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ACS Omega Jun 2023There are few measurements of barium sulfate (BaSO) solubility in water above 373 K available in the literature. BaSO solubility data at water saturation pressure are...
There are few measurements of barium sulfate (BaSO) solubility in water above 373 K available in the literature. BaSO solubility data at water saturation pressure are scare. The pressure dependence on BaSO solubility has not previously been comprehensively reported for the pressure range 100-350 bar. In this work, an experimental apparatus was designed and built to measure BaSO solubility in aqueous solutions under high-pressure (HP), high-temperature (HT) conditions. The solubility of BaSO was experimentally determined in pure water over the temperature range from = (323.1 to 440.1) K and pressures ranging from = (1 to 350) bar. Most of the measurements were done at water saturation pressure: six data points were done above the saturation pressure (323.1-373.1 K) and 10 experiments were conducted at water saturation (373.1-440.1 K). The reliability of the extended UNIQUAC model and results generated in this work was demonstrated by comparing with the scrutinized experimental data reported in the literature. The model gives a very good agreement with BaSO equilibrium solubility data, demonstrating the reliability of the extended UNIQUAC model. The accuracy of the model at high temperature and saturated pressure due to data insufficiencies is discussed.
PubMed: 37332793
DOI: 10.1021/acsomega.3c00647 -
World Journal of Urology Jul 2023The electrohydraulic high-frequency shock wave (Storz Medical, Taegerwilen, Switzerland) is a new way to create small fragments with frequencies up to 100 Hertz (Hz)....
BACKGROUND
The electrohydraulic high-frequency shock wave (Storz Medical, Taegerwilen, Switzerland) is a new way to create small fragments with frequencies up to 100 Hertz (Hz). This study evaluated the efficacy and safety of this method in a stone and porcine model.
MATERIALS AND METHODS
BEGO stones were put in a condom in a specifically designed fixture treated with different modulations to see stone comminution. Standardized ex vivo porcine model with perfused kidneys with 26 upper and lower poles of 15 kidneys was treated with the following modulations: voltage 16-24 kV, capacitor 12 nF and frequency up to 100 Hz. 2000-20,000 shock waves were applied to each pole. The kidneys were perfused with barium sulfate solution (BaSO4) and x-ray was performed to quantify the lesions using pixel volumetry.
RESULTS
There was no correlation between the number of shock waves and the powdering degree or the applied Energy and the grade of pulverization in the stone model. Regarding the perfused kidney model, the number of shock waves, applied voltage and frequency had no direct correlation with the occurrence of parenchymal lesions The detected lesions of the renal parenchyma were minimal, technical parameters had no significant impact and the lesions did not differ from the results of former experiments using 1-1.5 Hz in the same model.
CONCLUSIONS
High-frequency shock wave lithotripsy can produce small stone fragments to pass in a very short time. The injury to the renal parenchyma is comparable to the results of the conventional SWL using 1-1.5 Hz.
Topics: Swine; Animals; Kidney Calculi; Kidney; Lithotripsy; Radiography; Switzerland
PubMed: 37284842
DOI: 10.1007/s00345-023-04441-9 -
Animals : An Open Access Journal From... May 2023In this study, six adult feline cadavers were examined using CTA, 3D printing, and casts injected with epoxy. The aorta, the portal vein, and the gallbladder of 3 feline...
Creation of Three-Dimensional Anatomical Vascular and Biliary Models for the Study of the Feline Liver ( L.): A Comparative CT, Volume Rendering (Vr), Cast and 3D Printing Study.
In this study, six adult feline cadavers were examined using CTA, 3D printing, and casts injected with epoxy. The aorta, the portal vein, and the gallbladder of 3 feline cadavers were separately injected with a 50% mixture of colored vulcanized latex and hydrated barium sulfate as contrast medium to analyze by CT the arterial, venous and biliary systems. The other three cadavers were injected with a mixture of epoxy resin in the aorta, gallbladder and hepatic veins, separately. After the corrosion and washing process, hepatic vascular and biliary casts were obtained. The images obtained by CT showed the vascular and biliary system using a soft tissue window. For the identification of vascular and biliary structures, the 3D prints together with the 3D reconstructions were analyzed, and the results were compared with the casts obtained with epoxy resin. Each of the arterial, venous and biliary branches associated with each of the liver lobes were identified with the help of the printings. In conclusion, the creation of 3D prototypes of nonpathological feline hepatic parenchyma can be used in the veterinary clinic as a basis for the detection of pathological problems in addition to obtaining future pathological hepatic 3D models.
PubMed: 37238006
DOI: 10.3390/ani13101573 -
Materials (Basel, Switzerland) Apr 2023Personnel using X-ray devices, the main source of radiation in medical institutions, are primarily affected by scattered rays. When interventionists use radiation for...
Personnel using X-ray devices, the main source of radiation in medical institutions, are primarily affected by scattered rays. When interventionists use radiation for examinations/treatments, their hands may enter the radiation-generating area. The shielding gloves used for protection against these rays restrict movement and cause discomfort. Here, a shielding cream that directly adheres to the skin was developed and examined as a personal protective device; further, its shielding performance was verified. Bismuth oxide and barium sulfate were selected as shielding materials and comparatively evaluated in terms of thickness, concentration, and energy. With increasing wt% of the shielding material, the protective cream became thicker, resulting in improved protection. Furthermore, the shielding performance improved with increasing mixing temperature. Because the shielding cream is applied to the skin and has a protective effect, it must be stable on the skin and easy to remove. During manufacturing, the bubbles were removed, and the dispersion improved by 5% with increasing stirring speed. During mixing, the temperature increased as the shielding performance increased by 5% in the low-energy region. In terms of the shielding performance, bismuth oxide was superior to barium sulfate by approximately 10%. This study is expected to facilitate the mass production of cream in the future.
PubMed: 37109895
DOI: 10.3390/ma16083059 -
Sensors (Basel, Switzerland) Apr 2023Pulse oximetry is a non-invasive method for measuring blood oxygen saturation. However, its detection scheme heavily relies on single-point measurements. If the oxygen...
Pulse oximetry is a non-invasive method for measuring blood oxygen saturation. However, its detection scheme heavily relies on single-point measurements. If the oxygen saturation is measured at a single location, the measurements are influenced by the profile of illumination, spatial variations in blood flow, and skin pigment. To overcome these issues, imaging systems that measure the distribution of oxygen saturation have been demonstrated. However, previous imaging systems have relied on red and near-infrared illuminations with different profiles, resulting in inconsistent ratios between transmitted red and near-infrared light over space. Such inconsistent ratios can introduce fundamental errors when calculating the spatial distribution of oxygen saturation. In this study, we developed a novel illumination system specifically designed for a pulse oximetry imaging system. For the illumination system, we customized the integrating sphere by coating a mixture of barium sulfate and white paint inside it and by coupling eight red and eight near-infrared LEDs. The illumination system created identical patterns of red and near-infrared illuminations that were spatially uniform. This allowed the ratio between transmitted red and near-infrared light to be consistent over space, enabling the calculation of the spatial distribution of oxygen saturation. We believe our developed pulse oximetry imaging system can be used to obtain spatial information on blood oxygen saturation that provides insight into the oxygenation of the blood contained within the peripheral region of the tissue.
Topics: Oxygen; Lighting; Oximetry; Photic Stimulation; Lung
PubMed: 37050784
DOI: 10.3390/s23073723 -
Polymers Mar 2023In drilling and completion projects, sludge is formed as a byproduct when barite and oil are mixed, and later sticks to the casing. This phenomenon has caused a delay in...
In drilling and completion projects, sludge is formed as a byproduct when barite and oil are mixed, and later sticks to the casing. This phenomenon has caused a delay in drilling progress, and increased exploration and development costs. Since nano-emulsions have low interfacial surface tension, wetting, and reversal capabilities, this study used nano-emulsions with a particle size of about 14 nm to prepare a cleaning fluid system. This system enhances stability through the network structure in the fiber-reinforced system, and prepares a set of nano-cleaning fluids with adjustable density for ultra-deep wells. The effective viscosity of the nano-cleaning fluid reaches 11 mPa·s, and the system is stable for up to 8 h. In addition, this research independently developed an indoor evaluation instrument. Based on on-site parameters, the performance of the nano-cleaning fluid was evaluated from multiple angles by heating to 150 °C and pressurizing to 3.0 Mpa to simulate downhole temperature and pressure. The evaluation results show that the viscosity and shear value of the nano-cleaning fluid system is greatly affected by the fiber content, and the cleaning efficiency is greatly affected by the concentration of the nano-emulsion. Curve fitting shows that the average processing efficiency could reach 60-85% within 25 min and the cleaning efficiency has a linear relationship with time. The cleaning efficiency has a linear relationship with time, where R = 0.98335. The nano-cleaning fluid enables the deconstruction and carrying of the sludge attached to the well wall, which accomplishes the purpose of downhole cleaning.
PubMed: 36987230
DOI: 10.3390/polym15061447 -
Scientific Reports Mar 2023Magnetic resonance imaging and computed tomography (CT) suffer from low contrast sensitivity and potential toxicity of contrast agents. To overcome these limitations, we...
Magnetic resonance imaging and computed tomography (CT) suffer from low contrast sensitivity and potential toxicity of contrast agents. To overcome these limitations, we developed and tested a new class of dual contrast agents based on polydopamine nanoparticles (PDA-NPs) that are functionalized and targeted with hyaluronic acid (HA). These nanoparticles (NPs) are chelated with Gd to provide suitable contrast. The targeted NPs were characterized through ultraviolet-visible spectroscopy (UV-vis), scanning electron microscopy (SEM), infrared Fourier transform (FTIR), and dynamic light scattering (DLS). The cytotoxicity was investigated on HEK293 cells using an MTT assay. The contrast property of synthesized Gd/PDA/HA was compared with Barium sulfate and Dotarem, as commercial contrast agents (CAs) for CT and MRI, respectively. The results illustrated that synthesized PDA-NPs have a spherical morphology and an average diameter of 72 nm. A distinct absorption peak around 280 nm in the UV-vis spectrum reported the self-polymerization of PDA-NPs. The HA coating on PDA-NPs was revealed through a shift in the FTIR peak of C=O from 1618 cm to 1635 cm. The Gd adsorption on PDA/HA-NPs was confirmed using an adsorption isotherm assay. The developed CA showed low in vitro toxicity (up to 158.98 µM), and created a similar contrast in MRI and CT when compared to the commercial agents. The r value for PDA/HA/Gd (6.5 (mg/ml) s) was more than Dotarem (5.6 (mg/ml) s) and the results of the hemolysis test showed that at concentrations of 2, 4, 6, and 10 mg/ml, the hemolysis rate of red blood cells is very low. Additionally, the results demonstrated that PDA/HA/Gd could better target the CD-expressing cancer cells than PDA/Gd. Thus, it can be concluded that lower doses of developed CA are needed to achieve similar contrast of Dotarem, and the developed CA has no safety concerns in terms of hemolysis. The stability of PDA/HA/Gd has also been evaluated by ICP-OES, zeta potential, and DLS during 3 days, and the results suggested that Gd-HA NPs were stable.
Topics: Humans; Contrast Media; Hyaluronic Acid; HEK293 Cells; Hemolysis; Magnetic Resonance Imaging; Nanoparticles; Tomography, X-Ray Computed
PubMed: 36934115
DOI: 10.1038/s41598-023-31252-0 -
Journal of Biomedical Optics Aug 2023X-ray imaging is frequently used for gastrointestinal imaging. Photoacoustic imaging (PAI) of the gastrointestinal tract is an emerging approach that has been...
SIGNIFICANCE
X-ray imaging is frequently used for gastrointestinal imaging. Photoacoustic imaging (PAI) of the gastrointestinal tract is an emerging approach that has been demonstrated for preclinical imaging of small animals. A contrast agent active in both modalities could be useful for imaging applications.
AIM
We aimed to develop a dual-modality contrast agent comprising an admixture of barium sulfate with pigments that absorb light in the second near-infrared region (NIR-II), for preclinical imaging with both x-ray and PAI modalities.
APPROACH
Eleven different NIR-II dyes were evaluated after admixture with a 40% w/v barium sulfate mixture. The resulting NIR-II absorption in the soluble fraction and in the total mixture was characterized. Proof-of-principle imaging studies in mice were carried out.
RESULTS
Pigments that produced more uniform suspensions were assessed further for photoacoustic contrast signal at a wavelength of 1064 nm that corresponds to the output of the Nd:YAG laser used. Phantom imaging studies demonstrated that the pigment-barium sulfate mixture generated imaging contrast in both x-ray and PAI modalities. The optimal pigment selected for further study was a cyanine tetrafluoroborate salt. and whole-body mouse imaging demonstrated that photoacoustic and x-ray contrast signals co-localized in the intestines for both imaging modalities.
CONCLUSION
These data demonstrate that commercially-available NIR-II pigments can simply be admixed with barium sulfate to generate a dual-modality contrast agent appropriate for small animal gastrointestinal imaging.
Topics: Mice; Animals; Barium Sulfate; Contrast Media; X-Rays; Radiography; Spectrum Analysis; Photoacoustic Techniques
PubMed: 36776721
DOI: 10.1117/1.JBO.28.8.082803 -
Polymers Jan 2023The ever-present risk of surgical items being retained represents a real medical peril for the patient and potential liability issues for medical staff. Radiofrequency...
The ever-present risk of surgical items being retained represents a real medical peril for the patient and potential liability issues for medical staff. Radiofrequency scanning technology is a very good means to substantially reduce such accidents. Radiolucent medical-grade polyvinyl chloride (PVC) used for the production of medical items is filled with radiopaque agents to enable X-ray visibility. The present study proves the suitability of bismuth oxychloride (BiOCl) and documents its advantages over the classical radiopaque agent barium sulfate (BaSO). An addition of BiOCl exhibits excellent chemical and physical stability (no leaching, thermo-mechanical properties) and good dispersibility within the PVC matrix. As documented, using half the quantity of BiOCl compared to BaSO will provide a very good result. The conclusions are based on the methods of rotational rheometry, scanning electron microscopy, dynamic mechanical analysis, atomic absorption spectroscopy, and the verification of zero leaching of BiOCl out of a PVC matrix. X-ray images of the studied materials are presented, and an optimal concentration of BiOCl is evaluated.
PubMed: 36771887
DOI: 10.3390/polym15030587