Use of PETRA-MRA to assess intracranial arterial stenosis: Comparison with TOF-MRA, CTA, and DSA

Background and purposeNon-invasive and accurate assessment of intracranial arterial stenosis (ICAS) is important for the evaluation of intracranial atherosclerotic disease. This study aimed to evaluate the performance of 3D pointwise encoding time reduction magnetic resonance angiography (PETRA-MRA) and compare its performance with that of 3D time-of-flight (TOF) MRA and computed tomography angiography (CTA), using digital subtraction angiography (DSA) as the reference standard in measuring the degree of stenosis and lesion length.Materials and methodsThis single-center, prospective study included a total of 52 patients (mean age 57 ± 11 years, 27 men, 25 women) with 90 intracranial arterial stenoses who underwent PETRA-MRA, TOF-MRA, CTA, and DSA within 1 month. The degree of stenosis and lesion length were measured independently by two radiologists on these four datasets. The degree of stenosis was classified according to DSA measurement. Severe stenosis was defined as a single lesion with >70% diameter stenosis. The smaller artery stenosis referred to the stenosis, which occurred at the anterior cerebral artery, middle cerebral artery, and posterior cerebral artery, except for the first segment of them. The continuous variables were compared using paired t-test or Wilcoxon signed rank test. The intraclass correlation coefficients (ICCs) were used to assess the agreement between MRAs/CTA and DSA as well as inter-reader variabilities. The ICC value >0.80 indicated excellent agreement. The agreement of data was assessed further by Bland–Altman analysis and Spearman's correlation coefficients. When the difference between MRAs/CTA and DSA was statistically significant in the degree of stenosis, the measurement of MRAs/CTA was larger than that of DSA, which referred to the overestimation of MRAs/CTA for the degree of stenosis.ResultsThe four imaging methods exhibited excellent inter-reader agreement [intraclass correlation coefficients (ICCs) > 0.80]. PETRA-MRA was more consistent with DSA than with TOF-MRA and CTA in measuring the degree of stenosis (ICC = 0.94 vs. 0.79 and 0.89) and lesion length (ICC = 0.99 vs. 0.97 and 0.73). PETRA-MRA obtained the highest specificity and positive predictive value (PPV) than TOF-MRA and CTA for detecting stenosis of >50% and stenosis of >75%. TOF-MRA and CTA overestimated considerably the degree of stenosis compared with DSA (63.0% ± 15.8% and 61.0% ± 18.6% vs. 54.0% ± 18.6%, P < 0.01, respectively), whereas PETRA-MRA did not overestimate (P = 0.13). The degree of stenosis acquired on PETRA-MRA was also more consistent with that on DSA than with that on TOF-MRA and CTA in severe stenosis (ICC = 0.78 vs. 0.30 and 0.57) and smaller artery stenosis (ICC = 0.95 vs. 0.70 and 0.80). In anterior artery circulation stenosis, PETRA-MRA also achieved a little bigger ICC than TOF-MRA and CTA in measuring the degree of stenosis (0.93 vs. 0.78 and 0.88). In posterior artery circulation stenosis, PETRA-MRA had a bigger ICC than TOF-MRA (0.94 vs. 0.71) and a comparable ICC to CTA (0.94 vs. 0.91) in measuring the degree of stenosis.ConclusionPETRA-MRA is more accurate than TOF-MRA and CTA for the evaluation of intracranial stenosis and lesion length when using DSA as a reference standard. PETRA-MRA is a promising non-invasive tool for ICAS assessment

Stabilizirane zemljane opeke načinjene od sedimenta rijeke Huang He

This paper presents an experimental study on the microstructure and performance of stabilized earth bricks prepared from the Yellow River sediment. The sediment is modified by inorganic cementitious material, polymer bonding agent, and jute fibre. The results show that the sediment is preliminarily consolidated when the mixture ratio of activated sediment/cementitious binder/sand is 65/25/10. Compressive strength and softening coefficient of stabilized earth bricks is further improved by polymer bonding agent and jute fibre. SEM images and EDS spectral analysis indicate that there is indeed synergy among inorganic hydration products, polymer network and jute fibre to strengthen the sediment.Eksperimentalno su proučena mikrostruktura i svojstva stabilizirane zemljane opeke načinjene od sedimenta rijeke Huang He (Žuta rijeka). Sedimentu su pridodani anorganski cement, polimerno vezivo i jutena vlakna. Prema rezultatima sediment je prethodno konsolidiran kada je u smjesi maseni omjer aktiviranog sedimenta, cementa i pijeska 65 : 25 : 10. Tlačna čvrstoća i koeficijent omekšivanja stabilizirane zemljane opeke dodatno su poboljšani polimernim vezivom i jutenim vlaknima. Snimke SEM-om i analiza EDS-om pokazuju da u očvršćivanju sudjeluju anorganski hidracijski produkt, polimerna mreža i jutena vlakna

Mechanical Properties and Axial Compression Deformation Property of Steel Fiber Reinforced Self-Compacting Concrete Containing High Level Fly Ash

The cement industry has brought serious environmental pollution problems. In the background of ecological civilization, accelerating rational use of waste resources plays an important role in protecting the environment. In this study, self-compacting concrete (SCC) is prepared using fly ash and lime powder as supplementary cementitious materials by replacing 50%, 60%, and 70% of ordinary Portland cement. By systematically analyzing the influence of the fly ash replacement rate on the workability and mechanical properties of SCC, steel-fiber-reinforced SCC containing 60% fly ash is chosen for further study, and steel fiber is added at the percentages of 0.25%, 0.50%, 0.75%, and 1.00%. The performances in fresh and hardened states are investigated in terms of workability, compressive strength, splitting tensile strength, flexural strength, and axial compression deformation property. The obtained outcomes indicate that although the incorporation of fly ash can improve the workability of the mixture, there is a negative correlation between the mechanical properties of SCC and the fly ash replacement rate. For steel-fiber-reinforced SCC containing 60% fly ash, when the content of steel fibers exceeds 0.75%, the workability decreases sharply, and even when the volume fraction is 1.00%, the passing ability cannot meet the requirements of the technical specifications for applications of self-compacting concrete. The analysis results for mechanical properties show that compressive strength is not changed significantly with increasing percentage of steel fibers. The steel fibers strengthen splitting tensile strength and flexural strength significantly, and compared with that of without steel fibers, they increased by 22% and 58%, respectively, with steel fibers up to 1.00%. Additionally, the parameters of the axial compression deformation property are improved by introducing steel fibers, especially the strain energy (Vε) and relative toughness (Γ) of steel-fiber-reinforced SCC containing a high level of fly ash

Fracture properties of steel fibre reinforced high-volume fly ash self-compacting concrete

This paper presents an experimental investigation on the fracture mechanical properties of steel fibre-reinforced high-volume fly ash self-compacting concrete (HFSCC). Specifically, self-compacting concrete (SCC) of various toughness was designed at desired steel fibre volume fractions of 0, 0.25 v%, 0.50 v%, 0.75 v% and 1.00 v% by volume and fly ash contents of 40 wt%, 50 wt%, 60 wt% and 70 wt% by mass. The fracture mechanical properties of HFSCC (cured for one year) were studied by a three-point bending beam test. The influence of fly ash and steel fibre content on fracture parameters was systematically discussed. The research indicated that the fracture mechanical properties of HFSCC with different fly ash percentage were improved by adding steel fibres. The fullness of the force (F)-crack mouth opening displacement (CMOD) curves gradually increased with the steel fibre volume fraction (Vf). The peak load (Fp), peak CMOD (CMODP), fracture toughness (KIC) and fracture energy (GF) of the fracture parameters linearly increased with Vf. Furthermore, the correlation between them was analysed numerically. The slope of the fitting line increased with increasing fly ash content, indicating that high-volume fly ash was more conducive to improving the fracture mechanics of SCC after long-term ageing. After the hydration reaction, residual calcium hydroxide was observed only in the cross-sectional image of HFSCC-70, it helped to improve the fracture mechanical properties of HFSCC

Effect of Different Doses of Vitamin D on the Intestinal Flora of Babies with Eczema: An Experimental Study

Infantile eczema is a common allergic disease caused by a variety of factors, which is often accompanied by immune dysfunction and dysbiosis of the intestinal flora. Vitamin D may affect the composition and function of intestinal flora by regulating the expression of antimicrobial peptides, thereby avoiding intestinal dysbiosis. The present study aims to explore whether the disorder of intestinal flora and immune function can be reversed by changing the Vit D intake of eczema infants. In this study, 12 healthy infants were selected as the healthy control group (CON), and 32 infants with eczema were selected for the eczema patient groups, of which 8 were randomly allocated as the eczema model group (ECZ, for which the infants’ peripheral blood and stool were collected before any treatment). The 12 healthy infants and 32 eczema infants all regularly adhered to the feeding of Vit D 400 IU/d. The 32 eczema infants were randomly divided into 3 groups, and patients in each group took Vit D 200 (D-LOW), 400 (D-MED), and 800 (D-HIGH) IU/day for 1 month, respectively. The peripheral blood and stool of the three groups were collected one month later. Flow cytometry was used to detect the levels of T lymphocyte subsets (CD4+, CD8+, and CD4+/CD8+) and serum inflammatory factor interleukin IL-6, IL-10, and interferon-γ(IFN-γ). The contents of serum immunoglobulin Ig E and 25-(OH) D3 were detected by chemiluminescence. Two hypervariable regions of the bacterial 16S rRNA gene (V3–V4) were high-throughput sequenced for stool intestinal flora analysis. The results showed that no significant difference was found in the content of 25 (OH) D3 between the ECZ and the CON groups. However, the intestinal flora and immune function in the ECZ group were remarkably more disordered than those in the CON group (p < 0.05). After the corresponding medical treatments for one month, the LOW-D and HIGH-D groups presented some reversals in the intestinal flora and immune-related indexes in comparison to the ECZ group, and the reversal effect in the LOW-D group was most significant (p < 0.05). These results indicated that low-dose Vit D(200 IU/d) can partly improve the disorder of intestinal flora and immune function in eczema infants who usually adhere to a Vit D preventive dose of 400 IU/d feeding

Downregulation of lncRNA-HOXA11-AS modulates proliferation and stemness in Glioma cells

Abstract Background Glioma stem cells (GSCs) represent a subpopulation of cells within glioma that are characterized by chemotherapy resistance and tumor recurrence. GSCs are therefore important therapeutic target for glioma therapy. Long non-coding RNAs (lncRNAs) have been shown to regulate important functions in cancer. HOXA11-AS is one such lncRNA and has been shown to regulate cell proliferation via promotion of cell cycle progression in glioblastoma (GBM) cells. However, the specific roles of HOXA11-AS in GSCs remain unclear. Methods Here we investigated the role of HOXA11-AS in driving GSC stemness properties via sphere-forming and protein chip assays. Results Gain-of-function as well as loss-of-function results showed that the HOXA11-AS maybe a critical modulator in GBM recurrence as demonstrated by cell sphere-forming ability. Furthermore, we showed that induced expression of HOXA11-AS does increase the levels of stemness-related transcription factors (Oct4/Sox17/Sox2) in U87MG cells. In vivo xenograft experiments using the HOXA11-AS knockdown U87MG cells revealed that downregulation of HOXA11-AS could strongly inhibit tumor growth. Furthermore, we found that HOXA11-AS knockdown decreased the expression of cancer stemness markers in vivo. Conclusions Collectively, these data suggests that HOXA11-AS is involved in GSC stemness and supports its clinical significance as a important therapeutic target in glioma

Investigation of the Mechanical Physical Properties of Fly Ash Modified Magnesium Phosphate Cement Repair Mortar Cured at Varying Temperatures

To meet the material requirements for repairing cracked components serving in cold temperatures, the differences in the setting hardening characteristics and physical and mechanical properties of fly ash-modified magnesium phosphate cement (MPC) repair mortar cured at 0 °C and 20 °C were comparatively studied in this paper. The results show that under the same fly ash content, the compressive strength of MPC repair mortar cured at 0 °C is lower than that cured at 20 °C, and the setting time, fluidity, flexural strength, interfacial bonding strength, strength retention rate, and linear shrinkage rate are not significantly deteriorated. The above properties of MPC repair mortar vary with the increase in the fly ash content but still, remain appropriate when the fly ash content is not higher than 15 wt%. The microstructure of MPC is obviously refined when the content of fly ash is 10 wt%. Therefore, the MPC repair mortar cured at 0 °C and 20 °C has good physical and mechanical properties. In particular, the flexural strength and interfacial bonding strength of the specimens cured at 0 °C are higher than that cured at 20 °C at all curing ages, and at the curing age of 3 days, those are 7.9 MPa and 5.4 MPa, respectively

The value of the cinematic volume rendering technique: magnetic resonance imaging in diagnosing tumors associated with the brachial plexus

Abstract Purpose To examine the diagnostic advantages and clinical application value of the cinematic volume rendering technique (cVRT) when evaluating the relationship between the brachial plexus, peripheral tumor lesions, and blood vessels. Materials and methods Seventy-nine patients with brachial plexus tumors between November 2012 and July 2022 were enrolled in our study. All patients underwent T1WI, T2WI, three-dimensional short recovery time reversal recovery fast spin-echo imaging (3D-STIR-SPACE), and the T1WI enhancement sequence. In addition, cVRT was used to render and obtain a three-dimensional model that clearly showed the location and tissue structure of the brachial plexus nerves and the tumor in all directions. Results Seventy-one patients (mean age, 47.1 years; 33 males, 38 females) with tumors around the brachial plexus were included in the study. The brachial plexus nerve, surrounding tumor lesions, and vascular anatomy of all patients were well displayed with cVRT. The tumors of 37 patients manifested as unilateral or bilateral growths along the brachial plexus nerve and were fusiform, spherical, or multiple beaded; seven patients' tumors pushed against the brachial plexus nerve and were circular, lobular, or irregular; sixteen patients' tumors encircled the brachial plexus nerve and were spherical; and eleven patients' tumors infiltrated the brachial plexus nerve and had irregular morphology. The mass has a moderately uniform or uneven signal on T1WI and a high or mixed signal on T2WI. After enhancement, the signal was evenly or unevenly strengthened. Conclusions cVRT clearly showed the origin of tumors associated with the brachial plexus and their relationship with the nerves and peripheral blood vessels, providing reliable information for clinical diagnosis and treatment