Development of Pilomatrixoma at the Vaccination Site: A Rare Complication of COVID-19 Vaccination – A Case Report

BACKGROUND Pilomatrixoma, pilomatricoma, or calcifying epithelioma of Malherbe, is a common benign tumor that arises from the base of the hair follicle. Pilomatrixoma has previously been reported at vaccination sites. This report is of a 65-year-old man with an 18-month history of an enlarging pilomatrixoma of the left upper arm at the vaccination site, following a first COVID-19 vaccination. CASE REPORT The case involves a 65-year-old man who developed a left shoulder mass 1.5 years ago. The mass appeared at his COVID-19 vaccine site 3 months after receiving the first dose. The mass measures 3 cm in diameter, was mobile, and exhibited no signs of infection in the physical examination. Surgical excision was performed, and pathology confirmed the mass as a pilomatrixoma, characterized by basaloid cells and keratinization. Three months after surgery, no recurrence was observed. CONCLUSIONS This report has presented an association between vaccination injection sites and pilomatrixoma aligning with previous findings. Enhanced awareness about this condition can substantially improve pilomatrixoma diagnosis accuracy and reduce unnecessary examinations and treatments. Furthermore, we recommend that, along with clinical symptoms, ultrasound imaging be considered a valuable diagnostic tool for pilomatrixoma, with histopathological results to confirm the diagnosis

Online estimation of lithium battery SOC based on fractional order FOUKF‐FOMIUKF algorithm with multiple time scales

Abstract Aiming at the matter of poor precision in predicting the charge of lithium battery by applying conventional integer‐order models and offline parameter identification, this paper proposes a joint fractional‐order multi‐innovations unscented Kalman filter (FOUKF‐FOMIUKF) algorithm for predicting the cells' state of charge (SOC) online and uses the theory of singular‐value decomposition to tackle the issue of failure of the traceless transformation. Initially, the circuitry model of fractional order is built. The parameters of the model are recognized online by fractional‐order unscented Kalman filtering (FOUKF), and the obtained parameters are then transmitted to the method known as the fractional order multi‐innovations unscented Kalman filter (FOMIUKF) to calculate the SOC of the cell. The algorithm was validated under four working conditions such as FUDS (US Federal Urban Driving Distance), BJDST (Beijing Dynamic Stress Test), DST (Dynamic Stress Test), and US06 (Highway Driving Distance Test), respectively, and compared with the FOMIUKF, MIUKF, and FOUKF algorithms for offline identification. The conclusions demonstrate that the SOC estimated by the FOUKF‐FOMIUKF method is controlled within 0.5% of the mean absolute error under the four conditions and the root‐mean‐square error is controlled within 0.8%. It is not difficult to find that the FOUKF‐FOMIUKF algorithm estimates SOC with higher accuracy and robustness

Compressional salt structures of salt-bearing sedimentary basins and its significance to hydrocarbon accumulation

The compressional salt structure is an important type of salt structure formed under the action of regional compressional stress field, which plays an important role in the generation, migration and trap accumulation of oil and gas in sedimentary basins.In the past few decades, important progress has been made in the study of compressional salt structures, which effectively guides the exploration of oil and gas reservoirs in compressional salt sedimentary basins.Based on the physical characteristics of salt rocks, deformation evolution of compressional salt structure and its influence on hydrocarbon accumulation distribution, this paper discusses the deformation evolution characteristics of compressional salt structure, and analyzes the typical salt-bearing fold-and-thrust belt at home and abroad and their hydrocarbon accumulation characteristics.And by comparing the domestic and foreign salt-bearing fold-and-thrust belt and typical oil and gas reservoirs, it summarizes that the domestic and foreign typical salt gypsum layers salt-bearing fold-and-thrust belt are involved in the tectonic deformation, made from the orogenic belt to the basin in the hinterland, tectonic deformation by the strong basement involved in thrust nappe deformation gradually transition to the thin skin decollement fold deformation, and affect the distribution of hydrocarbon accumulation in the fold thrust belts.Finally, the existing problems and future research directions of salt structure in the salt-bearing fold-and-thrust belt in China are analyzed

An experimental study on the CO2/sand dry-frac process

The CO2/sand dry-frac process is a waterless fracturing technology in which CO2 instead of water is used as fracturing fluid. The application of the technology abroad (in the USA and Canada) shows that it works well in stimulating low-pressure, low-permeability, strong water-locking/water sensitive reservoirs. Thus, a series of experimental studies were carried out on its production increase mechanism, fracturing fluid system, pressurized air-tight sand blender, and fracturing process. Some conclusions were made. First, the CO2 viscosity enhancement technology can raise the critical CO2 viscosity by 240–490 times, significantly improving the sand-carrying and fracture-making capacities of CO2 fracturing fluid, so it is a key technique in CO2/sand dry-frac process. Second, with the development of CO2 pressurized air-tight sand blender, a complete set of key devices for the CO2/sand dry-frac process can be made in China, meeting the requirements of the fracturing operation. Third, fully automatic flowback is also realized. Fourth, CO2 instead of water is used in this fracturing operation, saving a large amount of water consumed in fracturing, and lowering cost. Fifth, the CO2/sand dry-frac process is feasible and suitable for the stimulation of low-pressure, low-permeability and strong water-locking reservoirs, with substantial production increase

Influences of sintering temperature on pore morphology, porosity, and mechanical behavior of porous Ti

The purpose of this study was to determine the influences of the sintering temperature on the pore morphology, porosity, and mechanical behavior of titanium foams. Porous Ti samples were successfully manufactured using the metal powder metallurgy method in conjunction with sintering at the four temperatures (900, 1000, 1100, and 1200 °C). The sintering temperature significantly influenced the pore morphology, porosity, and mechanical behavior of the titanium foams. The titanium foams were characterized using an optical microscope in conjunction with scanning electron microscopy. A fracture showed the appearance and growth of a sintering neck between adjacent particles. As the sintering temperature increased, the sintering necks gradually became clearer. The porosity decreased from 56.48% to 46.83% as the sintering temperature increased from 900 °C to 1200 °C, while the initial yield strength of the porous titanium increased from 101.81 to 208.01 MPa. The porous titanium foams produced by the metal powder metallurgy method have a significant utilization potential in hard-tissue engineering