Search Results (10)

Background: Ciprofloxacin (CIP) is a poorly water-soluble fluoroquinolone-type antibiotic that can be useful in the treatment of lung infections. When the drugs are delivered directly to the lungs, a smaller dosage is needed to achieve the desired effect compared to the oral administration. Moreover, the application of nanoparticles potentially enhances the effectiveness of the treatments while lowering the possible side effects. Therefore, we aimed to develop a “nano-in-micro” structured dry powder inhaler formulation containing CIP. Methods: A two-step preparation method was used. Firstly, a nanosuspension was first prepared using a high-performance planetary mill by wet milling. After the addition of different additives (leucine and mannitol), the solid formulations were created by spray drying. The prepared DPI samples were analyzed by using laser diffraction, nanoparticle tracking analysis, scanning electron microscopy, X-ray powder diffraction, and differential scanning calorimetry. The solubility and in vitro dissolution tests in artificial lung fluid and in vitro aerodynamic investigations (Spraytec^® device, Andersen Cascade Impactor) were carried out. Results: The nanosuspension (D50: 140.0 ± 12.8 nm) was successfully prepared by the particle size reduction method. The DPIs were suitable for inhalation based on the particle diameter and their spherical shape. Improved surface area and amorphization after the preparation processes led to faster drug release. The excipient-containing systems were characterized by large lung deposition (fine particle fraction around 40%) and suitable aerodynamic diameter (between 3 and 4 µm). Conclusions: We have successfully formulated a nanosized antibiotic-containing formulation for pulmonary delivery, which could provide a potential treatment for patients with different respiratory infections. Full article

Electric multirotor plant protection unmanned aerial vehicles (UAVs) are widely used in China for efficient and precise plant protection at low altitude for low volumes. Unstructured farmland in China has various types of obstacles, and UAVs usually use a detour path to avoid obstacles due to flight altitude limitations. However, existing UAV spray systems do not spray when in obstacle neighborhoods during obstacle avoidance, resulting in insufficient droplet coverage and reduced plant protection quality in the area. To improve the droplet coverage in obstacle neighborhoods, this article carries out a study of side spray technology with an electric quadrotor UAV, and proposes the design and development of a side spray device. The relationship between the obstacle avoidance path of the UAV and the spray pattern of the side spray device and their effect on droplet coverage in obstacle neighborhoods was explored. An accurate measurement method of the relative position between the UAV and obstacles was proposed. Spray angle calculations and nozzle selection for the side spray device were carried out in conjunction with the relative position. A rotor wind field simulation model was designed based on the lattice Boltzmann method (LBM), and the spatial layout of the side spray device on the UAV was designed based on the simulation results. To explore suitable spray patterns for the side spray device, comparative experiments of droplet coverage in obstacle neighborhoods were carried out under different environments, spray patterns, and flight parameter combinations. The relationship between the flight parameter combinations and the distribution uniformity of droplets and the effective swath width of the side spray device was explored. The experimental results were analyzed by an analysis of variance (ANOVA) and a relationship model was obtained. The results showed that the side spray device can effectively improve droplet coverage in obstacle neighborhoods compared to a device without side spray using the same flight parameter combinations. The effective swath width in obstacle neighborhoods can be increased by a minimum of 6.35%, maximum of 35.32%, and average of 15.25% using the side spray device. The error between the predicted values of the relational model and the field experiment results was less than 15%. The results verify the effectiveness and rationality of the method proposed in this article. This study can provide technical and theoretical references for improving the plant protection quality of UAVs in obstacle environments. Full article

Active medical devices rely on a source of energy that is applied to the human body for specific purposes such as electrosurgery, ultrasounds for breaking up kidney stones (lithotripsy), laser irradiation, and other medical techniques and procedures that are extensively used. These systems must provide adequate working power with a commitment not to produce side effects on patients. Therefore, the materials used in these devices must effectively transmit energy, allow for security control, sense real-time variations in case of any issues, and ensure the implementation of closed-loop systems for control. This work extends to the experimental data adjustment of some different coating techniques based on plasma electro-oxidation (PEO) and thermal spray (TS) using fractional-order models. According to the physical structure of the coating in different coating techniques, Cole family models were selected. The experimental data were obtained by means of a vector network analyzer (VNA) in the frequency spectrum from 0.3 MHz to 5 MHz. The results show that some models from the Cole family (the single-dispersion model and inductive model) offered a goodness of fit to the experimental impedance in terms of RMSE error and a squared error R² close to unity. The use of this type of fractional-order electrical model allows an adjustment with a very small number of elements compared to integer-order models, facilitating its use and a consequent reduction in instrumentation cost and the development of control devices that are more robust and easily miniaturized for embedded applications. Additionally, fractional-order models allow for more accurate assessment in industrial and medical applications. Full article

Airborne particles containing pathogens such as bacteria (e.g., M. tuberculosis) or virions (e.g., influenza or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)) can cause infections. It has been speculated that the outflow from indoor air purifiers with a directional outlet could entrain and spread pathogen-containing aerosol particles. To date, only the case of indoor air purifiers with a directional outflow has been considered, and here we investigate an indoor air purifier with a circumferential outflow diffuser—an alternative design solution that is already commercially available. We measured the airflow velocity at two different angles to the surface of the circumferential outflow diffuser and two blower speeds. We visualized in scattered light the deflection of a vertical mist spray cone from a sneeze-simulating nebulizer parallel to the side of the air purifier. We found a significant difference in airflow velocities for different angles to the circumferential outflow diffuser: 0.01–0.02 m/s for 0° vs. 0.01–0.65 m/s for 45° at 1 m distance. We observed no significant deflection of the sneeze-simulating spray cone at the minimum blower speed and a 5 cm deflection at the maximum speed. The deflection of the sneeze-simulating spray mist particles by the tested indoor air purifier with the circumferential outflow, under the experimental conditions, is low relative to the recommended safer distances between people in indoor spaces. We conclude that indoor air purifiers with circumferential outflow diffusers have a lower potential to spread infectious aerosols in indoor spaces compared to devices with unidirectional outflow. Full article

The p-Si/n-MgZnO:Er/Ga₂O₃/ZnO:In diodes with different Ga₂O₃ thicknesses were fabricated through spray pyrolysis deposition at 450 °C with aqueous solutions containing magnesium nitrate, zinc acetate, erbium acetate, gallium nitrate, and indium nitrate precursors. The effects of Ga₂O₃ layer thickness on the diode properties were investigated. For the deposited films, a combined tiny hexagonal slices and small blocks surface morphology was characterized by scanning electron microscopy for all samples. Diodes were formed after In and Ag deposition on the back side and top side, respectively. The current-voltage characteristics and luminescence spectra are studied. With the increasing of Ga₂O₃ thickness, the diode forward bias resistance increases while the reverse biased dark current shows the decrease-increase characters. The Er ion corresponded green light emission was characterized for the diode under reverse biased breakdown condition. The increased luminescent intensity with low turn-on current behaviors was characterized by the diode with a Ga₂O₃ thickness of 4.9 nm. With the diode electrical and luminescence analysis, the effect of the Ga₂O₃ barrier layer on the diode was discussed. The Ga₂O₃ barrier layer improves performance for rare earth-related light-emitting devices. Full article

In this paper, we report a fast, linear wide-range hybrid flexible sensor based on a novel composite of strontium titanate (SrTiO₃) and poly 3,4 ethylenedioxythiophene polystyrene sulfonate (PEDOT: PSS) as a sensing layer. Inter-digitate electrodes (IDEs) were printed for humidity monitoring (finger: 250 µm; spacing: 140 µm; length: 8 mm) whilst a meander-based pattern was printed for the temperature measurement (meander thickness: 180 µm; spacing: 400 µm) on each side of the PET substrate using silver ink. Moreover, active layers with different concentration ratios were coated on the electrodes using a spray coating technique. The as-developed sensor showed an excellent performance, with a humidity measurement range of (10–90% RH) and temperature measurement range of (25–90 °C) with a fast response (humidity: 5 s; temperature: 4.2 s) and recovery time (humidity: 8 s; temperature: 4.4 s). The reliability of the sensor during mechanical bending of up to 5.5 mm was validated with a reliable performance. The sensor was also used in real-world applications to measure human respiration. For this, a suggested sensor-based autonomous wireless node was included in a 3D-printed mask. The manufactured sensor was an excellent contender for wearable and environmental applications because of its exceptional performance, which allowed for the simultaneous measurement of both quantities by a single sensing device. Full article

The codling moth (Cydia pomonella) is probably the most harmful pest in apple and pear orchards. The crop loss due to the high harmfulness of the insect can be extremely expensive; therefore, sophisticated pest management is necessary to protect the crop. The conventional monitoring approach for insect swarming has been based on traps that are periodically checked by human operators. However, this workflow can be automatized. To achieve this goal, a dedicated image capture device and an accurate insect counter algorithm are necessary which make online insect swarm prediction possible. From the hardware side, more camera-equipped embedded systems have been designed to remotely capture and upload pest trap images. From the software side, with the aid of machine vision and machine learning methods, traditional (manual) identification and counting can be solved by algorithm. With the appropriate combination of the hardware and software components, spraying can be accurately scheduled, and the crop-defending cost will be significantly reduced. Although automatic traps have been developed for more pest species and there are a large number of papers which investigate insect detection, a limited number of articles focus on the C. pomonella. The aim of this paper is to review the state of the art of C. pomonella monitoring with camera-equipped traps. The paper presents the advantages and disadvantages of automated traps’ hardware and software components and examines their practical applicability. Full article

An ultrasonic spray pyrolysis (USP) device consists of an evaporation and two reaction zones of equal length, into which an aerosol with a precursor compound enters, and where nanoparticles are formed in the final stage. As part of this research, we simulated the geometry of a side inlet, where the reaction gas (H₂) enters into the reaction tube of the device by using numerical methods. Mixing with the carrier gas (N₂) occurs at the entry of the H₂. In the initial part, we performed a theoretical calculation with a numerical simulation using ANSYS CFX, while the geometries of the basic and studied models were prepared with Solidworks. The inlet geometry of the H₂ included a study of the position and radius of the inlet with respect to the reaction tube of the USP device, as well as a study of the angle and diameter of the inlet. In the simulation, we chose the typical flows of both gases (N₂, H₂) in the range of 5 L/min to 15 L/min. The results show that the best geometry is with the H₂ side inlet at the bottom, which the existing USP device does not allow for. Subsequently, temperature was included in the numerical simulation of the basic geometry with selected gas flows; 150 °C was considered in the evaporation zone and 400 °C was considered in the other two zones—as is the case for Au nanoparticle synthesis. In the final part, we performed an experiment on a USP device by selecting for the input parameters those that, theoretically, were the most appropriate—a constant flow of H₂ 5 L/min and three different N₂ flows (5 L/min, 10 L/min, and 15 L/min). The results of this study show that numerical simulations are a suitable tool for studying the H₂ flow in a UPS device, as the obtained results are comparable to the results of experimental tests that showed that an increased flow of N₂ can prevent the backflow of H₂ effectively, and that a redesign of the inlet geometry is needed to ensure proper mixing. Thus, numerical simulations using the ANSYS CFX package can be used to evaluate the optimal geometry for an H₂ side inlet properly, so as to reconstruct the current and improve future USP devices. Full article

Biological dressings such as collagen and hyaluronic acid represent the main advanced tools that plastic surgeons, dermatologists and vulnologists use today to treat chronic wounds or ulcers that do not tend to heal. These types of dressings are important because they create a moist and physiological interface at the wound level, are of natural origin, easy to use, hypo-allergenic, economical and do not create discomfort for the patient during dressing changes. We treated 128 patients (divided into four groups based on type of dressing) with non-complex superficial chronic wounds in comparison with a traditional dressing (fitostimoline gauze or polyurethane foam). We analyzed wound characteristics, healing time, and operator and patient satisfaction. A significantly higher recovery rate was observed in the “Collagen-coated plates” treatment group compared to Standard Treatment. Additionally, a significantly higher probability of recovery was observed compared to the alternative two experimental devices (Collagen-coated plates + HA and Collagen-based spray). However, the main limitation of the randomization of this study is the presence in the “Collagen-based spray” group of localized wounds, mainly in the fingers and hand. No side effects were reported in relation to the procedures or the experimental products. Collagen may be considered as a valuable therapeutic tool in non-complex chronic wounds by virtue of its low immunogenicity, flexibility and applicability in biocompatible scaffolds, and represents driving force toward enhanced wound care. Full article

Roflumilast is currently administered orally to control acute exacerbations in chronic obstructive pulmonary disease (COPD). However, side effects such as gastrointestinal disturbance and weight loss have limited its application. This work aimed to develop an inhalable roflumilast formulation to reduce the dose and potentially circumvent the associated toxicity. Roflumilast was cospray-dried with trehalose and L-leucine with varied feed concentrations and spray-gas flow rates to produce the desired dry powder. A Next-Generation Impactor (NGI) was used to assess the aerosolization efficiency. In addition, different devices (Aerolizer, Rotahaler, and Handihaler) and flow rates were used to investigate their effects on the aerosolization efficiency. A cytotoxicity assay was also performed. The powders produced under optimized conditions were partially amorphous and had low moisture content. The powders showed good dispersibility, as evident by the high emitted dose (>88%) and fine particle fraction (>52%). At all flow rates (≥30 L/min), the Aerolizer offered the best aerosolization. The formulation exhibited stable aerosolization after storage at 25 °C/15% Relative Humidity (RH) for one month. Moreover, the formulation was non-toxic to alveolar basal epithelial cells. A potential inhalable roflumilast formulation including L-leucine and trehalose has been developed for the treatment of COPD. This study also suggests that the choice of device is crucial to achieve the desired aerosol performance. Full article