Technology for Preventing the Wax Deposit Formation in Gas-Lift Wells at Offshore Oil and Gas Fields in Vietnam

Within the past few decades, the production of high-wax oils at offshore fields in Vietnam has been fraught with severe problems due to the intense formation of asphalt-resin-paraffin deposits (ARPD) in the downhole oil and gas equipment. The formation of organic wax deposits in the tubing string led to a significant decrease in gas-lift wells production, efficiency of compressor units, transport capacity of the piping systems, along with an increase in equipment failure. Subsequently, the efficiency of gas-lift wells dramatically decreased to less than 40% as a whole. The existing methods and technologies for combating organic wax deposit formation in downhole equipment have many advantages. However, their use in producing high-wax anomalous oil does not entirely prevent the wax formation in the tubing string and leads to a significant reduction in oil production, transport capacity, and treatment intervals. The results of theoretical and experimental studies presented in this article demonstrate that a promising approach to improve the efficiency of gas-lift wells during the production of high-wax oil is to use the technology of periodic injection of hot associated petroleum gas (APG) into the annulus of an oil-producing well. The effectiveness of the proposed method of combating wax formation in gas-lift wells highly depends on the combination of a few factors: the determination of wax deposit formation intensity in the well and the implementation of a set of preparatory measures to determine the optimal injection mode of hot APG (flow rate and injection depth) into the annulus between tubing strings and technological pipes. The injection depth of the hot APG should not be less than the depth of wax formation in the tubing string. The optimal injection rate of hot APG is determined by analyzing and mathematically modeling the APG injection system based on well-known thermodynamic laws.

Antigen Uptake After Intradermal Microinjection Depends on Antigen Nature and Formulation, but Not on Injection Depth

The skin is an attractive alternative administration route for allergy vaccination, as the skin is rich in dendritic cells (DCs) and is easily accessible. In the skin multiple subsets of DCs with distinct roles reside at different depths. In this study antigen (=allergen for allergy) formulations were injected in ex vivo human skin in a depth-controlled manner by using a hollow microneedle injection system. Biopsies were harvested at the injection site, which were then cultured for 72 h. Subsequently, the crawled-out cells were collected from the medium and analyzed with flow cytometry. Intradermal administration of ovalbumin (OVA, model antigen) solution at various depths in the skin did not affect the migration and maturation of DCs. OVA was taken up efficiently by the DCs, and this was not affected by the injection depth. In contrast, Bet v 1, the major allergen in birch pollen allergy, was barely taken up by dermal DCs (dDCs). Antigens were more efficiently taken up by CD14+ dDCs than CD1a+ dDCs, which in turn were more efficient at taken up antigen than Langerhans cells. Subsequently, both OVA and Bet v 1 were formulated in cationic and anionic liposomes, which altered antigen uptake drastically following intradermal microinjection. While OVA uptake was reduced by formulation in liposomes, Bet v 1 uptake in dDCs was increased by encapsulation in both cationic and anionic liposomes. This highlights the potential use of liposomes as adjuvant in intradermal allergy vaccine delivery. In conclusion, we observed that antigen uptake after intradermal injection was not affected by injection depth, but varied between different antigens and formulation.

Flow modelling to quantify structural control on CO2 migration and containment, CCS South West Hub, Australia

In order to reduce uncertainties around CO2 containment for the South West Hub CCS site (Western Australia), conceptual fault hydrodynamic models were defined and numerical simulations were carried out. These simulations model worst-case scenarios with a plume reaching a main compartment-bounding fault near the proposed injection depth and at the faulted interface between the primary and secondary containment interval.The conceptual models incorporate host-rock and fault properties accounting for fault-zone lithology, cementation and cataclastic processes but with no account made for geomechanical processes as the risk of reactivation is perceived as low. Flow simulations were performed to assess cross-fault and upfault migration in the case of plume–faults interaction.Results near the injection depth suggest that the main faults are likely to experience a significant reduction in transmissivity and impede CO2 flow. This could promote the migration of CO2 vertically or along the stratigraphic dip.Results near the interface between the primary and secondary containment intervals show that none of the main faults would critically control CO2 flow nor would they act as primary leakage pathways. CO2 flow is predicted to be primarily controlled by the sedimentological morphology. The presence of baffles in the secondary containment interval is expected to be associated with local CO2 accumulations; additional permeability impacts introduced by faults are minor.Thematic collection: This article is part of the Geoscience for CO2 storage collection available at: https://www.lyellcollection.org/cc/geoscience-for-co2-storage

Fine Wrinkle Treatment and Hydration on the Facial Dermis Using HydroToxin Mixture of MicroBotox and MicroHyaluronic Acid

Background Hyaluronic acid (HA) is a key contributor to skin moisture (hydration), and MicroBotox demonstrates improvements for fine wrinkles of the face. Objectives The author sought to evaluate the safety and efficacy of intradermal injection of hydrotoxin (combined mixture of MicroHA and MicroBotox) for the treatment of skin roughness and dryness on facial dermis. Methods Fifty women who had thin, dry skin with fine wrinkles throughout the whole face, especially in the crow’s feet and forehead areas, were enrolled in the study. Two cc stabilized-HA filler and 1 cc (40 U) of botulinumtoxinA were mixed in the novel combined hydrotoxin mixture. Intended to hydrate the dermis and treat fine wrinkles of the face, the mixture was injected into the real dermal layer of the face. The volume of HA per site was 0.002 cc and toxin was 0.04 U. Skin roughness and stratum corneum hydration were measured at 1, 2, 3, and 6 months. Results One month post-treatment, skin roughness was reduced to 50.19% in topographic computer analysis utilizing 10× dermascope photos. Stratum corneum hydration on crow’s feet improved to 81.34% at 1 month and 56.12% at 2 months from pre-treatment baseline (P < 0.0001). Global Aesthetic improvement scale of Skin hydration and fine wrinkle improved. Conclusions The combination injection method of MicroHA and MicroBotox is not associated with side effects and showed significant synergic effect in improvement of skin roughness and moisturizing. Neuramix-hydrotoxin injection method is an easy and reproducible procedure to make constant injection depth and amount. Level of Evidence: 4

Infiltration of nanocarbon suspension into the tracheal cavity during surgical treatment of papillary thyroid carcinoma: a case report

Cervical lymph node metastasis in patients with differentiated thyroid cancer affects postoperative recurrence and survival. Hypoparathyroidism is caused by parathyroid gland injury during thyroidectomy. Carbon nanoparticles can trace stained lymph nodes, aiding in thorough dissection of lymph nodes in the operation area. To reduce postoperative occurrence of hypoparathyroidism, the parathyroid glands and their functions (identified by negative imaging induced by carbon nanoparticles) are retained in situ. However, the safety and adverse effects of nanocarbon suspension in thyroid surgery have rarely been evaluated. In this report, we describe a patient with thyroid cancer who had carbon secretions in the trachea caused by nanocarbon suspension when tracheal intubation was performed under general anesthesia, and the inflatable balloon surface of the tracheal tube was covered with these secretions. The patient recovered without fever, cough, phlegm production, chest pain, hoarseness, or hypocalcemia-induced convulsions. No consensus has yet been reached on the most appropriate injection site, depth, dose, or waiting time for nanocarbons in thyroid cancer surgery. We believe that nanocarbon suspension is safe for use in thyroid cancer surgery, but the most appropriate injection depth should be based on the thickness of the thyroid gland tissue to avoid deep injection into the trachea.

Semi-Analytical Model for Heat and Mass Transfer Evaluation of Vapor Bubbling

Multi-stage refrigeration systems cover a wide range of possibilities and are diffusing more and more. The idea that inspired this work derived from the need to have a tool to model the energy behavior of the intercooler inside a multi-stage refrigeration system. In this work, a semi-analytical model of a single bubble, injected into the liquid of an intercooler of a multi-stage system, has been developed. The developed model is a set of equations derived from the Fourier equation for heat conduction in defined conditions and includes the effects of sensible and latent heat. The vapor bubble is supposed to be injected in the saturated liquid contained in a tank at a defined depth, at an intermediate pressure. The model has been implemented in Matlab and the results show the influence of the liquid surface tension, the injection depth and the thermal diffusivity of the vapor. The model developed here is a useful low-cost tool for evaluating heat transfer optimization of a separator/intercooler of a multi-stage refrigeration system.

Stable Immune Response Induced by Intradermal DNA Vaccination by a Novel Needleless Pyro-Drive Jet Injector

DNA vaccination can be applied to the treatment of various infectious diseases and cancers; however, technical difficulties have hindered the development of an effective delivery method. The efficacy of a DNA vaccine depends on optimal antigen expression by the injected plasmid DNA. The pyro-drive jet injector (PJI) is a novel system that allows for adjustment of injection depth and may, thus, provide a targeted delivery approach for various therapeutic or preventative compounds. Herein, we investigated its potential for use in delivering DNA vaccines. This study evaluated the optimal ignition powder dosage, as well as its delivery effectiveness in both rat and mouse models, while comparing the results of the PJI with that of a needle syringe delivery system. We found that the PJI effectively delivered plasmid DNA to intradermal regions in both rats and mice. Further, it efficiently transfected plasmid DNA directly into the nuclei, resulting in higher protein expression than that achieved via needle syringe injection. Moreover, results from animal ovalbumin (OVA) antigen induction models revealed that animals receiving OVA expression plasmids (pOVA) via PJI exhibited dose-dependent (10 μg, 60 μg, and 120 μg) production of anti-OVA antibodies; while only low titers (< 1/100) of OVA antibodies were detected when 120 μg of pOVA was injected via needle syringe. Thus, PJI is an effective, novel method for delivery of plasmid DNA into epidermal and dermal cells suggesting its promise as a tool for DNA vaccination.