The inferior vena cava filter (IVCF) has been used in clinical practice for decades to prevent fatal pulmonary embolism. One of the most commonly used types of IVCFs features a conical umbrella-like design. The geometric similarity among these umbrella-shaped IVCFs suggests a potential commonality in their hemodynamic behavior. However, many previous studies have primarily analyzed the blood flow around a single umbrella-shaped IVCF, failing to capture the general hemodynamic characteristics of this filter type. This paper uses computational fluid dynamics to simulate the blood flow around five typical umbrella-shaped IVCFs, aiming to investigate their hemodynamic commonality. For all five IVCFs, prothrombotic stagnation zones are observed downstream of the filter head, extending nearly 12 times the diameter of the inferior vena cava (IVC). The “viscous block” effect of the filter wires accelerates blood flow within the conical region of the filter, enhancing the potential for clot capture and dissolution. The deployment of umbrella-shaped IVCF remarkably increases the wall shear stress (WSS) on the IVC wall, and the WSS on the filter wire continuously increases in the flow direction. Additionally, the viscous resistance of each umbrella-shaped IVCF contributes several times more to the total flow resistance than the pressure resistance. Our results suggest that alterations in the morphology of the filter wires of umbrella-shaped IVCFs significantly impact the flow resistance of the filter and the WSS distribution pattern of the IVC. These hemodynamic changes may lead to life-threatening conditions, such as IVC lesions, filter rupture, and displacement.
The purpose of this study was to investigate the ability of differential diagnosis of prostate specific antigen decline rate (PSADR) per week, degree of prostatic collapse (DPC) and tissue signal rate of prostate (TSRP) between prostatitis and prostate cancer.The clinical data of 92 patients [prostate specific antigen (PSA) > 10 ng/mL] who underwent prostate biopsy in the Department of Urology, the Second Affiliated Hospital of Xi 'an Jiaotong University from May 2017 to April 2020 were reviewed retrospectively. They were divided into two groups, prostatitis group (n = 42) and prostate cancer (PCa) group (n = 50), according to pathological results. Parameters, like patient characteristics, PSADR, DPC, TSRP and infectious indicators, were compared and analyzed by t test or non-parametric test to identify if there were significant differences. The thresholds of parameters were determined by the receiver operating characteristic curve (ROC), and the data were analyzed to investigate the diagnostic value in distinguishing of prostatitis and prostate cancer.There were statistical differences in age, PSADR, DPC, TSRP, neutrophil percentage in serum, white blood cell (WBC) in urine and prostate volume between prostatitis group and PCa group (P < 0.001, < 0.001, = 0.001, 0.001, 0.024, 0.014, < 0.001 respectively). There was no statistical difference in serum WBC count, serum neutrophil count, monocyte percentage and urine bacterial count between two groups (P = 0.089, 0.087, 0.248, 0.119, respectively). Determined by ROC curve, when the thresholds of PSADR per week as 3.175 ng/mL/week, DPC as 1.113, TSRP as 2.708 were cutoffs of distinguishing prostatitis and prostate cancer. When combining these three indexes to diagnose, the accuracy rate of diagnosis of prostatitis was 78.85%, the accuracy rate of diagnosis of prostate cancer was 97.50%. Univariate analysis suggested that PSADR, DPC and TSRP played an important role in differentiating prostate cancer from prostatitis (P < 0.05), multivariate analysis suggested PSADR > 3.175 might be good indicators when distinguishing prostate disease with prostatitis (OR = 14.305, 95%CI = 3.779 ~ 54.147), while DPC > 1.113 and TSRP > 2.708 might be associated with a higher risk of prostate cancer (OR = 0.151, 95%CI = 0.039 ~ 0.588; OR = 0.012, 95%CI = 0.005 ~ 0.524, respectively).The combination of PSADR per week, DPC, and TSRP might be helpful to distinguish prostate cancer and prostatitis, and can reduce unnecessary invasive and histological procedure.
Abstract The effects of Sedum plumbizincicola intercropped with maize and castor on soil microbial populations and enzyme activities were investigated under field conditions. The quantity of bacteria found under maize/ Sedum plumbizincicola intercrops were significantly reduced by 68.8% when the soil under Sedum plumbizincicola was assessed. The amount of fungi and actinomyces significantly increased by 70.5% and 620.6%, respectively, for Sedum plumbizincicola , while they decreased by 23.2% and 10.7% for maize as compared to counts found in monoculture models. The urease activities of intercropped maize and Sedum plumbizincicola were significantly increased by 63.0% for Sedum plumbizincicola , but no significant change for other intercrop combinations was observed as compared to the enzyme activity of the monoculture. The activities of catalase under maize/ Sedum plumbizincicola intercropping were significantly promoted by 16.7% and 28.8%, respectively, but no significant changes were seen under castor/ Sedum plumbizincicola intercropping. The activities of invertase on sucrose were enhanced significantly with all intercropping patterns as compared to that observed in the monoculture models. Together, this demonstrates that intercropping patterns are important for improving microbial count and enzyme activity in soil.
Introduction Type 2 diabetes mellitus (T2DM) can accelerate cognitive decline and even dementia so that the underlying mechanism deserves further exploration. In the resting state, brain function is still changing dynamically. At present, it is still unknown whether the dynamic functional connectivity (dFC) between various brain regions is in a stable state. It is necessary to interpret brain changes from a new perspective, that is, the stability of brain architecture. Methods In this study, we used a fixed dynamic time scale to explore the stability of dynamic functional architecture in T2DM, then the dynamic effective connectivity (dEC) was used to further explain how information flows through dynamically fluctuating brain architecture in T2DM. Result Two brain regions with decreased stability were found including the right supra-marginal gyrus (SMG) and the right median cingulate gyrus (MCG) in T2DM subjects. The dEC variation has increased between the left inferior frontal gyrus (IFG) and the right MCG. The direction of causal flow is from the right MCG to the left IFG. Conclusion The combination of stability and dEC can not only show the stability of dynamic functional architecture in brain but also reflect the fluidity of brain information, which is an innovative and interesting attempt in the field of neuroimaging. The changes of dynamic architecture in T2DM patients may present an innovative perspective and explanation for their cognitive decline.
Abstract Objective In this study, multimodal magnetic resonance imaging (MRI) imaging was used to deeply analyze the changes of hippocampal subfields perfusion and function in patients with type 2 diabetes mellitus (T2DM), aiming to provide image basis for the diagnosis of hippocampal‐related nerve injury in patients with T2DM. Methods We recruited 35 patients with T2DM and 40 healthy control subjects (HCs). They underwent resting‐state functional MRI (rs‐fMRI), arterial spin labeling (ASL) scans, and a series of cognitive tests. Then, we compared the differences of two groups in the cerebral blood flow (CBF) value, amplitude of low‐frequency fluctuation (ALFF) value, and regional homogeneity (ReHo) value of the bilateral hippocampus subfields. Results The CBF values of cornu ammonis area 1 (CA1), dentate gyrus (DG), and subiculum in the right hippocampus of T2DM group were significantly lower than those of HCs. The ALFF values of left hippocampal CA3, subiculum, and bilateral hippocampus amygdala transition area (HATA) were higher than those of HCs in T2DM group. The ReHo values of CA3, DG, subiculum, and HATA in the left hippocampus of T2DM group were higher than those of HCs. In the T2DM group, HbAc1 and FINS were negatively correlated with imaging characteristics in some hippocampal subregions. Conclusion This study indicates that T2DM patients had decreased perfusion in the CA1, DG, and subiculum of the right hippocampus, and the right hippocampus subiculum was associated with chronic hyperglycemia. Additionally, we observed an increase in spontaneous neural activity within the left hippocampal CA3, subiculum, and bilateral HATA regions, as well as an enhanced local neural coordination in the left hippocampal CA3, DG, HATA, and subiculum among patients with type 2 diabetes, which may reflect an adaptive compensation for cognitive decline. However, this compensation may decline with the exacerbation of metabolic disorders.
Pulmonary embolism (PE), caused by deep venous thrombosis (DVT), is a disease with high morbidity and mortality. Implantation of inferior vena cava filters is an important method for the clinical prevention of PE. The hemodynamic characteristics of filters implanted in the inferior vena cava (IVC) have a significant impact on their performance. However, IVC diameters vary among patients. This may have a direct impact on the hemodynamic properties of the filter. At present, there is no research on this kind of problem to be investigated. In this paper, the hemodynamic properties of the VenaTech convertible filter were simulated in three different IVC models of 15, 20 and 25 mm diameters, using computational fluid dynamics (CFD) as a control variable (only the IVC diameter is varied). The results showed that the diameter has a significant impact on the hemodynamic characteristics after filter implantation. The IVC diameter has a great influence on the stagnation zone of the blood flow, the maximum wall shear stress (WSS) on the upstream side along the filter wire, and the flow resistance. The case of 15 mm diameter was the most prone to thrombus formation downstream of the filter head in the IVC, but the larger WSS on the upstream along the filter wire may facilitate thrombus lysis. Therefore, the change in vessel diameter should be considered when performing filter implantation for patients.
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