Search Results (35)

Background/Objectives: Ventriculoperitoneal shunting is a validated procedure for the treatment of idiopathic normal-pressure hydrocephalus. To select shunt-responsive patients, infusion and tap tests can be used. Only gait is evaluated after the procedure to establish a potential improvement. In this study, we present our Hydro-Real-Time Neuropsychological Testing protocol to assess the feasibility of performing an ultra-fast assessment of patients during the infusion and tap test. Methods: We tested 57 patients during the infusion and tap test to obtain real-time feedback on their cognitive status. Data were obtained immediately before the infusion phase (T0), when the pressure plateau was reached (T1), and immediately after cerebrospinal fluid subtraction (T2). Based on cerebrospinal fluid dynamics, 63.15% of the patients presented a resistance to outflow > 12 mmHg/mL/min, while 88% had a positive tap test response. Results: Compared to T0, cerebrospinal fluid removal significantly improved performance on tasks exploring executive functions (counting backward, p < 0.001; verbal fluency, p < 0.001). Patients were significantly faster at counting backward at T2 vs. T1 (p < 0.05) and at T2 vs. T0 (p < 0.001) and were significantly faster at counting forward at T2 vs. T1 (p < 0.005), suggesting an improvement in speed at T2. There was a significantly smaller index at T1 vs. T0 (p = 0.005) and at T2 vs. T0 (p < 0.001), suggesting a more marked improvement in patients’ executive abilities at T2 and a smaller improvement at T1. Regarding verbal fluency, patients were worse at T1 vs. T0 (p < 0.001) and at T2 vs. T0 (p < 0.001). Conclusions: Patients’ performance can be monitored during the infusion and tap test as significant changes in executive functions are observable. In future, this protocol might help improve patients’ selection for surgery. Full article

The efficient removal of dyes is of significant importance for environmental purification and human health. In this study, a novel material (Si-MPTS-IL) has been synthesized by the immobilization of imidazole ionic liquids (ILs) onto nano-silica using the radiation grafting technique. The adsorption performance of Si-MPTS-IL for Coomassie Brilliant Blue (CBB) removal is studied by a series of static adsorption experiments. It is found that Si-MPTS-IL has ultra-fast adsorption kinetics, reaching equilibrium within 2 min. The adsorption process for CBB conforms to the Langmuir model. In addition, Si-MPTS-IL exhibits a negligible impact on the adsorption efficiency of CBB with the increase in salt concentration. After six cycles of adsorption–desorption, the adsorption efficiency of Si-MPTS-IL remained above 80%, indicating excellent regenerative properties and a promising candidate for the treatment of wastewater containing CBB. A study of the mechanism indicates that the CBB capture by Si-MPTS-IL can be attributed to the synergistic effects of electrostatic interactions and pore filling. Full article

The rapid, efficient, and thorough degradation of Bisphenol A (BPA) is challenging. In this study, we prepared an effective peroxymonosulphate (PMS) activation catalyst derived from sawdust containing calcium carbonate. The Co and Cu co-doped sawdust biochar (CoO/CuO@CBC) catalyst could activate PMS quickly, and the degradation rate of BPA reached 99.3% in 5 min, while the rate constant was approximately 30 times higher than in the CBC/PMS and CoCuO_x/PMS systems. Moreover, the interaction between CoO, CuO, and CBC endows the CoO/CuO@CBC catalyst with excellent catalytic performance under different conditions, such as initial pH, temperature, water matrix, inorganic anions, and humic acid, which maintained fast PMS activation via the cyclic transformation of Cu and Co for BPA degradation. The results demonstrated that both the radical (•O₂⁻ and •SO₄⁻) and non-radical (¹O₂) pathways participate in the degradation of BPA in the CoO/CuO@CBC/PMS system. The efficient and stable degradation over a wide range of pH, temperature, and aqueous matrices indicates the potential application of the CoO/CuO@CBC catalyst. Full article

The dissociative ionization of molecular IBr in a near-infrared femtosecond laser field was investigated through the utilization of the DC-sliced ion imaging technique. Two pathways, denoted as (1, 0)^a and (1, 0)^b, were observed in the dissociation process of IBr⁺ into an I⁺ ion and Br atom. The distinct angular distributions observed in these pathways were found to be a result of the removal of electrons from different molecular orbitals. Specifically, in pathway (1, 0)^a, the electron was stripped from HOMO and HOMO-1, while in pathway (1, 0)^b, the electron was removed from HOMO-2. The ultrafast dynamical processes of molecules influenced by intense femtosecond laser fields were investigated through an analysis of the angular distribution characteristics of fragment ions in conjunction with the spatial properties of molecular orbitals. Full article

Traditional separation membranes used for dye removal often suffer from a trade-off between separation efficiency and water permeability. Herein, we propose a facile approach to prepare cyclodextrin-based high-flux nanofiber membranes by electrospinning and vapor-driven crosslinking processes. The application of glutaraldehyde vapor for crosslinking hydroxypropyl-β-cyclodextrin (HP-β-CD)/polyvinyl alcohol (PVA)/laponite electrospun membranes can build interconnected structures and lead to the formation of a porous hierarchical layer. In addition, the incorporation of inorganic salt, laponite, can alter the crosslinking process, resulting in membranes with improved hydrophilicity and highly maintained electrospun nanofibrous morphology, which contributes to an ultrafast water flux of 1.0 × 10⁵ Lh⁻¹m⁻²bar⁻¹. Due to the synergetic effect of strong host–guest interaction and electrostatic interaction, the membranes exhibit suitable rejection toward anionic dyes with a high removal efficiency of >99% within a short time and achieve accurate separation for cationic against anionic dyes, accompanied by suitable recyclability with >97% separation efficiency after at least four separation–regenerations. The prepared membranes with remarkable separation efficiency and ultrafast permeation properties might be a promising candidate for high-performance membranes in water treatment. Full article

Silicon carbide (SiC) is a promising semiconductor material as well as a challenging material to machine, owing to its unique characteristics including high hardness, superior thermal conductivity, and chemical inertness. The ultrafast nature of femtosecond lasers enables precise and controlled material removal and modification, making them ideal for SiC processing. In this review, we aim to provide an overview of the process properties, progress, and applications by discussing the various methodologies involved in femtosecond laser processing of SiC. These methodologies encompass direct processing, composite processing, modification of the processing environment, beam shaping, etc. In addition, we have explored the myriad applications that arise from applying femtosecond laser processing to SiC. Furthermore, we highlight recent advancements, challenges, and future prospects in the field. This review provides as an important direction for exploring the progress of femtosecond laser micro/nano processing, in order to discuss the diversity of processes used for manufacturing SiC devices. Full article

The rate of the removal of materials coated with nano−crystalline diamonds by femtosecond laser etching was examined by adjusting the repetition rate of the femtosecond laser, the energy−flux density of the concentrated spot, and the scanning speed. The observational results of the white-light interferometer and the numerical fitting approach were used to develop the removal rate function model of the nano-crystalline diamond-covered material etched by the femtosecond laser. The findings demonstrated that the rate of material removal was not greatly affected by the repetition frequency and that the amount of laser energy accumulated over time on the coated surface is steady. The processing outcomes under different laser scanning speeds are different, and the material removal rate tends to increase and then decrease with an increase in scanning speed. The greater the energy−flux density of the focused spot, the greater the etching intensity, and the greater the material removal rate. With an increase in scanning speed, the rate at which the material is removed often rises initially before falling. Full article

In a foggy traffic environment, the vision sensor signal of intelligent vehicles will be distorted, the outline of obstacles will become blurred, and the color information in the traffic road will be missing. To solve this problem, four ultra-fast defogging strategies in a traffic environment are proposed for the first time. Through experiments, it is found that the performance of Fast Defogging Strategy 3 is more suitable for fast defogging in a traffic environment. This strategy reduces the original foggy picture by 256 times via bilinear interpolation, and the defogging is processed via the dark channel prior algorithm. Then, the image after fog removal is processed via 4-time upsampling and Gaussian transform. Compared with the original dark channel prior algorithm, the image edge is clearer, and the color information is enhanced. The fast defogging strategy and the original dark channel prior algorithm can reduce the defogging time by 83.93–84.92%. Then, the image after fog removal is inputted into the YOLOv4, YOLOv5, YOLOv6, and YOLOv7 target detection algorithms for detection and verification. It is proven that the image after fog removal can effectively detect vehicles and pedestrians in a complex traffic environment. The experimental results show that the fast defogging strategy is suitable for fast defogging in a traffic environment. Full article

When volatile alkenes are emitted into the atmosphere, they are rapidly removed by oxidizing agents such as hydroxyl radicals and ozone. The latter reaction is termed ozonolysis and is an important source of Criegee intermediates (CIs), i.e., carbonyl oxides, that are implicated in enhancing the oxidizing capacity of the troposphere. These CIs aid in the formation of lower volatility compounds that typically condense to form secondary organic aerosols. CIs have attracted vast attention over the past two decades. Despite this, the effect of their substitution on the ground and excited state chemistries of CIs is not well studied. Here, we extend our knowledge obtained from prior studies on CIs by CF₃ substitution. The resulting CF₃CHOO molecule is a CI that can be formed from the ozonolysis of hydrofluoroolefins (HFOs). Our results show that the ground state unimolecular decay should be less reactive and thus more persistent in the atmosphere than the non-fluorinated analog. The excited state dynamics, however, are predicted to occur on an ultrafast timescale. The results are discussed in the context of the ways in which our study could advance synthetic chemistry, as well as processes relevant to the atmosphere. Full article

The study investigates the two different underlying ablation mechanisms of WS₂ processed by femtosecond (fs) laser with different fluences. With increasing fluence, the saturable expansion of craters and the transformation of three distinct crater morphologies are found. The material response and the transfer and deposition of laser energy are tracked by using a plasma model based on the classical single rate equation model and the Drude model. The results of the numerical simulation and time-resolved transient reflectivity reveal the two different ablation mechanisms, which are coulomb explosion and phase explosion. The mechanism of material removal is distinguished by the critical threshold of 0.85 J/cm². In addition, the internal ablation region exhibits a high concentration of defects and WO₃ according to the results of Raman spectra, X-ray photoelectron spectra, and morphology-dependent photoluminescence mapping. Due to the high concentration with high fluence, the device of WS₂/Si p-n junction exhibits a 2.6 times enhancement on the current under forward bias. The findings would be of value to engineer structures to tailor the optoelectronic response of WS₂ and to develop potential future optoelectronic devices. Full article

Strontium, the main component of radioactive nuclear wastewater, is characterized by a high fission yield and an extended half-life. It is easily absorbed by the human body, thus greatly threatening the environment and the human body. In this study, a mesoporous composite phase sodium superionic conductor (NVP@NMP) was synthesized by the droplet template method, and the rapid capture of Sr²⁺ from wastewater was achieved by constructing a nano-heterogeneous interface to increase the ion diffusion rate. NVP@NMP showed efficient and rapid removal of strontium ions in adsorption kinetics, isothermal adsorption, solution pH, and interfering ions concentration tests, especially using the equilibrium time of 2 min for strontium absorption by NVP@NMP and a maximum theoretical adsorption capacity of 361.36 mg/g. The adsorption process was spontaneous, endothermic, and feasible. At higher concentrations of other competing ions (Na, K, Ca, Mg, and Cs), the adsorbent exhibited higher selectivity towards Sr²⁺.TEM, XPS, and XRD analyses revealed that ion exchange was the main mechanism for the NVP@NMP ultrafast adsorption of Sr²⁺. In this research, we investigated the feasibility of ultrafast strontium capture by sodium superionic conductor structured phosphates and explained the ultrafast strontium adsorption mechanism of NASICON materials through XPS. Full article

Organic polymers are widely explored due to their high stability, scalability, and more facile modification properties. We developed cost-effective dithiocarbamate-based organic polymers synthesized using diamides, carbon disulfide, and diamines to apply for environmental remediation. The sequestration of radioiodine is a serious concern to tackle when dealing with nuclear power for energy requirements. However, many of the current sorbents have the problem of slower adsorption for removing iodine. In this report, we discuss the utilization of an electron-rich dithiocarbamate-based organic polymer for the removal of iodine in a very short time and with high uptake. Our material showed 2.8 g/g uptake of vapor iodine in 1 h, 915.19 mg/g uptake of iodine from cyclohexane within 5 s, 93% removal of saturated iodine from water in 1 min, and 1250 mg/g uptake of triiodide ions from water within 30 s. To the best of our knowledge, the iodine capture was faster than previously observed for any existing material. The material was fully recyclable when applied for up to four cycles. Hence, this dithiocarbamate-based polymer can be a promising system for the fast removal of various forms of iodine and, thus, enhance environmental security. Full article

Due to the inability of conventional wastewater treatment procedures to remove organic pharmaceutical pollutants, active pharmaceutical components remain in wastewater and even reach tap water. In terms of pharmaceutical pollutants, the scientific community focuses on β-blockers due to their extensive (over)usage and moderately high solubility. In this study, the photocatalytic activity of V₂O₅ was investigated through the degradation of nadolol (NAD), pindolol (PIN), metoprolol (MET), and their mixture under ultraviolet (UV) irradiation in water. For the preparation of V₂O₅, facile hydrothermal synthesis was used. The structural, morphological, and surface properties and purity of synthesized V₂O₅ powder were investigated by scanning electron microscopy (SEM), X-ray, and Raman spectroscopy. SEM micrographs showed hexagonal-shaped platelets with well-defined morphology of materials with diameters in the range of 10–65 µm and thickness of around a few microns. X-ray diffraction identified only one crystalline phase in the sample. The Raman scattering measurements taken on the catalyst confirmed the result of XRPD. Degradation kinetics were monitored by ultra-fast liquid chromatography with diode array detection. The results showed that in individual solutions, photocatalytic degradation of MET and NAD was relatively insignificant (<10%). However, in the PIN case, the degradation was significant (64%). In the mixture, the photodegradation efficiency of MET and NAD slightly increased (15% and 13%). Conversely, it reduced the PIN to the still satisfactory value of 40%. Computational analysis based on molecular and periodic density functional theory calculations was used to complement our experimental findings. Calculations of the average local ionization energy indicate that the PIN is the most reactive of all three considered molecules in terms of removing an electron from it. Full article

Blast waves generated by energetic materials involve very fast time variations in the pressure. One important issue for blast wave metrology is the accurate measurement (typical precision in the range of ±5% or better) of the static overpressure peak. For most near field configurations, this measurement requires ultra-fast sensors with response times lower than a few microseconds. In this paper, we design, model, fabricate and characterize a new ultra-fast sensor using piezo-resistive gauges at the center of a miniaturized and rectangular silicon membrane. When a pressure step of 10 bar is applied to the membrane, the signal delivered to the sensor output presents dampened oscillations, with a resonant frequency of 20.6 MHz and quality factor of 24,700 ns after the arrival of the shock wave. After removing undesirable drifts that appear after 700 ns, we may expect the sensor to have a response time (at ±5%) of 1.2 µs. Consequently, the proposed pressure sensor could be advantageously used for the accurate measurement of static overpressure peaks in blast wave experiments. Full article

Water pollution is a significant issue nowadays. Among the many different technologies for water purification, photocatalysis is a very promising and environment-friendly approach. In this study, the photocatalytic activity of Sr_0.9La_0.1TiO₃ (SLTO) and Sr_0.25Ca_0.25Na_0.25Pr_0.25TiO₃ (SCNPTO) nano-sized powders were evaluated by degradation of pindolol in water. Pindolol is almost entirely insoluble in water due to its lipophilic properties. The synthesis of the SCNPTO was performed using the reverse co-precipitation method using nitrate precursors, whereas the SLTO was produced by spray pyrolysis (CerPoTech, Trondheim Norway). The phase purity of the synthesized powders was validated by XRD, while HR-SEM revealed particle sizes between 50 and 70 nm. The obtained SLTO and SCNPTO powders were agglomerated but had relatively similar specific surface areas of about 27.6 m² g⁻¹ and 34.0 m² g⁻¹, respectively. The energy band gaps of the SCNPTO and SLTO were calculated (DFT) to be about 2.69 eV and 3.05 eV, respectively. The photocatalytic performances of the materials were examined by removing the pindolol from the polluted water under simulated solar irradiation (SSI), UV-LED irradiation, and UV irradiation. Ultra-fast liquid chromatography was used to monitor the kinetics of the pindolol degradation with diode array detection (UFLC–DAD). The SLTO removed 68%, 94%, and 100% of the pindolol after 240 min under SSI, UV-LED, and UV irradiation, respectively. A similar but slightly lower photocatalytic activity was obtained with the SCNPTO under identical conditions, resulting in 65%, 84%, and 93% degradation of the pindolol, respectively. Chemical oxygen demand measurements showed high mineralization of the investigated mixtures under UV-LED and UV irradiation. Full article