Injection Device Research Articles

Structural Aesthetic Treatment With the Hyaluronic Acid Filler VYC-25L: Global Expert Considerations for Safe and Effective Long-Term Outcomes.

VYC-25L is a robust, structural hyaluronic acid (HA) filler designed for facial volumizing, lifting, and contouring. It was first approved in 2019. A group of doctors with various specialties, who have used VYC-25L extensively since it first became available in their countries (3-5 years), share clinical experience and guidance on optimal use. VYC-25L has a unique rheological and physicochemical profile that provides elevated lift capacity and enhanced projection, significant moldability immediately after injection, high levels of tissue integration, reversibility with hyaluronidase, and a long duration of clinical effects-typically lasting at least 24 months. The properties of VYC-25L have created new possibilities for nonsurgical facial medical aesthetics. However, as with any novel product, it is important that injectors recognize how best to use it for the benefit of patients. When first utilizing VYC-25L, it is advisable to start with the chin and jawline to gain familiarity with the gel characteristics before moving into other facial areas, and to consider splitting treatment over two or more sessions. Attention must also be given to injection volume, with less product typically required with VYC-25L compared to other fillers with similar indications. Key principles of good practice should be followed, including appropriate patient selection and pretreatment education, suitable choice of injection device and plane, aseptic technique, slow and careful administration method, and sufficient posttreatment follow-up. By adhering to these principles, VYC-25L can produce natural-looking and highly durable outcomes without substantial safety concerns.

Do-it-yourself flavored capsule cigarettes: Exploiting potential regulatory loopholes?

Capsule cigarettes allow users to crush liquid-filled capsules to release flavors into cigarettes' filters. New devices are emerging across the globe that allow people who smoke to circumvent tobacco flavor restrictions via injectable capsules. This study examined TikTok videos marketing flavored capsule injector devices. TikTok videos (n = 832) posted worldwide between July 6, 2021, and December 28, 2023, that used hashtags #injectorflavor, #flavourclickball, #flavorball, and #injectorballcigarette were collected using a TikTok application programing interface. A codebook was developed using a systematic iterative approach, identifying six codes: flavor capsules, promotes flavors (i.e., fruit, mint or menthol flavors, non-alcoholic drinks, alcoholic drinks), demonstrates how to use or refill large injector devices, demonstrates how to use small convenient devices, includes music (any or English-language). Two independent coders annotated all videos. Overall, 88.3% (n=735) of the videos displayed flavor capsules and had been viewed more than 72 million times. Half (51.6%) of the videos demonstrated how to use large box-shaped devices to inject capsules into the filter of a cigarette, and 15.0% of the videos showed how to do this with smaller, more convenient devices. Flavors including fruit (35.5%), menthol/mint (27.8%), non-alcoholic drinks (21.9%), and alcoholic drinks (11.6%) were used to promote these capsules. Most videos (85.6%) were uploaded by sellers on "TikTok shop." TikTok accounts are promoting injectable capsule devices that circumvent flavored tobacco sales restrictions. Policy makers, tobacco control advocates, and public health practitioners should be aware of such marketing to inform regulation and develop prevention strategies. Our findings identified an emerging product that can encourage circumvention of flavor restriction policies. Regulators, policy makers, public health practitioners, researchers, and advocates should be aware of such products to inform regulation and develop prevention strategies. Given the potential for these products to reduce the intended effects of flavored tobacco sales restrictions, policy makers must be poised to address materials that consumers use to create their own flavored tobacco products, including flavor capsules designed to be inserted into cigarettes.

Clinical assessment of the potential use of a novel single-dose prefilled injection device for the administration of Acthar Gel in children: a narrative review.

Acthar® Gel (repository corticotropin injection; Mallinckrodt Pharmaceuticals, NJ, USA) is indicated for the treatment of myriad inflammatory disorders and is currently administered manually via a vial and syringe. The administration of Acthar via a single-dose prefilled injector (SelfJect™) is intended to simplify its subcutaneous (SC) delivery. The purpose of this review was to determine whether SelfJect is suitable for use in pediatric patients through a literature assessment of various factors, including skin depth, needle length and gauge, dosage, force required for injection, and potential harms. Infants and young children, who commonly have skin-to-muscle distances less than the minimum depth of SelfJect administration, may have risk of unintentional intramuscular (IM) injection; however, an inadvertent IM injection poses no additional risk to children because of the bioequivalence between SC and IM administration of Acthar. The needle gauge of SelfJect is acceptable for pediatric patients and aligns with the Centers for Disease Control and Prevention recommendations for SC injections. The dosage delivered by SelfJect is only appropriate for children over 2years of age. Although adolescents would likely be able to achieve the minimum force required to remove the protective cap and deliver a full dose of Acthar with SelfJect, an adult (18years of age and older) should administer SelfJect to pediatric patients. In addition to the commonly reported postmarketing adverse events (AEs) from Acthar administration (e.g., asthenic conditions, fluid retention, insomnia, headache and increased blood glucose), injection site-related AEs common to injection devices may occur with SelfJect use. The risk of needlestick injury from SelfJect is mitigated by a needle guard. In summary, this review of injection device considerations demonstrates that SelfJect is appropriate for use in the pediatric population.

A Wireless Miniature Injectable Device with Memory-Assisted Backscatter for Multimodal Animal Physiological Monitoring.

This paper introduces a wirelessly powered multimodal animal physiological monitoring application-specific integrated circuit (ASIC). Fabricated in the 180 nm process, the ASIC can be integrated into an injectable device to monitor subcutaneous body temperature, electrocardiography (ECG), and photoplethysmography (PPG). To minimize the device size, the ASIC employs a miniature receiver (Rx) coil for wireless power receiving and data communication through a single inductive link operating at 13.56 MHz. We propose a folded L-shape Rx coil with improved coupling to the transmitter (Tx) coil, even in the presence of misalignment, and enhanced quality factor. The ASIC functions alternatively between recording and sleeping modes, consuming 2.55 μW on average. For PPG measurements, a reflection-type PPG sensor illuminates an LED with tunable current pulses. A current-input analog frontend (AFE) amplifies the current of a photodiode (PD) with 30.8 pARMS current input-referred noise (IRN). The ECG AFE captures ECG signals with a configurable gain of 45-80 dB. The temperature AFE achieves 0.02 ̊C inaccuracy within a sensing range between 27-47 ̊C. The AFE outputs are sequentially digitized by a 10-bit successive approximation register (SAR) analog-to-digital converter (ADC) with an effective number of bits (ENOB) of 8.79. To improve the reliability of data transmission, we propose a memory-assisted backscatter scheme that stores ADC data in an off-chip memory and transmits it when the coupling condition is stable. This scheme achieves a package loss rate (PLR) lower than 0.2% while allowing 24-hour data storage. The device's functionality has been evaluated by in vivo experiments.

12481 Evaluating The Device Handling And Preference Assessment Questionnaire For Growth Hormone Deficiency: Results From Content Validation Interviews

Abstract Disclosure: J. Neergaard: Employee; Self; Novo Nordisk. S. Akhtar: Employee; Self; Novo Nordisk. Stock Owner; Self; Novo Nordisk. B. Berg: Employee; Self; Novo Nordisk. Stock Owner; Self; Novo Nordisk. S. Hamilton: Employee; Self; Novo Nordisk. Stock Owner; Self; Novo Nordisk. E. Hildebrand: Consulting Fee; Self; Novo Nordisk. J. Medina: Employee; Self; Novo Nordisk. Stock Owner; Self; Novo Nordisk. G. Ter-Borch: Employee; Self; Novo Nordisk. Stock Owner; Self; Novo Nordisk. N. Rasmussen: Employee; Self; Novo Nordisk. Stock Owner; Self; Novo Nordisk. Background: Patient experiences with injection devices may affect treatment adherence, and hence it is important to ensure patient-reported outcomes (PRO) instruments used to assess experience are supported by evidence of validity. As part of a study that compared patient preference and ease of use between the devices used to administer Somapacitan (Sogroya®, Novo Nordisk A/S) and Somatrogon (Ngenla®, Pfizer), we assessed relevance, comprehensiveness and comprehension of a PRO instrument, the Device Handling and Preference Assessment Questionnaire (DHPAQ), in adolescent patients with growth hormone deficiency (GHD) and their caregivers. Methods: We recruited 33 adolescent patients with GHD and 37 caregivers across five sites in the US for an open label, randomized, crossover study in which participants simulated an injection with each device using an injection pad or mannequin. The DHPAQ was used to assess patients’ device preference. Two-sided statistical tests with 5% significance levels were performed using DHPAQ responses. After completing the DHPAQ, a random subgroup of 10 adolescents and 10 caregivers were offered additional compensation to participate in a cognitive interview (CI). The CIs were conducted in accordance with the US Food and Drug Administration 2022 Principles for PRO Instruments and 2009 PRO Guidance for Industry. Trained interviewers used a structured guide to evaluate questions, statements, tasks and response options in the DHPAQ. Participants’ interview responses for each question were coded and added to summary tables. These summary tables were evaluated by the study team to determine the relevance, comprehensiveness and participant comprehension of instructions, item stems and response options. Results: When asked if any questions in the DHPAQ did not seem relevant to their device experience, all 20 CI participants answered “no”. Questions on “learning how to use the device”, “selecting the correct dose” and “injecting the dose” were ranked as most relevant. Participants responses from the CIs supported perceived comprehensiveness of all DHPAQ items. All CI participants reported comprehension of all test items in the DHPAQ, and only three items did not receive a “no difficulty” response from all 20 participants. In the main study, the number of participants who preferred the somapacitan device was significantly greater than those who preferred the somatrogon device (84.3% vs 12.9%, p<0.0001). More participants found the somapacitan device easy or very easy to use compared with the somatrogon device (98.6% vs 74.3%). Conclusions: The results from the CIs indicated that the instructions, item stems and response options of the DHPAQ were relevant, comprehensive and fully comprehended by all participants. In the main study, patients with GHD and their caregivers were found to prefer the somapacitan device to the somatrogon device. Presentation: 6/2/2024

12575 Exploring Patient And Parent Perceptions Of Administering Hydrocortisone Injection During Adrenal Crisis: A Cross-Sectional Study

Abstract Disclosure: S.V. Llahana: None. J. Anhony: Employee; Self; Solution Medical LLC. Background: Adrenal insufficiency (AI) necessitates lifelong glucocorticoid replacement therapy for most patients, with parenteral hydrocortisone crucial for managing adrenal crisis, a potentially life-threatening complication. Despite this, approximately 1 in 6-12 patients are hospitalised at least once a year, while 1 in 200 patients die from a potentially preventable adrenal crisis. While timely self-administration of hydrocortisone mitigates these risks, the complexity of current injection devices, requiring up to 20 steps to administer, often impedes effective self-treatment. Evidence shows that although 70% of patients possess emergency hydrocortisone injection kits, only 19% have received training for self-administration. Aim: This study aimed to investigate the experiences and perceptions of patients with AI and their caregivers regarding the usage of Solu-Cortef Act-O-Vial (parenteral hydrocortisone) for adrenal crisis management. Methods: A cross-sectional online survey was conducted, involving participants recruited through USA-based patient advocacy groups, CARES Foundation and Adrenal Insufficiency United. Participants provided insights into factors influencing their ability to manage adrenal crisis using Solu-Cortef Act-O-Vial. Content analysis generated themes, which were quantitatively analyzed using SPSS descriptive statistics and correlations. Results: The survey encompassed 689 patients and caregivers. Content analysis revealed eighteen themes across three domains: patient-based factors, external influences, and emotional aspects. Predominant themes, identified by over 80% of participants, included the complexity of the hydrocortisone device, the necessity for assistance during adrenal crisis episodes, and emotional distress due to fear associated with injection. Conclusion: This study underscores the necessity for a simpler injection device to enhance patient self-confidence and self-administration ability. Heightened awareness among healthcare professionals and the public regarding adrenal crisis is imperative for timely management and prevention of avoidable hospital admissions. Presentation: 6/3/2024

Injectability of high concentrated suspensions using model microparticles

Administration of high-concentrated suspension formulations (i.e., solid particles dispersed in a liquid vehicle) can be limited due to their greater propensity for needle occlusion. The physical interaction between the solid phase (i.e., particles), the vehicle (i.e., flow field), and injection devices could result in the formation of particle bridging or filtering, posing a major risk in dose delivery accuracy and injectability. Here, given the limited understanding on how clogging initiates in syringe and needle delivery systems, we report an experimental approach to fully characterize the transient injection behavior of suspensions. In particular, we first established a custom fluorescence tagging and imaging technique with integrated force sensor to enable visual observation of local particle concentrations and plunger force monitoring throughout injection. Then, we investigated the effects of key formulation properties and device parameters including particle concentration and morphology, carrier viscosity, injection rate, needle and syringe sizes, and tissue backpressure on the incidence of suspension particle jamming and needle clogging. We performed systematic benchmark studies demonstrating that increasing needle inner diameter (ID) and particle density considerably reduced clogging risk, while increasing vehicle viscosity, particle size, and tissue backpressure significantly increased clogging. The experimental framework presented is amenable to quantifying clogging risk in drug-loaded particle suspensions and provides a guideline to make informed decisions on the tradeoffs between creating particles for pharmaceutical impact and feasibility of injection delivery.

Enhancing energy and nitrogen removal efficiency through automatic split injection and innovative aeration device: A study of low C/N ratio environments

A new aeration device based on Bernoulli's principle, Jetventrumixer (JVM), was introduced into an aeration tank in denitrification process, which involved an automatic split injection system (ASIS) into two denitrification tanks every 10 minutes. Real-time monitoring of influent water allowed the calculation of the C/N ratio, enhancing the utilization efficiency of internal carbon sources while reducing the need for external carbon. The comparison of the JVM with the conventional air diffuser for 100 days operation showed that the removal efficiency for NH4+-N in both systems was approximately 98 %, but the nitrification efficiencies were 84 % and 80 %, respectively. This indicates that the JVM achieves an high enough removal efficiency and nitrification efficiency compared with conventional air diffuser system with dramatic reduction in energy consumption by 52.1 %. When the influent wastewater was split and injected into duplicate denitrification tanks at ratios of 3:7, 5:5, and 7:3, the total nitrogen (TN) removal efficiencies were 77 %, 73 %, and 72 %, respectively. In contrast, with the implementation of the ASIS, the TN removal efficiency increased up to 82 %. The increase in TN removal indicates that real-time monitoring could stably track changes chemical composition in wastewater influent over 24 h and introducing ASIS facilitate the efficient utilization of internal carbon sources, thereby enhancing denitrification efficiency and improving TN removal efficiency. Finally, the greenhouse gas (GHG) emissions from the JVM and air diffuser were 9.39401 and 19.60488 tCO2eq year-1, respectively, representing a 52% reduction. Therefore, JVM and ASIS successfully reduced energy consumption and enhanced both nitrification and denitrification efficiencies.

Design and research of the spindle-shaped fish vaccine adsorption injection device

Design and research of the spindle-shaped fish vaccine adsorption injection device

Descripting e + and Weyl fermion as beam/current for pump/injection semiconductor devices

Based on the demand for an improvement in various corpuscle types of current injection, the objective of this technique is to provide a new concept of carrier generators for optoelectronic pump and injection devices. This investigation is conducted to improve current injection by using a particle other than the electron. The idea was conceived from condensed matter physics for a technique to implement positron for carrier transport in semiconductors with the source based on localized emissions. A radioactive source such as 22Na is incident on a tungsten vane moderator, thus having positive electrons flowing and tunneling as well as a laser-driven high-quality positron into semiconductor-based devices. In addition, tantalum arsenide (TaAs) hosting Weyl particles has been discovered to hold significant potential for cutting-edge technological uses. Injection of different carriers and their behavior in semiconductors will lead to the emergence of solid state optoelectronics with different carrier injections that possesses a high energy (100–500 keV) and the possibility of maximum energy that is approximately several tens of megaelectron volts. Significantly, these various carrier sources have a larger range of operational settings and output characteristics due to their various underlying emission principles, thus obtaining a greater kinetic energy for a positron. The transformation to Weyl fermions carries electric charge via a device far more quickly than ordinary electrons, therefore unlocking the potential of new materials with unusual transport properties.

Accuracy of gravity based automatic infusion system applied to chemoport for intravenous infusion.

191 Background: When a vesicant drug is administered to the peripheral vein, a gravity drip method rather than an peristaltic infusion pump is recommended. In addition, it is reported that the gravity based pump has less particle generation than the peristaltic pump that injects fluid through constant peristaltic movement. However, it is pointed out that the disadvantage of gravity based pump is that the rate of administration can easily change according to the change in the location of the injection site. We evaluate the accuracy of new gravity based pump (pressure-sensitive speed control fluid injection device, Accudrip made by Hanvit MD ) at various injection rates and hanging heights common to hospital settings. Methods: The accuracy and safety of the intravenous (IV) flow controller were evaluated for patients receiving IV chemotherapy in the oncology department. It was verified whether the accurate injection rate could be maintained even in various fluid heights, fluid amounts, and types of anticancer drugs that could affect the injection rate. Various anticancer drugs, including immune checkpoint inhibitor, were mixed with 250 ml/500 ml of normal saline and administered for 30 min/60 min, and glucose 500 ml/1000 ml was administered for 60 min/120 min to measure accuracy, each progressed 25 times. Medical staff were surveyed on the ease and limitations of medical practice for each peristaltic infusion pump and new gravity based pump. In addition, side effects occurring in patients during fluid administration were recorded. Results: The mean degree of error in the estimated end time of gravity based automatic infusion system was 3.09% (2.09 ~ 4.10). The error of the gravity based automatic infusion system was statistically significant depending on the patient age (p=.001) and the infusion time (p=.016), but the degree of error according to the type of fluids (p=.302) and fluid concentration (p=.844) was not statistically significant. Among the subjects of the study, nurses' satisfaction with the application of gravity based pump was 4.10 (±0.62) out of 5, and among the general characteristics of nurses, age ( p<.078), and working department (p<.91) did not show a statistically significant difference, but work experience ( p <.021) showed a statistically significant difference. Conclusions: The accuracy of Gravity based automatic infusion system was determined because the degree of error in the expected end time of infusion was not significant according to the infusion variable. In a survey of nurses who have used gravity based pump directly, it was found that the ease of use and satisfaction were similar to those of the conventional peristaltic pump. These findings will contribute greatly to the precise drug administration (over or under-administration) and minimization of adverse events in real-world hospital settings.

Simultaneously performing Taylor dispersion analysis with fluorimetry, photometry, and contactless conductometry at the same detection window

Taylor dispersion analysis (TDA) is a rapid and precise method for determining the hydrodynamic radius (RH) of various substances. We present a versatile TDA system with a flow-through sample injection device, two compact 3-in-1 detectors, and a high-voltage power supply. The 3D-printed detectors combine fluorimetry (FD), photometry (AD@255 nm), and contactless conductometry (C4D) in a single head, enabling simultaneous detection at one capillary window. Using bovine serum albumin (BSA) as a model analyte, we compare TDA with different detection methods. BSA labeled with fluorescein isothiocyanate (FITC) is analyzed in both pulse mode and capillary electrophoresis (CE) TDA. FD and AD detection yield similar RH values, except when FITC binds with small ions in the buffer. In phosphate buffer, C4D underestimates RH values by approximately 18 % due to BSA self-association. In Tris-based buffers, C4D values are 87%–96 % of AD values in pulse mode. With CE-TDA using Tris-CHES buffer, no statistical difference is found across all detections. The system is also applied to CE-TDA of various compounds, particularly charged saccharides. CE-TDA improves the accuracy of TDA results from C4D. We demonstrate the resolution of mixed C4D-TDA signals with assistance from FD and AD signals, successfully resolving gluconate peaks fully covered by another compound. The versatile system with 3-in-1 detection offers a powerful tool for TDA of mixtures and enhances sample throughput.

Development and Characterızatıon of Polylactıc Acıd (Pla)

Today, the usage areas of polymer materials are quite wide. It is not possible to recycle petroleum-based polymers. Synthetic polymers have wide usage areas; This makes synthetic polymers the most important cause of environmental pollution. In particular, disposable products are produced from synthetic polymer materials and then recycled in nature for many years; It has pushed us to seek a solution to this problem. At the same time, decreasing oil resources pose a raw material threat for the production of oil-based products. Therefore, it is aimed to minimize the use of synthetic polymers used in many industries such as automotive, household appliances, food and pharmaceutical packaging, and to contribute to the increase of biopolymer studies. In this study, the production and mechanical characterization of Polylactic Acid, a natural polymer, was performed. PLA, which is a biodegradable polymer as well as a natural polymer, is thought to be an alternative to synthetic polymers in many sectors. Pure natural PLA samples were molded with an injection device and mechanical characterization was performed. The results of tensile and 3-point bending tests were interpreted. As a result of the mechanical tests of PLA, a biocomposite was produced using chestnut shells to improve the mechanical properties and the mechanical properties of this biocomposite were examined. It was concluded that 25% chestnut shell reinforcement improved the mechanical properties of PLA.

Formative and validation human factors studies of a new disposable prefilled injection device for subcutaneous delivery of acthar gel (repository corticotropin injection)

ABSTRACT Background The administration of repository corticotropin injection (Acthar Gel) via a single-dose prefilled injector (SelfJect) is intended to provide a simple, ergonomic alternative to traditional injection. Iterative human factors (HF) studies were conducted to identify potential use deviations and ensure appropriate device use. Research design and methods This article presents seven formative studies, a validation study (with prior pilot validation studies), and a supplemental validation study with participants including lay users, patients, caregivers, and healthcare providers. Participant interactions with SelfJect and the user interface were assessed. Use deviations, user preferences, and participants’ ability to successfully complete tasks were evaluated to generate modifications to the device and user interface. Results In the validation study, 91% of participants successfully administered their first injection. Use errors were rare with simulated-use (6.9%) and knowledge-based (1.6%) testing. Use deviations were commonly attributed to experimental artifact or information oversight, and device warming had the most use errors (49% of participants), even with extensive testing and adjustments to the user interface. Conclusions SelfJect was able to be used in a safe and effective manner by the intended users. Iterative HF studies informed the mitigation of use-related risks to reduce the occurrence of use deviations during simulated use.

Improved assembly DC circuit breaker based on resonant current injection.

DC circuit breakers (DCCBs) with high breaking capacity and low cost are necessary for quick fault clearance in DC networks. The assembly DC circuit breakers (ADCCBs) have a main breaking section (MBS) and a sub-breaking sections (SBS) for each line, which greatly reduce the cost. But in conventional operation, it bears high voltage for a long time when there is a main switch grounding process in any line fault action. To address this problem, a multiport assembly circuit breaker based on current injection (CI-MPACB) is proposed, which is able to generate a resonant current with increasing amplitude by controlling the duty cycle of Integrated Gate-Commutated Thyristors (IGCTs). Then the resonant current is injected into the SBS to generate current zero crossing and arc extinction. A complex frequency domain circuit analysis is performed on the MBS to describe the action logic as well as the commutation characteristics. In addition, the parameters of each component of the MBS are subject to multiple constraints and reasonable design to ensure the fault current could be cut off quickly and reliably. The cost of existing design is greatly reduced due to the design idea of resonant current injection device parameter selection. Finally, a PSCAD/EMTDC simulation confirms the opening viability of CI-MPACB and the accuracy of the parameter design. The test results show that the designed CI-MPACB can cut off DC fault lines.

Effective non-surgical treatment of hemorrhoids with sclerosing foam and novel injection device

ObjectiveTo determine the effectiveness of a novel protocol to treat patients with hemorrhoidal disease. MethodA retrospective study was conducted of consecutive patients treated for hemorrhoidal disease using a patented sclerosing foam and injection device. ResultsThe protocol was applied in 706 patients between May 2013 and May 2023. After a median of one session, pain and anal bleeding were improved/eliminated in 92–94% of cases and fecal incontinence was resolved in both cases. Reduced prolapse sensation was reported in 81%, with prolapse being improved/eliminated in 63%, although folds were not removed in most prolapse cases. No severe side effects were observed, with mild local post-treatment pain in only 7%. The recurrence rate was very low. DiscussionTreatment with this sclerosing microfoam protocol achieved excellent outcomes, improving/eliminating symptoms in almost all patients. It is not recommended for fold removal. Longer-term studies of wider samples are warranted to verify these results.

Quasi-CJ rotating detonation with partially premixed methane-oxygen injection: Numerical simulation and experimental validation

The efficiency gain of rotating detonation depends on several loss factors related to the chamber geometry, the injection principle, the propellants and their mass flow rates, and the equivalence ratio. Numerical simulation can help quantify these losses, and this work presents a Large Eddy Simulation (LES) of rotating detonation in an annular chamber and its validation against experiments. The simulation captured the mixing processes, the overall dynamics of the detonation, the deflagration, and the burnt gas expansion. The injection device was numerically designed to ensure partial premixing of the propellants before injection into the chamber. The chamber had a length of 110 mm, an outer diameter of 80 mm, and a radial width of 10 mm. The mixture consisted of gaseous CH4 and O2 with an equivalence ratio of 1.2 and a mass flow rate of 160 g/s. Combustion kinetics was modeled using a skeletal mechanism with 62 reactions and 16 species. The boundary conditions were adiabatic slip walls. The results reproduce well the detonation velocity (within 1% deviation) and the pressure variation behind the wave. The simulated OH* chemiluminescence compares well with experimental high-speed imaging of the outlet and side of the chamber. The simulation results indicate that 65% of the propellant mass is well mixed in front of the wave whereas 15% of the mixture is burned by deflagration. They show that CH4 and O2 do not axially stratify because they have similar injection dynamics between periodic perturbations induced by the rotating detonation. Good propellant mixing and low deflagration losses explain the high experimental detonation velocity, about 90% of DCJ, and a high combustion efficiency of 98%. These agreements between the computational and experimental results indicate that the simulation is capable of capturing the physical scales relevant to RDC operation and producing reliable results for RDC design.

Modeling drug transport and absorption in subcutaneous injection of monoclonal antibodies: Impact of tissue deformation, devices, and physiology

The pharmaceutical industry has experienced a remarkable increase in the use of subcutaneous injection of monoclonal antibodies (mAbs), attributed mainly to its advantages in reducing healthcare-related costs and enhancing patient compliance. Despite this growth, there is a limited understanding of how tissue mechanics, physiological parameters, and different injection devices and techniques influence the transport and absorption of the drug. In this work, we propose a high-fidelity computational model to study drug transport and absorption during and after subcutaneous injection of mAbs. Our numerical model includes large-deformation mechanics, fluid flow, drug transport, and blood and lymphatic uptake. Through this computational framework, we analyze the tissue material responses, plume dynamics, and drug absorption. We analyze different devices, injection techniques, and physiological parameters such as BMI, flow rate, and injection depth. Finally, we compare our numerical results against the experimental data from the literature.

High-Speed Schlieren Imaging And PIV Of Unsteady Free Jet Injection With Plume Formation

This work aims to investigate Schlieren image correlation velocimetry for flow field quantification of gaseous jet injection in non-manipulable apparatus like flow chambers. Such flow cases often struggle using tracer-based methods: Seeding particles may locally cause technical problems, or the plant design prevents the principal opportunity of tracer adding, both of which lead to a reduced method repertory. This is specifically the case under flow conditions, where contamination of apparatus internals by seeding particles should be avoided completely. Therefore, in this paper, we explore a seedless, refraction-based method to quantify the velocity field of a jet plume. As an experimental flow case, we examine a transient jet release into a closed compartment under nearly atmospheric conditions. For simplification and greater clarity, the laboratory model geometry is kept essentially two-dimensional, thus we chose a flat-jet nozzle as injection device. The experimental investigations cover high-speed Schlieren imaging and laser sheet visualization, followed by digital image correlation. Combining the traditionally qualitative Schlieren approach for flow visualization with Fast Fourier Transform and cross-correlation algorithms, we calculated the velocity vector field of an unsteady jet plume formation. Furthermore, we determined the axial jet velocity profile at steady-state conditions. Our research findings highlight the applicability of Schlieren image correlation velocimetry to quantify gaseous jet formation at encased flow sections spatially. Concluding, the results coincide with data from particle image velocimetry measurements and point out the potential of expanding flow diagnostics to hitherto hardly explored (industrial) flow cases.

Liquid metal complexing Fe3O4 nanoparticles enable rapid polymerization of magnetically conductive hydrogels for various flexible electronics

Hydrogels have recently emerged as promising materials for the next-generation of bioelectronic, due to their similarities to biological tissues, versatility in electrical, mechanical, and bio-functional engineering. This study discoveries that the free radicals produced by co-sonication of Fe3O4 nanoparticles (Fe3O4 NPs) and liquid metal (LM) in aqueous solution can initiate the polymerization of acrylamide to prepare hydrogels. A suspension of LM- Fe3O4 was created and successfully initiated fast polymerization (< 2 min) of acrylamide to form a robust hydrogel with superior conductive properties. The hydrogel has all-encompassing adhesive properties, is highly injectable, and possesses magnetic actuation capabilities. Utilizing the conductive and magnetic properties of hydrogels, a dual control sensor for Morse code transmission was created. Employing the in-situ polymerization properties, a series of flexible electronic devices have been fabricated with hydrogel, including plant leaf electrodes, injectable plant electronic devices and zinc ion batteries. This work presents an unconventional strategy for integrating plants with electronics on the platform of hydrogels, which provides current research ideas in the fields of plant electrophysiology and wearable electronics.