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Femtosecond-laser-assisted material restructuring employs extreme optical intensities to localize the ablation regions. To overcome the minimum feature size limit set by the wave nature of photons, there is a need for new approaches to tailored material processing at the nanoscale. Here, we report the formation of deeply-subwavelength features in silicon, enabled by localized laser-induced phase explosions in prefabricated silicon resonators. Using short trains of mid-infrared laser pulses, we demonstrate the controllable formation of high aspect ratio (>10:1) nanotrenches as narrow as [Formula: see text]. The trench geometry is shown to be scalable with wavelength, and controlled by multiple parameters of the laser pulse train, such as the intensity and polarization of each laser pulse and their total number. Particle-in-cell simulations reveal localized heating of silicon beyond its boiling point and suggest its subsequent phase explosion on the nanoscale commensurate with the experimental data. The observed femtosecond-laser assisted nanostructuring of engineered microstructures (FLANEM) expands the nanofabrication toolbox and opens exciting opportunities for high-throughput optical methods of nanoscale structuring of solid materials.

Objective To investigate the clinical characteristics of the hepatolenticular degeneration in children, and to clarify the significance of gene diagnosis in children with hepatolenticular degeneration. Methods A total of 75 patients with hepatolenticular degeneration were enrolled in the Department of Pediatrics, Peking Union Medical College Hospital from 2011 to 2018. All of them carried out a generation of gene sequencing for ATPase Cu2+ transporting beta polypeptide (ATP7B) gene and multiplex ligation-dependent probe amplification (MLPA) analysis. Results Among the 75 pediatric patients, 55 patients were asymptomatic and had elevated aminotransferases as the incidental findings. All the pediatric patients had decreased ceruloplasmin. Seventy-two of pediatric patients had 24-hour urinary copper＞40 μg/d. There were 16 cases that had Kayser-Fleischer(K-F) rings. Sixteen six out of 75(21.33%)cases were diagnosed clinically and 15 cases were＞7 years old. All the remaining patients needed genetic diagnosis. Sixty-six patients had two mutations and 9 patients had only one mutation, 1 had no mutation. Forty eight different mutations were found to be localized in ATP7B gene. These mutations included 32 missense mutations, 6 splice mutations, 5 deletion mutations, 2 repeated mutations, 2 insert mutations and 1 nonsense mutations. The most frequently three mutations were c.2333G＞T,p.R778L,c.2621C＞T, p.A874V,c.2975C＞T, p.P992L,whose allele frequencies were 30.49%,14.89%,9.92%. Conclusions The research showed that in young aged patients, the nervous system symptoms are not obvious and the positive rate of laboratory tests are lower than adults so is a challenge to clinical diagnosis. So Genetic testing is of great significance for the early diagnosis and early treatment of disease in pediatric patients.

Objective To investigate the effect of medical ozone injection therapy on temporomandibular joint (TMJ) osteoarthritis and its pain in SD rats. Methods Fifity-four rats were randomly assigned according to a random number table into three groups: control group, model group, and medical ozone group, with 18 rats in each group. In the control group, only physiological saline was injected during modeling; in the model group, only sodium iodoacetate was injected for modeling; in the medical ozone group, after injecting sodium iodoacetate into the joint cavity for modeling for one week, medical ozone was then injected into the joint cavity for intervention at a frequency of once a week, totaling 5 times. One week (week 2 after modeling), 3 weeks (week 4 after modeling), and 5 weeks (week 6 after modeling) after medical ozone injections, 6 rats from each group were euthanized. Mechanical withdrawal threshold of rats in each group was assessed before euthanasia, and the expression levels of interleukin-1β (IL-1β) in joint fluid of rats in each group were measured after euthanasia. Gross observation and modified Mankin’s scoring were performed on TMJ cartilage of rats in each group after stained with Pelletier score and Safranin O-Fast Green. Results During the same time period, compared to the control group, the model group showed a significant decrease in the mechanical pain threshold of the TMJ in rats at 1 week, 3 weeks, and 5 weeks (P0.05).Within the medical ozone group, compared to the 1-week treatment, the mechanical pain threshold of the TMJ increased (P0.05) between different treatment duration.Additionally, there were no statistically significant differences in the mechanical pain threshold of the TMJ, expression levels of IL-1β in the TMJ fluid, Pelletier score, and modified Mankin’s score of TMJ cartilage between the medical ozone group at 3 weeks and 5 weeks (P>0.05). Conclusion Medical ozone treatment for more than 3 weeks can improve temporomandibular joint osteoarthritis and its associated pain in rats.

BackgroundThe defects generated during the working process of metal materials have a significant impact on their performance. For example, the radiation-induced embrittlement and hardening of reactor pressure vessel (RPV) steels are a factor of concern, which hinders the life extension of the RPV. Annealing treatment is applied to alleviating irradiation-induced precipitates and defects and recover RPV's mechanical properties in the past few decades to extend the in-service lifetime of the RPV. Unfortunately, this conventional method generally requires a high treatment temperature and long operation time, inevitably wasting considerable energy due to the huge size of the RPV. Recently, as a more convenient and energy-saving method, the repair of metal defects by electropulsing treatment (EPT) has been developed.PurposeThis study aims to design and construct a device for EPT processing of samples, and investigate the repairs of defects in electron irradiated and deformed iron and RPV steel after EPT by using positron lifetime spectroscopy.MethodsElectron irradiated pure iron and RPV steel samples were prepared and subjected to multi parameter EPT device developed in laboratory, and the changes in defects of the samples with EPT were characterized by positron lifetime spectroscopy. In addition, the mechanical properties of pure iron tensile samples were characterized by micro Vickers hardness, and the defect information was characterized by positron lifetime spectroscopy to explore the relationship between macroscopic properties and microstructure.ResultsThe defects introduced by electron irradiation in pure iron and RPV steel samples gradually recover after EPT and exhibit similar patterns to annealing treatment. After stretching, the number of defects in pure iron samples increases, leading to an increase in Vickers hardness. EPT can restore defect and reduce Vickers hardness.ConclusionsThe defects generated by irradiation or deformation in pure iron and RPV steel can be partially repaired through EPT. The effect of defect repair is not only related to the initial state of the sample, but also to EPT's parameters. As a new non-destructive testing method, positron annihilation is expected to provide a criterion for material damage or defect repair under the action of pulse current, which can conveniently, quickly, and sensitively detect the defect state of actual working components.

Conventional inorganic nanowire (NW) fibers are usually not stretchable and elastic, which may limit their practical applications. Inspired by the similarity between inorganic sub-1 nm NWs and polymer chains in dimension, and helical spring-like structure of cellulose in cherry bark, highly flexible and stretchable NW superlattice fibers composed of sub-1 nm GdOOH NWs are fabricated. The NW fibers could be twined, bent, twisted, and tied without any damage. When the strain is less than 10%, the fibers present elastic deformation. The elongation at break of the fibers usually reaches ≈40–50% and the highest elongation could reach ≈86%. Excellent flexibility and stretchability of the NW fibers are attributed to the well-aligned spring-like NWs assembled superlattice, which are demonstrated by scanning electron microscopy tests, synchrotron small-angle X-ray scattering, and obvious birefringence. Moreover, NW-nanoparticle (NP) fibers are fabricated, inspired by inorganic nanoparticle–reinforced polymers. The strength is improved compared with the NW fibers. Based on this work, it is possible to fabricate multifunctional, flexible, and stretchable inorganic NW materials composed of different inorganic sub-1 nm NWs, which may be useful in practical applications.