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The article discusses a new suture method called the multi-gradient buried vertical mattress suture, which is used to close high-tension wounds. The method involves three buried vertical mattress sutures and an intradermal suture to reduce tension on wound edges and scar hyperplasia. However, the method does have the drawback of increased skin pigmentation and scarring at puncture points. The article provides a detailed description of the operative procedure and presents a typical case study to demonstrate the effectiveness of the suture method in reducing skin tension and improving aesthetic outcomes. [Extracted from the article]

To explore the influence of different wax components and the shear effect exerted by the pump and pipe wall in the process of crude oil pipeline transportation on the microbehavior of wax aggregation in crude oil at low temperatures, molecular dynamics models of binary and multivariate systems of crude oil with different wax components are established in this paper. The simulation results are compared with the existing experimental results and the NIST database to verify the rationality and accuracy of the models. By using the established binary model to simulate four crude oil systems containing different wax components, it can be found that the longer the wax molecular chain, the more easily the wax molecules aggregate. The influence of temperature on the aggregation process of wax molecules with different chain lengths is also studied. The lower the temperature, the greater the difference in wax molecular aggregation degree caused by the difference in molecular chain length. Nonequilibrium molecular dynamics is used to simulate the shear process of a multivariate system of crude oil, and the micromechanisms of the shear effect on the aggregation process of wax molecules are studied. Shearing can destroy the stable structure of crude oil, resulting in the orientation and conformational transformation of wax molecules, and obtaining the region of wax molecules sensitive to temperature and shear effects, the temperatures of which are below the wax precipitation point and the shear rate of which is lower than the maximum shear rate to prevent the molecular structure from being destroyed. At the same time, the sensitivity of wax components with different chain lengths to the shear effect is studied. The research results provide theoretical guidance for ensuring the safe and economic operation of waxy crude oil production. [ABSTRACT FROM AUTHOR]

Background: Stroke represents the second most prevalent contributor to global mortality. The Chinese Visceral Adiposity Index (CVAI) serves as an established metric for assessing visceral adiposity in the Chinese population, exhibiting prognostic capabilities. This investigation aimed to explore the association of CVAI and new-onset stroke among middle-aged and older Chinese populations. Methods: The study employed data from the 2011 and 2018 China Health and Retirement Longitudinal Study (CHARLS) to assess the association of CVAI and the incidence of new-onset stroke. Utilizing a directed acyclic graph (DAG), 10 potential confounders were identified. Moreover, to explore the association between CVAI and new-onset stroke, three multifactor logistic regression models were constructed, accounting for the identified confounders and mitigating their influence on the findings. Results: The study comprised 7070 participants, among whom 417 (5.9%) experienced new-onset strokes. After controlling for confounding variables, regression analysis suggested that the new-onset stroke's highest risk was linked to the fourth quartile (Q4) of the CVAI, with an odds ratio (OR) of 2.33 and a 95% confidence interval (CI) of 1.67–3.28. The decision tree analysis demonstrated a heightened probability of new-onset stroke among hypertensive individuals with a CVAI equal to or greater than 83, coupled with a C-reactive protein level no less than 1.1 mg/l. Age seemed to have a moderating influence on the CVAI and new-onset stroke association, exhibiting a more prominent interaction effect in participants under 60 years. Conclusions: In middle-aged and older Chinese populations, a linear relationship was discerned between CVAI and the probability of new-onset stroke. CVAI provides a predictive framework for stroke incidence in this demographic, laying the groundwork for more sophisticated risk prediction models that improve the precision and specificity of stroke risk evaluations. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The heat flow coupling characteristics are revealed in the crude oil heating process. • The tank steam coil heating process has been divided into four stages. • The variations of crude oil temperature and flow field heated by different coils have been analyzed. • The heating effect evaluation indexes in the storage tank heating process have set up. Abstract Considering the factors such as ambient temperature, solar radiation, heating steam pressure and physical properties of oil products, a theoretical model for heating process of large floating roof tank coil is established. The numerical solution technology of the crude oil temperature field and flow field is studied to reveal the coupling characteristics of crude oil heat transfer and flow during the storage tank heating process. Furthermore, the influence law of different coil structures on the temperature field and flow field during the crude oil heating process is discussed. On this basis, the evaluation indexes of the heating effect on the crude oil storage tank is set up, which are combined with heating rate and uniform degree of temperature field. The results show that according to variations of crude oil flow field in the tank, the tank steam coil heating process has been divided into four stages including natural convection formation, small vortex formation, large vortex formation and large vortex development. The coil structures have great influence on the temperature field and the flow field of the crude oil tank. The vertical structure and the stereoscopic structure coils will form a certain thickness low temperature zone at the tank bottom during heating process, but the serpentine structure coil will form a heated dead zone at vertex angle and base corner of the tank where area is relatively small. On this basis, comparing the heating effect of the three kinds of coils, it is found that the heating rate of serpentine structure coil is the fastest and more stable. The uniform degree of temperature field is affected by the oil liquid level. Environmental temperature and other factors have little effect and the best heating effect. [ABSTRACT FROM AUTHOR]

Based on the technological requirements related to waxy crude oil pipeline transportation, both unavoidable and avoidable destroyed exergy are defined. Considering the changing characteristics of flow pattern and flow regime over the course of the oil transportation process, a method of dividing station oil pipelines into transportation intervals is suggested according to characteristic temperatures, such as the wax precipitation point and abnormal point. The critical transition temperature and the specific heat capacity of waxy crude oil are calculated, and an unavoidable destroyed exergy formula is derived. Then, taking the Daqing oil pipeline as an example, unavoidable destroyed exergy in various transportation intervals are calculated during the actual processes. Furthermore, the influential rules under various design and operation parameters are further analyzed. The maximum and minimum unavoidable destroyed exergy are 381.128 kJ/s and 30.259 kJ/s. When the design parameters are simulated, and the maximum unavoidable destroyed exergy is 625 kJ/s at the diameter about 250 mm. With the increase of insulation layer thickness, the unavoidable destroyed exergy decreases continuously, and the minimum unavoidable destroyed exergy is 22 kJ/s at 30 mm. And the burial depth has little effect on the unavoidable destroyed exergy. When the operation parameters are simulated, the destroyed exergy increases, but it is less affected by the outlet pressure. The increase amplitude of unavoidable destroyed exergy will not exceed 2% after the throughput rises to 80 m3/h. When the outlet temperature increases until 65 °C, the loss increase range will not exceed 4%. Thus, this study provides a theoretical basis for the safe and economical transportation of waxy crude oil. [ABSTRACT FROM AUTHOR]