Direct Numerical Simulation and Large Eddy Simulation on a Turbulent Wall-Bounded Flow Using Lattice Boltzmann Method and Multiple GPUs

Direct numerical simulation (DNS) and large eddy simulation (LES) were performed on the wall-bounded flow at Reτ=180 using lattice Boltzmann method (LBM) and multiple GPUs (Graphic Processing Units). In the DNS, 8 K20M GPUs were adopted. The maximum number of meshes is 6.7×107, which results in the nondimensional mesh size of Δ+=1.41 for the whole solution domain. It took 24 hours for GPU-LBM solver to simulate 3×106 LBM steps. The aspect ratio of resolution domain was tested to obtain accurate results for DNS. As a result, both the mean velocity and turbulent variables, such as Reynolds stress and velocity fluctuations, perfectly agree with the results of Kim et al. (1987) when the aspect ratios in streamwise and spanwise directions are 8 and 2, respectively. As for the LES, the local grid refinement technique was tested and then used. Using 1.76×106 grids and Smagorinsky constant (Cs)=0.13, good results were obtained. The ability and validity of LBM on simulating turbulent flow were verified

Native-lung complications following single-lung transplantation for interstitial lung disease: an in-depth analysis

Abstract Background Interstitial lung disease (ILD) represents a heterogeneous group of lung disorders characterized by fibrotic lung tissue changes. In regions with severe donor shortages, single-lung transplantation (SLTx) is often preferred over bilateral lung transplantation for advanced ILD. However, temporal changes and complications in the retained native lung remain poorly understood. Methods A retrospective analysis of 149 recipients who had undergone SLTx was conducted, including 34 ILD SLTx recipients. Native-lung volume, radiological alterations, and perfusion were assessed at distinct post-SLTx time points. Statistical analyses compared ILD and non-ILD SLTx groups. Results Our study revealed a progressive reduction in native-lung volume over time, accompanied by radiographic deterioration and declining perfusion. Complications in the retained native lung were observed, such as pneumothorax (29.4%), pulmonary aspergillosis (11.8%), and acute exacerbation (8.9%). Long-term survival rates were similar between ILD and non-ILD SLTx recipients. Conclusions This study illuminates the unique challenges and complications with respect to the native lung following SLTx for ILD. Ongoing monitoring and tailored management are essential. Despite limitations, this research contributes to our understanding of the temporal progression of native-lung complications post-SLTx for ILD, underscoring the need for further investigation

Systemic-to-pulmonary artery shunt treated with transcatheter arterial embolization and subsequent lung segmentectomy

Abstract Background Systemic-to-pulmonary artery shunt (SPAS) is a rare condition that can occur as a result of congenital heart disease or chronic pulmonary inflammation, occasionally leading to life-threatening hemoptysis. Computed tomography (CT) imaging is crucial in the diagnosis of SPAS, and the optimal management approach for SPAS remains uncertain. This case report presents a novel approach to the treatment of SPAS, consisting of transcatheter arterial embolization of the systemic artery followed by lung segmentectomy. Case presentation A 42-year-old man with abnormal chest findings was referred to us and a diagnosis of SPAS was established based on the CT findings showing a blood flow regurgitation from the dilated left 4th intercostal artery to the Lt. A6. The patient was asymptomatic but we decided to treat him to prevent a risk of future hemoptysis. Transcatheter arterial embolization (TAE) of systemic arteries followed by S6 segmentectomy was successfully performed with minimal blood loss and complete removal of the dilated intra-pulmonary blood vessels. Histological analysis confirmed the diagnosis of SPAS. Conclusion We reported a case of SPAS, who was successfully treated with the combination of TAE and subsequent segmentectomy. The blood loss during surgery was minimal and this strategy appeared to minimize future recanalization and hemoptysis. Further studies and long-term follow-up of SPAS patients are required to establish standardized management guidelines for this rare condition

Additional file 1 of Native-lung complications following single-lung transplantation for interstitial lung disease: an in-depth analysis

Supplementary Material