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Objective To investigate the characteristics of pulmonary artery diameter in patients with human immunodeficiency virus (HIV) infection-associated pulmonary hypertension (PAH), and to explore the clinical significance of pulmonary artery diameter correlation indices combined with tumor necrosis factor-α (TNF-α) for early screening and diagnosis of HIV-associated pulmonary hypertension, aiming to provide valuable clinical insights. Methods A retrospective analysis was conducted on 65 HIV-infected patients admitted to the Eighth Hospital Affiliated to Guangzhou Medical University between May 2017 and December 2023. Based on echocardiography findings, the patients were categorized into an observation group (23 cases with PAH) and a control group (42 cases without PAH) . Measurements of pulmonary artery diameter (PA), distal pulmonary artery diameter (dPA), and aortic diameter were obtained in both groups, and the ratio of dPA to aortic diameter (rPA) was calculated. Additionally, serum TNF-α levels were recorded. The clinical significance of each index in early screening and diagnosis of HIV-related pulmonary hypertension was analyzed. Results The PA, dPA, rPA, and TNF- α levels in the observation group were significantly higher compared to those in the control group. Pearson linear correlation analysis revealed a significant positive correlation between TNF-α and both dPA and rPA. Two-column correlation analysis demonstrated a significant association between HIV-PAH and PA, dPA, rPA, as well as TNF-α (P < 0.05). The combined measurement of serum TNF-α with dPA and rPA exhibited an area under the curve (AUC) of 0.891 for diagnosing HIV-APAH, with a sensitivity of 0.870 and specificity of 0.881. Conclusion The combination of pulmonary artery diameter and TNF- α provides a more accurate indication of the presence of HIVPAH, enabling early screening, follow-up, or intervention in high-risk patients. This finding holds significant implications for enhancing patient prognosis. [ABSTRACT FROM AUTHOR]

The Henan Oilfield's medium-permeability blocks face challenges such as high temperatures and severe heterogeneity, making conventional flooding systems less effective. The starch gel system is an efficient approach for deep profile control in high-temperature reservoirs, while the nano-MoS2 system is a promising enhanced oil recovery (EOR) technology for high-temperature low-permeability reservoirs. Combining these two may achieve the dual effects of profile control and oil displacement, significantly enhancing oil recovery in high-temperature heterogeneous reservoirs. The basic performance evaluation of the combination system was carried out under reservoir temperature. Displacement experiments were conducted in target blocks under different permeabilities and extreme disparity core flooding to evaluate the combination system's oil displacement effect. Additionally, the displacement effects and mechanisms of the starch gel and nano-MoS2 combination system in heterogeneous reservoirs were evaluated by simulating interlayer and intralayer heterogeneity models. The results show that the single nano-MoS2 system's efficiency decreases with increased core permeability, and its effectiveness is limited in triple and quintuple disparity parallel experiments. After injecting the starch gel–nano-MoS2 combination system, the enhanced oil recovery effect was significant. The interlayer and intralayer heterogeneous models demonstrated that the primary water flooding mainly affected the high-permeability layers, while the starch gel effectively blocked the dominant channels, forcing the nano-MoS2 oil displacement system towards unswept areas. This coordination significantly enhanced oil displacement, with the combination system improving recovery by 15.33 and 12.20 percentage points, respectively. This research indicates that the starch gel and nano-MoS2 combination flooding technique holds promise for enhancing oil recovery in high-temperature heterogeneous reservoirs of Henan Oilfield, providing foundational support for field applications. [ABSTRACT FROM AUTHOR]

In this paper, a small signal model based on droop controller is established for the self-synchronous voltage source parallel system. The influence of droop coefficient on system stability is analysed, and the constraint conditions of droop coefficient are given. Based on the analysis of the parallel system of self-synchronous voltage source inverter, a multi-machines parallel control scheme of self-synchronous voltage source inverter is formulated. The model and test platform are built to carry out the parallel simulation and experimental verification of distributed line impedance parameters. Simulation and experimental results show that the proposed control strategy can achieve good dynamic and steady-state power sharing.