luz , Nanoestruturas/química
12.
Methods Mol Biol ; 2451: 245-258, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35505022

RESUMO

Metal-based compounds have been used to treat cancer for decades, with cisplatin being the most common and widely used. Photodynamic therapy (PDT) is another clinical modality used to fight cancer, which uses a photosensitizer (PS) that localizes in cancer tissues. This PS is activated by the illumination of the tumor with visible light. Photoactivated chemotherapy (PACT) is a new concept that brings these two ideas together. Like PDT , PACT aims at sparing healthy tissues while maintaining toxicity against cancerous cells. Unlike PDT , which often stops working when the concentration of dioxygen in illuminated tissues is too low, light activation of PACT compounds remains efficient in hypoxic cancer cells. This chapter addresses the methodology to experimentally measure the phototoxicity of PACT compounds in cancer cell lines, under both normoxic and hypoxic conditions.


Assuntos
Neoplasias , Fotoquimioterapia , Cisplatino , Humanos , Luz , Neoplasias/tratamento farmacológico , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico
13.
Methods Mol Biol ; 2451: 521-531, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35505029

RESUMO

Photodynamic therapy (PDT) has a great therapeutic potential because it induces local cellular cytotoxicity upon application of a laser light that excites a photosensitizer, leading to toxic reactive oxygen species. Nevertheless, PDT still is underutilized in the clinic, mostly because of damage induced to normal surrounding tissues. Efforts have been made to improve the specificity. Nanobody-targeted PDT is one of such approaches, in which the variable domain of heavy-chain antibodies, i.e., nanobodies, are used to target photosensitizers selectively to cancer cells. In vitro studies are certainly very valuable to evaluate the therapeutic potential of PDT approaches, but many aspects such as bio-distribution of the photosensitizers, penetration through tissues, and clearance are not taken into account. In vivo studies are therefore essential to assess the influence of such factors, in order to gain more insights into the therapeutic potential of a treatment under development. This chapter describes the development of an orthotopic model of head and neck cancer, to which nanobody-targeted PDT is applied, and the therapeutic potential is assessed by immunohistochemistry one day after PDT.


Assuntos
Neoplasias de Cabeça e Pescoço , Fotoquimioterapia , Anticorpos de Domínio Único , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Humanos , Luz , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Anticorpos de Domínio Único/farmacologia , Anticorpos de Domínio Único/uso terapêutico
14.
Methods Mol Biol ; 2451: 547-556, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35505031

RESUMO

Photodynamic therapy (PDT) is characterized by the local application of laser light, which activates a photosensitizer to lead to the formation of singlet oxygen and other toxic reactive oxygen species, to finally kill cells. Recently, photosensitizers have been conjugated to nanobodies to render PDT more selective to cancer cells. Nanobodies are the smallest naturally derived antibody fragments from heavy-chain antibodies that exist in animals of the Camelidae family. Indeed, we have shown that nanobody-targeted PDT can lead to extensive and selective tumor damage, and thus the subsequent step is to assess whether this damage can delay or even inhibit tumor growth in vivo. To evaluate the therapeutic efficacy of PDT, mouse models are mostly employed in which human tumors are grown subcutaneously in the flank of the animals. Although very useful, it has been suggested that these tumors are further away from their natural environment and that tumors developed in the organ or tissue of origin would be closer to the natural situation. Thus, this chapter describes the development of an orthotopic model of breast cancer and the application of nanobody-targeted PDT, for the assessment of the therapeutic efficacy.


Assuntos
Neoplasias da Mama , Fotoquimioterapia , Anticorpos de Domínio Único , Animais , Neoplasias da Mama/tratamento farmacológico , Feminino , Humanos , Luz , Camundongos , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Anticorpos de Domínio Único/farmacologia , Anticorpos de Domínio Único/uso terapêutico
15.
Nat Chem ; 14(5): 487-488, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35513567

Assuntos
Luz , Catálise
16.
J Agric Food Chem ; 70(18): 5541-5550, 2022 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-35475355

RESUMO

Photopharmacology provides superior temporal and spatial resolution for the study of biological functions of γ-aminobutyric acid receptors (GABARs), and photopharmacology based on GABARs has significantly advanced the research of neurons and cells. Herein, we reported the azobenzene-phenylpyrazole (ABPs) for controlling the function of GABARs by light. The insecticidal activity of ABPs against Aedes albopictus larvae was different before and after light illumination. ABP3 (1 µM) could induce depolarization of dorsal unpaired median neurons and enable the real-time photoregulation of mosquito larval behavior. An electrophysiological experiment indicated that ABP3 had different inhibitory effects on GABARs before and after illumination. ABPs realized optical control of GABARs utilizing visible light, providing valuable supplements to the existing GABAR photocontrol tools.


Assuntos
Inseticidas , Receptores de GABA , Animais , Compostos Azo/farmacologia , Inseticidas/farmacologia , Luz , Receptores de GABA/metabolismo , Receptores de GABA-A
17.
J Mater Chem B ; 10(18): 3550-3559, 2022 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-35420087

RESUMO

Herein, five aggregation-induced emission (AIE) photosensitizers (PSs) with D-π-A structures are smoothly designed and synthesized through donor and acceptor engineering. The photophysical properties and theoretical calculation results show that the synergistic effect of methoxy substituted tetraphenylethene (MTPE), 3,4-ethylenedioxythiophene can enhance the intramolecular charge transfer effect (ICT), and promote the intersystem crossing (ISC) process of the whole molecule. In these AIE-PSs, the best-performing AIE-PS (MTPE-DT-Py) has bright NIR (740 nm) emission, the highest 1O2 generation efficiency (5.9-fold that of Rose Bengal) and efficient mitochondrial targeting ability. Subsequently, PDT anti-cancer and anti-bacterial experiments indicate that MTPE-DT-Py could obviously target mitochondria and kill breast cancer cells (MCF-7), and selectively inactivate S. aureus (G(+)) under white light irradiation. This work mainly proposes a practical design strategy for high effect AIE-PSs and provides more excellent candidates for fluorescence imaging-guided photodynamic therapy.


Assuntos
Neoplasias , Fotoquimioterapia , Humanos , Luz , Neoplasias/tratamento farmacológico , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/química , Staphylococcus aureus
18.
Org Biomol Chem ; 20(18): 3767-3778, 2022 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-35438126

RESUMO

Nitrogen heterocycles, especially polycyclic compounds, are significant skeletons in valuable molecules. Herein, we developed an efficient and practical visible-light-induced acylation/cyclization of active alkenes with acyl oxime derivatives for constructing acylated indolo/benzimidazo-[2,1,a]isoquinolin-6(5H) ones. This reaction was compatible with various functional groups and a series of fused indole/imidazole skeletons were prepared in up to 95% yield at room temperature.


Assuntos
Alcenos , Compostos Policíclicos , Acilação , Ciclização , Luz
19.
Org Biomol Chem ; 20(17): 3558-3563, 2022 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-35416228

RESUMO

Quinazoline compounds demonstrate a variety of physiological and pharmacological activities. However, the most common syntheses require large quantities of oxidants, high temperature, and other extreme conditions. In this study, quinazoline compounds were synthesized from the condensation of α-keto acid and 2-aminobenzylamine and then decarboxylation under blue LED irradiation at room temperature without transition metal catalysts or additives. Therefore, we demonstrated that by using α-keto acid as the acyl source, decarboxylation can be realized under blue LED without oxidants, in a simple, mild, and environmentally friendly process.


Assuntos
Cetoácidos , Quinazolinas , Catálise , Descarboxilação , Luz , Oxidantes , Oxirredução
20.
Nat Chem ; 14(5): 574-581, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35361911

RESUMO

The formation of co-crystals by the assembly of molecules with complementary molecular recognition functionalities is a popular strategy to design or improve a range of solid-state properties, including those relevant for pharmaceuticals, photo- or thermoresponsive materials and organic electronics. Here, we report halogen-bonded co-crystals of a fluorinated azobenzene derivative with a volatile component-either dioxane or pyrazine-that can be cut, carved or engraved with low-power visible light. This cold photo-carving process is enabled by the co-crystallization of a light-absorbing azo dye with a volatile component, which gives rise to materials that can be selectively disassembled with micrometre precision using low-power, non-burning laser irradiation or a commercial confocal microscope. The ability to shape co-crystals in three dimensions using laser powers of 0.5-20 mW-substantially lower than those used for metals, ceramics or polymers-is rationalized by photo-carving that targets the disruption of weak supramolecular interactions, rather than the covalent bonds or ionic structures targeted by conventional laser beam or focused ion beam machining processes.


Assuntos
Halogênios , Luz , Cristalização , Eletrônica , Halogênios/química , Polímeros/química
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