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This study focused on constructing iron(III)-tetraamidomacrocyclic ligand (FeIII-TAML)-based magnetic nanostructures via a surfactant-assisted self-assembly (SAS) method to enhance the reactivity and recoverability of FeIII-TAML activators, which have been widely employed to degrade various organic contaminants. We have fabricated FeIII-TAML-based magnetic nanomaterials (FeIII-TAML/CTAB@Fe3O4, CTAB refers to cetyltrimethylammonium bromide) by adding a mixed solution of FeIII-TAML and NH3·H2O into another mixture containing CTAB, FeCl2 and FeCl3 solutions. The as-prepared FeIII-TAML/CTAB@Fe3O4 nanocomposite showed relative reactivity compared with free FeIII-TAML as indicated by decomposition of bisphenol A (BPA). Moreover, our results demonstrated that the FeIII-TAML/CTAB@Fe3O4 composite can be separated directly from reaction solutions by magnet adsorption and reused for at least four times. Therefore, the efficiency and recyclability of self-assembled FeIII-TAML/CTAB@Fe3O4 nanostructures will enable the application of FeIII-TAML-based materials with a lowered expense for environmental implication.
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Compostos Benzidrílicos , Compostos Férricos , Nanoestruturas , Fenóis , Compostos Férricos/química , Cetrimônio , Fenômenos MagnéticosRESUMO
Biocompatible polymers with nontraditional intrinsic luminescence (NTIL) possess the advantages of environmental friendliness and facile structural regulation. To regulate the emission wavelength of polymers with NTIL, the alkane chain lengths of hyperbranched polysiloxane (HBPSi) are adjusted. Optical investigation shows that the emission wavelength of HBPSi is closely related to the alkane chain lengths; namely, short alkane chains will generate relatively long-wavelength emission. Electronic communication among functional groups is responsible for the emission. In a concentrated solution, HBPSi molecules aggregate together due to the strong hydrogen bond and amphiphilicity, and the functional groups in the aggregate are so close that their electron clouds are overlapped and generate spatial electronic delocalizations. HBPSi with shorter alkane chains will generate larger electronic delocalizations and emit longer-wavelength emissions. Moreover, these polymers show excellent applications in the fabrication of fluorescent films and chemical sensing. This work could provide a strategy for regulating the emission wavelengths of unconventional fluorescent polymers.
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Recent studies showed that land is the most important sink for microplastics (MPs); however, limited information is available on the photoaging processes of land surface MPs that are exposed to the air. Herein, this study developed two in situ spectroscopic methods to systematically explore the effect of air humidity on MP photoaging using a microscope of Fourier transform infrared spectroscopy and a laser Raman microscope, which were equipped with a humidity control system. Polyethylene microplastics, polystyrene microplastics, and poly(vinyl chloride) microplastics (PVC-MPs) were used as model MPs. Our results showed that relative humidity (RH) could significantly influence the MP surface oxygen-containing moieties generated from photo-oxidation, especially for PVC-MPs. As the RH level varied from 10 to 90%, a decrease in the photogenerated carbonyl group and an increase in the hydroxyl group were observed. This could be attributed to the involvement of water molecules in the production of hydroxyl groups, which subsequently inhibited carbonyl generation. Moreover, the adsorption of coexisting contaminants (i.e., tetracycline) on photoaged MPs exhibited strong RH dependence, which could be assigned to the varied hydrogen bonding between tetracycline carbonyls and aged MP surface hydroxyls. This study reveals a ubiquitous but previously overlooked MP aging route, which may account for the changed MP surface physiochemical properties under solar irradiation.
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Envelhecimento da Pele , Poluentes Químicos da Água , Umidade , Microplásticos , Plásticos , Polietileno , TetraciclinasRESUMO
The photon sieve has had the problem of low diffraction efficiency since it was proposed. Dispersion from different waveguide modes in the pinholes also reduces the quality of focusing. To overcome the above drawbacks, we propose a kind of photon sieve working in the terahertz band. In a metal square-hole waveguide, the effective index is determined by the side length of the pinhole. We adjust the optical path difference by changing the effective indices of those pinholes. When the thickness of the photon sieve is fixed, the optical path in a zone is set to be a multilevel distribution from 0 to λ. In this way, the optical path differences caused by the waveguide effect of pinholes are used to compensate for those caused by the positions of pinholes. We also derive the focusing contribution of an individual square pinhole. The simulated example shows a 60 times increase in intensity than that of the equal-side-length single-mode waveguide photon sieve.
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BACKGROUND: Medical device-related pressure injuries(MDRPI) are prevalent and attracting more attention. During ambulance transfer, the shear force caused by braking and acceleration; extensive medical equipment crowed in a narrow space add external risk factors for MDRPIs. However, there is insufficient research on the relationship between MDRPIs and ambulance transfers. This study aims to clarify the prevalence and characteristics of MDRPI during ambulance transfer. METHOD: A descriptive observational study was conducted with convenience sampling. Before starting the study, six PI specialist nurses certified by the Chinese Nursing Association trained emergency department nurses for three MDRPI and Braden Scale sessions, one hour for each session. Data and images of PIs and MDRPIs are uploaded via the OA system by emergency department nurses and reviewed by these six specialist nurses. The information collection begins on 1 July 2022 and ends on 1 August 2022. Demographic and clinical characteristics and a list of medical devices were collected by emergency nurses using a screening form developed by researchers. RESULTS: One hundred one referrals were eventually included. The mean age of participants was (58.3 ± 11.69) years, predominantly male (67.32%, n = 68), with a mean BMI of 22.48 ± 2.2. The mean referral time among participants was 2.26 ± 0.26 h, the mean BRADEN score was 15.32 ± 2.06, 53.46% (n = 54) of participants were conscious, 73.26% (n = 74) were in the supine position, 23.76% (n = 24) were in the semi-recumbent position, and only 3 (2.9%) were in the lateral position. Eight participants presented with MDRPIs, and all MDRPIs are stage 1. Patients with spinal injuries are most prone to MDRPIs (n = 6). The jaw is the area most prone to MDRPIs, caused by the cervical collar (40%, n = 4), followed by the heel (30%, n = 3) and nose bridge (20%, n = 2) caused by the respiratory devices and spinal board. CONCLUSION: MDRPIs are more prevalent during long ambulance referrals than in some inpatient settings. The characteristics and related high-risk devices are also different. The prevention of MDRPIs during ambulance referrals deserves more research.
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Ambulâncias , Úlcera por Pressão , Humanos , Masculino , Pessoa de Meia-Idade , Idoso , Feminino , Úlcera por Pressão/epidemiologia , Úlcera por Pressão/etiologia , Úlcera por Pressão/prevenção & controle , Pacientes Internados , Prevalência , Encaminhamento e ConsultaRESUMO
Unconventional fluorescent polymers possess the advantages of excellent biocompatibility, environmental friendliness, and facile structural regulation; however, such polymers usually have low fluorescence intensity and quantum yields in the long-wavelength range. In this work, three kinds of high-efficiency long-wavelength emissive hyperbranched polysiloxanes are obtained by introducing aromatic amino acids. These functionalized hyperbranched polysiloxanes have high fluorescence intensity and quantum yields in green, yellow, and red emission regions. Experimental results and density functional theory calculations reveal that the long-wavelength emission comes from the enhanced electronic communication among the conjugated π bonds, electron-rich atoms, and -Si(O)3 and other functional groups. Especially, the conjugated π bonds efficiently enlarge the spatial electronic delocalizations, resulting in the high-efficiency long-wavelength emission. Moreover, the prepared polymers show excellent applications in information encryption and film preparation. This work could serve as a guide to develop high-efficiency long-wavelength unconventional fluorescent polymers.
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Corantes Fluorescentes , Siloxanas , Fluorescência , Corantes Fluorescentes/química , Polímeros/química , LuzRESUMO
Unconventional fluorescent polymers have attracted increasing attention due to their facile synthesis, excellent biocompatibility, and novel photophysical properties. In this work, a truly multicolor emissive hyperbranched polysiloxane (HBPSi-ß-CD) is obtained through adjusting the distribution of electron-rich atoms and grafting ß-cyclodextrin; the quantum yields of HBPSi-ß-CD after being excited by 360, 420, 450, and 550 nm are 19.36, 31.46, 46.14 and 44.84%, respectively. The density functional theory calculations reveal that the truly multicolor emission is derived from the formed electron delocalization among the hydroxyl, amine, ether, and -Si(O)3 groups due to the strong intermolecular interaction, high density of electron-rich atoms, and low steric hindrance among functional groups. The prepared polymers could serve as a multisensitivity sensor in detecting Fe3+, Cu2+, and Co2+. The HBPSi-ß-CD shows low cytotoxicity and excellent cellular imaging capability. The self-assembly of HBPSi-ß-CD also possesses high drug loading capacity and pH-controlled drug release, especially, the drug delivery system could be applied in the visualization of controlled drug delivery.
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Polímeros , Siloxanas , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Preparações FarmacêuticasRESUMO
Fabry disease (FD) is a genetic disorder caused by a-galactosidase A gene mutation. Ultrastructural analysis revealing zebra bodies are the typical morphological characteristics. However, certain tricyclic antidepressants and some other medications could induce renal phospholipidosis mimicking FD. We report a 33-year-old man has been taking carbamazepine intermittently for around 10 years whenever he experiences pain and paresthesia in his fingers. He experienced mild edema on both lower limbs half a year ago. Laboratory tests revealed a fluctuating urine protein between + and ++. Electron microscopy revealed laminated "zebra body" in podocytes, which is typical of FD. However, the patient had no family history and the sequencing of the a-galactosidase gene revealed no mutations. The a-galactosidase A enzyme activity was normal at 6.03 µmol/mL/h (normal 2.40-17.65 µmol/mL/h), and low expression of globotriaosylceramide (Gb3) was detected in the renal tissue of this patient. Therefore, the diagnosis of Fabry disease was excluded. Considering the patient's long-term treatment with carbamazepine (blood level 1.8 µg/ml), we speculated whether the pathological features could be associated with renal phospholipidosis caused by carbamazepine. The follow-up data showed that proteinuria was improved (fluctuated at + ~ -) after discontinuing carbamazepine for six months, which further seemed to support the above diagnosis. Therefore, we concluded that a possible case of carbamazepine-induced renal phospholipidosis, mimicking that observed in FD, has been associated with its nephrotoxicity.
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Doença de Fabry , Nefropatias , Carbamazepina/efeitos adversos , Doença de Fabry/complicações , Doença de Fabry/diagnóstico , Doença de Fabry/tratamento farmacológico , Humanos , Rim/patologia , Nefropatias/patologia , Masculino , Proteinúria/etiologia , alfa-Galactosidase/genéticaRESUMO
Fluorescent hyperbranched polysiloxane (HBPSi) has attracted increasing attention due to its good biocompatibility. However, its emission mechanism remains an open question. Unfortunately, the excitation spectra of HBPSi are rarely systematically investigated and show a narrow excitation band, which hinders the emission mechanism study. Herein, we synthesized a series of novel HBPSi containing l-glutamic acid (HBPSi-GA). Surprisingly, these polymers have four excitation peaks and two emission peaks, which are caused by the energy transfer from free functional groups to heterogeneous electron delocalizations in different clusters. Meanwhile, the fluorescence and biocompatibility of HBPSi-GA are significantly improved with increasing l-glutamic acid. Furthermore, HBPSi-GA exhibits dual stimuli-responsive fluorescence to temperature and Fe3+ as well as potential application in cell imaging. This research possesses important guidance to develop multiexcitation unconventional fluorescent polymers.
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Polímeros , Siloxanas , Transferência de Energia , FluorescênciaRESUMO
Hyperbranched polysiloxane (HBPSi) is attracting increasing attention due to its intrinsic fluorescence and good biocompatibility. However, it is very challenging to explore its biological applications because of the low fluorescence intensity and quantum yield. Herein, we introduced rigid ß-cyclodextrin to the end of flexible polysiloxane chain to synthesize a novel fluorescent polymer (HBPSi-CD) and explore its biological applications. Results showed that the fluorescence intensity and quantum yield of HBPSi-CD, compared with HBPSi, were significantly enhanced. Theoretical calculations and transmission electron microscopy demonstrated that the synergy effect of intra/intermolecular hydrogen bonds and hydrophobic effect promoted the formation of large supramolecular self-assemblies and space electron delocalization systems, leading to intense fluorescence. Notably, the biocompatible HBPSi-CD not only lighted up mouse fibroblast cells, but also possessed high ibuprofen loading capacity (160 mg g-1) and superior pH-responsive drug release performance. This work promoted the development of biological applications of HBPSi.
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Sistemas de Liberação de Medicamentos , Imagem Molecular/métodos , Siloxanas/química , beta-Ciclodextrinas/química , Animais , Materiais Biocompatíveis/química , Rastreamento de Células/métodos , Corantes Fluorescentes/química , Corantes Fluorescentes/farmacologia , Humanos , Ligação de Hidrogênio/efeitos dos fármacos , Camundongos , Siloxanas/farmacologia , beta-Ciclodextrinas/farmacologiaRESUMO
Graphene and Au nanorods (AuNRs) coated with SiO2@TiO2 double shells (AuNR@SiO2@TiO2) were incorporated to form novel composite photoanodes in dye sensitized solar cells (DSSCs). The performances of the photoanodes and DSSCs are studied systematically. The short circuit current density (J sc) and power conversion efficiency (PCE) of these composited DSSCs were greatly enhanced and the influences of the graphene, AuNRs and the SiO2@TiO2 double shells were revealed. The optimal properties with the maximal J sc of 16.26 mA cm-2 and PCE of 8.08% are obtained in the DSSC co-doped with graphene and AuNR@SiO2@TiO2, significantly higher than those of the conventional DSSC with pure TiO2 photoanode by 37.7% and 32.9%, respectively. These significant enhancements in J sc and PCE are attributed to the synergistic effect of graphene, the local surface plasma resonance of AuNRs, as well as the outer SiO2@TiO2 double shells, which result in the increased specific surface area and dye adsorption, the increased light absorption, the decreased charge transfer resistance R 2 and electron recombination and thus the increased J sc and PCE of the DSSCs.
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A novel kind of water-soluble fluorescent hyperbranched poly(amino ester) (PAE) is prepared through a one-pot polycondensation reaction of citric acid (CA) and N-methyldiethanolamine (NMDEA). The PAE exhibits enhanced and red-shift fluorescence with increasing solution concentration, showing distinct aggregation-induced emission character. Interestingly, the resulting PAE exhibits tunable photoluminescence from blue, cyan, and green to red irradiated by altering the excitation wavelengths. Such unique emission of non-conjugated PAE is attributed to the clustering of ester and tertiary amine groups derived from PAE self-assembly aggregates. Moreover, the fluorescence of PAE is very sensitive to Fe3+ ions. The facile preparation and unique optical features make PAE potentially useful in numerous applications such as multicolor cellular imaging, Fe3+ ions probe, and light-emitting diodes.
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Aminas/química , Ésteres/química , Fluorescência , Corantes Fluorescentes/química , Ferro/análise , Luminescência , Polímeros/química , Ferro/químicaRESUMO
TiO2 microspheres (TMSs) with unique hierarchical structure and unusual high specific surface area are synthesized and incorporated into a photoanode in various TMS multilayer gradient architectures to form novel photoanodes and dye-sensitized solar cells (DSSCs). Significant influences of these architectures on the photoelectric properties of DSSCs are obtained. The DSSC with the optimal TMS gradient-ascent architecture of M036 has the largest amounts of dye absorption, strongest light absorption, longest electron lifetime and lowest electron recombination, and thus exhibits the maximum short circuit current density (Jsc) of 16.49 mA cm-2 and photoelectric conversion efficiency (η) of 7.01%, notably higher than those of conventional DSSCs by 21% and 22%, respectively. These notable improvements in the properties of DSSCs can be attributed to the TMS gradient-ascent architecture of M036 which can most effectively increase dye absorption and localize incident light within the photoanode by the light scattering of TMSs, and thus utilize the incident light thoroughly. This study provides an optimized and universal configuration for the scattering microspheres incorporated in the hybrid photoanode, which can significantly improve the performance of DSSCs.
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The Au nanoparticle sandwich double spheric-shells of SiO2@Au@TiO2 (SAT) microspheres are synthesized. The significant influence of the SAT microspheres on the properties of dye-sensitized solar cells (DSSCs) is investigated. Studies indicate that the introduction of SAT markedly enhanced the light scattering and capture ability of DSSCs and thus photogenerated electrons. DSSCs doped with 2.25 wt% SAT exhibit a maximum short circuit current density of 17.0 mA cm-2 and photoelectric conversion efficiency of 7.14%, which are remarkably higher than those of conventional DSSCs at 15.7% and 21.2%, respectively. The marked enhancement in the performance of the optimal DSSCs can be attributed to the synergetic complementary effect of the enhanced light scattering of the microspheres and to the localized surface plasmon resonance of the Au nanoparticles in the SAT, and is a novel promising way of enhancing the performance of DSSCs.
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By solving the time-dependent Schrödinger equation both in simplified one-dimensional coordinate and three-dimensional cylindrical coordinate systems, the high-order harmonic generation from H2 + in spatially symmetric and asymmetric nonhomogeneous laser fields was studied. At large internuclear distances, minima were clearly observed in high energy part of harmonic spectra, which can be attributed to two-center interference in diatomic molecule. Compared with previous studies, the minima in nonhomogeneous laser field are more distinct. Remarkably, the positions of the minima are different in these two types of fields, which demonstrate that interference effects are greatly influenced by laser parameters. Besides, the asymmetric nonhomogeneous field leads to an asymmetric recollision of the ionized electron, and both odd and even order harmonics could be emitted, which is explained in detail based on quantum dynamics calculations.
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Graphene (G), TiO2 fusiform nanorods (TiO2NRs) adsorbed with Au nanoparticles (AuNPs) are prepared and blended as multifunctional materials into TiO2 nanocrystalline film to form a novel ternary (G-TiO2NRs-Au) composite photoanode in dye-sensitized solar cells (DSSCs). The effects of G-TiO2NRs-Au on the properties of the photoanode and DSSC are investigated. Results show that, by blending G-TiO2NRs-Au, the light absorption and scattering of the photoanode are obviously improved, and the charge transfer resistance R2 and electron recombination are decreased, resulting in a significant enhancement in the short-circuit current density (J sc) and the photoelectric conversion efficiency (PCE) of the DSSCs. The maximum J sc of 17.66 mA cm(-2) and PCE of 8.56% are obtained in the optimal G-TiO2NRs-Au-based DSSC, about 33.6% and 35.0% higher than that obtained in the conventional TiO2-based DSSC. This significant improvement in the performance of the DSSC can be attributed to the ternary composite complementary effects of multi-functions from the surface plasmon resonance of AuNPs, light scattering of TiO2NRs, and the improved dye loading and fast electron transmission channel from graphene. This study provides an effective way of ternary composite complementary enhancement of the J sc and PCE of the DSSCs.
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Emission of the two electrons released from nonsequential double ionization of argon atoms is anticorrelated at lower laser intensities but is correlated at higher laser intensities. Such a transition is caused by the momentum change of recollision-induced-ionization (RII) electrons. At lower laser intensities, the Coulomb repulsion between the two RII electrons dominates the motion of electrons and pushes them leaving the laser field back-to-back. At higher laser intensities, the drift momentum obtained from the laser field dominates the motion of electrons and drives them leaving the laser field side-by-side.
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We theoretically introduced a design paradigm and tool by extending the circuit functionalities from radio frequency to near infrared domain, and a broad band-stop filter, is successfully demonstrated by cascading triple layers of nano-square arrays. The feasibility is confirmed by its consistency with the rigorous FDTD calculation. Moreover, such a third-order Butterworth filter is not only insensitive to the incident angle and but also to input light's polarization. The new paradigm forms a theoretical foundation for designing optical devices and also enriches the classic circuit operations at the optical frequency region.
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We theoretically introduced a design paradigm and tool by extending the circuit functionalities from radio frequency to near infrared domain, and its first usage to design a broadband near-infrared (1.5µm~3.5µm) absorber, is successfully demonstrated. After extracting the equivalent circuit (EC) model of the absorber structure, the formerly relatively complicated frequency response can be evaluated relatively easily based on classic circuit formulas. The feasibility is confirmed by its consistency with the rigorous FDTD calculation. The absorber is an array of truncated metal-dielectric multilayer composited pyramid unit structure, and the gradually modified square patch design makes the absorber be not sensitive to the incident angle and polarization of light.
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We present a theoretical investigation of high-order harmonic generation in spatially inhomogeneous two-color laser fields by solving three dimensional time dependent Schrödinger equation. The cutoff in the harmonic spectra can be significantly extended by means of our proposed method (i.e., from helium interacting with the plasmon-enhanced two-color laser fields), and an ultrabroad supercontinuum up to 1.5 keV is generated by selecting proper carrier-envelope phase of the controlling field. Moreover, classical trajectory extraction, time-dependent ionization and recombination rates, and time-frequency analyses are used to explain the generation of this ultrabroadband supercontinuum. As a result, an isolated 8.8 attosecond pulse can be generated directly by the superposition of the supercontinuum harmonics.