Liquid Delivery Research Articles

Continuous recovery of tellurium and cadmium from simulated CdTe leachates using a fixed-bed-column adsorption system

Rare element resource (Te) loss and heavy metal (Cd) pollution, derived from waste photovoltaic CdTe cells, have attracted considerable attention in the cleaner production and environmental protection field. However, there are several technical barriers in conventional adsorption strategies for the continuous recovery Te(Ⅳ) and Cd(Ⅱ) due to single-component recovery, inefficient adsorbent utilization and less automation. Herein, this work presented a fixed-bed-column adsorption system for the continuous adsorption recovery of tellurium and cadmium from a simulated CdTe leachate using functional sludge-based adsorption fillers (LDO/SF and EDTA@LDH/SF) that prepared from water-processing sludge via hydrothermal synthesis, thermal activation and surface modification technologies. Breakthrough curves were analyzed for adsorption columns, considering initial concentration, flow rate, and filler height, with parameters evaluated using the Thomas and BDST models to determine the optimal separation parameters. During the continuous adsorption process, the column adsorption system with the filler layer height of 4 cm and liquid delivery rate of 1 mL/min can be used for continuous separation of more than 1000 mL of a simulated CdTe leachate and exhibits adsorption efficiencies of more than 96% and 82% for Te(Ⅳ) and Cd(Ⅱ), respectively. More importantly, the elution procedure was used to treat the column adsorption system with ion adsorption acceptances of 83% and 90% for Te(Ⅳ) and Cd(Ⅱ), respectively. Meanwhile, the functional sludge-based fillers demonstrated great regeneration and recycling capabilities, thus maximizing the utilization of adsorbents and saving treatment costs. This study has established a robust technical solution for the continuous recovery of tellurium and cadmium from simulated leachates, providing a practical framework for evaluating the efficiency of adsorption filler columns in actual applications.

A new aerosol delivery approach for enhanced long-term respiratory care in resource-poor settings

Continuous aerosol therapy is safe, superior, and the mainstay in the therapy of patients with severe asthma, cystic fibrosis, chronic obstructive pulmonary disease (COPD), and coronavirus disease (COVID-19). However, continuous nebulization has been perceived as highly expensive and labor-intensive, which often requires specialized medical equipment. Moreover, it is difficult to maintain consistent aerosol output and particle size delivery over an extended period without operator intervention. This work proposes a simple and reliable continuous nebulization method using a conventional gas jet nebulizer and intravenous (IV) bottle/bag. The present work reports detailed experimental studies on a gas jet nebulizer with Particle image velocimetry (PIV), Particle/droplet Imaging Analysis (PDIA), and Mie scattering techniques to demonstrate the feasibility of the proposed technique. The preliminary investigation shows that the proposed method provides continuous liquid output delivery without external supervision. The liquid delivery rate and mass median diameter (MMD) of the nebulizer mainly depend on the gas flow rate and suction height. The MMD of the primary generated droplets is reported to vary between 100 and 230 μm for a ± 10 cm suction height and 500–1000 mlph nebulization gas flow rate. Most importantly, the nebulizer spray angle, stability, droplet size distribution, and the axial and radial velocities of the droplets are marginally affected by the suction height. Therefore, the proposed system is a versatile, safe, and cost-effective method of continuous nebulization therapy, especially in resource-poor countries or contagious disease outbreak situations.

Numerical analysis of bubble behavior in proton exchange membrane water electrolyzer flow field with serpentine channel

Green hydrogen, produced using renewable energy sources, represents a critical component in the transition to sustainable energy systems due to its clean and versatile nature. This research investigates the dynamic behavior of bubbles within the serpentine flow field of a Proton Exchange Membrane Water Electrolysis (PEMWE) cell, aiming to enhance the understanding of two-phase flow dynamics and improve the efficiency of green hydrogen production. Utilizing the Volume of Fluid (VOF) method, a three-dimensional unsteady model was developed to simulate the flow dynamics at the anode of a PEMWE system. The study explores the transition of bubbles from bubbly flow to slug and annular flow, highlighting the significant impact of bubble formation on mass transport and overall cell performance. The results demonstrate that larger bubbles impede liquid water delivery to reaction sites and cause unstable pressure drops. The investigation also examines the influence of wall contact angles on bubble behavior, revealing that hydrophobic surfaces lead to increased gas coverage and more oxygen accumulation inside the channel, which hinders mass transport. These findings underscore the necessity for optimized flow channel designs and enhanced surface treatments to mitigate bubble coalescence and improve PEMWE performance.

Laser-Constructed Bionic Composite Fog-Collecting Surfaces with Efficient Nucleation Sites and Enhanced Water Transport.

Fog collection effectively alleviates the current freshwater shortage; thus, enhancing its efficiency is crucial. Here, we report a novel bionic fog collection surface (Al@B-V) comprising composite superhydrophobic bumps integrated with superhydrophilic V-channel grooves. This surface, which has efficient fog nucleation points and enhanced water transport capabilities, effectively balances fog capture and water transport during the collection process, thereby achieving high-efficiency fog collection. Compared to ordinary aluminum-based surfaces, Al@B-V achieves a fog collection efficiency of up to 3.08 g·cm-2·h-1, three times higher than the original aluminum-based surface. Furthermore, the V-channel groove proposed in this study exhibits a water transport speed of up to 165 mm·s-1, which is remarkably approximately 80 times faster than the commonly used U-channel groove. Additionally, this V-channel groove can overcome gravity, transporting approximately 10 μL of liquid to the top even when placed at 90° inclination. It can directionally transport 10 μL of liquid over a distance of up to 151 mm on a plane. This novel microgroove design can be effectively applied in various fields, including liquid collection, directional transport, seawater desalination, microfluidics, and drug delivery.

Wirelessly Actuated Microfluidic Pump and Valve for Controlled Liquid Delivery in Dental Implants.

Enabling minimally invasive and precise control of liquid release in dental implants is crucial for therapeutic functions such as delivering antibiotics to prevent biofilm formation, infusing stem cells to promote osseointegration, and administering other biomedicines. However, achieving controllable liquid cargo release in dental implants remains challenging due to the lack of wireless and miniaturized fluidic control mechanisms. Here wireless miniature pumps and valves that allow remote activation of liquid cargo delivery in dental implants, actuated and controlled by external magnetic fields (<65 mT), are reported. A magnet-screw mechanism in a fluidic channel to function as a piston pump, alongside a flexible magnetic valve designed to open and close the fluidic channel, is proposed. The mechanisms are showcased by storing and releasing of liquid up to 52µL in a dental implant. The liquid cargos are delivered directly to the implant-bone interface, a region traditionally difficult to access. On-demand liquid delivery is further showed by a metal implant inside both dental phantoms and porcine jawbones. The mechanisms are promising for controllable liquid release after implant placement with minimal invasion, paving the way for implantable devices that enable long-term and targeted delivery of therapeutic agents in various bioengineering applications.

Pharmacokinetic and toxicological assessment of a solid self-microemulsifying drug delivery system (S-SMEDDS) of kaempferia parviflora in rats

Kaempferia parviflora (KP), renowned as an alternative medicine, has gained widespread acclaim for its efficacy in male sexual enhancement and anti-inflammatory applications. However, methoxyflavones, its primary compound, poses challenges due to inherent low water solubility and limited oral absorption. This study aims to develop a novel solid self-microemulsifying drug delivery system for KP (KPS-SMEDDS) and to investigate the pharmacokinetic profile and acute toxicity. The liquid self-microemulsifying drug delivery system for KP (KPL-SMEDDS) was formed by combining Neobee® M − 5 (90 %) with a mixture of surfactant (10 %) consisting of Kolliphor® EL and polyethylene glycol 400 in a ratio of 1:2. Consequently, the KPL-SMEDDS was transformed into a powdered form by employing Sipernat® 22S as an absorbent in a 1:1 ratio. The developed formulations were subsequently evaluated for their physicochemical properties, in vitro dissolution tests, and in vivo oral absorption in rats by using methoxyflavones as the markers for quantitation. The findings demonstrated that the use of KPL-SMEDDS and KPS-SMEDDS improved the dissolution rate of methoxyflavones in 0.1 N HCl in comparison to KP powder. Comparative analysis revealed that the KPS-SMEDDS exhibited a significantly higher maximum drug concentration (Cmax) and area under the curve (AUC) values in comparison to the conventional KP extract. Notably, the KPS-SMEDDS formulation at an oral dose of 250 mg/kg remarkably increased the bioavailability of polymethoxyflavones up to 2.7- to 3-fold. Furthermore, acute oral toxicity assessment revealed no statistically significant alterations in clinical observations or biochemical parameters. These compelling findings underlined the potential of the KPS-SMEDDS formulation to augment the absorption and bioavailability of methoxyflavones, establishing its safety as an oral supplement.

Empowering Exosomes with Aptamers for Precision Theranostics.

As information messengers for cell-to-cell communication, exosomes, typically small membrane vesicles (30-150nm), play an imperative role in the physiological and pathological processes of living systems. Accumulating studies have demonstrated that exosomes are potential biological candidates for theranostics, including liquid biopsy-based diagnosis and drug delivery. However, their clinical applications are hindered by several issues, especially their unspecific detection and insufficient targeting ability. How to upgrade the accuracy of exosome-based theranostics is being widely explored. Aptamers, benefitting from their admirable characteristics, are used as excellent molecular recognition elements to empower exosomes for precision theranostics. With high affinity against targets and easy site-specific modification, aptamers can be incorporated with platforms for the specific detection of exosomes, thus providing opportunities for advancing disease diagnostics. Furthermore, aptamers can be tailored and functionalized on exosomes to enable targeted therapeutics. Herein, this review emphasizes the empowering of exosomes by aptamers for precision theranostics. A brief introduction of exosomes and aptamers is provided, followed by a discussion of recent progress in aptamer-based exosome detection for disease diagnosis, and the emerging applications of aptamer-functionalized exosomes for targeted therapeutics. Finally, current challenges and opportunities in this research field are presented.

Focused ultrasound enables selective actuation and Newton-level force output of untethered soft robots

Untethered miniature soft robots have significant application potentials in biomedical and industrial fields due to their space accessibility and safe human interaction. However, the lack of selective and forceful actuation is still challenging in revolutionizing and unleashing their versatility. Here, we propose a focused ultrasound-controlled phase transition strategy for achieving millimeter-level spatially selective actuation and Newton-level force of soft robots, which harnesses ultrasound-induced heating to trigger the phase transition inside the robot, enabling powerful actuation through inflation. The millimeter-level spatial resolution empowers single robot to perform multiple tasks according to specific requirements. As a concept-of-demonstration, we designed soft robot for liquid cargo delivery and biopsy robot for tissue acquisition and patching. Additionally, an autonomous control system is integrated with ultrasound imaging to enable automatic acoustic field alignment and control. The proposed method advances the spatiotemporal response capability of untethered miniature soft robots, holding promise for broadening their versatility and adaptability.

Design and Optimization of Geometry of Liquid Feed Conveyor Pipes

The promotion and use of liquid feeding face the challenge of insufficiently stable delivery. This issue can be resolved, in part, by using the spiral flow produced by a spiral pipe (SPP). The aim of this study is to investigate how the structural characteristics of the spiral pipe affect the flow state of the liquid feed, and for this purpose, the computational fluid dynamics (CFD) technique has been employed and the liquid feed delivery process has been simulated by means of an Eulerian two-fluid model The results reveal a significant improvement in the slurry’s homogeneity as it traveled through a spiral pipe compared with a straight pipe (STP). The swirl number normally increased with the number, length, height, and angle of the spiral pipe’s guide vanes. The solid-phase distribution was more homogeneous when values of N = 1, L = 1D, H = 3/8R, and θ = 20° were used, respectively, and the COV within 10D downstream of the outlet of the spiral pipe was 3.902% smaller than that of the straight pipe. The results of this study can be used as a reference for the design of liquid feed-conveying pipes.

Leading Paediatric Infectious Diseases-Current Trends, Gaps, and Future Prospects in Oral Pharmacotherapeutic Interventions.

Paediatric infectious diseases contribute significantly to global health challenges. Conventional therapeutic interventions are not always suitable for children, as they are regularly accompanied with long-standing disadvantages that negatively impact efficacy, thus necessitating the need for effective and child-friendly pharmacotherapeutic interventions. Recent advancements in drug delivery technologies, particularly oral formulations, have shown tremendous progress in enhancing the effectiveness of paediatric medicines. Generally, these delivery methods target, and address challenges associated with palatability, dosing accuracy, stability, bioavailability, patient compliance, and caregiver convenience, which are important factors that can influence successful treatment outcomes in children. Some of the emerging trends include moving away from creating liquid delivery systems to developing oral solid formulations, with the most explored being orodispersible tablets, multiparticulate dosage forms using film-coating technologies, and chewable drug products. Other ongoing innovations include gastro-retentive, 3D-printed, nipple-shield, milk-based, and nanoparticulate (e.g., lipid-, polymeric-based templates) drug delivery systems, possessing the potential to improve therapeutic effectiveness, age appropriateness, pharmacokinetics, and safety profiles as they relate to the paediatric population. This manuscript therefore highlights the evolving landscape of oral pharmacotherapeutic interventions for leading paediatric infectious diseases, crediting the role of innovative drug delivery technologies. By focusing on the current trends, pointing out gaps, and identifying future possibilities, this review aims to contribute towards ongoing efforts directed at improving paediatric health outcomes associated with the management of these infectious ailments through accessible and efficacious drug treatments.

Superwetting Capillary Tubes: Surface Science under Confined Space.

Capillarity is a crucial and pervasive phenomenon in nature and has found important applications in wearable electronics, medical devices, and miniature energy systems. Capillary tubes are the transport vessels in which the surface wettability plays an essential role in efficient and accurate liquid delivery. However, it remains a challenging issue to tailor and measure the surface wettability inside the tubes in view of the confined space. Herein, recent progress on the surface science under confined space is discussed, with a particular focus on surface modification, wettability evaluation, and advanced applications of the superwetting capillary tubes. This Perspective aims to highlight the emerging opportunities in surface science with spatial confinement toward flexible and portable devices.

In silico study of therapeutic deep eutectic solvent for tetracaine liquid delivery

The development of a drug delivery liquid formulation of ester – based tetracaine local anaesthetic is synthesised in silico via the formation of a therapeutic deep eutectic solvent in combination with citral, a natural monoterpenoid. The properties of the obtained liquid system, studied at the nanoscopic level, are derived from a combination of quantum chemistry and classical molecular dynamics simulations. The intermolecular forces (hydrogen bonding) were analysed and their relationship with liquid phase properties were established. Water effect on the liquid phase properties were also considered in terms of competing for hydrogen bonding sites in the components of the developed fluid. The systems proposed in this work were studied using CIT (HBA) 1:1 TET (HBD) molar ratio at temperatures ranging from 288 K to 318 K and 1 bar. The hydrogen bond network developed between the oxygen atom in citral molecules and the –NH group in tetracaine molecules under those conditions, confirmed via minimal cluster analysis, is maintained during the addition of water up to 1.3 wt% as the water molecules do not disrupt the intermolecular hydrogen bond but develop new interactions (hydrogen bonds) with citral and tetracaine monomers presented in the fluid. The reported results probed the suitability of the considered system as an alternative drug delivery method as well as the possibility of developing deep eutectic-based formulation of anaesthetics using natural compounds due to the formation of effective and strong intermolecular hydrogen bonds.

Solid Self-Nanoemulsifying Drug Delivery Systems of Furosemide: In Vivo Proof of Concept for Enhanced Predictable Therapeutic Response.

Liquid self-nano emulsifying drug delivery systems (SNEDDS) of furosemide (FSM) have been explored as a potential solution for enhancing solubility and permeability but are associated with rapid emulsification, spontaneous drug release, and poor in vivo correlation. To overcome the shortcoming, this study aimed to develop liquid and solid self-emulsifying drug delivery systems for FSM, compare formulation dynamics, continue in vivo therapeutic efficacy, and investigate the advantages of solidification. For this purpose, liquid SNEDDS (L-SEDDS-FSM) were formed using oleic acid as an oil, chremophore EL, Tween 80, Tween 20 as a surfactant, and PEG 400 as a co-surfactant containing 53 mg/mL FSM. At the same time, solid SNEDDS (S-SEDDS-FSM) was developed by adsorbing liquid SNEDDS onto microcrystalline cellulose in a 1:1 ratio. Both formulations were evaluated for size, zeta potential, lipase degradation, and drug release. Moreover, in vivo diuretic studies regarding urine volume were carried out in mice to investigate the therapeutic responses of liquid and solid SNEDDS formulations. After dilution, L-SEDDS-FSM showed a mean droplet size of 115 ± 4.5 nm, while S-SEDDS-FSM depicted 116 ± 2.6 nm and zeta potentials of -5.4 ± 0.55 and -6.22 ± 1.2, respectively. S-SEDDS-FSM showed 1.8-fold reduced degradation by lipase enzymes in comparison to L-SEDDS-FSM. S-SEDDS-FSM demonstrated a sustained drug release pattern, releasing 63% of the drug over 180 min, in contrast to L-SEDDS-FSM, exhibiting 90% spontaneous drug release within 30 min. L-SEDDS-FSM exhibited a rapid upsurge in urine output (1550 ± 56 μL) compared to S-SEDDS-FSM, showing gradual urine output (969 ± 29 μL) till the 4th h of the study, providing sustained urine output yet a predictable therapeutic response. The solidification of SNEDDS effectively addresses challenges associated with spontaneous drug release and precipitation observed in liquid SNEDDS, highlighting the potential benefits of solid SNEDDS in improving the therapeutic response of furosemide.

The Impact of Polymers on Enzalutamide Solid Self-Nanoemulsifying Drug Delivery System and Improved Bioavailability.

Enzalutamide (ENZ), marketed under the brand name Xtandi® as a soft capsule, is an androgen receptor signaling inhibitor drug actively used in clinical settings for treating prostate cancer. However, ENZ's low solubility and bioavailability significantly hinder the achievement of optimal therapeutic outcomes. In previous studies, a liquid self-nanoemulsifying drug delivery system (L-SNEDDS) containing ENZ was developed among various solubilization technologies. However, powder formulations that included colloidal silica rapidly formed crystal nuclei in aqueous solutions, leading to a significant decrease in dissolution. Consequently, this study evaluated the efficacy of adding a polymer as a recrystallization inhibitor to a solid SNEDDS (S-SNEDDS) to maintain the drug in a stable, amorphous state in aqueous environments. Polymers were selected based on solubility tests, and the S-SNEDDS formulation was successfully produced via spray drying. The optimized S-SNEDDS formulation demonstrated through X-ray diffraction and differential scanning calorimetry data that it significantly reduced drug crystallinity and enhanced its dissolution rate in simulated gastric and intestinal fluid conditions. In an in vivo study, the bioavailability of orally administered formulations was increased compared to the free drug. Our results highlight the effectiveness of solid-SNEDDS formulations in enhancing the bioavailability of ENZ and outline the potential translational directions for oral drug development.

Formulation, Optimization and Evaluation of Solid SMEDDS of Pioglitazone

This investigation assessed 32 formulations of liquid self-microemulsifying drug delivery system (L-SMEDDS) for pioglitazone (PGZ). The optimal PLS12 formulation comprises 40% capmul MC8 (oil), 40% cremophore RH40 (surfactant), and 20% PEG (co-surfactant). PLS12 exhibited approximately 75 nm droplet size, below 200 nm, and a PDI of 0.47, indicating nanosized droplets with uniform distribution. The formulation demonstrated stability, and achieved supreme drug loading capacity. The enhanced L-SMEDDS was solidified into solidified SMEDDS utilizing Sylloid 244 FP, subsequently in a free-flowing powder without drug interactions. Tablets were successfully formulated by incorporating S-SMEDDS with diverse tableting excipients. The selected tablet batch passed quality control and stability tests. The tablet exhibited a rapid and pH-independent release profile. The combined impact of SMEDDS and tablets collectively enhanced the solubility and dissolution of PGZ hydrochloride

Construction and in vitro/in vivo evaluation of menantine hydrochloride oral liquid sustained-release drug delivery system

Objective The purpose of the present study was to formulate a menantine hydrochloride (MH) sustained-release suspension. Methods Menantine hydrochloride drug resin complex (MH-DRC) was prepared with strong acid cation exchange resin as carrier using water bath method. The MH-DRC was characterized using scanning electron microscopy, X-ray diffraction and infrared spectroscopy. The MH-coated microcapsule (MH-CM) with optimized formulation was further dispersed in a suitable medium to obtain a sustained-release suspension. The rats were given both the MH sustained-release suspension and the commercial MH sustained-release capsule by intragastric administration. The plasma concentration-time curves and related pharmacokinetic parameters were also investigated using a non-atrioventricular model. Results MH and ion-exchange resin were ionically bonded. AmberliteIRP®69 had a higher affinity for MH at the initial concentration of 5 mg·mL−1 and a reaction temperature of 25.0 ± 0.5 °C. In vitro drug release profile showed that both the drug resin complex and the coated microcapsules had a certain level of sustained-release effect. The t1/2 of MH sustained-release suspension was extended from 68.44 h to 72.79 h with the peak blood concentration being decreased to 3.56 μg·mL−1 and the Tmax extended to 12 h compared with the commercial MH sustained-release capsule. The concentration-time curve of the self-made MH sustained-release suspension was flattened and the average relative bioavailability (Fr ) was 116.65% compared with the commercial MH sustained-release capsules. Conclusions The findings showed that the MH sustained-release suspension was successfully formulated with acceptable pharmacokinetic indices for effective treatment of Alzheimer’s disease.

African Breadfruit Seed Oil as Lipid Phase of Self-Emulsifying Drug Delivery System for Improved Gastrointestinal Fluid Solubility of Ibuprofen: Design and Evaluation

Introduction: Rain forest vegetations all over the world produce large quantity of economically important seed oils which, in most developing countries are utilized only as food condiments but hardly employed in pharmaceutical formulations.&#x0D; Objectives: The purpose of this work was to formulate ibuprofen-loaded self-emulsifying drug delivery system for the enhancement of the gastrointestinal fluid solubility of this poorly water soluble drug.&#x0D; Methods: The breadfruit seed oil was extracted by the soxhlet extraction technique and characterized for various physicochemical properties including acid, iodine, peroxide, saponification values and organoleptic properties. The super saturation solubility process, water titration studies and pseudo ternary phase diagrams were used to select and quantify the components of the emulsion systems. The liquid self-emulsifying drug delivery systems were converted to solid forms by adsorption onto a blend of miceocrystalline cellulose and Aerosil-200 powders. The resulting wet mass was dried and processed for encapsulation.&#x0D; Results: The percentage yield of the oil from the extraction process was 20.68 % while the acid, iodine, and saponification values were, 4.12 ± 1.24, 21.91 ± 0.88, and 302.45 ± 1.22 respectively. The ibuprofen exhibited higher solubility in the hydrolysed oil than in the crude form. Fourier transform infrared analysis did not reveal existence of component incompatibility. The optimized liquid and solid emulsions exhibited standard characteristics that were compatible to previous literature reports. The formulations also exhibited superior drug release properties over two control samples.&#x0D; Conclusion: It was concluded that Breadfruit seed oil has the potential to function as the lipid component of ibuprofen-loaded self-emulsifying drug delivery system formulated to enhance the aqueous solubility of the drug.

A highly stable, pressure-driven, flow control system based on Coriolis mass flow sensors for organs-on-chips

Stable delivery of liquids to microfluidic systems is essential for their reproducible functioning, especially when supplying flows to organs-on-chips – delicate living models that recreate human physiology on the microscale and thus can be used to reduce the need for animal testing. Most flow control systems are unable to sustain a robust and stable flow in longer experiments (>1 week), particularly those based on the ubiquitous syringe pump. Though easy to use, syringe pumps have no mechanism for actually measuring flow, let alone flow regulation with sensor feedback. We have developed a liquid delivery system based on the generation of flow by applying a constant air pressure to liquids in sealed containers. A flow of liquid is monitored by accurate measurement of mass flows (mg/min) using downstream Coriolis-based mass flow sensors. Measured mass flows provide fast feedback to integrated valves, with valves opening or closing slightly to increase or decrease solution flows to the organs-on-chips as required. This mass flow sensing principle is not affected by changes in the density, temperature, and viscosity of the liquids being displaced. This is in contrast to systems that use volumetric flow sensors, which require recalibration when these parameters change. The rationale behind using this principle for organs-on-chips, is that the stability provided by this flow control system allows for more control over growth of these mini-organs. We demonstrate the functionality of this system with three examples: 1) Fast stabilization (within seconds) under changing physical conditions; 2) Short-term stability (minutes to hours) of delivered flows in a microreactor with interconnected inlets; and 3) Long-term stability (>1 week) of cell medium flows to a living organ-on-a-chip. Two categories of organs-on-chips (OOCs) can be distinguished: 1) solid OOC are designed for three-dimensional cell or tissue constructs that interact with each other and their surroundings, and 2) barrier-type OOC contain a selective cellular barrier between two compartments as do many barriers in the body. The latter of these two types is the most challenging to culture and maintain as they are very sensitive to variations in flow and pressure surges. The flow control system presented in this work provides a great improvement compared to the use of syringe pumps and volumetric flow sensors in OOC studies. The novelty of this work lies in the long-term stability use of this system for organs-on-chips, maintaining stability for short to very long periods of time without compromising the barrier function of the organ-on-chip by pressure surges, bacterial contamination, or other undesired effects from the flow delivery system.

Liquid Atomization in Rotary Slinger Injectors: Role of Liquid Delivery Manifold

In rotary injectors, the method of liquid delivery can play an important role in the quality of liquid atomization. In slingers, which are employed in small gas turbine engines, the liquid delivery manifold is a key component in the atomizer assembly, which not only delivers the liquid to the atomizer but also acts as a fuel metering device. In the present work, we investigate the liquid atomization in a slinger atomizer with a focus on the effect of the number of liquid delivery ports and port size in the static manifold. Different optical diagnostics are employed to visualize primary liquid breakup and measure droplet size. The results showed that, at a low liquid feed rate, a smaller number of injection ports or port size promotes supercritical breakup (annular liquid exit and disintegration) at an orifice exit such that the breakup length and droplet size are smaller. Also, hole-to-hole variation in the liquid breakup mode is noticed, which refers to different breakup mechanisms in adjacent slinger orifices. On the other hand, Coriolis-induced film breakup is promoted when the liquid feed rate increases. The present study highlights that the design of the delivery manifold can potentially influence spray performance in slinger injectors.

A novel swine model of selective middle meningeal artery catheterization and embolization

BackgroundMiddle meningeal artery (MMA) embolization is a promising intervention as a stand-alone or adjunct treatment to surgery in patients with chronic subdural hematomas. There are currently no large animal models...