Femtosecond Laser Combined with Hydrothermal Method to Construct Three-Dimensional Spatially Distributed Wurtzite ZnO Micro/Nanostructures to Enhance Photocatalytic Properties.

Conventional approaches employing nanopowder particles or deposition photocatalytic nanofilm materials encounter challenges such as performance instability, susceptibility to detachment, and recycling complications in practical photocatalytic scenarios. In this study, a novel fabrication strategy is proposed that uses femtosecond laser direct writing of self-sourced metal to prepare a self-supporting microstructure substrate and combines the hydrothermal method to construct a three-dimensional spatially distributed metal oxide micro/nanostructure. The obtained wurtzite ZnO micro/nanostructure has excellent wetting properties while obtaining a larger specific surface area and can achieve effective adsorption of methyl orange molecules. Moreover, the tight integration of ZnO with the surface interface of the self-sourced metal microstructure substrate will facilitate efficient charge transfer. Simultaneously, it improves the efficiency of light utilization (absorption) and the number of active sites in the photocatalytic process, ultimately leading to excellent photodegradation stability. This result provides an innovative technology solution for achieving efficient semiconductor surface-interface photocatalytic performance and stability.

Density Functional Theory and Raman Spectroscopy Studies of Adsorption Sites of Au Nanoparticles with Alectinib.

Alectinib is an ALK tyrosine kinase inhibitor, which is mainly used in patients with crizotinib-resistant nonsmall cell lung cancer. Alectinib has attracted much clinical attention for its longest progression-free survival time and the best therapeutic effect. The chemical adsorption of Au nanoclusters (AuNPs) with alectinib molecules is studied by density functional theory (DFT) and surface-enhanced Raman scattering spectroscopy (SERS) experiments. DFT/B3LYP-D3/6-311G** was used for optimization and vibration analysis of alectinib-Au6 complexes, as well as molecular electrostatic potential, frontier molecular orbital, and electro-optic-based charge transfer descriptors. Comparing the results of the DFT theory and SERS experiment, alectinib and AuNPs can form Au-N6 bonds primarily through chemical adsorption of N6 atoms, and the experimental results showed that the enhancement factor (EFCHEM) could reach 4.27. The results provide a theoretical basis for exploring the mechanism of chemical enhancement between AuNPs and alectinib.

Impact of the geometry of the excitation structure on optical skyrmion.

Optical skyrmions have attracted great attention for the potential applications in novel information storage and communication. It is of great significance to get insight into the generation of optical skyrmions by surface waves. Here, we have paid greater emphasis on the influence of the geometry of the coupling structure on the formation of optical skyrmions. Optical skyrmions are constructed from the superposition of the interfering surface plasmons excited by polygon trenches on Ag film. The results show the field texture of optical skyrmions is mainly determined by the excitation structure, with distinct properties revealed with various closed and non-closed geometries. Moreover, the ratio between the electric field strengths of the optical skyrmions can be larger than 4 between the optimized and unoptimized coupling structures. The pattern of the optical skyrmion shows a strong dependence on the excitation structure, implying the significant role in skyrmion topology it plays.

Effects of Au6 and Au20 Adsorption Sites of Cyromazine-Au Complexes by Raman Spectroscopy and Density Functional Theory.

Cyromazine, when used as an insect growth regulator and low-toxicity insecticide, may degrade into melamine and pose a potential threat to the environment and soil health, which has thus attracted extensive research on eliminating such a harmful effect. In this paper, density functional theory (DFT)/LC-BLYP/6-311G(d,p) is used to optimize the geometric structure and analyze the vibration of cyromazine. The DFT/LC-BLYP/def2-SVP is used for the cyromazine-Au complex optimization and vibration analysis. The molecular electrostatic potential (MEP), frontier molecular orbitals (FMOs), vibration frequency, electrophilicity-based charge transfer (ECT) descriptor, binding energy (BE), polarizability, normal Raman spectroscopy (NRS), and surface-enhanced Raman spectroscopy (SERS) of cyromazine adsorbing on Au6 and Au20 are calculated. The study of the chemical enhancement mechanism of SERS of cyromazine at different adsorption sites of Au6 or Au20 confirms the existence of a charge transfer between cyclopromazine and Au6 and Au20, which can adsorb and form stable cyromazine-Au complexes. The results show that N2, H13, and N4 are the adsorption sites of Au6 and Au20. The Raman spectra of the cyromazine-Au complex can be selectively enhanced with a factor up to 9.07. Compared with those of cyromazine-Au6, the Raman spectra of cyromazine-Au20 are enhanced more significantly.

Directional Drop Rebound on Adhesive-Gradient Micro-Nanostructured Surfaces Formed by a Femtosecond Laser.

The dynamic behavior of droplets hitting a solid surface has received extensive attention due to its broad application prospects. Additionally, controlling the rebound behavior of impacting droplets is an important research topic. Current methods for investigating this behavior focus on the construction of a differentiated wettability surface, which is characterized by contact angle measurements, or a differentiated topography surface, which is represented by geometric height. This information allows one to obtain the nonuniform kinetic energy distribution of rebounding droplets and to realize control of rebounding droplet behavior. In this paper, femtosecond laser processing is proposed for the fabrication of an anisotropic surface with differences in adhesion, which allows for the control of impacting droplet rebound behavior. The experimental results show that the micro-nanostructure of the surface affects its adhesion. By changing the micro-nanostructure of the solid surface, the difference in surface adhesion can be controlled, thereby realizing precise control of impacting droplet rebound behavior. This study demonstrates that the micro-nanostructured surface formed by a femtosecond laser can be used to control a droplet rebound direction and landing site, which is of great significance to the development of liquid transport, microfluidic devices, and other fields.

Coaction effect of radiative and non-radiative damping on the lifetime of localized surface plasmon modes in individual gold nanorods.

Revealing the coaction effect of radiative and non-radiative damping on the lifetime of the localized surface plasmon resonance (LSPR) mode is a prerequisite for the applications of LSPR. Here, we systematically investigated the coaction effect of radiative and non-radiative damping on the lifetime of the super-radiant and sub-radiant LSPR modes of gold nanorods using time-resolved photoemission electron microscopy (TR-PEEM). The results show that the lifetime of the LSPR mode depends on the length of the gold nanorod, and the different variation behavior of an LSPR mode lifetime exists between the super-radiative mode and the sub-radiative one with the increase of nanorod length (volume). Surprisingly, it is found that the lifetime of the super-radiant LSPR mode can be comparable to or even longer than that of the sub-radiant LSPR mode, instead of the usual claim that a sub-radiant LSPR mode has a longer life than the super-radiant mode. Those TR-PEEM experimental results are supported by finite-difference time-domain simulations and are well explained by the coaction effect with the calculation of the radiative and non-radiative damping rate with the increase of the nanorod volume. We believe that this study is beneficial to build a low-threshold nano-laser and ultrasensitive molecular spectroscopy system.

Combined laser-induced breakdown spectroscopy and hyperspectral imaging with machine learning for the classification and identification of rice geographical origin.

With the events of fake and inferior rice and food products occurring frequently, how to establish a rapid and high accuracy monitoring method for rice food identification becomes an urgent problem. In this work, we investigate using combined laser-induced breakdown spectroscopy (LIBS) and hyperspectral imaging (HSI) with machine learning algorithms to identify the place of origin of rice production. Six geographical origin rice samples grown in different parts of China are selected and pretreated, and measured by the atomic emission spectra of LIBS and the reflection spectra of HSI, respectively. The principal component analysis (PCA) is utilized to realize data dimensionality and extract the data feat of LIBS, HSI and fusion data, and based on this, three models employing the partial least squares discriminant analysis (PLS-DA), the support vector machine (SVM) and the extreme learning machine (ELM) are used to identify the rice geographical origin. The results show that the accuracy of LIBS and HSI analysis with the SVM machine learning algorithm can reach 93.06% and 88.07%, respectively, and the accuracy of combined LIBS and HSI data fusion recognition can reach 99.85%. Besides, the classification accuracy of the three models measured after pretreatment is basically all above 95%, and up to 99.85%. This study proves the effectiveness of using the combined LIBS and HSI with the machine learning algorithm in rice geographical origin identification, which can achieve rapid and accurate rice quality and identity detection.

Corrigendum: A prosperous application of hydrogels with extracellular vesicles release for traumatic brain injury.

[This corrects the article DOI: 10.3389/fneur.2022.908468.].

A Prosperous Application of Hydrogels With Extracellular Vesicles Release for Traumatic Brain Injury.

Traumatic brain injury (TBI) is one of the leading causes of disability worldwide, becoming a heavy burden to the family and society. However, the complexity of the brain and the existence of blood-brain barrier (BBB) do limit most therapeutics effects through simple intravascular injection. Hence, an effective therapy promoting neurological recovery is urgently required. Although limited spontaneous recovery of function post-TBI does occur, increasing evidence indicates that exosomes derived from stem cells promote these endogenous processes. The advantages of hydrogels for transporting drugs and stem cells to target injured sites have been discussed in multitudinous studies. Therefore, the combined employment of hydrogels and exosomes for TBI is worthy of further study. Herein, we review current research associated with the application of hydrogels and exosomes for TBI. We also discuss the possibilities and advantages of exosomes and hydrogels co-therapies after TBI.

The chemical adsorption effect of surface enhanced Raman spectroscopy of nitrobenzene and aniline using the density functional theory.

Nitrobenzene and Aniline are representatives of the nitro or amino compounds of benzene, mainly used in the manufacture of dyes, spices, medicines, and so on. Extensive use of Nitrobenzene and Aniline may cause pesticide residue pollution and have carcinogenic effects on organisms. In this paper, the Nitrobenzene and Aniline single molecules and their complexes with gold nanoparticles are studied theoretically by Raman spectroscopy, the surface-enhanced Raman spectroscopy (SERS) and the density functional theory (DFT) simulations. Selective binding of gold nanoparticles (AuNPs) to the analyte was used to study the molecular electrostatic potential (MEP), frontier molecular orbital (FMO) and the Raman activity spectra of Nitrobenzene and Aniline, as well as the Raman activity spectrum of the complexes. The most electronegative sites of Nitrobenzene and Aniline are found in the MEP and the hypothesis that these sites might be the adsorption sites of Nitrobenzene/Aniline molecules at the gold surface. At the same time, the MEP of the Nitrobenzene/Aniline complexes also prove the existence of the charge transfer effect between Nitrobenzene/Aniline and Au. The FMO energy gap of Nitrobenzene/Aniline is 0.18983 eV and 0.18953 eV, respectively, and which, after adding the Au3 clusters, change to 0.03376 eV and 0.0797 eV, respectively, indicating that the Nitrobenzene/Aniline-Au3 complexes have stronger chemical activities and are more prone to the charge transfer effects. The electrophilic indices of Nitrobenzene (0.17921 eV) and Aniline (0.05635 eV) are calculated and analyzed, as well as that of Nitrobenzene/Aniline-Au3 complexes after adding the Au3 atomic clusters, 0.80819 eV and 0.19819 eV, respectively. The obvious increasing trend in the electrophilic indices of the Nitrobenzene/Aniline-Au3 complexes indicate their stronger biological activities and more prone to chemical reactions. The chemisorption of Nitrobenzene/Aniline and gold nanoparticles complexes is studied by the SERS, and the Raman formation of the complexes at different binding sites of Nitrobenzene/Aniline and Nitrobenzene/Aniline-Au3 is well explained by the surface selection rule. The reason for the selective enhancement of the spectral peaks presented in the Raman activity spectrum is calculated, and the enhancement factor of the chemical enhancement due to the charge transfer effect is calculated as well. The reason for the peak offset in the SERS spectrum to the conventional Raman spectrum is explained.

The characteristics of Raman spectroscopy of isomer CBD- and THC-Au nanoparticles using the density functional theory.

The isomers cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC) can both be extracted from cannabis. We use density functional theory to study the Raman activity spectra, frontier molecular orbitals, and molecular electrostatic potentials of CBD, THC, and their respective gold complexes. A "selectivity enhancement" phenomenon for the spectral peaks at frequencies of 1144 cm-1 and 1553 cm-1 in the Raman spectrum of the CBD-Aun complex, and at frequencies of 865 cm-1, 1335 cm-1, and 1553 cm-1 in the Raman spectrum of the THC-Aun complex, was observed and explained. The frontier molecular orbital energy gaps of CBD and THC are 5.4085 eV and 5.4461 eV, respectively, indicating that CBD is more likely to react than THC. The CBD/THC-Au complexes had the strongest chemical activities and greater charge transfer effects with an Au3 cluster. The most electronegative sites of CBD and THC were found from molecular electrostatic potential (MEP) mapping. It is assumed that these sites are the adsorption sites of the CBD/THC molecules and gold surface. The MEP of the CBD/THC complexes also demonstrates the charge transfer effect between CBD/THC and Au. Both the "selectivity" phenomenon in the Raman activity spectra of the complex and the above assumption are explained by a surface selection rule. The conformation of the CBD/THC molecules on the gold surface are determined, showing that CBD is adsorbed vertically through the resorcinol structure while THC is adsorbed vertically through the tetrahydropyran and benzene ring.

Chemical Enhancement Effect of Icotinib-Au Complex Studied by Combined Density Functional Theory and Surface-Enhanced Raman Scattering.

Icotinib is an epidermal growth factor receptor tyrosine kinase inhibitor used in the treatment of non-small cell lung cancer. The charge transfer effect between gold nanoparticles (AuNPs) and icotinib molecules can be used as a model to study the adsorption mechanism between molecules and metal. The adsorption of icotinib on the AuNP surface was confirmed by UV-vis and transmission electron microscopy (TEM) experiments. To explain the nature of chemisorption between icotinib and AuNPs from a theoretical perspective, the molecular correlation properties of the complex model of icotinib-Au6 were studied by the density functional theory method. By studying the molecular electrostatic potential of an icotinib molecule, four potential binding sites of the icotinib molecule were predicted. The calculation results of binding energy showed that the complex formed by chemisorption of icotinib through acetylene group and Au6 was the most stable one. The molecular frontier orbitals of icotinib and icotinib-Au6 confirmed that the charge transfer effect occurred on the acetylene group, benzene ring, and quinazoline ring of the icotinib molecule. The Herzberg-Teller surface selection rule was used to explain selective enhancement in the theoretically calculated Raman spectra. By comparing the spectra of theory and experiment, the cause of spectral peak shift and broadening that appeared in the surface-enhanced Raman scattering spectrum compared with the normal Raman spectrum was explained as well. This work would contribute to the development and application of the icotinib-Au drug carrier system.

Ventriculosternal Shunt for the Treatment of Idiopathic Normal Pressure Hydrocephalus: A Case Report.

Background: Conventional corticospinal fluid (CSF) diversion surgery for idiopathic normal pressure hydrocephalus (iNPH) includes ventriculoperitoneal shunt and ventriculoatrial shunt. Ventriculosternal (VS) shunt may be considered if both the abdominal cavity and atrium are not feasible. Methods: A 76-year-old woman was admitted to our hospital with gait disturbance and urinary incontinence for 2 years, and the condition aggravated in the last 1 month. Based on clinical assessment and imaging findings, the patient was diagnosed with iNPH, with surgical indications. She was on peritoneal dialysis for chronic renal failure, and a cardiac Doppler echocardiogram showed enlargement of the left atrium and decreased diastolic function of the left ventricle. Due to these conditions, we chose the sternum as the vessel for CSF absorption and performed VS shunt. Results: No swelling, exudation, and effusion were found in the suprasternal fossa. Gait disturbance and urinary incontinence improved significantly immediately and 1 week after surgery, respectively. No shunt-related complication was reported at 16 months follow-up. Conclusion: This case demonstrated VS shunting as a feasible and alternative for the management of hydrocephalus.

A connectomic analysis of deep brain stimulation for treatment-resistant depression.

OBJECTIVE: Deep brain stimulation (DBS) has been used as a treatment of last resort for treatment-resistant depression (TRD) for more than a decade. Many DBS targets have been proposed and tested clinically, but the underlying circuit mechanisms remain unclear. Uncovering white matter tracts (WMT) activated by DBS targets may provide crucial information about the circuit substrates mediating DBS efficacy in ameliorating TRD. METHODS: We performed probabilistic tractography using diffusion magnetic resonance imaging datas from 100 healthy volunteers in Human Connectome Project datasets to analyze the structural connectivity patterns of stimulation targeting currently-used DBS target for TRD. We generated mean and binary fiber distribution maps and calculated the numbers of WMT streamlines in the dataset. RESULTS: Probabilistic tracking results revealed that activation of distinct DBS targets demonstrated modulation of overlapping but considerably distinct pathways. DBS targets were categorized into 4 groups: Cortical, Striatal, Thalamic, and Medial Forebrain Bundle according to their main modulated WMT and brain areas. Our data also revealed that Brodmann area 10 and amygdala are hub structures that are associated with all DBS targets. CONCLUSIONS: Our results together suggest that the distinct mechanism of DBS targets implies individualized target selection and formulation in the future of DBS treatment for TRD. The modulation of Brodmann area 10 and amygdala may be critical for the efficacy of DBS-mediated treatment of TRD.

Anisotropic Ice Adhesion of Micro-Nano-Structured Metal Surface by a Femtosecond Laser.

The icephobic materials induced using micro-nano-structured surfaces have aroused great attention for promising applications. Previously, the characterization of ice adhesion of icephobic materials by shear force is usually performed without direction discrimination along the surface whatever the surface is anisotropic or not. In this work, we studied the direction-dependent ice adhesion strength on groove-shaped micro-nano-structured aluminum alloy surfaces formed using a femtosecond laser. It is found that the ice adhesion strength on the surfaces exhibits anisotropy, which corresponds to a smaller ice adhesion strength in the direction parallel to the groove than that orthogonal to the groove. Furthermore, it is found that the ice adhesion strength decreases with the increase in groove width in the orthogonal direction, while it does not change much in the parallel direction. The anisotropic ice adhesion strength is attributed to the change of wettability and morphology in the two directions. The findings in this work suggest that anisotropic ice adhesion should be fully considered when designing an icephobic micro-nano-structured metal structure, which is of great significance to the characterization and application of icephobic materials.

Effects of frost formation on the ice adhesion of micro-nano structure metal surface by femtosecond laser.

In this work, we study the effect and evolution of frost condensation on the ice adhered micro-nano structured Ni metal surface. By measuring the ice adhesion strength to the porous-structured surface under different frosting coverage, it is found that the ice adhesion on the surface changes not only with the morphology but also with the different evolution stages of the frosting coverage. Combining the changes in surface morphology and low-temperature wettability, the reasons for the changes in the ice adhesion strength are attributed to the change of wettability of the porous-structured surface under different frosting coverage, which affects the infiltration state of the surface and results in different mechanical interlocking, air-pockets and cracks states at the ice-solid interface. Moreover, it is found that the ice adhesion strength of the hydrophobic and hydrophilic porous-structured surface tends to be the same when the surface is heavily frosted. In addition, we demonstrate that both the hydrophobic and hydrophilic columnar-structured surfaces have smaller ice adhesion strength than the original surface without any micro-nano structures regardless of whether the surface is frosted or not, and the measured lowest ice adhesion strength of the hydrophobic columnar-structured surface can be down to 30 kPa in all frosted evolution stages, which is less than one tenth of the original surface. The findings in this work suggest that the influence of frosting should be fully considered when designing the icephobic micro-nano structured metal structure, and it can further serve as an important guidance for the design of passive icephobic surfaces expected to be free from the frosting effect.

The characteristics of Raman spectroscopy of fenbendazole-gold nanoparticles based on the chemical adsorption effect.

Fenbendazole, a benzimidazole derivative with anti-tubulin polymerization properties, has been widely used in the treatment of parasitic infections. Because of its anticancer activity similar to that of many anticancer drugs, low cost and few side effects, fenbendazole has attracted wide research attention. The chemical adsorption of fenbendazole and gold nanoparticles are studied by the UV-Vis spectrophotometry, density functional method, Raman spectroscopy and surface-enhanced Raman spectroscopy. By comparing and analyzing the theoretical and experimental Raman spectra, this paper explains the reasons for the difference between the theoretical and experimental Raman spectra. Meanwhile, it is also found that the frequencies at 851 cm-1, 1222 cm-1, 1425 cm-1 and 1566 cm-1 are greatly enhanced. It is found that imidazole is adsorbed vertically to the surface of the substrate. It is concluded that Fenbendazole is vertically adsorbed on the surface of AuNPs through imidazole.

An evolving perspective of endoscopic transnasal optic canal decompression for traumatic optic neuropathy in clinic.

Traumatic optic neuropathy (TON) is a serious complication of craniofacial trauma, which damages the optic nerve indirectly and leads to dysfunction of visual acuity. The clinical intervention for a patient with TON includes optic canal decompression (with or without steroids), treatment with corticosteroids alone, or observation only. Currently, there is a controversy among clinicians as to which treatment is optimal. An increasing number of retrospective studies have unveiled that patients could experience significant improvement in visual acuity after optic canal decompression surgery, particularly endoscopic transnasal/transethmosphenoid optic canal decompression (ETOCD), either with or without corticosteroids. In this review, we discuss the evolving perspective on surgical treatment, specifically ETOCD, for the management of patients with TON and focus mainly on the therapeutic efficacy, safety, and resulting prognosis in the clinic.

Combination analysis on the impact of the initial vision and surgical time for the prognosis of indirect traumatic optic neuropathy after endoscopic transnasal optic canal decompression.

To analyze the impact of the initial vision and surgical time for endoscopic transnasal/transethmosphenoid optic canal decompression (ETOCD) in the treatment of indirect traumatic optic neuropathy (TON). This retrospective case series analysis included 72 patients with indirect TON who underwent ETOCD from August 2017 to May 2019. Visual acuity (VA) was compared before and after surgery to estimate the improvement rate. The overall VA improvement rate of ETOCD was 54.2%. There were 83.3% and 33.3% improvement rate of patients with residual vision and blindness, respectively. VA was improved in 60.9% of patients treated within 3 days, 61.5% treated within 7 days, and 35.0% treated later than 7 days. Of the blindness patients, 50.0%, 37.5%, and 0.0% were treated within 3 days, 3-7 days, and later than 7 days, respectively. Of patients with residual vision, 85.7%, 92.3%, and 70.0% were treated within 3 days, 3-7 days, and later than 7 days, respectively. A statistically significant difference was found between patients with residual vision and those with blindness (P < 0.01), as well as between patients who received ETOCD within 7 days and those who received ETOCD later than 7 days (P = 0.043). The improvement rate of blindness patients managed within 3 days (P = 0.008) and 3-7 days (P = 0.035) was significantly higher than that for patients managed beyond 7 days. Indirect TON patients can directly benefit from ETOCD, and patients with residual vision have better improvement rates. ETOCD should be performed as soon as possible to salvage the patient's VA, especially within the first 7 days. For blindness patients, it is necessary to carry out the surgery within 7 days with increased benefit seen before 3 days.

Manipulation of femtosecond laser filamentation by a gaseous lattice.

Manipulation of femtosecond laser filamentation is essential for many potential applications. We report the simulations of the manipulation of femtosecond laser filamentation by introducing a novel gaseous lattice medium with the alternating positive and negative refractive index distribution at different stages of filamentation. The results show that the filament length has greatly been extended and a multi-filament array can be formed by the gas lattice medium. It has been found that additional focusing and discrete diffraction provided by the gas lattice medium contribute to a new dynamic equilibrium in the filamentation. As a result, a varied cross-section pattern, higher field intensity, and electron density along the filamentation are obtained. Our approach provides a new way to manipulate filamentation for many practical photonic applications.