Small Volume Of Liquid Research Articles

Influencing Factors on the Wet Impregnation of Additive‐Manufactured Catalyst Support Structures

AbstractThe wet impregnation of additive manufactured aluminum oxide cylinders with platinum is investigated. The influence of five parameters on the penetration depth and the platinum loading is evaluated. A smaller penetration depth is obtained by increasing pH, sodium chloride concentration in the impregnation solution, decreasing impregnation solution volume, heating rate during subsequent calcination, and no vacuum during prewetting before the impregnation. A pH range of 2 to 4, a low chloride concentration, a small liquid volume, and no vacuum drawing lead to high platinum uptake. This investigation is crucial in understanding and optimizing the wet impregnation process, providing practical guidance for future research with more complex structures.

6486 Gastroparesis Exacerbation by a GLP-1 Agonist

Abstract Disclosure: J.M. Deirmenjian: None. C. Dagher: None. Gastroparesis is characterized by a delay in gastric emptying that may present with nausea, vomiting, satiety, abdominal pain, and anorexia. The most common cause of gastroparesis is diabetes mellitus due to vagal autonomic neuropathy which prevents coordinated gastric contractions. Medications may also induce gastroparesis. Glucagon-like peptide (GLP)- 1 agonists such as semaglutide are being prescribed for diabetes control but also due to benefits of cardiovascular disease and weight loss. Concerns of GLP-1 agonists causing gastroparesis are valid as the mechanism of action includes delaying gastric emptying, especially with newly developed analogs that are more potent with longer half-lives. Patient is a 43-year-old female with a history of hypertension, uncontrolled diabetes mellitus type 2, diabetic gastroparesis, diabetic neuropathy, hyperlipidemia, and obesity who presented with a one-month history of postprandial abdominal pain, nausea, vomiting, and a 40-pound unintentional weight loss with decreased oral intake. Her abdominal pain was sharp and was exacerbated with eating. While she had several gastroparesis flares in the past, she was in remission for almost two years until she was transitioned from dulaglutide to semaglutide after which she had a recurrent flare after two doses. On physical examination, her abdomen was diffusely tender to palpation.On admission, her hemoglobin A1c was 9.7%. She was made NPO, started on peripheral fluids, and initiated on scheduled metoclopramide given high suspicion of a gastroparesis flare. She underwent a gastric emptying study with the gastric amount retained as follows: 97% (at 1 hour), 88% (at 2 hours), and 79% (at 4 hours). Her hospital course was complicated by persistent symptoms of gastroparesis. Gastroenterology recommended scheduled metoclopramide and erythromycin for motility and dietary adjustments including small volume liquid calories. Her oral intake was insufficient and she opted for total peripheral nutrition until symptoms improved. She was advised to never take a GLP-1 agonist again and should her symptoms not improve the next step would be to pursue a gastric pacemaker. The etiology of the patient’s gastroparesis was uncontrolled diabetes. The proximity between starting semaglutide and symptom onset is compelling as an inciting factor in this flare. This admission’s gastric emptying study results showed higher gastric retention for a longer period of time, which may shed light to the potency of these new GLP-1 analogs. The patient tolerated maximum dose dulaglutide for months but not even two doses of semaglutide. With the race to invent more potent GLP-1 agonists for diabetes control and weight loss on the horizon, knowing their side effects and mechanism of action is crucial. While not listed as a contraindication, there should be hesitancy to offer these agents to anyone with significant gastroparesis. Presentation: 6/2/2024

Fundamental study on measurement of soil pH and electrical conductivity in batch tests for the determination of soil-soil solution distribution coefficient

Soil-soil solution distribution coefficient, Kd, is used to understand the mobility of radionuclides in the soil environment. Soil pH and electrical conductivity (EC) are the important factors affecting soil Kd, but existing methods for Kd employed different conditions, as well, standard soil pH and EC methods varied in the test conditions. It would be desirable to measure both pH and EC using the same soil solution for Kd with portable meters (non-glass electrode type) that need only a small liquid volume. In this study, at first, we utilized portable pH and EC meters to examine effects of different conditions on measurements, i.e., the water/soil ratios, contact time and standing time. The results showed that portable meter measurements of soil supernatant after 1 h shaking and 1 h standing could provide comparable pH and EC values with other standard soil tests. Then measurements of pH, and EC up to 168 h were carried out, considering the Kd methods for radiocesium (Cs); only slight differences in these values were observed compared to the standard test method. Considering these results, further analysis was carried out on the correlation between soil Kd-Cs and pH and found a clear decrease of Kd-Cs at pH<5.

Dendrite Growth in Single-Grain and Cyclic-Twinned Sn–3Ag–0.5Cu Solder Joints

The microstructure of electronic solder joints is generated by the solidification of a small volume of bulk undercooled liquid. Here, we study β-Sn dendrite growth in Sn–3Ag–0.5Cu in the specific geometry and nucleation conditions of ball grid array (BGA) solder joints by combining electron backscatter diffraction and imaging of microstructures. It is shown that, while ⟨110⟩\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\langle 110\\rangle$$\\end{document} is the preferred dendrite growth direction, out-of-plane branching and growth with ⟨11W⟩\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\langle 11W\\rangle$$\\end{document} directions are important for allowing dendrites to fan out into the spheroidal volume of BGA joints due to the low symmetry of β-Sn. We find that the crystallographic orientation of β-Sn at the nucleation point plays a strong role in subsequent dendrite growth. In single-grain joints, dendrites are often unfavorably oriented for growth, resulting in different types of zig-zag dendrite growth. In cyclic-twinned joints, it is shown how competitive out-of-plane trunk growth between three dendrite orientations produces {101} boundaries and the characteristic beachball microstructure.

Reconfigurability-Encoded Hierarchical Rectifiers for Versatile 3D Liquid Manipulation.

Manipulating small-volume liquids is crucial in natural processes and industrial applications. However, most liquid manipulation technologies involve complex energy inputs or non-adjustable wetting gradient surfaces. Here, a simple and adjustable 3D liquid manipulation paradigm is reported to control liquid behaviors by coupling liquid-air-solid interfacial energy with programmable magnetic fields. This paradigm centers around a hierarchical rectifier with magnetized microratchets, using Laplace pressure asymmetry to enable multimodal directional steering of various surface tension liquids (23-72 mN m-1). The scale-dependent effect in microratchet design shows its superiority in handling small-volume liquids across three orders of magnitude (100-103 µL). Under programmed magnetic fields, the rectifier can reconfigure its morphology to harness interfacial energy to exhibit richer liquid behaviors without dynamic real-time control. Reconfigured rectifiers show improved rectification performance in the inertia-dominant fluid regime, i.e., a remarkable 2000-fold increase in the critical Weber number for pure ethanol. Moreover, the rectifier's switchable reconfigurations offer flexible control over liquid transport directions and spatiotemporally controllable 3D liquid manipulation reminiscent of inchworm motions. This scalable liquid manipulation paradigm promotes versatile engineering and biochemistry applications, e.g., portable liquid purity testing (screening resolution <1 mN m-1), logical open-channel microfluidics, and automated chemical reactionplatforms.

Optofluidic photonic crystal fiber platform for sensitive and reliable fluorescence based biosensing.

Biosensing plays a pivotal role in various scientific domains, offering significant contributions to medical diagnostics, environmental monitoring, and biotechnology. Fluorescence biosensing relies on the fluorescence emission from labelled biomolecules to enable sensitive and selective identification and quantification of specific biological targets in various samples. Photonic crystal fibers (PCFs) have led to the development of optofluidic fibers enabling efficient light-liquid interaction within small liquid volume. Herein, we present the development of a user-friendly optofluidic-fiber platform with simple hardware requirements for sensitive and reliable fluorescence biosensing with high measurement repeatability. We demonstrate a sensitivity improvement of the fluorescence emission up to 17 times compared to standard cuvette measurement, with a limit of detection of Cy5 fluorophore as low as 100 pM. The improvement in measurement repeatability is exploited for detecting haptoglobin protein, a relevant biomarker to diagnose several diseases, by using commercially available Cy5 labelled antibodies. The study aims to showcase an optofluidic platform leveraging the benefits provided by optofluidic fibers, which encompass easy light injection, robustness, and high sensitivity.

Research on optimization of engineering parameters of effective action distance of multi-stage alternating injection acid etching

This study calibrated the numerical simulation model by using indoor experiments to measure experimental data related to conductivity, acid rock reaction kinetics and acid fluid loss, and combined it with the numerical simulation model to calculate the multi-condition acid flow under multi-physics coupling . The effective action distance of the acid liquid is finally formed, which can be used at 200℃ and 250℃. The effective action distance of the acid liquid is related to the amount of acid liquid and the number of acid liquid injection stages. A set of quick diagrams that can be quickly applied to multi-stage Alternate injection process design and optimized workflow. After calculation, it is concluded that: for the 200℃ formation, it is recommended that the total amount of acid used in the level 3 injection process should be more than 400m3; if level 2 injection is used, taking into account both cost and benefit, the total acid amount of 300m3 can be close to the same amount of acid in level 3 The effective range of the injection. For the 250℃ formation, it is not recommended to use a solution with small liquid volume and multiple stages. If level 3 injection is used, it is recommended that the acid dosage be more than 500m3; if level 2 injection is used, taking into account both benefits and costs, it is recommended to use 400m3 acid liquid . Injection can obtain an effective distance similar to that of level 3 injection with the same amount of acid.

Design of liquid level detection circuit based on sampling probe structure capacitance.

Liquid level detection system is an essential core functional component of automatic clinical medical testing instrument. The conventional liquid level detection method has low detection accuracy and sensitivity, and may have the problem of false detection, which may lead to the inaccurate test results. This paper presents a high sensitivity liquid level detection system based on the principle of variable capacitance. When the sampling probe contacts the liquid level, the probe capacitance will change. The liquid level detection circuit board judges whether the probe contacts the liquid level by sensing the change of probe capacitance. When judging the liquid level signal, the combination of slope detection and amplitude detection is used. The liquid level detection circuit board takes the phase-locked loop(PLL) circuit as the center to detect the change of the capacitance. The reference signal of the PLL is set as a square wave of 375kHz. The double tube probe is used as a part of the tuning capacitor of the voltage controlled oscillator to control the frequency of the output signal, which can realize the rapid phase locking. The experimental results show that the system has accurate detection results, high sensitivity, stable and reliable operation, good dynamic response performance in the case of large and small liquid volume. Compared with other liquid level detection methods based on machine vision, ultrasonic, optics and so on, the proposed liquid level detection system has simpler structure and lower cost, it can avoid the problems of collision, carryover contamination and empty suction by controlling the depth of sampling needle inserted into liquid.

Convective mixing of small volumes of fluids under local heating

The convection under local heating can serve as an effective physical mechanism for mixing small volumes of liquids. We have experimentally demonstrated the mixing of similar liquids using this method. The evolution of the uniformity of the mixture over time was analyzed using a statistical approach. It was found that a small volume of an additive (a few percent of the host layer) can be homogenized in 6-7 minutes.

Smart Pipette: Elevating Laboratory Performance with Tactile Authenticity and Real-Time Feedback.

Mastering the correct use of laboratory equipment is a fundamental skill for undergraduate science students involved in laboratory-based training. However, hands-on laboratory time is often limited, and remote students may struggle as their absence from the physical lab limits their skill development. An air-displacement micropipette was selected for our initial investigation, as accuracy and correct technique are essential in generating reliable assay data. Handling small liquid volumes demands hand dexterity and practice to achieve proficiency. This research assesses the importance of tactile authenticity during training by faithfully replicating the micropipette's key physical and operational characteristics. We developed a custom haptic training approach called 'Smart Pipette' which promotes accurate operation and enhances laboratory dexterity training. A comparative user study with 34 participants evaluated the effectiveness of the Smart Pipette custom haptic device against training with off-the-shelf hardware, specifically the Quest VR hand controller, which was chosen because it is held mid-air similar to a laboratory micropipette. Both training conditions are integrated with the same self-paced virtual simulation displayed on a computer screen, offering clear video instructions and realtime guidance. Results demonstrated that participants trained with the Smart Pipette custom haptic exhibited increased accuracy and precision while making fewer errors than those trained with off-the-shelf hardware. The Smart Pipette and the Quest VR controller had no significant differences in cognitive load and system usability scores. Tactile authentic interaction devices address challenges faced by online learners, while their applicability extends to traditional classrooms, where real-time feedback significantly enhances overall training performance outcomes.

Single-Cell Proteomics Analysis with Tecan Uno and SCREEN Workflow.

With advances in sample preparation, small-volume liquid dispensing technologies, high-resolution MS/MS instrumentation, and data acquisition methodologies, it has become increasingly possible to confidently investigate the heterogeneous proteome found within individual cells. In this chapter, we present an automated high-throughput sample preparation workflow based on the Tecan Uno instrument for quantitative single-cell mass spectrometry-based proteomics. Cells are analyzed by the Single-Cell Proteome Analysis platform (SCREEN), which was introduced earlier and provides deeper proteome coverage across single cells.

Comprehensive Micro-SPE-Based Bottom-Up Proteomic Workflow for Sensitive Analysis of Limited Samples.

Clinical and biological samples are often scarce and precious (e.g., rare cell isolates, microneedle tissue biopsies, small-volume liquid biopsies, and even single cells or organelles). Typical large-scale proteomic methods, where significantly higher protein amounts are analyzed, are not directly transferable to the analysis of limited samples due to their incompatibility with pg-, ng-, and low-μg-level protein sample amounts. Here, we report the on-microsolid-phase extraction tip (OmSET)-based sample preparation workflow for sensitive analysis of limited biological samples to address this challenge. The developed platform was successfully tested for the analysis of 100-10,000 typical mammalian cells and is scalable to allow for lower and larger protein amounts and more samples to be analyzed (i.e., higher throughput of analysis).

Dual magnet solenoid actuator: Practical applications

We demonstrate several practical applications of a novel linear solenoid actuator design previously proposed to create a solenoid micropump which can be used in portable microfluidic systems. The proposed solenoid actuator design is extended to a system that can apply a constant force with a longer stroke and apply a higher force. It also demonstrates effective mini-train operation with easy and simple control, a spring-loaded linear servo system that solves the classic non-linear control problem, and droplet dispensing with accurate and fast control, showing its potential as a compact microfluidic solenoid micropump capable of precisely handling small volumes of liquid. Applications to digital microfluidic and flow-focusing microchannel systems have also been successfully demonstrated. We hope that this study will promote the development of various actuators for microfluidics and contribute to the broader application of microfluidics in more fields.

Viscoelastic rheology of polymer solution probed by resonant thermal capillary fluctuation

We present a measurement of viscoelastic properties of polymer solutions using resonant thermal capillary fluctuations of the surface of a polymer solution droplet. The instantaneous deflection of a cantilever in contact with the drop surface allows for measuring the nanoscale thermal fluctuations of the interface. From the power spectral density of measured fluctuations, we determine the two components of the rheological (dynamic and elastic viscosity) response of the fluid. Our experimental results were compared with rheological measurements using a classical commercial rheometer. We find a good agreement between the two measurements. Our experiments allow to extend the range for dynamical measurements of rheological properties of the solutions up to 20 000 s−1. Furthermore, our method requires only a small volume of liquid (10 μl) to measure the viscosity and is thus suitable for measurements on precious liquids.

Sodium picosulfate in the clinical practice of a surgeon

Picosulfate, a diphenylmethane derivative, belongs to a group of drugs called stimulant laxatives. It is widely used in surgery to treat various colon evacuation disorders due to its effectiveness, safety of use and ease of dosage selection, as well as the option to combine with other laxatives. It is administered much more frequently for colorectal cancer screening, when the colon is prepared using sodium picosulfate combined with other osmotic laxatives, most often polyethylene glycol, which allows to use smaller volumes of solution. According to the literature, this method for cleaning the colon is used most often, which is associated with better adherence of patients to the intake of small volumes of liquid, as shown by our observations. The article highlights the literature data, and the authors also present their own experience – a clinical case report of the treatment of a 30-year-old patient diagnosed with grade I external and internal hemorrhoids. Laser ablation of internal and excision of external hemorrhoids was performed under local anesthesia. Regulax® Picosulfate was included in the therapy in the postoperative period, along with topical and pain relief drugs. As a result, the patient had a comfortable, not very painful bowel movement on the following day after the surgery. The laxative was used to manage stool for a week. In conclusion, the authors draw attention to the fact that increased patient compliance in preparing the colon for examination leads to better cleaning and more informative results during colonoscopy. Therefore, Regulax® Picosulfate combined with other laxatives to prepare a patient for examination, in particular colorectal cancer screening, where it is used most often, applies to a huge number of patients, so the problem of further study of its use is socially significant.

Development of Sustained Release System Based on High Water-Absorbable Gel Formation Using Croscarmellose Sodium, Alkaline Excipients and HPMC (ACSH SR System); Novel Application of Croscarmellose Sodium as a Gel Former.

Croscarmellose sodium, generally used as a superdisintegrant in pharmaceutical formulations, is hydrolyzed to form the gel structure under basic pH conditions. Utilizing this property of croscarmellose sodium, we developed a novel sustained release (SR) system. Immediate release (IR) and SR tablets containing croscarmellose sodium, alkaline excipients and/or hydroxypropyl methylcellulose (HPMC) were prepared and examined for wet strength and in vitro drug release behavior. In vivo oral drug absorption was evaluated for IR tablets, HPMC tablets and our novel SR tablets in fasted Beagle dogs. To form the gel structure even under the physiological condition, alkaline excipients were added into the formulation containing croscarmellose sodium. Furthermore, HPMC was used to make the gel structure strong enough against mechanical destructive forces. The novel alkalized croscarmellose sodium-HPMC (ACSH) SR tablet, consisting of croscarmellose sodium, alkaline excipients, and HPMC, successfully sustained the release of acetaminophen, ibuprofen, or nicardipine hydrochloride, compared with the IR tablets. The ACSH SR system provided a better release of acetaminophen than the HPMC tablet without croscarmellose sodium in the release study using a small volume of liquid, suggesting that substantial release and subsequent absorption would be expected in the distal intestinal segments after oral dosing. The in vivo oral absorption study revealed that the ACSH SR system successfully suppressed and prolonged the plasma concentrations of acetaminophen. This novel ACSH SR system prepared with croscarmellose sodium, alkaline excipients, and HPMC, would be a promising SR formulation for enabling substantial drug absorption in the distal intestinal segments.

Enabling Smart Agriculture through Sensor-Integrated Microfluidic Chip to Monitor Nutrient Uptake in Plants

The soil microenvironment greatly influences a plant’s ability to absorb nutrients and germinate. Sensing these changes in soil medium is critical to understand plant nutrient requirements. Soil being dynamic represents changes in nutrient content, element mobility, texture, water-holding capacity, and microbiota which affects the nutrient levels. These minor changes affect the plant in early growth and development and studying these changes has always been challenging. Microfluidics provides a platform to study nutrient availability and exchange in small volumes of liquid or media resembling plant microenvironments. Here, we have developed a novel microfluidic chip-embedded molecular imprinted sensor for sensing nitrate and phosphate in the media. For data acquisition and recording we have implemented a potentiostat controlled via a microcontroller allowing data storage and transfer via a long-range radio module (LoRA). The microfluidic device’s functionality was validated by germination of the legume crimson red and recoding the nitrate and phosphate levels in media for 7 d. The MIP-based sensor measures nitrate and phosphate, in the range from 1 to 1000 mM. The accuracy of detection for nitrate and phosphate showed 99% and 95% respectively. The chip coupled with MIP based sensor for nutrient analysis serves as a platform technology for studying nitrate and phosphate nutrient exchange and interaction. This chip in the future can be implemented to study plant deficiencies, drought resistance, and plant immunity.

Comparing π-complexation capabilities of ionic liquids containing silver(I) and copper(I) ions by headspace single drop microextraction in combination with high-performance liquid chromatography.

Selective π-complexation capabilities of silver(I) and copper(I) ions can be effectively facilitated in ionic liquids. To understand the effects of environmental factors that influence the π-complexation of these metal ions with analytes, techniques that employ small volumes of ionic liquid that can be readily analyzed are desired. In this study, headspace single drop microextraction coupled with HPLCis used to investigate a diverse set of environmental factors on the metal ion-mediated complexation with aromatic compounds in ionic liquid media. Silver(I) and copper(I) bis[(trifluoromethyl)sulfonyl]imide salts were both studied by dissolving them in the 1-decyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ionic liquid and employing the mixture as extraction media for aromatic compounds. Water and acetonitrile within the sample solution were observed to interfere with the complexation of silver(I) ions and aromatic compounds, while ethylene glycol and triethylene glycol did not. The temperature and extraction times were optimized to fully facilitate the π-complexation capabilities of metal ions in ionic liquid media. Partition coefficients between the sample headspace and metal ion were determined using a three-phase equilibria model. Although no discernable difference in analyte partitioning between the headspace and ionic liquid solvent was observed, analyte partition coefficients to silver(I) ion tended to be greater compared to copper(I) ion.

Accuracy of drawing up liquid medications by veterinary anaesthetists and nurses

ObjectiveTo evaluate the accuracy with which veterinary anaesthetists and nurses of different experience draw up small volumes of liquid. Study designProspective blinded randomized study. MethodsA group of seven European College of Veterinary Anaesthesia and Analgesia (ECVAA) diplomates, six ECVAA residents and six anaesthesia nurses participated in the study. For each participant, five target volumes between 0.01 and 1.0 mL were randomly allocated. They were drawn up 20 times in random order using a 1 mL syringe attached to a 23 gauge needle. A total of 1900 measurements were analysed. An investigator filled the syringe and needle dead space with water for injection before each experiment. The change in mass of the syringe once filled to the target volume was used to calculate the actual volume of liquid drawn up. ResultsLarge errors were made with measurements < 0.04 mL, so they were excluded from the statistical analysis. There was a significant effect of the target volume (p < 0.001) and of the order (p < 0.01). For each mL increase in the target volume, the absolute error decreased by 4% and from the first to the hundredth withdrawal each participant’s absolute error decreased by 1%. The target volume was underestimated in 52.3% of measurements, 42% were overestimated and 5.7% were on target. None of the between-subject predictor variables approached significance. Conclusions and clinical relevanceAccuracy of veterinary anaesthetists and nurses in drawing up medications decreases as the target volume becomes smaller. Small veterinary patients receive small volumes of anaesthetic drugs with higher risks of overdosing compared with larger dogs. Years of experience and staff grade are not associated with greater accuracy. Large percentage errors may be seen with target volumes less than 0.04 mL. Dilutions are recommended for volumes > 0.19 mL in 1 mL syringe.

Stratified tissue biofabrication by rotational internal flow layer engineering

The bioassembly of layered tissue that closely mimics human histology presents challenges for tissue engineering. Existing bioprinting technologies lack the resolution and cell densities necessary to form the microscale cell-width layers commonly observed in stratified tissue, particularly when using low-viscosity hydrogels, such as collagen. Here we present rotational internal flow layer engineering (RIFLE), a novel, low-cost biofabrication technology for assembling tuneable, multi-layered tissue-like structures. Using high-speed rotating tubular moulds, small volumes of cell-laden liquids added to the inner surface were transitioned into thin layers and gelled, progressively building macroscale tubes composed of discrete microscale strata with thicknesses a function of rotational speed. Cell encapsulation enabled the patterning of high-density layers (108 cells ml−1) into heterogenous constructs. RIFLE versatility was demonstrated through tunica media assembly, encapsulating human smooth muscle cells in cell-width (12.5 µm) collagen layers. Such deposition of discrete microscale layers, facilitates the biofabrication of composite structures mimicking the nature of native stratified tissue. This enabling technology has the potential to allow researchers to economically create a range of representative layered tissue.