Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 187
Filtrar
1.
J Environ Manage ; 357: 120760, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38581891

RESUMO

It is of great significance to solve the environmental problems caused by the unreasonable treatment of coal gasification slag. This study successfully produced Si-Fe-Al-Ca alloy from low-carbon fine slag with petroleum coke as reducing agent in a plasma furnace with an alternating current magnetic field, which solved the problem of the high reactivity requirement of carbon reductant for plasma smelting. The optimum carbon content of the mixed low-carbon fine slag and petroleum coke is 105% of the theoretical value. As the strength of the alternating current magnetic field increased (from 0% to 100% of the maximum power), the yield of the alloy (from 25.46% to 58.19%) and the recovery ratios of each element (Si, Fe, Al, Ca, Ti) increased. In addition, as the magnetic field strength increased, the pores inside the alloy became smaller, the composition of the alloy became more homogeneous, and a better separation of the alloy from the slag was observed. The main composition of the alloy at the strongest alternating current magnetic field is Si: 51.14 wt%, Fe: 28.41 wt%, Al: 9.14 wt%, Ca: 7.15 wt%, Ti: 2.03 wt%. We attribute the enhanced smelting effect of the alternating current magnetic field to the resistive heat and Lorentz force produced by the induced current. In addition, the skin effect concentrated the induced current on the surface of the oxide particles and carbon particles, which increased the temperature of the reaction interface and promoted the carbothermal reduction reaction.


Assuntos
Coque , Petróleo , Carvão Mineral , Ligas , Carbono
2.
Artigo em Inglês | MEDLINE | ID: mdl-38551483

RESUMO

Premature ventricular complexes (PVCs) are spontaneous excitations occurring in the ventricles of the heart, which are associated with ventricular arrhythmias and sudden cardiac death. Under long QT conditions, PVCs can be mediated by repolarization gradient (RG) and early afterdepolarizations (EADs), yet the effects of heterogeneities or geometry of the RG or EAD regions on PVC genesis remain incompletely understood. In this study, we use computer simulation to systematically investigate the effects of the curvature of the RG border region on PVC genesis under long QT conditions. We show that PVCs can be either promoted or suppressed by negative or positive RG border curvature depending on the source and sink conditions. When the origin of oscillation is in the source region and the source is too strong, a positive RG border curvature can promote PVCs by causing the source area to oscillate. When the origin of oscillation is in the sink region, a negative RG border curvature can promote PVCs by causing the sink area to oscillate. Furthermore, EAD-mediated PVCs are also promoted by negative border curvature. We also investigate the effects of wavefront curvature and show that PVCs are promoted by convex but suppressed by concave wavefronts, however, the effect of wavefront curvature is much smaller than that of RG border curvature. In conclusion, besides the increase of RG and occurrence of EADs caused by QT prolongation, the geometry of the RG border plays important roles in PVC genesis, which can greatly increase the risk of arrhythmias in cardiac diseases.

3.
Heliyon ; 10(6): e26967, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38500977

RESUMO

DNA synthesis and assembly primarily revolve around the innovation and refinement of tools that facilitate the creation of specific genes and the manipulation of entire genomes. This multifaceted process encompasses two fundamental steps: the synthesis of lengthy oligonucleotides and the seamless assembly of numerous DNA fragments. With the advent of automated pipetting workstations and integrated experimental equipment, a substantial portion of repetitive tasks in the field of synthetic biology can now be efficiently accomplished through integrated liquid handling workstations. This not only reduces the need for manual labor but also enhances overall efficiency. This review explores the ongoing advancements in the oligonucleotide synthesis platform, automated DNA assembly techniques, and biofoundries. The development of accurate and high-throughput DNA synthesis and assembly technologies presents both challenges and opportunities.

4.
Opt Lett ; 49(5): 1341-1344, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38427008

RESUMO

We propose and demonstrate a tunable fractional-order photonic differentiator (DIFF) that can process input pulses with a sub-gigahertz bandwidth. Our scheme utilizes the self-induced optical modulation effect observed in a silicon-on-insulator micro-ring resonator. Gaussian-like pulses with varying pulse widths between 7.5 and 20 ns are employed for differentiation, achieving an energy efficiency over 45%, to the best of our knowledge, which surpasses all previously reported schemes for input pulses with a sub-gigahertz bandwidth. We simulate the temporal dynamics of pulses to gain insight into the physical mechanisms underlying the differentiated outputs and provide a method for differentiation order adjustment, which is experimentally realized using an all-optical pump-probe technique.

5.
Eur J Med Chem ; 268: 116214, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38367490

RESUMO

The clinical treatment of patients with cancer who are also diagnosed with coronavirus disease (COVID-19) has been a challenging issue since the outbreak of COVID-19. Therefore, it is crucial to understand the effects of commonly used drugs for treating COVID-19 in patients with cancer. Hence, this review aims to provide a reference for the clinical treatment of patients with cancer to minimize the losses caused by the COVID-19 pandemic. In this study, we also focused on the relationship between COVID-19, commonly used drugs for treating COVID-19, and cancer. We specifically investigated the effect of these drugs on tumor cell proliferation, migration, invasion, and apoptosis. The potential mechanisms of action of these drugs were discussed and evaluated. We found that most of these drugs showed inhibitory effects on tumors, and only in a few cases had cancer-promoting effects. Furthermore, inappropriate usage of these drugs may lead to irreversible kidney and heart damage. Finally, we have clarified the use of different drugs, which can provide useful guidance for the clinical treatment of cancer patients diagnosed with COVID-19.


Assuntos
COVID-19 , Neoplasias , Humanos , SARS-CoV-2 , Pandemias , Neoplasias/tratamento farmacológico
6.
J Org Chem ; 89(3): 1633-1647, 2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-38235569

RESUMO

A metal-free and atom-economic route for the synthesis of naphtho[1,2-b]furan-3-ones has been realized via p-TsOH·H2O-catalyzed intramolecular tandem double cyclization of γ-hydroxy acetylenic ketones with alkynes in formic acid. The benzene-linked furanonyl-ynes are the key intermediates obtained by the scission/recombination of C-O double bonds. Further, the structural modifications of the representative product were implemented by reduction, demethylation, substitution, and [5 + 2]-cycloaddition.

7.
Artigo em Inglês | MEDLINE | ID: mdl-38165798

RESUMO

Recent years have witnessed the emergence of various techniques proposed for text-based human face generation and manipulation. Such methods, targeting bridging the semantic gap between text and visual contents, provide users with a deft hand to turn ideas into visuals via text interface and enable more diversified multimedia applications. However, due to the flexibility of linguistic expressiveness, the mapping from sentences to desired facial images is clearly many-to-many, causing ambiguities during text-to-face generation. To alleviate these ambiguities, we introduce a local-to-global framework with two graph neural networks (one for geometry and the other for appearance) embedded to model the inter-dependency among facial parts. This is based upon our key observation that the geometry and appearance attributes among different facial components are not mutually independent, i.e., the combinations of part-level facial features are not arbitrary and thus do not conform to a uniform distribution. By learning from the dataset distribution and enabling recommendations given partial descriptions of human faces, these networks are highly suitable for our text-to-face task. Our method is capable of generating high-quality attribute-conditioned facial images from text. Extensive experiments have confirmed the superiority and usability of our method over the prior art.

8.
Opt Lett ; 48(21): 5735-5738, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37910746

RESUMO

We demonstrate the realization of an anti-parity-time (PT)-symmetric photonic lattice in a coherent three-level Λ-type 85Rb atomic system both experimentally and theoretically. Such an instantaneously reconfigurable anti-PT-symmetric photonic lattice is "written" by two one-dimensional coupling fields, which are arranged alternately along the x direction and can modulate the refractive index of the atomic vapor in a spatially periodical manner via controllable atomic coherence. By properly adjusting the relevant atomic parameters, the phase shift between two adjacent lattice channels occurs in the constructed non-Hermitian photonic system. Such a readily reconfigurable anti-PT-symmetric photonic lattice may open the door for demonstrating the discrete characteristics of the optical waves in periodic anti-PT-symmetric photonic systems.

9.
Langmuir ; 39(41): 14550-14561, 2023 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-37782748

RESUMO

The silver coating is widely used in electronic device manufacturing due to its excellent conductivity and soldering properties. Conventional preparation of local silver coating often uses the preplated silver, mask high-speed silver plating, and deplated silver processes. In this paper, the laser-induced electrodeposition technique is used to perform maskless laser-induced localized electrodeposition on a copper substrate preplated with a layer of silver. After the deplated silver process, ultrathin silver coatings with high dimensional accuracy, good corrosion resistance, and good bonding were obtained. The spatial distribution of the transient temperature field under laser irradiation is studied, the variation pattern of cathode substrate current under laser irradiation is tested, and finally, the spatial distribution of the pressure field under laser irradiation is simulated by Comsol. The effect of different laser scanning methods on the coating morphology was investigated, and the experimental study of the different single pulse energy-induced localized silver coatings was systematically carried out. The results show that the localized coating obtained by cross-line scanning with a laser single pulse energy of 93 µJ is flat with a film thickness of 0.23 µm, high dimensional accuracy, and good bonding force and corrosion resistance properties. This method provides a new approach for the preparation of a localized silver coating.

10.
ACS Appl Mater Interfaces ; 15(41): 48495-48505, 2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37787656

RESUMO

Targeted silencing of resistance-associated genes by specific double-stranded RNA (dsRNA) is an attractive strategy for overcoming insecticide resistance in insect pests. However, silencing target genes of insect pests by feeding on dsRNA transported via plants remains challenging. Herein, a codelivery system of insecticide and dsRNA is designed by encapsulating imidacloprid and dsNlCYP6ER1 within zeolitic imidazolate framework-8 (ZIF-8) nanoparticles to improve the susceptibility of Nilaparvata lugens (Stål) to imidacloprid. With an average particle size of 195 nm and a positive surface charge, the derived imidacloprid/dsNlCYP6ER1@ZIF-8 demonstrates good monodispersity. Survival curve results showed that the survival rates of N. lugens treated with imidacloprid and imidacloprid@ZIF-8 were 82 and 62%, respectively, whereas, in the imidacloprid/dsNlCYP6ER1@ZIF-8 treatment group, the survival rate of N. lugens is only 8%. Pot experiments demonstrate that the survival rate in the imidacloprid/dsNlCYP6ER1@ZIF-8 treatment group was much lower than that in the imidacloprid treatment group, decreasing from 54 to 24%. The identification of NlCYP6ER1 expression and the fluorescence tracking of ZIF-8 demonstrate that ZIF-8 can codeliver dsRNA and insecticide to insects via rice. Safety evaluation results showed that the dsNlCYP6ER1@ZIF-8 nanoparticle had desirable biocompatibility and biosafety to silkworm. This dsRNA and insecticide codelivery system may be extended to additional insecticides with potential resistance problems in the future, greatly enhancing the development of pest resistance management.


Assuntos
Hemípteros , Inseticidas , Estruturas Metalorgânicas , Animais , Inseticidas/farmacologia , Estruturas Metalorgânicas/farmacologia , Resistência a Inseticidas/genética , RNA de Cadeia Dupla/genética , Neonicotinoides/farmacologia , Nitrocompostos/farmacologia , Insetos
11.
JACC Clin Electrophysiol ; 9(12): 2459-2474, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37831035

RESUMO

BACKGROUND: In Brugada syndrome (BrS), phase 2 re-excitation/re-entry (P2R) induced by the transient outward potassium current (Ito) is a proposed arrhythmia mechanism; yet, the most common genetic defects are loss-of-function sodium channel mutations. OBJECTIVES: The authors used computer simulations to investigate how sodium channel dysfunction affects P2R-mediated arrhythmogenesis in the presence and absence of Ito. METHODS: Computer simulations were carried out in 1-dimensional cables and 2-dimensional tissue using guinea pig and human ventricular action potential models. RESULTS: In the presence of Ito sufficient to generate robust P2R, reducing sodium current (INa) peak amplitude alone only slightly potentiated P2R. When INa inactivation kinetics were also altered to simulate reported effects of BrS mutations and sodium channel blockers, however, P2R occurred even in the absence of Ito. These effects could be potentiated by delaying L-type calcium channel activation or increasing ATP-sensitive potassium current, consistent with experimental and clinical findings. INa-mediated P2R also accounted for sex-related, day and night-related, and fever-related differences in arrhythmia risk in BrS patients. CONCLUSIONS: Altered INa kinetics synergize powerfully with reduced INa amplitude to promote P2R-induced arrhythmias in BrS in the absence of Ito, establishing a robust mechanistic link between altered INa kinetics and the P2R-mediated arrhythmia mechanism.


Assuntos
Síndrome de Brugada , Humanos , Animais , Cobaias , Síndrome de Brugada/genética , Arritmias Cardíacas/genética , Potenciais de Ação , Canais de Sódio/genética , Canais de Sódio/farmacologia , Potássio/farmacologia
12.
J Chem Phys ; 159(11)2023 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-37712795

RESUMO

Micro-nano symbiotic superamphiphobic surfaces can prevent liquids from adhering to metal surfaces and, as a result, improve their corrosion resistance, self-cleaning performance, pollution resistance, and ice resistance. However, the fabrication of stable and controllable micro-nano symbiotic superamphiphobic structures on metal surfaces commonly used in industry remains a significant challenge. In this study, a laser-electrochemical hybrid subtractive-additive manufacturing method was proposed and developed for preparing copper superamphiphobic surfaces. Both experimental and fluid simulation studies were carried out. Utilizing this novel hybrid method, the controllable preparation of superamphiphobic micro-nano symbiotic structures was realized. The experimental results showed that the prepared surfaces had excellent superamphiphobic properties following subsequent modification with low surface energy substances. The contact angles of water droplets and oil droplets on the surface following electrodeposition treatment reached values of 161 ± 4° and 151 ± 4°, respectively, which showed that the prepared surface possessed perfect superamphiphobicity. Both the fabrication method and the test results provided useful insights for the preparation of stable and controllable superamphiphobic structures on metal surfaces in the future.

13.
Pest Manag Sci ; 79(12): 5237-5249, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37595063

RESUMO

BACKGROUND: Weeds grow aggressively in agricultural fields, leading to reduced crop yields and an inability to meet the growing demand for food. Herbicides are currently the most effective method for weed control. However, the overuse of herbicides has resulted in the evolution of resistance mutants and has caused environmental pollution. Therefore, new technologies are urgently required to address this global challenge. RESULTS: We report a copper-benzene-1,4-dicarboxylate metal organic framework (Cu-BDC MOF)-functionalized carboxyl hollow mesoporous silica (HMS-COOH) delivery system for the pH-controlled release of the acetyl-CoA carboxylase (ACCase)-inhibiting herbicide quizalofop-p-ethyl (QE). The delivery system (QE@HMS@Cu-BDC) enabled the efficient control of barnyard grasses that are susceptible and resistant to ACCase-inhibiting herbicides, which showed 93.33% and 88.33% FW control efficacy at 67.5 g ha-1 , respectively. With the lowest pH value (3), QE and copper ion were released slowly to total 70.30% and 78.55% levels (respectively) from QE@HMS@Cu-BDC after 89 h. QE@HMS@Cu-BDC showed better absorption, conduction, transportation and ACCase activity inhibition performance than that of QE emulsifiable concentrate (EC) in both susceptible and ACCase-herbicide resistant barnyard grasses. In addition, with the safener effect of carrier HMS@Cu-BDC and the aid of the safener fenchlorazole-ethyl (FE), the application of QE@HMS@Cu-BDC was shown to mitigate the damage caused by QE to rice plants. CONCLUSION: This work found that the new material HMS-COOH@Cu-BDC can be used to mitigate herbicide-induced oxidative stress and improve rice plant safety. Futhermore, the QE@HMS-COOH@Cu-BDC constructed in this research might be used as an efficient nanopesticide formulation for weed controls in paddy rice fields. © 2023 Society of Chemical Industry.


Assuntos
Herbicidas , Oryza , Herbicidas/farmacologia , Acetil-CoA Carboxilase/genética , Cobre/farmacologia , Dióxido de Silício/farmacologia , Plantas Daninhas , Concentração de Íons de Hidrogênio , Resistência a Herbicidas
14.
ACS Appl Mater Interfaces ; 15(35): 41351-41361, 2023 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-37584154

RESUMO

The brown planthopper, Nilaparvata lugens (Stål), is a major rice pest in various Asian countries, causing significant negative impacts on rice yield and quality. In this study, we developed a novel nanoplatform (NIT@MON@CuS) for pesticide delivery that responds to redox and near-infrared light stimuli. The nanoplatform consisted of CuS nanoparticles with mesoporous organic silica (MON), loaded with nitenpyram (NIT). With an average size of 190 nm and a loading efficiency of 22%, NIT@MON@CuS exhibited remarkable thermal response in the near-infrared region, demonstrating excellent photothermal conversion ability and stability. In vitro release kinetics demonstrated the rapid release of nitenpyram under near-infrared light and glutathione conditions, facilitating a satisfactory temperature increase and accelerated drug release. The NIT@MON@CuS-treated group exhibited a higher mortality of N. lugens, increasing from 62 to 88% compared to the group treated with nitenpyram technical after 96 h. Bioassay revealed that NIT@MON@CuS significantly enhanced nitenpyram toxicity by more than 1.4-fold against both laboratory insecticide-resistant and field strains of N. lugens. Furthermore, RT-qPCR results demonstrated that MON@CuS had the capability to reduce P450 gene expression, thereby improving the sensitivity of N. lugens to insecticides. These findings suggest that MON@CuS holds great potential as an intelligent pest control platform, offering a sustainable and efficient approach to protect crops against pests.


Assuntos
Hemípteros , Inseticidas , Oryza , Praguicidas , Animais , Controle de Pragas , Oxirredução
15.
Gynecol Oncol ; 176: 43-52, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37442025

RESUMO

OBJECTIVE: This study aimed to determine the prognostic significance of positive peritoneal cytology (PC) on endometrial carcinoma (EC) patients under the ESGO/ESTRO/ESP risk classification. METHODS: This study retrospectively analyzed EC patients from 27 medical centers in China from 2000 to 2019. Patients were divided into three ESGO risk groups: low-risk, intermediate-risk and high-intermediate risk, and high-risk groups. The covariates were balanced by using the propensity score-based inverse probability of treatment weighting (PS-IPTW). The prognostic significance of PC was assessed by Kaplan-Meier curves and multivariate Cox regression analysis. RESULTS: A total of 6313 EC patients with PC results were included and positive PC was reported in 384 women (6.1%). The multivariate Cox analysis in all patients showed the positive PC was significantly associated with decreased PFS (hazard ratio [HR] 2.20, 95% confidence interval [CI] 1.55-3.13, P < 0.001) and OS (HR 2.25, 95% CI 1.49-3.40, P < 0.001),and the Kaplan-Meier curves also showed a poor survival in the intermediate and high-intermediate risk group (5-year PFS: 75.5% vs. 93.0%, P < 0.001; 5-year OS: 78.3% vs. 96.4%, P < 0.001); While in the low-risk group, there were no significant differences in PFS and OS between different PC status (5-year PFS: 93.1% vs. 97.3%, P = 0.124; 5-year OS: 98.6% vs. 98.2%, P = 0.823); in the high-risk group, significant difference was only found in PFS (5-year PFS: 62.5% vs. 77.9%, P = 0.033). CONCLUSION: Positive PC was an adverse prognostic factor for EC, especially in the intermediate and high-intermediate risk patients. Gynecologic oncologists should reconsider the effect of positive PC on different ESGO risk groups.


Assuntos
Citologia , Neoplasias do Endométrio , Feminino , Humanos , Prognóstico , Estudos Retrospectivos , Neoplasias do Endométrio/patologia , Peritônio/patologia
16.
Langmuir ; 39(29): 10079-10087, 2023 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-37429037

RESUMO

Ni-Co-W is an alloy with excellent overall performance and wide application prospects. Electrochemical deposition of Ni-Co-W alloys is currently the most promising process for replacing hexavalent chromium plating. Variations in the W content of the Ni-Co-W coating significantly affect its surface morphology, internal structure, and mechanical properties. Considering the numerous defects with conventional electrochemical deposition, a laser was introduced to enhance the quality and rate of deposition. Using a multienergy composite field, the deposition technique enhanced various properties at room temperature. Ni-Co-W alloy coatings were fabricated through electrochemical deposition and laser electrochemical deposition using electrolytes containing Na2WO4·2H2O at concentrations of 12, 15, 18, and 24 g/L in this investigation. This study aimed to examine how laser irradiation strengthens the corrosion resistance of the coatings. The corrosion resistance could be enhanced with an initial W content increase, but the corrosion resistance did not depend entirely on the W content. Variations in the W content of the electrochemically deposited coatings affected the surface morphology, residual internal stresses, and crystal structure, changing the corrosion resistance. In contrast, the laser electrochemical deposition coating was caused by the combined effect of the W content and laser irradiation (concentration of <18 g/L). Laser electrochemical deposition of the Ni-Co-W coating resulted in a higher W content than electrochemical deposition (≥3.5%), improved the residual internal stresses, and refined the grain size of the coating, resulting in better corrosion resistance (corrosion rate decreased by 74% and Rct increased by 109.1% at most).

17.
Waste Manag ; 169: 82-90, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37418787

RESUMO

The diamond wire saw silicon powder (DWSSP) is considered to be a harmful to the environment because of finer particles, the large specific surface area and flammability. Removal of Fe impurity is very essential for recovering Si from DWSSP due to the large amount of Fe introduced during the silicon powder generation process. In the study, the thermodynamics of Fe leaching with HCl was analyzed and determined iron was theoretically present as ions in solution. Furthermore, the effects of different concentrations, temperatures and liquid-solid ratios on Fe leaching from HCl were investigated. The leaching rate of Fe reached 98.37% at the optimal parameters (HCl concentration of 12 wt%, leaching temperature of 333 K, liquid-solid ratio of 15 ml/g) with 100 min. The leaching kinetics of Fe in HCl was analyzed by shrinking core model and homogeneous model, respectively. The study indicated the process of leaching Fe from DWSSP conforms to the secondary reaction model of homogeneous model which coincided with the porous structure of DWSSP due to agglomeration. The apparent activation energy required (49.398 kJ/mol) in the first stage is lower than that (57.817 kJ/mol) in the second stage because of the porous structure. In conclusion, this paper provided a suitable way to purify the diamond wire saw silicon powder. This work provides an important guide for the industrial recovery and preparation of high purity silicon from DWSSP by the most environment-friendly and low-cost approach.


Assuntos
Ferro , Silício , Pós , Cinética , Diamante
18.
Phys Rev Lett ; 131(1): 013802, 2023 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-37478430

RESUMO

Non-Hermitian systems with complex-valued energy spectra provide an extraordinary platform for manipulating unconventional dynamics of light. Here, we demonstrate the localization of light in an instantaneously reconfigurable non-Hermitian honeycomb photonic lattice that is established in a coherently prepared atomic system. One set of the sublattices is optically modulated to introduce the absorptive difference between neighboring lattice sites, where the Dirac points in reciprocal space are extended into dispersionless local flat bands, with two shared eigenstates: low-loss (high-loss) one with fields confined at sublattice B (A). When these local flat bands are broad enough due to larger loss difference, the incident beam with its tangential wave vector being at the K point in reciprocal space is effectively localized at sublattice B with weaker absorption, namely, the commonly seen power exchange between adjacent channels in photonic lattices is effectively prohibited. The current work unlocks a new capability from non-Hermitian two-dimensional photonic lattices and provides an alternative route for engineering tunable local flat bands in photonic structures.

19.
ChemSusChem ; 16(18): e202300582, 2023 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-37278140

RESUMO

Photoswitches can absorb solar photons and store them as chemical energy by photoisomerization, which is regarded as a promising strategy for photochemical solar energy storage. Although many efforts have been devoted to photoswitch discovery, the solar efficiency, a critical fundamental parameter assessing the solar energy conversion ability, has attracted little attention and remains to be studied comprehensively. Here we provide a systematic evaluation of the solar efficiency of typical azo-switches including azobenzenes and azopyrazoles, and gain a comprehensive understanding on its decisive factors. All the efficiencies are found below 1.0 %, far from the proposed limits for molecular solar thermal energy storage systems. Azopyrazoles exhibit remarkably higher solar efficiencies (0.59-0.94 %) than azobenzenes (0.11-0.43 %), benefiting from largely improved quantum yield and photoisomerization yield. Light filters can be used to improve the isomerization yield but inevitably narrow the usable range of solar spectrum, and these two contradictory effects ultimately reduce solar efficiencies. We envision this conflict could be resolved through developing azo-switches that afford high isomerization yields by absorbing wide-spectrum solar energy. We hope this work could promote more efforts to improve the solar efficiency of photoswitches, which is highly relevant to the prospect for future applications.

20.
Food Chem ; 427: 136721, 2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-37390742

RESUMO

Lateral flow immunoassay strips (LFIAs) are a reliable and point-of-care detection method for rapid monitoring of bacteria, but their sensitivity was limited by the low extinction coefficient of colloidal gold nanoparticles (Au NPs) and low capture efficiency of test-line. In this study, polydopamine nanoparticles (PDA NPs) were employed to replace Au NPs, due to their high extinction coefficient. And the amount of test-line was increased to 5 for further improving the efficiency of bacteria capture. Thus, under visual observation, the detection limits of PDA-based LFIAs (102 CFU/mL) were about 2 orders of magnitude lower than Au-based LFIAs (104 CFU/mL). Furthermore, the invisible signal could be collected by Image J and the detection limit can reach 10 CFU/mL. The proposed test strips were successfully applied for the quantitative, accurate, and rapid screening of E. coli in food samples. This study provided a universal approach to enhance the sensitivity of bacteria LFIAs.


Assuntos
Escherichia coli , Nanopartículas Metálicas , Limite de Detecção , Ouro , Imunoensaio
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...