Differences and Correlations of Morphological and Hemodynamic Parameters between Anterior Circulation Bifurcation and Side-wall Aneurysms.

OBJECTIVE: The objective of this research was to explore the difference and correlation of the morphological and hemodynamic features between sidewall and bifurcation aneurysms in anterior circulation arteries, utilizing computational fluid dynamics as a tool for analysis. METHODS: In line with the designated inclusion criteria, this study covered 160 aneurysms identified in 131 patients who received treatment at Union Hospital of Tongji Medical College, Huazhong University of Science and Technology, China, from January 2021 to September 2022. Utilizing follow-up digital subtraction angiography (DSA) data, these cases were classified into two distinct groups: the sidewall aneurysm group and the bifurcation aneurysm group. Morphological and hemodynamic parameters in the immediate preoperative period were meticulously calculated and examined in both groups using a three-dimensional DSA reconstruction model. RESULTS: No significant differences were found in the morphological or hemodynamic parameters of bifurcation aneurysms at varied locations within the anterior circulation. However, pronounced differences were identified between sidewall and bifurcation aneurysms in terms of morphological parameters such as the diameter of the parent vessel (Dvessel), inflow angle (θF), and size ratio (SR), as well as the hemodynamic parameter of inflow concentration index (ICI) (P<0.001). Notably, only the SR exhibited a significant correlation with multiple hemodynamic parameters (P<0.001), while the ICI was closely related to several morphological parameters (R>0.5, P<0.001). CONCLUSIONS: The significant differences in certain morphological and hemodynamic parameters between sidewall and bifurcation aneurysms emphasize the importance to contemplate variances in threshold values for these parameters when evaluating the risk of rupture in anterior circulation aneurysms. Whether it is a bifurcation or sidewall aneurysm, these disparities should be considered. The morphological parameter SR has the potential to be a valuable clinical tool for promptly distinguishing the distinct rupture risks associated with sidewall and bifurcation aneurysms.

On the yield criterion of porous materials by the homogenization approach and Steigmann-Ogden surface model.

In this work, we investigate the yield criterion of nanoporous materials by using homogenization approach and Steigmann-Ogden surface model. The representative volume element is proposed as an infinite matrix containing a tiny nanovoid. The matrix is incompressible, rigid-perfectly plastic, von Mises materials and nanovoids are dilute and equal in size. First, the constitutive of microscopic stress and microscopic strain rate is established based on the flow criterion. Secondly, according to the Hill's lemma, the relationship between the macroscopic equivalent modulus and the microscopic equivalent modulus is established by homogenization approach. Thirdly, the macroscopic equivalent modulus containing the Steigmann-Ogden surface model including surface parameters, porosity and nanovoid radius is derived from the trial microscopic velocity field. Finally, an implicit macroscopic yield criterion for nanoporous materials is developed. For surface modulus, nanovoids radius and porosity studies are developed through extensive numerical experiments. The research results in this paper have reference significance for the design and manufacture of nanoporous materials.

Virtual simulation with AneuShape™ software for microcatheter shaping in intracranial aneurysm coiling: a validation study.

Background: The shaping of an accurate and stable microcatheter plays a vital role in the successful embolization of intracranial aneurysms. Our study aimed to investigate the application and the role of AneuShape™ software in microcatheter shaping for intracranial aneurysm embolization. Methods: From January 2021 to June 2022, 105 patients with single unruptured intracranial aneurysms were retrospectively analyzed with or without AneuShape™ software to assist in microcatheter shaping. The rates of microcatheter accessibility, accurate positioning, and stability for shaping were analyzed. During the operation, fluoroscopy duration, radiation dose, immediate postoperative angiography, and procedure-related complications were evaluated. Results: Compared to the manual group, aneurysm-coiling procedures involving the AneuShape™ software exhibited superior results. The use of the software resulted in a lower rate of reshaping microcatheters (21.82 vs. 44.00%, p = 0.015) and higher rates of accessibility (81.82 vs. 58.00%, p = 0.008), better positioning (85.45 vs. 64.00%, p = 0.011), and higher stability (83.64 vs. 62.00%, p = 0.012). The software group also required more coils for both small (<7 mm) and large (≥7 mm) aneurysms compared to the manual group (3.50 ± 0.19 vs. 2.78 ± 0.11, p = 0.008 and 8.22 ± 0.36 vs. 6.00 ± 1.00, p = 0.081, respectively). In addition, the software group achieved better complete or approximately complete aneurysm obliteration (87.27 vs. 66.00%, p = 0.010) and had a lower procedure-related complication rate (3.60 vs. 12.00%, p = 0.107). Without this software, the operation had a longer intervention duration (34.31 ± 6.51 vs. 23.87 ± 6.98 min, p < 0.001) and a higher radiation dose (750.50 ± 177.81 vs. 563.53 ± 195.46 mGy, p < 0.001). Conclusions: Software-based microcatheter shaping techniques can assist in the precise shaping of microcatheters, reduce operating time and radiation dose, improve embolization density, and facilitate more stable and efficient intracranial aneurysm embolization.

Hemodynamic Comparison of Treatment Strategies for Intracranial Vertebral Artery Fusiform Aneurysms.

Objective: This study comparatively analyzed the hemodynamic changes resulting from various simulated stent-assisted embolization treatments to explore an optimal treatment strategy for intracranial vertebral artery fusiform aneurysms. An actual vertebral fusiform aneurysm case treated by large coil post-stenting (PLCS) was used as a control. Materials and Methods: A single case of an intracranial vertebral artery fusiform aneurysm underwent a preoperative and eight postoperative finite element treatment simulations: PLCS [single and dual Low-profile Visualized Intraluminal Support (LVIS)], Jailing technique (single and dual LVIS both simulated twice, Pipeline Embolization Device (PED) with or without large coils (LCs). Qualitative and quantitative assessments were performed to analyze the most common hemodynamic risk factors for recurrence. Results: Jailing technique and PED-only had a high residual flow volume (RFV) and wall shear stress (WSS) on the large curvature of the blood flow impingement region. Quantitative analysis determined that PLSC and PED had a lower RFV compared to preoperative than did the jailing technique [PED+LC 2.46% < PLCS 1.2 (dual LVIS) 4.75% < PLCS 1.1 (single LVIS) 6.34% < PED 6.58% < Jailing 2.2 12.45% < Jailing 1.2 12.71% < Jailing 1.1 14.28% < Jailing 2.1 16.44%]. The sac-averaged flow velocity treated by PLCS, PED and PED+LC compared to preoperatively was significantly lower than the jailing technique [PED+LC = PLCS 1.2 (dual LVIS) 17.5% < PLCS 1.1 (single LVIS) = PED 27.5% < Jailing 1.2 = Jailing 2.2 32.5% < Jailing 1.1 37.5% < Jailing 2.1 40%]. The sac-averaged WSS for the PLCS 1.2 (dual LVIS) model was lower than the PED+LC, while the high WSS area of the Jailing 1 model was larger than for Jailing 2 [PLCS 1.2 38.94% (dual LVIS) < PED+LC 41% < PLCS 1.1 43.36% (single LVIS) < PED 45.23% < Jailing 2.1 47.49% < Jailing 2.2 47.79% < Jailing 1.1 48.97% < Jailing 1.2 49.85%]. Conclusions: For fusiform aneurysms, post large coil stenting can provide a uniform coil configuration potentially reducing the hemodynamic risk factors of recurrence. Flow diverters also may reduce the recurrence risk, with long-term follow-up required, especially to monitor branch blood flow to prevent postoperative ischemia.

Influence of Welding Speed on Microstructure and Mechanical Properties of 5251 Aluminum Alloy Joints Fabricated by Self-Reacting Friction Stir Welding.

In the present study, 8 mm-thick 5251 aluminum alloy was self-reacting friction stir welded (SRFSW) employing an optimized friction stir tool to analyze the effect of welding speed from 150 to 450 mm/min on the microstructure and mechanical properties at a constant rotation speed of 400 rpm. The results indicated that high-quality surface finish and defect-free joints were successfully obtained under suitable process parameters. The microhardness distribution profiles on the transverse section of joint exhibited a typical "W" pattern. The lowest hardness values located at the heat-affected zone (HAZ) and the width of the softened region decreased with increasing welding speed. The tensile strength significantly decreased due to the void defect, which showed mixed fracture characteristics induced by the decreasing welding speed. The average tensile strength and elongation achieved by the SRFSW process were 242.61 MPa and 8.3% with optimal welding conditions, and the fracture surface exhibited a typical toughness fracture mode.

YinQiSanHuang Jiedu decoction for the treatment of hepatitis B-related compensated liver cirrhosis: study protocol for a multi-center randomized controlled trial.

INTRODUCTION: Hepatitis B-related compensated liver cirrhosis is related to a higher risk of hepatocellular carcinoma, and antiviral therapy is the preferred method. As the pathological mechanisms of liver fibrosis are complex, drugs developed for a single target are difficult to be effective in clinical practice, so there are no chemical drugs or biological drugs with clear efficacy available for clinical application at present. Traditional Chinese medicine is a kind of medical science that has been gradually formed during thousands of years and continuously enriched by the people of all ethnic groups in China. Traditional Chinese medicine shows curative effects in the treatment of liver diseases, especially in the field of liver fibrosis prevention and treatment. This study aims to test the integrative medicine (Chinese medicine plus antiviral therapy) effective on lowing hepatocellular carcinoma risk among patients with hepatitis-related compensated liver cirrhosis. METHODS AND ANALYSIS: This is a multi-center randomized controlled trial, and a total of 5 hospitals and 802 patients will be involved in. All the subjects are randomly allocated to the YinQiSanHuang Jiedu decoction (YQSHD) group (n = 401) or the placebo group (n = 401). The YQSHD group receives YQSHD granule with entecavir (ETV), and the placebo group receives YQSHD placebo with ETV. The treatment period will last for 52 weeks, and the follow-up period for 52 ± 2 weeks. The primary outcome measure is the annual incidence of HCC. Outcomes will be assessed at baseline and after treatment. The objective of this trial is "the integrative of YQSHD with ETV reduce the annual incidence of HCC to 1%." ETHICS AND DISSEMINATION: The protocol has been approved by the Medical Ethics Committee of Guang'anmen Hospital, China (No.2019-006-KY), and the other centers in the trial will not begin recruiting until the local ethical approval has been obtained. Trial final results will be disseminated via publication. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR1900021532 . Registered on February 26, 2019.

Adsorption of ammonia nitrogen and phenol onto the lignite surface: An experimental and molecular dynamics simulation study.

Ammonia nitrogen and phenol are typical inorganic and organic pollutants in the coal chemical wastewater, respectively. In this study, the adsorption characteristics of ammonia nitrogen and phenol on lignite were investigated through experimental and molecular dynamics simulations. The results show that the adsorption of ammonia nitrogen was carried out via ion exchange, which was significantly faster than the adsorption of phenol driven by the π-π interaction. In the binary adsorption, the surface electronegativity of lignite decreased with the adsorption of ammonia nitrogen thereby promoting the adsorption of phenol. However, the extent of ammonia nitrogen adsorption was slightly reduced in the presence of phenol. Molecular dynamics simulation results indicated that the adsorption of phenol molecules on the lignite surface was closer than that of ammonium ion. The addition of ammonium ions could enhance the adsorption of phenol molecules on the lignite surface. The simulation results were well consistent with the experimental findings. This study indicates lignite has a promising potential in coal chemical wastewater adsorption pretreatment.

Hemodynamic effects of intracranial aneurysms from stent-induced straightening of parent vessels by stent-assisted coiling embolization.

BACKGROUND: Straightening of parent vessels happens for stent-assisted coiling embolization (SACE) treatment of intracranial aneurysms. This study aims to investigate aneurysmal hemodynamic modifications caused by stent-induced vessel straightening. METHODS: Stent and coil deployments of a SACE-treated distal bifurcation aneurysm by finite element method were performed first with the preoperative (not straightened, NS) and postoperative (straightened, S) vessel models respectively. Computational fluid dynamics were then performed for eight models, including (I) NS only model, (II) NS+stent model, (III) NS+coils model, (IV) NS+stent+coils model, (V) S only model, (VI) S+stent model, (VII) S+coils model, and (VIII) S+stent+coils model. Finally, changes in aneurysmal flow velocity, isovelocity surface and wall shear stress (WSS) were analyzed qualitatively and quantitatively. RESULTS: The flow was less in the S models than that in the corresponding NS models. Coils blocked most of the flow into the aneurysm sac in both NS models and S models and vessel straightening had more profound effect on the high aneurysmal flow volume reduction than coiling, while stenting generated adverse effect on flow reduction. Taking the NS only model as baseline (100%), the sac-averaged velocities of models II to VIII were 112%, 36%, 42%, 45%, 39%, 12%, 13%, and high flow volumes were 119%, 21%, 30%, 10%, 8%, 3%, 3%, while the sac-averaged WSSs were 106%, 37%, 44%, 41%, 35%, 17% and 24%, respectively. CONCLUSIONS: Stent-induced vessel straightening combined coil embolization has the best performance in hemodynamic modifications and may reduce the recurrence rate, whereas stenting may generate adverse effect on hemodynamic alterations.

The Effect of Hydrothermal Treatment on Structure and Flotation Characteristics of Lignite and a Mechanistic Analysis.

Lignite is difficult to obtain highly efficient indexes by conventional flotation due to its poor surface hydrophobicity. Although the modification of flotation reagents has made some progress in improving the flotation performance, they all remain at the stage in the laboratory. Here, we proposed to improve the flotation performance by hydrothermal treatment dewatering (HTD) for lignite. Combined with the 13C NMR and FT-IR analysis, the impact of the HTD process on lignite's chemical structural evolution and flotation performance was investigated. The results showed that the HTD process is an effective means for dehydration and deoxygenation to increase lignite quality and the metamorphic degree of coal. The content of oxygen-containing functional groups generally decreases during the HTD process, especially carboxyl acid and ether groups. Therefore, surface properties and wettability of HTD coal samples were changed, and the contact angle gradually increases with the HTD temperature increased, which enhance the hydrophobicity and decrease hydrophilia of the lignite surface. The HTD process effectively improves the flotation performance of lignite during the conventional flotation operation condition, even if the coal pulp after HTD was directly used as a flotation feedstock. Specifically, the coal oil and capryl alcohol were used as collector and forming agents, respectively, and the pulp concentration was adjusted to 60 g/L. The yield of the cleaned coal increased from 12.14% of the raw coal to 55.58% of HTD310, and combustible matter recovery increased from 13.83% of the raw coal to 65.17% of HTD310 by raw coal basis.

Hemodynamic Effect of the Last Finishing Coils in Packing the Aneurysm Neck.

Background: Using the finishing coils to densely pack the aneurysm neck is necessary. However, the exact hemodynamic effect of finishing coils in packing the aneurysm neck is unknown. Objective: To evaluate the hemodynamic characteristics of finishing coils to densely pack the aneurysm neck, using finite element method simulation. Methods: A computational study was performed based on a 44-year-old female patient with an unruptured wide-necked carotid-ophthalmic artery aneurysm treated with low-profile visualized intraluminal support stent-assisted coil embolization. Four computational fluid dynamics models including pre-treatment, post-stenting, common stent-assisted coil embolization (SACE), and common SACE with finishing coils were evaluated qualitatively and quantitatively. Results: Compared with the baseline of pretreatment model (100%), sac-averaged velocity in post-stenting, common SACE, and common SACE with finishing coil models decreased to 95.68%, 24.38%, and 13.20%, respectively; high flow volume (>0.1 m/s) around the aneurysm neck decreased to 92.19%, 9.59%, and 5.57%, respectively; and mean wall shear stress increased or decreased to 107%, 25.94%, and 23.89%, respectively. Conclusion: Finishing coils to densely pack the aneurysm neck can generate favorable hemodynamic modifications, which may decrease the recurrence.

Hemodynamic differences by increasing low profile visualized intraluminal support (LVIS) stent local compaction across intracranial aneurysm orifice.

BACKGROUND: The Low-profile Visualized Intraluminal Support device (LVIS) has been successfully used to treat cerebral aneurysm, and the push-pull technique has been used clinically to compact the stent across aneurysm orifice. Our aim was to exhibit the hemodynamic effect of the compacted LVIS stent. METHODS: Two patient-specific aneurysm models were constructed from three-dimensional angiographic images. The uniform LVIS stent, compacted LVIS and Pipeline Embolization Device (PED) with or without coil embolization were virtually deployed into aneurysm models to perform hemodynamic analysis. Intra-aneurysmal flow parameters were calculated to assess hemodynamic differences among different models. RESULTS: The compacted LVIS had the highest metal coverage across the aneurysm orifice (case 1, 46.37%; case 2, 67.01%). However, the PED achieved the highest pore density (case 1, 19.56 pores/mm2; case 2, 18.07 pores/mm2). The compacted LVIS produced a much higher intra-aneurysmal flow reduction than the uniform LVIS. The PED showed a higher intra-aneurysmal flow reduction than the compacted LVIS in case 1, but the results were comparable in case 2. After stent placement, the intra-aneurysmal flow was further reduced as subsequent coil embolization. The compacted LVIS stent with coils produced a similar reduction in intra-aneurysmal flow to that of the PED. CONCLUSIONS: The combined characteristics of stent metal coverage and pore density should be considered when assessing the flow diversion effects of stents. More intra-aneurysmal flow reductions could be introduced by compacted LVIS stent than the uniform one. Compared with PED, compacted LVIS stent may exhibit a flow-diverting effect comparable to that of the PED.

Efficacy and safety of YinQiSanHuang-antiviral decoction in chronic hepatitis B: study protocol for a randomized, placebo-controlled, double-blinded trial.

INTRODUCTION: Chronic hepatitis B (CHB) is a global public health problem. Antiviral therapy is the primary treatment. Studies have shown that a combined therapy of traditional Chinese medicine (TCM) and conventional antiviral drugs has better efficacy than conventional antiviral for treatment of CHB. YinQiSanHuang-antiviral decoction (YQSH) is a TCM compound preparation that has shown an effect on anti-hepatitis B virus and on slowing progression of hepatitis B-related liver diseases. To evaluate the efficacy and safety of YQSH combined with entecavir and its preventive effect on hepatitis B cirrhosis, we designed this randomized, double-blind and placebo-controlled trial. The objective is that the combination of YinQiSanHuang-antiviral decoction with entecavir will reduce the annual incidence of liver fibrosis/cirrhosis to 1%. METHODS: This is a multicenter, randomized, placebo-controlled, double-blinded trial involving five hospitals. A total of 802 patients are randomly allocated to two groups: the YQSH group (n = 401) or the placebo group (n = 401). The YQSH group receives YQSH with entecavir; the placebo group receives granules of placebo with entecavir. Patients receive treatment for 52 weeks and then are followed up for 52 ± 2 weeks. The primary outcome measure is the annual incidence of cirrhosis. The secondary outcome measures are hepatitis B virus DNA negative rate, hepatitis B surface antigen negative rate, hepatitis B e antigen seroconversion rate, liver function (alanine aminotransferase, aspartate aminotransferase , gamma-glutamyl transferase , alkaline phosphatase , serum albumin, and total bilirubin), spleen thickness, evaluation scores of patients' clinical symptoms, and safety assessment. Outcomes will be assessed at baseline and after treatment. DISCUSSION: Combination therapy could become a trend for treatment of CHB, and this trial expects to provide credible clinical evidence for the future combination of TCM and conventional antiviral drugs for the treatment of CHB. TRIAL REGISTRATION: Chinese Clinical Trial Registry: ChiCTR1900021521. Registered on 25 February 2019.

Are hemodynamics of irregular small carotid-ophthalmic aneurysms different from those of regular ones and large aneurysms based on numerical simulation?

PURPOSE: The purpose of this study is to investigate whether hemodynamics of unruptured, irregular small intracranial aneurysms (SIAs) are different from those of regular ones and large intracranial aneurysms (LIAs) in ophthalmic artery segment of internal carotid artery (ICA). METHODS: Between April 2015 and June 2018, 106 carotid-ophthalmic artery aneurysms were retrospectively analyzed using 3D angiographic images and computational fluid dynamics (CFD). Three categories were stratified: regular SIAs, irregular SIAs and LIAs. Statistical comparisons of the differences in clinical, morphological and hemodynamic parameters among regular SIA, irregular SIA and LIA groups were performed by one-way analysis of variance (ANOVA) or Kruskal-Wallis Test. RESULTS: The median maximal height of regular SIA, irregular SIA and LIA were 3.03 (interquartile range: 2.49-4.22) mm, 4.59 (interquartile range: 3.86-5.32) mm and 11.06 (interquartile range: 9.28-13.69) mm, all P < 0.05). Low shear-stress area percentage (LSA%) and oscillatory shear index (OSI) of irregular SIAs and LIAs were not significantly different (P = 0.72, P = 0.27 respectively), and were significantly higher than those of regular SIAs (all P < 0.01). Wall shear stress (WSS) and normalized wall shear stress (NWSS) of irregular SIAs were significantly higher than those of LIAs (P < 0.01, P < 0.01 respectively), but lower than those of regular SIAs (P < 0.01, P < 0.01 respectively). CONCLUSIONS: Special unruptured irregular SIAs share a similarity of hemodynamic characteristics with LIAs in high LSA% and high OSI, and are different from regular SIAs in hemodynamics.

Differences in hemodynamic characteristics under high packing density between the porous media model and finite element analysis in computational fluid dynamics of intracranial aneurysm virtual treatment.

OBJECTIVE: This study aimed to compare the hemodynamic differences among no sac (NOS), porous media (POM) and finite element analysis (FEA) models to investigate the recurrence-related risks for coiled intracranial aneurysms (IAs). METHODS: The study enrolled 10 patients with 11 IAs who received simple coiling treatment and hemodynamic simulations were performed for all IAs using the above three models. Velocity, wall shear stress (WSS) and residual flow volume (RFV) were calculated and compared in order to assess the model differences for both aneurysm sac and parent vessel regions. RESULTS: For parent artery regions, all three models produced similar flow patterns and quantification analysis did not indicate differences in velocity and WSS (p>0.05). For aneurysm sac regions, the FEA model resulted in higher sac-maximized (0.18 m/s vs 0.06 m/s) and sac-averaged velocity (0.013 m/s vs 0.007 m/s), and higher sac-averaged (0.55 Pa vs 0.36 Pa, p=0.006) and sac-maximized WSS (12.1 Pa vs 6.6 Pa) than the POM model. The differences in RFV between the POM and FEA models under 11 different isovelocity thresholds (0.0001 m/s, 0.001 m/s, 0.002 m/s, 0.005 m/s, 0.01 m/s, 0.02 m/s, 0.05 m/s, 0.1 m/s, 0.2 m/s, 0.5 m/s, and 1 m/s) showed that the POM RFV was generally larger than those of the FEA model. CONCLUSIONS: Compared with the FEA model, the POM model provides a lower velocity and WSS and higher RFV for the aneurysm sac, which could lead to incorrect estimates of the recurrent risk of coiled IAs under high packing density.